Abstract:
A process for continuously preparing lenses excellent in various optical properties which are free from variation over the whole lenses, and lenses prepared by the method. The first step of forming a thiourethane prepolymer and the second step of reacting the thiourethane prepolymer with at least one urethane forming monomer are carried out in an extruder or a reactor provided in a later step with an extruder. The extruded optical thermoplastic thiourethane-urethane copolymer is spread into a sheet and stamped out to form a lens precursor, which is then pressed so that a predetermined curved surface is imparted to at least one side of the lens precursor.
Abstract:
There is provided a method for continuously manufacturing an optical article which comprises a first step of thermal press-molding a sheet-like curved body and a second step of insert injection-molding a back resin on a concave side of the sheet-like curved body, while transferring the continuous sheet in a longitudinal direction, using an apparatus for manufacturing an optical article in which a press-molding machine which can thermal press-mold the sheet-like curved body and an insert injection-molding machine equipped with a mold having a curvature similar to that of the sheet-like curved body are serially positioned in this order, wherein a cycle of thermal press-molding and a cycle of insert injection-molding are synchronized to continuously insert-mold the back resin on a concave side of the sheet-like curved body while continuously thermal press-molding the sheet-like curved body.
Abstract:
A system and method for treating the surface of an optical lens is provided. A predetermined pressure and a plasma gas are maintained in a coating chamber. A plasma cloud of gas is established between electrodes in the chamber. An entry chamber is upstream from the coating chamber, and an exit chamber is disposed downstream from the chamber. A lens is moved into the entry chamber, and at least a portion of the entry chamber adjacent to the coating chamber is brought to the predetermined pressure. Process gas is introduced into this area. The entry chamber is then brought into communication with the coating chamber, and the lens is moved into the coating chamber and through the cloud. Process gas is introduced into at least a portion of the exit chamber adjacent the coating chamber, and this portion is brought to the predetermined pressure. The lens is then moved from the coating chamber to the exit chamber.
Abstract:
A lens molding method and system which uses glass molds (204, 206) held by floating cannisters (200, 202) with a cylindrical dam (210) to define the edge of a molding cavity (99) into which a preheated lens blank is inserted. Once between the molds (204, 206), the lens blank is additionally surface heated, molded and cooled under pressure.
Abstract:
Suivant l'invention, on assemble un moule (13) comportant deux coquilles de moulage (14A) et un élément de fermeture (12) qui, établi annulairement autour de ces coquilles de moulage (14A), définit avec celles-ci la cavité de moulage requise, les coquilles de moulage (14A) étant disposées de chant, et une ouverture de coulée étant ménagée dans l'élément de fermeture (12) à la partie basse de la cavité de moulage pour l'introduction de la matière à mouler dans cette cavité, on remplit le moule de la matière à mouler nécessaire, et on présente directement au droit de l'une (14A) des coquilles de moulage (14A) la source de rayonnement (33) nécessaire pour que l'initialisation, au moins, de la polymérisation de la matière moulée se fasse par insolation globale. Application, notamment, à la réalisation des lentilles ophtalmiques.
Abstract:
A method wherein (a) a polymerisable composition (8) consisting of transparent organic glass is fed into a mould; (b) the composition is polymerised under such conditions that the resulting transparent organic glass substrate has at least one thin surface layer (10) polymerised with a degree of completion and/or cross-linking that is substantially lower than in the rest (9) of the substrate; and optionally (c) subjecting the substrate to thermal stress relief annealing. The method is useful for producing finished or semi-finished ophthalmic articles, particularly photochromic ophthalmic articles.
Abstract:
A method of manufacturing plastic lenses from a urethane resin or the like, which have no or little optical strain by cast polymerization. In this casting process, polymerization is effected while a proper motion, for example, a particular rotating motion, rotating motion with the axis of rotation substantially horizontal, and the like is imparted to a shell so that the gravity acting on any minute portion comprising the monomer injected into the shell continuously changes its direction.
Abstract:
Il s'agit d'assurer le remplissage d'un moule (10) qui, destiné à l'obtention d'une lentille optique, est formé de deux coquilles de moulage (11A, 11B) disposées de chant et à la périphérie desquelles est établi annulairement un element de fermeture (12) définissant avec elles la cavité de moulage (13) recherchée, avec, pour l'introduction de la matière à mouler (18) dans cette cavité de moulage (13), une ouverture de coulée ménagée à cet effet dans l'élément de fermeture (12). Suivant l'invention, on dispose l'ouverture de coulée à la partie basse de la cavité de moulage (13). Application, notamment, à l'obtention de lentilles ophtalmiques.
Abstract:
Method, apparatus and composition for making and coating a plastic lens. The method includes disposing a liquid composition and a photosensitive initiator into a mold cavity and directing ultraviolet light to act on the lens forming material in the cavity to produce a lens therefrom. An improved postcure process and scratch resistant coating process is disclosed.