WO2018190282A1

WO2018190282A1 - Light adjusting device

Info

Publication number: WO2018190282A1
Application number: PCT/JP2018/014824
Authority: WO
Inventors: 一茂中川; 彩子村松
Original assignee: 富士フイルム株式会社
Priority date: 2017-04-11
Filing date: 2018-04-06
Publication date: 2018-10-18

Abstract

Provided is a light adjusting device capable of adjusting light in a continuum. A first polarizer (20), a first pattern phase difference film (30a) and a second pattern phase difference film (30b) and a second polarizer (22) are stacked in this order, and the relative positions of the first pattern phase difference film (30a) and the second pattern phase difference film (30b) are moved in a uniaxial direction (t). The first pattern phase difference film (30a) and the second pattern phase difference film (30b) are formed with a stripe-shaped pattern in which two phase difference regions, of which at least one of a phase difference value and a slow axis direction differ from one another, are disposed alternately with the same width, where said width is at least equal to 1 μm and at most equal to 500 μm, wherein a long-side direction of the stripe-shaped pattern has an inclination relative to the uniaxial direction (t) in a range greater than 0° and less than 90°.

Description

Light control device

The present invention relates to a light control device that adjusts incident light using a polarizer and a pattern retardation film to obtain transmitted light, and more particularly, to a light control device that can continuously control the gradation.
To do.

Currently, various dimming methods using a polarizer have been proposed. About the light control method using a polarizer, utilizing for the light control of the sunlight which injects from the window for buildings is also anticipated.

Japanese Patent Application Laid-Open No. 9-310567 discloses that two planar materials are provided with a plurality of polarization regions in a pattern in which regions having different polarization axes are arranged adjacent to each other, and the two planar materials are relatively slid. Dimming is done. In other words, when the polarization region of the other planar material overlaps the polarization region of one planar material, the polarization regions with different polarization axes are superimposed from the state where the polarization regions having the same polarization axis are superimposed. And the translucency of the incident light is changed accordingly. Therefore, it is configured to perform dimming from the brightest state to the darkest state by sliding by the width of the polarization region.

However, as disclosed in Patent Document 1, the stripe of the conventional light control device has a width in the range of mm to cm and the width of the stripe is wide. End up.

In view of the above circumstances, an object of the present invention is to provide a light control device for realizing continuous gradation from the brightest state to the darkest state.

The light control device according to the present invention includes a first polarizer, a first pattern retardation film, a second pattern retardation film, and a second polarizer stacked in this order, and a pattern retardation of one. A light control device capable of adjusting the entire transmitted light amount by moving the relative position of a film and a second pattern retardation film along a uniaxial direction, wherein the first pattern retardation film and the second pattern retardation film The pattern phase difference film is formed in a stripe pattern in which two phase difference regions different in at least one of the phase difference value and the slow axis direction are alternately arranged with the same width, and the width is 1 μm or more to 500 μm or less. The long side direction of the striped pattern has an inclination in a range larger than 0 ° and smaller than 90 ° with respect to the uniaxial direction.

Further, the angle θ formed by the long-side direction and the uniaxial direction of the stripe pattern of the first pattern retardation film and the second pattern retardation film, and the width w of the stripe pattern are 0.5 mm ≦ w Those satisfying the relationship of / sin θ ≦ 100 mm are desirable.

In addition, at least one of the first pattern retardation film and the second pattern retardation film is a phase difference area having a phase difference value of zero and a phase difference area having a phase difference value other than zero. It may be a pattern retardation film having a formed stripe pattern.

Further, at least one of the first pattern retardation film and the second pattern retardation film is a retardation region in which an angle formed by the slow axes of adjacent retardation regions is 40 ° or more and 50 ° or less. It may be a patterned retardation film having a formed stripe pattern.

The light control device according to the present invention includes a first polarizer, a first pattern retardation film, a second pattern retardation film, and a second polarizer stacked in this order, and a stripe pattern is formed. The total amount of transmitted light is adjusted by relatively moving the formed first pattern retardation film and second pattern retardation film. At this time, continuous gradation can be achieved by setting the pattern width of the pattern retardation film to 1 μm or more to 500 μm or less. Further, in order to adjust the light as the pattern width becomes narrower, it is necessary to finely adjust the relative position of the two pattern retardation films. In the present invention, the stripe-shaped pattern is changed in the moving direction of the pattern retardation film. Therefore, the gradation can be finely adjusted by increasing the distance for adjustment for alignment.

(A) is a schematic block diagram which shows the light modulation apparatus of 1st Embodiment of this invention, (b) is the relationship between the polarizer and pattern retardation film which comprise the light modulation apparatus of 1st Embodiment of this invention. FIG. It is a top view of the 1st pattern phase contrast film and the 2nd pattern phase contrast film of the light modulation apparatus of a 1st embodiment. It is a figure for demonstrating the light control method of the light modulation apparatus of 1st Embodiment. It is a figure for demonstrating the mechanism of the light control of the light control apparatus of 1st Embodiment. It is a figure which shows the change of the relative position of the 1st pattern phase difference film and the 2nd pattern phase difference film when changing from a light shielding state to a transmissive state (from a transmissive state to a light shielding state). It is a top view of the 1st pattern phase contrast film and the 2nd pattern phase contrast film of the light modulation apparatus of a 2nd embodiment. It is a figure for demonstrating the light control method of the light modulation apparatus of 2nd Embodiment. It is a figure for demonstrating the light modulation mechanism of the light modulation apparatus of 2nd Embodiment. It is a top view of the 1st pattern phase contrast film and the 2nd pattern phase contrast film of the light modulation apparatus of a 3rd embodiment. It is a figure for demonstrating the light control method of the light modulation apparatus of 3rd Embodiment. It is a figure for demonstrating the mechanism of the light control of the light modulation apparatus of 3rd Embodiment. It is a figure which shows the formation process of the pattern phase difference film by a rubbing method.

Hereinafter, embodiments of the light control device of the present invention will be described with reference to the drawings.

In the following, “~” indicating a numerical range includes numerical values written on both sides. For example, the numerical value α to the numerical value β are ranges including the numerical value α and the numerical value β, and α ≦ ε ≦ β in mathematical symbols.

Angles such as 45 °, 90 °, 135 °, parallel, vertical and orthogonal mean that the difference from the exact angle is within a range of less than 5 ° unless otherwise specified. The difference from the exact angle is preferably less than 4 °, more preferably less than 3 °.

In addition, “same” includes an error range generally allowed in the technical field. In addition to “100%”, “all”, “any” or “entire surface” includes an error range generally allowed in the technical field, for example, 99% or more, 95% or more, or The case of 90% or more is included.

In this specification, Re (λ) and Rth (λ) represent in-plane retardation and retardation in the thickness direction at wavelength λ, respectively. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in an AxoScan manufactured by Axometrics.

In each drawing, the scale of the components is appropriately changed from the actual one for easy visual recognition.

<First Embodiment>
FIG. 1A shows a light control device according to the first embodiment of the present invention. The light control device 10 adjusts the transmittance of the incident light Li and adjusts the amount of the transmitted light Lo.

The light control device 10 includes a light control unit 12, a moving unit 14, and a control unit 16. The moving unit 14 is controlled by the control unit 16.

The light control unit 12 includes a first polarizer 20, a phase difference unit 24, and a second polarizer 22. The retardation part 24 includes two retardation films, a first pattern retardation film 30a and a second pattern retardation film 30b. The first polarizer 20, the first pattern retardation film 30a, the second pattern retardation film 30b, and the second polarizer 22 are stacked in this order.

As shown in FIG. 1 (b), the direction l ₂ of the transmission axis of the first direction l ₁ of the transmission axis of the polarizer 20 and second polarizer 22 are arranged to be orthogonal, a first polarizer Due to the change in the relative position of the first pattern retardation film 30a and the second pattern retardation film 30b provided between the first polarizer 20 and the second polarizer 22, the incident light incident from the first polarizer 20 is The amount of outgoing light that passes through and exits the second polarizer 22 is adjusted. The first polarizer 20, the first pattern retardation film 30a, the second pattern retardation film 30b, and the second polarizer 22 are all arranged in parallel, and the laminated surfaces are They are stacked in the same shape and size so that the length and width of the faces coincide.

The moving unit 14 includes a mechanism for relatively transferring the first pattern phase difference film 30a and the second pattern phase difference film 30b, and according to a signal from the control unit 16, the first pattern phase difference film 30a and the second pattern phase difference film 30a. It is possible to move any one of the two pattern retardation films 30b in the direction t of the movable axis. Or you may perform a relative movement by moving both the 1st pattern phase difference film 30a and the 2nd pattern phase difference film 30b to the direction t of a movable axis.

Hereinafter, the normal direction of the upper surface of the first polarizer 20 is referred to as a Z axis, and two axes parallel to the upper surface of the first polarizer 20 are referred to as an X axis and a Y axis.

The first pattern retardation film 30a and the second pattern retardation film 30b are configured by a pattern retardation film having a predetermined stripe pattern, and the first pattern retardation film 30a and the second pattern retardation film 30b. Dimming is performed according to the relative position of the phase difference film 30b. In order to realize a continuous gradation change from a transmission state (“bright state”) to a light-shielding state (“dark state”) with respect to incident light, the inventors reduce the stripe width. I found out that it would be possible. However, when the stripe width is narrowed, there is a problem that it is difficult to accurately align the stripe patterns of the two pattern retardation films.

Therefore, in the present invention, the stripe pattern is tilted with respect to the moving direction of the movable axis so that the moving direction of the movable axis extends across the stripe pattern, thereby changing from a bright state to a dark state. The amount of movement of the movable shaft until it was made larger.
Hereinafter, each member which comprises the light modulation apparatus 10 is demonstrated.

<First polarizer 20 and second polarizer 22>
The first polarizer 20 is an absorptive polarizer that transmits the first linearly polarized light and absorbs or reflects the second linearly polarized light orthogonal to the first linearly polarized light. The second polarizer 22 is an absorptive polarizer that transmits the second linearly polarized light and absorbs or reflects the first linearly polarized light.

As the polarizer, it is preferable to use a polymer film in which iodine is adsorbed and oriented. The polymer film is not particularly limited, and various types can be used. For example, polyvinyl alcohol films, polyethylene terephthalate films, ethylene / vinyl acetate copolymer films, partially saponified films of these, hydrophilic polymer films such as cellulose films, polyvinyl alcohol dehydrated products and polychlorinated Examples include polyene-based oriented films such as vinyl dehydrochlorinated products. Among these, it is preferable to use a polyvinyl alcohol film excellent in dyeability with iodine as a polarizer.

The wavelength range of the light transmitted or reflected by the first polarizer 20 and the second polarizer 22 is not particularly limited, and even within the wavelength range of infrared light or within the wavelength range of visible light, It may be within the wavelength range of ultraviolet light, and is a wavelength range that spans the wavelength range of infrared light and visible light, the wavelength range of visible light and ultraviolet light, or the wavelength range of infrared light, visible light, and ultraviolet light. May be. In particular, from the viewpoint that the heat shielding property and durability of the light control device are more excellent, it is preferably in the wavelength range of visible light or near infrared light.
In addition, infrared rays (infrared light) are electromagnetic waves in a wavelength region longer than visible rays and shorter than radio waves. Near-infrared light is generally an electromagnetic wave having a wavelength range of more than 750 nm and not more than 2500 nm. Visible light is light having a wavelength visible to the human eye among electromagnetic waves, and indicates light having a wavelength range of 380 nm to 750 nm. Ultraviolet rays are electromagnetic waves in a wavelength range shorter than visible light and longer than X-rays. The ultraviolet light may be light in a wavelength region that can be distinguished from visible light and X-rays, and is, for example, light in a wavelength range of 10 nm or more and less than 380 nm.

<First Pattern Retardation Film and Second Pattern Retardation Film>
FIG. 2 is a plan view of the first pattern retardation film 30a and the second pattern retardation film 30b of the light control device according to the first embodiment of the present invention.

The first pattern retardation film 30a includes a first retardation region 31 and a second retardation region 32 having different retardation values, and the first retardation region 31 and the second retardation region 32 are surfaces. They are alternately arranged in stripes. Similarly, the second pattern retardation film 30 b includes a third retardation region 33 and a fourth retardation region 34 having different retardation values, and the third retardation region 33 and the fourth retardation region 34. 34 are alternately arranged in stripes in the plane. Specifically, for example, the first phase difference region 31 and the second phase difference region 32 (or the third phase difference region 33 and the fourth phase difference region 34) having different phase difference values are combined. Are formed so as to be an isotropic phase difference region having a phase difference value of zero passing through the pattern

phase difference films

30a and 30b and an anisotropic phase difference region having a phase difference value other than zero. Is done. The first phase difference region 31 and the second phase difference region 32, and the third phase difference region 33 and the fourth phase difference region 34 are each composed of a region in which liquid crystal is aligned, and the ellipse in FIG. Indicates the respective orientations as a model.

In the plan view of FIG. 2, the first retardation region 31 is shown in gray to distinguish the first retardation region 31 and the second retardation region 32 of the first pattern retardation film 30a. As shown in FIG. 2, a stripe pattern in which the first retardation region 31 and the second retardation region 32 are alternately arranged is formed, and the stripe width w ₁ of the _first retardation region 31 and the first retardation region 31 are changed. The stripe widths w ₂ of the _two retardation regions 32 are the same. The stripe widths w ₁ and w ₂ of the first retardation region 31 and the second retardation region 32 are, for example, 1 μm to 500 μm, and are alternately arranged in the width direction with a period of 2 μm to 1 mm. Further, the long side direction of the striped pattern is arranged in a state having an inclination θ with respect to the direction t of the movable axis. Preferably, the stripe widths w ₁ and w ₂ are 5 μm to 350 μm, and are alternately arranged in the width direction with a period of 10 μm to 700 μm. More preferably, the stripe widths w ₁ and w ₂ are 30 μm to 250 μm, and are alternately arranged in the width direction at a period of 60 μm to 500 μm.

Similarly, the third retardation region 33 is shown in gray to distinguish the third retardation region 33 and the fourth retardation region 34 of the second pattern retardation film 30b. Third stripe width w ₄ of the stripe width w ₃ of the retardation region 33 fourth retardation region 34 is the same, the third retardation region 33 stripe width w ₃ of the fourth retardation region 34 , w ₄ are arranged alternately in a first pattern retardation film 30a and the width and period of the same as the first retardation region 31 and the second retardation region 32. The stripe pattern of the second pattern retardation film 30b is arranged with the same inclination as the stripe pattern of the first pattern retardation film 30a.

The angle θ formed by the long-side direction of the stripe pattern of the first pattern phase difference film 30a and the second pattern phase difference film 30b and the direction t of the movable axis is within a range larger than 0 ° and smaller than 90 °. Although it is good, it is determined according to the stripe width w. Specifically, the angle θ and the stripe width w (= w ₁ = w ₂ = w ₃ = w ₄ ) are
0.5mm ≦ w / sinθ ≦ 100mm
It is desirable to arrange so as to satisfy the relationship. The reason for arranging so as to satisfy this relationship will be described later.

The first retardation region 31 and the third retardation region 33 are optical anisotropy regions that give a phase difference of λ / 2 before the light incident on the

pattern retardation film

30a or 30b is emitted. In the example of FIG. 2, the first retardation region 31 is a λ / 2 retardation region in which the angle formed by the transmission axis of the first polarizer 20 and the slow axis of the first retardation region 31 is 45 °. The third retardation region 33 is a λ / 2 retardation region in which the angle formed by the transmission axis of the first polarizer 20 and the slow axis of the third retardation region 33 is 135 °. Therefore, when the incident light is linearly polarized light, the emitted light has a polarization axis that makes an inclination of 90 ° with respect to the polarization axis at the time of incidence.

The first retardation region 31 and the third retardation region 33 are not limited in their constituent materials, but can be formed using, for example, a liquid crystal material (polymerizable liquid crystal composition). Specifically, it can be composed of a region where a rod-like liquid crystal compound or a disk-like liquid crystal compound is fixed.

Since the second retardation region 32 and the fourth retardation region 34 are optically isotropic regions, they are emitted without affecting the polarization state of the light passing therethrough. The constituent material of the first retardation region 31 and the third retardation region 33 is not limited as long as the second retardation region 32 and the fourth retardation region 34 are optically isotropic. It is preferable that it is comprised with the same liquid crystal material.

The first retardation region in the pattern retardation film has a function of giving a λ / 2 retardation, and whether or not the second retardation region is isotropic is determined by, for example, AxoStep high accuracy. It can be confirmed by a known method such as measurement using a Mueller matrix imaging polarimeter or the like.
(Moving part and control part)

The moving unit 14 moves the relative positions of the two pattern phase difference films (the first pattern phase difference film 30a and the second pattern phase difference film 30b) of the phase difference unit 24 according to the control of the control unit 16 with respect to the movable axis. A mechanism for moving in the direction t is provided, and any one of the two pattern phase difference films (the first pattern phase difference film 30a and the second pattern phase difference film 30b) is moved. Alternatively, a configuration in which the two sheets are relatively moved may be employed.

By changing the relative position of the two pattern retardation films (first pattern retardation film 30a and second pattern retardation film 30b) by the moving unit 14, the first polarizer 20 or the second polarization It is possible to change the transmittance of incident light incident from the child 22. Hereinafter, a case where the moving unit 14 moves the second pattern retardation film 30b in the direction of the movable axis will be described.

<Light control mechanism>
Next, a mechanism for dimming in steps from the transmission state to the light shielding state using the light control device 10 will be described. The direction l ₁ of the transmission axis of the first polarizer 20 is a 135 ° direction inclined relative to the X axis, the direction l ₂ of the transmission axis of the second polarizer 22, the X-axis A case where the direction is inclined by 45 ° will be described.

3 (a) and 3 (b) are diagrams for explaining a light control method of the light control device according to the embodiment of the present invention. 3 (a) and 3 (b), the same components as those of the light control device 10 shown in FIGS. 1 (a) and 1 (b) are denoted by the same reference numerals.

3 (a) and 3 (b) are schematic views before and after the second pattern retardation film 30b is slid. As shown in FIG. 3A, when viewed from the XZ plane, the first retardation region 31 and the third retardation region 33 overlap (or the second retardation region 32 and the fourth retardation region 33). In the case where the phase difference region 34 overlaps, the light Li incident on the first polarizer 20 from the direction of the arrow in FIG. That is, the state of FIG. 3A is a light shielding state (“dark state”).

On the other hand, FIG. 3B is a diagram in which the second pattern retardation film 30b is slid (moved) by the relative movement amount D from FIG. 3A. In this case, when viewed from the XZ plane, the first retardation region 31 and the fourth retardation region 34 overlap (or the second retardation region 32 and the third retardation region 33 overlap), The light Li incident on the first polarizer 20 from the direction of the arrow in FIG. 3B passes through the light control device 10 and is emitted as light Lo. That is, the state of FIG. 3B is a transmission state (“bright state”).

Hereinafter, the mechanism in which light is transmitted or blocked by the light control device 10 will be described in more detail with reference to FIGS. 4A and 4B in conjunction with FIGS. Note that the polarization axis of linearly polarized light having a polarization axis inclination α with respect to the + X axis in the XY plane when the incident light is linearly polarized light is represented as P _α . That is, a polarization axis with an inclination of 0 ° is represented as P ₀ , a polarization axis with an inclination of 90 ° is represented as P ₉₀ , a polarization axis with an inclination of 45 ° is represented as P ₄₅ , and a polarization axis with an inclination of 135 ° is represented as P ₁₃₅ . Similarly, a slow axis having a slow axis inclination α with respect to the + X axis in the XY plane will be described below as P _α .

As shown in FIGS. 4A and 4B, the transmission axis direction l _{1 of} the first polarizer 20 is P ₁₃₅ , and the transmission axis direction l _{2 of} the second polarizer 22 is P ₄₅ . The case will be described. At this time, the direction of the slow axis in the first phase difference region is P ₉₀ , and the direction of the slow axis in the third phase difference region is P ₀ . The second and fourth phase difference regions are isotropic regions and are expressed as “iso”.

The state shown in FIG. 3A will be described with reference to FIG.
In the region R1 in FIG. 3 (a), first of the incident light to the polarizer 20, the linearly polarized light L1 that only the transmission axis parallel to the linear polarization of the first polarizer 20 has a polarization axis P ₁₃₅ Is emitted. Then, the linearly polarized light L1 is polarization axis is emitted as linearly polarized light L2 having a 90 ° inclined polarization axis P ₄₅ by the first retardation region 31. Furthermore, linearly polarized light L2, the polarization axis is emitted as linearly polarized light L3 having a polarization axis P ₁₃₅ which is inclined 90 ° by the third retardation region 33. Since the polarization axis P ₁₃₅ of the linearly polarized light L 3 and the transmission axis direction P ₄₅ of the second polarizer 22 are orthogonal, the linearly polarized light L 3 is absorbed by the second polarizer 22.

On the other hand, in the region R2, the linearly polarized light L4 having a polarization axis P ₁₃₅ that has passed through the first polarizer 20 linearly with polarization axis P ₁₃₅ passes through the second retardation region 32 while maintaining the polarization axis is emitted as polarization L5, is emitted as linearly polarized light L6 having a polarization axis P ₁₃₅ then passes through the fourth retardation region 34. Since the polarization axis P ₁₃₅ to the direction P ₄₅ of the transmission axis of the second polarizer 22 of the linearly polarized light L6 are orthogonal, linearly polarized light L6 is absorbed by the second polarizer 22.

That is, when the first phase difference region 31 and the third phase difference region 33 overlap (or when the second phase difference region 32 and the fourth phase difference region 34 overlap), the first polarizer. The light incident on 20 is not emitted from the second polarizer 22 and cannot pass through the light control device 10.

Next, as shown in FIG. 3B, a state where the second pattern retardation film 30b is slid by the relative movement amount D from FIG. 3A will be described with reference to FIG. 4B.

In the region R1 in FIG. 3 (b), the first of the incident light to the polarizer 20, the linearly polarized light only transmission axis parallel to the linear polarization of the first polarizer 20 has a polarization axis P ₁₃₅ L11 Is emitted. Then, the linearly polarized light L11 is polarization axis is emitted as linearly polarized light L12 having a 90 ° inclined polarization axis P ₄₅ by the first retardation region 31. Furthermore, linearly polarized light L12 reaches the polarization axis linearly polarized light L13 next passes through the fourth retardation region 34 while keeping P _45, the second polarizer 22. Since the direction P ₄₅ of the transmission axis of the polarizing axis P ₄₅ of the linearly polarized light L13 the second polarizer 22 coincides linearly polarized light L13 is directly transmitted through the second polarizer 22.

On the other hand, in the region R2, the linearly polarized light L14 having a polarization axis P ₁₃₅ that has passed through the first polarizer 20 becomes linearly polarized light L15 is transmitted through the second retardation region 32 while maintaining the polarization axis P ₁₃₅ . Then, the linearly polarized light L15 is polarization axis is emitted as linearly polarized light L16 having a 90 ° inclined polarization axis P ₄₅ by the third retardation region 33. Since the direction P ₄₅ of the polarizing axis P ₄₅ of the linearly polarized light L16 transmission axis of the second polarizer 22 coincides linearly polarized light L16 is directly transmitted through the second polarizer 22.

That is, when the first retardation region 31 and the fourth retardation region 34 overlap (or when the second retardation region 32 and the third retardation region 33 overlap), the first polarizer 20. Is emitted from the second polarizer 22 and passes through the light control device 10.

In the above description, the transmission axis direction l _{1 of} the first polarizer 20 is the direction P ₁₃₅ tilted by 135 ° with respect to the X axis, and the transmission axis direction l _{2 of} the second polarizer 22 is the X axis. If a 45 ° direction P ₄₅ inclined has been described with respect to, the first retardation region 31 and the third retardation region 33 is not limited to this n × λ / 2 (n is an odd number Of the first polarizer 20 when the second phase difference region 32 and the fourth phase difference region 34 are isotropic regions (iso). direction of the transmission axis l ₁ and the transmission axis direction l ₂ is orthogonal to the second polarizer 22, and the angle of the slow axis of the transmission axis of the first retardation region 31 of the first polarizer 20 Is 45 °, and the first polarization is so formed that the angle between the transmission axis of the first polarizer 20 and the slow axis of the third retardation region 33 is 135 °. The optical element 20, the first pattern retardation film 30a, the second pattern retardation film 30b, and the second polarizer 22 may be disposed.

Next, the relationship between the relative movement amount of the two pattern retardation films and the multi-tone light control will be described. As described above, when the first phase difference region 31 and the third phase difference region 33 overlap (or when the second phase difference region 32 and the fourth phase difference region 34 overlap), the light shielding state occurs. When the first phase difference region 31 and the fourth phase difference region 34 overlap (or when the second phase difference region 32 and the third phase difference region 33 overlap), the transmission state is set. As shown in (1) to (5) of FIG. 5, the second pattern retardation film is moved in the direction t of the movable axis from the state where it overlaps the first retardation region 31 and the third retardation region 33. By gradually moving, the overlap between the first phase difference region 31 and the third phase difference region 33 decreases, and the overlap between the first phase difference region 31 and the fourth phase difference region 34 increases. As this overlap increases, the light is gradually brightened from the light-shielded state and reaches the transmissive state. As shown in FIG. 2, the smaller the angle θ formed between the direction t of the movable axis and the long side direction of the stripe, the more the first retardation region 31 and the third retardation region 33 overlap, The relative movement amount D (= w / sin θ) until the phase difference region 31 and the fourth phase difference region 34 are changed to the overlapped state is increased, and multi-tone adjustment is facilitated, and continuous tone change is performed. Can be realized.

For example, when the stripe width w is 200 μm and the long side direction of the stripe is perpendicular (θ = 90 °) to the direction t of the movable axis (θ = 90 °), the relative movement amount D from the light shielding state to the transmission state D For example, when θ is 3 °, the relative movement amount D from the light shielding state to the transmission state is
D = 200 μm / sin 3 ° ≈3821 μm
It becomes. The relative movement amount D is preferably as large as possible. However, as θ decreases, it becomes difficult to accurately set the stripe inclination with respect to the movable axis direction t. Considering these, it is desirable to determine the inclination of the stripe so as to satisfy 0.5 mm ≦ w / sin θ (= D) ≦ 100 mm as in the above formula (1).

Note that moire tends to occur when the first pattern retardation film 30a and the second pattern retardation film 30b are separated from each other, and therefore the first pattern retardation film 30a and the second pattern retardation film 30b are It is desirable to arrange them in contact with each other.

<Second Embodiment>
Next, a second embodiment will be described. The schematic configuration of the light control device of this embodiment is the same as that of the first embodiment. The moving unit 14 and the control unit 16 are the same as those in the first embodiment. In the second embodiment, the first pattern phase difference film 30a and the second pattern phase difference film 30b have a stripe shape in which two regions having the same phase difference value but different slow axis directions are alternately arranged. It is composed of patterns. The first polarizer 20 and the second polarizer 22 are the same members as in the first embodiment.

<First Pattern Retardation Film and Second Pattern Retardation Film>
FIG. 6 is a plan view of the first pattern retardation film 30a and the second pattern retardation film 30b of the light control device according to the second embodiment of the present invention.

The first pattern retardation film 30a includes a first retardation region 31 and a second retardation region 32 having different slow axis directions, and the first retardation region 31 and the second retardation region 32 are The stripes are alternately arranged in the plane. In the present embodiment, since the second pattern retardation film 30b is the same as the first pattern retardation film 30a, detailed description thereof is omitted. The third phase difference region 33 of the second pattern phase difference film 30b is arranged in the same manner as the first phase difference region 31 of the first pattern phase difference film 30a and has the same function. The fourth retardation region 34 of the retardation film 30b is arranged in the same manner as the second retardation region 32 of the first pattern retardation film 30a and has the same function. The first retardation region 31 and the second retardation region 32 are each composed of a region in which liquid crystals are aligned, and the ellipses in FIG. 6 indicate the respective alignments as a model.

The numerical values and preferable numerical ranges of the stripe widths w ₁ to w _{4 in} FIG. 6 are the same as those in the first embodiment, and the preferable constituent materials for forming the respective retardation regions are also the same as those in the first embodiment. .

Both the first retardation region 31 and the second retardation region 32 are optical anisotropy regions that give a retardation of the slow axis to λ / 4 before the light incident on the pattern retardation film 30 is emitted. is there. In the example of FIG. 6, the first retardation region 31 is a λ / 4 retardation region in which the angle formed by the transmission axis of the first polarizer 20 and the slow axis of the first retardation region 31 is 45 °. In addition, the second retardation region 32 is a λ / 4 retardation region in which the angle formed by the transmission axis of the first polarizer 20 and the slow axis of the second retardation region 32 is 135 °. Therefore, if the incident light is linearly polarized light, the emitted light is changed to circularly polarized light. If the incident light is circularly polarized light, the emitted light is changed to linearly polarized light.

Next, a mechanism for dimming in steps from the transmission state to the light shielding state using the light control device 10 will be described. Like the first embodiment, the direction l ₁ of the transmission axis of the first polarizer 20 is the direction P ₁₃₅ inclined 135 ° with respect to the X axis, the direction of the transmission axis of the second polarizer 22 A case where l ₂ is a direction P ₄₅ inclined by 45 ° with respect to the X axis will be described.

7 (a) and 7 (b) are schematic views before and after the second pattern retardation film 30b is slid. As shown in FIG. 7A, when viewed from the XZ plane, the first phase difference region 31 and the third phase difference region 33 overlap (or the second phase difference region 32 and the fourth position). When the phase difference region 34 overlaps), the light Li incident on the first polarizer 20 from the direction of the arrow in FIG. 7A passes through the light control device 10 and is emitted as light Lo. That is, the state of FIG. 7A is a transmission state (“bright state”).

On the other hand, FIG. 7B is a diagram in which the second pattern retardation film 30b is slid by the relative movement amount D from FIG. 7A. In this case, when viewed from the XZ plane, the first retardation region 31 and the fourth retardation region 34 overlap (or the second retardation region 32 and the third retardation region 33 overlap), The light Li that enters the first polarizer 20 from the direction of the arrow in FIG. 7B does not pass through the light control device 10. That is, the state of FIG. 7B is a light shielding state (“dark state”).

FIGS. 8A and 8B show a mechanism in which light is transmitted or blocked by the light control device 10 of the second embodiment. As indicated by R1 in FIG. 8A, the λ / 4 regions (the first phase difference region 31 and the third phase difference region 33, the second phase difference region 32 and the fourth phase difference region are the same in the slow axis direction. When the phase difference region 34) is overlapped (see FIG. 7A), the incident light Li passes through the polarizer 20 and then becomes linearly polarized light L 21 having the polarization axis P ₁₃₅ and passes through the first phase difference region 31. As a result, clockwise circularly polarized light L22 is obtained. The circularly polarized light L <b> 22 passes through the third phase difference region 33, thereby becoming linearly polarized light L <b> 23 having a polarization axis P <b> ₄₅ and transmitted through the polarizer 22. The same applies to R2 in FIG. 8A and R1 and R2 in FIG. 8B. However, in FIG. 8B, since the combination of the phase difference regions is different, incident light is absorbed.

In the above description, the transmission axis direction l _{1 of} the first polarizer 20 is the direction P ₁₃₅ tilted by 135 ° with respect to the X axis, and the transmission axis direction l _{2 of} the second polarizer 22 is the X axis. If a 45 ° direction P ₄₅ inclined has been described with respect to, not limited to this, the first retardation region 31 and the second retardation region 32 is n × λ / 4 (n is when configured in retardation region of the odd natural number), the transmission axis direction l ₂ is orthogonal to the first direction l ₁ of the transmission axis of the polarizer 20 and second polarizer 22, and first The angle formed by the transmission axis of the first polarizer 20 and the slow axis of the first retardation region 31 (or the third retardation region 33) is 45 °, and the transmission axis of the first polarizer 20 The first polarizer 20 and the first filter are set so that the angle formed by the slow axes of the two retardation regions 32 (or the fourth retardation region 34) is 135 °. The turn retardation film 30a, the second pattern retardation film 30b, and the second polarizer 22 may be disposed.

Next, the relationship between the relative movement amount of the two pattern retardation films and the multi-tone light control will be described. As in the first embodiment, as shown in (1) to (5) of FIG. 5, the second pattern position is changed from the state where the first phase difference region 31 and the third phase difference region 33 overlap. By gradually moving the phase difference film in the direction t of the movable axis, the overlap between the first phase difference region 31 and the third phase difference region 33 is reduced, and the first phase difference region 31 and the fourth phase difference are reduced. The overlap of the region 34 increases. In this embodiment, as the overlap increases, the transmission state gradually becomes darker and reaches a shielding state.

<Third Embodiment>
Next, a third embodiment will be described. The schematic configuration of the light control device according to the present embodiment is that the first pattern retardation film 30a and the second pattern retardation film 30b alternate between two regions having a retardation value of λ / 2 and different slow axis directions. The second embodiment is the same as the first embodiment except that it is configured by a stripe pattern arranged in the first embodiment.

<First Pattern Retardation Film and Second Pattern Retardation Film>
In FIG. 9, the first retardation region 31 and the second retardation region 32, and the third retardation region 33 and the fourth retardation region 34 are each composed of a region in which liquid crystal is aligned, The ellipse in FIG. 9 represents the slow axis by showing the respective orientations as a model.

The numerical values of stripe widths w ₁ to w ₄ and the preferable numerical range in FIG. 9 are the same as those of the first embodiment, and the preferable constituent materials for forming the respective retardation regions are also the same as those of the first embodiment. is there.

The first phase difference region 31, the second phase difference region 32, the third phase difference region 33, and the fourth phase difference region 34 all have a slow axis phase difference before the incident light is emitted. Is an optically anisotropic region giving λ / 2. In the example of FIG. 9, the first retardation region 31 is a λ / 2 retardation region in which the angle formed by the transmission axis of the first polarizer 20 and the slow axis of the first retardation region 31 is 45 °. The second retardation region 32 is a λ / 2 retardation region in which the angle formed by the transmission axis of the first polarizer 20 and the slow axis of the second retardation region 32 is 0 °. The phase difference region 33 is a λ / 2 phase difference region where the angle between the transmission axis of the first polarizer 20 and the slow axis of the third phase difference region 33 is 135 °, and the fourth phase difference region. Reference numeral 34 denotes a λ / 2 phase difference region where the angle formed by the transmission axis of the first polarizer 20 and the slow axis of the fourth phase difference region 34 is 90 °. If the incident light is linearly polarized light, and the direction of the polarization axis of the incident light coincides with the direction of the slow axis of each region, the outgoing light remains the polarization axis of the incident light, and the polarization axis of the incident light. When the direction of the slow axis does not coincide with that of the slow axis, the emitted light has a polarization axis that is inclined by 90 ° with respect to the polarization axis at the time of incidence.

A mechanism for dimming in steps from the transmission state to the light shielding state using the light control device 10 will be described. Similar to the first and second embodiments, the direction l ₁ of the transmission axis of the first polarizer 20 is the direction P ₁₃₅ inclined 135 ° with respect to the X axis, transmission of the second polarizer 22 The case where the axial direction l ₂ is a direction P ₄₅ inclined by 45 ° with respect to the X axis will be described.

FIGS. 10A and 10B are schematic views before and after sliding the second pattern retardation film 30b. As shown in FIG. 10A, when viewed from the XZ plane, the first phase difference region 31 and the third phase difference region 33 overlap (or the second phase difference region 32 and the fourth position). When the phase difference region 34 overlaps), the light Li incident on the first polarizer 20 from the direction of the arrow in FIG. 10A does not pass through the light control device 10. That is, the state of FIG. 10A is a light shielding state (“dark state”).

On the other hand, FIG. 10B is a diagram in which the second pattern retardation film 30b is slid by the relative movement amount D from FIG. 10A. In this case, when viewed from the XZ plane, the first retardation region 31 and the fourth retardation region 34 overlap (or the second retardation region 32 and the third retardation region 33 overlap), The light Li incident on the first polarizer 20 from the direction of the arrow in FIG. 10B passes through the light control device 10 and is emitted as light Lo. That is, the state of FIG. 10B is a transmission state (“bright state”).

Hereinafter, a mechanism in which light is transmitted or blocked by the light control device 10 of the third embodiment is shown in FIGS. As indicated by R1 in FIG. 11A, the λ / 2 regions (the first phase difference region 31 and the third phase difference region 33, the second phase difference region 32, and the If repeated 4 retardation region 34) reference (FIG. 10 (a)), next to the linearly polarized light L41 incident light Li having a polarization axis P ₁₃₅ after passing through the polarizer 20, the first retardation region 31 by passing, the linearly polarized light L42 having a polarization axis P _45. Linearly polarized light L42 is than passing through the third retardation region 33, becomes linearly polarized light L43 having a polarization axis P _135, is absorbed by the polarizer 22. The same applies to R2 in FIG. 11 (a) and R1 and R2 in FIG. 11 (b). However, in FIG. 11B, since the combination of the phase difference regions is different, the incident light is transmitted.

In the above description, the transmission axis direction l _{1 of} the first polarizer 20 is the direction P ₁₃₅ tilted by 135 ° with respect to the X axis, and the transmission axis direction l _{2 of} the second polarizer 22 is the X axis. If a 45 ° direction P ₄₅ inclined has been described with respect to, not limited to this, the first to fourth retardation region 33 is n × λ / 2 of the (n is a natural number of odd) when configured in retardation region, the direction l ₁ of the transmission axis of the first polarizer 20 transmission axis l ₂ is orthogonal to the second polarizer 22, and the first polarizer 20 The angle formed by the transmission axis of the first polarizer 20 and the slow axis of the first retardation region 31 is 45 °, and the angle formed by the transmission axis of the first polarizer 20 and the slow axis of the second retardation region 32 is 0 °. Thus, the angle formed by the transmission axis of the first polarizer 20 and the slow axis of the third retardation region 33 is 135 °, and the transmission axis of the first polarizer 20 and the fourth phase difference. The first polarizer 20, the first pattern retardation film 30a, the second pattern retardation film 30b, and the second polarizer 22 are arranged so that the angle formed by the slow axis of the region 34 is 90 °. Just do it.

Next, the relationship between the relative movement amount of the two pattern retardation films and the multi-tone light control will be described. As in the first embodiment, as shown in (1) to (5) of FIG. 5, the second pattern position is changed from the state where the first phase difference region 31 and the third phase difference region 33 overlap. By gradually moving the phase difference film in the direction t of the movable axis, the overlap between the first phase difference region 31 and the third phase difference region 33 is reduced, and the first phase difference region 31 and the fourth phase difference are reduced. The overlap of the region 34 increases. In the present embodiment, as the overlap increases, the light shielding state gradually becomes brighter and reaches the transmission state.

Next, materials and manufacturing of the first retardation region 31 and the second retardation region 32 of the pattern retardation film 30a and the third retardation region 33 and the fourth retardation region 34 of the pattern retardation film 30b. A method will be described.

The patterned

pattern retardation films

30a and 30b are patterned in a predetermined direction by forming a patterned alignment film on a support, and then uniformly applying the polymerizable liquid crystal composition and then fixing it. Or after forming an alignment film on a support, a polymerizable liquid crystal composition is uniformly applied, mask exposure is performed using a pattern mask, and regions for anisotropic regions are exposed to ultraviolet rays. To fix the liquid crystal compound in a predetermined alignment direction, and then heat-expose the entire surface in the absence of a pattern mask to make the non-fixed region an isotropic region. It is produced by a method of forming a pattern of regions and anisotropic regions.

The alignment film can be produced using a known method such as a photo-alignment method or a rubbing method. As an example of a method for providing an alignment film by the photo-alignment method, an alignment film composition is applied as an example, and is aligned by irradiating ultraviolet rays while being arranged in the direction of the transmission axis of the wire grid polarizer in the direction of the slow axis. A film is formed. As an example of a method of providing an alignment film by rubbing, an alignment film is formed by applying a PVA aqueous solution and rubbing the surface of the coating film several times in a predetermined direction using a cloth or the like.

Next, a liquid crystal composition containing a polymerizable liquid crystal compound used for forming the

pattern retardation films

30a and 30b will be described. In addition to the polymerizable liquid crystal compound, a polymerization initiator, a crosslinking agent, an alignment control agent, and the like can be further added to the liquid crystal composition as necessary.
(Polymerizable liquid crystal compound)
The polymerizable liquid crystal compound may be a rod-like liquid crystal compound or a disk-like liquid crystal compound, but a rod-like liquid crystal compound is preferred.
As an example of the rod-like polymerizable liquid crystal compound, not only a low-molecular liquid crystal compound but also a polymer liquid crystal compound can be used.

The polymerizable liquid crystal compound can be obtained by introducing a polymerizable group into the liquid crystal compound. Examples of the polymerizable group include an unsaturated polymerizable group, an epoxy group, an oxetanyl group, and an aziridinyl group, preferably an unsaturated polymerizable group, and particularly preferably an ethylenically unsaturated polymerizable group. The polymerizable group can be introduced into the molecule of the liquid crystal compound by various methods. The number of polymerizable groups possessed by the polymerizable liquid crystal compound is preferably 1 to 6, more preferably 1 to 3. Examples of polymerizable liquid crystal compounds are described in Makromol. Chem. 190, 2255 (1989), Advanced Materials 5, 107 (1993), US Pat. No. 4,683,327, US Pat. No. 5,622,648, US Pat. No. 5,770,107, International Publication WO 95/22586, WO 95 / 24455, WO 97/00600, WO 98/23580, WO 98/52905, JP-A-1-272551, JP-A-6-16616, JP-A-7-110469, JP-A-11-80081, and JP-A-2001. The compounds described in JP-A No. -328973, JP-A 2009-69793, JP-A 2010-113249, JP-A 2011-203636, and the like are included. Two or more kinds of polymerizable liquid crystal compounds may be used in combination. When two or more kinds of polymerizable liquid crystal compounds are used in combination, the alignment temperature can be lowered.

As the polymerizable liquid crystal compound, it is also preferable to use a liquid crystal compound having two or more reactive groups having different polymerization conditions in the same molecule. Examples of combinations of reactive groups with different polymerization conditions include combinations of radical photopolymerizable reactive groups and cationic photopolymerizable reactive groups. In particular, a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound described in JP-A-2008-127336 can be suitably used.

(Polymerization initiator)
The liquid crystal composition preferably contains a polymerization initiator. In the embodiment in which the polymerization reaction is advanced by ultraviolet irradiation, the polymerization initiator to be used is preferably a photopolymerization initiator that can start the polymerization reaction by ultraviolet irradiation. Examples of the photopolymerization initiator include a radical polymerization initiator and a cationic polymerization initiator.

As the radical polymerization initiator, an acyl phosphine oxide compound or an oxime compound is preferably used.
As the acylphosphine oxide compound, for example, IRGACURE819 (compound name: bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide) manufactured by BASF Japan Ltd. can be used. Examples of the oxime compounds include IRGACURE OXE01 (manufactured by BASF), IRGACURE OXE02 (manufactured by BASF), TR-PBG-304 (manufactured by Changzhou Strong Electronic New Materials Co., Ltd.), Adeka Arcles NCI-831, Adeka Arcles NCI-930 Commercial products such as (ADEKA) and Adeka Arcles NCI-831 (ADEKA) can be used.

Examples of the cationic polymerization initiator include organic sulfonium salt systems, iodonium salt systems, phosphonium salt systems, and the like. Organic sulfonium salt systems are preferable, and triphenylsulfonium salts are particularly preferable. As counter ions of these compounds, hexafluoroantimonate, hexafluorophosphate, and the like are preferably used.

Only one type of polymerization initiator may be used, or two or more types may be used in combination.
The content of the polymerization initiator in the liquid crystal composition is preferably 0.1 to 20% by mass with respect to the content of the polymerizable liquid crystal compound.

(Crosslinking agent)
The liquid crystal composition may optionally contain a crosslinking agent in order to improve the film strength after curing and improve the durability. As the cross-linking agent, one that can be cured by ultraviolet rays, heat, moisture, or the like can be suitably used.
The crosslinking agent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polyfunctionality such as trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, etc. Acrylate compounds; Epoxy compounds such as glycidyl (meth) acrylate and ethylene glycol diglycidyl ether; 2,2-bishydroxymethylbutanol-tris [3- (1-aziridinyl) propionate], 4,4-bis (ethyleneiminocarbonylamino) ) Aziridine compounds such as diphenylmethane; isocyanate compounds such as hexamethylene diisocyanate and biuret type isocyanate; polyoxazoline compounds having an oxazoline group in the side chain; vinyltrimethoxysila And N-(2-aminoethyl) 3-aminopropyltrimethoxysilane alkoxysilane compounds may be mentioned. Of these, polyfunctional acrylate compounds are preferred. The polyfunctional acrylate compound is preferably a 3-6 functional acrylate compound, and more preferably a 4-6 functional acrylate compound. Moreover, a well-known catalyst can be used according to the reactivity of a crosslinking agent, and productivity can be improved in addition to membrane strength and durability improvement. These may be used individually by 1 type and may use 2 or more types together.

The content of the cross-linking agent in the liquid crystal composition is preferably 0 to 8.0 parts by mass, and 0.1 to 7.0 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound in the liquid crystal composition. Is more preferable, and 0.2 to 5.5 parts by mass is even more preferable.

(Orientation control agent)
An alignment control agent that contributes to stable or rapid planar alignment may be added to the liquid crystal composition. Examples of the alignment control agent include fluorine (meth) acrylate polymers described in paragraphs [0018] to [0043] of JP-A-2007-272185, and paragraphs [0031] to [0034] of JP-A-2012-203237. And compounds represented by the formulas (I) to (IV) as described above.
In addition, as an orientation control agent, 1 type may be used independently and 2 or more types may be used together.

The addition amount of the alignment control agent in the liquid crystal composition is preferably 0.01% by mass to 10% by mass and more preferably 0.01% by mass to 5.0% by mass with respect to the total mass of the polymerizable liquid crystal compound. .

(Other additives)
In addition, the liquid crystal composition may contain at least one selected from a surfactant for adjusting the surface tension of the coating film to make the thickness uniform, and various additives such as a polymerizable monomer. Further, in the liquid crystal composition, if necessary, a polymerization inhibitor, an antioxidant, an ultraviolet absorber, a light stabilizer, a colorant, metal oxide fine particles, and the like may be added as long as the optical performance is not deteriorated. Can be added.

(solvent)
There is no restriction | limiting in particular as a solvent used for preparation of a liquid-crystal composition, Although it can select suitably according to the objective, An organic solvent is used preferably.
The organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include ketones, alkyl halides, amides, sulfoxides, heterocyclic compounds, hydrocarbons, esters, ethers and the like. Can be mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, ketones are particularly preferable in consideration of environmental load.

<Formation of pattern retardation film with isotropic region and anisotropic region>
First, the manufacturing process of the

pattern retardation films

30a and 30b in which the isotropic region and the anisotropic region are patterned will be described.
In this production process, after forming an alignment film on the support, a polymerizable liquid crystal composition is uniformly applied, mask exposure is performed using a pattern mask, and the region with respect to the anisotropic region is irradiated with ultraviolet rays. Then, the liquid crystal compound is fixed in a predetermined alignment direction, and then the entire surface is heated and exposed without a pattern mask, thereby making the non-fixed region an isotropic region.

Pattern retardation films

30a and 30b having anisotropic regions are formed. Each step will be described in detail with reference to the manufacturing steps shown in FIG.

<< Orientation process >>
A known method such as a photo-alignment method or a rubbing method can be used for the alignment film. When an alignment film is provided by the photo-alignment method, the alignment film composition is applied, and the alignment film is formed by irradiating with ultraviolet rays after being arranged in the direction of the transmission axis of the wire grid polarizer in the direction of the slow axis. What to do is desirable. Alternatively, an alignment film may be provided by rubbing. In this case, the alignment film is formed by applying a PVA aqueous solution and rubbing the surface of the coating film several times in a predetermined direction using a cloth or the like. To do.

<< Application process >>
A polymerizable liquid crystal composition is uniformly applied on the surface of the support 35 provided with the alignment film (or on the alignment film provided on the support) to form a coating film 30A (S1).

Application of the polymerizable liquid crystal composition is performed by appropriately applying a liquid crystal composition such as a roll coating method, a gravure printing method, or a spin coating method in which the polymerizable liquid crystal composition is made into a solution state with a solvent or a liquid material such as a melt by heating. It can be performed by a method that develops by various methods. Furthermore, it can be performed by various methods such as a wire bar coating method, an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, and a die coating method. In addition, a coating film can be formed by discharging a liquid crystal composition from a nozzle using an inkjet apparatus.

<< Aging process >>
The coating film 30A is held at the film surface temperature for a predetermined time (aged) to become the coating film 30B in a state where the liquid crystal is aligned (S2). The aging temperature and aging time may be determined according to the liquid crystal compound.

<< UV curing process >>
After the aging step, ultraviolet curing is performed to fix the alignment state of the molecules of the liquid crystal compound. In the ultraviolet curing step, a polymerization reaction by a photocationic polymerization group (photocationic polymerization reaction) and a polymerization reaction by a photoradical polymerization group (photoradical polymerization reaction) are separately performed. In the present specification, the coating film after the first polymerization process in the two-stage polymerization in the ultraviolet curing process is referred to as a liquid crystal semi-fixed film. The procedure of the curing process will be described.

1) Whole surface exposure process The entire surface of the coating film 30B in the state where the liquid crystal phase is aligned is irradiated with ultraviolet rays having an exposure amount of 100 to 2000 mJ / cm ^{2 in} the atmosphere to perform almost uniform exposure on the entire surface of the coating film 30B. (S3). At this time, cationic polymerization mainly proceeds by the action of the cationic polymerization initiator contained in the coating film 30B. In addition, a part of radical polymerization may occur. By this entire surface exposure, a liquid crystal semi-fixed film 30C in which part of the entire surface is crosslinked (partially cured) and the alignment state of the liquid crystal is semi-fixed is obtained. “Semi-fixed” refers to a state in which the liquid crystal composition has lost fluidity in the present invention, and refers to a state before the heat treatment step. For example, it means that only one side functional group of a bifunctional liquid crystal is cross-linked and is in a polymer liquid crystal state. In the case of a polymerizable liquid crystal compound having a cationic polymerization group and a radical photopolymerization group, one of the cationic polymerization group and the radical photopolymerization group is selectively crosslinked. In the entire surface exposure step, a state in which the cationic polymerization group is selectively cross-linked is indicated, but a part of the photo-radical polymerization group may be cross-linked.

2) Initiator application step An initiator supply liquid containing a photoradical polymerization initiator is applied to the surface of the liquid crystal semi-fixed film 30C and dried.

3) Mask exposure step After that, with the stripe pattern mask 40 disposed on the liquid crystal semi-fixed film 30C, UV light having an exposure amount of 30 to 100 mJ / cm ² is applied to the liquid crystal through the stripe pattern mask 40 at room temperature. Irradiate the semi-fixed film 30C (S4). In order to obtain a first retardation region and a second retardation region, the stripe pattern mask 40 has an opening 42 corresponding to the first retardation region and a non-opening portion corresponding to the second retardation region. 44 is formed. Thereby, a region of the liquid crystal semi-fixed film 30 </ b> C that is exposed to the mask opening 42 is exposed, and a pattern exposure that does not expose the portion covered by the mask non-opening 44 is performed. At this time, in the exposed area | region, radical photopolymerization by the effect | action of radical photopolymerization initiator advances and it becomes a phase difference area | region.

4) Heat exposure step Further, the whole substrate is heated at a temperature of 100 to 2000 mJ / hour while being heated for a predetermined time at an optical isotropic region forming temperature of the liquid crystal compound (a temperature higher than a phase transition temperature to the optical isotropic region) under nitrogen. The substrate is exposed to ultraviolet rays having an exposure amount of cm ² so that the liquid crystal forms an optically isotropic region in the region not exposed to the mask, and the alignment of the liquid crystal is maintained in the region exposed to the mask. The pattern retardation film 30D has a fixed alignment state of the entire liquid crystal.

The first pattern phase difference in which the first phase difference region 31 formed of the optically anisotropic region and the second phase difference region 32 formed of the optically isotropic region are formed in a pattern by the above steps. The film 30a can be obtained (S5). A second pattern in which a third retardation region 33 made of an optically anisotropic region and a fourth retardation region 34 made of an optically isotropic region are formed in a pattern by the same process. The retardation film 30b can be obtained.

In the above description, the case where the cationic polymerizable group of the polymerizable liquid crystal compound having a cationic polymerizable group and a radical photopolymerizable group is polymerized first and then the radical photopolymerizable group is polymerized has been described. A patterned phase difference film having a similar optically anisotropic region and an optically isotropic region can also be formed by a procedure of polymerizing first and then polymerizing a cationic polymerizable group. In this case, what contains a radical photopolymerization initiator should just be used for said polymeric liquid crystal composition instead of a cationic polymerization initiator. And the radical photopolymerization initiator application | coating process becomes unnecessary, What is necessary is just to provide a cation initiator application | coating process before carrying out cationic polymerization separately.

<Formation of pattern retardation film having anisotropic regions with different orientation directions>
Next, a manufacturing process of the patterned

phase difference films

30a and 30b in which anisotropic regions having different orientation directions are patterned will be described.

The pattern alignment films having different alignment control capabilities are formed so as to correspond to the first pattern retardation film 30a or the second pattern retardation film 30b. A liquid crystalline compound is disposed thereon, and the liquid crystalline compound is aligned. The liquid crystalline compounds achieve different alignment states depending on the alignment control ability of the pattern alignment film. By fixing the respective alignment states, the band-like regions (or the third retardation region 33 and the fourth retardation region) of the first retardation region 31 and the second retardation region 32 according to the alignment film pattern. A pattern of a band-like region of the phase difference region 34 is formed. The pattern alignment film can be obtained using a photo-alignment method, a rubbing method, a printing method, or the like, as described above. In the photo-alignment method, the photo-alignment film is subjected to mask exposure using a mask corresponding to the stripe pattern, and in the rubbing method, the rubbing alignment film is subjected to mask rubbing using the mask to form a pattern alignment film. Can do. A method using a method using mask exposure on the photo-alignment film is preferable in that large-scale equipment is not required and manufacturing is easy. Details of this method are described in paragraphs [0166] to [0181] of JP2012-032661A, the contents of which are incorporated herein by reference.

Whether the

pattern retardation films

30a and 30b are λ / 2 plates or λ / 4 plates is determined according to the film thickness of the polymerizable liquid crystal composition applied on the alignment film.

Next, elements other than the pattern layer constituting the pattern retardation film will be described.

[Support]
The first pattern retardation film 30a and the second pattern retardation film 30b may be provided with a support, and the support is preferably a transparent support, such as a polyacrylic resin film such as polymethyl methacrylate. , Cellulose resin films such as cellulose triacetate, and cycloolefin polymer films [for example, trade name “ARTON”, manufactured by JSR Corporation, trade name “ZEONOR”, manufactured by Nippon Zeon Co., Ltd.], and the like. The support is not limited to a flexible film but may be a non-flexible substrate such as a glass substrate.

In addition, the pattern retardation film of the present invention may be used while being supported by the support when forming the film, or the support when forming the film is a temporary support, and other support. It may be transferred to the body and peeled off from the temporary support.

Hereinafter, examples and comparative examples of the pattern retardation film of the present invention will be described.

First, preparation of various compositions used for the production of the pattern retardation films of Examples and Comparative Examples will be described.

(Preparation of alignment film composition A)
The composition shown below was stirred and dissolved in a container kept at 80 ° C. to prepare an alignment film composition A.
---------------------------------
Alignment film composition A (parts by mass)
---------------------------------
Pure water 97.2
PVA-205 (Kuraray) 2.8
---------------------------------

(Preparation of alignment film composition B)
<Synthesis of polymer for alignment film composition>
In a reaction vessel equipped with a stirrer, thermometer, dropping funnel and reflux condenser, 100 parts by mass of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 500 parts by mass of methyl isobutyl ketone, and 10 parts by mass of triethylamine Were mixed at room temperature.

Next, 100 parts by mass of deionized water was added dropwise from the dropping funnel to the solution in the reaction vessel over 30 minutes, and then the resulting solution was reacted at 80 ° C. for 6 hours while mixing under reflux. After completion of the reaction, the organic phase was taken out of the solution, and the organic phase was washed with 0.2% by mass ammonium nitrate aqueous solution until the water after washing was neutral. Thereafter, the solvent and water were distilled off under reduced pressure to obtain an epoxy group-containing polyorganosiloxane as a viscous transparent liquid.

This epoxy group-containing polyorganosiloxane was analyzed by 1H-NMR (Nuclear Magnetic Resonance). As a result, a peak based on the oxiranyl group was obtained in the vicinity of the chemical shift (δ) = 3.2 ppm according to the theoretical intensity. It was confirmed that no side reaction of the epoxy group occurred. The epoxy group-containing polyorganosiloxane had a weight average molecular weight Mw of 2,200 and an epoxy equivalent of 186 g / mol.

Next, in a 100 mL three-necked flask, 10.1 parts by mass of the epoxy group-containing polyorganosiloxane obtained above, acrylic group-containing carboxylic acid (trade name “Aronix M-5300”, acrylic acid ω-carboxyl, Toa Gosei Co., Ltd.) 0.5 parts by mass of polycaprolactone (degree of polymerization n≈2), 20 parts by mass of butyl acetate, 1.5 parts by mass of cinnamic acid derivative obtained by the method of Synthesis Example 1 of JP-A-2015-26050, and Tetrabutylammonium bromide (0.3 parts by mass) was charged, and the resulting reaction solution was stirred at 90 ° C. for 12 hours.

After completion of the reaction, the reaction solution was diluted with an equal amount (mass) of butyl acetate and washed with water three times.

The operation of concentrating the obtained solution and diluting with butyl acetate was repeated twice to finally obtain a solution containing a polyorganosiloxane (polymer) having a photoalignable group. The weight average molecular weight Mw of this polymer was 9,000. As a result of 1H-NMR analysis, the content of cinnamate groups in the polymer was 23.7% by mass.

<Preparation of alignment film composition B>
Using butyl acetate as a solvent, the previously prepared polymer and the following compounds D1 and D2 were added in the following amounts to prepare an alignment film composition B.
---------------------------------
Alignment film composition B (parts by mass)
---------------------------------
Butyl acetate 100
Polymer for alignment film composition 4.35
Compound D1 0.48
Compound D2 1.15
---------------------------------

(Preparation of polymerizable liquid crystal composition LC-1)
After preparing the following composition, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as the polymerizable liquid crystal composition LC-1.

The rod-like liquid crystal (LC-1-1) was synthesized based on the method described in JP-A No. 2004-12382. The rod-like liquid crystal (LC-1-1) is a liquid crystal compound having two reactive groups, one of the two reactive groups is an acrylic group which is a radical reactive group, and the other is a cationic reactive group. It is a certain oxetane group. The horizontal alignment agent (LC-1-2) was prepared by Tetrahedron Lett. It was synthesized according to the method described in Journal, Vol. 43, page 6793 (202).
---------------------------------
Polymerizable liquid crystal composition LC-1 (parts by mass)
---------------------------------
Rod-shaped liquid crystal (LC-1-1) 19.57
Horizontal alignment agent (LC-1-2) 0.01
Cationic monomer (OXT-121, manufactured by Toagosei Co., Ltd.) 0.98
Cationic polymerization initiator (Cureure UVI6974, manufactured by Dow Chemical) 0.4
Polymerization control agent (IRGANOX1076, manufactured by BASF) 0.02
Methyl ethyl ketone 80.0
---------------------------------

(Preparation of polymerizable liquid crystal composition LC-2)
After preparing the following composition, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as the liquid crystal composition LC-2.
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Polymerizable liquid crystal composition LC-2 (parts by mass)
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A mixture of the following rod-like liquid crystal compounds 19.57
The following monomers 0.98
The following polymerization initiator 1.17
The following surfactant 0.049
Methyl ethyl ketone 80
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(Preparation of protective layer composition AD-1)
After preparing the following composition, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as the protective layer composition AD-1.
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Protective layer composition AD-1 (parts by mass)
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Random copolymer of methacrylic acid / allyl methacrylate = 20/80 molar ratio (weight average molecular weight 18,000) 8.05 parts by mass radical photopolymerization initiator (2-trichloromethyl-5- (p-styrylstyryl) 1,3,4-oxadiazole)
0.12 parts by mass Hydroquinone monomethyl ether 0.002 parts by mass MegaFuck F-176PF (manufactured by Dainippon Ink & Chemicals, Inc.)
0.05 parts by weight Propylene glycol monomethyl ether acetate 34.80 parts by weight Methyl ethyl ketone 50.54 parts by weight Methanol 1.61 parts by weight ---------------------- -----------

The retardation films of the examples and comparative examples were produced according to the following procedure. This will be described below using the directions of the X, Y, and Z axes in FIG.

[Example 1]
<Formation of two anisotropic regions with different orientation directions (λ / 4 + λ / 4)>
After the alignment film composition B is uniformly applied on the glass substrate in the Y-axis direction using a slit coater, the transmission axis of the wire grid polarizer (product code # 46-636 manufactured by Edmond) is the reference axis (Y The photo-alignment treatment was performed by irradiating with 30 mJ / cm ^{2 of} ultraviolet rays using a PLA-501F exposure machine manufactured by Canon Inc. at 25 ° C. in air at 25 ° C.

Subsequently, a wire grid polarizer, a mask masked with a stripe pattern with a stripe width of 50 μm, and a glass substrate are arranged in this order, and a PLA-501F exposure machine (extra-high pressure mercury lamp) manufactured by Canon Inc. in air at 25 ° C. And is exposed at an exposure amount of 50 mJ / cm ² . At this time, the transmission axis of the wire grid polarizer is arranged so as to be perpendicular to the reference axis, and the angle formed by the reference axis and the major axis direction of the stripe pattern is 89 ° (from −X axis). It is arranged so that the angle θ toward the + Y axis θ = 1 °.

The liquid crystal composition LC-2 was applied on the alignment layer thus obtained. Next, the film was heated and aged at a film surface temperature of 90 ° C. for 60 seconds. Immediately after that, using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) in the air at a film surface temperature of 60 ° C., ultraviolet rays of 500 mJ / cm ² were applied. The entire surface will be irradiated. As a result, a pattern divided into two phase difference regions having a major axis direction angle θ of 1 ° of the mask stripe pattern is formed, the front phase difference is 137.5 nm (λ / 4), and The first phase difference region whose slow axis direction is 0 ° with respect to the reference axis, the front phase difference is 137.5 nm (λ / 4), and the slow axis direction is 90 ° with respect to the reference axis. A patterned phase difference film fractionated into a second phase difference region that was ° was produced. The film thickness of the pattern retardation film was 1.1 μm. Two of these were used as a first pattern retardation film and a second pattern retardation film.

(Production of light control device)
The first polarizer, the first pattern retardation film, the second pattern retardation film, and the second polarizer are laminated in this order. The same pattern retardation film was used for the first pattern retardation film and the second pattern retardation film. The pattern retardation film was arranged so that the angle formed between the reference axis and the slow axis was 0 °, and the angle θ in the major axis direction of the stripe pattern was 1 °. Furthermore, the angle formed by the transmission axis of the first polarizer and the slow axis of the first retardation region of the first pattern retardation film is 45 °, and the transmission axis of the first polarizer and the second axis A light control device was manufactured so that the angle formed with the transmission axis of the polarizer was 90 ° (crossed Nicols).

In this embodiment, the second pattern retardation film is moved in the direction of the movable axis. The direction of the movable axis coincides with the direction of the X axis.

[Example 2]
<Formation of two anisotropic regions with different orientation directions (λ / 2 + λ / 2)>
(Preparation of First Pattern Retardation Film) After applying the alignment film composition B on the glass substrate uniformly in the Y-axis direction using a slit coater as in Example 1, a wire grid polarizer (product code #) 46-636 Edmond) is arranged so that its transmission axis is parallel to the reference axis (Y-axis) in the coating direction, and is exposed to ultraviolet rays using a PLA-501F exposure machine manufactured by Canon Inc. in air at 25 ° C. Was irradiated with 30 mJ / cm ² for photo-alignment treatment.

Subsequently, a wire grid polarizer, a mask masked with a stripe pattern with a stripe width of 50 μm, and a glass substrate are arranged in this order, and a PLA-501F exposure machine (extra-high pressure mercury lamp) manufactured by Canon Inc. in air at 25 ° C. And is exposed at an exposure amount of 50 mJ / cm ² . At this time, the wire grid polarizer is arranged so that the transmission axis is inclined by 45 ° with respect to the reference axis, and the angle θ in the major axis direction of the stripe pattern of the mask is 1 °.

The liquid crystal composition LC-2 was applied on the alignment layer thus obtained. Next, the film was heated and aged at a film surface temperature of 90 ° C. for 60 seconds. Immediately after that, using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) in the air at a film surface temperature of 60 ° C., ultraviolet rays of 500 mJ / cm ² were applied. Irradiate. As a result, a pattern divided into two phase difference regions having an angle θ of 1 ° in the major axis direction of the stripe pattern of the mask is formed. A first phase difference region having a front phase difference of 275 nm (λ / 2) and a slow axis direction of 0 ° with respect to the reference axis; a front phase difference of 275 nm (λ / 2); and A first pattern retardation film composed of a second retardation region having a slow axis direction inclined by 45 ° with respect to the reference axis was produced. The film thickness of the pattern retardation film was 2.1 μm.

(Preparation of second pattern retardation film)
In the first pattern retardation film, the transmission axis of the wire grid polarizer is arranged so as to be inclined by 315 ° with respect to the reference axis, and in the third retardation region, the slow axis direction is 90 ° with respect to the reference axis. In the fourth retardation region, a second pattern retardation film was produced in the same manner as the first pattern retardation film except that the slow axis direction was 315 ° with respect to the reference axis.

(Production of light control device)
As in Example 1, the first polarizer, the first pattern retardation film, the second pattern retardation film, and the second polarizer are stacked in this order. The angle formed by the direction of the reference axis of the first pattern retardation film and the slow axis of the second retardation region is 0 °, and the retardation of the reference axis of the second pattern retardation film and the third retardation region The angle formed by the axis directions is 90 °, and the angle θ in the major axis direction of the stripe pattern is 1 °. Furthermore, the angle formed by the transmission axis of the first polarizer and the slow axis of the first retardation region of the first pattern retardation film is 45 °, the transmission axis of the first polarizer and the second pattern position. The angle formed by the slow axis of the third retardation region of the retardation film is 135 °, and the angle formed by the transmission axis of the first polarizer and the transmission axis of the second polarizer is 90 ° (crossed Nicols). A light control device arranged so as to be was prepared.

In the present embodiment, the second pattern retardation film is moved in the direction of the movable axis as in the first embodiment. The direction of the movable axis coincides with the direction of the X axis.

[Example 3]
<Formation of isotropic and anisotropic regions (iso + λ / 2)>
(Preparation of first pattern retardation film)
In place of the alignment film composition B used in Example 1, the alignment film composition A prepared above was uniformly applied on the glass substrate in the Y-axis direction using a slit coater, and then in an oven at 100 ° C. It was dried for 2 minutes to obtain a glass substrate with an alignment film having a thickness of 0.5 μm.

A rubbing treatment was performed in parallel with the reference axis, and the liquid crystal composition LC-1 was coated on the rubbing surface. Next, the film surface was aged for 60 seconds at a film surface temperature of 80 ° C., and then immediately irradiated with 500 mJ / cm ² of ultraviolet light using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) at a film surface temperature of 70 ° C. did.
The liquid crystal material thus obtained was coated with the protective layer composition AD-1 prepared above, dried at a film surface temperature of 80 ° C. for 60 seconds, and then air-laminated at 25 ° C. by Canon Inc. PLA- Using a 501F exposure machine (extra-high pressure mercury lamp), exposure was performed using a mask with a 50 μm stripe pattern masked at an exposure amount of 50 mJ / cm ² . At this time, the angle formed between the reference axis and the major axis direction of the stripe pattern was 89 ° (angle θ = 1 ° from −X axis to + Y axis).

Then, the long axis of the stripe pattern of the mask is obtained by exposing the whole substrate at 200 ° C. with an exposure amount of 500 mJ / cm ² for 5 minutes under nitrogen with an air-cooled metal halide lamp (made by Eye Graphics Co., Ltd.). A pattern divided into two phase difference regions having a direction angle θ of 1 ° is formed. A first phase difference region having a front phase difference of 275 nm (λ / 2) and a slow axis direction of 0 ° with respect to the reference axis; and a second phase difference region being an optically isotropic region; A first pattern retardation film in which a pattern fractionated into two was formed was produced. The thickness of the retardation film was 2.1 μm.

(Preparation of second pattern retardation film)
In the first pattern retardation film, except that the direction of the slow axis of the first retardation region is 90 °, the third retardation region, and the optically isotropic region is the fourth retardation region. A second pattern retardation film was produced in the same manner as the first pattern retardation film.

(Production of light control device)
The first polarizer, the first pattern retardation film, the second pattern retardation film, and the second polarizer were laminated in this order. The angle formed by the transmission axis of the first polarizer and the slow axis of the retardation region (first retardation region) of the first pattern retardation film is 45 °, the transmission axis of the first polarizer and the second The angle between the retardation layer (third retardation region) of the pattern retardation film and the slow axis of the pattern retardation film is 135 °, and the stripe pattern of the first pattern retardation film and the second pattern retardation film The major axis direction angle θ is 1 °. Furthermore, a light control device was manufactured in which the angle formed by the transmission axis of the first polarizer and the transmission axis of the second polarizer was 90 ° (crossed Nicols).

[Example 4]
Example 3 Example 3 is the same as Example 3 except that the pattern width of the stripe pattern of the first and second pattern retardation films is 200 μm and the angle θ in the major axis direction of the stripe pattern is 10 °. 4 dimmers were produced.

[Example 5]
In the same manner as in Example 3, a first pattern retardation film and a second pattern retardation film are produced. However, the light control device of Example 5 was manufactured in the same manner as Example 3 except that the pattern width of the stripe pattern was 500 μm and the angle θ in the major axis direction of the stripe pattern was 10 °.

[Example 6]
Example 3 is the same as Example 3 except that the pattern width of the stripe pattern of the first and second pattern retardation films is 5 μm and the angle θ in the major axis direction of the stripe pattern is 0.5 °. The light control device of Example 6 was produced.

[Comparative Example 1]
In Example 3, a comparative example is the same as Example 3 except that the pattern width of the stripe pattern of the first and second pattern retardation films is 1000 μm and the angle θ in the major axis direction of the stripe pattern is 90 °. 1 light control device was produced.

[Comparative Example 2]
In Example 3, a comparative example is the same as Example 3 except that the pattern width of the stripe pattern of the first and second pattern retardation films is 50 μm and the angle θ in the major axis direction of the stripe pattern is 90 °. The light control device of 2 was produced.

(Evaluation criteria)
The measured gradation change was evaluated based on the following criteria by sensory evaluation.

A: Good (gradation change is continuous)
B: Slightly good (change in gradation can be regarded as continuous and acceptable)
C: Defect (change in gradation varies depending on location)

The relative movement amount is a relative movement amount necessary for moving the pattern retardation film before changing from a bright state to a dark state. The longer this distance, the easier the alignment. Further, as the pattern width becomes narrower, it is possible to realize a continuous gradation.

Table 1 summarizes the configuration and evaluation results of each example.

As shown in Table 1, the light control devices of Examples 1 to 5 were able to ensure a sufficient amount of movement for performing continuous light control. Among these, Examples 1, 3, and 4 have a sufficiently narrow pattern width and good gradation change, and can perform continuous light control. In Example 5, since the pattern width is slightly wide, it is presumed that the gradation change is slightly good. However, even if θ is 10 °, a sufficient amount of movement can be secured. In Comparative Example 1, the pattern width is wide and the tone of two gradations is obtained, but it can be inferred that continuous light control is possible by setting the pattern width to 200 μm or less.
From the above, the pattern width is 500 μm or less, more preferably the pattern width is 200 μm or less.

In addition, comparing Examples 1 to 3, it is more preferable to use a combination of an iso region and a λ / 2 region or a combination of two λ / 4 regions as a method for producing a pattern retardation film. In the combination of the two λ / 2 regions in Example 2, the slow axis direction of the liquid crystal rotates by 90 ° between two adjacent phase difference regions, so that a liquid crystal alignment defect occurs at the boundary portion of the phase difference region. Therefore, it is presumed that the gradation change is B evaluation. On the other hand, in the combination of the λ / 4 regions of Example 1, it is surmised that the slow axis direction rotates only 45 ° between the phase difference regions, so that an alignment defect at the boundary portion hardly occurs and a good result is obtained. In Comparative Example 2, continuous light control is possible with a narrow pattern width, but it is difficult to control the movement amount for light control with a small relative movement amount. Even with the same pattern width, a sufficient amount of movement can be ensured by setting θ to 1 ° as in the third embodiment. In Example 6, the pattern width is considerably narrow, and continuous light control can be performed. Thus, even when the pattern width is quite narrow, the amount of movement can be secured by tilting θ to 0.5 °.

DESCRIPTION OF SYMBOLS 10 Light control apparatus 12 Light control part 14 Moving part 16 Control part 20 1st polarizer 22 2nd polarizer 24 Phase difference part 30a 1st pattern phase difference film 30b 2nd pattern phase difference film 31 1st Phase difference region 32 Second phase difference region 33 Third phase difference region 34 Fourth phase difference region 40 Pattern mask 42 Opening 44 Non-opening

Claims

A first polarizer, a first pattern retardation film, a second pattern retardation film, and a second polarizer are stacked in this order, and the first pattern retardation film and the second pattern retardation film are stacked in this order. A light control device capable of adjusting the entire transmitted light amount by moving the relative position of the pattern retardation film along a uniaxial direction,
The first pattern phase difference film and the second pattern phase difference film have two widths in which at least one of the phase difference value and the direction of the slow axis is alternately arranged with the same width. Formed in a stripe pattern of 1 μm or more to 500 μm or less,
The light control apparatus which has the inclination of the range whose long side direction of the said striped pattern is larger than 0 degree and smaller than 90 degrees with respect to the said uniaxial direction.
The angle θ formed by the long-side direction of the stripe pattern of the first pattern retardation film and the second pattern retardation film and the uniaxial direction, and the width w of the stripe pattern are
0.5mm ≦ w / sinθ ≦ 100mm
The light control device according to claim 1, satisfying the relationship:
At least one of the first pattern retardation film and the second pattern retardation film has a retardation area where the retardation value is zero and a retardation area where the retardation value has a retardation value other than zero. The light control device according to claim 1, wherein the light control device is a pattern retardation film having the stripe-like pattern formed in step (1).
At least one of the first pattern phase difference film and the second pattern phase difference film is a phase difference region in which an angle formed by the slow axes of the phase difference regions adjacent to each other is 40 ° to 50 °. The light control device according to claim 1, wherein the light control device is a patterned phase difference film having the formed stripe pattern.