This machine uses four AIOs and four laser beams for color printing. Each AIO contains a drum, charge roller, cleaning brush, blade, development roller and mixing auger.

The toner image on each drum is moved to the image transfer belt. The four colors are put on the belt. All four toners are put on the belt at the same time. Then the completed four-color image is moved to the paper.

  1. OPC charge (AIO):
    The charge roller gives the OPC a negative charge.
  2. Laser exposure:
    The laser beam from the laser diode (LD) goes through the lens and mirrors and to the drum. To make a latent image on the drum, the machine turns the laser beam on and off.
  3. Development (AIO):
    The development roller moves negatively-charged toner to the latent image on the drum surface. This machine uses four development units (one for each color).
  4. Image transfer:
    The charge that is applied to the image transfer roller pulls the toner from the drum to the transfer belt. Four toner images are put on the paper at the same time.
  5. Cleaning for the OPC:
    The cleaning blade removes remaining toner on the drum surface after image transfer to the paper.
  6. Quenching for the Development Roller:
    Charge is removed from the development roller with a quenching sheet in the AIO. There is no quenching for the OPC drum.
  7. Paper Transfer and Separation:
    Toner transfers from the image transfer belt to the paper when the paper is fed between the image transfer belt and transfer roller. After transfer, the paper separates from the image transfer belt, because of a discharge plate immediately after the transfer roller.
  8. TM (Toner Mark) sensor:
    The TM sensor board contains three TM sensors (one at the left, one at the center, and one at the right). The center TM sensor detects the density of the sensor patterns on the transfer belt. The TM sensor output is used for process control and for automatic line-position adjustment, skew, and color registration adjustments for the latent image.