Infrared radiation imaging array with compound sensors forming each pixel

• US 5,449,910 A
• Filed: 11/17/1993
• Issued: 09/12/1995
• Est. Priority Date: 11/17/1993
• Status: Expired due to Term

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Rhodes, Michael L., Wood, Roland A., Higashi, Robert E.
• Primary Examiner(s): Hannaher, Constantine
• Application Number:
  US08/153,066
• Time in Patent Office: 664 Days
• Field of Search: 250/338.4, 250/338.1
• US Class Current: 250/338.1
• CPC Class Codes: H10N 19/00 Integrated devices, or assemblies of multiple devices, comprising at least one thermoelectric or thermomagnetic element covered by groups H10N10/00 - H10N15/00

Abstract

An infrared imaging array of thermoelectric sensors has a plurality of electrically connected microbridge subsensors comprising each sensor of the array. Each subsensor consists of a short span microbridge lying across a relatively small pit. The use of many of such subsensors for each sensor rather than a single large area microbridge sensor for a single pixel allows each pixel to be made large enough to give good sensitivity in either vacuum or gas-filled designs, and at the same time avoid the reduced fabrication yield which results when sensors span large pits.

Claims

1. An infrared radiation sensing array comprising

a) a substrate having on a first surface, a plurality of pixel areas, a plurality of pixel areas arranged in an array;

b) within each pixel area, a sensor comprising a plurality of infrared sensitive microbridge subsensors arranged in a sub-array, each subsensor spanning an underlying pit and having first and second output terminals across which appears a voltage responsive to presence of infrared radiation impinging on a radiation-responsive surface of the subsensor, at least one of said subsensors within a pixel area having its radiation-responsive surface facing away from the pit within the pixel area;

c) within each pixel area, a plurality of subsensor conductors electrically connecting the subsensors in that pixel area together in a predetermined manner which provides a composite signal to which each subsensor contributes electrical energy; and

d) a plurality of sensor output conductors, each one associated with a single sensor, and carrying the composite signal produced by that sensor.

2. The array of claim 1, wherein the conductors within a pixel area connect at least two subsensors within that pixel area in series connection with each other.

3. The array of claim 2, wherein each subsensor includes a sensing junction and a reference junction, and wherein the conductors forming the series connection between two subsensors are integral with the elements forming the reference junction of one series-connected subsensor and the sensing junction of another series-connected subsensor.

4. The array of claim 1, wherein the conductors within a pixel area connect at least some of the subsensors within that pixel area in parallel connection with each other.

5. The array of claim 1, including a signal processor connected to the sensor output conductors.