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:
Dec. 09, 2008
Filed:
May. 02, 2005
Applicants:
Hsueh-wu Hao, Jhubei, TW;
Kuang-jung Chang, Taipei, TW;
Inventors:
Hsueh-Wu Hao, Jhubei, TW;
Kuang-Jung Chang, Taipei, TW;
Assignee:
Mediatek Inc., , TW;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03K 5/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
The present invention provides a filtering device for high-pass filtering a signal reproduced from an optical data storage medium and a method for the same. More particularly, the present invention provides a device for suppressing the variation of DC level of a quad sum signal or a push-pull signal. The filtering device is adapted to have a higher cutoff frequency for speedily reacting to suppress the DC level change, especially when the pickup head is crossing from the data field to the header field.