Ricoh B230 Service Manual

 
SM 6-13 B230/B237 
Detailed 
Descriptions 
6.2.5  TONER SUPPLY CONTROL 
Overview 
Toner supply control determines  how long the toner supply clutch turns on. This determines 
the amount of toner supplied.  This is done before every development for each color. 
Toner supply control uses  the following factors: 
ƒ   Density of the toner in the develo per (detected by the TD sensor) - V
REF, VT 
ƒ   Pixel count: Determines how much toner was used for the page 
The image density is kept  constant by...

 
B230/B237 6-14  SM 
6.2.6 TONER NEAR END/TONER END DETECTION 
 
Toner Near End 
The controller considers the following information to determine the toner near end status: 
ƒ  Operation time counter of the toner attraction pump [A] 
ƒ Pixel counter  
These values are both stored in the memory chip [B] on the toner cartridge, and copied 
from the memory chip to the NVRAM on the BICU.   
If either value indicates that the amount of remaining toner is 50g or less, the machine 
enters the near-end...

 
SM 6-15 B230/B237 
Detailed 
Descriptions 
print black-and-white jobs only. 
Toner End Recovery 
The machine assumes that the toner cartridge has been replaced if either of the following 
occurs when the near-end or end status exists: 
ƒ  The front door is opened and closed. 
ƒ  The main switch is turned off and on. 
Then the machine starts to supply toner to the development unit. After supplying toner, the 
machine clears the toner near-end or end status if the following condition is detected: 
ƒ...

 
B230/B237 6-16  SM 
6.3 SCANNING 
6.3.1 OVERVIEW 
 
 
1. Scanner HP sensor 
2. ADF exposure glass 
3. 2nd scanner (2nd carriage) 
4. Scanner lamp 
5. 1st scanner (1st carriage) 6. Exposure glass 
7. Scanner motor 
8. Sensor board unit (SBU) 
9. Lens Block 
10. Original length sensor 
11. Original width sensor 
 
The original on the exposure glass or ARDF exposure glass reflects the light emitted from 
the scanner lamp. The reflected light goes to the CCD on the sensor board by way of the 
1st and 2nd...

 
SM 6-17 B230/B237 
Detailed 
Descriptions 
6.3.2 SCANNER DRIVE 
 
The scanner motor [A] drives the 1st scanner [B] and the 2nd scanner [C] through the 
scanner drive pulley, scanner drive shaft [D], and two scanner wires [E]. 
Book mode - 
The SBU board controls the scanner drive motor. The 2nd scanner speed is half that of the 
1st scanner. 
In reduction or enlargement mode, the scanning speed depends on the magnification ratio. 
The returning speed is always the same, whether in full size or...

 
B230/B237 6-18  SM 
6.3.3  ORIGINAL SIZE DETECTION 
 
ƒ  The original width sensors [A] detect the original width. The original length sensors [B] 
detect the original length. 
ƒ  The SBU controller on the SBU board checks each sensor status when the platen 
cover sensor [C] is activated as it is closed. It detects the original size by the on/off 
signals it gets from each sensor. 
ƒ  If the copy is made with the platen cover fully open, the SBU controller on the SBU 
determines the original size from...

 
SM 6-19 B230/B237 
Detailed 
Descriptions 
F4 
8.5 x 13, 8.25 x 
13, or 8 x 13 
SP 5126 controls the 
size that is detected 8.5” x 14”  O  O  O  X  X  00011100 
A4 LEF  8.5 x 11  X  X  X  O  O  00000011 
B5 LEF  -  X  X  X  O  X  00000010 
A4 SEF  11 x 8.5  X  O  O  X  X  00001100 
B5 SEF  -  X  X  O  X  X  00000100 
A5 LEF/ SEF 5.5 x 8.5, 
8.5 x 5.5 X X X X X 00000000 
 
ƒ  O: Paper present, X: Paper not present 
The above table shows the outputs of the sensors for each original size. This original...

 
B230/B237 6-20  SM 
6.4 IMAGE PROCESSING 
6.4.1 OVERVIEW 
 
6.4.2  SBU (SENSOR BOARD UNIT) 
SBU 
The VPU (Video Processor Unit) does the following functions: 
ƒ Black level correction 
ƒ  White level correction 
ƒ Gradation calibration 
ƒ  ADS control (Background Density) 
ƒ  Creating the SBU test pattern 
Operation Summary 
The signals from the 3-line CCD, one line for each color (R, G, B) and 2 analog signals per 
line (ODD, EVEN), are sampled by the ASIC and converted to digital signals in the...

 
SM 6-21 B230/B237 
Detailed 
Descriptions 
SP4-008-001 Sub Scan Mag  Sub Scan Magnification Adjustment 
SP4-010-001 Sub Scan Reg  Sub Scan Registration 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 
SP4-800-001 to -003 (ARDF density adjustments for R, G, B). After lens block replacement, 
do some copy samples with the ARDF, then check the copies. If the copies have 
background, change...

 
B230/B237 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 detector board: Bk/M-S 
7. F-theta lens-Bk/M   
8. WTL-Bk 9. WTL-M 
10. Synchronizing detector 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...