CN222280866U - Lens array and display device - Google Patents

Abstract

The utility model provides a lens array capable of singly inclining an optical axis of emitted light to an optical axis of incident light and a display device having the lens array. The lens array is composed of a plurality of lenses (61) having first surfaces (61 a) and second surfaces (61B) facing in opposite directions along a reference plane (B). In a lens (61), at least either one of a first surface (61 a) and a second surface (61B) is inclined to a reference plane (B). When an axis perpendicular to the reference plane (B) is used as a reference axis (A), light which advances in a lens (61) in parallel with the reference axis (A) and enters the center (C1) of the first surface (61 a) is emitted from the second surface (61B) in a manner of inclining to the reference axis (A). The display device includes, in addition to the lens array, a parallel light emitting unit that emits light that advances parallel to the reference axis (a), and a display unit that displays information by being illuminated with light that has passed through the lens array.

Description

Lens array and display device

Technical Field

The utility model relates to a lens array and a display device with the lens array.

Background

For example, patent document 1 describes a lens array in which a plurality of lenses having convex surfaces are arranged for use in a display device. In this lens array, the optical axis of light entering a lens is aligned with the optical axis of light exiting the lens (see light rays passing through the center of the lens in fig. 4 of patent document 1).

Prior art literature

Patent literature

Patent document 1 Japanese patent application laid-open No. 2019-82722

Disclosure of utility model

Problems to be solved by the utility model

In the lens array unit of patent document 1, the optical axis of the emitted light cannot be inclined to the optical axis of the incident light. Therefore, when it is desired to tilt the optical axis of the light emitted from the lens array, optical components such as a prism sheet and a prism lens are required in addition to the lens array.

In view of the above, an object of the present utility model is to provide a lens array capable of individually tilting an optical axis of outgoing light to an optical axis of incoming light, and a display device having the lens array.

Means for solving the problems

In order to achieve the above object, in a lens array according to a first aspect of the present utility model,

Is composed of a plurality of lenses which are arranged along a reference plane and are provided with a first surface and a second surface facing opposite directions,

In the one lens, at least either one of the first face and the second face is inclined to the reference plane,

When an axis perpendicular to the reference plane is used as a reference axis, light advancing in parallel with the reference axis and entering the center of the first surface is emitted from the second surface in a manner inclined to the reference axis in the lens.

In order to achieve the above object, a display device according to a second aspect of the present utility model includes:

the lens array;

A parallel light emitting unit which emits light advancing parallel to the reference axis toward the lens array, and

And a display unit which is emitted from the parallel light emitting unit, and displays information by being illuminated with light passing through the lens array.

Effects of the utility model

According to the present utility model, it is possible to provide a lens array capable of individually tilting an optical axis of outgoing light to an optical axis of incoming light, and a display device having the lens array.

Brief description of the drawings

Fig. 1 is a diagram showing a mode in which a display device according to an embodiment of the present utility model is mounted on a vehicle.

Fig. 2 is a diagram showing a structure of the display device according to this embodiment.

Fig. 3 is a view of a portion corresponding to one lens in the lens array according to the embodiment, as seen from the second surface side.

Fig. 4 is a diagram for explaining the slopes of the first surface and the second surface in a lens according to this embodiment.

Fig. 5 is a perspective view of a part of the lens array according to the embodiment from the first surface side.

Fig. 6 is a perspective view of a part of the lens array according to the embodiment from the second surface side.

Fig. 7 is a diagram showing a structure of a display device according to a comparative example.

Fig. 8 is a diagram showing a manner in which the display device according to the modification is mounted on the vehicle.

Symbol description

100:1:2:Dash panel, 3:3:3:3 a line of sight, 10:10:11:display surface, 20:backlight unit, 30:housing, 40:parallel light emission part, 41:circuit substrate, 42:light source, 43:condensing lens, 50:diffuser plate, 60:lens array, A:reference axis, B:reference plane, 61:61 a first surface, C1:center, P1:first tangential plane, N1:first normal line, 61 b:second surface, C2:center, P2:second tangential plane, N2:second normal line, L1:incident light, L2:outgoing light, lref:refracted light, 100 P:display device according to comparative example, 20 P:backlight unit, 60 P:lens array, 70P prism lens, 200:display device according to modification example, 4:windshield, V:virtual image.

Detailed Description

An embodiment of the present utility model will be described with reference to the accompanying drawings.

As shown in fig. 1, a display device 100 according to the present embodiment is provided on a dash panel 2 of a vehicle 1, and displays various pieces of information (hereinafter, referred to as vehicle information) related to the vehicle 1 to a user 3. The vehicle information may include external information of the vehicle 1, such as information on the surroundings of the vehicle 1, as well as information on the vehicle 1 itself.

As shown in fig. 2, the display device 100 includes a display unit 10, a backlight unit 20 for illuminating the display unit 10 from behind, and a housing 30. The housing 30 accommodates the display section 10 and the backlight unit 20. The case 30 is provided with a portion (not shown) that transmits or transmits light representing the image displayed on the display unit 10 to the user 3.

The display unit 10 is illuminated by a backlight unit 20, and displays vehicle information on a display surface 11. The display surface 11 is a surface facing the user 3 in the display unit 10. The display unit 10 is constituted by a liquid crystal panel, for example. In this embodiment, the display surface 11 has a rectangular shape that is laterally long when viewed from the user 3. The liquid crystal panel transmits light with appropriate pixels, and thereby displays an image representing vehicle information on the display surface 11. The display unit 10 is not limited to a liquid crystal panel as long as it can display information by being illuminated by the backlight unit 20, and may be a printed board or the like on which icons for displaying warnings or the like are printed.

The backlight unit 20 has a parallel light emitting portion 40, a diffusion plate 50, and a lens array 60.

The parallel light emitting unit 40 emits light that advances parallel to the reference axis a toward the lens array 60. The reference axis a is, for example, a virtual straight line parallel to the normal line of the display surface 11. The parallel light emitting unit 40 includes a circuit board 41, a light source 42 mounted on the circuit board 41, and a condenser lens 43.

The light source 42 is constituted by a light emitting element such as an LED (LIGHT EMITTING Diode), and a plurality of light emitting elements are provided on the circuit board 41. The condensing lens 43 condenses light emitted from the light source 42 and makes it parallel to the reference axis a. The condenser lens 43 has a plurality of convex lenses corresponding to the plurality of light sources 42, respectively.

The diffusion plate 50 diffuses light emitted from the parallel light emitting portion 40 and transmitted through the lens array 60. Thus, the display section 10 is backlit by the light diffused by the diffusion plate 50. The diffusion plate 50 has a known structure for imparting a diffusion function to a substrate made of polyethylene terephthalate, polycarbonate, acrylic or the like. The diffusion function is realized by, for example, microbeads coated on the surface of a substrate, fine shapes formed on the surface of the substrate, a diffusion material compounded with the substrate, and the like.

The lens array 60 is, for example, a microlens array, and is composed of a plurality of lenses 61 arranged along the reference plane B. The reference plane B is a virtual plane whose normal is parallel to the reference axis a. The arrangement and pitch of the lenses 61 in the lens array 60 are optimized in such a manner that the longitudinal and lateral directions correspond to the longitudinal and lateral directions of the display surface 11, and the display surface 11 having a rectangular shape long in the lateral direction is uniformly illuminated.

A lens 61 has a first surface 61a and a second surface 61b facing opposite directions to each other. The first surface 61a faces the parallel light emitting portion 40, and the second surface 61b faces the diffusion plate 50. That is, in the one lens 61, the light emitted from the parallel light emitting unit 40 is incident on the first surface 61a and then emitted from the second surface 61b.

Fig. 3 is a view of a portion of the lens array 60 corresponding to one lens 61 from the normal direction of the reference plane B, and from the second surface 61B side. The lateral direction Dh in the drawing corresponds to the lateral direction of the display surface 11 set to be a rectangle long in the lateral direction, and the longitudinal direction Dv corresponds to the longitudinal direction of the display surface. As shown in fig. 3, the second surface 61B of the present embodiment has a shape in which the convex curved surface of the plano-convex lens is inclined to the reference plane B. In addition, a portion of the lens 61 according to the present embodiment shown in fig. 3, through which the C-C line passes, is raised from one end and the other end in the lateral direction Dh of the portion. In fig. 2, a cross-sectional view taken along the lateral direction Dh of the display device 100 is schematically shown with hatching showing the cross-section omitted in consideration of the ease of viewing the drawing. That is, the normal direction of the paper surface in fig. 2 corresponds to the lateral direction Dh, and the vertical direction Dv in fig. 2 corresponds to the vertical direction Dv.

Fig. 4 is a diagram for explaining the slopes of the first surface 61a and the second surface 61b in the lens 61. In fig. 4, a portion corresponding to a cross section in the case where a lens 61 is cut by a line C-C shown in fig. 3 is schematically shown. The second face 61b shown in fig. 4 merely represents the shape of a portion along the C-C line shown in fig. 3, and does not represent that the second face 61b is planar. The first surface 61a is, for example, a convex curved surface.

As shown in fig. 4, in this embodiment, both the first surface 61a and the second surface 61B of the lens 61 are inclined to the reference plane B. Here, a plane tangential to the first surface 61a on the center C1 (center point) of the first surface 61a is taken as a first tangential plane P1. In addition, a plane tangential to the second surface 61b on the center C2 (center point) of the second surface 61b is taken as a second tangential plane P2. When so defined, specifically, the first face 61a being inclined to the reference plane B means that the first tangential plane P1 is inclined to the reference plane B. Likewise, the second face 61B being inclined to the reference plane B means that the second tangential plane P2 is inclined to the reference plane B.

The first tangential plane P1 is inclined in the counterclockwise direction in fig. 4 with respect to the reference plane B. When the normal line of the first tangential plane P1 is the first normal line N1, the inclination angle δ of the first normal line N1 with respect to the reference axis a is equal to the inclination angle of the first tangential plane P1 with respect to the reference plane B. The second tangential plane P2 is inclined with respect to the reference plane B in a clockwise direction in fig. 4. When the normal line of the second tangential plane P2 is taken as the second normal line N2, the inclination angle δ of the second normal line N2 with respect to the reference axis a is equal to the inclination angle of the second tangential plane P2 with respect to the reference plane B. In this way, in one lens 61, the first surface 61a and the second surface 61B are inclined in mutually opposite directions with respect to the reference plane B.

Here, in the one lens 61, a light ray that advances in parallel with the reference axis a and enters the center C1 of the first surface 61a is taken as an incident light ray L1. In addition, the incident light L1 is refracted by the first surface 61a, and then, the light advancing through a lens 61 is used as the refracted light Lref. The light emitted from the second surface 61b is the light emitted from the second surface 61b, which is refracted by the second surface 61 b. In the description using fig. 4, the reference axis a passes through the center C1 of the first surface 61 a.

In the lens 61 of the present embodiment, the center C2 of the second surface 61b is not the intersection point D of the reference axis a and the second surface 61b, but a point at which the refracted light ray Lref reaches the second surface 61 b. Therefore, the outgoing light L2 is emitted from the center C2 of the second surface 61 b.

Here, the inclination angle of the refractive light ray Lref with respect to the reference axis a is defined as Φ, the distance from the center C1 to the center C2 in the direction parallel to the reference axis a is defined as T, and the distance from the reference axis a to the center C2 in the direction perpendicular to the reference axis a is defined as S. Then, using a trigonometric function, S is expressed as shown in the following equation (1).

S=T·tanφ...(1)

When the absolute refractive index ratio of the material of one lens 61 (that is, the material of the lens array 60) and air is set to be the refractive index n, sin δ/sin (δ - Φ) =n is established according to snell's law, and when this expression is expanded, Φ is expressed as shown in the following expression (2).

φ=δ-arcsin(sinδ/n)...(2)

As can be seen from equations (1) and (2), the distance S from the reference axis a to the center C2 of the second surface 61b is defined by n, δ, and T. The inclination angle θ of the outgoing light ray L2 with respect to the reference axis a can be derived from the relationship θ=arcsin (n·sin (δ+Φ)) - δ.

As described above, the lens array 60 in which the lenses 61 having the plurality of first surfaces 61a and the plurality of second surfaces 61B are arranged with both inclined to the reference plane B has a unique shape in which the lenses 61 are arranged in a tile shape, as shown in fig. 5 and 6. Fig. 5 is a perspective view of a part of the lens array 60 from the first surface 61a side, and fig. 6 is a perspective view of a part of the lens array 60 from the second surface 61b side.

As shown in fig. 2, the lens array 60 of the present embodiment is configured such that the emitted light L2 is inclined upward from the normal line of the display surface 11, and is set along the line of sight 3a of the user 3. This allows light representing the image displayed on the display unit 10 to be efficiently transmitted to the user 3. Fig. 2 schematically shows the optical path of the light beam entering the center C1 of the first surface 61a and the light beam emitted as a result thereof, which is advanced in parallel with the reference axis a in any lens 61. In this figure, light incident on a region other than the center C1 of the first surface 61a is omitted in view of ease of viewing the drawing, but the light distribution of one lens 61 is set to be wider in the lateral direction than in the longitudinal direction corresponding to the rectangular display surface 11 which is long in the lateral direction. Next, the optical paths of fig. 7 for comparison are also represented in the same manner.

Fig. 7 shows a display device 100P according to a comparative example. The backlight unit 20P of the display device 100P includes a prism lens 70P in addition to the parallel light emitting unit 40, the diffusion plate 50, and the conventional lens array 60P. Note that the same reference numerals as those of the above embodiments are used for the same structures as those of the above embodiments, and descriptions thereof are omitted.

In the conventional lens array 60P, the incident light L1 and the outgoing light L2 are kept parallel to the reference axis a. Therefore, as in the display device 100 of the above embodiment, when it is desired that the optical axis of the light emitted from the display surface 11 is inclined upward along the line of sight 3a of the user 3, it is necessary to add an optical member such as the prism lens 70P between the lens array 60P and the diffusion plate 50.

On the other hand, the lens array 60 of the present embodiment can individually tilt the optical axis of the light emitted from one lens 61 to the optical axis of the light incident on the one lens 61. Therefore, according to the lens array 60, it is not necessary to provide additional optical components as in the comparative example when the backlight unit 20 or the display device 100 is configured, and the number of components can be reduced.

(Modification)

In the above embodiment, the display device 100 is shown in which the user 3 directly visually observes the image displayed on the display surface 11, but the display device having the lens array 60 is not limited to this embodiment. As shown in fig. 8, the lens array 60 may be provided in a display device configured as a head-up display device. The display device 200 is provided in the dash panel 2, for example, and emits light representing an image to the windshield 4 of the vehicle 1. The user 3 is able to visually observe the virtual image V of the image by the light reflected by the windscreen 4. The display device 200 includes one or more mirrors for directing light representing an image displayed on the display unit 10 to the windshield 4, in addition to the display unit 10, the backlight unit 20, and the housing 30, which are similar to those of the above-described embodiments. The mirror comprises a concave mirror.

In this display device 200, the lens array 60 may be used to determine the tilt angle θ so that the light reflected by the windshield 4 is along the line of sight of the user 3. This allows light representing the image displayed on the display unit 10 to be efficiently transmitted to the user 3.

The present utility model is not limited to the above embodiments, modifications, and drawings. Changes (including deletion of constituent elements) can be appropriately performed within a range that does not change the gist of the present utility model.

In the above description, an example in which both the first surface 61a and the second surface 61B are inclined to the reference plane B is shown. However, in the one lens 61, as long as a condition (hereinafter, referred to as a basic condition) is satisfied that light that advances in parallel with the reference axis a and enters the center C1 of the first surface 61a is emitted from the second surface 61B so as to be inclined to the reference axis a, at least either one of the first surface 61a and the second surface 61B may be inclined to the reference plane B. In the above description, the first surface 61a and the second surface 61B have the same inclination angle "δ" with respect to the reference plane B, but the inclination angles may be different.

In addition, as long as the basic conditions are satisfied, the respective shapes of the first surface 61a and the second surface 61b in the one lens 61 may be made arbitrary, and may be changed according to purposes, such as a convex curved surface, a concave curved surface, a spherical surface, an annular surface, a planar surface, and the like. The centers C1 and C2 may be defined as follows, regardless of the shapes of the first surface 61a and the second surface 61 b. The center of the first surface 61a means the same position as the drawing when an optical center point (reference point) in the case where the first surface 61a is not inclined to the reference plane B is drawn on the first surface 61 a. Similarly, the center of the second surface 61B means the same position as the drawing when an optical center point (reference point) in the case where the second surface 61B is not inclined to the reference plane B is drawn on the second surface 61B.

In the above description, descriptions of well-known technical matters are omitted as appropriate for easy understanding of the present utility model.

The present utility model is capable of various embodiments and modifications without departing from the broad spirit and scope of the utility model. The above-described embodiments are intended to illustrate the present utility model, and do not limit the scope of the present utility model. That is, the scope of the present utility model is not expressed by the embodiments but by the claims. Further, various modifications performed within the scope of the claims and the scope of the meaning of the utility model equivalent thereto are regarded as being within the scope of the present utility model.

Claims (4)

1. A lens array comprising a plurality of lenses having first and second surfaces facing in opposite directions along a reference plane,

In the one lens, at least either one of the first face and the second face is inclined to the reference plane,

When an axis perpendicular to the reference plane is used as a reference axis, light advancing in parallel with the reference axis and entering the center of the first surface is emitted from the second surface in a manner inclined to the reference axis in the lens.

2. The lens array of claim 1, wherein the lens array is configured to,

The first face is inclined to the reference plane,

In the one lens, the center of the second surface is a point at which light, which is incident on the center of the first surface and refracted by the center of the second surface, reaches the second surface, and proceeds parallel to the reference axis.

3. A lens array according to claim 1 or 2, wherein,

The first face and the second face are inclined toward opposite directions to each other with respect to the reference plane.

4. A display device, comprising:

The lens array of claim 1 or 2;

A parallel light emitting unit which emits light advancing parallel to the reference axis toward the lens array, and

And a display unit which is emitted from the parallel light emitting unit, and displays information by being illuminated with light passing through the lens array.