| 摘要 |
PROBLEM TO BE SOLVED: To detect a revolving angle with high accuracy by utilizing a signal generator means with comparatively low accuracy. SOLUTION: A frame of revolution in an X-ray CT (computed tomographic) apparatus is provided with an annular ring-shaped detector gear wheel 8, which is formed with a slit 8b on an inner circumferential face. The frame of revolution is revolved at a constant rate before tomography scanning, while under a game condition, an interval measuring timer 24 measures a pulse interval Tp of a detected signal S2, and a standard cycle calculator means 25 calculates a standard cycle Tr. A switch means 18 is switched to the (a) side, a correction coefficient calculator means 19 calculates a correction coefficient Kn which is a ratio of the standard cycle Tr to a detected cycle Tn, and stores the coefficient in a storage means 18. When tomography scanning, the switch means 18 is switched to the (b) side, a corrected cycle calculator means 20 determines a corrected cycle Trn by multiplying the detected cycle Tn by the correction coefficient Kn, and position signals SA, SB multiplied in order can be acquired based on the corrected cycle Trn. COPYRIGHT: (C)2003,JPO
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