OVERLAPPING POLARIZING PANELS GENERATING LIGHT AND DARK PATTERNS AND COLOUR PATTERNS

摘要

When placed between polarizers (10a, 10b) in certain positions, certain transparent colourless plastics considerably modify light transmission through the polarizers without producing colours (double sanchromatic filters). Similarly, certain other colourless plastics (11, 12) or an association of two or more sanchromatic filters (11, 12) produce colours at certain orientations of the polarizers. These observations are useful in producing optical panels for elements used to screen the light such as windows or blinds. Windows and blinds provide simultaneously various light screening options, such as plain dark, plain light, light and dark patterns, and colour patterns. A typical window consists of two slidingly overlapping polarizing sheets with crossed depolarization, a series of adjacent or alternated sanchromatic filters (11, 12) suitably fixed to the polarizers, and one or more colourless plastic sheets capable of producing colour, which may be inserted between the polarizers.