Cold shield with redundancy prevention function and refrigeration type infrared detector

Abstract

The invention provides a cold shield with a redundancy prevention function, the cold shield comprises a cold shield body, a chip is arranged at the bottom in the cold shield body, a light blocking ring is mounted on the side wall in the cold shield body, an exhaust hole is formed in the side wall of the cold shield body, and the exhaust hole is located on the light blocking ring. The exhaust hole is provided with an object blocking structural part for preventing redundancy from entering the cold shield body. Thecold shield is simple in structure, by designing the exhaust holes with the object blocking structural parts, the function of exhausting gas in the cold screen can be achieved, the hole diameter of the micro porous structures of the object blocking structural parts can be adjusted, the redundancy of large-diameter particles can be prevented from entering the cold screen, and the problems of image abnormity and circuit short-circuit abnormity of the detector caused by the fact that the redundancy enters the cold shield in the prior art are effectively solved.

Description

technical field [0001] The invention belongs to the technical field of infrared detectors, and in particular relates to a cold screen and a cooling type infrared detector with the function of preventing redundant objects. Background technique [0002] Surplus refers to all substances other than those specified in the technical state of the product, including movable and immovable surplus. Non-movable excess within the detector dewar assembly also becomes movable during device shock or vibration. The existing Dewar structure needs to exhaust the cold shield Dewar and the gas inside the cold shield to maintain a vacuum environment, usually opening on the top or side wall of the cold shield, leaving a larger opening, usually ≥ 1mm 2 , but due to the existence of cold screen openings, it is easy to introduce large particle excess into the cold screen during the Dewar welding assembly process, surface treatment process, getter installation, and sheet bonding processes. When the...

AI Technical Summary

Problems solved by technology

The existing Dewar structure needs to exhaust the cold shield Dewar and the gas inside the cold shield to maintain a vacuum environment, usually opening on the top or side wall of the cold shield, leaving a larger opening, usually ≥ 1mm 2 , but due to the existence of cold screen openings, it is easy to introduce large particle excess into the cold screen during the Dewar welding assembly process, surface treatment process, getter installation, and sheet bonding process.

When these excesses enter the optical path of the device, that is, the Dewar cold shield structure, it may cause diffraction effects, which in turn affect the local light field distribution at the focal plane, resulting in "black spots" or "Poisson bright spots" on the image. Abnormal spots will seriously affect the extraction and analysis of target information by infrared detectors, and reduce the detector's ability to identify. Therefore, it is very necessary to study the optical diffraction phenomenon of redundant objects in the detector Dewar assembly and control the appearance of redundant objects.

In addition to the image anomalies described above, the excess can cause other product failure issues, such as signal crosstalk, larger particles that bridge discontinuous conductive parts in the device and short circuits, etc.

Images