KR100279045B1 - Brightness compensation method according to the increase in the number of pre-lipid pulses of PDP - Google Patents

Abstract

The present invention relates to a brightness compensation method according to an increase in the number of sustain discharge pulses of a PDP. The present invention relates to an increase in the number of sustain discharge pulses of a PDP that can compensate for a decrease in brightness over time by increasing the number of sustain pulses for a subfield. It relates to a brightness compensation method according to. The present invention provides a signal input unit for receiving a composite image signal, a luminance signal processor for processing and converting a luminance signal among the signals output from the signal input unit, a data processor for processing and converting a signal output from the signal input unit, and And a PDP driver for driving the PDP according to the output of the data processor, wherein the composite image signal inputted to the PDP is digitally converted by the luminance signal processor to be output to the sustain pulse controller; The order of the data is rearranged so that the composite video signal is processed by the data processing unit to match the arrangement of the data required for the PDP driving, and the data about the number of sustain pulses allocated to the subfields by the sustain pulse controller is PDP. Holding pulse control from the holding pulse input section in the holding pulse control section before being applied to the driving section. It presents a luminance compensation method according to the increased number of the sustain discharge pulses of the PDP that is the call number of the sustain pulse control, so that by including a process in which the input such that over time the reduction in the brightness compensation according to the.

Description

Brightness Compensation Method by Increased Number of Maintenance Discharge Pulses

The present invention relates to a brightness compensation method according to an increase in the number of sustain discharge pulses of a PDP. The present invention relates to an increase in the number of sustain discharge pulses of a PDP that can compensate for a decrease in brightness over time by increasing the number of sustain pulses for a subfield. A brightness compensation method in according to increase of number of sustain discharge 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 at a voltage higher than 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, there is a problem in that the screen is not clearly distinguished due to the decrease in brightness over time.

Accordingly, an object of the present invention is to invent the above problems, the object of the present invention is to provide an external input for the maintenance pulse when the brightness is reduced over time, the compensation of the brightness can be made It is to provide a brightness compensation method according to the increase in the number of sustain discharge pulses of the PDP.

The technical idea of the present invention for achieving the object of the present invention as described above is a signal input unit for receiving a composite image signal, a luminance signal processing unit for processing and converting the luminance signal from the signal output from the signal input unit, and the signal input unit A data processing unit for processing and converting a signal output from the PDP, and a PDP driving unit for driving the PDP according to the output of the data processing unit, wherein the composite image signal input to the PDP is converted into an average luminance level of the luminance signal by the luminance signal processing unit. The digital conversion is output to the sustain pulse control unit,

The order of the data is rearranged so that the composite video signal is processed by the data processing unit to conform to the arrangement of data required for the PDP driving, and the data for the number of sustain pulses allocated to the subfield by the sustain pulse controller is It is assumed that the number of sustain pulses is controlled so that the number of sustain pulses is controlled so that the decrease in brightness over time is compensated by including the process of inputting the sustain pulse control signal from the sustain pulse input unit in the sustain pulse control section before being applied to the PDP driver.

1 is a view for explaining a brightness compensation method according to the increase in the number of sustain discharge pulses of the PDP according to the present invention.

FIG. 2 is a block diagram illustrating a data processor of FIG. 1. FIG.

3 is a block diagram illustrating a sustain pulse controller of FIG. 1.

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

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

100: signal input unit 200: luminance signal processing unit

300: holding pulse control 301: holding pulse selective adding unit

302: sustain pulse input unit 303: ROM

400: data processor 401: video decoder

402: ADC unit 403: frame memory

404: data interface unit 500: PDP drive unit

501, 503: address driver IC 502: plasma panel driver IC

504: drive IC control unit 505: sustain and scan drive IC

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

1 is a block diagram illustrating a brightness compensation method according to an increase in the number of sustain discharge pulses of a PDP according to an embodiment of the present invention, and includes a signal input unit 100 receiving a composite video signal and a signal output from the signal input unit 100. A luminance signal processor 200 for processing and converting a luminance signal, a data processor 400 for processing and converting a signal output from the signal input unit 100, and a PDP is driven according to the output of the data processor 400. The PDP driving unit 500 is made.

Here, the luminance signal processing unit 200 is a Y / C separation unit (not shown) for detecting the luminance signal from the composite image signal input through the signal input unit 100, the average luminance level (APL) of the detected luminance signal And an AD circuit (not shown) for digitally converting the average luminance level, and the digital signal converted by the AD converter is applied to the sustain pulse controller (300). do.

The sustain pulse control unit 300 may include a sustain pulse select adder 301 that adjusts the number of sustain pulses based on a signal output from the luminance signal processor 200 and an input of a sustain pulse input unit 302 described later. The ROM 303 stores patterns of various sustain pulses.

In addition, as illustrated in FIG. 2, the data processor 400 includes a video decoder 401 for separating an image signal output from the signal input unit 100 into an RGB signal, and the video decoder 401. An ADC unit 402 for digitally converting the output RGB signal, and an RGB signal converted into a digital data signal through the ADC unit 402 are stored, and the data is continuously read and written alternately. A frame memory 403 connected to the frame memory 403 and a rear end of the frame memory 403, and outputting the data in order to match the arrangement of data required by the address driver ICs 501 and 503 in the PDP driver 500. The data interface 404 is made.

As shown in FIG. 4, the PDP driver 500 includes: a plasma panel 502 having a sustain electrode, a scan electrode, and an address electrode; a sustain for driving the sustain electrode and the scan electrode on the plasma panel 502; A driving IC controller 504 for controlling the sustain and scan driving ICs 505 according to scan pulses of the scan driver IC 505 and the sustain pulse controller 300, and an address electrode on the plasma panel 502. It consists of two address driving ICs 501 and 503 for driving.

Hereinafter, a brightness compensation method according to an increase in the number of sustain discharge pulses of a PDP according to the present invention will be described with reference to FIGS. 1, 2, 3, and 4.

First, in the composite image signal input to the signal input unit 100, the luminance signal is separated from the Y / C separation unit in the luminance signal processing unit 200, and the separated luminance signal corresponds to the average luminance level through the integration circuit unit. An APL is obtained, and the average luminance level signal is converted into a digital signal by the ADC unit and output to the sustain pulse select adder 301 in the sustain pulse control unit 300.

At this time, a sustain pulse input unit 302 is connected to the sustain pulse select adder 301, and the sustain pulse input unit 302 applies a control signal capable of adjusting the number of sustain pulses in the subfield.

Here, the holding pulse input unit 302 applies a holding pulse control signal by a user's external key or button (not shown) to the holding pulse selection adding unit 301, for example, the brightness of the screen to a certain degree. When is decreased, the number of sustain pulses applied to each subfield is increased by a certain number so that the reduced brightness is compensated for.

Accordingly, the sustain pulse select adder 301 is based on the input signals of the ADC unit 402 and the sustain pulse input unit 302, and according to the pattern of the sustain pulse stored in the ROM 303, each subfield. The number of sustain pulses applied by the sustain and scan driver ICs 505 is controlled by applying data about the number of sustain pulses allocated to the driver IC controller 504.

As described above, the present invention provides a signal input unit for receiving a composite video signal, a luminance signal processor for processing and converting a luminance signal among signals output from the signal input unit, and a signal output unit for processing and converting a signal output from the signal input unit. And a PDP driver for driving the PDP according to the output of the data processor, wherein the composite image signal inputted to the PDP is digitally converted by the luminance signal processor to output the average luminance level of the luminance signal to the sustain pulse controller. And rearranging the data order so that the composite video signal is processed by the data processing unit to conform to the arrangement of data required for the PDP driving, and the number of sustain pulses allocated to the subfield by the sustain pulse controller. Before the data for is applied to the PDP driving section, the holding pulse input in the holding pulse control section By including a process of inputting the sustain pulse control signal from the output unit, the number of sustain pulses is controlled to compensate for the decrease in brightness over time.

Claims (2)

In the method to compensate for the decrease in brightness by controlling the number of sustain discharge pulses of the subfield, The composite image signal input to the PDP is digitally converted by the luminance signal processing unit 200 to the average luminance level of the luminance signal and output to the sustain pulse controller 300; A process of rearranging the order of the data such that the composite video signal is processed by the data processing unit 400 to match the arrangement of data required for driving the PDP; and And a process of applying data on the number of sustain pulses from the sustain pulse controller (300). The sustain pulse control signal is input from the sustain pulse input unit 302 before the data regarding the number of sustain pulses allocated to the subfield by the sustain pulse control unit 300 is applied to the PDP driver 500. Brightness compensation method according to the increase in the number of sustain discharge pulses of the PDP, characterized in that the process includes.