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:
Mar. 11, 2008
Filed:
Jun. 24, 2003
Katsuyoshi Hiraki, Kawasaki, JP;
Yasutake Furukoshi, Kawasaki, JP;
Koichi Katagawa, Kawasaki, JP;
Masanori Nishido, Kawasaki, JP;
Tetsuya Kobayashi, Kawasaki, JP;
Katsuyoshi Hiraki, Kawasaki, JP;
Yasutake Furukoshi, Kawasaki, JP;
Koichi Katagawa, Kawasaki, JP;
Masanori Nishido, Kawasaki, JP;
Tetsuya Kobayashi, Kawasaki, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A drive control circuit supplies a gate voltage so that display quality is not degraded even in a case where a vertical scanning frequency or a horizontal scanning frequency is changed. The circuit includes a timing controller for detecting a change of a horizontal scanning frequency, a gate voltage generating circuit for generating two kinds of gate-on voltages Va and Vb (Va<Vb), and a switch for outputting one of the gate-on voltages Va and Vb from the gate voltage generating circuit in accordance with an output of the timing controller. The timing controller includes a counter for counting the number of clocks for one horizontal period, and a comparator for comparing a count result with a threshold value. When the horizontal scanning frequency is in a normal state, the low gate-on voltage Va is outputted, and when the horizontal scanning frequency exceeds a predetermined threshold value, that is, the count value falls below a threshold value, the high gate-on voltage Vb is outputted.