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:
Oct. 14, 2003
Filed:
Dec. 07, 1999
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
A liquid crystal driving integrated circuit capable of adjusting display contrast and requiring no externally attached components. Transmission gates TG -TG are provided at respective connection points of twelve resistor elements connected in series between a power supply and the ground. One of the voltages V -V derived from the transmission gates TG -TG in accordance with control signals CA -CA is applied to an operational amplifier and used as a reference voltage VLCD . The control signals CA -CA are obtained by decoding control data D -D supplied from an external source by a decoder Therefore, the reference voltage VLCD can be set in a plurality of stages simply by changing control data D -D to a user specified value. As the twelve resistor elements connected in series are formed on the same semiconductor substrate, display contrast can be adjusted without requiring any external components attached to a liquid crystal driving integrated circuit