Abstract:
PROBLEM TO BE SOLVED: To provide a method for reading the three-dimensional shape of a profile such as the bezel of a spectacle frame rim. SOLUTION: The optical non-contact method for reading the three-dimensional shape of a profile in accordance with the luminous suction principle includes scanning the profile with a plane light beam intersecting the profile transversely, simultaneously reading the trace of the plane light beam on the profile by means of an optical receiver having an optical pointing axis at a constant non-zero pointing angle to the light beam at a series of positions along the profile, and deducing the three-dimensional shape of the profile from the readings performed at these various positions. On each reading, the light beam of which the trace on the profile is read by the optical receiver is chosen from a plurality of predefined light beams which can be activated alternately. The non-contact optical reading method is particularly suitable for reading the three- dimensional shape of the inside edge of a spectacle frame rim, known as the bezel. A specific device is used to implement the method in this application.
Abstract:
PROBLEM TO BE SOLVED: To provide a method for determining the orbits of grooves formed by machining at the edges of lenses to be mounted at a spectacle frame of a 'metal supra' type. SOLUTION: The lenses 20 are adapted to be fitted to rims or frames 11 of the spectacle frame 10. The respective rims or frames 11 have rigid portions 12 and filaments 13 extending from the one-side ends (E1) of the rigid portions 12 to the other ends (E2) thereof. If the lenses are formed in the manner described above, the curvature of the rigid portions 12 may be systematically taken into consideration with respect to the portions (T1) of the required orbits of the grooves corresponding to the rigid portions 12 in question of the spectacle frame 10.
Abstract:
The invention concerns a device comprising in combination: means for detecting (4) characteristics of a lens; means for integrating characteristics representing a patient's morphology; a support (3) of the mobile lens along a predetermined trajectory between a first measuring position and a loading position; grinding means (20); and means forming a gripping and clamping clip (25) for transporting the lens from said loading position to said grinding position.
Abstract:
The lens clamp comprises drive stop(s) (16a, 16b), each with a relatively non-deformable center (24a, 24b) surrounded by an outer collar (26a, 26b) of a semi-rigid and elastically deformable material bending to the shape of the lens (20). The collar is 1.5 mm thick and has a surface (28a, 28b) covered with a 1 - 2 mm layer (30) of a plastic or elastomer material making contact with the lens.
Abstract:
During the chamfering of the edge (6) of the lens, the edge is scanned by a plane light beam (23) which forms a linear light mark (24). An image of the light mark is formed in an optical reception system (26). This image is used to monitor and control the machining process. The procedure provides chamfering for the edge (6) of a an ophthalmic lens (1), during which the edges of the lens are removed successively in order to define the chamfered edge (6). During this process, the edge (6) of the lens is scanned by a plane light beam (23) which forms a linear light mark (24). At the same time an image of the light mark is formed in an optical reception system (26). From this it is possible to deduce the successive positions of the image, and hence the position of the chamfer formed on the edge of the lens. The process is carried out whilst the lens is mounted to rotate about an axis (A1), whilst its edge is in contact with the chamfering tool. The relative position of the lens and the tool are adjusted as a function of the light mark detection.
Abstract:
The method involves placing a template (2) corresponding to a lens to be obtained, in an axis. The template is placed to contact with a grinding stone (6) on another axis. A relative position of the axis is checked for achieving a discrete or continuous reading of the template. A shape of the template is determined by a calculation and the template is withdrawn. A raw-material is placed and processed. An independent claim is also included for a machine for manufacturing an ophthalmic lens.
Abstract:
The opthalmic lens moulding process has a lens section (4) with a forward face (2) and a rear face. In the lens lifting step the lit face of the lens is swept by a luminous beam (22) whilst simultaneously raising on the optical receiver (24) the successive image points following the task settings (23) thus finding the lifting effect on the three dimensional edges.
Abstract:
The template is mounted in the place of the ophthalmic lens on the grinder to be calibrated. It has the general shape of a disc being circular on a part of its periphery (22). There are locally two sharp points (23), circumscribed by the same circumference (C), which are angularly separated from each other by 90 degrees . In the smallest (A'1) of the two subtended angles at the centre (A'1,A'2) delimited by the sharp points the disc contour is concave. The circumference which circumscribes the two sharp points on its periphery then extends into its circular part (22A). The two sharp points result from the intersection of the disc circular part with a notch (22B) cut into its periphery.