Illumination device

Abstract

To provide an illumination device that achieves lower costs for head-mounted displays.SOLUTION: According to one embodiment, an illumination device includes light sources, a distributing light guide element, and a light guide. The distributing light guide element has a first side surface facing the light sources, a second side surface on the opposite side of the first side surface, and light waveguides extending from the first side surface towards the second side surface. The light guide has a third side surface facing the second side surface, and a first main surface. Each of the light waveguides has a first end into which light emitted from a corresponding light source enters, and a second end from which light, entering at the first end and propagating within the light waveguide, is emitted. The light emitted from the second end enters the light guide via the second side surface and the third side surface, propagates within the light guide and is emitted from the first main surface.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE The present invention relates to a lighting device. [Background technology]

[0002] 2. Description of the Related Art In recent years, attention has been focused on a technology that provides, for example, virtual reality (VR) using a display device called a head mounted display (HMD) that is worn on a user's head.

[0003] A lighting device constituting such a head mounted display is provided with a large number of laser diodes, but since laser diodes are expensive, a head mounted display that requires a lighting device provided with a large number of laser diodes tends to be expensive. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-026905 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, an object of the present invention is to provide an illumination device that can realize a reduction in the cost of a head mounted display. [Means for solving the problem]

[0006] According to one embodiment, the lighting device includes a plurality of light sources, a distribution light guide element, and a light guide plate. The distribution light guide element has a first side surface facing the plurality of light sources, a second side surface opposite to the first side surface, and a plurality of light guides extending from the first side surface toward the second side surface. The light guide plate has a third side surface facing the second side surface, and a first main surface. Each of the plurality of light guides has a first end portion to which light emitted from the corresponding light source is incident, and a second end portion to which light incident from the first end portion and propagating through the light guide is emitted. The light emitted from the second end portion enters the light guide plate via the second side surface and the third side surface, propagates through the light guide plate, and is emitted from the first main surface.

[0007] According to another embodiment, the lighting device includes a plurality of light sources, a distribution light guide element, a light guide plate, and a reflector. The distribution light guide element has a first side surface facing the plurality of light sources, a second side surface opposite to the first side surface, and a plurality of light guides extending from the first side surface to the second side surface. The light guide plate is located above the distribution light guide element and has a first main surface and a third side surface overlapping the second side surface in a plan view. The reflector faces the second side surface and the third side surface. Each of the plurality of light guides has a first end portion to which light emitted from the corresponding light source is incident, and a second end portion to which light incident from the first end portion and propagating through the light guide is emitted. The light emitted from the second end portion is reflected by the reflector plate, enters the light guide plate, propagates through the light guide plate, and is emitted from the first main surface.

[0008] According to yet another embodiment, the lighting device includes a plurality of light sources, a distribution light guide element, and a reflector. The distribution light guide element has a first side surface facing the plurality of light sources, a second side surface opposite to the first side surface, a first main surface, and a plurality of light guides extending from the first side surface toward the second side surface. The reflector faces the second side surface. Each of the plurality of light guides has a first end portion to which light emitted from a corresponding light source is incident, and a second end portion from which light incident from the first end portion and propagating through the light guide is emitted. The light emitted from the second end portion is reflected by the reflector, propagates through the distribution light guide element, and is emitted from the first main surface. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing an example of the appearance of a display device according to an embodiment. [Diagram 2] FIG. 2 is a perspective view showing a schematic configuration of a display panel provided in the display device according to the embodiment. [Diagram 3] FIG. 3 is a cross-sectional view showing a schematic configuration of the display device according to the embodiment. [Figure 4] FIG. 4 is a schematic plan view of the lighting device according to the first embodiment. [Diagram 5] FIG. 5 is a schematic cross-sectional view of the lighting device according to the first embodiment. [Figure 6] FIG. 6 is a schematic plan view of the illumination device according to the second embodiment. [Figure 7] FIG. 7 is a schematic cross-sectional view of the illumination device according to the second embodiment. [Figure 8] FIG. 8 is a schematic plan view of an illumination device according to a modified example of the second embodiment. [Figure 9] FIG. 9 is a schematic cross-sectional view of an illumination device according to a modified example of the second embodiment. [Figure 10] FIG. 10 is a schematic plan view of an illumination device according to a third embodiment. [Figure 11] FIG. 11 is a schematic cross-sectional view of an illumination device according to a third embodiment. [Figure 12]FIG. 12 is a schematic cross-sectional view of an illumination device according to a third embodiment. [Figure 13] FIG. 13 is a schematic cross-sectional view of an illumination device according to a third embodiment. [Figure 14] FIG. 14 is a schematic cross-sectional view of an illumination device according to a modified example of the third embodiment. [Figure 15] FIG. 15 is a schematic cross-sectional view of an illumination device according to a modified example of the third embodiment. [Figure 16] FIG. 16 is a schematic plan view of an illumination device according to a fourth embodiment. [Figure 17] FIG. 17 is a schematic cross-sectional view of a lighting device according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments will be described with reference to the drawings. In addition, the disclosure is merely an example, and the invention is not limited to the contents described in the following embodiments. Modifications that a person skilled in the art can easily conceive are naturally included in the scope of the disclosure. In order to make the explanation clearer, the size, shape, etc. of each part may be changed from the actual embodiment and shown diagrammatically. In multiple drawings, corresponding elements may be given the same reference numerals, and detailed explanations may be omitted.

[0011] In the drawings, an X-axis, a Y-axis, and a Z-axis that are perpendicular to each other are shown as necessary to facilitate understanding. The direction along the X-axis is called the first direction X, the direction along the Y-axis is called the second direction Y, and the direction along the Z-axis is called the third direction Z. The third direction Z is a normal direction to a plane (XY plane) that includes the first direction X and the second direction Y. Moreover, viewing various elements parallel to the third direction Z is called planar view.

[0012] (First embodiment) 1 is a perspective view showing an example of the appearance of a display device DSP according to an embodiment. The display device DSP according to this embodiment is, for example, a head mounted display (HMD) that is worn on the head of a user USR. The display device DSP is used to provide, for example, virtual reality (VR) to the user USR wearing the display device DSP.

[0013] The display device DSP includes a display panel PNL1 for the left eye and a display panel PNL2 for the right eye. The display panel PNL1 is disposed so as to be located in front of the left eye of the user USR when the user USR wears the display device DSP on his / her head. The display panel PNL2 is disposed so as to be located in front of the right eye of the user USR when the user USR wears the display device DSP on his / her head. As will be described in more detail later, the display panels PNL1 and PNL2 are, for example, liquid crystal display panels having a liquid crystal layer.

[0014] 2 is a perspective view showing a schematic configuration of a display panel PNL1 included in the display device DSP according to the embodiment. Although not shown and described here, the display panel PNL2 has a similar configuration to the display panel PNL1.

[0015] 2, the display panel PNL1 includes a first substrate SUB1 and a second substrate SUB2 opposed to the first substrate SUB1. The display panel PNL1 has a display area DA for displaying an image. In the display area DA, a plurality of pixels PX are arranged in a matrix.

[0016] The display panel PNL1 also includes a drive IC chip IC1 that drives the display panel PNL1, and a flexible circuit board FPC1 that transmits control signals to the display panel PNL1. The flexible circuit board FPC1 is connected to a control module (not shown) that controls the operation of the display device DSP.

[0017] In the example shown in FIG. 2, the first substrate SUB1 and the second substrate SUB2 each have an octagonal shape in plan view. The shapes of the first substrate SUB1 and the second substrate SUB2 can be said to be shapes with corners of a rectangle cut out. Since the shapes of the first substrate SUB1 and the second substrate SUB2 are octagonal, the shape of the display panel PNL1 in plan view can also be said to be octagonal. However, the shape of the display panel PNL1 is not limited to this, and the shape of the display panel PNL1 may be any shape that prevents the display panel PNL1 from hitting the nose of the user USR (that is, a shape having a cutout portion called a nose cut). For example, the shape of the display panel PNL1 may be any polygon or circle with at least one corner close to the nose of the user USR cut out.

[0018] Fig. 3 is a cross-sectional view showing a schematic configuration of a display device DSP according to an embodiment. As shown in Fig. 3, the display device DSP includes two display panels PNL1 and PNL2, a first polarizing plate PL1, a second polarizing plate PL2, a prism sheet PS, and a diffusion sheet DS provided on each of the display panels PNL1 and PNL2, and an illumination device ILD. Note that since the configuration related to the display panel PNL1 is similar to the configuration related to the display panel PNL2, only the configuration related to the display panel PNL1 will be described below, and the description of the configuration related to the display panel PNL2 will be omitted.

[0019] The display panel PNL1 further includes a seal material SAL and a liquid crystal layer LC in addition to the first substrate SUB1 and the second substrate SUB2 described above. In the display panel PNL1, the first substrate SUB1 and the second substrate SUB2 are bonded together by the seal material SAL. The liquid crystal layer LC is sealed between the seal material SAL and each of the substrates SUB1 and SUB2.

[0020] The first polarizer PL1 is disposed on the lower surface of the first substrate SUB1. The second polarizer PL2 is disposed on the upper surface of the second substrate SUB2. The polarization axes of the first polarizer PL1 and the second polarizer PL2 are, for example, perpendicular to each other.

[0021] The illumination device ILD is disposed on the rear side (i.e., the opposite side to the display surface) of the display panels PNL1, PNL2. The illumination device ILD is connected to a control module that controls the operation of the display device DSP. The illumination device ILD illuminates the display panels PNL1, PNL2. By illuminating the display panels PNL1, PNL2 by the illumination device ILD, the display device DSP can display images on the display panels PNL1, PNL2.

[0022] The prism sheet PS is disposed between the display panel PNL1 (display panel PNL2) and the illumination device ILD. The diffusion sheet DS is disposed between the prism sheet PS and the display panel PNL1 (display panel PNL2). The prism sheet PS includes a large number of prisms extending, for example, parallel to the second direction Y. These prisms are formed, for example, on the lower surface of the prism sheet PS. However, these prisms may also be formed on the upper surface of the prism sheet PS.

[0023] The prism sheet PS converts the light illuminated by the illumination device ILD into light substantially parallel to the third direction Z. Here, "light substantially parallel to the third direction Z" includes not only light strictly parallel to the third direction Z, but also light converted by the prism sheet PS such that the inclination with respect to the third direction Z is sufficiently smaller than that when illuminated by the illumination device ILD. From the viewpoint of maintaining the polarization of the light illuminated by the illumination device ILD, it is preferable that the prisms of the prism sheet PS are formed on the lower surface. The light that passes through the prism sheet PS is diffused by the diffusion sheet DS and illuminates the display panels PNL1 and PNL2. Even if the viewing angle of the light that passes through the prism sheet PS is narrow, the viewing angle can be widened by diffusing this light by the diffusion sheet DS.

[0024] Fig. 4 is a schematic plan view of the illumination device ILD according to the first embodiment. Note that, in Fig. 4, among the elements constituting the illumination device ILD, only the elements that illuminate the display panel PNL2 are shown.

[0025] 4, the illumination device ILD includes a plurality of light sources LS1, and a pair of a distribution light guide element 10A and a light guide plate 20A. The distribution light guide element 10A and the light guide plate 20A are adjacently connected in the first direction X.

[0026] The multiple light sources LS1 include a light source LSR that emits a red laser light, a light source LSG that emits a green laser light, and a light source LSB that emits a blue laser light. By including the multiple light sources LS1 in the red light source LSR, the green light source LSG, and the blue light source LSB, it is possible to obtain light of a mixed color (e.g., white) of the colors emitted by these light sources.

[0027] The light sources LS1 may be, for example, laser diodes such as semiconductor lasers that emit laser light. The laser light may be diffuse light that spreads from the irradiation direction. Alternatively, the laser light may be polarized laser light.

[0028] The distribution light-guiding element 10A is made of, for example, a glass material. The distribution light-guiding element 10A has a side surface SS1A facing the multiple light sources LS1 and a side surface SS2A located on the opposite side to the side surface SS1A in the first direction X. The side surface SS2A corresponds to a connection surface with the light guide plate 20A.

[0029] The distribution light-guiding element 10A has a plurality of optical waveguides 11 extending from the side surface SS1A to the side surface SS2A. The plurality of optical waveguides 11 are formed in the distribution light-guiding element 10A, for example, by irradiating glass with a laser beam to partially change the refractive index of the glass. The plurality of optical waveguides 11 include an optical waveguide 11R (shown by a dotted line in FIG. 4) corresponding to a red light source LSR, an optical waveguide 11G (shown by a solid line in FIG. 4) corresponding to a green light source LSG, and an optical waveguide 11B (shown by a dashed line in FIG. 4) corresponding to a blue light source LSB. The optical waveguides 11R, 11G, and 11B are each branched into a number of optical waveguides from a single optical waveguide, and are formed in a hierarchical manner over almost the entire surface of the first light guide plate 10A except for a partial region described later.

[0030] The light guide plate 20A is formed of, for example, a resin material or a glass material. The refractive index of the distribution light guide element 10A and the refractive index of the light guide plate 20A are preferably approximately the same. The light guide plate 20A has a side surface SS3A connected to the side surface SS2A of the distribution light guide element 10A, and faces the display panel PNL2. The area of ​​the light guide plate 20A in a plan view is preferably larger than the area of ​​the display panel PNL2 in a plan view.

[0031] Here, the planar shape of the distribution light-guiding element 10A will be described. The distribution light-guiding element 10A has sides S1 to S9.

[0032] The side S1 corresponds to the side surface SS1A and extends along the second direction Y. Sides S2 to S4 are sides corresponding to the side surface SS2A (connecting surface). Side S2 is an oblique side extending in a direction that forms an angle θa with respect to the first direction X in the XY plane. Side S4 is an oblique side extending in a direction that forms an angle θa with respect to the first direction X in the XY plane and that intersects with the direction in which the above-mentioned side S2 extends. Side S3 is a side that connects one end of side S2 to one end of side S4, and extends in the second direction Y. Note that, here, the angle that side S2 makes with respect to the first direction X in the XY plane and the angle that side S4 makes with respect to the first direction X in the XY plane are both angle θa, but the angle that side S2 makes with respect to the first direction X in the XY plane and the angle that side S4 makes with respect to the first direction X in the XY plane may be different.

[0033] The side S5 is a side that connects one end of the side S1 and the other end of the side S2, and extends along the first direction X. Side S6 extends from the other end of side S1 along the first direction X. Side S7 extends from the other end of side S4 along the first direction X toward side S6. Sides S6 and S7 are spaced apart.

[0034] Side S8 is a hypotenuse extending from one end of side S6 in a direction that forms an angle θb with the first direction X in the XY plane. Side S9 is a hypotenuse extending from one end of side S7 in a direction that forms an angle θb with the first direction X in the XY plane and that intersects with the direction in which side S8 extends. Sides S8 and S9 intersect at intersection P1. This allows an isosceles triangular cutout (nose cut) to be formed in the distribution light guide element 10A.

[0035] As shown in FIG. 4, the optical waveguide 11 is not formed in the area surrounded by a virtual line VL1 extending from the intersection point P1 along the first direction X, a part of the side S1 extending from the intersection point P2 between the virtual line VL1 and the side S1 toward the side S6, the side S6, and the side S8.

[0036] Next, the planar shape of the light guide plate 20A will be described. The light guide plate 20A has sides S10 to S15.

[0037] Sides S10 to S12 correspond to the side surface SS3A (connecting surface). Side S10 is an oblique side extending along a direction that forms an angle θc (=180-θa) with the first direction X in the XY plane. Side S12 is an oblique side extending along a direction that forms an angle θc with the first direction X in the XY plane and intersects with the direction in which the above-mentioned side S10 extends. Side S11 is a side that connects one end of side S10 and one end of side S12, and extends along the second direction Y. Sides S10 to S12 overlap (are in contact with) sides S2 to S4 of the distribution light-guiding element 10A in a plan view.

[0038] The side S13 is the side opposite to the side S11 in the first direction X and extends along the second direction Y. Side S14 is a side that connects the other end of side S10 and one end of side S13, and extends along the first direction X. The side S15 is a side that connects the other end of the side S12 and the other end of the side S13, and extends along the first direction X.

[0039] FIG. 5 is a schematic cross-sectional view of the illumination device ILD according to the first embodiment. 5, the illumination device ILD includes a light source LS1, a pair of a distribution light guide element 10A and a light guide plate 20A for illuminating the display panel PNL2, and a light source LS2, a pair of a distribution light guide element 10B and a light guide plate 20B for illuminating the display panel PNL1. In the following, when it is not necessary to distinguish between the distribution light guide elements 10A and 10B, they may be simply referred to as the distribution light guide element 10. Similarly, when it is not necessary to distinguish between the light guide plates 20A and 20B, they may be simply referred to as the light guide plate 20, and when it is not necessary to distinguish between the light sources LS1 and LS2, they may be simply referred to as the light source LS.

[0040] The distribution light-guiding element 10A has a main surface MS1A facing the display panel PNL1, a main surface MS2A located on the opposite side of the main surface MS1A in the third direction Z, a side surface SS1A facing the light source LS1, and a side surface SS2A located on the opposite side of the side surface SS1A in the first direction X. The light guide plate 20A has a main surface MS3A facing the display panel PNL2, a main surface MS4A located on the opposite side of the main surface MS3A in the third direction Z, a side surface SS3A in contact with the side surface SS2A of the distribution light-guiding element 10A, and a side surface SS4A located on the opposite side of the side surface SS3A in the first direction X. A prism layer P1 including a plurality of prisms is provided on the main surface MS4A of the light guide plate 20A.

[0041] The distribution light-guiding element 10B has a main surface MS1B facing the main surface MS4A of the light guide plate 20A, a main surface MS2B located on the opposite side of the main surface MS1B in the third direction Z, a side surface SS1B facing the light source LS2, and a side surface SS2B located on the opposite side of the side surface SS1B in the first direction X. The light guide plate 20B has a main surface MS3B facing the main surface MS2A of the distribution light-guiding element 10A, a main surface MS4B located on the opposite side of the main surface MS3B in the third direction Z, a side surface SS3B in contact with the side surface SS2B of the distribution light-guiding element 10B, and a side surface SS4B located on the opposite side of the side surface SS3B in the first direction X. A prism layer P2 including a plurality of prisms is provided on the main surface MS4B of the light guide plate 20B.

[0042] As shown in FIG. 5, the distribution light guide elements 10A and 10B at least partially overlap each other in a plan view.

[0043] The light distribution and guiding element 10A has a light guide 11R corresponding to the red light source LSR, a light guide 11G corresponding to the green light source LSG, and a light guide 11B corresponding to the blue light source LSB. The light guides 11R, 11G, and 11B are formed in a hierarchical manner in different layers (heights) of the light distribution and guiding element 10A. FIG. 5 shows a case where the light guides 11R, 11G, and 11B are arranged in this order from the top, but the light guides 11R, 11G, and 11B may be arranged in a different order from that shown in FIG. 5. Also, FIG. 5 shows only one each of the light guides 11R, 11G, and 11B, but a plurality of each of the light guides 11R, 11G, and 11B may be formed in a hierarchical manner.

[0044] Each of the optical waveguides 11R, 11G, and 11B has an end 11a (in other words, the end 11a on the side surface SS1A side) where the light irradiated from the light source LS1 is incident, and an end 11b (in other words, the end 11b on the side surface SS2A side) where the light is emitted. For example, the light irradiated from the red light source LSR is incident on the distribution light-guiding element 10A, and when it is incident on the optical waveguide 11R from the end 11a, it propagates through the optical waveguide 11R and is emitted from the end 11b toward the light guide plate 20A. Similarly, the light irradiated from the green light source LSG is incident on the distribution light-guiding element 10A, and when it is incident on the optical waveguide 11G from the end 11a, it propagates through the optical waveguide 11G and is emitted from the end 11b toward the light guide plate 20A. Furthermore, light emitted from blue light source LSB enters distribution light guide element 10A, enters optical waveguide 11B from end 11a, propagates through optical waveguide 11B, and is emitted from end 11b toward light guide plate 20A.

[0045] The optical waveguides 11R, 11G, and 11B formed in the distribution light-guiding element 10A are bent in the third direction Z (downward) near the end portion 11b. More specifically, the optical waveguides 11R, 11G, and 11B are bent downward at an angle θd (for example, 26.5°) with respect to the first direction X in the XZ plane. Although the distribution light-guiding element 10A has been described as an example here, the distribution light-guiding element 10B also has a similar structure.

[0046] Of the light emitted from the ends 11b of the optical waveguides 11R, 11G, and 11B and incident on the light guide plate 20A, the light traveling toward the main surface MS3A is reflected at the interface between the main surface MS3A of the light guide plate 20A and the air layer. Also, of the light incident on the light guide plate 20A, the light traveling toward the main surface MS4A has its traveling direction changed by the prism layer P1 provided on the main surface MS4A. The light whose traveling direction has been changed by the prism layer P1 is not in compliance with the total reflection condition of the main surface MS3A and is emitted from the main surface MS3A. The light emitted from the main surface MS3A is converted by the prism sheet PS into light substantially parallel to the third direction Z, and then diffused by the diffusion sheet DS to illuminate the display panel PNL2.

[0047] Similarly, of the light emitted from the ends 11b of the optical waveguides 11R, 11G, and 11B and incident on the light guide plate 20B, the light traveling toward the main surface MS3B is reflected at the interface between the main surface MS3B of the light guide plate 20B and the air layer. Also, of the light incident on the light guide plate 20B, the light traveling toward the main surface MS4B has its traveling direction changed by the prism layer P2 provided on the main surface MS4B. The light whose traveling direction has been changed by the prism layer P2 is not in compliance with the total reflection condition of the main surface MS3B and is emitted from the main surface MS3B. The light emitted from the main surface MS3B passes through the distribution light guide element 10A, is converted by the prism sheet PS into light substantially parallel to the third direction Z, and is then diffused by the diffusion sheet DS to illuminate the display panel PNL1.

[0048] The illumination device ILD according to the first embodiment described above includes the light distribution guide elements 10A and 10B having a plurality of light guides 11R corresponding to the red light source LSR, a plurality of light guides 11G corresponding to the green light source LSG, and a plurality of light guides 11B corresponding to the blue light source LSB. According to this, if at least one red light source LSR, one green light source LSG, and one blue light source LSB are provided for each of the light distribution guide elements 10A and 10B, it is possible to supply light to the entire surfaces of the side surfaces SS3A and SS3B of the light guide plates 20A and 20B through the light guides 11R, 11G, and 11B. In other words, the number of laser diodes provided in the illumination device ILD can be reduced, and the cost of the illumination device ILD and the cost of the display device DSP can be reduced.

[0049] The light emitted from the ends 11b of the optical waveguides 11R, 11G, and 11B is emitted toward the display panels PNL1 and PNL2. That is, the light emitted from the ends 11b located in the second direction Y enters the light guide plates 20A and 20B from the side surfaces SS3A and SS3B facing the ends 11b and is emitted toward the display panels PNl1 and PNL2. However, since the display panel PNL2 is octagonal, the light emitting area in the upper and lower parts in the second direction Y in a plan view is smaller than that of the center part in the second direction Y. Therefore, if the ends 11b of the optical waveguides 11R, 11G, and 11B are uniformly arranged in the second direction Y, the luminance in the second direction Y is not uniform. In order to make the brightness in the second direction Y uniform, it is necessary to make the intensity of the light emitted from each end 11b at the upper and lower parts in the second direction Y weaker than the intensity of the light emitted from each end 11b at the center in the second direction Y. For this reason, the pitches of the ends 11b of the multiple optical waveguides 11R, 11G, and 11B are made different. Specifically, the pitches of the ends 11b are made longer at the upper and lower parts in the second direction Y than at the center in the second direction Y. This makes it possible to emit light with uniform brightness toward the display panels PNL1 and PNL2.

[0050] Furthermore, even if the distribution light guide elements 10A, 10B have a cutout portion (nose cut), by forming the multiple optical waveguides 11R, 11G, 11B in a curved shape, as described above, the ends 11b of the multiple optical waveguides 11R, 11G, 11B can be positioned over the entire surface of the side surfaces SS3A, SS3B of the light guide plates 20A, 20B. In other words, even if the illumination device ILD according to the first embodiment has a cutout portion (nose cut), the chromaticity and luminance of the light emitted from the main surfaces MS3A, MS3B of the light guide plates 20A, 20B can be made uniform. This makes it possible to suppress the occurrence of the above-mentioned color breakup.

[0051] Although it is sufficient that at least one red light source LSR, one green light source LSG, and one blue light source LSB are provided for each of the light distribution-guiding elements 10A and 10B, the curvature of the optical waveguides 11R, 11G, and 11B can be made gentler by increasing the number of light sources of each color provided for each of the light distribution-guiding elements 10A and 10B. This makes it easier to form the optical waveguides 11R, 11G, and 11B than when the optical waveguides 11R, 11G, and 11B have steep curvatures formed in the light distribution-guiding elements 10A and 10B.

[0052] In addition, in this embodiment, it is assumed that the distribution light-guiding element 10 and the light guide plate 20 are formed separately, but a structure corresponding to the distribution light-guiding element 10 and a structure corresponding to the light guide plate 20 may be formed from a single piece of glass, and a structure corresponding to the prism layer P may be provided (attached) below the structure corresponding to the light guide plate 20, thereby forming a pair of structures corresponding to the distribution light-guiding element 10 and the light guide plate 20.

[0053] Second embodiment Next, a second embodiment will be described. In the second embodiment, an illumination device ILD mounted on a display device DSP that does not support nose cuts will be described. For this reason, although details will be described later, the illumination device ILD according to the second embodiment differs from the first embodiment in that it has a rectangular shape in a plan view and does not have a cutout portion (nose cut). Note that, in the following, a description of the same parts as in the first embodiment will be omitted.

[0054] Fig. 6 is a schematic plan view of an illumination device ILD according to the second embodiment. Note that, in Fig. 6, among the elements constituting the illumination device ILD, only the elements that illuminate the display panel PNL2 are shown.

[0055] As shown in Fig. 6, the distribution light-guiding element 10A has a rectangular shape in a plan view. The distribution light-guiding element 10A has a plurality of optical waveguides 11 extending from a side surface SS1A facing the plurality of light sources LS1 toward a side surface SS2A, similar to the configuration shown in Fig. 4. The plurality of optical waveguides 11 are disposed over the entire surface of the distribution light-guiding element 10A, which is different from the structure shown in Fig. 4.

[0056] As shown in Fig. 6, the shape of the light guide plate 20A in a plan view is also rectangular. The light guide plate 20A is disposed at a predetermined interval in the first direction X from the side surface SS2A of the distribution light guide element 10A, and faces the rectangular display panel PNL2. Although details will be described later, the light guide plate 20A may be disposed at a position where light emitted from the multiple optical waveguides 11 formed in the distribution light guide element 10A can be incident. In other words, the light guide plate 20A may be disposed at a predetermined interval in the first direction X from the side surface SS2A of the distribution light guide element 10A as shown in Fig. 6, or may be disposed so as to be in contact with the side surface SS2A of the distribution light guide element 10A in a plan view.

[0057] 7 is a schematic cross-sectional view of an illumination device ILD according to embodiment 2. Since a pair of distribution-guiding elements 10A and light guide plate 20A and a pair of distribution-guiding elements 10B and light guide plate 20B have a similar structure, only the distribution-guiding element 10A and light guide plate 20A will be described below, and a description of the distribution-guiding element 10B and light guide plate 20B will be omitted.

[0058] 7, in the illumination device ILD according to the second embodiment, the distribution light-guiding element 10A and the light guide plate 20A are arranged in the first direction X at a predetermined interval. The thickness (length in the third direction Z) of the distribution light-guiding element 10A is smaller than the thickness of the light guide plate 20A. However, the thickness of the distribution light-guiding element 10A may be the same as the thickness of the light guide plate 20A.

[0059] The optical waveguides 11R, 11G, and 11B formed in the distribution light-guiding element 10A extend parallel to the XY plane and are not bent downward near the end 11b, which is different from the structure shown in FIG. 5. The light emitted from the end 11b of the optical waveguides 11R, 11G, and 11B proceeds along the normal direction of the side surface SS2A and is emitted from the distribution light-guiding element 10A without being refracted (almost without being refracted) at the side surface SS2A. In reality, the light emitted from the end 11b of the optical waveguides 11R, 11G, and 11B is diffuse light, so a part of it is refracted at the side surface SS2A and is emitted from the distribution light-guiding element 10A. The light guide plate 20A may be disposed in the vicinity of the distribution light-guiding element 10A to such an extent that all of such light emitted from the distribution light-guiding element 10A can be incident thereon.

[0060] The side surface SS3A of the light guide plate 20A is inclined at an angle θe with respect to the main surface MS3A. This allows the light emitted from the distribution light guide element 10A to be refracted by the side surface SS3A and enter the light guide plate 20A. The light that enters the light guide plate 20A propagates through the light guide plate 20A, and its traveling direction is changed by the prism layer P1 provided on the main surface MS4A, and the light is emitted from the main surface MS3A without satisfying the total reflection condition of the main surface MS3A. Note that, for convenience of illustration, FIG. 7 shows the state in which the light before hitting the prism layer P1 is emitted from the main surface MS3A, but in reality, as described above, the light whose traveling direction has been changed by the prism layer P1 is emitted from the main surface MS3A. The light that exits from the main surface MS3A is converted by the prism sheet PS into light that is substantially parallel to the third direction Z, and then diffused by the diffusion sheet DS to illuminate the display panel PNL2. The angle θe is preferably set so that the light propagating within the light guide plate 20A forms an angle θd (for example, 26.5°) with the first direction X on the XZ plane.

[0061] The illumination device ILD according to the second embodiment described above can achieve the same effects as the first embodiment described above, except that it does not support the nose cut.

[0062] In addition, in the illumination device ILD according to the second embodiment, the optical waveguides 11R, 11G, and 11B formed in the distribution light guide elements 10A and 10B do not need to be bent downward near the end portions 11b, so that the optical waveguides 11R, 11G, and 11B can be formed more easily in the distribution light guide elements 10A and 10B than in the structure according to the first embodiment. On the other hand, in the illumination device ILD according to the second embodiment, in order to make the light emitted from the distribution light guide elements 10A and 10B enter the light guide plates 20A and 20B, the side surfaces SS3A and SS3B of the light guide plates 20A and 20B need to be inclined at an angle θe with respect to the main surfaces MS3A and MS3B, but forming the light guide plates 20A and 20B having the inclined side surfaces SS3A and SS3B is easier than bending the optical waveguides 11R, 11G, and 11B downward. Therefore, the illumination device ILD according to the second embodiment can be manufactured more easily than the illumination device ILD according to the first embodiment.

[0063] (Modification of the second embodiment) Here, a modified example of the second embodiment will be described. The illumination device ILD according to the modified example of the second embodiment differs from the second embodiment in that it individually illuminates the display panels PNL1 and PNL2. For ease of explanation, the illumination device ILD that illuminates the display panel PNL1 may be referred to as the illumination device ILD1, and the illumination device ILD that illuminates the display panel PNL2 may be referred to as the illumination device ILD2. Note that, in the following, explanations of parts similar to those of the second embodiment will be omitted.

[0064] FIG. 8 is a schematic plan view of illumination devices ILD1 and ILD2 according to the second embodiment. 8, the illumination device ILD1 includes a light source LS1, a pair of distribution light guide elements 10A, and a light guide plate 20A. Similarly, the illumination device ILD2 includes a light source LS2, a pair of distribution light guide elements 10B, and a light guide plate 20B. Note that since the illumination devices ILD1 and ILD2 have similar structures, only the illumination device ILD1 will be described below, and a description of the illumination device ILD2 will be omitted.

[0065] As shown in Fig. 8, the distribution light-guiding element 10A has a rectangular shape in a plan view. The distribution light-guiding element 10A has a plurality of light waveguides 11 extending from a side surface SS1A facing the plurality of light sources LS1 toward a side surface SS2A, similar to the structure shown in Fig. 6. The plurality of light waveguides 11 are disposed over the entire surface of the distribution light-guiding element 10A, which is similar to the structure shown in Fig. 6. However, the distribution light-guiding element 10A according to the modification is different from the structure shown in Fig. 6 in that the length in the first direction X is shorter than that of the distribution light-guiding element 10A according to the second embodiment, the length of the light waveguides 11 is also shorter, and the curvature of the light waveguides 11 is steeper.

[0066] As shown in Fig. 8, the light guide plate 20A has a hexagonal shape in a plan view, which can be considered as a shape in which two corners on the side surface SS4A side of the rectangular light guide plate 20A shown in Fig. 6 are cut out. The light guide plate 20A is disposed at a predetermined distance in the first direction X from the side surface SS2A of the distribution light guide element 10A, and faces the octagonal display panel PNL1. As described above, since the display panel PNL1 and the light guide plate 20A have a shape with a cutout portion (nose cut), the illumination device ILD1 according to the modification can be mounted on a display device DSP compatible with nose cuts.

[0067] The light guide plate 20A may be disposed at a predetermined distance in the first direction X from the side surface SS2A of the distribution light-guiding element 10A as shown in FIG. 8, or may be disposed so as to be in contact with the side surface SS2A of the distribution light-guiding element 10A in a plan view.

[0068] Fig. 9 is a schematic cross-sectional view of the illumination devices ILD1 and ILD2 according to a modification of the second embodiment. The pair of distribution light guide elements 10A and light guide plate 20A, and the pair of distribution light guide elements 10B and light guide plate 20B each have a cross-sectional structure similar to that shown in Fig. 7, and therefore detailed description thereof will be omitted here. However, the difference from the second embodiment is that light irradiated from the light source LS1, incident on the light guide plate 20A via the distribution light guide element 10A, and emitted from the main surface MS3A of the light guide plate 20A illuminates the display panel PNL1, and light irradiated from the light source LS2, incident on the light guide plate 20B via the distribution light guide element 10B, and emitted from the main surface MS3B of the light guide plate 20B illuminates the display panel PNL2.

[0069] The illumination device ILD according to the modification of the second embodiment described above can be mounted on a display device DSP corresponding to a nose cut, and can achieve the same effects as those of the first embodiment described above. The illumination device ILD according to the modification of the second embodiment can be mounted not only on a display device DSP serving as a head-mounted display, but also on a display device DSP in which a display panel PNL is disposed only in front of one eye, a display device DSP serving as a smartphone, a display device DSP serving as a monitor, and the like.

[0070] Third embodiment Next, a third embodiment will be described. The illumination device ILD according to the third embodiment differs from the illumination devices ILD of the first and second embodiments in that it individually illuminates the display panels PNL1 and PNL2. In the following, for convenience of explanation, the illumination device ILD that illuminates the display panel PNL1 may be referred to as the illumination device ILD1, and the illumination device ILD that illuminates the display panel PNL2 may be referred to as the illumination device ILD2.

[0071] Furthermore, the illumination device ILD of the third embodiment differs from the first embodiment, the second embodiment, and the modified example of the second embodiment in that a pair of distribution-guiding elements 10 and a light guide plate 20 are arranged side by side in the third direction Z, more specifically, in that the pair of distribution-guiding elements 10 and a light guide plate 20 are arranged so as to overlap in a planar view. In the following, a description of the same parts as those in the first embodiment, the second embodiment, and the modified example of the second embodiment will be omitted.

[0072] FIG. 10 is a schematic plan view of illumination devices ILD1 and ILD2 according to the third embodiment. 10, the illumination device ILD1 includes a light source LS1, a pair of distribution light guide elements 10A and a light guide plate 20A, and a reflector REF1. Similarly, the illumination device ILD2 includes a light source LS2, a pair of distribution light guide elements 10B and a light guide plate 20B, and a reflector REF2. Note that since the illumination devices ILD1 and ILD2 have similar structures, only the illumination device ILD1 will be described below, and a description of the illumination device ILD2 will be omitted.

[0073] As shown in Fig. 10, the distribution light-guiding element 10A has a pentagonal shape in plan view, which can be said to be a shape obtained by cutting out one corner on the side surface SS2A side of the rectangular distribution light-guiding element 10A shown in Fig. 6. The distribution light-guiding element 10A has a side surface SS1A, a side surface SS2A located on the opposite side of the side surface SS1A in the first direction X, a side surface SS5A facing the multiple light sources LS1, and a side surface SS6A located on the opposite side of the side surface SS5A in the second direction Y. The distribution light-guiding element 10A has multiple optical waveguides 11R, 11G, and 11B extending from the side surface SS5A toward the side surface SS6A. The multiple optical waveguides 11R, 11G, and 11B are arranged in a hierarchical manner over the entire surface of the distribution light-guiding element 10A.

[0074] As shown in Fig. 10, the light guide plate 20A is disposed so as to overlap the distribution light-guiding element 10A in a plan view, and has a side surface SS3A overlapping with the side surface SS1A of the distribution light-guiding element 10A, a side surface SS4A overlapping with the side surface SS2A of the distribution light-guiding element 10A, a side surface SS7A overlapping with the side surface SS5A of the distribution light-guiding element 10A, and a side surface SS8A overlapping with the side surface SS6A of the distribution light-guiding element 10A. The shape of the light guide plate 20A in a plan view is pentagonal like the distribution light-guiding element 10A, and can be said to be a shape in which one corner on the side surface SS4A side of the rectangular light guide plate 20A shown in Fig. 6 is cut out. The light guide plate 20A faces the octagonal display panel PNL1. As described above, since the display panel PNL1, the distribution light-guiding element 10A, and the light-guiding plate 20A have shapes with cutout portions (nose cuts), the illumination device ILD1 of the third embodiment can be mounted on a display device DSP that is compatible with nose cuts.

[0075] The distribution light-guiding element 10A and the light guide plate 20A are disposed so that a part of the distribution light-guiding element 10A contacts a part of the light guide plate 20A. That is, the light emitted from the distribution light-guiding element 10A enters the light guide plate 20A without being reflected at the interface.

[0076] Although details will be described later, the reflector REF1 is disposed at a position facing the side surface SS6A of the distribution light-guiding element 10A and the side surface SS8A of the light guide plate 20A as shown in Fig. 10. The reflector REF1 may be disposed so as to be in contact with the side surface SS6A of the distribution light-guiding element 10A and the side surface SS8A of the light guide plate 20A in a plan view, or may be disposed at a predetermined interval in the second direction Y from the side surface SS6A and the side surface SS8A.

[0077] Fig. 11 is a schematic cross-sectional view of an illumination device ILD1 according to embodiment 3. As shown in Fig. 11, optical waveguides 11R, 11G, and 11B are formed in layers along the third direction Z in a distribution light-guiding element 10A.

[0078] The distribution light-guiding element 10A has a main surface MS1A facing the light-guiding plate 20A, a main surface MS2A located on the opposite side of the main surface MS1A in the third direction Z, a side surface SS5A facing the light source LS1, and a side surface SS6A located on the opposite side of the side surface SS5A in the second direction Y and facing the reflector REF1.

[0079] The light guide plate 20A has a main surface MS3A facing the display panel PNL1, a main surface MS4A located on the opposite side of the main surface MS3A in the third direction Z and facing the main surface MS1A of the distribution light-guiding element 10A, a side SS7A overlapping with the side SS5A of the distribution light-guiding element 10A, and a side SS8A facing the reflector REF1 and overlapping with the side SS6A of the distribution light-guiding element 10A.

[0080] The optical waveguides 11R, 11G, and 11B formed in the distribution light-guiding element 10A are bent in the third direction Z (upward) near the ends 11b. More specifically, the optical waveguides 11 are bent upward at an angle θd (for example, 26.5°) with respect to the second direction Y in the YZ plane.

[0081] The light emitted from the end 11b of the optical waveguide 11R, 11G, 11B is reflected by the reflector REF1. The light reflected by the reflector REF1 travels toward the main surface MS3A of the light guide plate 20A and is reflected at the interface between the main surface MS3A of the light guide plate 20A and the air layer. The light totally reflected by the main surface MS3A travels toward the main surface MS4A and its traveling direction is changed by the prism layer P1 provided on the main surface MS4A. The light whose traveling direction is changed by the prism layer P1 is not in compliance with the total reflection condition of the main surface MS3A and is emitted from the main surface MS3A. The light emitted from the main surface MS3A is converted by the prism sheet PS into light substantially parallel to the third direction Z, and then diffused by the diffusion sheet DS to illuminate the display panel PNL1. Although the illumination device ILD1 has been described as an example here, the illumination device ILD2 also has a similar structure.

[0082] The illumination device ILD according to the third embodiment described above can be mounted on a display device DSP that supports nose cuts, and can achieve the same effects as those of the first embodiment described above. The illumination device ILD according to the third embodiment can be mounted not only on a display device DSP as a head-mounted display, but also on a display device DSP in which a display panel PNL is arranged only in front of one eye, a display device DSP as a smartphone, a display device DSP as a monitor, and the like. Furthermore, the illumination device ILD according to the third embodiment can contribute to narrowing the frame of the display device DSP because a pair of distribution light-guiding elements 10 and a light-guiding plate 20 are arranged side by side in the third direction Z.

[0083] In this embodiment, it is assumed that the cross-sectional shape of the light guide plate 20A is a so-called inverted wedge shape as shown in Fig. 11, but the cross-sectional shape of the light guide plate 20A is not limited to this, and may be a rectangle as shown in Fig. 12. Also, in Fig. 11, only one each of the optical waveguides 11R, 11G, and 11B is shown, but a plurality of each of the optical waveguides 11R, 11G, and 11B may be formed in layers as shown in Fig. 13.

[0084] (Modification of the third embodiment) Here, a modified example of the third embodiment will be described. The illumination device ILD according to the modified example of the third embodiment differs from the third embodiment in that the distribution light guide element 10 and the light guide plate 20 are integrated. In the following, the description of the same parts as those of the third embodiment will be omitted.

[0085] Fig. 14 is a schematic cross-sectional view of an illumination device ILD1 according to a modified example of the third embodiment. As shown in Fig. 14, optical waveguides 11R, 11G, and 11B are formed in layers along the third direction Z in a distribution light-guiding element 10A.

[0086] 14, the illumination device ILD1 includes a light source LS1, a distribution light-guiding element 10A, and a reflector REF1. The distribution light-guiding element 10A has a main surface MS1A facing the display panel PNL1, a main surface MS2A located on the opposite side of the main surface MS1A in the third direction Z and on which a prism layer P1 is provided, a side surface SS5A facing the light source LS1, and a side surface SS6A located on the opposite side of the side surface SS5A in the second direction Y and facing the reflector REF1.

[0087] As shown in FIG. 14, the optical waveguides 11R, 11G, and 11B formed in the distribution light-guiding element 10A are bent in the third direction Z (downward) near the end 11b. More specifically, the optical waveguides 11R, 11G, and 11B are bent downward at an angle θd (for example, 26.5°) with respect to the second direction Y in the YZ plane. The light emitted from the end 11b of the optical waveguides 11R, 11G, and 11B passes through the side surface SS6A and is reflected by the reflector REF1. The light reflected by the reflector REF1 travels toward the main surface MS2A of the distribution light-guiding element 10A, and its traveling direction is changed by the prism layer P1 provided on the main surface MS2A. The light whose traveling direction has been changed by the prism layer P1 is not in compliance with the total reflection condition of the main surface MS1A, and is emitted from the main surface MS1A. The light emitted from the main surface MS1A is converted by the prism sheet PS into light substantially parallel to the third direction Z, and then diffused by the diffusion sheet DS to illuminate the display panel PNL1. Although the illumination device ILD1 has been described as an example here, the illumination device ILD2 also has a similar structure.

[0088] The illumination device ILD according to the modification of the third embodiment described above can achieve the same effects as the third embodiment. Moreover, the illumination device ILD according to the modification of the third embodiment can achieve a structure having a smaller thickness (length in the third direction Z) than the illumination device ILD according to the third embodiment. The cross-sectional shape of the distribution light guide element 10A is not limited to the inverted wedge shape shown in FIG. 14, and may be rectangular, for example, as shown in FIG. 15.

[0089] (Fourth embodiment) Next, a fourth embodiment will be described. The illumination device ILD according to the fourth embodiment has a structure that combines the structure of the illumination device ILD according to the second embodiment with the structure of the illumination device ILD according to the modified example of the third embodiment. Specifically, the illumination device ILD according to the fourth embodiment has a structure that has a rectangular shape in a plan view and does not have a notch (nose cut), and a structure in which the distribution light guide element 10 and the light guide plate 20 are integrated.

[0090] FIG. 16 is a schematic plan view of an illumination device ILD according to the fourth embodiment. As shown in FIG. 16, the illumination device ILD includes light sources LS1 and LS2 and a light distribution guide element 10.

[0091] As shown in Fig. 16, the distribution light-guiding element 10 has a rectangular shape in a plan view, and has a side surface SS1 facing the light source LS1 and a side surface SS2 facing the light source LS2. The distribution light-guiding element 10 has a plurality of optical waveguides 11A1 extending from the side surface SS1 toward the side surface SS2 to near the center of the distribution light-guiding element 10, and a plurality of optical waveguides 11A2 extending from the side surface SS2 toward the side surface SS1 to near the center of the distribution light-guiding element 10. The plurality of optical waveguides 11A1 and 11A2 include optical waveguides 11R, 11G, and 11B, respectively. The plurality of optical waveguides 11A1 and 11A2 are spaced apart from each other near the center of the distribution light-guiding element 10.

[0092] Fig. 17 is a schematic cross-sectional view of an illumination device ILD according to a fourth embodiment. As shown in Fig. 17, in the distribution light-guiding element 10, the optical waveguides 11R, 11G, and 11B included in the optical waveguide 11A1 and the optical waveguides 11R, 11G, and 11B included in the optical waveguide 11A2 are formed in layers along the third direction Z.

[0093] As shown in FIG. 17, the distribution light-guiding element 10 has a side surface SS1 facing a light source LS1 and a The liquid crystal display panel has a side surface SS2 facing the display panel LS2, a main surface MS1 facing the display panels PNL1, PNL2, and a main surface MS2 located on the opposite side to the main surface MS1 in the third direction Z. A prism layer P including a plurality of prisms is provided on the main surface MS2.

[0094] The optical waveguides 11R, 11G, and 11B included in the optical waveguide 11A1 formed in the distribution light-guiding element 10 and the optical waveguides 11R, 11G, and 11B included in the optical waveguide 11A2 are bent in the third direction Z (downward) near the end portion 11b. More specifically, the optical waveguides 11R, 11G, and 11B included in the optical waveguide 11A1 and the optical waveguides 11R, 11G, and 11B included in the optical waveguide 11A2 are bent downward at an angle θd (for example, 26.5°) with respect to the first direction X in the XZ plane.

[0095] The light emitted from the ends 11b of the optical waveguides 11R, 11G, and 11B included in the optical waveguide 11A1 travels toward the principal surface MS2, and its traveling direction is changed by the prism layer P on the display panel PNL2 side (the right side in the figure) among the prism layers P provided on the principal surface MS2. The light whose traveling direction has been changed by the prism layer P deviates from the total reflection condition of the principal surface MS1, and is emitted from a region of the principal surface MS1 facing the display panel PNL2.

[0096] Furthermore, the light emitted from the ends 11b of the optical waveguides 11R, 11G, and 11B included in the optical waveguide 11A2 travels toward the principal surface MS2, and its traveling direction is changed by the prism layer P on the display panel PNL1 side (the left side in the figure) among the prism layers P provided on the principal surface MS2. The light whose traveling direction has been changed by the prism layer P deviates from the total reflection condition of the principal surface MS1, and is emitted from a region of the principal surface MS1 facing the display panel PNL1.

[0097] Both of the lights emitted from the main surface MS1 are converted by the prism sheet PS into lights substantially parallel to the third direction Z, and then diffused by the diffusion sheet DS to illuminate the display panels PNL1 and PNL2.

[0098] The illumination device ILD according to the fourth embodiment described above can achieve the same effects as those of the first embodiment described above, except that it does not support nose cuts. Moreover, the illumination device ILD according to the fourth embodiment does not need to stack a structure for illuminating the display panel PNL1 and a structure for illuminating the display panel PNL2 in the third direction Z as in the illumination device ILD according to the first to third embodiments, so it is possible to realize a structure having a smaller thickness (length in the third direction Z) than the illumination device ILD according to these embodiments.

[0099] According to at least one of the embodiments described above, it is possible to provide an illumination device ILD that can realize a reduction in the cost of the display device DSP as a head mounted display.

[0100] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0101] DSP... indicates a display device, PNL1, PNL2... indicate panels, ILD, ILD1, ILD2... indicate lighting devices, LS1, LS2, LSR, LSG, LSB... indicate light sources, 10A, 10B... indicate light distribution elements, 11, 11R, 11G, 11B, 11A1, 11A2... indicate optical waveguides, 11a, 11b... indicate ends, 20, 20A, 20B... indicate light guide plates, P, P1, P2... indicate prism layers, REF1, REF2... indicate reflectors.

Claims

1. A plurality of light sources; a distribution light-guiding element having a first side surface facing the plurality of light sources, a second side surface opposite to the first side surface, and a plurality of optical waveguides extending from the first side surface toward the second side surface; a light guide plate having a third side surface opposite to the second side surface and a first main surface; Equipped with Each of the plurality of optical waveguides has a first end portion to which light emitted from a corresponding light source is incident, and a second end portion from which light incident from the first end portion and propagating through the optical waveguide is emitted, the light emitted from the second end portion is incident on the light guide plate via the second side surface and the third side surface, propagates through the light guide plate, and is emitted from the first main surface. Lighting equipment.

2. the second side surface and the third side surface are parallel to each other, Each of the plurality of optical waveguides is bent in a thickness direction near the second end.

10. The lighting device of claim 1.

3. the third side surface is inclined with respect to the first main surface, The second side and the third side are not parallel to each other.

10. The lighting device of claim 1.

4. The plurality of light sources include a first light source that emits a red laser light, a second light source that emits a green laser light, and a third light source that emits a blue laser light. The lighting device according to claim 2 or 3.

5. the optical waveguide corresponding to the first light source, the optical waveguide corresponding to the second light source, and the optical waveguide corresponding to the third light source are arranged in a hierarchical manner in a thickness direction and do not intersect with each other; 5. The lighting device according to claim 4.

6. The light guide plate further has a second main surface opposite to the first main surface, and a prism layer provided on the second main surface.

10. The lighting device of claim 1.

7. A plurality of light sources; a distribution light-guiding element having a first side surface facing the plurality of light sources, a second side surface opposite to the first side surface, and a plurality of optical waveguides extending from the first side surface toward the second side surface; a light guide plate located above the distribution light guide element and having a first main surface and a third side surface overlapping the second side surface in a plan view; A reflector facing the second side surface and the third side surface; Equipped with Each of the plurality of optical waveguides has a first end portion to which light emitted from a corresponding light source is incident, and a second end portion from which light incident from the first end portion and propagating through the optical waveguide is emitted, the light emitted from the second end portion is reflected by the reflector, enters the light guide plate, propagates through the light guide plate, and is emitted from the first main surface. Lighting equipment.

8. Each of the plurality of optical waveguides is bent in a thickness direction near the second end.

8. An illumination device according to claim 7.

9. The plurality of light sources include a first light source that emits a red laser light, a second light source that emits a green laser light, and a third light source that emits a blue laser light.

9. The lighting device according to claim 7 or 8.

10. the optical waveguide corresponding to the first light source, the optical waveguide corresponding to the second light source, and the optical waveguide corresponding to the third light source are arranged in a hierarchical manner in a thickness direction and do not intersect with each other; 10. The lighting device according to claim 9.

11. The light guide plate further has a second main surface opposite to the first main surface, and a prism layer provided on the second main surface.

8. An illumination device according to claim 7.

12. A plurality of light sources; a distribution light-guiding element having a first side surface facing the plurality of light sources, a second side surface opposite to the first side surface, a first main surface, and a plurality of optical waveguides extending from the first side surface toward the second side surface; A reflector facing the second side surface; Equipped with Each of the plurality of optical waveguides has a first end portion to which light emitted from a corresponding light source is incident, and a second end portion from which light incident from the first end portion and propagating through the optical waveguide is emitted, The light emitted from the second end portion is reflected by the reflecting plate, propagates through the distribution light-guiding element, and is emitted from the first main surface. Lighting equipment.

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