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:
Oct. 22, 1985
Filed:
Jun. 27, 1983
David M Creed, Basingstoke, GB;
John G Ive, Basingstoke, GB;
Sony Corporation, Tokyo, JP;
Abstract
A method of detecting and correcting errors in digital audio signals comprises assembling digital data words each of which corresponds to a digital audio signal representing an analog audio sample into units of six data words, assembling with each unit six redundant words derived by exclusive-OR operations on the data word in each row and each column of the unit, assembling the data words and redundant words into sub-blocks and adding cyclic redundancy check code words to the sub-block, recording and reproducing each sub-block, after reproduction using the code words of each sub-block to set the logic state of error flags that have been added to each word in the sub-block, re-forming the units and assembling with each reproduced unit horizontal and vertical syndromes derived by exclusive-OR operations on the data words and redundant words in each row in each column of the unit, comparing the horizontal and vertical syndromes and resetting the logic state of the error flags in dependence on this comparison, deriving further horizontal syndromes by exclusive-OR operations on the data words and redundant words in each row of the reproduced unit and where there is only a single word in a row flagged as being in error, correcting that error word using the further horizontal syndrome, and deriving further vertical syndromes by exclusive-Or operations on the data words and the redundant word in each column of the reproduced unit and where there is only a single word in that column in error, correcting that error word using the further vertical syndrome.