KR100739071B1 - Plasma display panel and Driving method thereof - Google Patents

Abstract

The present invention relates to a plasma display panel including a plurality of address electrodes, a plurality of scan electrodes and a sustain electrode, and a driving method thereof, the method comprising sensing a temperature of a plasma display panel and selecting a lookup table corresponding to the sensed temperature to control power. Do In addition, if the sensed temperature is above the limit temperature, the power is turned off. By doing so, even if the temperature in the plasma display panel becomes high, it can be controlled to prevent breakage of circuits and elements.

Plasma, PDP, Power Control, Average Signal Level, Temperature

Description

Plasma display panel and driving method thereof

1 is a partial perspective view of an AC plasma display panel.

2 shows a three-electrode surface discharge structure of the plasma display panel.

3 is a diagram showing a relationship between power consumption according to load ratio.

4 shows luminance according to load ratio.

5 is a diagram illustrating such an automatic power table of 128 steps.

6 is a configuration diagram of a plasma display panel according to an embodiment of the present invention.

7 is a diagram comparing the number of sustain pulses according to power variation.

8 is an operation flowchart of a plasma display panel according to an embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel, and more particularly, to a plasma display panel, a driving apparatus and a driving method thereof, which perform automatic power control with a look-up table having various sustain numbers according to temperature.

Recently, flat display devices such as liquid crystal displays (LCDs), field emission displays (FEDs), and PDPs have been actively developed. Among these flat panel display devices, PDPs have advantages of higher luminance and luminous efficiency and wider viewing angles than other flat panel display devices. Therefore, the PDP is in the spotlight as a display device to replace the conventional cathode ray tube (CRT) in a large display device of 40 inches or more.

PDPs are flat display devices that display characters or images using plasma generated by gas discharge, and dozens to millions or more of pixels are arranged in a matrix according to their size. Such PDPs are classified into a direct current type (DC type) and an alternating current type (AC type) according to the shape of the driving voltage waveform applied and the structure of the discharge cell.

In the DC-type PDP, since the electrode is exposed to the discharge space as it is, the current flows in the discharge space while voltage is applied, and there is a disadvantage in that a resistance for current limitation must be made for this purpose. On the other hand, in the AC type PDP, the electrode covers the dielectric layer, so the current is limited by the formation of a natural capacitance component, and the electrode is protected from the impact of ions during discharge.

1 is a partial perspective view of an AC plasma display panel.

As shown in FIG. 1, the scan electrode 4 and the sustain electrode 5 covered with the dielectric layer 2 and the protective film 3 are arranged in parallel on the first substrate 1. A plurality of address electrodes 8 covered with the insulator layer 7 are provided on the second substrate 6. A partition 9 is formed on the insulator layer 7 between the address electrodes 8 in parallel with the address electrode 8. In addition, the phosphor 10 is formed on the surface of the insulator layer 7 and on both side surfaces of the partition wall 9. The first substrate 1 and the second substrate 6 may be arranged with the discharge space 11 therebetween so that the scan electrode 4 and the address electrode 8 and the sustain electrode 5 and the address electrode 8 are orthogonal to each other. It is arranged toward. The discharge space at the intersection of the address electrode 8 and the pair of the scanning electrode 4 and the sustain electrode 5 forms a discharge cell 12.

2 shows a three-electrode surface discharge structure of the plasma display panel.

Referring to FIG. 2, an address electrode is disposed to face the scan electrode and the sustain electrode which are formed in parallel in the discharge space formed by the partition wall. In this structure, a discharge is generated to generate wall charges to select a pixel between the address electrode and the scan electrode, and then a discharge for displaying an image between the scan electrode and the sustain electrode is repeated for a predetermined time.

Here, the wall charge refers to a charge that is formed on the wall of the discharge cell (eg, the dielectric layer) close to each electrode and accumulates in the electrode. This wall charge is not actually in contact with the electrode itself, but here the wall charge is described as "formed", "accumulated" or "stacked" on the electrode. In addition, a wall voltage refers to the potential difference formed in the wall of a discharge cell by wall charge.

In addition to forming a discharge space, the partition wall blocks light generated during discharge to prevent cross talk of neighboring pixels. A plurality of such unit structures are formed on a single substrate in a matrix form, and a fluorescent material is applied to each unit structure to form one pixel, and the pixels are gathered to form a plasma display panel. Plasma display panels, which are currently commercialized, generate a discharge in each pixel, and excite a fluorescent material coated on the inner wall of the pixel with ultraviolet rays generated by the discharge to realize a desired color.

In general, since the plasma display panel has high power consumption due to its driving characteristics, an apparatus for controlling power consumption according to the load ratio of a frame to be displayed is required. As a method of controlling such power consumption, a method of limiting power consumption by using auto power control has been used.

In a typical plasma display panel, luminance has a close relationship with a problem of properly controlling reliability and power consumption by a load applied to a circuit.

The increase in luminance to improve the sensory image quality is subject to certain limitations, and currently has a single power consumption control (APC) according to gradation and screen load ratio, and a single luminance curve according thereto. That is, it has one automatic power control mode (APC_mode).

3 is a diagram illustrating a relationship between power consumption according to a load ratio, and FIG. 4 is a diagram illustrating luminance according to a load ratio.

Referring to FIG. 3, in the relationship between power consumption and load ratio, as the load ratio increases, the number of sustain discharge pulses is reduced to control power in order to prevent an increase in power consumption over a certain level. Accordingly, luminance is reduced as shown in FIG. 4. It becomes a curve.

In order to extract the automatic power control curve according to the load rate, it is controlled by dividing into several stages. Generally, a table of 128 or 256 levels is prepared for automatic power control.

5 is a diagram illustrating such an automatic power table of 128 steps.

Referring to FIG. 5, the total number of sustain pulses corresponding to APCn is expressed as the sum of the number of sustain discharges for each subfield SFn.

On the other hand, the plasma display panel has a problem in that high heat is easily generated due to the structural characteristics of the set SET (closed case), high power consumption, high driving voltage, and a power supply circuit generating a plurality of driving voltages. If this temperature rise persists, the circuit element operating temperature conditions are exceeded, which poses a potential risk of circuit malfunction and even fire.

The technical problem to be achieved by the present invention is to solve the disadvantages of the prior art, by applying a different number of sustain pulses corresponding to the load rate according to the temperature to maintain the temperature in the set at a constant temperature and the drive device and driving method thereof To provide.

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The plasma display panel according to the characteristics of the present invention for solving this problem
A memory including a plurality of lookup tables, each storing a number of sustain pulses corresponding to a load ratio for each temperature section;
A temperature sensing unit for sensing a temperature;
A lookup table determiner which selects a lookup table corresponding to the sensed temperature; And
Automatic power that measures a load ratio of an externally input image signal and reads sustain discharge information corresponding to the measured load ratio from the selected lookup table and generates sustain electrode driving signals and scan electrode driving signals based on the sustain discharge information. It includes a control unit.
In addition, the driving method of the plasma display panel according to an aspect of the present invention
A driving method of a plasma display panel including a plurality of address electrodes, a plurality of scan electrodes and a sustain electrode,
Sensing a temperature of the plasma display panel;
Selecting a lookup table corresponding to a sensed temperature from a memory including a plurality of lookup tables storing a number of sustain pulses corresponding to a load ratio for each temperature section;
Determining a load ratio of an input video signal;
And a fourth step of performing power control by reading sustain discharge information corresponding to the load ratio by referring to the lookup table selected in the second step.
Next, the present invention will be described with reference to the accompanying drawings so that the present invention may be easily implemented by those skilled in the art as follows.

6 is a configuration diagram of a plasma display panel according to an embodiment of the present invention.

Referring to FIG. 6, a plasma display panel according to an exemplary embodiment of the present invention includes a plasma panel 100, an address electrode driver 300, a scan electrode driver (hereinafter referred to as a “Y electrode driver”) 400, and a sustain electrode. Driver (hereinafter, referred to as 'X electrode driver') 500, memory 230, temperature sensor 210, lookup table determiner 220, gamma corrector 240, automatic power controller 250, and sub The field data generator 260 is included.

The plasma panel 100 includes a plurality of address electrodes A1-Am arranged in the column direction, a plurality of sustain electrodes (hereinafter referred to as 'X electrodes') (X1-Xn) and scan electrodes arranged in the row direction. (Hereinafter referred to as 'Y electrode') (Y1-Yn). The X electrodes X1-Xn are formed corresponding to the respective Y electrodes Y1-Yn, and generally have one end connected in common to each other. The plasma panel 100 includes a glass substrate (not shown) on which the X and Y electrodes X1-Xn and Y1-Yn are arranged, and a glass substrate (not shown) on which the address electrodes A1-Am are arranged. . The two glass substrates are disposed to face each other with the discharge space therebetween so that the Y electrodes Y1-Yn and the address electrodes A1-Am and the X electrodes X1-Xn and the address electrodes A1-Am are orthogonal to each other. At this time, the discharge space at the intersection of the address electrodes A1-Am and the X and Y electrodes X1-Xn and Y1-Yn forms a discharge cell.

The memory 230 includes a plurality of lookup tables LUT 1 to LUT N for storing the number of sustain pulses corresponding to the load ratio for each temperature section.

The temperature detector 210 detects temperatures of the X electrode driver 500 and the Y electrode driver 400, and may detect other portions inside and outside the PDP as necessary.

The lookup table determiner 220 selects a lookup table corresponding to the sensed temperature, and causes the automatic power controller 250 to refer to the selected lookup table.

The automatic power controller 250 measures the load ratio of the image signal input from the outside, and outputs the X electrode driving signal and the Y electrode driving signal by bringing the sustain discharge information corresponding to the measured load ratio from the selected lookup table.

The gamma correction unit 240 receives an image signal and performs gamma correction, and the subfield data generator 260 generates the error-diffused image signal as subfield data and outputs it as an address electrode driving signal.

The address electrode driver 300 receives an address electrode driving signal and applies a display data signal to each address electrode A1-Am to select a discharge cell to be displayed.

The X electrode driver 500 receives the X electrode driving signal and applies a driving voltage to the X electrodes X1 to Xn.

The Y electrode driver 400 receives the Y electrode driving signal and applies a driving voltage to the Y electrodes Y1-Yn.

Looking at the calorific value prior to the operation description of the present invention, as can be seen in the relationship between the calorific value and the current, voltage, the calorific value is proportional to the time the current flows (current calorific value ∝ time), when the current is constant, the calorific value when the voltage is the same Is proportional to the current across the resistor (heat output 량 current), and when the current is constant, the calorific value is proportional to the voltage across the resistance (heat output ∝ voltage). In addition, the calorific value is proportional to current, voltage, and time, respectively. As shown in the characteristic of the heat generation amount, it is possible to control the amount of heat generation through current control, and the method of suppressing the high heat generated in the PDP set can be implemented through current control (power consumption control). The present invention relates to a method of applying a plurality of sustain pulse number tables to limit temperature rise and to suppress the occurrence of high heat of the PDP SET.

Next, the operation of the plasma display panel according to the embodiment of the present invention having such a configuration will be described in detail.

First, the calculation of the APC lookup table and the number of sustain pulses will be described. In order to limit the power consumption of the PDP SET, APC (control the power consumption by limiting the number of fat-dielectric pulses) is used and the APC design is performed as follows.

From the measured power characteristic curve, the relation between the load ratio and the power consumption P when the number of sustain discharge pulses Ns is constant is obtained. Since power consumption is linearly proportional to the load factor, power consumption P is approximated to the linear function of L. This is shown in the following equation.

P = Po + a * L (Po: power consumption when L = 0%)

Next, in the relation between power consumption and load factor approximated for each sustain discharge pulse number Ns, Po, a is approximated as a function of Ns, and power consumption P is linearly proportional to Ns, so it is approximated by the first function.

P = f (Ns, L) = Po (Ns) + a (Ns) * L = (A + B * Ns) + (C + D * Ns) * L

In addition, a lookup table including the sustain pulse numbers corresponding to the load ratio can be obtained by the coefficients A, B, C, and D and the power consumptions UPPER and LOWER LIMIT obtained by the measurement.

FIG. 7 graphically displays the number of sustain pulse tables calculated by limiting power consumption (270W-340W, 280W-340W, 290W-340W, 300W-340W, 290W-370W, 300W-380W, 220W-270W).

The temperature sensor monitors the temperature in the plasma display panel set, and when the specific temperature LEVEL.1 (for example, 70 ° C) is reached, the number of sustain pulses is limited (brightness reduction), which directly affects the temperature rise. Reduce power. Through temperature sensing, if the temperature in PDP SET falls below a certain temperature LEVEL.1 (for example 70 ℃), the original sustain pulse number table is applied. If the detection temperature is higher than the specified LEVEL.1 (for example, 70 ℃) to the detection temperature LEVEL.2 LEVEL.3 LEVEL.4 ... LEVEL.N-1, the SUSTAIN PULSE TABLE according to each temperature level is applied. To control the temperature rise. If the temperature rise is not saturated and the detection temperature LEVEL.N is reached, the power is turned off according to the plasma display panel off sequence (SEQUENCE).

In this way, the temperature is divided into N levels, and a lookup table is created for each level and stored in the memory 230. If the temperature is above the final N level, the power is turned off.

Next, the operation of the plasma display panel which actually operates according to the temperature will be described.

8 is an operation flowchart of a plasma display panel according to an embodiment of the present invention.

When an external video signal is input, the gamma correction unit 240 outputs the gamma correction according to the R, G, and B correction ratios stored therein.

Then, the subfield data generator 260 generates the gamma corrected image signal as subfield data and outputs the gamma corrected image signal as an address electrode driving signal.

Meanwhile, the temperature detector 210 senses and outputs the temperatures of the X electrode driver 500 and the Y electrode driver 400 (S801), and may detect other portions inside and outside the plasma display panel as necessary.

Then, the lookup table determiner 220 compares the sensed temperature with levels 1 to level N to determine which level it belongs to, and applies a sustain pulse number table of the corresponding level (S802 to S808).

At this time, if the detected temperature is greater than level N, the lookup table determiner 220 outputs a control signal to the power supply device 600 to turn off the power (S809).

According to an embodiment of the present invention, the calculated APC level and the sustain pulse number table are applied to reduce the power consumption to saturate or lower the rising temperature.

However, when such temperature does not go down but rises continuously and becomes above the N level, the power is turned off. Specifically, if the detected temperature becomes LEVEL.N, turn off the power supply by turning off the power board (VS_ON DISABLE), and if the user turns on the PDP while the detected temperature is in LEVEL.N, VS_ON SIGNAL (Logic board → power board) Disables the control signal) to stop the PFC stage operation of the power supply (power board).

On the other hand, the automatic power control unit 250 calculates the load ratio of the gamma corrected image signal, and reads the sustain discharge information corresponding to the load ratio from the lookup table selected by the lookup table determiner 220 to drive the sustain electrode. A signal and a scan electrode driving signal are generated and applied to the X electrode driver 500 and the Y electrode driver 400, respectively.

Then, the address electrode driver 300 receives the address electrode drive signal from the subfield data generator 290 and applies a display data signal for selecting a discharge cell to be displayed to each address electrode A1-Am. .

In addition, the X electrode driver 500 receives the X electrode driving signal from the automatic power controller 230, applies a driving voltage to the X electrodes X1-Xn, and the Y electrode driver 400 is the automatic power controller 230. The drive signal is received from the Y electrode, and a driving voltage is applied to the Y electrodes Y1-Yn.

Then, image data is displayed on the plasma panel 100.

According to the exemplary embodiment of the present invention, as a solution to the high heat generated in the plasma display panel set, the temperature rise is suppressed and the high heat is generated by using a plurality of sustain pulse number tables according to the temperature rise level when the temperature rises above a certain standard. Can be prevented.

Such embodiments of the present invention may be variously modified, and if necessary, the lookup table may be calculated and applied. In other words. The sustain pulse number table may be calculated according to the detected temperature level, and the calculated table may be applied. In this case, the calculation factor applies the sustain pulse number table which lowers the power consumption as the temperature increases based on the power consumption. In addition, when the changed sustain pulse number table is applied, the user may be alarmed through an on screen display.

The present invention is not limited to the above embodiments, but may be modified and improved by those skilled in the art within the spirit and scope of the invention as defined in the claims.

As described above, in the exemplary embodiment of the present invention, the number of sustain pulses may be differently applied according to the temperature to lower the temperature of the plasma display panel and to turn off the power when the temperature exceeds the threshold temperature, thereby protecting circuits and elements in the plasma display panel. .

Claims (8)

A memory including a plurality of lookup tables, each storing a number of sustain pulses corresponding to a load ratio for each temperature section; A temperature sensing unit for sensing a temperature; A lookup table determiner which selects a lookup table corresponding to the sensed temperature; Automatic power that measures a load ratio of an externally input image signal and reads sustain discharge information corresponding to the measured load ratio from the selected lookup table and generates sustain electrode driving signals and scan electrode driving signals based on the sustain discharge information. A plasma display panel comprising a control unit. The method of claim 1, And the lookup table determiner outputs a control signal to a power supply to turn off the power when the sensed temperature is above a threshold temperature. The method according to claim 1 or 2, And the number of sustain pulses stored in the memory decreases as temperature increases. delete delete A driving method of a plasma display panel including a plurality of address electrodes, a plurality of scan electrodes and a sustain electrode, Sensing a temperature of the plasma display panel; Selecting a lookup table corresponding to a sensed temperature from a memory including a plurality of lookup tables storing a number of sustain pulses corresponding to a load ratio for each temperature section; Determining a load ratio of an input video signal; And a fourth step of performing power control by reading sustain discharge information corresponding to the load ratio by referring to the lookup table selected in the second step. The method of claim 6, And turning off the power if the sensed temperature is greater than or equal to the threshold temperature. The method of claim 7, wherein In the second step, the look-up table is selected such that the number of sustain pulses becomes smaller as the temperature increases.

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