JPH0132258Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electronic watch that prevents static electricity from flowing into an IC from multiple operation buttons arranged on the exterior of the watch via a switch spring and a pattern on a circuit board.

A conventional electronic wristwatch is shown in FIG. 1 is a circuit board on which IC etc. are mounted, 2 is a battery, 3 is a switch spring, 4 is an operation button arranged on the exterior, 5 is an exterior case, and 6 is a waterproof packing. An IC in which a positive power source is formed on the circuit board 1 by conduction springs 3a and 3b integrally formed on the switch spring 3.
is supplied to the conductive pattern 1a. Similarly, when the operating button 4 is pressed, the conductive spring 3c, which is also integrally formed on the switch spring 3, comes into contact with the switching pattern 1b formed on the circuit board 1 with a certain load, and thereby It functions as a switching function. In this structure, electrical continuity between the operating button 4 and the outer shell 5 is extremely unstable due to the waterproof gasket 6. (It is sometimes in a conductive state, but not in a conductive state.) Therefore, when it is in a non-conductive state, static electricity enters the inside of the watch through the operation button 4, and the conductive pattern to the switch springs 3c, 3b and the IC. It flows into the IC through 1a and causes IC malfunction and IC destruction. Of course, if the operation button 4 and the outer case 5 are electrically connected, there is no problem because the static electricity escapes to the human body through the outer case 5 and the back cover 7. However, in many cases, they are in a non-conductive state, which often causes the above-mentioned problem. The following solutions are possible for this problem. FIG. 2 is a plan view of the switch spring, and 3a, 3b, and 3c are as described above. 3d is a conduction spring for grounding to the back cover 7, and as explained above, the switch spring 3
The purpose is to release the static electricity that has flowed into the back cover through 3d. However, although this method is certainly effective against the static electricity that flows from the operation button on the left side of the front panel in FIG. 2, the static electricity that flows from the operation button on the right side quickly enters the IC through 3b.
For this reason, the method shown in FIG. 2 cannot completely prevent static electricity from entering from a plurality of operation buttons.

Therefore, countermeasures such as arranging a large number of conductive springs 3d to the back cover or arranging 3d very close to 3b can be considered, but these are often not possible due to design space and the above problem cannot be avoided. It was.

The present invention eliminates such drawbacks, and its purpose is to control the operation from multiple operation buttons arranged on the exterior via a switch spring and a pattern on the circuit board.
This provides a method for dissipating static electricity flowing into an IC through exterior parts to the human body before it flows into the IC.

The present invention will be described in detail below based on examples. FIG. 3 is a plan view of a circuit board showing an embodiment of the present invention. 1a is the contact pattern with the switch spring as in FIG. 1c is an IC, which has a section 1d between 1c and 1a. Fourth
The figure is a sectional view of an electronic wristwatch showing an embodiment of the present invention. All symbols are the same as in Figure 1. Here, the conduction spring 3b has a portion 3e extending from the switch spring 3 toward the back cover, a bent portion 3f that contacts the back cover, and a portion 3f extending from the bent portion and formed on the surface of the circuit board 1 on the back cover side. A tip portion 3g that contacts the conductive pattern 1a is provided. In other words, conduction spring 3
b is in contact with the conductive pattern 1a and the back cover 7 at the same time. According to this method, the IC can be protected from static electricity because the static electricity that has entered the switch spring from the operation button can be released to the back cover 7 before it flows into the pattern on the circuit board 1.

The conduction spring 3 is only changed in shape compared to the conventional example, and the number of parts is not increased by adding new parts, so the cost does not increase significantly.

Furthermore, since the conduction spring 3 has elasticity as is generally known, when the circuit board 1 and the switch spring 3 are assembled into the outer body 1 and the back lid 7, the bent portion 3f and the tip end 3g will be elastically pressed against the circuit board and the back cover. Therefore, the contact between the conduction spring 3b and the back cover and the conduction pattern becomes better, and it is also possible to prevent conduction failure at the contact portion due to external impact or the like. In other words, according to the present invention, static electricity can be removed from the IC.
This will result in new effects being achieved by implementing measures to protect the public at a slight cost increase. It should be added here that even if the above method is adopted, it will not be possible to completely protect the IC no matter how high the level of static electricity flows into it. This provides a method that can raise the level of static electricity resistance of an IC, even if it is quite low, to a level that does not interfere with daily life.

As described above, the present invention allows static electricity that attempts to flow into the IC from multiple operation buttons arranged on the exterior via the switch spring and the pattern on the circuit board to escape to the human body through the exterior parts before flowing into the IC. This method has an excellent effect in that it allows the method to be implemented without significantly hindering the design space, cost, etc.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional electronic wristwatch. Figure 2 is a plan view of a conventional switch spring. FIG. 3 is a pattern diagram of a circuit board according to the present invention. FIG. 4 is a sectional view of the electronic wristwatch according to the present invention. 1 is a circuit board, 2 is a battery, 3 is a switch spring,
4 is the operation button, 5 is the outer body, 6 is the waterproof gasket,
7 is the back button.

Claims (1)

[Scope of utility model registration request] An outer body 5, a back cover 7, a plurality of operation buttons 4 arranged on the outer body, a circuit board 1 on which an IC is mounted and a conductive pattern 1a for electrically conducting to the IC is formed, and the circuit board. A battery 2 disposed between the back lids and a first conduction spring 3 in contact with the battery.
a and a switch spring 3 integrally provided with a second conductive spring 3c that contacts each of the operating switches, the switch spring is a first conductive spring that supplies power from the battery to the conductive pattern 1a. The third conductive spring includes a portion 3e extending from the switch spring toward the back lid, and a bent portion 3 that contacts the back lid.
f, and a tip portion 3g extending from the bent portion and contacting the conductive pattern formed on the surface of the back lid side of the circuit board, and the circuit board and the switch spring are connected to the outer body and the end portion 3g. When the electronic timepiece is assembled into the back cover, the bent portion and the tip end are elastically pressed against the circuit board and the back cover, respectively.