Variable size light sensor element

• US 5,567,971 A
• Filed: 06/07/1995
• Issued: 10/22/1996
• Est. Priority Date: 06/07/1995
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Biegelsen, David K., Jackson, Warren B.
• Primary Examiner(s): Prenty, Mark V.
• Application Number:
  US08/479,874
• Time in Patent Office: 503 Days
• Field of Search: 257/431, 257/443, 257/444, 257/461, 257/462, 257/53
• US Class Current: 257/431
• CPC Class Codes: H01L 27/14665 Imagers using a photoconductor layer

Abstract

A sensor array includes includes multiple sensor elements that each have a collection electrode in contact with a photosensitive layer. The photosensitive layer is configured to produce a detectable response at the collection electrode upon incidence of radiation in a responsive zone of the photosensitive layer. A gate electrode layer is separated from the photosensitive layer by a dielectric layer, with adjustments to voltage applied to the gate electrode layer inducing changes in areal extent of the responsive zone of the photosensitive layer. Changing the size of the responsive zone permits performance of image convolutions for edge detection, data compression, or other Gaussian convolutions by the sensor array, rather than by post-detection electronics.

Claims

1. A sensor element comprising

a collection electrode,

a radiation sensor in contact with the collection electrode, the radiation sensor configured to produce a detectable response at the collection electrode upon incidence of radiation in a responsive zone, and

a gate electrode layer separated from the radiation sensor by a dielectric layer, with adjustments to voltage applied to the gate electrode layer inducing changes in areal extent of the responsive zone of the radiation sensor.

2. The sensor element of claim 1, wherein the radiation sensor is a layered semiconductor further comprising an n+doped layer and a p+doped layer.

3. The sensor element of claim 2, wherein the layered semiconductor of the radiation sensor further comprises an intrinsic amorphous silicon layer positioned between the n+doped layer and the p+doped layer to form a p-i-n diode.

4. The sensor element of claim 1, further comprising a data line and a pass transistor connected to receive charge from the collection electrode for controlled passing of charge to the data line.

5. The sensor element of claim 4, wherein the pass transistor has a drain connected to the collection electrode, a source connected to the data line and separated from the drain, and a pass transistor gate electrode controllable to promote passage of charge from the drain to the source.

6. The sensor element of claim 4, wherein the collection electrode is a pass transistor gate electrode in electrical contact with the radiation sensor, the pass transistor gate electrode being responsive to photogenerated charge from the radiation sensor to control current passing between a drain and a source.

7. A sensor element array comprising

a plurality of collection electrodes,

a radiation sensor in electrical contact with the collection electrodes, the radiation sensor configured to produce a detectable response at each of the collection electrodes upon incidence of radiation in a responsive zone associated with each of the respective collection electrodes, and

a gate electrode separated from the radiation sensor by a dielectric layer, with adjustments to voltage applied to the gate electrode inducing changes in areal extent of the respective responsive zones associated with each of the collection electrodes in electrical contact with the radiation sensor layer.

8. The sensor element of claim 7, wherein the radiation sensor further comprises a continuously extending semiconductive layer that generates charge in response to incident radiation.

9. A sensor element comprising

a radiation sensitive layer configured to produce a detectable response upon incidence of radiation in a responsive zone, and

a semiconductor layer positioned adjacent to the radiation sensitive layer and arranged to induce changes in areal extent of the responsive zone of the radiation sensitive layer in response to change in voltage bias applied to the semiconductor layer.

10. The sensor element of claim 9, further comprising a dielectric layer positioned between the radiation sensitive layer and the semiconductor layer.

11. The sensor element of claim 9, further comprising a plurality of collection electrodes in electrical contact with the radiation sensitive layer.