JP2002351379A - Plasma display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma display device in which regulation of power source voltages is improved and the reactive power of a dropper power source circuit is reduced. SOLUTION: This plasma display device has a PDP(plasma display panel) 11, a display driving circuit part performing display by impressing signals to the PDP 11 and a power source circuit part supplying a plurality of power source voltages required for the display driving circuit part. In this display device, since a flyback system secondary regeneration converter circuit 1224 which stabilizes output power source voltages by regenerating secondary-side energy at a primary side is provided in the power source circuit part and the secondary-side excessive energy is made to be regenerated at the primary side while making a voltage having a large output load and a large load fluctuation a stabilizing voltage, it is possible to keep the transmission amount of energy from the primary side to the secondary side always constant and regulation of secondary-side output voltages can be made to be stabilized output voltages.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large screen,
The present invention relates to a plasma display device known as a lightweight display device.

[0002]

2. Description of the Related Art In recent years, a plasma display device has attracted attention as a display panel (thin display device) having excellent visibility, and higher definition and a larger screen are being promoted.

[0003] This plasma display device is roughly classified into an AC type and a DC type in terms of driving, and there are two types of discharge types, a surface discharge type and a counter discharge type. Currently, due to power consumption and simplicity of manufacturing,
AC type surface discharge type plasma display devices have become the mainstream.

FIG. 11 shows a structure of a PDP panel in a plasma display device. As shown in FIG. 11, on a transparent front substrate 1 such as a glass substrate, a plurality of rows of stripe-shaped display electrodes 2 formed of pairs of scan electrodes and sustain electrodes are formed, and cover the electrode group. The dielectric layer 3 is formed as described above, and a protective film 4 is formed on the dielectric layer 3.

[0005] A plurality of columns covered with an overcoat layer 6 are provided on a rear substrate 5 opposed to the front substrate 1 so as to cross the display electrodes 2 of scan electrodes and sustain electrodes. Are formed. A plurality of barrier ribs 8 are arranged on the overcoat layer 6 between the address electrodes 7 in parallel with the address electrodes 7, and the phosphor layers 9 are provided on the side surfaces between the barrier ribs 8 and on the surface of the overcoat layer 6. I have.

The substrate 1 and the substrate 5 are provided with a display electrode 2 of a scan electrode and a sustain electrode and an address electrode 7.
Are arranged so as to be substantially orthogonal to each other with a minute discharge space interposed therebetween, the periphery thereof is sealed, and one or a mixed gas of helium, neon, argon, and xenon is discharged in the discharge space. Sealed as gas. The discharge space is divided into a plurality of sections by the partition walls 8, so that a plurality of discharge cells are provided at intersections between the display electrodes 2 and the address electrodes 7, and each of the discharge cells has a red, green, and blue color. The phosphor layers 9 are sequentially arranged one by one so that

FIG. 12 shows an electrode arrangement of this PDP panel. As shown in FIG. 12, scan electrodes, sustain electrodes, and address electrodes have a matrix configuration of M rows × N columns, and M rows of scan electrodes SCN are arranged in the row direction.
1 to SCNM and sustain electrodes SUS1 to SUSM are arranged, and N columns of address electrodes D1 to DN are arranged in the column direction.

In the PDP panel having such an electrode configuration, an address discharge is performed between the address electrode and the scan electrode by applying a write pulse between the address electrode and the scan electrode, and after selecting a discharge cell, By applying a periodic sustain pulse that is alternately inverted between the scan electrode and the sustain electrode, a sustain discharge is performed between the scan electrode and the sustain electrode to perform a predetermined display.

FIG. 13 shows an electric circuit of a conventional plasma display device. The plasma display device A00 mainly includes a PDP panel A1, a noise filter A21, an AC-DC power supply circuit A22, a down-converter power supply circuit A3, A standby power supply circuit A4, a microcomputer A5, a PDP drive circuit A61, a video processing circuit A62,
It consisted of a video / audio input circuit A7. Note that the audio processing circuit A63 and the speaker A8 may be provided.

This plasma display device is a commercial A
C power supply A9, rectified by a noise filter A21, a power factor improvement circuit A221, and a rectifier circuit A222, and a plurality of AC-DC converter circuits, for example, an AC-DC converter circuit A223 and an AC-DC converter circuit A22.
The power supply was composed of two converters of No. 4 and each winding power supply output supplied power required by a dropper power supply circuit A31 and a chopper power supply circuit A32.

[0011]

However, in such a plasma display device, the power load of the PDP panel greatly fluctuates between an all black display state and an all white display state. For example, in a PDP panel having a 42-inch display screen, it fluctuates greatly from about 10 W to about 200 W. In addition, in order to display the PDP panel by discharging,
As the sustaining voltage Vsus, for example, 200 V, as a data voltage Vdata required to discharge a predetermined pixel,
For example, a high voltage such as 65 V is required.

Therefore, a forward or flyback AC-DC power supply for supplying the sustaining voltage Vsus.
A dedicated converter circuit is used to stabilize output voltage regulation. Also, when there are many winding outputs, a flyback type AC-DC converter circuit is used, and the dropper power supply circuit smoothes the voltage at a point where the regulation of the output voltage other than the feedback winding output becomes insufficient. Was. That is, in FIG.
For example, as for the data voltage Vdata, the winding output of the AC-DC converter circuit A224 is smoothed and stabilized by the dropper power supply circuit A31.

In a PDP panel having a 42-inch display screen, for example, when the average current is 1 A when displaying all white at 65 V, a power loss of about 3 to 5 W occurs in the dropper power supply circuit,
In addition, when displaying all black, the average current is about 0.1 A, and the input voltage (winding output) has a large voltage fluctuation of 68 V (when completely white) to 100 V (all black).
If a dropper power supply circuit is used in a PDP panel having a 50-inch display screen, the power loss is about 10 W, so there is a problem that it is necessary to provide a dedicated AC-DC converter circuit to reduce the power loss. .

Further, as described above, the discharge sustaining voltage Vsus has a large power and a large load fluctuation.
There is a problem in terms of cost that the DC converter circuit A223 must be provided.

An object of the present invention is to provide a plasma display device which solves such problems, improves regulation of power supply voltage, and can reduce reactive power of a dropper power supply circuit.

[0016]

In order to achieve the above-mentioned object, a plasma display device according to the present invention comprises a pair of substrates having at least front surfaces transparent to each other so as to form a discharge space between the substrates, and to the substrates. A panel on which an electrode group is arranged, a display drive circuit unit for applying a signal to the panel to perform display, and a power supply circuit unit for supplying power to the display drive circuit unit; This configuration has a flyback type secondary converter circuit for stabilizing the output power supply voltage by regenerating the secondary energy to the primary side.

According to the present invention, the secondary converter transmits the maximum energy to the secondary side, and the excess energy is regenerated to the primary side.
It is possible to provide a plasma display device that can stabilize the output voltage of each secondary winding and reduce power consumption in a dropper power supply circuit provided in a subsequent circuit.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS That is, according to the first aspect of the present invention, at least a pair of substrates having transparent front surfaces are opposed to each other so that a discharge space is formed between the substrates, and an electrode group is arranged on the substrates. Panel, a display drive circuit unit for applying a signal to the panel to perform display, and a power supply circuit unit for supplying a drive voltage to the display drive circuit unit. This is a configuration using a flyback type secondary converter that stabilizes the output power supply voltage by regenerating energy to the primary side.
Next time the raw converter will transfer the maximum energy to the secondary side,
Since the excess energy is regenerated to the primary side, the output voltage of each secondary winding of the transformer can be stabilized, and the power consumption in the dropper power supply circuit provided in the subsequent circuit can be reduced.

In this configuration, a plurality of A
Using a C-DC converter circuit and a plurality of AC-DC
At least one of the converter circuits may be configured to use a flyback type secondary converter circuit.

The invention according to claim 3 of the present invention is characterized in that
The output of the next raw converter circuit is at least the power supply voltage for driving the PDP panel, the power supply voltage for the video processing circuit, and the power supply voltage for the microcomputer, and is configured to regenerate the power supply voltage for driving the PDP panel. The load fluctuation of the power supply voltage is large and the power at the maximum load is larger than the other winding voltage outputs, and the maximum energy of the power supply voltage for driving the PDP panel is transmitted to the secondary side,
Since excess energy is regenerated to the primary side, the transformer itself has a substantially constant output from light load to maximum load, and the output voltage of each secondary winding can be stabilized,
This has the effect of reducing the power consumption of the dropper power supply circuit provided in the subsequent circuit.

According to a fourth aspect of the present invention, the output for the sustaining voltage of the PDP panel is regenerated, and the sustaining voltage of the plasma display has a maximum load at the transformer winding output. Voltage, 2
Next time the raw converter will transfer the maximum energy to the secondary side,
Since excess energy is regenerated to the primary side, the output voltage of each secondary winding of the transformer can be stabilized, the power consumption of the dropper power supply circuit provided in the subsequent circuit can be reduced, and a single flywheel can be used. 2nd raw converter of buck type is realized,
This has the effect of reducing the number of parts.

Further, the invention according to claim 5 of the present invention provides:
A PDP panel in which at least a pair of substrates whose front sides are transparent are opposed to each other so that a discharge space is formed between the substrates, and an electrode group is disposed on the substrates; And a power supply circuit section for supplying a drive voltage to the display drive circuit section. The power supply circuit section stabilizes the output power supply voltage by regenerating the energy of the secondary side to the primary side at light load. And a flyback partial secondary converter circuit for transmitting energy to the secondary side by a normal flyback method under heavy load is provided.
-The DC converter circuit has a relatively stable voltage regulation from a medium load to a heavy load. Sufficient voltage regulation from a light load to a heavy load can be obtained by performing the secondary operation only at a light load. Hysteresis loss of transformer and copper loss of winding at middle load to heavy load due to second generation, and reduction of second generation switching circuit loss, downsizing of transformer and reduction of current capacity of partial second generation switching circuit. Has the effect of being able to.

In this configuration, a plurality of A
Using a C-DC converter circuit and a plurality of AC-DC
At least one of the converter circuits may be configured to use a flyback type secondary converter circuit.

According to a seventh aspect of the present invention, the output of the partial secondary conversion converter circuit is at least a power supply voltage for driving a PDP panel, a power supply voltage for a video processing circuit, and a power supply voltage for a microcomputer. The power supply voltage is configured to be stabilized and regenerated, and P
The load fluctuation of the power supply voltage for driving the DP panel is large, and the power at the maximum load is larger than the output of the other winding voltage. In order to prevent the phenomenon that the other winding voltage decreases, the energy is transmitted to the secondary side to suppress the decrease of the other winding voltage, and the excess energy of the power supply voltage for driving the PDP panel is regenerated to the primary side. By doing so, the output voltage of each secondary winding can be stabilized,
This has the effect of reducing the power consumption of the dropper power supply circuit provided in the subsequent circuit.

In the invention according to claim 8 of the present invention, the power supply circuit section includes a partial second-generation converter circuit and a flyback AC-DC converter circuit,
The switching frequency of the next raw converter circuit is set to the AC
-The switching frequency of the AC-DC converter circuit is lower than the switching frequency of the DC converter circuit, and the groaning sound of the transformer generated when the switching frequency of each AC-DC converter circuit is close by separating the switching frequency range of the AC-DC converter circuit. It has the effect that it can be prevented.

According to a ninth aspect of the present invention, the output for the sustaining voltage of the PDP panel is regenerated, and the sustaining voltage of the plasma display has the maximum load at the transformer winding output. Voltage, the output voltage of each secondary winding of the transformer can be stabilized, the power consumption of the dropper power supply circuit provided in the circuit at the subsequent stage can be reduced, and the regenerative operation is performed only at a light load. Hysteresis loss of transformer and copper loss of winding during medium load to heavy load due to next generation, reduction of second generation switching circuit loss, downsizing of transformer and reduction of current capacity of partial second generation switching circuit Has a function of realizing the flyback type partial second-order converter and reducing the number of parts.

Embodiment 1 Hereinafter, a plasma display device according to Embodiment 1 of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

FIG. 1 shows a circuit configuration of a main part of a plasma display device according to a first embodiment of the present invention. As shown in FIG.
Mainly includes a PDP panel 11 having a configuration shown in FIGS. 11 and 12, a display drive circuit unit for applying a signal to the PDP panel 11 for display, and a power supply circuit unit for supplying a drive voltage to the display drive circuit unit. Have.

More specifically, a noise filter 121, an AC-DC power supply circuit 122, a down-converter power supply circuit 13, a standby power supply circuit 14, a microcomputer 15 as a control unit, and a display drive circuit unit, which constitute a power supply circuit unit, are constituted. It comprises a PDP drive circuit 161, a video processing circuit 162, and a video / audio input circuit 17. Note that the audio processing circuit 1
63, and a speaker 18 may be provided.

This plasma display device is a commercial A
C power supply 19, noise filter 121, AC-
A power factor improving circuit 1221, which constitutes the DC power supply circuit 122,
Rectified by a rectifier circuit 1222, and then a plurality of AC-D
C converter, for example, AC-DC converter circuit 122
The voltage is converted through the two converters of the third and second raw converter circuits 1224, and the output of each winding power supply is supplied to the dropper power supply circuit 131 and the chopper power supply circuit 1 respectively.
At 32, the voltage is down-converted to supply a plurality of necessary power supply voltages.

FIG. 2 shows the configuration of the second-order raw converter circuit 1224. A rectifier circuit 1222 including a bridge diode D1222 and a smoothing capacitor C1222
The power supply 19 is rectified and the second-time raw converter circuit 1224
And outputs, for example, 65 V as a data voltage Vdata necessary for discharging a predetermined pixel and 17 V to a dropper power supply circuit 131 constituting the down converter power supply circuit 13, and a chopper power supply circuit (not shown) A predetermined voltage Vosig, for example, 13 V is output to 132. Power supply for audio processing V + s, V-s, for example, 12V, -1
2V directly outputs the winding output. The dropper power supply circuit 131 has a driving voltage Vdr for the plasma display device.
v, for example, to 15 V to drive the plasma display.

The main configuration of the second-generation raw converter circuit 1224 includes a switching transformer 21, an AC-DC converter control circuit 22, a second-generation raw drive circuit 23, a switching MOSFET Q21, and a regenerative MOSFET Q22.

The primary winding (1) of the switching transformer 21
The current is turned on / off by the switching MOSFET Q21 (between -2 pins), and energy is transmitted to the secondary side and primary side power supply windings (between pins 3-4). The output of the primary-side power supply winding (between pins 3 and 4) is rectified by a diode D21 and a capacitor C21, and the output of AC-
Power is supplied to the DC converter control circuit 22. The secondary side power supply winding outputs are respectively a regenerative MOSFET Q22 and a body diode, diodes D23, D24, D25, D
26, are rectified by the capacitors C22, C23, C24, and C25, and are supplied to the subsequent circuit as a power supply output. The switching operation is performed at a fixed switching frequency of, for example, 80 kHz.

The six pins of the data voltage Vdata winding (between pins 5 and 6) which output a data voltage Vdata having a large output load and a large load variation as a stabilized voltage are connected to the regenerative M.
A regenerative MOSF connected to the drain of OSFET Q22
The source of ETQ22 is grounded. The switching on / off timing is determined by the switching transformer 21
Detected from the pin voltage, the regenerative MOSFET Q22 is turned on by the secondary regenerative drive circuit 23 during the switching off period to regenerate the energy on the secondary side to the primary side.

FIG. 3 shows the circuit configuration of the second-generation raw drive circuit 23. Input and output are data voltage V for voltage detection as input.
data, a voltage Vosig for driving the regenerative MOSFET Q22,
The 9 pin voltage of the switching transformer 21 is used for switching ON / OFF discrimination, and a regenerative MOSFET is used as an output.
This is a configuration using the gate voltage of Q22. Data voltage V
The shunt regulator IC determines whether the data voltage is high or low.
31, resistors R321 and R for dividing the data voltage Vdata
322 and resistors R319 and R320, and the output is input to the gate of an NPN transistor Q32 for turning on / off the regenerative operation via the resistor R319.

The on / off driving of the regenerative MOSFET Q22 is performed by using the voltage of the pin 7 of the switching transformer 21 and the PNP.
This is performed by the transistor Q31, and the diodes D31 and D3
2, D33, D34, D35, D36, resistor R311,
R312, R313, R314, R315, R316,
A capacitor C31 is connected for the time constant of R317, R318 and the NPN transistor Q32.

The regeneration operation will be described below. The divided voltage of the data voltage Vdata is input to the reference terminal of the shunt regulator IC31. When the data voltage Vdata decreases, the shunt regulator IC31 is turned off.
Is applied through resistors R319 and R320. During the ON period of the primary-side switching MOSFET Q21, the potential of the ninth pin of the transformer 21 is negative,
SFET Q22 is off below the threshold voltage. 1
During the off period of the secondary-side switching MOSFET Q21,
2 through the body diode of the regenerative MOSFET Q22
As the current starts to flow to the next side, the potential of the ninth pin of the transformer 21 becomes positive (above the threshold voltage) and the regenerative MO
SFET Q22 turns on. Therefore, the regenerative MOSF
A current also flows through the ETQ 22 to supply energy to the secondary side.

On the other hand, the capacitor C31 is charged and NP
When the base threshold voltage of the N transistor Q32 is reached, N
The PN transistor Q32 becomes conductive. As a result, the gate voltage of the regenerative MOSFET Q22 decreases and is turned off, so that the current stops when the direction of the current flowing to the regenerative MOSFET Q22 changes from the drain to the source.
That is, the regenerative operation stops, and the operation becomes the same as that of the normal flyback method.

When the data voltage Vdata rises, the shunt regulator IC31 is turned on, so that the gate voltage of the NPN transistor Q32 becomes lower than the threshold value and is turned off. During the ON period of the primary-side switching MOSFET Q21, the potential of the ninth pin of the transformer 21 is negative, and the regenerative MOSFET Q22 is at or below the threshold voltage and is off. During the off period of the primary-side switching MOSFET Q21, current starts to flow to the secondary side through the body diode of the regenerative MOSFET Q22, and the potential of the ninth pin of the transformer 21 becomes positive (above the threshold voltage), and the regenerative MOSFET Q22 turns on. Transformer 21
Since the regenerative MOSFET Q22 is on until the potential of the ninth pin becomes negative (below the threshold voltage), the current of the regenerative MOSFET Q22 continues to flow, the current in the direction from the source to the drain monotonously decreases, and the A reverse current flows and increases monotonically.

That is, the flow of the reverse current on the secondary side causes energy to be stored in the transformer 21.
The stored energy is used for the primary side switching MO.
It is regenerated to the primary side during the ON period of the SFET Q21. For example, if the output load of the data voltage Vdata is zero, 1
The energy transmitted to the secondary side during the off-period of the secondary-side switching MOSFET Q21 is temporarily stored in the capacitor C22, but is immediately returned to the transformer 21, and
An operation of regenerating to the primary side during the ON period of the secondary side switching MOSFET Q21 is performed. Therefore, the amount of energy transmitted from the primary side to the secondary side is always constant, and the regulation of the secondary winding output voltage becomes stable.

Embodiment 2 Hereinafter, a plasma display device according to Embodiment 2 of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

FIG. 4 shows a main circuit configuration of a plasma display device 400 according to a second embodiment of the present invention. 4, a PDP panel 11, a noise filter 121, a standby power supply circuit 14, a microcomputer 15, a PDP drive circuit 161, a video processing circuit 162, a video / audio input circuit 17, an audio processing circuit 163, a speaker 1
8 is the same as FIG.

This plasma display device 400 has
Connected to the commercial AC power supply 19, the noise filter 121,
Power factor improvement circuit 122 as AC-DC power supply circuit 41
1. A single AC-D rectified by the rectifier circuit 1222
Second-generation raw converter circuit 411 which is a C converter circuit
, And each winding power supply output is down-converted by a dropper power supply circuit 421 and a chopper power supply circuit 132 to supply a plurality of necessary power supply voltages.

FIG. 5 shows the configuration of the second-order raw converter circuit 411. The commercial AC power is rectified by the rectifier circuit 1222 including the bridge diode D1222 and the smoothing capacitor C1222, and is supplied to the secondary converter circuit 1224. Discharge sustaining voltage Vsus for maintaining plasma discharge
For example, 180V, down converter power supply circuit 4
2, for example, 14
For example, 67V is output to the 2V dropper power supply circuit 4212, 17V is output to the dropper power supply circuit 4213, and a predetermined voltage Vosig, for example, 13V, is output to the chopper power supply circuit 1312 (not shown). Power supply for audio processing V +
s, V-s, for example, 12V and -12V, directly output the winding output.

The dropper power supply circuit 4211 has a BK voltage Vbk required to reset the discharge state, for example, 140
V, and the dropper power supply circuit 4212 converts the data voltage V
data, for example, to 65 V,
Reference numeral 3 converts the driving voltage Vdrv of the plasma display to, for example, 15 V, and drives the plasma display.

The main components of the second-order raw converter circuit 411 are a switching transformer 51, an AC-DC converter control circuit 52, a second-order raw drive circuit 53, a switching M
It comprises an OSFET Q51 and a regenerative MOSFET Q52.

The primary winding (1) of the switching transformer 51
The current is turned on / off by the switching MOSFET Q <b> 51 between the (−2 pins) and the energy is transmitted to the secondary-side and primary-side power supply windings (between the 3 and 4 pins). The output of the primary-side power supply winding (between pins 3 and 4) is rectified by a diode D51 and a capacitor C51, and AC-
Power is supplied to the DC converter control circuit 52. The secondary power supply winding outputs are respectively a regenerative MOSFET Q52, body diodes D54, D55, D56, and a capacitor C5.
2, rectified by C53, C54, and C55, and supplied to a subsequent circuit as a power supply output. The switching operation is performed at a fixed switching frequency of, for example, 80 kHz.

Six pins of the discharge sustain voltage Vsus winding (between pins 5 and 6) which output the discharge sustain voltage Vsus having a large output load and a large load variation as a stabilizing voltage are connected to the drain of the regenerative MOSFET Q52. Regenerating MO
The source of SFET Q52 is grounded. Switching on / off timing is determined by the switching transformer 5
The power is detected from the 9th pin voltage 1, and the regenerative MOSFET Q52 is turned on during the switching off period by the second-generation regenerative drive circuit 53 to regenerate the energy on the secondary side to the primary side.

The operation of the second generation is almost the same as that of the first embodiment. In the second embodiment, the second generation is performed at the discharge sustaining voltage Vsus winding voltage having the secondary maximum load. Are different. In addition, since the output load of the discharge sustaining voltage Vsus and the data voltage Vdata increase and decrease occur at the same timing, the voltage regulation of the data voltage Vdata, which is a winding output that is not regenerated at light load, can be obtained stably. AC-DC with one part 2nd time raw converter circuit
A converter circuit can also be configured.

Embodiment 3 Hereinafter, a plasma display device according to Embodiment 3 of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

FIG. 6 shows a main circuit configuration of a plasma display device 600 according to the third embodiment of the present invention. In FIG. 6, the PDP panel 11, the noise filter 121, the down converter power circuit 13, the standby power circuit 14, the microcomputer 15, the PDP drive circuit 161, the video processing circuit 162, the video / audio input circuit 17,
The audio processing circuit 163 and the speaker 18 are the same as those in FIG.

This plasma display device 600 is
Connected to the commercial AC power supply 19, the noise filter 121,
Power factor improvement circuit 122 as AC-DC power supply circuit 61
1. A plurality of AC-Ds rectified by the rectifier circuit 1222
C converter, for example, AC-DC converter circuit 122
3. Partial conversion is performed through the two converters of the secondary converter circuit 611, and the output of each winding power supply is down-converted by the dropper power supply circuit 131 and the chopper power supply circuit 132, and the necessary plural power supply voltages are converted. It is a configuration to supply power.

FIG. 7 shows the configuration of the partial second-order raw converter circuit 611. In the figure, a rectifier circuit 1222, a bridge diode D1222, a smoothing capacitor C122
2. Switching MOSFET Q21, regenerative MOSFET
TQ22, diodes D21, D23, D24, D2
5, D26, capacitors C21, C22, C23, C2
4, C25, C26, and the dropper power supply circuit 131 are the same as those in FIG.

A rectifier circuit 1222 comprising a bridge diode D1222 and a smoothing capacitor C1222
The power supply 19 is rectified and the partial second-time raw converter circuit 61
1 is output to the dropper power supply circuit 131 constituting the down converter power supply circuit 130 as a data voltage Vdata (for example, 65 V), and a predetermined voltage Vosi is supplied to a chopper power supply circuit 1312 (not shown).
g, for example, 13V is output. Power supply for audio processing V + s, V-
s, for example, 12V and -12V output the winding output directly. The dropper power supply circuit 131 converts the driving voltage Vdrv of the plasma display to, for example, 15 V, and drives the plasma display.

The main configuration of the partial second-generation raw converter circuit 611 includes a switching transformer 71, an AC-DC converter control circuit 72, a partial second-generation raw drive circuit 73, a switching MOSFET Q21, and a regenerative MOSFET Q22.

The primary winding (1) of the switching transformer 71
The current is turned on / off by the switching MOSFET Q21 (between -2 pins), and energy is transmitted to the secondary-side and primary-side power supply windings (between the 3-4 pins). The output of the primary-side power supply winding (between pins 3 and 4) is rectified by a diode D21 and a capacitor C21, and AC is output as a primary-side power supply
-Power is supplied to the DC converter control circuit 72. The secondary side power supply winding outputs are respectively a regenerative MOSFET Q22 and a body diode, diodes D23, D24, D25,
It is rectified by D26 and capacitors C22, C23, C24, and C25, and is supplied to a subsequent circuit as a power supply output. The switching frequency is, for example, 40 kHz to 55 kHz.
Thus, the switching operation is performed. In addition, the switching frequency of the AC-DC converter circuit 1223 is operated at, for example, 65 kHz to 100 kHz, thereby preventing the growling sound of the transformer.

A data voltage Vdata having a large output load and a large load variation is output as a stabilizing voltage, and the data voltage Vdata is supplied to the primary side by a diode D71, a shunt regulator IC71, and resistors R71, R72, and R73. Voltage feedback. In addition, the 6th pin of the data voltage Vdata winding (between the 5th and 6th pins) is connected to the drain of the regenerative MOSFET Q22.
The source of the FET Q22 is grounded.

The switching on / off timing is detected from the pin 9 voltage of the switching transformer 71. When the secondary side load is light, the regenerative MOSFET Q22 is turned on by the second generation driving circuit 73 during the switching off period. The energy of the secondary side is regenerated to the primary side. In the case of a medium to heavy load, the flyback drive with voltage feedback is performed. Therefore, since there is no regenerative operation at a medium to heavy load, the copper loss and the hysteresis loss of the transformer can be reduced, so that the flyback transformer can be used in the size of a normal flyback transformer.

FIG. 8 shows a circuit configuration of the partial second-generation raw drive circuit 73. For input and output, the voltage Vosig is used as an input for voltage detection and for driving the regenerative MOSFET Q22, and the switching transformer 71 is used for switching on / off discrimination.
Of the regenerative MOSFET Q2
This is a configuration using a gate voltage of 2.

The determination of the level of the voltage Vosig is made up of a shunt regulator IC 81, resistors R820, R821, R822 and a resistor R819 for dividing the voltage Vosg. Is input to the gate of the NPN transistor Q82 to be turned off. The on / off drive of the regenerative MOSFET Q22 is performed by the 9-pin voltage of the switching transformer 71 and the PNP transistor Q81, and the diodes D81, D82,
D83, D84, D85, D86, resistors R811, R8
12, R813, R814, R815, R816, R8
17, a capacitor C81 is connected for the time constant of R818 and the NPN transistor Q82.

The operation of the regeneration will be described below. Voltage Vosig
Is connected to the cathode terminal of the shunt regulator IC 81 and the resistor R819 through the resistor R820.
The resistors R819 and R820 are connected in series between the anode terminal and the cathode terminal of the shunt regulator IC 81, and the connection point between the resistors R819 and R820 is input to the reference terminal of the shunt regulator IC 81.

That is, when the voltage Vosig decreases, the cathode current of the shunt regulator IC 81 is fixed, so that the injection current into the base of the NPN transistor Q82 decreases. Since the time constant capacitor C81 is connected between the base and the emitter of the NPN transistor Q82, the conduction rise time of the NPN transistor Q82 is delayed.

On the other hand, when the voltage Vosig increases, the current injected into the base of the NPN transistor Q82 increases because the cathode potential of the shunt regulator IC 81 is fixed. Since the time constant capacitor C81 is connected between the base and the emitter of the NPN transistor Q82, the conduction rise time of the NPN transistor Q82 is shortened.

When the output load of the data voltage Vdata is a light load, the switching frequency increases and the on-period and the off-period of the primary-side switching MOSFET Q21 become shorter because the data voltage Vdata is a feedback voltage. At this time, the output load of the voltage Vosig does not greatly change, so that the voltage Vosig decreases. Therefore, as described above, the conduction rise time of NPN transistor Q82 is delayed.

The operation will be described below. During the ON period of the primary-side switching MOSFET Q21, the potential of the ninth pin of the transformer 71 is negative,
The ETQ 22 is off below the threshold voltage. During the off period of the primary-side switching MOSFET Q21, a current starts to flow to the secondary side through the body diode of the regenerative MOSFET Q22, and the potential of the ninth pin of the transformer 71 becomes positive (threshold voltage or more).
ETQ22 turns on. Therefore, the regenerative MOSFET
Current also flows through Q22 to supply energy to the secondary side.

On the other hand, although the capacitor C81 is being charged, the conduction rise time of the NPN transistor Q82 is delayed, so that it cannot reach the base threshold voltage.
NPN transistor Q82 is kept off.
As a result, the gate voltage of the regenerative MOSFET Q22 is held and the ON state is maintained.
Current continues flowing even if the direction of the current flowing to
To store energy. Next primary side switching MO
This energy is regenerated during the ON period of the SFET Q21.

When the output load of the data voltage Vdata is a medium to heavy load, the switching frequency is reduced and the on-period and off-period of the primary-side switching MOSFET Q21 are lengthened because the data voltage Vdata is a feedback voltage. At this time, since the output load of the voltage Vosig does not change significantly, the voltage Vosig rises. Therefore, as described above, the conduction rise time of NPN transistor Q82 is shortened.

Also, the next primary-side switching MOSFE
During the ON period of the TQ21, the potential of the ninth pin of the transformer 71 is negative, and the regenerative MOSFET Q22 is at or below the threshold voltage and is off. Primary side switching MOS
During the off period of the FET Q21, the regenerative MOSFET Q22
A current starts to flow to the secondary side through the body diode, and the potential of the ninth pin of the transformer 71 becomes positive (above the threshold voltage), and the regenerative MOSFET Q22 is turned on. Therefore, a current also flows through the regenerative MOSFET Q22 to supply energy to the secondary side.

Then, as the capacitor C81 is charged and the conduction rise time of the NPN transistor Q82 is shortened, the voltage reaches the base threshold voltage, and the NPN transistor Q82 changes from non-conduction to conduction. As a result,
Since the PNP transistor Q81 is turned on and becomes conductive, the gate voltage of the regenerative MOSFET Q22 becomes equal to or lower than the threshold value and is turned off. Therefore, the regenerative MOSFET Q2
When the direction of the current flowing to 2 changes from source → drain to drain → source, the current stops. That is,
The regenerative operation stops, and the operation becomes the same as that of the normal flyback method.

As can be understood from the above description, the data voltage V at which voltage regulation becomes a problem in the flyback system is considered.
When the output load of data is light, the energy on the secondary side is regenerated, preventing the voltage regulation of the winding output from lowering. When the output load of the data voltage Vdata is medium to heavy, the voltage regulation is normally It keeps flowing and becomes equivalent to the flyback voltage regulation.

Embodiment 4 Hereinafter, a plasma display device according to Embodiment 4 of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

FIG. 9 shows a main circuit configuration of a plasma display device 900 according to the fourth embodiment of the present invention. In FIG. 9, the PDP panel 11, the noise filter 121, the down converter power circuit 42, the standby power circuit 14, the microcomputer 15, the PDP drive circuit 161, the video processing circuit 162, the video / audio input circuit 17,
The audio processing circuit 163 and the speaker 18 are the same as those in FIG. 1, and the down converter power supply circuit 42 is the same as in FIG.

This plasma display device 900
Connected to the commercial AC power supply 19, the noise filter 121,
As the AC-DC power supply circuit 91, a power factor correction circuit 122
1. A single AC-D rectified by the rectifier circuit 1222
The power is converted through the second-stage raw converter circuit 911 which is a C converter power supply circuit, and the output of each winding power supply is down-converted by the dropper power supply circuit 421 and the chopper power supply circuit 132 to supply a plurality of necessary power supply voltages. I do.

FIG. 10 shows the configuration of the partial second-order raw converter circuit 911. The commercial AC power supply 19 is rectified by the rectifier circuit 1222 including the bridge diode D1222 and the smoothing capacitor C1222, and is supplied to the partial second-generation converter circuit 911. The discharge sustaining voltage Vsus for maintaining the plasma discharge is, for example, 180 V, and the dropper power supply circuit 4211 constituting the down converter power supply circuit 42
For example, a 142V, dropper power supply circuit 4212, for example, 67V, a dropper power supply circuit 4213, for example, 17V
V and outputs a chopper power supply circuit 131 (not shown).
2, a predetermined voltage Vosig, for example, 13 V is output. The audio processing power supplies V + s and V-s, for example, 12 V and -12 V output the winding output directly.

The dropper power supply circuit 4211 converts the BK voltage Vbk and 140 V necessary to reset the discharge state, and the dropper power supply circuit 4212 converts the data voltage Vdata,
The voltage is converted to 65 V, and the dropper power supply circuit 4213 converts the voltage to a driving voltage Vdrv for the plasma display, for example, 15 V, and drives the plasma display.

The main configuration of the partial second-generation converter circuit 911 includes a switching transformer 101, an AC-DC converter control circuit 102, a second-generation raw drive circuit 103, a switching MOSFET Q101, and a regenerative MOSFET Q1.
02.

The primary winding (between pins 1-2) of the switching transformer 101 is connected to a switching MOSFET Q10.
The current is turned on / off by 1 to transfer energy to the secondary side and primary side power supply windings (between pins 3 and 4). The output of the primary-side power winding (between pins 3 and 4) is a diode D5
1. The power is rectified by the capacitor C51 and supplied to the AC-DC converter control circuit 102 as a primary power supply. 2
The output of the secondary side power supply winding is
2, and rectified by the body diodes D54, D55, D56, capacitors C52, C53, C54, and C55, and are supplied to a subsequent circuit as a power supply output. The switching operation is performed at a switching frequency of, for example, 65 kHz to 100 kHz.

Further, a sustaining voltage Vsus having a large output load and a large load variation is output as a stabilizing voltage, and the sustaining voltage Vsus is a diode D101, a shunt regulator IC101, and resistors R101 and R10.
2. The voltage is fed back to the primary side at R103. In addition, pin 6 of the discharge sustaining voltage Vsus winding (between pins 5 and 6) is connected to the drain of the regenerative MOSFET Q102, and the source of the regenerative MOSFET Q102 is grounded.

The switching on / off timing is detected from the voltage at pin 9 of the switching transformer 101,
When the secondary load is a light load, the regenerative MOSFET Q102
Is turned on to regenerate the energy on the secondary side to the primary side. In the case of a medium to heavy load, the flyback drive with voltage feedback is performed. Therefore, since there is no regenerative operation at a medium to heavy load, the copper loss and the hysteresis loss of the transformer can be reduced, so that the flyback transformer can be used in the size of a normal flyback transformer.

The operation of the second generation is almost the same as that of the third embodiment. In the fourth embodiment, the second generation is performed at the discharge sustaining voltage Vsus winding voltage having the secondary maximum load. Are different. Further, the sustaining voltage Vsus and the data voltage Vd
Since the increase or decrease of the output load of ata occurs at the same timing, the voltage regulation of the data voltage Vdata, which is the winding output that is not regenerated at light load, can be obtained stably, and the single-part 2nd-order raw converter circuit can be used. It can be constituted by an AC-DC converter circuit.

As can be seen from the above description, when the output load of the discharge sustaining voltage Vsus at which the voltage regulation becomes a problem in the flyback method is a light load, the energy on the secondary side is regenerated and the voltage regulation of the winding output is reduced. When the output load of the data voltage Vsus is medium to heavy load, the voltage regulation continues to flow normally and becomes equivalent to the flyback type voltage regulation.

In the above description, the number of outputs on the secondary side of the transformer is determined and described. However, the number of outputs is not limited, and the present invention can be similarly implemented even if there is an increase or decrease in the circuit configuration.

[0083]

As is apparent from the above description, according to the plasma display device of the present invention, of the energy transmitted from the primary side to the secondary side, excess energy is regenerated to the primary side. Therefore, the voltage regulation of the multi-output AC-DC converter circuit having a large output load and a winding output having a large load variation can be stabilized, and the power loss due to the dropper-power supply circuit can be reduced. Can be

In addition, if the power consumption of the plasma display device is about 200 W, a single AC-DC converter circuit may be used instead of a plurality of AC-DC converter circuits.
The C-DC power supply circuit can be configured, the number of parts can be reduced, and an inexpensive plasma display device can be provided.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of a plasma display device according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a main configuration of a second-order raw converter circuit of FIG. 1;

FIG. 3 is a circuit diagram showing a configuration of a main part of a second-generation raw drive circuit of FIG. 2;

FIG. 4 is a circuit block diagram of a plasma display device according to a second embodiment of the present invention.

FIG. 5 is a circuit diagram showing a configuration of a main part of the second-order raw converter circuit of FIG. 4;

FIG. 6 is a circuit block diagram of a plasma display device according to a third embodiment of the present invention.

FIG. 7 is a circuit diagram showing a configuration of a main part of a partial second-generation converter circuit of FIG. 6;

8 is a circuit diagram showing a configuration of a main part of a partial second-generation raw drive circuit of FIG. 7;

FIG. 9 is a circuit block diagram of a plasma display device according to a fourth embodiment of the present invention.

FIG. 10 is a circuit diagram showing a configuration of a main part of the partial second-generation converter circuit of FIG. 9;

FIG. 11 is a schematic configuration diagram showing a panel structure of a plasma display.

FIG. 12 is a configuration diagram showing an example of electrode wiring of the panel.

FIG. 13 is a circuit block diagram of a conventional plasma display device.

[Explanation of symbols]

Reference Signs List 11 PDP panel 19 Commercial AC power supply 100, 400, 600, 900 Plasma display device 122 AC-DC power supply circuit 161 PDP drive circuit 162 Video processing circuit 611, 911 Partial second-generation converter circuit 1223 AC-DC converter circuit 1224, 411 2 Next-generation converter circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhiko Minno 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. (reference) 5C080 AA05 BB05 DD26 FF03 HH02 HH04 JJ02 JJ03 JJ06

Claims (9)

[Claims] 1. A PDP panel in which at least a pair of substrates whose front sides are transparent are opposed to each other so that a discharge space is formed between the substrates, and an electrode group is disposed on the substrates.
A display drive circuit unit for applying a signal to the P panel to perform display; and a power supply circuit unit for supplying a drive voltage to the display drive circuit unit. And a flyback type secondary converter circuit for stabilizing an output power supply voltage by regenerating the output power supply voltage on the side of the plasma display device. 2. The power supply circuit according to claim 1, wherein a plurality of AC-DC converter circuits are used, and at least one of the plurality of AC-DC converter circuits is a flyback type secondary converter circuit. Plasma display device. 3. The power supply voltage for driving the PDP panel, the power supply voltage for the video processing circuit, and the power supply voltage for the microcomputer are at least output from the second-generation converter circuit, and the power supply voltage for driving the PDP panel is regenerated. The plasma display device according to claim 1, wherein: 4. The plasma display device according to claim 1, wherein an output for a sustaining voltage of the PDP panel is regenerated. 5. A PDP panel in which at least a pair of substrates whose front sides are transparent are opposed to each other so that a discharge space is formed between the substrates, and an electrode group is disposed on the substrates.
A display drive circuit unit for applying a signal to the P panel to perform display, and a power supply circuit unit for supplying a drive voltage to the display drive circuit unit; That the output power supply voltage is stabilized by regenerating power to the primary side, and a flyback type partial secondary converter circuit that transfers energy to the secondary side by the normal flyback method under heavy load is provided. Characteristic plasma display device. 6. The power supply circuit according to claim 5, wherein a plurality of AC-DC converter circuits are used, and at least one of the plurality of AC-DC converter circuits is a flyback type partial second-generation converter circuit. The plasma display device according to the above. 7. The output of the partial 2nd-order raw converter circuit is:
The power supply voltage for driving a PDP panel, a power supply voltage for a video processing circuit, and a power supply voltage for a microcomputer, wherein the power supply voltage for driving the PDP panel is regenerated as a stabilized voltage. Plasma display device. 8. A power supply circuit section comprising a partial secondary power converter circuit and a flyback type AC-DC converter circuit, wherein a switching frequency of the partial secondary power converter circuit is switched by the AC-DC converter circuit. The plasma display device according to claim 5, wherein the frequency is lower than the frequency. 9. The plasma display device according to claim 5, wherein an output for a sustaining voltage of the PDP panel is regenerated.