Photoelectronic diode spatial light modulator and eye protection goggles incorporating the same

• US 4,978,208 A
• Filed: 07/24/1989
• Issued: 12/18/1990
• Est. Priority Date: 07/24/1989
• Status: Expired due to Term

• Current Assignee: Hughes Electronics Corporation (AT&T, Inc.)
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Wu, Shin-Tson, Hsu, Tsung-Yuan, Loo, Robert Y.
• Primary Examiner(s): Bovernick, Rodney B.
• Application Number:
  US07/383,698
• Time in Patent Office: 512 Days
• Field of Search: 2/8, 2/432, 330/4.3, 340/760, 350/336, 350/342, 350/353, 350/354, 350/355, 350/356, 350/331 R, 350/448, 350/451, 350/452, 351/44, 351/45, 351/46, 362/800, 430/84, 430/95
• US Class Current: 351/45
• CPC Class Codes: A61F 9/023 with variable transmission, e.g. photochromic for welding A61F9/067
• CPC Class Codes: H01L 31/143 the light source being a semiconductor device with at least one potential-jump barrier or surface barrier, e.g. light emitting diode
• CPC Class Codes: H01L 31/153 formed in, or on, a common substrate

Abstract

A spatial light modulator includes a photosensor diode and a photoemitting diode array, each having two semiconductive layers of opposite electrical polarities, and which are sandwiched together with layers of the same polarity (P or N) in electrical contact with each other. Transparent electrode layers are formed on the opposite surfaces of the photosensor diode and photoemitting diode array respectively, in electrical contact with the layers of the opposite polarity. The individual photoemitting diodes are electrically and optically isolated from each other. With a voltage applied across the electrodes which causes the photosensor diode to be reverse biased and the photoemitting diodes to be forward biased, the photoemitting diode array generates a visual display which is a reproduction of a light image incident on the photosensor diode. The photosensor diode may be replaced by a single layer of a photoconductive material. Two of the spatial light modulators may be combined in a frame with suitable optics to provide eye protection goggles.

Claims

1. A spatial light modulator comprising:

a photoconductive member;

a photoemitting diode array including a plurality of photoemitting diodes which are electrically and optically isolated from each other and electrically connected to respective sections of the photoconductive member; and

first and second transparent electrodes which sandwich the photoconductive member and photoemitting diode array therebetween and are electrically connected thereto respectively.

2. A spatial light modulator as in claim 1, in which the photoemitting diodes comprise light emitting diodes.

3. A spatial light modulator as in claim 1, in which the photoemitting diodes comprise laser diodes.

4. A spatial light modulator as in claim 1, further comprising an electrically conductive adhesive for adhering the photoconductive member and photoemitting diode array together and electrically interconnecting the respective sections of the photoconductive member and photoemitting diodes.

5. A spatial light modulator as in claim 1, further comprising a substrate for supporting the photoconductive member and photoemitting diode array, at least one of the substrate, photoconductive member and photoemitting diode array being optically opaque.

6. A spatial light modulator as in claim 1, in which the photoemitting diode array and respective sections of the photoconductive member are two dimensional.

7. A spatial light modulator as in claim 1, further comprising barrier means for electrically and optically isolating the photoemitting diodes from each other.

8. A spatial light modulator as in claim 7, in which the barrier means comprises grooves formed in the photoemitting diode array between adjacent photoemitting diodes.

9. A spatial light modulator as in claim 7, in which the barrier means comprises insulative regions formed in the photoemitting diode array between adjacent photoemitting diodes.

10. A spatial light modulator as in claim 7, in which the barrier means comprises insulative regions formed by proton implantation in the photoemitting diode array between adjacent photoemitting diodes.

11. A spatial light modulator as in claim 1, further comprising a substrate, the photoconductive member and photoemitting diode array being constituted by semiconductive layers formed on the substrate.

12. A spatial light modulator as in claim 1, further comprising optical means for forming a light image on the photoconductive member.

13. A spatial light modulator as in claim 1, further comprising optical means for forming a light image of the photoemitting diode array.

14. A spatial light modulator as in claim 1, further comprising power source means for applying an electrical potential across the first and second electrodes such that the photoemitting diodes are forward biased.

15. A spatial light modulator as in claim 1, in which the photoconductive member comprises a photosensor diode, the photoemitting diodes being electrically connected to the respective sections of the photosensor diode such that regions of the respective sections of the photosensor diode and photoemitting diodes having a first electrical polarity are connected together;

the first and second electrodes being electrically connected to regions of the photosensor diode and photoemitting diodes respectively having a second polarity which is opposite to the first polarity.

16. A spatial light modulator as in claim 15, further comprising power source means for applying an electrical potential across the first and second electrodes such that the photosensor diode is reverse biased and the photoemitting diodes are forward biased.

17. Eye protection goggles, including frame means, and at least one opaque eyepiece means supported by the frame means, each of said at least one eyepiece means comprising:

a photoconductive member;

a photoemitting diode array including a plurality of photoemitting diodes which are electrically and optically isolated from each other and electrically connected to respective sections of the photoconductive member; and

first and second transparent electrodes which sandwich the photoconductive member and photoemitting diode array therebetween and are electrically connected thereto respectively.

18. Eye protection goggles as in claim 17, further comprising power source means for applying an electrical potential across the first and second electrodes of said at least one eyepiece means such that the photoemitting diodes are forward biased.

19. Eye protection goggles as in claim 17, in which said at least one eyepiece means further comprises optical means for forming a light image on the photoconductive member.

20. Eye protection goggles as in claim 17, in which said at least one eyepiece means further comprises optical means for forming a light image of the photoemitting diode array.

21. Eye protection goggles as in claim 17, in which said at least one eyepiece means further comprises image intensification means for intensifying an image of the photoemitting diode array.

22. Eye protection goggles as in claim 17, in which photoconductive member of said at least one eyepiece means comprises a photosensor diode, the photoemitting diodes being electrically connected to the respective sections of the photosensor diode such that regions of the respective sections of the photosensor diode and photoemitting diodes having a first electrical polarity are connected together;

the first and second electrodes being electrically connected to regions of the photosensor diode and photoemitting diodes respectively having a second polarity which is opposite to the first polarity.

23. Eye protection goggles as in claim 22, further comprising power source means for applying an electrical potential across the first and second electrodes of said at least one eyepiece means such that the photosensor diode is reverse biased and the photoemitting diodes are forward biased.