Radiation detector with high thermal stability

Claim 2

A radiation detector comprising: an infrared radiation sensing device for receiving radiation from an external target; a thermally conductive duct thermally coupled to the sensing device, the duct passing radiation from the external target to the sensing device; and a thermally conductive shield surrounding but spaced from the duct and sensing device, the shield being thermally coupled to the duct at a location between the sensing device and an end of the duct directed toward the target.

Claim 3

A radiation detector as claimed in claim 1 wherein the sensing device is in an air space and is cantilevered on the duct from the shield.

Claim 4

A radiation detector as claimed in claim 2 wherein the duct is supported by the shield through a high thermal conductivity joint.

Claim 5

A radiation detector as claimed in claim 3 wherein the sensing device is suspended across an opening in a structure of high thermal conductivity material, the structure having a transparent window mounted in thermal contact therewith and the structure being supported by the conductive duct at an end opposite to the target.

Claim 6

A radiation detector as claimed in claim 4 further comprising a thermally conductive material axially positioned between the window and a rearwardly facing surface of the duct, the structure being pressed toward the rearwardly facing surface to compress the high conductivity material such that the conductance of the material is tuned to the detector to minimize the response of the sensing device to thermal perturbations from a distal end of the duct which is directed toward the target.

Claim 7

A radiation detector as claimed in claim 4 further comprising a temperature detector mounted to the high conductivity structure.

Claim 8

A radiation detector as claimed in claim 4 wherein the thermally conductive duct comprises a nonreflective inner surface.

Claim 9

A radiation detector as claimed in claim 1 wherein the sensing device is suspended across an opening in a structure of high thermal conductivity material, the structure having a transparent window mounted in thermal contact therewith and the structure being supported by the conductive duct at an end opposite to the target.

Claim 10

A radiation detector as claimed in claim 8 further comprising a thermally conductive material axially positioned between the window and a rearwardly facing surface of the duct, the structure being pressed toward the rearwardly facing surface to compress the high conductivity material such that the conductance of the material is tuned to the detector to minimize the response of the sensing device to thermal perturbations from a distal end of the duct directed toward the target.

Claim 11

A radiation detector as claimed in claim 1 wherein the thermal impedance through shielding, including the shield, is at least an order of magnitude less than the thermal impedance through an insulating space between the shielding and the conductive duct.

Claim 12

A radiation detector as claimed in claim 10 wherein the mass ratio of the shielding to the duct and a sensing device assembly is at least 10 to 1.

Claim 13

A radiation detector as claimed in claim 1 wherein the conductive duct is positioned within an extension shaped to be inserted into an ear.

Claim 14

A radiation detector as claimed in claim 12 wherein the sensing device is suspended across an opening in a structure of high thermal conductivity material, the structure having a transparent window mounted in thermal contact therewith and the structure being supported by the conductive duct at an end opposite to the target, the sensing device being in an air space and cantilevered on the duct from the shield, the duct being supported by the shield through a high thermal conductivity joint.

Claim 15

A radiation detector as claimed in claim 1 wherein the thermal impedance through shielding, including the shield, is at least an order of magnitude less than the thermal impedance through an insulating space between the shielding and the conductive duct and wherein the mass ratio of the shielding to the duct and sensing device assembly is at least 10 to 1.

Claim 16

A radiation detector as claimed in claim 14 further comprising a temperature detector mounted to a high conductivity structure to which the sensing device is mounted.

Claim 17

A radiation detector as claimed in claim 15 wherein the thermally conductive duct comprises a nonreflective inner surface.

Claim 18

A radiation detector as claimed in claim 16 wherein the extension is generally conical in shape with an included angle in the range of 20° to 60°.

Claim 19

A radiation detector as claimed in claim 17 having a field of view of about 30° or less.

Claim 20

A radiation detector as claimed in claim 1 further comprising thermally conductive material positioned between the sensing device and duct, the conductance of the material being tuned to the detector to minimize the response of the sensing device to thermal perturbations from a distal end of the duct which is directed toward the target.

Claim 21

A radiation detector as claimed in claim 1 further comprising an insulator surrounding the shield.

Claim 22

A temperature detector comprising: an extension shaped to be inserted into an ear; an elongated thermally conductive duct within the extension; a thermopile for receiving radiation from an external target through the conductive duct, the thermopile being suspended across an opening in a structure of high thermal conductivity material, the structure having a transparent window mounted in thermal contact therewith and the structure being supported by and in thermal contact with the conductive duct at an end opposite to the target; a temperature detector mounted to the rear of the high conductivity structure to provide a thermopile reference temperature; a thermally conductive shield surrounding and spaced from the duct and structure, the shield supporting the duct at a location between the structure and target, the structure being surrounded by an air space and cantilevered on the duct from the shield, the duct being supported by the shield through a high thermal conductivity joint; and an insulator surrounding the shield.

Claim 23

A temperature detector comprising: an extension shaped to be inserted into an ear; an elongated thermally conductive duct within the extension; a thermopile for receiving radiation from an external target through the conductive duct, the thermopile being suspended across an opening in a structure of high thermal conductivity material, the structure having a transparent window mounted in thermal contact therewith and the structure being supported by and in thermal contact with the conductive duct at an end opposite to the target; a temperature detector mounted to the rear of the high conductivity structure to provide a thermopile reference temperature; a thermally conductive shield surrounding and spaced from the duct and structure, the shield supporting the duct at a location between the structure and target, the structure being surrounded by an air space and cantilevered on the duct from the shield, the duct being supported by the shield through a high thermal conductivity joint; and an insulator surrounding the shield.

Claim 24

A temperature detector as claimed in claim 21 further comprising a thermally conductive material axially positioned between the window and a rearwardly facing surface of the duct, the structure being pressed toward the rearwardly facing surface to compress the high conductivity material such that the conductance of the material is tuned to the detector to minimize the response of the sensing device to thermal perturbations from a distal end of the duct.

Claim 27

A method as claimed in claim 23 wherein the step of monitoring comprises monitoring an audible indicator.

Claim 28

A method as claimed in claim 23 wherein the step of monitoring comprises monitoring a visual indicator.

Claim 29

A radiation detector comprising: an infrared radiation sensing device for receiving radiation from an external target, the sensing device comprises an active area influenced by radiation from an external target and a reference area, a thermally conductive duct thermally coupled to the sensing device, the duct passing radiation from the external target to the sensing device; and thermally conductive material positioned in the thermal path from a distal end of the duct, which is directed toward the target, to the sensing device, the conductance of the material being tuned to the detector to control the relative conductance of the respective thermal paths to the active area and reference area to minimize the response of the sensing device to thermal perturbations from the distal end of the duct.

Claim 30

A radiation detector comprising: an infrared radiation sensing device for receiving radiation from an external target, the sensing device comprises an active area influenced by radiation from an external target and a reference area, a thermally conductive duct thermally coupled to the sensing device, the duct passing radiation from the external target to the sensing device; and thermally conductive material positioned in the thermal path from a distal end of the duct, which is directed toward the target, to the sensing device, the conductance of the material being tuned to the detector to control the relative conductance of the respective thermal paths to the active area and reference area to minimize the response of the sensing device to thermal perturbations from the distal end of the duct.

Claim 31

A radiation detector as claimed in claim 26 wherein the material is tuned to the detector such that the sensing device response is less than about 0.1° for up to 20° of thermal perturbation at the distal end of the duct.

Claim 32

A radiation detector as claimed in claim 26 wherein the tuned thermally conductive material is positioned within a path from the duct to a hot junction of a thermopile.

Claim 33

A radiation detector as claimed in claim 28 wherein the tuned thermally conductive material is axially compressed.

Claim 34

A radiation detector as claimed in claim 29 wherein the tuned thermally conductive material is compressed against a window which covers the sensing device.

Claim 37

A method as claimed in claim 31 wherein the conductance is modified by applying an axial force to compress the thermally conductive material.

Claim 38

A radiation detector comprising: a header of high thermal conductivity material; an infrared radiation sensing device mounted to and thermally coupled to the header; a high thermal conductivity can surrounding the infrared radiation sensing device, the can being sealed to the header by high thermal conductivity epoxy; and a window closing the can.

Claim 39

A radiation detector comprising: a header of high thermal conductivity material; an infrared radiation sensing device mounted to and thermally coupled to the header; a high thermal conductivity can surrounding the infrared radiation sensing device, the can being sealed to the header by high thermal conductivity epoxy; and a window closing the can.

Claim 40

A radiation detector is claiming claim 33 further comprising a stack of high conductivity rings, the infrared radiation sensing device being mounted to the header through the high conductivity rings and the window being mounted to the high conductivity rings.

Claim 41

A radiation detector comprising: a header of high thermal conductivity material; a stack of high conductivity rings mounted to the header; an infrared radiation sensing device mounted to and thermally coupled to the header through the rings; a high thermal conductivity can surrounding the infrared radiation sensing device, the can being sealed to the header; and a window closing the can mounted to the high conductivity rings.

Claim 42

A radiation detector comprising: a header of high thermal conductivity material; a stack of high conductivity rings mounted to the header; an infrared radiation sensing device mounted to and thermally coupled to the header through the rings; a high thermal conductivity can surrounding the infrared radiation sensing device, the can being sealed to the header; and a window closing the can mounted to the high conductivity rings.