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. 21, 2010
Filed:
Jun. 26, 2008
Toshitaka Matsunaga, Akishima, JP;
Masahide Yatsu, Akishima, JP;
Hideo Sado, Ome, JP;
Katsuki Ueda, Tachikawa, JP;
Shouji Nakajima, Kodaira, JP;
Seiji Mizukoshi, Nishitama-gun, JP;
Shinichirou Kouhara, Hino, JP;
Toshitaka Matsunaga, Akishima, JP;
Masahide Yatsu, Akishima, JP;
Hideo Sado, Ome, JP;
Katsuki Ueda, Tachikawa, JP;
Shouji Nakajima, Kodaira, JP;
Seiji Mizukoshi, Nishitama-gun, JP;
Shinichirou Kouhara, Hino, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
According to one embodiment, a disk drive having a disk, a read head, a servo controller, and a CPU. In the disk, a multi-spiral servo pattern is recorded. The read head reproduces a hexagon-shaped detection signal from the multi-spiral servo pattern. The servo controller generates amplitudes values for respective frames, from the multi-spiral servo pattern. The CPU performs positional-error calculation by using the amplitude values for the frames. Upon detecting a positional change of the head is detected, the CPU performs the positional-error calculation by using the amplitude values generated at the time of replacing the frames with other frames, and corrects the positional error by adding an offset determined from the positional change of the head, to the result of the positional-error calculation.