← Back to Patent Explorer
US5141677A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of hot stamping intraocular lens bodies

Assignee: 3M Co
•
Filing: 1991-01-22
•
Granted: 1992-08-25
•
Expires: 2011-01-22
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A method for manufacturing an intraocular lens from a cell cast sheet of high molecular weight polymethylmethracrylate (PMMA). A lens blank having a lens generation area with a surface contoured to correspond to the desired contour of the finished lens is machined from the sheet of PMMA to a predetermined precompensated size larger than desired to acccommodate normalizing shrinkage. The lens blank is normalized by heating the blank in a vacuum oven. The vacuum is released from the oven by introducing dry nitrogen. A stamping die is provided. An optical embossing surface of the stamping die is contoured as a physical negative of the lens generation area and bears a physical negative of the desired optical surface structure of the lens, such as a multifocal diffractive zone plate. The embossing surface of the stamping die is forced into engagement with the surface of the lens blank at a predetermined stamping pressure and for a predetermined stamping dwell time. Sufficient heat or ultrasonic energy is applied to the lens generation area of the lens blank to heat the lens generation area to a temperature between the glass transition temperature and the melt temperature of the polymer, and emboss the surface structure onto the lens generation area. The embossing surface of the stamping die is removed from the lens blank following the expiration of the stamping dwell time.

Inventors

  • 👤 Terry M. Fogarty

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 12:13
CPC Classifications
B; B29; B29D; B29D11/00; B29D11/02; B29D11/023; A; A61; A61F; A61F2/00; A61F2/02; A61F2/14; A61F2/16; B29C; B29C59/00; B29C59/02; B29K; B29K2033/00; B29K2033/04; B29K2033/12

Claims Analysis

Total Claims: 50
Claim 1
Independent Claim 217 words
A method for manufacturing an intraocular lens body from a sheet of polymer characterized by a glass transition temperature and a melt flow temperature, including: machining, from the sheet of polymer, a lens member having a lens generation area with a surface and contoured to correspond to the desired contour of the finished lens, the lens member machined to a predetermined precompensated size larger than desired to accommodate normalizing shrinkage; normalizing the lens member and causing the lens member to shrink to the desired size; providing a stamping die having an optical embossing surface contoured as a physical negative of the lens generation area and bearing a physical negative of desired optical surface structure of the lens; forcing the optical embossing surface of the stamping die and the surface of the lens member into engagement with one another at a predetermined stamping pressure and for a predetermined stamping dwell time period; applying sufficient energy to heat the surface of the lens member to a temperature between the glass transition temperature and the melt flow temperature of the polymer member and emboss the optical surface structure onto the surface of the lens generation area; and removing the optical embossing surface of the stamping die from the polymer lens member following the expiration of the stamping dwell time period.
Claim 2
Independent Claim 217 words
A method for manufacturing an intraocular lens body from a sheet of polymer characterized by a glass transition temperature and a melt flow temperature, including: machining, from the sheet of polymer, a lens member having a lens generation area with a surface and contoured to correspond to the desired contour of the finished lens, the lens member machined to a predetermined precompensated size larger than desired to accommodate normalizing shrinkage; normalizing the lens member and causing the lens member to shrink to the desired size; providing a stamping die having an optical embossing surface contoured as a physical negative of the lens generation area and bearing a physical negative of desired optical surface structure of the lens; forcing the optical embossing surface of the stamping die and the surface of the lens member into engagement with one another at a predetermined stamping pressure and for a predetermined stamping dwell time period; applying sufficient energy to heat the surface of the lens member to a temperature between the glass transition temperature and the melt flow temperature of the polymer member and emboss the optical surface structure onto the surface of the lens generation area; and removing the optical embossing surface of the stamping die from the polymer lens member following the expiration of the stamping dwell time period.
Claim 3
Dependent Claim 13 words
The method of claim 1 wherein applying energy includes heating the stamping die.
Claim 4
Dependent Claim 20 words
The method of claim 1 and further including cooling the stamping die and lens member during the dwell time period.
Claim 5
Dependent Claim 24 words
The method of claim 1 and further including preheating the lens member before forcing the die and lens member into engagement with one another.
Claim 6
Dependent Claim 22 words
The method of claim 1 wherein applying energy includes applying ultrasonic energy for at least a portion of the dwell time period.
Claim 7
Dependent Claim 39 words
The method of claim 1 wherein forcing the embossing surface and the lens member into engagement with one another includes fixedly positioning the lens member and forcing the embossing surface into engagement with the surface of the lens member.
Claim 8
Dependent Claim 19 words
The method of claim 1 wherein machining the lens member includes machining the lens member from a polymethylmethacrylate sheet.
Claim 9
Dependent Claim 19 words
The method of claim 1 wherein normalizing the lens member includes heating the lens member in a vacuum oven.
Claim 10
Dependent Claim 18 words
The method of claim 8 and further including releasing the vacuum from the oven by introducing dry nitrogen.
Claim 11
Dependent Claim 20 words
The method of claim 9 and storing the normalized lens member in a container having a low vapor transmission rate.
Claim 12
Dependent Claim 25 words
The method of claim 1 and further including forcing the embossing surface and the surface of the lens member into engagement in an anaerobic environment.
Claim 13
Dependent Claim 65 words
The method of claim 1 wherein providing a stamping die includes providing a stamping die having an embossing surface configured to first contact a center of the surface of the lens member and having an area of contact with the surface which progressively extends radially outwardly to facilitate gas venting as the embossing surface is forced into engagement with the surface of the lens member.
Claim 14
Dependent Claim 35 words
The method of claim 1 wherein providing the polymer lens member includes providing a lens member having a gas vent groove extending across at least a portion of the surface of the lens generation area.
Claim 15
Dependent Claim 90 words
The method of claim 1 wherein: providing a stamping die includes providing a stamping die having an embossing surface configured to first contact a center of the surface of the lens member and having an area of contact with the surface which progressively extends radially outwardly to facilitate gas venting as the embossing surface is forced into engagement with the surface of the lens member; and providing the polymer lens member includes providing a lens member having a gas vent groove extending across at least a portion of the surface.
Claim 16
Dependent Claim 29 words
The method of claim 1 wherein providing the stamping die includes providing a stamping die having an embossing surface bearing a physical negative of a complex optical surface structure.
Claim 17
Dependent Claim 28 words
The method of claim 15 wherein providing the stamping die includes providing a stamping die having an embossing surface bearing a physical negative of a multicurved optical surface.
Claim 18
Dependent Claim 28 words
The method of claim 15 wherein providing the stamping die includes providing a stamping die having an embossing surface bearing a physical negative of an aspheric optical surface.
Claim 19
Dependent Claim 29 words
The method of claim 15 wherein providing the stamping die includes providing a stamping die having an embossing surface bearing a physical negative of a diffractive multifocal optical surface.
Claim 20
Dependent Claim 29 words
The method of claim 15 wherein providing the stamping die includes providing a stamping die having an embossing surface bearing a physical negative of a refractive multifocal optical surface.
Claim 21
Dependent Claim 28 words
The method of claim 15 wherein providing the stamping die includes providing a stamping die having an embossing surface bearing a physical negative of a toric optical surface.
Claim 22
Dependent Claim 29 words
The method of claim 1 wherein providing the stamping die includes providing a stamping die having an embossing surface bearing a physical negative of a single curve optical surface.
Claim 23
Dependent Claim 209 words
The method of claim 1 wherein: fabricating the lens member includes fabricating a one-piece polymer lens blank including the contoured lens generation area and a contoured haptic generation area with a surface about the periphery of the lens generation area; providing the stamping die includes providing a stamping die having a contoured optical embossing surface and a peripheral haptic embossing surface contoured as a physical negative of the haptic generation area and bearing a physical negative of desired haptic structure of the lens; forcing the embossing surface includes forcing the optical embossing surface and haptic embossing surface of the stamping die and the respective lens generation and haptic generation area surfaces of the lens blank into engagement with one another at a predetermined stamping pressure and for a predetermined stamping dwell time period; applying sufficient energy includes applying sufficient energy to heat the surfaces of the lens member to temperatures between the glass transition temperature and the melt flow temperature of the polymer member and emboss the optical surface structure and haptic structure onto the surfaces of the lens blank; and removing the embossing surface includes removing the optical embossing surface and the haptic embossing surface from the lens blank following the expiration of the stamping dwell time period.
Claim 24
Independent Claim 226 words
A method for manufacturing an intraocular lens body from a cell cast sheet of high molecular weight polymethylmethacrylate characterized by a glass transition temperature and a melt flow temperature, including: machining from the sheet of polymethylmethacrylate a lens blank having a lens generation area with a surface and contoured to correspond to the desired contour of the finished lens, the lens blank machined to a predetermined precompensated size larger than desired to accommodate normalizing shrinkage; normalizing the lens blank by heating the lens blank in a vacuum oven; releasing the vacuum from the oven by introducing dry gas; providing a stamping die having an optical embossing surface contoured as a physical negative of the lens generation area and bearing a physical negative of desired optical surface structure of the lens; forcing the embossing surface of the stamping die into engagement with the lens generation area of the blank at a predetermined stamping pressure and for a predetermined stamping dwell time; applying sufficient energy to the lens generation area of the lens blank to heat the lens generation area to a temperature between the glass transition temperature and the melt temperature and emboss the optical surface structure onto the surface of the lens generation area; and removing the optical embossing surface of the stamping die from the lens blank following the expiration of the stamping dwell time.
Claim 25
Independent Claim 226 words
A method for manufacturing an intraocular lens body from a cell cast sheet of high molecular weight polymethylmethacrylate characterized by a glass transition temperature and a melt flow temperature, including: machining from the sheet of polymethylmethacrylate a lens blank having a lens generation area with a surface and contoured to correspond to the desired contour of the finished lens, the lens blank machined to a predetermined precompensated size larger than desired to accommodate normalizing shrinkage; normalizing the lens blank by heating the lens blank in a vacuum oven; releasing the vacuum from the oven by introducing dry gas; providing a stamping die having an optical embossing surface contoured as a physical negative of the lens generation area and bearing a physical negative of desired optical surface structure of the lens; forcing the embossing surface of the stamping die into engagement with the lens generation area of the blank at a predetermined stamping pressure and for a predetermined stamping dwell time; applying sufficient energy to the lens generation area of the lens blank to heat the lens generation area to a temperature between the glass transition temperature and the melt temperature and emboss the optical surface structure onto the surface of the lens generation area; and removing the optical embossing surface of the stamping die from the lens blank following the expiration of the stamping dwell time.
Claim 26
Dependent Claim 14 words
The method of claim 23 wherein applying sufficient energy includes heating the stamping die.
Claim 27
Dependent Claim 21 words
The method of claim 23 wherein applying sufficient energy includes applying ultrasonic energy to the engaged stamping die and lens blank.
Claim 28
Dependent Claim 57 words
The method of claim 23 wherein providing a stamping die includes providing a stamping die having an embossing surface configured to first contact a central portion of the lens generation area and having an area of contact with the lens generation area which extends progressively radially outwardly as the embossing surface and lens generation area are engaged.
Claim 29
Dependent Claim 31 words
The method of claim 23 wherein providing the lens blank includes providing a lens blank having a gas vent groove extending across at least a portion of the lens generation area.
Claim 30
Dependent Claim 92 words
The method of claim 23 wherein: providing a stamping die includes providing a stamping die having an embossing surface configured to first contact a center of the surface of the lens member and having an area of contact with the surface which progressively extends radially outwardly to facilitate gas venting as the zone plate reproducing surface is forced into engagement with the surface of the lens member; and providing the polymer lens member includes providing a lens member having a gas vent groove extending across at least a portion of the surface.
Claim 31
Dependent Claim 162 words
The method of claim 23 wherein: machining a lens blank includes machining a one piece blank including a contoured lens generation area and a contoured haptic generation area with a surface about the periphery of the lens generation area; providing the stamping die includes providing a stamping die having a contoured optical embossing surface and a peripheral haptic embossing surface contoured as a physical negative of the haptic generation area and bearing a physical negative of desired haptic structure of the lens; forcing the embossing surface includes forcing the optical embossing surface and haptic embossing surface of the stamping die and the respective lens generation and haptic generation area surfaces of the lens blank into engagement with one another; applying sufficient energy includes applying sufficient energy to emboss the optical surface structure and haptic structure onto the surfaces of the lens blank; and removing the embossing surface includes removing the optical embossing surface and the haptic embossing surface from the lens blank.
Claim 32
Dependent Claim 29 words
The method of claim 23 wherein providing the stamping die includes providing a stamping die having an embossing surface bearing a physical negative of a single curve optical surface.
Claim 33
Dependent Claim 26 words
The method of claim 23 wherein providing the stamping die includes providing a stamping die having an embossing surface bearing a physical negative of a complex
Claim 34
Dependent Claim 28 words
The method of claim 31 wherein providing the stamping die includes providing a stamping die having an embossing surface bearing a physical negative of a multicurved optical surface.
Claim 35
Dependent Claim 28 words
The method of claim 31 wherein providing the stamping die includes providing a stamping die having an embossing surface bearing a physical negative of a toric optical surface.
Claim 36
Dependent Claim 28 words
The method of claim 31 wherein providing the stamping die includes providing a stamping die having an embossing surface bearing a physical negative of an aspheric optical surface.
Claim 37
Dependent Claim 29 words
The method of claim 31 wherein providing the stamping die includes providing a stamping die having an embossing surface bearing a physical negative of a diffractive multifocal optical surface.
Claim 38
Dependent Claim 29 words
The method of claim 31 wherein providing the stamping die includes providing a stamping die having an embossing surface bearing a physical negative of a refractive multifocal optical surface.
Claim 39
Independent Claim 198 words
A method for manufacturing an intraocular lens body, including: fabricating a polymer lens member having a lens generation area with a surface and contoured to correspond to the desired contour of the finished lens, the polymer characterized by a glass transition temperature and a melt flow temperature; providing a stamping die having an optical embossing surface contoured as a physical negative of the lens generation area and bearing a physical negative of a desired complex optical surface structure of the lens, the complex surface structure selected from the set including a multicurved optical surface, a multicurved aspheric optical surface, a diffractive multifocal optical surface, a refractive multifocal optical surface, and a toric optical surface; forcing the optical embossing surface of the stamping die and the surface of the lens member into engagement with one another at a predetermined stamping pressure and for a predetermined stamping dwell time period; applying sufficient energy to heat the surface of the lens member and emboss the complex optical surface structure onto the surface of the lens generation area; and removing the optical embossing surface of the stamping die from the polymer lens member following the expiration of the stamping dwell time period.
Claim 40
Independent Claim 198 words
A method for manufacturing an intraocular lens body, including: fabricating a polymer lens member having a lens generation area with a surface and contoured to correspond to the desired contour of the finished lens, the polymer characterized by a glass transition temperature and a melt flow temperature; providing a stamping die having an optical embossing surface contoured as a physical negative of the lens generation area and bearing a physical negative of a desired complex optical surface structure of the lens, the complex surface structure selected from the set including a multicurved optical surface, a multicurved aspheric optical surface, a diffractive multifocal optical surface, a refractive multifocal optical surface, and a toric optical surface; forcing the optical embossing surface of the stamping die and the surface of the lens member into engagement with one another at a predetermined stamping pressure and for a predetermined stamping dwell time period; applying sufficient energy to heat the surface of the lens member and emboss the complex optical surface structure onto the surface of the lens generation area; and removing the optical embossing surface of the stamping die from the polymer lens member following the expiration of the stamping dwell time period.
Claim 41
Dependent Claim 13 words
The method of claim 37 wherein applying energy includes heating the stamping die.
Claim 42
Dependent Claim 20 words
The method of claim 37 and further including cooling the stamping die and lens member during the dwell time period.
Claim 43
Dependent Claim 24 words
The method of claim 37 and further including preheating the lens member before forcing the die and lens member into engagement with one another.
Claim 44
Dependent Claim 22 words
The method of claim 37 wherein applying energy includes applying ultrasonic energy for at least a portion of the dwell time period.
Claim 45
Dependent Claim 17 words
The method of claim 37 wherein fabricating the lens member includes fabricating the lens member from polymethylmethacrylate.
Claim 46
Dependent Claim 35 words
The method of claim 37 wherein providing the polymer lens member includes providing a lens member having a gas vent groove extending across at least a portion of the surface of the lens generation area.
Claim 47
Dependent Claim 90 words
The method of claim 38 wherein: providing a stamping die includes providing a stamping die having an embossing surface configured to first contact a center of the surface of the lens member and having an area of contact with the surface which progressively extends radially outwardly to facilitate gas venting as the embossing surface is forced into engagement with the surface of the lens member; and providing the polymer lens member includes providing a lens member having a gas vent groove extending across at least a portion of the surface.
Claim 48
Dependent Claim 193 words
The method of claim 37 wherein: fabricating the lens member includes fabricating a one-piece polymer lens blank including the contoured lens generation area and a contoured haptic generation area with a surface about the periphery of the lens generation area; providing the stamping die includes providing a stamping die having a contoured optical embossing surface and a peripheral haptic embossing surface contoured as a physical negative of the haptic generation area and bearing a physical negative of desired haptic structure of the lens; forcing the embossing surface includes forcing the optical embossing surface and haptic embossing surface of the stamping die and the respective lens generation and haptic generation area surfaces of the lens blank into engagement with one another at a predetermined stamping pressure and for a predetermined stamping dwell time period; applying sufficient energy includes applying sufficient energy to heat the surfaces of the lens member to emboss the optical surface structure and haptic structure onto the surfaces of the lens blank; and removing the embossing surface includes removing the optical embossing surface and the haptic embossing surface from the lens blank following the expiration of the stamping dwell time period.
Claim 49
Dependent Claim 18 words
The method of claim 37 wherein fabricating the lens member includes fabricating the lens member from Perspex PMMA.
Claim 50
Dependent Claim 36 words
The method of claim 37 wherein applying energy includes applying sufficient energy to heat the surface of the lens member to a temperature between the glass transition temperature and the melt flow temperature of the member.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-08-25 1996-02-24 1996-08-25 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-08-25 2000-02-24 2000-08-25 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-08-25 2004-02-24 2004-08-25 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag