JPH0996682A - Illuminator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illuminator for illuminating the dial uniformly over the entire surface thereof. SOLUTION: The illuminator comprises light sources 12a, 12b for illuminating a substantially circular dial 8 having with decorations 9, 10 applied on it. An annular optical conductor 13 introduces the light from light source 12a, 12b to the surroundings of dial 8. The optical conductor 13 has inclining reflective faces 15a, 15b (first reflective face) for reflecting the light in the circumferential direction to the vicinity of light source 12a, 12b. The optical conductor 13 is also provided with outer circumferential faces 18a, 18b becoming thinner as going radially apart from the inclining reflective faces 15a, 15b and reflecting the light to the dial 13 side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device,
In particular, the present invention relates to an illuminating device that illuminates a dial using an annular light guide.

[0002]

2. Description of the Related Art Conventionally, various illuminating devices have been proposed for illuminating a dial by guiding light from a light source with an annular light guide, for example, illuminating an automobile instrument disclosed in Japanese Utility Model Laid-Open No. 4-1002525. As shown in FIG. 5, the device guides the light of the light bulb 1 around the dial 3 by the annular light guide 2 to illuminate the dial 3, and the light bulb 1 is a part of the light guide 2. The light of the light bulb 1 is incident on the cutout surface 5 of the light guide body 2 and is diffused inside the light guide body 2 while being transmitted to the entire circumference of the light guide body 2. The plate 3 can be illuminated.

[0003]

However, although such an illuminating device has an advantage that the entire surface of the dial 3 can be illuminated by the light bulb 1, the light of the light bulb 1 is guided while being emitted to the dial 3 side. Since the light propagates inside the light body 2, the light becomes weaker as it moves away from the light bulb 1, and the light bulb 1 on the dial 3
There is a problem in that the place away from the light bulb 1 becomes darker than the place close to, and the dial 3 cannot be uniformly illuminated. The present invention has been made in view of the above problems, and provides an illuminating device capable of uniformly illuminating the entire dial.

[0004]

In order to solve the above problems, the present invention has a light source for illuminating a substantially circular dial having a design, and guides the light of the light source to the periphery of the dial. In a lighting device having an annular light guide, the light guide may reflect the light in a circumferential direction at a position near the light source.
And a second reflecting surface which is provided so as to be gradually thinned in the radial direction as the distance from the first reflecting surface is increased and which reflects the light toward the dial side.

Further, according to the present invention, a reflective layer is provided on the second reflective surface.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Light from a light source is reflected in the circumferential direction of a light guide by a first reflecting surface, propagates inside the light guide, and
It is reflected by the reflecting surface of the dial to the dial side and illuminates the dial. The second reflecting surface is provided so as to be gradually thinned in the radial direction as it is separated from the first reflecting surface, and the cross-sectional area of the light guide body is gradually reduced, so that the density of light propagating in the light guide body is reduced. The dial is kept substantially constant, and the dial can be illuminated substantially uniformly.

Further, by providing a reflecting layer on the second reflecting surface, it is possible to prevent light from leaking from the second reflecting surface, effectively utilize the light from the light source, and illuminate the dial plate brighter. can do.

[0008]

An embodiment of the present invention will be described below with reference to the accompanying drawings. 1 to 3 are views showing a first embodiment in which the present invention is applied to a lighting device for a timepiece.

FIG. 1 is a sectional view of the case 7 of the timepiece 6 cut. 8 is a dial, and this dial 8 has the number 9
(Design) and scale 10 (design) are printed. Reference numeral 11 is a pointer, and when the pointer 11 rotates, the scale 10 of the dial 8 is indicated. Reference numerals 12a and 12b denote light emitting diodes (light sources), and the light emitting diodes 12a and 12b are respectively arranged on the left and right sides of the dial 8 and supply light to a light guide body described later. Reference numeral 13 is a light guide, which is annular and is arranged around the dial 8. Recesses 16a and 16b having inclined reflecting surfaces 15a and 15b (first reflecting surfaces) are formed on the upper surface 14 of the light guide 13 (see FIG. 2). Reference numeral 17 denotes an inner peripheral surface of the light guide body 13, and the inner peripheral surface 17 has a cylindrical side surface shape. Reference numerals 18a and 18b denote outer peripheral surfaces (second reflecting surfaces), and the outer peripheral surfaces 18a and 18b are provided so as to become gradually thinner in the radial direction as the distance from the inclined reflecting surface 12 increases.

The light emitting diode 12a is provided near the lower part of the inclined reflecting surface 15a, and the light emitted from the light emitting diode 12a enters from the incident surface 19 formed below the concave portion 16a.
The inclined reflecting surface 15a reflects the light guide 13 in the clockwise direction in the circumferential direction (see FIG. 3). Similarly, the light emitting diode 12
b is provided near the lower part of the inclined reflection surface 15b, and the light of the light emitting diode 12b is reflected in the circumferential direction of the light guide 13 by the inclined reflection surface 15b. The light reflected by the inclined reflecting surfaces 15a, 15b is diffusely reflected inside the light guide body 13, is reflected by the outer peripheral surfaces 18a, 18b toward the dial 8 side, and is transmitted through the light guide body 25 while being irradiated from the inner peripheral surface 17. To go.

The outer peripheral surfaces 18a and 18b are inclined reflecting surfaces 15a and 15b.
Since the light guide 13 has a cross-sectional area that gradually decreases in a clockwise direction because the light guide 13 is gradually thinned away from the light guide 13, the density of light propagating in the light guide 13 is kept substantially constant. It is possible to illuminate the dial 8 substantially uniformly.

A white reflective layer, for example, may be provided on the outer peripheral surfaces 18a and 18b by printing or coating.
Light is prevented from leaking from a and 18b, and the light emitting diode 12
The lights of a and 12b can be effectively used, and the dial 8 can be illuminated more brightly.

FIG. 4 is a diagram showing a second embodiment in which the present invention is applied to an illuminating device for measuring instruments. 20 is a tachometer and 21 is a dial of the tachometer 20. A number 22 (design) and a scale 23 (design) are printed on the dial 21. 24a, 24
b and 24c are bulbs (light sources), and these three bulbs
24a, 24b and 24c are arranged around the dial 21 at 120 degree intervals. The light guide 23 has inclined reflecting surfaces 26a, 26b, 26c.
Recesses 27a, 27b, and 27c having are formed (see FIG. 5).
reference). Outer peripheral surfaces 28a, 28b, 28c are inclined reflecting surfaces 26a, 26
It is provided so as to gradually become thinner in the clockwise direction as the distance from b and 26c increases.

The light emitted from the bulbs 24a, 24b, 24c is reflected in the circumferential direction by the corresponding inclined reflecting surfaces 26a, 26b, 26c, and travels while being diffusely reflected in the light guide 23,
The outer peripheral surfaces 28a, 28b, 28c are reflected to the dial 21 side,
The light travels through the light guide 25 while being irradiated from the inner peripheral surface 29. The outer peripheral surfaces 28a, 28b, 28c are inclined reflection surfaces 26a, 26b,
Since the light guide 23 is provided so as to be gradually thinned away from 26c, the cross-sectional area of the light guide 23 is gradually reduced in the clockwise direction in the circumferential direction, and the density of light propagating in the light guide 25 is reduced. Since the dial 21 is kept substantially constant, the dial 21 can be illuminated substantially uniformly.

A white reflective layer, for example, may be provided on the outer peripheral surfaces 28a, 28b, 28c by printing or coating to prevent light from leaking from the outer peripheral surfaces 28a, 28b, 28c.
The lights of 24a, 24b, and 24c can be effectively used, and the dial 21 can be illuminated more brightly.

As described above in the first and second embodiments,
The outer peripheral surfaces 18a, 18b, 28a, 28b, 28c of the light guides 13, 25 are provided so as to be gradually thinned away from the inclined reflection surfaces 15a, 15b, 26a, 26b, 26c, and the cross-sectional area of the light guides 13, 25 By gradually reducing the size, the density of light propagating in the light guides 13 and 25 can be kept substantially constant, and the dials 8 and 21 can be illuminated substantially uniformly.

[0017]

The present invention has a light source for illuminating a substantially circular dial having a design, and an illuminating device having an annular light guide for guiding the light of the light source to the periphery of the dial. At
The light guide body is provided in the vicinity of the light source so as to have a first reflection surface for reflecting the light in the circumferential direction, and to be gradually thinned in the radial direction as the distance from the first reflection surface increases. A second reflection surface for reflecting the light toward the plate side, and by providing the second reflection surface of the light guide body so that the second reflection surface is gradually thinned in the radial direction with increasing distance from the first reflection surface, It is possible to keep the density of light transmitted through the dial substantially constant, and illuminate the dial substantially uniformly.

Further, according to the present invention, a reflecting layer is provided on the second reflecting surface, light can be prevented from leaking from the second reflecting surface, and the light from the light source is effectively used. The dial can be illuminated even brighter.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a perspective view showing a light guide according to the embodiment.

FIG. 3 is a sectional view of an essential part showing the embodiment.

FIG. 4 is a sectional view showing a second embodiment of the present invention.

FIG. 5 is a perspective view showing a light guide according to the embodiment.

FIG. 6 is a diagram showing a conventional example.

[Explanation of symbols]

 8 dial 9 number (design) 10 scale (design) 12a, 12b light emitting diode (light source) 13 light guide 15 inclined reflective surface (first reflective surface) 18a, 18b outer peripheral surface (second reflective surface) 21 character Plates 24a, 24b, 24c Bulb (light source) 25 Light guides 26a, 26b, 26c Inclined reflective surface (first reflective surface) 28a, 28b, 28c Outer peripheral surface (second reflective surface)

Claims (2)

[Claims] 1. A lighting device comprising a light source for illuminating a substantially circular dial having a design, and an annular light guide provided for guiding light of the light source to the periphery of the dial. The light body is provided in the vicinity of the light source so as to have a first reflection surface for reflecting the light in the circumferential direction, and to be gradually thinned in the radial direction with increasing distance from the first reflection surface. An illuminating device having a second reflecting surface that reflects the light. 2. The lighting device according to claim 1, wherein a reflective layer is provided on the second reflective surface.