Konica Minolta A00F011 Service Manual - Page 118

Image stabilization control

Page 118 highlights

magicolor 4650EN magicolor 4650DN Composition/Operation Theory of operation Ver. 1.0 Nov. 2007 21. Image stabilization control 21. Image stabilization control • To ensure that a stabilized output image is produced at all times, a comprehensive control is provided for the developing bias voltage, laser light intensity, registration correction, gamma characteristics detection, and other parameters. 21.1 Overview of image stabilization control • Image stabilization control may be divided into three types: complete correction control, simplified correction control, and individual registration control. The following explain specific details of each type of control. 21.1.1 Complete correction control • Controls 1 through 6 below are collectively called the "complete correction control." • For details of each of these controls, see the relevant page. Control name Purpose IDC sensor offset value To check the low gain output value and offset voltage value of the IDC check sensor when the shutter is closed. 1 IDC sensor calibration control Changes in various types of characteristics due to change with time of the IDC sensor (deteriorated LED, dirty sensor surface), part-to-part variations in the sensors, and change of environment affect the IDC Sensor output corresponding to the clear transfer belt surface. To correct fluctuations in the output, the sensor LED intensity is adjusted so as to keep constant the IDC sensor output value. 2 Developing bias Vpp control If the developing bias voltage (Vpp) is too high for the Ds distance in each toner cartridge, a leak image (background leak, image area leak) results. If Vpp is excessively low, halftone reproducibility becomes poor. This control detects a Vpp range, in which no image failure occurs, to set the optimum Vpp. Developing bias control 3 (control of the maximum To correct the target amount of toner sticking to the transfer belt to form amount of toner sticking the solid image. to the transfer belt) To correct the target level of fluctuations in fine line reproduction and 4 Laser light intensity control reverse image (white on black) reproduction that occur due to variations in photo conductor electrostatic characteristics, developing characteristics, and transfer characteristics (part-to-part variations, environment, durability). 5 Gamma characteristics detection control To correct the tone by using the IDC sensor to measure the density of a gradation pattern produced on the transfer belt and sending the results of the measurement to the controller. 6 Registration correction control To correct incorrect color registration that occurs due to variations in parts of the main body used for regulating different drawing positions. 83

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Theory of operation Ver. 1.0 Nov. 2007
21. Image stabilization control
83
magicolor 4650EN
magicolor 4650DN
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21.
Image stabilization control
To ensure that a stabilized output image is produced at all times, a comprehensive con-
trol is provided for the developing bias voltage, laser light intensity, registration correction,
gamma characteristics detection, and other parameters.
21.1
Overview of image stabilization control
Image stabilization control may be divided into three types: complete correction control,
simplified correction control, and individual registration control. The following explain
specific details of each type of control.
21.1.1
Complete correction control
Controls 1 through 6 below are collectively called the “complete correction control.”
For details of each of these controls, see the relevant page.
Control name
Purpose
IDC sensor offset value
check
To check the low gain output value and offset voltage value of the IDC
sensor when the shutter is closed.
1
IDC sensor calibration
control
Changes in various types of characteristics due to change with time of
the IDC sensor (deteriorated LED, dirty sensor surface), part-to-part
variations in the sensors, and change of environment affect the IDC Sen-
sor output corresponding to the clear transfer belt surface. To correct
fluctuations in the output, the sensor LED intensity is adjusted so as to
keep constant the IDC sensor output value.
2
Developing bias Vpp
control
If the developing bias voltage (Vpp) is too high for the Ds distance in
each toner cartridge, a leak image (background leak, image area leak)
results. If Vpp is excessively low, halftone reproducibility becomes poor.
This control detects a Vpp range, in which no image failure occurs, to set
the optimum Vpp.
3
Developing bias control
(control of the maximum
amount of toner sticking
to the transfer belt)
To correct the target amount of toner sticking to the transfer belt to form
the solid image.
4
Laser light intensity con-
trol
To correct the target level of fluctuations in fine line reproduction and
reverse image (white on black) reproduction that occur due to variations
in photo conductor electrostatic characteristics, developing characteris-
tics, and transfer characteristics (part-to-part variations, environment,
durability).
5
Gamma characteristics
detection control
To correct the tone by using the IDC sensor to measure the density of a
gradation pattern produced on the transfer belt and sending the results
of the measurement to the controller.
6
Registration correction
control
To correct incorrect color registration that occurs due to variations in
parts of the main body used for regulating different drawing positions.