Lens array and display device
By designing an inclined lens surface, light in the lens array is emitted at an inclined angle, which solves the problem that the single-body tilts the optical axis in the prior art, reduces the number of parts, and improves the simplicity of the optical device.
Patent Information
- Application Number
- CN202322820172.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2022-10-25
- Filing Date
- 2023-10-19
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2033-10-19
AI Technical Summary
The existing lens arrays cannot monolithically incline the optical axis of the emitted light to the optical axis of the incoming light, resulting in the need of additional optical components such as prism sheets or prism lenses in the event of tilting the optical axis.
A lens array is designed, wherein the first and second surfaces of the lens are inclined to the reference plane, and after light enters the first surface in a parallel to the reference axis, it emits from the second surface at an inclination angle to achieve tilt of the optical axis.
The optical axis of the emitted light is achieved by tilting the optical axis of the emitted light monolithically to the optical axis of the incoming light, reducing the number of components and avoiding the use of additional optical components.
Smart Images
Figure CN222280866U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a lens array and a display device having the lens array. Background Art
[0002] For example, Patent Document 1 describes a lens array for a display device, which is composed of a plurality of lenses with convex surfaces arranged on both sides. In this lens array, the optical axis of light incident on one lens is consistent with the optical axis of light emitted from the one lens (see Patent Document 1). Figure 4 light passing through the center of a lens).
[0003] Prior art literature
[0004] Patent Literature
[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-82722 Utility Model Content
[0006] Issues to be solved by utility models
[0007] The lens array alone of Patent Document 1 cannot tilt the optical axis of the emitted light relative 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.
[0008] In view of the above situation, the present invention aims to provide a lens array capable of tilting the optical axis of emitted light relative to the optical axis of incident light by itself, and a display device having the lens array.
[0009] Means for solving problems
[0010] In order to achieve the above-mentioned object, in the lens array involved in the first aspect of the present invention,
[0011] The lens is composed of a plurality of lenses having first surfaces and second surfaces facing opposite directions arranged along a reference plane, wherein:
[0012] In the lens, at least one of the first surface and the second surface is inclined with respect to the reference plane.
[0013] When an axis perpendicular to the reference plane is taken as a reference axis, in the one lens, light that advances in parallel with the reference axis and enters the center of the first surface is emitted from the second surface in a manner inclined with respect to the reference axis.
[0014] In order to achieve the above-mentioned object, the display device according to the second aspect of the present invention has:
[0015] the lens array;
[0016] a parallel light emitting unit configured to emit light in parallel with the reference axis toward the lens array; and
[0017] The display unit is illuminated by the light emitted from the parallel light emitting unit and passing through the lens array to display information.
[0018] Utility Model Effect
[0019] According to the present invention, it is possible to provide a lens array capable of tilting the optical axis of emitted light relative to the optical axis of incident light by itself, and a display device having the lens array.
[0020] Brief description of the attached figure
[0021] Figure 1 This is a diagram showing a mode in which a display device according to an embodiment of the present invention is mounted on a vehicle.
[0022] Figure 2 It is a diagram showing the structure of a display device involved in this embodiment.
[0023] Figure 3 This is a diagram of a portion corresponding to one lens in the lens array according to the embodiment as viewed from the second surface side.
[0024] Figure 4 It is a diagram for explaining the slopes of the first surface and the second surface of a lens according to the embodiment.
[0025] Figure 5 This is a perspective view of a part of the lens array according to this embodiment as viewed from the first surface side.
[0026] Figure 6 This is a perspective view of a part of the lens array according to this embodiment as viewed from the second surface side.
[0027] Figure 7 It is a diagram showing the structure of a display device according to a comparative example.
[0028] Figure 8 It is a diagram showing a mode in which a display device according to a modification example is mounted on a vehicle.
[0029] Explanation of symbols
[0030] 100: display device; 1: vehicle; 2: front panel; 3: user; 3a: line of sight; 10: display unit; 11: display surface; 20: backlight unit; 30: housing; 40: parallel light emitting unit; 41: circuit substrate; 42: light source; 43: focusing lens; 50: diffuser; 60: lens array; A: reference axis; B: reference plane; 61: lens; 61a: first surface; C1: center; P1: first tangent plane; N1: first normal; 61b: second surface; C2: center; P2: second tangent plane; N2: second normal; L1: incident light; L2: emitted light; Lref: refracted light; 100P: display device involved in the comparative example; 20P: backlight unit; 60P: lens array; 70P: prism lens; 200: display device involved in the modified example; 4: windshield; V: virtual image. DETAILED DESCRIPTION
[0031] An embodiment of the present invention will be described with reference to the accompanying drawings.
[0032] The display device 100 according to this embodiment is as follows Figure 1 As shown, it is provided on the dash panel 2 of the vehicle 1 and displays various information about the vehicle 1 (hereinafter referred to as vehicle information) to the user 3. The vehicle information includes not only the information of the vehicle 1 itself but also external information of the vehicle 1 such as information around the vehicle 1.
[0033] The display device 100 is as follows Figure 2 As shown, the display unit 10, a backlight unit 20 for illuminating the display unit 10 from behind, and a housing 30 are provided. The housing 30 accommodates the display unit 10 and the backlight unit 20. The housing 30 is provided with a portion (not shown) that allows light representing an image displayed by the display unit 10 to pass or transmit toward the user 3.
[0034] The display unit 10 is illuminated by the backlight unit 20, and displays vehicle information on the display surface 11. The display surface 11 is the surface of the display unit 10 facing the user 3. The display unit 10 is composed of, for example, a liquid crystal panel. In this embodiment, the display surface 11 is a horizontally long rectangle when viewed from the user 3. The liquid crystal panel displays an image representing vehicle information on the display surface 11 by transmitting light with appropriate pixels. In addition, as long as the display unit 10 is configured to be illuminated by the backlight unit 20 and display information, it is not limited to a liquid crystal panel, and may also be a printed board printed with icons for displaying warnings, etc.
[0035] The backlight unit 20 includes a parallel light emitting portion 40 , a diffusion plate 50 , and a lens array 60 .
[0036] The parallel light emitting unit 40 emits light 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.
[0037] The light source 42 is composed of a light emitting element such as an LED (Light Emitting Diode), and a plurality of them are provided on the circuit board 41 . The condenser lens 43 condenses the 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 .
[0038] The diffuser 50 diffuses the light emitted from the parallel light emitting unit 40 and transmitted through the lens array 60. In this way, the display unit 10 is illuminated from behind by the light diffused by the diffuser 50. The diffuser 50 is a well-known structure in which a diffusion function is imparted to a substrate formed of polyethylene terephthalate, polycarbonate, acrylic acid, etc. The diffusion function is achieved, for example, by micro beads coated on the surface of the substrate, fine shapes formed on the surface of the substrate, and a diffusion material mixed with the substrate.
[0039] The lens array 60 is, for example, a micro lens array, and is composed of a plurality of lenses 61 arranged along a reference plane B. The reference plane B is a virtual plane whose normal is parallel to the reference axis A. The arrangement and spacing of the lenses 61 in the lens array 60 are optimized so that the longitudinal and lateral directions correspond to the longitudinal and lateral directions of the display surface 11, and the transversely long rectangular display surface 11 is uniformly illuminated.
[0040] The lens 61 has a first surface 61a and a second surface 61b facing opposite directions. The first surface 61a faces the parallel light emitting unit 40, and the second surface 61b faces the diffuser 50. That is, in the lens 61, light emitted from the parallel light emitting unit 40 enters the first surface 61a and is then emitted from the second surface 61b.
[0041] Figure 3 This is a diagram of a portion of the lens array 60 corresponding to one lens 61 observed from the normal direction of the reference plane B, and is a diagram observed from the second surface 61b side. In addition, the horizontal direction Dh in the figure corresponds to the horizontal direction of the display surface 11 set as a horizontally long rectangle as described above, and the vertical direction Dv corresponds to the vertical direction of the display surface. Figure 3 As shown, the second surface 61b of this embodiment has a shape such that the convex surface of the plano-convex lens is inclined to the reference plane B. Figure 3 The portion corresponding to the lens 61 involved in the present embodiment shown in FIG. 1 is convexerted at one end and the other end of the portion in the lateral direction Dh. Figure 2In the cross-sectional view observed along the horizontal direction Dh of the display device 100, the hatching indicating the cross section is omitted for the sake of the easy viewing of the drawing, and the cross-sectional view is schematically indicated. That is, Figure 2 The normal direction of the paper is equivalent to the horizontal direction Dh. Figure 2 The up and down direction is equivalent to the longitudinal direction Dv.
[0042] Figure 4 is a diagram for explaining the slopes of the first surface 61a and the second surface 61b of a lens 61. Figure 4 In the figure, it is shown schematically that Figure 3 The CC line shown is a portion of a cross section of a lens 61 cut through. Figure 4 The second surface 61b shown only represents the Figure 3 The shape of the CC line portion shown does not mean that the second surface 61b is a flat surface. The first surface 61a is, for example, a convex curved surface.
[0043] like Figure 4 As shown, in this embodiment, both the first surface 61a and the second surface 61b in a lens 61 are inclined to the reference plane B. Here, the plane tangent to the first surface 61a at the center C1 (center point) of the first surface 61a is referred to as the first tangent plane P1. In addition, the plane tangent to the second surface 61b at the center C2 (center point) of the second surface 61b is referred to as the second tangent plane P2. When defined in this way, specifically, the first surface 61a is inclined to the reference plane B means that the first tangent plane P1 is inclined to the reference plane B. Similarly, the second surface 61b is inclined to the reference plane B means that the second tangent plane P2 is inclined to the reference plane B.
[0044] The first tangent plane P1 is relative to the reference plane B Figure 4 When the normal line of the first tangent plane P1 is taken as the first normal line N1, the inclination angle δ of the first normal line N1 relative to the reference axis A is equal to the inclination angle of the first tangent plane P1 relative to the reference plane B. The second tangent plane P2 is inclined in the counterclockwise direction relative to the reference plane B. Figure 4 When the normal line of the second tangent plane P2 is taken as the second normal line N2, the inclination angle δ of the second normal line N2 relative to the reference axis A is equal to the inclination angle of the second tangent plane P2 relative to the reference plane B. In this way, in a lens 61, the first surface 61a and the second surface 61b are inclined in opposite directions relative to the reference plane B.
[0045] Here, in the lens 61, the light that advances in a manner parallel to the reference axis A and enters the center C1 of the first surface 61a is referred to as the incident light L1. In addition, the light that advances in the lens 61 after being refracted by the first surface 61a is referred to as the refracted light Lref. In addition, the refracted light Lref is refracted by the second surface 61b, and the light that is emitted from the second surface 61b is referred to as the emitted light L2. Figure 4 In the description of FIG. 6 , the reference axis A passes through the center C1 of the first surface 61 a .
[0046] In the lens 61 of this embodiment, the center C2 of the second surface 61b is not the intersection D of the reference axis A and the second surface 61b, but the point where the refracted light Lref reaches the second surface 61b. Therefore, the outgoing light L2 is emitted from the center C2 of the second surface 61b.
[0047] Here, the inclination angle of the refracted light Lref with respect to the reference axis A is φ, the distance from the center C1 to the center C2 in the direction parallel to the reference axis A is T, and the distance from the reference axis A to the center C2 in the direction perpendicular to the reference axis A is S. Then, using trigonometric functions, S is expressed as shown in the following equation (1).
[0048] S=T·tanφ…(1)
[0049] In addition, if the ratio of the absolute refractive index of the material of a lens 61 (i.e., the material of the lens array 60) and air is taken as the refractive index n, then according to Snell's law, sinδ / sin(δ-φ)=n holds. If this equation is expanded, φ is expressed as shown in the following equation (2).
[0050] φ=δ-arcsin(sinδ / n)…(2)
[0051] According to equations (1) and (2), the distance S from the reference axis A to the center C2 of the second surface 61b is determined by n, δ, and T. In addition, the inclination angle θ of the emitted light L2 relative to the reference axis A can be derived from the relationship θ=arcsin(n·sin(δ+φ))-δ.
[0052] As described above, the lens array 60 includes a plurality of lenses 61 arranged such that both the first surface 61a and the second surface 61b are inclined with respect to the reference plane B. Figure 5 , Figure 6 As shown, the lens 61 has a unique shape arranged in a tile-like manner. In addition, Figure 5 is a stereoscopic view of a portion of the lens array 60 as viewed from the first surface 61a side. Figure 6 This is a perspective view of a part of the lens array 60 as viewed from the second surface 61 b side.
[0053] The lens array 60 of this embodiment is as follows Figure 2 As shown in FIG. 1 , the emitted light beam L2 is inclined upward relative to the normal line of the display surface 11 and is set along the line of sight 3a of the user 3. Thus, the light representing the image displayed by the display unit 10 can be efficiently transmitted to the user 3. Figure 2 Schematically shows the optical paths of the light rays entering the center C1 of the first surface 61a and the light rays emitted as a result of the light rays advancing in parallel with the reference axis A in any lens 61. In this figure, the light rays entering the first surface 61a other than the center C1 are omitted for the sake of easy viewing of the drawing, but the light distribution of one lens 61 is set to be wider in the horizontal direction than in the vertical direction corresponding to the display surface 11 which is long in the horizontal direction. Next, for comparison, Figure 7 The light path is represented in the same way.
[0054] Figure 7 The display device 100P according to the comparative example is shown. The backlight unit 20P of the display device 100P has a prism lens 70P in addition to the parallel light emitting unit 40, the diffusion plate 50 and the conventional lens array 60P. The same reference numerals as those in the above embodiment are used for the same structures as those in the above embodiment and the description thereof is omitted.
[0055] In the conventional lens array 60P, the incident light beam L1 and the emitted light beam L2 are kept parallel to the reference axis A. Therefore, as in the display device 100 of the above-mentioned embodiment, when it is desired that the optical axis of the light emitted from the display surface 11 is tilted upward along the line of sight 3a of the user 3, it is necessary to add an optical component such as a prism lens 70P between the lens array 60P and the diffuser 50.
[0056] On the other hand, the lens array 60 of the present embodiment can tilt the optical axis of light emitted from one lens 61 to the optical axis of light incident on the one lens 61. Therefore, according to the lens array 60, when constructing the backlight unit 20 or the display device 100, there is no need to provide additional optical components as in the comparative example, and the number of components can be reduced.
[0057] (Variation Example)
[0058] 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. Figure 8As shown, it can also be set in a display device configured as a head-up display device. The display device 200 is, for example, set in the front panel 2, and emits light representing an image to the windshield 4 of the vehicle 1. The user 3 can visually observe the virtual image V of the image through the light reflected by the windshield 4. In addition to the display unit 10, the backlight unit 20 and the housing 30 that are the same as those in the above embodiment, the display device 200 further includes one or more mirrors that allow the light representing the image displayed on the display unit 10 to go to the windshield 4. The mirror includes a concave mirror.
[0059] In the display device 200, the lens array 60 that determines the inclination angle θ so that the light reflected by the windshield 4 follows the line of sight of the user 3 may be used. Thus, the light representing the image displayed by the display unit 10 can be efficiently transmitted to the user 3.
[0060] In addition, the present invention is not limited to the above-mentioned embodiments, modified examples, and drawings, and can be appropriately modified (including deletion of constituent elements) within the scope of the gist of the present invention.
[0061] In the above description, an example is shown in which both the first surface 61a and the second surface 61b are inclined with respect to the reference plane B. However, in one lens 61, as long as the condition (hereinafter referred to as the basic condition) that the light incident on the center C1 of the first surface 61a in a manner parallel to the reference axis A is emitted from the second surface 61b in a manner inclined with respect to the reference axis A is satisfied, at least one of the first surface 61a and the second surface 61b can be inclined with respect to the reference plane B. In addition, in the above description, an example is shown in which the inclination angles of the first surface 61a and the second surface 61b with respect to the reference plane B are both "δ", but the inclination angles may be different from each other.
[0062] In addition, as long as the above basic conditions are met, the shapes of the first surface 61a and the second surface 61b in a lens 61 can be arbitrary and can be changed according to the purpose, such as convex surface, concave surface, spherical surface, annular surface, plane, etc. In addition, the centers C1 and C2 can be defined in the following manner without relying on the shapes of the first surface 61a and the second surface 61b. The center of the first surface 61a refers to the same position as the optical center point (reference point) when the first surface 61a is drawn on the first surface 61a without being inclined to the reference plane B. Similarly, the center of the second surface 61b refers to the same position as the optical center point (reference point) when the second surface 61b is drawn on the second surface 61b without being inclined to the reference plane B.
[0063] In the above description, in order to facilitate the understanding of the present invention, the description of well-known technical matters has been appropriately omitted.
[0064] The utility model can be implemented in various embodiments and variations without departing from the broad spirit and scope of the utility model. In addition, the above-mentioned embodiments are used to illustrate the utility model and do not limit the scope of the utility model. That is, the scope of the utility model is not represented by the embodiments, but by the claims. Moreover, various variations implemented within the scope of the claims and the scope of the utility model equivalent thereto are deemed to be within the scope of the utility model.
Claims
1. A lens array, comprising a plurality of lenses having first and second surfaces facing opposite directions arranged along a reference plane, characterized in that: In the lens, at least one of the first surface and the second surface is inclined with respect to the reference plane. When an axis perpendicular to the reference plane is taken as a reference axis, in the one lens, light that advances in parallel with the reference axis and enters the center of the first surface is emitted from the second surface in a manner inclined with respect to the reference axis.
2. The lens array according to claim 1, characterized in that: The first surface is inclined to the reference plane, In the one lens, the center of the second surface is a point at which light that advances in parallel with the reference axis and is incident on the center of the first surface and refracted reaches the second surface.
3. The lens array according to claim 1 or 2, characterized in that: The first surface and the second surface are inclined relative to the reference plane in opposite directions.
4. A display device, characterized in that: have: The lens array according to claim 1 or 2; a parallel light emitting unit configured to emit light in a manner parallel to the reference axis toward the lens array; as well as The display unit is illuminated by the light emitted from the parallel light emitting unit and passing through the lens array to display information.