Light reception device and display device

Abstract

To provide a light reception device capable of improving the reach of signal light incident at a specific angle, and to provide a display device.SOLUTION: A light reception device is provided, comprising: a light guide body including a first light guide body having an incident surface for external light to enter and a second light guide body having an exit surface for the light to exit; and a photoreception sensor for receiving the light exiting from the exit surface; where a side face of the first light guide body includes a tapered portion tapering down toward the incident surface side.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] A light receiving device that improves the light reception sensitivity of a remote control signal light is known. For example, Patent Document 1 discloses a light receiving device having a light guide body including a first light guide body having a rounded rectangular cross section including an incident surface for incident remote control signal light, and a second light guide body having a substantially rectangular cross section including an emission surface for emitting remote control signal light.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the light receiving device disclosed in Patent Document 1, depending on the incident angle of the remote control signal light, the maximum distance at which a thin liquid crystal television can be operated by the remote control device may be shorter than that of a light receiving device constituted by a light guide body having a rectangular cross section. That is, in the light receiving device disclosed in Patent Document 1, depending on the incident angle of the remote control signal light, the reach distance of the remote control signal light decreases.

[0005] The present disclosure has been made in view of the above problems. An object of the present disclosure is to provide a light receiving device and a display device capable of improving the reach distance of signal light incident from a specific angle.

Means for Solving the Problems

[0006] A light receiving device according to an aspect of the present disclosure includes a first light guide including an incident surface on which light from the outside is incident, a second light guide including an emission surface that emits the light, a light guide including the first and second light guides, and a light receiving sensor that receives the light emitted from the emission surface. A side surface of the first light guide includes a tapered portion that widens toward the incident surface side.

Advantages of the Invention

[0007] According to the present disclosure, it is possible to provide a light receiving device and a display device capable of improving the reach of signal light incident from a specific angle.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Modes for Carrying Out the Invention

[0009] Embodiments of the present disclosure will be described with reference to the drawings. In the following, the same or corresponding elements throughout all the drawings are denoted by the same reference numerals, and the redundant description thereof will be omitted as appropriate. Further, the embodiments described below are merely examples of the present disclosure, and the present disclosure is not limited to the embodiments. Various modifications can be made according to the design and the like as long as they do not depart from the technical idea of the present disclosure even if they are other than the embodiments described below.

[0010] (First Embodiment) With reference to FIGS. 1 and 2, the configuration of a display device 100 according to a first embodiment of the present disclosure will be described. FIG. 1 is a perspective view schematically showing the appearance of the display device 100 according to the first embodiment of the present disclosure. FIG. 2 is an enlarged view of part A in the display device 100 of FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III of part A in the display device 100 of FIG. 1.

[0011] Hereinafter, as the display device 100, a thin-film liquid crystal television using a flat liquid crystal panel for a display screen will be described as an example.

[0012] As shown in FIG. 1, the display device 100 includes a liquid crystal panel 1 and a cabinet 2 provided around the liquid crystal panel 1. The cabinet 2 can be formed by molding a metal such as aluminum or a resin such as plastic. As shown in FIG. 2, a light receiving portion 3 is provided at the central portion in the lower region of the cabinet 2.

[0013] The light receiving portion 3 includes a light receiving window 3a and a light receiving device 10. The light receiving window 3a is an opening formed in the cabinet 2 through which the remote control signal light 15, which is an infrared signal emitted from a remote control device (not shown), is incident.

[0014] The light receiving device 10 receives the light incident through the light receiving window 3a and outputs an electrical signal. Hereinafter, the configuration of the light receiving device 10 will be described in detail.

[0015] (Light Receiving Device) As shown in FIG. 3, the light receiving device 10 is mounted on the printed circuit board 7 and includes a light receiving sensor 6 that converts the remote control signal light 15 into an electrical signal, and a light guide 5 that guides the remote control signal light incident through the light receiving window 3a to the light receiving sensor 6.

[0016] The light guide 5 is a substantially columnar member formed of a transparent resin material such as acrylic or polycarbonate. The light guide 5 is configured to allow the remote control signal light 15 incident from the outside to be reflected inside and travel toward the light receiving sensor 6. That is, the light guide 5 includes an incident surface on which the remote control signal light 15 from the outside is incident, and an exit surface that emits the light incident on the light guide 5 toward the light receiving sensor 6. The light guide 5 functions as a core that forms the optical path of the remote control signal light 15. The core formed by the light guide 5 is surrounded by a cladding. The core and the cladding have different refractive indices, and the remote control signal light 15 can undergo total reflection at the boundary surface between the two and travel with almost no loss.

[0017] Next, with reference to FIG. 4, the details of the configuration of the light guide 5 will be described. FIG. 4 is a cross-sectional view showing the schematic configuration of the light guide 5 included in the light receiving device 10 of FIG. 3. The cross-sectional view shown in FIG. 4 shows a horizontal plane cut out along the length L direction of the light guide 5.

[0018] Here, the length L of the light guide 5 is the distance from the incident surface 51 to the exit surface 52 of the light guide 5, and the length L direction is the extending direction of the length L. Also, the direction intersecting (orthogonal in this specification) the length L direction is referred to as the width W direction of the light guide 5. The length L direction coincides with the depth (front-rear) direction of the display device 100 in a state where the light receiving device 10 including the light guide 5 is attached to the display device 100 (that is, the state shown in FIG. 1). Also, the width W direction coincides with the width (left-right) direction of the display device 100 in a state where the light receiving device 10 including the light guide 5 is attached to the display device 100.

[0019] The light guide 5 has a substantially rectangular shape with a length L as the long side and a width W as the short side in the direction of the horizontal plane shown in the cross-sectional view of FIG. 4. However, since the shape of the horizontal plane of the first light guide 5a is not rectangular as described later, the light guide 5 does not have a strictly rectangular shape. Here, the width W indicates the minimum width of the light guide 5. In the present embodiment, since the minimum width of the light guide 5 is the width of the exit surface 52 and the boundary 53 described later, the width W coincides with the width of the exit surface 52 and the boundary 53. The height of the light guide 5 is constant. The height direction of the light guide 5 is the depth direction in FIG. 4. That is, in the light guide 5, the length in the direction orthogonal to the horizontal plane is constant.

[0020] As shown in FIG. 4, the light guide 5 includes a first light guide 5a and a second light guide 5b. The first light guide 5a includes an incident surface 51 on which light (remote control signal light 15) from the outside is incident. That is, the first light guide 5a is located on the incident surface 51 side in the light guide 5. The second light guide 5b includes an exit surface 52 that exits the light incident on the light guide 5. That is, the second light guide 5b is located on the exit surface 52 side in the light guide 5. The light receiving sensor 6 receives the light emitted from the exit surface 52. In FIG. 4, the boundary 53 between the first light guide 5a and the second light guide 5b is shown by a broken line, but the broken line is shown for the understanding of the present embodiment. Actually, there is no configuration showing any boundary line or boundary surface between the first light guide 5a and the second light guide 5b, and the first light guide 5a and the second light guide 5b are configured as a single member.

[0021] As shown in FIG. 4, in the present embodiment, on the horizontal plane of the light guide 5, a straight line passing through the center of the incident surface 51 and the center of the exit surface 52 is defined as the central axis C. The central axis C is orthogonal to the exit surface 52. In the present embodiment, the light guide 5 is formed symmetrically about the central axis C. In the present embodiment, the light receiving sensor 6 is arranged on the central axis C as shown in FIG. 4. That is, the light receiving sensor 6 is arranged symmetrically about the central axis C of the light guide 5.

[0022] In this embodiment, as shown in FIG. 4, the first light guide 5a has a trapezoidal shape in the horizontal plane. Specifically, the first light guide 5a has an isosceles trapezoidal shape that is symmetric about the central axis C, with the incident surface 51 being longer than the boundary 53 in the horizontal plane. The side surface of the first light guide 5a in the width W direction includes a tapered portion 54 that tapers toward the incident surface side. In other words, the side surface of the first light guide 5a includes a tapered portion 54 that approaches the central axis C as it extends from the incident surface 51 toward the emission surface 52. In this embodiment, the tapered portions 54 are formed in both the left and right directions in the horizontal plane, specifically, they are formed symmetrically. The tapered portion 54 includes a plane having a predetermined angle θ with respect to the central axis C that is perpendicular to the emission surface 52. The predetermined angle θ is appropriately determined according to the incident angle of the remote control signal light 15, which is desired to improve the reach of the remote control signal light 15. A specific example of the method for determining the predetermined angle θ will be described later.

[0023] In this embodiment, as shown in FIG. 4, the second light guide 5b has a rectangular shape in the horizontal plane. That is, the side surface of the second light guide is perpendicular to the emission surface 52 and thus parallel to the central axis. Also, at the boundary 53, the length of the first light guide 5a in the width W direction is the same as the length of the second light guide 5b in the width W direction.

[0024] Next, an example of the predetermined angle θ of the tapered portion 54 will be described. FIG. 5 is a diagram for explaining the angle θ of the tapered portion 54 with respect to the central axis C in the light guide 5 of FIG. 4. FIG. 5 shows an example of the dimensions of the light guide 5. Note that the dimensions shown in FIG. 5 are merely examples. Also, since FIG. 5 is a diagram for explaining an example of the predetermined angle θ of the tapered portion 54, the ratio of the lengths of the respective parts of the light guide 5 shown in FIG. 5 does not necessarily accurately represent the ratio based on the numerical values indicating the dimensions of the respective parts.

[0025] In the example here, as shown in FIG. 5, the length L of the light guide 5 is 20 mm, the length of the first light guide 5a is 4 mm, and the width W of the light guide 5 is 9 mm. Also, the distance from the light emitting surface 52 of the light guide 5 to the light receiving sensor 6 is 2, and at the light receiving sensor 6, the width of the portion where the light receiving element for receiving the light emitted from the light emitting surface 52 of the light guide 5 is arranged is 2 mm.

[0026] The predetermined angle θ can be determined according to the incident angle of the remote control signal light 15 for which it is desired to improve the reach of the remote control signal light 15. For example, assume that the incident angle of the remote control signal light 15 for which it is desired to improve the reach is 30°. In this case, the predetermined angle θ is determined so that the remote control signal light 15 incident on the incident surface 51 of the light guide 5 at an incident angle of 30° is incident on the light receiving element of the light receiving sensor 6 after being emitted from the light emitting surface 52 of the light guide 5.

[0027] When the incident angle of the remote control signal light 15 is 30°, by setting the predetermined angle θ to 6.4°, the signal light can be made incident on the light receiving element of the light receiving sensor 6. That is, the remote control signal light 15 incident on the first optical path LP1 in FIG. 6 is reflected by the side surface of the second light guide 5b and then emitted from the light emitting surface 52 and incident on the light receiving element of the light receiving sensor 6. On the other hand, the remote control signal light 15 incident on the second optical path LP2 in FIG. 6 is reflected by the tapered portion 54 forming the side surface of the first light guide 5a and then further reflected by the side surface of the second light guide 5b and emitted from the light emitting surface 52 and incident on the light receiving element of the light receiving sensor 6.

[0028] Since the tapered portion 54 of the first light guide 5a has an inclination of 6.4° with respect to the central axis C, the angle with respect to the central axis C after the remote control signal light 15 incident on the light guide 5 in the second optical path LP2 is reflected by the tapered portion 54 (referred to as the first angle) is different from the angle with respect to the central axis C after the remote control signal light 15 incident on the light guide 5 in the second optical path LP2 is reflected by the side surface of the light guide 5 when the first light guide 5a does not have the tapered portion 54 and the side surface of the first light guide 5a is parallel to the central axis C (referred to as the second angle). That is, the first angle is larger than the second angle. Therefore, as in this embodiment, the remote control signal light 15 incident on the light guide 5 in the second optical path LP2 is reflected by the tapered portion 54 and then further reflected by the side surface of the second light guide 5b and emitted from the emission surface 52. As a result, the remote control signal light 15 incident in the second optical path LP2 can be incident on the light receiving element of the light receiving sensor 6. If the first light guide 5a does not have the tapered portion 54 and the side surface of the first light guide 5a is parallel to the central axis C, the position where the remote control signal light 15 incident on the light guide 5 in the second optical path LP2 is reflected by one side surface of the light guide 5 and then reflected by the side surface of the light guide 5 for the second time is closer to the emission surface 52. In that case, the light emitted from the emission surface 52 cannot be incident on the light receiving element of the light receiving sensor 6, or even if it can be incident, the amount of incident light is at least reduced. Therefore, the light guide 5 can increase the incidence efficiency of the signal light incident at a specific angle of 30° on the light receiving sensor 6 by having the side surface of the first light guide 5a have the tapered portion 54 as in this embodiment, and thus can improve the reach distance of the signal light incident at a specific angle of 30°. The predetermined angle θ can be determined as an angle that can increase the incidence efficiency of the signal light on the light receiving sensor 6 at a specific angle of 30° in this way.

[0029] For example, assume that the incident angle of the remote control signal light 15 for which it is desired to improve the reach distance is 45°. Also in this case, based on the same concept as in the case where the incident angle is 30° described above, the predetermined angle θ can be determined so that the remote control signal light 15 incident on the incident surface 51 of the light guide 5 at an incident angle of 45° is emitted from the emission surface 52 of the light guide 5 and then incident on the light receiving element of the light receiving sensor 6.

[0030] When the incident angle of the remote control signal light 15 is 45°, by setting the predetermined angle θ to 2.3°, the signal light can be made to enter the light receiving element of the light receiving sensor 6. That is, the remote control signal light 15 incident on the third optical path LP3 in FIG. 7 is reflected by the side surface of the second light guide 5b and then exits from the exit surface 52 and enters the light receiving element of the light receiving sensor 6. On the other hand, the remote control signal light 15 incident on the fourth optical path LP4 in FIG. 7 is reflected by the tapered portion 54 that forms the side surface of the first light guide 5a, then further reflected by the side surface of the second light guide 5b, exits from the exit surface 52, and enters the light receiving element of the light receiving sensor 6.

[0031] Also in this case, similar to the case where the incident angle of the remote control signal light 15 is 30°, the remote control signal light 15 incident on the light guide 5 on the fourth optical path LP4 is reflected by the tapered portion 54 and then further reflected by the side surface of the second light guide 5b and exits from the exit surface 52, whereby it can enter the light receiving element of the light receiving sensor 6. If the first light guide 5a does not have the tapered portion 54 and the side surface of the first light guide 5a is parallel to the central axis C, the remote control signal light 15 incident on the light guide 5 on the fourth optical path LP4 is reflected by one side surface of the light guide 5, and the position where it is reflected by the side surface of the light guide 5 for the second time is closer to the exit surface 52. In that case, the light exiting from the exit surface 52 may not be able to enter the light receiving element of the light receiving sensor 6, or even if it can enter, the amount of light entering is at least reduced. Therefore, by having the side surface of the first light guide 5a have the tapered portion 54 as in this embodiment, the light guide 5 can increase the incidence efficiency of the signal light incident at a specific angle of 45° on the light receiving sensor 6, and thus can improve the reach distance of the signal light incident at a specific angle of 45°. The predetermined angle θ can be determined in this way as an angle that can increase the incidence efficiency of the signal light on the light receiving sensor 6 at a specific angle of 45°.

[0032] Here, the case of the light guide 5 having the shape and dimensions shown in FIG. 5 has been described. However, the predetermined angle θ can be appropriately determined using the above-described concept according to the shape and dimensions of the light guide 5 and the incident angle of the remote control signal light 15 at which it is desired to improve the reach of the remote control signal light 15. For example, in the light guide 5 having the shape and dimensions shown in FIG. 5, if the incident angle of the remote control signal light 15 at which it is desired to improve the reach is in the range of 30° to 45°, the predetermined angle θ can be appropriately determined between 2.3° and 6.4° described above.

[0033] FIG. 8 is a graph showing the relationship between the incident angle of the remote control signal light 15 and the light reception efficiency at the light receiving sensor 6. In the graph of FIG. 8, the horizontal axis represents the incident angle of the remote control signal light 15 on the light guide 5, and the vertical axis represents the light reception efficiency at the light receiving sensor 6. The light reception efficiency at the light receiving sensor 6 is indicated by the effective ratio of the remote control signal light 15 in the light receiving element of the light receiving sensor 6 with the case where the incident angle of the remote control signal light 15 is 0° being 100%.

[0034] In FIG. 8, the plots indicated by circles show the light reception efficiency when the light guide 5 is rectangular, and the plots indicated by triangles show the light reception efficiency when the light guide 5 has the shape described in this embodiment, that is, when the light guide 5 has the tapered portion 54. When the light guide 5 has the shape described in this embodiment, the angle θ of the tapered portion 54 is appropriately determined according to the incident angle of the remote control signal light 15, for example, using the method described above.

[0035] In the example shown in FIG. 8, in the range where the incident angle of the remote control signal light 15 is from 30° to 60°, the light reception efficiency at the light receiving sensor 6 is higher in the case of the shape having the tapered portion 54 as in this embodiment than in the case where the light guide 5 is rectangular. Thus, since the light guide 5 according to this embodiment can increase the incidence efficiency of the remote control signal light 15 to the light receiving sensor 6, the reach of the remote control signal light 15 can be improved.

[0036] (Second Embodiment) FIG. 9 is a cross-sectional view showing a schematic configuration of the light guide 5 according to the second embodiment. In the second embodiment, the configuration of the display device 100 is the same as that of the first embodiment, and the shape of the light guide 5 is different from that of the first embodiment. Hereinafter, the light guide 5 according to the second embodiment will be described focusing on the differences from the first embodiment.

[0037] FIG. 9 shows a horizontal plane obtained by cutting out the light guide 5 according to the second embodiment along the length L direction. That is, the cross-sectional view shown in FIG. 9 corresponds to the cross-sectional view shown in FIG. 4 in the first embodiment. The light guide 5 according to the second embodiment is different from the light guide 5 according to the first embodiment in that the tapered portion 54 includes a plurality of planes having different angles with respect to the central axis C.

[0038] Specifically, the light guide 5 according to the second embodiment includes a tapered portion 54 composed of three tapered elements, namely, a first tapered portion 54a, a second tapered portion 54b, and a third tapered portion 54c. As shown in FIG. 9, the first tapered portion 54a, the second tapered portion 54b, and the third tapered portion 54c are arranged in this order in the direction from the boundary 53 toward the incident surface 51. Further, the first tapered portion 54a, the second tapered portion 54b, and the third tapered portion 54c are each composed of a plane having a first angle θ1, a second angle θ2, and a third angle θ3 with respect to the central axis C. Here, θ1 < θ2 < θ3. That is, the three tapered elements constituting the tapered portion 54 have a larger angle with respect to the central axis C as they are closer to the incident surface 51. Therefore, the opening formed by the tapered portion 54 (that is, the width of the light guide 5) of the light guide 5 increases from the boundary 53 toward the incident surface 51.

[0039] The first angle θ1, the second angle θ2, and the third angle θ3 can be appropriately determined using the method described in the first embodiment. That is, the first angle θ1, the second angle θ2, and the third angle θ3 are appropriately determined according to the incident angle of the remote control signal light 15 for which it is desired to improve the reach distance of the remote control signal light 15. By appropriately determining the first angle θ1, the second angle θ2, and the third angle θ3, based on the same principle as in the first embodiment, the light guide 5 can increase the incident efficiency of the signal light incident from a specific angle to the light receiving sensor 6. In particular, in the second embodiment, since the tapered portion 54 is composed of the first tapered portion 54a, the second tapered portion 54b, and the third tapered portion 54c, by setting the first angle θ1, the second angle θ2, and the third angle θ3 to different angles, the light guide 5 can improve the reach distance for three different incident angles of the remote control signal light 15.

[0040] Note that, in the second embodiment, the case where the tapered portion 54 is composed of three tapered elements, namely the first tapered portion 54a, the second tapered portion 54b, and the third tapered portion 54c, has been described. However, when the tapered portion 54 is configured to include a plurality of tapered elements, the number of the plurality of tapered elements constituting the tapered portion 54 does not necessarily have to be three, and can be any number of two or more. The angle formed by each of the two or more tapered elements and the central axis C becomes larger as it is closer to the incident surface 51, similar to this embodiment. Thereby, the light guide 5 can improve the reach distance for the number of incident angles of the remote control signal light 15 corresponding to the number of tapered elements provided in the tapered portion 54.

[0041] (Third Embodiment) FIG. 10 is a cross-sectional view showing a schematic configuration of the light guide 5 according to the third embodiment. In the third embodiment, the configuration of the display device 100 is the same as that in the first embodiment, and the shape of the light guide 5 is different from that in the first embodiment. Hereinafter, the light guide 5 according to the third embodiment will be described centering on the points different from the first embodiment.

[0042] FIG. 10 shows a horizontal plane obtained by cutting out the light guide 5 according to the third embodiment along the length L direction. That is, the cross-sectional view shown in FIG. 10 corresponds to the cross-sectional view shown in FIG. 4 in the first embodiment. The light guide 5 according to the third embodiment is different from the light guide 5 according to the first embodiment in that the tapered portion 54 is configured to include a curved surface.

[0043] Specifically, as shown in FIG. 10, the tapered portion 54 of the light guide 5 according to the third embodiment includes a curved surface in which the angle with respect to the central axis C increases as it approaches the incident surface 51. That is, in the light guide 5 according to the third embodiment, the opening formed by the tapered portion 54 (that is, the width of the light guide 5) continuously increases from the boundary 53 toward the incident surface 51. In this embodiment, the angle of the tapered portion 54 with respect to the central axis C can be defined as the angle formed by the tangent line at any point of the tapered portion 54 and the central axis C in FIG. 10.

[0044] Since the tapered portion 54 of the light guide 5 according to the third embodiment is configured by a curved surface, the incident efficiency of the signal light incident from a specific range of angles corresponding to the angle of the curved surface with respect to the central axis C, rather than only a specific angle as in the first and second embodiments, can be increased with respect to the light receiving sensor 6.

[0045] Although the present disclosure has been described based on the drawings and embodiments, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these modifications and corrections are included in the scope of the present disclosure. For example, the functions included in each functional unit can be rearranged so as not to be logically contradictory, and a plurality of functional units can be combined into one or divided.

[0046] For example, in FIG. 4, although it has been described that the second light guide 5b has a rectangular shape, the second light guide 5b does not necessarily have a rectangular shape. For example, the boundary surface 53 may have a trapezoidal shape that is longer than the emission surface 52.

[0047] In the above-described embodiment, it was explained that the tapered portion 54 of the first light guide 5a is formed symmetrically about the left and right in the horizontal plane. However, the tapered portion 54 does not necessarily have to be formed symmetrically about the left and right. For example, the angle θ of the tapered portion 54 may be different between the left and right. In this case, the angles at which the reach distance of the signal light can be improved are different in the left-right direction. Also, in this case, the light receiving sensor 6 does not necessarily have to be arranged on the central axis C. For example, it may be arranged shifted in either the left or right direction. That is, the light receiving sensor 6 may be arranged symmetrically or asymmetrically about the central axis C of the light guide 5. For example, in the example shown in FIG. 11, in the horizontal plane, the angle θ1 of the tapered portion on the right side is 6.7°, and the angle θ2 of the tapered portion on the left side is 6.0°. In this case, the light receiving sensor 6 is arranged at a position shifted to the right of the central axis C as shown in FIG. 11 so that it can receive the signal light of the fifth optical path LP5 that is reflected by the tapered portion on the right side after entering from the incident surface 51 and the signal light of the sixth optical path LP6 that is reflected by the tapered portion on the left side after entering from the incident surface 51.

[0048] The tapered portion 54 may be formed on only one of the left and right in the horizontal plane. Even in this case, it is possible to improve the reach distance of the signal light at least in either the left or right direction. Also, the first light guide 5a does not necessarily have to have the tapered portion 54 on the left and right in the horizontal plane. For example, the first light guide 5a may have the tapered portion 54 in the vertical direction on the intersecting surface that intersects the horizontal plane. For example, the first light guide 5a may have the tapered portion 54 in the vertical direction on the vertical plane perpendicular to the horizontal plane. In this case, it is possible to improve the reach distance of the signal light for a specific angle in the vertical direction. Therefore, the first light guide 5a may include the tapered portion 54 in at least either the left-right direction that forms the side surface in the horizontal plane or the vertical direction that forms the side surface in the intersecting surface.

Explanation of Reference Numerals

[0049] 1 Liquid crystal panel 2 Cabinet 3 Light receiving portion 3a Light receiving window 5 Light guide 5a First light guide 5b Second light guide 6 Light receiving sensor 7 Printed circuit board 10 Light receiving device 15 Remote control signal light 51 Incident surface 52 Exit surface 53 Boundary 54 Tapered portion 54a First tapered portion 54b Second tapered portion 54c Third tapered portion 100 Display device

Claims

1. A light guide including a first light guide having an incident surface on which light from the outside is incident and a second light guide having an exit surface from which the light is emitted; A light receiving sensor that receives the light emitted from the exit surface; Comprising; The side surface of the first light guide includes a tapered portion that widens toward the incident surface side, a light receiving device.

2. The light receiving device according to claim 1, wherein the tapered portion includes a plane having a predetermined angle with respect to an axis intersecting the exit surface.

3. The light receiving device according to claim 2, wherein the tapered portion includes a plurality of planes having different angles with respect to the axis.

4. The light receiving device according to claim 1, wherein the tapered portion includes a curved surface whose angle with respect to an axis intersecting the exit surface increases as it gets closer to the incident surface.

5. The light receiving device according to any one of claims 1 to 4, wherein the side surface of the second light guide intersects the exit surface.

6. The light receiving device according to any one of claims 1 to 4, wherein the first light guide includes the tapered portion in at least one of a left-right direction in which the side surface is formed in a horizontal plane and an up-down direction in which the side surface is formed in an intersecting plane intersecting the horizontal plane.

7. The height of the light guide is constant, The light receiving device according to any one of claims 1 to 4, wherein the side surface in the width direction of the first light guide includes the tapered portion.

8. A display device including the light receiving device according to any one of claims 1 to 4 that receives signal light emitted from a remote control device.

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