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:
Aug. 28, 1984
Filed:
Jul. 31, 1981
Applicant:
Inventor:
Kazuo Nunokawa, Tokyo, JP;
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
A61B / ;
U.S. Cl.
CPC ...
351206 ; 351208 ;
Abstract
A working distance detecting device for ophthalmic instruments has two annular slits in the illuminating system. One of the annular slits has a light-shading portion of a predetermined width. A light-receiving portion is provided around the object lens so as to receive beams of light reflected at the cornea of the eye to be examined. The working distance can be detected at the light-receiving portion by the image of the light-shading portion of the annular slit.