Dewar coldfinger
US4918312A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 23, 1988 |
| Grant date | Apr 17, 1990 |
| Priority date | — |
| Expiry date | Nov 23, 2008 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF17C2270/0509
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An infrared detector assembly (10) of the type used in munitions and night vision systems having improved coldfinger dewar tube (22). Such detectors include a tubular coldfinger which is surrounded by a vacuum and has a cold end (24) which supports the infrared detector array (30) and related components, and an opposite warm end (26). In accordance with this invention, the coldfinger tube is a two-material composite structure having plastic (44) and metal (42) layers. The plastic layer provides the necessary bending stiffness to support the cold end components while minimizing heat transfer rate between the warm and cold ends of the tube. The metal film layer provides a gas seal to preserve the integrity of the dewar vacuum, but is sufficiently thin to provide a minimal increase in thermal conductivity. The compositie coldfinger tube in accordance with this invention features lower overall heat conductivity thus minimizing cryogenic cooling requirements while providing the necessary bending stiffness. Due to the reduction in thermal capacitance provided by this assembly, the cool-down time for the cold end components can also be minimized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.