Candescent Technologies Corporation

Paul Freiberg

Ronald L Hansen

Jay Friedman

A circuit and method for time multiplexing a voltage signal for controlling the color balance of a flat panel display. Within an FED screen, a matrix of rows and columns is provided and emitters are situated within each row-column intersection. Row drivers are sequentially activated during 'row on-time windows' and corresponding individual gray scale information (voltages) are driven by the column drivers. When the proper voltage is applied across the cathode and anode of the emitters, electrons are released toward a phosphor spot, e.g., red, green, blue, causing illumination. Within each column driver, selection circuitry is provided for driving a first voltage data during a first part of the row on-time window and a second voltage data during a second part of the row on-time window. The lengths of the first part and second part of each row on-time window can be adjusted, for a given color, to adjust the color balance with respect to that color. In one embodiment, two data translators or 'error compensation circuits' are used to compensate for errors caused by dividing the first voltage data when obtaining the second voltage data. Considering consecutive frame pairs, a first error compensation circuit is operable during the first frame of each frame pair and generates a second voltage data having negative error. A second error compensation circuit is operable during the second frame of each frame pair and generates a second voltage data having positive error. Statistically, the negative and positive errors cancel although different color data is presented at a same pixel from one frame to another.

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Palo Alto, CA, United States of America

Paul Freiberg