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:
Aug. 04, 1992
Filed:
Apr. 13, 1989
Josephus A Kahlman, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
Apparatus for recording a digital information signal and an auxiliary signal in information tracks of a record carrier without adding the auxiliary signal to the recorded signal. The apparatus converts consecutive information words of the information signal into channel words in accordance with a channel code such that at least three channel words of mutually different disparities are available for such conversion. Selection of a particular channel word for a given information word is determined by a control signal derived from the auxiliary signal and which controls such selection so that the digital sum value (DSV) of the recorded channel words varies substantially in accordance with the auxiliary signal. The control signal is produced from the difference between the auxiliary signal and the DSV of the channel words. Both of the recorded signals can be read by apparatus which converts the recorded channel words into the corresponding information words and also converts the DSV of the recorded channel words into the auxiliary signal.