Optical scanning device having less response to stray reflections that information layer reflections

摘要

An optical scanning device incorporating a compound objective lens 10 and a radiaion detector 31 is described for reading an optical record carrier 1 in which the optical record carrier 1 is provided with a transparent layer 2 . The thickness of the transparent layer 2 and the effective radius of the detector 31 are adapted such that the signal-to-noise ratio of the device is significantly improved and/or local heating of an air gap below an air slider is reduced. The optical record carrier is provided with a lubricant to facilitate the use of a slider optical head 40.