Optical devices

Abstract

In optical devices, the safety of the viewer is ensured by vanes using predetermined standards, and the vanes are positioned so as not to obstruct the viewer's view. [Solution] The corner extension outer surface 312 has a radius of curvature greater than or equal to a predetermined standard value Br at the corner 311, and extends from the other side to the one side in the first direction D1 while curving to the other side in the second direction D2. The louvers 4 are arranged such that the virtual spherical shape 73, defined in the predetermined standard that determines the above standard value Br, is away from all of the injection prism parts 22 of the injection part 2c in a predetermined arrangement state. This predetermined arrangement state is the state in which the virtual spherical shape 73 does not intersect with any of the multiple vanes 41, but is in contact with the terminal vane 42 and the corner extension outer surface 312, and is closest to the injection prism part 22.

Description

Technical Field

[0001] The present disclosure relates to an optical device including a light guide.

Background Art

[0002] As this type of optical device, for example, a blind spot assist device described in Patent Document 1 has been conventionally known. The blind spot assist device described in Patent Document 1 is disposed, for example, in the A-pillar portion of a vehicle, and can display an area that becomes a blind spot due to the A-pillar portion to a driver as a viewer.

[0003] Specifically, the blind spot assist device of Patent Document 1 includes an optical member that is a light guide made of a translucent material. And the optical member has an incident surface on which outside scene light is incident, an emission surface having a plurality of prism portions and flat portions, and a smooth surface disposed opposite to the plurality of flat portions. With such a configuration, the optical member guides the outside scene light incident from the incident surface to the emission surface while reflecting it inside, and emits it from the emission surface toward the viewer.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the blind spot assist device described in Patent Document 1, the multiple prism sections provided on the light guide's emission surface (in other words, the emission section) each have a prism shape, and therefore the tips of these prism sections are, for example, pointed. Furthermore, the blind spot assist device described in Patent Document 1 does not have a configuration that prevents the occupant from coming into contact with the tips of the prism sections. For this reason, the blind spot assist device described in Patent Document 1 cannot be said to adequately ensure the safety of the occupant. In addition, if, for example, standards for ensuring the safety of the occupant are established, the blind spot assist device described in Patent Document 1 may not be able to meet the requirements of those standards.

[0006] Therefore, the inventors considered providing a louver with multiple vanes on the light guide's emission section to prevent external light from entering the emission section, and to prevent the occupant from coming into contact with the tip of the prism section by narrowing the spacing between the vanes. However, if the inventors were to simply use the louver to prevent the occupant from coming into contact with the tip of the prism section, it would be necessary to position the vanes even closer to the occupant than the prism section that is closest to the occupant among the multiple prism sections. In that case, the vane positioned closest to the occupant among the multiple vanes would protrude toward the viewer, which would be an obstruction in optical devices such as the blind spot assist device described in Patent Document 1. The inventors found the above to be the result of their detailed investigation.

[0007] In view of the above points, this disclosure aims to provide an optical device that ensures the safety of the viewer by using louvers according to a predetermined standard, and that allows the louver blades to be positioned so as not to obstruct the viewer. [Means for solving the problem]

[0008] To achieve the above objective, an optical apparatus according to one aspect of this disclosure is: A light guide (2) made of a translucent material has an incident portion (2a) into which ambient light (L1) is incident, an ejection portion (2c) that forms an outer surface on one side in a first direction (D1), and an end portion (2e) that forms an outer surface on one side in a second direction (D2) perpendicular to the first direction, opposite to the incident portion side, and A holding member (3) that partially covers the light guide and holds the light guide, The device comprises a louver (4) positioned on one side of the injection section in a first direction, held by a holding member, and having one or more vanes (41, 42, 43, 44) that suppress the incidence of ambient light (La) into the injection section, The emission section has multiple prism sections (22, 221, 222) that are arranged in a protruding shape in a second direction and emit a portion of the incident light (L2) that enters the interior of the light guide from the incident section to the outside of the light guide. The light guide and the holding member constitute a light guide unit (10). The light guide unit has a corner portion (24, 311) located on one side in the first direction and one side in the second direction, and a corner extension outer surface (25, 312) that extends from the corner portion to the other side in the second direction and is formed as an outer surface facing one side in the first direction on the other side in the second direction. The corner extension outer surface includes a curved portion that extends from the other side in the first direction to the other side while curving toward the other side in the second direction with a radius of curvature of a predetermined standard value (Br) or greater at the corner, and is formed as part of the end portion or as part of the end cover portion (31) of the retaining member that covers the end portion. The louvers are arranged such that, when the virtual spherical shape (73) defined in the specified standard is in contact with the louvers and the outer surface of the corner extension without intersecting any of the one or more slats, and is closest to the multiple prism sections, the virtual spherical shape moves away from the multiple prism sections. The standard values ​​are also defined in the prescribed standards.

[0009] In this way, for example, the corners of the light guide unit become rounded, and the virtual spherical shape cannot be contacted by the viewer from the tip of the prism. In other words, by using the virtual spherical shape and standard values ​​defined in the above-mentioned standard, it is possible to ensure the safety of the viewer with the louvers.

[0010] Furthermore, by utilizing not only the vanes but also the extended outer surface at the corners, it is possible to prevent the virtual spherical shape from contacting the prism section of the ejection unit. Therefore, compared to simply preventing the virtual spherical shape from contacting the prism section with multiple vanes alone, the vanes can be positioned further away from the viewer, allowing them to be positioned in a way that is less obstructive to the viewer.

[0011] In addition, each element in the application documents may be given a reference numeral in parentheses. In this case, the reference numeral merely indicates one example of the correspondence between the element and the specific configuration described in the embodiments described later. Therefore, this disclosure is not limited in any way by the inclusion of such reference numerals. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic plan view showing the positional relationship between the optical device, the viewer, and the light-shielding body in the first embodiment. [Figure 2] This is a schematic cross-sectional view showing the optical device of the first embodiment. [Figure 3] This is a schematic perspective view showing the optical device of the first embodiment. [Figure 4] This is a schematic perspective view of the optical device of the first embodiment, shown in a different orientation than that of Figure 3. [Figure 5] Figure 2 is a cross-sectional view showing an excerpt of a part of the light guide and a part of the louver. [Figure 6] This is a schematic cross-sectional view of the end vane of the louver and its surrounding area, shown in the same orientation as in Figure 2, in the reference example referred to in the description of the first embodiment. [Figure 7] This is a schematic cross-sectional view of the optical apparatus of the first comparative example, shown in the same orientation as in Figure 2. [Figure 8] This is a schematic cross-sectional view of the optical apparatus of the second comparative example, shown in the same orientation as in Figure 2, and corresponds to Figure 7. [Figure 9]A cross-sectional view schematically showing the optical device of the third comparative example in the same orientation as FIG. 2, which is a figure corresponding to FIG. 7. [Figure 10] A cross-sectional view schematically showing the optical device of the fourth comparative example in the same orientation as FIG. 2, which is a figure corresponding to FIG. 7. [Figure 11] A cross-sectional view schematically showing the optical device of the fifth comparative example in the same orientation as FIG. 2, which is a figure corresponding to FIG. 7. [Figure 12] A view in the direction of the arrow XII in FIG. 2 in the second embodiment, which is a figure schematically showing an extract of the end-side blade of the louver. [Figure 13] A cross-sectional view schematically showing the optical device of the third embodiment, which is a figure corresponding to FIG. 2. [Figure 14] A perspective view schematically showing the optical device of the third embodiment, which is a figure corresponding to FIG. 3. [Figure 15] A cross-sectional view schematically showing the optical device of the fourth embodiment, which is a figure corresponding to FIG. 2. [Figure 16] A perspective view schematically showing the optical device of the fourth embodiment, which is a figure corresponding to FIG. 3. [Figure 17] A cross-sectional view schematically showing a cross-section corresponding to the XVII-XVII cross-section of FIG. 13 in the fifth embodiment, which is a figure showing one-side corner portion and the other-side corner portion connected to the end cover portion of the housing. [Figure 18] A perspective view schematically showing the optical device of the fifth embodiment, which is a figure corresponding to FIG. 3. [Figure 19] A cross-sectional view schematically showing the optical device of the sixth embodiment, which is a figure corresponding to FIG. 2. [Figure 20] A perspective view schematically showing the optical device of the sixth embodiment, which is a figure corresponding to FIG. 3.

Embodiments for Carrying out the Invention

[0013] The embodiments will be described below with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other are denoted by the same reference numerals in the drawings.

[0014] (First Embodiment) The optical device 1 of this embodiment, as shown in Figure 1 for example, is attached to a member or obstacle that obstructs the view of a user (viewer 70) and creates a blind spot, and is used as a blind spot assisting device to allow the viewer 70 to see the scenery in the blind spot area. For example, in this embodiment, the optical device 1 is one of the in-vehicle devices mounted on a vehicle and is attached to a predetermined light-shielding body 72, such as a pillar of the vehicle on which it is mounted. The optical device 1 then guides the ambient light from the area that becomes a blind spot due to the light-shielding body 72 towards the viewer 70, who is the driver, and allows the viewer 70 to see the scenery in the blind spot area.

[0015] As shown in Figures 1 and 2, the optical device 1 comprises a light guide 2, a housing 3, and a louver 4. In this embodiment, the light guide 2 and the housing 3 are collectively referred to as the light guide unit 10. The arrow As in Figure 2 points in the direction of the viewer 70. Figures 1 and 2 are cross-sections obtained by cutting the optical device 1 in a horizontal or substantially horizontal plane in the vehicle. Figure 2 also shows the II-II cross-section in Figure 3.

[0016] The optical device 1 is attached to the light shield 72 on the side facing the viewer 70. The optical device 1 guides ambient light inside the light guide 2 and emits it towards the viewer 70, thereby allowing the viewer 70 to see the blind spot area, while the housing 3 and louvers 4 prevent unwanted light from entering the light guide 2.

[0017] As shown in Figure 2, the light guide 2 is formed in the shape of a plate with the first direction D1 as the thickness direction. The light guide 2 has an incident portion 2a, a reflective surface 2d adjacent to the incident portion 2a, an ejection portion 2c provided on the opposite side from the incident portion 2a and the reflective surface 2d, a side surface 2b connecting the incident portion 2a and the ejection portion 2c, and an end surface 2e connecting the ejection portion 2c and the reflective surface 2d.

[0018] The light guide 2 is, for example, a transparent single-component material made of a light-transmitting material. The light-transmitting material could be, for example, a resin material such as polyethylene terephthalate, polycarbonate, polyethylene, or acrylic, or an inorganic material such as glass. The light guide 2 has a mirrorless structure without a mirror made of a reflective material different from the light-transmitting material, and is designed to guide light by totally reflecting the incident light from the incident part 2a internally.

[0019] In this description of the embodiment, for convenience, the first direction D1, second direction D2, and third direction D3 may be used, as shown in Figures 2 and 3. These first direction D1, second direction D2, and third direction D3 are directions that intersect each other, or more precisely, directions that are perpendicular to each other. In Figure 2, one side of the first direction D1 is on the bottom of the paper, and the other side is on the top of the paper. One side of the second direction D2 is on the right side of the paper, and the other side is on the left side of the paper. The direction from the other side of the second direction D2 to the one side is the direction in which the incident light L2 is guided inside the light guide 2, and can also be called the light guidance direction.

[0020] The incident section 2a is the portion of the light guide 2 into which ambient light L1 is incident. The incident section 2a has a plurality of incident prism sections 21. These plurality of incident prism sections 21 are projections that form a triangular shape when viewed along the third direction D3, and are arranged to extend along the third direction D3 and be parallel to each other. As shown in Figure 2, the plurality of incident prism sections 21 have an incident surface 21a, which is the side surface on the other side of the triangular shape of the incident prism section 21 in the second direction D2, and an adjacent surface 21b, which is the side surface on the one side of the triangular shape in the second direction D2.

[0021] The incident surface 21a of the incident prism section 21 allows a portion of the ambient light L1, which is directed from the other side of the first direction D1 relative to the incident prism section 21 toward the incident surface 21a, to enter the interior of the light guide 2. The multiple incident prism sections 21 are arranged such that, for example, the heights of the portions that protrude from the reflective surface 2d toward the other side of the first direction D1 are approximately the same, and their respective incident surfaces 21a are approximately parallel. "Approximately the same" includes not only cases where they are completely identical, but also cases where they are not completely identical due to unavoidable errors such as manufacturing errors, but are nearly identical. Furthermore, the inclination angle of the adjacent surfaces 21b of the multiple incident prism sections 21 is set to be below a predetermined angle so as not to obstruct the incidence of ambient light L1 onto the incident surface 21a of other incident prism sections 21 adjacent to that adjacent surface 21b.

[0022] For the purposes of this embodiment, as shown in Figure 2, the light from the incident section 2a that enters the interior of the light guide 2 from the ambient light L1 is sometimes referred to as incident light L2. Furthermore, the light from the incident light L2 that is emitted from the emission prism section 22 (described later) to the outside of the light guide 2 is sometimes referred to as emitted light L3.

[0023] Side surface 2b is designed such that, for example, the incident light L2 does not escape from side surface 2b, and the inclination of the surface is greater than or equal to the incident angle φ of the incident light L2 to side surface 2b. The incident angle φ of the incident light L2 is the angle between the direction normal to the plane formed by side surface 2b, the flat surface 23, or the reflective surface 2d (hereinafter simply referred to as the "normal direction") and the direction of propagation of the incident light L2. The light guide 2 is designed to enable light guidance in a mirrorless structure by satisfying the total internal reflection condition of the following equation F1, with the refractive index of the constituent material of the light guide 2 being n and the external medium being air with a refractive index of 1. sinφ≧1 / n ···(F1)

[0024] The emission section 2c forms an outer surface provided on one side of the light guide 2 in the first direction D1, and emits a portion of the incident light L2 to the outside of the light guide 2. Specifically, the emission section 2c has a plurality of emission prism sections 22 and a plurality of flat surfaces 23. The emission prism sections 22 correspond to the prism sections of this disclosure.

[0025] Furthermore, the ejection section 2c is the surface to which the incident light L2 from the incident section 2a first reaches, and the ejection prism section 22 and the flat surface 23 are arranged alternately in the second direction D2. As shown in Figures 2 to 4, each of the multiple ejection prism sections 22 is formed as a projection that forms a triangular shape when viewed along the third direction D3, and is arranged to extend along the third direction D3 and be parallel to each other. Also, each of the multiple flat surfaces 23 is a plane that is substantially parallel to the reflective surface 2d and extends along the third direction D3.

[0026] As shown in Figure 2, each of the multiple emission prism sections 22 has an emission surface 22a, which is one side of the triangular shape of the emission prism section 22 in the second direction D2, and another surface 22b, which is the other side of the triangular shape in the second direction D2. The emission surface 22a is, for example, parallel to the incident surface 21a, and emits a portion of the incident light L2 to the outside of the light guide 2.

[0027] Furthermore, each of the multiple ejection prism sections 22 has its triangular apex as its tip 22c. For example, since the multiple ejection prism sections 22 form the same triangular shape when viewed along the third direction D3, the positions of their tips 22c are aligned in the first direction D1.

[0028] The multiple flat surfaces 23 are, for example, flat surfaces located on the same plane as each other, and reflect a portion of the incident light L2 into the interior of the light guide 2. That is, each of the multiple flat surfaces 23 is a first reflective surface that reflects the incident light L2 that reaches that flat surface 23 toward the reflective surface 2d by total internal reflection.

[0029] In this embodiment, the ejection prism section 22 located on the furthest side of the second direction D2 among the multiple ejection prism sections 22 of the ejection section 2c may be referred to as the first ejection prism section 221. Furthermore, the ejection prism section 22 adjacent to the first ejection prism section 221 on the other side of the second direction D2 may be referred to as the second ejection prism section 222. The first ejection prism section 221 corresponds to the first prism section of this disclosure, and the second ejection prism section 222 corresponds to the second prism section of this disclosure.

[0030] The reflective surface 2d is formed as the outer surface of the light guide 2 facing the other side of the first direction D1, and reflects the incident light L2 reflected by the multiple flat surfaces 23 toward the emission section 2c. In other words, the reflective surface 2d is a second reflective surface that reflects the incident light L2 reflected by the flat surfaces 23 toward the emission section 2c by total internal reflection. The reflective surface 2d is the surface corresponding to the back surface if the emission section 2c facing the viewer 70 is considered the front surface. The entire reflective surface 2d is covered by the housing 3 with a gap in between so that ambient light L1 does not enter it.

[0031] In this embodiment, the terminal surface 2e is provided as the terminal portion that forms the outer surface of the light guide body 2 on one side of the second direction D2, which is opposite to the incident portion 2a in the second direction D2. Therefore, the terminal surface 2e is connected to the exit portion 2c at one end of the exit portion 2c in the second direction D2, and to the reflecting surface 2d at one end of the reflecting surface 2d in the second direction D2. As a result, the terminal surface 2e is the surface to which a portion of the incident light L2 lasts. In this embodiment, the terminal surface 2e forms a single plane together with the exit surface 22a of the first exit prism portion 221, but it may be any other shape, such as a different surface shape.

[0032] Furthermore, although not shown in the figure, the light guide 2 has one end face provided on one side in the third direction D3 and another end face provided on the other side in the third direction D3. These one end face and the other end face, like the side surface 2b, are non-optical surfaces that are not used for guiding the incident light L2 inside the light guide 2, i.e., for reflection.

[0033] As shown in Figures 2 and 3, the housing 3 functions as a holding member for the light guide 2. For example, since the light guide 2 is fixed to the housing 3, the light guide 2 is immobile relative to the housing 3.

[0034] Furthermore, the light guide 2 is housed within the housing 3, and the housing 3 partially covers the light guide 2. For example, in this embodiment, the housing 3 covers the side surface 2b, reflective surface 2d, end surface 2e, one end surface, and the other end surface of the light guide 2 with gaps between them. In short, the housing 3 covers the portion of the light guide 2 other than the incident portion 2a and the output portion 2c. The housing 3 is open at positions corresponding to the incident portion 2a and the output portion 2c, respectively, and the incident portion 2a and the output portion 2c are exposed from the housing 3. In this description of the embodiment, the portion of the housing 3 that covers the end surface 2e of the light guide 2 is referred to as the end cover portion 31.

[0035] The housing 3 functions as a light-shielding cover that prevents ambient light La from entering the portion of the light guide 2 that is covered by the housing 3. This ambient light La is light from outside the light guide 2, and the aforementioned ambient light L1 is a type of ambient light La.

[0036] As described above, the housing 3 functions as a light-shielding cover, so it is preferable that the opaque portion of the housing 3 be made of a black light-shielding material with a visible light absorption rate of a predetermined value or higher. For example, both the inner and outer surfaces of the opaque portion of the housing 3 are matte black. In this embodiment, the entire housing 3 is opaque. The matte black surface of the housing 3 may be achieved by the base material of the housing 3 itself, or by painting the surface.

[0037] Furthermore, the end cover portion 31 of the housing 3 has a corner portion 311 located at one corner of the light guide unit 10 in the first direction D1 and one corner of the second direction D2. This corner portion 311 of the light guide unit 10 forms a corner of the light guide unit 10, as well as a corner of the end cover portion 31. The end cover portion 31 extends from the portion overlapping the end surface 2e in the second direction D2, through the corner portion 311, to cover the tip 22c of the first emission prism portion 221.

[0038] Furthermore, the terminal cover portion 31 has a corner extension outer surface 312 that occupies a portion of the outer surface of the light guide unit 10. That is, the corner extension outer surface 312 is formed as part of the terminal cover portion 31. The corner extension outer surface 312 extends from the corner portion 311 to the other side of the second direction D2, and the other side of the corner extension outer surface 312 that is in the second direction D2 is formed as an outer surface facing one side of the first direction D1.

[0039] In detail, the corner extension outer surface 312 includes a curved surface portion that extends from one side to the other side of the first direction D1 while curving toward the other side of the second direction D2 at the corner 311 with a radius of curvature greater than or equal to a predetermined standard value Br (hereinafter referred to as the corner radius standard value Br). In other words, the curved surface portion of the corner extension outer surface 312 is formed as a corner R surface having a radius greater than or equal to the corner radius standard value Br when viewed in the direction along the third direction D3. For example, in this embodiment, the corner extension outer surface 312 is composed of the corner R surface, which is the curved surface portion, and a planar extension surface that extends a short distance from the corner R surface toward the other side of the second direction D2 and faces toward one side of the first direction D1. The corner extension outer surface 312 extends linearly along the third direction D3 while maintaining its surface configuration having the corner R surface and the extension surface.

[0040] The above-mentioned corner radius standard value Br is defined in a prescribed official standard, such as the safety standards for road transport vehicles. In other words, it is preferable that the prescribed standard that defines the corner radius standard value Br is a safety standard that ensures the safety of occupants, including the observer 70. Specifically, the corner radius standard value Br is set at 3.2 mm, in accordance with the content of the section on passenger equipment in the safety standards for road transport vehicles. That is, in this embodiment, the radius of curvature of the convex curved portion of the corner extension outer surface 312 is 3.2 mm or more. Note that, as of the filing date of this application, safety standards concerning blind spot assist devices have not yet been established, so the corner radius standard value Br of 3.2 mm is a value borrowed from the technical standards for impact absorption of sun visors in the safety standards for road transport vehicles.

[0041] As shown in Figures 2 to 4, the louver 4 has multiple vanes 41 held by the housing 3. Specifically, each of the vanes 41 is fixed to the housing 3. The vanes 41 are flat and are arranged on one side in the first direction D1 relative to the injection section 2c.

[0042] Furthermore, the multiple vanes 41 are formed in such a way that they suppress the incidence of ambient light La into the ejection section 2c while not obstructing the ejected light L3 directed from the ejection surface 22a of the ejection prism section 22 toward the viewer 70. For example, the multiple vanes 41 each extend outwards along the direction of the ejected light L3 directed from the ejection section 2c toward a predetermined assumed position of the viewer 70's eye. In addition, all of the multiple vanes 41 have a matte black finish across their entire surface, similar to the surface of the housing 3.

[0043] Specifically, the multiple slats 41 are arranged in a second direction D2 with intervals between them, and each extends along a third direction D3. The multiple slats 41 are arranged parallel or approximately parallel to each other, and each of the multiple slats 41 is inclined with respect to the first direction D1 such that the slats on one side of the first direction D1 are positioned closer to the one side of the second direction D2. As a result, the multiple slats 41 are arranged parallel or approximately parallel to the line of sight from the viewer 70 to the ejection section 2c, thus minimizing the obstruction of the ejection section 2c from the viewer 70. In this description of the embodiment, the slat 41 located on the furthest side of the second direction D2 among the multiple slats 41 of the louver 4 may be referred to as the terminal slat 42.

[0044] Furthermore, each of the multiple vanes 41 has a vane front edge portion 411 provided on one side in the first direction D1, and a vane rear edge portion 412 provided on the other side in the first direction D1. The vane front edge portion 411 and the vane rear edge portion 412 each extend linearly along the third direction D3.

[0045] Furthermore, the surface 411a of the vane front edge 411 is curved with a radius of curvature greater than or equal to the corner radius standard value Br in a cross section perpendicular to the third direction D3, which is the direction in which the vane front edge 411 extends, i.e., in the cross section shown in Figure 2. In short, the surface 411a of the vane front edge 411 is curved with a radius of curvature of 3.2 mm or more. In this description of the embodiment, the vane front edge 411 of the terminal vane 42 among the vane front edges 411 of the multiple vanes 41 may be referred to as the terminal vane front edge 421. The terminal vane front edge 421 is located on one side of the first direction D1 and the other side of the second direction D2 from the corner 311 of the light guide unit 10.

[0046] Furthermore, as shown in Figures 2 and 5, the inter-unit spacing Dx of the multiple vanes 41 is always less than the virtual sphere diameter Dsp, which is the diameter Dsp of the virtual sphere shape 73. The multiple vanes 41 prevent the virtual sphere shape 73 from passing between the multiple vanes 41 and contacting the ejection prism section 22 from one side in the first direction D1 relative to the multiple vanes 41.

[0047] The virtual spherical shape 73 is defined in the aforementioned standard that defines the corner radius standard value Br. More specifically, the virtual spherical shape 73 is defined as a spherical rigid head model in the section on passenger equipment in the safety standards for road transport vehicles, so the virtual spherical diameter Dsp in this embodiment is set to 165 mm in accordance with the safety standards for road transport vehicles. As mentioned above, since safety standards for blind spot assist devices have not yet been established at the time of filing this application, the virtual spherical diameter Dsp of 165 mm is a value borrowed from the technical standards for impact absorption of sun visors in the safety standards for road transport vehicles.

[0048] Furthermore, contact between the end vane 42 and the corner extension outer surface 312 of the end cover 31 is prevented from the virtual spherical shape 73 contacting the injection prism portion 22 of the injection section 2c from one side in the first direction D1. More specifically, the louvers 4 are positioned such that the virtual spherical shape 73 is away from all of the injection prism portions 22 of the injection section 2c in the predetermined arrangement shown in Figure 2. This predetermined arrangement is the state in which the virtual spherical shape 73 is closest to the injection prism portion 22 while in contact with the end vane 42 and the corner extension outer surface 312 without intersecting any of the vanes 41. In this predetermined arrangement, the virtual spherical shape 73 is in contact with the leading edge portion 421 of the end vane 42.

[0049] As shown in Figures 2 and 4, the positions of the virtual spherical shape 73 in the first direction D1 and the second direction D2 in the predetermined arrangement remain constant even when the virtual spherical shape 73 is displaced in the third direction D3. This is because the corner extension outer surface 312 and the terminal side vane front edge 421 extend linearly along the third direction D3. Point P1 in Figure 4 is the point of contact between the virtual spherical shape 73 and the corner extension outer surface 312, and point P2 is the point of contact between the virtual spherical shape 73 and the terminal side vane front edge 421.

[0050] In order to achieve a configuration in which the above-described virtual spherical shape 73 is separated from all the ejection prism sections 22 in a predetermined arrangement, the following relationship F2 holds true in the optical device 1 of this embodiment. Dmx <Dsp+Pe / 2 ···(F2)

[0051] As shown in Figure 2, in the above equation F2, Dsp is the diameter of the virtual spherical shape 73, and Pe is the pitch between the first ejection prism section 221 and the second ejection prism section 222 in the second direction D2. Also, Dmx is the diameter of the largest virtual sphere Fs that satisfies all of the following conditions [1] to [4]. [1] The virtual sphere Fs is provided on one side in the first direction D1 with respect to the corner extension outer surface 312. [2] The virtual sphere Fs has its center Cfs at the same position in the second direction D2 as the outermost point Pz of the corner extension outer surface 312. The outermost point Pz is the point located on the outermost side in the first direction D1 of the curved portion (in other words, the corner R surface) of the corner extension outer surface 312. [3] The virtual sphere Fs passes through the outermost point Pz of the corner extension outer surface 312. [4] The virtual sphere Fs is in contact with the leading edge 421 of the terminal vane. In this embodiment, the virtual spherical surface Fs is in contact with the leading edge 421 of the terminal side vane at the vane contact point Pa in Figure 2.

[0052] Here, the reason why the above relationship F2 holds true, resulting in a configuration where the virtual spherical shape 73 is separated from all the ejection prism sections 22 in a predetermined arrangement, will be explained using the reference example in Figure 6. In the reference example in Figure 6, compared to the embodiment in Figure 2, the housing 3 is absent, and the farthest point Pz is located at the tip 22c of the first ejection prism section 221. The largest virtual sphere Fs that satisfies all of the above conditions [1] to [4] is shown. And the above relationship F2 also holds true in the reference example in Figure 6.

[0053] In the reference example of Figure 6, if we assume that the relationship F3 below holds true, then the following can be said about the arrangement of the virtual spherical shape 73. That is, in that case, if the virtual spherical shape 73 is arranged so that it is in contact with the first ejection prism section 221 at the farthest point Pz and also in contact with the leading edge 421 of the terminal vane, it will also be in contact with the tip 22c of the second ejection prism section 222. Dmx = Dsp + Pe / 2 ... (F3)

[0054] However, in the reference example of Figure 6, the relationship of the inequality F2 above holds, so if the virtual spherical shape 73 is positioned so that it is in contact with the first ejection prism section 221 and the leading edge section 421 of the terminal vane at the far end point Pz, it will move away from the second ejection prism section 222.

[0055] Furthermore, in this embodiment shown in Figure 2, if the virtual spherical shape 73 is positioned to be in contact with the corner extension outer surface 312 and the terminal vane front edge 421 in the predetermined arrangement, it will be further away from the second ejection prism section 222 than in the arrangement shown in Figure 6. Also, in this embodiment, the terminal cover section 31 extends to cover the tip 22c of the first ejection prism section 221. Thus, in this embodiment shown in Figure 2, if the relationship of equation F2 above holds, it can be said that a configuration is achieved in which the virtual spherical shape 73 is far enough away from all the ejection prism sections 22 in the predetermined arrangement.

[0056] Next, the effects and advantages of the optical device 1 of this embodiment will be explained using the first to fifth comparative examples shown in Figures 7 to 11.

[0057] The optical device of the first comparative example shown in Figure 7 has the same light guide 2 as in this embodiment, but lacks the housing 3 and louvers 4, and is otherwise identical to the optical device 1 of this embodiment. The optical device of the second comparative example shown in Figure 8 lacks the first ejection prism section 221 of the light guide 2 of the optical device of the first comparative example, and has a corner R shape formed at the boundary between the ejection section 2c and the end surface 2e. The optical device of the third comparative example shown in Figure 9 has the same light guide 2 and housing 3 as in this embodiment, but lacks the louvers 4, and is otherwise identical to the optical device 1 of this embodiment. As shown in Figures 7 to 9, these first to third comparative examples have the problem that the virtual spherical shape 73, which is a spherical rigid head model, easily comes into contact with the ejection prism section 22 from one side in the first direction D1.

[0058] Furthermore, the optical device of the fourth comparative example in Figure 10 includes a light guide 2 and a louver 4, but does not have a housing 3, and all of the multiple vanes 41 of the louver 4 are positioned on the other side of the second direction D2 from the first ejection prism section 221. Except for these points, the optical device of the fourth comparative example is the same as the optical device 1 of this embodiment. As shown in Figure 10, this fourth comparative example has the problem that a virtual spherical shape 73 can easily come into contact with the first ejection prism section 221 and other ejection prism sections 22 in its vicinity from one side of the first direction D1.

[0059] Furthermore, unlike the optical device of the fourth comparative example, the optical device of the fifth comparative example shown in Figure 11 has multiple vanes 41, including a vane 41 extending diagonally from the first ejection prism section 221 to one side in the second diagonal direction D2. Except for this point, the optical device of the fifth comparative example is the same as the optical device of the fourth comparative example. In this fifth comparative example, as shown in Figure 11, the louver 4 prevents the virtual spherical shape 73 from contacting the multiple ejection prism sections 22 of the ejection section 2c from one side in the first direction D1. However, the fifth comparative example has the problem that the vane 41 located on the furthest side in the second direction D2 protrudes toward the viewer 70, which can be an obstruction. In addition, there is a concern that the protruding vane 41, which is an obstruction to the viewer 70, may obstruct the viewer 70's field of vision in the fifth comparative example.

[0060] The optical device 1 of this embodiment is configured to solve the problems of the optical devices of the first to fifth comparative examples described above. For example, according to this embodiment, as shown in Figure 2, the corner extension outer surface 312 includes a curved portion that extends from the other side to the one side of the first direction D1 while curving to the other side of the second direction D2 at the corner 311 with a radius of curvature greater than or equal to a predetermined corner radius standard value Br. The louvers 4 are arranged such that the virtual spherical shape 73 is away from all of the ejection prism portions 22 of the ejection portion 2c in a predetermined arrangement state. This predetermined arrangement state is the state in which the virtual spherical shape 73 is in contact with the terminal side vane 42 and the corner extension outer surface 312 without intersecting any of the multiple vane plates 41, and is closest to the ejection prism portion 22.

[0061] Therefore, for example, the corners 311 of the light guide unit 10 are rounded, and the virtual spherical shape 73 cannot come into contact with the tip 22c of any of the ejection prism sections 22 from the viewer 70 side. Furthermore, since both the corner radius standard value Br and the virtual spherical shape 73 are defined in a common predetermined standard, it is possible to ensure the safety of the viewer 70 by using the virtual spherical shape 73 and the corner radius standard value Br defined in that common predetermined standard with the louvers 4.

[0062] Furthermore, by utilizing the corner extension outer surface 312 in addition to the vane 41, it is possible to prevent the virtual spherical shape 73 from coming into contact with the ejection prism section 22. Therefore, in this embodiment, for example, compared with the fifth comparative example in Figure 11, the vane 41 can be positioned further away from the viewer 70, so that the vane 41 can be positioned so that it does not obstruct the viewer 70. Also, since multiple vane 41 are positioned so as not to obstruct the viewer 70, there is no concern that they will obstruct the viewer 70's field of vision. In this way, the problems described above in the first to fifth comparative examples are solved in this embodiment.

[0063] (1) Furthermore, according to this embodiment, as shown in Figure 2, the emission section 2c has multiple flat surfaces 23 that reflect a portion of the incident light L2 into the interior of the light guide 2, in addition to the multiple emission prism sections 22. The light guide 2 has a reflective surface 2d, which is formed as the outer surface of the light guide 2 facing the other side of the first direction D1, and reflects the incident light L2 reflected by the multiple flat surfaces 23 towards the emission section 2c. Therefore, it is possible to guide the incident light L2 in the second direction D2 by internal reflection in the light guide 2.

[0064] (2) Furthermore, according to this embodiment, as shown in Figure 2, the housing 3 has an end cover portion 31, and the corner extension outer surface 312 is formed as part of the end cover portion 31. Therefore, it is not necessary to form a corner R surface with a radius of curvature greater than or equal to the corner radius standard value Br using the light guide 2, and thus it is possible to reduce the constraints on the shape of the light guide 2.

[0065] (3) Furthermore, in the optical device 1 of this embodiment, the relationship of equation F2 above holds true. Therefore, by assuming the largest virtual sphere Fs that satisfies all of the above conditions [1] to [4], the arrangement of the louvers 4 can be determined such that the virtual spherical shape 73 in Figure 2 is separated from all of the ejection prism parts 22 of the ejection part 2c in the predetermined arrangement state.

[0066] (4) Furthermore, according to this embodiment, as shown in Figures 2 and 5, the mutual spacing Dx of the multiple vanes 41 is all less than the diameter Dsp of the virtual spherical shape 73. The multiple vanes 41 prevent the virtual spherical shape 73 from passing between the multiple vanes 41 and contacting any of the multiple ejection prism sections 22 from one side in the first direction D1 relative to the multiple vanes 41. Therefore, in addition to preventing the virtual spherical shape 73 from passing between the corner extension outer surface 312 of the end cover section 31 and the end vane 42 and contacting the ejection prism section 22, it is also possible to prevent the virtual spherical shape 73 from passing between the multiple vanes 41 and contacting the ejection prism section 22.

[0067] (5) Furthermore, according to this embodiment, each of the multiple vanes 41 has a vane front edge portion 411 provided on one side in the first direction D1. The surface 411a of the vane front edge portion 411 is curved with a radius of curvature greater than or equal to the corner radius standard value Br in a cross section perpendicular to the third direction D3, which is the direction in which the vane front edge portion 411 extends, i.e., in the cross section of Figure 2. Therefore, it is possible to avoid the vane front edge portion 411 having sharp corners. In other words, it is possible to ensure the safety of a viewer 70 who may come into contact with the vane front edge portion 411 by using a corner radius standard value Br defined in a predetermined standard that is common to a hypothetical spherical shape 73.

[0068] (6) Furthermore, according to this embodiment, the opaque portion of the housing 3 and the multiple vanes 41 are matte black. Therefore, compared to the case where they have a white surface instead of a matte black surface, for example, unwanted light incidence onto the light guide 2 can be suppressed.

[0069] (7) Furthermore, according to this embodiment, the radius of curvature of the convex curved portion of the corner extension outer surface 312 is 3.2 mm or more. Therefore, it is possible to ensure the safety of a person 70 who may come into contact with the corner extension outer surface 312 in accordance with the safety standards for road transport vehicles.

[0070] (8) Furthermore, according to this embodiment, the diameter Dsp of the virtual spherical shape 73 is 165 mm. Therefore, it is possible to prevent the spherical rigid head model specified in the safety standards for road transport vehicles from coming into contact with the multiple pointed ejection prism sections 22 from one side in the first direction D1.

[0071] (Second Embodiment) Next, a second embodiment will be described. In this embodiment, the differences from the first embodiment described above will be mainly explained. Furthermore, parts that are the same as or equivalent to the above embodiment will be omitted or simplified in their description. The same applies to the descriptions of the embodiments described later.

[0072] As shown in Figures 2 and 12, each of the multiple vanes 41, including the terminal vane 42, extends in the third direction D3 while varying the vane width LL between the rear edge 412 and the front edge 411 of the vane. In each of the multiple vanes 41, the rear edge 412 extends linearly along the third direction D3, similar to the first embodiment.

[0073] Therefore, each of the multiple vane front edges 411, including the terminal vane front edge 421, extends in the third direction D3 while being displaced in the first direction D1. Thus, the largest hypothetical sphere Fs in Figure 2 that satisfies all of the above conditions [1] to [4] is in contact with the terminal vane front edge 421 at the point Pb where the terminal vane front edge 421 is most displaced to the other side of the first direction D1. The point Pb where the terminal vane front edge 421 is most displaced to the other side of the first direction D1 is also the point where the vane width LL is shortest among the terminal vane front edges 421.

[0074] (1) As described above, according to this embodiment, the virtual spherical surface Fs in Figure 2 contacts the leading edge 421 of the terminal vane at point Pb where the leading edge 421 of the terminal vane is most displaced to the other side in the first direction D1. Therefore, even when the leading edge 421 of the terminal vane extends in the third direction D3 while curving, the arrangement of the louvers 4 can be determined using the virtual spherical surface Fs such that the virtual spherical shape 73 in Figure 2 is separated from all of the ejection prism portions 22 of the ejection portion 2c in a predetermined arrangement state.

[0075] Except as described above, this embodiment is the same as the first embodiment. In this embodiment, the effects obtained from the configuration common to the first embodiment can be obtained in the same way as in the first embodiment.

[0076] (Third embodiment) Next, a third embodiment will be described. This embodiment will primarily describe the differences from the first embodiment described above.

[0077] As shown in Figures 13 and 14, in this embodiment as well, the housing 3 has an end cover portion 31 having the same shape as in the first embodiment. However, the end cover portion 31 in this embodiment has a transparent structure. For example, the end cover portion 31 in this embodiment is made of a material that is transparent and non-diffusive to visible light, such as acrylic resin, and is colorless and transparent throughout the entire end cover portion 31. Therefore, the corner extension outer surface 312 is also colorless and transparent. The parts of the housing 3 other than the end cover portion 31 are matte black and opaque, as in the first embodiment.

[0078] As described above, since the end cover portion 31 is transparent, a portion of the incident light L2 inside the light guide 2 is emitted from the end surface 2e of the light guide 2 through the end cover portion 31 to the outside of the light guide unit 10. In addition, both the inner and outer surfaces of the transparent end cover portion 31 are coated with an anti-reflective coating. This anti-reflective coating reduces light reflection from the end cover portion 31 itself, thereby preventing unwanted light from reaching the field of view of the viewer 70.

[0079] Although Figure 14 is not a cross-sectional view, the transparent portion of the housing 3 is hatched. Similarly, the perspective view described later, which is similar to Figure 14, also shows hatching on the transparent portion of the housing 3.

[0080] (1) As described above, according to this embodiment, the end cover portion 31 of the housing 3 has a transparent structure, and a portion of the incident light L2 in the light guide body 2 is emitted from the end surface 2e of the light guide body 2 through the end cover portion 31 to the outside of the light guide unit 10. Therefore, in addition to preventing the virtual spherical shape 73 from contacting the emission prism portion 22 by the end cover portion 31, the emitted light L3 from the end surface 2e of the light guide body 2 can be emitted without obstructing the light L3, which represents the outside scenery, and can reach the viewer 70.

[0081] Except as described above, this embodiment is the same as the first embodiment. In this embodiment, the effects obtained from the common configuration with the first embodiment can be obtained in the same way as in the first embodiment. Although this embodiment is a modification based on the first embodiment, it is also possible to combine this embodiment with the second embodiment described above.

[0082] (Fourth Embodiment) Next, a fourth embodiment will be described. This embodiment will primarily describe the differences from the first embodiment described above.

[0083] As shown in Figures 15 and 16, in this embodiment, the housing 3 does not have an end cover portion 31, and the end surface 2e of the light guide body 2 is exposed to the outside of the light guide unit 10 without being covered by the housing 3. Therefore, the end surface 2e of this embodiment has a corner portion 24 that corresponds to the corner portion 311 of the light guide unit 10 in the first embodiment, instead of the corner portion 311 of the light guide unit 10 in the first embodiment. Furthermore, the corner extension outer surface 25 of this embodiment, which corresponds to the corner extension outer surface 312 of the first embodiment, is formed as part of the end surface 2e of the light guide body 2.

[0084] In this embodiment, as described above, the corner extension outer surface 25 is formed on the light guide 2, so the ejection portion 2c of the light guide 2 does not include the first ejection prism portion 221 in Figure 2 among the multiple ejection prism portions 22. Therefore, in this embodiment, the second ejection prism portion 222 in the first embodiment becomes the ejection prism portion 22 located on the furthest side in the second direction D2 among the multiple ejection prism portions 22. Thus, in this embodiment, the second ejection prism portion 222 is called the terminal side ejection prism portion 222. This terminal side ejection prism portion 222 corresponds to the terminal side prism portion of this disclosure.

[0085] To confirm, the corner portion 24 of this embodiment has a configuration corresponding to the corner portion 311 of the first embodiment, and the extended corner outer surface 25 of this embodiment has a configuration corresponding to the extended corner outer surface 312 of the first embodiment. Therefore, for example, the corner portion 24 of this embodiment is located at the corner of the light guide unit 10 on one side in the first direction D1 and on one side in the second direction D2. Furthermore, the extended corner outer surface 25 of this embodiment extends from the corner portion 24 to the other side in the second direction D2, and on the other side of the extended corner outer surface 25 in the second direction D2, it is formed as the outer surface of the light guide unit 10 facing one side in the first direction D1. In addition, the extended corner outer surface 25 includes a curved portion that extends from the other side to one side in the first direction D1 while curving toward the other side in the second direction D2 at the corner portion 24 with a radius of curvature of Br or greater (specifically, a radius of curvature of 3.2 mm or more).

[0086] Furthermore, in this embodiment as well, the virtual spherical shape 73 is prevented from passing between the terminal vane 42 and the corner extension outer surface 25 from one side in the first direction D1 and contacting the injection prism portion 22 of the injection section 2c, similar to the first embodiment. In other words, in this embodiment, the louvers 4 are arranged such that the virtual spherical shape 73 is away from all of the injection prism portions 22 of the injection section 2c in the predetermined arrangement shown in Figure 15. And, as in the first embodiment, the predetermined arrangement is the state in which the virtual spherical shape 73 is closest to the injection prism portion 22 while in contact with the terminal vane 42 and the corner extension outer surface 25 without intersecting any of the multiple vane 41.

[0087] In order to achieve the configuration in which the above-described virtual spherical shape 73 is separated from all the ejection prism sections 22 in a predetermined arrangement, in this embodiment as in the first embodiment, the largest virtual spherical surface Fs that satisfies all of the above-described conditions [1] to [4] is assumed. And in the optical device 1 of this embodiment, the following relationship F4, which corresponds to the above-described equation F2, holds true. Dmx <Dsp+P1e / 2 ···(F4)

[0088] However, in the above formula F4 of this embodiment, P1e is the distance between the farthest point Pz in the second direction D2 and the tip 22c of the terminal side ejection prism section 222. The farthest point Pz of this embodiment is defined in the same way as the farthest point Pz of the first embodiment, but in that definition, the corner extension outer surface 312 of the first embodiment is read as the corner extension outer surface 25 of this embodiment. Also, the corner extension outer surface 312 in the above conditions [1] to [4] of the first embodiment is read as the corner extension outer surface 25 of this embodiment.

[0089] Furthermore, as shown in Figure 15, the outermost point Pz in this embodiment is at the same position as the tip 22c of the terminal side ejection prism section 222 in the first direction D1.

[0090] (1) As described above, according to this embodiment, the corner extension outer surface 25 is formed as part of the end surface 2e of the light guide body 2, and the end surface 2e is exposed to the outside of the light guide unit 10 without being covered by the housing 3. Therefore, the housing 3 has an open shape without a wall on one side in the second direction D2, so the housing 3 can be simplified.

[0091] (2) Furthermore, in the optical device 1 of this embodiment, the relationship of equation F4 above holds true. Therefore, similar to the first embodiment, by assuming the largest virtual spherical surface Fs that satisfies all of the above conditions [1] to [4], the arrangement of the louvers 4 can be determined such that the virtual spherical shape 73 in Figure 15 is separated from all of the ejection prism sections 22 of the ejection section 2c in the predetermined arrangement state.

[0092] Except as described above, this embodiment is the same as the first embodiment. In this embodiment, the effects obtained from the configuration common to the first embodiment can be obtained in the same way as in the first embodiment.

[0093] Although this embodiment is a modification based on the first embodiment, it is also possible to combine this embodiment with the second embodiment described above.

[0094] (Fifth embodiment) Next, a fifth embodiment will be described. This embodiment will primarily describe the differences from the third embodiment described above.

[0095] As shown in Figures 13, 17, and 18, the housing 3 of this embodiment has a one-side cover portion 32 that covers the light guide 2 on one side in the third direction D3 relative to the light guide 2, and a other-side cover portion 33 that covers the light guide 2 on the other side in the third direction D3 relative to the light guide 2. The housing 3 also has a one-side corner portion 34 provided between the one-side cover portion 32 and the end cover portion 31, connecting the one-side cover portion 32 and the end cover portion 31. In addition, the housing 3 also has a other-side corner portion 35 provided between the other-side cover portion 33 and the end cover portion 31, connecting the other-side cover portion 33 and the end cover portion 31. The one-side corner portion 34 and the other-side corner portion 35 are each formed to extend in the first direction D1. These features are the same in the third embodiment.

[0096] However, unlike the third embodiment, in this embodiment, the outer surface 34a of the corner portion 34 is a convex curved surface that smoothly connects continuously from the end cover portion 31 to the cover portion 32. This curved surface is curved with a radius of curvature greater than or equal to the corner radius standard value Br, and extends from the end cover portion 31 to the cover portion 32.

[0097] Similarly, the outer surface 35a of the other corner portion 35 is a convex curved surface that smoothly connects continuously from the end cover portion 31 to the other cover portion 33. This curved surface extends from the end cover portion 31 to the other cover portion 33 while curving with a radius of curvature greater than or equal to the corner radius standard value Br.

[0098] Furthermore, the corner portion 34 on one side and the corner portion 35 on the other side are colorless and transparent, just like the end cover portion 31.

[0099] As described above, according to this embodiment, the outer surface 34a of one corner portion 34 and the outer surface 35a of the other corner portion 35 are curved surfaces with a radius of curvature equal to or greater than the corner radius standard value Br. Therefore, it becomes easier to ensure the safety of the observer 70 on both sides of the third direction D3 relative to the housing 3.

[0100] Furthermore, since one corner portion 34 and the other corner portion 35 are transparent, it becomes possible to ensure visibility to one side and the other side in the third direction D3 relative to the housing 3.

[0101] Except as described above, this embodiment is the same as the third embodiment. In this embodiment, the effects obtained from the configuration common to the third embodiment can be obtained in the same way as in the third embodiment.

[0102] (Sixth Embodiment) Next, a sixth embodiment will be described. This embodiment will primarily describe the differences from the first embodiment described above.

[0103] As shown in Figures 19 and 20, in this embodiment, the multiple slats 41 of the louver 4 each extend along the slat extension direction D4, which is inclined with respect to the second direction D2 and the third direction D3 and perpendicular to the first direction D1. Therefore, among the multiple slats 41, some slats 41 reach the end position Px on one side of the second direction D2 in the louver 4, while others do not reach that end position Px.

[0104] Furthermore, in each of the multiple vane plates 41, the front edge 411 and the rear edge 412 of the vane plate extend linearly along the vane plate extension direction D4. In addition, in a cross section perpendicular to the vane plate extension direction D4, each of the multiple vane plates 41 is inclined with respect to the first direction D1 such that one side of the first direction D1 is positioned closer to one side of the second direction D2.

[0105] In this embodiment as well, the virtual spherical shape 73 in Figure 2 is prevented from passing through the louver 4 and the corner extension outer surface 312 from one side in the first direction D1 and contacting the injection prism portion 22 of the injection unit 2c, just as in the first embodiment. In other words, in this embodiment as well, the louver 4 is positioned so that the virtual spherical shape 73 is away from all of the injection prism portions 22 of the injection unit 2c in a predetermined configuration.

[0106] In this embodiment, the arrangement of each slat 41 differs from that of the first embodiment, and accordingly, the definition of the predetermined arrangement state of the virtual spherical shape 73 also differs from that of the first embodiment. That is, in this embodiment, the predetermined arrangement state is the state in which the virtual spherical shape 73 does not intersect with any of the multiple slats 41, but is in contact with one of the slats 41 and the corner extension outer surface 312, and is brought as close as possible to the ejection prism section 22. At this time, the slats 41 that the virtual spherical shape 73 is in contact with are two adjacent slats 41 out of the multiple slats 41 that reach the end position Px of the louver 4.

[0107] In order to achieve the configuration in which the above-described virtual spherical shape 73 is separated from all the ejection prism sections 22 in a predetermined arrangement, a virtual spherical surface Fs is assumed in this embodiment as in the first embodiment. In Figures 19 and 20, the virtual spherical surface Fs is shown with dot-like hatching to make it easier to understand.

[0108] Furthermore, in the optical device 1 of this embodiment, the relationship F2 described above holds true for the diameter Dmx of the virtual sphere Fs. However, the virtual sphere Fs is defined as the largest sphere that satisfies all of the above conditions [1] to [3] and the following condition [4-1]. [4-1] The virtual sphere Fs does not intersect with any of the multiple vanes 41, but is tangent to two adjacent vanes 43 and 44 of the multiple vanes 41, respectively.

[0109] As shown in Figures 19 and 20, the two adjacent slats 43 and 44 in the above condition [4-1] refer, more specifically, to one of the multiple slats 41 that are adjacent to each other: one slat 43 and the other slat 44. Both the one slat 43 and the other slat 44 are slats 41 that reach one end position Px in the second direction D2 of the louver 4. Furthermore, the virtual sphere Fs contacts the one slat 43 at a contact point Pc located midway along the leading edge 411 of the one slat 43. Conversely, the virtual sphere Fs contacts the other slat 44 at a contact point Pd located at the corner portion on one side of the leading edge 411 of the other slat 44 in the second direction D2.

[0110] (1) As described above, the relationship of equation F2 holds true in the optical device 1 of this embodiment. Therefore, by assuming the virtual spherical surface Fs described above, the arrangement of the louvers 4 can be determined so that the virtual spherical shape 73 in Figure 2 is separated from all of the ejection prism sections 22 of the ejection section 2c in a predetermined arrangement state, similar to the first embodiment.

[0111] Except as described above, this embodiment is the same as the first embodiment. In this embodiment, the effects obtained from the configuration common to the first embodiment can be obtained in the same way as in the first embodiment.

[0112] Although this embodiment is a modification based on the first embodiment, it is also possible to combine this embodiment with any of the second to fifth embodiments described above.

[0113] (Modified version of the sixth embodiment) This modified example is a modification in which the sixth embodiment is combined with the fourth embodiment. That is, in this modified example, the louver 4 in the fourth embodiment is replaced with that of the sixth embodiment, and the other configurations are the same as in the fourth embodiment. In this modified example, the virtual sphere Fs is the largest sphere that satisfies all of the above conditions [1] to [3] and condition [4-1], as in the sixth embodiment. However, for the diameter Dmx of the virtual sphere Fs, the above relationship F4 is given instead of the above equation F2. Furthermore, in the definition of the outermost point Pz, the above conditions [1] to [3], and the above condition [4-1] in this modified example, the corner extension outer surface 312 of the sixth embodiment is read as the corner extension outer surface 25 of the fourth embodiment, as in the fourth embodiment.

[0114] (Other embodiments) (1) In each of the embodiments described above, as shown in Figure 1, the optical device 1 is an in-vehicle device, but it may also be mounted on something other than a vehicle.

[0115] (2) In each of the embodiments described above, the louver 4 has multiple slats 41, as shown in Figure 2, for example, but this is just one example. For example, if the dimensions of the light guide 2 in the second direction D2 are short, it is conceivable that the louver 4 has only one slat 41.

[0116] (3) In each of the embodiments described above, for example as shown in Figure 2, the corner extension outer surface 312 is composed of a corner radius surface and an extension surface that extends from the corner radius surface to the other side in the second direction D2, when viewed in the direction along the third direction D3, but this is just one example. For example, the extension surface may be omitted, and the corner extension outer surface 312 may be composed only of the corner radius surface.

[0117] (4) In each of the embodiments described above, for example, the virtual spherical shape 73 and the corner radius standard value Br shown in Figure 2 are defined in a predetermined standard called the Road Transport Vehicle Safety Standards, but this is just one example. The standard that defines the virtual spherical shape 73 and the corner radius standard value Br may be a standard other than the Road Transport Vehicle Safety Standards.

[0118] (5) In the fourth embodiment described above, as shown in Figure 15, the farthest point Pz on the corner extension outer surface 25 is at the same position as the tip 22c of the terminal side ejection prism section 222 in the first direction D1, but this is just one example. For example, the corner extension outer surface 25 may be formed such that the farthest point Pz is located on one side of the first direction D1 than the tip 22c of the terminal side ejection prism section 222.

[0119] (6) The present disclosure is not limited to the embodiments described above and can be implemented in various modified forms. Furthermore, the embodiments described above are not unrelated to each other and can be combined as appropriate, except in cases where the combination is clearly impossible.

[0120] Furthermore, it goes without saying that, in each of the above embodiments, the elements constituting the embodiment are not necessarily essential unless explicitly stated to be particularly essential or unless they are clearly considered essential in principle. Also, in each of the above embodiments, when numerical values ​​such as the number, numerical values, quantities, or ranges of the components of the embodiment are mentioned, the embodiment is not limited to those specific numbers unless explicitly stated to be particularly essential or unless it is clearly limited to a specific number in principle. Also, in each of the above embodiments, when the material, shape, positional relationship, etc. of the components are mentioned, the embodiment is not limited to those material, shape, positional relationship, etc. unless explicitly stated or unless it is clearly limited to a specific material, shape, positional relationship, etc. in principle.

[0121] (Perspective of this disclosure) The above disclosure can be understood from the following perspectives, for example. [First point of view] An optical device, A light guide (2) made of a translucent material has an incident portion (2a) into which ambient light (L1) is incident, an ejection portion (2c) that forms an outer surface on one side in a first direction (D1), and an end portion (2e) that forms an outer surface on one side in a second direction (D2) perpendicular to the first direction, which is opposite to the incident portion side. A holding member (3) that partially covers the light guide and holds the light guide, The injection section is positioned on one side in the first direction, and the louver (4) is held by the holding member and has one or more vanes (41, 42, 43, 44) that suppress the incidence of ambient light (La) to the injection section. The ejection section has a plurality of prism sections (22, 221, 222) which are formed in a protruding manner in line with the second direction and eject a portion of the incident light (L2) that has entered the interior of the light guide from the incident section to the outside of the light guide. The light guide and the holding member constitute a light guide unit (10). The light guide unit has a corner portion (24, 311) located on one side in the first direction and one side in the second direction, and a corner extension outer surface (25, 312) that extends from the corner portion to the other side in the second direction and is formed as an outer surface facing the one side in the first direction on the other side in the second direction. The corner extension outer surface includes a curved portion that extends from the other side in the first direction to the one side while curving toward the other side in the second direction with a radius of curvature of a predetermined standard value (Br) or greater at the corner, and is formed as part of the end portion or as part of the end cover portion (31) of the retaining member that covers the end portion. The louvers are arranged such that, when the virtual spherical shape (73) defined in the prescribed standard is in contact with the louvers and the corner extension outer surface without intersecting any of the one or more slats, and is closest to the plurality of prism portions, the virtual spherical shape moves away from the plurality of prism portions. An optical device in which the aforementioned standard values ​​are also defined in the aforementioned specified standard. [Second perspective] In addition to the plurality of prism sections, the emission section has a plurality of flat surfaces (23) that reflect a portion of the incident light into the interior of the light guide. The optical apparatus according to the first aspect, wherein the light guide has a reflective surface (2d) formed as an outer surface facing the other side in the first direction, which reflects the incident light reflected by the plurality of flat surfaces toward the emission part. [Third perspective] The holding member has the terminal cover portion, The corner extending outer surface (312) is formed as a part of the terminal cover portion, the optical device according to the first or second aspect. [Fourth aspect] The terminal cover portion has a transparent configuration, A part of the incident light in the light guide is emitted from the terminal portion through the terminal cover portion to the outside of the light guide unit, the optical device according to the third aspect. [Fifth aspect] The one or more vanes extend along a third direction (D3) perpendicular to the first direction and the second direction, and include a terminal side vane (42) disposed on the most one side in the second direction among the one or more vanes. The terminal side vane has a vane front edge portion (421) extending in the third direction and provided on the one side in the first direction. The plurality of prism portions include a first prism portion (221) disposed on the most one side in the second direction among the plurality of prism portions, and a second prism portion (222) adjacent to the first prism portion. The terminal cover portion extends so as to cover the tip (22c) of the first prism portion. When the spherical center (Cfs) is located at the same position in the second direction as the most one point (Pz) located on the most one side in the first direction of the curved surface portion of the corner extending outer surface, and the virtual spherical shape having the largest diameter (Fs) that is provided on the one side in the first direction with respect to the corner extending outer surface and passes through the most one point and contacts the vane front edge portion is defined as Dmx, the diameter of the virtual spherical shape is defined as Dsp, and the pitch between the first prism portion and the second prism portion in the second direction is defined as Pe, the relationship of "Dmx < Dsp + Pe / 2" holds, the optical device according to the third or fourth aspect. [Sixth aspect] The corner extending outer surface (25) is formed as a part of the terminal portion, The terminal portion is exposed to the outside of the light guide unit, the optical device according to the first or second aspect. [Seventh aspect] The one or more vanes extend along a third direction (D3) perpendicular to the first direction and the second direction, and include a terminal vane (42) disposed on the one side in the second direction among the one or more vanes. The terminal vane has a vane leading edge portion (421) that extends in the third direction and is provided on the one side in the first direction. The plurality of prism portions include a terminal prism portion (222) disposed on the one side in the second direction among the plurality of prism portions. Among the curved surface portions of the corner extending outer surface, a spherical center (Cfs) is provided on the one side in the first direction with respect to the corner extending outer surface and at the same position in the second direction as the outermost one point (Pz) located on the one side in the first direction. The diameter of the largest virtual spherical surface (Fs) that passes through the outermost one point and contacts the vane leading edge portion is defined as Dmx, the diameter of the virtual spherical shape is defined as Dsp, and the distance between the outermost one point and the tip (22c) of the terminal prism portion in the second direction is defined as P1e. In this case, the relationship of "Dmx < Dsp + P1e / 2" holds. The outermost one point is located at the same position as the tip of the terminal prism portion in the first direction, or is disposed at a position on the one side in the first direction with respect to the tip of the terminal prism portion. The optical device according to the sixth aspect. [Eighth aspect] The vane leading edge portion extends in the third direction while being displaced in the first direction. The virtual spherical surface contacts the vane leading edge portion at a location (Pb) where the vane leading edge portion is most displaced to the other side in the first direction. The optical device according to the fifth or seventh aspect. [Ninth aspect] The one or more vanes are a plurality of vanes arranged with an interval therebetween. Each of the intervals between the plurality of vanes is less than the diameter (Dsp) of the virtual spherical shape. The plurality of vanes prevent the virtual spherical shape from contacting any of the plurality of prism portions through the intervals between the plurality of vanes from the one side in the first direction. The optical device according to any one of the first to eighth aspects. [Tenth aspect] The above one or more vanes are a plurality of vanes arranged with an interval therebetween. The plurality of vanes each have a vane leading edge portion (411) provided on one side in the first direction. The surface (411a) of the vane leading edge portion is curved with a radius of curvature equal to or greater than the standard value in a cross-section perpendicular to the direction in which the vane leading edge portion extends. The optical device according to any one of the first, second, third, fourth, and sixth aspects. [Eleventh aspect] The opaque portion of the holding member and the one or more vanes are matte black. The optical device according to any one of the first to tenth aspects. [Twelfth aspect] The above one or more vanes are a plurality of vanes arranged with an interval therebetween. The plurality of vanes each extend in a direction (D4) that is inclined with respect to the second direction and perpendicular to the first direction. The plurality of prism portions include a first prism portion (221) arranged on the most one side in the second direction among the plurality of prism portions and a second prism portion (222) adjacent to the first prism portion. The terminal cover portion extends so as to cover the tip (22c) of the first prism portion. The spherical center (Cfs) is located at the same position in the second direction as the most one point (Pz) located on the most one side in the first direction among the curved surface portions of the corner extending outer surface. It is provided on the one side in the first direction with respect to the corner extending outer surface, passes through the most one point, and does not intersect any of the plurality of vanes. The diameter of the largest virtual sphere (Fs) that contacts two adjacent vanes (43, 44) among the plurality of vanes is defined as Dmx, the diameter of the virtual spherical shape is defined as Dsp, and the pitch between the first prism portion and the second prism portion in the second direction is defined as Pe. The relationship of "Dmx < Dsp + Pe / 2" holds. The optical device according to the third or fourth aspect. [Thirteenth aspect] The above one or more vanes are a plurality of vanes arranged with an interval therebetween. The plurality of blade plates are inclined with respect to the second direction and extend respectively in one direction (D4) perpendicular to the first direction. The plurality of prism parts include a terminal side prism part (222) arranged on the most one side in the second direction among the plurality of prism parts. The spherical center (Cfs) is located at the same position in the second direction as the most one point (Pz) located on the most one side in the first direction of the curved surface part of the corner extended outer surface, and is provided on the most one side in the first direction with respect to the corner extended outer surface, passes through the most one point, and does not intersect any of the plurality of blade plates. Let the diameter of the largest virtual sphere (Fs) that contacts two adjacent blade plates (43, 44) among the plurality of blade plates be Dmx, the diameter of the virtual spherical shape be Dsp, and the distance between the most one point and the tip (22c) of the terminal side prism part in the second direction be P1e. In this case, the relationship of "Dmx < Dsp + P1e / 2" holds. The optical device according to the sixth aspect, wherein the most one point is located at the same position as the tip of the terminal side prism part in the first direction, or is arranged at a position on the most one side in the first direction with respect to the tip of the terminal side prism part. [The 14th aspect] The optical device according to any one of the first to 13th aspects, wherein the radius of curvature of the curved surface part of the corner extended outer surface is 3.2 mm or more. [The 15th aspect] The optical device according to any one of the first to 14th aspects, wherein the diameter (Dsp) of the virtual spherical shape is 165 mm.

Explanation of symbols

[0122] 2 Light guide 2a Incident part 2c Exit part 2e End face (end part) 3 Housing (holding member) 4 Louver 22 Exit prism part (prism part) 25, 312 Corner extended outer surface 41 Blade plate 73 Virtual spherical shape

Claims

1. An optical device, A light guide (2) made of a translucent material has an incident portion (2a) into which ambient light (L1) is incident, an ejection portion (2c) that forms an outer surface on one side in a first direction (D1), and an end portion (2e) that forms an outer surface on one side in a second direction (D2) perpendicular to the first direction, which is opposite to the incident portion side. A holding member (3) that partially covers the light guide and holds the light guide, The injection section is positioned on one side in the first direction, and the louver (4) is held by the holding member and has one or more vanes (41, 42, 43, 44) that suppress the incidence of ambient light (La) to the injection section. The ejection section has a plurality of prism sections (22, 221, 222) which are formed in a protruding manner in line with the second direction and eject a portion of the incident light (L2) that has entered the interior of the light guide from the incident section to the outside of the light guide. The light guide and the holding member constitute a light guide unit (10). The light guide unit has a corner portion (24, 311) located on one side in the first direction and one side in the second direction, and a corner extension outer surface (25, 312) that extends from the corner portion to the other side in the second direction and is formed as an outer surface facing the one side in the first direction on the other side in the second direction. The corner extension outer surface includes a curved portion that extends from the other side in the first direction to the one side while curving toward the other side in the second direction with a radius of curvature of a predetermined standard value (Br) or greater at the corner, and is formed as a part of the end portion or as a part of the end cover portion (31) of the retaining member that covers the end portion. The louvers are arranged such that, when the virtual spherical shape (73) defined in the prescribed standard is in contact with the louvers and the corner extension outer surface without intersecting any of the one or more slats, and is closest to the plurality of prism portions, the virtual spherical shape moves away from the plurality of prism portions. An optical device in which the aforementioned standard values ​​are also defined in the aforementioned specified standard.

2. In addition to the plurality of prism sections, the emission section has a plurality of flat surfaces (23) that reflect a portion of the incident light into the interior of the light guide. The optical apparatus according to claim 1, wherein the light guide has a reflective surface (2d) formed as an outer surface facing the other side in the first direction, which reflects the incident light reflected by the plurality of flat surfaces toward the emission part.

3. The retaining member has the end cover portion, The optical apparatus according to claim 1 or 2, wherein the corner extension outer surface (312) is formed as part of the end cover portion.

4. The aforementioned end cover portion has a transparent structure. The optical apparatus according to claim 3, wherein a portion of the incident light within the light guide body is emitted from the terminal portion through the terminal cover portion to the outside of the light guide unit.

5. The one or more vanes extend along a third direction (D3) perpendicular to the first and second directions, and include an end vane (42) located on the side furthest to the second direction among the one or more vanes. The terminal vane extends in the third direction and has a vane front edge portion (421) provided on one side in the first direction. The plurality of prism sections include a first prism section (221) located furthest to the one side in the second direction among the plurality of prism sections, and a second prism section (222) adjacent to the first prism section. The aforementioned end cover portion extends so as to cover the tip (22c) of the first prism portion, The optical apparatus according to claim 3, wherein the largest virtual sphere (Fs) is provided on the one side of the corner extension outer surface in the first direction, passing through the one point (Pz) located on the one side in the first direction, has a spherical center (Cfs) at the same position in the second direction as the furthest point (Pz) located on the one side of the corner extension outer surface, and is in contact with the leading edge of the vane, and its diameter is Dmx, the diameter of the virtual sphere is Dsp, and the pitch between the first prism portion and the second prism portion in the second direction is Pe, such that the relationship "Dmx < Dsp + Pe / 2" holds true.

6. The corner extension outer surface (25) is formed as part of the end portion, The optical apparatus according to claim 1 or 2, wherein the terminal portion is exposed to the outside of the light guide unit.

7. The one or more vanes extend along a third direction (D3) perpendicular to the first and second directions, and include an end vane (42) located on the side furthest to the second direction among the one or more vanes. The terminal vane extends in the third direction and has a vane front edge portion (421) provided on one side in the first direction. The plurality of prism sections includes a terminal prism section (222) that is located furthest to the one side in the second direction among the plurality of prism sections, If the diameter of the largest virtual sphere (Fs) that has a spherical center (Cfs) at the same position in the second direction as the furthest point (Pz) located on the curved outer surface of the corner extension, is provided on the one side of the corner extension in the first direction, passes through the furthest point, and touches the leading edge of the vane, is Dmx, the diameter of the virtual sphere is Dsp, and the distance between the furthest point and the tip (22c) of the terminal prism portion in the second direction is P1e, then the relationship "Dmx < Dsp + P1e / 2" holds true. The optical apparatus according to claim 6, wherein the farthest point is located at the same position as the tip of the terminal prism portion in the first direction, or at a position on one side of the first direction relative to the tip of the terminal prism portion.

8. The leading edge of the vane extends in the third direction while being displaced in the first direction. The optical apparatus according to claim 5, wherein the virtual sphere is in contact with the leading edge of the vane at the point (Pb) where the leading edge of the vane is most displaced toward the other side in the first direction.

9. The aforementioned one or more fins refer to multiple fins arranged at intervals from one another. The intervals between the aforementioned multiple vanes are all less than the diameter (Dsp) of the virtual spherical shape. The optical apparatus according to claim 1 or 2, wherein the plurality of vanes prevent the virtual spherical shape from contacting any of the plurality of prism portions by passing between the plurality of vanes from one side in the first direction.

10. The aforementioned one or more fins refer to multiple fins arranged at intervals from one another. Each of the aforementioned plurality of vanes has a vane front edge portion (411) provided on one side in the first direction, The optical device according to claim 1 or 2, wherein the surface (411a) of the leading edge of the vane is curved with a radius of curvature greater than or equal to the standard value in a cross section perpendicular to the direction in which the leading edge of the vane extends.

11. The optical device according to claim 1 or 2, wherein the opaque portion of the holding member and the one or more vanes are matte black.

12. The aforementioned one or more fins refer to multiple fins arranged at intervals from one another. Each of the aforementioned multiple vanes extends in one direction (D4) that is inclined with respect to the second direction and perpendicular to the first direction. The plurality of prism sections include a first prism section (221) located furthest to the one side in the second direction among the plurality of prism sections, and a second prism section (222) adjacent to the first prism section. The aforementioned end cover portion extends so as to cover the tip (22c) of the first prism portion, The optical apparatus according to claim 3, wherein the spherical center (Cfs) is located at the same position in the second direction as the furthest point (Pz) on the curved surface portion of the corner extension outer surface, and the largest virtual sphere (Fs) is provided on the one side of the corner extension outer surface in the first direction, passes through the furthest point, does not intersect with any of the plurality of vanes, and touches two adjacent vanes (43, 44) among the plurality of vanes, respectively, and the diameter of the largest virtual sphere (Fs) is Dmx, the diameter of the virtual sphere is Dsp, and the pitch between the first prism portion and the second prism portion in the second direction is Pe, such that the relationship "Dmx < Dsp + Pe / 2" holds true.

13. The aforementioned one or more fins refer to multiple fins arranged at intervals from one another. Each of the aforementioned multiple vanes extends in one direction (D4) that is inclined with respect to the second direction and perpendicular to the first direction. The plurality of prism sections includes a terminal prism section (222) that is located furthest to the one side in the second direction among the plurality of prism sections, If the diameter of the largest virtual sphere (Fs) is Dmx, the diameter of the virtual sphere is Dsp, and the distance between the furthest point (Pz) in the second direction and the tip (22c) of the terminal prism portion in the second direction is P1e, then the relationship "Dmx < Dsp + P1e / 2" holds true. The optical apparatus according to claim 6, wherein the farthest point is located at the same position as the tip of the terminal prism portion in the first direction, or at a position on one side of the first direction relative to the tip of the terminal prism portion.

14. The optical device according to claim 1 or 2, wherein the radius of curvature of the curved portion of the outer surface extending from the corner is 3.2 mm or more.

15. The optical apparatus according to claim 1 or 2, wherein the diameter (Dsp) of the virtual spherical shape is 165 mm.

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