Image Processing To learn how the reader controller processes original image read by the CIS

Purpose: To learn how the reader controller processes original image read by the CIS

　

　

1. Overview

Original image read by the CIS is processed by the reader controller, and then is sent to the main controller.  The reader controller converts the analog signal sent by the CIS into the digital signal.  Also, it evens image density level.
The image processing consists of the following 3 steps.

1) Analog image processing

2) A/D conversion processing

3) Shading processing

　

The flowchart of image processing and details of each step are shown below.

Step	Item	Detail
1	Analog image processing	To perform image processing of the analog signal (voltage value signal) output from the CIS. 　1) Gain Correction: To uniform gain of the analog signal. 　2) Offset Correction: To uniform output voltage of places where there is no incoming light.
2	A/D Conversion	To convert the analog signal into the digital signal corresponding to voltage value of each pixel
3	Shading processing	To uniform density level by correcting reading image density based on density measurement with the standard while plate This is performed each time 1 line is scanned.

Image processing system
<Purpose>
	In this unit, you will learn how the image data, which are sent from reader unit or external devices, are processed by the main controller and are sent to the DC controller.  You will also learn about the structure and function of each unit, which is involved in image processing, and about the work service person should do. Purpose: To learn about the outline of the image processing system, such as the components or the specifications. 　 　 1. Outline In the image processing system, the data sent from reader unit or external devices are converted into the format for printing.  The main controller PCB handles data processing.  The main controller converts the data sent from reader unit or external devices into the video signals and sends them to the DC controller PCB.  See the components of the image processing system below. 2. Specifications list of the image processing system Specifications in the image processing system are as follows. 　 Item Function/Method Main controller PCB System control/Memory control/Printer output image processing control/Reader image input processing/Rendering processing/Color LCD controller/Card reader connection interface/Image processing for FAX, etc. SRAM Service mode set value by SRAM/Preservation of HDD administrative information, etc. (Note: SRAM is direct-mounted on the main controller.) Image memory (SDRAM) Temporarily saving of the image data Capacity: 256MB (Max. 512MB) (Note: There are two slots for SDRAM on the main controller.  Use the upper slot first.) BOOTROM Storage of the program for the BOOT HDD Storage of the system software, Storage of the image data for BOX/FAX function Capacity: 20GB USB port USB 2.0 interface Ethernet port Ethernet interface (10/100BASE-T) Main Controller PCB Jack No. Role J1003 SDRAM connection slot J1004 SDRAM connection slot J1005 Fax connector (2 lines) J1010 BootROM connection slot J1013 Riser board connection slot J1014 Scanner DDI J1017 USB port J1018 Control panel connector J1020 Power supply connector J1026 Hard disc connector J1029 Printer DDI J1030 Fax connector (1 line) J1061 Ethernet port(10/100BASE-T) Flow of the image data Purpose: To learn about how the image data flow in the main controller. 　 　 1. Outline The main controller handles most of the image processing in this copier. The main controller is divided into the following three main blocks. 1) Reader input image processing block 2) Compression/Decompression/Editing processing block 3) Printer output image processing block Let’s learn each block next. 　 　 2. Reader input image processing block In this block, image processing of the data sent from the reader unit is done. The image data read in the reader unit are converted in this block from 8bit image density signal (multilevel) into 1bit image density signal (binary), which is most suitable for printing. See the data flow in this block below. 3. Compression/Decompression/Editing processing block In this block, the image data sent from reader input image processing block are compressed, decompressed and edited.  The image data, which are binarized in the reader input image processing block, are converted to suitable data based on the information, such as density, magnification or page layout, set on the control panel. See the data flow in this block below. 4. Printer output image processing block In this block, the image data sent from compression/decompression/editing processing block are processed and sent to the DC controller. The image data density is adjusted appropriately and the data resolution is converted by smoothing. See the data flow in this block below. 4. Printer output image processing block In this block, the image data sent from compression/decompression/editing processing block are processed and sent to the DC controller. The image data density is adjusted appropriately and the data resolution is converted by smoothing. See the data flow in this block below. Thickening processing is to thicken thin lines forcefully so that the printed line cannot fade to disappear, for instance, when it is reduced-printed. 　 Service Tasks ○Purpose: To learn about what the service person should do in order to maintain the product quality. ●Outline The works service person does concerning image processing system are shown in the below table. You can see the concrete description by clicking each item. 　 Item Content 1 Parts replacement The work service person must do after replacing parts. 2 Maintenance service The work service person does in maintenance service. 3 Troubleshooting The measures service person takes when service errors or simple image failures are occurred. 4 Important instructions for servicing work The things service person must not do in servicing work. 1. Parts replacement Necessary works to replace parts are as follows. ■Main controller PCB When the main controller PCB is replaced, remove following parts from the demounted main controller PCB and mount them on new PCB. 1) Boot ROM 2) HDD 3) SDRAM 4) Counter memory Do not replace the HDD or main controller unless it is damaged because user setting information or used data is written in them.     2. Maintenance service N/A 　 　 3. Troubleshooting Refer to the chapter of Self-diagnosing in the service manual of the iR4570/3570/2870/2270 series. 　 　 4. Important instructions for servicing work N/A 1. Part Replacement The following parts require adjustment in service mode or counter clearing after part replacement. Their adjustment procedures are as follows. ■Contact Image Sensor (CIS) Unit After replacing the CIS unit, enter a number described on the label on the CIS unit to the following service mode item. 　∙COPIER > ADJUST > CCD > MTF-MG 　 ■Reader Controller PCB A. Handling before replacing the reader controller If the ADF is already attached, output P-PRINT in service mode before replacing the part. 　∙COPIER > FUNCTION > MISC-P > P-PRINT 　 B. Handling after replacing the reader controller 1. Reader controller-related adjustment Follow the steps below. 1) Download the latest system software (R-CON) using SST. 2) Clear RAM in service mode. Then, turn the main power OFF and ON. 　　∙COPIER > FUNCTION > CLEAR > R-CON 3) Enter values of the items below in service mode. a. Values on the service label (inside the reader left cover) a-1. CIS reading position adjustment (fixed reading) 　　∙COPIER > ADJUST > ADJ-XY > ADJ-X 　 a-2. Position adjustment in the main scan direction (fixed reading) 　　∙COPIER > ADJUST > ADJ-XY > ADJ-Y 　 a-3. Shading position adjustment (fixed reading) 　　∙COPIER > ADJUST > ADJ-XY > ADJ-S 　 a-4. MTF value in the main scan direction 　　∙COPIER > ADJUST > CCD > MTF-MG 　 If a value of COPIER > OPTION > BODY > CCD-LUT is other than 0 before the reader controller PCB is replaced, it is necessary to set a number other than 0 again and perform the following adjustment using the D-10 chart (RY9-9129-000). 　∙COPIER > FUNCTION > CCD > LUT-ADJ2 　   2. ADF-related adjustment The machine stores ADF-related service data in the reader controller RAM. Therefore, the ADF must be adjusted when the reader controller is replaced or the RAM is cleared. Enter values of P-PRINT that has been output in the following service mode items. a. Position adjustment in the main scan direction (stream reading) 　　∙COPIER > ADJSUT > ADJ-XY > ADJ-Y-DF 　 b. Document stop position adjustment 　　∙FEEDER > ADJSUT > DOCST 　 c. Document feed speed (scaling) adjustment 　　∙FEEDER > ADUST > LA-SPEED 　 Perform adjustment using the following items. a. Tray width adjustment 　　∙FEEDER > FUNCTION > TRY-A4 　　∙FEEDER > FUNCTION > TRY-A5R 　　∙FEEDER > FUNCTION > TRY-LTR 　　∙FEEDER > FUNCTION > TRY-LTRR 　 b. CIS reading position adjustment (stream reading) 　　∙COPIER > FUNCTION > INSTALL > STRD-POS 　 c. White level adjustment 　　∙COPIER > FUNCTION > CCD > DF-WLVL1 　　∙COPIER > FUNCTION > CCD > DF-WLVL2 　 After the above adjustment items are all ended, store the P-PRINT [1] that has been output in the service bookcase, and dispose of the previous P-PRINT. 　 　 2. Maintenance Service Cleaning of the copyboard glass and the ADF document reading area. Use silicone oil (FY9-6013-000) and cleaning paper (FC5-4430-000) to clean the copyboard glass. Take the steps below. 1) Wipe the reading glass with dry cleaning paper. 2) Push the silicone oil bottle 2 or 3 times to moisten the cleaning paper. 3) Apply silicone oil to the reading glass with the cleaning paper. Silicon oil must be applied evenly at this time. 4) Use a fresh and dry face of the cleaning paper (i.e., the area where silicone oil is not moistened) to wipe the reading glass.

3. Troubleshooting

■White/Black streaks

The copyboard glass or/and the standard white plate gets soiled. Clean the parts.

∙Copyboard glass: Follow the steps described in [2. Maintenance Service] to clean.

∙Standard white plate: Wipe the white plate using alcohol or a cloth moistened with water, and then wipe the plate with a dry cloth.

　

　

4. Points to note on servicing

When the CIS unit is moved with hands, do not hold the CIS unit directly but hold the carriage belt.