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:
Jan. 09, 2001
Filed:
Nov. 16, 1998
Hideyo Kamiyama, Tokorozawa, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
The upper envelop signal generating unit detects the upper envelop of the detection signal to generate the upper envelop signal corresponding to the detected upper envelop, and the lower envelop signal generating unit detects the lower envelop of the detection signal to generate the lower envelop signal corresponding to the detected lower envelop. The slice signal generating unit divides the voltage difference of the upper envelop signal and the lower envelop signal using a predetermined division ratio to generate the slice signal. The averaging unit averages the slice signal to produce the average signal. The defect detecting unit compares the average signal and the upper envelop signal to produce the defect detection signal indicating the period in which the voltage of the upper envelop signal is lower than the voltage of the average signal. As a result, a very short defect like a wedge-shape defect can be reliably detected.