Light guide

Abstract

The light guide (1) guides light input from a light input surface (10a) to a light output surface (20a) different from the light input surface, and outputs the light from the light output surface. The light guide (1) is provided with a light input part (10) having the light input surface for inputting light in the Z-axis direction; a light guide section (20) that is provided on the light-emitting surface side and that guides light in the Y-axis direction and outputs the light from the light-emitting surface; the continuous parts (31) are respectively arranged at the boundaries of the light incident part and the light guide part and enable the light incident part and the light guide part to be continuous; and the non-continuous parts (32) separate the light incident part and the light guide part. As a result, light input to the light input section in the Z-axis direction via the light input surface enters the light guide section via a continuous section that is provided at the boundary between the light input section and the light guide section and that continues the light input section and the light guide section, and is guided in the Y-axis direction inside the light guide section, so that light collected by the light input section can be output from the light output surface without leakage.

Description

Technical Field

[0001] The present invention relates to a light guide. Background Art

[0002] In order to curb the emission of carbon dioxide, the utilization of renewable energy such as solar power generation is being promoted. However, the conversion efficiency of light to electricity is not necessarily high. Therefore, a solar lighting system has been developed that improves efficiency by collecting sunlight and guiding it to another place, and then using it for lighting without converting it into electrical energy. For example, Patent Document 1 discloses a lighting device, which includes: a plurality of focusing elements, each of which has a light guide extending parallel to the incident surface of light input, a focusing part connected to the light guide part and gradually tapering and having a reflective surface at the end; a plurality of coupled waveguides for guiding light entering from a plurality of focusing elements through the reflective surface respectively; and an integrated waveguide for connecting to a plurality of coupled waveguides to collect light. The focusing element in this lighting device collects a large amount of light, but when the collected light is reversed, it leaks from the focusing element, so the focusing efficiency is not necessarily high.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2008-251468 Summary of the invention

[0004] (Item 1)

[0005] It may be a light guide for guiding light input from a light incident surface to a light exit surface different from the light incident surface and outputting light from the light exit surface.

[0006] The light guide may include a light incident portion having the light incident surface provided to input the light from the first direction.

[0007] The light guide may include a light guide portion disposed on the light output surface side relative to the light input portion, and configured to guide the light in a second direction intersecting the first direction and output the light from the light output surface.

[0008] The light guide may include a continuous portion and a discontinuous portion, which are respectively arranged at the boundaries between the light incident portion and the light guiding portion, the continuous portion is configured to make the light incident portion and the light guiding portion continuous, and the discontinuous portion is configured to separate the light incident portion and the light guiding portion.

[0009] (Item 2)

[0010] A plurality of the continuous portion and the discontinuous portion may be provided at the boundary between the light incident portion and the light guiding portion, respectively, and the plurality of the continuous portions and the plurality of the discontinuous portions may be alternately arranged along the second direction.

[0011] (Item 3)

[0012] The continuous portion and the discontinuous portion may be configured such that a length of the continuous portion in the second direction is smaller than a length of the discontinuous portion.

[0013] (Item 4)

[0014] The light incident portion may include a reflective surface provided to reflect the light input from the light incident surface toward the continuous portion.

[0015] (Item 5)

[0016] The reflective surface may be formed to reflect the light input from a direction orthogonal to the light incident surface toward the continuous portion.

[0017] (Item 6)

[0018] The reflecting surface may be formed by bending or curving in a cross section including the first direction and the second direction.

[0019] (Item 7)

[0020] Another reflecting surface may be further provided, the other reflecting surface being arranged opposite to the reflecting surface and reflecting the light input from the light incident surface toward the continuous portion.

[0021] (Item 8)

[0022] The light incident portion may extend in the second direction.

[0023] The light incident surface may be formed in a planar shape having a width in a third direction respectively intersecting the first direction and the second direction.

[0024] (Item 9)

[0025] The light guide portion may be formed to extend in the second direction.

[0026] (Item 10)

[0027] In the first direction, an end portion of the light guide portion on the opposite side to the light incident portion may be formed in a planar shape.

[0028] (Item 11)

[0029] The continuous portion may be formed to extend in the third direction.

[0030] (Item 12)

[0031] The continuation may be configured such that the third direction is substantially parallel to a plane containing a movement trajectory of the sun.

[0032] (Item 13)

[0033] The light incident portion and the light guide portion may be respectively formed as separate bodies, and may be formed by being joined to each other via the continuous portion.

[0034] (Item 14)

[0035] The light incident portion and the light guide portion may be joined by welding.

[0036] (Item 15)

[0037] The light incident portion and the light guide portion may be formed of the same material.

[0038] (Item 16)

[0039] The discontinuous portion may include a first discontinuous portion in which a separation distance between the light incident portion and the light guiding portion is constant along the second direction, and a second discontinuous portion in which a separation distance between the light incident portion and the light guiding portion is not constant along the second direction.

[0040] (Item 17)

[0041] The light incident portion may include a reflective surface provided to reflect the light input from the light incident surface toward the continuous portion.

[0042] The opposite surface of the reflecting surface toward the light guiding portion may be provided as an end portion of the second discontinuous portion on the light incident portion side.

[0043] (Item 18)

[0044] The light guide may further include a light focusing portion that is disposed on the opposite side of the light incident portion with respect to the light guide portion in the first direction and is provided to input the light that has passed through the light guide portion.

[0045] (Item 19)

[0046] The light guide may further include other continuous portions and other discontinuous portions, which are respectively arranged at other boundaries of the light guiding portion and the light focusing portion, the other continuous portions are arranged to make the light guiding portion and the light focusing portion continuous, and the other discontinuous portions are arranged to separate the light guiding portion and the light focusing portion.

[0047] (Item 20)

[0048] The light-collecting portion may include a light-returning portion that returns leakage light leaking from the light-guiding portion to the light-guiding portion.

[0049] (Item 21)

[0050] The light returning portion may include a reflecting surface for reflecting the leaked light toward the other continuous portion.

[0051] (Item 22)

[0052] The light-returning portion may include a refractive surface configured to refract the leaked light reflected by the reflective surface toward the other continuous portion.

[0053] (Item 23)

[0054] The reflection surface of the light returning portion may be arranged to be offset in the second direction with respect to the reflection surface of the light incident portion.

[0055] (Item 24)

[0056] The other continuous portion may be shorter than the other discontinuous portion in the second direction, and the center of the other continuous portion may be configured to be offset relative to the reflection surface of the light returning portion and the reflection surface of the light incident portion in the second direction.

[0057] (Item 25)

[0058] When viewed in the first direction, the continuous portion and at least a portion of the other non-continuous portion may be disposed to overlap each other.

[0059] (Item 26)

[0060] The other discontinuous portions may be provided such that a separation distance between the light guiding portion and the light collecting portion is constant along the second direction.

[0061] (Item 27)

[0062] The light incident portion may include a reflective surface configured to reflect the light input from the light incident surface, and the reflective surface may be formed in a straight line shape in a cross section including the first direction and the second direction.

[0063] (Item 28)

[0064] The discontinuous portion may be provided so that an end portion of the discontinuous portion on the light guide portion side extends obliquely with respect to the second direction.

[0065] In addition, the above summary of the invention does not list all the features of the present invention. In addition, a sub-combination of these feature groups may also be an invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1A The structure of the light guide according to the first embodiment is shown.

[0067] Figure 1B The structures of the light incident portion and the boundary portion are shown.

[0068] Figure 1C The light focusing principle based on the reflective surface of the light focusing element is shown.

[0069] Figure 2 The diagram shows light input to the light guide body, which is focused by the light incident portion, light guided by the light guiding portion, and light leaked from the light incident portion.

[0070] Figure 3A The configuration of the light guide and the incident angle of light are shown.

[0071] Figure 3B Shown relative to Figure 3A Light extraction efficiency at the incident angles shown.

[0072] Figure 4 A first manufacturing method flow of a light guide is shown.

[0073] Figure 5A In the main view (relative to Figure 5B The state of the inside of the mold after the mold and insert setting process in the first manufacturing method is shown in the cross section along the reference line AA in FIG.

[0074] Figure 5B In the side view (relative to Figure 5A The state of the inside of the mold after the mold and insert setting step in the first manufacturing method is shown in the cross section along the reference line BB in FIG.

[0075] Figure 5C The flow of resin in the molding step in the first manufacturing method is shown.

[0076] Figure 5D The state of the inserted part being pulled out in the insert part pulling out step in the first manufacturing method is shown.

[0077] Figure 6 A second manufacturing method flow of the light guide is shown.

[0078] Fig. 7A The front view shows the state of the inside of the mold after the first mold setting step in the second manufacturing method.

[0079] Figure 7B The structure of the light incident portion molded by the light incident portion molding step using the first mold in the second manufacturing method is shown.

[0080] Figure 7C The bottom surface of the light incident portion and the structure of the continuous portion are shown.

[0081] Fig.7D The front view shows the state of the interior of the mold after the second mold and the insert setting step in the second manufacturing method.

[0082] Fig. 7E The perspective view shows the state of the interior of the second mold after the second mold and insert setting step in the second manufacturing method.

[0083] Figure 8 A third method flow for manufacturing a light guide is shown.

[0084] Fig.9A The structure of the light incident portion formed in the light incident portion forming step in the third manufacturing method is shown.

[0085] Fig. 9B The structure of the light guide portion molded in the light guide portion molding step in the third manufacturing method is shown.

[0086] Fig. 9C The following is a diagram showing a state in which the light incident portion and the light guide portion are welded by the welding step in the third manufacturing method.

[0087] Fig.9D The state of the boundary (continuous portion and discontinuous portion) between the light incident portion and the light guide portion welded by the welding step in the third manufacturing method is shown.

[0088] Fig.10 The structure of the light guide according to the first modification example is shown.

[0089] Fig.11 The following illustrates light input to the light guide body according to the first modification example, which is focused by the light incident portion, light guided by the light guiding portion, and leaked light from the light incident portion.

[0090] Fig. 12A The structure of a light guide according to the second embodiment is shown.

[0091] Fig. 12B The structures of the light-reflecting portion and the boundary portion are shown.

[0092] Fig.13 The light-reflecting principle based on the light-reflecting part is shown.

[0093] Fig.14 The light guiding principle by the light guiding part is shown.

[0094] Fig.15 A fourth method flow for manufacturing a light guide is shown.

[0095] Fig.16A The structure of the light incident portion formed in the light incident portion forming step in the fourth manufacturing method is shown.

[0096] Fig. 16B The structure of the light guide portion molded in the light guide portion molding step in the fourth manufacturing method is shown.

[0097] Fig. 16C The structure of the light returning portion formed in the light returning portion forming step in the fourth manufacturing method is shown.

[0098] Fig.16DThe fourth manufacturing method shows a state where the light incident portion, the light guide portion, and the light return portion are welded by the welding step.

[0099] Fig.17 The structure of a light guide according to a second modification example is shown.

[0100] Fig.18 The structure of a light guide according to a third modification example is shown.

[0101] Fig.19A The structure of a light guide according to the third embodiment is shown.

[0102] Fig.19B The structures of the light incident portion and the boundary portion are shown.

[0103] Fig. 20 The light input into the light guide is shown as being focused by the light incident portion and guided by the light guiding portion.

[0104] Fig.21 A light guide assembly according to a third embodiment is shown.

[0105] Fig. 22 The principles of light focusing by the light incident portion and light guiding by the light guiding portion of the light input to the light guide assembly are shown.

[0106] Fig.23 The structure and focusing principle of the light guide assembly according to the modified example are shown. DETAILED DESCRIPTION

[0107] Hereinafter, the present invention will be described by way of the embodiments of the invention, but the following embodiments do not limit the claimed invention. In addition, all combinations of the features described in the embodiments are not necessarily essential to the solution of the present invention.

[0108] First embodiment

[0109] Figure 1A and Figure 1B The overall structure of the light guide 1 involved in the first embodiment, and the structure of the light input portion 10 and the boundary portion 30 between the light input portion 10 and the light guide portion 20 are shown respectively. The light guide 1 is an optical device for efficiently collecting light input from the light input surface 10a, and guiding the collected light to the light output surface 20a different from the light input surface 10a without leakage or with little leakage to output, and includes the light input portion 10, the light guide portion 20, and the boundary portion 30. In addition, the light guide 1 as a whole has a roughly plate shape that extends in a two-dimensional direction with the X-axis direction as a short side and the Y-axis direction as a long side, and has a thickness in the Z-axis direction.

[0110] The light input portion 10 is an optical component that focuses light input in an input direction (in the present embodiment, in the -Z direction) via a light input surface 10a, and has a plurality of focusing elements 11. The plurality of focusing elements 11 are columnar components extending in the X-axis direction, and have an inverted substantially isosceles trapezoidal cross section having a maximum width P in the Y-axis direction and a height d in the Z-axis direction, and are in contact with each other on the +Z side of the Y side (i.e., the +Y side and the -Y side), and are separated from each other on the -Z side and arranged in parallel in the Y-axis direction. In the present embodiment, the plurality of focusing elements 11 are coupled to each other and integrally formed (however, in order to facilitate the description of the structure and function of the light input portion 10, it will be assumed that the light input portion 10 includes a plurality of focusing elements 11 for explanation). Thus, the light input portion 10 extends in the Y-axis direction, and the +Z surfaces of the plurality of focusing elements 11 are coupled to each other to form a planar light input surface 10a having a width in the X-axis direction. In this way, the light input surface 10a is configured to input light from the +Z side. Furthermore, two adjacent light concentrating elements 11 form a hollow space (referred to simply as a space) 30s having a substantially isosceles triangle cross section and extending in the X-axis direction therebetween.

[0111] In addition, the plurality of light concentrating elements 11 may be arranged to be separated from each other in the Y-axis direction. In this case, each of the +Z surfaces of the plurality of light concentrating elements 11 serves as an independent light incident surface.

[0112] The focusing element 11 can be formed using a resin with a high refractive index, such as acrylic resin (refractive index 1.49), polycarbonate resin (refractive index 1.58), or glass (for example, a refractive index of 1.51 to 1.53 relative to BK7). Thus, the boundary between the focusing element 11 and the space 30s, that is, the ±Y side surfaces of the focusing element 11, serve as reflection surfaces 12 and 13 for reflecting light input into the focusing element 11 via the light incident surface 10a. When light enters the ±Y side surfaces from the inside of the focusing element 11 at an angle greater than the critical angle, the light is totally reflected. The critical angle is approximately 42 degrees with respect to acrylic resin, approximately 41 degrees with respect to polycarbonate resin, and approximately 42 degrees with respect to glass. Therefore, the ±Y side surfaces of the focusing element 11 are formed so that their normal lines form an angle greater than the critical angle with respect to the input direction of the light (the Z-axis direction in this embodiment).

[0113] The reflecting surfaces 12 and 13 are arranged to face each other, and reflect and focus the light input from the light incident surface 10a toward the continuous portion 31. Here, in order to increase the reflectivity, the reflecting surfaces 12 and 13, i.e., the ±Y side surfaces of the focusing element 11, may be mirror-finished. In addition, a reflective film may be provided using metal or the like.

[0114] The light guide portion 20 is an optical component that is arranged on the light output surface 20a side, i.e., the -Z side, relative to the light entrance surface 10a of the light entrance portion 10, and guides light in the +Y direction and / or -Y direction and outputs light from the light output surface 20a. The light guide portion 20 is formed in a plate shape extending in the Y-axis direction. Here, the width of the light guide portion 20 in the X-axis direction is equal to (or may be greater than) the width of the light entrance portion 10, the length in the Y-axis direction is greater than (or may be equal to) the length of the light entrance portion 10, and the thickness in the Z-axis direction is greater than (can be arbitrarily set) the thickness of the light entrance portion 10. The +Y side surface and / or the -Y side surface of the light guide portion 20 form a light output surface 20a for outputting light, and the +Z end and the -Z end are formed in a planar shape, thereby serving as a reflection surface for reflecting the light guided into the light guide portion 20 toward the inside.

[0115] The light guide 20 may be formed of the same material as the light focusing element 11. In order to increase the reflectivity, the +Z end and -Z end of the light guide 20 may be mirror-finished. In addition, a reflective film may be provided using metal or the like.

[0116] In addition, on the light guiding path of light from the light incident surface 10a of the light incident portion 10 to the light emitting surface 20a of the light guiding portion 20, the light incident portion 10 is arranged on the side closer to the light incident surface 10a than the light guiding portion 20, and the light guiding portion 20 is arranged on the side closer to the light emitting surface 20a than the light incident portion 10.

[0117] The boundary portion 30 is a portion located at the boundary between the light incident portion 10 and the light guide portion 20 , and includes a continuous portion 31 and a discontinuous portion 32 .

[0118] The continuous portion 31 is provided so that the light incident portion 10 and the light guide portion 20 are physically continuous, and guides the light reflected by the reflection surfaces 12 and 13 of the light incident portion 10 into the light guide portion 20. The continuous portion 31 is formed in a plate shape extending in the X-axis direction, has a cross section (the minimum width in the Y-axis direction, i.e., the opening width A) in which the +Z end portion is extended in the Y-axis direction relative to the -Z end portion, and is arranged at the center in the Y-axis direction on the -Z plane of the light focusing element 11 so as to be able to guide light from a wide angle range. In addition, the continuous portion 31 can be formed of the same material as the light focusing element 11.

[0119] The discontinuous portion 32 is a portion that is provided to separate the light incident portion 10 and the light guide portion 20 from each other, and is disposed adjacent to the ±Y sides of the continuous portion 31, respectively. The discontinuous portion 32 includes a first discontinuous portion 32a in which the separation distance between the light incident portion 10 and the light guide portion 20 is constant along the Y-axis direction, and a second discontinuous portion 32b in which the separation distance between the light incident portion 10 and the light guide portion 20 is not constant (not constant but varies) along the Y-axis direction. In this example, the first discontinuous portion 32a is provided at the ±Y ends of the discontinuous portion 32, and the second discontinuous portion 32b is provided between the two first discontinuous portions 32a. Here, the back side of the reflective surfaces 12, 13 (i.e., the opposite side facing the light guide portion 20) is provided as the end portion on the light incident portion 10 side constituting the second discontinuous portion 32b. Through the second non-continuous portion 32b and the first non-continuous portion 32a, the light guiding portion 20 is separated from the light incident portion 10 (the reflecting surfaces 12 and 13 on the -Z plane or the ±Y side surfaces), and a space 30s and a space 30t extending from the -Z end portions thereof along the ±Y directions are formed therebetween, whereby the +Z end surface of the light guiding portion 20 is used as a reflecting surface for reflecting light from the light guiding portion 20 toward the light incident portion 10 in the -Z direction.

[0120] In the present embodiment, a plurality of continuous portions 31 and discontinuous portions 32 are respectively provided at the boundaries between the light incident portion 10 and the light guide portion 20, and the plurality of continuous portions 31 and the plurality of discontinuous portions 32 are alternately provided along the Y-axis direction. Here, the continuous portions 31 of the opening width A are periodically arranged at a pitch P in the Y-axis direction, and are configured such that the length of the continuous portion 31 is smaller than the length of the discontinuous portion 32, that is, the aperture ratio A / P is reduced. Thus, it is possible to suppress the light guided in the light guide portion 20 from being reflected at the +Z end face where the discontinuous portion 32 is located and returning to the light guide portion 20, and leaking to the light incident portion 10 through the continuous portion 31, and then leaking to the outside of the light guide 1.

[0121] like Figure 1B As shown, the reflection surfaces 12 and 13 of the light incident portion 10 reflect light input from the light incident surface 10a toward the continuous portion 31. In particular, the reflection surfaces 12 and 13 are formed to reflect light input from a direction orthogonal to the light incident surface 10a (in this embodiment, the Z-axis direction) toward the continuous portion 31.

[0122] Figure 1CThe focusing principle based on the reflecting surfaces 12 and 13 of the focusing element 11 is shown. The reflecting surfaces 12 and 13 are bent or curved in the YZ cross section, and are formed to be inclined more greatly with respect to the input direction of light (Z-axis direction) on the -Z side relative to the +Z side. In addition, the reflecting surfaces 12 and 13 can also be bent continuously from the +Z side to the -Z side. Here, the reflecting surfaces 12 and 13 form a part of a parabola 19 on the YZ cross section, and the parabola 19 is defined by a directrix 19a parallel to the Y axis located on the -Z side of the continuous portion 31 and a focus 19b located at the center of the continuous portion 31. As a result, light input from the light incident surface 10a along the -Z direction and entering the +Z side of the reflecting surfaces 12 and 13 is reflected at a relatively large incident angle (the angle formed by the normal line of the reflecting surface and the input direction), light entering the center is reflected at a moderate incident angle, and light entering the -Z side is reflected at a relatively small incident angle and is focused toward the center of the continuous portion 31.

[0123] In addition, the reflecting surfaces 12 and 13 may also be bent in a manner that a plurality of straight lines are continuous. Here, the reflecting surfaces 12, 13 approximately form a portion of the parabola 19 in the YZ cross section. In this case, the length and inclination of each straight line can be determined so that the parallel light reflected from the straight surface including a straight line propagates over the entire range or a larger range in the Y-axis direction of the continuous portion 31 and passes through the continuous portion 31. Thus, the light entering the +Z side of the reflecting surfaces 12, 13 is reflected at a relatively large incident angle (the angle formed by the normal of the reflecting surface and the input direction), the light entering the center is reflected at a moderate incident angle, and the light entering the -Z side is reflected at a relatively small incident angle and is focused toward the continuous portion 31.

[0124] Figure 2 The light input to the light guide body 1 is shown as light focusing by the light incident portion 10, light guiding by the light guiding portion 20, and light leakage from the light incident portion 10. As described above, since the width A of the continuous portion 31 in the Y-axis direction is small, the light focused on the continuous portion 31 and entering the light guiding portion 20 via the continuous portion 31 is diffused in the light guiding portion 20. The light reflected on the +Z side of the reflection surface 13 and entering the light guiding portion 20 via the continuous portion 31 enters the ±Z end faces of the light guiding portion 20 at a relatively large inclination, and is guided in the +Y direction while being reflected relatively many times in the light guiding portion 20. The light reflected on the -Z side of the reflection surface 13 and entering the light guiding portion 20 via the continuous portion 31 enters the ±Z end faces of the light guiding portion 20 at a small inclination, and is guided in the +Y direction while being reflected relatively few times in the light guiding portion 20. Therefore, the light entering the reflection surface 13 is reflected on the ±Z end faces while being diffused in a wide angle range as a whole, and is guided in the +Y direction. Here, light may return to the light incident portion 10 via a continuous portion 31 different from the continuous portion 31 through which light passes when entering the light guide portion 20, and leak to the outside of the light guide body 1. However, since the aperture ratio A / P is small, light leakage is suppressed.

[0125] Figure 3A The configuration of the light guide 1 and the incident angle of light are shown. The light guide 1 is configured so that the extension direction of the continuous portion 31 (i.e., the X-axis direction) is approximately parallel to the plane (movement trajectory plane) 99 containing the movement trajectory of the sun, and the normal direction of the light incident surface 10a is approximately parallel to the movement trajectory plane 99, that is, the focusing element 11 is approximately parallel to the movement trajectory plane 99. The incident angle of light is determined based on the normal direction of the light incident surface 10a. Here, the movement trajectory plane 99 of the sun is a plane formed by the circular motion trajectory of the sun.

[0126] Figure 3B Shows relative to Figure 3A The light extraction efficiency of the light guide 1 at the incident angle shown. The extraction efficiency can be analyzed by means of a so-called light simulation and is calculated by dividing the amount of light output from the light exit surface 20a by the amount of light input to the light entrance surface 10a. In the case where the incident angle is zero (vertically incident on the light entrance surface 10a), most of the light entering the light entrance portion 10 via the light entrance surface 10a is guided within the light guide portion 20 and output from the light exit surface 20a. However, if the incident angle exceeds 20 degrees, the extraction efficiency gradually decreases and is almost zero at an incident angle of 80 degrees. It can be seen that a high extraction efficiency can be obtained at least in the range of incident angles of 0 to 40 degrees, i.e., over a longer period of time during the daylight hours.

[0127] In addition, the inclination of the light guide 1 is adjusted according to the sun's zenith angle. For example, the inclination of the light guide 1 can be adjusted multiple times a year so that the extension direction of the continuous portion 31 and the normal direction of the light incident surface 10a are basically parallel to the sun's movement trajectory plane 99.

[0128] Figure 4 The first manufacturing method flow S100 of the light guide 1 is shown. In this embodiment, as an example, acrylic resin is used as a molding material of the light guide 1. That is, the light incident portion 10 and the light guide portion 20 are formed of the same material.

[0129] In step S101 , molds 51 , 52 and a plurality of inserts 53 are provided. Figure 5A and Figure 5B In the main view (about Figure 5B Baseline AA in the image) and side view (about Figure 5AThe state inside the molds 51 and 52 is shown in the reference line BB in FIG. 1 . The mold 51 is a metal mold for forming the light incident portion 10, and includes an internal space having a size and shape capable of accommodating the light incident portion 10 and a plurality of inserts 53. The mold 52 is a metal mold for forming the light guide portion 20, and includes an internal space having a size and shape capable of accommodating the light guide portion 20. The plurality of inserts 53 are metal molds for forming spaces 30s and 30t in the light incident portion 10 (between the plurality of light focusing elements 11), and are solid cylindrical bodies having a cross-sectional shape including a substantially isosceles triangle and convex pieces extending to the left and right from the base thereof.

[0130] The mold 52 is set with its internal space facing the +Z direction, and the plurality of inserts 53 are arranged on the mold 52 along the Y-axis direction so as to span the internal space of the mold 52 in the X-axis direction, and the mold 51 is set with its internal space facing the -Z direction to cover the mold 52. Thus, an internal space 50s separated vertically except for a part is formed between the molds 51 and 52 by the plurality of inserts 53.

[0131] In step S102 , acrylic resin is injected into the molds 51 , 52 to mold the light guide 1 . Figure 5C The flow of resin in the molds 51 and 52 is shown. The resin is injected into the lower part of the inner space 50s through the through hole (not shown) of the mold 52, fills in the direction of the black arrow and fills upward through the gaps of the plurality of inserts 53. After the resin cools down after a certain period of time, the next step is performed.

[0132] In step S103, the mold 51 is pulled in the +Z direction to open the mold. Figure 5D As shown, in a state where the light guide portion 20 is embedded in the inner space of the mold 52 , the light incident portion 10 is exposed on the mold 52 .

[0133] In step S104 , a plurality of insert parts 53 are pulled out. Figure 5D The state of pulling out the multiple inserts 53 from the light guide 1 is shown. The multiple inserts 53 are pulled out in the direction of the white arrow (+X direction). In addition, the multiple inserts 53 can also be formed into a tapered shape with the +X end being thinner than the -X end, so as to be easily pulled out from the light guide 1.

[0134] In step S105, the light guide 1 is removed from the mold 52. Thus, Figure 1A The light guide 1 is shown.

[0135] In step S106, the molds 51, 52 and the plurality of inserts 53 are cleaned. Thus, the process ends. By repeating steps S101 to S106, a plurality of light guides 1 can be manufactured.

[0136] Figure 6The second manufacturing method flow S200 of the light guide 1 is shown. In this embodiment, as an example, acrylic resin is used as a molding material of the light guide 1. That is, the light incident portion 10 and the light guide portion 20 are formed of the same material.

[0137] In step S201 , the molds 61 and 62 are set. Fig. 7A The state inside the molds 61 and 62 is shown in the front view (viewed in the X-axis direction). The molds 61 and 62 are a pair of metal molds for forming the light incident portion 10. The mold 61 includes an internal space having a size and shape capable of accommodating the light incident portion 10. The mold 62 has a plurality of protruding edges 62a protruding from the upper surface in the +Z direction and arranged in the Y-axis direction. The plurality of protruding edges 62a are a structure for forming spaces 30s, 30t in the light incident portion 10 (between the plurality of focusing elements 11), and are formed to have a cross-sectional shape including a substantially isosceles triangle and protrusions extending to the left and right from the base thereof, respectively, and extending in the X-axis direction.

[0138] The mold 62 has a plurality of protruding sides 62a facing the +Z direction, and the mold 61 is covered with the mold 62 so that its internal space accommodates the protruding sides 62a facing the -Z direction. Thus, an internal space 61s is formed between the molds 61 and 62.

[0139] In step S202 , acrylic resin is injected into the molds 61 and 62 to mold the light incident portion 10 . Figure 7B and Figure 7C The overall structure of the molded light incident portion 10 and the structure on the -Z side are shown respectively. As described above, the light incident portion 10 is integrally molded in such a manner that a plurality of light focusing elements 11 are arranged in the Y-axis direction, and a space 30s is included between the light focusing elements 11 adjacent to each other. At the center of the Y-axis direction on the -Z plane of each light focusing element 11, a continuous portion 31 is formed so as to protrude from the -Z plane of the light focusing element 11 in the -Z direction and extend in the X-axis direction. That is, in this example, the continuous portion 31 is integrally molded with the light incident portion 10. The detailed structure of the continuous portion 31 is as described above.

[0140] In step S203 , the mold 62 is opened from the mold 61 . In this state, the light incident portion 10 is accommodated in the mold 61 .

[0141] In step S204 , the molds 61 , 63 and a plurality of inserts 65 are provided. Fig.7D and Fig. 7E The internal states of the molds 61 and 63 are shown in the front view (viewed in the X-axis direction) and the oblique view, respectively. The mold 63 is constructed in the same manner as the above-mentioned mold 52. The plurality of inserts 65 are constructed in the same manner as the above-mentioned insert 53. However, the length thereof is equal to the width of the light incident portion 10 in the X-axis direction.

[0142] The mold 61 containing the light incident portion 10 is turned upside down, and the inserts 65 are respectively inserted into the multiple spaces 30s of the light incident portion 10, and the mold 63 is made to face the internal space in the -Z direction to cover the mold 61. Thus, the light incident portion 10 with the multiple inserts 65 respectively embedded in the space 30s is accommodated in the internal space of the mold 61, and an internal space 63s is formed between the mold 61 and the mold 63.

[0143] In step S205, acrylic resin is injected into the molds 61 and 63, and the light guide 1 is molded by casting. The resin is injected into the internal space 63s through the through hole (not shown) of the mold 63, and fills the +Z side of the light incident portion 10. After the resin cools down for a certain period of time, the resin forms the light guide portion 20 and passes through the continuous portion 31 (refer to FIG. Figure 7C ) is integrated with the light incident portion 10.

[0144] In step S206, the light guide 1 is pulled out from the molds 61 and 63, and the plurality of inserts 65 are pulled out from the light guide 1. In addition, the plurality of inserts 53 may also be formed into a tapered shape with the +X end being thinner than the -X end, so as to be easily pulled out from the light guide 1. Figure 1A The light guide 1 is shown.

[0145] In step S207, the molds 61, 62, 63 and the plurality of inserts 65 are cleaned. Thus, the process ends. By repeating steps S201 to S207, a plurality of light guides 1 can be manufactured.

[0146] Figure 8 The third manufacturing method flow S300 of the light guide 1 is shown. In this embodiment, as an example, acrylic resin is used as a molding material of the light guide 1. That is, the light incident portion 10 and the light guide portion 20 are formed of the same material.

[0147] In step S302, the light incident portion 10 is formed. The light incident portion 10 may be formed through the above steps S201 to S203. Fig.9A The structure of the molded light incident portion 10 is shown. The light incident portion 10 is formed as a body separate from the light guide portion 20.

[0148] In step S304, the light guide portion 20 is molded. Details of the molding are omitted. Fig. 9B The structure of the molded light guide portion 20 is shown. The light guide portion 20 is formed as a body separated from the light incident portion 10.

[0149] In step S306, the light incident portion 10 and the light guide portion 20 are welded to form the light guide body 1. Fig. 9C As shown, the light incident portion 10 is disposed on the +Z end surface of the light guide portion 20 with one end surface where the space 30s is formed facing the -Z side. Fig.9DAs shown, the continuous portion 31 integrally formed on the -Z surface of the light incident portion 10 abuts against the +Z end surface of the light guide portion 20. In this state, the light incident portion 10 and / or the light guide portion 20 are welded by applying ultrasonic vibration to them. Thus, the light incident portion 10 and the light guide portion 20 are joined to each other via the continuous portion 31, thereby forming the light guide body 1.

[0150] In addition, the light incident portion 10 and the light guide portion 20 may be bonded together by using, for example, a solvent, without being limited to welding. In addition, the light guide body 1 may be molded using a 3D printer.

[0151] The light guide 1 involved in the first embodiment is an optical device that guides light input from a light input surface 10a to a light output surface 20a different from the light input surface 10a and outputs light from the light output surface 20a, and comprises: a light input portion 10 having a light input surface 10a for inputting light in the Z-axis direction; a light guide portion 20 that is arranged on the side of the light output surface 20a and guides light in the Y-axis direction and outputs light from the light output surface 20a; a continuous portion 31 that is respectively arranged on the boundary between the light input portion 10 and the light guide portion 20 and connects the light input portion 10 and the light guide portion 20, and a non-continuous portion 32 that separates the light input portion 10 and the light guide portion 20. Thus, by inputting the light input to the light input portion 10 in the Z-axis direction via the light input surface 10a into the light guide portion 20 via the continuous portion 31 provided on the boundary between the light input portion 10 and the light guide portion 20 so as to make them continuous, and guiding them along the Y-axis direction inside the light guide portion 20, the light focused by the light input portion 10 can be output from the light output surface 20a with almost no leakage. In addition, by structurally separating the light guide 1 into two parts, the light input portion 10 for focusing light and the light guide portion 20 for guiding light, and making the light input portion 10 continuous with the light guide portion 20 via the continuous portion 31 having a width smaller than the non-continuous portion 32, it is possible to suppress the leakage of light from the light guide portion 20 to the light input portion 10 via the continuous portion 31.

[0152] Furthermore, the light guide 1 according to the first embodiment is provided with a pair of reflecting surfaces 12 and 13 facing each other on the ±Y side surfaces of one light converging element 11 , but the present invention is not limited thereto, and the reflecting surface may be provided on only one of the ±Y side surfaces.

[0153] Alternatively, the light output from the light output surface 20a of the light guide 1 may be input to another light guide (optical fiber, etc.) different from the light guide 1 and output (emitted) at the other end of the other light guide.

[0154] Fig.10 The structure of the light guide 1d according to the first modification example, in particular, the detailed structure of the light incident portion 10d and the boundary portion 30d between the light incident portion 10d and the light guide portion 20d is shown. The light guide 1d includes the light incident portion 10d, the light guide portion 20d, and the boundary portion 30d.

[0155] Like the above-mentioned light incident portion 10, the light incident portion 10d is an optical component that focuses light input in the input direction (in this case, the -Z direction) via the light incident surface 10a, and has a plurality of focusing elements 11d. The plurality of focusing elements 11d are columnar components extending in the X-axis direction, and the columnar components have a substantially parallelogram-shaped cross-section with a width P in the Y-axis direction and a height d in the Z-axis direction, with the +Z ends in contact with each other, and are arranged in the Y-axis direction separated from each other on the ±Y inclined surfaces. In this example, the plurality of focusing elements 11d are coupled to each other and integrally formed. Thus, the light incident portion 10d extends in the XY direction, and the +Z surfaces of the plurality of focusing elements 11d are coupled to each other to form a planar light incident surface 10a extending in the XY direction. In addition, two adjacent focusing elements 11d form a space 30s extending in the +Y and -Z directions and in the X-axis direction between each other.

[0156] In addition, the plurality of light concentrating elements 11d may be arranged to be separated from each other in the Y-axis direction. In this case, each of the +Z surfaces of the plurality of light concentrating elements 11d serves as an independent light incident surface.

[0157] As described above, the focusing element 11d can be formed using a resin or glass having a high refractive index. Thus, the boundary between the focusing element 11d and the space 30s, i.e., the -Y slope of the focusing element 11, serves as a reflection surface 14 for reflecting the light input into the focusing element 11d via the light incident surface 10a. When light enters the -Y side surface from the inside of the focusing element 11d at an angle greater than the critical angle, the light is totally reflected. Therefore, the -Y side surface of the focusing element 11d is formed so that its normal forms an angle greater than the critical angle with respect to the input direction of the light (in this case, the Z-axis direction).

[0158] The reflective surface 14 reflects the light input from the light incident surface 10a to focus the light toward the continuous portion 31. Here, in order to increase the reflectivity, the reflective surface 14, that is, the -Y side surface of the focusing element 11d may be mirror-finished. In addition, a reflective film may be provided using metal or the like.

[0159] The light guide portion 20 d is configured in the same manner as the above-described light guide portion 20 .

[0160] The boundary portion 30 d is a portion located at the boundary between the light incident portion 10 d and the light guide portion 20 d , and includes a continuous portion 31 and a discontinuous portion 32 .

[0161] In the continuous portion 31, the light incident portion 10d and the light guide portion 20d are physically continuous, and the light reflected by the reflection surface 14 of the light incident portion 10d is guided to the light guide portion 20d. The continuous portion 31 is formed in a plate shape having a width in the Y-axis direction, that is, an opening width A and extending in the X-axis direction, and is provided on the +Y side on the -Z plane of the light focusing element 11. In addition, the continuous portion 31 can be formed of the same material as the light focusing element 11.

[0162] The discontinuous portion 32 is a portion provided to separate the light incident portion 10d and the light guide portion 20d from each other, and is provided adjacent to the -Y side of the continuous portion 31. The light guide portion 20d is separated from the light incident portion 10d (-Z surface) by the discontinuous portion 32, and a space 30t extending from the -Z end of the space 30s in the +Y direction is formed therebetween, so that the +Z end surface of the light guide portion 20d serves as a reflection surface that reflects light from the inside of the light guide portion 20d toward the light incident portion 10d in the -Z direction.

[0163] In this modified example, the continuous portion 31 and the discontinuous portion 32 are alternately arranged at the boundary between the light incident portion 10d and the light guide portion 20d in the Y-axis direction. Here, the continuous portion 31 with an opening width A is periodically arranged at a pitch P in the Y-axis direction, and the continuous portion 31 is arranged to be shorter than the discontinuous portion 32, that is, the aperture ratio A / P becomes smaller. As a result, it is possible to suppress the light guided in the light guide portion 20d from being reflected at the +Z end face where the discontinuous portion 32 is located and returning to the light guide portion 20, thereby leaking to the light incident portion 10d through the continuous portion 31, and then leaking to the outside of the light guide 1d.

[0164] The reflecting surface 14 of the light incident portion 10d reflects the light input from the light incident surface 10a toward the continuous portion 31. In particular, the reflecting surface 14 is formed to reflect the light input from a direction orthogonal to the light incident surface 10a (in this case, the Z-axis direction) toward the continuous portion 31. The reflecting surface 14 can be formed in the same manner as the above-mentioned reflecting surfaces 12 and 13. Thus, the light entering the +Z side of the reflecting surface 14 is reflected at a relatively large incident angle (the angle formed by the normal of the reflecting surface and the input direction), the light entering the center is reflected at a moderate incident angle, and the light entering the -Z side is reflected at a relatively small incident angle and is focused toward the continuous portion 31.

[0165] Fig.11The light input to the light guide 1d is shown as light focusing based on the light input portion 10d, light guiding based on the light guiding portion 20d, and light leakage from the light input portion 10d. As described above, since the width A of the continuous portion 31 in the Y-axis direction is small, the light focused on the continuous portion 31 and entering the light guiding portion 20d via the continuous portion 31 is diffused in the light guiding portion 20d. The light reflected on the +Z side of the reflection surface 14 and entering the light guiding portion 20d via the continuous portion 31 enters the ±Z end faces of the light guiding portion 20d at a relatively large inclination, and is reflected relatively many times in the light guiding portion 20d while being guided in the +Y direction. The light reflected on the -Z side of the reflection surface 14 and entering the light guiding portion 20d via the continuous portion 31 enters the ±Z end faces of the light guiding portion 20d at a small inclination, and is reflected relatively few times in the light guiding portion 20d while being guided in the +Y direction. Therefore, the light entering the reflection surface 14 is reflected on the ±Z end surfaces while expanding in a wide angle range as a whole, and is guided in the +Y direction. Here, there is a possibility that the light returns to the light input portion 10d through a continuous portion 31 different from the continuous portion 31 through which the light passes when entering the light guide portion 20d, and leaks to the outside of the light guide body 1d. However, since the aperture ratio A / P is small, light leakage is suppressed.

[0166] In the light guide 1d according to the first modified example, light input to the light input portion 10d in the Z-axis direction via the light input surface 10a can be guided inside the light guide portion 20d along the Y-axis direction by allowing light concentrated by the light input portion 10d to be output from the light output surface 20a with little leakage through the continuous portion 31 provided at the boundary between the light input portion 10d and the light guide portion 20d. In addition, by structurally dividing the light guide 1d into two parts, namely, the light input portion 10d for concentrating light and the light guide portion 20d for guiding light, and by allowing the light input portion 10d to be continuous with the light guide portion 20d via the continuous portion 31 having a width smaller than the non-continuous portion 32, it is possible to suppress leakage of light from the light guide portion 20d to the light input portion 10d via the continuous portion 31.

[0167] In addition, the cross-sectional shape is determined so that each -Z end surface of the plurality of light-concentrating elements 11d is substantially located on the -Z side of the reflection surface 14 of the adjacent light-concentrating element 11. Thus, the continuous portion 31 and the discontinuous portion 32 for one light-concentrating element 11 are substantially located on the -Z side of the reflection surface 14 of the adjacent light-concentrating element 11, and when viewed in the input direction of light (-Z direction in this example), the reflection surfaces 14 of the plurality of light-concentrating elements 11d are connected in the Y-axis direction. Therefore, most of the light input from the light-entering surface 10a in the -Z direction is reflected by the reflection surface 14 and guided to the light-guiding portion 20 via the continuous portion 31.

[0168] In addition, the upper surface (light incident surface 10a of light incident portions 10 and 10d) and the lower surface (-Z surface of light guide portions 20 and 20d) of the light guide 1 involved in the first embodiment and the light guide 1d involved in the modified example can be smooth surfaces. Thus, when the light guides 1 and 1d are installed outdoors, accumulation of dust and the like can be prevented.

[0169] In addition, in the light guide 1 involved in the first embodiment and the light guide 1d involved in the modified example, the light guide portions 20 and 20d are formed into a plate shape extending in the Y-axis direction orthogonal to the input direction of light (Z-axis direction), but are not limited to this, and can also be formed to bend in any direction intersecting the input direction, for example, bend into an arc shape or a spherical shell shape. In addition, the light guide portions 20 and 20d can be formed to bend or bend in any direction from the portion overlapping with the light input portion 10 and 10d, and can also be formed to extend to the light output surface 20a with a widened or reduced width and an increased or reduced thickness. As a result, the light focused by the light input portion 10 is guided into the light guide portion 20, and then guided toward the light output surface 20a in any direction while being reflected on its end face.

[0170] Second embodiment

[0171] Fig. 12A and Fig. 12B The overall structure of the light guide 1d2 involved in the second embodiment, and the structure of the light-returning portion 40 and the boundary portion 70 between the light guide portion 20 and the light guide portion 20 are shown respectively. The light guide 1d2 is an optical device for efficiently collecting light input from the light-incident surface 10a, and guiding the collected light to the light-exiting surface 20a different from the light-incident surface 10a with less leakage and outputting it, and includes the light-incident portion 10, the light-guiding portion 20, the boundary portion 30, the light-returning portion 40, and the boundary portion 70. In addition, the light guide 1d2 as a whole has a roughly plate-like shape that extends in two dimensions with the X-axis direction as the short side and the Y-axis direction as the long side, and has a thickness in the Z-axis direction.

[0172] The light incident portion 10 , the light guiding portion 20 , and the boundary portion 30 are respectively configured in the same manner as the light incident portion 10 , the light guiding portion 20 , and the boundary portion 30 in the light guide 1 d 2 according to the first embodiment.

[0173] The light-returning portion 40 is an example of a light-collecting portion that is provided on a side opposite to the light-entering portion 10 with respect to the light-guiding portion 20 in the Z-axis direction and is provided to receive light that has passed through the light-guiding portion 20. The light-returning portion 40 is an optical component that returns the passing light that has passed through the light-guiding portion 20 (i.e., the leaked light that has leaked from the light-guiding portion 20 to the -Z side) to the light-guiding portion 20, and has a plurality of light-returning elements 41. The plurality of light-returning elements 41 are columnar components that have an inverted substantially concave cross section having a maximum width P in the Y-axis direction and a height h in the Z-axis direction and extend in the X-axis direction, each of which is provided below the plurality of light-collecting elements 11 (on the -Z side), and the +Z sides of the Y-side surfaces (i.e., the +Y side surface and the -Y side surface) are in contact with each other, and the -Z sides are arranged in the Y-axis direction separately from each other. In the present embodiment, the plurality of light-returning elements 41 are coupled to each other and integrally formed (however, in order to facilitate the description of the configuration and function of the light-returning portion 40, it will be described assuming that the light-returning portion 40 includes a plurality of light-returning elements 41). Thus, the light-returning portion 40 extends in the XY direction, and the +Z planes of the plurality of light-returning elements 41 are coupled to each other to form a plane extending in the XY direction. In addition, a hollow space (referred to as space) 40s having a substantially isosceles triangle cross section and extending in the X-axis direction is formed at the center of the -Z plane of the light-returning element 41, and a hollow space (referred to as space) 40t having an isosceles triangle cross section and extending in the X-axis direction is formed between two adjacent light-concentrating elements 11.

[0174] Similar to the light-concentrating element 11, the light-returning element 41 can be formed using a resin having a high refractive index, such as acrylic resin (refractive index 1.49), polycarbonate resin (refractive index 1.58), or glass (for example, a refractive index of 1.51 to 1.53 relative to BK7). Thus, the mutually opposed inclined surfaces formed at the boundary between the light-returning element 41 and the space 40s, that is, at the center of the light-returning element 41, serve as reflection surfaces 42 and 43 for reflecting light input to the light-returning portion 40 from the light-concentrating element 11 located directly above the light-returning element 41 (on the +Z side) through the area between them and the light-guiding portion 20 without being reflected by the reflection surfaces 12 and 13. When light enters the reflection surfaces 42 and 43 from the inside of the light-returning element 41 at an angle above the critical angle, the light is totally reflected. The critical angle is about 42 degrees for acrylic resin, about 41 degrees for polycarbonate resin, and about 42 degrees for glass. Therefore, the inclined surface of the light returning element 41 is formed so that the normal line thereof forms an angle equal to or greater than the critical angle with respect to the input direction of light (the Z-axis direction in this embodiment).

[0175] Fig.13The light-returning principle of the light-returning part is shown. The light-returning element 41 is arranged below the light-collecting element 11. The reflecting surfaces 42 and 43 of the light-returning part 40 (the light-returning element 41) are arranged offset in the Y-axis direction relative to the reflecting surfaces 12 and 13 of the light-entering part 10. In this example, the offset is P / 2. Thus, in the YZ cross section, the reflecting surface 42 reflects the leaked light (bold line in the figure) of the light input into the light-collecting element 11 in the -Z direction via the light-entering surface 10a, which passes through the light-guiding part 20 from the center of the light-collecting element 11 via the +Y side and the -Y side of the reflecting surface 12 and leaks from the -Z surface of the light-guiding part 20 to enter the light-returning element 41 (the light-returning element 41a in this example) toward the continuous part 71 described later. In this example, the reflecting surface 42 reflects toward the continuous part 71 (the rightmost continuous part 71 in the figure) located at the boundary of the two light-returning elements 41b and 41c adjacent to the +Y side of the light-returning element 41a. The reflecting surface 43 reflects the leakage light (not shown) among the light input into the focusing element 11 in the -Z direction via the light incident surface 10a, which passes through the light guiding portion 20 from the center of the focusing element 11 via the -Y side and the +Y side of the reflecting surface 13 and leaks from the -Z surface of the light guiding portion 20 to enter the returning light element 41a toward another continuous portion 71 (located on the boundary of two returning light elements 41 adjacent to the -Y side of the returning light element 41).

[0176] Furthermore, in the light-returning element 41, the boundary between the light-returning element 41 and the space 40t, i.e., the ±Y side surfaces of the light-returning element 41, serve as refractive surfaces 44, 45 for refracting the leaked light reflected by the reflecting surfaces 42, 43 toward the continuous portion 71. Here, the refractive surface 44 formed on the +Y side surface of the light-returning element 41a and the refractive surface 45 formed on the -Y side surface of the light-returning element 41b adjacent to the +Y side of the light-returning element 41a form a part of two circles 49 in contact in the Y-axis direction, i.e., circular arcs facing each other. Thus, the refractive surfaces 44, 45 facing each other and the space 40t therebetween form a focus 49a on the boundary between the light-returning element 41b and the light-returning element 41c adjacent to the +Y side thereof (i.e., at the center of the continuous portion 71). The leakage light reflected by the reflection surface 42 in the light-returning element 41a is emitted to the space 40t through the refractive surface 44, enters the light-returning element 41b through the refractive surface 45 of the light-returning element 41b, is focused at the focal point 49a, and returns to the light-guiding portion 20 through the continuous portion 71. Similarly, the leakage light reflected by the reflection surface 43 in the light-returning element 41a is focused by the refractive surface formed on the -Y side of the light-returning element 41a, the space, and the refractive surface formed on the +Y side of the light-returning element adjacent to the -Y side of the light-returning element 41a, and returns to the light-guiding portion 20 through the continuous portion (none of which is shown).

[0177] The boundary portion 70 is a portion located at the boundary between the light guide portion 20 and the light return portion 40 , and includes a continuous portion 71 and a discontinuous portion 72 .

[0178] The continuous portion 71 is provided so as to physically connect the light guide portion 20 and the light return portion 40, and returns the leaked light reflected by the reflection surfaces 42 and 43 of the light return portion 40 (light return element 41) to the inside of the light guide portion 20. The continuous portion 71 is formed in a plate shape extending in the X-axis direction, and is provided at the boundary between two adjacent light return elements 41. In addition, the continuous portion 31 can be formed of the same material as the light return element 41.

[0179] The discontinuous portion 72 is a portion provided to separate the light guide portion 20 and the light return portion 40 from each other, and is provided between the ±Y ends of the light return element 41 where the continuous portion 71 is located. Since the +Z surface of the light return portion 40 is separated from the light guide portion 20 by the discontinuous portion 72 and a space 70s is formed therebetween, the -Z end surface of the light guide portion 20 serves as a reflection surface that reflects light from the inside of the light guide portion 20 toward the light return portion 40 in the +Z direction.

[0180] In the present embodiment, the continuous portion 71 and the discontinuous portion 72 are alternately arranged at the boundary of the light guide portion 20 and the light return portion 40 in the Y-axis direction. Here, when viewed in the Z-axis direction, at least a portion of the continuous portion 31 and the discontinuous portion 72 are arranged to overlap each other. In addition, the discontinuous portion 72 is arranged so that the separation distance between the light guide portion 20 and the light return portion 40 is constant in the Y-axis direction.

[0181] In addition, the continuous portion 71 is periodically arranged at a pitch P in the Y-axis direction, and the continuous portion 71 is arranged to be shorter than the discontinuous portion 72, that is, the width / pitch P of the continuous portion 71 is reduced. As a result, it is possible to suppress the light guided in the light guide portion 20 from being reflected at the -Z end face where the discontinuous portion 72 is located and returning to the light guide portion 20, and leaking to the light return portion 40 through the continuous portion 71, and then leaking to the outside of the light guide 1.

[0182] Fig.14 The light guiding principle of the light guiding portion 20 is shown. The center of the continuous portion 71 is arranged to be offset in the Y-axis direction relative to the reflection surfaces 42, 43 of the light returning portion 40 (light returning element 41) and the reflection surfaces 12, 13 of the light incident portion 10 (light focusing element 11). In the present embodiment, it is arranged below the boundary between two adjacent light focusing elements 11 (-Z side). Alternatively, it may be arranged below the reflection surfaces 12 and 13 of the light focusing element 11. Thus, light from the light focusing element 11 that is not reflected by the reflection surfaces 12 and 13 and enters the light guiding portion 20 via the area between them will not enter the light returning portion 40 via the continuous portion 71.

[0183] In addition, a discontinuous portion 72 is formed widely on the +Z surface of the light-returning element 41 to reflect light reflected by the reflecting surfaces 12 and 13 of the light-entering portion 10 and entering the light-guiding portion 20 via the continuous portion 31. Here, light reflected on the +Z side of the reflecting surface 13 passes through the continuous portion 31 at a small angle relative to the Z axis, enters the vicinity of the -Y end of the discontinuous portion 72 on the light-returning element 41 adjacent to the +Y side at an angle greater than the critical angle, light reflected at the center of the reflecting surface 13 passes through the continuous portion 31 at a moderate angle relative to the Z axis, enters the center of the discontinuous portion 72 at an angle greater than the critical angle, and light reflected on the -Z side of the reflecting surface 13 passes through the continuous portion 31 at a large angle relative to the Z axis, enters the vicinity of the +Y end of the discontinuous portion 72 at an angle greater than the critical angle, and is reflected on the reflecting surfaces on the discontinuous portion 72, respectively. Most of the light entering the light guide portion 20 via the reflective surfaces 12 and 13 of the light incident portion 10 and the continuous portion 31 can be reflected by the reflective surface on the discontinuous portion 72 and returned to (enclosed in) the light guide portion 20 .

[0184] Fig.15 The fourth manufacturing method flow S400 of the light guide 1d4 is shown. In this embodiment, acrylic resin is used as a molding material of the light guide 1d2 as an example. That is, the light incident portion 10, the light guide portion 20 and the light return portion 40 are formed of the same material.

[0185] In step S402, the light incident portion 10 is formed. The light incident portion 10 may be formed through the above steps S201 to S203. Fig.16A The structure of the molded light incident portion 10 is shown. The light incident portion 10 is formed as a body separate from the light guide portion 20 and the light return portion 40.

[0186] In step S404, the light guide portion 20 is molded. Details of the molding are omitted. Fig. 16B The structure of the molded light guide portion 20 is shown. The light guide portion 20 is formed as a body separate from the light incident portion 10 and the light returning portion 40.

[0187] In step S406, the light-returning portion 40 is molded. The light-returning portion 40 can be molded by the same method as the light-incident portion 10. That is, the light-returning portion 40 is formed by covering a mold including an internal space having a size and shape capable of accommodating the light-returning portion 40 and having a plurality of grooves having a cross-sectional shape complementary to the continuous portion 71 arranged in the Y-axis direction on the top surface with a mold having a plurality of protruding edges having a cross-sectional shape complementary to the spaces 40s and 40t arranged in the Y-axis direction on the upper surface to form an internal space therebetween, and extracting acrylic resin in the internal space to form the light-returning portion 40.

[0188] Fig. 16CThe structure of the molded light-returning part 40 is shown. In the light-returning part 40, a plurality of light-returning elements 41 are coupled in the Y-axis direction, a continuous part 71 is provided on the boundary of the adjacent light-returning elements 41 on the +Z plane, and spaces 40s and 40t arranged in the Y-axis direction are formed on the -Z plane.

[0189] In step S406, the light-incoming portion 10, the light-guiding portion 20, and the light-returning portion 40 are welded to form the light-guiding body 1d2. Fig.16D As shown, for the light incident portion 10, one end surface formed with the space 30s is disposed on the +Z end surface of the light guide portion 20 toward the -Z side, and for the light return portion 40, one end surface formed with the spaces 40s and 40t is disposed on the -Z end surface of the light guide portion 20 toward the -Z side. Thus, the continuous portion 31 integrally formed with the -Z surface of the light incident portion 10 abuts against the +Z end surface of the light guide portion 20, and the continuous portion 71 integrally formed with the +Z surface of the light return portion 40 abuts against the -Z end surface of the light guide portion 20. In this state, the light incident portion 10, the light guide portion 20, and the light return portion 40 are welded by applying ultrasonic vibration to at least one of them. Thus, the light incident portion 10 and the light guide portion 20 are bonded to each other via the continuous portion 31, and the light guide portion 20 and the light return portion 40 are bonded to each other via the continuous portion 71, thereby forming the light guide body 1d2.

[0190] In addition, the light incident portion 10, the light guide portion 20, and the light return portion 40 may be bonded together by using, for example, a solvent, without being limited to welding. In addition, the light guide 1d2 may be molded using a 3D printer.

[0191] The light guide 1d2 involved in the second embodiment is an optical device that guides light input from a light input surface 10a to a light output surface 20a different from the light input surface 10a and outputs light from the light output surface 20a, and comprises a light input portion 10 having a light input surface 10a for inputting light in the Z-axis direction; a light guide portion 20 arranged on the side of the light output surface 20a and guiding light in the Y-axis direction and outputting light from the light output surface 20a; a continuous portion 31 and a non-continuous portion 32 that are respectively arranged at the boundary between the light input portion 10 and the light guide portion 20 and make the light input portion 10 and the light guide portion 20 continuous and separate the light input portion 10 and the light guide portion 20; and a light return portion 40 that is arranged on the opposite side of the light input portion 10 relative to the light guide portion 20 in the Z-axis direction and returns the leaked light from the light guide portion 20 to the light guide portion 20. Thus, light that is not reflected by the reflecting surfaces 12 and 13 from the light incident portion 10 (light focusing element 11) and is input into the light returning portion 40 via the area therebetween and the light guiding portion 20, i.e., leakage light, is returned to the light guiding portion 20 through the light returning portion 40, thereby enabling most of the light entering the light incident portion 10 to be sealed within the light guiding portion 20 and output from the light emitting surface 20a.

[0192] Fig.17The structure of the light guide 1d3 involved in the second modified example is shown. Compared with the light guide 1d2 involved in the second embodiment, the light guide 1d3 further includes a bottom 48. The bottom 48 is formed into a plate-like shape with the long side in the Y-axis direction using the same material as the light-returning portion 40, and is fused to the -Z surface of the light-returning portion 40. In addition, the bottom 48 and the light-returning portion 40 can also be formed integrally. As a result, the leakage light that is not reflected by the reflection surfaces 42 and 43 and leaks to the -Z side can be reflected by the -Z surface of the bottom 48, guided and sealed in the Y-axis direction inside the bottom 48, and returned to the +Z direction.

[0193] Fig.18 The structure of the light guide 1d4 involved in the third variant is shown. The light guide 1d4 has a light-returning portion 40d, and the light-returning portion 40d forms a space 40s only on the -Z plane relative to the light-returning portion 40 of the light guide 1d2 involved in the second embodiment. Here, a reflective film can be provided on the reflective surfaces 42 and 43 using metal or the like, so that even if the leakage light enters at an angle below the critical angle, it can be totally reflected. In addition, the reflective surfaces 42 and 43 can also be curved or bent in a parabolic shape, so that the leakage light reflected by the reflective surfaces 42 and 43 is focused on the continuous portion 71 on the boundary of the two adjacent light-returning elements 41 on the +Y side. Thus, light that is not reflected by the reflecting surfaces 12 and 13 from the light incident portion 10 (light focusing element 11) and is input into the light returning portion 40 via the area therebetween and the light guiding portion 20, i.e., leakage light, is returned to the light guiding portion 20 through the light returning portion 40, thereby enabling most of the light entering the light incident portion 10 to be sealed within the light guiding portion 20 and output from the light emitting surface 20a.

[0194] In addition, in the light guide 1d2 involved in the second embodiment and the light guides 1d3 and 1d4 involved in the second and third modified examples, the light guide portion 20 is formed in a plate shape extending in the Y-axis direction orthogonal to the input direction of light (Z-axis direction), but is not limited to this, and can also be formed to bend in any direction intersecting the input direction, for example, bend into an arc shape or a spherical shell shape. In addition, the light guide portion 20 can be formed to bend or bend in any direction from the portion overlapping with the light input portion 10, and can also be formed to extend to the light output surface 20a with a widened or reduced width and an increased or reduced thickness. As a result, the light focused by the light input portion 10 is guided into the light guide portion 20, and then guided to the light output surface 20a along any direction while being reflected on its end face.

[0195] In addition, it is also possible to configure the light output from the light output surface 20a of the light guide 1d2, 1d3, 1d4 to be input to another light guide (optical fiber, etc.) different from the light guide 1d2, 1d3, 1d4, and output (emit light) at the other end of the other light guide.

[0196] Third embodiment

[0197] Fig.19A and Fig.19B The overall structure of the light guide 100 involved in the third embodiment, and the structure of the light input portion 110 and the boundary portion 130 between the light input portion 110 and the light guide portion 120 are respectively shown. The light guide 100 is an optical device that efficiently collects light input from the light input surface 110a, and guides the collected light to the light output surface 120a different from the light input surface 110a without leakage or with little leakage, and outputs the light, and includes the light input portion 110, the light guide portion 120, and the boundary portion 130. In addition, the light guide 100 as a whole has a roughly plate shape that extends in two dimensions with the X-axis direction as a short side and the Y-axis direction as a long side, and has a thickness in the Z-axis direction.

[0198] The light input portion 110 is an optical component that focuses light input in an input direction (in the -Z direction in this embodiment) via the light input surface 110a, and has a plurality of focusing elements 111. The plurality of focusing elements 111 are columnar components extending in the X-axis direction, having an inverted substantially isosceles trapezoidal cross section with a maximum width P in the Y-axis direction and a height d in the Z-axis direction, and are in contact with each other on the +Z side of the Y side (i.e., the +Y side and the -Y side), and are arranged in the Y-axis direction separated from each other on the -Z side. In this embodiment, the plurality of focusing elements 111 are coupled to each other and integrally formed (however, in order to facilitate the description of the configuration and function of the light input portion 110, it is assumed that the light input portion 110 includes a plurality of focusing elements 111 for description). Thus, the light input portion 110 extends in the Y-axis direction, and the +Z surfaces of the plurality of focusing elements 111 are coupled to each other to form a planar light input surface 110a having a width in the X-axis direction. As described above, the light input surface 110a is configured to input light from the +Z side. Furthermore, two adjacent light-condensing elements 111 form a hollow space (referred to simply as a space) 130s having a triangular cross section and extending in the X-axis direction therebetween.

[0199] In addition, the plurality of light concentrating elements 111 may be arranged to be separated from each other in the Y-axis direction. In this case, each of the +Z surfaces of the plurality of light concentrating elements 111 serves as an independent light incident surface.

[0200] The focusing element 111 has reflecting surfaces 112, 113 and a light-transmitting portion 114 located below (in the -Z direction) relative to the light incident surface 110a. Here, the focusing element 111 can be formed using a resin having a high refractive index, such as acrylic resin (refractive index 1.49), polycarbonate resin (refractive index 1.58), or glass (for example, a refractive index of 1.51 to 1.53 relative to BK7). The boundary between the focusing element 111 and the space 130s, that is, the ±Y side surfaces of the focusing element 111, serve as reflecting surfaces 112, 113 that reflect a portion of the light input into the focusing element 111 via the light incident surface 110a. When light enters the ±Y side surfaces from the inside of the focusing element 111 at an angle greater than the critical angle, the light is totally reflected. The critical angle is approximately 42 degrees for acrylic resin, approximately 41 degrees for polycarbonate resin, and approximately 42 degrees for glass. Therefore, the ±Y side surfaces of the light-concentrating element 111 are formed so that the normal lines thereof form an angle greater than the critical angle with respect to the input direction of the light (in this embodiment, the Z-axis direction). On the other hand, the portion between the reflecting surfaces 112 and 113 in the light-concentrating element 111 serves as a light-transmitting portion 114, which allows a portion of the light input from the light-incident surface 110a (in this example, the remaining portion that does not enter the reflecting surfaces 112 and 113) and the reflected light reflected by the reflecting surfaces 112 and 113 to pass through.

[0201] The reflective surfaces 112 and 113 are respectively located on the +Y side and -Y side of the light-transmitting portion 114 and are arranged opposite to each other to reflect the light input from the light-entering surface 110a toward the light-transmitting portion 114. Here, the reflective surfaces 112 and 113 are formed in a straight line shape on the YZ cross section. In addition, in order to increase the reflectivity, the reflective surfaces 112 and 113, that is, the ±Y side surfaces of the focusing element 111, can be mirror-finished. In addition, a reflective film can also be provided using metal or the like.

[0202] The light guide portion 120 is an optical component having a light output surface 120a located at the -Z side relative to the light input portion 110, and guides the reflected light reflected by the reflection surfaces 112 and 113 of the light input portion 110 along the +Y direction and / or the -Y direction and outputs it from the light output surface 120a. The light guide portion 120 is formed in a plate shape extending in the Y-axis direction. Here, the width of the light guide portion 120 in the X-axis direction is equal to (or may be greater than) the width of the light input portion 110, the length in the Y-axis direction is greater than (or may be equal to) the length of the light input portion 110, and the thickness in the Z-axis direction is greater than (or may be arbitrarily determined) the thickness of the light input portion 110. The +Y side surface and / or the -Y side surface of the light guide portion 120 form the light output surface 120a for outputting light, and the -Z end surface 120b is formed in a planar shape, thereby serving as a reflection surface that reflects the light guided into the light guide portion 120 inwardly.

[0203] The light guide 120 may be formed of the same material as the light incident portion 110 (light focusing element 111). In order to increase the reflectivity, the -Z end surface 120b of the light guide 120 may be mirror-finished. Alternatively, a reflective film may be provided using metal or the like.

[0204] The boundary portion 130 is a portion located at the boundary between the light incident portion 110 and the light guide portion 120 , and includes a continuous portion 131 and a discontinuous portion 132 .

[0205] The continuous portion 131 is provided so that the light-transmitting portion 114 of the light incident portion 110 and the light-guiding portion 120 are physically continuous, so as to guide the light input from the light incident surface 110a, that is, the reflected light reflected on the reflecting surfaces 112 and 113 and the remaining light that has not entered the reflecting surfaces 112 and 113, into the light-guiding portion 120. The continuous portion 131 has an opening width A in the Y-axis direction and extends in the X-axis direction. In addition, the continuous portion 131 can be formed of the same material as the focusing element 111. In addition, the continuous portion 131 can also be formed integrally with the light incident portion 110 and / or the light-guiding portion 120 as a part thereof.

[0206] The discontinuous portion 132 is provided so that the reflective surfaces 112 and 113 of the light incident portion 110 are separated from the light guide portion 120, and are respectively arranged adjacent to the ±Y sides of the continuous portion 131. Since the light guide portion 120 is separated from the light incident portion 110 (the reflective surfaces 112 and 113 formed on the ±Y side surfaces) by the discontinuous portion 132, and a space 130s is formed therebetween, the interface between the discontinuous portion 132 and the light guide portion 120 is used to reflect and guide the reflected light input from the light-transmitting portion 114 of the light incident portion 110 to the light guide portion 120 via the continuous portion 131 to the reflective surface of the light exit surface 120a. In addition, in order to increase the reflectivity, the interface between the discontinuous portion 132 and the light guide portion 120, that is, the +Z end surface of the light guide portion 120 below the space 130, may be mirror-finished. In addition, a reflective film may be provided using metal or the like.

[0207] In the third embodiment, for the reflective surfaces 112, 113 and the light-transmitting portion 114 of the light-entering portion 110, the light-entering portion 110 is formed by arranging the focusing element 111 in the Y-axis direction, so that a plurality of the light-entering portions 110 are arranged in the Y-axis direction in the light-entering portion 110. Accordingly, for the continuous portion 131 and the discontinuous portion 132, a plurality of them are respectively arranged at the boundary between the light-entering portion 110 and the light-guiding portion 120, and the plurality of continuous portions 131 and the plurality of discontinuous portions 132 are alternately arranged along the Y-axis direction. Here, the continuous portion 131 has a width A (equal to the width of the light-transmitting portion 114) in the Y-axis direction, and is periodically arranged at a pitch P in the Y-axis direction. In the present embodiment, the discontinuous portion 132 has substantially the same width as the continuous portion 131, and is arranged between the continuous portions 131. Thus, the aperture ratio A / P is approximately one-half.

[0208] like Fig.19B As shown, the reflective surfaces 112 and 113 of the light incident portion 110 reflect the light input from the light incident surface 110a toward the continuous portion 131. In particular, the reflective surfaces 112 and 113 reflect the light input from the direction orthogonal to the light incident surface 110a (in the Z-axis direction in this embodiment) toward the continuous portion 131. Here, the light reflected by the reflective surface 112 forms parallel light and passes through the continuous portion 131, that is, the light reflected on the +Z side of the reflective surface 112 passes through the +Y side of the continuous portion 131, the light reflected at the center of the reflective surface 112 passes through the center of the continuous portion 131, and the light reflected on the -Z side of the reflective surface 112 passes through the -Y side of the continuous portion 131, and then enters the light guide portion 120. In addition, for the light reflected by the reflective surface 113, except that the direction of light propagation is opposite, it forms parallel light and enters the light guide portion 120 in the same manner as the light reflected by the reflective surface 112.

[0209] In addition, the discontinuous portion 132 is provided below the reflecting surfaces 112 and 113 of the light incident portion 110, thereby including a discontinuous portion 132b separating the reflecting surface 112 and the light guiding portion 120, and a discontinuous portion 132a separating the reflecting surface 113 and the light guiding portion 120. In addition, in the light incident portion 110, the light focusing elements 111 are arranged in the Y-axis direction, so that a space 130s having a triangular cross-section when viewed in the Y direction is formed inside the Y-side surfaces of two adjacent light focusing elements 111 and the discontinuous portion 132 (+Z end of the light guiding portion 120), and the reflecting surfaces 112 and 113 of the two adjacent light focusing elements 111 face away from each other through the space 130s, and the discontinuous portions 132 located below each are continuous.

[0210] In addition, the end of the discontinuous portion 132 on the light guide portion 120 side (i.e., the interface between the light guide portion 120 and the discontinuous portion 132) is inclined relative to the Y-axis direction. Here, the interface between the light guide portion 120 and each of the adjacent discontinuous portions 132 is inclined in different directions relative to the Y-axis direction. The interface between the light guide portion 120 and the discontinuous portion 132a is inclined in the clockwise direction relative to the Y-axis, and the interface between the light guide portion 120 and the discontinuous portion 132b is inclined in the counterclockwise direction relative to the Y-axis. The discontinuous portion 132 arranged in the Y-axis direction includes the discontinuous portions 132a and the discontinuous portions 132b arranged alternately.

[0211] In addition, the reflecting surfaces 112 and 113 opposing each other of a focusing element 111 have opposite directions and equal inclination angles relative to the Z axis. Here, the inclination angles may be different from each other in each of the adjacent focusing elements 111, or may be different alternately. The reflecting surfaces 112 and 113 facing each other with a space 130s between two adjacent focusing elements 111 have different inclination angles. In addition, the triangular cross-sections of the multiple spaces 130s arranged in the Y-axis direction may also be rotated alternately in different directions. Here, the rotation of the multiple spaces 130s is a rotation around a reference axis parallel to the X-axis direction passing through the center of the space 130s on the YZ plane. In this example, relative to the state before rotation shown by the dotted line in the figure (i.e., the state in which the base of the triangle is parallel to the Y-axis direction), the left space 130sa rotates clockwise and the right space 130sb rotates counterclockwise. Thus, the clockwise rotating space 130sa and the counterclockwise rotating space 130sb are alternately arranged in the Y-axis direction.

[0212] In addition, when the plurality of spaces 130s do not rotate, the boundary portion 130 between the light incident portion 110 and the light guide portion 120 forms a straight line extending in the Y-axis direction in the YZ plane, and the continuous portion 131 and the discontinuous portion 132 are also linearly continuous in the YZ plane. When the plurality of spaces 130s rotate, the boundary portion 130 repeatedly bends in the ±Z directions in the YZ plane to form a non-straight line extending in the Y-axis direction, and the continuous portion 131 and the discontinuous portion 132 are also non-linearly continuous in the YZ plane.

[0213] Fig. 20The light input to the light guide 1 is shown by focusing the light incident portion 110 and guiding the light by the light guiding portion 120. As an example, the optical path of light entering from the light incident surface 110a in the -Z direction and reflected by the reflecting surface 113 (the right inclined surface of the space 130sa on the far left in the figure) of the light incident portion 110 is shown. As described above, since the opening width A of the continuous portion 131 is large (the opening ratio A / P≈0.5), the light reflected by the reflecting surface 113 (reflected light) passes through the continuous portion 131 while maintaining parallel light and enters the light guiding portion 120. The reflected light entering the light guiding portion 120 is reflected by the -Z end surface 120b of the light guiding portion 120 and returns along the +Z direction, is reflected at the interface between the discontinuous portion 132, that is, the discontinuous portion 132b below the three right adjacent spaces 130sb relative to the space 130sa below the reflecting surface 113 in this example, is reflected at the -Z end surface 120b of the light guiding portion 120 and returns along the +Z direction, is further reflected at the interface between the discontinuous portion 132b below the two right adjacent spaces 130sb, is guided along the right direction inside the light guiding portion 120, and is output from the light exit surface 120a. Since the interfaces between the discontinuous portions 132 (discontinuous portions 132a, 132b) and the light guide portion 120 arranged in the Y-axis direction are alternately inclined in different directions, and the reflecting surfaces 112, 113 of the light focusing element 111 arranged in the Y-axis direction have alternately different inclination angles (the absolute value of the inclination angle relative to the Z-axis), the light reflected by the reflecting surface 113 is reflected at the interface of the same discontinuous portion 132 (the discontinuous portion 132b in this example) and guided within the light guide portion 120. In addition, the inclination angles of the discontinuous portions 132a and 132b and / or the inclination angles of the reflecting surfaces 112 and 113 are determined so that the light entering the light guide portion 120 from the light focusing element 111 does not leak from the light guide 100 in the +Z direction through the light-transmitting portions 114 of different light focusing elements 111, i.e., is reflected at the interfaces of a plurality of discontinuous portions 132.

[0214] The light guide 100 according to the third embodiment can be manufactured in the same manner as the light guide 1 according to the first embodiment.

[0215] Fig.21 A light guide assembly 100a according to a third embodiment is shown. The light guide assembly 100a includes two light guides 100 that overlap in the Z-axis direction. Here, the upper light guide 100 is disposed on the light incident surface 110a of the lower light guide 100. A small gap is provided between the light incident surface 110a of the lower light guide 100 and the -Z plane of the upper light guide 100. In addition, the lower light guide 100 is also an example of a light focusing portion that is provided on the opposite side of the light incident portion 110 relative to the light guide portion 120 of the upper light guide 100 in the Z-axis direction and to which light that has passed through the upper light guide portion 120 is input.

[0216] In each of the two light guides 100, the light input portion 110 is formed to be symmetrically rotated 180 degrees relative to the Z-axis direction. In the light guide 100 in the upper stage, the reflection surface 112 is located at the +Y end surface, and the reflection surface 113 is located at the -Y end surface. The light guide portion 120 is also formed to be symmetrically rotated 180 degrees relative to the Z-axis direction. Here, the distance L from the +Y end of the light guide portion 120 to the reflection surface 112 of the light input portion 110 closest to the +Y end is 112 and the distance L from the -Y end of the light guide 120 to the light incident portion 110 closest to the -Y end 113 The difference is substantially equal to the width of the continuous portion 131 and the discontinuous portion 132 in the Y-axis direction, that is, half of the arrangement pitch P of the plurality of light focusing elements 111 .

[0217] Therefore, in the light guide assembly 100a, the light guide 100 of the lower section is rotated 180 degrees relative to the light guide 100 of the upper section with respect to the Z axis. Thus, the reflecting surface 113 is located at the +Y end surface of the light incident portion 110, and the reflecting surface 112 is located at the -Y end surface. Furthermore, the light guide 100 of the upper section is set on the light incident surface 110a of the light guide 100 of the lower section, and each ±Y end surface is aligned. Thus, the focusing elements 111 of the upper section of the light guide 100 are arranged with an offset of P / 2 in the Y axis direction relative to the focusing elements 111 of the lower section of the light guide 100, and the reflecting surfaces 112 and 113 of the multiple focusing elements 111 of the lower section of the light guide 100 are respectively located below the light-transmitting portion 114 of the multiple focusing elements 111 of the light guide 100 of the upper section (-Z direction).

[0218] Fig. 22 The principle of focusing light by the light input portion 110 and guiding light by the light guide portion 120 of the light input to the light guide assembly 100a is shown. Here, the optical path of light that is not reflected by the reflective surfaces 112 and 113 of the light input portion 110 of the light guide 100 in the upper section and enters the light guide portion 120 via the light-transmitting portion 114 therebetween (the light-transmitting portion 114 of the focusing element 111 on the left side of the figure) is shown. In addition, the light guiding of the light entering the reflective surfaces 112 and 113 of the light input portion 110 is as described previously with reference to FIG. Figure 2 As described.

[0219] The light entering the light guide portion 120 via the light-transmitting portion 114 of the light-entering portion 110 leaks to the outside of the upper light guide 100 through the -Z end surface 120b of the light guide portion 120, and enters the lower light guide 100 from the light-entering surface 110a along the -Z direction. Here, since the reflective surfaces 112 and 113 of the lower light guide 100 are located below the light-transmitting portion 114 of the upper light guide 100, the light passing through the +Y side of the light-transmitting portion 114 of the upper section is reflected by the reflective surface 113 on the +Y side of the lower section, and enters the lower light guide portion 120 through the continuous portion 131 while maintaining parallel light. The reflected light entering the light guide portion 120 is as previously described with reference to FIG. Figure 2 As described, the light is reflected at the -Z end surface 120 b of the light guide portion 120 and the interface between the light guide portion 120 and the discontinuous portion 132 , guided in the right direction inside the light guide portion 120 , and output from the light output surface 120 a .

[0220] In addition, the light (not shown) passing through the -Y side of the light-transmitting portion 114 of the upper stage is reflected at the reflective surface 112 of the -Y side of the lower stage, passes through the adjacent continuous portion 131 while maintaining parallel light, and enters the light-guiding portion 120 of the lower stage. The reflected light entering the light-guiding portion 120 is guided in the left direction inside the light-guiding portion 120 and output from the other light-emitting surface 120a.

[0221] In this way, light that is emitted to the outside of the light guide 100 from the light entrance portion 110 (light focusing element 111) of the upper light guide 100 through the light transmitting portion 114 and the light guide portion 120 therebetween without being reflected by the reflective surfaces 112 and 113, i.e., leakage light, is focused by the lower light guide 100, thereby enabling most of the light entering the light guide assembly 100a to be sealed in the light guide portion 120 and output from the light output surface 120a.

[0222] Fig.23 The structure and focusing principle of the light guide assembly 100b involved in the modified example are shown. The light guide assembly 100b has three light guides 100 overlapping in the Z-axis direction. Here, the middle light guide 100 is arranged on the light incident surface 110a of the lower light guide 100, and the upper light guide 100 is arranged on the light incident surface 110a of the middle light guide 100. A small gap is set between the three light guides 100. In each light guide 100, the width of the continuous part 131 is twice that of the non-continuous part 132, and the three light guides 100 are arranged so that each focusing element 111 is offset by P / 3 in the Y-axis direction. As a result, the reflective surfaces 112 and 113 of the focusing elements 111 of the middle and lower light guides 100 are located below the light-transmitting part 114 of the focusing element 111 of the upper light guide 100 (-Z direction).

[0223] Among the light entering the light incident surface 110a of the upper light guide 100, the light I11 and I12 are respectively reflected by the reflection surfaces 112 and 113 of the upper light incident portion 110, guided in the upper light guide portion 120, and output from the emission surface 120a. Among the light passing through the light transmitting portion 114 between the reflection surfaces 112 and 113 of the upper light guide 100, the light I21 and I22 passing through the -Y side are respectively reflected by the reflection surfaces 112 and 113 of the middle light incident portion 110, guided in the middle light guide portion 120, and the light I31 and I32 passing through the +Y side are respectively reflected by the reflection surfaces 112 and 113 of the lower light incident portion 110, guided in the lower light guide portion 120, and output from the light exit surface 120a of each light guide 100. In this way, the width of the reflective surfaces 112, 113 and the continuous portion 131 of the light incident portion 110 can be changed (1 to N-1), and the light guide 100 can be stacked in multiple (N) sections and offset in P / N configuration in the Y-axis direction to form a light guide assembly.

[0224] The light guide 100 involved in the third embodiment is a light guide that guides light input from the light input surface 110a to the light output surface 120a and outputs from the light output surface 120a, and has a light input surface 110a to which light is input in the -Z direction, reflecting surfaces 112 and 113 located in the -Z direction relative to the light input surface 110a, and a light transmitting portion 114, wherein the reflecting surfaces 112 and 113 reflect a portion of the light input from the light input surface 110a, and the light transmitting portion 114 has a light receiving surface 110a that receives the other portion of the light input from the light input surface 110a, and a light receiving surface 114 that receives the light. A light incident portion 110 through which reflected light reflected by reflections from reflections 112 and 113 passes; a light guiding portion 120 having a light emitting surface 120a located on the -Z side relative to the light incident portion 110 and guiding the reflected light in the Y-axis direction to be output from the light emitting surface 120a; and a continuous portion 131 respectively arranged at the boundary of the light incident portion 110 and the light guiding portion 120 and configured so that the light transmitting portion 114 and the light guiding portion 120 are continuous with each other, and a non-continuous portion 132 configured so that the reflecting surfaces 112 and 113 and the light guiding portion 120 are separated from each other. Thus, a portion of the light input into the light incident portion 110 in the -Z direction via the light incident surface 110a is reflected by the reflective surfaces 112 and 113 of the light incident portion 110, and the reflected light enters the light guiding portion 120 from the light transmitting portion 114 of the light incident portion 110 via the continuous portion 131, and is guided along the Y-axis inside the light guiding portion 120, thereby being able to output most of the light focused by the light incident portion 110 from the light exit surface 120a.

[0225] In addition, the light guide assembly 100a involved in the third embodiment includes two light guides 100 that overlap in the Z-axis direction. According to this structure, light that is not reflected by the reflection surfaces 112 and 113 from the light input portion 110 (light focusing element 111) of the upper light guide 100 and is emitted to the outside of the light guide 100 via the light-transmitting portion 114 and the light guide portion 120 therebetween, i.e., leakage light, is focused by the lower light guide 100, thereby enabling most of the light entering the light guide assembly 100a to be sealed in the light guide portion 120 and output from the light output surface 120a.

[0226] In addition, the upper surface (light incident surface 110a of light incident portion 110) and the lower surface (-Z surface of light guide portion 120) of light guide 100 according to the third embodiment may be smooth surfaces, thereby preventing accumulation of dust when light guide 100 is installed outdoors.

[0227] In addition, in the light guide 100 involved in the third embodiment, the light guide portion 120 is formed in a plate shape extending in the Y-axis direction orthogonal to the input direction of light (Z-axis direction), but is not limited to this, and can also be formed to bend in any direction intersecting the input direction, for example, bend into an arc shape or a spherical shell shape. In addition, the light guide portion 120 can be formed to bend or bend in any direction from the portion overlapping with the light input portion 110, and can also be formed to extend to the light output surface 120a with a widened or reduced width and an increased or reduced thickness. Thus, the light focused by the light input portion 110 is guided into the light guide portion 120, and then guided to the light output surface 120a along any direction while being reflected by its end face.

[0228] Alternatively, the light output from the light output surface 120a of the light guide 100 may be input to another light guide (optical fiber, etc.) different from the light guide 100 and output (emit light) at the other end of the other light guide.

[0229] The present invention has been described above using the embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. It is obvious from the description of the claims that such changes or improvements can also be included in the technical scope of the present invention.

[0230] Regarding the execution order of each process of actions, processes, steps, and steps in the devices, systems, programs, and methods shown in the claims, specifications, and drawings, it should be noted that there is no special indication of "before", "preceding", etc., and in addition, as long as the output of the previous process is not used in the subsequent process, it can be implemented in any order. For the action flow in the claims, specifications, and drawings, even if "first", "next", etc. are used for convenience, it does not mean that it must be implemented in such an order.

[0231] [Description of Reference Numerals]

[0232] 1, 1d, 1d2, 1d3, 1d4…light guide; 10, 10d…light entrance; 10a…light entrance surface; 11, 11d…light focusing element; 12, 13, 14…reflection surface; 19…parabola; 19a…directrix; 19b…focus; 20, 20d…light guide; 20a…light exit surface; 20d…light guide; 30, 30d…boundary; 30s, 30t…space; 31…continuous portion; 32…discontinuous portion; 40, 40d…light return portion; 40s, 40t…space; 41, 41a, 41b…light return element; 42, 43…reflection surface; 44, 45…refractive surface; 48…bottom; 49…circle; 49a…focus; 50s…internal space; 51, 52…mold; 53…insert; 61, 62, 63…mold; 61s, 63s…internal space; 62a…protruding edge; 65…insert; 70…boundary portion; 70s…space; 71…continuous portion; 72…discontinuous portion; 80…incident angle; 99…moving trajectory plane; 100…light guide; 100a, 100b…light guide assembly; 110…light incident portion; 110a…light incident surface; 111…light focusing element; 112, 113…reflecting surface; 114…light transmitting portion; 120…light guiding portion; 120a…light emitting surface; 120b…-Z end face; 130…boundary portion; 130s, 130sa, 130sb…space; 131…continuous portion; 132, 132a, 132b…discontinuous portion; I11, I12, I21, I22, I31, I32…light.

Claims

1. A light guide for guiding light input from a light incident surface to a light exit surface different from the light incident surface and outputting light from the light exit surface, comprising: a light incident portion having the light incident surface configured to input the light from a first direction; A light guide portion, arranged on the light output surface side relative to the light incident portion, guides the light in a second direction intersecting the first direction and outputs the light from the light output surface; and The continuous portion and the discontinuous portion are respectively arranged at the boundaries between the light incident portion and the light guiding portion. The continuous portion is arranged so that the light incident portion and the light guiding portion are continuous, and the discontinuous portion is arranged so that the light incident portion and the light guiding portion are separated.

2. The light guide according to claim 1, wherein: A plurality of the continuous portions and a plurality of the discontinuous portions are provided at the boundaries between the light incident portion and the light guiding portion, respectively, and the plurality of the continuous portions and the plurality of the discontinuous portions are alternately arranged along the second direction.

3. The light guide according to claim 2, wherein: The continuous portion and the discontinuous portion are configured such that a length of the continuous portion is smaller than a length of the discontinuous portion in the second direction.

4. The light guide according to any one of claims 1 to 3, wherein: The light incident portion includes a reflective surface provided to reflect the light input from the light incident surface toward the continuous portion.

5. The light guide according to claim 4, wherein: The reflecting surface is formed to reflect the light input from a direction perpendicular to the light incident surface toward the continuous portion.

6. The light guide according to claim 5, wherein: The reflecting surface is formed by bending or curving in a cross section including the first direction and the second direction.

7. The light guide according to claim 5 or 6, wherein: Another reflecting surface is further provided, and the other reflecting surface is arranged opposite to the reflecting surface and reflects the light input from the light incident surface toward the continuous portion.

8. The light guide according to any one of claims 1 to 7, wherein: The light incident portion extends in the second direction, and the light incident surface is formed in a planar shape having a width in a third direction intersecting the first direction and the second direction.

9. The light guide according to claim 8, wherein: The light guiding portion is formed to extend in the second direction.

10. The light guide according to claim 9, wherein: In the first direction, an end portion of the light guide portion on the opposite side to the light incident portion is formed in a planar shape.

11. The light guide according to any one of claims 8 to 10, wherein: The continuous portion is formed to extend in the third direction.

12. The light guide according to claim 11, wherein: The continuous portion is configured such that the third direction is substantially parallel to a plane including a movement trajectory of the sun.

13. The light guide according to any one of claims 1 to 12, wherein: The light incident portion and the light guide portion are respectively formed as separate bodies, and are formed by being joined to each other via the continuous portion.

14. The light guide according to claim 13, wherein: The light incident portion and the light guide portion are joined by welding.

15. The light guide according to any one of claims 1 to 14, wherein: The light incident portion and the light guide portion are formed of the same material.

16. The light guide according to any one of claims 1 to 15, wherein: The discontinuous portion includes a first discontinuous portion in which the separation distance between the light incident portion and the light guiding portion is constant along the second direction, and a second discontinuous portion in which the separation distance between the light incident portion and the light guiding portion is not constant along the second direction.

17. The light guide according to claim 16, wherein: The light incident portion has a reflecting surface, and the reflecting surface is configured to reflect the light input from the light incident surface toward the continuous portion. The opposite surface of the reflecting surface toward the light guiding portion is provided as an end portion of the second discontinuous portion on the light incident portion side.

18. The light guide according to any one of claims 1 to 15, wherein: A light collecting portion is further provided. The light collecting portion is arranged on the opposite side of the light incident portion with respect to the light guiding portion in the first direction and is provided to input the light having passed through the light guiding portion.

19. The light guide according to claim 18, wherein: It also has other continuous parts and other discontinuous parts, which are respectively arranged at other boundaries of the light guiding part and the light focusing part. The other continuous parts are arranged to make the light guiding part and the light focusing part continuous, and the other discontinuous parts are arranged to separate the light guiding part and the light focusing part.

20. The light guide according to claim 19, wherein: The light collecting portion includes a light returning portion that returns the passing light having passed through the light guiding portion to the light guiding portion.

21. The light guide according to claim 20, wherein: The light-returning portion has another reflecting surface for reflecting the passing light toward the other continuous portion.

22. The light guide according to claim 21, wherein: The light-returning portion has a refractive surface configured to refract the passing light reflected by the other reflecting surface toward the other continuous portion.

23. The light guide according to claim 21 or 22, wherein: The light incident portion has a reflecting surface, and the reflecting surface is configured to reflect the light input from the light incident surface toward the continuous portion. The other reflecting surface of the light returning portion is arranged to be offset in the second direction with respect to the reflecting surface of the light incident portion.

24. The light guide according to any one of claims 21 to 22, wherein: The light incident portion has a reflecting surface, and the reflecting surface is configured to reflect the light input from the light incident surface toward the continuous portion. The other continuous portion and the other discontinuous portion are arranged such that in the second direction, the length of the other continuous portion is smaller than the length of the other discontinuous portion, The center of the other continuous portion is arranged to be offset in the second direction with respect to the other reflecting surface of the light returning portion and the reflecting surface of the light incident portion.

25. The light guide according to any one of claims 19 to 24, wherein: When viewed in the first direction, the continuous portion and at least a portion of the other non-continuous portion are disposed overlapping each other.

26. The light guide according to any one of claims 19 to 25, wherein: The other discontinuous portions are provided so that a separation distance between the light guiding portion and the light collecting portion is constant along the second direction.

27. The light guide according to any one of claims 1 to 26, wherein: The light incident portion includes a reflecting surface provided to reflect the light input from the light incident surface, and the reflecting surface is formed in a linear shape in a cross section including the first direction and the second direction.

28. The light guide according to any one of claims 1 to 26, wherein: The discontinuous portion is provided so that an end portion of the discontinuous portion on the light guide portion side extends obliquely with respect to the second direction.

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