OPTICAL PICKUP FOR OPTICAL DISC HAVING NARROW TRACK

摘要

PURPOSE: An optical pickup for an optical disc having a narrow track is provided to obtain information stored to a target track from a single light beam reflected from the target track even though the width of the track is reduced to increase the data storing capacity. CONSTITUTION: An optical pickup for an optical disc having a narrow track includes a light source(1), a beam splitter(3), a reflection mirror(4), an objective lens(5), a light receiving lens(7), a light shielding plate(42), and an optical detector(48). The light shielding plate is positioned on the light path between the light source and the beam splitter, and has a light shielding portion in the shape of ring for reflecting the incident light beam totally. The light shielding plate transmits light beam through the other portions except the light shielding portion, so that the beam spot focussed to a target track has the maximum intensity.