US 4,788,094 A · Light controlling sheet

Abstract

The disclosure relates to a light controlling sheet for use with indicators which includes a louver element including an arbitrary pattern of walls which are parallel to each other and opaque so as to absorb light, and an electrically conductive film which is mounted on one surface of the louver element. This film is porous so that the light from a light source may penetrate. The oblique light strikes the opaque walls of the louver element and is absorbed in the walls, while the substantially parallel light is permitted to pass through the space or transparent portion betwee the walls. The electrically conductive film not only acts as a protective cover for the louver element but also shields unwanted electromagnetic wave.

Claims4

Dependent claims

A light controlling sheet for use in indicators comprising:

a louver element including an arbitrary pattern of walls having openings therebetween, inner surfaces of said walls defining said openings and extending in a direction of thickness of said louver element, said walls being opaque such that oblique light striking the inner surfaces of said walls may be absorbed by said walls while substantially parallel light may only travel through said openings in a direction which is substantially parallel to said walls;
and
an electrically conductive film mounted on one surface of said louver element, said film permitting light to pass through openings therein, said film acting as a protective cover for said louver element and acting to avoid electromagnetic waves.

Dependencies are inferred from the claim text.

Light controlling sheet

Life of this patent

Light controlling sheet

Life of this patent

Abstract

Claims4