| 摘要 |
PURPOSE:To simplify a device by locating a reference position and judging whether or not step-out of a stepping motor has occurred, with a single optical scanning system entry detecting means, in the drive control of an optical scanning system. CONSTITUTION:A single BL sensor 12 which becomes ON by the entry of an indication flag 13 fixed to the scanner 6 of a picture image reader is provided for the positioning of the scanner 6. The position where the output signal of the BL sensor 12 changes from ON to OFF is the home position of the scanner 6. And, positions for READ START, READ END, RETURN, etc., are controlled by the count of the drive pulse. As the output signal of the BL sensor 12 becomes ON by an abnormal count of the drive pulse, step-out of a stepping motor 3 can be detected. In this way, it becomes possible to control positions and detect step-out with a single BL sensor. |
