Cryogenic cooler off-axis drive mechanism for an infrared receiver

Claim 1

In an infrared receiver including an infrared detector in a scanning path for infrared energy emanating from a source thereof for producing electrical signals representative of impinging infrared energy; an electro-optical system coupled to the detector for processing video signals from the electrical signals produced by the detector; and a refrigerator for cooling the detector to an operating temperature, the refrigerator having a cooling member including a cylinder, a regenerator-displacer reciprocally mounted in the cylinder, and a cold chamber formed between an end of the cylinder and the regenerator-displacer, a housing enclosing a cylinder-piston type compressor motor and drive mechanism and a passage means iNterconnecting the compressor cylinder, regenerator-displacer, and cold chamber of the cooling member, said compressor cylinder, passage, regenerator-displacer, and cold chamber forming the working volume for a cryogen, the improvement comprising an off-axis drive means mounted in the housing exteriorly of the cold member and compressor cylinder to allow the compressor cylinder and piston to be matched in size with the regenerator-displacer for increased refrigerator efficiency, said off-axis drive mechanism interconnecting the regenerator-displacer of the cold member and the compressor piston to the motor, whereby the motor actuates the off-axis drive mechanism to sequentially reciprocate the regenerator-displacer and the compressor piston for circulating the cryogen throughout the working volume.