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Repetition Rate Reduction to Permit Greater Pel Content in a Plasma Panel

IP.com Disclosure Number: IPCOM000047384D
Original Publication Date: 1983-Nov-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Hoffman, HS: AUTHOR [+3]

Abstract

In a plasma panel the more picture elements (pels) that are lighted, the more current that is drawn. The components have practical design limits, and a warning signal is generated indicating that the current is approaching this limit. The current also increases as a function of the repetition rate of the cycling. Since the intensity also varies as a function of the repetition rate, there is a trade-off between the intensity and the pel content in a plasma display. The warning signal can be used to reduce the effective repetition rate through a feedback mechanism to a point where the warning signal is removed by the repetition rate reduction. By periodically increasing the reduced repetition rate in small steps, the operating condition can be maintained near the maximum tolerable brightness.

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Repetition Rate Reduction to Permit Greater Pel Content in a Plasma Panel

In a plasma panel the more picture elements (pels) that are lighted, the more current that is drawn. The components have practical design limits, and a warning signal is generated indicating that the current is approaching this limit. The current also increases as a function of the repetition rate of the cycling. Since the intensity also varies as a function of the repetition rate, there is a trade- off between the intensity and the pel content in a plasma display. The warning signal can be used to reduce the effective repetition rate through a feedback mechanism to a point where the warning signal is removed by the repetition rate reduction. By periodically increasing the reduced repetition rate in small steps, the operating condition can be maintained near the maximum tolerable brightness. A manual intensity setting can be overridden by this operation such that the desired brightness or less, if forced by excess pel content, will be provided. The feedback can be accomplished with logic or a microcomputer program. A manual approach could use the warning signal to switch the operation to an arbitrarily low repetition rate and latch in this condition. If the manual brightness control is manually turned to its lowest value, the latching will be removed, and at this brightness the warning signal should not be present, thereby regaining manual control. The manual control can now be increased to...