US 4,151,582 A · Point array sheet lighting apparatus

Abstract

An illumination device for establishing an array of point light sources, wherein the light sources are generally closely spaced. In a first embodiment a planar substrate is provided with an array of apertures. One surface of the substrate is coated with a first coating having a first index of refraction, the coating extending into the sides of the apertures. A second coating having a second and higher index of refraction is applied on top of the first coating and is coextensive therewith. Light fed into the edges of the second coating passes by internal reflection to the apertures where it exits, parallel with the aperture axes. In a second embodiment, the array of point sources is defined by beam-compressor lenses supported on a rigid, planar substrate. Each column of lenses is positioned adjacent an edge of an internally reflecting sheet, there being as many sheets as columns. An opposite edge of each sheet receives light, to thereby illuminate the input ends of the beam-compressor lenses. In a third embodiment, reflecting faces are formed integrally with a planar sheet of a transparent substance. Light fed edgewise into the sheet is reflected upwardly by the arrayed faces.

Claims12

Dependent claims

An illuminating device for establishing an array of closely-spaced individual sources of light, said device including,

(a) a generally planar substrate having an array of individual apertures extending therethrough, said apertures being generally normal to the plane of the substrate,
(b) a first coating on one surface of said substrate, said coating being of a transparent material having a first index of refraction, said first coating extending from said one surface into the surfaces of said individual apertures,
(c) a second coating on top of and in contact with said first coating and being coextensive therewith, said second coating being transparent and having a second index of refraction greater than said first index of refraction,
(d) the surface of said second coating having an annular depression opposite each aperture in said substrate, each depression being of a depth at least equal to the thickness of said second coating,
(e) whereby light directed to the edges of said coatings will be transmitted by internal reflection to the apertures and will exist from the apertures in the direction substantially normal to the plane of the substrate.

2 more elements

Dependencies are inferred from the claim text.

Point array sheet lighting apparatus

Life of this patent

Point array sheet lighting apparatus

Life of this patent

Abstract

Claims12