METHOD AND DISK-TYPE DATA MEDIUM FOR TRACKING DATA TRACK OF DISK-TYPE OPTICAL- RECORD MEDIUM Russian patent published in 2002 - IPC

FIELD: data recording and reproducing on optical disks. SUBSTANCE: data medium carries mirror layer opposing data one. Source radiation is focused by means of optical system in vicinity of mirror layer. Reflected radiation is conveyed to data layer. Optical record medium has its data track tracking means made in the form of optical member of x1 magnification, such as bi-convex lens, gradient-index lens, Fresnel lens, or hologram component, disposed in center of medium symmetrically to axis of its revolution. Optical system parameters meet relationships given in description of invention. Thanks to this any variations in spatial position of medium data surface due to vibrations or any other causes are compensated for by respective variations of mirror layer and optical member thereby ensuring autotracking simultaneously with automatic focusing without using inertial tracking systems thereby enabling increase of data exchange speed up to 100 Mbyte/s for optical disks. EFFECT: simplified design, enhanced data exchange speed of optical disks. 9 cl, 4 dwg