Patent · US Expired

Deflection plate for optical pick-up device

US5475670A · kind A · utility

33Cited by
16References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 29, 1993
Grant dateDec 12, 1995
Priority date
Expiry dateSep 29, 2013

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B7/1353
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A deflection plate for deflecting laser beams includes a transparent plate on which two grating areas are formed on the same surface. The first grating area has a plurality of parallel grooves. The second grating area has a plurality of grooves in a predetermined pattern. The depth and/or the duty ratio of the grooves in the first grating area differs from that in the second grating area.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.