OPTICAL SCANNING MEANS

摘要

The application relates to an optical scanning device for realising in a recording layer of an optical tape (109) a longitudinal path of substantially parallel tracks (120). The device comprises an optical system (101, 107) for focusing a radiation beam (102) at the recording layer. The radiation beam (102) causes a scanning spot (111) to develop on the layer. The optical tape (109) is cyclically scanned by a polygon mirror (107) via the scanning sport (111). The optical tape (109) is displaced relative to the optical system in a direction transverse to the scanning direction (y). The device further comprises optoelectrical measuring means (140) for deriving a measuring signal indicative of the track pitch of successive tracks (120) from the track pattern. The velocity of the optical tape (109) is controlled as a function of this measuring signal.