| 摘要 |
PURPOSE:To obtain a good-quality binary signal, by converting pulses from the movement quantity detecting circuit, which generates pulses of a repeat frequency corresponding to the subscanning speed, to a voltage by the frequency-voltage converter and by controlling the light quantity of the light source in accordance with the subscanning speed. CONSTITUTION:Each time the movement distance of the device in the subscanning direction reaches a prescribed value, the pulse generated from movement quantity detecting circuit DS is given to frequency-voltage converter FVC and is converted to a voltage corresponding to the repeat frequency of pulses generated from detecting circuit DS by converter FVC and is given to light quantity control circuit PVC of light source L for illumination of the original. The repeat frequency of the said pulses is proportional to the subscanning speed, and consequently, the voltage proportional to the subscanning speed is output from coverter FVC. When the output voltage from converter FVC is given to light quantity control circuit PVC, the light quantity of light source L is so controlled that the output voltage of converter FVC increase or reduces the light quantity of light source L in accordance with the subscanning speed. |
