KR100719577B1 - Apparatus of driving display panel - Google Patents

Abstract

The present invention relates to a display panel driving apparatus capable of interrupting a surge current flowing through a terminal of a power conversion circuit for generating a required voltage level. A plasma display panel driving apparatus according to the present invention is a display panel driving apparatus for applying a driving signal to the display panel to drive a display panel, the apparatus for generating output voltages of a plurality of voltage levels used for the driving signal. And a protection unit for detecting the abnormality of the power conversion circuit and controlling the operation of the power conversion circuit to protect the driving device. According to the present invention, it is possible to protect the drive device including the power conversion circuit by cutting off the surge current flowing through the terminal of the power conversion circuit.

Description

Apparatus of driving display panel

1 is a view showing an embodiment of the structure of a plasma display panel driven by the driving apparatus of the present invention.

FIG. 2 is a view schematically illustrating an electrode arrangement of the plasma display panel of FIG. 1.

FIG. 3 is a block diagram schematically illustrating an apparatus for driving a plasma display panel for driving the plasma display panel of FIG. 1.

4 is a timing diagram illustrating an embodiment of a drive signal output from each driver of FIG. 3.

5 is a view showing a driving device of the present invention having a power conversion circuit including a protection unit.

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

12: logic controller, 14: Y drive unit,

18: X driver, 16: address driver,

400: power supply, 402: transformer,

404: output voltage detector, 406: voltage controller,

420: protection.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display panel driver, and more particularly, to a display panel driver capable of blocking a surge current flowing through a terminal of a power conversion circuit that generates a required voltage level.

As flat panel display devices, plasma display panels (PDPs), which are easy to manufacture large panels, have attracted attention. A plasma display panel is a display device that displays an image by using a discharge phenomenon. In general, a plasma display panel can be classified into a direct current type and an alternating current type according to the type of driving voltage. Due to the disadvantages, the development of the AC plasma display panel has been made a lot.

An AC plasma display panel includes a three-electrode AC surface discharge type plasma display panel having three electrodes and driven by an AC voltage. A typical three-electrode surface discharge type plasma display panel is composed of a multi-layered plate, which is spatially advantageous because it can provide a thinner, lighter, and wider screen than a conventional cathode ray tube (CRT).

As an example of a conventional plasma display panel, a three-electrode surface discharge plasma display panel, a driving apparatus thereof, and a driving method thereof are disclosed in US Patent No. 6,744,218 (name: Method of driving a plasma display panel in which the). width of display sustain pulse varies). Matters related to the plasma display panel, the driving apparatus, and the driving method disclosed in the above-mentioned US patent are included in the present specification, and a detailed description thereof will be omitted.

A driving apparatus of a plasma display panel for driving a plasma display panel applies a respective driving signal to a plurality of electrodes, and each driving signal is composed of various levels of voltage. In order to supply such various levels of voltage to the driving device of the plasma display panel, a power supply unit is separately required.

However, there is a problem in that voltages of various levels output from the power supply unit drop due to the length of the wirings between the power supply unit and the driving device, resulting in voltage loss. Therefore, in order to overcome this problem, the voltage level converting circuit can be arranged in the driving apparatus.

However, when the voltage level conversion circuit disposed in the drive device malfunctions, such as when a surge current flows, there is no protection against this, and even the drive device including the voltage level conversion circuit disposed in each drive unit is damaged. There is a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has an object of providing a display panel driving apparatus including a power conversion circuit for generating a required voltage level, and capable of blocking a surge current flowing through a terminal of the power conversion circuit. It is done.

In the display panel driving apparatus according to the present invention for achieving the above object, a plurality of voltages used for the driving signal in the display panel driving apparatus for applying a driving signal to the display panel to drive the display panel And a power conversion circuit for generating a level output voltage, wherein the power conversion circuit detects an abnormality of the power conversion circuit and controls an operation of the power conversion circuit to protect the driving device.

The protection unit may detect a surge current flowing through a terminal of the power conversion circuit, and cut off the current flow.

It is preferable that the said protection part consists of a fusible resistor which interrupts the flow of a surge current.

The power conversion circuit may include: a transformer configured to transform an input voltage Vin to output the plurality of output voltages; An output voltage detector for detecting at least one output voltage among the plurality of output voltages and outputting a detection signal; And a voltage controller for outputting a switching pulse signal according to the detection signal to the transformer to adjust the output voltage.

It is preferable that the transformer part comprises at least one transformer.

The output voltage detector includes a photocoupler, and detects the output voltage and outputs the detection signal to the voltage controller through the photocoupler.

The voltage control unit is driven by the driving voltage Vcc received and stored in the input voltage Vin, and is output to the transformer so that the driving voltage is transformed, and the pulse width modulation PWM according to the detection signal. It is preferable to generate a) and output a switching pulse signal which is switched by the pulse width modulation signal to the transformer.

According to another aspect of the present invention, a display panel driving apparatus includes a display panel driving apparatus for applying a driving signal to the display panel to drive a display panel, the output panel having a plurality of output voltage levels used for the driving signal. And a power conversion circuit which senses a surge current flowing in the circuit and cuts off the current flow.

The power conversion circuit may include: a transformer configured to transform an input voltage Vin to output the plurality of output voltages; An output voltage detector for detecting at least one output voltage among the plurality of output voltages and outputting a detection signal; A voltage controller configured to adjust the output voltage by outputting a switching pulse signal according to the detection signal to the transformer; And a protection unit which senses a surge current flowing through the terminal of the power conversion circuit and blocks the current flow.

According to the present invention, it is possible to protect the drive device including the power conversion circuit by cutting off the surge current flowing through the terminal of the power conversion circuit.

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

1 is a view showing an embodiment of the structure of a plasma display panel driven by the driving apparatus of the present invention.

Referring to the drawings, in between the first substrate 100 and second substrate 106 of the PDP, A electrodes (A _1, ..., A _m), the first and second dielectric layers (102 110 ), Y electrodes (Y ₁ , ..., Y _n ), X electrodes (X ₁ , ..., X _n ), phosphor layer 112, partition wall 114, and magnesium monoxide (MgO) protective layer 104 is provided.

The A electrodes A ₁ ,..., A _m are formed in a predetermined pattern on the second substrate 106 in the direction of the first substrate 100. A second dielectric layer 110 is applied so as to cover the A electrodes _{(A 1, ..., A m} ). The partition wall 114 is formed on second dielectric layer 110 are formed in a direction parallel to the A electrodes _{(A 1, ..., A m} ). The partition walls 114 function to partition the discharge region of each discharge cell and to prevent optical interference between the discharge cells. A phosphor layer 112 is the A electrodes between the barrier ribs (114) (A _1, ..., A _m) is first applied onto the second dielectric layer 110, in sequence a red light-emitting phosphor layers, green light-emitting fluorescent substance on the Layer and a blue light emitting phosphor layer are disposed.

X electrodes _{(X 1, ..., X n} ) and Y electrodes _{(Y 1, ..., Y n} ) is orthogonal to the second substrate such that the A electrodes _{(A 1, ..., A m} ) It is formed in a predetermined pattern on the first substrate 100 in the (106) direction. Each intersection sets a corresponding discharge cell. Each of the X electrodes (X ₁ , ..., X _n ) and each of the Y electrodes (Y ₁ , ..., Y _n ) may be formed of a transparent conductive material (X _na , Y _na )) and the metal electrodes X _nb and Y _nb for increasing conductivity may be formed. The first dielectric layer 102 is formed by covering the X electrodes X ₁ ,..., X _n and the Y electrodes Y ₁ ,..., And Y _n . A protective layer 104 for protecting the panel from a strong electric field, for example, a magnesium monoxide (MgO) layer, is formed over the entire surface to cover the first dielectric layer 102. The plasma forming gas is sealed in the discharge space 108.

Meanwhile, the plasma display panel driven by the driving apparatus of the present invention is not limited to that shown in FIG.

FIG. 2 is a view schematically illustrating an electrode arrangement of the plasma display panel of FIG. 1.

Referring to the drawings, the Y electrodes (Y ₁ ,..., Y _n ) and the X electrodes (X ₁ , ..., X _n ) are arranged side by side in parallel, and the A electrodes (A ₁ , ..., a _m) are arranged so as to cross the Y electrodes _{(Y 1, ..., Y n} ) and the X electrodes _{(X 1, ..., X n} ), the intersection region is a discharge cell ( Ce) is partitioned.

FIG. 3 is a block diagram schematically illustrating an apparatus for driving a plasma display panel for driving the plasma display panel of FIG. 1.

Referring to the drawings, the driving apparatus of the plasma display panel includes an image processor 10, a logic controller 12, a Y driver 14, an address driver 16, an X driver 18, and a plasma display panel 1. Equipped. The image processing unit 10 converts an external image signal from the outside and outputs it as an internal image signal, and the logic controller 12 receives an internal image signal, respectively, an address driving control signal S _A and a Y driving control signal ( S _Y ) and an X driving control signal S _X are output, and the Y driving unit 14, the address driving unit 16, and the X driving unit 18 receive driving control signals, respectively, and Y electrodes of the plasma display panel 1. And a driving signal is output to each of the A electrodes and the X electrodes.

4 is a timing diagram illustrating an embodiment of a drive signal output from each driver of FIG. 3.

Referring to FIG. 4, a unit frame for driving the plasma display panel (1 of FIG. 3) is divided into a plurality of subfields, and each subfield SF includes a reset period PR and an address period PA. And maintenance period PS.

First, in the reset period PR, a reset pulse consisting of a rising pulse and a falling pulse is applied to the Y electrodes Y ₁ , ..., Y _n , and in the X electrodes X ₁ , ..., X _n . When the falling pulse is applied, the second voltage (bias voltage) is applied to reset discharge. All discharge cells are initialized by reset discharge. The rising pulse rises from the sustain discharge voltage (Vs) by the rising voltage (V _set ) and finally reaches the rising maximum voltage (V _set + Vs), and the falling pulse falls from the sustain discharge voltage (Vs) and finally falls The voltage V _nf is reached.

In the address period PA, scanning pulses are sequentially applied to the Y electrodes Y ₁ ,..., And Y _n , and A electrodes A ₁ ,..., A _m are displayed in accordance with the scanning pulses. The data signal is applied to perform address discharge. The discharge cells to be subjected to the sustain discharge occurring in the sustain period PS by the address discharge are selected. The scan pulse has a scan high voltage (Vsch) and sequentially has a scan low voltage (Vscl) whose voltage is lower than the scan high voltage (Vsch), and the display data signal is adapted to the scan low voltage (Vscl) of the scan pulse. It has a positive address voltage Va.

In the sustain period PS, a sustain pulse is alternately applied to the X electrodes X ₁ ,..., X _n and the Y electrodes Y ₁ ,..., Y _n to perform a sustain discharge. Luminance is expressed according to the gray scale weight allocated to each subfield by the sustain discharge. The sustain pulse has an alternating discharge voltage Vs and a ground voltage Vg.

On the other hand, it is possible to output a drive signal different from that shown in FIG. 4 in each of the driving units of FIG.

5 is a view showing a driving device of the present invention having a power conversion circuit including a protection unit.

Referring to the drawings, the driving apparatus of the present invention is a display panel driving apparatus for applying a driving signal to the display panel to drive the display panel, the output voltage of a plurality of voltage levels used for the driving signal By generating a, it is provided with a power conversion circuit 400 for detecting the surge current flowing in the circuit, blocking the current flow.

Here, the driving device of the present invention may be the Y driver 104, the address driver 106 or the X driver 108 shown in FIG. 3, and preferably the Y driver 104 using various voltage levels. Can be.

The power conversion circuit 400 outputs a plurality of output voltages used for the driving signal, and the protection units 420a and 420b detect when there is an abnormality among the plurality of output voltages output from the power conversion circuit 400. By controlling the operation of the power conversion circuit 400 to protect the driving device.

In particular, the protection units 420a and 420b sense a surge current flowing through the power conversion circuit 400 to block the current flow. Here, the protection parts 420a and 420b are preferably made of a fusible resistor that automatically opens when the surge current exceeds a predetermined rated current flows on the line, thereby blocking the circuit.

First, the power conversion circuit 400 includes a transformer 402, an output voltage detector 404, a voltage controller 406, and protection units 420a and 420b. The transformer 402 receives the input voltage V _in from the outside and transforms the voltage to output a plurality of output voltages.

The transformer 402 may include a transformer, and may include at least one transformer to output a plurality of output voltages. The voltage level of the output voltage is determined by the turns ratio of the transformer. In the drawing, the power conversion circuit is provided with two transformers T1 and T2 and outputs four first, second, third, and fourth output voltages Vout1, Vout2, Vout3, and Vout4. It is not limited to this.

The first output voltage Vout1 is the ground voltage (Vg in FIG. 3), the second output voltage Vout2 is the scan high voltage (Vsch in FIG. 3), and the third output voltage Vout3 is the switching element in the driving apparatus (not shown). The switching voltage (approximately 15V, not shown) and the fourth output voltage Vout4 driving the C) may be a scan low voltage (Vscl of FIG. 4).

Once the third output voltage Vout3 is a switching voltage (approximately 15 V) for driving various switching elements (not shown) in the driving apparatus, the driving apparatus when the switching voltage level is output at a voltage greatly outside the range of approximately 15 V Since various switching elements (not shown) may be burned out in the circuit, it is necessary to control them. This is performed in the protection unit 420 described later. Meanwhile, diodes D11 and D21 and capacitors C11 and C21 for smoothing the output voltage may be provided at the output end of the transformer unit.

The output voltage detector 404 detects at least one output voltage among the plurality of output voltages and outputs a detection signal Sd to the voltage controller 406. In the figure, the first output voltage Vout1 is detected. The output voltage detector 404 may include a thyristor SCR1 and a port coupler PC1. The detected first output voltage Vout1 operates the thyristor SCR1 through the resistor R12, and the photocoupler PC1 is operated by the operation of the thyristor SCR1 and the first output voltage passing through the resistor R11. Then, the detection signal Sd is output to the voltage controller 406.

The voltage controller 406 receives the detection signal Sd and outputs a switching pulse signal Ssp and a driving voltage Vcc to the transformer 402. The voltage controller 406 may be implemented with a power IC as shown in the figure.

In detail, the voltage controller 406 receives the detection signal Sd from the output voltage detector 404 and pulse width modulation PWM, in which the pulse width is determined according to the signal level of the detection signal Sd. Signal), and outputs a switching pulse signal Ssp in which the switching operation is turned on when the pulse width modulation signal is high level and turned off when the pulse width modulation signal is high level.

When the voltage level of the first output voltage Vout1 is higher than an appropriate standard, a pulse width modulation PWM signal having a small duty is generated, and a switching pulse signal Ssp having a switching operation is output to output the voltage level of the first output voltage. When the voltage level of the first output voltage Vout1 is lower than an appropriate standard, a pulse width modulation PWM signal having a large duty is generated and a switching pulse signal Ssp in which a switching operation is performed is outputted. The voltage level of the first output voltage is compensated to be high, so that the first output voltage Vout1 having a constant voltage level is output.

On the other hand, the driving voltage Vcc is obtained by charging the resistor R2 and the capacitor C2 with the input voltage Vin at the initial driving of the voltage controller 406. The driving voltage Vcc drives the voltage control unit 406, that is, the power IC (POWER IC), and is also output to the transformer unit 402, through the transformer unit 402 as shown in the drawing, the third output voltage Vout3. Is output. As described above, if the third output voltage Vout3 is a switching voltage (about 15V, not shown) for driving various switching elements (not shown) in the driving apparatus, the range of the voltage level of the switching voltage should be within a predetermined range.

According to the display panel driving apparatus according to the present invention, it is possible to protect the driving apparatus including the power conversion circuit by cutting off the surge current flowing through the terminal of the power conversion circuit.

In addition, a power conversion circuit is provided in the driving device, and a stable level voltage can be supplied to the driving device through feedback control of the voltage level.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, this is merely exemplary, and those skilled in the art may realize various modifications and other equivalent embodiments therefrom. I can understand. Accordingly, the true scope of protection of the invention should be defined only by the appended claims.

Claims (10)

delete In the driving device of the display panel for applying a drive signal to the display panel to drive the display panel, A power conversion circuit for generating output voltages of a plurality of voltage levels used for the drive signal; The power conversion circuit includes a protection unit for detecting the abnormality of the power conversion circuit to control the operation of the power conversion circuit to protect the drive device, And a driving unit for blocking the current flow by detecting the surge current flowing through the terminal of the power conversion circuit. The method of claim 2, The protection unit is a display panel drive device made of a fusible resistor to block the flow of the surge current. The method of claim 2, The power conversion circuit, A transformer for outputting the plurality of output voltages by transforming an input voltage Vin; An output voltage detector for detecting at least one output voltage among the plurality of output voltages and outputting a detection signal; And And a voltage control unit configured to control the output voltage by outputting a switching pulse signal corresponding to the detection signal to the transformer unit. The method of claim 4, wherein And the transformer unit includes at least one transformer. The method of claim 4, wherein And the output voltage detector includes a photo coupler, detects the output voltage, and outputs the detection signal to the voltage controller through the photo coupler. The method of claim 4, wherein The voltage control unit is driven by the driving voltage Vcc received and accumulated in the input voltage Vin, and is output to the transformer unit so that the driving voltage is transformed. And a pulse width modulation (PWM) signal according to the detection signal, and outputs a switching pulse signal in which switching is performed by the pulse width modulation signal to the transformer. In the driving device of the display panel for applying a drive signal to the display panel to drive the display panel, And a power conversion circuit for generating an output voltage of a plurality of voltage levels used for the driving signal, detecting a surge current flowing in the circuit, and blocking a current flow. The method of claim 8, The power conversion circuit, A transformer for outputting the plurality of output voltages by transforming an input voltage Vin; An output voltage detector for detecting at least one output voltage among the plurality of output voltages and outputting a detection signal; A voltage controller configured to adjust the output voltage by outputting a switching pulse signal according to the detection signal to the transformer; And And a protection unit configured to sense a surge current flowing through a terminal of the power conversion circuit and to block current flow. The method of claim 9, The protection unit is a display panel drive device made of a fusible resistor to block the flow of the surge current.

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