JPH11201782A - Illumination structure of instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination structure of an instrument preventing a light leak from a reflecting face and having improved luminance of a pointer by providing a reflecting wall covering the reflecting face of the pointer shaft insertion hole of a light guide plate on a light guide plate case. SOLUTION: A light guide plate 1 is stored in a light guide plate case 2, a pointer shaft insertion hole 9 having a reflecting face 8 is formed on the light guide plate 1, and the light from a light source 3 arranged at the edge of the light guide plate 1 is reflected on the reflecting face 8 to illuminate a pointer 10 on the light guide plate 1 in this illumination structure of an instrument. The light guide plate case 2 is extended at the portion of the reflecting face 8 to form a reflecting wall 2a covering the reflecting face 8, and the light tending to leak from the reflecting face 8 is stopped by the reflecting wall 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting structure for an instrument, and more particularly, to a lighting structure for illuminating a pointer by guiding light from a light source with a light guide plate.

[0002]

2. Description of the Related Art A so-called edge light type illumination structure in which a light source is arranged to face a side end surface of a light guide plate, light is introduced into the light guide plate, and the light is reflected by a substantially conical reflecting surface to illuminate a pointer. In order to prevent light from leaking from the light guide plate, a structure in which the light guide plate is housed in a light guide plate case is known. That is, in FIG. 3, the light guide plate 1 is housed in the light guide plate case 2 and closed except for the upper surface, and the dial 6 is attached to the upper surface. A substantially conical pointer shaft insertion hole 9 is formed in the light guide plate 1, and the inner peripheral surface thereof is used as a reflection surface 8.

As shown in FIG. 4, the reflecting surface 8 is composed of a plurality of inclined surfaces 8a having slightly different inclination angles, and on both sides of the reflecting surface 8 with respect to the light source 3 and the reflecting surface 8. Slits 11, 11 inclined at a certain angle are formed. The pointer shaft 7a of the inner machine 7 protrudes from the pointer shaft insertion hole 9 provided with the reflection surface 8 to the upper surface of the dial 6, and a pointer 10 is attached to the tip thereof.

The light source (cold cathode ray tube in the illustrated example) 3 is attached to the side of the light guide plate 1. The light source 3
In addition to cold cathode ray tubes, bulbs, LEDs, and other light sources are used. The light emitted from the light source 3 is
The light directly reaches the reflecting surface 8 or is reflected by the slit 11 and reaches the reflecting surface 8 from the side, and both are reflected by the reflecting surface 8 to illuminate the hands 10.

[0005]

The light emitted from the light source 3 is reflected by the reflecting surface 8 to illuminate the pointer 10, but a part of the light L (see FIG. 3) is not reflected but passes through the pointer shaft. There is a problem that the light leaks into the hole 9 and does not contribute to the illumination of the pointer, and the brightness of the pointer 10 decreases accordingly.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points. By providing a light guide plate case with a reflection wall for covering the reflection surface of the pointer shaft insertion hole of the light guide plate, light leakage from the reflection surface is prevented. It is an object of the present invention to provide a lighting structure of an instrument in which the brightness of a pointer is improved.

[0007]

According to a first aspect of the present invention, there is provided a light guide plate having a light guide plate housed in a light guide plate case, the light guide plate having a substantially conical shape having a reflection surface. A pointer shaft insertion hole is formed, wherein the light from the light source is guided by the light guide plate and is reflected by the reflection surface to illuminate the pointer on the light guide plate, wherein the reflection structure is provided. The light guide plate case is extended in a surface portion to form a reflection wall that covers the reflection surface.

For this reason, in the first aspect of the present invention, the light emitted from the light source is reflected by the reflecting surface to illuminate the pointer, but a part of the light tends to leak without being reflected by the reflecting surface. The light that is about to leak from the reflecting surface is stopped by the reflecting wall and reflected in the direction of the pointer, and the brightness of the pointer is increased by effectively using all the light.

According to a second aspect of the present invention, there is provided the illumination structure of the instrument according to the first aspect, wherein a gap is provided between the reflecting surface and the reflecting wall. .

Therefore, according to the second aspect of the present invention, it is possible to absorb a shift caused by a difference in thermal expansion between the optical waveguide and the optical waveguide case.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. The same members or those having the same functions as those in FIG. 3 are denoted by the same reference numerals.

In FIG. 1, a facing 4 is attached to the upper part of the meter case 12, and the facing 4 is attached to the facing 4.
Is attached. Inside the meter case 12
The light guide plate 1 is disposed above the inner unit 7.

The light guide plate 1 is accommodated in a light guide plate case 2 and a dial 6 is mounted on the upper surface. A pointer insertion hole 9 having a substantially conical reflection surface 8 is formed in the light guide plate 1, and a pointer shaft 7 a of the inner unit 7 protrudes from the pointer shaft insertion hole 9 to the upper surface of the dial 6, and a pointer 10 Is attached.

A light source (cold cathode ray tube in the illustrated example) 3 is attached to the side of the light guide plate 1. The light source 3 is attached to the cold cathode ray tube cover 13 and
Reference numeral 3 is attached to a side end of the light guide plate case 2. In addition, as a light source of the edge light, a bulb, an LED, or any other light source can be used in addition to a cold cathode ray tube, and those shown in the drawings are merely examples.

In the present invention, the light guide plate case 2 located at the reflection surface 8 is extended to provide the reflection wall 2 a so as to cover the reflection surface 8. As a result, light that is about to leak from the reflecting surface 8 is stopped by the reflecting wall 2a and reflected in the direction of the pointer 10, and the brightness of the pointer 10 is increased by effectively using all the light (see FIG. 2). .

It is preferable to provide a desired gap G between the reflecting surface 8 and the reflecting wall 2a as shown in FIG. This is because the gap G absorbs a shift due to a difference in thermal expansion between the light guide plate 1 and the light guide plate case 2.

As described above, in the lighting structure of the instrument according to the present embodiment, the light guide plate case 2 is extended and the reflecting wall 2 a is provided so as to cover the reflecting surface 8, so that the light may leak from the reflecting surface 8. Is stopped by the reflecting wall 2a and reflected in the direction of the pointer 10, and all the light can be used effectively.
Of the image is improved.

[0018]

As described above in detail, according to the first aspect of the present invention, the light guide plate case is extended to form the reflection wall that covers the reflection surface of the pointer shaft insertion hole. The light to be leaked is stopped by the reflecting wall and reflected in the direction of the pointer, and all the light can be used effectively, so that the brightness of the pointer is improved and the light guide plate case is integrally formed with the reflecting wall. , The configuration is simple, and the luminance is improved at low cost.

According to the second aspect of the present invention, since the gap is provided between the reflecting surface and the reflecting wall, a deviation due to a difference in thermal expansion between the light guide plate and the light guide plate case can be absorbed, and the light guide plate can be absorbed. Deformation can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing an embodiment of a lighting structure of an instrument of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the above.

FIG. 3 is a cross-sectional view of a main part of a conventional instrument lighting structure.

FIG. 4 is a rear view of the light guide plate of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light guide plate 2 Light guide plate case 2a Reflection wall 3 Light source 8 Reflection surface 9 Pointer shaft insertion hole 10 Pointer G Gap

Claims (2)

[Claims] 1. A light guide plate housed in a light guide plate case, a substantially conical pointer insertion hole having a reflection surface is formed in the light guide plate, and light from a light source is guided by the light guide plate. And an illumination structure for an instrument that reflects light from the reflection surface to illuminate the pointer on the light guide plate, wherein the light guide plate case is extended at the reflection surface portion to cover the reflection surface. A lighting structure for an instrument, wherein a wall is formed. 2. An illumination structure for an instrument according to claim 1, wherein a gap is provided between said reflection surface and said reflection wall.