Light guide component, lighting device, and three-dimensional display device

Abstract

A light guide component, a lighting device, and a three-dimensional display device, capable of realizing a light guide component with a wide emission surface and a short length perpendicular to the emission surface. The light guide component of the present invention includes: an incident surface (21) for light from a light source (13) to be incident, a first reflection surface (23) for reflecting the incident light, a second reflection surface (24) for reflecting the light reflected by the first reflection surface (23) into parallel light, and an emission surface (22) for emitting the parallel light reflected by the second reflection surface (24). The reflection angle (θR) of the first reflection surface (23) is not constant over the first reflection surface (23), and the second reflection surface (24) is a reflection surface with a serrated cross section.

Description

Technical Field

[0001] The present invention relates to a light guide member for emitting parallel light, a lighting device including the light guide member, and a stereoscopic display device including the lighting device. Background Art

[0002] There is known a stereoscopic display device for displaying a so-called three-dimensional image without using viewing glasses. Such a stereoscopic display device includes: a light guide plate; a lighting device provided at an end of the light guide plate for irradiating the light guide plate with light; a left-eye display pattern having a plurality of first prisms formed on the back surface of the light guide plate; and a right-eye display pattern having a plurality of second prisms formed on the back surface of the light guide plate. According to this structure, by reflecting the light from the lighting device by the plurality of first prisms and second prisms, a left-eye image and a right-eye image are displayed on the front surface side of the light guide plate, and an observer can visually recognize a stereoscopic image.

[0003] However, as described above, in a stereoscopic display device, in order to display a stereoscopic image largely, a lighting device for irradiating parallel light to a light guide plate is required. For example, such a lighting device for emitting parallel light is disclosed in Patent Document 1.

[0004] The lighting device disclosed in Patent Document 1 includes a light guide member having an incident surface on which light from a light source is incident, a first reflection surface, a second reflection surface, and an emission surface. The first reflection surface totally reflects at least a part of the light incident from the incident surface, and the second reflection surface totally reflects at least a part of the light totally reflected by the first reflection surface as parallel light. In addition, the emission surface emits the parallel light totally reflected by the second reflection surface.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent No. 6720809

[0008] Problems to be Solved by the Invention

[0009] However, it is difficult to widen the width of the emission surface of the light guide member described in Patent Document 1. In the case where the width of the stereoscopic display device is wide, it is necessary to configure the lighting device by enlarging the light guide member or arranging a plurality of light guide members. Summary of the Invention

[0010] An object of one aspect of the present invention is to realize a light guide member having a wide emission surface (emission region) and a short length (longitudinal length) perpendicular to the emission surface as compared with an existing light guide member.

[0011] In order to solve the above problems, the present invention adopts the following configuration.

[0012] A light guide component according to one embodiment of the present invention includes: an incident surface for incident light from a light source; a first deflection surface for deflecting the light incident from the incident surface; and a second deflection surface for deflecting at least a part of the light deflected by the first deflection surface into parallel light. When the light incident from the incident surface is deflected by the first deflection surface, the deflection angle is not constant over the first deflection surface, and the second deflection surface is a deflection surface with a serrated cross-section.

[0013] According to the above structure, by having a first deflection surface with a non-constant deflection angle of the light incident from the incident surface, the light can be deflected in a diffused manner to a second deflection surface wider than the first deflection surface. Thereby, the light-emitting surface of the light guide component can be enlarged (the lateral length can be increased). In addition, since the second deflection surface is a serrated deflection surface, the length of the light guide component perpendicular to the light-emitting surface (the longitudinal length) can be shortened.

[0014] In a light guide component according to one embodiment of the present invention, the first deflection surface is a curved surface, and the deflection angle continuously changes from one end to the other end of the first deflection surface.

[0015] According to the above structure, the intensity distribution of the light emitted from the light-emitting surface can be made more uniform.

[0016] In a light guide component according to one embodiment of the present invention, the degree of change of the deflection angle changes from one end to the other end of the first deflection surface.

[0017] According to the above structure, the intensity distribution of the light emitted from the light-emitting surface can be uniformly adjusted.

[0018] In addition, according to the second deflection surface of the light guide component according to one embodiment of the present invention, the second deflection surface includes a first point and a second point which are the intersections between the optical path that is incident from the incident surface, deflected by the first deflection surface, and reaches the second deflection surface and the second deflection surface; the optical path length L1 to the first point is shorter than the optical path length L2 to the second point. When the viewing angle of the light-emitting region in the incident surface when observing the first deflection surface along the optical path from the first point is set as θ1, and the viewing angle of the cross-section when observing the first deflection surface from the second point is set as θ2, θ1×L1 < θ2×L2 is satisfied.

[0019] According to the above structure, the uniformity of the intensity distribution of the light emitted from the light-emitting surface can be improved.

[0020] In addition, for each point of the second deflection surface of the light guide component according to one embodiment of the present invention, when the viewing angle of the light-emitting region when observing the first deflection surface from this point is set as θ, and the optical path length of the optical path from the incident surface to this point is set as L, the longer the optical path, the larger θ×L.

[0021] According to the above structure, the uniformity of the intensity distribution of the light emitted from the light-emitting surface can be further improved.

[0022] In addition, in the light guide member according to one embodiment of the present invention, when the viewing angle of the light-emitting region of the incident surface when viewing the first deflection surface from the second deflection surface is θA, the first deflection surface deflects the light incident from the incident surface so that θA is substantially uniform among the respective points on the second deflection surface.

[0023] According to the above structure, the intensity distribution of the light emitted from the light-emitting surface can be made substantially uniform.

[0024] In the light guide member according to one embodiment of the present invention, the first deflection surface includes: a third point located in the optical axis direction of the light incident from the incident surface when viewed from the light-emitting region of the incident surface; and a fourth point located in a direction inclined from the optical axis when viewed from the light-emitting region, and the curvature of the first deflection surface at the fourth point is larger than the curvature of the first deflection surface at the third point.

[0025] According to the above structure, the intensity distribution of the light emitted from the light-emitting surface can be made more uniform.

[0026] In the light guide member according to one embodiment of the present invention, the first deflection surface reflects the light incident from the incident surface, and the deflection angle is the reflection angle when the light incident from the incident surface is reflected by the first deflection surface.

[0027] In addition, in the light guide member according to one embodiment of the present invention, the first deflection surface totally reflects at least a part of the light incident from the incident surface.

[0028] According to the above structure, since total reflection can be performed, it is not necessary to provide a reflective material such as vapor-deposited metal on the first deflection surface. Therefore, the material cost and manufacturing cost of the light guide member can be reduced.

[0029] In addition, in the light guide member according to one embodiment of the present invention, the second deflection surface reflects at least a part of the light deflected by the first deflection surface as parallel light.

[0030] In addition, in the light guide member according to one embodiment of the present invention, the second deflection surface totally reflects at least a part of the light deflected by the first deflection surface as parallel light.

[0031] According to the above structure, since total reflection can be performed, it is not necessary to provide a reflective material such as vapor-deposited metal on the second deflection surface. Therefore, the material cost and manufacturing cost of the light guide member can be reduced.

[0032] One embodiment of the lighting device of the present invention includes the light guide member and the light source. According to the above structure, a compact lighting device can be achieved. In addition, since the light guide member has a wide light emitting surface, the number of light guide members can be reduced compared with the conventional lighting device, and the manufacturing cost of the lighting device can be reduced.

[0033] One embodiment of the stereoscopic display device of the present invention includes: the lighting device; a light guide plate that guides the parallel light emitted from the second deflection surface and forms a stereoscopic image as a real image or a virtual image in space. According to the above structure, the overall size of the stereoscopic display device can be made compact.

[0034] One embodiment of the stereoscopic display device of the present invention includes: the lighting device; a light guide plate that is integrally formed with the light guide member, guides the parallel light emitted from the second deflection surface, and forms a stereoscopic image as a real image or a virtual image in space.

[0035] Advantages of the Invention

[0036] According to one embodiment of the present invention, compared with the conventional light guide member, a light guide member with a wide light emitting surface (emitting area) and a short length (longitudinal length) perpendicular to the light emitting surface can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a perspective view showing the structure of the stereoscopic display device according to Embodiment 1 of the present invention.

[0038] Figure 2 It is a perspective view showing the structure of the lighting device according to Embodiment 1 of the present invention.

[0039] Figure 3 It is a cross-sectional view showing the structure of the light guide member according to Embodiment 1 of the present invention.

[0040] Figure 4 It is a cross-sectional view showing the structure of the light guide member according to Embodiment 1 of the present invention.

[0041] Figure 5 It is Figure 3 an enlarged view of the region R in

[0042] Figure 6 It is a perspective view showing the structure of the light guide member according to Embodiment 2 of the present invention.

[0043] Figure 7 It is a schematic view showing the structure near the incident surface of the light guide member according to Embodiment 2 of the present invention and a modified example of the light guide member.

[0044] Figure 8 It is a perspective view showing the structure of the light guide member according to Embodiment 3 of the present invention.

[0045] Description of the Reference Numerals

[0046] 1: Stereoscopic display device

[0047] 2: Lighting device

[0048] 3: Light guide plate

[0049] 21: Incident surface

[0050] 22: Emission surface

[0051] 13: Light source

[0052] 20, 20A, 20A', 20B: Light guide components

[0053] 23: First reflecting surface

[0054] 24: Second reflecting surface

[0055] L1, L2: Optical path lengths

[0056] θ1, θ2, θA: Viewing angles

[0057] θR: Reflection angle Detailed implementation manners

[0058] Hereinafter, an implementation manner (hereinafter also referred to as "this implementation manner") related to one aspect of the present invention will be described based on the accompanying drawings. However, the implementation manner described below is merely an illustration of the present invention in all aspects. Of course, various improvements and modifications can be made without departing from the scope of the present invention. That is, when implementing the present invention, specific structures corresponding to the implementation manner can also be appropriately adopted.

[0059] (Embodiment 1)

[0060] First, based on Figure 1 the stereoscopic display device 1 according to this embodiment will be described. Figure 1 is a perspective view showing the structure of the stereoscopic display device 1.

[0061] As Figure 1 shown, the stereoscopic display device 1 includes a lighting device 2, a light guide plate 3, and an optical path deflection unit 4.

[0062] The lighting device 2 is a unit for irradiating the light guide plate 3 with light parallel to the direction perpendicular to the incident surface 3a of the light guide plate 3 described later (hereinafter also referred to as parallel light). The detailed structure of the lighting device 2 will be described later.

[0063] The light guide plate 3 is formed of a transparent resin material with a relatively high refractive index. The light guide plate 3 has: an incident surface 3a for incident light irradiated from the lighting device 2; an emission surface 3b which is the surface of the light guide plate 3 for emitting light; and a back surface 3c which is opposite to the emission surface 3b.

[0064] The optical path deflection part 4 is formed on the back surface 3c of the light guide plate 3. The optical path deflection part 4 deflects the guided light and emits it from the light emitting surface 3b of the light guide plate 3. The optical path deflection part 4 is constituted by, for example, a prism.

[0065] In the stereoscopic display device 1, parallel light emitted from the lighting device 2 is incident on the incident surface 3a of the light guide plate 3. The light incident on the light guide plate 3 is guided inside the light guide plate 3, the optical path is deflected by the optical path deflection part 4, and is emitted from the light emitting surface 3b of the light guide plate 3. Then, a stereoscopic image I (stereoscopic image) is spatially formed (imaged) as a real image or a virtual image by the light emitted from the light emitting surface 3b. Regarding the imaging of the stereoscopic image I, a known technique can be used, and thus the description thereof is omitted here.

[0066] (Structure of the lighting device 2)

[0067] Refer to Figures 2 to 5 to describe the structure of the lighting device 2.

[0068] Figure 2 is a perspective view showing the structure of the lighting device 2. Figure 3 and Figure 4 is a sectional view showing the structure of the light guide member 20 housed inside the lighting device 2. In addition, in Figure 3 and Figure 4 the light source 13 is also shown. Figure 5 is Figure 3 an enlarged view of the region R in Figure 3 . Hereinafter, for the sake of convenience of explanation, the X-axis direction in

[0069] is referred to as the horizontal direction, and the Y-axis direction is referred to as the vertical direction. In addition, the +X direction is the right direction, the -X direction is the left direction, the +Y direction is the upper direction, the -Y direction is the lower direction, the +Z direction is the front direction, and the -Z direction is the rear direction for explanation. Figures 2 to 4 As shown in

[0070] The housing 11 is a member for housing the light source 13 and the light guide member 20 inside, and has, for example, a substantially rectangular parallelepiped shape. The housing 11 is formed with an opening 11a at a portion facing the incident surface 3a of the light guide plate 3.

[0071] The light source 13 is a light source that causes light to enter the light guide member 20. The light source 13 is, for example, an LED (Light Emitting Diode) light source. The light source 13 can be a monochromatic LED light source or a combination of three LED light sources that emit red, green, and blue light. When the light source 13 has three-color LED light sources, by adjusting the intensity of the light emitted from each LED light source, various colors of light can be emitted. Therefore, the color of the stereoscopic image I can be changed according to the use.

[0072] The light guide member 20 is a member for converting the light irradiated from the light source 13 into parallel light inside. The light guide member 20 is formed of a resin material having a relatively high refractive index. Refer to Figures 3 to 5 to describe the structure of the light guide member 20.

[0073] As Figure 3 shown, the light guide member 20 has an incident surface 21, an emission surface 22, a first reflection surface 23, and a second reflection surface 24, and has a predetermined thickness in the front-rear direction. The light guide member 20 may further have a first connection surface 201, a second connection surface 202, a third connection surface 203, a fourth connection surface 204, a fifth connection surface 205, and a sixth connection surface 206.

[0074] The incident surface 21 is the surface on which the light emitted from the light source 13 enters the light guide member 20, and is a flat surface. The light emitted from the light source 13 forms a light beam on the incident surface 21. The cross-sectional shape of the light beam with the incident surface 21 as the cross-section can be the shape of the light source 13 when the light source 13 is smaller than the incident surface 21, and can be the shape of the incident surface 21 when the light source 13 is larger than the incident surface 21.

[0075] The emission surface 22 is the surface that emits the light guided inside the light guide member 20, and is a flat surface. The light emitted from the emission surface 22 is irradiated onto the incident surface 3a of the light guide plate 3 through the opening 11a of the housing 11.

[0076] The first reflection surface 23 (first deflection surface) is a surface for reflecting (deflecting) the light emitted from the light source 13 and entering the light guide member 20 from the incident surface 21 toward the second reflection surface 24. As Figure 3 shown, the first reflection surface 23 is configured such that the reflection angle θR (deflection angle) when the light incident from the incident surface 21 is reflected by the first reflection surface 23 is not constant over the first reflection surface 23. With this structure, the first reflection surface 23 can reflect the light in such a manner that the light spreads over the second reflection surface 24 that is wider than the first reflection surface 23.

[0077] For example, the first reflecting surface 23 may be a curved surface that is concave with respect to the incident direction of light incident from the incident surface 21. That is, the shape of the cross-section of the first reflecting surface 23 parallel to the X-Y plane may be a curve that is concave with respect to the incident direction of light incident from the incident surface 21. In addition, the first reflecting surface 23 may be configured such that the reflection angle θR when reflected by the first reflecting surface 23 continuously changes from one end to the other end of the first reflecting surface 23. In other words, the curvature of the first reflecting surface 23 in the cross-section parallel to the X-Y plane may also continuously change from one end to the other end of the first reflecting surface 23. In this case, the curvature of the first reflecting surface 23 may be larger on the side closer to the light source 13, or may also be larger on the side farther from the light source 13. With this structure, it is possible to reduce the interference between the lights reflected at different points on the first reflecting surface 23. That is, it is possible to reduce the generation of stray light. In addition, in this case, the degree of change (rate of change) of the reflection angle θR may also change from one end to the other end of the first reflecting surface 23. In other words, the degree of change (rate of change) of the change in the above-mentioned curvature from one end to the other end of the first reflecting surface 23 may also change from one end to the other end of the first reflecting surface 23. With this structure, it is possible to adjust the intensity distribution of the light emitted from the emission surface 22.

[0078] Here, the viewing angle of the light-emitting region of the incident surface 21 when observing the first reflecting surface 23 from the second reflecting surface 24 is set as θA (refer to Figure 4 ). This light-emitting region may also be the light-emitting surface of the light source 13. That is, the viewing angle θA is the viewing angle of the virtual image of the light-emitting region formed in the incident surface 21 of the first reflecting surface 23 when observing the first reflecting surface 23 from any point in the second reflecting surface 24 in the positive X-axis direction. The first reflecting surface 23 may also be configured to reflect the light incident from the incident surface 21 such that the viewing angle θA is substantially uniform when observed from each point on the second reflecting surface 24. For example, by changing the curvature of the first reflecting surface 23, the viewing angle θA can be adjusted. More specifically, if the curvature of the first reflecting surface 23 is decreased, the viewing angle θA becomes larger, and if the curvature is increased, the viewing angle θA becomes smaller. With this structure, it is possible to improve the uniformity of the intensity distribution of the light emitted from the emission surface 22. When obtaining this effect, if there is a difference of about 10% in the viewing angle θA, it can be regarded as substantially uniform.

[0079] The first reflecting surface 23 may also reflect at least a part of the light incident from the incident surface 21 by total reflection. The amount of light reflected by total reflection depends on the absolute refractive index of the light guide member 20 and the angle of the light incident on the first reflecting surface 23, etc. In the case where the amount of light reflected by total reflection is small, a reflective layer may also be formed on the first reflecting surface 23 by metal evaporation or the like. The formation of this reflective layer is not limited to metal evaporation, and may also be formed by methods such as sputtering or coating.

[0080] In addition, the shape of the cross-section of the first reflecting surface 23 parallel to the X-Y plane may also be a parabola. In this case, by disposing the light source 13 at the focal position of the parabola, the reflected light from the first reflecting surface 23 can be made into parallel light.

[0081] The second reflecting surface 24 (second deflecting surface) is a surface that reflects (deflects) at least a part of the light reflected by the first reflecting surface 23 as parallel light. The second reflecting surface 24 is concave as a whole with respect to the incident direction of the light reflected by the first reflecting surface 23. As Figure 5 shown, the cross-section of the second reflecting surface 24 parallel to the X-Y plane is serrated. For example, as Figure 5 shown, the cross-section of the second reflecting surface 24 parallel to the X-Y plane is stepped, and may also have a discontinuous reflecting surface 241 that reflects the light reflected by the first reflecting surface 23 toward the emitting surface 22 direction as parallel light.

[0082] By the second reflecting surface 24 having the above structure, it is possible to shorten the length (longitudinal length) of the light guide member 20 perpendicular to the emitting surface.

[0083] The second reflecting surface 24 may also reflect at least a part of the light reflected by the first reflecting surface by total reflection. In the case where the amount of light reflected by total reflection is small, a reflecting layer may be formed on the second reflecting surface 24 in the same manner as the first reflecting surface 23, such as by metal evaporation.

[0084] Here, with reference to Figure 4 , the relationship between the optical path length of the second reflecting surface 24 of the light guide member 20 of the present invention and the viewing angle θA will be described. As Figure 4 shown, the second reflecting surface 24 includes on its surface the intersection points of the optical path that enters from the incident surface 21 and is reflected by the above-mentioned first reflecting surface and reaches the second reflecting surface, namely the first point and the second point. Here, the optical path length L1 to the first point is shorter than the optical path length L2 to the second point.

[0085] Let the viewing angle θA of the cross-section of the light beam incident from the incident surface 21 when observing the first reflecting surface 23 along the optical path from the first point be the viewing angle θ1, and let the viewing angle θA of this cross-section when observing the first reflecting surface 23 along the optical path from the second point be the viewing angle θ2. At this time, the light guide member 20 satisfies θ1 × L1 < θ2 × L2. With this structure, it is possible to improve the uniformity of the intensity distribution of the light emitted from the emitting surface.

[0086] In addition, the first reflecting surface 23 includes a third point in the optical axis direction of the light source 13 (in the light-emitting region) when viewed from the light source 13 (the center of the light-emitting region in the incident surface 21), and a fourth point in a direction inclined from the optical axis of the light source 13 when viewed from the light source 13. At a position of the first reflecting surface 23 far from (inclined from) the optical axis, the apparent area of the light source appears smaller. The curvature of the first reflecting surface 23 at the fourth point can be larger than the curvature of the first reflecting surface 23 at the third point. With this structure, the uniformity of the intensity distribution of the light emitted from the light-emitting surface can be improved. For example, the optical axis of the light source 13 is an axis perpendicular to the light-emitting surface of the light source 13.

[0087] As Figure 3 shown, in the light guide member 20, the lower end of the first reflecting surface 23 and the right end of the incident surface 21 may also be connected by a first connecting surface 201 that becomes a plane. The lower end of the second reflecting surface 24 may have the same coordinate in the X-axis direction as the right end of the light-emitting surface 22, and the same coordinate in the Y-axis direction as the lower end of the first reflecting surface. The lower end of the second reflecting surface 24 may also be connected to the left end of a third connecting surface 203 that is a plane parallel to the light-emitting surface 22. The right end of the third connecting surface 203 may also be connected to the left end of a second connecting surface 202 that is a plane connected to the left end of the incident surface 21. The right end of the second connecting surface 202 may also be connected to the left end of the incident surface 21. The left end of the light-emitting surface 22 and the upper end of the second reflecting surface 24 may also be connected by a sixth connecting surface 206 that is a plane perpendicular to the light-emitting surface 22. The upper end of the first reflecting surface 23 and the upper end of the second reflecting surface 24 may have the same coordinate in the Y-axis direction, and may also be connected to one end of a fourth connecting surface 204 that is a plane parallel to the light-emitting surface 22. The other end of the fourth connecting surface 204 may also be connected to the right end of the light-emitting surface 22 and connected to a fifth connecting surface 205 that is a plane perpendicular to the light-emitting surface 22.

[0088] In addition, the positions of the ends of the first reflecting surface 23 and the second reflecting surface 24 are not limited to the above manner. The shape of the connecting surface that connects the incident surface 21, the first reflecting surface 23, the second reflecting surface 24, and the light-emitting surface 22, the angle with respect to each surface, etc. may also be appropriately changed according to the incident surface 21, the first reflecting surface 23, the second reflecting surface 24, and the light-emitting surface 22.

[0089] In addition, the light guide plate 3 and the light guide member 20 may also be integrally formed.

[0090] (Embodiment 2)

[0091] Other embodiments of the present invention will be described below. In addition, for the sake of convenience of explanation, components having the same functions as those described in the above embodiments are denoted by the same reference numerals, and their descriptions are not repeated. The same applies to the following embodiments.

[0092] (Structure of the light guide member 20A)

[0093] Figure 6 FIG. is a perspective view showing the structure of the light guide member 20A as another embodiment of the present invention. The difference between the light guide member 20A and the light guide member 20 of the first embodiment is that it has a bent portion 29A. The bent portion 29A is provided between the first reflecting surface 23 and the second reflecting surface 24. In addition, as Figure 6 shown, in order to avoid stray light, on at least a part of the surface of the bent portion 29A connecting the first reflecting surface 23 and the second reflecting surface 24, a cutout portion 60A having a plurality of cutout shapes may be formed.

[0094] By having the bent portion 29A, the lateral length of the light guide member 20A can be shortened.

[0095] Figure 7 FIG. is a schematic view of the structure near the incident surface 21 of the light guide member 20A and the light guide member 20A' which is a modified example of the light guide member 20A. In Figure 7 FIG., the figure indicated by reference numeral 701 is a schematic view of the light guide member 20A, and the figure indicated by reference numeral 702 is a schematic view of the light guide member 20A'. Figure 7 The light guide member 20A' indicated by reference numeral 702 in FIG. has a third reflecting surface 25 between the incident surface 21 and the first reflecting surface for reflecting the light incident from the incident surface 21 toward the first reflecting surface 23. By having the third reflecting surface 25, the length in the depth direction as shown in Figure 6 FIG. can be further shortened.

[0096] (Embodiment 3)

[0097] (Structure of the light guide member 20B)

[0098] Figure 8 FIG. is a perspective view showing the structure of the light guide member 20B as another embodiment of the present invention. In addition, in Figure 8 FIG., for the sake of easy understanding, the light guide plate 3 is also shown. The difference between the light guide member 20B and the light guide member of the first embodiment is that it has a bent portion 29A and a bent portion 29B. The bent portion 29B is provided between the second reflecting surface 24 and the emitting surface 22. In addition, as Figure 7 shown, in order to avoid stray light, on at least a part of the surface connecting the emitting surface 22 and the incident surface 21, a cutout portion 60C having a plurality of cutout shapes may be formed.

[0099] By having the bent portion 29A and the bent portion 29B, the light guide member 20B can be arranged in the side or back direction of the light guide plate 3.

[0100] The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope indicated by the claims. Embodiments obtained by appropriately combining technical means separately disclosed in different embodiments are also included in the technical scope of the present invention.

Claims

1. A light guide component, characterized in that, it comprises: an incident surface that incident light from a light source; a first deflection surface that deflects the light incident from the incident surface; a second deflection surface that deflects at least a part of the light deflected by the first deflection surface into parallel light, when the light incident from the incident surface is deflected by the first deflection surface, the deflection angle is not constant over the first deflection surface, the second deflection surface is a deflection surface with a serrated cross-section, the second deflection surface includes a first point and a second point which are the intersection points between the optical path that is incident from the incident surface, deflected by the first deflection surface and reaches the second deflection surface and the second deflection surface, the optical path length L1 from the incident surface to the first point is shorter than the optical path length L2 from the incident surface to the second point, when the viewing angle of the light-emitting region in the incident surface when observing the first deflection surface along the optical path from the first point is set as θ1, and the viewing angle of the light-emitting region when observing the first deflection surface from the second point is set as θ2, θ1×L1 < θ2×L2 is satisfied.

2. The light guide component according to claim 1, characterized in that, the first deflection surface is a curved surface, and the deflection angle continuously changes from one end to the other end of the first deflection surface.

3. The light guide component according to claim 2, characterized in that, the degree of change of the deflection angle changes from one end to the other end of the first deflection surface.

4. The light guide component according to claim 1, characterized in that, among the points of the second deflection surface, when the viewing angle of the light-emitting region when observing the first deflection surface from this point is set as θ, and the optical path length of the optical path from the incident surface to this point is set as L, the longer the optical path, the larger θ×L.

5. The light guide component according to any one of claims 1 to 3, characterized in that, when the viewing angle of the light-emitting region of the incident surface when observing the first deflection surface from the second deflection surface is θA, the first deflection surface deflects the light incident from the incident surface so that θA is substantially uniform among the points on the second deflection surface.

6. The light guide component according to any one of claims 1 to 3, characterized in that, the first deflection surface includes: a third point located on the optical axis direction of the light incident from the incident surface when observing from the light-emitting region of the incident surface; a fourth point located in a direction inclined from the optical axis when observing from the light-emitting region, the curvature of the first deflection surface at the fourth point is larger than the curvature of the first deflection surface at the third point.

7. The light guide component according to any one of claims 1 to 3, characterized in that, the first deflection surface reflects the light incident from the incident surface, the deflection angle is the reflection angle when the light incident from the incident surface is reflected by the first deflection surface.

8. The light guide component according to claim 7, characterized in that, the first deflection surface totally reflects at least a part of the light incident from the incident surface.

9. The light guide component according to any one of claims 1 to 3, characterized in that, The second deflection surface reflects at least a part of the light deflected by the first deflection surface as parallel light.

10. The light guide member according to claim 9, characterized in that the second deflection surface totally reflects at least a part of the light deflected by the first deflection surface as parallel light.

11. An illumination device, characterized in that it comprises: the light guide member according to any one of claims 1 to 10; the light source.

12. A stereoscopic display device, characterized in that it comprises: the illumination device according to claim 11; a light guide plate that guides the parallel light emitted from the second deflection surface and forms a stereoscopic image as a real image or a virtual image in space.

13. A stereoscopic display device, characterized in that it comprises: the illumination device according to claim 11; a light guide plate that is integrally formed with the light guide member, guides the parallel light emitted from the second deflection surface, and forms a stereoscopic image as a real image or a virtual image in space.

Images