Method and apparatus for recording data on recording medium
Patent 5557594 Issued on September 17, 1996. Estimated Expiration Date: 
December 21, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
December 21, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesMethod of coding binary data Digital sum value corrective scrambling in the compact digital disc system Method of dc-free 8/9 nrz coding using a unique sync word pattern Data converting apparatus Modulator circuit for a recording for a digital recording medium Patent #: 5349349 InventorsAssigneeApplicationNo. 360349 filed on 12/21/1994US Classes:369/59.24, During storage341/58, To or from minimum d.c. level codes360/40In specific code or formExaminersPrimary: Epps, GeorgiaAssistant: Huber, Paul W. Attorney, Agent or FirmForeign Patent References
International ClassG11B 007/013Foreign Application Priority Data1993-12-21 JPAbstractTo improve the reliability of reproduction by performing signal processing so that substantially (almost) all DC is eliminated when digital data is recorded on a recording medium such as a magneto-optical disk. When data is recorded on a recording medium such as a magneto-optical disk, generally the digital data is modulated and encoded before being recorded, but sometimes the modulation code is not DC free due to a recording channel code of an NRZI system, etc. According to the present invention, data is divided into parts each having a certain constant length so as to prevent the DC component from building up. A resynchronization signal RESYNC is inserted in the break between the parts, the data is preliminarily modulated and encoded subsequent to the RESYNC, the DC component thereof is counted, and the pattern of the RESYNC is changed in the direction so that the phase becomes a minus value when the sum of the DC components DSV (digital sum value) up to before that RESYNC is a plus value and becomes a plus value when the sum is a minus value, that is, the DSV converges to zero, and the changed data is subjected to modulation and encoding, thereby to reduce the DC component of the recording data.Other References
Field of SearchCONVERTING AN ANALOG SIGNAL TO DIGITAL FORM FOR RECORDING; REPRODUCING AND RECONVERTINGIn specific code or form GENERAL PROCESSING OF A DIGITAL SIGNAL Nonreturn to zero To or from minimum d.c. level codes To or from run length limited codes To or from NRZ (nonreturn-to-zero) codes Return-to-zero to or from NRZ (nonreturn-to-zero) codes | |
