JPH0951633A - Pdp system power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent propagation of pulse noise, generated from a PDP panel drive section, to the signal processing section side by a constitution comprising a first low-pass filter inserted into a first power supply line and a second low- pass filter inserted into a second power supply line. SOLUTION: A pulse current noise generated from a panel drive section propagates on the earth line of a first power supply line 6 and arrives at a noise filter 2. In the noise filter 2, capacitors connected in parallel short-circuit the noise and a common mode choke coil connected in series blocks propagation of noise to a DC power supply 1. Consequently, the level of noise propagating to a second power supply line 7 is reduced. Similarly, the noise is reduced again through a noise filter 3 thus preventing propagation of noise furthermore.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a PDP (Plasma Display).
The present invention relates to a PDP system power supply provided with a filter that blocks the propagation of noise generated on the load side such as the Panel).

[0002]

2. Description of the Related Art As shown in a circuit diagram of an embodiment of a conventional PDP system power supply shown in FIG. 3, a pair of DC power supplies 1 and 4 provided on the secondary side of a power transformer are connected to a PDP panel side and a signal processing section, respectively. The required direct current is supplied via the power line. For example, the direct current supplied to the PDP panel drive unit 8 is converted into a required voltage and supplied to, for example, an address driver, a sustain pulse generator, etc. (both not shown) connected in the subsequent stage.

However, in the PDP panel driving section 8, as shown in FIG. 4, a maximum pulse current of about 4 A flows in each vertical scanning period (1 V), so that a noise current of large power is generated. The noise current flows through the secondary side of the power supply transformer of the DC power supply 1, so that the DC power supply 4
Flowing through the secondary side of the power transformer of the above DC fluctuation of the DC power source 4. As a result, the power supply voltage of the signal processing unit becomes unstable, and there is a problem of image quality deterioration such as screen brightness variation and beat fringes.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a PDP system power supply which does not propagate pulse noise generated in a PDP panel driving section to the signal processing section side. To do.

[0005]

In order to achieve the above object, a DC power supply for generating DC from a commercial power supply, a first power supply line for transmitting the DC power supply to a panel drive section, and a signal processing for the DC power supply. P composed of the second power supply line transmitted to the
In the DP system power supply, a first low-pass filter inserted into the first power supply line and a second low-pass filter inserted into the second power supply line are provided.

In another configuration, a first direct current power source for generating direct current from the commercial power source and transmitting the direct current to the panel drive section via the first power source line, and a second direct current source for generating direct current from the commercial power source. In a PDP system power supply configured by a second DC power supply transmitting the same DC to a panel drive unit via a power supply line, a first low-pass filter inserted and provided in the first power supply line, and the second power supply line And a second low-pass filter provided by being inserted in.

[0007]

With the above configuration, the pulse noise generated in the panel driving section is attenuated by the first low pass filter and further attenuated by the second low pass filter. Therefore, the pulse noise is prevented from propagating to the signal processing unit, and only the required DC voltage is supplied.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A PDP system power supply according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a circuit diagram of an embodiment of a PDP system power supply according to the present invention. Reference numeral 1 is a half-wave rectifier circuit composed of a diode connected in series with one end of a secondary winding of a transformer for generating direct current from a commercial power source, a cathode of the diode, and a capacitor connected in parallel with the other end of the transformer. DC power supply. Reference numeral 6 is a first power supply line for transmitting the direct current supplied from the direct current power supply 1 to the panel drive section. Reference numeral 7 is a second power supply line that is connected in parallel with the first power supply line and transmits the direct current supplied from the DC power supply 1 to the signal processing unit. 2 is the first power line 6
Is a noise filter (first low-pass filter) including a pair of common mode choke coils that are inserted in and connected to each other, and a capacitor that is connected in parallel at each input end and output end of the common mode choke coil. Reference numeral 3 is a noise filter (second low-pass filter) having a similar configuration, which is provided by being inserted into the second power supply line 7.

The operation of the PDP system power supply according to the present invention will be described with reference to FIGS. The pulsed current noise shown in FIG. 4 propagates through the ground line of the first power supply line 6 and reaches the noise filter 2 from the panel drive section. In the noise filter 2, a capacitor connected in parallel short-circuits noise, and a common mode choke coil connected in series blocks transmission to the DC power supply 1. Therefore, the second power line 7
The noise level propagating to is reduced. Similarly, the propagation of noise is blocked by the method of reducing the propagation noise again by the noise filter 3.

In the above description, the first power supply line 6 and the second power supply line 7 are connected to one DC power supply 1 to supply direct current to the panel drive section and the signal processing section. A voltage regulator or the like is provided after the noise filter 3 to generate a voltage of about 5 V used by the signal processing unit. However, the PDP system power supply according to the present invention is not limited to the above example, and may be, for example, a configuration in which a high voltage DC power supply for the panel driving unit and a 5V voltage for signal processing are separately provided.

FIG. 2 is a circuit diagram of a second embodiment of the PDP system power supply according to the present invention. The same parts as those in FIG. 1 are designated by the same reference numerals, and different parts will be described. Reference numeral 4 is a DC power supply provided for signal processing. Reference numeral 5 is an active filter that replaces the noise filter 3. In this embodiment, the noise is blocked centering on the component having large energy on the low frequency side of the noise propagated by the active filter, so that the influence of the noise on the signal processing unit can be sufficiently reduced.

[0012]

As described above, the present invention provides a PDP system power supply which does not propagate the pulse noise generated in the panel driving unit to the signal processing unit side. Therefore, since noise does not propagate to the signal processing unit side, there is an advantage that the power supply voltage of the signal processing unit is stabilized, and the problem of image quality deterioration such as conventional screen brightness variation and beat fringes can be solved.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of a PDP system power supply according to the present invention.

FIG. 2 is a circuit diagram of a second embodiment of the PDP system power supply according to the present invention.

FIG. 3 is a circuit diagram of an embodiment of a conventional PDP system power supply.

FIG. 4 is a diagram showing a noise current waveform generated by a panel driver of the PDP system.

[Explanation of symbols]

 1 DC power supply 2 Noise filter (first low-pass filter) 3 Noise filter (second low-pass filter) 4 DC power supply provided for signal processing 5 Active filter 6 First power supply line 7 Second power supply line 8 PDP panel drive section

Claims (4)

[Claims] 1. A direct current power source for generating direct current from a commercial power source, a first power source line for transmitting the direct current power source to a panel driving unit, and a second power source line for transmitting the direct current power source to a signal processing unit. In the PDP system power supply, a PDP system power supply configured by a first low-pass filter provided by being inserted into the first power supply line and a second low-pass filter being provided by being inserted in the second power supply line. 2. A pair of common mode choke coils in which the first low-pass filter and the second low-pass filter are inserted in series in a power supply line, and a capacitor connected in parallel at each input end and output end of the common mode choke coil. The PDP according to claim 1, wherein the PDP comprises a noise filter comprising
System power supply. 3. A first direct current power source for generating direct current from a commercial power source and transmitting the direct current to the panel drive section through the first power source line, and a direct current source for generating direct current from the commercial power source and passing through a second power source line. In a PDP system power supply configured by a second DC power supply that transmits the same DC to a panel driving unit, a first low-pass filter provided by being inserted into the first power supply line and a second DC power supply being provided by being inserted in the second power supply line. PDP system power supply configured with a second low pass filter. 4. A pair of common mode choke coils having the first low-pass filter inserted in series in a power supply line,
4. The PDP system power supply according to claim 3, wherein the common mode choke coil comprises a noise filter including a capacitor connected in parallel at each of an input end and an output end, and the second low pass filter is an active filter.