Patent ID: 6061123
Filing Date: 2000-05-09
Classification: G01M

Abstract:
A lens meter comprising:an illumination optical system for projecting a measurement light beam onto a lens to be inspected;a light receiving optical system having a photosensor that detects the measurement light beam which has passed through the lens, the photosensor outputting a photosensor detection result;a display unit for displaying refractive characteristics from said photosensor detection result; andarithmetic control means in which cylindrical refractive characteristic values of a distance portion of the lens are calculated based on the cylindrical power and a direction of a cylindrical axis, the cylindrical power and the direction of a cylindrical axis being transmitted to the arithmetic control means via said photosensor detection result, cylindrical refractive characteristic values in distortion areas except the distance portion, a progressive portion contiguous to the distance portion, and a near portion of the lens then being calculated based on the cylindrical power and the direction of the cylindrical axis, boundary lines between the distance, progressive, and near portions and the distortion areas except the distance, progressive, and near portions are then calculated from each obtained cylindrical refractive characteristic value of the distance portion, and said display unit is allowed to display the boundary lines.