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SERVICE MANUAL
CODE: 00ZAL840//B1E
BASIC MANUAL
DIGITAL COPIER
MODEL AL-800/840
CONTENTS
[ 1 ] OPERATING PRINCIPLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
2. Outline of operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
A. Paper path and imaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
B
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[1] OPERATING PRINCIPLE 1 – 1 1. Block diagram SCANNER (READING) SECTION Control signal, detection signal, DOCUMENT drive signal, control data line COPY LAMP Image data signal line SCANNER MIRROR LENS CCD LIGHT QUANTITY SCANNER HOME MOTOR POSITION SENSOR Image (light) SENSOR Power line Paper path line COPY LAMP A/D OPERATION PWB CONTROL PWB CPU ASIC MEMORY ONVERTOR LAMP (LED) ICU PWB HOST(PC) KEY MEMORY ASIC FAN MOTOR MCU (PCU) PWB SCANNER (WRITE) SECTION LASER DIODO LASER BEAM SENSER MOTOR SC
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Scanner (reading) section Scanner (writing) section Fusing/paper exit section Paper feed section Image process section The operations of this section are composed of five processes; ex- Scanner (read) section posure, development, transfer, separation, and discharge. In this section, the copy lamp (cathode ray tube, Xenon lamp) radiates light onto a document, and the reflected light is detected by The OPC drum is used as the photoconductor drum, and one-com- the image sensor (CCD element) to con
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2. Outline of operations A. Paper path and imaging Paper is fed, transported, and discharged through the path indicated with the arrow in the figure below. 1) Paper feed (Paper on the paper tray is fed to the transfer section by the paper feed roller.) 2) Image transfer (The toner image on the photoconductor is trans- ferred onto the paper by the transfer roller.) 3) Fusing (The toner image on the paper is fused by the heat roller and the pressure roller.) 4) Paper exit (The paper is discharged
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(2) Printer mode P1) Print data (compressed data) are sent from the host. (Image data (Data 1 – 8) P2) Print data are developed by the ASIC and the line memory and converted into the full dot image data and sent to the data select section. (Image data)(VIDEO) P3) The data are sent through the data select section to the scan- ner (writing) section. (image data) (V DATA) DATA FLOW DIAGRAM P2 P1 C2 C3 ICU PWB ASIC image data (VIDEO) image data I/F (Data1~8) MCU PWB CCD PWB Image process ASIC DRAM C
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3. Operations of each section A. Paper feed, paper transport section (1) Outline The paper feed tray contains about 200 (250) sheets of paper. The paper is passed to the transfer section by the paper feed roller. The paper feed operation is controlled by the paper feed roller clutch and the paper feed roller clutch solenoid. The paper feed clutch employs the mechanical spring clutch. Paper mis-feed and paper jam are detected by the paper empty sensor and the paper entry sensor. The paper size (w
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Parts No. Note Code Signal name Name Type Function/operation Active condition 1 PE SENSOR PEMP IN Paper empty Photo Detects paper on the paper tray. LOW (0V) when detector transmission paper is detected. sensor 2 Paper guide Adjust the paper width. 3 Paper feed tray Sets the print paper. (Capacity: XXX sheets) 4 Paper release Put this lever straight to set lever paper to release paper feed. Put this lever down to enable paper feed. 5 PUS PUS Paper feed clutch Controls (on/off) the main motor sol
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(3) Operation a. Block diagram MCU(PCU)PWB High voltage power PWB +24V CN805 ASIC Paper pickup 1 +24V PUS solenoid (IC8) 2 PUS MEN CN804 1 MA MMT0 2 MA- Motor Main motor driver MMT1 3 MB 4 MB- CPU (IC5) +5V PIN Paper entry PD801 roller Paper feed roller +5V CN7 1 +5V POUT- Paper exit 2 POUT roller PD802 3 GND LSU PWB +24V CN9 CN601 Paper empty PE roller 9PE 9PE PD601 b. Operation * Paper release lever * The main motor is a 4-phase stepping motor of 2-phase excite- ment bipolar system, which s
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(Paper release operation) (Paper fixing operation) Notch When the paper release lever is pushed down, the paper release lever arm pushes the lock lever arm in the direction of arrow (A). Lower frame By the above operation, the rotating disk is lifted and the paper is pushed by the paper feed roller. If printing is made without pushing down the paper release lever, the Lock lever arm lock lever arm is pushed by the paper feed roller gear boss in the direction of arrow (A) and the paper feed tray
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B. Scanner (reading) section (1) Outline In this section, the copy lamp (Xenon lamp) radiates light onto a document, and the reflected light is detected by the image sensor (CCD element) to convert into electrical signals (analog signals), which are sent to the MCU PWB. Paper feed roller Separate sheet The paper feed roller is of circular form, and double paper feed is prevented by the separate sheet. Paper feed clutch lever Clutch R sleeve The paper feed clutch lever is provided to prevent the
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(2) Major parts 10) 11) 1) 2) 4) MHPS 4) MHPS 6) CCD SENSOR 8) SL SENSOR 5) 3) 2) 7) 4) MHPS 10) 8) SL SENSOR 7) 6) CCD SENSOR 9) 11) 9) 5) 3) Parts No. Note Code Signal name Name Type Function/operation Active condition 1 Scanner lamp Drives the scanner lamp. control PWB Maintains the lamp light quantity at a constant level. 2 Scanner drive wire Transmits the scanner motor power to the scanner unit. 3 Scanner motor Drives the scanner unit. 4 MHPS MHPS Scanner home Photo Detects the scanner home
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(3) Operation a. Wiring diagram MCU(PCU) PWB IC112 CCDD0 GND 1 1 D-GND ASIC CCDD1 A-GND 2 2 A-GND CCDD2 CCDOUT 3 3 CCDOUT IC8 CCDD3 A/D A-GND 4 4 A-GND CCDD4 5V A5V 5 5 A5V CCDD5 5V 5V 6 6 5V CCDD6 12V 7 7 12V 12V CCDD7 GND 8 8 D-GND f1 9 9 f1 GND 10 10 D-GND f2 11 11 f2 CCD UNIT GND 12 12 D-GND SH- 13 13 SH- GND 14 14 D-GND RS 15 15 RS GND 16 16 D-GND SP 17 17 SP GND 18 18 D-GND CP 19 19 CP GND 20 20 D-GND NC 21 21 NC GND 22 22 D-GND RAMP UNIT CN2 CLCNT 1 CFL-H 2 3 4 FGND 5 PDA 6 PDK INVE
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* CCD unit * Scanner home position sensor Images (light) is converted into an electrical signal (analog signal) by The scanner home position sensor senses the scanner position. The the CCD. copy image position control is performed by the sensing timing of this sensor. The image signal read by the CCD is converted into a digital signal b the A/D convertor in the MCU PWB and outputted to the ASIC, where * Zooming the image is processed. Zooming is performed by changing the copy magnification ratio
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Parts No. Note Code Signal name Name Type Function/operation Active condition 1 SYNC SYNC IN Laser beam sensor Bin diode Detects the laser beam position. LOW (0V) when By this signal the left image print laser beam is start position is controlled. detected. 2 No. 1 mirror 3 No. 3 mirror Leads the laser beam to the OPC drum. 4 Second cylindrical Corrects the laser beam lens deflection by variations in the scanning mirror angle. Corrects the optical section dirt. 5Fθ mirror (No. 2 Corrects the las
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The scanning mirror is a 6-surface mirror. Six lines are printed for one rotation of the scanning motor. Laser beams reflected by the scan- ning mirror are passed to the curved mirror by the No. 1 reflection mirror. Before reaching the curved mirror, the laser beams enter the laser beam sensor on the start position detection PWB to make horizontal synchronization (generating SYNC signal). The laser beams from No. 1 reflection mirror are arranged to be parallel beams by the curved mirror and pass
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(2) Image forming process diagram Scanning Lens Laser diode mirror High voltage No. 1 - circuit No. 3 mirror Main charger Exposure brush Toner Cleaning, charging Development, residual toner collection High voltage Discharging Discharging circuit brush Development High voltage roller circuit Paper exit Fusing Separation Transfer Paper feed roller Paper tray Paper Separation electrode Transfer charger roller Heat roller, pressure roller High voltage circuit Heater lamp The operation of this secti
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(3) Major parts a. Photoconductor section 1) 5) 6) 3) 5) 4) 2) 1) Parts No. Note Name Type Function/operation 1 OPC drum OPC Forms latent electrostatic images. 2 OPC drum earth electrode Connects the OPC drum aluminum layer and the earth (high voltage PWB). 3 Main charger electrode Connects the main charger output (high voltage PWB) and the main charger brush. 4 Discharge brush Discharges (lower the potential of) the OPC Japan only drum surface. 5 Main charger brush Charges the OPC drum. 6 Toner
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b. Development section 5) 2) 1) 7) 8) 5) 1) 3) 3) 6) 4) 4) 8) 5) 1) Parts No. Note Name Type Function/operation 1 Developing roller Attaches toner to the latent electrostatic images on the OPC drum to convert it into a visible image. 2 Developing doctor Controls toner quantity on the developing roller and charges toner. 3 Developing bias Connects the developing roller and the bias electrode voltage output (high voltage PWB). 4 Potential control Connects the developing roller and the bias electro
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c. Transfer/separation section 1) 3) 4) 3) 5) 2) 1) 4) Parts No. Note Name Function/operation 1 Transfer roller Transfers toner images on the OPC drum onto the paper. 2 Transfer roller Connects the transfer roller and the transfer voltage output (high voltage PWB). electrode 3 Pressure spring Applies pressure to the transfer roller, paper, and the OPC drum to improve transfer efficiency. 4 Separation electrode Reduces paper charging potential to facilitate separation of paper. 5 Earth electrode
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(4) System diagram Laser beam Scanning mirror Laser unit MCU PWB No. 1 - 4 mirror Image data Toner High voltage power PWB –310V/+200V selection Main DC –310V DC-310V charger Developing brush roller DC +200V Photoconductor drum DC +3.5KV DC-200V AC600V(P-P) Discharge brush DC –850V Paper Transfer DC-850V charger AC600V(P-P) roller Separation electrode DC+500V (5) Operation a. Wiring diagram MCU(PCU) PWB CN6 3 GND TSIN Toner sensor 2 TSIN +5V 1 High voltage power PWB ASIC Charger brush (IC8) MCON
