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. 24, 2001
Filed:
Apr. 22, 1999
Nobuhiro Morita, Yokohama, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
Transmission light from a detection lens is directed to a polarization element as incident light. The polarization element is rotated, and the light is received and detected by an array-state light-receiving element, and the birefringence of the detection lens is calculated. The distance between a lens for radiating the diffusion light onto the detection lens and the detection lens itself can be optionally set. Observing the transmission image of the detection lens, the distance between the detection lens and the lens is determined. Thereby, it is possible to obtain optical elasticity interference fringes which at most are scarcely affected by optical distortions. In addition, a focusing magnification rate is most suitably set to match states of birefringence occurrence which are different in accordance with the detection lens or the placement thereof. A compensation optical system composed of a lens respectively has different focal distances f1 and f2 in the main scanning direction and in the subscanning direction, and can be added into a space between the radiation optical system and the detection lens. The light from the detection lens is substantially parallel.