Abstract: The disclosed embodiments include a system, apparatus and method for forming an ophthalmic lens having reduced risk of optical defects. An illustrative injection molding system includes a heated sprue and a hot runner fluidly coupled to the heated sprue. The system also includes a mold fluidly coupled to the heated runner to receive a molten material. The mold includes a material conduit, which may be included in an interchangeable gate insert, and a lens cavity. The hot runner forms a material conduit having an inlet for receiving material from the hot runner and an outlet for delivering material to the lens cavity. The material conduit also includes a branch cavity disposed between the inlet and the outlet for receiving a diverted volume of degraded lens material.

Abstract: An apparatus and method for producing defect-critical articles from a molding resin comprising at least 98% clear polymer and additives including a heat stabilizer and a UV blocker in an injection molding machine. According to the apparatus, there is provided an injection molding machine in combination with a molding resin. The injection molding machine's resin delivery assembly is made from a powder metallurgy formed into solid non-coated parts having a Chromium-Vanadium (Cr/V) blend. As the molding resin interacts with the resin delivery assembly, the resin only contacts the solid non-coated parts whereby the resin experiences less degradation and provides improved quality for the defect-critical articles. The method includes the steps of plasticizing, injecting, and cooling. During the plasticizing and injecting steps, the molding resin only contacts solid non-coated parts made from a powder metallurgy material containing a Chromium-Vanadium (Cr/V) blend thereby producing reduced defect articles.

Abstract: A method and system for monitoring lens material residence within a conduit to improve the quality of molded products by reducing defects arising from entrapped lens material. According to the method a finite element mesh representative of a conduit is stored in a digital storage device. A simulation is run on a digital computer in which one type of lens material sequentially flows through the conduit in discrete batches temporal history of the batches within the conduit is tracked. The simulation is useful for analyzing material delivery conduits in injection molding and casting systems, for example, for lens manufacturing. According to the system, a digital storage device stores a finite element mesh representative of a conduit. A digital computer is coupled to the digital storage device for executing a set of instructions to run a simulation and track the temporal history of the batches within the conduit.

Abstract: An apparatus for wetting and coating ophthalmic lenses having a tank with a cleaning or coating solution and a handling system for sequentially moving a lens and the solution in relation to each other, to wet the lens. A master control module is coupled to the handling system and configured execution a wetting profile. The wetting profile moves the lens to obtain a generally consistent lens surface wetting speed so that the lens coating has a more uniform thickness. According to a method, lenses are wetted in a liquid bath. The lens is placed in a handling system which moves the lens with respect to the bath according to a wetting profile. The wetting profile is based on the incremental vertical lens surface slope with respect to the surface of the solution.

Abstract: A walk-up, user accessible cleaning workstation having a sensor and ionization nozzle arranged on a frame. The frame mounts the sensor in a fixed position to the nozzle in operative proximity to a cleaning area. The frame partially encloses the nozzle's electrode. The sensor detects manual workpiece placement into the cleaning area to open the gas valve and activate the power supply. The panel deflects dust flying off the workpiece from reaching the user's face. The workstation improves safety in the cleaning and destaticizing of ophthalmic lenses.

Abstract: Optical qualities of a production lot of base material used in the fabrication of semi-finished lenses may be accurately determined by employing chipper plate samples produced from the base material in accordance with aspects of the present invention. In various implementations of the present invention, the chipper plates samples may be fabricated by subjecting base material to an extended cycle time and temperature profile using a mold having cavities of different thicknesses. The resulting chipper plates provide an improved indication of the color of semi-finished lenses molded from the production lot as well as an improved indication of resin stabilizer defects that may be utilized during a pelletizing process to control and enhance the quality of a production lot. Furthermore, the chipper plates may be provided by suppliers as samples of a production lot to enable customers to base purchasing decisions on a reliable and accurate measure of optical properties.

Abstract: A hardware configuration and related method for performing a coining-type injection compression operation. The invention is useful in molding lenses since lenses have different thicknesses at various points. The equipment maintains the mold in a closed position during the entire molding cycle. A two part standoff post is designed to provide for slight axial compression during high injection pressure. The standoff post also provides a convenient mounting surface near the parting line to install inserts at various heights.

Abstract: A method and apparatus for improving the performance of rimless spectacle lenses. An abrasive wire is provided for polishing bore holes which are drilled in lenses. The abrasive wire includes a wire substrate with abrasive particles embedded along its length. The wire and particles are dimensioned for threading through the bore hole and allowing space to perform a soft-filing operation. By polishing the micro cracks formed during drilling, propagation leading to lens failure which arises from spectacle use can be reduced.

Abstract: A hardware configuration and related method for straight injection molding of ophthalmic lenses using thermal control fluid circulating within a closed channel located interior of the insert. The channel is closed by a no-leak valve. The adjusting body is equipped with a mating no leak valve. The valves seal over an operational distance L before the valves are opened to admit the thermal circulating fluid into the insert. The insert can be easily changed or shimmed without leaking and without having to change the insert configuration.

Abstract: A method of infusing a dye into the surface of an article formed of a plastic material comprises contacting the surface with a solution including one or more solvents each aggressive to the plastic material, one or more dyes and one or more substances each capable of plasticizing the plastic material. If the plastic material is polycarbonate, then the aggressive solvent may be one or more chlorinated hydrocarbons. The dye may be a photochromic dye, a cosmetic tinting dye, dyes for absorbing infrared, laser and ultraviolet radiation, or combinations thereof. A wide range of plasticizers has been investigated. The article is contacted by the solution for ten seconds to one minute; and nearly all the infused solvent is then evaporated from the article by heating. The use of one or more plasticizers reduces or eliminates bubbling or hazing of the contacted surface during solvent evaporation.

Abstract: A method of making photochromic thermoplastic wherein the material is extruded into a length or lengths having at least one relatively small cross-sectional dimension. The length or lengths are treated with a solution of photochromic dye dissolved in a solvent, for example, cyclohexanone, which attacks the material. The length or lengths have a surface area-to-volume ratio sufficiently large to absorb an effective amount of the dye at their surface or surfaces. The length or lengths are dried to evaporate the solvent. The length or lengths are heated during the treating and drying steps. The dried length or lengths are cut into smaller pieces which may be introduced directly into a molding machine to form photochromic articles. Where a plurality of lengths are provided, the surfaces thereof are maintained separated from one another during the treating and drying steps.

Abstract: A method of building up an oxidized metal coating on a substrate in which the substrate is positioned adjacent a metal target in a chamber containing a low pressure mixture of inert and reactive gases; and a voltage having AC and DC components is applied to the target to sputter onto the substrate a thin layer of elemental metal and oxidized metal. The substrate is then moved to an oxidizing station in the chamber and the layer is subjected to reactive ions, as for example a beam of reactive ions, which oxidizes the elemental metal in the layer. The steps are repeated until an oxidized metal coating of a desired thickness has been built up.

Abstract: A sunglass or eye protector molded from suitable optical material with inner and outer surfaces, both of which are noncircular in the horizontal direction and curved in the vertical meridian to provide substantially uniform thickness throughout.

Abstract: A surface of an article, such as an optical element, formed of a polycarbonate-polyester copolymer, is subsequently tinted to a predetermined degree by first subjecting said surface to ultraviolet radiation of predetermined intensity for a predetermined period of time.

Abstract: A method of making a concave aspheric mold insert by electroplating nickel over a silver release agent coating on an aspheric surface formed in a copper substrate to form a master having a convex surface which is a negative image of the aspheric surface. After the master has been separated from the substrate its convex surface is coated with a silver release agent and electroplated with nickel to form an element having a concave surface which is a replication of the aspheric surface and the opposite surface of which is convex. After the convex surface of the element has been trued to spherical shape, a slightly oversize spherical D-seg is formed in the aspheric surface. The aspheric surface is then trued to reduce the D-seg to final size to produce the insert. A number of elements are formed from the master and are provided with D-segs of different radii.

Abstract: An insert for molding the convex surface of a progressive lens, the insert having an annular shoulder or flat disposed to the rear of the front edge of the concave surface of the insert. The periphery of the insert includes a first cylindrical surface axially extending rearwardly from the front surface of the insert and a second cylindrical surface of larger diameter axially extending forwardly from the rear surface of the insert. The two cylindrical surfaces are joined by the radially extending shoulder. A retainer for the insert is provided with two axially displaced bores of respective diameters slightly greater than those of the two cylindrical surfaces of the insert. Positioned between the bores is a radially extending annular shoulder or flat.

Abstract: A progressive addition lens constructed on the bipolar principle in accordance with a power law having a steeper slope or gradient in the regions adjacent to the poles than in the middle region thereof between the poles.

Abstract: A progressive power lens series in which the surface of each lens body has first and second vision portions which differ in power in accordance with a power curve which lies entirely in the y-z plane of a Cartesian coordinate system and which is the umbilical portion of the principal meridian of the progressive surface with the curvature of the surface in at least one of said vision portions spreading away from the power curve in accordance with a spreading function defined by the intersection of nested non-bipolar conic sections or nested hyperbolic cosines with the x-y plane of the coordinate system.