US 6,310,841 B1 · Optical pickup for narrow track optical discs

Abstract

An optical disc can increase an information storage capacity by reducing the track width of the optical disc. An optical pickup for a narrow track optical disc includes an optical shielding portion having a desired light intensity distribution with respect to a target track and the tracks adjacent to the target track on the optical disc. The optical shielding portion is disposed on the optical path between the light source and the optical disc and shields part of the light beam proceeding toward the optical disc, to provide a light intensity distribution such that only the beam spot focused on the target track is used to detect information stored in the target track. Thus, the beam spot focused on the target track of the optical disc has track crosstalk having a magnitude by which information can be read from the target track. The optical pickup can provide an excellent performance even in the case that the optical pickup is adapted in a high-definition DVD to be commercialized in the future.

Claims17

Dependent claims

An optical pickup recording and/or reproducing data with respect to an optical disc having an information recording surface with a plurality of tracks, the optical pickup comprising:

a light source to emit a light beam;
an objective lens to focus the light beam emitted from said light source on the information recording surface of the optical disc as a beam spot;
an optical detector;
optical path change means for directing the light beam emitted from said light source to said objective lens and directing a light beam reflected from the optical disc and then passed through said objective lens to said optical detector;
and
optical shielding means positioned on an optical path between said light source and the optical disc, for shielding part of the light beam proceeding toward the optical disc from said light source, in such a manner that light intensities of the light beam on tracks adjacent to a target track of the plurality of tracks are substantially zero in a case that the light beam is focused on the target track of the information recording surface by the objective lens.

3 more elements

Dependencies are inferred from the claim text.

Optical pickup for narrow track optical discs

Life of this patent

Optical pickup for narrow track optical discs

Life of this patent

Abstract

Claims17