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US3947840A Expired / Lapsed US ⏱️ 0.0 years remaining

Integrated semiconductor light-emitting display array

Assignee: Monsanto Co
•
Filing: 1974-08-16
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Granted: 1976-03-30
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Expires: 1994-08-16
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Abstract

Abstract An integrated LED display array wherein light is emitted and observed through a light-transmissive substrate, i.e., single crystal, which carries a plurality of optically isolated LED assemblies. Scattering of light from individual assemblies is prevented by an optically absorbing doped region which optically isolates each assembly. Light is generated at the back of the single crystal and viewed through the crystal. The LED assemblies, preferably multicolor, are directly mated to energizing electronic circuitry, e.g., a monolithic integrated circuit, via appropriate interconnections sandwiched between the two. The energizing electronic circuitry comprise an array of circuit elements which provide the energizing currents for respective ones of the LED assemblies.

Inventors

  • 👤 Magnus George Craford
  • 👤 Paul T. Bailey

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 20:17
CPC Classifications
H; H10; H10D; H10D99/00; G; G09; G09G; G09G3/00; G09G3/20; G09G3/22; G09G3/30; G09G3/32; H10H; H10H20/00; H10H20/80; H10W; H10W72/00; H10W72/20; H10W90/00; H10W90/701; H10W90/721; H10W90/724; Y; Y10; Y10S; Y10S148/00; Y10S148/038; Y10S148/065; Y10S148/072; Y10S148/099; Y10S148/119

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 240 words
A composite integrated circuit LED display array comprising: a light-transmissive monolithic planar substrate of a single III-V crystal including a plurality of LED devices carried in the body of said substrate and forming an array of LED devices, each of said LED devices being adapted when energized to emit light at the back surface of said substrate, said LED devices being optically isolated from one another, the optical isolation being affected by a light-absorbing doped region between said LED devices, said doped region being adapted to absorb light emitted by the individual LED devices, each of said LED devices being constituted by at least one diode having a separate p-n junction at which said light is radiated, said junction being at the back surface of said crystal, said light being transmitted through said crystal for being observed at the front surface of said crystal; a monolithic integrated circuit array of circuit elements corresponding to and adapted for energizing respective ones of said LED devices, said integrated circuit array being adjacent the back surface of said crystal; and interconnection means sandwiched between said arrays for providing electrical interconnections between respective ones of said LED devices and circuit elements at said back surface, said circuit elements being selectively operable for independently energizing corresponding ones of said LED devices to emit light at said back surface, said light being transmitted through said substrate for being observed at the front surface of said substrate.
Claim 2
Dependent Claim 240 words
A composite integrated circuit LED display array comprising: a light-transmissive monolithic planar substrate of a single III-V crystal including a plurality of LED devices carried in the body of said substrate and forming an array of LED devices, each of said LED devices being adapted when energized to emit light at the back surface of said substrate, said LED devices being optically isolated from one another, the optical isolation being affected by a light-absorbing doped region between said LED devices, said doped region being adapted to absorb light emitted by the individual LED devices, each of said LED devices being constituted by at least one diode having a separate p-n junction at which said light is radiated, said junction being at the back surface of said crystal, said light being transmitted through said crystal for being observed at the front surface of said crystal; a monolithic integrated circuit array of circuit elements corresponding to and adapted for energizing respective ones of said LED devices, said integrated circuit array being adjacent the back surface of said crystal; and interconnection means sandwiched between said arrays for providing electrical interconnections between respective ones of said LED devices and circuit elements at said back surface, said circuit elements being selectively operable for independently energizing corresponding ones of said LED devices to emit light at said back surface, said light being transmitted through said substrate for being observed at the front surface of said substrate.
Claim 3
Dependent Claim 19 words
A composite LED display array as set forth in claim 1 wherein said substrate is a monocrystalline III/V compound.
Claim 4
Dependent Claim 25 words
A composite LED display array as set forth in claim 2 wherein said substrate comprises a monolithic crystal of GaP doped to have n-type conductivity.
Claim 5
Dependent Claim 20 words
A composite LED display array as set forth in claim 3 wherein said GaP is doped with Te or Se.
Claim 6
Dependent Claim 30 words
A composite LED display array as set forth in claim 3 wherein said LED devices are formed in a single crystal nitrogen-doped GaP epitaxial layer on said substrate of GaP.
Claim 7
Dependent Claim 34 words
A composite LED display array as set forth in claim 5 wherein said LED devices are adapted to emit light of a plurality of colors, there being at least one LED for each color.
Claim 8
Dependent Claim 35 words
A composite LED display array as set forth in claim 6 wherein said LED devices comprise a plurality of LED assemblies, each assembly comprising at least one green LED and at least one red LED.
Claim 9
Dependent Claim 37 words
A composite LED display array as set forth in claim 7 wherein the red LED comprises a p-n junction formed by a zinc and oxygen doped GaP area at the surface of said nitrogen-doped GaP epitaxial layer.
Claim 10
Dependent Claim 25 words
A composite LED display array as set forth in claim 8 wherein each LED assembly comprises a central red LED flanked by a green LED.
Claim 11
Dependent Claim 36 words
A composite LED display array as set forth in claim 9 wherein the green LED comprises a zinc diffusion area on each side of the red LED at the surface of said nitrogen-doped GaP epitaxial layer.
Claim 12
Dependent Claim 35 words
A composite LED display array as set forth in claim 2 wherein said light-absorbing doped region is characterized by zinc doping having a concentration greater than 10 18 atoms/cc but less than 10 20 atoms/cc.
Claim 13
Dependent Claim 20 words
A composite LED display array as set forth in claim 1 wherein said light-absorbing doped region extends through said substrate.
Claim 14
Dependent Claim 23 words
A composite LED display array as set forth in claim 1 wherein said doped region comprises a metal selected from atomic group II.
Claim 15
Dependent Claim 29 words
A composite LED display array as set forth in claim 13 wherein the group II metal is zinc and is doped to a concentration greater than 10 18 atoms/cc.
Claim 16
Dependent Claim 191 words
A composite integrated circuit LED display array comprising: a light-transmissive planar substrate of a single III-V crystal carrying on the back side thereof of a plurality of optically isolated LED devices, the optical isolation being effected by a light-absorbing doped region between individual LED devices, said doped region being adapted to absorb light emitted by the individual LED devices, each of said LED devices being constituted by at least one diode having a separate p-n junction at which said light is radiated, said junction being at the back surface of said crystal, said light being transmitted through said crystal for being observed at the front surface of said crystal; and a planar integrated circuit array comprising memory and drive circuit elements corresponding to respective ones of said LED devices, said integrated circuit array being integrally joined to said light-transmissive substrate at the back side of said crystal, said memory circuit elements being selectively addressable to cause said drive circuit elements to independently energize the respective LED devices to emit light at said back surface, said light being transmitted through said substrate for being observed at the front surface of said substrate.
Claim 17
Dependent Claim 191 words
A composite integrated circuit LED display array comprising: a light-transmissive planar substrate of a single III-V crystal carrying on the back side thereof of a plurality of optically isolated LED devices, the optical isolation being effected by a light-absorbing doped region between individual LED devices, said doped region being adapted to absorb light emitted by the individual LED devices, each of said LED devices being constituted by at least one diode having a separate p-n junction at which said light is radiated, said junction being at the back surface of said crystal, said light being transmitted through said crystal for being observed at the front surface of said crystal; and a planar integrated circuit array comprising memory and drive circuit elements corresponding to respective ones of said LED devices, said integrated circuit array being integrally joined to said light-transmissive substrate at the back side of said crystal, said memory circuit elements being selectively addressable to cause said drive circuit elements to independently energize the respective LED devices to emit light at said back surface, said light being transmitted through said substrate for being observed at the front surface of said substrate.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-03-30 1979-09-29 1980-03-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-03-30 1983-09-29 1984-03-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-03-30 1987-09-29 1988-03-30 $7700.00 Window Closed / Lapsed

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