Nec Corporation

Pioneer Corporation

Nec Plasma Display Corporation

Pioneer Plasma Display Corporation

Eishi Mizobata

Hiroshi Kanoh

Yoshihiko Hirai

Naoyasu Ikeda

Hidenori Ikeno

Tadashi Nakamura

Shinichi Nishida

Setsuo Kaneko

Yoshito Tanaka

Manabu Fujiwara

A plasma display improved in variation of display brightness between unit cells. A control circuit sets, for every pulse, a charge-recovering time period for recovering a charge on a capacitance component of the plasma display panel and a clamp timing period for applying a predetermined sustain voltage to the sustain electrodes or the scan electrodes after the charge-recovering time period through clamp start timing, and sets a sustain-discharge emission intensity ratio, as a ratio of a maximal discharge intensity in the clamp timing period with reference to a discharge intensity in the clamp start timing to a maximum discharge intensity in the charge-recovering time period, at a value that a discharge in the clamp timing period is to spread up to an end of the unit cell. For example, the control circuit sets a sustain-discharge emission intensity ratio substantially at 0.5 or greater or 0.1 or smaller, thus eliminating the occurrence of image retention.

Plasma display and drive method for use on a plasma display

Scan electrodes are provided separately in addition to sustain electrode pairs generating a sustain discharge. An Address-While-Display drive, in which a scan pulse and a sustain pulse are applied at the same timing, is conducted for each subfield. When scan pulses are applied to the scan electrodes, a wall voltage is generated by a wall charge formed on the dielectric layer located on the scan electrodes. This wall voltage is set higher in the negative voltage direction than the wall voltage generated by a wall charge formed on the dielectric layer located on the sustain electrode pairs. As a result, the display luminance level is increased, increase in the scale of power source circuit can be avoided, and a wide drive margin can be obtained.

Plasma display device and drive method for use in plasma display device

A plasma display device is provided which is capable of expanding an ensured operating temperature range or operating life time even at time of changes of a driving margin induced by a panel temperature or cumulative operating time of the panel. Display is controlled in a scanning period during which writing discharge is made to occur in a cell, in a sustaining period during which a cell having undergone writing discharge is turned ON for displaying, and in an initializing period during which wall charges in a cell and space charges accumulated before the scanning period starts are initialized. A wall charge adjusting period during which a potential difference between scanning electrodes and data electrodes varies gradually is set and a change rate of a potential between scanning electrodes and data electrodes during the wall charge adjusting period is changed according to the panel temperature and/or cumulative operating time of the panel.

Plasma display device and method for driving the same

In a three-electrode AC plasma display panel, a plurality of X electrodes () and a plurality of Y electrodes () are alternately arranged parallel to each other on one of two, front and rear insulating substrates () opposing each other, and a plurality of data electrodes () are arranged on the other insulating substrate to cross the X and Y electrodes () at right angles. In this panel, cell separation partition walls () are arranged on the front insulating substrate, on which the X and Y electrodes () are arranged, along the X and Y electrodes (). In a driving method for the three-electrode AC plasma display panel, progressive display is performed depending on whether discharge simultaneously occurs between all the adjacent pairs of X and Y electrodes ().

AC plasma display panel and driving method therefor

A method for driving a plasma display device is provided which is capable of causing writing discharge to normally occur. A sub-field includes an initializing period, a scanning period during which video data to display a video is written in a discharge cell by causing writing discharge to occur between a scanning electrode and a data electrode, and a sustaining period during which sustaining discharge to cause the discharge cell in which a writing discharge has occurred to emit light in a manner to correspond to video data is made to occur between the scanning electrode and a sustaining electrode. The initializing period includes a wall charge adjusting period during which wall charge adjusting discharge to adjust charges accumulated between the scanning electrode and the sustaining electrode is made to occur, a sustaining erasing period, a priming period, and a priming erasing period.

Driving method for AC-type plasma display panel and plasma display device

A method for driving an AC plasma display panel which makes it possible to reduce flicker in display and have stable and high luminance. In a first step, a wall charge of same amount is produced both in an X electrodeand a Y electrodeby writing discharge during a scanning period. At this time, the amount of the wall charge is adjusted depending on gray scale to be displayed. In a second step, during a sustaining period, a timing of a start of the sustaining discharge is changed by changing a sustaining start control voltage as a voltage of a data electrode. Gradation sequence are displayed through the above steps.

Drive method of AC type plasma display panel

In a priming erasing period, a voltage Vpeis applied to a common electrode, and after an electric potential of a scanning electrode is discontinuously lowered to a positive electric potential lower than the voltage Vpe, the electric potential is continuously lowered to a voltage Vpe. In this case, an electric potential difference between the voltage Vpeand the voltage Vpeis set equal to a firing voltage. Also, an electric potential of the scanning electrode at an end of the priming erasing period is set higher than an electric potential of a data electrode by approximately 20 V. With this operation, there is provide an AC-type plasma display panel having an extended driving margin (range) of a sustaining voltage and capable of being driven by a low voltage.

Driving method for AC-type plasma display panel

By a method of the present invention, each field is made up of at least one sub-field, a sub-field of which is made up of a preliminary discharge period, a scanning period, and a sustaining period, the preliminary discharge period of which is made up of a sustaining erasing period, a priming period, and a priming erasing period, the sustaining erasing period of which is made up of a fist sustaining erasing period and a second sustaining erasing period. Negative wall charges are formed over both a scanning electrode and a common electrode in a display cell where sustaining discharge has occurred in an immediately preceding sub-field in the first sustaining erasing period and then are adjusted so that they may have almost the same amount in the second sustaining erasing period.

AC-type plasma display panel and method for driving same

A method for driving an address-display separated-type AC (Alternating Current) PDP (Plasma Display Panel) is provided which is capable of having sequentially and continuously wall charges be formed sufficiently on a scanning electrode and sustaining electrode even when a width of a scanning pulse is shortened. Driving operations of a scanning driver and sustaining driver for the scanning electrode and the sustaining electrode during a pre-discharge period are the same as those employed in the conventional method. Driving operations for the scanning electrode during a scanning period are also the same as those in the conventional method except following. At ending time of a period during which a scanning pulse is applied to the scanning electrode, a potential difference obtained by superimposing a writing wall charge forming pulse on a sustaining pulse is applied for 3 &#x3bc;sec to 5 &#x3bc;sec. At an ending time of the application of the potential difference, wall charges having amounts larger than those achieved by the conventional method can be accumulated on the scanning electrode and the sustaining electrode.

Method for driving address-display separated type AC plasma display panel and driving device using same

The number of X electrodes of a PDP to be driven is m, the number of Y electrodes of the same is m+1, and they are alternately disposed at equal intervals. The intersections (2m&#x2212;1) between all the X electrodes and Y electrodes and the data electrodes (n) form each cell, and a total of (2m&#x2212;1)&#xd7;n pixels exist. Wall charges with the same polarity and the same amount are formed on the X electrode and Y electrode within one cell while surface discharge occurs between the X electrode and Y electrode, and lighting and non-lighting is distinguished based on the wall charge amount. The surface discharge is set so as not to occur when either the X electrodes or Y electrodes only change their voltages.

Plasma display panel with number of scanning drivers reduced by using progressive drive method

A method of driving an ac-discharge type PDP is provided, which ensures a satisfactorily long sustain period and prevents the luminance of the display screen from lowering even if the count of the scan lines is increased. The PDP has row electrodes and column electrodes that form pixels arranged in a matrix array, and a dielectric layer formed to cover the pixels. In the step (a), scan pulses are applied successively to the row electrodes while data pulses are applied to the column electrodes according to a display signal in a scan period, thereby generating wall discharge in the dielectric layer due to writing discharge. The amount of the wall charge in each of the pixels varies according to the display signal. In the step (b), conversion discharge is caused in a conversion period after the scan period, thereby decreasing the amount of the wall charge in the pixels. The conversion discharge is caused in a different state in each of the pixels according to the amount of the wall charge. In the step (c) sustain pulses are applied to the row electrodes in a sustain period after the conversion period, thereby causing sustain discharge. The sustain discharge occurs in part of the pixels according to the state of the conversion discharge that has been caused in the conversion period, resulting in emission of light.

Ac-discharge plasma display panel

Method of driving ac-discharge plasma display panel

Method of driving AC-discharge plasma display panel

In a tablet integrated type liquid crystal display apparatus, a first transparent substrate is provided on a view side. The first substrate is a plastic substrate having a thickness equal to or thinner than 0.6 mm, and a counter electrode is formed on the first substrate. A second substrate on which a driving layer composed of switching elements and pixel electrodes respectively connected to the switching elements is formed. The second substrate is a glass substrate having a thickness in a range of 0.6 mm to 1.1 mm. A guest host liquid crystal layer sandwiched by the first substrate and the second substrate such that the guest host liquid crystal is driven by a voltage applied between the counter electrode and the pixel electrode. A tablet electrode layer may be provided between the first substrate and the counter electrode.

Tablet integrated liquid crystal display apparatus with less parallax

In an LCD, there is used a GH-mode liquid crystal of which change in transmittivity due to variation in gap thickness is less than that of the conventional TN liquid crystal. A tablet facility is directly arranged or electrodes having the function of the tablet are formed over or below the liquid crystal. Thanks to the structure, this protection plate conventionally required to prevent the change in gap thickness resulting due to pressure of a pen input device applied to the LCD can be eliminated. Consequently, it is possible to reduce weight, volume, and parallax of the LCD. An active matrix LCD with integrated table-type input device is attainable in a simple configuration without increasing weight and volume thereof.

Growing community of inventors

Tokyo, Japan

Eishi Mizobata