International Business Machines Corporation

Albert O Piston

Tony N Criscimagna

Thomas Albert Sherk

Low cost apparatus for a gas display panel is operated by a method to provide reliable write, sustain, and erase operations. For sustain operations a first square wave train is applied to all horizontal lines of the gas display panel simultaneously as a second square wave train, displaced 90.degree. from the first square wave train is applied to all vertical lines. For a write operation the frequency of the first and second square wave trains is reduced, and a pulse is superimposed or algebraically added to the sustain signals which results in a composite signal. The superimposed signal (a) increases the potential on a selected horizontal line, (b) decreases the potential on the remaining horizontal lines, (c) decreases the potential on a selected vertical line, and (d) inceases the potential on the remaining vertical lines. The selected cell receives an increased potential difference sufficient to equal or exceed the ignition potential after all of the remaining cells receive a sustain potential which ignites all cells which were previously ignited. The algebraically added pulses cancel out the effect of each other across the half selected cells and the non selected cells. For an erase operation a given signal of constant magnitude and polarity is applied to all horizontal lines and all vertical lines, and a pulse is algebraically added on the given signal which (a) increases the potential on a selected horizontal line, (b) decreases the potential on the non selected horizontal lines, (c) decreases the potential on a selected vertical line, and (d) increases the potential on the non selected vertical lines whereby no gas cell in the gas panel receives a potential difference sufficient to equal or exceed the sustain level. However, the selected gas cell, and only this gas cell, receives a potential difference having a polarity opposite to that of the last sustain signal and an amplitude that is just barely sufficient to fire the cell, and this is effective in reducing the charge sometimes referred to as the wall charge, across the selected gas cell substantially to zero. After a suitable time delay, referred to as dead time, the wall charge across the selected gas cell is reduced to zero, and the selected gas cell thus is returned to the extinguished state. A sustain operation then takes place which reignites all gas cells previously ignited before the erase operation except the selected erased cell. The algebraically added pulses cancel out the effect of each other across the half selected cells and the non selected cells.

Method and apparatus for gas display panel

In plasma display panels requiring interstitial spacer elements within the display area to provide and maintain a uniform discharge gap, the spacers are positioned between lines which constitute the display. The lines adjacent the spacer elements experience a significant decrease in operating margin. This margin decrease is compensated for by either jogging the lines adjacent the spacers outwardly, by widening the lines in the affected areas or a combination of both. Various embodiments for providing this compensation are illustrated and described.

Modified conductor array for plasma display panel

A system for addressing and controlling a gaseous discharge display or memory device is adapted for intercommunication between a processor or controller, control logic and panel driving circuits in a gaseous discharge display system. By application of write and systain signals to selected transverse conductors disposed on opposite sides of a gas filled panel, selected sites positioned at conductor intersections are discharged, emitting light, and the resultant display maintained by the wall charge phenomenon and sustain signals. Logic circuits and panel drive circuits are electrically floated on the sustain voltage for the panel whereby the sustain signal provides a common reference, thus permitting the use of low voltage circuits particularly adapted to integrated circuit packaging. Coupling means are employed to isolate the signals from the logic control from the panel selection, control and drive circuits, permitting control of the high voltage panel operation by low level coded signals. By utilizing a pulsed supply for line drivers rather than a fixed power supply, power and heat dissipation are further reduced, thereby facilitating integrated circuit packaging. The preferred embodiment of the present invention is adapted to write, sustain and erase a gaseous discharge panel.

Floating addressing system for gas panel

A modular control system is provided for a gas panel of the type having an array of row wires and column wires that form light emitting cells at their crossover points. A row counter and a column counter provide selection signals for entering characters sequentially on the panel. The counters provide borrow and carry signals to components that control the display. Thus, the control operates without regard to the actual size of the display and provides a modular construction for displays of various sizes.

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Catskill, NY, United States of America

Albert O Piston