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. 18, 1995
Filed:
Jun. 22, 1994
Applicant:
Inventor:
Hiroshi Nakanishi, Tokyo, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ; G01D / ; C08F / ;
U.S. Cl.
CPC ...
359642 ; 342258 ; 359196 ; 526282 ;
Abstract
A plastic lens used for an optical system using a laser light source is made of a plastic material having a modulus of photoelasticity at a wavelength of 632.8 nm of larger than zero but no larger than 60.times.10.sup.-13 cm.sup.2 /dyne. The plastic lens satisfies a condition that a product W.times.D/H is larger than zero but no larger than 4, where D is a maximum thickness of the plastic lens along an optical axis in a light beam effective diameter, H is a lens outer diameter and W (%) is a saturation moisture absorption factor as a temperature of 50.degree. C. and a humidity of 95%.