Light receiving device and display device

Abstract

Provided is a light receiving device having high light receiving efficiency. The light receiving device includes: a light sensor having a light receiving surface; and a light guide having: an incident surface on which light is incident; an emission surface that emits the light toward the light receiving surface; and a boundary surface that faces the light receiving surface with the light incident from the side on which the incident surface is located.

Description

Technical Field

[0001] The present invention relates to a light receiving device and a display device. Background Art

[0002] Patent document 1 discloses a light receiving device. In the light emitting device, remote control signal light is incident on the incident surface of a light guide. In addition, the incident remote control signal light is reflected and refracted inside the light guide. In addition, the reflected and refracted remote control signal light is emitted from the emission surface of the light guide. In addition, the emitted remote control signal light is received by the light receiving window of the light receiving sensor (paragraphs 0014, 0021, 0023 and 0025). Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2015-164282 Summary of the invention Problem that the invention aims to solve

[0004] In the light receiving device disclosed in Patent Document 1, only the remote control signal light incident on a range having a size substantially the same as that of the light receiving window can be guided to the light receiving window. Therefore, when the light guide is thinned or the light receiving sensor is miniaturized, the remote control signal light that can be guided to the light receiving window becomes less. Therefore, the light receiving efficiency of the light receiving device becomes lower.

[0005] The present disclosure is made in view of this problem. One aspect of the present disclosure is, for example, to provide a light receiving device having high light receiving efficiency. Solutions to the problem

[0006] The light receiving device of the first aspect of the present disclosure includes: a light sensor having a light receiving surface; and a light guide having: an incident surface for incident light; an exit surface for causing the light to exit toward the light receiving surface; and a boundary surface for directing the light incident from the side where the incident surface is located toward the exit surface.

[0007] A display 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 body on which the light receiving device is installed. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a perspective view schematically showing the display device according to the first embodiment. Figure 2 This is a front view schematically showing a state in which the light receiving device included in the display device according to the first embodiment does not emit instruction light. Figure 3 This is a front view schematically showing a state in which the light receiving device included in the display device according to the first embodiment emits instruction light. Figure 4 It is a perspective view schematically showing a light receiving device included in the display device according to the first embodiment. Figure 5 It is a perspective view schematically showing a light receiving device included in the display device according to the first embodiment. Figure 6 It is a perspective view schematically showing a light guide included in the display device according to the first embodiment. Figure 7 It is a cross-sectional view schematically showing a first photosensor, a second photosensor, a light emitting element, a light guide, and a substrate included in the display device according to the first embodiment. Figure 8 It is a cross-sectional view schematically showing a light guide and a substrate included in the display device according to the first embodiment. Fig. 9 This is a cross-sectional view schematically showing a state in which the light guide and the substrate included in the display device according to the first embodiment are being fixed to the light guide. Fig.10 This is a cross-sectional view schematically showing a state in which the light guide and the substrate included in the display device according to the first embodiment are being fixed to the light guide. Fig.11 The image shows the trajectory of the incident light contained in the remote control light incident on the light receiving device of the display device of the first embodiment, the density distribution of the incident light reaching the first light sensor, the second light sensor, the light-emitting element and the substrate of the light receiving device, and the density distribution of the incident light reaching the first light sensor. Fig.12 It is a front view schematically showing a first photosensor, a light emitting element, and a substrate included in the display device according to the second embodiment. Fig.13 It is a plan view schematically showing a first photosensor, a light emitting element, a light guide, and a substrate included in the display device according to the second embodiment. Fig.14 It is a front view schematically showing a first photosensor, a light emitting element, and a substrate included in the display device according to the third embodiment. Fig.15 It is a plan view schematically showing a first photosensor, a light emitting element, a light guide, and a substrate included in the display device according to the third embodiment. Fig.16 It is a side view schematically showing a first photosensor, a light emitting element, a light guide, and a substrate included in the display device according to the third embodiment. Fig.17It is a bottom view schematically showing a light receiving device included in the display device according to the fourth embodiment. Fig.18 It is a perspective view schematically showing a light receiving device included in a display device according to a fourth embodiment. DETAILED DESCRIPTION

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

[0010] 1. First Embodiment 1.1 Display Device Figure 1 It is a perspective view schematically showing the display device according to the first embodiment.

[0011] Figure 1 The display device 1 of the first embodiment shown 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, a digital signage, or the like.

[0012] The display device 1 displays images and outputs sounds.

[0013] The display device 1 receives remote control light from a remote controller (hereinafter referred to as "remote control"), and operates according to the received remote control light. For example, when the received remote control light is a remote control light instructing the display device 1 to turn on, the display device 1 is set to turn on. In addition, when the received remote control light is a remote control light instructing the display device 1 to be on standby, the display device 1 is set to be on standby. In addition, when the received remote control light is a remote control light instructing to change the channel of the selected station, the display device 1 changes the channel of the selected station. In addition, when the received remote control light is a remote control light instructing to change the volume of the output sound, the display device 1 changes the volume of the output sound. In addition, when the received remote control light is a remote control light instructing to change the selected input source, the display device 1 changes the selected input source.

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

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

[0016] The display device body 11 has a rectangular plate shape. Therefore, the display device body 11 has a front surface 11a and a bottom surface 11b. The front surface 11a is arranged on the front side of the depth direction DD of the display device 1 and faces the front of the depth direction DD. The bottom surface 11b is arranged on the lower side of the height direction DH of the display device 1 and faces the lower side of the height direction DH. The display device body 11 displays an image on the front surface 11a and outputs sound from the bottom surface 11b.

[0017] The support frame 12 supports the display device 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 body 11. The display device body 11 receives the transmitted signal from the light receiving device 13 and operates according to the received signal. Thus, the display device 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 sends a signal corresponding to the received ambient light to the display device body 11. The display device body 11 receives the signal sent from the light receiving device 13 and adjusts the displayed image according to the received signal. Thus, the display device body 11 adjusts the displayed image according to the ambient light received by the light receiving device 13.

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

[0021] The light receiving device 13 is installed in the center of the bottom surface 11b of the display device body 11 and is arranged directly below the center of the bottom surface 11b. The light receiving device 13 may also be arranged in a location other than directly below the center of the bottom surface 11b. For example, the light receiving device 13 may also be arranged directly below the left end of the bottom surface 11b, directly below the right end of the bottom surface 11b, inside the bottom frame of the display device body 11, etc.

[0022] 1.2 Indicator Light Figure 2 This is a front view schematically showing a state in which the light receiving device included in the display device according to the first embodiment does not emit instruction light. Figure 3 This is a front view schematically showing a state in which the light receiving device included in the display device according to the first embodiment emits instruction light.

[0023] When the display device 1 is turned on and displays an image, Figure 2 As shown, the light receiving device 13 is turned off and does not emit the indicator light. Thus, when the display device 1 is turned on, it is possible to suppress the indicator light from affecting the detection of the ambient light.

[0024] When the display device 1 is in standby mode and does not display an image, Figure 3 As shown, the light receiving device 13 is turned on to emit the instruction light 21. The emitted instruction light 21 is, for example, red light. The instruction light 21 may also be light other than red light.

[0025] 1.3 Light receiving device Figure 4 and Figure 5 It is a perspective view schematically showing a light receiving device included in the display device according to the first embodiment. Figure 6 It is a perspective view schematically showing a light guide included in the display device according to the first embodiment.

[0026] like Figures 4 to 6 As shown, 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 light sensor 31 detects remote control light.

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

[0029] When the display device 1 is in standby mode and does not display an image, the light emitting element 33 emits the instruction light 21. The emitted instruction 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 outside the light receiving device 13 to the first light sensor 31 and the second light sensor 32 respectively, and guides the instruction 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, resin.

[0031] The substrate 35 supports the first photosensor 31 , the second photosensor 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 light sensor 31 has a first light receiving surface 31a. The first incident surface 41a is arranged on the front side in the depth direction DD, and the first incident surface 41a can be visually identified from the front side in the depth direction DD. The first exit surface 41b is arranged on the rear side in the depth direction DD and faces the rear side in the depth direction DD. The first light receiving surface 31a is arranged at a position behind the first exit surface 41b in the depth direction DD, faces the front in the depth direction DD, and is opposite to the first exit surface 41b. Thus, the first incident surface 41a allows remote control light to be incident. 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. Thus, the first lens 41 guides the incident remote control light to the first light sensor 31. The first light 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 light 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 light sensor 32 has a second light receiving surface 32a. The second incident surface 42a is arranged on the front side in the depth direction DD, and the second incident surface 42a can be visually identified from the front side in the depth direction DD. The second exit surface 42b is arranged on the rear side in the depth direction DD and faces the rear side in the depth direction DD. The second light receiving surface 32a is arranged at a position behind the second exit surface 42b in the depth direction DD, faces the front in the depth direction DD, and is opposite to the second exit surface 42b. Thus, the second incident surface 42a allows ambient light to be incident. 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. Thus, the second lens 42 guides the incident ambient light to the second light sensor 32. The second light 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 light 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 the front in the depth direction DD and emits the indication light 21. The third incident surface 43a is arranged on the rear side in the depth direction DD, faces the rear in the depth direction DD, and is opposite to the light emitting surface 33a. The third exit surface 43b is arranged on the front side in the depth direction DD, and the third exit surface 43b can be visually identified from the front side in the depth direction DD. Thus, the third incident surface 43a allows the emitted indication light 21 to be incident. The third lens 43 guides the incident indication light 21 from the third incident surface 43a to the third exit surface 43b. The third exit surface 43b emits the guided indication light 21.

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

[0036] 1.4 Optical system for remote control light Figure 7 It is a cross-sectional view schematically showing a first photosensor, a second photosensor, a light emitting element, a light guide, and a substrate included in the display device according to the first embodiment.

[0037] like Figure 7 As shown, the first light sensor 31 has a first optical axis 31b. The first light sensor 31 has symmetrical directivity relative to the first optical axis 31b. For example, the sensitivity of the first light sensor 31 is maximum 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 incident 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 beam L11 included in the remote control light to enter. The flat surface 61 is flat. The flat surface 61 is perpendicular to the first optical axis 31b. The flat surface 61 is arranged in a region 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 L12 included in the remote control light to enter. 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 arranged outside the area on the first light receiving surface 31a. The flat surface 62 is arranged offset 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 rays L13 and L14 contained in the remote control light to be incident. The convex curved surface 63 is curved in a convex shape and has an R angle shape. Therefore, the convex curved surface 63 has a positive optical focal length. Therefore, the convex curved surface 63 converges the incident light rays. The convex curved surface 63 is adjacent to the flat surface 61. The convex curved surface 63 is arranged outside the area on the first light receiving surface 31a. The convex curved surface 63 is arranged offset to the left in the width direction DW from the area on the first light receiving surface 31a when viewed from the front side of 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 is 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 on the opposite side to the right end portion close to the flat surface 61.

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

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

[0044] The first boundary surface 41c is arranged outside the area on the first light receiving surface 31a. The first boundary surface 41c is arranged to be offset from the area on the first light receiving surface 31a to the right in the width direction DW when viewed from the front side in the depth direction DD. The first boundary surface 41c reaches the rear side where the first exit surface 41b is located from the front side where the first incident surface 41a is located. The first boundary surface 41c is an inclined surface inclined from a direction parallel to the first optical axis 31b, and is oriented in a direction between the right side in the width direction DW and the rear side in the depth direction DD, and approaches the first optical axis 31b as it moves from the front side where the first incident surface 41a is located to the rear side where the first exit surface 41b is located.

[0045] When the incident light L11 travels in a direction parallel to the first optical axis 31b until it is incident on the first lens 41, the flat surface 61 transmits the incident light L11 toward the first exit surface 41b. The transmitted incident light L11 travels in the first lens 41 and reaches the first exit surface 41b. The first exit surface 41b causes the incident light L11 that has arrived to exit toward the first light receiving surface 31a. The first light receiving surface 31a receives the exiting incident light L11. When the incident light L11 travels in the first lens 41, it travels in the area on the first light receiving surface 31a. Therefore, the incident light L11 does not reach the first boundary surface 41c outside the area configured 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 L11.

[0046] When the incident light L12 travels in a direction parallel to the first optical axis 31b until it is incident on 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 in the first lens 41 and reaches the first boundary surface 41c. The first boundary surface 41c causes the incident light L12 to be totally reflected toward the first exit surface 41b. The totally reflected incident light L12 travels in the first lens 41 and reaches the first exit surface 41b. The first boundary surface 41c may also reflect or diffuse the incident light L12 to the first exit surface 41b. The reflected or diffused incident light L12 may also travel in the first lens 41 and reach the first exit surface 41b. The first exit surface 41b causes the incident light L12 to be emitted toward the first light receiving surface 31a. The first light receiving surface 31a receives the emitted incident light L12. Therefore, the first boundary surface 41 c increases the incident light received by the first light receiving surface 31 a , thereby improving the light receiving efficiency of the light receiving device 13 .

[0047] When the incident light rays L13 and L14 travel in a direction parallel to the first optical axis 31b until they are incident on the first lens 41, the convex curved surface 63 refracts the incident light rays L13 and L14 toward the first exit surface 41b and the first boundary surface 41c, respectively. The incident light ray L13 refracted toward the first exit surface 41b travels in the first lens 41 and reaches the first exit surface 41b. The first exit surface 41b causes the incident light ray L13 that has arrived to exit toward the first light receiving surface 31a. The first light receiving surface 31a receives the incident light ray L13 that has exited. The incident light ray L14 refracted toward the first boundary surface 41c travels in the first lens 41 and reaches the first boundary surface 41c. The first boundary surface 41c causes the incident light ray L14 that has arrived to be totally reflected toward the first exit surface 41b. The totally reflected incident light ray L14 travels in the first lens 41 and reaches the first exit surface 41b. The first boundary surface 41c can also reflect or diffuse the incident light L14 arriving toward the first exit surface 41b. The reflected or diffused incident light L14 can also travel in the first lens 41 and reach the first exit surface 41b. The first exit surface 41b makes the incident light L14 arriving to be emitted 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 incident light received by the first light receiving surface 31a, thereby improving the light receiving efficiency of the light receiving device 13.

[0048] As a whole, the first boundary surface 41c increases the incident light received by the first light receiving surface 31a by totally reflecting the first light composed of the incident light rays L12 and L14 contained in the remote control light toward the first exit surface 41b, thereby improving the light receiving efficiency of the light receiving device 13.

[0049] Hereinafter, 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 approximately one time the width W11 of the first light receiving surface 31 a .

[0051] The width W13 of the convex curved surface 63 is preferably about twice the width W11 of the first light receiving surface 31a. When the width W13 is significantly smaller than about twice the width W11, there is a tendency that the incident light incident on the convex curved surface 63 decreases, and the light focused on the first light receiving surface 31a decreases. In addition, when the width W13 is significantly smaller than about twice the width W11, there is a tendency that the focal position of the convex curved surface 63 is close to the convex curved surface 63, and the light focused on the first light receiving surface 31a decreases. On the other hand, when the width W13 is significantly larger than about twice the width W11, there is a tendency that the focusing of the incident light generated by the convex curved surface 63 becomes insufficient, and the light focused on the first light receiving surface 31a decreases.

[0052] When the width W12 of the flat surface 62 is approximately one times 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 converge the incident light incident on the first incident surface 41a having a width W1 approximately four times the width W11 of the first light receiving surface 31a to the first light receiving surface 31a. As a result, the light receiving efficiency of the light receiving device 13 can be improved. These effects can be confirmed by ray tracing simulation, measurement of the arrival distance of the remote control light in an actual device, and the like. Improving the light receiving efficiency of the light receiving device 13 helps to miniaturize the light receiving device 13, extend the arrival distance of the remote control light, miniaturize the first light sensor 31, and thin the light guide 34.

[0053] The amount of incident light focused on the first light receiving surface 31a changes 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, and the distance from the first incident surface 41a to the first light receiving surface 31a. Therefore, in the light receiving device 13, these factors are adjusted in a balanced manner.

[0054] 1.5 Optical system for ambient light like Figure 7 As shown, the second light sensor 32 has a second optical axis 32b. The second light sensor 32 has a symmetrical directivity relative to the second optical axis 32b. For example, the sensitivity of the second light sensor 32 is the largest 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] like Figure 7 As shown, the second incident surface 42 a includes a flat surface 71 , a flat surface 72 , and a convex curved surface 73 .

[0056] The flat surface 71 allows the incident light L21 included in the 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 arranged in a region 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 the incident light L22 included in the ambient light to enter. 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 arranged outside the area on the second light receiving surface 32a. The flat surface 72 is arranged offset from the area on the second light receiving surface 32a to the left in the width direction DW 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 be incident. The convex curved surface 73 is curved in a convex shape and has an R angle shape. Therefore, the convex curved surface 73 has a positive optical focal length. Therefore, the convex curved surface 73 converges the incident light rays. The convex curved surface 73 is adjacent to the flat surface 71. The convex curved surface 73 is arranged outside the area on the second light receiving surface 32a. The convex curved surface 73 is arranged offset to the right in the width direction DW from the area on the second light receiving surface 32a when viewed from the front side of 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 is 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 on the opposite side to the left end portion close to the flat surface 71.

[0059] The second exit surface 42b allows the incident light L21, L22, L23 and L24 to exit. The second exit surface 42b is flat. The second exit surface 42b is arranged 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 boundary surface 42c.

[0061] The second boundary surface 42c is arranged outside the area on the second light receiving surface 32a. The second boundary surface 42c is arranged to be offset from the area on the second light receiving surface 32a to the left in the width direction DW when viewed from the front side in the depth direction DD. The second boundary surface 42c reaches the rear side where the second exit surface 42b is located from the front side where the second incident surface 42a is located. The second boundary surface 42c is an inclined surface inclined from a direction parallel to the second optical axis 32b, and is oriented in a direction between the left side in the width direction DW and the rear side in the depth direction DD, and approaches the second optical axis 32b as it moves from the front side where the second incident surface 42a is located to the rear side where the second exit surface 42b is located.

[0062] When the incident light L21 travels in a direction parallel to the second optical axis 32b until it is incident on the second lens 42, the flat surface 71 transmits the incident light L21 toward the second exit surface 42b. The transmitted incident light L21 travels in the second lens 42 and reaches the second exit surface 42b. The second exit surface 42b causes the arriving incident light L21 to exit toward the second light receiving surface 32a. The second light receiving surface 32a receives the exiting incident light L21. When the incident light L21 travels in the second lens 42, it travels in the area on the second light receiving surface 32a. Therefore, the incident light L21 does not reach the second boundary surface 42c outside the area configured 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 L21.

[0063] When the incident light L22 travels in a direction parallel to the second optical axis 32b until it is incident on the second lens 42, the flat surface 72 transmits the incident light L22 toward the second boundary surface 42c. The transmitted incident light L22 travels in the second lens 42 and reaches the second boundary surface 42c. The second boundary surface 42c causes the arriving incident light L22 to be totally reflected toward the second exit surface 42b. The totally reflected incident light L22 travels in the second lens 42 and reaches the second exit surface 42b. The second boundary surface 42c can also reflect or diffuse the arriving incident light L22 toward the second exit surface 42b. The reflected or diffused incident light L22 can also travel in the second lens 42 and reach the second exit surface 42b. The second exit surface 42b causes the arriving incident light L22 to exit toward the second light receiving surface 32a. The second light receiving surface 32a receives the exiting incident light L22. Therefore, the second boundary surface 42 c increases the incident light received by the second light receiving surface 32 a , thereby improving the light receiving efficiency of the light receiving device 13 .

[0064] When the incident light rays L23 and L24 travel in a direction parallel to the second optical axis 32b until they are incident on the second lens 42, the convex curved surface 73 refracts the incident light rays L23 and L24 toward the second exit surface 42b and the second boundary surface 42c, respectively. The incident light ray L23 refracted toward the second exit surface 42b travels in the second lens 42 and reaches the second exit surface 42b. The second exit surface 42b causes the incident light ray L23 that has arrived to exit toward the second light receiving surface 32a. The second light receiving surface 32a receives the incident light ray L23 that has exited. The incident light ray L24 refracted toward the second boundary surface 42c travels in the second lens 42 and reaches the second boundary surface 42c. The second boundary surface 42c causes the incident light ray L24 that has arrived to be totally reflected toward the second exit surface 42b. The totally reflected incident light ray L24 travels in the second lens 42 and reaches the second exit surface 42b. The second boundary surface 42c can also reflect or diffuse the incident light L24 that arrives toward the second exit surface 42b. The totally reflected incident light L24 travels in the second lens 42 and arrives at the second exit surface 42b. The second exit surface 42b causes the incident light L24 that arrives to exit toward the second light receiving surface 32a. The second light receiving surface 32a receives the exiting incident light L24. Therefore, the convex curved surface 73 increases the incident light received by the second light receiving surface 32a, thereby improving the light receiving efficiency of the light receiving device 13.

[0065] As a whole, the second boundary surface 42c increases the incident light received by the second light receiving surface 32a and improves the light receiving efficiency of the light receiving device 13 by causing the second light composed of the incident light L22 and L24 contained in the ambient light to be totally reflected toward the second exit surface 42b, thereby increasing the incident light received by the second light receiving surface 32a.

[0066] Hereinafter, 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 approximately one time the width W21 of the second light receiving surface 32 a .

[0068] The width W23 of the convex curved surface 73 is preferably approximately 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 approximately twice the width W11 of the first light receiving surface 31a.

[0069] When the width W22 of the flat surface 72 is about one time the width W21 of the second light receiving surface 32a and the width W23 of the convex curved surface 73 is about two times the width W21 of the second light receiving surface 32a, the second lens 42 can converge the incident light incident on the second incident surface 42a having a width W2 about four times the width W21 of the second light receiving surface 32a to the second light receiving surface 32a. Thus, the light receiving efficiency of the light receiving device 13 can be improved. These effects can be confirmed by ray tracing simulation, measurement of the arrival distance of the remote control light in the actual device, etc. Improving the light receiving efficiency of the light receiving device 13 helps to miniaturize the light receiving device 13, miniaturize the second light sensor 32, and thin the light guide 34.

[0070] The amount of incident light focused on the second light receiving surface 32a changes 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, and the distance from the second incident surface 42a to the second light receiving surface 32a. Therefore, in the light receiving device 13, these factors are adjusted in a balanced manner.

[0071] 1.6 Optical system for indicator light like Figure 7 As shown, the light emitting element 33 has a third optical axis 33b. The light emitting element 33 has a directivity that is symmetrical with respect to the third optical axis 33b. The light emitting intensity of the light emitting element 33 is, for example, the maximum 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 outgoing light beams L31, L32 and L33 included in the indicator light 21 to be incident. The outgoing light beam L31 travels in a direction parallel to the third optical axis 33b. The outgoing light beam L32 travels in a direction inclined to the left of the width direction DW from the direction parallel to the third optical axis 33b. The outgoing light beam L33 travels in a direction inclined to the right of the width direction DW from the 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 arranged 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 allows the exit light L31, L32 and L33 to exit. 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 arranged 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] like Figure 7 As shown, the third lens 43 has third boundary surfaces 43c1 and 43c2.

[0075] The third boundary surface 43c1 is located outside the area on the light emitting surface 33a. The third boundary surface 43c1 is arranged to be offset from the area on the light emitting surface 33a to the left in the width direction DW when viewed from the front side in the depth direction DD. The third boundary surface 43c1 reaches the rear side where the third incident surface 43a is located from the front side where the third exit surface 43b is located. The third boundary surface 43c1 is an inclined surface inclined from a direction parallel to the third optical axis 33b, and is oriented in a middle direction between the left side in the width direction DW and the rear side in the depth direction DD, and approaches the third optical axis 33b as it moves from the front side where the third exit surface 43b is located to the rear side where the third incident surface 43a is located.

[0076] The third boundary surface 43c2 is located outside the area on the light emitting surface 33a. The third boundary surface 43c2 is arranged to be offset from the area on the light emitting surface 33a to the right in the width direction DW when viewed from the front side of the depth direction DD. The third boundary surface 43c2 reaches the rear side of the third incident surface 43a from the front side where the third exit surface 43b is located. The third boundary surface 43c2 is an inclined surface inclined from a direction parallel to the third optical axis 33b, and is oriented in a direction between the right side in the width direction DW and the rear side in the depth direction DD, and approaches the third optical axis 33b as it moves from the front side where the third exit surface 43b is located to the rear side where the third incident surface 43a is located.

[0077] The third incident surface 43a transmits the outgoing light L31 toward the third outgoing surface 43b. The transmitted outgoing light L31 travels in the third lens 43 and reaches the third outgoing surface 43b. The third outgoing surface 43b allows the outgoing light L31 to be emitted.

[0078] The third incident surface 43a transmits the outgoing light L32 toward the third boundary surface 43c1. The transmitted outgoing light L32 travels in the third lens 43 and reaches the third boundary surface 43c1. The third boundary surface 43c1 causes the arriving outgoing light L32 to be totally reflected toward the third exit surface 43b. The totally reflected outgoing light L32 travels in the third lens 43 and reaches the third exit surface 43b. The third exit surface 43b causes the arriving outgoing light L32 to exit. The third boundary surface 43c1 may also reflect or diffuse the arriving outgoing light L32 toward the third exit surface 43b. The reflected or diffused outgoing light L32 may also travel in the third lens 43 and reach the third exit surface 43b.

[0079] The third incident surface 43a transmits the outgoing light L33 toward the third boundary surface 43c2. The transmitted outgoing light L33 travels in the third lens 43 and reaches the third boundary surface 43c2. The third boundary surface 43c2 causes the arriving outgoing light L33 to be totally reflected toward the third exit surface 43b. The totally reflected outgoing light L33 travels in the third lens 43 and reaches the third exit surface 43b. The third boundary surface 43c2 may also reflect or diffuse the arriving outgoing light L33 toward the third exit surface 43b. The reflected or diffused outgoing light L33 may also travel in the third lens 43 and reach the third exit surface 43b. The third exit surface 43b causes the arriving outgoing light L33 to exit.

[0080] As a whole, the third boundary surfaces 43c1 and 43c2 cause the third light consisting of the outgoing light beams L32 and L33 included in the indication light 21 emitted by the light emitting element 33 to be totally reflected toward the third outgoing surface 43b.

[0081] 1.7 Formation of the Slit on the Light Guide like Figures 5 to 7 As shown, a first slit 81 and a second slit 82 are formed in the light guide 34 .

[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 arranged on the upper side of the height direction DH. The main surface 34b is arranged on the lower side of the height direction DH. The first slit 81 and the second slit 82 are formed on the main surface 34a. The first slit 81 and the second slit 82 have a groove-like shape. The first slit 81 and the second slit 82 can be formed on the main surface 34b, or can be formed dispersedly 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 first 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 constitute the inner side surface of the first slit 81.

[0085] The second boundary surface 42c and the third boundary surface 43c2 face the first 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 constitute the inner side surface of the second slit 82.

[0086] 1.8 Fixation of the substrate relative to the light guide like Figure 5 and Figure 7As shown, the substrate 35 has a first main surface 35 a and a second main surface 35 b .

[0087] The first main surface 35a and the second main surface 35b are located on opposite sides. The first main surface 35a is arranged on the front side of the depth direction DD and faces the front side of the depth direction DD. The first light sensor 31, the second light sensor 32 and the light emitting element 33 are mounted on the first main surface 35a. The second emission surface 35b is arranged on the rear side of the depth direction DD and faces the rear side of the depth direction DD.

[0088] Figure 8 It is a cross-sectional view schematically showing a light guide and a substrate included in the display device according to the first embodiment.

[0089] like Figure 8 As shown in FIG. 1 , the substrate 35 has a rectangular plate shape. Therefore, the substrate 35 has a first end surface 35c, a second end surface 35d, a third end surface 35e, and a fourth end surface 35f.

[0090] The first end face 35c and the second end face 35d are located on opposite sides to each other. The third end face 35e and the fourth end face 35f are located 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 the first direction D1 and the second direction D2. The fourth end face 35f intersects the first direction D1 and the second direction D2 and faces the fourth direction D4 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] like Figure 5 , Figure 6 and Figure 8 As shown, the light guide 34 includes a stopper 101 and a hook 102 .

[0093] The stopper 101 has a hook shape. The stopper 101 is separated from the inner bottom surface 34c upward in the height direction DH by a first distance. The hook 102 is separated from the inner bottom surface 34c upward in the height direction DH by a second distance 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 contacts the inner bottom surface 34c. Thus, the downward movement of the substrate 35 in the height direction DH is restricted.

[0095] When the substrate 35 is received in the hole 34h, the protrusion 91 contacts the stopper 101 from behind in the depth direction DD and from below in the height direction DH. Thus, the substrate 35 is restricted from moving upward in the height direction DH and forward in the depth direction DD.

[0096] When the substrate 35 is received in the hole 34h, the second main surface 35b contacts the hook 102 from the front in the depth direction DD, and the second end surface 35d contacts the hook 102 from the bottom in the height direction DH. Thus, the substrate 35 is restricted from moving upward in the height direction DH and backward in the depth direction DD.

[0097] Thereby, the substrate 35 is fixed to the light guide 34 .

[0098] Fig. 9 and Fig.10 This is a cross-sectional view schematically showing a state in which the light guide and the substrate included in the display device according to the first embodiment are 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. Fig. 9 As shown in FIG. 1 , the substrate 35 is inserted into the hole 34h in a state where the protrusion 91 is arranged below the stopper 101 in the height direction DH. Fig.10 and Figure 8 As shown, the substrate 35 rotates until the first end surface 35c contacts the inner bottom surface 34c. When the substrate 35 rotates until the first end surface 35c contacts the inner bottom surface 34c, the elastically deformed hook 102 returns to its original position. Thus, the substrate 35 is fixed to the light guide 34.

[0100] 1.9 Simulation Fig.11 The image shows the trajectory of the incident light contained in the remote control light incident on the light receiving device of the display device of the first embodiment, the density distribution of the incident light reaching the first light sensor, the second light sensor, the light-emitting element and the substrate of the light receiving device, and the density distribution of the incident light reaching the first light sensor.

[0101] Fig.11 The trajectory of the incident light is shown in the first row of images, the distribution of the density of the incident light 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 distribution of the density of the incident light reaching the first light sensor 31 is enlarged and shown in the third row of images. Fig.11In the figure, the simulation results when the incident light enters the light receiving device 13 from the front of the depth direction DD are shown in the first row of images, the simulation results when the incident light enters the light receiving device 13 from the front of the depth direction DD in a direction inclined 45° to the left of the width direction DW are shown in the second row of images, and the simulation results when the incident light enters the light receiving device 13 from the front of the depth direction DD in a direction inclined 45° to the right of the width direction DW are shown in the third row of images. The distribution of the density of the incident light is shown in that the higher the density of the incident light at the position of interest, the closer the color of the position of interest is to white.

[0102] like Fig.11 As shown, the light guide 34 can guide the incident light to the first light sensor 31 most efficiently when the incident light enters the light receiving device 13 from the front in the depth direction DD, and can guide the incident light to the first light sensor 31 efficiently even when the incident light enters the light receiving device 13 from the front in the depth direction DD at an angle of 45°. In the latter case, the light guide 34 can guide the incident light to the first light sensor 31 efficiently because the light guide 34 can guide the incident light to the first light sensor 31 by total reflection generated by the first boundary surface 41c, light focusing 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 side, which is the most frequently generated light, and also has a high light receiving efficiency when the remote control light arrives from other than the front side. For example, in the actual device of the light receiving device 13, a remote control reaching distance of more than 20m, which is longer than the conventional remote control reaching distance of about 10m, can be achieved.

[0103] 2 Second Embodiment The following describes the differences between the second embodiment and the first embodiment. In the second embodiment, the same configuration as that of the first embodiment is adopted for the undescribed aspects.

[0104] Fig.12 It is a front view schematically showing a first photosensor, a light emitting element, and a substrate included in the display device according to the second embodiment. Fig.13 It is a plan view schematically showing a first photosensor, a light emitting element, a light guide, and a substrate included in the display device according to the second embodiment.

[0105] In a second embodiment, if Fig.12 and Fig.13 As shown, 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 arranged at the center in the width direction DW. The light emitting elements 33 and 36 are arranged on the left side in the width direction DW.

[0107] When the display device 1 is turned on and displays an image, the light emitting element 36 emits the indication light 22. The indication light 22 emitted 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 addition, in the second embodiment, if Fig.13 As shown, 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 arranged on the front side in the depth direction DD, and the incident surface 34j can be visually identified from the front side in the depth direction DD. The exit surface 34k is arranged on the rear side in the depth direction DD and faces the rear side in the depth direction DD. The first light receiving surface 31a is arranged at a position rearward of the exit surface 34k in the depth direction DD, faces the front in the depth direction DD, and is opposite to the exit surface 34k. Thus, the incident surface 34j allows the remote control light to be incident. 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. Thus, the light guide 34 guides the incident remote control light to the first light sensor 31. A portion 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 the indication lights 21 and 22, respectively. The incident surface 34m is arranged on the rear side of the depth direction DD, faces rearward in the depth direction DD, and is opposite to the light emitting surfaces 33a and 36a. The exit surface 34n is arranged on the front side of the depth direction DD, and the exit surface 34n can be visually identified from the front side of the depth direction DD. Thus, the incident surface 34m allows the emitted indication lights 21 and 22 to be incident. The light guide 34 guides the incident indication lights 21 and 22 from the incident surface 34m to the exit surface 34n. The exit surface 34n emits the guided indication lights 21 and 22.

[0111] The incident 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 L41 included in the remote control light to enter. The flat surface 111 is flat. The flat surface 111 is perpendicular to the first optical axis 31b. The flat surface 111 is arranged in a region 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 rays L42 and L43 contained in the remote control light to be incident. The convex curved surface 112 is curved in a convex shape and has an R angle shape. Therefore, the convex curved surface 112 has a positive optical focal length. Therefore, the convex curved surface 112 converges the incident light rays. The convex curved surface 112 is adjacent to the flat surface 111. The convex curved surface 112 is arranged outside the area on the first light receiving surface 31a. The convex curved surface 112 is arranged offset 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 is 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 on the opposite side to the right end portion close to the flat surface 111.

[0114] The other convex curved surface 113 is curved into a convex shape and has an R angle shape. Therefore, the other convex curved surface 113 has a positive optical focal length. Therefore, the other convex curved surface 113 converges other incident light rays. The other convex curved surface 113 is adjacent to the flat surface 111. The other convex curved surface 113 is arranged outside the area on the first light receiving surface 31a. The other convex curved surface 113 is arranged offset 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 is 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 on the opposite side of the left end portion close to the flat surface 111.

[0115] The light guide 34 has a boundary surface 121 and another boundary surface 122 .

[0116] The boundary surface 121 is arranged outside the area on the first light receiving surface 31a. The boundary surface 121 is arranged offset from the area on the first light receiving surface 31a to the right in the width direction DW when viewed from the front in the depth direction DD. The boundary surface 121 reaches the rear side where the exit surface 34k is located from the front side where the incident surface 34j is located. The boundary surface 121 is an inclined surface inclined from a direction parallel to the first optical axis 31b, and is oriented in a direction between the right side in the width direction DW and the rear side in the depth direction DD, and approaches the first optical axis 31b as it moves from the front side where the incident surface 34j is located to the rear side where the exit surface 34k is located.

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

[0118] When the incident light ray L41 travels in a direction parallel to the first optical axis 31b until it is incident on 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 in the light guide 34 and reaches the exit surface 34k. The exit surface 34k causes the incident light ray L41 that has arrived to be emitted 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 in the light guide 34, it travels in 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 outside the area configured on the first light receiving surface 31a. Therefore, the boundary surface 121 and other boundary surfaces 122 do not prevent the first light receiving surface 31a from receiving the incident light ray L41.

[0119] When the incident light rays L42 and L43 travel in a direction parallel to the first optical axis 31b until they are incident on the light guide 34, the convex curved surface 112 refracts the incident light rays L42 and L43 toward the exit surface 34k and the boundary surface 121, respectively. The incident light ray L42 refracted toward the exit surface 34k travels in the light guide 34 and reaches the exit surface 34k. The exit surface 34k causes the incident light ray L42 that has arrived to exit toward the first light receiving surface 31a. The first light receiving surface 31a receives the exiting incident light ray L42. The incident light ray L43 refracted toward the boundary surface 121 travels in the light guide 34 and reaches the boundary surface 121. The boundary surface 121 causes the incident light ray L43 that has arrived to be totally reflected toward the exit surface 34k. The totally reflected incident light ray L43 travels in the light guide 34 and reaches the exit surface 34k. The boundary surface 121 can also reflect or diffuse the incident light L43 that arrives toward the exit surface 34k. The reflected or diffused incident light L43 can also travel in the light guide 34 and arrive at the exit surface 34k. The exit surface 34k causes the incident light L43 that arrives to be emitted toward the first light receiving surface 31a. The first light receiving surface 31a receives the emitted incident light L43. Therefore, the convex curved surface 112 increases the incident light received by the first light receiving surface 31a, thereby improving the light receiving efficiency of the light receiving device 13.

[0120] When the other incident light rays L44 and L45 travel in a direction parallel to the first optical axis 31b until they are incident on the light guide 34, the other convex curved surfaces 113 refract the other incident light rays L44 and L45 toward the exit surface 34k and the other boundary surfaces 122, respectively. The other incident light ray L44 refracted toward the exit surface 34k travels in the light guide 34 and reaches the exit surface 34k. The exit surface 34k causes the other incident light ray L44 that has arrived to exit toward the first light receiving surface 31a. The first light receiving surface 31a receives the other incident light ray L44 that has exited. The other incident light ray L45 refracted toward the other boundary surfaces 122 travels in the light guide 34 and reaches the other boundary surfaces 122. The other boundary surfaces 122 cause the other incident light ray L45 that has arrived to be totally reflected toward the exit surface 34k. The totally reflected other incident light ray L45 travels in the light guide 34 and reaches the exit surface 34k. The other boundary surfaces 122 may also reflect or diffuse the other incident light rays L45 that arrive toward the exit surface 34k. The other incident light rays L45 that are reflected or diffused may also travel in the light guide 34 and arrive at the exit surface 34k. The exit surface 34k causes the other incident light rays L45 that arrive to be emitted toward the first light receiving surface 31a. The first light receiving surface 31a receives the emitted other incident light rays L45. Therefore, the other convex curved surfaces 113 increase the incident light rays received by the first light receiving surface 31a, thereby improving the light receiving efficiency of the light receiving device 13.

[0121] In the second embodiment, the two convex curved surfaces composed of the convex curved surface 112 and the other convex curved surface 113 increase the incident light received by the first light receiving surface 31a. Therefore, in the second embodiment, compared with the case where the incident light received by the first light receiving surface 31a is increased by one more convex curved surface, the incident light received by the first light receiving surface 31a can be effectively increased.

[0122] The slit 131 and other slits 132 are formed in the light guide 34 .

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

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

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

[0126] 3. Third Embodiment Hereinafter, the differences between the third embodiment and the second embodiment will be described. Regarding the undescribed aspects, the third embodiment also adopts the same configuration as that adopted in the second embodiment.

[0127] Fig.14 It is a front view schematically showing a first photosensor, a light emitting element, and a substrate included in the display device according to the third embodiment. Fig.15 It is a plan view schematically showing a first photosensor, a light emitting element, a light guide, and a substrate included in the display device according to the third embodiment. Fig.16 It is a side view schematically showing a first photosensor, a light emitting element, a light guide, and a substrate included in the display device according to 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 arranged at the center in the width direction DW.

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

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

[0131] The boundary surface 121 and the other boundary surfaces 122 do not face the slit. The boundary surface 121 and the other boundary surfaces 122 may face the slit formed in the light guide 34 .

[0132] In the third embodiment, similarly to the second embodiment, the two convex curved surfaces composed of the convex curved surface 112 and the other convex curved surface 113 also increase the incident light received by the first light receiving surface 31a. Therefore, in the third embodiment, similarly to the second embodiment, compared with the case where the incident light received by the first light receiving surface 31a is increased by one convex curved surface, the incident light received by the first light receiving surface 31a can be effectively increased.

[0133] 4 Fourth Embodiment Hereinafter, the differences between the fourth embodiment and the first embodiment will be described. Regarding the undescribed aspects, the fourth embodiment also adopts the same configuration as that adopted in the first embodiment.

[0134] Fig.17 It is a bottom view schematically showing a light receiving device included in the display device according to the fourth embodiment. Fig.18It is a perspective view schematically showing a light receiving device included in a display device according to a fourth embodiment.

[0135] In a fourth embodiment, if Fig.17 As shown in FIG. 1 , the first slit 81 and the second slit 82 are formed on the main surface 34a disposed 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 disposed on the lower side in the height direction DH at the front side in the depth direction DD. Thus, compared with the case where the first slit 81 and the second slit 82 are formed only on the main surface 34a, the appearance of the indicator light can be changed. It can be said that the 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 achieves the same function and effect, or a configuration that can achieve the same purpose.

Claims

1. A light receiving device, characterized in that: include: a light sensor having a light receiving surface; as well as A light guide having: An incident surface, which allows the light to enter; An emitting surface, which allows the light to be emitted toward the light receiving surface; as well as A boundary surface directs the light incident from the side where the incident surface is located toward the light receiving surface.

2. The light receiving device according to claim 1, characterized in that The boundary surface is arranged outside a region on the light receiving surface.

3. The light receiving device according to claim 1, characterized in that The light guide has another boundary surface, and the other boundary surface directs the light incident from the side where the incident surface is located toward the light receiving surface and totally reflects other light. The boundary surface is arranged to be offset in one direction from the region on the light receiving surface, and the other boundary surface is arranged to be offset in another direction from the region.

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

5. The light receiving device according to claim 4, characterized in that The convex curved surface is arranged outside a region on the light receiving surface.

6. The light receiving device according to claim 5, characterized in that The boundary surface is arranged to be offset in one direction from a region on the light receiving surface, and the convex curved surface is arranged to be offset in another direction from the region.

7. The light receiving device according to claim 4, characterized in that The incident surface includes other convex curved surfaces, and the other convex curved surfaces refract other incident light rays, The other convex curved surface is arranged to be offset in one direction from the region on the light receiving surface, and the convex curved surface is arranged to be offset in another direction.

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

9. The light receiving device according to claim 8, characterized in that The flat surface is arranged in a region on the light receiving surface.

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

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

12. The light receiving device according to claim 1, characterized in that The light-receiving surface is a first light-receiving surface, The light sensor is a first light sensor, the light is a first light, The incident surface is a first incident surface, The exit surface is a first exit surface, the boundary surface is a first boundary surface, The light receiving device comprises: a second light sensor having a second light receiving surface; and a light emitting element that emits a third light, The light guide has: a second incident surface for incident second light; a second emitting surface, which allows the second light to be emitted toward the second light receiving surface; a second boundary surface that directs the second light from the side where the second incident surface is located to the side where the second exit surface is located toward the second light receiving surface; a third incident surface for causing the third light to be incident; A third exit surface, which allows the third light to exit; and A third boundary surface directs the third light toward the third exit surface.

13. The light receiving device according to claim 12, characterized in that: The first light is included in the remote control light, the second light is included in the ambient light, The third light is included in the indicator light.

14. The light receiving device according to claim 1, characterized in that The light guide has a hole formed therein, The light guide comprises: a stopper having an inner bottom surface facing the hole and being upwardly spaced a first distance from the inner bottom surface; and a hook which is upwardly spaced from the inner bottom surface by a second distance which is longer than the first distance, The light receiving device includes a substrate, and the substrate has: a main surface, which is received in the hole and has the optical sensor mounted thereon; A first end surface facing a first direction and contacting the inner bottom surface; a second end surface facing a second direction opposite to the first direction and in contact with the hook; The third end surface faces a third direction intersecting the first direction and the second direction and has a protrusion formed thereon that contacts the stopper from below.

15. A display device, characterized in that: include: The light receiving device according to any one of claims 1 to 14; as well as The display device body is equipped with the light receiving device.

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