A disc recording and/or reproducing apparatus for recording and/or reproducing information signals on or from an optical disc on which there is formed a spirally extending recording track is disclosed. The apparatus includes fundamental clock generating circuits for generating fundamental clocks CK.sub.A...http://www.google.com.hk/patents/US5436878?utm_source=gb-gplus-share專利 US5436878 - Disc recording and/or reproducing apparatus for permitting continuous sector processing at boundaries between recording regions with different recording densities
