Image Stabilization Control Flow While In The Print And The Idle - Konica Minolta bizhub 500 Service Manual

21. IMAGE STABILIZATION CONTROL
21.2.2

Image stabilization control flow while in the print and the idle

The following shows the image stabilization control flow while in the print and the idle.
Print start signal ON
A. Toner density control
B. Developing potential adjustment control
A. Toner density control
(1) Method
• Develop on the drum a toner patch once every 5 prints after the main power switch (SW1) is turned ON and
read the patch density with the IDC sensor (IDCS).
• When the patch density is below the reference value, the operation varies based on the developing theta.
a: When the developing theta is below the reference value: Increase the number of control rotations of the
developing roller according to the patch density.
b: When the developing theta gets to the reference value: Drive the toner supply motor (M4) for the time just
calculated based on the patch density and the paper size to supply toner.
B. Developing potential adjustment control
(1) Purpose
Because of developer and photosensitive material being deteriorated due to durability, it becomes difficult to
secure the stable amount of toner on the photosensitive material. For that reason, calculate the correction
amount based on the machine inside temperature and the time period during which the photosensitive material
is driven and make corrections of the output values of the charging grid and the developing bias to secure the
stable amount of toner.
(2) Method
Detect the machine inside humidity with the humidity sensor (HUMS) when turning ON the power switch (SW2)
8 hours or more after turning it OFF.
Calculate the correction amount based on the machine inside humidity detected and the time period during
which the photosensitive material is driven.
Make corrections of the output value of the charging grid and the developing bias based on the correction
amount calculated.
When the time period during which SW2 is turned ON after OFF is less than 8 hours, use the value of the
machine inside humidity detected last time.
(3) Execution timing
For each job print.
86
Start of print
End of print
Stand-by
Theory of Operation Ver1.0 Feb.2006
Every 20 prints
C. Dot diameter adjustment control