Xerox Phaser 7100 Service Manual

General and Operation Overview
Xerox Internal Use Only Phaser 7100 Service Manual 1-87
Toner Supply Control
The Toner Supply Control keeps the Toner density in the Developer Housing Assembly at a certain level
and determines the timing to supply toner from the Toner Cartridge to the Developer Housing
Assembly, as well as the toner supply amount that is required to maintain the image density. The
printer calculates the toner supply amount by the ICDC Count and the toner density of the patch that
is obtained by the CTD Sensor. The toner supply amount is then calculated as the operating time of the
Toner Dispense Motor. Based on the calculated value, just the right amount of toner is supplied to the
Developer Housing Assembly by the timing.
Toner Supply Amount Calculation by ICDC (Image Count Dispense Control) - Counts the number of
pixels in an image and uses the count value to calculate the toner supply amount.
Calculation of Toner Supply Amount from Patch Density
1. The temperature and humidity in the printer is measured and the measured values are used to
adjust the various type of voltage (ROS LD Power, BCR Applied Voltage, Developer Bias, BTR
Applied Voltage), which are then used to generate a patch on the Intermediate Transfer Belt.
2. The power of the LED that emits light from the CTD Sensor is adjusted.
3. The patch density is then read by the CTD Sensor, the value of which is used to perform correction
for the depletion of the toner, the deterioration of the Intermediate Transfer Belt, etc., and then
calculate the toner supply amount.
The calculation of the toner supply amount from the patch density is performed at the same timing as
the Potential Control.
Others
High Area Coverage (HAC) Mode - This mode controls the density to prevent it from dropping due to
insufficient toner supply amount when performing continuous printing of HAC images. It counts the
number of pixels as printing is in progress and pauses the printing when it has reached the specified
value or higher to add the toner.
Low Area Coverage (LAC) Mode - Performing continuous printing of LAC images might stress the
toner and cause poor transfer, background, etc. to appear. This mode is to solve that problem. It counts
the number of pixels as printing is in progress and pauses printing when it has reached the specified
value or lower to remove excess toner from the Developer Housing Assembly.

Xerox Phaser 7100 Specifications

General

Brand	Xerox
Model	Phaser 7100
Category	Printer
Language	English