JPH114096A - Method for shielding noise - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for shielding noise by which a noise terminal voltage can be reduced by shielding an AC input line between the input terminal of an inlet and a noise filter and a grounding line between the grounding terminal of the inlet and a frame ground with a shielding sheet metal. SOLUTION: In a structure, in which commercial power is inputted to an inlet 2 attached to an enclosure and supplied to a power source section from the inlet 2 via an AC input line 7 and a noise filter and a grounding terminal 2b of the inlet 2 is connected to the frame ground 9 of the enclosure through a grounding line 8, and then, the AC input line 7 and grounding line 8 are passed through a ring-like magnetic material 4, the grounding line 8 between the grounding terminal 2b of the inlet 2 and the frame ground 9 of the enclosure and the ring-like magnetic material 4, through which the grounding line 8 and AC input line 7 are passed are shielded with a shielding sheet metal 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise shielding method using a shield metal plate at an input portion of a power supply with an inlet used in electronic equipment and the like.

[0002]

2. Description of the Related Art Conventional plasma display panels (PDs)
A method for shielding noise of a display device using P) includes, for example,
As shown in FIG. 3, a commercial power supply is input to an inlet 2 attached to the back or side surface of the housing 1 and the like.
Filter 5 from the input terminal 2a of the
AC power is supplied to the power supply unit 6 via the power supply unit 6 and connected to the frame ground 9 of the housing 1 from the ground terminal 2b of the inlet 2 by the ground line 8 while the AC input line 7 and the ground line 8 are connected to a ring-shaped magnetic material. 4 was inserted.

In the above configuration, the ring-shaped magnetic body 4 and the noise filter 5 suppress the noise mainly emitted from the PDP into the AC input line 7 and the ground line 8 to reduce the noise terminal voltage. It complied with standards such as the Electrical Appliance and Material Control Law or VCCI (Voluntary Control Council for Interference by Information Processing Equipment).

However, the PDP emits light by plasma discharge of the cell, and the discharge current reaches a maximum series ampere within several microseconds, for example, and the current value is large, and the noise emission from the panel is large. Especially 4
In the case of a large PDP of type 0 or more, the above configuration has a problem that the standard of the noise terminal voltage such as the Electrical Appliance and Material Control Law cannot be satisfied.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been described in connection with the following. It is an object of the present invention to provide a noise shielding method that can reduce a noise terminal voltage by shielding with a noise.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. A commercial power supply is input to an inlet attached to a housing, and a power supply section is connected to the inlet via an AC input line via a noise filter. The grounding terminal of the inlet is connected to a frame ground of a housing by a ground line, and the AC input line and the ground line are inserted through a ring-shaped magnetic body. The AC input line between the filters, the ground line between the ground terminal of the inlet and the frame ground of the housing, and the ring-shaped magnetic body passing through the AC input line and the ground line are shielded by a shield plate. I have.

Further, the shield sheet metal is not connected to the frame ground of the housing.

The shield sheet metal is made of phosphor bronze or tinplate.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the AC input line between the inlet and the noise filter and the ground line between the ground terminal of the inlet and the frame ground are shielded by the shield sheet metal, so that the AC input line and the ground The noise shielding method can suppress noise jumping into the line and reduce the noise terminal voltage.

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a configuration diagram illustrating a noise shielding method according to the present invention, and FIG. 2 is an enlarged perspective view of a main part showing an embodiment. In the drawing, 1 is a housing of a display device using a PDP, 2 is an inlet mounted on the back or side of the housing 1, 3 is a power cord having a grounding earth wire and composed of a three-core cord, and 3 a is connected to the power cord. Outlet that is inserted into the inlet and supplies commercial power to the device.
4 is a ring-shaped magnetic material for suppressing noise, 5 is a noise filter composed of a line filter coil and a capacitor, 6 is rectifying an AC input supplied through the noise filter, and stabilized by a constant voltage circuit or the like. A power supply unit that outputs a DC voltage and supplies DC to the panel unit 11 and the like.

An input terminal 2a provided at the inlet 2
Are connected to the noise filter 5 through the inside of the ring-shaped magnetic body 4,
An alternating current is supplied from the output side to the power supply unit 6. On the other hand, the ground wire 8 connected to the ground terminal 2b provided in the inlet 2 is configured to be connected to the frame ground 9 of the housing 1 after passing through the inside of the ring-shaped magnetic body 4. I have.

An AC input line 7 between the input terminal 2a of the inlet 2 and the noise filter 5, and a ground line 8 between the ground terminal 2b of the inlet 2 and the frame ground 9 of the housing.
Further, the ring-shaped magnetic body 4 is shielded by a shield sheet metal 10.

The shield sheet metal 10 has a box-like shape in which a square hole covering the outer periphery of the inlet 2 is provided on one side and round holes for leading the AC input line 7 and the ground line 8 are provided on the other side. And is made of a conductive material having elasticity, such as phosphor bronze or tin (tin-plated iron plate). Since the noise emitted from the PDP is on the frame of the housing, the shield plate 10 is not connected to the frame ground 9 of the housing 1.

In the above configuration, the AC input line 7 between the input terminal 2a of the inlet 2 and the noise filter 5, the ground line 8 between the ground terminal 2b of the inlet 2 and the frame ground 9 of the housing, and the ring-shaped magnetic By shielding the body 4 with the shield sheet metal 10, a noise shielding method can be achieved in which noise entering the AC input line 7 and the ground line 8 can be suppressed and the noise terminal voltage can be reduced.

[0015]

As described above, according to the present invention, the AC input line between the input terminal of the inlet and the noise filter, the ground line between the ground terminal of the inlet and the frame ground of the housing, and the ring-shaped magnetic body are shielded by a metal plate. , A noise shielding method that can suppress noise jumping into the AC input line and the ground line and reduce the noise terminal voltage.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a noise shielding method according to the present invention.

FIG. 2 is an enlarged perspective view of a main part showing an embodiment according to the present invention.

FIG. 3 is a configuration diagram of a noise shielding method according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Inlet 2a Input terminal 2b Ground terminal 3 Power cord 3a Outlet 4 Magnetic material 5 Noise filter 6 Power supply part 7 AC input line 8 Ground line 9 Frame ground 10 Shield sheet metal

Claims (3)

[Claims] 1. A commercial power supply is input to an inlet attached to a housing, the commercial power is supplied from the inlet to a power supply unit via an AC input line through a noise filter, and a ground terminal of the inlet is connected to the housing by a ground line. The AC input line and the ground line are inserted through a ring-shaped magnetic body, the AC input line between the inlet and the noise filter, the ground terminal of the inlet, and the frame ground of the housing. A noise shielding method comprising: shielding a ring-shaped magnetic body between the ground line between the AC input line and the ground line with a shield sheet metal. 2. The noise shielding method according to claim 1, wherein the shield sheet metal is not connected to a frame ground of the housing. 3. The noise shielding method according to claim 1, wherein the material of the shield sheet metal is phosphor bronze or tinplate.