SOLID STATE MULTI-COLOR SENSOR

• US 3,717,724 A
• Filed: 02/02/1971
• Issued: 02/20/1973
• Est. Priority Date: 02/02/1971
• Status: Expired due to Term

• Current Assignee: William E. Montgomery III
• Original Assignee: William E. Montgomery III
• Inventors: Montgomery, William E. III
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Stellar, George G.
• Application Number:
  US05/111,810
• Time in Patent Office: 749 Days
• Field of Search: 178/5.4R,5.4BD,5.4ST 307/311 317/235N 313/65AB,66,68R
• US Class Current: 348/272
• CPC Class Codes: H01J 29/451 with photosensitive junctions
• CPC Class Codes: H01J 31/46 Tubes in which electrical output represents both intensity and colour of image colour television cameras with only one tube H04N23/12

Abstract

A solid state sensor comprises multiple layers of semiconductor material having selectively wavelength absorption characteristics in accordance with predetermined regions of a spectrum to be detected. Arrays of contact elements provide selective connection to elemental areas of each layer and enable selective scanning of the elemental areas for deriving an output signal from each layer. Both electron beam scanning and electrical switching in a matrix-type scan are provided, permitting simultaneous derivation of multiple color output signals from the sensor. A specific application is a three color sensor for a color television camera.

Claims

1. A sensor responsive to an optical image of a given spectrum of illumination projected thereon, for producing electrical signals representative of that image in accordance with predetermined, corresponding wavelength regions of the spectrum, comprising:

a multi-layer semiconductor sandwich structure, each layer thereof comprising semiconducting material exhibiting selective absorption of a corresponding one of the predetermined wavelength regions of the spectrum, means defining and providing elemental image responsive areas in each of said layers, and electrically conductive means providing selective electrical connection to said elemental areas of each said layers for deriving an electrical signal from each said layer representing the intensity of illumination incident thereon in accordance with the image and for the corresponding wavelength region of the spectrum.

2. A sensor as recited in claim 1 wherein said means defining said elemental areas comprises a shadow mask positioned on the input side of said semiconductor structure.

3. A sensor as recited in claim 1 wherein said electrical conductive means comprise first and second arrays of plural contact elements respectively disposed on each said layer and defining a matrix with respect thereto, the effective matrix intersections of said contact elements of said first and second arrays corresponding to said elemental areas to provide selective electrical connection to each of said elements, for each of said layers.

4. A sensor as recited in claim 3 wherein said contact elements are vaporized material deposition.

5. A sensor as recited in claim 3 wherein each array of contact elements intermediate adjacent semiconductor layers provides one of said first and second arrays associated with each of said adjacent layers.

6. A sensor as recited in claim 1 for use as a color television sensor wherein said layers are responsive to respectively associated, predetermined wavelength regions of the visible spectrum corresponding to red, green, and blue colors.

7. A sensor as recited in claim 6 wherein:

said layer responsive to the red wavelength region comprises silicon.

8. A sensor as recited in claim 7 wherein one of said other Layers comprises cadmium sulfide doped to exhibit a peak spectral response in the blue wavelength region of the visible spectrum, and another of said other layers comprises cadmium sulfide doped to exhibit a peak spectral response in the green wavelength region of the visible spectrum.

9. A sensor as recited in claim 7 wherein:

said silicon layer comprises a mosaic of photodiodes defining the elemental image areas of said layer.

10. A sensor as recited in claim 9 wherein said photodiodes include a doped first surface thereof to establish P+ regions and a doped second surface thereof to establish respectively corresponding N+ regions.

11. A sensor as recited in claim 9 wherein said means defining said elemental areas of each of said layers further comprises a shadow mask having apertures therein positioned in alignment with said photodiodes of said silicon layer and defining in the others of said semiconductor layers elemental areas corresponding to and aligned with said photodiodes of said silicon layer.

12. A sensor as recited in claim 1 wherein said elemental areas of each layer are arranged in a plurality of rows and the corresponding areas of said plural rows are aligned in columns, and wherein said electrical connection means for each of said layers comprise:

a first array of plural contact elements on one surface of said layer, the elements thereof electrically interconnecting the areas of a corresponding row, and a second array of plural contact elements on the opposite surface of that same said layer, the elements thereof electrically interconnecting the areas of a corresponding column.

13. A sensor as recited in claim 12 wherein for each array positioned intermediate adjacent semiconductor layers, the contact elements thereof effect electrical interconnection of the corresponding areas the both of said layers.

14. A sensor as recited in claim 1 wherein one of said layers comprises silicon and said silicon and said silicon layer provides a substrate for for said other layers.

15. A sensor as recited in claim 14 wherein a mosaic of photodiodes are doped portions of said silicon layer to define the elemental areas thereof.

16. A sensor as recited in claim 15 wherein said photodiodes are N+ doped regions of the surface having deposited thereon the successive semiconductor layers and by P+ doped regions of the opposite, exposed surface of said silicon layer in respectively corresponding positions to the N+ doped regions.

17. A sensor as recited in claim 16 wherein said electrical connection means for the exposed surface of said silicon layer comprises conductive doped regions interconnecting said P+ doped regions.

18. Apparatus for generating color representative electrical signals for a color television system comprising:

a sensor including first, second, and third layers of semiconductor material having selective absorption characteristics and exhibiting peak spectral responses in the predetermined wavelength regions of three corresponding colors to be derived from incident illumination on said sensor, each of said layers in succession substantially absorbing the incident radiation of the associated predetermined wavelength region and substantially transmitting the radiation of other wavelength regions, said layers having defined therein corresponding elemental image areas, means providing selective electrical connection to the elemental image areas of each of said layers, and means for scanning said electrical contact means for selectively and sequentially addressing each of said elemental areas in each layer to derive from each of said layers an electrical output signal representative of the respectively associated wavelength region of the illumination incident on said sensor.

19. Apparatus as recited in claim 18 wherein one of said layers of said sensor comprises silicon semiconducting material doped to provide photodiodes therein defining the elemental areas.

20. Apparatus as recited in claim 19 wherein:

another of said layers of said sensor comprises cadmium sulfide doped to exhibit a peak spectral response in the green wavelength region of the visible spectrum, and a further of said semiconductor layers comprises cadmium sulfide doped to exhibit a peak spectral response in the blue wavelength region of the visible spectrum.

21. Apparatus as recited in claim 18 wherein said sensor further includes a shadow mask having a plurality of apertures therein corresponding to said elemental areas of said layers and affording thereby isolation between adjacent elemental areas of said semiconductor layers.

22. Apparatus as recited in claim 21 wherein:

said first layer of semiconducting material comprises silicon doped to provide photodiodes therein defining the elemental areas of said silicon layer, and said shadow mask defines the elemental areas of said second and third layers of semiconducting material.

23. Apparatus as recited in claim 18 wherein said scanning means comprises electrical switching means connected to said electrical contact means of said arrays.

24. Apparatus as recited in claim 23 wherein said switching means includes means for synchronized, simultaneous scanning of the corresponding elemental areas of said layers to produce simultaneous electrical output color signals therefrom.

25. Apparatus as recited in claim 24 wherein there is further provided processing means responsive to the electrical output signals derived from each of said layers for producing a color television output signal.

26. Apparatus for generating color representative electrical signals for a color television system comprising:

a sensor including first, second, and third layers of semiconductor material having selective absorption characteristics and exhibiting peak spectral responses in the predetermined wavelength regions of three corresponding colors to be derived from incident illumination on said sensor, each of said layers in succession substantially absorbing the incident radiation of the associated predetermined wavelength region and substantially transmitting the radiation of other wavelength regions, said layers having defined therein corresponding elemental image areas, means providing electrical connection to the elemental image areas of each of said layers, one of said layers comprising a mosaic of photodiodes defining the elemental areas of that layer and corresponding to the elemental areas of the others of said layers, electron beam scanning means for scanning said sensor in a scan raster corresponding to the elemental areas, said beam being directed to the exposed surface of said layer containing said photodiodes, and means for deriving from said electrical contact means electrical output signals from the corresponding layers.