Patent ID: 7486767

Claim:
An X-ray apparatus comprising: a fixed frame having first and second guide members; a translating frame supported by the first guide member, capable of being translated relative to the fixed frame along a predetermined direction; a revolving arm supported by the translating frame, capable of revolving around a vertical revolution axis; a guide plate secured on the second guide member of the fixed frame; a driving mechanism for revolving the revolving arm around the vertical revolution axis; a clock pulse generator for generating clock pulse signals; drive change detecting means for detecting the clock pulse signals in ON/OFF durations which appear alternately and synchronously with the driving of the driving mechanism so as to detect the amount of the drive change of the driving mechanism; the revolving arm having a vertical rod provided at an eccentric position spaced from the vertical revolution axis by a predetermined distance; and the guide plate having a guide slot extending in a direction substantially traverse to the predetermined direction, for receiving the vertical rod therethrough; wherein revolution of the revolving arm around the vertical revolution axis causes the vertical rod to move along the guide slot, thereby horizontally translating the revolving arm relative to the fixed frame; and wherein revolution of the revolving arm by the driving mechanism is terminated when the amount of the drive change is beyond a predetermined range of threshold values.