| 摘要 |
PURPOSE:To realize low-cost and small-sized constitution, by substituting a mechanical filter with an electric filter and thus selecting the cutoff frequency of a high frequency oscillation component generated by a photosensitive drum optionally. CONSTITUTION:A pulse signal of frequency corresponding to the rotating speed of the photosensitive drum 2 is outputted from the direct rotating speed detector 20 of the rotating shaft of the drum 2 to a frequency-voltage transducer 21, which outputs a corresponding voltage signal to a low-pass filter 22. The low- pass filter removes high frequency oscillation components. Its time constant is varied adequately to select the cutoff frequency freely. The voltage signal is further inputted to the adder 23. The adder 23 inputs a set voltage synchronized with the output of a motor 1 from a CPU24 and a D-A converter 25 and by the sum voltage, an optical system carriage 11 is controlled through a voltage- frequency transducer 26, phase comparator 7, etc. |
