Ricoh B230 Service Manual

 
SM 6-23 B230/B237 
Detailed 
Descriptions 
6.5.2 OPTICAL PATH 
 
The laser beams for black [A] and yellow [B] are directed to the upper part of the polygon 
mirror [C]. Laser beams for magenta [E] and black [D] are directed to the lower part of the 
polygon mirror. The LD mirrors (see the previous page) deflect the laser beams for 
magenta and black towards the lower polygon mirror.   
The WTL [F] corrects the main scan line. Without this component, the line bends out 
towards the middle of the main...

 
B230/B237 6-24  SM 
6.5.3  LASER SYNCHRONIZING DETECTORS 
 
Overview 
The machine has four laser synchronizing detector boards (LSD). There is one at each 
corner of the laser optics-housing unit. 
The four LSD boards detect the following: 
ƒ  [A]: Scanning end position for yellow and cyan 
ƒ  [B]: Scanning start position for yellow and cyan 
ƒ  [C]: Scanning end position for magenta and black 
ƒ  [D]: Scanning start position for magenta and black.   
The machine recognizes each color from the time...

 
SM 6-25 B230/B237 
Detailed 
Descriptions 
6.5.4 LD SAFETY SWITCH 
 
A relay on the PSU ensures technician and user safety. It also prevents the laser beam 
from turning on during servicing. This relay turns off when the front cover, upper left cover, 
or right door is opened. At this time it cuts the power (+5V) supplied to the LD board for 
each color through the BICU. 
Two safety switches are used to turn the relay off. One switch is used for the front door. 
Another safety switch is used for the...

 
B230/B237 6-26  SM 
6.5.5  AUTOMATIC LINE POSITION ADJUSTMENT 
Overview 
CC, KK, YY, MM: Spaces between two lines of the same color 
KC, KY, KM: Spaces between a black line and a color line 
 
During automatic line position adjustment, the line patterns above are created eight times 
on the transfer belt. The spaces between the lines (CC, KK, YY, MM, KC, KY, KM) are 
measured by the front, center, and rear ID sensors. The controller takes the average of the 
spaces. Then it adjusts the following...

 
SM 6-27 B230/B237 
Detailed 
Descriptions 
timing for that color. 
Main scan line position for YCM 
If the machine detects that the image is out of position in the main scan direction, it 
changes the laser write start timing for each scan line. 
Magnification adjustment for KYCM 
If the machine detects that magnification adjustment is necessary, it changes the LD clock 
frequency for the required color. 
Skew for YCM 
The adjustment of the skew for YCM is based on the line position for K. 
Adjustment...

 
B230/B237 6-28  SM 
outputs (SP2-193-004: [default: 200 pages) 
4.  Color counter > Output threshold for color outputs (SP2-193-005: [default: 200 pages]) 
Interval: Job end: 
This starts automatically at the end of a print job. 
Line position adjustment is automatically done once if one of these conditions occurs: 
1. Δt > Time threshold (SP2-193-009: [default: 300 minutes]) 
2. ΔT > Temperature threshold (SP2-193-008: [default: 5°C]) 
3.  B/W counter (SP3-510-005) + Color counter (SP3-510-006) >...

 
SM 6-29 B230/B237 
Detailed 
Descriptions 
Main Scan Skew Adjustment 
 
The WTL positioning motors for magenta [A], cyan [B], and yellow [C] adjust the angle of 
the WTL [D] respectively, based on the WTL position for black. This mechanism corrects 
main scan skew.   
ID Sensors 
 
There are seven ID sensors. Three of them are for the line position adjustment. Four of 
them are for process control. The ID sensor shutter [A] covers the sensors when the 
machine is idle. 
When the ID sensor shutter...

 
B230/B237 6-30  SM 
Shutter Mechanism 
 
The laser optics housing unit has a shutter. As a result, toner and other dust do not fall on 
the glass of the laser optics housing. The shutter motor [A] moves the shutter [B] in the 
direction of the arrow with the cam [C] (to open: black arrow direction, to close: white arrow 
direction).  
First, the actuator [D] stays at the shutter closed sensor [E]. The shutter motor opens the 
shutter and the actuator moves to the shutter open sensor position [F] after...

 
SM 6-31 B230/B237 
Detailed 
Descriptions 
6.6  PCU (PHOTO CONDUCTOR UNIT) 
6.6.1 OVERVIEW 
 
 
1. OPC drum 
2. Cleaning blade 
3. Brush roller   
4. Lubricant bar 
5. Lubricant application blade 
6. Cleaning roller (charge roller) 7. Charge roller (non-contact) 
8. TD sensor/ID chip 
9. Mixing auger 
10. Development roller 
11. Inner pressure adjustment filter 
 
This machine has four tandem PCUs. Therefore, four color developments are possible 
during one paper path. This improves the productivity of...

 
B230/B237 6-32  SM 
6.6.2  AROUND THE DRUM 
Drum Drive 
 
The drum/development drive motor-K [A] drives the drum unit for black.   
The drum drive motor-CMY [B] drives the drum units for magenta, cyan, and yellow. Using 
one motor to drive these three drums reduces CMY color misalignment. 
Both motors are brush-less DC motors. This helps to reduce the drive noise.   
Phase Control Mechanism 
The machine uses the drum gear position sensors to detect if the drum motors rotate. 
SC380 shows when it...