METHOD OF FORMING AN OPTICAL ELEMENT OF REDUCED THICKNESS

• US 3,829,536 A
• Filed: 04/30/1973
• Issued: 08/13/1974
• Est. Priority Date: 04/05/1971
• Status: Expired due to Term

• Current Assignee: Allergan SPA (Abbvie Incorporated)
• Original Assignee: Luis W. Alvarez
• Inventors: Alvarez, Luis W.
• Primary Examiner(s): White, Robert F.
• Assistant Examiner(s): Auville, Gene
• Application Number:
  US05/355,624
• Time in Patent Office: 470 Days
• Field of Search: 264/1,162,219,227 29/411,425,557 425/808,DIG.30 350/211
• US Class Current: 264/2.5
• CPC Class Codes: B29D 11/00269 Fresnel lenses
• CPC Class Codes: G02B 3/0081 having one or more elements with analytic function to create variable power variable magnification in general G02B15/00
• CPC Class Codes: G02B 3/08 with discontinuous faces, e.g. Fresnel lens diffractive Fresnel lenses G02B5/1876

Abstract

An optical element of reduced thickness is formed by a mosaic of discrete lens faces, the lens faces together deflecting light in a manner equivalent to a conventional optical element of much greater thickness. Process and apparatus for the production of the lens element is included.

Claims

1. A process for producing a fresnelled optical element from a matrix of discrete elements comprising the steps of:

providing a plurality of discrete elongate elements, each element having first and second ends with a plurality of elongate side surfaces therebetween;

aligning said elongate elements in side-by-side relation with said first ends forming a common surface and said elongate side surfaces of each element in contiguous contacting relation with adjacent elements, said side surfaces permitting relative movement between said elements in the direction of the elongation of said elements and said elongate side surfaces inhibiting relative rotation of said elements about the direction of elongation of said elements;

holding the elements to prevent relative movement at said side surfacEs in the direction of elongation of said elements, forming a continuous optical surface on the common surface defined by the first ends of said aligned elements;

releasing said hold on said elements;

realigning said elements in the direction of elongation of said elements to a second aligned position with the peak of the first common ends of each element being on a common surface, said elements during said realigning being maintained in said side-by-side relation with relative movement occurring at said contiguous contacting elongate side surfaces;

holding the elements in fixed relative alignment in the second aligned position to form a fresnelled matrix of said continuous optical surface;

forming optical material over the surface defined by the first common ends of said elements to form a first optical surface complementary to the surface defined by said first common ends of said elements; and

forming a continuous second optical surface on the surface of said optical material on the optically opposite side of said first surface.

2. A process for producing the matrix of a fresnelled optical element from a matrix of discrete elements comprising the steps of:

providing a plurality of discrete elongate elements, each element having first and second ends with a plurality of elongate side surfaces therebetween;

aligning said elongate elements in side-by-side relation with said first ends forming a common surface and said elongate side surfaces of each element in contiguous contacting relation with adjacent elements, said side surfaces permitting relative movement between said elements in the direction of the elongation of said elements and said elongate side surfaces inhibiting relative rotation of said elements about the direction of elongation of said elements;

holding the elements to prevent relative movement at said side surfaces in the direction of elongation of said elements, forming a continuous optical surface on the common surface defined by the first ends of said aligned elements;

releasing said hold on said elements;

realigning said elements in the direction of elongation of said elements to a second aligned position with the peak of the first common ends of each element being on a common surface, said elements during said realigning being maintained in said side-by-side relation with relative movement occurring at said contiguous contacting elongate side surfaces; and

, holding the elements in fixed relative alignment in the second aligned position to form a fresnelled matrix of said continuous optical surface;

forming fluidized material over the surface defined by the first common ends of said elements to form a first female surface complementary to the surface defined by the first common ends of said element.

3. The process of claim 2 and including the step of forming fluidized optical material against said female surface;

and, forming a continuous second optical surface on the surface optical material which is opposite said formed surface to form a lens.

4. A process for producing a fresnel matrix of first and second optical elements for use in overlying relation, said process comprising the steps of:

providing first and second sets of discrete elongate elements, each elongate element having first and second ends with a plurality of elongate side surfaces therebetween;

aligning the elongate elements of each set in parallel side-by-side relation with said first ends of each element forming a common surface for each set of elements and said elongate side-by-side surfaces in each set of elements in contiguous contacting relation, said side surfaces permitting relative movement between the elements of each set in a direction of the elongation of said elements and said elongate side surfaces preventing relative rotation of said elements about said direction of elongation of said elements of each set;

aligning the elements of both sets to a first angular relation with respect to a preselected plane;

holding the elements of each set to prevent relative movement iN the direction of elongation of said elements;

forming first and second continuous optical surfaces on the common surfaces of said first and second element sets respectively;

releasing said hold on said element sets;

realigning said elements of each set in the direction of elongation of said elements to a second angular position with respect to said preselected plane;

realigning said elements in the direction of elongation of said elements to a second aligned position with the peak of the first common ends of each element being on a common surface;

said elements during said realigning being maintained in said side-by-side relation with relative movement occurring at said contiguous contacting surfaces;

holding the elements of each of the first and second sets in fixed relative alignment in the second aligned positions to form a fresnelled matrix of said continuous optical surfaces on each element set in said second realigned position; and

, forming fluidized material over the surface defined by each element set at the first ends of said elements to form a first optical surface complementary to the surface of said first element set and to form a second surface complementary to the surface of said second optical group.

5. The process of claim 4 and wherein said formed fluidized material is optical material and including the further step of forming optical surfaces on the surface of said formed optical materials on the optically opposite side of said first surfaces.