JPH113058A - Unwanted radiation prevention device for plasma display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize interference electromagnetic wave radiated by driving a plasma display and to shield driving circuits. SOLUTION: The reference potential of an anode driving circuit or an auxiliary anode circuit 9 and a reference potential of a cathode driving circuit 8 are connected with each other as a common potential, which are insulated from a metallic case as a display chassis. By this constitution, it is possible to make charge and discharge current associated with panel driving flow only into the driving circuits 8, 9 and not into the metallic case 10, and the interference electromagnetic wave radiated by the driving is minimized. Further, a high shielding effect is obtained by shielding the driving circuits 8, 9 with a conductive body 14 and electrically connecting the conductive body to the metallic case 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for preventing unnecessary radiation from a plasma display.

[0002]

2. Description of the Related Art In a plasma display, a charge / discharge current required for plasma discharge flows through various driving circuits.
These drive circuits are electrically connected to each other through the housing by grounding the ground to the housing, so that the charge / discharge current required for plasma discharge flows between the various drive circuits through the housing. Was.

In addition, the electromagnetic interference emitted from the drive circuit and the signal processing circuit is blocked by a conductor, but this conductor is grounded to a metal casing which is a common ground for each drive circuit.

[0004]

In the plasma display configured as described above, since the grounds of various drive circuits are connected to the metal housing, a large charge / discharge current required for plasma discharge is generated in the metal housing. It was flowing. As a result, an interfering electromagnetic wave generated by driving the plasma display is radiated from all parts of the casing of the plasma display, and there is a possibility that the interfering electromagnetic wave may adversely affect other electronic devices. For this reason, the drive circuit and digital signal processing circuit were shielded by a conductor in order to cut off this interfering electromagnetic wave.However, since this conductor was grounded to the metal housing through which the discharge current was flowing, the The blocking effect was weak.

The discharge current flows from a certain driving circuit board to a different potential of another driving circuit board through the inside of the plasma display panel. Therefore, there is no common potential between the driving circuits, and the current between the driving circuits flows to the metal housing through the capacitor. Therefore, the ground of the driving circuit is grounded to the metal housing.

[0006]

In order to solve the above-mentioned problems, an apparatus for preventing unnecessary radiation of a plasma display according to the present invention comprises a connecting device in which reference potentials of a plurality of driving circuits are set as a common potential between the driving circuits. In this case, the reference potential of the drive circuit is connected. At this time, the reference potential of the drive circuit is insulated from the metal housing of the plasma display, and the charging / discharging current flowing by the plasma discharge is generated between the drive circuits. In this case, only the current flows, and the discharge current is prevented from flowing into the metal housing.

Further, the drive circuit is covered with a conductor, and the drive circuit is grounded to a metal housing where no charge / discharge current flows.

According to the present invention, the reference potential of the drive circuit is insulated from the metal housing, and a connection device is provided to connect the drive circuits. Since the current flows only between the driving circuits, the metal housing does not become electrically unstable, and the source of unnecessary radiation due to the charging / discharging current is limited. At this time, since the potential of the metal housing is stable, unnecessary radiation does not radiate from the metal housing itself. In addition, by shielding the drive circuit with a conductor grounded to a stable metal casing, unnecessary radiation radiated from the charge / discharge current loop can be cut off.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An unnecessary radiation preventing apparatus for a plasma display according to the present invention is characterized in that the reference potentials of a plurality of drive circuits of a plasma display are set to the same potential. It is easy to connect to.

Specifically, the apparatus for preventing unnecessary radiation of a plasma display according to the present invention is characterized in that a connection device for electrically connecting the reference potential is provided between a plurality of the driving circuits. In addition, the impedance of the charge / discharge current loop due to the discharge of plasma can be reduced, and the current can flow only between drive circuits without scattering of the loop inside and outside the plasma display.

Next, the device of the present invention is characterized in that the reference potential of the drive circuit is electrically insulated from the metal casing of the plasma display, and the charge / discharge current due to the discharge of the plasma is reduced by the metal casing. Since the flow into the body is prevented and the charge / discharge current flows only between the drive circuits, the loop of the charge / discharge current can be minimized, and unnecessary radiation can be minimized.

Next, in the apparatus for preventing unnecessary radiation of a plasma display according to claim 4 of the present invention, the metal casing is grounded, the driving circuit and the signal processing circuit are covered with a conductor, and the conductor is covered with the conductor. It is characterized in that the conductor is electrically connected to the metal casing, and the conductor is connected to the metal casing having a stable electric potential, so that a disturbance radiated from a charge / discharge current loop due to plasma discharge is generated. By shielding the electromagnetic wave with the conductor, it can be completely blocked.

(Embodiment 1) An embodiment of a device for preventing unnecessary radiation of a plasma display according to the present invention will be described below with reference to FIGS. FIG. 1 is a schematic diagram showing a flow of a charging / discharging current in a plasma display, and FIG. 2 is an arrangement diagram of a driving circuit and a metal housing of the plasma display.

In FIG. 1, taking a DC plasma display as an example, 1 is an anode drive circuit or an auxiliary anode drive circuit, and 2 is a cathode drive circuit. 3
Denotes a plasma display panel, which is a capacitive load when viewed from the driving circuit side. The discharge in the plasma display panel 3 is generated and started by a potential difference between the anode drive circuit (or the auxiliary anode drive circuit) 1 and the cathode drive circuit 2. At this time, since the plasma display panel 3 is a capacitive load, a charge / discharge current flows when a voltage is applied to the anode drive circuit (or the auxiliary anode drive circuit) 1 and the cathode drive circuit 2. This current loop is formed, for example, from the anode drive circuit 1 through the plasma display panel 3 to the cathode drive circuit 2.
And returns to the anode drive circuit 1 again by some route.

Therefore, by making the reference potential of the anode drive circuit (or auxiliary anode drive circuit) 1 equal to the reference potential of the cathode drive circuit 2, the path of the current loop can be easily changed.

In the structure of the conventional plasma display, each drive circuit (the anode drive circuit 1, the cathode drive circuit 2 and the like) is electrically connected to the metal housing 4 by the conductive pillar 7. With this structure, the charge / discharge current of the plasma display panel 3 was flowing to the metal housing 4 via the support pillar 7 as a path returning from the cathode drive circuit 2 to the anode drive circuit 1 (or the auxiliary anode drive circuit). Therefore, unnecessary radiation was emitted from the metal housing 4.

Then, by electrically connecting the drive circuits with the connecting device 6, the charging / discharging current loop of the panel is made to pass through the connecting device 6 having a low impedance, and the conductive support 7 is made of an insulating material. By doing so, it is possible to prevent the metal housing 4 from flowing.

With the above configuration, the loop of the charging / discharging current can be minimized, and the metal housing 4 can be electrically stabilized and the current loop can be minimized. Electromagnetic waves can be minimized.

FIG. 2 mainly shows the structure of a DC-type plasma display by taking a DC-type plasma display as an example. FIG. 2A is a view occupying the structure of the plasma display from the front, 8 is an anode drive circuit or an auxiliary anode drive circuit, 9 is a cathode drive circuit, and 10 is a metal housing. is there.

FIG. 2B is a sectional view of the DC type plasma display. In FIG. 2, a connection device 11 is provided between the anode drive circuit 8 (or the auxiliary anode drive circuit) and the cathode drive circuit 9 so that both are electrically connected. In addition, the conductive pillars 12 connected to the metal housing 10 may be eliminated, and each drive circuit may be insulated from the metal housing 10. Thereby, the metal casing 10
The potential does not become unstable due to the charge / discharge current, and the charge / discharge current passes through the shortest path.

(Embodiment 2) Next, another embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 3 is a view showing one structural example of the plasma display of the present invention.

In FIG. 3, reference numeral 13 denotes a plasma display panel, and the other components are the same as those of the plasma display according to the first embodiment, and therefore, the description of the reference numerals and the operation thereof will be omitted.

In FIG. 3, the reference potential of the anode drive circuit 9 or the auxiliary anode drive circuit and the reference potential of the cathode drive circuit 8 are electrically connected by a connection fitting 11,
All of the reference potentials of these drive circuits are insulated from the metal housing 10. As a result, all the charge / discharge currents accompanying the discharge pass through the drive circuit, and the potential of the metal casing 10 is always in a stable state without being shaken.

Therefore, the driving circuits 8 and 9 are
By electrically connecting the conductor 14 to the metal housing 10 having a stable potential, the conductor can also maintain a stable potential, and a high shielding effect can be obtained.

[0025]

As described above, according to the present invention, the charging / discharging current by driving the panel is made to flow only to the driving circuit and not to the metal housing, so that the potential of the metal housing is stabilized. It becomes a state, and it is possible to minimize interference electromagnetic waves radiated during driving. Further, an advantageous effect that a high shielding effect can be obtained by shielding the drive circuit with a conductor and electrically connecting the conductor to a metal housing having a stable potential can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a charge / discharge current of a plasma display.

FIG. 2 is a layout diagram of a driving circuit of a plasma display and a metal housing.

FIG. 3 is a structural diagram of a plasma display according to an embodiment of the present invention.

[Explanation of symbols]

 1,8 Anode drive circuit or auxiliary anode drive circuit 2,9 Cathode drive circuit 3 Plasma display panel 10 Metal casing 5 Charge / discharge current path 6,11 Connection device 12 Support

Claims (3)

[Claims] 1. A device for preventing unnecessary radiation of a plasma display, comprising: a connecting device for electrically connecting a reference potential between a plurality of driving circuits of a plasma display; . 2. The apparatus according to claim 1, wherein the reference potential of the drive circuit is electrically insulated from the metal housing. 3. A connection device for electrically connecting a reference potential between a plurality of drive circuits of a plasma display covered by a metal housing, grounding the metal housing, and providing the drive circuit and signal processing. An unnecessary radiation preventing device for a plasma display, wherein a circuit is covered with a conductor, and the conductor is electrically connected to the metal housing.