Two methods of toner supply are used with this machine to stabilize the amount of toner supplied to the development unit.

  • 0: Fixed supply
    This mode fixes the amount of toner supplied to the development unit. Do not use this mode except for troubleshooting.
  • 4: DANC Supply (with Vtref Correction)

    In this mode, the necessary amount of toner is supplied to the area where the toner is consumed in the development unit, in order to steady the toner density in the development unit. Choose this mode normally.
    *DANC Supply: Divided image Active Noise Control (Image Divide Type Active Noise Control)

If the toner supply amount is calculated based on the amount of toner used in the covered areas only, errors can increase, especially when changes occur in ambient temperature and drum characteristics. This makes it difficult to control the toner supply amount only with the pixel count.

Therefore, the ID pattern is created on the ITB between sheets at a set interval (default: every 10 sheets). The machine controls the Vtref value using the readings of the ID sensor pattern on the ITB, to stabilize the amount of toner on the ITB.

ID Pattern Detection for Toner Supply Control

The ID pattern is created on the ITB between sheets at a set interval (default: every 10 sheets). The machine controls the Vtref value using the readings of the ID sensor pattern on the ITB, to stabilize the amount of toner on the ITB.

The target amount of toner on the ITB (M/A) is specified in the following SPs.

  • K toner: SP3-620-001
  • YMC toner: SP3-620-002 to 004

The default of the target amount of toner on the ITB is as follows.

  • Plain paper
    BK printing: 0.378 mg/cm2, Color printing: 0.433 mg/cm2
  • Glossy paper
    BK printing: 0.378 mg/cm2, Color printing: 0.389 mg/cm2

The toner supply control is performed using Vt and Vtref. The machine constantly controls the toner density (toner supply amount for the development unit) to bring Vt (TD sensor output at the present time) close to Vtref (target output of the TD sensor).

  • When Vt is greater than Vtref (when the density of the ID sensor pattern is higher than the target amount of toner):
    The machine performs the toner supply control so that Vtref increases (decreases the toner supply amount for the development unit).
  • When Vt is less than Vtref (when the density of the ID sensor pattern is lower than the target amount of toner):
    The machine performs the toner supply control so that Vtref decreases (increases the toner supply amount for the development unit).