Ricoh Mp C3000 Service Manual

 
SM 6-11 B230/B237/D042 
Detailed 
Descriptions 
sensor detects a pattern for each color  (see the ‘Printing Process’ section).   
The ID sensor checks the bare transfer belt’s  reflectivity. Then the machine calibrates the 
ID sensor until its output when  reading the bare transfer belt (known as VSG) is as follows. 
ƒ  VSG = 4.0 ± 0.5 Volts 
This calibration compensates fo r the transfer belt’s condition and the ID sensor condition. 
For example, dirt on the surfac e of the belt or ID sensor. 
VSG...

 
B230/B237/D042 6-12 SM 
Step 4: Toner Amount Calculation 
The machine calculates the amount of toner on  the transfer belt that is required to make 
each of the 10 grades of the sensor pattern. To  do this, the machine uses the output values 
of the ID sensor from each grade of the pattern. 
The amounts of toner are expressed  as M/A (mass per unit area, mg/cm
2) 
Step 5: V
D, VB, VL Selection and VTREF Adjustment  
The machine determines the relationship betw een the amount of toner on the transfer...

 
SM 6-13 B230/B237/D042 
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/D042 6-14 SM 
6.2.6 TONER NEAR END/TONER END DETECTION 
 
Toner Near End  
The controller considers the following inform ation 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/D042 
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:...

 
B230/B237/D042 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 ex
posure 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...

 
SM 6-17 B230/B237/D042 
Detailed 
Descriptions 
6.3.2 SCANNER DRIVE 
 
The scanner motor [A] drives the 1st sc anner [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 m ode, the scanning speed depends on  the magnification ratio. 
The returning speed is always the same, whet her in full size...

 
B230/B237/D042 6-18 SM 
6.3.3  ORIGINAL SIZE DETECTION 
 
ƒ  The original width sensors [A] detect the orig inal width. The original length sensors [B] 
detect the original length. 
ƒ  The SBU controller on the SBU board checks each sensor stat us 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 cove r fully open, the SBU controller on the SBU 
determines the original...

 
SM 6-19 B230/B237/D042 
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...

 
B230/B237/D042 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...