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:
Oct. 07, 1997
Filed:
Apr. 27, 1995
Yoshimi Kohayakawa, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An ophthalmic apparatus includes a visual target indicating portion for indicating patterns of at least three directions each consisting of a plurality of parallel lines, a visual target optical system for making variable a diopter of the pattern presented to an examinee, and a response inputting device for inputting a response of the examinee. A refractive power of an eye of the examinee is obtained from a diopter of the pattern at the time the examinee inputs a response thereof through the response inputting device at the limit of his visual recognition of the pattern. In another arrangement, a refractive power of an eye of the examinee is obtained from intervals of the parallel lines at the time the examinee inputs a response thereof through the response inputting device at the limit of visual recognition of the pattern, the intervals of the parallel lines of which change over time.