The working process of the collimator

The collimator is an electromechanical optical device installed in front of the output window of the X-ray tube assembly sleeve. Its main function is to control the radiation field of the X-ray tube output line to meet the requirements of X-ray imaging and diagnosis. At the bottom, minimize the projection range to avoid unnecessary doses; and can absorb some scattered rays to improve the impact of clarity. In addition, it can also indicate the projection center and the size of the projection field. Therefore, the collimator is an indispensable auxiliary device for X-ray projection and protection.
Manual collimators are mainly used for photography. By manually adjusting the knob or pull rod on the collimator, the opening and closing activities of the wire shielding guide vane of the collimator can be realized. In addition to the above internal structure, there is also an irradiation field indicator system. It uses an indicator bulb to simulate the focus of the X-ray tube and replaces the X-rays with visible light, which is reflected by the reflector and hits the surface of the bed. The reflected visible light optical path is consistent with the optical path of X-rays after penetrating the reflector, so the size of the irradiation field can be indicated in advance. Since the service life of the indicator light is relatively short, the lighting of the indicator light is controlled by a button switch, which can be turned off by itself within 15s~1min. When the indoor brightness is high, some indicator lights will reach two brightness levels during their service life to meet the requirements of the lighting field. Some beam limiters are marked with the field size of the corresponding focal length around the knob or within the range of the lever. It is mainly used to preset the scene before the scene indicator lights up, so that it can be faster after the indicator lights up. Adjust the size of the illuminated area to extend the life of the indicator light.

Author:Lillian