JPH10281823A - Lighting device for measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lighting device, for a measuring instrument, which eliminates light leaked to the front of a dial, which enhances the quality of the measuring instrument and which can enhance the operability of a mounting operation by improving the shape of a prism. SOLUTION: A light introduction part 6b at a prism 6 which is attached to the rear of a dial 4 is constituted of a first bent part 601 which is adjacent to a light source 8 and of a second bent part 602 which is bent to the direction of a body part 6a at the prism 6 from the first bent part 601. A first reflection part 603 is formed between the first bent part 601 and the second bent part 602, and a second reflection part 604 is formed between the second bent part 602 and the body part 6a. Light from the light source 8 is introduced to the first bent part 601, and the light is reflected by a pointer 11 from the reflecting end face 14 of an opening part 13 in the prism 6 so as to be illuminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an instrument illuminating device for illuminating a pointer such as an instrument for an automobile, and more particularly to an illuminating device for a meter having a prism for guiding light from a light source to a pointer.

[0002]

2. Description of the Related Art FIG. 2 shows an example of a conventional instrument lighting device.

A wiring board 2 is mounted on a bottom plate of an instrument case 1, and an inner unit 3 is mounted on the wiring board 2. Prism 6 made of transparent resin on the back of dial 4
Is attached. This prism 6 has a main body 6a
A light introducing portion 6b having a tapered shape is formed at an end of the light introducing portion 6, and a light source 8 such as a bulb is disposed at an end of the light introducing portion 6b.
The pointer 1 arranged on the dial 4 is attached to the pointer shaft 10 of the inner machine 3.
One cap portion 12 is fitted. A tapered reflection end surface 14 is formed on the end surface of the opening 13 of the prism 6 through which the pointer shaft 10 passes.

The light from the light source 8 received by the light introducing portion 6b is reflected upward by the reflecting end face 14 and illuminates the pointer 11 via the cap portion 12.

[0005]

The light emitted from the light source 8 is:
Most of the light is received by the light introducing portion 6a of the prism 6, but light not received by the light introducing portion 6a becomes the direct light 15 and leaks from the opening 13 of the prism 6, and the direct light 15 This causes a problem that the dial 4 becomes difficult to see, and the quality of the instrument is deteriorated. When the inner unit 3 needs to be attached far away from the prism 6 as shown in FIG. 2 due to the layout of the instrument, the above phenomenon is remarkable.

In order to prevent this, there is conventionally known a structure in which a shielding plate 16 standing upright from the case 1 is provided between the inner unit 3 and the light source 8 and the shielding plate 16 blocks the direct light 15. Have been. However, with this structure, if the space in the instrument is small, the shield plate 16 may not be provided due to the problem of interference between the shield plate 16 and the internal machine 3 (or / and the prism 6). Light 15
There is a problem that can not be eliminated.

Further, if the position of the light source 8 is shifted even a little, the direct light 15 is emitted, so that there is a problem that the degree of freedom of the installation place of the light source 8 is small and the mounting work is difficult.

The present invention has been made in view of the above points. By improving the shape of the prism, light leakage to the front face of the dial is eliminated to improve the quality of the instrument.
It is an object of the present invention to provide a lighting device for an instrument which can improve the mounting workability.

[0009]

According to a first aspect of the present invention, light from a light source is introduced into a light introducing portion of a prism attached to the back surface of a dial to form the prism. A lighting device for reflecting and illuminating light from a reflection end face of the opening to a pointer, wherein the light introducing portion includes a first bent portion adjacent to the light source, and the first bent portion extending from the first bent portion. A second bent portion bent in the direction of the main body of the prism, and a second bent portion between the first bent portion and the second bent portion and between the second bent portion and the main body portion. It is characterized in that a first reflector and a second reflector are provided.

Therefore, according to the first aspect of the invention, the light of the light source first enters the first bent portion of the adjacent light introducing portion, is guided to the pointer through the second bent portion, and opens the prism opening. No light leakage from the part.

According to a second aspect of the present invention, in the instrument lighting device of the first aspect, the first bent portion is located on a straight line connecting the light source and the opening. It is characterized by the following.

Therefore, in the invention according to the second aspect, all the direct light directed toward the opening of the prism is introduced into the first bent portion, and light leakage from the opening can be eliminated.

[0013]

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. 2 are denoted by the same reference numerals.

In FIG. 1, a wiring board 2 is mounted on a bottom plate of a case 1 of an instrument.
Is attached. The dial 4 is mounted on the instrument 1 at the opening side, and a prism 6 made of a transparent acrylic resin or the like is mounted on the back of the dial 4. Reference numeral 5 in FIG.

The prism 6 has a two-stage light introducing portion 6b composed of a first bent portion 601 and a second bent portion 602 at an end of a main body 6a in contact with the back surface of the dial 4. Is formed. The second bent portion 602 is formed so as to be substantially perpendicular to the main body portion 6a attached to the back surface of the dial 4, and the first bent portion 601 is formed by the second bent portion 602.
From the outside to be bent in a tapered shape. Main unit 6
a and a second tapered outer surface between the second bent portion 602 and the second bent portion 602.
A reflection portion 604 is formed, and a tapered first reflection portion 603 is formed on an inner surface between the second bent portion 602 and the first bent portion 601.
Are formed. The light source 8 is arranged adjacent to an end of the first bent portion 601.

A cap portion 12 of a pointer 11 arranged on the dial 4 is fitted into a pointer shaft 10 of the inner unit 3.
A tapered reflection end surface 14 is formed on the end surface of the opening 13 of the prism 6 through which the pointer shaft 10 passes.

The light of the light source 8 received by the first bent portion 601 of the light introducing portion 6b is reflected by the first reflecting portion 603, passes through the second bent portion 602, and is reflected by the second reflecting portion 604. The pointer 11 is illuminated via the cap 12 after being reflected upward by the reflection end face 14. Therefore, all the light traveling in the direction of the direct light 15 in FIG. 2 is reflected by the first reflector 603 and is used for illumination of the pointer, so that light leakage from the opening 13 can be eliminated.

In the above embodiment, the first bent portion 60
1 is preferably an angle directed to a direction of a straight line connecting the light source 8 and the opening 13 of the prism 6 (corresponding to the direction of the direct light 15 in FIG. 2). With this configuration, of the light emitted from the light source 8, all the light corresponding to the direct light 15 in FIG. 2 is introduced into the light introducing portion 6 b, and does not leak in the direction of the opening 13.

The angle and length of the second bent portion 602 can be arbitrarily set according to the layout in the instrument.

As described above, in the instrument lighting device of the present embodiment, the light introducing portion 6b of the prism 6 is replaced with the first bent portion 60.
With the two-stage shape of the first and second bent portions 602, all direct light from the light source 8 toward the opening 13 of the prism 6 can be introduced from the light introducing portion 6b into the prism 6, and the layout of the instrument can be improved. Light leakage from the opening 13 can be completely prevented without replacement or addition of the conventional shielding plate 16 or the like, and deterioration of the quality of the instrument due to light leakage can be prevented. In addition, even if the mounting position of the light source 8 is slightly shifted, the light is
Therefore, the degree of freedom in mounting the light source 8 is increased, and the mounting operation is simplified.

[0021]

As described above in detail, according to the first aspect of the present invention, the light introducing portion has a two-stage structure of the first bent portion and the second bent portion, so that the light of the light source can be reduced. Enters the first bent portion of the light introducing portion, is guided to the pointer through the second bent portion, does not leak to the opening of the prism, changes the layout of the instrument, and adds a shielding plate or the like. The light leakage can be prevented without any problem, and the quality of the instrument can be improved. Further, even if the mounting position of the light source is slightly shifted, the light is introduced into the first bent portion, so that the degree of freedom of mounting the light source is increased and the mounting operation is simplified.

According to the second aspect of the present invention, the first
Since the bent portion is located on a straight line connecting the light source and the opening, all the direct light directed toward the opening of the prism is introduced into the first bent portion, and as a result, the light leakage from the opening is reliably prevented. Can be prevented.

[Brief description of the drawings]

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

FIG. 2 is a vertical side view of a conventional instrument lighting device.

[Explanation of symbols]

 Reference Signs List 3 Internal machine 4 Dial 6 Prism 6a Main body 6b Light introducing part 601 First bent part 602 Second bent part 603 First reflecting part 604 Second reflecting part 8 Light source 10 Pointer shaft 11 Pointer 13 Opening 14 Reflecting end face

Claims (2)

[Claims] 1. An instrument for introducing light from a light source into a light introducing portion of a prism attached to the back surface of a dial and reflecting light from a reflecting end face of an opening formed in the prism to a pointer to illuminate the instrument. An illumination device, wherein the light introducing portion includes a first bent portion adjacent to the light source, and a second bent portion bent from the first bent portion toward the main body of the prism. And a first reflecting portion and a second reflecting portion are provided between the first bent portion and the second bent portion and between the second bent portion and the main body portion, respectively. Instrument lighting equipment. 2. The instrument lighting device according to claim 1, wherein the first bent portion is located on a straight line connecting the light source and the opening.