Patent · US Expired

Compact disc (CD) player and method of compensating for tracking jumps

US4796247A · kind A · utility

56Cited by
1References
22Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 27, 1987
Grant dateJan 3, 1989
Priority date
Expiry dateMay 27, 2007

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S358/907
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

To provide for continuity of audio output from a compact disc (CD) player, installed in an environment subject to shock or vibration, for example in a motor vehicle, the CD player includes an extra write-read memory (31), placed in the signal processing path of a signal scanned by an optical scanning system to a digital/analog converter in advance of an audio output system (AR), a repositioning system (36) to reposition the optical scanning optical system on a track which may have been lost due to a jolt or vibration, and a synchronizing system to synchronize writing in the write-read memory after repositioning of the optical scanning system at the end of previously written data in said write-read memory immediately in advance of tracking loss. Tracking loss can be sensed by determining loss of information data, or sensing of a scanning beam from the optical scanning system impinging on the mirror surface of the CD, with the number of tracks being jumped being determined by comparing timing data included in the CD scanned data with previously recorded data to thereby determine the length of track, and hence the number of track spirals which were skipped or jumped. Preferably, scann…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.