Atr Control - Canon iR C6800 Series Service Manual

<Particulars of Control>
Order Item
1 application of secondary
transfer bias
2 monitoring of the
environment sensor
3 determination of the
secondary transfer bias

7.4.5 ATR Control

The machine executes ATR control to compute the amount of toner to supply to the color developing assembly based
on the amount of toner it has used.
<Particulars of Control>
Computing the Amount of Toner to Supply
The machine determines the amount of toner to supply to individual color developing assemblies.
The following are particulars of individual operations:
<Particulars of Operation>
Computing the Amount of Toner to Supply
The machine determines the amount of toner to be supplied to individual color developing assemblies. The machine
uses 3 types of data to make these computations.
1. video count (executed for every color print)
The machine uses the video count data to predict the amount of toner likely to be consumed, and computes the
amount of toner consumed.
2. result of detection by the patch image read sensor (in response to an image ratio of 480%, as converted or 60 color
prints made continuously*1)
The machine uses the patch image read sensor to measure the toner image created on the ITB, and imposes correction
on the amount of toner to be supplied so that the density will be identical to the target density.
3. result of detection by the ATR sensor (executed for every 10 color prints)
The machine uses the ATR sensor to measure the developer on the cylinder of each color developing assembly, and
increases/decrease the toner supply target if the measurement is outside of the target density range.
*1: when this condition occurs, the machine stops the ongoing job and forms a patch on the intermediate transfer belt
for detection by the patch image read sensor.
T-7-15
Description
applies a specific level of bias to the secondary transfer
roller; then, uses HVT3 to detect the level of current and
feeds the data back to the DC controller.
uses the DC controller to compute the correction value
from the output of the environment sensor and the printing
information (paper type, 1st side/2nd side).
uses the DC controller to determine the best secondary
transfer bias while taking the correction value into account.
Chapter 7
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