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:
Dec. 01, 1998
Filed:
Aug. 15, 1997
Kabushiki Kaisha, Topcon, Tokyo, JP;
Abstract
An objective refraction measurement apparatus includes a separate chart having a pair of charts arranged separately, an optical system for projecting the separate chart to an eye to be examined through a focusing lens and a diaphragm having a pair of through holes arranged corresponding to the separate arrangement of the pair of charts, an operating unit for performing focusing operation to the eye, and a control unit for moving the focusing lens on the basis of the focusing operation along the optical axis direction by the operating unit to obtain the projection images of the pair of charts in the separate chart to the eye in an identical condition or a non-identical condition, thereby to perform a subjective measurement of the eye.