Light emitting diode matrix

• US 4,394,600 A
• Filed: 01/29/1981
• Issued: 07/19/1983
• Est. Priority Date: 01/29/1981
• Status: Expired due to Term

• Current Assignee: L3 Technologies ESS, Inc. (L3Harris Technologies, Inc.)
• Original Assignee: Litton Systems Incorporated
• Inventors: Flannagan, Alfred
• Primary Examiner(s): LAROCHE, EUGENE
• Application Number:
  US06/229,489
• Time in Patent Office: 901 Days
• Field of Search: 313/500, 313/505, 313/510, 357/45
• US Class Current: 313/500
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 25/13 the devices being of a type provided for in group H01L33/00
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A matrix of light emitting diodes constructed of mosaic sectors each having a predetermined number of light emitting diodes, characterized by the cathode contacts of said diodes being outward, the cathodes being covered by conductors which have holes strategically placed so that the light emitted by said diodes is confined to small high intensity dots; said diodes having conductors positioned to connect to the anodes of said diodes and thermally connected to an anodized aluminum substrate which acts as a heat sink, the outer surface of said cathode conductors being blackened to absorb sunlight, and the exposed surface of said cathodes being nonreflective; a grid of optically and electrically insulative properties isolates and separates said diodes.

Claims

1. In a light emitting diode matrix, a substrate having, in order, first, second, third, and fourth adjacent edges;

a first plurality of light emitting diodes, each having an anode electrode centered on its anode end face and a plurality of cathode electrodes positioned around the periphery of its cathode end face, arranged in rows and columns of a rectangular coordinate system;

a second plurality of row conductors, equal in number to the number of rows of said diodes, each electrically contacting the anode electrodes of said diodes of its respective row;

a third plurality of column conductors, equal in number to the number of said columns of diodes, each electrically contacting the cathode electrodes of its respective column and thence extending over said first edge of said substrate;

said anodes and said row conductors being positioned upon a first surface of said substrate, with said anodes directed toward said substrate, with said column conductors contacting said cathode electrodes on the outer surface of said matrix and each having a fourth, equal to said second plurality of row conductors, plurality of openings formed therein and positioned over the non-electrode portions of the cathode surfaces of said diodes;

the improvement comprising;

said row conductors extending in rows along said first surface of said substrate, thence over said second edge of said substrate, thence extending in rows from said second edge on the second surface of said substrate, the positions of said row conductors on said second surface being contoured to turn through a right angle, and thence to said third edge of said substrate.

2. Apparatus as recited in claim 1 in which a heat sink is thermally attached on one surface thereof to at least said row conductors, including row and column driver electronics supported on said heat sink;

the improvement further comprising;

said row conductors and said column conductors being attached to opposite edges of said heat sink and thence to said row and column driver electronics, respectively.

3. Apparatus as recited in claim 1, the improvement further comprising:

a light absorbing coating on the outer surface of said column conductors, and an anti-reflective coating over at least the exposed cathode surfaces of said diodes.

4. Apparatus as recited in claim 3 in which the improvement further comprises:

the side surfaces of the individual said diodes are electrically and optically isolated by an opaque and electrically insulative grid.