Light control material and method for making same

摘要

A light control material comprising a layer of photopolymer (131) having light traps (140) formed therein at selected locations. The photopolymer (131) layer constitutes a master from which embossments can be produced. The ligh traps (140) are formed in the master by reactively ion etching a layer of cured photopolymer (131) at selected locations to create fields of tapered structures (140). An embossment generated from the master contains fields of tapered structures (140) which correspond to those created in the master. The light control material is capable of operating in the reflective or transmissive modes. In the transmissive mode, the light traps (140) are coated with a reflective material, such as a reflective layer of metal. Light impinging on the light control material passes through the light control material except where the light enters the light trap (140). Light which enters the light trap (140) is absorbed. In the reflective mode, the entire surface of the light control material having the light traps (140) formed therein is coated with a reflective material such as metal. Light which enters the light traps (140) is reflected among the tapered structures (140) until substantially all of the light has been absorbed. Light which does not enter the light traps (140) is reflected. The method of the present invention can be used to produce color and black-and-white images as well as copy-resistant documents.