Johnson & Johnson Vision Products Inc.

Johnson and Johnson Vision Care, Inc.

Robert B Phillips

Victor Lust

Kornelis Renkema

Edgar V Menezes

Wallace Anthony Martin

Scott Frederick Ansell

Wybren Van Der Meulen

Jongliang Wu

Carl Crowe

Gerbrand Eshuis

Jeffrey H Roffman

Craig William Walker

Timothy A Clutterbuck

Stephen C Pegram

Gregory L Berckmiller

Michael William Litwin

Gerald Robert Krebsbach

Timothy P Freeman

Richard J Fox

Jong Liang Wu

Thomas R Daniels

Sanjay Rastogi

Richard F Barbas

This invention provides a method and a mold for improving the release of a molded ophthalmic device from a mold. The method comprises the steps of: providing a first mold half and second mold half each having opposing top surfaces at least one of which has been hollowed out to define a cavity for forming said ophthalmic device and at least said first mold half further defining a boundary for a release element, said boundary is part of said cavity, said release element comprising a ramped surface, said cavity having a corresponding ramped surface, and said release element having its widest part near the top surface of said at least said first mold half that defines said release element therein. The mold of this invention has a hollowed-out portion as part of the cavity to provide a release element to the molded ophthalmic device.

Method and mold for making ophthalmic devices

Designs for basecurves are disclosed which are designed to promote adhesion of an excess polymer HEMA ring to the basecurve during a demolding operation such that the excess polymer HEMA ring is removed along with the basecurve during the demolding operation. The basecurve mold designs promote and maintain adhesion of an excess polymer HEMA ring to the basecurve in a process for molding cast contact lenses in mold assemblies, each comprising a frontcurve and a spaced basecurve, and wherein a molded lens is formed therebetween. In an embodiment of the invention, the annular area of the basecurve mold can be formed with an annular step which includes projecting teeth positioned therearound which project into the excess polymer HEMA ring.

Basecurve mold designs to maintain HEMA ring/basecurve adhesion

A method of manufacturing complex optical surfaces in soft contact lenses includes a first step of defining the complex optical surfaces with a computer assisted drafting program using a mix of patient determined parameters and selected manufacturing process determined parameters to define a mathematical 'meta lens'. A machine code data set is then generated to machine a plurality of contact lens mold inserts to define a complex optical surface on each of the inserts. The machining step is conducted with a single point diamond lathe having submicron precision and repeatability. A first and second plurality of intermediate contact lens mold halves are then molded with said contact lens mold inserts to define said complex optical surfaces on said mold halves having micron range transitions between optical surfaces. The complex geometric forms and optical surfaces include bifocal lenses, aspheric lenses, and toric lenses wherein the lenses may include parabolic or elliptical geometry. The first plurality of mold halves is assembled with the second plurality of mold halves with a polymerizable monomer therebetween and polymerized to form a plurality of soft contact lenses having said complex optical surfaces defined thereon.

Method of manufacturing complex optical designs in soft contact lenses

An on-demand fast cycle mold for producing injection molded products such as polypropylene blister package bases. The on-demand fast cycle mold has a heated and cooled hot runner system which provides a short response time and optimal temperature control. On-demand injection molding is made possible by a pulse modulated closed loop mold cooling system, the cooling design of brazed gate inserts, and an effective layout of the cooling channels. The programming of the software for a computer control system has also been designed to achieve on-demand injection molding. The design of the closed loop mold cooling system incorporates an advanced cooling circuit layout, and provides for easy maintenance and better quality control of the coolant which significantly reduces corrosion and scale buildup. Mold cooling is controlled by sensors installed inside the mold which are used in feedback control loops. The brazed gate inserts provide precise mold temperature control and improved cosmetic appearance of the molded packages. The use of a needle-valve injection nozzle results in reduced cycle time and improved moldability.

On-demand fast cycle mold

An apparatus for molding polystyrene mold halves which are used, for subsequent molding of a soft contact lens. The apparatus is designed with superior heat conduction capacity so as to minimize the molding cycle time, while simultaneously producing uniformly precise and accurate optical quality surfaces. Molten polystyrene is provided via a hot runner system to a plurality of mold cavities. In a specific variation, the convex surface provides the optical quality surface to the concave surface of the mold half produced thereby. The structural element which defines the convex surface includes a hollow cylindrical bushing and a removable power insert mounted therein, which may be changed so that the prescription strength of the contact lens to be formed by the mold may be varied. In a first embodiment, the power insert includes only a convex surface at its operational end. In a second embodiment, the power insert includes an annular flat surface surrounding the convex surface, defining at the junction therebetween a discontinuity of curvature, which imparts a sharp edge to the mold half formed thereby. The power insert may be constructed of pure steel, or alternatively, it may be made of brass, copper chromium, or cobalt-nickel alloyed martensitic steel. The power insert may be coated with a surface layer of nickel phosphor or silicone oxide, or chrome nitride. These layers may be turned to their proper thicknesses and dimensions by diamond cutters, and they may be thermally hardened.

Molding arrangement to achieve short mold cycle time

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Orange Park, FL, United States of America

Robert B Phillips