Nondestructive cursors in AC plasma displays
AssigneeInternational Business Machines Corporation
InventorsEugene Stewart Schlig, George Raymond Stilwell, Jr.
Life of this patent
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Abstract
A nondestructive, transparent cursor for AC plasma displays may be superimposed electronically over a displayed image without regenerating the original image each time the cursor is moved. The cursor is displayed by means of a special cursor drive waveform which discharges both previously "on" and "off" cells which form the cursor but permits reversion of the cells to their original state when the cursor drive waveform is removed and the normal sustaining waveform is restored.
Claims22
A method of causing light emission from selected cells of an AC gas discharge display panel without loss of the previous memory state of said selected cells by applying a voltage waveform thereto comprising successive voltage complexes each having, at least a first component of at least one voltage level having a magnitude approximately equal to that of the magnitude of the sustain voltage level V.sub.s for said display panel, at least a second component of at least one voltage level having a polarity the same as the polarity of said at least one voltage level of said first component and a magnitude approximately equal to twice that of the sustain voltage level V.sub.s, and at least a third component of at least one voltage level approximately equal to zero volts.
A method of forming a cursor on the display panel of an AC gas discharge display and memory system comprising:
- applying successive voltage complexes across the display panel cells selected to form said cursor so as to cause light emission therefrom without a loss in the previous memory state of said cells,
- each of said voltage complexes including at least,
- a first component of at least one voltage level of a magnitude approximately equal to the magnitude of the sustain voltage level V.sub.s for said display panel,
- a second component of at least one voltage level of a polarity the same as and a magnitude approximately equal to twice that of the sustain voltage level V.sub.s for said display panel, and
- a third component of at least one voltage level of approximately zero volts.
In an AC gas discharge display system including an AC display panel and drive circuitry means therefor with said driver circuitry means having both horizontal and vertical drive circuitry means for providing addressing and sustain pulses to the respective horizontal and vertical lines of said panel, the improvement comprising a drive circuitry arrangement for providing a nondestructive cursor to said panel, said drive circuitry arrangement comprising, pulse means in each of said horizontal and vertical drive circuitry means for providing voltage complexes to particular ones of said horizontal and vertical lines to form said nondestructive cursor, said pulse means providing voltage complexes each having at least a first component of at least one voltage level having a magnitude approximately equal to that of the magnitude of the sustain voltage level V.sub.s for said display panel, at least a second component of at least one voltage level having a polarity the same as the polarity of said at least one voltage level of said first component and a magnitude approximately equal to twice that of the sustain voltage level V.sub.s, and at least a third component of at least one voltage level approximately equal to zero volts.
Dependencies are inferred from the claim text.