Patent ID: 7646475

Claim:
A measurement device for automatically measuring characteristics of an ophthalmic lens (L 1 ), the device comprising: a lens support ( 2 ) arranged to receive the lens; on a first side of the lens support, lighting means ( 208 ) including an optical system for generating a light beam directed towards the ophthalmic lens installed on said support; and on a second side of the lens support, analysis means ( 210 ) for analyzing the image transmitted by said ophthalmic lens installed on said lens support and illuminated by the lighting means ( 208 ); and light beam separator means comprising: a first mask ( 220 ) forming a Hartmann matrix and disposed on the first side of the lens support to be illuminated by said light beam upstream from the lens; at least one second mask ( 240 ) forming a Hartmann matrix disposed on the second side of the lens support to be illuminated by said light beam, the masks ( 220 , 240 ) being at least partially disengageable; and an electronic and computer control unit which is suitable for: causing the measurement device to adopt at least three states, including a first state in which said first mask ( 220 ) is the only mask to be engaged, a second state in which the second mask ( 240 ) is the only mask to be engaged, and a third state in which all the masks ( 220 , 240 ) are disengaged simultaneously, and correcting read error when the measurement device is in the first state, performing an overall analysis of one or more optical characteristics at a plurality of points over the entire extent of the lens when the measurement deice is in the second state, and determining printed marks, etched in relief, and segments when the measurement device is in the third state.