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:
Apr. 25, 2000
Filed:
Sep. 09, 1997
Applicant:
Inventors:
Kazutake Boku, Osaka, JP;
Shusuke Ono, Osaka, JP;
Assignee:
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
359566 ; 359565 ; 359569 ; 359570 ; 359571 ; 359742 ;
Abstract
An optical system that can be used in an optical imaging system and displays good imaging performance with corrected chromatic aberration without increasing the number of lenses is provided by employing a lens surface with a diffractive effect. The optical system uses a lens with a concave incident surface and positive refractive power. A grating element surface 40 with positive refractive power is formed on at least one surface of the lens. The surface on which the grating element is formed is an aspherical surface with a radius of curvature that becomes bigger with increasing distance from the optical axis.