Konica Minolta bizhub C658 Service Manual page 1834

bizhub C658/C558/C458/C368/C308/C258
8.2 Drive
The following illustration is for bizhub C368/C308/C258.
[1]
[1] Transfer belt
[3] 2nd transfer roller
8.3 Operation
8.3.1 2nd transfer control
• To transfer the toner image formed on the transfer belt onto the paper, the 2nd transfer voltage supplied from the high voltage unit is
applied to the 2nd transfer roller.
• Resistance of the 2nd transfer roller changes with an environmental change, durability, and other factors. To maintain an optimum output
voltage, fixed current is passed through the 2nd transfer roller and the voltage being outputted at that time is detected. An appropriate 2nd
transfer voltage is determined based on the measured voltage and other information such as "type of paper used", "temperature and
humidity", "color mode or black mode", and "1-sided/2-sided".
[1]
[1] 2nd transfer roller
[3] 2nd transfer voltage application terminal
(1) Execution timing
• The 2nd transfer control is executed when a print job is received under any of the following conditions:
"Main power switch is turned ON"
"Power key is pushed"
"The machine exits the sleep mode"
"The threshold value of a change in machine interior temperature is exceeded."
(2) 2nd transfer control during image stabilization control
• In this machine, the 2nd transfer roller does not have a retraction mechanism, so that the transfer belt and 2nd transfer roller are pressed
up against each other at all times.
• During image stabilization control, a toner image for adjustment purpose is formed on the surface of the transfer belt. A negative voltage
is therefore applied to the 2nd transfer roller during image stabilization control. The amount of toner sticking to the 2nd transfer roller is
thereby reduced.
8.3.2 Control of toner application to 2nd transfer roller
• In this machine, the 2nd transfer roller does not have a retraction mechanism, so that the transfer belt and 2nd transfer roller are pressed
up against each other at all times.
• If a new 2nd transfer roller that has replaced an old one is left to stand idle for a long period of time, a substance contained in the new roller
sticks to the surface of the transfer belt, which could result in noise in the print image.
O THEORY OF OPERATION bizhub C658/C558/C458/C368/C308/C258 > 8. 2ND
[2]
[3]
[2] Transport motor (M1)
- -
[3]
[2]
[2] 2nd transfer voltage conductive plate
- -
O-59
TRANSFER SECTION