JPS6042389Y2 - Light guide plate used in watches, etc. - Google Patents

Description

[Detailed Description of the Invention] The present invention mainly relates to a light guide plate for efficiently illuminating the hands of a watch or the like.

Conventionally, as shown in FIG. 6, when attaching the light guide plate 1 to the movement, the hole 2 for mounting the light guide plate 1 to the movement is circular, so that the transmitted light is reflected and diffused by the circular portion 3, making it difficult to condense the light to the zero point. This has the disadvantage of being difficult and having poor light collection efficiency.

On the other hand, due to the design, it may be difficult to change the position of the mounting hole 2 from the position shown in FIG. 6.

The present invention has been devised in view of these points, and its contents will be explained below based on the illustrated embodiments.

Reference numeral 10 denotes a light guide plate body made of transparent synthetic resin, which has a through hole 11 in the center, so that the light emitted from the light source 12 is ultimately focused on a point P.

13 is a first reflective surface provided on the light guide plate main body 10, 14 is a second reflective surface, and 15 is a third reflective surface.

Normally, the light emitted from the light source 12 passes from the portion 16 of the light guide plate main body 10 through the incident waist-reflection surface 13, the second reflection surface 14, and the third reflection surface 15, and is focused on a point P. It is designed.

Numeral 17 is a counterbore hole provided in the light guide plate main body 10 for mounting the light guide plate, and for mounting, a screw hole 19 for the screw 18 is bored, and a specific inner wall surface 20 of the counterbore hole 17 is formed into a reflective curved surface 2 of an appropriately shaped shape.
1, the reflected light Q emitted from the light source 12 and reaching the respective reflecting surfaces 13 and 14 is further reflected by the string and focused at point P, which is the position of the pointer axis.

By forming the reflective curved surface 21 on the inner wall surface 20 of this counterbore hole 17, light collection efficiency can be improved.

Next, the operating mode of the device of the present invention having the above configuration will be explained.

A part of the light R emitted from the light source 12 enters from the portion 16, passes through the first reflective surface 13, the second reflective surface 14, and the third reflective surface 15, and reaches the point P of the through hole 11.

On the other hand, another part of the light Q emitted from the light source 12 enters from the portion 16, passes through the first reflecting surface 13 and the second reflecting surface 14, and reaches the reflecting curved surface formed on the inner wall surface 20 of the counterbore hole 17. 21 and condensed at point P of the through hole 11.

Therefore, the present invention has the structure and function as described above, and in particular, since a reflective curved surface is formed on the inner wall surface of the counterbore hole used for mounting the light guide plate, the reflected light is condensed and the lighting efficiency is improved. This has the great effect of significantly improving the

It goes without saying that it can be applied not only to clock lighting but also to other instruments.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the product of the present invention, Fig. 2 is a developed view, Fig. 3 is a cross-sectional view of the A-A section in Fig. 2, and Fig. 4 is a counterbore hole feature of the present invention. Enlarged perspective view, Figure 5 is B of Figure 4
6 is a developed view of a conventional light guide plate. 10...Light guide plate body, 17...Counterbore, 0...Inner wall surface, 21...Reflection curved surface.

Claims (1)

[Scope of utility model registration request] A light guide plate main body 10 made of transparent synthetic resin is provided with a counterbore hole 17 for mounting the light guide plate, and a reflective curved surface 21 is formed on the inner wall surface 20 of the counterbore hole 17. A light guide plate used in a watch or the like, which is designed to reflect light by the reflective curved surface 21 and focus it on a point P.