JP6619584B2 - Light guide - Google Patents

Description

  The present invention relates to a light guide that emits light by reflecting light incident from a light source.

  For example, LEDs (light emitting diodes) having advantages such as high luminous efficiency, high luminance, and power saving are being used as light sources for vehicle lamps such as position lamps arranged on the left and right sides of the vehicle. Since light with strong directivity is emitted from this LED, the light with strong directivity is guided to the light guide and the entire light guide is emitted. That is, the light guide emits light by being reflected by the reflecting surface and emitted from the emitting surface in the process of guiding the light incident from the incident surface facing the light source inside.

  By the way, in Patent Document 1, for example, a flat light guide is used, and light emitted from a light source whose optical axis extends in the vertical direction with respect to a horizontally installed light guide plate is reflected with respect to the optical axis. The light guide is formed with a reflection surface that radially reflects in an orthogonal direction, and a reflection surface that reflects the horizontal light reflected left and right by the reflection surface toward an elongated rectangular emission surface on the front side. A light emitting device that emits light on a long and slender exit surface has been proposed.

  Here, an example of a plate-shaped light guide used for a vehicle lamp such as a position lamp is shown in FIG.

  That is, FIG. 8 is a partial plan view showing an example of a conventional light guide. A plurality of optical systems 102 (only two are shown in FIG. 8) are arranged in a horizontal direction in the plate-like light guide 101 shown in the figure. They are arranged in parallel at appropriate intervals. Then, on the back side of each optical system of the light guide (on the back side in FIG. 8), a light source (not shown) such as an LED is arranged so that its optical axis is orthogonal to the plane of the light guide 101. Has been placed. Each optical system 102 has a truncated cone-shaped first reflecting surface (not shown) that reflects light emitted from the light source in the optical axis direction of the light source, and light reflected by the first reflecting surface. A V-cut second reflecting surface 106 that reflects in a direction perpendicular to the axis, and a third arc-shaped third reflecting surface that reflects the light reflected by the second reflecting surface 106 in parallel toward the elongated outgoing surface 109 on the front side. A reflecting surface 107 is provided, and the arc-shaped third reflecting surfaces 107 of two adjacent optical systems 102 are connected to each other by a V-shaped inclined surface 108.

  In such a light guide 101, when light sources provided corresponding to the respective optical systems 102 emit light, the light emitted from each light source is transmitted through first and second reflecting surfaces (not shown) of the light guide 101. 106 and the third reflecting surface 107 are reflected to emit horizontal light from the emitting surface 109, so that the emitting surface 109 of the light guide 101 emits light in an elongated manner.

Japanese Patent No. 4458359

  However, in the conventional light guide 101 shown in FIG. 8, the limits of the light that is reflected by the third reflecting surfaces 107 of the two adjacent optical systems 102 and travels toward the exit surface 109 are L1 and L2 as shown. The portion between them becomes dark when viewed from the front, and the entire light guide 101 does not emit light uniformly.

  The present invention has been made in view of the above problems, and an object thereof is to provide a light guide that emits light uniformly throughout.

In order to achieve the above object, the invention described in claim 1 includes a plurality of optical systems including an incident surface and a plurality of reflecting surfaces that reflect light incident from the incident surface and emit the light from the exit surface, and are adjacent to each other. In a plate-shaped light guide formed by connecting arc-shaped reflective surfaces of an optical system with V-shaped inclined surfaces, the emission surface is formed on a plate-shaped side surface of the light guide, and the incident The surface is formed on the front surface or the back surface of the light guide so that the light emitted from the light source is incident, and the plurality of reflecting surfaces are located on the same surface or the back surface as the incident surface, and the light emitted from the light source. Is a frustoconical first reflecting surface that reflects the light in the optical axis direction of the light source, and is located at a location facing the incident surface and the first reflecting surface, and the light reflected by the first reflecting surface of the light source A V-cut second reflecting surface that reflects in a direction perpendicular to the optical axis, and the second It is composed of an arc-shaped third reflecting surface that reflects light reflected by the emitting surface in parallel toward the exit surface, and the arc-shaped third reflecting surfaces of two adjacent optical systems are: The V-shaped slopes are connected to each other, a stepped portion is integrally formed at the V-shaped tip portion of the V-shaped slope, and reflected light is reflected on a part of the second reflecting surface. A reflection part that reflects a part of the reflection toward the stepped convex part is formed.

The invention according to claim 2 is a vehicular lamp including the light guide according to claim 1 and a plurality of the light sources arranged corresponding to each of the plurality of optical systems. The light source is an LED, the plurality of optical systems are arranged side by side in a lateral direction, and the light exit surface of the light guide is a light exit surface that is long in the lateral direction. is there.

  According to the present invention, a step is formed on a part of the V-shaped slope connecting the arc-shaped reflecting surfaces (third reflecting surfaces) provided in two adjacent optical systems arranged in parallel to the light guide. In addition to forming the convex portion and forming a reflective portion that reflects part of the reflected light toward the stepped convex portion on a part of the reflective surface (second reflective surface) of each optical system, the two optical systems The limits of the light reflected by each reflecting surface (third reflecting surface) and going toward the exit surface approach each other, and the width of the dark portion between them becomes narrow. For this reason, the effect that the whole light guide emits light uniformly is acquired.

It is a top view of the light guide which concerns on this invention. It is a front view of the light guide which concerns on this invention. It is the A section enlarged detail drawing of FIG. It is the B section enlarged detail drawing of FIG. FIG. 4 is an enlarged detail view of a C part in FIG. 3. It is the DD sectional view taken on the line of FIG. It is the EE sectional view taken on the line of FIG. It is a partial top view of the conventional light guide.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 is a plan view of a light guide according to the present invention, FIG. 2 is a front view of the light guide, FIG. 3 is an enlarged detail view of part A in FIG. 1, FIG. 4 is an enlarged detail view of part B in FIG. 5 is an enlarged detail view of a portion C in FIG. 3, FIG. 6 is a sectional view taken along line DD in FIG. 4, and FIG. 7 is a sectional view taken along line EE in FIG.

  A light guide 1 shown in FIGS. 1 and 2 is a plate-like member that is long in the lateral direction and is used as an inner lens of a position lamp, and has an end portion (the right end of FIGS. 1 and 2 in plan view and front view). Part) has a bent shape. The light guide 1 is integrally formed of a material having high light guide properties such as acrylic and polycarbonate, and a plurality (10 in the illustrated example) of optical systems 2 are arranged in parallel at appropriate intervals. It is installed.

  Here, as shown in FIG. 6, LEDs 3 that are light sources are arranged corresponding to the respective optical systems 2 on the back surface side (the lower surface side of FIG. 2) of the light guide 1. The optical axis x is installed vertically in a direction in which it is in the vertical direction. And on the back surface facing the LED 3 of the light guide 1, a truncated cone-shaped convex portion 1 </ b> A is integrally projected downward for each optical system 2, and the side surface of the convex portion 1 </ b> A is convex. The curved first reflecting surface 4 is provided. A concave groove-shaped incident surface 5 is formed at the center of the lower portion of each frustoconical convex portion 1A.

  Further, as shown in FIG. 6, a V-cut second reflecting surface is provided at a position facing the incident surface 5 and the first reflecting surface 4 of each optical system 2 on the surface of the light guide 1 (upper surface in FIG. 6). 6 is formed, and a third arc-shaped third reflecting surface 7 is formed on a part of the outside of the second reflecting surface 6. Each optical system 2 includes the incident surface 5 and the first reflecting surface. The surface 4, the second reflection surface 6, and the third reflection surface 7 are included. As shown in FIGS. 1 and 3, the arc-shaped third reflecting surfaces 7 of the two adjacent optical systems 2 are connected to each other by a V-shaped inclined surface 8. In the present embodiment, As shown in FIGS. 3, 5, and 7, a stepped portion 8 a is integrally formed on a part of the V-shaped slope 8 (V-shaped tip portion).

  On the other hand, as shown in FIGS. 3 and 5, a part of the second reflecting surface 6 constituting each optical system 2 of the light guide 1 has a V-shaped slope as shown in FIGS. A reflecting portion 6 a that reflects light toward the stepped convex portion 8 a formed in a part of 8 is formed.

  As shown in FIGS. 1 to 4 and 7, the front surface of the light guide 1 is a long and narrow exit surface 9, and the exit surface 9 is provided with a lens cut for light distribution.

  Thus, in the light guide 1 configured as described above, when current is supplied to each LED 3 and each LED 3 emits light, the light emitted upward from each LED 3 is as shown in FIG. The light enters the light guide 1 from the incident surface 5 in each optical system 2 of the light guide 1. The light incident on the inside of the light guide 1 is reflected by the first reflecting surface 4 of each optical system 2 toward the optical axis x direction of the LED 3 (upward in FIG. 6). The reflective surface 6 reflects radially in a direction (horizontal direction) orthogonal to the optical axis x of the LED 3. A part of the light reflected by the second reflecting surface 6 is directly directed to the front-side emitting surface 9, and the other part is emitted from the third reflecting surface 7 at the front side as indicated by L in FIG. Since these lights are finally emitted from the emission surface 9 toward the front surface, the emission surface 9 that is elongated in the lateral direction emits light, and the position lamp including the light guide 1 has its original function. Demonstrate.

  By the way, in this Embodiment, a part of V-shaped slope 8 which connects the arc-shaped 3rd reflective surfaces 7 provided in two adjacent optical systems 2 arranged in parallel with the light guide 1 is connected. 7 is formed on the second reflecting surface 6 of each optical system 2, so that a part of the light reflected by the second reflecting surface 6 is as shown in FIG. The light is reflected by the reflecting portion 6a toward the stepped convex portion 8a of the inclined surface 8, reflected by the stepped convex portion 8a toward the light emitting surface 9 on the front side, and finally emitted from the light emitting surface 9 to the front side. As a result, as shown in FIG. 3, the limit of the light L1 toward the exit surface 9 in one of the two adjacent optical systems 2 (left side in FIG. 3) is the third in the optical system 2 in the other (right side in FIG. 3). It approaches the limit of the light L2 that is reflected by the reflecting surface 7 and travels toward the exit surface 9, and the width of the dark portion between the two becomes narrow. For this reason, the effect that the whole emission surface 9 of the light guide 1 emits light uniformly is obtained.

  In the above, the embodiment in which the present invention is applied to a light guide used as an inner lens of a position lamp has been described. However, the present invention also applies to a light guide used in any other lamp. Of course, it is applicable to. In the above embodiment, an LED is used as a light source. However, the present invention can be similarly applied to a light guide that emits light from light of an arbitrary light source other than an LED such as a bulb. .

DESCRIPTION OF SYMBOLS 1 Light guide 2 Optical system of light guide 3 LED (light source)
4 First reflective surface 5 Incident surface 6 Second reflective surface 6a Reflective portion of second reflective surface 7 Third reflective surface 8 Slope 8a Stepped portion of reflective surface 9 Emission surface L1, L2 Light x LED optical axis

Claims (2)

A plurality of optical systems including an incident surface and a plurality of reflecting surfaces that reflect light incident from the incident surface and emit from the exit surface are arranged side by side, and the arc-shaped reflecting surfaces of adjacent optical systems are V-shaped. In plate-shaped light guides that are connected by slopes,
The emission surface is formed on a plate-shaped side surface of the light guide,
The incident surface is formed on the front or back surface of the light guide so that light emitted from a light source enters,
The plurality of reflecting surfaces are located on the same surface or back surface as the incident surface, and a frustoconical first reflecting surface that reflects light emitted from the light source in the optical axis direction of the light source;
A V-cut second reflecting surface that is located at a position facing the incident surface and the first reflecting surface and reflects light reflected by the first reflecting surface in a direction perpendicular to the optical axis of the light source;
It is composed of an arc-shaped third reflecting surface that reflects the light reflected by the second reflecting surface in parallel toward the exit surface,
The arc-shaped third reflecting surfaces of two adjacent optical systems are connected by the V-shaped inclined surface, and a stepped convex portion is integrated with the V-shaped tip portion of the V-shaped inclined surface. Is formed,
A light guide body, wherein a reflection portion that reflects a part of reflected light toward the stepped convex portion is formed on a part of the second reflection surface . A light guide according to claim 1;
A plurality of the light sources arranged corresponding to each of the plurality of optical systems, and a vehicle lamp comprising:
The plurality of light sources are LEDs;
The plurality of optical systems are arranged side by side in the lateral direction,
The vehicular lamp according to claim 1, wherein an exit surface of the light guide is an exit surface that is long in a lateral direction.

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