Thick film sensor and infrared detector

Claim 2

A temperature sensor comprising: a self-supporting film of an oxidic material having a high temperature coefficient of resistance; a pair of fired-on conductive electrodes in the form of closely-spaced, parallel interdigitated fingers on a first major surface of said film; a third electrode of low thermal mass substantially covering the other major surface of said film; and means for connecting said three electrodes into a circuit.

Claim 3

The sensor as claimed in claim 1, wherein said film is cobalt oxide.

Claim 4

The sensor as claimed in claim 1, wherein said interdigitated electrode pair is a thick film conductor selected from the group consisting of gold, palladium, platinum and mixtures and alloys thereof.

Claim 5

The sensor as claimed in claim 1, wherein said third electrode is colloidal graphite.

Claim 6

The sensor as claimed in claim 1, wherein said electrode pair includes busses connecting said interdigitated fingers and said connecting means comprise bonding pads.

Claim 7

A detector for moving radiant objects comprising: a thermal sensor; an enclosure containing said sensor; and means for connecting said sensor into a circuit; said sensor comprising: a self-supporting film of an oxidic material having a high temperature coefficient of resistance; a pair of fired-on conductive electrodes in the form of closely-spaced, parallel interdigitated fingers on a first major surface of said film; a third electrode of low thermal mass substantially covering the other major surface of said film; said enclosure retaining said sensor in a fixed, spaced and parallel relation with one wall thereof; said third electrode facing said one wall; an elongated narrow opening in said one wall, said opening being parallel to said interdigitated fingers of said electrode pair; and said connecting means comprising conductive leads connected to said three electrodes.

Claim 8

A detector for moving radiant objects comprising: a thermal sensor; an enclosure containing said sensor; and means for connecting said sensor into a circuit; said sensor comprising: a self-supporting film of an oxidic material having a high temperature coefficient of resistance; a pair of fired-on conductive electrodes in the form of closely-spaced, parallel interdigitated fingers on a first major surface of said film; a third electrode of low thermal mass substantially covering the other major surface of said film; said enclosure retaining said sensor in a fixed, spaced and parallel relation with one wall thereof; said third electrode facing said one wall; an elongated narrow opening in said one wall, said opening being parallel to said interdigitated fingers of said electrode pair; and said connecting means comprising conductive leads connected to said three electrodes.

Claim 9

The detector as claimed in claim 6, wherein said film is cobalt oxide.

Claim 10

The detector as claimed in claim 6, wherein said interdigitated electrode pair is a thick film conductor selected from the group consisting of gold, palladium, platinum and mixtures and alloys thereof.

Claim 11

The detector as claimed in claim 6 wherein said third electrode is colloidal graphite.

Claim 12

The detector as claimed in claim 6, wherein said enclosure comprises: an insulating substrate having said electrode pair bonded thereto; leads passing through said substrate connected to said three electrodes. an enclosing can including said opening bonded to said substrate.

Claim 13

A detector system for moving radiant object comprising: a sensor comprising a first pair of radiation-sensitive film-type oxide resistors having a pair of electrodes on a first major surface and a third electrode forming a common terminal on the other major surface; an enclosure for said sensor including an opening spaced from said sensor and defining a field of view therefor; a bridge circuit including said pair of resistors as one half thereof and another pair of substantially identical resistors as the other half thereof, said other pair being isolated from incident radiation from said field of view; and said bridge circuit also including detector means capable of detecting sinusoidal variation in resistance of said first pair of resistors.

Claim 14

A detector system for moving radiant object comprising: a sensor comprising a first pair of radiation-sensitive film-type oxide resistors having a pair of electrodes on a first major surface and a third electrode forming a common terminal on the other major surface; an enclosure for said sensor including an opening spaced from said sensor and defining a field of view therefor; a bridge circuit including said pair of resistors as one half thereof and another pair of substantially identical resistors as the other half thereof, said other pair being isolated from incident radiation from said field of view; and said bridge circuit also including detector means capable of detecting sinusoidal variation in resistance of said first pair of resistors.

Claim 15

The detector system as claimed in claim 11, wherein said other pair of resistors are thermally heat-sinked to said first pair, whereby all said resistors are maintained at the ambient temperature.

Claim 16

The detector system as claimed in claim 11, wherein said sensor comprises: a self-supporting film of an oxidic material having a high temperature coefficient of resistance; a pair of fired-on conductive electrodes in the form of closely-spaced, parallel interdigitated fingers on said first major surface of said film; said third electrode being of low thermal mass and substantially covering said other major surface of said film; said third electrode facing said opening within said enclosure.

Claim 17

The detector system as claimed in claim 13, wherein said opening is a slit parallel with said interdigitated electrode fingers, a moving radiant object across said field of view generating an alternating current for said detector means.

Claim 18

The detector system as claimed in claim 13, wherein said film is cobalt oxide.

Claim 19

The detector system as claimed in claim 13, wherein said interdigitated electrode pair is a thick film conductor selected from the group consisting of gold, palladium, platinum and mixtures and alloys thereof.

Claim 20

The detector system as claimed in claim 13, wherein said third electrode is colloidal graphite.