Light receiving device and display device

Abstract

To provide a light receiving device having high light receiving efficiency, and a display device.SOLUTION: In a display device, a light receiving device includes: optical sensors 31, 32 having light receiving surfaces 31a, 32a, respectively; a light guide 34 having a first incidence surface 41a and a second incidence surface 42a on which a light ray is incident, a first emission surface 41b and a second emission surface 42b through which the light ray is emitted toward the respective light receiving surfaces, and a first boundary surface 41c and a second boundary surface 42c that direct the light ray incident from a side where the respective incidence surfaces are present toward the respective light receiving surfaces; a light emitting element 33 having a light emitting surface 33a to emit indicator light 21 when the display device is on standby and does not display a video; and a third incidence surface 43a and a third emission surface 43b.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to a light receiving device and a display device. [Background technology]

[0002] Patent Document 1 discloses a light receiving device. In the light receiving device, a remote control signal light is incident on an incident surface of a light guide. The incident remote control signal light is reflected and refracted inside the light guide. The reflected and refracted remote control signal light is emitted from an exit surface of the light guide. The emitted remote control signal light is received by a light receiving window of a light receiving sensor (paragraphs 0014, 0021, 0023 and 0025). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-164282 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the light receiving device disclosed in Patent Document 1, only remote control signal light that is incident within an area approximately the same size as the light receiving window can be guided to the light receiving window. Therefore, when the light guide is made thinner or the light receiving sensor is made smaller, the amount of remote control signal light that can be guided to the light receiving window decreases. This reduces the light receiving efficiency of the light receiving device.

[0005] The present disclosure has been made in view of this problem. An object of one aspect of the present disclosure is to provide, for example, a light receiving device having high light receiving efficiency. [Means for solving the problem]

[0006] A light receiving device of a first aspect of the present disclosure comprises an optical sensor having a light receiving surface, a light guide having an incident surface for receiving light rays, an exit surface for emitting the light rays toward the light receiving surface, and a boundary surface for directing the light rays incident from the side where the incident surface exists toward the exit surface.

[0007] A light receiving device according to a second aspect of the present disclosure includes the light receiving device according to the first aspect of the present disclosure and a display device main body to which the light receiving device is attached. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view illustrating a display device according to a first embodiment. [Diagram 2] 2 is a front view illustrating a schematic diagram of a light receiving device included in the display device of the first embodiment in a state where the light receiving device is not emitting indicator light. FIG. [Diagram 3] 2 is a front view illustrating a schematic state in which the light receiving device included in the display device of the first embodiment emits indicator light. FIG. [Figure 4] 1 is a perspective view illustrating a schematic diagram of a light receiving device provided in the display device of the first embodiment. [Diagram 5] 1 is a perspective view illustrating a schematic diagram of a light receiving device provided in the display device of the first embodiment. [Figure 6] 1 is a perspective view that diagrammatically illustrates a light guide provided in the display device of the first embodiment. [Figure 7] 2 is a cross-sectional view that illustrates a schematic diagram of a first optical sensor, a second optical sensor, a light-emitting element, a light guide, and a substrate that are provided in the display device of the first embodiment. FIG. [Figure 8] 2 is a cross-sectional view that typically illustrates a light guide and a substrate provided in the display device of the first embodiment. FIG. [Figure 9] 3 is a cross-sectional view illustrating a schematic state of a light guide and a substrate included in the display device of the first embodiment, in the process of fixing the substrate to the light guide. FIG. [Figure 10]3 is a cross-sectional view illustrating a schematic state of a light guide and a substrate included in the display device of the first embodiment, in the process of fixing the substrate to the light guide. FIG. [Figure 11] 1 is an image showing the trajectory of incident light rays contained in a remote control light that enters a light receiving device provided in a display device of the first embodiment, the distribution of the density of incident light rays that reach a first sensor, a second sensor, a light emitting element, and a substrate provided in the light receiving device, and the distribution of the density of incident light rays that reach the first sensor. [Figure 12] 10 is a front view diagrammatically illustrating a first optical sensor, a light-emitting element, and a substrate provided in a display device according to a second embodiment. FIG. [Figure 13] 10 is a top view diagrammatically illustrating a first optical sensor, a light emitting element, a light guide, and a substrate provided in a display device according to a second embodiment. FIG. [Figure 14] FIG. 11 is a front view illustrating a first optical sensor, a light-emitting element, and a substrate provided in a display device according to a third embodiment. [Figure 15] 13 is a top view diagrammatically illustrating a first optical sensor, a light emitting element, a light guide, and a substrate provided in a display device according to a third embodiment. FIG. [Figure 16] 13 is a side view diagrammatically illustrating a first optical sensor, a light emitting element, a light guide, and a substrate provided in a display device according to a third embodiment. FIG. [Figure 17] FIG. 13 is a bottom view diagrammatically illustrating a light receiving device provided in a display device according to a fourth embodiment. [Figure 18] FIG. 13 is a perspective view that illustrates a light receiving device provided in a display device according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or equivalent elements are denoted by the same reference numerals, and duplicated descriptions will be omitted.

[0010] 1. First embodiment 1.1 Display device FIG. 1 is a perspective view that diagrammatically illustrates a display device according to a first embodiment.

[0011] The display device 1 of the first embodiment illustrated in Fig. 1 is a television receiver. The display device 1 may be a display device other than a television receiver. For example, the display device 1 may be a monitor-integrated personal computer, a monitor for a personal computer, digital signage, etc.

[0012] The display device 1 displays video and outputs audio.

[0013] The display device 1 receives remote control light coming from a remote controller (hereinafter, referred to as a "remote control") and operates according to the received remote control light. For example, the display device 1 turns on when the received remote control light is remote control light that instructs the display device 1 to be turned on. The display device 1 goes into standby when the received remote control light is remote control light that instructs the display device 1 to be in standby. The display device 1 changes the selected channel when the received remote control light is remote control light that instructs the display device 1 to change the selected channel. The display device 1 changes the volume of the output audio when the received remote control light is remote control light that instructs the display device 1 to change the selected input source.

[0014] The display device 1 receives ambient light coming from the environment in which the display device 1 is installed, and adjusts the image to be displayed according to the received ambient light. For example, the display device 1 adjusts the brightness of the image to be displayed according to the brightness of the received ambient light, and adjusts the color temperature of the image to be displayed according to the color temperature of the received ambient light.

[0015] As shown in FIG. 1, the display device 1 includes a display device main body 11, a stand 12, and a light receiving device 13.

[0016] The display device main body 11 has a rectangular plate-like shape. Therefore, the display device main body 11 has a front surface 11a and a bottom surface 11b. The front surface 11a is disposed on the front side of the display device 1 in the depth direction DD and faces forward in the depth direction DD. The bottom surface 11b is disposed on the lower side of the display device 1 in the height direction DH and faces downward in the height direction DH. The display device main body 11 displays images on the front surface 11a and outputs audio from the bottom surface 11b.

[0017] The stand 12 supports the display device main body 11 .

[0018] The light receiving device 13 receives the remote control light and transmits a signal corresponding to the received remote control light to the display device main body 11. The display device main body 11 receives the transmitted signal from the light receiving device 13 and operates according to the received signal. As a result, the display device main body 11 operates according to the remote control light received by the light receiving device 13.

[0019] The light receiving device 13 receives ambient light and transmits a signal corresponding to the received ambient light to the display device main body 11. The display device main body 11 receives the transmitted signal from the light receiving device 13 and adjusts the image to be displayed according to the received signal. In this way, the display device main body 11 adjusts the image to be displayed according to the ambient light received by the light receiving device 13.

[0020] The display device main body 11 transmits a signal indicating that the display device main body 11 is on standby to the light receiving device 13. When the light receiving device 13 receives the transmitted signal from the display device main body 11, it emits an indicator light.

[0021] The light receiving device 13 is attached to the center of the bottom surface 11b of the display device main body 11 and is laid out directly below the center of the bottom surface 11b. The light receiving device 13 may be laid out in a location other than directly below the center of the bottom surface 11b. For example, the light receiving device 13 may be laid out directly below the left end of the bottom surface 11b, directly below the right end of the bottom surface 11b, inside the bottom bezel of the display device main body 11, etc.

[0022] 1.2 Indicator Light Fig. 2 is a front view showing a state where the light receiving device provided in the display device of the first embodiment is not emitting indicator light, and Fig. 3 is a front view showing a state where the light receiving device provided in the display device of the first embodiment is emitting indicator light.

[0023] When the display device 1 is turned on and displays an image, the light receiving device 13 is turned off and does not emit indicator light, as shown in Fig. 2. This makes it possible to suppress the influence of the indicator light on the detection of ambient light when the display device 1 is turned on.

[0024] When the display device 1 is in standby and not displaying an image, as shown in Fig. 3, the light receiving device 13 is turned on and emits an indicator light 21. The emitted indicator light 21 is, for example, a red light. The indicator light 21 may be a light other than red light.

[0025] 1.3 Photodetector Fig. 4 and Fig. 5 are perspective views that typically illustrate a light receiving device provided in the display device of the first embodiment, and Fig. 6 is a perspective view that typically illustrates a light guide provided in the display device of the first embodiment.

[0026] 4 to 6, the light receiving device 13 includes a first light sensor 31, a second light sensor 32, a light emitting element 33, a light guide 34, and a substrate 35. The light guide 34 includes a first lens 41, a second lens 42, and a third lens 43.

[0027] The first optical sensor 31 detects the remote control light.

[0028] The second light sensor 32 detects ambient light.

[0029] The light-emitting element 33 emits the indicator light 21 when the display device 1 is in standby and not displaying an image. The emitted indicator light 21 is red light. Therefore, the light-emitting element 33 is a red light-emitting element. The light-emitting element 33 is, for example, a light-emitting diode.

[0030] The light guide 34 guides the remote control light and the ambient light from the outside of the light receiving device 13 to the first light sensor 31 and the second light sensor 32, respectively, and guides the indicator light 21 from the light emitting element 33 to the outside of the light receiving device 13. The light guide 34 is made of a transparent body, for example, made of resin.

[0031] The substrate 35 supports the first light sensor 31 , the second light sensor 32 and the light emitting element 33 .

[0032] The first lens 41 has a first incident surface 41a and a first exit surface 41b. The first optical sensor 31 has a first light receiving surface 31a. The first incident surface 41a is disposed on the front side in the depth direction DD and can be viewed from the front in the depth direction DD. The first exit surface 41b is disposed on the rear side in the depth direction DD and faces the rear in the depth direction DD. The first light receiving surface 31a is disposed behind the first exit surface 41b in the depth direction DD, faces the front in the depth direction DD, and faces the first exit surface 41b. Thereby, the first incident surface 41a makes the remote control light enter. The first lens 41 guides the incident remote control light from the first incident surface 41a to the first exit surface 41b. The first exit surface 41b emits the guided remote control light. The first light receiving surface 31a receives the emitted remote control light. As a result, the first lens 41 guides the incident remote control light to the first optical sensor 31. The first optical sensor 31 outputs a signal corresponding to the remote control light received by the first light receiving surface 31a. The incident remote control light includes infrared light. The first optical sensor 31 outputs a signal corresponding to the infrared light received by the first light receiving surface 31a.

[0033] The second lens 42 has a second incident surface 42a and a second exit surface 42b. The second optical sensor 32 has a second light receiving surface 32a. The second incident surface 42a is disposed on the front side in the depth direction DD and can be viewed from the front in the depth direction DD. The second exit surface 42b is disposed on the rear side in the depth direction DD and faces the rear in the depth direction DD. The second light receiving surface 32a is disposed rearward of the second exit surface 42b in the depth direction DD, faces the front in the depth direction DD, and faces the second exit surface 42b. Thereby, the second incident surface 42a makes the ambient light enter. The second lens 42 guides the incident ambient light from the second incident surface 42a to the second exit surface 42b. The second exit surface 42b emits the guided ambient light. The second light receiving surface 32a receives the emitted ambient light. As a result, the second lens 42 guides the incident ambient light to the second optical sensor 32. The second optical sensor 32 outputs a signal corresponding to the ambient light received by the second light receiving surface 32a. The incident ambient light includes visible light. The second optical sensor 32 outputs a signal corresponding to the visible light received by the second light receiving surface 32a.

[0034] The light-emitting element 33 has a light-emitting surface 33a. The third lens 43 has a third incident surface 43a and a third exit surface 43b. The light-emitting surface 33a faces forward in the depth direction DD and emits indicator light 21. The third incident surface 43a is disposed on the rear side in the depth direction DD, faces backward in the depth direction DD, and faces the light-emitting surface 33a. The third exit surface 43b is disposed on the front side in the depth direction DD and can be viewed from the front in the depth direction DD. Thereby, the third incident surface 43a causes the emitted indicator light 21 to enter. The third lens 43 guides the incident indicator light 21 from the third incident surface 43a to the third exit surface 43b. The third exit surface 43b causes the guided indicator light 21 to exit.

[0035] The first optical sensor 31, the second optical sensor 32, and the light-emitting element 33 are arranged in a line in the width direction DW of the display device 1. The first optical sensor 31 is disposed on the left side of the width direction DW when viewed from the front side of the depth direction DD. The second optical sensor 32 is disposed on the right side of the width direction DW when viewed from the front side of the depth direction DD. The light-emitting element 33 is disposed in the center of the width direction DW when viewed from the front side of the depth direction DD. Therefore, the second optical sensor 32 and the light-emitting element 33 are close to each other. Therefore, the second optical sensor 32 receives a part of the indicator light 21 emitted by the light-emitting element 33. However, during a period when the display device 1 is turned on and the signal output by the second optical sensor 32 is used for adjusting the image, the light-emitting element 33 does not emit the indicator light 21. This makes it possible to suppress the indicator light 21 from affecting the adjustment of the image. This effect is particularly noticeable when the light-receiving device 13 is miniaturized or simplified to increase the amount of indicator light 21 received by the second optical sensor 32.

[0036] 1.4 Optical system for remote control light FIG. 7 is a cross-sectional view that typically illustrates the first optical sensor, the second optical sensor, the light-emitting element, the light guide, and the substrate that are provided in the display device of the first embodiment.

[0037] 7, the first optical sensor 31 has a first optical axis 31b. The first optical sensor 31 has directivity symmetrical about the first optical axis 31b. The sensitivity of the first optical sensor 31 is maximum, for example, in the direction in which the first optical axis 31b extends. The first optical axis 31b is perpendicular to the first light receiving surface 31a and passes through the center of the first light receiving surface 31a.

[0038] The first entrance surface 41 a includes a flat surface 61 , a flat surface 62 and a convex curved surface 63 .

[0039] The flat surface 61 allows the incident light ray L11 included in the remote control light to be incident thereon. The flat surface 61 is flat. The flat surface 61 is perpendicular to the first optical axis 31b. The flat surface 61 is disposed in an area on the first light receiving surface 31a. Therefore, the first optical axis 31b passes through the flat surface 61.

[0040] The flat surface 62 allows the incident light ray L12 contained in the remote control light to be incident thereon. The flat surface 62 is flat. The flat surface 62 is adjacent to the flat surface 61. The flat surface 62 and the flat surface 61 form the same plane. The flat surface 62 is disposed outside the area on the first light receiving surface 31a. The flat surface 62 is disposed shifted to the right in the width direction DW from the area on the first light receiving surface 31a when viewed from the front side in the depth direction DD. The flat surface 62 is perpendicular to the first optical axis 31b.

[0041] The convex curved surface 63 allows the incident light beams L13 and L14 included in the remote control light to enter. The convex curved surface 63 is curved convexly and has an R shape. Therefore, the convex curved surface 63 has positive power. Therefore, the convex curved surface 63 condenses the incident light beams. The convex curved surface 63 is adjacent to the flat surface 61. The convex curved surface 63 is disposed outside the area on the first light receiving surface 31a. The convex curved surface 63 is disposed shifted to the left in the width direction DW from the area on the first light receiving surface 31a when viewed from the front side in the depth direction DD. The convex curved surface 63 is perpendicular to the first optical axis 31b at the right end portion close to the flat surface 61 and smoothly connected to the flat surface 61. The convex curved surface 63 is parallel to the first optical axis 31b at the left end portion opposite to the right end portion close to the flat surface 61.

[0042] The first exit surface 41b emits the incident light beams L11, L12, L13, and L14. The first exit surface 41b is flat. The first exit surface 41b is disposed in an area on the first light receiving surface 31a. Therefore, the first optical axis 31b passes through the first exit surface 41b.

[0043] The first lens 41 has a first boundary surface 41c.

[0044] The first boundary surface 41c is disposed outside the area on the first light receiving surface 31a. The first boundary surface 41c is disposed shifted to the right in the width direction DW from the area on the first light receiving surface 31a when viewed from the front side in the depth direction DD. The first boundary surface 41c extends from the front side where the first incident surface 41a exists to the rear side where the first exit surface 41b exists. The first boundary surface 41c is an inclined surface inclined from a direction parallel to the first optical axis 31b, faces a direction intermediate between the right side in the width direction DW and the rear in the depth direction DD, and approaches the first optical axis 31b as it proceeds from the front side where the first incident surface 41a exists to the rear side where the first exit surface 41b exists.

[0045] When the incident light ray L11 travels in a direction parallel to the first optical axis 31b until it enters the first lens 41, the flat surface 61 transmits the incident light ray L11 toward the first exit surface 41b. The transmitted incident light ray L11 travels inside the first lens 41 and reaches the first exit surface 41b. The first exit surface 41b emits the incident light ray L11 that has reached it toward the first light receiving surface 31a. The first light receiving surface 31a receives the emitted incident light ray L11. When the incident light ray L11 travels inside the first lens 41, it travels through the area on the first light receiving surface 31a. Therefore, the incident light ray L11 does not reach the first boundary surface 41c that is disposed outside the area on the first light receiving surface 31a. Therefore, the first boundary surface 41c does not prevent the first light receiving surface 31a from receiving the incident light ray L11.

[0046] When the incident light L12 travels in a direction parallel to the first optical axis 31b until it enters the first lens 41, the flat surface 62 transmits the incident light L12 toward the first boundary surface 41c. The transmitted incident light L12 travels inside the first lens 41 and reaches the first boundary surface 41c. The first boundary surface 41c totally reflects the incident light L12 that has reached it toward the first exit surface 41b. The totally reflected incident light L12 travels inside the first lens 41 and reaches the first exit surface 41b. The first boundary surface 41c may reflect or diffuse the incident light L12 that has reached it toward the first exit surface 41b. The reflected or diffused incident light L12 may travel inside the first lens 41 and reach the first exit surface 41b. The first light exit surface 41b emits the incident light L12 that has reached it toward the first light receiving surface 31a. The first light receiving surface 31a receives the emitted incident light L12. Therefore, the first boundary surface 41c increases the amount of incident light received by the first light receiving surface 31a, and increases the light receiving efficiency of the light receiving device 13.

[0047] When the incident light beams L13 and L14 travel in a direction parallel to the first optical axis 31b until they enter the first lens 41, the convex curved surface 63 refracts the incident light beams L13 and L14 toward the first exit surface 41b and the first boundary surface 41c, respectively. The incident light beam L13 refracted toward the first exit surface 41b travels through the first lens 41 and reaches the first exit surface 41b. The first exit surface 41b emits the incident light beam L13 that has arrived toward the first light receiving surface 31a. The first light receiving surface 31a receives the emitted incident light beam L13. The incident light beam L14 refracted toward the first boundary surface 41c travels through the first lens 41 and reaches the first boundary surface 41c. The first boundary surface 41c totally reflects the incident light L14 that has arrived thereto toward the first exit surface 41b. The totally reflected incident light L14 travels through the first lens 41 and reaches the first exit surface 41b. The first boundary surface 41c may reflect or diffuse the incident light L14 that has arrived thereto toward the first exit surface 41b. The reflected or diffused incident light L14 may travel through the first lens 41 and reach the first exit surface 41b. The first exit surface 41b emits the incident light L14 that has arrived thereto toward the first light receiving surface 31a. The first light receiving surface 31a receives the emitted incident light L14. Therefore, the convex curved surface 63 increases the amount of incident light received by the first light receiving surface 31a, thereby increasing the light receiving efficiency of the light receiving device 13.

[0048] Overall, the first boundary surface 41c totally reflects the first light ray consisting of the incident light rays L12 and L14 contained in the remote control light toward the first exit surface 41b, thereby increasing the amount of incident light received by the first light receiving surface 31a and improving the light receiving efficiency of the light receiving device 13.

[0049] In the following, the width of the first incident surface 41a in the width direction DW is referred to as width W1, the width of the first light receiving surface 31a and the flat surface 61 in the width direction DW is referred to as width W11, the width of the first boundary surface 41c and the flat surface 62 in the width direction DW is referred to as width W12, and the width of the convex curved surface 63 in the width direction DW is referred to as width W13.

[0050] The width W12 of the flat surface 62 is preferably about one time the width W11 of the first light receiving surface 31a.

[0051] The width W13 of the convex curved surface 63 is preferably about twice the width W11 of the first light receiving surface 31a. If the width W13 is significantly smaller than about twice the width W11, the number of incident light rays entering the convex curved surface 63 decreases, and the number of light rays focused on the first light receiving surface 31a tends to decrease. If the width W13 is significantly smaller than about twice the width W11, the position of the focal point of the convex curved surface 63 approaches the convex curved surface 63, and the number of light rays focused on the first light receiving surface 31a tends to decrease. On the other hand, if the width W13 is significantly larger than about twice the width W11, the convex curved surface 63 does not focus the incident light rays sufficiently, and the number of light rays focused on the first light receiving surface 31a tends to decrease.

[0052] When the width W12 of the flat surface 62 is approximately one time the width W11 of the first light receiving surface 31a, and the width W13 of the convex curved surface 63 is approximately two times the width W11 of the first light receiving surface 31a, the first lens 41 can condense the incident light beam incident on the first entrance surface 41a having a width W1 approximately four times the width W11 of the first light receiving surface 31a onto the first light receiving surface 31a. This can increase the light receiving efficiency of the light receiving device 13. These effects can be confirmed by ray tracing simulations, measuring the reach of remote control light in an actual device, and the like. Increasing the light receiving efficiency of the light receiving device 13 contributes to miniaturizing the light receiving device 13, lengthening the reach of remote control light, miniaturizing the first optical sensor 31, thinning the light guide 34, and the like.

[0053] The amount of incident light condensed on the first light receiving surface 31a varies in a complex manner depending on factors such as the position of the first boundary surface 41c, the width W13 of the convex curved surface 63, the distance from the first entrance surface 41a to the first light receiving surface 31a, etc. For this reason, in the light receiving device 13, these factors are adjusted in a balanced manner.

[0054] 1.5 Optical system for ambient light 7, the second optical sensor 32 has a second optical axis 32b. The second optical sensor 32 has directivity symmetrical with respect to the second optical axis 32b. The sensitivity of the second optical sensor 32 is maximum, for example, in the direction in which the second optical axis 32b extends. The second optical axis 32b is perpendicular to the second light receiving surface 32a and passes through the center of the second light receiving surface 32a.

[0055] As shown in FIG. 7, the second entrance surface 42 a includes a flat surface 71 , a flat surface 72 and a convex curved surface 73 .

[0056] The flat surface 71 allows incident light ray L21 contained in ambient light to enter. The flat surface 71 is flat. The flat surface 71 is perpendicular to the second optical axis 32b. The flat surface 71 is disposed in an area on the second light receiving surface 32a. Therefore, the second optical axis 32b passes through the flat surface 71.

[0057] The flat surface 72 allows incident light rays L22 contained in ambient light to be incident thereon. The flat surface 72 is flat. The flat surface 72 is adjacent to the flat surface 71. The flat surface 72 and the flat surface 71 form the same plane. The flat surface 72 is disposed outside the area on the second light receiving surface 32a. The flat surface 72 is disposed shifted to the left in the width direction DW from the area on the second light receiving surface 32a when viewed from the front side in the depth direction DD. The flat surface 72 is perpendicular to the second optical axis 32b.

[0058] The convex curved surface 73 allows the incident light rays L23 and L24 contained in the ambient light to enter. The convex curved surface 73 is curved convexly and has an R shape. Therefore, the convex curved surface 73 has a positive power. Therefore, the convex curved surface 73 condenses the incident light rays. The convex curved surface 73 is adjacent to the flat surface 71. The convex curved surface 73 is disposed outside the area on the second light receiving surface 32a. The convex curved surface 73 is disposed shifted to the right in the width direction DW from the area on the second light receiving surface 32a when viewed from the front side in the depth direction DD. The convex curved surface 73 is perpendicular to the second optical axis 32b at the left end portion close to the flat surface 71 and smoothly connected to the flat surface 71. The convex curved surface 73 is parallel to the second optical axis 32b at the right end portion opposite to the left end portion close to the flat surface 71.

[0059] The second exit surface 42b emits the incident light beams L21, L22, L23, and L24. The second exit surface 42b is flat. The second exit surface 42b is disposed in an area on the second light receiving surface 32a. Therefore, the second optical axis 32b passes through the second exit surface 42b.

[0060] The second lens 42 has a second interface surface 42c.

[0061] The second boundary surface 42c is disposed outside the area on the second light receiving surface 32a. The second boundary surface 42c is disposed shifted to the left in the width direction DW from the area on the second light receiving surface 32a when viewed from the front side in the depth direction DD. The second boundary surface 42c extends from the front side where the second incident surface 42a exists to the rear side where the second exit surface 42b exists. The second boundary surface 42c is an inclined surface inclined from a direction parallel to the second optical axis 32b, faces a direction intermediate between the left side in the width direction DW and the rear in the depth direction DD, and approaches the second optical axis 32b as it proceeds from the front side where the second incident surface 42a exists to the rear side where the second exit surface 42b exists.

[0062] When the incident light ray L21 travels in a direction parallel to the second optical axis 32b until it enters the second lens 42, the flat surface 71 transmits the incident light ray L21 toward the second exit surface 42b. The transmitted incident light ray L21 travels through the second lens 42 and reaches the second exit surface 42b. The second exit surface 42b emits the incident light ray L21 that has reached it toward the second light receiving surface 32a. The second light receiving surface 32a receives the emitted incident light ray L21. When the incident light ray L21 travels through the second lens 42, it travels through the area on the second light receiving surface 32a. Therefore, the incident light ray L21 does not reach the second boundary surface 42c that is disposed outside the area on the second light receiving surface 32a. Therefore, the second boundary surface 42c does not prevent the second light receiving surface 32a from receiving the incident light ray L21.

[0063] When the incident light ray L22 travels in a direction parallel to the second optical axis 32b until it enters the second lens 42, the flat surface 72 transmits the incident light ray L22 toward the second boundary surface 42c. The transmitted incident light ray L22 travels through the second lens 42 and reaches the second boundary surface 42c. The second boundary surface 42c totally reflects the incident light ray L22 toward the second exit surface 42b. The totally reflected incident light ray L22 travels through the second lens 42 and reaches the second exit surface 42b. The second boundary surface 42c may reflect or diffuse the incident light ray L22 toward the second exit surface 42b. The reflected or diffused incident light ray L22 may travel through the second lens 42 and reach the second exit surface 42b. The second light exit surface 42b emits the incident light L22 that has reached it toward the second light receiving surface 32a. The second light receiving surface 32a receives the emitted incident light L22. Therefore, the second boundary surface 42c increases the amount of incident light received by the second light receiving surface 32a, thereby increasing the light receiving efficiency of the light receiving device 13.

[0064] When the incident light beams L23 and L24 travel in a direction parallel to the second optical axis 32b until they enter the second lens 42, the convex curved surface 73 refracts the incident light beams L23 and L24 toward the second exit surface 42b and the second boundary surface 42c, respectively. The incident light beam L23 refracted toward the second exit surface 42b travels through the second lens 42 and reaches the second exit surface 42b. The second exit surface 42b emits the incident light beam L23 that has arrived toward the second light receiving surface 32a. The second light receiving surface 32a receives the emitted incident light beam L23. The incident light beam L24 refracted toward the second boundary surface 42c travels through the second lens 42 and reaches the second boundary surface 42c. The second boundary surface 42c totally reflects the incident light L24 that has arrived thereto toward the second exit surface 42b. The totally reflected incident light L24 travels through the second lens 42 and reaches the second exit surface 42b. The second boundary surface 42c may reflect or diffuse the incident light L24 that has arrived thereto toward the second exit surface 42b. The reflected or diffused incident light L24 travels through the second lens 42 and reaches the second exit surface 42b. The second exit surface 42b emits the incident light L24 that has arrived thereto toward the second light receiving surface 32a. The second light receiving surface 32a receives the emitted incident light L24. Therefore, the convex curved surface 73 increases the amount of incident light received by the second light receiving surface 32a, thereby increasing the light receiving efficiency of the light receiving device 13.

[0065] Overall, the second boundary surface 42c totally reflects the second light ray consisting of incident light rays L22 and L24 contained in the ambient light toward the second exit surface 42b, thereby increasing the amount of incident light received by the second light receiving surface 32a and improving the light receiving efficiency of the light receiving device 13.

[0066] In the following, the width of the second incident surface 42a in the width direction DW is referred to as width W2, the width of the second light receiving surface 32a and the flat surface 71 in the width direction DW is referred to as width W21, the width of the second boundary surface 42c and the flat surface 72 in the width direction DW is referred to as width W22, and the width of the convex curved surface 73 in the width direction DW is referred to as width W23.

[0067] The width W22 of the flat surface 72 is preferably about one time the width W21 of the second light receiving surface 32a.

[0068] The width W23 of the convex curved surface 73 is preferably about twice the width W21 of the second light receiving surface 32a for the same reason as the width W13 of the convex curved surface 63 is preferably about twice the width W11 of the first light receiving surface 31a.

[0069] When the width W22 of the flat surface 72 is approximately one time the width W21 of the second light receiving surface 32a, and the width W23 of the convex curved surface 73 is approximately two times the width W21 of the second light receiving surface 32a, the second lens 42 can condense the incident light beam incident on the second entrance surface 42a having a width W2 approximately four times the width W21 of the second light receiving surface 32a onto the second light receiving surface 32a. This can increase the light receiving efficiency of the light receiving device 13. These effects can be confirmed by ray tracing simulations, measurements of the reach of remote control light in an actual device, and the like. Increasing the light receiving efficiency of the light receiving device 13 contributes to miniaturizing the light receiving device 13, miniaturizing the second optical sensor 32, thinning the light guide 34, and the like.

[0070] The amount of incident light condensed on the second light receiving surface 32a varies in a complex manner depending on factors such as the position of the second boundary surface 42c, the width W23 of the convex curved surface 73, the distance from the second entrance surface 42a to the second light receiving surface 32a, etc. For this reason, in the light receiving device 13, these factors are adjusted in a balanced manner.

[0071] 1.6 Optics for indicator lights 7, the light-emitting element 33 has a third optical axis 33b. The light-emitting element 33 has directivity symmetrical with respect to the third optical axis 33b. The light-emitting intensity of the light-emitting element 33 is maximum, for example, in the direction in which the third optical axis 33b extends. The third optical axis 33b is perpendicular to the light-emitting surface 33a and passes through the center of the light-emitting surface 33a.

[0072] The third incident surface 43a allows the exiting light beams L31, L32, and L33 included in the indicator light 21 to enter. The exiting light beam L31 travels in a direction parallel to the third optical axis 33b. The exiting light beam L32 travels in a direction inclined to the left in the width direction DW from a direction parallel to the third optical axis 33b. The exiting light beam L33 travels in a direction inclined to the right in the width direction DW from a direction parallel to the third optical axis 33b. The third incident surface 43a is flat. The third incident surface 43a is perpendicular to the third optical axis 33b. The third incident surface 43a is disposed in an area including an area on the light emitting surface 33a. Therefore, the third optical axis 33b passes through the third incident surface 43a.

[0073] The third exit surface 43b emits the exiting light beams L31, L32, and L33. The third exit surface 43b is flat. The third exit surface 43b is perpendicular to the third optical axis 33b. The third exit surface 43b is disposed in an area including an area on the light emitting surface 33a. Therefore, the third optical axis 33b passes through the third exit surface 43b.

[0074] As shown in FIG. 7, the third lens 43 has third boundary surfaces 43c1 and 43c2.

[0075] The third boundary surface 43c1 is disposed outside the region on the light-emitting surface 33a. The third boundary surface 43c1 is disposed shifted to the left in the width direction DW from the region on the light-emitting surface 33a when viewed from the front side in the depth direction DD. The third boundary surface 43c1 extends from the front side where the third emission surface 43b exists to the rear side where the third incidence surface 43a exists. The third boundary surface 43c1 is an inclined surface inclined from a direction parallel to the third optical axis 33b, faces a direction intermediate between the left side in the width direction DW and the rear in the depth direction DD, and approaches the third optical axis 33b as it proceeds from the front side where the third emission surface 43b exists to the rear side where the third incidence surface 43a exists.

[0076] The third boundary surface 43c2 is disposed outside the region on the light-emitting surface 33a. The third boundary surface 43c2 is disposed shifted to the right in the width direction DW from the region on the light-emitting surface 33a when viewed from the front side in the depth direction DD. The third boundary surface 43c2 extends from the front side where the third emission surface 43b exists to the rear side where the third incidence surface 43a exists. The third boundary surface 43c2 is an inclined surface inclined from a direction parallel to the third optical axis 33b, faces a direction intermediate between the right side in the width direction DW and the rear in the depth direction DD, and approaches the third optical axis 33b as it proceeds from the front side where the third emission surface 43b exists to the rear side where the third incidence surface 43a exists.

[0077] The third entrance surface 43a transmits the output light ray L31 toward the third exit surface 43b. The transmitted output light ray L31 travels through the third lens 43 and reaches the third exit surface 43b. The third exit surface 43b emits the output light ray L31 that has reached it.

[0078] The third entrance surface 43a transmits the output light ray L32 toward the third boundary surface 43c1. The transmitted output light ray L32 travels through the third lens 43 and reaches the third boundary surface 43c1. The third boundary surface 43c1 totally reflects the output light ray L32 that has reached it toward the third output surface 43b. The totally reflected output light ray L32 travels through the third lens 43 and reaches the third output surface 43b. The third output surface 43b emits the output light ray L32 that has reached it. The third boundary surface 43c1 may reflect or diffuse the output light ray L32 that has reached it toward the third output surface 43b. The reflected or diffused output light ray L32 may travel through the third lens 43 and reach the third output surface 43b.

[0079] The third entrance surface 43a transmits the output light ray L33 toward the third boundary surface 43c2. The transmitted output light ray L33 travels through the third lens 43 and reaches the third boundary surface 43c2. The third boundary surface 43c2 totally reflects the output light ray L32 that has reached it toward the third output surface 43b. The totally reflected output light ray L33 travels through the third lens 43 and reaches the third output surface 43b. The third boundary surface 43c2 may reflect or diffuse the output light ray L32 that has reached it toward the third output surface 43b. The reflected or diffused output light ray L33 may travel through the third lens 43 and reach the third output surface 43b. The third output surface 43b emits the output light ray L33 that has reached it.

[0080] Overall, the third boundary surfaces 43c1 and 43c2 totally reflect the third light ray consisting of the output light rays L32 and L33 included in the indicator light 21 emitted by the light emitting element 33 toward the third output surface 43b.

[0081] 1.7 Forming slits in the light guide As shown in FIGS. 5 to 7, the light guide 34 has a first slit 81 and a second slit 82 formed therein.

[0082] The light guide 34 has a plate-like shape. Therefore, the light guide 34 has a main surface 34a and a main surface 34b. The main surface 34a is disposed on the upper side in the height direction DH. The main surface 34b is disposed on the lower side in the height direction DH. The first slits 81 and the second slits 82 are formed in the main surface 34a. The first slits 81 and the second slits 82 have a groove-like shape. The first slits 81 and the second slits 82 may be formed in the main surface 34b, or may be formed in a distributed manner on the main surface 34a and the main surface 34b.

[0083] The first slit 81 is formed between the first lens 41 and the third lens 43. The second slit 82 is formed between the second lens 42 and the third lens 43.

[0084] The first boundary surface 41c and the third boundary surface 43c1 face the first slit 81. The first boundary surface 41c and the third boundary surface 43c1 sandwich the first slit 81 from the left and right in the width direction DW and form inner surfaces of the first slit 81.

[0085] The second boundary surface 42c and the third boundary surface 43c2 face the second slit 82. The second boundary surface 42c and the third boundary surface 43c2 sandwich the second slit 82 from the right and left in the width direction DW and form inner surfaces of the second slit 82.

[0086] 1.8 Fixing the substrate to the light guide As shown in Figures 5 and 7, the substrate 35 has a first major surface 35a and a second major surface 35b.

[0087] The first main surface 35a and the second main surface 35b are on opposite sides to each other. The first main surface 35a is disposed on the front side in the depth direction DD and faces forward in the depth direction DD. The first optical sensor 31, the second optical sensor 32, and the light-emitting element 33 are mounted on the first main surface 35a. The second main surface 35b is disposed on the rear side in the depth direction DD and faces backward in the depth direction DD.

[0088] FIG. 8 is a cross-sectional view that typically illustrates a light guide and a substrate provided in the display device of the first embodiment.

[0089] 8, the substrate 35 has a rectangular plate shape, and therefore has a first end face 35c, a second end face 35d, a third end face 35e, and a fourth end face 35f.

[0090] The first end face 35c and the second end face 35d are on opposite sides to each other. The third end face 35e and the fourth end face 35f are on opposite sides to each other. The first end face 35c faces the first direction D1. The second end face 35d faces the second direction D2 opposite to the first direction D1. The third end face 35e faces the third direction D3 intersecting with the first direction D1 and the second direction D2. The fourth end face 35f faces the fourth direction D4 intersecting with the first direction D1 and the second direction D2 and opposite to the third direction D3. The third direction D3 and the fourth direction D4 are perpendicular to the first direction D1 and the second direction D2. A protrusion 91 is formed on the third end face 35e.

[0091] A hole 34h is formed in the light guide 34. Therefore, the light guide 34 has an inner bottom surface 34c facing the hole 34h. The inner bottom surface 34c faces upward in the height direction DH.

[0092] As shown in FIGS. 5, 6 and 8, the light guide 34 includes a stopper 101 and a hook 102. As shown in FIG.

[0093] The stopper 101 has a hook-like shape. The stopper 101 is spaced a first distance above the inner bottom surface 34c in the height direction DH. The hook 102 is spaced a second distance above the inner bottom surface 34c in the height direction DH that is longer than the first distance.

[0094] The substrate 35 is accommodated in the hole 34h. When the substrate 35 is accommodated in the hole 34h, the first end surface 35c abuts against the inner bottom surface 34c. This restricts the substrate 35 from moving downward in the height direction DH.

[0095] Furthermore, when the substrate 35 is accommodated in the hole 34h, the protrusion 91 abuts against the stopper 101 from behind in the depth direction DD, and the protrusion 91 abuts against the stopper 101 from below in the height direction DH. This restricts the substrate 35 from moving upward in the height direction DH and forward in the depth direction DD.

[0096] Furthermore, when the substrate 35 is accommodated in the hole 34h, the second main surface 35b abuts against the hook 102 from the front in the depth direction DD, and the second end surface 35d abuts against the hook 102 from below in the height direction DH. This restricts the substrate 35 from moving upward in the height direction DH and backward in the depth direction DD.

[0097] As a result, the substrate 35 is fixed to the light guide 34 .

[0098] 9 and 10 are cross-sectional views that typically illustrate a light guide and a substrate provided in the display device of the first embodiment, in a state in which the substrate is being fixed to the light guide.

[0099] When the substrate 35 is fixed to the light guide 34, the hook 102 is elastically deformed toward the rear in the depth direction DD. As shown in FIG. 9, the substrate 35 is inserted into the hole 34h in a tilted state so that the protrusion 91 is located lower in the height direction DH than the stopper 101. As shown in FIG. 10 and FIG. 8, the substrate 35 is rotated until the first end face 35c abuts on the inner bottom face 34c. When the substrate 35 is rotated until the first end face 35c abuts on the inner bottom face 34c, the elastically deformed hook 102 returns to its original position. This fixes the substrate 35 to the light guide 34.

[0100] 1.9 Simulation Figure 11 is an image showing the trajectory of incident light rays contained in remote control light that enters a light receiving device provided in the display device of the first embodiment, the distribution of density of incident light rays reaching a first sensor, a second sensor, a light emitting element, and a substrate provided in the light receiving device, and the distribution of density of incident light rays reaching the first sensor.

[0101] In FIG. 11, the trajectory of the incident light ray is shown in the first row of images, the density distribution of the incident light ray reaching the first light sensor 31, the second light sensor 32, the light emitting element 33, and the substrate 35 is shown in the second row of images, and the density distribution of the incident light ray reaching the first light sensor 31 is enlarged and shown in the third row of images. In FIG. 11, the first row of images show the results of a simulation in which the incident light ray is incident on the light receiving device 13 from the front in the depth direction DD, the second row of images show the results of a simulation in which the incident light ray is incident on the light receiving device 13 from the front in the depth direction DD in a direction inclined 45° to the left in the width direction DW, and the third row of images show the results of a simulation in which the incident light ray is incident on the light receiving device 13 from the front in the depth direction DD in a direction inclined 45° to the right in the width direction DW. The distribution of the density of the incident light ray is expressed so that the color of the focused position becomes closer to white as the density of the incident light ray at the focused position increases.

[0102] 11, the light guide 34 can guide the incident light beam to the first optical sensor 31 most efficiently when the incident light beam is incident on the light receiving device 13 from the front in the depth direction DD, and can also guide the incident light beam to the first optical sensor 31 efficiently even when the incident light beam is incident on the light receiving device 13 from a direction inclined by 45° from the front in the depth direction DD. Even in the latter case, the light guide 34 can guide the incident light beam to the first optical sensor 31 efficiently because the light guide 34 can guide the incident light beam to the first optical sensor 31 by total reflection by the first boundary surface 41c, light collection by the convex curved surface 63, and total reflection by the outer peripheral surface other than the first boundary surface 41c. As a result, the light receiving device 13 has the highest light receiving efficiency when the remote control light arrives from the front, which occurs most frequently, and has high light receiving efficiency even when the remote control light arrives from a direction other than the front. For example, in an actual device of the light receiving device 13, a remote control range of 20 m or more can be achieved, which is longer than the conventional remote control range of about 10 m.

[0103] 2. Second embodiment The following describes the differences between the second embodiment and the first embodiment. For points that are not described, the second embodiment employs the same configuration as that employed in the first embodiment.

[0104] Fig. 12 is a front view showing a first optical sensor, a light-emitting element, and a substrate provided in the display device of the second embodiment. Fig. 13 is a top view showing a first optical sensor, a light-emitting element, a light guide, and a substrate provided in the display device of the second embodiment.

[0105] In the second embodiment, as shown in FIGS. 12 and 13, the light receiving device 13 includes a first light sensor 31, a light emitting element 33, and a light emitting element 36, but does not include a second light sensor 32.

[0106] The first optical sensor 31 is disposed in the center in the width direction DW. The light emitting elements 33 and 36 are disposed on the left side in the width direction DW.

[0107] The light emitting element 36 emits the indicator light 22 when the display device 1 is turned on and displays an image. The emitted indicator light 22 is green light. Therefore, the light emitting element 36 is a green light emitting element. The light emitting element 33 is, for example, a light emitting diode.

[0108] In the second embodiment, as shown in FIG. 13, the light guide 34 has an incident surface 34j, an exit surface 34k, an incident surface 34m, and an exit surface 34n.

[0109] The incident surface 34j is disposed on the front side in the depth direction DD and can be seen from the front in the depth direction DD. The exit surface 34k is disposed on the rear side in the depth direction DD and faces the rear in the depth direction DD. The first light receiving surface 31a is disposed rearward of the exit surface 34k in the depth direction DD, faces the front in the depth direction DD, and faces the exit surface 34k. As a result, the incident surface 34j allows the remote control light to enter. The light guide 34 guides the incident remote control light from the incident surface 34j to the exit surface 34k. The exit surface 34k emits the guided remote control light. The first light receiving surface 31a receives the emitted remote control light. As a result, the light guide 34 guides the incident remote control light to the first light sensor 31. A part of the incident surface 34j also serves as the exit surface 34n.

[0110] The light-emitting elements 33 and 36 have light-emitting surfaces 33a and 36a, respectively. The light-emitting surfaces 33a and 36a face forward in the depth direction DD and emit indicator lights 21 and 22, respectively. The incident surface 34m is disposed on the rear side in the depth direction DD, faces backward in the depth direction DD, and faces the light-emitting surfaces 33a and 36a. The exit surface 34n is disposed on the front side in the depth direction DD and can be viewed from the front in the depth direction DD. Thus, the incident surface 34m causes the emitted indicator lights 21 and 22 to enter. The light guide 34 guides the incident indicator lights 21 and 22 from the incident surface 34m to the exit surface 34n. The exit surface 34n emits the guided indicator lights 21 and 22.

[0111] The entrance surface 34 j includes a flat surface 111 , a convex curved surface 112 and another convex curved surface 113 .

[0112] The flat surface 111 allows the incident light ray L41 included in the remote control light to be incident thereon. The flat surface 111 is flat. The flat surface 111 is perpendicular to the first optical axis 31b. The flat surface 111 is disposed in an area on the first light receiving surface 31a. Therefore, the first optical axis 31b passes through the flat surface 111.

[0113] The convex curved surface 112 allows the incident light beams L42 and L43 included in the remote control light to enter. The convex curved surface 112 is curved in a convex shape and has an R shape. Therefore, the convex curved surface 112 has a positive power. Therefore, the convex curved surface 112 condenses the incident light beams. The convex curved surface 112 is adjacent to the flat surface 111. The convex curved surface 112 is disposed outside the area on the first light receiving surface 31a. The convex curved surface 112 is disposed shifted to the left in the width direction DW from the area on the first light receiving surface 31a when viewed from the front in the depth direction DD. The convex curved surface 112 is perpendicular to the first optical axis 31b at the right end portion close to the flat surface 111 and smoothly connected to the flat surface 111. The convex curved surface 112 is parallel to the first optical axis 31b at the left end portion opposite to the right end portion close to the flat surface 111.

[0114] The other convex curved surface 113 is convexly curved and has an R shape. Therefore, the other convex curved surface 113 has a positive power. Therefore, the other convex curved surface 113 collects the other incident light beam. The other convex curved surface 113 is adjacent to the flat surface 111. The other convex curved surface 113 is disposed outside the area on the first light receiving surface 31a. The other convex curved surface 113 is disposed shifted to the right in the width direction DW from the area on the first light receiving surface 31a when viewed from the front in the depth direction DD. The other convex curved surface 113 is perpendicular to the first optical axis 31b at the left end portion close to the flat surface 111 and smoothly connected to the flat surface 111. The other convex curved surface 113 is parallel to the first optical axis 31b at the right end portion opposite to the left end portion close to the flat surface 111.

[0115] The light guide 34 has an interface 121 and another interface 122 .

[0116] The boundary surface 121 is disposed outside the area on the first light receiving surface 31a. The boundary surface 121 is disposed shifted to the right in the width direction DW from the area on the first light receiving surface 31a when viewed from the front in the depth direction DD. The boundary surface 121 extends from the front side where the incident surface 34j exists to the rear side where the exit surface 34k exists. The boundary surface 121 is an inclined surface inclined from a direction parallel to the first optical axis 31b, faces a direction intermediate between the right side in the width direction DW and the rear in the depth direction DD, and approaches the first optical axis 31b as it proceeds from the front side where the incident surface 34j exists to the rear side where the exit surface 34k exists.

[0117] The other boundary surface 122 is disposed outside the area on the first light receiving surface 31a. The other boundary surface 122 is disposed shifted to the left in the width direction DW from the area on the first light receiving surface 31a when viewed from the front in the depth direction DD. The other boundary surface 122 extends from the front side where the incident surface 34j exists to the rear side where the exit surface 34k exists. The other boundary surface 122 is an inclined surface inclined from a direction parallel to the first optical axis 31b, faces a direction intermediate between the left side in the width direction DW and the rear in the depth direction DD, and approaches the first optical axis 31b as it proceeds from the front side where the incident surface 34j exists to the rear side where the exit surface 34k exists.

[0118] When the incident light ray L41 travels in a direction parallel to the first optical axis 31b until it enters the light guide 34, the flat surface 111 transmits the incident light ray L41 toward the exit surface 34k. The transmitted incident light ray L41 travels through the light guide 34 and reaches the exit surface 34k. The exit surface 34k emits the incident light ray L41 that has reached it toward the first light receiving surface 31a. The first light receiving surface 31a receives the emitted incident light ray L41. When the incident light ray L41 travels through the light guide 34, it travels through the area on the first light receiving surface 31a. Therefore, the incident light ray L41 does not reach the boundary surface 121 and other boundary surfaces 122 that are located outside the area on the first light receiving surface 31a. Therefore, the boundary surface 121 and the other boundary surface 122 do not hinder the first light receiving surface 31a from receiving the incident light ray L41.

[0119] When the incident light beams L42 and L43 travel in a direction parallel to the first optical axis 31b until they enter the light guide 34, the convex curved surface 112 refracts the incident light beams L42 and L43 toward the exit surface 34k and the boundary surface 121, respectively. The incident light beam L42 refracted toward the exit surface 34k travels through the light guide 34 and reaches the exit surface 34k. The exit surface 34k emits the incident light beam L42 that has arrived toward the first light receiving surface 31a. The first light receiving surface 31a receives the emitted incident light beam L42. The incident light beam L43 refracted toward the boundary surface 121 travels through the light guide 34 and reaches the boundary surface 121. The boundary surface 121 totally reflects the incident light beam L43 that has arrived toward the exit surface 34k. The totally reflected incident light ray L43 travels through the light guide 34 and reaches the exit surface 34k. The boundary surface 121 may reflect or diffuse the incident light ray L43 toward the exit surface 34k. The reflected or diffused incident light ray L43 travels through the light guide 34 and reaches the exit surface 34k. The exit surface 34k emits the incident light ray L43 toward the first light receiving surface 31a. The first light receiving surface 31a receives the emitted incident light ray L43. Therefore, the convex curved surface 112 increases the amount of incident light received by the first light receiving surface 31a, and increases the light receiving efficiency of the light receiving device 13.

[0120] When the other incident light beams L44 and L45 travel in a direction parallel to the first optical axis 31b until they enter the light guide 34, the other convex curved surface 113 refracts the other incident light beams L44 and L45 toward the exit surface 34k and the other boundary surface 122, respectively. The other incident light beam L44 refracted toward the exit surface 34k travels through the light guide 34 and reaches the exit surface 34k. The exit surface 34k emits the other incident light beam L44 that has arrived toward the first light receiving surface 31a. The first light receiving surface 31a receives the other incident light beam L44 that has been emitted. The other incident light beam L45 refracted toward the other boundary surface 122 travels through the light guide 34 and reaches the other boundary surface 122. The other boundary surface 122 totally reflects the other incident light beam L45 that has arrived toward the exit surface 34k. The totally reflected other incident light ray L45 travels through the light guide 34 and reaches the exit surface 34k. The other boundary surface 122 may reflect or diffuse the other incident light ray L45 that has reached it toward the exit surface 34k. The reflected or diffused other incident light ray L45 may travel through the light guide 34 and reach the exit surface 34k. The exit surface 34k emits the other incident light ray L45 that has reached it toward the first light receiving surface 31a. The first light receiving surface 31a receives the other incident light ray L45 that has been emitted. Therefore, the other convex curved surface 113 increases the number of incident light rays received by the first light receiving surface 31a, and increases the light receiving efficiency of the light receiving device 13.

[0121] In the second embodiment, two convex curved surfaces, namely, the convex curved surface 112 and the other convex curved surface 113, increase the number of incident rays received by the first light receiving surface 31a. For this reason, in the second embodiment, it is possible to increase the number of incident rays received by the first light receiving surface 31a more effectively than in the case where one convex curved surface increases the number of incident rays received by the first light receiving surface 31a.

[0122] The light guide 34 has a slit 131 and another slit 132 formed therein.

[0123] The boundary surface 121 and the other boundary surface 122 face the slit 131 and the other slit 132, respectively.

[0124] The incident surface 34m allows the indicator lights 21 and 22 to enter. The incident surface 34m is flat. The incident surface 34m is perpendicular to the third optical axis 33b. The incident surface 34m is disposed in an area on the light emitting surface 33a. Therefore, the third optical axis 33b passes through the incident surface 34m.

[0125] The exit surface 34n emits the light 21 and 22. The exit surface 34n is disposed in an area on the light emitting surface 33a. Therefore, the third optical axis 33b passes through the exit surface 34n.

[0126] 3. Third embodiment The following describes the differences between the third embodiment and the second embodiment. For points that are not described, the third embodiment employs the same configuration as that employed in the second embodiment.

[0127] Fig. 14 is a front view showing a first optical sensor, a light-emitting element, and a substrate provided in the display device of the third embodiment. Fig. 15 is a top view showing a first optical sensor, a light-emitting element, a light guide, and a substrate provided in the display device of the third embodiment. Fig. 16 is a side view showing a first optical sensor, a light-emitting element, a light guide, and a substrate provided in the display device of the third embodiment.

[0128] In the third embodiment, the first optical sensor 31, the light emitting element 33, and the light emitting element 36 are disposed in the center in the width direction DW.

[0129] In the third embodiment, the light guide 34 has boundary surfaces 141 and 142 .

[0130] The boundaries 141 and 142 are disposed at the same position in the depth direction DD and the width direction DW, and are disposed at different positions in the height direction DH. The boundary surface 141 totally reflects the indicator lights 21 and 22 incident on the incident surface 34m toward the boundary surface 142. The boundary surface 142 totally reflects the totally reflected indicator lights 21 and 22 toward the exit surface 34n.

[0131] The boundary surface 121 and the other boundary surface 122 do not face a slit. The boundary surface 121 and the other boundary surface 122 may face a slit formed in the light guide .

[0132] In the third embodiment, similarly to the second embodiment, two convex curved surfaces, namely, the convex curved surface 112 and the other convex curved surface 113, increase the number of incident rays received by the first light receiving surface 31a. Therefore, similarly to the second embodiment, in the third embodiment, it is possible to increase the number of incident rays received by the first light receiving surface 31a more effectively than in the case where one convex curved surface increases the number of incident rays received by the first light receiving surface 31a.

[0133] 4 Fourth embodiment The following describes the differences between the fourth embodiment and the first embodiment. For points that are not described, the fourth embodiment employs the same configuration as that employed in the first embodiment.

[0134] Fig. 17 is a bottom view that typically illustrates a light receiving device provided in the display device of the fourth embodiment. Fig. 18 is a perspective view that typically illustrates a light receiving device provided in the display device of the fourth embodiment.

[0135] In the third embodiment, as shown in Fig. 17, the first slit 81 and the second slit 82 are formed on the main surface 34a arranged on the upper side in the height direction DH at the rear side in the depth direction DD, and are formed on the main surface 34b arranged on the lower side in the height direction DH at the front side in the depth direction DD. This makes it possible to change the appearance of the indicator light compared to the case where the first slit 81 and the second slit 82 are formed only on the main surface 34a. Other features are the same as those of the first embodiment.

[0136] The present disclosure is not limited to the above-described embodiments, and may be replaced with a configuration that is substantially the same as the configuration shown in the above-described embodiments, a configuration that has the same action and effect, or a configuration that can achieve the same purpose. [Explanation of symbols]

[0137] 1 display device, 11 display device body, 11a front surface, 11b bottom surface, 12 stand, 13 light receiving device, 21 indicator light, 31 first light sensor, 31a first light receiving surface, 31b first light axis, 32 second light sensor, 32a second light receiving surface, 3

Claims

1. an optical sensor having a light receiving surface; A light receiving device comprising a light guide having an incident surface for receiving light rays, an exit surface for emitting the light rays toward the light receiving surface, and a boundary surface for directing the light rays incident from the side where the incident surface exists toward the light receiving surface.

2. The boundary surface is disposed outside the area on the light receiving surface. The light receiving device according to claim 1 .

3. the light guide has another boundary surface that totally reflects the light ray incident from the side where the incident surface is present toward the light receiving surface, and the boundary surface is disposed offset in one direction from a region on the light receiving surface, The other boundary surface is disposed offset in the other direction from the region. The light receiving device according to claim 1 .

4. The entrance surface includes a convex curved surface that refracts the incident light toward the exit surface or the boundary surface. The light receiving device according to claim 1 .

5. The convex curved surface is disposed outside the area on the light receiving surface. The light receiving device according to claim 4.

6. the boundary surface is disposed offset in one direction from a region on the light receiving surface, The convex curved surface is offset in the other direction from the region. The light receiving device according to claim 5 .

7. the incidence surface includes another convex curved surface that refracts another incident light ray; the other convex curved surface is disposed offset in one direction from the region on the light receiving surface, The convex curved surface is offset in the other direction. The light receiving device according to claim 4.

8. The entrance surface includes a flat surface that transmits the incident light toward the exit surface. The light receiving device according to claim 1 .

9. The flat surface is disposed in an area on the light receiving surface. The light receiving device according to claim 8.

10. A slit is formed in the light guide, The boundary surface faces the slit. The light receiving device according to claim 1 .

11. The light guide has a plate-like shape having a main surface, The slit is formed in the main surface. The light receiving device according to claim 10.

12. the light receiving surface is a first light receiving surface, the optical sensor is a first optical sensor, the light beam is a first light beam, the incidence surface is a first incidence surface, the exit surface is a first exit surface, the interface is a first interface, a second optical sensor having a second light receiving surface and a light emitting element emitting a third light beam; The light guide has a second incident surface that allows a second light ray to be incident thereon, a second exit surface that allows the second light ray to be emitted toward the second light receiving surface, a second boundary surface that directs the second light ray from a side where the second incident surface exists to a side where the second exit surface exists toward the second light receiving surface, a third incident surface that allows the third light ray to be incident thereon, a third exit surface that allows the third light ray to be emitted therefrom, and a third boundary surface that directs the third light ray toward the third exit surface. The light receiving device according to claim 1.

13. The first light beam is included in a remote control light, the second light ray is included in the ambient light, The third light beam is included in the indicator light. The light receiving device according to claim 12.

14. A hole is formed in the light guide, the light guide has an inner bottom surface facing the hole, and includes a stopper spaced upward from the inner bottom surface by a first distance, and a hook spaced upward from the inner bottom surface by a second distance longer than the first distance; the substrate has a main surface that is accommodated in the hole and on which the optical sensor is mounted, a first end surface that faces a first direction and abuts against the inner bottom surface, a second end surface that faces a second direction opposite to the first direction and abuts against the hook, and a third end surface that faces a third direction intersecting the first direction and the second direction and has a protrusion formed thereon that abuts against the stopper from below. The light receiving device according to claim 1 .

15. A light receiving device according to any one of claims 1 to 14, a display device body to which the light receiving device is attached; A display device comprising:

Images