Patent ID: 7586817

Claim:
Appliance for recording or playing back information having means for detecting or moving the scanning location on a disc with a wobble track providing a wobble signal recorded at a constant linear speed in the wobble track on the disc with a predetermined wavelength of said wobble track, said disc is scanned at a predetermined number of revolutions per time unit of the disc using a scanning device, and a wobble frequency contained in said wobble signal detected from said disc is used for detecting or moving the position of said scanning device, wherein the move of the location of the scanning device to a location on the disc to be scanned by the scanning device is performed by using a ratio between the wobble frequency detected with the scanning device from the disc and the number of revolutions or rotation speed of the disc in that the wobble frequency expected at the location on the disc to be scanned by the scanning device is calculated for said number of revolutions or rotation speed of the disc and the scanning device is moved to the location where the calculated wobble frequency being detected from the disc with the scanning device.