Light guide member, lighting device and stereoscopic display device

Abstract

To realize a light guide member having a wide emission surface and a short length perpendicular to the emission surface.SOLUTION: A light guide member comprises: an incident surface (21) on which light from a light source (13) is made incident; a first reflection surface (23) that reflects incident light; a second reflection surface (24) that reflects the light reflected by the first reflection surface (23) as parallel light; and an emission surface (22) that emits the parallel light reflected by the second reflection surface (24). A reflection angle (θR) at the first reflection surface (23) is not constant over the first reflection surface (23), and the second reflection surface (24) has a serrated cross section.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a light guiding member for emitting parallel light, an illumination device including the light guiding member, and a stereoscopic display device including the illumination device. [Background technology]

[0002] There is known a stereoscopic display device for displaying so-called three-dimensional images without using glasses for observation. Such a stereoscopic display device includes a light guide plate, an illumination 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 rear surface of the light guide plate, and a right-eye display pattern having a plurality of second prisms formed on the rear surface of the light guide plate. With this configuration, the light from the illumination device is reflected by the plurality of first prisms and the second prism, so that 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 view a stereoscopic image.

[0003] As described above, in order to display a large stereoscopic image in a stereoscopic display device, an illumination device for irradiating parallel light onto a light guide plate is required. An illumination device for emitting such parallel light is disclosed in, for example, 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 reflecting surface, a second reflecting surface, and an exit surface. The first reflecting surface totally reflects at least a part of the light incident from the incident surface, and the second reflecting surface totally reflects at least a part of the light totally reflected by the first reflecting surface as parallel light. The exit surface emits the parallel light totally reflected by the second reflecting surface. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6720809 Summary of the Invention [Problem to be solved by the invention]

[0006] However, it is difficult to increase the width of the exit surface of the light-guiding member described in Patent Document 1, and when the width of the stereoscopic display device is wide, it is necessary to configure the illumination device by increasing the size of the light-guiding member or arranging a large number of light-guiding members.

[0007] An aspect of the present invention aims to realize a light-guiding member having a wider emission surface (emission region) and a shorter length perpendicular to the emission surface (length in the vertical direction) compared to conventional light-guiding members. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the present invention employs the following configuration.

[0009] A light-guiding member according to one embodiment of the present invention comprises an incident surface on which light from a light source is incident, a first deflection surface which deflects the light incident from the incident surface, and a second deflection surface which deflects at least a portion of the light deflected by the first deflection surface as parallel light, wherein the deflection angle when the light incident from the incident surface is deflected by the first deflection surface is not constant across the first deflection surface, and the second deflection surface is a deflection surface having a saw-like cross section.

[0010] With the above configuration, by having a first deflection surface where the deflection angle of light incident from the entrance surface is not constant, the light can be deflected so as to spread to a second deflection surface that is wider than the first deflection surface. This allows the exit surface of the light guide member to be wider (the horizontal length longer). In addition, by having the second deflection surface be a sawtooth deflection surface, the length of the light guide member perpendicular to the exit surface (the vertical length) can be shortened.

[0011] In the light-guiding member according to one aspect of the present invention, the first deflection surface is a curved surface, and the deflection angle changes continuously from one end to the other end of the first deflection surface.

[0012] With the above configuration, the intensity distribution of the light emitted from the exit surface can be made more uniform.

[0013] In the light-guiding member according to one aspect of the present invention, the degree of change in the deflection angle varies from one end to the other end of the first deflection surface.

[0014] With the above configuration, the intensity distribution of the light emitted from the exit surface can be adjusted to be uniform.

[0015] Furthermore, the second deflection surface of the light-guiding member according to one embodiment of the present invention includes a first point and a second point which are the intersection points between the second deflection surface and an optical path in which light enters from the incident surface, is deflected by the first deflection surface, and reaches the second deflection surface, and an optical path length L1 to the first point is shorter than an optical path length L2 to the second point, and when a viewing angle of the light-emitting region on the incident surface when viewing the first deflection surface along the optical path from the first point is θ1 and a viewing angle of the cross section when viewing the first deflection surface from the second point is θ2, θ1×L1<θ2×L2 is satisfied.

[0016] With the above configuration, it is possible to improve the uniformity of the intensity distribution of the light emitted from the exit surface.

[0017] Furthermore, at each point on the second deflection surface of the light-guiding member according to one embodiment of the present invention, when the first deflection surface is viewed from that point, the visual angle of the light-emitting region is θ, and the optical path length of the optical path from the incident surface to that point is L, then the longer the optical path, the larger θ×L becomes.

[0018] With the above configuration, it is possible to further improve the uniformity of the intensity distribution of the light emitted from the exit surface.

[0019] In addition, in a light-guiding member according to one embodiment of the present invention, when the viewing angle of the light-emitting region when looking at the first deflection surface from the second deflection surface is θA, the first deflection surface deflects the light incident from the entrance surface so that θA is approximately uniform at each point on the second deflection surface.

[0020] With the above configuration, the intensity distribution of the light emitted from the exit surface can be made substantially uniform.

[0021] In addition, in a light-guiding member according to one embodiment of the present invention, the first deflection surface includes a third point that is in the direction of the optical axis of light incident from the incident surface when viewed from the light-emitting area on the incident surface, and a fourth point that is in a direction tilted from the optical axis when viewed from the light-emitting area, and the curvature of the first deflection surface at the fourth point is greater than the curvature of the first deflection surface at the third point.

[0022] With the above configuration, the intensity distribution of the light emitted from the exit surface can be made more uniform.

[0023] In addition, in a light-guiding member according to one aspect of the present invention, the first deflection surface may reflect light incident from the incident surface, and the deflection angle may be a reflection angle when the light incident from the incident surface is reflected by the first deflection surface.

[0024] In the light-guiding member according to the aspect of the present invention, the first deflection surface totally reflects at least a part of the light incident on the entrance surface.

[0025] With the above configuration, total reflection can be achieved, so there is no need to provide a reflective material such as a vapor-deposited metal on the first deflection surface, and therefore the material costs and manufacturing costs of the light-guiding member can be reduced.

[0026] In the light-guiding member according to the aspect of the present invention, the second deflecting surface may reflect at least a part of the light deflected by the first deflecting surface as parallel light.

[0027] In the light-guiding member according to the aspect of the present invention, the second deflecting surface totally reflects at least a part of the light deflected by the first deflecting surface as parallel light.

[0028] With the above configuration, total reflection can be achieved, so there is no need to provide a reflective material such as a vapor-deposited metal on the second deflection surface, which reduces the material cost and manufacturing cost of the light-guiding member.

[0029] The lighting device according to one aspect of the present invention includes the light guide member and a light source. According to the above configuration, a compact lighting device can be realized. In addition, since the light guide member has a wide emission surface, the number of light guide members can be reduced compared to conventional lighting devices, and the manufacturing cost of the lighting device can be reduced.

[0030] According to an embodiment of the present invention, there is provided a stereoscopic display device including the above-described illumination device and a light guide plate that receives the parallel light emitted from the second deflection surface and forms a stereoscopic image in space as a real image or a virtual image. With the above configuration, the size of the entire stereoscopic display device can be made compact.

[0031] A stereoscopic display device according to one embodiment of the present invention includes the above-described illumination device and a light guide plate formed integrally with the light guide member, into which the parallel light emitted from the second deflection surface is introduced to form a stereoscopic image in space as a real image or a virtual image. Effect of the Invention

[0032] According to one aspect of the present invention, it is possible to realize a light guide member having a wide emission surface (emission region) and a short length perpendicular to the emission surface (length in the vertical direction) compared to conventional light guide members. [Brief description of the drawings]

[0033] [Figure 1] 1 is a perspective view showing a configuration of a stereoscopic display device according to a first embodiment of the present invention. [Diagram 2] 1 is a perspective view showing a configuration of an illumination device according to a first embodiment of the present invention. [Diagram 3] 1 is a cross-sectional view illustrating a structure of a light-guiding member according to a first embodiment of the present invention. [Figure 4] 1 is a cross-sectional view illustrating a structure of a light-guiding member according to a first embodiment of the present invention. [Diagram 5] FIG. 4 is an enlarged view of a region R in FIG. [Figure 6] FIG. 11 is a perspective view showing a configuration of a light-guiding member according to a second embodiment of the present invention. [Figure 7] 10A and 10B are schematic diagrams illustrating configurations near an incident surface of a light-guiding member according to a second embodiment of the present invention and a modified example of the light-guiding member. [Figure 8] FIG. 11 is a perspective view showing a configuration of a light guide member according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] Hereinafter, an embodiment according to one aspect of the present invention (hereinafter, also referred to as "the present embodiment") will be described with reference to the drawings. However, the present embodiment described below is merely an example of the present invention in every respect. It goes without saying that various improvements and modifications can be made without departing from the scope of the present invention. In other words, in implementing the present invention, a specific configuration according to the embodiment may be appropriately adopted.

[0035] [Embodiment 1] First, a stereoscopic display device 1 according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a perspective view showing the configuration of the stereoscopic display device 1.

[0036] As shown in FIG. 1, the stereoscopic display device 1 includes an illumination device 2, a light guide plate 3, and an optical path deflection section 4.

[0037] The lighting device 2 is a unit for irradiating the light guide plate 3 with parallel light (hereinafter also referred to as parallel light) in a direction perpendicular to an incident surface 3a of the light guide plate 3 described later. The configuration of the lighting device 2 will be described in detail later.

[0038] The light guide plate 3 is made of a transparent resin material with a relatively high refractive index. The light guide plate 3 has an incident surface 3a on which the light irradiated from the lighting device 2 enters, an exit surface 3b which is the front surface of the light guide plate 3 and from which the light exits, and a back surface 3c opposite to the exit surface 3b.

[0039] The optical path deflection unit 4 is formed on the rear surface 3c of the light guide plate 3. The optical path deflection unit 4 deflects the optical path of the guided light and causes it to exit from the exit surface 3b of the light guide plate 3. The optical path deflection unit 4 is formed of, for example, a prism.

[0040] In the stereoscopic display device 1, parallel light emitted from the illumination device 2 is incident on the light guide plate 3 from the incident surface 3a. The light incident on the light guide plate 3 is guided inside the light guide plate 3, its optical path is deflected by the optical path deflection unit 4, and the light is emitted from the exit surface 3b of the light guide plate 3. Then, a stereoscopic image I (stereoscopic image) is formed (imaging) in space as a real image or a virtual image by the light emitted from the exit surface 3b. The imaging of the stereoscopic image I can be achieved by using known technology, and therefore a description thereof will be omitted here.

[0041] (Configuration of lighting device 2) The configuration of the lighting device 2 will be described with reference to FIGS.

[0042] FIG. 2 is a perspective view showing the configuration of the lighting device 2. FIGS. 3 and 4 are cross-sectional views showing the structure of the light guide member 20 stored inside the lighting device 2. Note that in FIGS. 3 and 4, the light source 13 is also shown. FIG. 5 is an enlarged view of a region R in FIG. 3. Hereinafter, for convenience of explanation, the X-axis direction in FIG. 3 will be referred to as the horizontal direction, and the Y-axis direction as the vertical direction. In addition, the +X direction will be referred to as the right direction, the -X direction as the left direction, the +Y direction as the upward direction, the -Y direction as the downward direction, the +Z direction as the forward direction, and the -Z direction as the backward direction.

[0043] 2 to 4, the lighting device 2 includes a housing 11, a light guide member 20, and a light source 13. The lighting device 2 also includes a board (not shown) on which the light source 13 is mounted.

[0044] The housing 11 is a member for storing the light source 13 and the light guide member 20 therein, and has, for example, a substantially rectangular parallelepiped shape. The housing 11 has an opening 11a formed in a position facing the incident surface 3a of the light guide plate 3.

[0045] The light source 13 is a light source that causes light to enter the light-guiding member 20. The light source 13 is, for example, an LED (Light Emitting Diode) light source. The light source 13 may be a single-color LED light source or a combination of three types of LED light sources that emit red, green, and blue. When the light source 13 has three-color LED light sources, it is possible to emit light of various colors by adjusting the intensity of the light emitted from each LED light source. This allows the color of the stereoscopic image I to be changed depending on the application.

[0046] The light guide member 20 is a member for converting the light emitted from the light source 13 into parallel light inside the light guide member 20. The light guide member 20 is molded from a resin material having a relatively high refractive index. The structure of the light guide member 20 will be described with reference to Figs. 3 to 5.

[0047] 3, the light-guiding member 20 has an incident surface 21, an exit surface 22, a first reflecting surface 23, and a second reflecting surface 24, and has a predetermined thickness in the front-rear direction. The light-guiding member 20 may also have a first connecting surface 201, a second connecting surface 202, a third connecting surface 203, a fourth connecting surface 204, a fifth connecting surface 205, and a sixth connecting surface 206.

[0048] The incident surface 21 is a flat surface through which the light emitted from the light source 13 enters the light-guiding member 20. The light emitted from the light source 13 forms a light flux at the incident surface 21. The cross-sectional shape of the light flux, taken along the incident surface 21, may be the shape of the light source 13 when the light source 13 is smaller than the incident surface 21, or may be the shape of the incident surface 21 when the light source 13 is larger than the incident surface 21.

[0049] The exit surface 22 is a flat surface that emits light that has been guided inside the light-guiding member 20. The light emitted from the exit surface 22 is irradiated onto the incident surface 3a of the light guide plate 3 through the opening 11a of the housing 11.

[0050] The first reflecting surface 23 (first deflection surface) is a surface for reflecting (deflecting) the light emitted from the light source 13 and incident on the light-guiding member 20 from the incident surface 21, toward the second reflecting surface 24. As shown in Fig. 3, the first reflecting surface 23 is configured such that the reflection angle θR (deflection angle) when the light incident on the incident surface 21 is reflected by the first reflecting surface 23 is not constant across the first reflecting surface 23. With this configuration, the first reflecting surface 23 can reflect the light so that the light spreads across the second reflecting surface 24, which is wider than the first reflecting surface 23.

[0051] For example, the first reflecting surface 23 may be a curved surface that is concave with respect to the incident direction of the light incident from the incident surface 21. That is, the shape of the cross section of the first reflecting surface 23 parallel to the XY plane may be a curve that is concave with respect to the incident direction of the light incident from the incident surface 21. The first reflecting surface 23 may be configured such that the reflection angle θR when reflected by the first reflecting surface 23 changes continuously 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 XY plane may change continuously 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 closer to the light source 13, or may be larger farther from the light source 13. With this configuration, it is possible to reduce interference between lights reflected at different points on the first reflecting surface 23. That is, it is possible to reduce the occurrence of stray light. In this case, the degree of change (rate of change) of the reflection angle θR may change from one end to the other end of first reflecting surface 23. In other words, the degree of change (rate of change) of the change in curvature from one end to the other end of first reflecting surface 23 may change from one end to the other end of first reflecting surface 23. With this configuration, the intensity distribution of the light emitted from exit surface 22 can be adjusted.

[0052] Here, the viewing angle of the light emitting area on the incident surface 21 when the first reflecting surface 23 is viewed from the second reflecting surface 24 is θA (see FIG. 4). The light emitting area may be the light emitting surface of the light source 13. That is, the viewing angle θA is the viewing angle of a virtual image of the light emitting area on the incident surface 21 formed on the first reflecting surface 23 when the first reflecting surface 23 is viewed in the positive direction of the X-axis from any one point on the second reflecting surface 24. The first reflecting surface 23 may be configured to reflect the light incident from the incident surface 21 so that the viewing angle θA when viewed from each point on the second reflecting surface 24 is approximately uniform. For example, the viewing angle θA can be adjusted by changing the curvature of the first reflecting surface 23. More specifically, when the curvature of the first reflecting surface 23 is reduced, the viewing angle θA increases, and when the curvature is increased, the viewing angle θA decreases. This configuration can improve the uniformity of the intensity distribution of the light emitted from the exit surface 22. To obtain this effect, the viewing angle θA can be considered to be approximately uniform if the difference is about 10%.

[0053] The first reflecting surface 23 may 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-guiding member 20 and the angle of light incident on the first reflecting surface 23, etc. When the amount of light reflected by total reflection is small, a reflective layer may be formed on the first reflecting surface 23 by metal vapor deposition or the like. The formation of the reflective layer is not limited to metal vapor deposition, and may be formed by a technique such as sputtering or painting.

[0054] The first reflecting surface 23 may have a cross section parallel to the XY plane that is a parabola. In this case, the light source 13 is disposed at the focal point of the parabola, so that the reflected light from the first reflecting surface 23 can be made into a parallel light.

[0055] 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 generally concave with respect to the incident direction of the light reflected from the first reflecting surface 23. As shown in FIG. 5, the second reflecting surface 24 has a sawtooth cross section parallel to the XY plane. For example, as shown in FIG. 5, the cross section of the second reflecting surface 24 parallel to the XY plane may have a stepped shape and may have a discontinuous reflecting surface 241 that reflects the light reflected from the first reflecting surface 23 as parallel light toward the exit surface 22.

[0056] By providing the second reflecting surface 24 with the above-described configuration, the length of the light guide member 20 perpendicular to the emission surface (the length in the vertical direction) can be shortened.

[0057] The second reflecting surface 24 may reflect at least a part of the light reflected by the first reflecting surface by total reflection. If the amount of light reflected by total reflection is small, a reflective layer may be formed on the second reflecting surface 24 by metal deposition or the like, as with the first reflecting surface 23.

[0058] Here, the relationship between the optical path length at the second reflecting surface 24 of the light guide member 20 of the present invention and the viewing angle θA will be described with reference to Fig. 4. As shown in Fig. 4, the second reflecting surface 24 includes a first point and a second point on its surface, which are the intersections between the second reflecting surface and an optical path that enters from the incident surface 21, is reflected by the first reflecting surface, and reaches the second reflecting surface. Here, the optical path length L1 to the first point is shorter than the optical path length L2 to the second point.

[0059] When the first reflecting surface 23 is viewed from the first point along the optical path, Illumination area The visual angle θA is the visual angle θ1, and the visual angle θ2 is the visual angle θ3 when the first reflecting surface 23 is viewed along the optical path from the second point. Illumination area The viewing angle θA of the light guide member 20 is defined as the viewing angle θ2. In this case, the light guide member 20 satisfies θ1×L1<θ2×L2. This configuration can improve the uniformity of the intensity distribution of the light emitted from the exit surface.

[0060] The first reflecting surface 23 includes a third point located in the direction of the optical axis of the light source 13 (light emitting region) as viewed from the light source 13 (the center of the light emitting region on the entrance surface 21), and a fourth point located in a direction tilted from the optical axis of the light source 13 as viewed from the light source 13. At a position away from (tilted from) the optical axis on the first reflecting surface 23, the apparent area of ​​the light source appears smaller. The curvature of the first reflecting surface 23 at the fourth point may be larger than the curvature of the first reflecting surface 23 at the third point. This configuration can improve the uniformity of the intensity distribution of the light emitted from the exit surface. For example, the optical axis of the light source 13 is an axis perpendicular to the light emitting surface of the light source 13.

[0061] As shown in FIG. 3, 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 be connected by a first connecting surface 201 that is 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 exit 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 exit surface 22. The right end of the third connecting surface 203 may 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 be connected to the left end of the incident surface 21. The left end of the exit surface 22 and the upper end of the second reflecting surface 24 may be connected by a sixth connecting surface 206 that is a plane perpendicular to the exit surface 22. The upper end of first reflecting surface 23 has the same coordinate in the Y-axis direction as the upper end of second reflecting surface 24, and may be connected to one end of fourth connecting surface 204, which is a plane parallel to exit surface 22. The other end of fourth connecting surface 204 is connected to the right end of exit surface 22, and may be connected to fifth connecting surface 205, which is a plane perpendicular to exit surface 22.

[0062] The positions of the ends of first reflecting surface 23 and second reflecting surface 24 are not limited to the above. The shapes of the connecting surfaces connecting incident surface 21, first reflecting surface 23, second reflecting surface 24, and exit surface 22, the angles relative to each surface, and the like can also be changed appropriately depending on incident surface 21, first reflecting surface 23, second reflecting surface 24, and exit surface 22.

[0063] The light guide plate 3 and the light guide member 20 may be integrally formed.

[0064] [Embodiment 2] Other embodiments of the present invention will be described below. For the sake of convenience, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated. The same applies to the following embodiments.

[0065] (Configuration of light guide member 20A) Fig. 6 is a perspective view showing a configuration of a light guiding member 20A according to another embodiment of the present invention. The light guiding member 20A differs from the light guiding member 20 according to the first embodiment in that the light guiding member 20A has a bent portion 29A. The bent portion 29A is provided between the first reflecting surface 23 and the second reflecting surface 24. As shown in Fig. 6, a cutout portion 60A having a plurality of cutout shapes may be formed in at least a part of the surface of the bent portion 29A that connects the first reflecting surface 23 and the second reflecting surface 24 in order to allow stray light to escape.

[0066] By providing the bent portion 29A, the lateral length of the light guide member 20A can be shortened.

[0067] 7 is a schematic diagram of the configuration of the light guide member 20A and the light guide member 20A' as a modified example of the light guide member 20A near the incident surface 21. In FIG. 7, the diagram indicated by reference numeral 701 is a schematic diagram of the light guide member 20A, and the diagram indicated by reference numeral 702 is a schematic diagram of the light guide member 20A'. The light guide member 20A' indicated by reference numeral 702 in FIG. 7 has a third reflecting surface 25 between the incident surface 21 and the first reflecting surface, which reflects 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 shown in FIG. 6 can be made shorter.

[0068] [Embodiment 3] (Configuration of light guide member 20B) FIG. 8 is a perspective view showing a configuration of a light guide member 20B according to another embodiment of the present invention. For the sake of understanding, FIG. 8 also shows a light guide plate 3. The light guide member 20B is different from the light guide member of the first embodiment in 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 exit surface 22. As shown in FIG. 7, a cutout portion 60C having a plurality of cutout shapes may be formed in at least a part of the surface connecting the exit surface 22 and the entrance surface 21 to allow stray light to escape.

[0069] By providing the bent portions 29A and 29B, the light guide member 20B can be disposed along the side surface or rear surface of the light guide plate 3. As shown in FIG.

[0070] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0071] 1 3D display device 2. Lighting equipment 3 Light guide plate 21 Entrance plane 22 Exit surface 13 Light source 20, 20A, 20A', 20B Light guide member 23 1st reflective surface 24 Second reflective surface L1, L2 optical path length θ1, θ2, θA Visual angle θR reflection angle

Claims

1. An incident surface on which light from a light source is incident; a first deflection surface that deflects light incident on the entrance surface; a second deflection surface that deflects at least a portion of the light deflected by the first deflection surface as parallel light, a deflection angle when the light incident on the entrance surface is deflected by the first deflection surface is not constant across the first deflection surface, the second deflection surface is a deflection surface having a sawtooth cross section, the second deflection surface includes a first point and a second point which are intersections between the second deflection surface and an optical path that is incident on the entrance surface, is deflected by the first deflection surface, and reaches the second deflection surface, an optical path length L1 to the first point is shorter than an optical path length L2 to the second point; A light-guiding member that satisfies θ1×L1<θ2×L2, where θ1 is the viewing angle of the light-emitting area on the incident surface when the first deflection surface is viewed from the first point along the optical path, and θ2 is the viewing angle of the light-emitting area on the incident surface when the first deflection surface is viewed from the second point.

2. An incident surface on which light from a light source is incident; a first deflection surface that deflects light incident on the entrance surface; a second deflection surface that deflects at least a portion of the light deflected by the first deflection surface as parallel light, a deflection angle when the light incident on the entrance surface is deflected by the first deflection surface is not constant across the first deflection surface, the second deflection surface is a deflection surface having a sawtooth cross section, A light-guiding member in which, when the viewing angle of the light-emitting area on the incident surface when looking at the first deflection surface from the second deflection surface is θA, the first deflection surface deflects light incident from the incident surface so that θA is approximately uniform at each point on the second deflection surface.

3. An incident surface on which light from a light source is incident; a first deflection surface that deflects light incident on the entrance surface; a second deflection surface that deflects at least a portion of the light deflected by the first deflection surface as parallel light, a deflection angle when the light incident on the entrance surface is deflected by the first deflection surface is not constant across the first deflection surface, the second deflection surface is a deflection surface having a sawtooth cross section, The first deflection surface is a third point located in a direction of an optical axis of light incident from the incident surface as viewed from a light emitting area on the incident surface; a fourth point in a direction tilted from the optical axis as viewed from the light emitting region; a curvature of the first deflection surface at the fourth point is greater than a curvature of the first deflection surface at the third point.

4. The light guide member according to claim 1 , wherein the first deflection surface is a curved surface, and the deflection angle changes continuously from one end to the other end of the first deflection surface.

5. The light guide member according to claim 4 , wherein a rate of change of the deflection angle varies from one end to the other end of the first deflection surface.

6. 2. The light-guiding member according to claim 1, wherein, at each point on the second deflection surface, a visual angle of the light-emitting region when viewing the first deflection surface from the point is θ, and an optical path length of the optical path from the incident surface to the point is L, the longer the optical path, the larger θ×L becomes.

7. the first deflection surface reflects the light incident on the incident surface, The light guide member according to claim 1 , wherein the deflection angle is a reflection angle when light incident on the entrance surface is reflected by the first deflection surface.

8. The light guide member according to claim 7 , wherein the first deflection surface totally reflects at least a part of the light incident on the entrance surface.

9. The light guide member according to claim 1 , wherein 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 , wherein the second deflection surface totally reflects at least a part of the light deflected by the first deflection surface as parallel light.

11. The light guiding member according to claim 1 , and the light source.

12. A lighting device according to claim 11; a light guide plate into which the collimated light emitted from the second deflection surface is introduced and which forms a three-dimensional image in space as a real image or a virtual image.

13. A lighting device according to claim 11; a light guide plate formed integrally with the light guide member, into which the parallel light emitted from the second deflection surface is introduced to form a three-dimensional image in space as a real image or a virtual image.

Images