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US 4,791,298 AGranted
Infrared detectors
AssigneeU.S. Philips Corporation
InventorsWilliam A. E. Dunn, David J. Gowlett
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AssigneeU.S. Philips Corporation
InventorsWilliam A. E. Dunn, David J. Gowlett
Estimating the term…
An infrared detector has an infrared detector element (2) mounted at a first part (11) of a housing (1), a Joule-Thomson cooling element (3) accommodated in a second part (12), and an infrared transmissive window (15) at the front of the housing (1). A compact, space-saving and light weight structure with improved optical efficiency is obtained. The core of the Joule-Thomson cooling element (3) forms a third part (13) of the housing (1), and these second and third parts (12 and 13) of the housing extend towards the front of the detector. The cooler core (13) which may carry a cooled filter (25) has a hollow shape or is otherwise infrared transmissive in front of the detector element (2) and can direct incident radiation (50) towards the detector element (2). For this purpose the inner surface of the hollow core (13) may carry a reflective conductor pattern (18,19) which also provides electrical connections for the detector element (2). This core part (13) may seal a channel in a grooved intermediate member (48 in FIG. 3) between the second and third housing parts (12 and 13) so as to form the Joule-Thomson cooling element (3) without requiring conventional finned metal tubing (31 in FIG. 1).
An infrared detector comprising a housing, at least one infrared detector element mounted at a first part of the housing, a Joule-Thomson cooling element formed around a core and accommodated in a second part of the housing, which cooling element serves to effect cooling of the detector element during operation of the detector by expansion of coolant into a space adjacent the first part of the housing, and infrared transmissive means at a front of the housing to permit transmission of infrared radiation to the detector element, characterized in that the core of the Joule-Thomson cooling element forms a third part of the housing, that the second and third parts of the housing extend from the first part of the housing towards the front of the housing, and that the third part of the housing is infrared transmissive in front of the detector element to permit transmission of the infrared radiation through the core of the Joule-Thomson cooling element, from the front of the housing to the infrared detector element.
An infrared detector comprising:
Dependencies are inferred from the claim text.