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US 4,049,756 AGranted
Method of making microfiche laminate having apertures with doublet lenses
AssigneeIzon Corporation
InventorGeorge J. Yevick
Life of this patent
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Abstract
Method for making a microfiche structure consisting of a laminate of an opaque, apertured web sandwiched between two transparent sheets. The transparent material partially extends into each aperture to thereby define, for each aperture, an optical doublet. The laminate may be continuously formed by compression, as by rolls.
Claims2
In a method of forming a microfiche laminate having an apertured opaque sheet with facing plano-convex lenses forming a doublet lens in at least one through aperture of said sheet, the steps comprising:
- forming opposite concavities on opposite sides of an apertured opaque sheet, two of said opposite concavities being contiguous to at least one aperture;
- disposing transparent thermoplastic sheet material on said opposite sides of said apertured sheet;
- applying heat and pressure to said thermoplastic material on said opposite sides causing said material to flow into said concavities and only partially into said apertures to form said facing plano-convex lenses.
Dependencies are inferred from the claim text.