The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 14, 1987
Filed:
Feb. 13, 1985
Applicant:
Inventors:
Assignee:
Pioneer Electronic Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ;
U.S. Cl.
CPC ...
369 45 ; 250201 ; 346 / ; 369110 ; 369111 ; 369116 ;
Abstract
An apparatus for recording pits and grooves on the surface of a recording medium such as an optical disk in which the pits and grooves are formed by separate light sources, thereby providing accurate control over the dimensions of both the pits and grooves. Light beams of separate wavelengths suitable for forming the pits and grooves are passed through respective optical modulators and continuously variable beam expanders, and then combined and applied through a focusing lens to the recording medium. A beam monitor and a focus monitor receive part of the light reflected from the surface of the disk to control the focus and beam size conditions.