Back to results
US 5,182,444 AGranted
Split lens displaced long from each other along plane of cut
AssigneeDigital Equipment Corporation
InventorJames W. Howard
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeDigital Equipment Corporation
InventorJames W. Howard
Estimating the term…
A method and apparatus for measuring the focus and tracking of a light beam on a medium in an optical data storage system. A split lens, comprising two halves of a lens separated along the optical axis and displaced from each other along the plane of the cut, is used to focus the light reflected or refracted from the medium onto a quad-cell. The quad cell comprises four light sensors arranged in four quadrants about a center point. According to the invention, the amount of light incident on quadrants of the quad-cell indicates the focus and alignment of the light beam on the medium. In accordance with another aspect of the invention, the above apparatus is used to measure the collimation or distribution of intensity of a light beam. Another aspect of the invention is the manufacture of the split lens. A lens is sawed into two halves and the halves are mounted using a housing displaced from each other along the plane of the cut.
A method of manufacturing a split lens, comprising:
A method of manufacturing a split lens, comprising:
A split lens manufactured by the steps of
A split lens manufactured by the steps of
Dependencies are inferred from the claim text.