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:
Sep. 26, 1989
Filed:
Oct. 01, 1987
Kazuo Hikawa, Mitaka, JP;
Yasuo Inoue, Yokosuka, JP;
Victor Company of Japan, Kanagawa, JP;
Abstract
A digital signal demodulator is provided for demodulating a reproduced recorded modulated digital signal which includes a parity code. The recorded modulated digital signal has a data code format which may include both valid used data codes and unused redundant phantom codes as a result of an industry standard code format conversion. The digital signal demodulator includes a redundant portion detection circuit which detects whether unused redundant phantom codes are present in the reproduced modulated digital signal data, a demodulating circuit which demodulates the reproduced modulated digital signal, an error detection circuit which effects an error detection using a parity code in the demodulated digital signal to detect erroneous data in the demodulated signal, and a judgment circuit which, when unused redundant phantom codes are detected in the modulated digital signal data, judges the corresponding demodulated digital signal data to be erroneous irrespective of the result of the parity code error detection operation.