Light-emitting device and display device

Abstract

To provide a light-emitting device and display device suitable for a head-up display with local dimming capability. [Solution] The light-emitting device comprises a plurality of light-emitting elements and a light-transmitting optical member. The optical member has a first surface on the side of the plurality of light-emitting elements and a second surface opposite to the first surface, the first surface having a concave lens-type Fresnel lens portion and the second surface having a plurality of convex lens portions corresponding to each of the plurality of light-emitting elements.

Description

Technical Field

[0001] Embodiments relate to a light-emitting device and a display device.

Background Art

[0002] A head-up display (HUD) that displays an image on the windshield of an automobile has been developed. In the HUD, there is a desire to apply local dimming in order to achieve power saving and high image quality.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An embodiment aims to provide a light-emitting device and a display device suitable for a head-up display capable of local dimming.

Means for Solving the Problems

[0005] The light-emitting device according to the embodiment includes a plurality of light-emitting elements and a translucent optical member. The optical member has a first surface on the side of the plurality of light-emitting elements and a second surface on the opposite side of the first surface, has a concave lens-shaped Fresnel lens portion on the first surface, and has a plurality of convex lens portions corresponding to the plurality of light-emitting elements on the second surface.

[0006] The light-emitting device according to the embodiment includes a plurality of light-emitting elements, a convex lens member having a plurality of convex lens portions corresponding to the plurality of light-emitting elements, and a concave lens member disposed between the plurality of light-emitting elements and the convex lens member and having a concave lens-shaped Fresnel lens portion.

[0007] The display device according to this embodiment comprises the light-emitting device and a liquid crystal panel having a plurality of display areas. Each of the display areas corresponds to one or more of the light-emitting elements, and the plurality of light-emitting elements can be driven for each of the display areas. [Effects of the Invention]

[0008] According to the embodiment, a light-emitting device and display device suitable for a locally dimmable head-up display can be realized. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a plan view showing a light-emitting device according to the first embodiment. [Figure 2] Figure 2 is an end view taken along the line II-II shown in Figure 1. [Figure 3] Figure 3 is an end view showing a display device according to the first embodiment. [Figure 4] Figure 4 shows a schematic configuration of the HUD according to the first embodiment. [Figure 5] Figure 5 is a schematic optical diagram showing a HUD according to the first embodiment. [Figure 6] Figure 6 is a schematic optical diagram showing a HUD relating to the first comparative example. [Figure 7] Figure 7 is a schematic optical diagram showing a HUD relating to the second comparative example. [Figure 8] Figure 8 is a plan view showing a light-emitting device according to the second embodiment. [Figure 9] Figure 9 is an end view taken along the line IX-IX shown in Figure 8. [Figure 10] Figure 10 is an end view showing a light-emitting device according to the third embodiment. [Figure 11] Figure 11 is an end view showing a light-emitting device according to the first modification of the third embodiment. [Figure 12] Figure 12 is an end view showing a light-emitting device according to a second modified example of the third embodiment. [Figure 13]FIG. 13 is an end view showing a light-emitting device according to the fourth embodiment. [Figure 14] FIG. 14 is an end view showing a light-emitting device according to the first modification of the fourth embodiment. [Figure 15] FIG. 15 is an end view showing a light-emitting device according to the second modification of the fourth embodiment. [Figure 16] FIG. 16 is an end view showing a light-emitting device according to the fifth embodiment. [Figure 17] FIG. 17 is an end view showing a light-emitting device according to the sixth embodiment.

MODE FOR CARRYING OUT THE INVENTION

[0010] <First Embodiment> FIG. 1 is a plan view showing a light-emitting device according to the present embodiment. FIG. 2 is an end view taken along the line II-II shown in FIG. 1. FIG. 3 is an end view showing a display device according to the present embodiment. FIG. 4 is a diagram showing a schematic configuration of a HUD according to the present embodiment. FIG. 5 is a schematic optical diagram showing a HUD according to the present embodiment.

[0011] Note that each figure is schematic and is emphasized and simplified as appropriate. Also, between the figures, the shapes, dimensional ratios, positional relationships, etc. of the respective components do not necessarily exactly match. In FIGS. 2, 3, and 5, the light distribution characteristics of each part are shown by broken-line ellipses and arrows, and the longer the arrow, the higher the light emission intensity. Also, in FIG. 5, the optical positional relationship is shown in a simplified manner instead of the actual positional relationship of each component. The same applies to similar figures described later.

[0012] As shown in FIGS. 1 and 2, the light-emitting device 1 according to the present embodiment includes a plurality of light-emitting elements 10 and a translucent optical member 20. The optical member 20 has a first surface 20a on the side of the plurality of light-emitting elements 10 and a second surface 20b on the opposite side of the first surface 20a. Further, the optical member 20 has a concave lens-shaped Fresnel lens portion 31 on the first surface 20a and a plurality of convex lens portions 41 on the second surface 20b. The plurality of convex lens portions 41 respectively correspond to the plurality of light-emitting elements 10. In this specification, that a certain component corresponds to a certain light-emitting element 10 means that the light emitted from the light-emitting element 10 can enter the component.

[0013] The light-emitting element 10 is, for example, a light-emitting diode (LED). The light-emitting element 10 may have, for example, an LED chip that emits blue light and a wavelength conversion member that converts blue light into yellow light, and may emit white light as a whole. Alternatively, the light-emitting element 10 may have an LED chip that emits blue light, an LED chip that emits green light, and an LED chip that emits red light, and may emit white light as a whole. Alternatively, the light-emitting element 10 may have an LED chip that emits blue light, an LED chip that emits green light, and a wavelength conversion member that absorbs blue and / or green light and emits red light, and may emit white light as a whole. The plurality of light-emitting elements 10 are mounted on a wiring board 50, for example.

[0014] The plurality of light-emitting elements 10 are arranged in a matrix in a flat rectangular region 11 that forms a part of the upper surface of the wiring board 50, for example. The region 11 is at least a part of the upper surface of the wiring board 50, for example. Reflectors that optically partition the light-emitting elements 10 from each other may be provided between the light-emitting elements 10. The "region 11" refers to a region that includes all the light-emitting elements 10 in plan view and has the minimum outer edge length. Further, the "center 12 of the region 11" refers to the geometric centroid of the region 11. For example, when the shape of the region 11 is rectangular, it refers to the intersection of the diagonals, and when the shape of the region 11 is circular, it refers to the center of the circle.

[0015] In the examples shown in Figures 1 and 2, the shape of region 11 is square, and nine light-emitting elements 10 are arranged in a 3x3 matrix. The center of the central light-emitting element 10 is located at the center 12 of region 11. However, the shape of region 11, the number of light-emitting elements 10, and their arrangement are not limited to this example. For example, the shape of region 11 may be rectangular, and fifteen light-emitting elements 10 may be arranged in a 3x5 matrix.

[0016] For the sake of explanation, this specification adopts the XYZ Cartesian coordinate system. The arrangement directions of the multiple light-emitting elements 10 are defined as the "X direction" and the "Y direction". The direction perpendicular to the region 11 is defined as the "Z direction". "Plane view" means viewing from the Z direction.

[0017] The optical member 20 is made of, for example, a translucent resin material. In plan view, the shape of the optical member 20 is, for example, rectangular. The multiple Fresnel lens portions 31 are arranged on the first surface 20a of the translucent optical member 20 on the side of the multiple light-emitting elements 10, and each corresponds to one of the multiple light-emitting elements 10. The number of Fresnel lens portions 31 is equal to the number of light-emitting elements 10. In plan view, the shape of each Fresnel lens portion 31 is, for example, rectangular. In each Fresnel lens portion 31, multiple steps are provided concentrically, and the spaces between the steps are concave curved surfaces. Generally, the steps are discontinuous between adjacent Fresnel lens portions 31.

[0018] Each convex lens portion 41 is a curved surface that is convex. Each convex lens portion 41 corresponds to each light-emitting element 10. Therefore, the number of convex lens portions 41 is the same as the number of light-emitting elements 10. Also, the optical axis 41c of each convex lens portion 41 coincides with the optical axis 10c of each light-emitting element 10. The optical axis 10c of the light-emitting element 10 extends in the Z direction and passes through the center of the light-emitting element 10.

[0019] In the light-emitting device 1, the optical axis 10c of each light-emitting element 10 and the optical axis 41c of each convex lens portion 41 may or may not coincide with each other. On the other hand, although the optical axis 31c of the Fresnel lens portion 31 disposed at a position away from the optical axis 1c of the entire light-emitting device 1 extends in the Z direction, it does not coincide with the optical axis 10c of the corresponding light-emitting element 10. The optical axes 31c of these Fresnel lens portions 31 are displaced toward the optical axis 1c side of the entire light-emitting device 1 from the optical axis 10c of the light-emitting element 10 corresponding to this Fresnel lens portion 31. For the light-emitting element 10 whose optical axis 10c coincides with the optical axis 1c of the entire light-emitting device 1, the optical axis 10c coincides with the optical axis 31c of the corresponding Fresnel lens portion 31.

[0020] In other words, among the plurality of Fresnel lens portions 31, the distance L1 between the optical axis 31c_1 of the first Fresnel lens portion 31_1 and the optical axis 31c_2 of the second Fresnel lens portion 31_2 is shorter than the distance L2 between the optical axis 10c_1 of the first light-emitting element 10_1 corresponding to the first Fresnel lens portion 31_1 and the optical axis 10c_2 of the second light-emitting element 10_2 corresponding to the second Fresnel lens portion 31_2. That is, L1 < L2.

[0021] Also, the distance L3 between the optical axis 10c_1 of the first light-emitting element 10_1 and the optical axis 31c_1 of the first Fresnel lens portion 31_1 is shorter than the distance L4 between the optical axis 10c_2 of the second light-emitting element 10_2 and the optical axis 31c_2 of the second Fresnel lens portion 31_2. That is, L3 < L4. In the example shown in FIG. 2, L3 = 0.

[0022] Furthermore, the distance L5 between the center 12 of the region 11 where the plurality of light-emitting elements 10 are arranged and the first light-emitting element 10_1 is shorter than the distance L6 between the center 12 of the region 11 and the second light-emitting element 10_2. That is, L5 < L6. In the example shown in FIG. 2, L5 = 0.

[0023] As shown in Figure 3, the display device 100 according to this embodiment comprises the light-emitting device 1 described above and a liquid crystal panel 200. A diffusion sheet 190 is provided between the light-emitting device 1 and the liquid crystal panel 200. The display device 100 can display any image by driving the light-emitting device 1 and the liquid crystal panel 200.

[0024] The liquid crystal panel 200 has multiple display areas 200a. Each display area 200a corresponds to one or more convex lens portions 41 and one or more light-emitting elements 10 of the light-emitting device 1. In the example shown in Figure 3, one display area 200a corresponds to one convex lens portion 41 and one light-emitting element 10. The multiple light-emitting elements 10 can be driven for each display area 200a. This allows local dimming to be applied to the display device 100.

[0025] As shown in Figure 4, the head-up display (HUD) 300 according to this embodiment includes the above-described display device 100, a concave mirror 301, and a concave mirror 302. The concave mirrors 301 and 302 constitute an optical system 303 having positive refractive power. Light emitted from the display device 100 is reflected by the concave mirror 301, reflected by the concave mirror 302, reflected by the car's windshield 305, and incident on the driver's eye box 310. Note that the optical system 303 having positive refractive power is not limited to a configuration including the concave mirrors 301 and 302, and may include, for example, a plane mirror or a convex lens.

[0026] Next, the operation of this embodiment will be described. As shown in Figure 2, the light distribution characteristics of the light emitted from each light-emitting element 10 are approximately Lambertsian distributions, with the maximum value occurring at the optical axis 10c. The light emitted from each light-emitting element 10 is incident on the first surface 20a of the optical member 20. A concave lens type Fresnel lens portion 31 is provided on the first surface 20a. In each Fresnel lens portion 31, the inclination angle of the first surface 20a with respect to the XY plane increases as it moves away from the optical axis 31c. Therefore, in each Fresnel lens portion 31, the further the light incident at a position away from the optical axis 31c, the more it is refracted in a direction away from the optical axis 31c.

[0027] Light incident on the optical member 20 from the first surface 20a travels through the optical member 20 and exits from the second surface 20b. Since multiple convex lens portions 41 are provided on the second surface 20b of the optical member 20, the light emitted from each convex lens portion 41 is focused by each convex lens portion 41. Light incident on a certain Fresnel lens portion 31 generally exits from the corresponding convex lens portion 41.

[0028] In this way, the light emitted from the light-emitting device 1 exhibits different light distribution characteristics for each convex lens section 41. The light distribution characteristics of the light emitted from each convex lens section 41 are maximized in the direction away from the optical axis 31c of the Fresnel lens section 31, that is, the optical axis 1c of the light-emitting device 1. However, the light distribution characteristics of the light emitted from the light-emitting element 10 whose optical axis 10c coincides with the optical axis 31c are maximized in the direction in which the optical axis 10c extends.

[0029] As a result, the light emitted from the multiple light-emitting elements 10, after passing through the optical element 20, takes on a light intensity distribution such that the light intensity is maximized in the direction away from each other. Thus, the light emitted from the light-emitting device 1 takes on a light intensity distribution such that the light intensity is maximized in the direction away from each other for each portion corresponding to the light-emitting element 10.

[0030] As a result, as shown in Figure 3, the light emitted from the liquid crystal panel 200 of the display device 100 also has a light emission intensity distribution such that the light emission intensity is maximized in the direction away from each other for each part corresponding to each light-emitting element 10 in the liquid crystal panel 200.

[0031] As shown in Figure 4, light emitted from the display device 100 is focused by an optical system 303 having positive refractive power, reflected by the windshield 305, and then incident on the driver's eye box 310. The driver of a vehicle equipped with the HUD 300 can see a virtual image 306 corresponding to the image displayed by the display device 100 on the other side of the windshield 305. The driver can also see the scenery in front of the vehicle through the windshield 305. Therefore, the driver can see the virtual image 306 superimposed on the scenery in front of the vehicle, and can acquire the information displayed by the display device 100 without taking their eyes off the road ahead.

[0032] At this time, as shown in Figure 5, an optical system 303 with positive refractive power is positioned between the display device 100 and the driver. Therefore, of the light emitted from each part of the display device 100, the light emitted away from the optical axis 1c of the light-emitting device 1 is focused onto the driver's eye box 310. This light is emitted in the direction where the light emission intensity is maximum or near that direction according to the light distribution characteristics of each light-emitting element 10. As a result, the driver can perceive the entire virtual image 306 brightly.

[0033] Next, the effects of this embodiment will be described. According to this embodiment, a concave lens-type Fresnel lens portion 31 is provided on the first surface 20a of the light-transmitting optical member 20, and a plurality of convex lens portions 41 are provided on the second surface 20b of the optical member 20. Each of the plurality of convex lens portions 41 corresponds to a plurality of light-emitting elements 10. As a result, the light emitted from the light-emitting device 1 has a light emission intensity distribution such that the light emission intensity is maximized in the direction away from each other for each portion corresponding to the light-emitting element 10.

[0034] As a result, the display device 100 according to this embodiment also has a light emission intensity distribution such that the light emission intensity is maximized in the direction away from each other for each part corresponding to each light-emitting element 10. In this embodiment, since an optical system 303 with positive refractive power is interposed between the display device 100 and the driver, the light emitted from each part of the display device 100 that is emitted in the direction with the maximum light emission intensity or in a direction near thereto is concentrated in the driver's eye box 310. As a result, the driver can perceive the entire virtual image 306 at its original brightness. For example, if the brightness of the image displayed by the display device 100 is uniform, the brightness of the virtual image 306 perceived by the driver will also be close to uniform.

[0035] Furthermore, in this embodiment, the liquid crystal panel 200 has multiple display areas 200a, and one or more light-emitting elements 10 correspond to each display area 200a, and the multiple light-emitting elements 10 can be driven for each display area 200a. Therefore, local dimming can be applied to the display device 100. Accordingly, according to this embodiment, a light-emitting device 1 and a display device 100 suitable for a locally dimmable HUD 300 can be realized.

[0036] Furthermore, according to this embodiment, the Fresnel lens portion 31 and the multiple convex lens portions 41 are integrally formed as an optical member 20. This improves the positional accuracy of the Fresnel lens portion 31 and the convex lens portions 41, reduces the number of parts in the light-emitting device 1, reduces the occurrence of malfunctions, and lowers costs.

[0037] Furthermore, according to this embodiment, a convex lens portion 41 is provided for each light-emitting element 10. This allows the light amplified by the Fresnel lens portion 31 to be focused. As a result, the light-emitting device 1 can be aligned with the optical system of the HUD 300. In addition, by aligning the optical axis 10c of the light-emitting element 10 with the optical axis 41c of the convex lens portion 41, the distance between the light-emitting elements 10 can be secured, thereby reducing heat concentration.

[0038] Furthermore, in this embodiment, since a Fresnel lens section 31 is provided for each light-emitting element 10, high-precision light distribution control becomes possible for each display area 200a of the liquid crystal panel 200.

[0039] The distance between the light-emitting element 10 and the convex lens portion 41 is primarily determined by the required light-gathering performance. When the distance between the light-emitting element 10 and the convex lens portion 41 is fixed, it is preferable for the Fresnel lens portion 31 to be as close to the convex lens portion 41 as possible. The further the Fresnel lens portion 31 is from the light-emitting element 10, the greater the proportion of light that is easy for the Fresnel lens portion 31 to control, and the easier it is to obtain the optical effect of the Fresnel lens portion 31. As a result, the effect of changing the direction of light propagation by the Fresnel lens portion 31 also increases. On the other hand, light that passes through a concave lens type Fresnel lens portion 31 is diffused. This can be adjusted by selecting the curvature of the convex lens portion 41, etc., so that the required light-gathering performance is achieved while taking into account the diffusion effect of the Fresnel lens portion 31. In this way, the angle of deviation can be changed while maintaining light-gathering performance.

[0040] <First Comparative Example> Figure 6 is a schematic optical diagram showing the HUD related to this comparative example. As shown in Figure 6, the light-emitting device 501 in this comparative example does not have a concave Fresnel lens section. Therefore, the light distribution of the light emitted from each convex lens section 41 of the light-emitting device 501 is the same as the light distribution of each light-emitting element 10, and takes its maximum value in the Z direction.

[0041] Of the light emitted from the light-emitting element 10 located near the center 12 of region 11, the light that reaches the driver's eye box 310 via the optical system 303 is the light emitted from the light-emitting element 10 in the Z direction and is the light that takes the maximum value in the light distribution. On the other hand, of the light emitted from the light-emitting element 10 located at a position away from the center 12 of region 11, the light that reaches the driver's eye box 310 via the optical system 303 is the light emitted from the light-emitting element 10 in a direction inclined with respect to the Z direction and is not the light that takes the maximum value in the light distribution. For this reason, the edges of the virtual image 306 appear darker to the driver than the central part.

[0042] <Second Comparative Example> Figure 7 is a schematic optical diagram showing the HUD related to this comparative example. As shown in Figure 7, the light-emitting device 502 in this comparative example is equipped with only one light-emitting element 10. As a result, the light distribution of the light emitted from each part of the liquid crystal panel 200 is tilted away from the optical axis 502c of the light-emitting device 502. As a result, the driver can perceive the virtual image 306 with uniform brightness.

[0043] However, in the light-emitting device 502 of this comparative example, local dimming cannot be applied because the light-emitting element 10 cannot be driven for each display area 200a of the liquid crystal panel 200. The first embodiment described above can be realized by replacing the light-emitting device 502 with the light-emitting device 1 in the HUD of this comparative example. Therefore, there is no need to change the design of the existing HUD.

[0044] <Second Embodiment> Figure 8 is a plan view showing the light-emitting device according to this embodiment. Figure 9 is an end view taken along the line IX-IX shown in Figure 8.

[0045] As shown in Figures 8 and 9, the light-emitting device 2 according to this embodiment differs from the light-emitting device 1 according to the first embodiment in that the optical member 20 has a single concave Fresnel lens portion 32. In plan view, the shape of the Fresnel lens portion 32 is rectangular.

[0046] In the Fresnel lens section 32, multiple circular steps are arranged concentrically, and the spaces between the steps are concave curved surfaces. The optical axis 32c of the Fresnel lens section 32, that is, the straight line passing through the centers of the multiple circular steps, extends in the Z direction and passes, for example, through the center 12 of the region 11 where the multiple light-emitting elements 10 are arranged. Note that the optical axis 32c of the Fresnel lens section 32 does not necessarily have to pass through the center 12 of the region 11. In this embodiment, the optical axis 32c of the Fresnel lens section 32 coincides with the optical axis 2c of the entire light-emitting device 1.

[0047] As a result, the light emitted from the light-emitting element 10 is refracted by the Fresnel lens section 32 in a direction that moves it away from each other. The configuration, operation, and effects in this embodiment other than those described above are the same as in the first embodiment.

[0048] <Third Embodiment> Figure 10 is an end view showing the light-emitting device according to this embodiment. The plan view showing the light-emitting device according to this embodiment is the same as that shown in Figure 8.

[0049] As shown in Figure 10, the light-emitting device 3 according to this embodiment differs from the light-emitting device 2 according to the second embodiment in that it includes a concave lens member 30 and a convex lens member 40 instead of the optical member 20. The concave lens member 30 is arranged between the plurality of light-emitting elements 10 and the convex lens member 40. The arrangement of the plurality of light-emitting elements 10 and the configuration of each light-emitting element 10 are the same as in the second embodiment.

[0050] The concave lens member 30 has a flat surface on the side facing the multiple light-emitting elements 10, while a concave lens-shaped Fresnel lens portion 33 is provided on the surface facing the convex lens member 40. In the concave lens member 30, there is one Fresnel lens portion 33. In the Fresnel lens portion 33, multiple circular steps are arranged concentrically, and the spaces between the steps are concave. The optical axis 33c of the Fresnel lens portion 33 extends in the Z direction and, for example, passes through the center 12 of the region 11 where the multiple light-emitting elements 10 are arranged. In this embodiment, the optical axis 33c of the Fresnel lens portion 33 coincides with the optical axis 3c of the entire light-emitting device 3. Note that the optical axis 33c of the Fresnel lens portion 33 does not necessarily have to pass through the center 12 of the region 11.

[0051] The "optical axis of the light-emitting device" is a straight line that passes through the center of the light-emitting surface of the light-emitting device and extends in the main direction of the light emitted from the light-emitting device. The optical axis of the light-emitting device is, for example, the central axis of the concave lens member 30. In this embodiment, when only one Fresnel lens portion 33 is provided on the concave lens member 30, the optical axis 3c of the light-emitting device 3 coincides with the optical axis 33c of the Fresnel lens portion 33. Also, in many cases, the optical axis of the light-emitting device passes through the center 12 of the region 11 where multiple light-emitting elements 10 are arranged.

[0052] The surface of the convex lens member 40 facing the concave lens member 30 is flat, and a plurality of convex lens portions 41 are provided on the opposite surface of the concave lens member 30. Each of the plurality of convex lens portions 41 corresponds to one of the plurality of light-emitting elements 10, and the optical axis 41c of each convex lens portion 41 coincides, for example, with the optical axis 10c of the corresponding light-emitting element 10.

[0053] In this embodiment, the light emitted from the multiple light-emitting elements 10 is refracted in a direction away from each other by the Fresnel lens portion 33 of the concave lens member 30, and then focused by the multiple convex lens portions 41 of the convex lens member 40. The configuration, operation, and effects of this embodiment other than those described above are the same as in the first embodiment.

[0054] <First modified example of the third embodiment> Figure 11 is an end view showing the light-emitting device according to this modified example. The plan view showing the light-emitting device according to this modified example is the same as that shown in Figure 8.

[0055] As shown in Figure 11, the light-emitting device 3a according to this modified example has a different orientation of the concave lens member 30 compared to the light-emitting device 3 according to the third embodiment. The surface of the concave lens member 30 facing the convex lens member 40 is flat, and the Fresnel lens portion 33 is provided on the surface facing the light-emitting element 10. The surface of the convex lens member 40 facing the concave lens member 30 is flat. The configuration, operation, and effects of this modified example other than those described above are the same as those of the third embodiment.

[0056] <Second modified example of the third embodiment> Figure 12 is an end view showing the light-emitting device according to this modified example. The plan view showing the light-emitting device according to this modified example is the same as that shown in Figure 8.

[0057] As shown in Figure 12, the light-emitting device 3b according to this modified example includes a translucent adhesive member 60 in addition to the configuration of the light-emitting device 3a according to the first modified example. The adhesive member 60 is positioned between the concave lens member 30 and the convex lens member 40. The concave lens member 30 is joined to the convex lens member 40 by the adhesive member 60. The adhesive member 60 is, for example, a solidified adhesive made of a translucent resin.

[0058] In this modified example, compared to the first modified example, there is no air layer between the concave lens member 30 and the convex lens member 40, thus reducing light reflection and absorption at the interface between the concave lens member 30 and the air layer, and at the interface between the air layer and the convex lens member 40. This improves the light extraction efficiency. Furthermore, bonding the concave lens member 30 and the convex lens member 40 improves the mechanical strength of the light-emitting device 3b. The configuration, operation, and effects of this modified example other than those described above are the same as in the third embodiment.

[0059] <Fourth Embodiment> Figure 13 is an end view showing the light-emitting device according to this embodiment. The plan view showing the light-emitting device according to this embodiment is the same as that of Figure 1.

[0060] As shown in Figure 13, this embodiment is an example of combining the first and third embodiments. That is, the light-emitting device 4 according to this embodiment comprises a plurality of light-emitting elements 10, a convex lens member 40 having a plurality of convex lens portions 41 corresponding to each of the plurality of light-emitting elements 10, and a concave lens member 30 disposed between the plurality of light-emitting elements 10 and the convex lens member 40 and having a concave lens type Fresnel lens portion 34.

[0061] The concave lens member 30 has a plurality of Fresnel lens portions 34 corresponding to the plurality of light-emitting elements 10 respectively. The optical axis 34c of each Fresnel lens portion 34 is displaced in a direction approaching the optical axis 4c of the light-emitting device 4, rather than the optical axis 10c of each light-emitting element 10 and the optical axis 41c of each convex lens portion 41. The optical axis 4c of the light-emitting device 4 is a straight line passing through the center 12 of the region 11 where the plurality of light-emitting elements 10 are arranged and extending in the Z direction. Note that the optical axis 4c of the light-emitting device 4 does not necessarily have to pass through the center 12 of the region 11 where the plurality of light-emitting elements 10 are arranged. Also, the optical axis 4c does not necessarily have to coincide with the optical axis 10c of one light-emitting element 10, and does not necessarily have to pass through one light-emitting element 10.

[0062] In other words, among the plurality of Fresnel lens portions 34, the distance L1 between the optical axis 34c_1 of the first Fresnel lens portion 34_1 and the optical axis 34c_2 of the second Fresnel lens portion 34_2 is shorter than the distance L2 between the optical axis 10c_1 of the first light-emitting element 10_1 corresponding to the first Fresnel lens portion 34_1 and the optical axis 10c_2 of the second light-emitting element 10_2 corresponding to the second Fresnel lens portion 34_2. That is, L1 < L2.

[0063] Also, the distance L3 between the optical axis 10c_1 of the first light-emitting element 10_1 and the optical axis 34c_1 of the first Fresnel lens portion 34_1 is shorter than the distance L4 between the optical axis 10c_2 of the second light-emitting element 10_2 and the optical axis 34c_2 of the second Fresnel lens portion 34_2. That is, L3 < L4. In the example shown in FIG. 13, L3 = 0.

[0064] Furthermore, the distance L5 between the center 12 of the region 11 where the plurality of light-emitting elements 10 are arranged and the first light-emitting element 10_1 is shorter than the distance L6 between the center 12 of the region 11 and the second light-emitting element 10_2. That is, L5 < L6. In the example shown in FIG. 13, L5 = 0. The configurations, operations, and effects other than those described above in the present embodiment are the same as those in the first embodiment.

[0065] <First modification of the fourth embodiment> FIG. 14 is an end view showing the light-emitting device according to this modification. The plan view showing the light-emitting device according to this modified example is the same as that shown in Figure 1.

[0066] As shown in Figure 14, the light-emitting device 4a according to this modified example has a different orientation of the concave lens member 30 compared to the light-emitting device 4 according to the fourth embodiment. The surface of the concave lens member 30 facing the convex lens member 40 is flat, and a plurality of Fresnel lens portions 34 are provided on the surface facing the light-emitting element 10. The surface of the convex lens member 40 facing the concave lens member 30 is flat. The configuration, operation, and effects of this modified example other than those described above are the same as those of the fourth embodiment.

[0067] <Second modified example of the fourth embodiment> Figure 15 is an end view showing the light-emitting device according to this modified example. The plan view showing the light-emitting device according to this modified example is the same as that shown in Figure 1.

[0068] As shown in Figure 15, the light-emitting device 4b according to this modified example includes, in addition to the configuration of the light-emitting device 4a according to the first modified example, a light-transmitting adhesive member 60 positioned between the concave lens member 30 and the convex lens member 40. The concave lens member 30 is joined to the convex lens member 40 by the adhesive member 60.

[0069] The configuration of this modified example, other than that described above, is the same as that of the first modified example of the fourth embodiment. The operation and effects of this modified example, other than those described above, are as described in the second modified example of the third embodiment.

[0070] <Fifth Embodiment> Figure 16 is an end view showing a light-emitting device according to this embodiment. The plan view showing the light-emitting device according to this embodiment is the same as that of Figure 1.

[0071] As shown in Figure 16, the light-emitting device 5 according to this embodiment differs from the light-emitting device 4 according to the fourth embodiment in that concave lens-type Fresnel lens portions are provided on both sides of the concave lens member 30.

[0072] Multiple Fresnel lens portions 35 are provided on the surface of the concave lens member 30 facing the light-emitting element 10. Multiple Fresnel lens portions 36 are provided on the surface of the concave lens member 30 facing the convex lens member 40. Each Fresnel lens portion 35 and each Fresnel lens portion 36 corresponds to one of the multiple light-emitting elements 10 and also to one of the multiple convex lens portions 41 of the convex lens member 40. The optical axis 35c of each Fresnel lens portion 35 coincides with the optical axis 36c of each Fresnel lens portion 36.

[0073] According to this embodiment, the optical control surface can be increased by providing Fresnel lens portions on both sides of the concave lens member 30. As a result, the light distribution can be controlled with greater precision. The configuration, operation, and effects of this embodiment other than those described above are the same as those of the fourth embodiment.

[0074] <Sixth Embodiment> Figure 17 is an end view showing the light-emitting device according to this embodiment. As shown in Figure 17, in the light-emitting device 6 according to this embodiment, for example, seven light-emitting elements 10 are arranged along the X direction. The light-emitting elements 10 are arranged at equal intervals, for example. In the light-emitting device 6, multiple light-emitting elements 10 are also arranged at equal intervals along the Y direction. For example, the arrangement period of the light-emitting elements 10 in the X direction is the same as the arrangement period of the light-emitting elements 10 in the Y direction.

[0075] The concave lens member 30 is provided with multiple concave lens-shaped Fresnel lens portions, each corresponding to one of the multiple light-emitting elements 10. The convex lens member 40 is provided with multiple convex lens portions 41, each corresponding to one of the multiple light-emitting elements 10. Note that the lens shapes of each Fresnel lens portion are not shown in Figure 17.

[0076] In the light-emitting device 6, the optical axis 10c of each light-emitting element 10 coincides with the optical axis 41c of each convex lens portion 41 corresponding to the light-emitting element 10. On the other hand, the optical axis of the Fresnel lens portion corresponding to the light-emitting element 10 is displaced relative to the optical axis 10c in a direction toward the optical axis 6c of the light-emitting device 6. This displacement is larger the further the light-emitting element 10 and Fresnel lens portion are from the optical axis 6c. As a result, the further the light-emitting element 10 is from the optical axis 6c, the larger the angle θ between the direction of light emitted from the convex lens portion 41 corresponding to the light-emitting element 10 and the optical axis 6c of the light-emitting device 6. The configuration, operation, and effects in this embodiment other than those described above are the same as in the fourth embodiment.

[0077] The embodiments and their modifications described above are examples that embody the present invention, and the present invention is not limited to these embodiments and modifications. For example, the present invention is also included in the embodiments and modifications described above in which some components are added, deleted, or changed. Furthermore, the embodiments and modifications described above can be implemented in combination with each other.

[0078] The present invention includes the following embodiments.

[0079] (Note 1) Multiple light-emitting elements, A light-transmitting optical member having a first surface on the side of the plurality of light-emitting elements and a second surface opposite to the first surface, the first surface having a concave lens-type Fresnel lens portion and the second surface having a plurality of convex lens portions corresponding to each of the plurality of light-emitting elements, A light-emitting device.

[0080] (Note 2) The light-emitting device according to Appendix 1, wherein the optical component has one Fresnel lens portion.

[0081] (Note 3) The optical member has a plurality of Fresnel lens portions corresponding to each of the plurality of light-emitting elements, The light-emitting device according to Appendix 1, wherein the distance between the optical axis of the first Fresnel lens portion and the optical axis of the second Fresnel lens portion is shorter than the distance between the optical axis of the first light-emitting element corresponding to the first Fresnel lens portion and the optical axis of the second light-emitting element corresponding to the second Fresnel lens portion.

[0082] (Note 4) Multiple light-emitting elements, A convex lens member having a plurality of convex lens portions corresponding to each of the plurality of light-emitting elements, A concave lens member is disposed between the plurality of light-emitting elements and the convex lens member, and has a concave lens-type Fresnel lens portion. A light-emitting device.

[0083] (Note 5) The light-emitting device according to Appendix 4, wherein the concave lens member has one Fresnel lens portion.

[0084] (Note 6) The concave lens member has a plurality of Fresnel lens portions corresponding to each of the plurality of light-emitting elements, The light-emitting device according to Appendix 4, wherein the distance between the optical axis of the first Fresnel lens portion and the optical axis of the second Fresnel lens portion is shorter than the distance between the optical axis of the first light-emitting element corresponding to the first Fresnel lens portion and the optical axis of the second light-emitting element corresponding to the second Fresnel lens portion.

[0085] (Note 7) The surface of the convex lens member on the concave lens member side is flat. The light-emitting device according to any one of appendices 4 to 6, wherein the surface of the concave lens member on the convex lens member side is flat.

[0086] (Note 8) The system further comprises a light-transmitting adhesive member disposed between the concave lens member and the convex lens member, The light-emitting device according to Appendix 7, wherein the concave lens member is joined to the convex lens member by the adhesive member.

[0087] (Note 9) The surface of the convex lens member on the concave lens member side is flat. The light-emitting device according to any one of appendices 4 to 6, wherein the surfaces of the concave lens member on the side of the plurality of light-emitting elements are flat.

[0088] (Note 10) The distance between the optical axis of the first light-emitting element and the optical axis of the first Fresnel lens is shorter than the distance between the optical axis of the second light-emitting element and the optical axis of the second Fresnel lens. The light-emitting device according to Appendix 3 or 6, wherein the distance between the center of the region where the plurality of light-emitting elements are arranged and the first light-emitting element is shorter than the distance between the center of the region and the second light-emitting element.

[0089] (Note 11) The plurality of light-emitting elements are arranged in a matrix within a rectangular region. The light-emitting device according to any one of the appendices 1 to 10, wherein the shape of the Fresnel lens portion is rectangular in a plan view.

[0090] (Note 12) A light-emitting device described in any one of the appendices 1 to 11, A liquid crystal panel having multiple display areas, Equipped with, Each of the display areas corresponds to one or more of the light-emitting elements. The plurality of light-emitting elements are a display device that can be driven for each of the display areas. [Industrial applicability]

[0091] The present invention can be used, for example, in an information display device and its light source for a HUD of a mobile vehicle. [Explanation of Symbols]

[0092] 1, 2, 3, 3a, 3b, 4, 4a, 4b, 5, 6 Light emitting device 1c, 2c, 3c, 4c, 5c, 6c Optical axis of the light-emitting device 10, 10⁻¹, 10⁻² light-emitting elements 10c, 10c_1, 10c_2 Optical axis of light-emitting element 11 Region where multiple light-emitting elements are arranged 12 Center of Region 11 20 Optical components 30 Concave lens component 31, 31_1, 31_2, 32, 33, 34, 34_1, 34_2, 35, 36 Fresnel lens section 31c, 31c_1, 31c_2, 32c, 33c, 34c, 34c_1, 34c_2, 35c, 36c: Optical axis of the Fresnel lens section 40 Convex lens component 41 Convex lens section 41c optical axis 50 Wiring boards 60 Adhesive members 100 display device 190 Diffusion Sheets 200 LCD panels 200a display area 300 Head-Up Displays (HUDs) 301, 302 concave mirror 303 Optical system 305 Windshield 306 Illusion 310 iBox 501, 502 Light-emitting devices 502c Optical axis of the light-emitting device L1 Distance between the optical axis of the first Fresnel lens and the optical axis of the second Fresnel lens. L2 Distance between the optical axis of the first light-emitting element and the optical axis of the second light-emitting element L3 Distance between the optical axis of the first light-emitting element and the optical axis of the first Fresnel lens. L4 Distance between the optical axis of the second light-emitting element and the optical axis of the second Fresnel lens. Distance between the center 12 of region L5 11 and the first light-emitting element Distance between the center 12 of region L6 11 and the second light-emitting element θ is the angle between the direction of light emitted from the convex lens and the optical axis of the light-emitting device.

Claims

1. Multiple light-emitting elements, A light-transmitting optical member having a first surface on the side of the plurality of light-emitting elements and a second surface opposite to the first surface, the first surface having a concave lens-type Fresnel lens portion and the second surface having a plurality of convex lens portions corresponding to each of the plurality of light-emitting elements, A light-emitting device.

2. The light-emitting device according to claim 1, wherein the optical component has one Fresnel lens portion.

3. The optical member has a plurality of Fresnel lens portions corresponding to each of the plurality of light-emitting elements, The light-emitting device according to claim 1, wherein the distance between the optical axis of the first Fresnel lens portion and the optical axis of the second Fresnel lens portion is shorter than the distance between the optical axis of the first light-emitting element corresponding to the first Fresnel lens portion and the optical axis of the second light-emitting element corresponding to the second Fresnel lens portion.

4. Multiple light-emitting elements, A convex lens member having a plurality of convex lens portions corresponding to each of the plurality of light-emitting elements, A concave lens member is disposed between the plurality of light-emitting elements and the convex lens member, and has a concave lens-type Fresnel lens portion. A light-emitting device.

5. The light-emitting device according to claim 4, wherein the concave lens member has one Fresnel lens portion.

6. The concave lens member has a plurality of Fresnel lens portions corresponding to each of the plurality of light-emitting elements, The light-emitting device according to claim 4, wherein the distance between the optical axis of the first Fresnel lens portion and the optical axis of the second Fresnel lens portion is shorter than the distance between the optical axis of the first light-emitting element corresponding to the first Fresnel lens portion and the optical axis of the second light-emitting element corresponding to the second Fresnel lens portion.

7. The surface of the convex lens member on the concave lens member side is flat. The light-emitting device according to claim 4, wherein the surface of the concave lens member on the convex lens member side is flat.

8. The system further comprises a light-transmitting adhesive member disposed between the concave lens member and the convex lens member, The light-emitting device according to claim 7, wherein the concave lens member is joined to the convex lens member by the adhesive member.

9. The surface of the convex lens member on the concave lens member side is flat. The light-emitting device according to claim 4, wherein the surfaces of the concave lens member on the side of the plurality of light-emitting elements are flat.

10. The distance between the optical axis of the first light-emitting element and the optical axis of the first Fresnel lens is shorter than the distance between the optical axis of the second light-emitting element and the optical axis of the second Fresnel lens. The light-emitting device according to claim 3 or 6, wherein the distance between the center of the region in which the plurality of light-emitting elements are arranged and the first light-emitting element is shorter than the distance between the center of the region and the second light-emitting element.

11. The plurality of light-emitting elements are arranged in a matrix within a rectangular region. The light-emitting device according to any one of claims 1 to 9, wherein the shape of the Fresnel lens portion is rectangular in a plan view.

12. A light-emitting device according to any one of claims 1 to 9, A liquid crystal panel having multiple display areas, Equipped with, Each of the display areas corresponds to one or more of the light-emitting elements. The plurality of light-emitting elements are a display device that can be driven for each of the display areas.

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