JP3145921U - Eddy current noise cut electronics case - Google Patents

Abstract

An electronic device case that suppresses minute noise given to a music signal, a video signal, and the like due to eddy currents caused by electromagnetic waves generated from components and improves sound quality, image quality, and the like of the electronic device.
An eddy current noise cut electronic device case includes an insulator sandwiched between a metal chassis 12 and a metal cover 10, a metal front panel 17, a metal back panel 16, and a metal bottom plate 11 of the electronic device. The metal cover 10, the metal front panel 17, the metal back panel 16, and the metal bottom plate 11 are electrically separated from each other to a single point ground 7 of the metal chassis 12 with a screwed metal spacer or lead wire. It is possible to improve the performance of the equipment by eliminating the loop through which eddy current flows by connecting.
[Selection] Figure 1

Description

  This invention relates to various fields such as audio equipment such as audio amplifiers and CD players, video recorders such as DVD recorders and televisions, video cameras, music studio equipment, broadcasting equipment, medical equipment, measuring instruments, and communication equipment. It is a device.

  Shield cases and electromagnetic wave shielding plates have been devised and used as methods for protecting electronic devices from the effects of electromagnetic waves, but their effects have not been perfect.

  The purpose of this device is to solve measures against noise caused by eddy currents from electromagnetic waves generated from components inside an electronic device by assembling an electronic device case or a shield case.

  The present invention provides a metal chassis and a metal cover of an electronic device, a metal front panel, a metal back panel, a metal bottom plate, electrically separated by sandwiching an insulator, a metal cover, a metal front panel, It is characterized by reducing the noise of electronic equipment by eliminating loops through which eddy currents flow by connecting each point of metal back panel and metal bottom plate to one point ground of metal chassis with metal spacer with screw or lead wire. is there.

  The present invention has an effect of reducing noise generated from the inside of an electronic device, such as an audio device such as an audio amplifier and a CD player with a clear sound quality, a device for a music studio, a broadcasting facility, a DVD recording and reproducing device with a clear image quality, Video equipment such as televisions and video cameras, high-performance medical equipment, measuring instruments, communication equipment, and the like can be manufactured.

  For example, when considering a two-channel stereo amplifier, the left channel and the right channel can be divided into separate chassis, or in the case of a CD player, the digital circuit and analog circuit can be divided into separate chassis. Also, the preamplifier and the main amplifier are divided into separate chassis, and the whole is subdivided as much as possible, insulated from each other, and assembled, and connected to the ground at one point.

In FIG. 1, 12 is a metal chassis and has 18 screw holes for screw mounting. 10 metal covers, 17 metal front panels, 16 metal back panels, 11 metal bottom plates, and 12 metal chassis, 3 insulator spacers A are sandwiched between each part and fixed between them. For the screw to be used, 1 resin truss screw is used. However, in the case where part of the electrical conductivity is required, 2 metal countersunk screws and 4 metal truss screws are used. The metal cover, metal front panel, metal back panel, and metal bottom plate are connected to the ground point using a metal spacer with 5 screws, and 14 transformers are connected to the ground point with 9 lead wires. To do.
In FIG. 2, when an electronic device is heavy, a metal screw is used because there is a concern that the resin screw may break. In that case, 19 insulator spacers B and 20 convex insulator spacers are sandwiched.
In FIG. 3, when it is impossible to insert a threaded metal spacer inside the electronic device, the lead wire 9 is connected to the ground point.
Fig. 4 shows an example of a transformer shield method usually sealed with a metal case, in which an eddy current loop is eliminated by sandwiching an insulator between a metal cover and a metal bottom plate. To do.

  The present invention is not limited to simply improving the performance of general consumer electronic devices, but can be widely used for industrial electronic devices, for example, when handling weak signals such as in the field of precision measuring instruments and medical devices.

It is sectional drawing and the right view of an electronic device using a metal spacer with a screw. When using a metal truss screw, it is a fragmentary sectional view of the electronic device which uses the insulator spacer B and the convex insulator spacer together. It is sectional drawing and the right view of the electronic device which connected between case components and the earth | ground of the chassis with the lead wire. It is sectional drawing and the right view of the shield case which used the transformer as an example.

Explanation of symbols

1 ... Resin screw 2 ... Metal countersunk screw 3 ... Insulator spacer A
4 ... Metal truss screw 5 ... Metal spacer with screw 6 ... Metal sleeve 7 ... One point ground point 8 ... Brazing connection point 9 ... Lead wire 10 ... Metal cover 11 ... Metal bottom plate 12 ... Metal chassis 13 ... Insulator 14 ... Transformer 15 ... Printed circuit board 16 ... Back panel 17 ... Front panel 18 ... Screw hole 19 ... Insulator spacer B
20 ... Convex insulator spacer 21 ... Metal nut 22 ... Long screw 23 ... Lug 24 ... Metal shield cover 25 ... Metal shield bottom plate 26 ... Transformer body 27 ... Leader A
28 ... Leader line B
29 ... Insulator spacer C

Claims (1)

  The metal chassis and metal cover of the electronic device, the metal front panel, the metal back panel, and the metal bottom plate are electrically separated from each other with an insulator interposed therebetween, and the metal cover, the metal front panel, and the metal Music signal and video by eddy currents flowing by electromagnetic waves generated from parts of electronic equipment, eliminating the loop by connecting each part of the back panel and metal bottom plate to the metal chassis with a screwed metal spacer or lead wire. This is a method for dramatically reducing the sound quality and image quality of electronic devices by suppressing noise applied to signals and the like.

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