In an optical recording medium a substrate is provided having at least a recording surface and a recording layer on an area of the recording surface having a length in a longitudinal direction. A set of linear continuous tracking tracks is formed on the recording surface. The tracking tracks have a length...http://www.google.de/patents/US5070490?utm_source=gb-gplus-sharePatent US5070490 - Optical recording medium with tracking tracks extending beyond the recording layer and a method for detecting tracking signal from said medium
