Optical disc scanning arrangement - uses main scanning beam and two tracking beams displaced by half track width

摘要

Tracks (S) are spaced (R) in a combination optical and magneto-optical disc. Three light beams (L1, L2, L3) are used including a main scanning beam (L1). The positive refraction (L2) and negative refraction (L3) beams are arranged such that each covers half the data track (S) of the recording medium. USE/ADVANTAGE - Magneto-optical discs. Allows 'push-pull' tracking procedure with offset compensation for high density discs.