JP2009037116A - Light emitting device for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device for automobile that makes light incident from the end surface of the longitudinal direction of a plate-like light guide body and displays the design, and illuminates a part along the longitudinal direction of the design. <P>SOLUTION: This light emitting device 10 for automobile comprises the plate-like light guide body 20 that has a recess 30 for displaying the design and displays the design from a light emitting surface 21 on the side opposite to the back surface based on light incident from end surfaces 23 and 24 of the longitudinal direction D1, and a light source 62 for making light incident to end surfaces 23 and 24 of the longitudinal direction D1 of the light guide body 20. At least a part of end surfaces 25 and 26 of the short direction D2 of the light guide body 20 is roughened. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light emitting device for an automobile that displays light by making light incident from an end face in a longitudinal direction of a plate-like light guide having a recess for displaying a design formed on the back surface.

2. Description of the Related Art As a decorative plate that protects a foot portion of an automobile entrance / exit, a scuff plate that displays a design such as a character by light of an LED (light emitting diode) is known.
FIG. 11 shows a vertical cross section of a scuff plate light emitting device described in Japanese Patent Application Laid-Open No. 2002-287671. As shown in the figure, the scuff plate light emitting device 900 includes an LED 910 and a light guide plate 920 in which a side surface 922 serving as an end surface in the longitudinal direction 991 is disposed to face the LED 910 and an upper surface 921 is a light emitting surface. A plurality of display portions are formed on the back surface 923 of the light guide plate 920 such that the bottom surface 926 of the design groove 925 provided on the back surface 923 is positioned closer to the upper surface 921 as the distance from the LED 910 increases.

With the above configuration, the light introduced from the LED 910 into the light guide plate 920 is reflected from the back surface 923 of the light guide plate and then emitted from the upper surface 921 of the light guide plate. Here, the shape of the bottom surface 926 is displayed due to the difference between the reflection by the bottom surface 926 of the groove 925 and the reflection by other portions of the back surface of the light guide plate 923.
JP 2002-287671 A

In the above-described technique, the LED 910 is disposed in the vicinity of the end face of the light guide plate 920 in the longitudinal direction 991, so that light incident on the light guide plate 920 from the LED 910 travels in the light guide plate 920 in a direction centered on the longitudinal direction 991. .
In the scuff plate light emitting device 901 shown in FIG. 12, the traveling direction 993 of the light incident from the LED 930 into the light guide plate 940 is indicated by an arrow. As shown in the figure, since the incident light from the LED 930 travels mainly along the longitudinal direction 992, a portion 945a of the groove 945 formed on the back surface of the light guide plate 940 facing the longitudinal direction has a short direction 994. Compared with other parts such as the part 945b facing the direction, the amount of irradiation is reduced and darkened. Therefore, it is desired that the design of the scuff plate light emitting device is not partially darkened.
In addition, providing an LED near the end face in the short direction of the light guide plate limits the installation space of the scuff plate light emitting device in terms of vehicle design, leading to an increase in the cost of the scuff plate light emitting device due to an increase in the number of parts and an increase in manufacturing man-hours. difficult.

  The present invention has been made in view of the above problems, and an automobile that displays the design by making light incident from an end face in a longitudinal direction of a plate-like light guide formed with a recess for displaying the design on the back surface. An object of the present invention is to lighten a portion along the longitudinal direction of the design.

In order to achieve the above object, the automotive light emitting device of the present invention has a recess for displaying a design formed on the back surface, and the light emitting surface opposite to the back surface based on incident light from the end face in the longitudinal direction. A plate-like light guide for displaying the design, and a light source for making light incident on an end face in the longitudinal direction of the light guide, and at least a part of the end face in the short direction of the light guide is rough. It is characterized by being surfaced.
With the above configuration, light incident from the light source to the end face in the longitudinal direction of the plate-like light guide is reflected by the roughened end face in the short direction of the light guide. As a result, the light traveling in the short direction in the light guide increases, and the light illuminates a portion along the longitudinal direction of the design. Therefore, the part along the longitudinal direction of the design of the light guide can be brightened.

Here, the recess formed on the back surface of the light guide includes a groove-shaped recess, a dish-shaped recess, a combination thereof, and the like.
The plate shape which is the shape of the light guide includes a shape having the above-described recess, and includes a shape having a shape to be attached to an automobile. The plate-shaped light guide includes a flat light guide, a plate-shaped light guide whose light emitting surface, back surface, and end surface are curved, a light guide having a bent plate shape, and the like.
The roughened part of the end face in the short direction of the light guide may be a part roughened by post-processing such as blasting to spray a blast material on the end face of the light guide in the short direction, or the molding surface may be It may be a portion roughened at the same time as molding by shaping the light guide with a roughened mold. Further, the roughening includes roughening of the matte level, forming a groove shape, a combination thereof, and the like.

According to the first aspect of the present invention, in the automotive light emitting device for displaying the design by making light incident from the end face in the longitudinal direction of the plate-like light guide formed on the back surface with a recess for displaying the design. The part along the longitudinal direction of the design can be brightened.
In the invention according to claim 2, the incident light from the end face in the longitudinal direction is irregularly reflected at the roughened portion of the end face in the short direction and the light traveling in the short direction is increased, and the portion along the longitudinal direction of the design is appropriately Can be brightened.
In the invention which concerns on Claim 3, the incident light from the end surface of a longitudinal direction reflects in the groove | channel of the end surface of a transversal direction, the light which goes to a transversal direction increases, and the part along the longitudinal direction of a design is made bright appropriately be able to.
In the invention which concerns on Claim 4, since the incident light which faced the longitudinal direction from a light source reflects substantially all by the opposing part of a substantially V-shaped groove | channel, the part along the longitudinal direction of a design can be further brightened.

In the invention which concerns on Claim 5, since the space | interval of a groove | channel is narrow if it is far from a light source, reflected light increases and the part along the longitudinal direction of a design can be made bright appropriately.
In the invention which concerns on Claim 6, since a groove | channel is deep when it is far from a light source, reflected light increases, and the part along the longitudinal direction of the design can be made bright appropriately.
In the invention which concerns on Claim 7, when the dent for designs is arranged in multiple numbers in the longitudinal direction of a light guide, the part along the longitudinal direction of each design can be further brightened.
In the invention which concerns on Claim 8, the part along the longitudinal direction of each design can be further brightened appropriately.

(1) Structure of light emitting device for automobile:
FIG. 1 is a perspective view of a main part showing the interior of an automobile employing a light emitting device 10 for an automobile according to an embodiment of the present invention, FIG. 2 is a plan view of the light emitting device 10, and FIG. 3 shows the light emitting device 10 shown in FIG. FIG. 4 is a plan view of the reflective film 76, and FIG. 5 is a cross-sectional view of various light emitting devices 10a to 10d at the position A2-A2 in FIG. FIG. 6 to FIG. 8 are plan views showing the main parts of various light guides 20e to 20i, and FIG. 9 is a view schematically showing the blast device 100. In FIG. 2, the cover 74 is viewed in cross section.
2, the longitudinal direction D1 of the light guide 20 is a long direction when facing the light emitting surface 21, and the short direction D2 of the light guide 20 is a short direction when facing the light emitting surface 21. And Incident light from the light source 62 travels in the light guide 20 in a direction centered on the longitudinal direction D1. As shown in FIG. 3, the thickness direction D3 of the light guide 20 is a direction orthogonal to the longitudinal direction D1 and the short direction D2. The light emitted from the light emitting surface 21 travels in a direction centered on the thickness direction D3.

In FIG. 1, the main part of the road traveling vehicle is shown from behind the front seat 82 to the rear seat 83 with the door 84 opened. The scuff plate 1 is installed at the lower edge of the door opening 81 of the automobile shown in the figure, and the automobile light emitting device 10 according to the present invention is provided on the scuff plate 1.
The scuff plate functions to enhance the design of the passenger compartment by covering the body panel that forms the lower edge of the door opening to protect the foot of the entrance and exiting the door, and the like, such as a logo type design such as the car name. Have Since the scuff plate 1 of the present embodiment has designs such as letters and logotypes emerging from the light emitting surface 21 of the light emitting device 10, the interior decoration effect can be further enhanced, and a high-class feeling can be imparted to the automobile.

The basic part of the light emitting device 10 includes a plate-shaped light guide 20 and a light source 62. The light emitting device 10 of the present embodiment is configured by including a light source 62 in a light source unit 60 and housing light guides 20, a light source unit 60, and a reflective film 76 in cases 72 and 74.
The light guide 20 has a recess 30 for displaying a design formed on the back surface 22, and the design is transmitted from the light emitting surface 21 opposite to the back surface 22 based on incident light from the end surfaces 23 and 24 in the longitudinal direction D <b> 1. indicate. That is, the light emitting surface 21 is a surface on which the design corresponding to the dent 30 appears in the light guide 20. The light source 62 makes light incident on the end faces 23 and 24 in the longitudinal direction D1 of the light guide 20. That is, these end surfaces 23 and 24 are light receiving surfaces for light emitted from the light source 62. At least a part of the end faces 25 and 26 in the lateral direction D2 of the light guide 20 is roughened. Thereby, this light-emitting device 10 is such that the portion 31 along the longitudinal direction D1 of the design of the light guide 20 does not become too dark compared to the portion 32 along the short direction D2 of the design of the light guide 20. indicate.

As shown in FIG. 3, in the light emitting device 10 of this embodiment, a reflective film 76 is placed on a bottom plate 72, and a light guide 20 is placed on the film 76. Cutout portions 27 are formed on the light emitting surface side at both ends in the longitudinal direction of the light guide 20. The plate shape which is the shape of the light guide 20 includes the shape of the light guide having the recess 30 and the notch 27. A plurality of light sources 62 are disposed in the vicinity of both end faces 23 and 24 in the longitudinal direction D1 of the light guide 20 and irradiate the both end faces 23 and 24 with light. The light source units 60 and 60 and the notches 27 and 27 are covered with a light-shielding cover 74. Since the light source units 60 and 60 cannot be directly visually recognized by the cover 74, the design of the light emitting device 10 is improved. Further, when the depth of the notches 27, 27 in the thickness direction D3 is substantially the same as the thickness of the cover 74 of the portion covered by the notches, the light emitting surface 21 and the cover 74 can be made substantially flush with each other. The device 10 can be made into a clean and preferable design with a sense of unity.
Cases 72 and 74 are made of a metal such as stainless steel by press molding or the like, or a light-shielding resin molding material such as a thermoplastic resin added with a colorant is molded by injection molding or press molding or the like. Can be used. Alternatively, a case may be formed by laminating a skin material such as a nonwoven fabric, a woven fabric, or a knitted fabric on a metal or resin molding material.

  As the reflective film 76, a film in which a metal thin film is laminated on a resin film such as a thermoplastic resin can be used. As the resin film, a polyethylene terephthalate (PET) film or the like can be used. Aluminum or the like can be used for the metal, and a film or the like obtained by depositing metal on the surface of the resin film can be used for the reflective film 76. By disposing the reflective film 76 on the back side of the light guide 20, the amount of light emitted from the light emitting surface 21 can be increased, and the design can be displayed more brightly.

Moreover, as shown in FIG. 4, the hairline film which gave the linear pattern 76a extended in the longitudinal direction D1 can be used for the reflective film 76. As shown in FIG. In this case, the appearance of the light emitting device 10 can be improved, and the incident light from the light source 62 can be prevented from being irregularly reflected in the longitudinal direction D1, so that the design can be displayed more clearly and decorated. The effect can be enhanced.
If the size of the reflective film 76 is slightly wider than the back surface 22 of the light guide 20, the appearance of the light emitting device 10 can be improved.

The light source unit 60 includes a light source 62, a printed circuit board on which a circuit for lighting and driving the light source is formed, and the like. The light source unit 60 is electrically connected to a control circuit (not shown). For example, the light source 62 is turned on when the door is opened, and the light source 62 is turned off when the door is closed.
As the light source 62, an LED (light emitting diode) that is small in size, has directivity in the irradiation direction, and has a long lifetime can be suitably used. Of course, an incandescent bulb, a halogen bulb, a fluorescent lamp, a discharge lamp, or the like can be used as the light source 62. Various colors such as white, red, green, and blue can be adopted as the light emission color of the light source, and the same light emitting device 10 may be used in combination with light sources of different emission colors.

  In the present embodiment, two light sources 62 are arranged respectively toward the end faces 23 and 24 of the light guide so that the light irradiation direction is a direction centering on the longitudinal direction D1 of the light guide. Of course, the number of light sources arranged facing each of the end surfaces 23 and 24 may be one or three or more, and the light source may be arranged only in one of the positions facing the end surfaces 23 and 24. The light source may be disposed in contact with the end surfaces 23 and 24 or may be disposed away from the end surfaces 23 and 24.

  The plate-like light guide 20 can be a transparent or translucent molded product obtained by molding a transparent or translucent resin molding material by injection molding or press molding. As the resin constituting the resin molding material, an acrylic resin, polycarbonate, or the like having excellent translucency can be used. The light guide 20 of the present embodiment has a thin plate-like substantially rectangular parallelepiped shape having a recess 30 and a notch 27, that is, a substantially flat plate shape, from the viewpoint of making the brightness of the entire light emitting surface as uniform as possible. Of course, the light guide 20 may have a shape in which a part or all of the surfaces 21 to 26 constituting the light guide are curved, or may be a curved shape as a whole.

The light emitting surface 21 of the light guide 20 has a planar shape except for the notches 27 and 27. The back surface 22 facing the reflective film 76 has a recess 30 for displaying a design, and has a planar shape excluding the recess. The recess 30 of the present embodiment has a groove shape that is recessed to the middle of the thickness of the light guide 20 so as to be carved from the back surface 22 toward the light emitting surface 21, and the width gradually increases from the back surface 22 toward the inside of the light guide. It is formed in a decreasing shape, and the side surface is inclined. A plurality of such recesses 30 are arranged in the longitudinal direction D1 with respect to the back surface 22 of the light guide. When displaying a design composed of characters or logotypes, it is preferable to form the recess 30 in a groove shape because the design can be clearly displayed. Of course, it is also possible to make the dent into a flat plate shape, a combination of a groove shape and a flat plate shape, or the like.
The end faces 23 and 24 in the longitudinal direction of the light guide have a planar shape in order to reduce reflection and refraction of light from the light source 62. Light incident on the light guide 20 from the light source 62 travels in a direction centered on the longitudinal direction D1. End surfaces 25 and 26 in the short direction of the light guide are formed along the longitudinal direction D1.

If the end face in the short direction of the light guide is not roughened, the incident light from the light source travels in a direction centered on the longitudinal direction. Incident light traveling in the direction along the longitudinal direction travels in the direction along the longitudinal direction even when reflected by the end face in the short direction. In a light-emitting device using a light guide that is not roughened at all in the lateral direction, the portion along the longitudinal direction of the recess formed on the back surface of the light guide is a portion along the short direction. Compared to the amount of irradiation, it becomes darker. That is, the design of the light emitting device is partially darkened.
Therefore, in the light emitting device 10, a part or the whole of the end faces 25 and 26 of the light guide is roughened (roughened part). In FIG. 2, it is shown that both end surfaces 25 and 26 are roughened portions 40.

FIG. 5 shows various light emitting devices having different roughened portions in a cross-sectional view at the position A2-A2 in FIG.
The end surface 26a of the light guide 20a of the light emitting device 10a is all made into a roughened portion 41 by a blasting process for spraying a blast material. Here, a sandblasting process in which sand or the like is blown to make the surface matt can be employed for the blasting process. As the blast material, sand, granular glass, granular alumina, granular metal such as a steel ball, granular plastic, or the like can be used. A large number of fine irregularities are formed on the end face of the light guide by blasting. A part of the end surface 26b of the light guide 20b of the light emitting device 10b is a roughened portion 42 by blasting. Of course, part or all of the end faces of the light guides 20a and 20b opposite to the end faces 26a and 26b may be roughened by blasting.
When at least a part of the end surface in the short direction D2 is roughened by blasting, incident light from the end surface in the long direction D1 is irregularly reflected by the roughened portions 41 and 42 on the end surface in the short direction D2. As a result, the amount of light traveling in the short direction D2 in the light guide increases, and the reflected light from the roughened portions 41 and 42 travels in various directions, so that the amount of light emitted from the light emitting surface 21 of the light guide Can be appropriately increased, and the portion 31 along the longitudinal direction D1 of the design can be appropriately brightened.

  Further, in the light guide 20b, the end face 26b in the short direction D2 of the light guide 20b is roughened at a position corresponding to each of the plurality of recesses 30 arranged in the longitudinal direction D1. Thereby, since the light along the transversal direction D2 can be increased according to the position of each dent 30, when a plurality of design dents 30 are arranged in the longitudinal direction D1 of the light guide, The portion 31 along the longitudinal direction D1 can be further brightened.

FIG. 9 schematically shows the blasting apparatus 100. The blasting apparatus 100 sprays the blast material 110 together with the compressed air from the nozzle 101 toward the workpiece W1 to be processed, and performs a blasting process on the surface of the workpiece W1. Here, the blasting process of the central portion W1a of the blasting material 110 sprayed part (the part where the blasting material 110 is sprayed) on the surface of the workpiece W1 is made stronger than the blasting process of the peripheral parts W1b and W1b of the spraying part. Therefore, the light guide 20b shown in FIG. 5 is used as a work W1, and the blasting process is performed by moving the central portion W1a of the blast material sprayed portion in the thickness direction D3 at the intermediate portion 42a in the longitudinal direction D1 at the position aligned with each recess 30 May be performed. Then, the end surface 26b in the short direction D2 of the light guide 20b is roughened by blasting at a position corresponding to each of the plurality of recesses 30, and the intermediate portion 42a in the longitudinal direction D1 in each roughened portion 42. This blasting process is made stronger than the blasting process at both end portions 42b and 42b in the longitudinal direction D1.
With the above configuration, the degree of irregular reflection of the incident light from the end surface in the longitudinal direction D1 on the roughened portion 42 is intermediate between the positions where the recesses 30 are aligned rather than the both end portions 42b, 42b of the positions where the recesses 30 are aligned. The portion 42a is stronger. Thereby, the part 31 along the longitudinal direction D1 of each design can be appropriately brightened with a more natural feeling.

The end face 26c of the light guide 20c of the light emitting device 10c shown in FIG. 5 has a plurality of fine grooves 43 in the thickness direction D3 that partially connect the back surface 22 and the light emitting surface 21 and are arranged at substantially equal intervals in the longitudinal direction D1. As a result, a part of the end face 26c is roughened. That is, the portion of the end surface 26c where the groove 43 is formed is a roughened portion. It can be said that these grooves 43 have a fine uneven shape. Of course, the roughened portion may be formed by arranging the grooves 43 in the longitudinal direction D1 in all of the end face 26c. Further, part or all of the end surface of the light guide 20c opposite to the end surface 26c may be roughened by the plurality of grooves 43. The intervals between the grooves arranged in the longitudinal direction may not be equal. The direction of the groove may be a direction shifted from the thickness direction D3 to the longitudinal direction D1. The shape of the groove is not limited to a straight line, but may be a curved line, a broken line, or the like.
When a resin molding material is molded with a molding die having the shape of the light guide 20c, an elongated convex shape corresponding to the plurality of grooves 43 is formed on the molding surface of the molding die by using a tool that is harder than the molding tool such as a diamond tool. The plurality of grooves 43 are formed by transferring the convex shape to the end face in the short direction during molding. If grooves are formed in the light guide after molding by post-processing, fine grooves cannot be formed due to processing limitations, but by forming a fine convex shape corresponding to the grooves in the mold, the short side of the light guide It becomes possible to form a fine groove on the end face in the direction.

When at least a part of the end face in the short direction D2 is roughened by the groove 43, the incident light from the end face in the long direction D1 is reflected by the groove 43 on the end face in the short direction D2. As a result, the amount of light traveling in the lateral direction D2 in the light guide increases, so that the amount of light emitted from the light emitting surface 21 of the light guide increases appropriately, and the portion 31 along the longitudinal direction D1 of the design is appropriately brightened. can do.
Further, in the light guide 20c, the end face 26c in the short direction D2 of the light guide 20c is roughened at a position corresponding to each of the plurality of recesses 30 arranged in the longitudinal direction D1. Thereby, since the light along the transversal direction D2 can be increased according to the position of each dent 30, when a plurality of design dents 30 are arranged in the longitudinal direction D1 of the light guide, The portion 31 along the longitudinal direction D1 can be further brightened.

On the end face 26d of the light guide 20d of the light emitting device 10d shown in FIG. 5, a plurality of grooves 44b extending in the thickness direction D3 connecting the back face 22 and the light emitting face 21 are arranged in the longitudinal direction D1 and sprayed with a blast material. All of the surfaces are roughened 44a by blasting. That is, a portion of the end face 26d where the groove 44b is formed is a portion roughened by the groove 44b and blasting, and the remaining portion is a portion roughened only by the blasting. Of course, the blasting process may be performed only on the portion where the groove 44b is formed, or the entire end face 26d may be roughened by the groove 44b and the blasting process. In addition, the end face of the light guide 20d opposite to the end face 26d may be partially or entirely roughened by the groove 44b and blasting.
The light guide 20d is formed, for example, by molding a resin molding material with a molding die in which elongated convex shapes corresponding to the plurality of grooves 44b are formed on the molding surface, and blasting the end surface in the short direction of the light guide. Is formed.

  When a plurality of grooves are formed on the end surface in the short direction of the light guide, the portion along the longitudinal direction D1 of the design becomes bright, but the shape of the grooves is transferred to the recess illuminated by the reflected light from the groove. Sometimes. Moreover, the light emission aspect of a dent may differ by the part illuminated by the reflected light from the said groove | channel, and the part not illuminated. Since the end surface of the light guide 20d in the short direction D2 is blasted, the shape of the groove transferred to the recess 30 is blurred, and is illuminated with the reflected light from the groove 44b in the recess 30. The boundary between the part that is illuminated and the part that is not illuminated is also blurred. Therefore, the brightness of a design such as a character or logo design is appropriately increased, and the portion 31 along the longitudinal direction D1 of the design can be appropriately brightened.

  Note that the light guide described above may be subjected to surface treatment such as diamond cutting, embossing, etching, or the like instead of blasting such as sandblasting.

  6 to 8 show various light guides 20e to 20i having different grooves as viewed from the light emitting surface 21 side. The light guides 20e and 20i are each provided with a light source in the vicinity of both end faces in the longitudinal direction D1, and the center D4 in the traveling direction of incident light from the light source is set to both directions in the longitudinal direction D1. In the light guides 20f to 20h, a light source is provided in the vicinity of the left end face 23 shown in FIG. 2, and the center D4 in the traveling direction of incident light from the light source is set to only the right direction in the longitudinal direction D1. 6 to 8 show that the grooves 45 to 49 are formed on the lower end surfaces 26e to 26i of the light guides 20e to 20i. However, the grooves are formed on the upper end surfaces of the light guides 20e to 20i. May be formed.

A plurality of grooves 45 are formed on the end surface 26e in the short direction D2 of the light guide 20e. Each groove 45 is recessed in a substantially V shape from the end face 26e in the short-side direction D2 so as to form a cross-sectional triangle having a certain angle with respect to the center D4 in the traveling direction of incident light, and faces the end face where light from the light source enters The portions 45a and 45b are inclined surfaces facing the inner side of the light guide 20e at angles θ1 and θ2 that are greater than 0 ° and less than or equal to 45 ° from the end face 26e in the short direction. Here, the left incident end surface facing portion 45a in FIG. 6 is a portion facing the left end surface 23 shown in FIG. 2, and the right incident end surface facing portion 45b in FIG. 6 is a portion facing the right end surface 24 shown in FIG. It is.
In the light guide 20e, as indicated by an arrow D5e in FIG. 6, substantially all incident light directed in the longitudinal direction D1 is reflected by the incident end face facing portions 45a and 45b of the substantially V-shaped groove. Therefore, the amount of light emitted from the light emitting surface 21 of the light guide can be increased, and the portion 31 along the longitudinal direction D1 of the design can be further brightened.

A plurality of grooves 46 are formed on the end surface 26f in the short direction D2 of the light guide 20f. Each groove 46 is recessed in a substantially V shape from the end face 26f in the short direction D2 so as to form a cross-sectional triangle having a fixed angle with respect to the center D4 in the traveling direction of incident light, and faces the end face where light from the light source enters. The portion 46a is a slope that faces the inner side of the light guide 20f at an angle θ3 that is greater than 0 ° and equal to or less than 45 ° from the end face 26f in the short direction. On the other hand, the non-facing portion 46b that does not face the end face on which light enters is inward of the light guide 20f at an angle θ4 of greater than 45 ° and less than or equal to 135 ° (preferably 90 °) from the end face 26f in the short direction. It is said that the surface is facing.
In the light guide 20f, as indicated by an arrow D5f in FIG. 6, almost all incident light directed in the longitudinal direction D1 is reflected by the incident end face facing portion 46a of the substantially V-shaped groove. On the other hand, since the non-opposing portion 46b stands up, it is suppressed that light outside the design is reflected by the non-opposing portion 46b and illuminates the recess 30. Therefore, the part 31 along the longitudinal direction D1 of the design can be appropriately brightened.

Of the plurality of grooves 47 formed on the end surface 26g in the short direction D2 of the light guide 20g, the grooves adjacent to each other in the longitudinal direction D1 at positions relatively far from the light source are referred to as first and second grooves 47a and 47b. The grooves adjacent to each other in the longitudinal direction D1 at positions relatively close to the light source are referred to as third and fourth grooves 47c and 47d. In the light guide 20g, the interval c1 between the first groove 47a and the second groove 47b is narrower than the interval c2 between the third groove 47c and the fourth groove 47d. If it is far from the light source, the light reflected by the groove 47 becomes weak, but if it is far from the light source, the distance between the grooves is narrow, so that the reflected light D5g increases. Therefore, the portion 31 along the longitudinal direction D1 of the design can be appropriately brightened so as to be more uniform.
In the light guide 20g, the distance between the grooves 47 is gradually narrowed away from the light source. Thereby, the part 31 along the longitudinal direction D1 of the design can be appropriately displayed so as to be more uniform.
In addition, the 1st, 2nd, 3rd, and 4th groove | channels 47a-47d can be selected from the some groove | channel 47 within the range which satisfy | fills the relationship mentioned above.

Of the plurality of grooves 48 formed on the end face 26h in the short direction D2 of the light guide 20h, a groove relatively far from the light source is defined as a fifth groove 48a, and a groove relatively close to the light source is defined as a sixth groove 48b. To do. In the light guide 20g, the depth d1 of the fifth groove 48a is larger than the depth d2 of the sixth groove 48b. If the distance from the light source is far, the light reflected by the groove 48 becomes weak. However, if the distance from the light source is far, the groove 48 is deep and the reflected light increases. Therefore, the portion 31 along the longitudinal direction D1 of the design can be appropriately brightened so as to be more uniform.
In the light guide 20h, the groove is gradually deepened as the distance from the light source increases. Thereby, the part 31 along the longitudinal direction D1 of the design can be appropriately displayed so as to be more uniform.
The fifth and sixth grooves 48a and 48b can be selected from the plurality of grooves 48 within a range that satisfies the above-described relationship.

In addition, for a plurality of grooves including at least first and second grooves adjacent to each other in the longitudinal direction, and third and fourth grooves closer to the light source than these first and second grooves, The distance between the first groove and the second groove is made smaller than the distance between the third groove and the fourth groove, and the first and second grooves are made deeper than the third and fourth grooves. May be. In this case, the first and second grooves are also the fifth grooves, and the third and fourth grooves are also the sixth grooves. Of course, as the distance from the light source increases, the interval between the grooves may be narrowed and the groove may be deepened.
When light sources are provided in the vicinity of both end faces in the longitudinal direction of the light guide, the intervals between the grooves may be narrowed or the grooves may be deepest in an intermediate portion in the longitudinal direction of the light guide.

  A groove 49 is post-processed on the end surface 26i in the short direction D2 of the light guide 20i using a tool such as a rotary blade. Since the cutting tool of the tool has a processing limit, the interval between the grooves 49 is, for example, about 200 μm, which is wider than the grooves 45 to 48 of the light guides 20e to 20h described above. The groove 49 is formed with a bottom 49a of about 100 μm, for example, and has a trapezoidal cross section. For this reason, the shape of the groove 49 is easily transferred to the recess 30 illuminated by the reflected light from the groove 49. Therefore, when a blasting process in which a blast material is sprayed on the groove 49, the shape of the groove transferred to the recess 30 is blurred, and the portion 31 along the longitudinal direction D1 of the design can be appropriately brightened.

In order to manufacture the light emitting device 10, for example, the following may be performed.
The light guide having the above-described grooves 43, 44b, 45 to 48 is formed by, for example, injecting a liquid resin molding material into a mold in which a long convex shape corresponding to a plurality of grooves is formed on a molding surface using a hard bite. It is formed by doing. Then, at the time of injection molding, the convex shape is transferred to the end face in the short direction, and a plurality of grooves are formed.
In addition, it is preferable to use the metal mold | die which has a slide mechanism so that the said groove | channel may not be rubbed when extruding an injection molded product from a metal mold | die with a pin.

  Then, as shown in FIG. 3, the reflective film 76 is placed on the bottom plate 72, the light guide 20 is placed on the reflective film 76, and in the vicinity of both end faces 23 and 24 in the longitudinal direction of the light guide 20. When the light source units 60 and 60 are installed and the cover 74 is attached to the bottom plate 72 so as to cover the notches 27 and 27 of the light guide and the light source units 60 and 60, the light emitting device 10 is formed. The light emitting device 10 is assembled to the scuff plate 1, and when the scuff plate 1 is assembled to an automobile, the light emitting device 10 is used as a part of the interior of the automobile.

(2) Action and effect of light emitting device for automobile:
Hereinafter, the operation and effect of the automobile light emitting device 10 will be described.
Light incident on the end faces 23 and 24 in the longitudinal direction D1 of the plate-like light guide 20 from the light source 62 is reflected by the design recess 30, the back face 22, and the end faces 25 and 26 in the short direction, and then the light emitting face 21. Radiated from. Here, since the dent 30 is illuminated with incident light, the shape of the dent 30 is displayed as a design. Further, as shown in FIG. 2, the light incident from the light source 62 on the end surfaces 23 and 24 in the longitudinal direction D1 of the plate-like light guide 20 is roughened in the short side direction D2 of the light guide 20. , 26 are reflected.

If the end face in the short direction of the light guide is not roughened, the incident light travels in a direction centered on the longitudinal direction. The light along the longitudinal direction travels in the direction along the longitudinal direction even if it is reflected by the end face in the lateral direction. Therefore, if the end surface in the short direction of the light guide is not roughened at all, the portion along the longitudinal direction of the recess formed on the back surface of the light guide is darker than the portion along the short direction. Become. That is, the design of the light emitting device is partially darkened.
In the light emitting device 10, at least a part of the light reflected by the end faces 25 and 26 travels in the short direction D2 within the light guide 20 as indicated by an arrow D5 in FIG. The portion 31 along the longitudinal direction D1 of the design is illuminated by the light traveling in the direction D2. Accordingly, it is possible to prevent the portion 31 along the longitudinal direction D1 of the design of the light guide 20 from becoming too dark compared to the portion 32 along the short direction D2 of the design of the light guide 20.

  In addition, as described above, when the end faces 25 and 26 in the short direction are roughened by blasting, incident light is irregularly reflected at the roughened portions 40 of the end faces 25 and 26 and travels in the short direction D2. Will increase. When the end faces 25 and 26 in the short direction are roughened by a plurality of grooves directed in the direction connecting the back surface 22 and the light emitting surface 21, incident light is irregularly reflected at the roughened portions 40 of the end faces 25 and 26. The light traveling in the short direction D2 increases. Accordingly, when the end surface in the short direction is roughened by blasting or a plurality of grooves, the portion 31 along the longitudinal direction of the design can be appropriately brightened.

(3) Example:
EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated concretely, this invention is not limited by an Example.

[Preparation of light guide sample]
As the light guide, a transparent acrylic resin molded product having a length of 145 mm in the longitudinal direction, a length of 18 mm in the lateral direction, and a thickness of 2 mm was used. The recess on the back surface of the light guide has a groove shape of 1 mm depth consisting of five Roman letters. The second character from the left is “E”. And the light guide which did not roughen the end surface of a transversal direction was made into the light guide sample of a comparative example.
In addition, a plurality of grooves having a depth of 0.05 mm were formed at both end faces in the short direction of the light guide at positions corresponding to the letter “E”, and the light guide sample of Example 1 was obtained.
Further, the light guide sample obtained in Example 1 is subjected to a blasting process in which a blast material is sprayed on both end surfaces in the short direction of the light guide at positions corresponding to the letter “E”. A light sample was obtained.

[Test method]
A reflective film is placed on the bottom plate, a light guide sample is placed on the reflective film, two LEDs (Nichia's NESW008) are placed near the longitudinal end face of the light guide sample, and a cover is placed. A light emitting device was formed by attaching to the bottom plate. This light-emitting device was placed in a dark room environment of 0.16 lx (measured with a illuminometer im-3 from TOPCON), a current of 20 mA was passed through each LED, and all the LEDs were turned on. Then, the luminance at three locations facing the longitudinal direction at the upper, middle and lower portions of the letter “E” at a height of 700 mm from the light emitting surface was measured with a liquid crystal color distribution measuring apparatus CA1000 manufactured by Minolta.

表に示すように、輝度は、文字「Ｅ」の上部、中間部、下部いずれも、比較例、実施例１、実施例２の順に大きくなった。従って、本発明の発光装置は導光体の短手方向の端面を粗面化することにより意匠の長手方向に沿った部分が明るくなることが確認された。 Table 1 shows the measurement results of luminance.

As shown in the table, the luminance increased in the order of Comparative Example, Example 1, and Example 2 in the upper part, middle part, and lower part of the letter “E”. Therefore, in the light emitting device of the present invention, it was confirmed that the portion along the longitudinal direction of the design is brightened by roughening the end face in the short direction of the light guide.

FIG. 10 shows the result of measuring the luminance of the upper part of the letter “E” of the light guide by changing the measurement position in the longitudinal direction. Note that the measurement positions 4 to 13 overlap with the letter “E”. The smaller the measurement position number is, the farther left from the letter “E” is, and the larger the measurement position number is 14, the more the character “E” is. Indicates that you are going to the right.
As shown in the figure, in the comparative example, the luminance was high at the left and right end portions of “E”, whereas the luminance was low at the middle portion of “E”, resulting in an unnatural display. On the other hand, in the example, the brightness of the middle part of “E” was higher than that of the comparative example, and the brightness of the left and right end parts of “E” was lower than that of the comparative example. In addition, the luminance of the middle portion of “E” was higher than the luminance of the left and right end portions of “E”. Therefore, it was confirmed that the light-emitting device of the present invention appropriately brightens the portion along the longitudinal direction of the design by roughening the end face of the light guide in the short direction.

  Furthermore, as shown in Table 1 and FIG. 10, the end surface in the short direction of the light guide is roughened by grooves and blasting, and the end surface in the short direction of the light guide is roughened only by the grooves. It was confirmed that the portion along the longitudinal direction of the design was appropriately brighter than the case where it was converted.

As described above, according to the present invention, it is possible to brighten the portion along the longitudinal direction of the design by various aspects.
In addition, when roughening the end surface in the short direction of the light guide, only one of both end surfaces in the short direction may be roughened. Further, one end surface and the other end surface in the short direction may be roughened in different modes.
Furthermore, the present invention is not limited to the above-described embodiments and modifications, and the configurations disclosed in the above-described embodiments and modifications are mutually replaced, the combinations are changed, the known technology, and the above-described configurations. Configurations in which the respective configurations disclosed in the embodiments and modifications are mutually replaced or combinations thereof are also included.

The principal part perspective view which shows an example of the interior of the motor vehicle which employ | adopted the light-emitting device. The top view which shows an example of a light-emitting device seeing from the light emission surface side. FIG. 3 is a vertical sectional view showing the light emitting device shown in FIG. The top view which shows an example of a reflective film. FIG. 3 is a vertical cross-sectional view illustrating various light-emitting devices in cross-section at the position A2-A2 in FIG. The principal part top view which illustrates the principal part of various light guides seeing from the light emission surface side. The principal part top view which illustrates the principal part of various light guides seeing from the light emission surface side. The principal part top view which shows the principal part of the light guide which concerns on a modification, seeing from the light emission surface side. The figure which illustrates typically a blasting apparatus. The figure of the graph format which shows the result of having changed the measurement position to the longitudinal direction about the upper part of the letter "E" of a light guide, and measuring the brightness | luminance. The figure which shows the vertical cross section of the scuff plate light-emitting device concerning a prior art example. The top view which shows the prior art example of a scuff plate light-emitting device seeing from the light emission surface side.

Explanation of symbols

1 ... scuff plate,
10, 10a to 10d ... light emitting device for automobile,
20, 20a-20i ... light guide, 21 ... light emitting surface, 22 ... back surface,
23, 24 ... end faces in the longitudinal direction, 25, 26 ... end faces in the short direction, 27 ... notches,
30 ... dent, 31 ... part along the longitudinal direction, 32 ... part along the transversal direction,
40, 41, 42, 44a ... rough surface part,
42a ... intermediate portion, 42b ... both end portions,
43, 44b, 45-49 ... groove, 45a, 45b, 46a ... incident end face facing portion,
47a ... first groove, 47b ... second groove, 47c ... third groove, 47d ... fourth groove,
48a ... fifth groove, 48b ... sixth groove,
60 ... light source unit, 62 ... light source,
72 ... bottom plate, 74 ... cover, 76 ... reflective film,
81 ... Door opening, 82 ... Front seat, 83 ... Rear seat, 84 ... Door,
D1: Longitudinal direction of the light guide, D2: Short direction of the light guide, D3: Thickness direction of the light guide,
D4: Center of incident light traveling direction, D5: Example of reflected light traveling direction,

Claims (8)

A recess for displaying the design is formed on the back surface, and a plate-shaped light guide for displaying the design from the light emitting surface opposite to the back surface based on incident light from the end face in the longitudinal direction;
A light source for allowing light to enter the longitudinal end face of the light guide,
A light emitting device for an automobile, wherein at least a part of an end surface in a short side direction of the light guide is roughened.   The light emitting device for an automobile according to claim 1, wherein at least a part of an end surface in the short direction of the light guide is roughened by blasting.   At least a part of the end surface is roughened by arranging a plurality of grooves in the longitudinal direction in a direction connecting the back surface and the light emitting surface to at least a part of the end surface in the short direction of the light guide. The light emitting device for automobiles according to claim 1 or 2, wherein the light emitting device is used.   The groove is recessed substantially in a V shape from the end surface in the short direction, and a portion facing the end surface where light enters from the light source is at an angle greater than 0 ° and 45 ° or less from the end surface in the short direction. The light emitting device for an automobile according to claim 3, wherein the light emitting device is inclined toward the inside of the light body. The plurality of grooves include at least first and second grooves adjacent to each other in the longitudinal direction, and at least third and fourth grooves closer to the light source than the first and second grooves. And
5. The automobile light-emitting device according to claim 3, wherein a distance between the first groove and the second groove is narrower than a distance between the third groove and the fourth groove. apparatus. The plurality of grooves include at least a fifth groove and a sixth groove closer to the light source than the fifth groove,
The light emitting device for an automobile according to any one of claims 3 to 5, wherein the fifth groove is deeper than the sixth groove.   A plurality of the recesses are arranged in the longitudinal direction on the back surface of the light guide, and the end surface in the short direction of the light guide is roughened at a position corresponding to each of these recesses. The light-emitting device for motor vehicles as described in any one of Claims 1-6.   The end face in the short direction of the light guide is roughened by blasting at a position corresponding to each of the plurality of recesses, and blasting of the intermediate portion in the longitudinal direction is performed on the long side in each roughened portion. The light emitting device for an automobile according to claim 7, wherein the light emitting device is stronger than the blast treatment at both ends in the direction.

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