JP3057260B2 - Chassis structure of cathode ray tube display - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chassis structure for shielding components and circuits in a cathode ray tube display device that are subject to electromagnetic interference.

[Summary of the Invention] The present invention provides a circuit or the like on one surface of a substrate and a conductive pattern on the other surface facing a source of electromagnetic interference, thereby eliminating the use of components such as a shield case and a shield plate.
It is intended to reduce the number of parts and the number of assembling steps for the electromagnetic shield and to make the chassis structure compact.

2. Description of the Related Art In an electronic device such as a cathode ray tube display device, one of circuits or components in the device may be a source of interference and the other may be a recipient of the interference. It may be necessary to prevent interference. Conventionally, as such a chassis structure, a structure has been used in which a shield plate is mounted on a side of a substrate on which a circuit or a component which is not likely to be subjected to electromagnetic interference is attached, on the side of a source of electromagnetic interference, or the substrate is covered with a shield case.

[Problems to be Solved by the Invention] However, the use of a shield plate or a shield case not only increases the number of components, but also requires a mounting portion for mounting on the substrate, complicating the structure, increasing the number of assembly steps, and There was a problem of taking up space.

Therefore, an object of the present invention is to achieve simplification of a chassis structure, reduction of the number of parts and assembly steps, and downsizing.

[Means for Solving the Problems] According to the present invention, an opposite surface of a substrate provided with a signal system circuit or component on one surface is arranged to face a source of electromagnetic interference, and the other surface of the substrate is The configuration is such that a conductive pattern is provided in a range where a circuit or a component is affected by electromagnetic interference.

[Effect] Electromagnetic waves emitted from a source of electromagnetic interference are reflected by a conductive pattern provided on the other surface of the substrate facing the source, and components and circuits provided on one surface of the double-sided substrate are not subjected to electromagnetic interference. .

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 to 3 show an embodiment, in which the present invention is applied to a clear vision television receiver in a chassis structure. A clear vision television receiver converts a video signal for normal scanning into a video signal for double-speed scanning and reproduces the video.

FIG. 2 shows a schematic configuration diagram of a chassis structure of the television receiver. In FIG. 2, 1 is a cathode ray tube, 2
Is a deflection circuit, and 3 is a flyback transformer. The deflecting circuit 2 and the flyback transformer 3 are circuits of a double-speed scanning system. The deflecting circuit 2 applies a deflecting voltage to scan the double-speed scanning video signal as shown in FIG. A flyback pulse is generated as shown. Y for processing video signal for normal scan
Circuits or components 4 which are not susceptible to electromagnetic interference, such as a signal processing circuit and a chroma signal processing circuit, are mounted on a board 5, and this board 5 is connected to the deflection circuit 2 and the flyback transformer 3 as shown in FIG. They are arranged substantially orthogonally. That is,
The opposite surface 5a of the circuit or component 4 that is not susceptible to electromagnetic interference is arranged to face the deflection circuit 2 and the flyback transformer 3. A conductive pattern 6 is formed on an opposite surface 5a of the substrate 5 in a range where the electromagnetic wave is directly projected from the deflection circuit 2 or the flyback transformer 3 onto the circuit or component 4. In this embodiment, the conductive pattern 6 is formed in a partial area of the opposite surface 5a of the substrate 5, but may be formed in the entire area.

In the above configuration, since the electromagnetic waves radiated from the deflection circuit 2 and the flyback transformer 3 are reflected by the conductive pattern 6 of the substrate 5 facing them, the circuit or component 4 of the signal system mounted on one surface of the substrate 5 has an electromagnetic wave. It is not affected by the interference, and the noise shown by the broken line in FIG. 3 does not appear on the video signal for normal scanning.

Since the chassis structure does not use a shield plate or a shield case as in the related art, there is no need for a mounting structure for mounting the shield plate or the like on one surface of the substrate, the structure is simple, and the number of parts and assembly man-hours are reduced. Provide for reduction and space saving.

[Effects of the Invention] As is apparent from the above description, the present invention provides a signal-related component or circuit on a substrate and forms a conductive pattern on the other surface opposite to a deflection circuit which is a source of electromagnetic interference and a flyback transformer. Because it was configured to block electromagnetic interference,
This has the effect of simplifying the chassis structure, reducing the number of parts and assembling steps, and reducing the size of the device.

[Brief description of the drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a perspective view showing the arrangement of substrates, FIG. 2 is a schematic configuration diagram of a television receiver, and FIG. 3 is a waveform diagram. 1 ... circuit or signal components, 5 ... board, 5a ... opposite surface, 6 ... conductive pattern.

Claims (1)

(57) [Claims] In a chassis structure of a cathode ray tube display device, at least one of a deflection circuit and a flyback transformer, which is a source of electromagnetic interference, is provided on one surface of one or more substrates provided with signal circuits or components on one surface. Or a conductive pattern provided on the other surface of the substrate in a range where the signal circuit or component is affected by the electromagnetic interference. .