JPH0915005A - Illumination device - Google Patents

Abstract

PURPOSE: To provide an illumination device wherein the number of photodetection sections is reduced by illuminating a plurality of positions by a single photodetection section so that a photoconductor is simplified and the designing of an optical path of the photoconductor is facilitated. CONSTITUTION: In the device, a pointer axle penetrates the central section of a roughly square dial plate 1 and a pointer made of a photoconductive member and a liquid crystal display device 6 for an electronic odometer are provided on the front face thereof. A photoconductor 7 is provided on the rear face of the dial plate 1. A photodetection section 7d that introduces a light from a light source 8, an illumination surface 7f that illuminates the liquid crystal display device 6 and a reflection section 7g that illuminates the pointer are formed in the photoconductor 7 dividedly in the thickness direction. The photodetection section 7d is commonly used and the optical passage is partially shared for illuminating the illumination surface 7f and reflection section 7g.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device having a light emitting pointer used for an instrument such as a speedometer or a tachometer of an automobile, and more particularly to an instrument having a transillumination display element in a part of the instrument. The lighting device used.

[0002]

2. Description of the Related Art Conventionally, illumination devices used for measuring instruments such as speedometers and tachometers are provided with various illuminations so that the measuring instruments can be read even in dark surroundings such as at night. As one method of such various types of illumination, there is a light emitting pointer that emits a pointer. This light emitting pointer illuminates the pointer by receiving light from a light source guided by a light guide made of a transparent synthetic resin or the like on a pointer base. In order to guide the light from the light source to the pointer, the light guide is arranged on the back surface of the dial. In order to irradiate and illuminate the entire rotation range of the pointer on the light guide body, a reflection surface is formed by appropriately dividing the entire rotation range, and an irradiation unit is formed above the reflection surface. Illuminates the pointer. The light guide body is provided with a plurality of light receiving portions corresponding to the reflecting surfaces.

Further, in an illuminating device used for an instrument including a transillumination type display element such as a transillumination type liquid crystal display device, illumination is performed by the light source provided behind the liquid crystal display device. . In order to illuminate the liquid crystal display device more effectively, the light from the light source is illuminated through the light guide, and the light from the light source is guided to the light guide. The light receiving section for taking in the light and the irradiation section for irradiating the liquid crystal display device were provided separately from the optical path for illuminating the pointer.

[0004]

Thus, in order to illuminate the pointer, the liquid crystal display device, and the like with one light guide, a plurality of light receiving portions are formed. For this reason, the shape of the light guide is complicated, and it is difficult to design the light guide, resulting in a cost increase. Further, since the number of light receiving portions is large, a shadow of the light receiving portion located on the back surface of the dial appears on the dial during illumination of the dial, which affects the illumination of the dial. Therefore, in consideration of the above-mentioned conventional example, the present invention provides an illuminating device in which a single light receiving unit illuminates a plurality of points to form a light guide having a simple shape, and an optical path of the light guide can be easily designed. It is provided.

[0005]

In order to solve the above-mentioned problems, a lighting device of the present invention has a dial which is partially provided with a transillumination type display element, and a pointer which is located in front of the dial and indicates rotation. A light source disposed on the back side of the dial and near the outer periphery of the dial, and light emitted from the light source disposed behind the dial to the pointer and the transillumination display element. A light-receiving portion for introducing the light of the light source and an irradiation surface for illuminating the transillumination display element and a reflecting portion for illuminating a pointer, and the irradiation surface and the reflecting portion are divided in the thickness direction. And a light guide formed by the process.

[0006]

With the above structure, the light from the light source is received by the same light receiving portion, and the irradiation surface and the reflecting portion are formed by being divided in the thickness direction, so that the pointer and the transillumination type display element are separately illuminated. . Further, since the light receiving section is common, a part of the optical path is common, the optical path of the light guide body can be easily designed, and the light guide body can have a simple shape. Further, by integrally forming the light receiving unit, it is possible to illuminate each unit without reducing the light amount of illumination.

[0007]

An embodiment of the present invention will be described below with reference to FIGS. A through hole 1a is formed at the center of the dial 1 having a substantially quadrangular shape, and a pointer shaft 3 of a pointer 2 is provided in a direction perpendicular to the dial 1 through the through hole 1a. The pointer shaft 3 is attached to the instrument body 4. When the pointer 2 is rotated by the instrument body 4 and read in contrast with the dial 1, the engine tachometer 5 which is the instrument of the present embodiment indicates and displays the engine speed.

The pointer 2 is made of a light guide member made of transparent synthetic resin, and is guided by the light incident from the pointer base 2a.
Is being illuminated.

In such an instrument 5, a dial 1 has a display window 1b for an electronic odometer, which is shown by a dotted line in FIG. 1, and is formed on the back side of the dial 1 corresponding to the display window 1b. A liquid crystal display device 6 which is a transillumination type display element forming an electronic odometer is provided. And this instrument 5
At the engine speed and the liquid crystal display device 6 according to the pointer 2
The mileage is displayed by and.

On the back surface of the dial 1, a light guide 7 made of transparent synthetic resin is arranged. The light guide body 7 guides light from light sources 8 arranged on the left and right in the vicinity of the outer periphery of the dial 1 to the pointer 2
And the liquid crystal display device 6. The portion of the light guide body 7 corresponding to the pointer base portion 2a illuminates the entire rotation range of the pointer 2, so that there is a problem when guiding light.
In order to design the optical path avoiding the mounting hole 7a for attaching the light guide 7 to the light guide 7, a plurality of reflecting surfaces 7b are formed below the pointer base 2a so that the light is reflected in the entire rotation range. An irradiation unit 7c is provided above the reflection surface 7b. In this embodiment, in order to avoid the mounting hole 7a, four optical paths are set, and the pointer rotation range is set to receive light from four directions. The reflecting surface 7b corresponds to the four optical paths. Has been formed. Further, the light guide body 7 is provided with a plurality of light receiving portions 7d corresponding to the reflecting surfaces 7b, and in the embodiment, four light receiving portions 7d are provided. Light guide 7 configured in this way
Thereby, the light entering from the light receiving portion 7d is reflected by the reflecting surface 7b, is guided to the pointer base portion 2a through the irradiation portion 7c, and is illuminated in the entire rotation range of the pointer 2.

A notch 7e is formed in the light guide 7 at a position corresponding to the display window 1b. The liquid crystal display device 6 is provided with a table-shaped liquid crystal holder 6a having four legs made of transparent synthetic resin, and a recess 6b is formed on the upper portion of the holder 6a. The semi-transmissive reflection plate 6c and the liquid crystal display element 6d are arranged in a laminated state and are covered with a cover 6e made of black synthetic resin.

The liquid crystal display device 6 is illuminated by receiving light from the light guide 7 at the light receiving portion 6f of the holder 6a which is not covered with the cover 6e. In order to illuminate the liquid crystal display device 6 with the light guide body 7, a curved irradiation surface 7f is provided on the back surface of the light guide body 7. Since the irradiation surface 7f is formed of a curved surface, even if the light receiving portion 6f of the liquid crystal display device 6 is irradiated with light from the right direction when viewed from the front, the liquid crystal display device 6 is uniformly irradiated with light. The light receiving portion 7d for guiding light to the irradiation surface 7f is formed integrally with the light receiving portion 7d provided for illuminating the pointer 2.

Therefore, the optical path for illuminating the pointer 2 is reflected by the reflecting section 7g near the upper side of the irradiation section 7f, guides the light to the reflecting surface 7b below the pointer base 2a, and illuminates the liquid crystal display device 6. The optical path for guiding the light to the irradiation surface 7f of the light guide 7 illuminates the liquid crystal display device 6.

As described above, the light receiving portion 7 used for illuminating the pointer 2.
By integrally forming d and the light receiving portion 7d used for illumination of the liquid crystal display device 6, the number of the light receiving portions 7d can be reduced, and the light guide can have a simple shape. In addition, since the irradiation portion 7f and the reflection surface 7g are divided and formed in the thickness direction, when the light guide 7 is viewed from the front, the optical path of the illumination of the pointer 2 and the optical path of the illumination of the liquid crystal display device 6 are formed. This is partly common, and the light guide 6 can be easily designed.

As described above, in this embodiment, the light receiving portion 7d of the light guide 7 for illuminating the pointer 2 and the liquid crystal display device 6 is integrally formed, and the optical path for illuminating the pointer 2 and the liquid crystal display device 6 is made uniform. It is common to all departments. Further, since the thickness is twice as large as that of the normal light receiving portion 7d, light can be efficiently received without reducing the amount of light received from the light source 2, and thus good illumination can be performed.

[0016]

As described above, the illumination of the pointer and the illumination of the liquid crystal display device are made to be the same light receiving portion, and a part of the common light path is used to reduce the number of light receiving portions provided in the light guide. Therefore, the shape of the light guide can be simplified, and the cost can be reduced.

Further, by reducing the number of light receiving portions, it is possible to obtain good illumination that does not affect the illumination of the dial. Further, since the light receiving portion has a thickness thicker than that of a normal light receiving portion, good illumination can be obtained without affecting the light amount.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment of the present invention.

FIG. 2 is a sectional view of a main part taken along the line AA in FIG.

FIG. 3 is a cross-sectional view of a main part taken along the line BB in FIG.

FIG. 4 is a rear view of the light guide body according to the embodiment.

[Explanation of symbols]

 1 dial 2 pointer 2a pointer base 3 pointer axis 5 instrument (engine tachometer) 6 liquid crystal display device 7 light guide 7d light receiving part 7f irradiation surface 7g reflecting part 8 light source

Claims (1)

[Claims] 1. A dial which is partly provided with a transillumination type display element, and a pointer which is located in front of the dial and indicates rotation.
A light source disposed on the back side of the dial and disposed near the outer periphery of the dial, and light from the light source disposed behind the dial is guided to the hands and the transillumination display element. Along with a light receiving section for taking in the light of the light source, an irradiation surface for illuminating the transillumination display element, and a reflecting section for illuminating a pointer, the irradiation surface and the reflecting section are divided in the thickness direction. A light guide, which comprises: