JPS6231908Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the support structure of a small lamp for illuminating a liquid crystal cell in a digital display type electronic watch.

In recent years, with the spread of digital display electronic watches (hereinafter simply referred to as electronic watches), electronic watches have been equipped with a small lamp inside and can be made smaller by operating an external switch so that the time can be read at night or in dark places. A method is often used in which a lamp is turned on to illuminate the liquid crystal cell.

Fig. 1 is a cross-sectional view of the essential parts of a conventional small lamp support structure for an electronic watch with a built-in small lamp. 1 is a liquid crystal cell having upper and lower polarizing plates 1a and 1b, 2 is a light guide reflector formed by integrating a light guide plate and a reflector for guiding the illumination light from the small lamp, and the liquid crystal cell 1 and the light guide reflector 2 are assembled in this order into a cell support member 3. 4 is a flexible printed circuit board on which circuit elements for driving the liquid crystal cell 1 are mounted, and a small lamp 5 is also mounted on one end of the printed circuit board 4. The printed circuit board 4 is supported and fixed on a circuit support base 6, and then sandwiched between the cell support member 3 and the circuit support base 6. Then, it is hooked and fixed by an elastic portion 7a of a base support plate 7 and a hook portion 3a provided on a part of the cell support member 3. 8 is a battery for driving the electronic watch. The small lamp 5 is raised to a lateral position of the light guide reflector 2 in order to efficiently guide the illumination light.

FIG. 2 is an enlarged view of the main part of the printed circuit board 4 shown in FIG. 1, in which the small lamp 5 is mounted, where a is a view seen from the bottom side and b is a sectional view thereof. As shown in FIG. 2a, one end of the printed circuit board 4 is provided with a hole 4a and a groove 4b for positioning when the small lamp 5 is mounted. FIG. 2b shows the side shape of the small lamp 5, and shows the external terminal 5 of the small lamp 5.
As for a and 5b, in order to enhance the illumination effect as described above, bending is performed by an amount corresponding to the height up to the light guide reflection plate 2.

A plurality of circuit elements (not shown) are mounted on the upper surface of the pattern of the printed circuit board 4, but only the small lamp 5 is mounted on the lower surface of the pattern for ease of mounting. When mounting the small lamp 5 in the mounting process of 4,
The printed circuit board 4 is turned over and turned over. The small lamp 5 provided on a part of the printed circuit board 4
After accommodating and positioning the external terminals 5a and 5b of the small lamp 5 in the hole 4a and groove 4b for positioning the small lamp 5, the small lamp 5 is mounted on the printed circuit board 4 by welding, and mechanically and electrically The connection is fixed. In this example, a fixing method by welding has been described, but the same applies to a fixing method by soldering or the like.

As described above, in the conventional technology, in order to enhance the lighting effect of the small lamp 5, it is necessary to bend the external terminals 5a and 5b of the small lamp 5, and furthermore, in the mounting process of the printed circuit board 4, a plurality of circuit elements are While all of the lamps are mounted on the top side, only the small lamp 5 is mounted on the bottom side for ease of positioning during mounting, so the printed circuit board 4 must be reversed and turned over, which reduces the number of steps in the automated process. This causes an increase in costs, such as an increase in the amount of paper and the need for a separate transport jig. Furthermore, since the external terminals 5a and 5b of the small lamp 5 are made of thin wires, they are easily deformed, are difficult to handle, and are extremely easy to deform, so the bending height is not uniform, resulting in defective shapes. However, there are many factors that increase costs, such as lower yields.

The purpose of this invention is to provide a support structure for small lamps that does not reduce lighting efficiency even when mounted on a circuit board without bending the lead wires of small lamps, simplifies the process of mounting small lamps, and is suitable for automation. Our objective is to provide an electronic watch with the following features.

Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 3 is an enlarged view of a small lamp mounting section provided at one end of the printed circuit board of the present invention,
FIG. 3a is a top view, and FIG. 3b is a sectional view. In FIG. 3, 10 is a flexible printed circuit board, 11 is a small lamp used in this example,
10a is a hole for positioning when the small lamp 11 is mounted, and 10b is a hole for inserting electrodes when the external terminals 11a, 11b of the small lamp 11 are welded to the pattern of the printed circuit board 10. After storing and positioning the small lamp 11 in the positioning hole 10a provided at one end of the printed circuit board 10, the small lamp 11 is connected to the external terminals 11a, 11.
b is welded to the upper surface side of the wiring pattern on the printed circuit board 10, and is mechanically and electrically connected and fixed.

The small lamp 11 of this embodiment is mounted on the upper surface side of the wiring pattern on the printed circuit board 10 like a plurality of circuit elements (not shown) for driving the liquid crystal cell, and the external terminal of the small lamp 11 is mounted on the upper surface side of the wiring pattern on the printed circuit board 10. 11
A and 11b do not require bending.

FIG. 4 is a sectional view of essential parts of a digital display type electronic timepiece incorporating the printed circuit board described in FIG. 3, and the same numbers as in FIG. 1 indicate the same members. 12 is a cell support member, and 13 is a circuit support stand, both of which are provided with holding portions 12a and 13a for holding the ends of the printed circuit board 10, respectively. First, the liquid crystal cell 1 and the light guide reflection plate 2 are assembled into the cell support member 12. The printed circuit board 10 is
By being supported and fixed on the circuit support stand 13, the end portion of the printed circuit board 10 is bent upward by the holding portion 13a of the circuit support stand 13. after that,
When the cell support member 12 and the circuit support stand 13 are brought together, the ends of the printed circuit board 10 are held between the holding parts 12a and 13a provided on the cell support member 12 and the circuit support stand 13. In the case of this example, the small lamp 11 mounted on the end of the printed circuit board 10 is at a height that is located on the side of the light guide reflection plate 2 due to the convex portion 13b provided on the circuit support stand 13. It is constructed so that it can be easily held. That is, the vicinity of the printed circuit board 10 where the small lamp 11 is mounted is forcibly bent upward by the convex portion 13b. Thereafter, it is hung and fixed by the elastic part 7a of the base plate support plate 7 and the hook part 12b provided on a part of the cell support member 12. 8 is a battery for driving the electronic clock.

As mentioned above, according to the present invention, the small lamp is mounted on the same side of the printed circuit board as the multiple circuit elements for driving the liquid crystal cell, so there is no need to flip the printed circuit board in the mounting process, and All implementation is completed. In addition, the printed circuit board with the lamp attached is bent and held by the holding part and convex part of the circuit support stand, and the small lamp is lifted to the side of the light guide plate, so there is no need to bend the external terminals, and furthermore, The mounting process is simple, such as using a different type of transport jig, and a digital display electronic timepiece can be provided at low cost without reducing the illumination efficiency of the small lamp.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the main parts of a conventional small lamp support structure, FIG. 2 is a sectional view of the mounting part of the small lamp shown in FIG. Figure 2b is a sectional view, and Figure 3 shows the mounting structure of the small lamp of the present invention.
FIG. 3A is a top view, FIG. 3B is a cross-sectional view, and FIG. 4 is a cross-sectional view of essential parts showing the support structure of the small lamp of the present invention. 1...Liquid crystal cell, 2...Light guide reflection plate, 3, 12
... Cell support member, 4, 10 ... Printed circuit board,
5, 11...Small lamp, 6,13...Circuit support stand, 7...Main plate support plate, 8...Battery, 12a, 1
3a...holding part, 13b...convex part.

Claims (1)

[Scope of utility model registration request] a liquid crystal cell, a cell support member positioned to surround the liquid crystal cell from the upper surface and the outer periphery, a light guide plate disposed along the lower surface of the liquid crystal cell, and a light guide plate disposed substantially along the lower surface of the light guide plate, A flexible printed circuit board on which a circuit element for driving the liquid crystal cell and a small lamp for illuminating the liquid crystal cell are mounted, and the printed circuit board is coupled to the cell support member by a coupling portion while being pressed toward the liquid crystal cell side. In the digital display electronic watch, the printed circuit board has a positioning hole at one end thereof for positioning and sinking the small lamp along the side surface of the light guide plate, and a positioning hole in the positioning hole. The small lamp is connected and fixed to the wiring pattern of the printed circuit board without bending its lead wire, and the cell support member and the circuit support stand each face a portion of the printed circuit board near the positioning hole. A holding part is provided to hold the light guide plate, and the height of the holding part is set to such a height that the small lamp is lifted to a side position of the light guide plate by partial deformation of the printed circuit board. A digital display type electronic clock.