KR19990053561A - Power on / off method of PDTV - Google Patents

Abstract

The present invention relates to a power on / off operation of a PDTV system. In particular, the high voltage driving circuit unit and the logic power unit are independently signal-processed at the time of power on / off switching to safely turn on or off the PD system. In the power on / off operation of the conventional PDTV system, one port is set in the microcomputer so that the power on / off of the logic power unit and the high voltage driving circuit unit are operated at the same time. There was a problem that the circuit portion is destroyed. Accordingly, in the present invention, the power control port is divided into a high voltage driving circuit unit and a logic power unit in the microcomputer, and when the power is switched on, the logic power unit is turned on first, and when the logic power unit operates normally after a certain time, the high voltage driving circuit unit is switched on. On the contrary, the present invention proposes a power on / off method for a PDTV television that can be safely turned off by switching off the power of the high voltage driving circuit part first and then switching off the power of the logic power part.

Description

Power on / off method of PDTV

The present invention relates to the power on / off of the PDTV system, and in particular, the power control port of the microcomputer is divided into a high voltage driving circuit part and a logic power part. When the power unit is in normal operation, the power supply of the high voltage driving circuit unit is switched on. On the contrary, when the power supply is switched off, the PD is switched off first, and the power of the logic power unit is turned off so that the power can be safely turned off. The present invention relates to a power on / off method of a television.

PD is generally driven by a continuous pulse with a constant voltage, and gradation display is implemented by digital rather than analog. However, since gas discharge usually requires a relatively high voltage of several hundred volts, the video signal is amplified and driven. The reason why the PD is suitable for the enlargement is that not only the process but also the characteristics useful for the enlargement of the gas discharge can be applied to the driving method.

PDP's driving technology concept is as follows. PD is an active light emitting display device in which ultraviolet rays generated from gas discharge excite a fluorescent film to realize an image. In other words, since the PDP uses ultraviolet light emission by gas discharge as a light source corresponding to each pixel, the driving circuit simply functions to form or erase gas discharge for each pixel in order to implement a display image. The driving circuit includes an image signal and signal control unit for each pixel constituting an image, and a high speed high voltage switching control unit that can form or eliminate ultraviolet rays generated from each pixel. The driving operation of such a PDTV system can be classified into three types: selection operation, holding operation and erasing operation.

The selection operation is a driving operation necessary for initial discharge formation. In the case of Pen + mixture of He + Xe and Ne + Xe which are generally used in PD P, apply potential of 240V ~ 280V. In the case of AC, the third electrode is introduced to reduce the high current caused by the sustain electrode in the surface discharge form and the parasitic capacitor caused by the dielectric, and adopts a driving method that separates the selection operation from the sustain operation.

The holding operation is a driving operation in which discharge is maintained by a holding pulse having a lower voltage than the selection pulse by using the storage function characteristic of gas discharge. In the case of the AC type PD, the memory function effect by the wall charge and the DC type PD have the self-priming effect. In the case of the memory driving method which can separate the selection operation and the holding operation by using the memory function, the PDP can operate without losing the luminance even for a large display device in the case of high gradation display for realizing a high quality display device. It provides a driving method.

The erasing operation is an operation mode for discharging the discharge. In the case of a DC type PD, the voltage is lowered to a voltage lower than the discharge sustain voltage. The wall charges are removed by preventing them from being formed or by applying an erase pulse having a short pulse width to prevent the wall charges from reaching a steady state.

1 is a pulse wave for power on / off of a conventional PD system. The power is switched on at the low signal 10 and the power is switched off at the high signal 20. Therefore, conventionally, one port is set from the microcomputer to turn on and off the power, and the high voltage driving circuit portion and the logic power portion are operated at the same time.

Therefore, there is a problem in that the unknown state value in the logic power unit is input to the high voltage driving circuit unit and the high voltage driving circuit unit is destroyed.

Accordingly, an object of the present invention is to solve the above problems, and in particular, an object of the present invention is to independently signal-process a high voltage driving circuit unit and a logic power unit during power on / off switching in a PD television to safely turn on or off the PD system. To do that.

In addition, the technical idea of the present invention for achieving the above object is to divide the power control port into a high-voltage driving circuit and a logic power unit in the microcomputer, the logic power unit is first turned on when the power is switched on, and the logic power unit operates normally after a certain period of time. On the other hand, the high voltage driving circuit unit turns on and off the power. On the contrary, when switching off the power supply, the power supply of the PDTV television is turned off safely by first switching off the power supply of the high voltage driving circuit and then switching off the logic power unit. To provide a method.

1 is a waveform diagram of the power on / off of the conventional PD system

2 is an overall block diagram of a PDTV system

3 is a waveform diagram of the power on / off of the PDTV according to the present invention;

<Code Description of Main Parts of Drawing>

1: AV unit 2: ADC unit

3: memory section 4: data interface section

5: timing controller 6: address driver IC

7: Hold / Scan drive IC 8: High voltage drive circuit

9: logic power unit 10: microcomputer

80: composite video signal processor 90: digital data processor

100: PD drive part

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 2 is a block diagram for explaining the overall operation of the PDTV system.

The PDP-TV generally includes a composite video signal processing unit 80 composed of an AV unit 1 which analog-processes a composite video signal received through an antenna and provides the ADC unit with a digital signal by sampling the input analog composite video signal. The ADC unit 2 for processing data, the memory unit 3 for rearranging the digital image data input from the composite image signal processing unit 80, and the rearranged digital image data are received and are suitable for PDG gray level processing. A digital data processing unit 90 comprising a data interface unit 4 for making a data stream, a timing controller unit 5 for generating and supplying a main clock for controlling the memory unit 3 and the entire system; And a sustain / address driver IC 6 which receives a data stream from the data interface unit 4 and supplies data to the plasma panel for gradation processing. It consists of the PD drive part 100 which consists of the scan drive IC7.

The AV unit 1 receives an NTSC composite signal, separates the analog R, G, and B signals from the horizontal and vertical synchronization signals, obtains an APL (Average Picture Level) corresponding to the average value of the luminance signal Y, and then converts the ADC unit ( Supply to 2). This APL is used to improve the brightness of the PDTV system. NTSC composite video signal is interlaced scanning method, and one frame is composed of two fields of Odd / Even, horizontal synchronous signal is about 15.73KHZ, and vertical synchronous signal is about 60Hz. The audio signal separated from the composite video signal is output through the audio amplifier directly to the speaker. The ADC unit 2 receives analog R, G, and B signals as inputs, converts them into digital data, and outputs them to the memory unit 3. At this time, the digital data is converted into images for improving the brightness of the PDTV system. Data. The ADC section 2 is divided into an amplifier section, a clock generation section, a sampling area setting section, and a data mapping section. The amplifying section in the ADC section 2 amplifies the analog R, G, B, and APL signals to a signal level suitable for quantizing, and converts the horizontal and vertical synchronization signals into a constant phase and outputs them. The clock generator must use a clock that is synchronized with the input synchronization signal. To this end, the clock generator generates clocks using phase locked loops (PLLs). PLL is controlled by PD (Phase Detector), VCXO (Voltage Controlled Crystal Oscillator), LF (Loop Filter), which controls the phase of input synchronous signal and the phase of variable pulse output from Loop. It consists of a VCXO that oscillates and a PC (Programmable Counter) that outputs a phase comparison pulse by dividing the output of the VCXO, and outputs a clock synchronized with the input synchronous signal. If the clock synchronized to the input synchronization signal is not used, the vertical linearity of the displayed image is not guaranteed. In addition, the sampling area is set to a vertical position and a horizontal position. The vertical position section is a pulse for setting only the line with the image information among the input signals, and the horizontal position section is a pulse for setting only the time with the image information among the lines set to the vertical position. The vertical position section and the horizontal position section are the standards for sampling. At this time, a total of 480 lines are selected, each with 240 lines in the Odd / Even field. The horizontal position section should be such that there can be at least 853 sampling clocks per selected line. The data mapping unit of the ADC unit 2 maps the R, G, and B data output from the A / D converter into data corresponding to the brightness characteristics of the PDP. In other words, by arranging several vector tables in the ROM and selecting the optimal vector table according to the digitized APL data, the R, G, B, and R: It is provided to the memory unit 3 in the form of B data.

In the memory unit 3, for the PDP gradation processing, it is necessary to reconstruct the video data of one field into a plurality of subfields, and then rearrange from the most significant bit MSB to the least significant bit LSB. In addition, since the image data input by the interlaced scanning method is converted to the progressive scanning method and displayed, an area for storing one frame of image data is required. In other words, two frame memories capable of storing one piece of image data (853 x 3 (RGB) x 480 x 8 Bits x 10 Mbit) are provided, and they alternately perform write and read operations in units of frames. The video data can be stored and displayed continuously. Furthermore, one field is divided into several subfields in the PD tone gradation process, and the image data corresponding to each subfield is read in sequence and provided to the data interface unit 4.

The data interface unit 4 temporarily stores R, G and B data from the memory unit 3 and provides the data in the form of data required by the address driver IC 6. It is required to be arranged in accordance with the R, G, and B pixel arrangements output from the memory section 3 and supplied to the address driver IC 6, which is why the data interface section 4 is required.

In the case where the display size is 853 x 3 (R, G, B) x 480 mode in the PDTV system, the data interface unit 1 is equivalent to one line (853 x 3 = 2559 bits). It is necessary to temporarily store the data of the system. Since the continuity of the data must be guaranteed (input and output are performed simultaneously), a temporary storage area of 2 lines (2559 x 2 = 5118 bits) is required. That is, a total of 24 bits of data of 8 bits each of R, G, and B from the memory unit 3 are sequentially inputted (107 times) into the first temporary storage area (24 bits x 107 = 259 bits), and the same time interval As a result, the data of one previous line of the second temporary storage area is output in the form of a data stream required by the address driver IC 6. Such input / output operations occur alternately in the first and second temporary storage areas. That is, after the first temporary storage area operates in the input mode and the second temporary storage area operates in the output mode, the operation is then reversed. When outputting the temporarily stored image data to the address driver IC 6, the data interface unit 4 provides one bit of data and a total of 48 bits of image data to each driver IC in the form of a stream. When data is input to the driver IC in turn (75 times) in this manner, when shifted in parallel, one line (48 bits x 75 = 3600 bits) of image data is loaded into the address driver IC 6. Since this process should be the same as the input mode operation time of other temporary storage areas, the input mode should be operated at twice the frequency of the output mode.

The high voltage driving circuit unit 8 combines the DC high voltage supplied from the logic power unit 9 according to the control pulses of various logic levels output from the timing controller unit 5 to the address, scan, and sustain drive ICs 7. Generate the necessary control pulses to drive the PD. In addition, the data stream provided from the data interface unit 4 to the address driver IC 6 is also raised to an appropriate voltage level to enable selective writing on the panel. As described above, the driving method for the PD gradation process first divides one field (60 Hz) into several subfields (64 gradations: 6 subfields, 256 gradations: 8 subfields), and then divides image data corresponding to each subfield. Through the address driving IC 6, writing is performed in units of lines. In the subfield to which MSB data is written, the number of discharge sustain pulses is reduced in order from the LSB subfield, and gradation processing is performed in the total discharge sustain period according to a combination thereof. In addition, the driving sequence of all subfields repeats operations of full screen writing and erasing, data writing, and discharge holding (screen display).

The logic power unit 9 generates and supplies the high voltage required to combine the electrode driving pulses with the AC power as an input, and the DC voltage required by each unit constituting the other PDTV system. In addition, the microcomputer 11 is provided with a power control port, by applying a control signal to the logic power unit 9 and the high voltage driving circuit unit 8 so that the power on / off operation can be performed safely.

3 is a waveform diagram of power supply on / off of the PDTV according to the present invention. In the operation of the high voltage driving voltage, as shown in the waveform diagram of FIG. Reference numeral 20 denotes an off switching of the power supply. In addition, reference numeral 30 shown in the logic voltage represents a power-on setting time of several hundred milliseconds, and reference numeral 40 represents a power-off setting time of several hundred milliseconds.

That is, as shown in FIG. 3, the power control port of the microcomputer 11 is divided into two parts of the high voltage driving circuit part 8 side and the logic power part 9 side. After switching on and passing a certain time, the logic power unit 9 performs normal operation, and then turns on the power of the high voltage driving circuit unit 8. On the contrary, when the power supply is switched off, the power supply of the high voltage driving circuit unit 8 is first switched off, and the power supply of the logic power unit 9 is switched off to safely turn off the power supply.

As described above, in the present invention, the power supply control port of the microcomputer is separated into the high voltage driving circuit portion and the logic power portion, thereby switching the power on and off, thereby making the power on / off operation safe.

Claims (3)

In the power on / off method of the PDTV system, Dividing the logic power unit 9 of the microcomputer 11 and the power control port of the high voltage driving circuit unit 8 into two parts; A power-on switching step of dividing the power control port into two parts, and the logic power unit 9 is first switched on, and the power supply of the high voltage driving circuit unit 8 is switched on after a predetermined time passes; A power on / off method of a PDTV, comprising a power off switching step of first switching off the power supply of the high voltage driving circuit section (8) and then off switching the power supply of the logic power section (9). 2. The power supply switching step according to claim 1, wherein the power-on switching step turns on the power supply of the high voltage driving circuit part 8 after the logic power supply 9 is switched on and the power-on setting time of several hundred milliseconds has passed. Power on / off method of PDTV to set. The power supply of the logic power supply unit (9) according to claim 1, wherein the power off switching step includes a power supply of the logic power supply unit (9) after a power off setting time of several hundred milliseconds after the power supply of the high voltage driving circuit unit (8) is switched off. A power on / off method for a PDTV, characterized in that the power is turned off.