KR20040071627A - Plasma display device provided with drive means suitable for carrying out rapid charge equalization operations - Google Patents

Abstract

PURPOSE: A plasma display device comprising a driver unit appropriate for performing a fast charge equalization operation is provided to reduce a sustain period of a discharge area reset operation as maintaining an equalization level of various discharge areas, without decreasing efficiency. CONSTITUTION: A discharge ignition threshold value does not exceed at a random cell of a panel without regard to charge state induced from an operation during a prior scan or sub scan before a step(P1), and a weak discharge begins to start at an area of the panel from the start of a condition setting step(P1). The discharge ignition threshold value exceeds at each cell of the panel after the condition setting step(P1) without regard to the charge state induced from the prior operation to generate initial condition setting state. Increasing rate of a potential between electrodes or a temporary value of a slope of the potential is higher than 10V/micro second, during a step(P2).

Description

Plasma display device having a drive means suitable for performing fast charge equalization operation {PLASMA DISPLAY DEVICE PROVIDED WITH DRIVE MEANS SUITABLE FOR CARRYING OUT RAPID CHARGE EQUALIZATION OPERATIONS}

The present invention provides an AC-type plasma panel having a memory effect with at least a cross-electrode that acts for addressing, and such a system suitable for performing charge-equalization (or reset), address and sustain operations in the discharge region of the panel. A display device comprising drive means for a panel, wherein the device is optionally provided with a coplanar electrode which acts at least for sustaining:

In general, an AC plasma display panel (PDP) having a memory effect includes two parallel plates in which a space containing a discharge gas exists between them; Between the plates, usually on the inner surface of these plates, such a panel has several electrode arrays, namely:

Generally two arrays of cross electrodes, each located on a different plate, thus a non-coplanar plane, acting to address the discharge, and at the intersection of the electrodes, in the space between the plates, a light discharge region is defined Two crossed electrode arrays;

At least two parallel co-planar electrode arrays located on the same substrate and acting to sustain a discharge, these arrays being in particular covered with a dielectric layer to provide a memory effect; This dielectric layer itself generally comprises an array of electrodes of at least two parallel coplanar surfaces, which are covered with a protective and secondary electron emission layer based on magnesium oxide.

Each electrode of the sustained array, together with the electrodes of the other sustained array, forms a pair of electrodes that generally define a continuous light discharge region distributed therebetween along a row of discharge regions of the panel.

The light discharge regions form a two-dimensional matrix on the panel; Each region can emit light, such that the matrix displays the image to be displayed.

In general, one of the coplanar electrode arrays serves for both addressing and persistence. In this particular case, the electrode array will hereinafter be referred to as Y, the co-planar second electrode array as X, and the address electrode array orthogonal to Y and X and located on another plate will be referred to as A. . Therefore, electrode arrays X and Y supply power to the rows of discharge regions, while electrode array A, which acts only for addressing, powers the columns of discharge regions.

Adjacent discharge regions that emit at least different colors are generally delimited by a barrier rib; Typically these barriers serve as spacers between the plates.

The walls of the light discharge region are generally partially coated with phosphors sensitive to ultraviolet radiation from the light discharge; Adjacent discharge regions are provided with phosphors that emit different primary colors in such a way that a combination of three adjacent regions form a pixel or pixels.

In fact, these phosphors cover the inclined walls of the barrier barriers and the plates supporting these barriers, which plates generally carry an electrode array which acts only for addressing; Therefore, the address electrode is covered with the phosphor.

When the plasma panel is operated, in order to display an image, a continuous display or subdisplay operation is performed using a matrix of discharge regions; In general, each subdisplay operation is

Firstly, as an optional addressing step, the purpose of this step is to modify the electrical charge on the dielectric layer in each discharge area to be activated by applying at least one voltage pulse between the cross-address electrodes in the discharge area. An optional address step;

Second, a non-selective sustaining step comprising a non-selective sustaining step, in which a continuous voltage pulse is applied between the electrodes of the sustaining pair to cause continuous light discharge only in the discharge region previously activated during this do.

After the subdisplay operation, the discharge regions can be in very different internal electrical voltage states, especially depending on whether these regions are activated during such subdisplay operations; Other factors include internal voltages such as undesired fluctuations in the dimensional characteristics of these discharge regions, associated with the characteristics of the phosphors corresponding to these regions, the panel manufacturing process, and variations in surface bonding of the walls of these regions. Contribute to this dispersion in state.

In order to make the internal voltage state the same for all discharge regions to be addressed, equalizing these regions precedes most of the address stages, in particular the purpose of which depends on whether they are activated during the previous subdisplay operation. To reset all discharge regions to be addressed to the same internal voltage state; This reset step includes an electrical charge forming or priming operation, which is conventionally followed by a charge adjustment operation also called a charge erase operation, after which, ideally, the internal voltage in each discharge region is between the address electrode and the sustain electrode. Approach ignition threshold.

For each pair of addresses or sustain electrodes in the discharge region, an external voltage applied between these electrodes and an internal voltage in the gas space separating the material covering these electrodes can be associated. In general, the internal voltage differs from the external voltage because of the surface charge present on the surface of the insulating material covering the electrode, at the interface between these dielectric materials and the gas in the discharge region.

These surface charges, on the one hand, arise from capacitive effects due to the dielectric properties of the material defining the discharge regions, and on the other hand, charges of charge called "memory" charges generated by previous discharges in the gases of these discharge regions. Resulting from accumulation.

The internal ignition threshold of the discharge region in a certain direction corresponds to the internal voltage limit value along this direction, and when this limit value is exceeded, gas is ionized in this region. This value depends on the properties of the gas in this area, the properties of the material in contact with the gas in this area, and the geometrical part of the electrode passing through this area outside of this area.

In the above specific case of the three electrode arrays X, Y, A, generally six internal thresholds are associated with each discharge region:

An internal threshold V _{IT_XY} for ignition between anode X and cathode Y;

An internal threshold V _{IT_YX} for ignition between the anode X and the anode Y;

An internal threshold V _{IT_XA} for ignition between anode X and cathode A;

An internal threshold V _{IT_AX} for ignition between the anode X and the anode A;

An internal threshold V _{IT_YA} for ignition between anode Y and cathode A;

An internal threshold (V _{IT_AY} ) for ignition between cathode (Y) and anode (A).

The terms "anode" and "cathode" relate to the internal potential in the gas of the discharge region near the electrode passing through this region. An electrode can be said to be an anode associated with another electrode when the potential in the gas near the electrode is greater than the potential near the other electrode, wherein this other electrode is called the cathode.

The next two internal thresholds have the same value, because these thresholds are co-planar discharges generated by electrodes that are received by the same plate and are generally positioned symmetrically with respect to the other one. Because it features:

_Expressed as V _IT-XY = V _{IT_YX} , V _{IT_S} .

However, since the next two internal thresholds are characterized by a matrix discharge, they are between two different plates, depending on whether the corresponding electrode acts as an anode or a cathode.

Displayed as V _IT-XA = V _{IT_YA} , V _{IT_A_ca}

Displayed as V _IT-AX = V _{IT_AY} , V _{IT_A_an} .

The reason is that when the column address electrode A acts as a cathode, the secondary emission from the phosphor containing the electrode is less than the secondary emission from magnesium oxide on the dielectric surface covering the row electrode X or Y. This is because discharge is generated at a higher voltage than when the electrode A serves as an anode.

Generally,

During a charge-forming or priming operation, each electrode Y acting for both addressing and sustaining is an anode with respect to the other two electrodes X and A;

During a charge-adjustment or erase operation, each electrode Y acting for both addressing and sustaining is a cathode for the other two electrodes X and A.

In general, these operations apply a slowly increasing potential difference between two matrix electrodes for addressing all discharge regions of the group to be addressed on the one hand between two coplanar sustain electrodes on one side. By doing so; Accordingly, the documents FR 2 417 848 (THOMSON-1978) and US 5 745 086 (PLASMACO-1998) describe an electrode or electrode that acts for both addressing and sustaining while applying a constant voltage signal to only another address electrode or only to a sustaining electrode. The application of the lamp voltage signal to the fields will be described.

Patent US 5 745 086 discloses that the reset operation for the panel area is achieved through a so-called series of "weak" discharges between the electrodes when no strong discharge is made but the slope of the applied lamp signal does not exceed 10 V / ㎲. It is shown that it is advantageously performed in the region. These "weak" discharges compensate for the increase in the external voltage applied to the electrodes by surface discharges deposited on the walls of the areas powered by these electrodes, and therefore, since no "strong" discharges occur, The internal voltage in the gas of the region remains equal to or slightly below the internal ignition threshold defined above.

A known advantage for resetting by a weak discharge, also referred to as "positive resistance" resetting, is that it generates a weak light emission, allowing precise adjustment of the internal electrical voltage within the discharge region. Fine tuning is essential for the performance and efficiency of subsequent address operations. Limiting such light emission is essential for the contrast performance of the display device.

The maximum inclination of the ramp signal which produces a weak discharge in the discharge zone, in particular, depends on the properties of the materials covering the cathode of this zone, in particular the secondary emission coefficient of these materials, and the amount of space charge and metastable elements of the gas in this zone. Depends. The commonly used gradient values do not exceed 5 V / ㎲ for the priming operation in which the Y electrode acts as an anode for the X and A electrodes. Therefore, the duration of the priming operation reaches several tens of milliseconds since the total amplitude of the ramp typically includes 200V. This duration represents the time spent with respect to other operations to be performed during the scan or subscan, namely address and sustain operation, thereby limiting display device performance, particularly with regard to maximum emissions. Moreover, certain panels can be defective at the end of the production line, since the standard lamp values represent an operating defect associated with the presence of a strong discharge during the priming lamp, which further increases the production cost of the panel. .

It is an object of the present invention to limit this drawback; It is also an object of the present invention to shorten the duration of this discharge region reset operation without reducing the efficiency, ie still maintaining the level of equalization of the various discharge regions.

To this end, an object of the present invention is a display device, which display device;

An AC plasma panel having a memory effect, comprising two plates with a space therebetween containing a discharge gas and at least two cross-electrode arrays acting for addressing, at the intersection of said electrode arrays, An AC plasma panel in which a light discharge region is defined in the space between the plates;

Drive means suitable for applying a voltage signal suitable for performing an operation intended to equalize charges or reset the discharge region in the discharge region;

A display device comprising:

The driving means, during the specific operation of resetting the group of discharge regions,

Where each discharge region of the panel has an external matrix ignition threshold voltage V _{ET_E2EI} between at least the electrodes acting for addressing and crossing the region, and Min [V _{ET_E2E1} ] and Max [V _{ET_E2E1} ] are the groups, respectively. For the minimum and maximum values of the matrix ignition voltage V _{ET_E2E1 in} the region of

The applied potential difference between the areas of this group between the electrodes serving at least for addressing and intersecting (V _E2E1) is, as soon as V _E2E1 during the reset operation is greater than the value _{(1.1 × Max [V ET_E2E1]} ), V E2E1 It is characterized in that it is designed to increase to a so-called final operating gradient steeper than the maximum increasing gradient of V _E2E while it is between Min [V _{ET_E2E1} ] and Max [V _{ET_E2E1} ].

Therefore, the present invention relates to the first case or the first embodiment, which will be described later in more detail.

The object of the invention is also a display device according to the same principle,

An AC plasma panel having a memory effect, comprising two plates with a space therebetween containing a discharge gas and at least two cross-electrode arrays acting for addressing, at the intersection of said electrode arrays, An AC plasma panel in which the light discharge regions are defined in the space between the plates, the at least two electrode arrays serving for at least sustain, and one of the electrodes of each of these arrays placed so as to pass through each discharge region;

Drive means suitable for applying a voltage signal suitable for performing an operation intended to equalize charges or reset the discharge region in the discharge region;

A display device comprising:

The driving means, during the specific operation of resetting the group of discharge regions,

Where each discharge region of the panel has an external matrix ignition threshold voltage (V _{ET_EA2EAI} ) between the electrodes serving to at least address and intersect the region, and Min [V _{ET_EA2EA1} ] and Max [V _{ET_EA2EA1} ] are the groups, respectively. The ignition threshold voltage (V _{ET_ES2ES1} ) of the outer coplanar plane between the minimum and maximum values of the matrix ignition voltage (V _{ET_EA2EA1} ) in the region of and between the electrodes acting for each discharge region of the panel to pass through and sustain at least the region. And Min [V _{ET_ES2ES1} ] and Max [V _{ET_ES2ES1} ] are the minimum and maximum values of the ignition voltage V _{ET_ES2ES1} of the co-planar of the group region, respectively.

The potential difference V _EA2EA1 applied between the electrodes acting to address and intersect at least this region of this group does not exceed the value Min [V _{ET_EA2EA1} ], while at least passing and sustaining the region of this group The potential difference V _ES2ES1 applied between the electrodes acting for the purpose does not exceed the value Max [V _{ET_ES2ES1} ], and at least the potential difference V _ES2ES1 applied between these electrodes acting for the duration is the value ( As soon as Max [V _{ET_ES2ES1} ]) is exceeded, the so-called positive final operating gradient is increased;

- or at least the addressing and the potential difference applied between the electrodes serving to cross the area of the group (V _EA2EA1) is the applied potential difference, at least between the electrodes serving to continue passing the region (V _ES2ES1) As soon as V exceeds the value Max [V _{ET_ES2ES1} ], while V _ES2ES1 is between Min [V _{ET_ES2ES1} ] and Max [V _{ET_ES2ES1} ], it is designed to increase with a so-called positive final operating gradient steeper than the maximum increase slope of V _EA2EA1 . It is characterized by.

Therefore, the present invention relates to a second case or a second embodiment, which will be described later in more detail, or a third case or third embodiment, which will be described in more detail later.

In general, the drive means,

As a select address operation for selectively activating or deactivating the discharge region; This operation is performed by applying a voltage pulse between at least the electrodes acting for addressing;

A non-selective sustaining operation which initiates discharge only in the pre-activated discharge area of the panel; The operation may be performed by applying a voltage pulse between at least the electrodes acting for sustaining.

It is suitable to perform more.

Such panels are said to have a "memory effect" because, for a duration, discharges are only generated in those areas that were previously activated; To this end, in each discharge region, at least one of the electrodes serving at least for sustaining is coated with a dielectric layer which is itself covered with a protective and secondary electron emitting layer.

The dielectric layer provides a memory effect that, during sustained operation, allows the memory to initiate discharge only in the active area; In general, the protective layer is based on magnesium oxide and has a high secondary electron emission higher than the secondary electron emission coefficient of the material (typically phosphor) coating at least one of the electrodes serving at least for addressing in each discharge region. Has a coefficient.

Preferably, the drive means is designed such that, during the particular electron-equalization or reset operation, in each region of the group, an electrode covered with a protective layer serves as an anode; The specific reset operation at this time is a charge-forming or priming operation; In this case, therefore, no charge adjustment or erase operation takes place, in which such an electrode, which is covered by a protective layer, generally serves as the cathode.

In general, each reset operation is associated with a row group, or even all rows, of the discharge area of the panel; These operations are generally initiated before the select address operation.

The term "matrix ignition" is understood to mean the onset of discharge between at least the electrodes acting for addressing, and the term "co-planar ignition" refers to the onset of discharge between the electrodes acting at least for sustaining. It is understood to mean.

If the panel comprises a coplanar electrode array carried by the same plate, these electrodes serve at least for sustaining; Then, the other plate generally contains an array of electrodes which act primarily for addressing or even further to initiate sustained discharge; In this case, at least one of the electrode arrays acting for addressing is preferably merged with one of the electrode arrays acting for at least persistence, forming one of the coplanar electrode arrays; Therefore, this electrode array acts as an anode during the priming operation. At this time, the coplanar plasma panel of the prior art is used.

If the panel does not have a co-planar electrode array, the sustaining operation is generally performed by applying a voltage pulse between the electrodes that also act for addressing; Next, the panel generally has two electrode arrays, one on each plate; As a variant, the sustaining operation can be performed by applying a radio frequency electric field to the discharge region, in which case the array electrodes serve only for addressing.

Due to the present invention, it is possible to shorten the period required for the reset operation and to devote additional time only to the sustain operation, thereby improving the light emitting performance of the panel.

Due to the present invention, the amount of waste can be reduced to substantially improve the production yield of the plasma panel.

Preferably, the final operating gradient which increases the potential difference between the electrodes acting at least for addressing is greater than 5 V / ㎲.

Thus, as soon as all the matrix ignition thresholds are exceeded in the first case, and as soon as the ignition thresholds of all the co-planar surfaces are exceeded in the second or third case, the reset operation does not cause any loss in the quality of these operations. Achieve much faster than the prior art without any risk of strong discharges that could damage the contrast; Therefore, more time can be devoted to other driving operations, in particular to sustaining operations, thereby making it possible to improve display performance, especially in the case of video image displays.

Preferably, the final operating gradient, which increases the potential difference between the electrodes acting at least for addressing, is greater than 10 V / ㎲. The performance of the device and the advantages of the present invention are further improved.

Preferably, when the second or the third case, V _ES2ES1 during which the reset operation Min [V _{ET_ES2ES1]} and Max [V _{ET_ES2ES1]} While in between, the potential difference applied between the electrodes serving at least for sustaining (V _ES2ES1 ) increases with a so-called starting operating gradient that is greater than 5 V / s, preferably greater than 10 V / s. The performance of the device and the advantages of the present invention are further improved.

Preferably, during each particular reset operation, at least the potential difference V _E2E1 ; V _EA2EA1 applied between the electrodes acting for addressing is when Min [V _{ET_E2E1} ] <V _E2E1 <Max [V _{ET_E2E1} ], or Constantly and precisely increased when Min [V _{ET_EA2EA1} ] <V _EA2EA1 <Max [V _{ET_EA2EA1} ]. The term "constantly and precisely increasing" is understood to mean a non-zero increase. Preferably, this increase is linear with time; Therefore, this is achieved through a linear voltage ramp applied to one of the electrode arrays, which is easier to implement.

Preferably, in the second or third case, during each particular reset operation, the potential difference (V _ES2ES1 ) applied between the electrodes acting for at least the sustain is Min [V _{ET_ES2ES1} ] <V _ES2ES1 <Max [V _{ET_ES2ES1} Increase at a constant and precise rate.

The term "constantly and precisely increasing" is understood to mean a non-zero increase. Preferably, this increase is linear with time; Therefore, this is implemented with a linear voltage ramp applied to one of the electrode arrays; This is easier to implement.

A summary of the principles underlying the invention as applied to the priming operation is given below:

Setting the conditions of the discharge area to obtain a weak discharge scheme with the highest possible gradient between two electrodes acting for addressing (E1 and E2 acting as cathodes, or EA1 and EA2, E1 or EA1). The initial level for conditioning rises before a steep slope signal is applied between these electrodes.

The invention therefore relates to two successive steps within the same reset operation:

Generating a metastable space charge obtained by the discharge (P1);

An accelerated charge generation termination step P2 corresponding to making all such charges equal, during which the system is generally at least between the electrodes E1 and E2 acting for addressing, or between EA1 and EA2 It operates in such a way that a weak discharge occurs with the highest possible slope greater than 10V / kV.

The invention can be applied, for example, to plasma panels having several cell or discharge-region structures of the type "ACM", "ACC" or "ACC3E".

In the first case applicable to an ACC panel with any type of "ACM" type matrix panel having two electrodes E1, E2 per cell, or three or more electrodes per cell (including EA1 and EA2) Step P1 consists of applying a ramp that is gently sloped for a time long enough to create a discharge between two electrodes E1 and E2 (or alternatively EA1 and EA2) regardless of the previous state of the cell. In fact, this gentle slope value corresponds to the slope generally used in the prior art, i.e., less than 10 V / ㎲. The resulting E1-E2 (or alternatively EA1-EA2) discharge causes both the conditioning of the cell and some of the equalization of the internal voltage of the cell between the electrodes E1 and E2 (or alternatively EA1 and EA2). To act.

In the second and third cases applicable to co-planar panels of the " ACC " type comprising at least three electrodes per cell (EA1, EA2 = ES2, ES1), step P1 is the electrode of the coplanar surface of the cell; Between ramps with steeper slopes than in the prior art, typically greater than 10 V / ㎲, the ES1 acting as a cathode is EA1 and EA2 (standard "ACC" case: EA1: column, EA2 = ES2 = "scan / sustained" row, ES1 = "common" row), which is covered with a material having a secondary emission factor greater than the secondary emission factor covering ES2. The resulting ES1-ES2 coplanar discharge serves both for conditioning the cell and for partial equalization of the internal voltage between ES1 and ES2. The second and third cases are distinguished as follows:

Second case: No discharge is produced between EA1 and EA2 during step P1 and the ignition voltage is not internally exceeded between these electrodes. This may be accomplished with various signals (constant signal, ramp signal or other signals) between EA1 and EA2 if the ignition threshold is not exceeded. During this step P1, the weak coplanar discharge is initiated, the weak matrix discharge is prevented, and the amplitude of the ramp signal applied in a matrix manner does not exceed the matrix threshold voltage at any instant.

Case 3: A matrix discharge is produced between EA1 and EA2 during step P1 simultaneously with the discharge of the coplanar between ES1 and ES2. In this case, the slope of the signal between EA1 and EA2 must be small to allow operation in a weak discharge manner until reaching a level sufficient for the condition setting of the cell. In this case, the slope of the signal between EA1 and EA2 is smaller than the slope between ES1 and ES2.

Step P2 is characterized by the application of a ramp signal with a higher slope than in the prior art, which is generally greater than 10 V / V between EA1 and EA2. At this stage, what happens between the different electrodes is not very important.

Steps P1 and P2 may be selectively separated by a period in which no discharge occurs in the cell (for example, when the voltage applied temporarily does not increase). This period must not exceed 20 ms so that the conditioning effect generated during P1 is still active at P2.

The embodiment described is derived from this general principle and from the conditions under which the discharge is created between the electrodes specific to each cell of the panel;

Is bound to an ignition threshold that varies from cell to cell,

This is because the cell's history (previously illuminated or unilluminated) is constrained to the surface memory charge state.

The invention will be more clearly understood by reading the following detailed description, given by way of non-limiting example with reference to the accompanying drawings.

1 is a timing diagram illustrating the application of a potential difference between electrodes of a matrix panel during a charge generation operation in accordance with a first embodiment of the present invention.

2 is a timing diagram illustrating the application of a potential difference between address electrodes and sustain electrodes of a coplanar panel during a charge generation operation in accordance with a second embodiment of the present invention.

3 is a timing diagram illustrating the application of a potential difference between address electrodes and sustain electrodes of a coplanar panel during a charge generation operation in accordance with a third embodiment of the present invention.

4 illustrates applying a voltage to a three electrode array of a conventional coplanar panel during a charge generation operation to illustrate the advantages of the present invention compared to prior art timing diagrams, according to the detailed examples given herein. One general timing diagram.

Figures 5 to 7 show the strong discharges which are technically obtained when a voltage is applied to three electrode arrays according to a fast timing diagram without departing from the scope defined by the present invention.

FIG. 8 illustrates the advantages provided by the present invention, i.e. no strong discharge when a voltage is applied to the three electrode arrays according to a fast timing diagram.

<Explanation of symbols for the main parts of the drawings>

P1: charge generation step P2: charge generation end step

V _E2E1 : potential E1, E2: electrode

V _EA2EA1 : Potential difference

Various general embodiments of the invention will now be described; The first embodiment is applied to a matrix plasma panel having only two electrode arrays E1 and E2, one on each plate, which serves for both addressing and sustaining discharge; Another embodiment comprises two continuous electrode arrays ES1 and ES2 on the same plate called the coplanar plate and the address electrode EA1 on the plate called the address plate and the coplanar plane facing the plate of the coplanar plane. It is applied to a coplanar type plasma panel having two arrays of address electrodes EA2 on the plate. This other embodiment applies to a conventional coplanar panel where the coplanar electrode array acts for both addressing and persistence, which means that EA2 then merges with ES2.

The sustain electrodes E2 or ES1 and ES2 are coated with a dielectric layer covered with a material, such as magnesium oxide, having a high secondary electron emission coefficient and in some cases higher than the material covering the electrode E1 or EA1 of the address plate. Become; The material covering the electrode E1 or EA1 is generally a phosphor; In a magnified analysis, the plates supporting these electrodes and the magnesium oxide layer are referred to as continuous plates or hollow flat plates in the case of hollow flat panels.

The matrix panel includes a plurality of discharge regions; After an image scan or _subscan , each area of the panel has an external ignition threshold voltage V _{ET_E2E1} in the case of a charge generation operation in which E2 on the sustain plate acts as an anode. The minimum value of the ignition voltage of all areas of the panel is represented by Min [V _{ET_E2E1} ], and the maximum value of the ignition voltage of all areas of the panel is represented by Max [V _{ET_E2E1} ].

The cavity flat panel comprises a plurality of discharge regions; After the scanned image or the sub-scan, each region of the panel has an external matrix ignition threshold voltage (V _{ET_EA2EA1)} and an external coplanar having a lighting threshold voltage (V _{ET_ES2ES1),} which, the role of the EA2 and ES2 on the coplanar plate anode This is also done in the case of charge generation operation. The minimum values of the matrix ignition voltage and the coplanar ignition voltage of all areas of the panel are represented by Min [V _{ET_EA2EA1} ] and Min [V _{ET_ES2ES1} ], respectively, and the maximum values of the matrix ignition voltage and the coplanar ignition voltage of all areas of the panel are respectively. Max [V _{ET_EA2EA1} ] and Max [V _{ET_ES2ES1} ].

All embodiments of the invention presented below relate to charge generation or priming operations; According to an essential feature of the invention, each of these operations comprises a step P1, called a charge generation and conditioning start step, having a duration tau 1, after which the acceleration, having a duration tau 2, follows. Step P2, which is called the end of charge generation step, is followed by a time for separating the end of the first step and the start of the second step from which it is desired to fully benefit from the condition setting of the discharge region in the second step P2. In this case, it is not necessary to exceed 20㎲.

Therefore, in FIG. 1 describing the charge generation or priming operation of the matrix panel, the following external voltages between the electrodes E2 (anode) and E1 (cathode) can be distinguished successively:

V _{E2E1_P1_ST} at the beginning of step P1;

V _{E2E1_P1_ND} at the end of step P1;

V _{E2E1_P2_ST} at the beginning of step P2;

V _{E2E1_P2_ND} at the end of step P2;

Therefore, in FIGS. 2 and 3 describing the charge generation or priming operation of the co-planar panel, the sustain electrode {ES2 (anode) and on the other hand the address electrode {EA2 (anode) and EA1 (cathode)} on the one hand. The following external voltages between ES1 (cathode)} can be distinguished successively:

V _{EA2EA1_P1_ST} and V _{ES2ES1_P1_ST} at the beginning of step P1;

V _{EA2EA1_P1_ND} and V _{ES2ES1_P1_ND} at the end of step P1;

V _{EA2EA1_P2_ST} and V _{ES2ES1_P2_ST} at the beginning of step P2;

V _{EA2EA1_P2_ND} and V _{ES2ES1_P2_ND} at the end of step P2.

For the sake of simplicity, the same reference numerals are used for elements that meet the same functionality in various embodiments.

First embodiment: for matrix or co-planar panels

Referring to FIG. 1, two steps P1 and P2 are defined as follows:

V _{E2E1_P1_ST} <Min [V _{ET_E2E1} ]; Thus, at the beginning of step P1, the discharge ignition threshold does not exceed in any cell of the panel regardless of the charge state resulting from operation during the previous scan or subscan; Preferably, V _{E2E1_P1_ST ≧} 0.9 × Min [V _{ET_E2E1} ], so that the weak discharge starts to start in the area of the panel directly from the start of the condition setting step P1;

V _{E2E1_P1_ND} > Max [V _{ET_E2E1} ]; Thus, the discharge ignition threshold is exceeded in each cell of the panel after the condition setting step P1 regardless of the charge state resulting from the previous operation to generate the initial condition setting state; Preferably, V _{E2E1_P1_ND} ≦ 1.1 × Max [V _{ET_E2E1} ] to use the period P2 of the rapid potential increase rate as soon as possible without unnecessarily extending the period P1 of the slow potential increase rate;

V _{E2E1_P2_ST} = V _{E2E1_P1_ND} , so that the two steps P1 and P2 are connected together without a transition;

V _{E2E1_P2_ND} is _defined in the same manner as in the prior art, ie to achieve the desired priming level in all the discharge regions of the panel at the end of step P2.

During step P1, the rate of increase of the potential V _E2E1 between the electrodes, or the instantaneous value of the slope dV _E2E1 / dτ, is in accordance with the prior art, i.e., 5 V / ㎲ over the duration τ1 of this step. Less than; In contrast, according to the invention, during step P2, the rate of increase of the potential V _E2E1 between the electrodes, or the instantaneous value of the slope dV _E2E1 / dτ, is the duration τ2 of this step in the prior art. It is substantially larger than the whole, preferably greater than 10 V / kHz.

Therefore, in general, according to the invention, the potential between the electrodes increases much faster at the end of the charge generation period during step P2 than at the beginning of this period during step P1; Therefore, the time for priming operations is greatly reduced without damaging the quality of these operations.

Second Embodiment: For a Common Flat Panel

Referring to FIG. 2, two steps P1 and P2 are defined as follows:

V _{ES2ES1_P1_ST} <Min [V _{ET_ES2ES1} ]; Thus, at the start of P1, the coplanar discharge ignition threshold is not exceeded in any cell of the panel, regardless of the charge state resulting from the previous operation; Preferably, V _{ES2ES1_P1_ST ≧} 0.9 × Min [V _{ET_ES2ES1} ] so that the weak co-planar discharge begins to start in the area of the panel directly from the beginning of step P1;

V _{ES2ES1_P1_ND} > Max [V _{ET_ES2ES1} ]; Thus, at the end of step P1, the coplanar discharge ignition threshold is exceeded in each cell of the panel regardless of the charge state resulting from the previous operation, creating an initial condition setting state; Preferably, V _{ES2ES1_P1_ND} ≦ 1.1 × Max [V _{ET_ES2ES1} ] so that step P2 is used as soon as possible without unnecessarily extending step P1;

V _{EA2EA1_P1} <Min [V _{ET_EA2EA1} ], which means that at each instant τ of the condition setting step P1, the potential difference between the address electrodes V _{EA2EA1_P1} is kept below Min [V _{ET_EA2EA1} ], so that during this step no matrix No discharge is generated in the panel; _Recognizing that V _{ET_EA2EA1} may change during P1 depending on the charge generated near the electrode, it will be noted that this inequality is satisfied for any moment of P1;

V _{EA2EA1_P2_ST} <Min [V _{ET_EA2EA1} ]; Thus, at the beginning of step P2, the matrix discharge ignition threshold does not exceed in any cell of the panel regardless of the charge state resulting from the previous operation; Preferably, V _{EA2EA1_P2_ST ≧} 0.9 × Min [V _{ET_EA2EA1} ] such that the weak matrix discharge starts to be started in the area of the panel directly from the beginning of step P2;

V _{EA2EA1_P2_ND} is _defined in the same manner as in the prior art, ie to obtain the desired priming level in all discharge regions of the panel.

During step P1, the rate of increase of the potential V _ES2ES1 between the sustain electrodes, or the instantaneous value of the slope dV _ES2ES1 / dτ, is substantially higher than in the prior art, preferably larger than 10V / ㎲; The rate of increase in step (P1) while, the potential (V _EA2EA1) is, the potential may be a zero, low or high, if the remaining less than Min [V _{ET_EA2EA1].}

During step P2, the rate of increase of the potential V _EA2EA1 between the address electrodes, or the instantaneous value of the slope dV _EA2EA1 / dτ, is substantially higher than in the prior art, preferably larger than 10V / ㎲; During this step P2, the rate of increase of the potential V _ES2ES1 may be zero, low or high.

In general, according to the present invention, the charge generation operation is performed by exceeding all co-planar discharge thresholds before starting to exceed the first matrix discharge threshold, in such a way that the gas is conditioned before the matrix discharge begins; This results in a coplanar discharge on the material coating the electrode of the coplanar plate with a high secondary electron emission coefficient, thereby creating a weak coplanar discharge (ES1-ES2) with a steep slope during step P1. Is advantageous because it makes it possible; The condition setting thus achieved during this step P1 is in the prior art in spite of the generally normal secondary emission properties of the material, which is generally a phosphor used herein as a cathode and coating the electrode of the address plate. Makes it possible to produce a weak matrix discharge EA1-EA2 with a more gentle gradient during step P2; Thus, due to the present invention, the time for priming operations can be greatly reduced, and accurate operation can be achieved through panels with poor phosphor secondary emission properties without any loss of quality of these operations. have.

Third embodiment: for a common flat panel

This embodiment differs from the previous embodiment where the finite matrix discharge is "allowed" during the coplanar conditioning period.

Referring to FIG. 3, two steps P1 and P2 are defined as follows:

V _{ES2ES1_P1_ST} <Min [V _{ET_ES2ES1} ] and V _{EA2EA1_P1_ST} <Min [V _{ET_EA2EA1} ]; Thus, at the beginning of step P1, the coplanar or matrix discharge ignition threshold does not exceed in any cell of the panel regardless of the charge state resulting from the previous operation; Preferably, V _{ES2ES1_P1_ST ≧} 0.9 × Min [V _{ET_ES2ES1} ] and / or V _{EA2EA1_P1_ST ≧} 0.9 × Min [V _{ET_EA2EA1} ] such that the co-planar or matrix discharge begins to commence immediately from the beginning of step P1;

V _{ES2ES1_P1_ND} > Max [V _{ET_ES2ES1} ] and V _{EA2EA1_P1_ND} > Min [V _{ET_EA2EA1} ]; Thus, at the end of step P1, the coplanar discharge ignition threshold is exceeded in each cell of the panel irrespective of the charge state resulting from the previous operation, and the matrix discharge ignition threshold is also among these cells to generate an initial conditioning state. Exceeding all or part of it;

V _{EA2EA1_P2_ND} is _defined in the same manner as in the prior art, ie to obtain the desired priming level in all discharge regions of the panel.

During the step P1, the rate of increase of the potential V _ES2ES1 between the sustain electrodes, or the instantaneous value of the slope dV _ES2ES1 / dτ, is substantially larger than in the prior art, preferably larger than 10V / ㎲; During this step P1, the rate of increase of the potential V _EA2EA1 is less than 5V / ㎲, according to the prior art.

During step P2, the rate of increase of the potential V _EA2EA1 between the address electrodes, or the instantaneous value of the slope dV _EA2EA1 / dτ, is substantially higher than in the prior art, preferably larger than 10V / ㎲; During this step P2, the rate of increase of the potential V _ES2ES1 may be zero, low or high.

Due to the present invention, the time for priming operations can thus be greatly reduced, and accurate operation can be achieved through panels having poor phosphor secondary emission properties without any loss of quality of these operations. have.

Fourth embodiment: for coplanar or matrix panels

This embodiment allows the condition setting generated during P1 to be performed in all or part of the cell by strong discharge and in other cells by weak discharge. This embodiment is not a preferred embodiment unless the strong discharge is a sustained discharge.

Fifth Embodiment: For Coplanar or Matrix Panels

The fifth embodiment adds to the previous four embodiments the possibility of including a period in which no discharge occurs in all or part of the cell between steps P1 and P2, which period does not exceed 20 ms. Therefore, the condition setting of P1 is still activated at the start of the discharge during P2. Substantial use of periods when no discharge occurs is known in the art and will not be described in detail herein; The internal voltage should be kept below the ignition threshold.

The various embodiments described above as non-limiting examples of the present invention allow the rate of increase of the potential applied between the electrodes during the panel reset operation to be increased in comparison with the prior art; Therefore, the present invention,

Reduce the time allotted to the priming operation and use it for addressing or sustaining, thereby allowing the fidelity or peak brightness of the panel to be increased;

Alternatively, panel manufacturing efficiency can be increased by not causing panels with strong discharges during priming with standard gradients to be non-defective.

Finally, it will be apparent to those skilled in the art that the present invention is applicable to other possible cases where lamp signals are used to drive a plasma panel without departing from the appended claims.

Examples and Comparative Examples of the Invention

Various types using the same coplanar type plasma panel with two electrode planar electrodes X and Y on the front plate and three electrode arrays comprising electrodes A on the back plate for addressing Will be applied and the impact on the discharge of these signals will be evaluated while applying these signals.

Such co-planar panels are known in the art and are described at the beginning of this specification with the same reference numbers (X, Y and A) for the electrodes.

4 shows a timing diagram for the voltage signal applied to the various electrodes X, Y and A of the panel during the priming operation: where the linear voltage ramp is characterized by a ramp peak level V _{pY of} 400V. And address electrode Y (corresponding to electrode EA2 corresponding to ES2 here in the general embodiment described above); Over time, a constant signal (V _pX ) is applied to an X electrode (often referred to as a "common" electrode) that acts only for sustaining, and a constant signal (V _A = 0) is the address electrode located on another plate. Is applied to (A). These signals are used to show the panel's response to very steep lamps with or without the present invention.

During each priming operation, the intensity of strong discharge D _S , which can occur unexpectedly and damages normal use, is recorded using photosensitive sensors located in front of the group of discharge areas of the screen.

The resulting recordings correspond to FIGS. 5 to 7; All such recordings occur under the same priming operating conditions, in particular under application of a linear ramp signal, except for a constant bias signal value V _pX of the coplanar electrode X:

5: V _pX = + 100V: Then, the internal ignition threshold between the electrodes X and Y serving at least for duration reaches later than the internal ignition threshold between the address electrodes Y and A; Therefore, priority is given to matrix discharges; Many strong discharges D _s are observed due to very high gradient values without prior cell setting of the cell;

8: V _pX = -120V: Then, the internal ignition threshold between the address electrodes Y and A reaches later than the internal ignition threshold between the electrodes Y and X serving at least for duration; Therefore, priority is given to the initiation of the coplanar discharge; 8 shows no strong discharge D _S due to the previous condition setting of the cell by the weak co-planar discharge; Such a configuration illustrates the invention.

6 and 7 correspond to intermediate states, where V _pX is equal to 0 V and −80 V, respectively, and an unacceptable residue of strong discharge D _S is observed.

Therefore, during each priming operation, the potential difference between the electrodes Y and X serving at least for sustaining and the potential difference between the address electrodes Y and A increase with the same linear gradient, and the above-described general second of the present invention A situation similar to one of the cases shown in FIG. 2 corresponding to the embodiment occurs; Therefore, in accordance with the invention shown in FIG. 8, the priming operation begins in a first step P1, wherein the coplanar discharge is sufficiently negatively biased to the coplanar electrode X associated with the address electrode A. FIG. Sufficient priority is given; Above a certain voltage level between address electrodes Y and A, the matrix discharge exceeds the matrix ignition threshold without this time generating a strong discharge because the discharge region was previously "conditioned" by the coplanar discharge. It is inevitable because of that. Therefore, each bias voltage at X and A determines step P1, which is characterized in that only co-planar discharges produce an initial conditioning state of each cell. The intermediate state shown in FIGS. 6 and 7 relates to the simultaneous co-planar and matrix discharge activation in a particular cell. Since the inclination applied between Y and A is as high as the inclination applied between Y and X, insufficient discharge setting causes strong discharge. In order to prevent the strong discharge D _S , the solution according to the invention applies a gentle initial slope between the electrodes Y and A as in the third general embodiment of the invention described above.

As described above, the present invention provides an AC-type plasma panel having at least a cross-electrode acting for addressing and having a memory effect, and performing charge-equalization (or reset), address and sustain operations in the discharge region of the panel. It is effective for a display device or the like including suitable driving means of such a panel.

Claims (11)

An AC plasma panel having a memory effect, comprising two plates with a space therebetween containing a discharge gas and at least two cross-electrode arrays E2 and E1 acting for addressing, said electrode array An AC plasma panel, in which an optical discharge region is defined in the space between the plates at the intersection of; Drive means suitable for applying a voltage signal suitable for performing an operation intended to equalize charges or reset the discharge region in the discharge region; A display device comprising: The driving means, during the specific operation of resetting the group of discharge regions, Each discharge region of the panel has an external matrix ignition threshold voltage (V _{ET_E2E1} ) between the electrodes acting for addressing and crossing the region, and Min [V _{ET_E2E1} ] and Max [V _{ET_E2E1} ] are the group regions, respectively. For the minimum and maximum values of the matrix ignition voltage (V _{ET_E2E1} ) of The applied potential difference between the electrodes serving at least for addressing and intersecting the said regions of this group (V _E2E1) is, as soon as V _E2E1 during the reset operation is greater than the value _{(1.1 × Max [V ET_E2E1]} ), V E2E1 A display device, characterized in that it is designed to increase to a so-called end-of-operation slope steeper than the maximum increasing slope of V _E2E1 while it is between Min [V _{ET_E2E1} ] and Max [V _{ET_E2E1} ]. The display device according to claim 1, wherein the final operating gradient for increasing the potential difference between the electrodes acting at least for addressing is greater than 5 V / ㎲. 3. A display device according to claim 2, wherein the final operating gradient for increasing the potential difference between the electrodes acting at least for addressing is greater than 10V / kHz. 2. The method of claim 1, wherein during each particular reset operation, the potential difference V _E2E1 applied between at least the electrodes acting for addressing is constant when Min [V _{ET_E2E1} ] <V _E2E1 <Max [V _{ET_E2E1} ]. And precisely increasing. An AC plasma panel having a memory effect, comprising two plates with a space therebetween containing a discharge gas and at least two cross-electrode arrays EA2 and EA1 acting for addressing, said electrode array At the intersection of, the light discharge region is defined in the space between the plates, at least two electrode arrays ES2 and ES1 serve for at least sustain, and one of each of these electrode arrays ES2 and ES1 is each discharged. An AC plasma panel positioned to pass through the area; -Drive means suitable for applying a voltage signal suitable for performing an operation intended to equalize charges or reset the discharge region in the discharge region, to the electrodes EA2, EA1, ES2, ES1. A display device comprising: The driving means, during the specific operation of resetting the group of discharge regions, Each discharge region of the panel has an external matrix ignition threshold voltage (V _{ET_EA2EA1} ) between the electrodes (EA2, EA1) that serves for at least addressing and crossing of the region, and Min [V _{ET_EA2EA1} ] and Max [V _{ET_EA2EA1} ] are the minimum and maximum values of the matrix ignition voltage V _{ET_EA2EA1} of the regions of the group, respectively, and the electrodes ES2 and ES1 each discharge region of the panel acts to at least sustain and pass through the region. With an external coplanar ignition threshold voltage (V _{ET_ES2ES1} ) between and where Min [V _{ET_ES2ES1} ] and Max [V _{ET_ES2ES1} ] are the minimum and maximum values of the coplanar ignition voltage (V _{ET_ES2ES1} ) of the region of the group, respectively. , The potential difference V _EA2EA1 applied between the electrodes EA2, EA1 acting at least for addressing and crossing the region of this group does not exceed the value Min [V _{ET_EA2EA1} ], while this group The potential difference V _ES2ES1 applied between the electrodes ES2, ES1 acting to at least address and pass through the region of does not exceed the value Max [V _{ET_ES2ES1} ] and at least acts for sustaining. As soon as the potential difference V _ES2ES1 applied between these electrodes ES2 and ES1 exceeds the value Max [V _{ET_ES2ES1} ], the so-called positive final operating gradient is increased; Or the potential difference V _EA2EA1 applied between the electrodes EA2, EA1 acting at least for addressing and crossing said region of this group is such that the electrodes acting for at least sustaining and passing of said region. (ES2, ES1) as soon as exceeds the potential difference (V _ES2ES1) the value (max [V _{ET_ES2ES1])} applied between a maximum of V _RA2EA1 while between V _ES2ES1 the Min [V _{ET_ES2ES1]} and max [V _{ET_ES2ES1]} A display device, characterized in that it is designed to increase with a so-called positive final operating gradient steeper than an increase gradient. 6. A display device as claimed in claim 5, wherein the final inclination for increasing the potential difference between the electrodes acting at least for addressing is greater than 5V / ㎲. 7. A display device as claimed in claim 6, wherein the final inclination for increasing the potential difference between the electrodes acting at least for addressing is greater than 10V / kHz. 6. The method according to claim 5, wherein when V _ES2ES1 is between Min [V _{ET_ES2ES1} ] and Max [V _{ET_ES2ES1} ], the potential difference (V _ES2ES1 ) applied between the electrodes acting at least for sustaining is less than 5V / 5. A display device, characterized in that it increases with a larger starting operating gradient. 9. A display device as claimed in claim 8, wherein the starting operating gradient for increasing the potential difference between the electrodes acting at least for sustaining is greater than 10V / kHz. 6. The method of claim 5, wherein during each particular reset operation, the potential difference (V _EA2EA1 ) applied between at least the electrodes acting for addressing is constant when Min [V _{ET_EA2EA1} ] <V _EA2EA1 <Max [V _{ET_EA2EA1} ]. And precisely increasing. 6. The method of claim 5, wherein during each particular charge equalization or reset operation, the potential difference (V _RS2RS1 ) applied between the electrodes acting at least for sustaining is Min [V _{ET_ES2ES1} ] <V _ES2ES1 <Max [V _{ET_ES2ES1} ] A display device, characterized in that it increases constantly and precisely when.