Ricoh Mp C3000 Service Manual

							 
SM 6-21 B230/B237/D042 
Detailed 
Descriptions 
 
SP4-008-001  Sub Scan Mag  Sub Scan M
agnification Adjustment 
SP4-010-001 Sub Scan Reg  Sub Scan R
egistration Adjustment 
SP4-011-001 Main Scan Reg  Main Scan Registration Adjustment 
 
Also, before lens block replacement, enter
 the SP mode and note the settings of 
SP4685-001 &  002; SP4686-001 & 002; and SP4687-001  & 002 (Gray Balance Set for R, 
G, B). After lens block replacement, check c opy samples with the ARDF and Platen. If the 
copies have background, change  SP4685-001 & 002; SP4686-001  & 002; and 
SP4687-001 &  002 to their previous settings, or adjust until the background is acceptable.   
SBU Test Mode  
There are two SP codes to create a test patt ern which can be used as a diagnostic tool to 
troubleshoot problems in the SBU: 
ƒ   SP4907 001 SBU Pattern - Test Pattern 
ƒ   SP4907 002 SBU Pattern - Select Fixed Pattern 
To print the pattern: 
ƒ   Select the pattern to print. 
ƒ   Touch Copy Window then press the Start key twice. 
6.4.3 IPU (IMAGE  PROCESSING UNIT) 
The IPU does the following: 
ƒ  Controls the scanner 
ƒ   Processes the image signals from the SBU and sends them over the PCI bus to the 
controller memory 
ƒ   Receives the image processing signals sent  over the PCI bus from the controller 
memory, processes them, then outputs them to the VGAVD. 
ƒ   Outputs the control signals for the ARDF 
ƒ   Controls the relay of power and signals 
Image processing, ADS correction, and li ne width correction are done on the BICU board 
for all the digital data sent from  the SBU. Finally, the processed  data is sent to the printer as 
digital signals (4 bits/pixel). 
Rev. 06/24/2009
⇒   
						

							 
B230/B237/D042 6-22 SM 
6.5 LASER EXPOSURE 
6.5.1 OVERVIEW 
 
 
1. Synchronizing detector board: Y/C-E 
2. LD unit-Y 
3. LD unit-C 
4. LD unit-Bk 
5. LD unit-M   
6. Synchronizing detec tor board: Bk/M-S 
7. F-theta lens-Bk/M   
8. WTL-Bk  9. WTL-M 
10. Synchronizing det
ector board: Bk/M-E
11. Polygon mirror motor 
12. Synchronizing detector board: Y/C-S 
13. WTL-C 
14 WTL-Y 
15. F-theta lens-Y/C 
 
This machine uses four LD units and one polygon mirror motor to produce latent images on 
four OPC drums (one drum for each color toner). 
There are two hexagonal mirrors. Each mirror reflects beams from two LD units.   
Laser exposure for black and magenta starts from  the rear side of the drum. But for yellow 
and cyan it starts from the front side of the  drum. This is because the units for black and 
magenta are on the other side of the polygon  mirror from the units for yellow and cyan.  
						

							 
SM 6-23 B230/B237/D042 
Detailed 
Descriptions 
6.5.2 OPTICAL PATH 
 
The laser beams for black [A] and yellow [B] ar e 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 prev ious 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 scan. The central bend of the WTL is adjusted in the factory. 
The speed of the polygon mirror depends on  the selected mode and model (see below). 
 
Mode  Polygon motor 
speed (rpm)  Process line 
speed (mm/s)  Print speed 
(ppm)  
Plain 
/Middle Thick    32,598 138 mm/s  C1a: 25 
C1b: 30 
OHP/Thick 36,378 77 
mm/s  16 
  
						

							 
B230/B237/D042 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 that they are detected.   
Main Scan Start Detection  
For magenta and black, the LSD at the rear detec ts the start of the main scan. For yellow 
and cyan, the LSD at the front det ects the start of the main scan. The arrow [E] indicates 
the scanning direction. 
Clock Frequency Adjustment  
Each LSD ensures that the number of laser cloc k pulses in the main scan is constant. If the 
count for one particular beam varies from nor mal, the LD clock frequency for that beam is 
adjusted. 
If the board at the end position is defective, t he clock frequency cannot be adjusted. At this 
time, you must disable the det ection feature with SP2-186-1.  
						

							 
SM 6-25 B230/B237/D042 
Detailed 
Descriptions 
6.5.4 LD SAFETY SWITCH 
 
A relay on the PSU ensures technician and us er safety. It also prevents the laser beam 
from turning on during servicing. This relay turn s 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 re lay off. One switch is used for the front door. 
Another safety switch is used for the right door. 
ƒ  PMAC: Precise Pulse Modulat ion ASIC on C-MOS technology 
ƒ  LDB: LD Drive Board (i ncluded in the LD Unit) 
Error Messages  
Along with other switches, the LD safety swit ches help show error messages related to 
external covers. When one or more covers are open, the messages, “Cover is open.” and 
“Close the indicated cover,” show with a di agram. The diagram shows which cover is open.  
						

							 
B230/B237/D042 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, t he 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 follo wing positions and magnification: 
ƒ  Sub scan line position for CMY   
ƒ  Main scan line position for CMY 
ƒ  Magnification ratio for CKMY 
ƒ  Skew for CMY 
The transfer belt-cleaning unit cleans the trans fer belt after the patterns are measured. 
SC285 shows if an error is detect ed four times consecutively. 
Summary of Each Adjustment 
Sub scan line position for YCM 
The adjustment of the sub-scan line position for YCM is  based on the line position for K 
(color registration). The machine measures t he gaps between the lines of each color in the 
pattern on the transfer belt. If the gaps for a co lor are not correct, the machine moves the 
image of the color up or down the sub scan ax is. To do this, it changes the laser write  
						

							 
SM 6-27 B230/B237/D042 
Detailed 
Descriptions 
timing for that color. 
Main scan line position for YCM  
If the machine detects that t he 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 adjust ment 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 Conditions 
Line position adjustment can be turned on or of f with SP2-193-001. However, it is normally 
recommended to turn on this function.   
Line position adjustment ti ming depends on several SP mode settings. These are 
described below.   
Δt = Time since the previous  line position adjustment   
ΔT = Temperature change between the temper ature of the previous line position 
adjustment and the current temperature 
Forced (SP2-111-001 to -003):  
This activates the line positi on adjustment manually. There are  three types of line position 
adjustment mode. See the SP table for details. 
Initial:  
This starts automatically when the power is tu rned on, or when the machine recovers from 
the energy saver mode. 
Line position adjustment is automatically done twice  if one of these conditions occurs: 
1.  Δt > Time threshold (SP2-193-012: [default: 600 minutes])   
2.  ΔT > Temperature threshold (SP2-193-011: [default: 10°C])   
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]) 
Interval: During job: 
This interrupts printing and then starts automatic ally if one of these conditions occurs when 
the machine checks at the sheet interval  specified with SP3-512-001 (default: 30 page). 
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) > Output threshold for all  
						

							 
B230/B237/D042 6-28 SM 
outputs (SP2-193-004: [default: 200 pages) 
4.  Color counter > Output th reshold 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) > Output threshold for all 
outputs (SP2-193-002: [default: 500 pages) 
4.  Color counter > Output th reshold for color outputs (SP2-193-003: [default: 200 pages]) 
Front door open/close: 
This starts automatically when the front door is opened/closed. 
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]) 
In stand-by mode:  
This is automatically done  once if both conditions occur at t he same time. However, it is 
not done if the machine is in the energy saver mode. 
1.  Δt > Time threshold (SP2-193-009: [default: 300 minutes]) or  ΔT > Temperature 
threshold (SP2-193-008: [default: 5°C]) 
2.  B/W counter (SP3-510-005) > Output  threshold for B/W outputs (SP2-193-002: 
[default: 500 pages]) or Color counter > Output threshold for color outputs 
(SP2-193-003: [default: 200 pages]) 
After new PCU or Image Transfer Belt Unit detection  
When the machine detects a new unit (one of the PCUs or the Image Tr ansfer Belt Unit), 
line position adjustment  is automatically done twice. 
If the main scan magnification changes  
This is detected by the main scan synchroniza tion detectors at each end of the scan line for 
each color. 
If the magnification changes by more than 1% (threshold adjustable SP2-193-010), line 
position adjustment  is done again.  
						

							 
SM 6-29 B230/B237/D042 
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 pos ition 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 solenoi d [B] is activated, ID sensor shutter [A] slides to the left. 
This mechanism prevents the ID sensors from becoming dirty with toner or dust.  
						

							 
B230/B237/D042 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 dire ction, 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 shutte r open sensor position [F] after the polygon 
motor has turned on.   
Finally, the shutter motor closes the shutte r and the actuator moves back to the shutter 
closed sensor position [E] after t he polygon motor has turned off.     
One of SC290 to 296 occurs if the output of the shutter open [F] or closed sensor [E] does 
not change after the shutter motor turned on. 
⇒
Rev. 12/2006