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. 05, 2008
Filed:
Dec. 15, 2005
Tomohiro Sakurada, Tokyo, JP;
Tomohiro Sakurada, Tokyo, JP;
Kabushiki Kaisha Topcon, Tokyo, JP;
Abstract
The optometry apparatus includes an index projecting optical system for projecting an index for cross cylinder test to an eye for shortening examination time, a variable cross cylinder lens disposed on an optical axis of the index projecting optical system, for forming one pair of projection images of the index by switching of an astigmatic axial angle while predetermined astigmatic power is set, a joystick lever and a button used to input a result of comparison between appearance states of the pair of projection images of the index, and an initial value setting unit for determining an astigmatic axial angle of the variable cross cylinder lens to cause one of the pair of projection images of the index visually recognized and to cause the other thereof in a blurred state based on objective values of astigmatic power and an astigmatic axial angle of the eye, measured in advance, and for setting the determined astigmatic axial angle as an initial value for astigmatic axial angle measurement.