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.:

US 7440373 B1

PDF
Full Text
Expired
Date of Patent:
Oct. 21, 2008

Filed:

Feb. 05, 2004
Applicant:

Harutaka Sekiya, Tsurumi-ku, JP;

Inventor:

Harutaka Sekiya, Tsurumi-ku, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B 7/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

An optical disk drive capable of detecting a surface deviation of a disk during a very short period includes an analog-to-digital converter (ADC) converting a focus error signal output from a pickup into digital data, and a central processing unit (CPU) writing an output of the ADC to a memory during one rotation of a motor according to a timing of a pulse signal output from a spindle motor. After that, the CPU reads data written to the memory and obtains a sine curve that minimizes the sum of squares of errors among data by a least square method. The CPU obtains a peak-to-peak value of the obtained sine curve and compares the peak-to-peak value to a predetermined threshold value, thereby determining the existence of the surface deviation of the disk.


Find Patent Forward Citations

Sekiya, Harutaka. (2008). Optical disk drive detecting disk surface deviation (U.S. Patent No. 7440373). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/7440373

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