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. 24, 1998
Filed:
Oct. 17, 1997
Heihachiro Ebihara, Tokorozawa, JP;
Citizen Watch Co., Ltd., Tokyo, JP;
Abstract
The present invention improves the drop of a contrast, the occurrence of cross-talk and the drop of a response speed by bringing the drive state of an electrooptical display device to theoretical values. In a display device including a display panel having common electrode groups and segment electrode groups, a common electrode drive circuit and a segment electrode drive circuit, the quantity of the current flowing through the display panel through the segment electrode drive circuit is detected by a current detection circuit consisting of a differential amplifier 101 and a resistor Ra and by a current detection circuit consisting of a differential amplifier 102 and the resistor Ra, and the common electrode drive voltage applied to the common electrode groups through the common electrode drive circuit is controlled by a differential amplifier 103 on the basis of this current detection quantity, whereby the contrast is improve cross-talk is eliminated, and remarkable effects are obtained.