WO2012039354A1

WO2012039354A1 - Illuminating device and display device

Info

Publication number: WO2012039354A1
Application number: PCT/JP2011/071201
Authority: WO
Inventors: 増田　岳志
Original assignee: シャープ株式会社
Priority date: 2010-09-22
Filing date: 2011-09-16
Publication date: 2012-03-29

Abstract

Provided is an illuminating device, which has reduced weight, while suppressing deterioration of uniformity of illuminating light. A backlight device (illuminating device) (10) is provided with a plurality of light sources (30), and a plurality of light guide bars (20). The light guide bars are disposed at predetermined intervals, and each of the light guide bars include a processing section (22h), which changes the travelling direction of light emitted from the light sources to the direction that is suitable for outputting the light to the outside, and a trapezoidal section (22a), which deflects light outputted from the processing section and outputs the deflected light to the outside. The trapezoidal section includes the tilted surface (22g), which is tilted with respect to the side surface (22f) having the processing section formed thereon.

Description

Illumination device and display device

The present invention relates to an illumination device and a display device, and more particularly, to an illumination device and a display device including a light source and a light guide rod that guides light from the light source.

Conventionally, a direct backlight device and an edge light (side light) backlight device are known as illumination devices that illuminate a display panel (illuminated member).

In the direct type backlight device, the light source is two-dimensionally (planar) arranged at a position directly below the display panel. Further, in a direct type backlight device, it is difficult to reduce the number of light sources in order to ensure uniformity of illumination light while suppressing an increase in the thickness of the backlight device. For this reason, it is difficult to reduce the weight of the backlight device, and it is difficult to reduce the cost.

On the other hand, in the edge light type backlight device, a light guide plate is arranged at a position directly below the display panel, and a light source is arranged around the light guide plate. For this reason, in the edge light type backlight device, the number of light sources can be reduced as compared with the direct type backlight device.

In addition, the light guide plate is usually formed by a single member having an area comparable to that of the display panel, but a plurality of light guide bars are in contact with each other as in a surface coloring device (illumination device) of Patent Document 1, for example. There is also known a structure in which the light guide is configured by arranging in such a manner.

JP 2008-218223 A

However, in the edge light type backlight device (illumination device), the light guide plate and the light guide body including a plurality of light guide rods have the same area as the display panel (illuminated member). There is a problem that it is difficult to reduce the weight. It is also difficult to reduce costs.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a lighting device that can be reduced in weight while suppressing a decrease in the uniformity of illumination light. It is to provide a display device.

In order to achieve the above object, an illumination device according to a first aspect of the present invention is an illumination device arranged on the back side of a member to be illuminated, and is provided with a plurality of light sources and light from the light sources, A plurality of light guide rods that guide light from the light source, the plurality of light guide rods are arranged at a predetermined interval from each other, and the light guide rods are suitable for the outward emission of the light traveling direction from the light source Including a light emitting processing section that is changed in a different direction and a light deflecting section that is provided in a region different from the light emitting processing section and deflects the light from the light emitting processing section and emits the light to the outside. The deflecting portion includes an inclined surface that is inclined with respect to the surface on which the light emitting processing portion is formed.

In the illuminating device according to the first aspect, as described above, by providing a plurality of light guide rods for guiding light from the light source, unlike the direct illuminating device, the light source is positioned directly below the illumination target member. Therefore, the thickness of the lighting device and the display device can be reduced.

In the lighting device according to the first aspect, as described above, the plurality of light guide bars are arranged at a predetermined interval from each other, whereby the area of the plurality of light guide bars, for example, the area of the illuminated member is determined. Therefore, the lighting device can be reduced in weight. In addition, the cost of the lighting device can be reduced.

When a plurality of light guide bars are arranged at a predetermined interval from each other, if the thickness of the lighting device is reduced, the uniformity of the illumination light may be reduced. However, in the illumination device according to the first aspect, as described above, the light emitting processing unit that causes the light guide rod to change the traveling direction of light from the light source to a direction suitable for external emission, and the light emitting processing unit. And a light deflecting section for deflecting the light from the light and emitting it to the outside. As a result, the light deflection unit can control the traveling direction of the light emitted from the light guide rod. For example, compared to the portion directly above between the adjacent light guide rods, It can suppress that a part (vicinity part of a light-guide rod) becomes bright. That is, it can suppress that the uniformity of illumination light falls.

Also, by providing the light deflection unit in a region different from the light emitting processing unit, the traveling direction of the light emitted from the light deflection unit can be easily controlled.

Also, in the illumination device according to the first aspect, as described above, the light deflection unit includes an inclined surface that is inclined with respect to the surface on which the light emitting processing unit is formed. Thereby, the light from the light emitting processing part can be easily deflected and emitted so as to go to the portion directly above between the adjacent light guide bars by the light deflecting part.

In the illumination device according to the first aspect, preferably, the light deflection section is formed closer to the illuminated member than the light emission processing section. Since the portion of the light guide bar on the illuminated member side has a shorter distance to the illuminated member (or optical member) than the portion of the light guide rod on the side opposite to the illuminated member, the light guide rod is illuminated. Uniformity of light (illumination light) emitted from the member side portion is likely to be lowered. For this reason, as described above, the light deflection portion is formed on the illuminated member side of the light emitting processing portion by forming the light deflection portion on the illuminated member side of the light emitting processing portion. It can suppress that the uniformity of the light radiate | emitted from the part by the side of the to-be-illuminated member of a light guide rod falls. Thereby, it can suppress effectively that the uniformity of illumination light falls.

In the illumination device according to the first aspect, preferably, the light emission processing portion is formed in a portion of the light guide bar opposite to the illuminated member. If comprised in this way, since the distance from the process part for light emission to a to-be-illuminated member (or optical member) can be lengthened, it can suppress that the uniformity of illumination light falls.

In the illumination device according to the first aspect, preferably, the light guide bar includes a side surface that intersects with the arrangement direction of the plurality of light guide bars, and the light emitting processing portion is formed on the side surface. If comprised in this way, compared with the case where the process part for light emission is formed in the upper surface and lower surface (surface parallel to the sequence direction of a plurality of light guide rods) of a light guide rod, for example, Light emitted from the upper surface of the substrate can be reduced. Thereby, it can suppress that the part right above a light-guide rod becomes bright. That is, it can suppress more that the uniformity of illumination light falls.

In the illumination device in which the light emitting processing part is formed on the side surface, the side surface may be substantially orthogonal to the arrangement direction of the plurality of light guide bars.

In the lighting device according to the first aspect, the inclined surface preferably includes a curved surface. If comprised in this way, compared with the case where a light deflection | deviation part contains a flat inclined surface, it can suppress more easily that the part right above an adjacent light guide bar becomes bright. In addition, by forming the light deflection unit so as to include a curved surface, it is possible to suppress the formation of corners in the light deflection unit. Thereby, it can suppress that the advancing direction of the light radiate | emitted from an optical deflection | deviation part changes discontinuously.

In the illumination device according to the first aspect, preferably, the light deflection unit includes a prism group, and the prism group has an inclined surface. If comprised in this way, it can suppress more more easily that the part right above an adjacent light guide bar becomes bright. Moreover, since the thickness (height) of the light guide rod can be reduced by configuring the light deflection unit to include the prism group, the thickness of the illumination device can be reduced.

In the lighting device according to the first aspect, the inclined surface is preferably inclined with respect to the arrangement direction of the plurality of light guide bars. If comprised in this way, it can suppress easily that the directly upper part of a light guide bar becomes bright compared with the directly upper part between adjacent light guide bars, for example.

In the illumination device according to the first aspect, preferably, the light guide bar is disposed on the light source side, and has a light propagation portion having a function of propagating light, a light emitting processing portion, and a light formed with a light deflection portion. And an emission part. If comprised in this way, light can be radiate | emitted from the desired position of the longitudinal direction of a light-guide rod.

In the illumination device in which the light guide rod includes a light propagation part and a light emission part, the light deflection part may not be provided in the light propagation part but may be provided in the light emission part.

In the illuminating device in which the light guide rod includes a light propagation part and a light emission part, preferably, at the boundary portion between the light propagation part and the light emission part, the light deflection part of the light emission part is located outside the light propagation part. It is formed to protrude. If comprised in this way, since it can suppress that a light is radiate | emitted outside from the surface at the side of the light emission part of a light propagation part, it can suppress that the utilization efficiency of light falls.

The illumination device according to the first aspect preferably further includes an optical member disposed on the illuminated member side of the light guide rod, and a reflecting member disposed on the opposite side of the illuminated member of the light guide rod. The distance from the light guide bar to the optical member is larger than the distance from the light guide bar to the reflection member. If comprised in this way, a light guide rod can be arrange | positioned away from a to-be-illuminated member (or optical member). Thereby, it can suppress more that the uniformity of illumination light falls.

In the illumination device according to the first aspect, the light guide rod includes a rectangular portion having a rectangular cross section and a trapezoidal portion having a trapezoidal cross section, and the light emitting processing portion is formed in the rectangular portion. The light deflection part may be formed in a trapezoidal part.

In the lighting device according to the first aspect, the plurality of light guide bars constitute one or more light guide bar groups, and the one light guide bar group has a plurality of different lengths. May be included. Further, if the light guide rod is provided with a light propagation part disposed on the light source side and having a function of propagating light, and a light emission part in which the light emission part and the light deflection part are formed, the light source is connected to the illumination device. The light emitting part of the light guide rod can be arranged at an arbitrary position of the lighting device while being arranged at the edge. That is, an arbitrary number of light emitting portions of the light guide rod can be arranged in the longitudinal direction of the lighting device, and an arbitrary number can be arranged in the short direction of the lighting device. Thereby, an illuminating device can be divided into arbitrary numbers to both a longitudinal direction and a transversal direction, and the intensity | strength of illumination light can be controlled for every divided area.

In the illumination device including a plurality of light guide bars in which the one light guide bar group has a different length, preferably, the light guide bar is disposed on the light source side and has a light propagation unit having a function of propagating light. In the light guide rod group, the plurality of light emitting portions are arranged substantially in a straight line including the light emitting processing portion and the light emitting portion on which the light deflection portion is formed. If comprised in this way, when arrange | positioning a some light guide rod group side by side, a some light-emitting part can be made easy to arrange | position uniformly within an illuminating device.

In the illumination device including a plurality of light guide bars each having a different length from each other, the light guide bar is disposed on the light source side and has a function of propagating light, and light emission. The plurality of light guide rods having different lengths may include light propagation portions having mutually different lengths.

A display device according to a second aspect of the present invention includes the illumination device configured as described above and a member to be illuminated illuminated by the illumination device. If comprised in this way, the display apparatus which can be reduced in weight can be obtained, suppressing the uniformity of illumination light falling.

As described above, according to the present invention, it is possible to easily obtain an illumination device and a display device that can be reduced in weight while suppressing the uniformity of illumination light from being lowered.

1 is a cross-sectional view illustrating a schematic structure of a liquid crystal display device according to a first embodiment of the present invention. It is a top view for demonstrating the structure of the backlight apparatus shown in FIG. It is sectional drawing which showed the structure of the backlight apparatus shown in FIG. It is the perspective view which showed the structure of the light guide bar shown in FIG. It is the side view which showed the structure of the light guide bar shown in FIG. FIG. 2 is an enlarged cross-sectional view illustrating a structure of a light guide bar illustrated in FIG. 1. It is sectional drawing which showed the structure of the backlight apparatus provided with the light guide bar in which the inclined surface is not formed. FIG. 3 is an enlarged view showing the structure of the light guide bar of Example 1. 6 is an enlarged view showing a structure of a light guide bar of Comparative Example 1. FIG. It is the figure which showed the illumination intensity distribution of the light which reaches | attains the diffuser plate of the backlight apparatus by Example 1 and Comparative Example 1. FIG. It is the perspective view which showed the structure of the light guide rod of the backlight apparatus by 2nd Embodiment of this invention. It is the perspective view which showed the structure of the light guide rod of the backlight apparatus by 3rd Embodiment of this invention. FIG. 6 is a cross-sectional view illustrating a structure of a backlight device according to a fourth embodiment of the present invention. FIG. 9 is a cross-sectional view illustrating a structure of a backlight device according to a fifth embodiment of the present invention. It is a top view for demonstrating the structure of the backlight apparatus by 6th Embodiment of this invention. It is the top view which showed the structure of the light guide bar and light guide bar group which were shown in FIG. It is sectional drawing which showed the schematic structure of the liquid crystal display device by the 1st modification of this invention. It is a top view for demonstrating the structure of the backlight apparatus shown in FIG. It is the perspective view which showed the structure of the light guide bar shown in FIG. It is the expanded sectional view which showed the structure of the light guide bar shown in FIG. It is a top view for demonstrating the structure of the backlight apparatus by the 2nd modification of this invention. It is a top view for demonstrating the structure of the backlight apparatus by the 3rd modification of this invention. It is the top view which showed the structure of the light guide bar and light guide bar group which were shown in FIG. It is the top view which showed the structure of the light guide bar by the 4th modification of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In order to facilitate understanding, even a cross-sectional view may not be hatched, or a side view or perspective view may be hatched.

(First embodiment)
First, the structure of the liquid crystal display device 1 according to the first embodiment of the invention will be described with reference to FIGS.

The liquid crystal display device 1 according to the first embodiment of the present invention includes a liquid crystal display panel 2 and a backlight device 10 that illuminates the liquid crystal display panel 2 as shown in FIG. The liquid crystal display device 1 is an example of the “display device” in the present invention, and the liquid crystal display panel 2 is an example of the “illuminated member” in the present invention. The backlight device 10 is an example of the “illumination device” in the present invention.

The liquid crystal display panel 2 includes an AM substrate (active matrix substrate) 2a and a counter substrate 2b disposed to face the AM substrate 2a. A liquid crystal (not shown) is sealed between the AM substrate 2a and the counter substrate 2b. Polarizing

films

2c and 2d are provided on the light receiving surface (back surface) side of the AM substrate 2a and the light emitting surface (front surface) side of the counter substrate 2b, respectively. The liquid crystal display panel 2 functions as a display panel when illuminated by the backlight device 10.

The backlight device 10 is an edge light (side light) type backlight device, and includes a plurality of light guide bars 20 and a plurality of light sources 30 arranged to oppose a light incident surface 21c described later of the light guide bars 20. The reflection sheet 11 disposed on the rear side (lower side) of the light guide bar 20, the diffusion plate 12 and the optical sheet 13 disposed on the front side (upper side) of the light guide bar 20, and a backlight chassis for storing them. 40. The reflection sheet 11 is an example of the “reflection member” in the present invention, and the diffusion plate 12 and the optical sheet 13 are examples of the “optical member” in the present invention.

The light guide rod 20 is formed of a light-transmitting resin or the like, and has a function of guiding light while totally reflecting light from the light source 30 and emitting the light from a light emitting unit 22 described later. The detailed structure of the light guide bar 20 will be described later.

The light source 30 is configured to emit light toward the light guide bar 20. The light source 30 is configured by, for example, a white LED (Light Emitting Diode) that emits white light. Further, the light source 30 may be composed of, for example, a red light emitting element, a green light emitting element, and a blue light emitting element, or may be composed of a blue light emitting element and a phosphor that converts part of the blue light into yellow light. May be.

Further, the plurality of light sources 30 are attached to the mounting substrate 31 as shown in FIG. In the first embodiment, for example, two mounting substrates 31 are arranged on one side in the short side direction (A direction) of the liquid crystal display panel 2 (see FIG. 1).

The backlight device 10 is configured so that the intensity of light emitted from the light source 30 can be adjusted for each light source 30. For this reason, since it is possible to control the intensity of illumination light for each of the plurality of light guide bars 20 according to the display image, it is possible to increase the contrast of the display image and It is possible to reduce power consumption.

As shown in FIG. 1, the reflection sheet 11 has a function of reflecting, to the liquid crystal display panel 2 side, light that travels toward the side opposite to the liquid crystal display panel 2 out of the light emitted from the light guide bar 20. .

The diffusion plate 12 has a function of diffusing light from the light guide rod 20 (or the reflection sheet 11) and emitting it to the liquid crystal display panel 2 side (optical sheet 13 side).

The optical sheet 13 is composed of, for example, a plurality of sheets such as a prism sheet and a lens sheet, and has a function of condensing light from the diffusion plate 12 at a predetermined viewing angle.

Note that the diffusion plate 12 and the optical sheet (such as a prism sheet or a lens sheet) 13 are provided as necessary and may be omitted.

The backlight chassis 40 is formed, for example, by bending a metal plate.

Next, the detailed structure of the light guide bar 20 will be described.

In the first embodiment, as shown in FIG. 2, the plurality of light guide bars 20 are arranged so as to extend in the short direction (A direction) of the liquid crystal display panel 2 (see FIG. 1). The panels 2 are arranged (arranged) in the longitudinal direction (B direction (direction orthogonal to the A direction)) at a predetermined interval. A plurality of light guide bars 20 are arranged (arranged) along the longitudinal direction (B direction) of the liquid

crystal display panel

2, and 1 along the short direction (A direction) of the liquid crystal display panel 2. One is arranged.

In the first embodiment, as shown in FIG. 3, the distance from the light guide bar 20 (front surfaces 21d and 22d described later) to the diffusion plate 12 is reflected from the light guide bar 20 (back surfaces 21e and 22e described later). The light guide bar 20 is disposed so as to be larger than the distance to the sheet 11.

In the first embodiment, as shown in FIG. 4, the light guide bar 20 is disposed on the light source 30 side, and has a light propagation part 21 having a function of propagating (light guiding) light from the light source 30, and light. And a light emitting part 22 for emitting light from the propagation part 21 to the outside.

As shown in FIG. 3, the light propagation part 21 is disposed on the liquid crystal display panel 2 side, is disposed on the side opposite to the liquid crystal display panel 2, and has a trapezoidal section 21 a having a trapezoidal cross section. And a rectangular portion 21b. Further, as shown in FIGS. 3 and 4, the light propagation unit 21 includes a light incident surface 21c (see FIG. 2) on which light emitted from the light source 30 (see FIG. 2) is incident, and a front surface (upper surface) 21d. , A back surface (lower surface) 21e, a pair of side surfaces 21f, and two inclined surfaces 21g disposed between the front surface 21d and the side surface 21f.

The light incident surface 21c is formed perpendicular to the A direction as shown in FIG. The front surface 21d and the back surface 21e are formed in parallel to each other, and are formed perpendicular to the thickness direction (C direction) of the backlight device 10. As shown in FIGS. 3 and 4, the pair of side surfaces 21 f are formed in parallel to each other and perpendicular to the B direction.

The inclined surface 21g is formed so as to be inclined with respect to the arrangement direction (B direction) of the light guide rods 20 and the side surface 21f.

Further, in the first embodiment, as shown in FIG. 4, the light emitting part 22 is formed to have the same cross-sectional shape as the light propagation part 21.

Specifically, as shown in FIGS. 3 and 4, the light emitting section 22 is disposed on the liquid crystal display panel 2 side, and has a trapezoidal section 22 a (see FIG. 3) having a trapezoidal cross section, and a liquid crystal display panel. 2 and a rectangular portion 22b (see FIG. 3) having a rectangular cross section. That is, the trapezoidal portion 22a is formed in a region different from the later-described processed portion 22h of the rectangular portion 22b. The trapezoidal portion 22a is an example of the “light deflecting portion” in the present invention.

The light emitting portion 22 includes a tip surface 22c formed on the side opposite to the light incident surface 21c (see FIG. 5) of the light propagating portion 21 (the side opposite to the light source 30), a front surface (upper surface) 22d, It includes a back surface (lower surface) 22e, a pair of side surfaces 22f, and two inclined surfaces 22g disposed between the front surface 22d and the side surfaces 22f.

The front end surface 22c is formed perpendicular to the A direction. The front surface 22d and the back surface 22e are formed in parallel to each other and are formed perpendicular to the C direction. The pair of side surfaces 22f are formed in parallel to each other and are formed perpendicular to the B direction (the arrangement direction of the light guide rods 20). That is, the pair of side surfaces 22f are orthogonal to (intersect) the B direction.

Further, in the first embodiment, as shown in FIGS. 3 to 5, the pair of side surfaces 22f of the light emitting unit 22 is changed in a traveling direction of light from the light source 30 to a direction suitable for external emission. The processed portion 22h is formed. That is, the processing unit 22h has a function of refracting or reflecting light guided while being totally reflected so that it can be emitted to the outside without being totally reflected. For this reason, as shown in FIGS. 3 and 6, the light that has reached the processed portion 22h of the one side surface 22f is mainly emitted from the surface disposed on the other side (the other side surface 22f and the inclined surface 22g). . The hatched areas in FIGS. 3 to 5 indicate the processed portion 22h. The processing portion 22h is an example of the “light emitting processing portion” in the present invention.

In the first embodiment, as shown in FIGS. 4 and 5, the processed portion 22 h is formed so as to extend along the direction in which the light guide bar 20 extends (direction A). The processed portion 22h is formed in a belt shape having a width (height) that is substantially the same as the length of the side surface 22f in the C direction.

As illustrated in FIG. 6, the processing unit 22 h may be formed by, for example, a plurality of triangular prisms, or a lens (not shown) or white ink (white paint) is used instead of a prism. You may form by the dot part (not shown) by dot type printing processing.

When the processing part 22h is formed by a prism or a lens, the traveling direction of the light from the light source 30 is changed by being refracted or reflected by the processing part 22h, and the light is emitted outside without satisfying the total reflection condition. On the other hand, when the processing portion 22h is formed by a dot portion formed by dot printing, the traveling direction of the light from the light source 30 is changed by being reflected or diffused by the processing portion 22h, so that the total reflection condition is not satisfied. Emitted.

In the first embodiment, as shown in FIGS. 3 and 4, the inclined surface 22g is disposed closer to the liquid crystal display panel 2 than the processed portion 22h (side surface 22f). The inclined surface 22g has a flat surface. The inclined surface 22g is formed to be inclined with respect to the arrangement direction (B direction) of the light guide bars 20 and the side surface 22f. The inclined surface 22g has a function of deflecting the light from the processing portion 22h (changing the traveling direction of the light) and emitting it to the outside.

Here, as shown in FIG. 7, when the light guide rod 1020 having no inclined surface 22 g is used, the light emitted from the side surface 1022 f is directly above the light guide rod 1020 in the diffusion plate 12. It is easy to reach the part (around the part directly above).

On the other hand, in the first embodiment, as shown in FIG. 3, the light guide rod 20 is formed with the inclined surface 22 g, so that the light emitted from the light guide rod 20 is emitted from the light guide rod 1020. Compared with light, the traveling direction of light approaches the B direction (the arrangement direction of the light guide bars 20). For this reason, the light emitted from the inclined surface 22g easily reaches the portion directly above the adjacent light guide rods 20 in the diffusion plate 12.

In the first embodiment, as described above, by providing the plurality of light guide rods 20 that guide the light from the light source 30, unlike the direct-type backlight device, the light source 30 is directly below the liquid crystal display panel 2. Since it is not necessary to arrange | position in the position, the thickness of the backlight apparatus 10 and the liquid crystal display device 1 can be made small.

In the first embodiment, as described above, the plurality of light guide bars 20 are arranged at a predetermined interval from each other, whereby the area of the plurality of light guide bars 20 is set to, for example, the area of the liquid crystal display panel 2. Therefore, the backlight device 10 can be reduced in weight. In addition, the cost of the backlight device 10 can be reduced.

Note that, when the plurality of light guide bars 20 are arranged at a predetermined interval from each other, if the thickness of the backlight device 10 is reduced, the uniformity of the illumination light may be reduced. However, in the first embodiment, as described above, the light guide rod 20 is caused to change the traveling direction of light from the light source 30 to a direction suitable for external emission, and the light from the processing portion 22h is deflected. And a trapezoidal portion 22a for emitting light to the outside. Thereby, since the advancing direction of the light radiate | emitted from the light guide rod 20 is controllable by the trapezoidal part 22a, compared with the directly upper part between adjacent light guide rods 20, the light guide rod 20 of FIG. It is possible to prevent the portion directly above (the vicinity of the light guide bar 20) from becoming bright. That is, it can suppress that the uniformity of illumination light falls.

Further, by providing the trapezoidal portion 22a (inclined surface 22g) in a region different from the processing portion 22h, the traveling direction of the light emitted from the trapezoidal portion 22a can be easily controlled.

In the first embodiment, as described above, the trapezoidal portion 22a is provided with the inclined surface 22g that is inclined with respect to the side surface 22f on which the processed portion 22h is formed. As a result, the trapezoidal portion 22a (inclined surface 22g) allows the light from the processing portion 22h to be easily deflected and emitted so as to be directed directly above the portion between the adjacent light guide rods 20. .

In the first embodiment, as described above, the trapezoidal portion 22a is formed closer to the liquid crystal display panel 2 than the processed portion 22h. The portion of the light guide bar 20 on the liquid crystal display panel 2 side has a shorter distance to the liquid crystal display panel 2 (diffusion plate 12) than the part of the light guide bar 20 on the side opposite to the liquid crystal display panel 2. The uniformity of the light (illumination light) emitted from the portion of the light bar 20 on the liquid crystal display panel 2 side tends to be lowered. For this reason, as described above, the trapezoidal portion 22a is formed on the liquid crystal display panel 2 side of the light guide bar 20 by forming the trapezoidal portion 22a on the liquid crystal display panel 2 side with respect to the processing portion 22h. It can suppress, and it can suppress that the uniformity of the light radiate | emitted from the part by the side of the liquid crystal display panel 2 of the light guide bar 20 falls. Thereby, it can suppress effectively that the uniformity of illumination light falls.

In the first embodiment, as described above, the processed portion 22h is formed in a portion of the light guide bar 20 opposite to the liquid crystal display panel 2. Thereby, since the distance from the process part 22h to the liquid crystal display panel 2 (diffusion plate 12) can be lengthened, the uniformity of illumination light can be improved.

In the first embodiment, as described above, the processed portion 22h is formed on the side surface 22f that is orthogonal to (intersects with) the arrangement direction (B direction) of the light guide bars 20. Thereby, compared with the case where the process part 22h is formed in the front surface 22d and the back surface 22e (surface parallel to B direction) of the light guide rod 20, for example, the light radiate | emitted from the front surface 22d of the light guide rod 20 is used. Can be reduced. Thereby, it can suppress that the part right above the light guide bar 20 (part corresponding to the light guide bar 20) of the liquid crystal display panel 2 becomes bright. That is, it can suppress more that the uniformity of illumination light falls.

In the first embodiment, as described above, the distance from the light guide bar 20 to the diffusion plate 12 is made larger than the distance from the light guide bar 20 to the reflection sheet 11. Thereby, the light guide bar | burr 20 can be arrange | positioned away from the liquid crystal display panel 2 (diffusion plate 12). Thereby, it can suppress more that the uniformity of illumination light falls.

Next, referring to FIG. 8 to FIG. 10, it was carried out to confirm that the uniformity of the illumination light can be improved by forming the inclined surface 22 g (trapezoidal portion 22 a) on the light guide rod 20. A confirmation experiment will be described.

In this confirmation experiment, the illuminance distribution of light reaching (incident) the diffusion plate 12 was obtained by simulation for Example 1 corresponding to the first embodiment and Comparative Example 1 corresponding to FIG.

In Example 1, as shown in FIG. 8, a light guide rod 20 having an inclined surface 22g was used. The width (the width of the back surface 22e) W1 of the light guide bar 20 was 4.2 mm, and the height (thickness) H1 of the light guide bar 20 was 4.2 mm. Further, the width W2 of the front surface 22d was 2.4 mm, and the height H2 of the side surface 22f (processed portion 22h) was 1.5 mm.

In Comparative Example 1, as shown in FIG. 9, a light guide rod 1020 having no inclined surface 22g was used. The width W1001 of the light guide bar 1020 was 4.2 mm, and the height (thickness) H1001 of the light guide bar 1020 was 4.2 mm. Further, the height H1002 of the processed portion 1022h was set to 1.5 mm. The remaining structure of Comparative Example 1 was the same as that of Example 1.

Then, for Example 1 and Comparative Example 1, the illuminance distribution of light reaching (incident) the diffusion plate 12 was determined. The result is shown in FIG.

Referring to FIG. 10, it was found that in Example 1, the illuminance of light reaching (incident) the diffusion plate 12 can be made uniform compared to Comparative Example 1.

Specifically, in Example 1 and Comparative Example 1, the illuminance of light reaching the portion 12a of the diffusion plate 12 (the portion directly above the light guide bar (the periphery of the portion directly above)) 12a is increased. The illuminance of light reaching the portion (a portion directly above the middle between the adjacent light guide rods) 12b is low. Moreover, the illuminance of light reaching the portion 12a of Example 1 was lower than the illuminance of light reaching the portion 12a of Comparative Example 1. That is, in Example 1, the difference in illuminance between the light reaching the portion 12a and the light reaching the portion 12b was smaller than that in the comparative example 1.

Thereby, by forming the inclined surface 22g (the trapezoidal portion 22a) on the light guide bar 20, the uniformity of the illuminance of the light reaching the diffusion plate 12 can be improved, and the uniformity of the illumination light is improved. It was confirmed that it was possible.

Note that the light reaching the diffusion plate 12 is further uniformized by the diffusion plate 12 and the optical sheet 13.

(Second Embodiment)
In the second embodiment, a case where the light propagation part 121 of the light guide rod 120 has a rectangular cross section will be described with reference to FIG. 11, unlike the first embodiment.

In the backlight device according to the second embodiment of the present invention, the light guide bar 120 includes a light propagation part 121 and a light emission part 22 as shown in FIG.

In the second embodiment, the light propagation part 121 has a rectangular (square) cross section. The light propagating portion 121 includes a light incident surface 121c, a front surface (upper surface) 121d, a back surface (lower surface) 21e, a pair of side surfaces 121f, and an end surface 121g.

The light propagating portion 121 has a larger cross section (area) than the light emitting portion 22 as much as the end surface 121g when viewed from the front end surface 22c side of the light emitting portion 22.

As described above, in the second embodiment, the light propagation portion 121 is not provided with the inclined surface 21g.

The remaining structure and effects of the second embodiment are the same as those of the first embodiment.

(Third embodiment)
In the third embodiment, a case where a part of the light emitting portion 222 of the light guide bar 220 protrudes in the B direction will be described with reference to FIG. 12, unlike the first and second embodiments.

In the backlight device according to the third embodiment of the present invention, the light guide rod 220 includes a light propagation part 121 and a light emission part 222, as shown in FIG.

In the third embodiment, the light emitting part 222 includes a trapezoidal part 222a and a rectangular part 22b. The light emitting portion 222 includes a front end surface 222c, a front surface (upper surface) 222d, a back surface (lower surface) 22e, a pair of side surfaces 22f, and two inclined surfaces 222g. The trapezoidal portion 222a is an example of the “light deflecting portion” in the present invention.

And in 3rd Embodiment, the light-projection part 222 has a cross section (area) larger than the light propagation part 121 seeing from the front end surface 222c side. Specifically, the inclined surface 222g (the trapezoidal portion 222a) is formed so as to protrude outward in the B direction from the rectangular portion 22b and the light propagation portion 121. That is, the inclined surface 222 g (the trapezoidal portion 222 a) protrudes outward in the B direction from the light propagation unit 121 at the boundary portion between the light propagation unit 121 and the light emission unit 222.

The remaining structure of the third embodiment is the same as that of the first and second embodiments.

Unlike the second embodiment, the third embodiment differs from the second embodiment in that the trapezoidal portion 222a of the light emitting portion 222 is formed so as to protrude outward from the light propagating portion 121 as described above. It is possible to prevent light from being emitted to the outside from the surface of 121 on the light emitting part 222 side (the end surface 121 g of the second embodiment). Thereby, it can suppress that the utilization efficiency of light falls.

The remaining effects of the third embodiment are similar to those of the aforementioned first and second embodiments.

(Fourth embodiment)
In the fourth embodiment, with reference to FIG. 13, a case where the portion of the light guide bar 320 on the liquid crystal display panel 2 side is formed in a lens shape will be described, unlike the first to third embodiments.

In the backlight device 310 according to the fourth embodiment of the present invention, as shown in FIG. 13, the light emitting portion 322 of the light guide bar 320 is disposed on the liquid crystal display panel 2 side and formed in a lens shape (cylindrical lens shape). The lens portion 322a and the rectangular portion 22b are included. The light emitting portion 322 includes a front end surface 322c, a back surface (lower surface) 22e, a pair of side surfaces 22f, and a curved surface 322g. The backlight device 310 is an example of the “illumination device” in the present invention, and the lens unit 322a is an example of the “light deflection unit” in the present invention. The curved surface 322g is an example of the “inclined surface” in the present invention.

The curved surface 322g is inclined with respect to the arrangement direction (B direction) of the light guide bars 320 and the side surface 22f. And in 4th Embodiment, compared with the case where the light guide rod 20 in which the inclined surface 22g of the said 1st Embodiment was formed is formed by forming the curved surface 322g in the light guide rod 320, for example. The light emitted from the diffusion plate 12 does not easily reach the portion of the diffusion plate 12 directly above the light guide bar 320. That is, by forming the curved surface 322g on the light guide bar 320, the light emitted from the light guide bar 320 is deflected so that the traveling direction approaches the B direction. It becomes easy to reach the upper part between them.

The remaining structure of the fourth embodiment is the same as that of the first to third embodiments.

In the fourth embodiment, as described above, the lens portion 322a including the curved surface 322g is provided. Thereby, compared with the case where the trapezoid part 22a (inclined surface 22g) of the said 1st Embodiment is provided, for example, it can suppress more easily that the upper part of the adjacent light guide bar 320 becomes bright. it can. In addition, by forming the lens portion 322a with the curved surface 322g, it is possible to prevent the corner portion from being formed in the lens portion 322a. Thereby, it can suppress that the advancing direction of the light radiate | emitted from the lens part 322a changes discontinuously.

The remaining effects of the fourth embodiment are similar to those of the aforementioned first to third embodiments.

(Fifth embodiment)
In the fifth embodiment, referring to FIG. 14, unlike the first to fourth embodiments, a prism group 422a formed by a plurality of prisms 422b on the portion of the light guide bar 420 on the liquid crystal display panel 2 side. The case where is provided will be described.

In the backlight device 410 according to the fifth embodiment of the present invention, as shown in FIG. 14, the light emitting portion 422 of the light guide bar 420 includes a prism group 422a disposed on the liquid crystal display panel 2 side and a rectangular portion 22b. Including. The light emitting portion 422 includes a front end surface 422c, a back surface (lower surface) 22e, a pair of side surfaces 22f, and a plurality of prisms 422b. The backlight device 410 is an example of the “illumination device” in the present invention, and the prism group 422a is an example of the “light deflection unit” in the present invention.

In each of the plurality of prisms 422b, an inclined surface 422g inclined with respect to the arrangement direction (B direction) of the light guide rods 420 and the side surface 22f is formed.

Further, the prism group 422a may be formed in a linear Fresnel lens shape, for example.

In the fifth embodiment, the thickness (height) of the light guide bar 420 in the C direction is smaller than the thickness (height) of the light guide bar in the C direction in the first to fourth embodiments. Therefore, in the fifth embodiment, the distance from the diffusion plate 12 to the reflection sheet 11 is shorter than that in the first to fourth embodiments.

The remaining structure of the fifth embodiment is similar to that of the aforementioned first to fourth embodiments.

In the fifth embodiment, as described above, the light guide rod 420 is provided with the prism group 422a, and the prism group 422a is formed with the inclined surface 422g. Thereby, as in the fourth embodiment, for example, light emitted from the light guide rod 420 is out of the diffusion plate 12 as compared with the case where the trapezoidal portion 22a (inclined surface 22g) of the first embodiment is provided. It becomes easy to reach the portion directly above between the light guide bars 420 adjacent to each other. For this reason, it can suppress more easily that the upper part of the adjacent light guide bar 420 becomes bright. Further, by providing the prism group 422a on the light guide bar 420, the thickness (height) of the light guide bar 420 can be reduced, and thus the thickness of the backlight device 410 can be reduced.

The effects of the fifth embodiment are the same as those of the first to fourth embodiments.

(Sixth embodiment)
In the sixth embodiment, a case where the light guide bar group 550 is configured by a plurality of light guide bars 520 will be described with reference to FIGS. 15 and 16, unlike the first to fifth embodiments.

In the backlight device 510 according to the sixth embodiment of the present invention, as shown in FIGS. 15 and 16, a light guide bar group 550 is configured by a plurality of types (for example, six types) of light guide bars 520. A plurality of the light guide bar groups 550 are arranged along the B direction, and two light guide bar groups 550 are arranged along the A direction. The plurality of light guide bar groups 550 are arranged line-symmetrically in the A direction. The backlight device 510 is an example of the “illumination device” in the present invention. Moreover, the hatched area in FIGS. 15 and 16 shows a light emitting portion 522 to be described later of the light guide bar 520.

In the sixth embodiment, as shown in FIG. 16, a plurality of (for example, six) light guide bars 520 included in one light guide bar group 550 are formed to have different lengths. .

The light guide bar 520 includes a light propagation part 521 and a light emission part 522. The cross-sectional shapes of the light propagation part 521 and the light emission part 522 are formed in the same manner as the light propagation part and the light emission part in the first to fifth embodiments.

Also, the light propagation portions 521 of the plurality of light guide bars 520 included in one light guide bar group 550 have different lengths. On the other hand, the light emitting portions 522 of the plurality of light guide bars 520 included in one light guide bar group 550 have the same length.

Further, the plurality of light emitting units 522 are arranged one by one for each of a plurality of virtual divided regions obtained by dividing the display region of the liquid crystal display panel 2 in the A direction and the B direction. Note that a two-dot chain line in FIG. 16 indicates a virtual boundary line of the virtual divided region.

Further, the plurality of light emitting portions 522 are arranged in a substantially straight line in one light guide rod group 550. The direction in which the plurality of light emitting portions 522 are arranged in a substantially straight line is a direction intersecting (inclining) with respect to the direction (B direction) in which the light incident surfaces 521c of the light propagation portions 521 are arranged.

Further, the plurality of light sources 30 are attached to the mounting substrate 531. For example, one mounting substrate 531 is disposed on each side of the backlight device 510 in the A direction. Thereby, since the light source 30 which is a heat source can be disperse | distributed and arrange | positioned, the heat which generate | occur | produces in the light source 30 can be radiated easily. Moreover, since it can suppress that the light source 30 and its peripheral part become high temperature, it can suppress that the reliability of the light source 30 and other circuit components (not shown) falls.

The other structure of the sixth embodiment is the same as that of the first to fifth embodiments.

In the sixth embodiment, as described above, by providing the light guide bar group 550 with the plurality of light guide bars 520 having different lengths, the light source 30 is disposed on the edge of the backlight device 510, The light emitting portion 522 of the light guide bar 520 can be disposed at an arbitrary position of the backlight device 510. That is, an arbitrary number of light emitting portions 522 of the light guide bar 520 can be arranged in the A direction, and an arbitrary number can also be arranged in the B direction. Thereby, the backlight device 510 can be divided into an arbitrary number in both the A direction and the B direction, and the intensity of the illumination light can be controlled for each divided area (virtual divided area). As a result, high contrast and low power consumption of the display image can be further improved. Needless to say, moving picture display performance can be improved by controlling the intensity of illumination light in synchronization with the scanning of the liquid crystal display panel 2.

In the sixth embodiment, as described above, in one light guide rod group 550, the plurality of light emitting portions 522 are arranged in a substantially straight line. Accordingly, when the plurality of light guide rod groups 550 are arranged side by side, the plurality of light emitting portions 522 can be easily arranged uniformly in the backlight device 510.

Other effects of the sixth embodiment are the same as those of the first to fifth embodiments.

It should be noted that the embodiments and examples disclosed this time are examples in all respects and are not restrictive. The scope of the present invention is shown not by the above description of the embodiments and examples but by the scope of claims, and further includes meanings equivalent to the scope of claims and all modifications within the scope.

For example, in the above-described embodiment, an example in which the display panel and the display device are applied to the liquid crystal display panel and the liquid crystal display device, respectively, has been described. You may apply to a panel and a display apparatus.

In the above-described embodiment, an example in which the lighting device is applied to a backlight device has been described. However, the present invention is not limited thereto, and can be applied to lighting devices other than the backlight device, such as an indoor lighting device. is there.

Moreover, although the said embodiment demonstrated the example which comprised the light source so that white light could be obtained, this invention is not restricted to this, You may comprise a light source so that light other than white light may be obtained. Good.

Further, unlike the above embodiment, the light guide rod may be formed in a tapered shape (tapered shape). Specifically, for example, a pair of side surfaces 622f of the light guide rod 620 (light emitting portion 622) like the backlight device (illumination device) 610 according to the first modification of the present invention shown in FIGS. 17 to 19 may be formed so as to be inclined with respect to the A direction so that the distance from each other decreases as the distance from the light propagation portion 621 increases. At this time, as shown in FIG. 19, the trapezoidal portion 622a is formed so that the thickness (length in the C direction) decreases toward the distal end surface 622c, and the rectangular portion 622b is directed toward the distal end surface 622c. And may be formed to have a certain thickness. In addition, the hatching area | region of FIG. 19 has shown the process part.

If configured as described above, as shown in FIG. 20, the probability that the light from the light source 30 will reach the processed portion of the light emitting portion 622 will increase, and the probability that it will reach the tip surface 622c will decrease. Thereby, since it can suppress that light radiate | emits from the front end surface 622c of the light-guide rod 622, the utilization efficiency of light can be improved. Needless to say, the light guide rods of the fourth and fifth embodiments may be formed in a tapered shape.

Moreover, although the said embodiment demonstrated the example which has arrange | positioned the light guide rod in multiple numbers (three or more) along the B direction, this invention is not restricted to this, For example, it is 2nd of this invention shown in FIG. As in the backlight device according to the modification, a plurality (three or more) of light guide bars 720 may be arranged along the short side direction (A direction) of the liquid crystal display panel. If comprised in this way, the light source 30 can be intermittently lighted sequentially in the A direction in synchronization with scanning of a general liquid crystal display panel, and the moving image display performance of the liquid crystal display device can be further improved.

Moreover, in the said 6th Embodiment, although shown about the example which has arrange | positioned the light-emitting part 522 of the some light guide bar | burr 520 to the direction which cross | intersects (inclines) with respect to B direction, this invention is not limited to this. First, like the backlight device (illumination device) 810 according to the third modification of the present invention shown in FIGS. 22 and 23, the light emitting portions 822 of the plurality of light guide bars 820 are perpendicular to the B direction ( (Parallel to the A direction) may be arranged in a straight line. In this case, as shown in FIG. 23, the light guide rod 820 is disposed so as to extend in a direction (D direction) inclined with respect to the A direction and the B direction. Note that the plurality of light guide rod groups 850 may be arranged point-symmetrically with respect to the center of the backlight device 810 as shown in FIG.

In the above-described embodiment, an example in which a plurality of light guide bars are provided separately has been described. A connecting portion 921 may be provided between the light rods 920, and a plurality of light guide rods 920 may be integrally formed. If comprised in this way, position alignment with the light guide rod 920 and the light source 30 can be performed easily, and the assembly workability | operativity of a backlight apparatus can be improved.

In the sixth embodiment, the plurality of light guide rods included in one light guide rod group include a light propagation portion having a different length and a light emitting portion having the same length. Although the example which comprised was demonstrated, this invention is not restricted to this, The several light guide rod contained in one light guide rod group is the light propagation part which has mutually different length, and the light which has mutually different length. And an output part.

1 Liquid crystal display device (display device)
2 Liquid crystal display panel (illuminated member)
10, 310, 410, 510, 610, 810 Backlight device (lighting device)
11 Reflective sheet (reflective member)
12 Diffuser (Optical member)
13 Optical sheet (optical member)
20, 120, 220, 320, 420, 520, 620, 720, 820, 920

Light guide rod

21, 121, 521, 621

Light propagation part

22, 222, 322, 422, 522, 622, 822

Light emission part

22a, 222a, 622a trapezoidal part (light deflection part)
22b, 622b

Rectangular portion

22f, 622f

Side surface

22g, 222g, 422g Inclined surface 22h Processing portion (processing portion for light emission)
30 Light source 322a Lens part (light deflection part)
322g Curved surface (inclined surface)
422a Prism group (light deflection unit)
550, 850 Light guide bar group

Claims

A lighting device arranged on the back side of the illuminated member,
Multiple light sources;
A plurality of light guide rods that receive light from the light source and guide light from the light source;
The plurality of light guide bars are arranged at a predetermined interval from each other,
The light guide rod is provided in a region different from the light emitting processing unit for changing the traveling direction of light from the light source to a direction suitable for external emission, and the light emitting processing unit, A light deflecting unit that deflects light from the processing unit and emits the light to the outside,
The illumination device according to claim 1, wherein the light deflection unit includes an inclined surface that is inclined with respect to a surface on which the light emitting processing unit is formed.
The illumination device according to claim 1, wherein the light deflection unit is formed closer to the illuminated member than the light emitting processing unit.
The lighting device according to claim 1, wherein the light emitting processing portion is formed in a portion of the light guide bar opposite to the illuminated member side.
The light guide bar includes a side surface that intersects an arrangement direction of the plurality of light guide bars,
The lighting device according to any one of claims 1 to 3, wherein the light emitting processing portion is formed on the side surface.
The lighting device according to claim 4, wherein the side surface is substantially orthogonal to an arrangement direction of the plurality of light guide bars.
The illumination device according to any one of claims 1 to 5, wherein the inclined surface includes a curved surface.
The light deflection unit includes a prism group,
The illumination device according to any one of claims 1 to 5, wherein the inclined surface is formed in the prism group.
The lighting device according to any one of claims 1 to 7, wherein the inclined surface is inclined with respect to an arrangement direction of the plurality of light guide bars.
The light guide rod includes a light propagation portion disposed on the light source side and having a function of propagating light, and a light emission portion on which the light emission processing portion and the light deflection portion are formed. The lighting device according to any one of claims 1 to 8.
The lighting device according to claim 9, wherein the light deflection unit is not provided in the light propagation unit, but is provided in the light emission unit.
The light deflecting portion of the light emitting portion is formed so as to protrude outward from the light propagating portion at a boundary portion between the light propagating portion and the light emitting portion. The lighting device according to 10.
An optical member disposed on the illuminated member side of the light guide rod;
A reflection member disposed on the opposite side of the light guide rod from the illuminated member;
The lighting device according to any one of claims 1 to 11, wherein a distance from the light guide bar to the optical member is larger than a distance from the light guide bar to the reflection member.
The light guide rod includes a rectangular part having a rectangular cross section, and a trapezoidal part having a trapezoidal cross section,
The light emitting processing part is formed in the rectangular part,
The lighting device according to any one of claims 1 to 12, wherein the light deflection section is formed in the trapezoidal section.
The plurality of light guide bars constitute one or more light guide bar groups,
The lighting device according to any one of claims 1 to 13, wherein one light guide bar group includes a plurality of light guide bars having different lengths.
The light guide rod is disposed on the light source side, and includes a light propagation part having a function of propagating light, and a light emission part in which the light emission processing part and the light deflection part are formed,
The lighting device according to claim 14, wherein in the one light guide rod group, the plurality of light emitting portions are arranged substantially in a straight line.
The light guide rod is disposed on the light source side, and includes a light propagation part having a function of propagating light, and a light emission part in which the light emission processing part and the light deflection part are formed,
The lighting device according to claim 14, wherein the plurality of light guide bars having different lengths include the light propagation portions having different lengths.
The lighting device according to any one of claims 1 to 16,
A display device comprising: an illuminated member illuminated by the illumination device.