JP3298926B2 - Display panel drive control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display panel drive control device for controlling drive display of a display panel, and more particularly to a display panel drive control device having a simplified circuit structure.

[0002]

2. Description of the Related Art Generally, a flat panel display unit is of a self-luminous type and is indirect discharge plasma display (AC.
PDP) or direct discharge plasma display (DC / P)
DP). In these self-luminous display units, the power consumption increases as the number of light emitting cells among the display cells increases. The ratio of the number of light-emitting cells used for display to the total number of cells and emitting light is called a display ratio. Automatic output control (APC) is used to reduce apparently the power consumption when the display ratio increases. ;
Automatic Power Control) circuit. This APC circuit reduces the light emission intensity by reducing the driving frequency of the panel or restricting the driving current or driving voltage of the cell when the display rate increases, thereby equivalently reducing the power consumption. is there. Note that even if the light emission intensity is reduced when the display ratio increases, there is no difference from the total light emission luminance when the display ratio is low.

FIG. 6 shows a conventional display panel drive control device.
There were the following. In the figure, a display panel drive control device outputs a drive voltage V _S from a power supply circuit 10 to a display unit 20 and a plasma display (PDP) of the display unit 20 based on a display control signal output from the control unit 3. 28 is driven.

The power supply circuit 10 receives a direct current through a rectifier circuit 11 or directly and receives a DC current based on control of a pulse width modulation circuit 18 driven by signals from a feedback circuit 15 and an error voltage amplifier 16. The DC current input to the AC inverter 12 is output as an AC current having a predetermined pulse width, and the rectifier circuit 13 and the smoothing circuit 14 output the DC current _IS having a predetermined current value as the drive voltage V _S by the rectifier circuit 13 and the smoothing circuit 14.

The display unit 20 has an APC circuit 21 for generating and outputting an APC signal for controlling the driving frequency of the PDP 28 based on the driving voltage V _S , and the APC signal and the display control signal output from the control unit 3. Drive control of the PDP 28 based on the

[0006]

Since the conventional display panel drive control device is constructed as described above, it is necessary to provide an APC circuit in the display unit. DC current I
_{In addition} to detecting the current value of _S , an APC signal must be generated, and there is a problem that the APC circuit, particularly the display unit 20, becomes large and the circuit configuration becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to propose a display panel drive control device capable of miniaturizing and simplifying the entire device.

[0008]

According to a first aspect of the present invention, there is provided a display unit for controlling display by driving a display panel on which a plurality of cells are arranged by a drive control circuit; A display panel drive control device including a power supply circuit for supplying a DC drive voltage, wherein a power control signal for controlling power consumption of the display panel is generated using a control signal for performing a control operation of the power supply circuit. The power control signal is input to a drive control circuit of the display unit to control power consumption of the display panel. The invention according to claim 2 is the display panel drive control device according to claim 1, wherein the power supply circuit includes:
A stabilizing circuit for stabilizing the DC output voltage, wherein the stabilizing circuit compares the DC output voltage with a reference voltage having a predetermined value to determine an error voltage, and adjusts the magnitude of the error voltage. A power control signal for controlling the power consumption of the display panel in accordance with the magnitude of the error voltage, and generating a power control signal for controlling the power consumption of the display unit. To control the power consumption of the display panel. According to a third aspect of the present invention, in the display panel drive control device according to the first aspect, the power supply circuit has a control signal for controlling an output current of the power supply circuit, and uses the control signal. Then, a power control signal for controlling power consumption of the display panel is generated, and the power control signal is input to a drive control circuit of the display unit to control power consumption of the display panel. According to a fourth aspect of the present invention, in the display panel drive control device according to the first aspect, the power supply circuit includes at least one of a drive frequency, a drive current, and a drive voltage of the display panel based on the control signal. Is output to the display unit.

[0009]

According to the present invention , a power control signal for controlling power consumption of a display panel is generated in a power supply circuit by using a control signal for controlling the power supply circuit. Then, the power control signal is input to a drive control circuit of the display unit to control power consumption of the display panel. Therefore, since the signal for controlling the power consumption of the display panel is generated by using the signal of the control circuit provided in the stabilized power supply circuit, the entire device is compared with the conventional configuration in which the control signal is generated in the display unit. Can be downsized and the circuit configuration can be simplified.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 is an overall block diagram of the apparatus of this embodiment, and FIG.
FIG. 3 is an APC signal generation timing chart for each display rate (small, medium, large).

In each of the drawings, the display panel drive control device according to the present embodiment stabilizes the voltage value and sets the drive voltage V _S
And a control unit 3 for outputting an APC signal based on a voltage control signal for controlling the driving voltage V _S , a display control signal corresponding to the display content, and the driving voltage V _S , The display unit 2 is configured to drive and control the PDP 28 based on the APC signal and the display control signal to perform light emission display.

The power supply circuit 1 comprises a DC-AC inverter 1
2, a drive output via the rectifier circuit 13 and the smoothing circuit 14.
Dynamic voltage V_SIs attenuated to a predetermined value and the feedback voltage V_SAs ´
The output feedback circuit 15 and the feedback voltage V_S´ and reference
Reference voltage V output from voltage output unit 17_ref1And compare
Error voltage (hereinafter, modulation signal) V_mOutput error voltage
The amplifier 16 and the modulated signal V_mPulse width variation based on
Output a pulse width signal to the DC-AC inverter 12
The pulse width modulation circuit 18 and the modulation signal V _mBased on
And an APC generator 19 for outputting an APC signal.
Configuration. The APC generation unit 19 outputs the reference voltage V_ref2
And a reference voltage output unit 19a that outputs
_ref2And the modulation signal V_mAPC voltage V_APC
And the APC voltage V
_APCAPC signal is generated based on the
And an output APC signal generation circuit 19c.
You.

Next, the operation of the apparatus according to this embodiment based on the above configuration will be described.
The work will be described. First, from DC current or AC power supply
DC-AC inverter 12 rectifies the output voltage
13 and the smoothing circuit 14 stabilize the drive voltage V_SWhen
And outputs it to the display unit 2, and the feedback circuit 15,
Via error voltage amplifier 16 and pulse width modulation circuit 18
The drive voltage V_SFeedback control. This file
The pulse width modulation circuit 18 switches the feedback control.
A pulse that acts as a recuperator and is based on pulse width control
Output to the DC-AC inverter 12.
By controlling the drive pulse width of the C-AC inverter 12,
Now. That is, the driving voltage V _SOutput current I_SIncreased
Dynamic voltage V_SWhen the pulse width decreases, the pulse width modulation circuit 18
DC-AC inverter 1
2 to drive the DC-AC inverter 12 for a long time.
Drive voltage V_STo compensate for the voltage drop
To stabilize.

[0014] Modulation signal V _m output from the error voltage amplifier 16 is input to the APC generation unit 19, the APC
Generating unit 19 outputs the APC voltage V _APC compares the reference voltage V _ref2 outputted from the modulation signal V _m and the reference voltage output unit 19a in the comparator 19b, the APC voltage V
_{The APC} signal generation circuit 19c outputs an APC signal, which is a pulse signal having a predetermined pulse duty, to the display unit 2 based on the APC.

The display unit 2 controls the light emission by driving the PDP 28 based on the input APC signal. Further, the light emission amount control of the PDP 28 will be described based on the timing charts of FIGS. When the PDP 28 of the display unit 2 performs light emission display at the highest driving frequency, the XY composite waveform is set to 50 KHz as shown in FIG. 2A, and one cycle is 20 μsec. Flash twice. When the PDP 28 is to emit light at the lowest driving frequency, as shown in FIG.
It is set to z, and light emission is performed twice during this 100 μsec because one cycle is 100 μsec.

As shown in FIG. 3, two types of light emission modes as shown in FIGS. 2A and 2B are used at 60 Hz (period 16.6 m).
By appropriately combining with the repetition frequency of (sec) or more, it is possible to arbitrarily control the apparent driving light emission frequency to a small, medium, or large value to perform light emission display.

Here, the number of lighting cells is reduced by the display data signal from the control unit 3, and when the display ratio becomes the "minimum" state, the driving power supplied from the power supply circuit 1 to the display unit is reduced. As a result, the transition to the voltage V _S is higher, the feedback circuit 15, the modulation signal V _m to be output through the error voltage amplifier 16 is minimized as compared to a reference voltage V _ref2, the output voltage V _APC comparator 19b Is the lowest level. In response to this, the output of the APC signal generation circuit 19C becomes “H” level and is input to the timing control circuit 24 of the display unit 2. Thus, the timing control circuit 24 controls the panel 28 to be driven at the highest frequency of 50 KHz in FIG.

Next, when the display data signal from the control unit 3 causes the number of lighting cells to increase and the display ratio to be in the "medium" state, the driving power supplied from the power supply circuit 1 to the display unit increases, and the voltage V _S Is an average value. As a result, since the output voltage V _APC of the modulating signal V _m becomes substantially equal to the reference voltage V _ref2 comparator 19b becomes the average value,
As shown in FIG. 3, the output of the APC signal generation circuit 19C has a waveform in which the “H” level and the “L” level repeat at substantially equal intervals, and are input to the timing control circuit 24. Accordingly, the timing control circuit 24 controls the panel 28 to be alternately driven at both the frequency of 50 KHz in FIG. 2A and the frequency of 10 KHz in FIG. 2B. The light emission operation is performed at this frequency.

Furthermore, the display data signal from the control unit 3, when the display ratio number of lit cells increases becomes "large" state, the voltage V _S driving power is maximized is the minimum value.
As a result, the modulation signal V _m is the maximum as compared to the reference voltage V _ref2, since the comparator 19b and the output voltage V _APC also becomes maximum, the output of the APC signal generating circuit 19C, as shown in FIG. 3 "H" The repetitive waveform having the minimum level duty ratio is input to the timing control circuit 24.
As a result, the timing control circuit 24
As compared with the duty ratio of the 50 KHz drive shown in FIG.
Since the duty ratio of the 10 KHz drive shown in FIG. 4B is higher and the drive of the panel 28 is controlled, equivalently, 1
The light emission operation is performed at the lowest frequency near 0 KHz.

In the above embodiment, the power supply circuit
Signal of Error Voltage Amplifier Forming Constant Voltage Control Circuit
V_mAPC signal is generated and output based on
Is the voltage V in the overcurrent control circuit 4 as shown in FIG.
_SCAPC signal can be generated based on
Wear. In FIG. 4, in the other embodiment apparatus,
The overcurrent protection circuit 4 in the power supply circuit 1
Current detection resistor R in path 4 _SCVoltage obtained from_SCBased on
Reference voltage V output from voltage output unit 41_ref3And compa
The overcurrent protection signal V_OCThe stabilization control
Output to the circuit. The voltage V_SCEnters the APC generator 19
The comparator 19b,
Output from the power supply circuit 1 by the APC signal generation circuit 19c.
Output current I_SIs generated, and an APC signal corresponding to
Output to the display unit 2.

Further, in the above each embodiment, a configuration for generating an APC signal by using an error voltage (modulation signal) V _m or voltage V _SC for generating the constant voltage control circuit or overcurrent control circuit, Switching regulator D
The pulse width signal driving the C-AC inverter may be used as it is, or an APC signal may be generated based on a signal obtained by partially modifying the pulse width signal.

Further, as a circuit configuration for detecting the current I _S , a switching current in a switching transistor in a DC-AC inverter can be detected, and an APC signal can be generated based on the detected switching current.

In addition to the configuration for generating and outputting the APC signal by utilizing a part of the control circuit as described above, the power supply circuit 1 has a proportionality which is directly proportional to the drive voltage V _S as shown in FIG. An APC signal may be generated based on the voltage _VS2 , and the APC signal may be output to the display unit 2. In FIG. 5, a power supply circuit 1 according to another embodiment detects a rectifier circuit 13 by using a secondary winding for output power detection forming a transformer of a DC-AC inverter 12.
And outputs a proportional voltage V _S2 via the smoothing circuit 14 ′.
Based on this proportional voltage V _S2 , the APC generator 19
Generate a signal. The power line transformer by the driving voltage V _S of the DC-AC inverter 12 is applied and is
Since the proportional voltage V _S2 can be detected at an arbitrary voltage level proportional to the drive voltage V _S in an electrically insulated state, an APC signal suitable for the control signal level can be generated.

Further, in each of the above embodiments, the AP
Although the C signal is shown as a pulse by pulse width control (PWM), it may be generated as an analog signal such as a voltage amplitude.

[0025]

As described above, according to the present invention ,
In the power supply circuit, a power control signal for controlling power consumption of the display panel is generated using a control signal for controlling the power supply circuit, and the power control signal is input to a drive control circuit of the display unit. To control the power consumption of the display panel, so that the signal for controlling the power consumption of the display panel is generated by using the signal of the control circuit provided in the stabilized power supply circuit. The whole device can be downsized and the circuit configuration can be simplified as compared with the configuration in which control signals are generated in the display unit.

[Brief description of the drawings]

FIG. 1 is an overall block configuration diagram of a display panel drive control device according to an embodiment of the present invention.

FIG. 2 is a light emission timing chart at each drive frequency in the embodiment shown in FIG.

FIG. 3 shows each display rate (small, medium,
4 is an APC signal generation timing chart of FIG.

FIG. 4 is a block diagram of a main part of a drive control device for a display panel according to another embodiment of the present invention.

FIG. 5 is an overall block configuration diagram of a display panel drive control device according to another embodiment of the present invention.

FIG. 6 is an overall block configuration diagram of a conventional display panel drive control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Power supply circuit 2 ... Display unit 3 ... Control unit 4 ... Overcurrent protection circuit 11 ... Current circuit 12 ... DC-AC inverter 13 ... Rectifier circuit 14 ... Flat spine circuit 15 ... Feedback circuit 16 ... Error voltage amplifier 17, 19a, 41: Reference voltage output unit 18: Pulse width modulation circuit 19: APC generation unit

Continuation of front page (56) References JP-A-62-75588 (JP, A) JP-A-56-119191 (JP, A) JP-A-1-193797 (JP, A) JP-A-5-181430 (JP) JP-A-5-265391 (JP, A) JP-A-1-144364 (JP, A) JP-A-57-136229 (JP, A) JP-A-63-87178 (JP, A) 1-1107660 (JP, A) Fully open 1984-59,995 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G09G 3/28 G09G 3/20 611

Claims (4)

(57) [Claims] 1. A display panel drive control device comprising: a display unit for controlling display by driving a display panel on which a plurality of cells are arranged by a drive control circuit; and a power supply circuit for supplying a DC drive voltage to the display unit. A power control signal for controlling power consumption of the display panel is generated by using a control signal for performing a control operation of the power supply circuit, and the power control signal is input to a drive control circuit of the display unit. And a display panel drive control device for controlling power consumption of the display panel. 2. The display panel drive control device according to claim 1, wherein the power supply circuit has a stabilizing circuit for stabilizing the DC output voltage, and the stabilizing circuit includes a DC output terminal. A voltage is compared with a reference voltage of a predetermined value to obtain an error voltage, and the DC output voltage is stabilized based on the magnitude of the error voltage, and the power consumption of the display panel is changed according to the magnitude of the error voltage. Generating a power control signal for controlling the
A display panel drive control device, wherein the power control signal is input to a drive control circuit of the display unit to control power consumption of a display panel. 3. The display panel drive control device according to claim 1, wherein the power supply circuit has a control signal for controlling an output current of the power supply circuit, and the display is performed using the control signal. Generate a power control signal to control the power consumption of the panel,
A display panel drive control device, wherein the power control signal is input to a drive control circuit of the display unit to control power consumption of a display panel. 4. The display panel drive control device according to claim 1, wherein the power supply circuit controls at least one of a drive frequency, a drive current, and a drive voltage of the display panel based on the control signal. A display panel drive control circuit for outputting a control signal to a display unit.