METHOD OF MAKING AN ARBITRARY SURFACE OPTICAL ELEMENT
An arbitrary surface optical element, such as a mirror for use in a rear projection television, includes a non-optical portion and an optical portion. The non-optical portion circumscribes the optical portion and has a thickness greater than the optical portion. Accordingly, the two portions cool at approximately the same rate, thereby minimizing warpage from differential cooling.
1 . A method of forming an optical element, comprising:
molding a resin into a part with a mold, the part having a non-optical portion and an optical portion, the non-optical portion having a thickness greater than the optical portion;
cooling the part; and
applying thin film onto the part.
2 . The method of claim 1 , wherein the applying thin film includes applying one or more of a polarizing layer, a photochromic layer, a melanin layer, a mirror layer, a color filter, or an infrared filter, via evaporation.
3 . The method of claim 1 , wherein the applying thin film includes applying one or more of a polarizing layer, a photochromic layer, a melanin layer, a mirror layer, a color filter, or an infrared filter via lamination.
4 . The method of claim 3 , wherein the resin includes a thermoplastic material and wherein the lamination includes laminating a protective film to the part.
5 . The method of claim 4 , further comprising using a pressure sensitive or thermo set adhesive that has a higher melt temperature than either the film or part to ensure adhesion during the lamination.
6 . The method of claim 4 , wherein the lamination includes applying a protective coating to the reflective film.
7 . The method of claim 1 , wherein the molding includes using a mold that becomes part of the optical element.
8 . The method of claim 1 , wherein the molding includes applying vacuum from a first side of the mold and pressure from a second side of the mold.
9 . The method of claim 1 , wherein the non-optical portion includes at least one rib.
10 . The method of claim 1 , wherein the non-optical portion extends outward from the optical portion with a dimension that is at least about twice the thickness of the optical portion.