JPH09311320A - Plasma address type liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a burn-in phenomenon of a liquid crystal display element with a simple circuit constitution. SOLUTION: In this device, a power source charging circuit 18 is provided in the power source of a plasma driver 11 successively impressing scanning pulses (plasma pulses) for generating plasma discharges on switching elements Tr1-Tr450 of respective scanning lines L1-L450 and when the power source of a PALC is turned off, driving voltages of respective liquid crystal display elements are made zero and a power source voltage for plasma discharge is made to be supplied with respect to the plasma drive 11 over at least one field period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma address type liquid crystal display device using, for example, a plasma address type liquid crystal display element for forming an image by an active matrix system.

[0002]

2. Description of the Related Art Recently, in consideration of an installation space that can be secured at home, for example, a television receiver of a large size and a thin type, a rear projection type in order to obtain a more powerful image. Projector devices have become popular. These television receivers and rear projection type projector devices have been considerably thinner than those of the past in accordance with technological progress, but in the case of television receivers, for example, CRT (Cathode Ray Tube). depth,
Further, in the case of a projector device, there is a limit to a reduction in thickness due to structural conditions such as an angle at which a projection lens is installed.

A display device using a TFT (Thin Film Trangistor) liquid crystal panel can be made thinner than the above-mentioned television receiver and projector device. However, in order to make a large display device, it is formed by IC technology. As the number of TFTs increases, a more precise manufacturing technique is required, and the manufacturing yield is lowered, so that the manufacturing cost becomes extremely high.

Therefore, a plasma addressed liquid crystal display element (Plasma Addressed Liquid Crystal) having a large screen equivalent to that of a television receiver and a projector and realizing a thinness equivalent to that of a liquid crystal display is hereinafter abbreviated. A display device using a PALC) as a display unit has been considered. This plasma-addressed liquid crystal display element makes use of the advantages of the TFT liquid crystal display device such as high brightness and high contrast, as well as PDP (Plasma Displ
It is possible to realize a large screen by the technology of ay Panel).

FIG. 6 is a perspective view showing a part of the structure of PALC, and a part thereof is shown in cross section. PALC20
Is structured as a transmissive display element that forms an image by selectively transmitting a light beam emitted from a backlight (not shown) arranged on the back surface thereof by an active matrix method.

The plasma substrate 21 has partition walls 22, 22,
22 form a scanning groove 23, 23, 23,..., Or a cut groove (not shown), which is partitioned into a hollow shape in the horizontal direction, for example. In the scanning grooves 23, the anodes 24, 2
, And cathodes 25, 25, 25,.
Are formed as a pair. That is, the scanning groove 23 forms a horizontal scanning line corresponding to the effective screen of the PALC 20, and is constituted by the number of scanning lines (for example, about 450 ... Effective scanning line number). Partition walls 22, 2
The scanning grooves 23, 23, 23, ... Can be sealed by arranging a glass substrate 26 forming an insulating layer in front of 2, 22, and a mixed rare gas such as helium gas can be used as a plasma gas inside. It is filled with gas.

A scanning voltage, for example, a negative polarity pulse of about -300 V is applied to the cathode 25 from a plasma driver circuit (not shown), and is supplied at a predetermined timing, as will be described in detail later. Plasma discharge is performed between the anode 24 and the cathode 25 by the plasma pulse. By this plasma discharge, an electrical conductor (plasma channel) is formed in the scanning groove 23 until plasma particles ionized by the plasma gas are completely eliminated, and the same operation as the switching element is performed.

In front of the glass substrate 26, a liquid crystal display element 27 forming pixels in a matrix, and striped filter portions 28G, 28B corresponding to RGB colors, 2 and 2.
8R, a stripe-shaped drive electrode 29G, 29B, 2 for driving pixels of the liquid crystal display element 27.
The transparent electrode layer 29 made of 9R forms the scanning grooves 23, 23, 23.
Are formed so that this orthogonal portion becomes one pixel. That is, the drive electrodes 29G, 29B, 29
Pixels intersecting the drive electrodes 29 (G, B, R) and the scanning groove 23 are supplied to R by supplying a video signal for each horizontal line and sequentially discharging the plasma gas in the scanning groove 23 in the vertical direction. Image signal is applied to the liquid crystal of
A color image can be displayed because the transmittance of light emitted from the backlight is different in each pixel.

That is, as shown in FIG.
A polarization filter 30 on the incident side and the output side of
By arranging 31, the transmission amount of light polarized by the liquid crystal display element 27 can be controlled, and a color image can be obtained by the same principle as that of a normal TFT liquid crystal display device.

Next, the switching operation for forming an image for one field will be described in more detail with reference to FIGS. FIG. 7 is a diagram schematically showing a part of the PALC 20 shown in FIG. 6 from a side surface. A switch SW is shown for convenience of explanation of the switching operation by the plasma channel.

As described above, the cathode 25 is, for example,
When plasma discharge is performed using 300 V as a power source, the scanning groove 2
3, a plasma channel is formed, and this plasma channel serves as a virtual electrode, and a voltage is applied between the transparent electrode layer 29 and the anode 24. That is, the illustrated switch SW is connected.

FIG. 8A shows a state in which plasma is generated when a voltage of -300 V is applied to the plasma channel by the switch SW. As shown, when a plasma channel is formed by plasma discharge, the inside of the scanning groove 23 becomes conductive, which is shown in FIG.
This can be explained as the operation of the FET switching element as shown in (b).

By the switching operation by the plasma channel, a virtual electrode is generated on the inner surface of the glass substrate 26 of FIG. 6, and a driving voltage (video signal) for driving a pixel is applied to the driving electrode 29 (G, B, R). By doing so, the scanning groove 23 and the drive electrode 29 (G, B, R) during plasma discharge
The driving voltage is applied to each pixel (for one line) of the liquid crystal display element 27 which is the intersection point of.

Therefore, the plasma discharge is sequentially scanned in the groove 2.
3 (1st line to 450th line) is scanned so as to occur, and for example, an image of 1 field is formed 450.
The drive electrodes 29 (G, B,
By applying the voltage to R), it is possible to display an image for one field. That is, one field is formed by selecting which line image is to be formed by the plasma channel and then applying a drive voltage for forming an image of that line to the drive electrode 29 (G, B, R). It realizes the selective scanning of the lines. At this time, the filter portions 28G, 28B, 2 of the filter layer 28
By transmitting 8R, a color image can be displayed. As a result, by sequentially applying the drive voltage to the gate electrodes from the first line to the 450th line in synchronization with the driving of pixels for one line, it is possible to form an image for one field.

By configuring the display device using the PALC 20 capable of forming an image with such a structure and operation principle as a display portion, a thin, lightweight and large-screen display device can be configured. .

[0016]

However, for example, PA
If the user turns off the power by himself / herself while monitoring the image displayed on the LC20, or if the power is momentarily cut off due to a power failure or the like while using the display device (hereinafter, simply referred to as power off), At that moment, the plasma discharge may become unstable and the discharge may not be partially performed even within the same scanning groove 23. In this case, the liquid crystal display element 2
The drive voltage (residual charge) applied to 7 causes the power to be cut off in a state where the liquid crystal molecules are twisted, and the image written when the power is turned off is partially retained as it is. That is, when the liquid crystal molecules are left unaligned, a phenomenon similar to the burn-in of a CRT occurs.

When the power is turned on again in this state, the liquid crystal display element 27 is driven by the switching due to the plasma discharge. However, the liquid crystal molecules left in a twisted state for a certain period of time are due to the stress. In addition, a predetermined time is required before the operation according to the drive voltage is performed. Therefore, until the time elapses, the image that is displayed when the power is turned off is displayed as an afterimage, which is a so-called burn-in state, and an image that is difficult to see is displayed.

Further, when the liquid crystal molecules of the liquid crystal display element 27 are twisted, that is, when a direct current voltage is continuously applied, the liquid crystal molecules are deteriorated due to an ionization phenomenon or the like, and the liquid crystal display element 27 itself. It will shorten the life.

Therefore, it is conceivable to apply a driving voltage of 0 V to the liquid crystal display element 27 when the power is off to remove the twist of each pixel and then stop the display. That is,
In a normal TFT liquid crystal display element, it is possible to prevent the image sticking phenomenon by turning on all the TFT transistors and applying a drive voltage of 0V. However, PAL
In C20, if the display is stopped in this way,
It is necessary to simultaneously perform plasma discharge in all the scanning grooves 23. If plasma discharge is simultaneously performed in all the scanning grooves 23, a power supply circuit having a current amount of, for example, several tens of amperes is required. Therefore, by installing a large capacity power supply circuit, the weight of the display device increases and
There is a problem that miniaturization is hindered.

[0020]

The present invention has been made to solve the above problems, and includes a first scanning electrode group disposed on a first surface of a liquid crystal display element and the liquid crystal. A plasma addressed liquid crystal display device provided with a second scan electrode group which is arranged to face the second surface of the display element and is formed in plural in a direction orthogonal to the first scan electrode group to form a plasma discharge channel. In the above, a power storage unit is provided in the power source of the drive circuit for applying the scanning voltage to the second scan electrode group, and when the power source of the plasma addressed liquid crystal display device is turned off, the first scan electrode group A plasma-addressed liquid crystal display device is configured in which the driving voltage is set to 0 and the scanning voltage is controlled to be supplied to the second scanning electrode group for at least one field period.

According to the present invention, the burn-in prevention circuit for applying 0 V to the liquid crystal display element when the power is turned off can easily and inexpensively realize the burn-in prevention, and the display device can be constructed at low cost. Will be able to.
As a result, when the power is turned off, the liquid crystal display element is, for example, normally white (all white ... twist of liquid crystal molecules at 90 degrees) or normally black (all black ... no twist of liquid crystal molecules).
This makes it possible to prevent the burn-in phenomenon of the display device and to display a good image when the power is turned on.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the display device according to the present invention will be described. FIG. 1 is a diagram showing a partial circuit block of a display device, particularly a video system, in which a plasma addressed liquid crystal display element of the present embodiment is configured as a display unit. The plasma addressed liquid crystal display element is the PAL described in FIG.
It has the same structure as C20.

Although not shown in the figure, this display device has an NT
In front of the SC (National Television System Committee) demodulation unit 1, for example, an NTSC U / V tuner, a B
A broadcast receiving means such as an S tuner and one or a plurality of input terminals for inputting a standard video signal reproduced by an external device such as a VTR are provided. The standard video signal selected by the broadcast receiving means and the external standard video signal input from one or a plurality of input means are selected and input in the display device and input to the NTSC demodulation unit 1. Become.

NTSC (National Television System C)
The demodulation unit 1 demodulates the luminance signal and the color difference signal and supplies them to the double speed conversion unit 2. In addition, the synchronization signal extracted here is supplied to a control unit 14 described later, and the control unit 14 generates an operation clock of each functional circuit described below to synchronize various signal processes. . A frame memory capable of storing one frame of video signal (luminance signal, color difference signal) is provided in the double speed conversion unit 2, and a motion component is detected by the frame memory. Then, in the still image area, the video signal of the field at that time point and the one horizontal period before the one field is continuously read twice at a speed twice that at the time of reading. In the moving image area, the video signal of one horizontal period of the field information at that time and the interpolated video signal generated by the interpolation processing using the video signals of one horizontal period above and below the same are read at double speed, and are read at 525H / 60Hz. Is converted to a non-interlaced signal.

The video signal that has been subjected to the double speed processing is subjected to color adjustment, hue adjustment, etc. in the video signal processing section 3, and then R, G and B primary color signals are generated by inverse matrix processing. . Each of the primary color signals generated here is converted into digital video data V8b by an A / D converter 4 having an 8-bit quantization precision, and further equivalently converted by a frame rate conversion unit 5 into 8 bits. It is converted into 7-bit video data V7b having considerable accuracy. The video data V7b (R color, G color, B color) is supplied to the liquid crystal column driver 7 after being subjected to white balance processing by the white balance adjusting section 6.

The liquid crystal column driver 7 has video data for one horizontal period (for example, 768 pixels), that is, 768 pixels ×
3-channel (R color, G color, B color) pixel (for example, 23
The video data V7b of 04 pixels) is latched and the video data V7b of each pixel is held for one horizontal period. Then, when a plasma discharge is generated in a predetermined scanning groove 23 by a plasma driver 11 which will be described later, it is read out every horizontal line and further converted into an analog signal by the D / A converter 8 to be respectively driven by the drive electrodes 2 of the PALC 20.
It is applied to 9R, 29G, and 29B.

The LCD controller 9 is configured to operate with a power supply of about 7 V, for example, and a count clock for driving the S-shaped correction waveform generating section 10 by an operation clock generated based on a synchronizing signal, and a plasma driver 11
Is driven to generate a plasma pulse for plasma discharge for each scanning groove 23 (horizontal line). The count clock is supplied to the S-shaped correction waveform generation unit 10 to generate an S-shaped correction waveform for controlling the drive rate according to the transmittance characteristics of the liquid crystal molecules that are pixels. Then, this S-shaped correction waveform is supplied to the liquid crystal column driver 7, and S-shaped correction (γ correction) is applied to the image data V7b which has undergone the white balance processing.

The LCD controller 9 has a plasma power supply charging circuit 16 as shown in FIG. 2, for example.
A power supply of about 7V is supplied via the. The plasma power supply charging circuit 17 is composed of a charging circuit composed of a diode D1 and a capacitor C1 and a 5V regulator Rg as shown by the one-dot chain line. When the power supply of the display device is on, the plasma power supply charging circuit 17 is charged. A voltage for generating a plasma pulse of about 5 V is supplied via the circuit 17. When the power is turned off, the electric power stored in the capacitor C1 drives the LCD controller 9 and controls the plasma driver 11 for generating plasma pulses.

The plasma driver 11 shown in FIG.
In the present embodiment, about 450 constituting the NTSC effective screen
A horizontal scanning line corresponding to a line, that is, a scanning groove 23 formed in the PALC 20 is sequentially selected to supply a plasma pulse, and a voltage of about -300 V applied to the cathode 25 is applied.
A plasma discharge is generated by the power supply voltage. That is, in synchronism with the double-speed video data V7b inputted to the liquid crystal column driver 7, the scanning grooves 23, 23, 23 ... The liquid crystal display device 27 can be driven according to the image data.
As a result, the input video signal can be displayed as an image.

The plasma driver 11 is configured to operate at a power supply voltage of about -300 V in order to generate a plasma discharge. This power supply voltage is, as will be described later in detail in FIG. 3, a power supply voltage charging circuit. Are supplied through. Then, when the power is turned off, the power supply is continuously supplied from the power supply voltage charge circuit for at least one field. Therefore, after the power is turned off, plasma can be discharged by the power supplied from the power supply voltage charging circuit, and the liquid crystal display element 2
It becomes possible to apply a drive voltage of 0 V to 7.

The backlight 13 is arranged as a light source for illuminating the PALC 20 from the back side, and the luminous flux emitted here passes through a predetermined pixel of the liquid crystal display element 27 to form a display image. Further, picture adjustment can be performed by adjusting the brightness of the light source.

The control unit 14 generates the operation clock of each of the functional circuits from the synchronization signal input as described above to synchronize various signal processings, and according to the command input by the user from the operation unit 16, the above-described operation is performed. The tuner is configured to perform tuning, image adjustment, and various controls such as power on / off.

Hereinafter, the plasma driver 1 will be described with reference to FIG.
1 will be described in detail. A power supply voltage of, for example, about -300 V is used for the plasma driver 11, and this is applied to each line (for example, the first line L1 to the 450th line L450 ... Effective scanning line number) via the power supply voltage charging circuit 18. Cathode 25 (1), 25 (2) ..., 25
Applied to (450). And cathode 25 (1 to 450)
Are connected to the drains of, for example, NMOS (N channel MOS) transistors Tr (1), Tr (2), ..., Tr (450) which are arranged as switching elements for plasma discharge.

The source electrodes of the NMOS transistors Tr (1 to 450) are commonly connected, and further, for example, about 100
It is connected to a current source of mA, and the current during plasma discharge is controlled to be constant so that stable plasma discharge is performed. In addition, LC is used for the gate electrode.
For example, a positive polarity pulse (plasma pulse) of about 10 μsec supplied from the D controller 9 is sequentially applied for each line. When a plasma pulse is applied to the gate electrodes of the NMOS transistors Tr (1 to 450), plasma discharge is generated between the anode 24 (1) and the cathode 25 (1) as indicated by hatching in the first line L1, for example. Occur. That is, by sequentially applying the plasma pulse to the gate electrodes from the first line L1 to the 450th line L450 in synchronization with the pixel signals for one line, an image for one field can be formed.

In the present invention, the power supply voltage charging circuit 18 for storing the operating power supply power of the plasma driver 11 indicated by the alternate long and short dash line is arranged for the power supply voltage of -300V. The power supply voltage charging circuit 18 includes a current limiting resistor R1 for inrush, a capacitor C2 for charging,
Also, a discharge diode D2 for reducing the impedance when discharging the capacitor is connected in parallel.

When the power is turned on, the charging capacitor C2 is gradually charged through the current limiting resistor R1, and after the power is turned off, the electric power charged in the capacitor C2 is used as an operating power source for plasma discharge. At least 1 as voltage
NMOS transistor Tr (1 ~
450), the stable plasma discharge necessary for driving the liquid crystal display element 27 can be continued. The capacity of the capacitor C2 is set so that plasma discharge can be generated in the scanning groove 23 for at least one field (450 lines) period after the power is turned off. Therefore, since the discharge scanning state can be continued for at least one field even after the power is turned off, the driving voltage of 0V is applied to the liquid crystal display element 27 during the plasma discharge period (at least one field or more). By applying the voltage, it is possible to form an all-white screen after the power is turned off and prevent the electric charge from remaining.

Next, the relationship between the drive signal of the liquid crystal display element 27 and the plasma pulse will be described. FIG. 4 is a diagram showing the timing of two lines of each drive signal when an image is displayed when the power is turned on. FIG. 4A shows the drive signal (analog) of the liquid crystal display element 27 which is the output of the liquid crystal column driver 7. Converted video signal), FIG. 4 (b) shows an NMOS transistor T
Plasma pulse applied to the gate electrode of r, FIG.
(C) schematically shows a waveform of the power supply voltage of −300 V applied to the cathode 25.

The scanning period for one line is, for example, 32 μsec.
4B and 4C, a positive plasma pulse having a width of 10 μsec is applied to the NMOS transistor Tr (1) corresponding to the first line L1 to discharge plasma at the timing shown in FIGS. The maximum of 60 samples and held for each pixel shown in FIG.
By continuously applying the V image signal for about 20 μsec, for example, an image for one line can be written in the liquid crystal display element 27.

Then, in the subsequent second line L2, as shown in FIG.
(D) As shown in (e), as shown in FIG. 4 (a), the NMOS transistor Tr (2) is applied with a positive-polarity plasma pulse having a width of 10 μsec and plasma-discharged. Then, the video signal (inversion data) of the second line of maximum −60 V sampled and held for each pixel is continuously applied for, for example, about 20 μsec. That is, the liquid crystal display element 27 is driven by an alternating voltage by performing the inverted output for every odd line and even line, and the deterioration of the liquid crystal molecules due to the continuous application of the direct voltage is prevented.

At such timing, the video signals for 450 lines are sequentially written in the liquid crystal display element 27,
An image for one field can be formed and displayed.

By the way, when the power is turned off during image display as shown in FIG. 4, the liquid crystal display element 2 is used to prevent the burn-in phenomenon as described above.
It is necessary to apply a drive voltage of 0 V to 7 and to sequentially perform plasma discharge for each line.

FIG. 5 is a timing chart showing the timing when plasma discharge for one field is performed after the power is turned on. 5A is a power supply voltage level of the plasma driver 11, FIG. 5B is a power supply voltage level of the liquid crystal column driver 7, FIG. 5C is a video signal corresponding to FIG. 4A, and FIG. d) is shown in FIG.
5E shows the waveform of the plasma pulse sequentially applied to the gates of the NMOS transistors Tr (1 to 450) after the power is turned off.

As shown in these figures, in the case of the present invention, the power is turned off (Pof) in the middle of the third line, for example.
f), as shown in FIG. 5 (c),
After the power is turned off Poff, a driving voltage of 0 V is applied to the liquid crystal display element 27 for a period of, for example, one field (450 lines). Then, as shown in FIG. 5A, the power supply voltage charging circuit 18 supplies −300V to the plasma driver 11 during the period of power off (Poff) and at least one field thereafter. Keeps the operating state.

Then, the LCD controller 9 uses the electric power obtained from the plasma power supply charge circuit 17 shown in FIG. 2 to sequentially generate plasma pulses of the NMOS transistors Tr (1 to 450) at the timing shown in FIG. Apply to the gate. As a result, the plasma discharge for one field is about 16.9 msec (32 μsec x 525 lines).
Will be able to be done over a period of. While the plasma discharge is sequentially performed in this manner, the driving voltage of 0 V is applied to the driving electrodes 29 (G, B, R) as shown in FIG. 0V can be applied to all the pixels of the liquid crystal display element 27 forming the scanning line of the line L450, and the residual charge after the power is turned off can be eliminated. Since the backlight is turned off after the power is turned off, the power off point Poff
Subsequent driving states of the liquid crystal display element 27 are not displayed on the monitor.

As described above, by providing the power supply voltage charging circuit 18 for plasma discharge, the electric power stored when the power is turned on can be used to sequentially perform the plasma discharge in the period of at least one field after the power is turned off. become. As a result, a voltage of 0 V can be applied to each pixel of the liquid crystal display element 27, and no voltage is applied while the power is off, that is, the liquid crystal molecules have a twist angle of about 90 °. It is possible to obtain a mari-white state, suppress the ionization phenomenon of liquid crystal molecules, and prevent the image sticking in which a past image is displayed when the power is turned on. Since the backlight is turned off after the power is turned off, the driving state of the liquid crystal display element 27 after the power off point Poff is not displayed on the monitor.

By the way, in the above embodiment, when the power is turned on,
And after turning off the power, the horizontal scanning period for one line is about 32μ.
Although described as sec, by setting one horizontal period after power-off to, for example, 10 μsec, it becomes possible to perform high-speed scanning about three times as shown in FIG. 5 (f).
Plasma discharge for one field may be performed by a high-speed scan of 5.6 msec (16.8 msec / 3). As described above, by shortening the plasma discharge time for one field, the capacity (time constant) of the charging capacitor C2 for charging the power supply voltage of -300V which is the operating power supply of the plasma driver 11 shown in FIG. 5A. Can be reduced to about 1/3 of that in the normal scanning shown in FIG. 5E, and the cost of the circuit can be reduced.

[0047]

As described above, in the display device of the present invention, the power of the plasma driver is gradually charged when the power is turned on in order to write 0V power to the liquid crystal display element when the power is turned off. A power supply voltage charging circuit consisting of a built-in capacitor is provided. Since this power supply voltage charging circuit has a simple circuit configuration including a charging capacitor, it is possible to prevent burn-in of the liquid crystal display element at low cost without providing another new power supply. This makes it possible to prevent a part of the previous image from being displayed at the same time the next time the power is turned on and the image is displayed.In addition, the power is turned off. There is an advantage that it is possible to prevent an ionization phenomenon and the like of the liquid crystal display element due to the residual charge afterwards.

[Brief description of drawings]

FIG. 1 is a diagram showing a block diagram of a display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a circuit constituting a plasma pulse voltage charging means of the LCD controller of the display device of the present embodiment.

FIG. 3 is a diagram showing a circuit constituting a plasma driver of the display device of the present embodiment.

FIG. 4 is a diagram showing a timing chart showing drive signals of a liquid crystal display element and a plasma driver when an image is displayed when the power is turned on.

FIG. 5 is a diagram showing a timing chart showing drive signals of a liquid crystal display element and a plasma driver at the time of power-on, at power-off, and after power-off.

FIG. 6 is a perspective view showing a part of PALC.

FIG. 7 is a diagram schematically showing a switching operation of PALC.

FIG. 8 is a diagram equivalently showing a switching operation of PALC.

[Explanation of symbols]

9 LCD driver, 11 Plasma driver, 17
Plasma power supply charge circuit, 18 power supply voltage charge circuit, 20 PALC

Claims (3)

[Claims] 1. A first scanning electrode group disposed on a first surface of a liquid crystal display element, and a first scanning electrode group disposed so as to face a second surface of the liquid crystal display element. In a plasma addressed liquid crystal display device having a second scan electrode group forming a plurality of plasma discharge channels in a direction orthogonal to each other, electric power is stored in a power source of a drive circuit for applying a scan voltage to the second scan electrode group. Means for setting the drive voltage of the first scan electrode group to 0 when the power source of the plasma addressed liquid crystal display device is turned off, and at least 1 for the second scan electrode group.
A plasma-addressed liquid crystal display device, which is controlled so that a scanning voltage is supplied over a field period. 2. The plasma addressed liquid crystal display device according to claim 1, wherein the power storage means is composed of a capacitor charged through a resistor. 3. The first scan electrode group is set to have a speed higher than a scanning speed with the power supply turned on immediately after the power supply is turned off. 2. A plasma addressed liquid crystal display device according to item 2.