Light guide body, light source device, illuminating device, moving body, and prism sheet

Abstract

To restrain light from a light source from leaking to the side of a first surface of a light guide body.SOLUTION: A light guide body 1 comprises: a light guide part comprising an incidence surface 10 on which light emitted from a light source 2 is incident, a second surface 12 for reflecting the light incident from the incidence surface 10, and a first surface 11 provided so as to be opposed to the second surface 12, and for emitting the light incident from the second surface 12; and a prism 32 formed on the first surface 11, and formed in such a manner its cross section becomes larger as separating from the first surface 11. A reflection surface 32a of the prism 32 is inclined with respect to the first surface 11.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a light guide, a light source device, a lighting device, a moving body, and a prism sheet. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known a lighting device that includes a light guide plate provided on a sunroof of a vehicle and illuminates the interior of the vehicle using the light guide plate.

[0003] The lighting device of Patent Document 1 includes a light guide member having a configuration in which a light emitting surface that emits light and an incident surface that receives light intersect with each other. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-174132 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, a light-emitting surface (second surface) is formed on the front surface of a light-guiding member, and a diffuse reflection surface (first surface) is formed on the rear surface of the light-guiding member. A large number of recesses (prisms) are formed on the diffuse reflection surface. Light incident on the light-guiding member is diffusely reflected by these recesses and emitted into the interior of the vehicle.

[0006] However, in the configuration of Patent Document 1, the diffuse reflection surface is not smooth (flat) because a recess is formed on the diffuse reflection surface, which means that light incident on the diffuse reflection surface is not reflected toward the light emitting surface (second surface) and may leak toward the diffuse reflection surface (first surface).

[0007] Therefore, an object of the present disclosure is to provide a light guide, a light source device, a lighting device, a moving body, and a prism sheet that can prevent light from a light source from leaking to the first surface side. [Means for solving the problem]

[0008] In order to achieve the above object, a light guide according to one embodiment of the present disclosure comprises a light guide section having an incident surface into which light emitted from a light source is incident, a first surface that reflects the light incident from the incident surface, and a second surface that is arranged opposite the first surface and that outputs the light incident from the first surface; and a prism that is formed on the second surface and has a cross section that increases with increasing distance from the second surface, and the reflecting surface of the prism is inclined with respect to the second surface. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to prevent light from the light source from leaking to the first surface side. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a side view of an illumination device according to a first embodiment. [Figure 2] FIG. 2 is a perspective view of a prism sheet according to the first embodiment. [Figure 3] An enlarged view of region P in Figure 1. [Figure 4] FIG. 4 is a perspective view showing another example of the prism sheet according to the first embodiment. [Figure 5] FIG. 3 is a side view of the lighting device for explaining a method for bonding a prism sheet according to the first embodiment. [Figure 6] FIG. 10 is a side view of a lighting device according to a modified example of the first embodiment. [Figure 7] FIG. 10 is a side view of a lighting device according to a modified example of the first embodiment. [Figure 8] FIG. 10 is a side view of the lighting device according to the second embodiment. [Figure 9] FIG. 10 is a side view of the lighting device according to the third embodiment. [Figure 10] FIG. 10 is a side view of a lighting device according to a fourth embodiment. [Figure 11] FIG. 11 is a side view of an illumination device according to a fifth embodiment. [Figure 12]FIG. 13 is a side view of the lighting device according to the sixth embodiment. [Figure 13] FIG. 13 is a side view of an illumination device according to a seventh embodiment. [Figure 14] FIG. 13 is a side view of an illumination device according to an eighth embodiment. [Figure 15] FIG. 13 is a side view of an illumination device according to a ninth embodiment. [Figure 16] 1 is a schematic diagram of a moving body equipped with a lighting device. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiment is essentially merely illustrative and is not intended to limit the present invention, its applications, or its uses. In the following description, the same parts will be designated by the same reference numerals, and detailed description will be omitted as appropriate.

[0012] (First embodiment) FIG. 1 is a side view of the lighting device according to the first embodiment, and FIG. 2 is a perspective view of the prism sheet according to the first embodiment. As shown in FIGS. 1 and 2, the lighting device 100 includes a light guide plate 1 (light guide), multiple light sources 2, and a prism sheet 3. In the following description, the optical axis direction of the light source 2 is defined as the X direction, the thickness direction of the light guide plate 1 as the Z direction, and the direction perpendicular to the X and Z directions as the Y direction. In FIG. 1 and other figures, the light emitted from the light source 2 is indicated by a solid arrow. The light guide 1 and multiple light sources 2 correspond to a light source device.

[0013] The light guide plate 1 is a generally plate-shaped member made of a light-transmitting material such as glass. Examples of glass materials that make up the light guide plate 1 include BK7, synthetic quartz for excimer lasers, synthetic quartz, and anhydrous synthetic quartz. The light guide plate 1 may also be made of a light-transmitting material such as a resin. Examples of resin materials that make up the light guide plate 1 include polypropylene, polyethylene, polyethylene terephthalate, polyvinyl chloride, ABS resin, acrylic, polyamide, polycarbonate, and Teflon (registered trademark).

[0014] The light guide plate 1 has a first surface 11 (a reflecting surface) and a second surface 12 (a light emitting surface). The first surface 11 and the second surface 12 are flat surfaces that face each other.

[0015] The light source 2 is, for example, a solid-state light-emitting element such as a light-emitting diode (LED) element or an organic electro-luminescence (OEL) element. In this embodiment, the light source 2 is, for example, a chip-shaped light-emitting diode element. The light source 2 is arranged on the incident surface 10 of the light guide plate 1 (the surfaces on both the left and right sides of FIG. 1 ) and irradiates light onto the light guide plate 1. Although not shown, the multiple light sources 2 are aligned in the Y direction. In the light guide plate 1, the area including the first surface 11, the second surface 12, and the incident surface 10 corresponds to the light guide section.

[0016] The prism sheet 3 is a sheet-like member made of a light-transmitting material. The prism sheet 3 is provided on the second surface 12 side of the light guide plate 1 via an adhesive layer 4 formed on the entire surface of the second surface 12 of the light guide plate 1.

[0017] As shown in FIG. 1, the prism sheet 3 includes a sheet main body 31 and a plurality of prisms 32. Examples of materials for the sheet main body 31 include polyethylene terephthalate (PET). Examples of materials for the prisms 32 include UV resin. The plurality of prisms 32 are convex members formed on the upper side of the sheet main body 31 in the drawing. Here, the prisms 32 are formed in a substantially truncated cone shape (see FIG. 2). As shown in FIG. 1, the tips of the prisms 32 are attached to the second surface 12 of the light guide plate 1 via an adhesive layer 4 (first adhesive layer) that is adhered to the second surface 12 of the light guide plate 1.

[0018] Light emitted from light source 2 enters light guide plate 1 through incident surface 10, and is then reflected by first surface 11 and second surface 12, thereby being diffused within light guide plate 1. When the light enters prism 32 attached to second surface 12, it is emitted downward in the drawing by reflecting surface 32a of prism 32.

[0019] 1, prism 32 that emits light to second surface 12 is formed on the second surface 12 side, not on the first surface 11 side, so first surface 11 can be made flat and smooth. This allows light incident from light source 2 to be totally reflected by first surface 11, making it possible to prevent light from leaking to the first surface 11 side (outside, upper side in the drawing).

[0020] FIG. 3 is an enlarged view of region P in FIG. 1. In FIG. 3, the angle θ between the reflecting surface 32a of the prism 32 and the second surface 12 is set to be 35° to 85°. When the angle θ is less than 35°, the light incident on the prism 32 is less likely to hit the reflecting surface 32a, and the light is less likely to be emitted downward in the drawing. On the other hand, when the angle θ is greater than 85°, the light incident on the prism 32 passes through the reflecting surface 32a, and the light is less likely to be emitted downward in the drawing. Therefore, by setting the angle θ to be 35° to 85°, the light from the light source 2 can be irradiated inward (toward the bottom of the drawing). Furthermore, by adjusting the angle θ, the light can be irradiated along the Z direction. This prevents direct light from reaching the eyes of people inside (toward the bottom of the drawing), making the lighting device less dazzling to those who look at it.

[0021] The material of the light guide plate 1 may have a higher refractive index than the material of the prism sheet 3 and the material of the adhesive layer 4. This makes it easier for light to be emitted inward (toward the bottom in the drawing), improving the light extraction efficiency.

[0022] (Regarding the shape of the prism) In FIG. 2, the shape of the prism 32 is a substantially truncated cone, but the shape of the prism 32 is not limited to this.

[0023] 4(a) to 4(e) are perspective views showing other examples of the prism sheet according to the first embodiment. As shown in FIGS. 4(a) to 4(c), the prisms 32 may be conical, semicircular, or pyramidal, such as a square pyramid. Furthermore, as shown in FIGS. 4(d) and 4(e), the prisms 32 may extend in the Y direction (or X direction) and have a triangular or semicircular cross section. Note that when the prisms 32 have the configurations shown in FIGS. 1 and 4(a) to 4(c), i.e., truncated cone, cone, semicircular, or square pyramidal, the prisms 32 may be randomly arranged. Furthermore, when the prisms 32 have the configuration shown in FIG. 4(e), i.e., when the prisms 32 have a circular cross section, the angle θ between the reflecting surface 32a of the prism 32 and the second surface 12 may be 35° to 90°.

[0024] (Prism sheet adhesive method) In FIG. 1, the prism sheet 3 is adhered to the second surface 12 of the light guide plate 1 by attaching the tips of the prisms 32 to an adhesive layer 4 formed on the entire surface of the second surface 12 of the light guide plate 1, but the method of adhering the prism sheet 3 to the second surface 12 of the light guide plate 1 is not limited to this.

[0025] 5(a) and 5(b) are side views of the lighting device for explaining the method of bonding the prism sheet according to the first embodiment.

[0026] As shown in Fig. 5(a), the prism sheet 3 may be bonded to the second surface 12 of the light guide plate 1 by inserting the tips of the prisms 32 into the adhesive layer 4 formed on the entire surface of the second surface 12 of the light guide plate 1. In this case, the shape of the prisms 32 will be such that the tips form acute angles, as shown in Fig. 4(a) or the like.

[0027] As shown in FIG. 5( b ), the prism sheet 3 may be bonded to the second surface 12 of the light guide plate 1 by forming an adhesive layer 4 on each tip of the prisms 32 .

[0028] As shown in FIG. 5(c), the tips of the prisms 32 may be melted to bond the prism sheet 3 to the second surface 12 of the light guide plate 1.

[0029] As shown in FIG. 5(d), when the prisms 32 are made of UV resin, the prism sheet 3 may be adhered to the second surface 12 of the light guide plate 1 when the prisms 32 are irradiated with UV light during production.

[0030] (Variation 1) Fig. 6 is a side view of an illumination device according to a modified example of the first embodiment. In Fig. 6, the prisms 32 are not formed on the sheet body 31 of the prism sheet 3, but are formed directly on the second surface 12 of the light guide plate 1.

[0031] Even with the configuration of FIG. 6, the same effect as that of FIG. 1 can be obtained.

[0032] (Variation 2) 7 is a side view of an illumination device according to a modified example of the first embodiment. In FIG. 7, the prism sheet 3 includes a sheet portion 33 and an adhesive layer 34 (second adhesive layer). The sheet portion 33 and the adhesive layer 34 are formed between the adhesive layer 4 and the sheet main body portion 31 (prisms 32) of the prism sheet 3. The sheet portion 33 is a sheet-like member made of a material having the same translucency as the sheet main body portion 31. The adhesive layer 34 is made of the same material as the adhesive layer 4.

[0033] 7, the tip of the prism 32 is attached (bonded) to the sheet portion 33 via an adhesive layer 34. The sheet portion 33 is attached (bonded) to the second surface 12 of the light guide plate 1 via an adhesive layer 4.

[0034] In the configuration of FIG. 7, the prism sheet 3 includes a sheet portion 33 attached to the tips of the prisms 32. By attaching the sheet portion 33 to the second surface 12 of the light guide plate 1, the prism sheet 3 can be adhered to the light guide plate 1. This makes it easier to adhere the prism sheet 3 to the light guide plate 1 than when the tips of the prisms 32 are attached to the adhesive layer 4 as in FIG. 1.

[0035] (Second embodiment) 8 is a side view of the lighting device according to the second embodiment. In FIG. 8, a reinforcing member 5 is formed between the second surface 12 of the light guide plate 1 and the sheet body 31 of the prism sheet 3.

[0036] The reinforcing member 5 is provided between the second surface 12 of the light guide plate 1 and the sheet main body 31 of the prism sheet 3, and is a member for preventing the prism sheet 3 from peeling off from the light guide plate 1. Examples of materials for the reinforcing member 5 include rubber, resin, glass, UV resin, and wax.

[0037] Although not shown in the figures, the reinforcing member 5 is formed to surround the outer peripheral edge of the second surface 12 of the light guide plate 1. An opening 51 is formed in a part of the reinforcing member 5. The opening 51 is a small hole that prevents insects and the like from entering between the second surface 12 of the light guide plate 1 and the sheet main body 31 of the prism sheet 3 from the outside.

[0038] In the configuration of FIG. 8, by providing the reinforcing member 5 between the adhesive layer 4 and the sheet body 31 of the prism sheet 3, it is possible to prevent the prism sheet 3 from peeling off from the light guide plate 1.

[0039] Furthermore, by providing an opening 51 in a part of the reinforcing member 5, even if the air between the second surface 12 of the light guide plate 1 and the sheet main body portion 31 of the prism sheet 3 thermally expands, the air is discharged to the outside, thereby preventing damage to the prism sheet 3.

[0040] The reinforcing member 5 does not have to be formed so as to surround the outer peripheral edge of the second surface 12 of the light guide plate 1, and may be provided at any position between the second surface 12 of the light guide plate 1 and the sheet main body portion 31 of the prism sheet 3 as long as it can prevent the prism sheet 3 from peeling off from the light guide plate 1.

[0041] (Third embodiment) Fig. 9(a) is a side view of an illumination device according to embodiment 3. In Fig. 9(a), the thickness of the light guide plate 1 near its center is thinner than the thickness of the light guide plate 1 at its edges.

[0042] 9(a), the thickness of the light guide plate 1 near the center is thin, which can prevent light incident on the light incident surface 10 of the light guide plate 1 from escaping to the opposite surface. Specifically, light incident on the light incident surface 10 on the left side of the drawing is less likely to escape from the surface on the right side of the drawing. This can improve the light extraction efficiency of the lighting device.

[0043] 9(a), the second surface 12 of the light guide plate 1 is flat and the first surface 11 is concave, but as shown in FIG. 9(b), the first surface 11 of the light guide plate 1 may be flat and the second surface 12 may be concave. In the case of FIG. 9(b), the sheet main body 31 of the prism sheet 3 may be formed along the second surface 12.

[0044] (Fourth embodiment) 10(a) is a side view of an illumination device according to Embodiment 4. In FIG. 10(a), the number of prisms 32 formed on the prism sheet 3 is greater than in FIG.

[0045] In the configuration of FIG. 10(a), by increasing the number of prisms 32 formed on the prism sheet 3, the light extraction efficiency of the lighting device can be improved.

[0046] The number of prisms 32 is set so that the area of ​​the reflective surfaces 32a of all prisms 32 formed on the prism sheet 3 is 50% or less of the area of ​​the second surface 12 (or first surface 11) of the light guide plate 1. When viewed from below in the drawing, the area of ​​the reflective surfaces 32a of the prisms 32 obscures the view outside (upper side of the drawing). In other words, by reducing the area of ​​the reflective surfaces 32a of all prisms 32 formed on the prism sheet 3, it is possible to prevent the view outside (upper side of the drawing) from being obscured.

[0047] Fig. 10(b) is a side view of another example of the lighting device according to the fourth embodiment. In Fig. 10(b), the size of the prisms 32 formed on the prism sheet 3 is larger than that in Fig. 1. Even with this configuration, the light extraction efficiency of the lighting device can be improved.

[0048] (Fifth embodiment) Fig. 11 is a side view of an illumination device according to a fifth embodiment. In Fig. 11, the second surface 12 and the first surface 11 of the light guide plate 1 are curved. In addition, the angle θ (θ1, θ2, etc.) formed between the reflecting surface of the prisms 32 of the prism sheet 3 and the second surface 12 of the light guide plate 1 differs for each prism 32.

[0049] 11, the second surface 12 and the first surface 11 of the light guide plate 1 are curved, which makes it possible to apply the light guide plate 1 to a lighting device having a curved surface. Note that the second surface 12 and the first surface 11 may be free-form surfaces.

[0050] Furthermore, by setting the angle θ for each prism 32, it is possible to irradiate light in a desired direction.

[0051] (Sixth embodiment) Fig. 12(a) is a side view of an illumination device according to embodiment 6. In Fig. 12(a), a low refractive index layer 6 is formed between the second surface 12 of the light guide plate 1 and the sheet body 31 of the prism sheet 3.

[0052] The low refractive index layer 6 is provided between the second surface 12 of the light guide plate 1 and the sheet body 31 of the prism sheet 3, and is made of a material with a low refractive index.

[0053] 12(a), by forming a low refractive index layer 6 between the second surface 12 of the light guide plate 1 and the sheet body portion 31 of the prism sheet 3, it is possible to prevent the prism sheet 3 from peeling off from the light guide plate 1. Furthermore, by forming the low refractive index layer 6 from a material with a low refractive index, it is possible to prevent a decrease in the efficiency of total reflection of light at the second surface 12 of the light guide plate 1.

[0054] Fig. 12(b) is a side view of another example of the lighting device according to the sixth embodiment. In Fig. 12(b), the second surface 12 of the light guide plate 1 and the sheet body portion 31 of the prism sheet 3 are bonded via an adhesive layer 4. Even with this configuration, the same effect as in Fig. 12(a) can be obtained.

[0055] (Seventh embodiment) 13 is a side view of an illumination device according to Embodiment 7. In FIG. 13, a collimator lens 7 is provided between the light source 2 and the incident surface 10 of the light guide plate 1.

[0056] As shown in Figure 13, the collimating lens 7 is positioned between the light source 2 and the incident surface 10 of the light guide plate 1, and is a lens that collects light incident from the light source 2 and makes it incident on the incident surface 10 of the light guide plate 1.

[0057] In the configuration of Figure 13, by providing the lighting device with a collimating lens 7, the light incident from the light source 2 can be concentrated onto the incident surface 10 of the light guide plate 1, thereby improving the light utilization efficiency of the lighting device.

[0058] (Eighth embodiment) Fig. 14 is a side view of an illumination device according to embodiment 8. In Fig. 14, a prism sheet 3 has a plurality of protrusions 8 formed thereon, which are microstructures.

[0059] 14, the plurality of protrusions 8 are formed between the second surface 12 of the light guide plate 1 and the sheet main body 31 of the prism sheet 3. The tip of each protrusion 8 is adhered to the adhesive layer 4. The total area of ​​the plurality of protrusions 8 when viewed from below in the drawing is 1 / 10 or less of the area of ​​the second surface 12 of the light guide plate 1.

[0060] In the configuration of FIG. 14, by forming a fine structure in the prism sheet 3 in which the tip of each projection 8 is bonded to the adhesive layer 4, the strength of the prism sheet 3 can be improved.

[0061] (Ninth embodiment) Fig. 15(a) is a side view of an illumination device according to a ninth embodiment. In Fig. 15(a), the pitch between the prisms 32 in the prism sheet 3 is narrow at the center and wide at the outer peripheral edge. That is, in Fig. 15(a), the pitch between the prisms 32 is narrow (the pitch between the prisms 32 is dense) at a position far from the light source 2 (the center), and the pitch between the prisms 32 is wide (the pitch between the prisms 32 is sparse) at a position close to the light source 2 (the outer peripheral edge).

[0062] In an illumination device, positions closer to the light source 1 tend to be brighter and positions farther from the light source 1 tend to be darker. Therefore, in the configuration of Fig. 15(a), the pitch between prisms 32 at positions farther from the light source 2 is narrowed and the pitch between prisms 32 at positions closer to the light source 2 is widened, thereby making it possible to make the illuminance of the illumination device uniform.

[0063] Fig. 15(b) is a side view of another example of the lighting device according to the ninth embodiment. In Fig. 15(b), the size of the prisms 32 in the prism sheet 3 is large in the central portion and small in the peripheral edge portion. That is, in Fig. 15(b), the size of the prisms 32 is large in the position far from the light source 2 (central portion) and small in the position close to the light source 2 (periphery edge portion). Even with the configuration in Fig. 15(b), the same effect as in Fig. 15(a) can be obtained.

[0064] (Other embodiments) As described above, the embodiments have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate.

[0065] In each of the above embodiments, the sheet body 31 of the prism sheet 3 may be made of a smoked material, thereby reducing the glare of the lighting device.

[0066] FIG. 16 is a schematic diagram of a moving body equipped with an illumination device. As shown in FIG. 16, the illumination device 100 is disposed in a moving body 200 (here, a vehicle). Specifically, the light guide plate 1 in the illumination device 100 is provided as a sunroof of the moving body 200. By providing the illumination device 100 in the moving body 200, it is possible to illuminate the sunroof of the moving body 200 while suppressing leakage of light from the light source 2 of the illumination device 100 to the outside of the moving body 200, and it is also possible to view the scenery outside the moving body 200 from inside the moving body 200. Note that the moving body 200 is not limited to a vehicle, and may be, for example, a large vehicle such as a truck or a bus, a motorcycle, a train, an electric cart, construction machinery, an aircraft, a ship, or the like. Furthermore, the illumination device 100 may be any of the illumination devices in the above-described embodiments and modified examples.

[0067] Furthermore, in the above-described embodiments and modifications, the light guide plate 1 is described as an example of a light guide, but the light guide is not limited to the light guide plate 1. The light guide may be any optical element having optical properties corresponding to the above-described embodiments and modifications. [Industrial Applicability]

[0068] The light guide plate of the present disclosure can be applied to, for example, the sunroof of a vehicle. [Explanation of symbols]

[0069] 1 Light guide plate (light guide section, light guide, light source device) 2 Light source (light source device) 3 Prism sheet 31 Seat body 32 Prism 32a Reflective surface 33 Seat section 34 Adhesive layer (second adhesive layer) 4 Adhesive layer (first adhesive layer) 5 Reinforcing members 51 Aperture 6 Low refractive index layer 7 Collimating Lens 8. Concave (microstructure) 10 Incident plane 11 Page 1 12 Page 2 100 lighting fixtures 200 moving objects

Claims

1. a light guide unit having an incident surface on which light emitted from a light source is incident, a first surface that reflects the light incident from the incident surface, and a second surface that is provided opposite to the first surface and that emits the light incident from the first surface; a prism formed on the second surface, the cross section of which increases with increasing distance from the second surface; The reflective surface of the prism is inclined with respect to the second surface.

2. 2. The light guide according to claim 1, wherein the reflective surface of the prism forms an angle of 35° to 85° with the second surface.

3. The light guide according to claim 1 , wherein the material of the prisms has a higher refractive index than the material of the light guide portion.

4. The light guide according to claim 1 , wherein the light guide portion has a thickness smaller at a center portion than at an end portion.

5. The light guide according to claim 1 , wherein at least one of the first surface and the second surface is a free-form surface.

6. a plurality of the prisms; The light guide according to claim 1 , wherein the plurality of prisms include prisms whose reflecting surfaces form angles with the second surface that are different from one another.

7. a plurality of the prisms; The light guide according to claim 1 , wherein the pitch between the prisms arranged in the central portion of the second surface is narrower than the pitch between the prisms arranged in the end portion of the second surface.

8. a plurality of the prisms; The light guide according to claim 1 , wherein the size of the prisms arranged at the center of the second surface is larger than the size of the prisms arranged at the ends of the second surface.

9. The light guide according to claim 1 , further comprising a prism sheet having a sheet body and a plurality of the prisms.

10. The light guide according to claim 9 , further comprising a reinforcing member disposed between the second surface and the sheet main body, the reinforcing member connecting the second surface and the sheet main body.

11. The light guide according to claim 10 , wherein the reinforcing member is formed so as to surround a certain area of ​​the second surface, and an opening is provided in a part of the reinforcing member.

12. The light guide according to claim 9 , further comprising a low refractive index layer disposed between the second surface and the sheet main body, the low refractive index layer connecting the second surface and the sheet main body.

13. The light guide according to claim 9 , wherein a first adhesive layer having a low refractive index is disposed between the second surface and the sheet main body portion, and the first adhesive layer adheres the second surface and the sheet main body portion to each other.

14. the prism is bonded to the second surface via a first adhesive layer; The light guide according to claim 9 , wherein the sheet body portion has a microstructure whose tip portion is adhered to the first adhesive layer.

15. The light guide according to claim 9 , wherein the sheet body is made of a smoked material.

16. The light guide according to claim 1 ; a light source device comprising the light source.

17. The light source device according to claim 16 , further comprising a collimating lens disposed between the light source and the incident surface, the collimating lens focusing the light from the light source.

18. An illumination device comprising the light source device according to claim 16.

19. The light guide according to claim 1 ; and the light source.

20. A prism sheet bonded to a light guide section having an incident surface on which light emitted from a light source is incident, a first surface that reflects the light incident from the incident surface, and a second surface that is provided opposite to the first surface and that emits the light incident from the first surface, A seat main body portion; a prism formed on the sheet main body portion, the cross section of which becomes smaller as the distance from the sheet main body increases; a tip end of the prism is bonded to the second surface via a first adhesive layer bonded to the second surface; A prism sheet, wherein the reflecting surfaces of the prisms are inclined with respect to the second surface.

21. The prism sheet is configured such that the prism is bonded to the first adhesive layer via a sheet portion formed in a sheet shape and a second adhesive layer.

Images