Point array sheet lighting apparatus

• US 4,151,582 A
• Filed: 03/24/1978
• Issued: 04/24/1979
• Est. Priority Date: 12/26/1974
• Status: Expired due to Term

• Current Assignee: IZON Corporation
• Original Assignee: IZON Corporation
• Inventors: Grunberger, Lawrence W.
• Primary Examiner(s): Nelson, Peter A.
• Application Number:
  US05/889,736
• Time in Patent Office: 396 Days
• Field of Search: 362/31, 362/32, 362/297, 362/300, 350/96 R, 350/96 B, 350/286, 250/227, 340/380, 40/130 K, 116/DIG. 5, 116/DIG. 26, 428/137
• US Class Current: 362/622
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/2817 using reflective elements to split or combine optical signals
• CPC Class Codes: G02B 6/32 having lens focusing means positioned between opposed fibre ends with lens being an integral part of the single fibre end G02B6/262
• CPC Class Codes: G02B 6/4298 coupling with non-coherent light sources and/or radiation detectors, e.g. lamps, incandescent bulbs, scintillation chambers
• CPC Class Codes: G03B 21/11 for microfilm reading
• CPC Class Codes: Y10S 385/901 Illuminating or display 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.

Claims

1. 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. The illuminating device of claim 1 wherein said substrate is opaque.

3. The illuminating device of claim 1 wherein the two transparent coatings fill the said apertures.

4. The illuminating device of claim 1 wherein the two transparent coatings do not completely fill said apertures, thereby defining an elongated and generally cylindrical void in each aperture centrally and longitudinally thereof.

5. The illuminating device of claim 1 wherein the entrances on said one surface to said apertures is chamfered.

6. An illuminating device for producing an array of point sources of light, including,

(a) a transparent sheet,

(b) a plurality of light-reflecting faces each oriented in the same direction and carried by and integral with said sheet, said reflecting faces positioned between the two surfaces of said sheet,

(c) an edge of said sheet adapted to receive light in the direction of said faces,

(d) said light reflecting faces being spaced apart from each other and each extending from one surface of said sheet to the other surface of said sheet, each reflecting face being defined by a void extending from one surface of said sheet towards its other surface, said void having a wall, the wall defining said reflecting face, each of said reflecting faces being planar and being at an angle of 45°

with a surface of said sheet, said plurality of reflecting faces being defined by n vertical columns spaced a apart and m horizontal rows spaced b apart, one edge of said sheet receiving light parallel to the plane of the sheet, at an angle alpha with respect to the said rows, said faces each being of width w measured in a direction normal to the direction of the light, the relation between the quantities being that, alpha=arctan b/na, and, nw=b cos (alpha).

7. The illuminating device of claim 6 wherein said sheet is of thickness w and wherein each reflecting face is planar and intersects the plane of said transparent sheet at an angle of 45°

.

8. The illuminating sheet of claim 6 wherein said transparent sheet is provided with a plurality of integral strips, the strips being aligned at a fixed angular relationship with respect to the rows of said array of reflecting faces, said strips being bent out of the plane of said sheet, and laminated together at their free ends to thereby define a light-input face.

9. An illuminating device for producing an array of point sources of light, including,

(a) a transparent sheet,

(b) a plurality of light-reflecting faces each oriented in the same direction and carried by and integral with said sheet, said reflecting faces positioned between the two surfaces of said sheet, said reflecting faces being distributed over the said sheet and forming a two-dimensional array,

(c) an edge of said sheet adapted to receive light in the direction of said faces,

(d) said light reflecting faces being spaced apart from each other and each extending from one surface of said sheet to the other surface of said sheet.

10. The combination of an illuminating device and a microfiche, the illuminating device producing an array of point sources of light for illuminating developed microimages on a microfiche, each point source of light being optically aligned with one of the developed microimages, the combination including,

(a) a transparent sheet,

(b) a plurality of light-reflecting faces each oriented in the same direction and carried by and integral with said sheet, said reflecting faces positioned between the two surfaces of said sheet, said reflecting faces being distributed over the said sheet and forming a two-dimensional array,

(c) an edge of said sheet adapted to receive light in the direction of said faces,

(d) said light reflecting faces being spaced apart from each other and each extending from one surface of said sheet to the other surface of said sheet,

(e) a microfiche having a plurality of developed microimages, each said light reflecting face being optically aligned with a microimage of the microfiche, whereby light fed into an edge of the sheet in the direction of the reflecting faces is reflected by the reflecting faces out of the plane of the sheet and towards and through the microimages for subsequent viewing.

11. The illuminating device of claim 10 wherein said sheets are in juxtaposed, touching relationship at a region of each spaced from its light output edge.

12. The illuminating device of claim 11 wherein each said sheet is J-shaped in cross-section.