KR20030072797A - Method and apparatus for driving plasma display panel - Google Patents

Abstract

PURPOSE: A method and an apparatus for driving a plasma display panel are provided to correct a voltage according to an operating time of the plasma display panel and stabilize a discharging characteristic by installing a power control unit at the plasma display panel. CONSTITUTION: An apparatus for driving a plasma display panel includes a voltage generation portion(70), a timer(84), and a voltage control portion(88). The voltage generation portion(70) generates a voltage to drive the plasma display panel. The timer(84) is used for detecting an operating time of the plasma display panel. The voltage control portion(88) controls the driving voltage of according to the detected time. The voltage control portion(88) includes a ROM table(82) and a data control portion(86). The ROM table(82) is used for storing the controlled driving voltage data. The data control portion(86) extracts the corresponding driving voltage data according to the operating time from the ROM table(82).

Description

Method and apparatus for driving plasma display panel {Method and Apparatus for Driving Plasma Display Panel}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel, and more particularly, to a method and apparatus for driving a plasma display panel capable of preventing image quality degradation by correcting a driving voltage in consideration of a use time.

Plasma Display Panel (hereinafter referred to as "PDP") displays an image including text or graphics by emitting phosphors by 147 nm ultraviolet rays generated during discharge of He + Xe or Ne + Xe inert mixed gas. . Such a PDP is not only thin and easy to enlarge, but also greatly improved in quality due to recent technology development. In particular, the three-electrode AC surface discharge type PDP has advantages of low voltage driving and long life because wall charges are accumulated on the surface during discharge and protect the electrodes from sputtering caused by the discharge.

1 is a view showing a driving apparatus of a conventional three-electrode alternating surface discharge type PDP.

Referring to FIG. 1, in the driving apparatus of a conventional three-electrode alternating current surface discharge type PDP, m × n discharge cells 1 include scan electrodes Y1 to Ym, sustain electrodes Z1 to Zm, and address electrodes X1 to. PDP 30 arranged in a matrix form to be connected to Xn, a scan driver 32 for driving the scan electrodes Y1 to Ym, and a sustain driver 34 for driving the sustain electrodes Z1 to Zm. And an address driver 36 for driving the address electrodes X1 to Xn.

The scan driver 32 sequentially supplies scan pulses and sustain pulses to the scan electrodes Y1 to Ym so that the discharge cells 1 are sequentially scanned in line units, and m × n discharge cells 1 ) The discharge at each of them is sustained. The sustain driver 34 alternates with the scan driver 32 to supply sustain pulses to all of the sustain electrodes Z1 to Zm. The address driver 36 supplies image data to the address electrodes X1 to Xn in synchronization with the scan pulse.

The three-electrode AC surface discharge type PDP 30 is driven by being divided into a plurality of subfields, and gray scale display is performed by emitting light a number of times proportional to the weight of video data in each subfield period. For example, when an image is displayed in 256 gray scales using 8-bit video data, one frame display period (for example, 1/60 second = about 16.7 msec) in each discharge cell 1 is shown in FIG. As shown, the data is divided into eight subfields SF1 to SF8. Each subfield SF1 to SF8 is further divided into a reset period, an address period and a sustain period, and 1: 2: 4: 8:... The weight is given at the ratio of 128. Here, the reset period is a period for initializing the discharge cells, the address period is a period during which selective address discharge occurs according to the logic value of the video data, and the sustain period is such that discharge is maintained in the discharge cells in which the address discharge has occurred. It is a period. The reset period and the address period are equally allocated to each subfield period.

3 is a driving waveform diagram of a plasma display panel according to the related art, in which a reset waveform of a ramp waveform is used in the reset period of all subfields during one frame.

Referring to FIG. 3, the reset pulse RP is supplied to the scan electrode Y in the reset period RPD of all the subfields SF1 to SF8. The reset pulse RP has a form of ramp wave in which the voltage increases when set up and the voltage decreases when set down. A reset discharge occurs during setup to form wall charges in the upper dielectric layer 14. Subsequently, the charged voltage is partially erased by the decreasing voltage during set down so that the wall charge is reduced enough to help the next address discharge without causing an erroneous discharge. In order to reduce the wall charge, a positive DC voltage is supplied to the sustain electrode Z when the reset pulse RP is set down. Since the reset pulse RP is supplied in a gradually decreasing form with respect to the positive DC voltage, the scan electrode Y becomes a negative polarity relative to the sustain electrode Z at the time of set down, that is, the polarity is reduced. This inversion reduces the wall charges generated during setup.

In the address period APD, the scan pulse SP having the negative scan voltage Vy is supplied to the scan electrode Y, and the data pulse DP corresponding to the address voltage Va is applied to the address electrode X. Is supplied to generate an address discharge. The wall charge formed by this address discharge is maintained for the period during which the other discharge cells are addressed.

The triggering pulse TP is supplied to the scan electrode Y at the beginning of the sustain period SPD to start sustain discharge in the discharge cells 1 in which wall charges are sufficiently formed in the address period APD. Subsequently, sustain pulses SUSPz and SUSPy corresponding to the sustain voltage Vs are alternately supplied to the sustain electrode Z and the scan electrode Y to maintain the sustain discharge during the sustain period SPD.

In the erase period EPD subsequent to the sustain period SPD, the discharge pulse EP is supplied to the sustain electrode Z to stop the discharge. The erasing pulse EP has a ramp wave shape so that the light emission size is small, or a short pulse width of about 1 ms for the discharge erasing. The charged particles are erased by the short erase discharge by the erase pulse EP to stop the discharge.

When the PDP is used for a long time, the phosphor deteriorates or the dielectric or protective film deteriorates, and thus the sustain voltage Vs, the address voltage Va, and the setup voltage Vsetup for driving the PDP are changed. This results in a constant voltage output from the circuit but alters the discharge characteristics of the panel. For example, the discharge does not occur when the PDP is applied to the PDP after about 1000 hours using the firing voltage set at the time of product shipment. As a result, problems such as mis-discharge, miss address, unstable sustain discharge, or unstable initialization due to PDP usage time appear.

Accordingly, it is an object of the present invention to provide a method and apparatus for driving a PDP capable of stabilizing discharge characteristics in consideration of usage time.

1 is a view showing a driving apparatus of a conventional three-electrode AC surface discharge type plasma display panel.

2 is a frame configuration diagram according to a conventional subfield driving method.

FIG. 3 is a drive waveform diagram for driving the plasma display panel shown in FIG. 1 for one frame. FIG.

4 is a diagram illustrating a driving apparatus of a plasma display panel according to an exemplary embodiment of the present invention.

5 is a detailed view of the power supply circuit shown in FIG.

6 is a graph showing a relationship between correction voltages according to usage times of plasma display panels.

<Brief description of symbols for the main parts of the drawings>

1: discharge cell 32: scan / sustain driver

34: common sustain driver 36: address driver

50: timing controller 60: power supply circuit

70: drive voltage generation unit 82: ROM table

84: timer 86: data control unit

88: control unit

In order to achieve the above object, the driving method of the plasma display panel according to the present invention comprises the steps of setting the driving voltage of the panel, detecting the operating time of the panel, and adjusting the driving voltage of the panel according to the detected time Characterized in that it comprises a step.

The setting of the driving voltage may further include setting driving voltage data according to a usage time and storing the driving voltage data in a ROM table.

The driving apparatus of the plasma display panel according to the present invention includes a voltage generator for generating a driving voltage of the panel, a timer for detecting the use time of the panel, and a voltage controller for adjusting the driving voltage of the panel according to the detected time. Characterized in that.

The voltage controller may further include a ROM table that stores driving voltage data adjusted according to a usage time, and a data controller that extracts corresponding driving voltage data according to the usage time of the panel from the ROM table.

The driving voltage may include at least one of a reference voltage, a sustain voltage, an address voltage, a setup voltage, a scan reference voltage, and a scan voltage.

Other objects and advantages of the present invention in addition to the above object will be apparent from the description of the preferred embodiment of the present invention with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 4 to 6.

In this invention, the same code | symbol is considered to be the same as the prior art.

Referring to FIG. 4, the driving apparatus of the PDP according to the embodiment of the present invention has a power control unit 60 that controls the power to correct the discharge voltage in consideration of the panel use time.

In addition, the driving device of the PDP includes a common power supply 62 for supplying the common voltage Vpp to the power supply control unit 60, and the scan electrodes Y1 to Ym and the sustain electrodes of m x n discharge cells 1. PDP 30 arranged in a matrix so as to be connected to Z1 to Zm and the address electrodes X1 to Xn, a scan driver 32 for driving the scan electrodes Y1 to Ym, and a sustain electrode Z1. Sustain driver 34 for driving to Zm, address driver 36 for driving address electrodes X1 to Xn, scan driver 32, sustain driver 34, and address driver 36 In addition, a timing controller 50 for supplying a control signal is further provided.

The timing controller 50 supplies a timing control signal to the scan driver 32, the sustain driver 34, and the address driver 36.

The scan driver 32 sequentially supplies scan pulses and sustain pulses to the scan electrodes Y1 to Ym in response to control signals input from the timing controller 50 so that the discharge cells 1 are sequentially line-by-line. In addition to scanning, discharge is continued in each of the m x n discharge cells 1.

The sustain driver 34 supplies sustain pulses to the sustain electrodes Z1 to Zm in response to control signals input from the timing controller 50.

The address driver 36 supplies image data to the address electrodes X1 to Xn in synchronization with the scan pulse in response to the control signals input from the timing controller 50.

The power control unit 60 receives the common voltage Vpp from the common power supply 62 and supplies a driving voltage to each of the scan driver 32, the sustain driver 34, and the address driver 36. In other words, the power supply controller 60 supplies the setup voltage Vsetup to the scan driver 32 during the setup period, and the negative scan voltage Vy and the scan reference voltage to the scan electrodes Y1 to Ym during the address period. Supply (Vsc). In addition, the sustain voltage Vs is supplied to the scan driver 32 during the sustain period. In addition, the power supply controller 60 supplies the sustain voltage Vs to the sustain driver 34 to maintain the discharge during the sustain period, and supplies the voltage to the address electrodes X1 to Xn for the address discharge during the address period. The address voltage Va is supplied to the driver 36.

The power control unit 60 includes a control unit 88 for controlling the driving voltage supplied to each driving unit as shown in FIG. 5, and a voltage generating unit 70 generating the driving voltage.

The controller 88 controls the ROM table 82 in which the correction voltage data according to the usage time of the panel is stored, and the correction voltage data from the ROM table 82 to the voltage generator 70. And a timer 84 connected to the ROM table 82 and the data control unit 86.

The timer 84 supplies the usage time information of the PDP 30 to the ROM table 82 or a look-up table. The timer 84 may be reset by a set maker at the time of product shipment to start counting, or may be reset and start counting when the user first turns on the power.

In the ROM table 82, a table of correction voltage values according to usage time of a panel is stored in a ROM. When the PDP 30 is used for a long time, the phosphor, the dielectric, or the protective film are deteriorated and the image quality is reduced, so the driving voltage should be changed to prevent this.

The driving voltage is corrected with the correction voltage data stored in the ROM table 82 according to the usage time of the PDP 30. The correction voltage data stored in the ROM table 82 has a value that increases as the usage time of the PDP 30 increases. For example, as shown in the graph of FIG. 7, the sustain voltage Vs and the address voltage Va increase as the usage time of the PDP 30 increases.

The data controller 86 reads the correction voltage corresponding to the usage time supplied from the timer 84 from the ROM table 82 and supplies the correction voltage to the voltage generator 70.

The voltage generator 70 may include a sustain voltage Vs generator 72, an address voltage Va generator 74, and a level shifted common voltage supplied from the common power supply 62 to the PDP 30. A setup voltage generator 76, a scan reference voltage Vsc generator 78, and a scan voltage Vy generator 80 are provided.

The sustain voltage Vs generating unit 72 generates the sustain voltage Vs during the sustain period, and supplies the sustain voltage Vs to the scan electrodes Y1 to Ym and the sustain electrodes Z1 to Zm.

The address voltage Va generating unit 74 generates the address voltage Va during the address period to supply the address voltage Va to the address electrodes X1 to Xm.

The setup voltage Vsetup generating unit 76 generates the setup voltage Vsetup during the setup period and supplies the setup voltage Vsetup to the scan electrodes Y1 to Ym.

The scan reference voltage Vsc generating unit 78 generates the scan pulse reference voltage Vsc during the address period and supplies the scan pulse reference voltage Vsc to the scan electrodes Y1 to Ym.

The scan voltage Vy generator 80 generates the scan voltage Vy during the address period and supplies the scan voltage Vy to the scan electrodes Y1 to Ym.

As such, since the driving voltage can be changed according to the time of use of the PDP, the discharge characteristic of the PDP according to the present invention is increased even when the phosphor, the dielectric, or the protective film are deteriorated.

As described above, the method and apparatus for driving a PDP according to the present invention include a power supply control unit that can correct a voltage according to a PDP usage time. Accordingly, even if the phosphor deteriorates or the dielectric or protective film deteriorates, the discharge characteristics of the panel can be stabilized. Furthermore, the method and apparatus for driving a PDP according to the present invention can realize a clear image even when the PDP is used for a long time.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (7)

Setting a driving voltage of the panel; Detecting a usage time of the panel; And adjusting the driving voltage of the panel according to the detected time. The method of claim 1, The setting of the driving voltage Setting driving voltage data according to the usage time; And storing the driving voltage data in a ROM table. The method of claim 2, The setting of the driving voltage Selecting driving voltage data stored in the ROM table according to the detected usage time; And adjusting the voltage level of the driving voltage in response to the selected driving voltage data. The method of claim 1, And the driving voltage includes at least one of a reference voltage, a sustain voltage, an address voltage, a setup voltage, a scan reference voltage, and a scan voltage. A voltage generator for generating a driving voltage of the panel; A timer for detecting a use time of the panel; And a voltage controller for adjusting the driving voltage of the panel according to the detected time. The method of claim 5, The voltage control unit includes a ROM table storing driving voltage data adjusted according to a usage time; And a data control unit for extracting the corresponding driving voltage data according to the usage time of the panel from the ROM table. The method of claim 5, And the driving voltage includes at least one of a reference voltage, a sustain voltage, an address voltage, a setup voltage, a scan reference voltage, and a scan voltage.