User Guide

If data from the color-misregistration and image-density sensors is outside a specified range when the
product is turned on or when it is beginning the calibration sequence, the DC controller determines that
these sensors have failed, and it notifies the formatter.
Image stabilization control
Environmental changes or deterioration of the photosensitive drums and toner can cause variations in
the image density. The image-stabilization control reduces these fluctuations. There are three kinds of
image stabilization controls.
The formatter control is performed by the formatter.
Table 1-12 Image-stabilization controls
Image stabilization control Description
Environment change control The environment change control calibrates each high-voltage bias to obtain an
appropriate image according to the environment changes. The DC controller
determines the environment where the product is installed based on the surrounding
temperature and humidity data from the environment sensor, controls, and related
biases. This control occurs under the following circumstances:
●
The toner cartridge is replaced.
The DC controller notifies the formatter when it encounters a communication error
with the environmental sensor.
Image density control (DMAX) This control corrects variations in image density related to deterioration of the
photosensitive drum or the toner. The DC controller adjusts the high-voltage biases
to correct the problem under the following conditions:
●
The sub thermistor detects a temperature that is too low when the product is
turned on.
●
After the print operation is completed for a specific period of the time.
●
A toner cartridge is replaced.
●
The ITB is replaced.
●
A specified number of pages have printed.
●
The formatter sends a command.
●
The environment is relatively charged.
Image halftone control (DHALF) The image halftone control is performed by the formatter. The DC controller
measures the halftone pattern according to the command from the formatter. The
formatter performs this control to calibrate the halftone, based on the halftone-
density measurements, under the following conditions:
●
The formatter sends a command.
●
The DMAX is completed.
The DC controller determines an RD sensor failure and notifies the formatter if it detects an out-of-
specified-data value from the RD sensor when the product is turned on or when the color misregistration
control starts.
ENWW
Image formation system
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