Abstract: A passive display device providing high resolution and contrast and very fast response time for presenting and erasing information is formed from a thin layer of a crystal material capable of forming color centers in an electric field, an electron injection source by tunnel effect which includes a first thin metal layer, an insulation barrier, and a very thin metal layer, and an electrode array for selectively controlling the path of the electrons passing through the very thin metal layer, by tunnel effect, into the crystal material, upon application of a suitable voltage across the metal layers, in accordance with the information to be displayed.

Abstract: A photosensitive composition including a photopolymerizable monomer system and a thermochromic substance which can be used in a phootographic reproduction process which avoids the use of liquid elements for developing and fixing. The process is based on the different dielectric constants and heat losses exhibited by a monomer and the corresponding polymer and the reaction of certain thermochromic substances which exhibit a specific threshold temperature above which these substances change from a colorless form to a colored, stable form.