KR100279044B1 - PDP Holding Pulse Control Device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a holding pulse control apparatus for a PDP, and more particularly, to a holding pulse control apparatus for a PDP that prevents the generation of overcurrent by controlling the number of holding pulses according to the state of a screen and makes the screen clear. The present invention obtains an average luminance level by separating a luminance signal from a composite video signal input through a signal input unit, and then digitally converts it into a sustain pulse control unit and detects current from a power supply unit supplying power to the system. After the digital conversion is input to the holding pulse control unit, the holding pulse control unit increases and decreases the number of holding pulses according to the state of the screen based on the two inputs. The present invention proposes a control pulse control device of the PDP that prevents the lifespan of the panel from being shortened due to occurrence and to make the identification according to the brightness of the screen clear.

Description

PD pulse holding device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling a sustaining pulse of a PDP, and to controlling the number of sustaining pulses according to the state of a screen, to prevent the occurrence of overcurrent and to clearly distinguish the screen. pulse for PDP).

In general, the PDP uses a matrix driving method that uses a strong nonlinearity characteristic of gas discharge, unlike the image display method adopted by the TV. Here, the nonlinearity is a feature of gas discharge, and since the gas discharge phenomenon is caused by ionization through the ionization process of the gas, the discharge occurs only when a voltage is applied above the discharge voltage at which the ionization reaction can sufficiently occur. The voltage refers to a characteristic of gas discharge in which no discharge occurs.

In addition, the PDP is generally driven by a continuous pulse having a constant voltage, the gray scale display is implemented by a digital method rather than an analog method, and because a relatively high voltage of several hundred volts is usually required during gas discharge, an image signal is generated. Amplify and drive.

The driving operation of the PDP can be roughly classified into three types: a selection operation, a holding operation, and an erasing operation. The selection operation is a driving operation necessary for initial discharge formation, and He + is generally used in the PDP. In the case of Xe, Ne + Xe, the penning mixture gas has a potential of 240V to 280V. In the case of the AC type PDP, the third electrode is introduced to reduce the high current caused by the sustain electrode and the parasitic capacitor caused by the dielectric in the surface discharge form, and adopts a driving method that separates the selection operation from the sustain operation. .

In addition, the holding operation is a driving operation in which discharge is maintained by a holding pulse having a lower voltage than a selection pulse by using the storage function characteristic of gas discharge. In the case of the AC type PDP, the storage function is effected by wall charge. By employing the memory driving method that can separate the selection operation and the holding operation, it is possible to operate without deterioration of luminance even when high gradation display for realizing a high quality display element is required.

Here, in the case of the AC PDP, the discharge is formed at a low voltage in a period of neutralizing the wall charge so that the wall charge is not sufficiently formed, or an erase pulse having a short pulse width is applied to prevent the wall charge from reaching a steady state. To remove the wall charges.

Hereinafter, the driving method for the gradation processing of the PDP as described above is as follows.

First, one field (60 Hz) is divided into several subfields (64 gradations: 6 subfields, 256 gradations: 8 subfields), and image data corresponding to each subfield is transferred to the plasma panel line by line through the address driver IC. The number of discharge sustaining pulses is reduced in order from the subfield to which the MSB data is written and the LSB subfield, and the gradation process is performed in the total discharge sustain period according to the combination thereof.

In addition, the driving order of all subfields is to repeat the operations of writing and erasing all screens, writing data, and maintaining discharge (screen display) .In the period of neutralizing the wall charge in the case of AC PDP, the operation mode for discharge erasing is first performed. The discharge is formed at a low voltage so that the wall charge is not sufficiently formed, or an erase pulse having a short pulse width is applied to prevent the wall charge from reaching a steady state, thereby removing the wall charge, that is, after maintaining the discharge of the previous subfield. To erase the wall charges remaining in the selected (discharged) pixels, write the wall charges to all pixels for a short period of time invisible, and then erase all the remaining wall charges by erasing all the pixels to erase the PDP. There is a whole screen erase process to initialize.

In the case of the He + Xe and Ne + Xe penning mixtures generally used in the PDP, a potential of 240 V to 280 V is applied. In the case of an AC type PDP, a third electrode is introduced to maintain a surface discharge. The high current caused by the parasitic capacitor by the electrode and the dielectric is reduced, and the driving method that separates the selection operation from the holding operation is adopted. In the practical application, a selection operation is performed in which the wall pulses are selectively formed on the pixel to be discharged by writing the corresponding data line by line through the data writing electrode while shifting the scanning pulse sequentially (1 to 480) to the line scanning electrode. In addition, a data writing and scanning process, which is a driving operation required for initial discharge formation, is followed.

In addition, a sustain pulse is alternately applied between the discharge sustain driver electrode and the line scan electrode to start and sustain the discharge of the pixel on which the wall charge is formed, and at this time, the unwritten pixel is influenced by the peripheral pixel to which it is written, Since there is a possibility of causing an error discharge, a discharge maintenance process is performed in which a small erase is performed every time the sustain pulse is applied to ensure accurate discharge.

However, when the sustain pulse is applied in the above-described manner, the number of sustain pulses increases in the subfield in the case of a bright screen with high brightness, and eventually an overcurrent occurs. This shortens the problem.

Accordingly, an object of the present invention is to invent the above problems, when the bright screen lasts more than a certain time to reduce the number of holding pulses to prevent the occurrence of overcurrent, too dark screen over a certain time The present invention provides a control pulse control apparatus for a PDP that increases the number of sustain pulses to enable identification of a screen.

The technical idea of the present invention for achieving the object of the present invention as described above is a power supply means for supplying the power required for driving the PDP, current detection and conversion means for detecting and converting the current supplied from the power supply means; Luminance signal processing means for processing and converting a luminance signal from among the composite image signals input for adjusting the sustain pulse applied to the PDP;

By providing a holding pulse control apparatus for a PDP comprising a holding pulse control means for controlling the number of holding pulses based on the output of the current detecting and converting means and the luminance signal processing means, the current detecting and converting means is a power supply means. When the current supplied from the signal increases, the current value is detected, converted into a digital signal, and applied to the sustain pulse control means, and the sustain pulse control means is separated from the luminance signal processing means and the current detection and conversion means. On the basis of the two digital data signals inputted, if the excessive current of a certain degree or more is supplied so that a bright screen is maintained, the number of sustain pulses supplied is reduced.

1 is a block diagram showing an apparatus for controlling a sustain pulse of a PDP according to the present invention.

FIG. 2 is a block diagram illustrating the luminance signal processor of FIG. 1. FIG.

3 is a block diagram illustrating a PDP driver of FIG. 1.

<Description of the symbols for the main parts of the drawings>

100: power supply unit 200: current detection and conversion unit

300: PDP driver 301: sustain and scan driver IC

302: driving IC control unit 303, 305: address driving IC

304: plasma panel 400: signal input unit

500: luminance signal processing unit 600: holding pulse control unit

601: Y / C separation unit 602: Integrating circuit unit

603: AD converter 700: ROM

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram illustrating an apparatus for controlling a sustaining pulse of a PDP according to the present invention, wherein a power supply unit 100 for supplying power for driving a PDP and a current supplied from the power supply unit 100 are detected and converted. A current detecting and converting unit 200, a signal input unit 400 for receiving a composite video signal, a luminance signal processing unit 500 for processing and converting a luminance signal among the signals output from the signal input unit 400,

A sustain pulse controller 600 for controlling the number of sustain pulses based on the outputs of the current detection and conversion unit 200 and the luminance signal processor 500, a ROM 700 for storing various sustain pulse patterns, and the power supply In addition to being supplied with power from the supply unit 100, the PDP driving unit 300 is driven according to the control of the number of sustain pulses of the sustain pulse controller 600.

As shown in FIG. 2, the luminance signal processing unit 500 includes a Y / C separation unit 601 for detecting a luminance signal among the composite image signals input through the signal input unit 400. An integrated circuit unit 602 for detecting an average luminance level APL of the luminance signal and an AD converter 603 for digitally converting the average luminance level, and the digital signal converted by the AD converter 603. Is applied to the sustain pulse control unit 600.

In addition, the PDP driving unit 300 receives power from the plasma panel 304 and the power supply unit 100 in which the sustain electrode, the scan electrode, and the address electrode are formed, as described in FIG. A sustain and scan driver IC 301 for driving the sustain electrode and the scan electrode on the plasma panel 304 and two address driver ICs for driving the address electrode on the plasma panel 304 under the control of the IC controller 302. 303 and 305 and a drive IC controller 302 for controlling the sustain and scan drive ICs 301 according to the sustain pulse control of the sustain pulse control unit 600.

Hereinafter, with reference to the accompanying Figures 1, 2 and 3 will be described the operation of the holding pulse control apparatus of the PDP according to the present invention.

First, the image signal input through the signal input unit 400 is obtained through the luminance signal processing unit 500 to obtain a normal luminance level of the luminance signal, and then digitally converted and applied to the sustain pulse controller 600. The PDP driver 300 is connected between the power supply unit 10 for supplying power to the sustain and scan driver ICs 301 in the PDP driver 300 and the PDP driver 300. When the current to be increased), the current value is detected.

In addition, the current detection and conversion unit 200 converts the detected current value into a digital signal and applies it to the sustain pulse control unit 600.

Therefore, the sustain pulse control unit 600 is based on two digital data signals input from the luminance signal processing unit 500 and the current detection and conversion unit 200, so that excessive current is supplied to a predetermined level or more and the screen is too bright. If this persists, the number of sustain pulses supplied to the plasma panel 304 in the PDP driver 300 is reduced.

That is, the sustain pulse controller 600 stores the number of sustain pulses in the ROM 700 based on two digital data signals input from the luminance signal processor 500 and the current detection and conversion unit 200. Thereafter, the data corresponding to the optimum number of sustain pulses among the sustain pulse patterns stored in the ROM 700 is output to the driver IC controller 302 in the PDP driver 300.

Therefore, the driving IC controller 302 adjusts the number of sustain pulses applied to the plasma panel 304 based on the data on the number of sustain pulses inputted, so that the brightness of the screen that is too bright due to excessive current is supplied. Can be controlled.

As described above, the present invention separates the luminance signal from the composite video signal input through the signal input unit, obtains an average luminance level, inputs it to the sustain pulse selection adding unit, and converts the digital signal into a power supply for supplying power to the system. After detecting the current from the supply unit, it is digitally converted and input to the sustain pulse control unit. The sustain pulse control unit increases and decreases the number of sustain pulses according to the state of the screen based on the two inputs. When the number is large, there is an effect of preventing the life of the panel from being shortened due to the generation of excessive current, and an effect of efficiently identifying the brightness of the screen.

Claims (3)

In the PDP holding pulse control apparatus which can control the brightness of the screen by adjusting the number of holding pulses, Power supply means for supplying power to the PDP drive; Current detecting and converting means for detecting and converting a current supplied from the power supply means; Luminance signal processing means for processing and converting a luminance signal from among the composite image signals input for adjusting the sustain pulse applied to the PDP; and And a sustain pulse control means for controlling the number of sustain pulses based on the output of the current detection and conversion means and the luminance signal processing means. The holding pulse control apparatus of claim 1, wherein the current detecting and converting means detects and converts an excessive current from the power supply means into a digital signal. The method according to claim 1, wherein the holding pulse selection adding means stores the number of holding pulses in the ROM 700 based on two digital data signals inputted from current detecting and converting means and luminance signal processing means, and then stores the ROM. The sustain pulse control of the PDP, characterized in that the number of sustain pulses is reduced in a screen that is too bright by outputting data corresponding to the optimal number of sustain pulses among the sustain pulse patterns stored in advance in the 700. Device.