SERVICE MANUAL - O. Rensch OHG

2DC
(1) ISU unit
The ISU unit consists of an exposure lamp, three mirrors, an ISU lens, a CCD board, and so on. Also an inverter board
for driving the exposure lamp and a scanner home position sensor for detecting the home position of the ISU unit are
incorporated.
The original on the contact glass is exposed to the light of the exposure lamp that is reflected by the reflector. The image
is input through reflection by the three mirrors and through the ISU lens to the CCD image sensor on the CCD board.
The CCD image sensor scans one row of the image in the main scan direction, converts it to electric signals, and outputs
them to the main board. Then the ISU unit is moved in the sub scan direction along the scanner shaft, and the CCD
image sensor scans the next row of the image in the main scan direction. The operation described above is repeated for
scanning the overall image of the original. If an optional DP is used, the ISU unit stops at the position of the DP contact
glass and scans sequentially one row of the image on the original in synchronization with the moving timing of the
original in the sub scan direction by driving the DP.
Original
6
8
7
5
1
2
3
4
Figure 2-1-6 ISU unit
1 Exposure lamp
2 Scanner reflector
3 Mirror A
4 Mirror A
5 Mirror B
6 ISU lens
7 CCD image sensor
8 CCD board
2-1-6