Ophthalmic article inspection system
AssigneeBausch & Lomb Incorporated
InventorsGerald J. Frumusa, Thomas A. Brown, Ronald D. Spoor, Joseph D. Blasiak
Life of this patent
Estimating the term…
Abstract
An assembly and method for inspecting ophthalmic lenses includes a light source and a 360° light structuring aperture configured to direct structured light toward an open center where a lens is positioned for imaging by an imaging device positioned beneath the assembly. The structured light is directed at the entire periphery of the lens and is internally reflected by the lens in the manner of a fiber optic conduit whereby the lens appears dark at clear areas of the lens. If there are defects or imprints on the lens, the internally reflected light will scatter at that point and appear as a bright spot to the imaging device.
Claims25
A method of inspecting an ophthalmic lens having a 360° peripheral edge, comprising the step of directing structured, diffuse light at the entire 360° peripheral edge of the lens such that the structured light enters the lens only at the peripheral edge thereof and internally reflects within the lens, and wherein the internally reflected light diffracts upon encountering a marking on the lens, whereby clear areas of the lens appear dark due to said internal light reflection, and one or more markings on the lens appear bright due to said internally reflected light scattering and exiting the lens at said one or more markings.
A method for inspecting an ophthalmic lens having a 360° peripheral edge, said method comprising the steps of:
- a. providing a light source in an annular array;
- b. structuring and diffusing the light emitted by said light source into a 360° structured, diffuse light directed radially inwardly at a center;
- c. positioning an ophthalmic lens at said center such that said structured light is directed at the entire 360° peripheral edge of said lens whereby said structured light enters only at the peripheral edge of said lens with said lens behaving as a fiber optic conduit such that said structured light internally reflects along clear areas of said lens, and scatters at markings on said lens;
- and
- d. providing an imaging device directed at said ophthalmic lens, said imaging device receiving bright and dark signals from the ophthalmic lens with the bright signals indicating the position of one or more markings on the lens and dark signals indicating clear areas of the lens.
An assembly for inspecting an ophthalmic lens, said assembly comprising:
- a. a light source;
- b. an annular light structuring aperture located radially inwardly of said light source, said annular light structuring aperture having an open center and configured to structure light from said light source into 360° light rays which are directed radially inwardly to said open center;
- c. an annular diffuser positioned radially inwardly of said annular light structuring aperture for diffusing said structured light;
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- d. a lens holder for removably engaging and positioning said lens in said open center adjacent said light structuring aperture whereby the structured, diffuse light impinges upon said lens.
Dependencies are inferred from the claim text.