Fresnel spiral reflector and method for making same
AssigneeGeorgia Tech Research Institute
InventorsRichard A. Steenblik, Dar-Veig Ho
Life of this patent
Estimating the term…
Abstract
A spiral Fresnel reflector is formed by plotting a predetermined developed spiral on a flat sheet of reflecting material, cutting the flat sheet of reflecting material along the developed spiral and winding up the developed spiral until the spiral arms focus reflective light at a focal area. The developed spiral can have either a positive or a negative focal length.
Claims29
A method for forming a substantially Fresnel reflector, said method comprising the steps of:
- forming a flat reflective spiral of a predetermined shape;
- winding said spiral about an axis normal to the plane of said flat spiral whereby said spiral becomes angled to said plane in the radial direction so as to form a substantially Fresnel reflector having a focal area, and
- terminating said winding when said spiral defines a desired focal area.
A method for forming a substantially Fresnel reflector, said method comprising the steps of:
- providing a spiral pattern of a predetermined shape on a flat sheet of reflecting material, said shape being such that, when cut and wound, said spiral forms a substantially Fresnel reflector
- cutting said flat along said spiral pattern to form a flat spiral of reflecting material;
- and
- winding said spiral about an axis normal to the plane of said flat sheet to a degree sufficient that said spiral defines a desired focal area, whereby said spiral becomes angled to said plane in the radial direction so as to form a substantially Fresnel reflector having said focal area.
A substantially Fresnel spiral reflector comprising:
- a spiral length of flat reflective material, said spiral length having an inner end and an outer end, one of said ends being fixed and the other of said ends being circumferentially wound up in the direction of said spiral by a predetermined degree, said predetermined degree being such that the turns of said wound spiral define a predetermined focal area
- whereby each circumferential portion of said spiral is tilted in the radial direction from the plane of said spiral to focus light reflected from said spiral onto said focal area.
Dependencies are inferred from the claim text.