Method for trimming an opthalmic lens

摘要

A method for trimming an ophthalmic lens using a machining device having a load sensor for measuring a load relating to the load applied by a machine tool to the lens, includes: immobilizing the lens on an immobilizing element, and trimming the lens, while measuring the load magnitude and steering the machine tool relative to the immobilizing element so as to bring the initial contour of the ophthalmic lens to a final contour of a different shape. Between the immobilizing and trimming steps, the machine tool is steered relative to the immobilizing element so that it makes a tour around the lens without contact therewith, while measuring the unladen load magnitude, this relating to the load required to move the machine tool relative to the immobilizing element without performing machining work while steering the machine tool, during the trimming step, as a function of the unladen magnitude measured.

主权项

1. A process for shaping an ophthalmic lens using a machining device equipped with clamping means for clamping the ophthalmic lens, a machining tool for machining the ophthalmic lens and a force sensor adapted to measure a force that is related to the force applied by the machining tool to the ophthalmic lens, comprising:
a step of clamping the ophthalmic lens in said clamping means; and a step of shaping the ophthalmic lens using said machining tool, in which step the loaded value of said force is measured and said machining tool is controlled, relative to said clamping means, depending on the measured loaded value, so as to bring the initial outline of the ophthalmic lens to a final outline of different shape, wherein said process comprises, between said clamping step and said shaping step, at least one intermediate step in which said machining tool is controlled, relative to said clamping means, so as to travel the circumference of said ophthalmic lens, without contact, following a path deduced from said initial outline, and in which the unloaded value of said force measured by the force sensor is recorded, which value is related to the forces required to move said machining tool in free space relative to said clamping means, considering the frictional and inertial forces at work; and wherein, in the shaping step, said machining tool is controlled depending on the recorded unloaded value.