JPS5919317B2 - electronic clock - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic timepiece having an electro-optical display element as a display device, and more particularly to an electronic timepiece having only one circuit board on which an electronic circuit is mounted.

Recent advances in electronic technology have greatly simplified the construction of digital display watches, such as liquid crystal display digital watches.

Thanks to improvements in liquid crystal materials and display device structures, battery voltage has been reduced to approximately 1.
With the development of a liquid crystal display device that can be driven at 5V, a step-up circuit is no longer necessary, and by sealing the crystal resonator in a ceramic container and combining it with an oscillation circuit to adjust the frequency, the trimmer capacitor can also function as an amplifier. It has come to be manufactured in a semiconductor integrated circuit (engineering C) having an inverter. As a result, the simplest configuration of a liquid crystal display type electronic wristwatch excluding the case is one that includes a liquid crystal display device, a semiconductor IC, a crystal resonator, a circuit board, structural members, and leads. Backed by such technological advances, there is a trend towards making electronic watches thinner, lower in cost, and more reliable, but technological progress alone is not the only way to achieve these goals; It is not uncommon for innovations in the structure of the system to have extremely large effects. As seen in the cross-sectional view shown in FIG. 1, in the conventional digital electronic watch, a semiconductor IC 2 is mounted on the upper surface 11a of a first circuit board 11, and a battery 3 as a power source is mounted on the lower surface Ilb of the first circuit board 11. One electrode is in contact with the potential of the through hole I.
It is connected to the upper surface Ila by lc.

In addition, the circuit elements 6a that cannot be mounted on the upper surface Ila are placed on the lower surface 1a.
1b, and another circuit element 6b is attached to the second circuit board 12. Mechanical and electrical connections between the first and second circuit boards are made by pins Ba and screws 8b. The other electrode of the battery is transmitted to the upper surface 11a of the first circuit board via the battery lead plate T and the pins (Ba) and screws 8b that attach it. Electrical connection between the output terminal from the semiconductor device C2 and the display device 4, which is arranged on the upper surface Ila of the first circuit board, is made by a connector 5. FIG. 2 shows a cross-sectional view of a relatively simplified conventional example. What is mounted on the circuit board 1 is a semiconductor IC 2 on the top surface 1a, and a lead plate that receives one electrode of the battery 3. Tb, circuit element 6 on the bottom surface Ib
is attached by extending a terminal to the upper surface 1a and soldering, and a battery lead plate T in contact with the other electrode of the battery is screwed, and the potential from this is transmitted to the upper surface 1a by a through-hole IC.

Of the two examples I have explained so far, in the first case, even though the circuit board used has single-sided wiring, it has two layers stacked on top of each other, which requires the production cost of two boards, and also connects the two boards. The screw pins used also affect the cost.

In addition, in the latter example, even if only one board is used, it is a double-sided board that requires through holes, which not only increases the cost of manufacturing the board, but also reduces the reliability of the circuit. The presence of holes can cause deterioration, and it is clear that a circuit using a double-sided wiring board is not preferable for basic performance testing. In order to eliminate these drawbacks of circuit boards for electronic watches, the present invention fixes and stores electrical connection lead members such as battery lead plates in a resin frame placed on the surface of the circuit board.
The object of the present invention is to enable an electronic timepiece having only one single-sided wiring board as a circuit board, and to provide a low-cost, highly reliable thin electronic timepiece.

The details of the present invention will be explained below with reference to the drawings.

FIG. 3 is a plan view of a digital wristwatch showing one embodiment of the present invention, and FIG. 4 is a sectional view thereof. A semiconductor 1C2 is provided on the upper surface 1a of the circuit board 1, a power supply battery 3 is fitted into an open hole in the circuit board, and a display device 4 is connected to a connector 5.
It is electrically connected to the pattern on the upper surface 1a of the circuit board by the upper resin frame 10a, and positioned by the upper resin frame 10a.
On the lower surface (circuit board side) of the upper resin frame 10a, there are convex parts 101 to 103 molded at the same time, which connect other circuit elements 6 fixed to the lower resin frame 10b and the pattern on the upper surface 1a of the circuit board. A lead plate 7c for electrical connection, and battery lead plates 7a and 7b that are in contact with the two electrodes of the battery 3 and electrically connected to the circuit board, respectively, are attached.
The lead plates 7a to 7c are attached to the upper resin frame using the convex portions 1.
03, the pin may be fixed by thermally deforming it after fitting the lead plate, or it may be fixed by making the diameter of the pin slightly larger than the diameter of the hole of the lead and providing an interference margin.

As shown in FIG. 4, these components are, from top to bottom, a panel 4, an upper resin frame 10a, a circuit board 1, and a lower resin frame 10.
If the connector 5 and the lead plates 7a to 7c are laminated with the connector 5 and the lead plates 7a to 7c, the electrical connection is completed.

The electrical connection will be explained in detail using the battery lead plate 7a as an example. The battery lead plate 7a is connected to the pin 10 of the upper resin frame 10a.
2, by holding the circuit board 1 between the lower resin frame 10b, the first contact point 7a1 contacts the electrode 11a (see FIG. 5) on the circuit board,
The second contact 71 contacts one electrode of the battery. Similarly, the other lead plates 7b and 7c are in contact with the electrodes 11b and 11c on the circuit board, respectively, and at the same time are in contact with the electrodes of the corresponding parts to complete the electrical connection relationship. A plan view of the circuit board used in the electronic timepiece described so far is as shown in FIG.

A group of output terminals to the liquid crystal panel wired from the part where the semiconductor 1C is mounted and its surroundings, and the input 11a from the battery.
, 11b1 The connections 11c and 11d with the crystal oscillator are wires, and the shape is a single-sided wiring board having a battery hole, a lead bending hole, etc. This kind of electronic clock uses only one single-sided wiring board to create an electric circuit.Firstly, it can be produced at low cost.Secondly, it has high reliability as there are no through holes etc., and thirdly, it has high reliability. It has the advantage of being convenient to handle, such as inspecting circuit characteristics, and provides excellent effects as a structure for electronic watches. Note that the circuit board can be held between the upper resin frame and the lower resin frame by heat caulking using simultaneous molding pins, by caulking using metal pins, or by using pins and screws. A fixing method using a molded flexible exchange part may also be used. Further, the present invention can be easily inferred to a watch in which the lower resin body in the description is constructed as a part of a watch case.

[Brief explanation of drawings]

Figures 1 and 2 show a conventional electronic watch, Figure 3 is a plan view of the electronic watch according to the present invention, Figure 4 is a cross-sectional view of the same, and Figure 5 shows the electronic watch of the present invention. This is an example of a circuit board used. 1... Circuit board, 2... Semiconductor 1C,
3...Battery, 4...Display device, 5...
...Connector, 6...Circuit element, 7...
...Lead plate, 8...Screw, pin, 10...
...Resin frame.

Claims (1)

[Claims] 1. A time display panel for displaying the time, an upper resin frame that holds the time display panel, and a semiconductor IC placed below the resin frame that generates a time signal.
and a circuit board in which a circuit configuration including the semiconductor IC is provided only on the side facing the upper resin frame, a lead member disposed between the upper resin frame and the circuit board, and the time display. An electronic timepiece comprising a connector provided between the panel and the circuit board, and a battery serving as a power source for the circuit configuration.