According to the driving method of the opening and closing of the lead leaves of the collimator, the collimator can be divided into the following types:
1. Manual collimator: The manual beam limiter is mostly used in photography. The opening and closing activities of this type of collimator cover lead are achieved by manually adjusting the knob or lever on the collimator. In addition to the aforementioned internal structure, it also has an irradiation field indication system.
2. Electric collimator: The electric collimator is mostly used in fluoroscopy, which is convenient for remote control and is an indispensable component for the remote control of gastrointestinal bed. The opening and closing of the lead beam of the electric collimator is generally driven by a micro DC motor, and the forward rotation, reverse rotation and operation time of the DC motor are appropriately controlled, and the irradiation field can be adjusted to the required size.
3. Fully automatic collimator: The structure of the automatic collimator is not much different from that of the electric collimator. The difference is that the automatic collimator is equipped with a state monitoring device for lead leaves. With the change of focal screen distance in function, the automatic collimator has the ability to automatically maintain the size of its irradiation field, which is mostly used for perspective.