JPH0721929A - Plasma display panel - Google Patents

Abstract

(57) [Summary] [Objective] To provide a PDP which is highly efficient and can be applied to the formation of fine display cells. [Composition] A plasma display panel in which a front glass plate and a back plate are overlapped with each other and the periphery is hermetically sealed to form a discharge gas storage container, wherein a display discharge space, a discharge selection space, and a positive column are formed in a flat shape The three layers of the sustain space divide the gas space sequentially from the front glass plate toward the back plate, and the display discharge space and the discharge selection space are composed of a plurality of display cells and selection cells arranged in a matrix. The plane direction is separated by a partition wall, and the vertical direction is divided by a first separation plate having a communication hole corresponding to each cell at a ratio of 1: 1. The positive column maintaining space and the selected cell are small holes corresponding to each selected cell. The display electrode formed in the display cell and the selection electrode formed in the vicinity of the communication hole in the selection column or the positive column maintaining space are connected in a line shape. Two electrode groups The plasma display panel, wherein at least one pair of sustain electrodes is formed in the positive column sustain space.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat type plasma display panel having a large number of display cells.

[0002]

2. Description of the Related Art Plasma display panels (hereinafter referred to as P
Various types are known for abbreviated as DP), but in order to be thin, a structure in which a front glass plate and a back plate are overlapped to hermetically seal the periphery and display cells are arranged in a planar matrix is a prize. To be done. A cathode and an anode are arranged in each display cell, but they are formed as two linear electrode groups for ease of formation and matrix driving. A large number of display cells are arranged at positions where these electrode groups are separated by a predetermined distance and intersect each other when viewed from the display surface. It should be noted that the cathode and the anode are defined in the DC drive, but in the AC drive, two electrodes are used by being interspersed with the cathode and the anode.

The display color is a single color P for seeing the emission color of the discharge gas.
There are a DP and a color PDP that causes a phosphor to develop a color by ultraviolet rays generated by discharge.

The type utilizing glow discharge for display is advantageous in forming fine display cells and thinning because the distance between electrodes is short. However, since the cathode drop voltage is high, the drive voltage is also high, and a device having a high luminous efficiency has not been realized.

The type utilizing positive column discharge can be expected to have a large luminous efficiency because the voltage drop in the positive column portion is small. However, since a discharge space other than the positive column generation portion is also required, the distance between the electrodes is required to be at least about 2 mm. This is because the longer the positive column is, the larger the light emission efficiency is, and therefore the large efficiency cannot be expected with an electrode distance smaller than 2 mm.
Therefore, it is more difficult to form a fine display cell in a PDP having a higher efficiency. It is conceivable to form electrodes in the direction perpendicular to the screen to miniaturize them. However, in order to prevent erroneous discharge with adjacent cells and to support the pressure difference between the inside and outside of the panel, the display cells require partition walls. In a display cell having a small area, the partition wall width must be reduced so as not to reduce the aperture ratio. That is, the larger the depth, the more difficult it is to form the partition wall, which is contrary to the thin shape. Also, because the cathode is formed in each cell,
Although it is highly efficient, it is difficult to adopt a hot cathode that requires heat separation. This is because it takes a lot of time and effort to form, and the power consumption due to discharge loss becomes considerable.

Under these circumstances, conventional PDP's having high luminous efficiency and fine display cells have not been realized. The actual situation is that the color PDP in which the high efficiency is not sufficiently achieved is particularly problematic.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to solve these problems of the prior art and to provide a PDP which is highly efficient and can be used for forming fine display cells.

[0008]

The above object of the present invention is achieved by the following PDP.

That is, the present invention is a PDP in which a front glass plate and a rear plate are overlapped with each other and the periphery thereof is hermetically sealed to form a discharge gas storage container, each of which has a flat display discharge space and a discharge selection space. The three layers of the positive column maintaining space divide the gas space sequentially from the front glass plate toward the rear plate, and the display discharge space and the discharge selection space are composed of a plurality of display cells and selection cells arranged in a matrix, The plane direction of each cell is separated by a partition wall, and the vertical direction is divided by a first separation plate having a communication hole corresponding to each cell at a ratio of 1: 1. The positive column maintaining space and the selected cell correspond to each selected cell. The display electrode formed in the display cell and the selection electrode formed in the vicinity of the communication hole in the selection cell or the positive column maintaining space are linearly connected by the second separation plate having the small holes. Two electrodes connected Configure, the positive column maintained space, characterized in that at least one pair of sustain electrodes are formed P
It is DP.

The present invention will be described in more detail. Although the following description will be given for a color PDP having strict characteristics and complicated formation, of course, a single-color PDP can be more easily implemented.

[0011]

EXAMPLES The present invention will be specifically described below based on examples.

FIG. 1 is a schematic partial sectional view showing an example of the PDP of the present invention. In the following figures, the same reference numerals denote the same items.

The front glass plate FG and the back plate BP are faced to each other, and a side plate (not shown) surrounding the periphery is sandwiched to form a gas container. Each face plate is hermetically sealed with a sealing material such as low melting glass. The side plate is also used as a sealing material or other member and is often omitted. An exhaust pipe is usually attached to the exhaust hole formed in the back plate or the side plate (all are omitted), gas is filled after exhaust, and the exhaust pipe is chipped off to complete the PDP.

As the discharge gas, H which emits ultraviolet rays is used.
g, Xe, N ₂ or the like alone or He, Ne, A
It is mixed with a rare gas such as r or Kr and sealed. In the present invention, since the distance between the sustain electrodes can be increased regardless of the size of the display cell, even if Hg having a low vapor pressure is used, it can be set in the saddle portion of the Paschen curve, and low voltage driving is possible. H
g is the gas with the highest ultraviolet radiation efficiency.

As the front glass plate, transparent and inexpensive soda lime glass for windows is favored. Glass, ceramics, metal, etc. can be used as the back plate and the side plate. Since various thermal processes are adopted in PDP, the thermal expansion of each member is selected to be similar.

The discharge gas space is divided into three flat layers, which are a display discharge space DS, a discharge selection space AS, and a discharge sustaining space MS (hereinafter abbreviated as display space, selection space, and sustaining space) in order from the top. Has been done. The display space is divided into display cells arranged in a matrix, and the selection space is divided into selection cells corresponding to the display cells in a 1: 1 manner in the plane direction by partition walls PW. The vertical direction of each space is divided by a first separation plate S1 and a second separation plate S2, and a through hole TH formed in the separation plate.
Is communicated with. Further, since the maintenance space does not need to be divided, it is connected to a plurality of selected cells.

Display electrodes D are formed in the display cells and are connected in a vertical line. Although it is formed on the front glass plate in the figure, it may be formed on the first separating plate or the partition wall.

The phosphor PH of each color is applied to the inner surface of the display cell. In the coating as shown in FIG. 1, the light emission of the phosphor is directly observed, and it is classified as a reflection type. When it is applied to the front glass plate, it looks through the phosphor and is classified as a transmission type. A mixed type of both may be used. The brightness can be increased by applying a phosphor to the selected cell at a position visible from the display surface. To increase the phosphor coating area,
The area of the display electrode and the communication hole should be the minimum required. The formation position is such that the positive columns are spread over the entire surface of the cell. When the cell width is large and the positive columns do not spread, it is advisable to provide partition walls in the cells to bend the positive columns in a plane.

The selection electrode A is connected in a line in a parallel direction, bypassing the through hole, and unnecessary portions are covered with the dielectric DL. The function of the selection electrode is to control the positive column maintained in the sustain space as a path leading to the display cell. The position that can be easily controlled is the maintenance space inside the selected cell and in the vicinity of the communication hole. Therefore, the formation location is the first
The lower surface of the separating plate, the upper and lower surfaces of the second separating plate, and the partition wall.

It is easy to form the display electrodes, the selection electrodes, and their connections on a flat plate. This is because thin film and thick film technologies can be applied and many can be formed at the same time. A wide range of materials such as Al, Ag, Au, Ni and C can be used as the electrode material. A coated electrode coated with a dielectric can also be used. As the coating material, various dielectrics can be used, and if glass is used, a dense material can be obtained and formation is easy.

Glass, ceramics, metals, etc. can be used as the material for forming the partition walls and the separating plate, and various forming methods are known. However, it is convenient to use a metal plate to process a thin partition plate having a small width and a large number of communication holes. Since metal has good strength and workability, it has high precision and operability. For example, etching can be used to process many cells at the same time. Although four metal plates are used in FIG. 1, since the metal can block light such as ultraviolet rays, light from the maintenance space and the selected cell is cut off, and unnecessary light emission of display is prevented. When forming a circuit such as an electrode on these metal plates, it is advisable to cover and insulate a necessary portion with a dielectric such as glass. Printing or electrodeposition can be easily used as the covering means. By using different etching resist patterns on the front and back sides, it is possible to form one partition wall and separator plate shape from one metal plate. Therefore, the structure as shown in FIG. 1 can be formed with two metal plates. In addition, if the partition walls are high and the display cell area is small, it may be difficult to form a single metal plate. In this case, a plurality of metal plates may be used for stacking. further,
When the display screen is very large and it is difficult to process with one metal plate, it is possible to arrange a plurality of metal plates in a plane.

A positive column is maintained in the maintenance space connected to the selected cell by a communication hole. Since another discharge space is formed between the sustain electrode (particularly the cathode) and the positive column, the sustain electrode and the communication hole are formed separately. Since the sustaining space may be an integral space, at least one pair of sustaining electrodes is required. Either a hot cathode or a cold cathode can be adopted as the cathode of the sustain electrode.

Since the positive column in the sustain space is distributed to many cells, a sufficient amount of ions is required. When the number of ions is small, the number of display cells selected is likely to change. Since the necessary ions increase as the display cell becomes thicker, the thickness is preferably 1.5 times or more the display cell thickness. If it exceeds 3 times the thickness of the display cell, the reactive power increases and the thinness can be prevented. However, in order to maintain high discharge efficiency and a wide range of positive columns, it is practical in terms of formation that the maintenance space has a thickness of about 1 to 35 mm. As described above, the thickness of the maintenance space is influenced by the thickness of the display cell, and therefore it is desirable to design in this range.

The sustain electrodes may be directly driven, or may be intermittently driven, for example, in a pulse shape. In the case of intermittent driving, display driving is performed in synchronization with pulses.

As described above, the positive column is preferably maintained in all the communication holes to the selected cell, but it may be partially not maintained. It is known that between the positive column and the anode, although the amount is small, energy is dissipated through the container wall, and the positive column is not maintained from the point where the energy became insufficient. However, since the energy difference is small in such a place, the same operation as in the case where the positive column is maintained is possible.

When the sustain electrode M is formed on the same plane as the sustain space. The position extends outside the screen. This schematic sectional view is shown in FIG. In order to form in the range of the screen, it is advisable to bend the end of the space and form the electrode under the maintenance space (FIG. 2 (b)). Although the back plate of this PDP is somewhat complicated, it is a device for arranging a plurality of panels to form a large screen with uniform pitch cells.

A long sustaining space requires a long cathode. However, with a long cathode, the discharge tends to be localized and the positive columns are uneven. This is especially the case with hot cathodes. In order to prevent uneven discharge, it is advisable to add resistors to the separately formed cathodes and drive them in parallel (FIG. 3). It is also possible to form partition walls in the maintenance space and form the elongated spaces in parallel (FIG. 4A) or in series (FIG. 4B).

As the maintenance space becomes wider, a spacer for supporting the pressure difference between the inside and outside of the panel is required. Since the communication hole may be small, the spacer can have a width close to the display cell width. Also, since it is not necessary for each cell, the number of spacers is small. Therefore, even a high spacer can be easily formed, and a wide range of materials and technologies can be selected. Next, driving will be described.

In the PDP of the present invention, the positive column is maintained in the maintaining space during the display period. Since this part is similar to a fluorescent lamp, it can be made very efficient. It is easy to form a large PDP. As the display screen becomes larger, the distance between the sustain electrodes becomes longer, the starting voltage becomes higher and the discharge start time becomes longer. To solve these problems, various starting circuits have been devised and can be used. In addition, a plurality of sustain electrodes may be formed so as to divide the screen in the length direction to shorten the discharge distance. The electrode formation in the middle of the screen is at the lower part of the maintenance space as shown in FIG. The sustain electrodes can be driven with either alternating current or direct current.

Two electrode groups of a display electrode and a selection electrode are arranged in an XY matrix and selectively driven. Line-sequential addressing can be performed by using one as a scanning electrode and the other as a data electrode.

For selective driving, display and selection voltage are turned on.
The levels are V _DH and V _AH respectively, and the OFF level is V
_DL and V _AL must be set. V _DH is not lit display when V _AL, a voltage to be turned when the V _AH, V _DL
Is a voltage that can be turned off even with V _AH . The larger the voltage difference between the ON and OFF levels, the higher the selectivity.

As a display selection, there is a method of changing the distance between the display electrode and the positive column. This is because the lighting voltage of the display increases as the distance increases.

The wall surface of the maintenance space is charged by the ions drifting from the positive column. The positive column in the sustain space hardly penetrates into the selected cell and the display cell because it is blocked by this charge and the communication hole is small. Although the positive column is regarded as a conductor, it has a substantially constant space potential Vp. Therefore, if a V _AH higher than Vp is applied to the exposed selection electrode, the positive column can be guided to the selected cell. On the contrary, it can be blocked by V _AL which is the same as or smaller than Vp. In the coating type selection electrode, V _AH is supplied as pulse polarity to cancel the electric charges accumulated in the dielectric surface, V _AL
If Vp is approximately equal to Vp, entry and blocking of the positive column can be controlled.

As another selection method, there is a method of controlling with an electric field. This is because the display lighting voltage changes by changing the voltage applied to the selection electrode. In this case, V _AH and V _AL are both set to voltages at which the positive column is not introduced into the selected cell. Both exposed and covered electrodes can be applied.

Although line-sequential driving can be performed with the above voltage setting, this driving reduces the brightness as the number of scanning lines increases. Memory driving is known to solve this problem. In this case, the display voltage setting becomes a little complicated. Since it is the display cell that is memorized, the display electrode is the scanning electrode,
The selection electrode becomes the data electrode. A sustain level V _DM is set between V _DH and V _DL . V _DM is V
_It is a voltage that maintains lighting regardless of _AH and V _AL , and is a value that does not light even at V _AH when not lighting. Since there is a difference between the discharge start voltage and the sustain voltage in the discharge phenomenon, such a setting is possible. A pulse voltage having a short interval is applied to the coated display electrode during the sustain period.

FIG. 5 shows a time chart of the memory operation. D is a display electrode, A is a selection electrode, and the subscript indicates a line number. 1H is one display cycle. An erasing signal is inserted immediately before the sequentially applied scanning signal.
In the figure, the cell of (D ₁ , An) is turned on by the data signal of An, and the other cells are not turned on. This state is maintained by the sustain level of the display electrodes.

Vp has almost the same potential in the positive column space, but has a slight potential gradient depending on the distance from the cathode. Since the display and selection voltages are considered based on Vp, even if a constant voltage is applied to the line, the voltage applied to each cell has a different value. These voltage differences reduce the selection range, but this effect is clear in the sustain electrodes driven by DC. In this case, the following method may be adopted.

Wiring resistance is given to the line connection in the sustain electrode direction. If the input is on the anode side and the wiring resistance (for example, several Ω / cm) is sufficient to cancel the potential gradient of the positive column, a constant voltage can be applied to each cell. In the line in the direction orthogonal to the sustain electrode, a resistance for canceling the positive column potential gradient is added to the input side. Since the potential gradient is small,
Small resistances are sufficient. The latter is a little complicated work, but can be omitted. As will be described below, a PDP may use a current limiting resistor, and this resistor uses a much larger value (for example, several hundred KΩ). Therefore, if the line to which the limiting resistance is added is a line orthogonal to the sustain electrode, it is possible to drive by ignoring the potential gradient difference of the positive column.

In the PDP, a load is used to prevent current runaway. The exposed electrode requires a limiting resistance, and the formation location varies depending on the driving method. A resistance is formed for each data line in the line-sequential drive, and for each cell in the memory drive. Since the capacitance of the coated dielectric serves as a load in the coated electrode, it is not necessary to separately form it. Since the capacitive load is formed in each cell, simple pulse driving may be performed regardless of the driving method. Various types of these circuit configurations are known. In a PDP, a dividing resistor may be used to obtain a plurality of potentials from one power source. The above resistors may be formed separately from the PDP in some cases, but can be easily integrally formed by using a flat substrate such as a front glass plate or a separating plate.

Each of the above-mentioned drive voltage widths is preferably small from the viewpoint of power consumption, and is preferably large from the viewpoint of control. However, in any case, since the voltage width around the space potential Vp of the positive column is sufficient, it is not necessary to drive beyond the cathode drop portion. That is, the selective drive power may be relatively small.

In order to increase the controllability of the panel structure, (1) the thickness and width of the selected cell and the diameter of the communicating hole are reduced. For example, about 0.05 to 1 mm is preferably exemplified. Alternatively, it is 1/5 to 1/2 of the display cell thickness. It is to be noted that one communicating hole connecting the two spaces is required for each cell, but a plurality of holes may be formed. (2) Increase the distance between two communication holes connected to the display cell and the maintenance space and the distance between each communication hole and the display electrode and the selection electrode. In order to increase the length of a limited cell area, it is advisable to provide a partition in the cell so that the cell has a folded structure. (3) The selection electrode area may be increased.

Although a complicated structure is required to improve the controllability, fine cells can be used by using a metal plate. For example, a PDP having a minimum arrangement pitch of 0.1 mm can be obtained. Further, since the partition wall width can be reduced, a display aperture ratio of 40% or more can be secured even with a minimum pitch of 0.5 mm or less. When the selection electrode is a scanning electrode in line sequential driving, the selection cell spaces in the line direction may be connected.

Although the description has been centered on the portions related to the present invention, it will be apparent that other publicly known techniques such as a forming method, a material and a forming technique can be applied.

[0044]

As is apparent from the above description, the present invention has the following effects.

(1) Since the display cell does not require a cathode, the phosphor coating area can be increased to achieve high brightness, and there is no influence of cathode sputtering, resulting in a long service life.

(2) The selective driving can be performed at a low voltage because it does not need to include the cathode drop portion. Therefore, the power consumption is small and the driving circuit can be inexpensive.

(3) Even if a hot cathode that operates at a low voltage is used as the sustain electrode, it is compact and consumes less power because there are only a few places where heat is separated.

(4) Since the gas pressure and the distance between the sustain electrodes can be optimally designed, the efficiency of maintaining the positive column is high.

(5) Since the discharge distance can be lengthened even in a small display cell, high efficiency Hg can be used even if the vapor pressure is low.

(6) Since a lot of positive column ions are present in the maintenance space, the time required for selection is very short.
Therefore, many cells can be driven in a short time.

(7) Since the display space, the selection space, and the maintenance space are formed in a plane, it is thin.

(8) Since the separating plate is used to divide each space, various circuits can be easily formed on this.

(9) Even in a PDP using a positive column, the use of a metal plate facilitates formation of fine cells.

[Brief description of drawings]

FIG. 1 is a partial schematic sectional view showing an example of a PDP of the present invention.

FIG. 2 is a schematic cross-sectional view illustrating an example of forming a sustain electrode.

FIG. 3 is a schematic plan view illustrating another example of forming sustain electrodes.

FIG. 4 is a schematic plan view in which a maintenance space is divided and formed.

FIG. 5 is a timing chart of memory driving used in the PDP of the present invention.

[Explanation of symbols]

FG: front plate, BP: back plate, D: display electrode, A: selection electrode, M: sustain electrode, DS: display space, AS: selection space, MS: sustain space, S1: first separation plate, S2: Second
Separator plate, TH: communication hole, PW: partition wall, PH: phosphor,
DL: dielectric.

Claims (3)

[Claims] 1. A plasma display panel in which a front glass plate and a back plate are overlapped with each other and the periphery is hermetically sealed to form a discharge gas storage container, wherein a display discharge space, a discharge selection space, each of which is formed in a planar shape, The three layers of the positive column maintaining space sequentially divide the gas space from the front glass plate toward the back plate, and the display discharge space and the discharge selection space are composed of a plurality of display cells and selection cells arranged in a matrix. The plane direction of the cells is separated by partition walls, and the vertical direction is 1: 1 for each cell.
1 is divided by a first separating plate having a corresponding communication hole,
The positive column maintaining space and the selected cell are sectioned and communicated with each other by a second separation plate having a small hole corresponding to each selected cell, and the display electrode formed in the display cell is communicated with the selected cell or the positive column maintaining space. The plasma display panel is characterized in that the selection electrodes formed in the vicinity of the holes are linearly connected to form two electrode groups, and at least one pair of sustain electrodes is formed in the positive column sustain space. 2. The plasma display panel according to claim 1, wherein the partition wall and the separation plate are formed of a metal plate having a through-hole shape corresponding to each cell and the communication hole. 3. The positive column maintaining space has a thickness of 1 to 35 m.
The plasma display panel according to claim 1, which is in the range of m.