JP5152161B2 - Driving method of plasma display panel - Google Patents

Description

The present invention relates to a display device and a driving method thereof, and in particular, a display device that repeats sustain discharge by a sustain discharge pulse (light emission pulse) such as a plasma display panel (PDP) and adjusts light emission according to the number of repetitions. And a driving method thereof.

2. Description of the Related Art In recent years, with the increase in size of display devices, thin display devices are required, and various types of thin display devices are provided. For example, matrix panels that display digital signals as they are, that is, gas discharge panels such as PDPs, matrix panels such as DMD (Digital Micromirror Device), EL display elements, fluorescent display tubes, and liquid crystal display elements are provided. . Among such thin display devices, the gas discharge panel is easy to enlarge because of a simple process, is self-luminous, has good display quality, and has a high response speed. It is considered as the most promising candidate for a large-screen direct-view HDTV (high-definition television) display device.

For example, in a PDP, each field has a plurality of light emission blocks (subfield: SF) composed of a plurality of sustain discharge pulses, and a halftone is displayed by a combination of the subfields. That is, in the PDP, the light emission time is adjusted by repeating the sustain discharge by the sustain discharge pulse, and the display gradation is expressed.

By the way, the current in the sustain discharge period (sustain discharge current) is small at the start position of the sustain discharge period, and increases as the process proceeds to the second half after the sustain discharge is repeated. Since the sustain discharge consumes electric power, a sustain discharge voltage drop that is inversely proportional to that occurs, and the sustain discharge is incomplete due to this decrease in the sustain discharge voltage. There is a demand for a display device capable of performing control in consideration of the above and a driving method thereof.

In this specification, the term “field” is used assuming that, for example, two frames of an odd number and an even number for interlaced display of an image of one frame are used. When an image is displayed progressively, the word “field” can be applied as it is by replacing it with “frame”.

Conventionally, the setting of the sustain discharge pulse is performed, for example, by calculating the display load factor for each frame from the display data, and calculating based on the display load factor for each frame (field). It is controlled not to exceed a certain value. References disclosing such technology include, for example, Japanese Unexamined Patent Publication Nos. 06-332397 and 2000-098970.

Specifically, Japanese Patent Application Laid-Open No. 06-332397 discloses an integration unit that integrates the number of pixel signals of a predetermined level given during a predetermined period, and a frequency change unit that changes the panel drive frequency based on the integration result of the integration unit. Japanese Patent Laid-Open No. 2000-098970 discloses integrating means for integrating the number of pixel signals given during a predetermined period in units of bit signals for gradation display. A plasma display device is disclosed that includes frequency changing means for changing the frequency of the sustain discharge waveform based on the integration result of the integrating means.

FIG. 1 is a block diagram showing an example of a display device to which the present invention is applied, and shows an example of a plasma display device (plasma display panel: PDP). In FIG. 1, reference numeral 1 is a data converter, 2 is a frame memory, 3 is a power control circuit, 4 is a driver control circuit, 5 is a power supply, 6 is an address driver, 7 is a Y driver, 8 is an X driver, and 9 Indicates a display panel.

As shown in FIG. 1, the data converter 1 receives an image signal and a vertical synchronization signal Vsync from the outside, and converts them into PDP data (data for displaying an image by a plurality of subfields SF). The frame memory 2 holds the data for the next field converted by the data converter 1 for PDP. Then, the data converter 1 supplies the data previously held in the frame memory 2 as address data to the address driver 6 and supplies the display load factor to the driver control circuit 4. Here, the display load factor is a load factor obtained by counting the number of lit cells (light emitting dots) in each subfield.

The driver control circuit 4 receives the control signal of the number of sustain discharge pulses (number of sustain pulses) of each subfield (SF) and the internally generated vertical synchronization signal Vsync2 from the power control circuit 3, and controls the drive to the Y driver 7. Supply data. Note that the display load factor data signal from the data converter 1 is supplied to the power control circuit 3 via the driver control circuit 4.

The display panel 9 is provided with address electrodes A1 to Am, Y electrodes Y1 to Yn, and an X electrode X, which are driven by an address driver 6, a Y driver 7, and an X driver 8, respectively. The power supply 5 supplies power to the address driver 6, Y driver 7 and X driver 8, and detects the voltage and current for the address driver 6, Y driver 7 and X driver 8 and supplies them to the power control circuit 3. . That is, the address voltage and current of the address driver 6 and the detected values of the sustain discharge voltage and sustain discharge current of the Y driver 7 and the X driver 8 are supplied from the power supply 5 to the power control circuit 3, and are processed in the power control circuit 3. used. Here, the display panel unit includes an address driver 6, a Y driver 7, an X driver 8, and a display panel 9.

FIG. 2 is a diagram for explaining an example of a driving method in the display device shown in FIG.

The driving method shown in FIG. 2 displays an image of one frame by interlacing in two fields, odd and even, and each odd field and even field has a plurality of subfields (for example, seven subfields SF0 to SF0). SF6). Each of the subfields SF0 to SF6 has an address discharge period in which the address discharge of the lighted cell is performed according to the address data, and a sustain discharge pulse (light emission pulse) is applied to the selected cell (lighted cell) to maintain light emission. It has a discharge period (light emission period). Here, the weights of the subfields SF0 to SF6 are SF0: SF1: SF2: SF3: SF4: SF5: SF6 = 1: 2: 4: 8: 16: 32: 64.

FIG. 3 is a diagram for explaining another example of the driving method in the display device shown in FIG.

In the driving method shown in FIG. 3, one frame image is displayed progressively in one field, and each field (frame) is composed of a plurality of subfields (for example, six subfields SF0 to SF5). The Each of the subfields SF0 to SF5 has an address discharge period in which address discharge of the lighted cell is performed according to address data, and a sustain discharge period in which a sustain discharge pulse is given to the selected cell to emit light. Here, the weights of the subfields SF0 to SF5 are SF0: SF1: SF2: SF3: SF4: SF5 = 1: 2: 4: 8: 16: 32.

Needless to say, the number of subfields, weights, and the like in FIGS. 2 and 3 can be variously set.

Japanese Patent Laid-Open No. 06-332397 JP 2000-098970 A

FIG. 4 is a diagram for explaining an example of a driving method of a conventional display device, and shows the relationship between the sustain discharge voltage Vs, the sustain discharge current Is, and the sustain discharge pulse period Tsus (Tsus0, Tsus1, Tsus2). .

As shown in FIG. 4, in the sustain discharge period Tsus (Tsus1) of each subfield SF (for example, subfield SF1), the sustain discharge current Is gradually increases from the start position SDs and is maintained in inverse proportion thereto. The discharge voltage Vs gradually decreases. Since sustain discharge current Is has a maximum value at end position SDe of sustain discharge period Tsus (Tsus1), sustain discharge voltage Vs has a minimum value at end position SDe of sustain discharge period Tsus (Tsus1). The pulse width of the sustain discharge pulse is constant (for example, 2 μs) throughout the entire sustain discharge period Tsus (Tsus1).

Further, in order to realize high luminance, it is necessary to increase the number of sustain discharge pulses. However, if the number of sustain discharge pulses is increased in this way, sustain discharge voltage Vs is further reduced.

By the way, in order to perform a complete sustain discharge in any case of displaying an image, a sustain discharge voltage Vs having a voltage drop as shown by a solid line in FIG. 4 is considered in consideration of the voltage drop. Therefore, it is necessary to set the sustain discharge voltage Vs ′ as shown by the alternate long and short dash line in FIG.

However, if the sustain discharge voltage Vs is set high, various problems such as the withstand voltage of the driver circuit, heat dissipation, or power consumption occur. Therefore, in reality, the sustain discharge voltage Vs cannot be set so high. Therefore, in the conventional display device, sufficient sustain discharge cannot be performed due to the voltage drop of the sustain discharge voltage Vs, and the display quality is also deteriorated.

The present invention has been made in view of the above-described problems of the conventional display device, and an object thereof is to provide a display device capable of maintaining high display quality without depending on the display load and a driving method thereof.

According to the first aspect of the present invention, there is provided a driving method of a display device that emits light by repeatedly applying a sustain discharge pulse, wherein the pulse width of the sustain discharge pulse is varied within one subfield. A display device driving method is provided.

According to the second aspect of the present invention, a display panel unit, a data converter that receives an image signal and supplies image data suitable for the display device to the display panel unit, and supplies power to the display panel unit There is provided a display device comprising: a power supply unit configured to perform a sustain discharge pulse control circuit that varies a pulse width of the sustain discharge pulse within one subfield.

As described above in detail, according to the present invention, it is possible to provide a display device capable of maintaining high display quality without depending on a display load and a driving method thereof.

It is a block diagram which shows an example of the display apparatus with which this invention is applied. It is a figure for demonstrating an example of the drive method in the display apparatus shown in FIG. FIG. 10 is a diagram for explaining another example of the driving method in the display device shown in FIG. 1. It is a figure for demonstrating an example of the drive method of the conventional display apparatus. It is a figure for demonstrating one Example of the drive method in the display apparatus which concerns on this invention. 4 is a flowchart illustrating an example of a driving method in the display device according to the present invention. It is a flowchart which shows the other example of the drive method in the display apparatus which concerns on this invention. It is a figure for demonstrating the other Example of the drive method in the display apparatus which concerns on this invention.

Hereinafter, embodiments of a display device and a driving method thereof according to the present invention will be described in detail with reference to the drawings. Note that the display device and the driving method thereof according to the present invention are not limited to the interlaced PDP, and can be widely applied to the progressive PDP and various display devices.

FIG. 5 is a diagram for explaining an embodiment of a driving method in the display device according to the present invention.

As is clear from the comparison between FIG. 5 and FIG. 4 described above, in the method for driving the display device according to the present embodiment, the sustain discharge voltage Vs having a voltage drop is not set high considering the voltage drop. Rather, the pulse width of the sustain discharge pulse is adjusted within one subfield (for example, SF1).

As shown in FIG. 5, the drop amount (voltage drop) of the sustain discharge voltage Vs in one subfield SF1 is different at each position of the sustain discharge period Tsus1. Specifically, the voltage level of the sustain discharge voltage Vs gradually decreases from the start position SDs of the sustain discharge period Tsus1, and reaches a minimum value at the end position SDe of the sustain discharge period Tsus1.

Therefore, in this embodiment, the pulse width (the width of the sustain discharge voltage level of the sustain discharge pulse) is narrowed (for example, 1 μs) near the start position SDs of the sustain discharge period Tsus1, and then the pulse width is widened at the intermediate position ( For example, in the vicinity of the end position SDe of the sustain discharge period Tsus1, the pulse width is further increased (for example, 3 μs) so that the voltage drop of the sustain discharge voltage Vs is widened to increase the pulse width of the sustain discharge pulse. To compensate. Here, it goes without saying that the pulse width of the sustain discharge pulse to be varied within one subfield is not limited to the above three pulse widths (1 μs, 2 μs, 3 μs).

That is, the pulse width of the sustain discharge pulse in one subfield is controlled to be narrow in the first half of the sustain discharge period Tsus and wide in the second half of the sustain discharge period, or the sustain discharge period Tsus. It can be controlled so that it is narrow at the beginning and gradually becomes wider after the sustain discharge period.

In the driving method of the display device of this embodiment, for example, the sustain discharge voltage is lowered near the end position of the sustain discharge period, so that the sustain discharge cannot be sufficiently performed, that is, a sufficient wall charge cannot be formed. By extending the pulse width of the sustain discharge pulse, a sufficient wall charge is formed even at a low sustain discharge voltage to perform complete sustain discharge.

Here, for example, when the display load factor of the entire field (frame) increases, the number of sustain discharge pulses is reduced in order to limit power consumption. In addition, the rest period generated at that time is diverted to the sustain discharge period, and a sustain discharge pulse with a wider pulse width is applied to a position where the sustain discharge current is large. It becomes possible to ensure display quality.

As described above, according to the display device driving method of this embodiment, it is possible to maintain high display quality by compensating for incomplete sustain discharge due to a voltage drop of the sustain discharge voltage without setting the sustain discharge voltage high. Is possible.

FIG. 6 is a flowchart showing an example of a driving method in the display device according to the present invention, in which the pulse width of the sustain discharge pulse is controlled in accordance with the number of sustain discharge pulses in one field.

As shown in FIG. 6, when the sustain discharge pulse control process is started, display data is input in step ST101, the process proceeds to step ST102, and the data converter 1 causes the display load factor (for each subfield SF ( L {SF (n)} is determined, and the weight of each subfield SF (for example, SF0: SF1: SF2: SF3: SF4: SF5 = 1: 2: 4: 8: 16: 32, FIG. 3), the weighted average load factor (WAL) is determined, and the process proceeds to step ST104 to determine (calculate) the number of sustain discharge pulses (S: number of SUS) in one field (frame).

Next, the process proceeds to step ST105, where the count value n = 0 of the subfield SF is set, and in step ST106, the calculated sustain discharge pulse number S and the pulse width of the sustain discharge pulse are commonly increased in all subfields SF. Comparison with the number A of sustain discharge pulses that can be performed (S ≦ A?).

If it is determined in step ST106 that S ≦ A is established, the process proceeds to step ST113, where the count value n is compared with the number of subfields SF (n ≧ N?). If it is determined in step ST113 that n ≧ N is not satisfied, that is, the count value n has not reached the maximum weight subfield SFn, the process proceeds to step ST114, and the number of sustain discharge pulses in each subfield SF is determined. The count value m = 0, and in step ST115, m is compared with M {SF (n)} (m ≧ M {SF (n)}?). Here, M {SF (*)} indicates the number of pulses having a pause time that can increase the pulse width of all the sustain discharge pulses in the subfield SF (*).

If it is determined in step ST115 that m ≧ M {SF (n)} does not hold, the process proceeds to step ST116, where P {SF (n), m} = P3 (sustained discharge pulse having a wide pulse width). Further, in step ST117, m = m + 1 is set, and the process returns to step ST115. Here, P {SF (*), m} indicates the output pulse width of the sustain discharge pulse in the subfield SF (*).

If it is determined in step ST115 that m ≧ M {SF (n)} is satisfied, the process proceeds to step ST118, returns to step ST113 with the count value n = n + 1, and repeats the same processing. If it is determined in step ST113 that n ≧ N is satisfied, that is, n has reached the maximum weight subfield SFn, the process ends.

As described above, the calculated sustain discharge pulse number S is smaller than the sustain discharge pulse number A in which the pulse width of the sustain discharge pulse can be increased by all the subfields SF in common (S ≦ A: step ST106). Further, when the number of sustain discharge pulses in each subfield SF is smaller than the number of pulses having a pause time that can increase the pulse width of all the sustain discharge pulses (m <M {SF (n)}: step ST115. ), The pulse widths of all the sustain discharge pulses of all the subfields SF are increased (P {SF (n), m} = P3: step ST116). If there is no sufficient pause period to make all the sustain discharge pulses thick, it is necessary to adjust the pulse width of the sustain discharge pulse in accordance with the total number of sustain discharge pulses in the field (frame).

In the method of adjusting the pulse width of the sustain discharge pulse, a variation point for changing the pulse width of the sustain discharge pulse is provided, and a threshold is set for changing the pulse width when the sustain discharge pulse is repeated. The threshold value needs to be set for each total sustain discharge pulse number of one field (one frame), and a variation table for each subfield SF corresponding to the total number of sustain discharge pulses of the one field is looked up in a lookup table ( (LUT). FIG. 6 illustrates an example in which attention is paid to a predetermined subfield SF at two variation points (T1, T2) for adjusting the pulse width of the sustain discharge pulse.

The processing flow will be described below.

If it is determined in step ST106 that S ≦ A is not established, the process proceeds to step ST107, where n is compared with the number of subfields SF (n ≧ N?). If it is determined in step ST107 that n ≧ N is not satisfied, that is, the count value n has not reached the maximum weight subfield SFn, the process proceeds to step ST108, and the calculated number of sustain discharge pulses S is set. And T1 {SF (n)} and T2 {SF (n)} are determined from the lookup table (LUT). Here, T1 {SF (*)} is a timing parameter for changing the pulse width in the subfield SF (*), and data of P3 (sustained discharge pulse having a wide pulse width) from what number of sustained discharge pulses. T2 {SF (*)} is a timing parameter for changing the pulse width within the subfield SF (*), and from what number of sustain discharge pulses P2 (intermediate pulse width) To determine the data (sustained discharge pulse).

In step ST109, the count value m is set to 0. In step ST110, m is compared with T1 (m ≧ T1?). If it is determined in step ST110 that m ≧ T1 is not established, in step ST111, P {SF (n), m} = P1 (sustained discharge pulse having a narrow pulse width) is set, and in step ST112, m = Return to step ST110 as m + 1.

If it is determined in step ST110 that m ≧ T1 is established, the process proceeds to step ST119, and the processes of steps ST119 to ST121 corresponding to steps ST110 to ST112 are performed. That is, if it is determined in step ST119 that m ≧ T2 is not established, in step ST120, P {SF (n), m} = P2 (intermediate pulse width sustain discharge pulse), and further in step ST121. , M = m + 1 and return to step ST119.

If it is determined in step ST119 that m ≧ T2 is established, the process proceeds to step ST122, and the processes of steps ST122 to ST124 corresponding to steps ST110 to ST112 (steps ST119 to ST121) are performed. That is, if it is determined in step ST122 that m ≧ M {SF (n)} does not hold, P {SF (n), m} = P3 (sustained discharge pulse having a wide pulse width) is set in step ST123. Further, in step ST124, m = m + 1 is set, and the process returns to step ST122.

If it is determined in step ST122 that m ≧ M {SF (n)} is satisfied, the process proceeds to step ST125, and n = n + 1 is set, and the process returns to step ST107 and the same process is repeated.

As described above, the pulse width variation points in the subfield SF (n) when the total number of pulses S in one field (one frame) is T2 {SF (n)} and T2 {SF (n)}. In this case, the pulse width of the subfield SF (n) is P1 (sustained discharge pulse having a narrow width) from the first discharge in the sustain discharge period (Tsus) to T1 {SF (n)} or less, and the sustain discharge period (Tsus). ) From T1 {SF (n)} to T2 {SF (n)} and below is P2 (sustained discharge pulse having an intermediate pulse width), and thereafter, P3 (sustained discharge pulse having a wide pulse width). Become. That is, the pulse width of the sustain discharge pulse is P1 <P2 <P3.

In the above, the mutation points T1 and T2 can be arbitrarily increased. In this case, further mutation points (T3,..., Tk) are set, and the mutation points T1 and T2 in the flowchart of FIG. This can be achieved by increasing the pulse width determination loop of the sustain discharge pulse used.

If it is determined in step ST107 that n ≧ N is satisfied, that is, n has reached the maximum weight subfield SFn, the process ends.

FIG. 7 is a flowchart showing another example of the driving method in the display device according to the present invention, in which the pulse width of the sustain discharge pulse is controlled according to the load factor of each subfield constituting one field.

That is, in the driving method shown in FIG. 6 described above, in step ST108, T1 {SF (n)}, T2 {SF (n) from the look-up table (LUT) based on the number S of sustain discharge pulses in one field. 7 is determined in step ST208 based on the load factor L {SF (n)} of each subfield constituting one field in step ST208. T1 {SF (n)} and T2 {SF (n)} are determined. Since other processes are common to FIGS. 6 and 7, the description thereof is omitted.

FIG. 8 is a diagram for explaining another embodiment of the driving method in the display device according to the present invention.

As apparent from the comparison between FIG. 8 and FIG. 5, the driving method of the display device of this embodiment is the first one in the sustain discharge period Tsus (Tsus1) of each subfield SF (for example, subfield SF1). The sustain discharge pulse is controlled to have a wide pulse width (for example, 4 μs) to ensure the connection from the address discharge to the sustain discharge. Other configurations (control of the pulse width of the sustain discharge pulse) are the same as those in FIG.

Here, in this embodiment, the pulse width of the first sustain discharge pulse in the sustain discharge period Tsus is controlled to be widened, but this is not limited to the first one. For example, The pulse width of the first two or three sustain discharge pulses may be controlled to be wide.

(Supplementary note 1) A display device driving method for emitting light by repeatedly applying a sustain discharge pulse, wherein the pulse width of the sustain discharge pulse is varied within one subfield. Method.

(Supplementary note 2) The display device driving method according to supplementary note 1, wherein a pulse width of the sustain discharge pulse is controlled in accordance with a voltage drop amount of the sustain discharge voltage.

(Supplementary note 3) In the display device driving method according to supplementary note 2, the sustain discharge pulse width is actually detected and controlled according to the detected sustain discharge voltage. A display device driving method.

(Supplementary note 4) In the display device driving method according to supplementary note 2, the pulse width of the sustain discharge pulse is detected as a load factor of a plurality of subfields constituting one field, and the load factor of the detected subfield is detected. The display device is controlled according to the method.

(Supplementary note 5) In the display device driving method according to supplementary note 2, the pulse width of the sustain discharge pulse is calculated according to the weighted average load factor of the entire field, and controlled according to the calculated weighted average load factor. A driving method of a display device.

(Appendix 6) In the method for driving a display device according to any one of appendices 1 to 5, the pulse width of the sustain discharge pulse is narrow in the first half of the sustain discharge period and in the second half of the sustain discharge period. Is a method for driving a display device, which is controlled to be wide.

(Supplementary note 7) In the method for driving a display device according to any one of supplementary notes 1 to 5, a pulse width of the sustain discharge pulse is narrow at the beginning of the sustain discharge period and after the sustain discharge period. A method for driving a display device, wherein the display device is controlled so as to gradually become wider as it goes.

(Supplementary note 8) In the display device driving method according to any one of supplementary notes 1 to 5, a pulse width of the sustain discharge pulse is narrow in a specific portion in the subfield and is specified in the subfield. A method for driving a display device, characterized in that control is performed so that the area after the portion gradually increases.

(Supplementary note 9) In the display device driving method according to any one of supplementary notes 1 to 8, the pulse width of the sustain discharge pulse is controlled so that at least the first one of the sustain discharge period is widened. A method for driving a display device.

(Supplementary note 10) In the display device driving method according to supplementary note 1, the pulse width of the sustain discharge pulse is calculated by calculating the total number of sustain discharge pulses in one field, and according to the calculated total number of sustain discharge pulses. A method for driving a display device, comprising: controlling the display device.

(Supplementary note 11) In the display device driving method according to supplementary note 10, the calculated total number of sustain discharge pulses is such that the number of sustain discharge pulses can increase the pulse width of the sustain discharge pulse in common to all subfields. And the number of sustain discharge pulses in each of the subfields is less than the number of pulses having a pause time that can increase the pulse width of all the sustain discharge pulses. A driving method of a display device, characterized in that the sustain discharge pulse has a wider pulse width.

(Supplementary note 12) In the driving method of the display device according to any one of supplementary notes 1 to 11, the one field includes a plurality of subfields, and a halftone is displayed by a combination of the subfields. Display device driving method.

(Supplementary note 13) The display device driving method according to any one of supplementary notes 1 to 12, wherein the display device is a plasma display device.

(Supplementary Note 14) A display panel unit, a data converter that receives an image signal and supplies image data suitable for the display device to the display panel unit, a power supply unit that supplies power to the display panel unit, and the sustain discharge pulse And a sustain discharge pulse control circuit for varying the pulse width of the sub-field within one subfield.

(Supplementary note 15) The display device according to supplementary note 14, wherein the sustain discharge pulse control circuit controls a pulse width of the sustain discharge pulse in accordance with a voltage drop amount of the sustain discharge voltage.

(Supplementary Note 16) In the display device according to supplementary note 15, the power supply unit actually detects the sustain discharge voltage, and the sustain discharge pulse control circuit performs the sustain discharge pulse according to the detected sustain discharge voltage. A display device which controls the pulse width of the display.

(Supplementary note 17) In the display device according to supplementary note 15, the data converter detects a load factor of each subfield constituting one field, and the sustain discharge pulse control circuit detects the load of each detected subfield. A display device that controls a pulse width of the sustain discharge pulse according to a rate.

(Supplementary note 18) In the display device according to supplementary note 15, the data converter calculates a weighted average load factor of an entire field, and the sustain discharge pulse control circuit determines the weighted average load factor according to the calculated weighted average load factor. A display device that controls a pulse width of a sustain discharge pulse.

(Supplementary note 19) In the display device according to any one of supplementary notes 14 to 18, the sustain discharge pulse control circuit is narrow in the first half of the sustain discharge period and wide in the second half of the sustain discharge period. Further, the display device controls the pulse width of the sustain discharge pulse.

(Supplementary note 20) In the display device according to any one of supplementary notes 14 to 18, the sustain discharge pulse control circuit is narrow at the beginning of the sustain discharge period and gradually increases after the sustain discharge period. A display device characterized by controlling a pulse width of the sustain discharge pulse so as to be wide.

(Supplementary note 21) In the display device according to any one of supplementary notes 14 to 18, the sustain discharge pulse control circuit is narrow in a specific portion in the subfield, and after the specific portion in the subfield. A display device characterized by controlling a pulse width of the sustain discharge pulse so as to be gradually widened.

(Supplementary note 22) In the display device according to any one of supplementary notes 14 to 21, the sustain discharge pulse control circuit has a pulse width of the sustain discharge pulse so that at least the first one of the sustain discharge period is widened. A display device characterized by controlling the display.

(Supplementary note 23) In the display device according to supplementary note 14, the display load factor from the data converter and the power information consumed by the display panel unit from the power supply unit are further received to determine the number of sustain discharge pulses. A power control circuit for adjusting, and the power control circuit calculates the number of sustain discharge pulses for one field, and the sustain discharge pulse control circuit determines the number of sustain discharge pulses according to the calculated number of sustain discharge pulses. A display device characterized by controlling a width.

(Supplementary Note 24) In the display device according to supplementary note 23, in the sustain discharge pulse control circuit, the calculated total number of sustain discharge pulses may increase the pulse width of the sustain discharge pulse in all subfields in common. When the number of sustain discharge pulses is less than the number of sustain discharge pulses, and the number of sustain discharge pulses in each subfield is less than the number of pulses having a pause time that can increase the pulse width of all the sustain discharge pulses, A display device characterized by increasing the pulse width of all the sustain discharge pulses in the subfield.

(Supplementary Note 25) In the display device according to any one of Supplementary Notes 14 to 24, the display device includes the one field configured by a plurality of subfields, and displays a halftone by a combination of the subfields. Characteristic display device.

(Supplementary note 26) The display device according to any one of supplementary notes 14 to 25, wherein the display device is a plasma display device.

DESCRIPTION OF SYMBOLS 1 ... Data converter 2 ... Frame memory 3 ... Power control circuit 4 ... Driver control circuit 5 ... Power supply 6 ... Address driver 7 ... Y driver 8 ... X driver 9 ... Display panel

Claims (8)

A driving method of a plasma display panel, wherein one frame is composed of a plurality of subfields, and light is emitted by repeatedly applying a sustain pulse during a sustain discharge period of at least one subfield of the plurality of subfields,
Applying a first widest sustain pulse first in the sustain discharge period; and
Applying a second sustain pulse that is narrower than the first sustain pulse after the first sustain pulse is applied;
Applying a third sustain pulse that is narrower than the first sustain pulse and wider than the second sustain pulse after the second sustain pulse is applied;
When the display load factor of display data is increased and the total number of sustain pulses in one frame is reduced, the width of the second sustain pulse is changed to a wider sustain pulse and applied. Display panel drive method. A method for driving a plasma display panel according to claim 1,
The second sustain pulse is applied a plurality of times,
When the display load factor of the display data is increased and the total number of sustain pulses in one frame is reduced, all of the second sustain pulses applied a plurality of times are changed and applied to a wider sustain pulse. A method for driving a plasma display panel. A method for driving a plasma display panel according to claim 2,
The method of driving a plasma display panel, wherein a pulse width of the wider sustain pulse is equal to a pulse width of the third sustain pulse. A method for driving a plasma display panel according to any one of claims 1 to 3,
The method of driving a plasma display panel, wherein the third sustain pulse is applied a plurality of times. A method for driving a plasma display panel according to claim 1,
The method of driving a plasma display panel, wherein the number of the second sustain pulses changes according to the total number of sustain pulses. A method for driving a plasma display panel according to claim 1,
The method of driving a plasma display panel, wherein the number of the second sustain pulses changes according to a load factor of a subfield. A method for driving a plasma display panel according to claim 1,
Even if the display load factor of the display data changes, the pulse width of the first sustain pulse,
The method of driving a plasma display panel, wherein a pulse width of the third sustain pulse does not change. A driving method of a plasma display panel, wherein one frame is composed of a plurality of subfields, and light is emitted by repeatedly applying a sustain pulse during a sustain discharge period of at least one subfield of the plurality of subfields,
Applying the widest sustain pulse at the beginning of the sustain discharge period of the subfield;
A step of repeatedly applying at least a first sustain pulse as a sustain pulse to be repeatedly applied and a second sustain pulse having a wider pulse width than the first sustain pulse, a plurality of times;
A plasma display, wherein the second sustain pulse is applied without applying the first sustain pulse when the display load factor of display data increases and the total number of sustain pulses in one frame decreases. Panel drive method.

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