Abstract: A device is used which comprises a transparent support positioned between illumination means and a camera. A frame axis is formed on a demonstration lens, for which the convex face is laid on the support. The contour (34) and the frame axis (10I) are captured, and the barycenter (B) of said contour is determined in order to place a machining adapter therein. Application to the grinding of ophthalmic lenses.

Abstract: A device is used which comprises a transparent support positioned between illumination means and a camera. A frame axis is formed on a demonstration lens, for which the convex face is laid on the support. The contour (34) and the frame axis (10I) are captured, and the barycenter (B) of said contour is determined in order to place a machining adapter therein. Application to the grinding of ophthalmic lenses.

Abstract: The system including a device (2) for applying an adapter (11) to a blank (1) for transferring it into and mounting it in a trimming device (3) controlled in accordance with trimming information. The system includes a device for acquiring the characteristics of a lens to be made, a device (10) for supporting the blank (1) in the device (2) for applying the adapter, devices (14, 15) for emitting/receiving radiation for analyzing the blank a device (4, 16) for acquiring the characteristics of the blank by analyzing a signal delivered by the emitting/receiving devices (14, 15) and a device (4) for determining blank trimming information for controlling the trimming device (3).

Abstract: A diamond-charged abrasive layer (3) of a grinding wheel has a convex profile over at least part of its length (L) in order to have greater resistance to wear. Also provided is a machine for grinding ophthalmic lenses which employs the grinding wheel.

Abstract: A frame holder has two jaws (1, 2) mounted so as to be slidable relative to each other in order to be movable toward or away from each other. A clamping mechanism (5) is provided for maintaining the frame (6) between the jaws in a reference plane. At least one jaw (1, 2) is provided with at least one sensor (14) which is adapted to produce a signal indicating the arrival of the jaw in a position of activation of the clamping mechanism (5) when the two jaws move toward each other. The frame holder can be used in an apparatus for analyzing rims of spectacles frames.

Abstract: This machine comprises a train of grinding wheels (T) which is keyed on a shaft (2), and a blank-holding assembly (5, 7) designed to bring the blank (8) into contact with the grinding wheels. The said machine comprises, furthermore, an additional grinding wheel (9) mounted freely rotatably on a support (10), means (11) for actuating the support, which are designed to displace the additional grinding wheel (9) between a retracted position and an active position in which its axis of rotation (Y--Y) is parallel to the axis of the said shaft and in which the additional grinding wheel is in driving contact with a drive disc (17) integral with the train of grinding wheels, and means for bringing the blank into contact with the additional grinding wheel (9) when the latter is in the active position. The invention is used for the counter-bevelling and/or grooving and/or drilling of optical glasses.