UN ALGORITHME NON LISSE AVEC CONTR ^ OLE DE PROXIMIT E POUR DES FONCTIONS NON CONVEXES

A light modifying device for a liquid crystal display mounted on a PC board is provided with a filter and/or reflector of sheet material which is conveniently releasably installed between the liquid crystal display and the PC board to effect alteration of the properties of light passing through the liquid crystal display. Externally originating light which does not pass through the filter is reflected back to help light the LCD. For this purpose the surface of the filter adjacent the LCD includes a coating that is reflective, as well as light transmissive. The device is provided with securement means for holding the filter in place, but facilitating simple installation and removal.