| 摘要 |
PURPOSE:To perform easily accelerating and decelerating control at a start and a stop with high precision and to reduce the size of a scanner by fitting linear motors to two needles respectively in reflection systems. CONSTITUTION:The reflection systems 5 and 6 move while fixed to the needles 4b and 4c, and a photosensitive drum 9 is driven by a motor 10 to rotate, thereby outputting frequency signals FG1-FG3 proportional to the speed respectively. A speed setting device 15, on the other hand, inputs a reference original oscillation signal fS0 to generate reference signals fS1-fS3 for speed control on the basis of the input signal, and those signals are settable to optional values so as to determine speeds of the needles 4b and 4c and the motor 10. Then, phase comparators 14a-14c compare the phases of the signals fS1-fS3 with those of the signals FG1-FG3 to output their phase errors as signals fE1-fE3, which are amplified by amplifiers 13a-13c after speed feedback components as signals FG1-FG3 are added to drive the needles 4b and 4c and motor 10 after unnecessary high frequency components are cut by a filter and driving parts 12a-12c. |
