Patents by Inventor Amitava Gupta
Amitava Gupta has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 5907386Abstract: A progressive optic has an optical preform wherein the radius of curvature of the surface is altered by forming discrete spherical portions across the surface. A thin intermediate layer, having a different refractive index from the optical preform, is then cast over the formed optical preform surface. The optical preform having the thin intermediate layer is then cast with a resin superstrate layer which restores the curve of the optic. Each spherical section, defined by the spherical portions and corresponding portions of the outer surface of the superstrate layer, alters the spherical power of the adjacent spherical section by about 0.03 D to 0.05 D.Type: GrantFiled: October 17, 1997Date of Patent: May 25, 1999Assignee: Innotech, Inc.Inventors: Amitava Gupta, Ronald D. Blum
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Patent number: 5888122Abstract: A method of manufacturing an intraocular lens for restoring visual function to an eye. The lens includes a convex lens optic for receiving and focusing light rays, a prismatic wedge adjacent to the convex lens optic for receiving and directing light rays to a functional portion of a retina of the eye, and structure for fixing the lens optic and the prismatic wedge in the eye so that the lens optic is angularly oriented with respect to an optic axis of the eye and is posterior to the prismatic wedge. The lens optic includes an aspheric surface having a geometry determined according to a specific formula.Type: GrantFiled: April 10, 1997Date of Patent: March 30, 1999Assignee: Prism Ophthalmics, L.L.C.Inventors: Amitava Gupta, Jose Ulloa
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Patent number: 5872613Abstract: A method for providing a contact lens for a patient. According to this method, an optical preform is selected, and a resting position of the optical preform on the patient's eye is determined. An optical feature is also located on a patient's eye. Then, a reference position is located on the surface of the optical preform coincident with the optical feature on the patients eye, when the optical preform is in the resting position. Finally, the optical modification is provided on the optical preform at a location based on the reference position on the optical preform, either by machining the preform itself or by machining a mold that is subsequently used to form the lens.Type: GrantFiled: June 13, 1996Date of Patent: February 16, 1999Assignee: Innotech, Inc.Inventors: Ronald D. Blum, Amitava Gupta
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Patent number: 5861934Abstract: An optical product such as an optical lens, or semi-finished lens blank is provided comprising a composite of at least three different and separately applied layers, each layer having a different refractive index which allow for a progressive multifocal lens having a wide and natural progression of vision when looking from far to near. In addition, a method is provided for simply, quickly and inexpensively manufacturing a composite refractive gradient progressive multifocal lens. A transition zone disposed between a base and an outer layer includes a distinct and separately applied transition layer or layers having an effective refractive index which is intermediate between the refractive indices of the base and outer layers, and preferably approximates the geometric mean of the refractive indices of the base and outer layers. This transition zone may include multiple transition layers, with each transition layer having a different and distinct refractive index.Type: GrantFiled: May 6, 1996Date of Patent: January 19, 1999Assignee: Innotech, Inc.Inventors: Ronald D. Blum, Amitava Gupta
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Patent number: 5859685Abstract: A compound ophthalmic lens having improved chromatic aberration is provided which includes a polymerized resin superstrate lens formed on a substrate lens. The chromatic dispersion characteristics of the resin, as well as its refractive index, are matched to the substrate lens to obtain the desired Abbe number, lens power and thickness of the finished lens, and to render the interface between the substrate lens and the superstrate lens substantially invisible. The color dispersion of the substrate lens is compensated for by the superstrate lens which has a relatively low Abbe number and has an opposite power from the substrate lens.Type: GrantFiled: July 18, 1996Date of Patent: January 12, 1999Assignee: Innotech, Inc.Inventors: Amitava Gupta, Ronald D. Blum, Thomas R. Sloan, Venkateshwar Sekharipuram
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Patent number: 5851585Abstract: The present invention relates to new methods of impregnating plastic substrates with photochromic additives. By impregnating the plastic substrate in multiple impregnation steps under varying conditions, the concentration profile of two or more photochromic additive within the plastic substrate can be independently controlled. Methods are also provided for the distribution of a photochromic additive in a high boiling solvent and for increasing the glass transition temperature of a partially cured polymeric resin.Type: GrantFiled: November 14, 1997Date of Patent: December 22, 1998Assignee: Innotech, Inc.Inventors: Amitava Gupta, Ronald D. Blum, Venkatramani S. Iyer
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Patent number: 5847803Abstract: A progressive optic has an optical preform wherein the radius of curvature of the surface is altered by forming discrete spherical portions across the surface. A thin intermediate layer, having a different refractive index from the optical preform, is then cast over the formed optical preform surface. The optical preform having the thin intermediate layer is then cast with a resin superstrate layer which restores the curve of the optic. Each spherical section, defined by the spherical portions and corresponding portions of the outer surface of the superstrate layer, alters the spherical power of the adjacent spherical section by about 0.03 D to 0.Type: GrantFiled: September 17, 1996Date of Patent: December 8, 1998Assignee: Innotech, Inc.Inventors: Amitava Gupta, Ronald D. Blum
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Patent number: 5805266Abstract: A method for providing a contact lens for a patient. According to this method, an optical preform is selected, and a resting position of the optical preform on the patient's eye is determined. An optical feature is also located on a patient's eye. Then, a reference position is located on the surface of the optical preform coincident with the optical feature on the patients eye, when the optical preform is in the resting position. Finally, the optical modification is machined on the optical preform at a location based on the reference position on the optical preform.Type: GrantFiled: May 20, 1994Date of Patent: September 8, 1998Assignee: Innotech, Inc.Inventors: Amitava Gupta, Ronald D. Blum
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Patent number: 5793465Abstract: An optical preform has a predetermined spherical curve on a concave surface of the optical preform, a predetermined spherical curve on a convex surface of the optical preform and a near add power. A thin resin is applied to the concave surface of the optical preform and molded to form a toric layer by a mold having a toric, convex mold surface. The resin layer is then cured and the mold removed to form a finished ophthalmic lens.Type: GrantFiled: October 8, 1996Date of Patent: August 11, 1998Assignee: Innotech, Inc.Inventors: Amitava Gupta, Ronald D. Blum
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Patent number: 5789015Abstract: The present invention relates to new methods of impregnating plastic substrates with photochromic additives. By impregnating the plastic substrate in multiple impregnation steps under varying conditions, the concentration profile of two or more photochromic additive within the plastic substrate can be independently controlled. Methods are also provided for the distribution of a photochromic additive in a high boiling solvent and for increasing the glass transition temperature of a partially cured polymeric resin.Type: GrantFiled: June 26, 1996Date of Patent: August 4, 1998Assignee: Innotech, Inc.Inventors: Amitava Gupta, Ronald D. Blum, Venkatramani S. Iyer
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Patent number: 5728156Abstract: Prismatic intraocular lenses are disclosed for restoring visual function to an eye having macular degeneration. The lenses each include a convex lens optic for receiving and focusing light rays, a prismatic wedge located posterior to the convex lens optic for receiving and directing light rays to a first portion of a retina of the eye, and means for in situ alteration of the optical characteristics of the intraocular lens to direct light rays to a second functional portion of the retina.Type: GrantFiled: August 6, 1996Date of Patent: March 17, 1998Assignee: Prism Opthalmics, L.L.C.Inventors: Amitava Gupta, Ronald D. Blum
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Patent number: 5702819Abstract: A method for making improved optical quality lenses is described which includes arranging a mold having a molding surface, a curable optical quality resin composition, and a plastic lens preform of optical quality material such that the resin composition is disposed between, and in contact with, the plastic lens preform and the mold; upon curing, the resin composition forms a cured plastic attached portion that is bonded to the plastic lens preform. The resin composition and plastic lens preform are selected such that the attached portion has a higher scratch resistance, a lower chromatic aberration, and/or a higher ease of edging than the lens preform.Type: GrantFiled: May 17, 1996Date of Patent: December 30, 1997Assignee: Innotech, Inc.Inventors: Amitava Gupta, Ronald D. Blum, Venkatramani S. Iyer, Paul J. Nagg
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Patent number: 5683457Abstract: A pair of intraocular lenses for restoring visual function to a patient with central field loss. The pair of intraocular lenses includes a first lens for implantation into a first eye of the patient to provide vision of targets located at a distance greater than five feet from the first eye and a second lens for implantation into a second eye of the patient to provide vision of targets at a distance less than twelve inches from the second eye. The first and second lenses each include a prismatic wedge for shifting retinal images to a functional portion of a retina of each respective first and second eye.Type: GrantFiled: May 9, 1996Date of Patent: November 4, 1997Assignee: Prism Opthalmics, L.L.C.Inventors: Amitava Gupta, Richard Mackool
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Patent number: 5598234Abstract: A method for making a finished aspheric single vision, spherical or aspheric bifocal, multifocal or progressive addition contact lens includes the step of fitting a patient requiring a near correction with a single vision spherical or aspheric contact lens for optimal distance vision and comfortable fit. If desired, the patient is then over-refracted to determine the required near correction to be embodied in the contact lens. A portion of the optic corresponding to the center location of the pupil is marked on the convex side of the optic to form an optical preform. In some instances, the lens may not stabilize on the cornea to a suitable degree. Thus, it is often desirable to stabilize the contact lens, either prior to placing the lens on the patient or after rotation is observed on the cornea of the patent. Observation of rotation on the patient's cornea is enhanced by means of the mark that is used to designate the center of the patient's pupil.Type: GrantFiled: March 23, 1994Date of Patent: January 28, 1997Assignee: Innotech, Inc.Inventors: Ronald D. Blum, Amitava Gupta
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Patent number: 5531940Abstract: Methods for making optical quality plastics lenses with photochromic additives are described. According to a first embodiment of the invention, a casting resin is containing photochromic additives is arranged between a mold and a lens preform and then cured. According to a second embodiment of the invention, a casting resin substantially free of photochromic additives is arranged between a mold and a lens preform and then cured. The resin is then impregnated with photochromic additives. In a third embodiment, a layering resin containing a photochromic additive is provided on the surface of a mold and cured to a gel state. Then, a casting resin that is substantially free of photochromic additives is arranged between the coated mold and a lens preform and cured. According to a fourth embodiment, a casting resin that is substantially free of photochromic additive is provided on the surface of a mold and cured to a gel state.Type: GrantFiled: December 10, 1993Date of Patent: July 2, 1996Assignee: Innotech, Inc.Inventors: Amitava Gupta, Ronald D. Blum
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Patent number: 5528321Abstract: A method for providing a contact lens for a patient. According to this method, an optical preform is selected, and a resting position of the optical preform on the patient's eye is determined. An optical feature is also located on a patient's eye. Then, a reference position is located on the surface of the optical preform coincident with the optical feature on the patients eye, when the optical preform is in the resting position. Finally, the optical modification is provided on the optical preform at a location based on the reference position on the optical preform.Type: GrantFiled: May 20, 1994Date of Patent: June 18, 1996Assignee: Innotech, Inc.Inventors: Ronald D. Blum, Amitava Gupta
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Patent number: 5517259Abstract: Methods for providing a contact lens are described. According to a first embodiment, a patient is fitted with an optical preform and the position on the surface of the optical preform corresponding to the center location of the patients's pupil is identified. Then, the optical preform, a volume of polymerizable resin, and a mold comprising a casting zone are arranged, so that the resin occupies at least the intervening space between the mold and the optical preform in the area of the casting zone and so that the casting zone on the mold is aligned to a predetermined position with respect to the position on the surface of the optical preform corresponding to the center of the patient's pupil. Finally, the resin is polymerized to provide a contact lens with an optical modification corresponding to the casting zone.Type: GrantFiled: April 8, 1994Date of Patent: May 14, 1996Assignee: Innotech, Inc.Inventors: Ronald D. Blum, Amitava Gupta
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Patent number: 5512371Abstract: A method for making improved optical quality lenses is described. The method includes arranging a mold having a molding surface, a curable optical quality resin composition, and a plastic lens preform of optical quality material such that the resin composition is disposed between, and in contact with, the plastic lens preform and the mold. Upon curing, the resin composition forms a cured plastic attached portion that is bonded to the plastic lens preform. The resin composition and plastic lens preform are selected such that the attached portion has a higher scratch resistance, a lower chromatic aberration, and/or a higher ease of edging than the lens preform.Type: GrantFiled: March 18, 1994Date of Patent: April 30, 1996Assignee: Innotech, Inc.Inventors: Amitava Gupta, Ronald D. Blum, Venkatramani S. Iyer, Paul J. Nagg
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Patent number: 5480600Abstract: A method is provided for casting a progressive addition lens from: a mold incorporating a spherical portion and an add zone; a preformed lens having a convex curvature correlated with the concave curvature of the mold; and a polymerizable resin. The method includes the steps of: placing a predetermined volume of resin into a cavity of the mold; placing the preformed lens into the mold such that a layer of resin spreads out and covers any intervening space between the lens and the mold; and displacing superiorly or nasally by a predetermined magnitude the optical center of the preformed lens with respect to the geometrical center of the mold.Type: GrantFiled: March 24, 1993Date of Patent: January 2, 1996Assignee: Innotech, Inc.Inventors: Amitava Gupta, Ronald D. Blum
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Patent number: RE36150Abstract: A deformable-elastic intraocular lens comprising a deformable-elastic lens body of crosslinked acrylic material formed of copolymers of methacrylate and acrylate esters which are relatively hard and relatively soft at body temperature, crosslinked with a diacrylate ester to produce an acrylic copolymer having a substantially tack-free surface, a crosslink density of between .?.0.5.times.10.sup.-2 and 1.5.times.10.sup.-2 .!. .Iadd.0.23.times.10.sup.-1 and 1.66.times.10.sup.-1 .Iaddend.moles per liter, and glass transition temperature in the range of -30.degree. C. to 25.degree. C., a tensile modulus between 1000 and 3000 psi and a elongation a break of 100% or greater.Type: GrantFiled: October 3, 1995Date of Patent: March 16, 1999Assignee: Amo Puerto Rico, Inc.Inventor: Amitava Gupta