KR20000065836A - Apparatus of Plasma Address Liquid Crystal Display - Google Patents

Abstract

PURPOSE: A plasma address LCD is provided to prevent error discharge and mis-discharge by disposing cathodes in positions farther than anodes from a dielectric film. CONSTITUTION: A plasma address LCD comprises a bottom substrate(54), cathodes(K), ribs(50), anodes(A) and a dielectric film(52). The cathodes(K) are disposed on the bottom substrate(54). The anodes(A) are disposed on lower inclined surfaces of the ribs(50) with a constant distance from the bottom substrate(54) in vertical direction. The cathodes(K) are disposed in positions farther than the anodes from the dielectric film(52). It is preferable that the ribs be formed by etching process.

Description

Plasma Address Liquid Crystal Display {Apparatus of Plasma Address Liquid Crystal Display}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel display, and more particularly, to a plasma address liquid crystal display configured to prevent mis-discharge and miss discharge.

Recently, a liquid crystal display (hereinafter referred to as "LCD"), a field emission display (hereinafter referred to as "FED") and a plasma display panel (hereinafter referred to as "PDP") Such flat display devices are being actively developed. Among them, a plasma address liquid crystal display device (hereinafter referred to as " PALC ") and a PDP are attracting attention because they have excellent brightness and image quality and are advantageous for being larger than 40 inches.

Referring to FIG. 1, a conventional PALC includes a backlight unit, a plasma unit, and a liquid crystal unit. PALC uses plasma discharge like PDP, but differs from PDP in discharge conditions. The biggest difference is that the discharge area is different in size. For example, the discharge area of the PDP is the pixel area and the discharge area of the PALC is the scan line area. That is, it can be seen that the discharge area of the PALC is thousands of times larger than the discharge area of the PDP. As such, since PALCs generate discharges per scan line, it is very important to generate uniform and stable discharges. Detailed description thereof will be described later.

The backlight unit 10 supplies light beams to the plasma unit and the liquid crystal unit. In addition, the plasma unit includes a first polarizing plate 22 attached to the lower substrate 24 to face the backlight unit 10, an anode A and a cathode K formed side by side on the lower substrate 24, and A partition wall 34 formed vertically on the lower substrate 4 and a dielectric film 36 formed on the partition wall 34 to accumulate electric charges are provided. The partition wall 34 divides each discharge cell. At this time, a pair of the positive electrode (A) and the negative electrode (K) are arranged in one discharge cell and filled with discharge gases such as He and Ne. The plasma unit serves as a switch element for changing the arrangement of the liquid crystal using the virtual electrode formed by the plasma discharge. In other words, the plasma unit performs a function of a switch element that is the same as a thin film transistor (“TFT”) of an LCD. In addition, part of the space charge formed by plasma discharge is accumulated in the dielectric film 36 provided on the partition wall 34. The liquid crystal module includes a liquid crystal layer 26 formed on the dielectric layer 36, a transparent electrode (ITO) 38 formed on the liquid crystal layer 26, and a color filter formed on the transparent electrode 38. A color filter 28, an upper substrate 30 formed on the color filter 28, and a second polarizing plate 32 attached to the upper substrate 30. The first and second polarizers 22 and 32 change the polarization characteristics of the light beam. In addition, the liquid crystal layer 26 adjusts the transmission amount of the light beam in response to an image signal applied according to the capacitance partial pressure ratio of the dielectric layer 36 and the liquid crystal layer 26. At this time, a color filter of red (hereinafter referred to as "R"), green (hereinafter referred to as "G"), and blue (hereinafter referred to as "B") is formed on the transparent electrode 38. To achieve the desired color.

Meanwhile, the operation principle of the PALC will be described in detail with reference to FIG. 2. As shown in FIG. 2, when 0 V is applied to the anode A disposed in the discharge cell and −350 V is applied to the cathode K, plasma discharge occurs. In this case, the inside of the discharge cell has the anode potential except for the vicinity of the cathode k by the charged particles 42 formed by the plasma discharge. Accordingly, the plasma switch 44 is turned on to form a virtual electrode 40 in which the anode A is electrically shorted. That is, when the plasma discharge occurs, the virtual electrode 40 is formed to have a short state with respect to the anode. On the other hand, when the plasma discharge does not occur, since the plasma switch 44 is turned off and the virtual electrode 40 is not formed, the plasma switch 44 is open to the anode. In addition, when an image signal is applied to the transparent electrode 38 during the discharge period (that is, when the virtual electrode is formed), the potential difference due to the capacitance partial ratio of the insulating layer 36 and the liquid crystal layer 26 is changed to the liquid crystal layer 26. To occur to change the arrangement of the liquid crystal to control the transmission amount of the light beam. As such, the plasma discharge inside the discharge cell performs the switching operation, and as a result, serves to control the light beam transmission amount of the liquid crystal unit. In other words, the plasma portion of the PALC performs the same function as the TFT of the LCD. In addition, since the state is maintained in the discharge cell even in the non-selection period in which discharging is stopped, the state of the liquid crystal can be memorized. Accordingly, the PALC displays the screen corresponding to the image signal by changing the arrangement of the liquid crystal using the virtual electrode 40 formed by the plasma discharge.

Referring to FIG. 3, a conventional PALC electrode structure is shown. A plurality of discharge cells are provided between the first to n-th partition walls 34a to 34n formed vertically on the lower substrate 24. A pair of the cathode K and the anode A are arrange | positioned at the said discharge cell. In this case, as shown in FIG. 4, the distance between the cathode K and the dielectric film 26 disposed in the partition 34 and the distance between the anode A and the dielectric film 26 are arranged to be the same. As a result, since space charges having a positive potential formed by discharge accumulate in the dielectric film, there is a problem that mis-discharge or miss discharge occurs between the dielectric film and the cathode K.

Accordingly, an object of the present invention is to provide a plasma address liquid crystal display device configured to prevent mis-discharge and miss discharge.

1 is a perspective view showing a conventional PALC structure.

2 is a view for explaining the operation principle of the PALC.

3 is a diagram illustrating an electrode configuration of FIG. 1;

4 is an enlarged view of a portion A of FIG. 3;

5 illustrates a PALC electrode structure of the present invention.

<Description of the code | symbol about the principal part of drawing>

10: backlight 22, 32: polarization filter

24: lower substrate 26: liquid crystal

28: color filter 30: upper substrate

34,50 bulkhead 36,52 dielectric film

38: transparent electrode 40: virtual electrode

42: charged particle 44: plasma switch

In order to achieve the above object, the plasma address liquid crystal display of the present invention includes a plasma unit having a cathode disposed on a lower substrate and an anode disposed on a lower inclined surface of the partition wall at a predetermined distance from the lower substrate in a vertical direction.

Other objects and features of the present invention other than the above object will become apparent from the description of the embodiments with reference to the accompanying drawings.

A preferred embodiment of the present invention will be described with reference to FIG. 5.

5, the electrode structure of the PALC of the present invention is shown. PALC of the present invention has a cathode (K) disposed on the lower substrate 54, and the anode (A) disposed on the lower inclined surface of the partition wall 50 at a certain distance in the vertical direction from the lower substrate 54 It is provided with a plasma part. In this case, the functions and operations of the backlight unit (not shown) and the liquid crystal unit (not shown) are sufficiently described in FIGS. 1 and 2, and thus, detailed descriptions thereof will be omitted. On the other hand, PALC according to the present invention will have a different electrode arrangement than the conventional PALC to prevent mis-discharge and miss discharge. As shown in FIG. 5, the position of the cathode K in one discharge cell is spaced farther from the dielectric film 52 than the position of the anode A to prevent mis-discharge and miss discharge. To this end, the cathode (K) is disposed on the lower substrate 54, the anode (A) is positioned above the cathode (K) and is disposed on the lower inclined surface of the partition 50 that does not transmit light. In this case, the partition 50 is preferably formed by etching. Accordingly, the PALC of the present invention prevents mis-discharge and miss discharge and improves light efficiency.

As described above, the plasma address liquid crystal display device according to the present invention has the advantage of preventing mis-discharge and mis-discharge during plasma discharge and also improving light efficiency.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (3)

A plasma address liquid crystal display device for driving a liquid crystal by applying a voltage to an anode and a cathode in a discharge cell isolated by a partition wall, thereby causing a plasma discharge. And a plasma unit having a cathode disposed on a lower substrate and an anode disposed at a lower inclined surface of the barrier rib at a predetermined distance from the lower substrate in a vertical direction. The method of claim 1, And the anode and the cathode are arranged to have a different distance from the dielectric layer on the barrier rib. The method of claim 1, And the anode is disposed in a region where the light beam is not transmitted.