Canon CLBR 460ps Service Manual page 113

4. Transfer block
a. Outline
The transfer block consists of an ITB unit, a secondary transfer roller unit, and an Intermediate
transfer belt contact unit. This block transfers the toner transferred from the photosensitive
drum to the paper and cleans the residual toner.
The intermediate transfer belt is driven by the drum motor (M4). The ITB cleaning roller
rotates with the intermediate transfer belt. The secondary transfer roller is rotated by the fix-
ing motor (M1). The secondary transfer roller is pressed against the intermediate transfer belt
when the secondary transfer roller contact clutch (CL4) is turned ON. The ITB cleaning roller is
pressed against the intermediate transfer belt when the ITB cleaning roller contact clutch (CL3)
is turned ON. The intermediate transfer belt contact lever presses the intermediate transfer belt
against the photosensitive drum when the intermediate transfer belt contact clutch (CL2) is
turned ON.
The ITB unit and peripheral devices has an ITB unit life sensor (PS1), which detects the life
of the ITB unit, and an ITB home position sensor (PS5), which detects the home position of the
intermediate transfer belt.
CL3
Contact
cam
CL2
ITB contact lever
M1
M1: Fixing motor
M4: Drum motor
CL2: ITBunit contact clutch
CL3: ITB cleaning roller contact clutch
CL4: Secondary transfer roller clutch
DC controller PCB
Developing PCB
Photo-
sensitive
drum
ITBunit
PS5
ITB cleaning roller
Secondary transfer roller
Contact cam
CL4
Figure 2-4-11
M4
PS1
PS1:ITB unit life sensor
PS5:ITB home position sensor
CHAPTER 2
2 - 55