Optics: measuring and testing – By polarized light examination – With light attenuation
Patent
1993-10-20
1995-06-27
Pham, Hoa Q.
Optics: measuring and testing
By polarized light examination
With light attenuation
356375, 33200, G01B 1124
Patent
active
054284481
ABSTRACT:
A method and apparatus for determining the size and shape to which a finished lens used to make an eyeglass lens is to be cut. Coordinates which define the outer perimeter of a lens are determined by illuminating either an eyeglass frame or a lens. An image of the shadow of the frame or lens is captured by an imaging device. A first linear polarizing filter is positioned optically between a light source and the membrane. A second linear polarizing filter, oriented at 180.degree. from the first filter, is placed optically between the membrane and the camera. Thus, the first and second polarizing filters allow a high definition image to be attained for substantially transparent plastic. A general purpose computer: (1) identifies the edges of the image so as to define the perimeter; (2) orients the image by identifying an orientation line placed upon a lens, if the image is of a lens which is not within a frame; and (3) measures the distance between lenses if an eyeglass frame is being measured. If an eyeglass frame is being measured, then a depth gauge indicator is used to measure the depth of a groove in the frame into which a lens is recessed when mounted in the eyeglass frame. Once the coordinates of the lens are determined, they may be verified by comparison with the frames or lens from which they were derived. Further, the coordinates of the outer perimeter of the edged lens may be determined to verify the accuracy of the operation.
REFERENCES:
patent: 4524419 (1985-06-01), Headlund et al.
patent: 4575751 (1986-03-01), Duschl
patent: 4737918 (1988-04-01), Langlois et al.
patent: 4798459 (1989-01-01), Joncour
patent: 4817024 (1989-03-01), Saigoh
patent: 5131753 (1992-07-01), Pine et al.
patent: 5307150 (1994-04-01), Lecerf et al.
Augen Wecken Plasticos S.R.L. de C.V.
Pham Hoa Q.
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