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:
Mar. 16, 1999
Filed:
Jul. 16, 1997
Applicant:
Inventor:
Hideji Morita, Higashihiroshima, JP;
Assignee:
Sharp Kabushiki Kaisha, Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369112 ; 369 4423 ; 369 4437 ; 369 94 ;
Abstract
An optical recording and reproducing device of the present invention has an objective lens designed so as to form a light spot with a set diameter on a DVD, while to form, on a CD, a light spot with a set diameter different from the above diameter. Respective working distances WD1 and WD2 with respect to the DVD and the CD are set in accordance with deflection standards F for the DVD and the CD, respectively. By doing so, as compared with conventional cases where the deflection standards F are not taken into consideration, the working distance WD1 is decreased. As a result, the device is thinned, compared with the conventional cases.