Methods and apparatus for producing ophthalmic lenses
First Claim
1. In a method of producing an ophthalmic lens, wherein an initial curvature is cut into a lens blank and is thereafter finished by a finishing tool having finishing curve characteristics substantially corresponding to prescription curve characteristics within a prescribed tolerance, the improvement comprising the steps of determining said finishing curve characteristics of said finishing tool, and producing said initial curvature in said lens blank such that differences between said finishing curve characteristics and said prescription curve characteristics are incorporated into said initial curvature.
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Accused Products
Abstract
An initial curvature is cut into a lens blank in a lens making machine, such as a lathe, and the curvature is subsequently finished by a finishing tool. The finishing tool has curve characteristics which correspond to those of a prescription within a prescribed tolerance. The curvature of the finishing tool is measured on a digital gauge, and those measurements are fed to a digital controller which actuates the lathe. As a result, an initial curvature is cut into the lens blank having characteristics which correspond to those of the finishing tool. The finishing operation can thus be performed more quickly, since less material needs to be removed from the initial curvature during the finishing operation.
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Citations
11 Claims
- 1. In a method of producing an ophthalmic lens, wherein an initial curvature is cut into a lens blank and is thereafter finished by a finishing tool having finishing curve characteristics substantially corresponding to prescription curve characteristics within a prescribed tolerance, the improvement comprising the steps of determining said finishing curve characteristics of said finishing tool, and producing said initial curvature in said lens blank such that differences between said finishing curve characteristics and said prescription curve characteristics are incorporated into said initial curvature.
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3. Apparatus for producing an initial curvature in an ophthalmic lens blank which is to be subsequently finished by a finishing tool having finishing curve characteristics substantially corresponding to prescription curve characteristics within a prescribed tolerance, said apparatus comprising:
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a cutter tool, supporting means for supporting said lens blank and cutter tool and effecting relative movement therebetween for producing said initial curvature, a digital controller connected to said supporting means for supplying control signals thereto for effecting the production of said initial curvature, and a digital gauge connected to said digital controller for measuring lap base and cross curve characteristics of a lap curvature of a lap portion of the finishing tool and for delivering to said digital controller signals indicative of such measured characteristics such that said digital controller actuates said supporting means for producing said initial curvature with characteristics corresponding to said finishing curve characteristics. - View Dependent Claims (4, 5)
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6. A method of producing an ophthalmic lens according to prescription curve characteristics, said method comprising the steps of:
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selecting a finishing tool according to said prescription curve characteristics; measuring finishing curve characteristics of said finishing tool; producing an initial curvature in a lens blank such that said finishing curve characteristics determine said initial curvature; and fining said initial curvature to finish a side of said ophthalmic lens. - View Dependent Claims (7)
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8. Apparatus for producing an initial curvature in an ophthalmic lens blank which is to be subsequently finished by a finishing tool having finishing curve characteristics substantially corresponding to prescription curve characteristics within a prescribed tolerance, said apparatus comprising:
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a digital gauge for measuring curve characteristics of a lap curvature of a lap portion of the finishing tool, a cutter tool, supporting means for supporting said lens blank and cutter tool and effecting relative movement therebetween for producing said initial curvature, and a digital controller connected to said digital gauge for receiving signal indicative of such measured characteristics to said support means and for supplying control signals to said supporting means to effect the production of said initial curvature, such that said digital controller actuates said supporting means for producing said initial curvature with characteristics corresponding to said finishing curve characteristics taking into consideration said measured curve characteristics of said lap portion of the finishing tool. - View Dependent Claims (9, 10, 11)
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Specification