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:
Nov. 05, 1996
Filed:
Jun. 30, 1994
Tatsuro Otaki, Tokyo, JP;
Takashi Kawahito, Fujisawa, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A differential interference microscope which includes a light source, a condenser optical system for condensing beams of light from the light source and illuminating an object with the beams of light, an objective optical system for converging the beams of light from the illuminated object and forming an image of the object, a pick-up device for photoelectrically detecting the image of the object, and a contrast enhancement circuit for enhancing a contrast of the image on the basis of an output signal of the pick-up device. A first polarizing element and a first birefringent element are disposed sequentially in an optical path between the light source and the object. The first polarizing element changes the beams of light from the light source into predetermined beams of polarized light. The first birefringent element separates the polarized light into an ordinary ray and an extraordinary ray. A second birefringent element and a second polarizing element are disposed sequentially in an optical path between the object and the image. The second birefringent element guides the two light beams from the object onto the same optical path. The second polarizing element causes the two light beams guided onto the same optical path to interfere with each other. The shear quantity S between the ordinary ray and the extraordinary ray satisfies the following condition: