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:
May. 13, 1997
Filed:
Dec. 14, 1995
Applicant:
Inventor:
Ryoichi Mori, Bunkyo-ku, Tokyo, JP;
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 59 ;
Abstract
Bit '0' and bit '1' constituting a digital signal are replaced with extended length binary coded signals. For example, bit '0' of the digital signal is replaced with '011', and bit '1' with '110'. The replaced signals are recorded in a non-rewritable recording medium. A bit '0' of the recorded signal does not change a status of the recording medium whereas a bit '1' of the recorded signal changes the status of the recording medium. Unauthorized change of the data recorded in the recording medium can be recognized if the data read on a three-bit basis indicates '111'. A header may be additionally recorded in the recording medium to store status of the data recorded therein.