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. 10, 1981
Filed:
Apr. 21, 1980
Applicant:
Inventors:
Mitsugu Aoki, Tokyo, JP;
Yoshinori Oana, Tokyo, JP;
Yasuo Kato, Tokyo, JP;
Taketoshi Ishihara, Tokyo, JP;
Assignee:
Tokyo Kogaku Kikai Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
A61B / ;
U.S. Cl.
CPC ...
351 30 ; 351 27 ;
Abstract
A vision testing instrument has a projecting optical system for projecting a test chart to produce an aerial image. In the optical system, there is provided a focusing reflector for producing a chart image at a far point. A second focusing reflector is provided so that it can be retractably inserted into the projecting optical path for producing a chart image at a near point.