JP3084774B2 - Driving method of plasma display panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a so-called dot matrix type memory type AC plasma display panel used for personal computers and office workstations, which have been remarkably advanced in recent years, and wall-mounted televisions, which are expected to develop in the future. Regarding the driving method,
In particular, the present invention relates to a method for driving a plasma display panel that reliably erases a preliminary discharge for stably performing a writing discharge.

[0002]

2. Description of the Related Art A conventional AC plasma display panel has a structure shown in FIG. In FIG.
(A) is a plan view, and (B) is an aa ′ sectional view of (A). The plasma display panel includes a first insulating substrate 11 made of glass, a second insulating substrate 12 also made of glass, a row electrode 13, a column electrode 14, a discharge gas space 15 filled with a discharge gas such as He, Xe, or the like. A partition wall 16 that secures a gas space and separates pixels, a phosphor 17 that converts ultraviolet light generated by discharge of a discharge gas into visible light,
Insulator 18 covering the row electrode, M protecting the insulator from discharge
The protective film 19 is made of gO or the like. In FIG. 6A, reference numeral 20 indicates a pixel.

In the plasma display panel having such a configuration, once a pulse voltage is applied between the column electrode 14 and the row electrode 13 to cause a discharge, a sustain pulse is thereafter applied between the adjacent row electrodes 13. , The discharge is maintained between the row electrodes 13. Such a function is called a memory function. In addition, a pulse having a voltage higher than the sustain pulse may be applied between the row electrodes 13 to cause a discharge. Further, when a low-voltage pulse having a narrow pulse width called an erase pulse is applied to the row electrode 13, the discharge can be stopped.

Accordingly, if the row electrodes 13 and the column electrodes 14 are striped as shown in FIG. 6 and are arranged so as to be orthogonal to each other, a dot matrix display can be obtained. Further, if the phosphors 17 are separately applied to three colors, a plasma display capable of color display can be obtained.

Next, FIG. 7 shows a diagram focusing only on the electrodes of the plasma display panel. 7, 21 is a plasma display _{panel, S 1, S 2, ...} , S m row _{electrodes, D 1, D 2, ...} , D n denotes the column electrodes.

[0008] As shown in FIG. 8, a so-called one-field time for performing display control of one pixel, that is, a so-called one-field time is divided into a display control sub-field and a pre-discharge sub-field. In this case, the entire image is forcibly discharged once (called pre-discharge) to make each pixel easy to discharge, thereby making it difficult to cause a mistake in writing discharge for image display. FIG. 9 shows an example of an applied voltage waveform when the entire screen is predischarged collectively. In FIG. 9, first, the pixels on the entire screen are discharged by the predischarge pulse, and then the predischarge is stopped by the predischarge erase pulse. In this case, two types of erase pulses, narrow width and wide width, have been conventionally used (for example, edited by Kenichi Owaki and Yoshinori Yoshida,
"Plasma Display", 1983, Kyoritsu Publisher,
p, 90).

In the discharge by the sustain pulse, the time from the rise of the voltage to the completion of the discharge is 1 to 4 microseconds. Compared to this time, a case where the erase pulse width is relatively short is called narrow pulse erase, and a case where it is long is called wide pulse erase. As shown in FIG. 10, erasing is performed by a pulse having a pulse width of about 0.5 to 1 microsecond in the narrow pulse erasing, and by a pulse having a pulse width of about 5 to 10 microsecond in the wide pulse erasing. Generally, narrow pulse erasing is often used because the range of erasable voltage is wider.

If the screen is particularly large, the entire screen is divided into a plurality of blocks, and the sequence shown in FIG. 8 is applied to each block. Also, in one field,
The preliminary discharge subfield may be inserted more than once.

[0009]

However, as the number of pixels of the plasma display panel increases, the variation in discharge characteristics of each pixel increases. Regardless of the method of erasing the narrow pulse or the wide pulse, it has been difficult to erase the entire screen or the entire surface of each block at a time.

An object of the present invention is to provide a plasma display panel having a large number of pixels, in which a whole screen or the entire surface of each block is preliminarily discharged at the same time, and a driving operation of the plasma display panel which can realize a reliable erasing operation of the predischarge. It is to provide a method.

[0011]

According to the present invention, a pixel is provided.
The display control subfield displays the time of one field for display control.
Field time and pre-discharge subfield time,
Pre-discharge within each field
Apply a pre-discharge pulse to forcibly discharge all pixels once.
After that, apply the pre-discharge erase pulse to stop the pre-discharge.
A method of driving a dot matrix type AC plasma display panel having a memory function as described above,
A method for driving a plasma display panel, characterized in that a pre-discharge sustaining pulse is inserted between a pre-discharge pulse applied during the pre-discharge subfield time and a pre-discharge erase pulse.

Further, according to the present invention, the display control of the pixel is controlled.
Display the time of one field to be performed Control subfield time
And divided into pre-discharge subfield time and one field
Within the pre-discharge subfield time
To discharge all pixels once and apply a preliminary discharge.
Pre-discharge is stopped by applying an erase pulse.
A method of driving a dot matrix type AC plasma display panel having a memory function, wherein a current limiting element is inserted into a pre-discharge erasing circuit to slow down the rise of the voltage of the pre-discharge erasing pulse. A panel driving method is obtained.

Further, according to the present invention, the display control of the pixel is controlled.
Display the time of one field to be performed Control subfield time
And divided into pre-discharge subfield time and one field
Within the pre-discharge subfield time
To discharge all pixels once and apply a preliminary discharge.
Pre-discharge is stopped by applying an erase pulse.
A method of driving a dot matrix type AC plasma display panel having a memory function , wherein a continuous unipolar pulse whose voltage or pulse width monotonically increases is used as the preliminary discharge erasing pulse. A driving method is obtained.

[0014]

According to the present invention, the conventional problems are solved by adopting the above-mentioned structure. That is, in the first aspect, the preliminary discharge sustaining pulse is inserted between the preliminary discharge pulse and the preliminary discharge erase pulse. The pre-discharge pulse requires a higher voltage and a wider pulse width than the sustain pulse to generate a discharge. As a result, the intensity of the preliminary discharge becomes very strong. Therefore, in order to weaken the discharge generated by the preliminary discharge pulse, a preliminary discharge sustaining pulse having a lower voltage and a narrower pulse width than the preliminary discharge pulse was inserted after the preliminary discharge pulse, and then a preliminary discharge erasing pulse was inserted. However,
The preliminary discharge could be erased with a very high probability over the entire screen or the entire surface of each block.

According to the second aspect of the present invention, by erasing the discharge by weakening the discharge by inserting a resistor or a transistor for limiting the current of the erase discharge into the circuit for generating the erase pulse to suppress the current peak value of the discharge by the erase pulse. The pulse erasing ability could be enhanced. At this time, the rising of the erasing pulse voltage is reduced by the current limiting elements such as the resistors and the transistors and the capacitance of the panel. In particular, when pre-discharging and erasing the entire screen at once, increasing the resistance value of the current limiting element and delaying the rise of this voltage can prevent pixels that remain lit due to erroneous erasure. This is effective for completely erasing the entire screen or the entire surface of each block. In addition, the pulse width at this time needs to be increased in accordance with the rise time so that the peak voltage of the erasing pulse that gradually rises sufficiently rises.

Further, in the third invention, the erasing power can be enhanced by using a continuous pulse whose voltage or pulse width monotonously increases as the erasing pulse.
That is, for the first pulse for erasing, the voltage and the pulse width are reduced to first erase the easily erasable pixels. In the next second pulse for erasing, the voltage and the pulse width are made larger than those in the first pulse to erase pixels which are more difficult to erase.
At this time, if the interval between the pulses for erasing was set to an appropriate value or more, discharge did not occur again in the pixels already erased. In this way, by gradually increasing the voltage and pulse width of a continuous pulse for erasing, it is possible to erase the entire screen or the entire surface of each block at once.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 6 and 7 where m = 241, n = 480, and a diagonal 10-inch panel is used.

FIG. 1 shows voltage waveforms according to the first embodiment of the present invention. Odd row electrodes S _1, S _3, ..., the S _m,
A pre-discharge pulse having a pulse width of 10 microseconds for simultaneously pre-discharging the entire surface of the panel together with a sustain pulse having a frequency of 60 kHz, and a pre-discharge having a pulse width of 1 micro-second for erasing the pre-discharge performed simultaneously on the entire panel. An erase pulse has been applied. Further, even-numbered row electrodes S ₂ , S
₄ ,..., S _m-3 , and S _m-1 are applied with a sustain pulse and a pre-discharge sustain pulse having a pulse width of 1.5 microseconds for weakening the pre-discharge performed simultaneously on the entire panel. ing. The voltage of the preliminary discharge sustaining pulse may be the same as the sustaining pulse voltage unless otherwise required. Further, it is preferable that the pulse width is as narrow as possible within a range that does not become a narrow erase pulse to weaken the discharge.

By using such a pre-discharge sustaining pulse, the entire pre-discharge erasing operation, which could not be realized by the conventional erasing pulse alone, can be performed and the plasma display panel can be operated normally. .

Here, the case where the conventional narrow erase pulse is used as the preliminary discharge erase pulse has been described.
The pre-discharge erase pulse is not limited to this, and a conventional wide erase pulse or an erase pulse according to the second and third aspects of the present invention described below may be used.

FIG. 2 shows an erase pulse voltage waveform according to the second embodiment of the present invention. Odd row electrodes S ₁ , S ₃ ,.
A pre-discharge pulse having a pulse width of 10 microseconds for simultaneously pre-discharging the entire panel is applied to S _m together with a sustain pulse having a frequency of 60 kHz. The even-numbered row electrodes S ₂ , S ₄ ,..., S _m−3 , and S _m−1 have a rising pulse for eliminating the pre-discharge performed on the entire panel together with the sustain pulse. A discharge erase pulse is applied. FIG. 3 is an example of a circuit for generating an erase pulse according to the present embodiment. This circuit forms an even number of row electrodes S ₂ , S
_4, ..., are connected to the _{S m-3, S m-} 1. The conventional circuit is
Although there was no resistor R1 in FIG. 3, this circuit of the present embodiment
Unlike the conventional case, a resistor R1 is provided as a current limiting element for erasing discharge. FIG. 4 shows erasing characteristics when the rising time and pulse width of the preliminary discharge erasing pulse are changed in the above-described plasma display panel using such a pulse waveform and circuit. In FIG. 4, the vertical axis indicates an erase voltage margin serving as a measure of the erase capability of the erase pulse, that is, the range of the erase voltage in which a normal erase operation can be performed. As can be seen from this figure, when the rising time and width of the erase pulse are both 40 microseconds or more,
It turned out that a normal erase operation was performed. By using such a pre-discharge erasing pulse, it is possible to erase the entire pre-discharge collectively, which could not be realized by the conventional narrow-wave or wide-width rectangular wave erasing pulse. Can now work.

When the preliminary discharge erase pulse was tested on plasma display panels having different display areas, it was effective to increase the rise time and pulse width of the preliminary discharge erase pulse in a panel having a larger area.

In the present embodiment, a resistor is used as the current limiting element. However, the current limiting element is not necessarily required to be a resistor. For example, the transistor TR1 for generating an erase pulse may have a current limiting capability. Further, the circuit for generating the erase pulse is not limited to the circuit used in the description here, and a circuit of a different type may be used.

FIG. 5 shows an erase pulse voltage waveform according to the third embodiment of the present invention. Odd row electrodes S ₁ , S ₃ ,
…, S _m , together with a sustain pulse having a frequency of 60 kHz,
Pulse width 10 for pre-discharge the entire panel at once
A microsecond pre-discharge pulse is applied. Also,
The even-numbered row electrodes S ₂ , S ₄ ,..., S _m-3 , and S _m-1 have erasure first to fifth erasures for erasing the preliminary discharges performed simultaneously on the entire panel together with the sustain pulse. Pulse is applied. The pulse width of the first to fifth erasing pulses was set to 1 microsecond in order to perform narrow erasing. The interval between these erasing pulses is set to 5 microseconds or more so that the erasing pulses do not affect each other and do not interact with each other. The voltage was set so as to cover the range from the lowest to the highest erase voltage of the pixels of the entire panel.

By using such a pre-discharge erasing pulse, the entire pre-discharge erasing operation, which could not be realized by a conventional narrow pulse or wide width erasing pulse of one rectangular wave, can be performed. This allows the plasma display panel to operate normally.

When this preliminary discharge erase pulse was tested on a plasma display panel having a different display area, the effect of increasing the number of erase pulses for a panel having a larger area was more effective. Also, unlike the present embodiment, the same effect was obtained by increasing the pulse width instead of gradually increasing the voltage of the erasing pulse. At this time, it was effective to change the pulse width from a narrow width of 0.5 microseconds to a wide width of about 20 microseconds.

In the above embodiment, the case where the plasma display panel shown in FIGS. 6 and 7 is driven has been described. However, the present invention is not limited to this, and any type of AC memory type plasma display may be used. It goes without saying that it can also be applied to panels. When the number of pixels is particularly large, the entire screen may be divided into a plurality of blocks, and the preliminary discharge and erasure of the preliminary discharge using the present invention may be performed for each block. Further, the second and third aspects of the present invention may be used in combination with the first aspect.

[0028]

As is apparent from the above description,
By using the pre-discharge sustaining pulse, the erase pulse with a rising edge, or a plurality of erasing pulses according to the present invention, the pre-discharge erasing ability is significantly improved as compared with the conventional erasing method using a single rectangular wave pulse. A high driving method can be obtained. Therefore, the erasing operation of the preliminary discharge in the plasma display panel having a large area, high definition, and a large number of pixels becomes more reliable, which is industrially very useful.

[Brief description of the drawings]

FIG. 1 is a diagram showing a voltage waveform according to the first invention of the present application.

FIG. 2 is a diagram showing a voltage waveform according to a second invention of the present application.

FIG. 3 is a diagram showing a circuit for generating an erase pulse according to the second invention of the present application.

FIG. 4 is a diagram showing an erase margin according to the second invention of the present application;
(A) is a diagram showing the relationship between the rising time of the erase pulse and the erase voltage margin, and (B) is a diagram showing the relationship between the pulse width and the erase voltage margin.

FIG. 5 is a diagram showing a voltage waveform according to the third invention of the present application.

FIGS. 6A and 6B show a plasma display panel, wherein FIG. 6A is a plan view and FIG.

FIG. 7 is a diagram showing a configuration of a plasma display panel focusing on electrode arrangement.

FIG. 8 is a diagram showing how to use one field time.

FIG. 9 is a diagram showing a conventional erase pulse waveform.

10A and 10B are diagrams illustrating a conventional erase pulse. FIG. 10A illustrates an example of a narrow erase pulse, and FIG. 10B illustrates an example of a wide erase pulse.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 1st insulating substrate 12 2nd insulating substrate 13 Row electrode 14 Column electrode 15 Discharge gas space 16 Partition 17 Phosphor 18 Insulator 19 Protective film 20 Pixel

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G09G 3/28-3/29 G09G 3/20

Claims (3)

(57) [Claims] 1. One field for controlling display of a pixel
Display between the control subfield time and the preliminary discharge subfield
The pre-discharge subfield for each field.
Apply a pre-discharge pulse within the
After discharging all pixels once, apply the pre-discharge erase pulse.
Matrix AC plasma display panel having a memory function for stopping preliminary discharge by using
Driving method, wherein the preliminary discharge subfield time
A pre-discharge sustaining pulse is inserted between a pre-discharge pulse and a pre-discharge erasing pulse to be applied to the plasma display panel. 2. One field for controlling display of a pixel.
Display between the control subfield time and the preliminary discharge subfield
The pre-discharge subfield for each field.
Apply a pre-discharge pulse within the
After discharging all pixels once, apply the pre-discharge erase pulse.
Matrix AC plasma display panel having a memory function for stopping preliminary discharge by using
The driving method of the plasma display panel according to the above (1), wherein a current limiting element is inserted into an erasing circuit of the pre-discharge to slow down the rise of the voltage of the pre-discharge erasing pulse. 3. In one field for controlling display of a pixel.
Display between the control subfield time and the preliminary discharge subfield
The pre-discharge subfield for each field.
Apply a pre-discharge pulse within the
After discharging all pixels once, apply the pre-discharge erase pulse.
Matrix AC plasma display panel having a memory function for stopping preliminary discharge by using
In the driving method of the above, as the preliminary discharge erasing pulse,
A method for driving a plasma display panel, comprising using a continuous monopolar pulse whose voltage or pulse width monotonically increases.