| 摘要 |
PURPOSE: To provide a simple means correcting the position of a fan beam on a real-time basis in response to the effect of the environment such as rotary stress and thermal expansion and generating the z-axis position signal. CONSTITUTION: This computer tomographic device is provided with a detector detecting the position of the z-axis on the plane of the fan beam 22 of the computer tomographic device against a detector array 14, it uses a pair of slotted masks on independent detection cells 18, and the slot has the exposed width increased or decreased along the longitudinal direction. The intensity signals from two masked detection cells 18 are subtracted to generate the x-axis position signal, and the action of a dark current is removed. Many cells are combined to reduce the effect of the sensitivity fluctuation between detection cell pairs. The z-axis position of the fan beam 22 against the detector array 14 is controlled with the z-axis position signal, and the effect of the sensitivity fluctuation of the detection cells 18 is reduced. |
