Ricoh Mp C3000 Service Manual
Here you can view all the pages of manual Ricoh Mp C3000 Service Manual. The Ricoh manuals for All in One Printer are available online for free. You can easily download all the documents as PDF.
Page 831
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...
Page 832
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...
Page 833
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...
Page 834
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...
Page 835
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:...
Page 836
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...
Page 837
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...
Page 838
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...
Page 839
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...
Page 840
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...