KR20080001874A - Plasma display apparatus - Google Patents

Abstract

A plasma display apparatus is provided to prevent the electrical damage of switching elements by blocking the supplement of driving voltage when the driving voltage for driving the switching elements is below a predetermined threshold voltage. A plasma display apparatus includes a plasma display panel and a driver. The plasma display panel include electrodes. The driver includes a threshold voltage generator(710), a voltage comparator(720), and a voltage blocking unit(730). The threshold voltage generator generates a threshold voltage using a higher voltage than driving voltages. The voltage comparator compares threshold and driving voltages. The voltage blocking unit blocks the supplement of the driving voltage when the driving voltage is below a threshold voltage based on the comparison result of the voltage comparator.

Description

Plasma Display Apparatus {Plasma Display Apparatus}

BRIEF DESCRIPTION OF DRAWINGS Fig. 1 is a diagram for explaining the configuration of a plasma display device of the present invention.

2A to 2B are views for explaining an example of the structure of a plasma display panel included in the plasma display device of the present invention.

FIG. 3 is a diagram for explaining a frame for implementing grayscale of an image in the plasma display device of the present invention; FIG.

4 is a view for explaining an example of the operation of the plasma display device of the present invention;

5A to 5B are diagrams for explaining another form of the rising ramp signal or the second falling ramp signal.

Fig. 6 is a diagram for explaining another type of the sustain signal.

7 is a view for explaining an example of the configuration of a driving unit for cutting off the supply of the driving voltage when the driving voltage for driving the switching elements is unstable.

8A to 8C are views for explaining the operation of the driving unit of FIG. 7 in more detail.

9 is a view for explaining another example of the configuration of a driving unit for cutting off the supply of the driving voltage when the driving voltage for driving the switching elements is unstable.

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

100: plasma display panel 110: driver

The present invention relates to a plasma display device (Plasma Display Apparatus).

The plasma display apparatus includes a plasma display panel having electrodes formed thereon, and a driver for applying a predetermined driving signal to the electrodes of the plasma display panel.

In general, a phosphor layer is formed in a discharge cell (Cell) partitioned by a partition, and a plurality of electrodes are formed in the plasma display panel.

The driving unit applies a driving signal to the discharge cell through the electrode.

Then, the discharge is generated by the drive signal supplied in the discharge cell. Here, when discharged by a drive signal in the discharge cell, the discharge gas filled in the discharge cell generates vacuum ultraviolet rays, and the vacuum ultraviolet light emits the phosphor formed in the discharge cell to emit visible light. Generate. The visible light displays an image on the screen of the plasma display panel.

In the plasma display device, the driving unit includes one or more switching elements. When the driving voltage for driving such a switching element becomes unstable, a problem arises in that the switching elements are electrically damaged.

SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a plasma display apparatus capable of preventing electrical damage to switching elements even when a driving voltage for driving the switching elements becomes unstable.

Plasma display device of the present invention for achieving the above object includes a plasma display panel having an electrode, a driving unit for applying a driving signal to the electrode, the driving unit includes a switching element for performing a switching (switching) operation, switching It is characterized in that the supply of the driving voltage is cut off when the driving voltage for driving the element is less than or equal to a predetermined threshold voltage.

The driving unit may be driven when the threshold voltage generator generates a threshold voltage using another voltage higher than the driving voltage, and the driving voltage is less than or equal to the threshold voltage as a result of the comparison between the threshold voltage and the voltage comparator and the voltage comparator. It characterized in that it comprises a voltage interrupter for interrupting the supply of voltage.

In addition, the threshold voltage generating unit may divide the other voltage to generate a threshold voltage.

In addition, the threshold voltage is characterized in that 3V or more and less than 5V, more preferably the threshold voltage is 4V or more and 4.5V or less.

Hereinafter, a plasma display device of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view for explaining the configuration of the plasma display device of the present invention.

Referring to FIG. 1, the plasma display apparatus of the present invention includes a plasma display panel 100 and a driver 110.

The driver 110 includes a switching element that applies a driving signal to an electrode formed in the plasma display panel 100 and performs a switching operation, and a driving voltage for driving the switching element is higher than a predetermined threshold voltage. If it is low, the supply of the driving voltage is cut off.

Here, in FIG. 1, only the case in which the driving unit 110 is formed in one board form is illustrated, but in the present invention, the driving unit 110 is divided into a plurality of board forms according to electrodes formed on the plasma display panel 100. It is also possible to lose.

For example, the driver 110 of the plasma display device of the present invention includes a scan driver (not shown) for driving the scan electrode (Y), a sustain driver (not shown) for driving the sustain electrode (Z), and an address electrode. It can be divided into a data driver (not shown) for driving (X).

The driving unit 110 of the plasma display device of the present invention will be more clearly described later.

In particular, in the case where the driving voltage for driving the switching element in the driving unit 110 is less than or equal to a predetermined threshold voltage, the supply of the driving voltage will be described in detail later with reference to FIG.

In the plasma display panel 100, scan electrodes Y parallel to each other and sustain electrodes Z parallel to each other are formed, and address electrodes X intersecting the scan electrodes Y and the sustain electrodes Z are preferably formed. Do.

An example of the structure of the plasma display panel 100 will be described in detail with reference to FIGS. 2A to 2B.

2A to 2B are views for explaining an example of the structure of the plasma display panel included in the plasma display device of the present invention.

First, referring to FIG. 2A, a plasma display panel according to the present invention includes a front panel 201 including an electrode, preferably a front substrate 201 on which scan electrodes 202 and Y and sustain electrodes 203 and Z are formed. A rear panel including a back substrate 211 on which an electrode intersecting the scan electrodes 202 and Y and the sustain electrodes 203 and Z, preferably the address electrodes 213 and X, are formed. 210 may be bonded to each other.

Here, the electrodes formed on the front substrate 201, preferably the scan electrodes 202 and Y and the sustain electrodes 203 and Z, generate a discharge in a discharge space, that is, a discharge cell, and at the same time Discharge can be maintained.

The dielectric layer, preferably on top of the front substrate 201 on which the scan electrodes 202 and Y and the sustain electrodes 203 and Z are formed, covers the scan electrodes 202 and Y and the sustain electrodes 203 and Z. Top dielectric layer 204 may be formed.

This upper dielectric layer 204 limits the discharge current of the scan electrodes 202 and Y and the sustain electrodes 203 and Z and can insulate between the scan electrodes 202 and Y and the sustain electrodes 203 and Z. have.

A protective layer 205 is formed on the top surface of the upper dielectric layer 204 to facilitate discharge conditions. The protective layer 205 may be formed through a method of depositing a material such as magnesium oxide (MgO) on the upper dielectric layer 204.

Meanwhile, the electrodes formed on the rear substrate 211, preferably the address electrodes 213 and X, are electrodes that apply a data signal to the discharge cells.

A dielectric layer, preferably a lower dielectric layer 215 may be formed on the rear substrate 211 on which the address electrodes 213 and X are formed to cover the address electrodes 213 and X.

The lower dielectric layer 215 may insulate the address electrodes 213 and X.

On top of the lower dielectric layer 215, a partition 212, such as a stripe type, a well type, a delta type, a honeycomb type, for partitioning a discharge cell, that is, a discharge cell, is formed. Is formed. Accordingly, discharge cells such as red (R), green (G), and blue (B) may be formed between the front substrate 201 and the rear substrate 211.

Here, it is preferable that a predetermined discharge gas is filled in the discharge cells partitioned by the partition walls 212.

In addition, a phosphor layer 214 that emits visible light for image display may be formed in the discharge cells partitioned by the partition wall 212. For example, red (R), green (G), and blue (B) phosphor layers may be formed.

In the plasma display panel of the present invention described above, when the driving signal is supplied to at least one of the scan electrodes 202, Y, the sustain electrodes 203, Z, and the address electrodes 213, X, the barrier rib 212 is provided. Discharge may occur within the partitioned discharge cell.

Then, vacuum ultraviolet rays are generated in the discharge gas filled in the discharge cells, and the vacuum ultraviolet rays are applied to the phosphor layer 214 formed in the discharge cells. Then, a predetermined visible light is generated in the phosphor layer 214, and the visible light is emitted to the outside through the front substrate 201 in which the upper dielectric layer 204 is formed. A predetermined image may be displayed on the outer surface.

Meanwhile, in the description of FIG. 2A, only the case where the scan electrodes 202 and Y and the sustain electrodes 203 and Z are each formed of one layer is illustrated and described. However, the scan electrodes 202 and Y or the It is also possible that at least one of the sustain electrodes 203 and Z consists of a plurality of layers. This will be described with reference to FIG. 2B.

Referring to FIG. 2B, the scan electrodes 202 and Y and the sustain electrodes 203 and Z may be formed of two layers, respectively.

In particular, in consideration of light transmittance and electrical conductivity, the scan electrodes 202 and Y and the sustain electrodes 203 and Z are opaque silver (Ag) to emit light generated in the discharge cell to the outside and to secure driving efficiency. Bus electrodes 202b and 203b and transparent electrodes 202a and 203a made of transparent indium tin oxide (ITO).

As such, the reason why the scan electrodes 202 and Y and the sustain electrodes 203 and Z include the transparent electrodes 202a and 203a is that when visible light generated in the discharge cells is emitted to the outside of the plasma display panel. To be released effectively.

In addition, the reason why the scan electrodes 202 and Y and the sustain electrodes 203 and Z include the bus electrodes 202b and 203b is that the scan electrodes 202 and Y and the sustain electrodes 203 and Z are transparent electrodes. In the case of including only 202a and 203a, the driving efficiency can be reduced because the electrical conductivity of the transparent electrodes 202a and 203a is relatively low, so that the transparent electrodes 202a and 203a can cause such a reduction in the driving efficiency. To compensate for the low electrical conductivity.

As described above, in the case where the scan electrodes 202 and Y and the sustain electrodes 203 and Z include the bus electrodes 202b and 203b, the transparent electrodes (202b and 203b) prevent the reflection of external light by the bus electrodes 202b and 203b. Black layers 220 and 221 may be further provided between the 202a and 203a and the bus electrodes 202b and 203b.

Meanwhile, the transparent electrodes 202a and 203a may be omitted in the same structure as in FIG. 2B. In other words, ITO-Less is also possible.

For example, the scan electrodes 202 and Y and the sustain electrodes 203 and Z may be made of only the bus electrodes 202b and 203b without the transparent electrodes 202a and 203a in FIG. 2B. That is, the scan electrodes 202 and Y and the sustain electrodes 203 and Z may be formed of one layer of the bus electrodes 202b and 203b.

2A to 2B, only one example of the plasma display panel of the present invention is shown and described, and it is to be understood that the present invention is not limited to the plasma display panel having the structure as shown in FIGS. 2A to 2B. For example, the plasma display panel of FIGS. 2A to 2B shows only the case where the upper dielectric layer 204 and the lower dielectric layer 215 are each one layer, but the upper dielectric layer 204 and At least one or more of the lower dielectric layers 215 may be formed of a plurality of layers.

In addition, a black layer (not shown) may be further formed on the top of the partition 212 to prevent reflection of the external light due to the partition 212.

As such, the structure of the plasma display panel applied to the plasma display apparatus of the present invention may be variously changed.

An example of the operation of the plasma display apparatus of the present invention including the plasma display panel will be described with reference to FIGS. 3 to 4.

3 to 4, only the case where the driving voltage for driving the switching elements included in the driving unit is stable, that is, higher than the preset threshold voltage will be described as an example.

On the other hand, when the driving voltage for driving the switching elements is undefined, i.e., below the predetermined threshold voltage will be described in more detail later.

FIG. 3 is a diagram for explaining a frame for implementing gray levels of an image in the plasma display apparatus of the present invention.

4 is a view for explaining an example of the operation of the plasma display device of the present invention.

First, referring to FIG. 3, in the plasma display device of the present invention, a frame for implementing gray levels of an image is divided into several subfields having different emission counts.

In addition, although not shown, each subfield may further include a reset period for initializing all discharge cells, an address period for selecting discharge cells to be discharged, and a sustain period for implementing gray levels according to the number of discharges. Sustain Period).

For example, when displaying an image with 256 gray levels, a frame period (16.67 ms) corresponding to 1/60 second is divided into eight subfields SF1 to SF8 as shown in FIG. Each of the subfields SF1 to SF8 is divided into a reset period, an address period, and a sustain period.

The gray scale weight of the corresponding subfield may be set by adjusting the number of the sustain signals supplied in the sustain period. That is, a predetermined gray scale weight can be given to each subfield using the sustain period. For example, the gray scale weight of each subfield is 2 ⁿ by setting the gray scale weight of the first subfield to 2 ⁰ and the gray scale weight of the second subfield to 2 ¹ (where n = 0, 1). , 2, 3, 4, 5, 6, and 7) to increase the gray scale weight of each subfield. As described above, the number of sustain signals supplied in the sustain period of each subfield is adjusted according to the gray scale weight in each subfield, thereby implementing gray levels of various images.

The plasma display device of the present invention uses a plurality of frames to display an image of one second. For example, 60 frames are used to display an image of 1 second.

In FIG. 3, only one frame is composed of eight subfields. However, the number of subfields forming one frame may be changed in various ways. For example, one frame may be configured with 12 subfields from the first subfield to the twelfth subfield, or one frame may be configured with 10 subfields.

The image quality of the image implemented by the plasma display apparatus implementing the gray level of the image using the frame may be determined according to the number of subfields included in the frame. That is, when 12 subfields are included in a frame, gray levels of 2 ¹² images can be expressed, and when 8 subfields are included in a frame, gray levels of 2 ⁸ images can be realized. .

Also, in FIG. 3, subfields are arranged according to the order of increasing the magnitude of gray scale weight in one frame. Alternatively, subfields may be arranged in the order of decreasing gray scale weight in one frame. Subfields may be arranged regardless of the weight.

Next, referring to FIG. 4, an example of an operation of the plasma display apparatus of the present invention in any one of a plurality of subfields included in the same frame as in FIG. 3 is shown.

First, the driving unit 110 of FIG. 1 may apply a first ramp-down signal to the scan electrode Y in a pre-reset period before the reset period.

In addition, while the first falling ramp signal is applied to the scan electrode Y, the driving unit 110 may apply a pre-sustain signal in a direction opposite to the first falling ramp signal to the sustain electrode Z.

Here, it is preferable that the first falling ramp signal applied to the scan electrode Y gradually descends to the tenth voltage V10. More preferably, the first falling ramp signal falls gradually from the voltage of the ground level GND.

In addition, it is preferable that the pre-sustain signal maintain the pre-sustain voltage Vpz substantially constant. Here, it is preferable that the pre-sustain voltage Vpz is approximately equal to the voltage of the sustain signal SUS applied in the subsequent sustain period, that is, the sustain voltage Vs.

As such, when the first falling ramp signal is applied to the scan electrode Y in the pre-reset period and the pre-sustain signal is applied to the sustain electrode Z together, the wall charge Wall having a predetermined polarity on the scan electrode Y is walled. Charge) is accumulated, and wall charges of opposite polarity to the scan electrode (Y) are accumulated on the sustain electrode (Z). For example, positive wall charges are accumulated on the scan electrode Y, and negative wall charges are accumulated on the sustain electrode Z.

This makes it possible to generate a set-up discharge of sufficient intensity in the subsequent reset period, which in turn makes it possible to perform the initialization sufficiently stably.

Even when the amount of wall charges in the discharge cell is insufficient, a setup discharge of sufficient intensity can be generated.

In addition, even when the voltage of the rising ramp signal Ramp-Up applied to the scan electrode Y becomes smaller in the reset period, setup discharge of sufficient intensity can be generated.

The pre-reset period described above may be included before the reset period in all subfields of the frame.

Alternatively, a pre-reset period is included before the reset period in one subfield having the smallest gray scale weight among the subfields of the frame from the viewpoint of securing the driving time, or a reset period in two or three subfields of the subfields of the frame. It is also possible to include a pre-reset period before.

Alternatively, this pre-reset period may be omitted in all subfields.

After the pre-reset period, in the set-up period of the reset period for initialization, the driving unit 110 applies a ramp-up signal in a direction opposite to the first falling ramp signal to the scan electrode Y. do.

Here, the rising ramp signal may include a first rising ramp signal gradually increasing with a first slope from the twentieth voltage V20 to the thirtieth voltage V30 and the second rising ramp signal from the thirtieth voltage V30 to the forty-th voltage V40. It may include a second rising ramp signal rising to the slope.

In this setup period, a weak dark discharge, that is, setup discharge, occurs in the discharge cell by the rising ramp signal. This setup discharge causes a certain amount of wall charges to accumulate in the discharge cell.

Here, it is preferable that the second slope of the second rising ramp signal is gentler than the first slope. As such, when the second slope is made gentler than the first slope, the voltage is increased relatively quickly until the setup discharge occurs, and the voltage is increased relatively slowly while the setup discharge occurs. The amount of light generated by the setup discharge can be reduced.

Accordingly, the contrast characteristic can be improved.

In the set-down period after the set-up period, the driver 110 may apply a second ramp-down signal in the opposite polarity direction to the scan electrode Y after the ramp ramp signal. Can be.

Here, it is preferable that the second falling ramp signal gradually decreases from the twentieth voltage V20 to the fifty voltage V50.

As a result, weak erase discharge, that is, set-down discharge, occurs in the discharge cell. By this set-down discharge, wall charges such that address discharge can be stably generated in the discharge cells remain uniformly.

Meanwhile, unlike FIG. 4, the rising ramp signal or the second falling ramp signal may be set, which will be described below with reference to FIGS. 5A to 5B.

5A to 5B are diagrams for explaining another form of the rising ramp signal or the second falling ramp signal.

First, referring to FIG. 5A, the rising ramp signal gradually increases from the thirtieth voltage V30 to the forty-th voltage V40 after rapidly rising to the thirtieth voltage V30.

As such, the rising ramp signal may rise gradually with different inclinations over two stages, as shown in FIG. 4, and in various forms, such as gradually rising in one stage as shown here in FIG. 5A. It is possible to change.

Next, referring to FIG. 5B, the second falling ramp signal has a form in which the voltage gradually decreases from the thirtieth voltage V30.

As described above, the second falling ramp signal may be changed in various forms, such as a different point in time at which the voltage falls.

This concludes the description of FIGS. 5A to 5B.

Meanwhile, in the address period after the reset period, the driver 110 may apply a scan bias signal to the scan electrode Y that substantially maintains a voltage higher than the 50 th voltage V50 of the second falling ramp signal.

In addition, the scan signal Scan, which decreases from the scan bias signal by the scan voltage ΔVy, may be applied to all the scan electrodes Y1 to Yn.

For example, the first scan signal Scan 1 is applied to the first scan electrode Y1 among the plurality of scan electrodes Y, and then the second scan signal Scan 2 is applied to the second scan electrode Y2. Is applied, and an n-th scan signal Scan n is applied to the n-th scan electrode Yn.

As such, when the scan signal Scan is applied to the scan electrode Y, a data signal rising by the magnitude ΔVd of the data voltage may be applied to the address electrode X.

As the scan signal Scan and the data signal Data are applied, the voltage difference between the voltage of the scan signal and the data voltage Vd of the data signal and the wall voltage due to the wall charges generated in the reset period In addition, address discharge is generated in the discharge cells to which the voltage Vd of the data signal is applied.

In this discharge cell selected by the address discharge, wall charges such that sustain discharge can occur when the sustain signal SUS is applied in a subsequent sustain period are formed.

Here, the driving unit 110 preferably applies a sustain bias signal to the sustain electrode Z in order to prevent the address discharge from becoming unstable due to the interference of the sustain electrode Z in the address period.

Here, it is preferable that the sustain bias signal maintain a substantially constant sustain bias voltage Vz smaller than the voltage of the sustain signal applied in the sustain period and larger than the voltage of the ground level GND.

Thereafter, the driver 110 may apply the sustain signal SUS to at least one of the scan electrode Y and the sustain electrode Z in the sustain period for displaying an image. For example, the sustain signal SUS is applied to the scan electrode Y and the sustain electrode Z alternately. The sustain signal SUS preferably has a magnitude of a voltage of ΔVs.

When the sustain signal SUS is applied, the discharge cell selected by the address discharge is added with the wall voltage in the discharge cell and the sustain voltage Vs of the sustain signal SUS and the scan electrode SUS is applied when the sustain signal SUS is applied. A sustain discharge, that is, a display discharge, occurs between Y) and the sustain electrode Z. Accordingly, a predetermined image is implemented on the plasma display panel.

It is also possible to apply a sustain signal in a different type from this FIG. 4. This will be described with reference to FIG. 6 attached thereto.

6 is a diagram for explaining another type of the sustain signal.

Referring to FIG. 6, a positive sustain signal and a negative sustain signal are alternately applied to any one of the scan electrode Y and the sustain electrode Z, for example, the scan electrode.

As described above, while the positive sustain signal and the negative sustain signal are applied to any one electrode, a bias signal is preferably applied to the other electrode, for example, the sustain electrode Z.

Here, the bias signal preferably maintains the voltage at the ground level GND substantially constant.

As such, the shape of the sustain signal SUS may be variously changed.

As such, when the sustain signal is applied to only one of the scan electrode Y and the sustain electrode Z and the bias signal is applied to the other electrode in the sustain period, the shape of the driving unit can be simplified.

For example, when a sustain signal is applied to the scan electrode Y, and a sustain signal is also applied to the sustain electrode Z, a driving board on which circuits for applying the sustain signal to the scan electrode Y are arranged And driving boards on which circuits for applying a sustain signal to the sustain electrode Z are arranged.

On the other hand, when the sustain signal is applied to only one of the scan electrode (Y) and the sustain electrode (Z) as in the present invention, the sustain is applied to any one of the scan electrode (Y) or the sustain electrode (Z). Only one driving board on which circuits for applying a signal are arranged is required.

As a result, the overall size of the driving unit can be reduced, thereby reducing the manufacturing cost.

In the above, the case where the driving voltage for driving the switching elements is stable, that is, the driving voltage is larger than the predetermined threshold voltage has been mainly described. Hereinafter, the case where the driving voltage is unstable, that is, the case where the driving voltage is below a preset threshold will be mainly described.

7 is a view for explaining an example of the configuration of a driving unit for cutting off the supply of the driving voltage when the driving voltage for driving the switching elements is unstable.

Referring to FIG. 7, the driving unit according to the present invention includes a switching element that performs a switching operation, and the driving voltage Vcc of the driving voltage Vcc driving the switching element is less than or equal to a preset threshold voltage. To cut off the supply, it is preferable to include a threshold voltage generator 710, a voltage comparator 720, and a voltage breaker 730.

Here, the threshold voltage generator 710 generates the threshold voltage using another voltage Vd higher than the driving voltage Vcc for driving the switching elements.

In addition, the threshold voltage generator 710 preferably divides the other voltage Vd described above to generate a threshold voltage.

As such, the threshold voltage generator 710 preferably includes a first resistor portion R1 and a second resistor portion R2 in order to generate a threshold voltage using voltage division.

Here, the other voltage for generating the threshold voltage is preferably the voltage Vd of the data signal Data as shown in FIG. 4 or the voltage Vs of the sustain signal SUS. Here, considering that the voltage Vd of the data signal is relatively smaller than the voltage Vs of the sustain signal, voltage division is easier, so that another voltage for generating the threshold voltage is shown in FIG. It is preferable that it is the voltage Vd of a signal.

The voltage comparator 720 compares the threshold voltage generated by the threshold voltage generator 710 with the driving voltage Vcc.

The voltage blocking unit 730 cuts off the supply of the driving voltage Vcc when the driving voltage Vcc is less than or equal to the threshold voltage as a result of the comparison of the voltage comparing unit 720. As such, when the driving voltage Vcc is less than or equal to the threshold voltage, the voltage blocking unit 730 may include a voltage blocking switch unit S10 to cut off the supply of the driving voltage Vcc.

Here, the threshold voltage is preferably 3V or more and less than 5V. In addition, the threshold voltage is more preferably 4V or more and 4.5V or less. The reason why the threshold voltage is set to 3V or more and 5V or less, more preferably 4V or more and 4.5V or less is because the threshold voltage is set to 4V or more and 4.5V because most switching elements operate substantially at voltages of 4V or more and 4.5V or less. This is because most of the switching elements can be stably operated by setting the following.

For example, another voltage Vd for generating the threshold voltage is 60V, and among the switching elements included in the driving unit according to the present invention, A switching element is turned off when a driving voltage of 4V or less is supplied, and B Assume that the switching element is turned off when a driving voltage of 3V or less is supplied.

In addition, it is assumed that the resistance value of the first resistor portion R1 is 14Ω (ohm), and the resistance value of the second resistor portion R2 is 1Ω (ohm). The threshold voltage is then 1/15 x 60 = 4V.

In this case, when the driving voltage Vcc is stabilized to 5V, the voltage comparing unit 720 compares the driving voltage Vcc of 5V and the threshold voltage of 4V and confirms that the driving voltage Vcc is higher than the threshold voltage. .

Then, the voltage blocking unit 730 supplies the driving voltage Vcc as a control signal of the switching element by closing the voltage blocking switch unit S10.

On the other hand, when the driving voltage Vcc becomes unstable to 3.5V, the voltage comparing unit 720 compares the driving voltage Vcc of 3.5V and the threshold voltage of 4V so that the driving voltage Vcc is larger than the threshold voltage. Check low.

Then, the voltage blocking unit 730 opens the voltage blocking switch unit S10 and cuts off the supply of the driving voltage Vcc. Then, the control signal to which the driving voltage Vcc is cut off is applied to the switching element.

On the other hand, when the driving voltage Vcc becomes unstable and becomes 3.5V, if the unstable driving voltage Vcc is supplied without being cut off, the A switching element that is turned off at 4V or less operates normally, while it is turned off at 3V or less. The B switching element is turned off.

As a result, most of the current flows through the normally operating A switching device, thereby causing the A switching device to be electrically damaged.

As a result, if the driving voltage is normally supplied when the driving voltage Vcc is unstable, it may cause electrical damage to the switching device. When the supply of the driving voltage Vcc is cut off as in the present invention, The electrical damage can be prevented.

The operation of the driving unit of FIG. 7 will be described in more detail with reference to FIGS. 8A to 8C.

8A to 8C are views for explaining the operation of the driving unit of FIG. 7 in more detail.

8A to 8C, a circuit configuration for applying a sustain signal will be described as an example.

First, referring to FIG. 8A, a circuit configuration for applying a sustain signal includes a voltage storage unit 800, a storage voltage supply unit 801, a voltage recovery unit 802, a resonator unit 803, and a sustain voltage supply unit ( 804 and a ground voltage supply 805 are preferred.

The voltage storage unit 800 includes a voltage storage capacitor unit C, and stores the voltage using the energy storage capacitor unit C.

The storage voltage supply unit 801 includes a storage voltage supply control switch unit S1, and the voltage stored in the voltage storage unit 800 is stored in the scan electrode of the plasma display panel using the storage voltage supply control switch unit S1. Y) or to the sustain electrode (Z).

The voltage recovery unit 802 includes a voltage recovery control switch S2, and the reactive energy of the scan electrode Y or the sustain electrode Z of the plasma display panel is reduced using the voltage recovery control switch S2. It is recovered to the voltage storage unit 800 to be stored.

The resonator 803 includes a resonant inductor part L, and the voltage stored in the voltage storage part 800 is transferred to the scan electrode Y or the sustain electrode Z using the resonant inductor part L. FIG. When supplied, the voltage of the scan electrode Y or the sustain electrode Z, that is, the reactive voltage of the scan electrode Y or the sustain electrode Z, is recovered when the voltage is returned to the voltage storage unit 800, that is, the LC resonance occurs. Let's do it.

The sustain voltage supply unit 804 includes a sustain voltage supply control switch unit S3, and the sustain voltage Vs generated by the sustain voltage source using the sustain voltage supply control switch unit S3 is the scan electrode Y or the like. It is supplied to the sustain electrode (Z).

The base voltage supply unit 805 includes a base voltage supply control switch unit S4, and the base voltage GND generated by the base voltage source using the base voltage supply control switch unit S4 is the scan electrode Y or the like. It is supplied to the sustain electrode (Z). That is, the scan electrode Y or the sustain electrode Z is grounded.

An example of the operation when the driving voltage Vcc for driving the switching elements in the circuit having such a configuration is stable, that is, larger than a predetermined threshold voltage, is as follows.

Referring to FIG. 8B, first, before the period d1, the base voltage supply control switch S4 of the base voltage supply unit 805 is turned on. Then, as before the period d1 of FIG. 8B, the voltage of the scan electrode Y or the sustain electrode Z maintains the base voltage GND.

Next, in the d1 period, the storage voltage supply unit 801 is turned on while the voltage recovery unit 802, the sustain voltage supply unit 804, and the base voltage supply unit 805 are all turned off.

Then, a current path through the voltage storage unit 800, the first node n1, the storage voltage supply unit 801, the second node n2, the resonator unit 803, and the third node n3. Is formed. Accordingly, the voltage stored in the voltage storage unit 800 is supplied to the scan electrode Y or the sustain electrode Z through LC resonance by the inductor portion L of the resonator 803.

Here, assuming that the voltage storage unit 800 has a sustain voltage of 0.5 times that is, that is, a voltage of 1/2 Vs, the voltage of the scan electrode Y or the sustain electrode Z is the maximum sustain voltage Vs in this d1 period. Can rise).

Next, in the d2 period, the sustain voltage supply control switch part S3 of the sustain voltage supply part 804 is turned on. Then, the sustain voltage Vs generated by the sustain voltage source is supplied to the scan electrode Y or the sustain electrode Z through the third node n3.

Accordingly, the scan electrode Y or the sustain electrode Z keep the sustain voltage Vs substantially constant.

Next, in the d3 period, the voltage recovery unit 802 in a state where both the sustain voltage supply control switch unit S3 of the sustain voltage supply unit 804 and the storage voltage supply control switch unit S1 of the storage voltage supply unit 801 are turned off. The voltage recovery control switch unit S2 is turned on.

Then, the scan electrode Y or the sustain electrode Z, the third node n3, the resonator 803, the second node n2, the voltage recovery unit 802, the first node n1, and the voltage storage A current path through the unit 800 is formed, and accordingly, the voltage of the scan electrode Y or the sustain electrode Z is recovered and stored in the voltage storage unit 800 through LC resonance by the resonator 803. do.

Thereby, the voltage of the scan electrode Y or the sustain electrode Z can fall from the sustain voltage Vs to the minimum base voltage GND.

In this way, the sustain signal can be supplied to the scan electrode Y or the sustain electrode Z. FIG.

Unlike the case of FIG. 8B, an example of the operation when the driving voltage Vcc for driving the switching elements in the circuit of FIG. 8A is unstable, that is, below a predetermined threshold voltage is as follows.

Referring to FIG. 8C, when the driving voltage Vcc is unstable, since the supply of the driving voltage Vcc is cut off, it is input to the gate terminal of the storage voltage supply control switch unit S1 of the storage voltage supply unit 801. As the supply of the driving voltage Vcc is cut off, the storage voltage supply control switch S1 is continuously turned off in the periods d1, d2, and d3.

In this manner, the voltage recovery control switch unit S2 of the voltage recovery unit 802, the sustain voltage supply control switch unit S3 of the sustain voltage supply unit 804, and the base voltage supply control switch unit of the base voltage supply unit 805 ( S4) is turned off in all of the periods d1, d2, and d3.

Accordingly, no driving signal is applied to the scan electrode Y or the sustain electrode Z. FIG.

In the above, only the case in which the supply of the driving voltage Vcc is cut off when the driving voltage Vcc is lower than the threshold voltage has been described. For example, the supply of the driving voltage Vcc can be cut off when the driving voltage Vcc is out of the range of 4V or more and 6V or less. This is as follows.

9 is a view for explaining another example of the configuration of a driving unit for cutting off the supply of the driving voltage when the driving voltage for driving the switching elements is unstable.

Referring to FIG. 9, another driving unit according to the present invention includes a threshold voltage generator 910, a first voltage comparator 920, a second voltage comparator 930, a discriminator 940, and a voltage breaker 950. ) May be included.

Here, the threshold voltage generator 910 generates the threshold voltage using another voltage Vd higher than the driving voltage Vcc for driving the switching elements.

In addition, the threshold voltage generator 910 may generate a threshold voltage by voltage-dividing the other voltage Vd described above, and the threshold voltage may include a first threshold voltage and a second threshold voltage. To this end, the threshold voltage generator 910 preferably includes a first resistor R1, a second resistor R2, and a third resistor R3.

For example, the other voltage Vd is 60V, the resistance value of the first resistor portion R1 is 13.5Ω (ohm), the resistance value of the second resistor portion R2 is 0.5Ω (ohm), 3 Assume that the resistance value of the resistor R3 is 1 Ω (ohm).

Then, the first threshold voltage across the tenth node n10 is 1.5 / 15 × 60 = 6V.

In addition, the second threshold voltage applied to the twentieth node n20 is 1/15 × 60 = 4V.

The first voltage comparator 920 compares the first threshold voltage generated by the threshold voltage generator 910 with the driving voltage Vcc and outputs the comparison result. For example, the first voltage comparator 920 may output a high signal when the driving voltage Vcc is less than or equal to the first threshold voltage, and output a low signal when the driving voltage Vcc is less than or equal to the first threshold voltage. .

Here, it is preferable that the high signal means normal and the low signal means abnormal.

In addition, the second voltage comparator 930 compares the second threshold voltage generated by the threshold voltage generator 910 with the driving voltage Vcc and outputs the comparison result. For example, the second voltage comparator 930 may output a high signal when the driving voltage Vcc is greater than or equal to the second threshold voltage, and output a low signal when the driving voltage Vcc is greater than or equal to the second threshold voltage. .

Here, it is preferable that the high signal is normal and the low signal is abnormal.

The determination unit 940 determines whether at least one of the comparison result output by the first voltage comparator 920 and the comparison result output by the second voltage comparator 930 is low.

For example, suppose that the first threshold voltage is 6V, the second threshold voltage is 4V and the driving voltage Vcc becomes unstable to 3.5V as in the previous example.

Then, since the driving voltage Vcc is smaller than the first threshold voltage and the second threshold voltage, the first voltage comparator 920 outputs a high signal that is a normal signal, and the second voltage comparator 930 is an abnormal signal. Outputs an in-low signal.

Then, the determination unit 940 determines that the driving signal Vcc supplied is unstable.

In contrast, when the driving voltage Vcc becomes unstable and becomes 7V, the first voltage comparator 920 detects a low signal that is an abnormal signal because the driving voltage Vcc is greater than the first and second threshold voltages. The second voltage comparator 930 outputs a high signal which is a normal signal.

Even in such a case, the determination unit 940 determines that the driving signal Vcc supplied is unstable.

When the driving voltage Vcc is unstable as a result of the determination by the determination unit 940, the voltage blocking unit 950 may block the supply of the driving voltage Vcc by using the voltage blocking switch unit S10.

In this manner, when the driving voltage Vcc is out of the range of the predetermined threshold voltage, it is also possible to cut off the supply of the driving voltage Vcc to prevent electrical damage to the switching element.

As such, the technical configuration of the present invention described above can be understood by those skilled in the art that the present invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention.

Therefore, the exemplary embodiments described above are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the appended claims rather than the foregoing detailed description, and the meaning and scope of the claims are as follows. And all changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

As described above in detail, the plasma display device of the present invention can prevent the electrical damage of the switching elements by blocking the supply of the driving voltage Vcc when the driving voltage Vcc for driving the switching element becomes unstable. It works.

Claims (5)

A plasma display panel having electrodes formed thereon; Driver for applying a drive signal to the electrode Including, And the driving unit includes a switching element for performing a switching operation, and cuts off the supply of the driving voltage when the driving voltage for driving the switching element is less than or equal to a predetermined threshold voltage. The method of claim 1, The driving unit A threshold voltage generator configured to generate the threshold voltage using another voltage higher than the driving voltage; A voltage comparing unit comparing the threshold voltage with a driving voltage; And A voltage blocking unit to block the supply of the driving voltage when the driving voltage is less than or equal to a threshold voltage as a result of comparing the voltage comparing unit; Plasma display device comprising a. The method of claim 2, And the threshold voltage generator is to divide the other voltage to generate the threshold voltage. The method of claim 1, The driving voltage is substantially 5V, and the threshold voltage is 3V or more and less than 5V. The method of claim 4, wherein And the threshold voltage is 4V or more and 4.5V or less.

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