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. 08, 2005
Filed:
May. 24, 2002
Takaaki Sakurai, Sagamihara, JP;
Yoshiteru Watanabe, Kawasaki, JP;
Toshiyuki Yana, Yokohama, JP;
Satoshi Karube, Fujisawa, JP;
Takaaki Sakurai, Sagamihara, JP;
Yoshiteru Watanabe, Kawasaki, JP;
Toshiyuki Yana, Yokohama, JP;
Satoshi Karube, Fujisawa, JP;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A liquid crystal power supply is provided which generates a high-precision drive power supply voltage supplied to a driver circuit by using a low-precision reference voltage generating circuit. The power supply circuit includes a DC/DC converter which generates a voltage having a size based on an oscillation signal from a power supply voltage and outputs the generated voltage as a drive power supply voltage; a stabilized power supply circuit which generates a highest-level reference potential for generating a gray-scale voltage in a driver circuit; a comparison unit which outputs a difference voltage according to a difference between the drive power supply voltage and the highest-level reference potential; an internal reference voltage generating unit; an error amplifying unit which amplifies a difference between the reference voltage and the difference voltage; and a PWM conversion unit which outputs an oscillation signal in response to the amplified difference.