JPH0635994U - Anti-static shield structure of electronic wrist watch - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention is to provide a structure of a movement, which is improved in static resistance, to a conventional electronic wrist watch. [Structure] The battery pressing plate 3 and the back plate 4 are electrically connected to each other, and the movement composed of the plastic base plate 2 is electrostatically shielded from both upper and lower surfaces. [Effect] The static electricity resistance is improved and the reliability is further enhanced by static electricity shielding the movement with the battery pressing plate 3 and the back plate 4 having the same electrode property.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electrostatic shield structure for an electronic wrist watch.

[0002]

[Prior art]

 In recent wristwatches, the movement consisting of a plastic base plate and a bridge is housed in a plastic exterior, so that it is becoming more and more versatile to meet lower prices and diversify designs. By the way, in a movement composed of a plastic base plate and a bridge, the IC mounted on the circuit block is surrounded by plastic parts. Therefore, these plastic parts are easily charged with static electricity. Furthermore, in the case where a plastic exterior is used, not only the ground plane and the receiver but also the exterior are charged.

[0003]

[Problems to be solved by the device]

 However, there is a drawback that the IC malfunctions while being carried by the influence of static electricity charged on the plastic parts and the exterior of the plastic. This malfunction is fatal in, for example, a chronograph or a multifunctional watch with an alarm using a microcomputer IC.

An object of the present invention is to solve the above problems, and to provide a structure for improving the resistance to static electricity, as compared with a conventional electronic wrist watch.

[0005]

[Means for Solving the Problems]

 The gist of the present invention for achieving the above object is an electronic device including a plastic base plate, an IC mounted on a circuit block arranged in the upper surface direction of the base plate, and a battery serving as a power source of the IC. In a movement of a wristwatch, a metal back plate arranged in a lower surface direction of the main plate and a connecting means for electrically connecting the back plate and the battery are provided.

[0006]

[Action]

 In the antistatic structure of the present invention, since the back plate which is electrically connected to the battery is provided in the dial direction, the static electricity charged on the plastic exterior is less likely to affect the IC, and the main plate is charged. It also has a structure that improves static resistance.

[0007]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing one embodiment of the present invention. The circuit block 1 is composed of a print substrate 1b on which an IC 1a driven by a battery 5 is mounted. Reference numeral 2 is a base plate, which is made of plastic. Reference numeral 3 denotes a battery pressing plate made of metal that serves to fix the circuit block 1 to the main plate 2 and also serves as an electrostatic shield in the direction of the back cover 9 of the circuit block 1. It has a pressing portion 3a for taking. Reference numeral 4 is a metal back plate which serves as an electrostatic shield in the direction of the dial 7 of the main plate 2. The back plate 4 is provided with a spring portion 4a which is brought into pressure contact with a battery pressing plate 3 and a pillar 2a to which a screw for fixing the battery pressing plate 3 to the base plate 2 is attached for electrical connection. The dial 7 is placed on the back plate 4. The movement is surrounded by a plastic outer casing 8, case back 9 and windshield 10. 6 is a screw for fixing the back cover 9, and 11 is a crown. The spring portion 4a does not have to be integrated with the back plate 4, and there is another spring component or a method of connecting the back plate 4 and the battery pressing plate 3 with a screw.

Since the IC 1 a has a structure in which it is in the shadow of the back plate 4 and further sandwiched between the battery pressing plates 3, it is less susceptible to the static electricity charged on the windshield 10 and the back cover 9. .

[0009]

[Effect of device]

 As is clear from the above description, according to the present invention, the movement composed of the plastic base plate is electrostatically shielded by the metal parts having the same electrode property from both sides of the upper and lower surfaces, whereby the static electricity resistance is improved and the reliability is improved. It is possible to provide an electronic wrist watch with improved performance.

[Brief description of drawings]

FIG. 1 is a sectional view of an electronic wrist watch showing an embodiment of the present invention.

[Explanation of symbols]

 1 Circuit Block 1a IC 1b Printed Circuit Board 2 Base Plate 3 Battery Press Plate 3a Press Section 4 Back Plate 4a Spring Part 5 Battery 6 Screw 7 Dial 8 Body 9 Back Cover 10 Windshield 11 Crown

Claims (1)

[Scope of utility model registration request] 1. A movement of an electronic wrist watch comprising a plastic base plate, an IC mounted on a circuit block arranged in an upper surface direction of the base plate, and a battery serving as a power source of the IC. A static electricity resistant shield structure comprising: a metal back plate arranged in a lower surface direction of the base plate; and a connecting means for electrically connecting the back plate and the battery.