The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 05, 1996
Filed:
Jan. 18, 1994
Richard A Erhart, Chandler, AZ (US);
Thomas W Ciccone, Paradise Valley, AZ (US);
Vivid Semiconductor, Inc., Chandler, AZ (US);
Abstract
An integrated circuit is provided for generating analog output voltages for a series of column driver output circuits used to drive an active or passive matrix LCD display. The digital value corresponding to the shade of gray for each column is stored on the integrated circuit. A shift register is clocked to sequentially enable tap points of a resistive divider network for providing four monotonically increasing analog voltages on each shift register clock cycle. A binary counter is clocked along with the shift register, and the more significant bits of the stored digital value for each column driver output circuit are each compared with the current binary count to detect a correlation. Upon detecting a correlation, the two least significant bits of the stored digital value for each column driver circuit are used to select one of the four analog voltages during the current counter cycle, and the selected analog value is sampled and held for driving a column of the LCD display.