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:
May. 09, 2000
Filed:
Sep. 29, 1997
Yukio Ikezawa, Tokyo, JP;
Eiichi Yanagi, Tokyo, JP;
Yasufumi Fukuma, Tokyo, JP;
Takeyuki Kato, Tokyo, JP;
Kabushiki Kaisha Topcon, Tokyo, JP;
Abstract
A lens meter is provided in which a measurement light beam emitted from a light source (21) is projected onto a lens (L) to be inspected, an amount in travel of the measurement light beam which has passed through the lens (L) is then detected by a TV camera (34), and the refractive characteristics of the lens (L) based on the detection result are computed by an arithmetic and control circuit (35) and are displayed by a display unit (3). In the lens meter, the arithmetic and control circuit (35) computes cylindrical power of a distance portion (40) of the lens (L) in consideration of cylindrical power and a direction of a cylindrical axis from the detection result of the TV camera (34), and then computes cylindrical power in distortion areas (42, 43) except the distance portion (40), a progressive portion (41), and a near portion (41') in consideration of the cylindrical power and the direction of the cylindrical axis. After that, the arithmetic and control circuit (35) subtracts the cylindrical power of the distance portion (40) from the cylindrical power of the distortion areas (42, 43). Based on the obtained subtraction results, the arithmetic and control circuit (35) computes boundary lines (44, 45) between the distance, progressive, and near portions (40, 41, 41') and the distortion areas (42, 43) except these portions, and allows the display unit (3) to display the boundary lines (44, 45).