Light guide

Abstract

A light guide 100 comprises: a light incident section 110 having a light input position 111a provided such that light S is inputted from a Z-axis direction; a light guide section 120 that guides light inputted into the light incident section in a Y-axis direction; and a light output section 130 having a light output position 131a provided such that light guided by the light guide section is outputted in the Z-axis direction, wherein the light guide section has a first light guide section 121 and a second light guide section 122 that are adjacent in a direction intersecting the Y-axis direction, a continuous section 143 provided at the boundary between the first light guide section and the second light guide section such that the first light guide section and the second light guide section are continuous, and a non-continuous section 144 provided at said boundary such that the first light guide section and the second light guide section are spaced apart. With this arrangement, light inputted into a light input section from the light input position can be guided efficiently through the light guide section to the light output section and outputted from the light output position of the light output section that is different from the light input position.

Description

Light guide

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

[0002] In recent years, in the fields of virtual reality (VR) technology and augmented reality (AR) technology, research and development has been progressing on head-mounted displays (HMDs) that are worn on the user's head and display three-dimensional images by displaying parallax images corresponding to each of the left and right eyes as virtual images, and head-up displays (HUDs) that project distant virtual images onto the windshield superimposed on the reality in front of the driver (see, for example, Patent Document 1). In these technologies, it is required to efficiently guide light containing image information such as parallax images and distant virtual images from a light source to a display unit such as the user's eyes or the windshield. Patent Document 1: JP 2020-118963 A General disclosure

[0003] (Item 1) A light guide that receives light from a light entrance position and outputs it from a light exit position different from the light entrance position may include a light entrance section having the light entrance position arranged so that the light is entered from a first direction. The light guide may include a light guide section that guides the light input to the light entrance section in a second direction intersecting the first direction. The light guide may include a light exit section having the light exit position arranged so that the light guided by the light guide section is output in a third direction intersecting the second direction. The light guide section may include a first light guide section and a second light guide section that are adjacent in a direction intersecting the second direction, and a continuous section at a boundary between the first light guide section and the second light guide section, where the first light guide section and the second light guide section are continuous, and a discontinuous section at a boundary between the first light guide section and the second light guide section, where the first light guide section and the second light guide section are spaced apart. (Item 2) The light entrance portion may include a first light entrance portion and a second light entrance portion adjacent to each other in a direction intersecting the second direction, and another continuous portion provided at a boundary between the first light entrance portion and the second light entrance portion so that the first light entrance portion and the second light entrance portion are continuous, and another discontinuous portion provided so that the first light entrance portion and the second light entrance portion are spaced apart. (Item 3) The light entrance portion may include a reflective surface provided to reflect the light input from the first direction at the light entrance position, toward the second direction. (Item 4) The light exit portion may include a first light exit portion and a second light exit portion adjacent to each other in a direction intersecting the second direction, and another continuous portion provided at a boundary between the first light exit portion and the second light exit portion so that the first light exit portion and the second light exit portion are continuous, and another discontinuous portion provided so that the first light exit portion and the second light exit portion are spaced apart. (Item 5) The light output unit may have another reflective surface arranged to reflect the light guided in the second direction by the light guide unit in the third direction. (Item 6) The light may include information. (Item 7) The information may be recorded information. (Item 8) The information may include at least one of a video and an image. (Item 9) The light may be light emitted from a light emission source. (Item 10) The light emission source may have a memory unit that stores the information. (Item 11) The light output unit may be installed in a wearing tool worn by a user.(Item 12) The light output unit may output the light toward a display unit that displays information. (Item 13) The output direction of the light at the light output position may be parallel to the input direction of the light at the light input position. (Item 14) The output direction of the light at the light output position may be anti-parallel to the input direction of the light at the light input position.

[0004] (Item 15) A wearing device worn by a user may include the light guide according to any one of items 1 to 10. The wearing device may include a light emitting source that emits the light.

[0005] (Item 16) A display device may include the light guide according to any one of items 1 to 10. The display device may include a light source that emits the light. The display device may include a display unit onto which the light output from the light guide is projected.

[0006] The above summary of the invention does not list all of the features of the present invention, and subcombinations of these features may also be inventions.

[0007] Shows the overall configuration of the light guide according to this embodiment. Shows the detailed configurations of the light incident portion and the boundary portion. Shows the overall configurations of the light incident portion, the light guide portion, the light exit portion, and the boundary portion. Shows the schematic configuration of the mounting tool and the light guiding of light within the light guide. Shows the mounted state of the mounting tool and the light guiding of light through the light guide. Shows the schematic configuration of the display device and the light guiding of light within the light guide. Shows the first manufacturing process flow of the light guide. Shows the state inside the mold after the mold and insert set process in the first manufacturing method in a front view (cross-section with respect to the reference line AA in FIG. 5B). Shows the state inside the mold after the mold and insert set process in the first manufacturing method in a side view (cross-section with respect to the reference line BB in FIG. 5A). Shows the resin flow in the molding process in the first manufacturing method. Shows the state of pulling out the insert in the insert pulling out process in the first manufacturing method. Shows the second manufacturing process flow of the light guide. Shows the state inside the mold after the first mold set process in the second manufacturing method in a front view. Shows the configurations of the first light incident portion, the first light guide portion, and the first light exit portion molded by the light incident portion molding process using the first mold in the second manufacturing method. Shows the configurations of the bottom surface and the continuous portion of the first light incident portion, the first light guide portion, and the first light exit portion. Shows the state inside the mold after the second mold and insert set process in the second manufacturing method in a front view. Shows the state inside the mold after the second mold and insert set process in the second manufacturing method in a perspective view. Shows the third manufacturing process flow of the light guide. Shows the configurations of the first light incident portion, the first light guide portion, and the first light exit portion molded by the light incident portion molding process in the third manufacturing method. Shows the configurations of the second light incident portion, the second light guide portion, and the second light exit portion molded by the light guide portion molding process in the third manufacturing method. Shows the state where the first light incident portion, the first light guide portion, and the first light exit portion are welded to the second light incident portion, the second light guide portion, and the second light exit portion by the welding process in the third manufacturing method.

[0008] Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. Also, not all combinations of features described in the embodiments are essential for the solution means of the invention.

[0009] 1A , 1B , and 1C respectively show the overall configuration of a light guide 100 according to this embodiment, the detailed configurations of a light entrance section 110 and a boundary section 140, and the overall configurations of the light entrance section 110, the light guide section 120, the light exit section 130, and the boundary section 140. The light guide 100 is an optical device that guides light input from a light entrance position 111 a of the light entrance section 110 to a light exit position 131 a different from the light entrance position 111 a without or with little leakage, and includes the light entrance section 110, the light guide section 120, the light exit section 130, and the boundary section 140. The light guide 100 as a whole has a generally plate-like shape that extends in two dimensions with the X-axis direction as its short side and the Y-axis direction as its long side, and has a thickness in the Z-axis direction. 1C and other drawings, the step portions on the −Y and +Z sides of the light entrance portion 110 and the step portions on the +Y and +Z sides of the light exit portion 130 are omitted from the illustration.

[0010] The light entrance section 110 has a light entrance position 111a provided so that light is entered from the Z-axis direction, is an optical member that collects light entered from the light entrance position 111a in the -Z direction, and has a first light entrance section 111 and a second light entrance section 112 adjacent to each other in the Z-axis direction, as well as a continuous section 141 and a discontinuous section 142 provided at the boundary between the first light entrance section 111 and the second light entrance section 112. In this embodiment, the first light entrance section 111 and the second light entrance section 112 are stacked integrally in the Z-axis direction.

[0011] The first light entrance section 111 is an upper portion of the light entrance section 110 where a light entrance position 111a is provided. The first light entrance section 111 has one or more (one in this embodiment) light-collecting elements 90. The light-collecting elements 90 are columnar members extending in the X-axis direction and having an inverted, approximately isosceles trapezoidal cross section with a maximum width P in the Y-axis direction and a height d in the Z-axis direction. They are arranged in parallel in the Y-axis direction with the +Z sides of their Y-side surfaces (i.e., the +Y side surface and the -Y side surface) in contact with each other and the -Z sides spaced apart from each other. In this embodiment, the multiple light-collecting elements 90 are integrally molded and connected to each other (however, for convenience of explaining the configuration and function of the light entrance section 110, the first light entrance section 111 will be described as including multiple light-collecting elements 90). As a result, the first light entrance section 111 extends in the Y-axis direction, the +Z faces of the multiple focusing elements 90 are connected to each other to form a planar light entrance surface having a width in the X-axis direction, and a light entrance position 111a is provided on the light entrance surface where light is input in the -Z direction.

[0012] Furthermore, two adjacent light-collecting elements 90 form between them a hollow space (simply referred to as a space) 140s that has a triangular cross section and extends in the X-axis direction.

[0013] The plurality of light-collecting elements 90 may be arranged in parallel and spaced apart from one another in the Y-axis direction. In such a case, the light entrance position 111a is provided on the +Z surface of one or some of the plurality of light-collecting elements 90.

[0014] The light-collecting element 90 has reflecting surfaces 92, 93 and a light-transmitting portion 94 located below (in the -Z direction) the light-entering position 111a. The light-collecting element 90 can be formed using, for example, a resin with a high refractive index, such as acrylic resin (refractive index 1.49) or polycarbonate resin (refractive index 1.58), or glass (for example, BK7 has a refractive index of 1.51 to 1.53). The boundary between the light-collecting element 90 and the space 140s, i.e., the ±Y side surfaces of the light-collecting element 90, function as reflecting surfaces 92, 93 that reflect a portion of the light input into the light-collecting element 90 from the Z-axis direction at the light-entering position 111a in the ±Y and -Z directions.

[0015] When light enters the ±Y side surfaces from inside the concentrating element 90 at an angle equal to or greater than the critical angle, it 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 concentrating element 90 are formed so that their normals form an angle equal to or greater than the critical angle with respect to the light input direction (the Z-axis direction in this embodiment). Meanwhile, the portion of the concentrating element 90 between the reflecting surfaces 92 and 93 functions as a light-transmitting portion 94 that transmits a portion of the light input from the light entrance position 111a (in this embodiment, the remaining portion that does not enter the reflecting surfaces 92 and 93) and the light reflected by the reflecting surfaces 92 and 93.

[0016] The reflecting surfaces 92 and 93 are positioned on the +Y and −Y sides of the light-transmitting portion 94, respectively, and are arranged opposite each other, so as to reflect the light input from the light-entering position 111a toward the light-transmitting portion 94. Here, the reflecting surfaces 92 and 93 are formed linearly on the YZ cross section. Furthermore, in order to increase the reflectivity, the reflecting surfaces 92 and 93, i.e., the ±Y side surfaces of the light-collecting element 90, may be mirror-finished. Furthermore, a reflective film may be provided using a metal or the like.

[0017] The second light entrance section 112 is a lower section of the light entrance section 110, and is a section that guides light reflected by the reflecting surfaces 92 and 93 of the first light entrance section 112 to the light guide section 120. The second light entrance section 112 is made of the same material as the first light entrance section 111 and is formed into a plate shape that extends in the X and Y directions and has a thickness in the Z axis direction.

[0018] The continuous portion 141 is provided so that the light-transmitting portion 94 of the first light entrance portion 111 and the second light entrance portion 112 are physically continuous with each other, and so that the light input from the light entrance position 111a, i.e., the reflected light reflected by the reflecting surfaces 92 and 93 (and the remaining light that did not enter the reflecting surfaces 92 and 93), is guided to the second light entrance portion 112. The continuous portion 141 has an opening width A in the Y-axis direction and extends in the X-axis direction. The continuous portion 141 can be made of the same material as the light-collecting element 90. The continuous portion 141 may also be formed integrally with the first light entrance portion 111 and / or the second light entrance portion 112 as part thereof.

[0019] The discontinuous portions 142 are provided so as to separate the reflective surfaces 92, 93 of the first light entrance portion 111 and the second light entrance portion 112, and are disposed adjacent to each of the ±Y sides of the continuous portion 141. The discontinuous portions 142 separate the second light entrance portion 112 from the first light entrance portion 111 (the reflective surfaces 92, 93 formed on the ±Y side surfaces), and a space 140s (for example, 140s ７ ), the interface between the discontinuous portion 142 and the second light entrance portion 112 functions as a reflective surface that reflects reflected light that is input from the light-transmitting portion 94 of the first light entrance portion 111 to the second light entrance portion 112 via the continuous portion 141 and guides it to the light-guiding portion 120. Note that, in order to increase the reflectivity, the interface between the discontinuous portion 142 and the second light entrance portion 112, i.e., the +Z end face of the second light entrance portion 112 below the space 140s, may be mirror-finished. Also, a reflective film may be provided using a metal or the like.

[0020] The light guiding section 120 is an optical member that guides light input to the light entrance section 110 in a direction (which is the Y-axis direction in this embodiment) that intersects (or is perpendicular or nearly perpendicular to) the Z-axis direction, and has a first light guiding section 121 and a second light guiding section 122 that are adjacent to each other in the Z-axis direction, as well as a continuous section 143 and a discontinuous section 144 that are provided at the boundary between the first light guiding section 121 and the second light guiding section 122. In this embodiment, the first light guiding section 121 and the second light guiding section 122 are integrally stacked in the Z-axis direction.

[0021] The first light guiding section 121 is an upper part of the light guiding section 120, and is formed by arranging a plurality of light condensing elements 90 in the Y-axis direction and integrally connecting them, similar to the first light entrance section 111. As a result, the first light guiding section 121 extends in the Y-axis direction, and a space 140s (for example, 140s) having a triangular cross section and extending in the X-axis direction is formed between two adjacent light condensing elements 90. ２ ~140s ６ The configurations of the light-collecting element 90 and the reflecting surfaces 92 and 93 are the same as those in the light entrance section 110 described above.

[0022] The second light guiding section 122 is a lower section of the light guiding section 120, and is a section that guides light that enters from the light entrance position 111 a of the light entrance section 110, is reflected by the reflecting surfaces 92 and 93 of the light entrance section 110, and is received via the second light entrance section 112, to the light exit section 130. The second light guiding section 122 is made of the same material as the first light guiding section 121 and is formed into a plate shape that extends in the X and Y directions and has a thickness in the Z axis direction.

[0023] Similar to the continuous portion 141 , the continuous portion 143 is provided so that the light-transmitting portion 94 of the first light guiding portion 121 and the second light guiding portion 122 are physically continuous with each other.

[0024] The discontinuous portions 144 are provided, similarly to the discontinuous portions 142, so as to separate the first light guiding portion 121 (the reflective surfaces 92, 93) and the second light guiding portion 122, and are disposed adjacent to each of the ±Y sides of the continuous portion 143. The discontinuous portions 144 separate the second light guiding portion 122 from the first light guiding portion 121 (the reflective surfaces 92, 93 formed on the ±Y side surfaces), and a space 140s (140s ２ ~140s ６), the interface between the discontinuous portion 144 and the second light guiding portion 122 functions as a reflective surface that reflects light that has entered from the light entrance portion 120 (second light entrance portion 112) and guides it to the light exit portion 130. Note that, in order to increase the reflectivity, the interface between the discontinuous portion 144 and the second light guiding portion 122, i.e., the +Z end face of the second light guiding portion 122 below the space 140s, may be mirror-finished. Also, a reflective film may be provided using a metal or the like.

[0025] The light output section 130 is an optical member having a light output position 131a arranged so that light guided by the light guide section 120 is output in a direction (in this embodiment, the Z-axis direction) that intersects (or is perpendicular or nearly perpendicular to) the Y-axis direction, and outputs light from the light output position 131a in the +Z direction, and has a first light output section 131 and a second light output section 132 that are adjacent in the Z-axis direction, as well as a continuous section 145 and a discontinuous section 146 that are provided at the boundary between the first light output section 131 and the second light output section 132. In this embodiment, the first light output section 131 and the second light output section 132 are stacked integrally in the Z-axis direction.

[0026] The first light exit section 131 is the upper portion of the light exit section 130, and like the first light entrance section 111, is formed by arranging one or more (one in this embodiment) focusing elements 90 in the Y-axis direction and integrally connecting them. As a result, the first light exit section 131 extends in the Y-axis direction, and its +Z surface extends in the XY direction to form a planar light exit surface, and a light exit position 131a is provided on the light exit surface where light is output in the +Z direction. The focusing element 90 has reflective surfaces 92, 93 and a light-transmitting portion 94 located below (in the -Z direction) the light exit position 131a. Furthermore, a space 140s having a triangular cross section and extending in the X-axis direction is formed between two adjacent focusing elements 90. The configurations of the focusing elements 90 and the reflective surfaces 92, 93 are the same as those of the light entrance section 110 described above. These reflecting surfaces 92 and 93 reflect the light guided in the Y-axis direction by the light guide section 120 in the Z-axis direction.

[0027] The second light output section 132 is a lower portion of the light output section 130, and is a section that sends light guided via the light guide section 120 (second light guide section 122) to the first light output section 131. The second light output section 132 is made of the same material as the first light output section 131 and is formed into a plate shape that extends in the X and Y directions and has a thickness in the Z axis direction. The light sent by the second light output section 132 to the first light output section 131 is reflected by the reflecting surfaces 92 and 93 of the first light output section 131 and is output in the Z axis direction from a light output position 131 a of the light output section 130.

[0028] Similar to the continuous portion 141 , the continuous portion 145 is provided so that the light-transmitting portion 94 of the first light output portion 131 and the second light output portion 132 are physically continuous with each other.

[0029] The discontinuous portions 146 are provided, similarly to the discontinuous portions 142, so as to separate the first light output portion 131 (reflecting surfaces 92, 93) and the second light output portion 132, and are disposed adjacent to each of the ±Y sides of the continuous portion 145. The discontinuous portions 146 separate the second light output portion 132 from the first light output portion 131 (reflecting surfaces 92, 93 formed on the ±Y side surfaces), and a space 140s (for example, 140s ７ ), the interface between the discontinuous portion 146 and the second light output portion 132 functions as a reflective surface that reflects light transmitted from the second light guide portion 122 through the continuous portion 145 from the light transmitting portion 94 of the first light output portion 131 and guides the light to the first light output portion 131. Note that, in order to increase the reflectivity, the interface between the discontinuous portion 146 and the second light output portion 132, i.e., the +Z end face of the second light output portion 132 below the space 140s, may be mirror-finished. Also, a reflective film may be provided using a metal or the like.

[0030] The boundary portion 140 is a portion located at the boundary between the first light entrance portion 111, the first light guide portion 121, and the first light exit portion 131 and the second light entrance portion 112, the second light guide portion 122, and the second light exit portion 132, and includes the aforementioned continuous portions 141, 143, 145 and discontinuous portions 142, 144, 146.

[0031] In the light guide 100 according to this embodiment, the first light entrance section 111, the first light guide section 121, and the first light exit section 131 are arranged in the Y-axis direction and integrally molded. These integrally molded sections are also referred to as the upper section 101. The second light entrance section 112, the second light guide section 122, and the second light exit section 132 are arranged in the Y-axis direction and integrally molded. These integrally molded sections are also referred to as the lower section 102. In other words, the light entrance section 110, the light guide section 120, and the light exit section 130 are arranged in the Y-axis direction and integrally molded.

[0032] In this embodiment, the reflective surfaces 92, 93 and the light-transmitting portions 94 of the light entrance portion 110, the light guide portion 120, and the light exit portion 130 are arranged in multiple numbers along the Y-axis direction in the upper stage portion 101 of the light guide body 100 by arranging the light-collecting elements 90 in parallel in the Y-axis direction and integrally forming them. Accordingly, one or more continuous portions 141, 143, 145 and discontinuous portions 142, 144, 146 are provided at the boundaries between the first light entrance portion 111, the first light guide portion 121, and the first light exit portion 131 and the second light entrance portion 112, the second light guide portion 122, and the second light exit portion 132, and the multiple continuous portions 141, 143, 145 and the multiple discontinuous portions 142, 144, 146 are alternately arranged along the Y-axis direction. Here, the continuous portions 141, 143, and 145 have a width A in the Y-axis direction (equal to the width of the light-transmitting portion 94) and are periodically arranged at a pitch P in the Y-axis direction. In this embodiment, the discontinuous portions 142, 144, and 146 have widths approximately equal to those of the continuous portions 141, 143, and 145 and are arranged between the continuous portions 141, 143, and 145. This results in an aperture ratio A / P of approximately 1 / 2. Note that the continuous portions 141, 143, and 145 and the adjacent discontinuous portions 142, 144, and 146 may have different widths in the Y-axis direction, and the aperture ratio A / P may be greater than or less than approximately 1 / 2.

[0033] 1B , the reflecting surfaces 92 and 93 of the light entrance unit 110 reflect light input from the light entrance position 111a toward the second light entrance unit 112. In particular, the reflecting surfaces 92 and 93 reflect light input from a direction (in this embodiment, the Z-axis direction) that intersects (or is perpendicular or nearly perpendicular to) the light entrance surface (the +Z surface of the first light entrance unit 111) to which the light entrance position 111a belongs, toward the second light entrance unit 112. Here, the light reflected by the reflecting surface 93 forms parallel light and passes through the continuous portion 141. That is, the light reflected at the +Z side of the reflecting surface 93 passes through the +Y side of the continuous portion 141, the light reflected at the center of the reflecting surface 93 passes through the center of the continuous portion 141, and the light reflected at the −Z side of the reflecting surface 93 passes through the −Y side of the continuous portion 141, and then enters the second light entrance unit 112. The light reflected by the reflecting surface 92 forms parallel light and enters the second light entrance section 112 in the same manner as the light reflected by the reflecting surface 93, except that the light travels in the opposite direction.

[0034] The reflecting surfaces 92 and 93 of the light output unit 130 reflect the light transmitted through the light guide unit 120 and the second light output unit 132 and output the light from the light output position 131a of the light output unit 130. In particular, the reflecting surfaces 92 and 93 reflect the light transmitted through the light guide unit 120 and the second light output unit 132 and output the light in a direction (in this embodiment, the Z-axis direction) intersecting (or perpendicular or substantially perpendicular) the light output surface (the +Z surface of the first light output unit 131) to which the light output position 131a belongs. Here, the light transmitted from the second light output unit 132 forms parallel light, passes through the continuous portion 145, enters the reflecting surface 92, is reflected, and is output from the light output position 131a in the +Z direction. The light reflected by the reflecting surface 93 forms parallel light similar to the light reflected by the reflecting surface 92, except that the light enters in the opposite direction, and is output from the light output position 131a.

[0035] Note that the discontinuous portion 142 is disposed below the reflecting surfaces 92, 93 of the light entrance portion 110, and thus includes a discontinuous portion 142b separating the reflecting surface 92 and the second light entrance portion 112, and a discontinuous portion 142a separating the reflecting surface 93 and the second light entrance portion 112. Furthermore, by arranging the plurality of focusing elements 90 in parallel in the Y-axis direction within the light entrance portion 110, a space 140s having a triangular cross section as viewed in the Y-direction is formed therein by the Y-side surfaces of two adjacent focusing elements 90 and the discontinuous portion 142 (the +Z end portions of the second light entrance portions 112), and the reflecting surfaces 92, 93 of the two adjacent focusing elements 90 face each other via the space 140s, and the discontinuous portions 142 located below each other are continuous.

[0036] Furthermore, the end of the discontinuous portion 142 on the second light entrance portion 112 side (i.e., the interface between the second light entrance portion 112 and the discontinuous portion 142) may be inclined with respect to the Y-axis direction. Here, the interfaces between the second light entrance portion 112 and each of the adjacent discontinuous portions 142 may be inclined in different directions with respect to the Y-axis direction. The interface between the second light entrance portion 112 and the discontinuous portion 142a may be inclined in a clockwise direction with respect to the Y-axis, and the interface between the second light entrance portion 112 and the discontinuous portion 142b may be inclined in a counterclockwise direction with respect to the Y-axis. The discontinuous portions 142 arranged in the Y-axis direction may include discontinuous portions 142a and 142b arranged alternately.

[0037] Furthermore, the opposing reflecting surfaces 92, 93 of one focusing element 90 have the same inclination angle and in opposite directions relative to the Z axis. The inclination angles may be different for each of the adjacent focusing elements 90, or may alternate. The reflecting surfaces 92, 93 facing each other across a space 140s between two adjacent focusing elements 90 have different inclination angles. The triangular cross sections of the multiple spaces 140s arranged in the Y-axis direction may be rotated alternately in different directions. Here, the rotation of the multiple spaces 140s refers to rotation around a reference axis parallel to the X-axis direction that passes through the center of the space 140s on the YZ plane. In this example, the left space 140sa is rotated clockwise and the right space 140sb is rotated counterclockwise relative to the pre-rotation state 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). As a result, the spaces 140sa rotated clockwise and the spaces 140sb rotated counterclockwise are arranged alternately in the Y-axis direction.

[0038] When the plurality of spaces 140s are not rotated, the boundary 140 forms a straight line extending in the Y-axis direction in the YZ plane, and the continuous portion 141 and the discontinuous portion 142 are also linearly continuous in the YZ plane. When the plurality of spaces 140s are rotated, the boundary 140 is repeatedly bent in the ±Z directions in the YZ plane to form a non-linear line extending in the Y-axis direction, and the continuous portion 141 and the discontinuous portion 142 are also linearly continuous in the YZ plane.

[0039] The same applies to the reflective surfaces 92, 93 and space 140s of the light-guiding section 120 and the light-emitting section 130, the continuous section 143 and discontinuous section 144 between the first light-guiding section 121 and the second light-guiding section 122, and the continuous section 145 and discontinuous section 146 between the first light-emitting section 131 and the second light-emitting section 132.

[0040] 2A shows a schematic configuration of the wearing device 200 according to this embodiment and the guiding of light S within the light guide 100. The wearing device 200 is, for example, a head-mounted display (HMD) worn on the head of a user, and includes the light guide 100 and a light source 180. The light guide 100 is configured as described above.

[0041] The light source 180 is a device that emits light and includes a light source 181, a storage unit 182, and an optical system 183. The light source 181 is a device that generates light. The light includes information of at least one of a video and an image. The storage unit 182 is a storage device that stores information. The optical system 183 includes an optical element such as a lens element that sends the light generated by the light source 181 in the +Z direction toward the light entrance position 111a of the light guide 100.

[0042] 2B shows the wearing state of the wearing device 200 and the guidance of light through the light guide 100. When a user wears the wearing device 200 on their head (not shown), the light output position 131a of the light guide 100 is positioned in front of the eyes, and the light source 180 is positioned next to the head. When the wearing device 200 is activated, the light source 180 reads information recorded in the memory unit 182 and activates the light source 181 in accordance with the information to generate light containing at least one of video and image information, which is input to the light input position 111a of the light guide 100 in the -Z direction via the optical system 183.

[0043] 2A, light S output from light source 180 and entering in the -Z direction from light entrance position 111a enters reflecting surface 93 of light entrance section 110. Light S is reflected by reflecting surface 93 toward light-transmitting section 94, enters second light entrance section 112 through continuous section 141, and is guided toward the +Y direction to light guide section 120. Within light guide section 120, light S is reflected by the -Z surface of second light guide section 122 and directed in the +Z direction, and is then guided between second light guide section 122 and space 140s. ４ The light S is reflected at the boundary between the second light guide portion 122 and the discontinuous portion 144 located on the -Z side of the second light guide portion 122, directed in the -Z direction, and then reflected again at the -Z surface of the second light guide portion 122, directed in the +Z direction, and guided to the second light output portion 132. In this manner, the light S is guided in the +Y direction (the direction of the arrow in FIG. 2B ) within the light output portion 130. Within the light output portion 130, the light S is guided from the second light output portion 132 through the continuous portion 145 to the first light output portion 131, reflected by the reflective surface 92 toward the light output surface (the +Z surface of the first light output portion 131), and output from the light output position 131a anti-parallel (opposite) to the input direction of the light S at the light input position 111a, i.e., in the +Z direction. The light S output from the light output position 131a enters the user's eye E. This allows the user to view a video or image represented by the light.

[0044] The inclination angle of the discontinuous portion 144 and / or the inclination angles of the reflecting surfaces 92, 93 are determined so that the light S that has entered the second light guiding portion 122 does not leak into the first light guiding portion 121 via the continuous portion 143. Furthermore, the light S is not limited to being input to the light entrance position 111a in the -Z direction, but may be input at an angle with respect to the Z axis, and is not limited to being output from the light exit position 131a in the +Z direction, but may be output at an angle with respect to the Z axis. In such cases, the output direction of the light S at the light exit position 131a is opposite to the input direction of the light S at the light entrance position 111a in the Z axis direction.

[0045] Although the wearing device 200 according to this embodiment is a wearing device for one eye, it may be a wearing device for both eyes that includes two wearing devices 200 .

[0046] 3 shows a schematic configuration of the display device 210 and the guiding of light S within the light guide 100. The display device 210 is, for example, a head-up display (HUD) mounted in front of the driver's seat of a passenger vehicle, and includes the light guide 100, a light source 180, and a display unit 190.

[0047] The light guide 100 is configured as described above. However, the space 140s between the first light guide 121 and the second light guide 122 is ４ is rotated slightly counterclockwise. This allows the second light guide 122 and the space 140s ４ The light reflected at the interface between the first light output portion 131 and the second light output portion 132 is guided through the second light guide portion 122 at a smaller angle with respect to the Y-axis direction. ７ is rotated approximately 90 degrees counterclockwise. As a result, light exit position 132a is provided on the −Z plane of second light exit portion 132, and light S that enters first light exit portion 131 from second light exit portion 132 via continuous portion 145 is reflected by reflective surface 92 and directed in the −Z direction, and is output from light exit position 132a via second light exit portion 132 toward display unit 190 in the −Z direction.

[0048] The light source 180 is configured in the same manner as that in the wearing tool 200 described above.

[0049] The display unit 190 is a display device that displays at least one of video and image information, such as on the front window of an automobile, and has a display surface 191 and an optical system 192. The display surface 191 is one surface of the front window or the like onto which the light S is projected. The optical system 192 includes an optical element, such as a lens element, that sends the light output from the light guide 100 toward the display surface 191 in the −Z direction.

[0050] In the display device 210, light S output from the light source 180 and entering in the -Z direction from the light entrance position 111a enters the reflecting surface 93 of the light entrance section 110. The light S is reflected by the reflecting surface 93 toward the light transmitting section 94, enters the second light entrance section 112 through the continuous section 141, and is guided toward the +Y direction to the light guiding section 120. Within the light guiding section 120, the light S is reflected by the -Z surface of the second light guiding section 122 and directed in the +Z direction, and passes through the second light guiding section 122 and the space 140s. ４ The light S is reflected at the boundary between the second light guide portion 122 and the discontinuous portion 144 located on the -Z side of the second light guide portion 122, directed in the -Z direction, and then reflected again at the -Z surface of the second light guide portion 122, directed in the +Z direction, and guided to the second light output portion 132. In this way, the light S is guided in the +Y direction within the light guide portion 120. Within the light output portion 130, the light S is guided from the second light output portion 132 through the continuous portion 145 to the first light output portion 131, reflected by the reflective surface 92 and directed in the -Z direction, and reflected by the reflective surface 92 toward the light output surface (in this example, the -Z surface of the second light output portion 132), and output from the second light output portion 132 through the light output position 132a parallel to (the same direction as) the input direction of the light S at the light input position 111a, i.e., in the -Z direction. The light S output from the light output position 131a is projected onto the display surface 191 via the optical system 192 of the display unit 190. This allows the user to view the video or image projected on the display surface 191 .

[0051] The inclination angle of the discontinuous portion 144 and / or the inclination angles of the reflecting surfaces 92, 93 are determined so that the light S that has entered the second light guiding portion 122 does not leak into the first light guiding portion 121 via the continuous portion 143. Furthermore, the light S is not limited to being input to the light entrance position 111a in the -Z direction, but may be input at an angle with respect to the Z axis, and is not limited to being output from the light exit position 132a in the -Z direction, but may be output at an angle with respect to the Z axis. In such cases, the output direction of the light S at the light exit position 132a is opposite to the input direction of the light S at the light entrance position 111a in the Z axis direction.

[0052] 4 shows a first manufacturing method flow S100 for the light guide 100. In this embodiment, as an example, acrylic resin is used as the molding material for the light guide 100. In other words, the light entrance section 110, the light guide section 120, and the light exit section 130 are made of the same material.

[0053] In step S101, molds 151 and 152 and multiple inserts 153 are set. Figures 5A and 5B show the interiors of molds 151 and 152 as viewed from the front (along reference line AA in Figure 5B ) and from the side (along reference line BB in Figure 5A ), respectively. Mold 151 is a metal mold for forming first light entrance portion 111, first light guide portion 121, and first light exit portion 131 (i.e., upper portion 101 of light guide body 100), and includes an internal space sized and shaped to accommodate upper portion 101 and multiple inserts 153. Mold 152 is a metal mold for forming second light entrance portion 112, second light guide portion 122, and second light exit portion 132 (i.e., lower portion 102 of light guide body 100), and includes an internal space sized and shaped to accommodate lower portion 102. The plurality of inserts 153 are metal molds for forming spaces 140s in the upper stage 101 (between the plurality of light-collecting elements 90), and are solid pillars having a substantially isosceles triangular cross section.

[0054] The mold 152 is placed with its internal space facing the +Z direction, multiple nesting pieces 153 are arranged on the mold 152 in the Y-axis direction so as to straddle the internal space of the mold 152 in the X-axis direction, and the mold 151 is placed over the mold 152 with its internal space facing the -Z direction. As a result, an internal space 140s is formed between the molds 151 and 152, separated vertically by the multiple nesting pieces 153 except for a portion.

[0055] In step S102, acrylic resin is injected into the molds 151 and 152 to form the light guide 100. Fig. 5C shows the flow of resin inside the molds 151 and 152. The resin is injected downward through a through-hole (not shown) in the mold 152, and while filling in the direction of the black arrow, it also fills upward through the gaps between the multiple inserts 153. After a certain time has passed and the resin has cooled, the process moves to the next step.

[0056] In step S103, the mold 151 is pulled in the +Z direction to open the mold, thereby exposing the upper portion 101 on the mold 152 with the lower portion 102 fitted into the internal space of the mold 152, as shown in FIG.

[0057] In step S104, the plurality of core dies 153 are pulled out. Fig. 5D shows the state in which the plurality of core dies 153 are pulled out from the light guide 100. The plurality of core dies 153 are pulled out in the direction of the outline arrow (+X direction). Note that the plurality of core dies 153 may be formed in a tapered shape in which the +X end is narrower than the -X end, so that they can be easily pulled out from the light guide 100.

[0058] In step S105, the light guide 100 is removed from the mold 152. This results in the light guide 100 shown in FIG. 1A.

[0059] In step S106, the molds 151 and 152 and the plurality of inserts 153 are cleaned, and the flow then ends. By repeating steps S101 to S106, a plurality of light guide bodies 100 can be manufactured.

[0060] 6 shows a second manufacturing method flow S200 for the light guide 100. In this embodiment, as an example, acrylic resin is used as the molding material for the light guide 100. In other words, the upper and lower portions 101 and 102 are formed from the same material.

[0061] In step S201, molds 161 and 162 are set. FIG. 7A shows the interior of molds 161 and 162 as viewed from the front (as viewed in the X-axis direction). Molds 161 and 162 are a pair of metal dies for forming upper stage portion 101. Mold 161 includes an internal space having a size and shape capable of accommodating upper stage portion 101. Mold 162 has multiple protruding edges 162a that protrude from the top surface in the +Z direction and are aligned in the Y-axis direction. The multiple protruding edges 162a are structured to form spaces 140s in upper stage portion 101 (between multiple focusing elements 90), and are formed to have a substantially isosceles triangular cross-sectional shape extending in the X-axis direction.

[0062] The mold 162 is placed with its multiple protruding sides 162a facing in the +Z direction, and the mold 161 is placed over the mold 162 with its internal space facing in the -Z direction to accommodate the protruding sides 162a. This forms an internal space 161s between the molds 161 and 162.

[0063] In step S202, acrylic resin is injected into molds 161 and 162 to mold upper stage portion 101. FIGS. 7B and 7C respectively show the overall configuration and the structure on the -Z side of molded upper stage portion 101. As described above, upper stage portion 101 is integrally molded such that multiple condensing elements 90 are arranged side by side in the Y-axis direction, and spaces 140s are included between adjacent condensing elements 90. Continuous portions 141, 143, and 145 are formed on the -Z surface of each condensing element 90. In other words, in this example, continuous portions 141, 143, and 145 are integrally molded with upper stage portion 101. The detailed configurations of continuous portions 141, 143, and 145 are as described above.

[0064] In step S203, the mold 162 is opened from the mold 161. In this state, the upper portion 101 is housed in the mold 161.

[0065] In step S204, the molds 161, 163 and the plurality of inserts 165 are set. Figures 7D and 7E show the interiors of the molds 161, 163 in a front view (viewed in the X-axis direction) and a perspective view, respectively. The mold 163 is configured similarly to the mold 152 described above. The plurality of inserts 165 are configured similarly to the insert 153 described above, except that their length is equal to the width of the upper stage 101 in the X-axis direction.

[0066] The mold 161 containing the light entrance portion 110 is turned upside down, and the cores 165 are inserted into the plurality of spaces 140s of the upper portion 101, and the mold 163 is placed over the mold 161 with its internal space facing the -Z direction. As a result, the upper portion 101 with the plurality of cores 165 fitted into the spaces 140s is contained in the internal space of the mold 161, and an internal space 163s is formed between the mold 161 and the mold 163.

[0067] In step S205, acrylic resin is injected into the molds 161 and 163 to mold the light guide 100 by insert molding. The resin is injected into the internal space 163s through a through-hole (not shown) in the mold 163 and fills the +Z side of the upper stage portion 101. When the resin cools after a certain period of time has passed, the resin forms the lower stage portion 102 and is integrated with the upper stage portion 101 via the connecting portions 141, 143, and 145 (see FIG. 7C ).

[0068] In step S206, the light guide 100 is removed from the molds 161 and 163, and the plurality of core dies 165 are also pulled out from the light guide 100. Note that the plurality of core dies 165 may be formed in a tapered shape such that the +X end is narrower than the −X end, so that the core dies 165 can be easily pulled out from the light guide 100. In this way, the light guide 100 shown in FIG. 1A is obtained.

[0069] In step S207, the molds 161, 162, and 163 and the plurality of inserts 165 are cleaned, and the flow then ends. By repeating steps S201 to S207, a plurality of light guides 100 can be manufactured.

[0070] 8 shows a third manufacturing flow S300 of the light guide 100. In this embodiment, as an example, acrylic resin is used as the molding material for the light guide 100. In other words, the upper and lower portions 101 and 102 are formed from the same material.

[0071] In step S302, the upper stage portion 101 is molded. The upper stage portion 101 can be molded by the above-described steps S201 to S203. Fig. 9A shows the structure of the molded upper stage portion 101. The upper stage portion 101 is formed as a separate body from the lower stage portion 102.

[0072] In step S304, the lower stage portion 102 is molded. Details of the molding are omitted. Fig. 9B shows the configuration of the molded lower stage portion 102. The lower stage portion 102 is formed as a separate body from the upper stage portion 101.

[0073] In step S306, the upper and lower portions 101 and 102 are welded together to form the light guide 100. As shown in FIG. 9C , the upper portion 101 is placed on the +Z end face of the lower portion 102, with one end face where the space 140s is formed facing the -Z side. This causes the -Z face of the upper portion 101 to abut against the +Z end face of the lower portion 102. In this state, ultrasonic vibrations are applied to the upper and / or lower portion 102 to weld them together. This bonds the upper and lower portions 101 and 102 together via the continuous portions 141, 143, and 145, forming the light guide 100.

[0074] Before applying ultrasonic vibrations to the upper and / or lower portions 101 and 102, the portions to be welded may be preheated, for example, by irradiating them with infrared rays, and then the upper and lower portions 101 and 102 may be brought into contact with each other, and vibrations may be applied in a direction parallel to the contacting surfaces while applying pressure in the contacting direction to generate frictional heat, thereby welding the upper and lower portions 101 and 102 together. This allows for welding without air entrapment and with reduced beads.

[0075] The upper and lower portions 101, 102 may be bonded together by other means than welding, such as using a solvent. For example, the upper and lower portions 101, 102 may be bonded together by providing a small gap between them, pouring a photocurable adhesive into the gap by capillary force, and curing the photocurable adhesive by irradiating it with light. Alternatively, the upper and lower portions 101, 102 may be bonded together using optical tape (e.g., ACO04N by 3M). Alternatively, the light guide 100 may be molded using a 3D printer.

[0076] The light guide 100 of this embodiment includes a light entrance section 110 having a light entrance position 111a arranged so that light S is input from the Z-axis direction, a light guide section 120 that guides the light input to the light entrance section 110 in the Y-axis direction, and a light exit section 130 having a light exit position 131a arranged so that the light guided by the light guide section 120 is output in the Z-axis direction, and the light guide section 120 has a first light guide section 121 and a second light guide section 122 that are adjacent in a direction intersecting (or perpendicular or nearly perpendicular to) the Y-axis direction, a continuous section 143 arranged at the boundary between the first light guide section 121 and the second light guide section 122 so that the first light guide section 121 and the second light guide section 122 are continuous, and a discontinuous section 144 arranged so that the first light guide section 121 and the second light guide section 122 are spaced apart. This allows light S input to the light entrance section 110 from the light entrance position 111a to be efficiently guided to the light exit section 130 via the light guide section 120, and output from light exit positions 131a, 132a of the light exit section 130 that are different from the light entrance position 111a.

[0077] The wearing device 200 according to this embodiment includes a light guide 100 and a light emission source 180 that emits light. This allows the light generated from the light emission source 180 to be efficiently transmitted to the user's eyes via the light guide 100.

[0078] The display device 210 according to the present embodiment includes a light guide 100, a light source 180 that emits light, and a display unit 190 onto which the light output from the light guide 100 is projected. Thus, the light generated from the light source 180 is sent to the display unit 190 via the light guide 100, and information such as a video or an image can be projected by the light.

[0079] Note that, instead of the hollow space having a triangular cross section in front view, the space 140s within the light guiding unit 120 may be a hollow space having a rectangular cross section in front view that separates the entire first light guiding unit 121 and the entire second light guiding unit 122. This allows the entire +Z surface of the second light guiding unit 122 to function as a reflective surface.

[0080] The upper surface (+Z surface) and the lower surface (-Z surface) of the light guide 100 according to this embodiment may be smooth, which can prevent the accumulation of dust and other particles when the light guide 100 is installed outdoors.

[0081] In the light guide 100 according to the present embodiment, the light guide section 120 is formed in a plate shape extending in the Y-axis direction perpendicular to the light input direction (Z-axis direction). However, the present invention is not limited to this, and the light guide section 120 may be curved in any direction intersecting the light input direction, such as curved in an arc or spherical shell shape. The light guide section 120 may be curved or bent in any direction from the portion connecting to the light entrance section 110, or may be formed to extend to the light exit section 130 by widening or narrowing, or increasing or decreasing its thickness. As a result, light collected by the light entrance section 110 is guided into the light guide section 120 and then reflected by its end surface and guided in any direction toward the light exit section 130.

[0082] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0083] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order.

[0084] 90...light-collecting element, 92, 93...reflecting surfaces, 94...light-transmitting portion, 100...light guide, 101...upper portion, 102...lower portion, 110...light entrance portion, 111...first light entrance portion, 111a...light entrance position, 112...second light entrance portion, 120...light guide portion, 121...first light guide portion, 122...second light guide portion, 130...light exit portion, 131...first light exit portion, 131a, 132a...light exit position, 132...second light exit portion, 140...boundary portion, 140s, 140sa, 140sb, 140s １ ~140s ７ ...internal space (space), 141, 143, 145...continuous portion, 142, 142a, 142b, 144, 146...discontinuous portion, 151, 152...mold, 153...nested, 161, 162, 163...mold, 161s...internal space, 162, 163...mold, 162a...protruding edge, 163s...internal space, 165...nested, 180...light-emitting source, 181...light source, 182...memory unit, 183...optical system, 190...display unit, 191...display surface, 192...optical system, 200...mounting device, 210...display device, E...eye, S...light.

Claims

1. A light guide that outputs light input from a light entrance position from a light exit position different from the light entrance position, a light entrance portion having the light entrance position provided so that the light is input from a first direction; a light guide portion that guides the light input to the light input portion in a second direction that intersects with the first direction; a light output section having the light output position provided so that the light guided by the light guide section is output in a third direction intersecting the second direction, the light guiding section includes a first light guiding section and a second light guiding section adjacent to each other in a direction intersecting the second direction, and a continuous section provided at a boundary between the first light guiding section and the second light guiding section so that the first light guiding section and the second light guiding section are physically continuous with each other, and a discontinuous section provided so that the first light guiding section and the second light guiding section are spaced apart from each other, and the first light guiding section and the second light guiding section are integrally stacked in the intersecting direction via the continuous section. Light guide.

2. The light guide of claim 1, wherein the light entrance portion has a first light entrance portion and a second light entrance portion adjacent to each other in a direction intersecting the second direction, and another continuous portion at the boundary between the first light entrance portion and the second light entrance portion so that the first light entrance portion and the second light entrance portion are physically continuous, and another discontinuous portion at the boundary between the first light entrance portion and the second light entrance portion so that the first light entrance portion and the second light entrance portion are spaced apart.

3. 3. The light guide of claim 2, wherein the light entrance portion has a reflective surface configured to reflect the light input from the first direction at the light entrance position in the second direction, and the reflective surface is formed at the boundary between the first light entrance portion and a hollow space formed within the light entrance portion.

4. 2. The light guide of claim 1, wherein the light exit portion has a first light exit portion and a second light exit portion adjacent to each other in a direction intersecting the second direction, and a further continuous portion at the boundary between the first light exit portion and the second light exit portion such that the first light exit portion and the second light exit portion are physically continuous, and a further discontinuous portion at the boundary between the first light exit portion and the second light exit portion such that the first light exit portion and the second light exit portion are spaced apart.

5. 5. The light guide of claim 4, wherein the light exit section has another reflective surface arranged to reflect the light guided in the second direction by the light guide section in the third direction, and the other reflective surface is formed at the boundary between the first light exit section and a hollow space formed within the light exit section.

6. The light guide of claim 1 , wherein the light contains information.

7. The light guide of claim 6 , wherein the information is recorded information.

8. The light guide of claim 6 , wherein the information includes at least one of a video and an image.

9. The light guide of claim 6 , wherein the light is emitted from a light source.

10. The light guide according to claim 9 , wherein the light source has a storage unit for storing the information.

11. The light guide of claim 1 , which is mounted in a wearable device worn by a user.

12. The light guide according to claim 1 , wherein the light output section outputs the light toward a display section that displays information.

13. The light guide of claim 1 , wherein the light output direction at the light output position is parallel to the light input direction at the light input position.

14. 14. A light guide according to any preceding claim, wherein the light output direction at the light output position is anti-parallel to the light input direction at the light input position.

15. A wearing device to be worn by a user, A light guide according to any one of claims 1 to 10; a light source that emits the light; A wearing device comprising:

16. A light guide according to any one of claims 1 to 10; a light source that emits the light; a display unit onto which light output from the light guide is projected; A display device comprising: