Method and device for producing ophthalmic lenses and other shaped bodies with optically active surfaces
First Claim
1. Method for producing ophthalmic lenses and other shaped bodies having optically active surfaces according to a general or individual prescription, including the use of plastic blanks in the form of flat, round discs of any surface geometry and including the application of manufacturing techniques with mechanical material removal (milling, turning, grinding, smoothing, polishing, etc), characterised in that the plastic blanks (1) used are clamped (externally or internally) at their outer edge and the desired final surface geometry and surface quality of the convex front face (19) and concave rear face (27) of the lens are produced by machining using milling and/or lathe tools as well as by smoothing and, if applicable, polishing, with an annular region (30) of larger thickness (33) being retained at the outer circumference of the workpiece (16), and the annular region (30) serving to clamp or to handle the workpiece (16) during all processing and transport operations, and also with the annular region (30) supporting and mechanically stabilising the actual ophthalmic lens (32) or shaped body for further processing, in that markings and/or shapes are applied to the annular region (30) which serve for the identification of the processing axes, and in that very fine markings are applied to the surface of the actual ophthalmic lens (32) or shaped body which serve to characterise the axial position of the surface geometries produced, and that subsequently the ophthalmic lens (32) is separated from the annular region (30).
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Accused Products
Abstract
The invention concerns a method for producing ophthalmic lenses that uses plastic blanks in the form of flat, round discs. The outer edge of said plastic blanks is clamped and the desired final surface geometry and surface quality of the front faces of the lens are subsequently produced by a machining process using grinders and/or lathes and by smoothing and polishing processes. During machining, a thicker annular region is retained on the outer circumference of the workpiece. The annular region clamps or arranges the workpiece during machining and transport operations and stabilizes the lens for additional machining. Shaped pieces for identifying the machining axes are attached to the annular region. The lens is provided with fine markings to characterize the lens that has been produced, with the lens then being separated from the region.
23 Citations
38 Claims
- 1. Method for producing ophthalmic lenses and other shaped bodies having optically active surfaces according to a general or individual prescription, including the use of plastic blanks in the form of flat, round discs of any surface geometry and including the application of manufacturing techniques with mechanical material removal (milling, turning, grinding, smoothing, polishing, etc), characterised in that the plastic blanks (1) used are clamped (externally or internally) at their outer edge and the desired final surface geometry and surface quality of the convex front face (19) and concave rear face (27) of the lens are produced by machining using milling and/or lathe tools as well as by smoothing and, if applicable, polishing, with an annular region (30) of larger thickness (33) being retained at the outer circumference of the workpiece (16), and the annular region (30) serving to clamp or to handle the workpiece (16) during all processing and transport operations, and also with the annular region (30) supporting and mechanically stabilising the actual ophthalmic lens (32) or shaped body for further processing, in that markings and/or shapes are applied to the annular region (30) which serve for the identification of the processing axes, and in that very fine markings are applied to the surface of the actual ophthalmic lens (32) or shaped body which serve to characterise the axial position of the surface geometries produced, and that subsequently the ophthalmic lens (32) is separated from the annular region (30).
- 17. Device for producing ophthalmic lenses and other shaped bodies having optically active surfaces according to a general or individual prescription comprising processing machines having two rotatorily driven, translatorily moveable spindles, with the rotary and translational movements being controlled and connected in a control system of the machine and clamping and processing tools being connected with the spindles, characterised in that the processing machine comprises a tool spindle (20) adapted to perform phase and speed controlled rotary movements around a B axis and controlled translational movements along Y and X axes (feed movements), whereas a workpiece spindle (21) with the clamping tools (2) and (18) is adapted to perform phase and speed controlled rotary movements and highly dynamic translatory movements along the Z axis (advance movements).
- 22. Method for producing ophthalmic lenses and other shaped bodies having optically active surfaces according to a general or individual prescription, including the use of semi-finished parts produced by chipless forming processes such as casting, injection moulding or compression moulding by means of moulds and dies, followed by mechanical manufacturing steps such as milling, turning, grinding and polishing, characterised in that plastic blanks (41) are produced by chipless forming processes, with the concave rear face (42) of the lens as optically active surface as well as a shaped edge (43) being formed integral with said plastic blanks (41), in that the semi-finished parts (41) are then clamped by means of their shaped edge (43) into processing machines where the desired surface geometry and quality of the front lens face (45) are produced by machining and smoothing as well as polishing, if applicable, with the shaped edge (43) being retained and serving for clamping and arranging the workpiece (49) and also for supporting and mechanically stabilising the actual ophthalmic lens (47) or shaped body for further processing, and in that the ophthalmic lens (47) or shaped body is separated from the shaped edge (43) at the end of processing.
- 28. Method for producing ophthalmic lenses and other optical shaped bodies, including the use of semi-finished parts produced by chipless forming processes such as casting, injection moulding or compression moulding by means of moulds or dies, followed by mechanical manufacturing steps such as milling, turning, grinding and polishing, characterised in that plastic blanks (41) are produced by chipless forming processes, with the convex front face (45) of the lens as optically active surface as well as a shaped edge (43) being formed integral with said plastic blanks (41), in that the semi-finished parts (41) are then clamped by means of their shaped edge (43) into processing machines where the desired surface geometry and quality of the concave rear lens face (46) are produced by machining and smoothing and by polishing, if applicable, with the shaped edge (43) being retained and serving for clamping and arranging the workpiece (49) in all further processing and transport operations and also for supporting and mechanically stabilising the actual ophthalmic lens (47) or shaped body for further processing, and in that the ophthalmic lens (47) or shaped body is separated from the peripheral area with the corresponding shaped edge (43) at the end of the processing.
- 34. Device for producing ophthalmic lenses and other shaped bodies having optically active surfaces according to a general or individual prescription comprising a mould which is composed of a front mould part, a rear mould part and a sealing ring, said three components being connected with one another in a removable and sealing manner, characterised in that the rear mould part (56) comprises a shoulder (60) and that the rear mould part (56) has a shaped face (18) adapted to generate optically active surfaces, and in that the front mould part (54) has a shaped face (59) not suited to generate optically active surfaces.
Specification