| 摘要 |
PURPOSE:To enable reduction of the size and the thickness of an instrument, by a method wherein a light source is placed on the dial plate of the instrument, and the light source is formed with a guiding body, guiding light to a needle point and the central part of the dial plate, and reflector. CONSTITUTION:A bulb 9 is attached to a socket 8 on a dial plate 7 and about in the same level as that of a cylindrical inner hole part 10 of a guiding body 2. The inner surface of an upper case 3 above the bulb 9 forms an X-X axis parabolic rotary surface, on which alumi metalization for reflection is applied. The inner peripheral surface of the case 3 is formed in a shape in that right angled conical surfaces are vertically superposed with each other to apple metalization thereon. Thus, light from the bulb 9 is advanced within a guiding body 2 in parallel to a dial plate 7, the light is reflected by the inner peripheral surface 3 to collect it to a portion in the vicinity of a needle point stem 12, and the light is emitted in a space 21. A needle point 4 and graduations on the dial plate 7 are illuminated with the light, and a driver can see it in the night. This enables elimination of a space under the dial plate 7, and permits provision of a speedometer which is decreased in thickness and size.
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