JP6355041B2 - Light guide member and light guide member manufacturing method - Google Patents

Description

  The present invention relates to a light guide member and a method for manufacturing the light guide member. More specifically, the present invention relates to a light guide member in which a diffusion groove is formed in order to diffuse light incident on the light guide member and a method for manufacturing the light guide member.

  2. Description of the Related Art Conventionally, a light guide member having a light incident surface on which light emitted from a light source is incident, a reflection surface on which light incident from the light incident surface is reflected, and a light output surface on which light reflected on the reflection surface is emitted are known. (See, for example, Patent Document 1).

JP 2012-174445 A

  In the invention described in Patent Document 1, a plurality of diffusion grooves for diffusing light are formed on the reflection surface, and a flat surface is provided between each diffusion groove. The diffusion grooves were formed in a triangular shape by cutting, and all the diffusion grooves had the same shape. Therefore, the diffusion direction of light reaching the diffusion groove is the same in any diffusion groove.

  The present invention was invented in view of the above-described conventional problems, and the object of the present invention is to provide a light guide member and a method for manufacturing the light guide member that can improve the diffusibility in a plurality of diffusion grooves. It is a problem to provide.

  In order to solve the above problems, the present invention has the following configuration.

A rod-shaped light guide member manufactured by processing an extruded product formed by extrusion molding, which is one end surface in the longitudinal direction of the light guide member, and a first end surface on which light from a light source is incident And a second end face that is the other end face in the longitudinal direction of the light guide member and is disposed at a position opposite to the first end face, and the first end face provided along the longitudinal direction. And a light exit surface from which the light reflected along the longitudinal direction is emitted, and the light exit surface is located at a position opposite to the reflection surface. The reflection surface has a plurality of diffusion grooves for diffusing light, formed by laser irradiation, and a flat surface provided in a portion other than the diffusion groove, and the reflection surface includes the A plurality of shape change regions arranged in the longitudinal direction, each shape change region is The plurality of diffusion grooves arranged in the longitudinal direction and having different cross-sectional shapes from each other, and the plurality of diffusion grooves in each of the shape change regions include the side surface on the first end face side of the diffusion groove and the flat surface Are regularly decreased or increased in the direction from the first end face toward the second end face, and the second end face from the first end face within each shape change region. The change in the cross-sectional shape of the diffusion groove in the direction toward is similar.

The length direction of the diffusion groove is inclined with respect to the direction from the first end surface toward the second end surface and the direction orthogonal to the direction from the reflection surface toward the light exit surface. Is preferred.

Further, both end surfaces of the first end surface and the second end surface become light incident surfaces on which light from the light source is incident, and the interval between the diffusion grooves is from the center in the longitudinal direction of the reflection surface, It is preferable that the width becomes wider toward the first end face side and becomes wider toward the second end face side.

Further, both end surfaces of the first end surface and the second end surface are light incident surfaces on which light from the light source is incident, and the length of the diffusion groove is from the center in the longitudinal direction of the reflection surface, It is preferable that the length becomes shorter toward the first end face side and becomes shorter toward the second end face side.

A method for producing a light guide member having the above-described configuration, in which a rod-shaped extrusion molded body is formed by extrusion molding, and by irradiating a laser on a surface constituting the reflection surface of the extrusion molded body, A diffusion groove forming step in which the plurality of diffusion grooves are formed in each of the shape change regions; and a cutting step in which the extruded product is cut into a desired length. By changing the irradiation angle, the angle between the side surface on the first end surface side of the diffusion groove and the flat surface is changed from the first end surface to the plurality of diffusion grooves in each shape change region. It is characterized by being formed so as to decrease or increase regularly in a direction toward the second end face .

Further, it is preferable to perform the diffusion groove forming step and the cutting step in the molding process and in-line.

  In the light guide member of the present invention, the shapes of the plurality of diffusion grooves in the shape change region are all changed instead of the same shape. Thereby, the light which reached the diffusion groove can be diffused in various directions.

  In the method for manufacturing a light guide member of the present invention, the cross-sectional shape of the diffusion groove is changed. Thereby, the light which reached the diffusion groove can be diffused in various directions.

FIG. 1A is a perspective view of the light guide member of this embodiment, and FIG. 1B is a front view of the first end face of the light incident surface of the light guide member of this embodiment. It is a top view when the light source is arrange | positioned at the both ends of the light guide member of this embodiment. It is a partial expanded sectional view of the shape of the some diffusion groove of the light guide member of this embodiment. 4A is a plan view when the diffusion groove of the light guide member of the present embodiment is inclined, and FIG. 4B is a plan view when the interval of the diffusion groove of the light guide member of the present embodiment is widened toward both ends. It is. It is explanatory drawing which shows the manufacturing apparatus of the light guide member of this embodiment. FIG. 6A is an explanatory view showing a laser processing machine for forming the diffusion groove of the light guide member of this embodiment, and FIG. 6B is a schematic cross-sectional view when the diffusion groove is formed by the laser processing machine.

  Hereinafter, the present invention will be described based on embodiments shown in the accompanying drawings.

  The light guide member 1 is formed of a material having translucency. As the material of the light guide member 1, for example, a material obtained by adding polymethyl acrylate (PMA) or acrylic rubber to polymethyl methacrylate (PMMA) is suitably used. PMA and acrylic rubber have substantially the same refractive index of light as PMMA, and it is difficult to impair transparency, so that moldability and impact resistance can be improved.

  As shown in FIGS. 1A and 2, the light guide member 1 is of a straight bar shape and emits light when light from the light source 20 is incident from an end face in the longitudinal direction. Although LED is used suitably for the light source 20, it is not specifically limited.

  The light guide member 1 includes a first end surface 11 on which light from the light source 20 is incident, and a second end surface 12 disposed at a position opposite to the first end surface 11. The light guide member 1 includes a reflective surface 13 that is provided along a direction in which the first end surface 11 and the second end surface 12 face each other and reflects light incident from the first end surface 11. The light guide member 1 includes a light exit surface 15 that is provided along a direction in which the first end surface 11 and the second end surface 12 face each other and from which light reflected by the reflective surface 13 is emitted. Here, the light exit surface 15 is disposed at a position opposite to the reflection surface 13.

  The first end surface 11 is a flat surface and has a shape that allows light from the light source 20 to easily pass therethrough. The shape of the first end surface 11 is the same as the shape of the cross section in the direction orthogonal to the longitudinal direction of the light guide member 1 (hereinafter simply referred to as the cross sectional shape). As shown in FIG. 1B, the cross-sectional shape of the light guide member 1 is a long shape that is long in the direction in which the reflective surface 13 and the light exit surface 15 face each other (hereinafter simply referred to as the height direction). The cross-sectional shape is an axisymmetric shape with respect to a center line 11c passing through the center of the light guide member 1 in the direction orthogonal to the longitudinal direction and the height direction (hereinafter simply referred to as the width direction).

  In the cross-sectional shape of the light guide member 1, a reflective surface 13 is provided at one end in the height direction, and a light exit surface 15 is provided at the other end in the height direction. Side surfaces 11 a are provided from both ends in the width direction of the reflecting surface 13 to both ends in the width direction of the light exit surface 15. A protrusion 11b that protrudes outward in the width direction is formed at the intermediate portion in the height direction of each side surface portion 11a. Each protrusion 11b has a substantially right triangle shape in cross section in a direction perpendicular to the longitudinal direction of the light guide member 1. In addition, the shape of the cross section of the protrusion 11b in the direction orthogonal to the longitudinal direction of the light guide member 1 is not limited to a substantially right triangle.

  The side part 11a curves so that it may be located in the outer side of the width direction, so that it goes from the edge part by the side of the reflective surface 13 to the edge part by the side of the reflective surface 13 of the protrusion 11b. The side surface portion 11a is formed in a straight line parallel to the height direction from the end on the light exit surface 15 side of the protrusion 11b to the end on the exit surface side of the side surface portion 11a.

  Each side surface portion 11a has the shape as described above in order to efficiently reflect the light reflected by the reflecting surface 13 toward the light emitting surface 15 side. Further, the protrusion 11b is used for hooking and fixing the light guide member 1 to another member (for example, a casing).

  The second end surface 12 has the same shape as the first end surface 11. In the present embodiment, the light source 20 is disposed on the first end surface 11 and the second end surface 12 as shown in FIG. 2, but the light source 20 is disposed only on the first end surface 11 and the second end surface. 12 may be provided with a reflective material. The reflective material may be deposited on the second end surface 12 by, for example, silver deposition.

  As shown in FIG. 3, the reflecting surface 13 includes a plurality of diffusion grooves 13a for diffusing light incident from the first end surface 11 and the second end surface 12, and a flat surface 13b provided in a portion other than the diffusion grooves 13a. Have. A plurality of diffusion grooves 13 a arranged side by side in the longitudinal direction of the light guide member 1 are provided so as to extend between the end portion on the first end surface 11 side and the end portion on the second end surface 12 side of the reflection surface 13. . The diffusion grooves 13 a are formed long in the width direction of the light guide member 1, and a plurality of diffusion grooves 13 a are formed in the longitudinal direction of the light guide member 1. In the present embodiment, the diffusion groove 13a is formed by processing a surface constituting the reflection surface 13.

  The diffusion groove 13a is formed by applying a surface processing method such as electric discharge machining, fine particle spraying, imprinting, etching, printing, or laser to a flat surface.

  In this embodiment, the reflecting surface 13 includes at least one shape change region 14 having diffusion grooves 13a having different cross-sectional shapes, as shown in FIGS. Of the plurality of diffusion grooves 13 a provided side by side on the reflection surface 13, the first portion is the portion where the diffusion grooves 13 a having the same cross-sectional shape are formed in the direction from the first end surface 11 to the second end surface 12. The shape change region 14 becomes. Then, the second shape change region 14 is formed up to the portion where the diffusion groove 13a having the same cross-sectional shape is formed. In this manner, the region up to the diffusion groove 13a closest to the second end face 12 is divided by the shape change region. The shape change region 14 may be partitioned in a direction from the second end surface 12 toward the first end surface 11.

  If the cross-sectional shapes of the plurality of diffusion grooves 13a are all different, one shape change region 14 is provided on the reflection surface 13. When a plurality of shape change regions 14 are provided, if the change in the cross-sectional shape of the diffusion groove 13a in each shape change region 14 is the same, the size of each shape change region 14 is the same. However, if the change in the cross-sectional shape of the diffusion groove 13a is different, the size of each shape change region 14 is different.

  Moreover, it is preferable that a plurality of shape change regions 14 are provided on the reflection surface 13 and that the change in the cross-sectional shape of the diffusion groove 13a in each shape change region 14 is the same. Thereby, the diffusibility on the reflecting surface 13 is improved, and the change in the cross-sectional shape of the diffusion groove 13a in the plurality of shape change regions 14 is the same, so that the shape change region 14 can be easily formed.

  In addition, the angle between the side surface on the first end surface 11 side of the diffusion groove 13a in the shape change region 14 and the flat surface 13b regularly decreases in the direction from the first end surface 11 toward the second end surface 12. Is preferred. The angle between the side surface on the first end surface 11 side of the diffusion groove 13a in the shape change region 14 and the flat surface 13b increases regularly in the direction from the first end surface 11 toward the second end surface 12. Also good. Thereby, the diffusibility on the reflecting surface 13 is improved, and the regularity of the shape change of the plurality of diffusion grooves 13a in the shape change region 14 is simple, so the shape change region 14 can be easily formed.

  As shown in FIG. 4A, the diffusion groove 13 a may be formed to be inclined with respect to the width direction of the light guide member 1. Thereby, the incident angle with respect to the side surface of the diffusion groove | channel 13a of the light which injects and advances from the 1st end surface 11 and the 2nd end surface 12 becomes large. Accordingly, the light reaching the side surface of the diffusion groove 13a is easily reflected, so that the light guide member 1 can emit light efficiently.

  Further, when light is incident from both end surfaces of the first end surface 11 and the second end surface 12 of the light guide member 1, the center in the longitudinal direction of the light guide member 1 separated from the first end surface 11 and the second end surface 12. It becomes difficult for light to reach the part. Therefore, as shown in FIG. 2, the length of each diffusion groove 13 a may be formed so as to increase toward the center of the light guide member 1. As shown in FIG. 4B, the distance between the respective diffusion grooves 13 a may be formed so as to increase from the center in the longitudinal direction of the light guide member 1 toward both ends of the reflection surface 13. Thereby, the light emitted from the light exit surface 15 of the light guide member 1 becomes uniform.

  The flat surface 13b is not subjected to the surface processing method described above.

  As illustrated in FIG. 1B, the light exit surface 15 is a concave curved surface that is curved so as to approach the reflection surface 13 toward the center side in the width direction of the light guide member 1. For this reason, since the light emitted from the light exit surface 15 is easily bent outward in the width direction, the light emitted from the light exit surface 15 can illuminate an area wider than the light exit surface 15. The light exit surface 15 may be a convex curved surface that is curved away from the reflection surface 13 toward the center side in the width direction of the light guide member 1. Thereby, the light distribution characteristic of the light radiate | emitted from the light emission surface 15 can be adjusted to a condensing direction.

  In the light guide member 1, light incident from the light source 20 through the first end surface 11 travels toward the second end surface 12, and in the process, the light is reflected by the reflecting surface 13 toward the light exit surface 15. Further, in the light guide member 1, the light incident from the light source 20 through the second end surface 12 travels toward the first end surface 11, and in the process, the light is reflected by the reflecting surface 13 toward the light exit surface 15. . Among these, the light reaching the diffusion groove 13a of the reflection surface 13 is diffused by the diffusion groove 13a. In this way, the light reflected and diffused by the reflection surface 13 is emitted from the light exit surface 15, and the light guide member 1 emits strip-like light from the entire light exit surface 15.

  In the light guide member 1 having the above-described configuration, the cross-sectional shapes of the plurality of diffusion grooves 13 a are changed in the shape change region 14. Thereby, in the shape change area | region 14, the light which reached the diffusion groove | channel 13a can be diffused in various directions.

  A method for manufacturing the light guide member 1 having the above-described configuration will be described below.

  The light guide member 1 of the present embodiment is manufactured by processing the extruded product 50. FIG. 5 shows a manufacturing apparatus constituting the production line for the light guide member 1. The manufacturing apparatus includes an extrusion molding machine 30, an extrusion die 31, a sizing 32, a water tank 33, a pulling machine 34, a laser processing machine 4, a cutting machine 35, and an alignment machine 36. The extrusion molding machine 30, the extrusion mold 31, the sizing 32, the water tank 33, the pulling machine 34, the laser processing machine 4, the cutting machine 35, and the alignment machine 36 are sequentially arranged in this order from the upstream side of the production line. In addition, although extrusion molding is used in manufacture of the light guide member 1 of this embodiment, the manufacturing method is not limited.

  In the manufacturing apparatus, an extrusion process, a sizing process, a cooling process, a pulling process, a diffusion groove forming process, a cutting process, and an alignment process are continuously performed, whereby the light guide member 1 is manufactured.

  An extrusion die 31 is disposed at the tip of the extrusion molding machine 30. The extrusion process is performed by plasticizing the synthetic resin material to be the light guide member 1 by the extrusion molding machine 30 and extruding it to the extrusion die 31 side. Thereby, the extrusion molded body 50 as an intermediate product of the light guide member 1 is extruded to the downstream side of the line through the extrusion die 31.

  A sizing process, a cooling process, a diffusion groove forming process, a cutting process, and an alignment process are sequentially performed on the extruded product 50 that has been extruded by the extrusion process.

  The pulling process is performed by a pulling machine 34. The tensioner 34 pulls the extruded product 50 extruded from the extrusion die 31. The extrusion-molded body 50 passes through the sizing 32 and the water tank 33 in order by being pulled by the pulling machine 34.

  The sizing process is performed by sizing 32. The extrudate 50 pulled by the puller 34 passes through the sizing 32. By this sizing process, the cross-sectional shape of the extruded product 50 becomes the same as the cross-sectional shape of the light guide member 1 that is a product.

  The cooling process is performed by the water tank 33. The extruded product 50 pulled by the puller 34 passes through the water tank 33. In this cooling step, the extruded product 50 is cooled and solidified by the water in the water tank 33. The extrusion-molded body 50 cooled in the cooling process passes through the pulling machine 34 and then passes through the laser processing machine 4 and the cutting machine 35 in order.

  The diffusion groove forming process (cutting process) is performed by irradiating the laser beam from the laser processing machine 4 toward the extruded molded body 50 moving by the tension machine 34.

  The laser beam machine 4 includes a laser oscillator 41, a beam expander 42, a galvano scanner 43, and an fθ lens 44 as shown in FIG. 6A. That is, the laser processing machine 4 uses the galvano scanning method as the laser method.

  In the diffusion groove forming step, the diffusion groove 13 a is formed on the reflection surface 13 of the extrusion molded body 50 by the laser irradiated from the laser processing machine 4. At this time, the laser beam machine 4 irradiates the carbon dioxide laser with, for example, about 30 W. Further, the laser irradiation from the laser processing machine 4 is performed on the surface constituting the reflection surface 13 of the extrusion molded body 50 that is extruded by the extrusion molding machine 30 and passes through the vicinity of the laser processing machine 4. That is, the diffusion groove forming process is performed in-line with the molding process.

  Specifically, the laser beam machine 4 scans the laser beam by driving the mirror of the galvano scanner 43 based on a preset machining pattern, and forms the diffusion groove 13a by the scanned laser beam. In FIG. 6A, the scanning direction of the laser is indicated by an arrow. In the present embodiment, the laser irradiation angle is the first irradiation angle with respect to the longitudinal direction of the extrusion-molded body 50 and the first irradiation angle with respect to the direction orthogonal to the longitudinal direction of the extrusion-molding body 50 and the direction from the reflecting surface 13 toward the light exit surface 15. And the second irradiation angle.

  The mirror includes a first mirror 43a that determines the first irradiation angle and a second mirror 43b that determines the second irradiation angle. The laser emitted from the laser oscillator 41 passes through the beam expander 42, is reflected by the first mirror 43a, is further reflected by the second mirror 43b, and the reflected light is condensed through the fθ lens 44. .

  The first mirror 43a includes an axis whose axial direction is a direction parallel to the direction from the reflecting surface 13 toward the light exit surface 15, and rotates a certain range in the circumferential direction around the axis. Here, the certain range refers to a range in which light refracted by the first mirror 43a hits the second mirror 43b. The maximum irradiation angle and the minimum irradiation angle of the first irradiation angle are determined by this certain range.

  The second mirror 43b includes an axis whose axial direction is parallel to the longitudinal direction of the extruded molded body 50, and rotates around a certain range in the circumferential direction around the axis. Here, the certain range refers to a range in which the light refracted by the second mirror 43 b hits the fθ lens 44. The maximum irradiation angle and the minimum irradiation angle of the second irradiation angle are determined based on the certain range.

  Since the first irradiation angle and the second irradiation angle are restricted to a certain range, the laser irradiation range is also restricted to a certain range. It is preferable that the plurality of diffusion grooves 13a be formed by changing the first irradiation angle and the second irradiation angle of the laser between the maximum irradiation angle and the minimum irradiation angle within the laser irradiation range. The diffusion groove 13a within the laser irradiation range is formed by changing the laser irradiation angle, so that the cross-sectional shape thereof is changed. Accordingly, the laser irradiation range becomes the shape change region 14. In the present embodiment, a plurality of diffusion grooves 13a are formed in the laser irradiation range while extruding the extruded molded body 50, and these operations are continuously performed. Thereby, the extrusion molded body 50 provided with at least one shape change area | region 14 in the reflective surface 13 can be formed.

  As shown in FIG. 6B, the shape of the plurality of diffusion grooves 13a formed in the laser irradiation range changes as the angle between the flat surface 13b and the laser changes. Within the laser irradiation range, the acute angle between the flat surface 13b and the laser increases to 90 ° from both longitudinal ends of the extruded product 50 to near the center. At this time, the plurality of diffusion grooves 13 a are formed such that the angle between the side surface on the first end surface 11 side of the diffusion groove 13 a and the flat surface 13 b increases in the direction from the first end surface 12 toward the second end surface 11. The

  The cutting step is performed by cutting the extrusion-molded body 50 by laser irradiation provided in the cutting machine 35. The cutting machine 35 irradiates the extrusion molded body 50 passing through the cutting machine 35 with a carbon dioxide gas laser from a direction orthogonal to the longitudinal direction. At this time, for example, a carbon dioxide laser with an output of 100 W is irradiated from the cutting machine 35. The cutting by the cutting machine 35 is performed on the extruded body 50 that is extruded by the extrusion molding machine 30 and passes through the vicinity of the cutting machine 35. That is, the cutting process is performed in-line with the molding process in the same manner as the diffusion groove forming process.

  In this way, the extruded body 50 is cut by the cutting machine 35, whereby the light guide member 1 having a desired length is cut out. Further, the cut out light guide members 1 are sequentially arranged by the aligner 36.

  In the present embodiment, the plurality of diffusion grooves 13a are formed by laser irradiation, but the method of forming the diffusion grooves 13a is not limited to laser irradiation.

  In the manufacturing method of the light guide member 1 having the above configuration, the cross-sectional shape of the diffusion groove 13a is changed and formed. Thereby, the light which reached the diffusion groove can be diffused in various directions.

  Below, it describes about the structure of the light guide member 1 of this embodiment.

  The light guide member 1 includes a first end surface 11 on which light from the light source 20 is incident, and a second end surface 12 disposed at a position opposite to the first end surface 11. The light guide member 1 includes a reflecting surface 13 that is provided along a direction in which the first end surface 11 and the second end surface 12 face each other and reflects light incident from the first end surface 11. The light guide member 1 includes a light exit surface 15 that is provided along a direction in which the first end surface 11 and the second end surface 12 face each other and from which light reflected by the reflective surface 13 is emitted. The light exit surface 15 is disposed at a position opposite to the reflection surface 13. The reflective surface 13 has a plurality of diffusion grooves 13a for diffusing light, and a flat surface 13b provided in a portion other than the diffusion grooves 13a. The reflection surface 13 includes at least one shape change region 14 having a different cross-sectional shape of each diffusion groove 13a.

  Thus, the shape of the plurality of diffusion grooves 13 a is changed in the shape change region 14. Thereby, the diffusion direction of the light reaching the diffusion groove 13a can be diffused in various directions.

  Moreover, it is preferable that the light guide member 1 is provided with a plurality of shape change regions 14 on the reflection surface 13, and the change in the cross-sectional shape of the diffusion groove 13 a in each shape change region 14 is the same.

  As described above, when the plurality of diffusion grooves 13a in the shape change region 14 are provided with the same change in cross-sectional shape, the shape change region 14 in which the cross-sectional shape of the diffusion groove 13a is changed according to the same rule is formed on the reflection surface 13. A plurality are arranged. Thereby, the diffusibility on the reflective surface 13 is improved, and the shape of the diffusion groove 13a of the plurality of shape change regions 14 is the same, so that the shape change region 14 can be easily formed.

  A plurality of diffusion grooves 13 a are formed in the direction from the first end surface 11 of the reflecting surface 13 toward the second end surface 12. In the shape change region 14, the angle between the side surface on the first end surface 11 side of the diffusion groove 13a and the flat surface 13b regularly decreases or increases in the direction from the first end surface 11 toward the second end surface 12. It is preferable to do.

  Thereby, the diffusibility on the reflecting surface 13 is improved, and the regularity of the shape change of the plurality of diffusion grooves 13a in the shape change region 14 is simple, so the shape change region 14 can be easily formed.

  A plurality of diffusion grooves 13 a are formed in the direction from the first end surface 11 of the reflecting surface 13 toward the second end surface 12. It is preferable that the length direction of the diffusion groove 13a is inclined with respect to the direction from the first end surface 11 toward the second end surface 12 and the direction orthogonal to the direction from the reflection surface 13 toward the light exit surface 15. .

  Thereby, the incident angle with respect to the side surface of the diffusion groove 13a of the light traveling from the first end surface 11 is increased. Accordingly, the light reaching the side surface of the diffusion groove 13a can be easily reflected, so that the light guide member 1 can emit light efficiently.

  In the light guide member 1, light from the light source 20 is incident on both end surfaces of the first end surface 11 and the second end surface 12. The distance between the respective diffusion grooves 13a increases from the center in the direction in which the first end surface 11 and the second end surface 12 of the reflecting surface 13 face each other toward the first end surface 11 side, and on the second end surface 12 side. It is preferable that it becomes wider as it goes to.

  Thereby, the light emitted from the light exit surface 15 of the light guide member 1 becomes uniform.

  In the light guide member 1, light from the light source 20 is incident on both end surfaces of the first end surface 11 and the second end surface 12. The length of the diffusion groove 13a decreases from the center of the reflecting surface 13 in the direction in which the first end surface 11 and the second end surface 12 face each other toward the first end surface 11 side and goes to the second end surface 12 side. It is preferable that the length becomes shorter.

  Thereby, the light emitted from the light exit surface 15 of the light guide member 1 becomes uniform.

  The manufacturing method of the light guide member 1 of this embodiment is described below.

  In the manufacturing method of the light guide member 1 having the above-described configuration, a plurality of diffusion grooves 13a having different cross-sectional shapes are formed.

  Thereby, the diffusion direction of the light reaching the diffusion groove 13a is not the same, and the light can be diffused in various directions.

  The manufacturing method of the light guide member 1 includes a molding process in which a rod-like extruded body 50 is molded by extrusion molding. The method for manufacturing the light guide member 1 includes a diffusion groove forming step in which a plurality of diffusion grooves 13a are formed on the surface constituting the reflection surface 13 of the extruded product 50 by changing the laser irradiation angle. The method for manufacturing the light guide member 1 includes a cutting step in which the extruded product 50 is cut to a desired length.

  As described above, when the irradiation angle of the laser emitted from the laser processing machine 4 is changed, all the cross-sectional shapes of the diffusion grooves 13a within the laser irradiation range are changed and formed. Thereby, the diffusion direction of the light reaching the diffusion groove 13a is not the same in all the diffusion grooves 13a, but can be diffused in various directions.

  Further, by changing the laser irradiation angle, the angle between the side surface on the first end surface 11 side of the diffusion groove 13 a and the flat surface 13 b is regularly in the direction from the first end surface 11 to the second end surface 12. It is preferable that the diffusion groove 13a be formed.

  Thereby, the light diffusibility on the reflecting surface 13 is improved, and the regularity of the shape change of the plurality of diffusion grooves 13a in the shape change region 14 is simple, so that the shape change region 14 can be easily formed. .

  In the method for manufacturing the light guide member 1, it is preferable to perform the diffusion groove forming step and the cutting step in-line with the molding step.

  Thereby, the productivity of the light guide member 1 can be increased.

DESCRIPTION OF SYMBOLS 1 Light guide member 11 1st end surface 12 2nd end surface 13 Reflecting surface 13a Diffusion groove 13b Flat surface 14 Shape change area 15 Light-emitting surface 20 Light source 4 Laser processing machine

Claims (6)

A rod-shaped light guide member manufactured by processing an extrusion molded body formed by extrusion molding,
One end face in the longitudinal direction of the light guide member, a first end face on which light from a light source is incident;
A second end face that is the other end face in the longitudinal direction of the light guide member and is disposed at a position opposite to the first end face;
A reflecting surface provided along the longitudinal direction and reflecting light incident from the first end surface;
A light exit surface from which light reflected along the longitudinal direction and reflected by the reflective surface is emitted;
The light exit surface is disposed at a position opposite to the reflection surface;
The reflective surface is
A plurality of diffusion grooves for diffusing light, formed by laser irradiation;
A flat surface provided in a portion other than the diffusion groove,
The reflective surface is
A plurality of shape change regions arranged in the longitudinal direction,
Each of the shape change regions has a plurality of diffusion grooves arranged in the longitudinal direction and having different cross-sectional shapes,
The plurality of diffusion grooves in each of the shape change regions have an angle between a side surface on the first end surface side of the diffusion groove and the flat surface in a direction from the first end surface toward the second end surface. Formed to decrease or increase automatically,
The light guide member, wherein the change in the cross-sectional shape of the diffusion groove in the direction from the first end face toward the second end face is the same in each shape change region.   The length direction of the diffusion groove is inclined with respect to a direction from the first end surface to the second end surface and a direction orthogonal to the direction from the reflection surface to the light exit surface. The light guide member according to claim 1. Both end surfaces of the first end surface and the second end surface are light incident surfaces on which light from the light source is incident,
The space between the diffusion grooves is wider from the center of the reflecting surface in the longitudinal direction toward the first end surface and wider toward the second end surface. Or the light guide member of Claim 2. Both end surfaces of the first end surface and the second end surface are light incident surfaces on which light from the light source is incident,
The length of the diffusion groove decreases from the center of the reflection surface in the longitudinal direction toward the first end surface and decreases toward the second end surface. The light guide member according to claim 3. It is a manufacturing method of the light guide member as described in any one of Claims 1 thru | or 4, Comprising:
A molding process in which a rod-like extruded product is formed by extrusion;
A diffusion groove forming step in which the plurality of diffusion grooves are formed in each of the shape change regions by irradiating a laser on a surface constituting the reflection surface of the extruded molded body;
A cutting step in which the extruded body is cut to a desired length, and
By changing the irradiation angle of the laser in the diffusion groove forming step, the angle between the side surface on the first end face side of the diffusion groove and the flat surface is changed in the plurality of diffusion grooves in each shape change region. The method of manufacturing a light guide member, wherein the light guide member is formed so as to regularly decrease or increase in a direction from the first end face toward the second end face.   The method for manufacturing a light guide member according to claim 5, wherein the diffusion groove forming step and the cutting step are performed in-line with the forming step.

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