JPH0524478A - Vehicular lighting tool - Google Patents

Abstract

PURPOSE:To provide a vehicular lighting tool which has a long narrow brightness surface and is hardly causing nonuniformity in brightness and is formed in a small sized simple structure. CONSTITUTION:A vehicular lighting fixture is constituted of a transparent long narrow bar shape photoconductor 2 which can conduct light inside and has plural number of total reflection steps arranged in parallel in the lengthwise direction on its back face, a long narrow lighting fixture body 1 to enclose this bar shape photoconductor, a light source unit 4 to conduct light inside the bar shape photoconductor from at least a base edge part and an outer lens 3 fixed to the front opening of the lighting fixture body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular lamp, and more particularly to a vehicular lamp suitable for application to a lamp having an elongated luminance surface.

[0002]

2. Description of the Related Art In recent years, a lamp used as a high mount stop lamp of an automobile is constructed as a lamp having a long and slender luminance surface. For this type of lighting,
Although a structure in which a large number of light emitting diodes are arranged in the lateral direction has been proposed, it is difficult to obtain high brightness. In this respect, a light source using a light bulb can easily obtain high brightness. For example, FIG. 10 is a vertical cross-sectional view of an example of a conventional high mount stop lamp, in which a light bulb socket 22 is used to support a light bulb 23 in a horizontally elongated lamp body 21 and a front opening of the lamp body 21 is provided. An elongated outer lens 24 is fixed laterally. And
In order to make the light from the light bulb 23 uniform in the outer lens 24, the inner surface of the lamp body 21 is configured as a reflecting surface, and the inner lens 25 having a diffusion step is arranged inside the lamp body.

[0003]

In such a conventional lamp, the vertical dimension of the lamp body 21 cannot be made smaller than that of the light bulb 23, and the vertical dimension of the lamp is reduced to reduce the size. There is a limit to this, and it is difficult to construct a lamp having a linear luminance surface. It is also difficult to dispose such a lamp in a rear spoiler or the like.
Further, in order to make the light of the light bulb 23 uniform, the inner lens 25 having a diffusion step is indispensable, which complicates the structure of the lamp, and the inner lens 25 alone makes the light of the light bulb uniform in the longitudinal direction. Is extremely difficult in practice, and there is also a problem that luminance unevenness easily occurs in the longitudinal direction. An object of the present invention is to provide a vehicular lamp which has an elongated luminance surface such as a high mount stop lamp, has no luminance unevenness, and has a small size and a simple structure.

[0004]

The vehicle lamp of the present invention comprises:
A transparent elongated rod-shaped photoconductor having a plurality of total reflection steps arranged in the length direction on the back surface thereof, which is capable of conducting light, an elongated lamp body containing the rod-shaped photoconductor, and a rod-shaped light conducting member. It is composed of a light source part for introducing light into the body from at least the base end part, and an outer lens fixed to the front opening of the lamp body. Here, in the total reflection step, the step size is gradually increased from the base end portion to the tip end portion of the rod-shaped photoconductor. Further, a reflection film is formed on the tip surface of the rod-shaped photoconductor, and the total reflection step has a shape of totally reflecting the light from both the base end portion and the tip portion, and the step size of each total reflection step is made equal. .

[0005]

According to the present invention, the light transmitted through the rod-shaped photoconductor is equally reflected in the right angle direction by the total reflection step and emitted from the rod-shaped photoconductor, and is substantially equal over the lengthwise direction of the rod-shaped photoconductor. Illumination with brightness is possible.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. 1 is a partially exploded perspective view of an embodiment of the present invention, FIG. 2 is a perspective view of its assembled state, and FIG. 3 is a sectional view taken along the line AA of FIG. In these drawings, reference numeral 1 denotes an elongated lamp body, and in particular, a front opening 1a thereof has an extremely small vertical dimension. A rod-shaped photoconductor 2 is provided inside the lamp body 1, and an elongated outer lens 3 is fixed to the front opening 1a. The outer lens 3 has a peripheral edge portion sealed with a sealant in a seal groove 1c provided on the peripheral edge of the lamp body 1. or,
A side opening 1b having a diameter substantially equal to the outer diameter of the rod-shaped photoconductor 2 is formed on one end surface of the lamp body 1, and the rod-shaped photoconductor 2 is inserted into the lamp body 1 through the side opening 1b. ing. The rod-shaped photoconductor 2 is provided with a light source portion 4 at the base end portion, and the light source portion 4 is attached to one end surface of the lamp body 1 so as to close the side surface opening 1b. The lamp body 1 has a paraboloidal cross section, and an inner surface thereof is configured as a reflecting surface 5, and the rod-shaped photoconductor 2 is arranged at a focal position of the reflecting surface 5.

As shown in FIGS. 4 and 5, the rod-shaped photoconductor 2 is made by forming a photoconductive material such as a transparent resin into a round bar shape and is installed inside the lamp body. Total reflection steps 6 are formed at a plurality of positions in the longitudinal direction on the front side facing the opening 1a. This total reflection step 6 is composed of a concave portion having a sawtooth cross section, and totally reflects the light transmitted from the base side inside the rod-shaped photoconductor 2 in the direction perpendicular to the back side of the rod-shaped photoconductor. It is configured to let. Further, in this example, the total reflection step 6 is configured such that the step size gradually increases from the base end side to the tip end side of the rod-shaped photoconductor 2.

As shown in FIG. 6, the light source unit 4 connected to the base end of the rod-shaped photoconductor 2 has a light bulb 8 in a housing 7 having a vertical dimension and a depth dimension substantially equal to those of the lamp body 1. The reflecting mirror 9 and the lens 10 are integrally incorporated, and the base portion of the rod-shaped photoconductor 2 is located at one side surface thereof for insertion. Therefore, the light from the light bulb 8 is condensed by the reflecting mirror 9, and this light is introduced from the base end portion of the rod-shaped photoconductor 2 into the inside thereof and conducted toward the tip portion of the rod-shaped photoconductor 2. Is possible. Further, the outer lens 3 is formed of a transparent resin or the like which is colored in a desired color, and a diffusion step for slightly diffusing light in the vertical direction and the horizontal direction is integrally formed on the inner surface, and at the peripheral portion thereof, It is fixed to the lamp body 1.

According to the lamp having this structure, in the light source section 4, the light emitted from the light bulb 8 is condensed by the reflecting mirror 9,
It is introduced into the base end portion of the rod-shaped photoconductor 2 through the lens 10. This light is transmitted to the tip while repeating internal reflection on the peripheral surface of the rod-shaped photoconductor 2. The light radiated to the total reflection step 6 on the way is the rod-shaped photoconductor 2
The reflection surface 5 of the lamp body 1 is reflected toward the back of the lamp body 1.
After being reflected by, the light is made into parallel light, and is slightly diffused by the outer lens 3 and emitted as illumination light. At this time, since the intensity of the light conducted inside the rod-shaped photoconductor 2 is gradually reduced toward the tip of the rod-shaped photoconductor, the total reflection step 6 on the tip side is performed at the base end. By making the step size larger than that on the side, the amount of light reflected in the total reflection step on the tip side is increased, and thereby substantially uniform reflected light is obtained over the length direction of the rod-shaped photoconductor 2. Therefore, the luminance in the length direction of the outer lens 3 can be made uniform.

Therefore, according to this lamp, the vertical dimensions of the lamp body 1 and the outer lens 3 can be made as small as the diameter of the rod-shaped photoconductor 2, and the linear dimension is very small. It can be configured as a lamp for performing illumination. As a result, it can be applied to a rear spoiler of an automobile as a high mount stop lamp. In addition, since the total reflection step 6 provided on the rod-shaped photoconductor 2 can obtain a substantially uniform light reflection characteristic in the length direction, it is possible to illuminate with a uniform brightness without using an inner lens, and the lamp structure It is possible to simplify.

FIG. 7 is a sectional view showing another example of the rod-shaped photoconductor. In this embodiment, the reflection film 11 is formed on the tip surface of the rod-shaped photoconductor 2A, and the light from the base end portion is reflected by the reflection film 11 at the tip end toward the base end side. Further, the total reflection step 6A is configured as an isosceles triangular concave portion so that total reflection is performed on both surfaces, and all the total reflection steps 6A are formed to have the same size. In this configuration, when light is conducted from the base end portion to the tip end portion in the rod-shaped photoconductor 2, the light is reflected by the surface on the base end side of each total reflection step 6A and is reflected by the reflection film 11. When the light propagates from the distal end portion to the proximal end portion, it is reflected again on the distal end side surface of each total reflection step 6A. Therefore, even if the reflection amount of the outgoing light and the reflection amount of the returning light are gradually reduced in each total reflection step 6A, as a result, the total reflection amount of the light in all the total reflection steps 6A is substantially equal. Therefore, it is possible to obtain uniform light reflection characteristics.

FIGS. 8A and 8B are external views showing another example of the present invention. In the example of FIG. 8A, the base end portion of the rod-shaped photoconductor and the light source portion 4 are bent and formed at a right angle. They are connected by the photoconductor 12. The bent portion 12a of the photoconductor 12 is formed as a 45-degree slope, and a reflection film is formed on the slope 12a. With this configuration, the light source unit 4 can be disposed at the rear position of the lamp body 1, and a non-light emitting portion such as a light source unit is disposed on one side of the front surface of the lamp as in the above-described embodiment. It is possible to prevent the appearance from being deteriorated. In the example of (b), a flexible light guide 13 such as an optical fiber bundle is connected to the base end of the rod-shaped photoconductor, and the light guide 4 is connected to the light guide 13 via the light guide 13. In this configuration, the light source unit 4
A can be installed at a position distant from the lamp body 1, which is advantageous in terms of appearance as in the case of (a), and the degree of freedom in the arrangement position of the lamp can be increased.

As shown in FIG. 9, a halogen lamp 15, a heat ray reflection / absorption filter 16 and a functional color filter 17 are provided in a housing 14 as a light source section 4A used in the structure of FIG. 8B. In addition, a connector (socket) 18 supporting one end of the light guide 13 is fitted into the front opening 14a of the housing. In this configuration, the light emitted from the halogen lamp 15 is reflected by the reflection surface, and the heat ray reflection / absorption filter 16 is provided.
The temperature of the light is reduced by the functional color filter 17, and the light of a predetermined color is converted by the functional color filter 17 and then condensed at one end of the light guide 13 and introduced into the light guide 13. This light is transmitted through the light guide 13 and then introduced at the other end of the light guide 13 to the base end of the rod-shaped photoconductor connected by a connection structure (not shown). By providing the functional color filter in the light source section in this way, it becomes possible to illuminate the required color light even if a colorless outer lens is used.

[0014]

As described above, according to the present invention, a plurality of total reflection steps are provided on the back surface of the rod-shaped photoconductor so that light is conducted to the inside from at least the base end side of the rod-shaped photoconductor. Therefore, the light conducted in the rod-shaped photoconductor is equally reflected in the right angle direction by the total reflection step and emitted from the rod-shaped photoconductor, and the light is approximately equal in the length direction of the rod-shaped photoconductor. Illumination with brightness is possible. As a result, it is possible to construct a lamp having an extremely small vertical dimension that is comparable to the shape of the rod-shaped photoconductor, and it is possible to reduce the size of the lamp. Further, an inner lens for uniformizing the luminance in the length direction is not required, and the lamp structure can be simplified.

[Brief description of drawings]

FIG. 1 is a partially exploded perspective view of an embodiment of a vehicular lamp of the present invention.

FIG. 2 is an external perspective view of the lamp of FIG.

3 is a sectional view taken along the line AA of FIG.

FIG. 4 is a perspective view of the rod-shaped photoconductor from the front direction.

FIG. 5 is a cross-sectional view for explaining the conduction and reflection states of light in a rod-shaped photoconductor.

FIG. 6 is a cross-sectional view of a light source unit.

FIG. 7 is a cross-sectional view of another rod-shaped photoconductor.

8A and 8B are external perspective views of another embodiment of the present invention.

FIG. 9 is a cross-sectional view of another example of the light source section.

FIG. 10 is a sectional view of an example of a conventional high mount stop lamp.

[Explanation of symbols]

1 lighting body 2 Rod-shaped photoconductor 3 outer lens 4,4A light source 6,6A Total reflection step 12 Photoconductor 13 Light guide

Claims (3)

[Claims] 1. A transparent elongated rod-shaped photoconductor having a plurality of total reflection steps arranged in the length direction on the back surface thereof, which is capable of conducting light, and an elongated lamp body having the rod-shaped photoconductor housed therein. And a light source unit for introducing light into the rod-shaped photoconductor from at least a base end portion thereof, and an outer lens fixed to a front opening of the lamp body. 2. The vehicular lamp according to claim 1, wherein the total reflection step is such that the step size is gradually increased from the base end portion to the tip end portion of the rod-shaped photoconductor. 3. A rod-shaped photoconductor is provided with a reflection film on the tip surface thereof, and the total reflection step has a shape of totally reflecting the light from both the base end portion and the tip end portion, and the step size of the total reflection step is respectively set. The vehicle lighting device according to claim 1, wherein the lighting devices are equal.