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:
Sep. 11, 2007
Filed:
Sep. 08, 2003
Daiji Kitagawa, Tenri, JP;
Toshiya Aoki, Kashiba, JP;
Daiji Kitagawa, Tenri, JP;
Toshiya Aoki, Kashiba, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
In a buffer that outputs an analog voltage Vout to be applied as a driving voltage to a pixel capacitance in a display region of an active-matrix liquid crystal display device, a CMOS circuit for generating this analog voltage includes four Pch transistors (QPto QP) connected in parallel and four Nch transistors (QNto QN) connected in parallel. When charging the pixel capacitance, a bias current is reduced and the driving capability is lowered by control with selector switches (SPto SP) at a time at which the large driving capability at the beginning of the charging is not necessary anymore. And when discharging the charge that has accumulated at the pixel capacitance, the bias current is reduced and the driving capability is lowered by control with selector switches (SNto SN) at a time at which the large driving capability at the beginning of the discharging is not necessary anymore. With this configuration, it is possible to reduce the power consumption of the output buffer applying the analog voltage for image display to the capacitive load in the display panel.