KR100647685B1 - Apparatus of driving plasma display panel - Google Patents

Abstract

An object of the present invention is to provide a driving device of a display panel having a power supply unit and controlling an abnormal operation of the power supply unit.

In order to achieve the above object, the present invention provides a display panel driving apparatus for applying a driving signal to the display panel to drive the display panel,

A power supply for outputting a plurality of output voltages used for the drive signal; And

The present invention provides a display panel driving apparatus including a protection unit which detects an abnormality of the power supply unit and controls the operation of the power supply unit to protect the driving apparatus of the display panel.

Description

Apparatus of driving plasma 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 supply and a protection unit.

FIG. 6 is a block diagram schematically illustrating the protection unit of FIG. 5.

FIG. 7 is a circuit diagram illustrating the protection delay unit of FIG. 6.

FIG. 8 is a circuit diagram illustrating the driving voltage detector of FIG. 6.

9 is a circuit diagram illustrating the protection control unit of FIG. 6.

Explanation of symbols on the main parts of the drawings

Vin ... Input Voltage 400 ... Power Supply

402.Transformer 404.Output voltage detector

406 Voltage control section 420 Protection section

502 ... driving voltage detector 504 ... protecting delay unit

506 Sd ... detection signal

Ssp ... switching pulse signal Spc ... protection control signal

Spd ... Delayed signal Sco ... Comparison signal

V1 ... first voltage source

The present invention relates to a driving device for a display panel, and more particularly, to a driving device for a display panel having a power supply unit and controlling an abnormal operation of the power supply unit.

 In recent years, plasma display panels, which are attracting attention as large-sized flat panel display devices, have a discharge voltage applied after the discharge gas is filled between two substrates on which a plurality of electrodes are formed. Phosphor formed in the pattern of is excited to obtain a desired image.

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 these various levels of voltage to the driving device of the plasma display panel, a power supply unit was separately required. However, various voltages output from the power supply unit cause a voltage drop due to the length of the wirings between the power supply unit and the driving device, resulting in a voltage loss. In an effort to overcome this, efforts have been made to arrange a power supply unit in a driving device. However, when the power supply unit disposed in the driving device performs abnormal operation, there is a problem that the power supply unit disposed in each driving unit as well as the driving device are damaged because there is no protection.

The present invention has been made to solve various problems including the above problems, and an object of the present invention is to provide a driving apparatus of a display panel having a power supply unit and controlling an abnormal operation of the power supply unit.

In order to achieve the above object and various other objects, the present invention provides a display panel drive device for applying a drive signal to the display panel to drive the display panel,

A power supply for outputting a plurality of output voltages used for the drive signal; And

The present invention provides a display panel driving apparatus including a protection unit which detects an abnormality of the power supply unit and controls the operation of the power supply unit to protect the driving apparatus of the display panel.

According to another aspect of the present invention, the power supply unit, a transformer for outputting a plurality of output voltage by transforming the input voltage (Vin); An output voltage detector for detecting at least one output voltage among a plurality of output voltages and outputting a detection signal; And a voltage control unit for outputting a switching pulse signal according to the detection signal to the transformer unit to adjust the output voltage.

According to still another feature of the present invention, the transformer may include at least one transformer.

According to still another aspect of the present invention, it is preferable that the output voltage detector includes a photocoupler, detects the output voltage, and outputs a detection signal to the voltage controller through the photocoupler.

According to another aspect of the present invention, 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 unit so that the driving voltage is transformed, and the pulse according to the detection signal A PWM signal may be generated to output a switching pulse signal in which switching is performed by the pulse width modulation signal.

According to still another aspect of the present invention, the protection unit includes a driving voltage detection unit for detecting the driving voltage (Vcc) output to the transformer unit and outputs a comparison signal compared with a predetermined reference voltage; And a protection controller for receiving a comparison signal and outputting a protection control signal for controlling the switching of the voltage controller.

According to still another aspect of the present invention, the driving voltage detection unit includes: a first resistor and a second resistor connected in series to divide the driving voltage with voltage; And a comparator for comparing the voltage divided by the second resistor with a predetermined reference voltage,

When the voltage divided by the second resistor is smaller than the reference voltage, a low level comparison signal may be output. When the voltage divided by the second resistor is larger than the reference voltage, the high level comparison signal may be output.

According to another aspect of the present invention, the protection control unit, the thyristor operated according to the comparison signal; And a port coupler operated by the on operation of the thyristor to output a voltage control signal to the voltage controller.

When the high level comparison signal is input from the driving voltage, the thyristor and the port coupler may operate to output a low level control signal.

According to still another aspect of the present invention, the protection unit may further include a protection delay unit for outputting a delay signal to the protection control unit in consideration of the setup time of the driving voltage during initial driving of the voltage control unit.

According to another aspect of the present invention, the protection delay unit, the first voltage source for outputting a first voltage; A third resistor and a fourth resistor connected in series to voltage divide the first voltage; A first capacitor connected in parallel with the fourth resistor to slowly increase the voltage divided by the fourth resistor; And a comparator configured to output a delay signal by comparing the voltage divided by the fourth resistor with a predetermined reference voltage.

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

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, between the first substrate 100 and the second substrate 106 of the plasma display panel, the A electrodes (A1, ..., Am), the first and second dielectric layers (102, 110), Y electrodes Y1, ..., Yn, X electrodes X1, ..., Xn, phosphor layer 112, barrier rib 114 and magnesium monoxide (MgO) protective layer 104 are provided. .

The A electrodes A1, ..., Am are formed in a predetermined pattern on the second substrate 106 in the direction of the first substrate 100. The second dielectric layer 110 is applied to cover the A electrodes A1,..., Am. The partition walls 114 are formed on the second dielectric layer 110 in a direction parallel to the A electrodes A1,..., Am. The partition walls 114 function to partition the discharge region of each discharge cell and to prevent optical interference between the discharge cells. The phosphor layer 112 is applied on the second dielectric layer 110 on the A electrodes A1,..., Am between the partition walls 114, and sequentially a red light emitting phosphor layer, a green light emitting phosphor layer, A blue light emitting phosphor layer is disposed.

The X electrodes X1, ..., Xn and the Y electrodes Y1, ..., Yn are formed in the direction of the second substrate 106 to be orthogonal to the A electrodes A1, ..., Am. 1 is formed on the substrate 100 in a predetermined pattern. Each intersection sets a corresponding discharge cell. Each of the X electrodes (X1, ..., Xn) and each of the Y electrodes (Y1, ..., Yn) has conductivity with a transparent conductive material (Xna, Yna) made of a transparent conductive material such as indium tin oxide (ITO), etc. Metal electrodes (Xnb, Ynb) for increasing the ratio may be formed. The first dielectric layer 102 is formed by covering the X electrodes X1 to Xn and the Y electrodes Y1 to Yn. 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 (Y1, ..., Yn) and the X electrodes (X1, ..., Xn) are arranged in parallel side by side, the A electrodes (A1, ..., Am) ) Is disposed to intersect the Y electrodes Y1, ..., Yn and the X electrodes X1, ..., Xn, and the crossing region partitions the discharge cell Ce.

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 100, a logic controller 102, a Y driver 104, an address driver 106, an X driver 108 and a plasma display panel 1. Equipped. The image processor 100 converts an external image signal from the outside and outputs it as an internal image signal, and the logic controller 102 receives an internal image signal, respectively, an address driving control signal SA and a Y driving control signal SY. ) And the X driving control signal SX, and the Y driving unit 104, the address driving unit 106, and the X driving unit 108 receive the driving control signals, respectively, and the Y electrodes of the plasma display panel 1, A A driving signal is output to each of the 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 Y1, ..., Yn, and a falling pulse is applied to the X electrodes X1, ..., Xn. From the second voltage (bias voltage) is applied to perform a reset discharge. All discharge cells are initialized by reset discharge. The rising pulse rises from the sustain discharge voltage (Vs) by the rising voltage (Vset) and finally reaches the rising maximum voltage (Vset + Vs), and the falling pulse falls from the sustain discharge voltage (Vs) and finally the falling minimum voltage ( Vnf).

In the address period PA, scanning pulses are sequentially applied to the Y electrodes Y1, ..., and Yn, and display data signals are applied to the A electrodes A1, ..., Am in accordance with the scanning pulses. Address discharge is then performed. 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, sustain pulses are alternately applied to the X electrodes X1, ..., Xn and the Y electrodes Y1, ..., Yn to perform 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 supply and a protection unit.

Referring to the drawings, the driving device of the present invention includes a power supply unit 400 and the protection unit 420. 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 supply unit 400 outputs a plurality of output voltages used for the driving signal, and the protection unit 420 detects the presence or absence of abnormality among the plurality of output voltages output from the power supply unit 400, and detects the abnormality. 400 to control the operation of the driving device.

First, the power supply unit 400 includes a transformer 402, an output voltage detector 404, and a voltage controller 406. The transformer 402 receives the input voltage Vin 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 supply unit 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. 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 reference level, a pulse width modulation PWM signal having a small duty is generated, and a switching pulse signal Ssp in which a switching operation is performed 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. When the switching voltage is out of a certain range, it is necessary to protect the driving device of the display panel. This is performed to the protection unit 420 to be described later.

FIG. 6 is a block diagram briefly illustrating a protection unit of FIG. 5, FIG. 7 is a circuit diagram illustrating a protection delay unit of FIG. 6, FIG. 8 is a circuit diagram illustrating a driving voltage detector of FIG. 6, and FIG. 9 is of FIG. 6. It is a circuit diagram which shows a protection control part.

5 to 9, the protection unit 420 is output from the voltage control unit 406 to the transformer 402 so that the third output voltage Vout3, that is, the aforementioned switching voltage is within a predetermined range. The driving voltage detector 502 detects the input driving voltage Vcc and compares the predetermined reference voltage to output the comparison signal Sco, and controls the switching of the voltage controller 406 by receiving the comparison signal Sco. A protection control unit 506 for outputting a protection control signal Spc to the voltage control unit 406. Also, the protection unit 420 may include a delay signal Spd so that the protection unit 420 does not operate during the setup time in consideration of the setup time of the driving voltage Vcc during the initial driving of the voltage control unit 406. A protection delay unit 504 outputting to 506 may be further provided. Assuming that the proper range of the driving voltage Vcc is between 10V and 15V, when the driving voltage Vcc is 10V or less, the protection unit 420 operates to output the protection control signal 506 to the voltage controller 406. To prevent the switching operation from being performed in the voltage controller 406.

As shown in FIG. 7, the protection delay unit 504 includes a first voltage source V1 for outputting a first voltage (for example, 5V), a third resistor R3 and a third resistor connected in series to voltage-dividing the first voltage. A fourth capacitor R1 is connected to the fourth resistor R4 in parallel, and the first capacitor C1 gradually increases by delaying a voltage distributed to the fourth resistor R4. Once the first voltage 5V is output from the first voltage source V1, the third resistor R3 and the fourth resistor R4 are connected in series to distribute the first voltage across the fourth resistor R4. The voltage gradually increases to the voltage divided by the fourth resistor R4 and the first capacitor C1. Rise time is determined by the time constant by the fourth resistor (R4) and the first capacitor (C1). The voltage distributed across the fourth resistor gradually rises and is input to one terminal of the comparator 602, and the other terminal of the comparator 602 is a reference determined by the first voltage source V1 and two resistors RC1 and RC2. Voltage (Vref, 2.5V) is input. The comparator 602 compares this and outputs a delay signal Spd to the protection controller 506 when the voltage divided across the fourth resistor is smaller than the reference voltage Vref, 2.5V, thereby preventing the protection controller 506 from operating. Do not When the voltage distributed across the fourth resistor gradually rises to be greater than the reference voltage Vref and 2.5V, the delay signal Spd is no longer output to the protection controller 506. Specifically, the period in which the voltage divided across the fourth resistor is smaller than the reference voltage by adjusting the values of the fourth resistor R4 and the first capacitor C1 is designed to match the setup time of the driving voltage Vcc. do. As a result, the delay signal Spd is output from the protection delay unit 504 during the period in which the driving voltage Vcc is set up during the initial driving of the voltage control unit 406 so that the protection control unit 506 does not operate.

As illustrated in FIG. 8, the driving voltage detector 502 distributes the first resistor R1 and the second resistor R2 and the second resistor R2 connected in series to each other to divide the driving voltage Vcc into voltage. And a comparator 702 comparing the predetermined voltage with a predetermined reference voltage Vref. The reference voltage Vref is determined using the first voltage source V1 and two resistors RC3 and RC4. It is input to one terminal of the comparator 702. The voltage divided by the second resistor R2 is input to the other terminal of the comparator 702. For example, the appropriate range of the driving voltage (Vcc) is 10V to 15V, the resistance ratio of the first resistor (R1) and the second resistor (R2) is 3: 1, the first voltage (V1) is 5V, the reference If the voltage Vref is set at 2.5V, the voltage divided by the second resistor R2 is between 2.5V and 3.75V when the driving voltage Vcc is in the proper range between 10V and 15V. Since it is higher than 2.5V, which is Vref, the comparator 702 outputs a high level comparison signal Sco. On the other hand, if the driving voltage (Vcc) is less than 10V, the voltage divided by the second resistor (R2) is determined to be less than 2.5V, which is lower than the reference voltage (Vref) 2.5V, so that the low level of the comparator 702 The comparison signal Sco is output.

As shown in FIG. 9, the protection controller 506 is operated by an on operation of the thyristor SCR2 and the thyristor SCR2 operated according to the comparison signal Sco, thereby protecting the voltage controller 406. A port coupler PC2 for outputting a control signal Spc is provided.

First, since the delay signal Spd is input from the protection delay unit 504 during the initial driving of the voltage control unit 406, that is, during the setup time of the driving voltage Vcc, the protection control unit 506 does not operate. After the setup time of the driving voltage Vcc, the comparison signal Sco is input from the driving voltage detector 502, and the protection controller 506 operates according to the signal level of the comparison signal Sco. When the low level comparison signal Sco is input to the protection control unit 506, the thyristor SCR2 does not operate, and as a result, the protection control unit 506 does not operate. When the high level comparison signal Sco is input to the protection controller 506, the thyristor SCR2 is turned on through the resistor R13 and the diode D13, and the resistor R14 is applied to the first voltage source V1. The current flowing through the current flows through the photodiode of the porter coupler PC2 to emit light, and the phototransistor of the photocoupler PC2 receives the light and passes through the resistor R15 to generate a low level protection control signal Spc. It is output to 406. When the low level protection control signal Spc is input to the voltage controller 406, the voltage controller 406 does not perform a switching operation, and the switching pulse signal Ssp is no longer output to the transformer 402. In the power supply unit 400, output voltages Vout1 to Vout4 are not output. As described above, the protection unit 420 detects the driving voltage Vcc and determines whether there is an abnormality. If the voltage level of the driving voltage Vcc does not fall within an appropriate range, the power supply unit 400 outputs the output voltages Vout1 to Vout4. By preventing the output, the driving device including the power supply unit 400 and the protection unit 420 is protected.

According to the present invention as described above, the following effects can be obtained.

First, unlike the related art, the power supply unit is provided in the driving device, thereby reducing the voltage drop caused by the wiring.

Second, by providing a protection unit for controlling the abnormal operation of the power supply unit provided in the drive device, it is possible to protect the drive device to ensure the stability of the drive device.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (10)

In the driving device of the display panel for applying a drive signal to the display panel to drive the display panel, A power supply unit for outputting a plurality of output voltages used for the driving signal; And A protection unit that detects an abnormality of the power supply unit and controls the operation of the power supply unit to protect the driving device of the display panel; The power supply unit transforms an input voltage Vin to output a 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 which outputs a switching pulse signal according to the detection signal to the transformer to adjust the output voltage. delete The method of claim 1, wherein the transformer unit, At least one transformer comprising a drive device for a display panel. The method of claim 1, wherein the output voltage detector, And a photo coupler for detecting the output voltage and outputting the detection signal to the voltage controller through the photo coupler. The method of claim 1, wherein the voltage control unit, It is driven by the driving voltage (Vcc) accumulated by receiving the input voltage (Vin), and outputs to the transformer unit so that the driving voltage is transformed, And generating a pulse width modulation (PWM) signal according to the detection signal, and outputting a switching pulse signal in which switching is performed by the pulse width modulation signal. The method of claim 5, wherein the protection unit, A driving voltage detector for detecting the driving voltage Vcc output to the transformer unit and comparing a predetermined reference voltage to output a comparison signal; And And a protection control unit for receiving the comparison signal and outputting a protection control signal for controlling switching of the voltage control unit to the voltage control unit. The method of claim 6, wherein the driving voltage detector A first resistor and a second resistor connected in series to voltage divide the drive voltage; And Comparators for comparing the voltage divided by the second resistor and a predetermined reference voltage, A low level comparison signal is output when the voltage divided by the second resistor is smaller than the reference voltage; and a high level comparison signal is output when the voltage divided by the second resistor is larger than the reference voltage. Drive of the panel. The method of claim 6, wherein the protection control unit, A thyristor operated according to the comparison signal; And A port coupler operated by an on operation of the thyristor and outputting a voltage control signal to the voltage controller; And when the high level comparison signal is input from the driving voltage, the thyristor and the port coupler operate to output a low level control signal. The method of claim 6, wherein the protection unit, And a protection delay unit for outputting a delay signal to the protection control unit in consideration of the setup time of the driving voltage during initial driving of the voltage control unit. The method of claim 9, wherein the protective delay unit, A first voltage source for outputting a first voltage; A third resistor and a fourth resistor connected in series to voltage divide the first voltage; A first capacitor connected in parallel to the fourth resistor and gradually increasing the voltage distributed by the fourth resistor; And And a comparator for outputting a delay signal by comparing the voltage divided by the fourth resistor with a predetermined reference voltage.

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