Sharp Printer AL-840 User's Manual
Contents
1. 68 Charger brush Eo 1801 lt transformer CB ischarge brus 24VP I i 1 Driveri C801 24VP l Separation electrode TC Bias ON E a806 0807 gt TC T802 Transfer charger roller transformer l 100V 4 DC Supply roli CPU PWNSIN IC5 i Developing roller Earth sheet 1 19 b Major parts functions and operations Developing Toner seal roller Doctor Discharge brush Main charger brush Toner seal Transfer charger roller Toner stirring plate Toner supply roller Separation electrode Phot conductor drum Discharge Earth sheet lt 1 gt Photoconductor drum unit The photoconductor surface is charged and latent electrostatic im ages are formed then visible images are formed with toner 1 Photoconductor drum Latent electrostatic images are formed and visible images are formed with toner An OPC Organic Photo Conductor drum is used The OPC drum surface is negatively charged by the main charger brush When laser beams are radiated on the OPC drum the electric resis tance at the radiated area is reduced to generate an electric charge inside the OPC drum As a result the charges on2. The paper release lever is used to fix or release paper To release paper pull the lever toward you as shown in the figure below To fix paper push the lever forward The lever mechanism is as shown below Paper release operation Notch Lock lever arm Lock lever Spring Paper feed tray Paper release vA Paper feed clutch Clearance The lock lever arm is always pressed onto the paper release lever by the spring When the paper release lever is pulled toward you the lock lever arm is brought into contact with the lower frame so that the paper pressure plate is fixed at the paper release position Under this condition a clearance is provided between the paper feed roller and the paper feed tray as shown in the figure below and the paper is released Paper release lever Sub release lever Lock lever arm Paper feed roller gear Paper release lever Paper feed clutch Paper fixing operation When the paper release lever is pushed down the paper release lever arm pushes the lock lever arm in the direction of arrow A 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 is pushed by the paper feed roller gear boss in the direction of arrow A and the paper feed tray is pushed to fix the paper Paper feed roller pap
3. OPC drum surface potential V y Charging cleaning Laser J beams Dark area potential 1 1 Toner attraction Developing potential bias Light area potential Exposure Residual toner Transfer Charging collection Development r Time OPC drum rotating angle 1 24 lt 2 gt OPC drum surface potential and developing bias voltage during developing 310V OPC drum surface potential V During developing mim Dark area potential End aaa a a a n Se es eS Sh Developing bias Light area potential Time OPC drum rotating angle E Fusing paper exit section 1 Outline Toner attracted to the paper in the transfer section is fused by heat and pressure of the heat roller The heat roller is of thin aluminum roller which is high heat conductivity minimizing the warm up time The heat roller surface temperature is detected by the fusing temperature sensor to maintain the fusing temperature at a constant level 160 155 C 2 Major parts IN ee aj lt p Signal name Name Function operation Active condition Heat roller Heats toner on the paper and LOW 0V when fuses onto the paper paper is detected POUT IN Paper exit detector Photo transmission Detects paper exit sensor RTH IN Fusing temperat
4. PSIZE_IN DPAGE VIDEO VSYNC PRSTT ICU PWB RESET DREADY DCRDY ERROR SCLK SYNC HERMISTOR RTH_IN OPCLK OPLATCH OPPSW OPDATA SELIN1 2 30PKIN1 2 ICU PWB Print data from the host PC are developed by the ASIC and the line memory DRAM to converted into full dot image data which are then outputted to the data select section in the MCU PWB The machine status data from the MCU PWB are outputted tot he host PC In addition the ASIC controls the parallel I F VFMOUT ICU PWB TO PC IC202 GATE ARRAY TO PC Operation PWB Status data from the MCU PWB are converted into the lamp and lamp display by the display controller The key operations are con verted into key data signals and outputted to the MCU PCU PWB MEN MMTO 1 MCON HL TC BIASON PUS PR PWMSIN FAN Faw MOTOR HGH VOLTAGE PWB VOLTAGE PWB k 29 p 15 OPERATION PWB BLOCK DIAGRAM LAMP VALUE DISPLAY LED DISPLAY CONTROLLER DRIVER IC901 MCU PWB DECODER IC902 High voltage power PWB This PWB supplies the high voltage used in the image process sec tion Main charger developing bias transfer charger It also includes the driver for the main motor The power output is controlled by the control signals from the MCU PCU PWB Copy lamp control PWB The copy lamp light quantity is controlled so that the necessary quan tity
5. Zenor diode Maintains the potential between the developing roller and the toner stirring roller at a constant level Toner seal Shields toner from leaking outside the developing unit Potential control sheet Maintains the developing roller potential at a constant level ee aN phe ay zs Sosy ay li D N Y xe ra Q c Transfer separation section Parts Name Function operation Transfer roller Transfers toner images on the OPC drum onto the paper Transfer roller electrode Connects the transfer roller and the transfer voltage output high voltage PWB Pressure spring Applies pressure to the transfer roller paper and the OPC drum to improve transfer efficiency Separation electrode Reduces paper charging potential to facilitate separation of paper Earth electrode Connects the separation electrode and the earth high voltage PWB 1 18 4 System diagram Laser beam Scanning mirror Laser unit MCU PWB No 1 4 mirror Image data High voltage power PWB 310V 200V selection DC 310V Developing DC 310V roller Photoconductor drum DC 3 5KV pee AC600V P P Transfer charger roller DC 850V AC600V P P Separation electrode DC 500V 5 Operation a Wiring diagram High voltage power PWB
6. In the cleaning mode a voltage of 850 V is applied If there is toner on the transfer roller the toner is attracted to the OPC drum Step 5 Paper separation Paper is separated from the OPC drum Aluminum layer Drum base ooo a J d See ooo Old a Separation electrode Transfer roller An electric force is acting between the paper which is positively charged in the transfer process and the OPC drum which is negative ly charged Positive charges on the paper are moved to the aluminum layer through the separation electrode to reduce the potential dif ference between the OPC drum and the paper By this operation the paper can be easily separated from the OPC drum 1 23 Step 6 Discharging The drum surface is discharged by the dis charge brush to facilitate cleaning Residual toner can be easily collected by the main charger roller Step 7 Cleaning Residual toner on the OPC drum is removed Main charger brush AC600V P P Residual toner OPC drum DC 850V Discharge brush Aluminum layer Drum base DC 500V The main charger brush is of roller shape and is rotating The main charger brush stirs residual toner and paper dust on the OPC drum The residual toner and paper dust are evenly distributed and put on the OPC drum again to be sent to the developing roller 0 OPC drum surface potential lt 1 gt OPC drum surface potential shift in printing 850V 310V
7. Toner supply roller The toner supply roller transports toner to the developing roller 4 Toner stirring plate The toner stirring plate stirs toner in the developing unit to transport toner to the developing roller smoothly 5 Toner seal The toner seal prevents toner from leaking outside the developing unit 6 Discharge Earth sheet The discharge sheet maintains the developing roller surface potential at a constant level lt 3 gt Transfer charger roller The transfer charger roller is made of urethane and its electrical resistance is considerably high It is flexible and pressed onto the OPC drum A high voltage of AC600V P P is applied to DC 3500V Paper transported from the paper feed section is charged positively and negatively charged toner on the OPC drum are transferred onto the paper During cleaning a voltage of 850V is applied lt 4 gt Separation electrode The separation electrode is connected to the drum earth This dis charges paper charged positively in the transfer section to reduce potential difference with the OPC drum reducing electrostatic attrac tion power between paper and the OPC drum facilitating paper separation lt 5 gt High voltage unit The high voltage is made by the invertor system and is supplied to the main charger unit the transfer unit and the developing roller 6 Actual image forming process Step 1 Cleaning charging Residual toner on the OPC drum is s
8. PWB I CN805 D ASIC Lol A Paper pickup IC8 solenoid gt E MMTO Motor 12 Ma 4 MB CPU i IC5 5V i E lt Paper entry roller Paper feed eee ee er ae eae roller Paper exit roller a es Se eee lt lt lt lt lt lt lt lt lt 2 3 0 9 CN601 Paper empty fe PE fe PE roller l b Operation Paper release lever x The main motor is a 4 phase stepping motor of 2 phase excite ment bipolar system which serves as the drive source of the paper Paper release Paper fixed feed and transport system The pickup solenoid operates on 24V and turns ON OFF paper feed operation The following sensors are used Paper empty sensor transmission photo transistor It is installed on the LSU PWB and is used to detect whether there is paper in the paper feed tray or not Paper entry sensor Transmission photo transistor This sensor is used to detect the paper feed timing of next paper in pre feed and to make synchronization between paper transport and image forming on the drum It is also used to detect a paper jam Paper exit sensor Transmission photo transistor This sensor is used to detect that paper is discharged It is also used to detect a paper jam
9. image are controlled 8 Paper feed roller Feeds paper 9 PAPER SIZE PAPER SIZE Paper width Mechanical Detects the paper width This LOW 0V when SW IN detector switch Micro signal controls the laser beam the max width is switch radiation area detected 10 Paper pressure Presses paper onto the paper plate feed roller 11 Paper pressure Presses paper onto the paper spring feed roller 12 Paper separator Separates paper in paper feed operation 13 Paper feed clutch Mechanical Controls ON OFF of the paper spring type feed roller The paper feed roller clutch is driven by the paper feed clutch solenoid and the main motor 14 Paper feed clutch Driven by the paper feed clutch lever solenoid to control ON OFF of the paper feed clutch Prevents against reverse rotation of the paper feed roller 15 Paper feed clutch Links the paper feed roller and joint the paper feed roller clutch 16 Paper feed clutch Controls ON OFF of the paper sleeve feed roller The paper feed roller is driven by the paper feed clutch solenoid and the main motor 17 Paper feed clutch Transmits the paper feed clutch spring rotation to the paper feed clutch sleeve 18 Paper feed clutch Transmits the main motor power gear to the paper reed roller 19 Paper separater Applies a proper pressure to the spring paper separater 3 Operation a Block diagram MCU PCU PWB i High voltage power
10. laser beams So the OPC drum surface is kept negatively charged to maintain a high potential As a result latent electrostatic images are formed on the OPC drum Laser beam Non exposure area Exposure area Aluminum layer Drum base Aluminum layer Drum base Step 3 Development Toner is attached to the latent electrostatic images formed on the OPC drum Doctor Developing roller Exposure area Exposed by laser beams Non exposure area Not exposed by laser beams x 7 Aluminum layer Drum base CGL CTL Toner enters between the developing roller and the doctor and a thin layer of toner a certain fixed amount is formed on the developing roller by a pressure applied to the doctor Toner is negatively charged by friction when passing between the developing roller and the doctor When the OPC drum surface area where there is no charges be cause of exposure of laser beams is brought into contact with the developing roller toner is moved from the developing roller to the OPC drum surface The principle of the process is as follows A bias voltage of 310V is applied to the developing roller Toner which is charged by potential difference between the bias voltage and the OPC drum surface potential is attracted to the OPC drum surface positively charged b 22 At that time the potential of the OPC drum surface where there is no charge by exposur
11. of light is provided even when conditions of the scanner reading section are changed The copy lamp drive voltage is controlled by the output level of the light quantity sensor in the scanner reading section Control is made with the control signals from the MCU PCU PWB Power PWB The power PWB outputs DC power voltages 24V 5V 3 3V 12V and drives the heater lamp SHARP COPYRIGHT 1998 BY SHARP CORPORATION All rights reserved Printed in Japan No part of this publication may be reproduced stored in a retrieval system or transmitted In any form or by any means electronic mechanical photocopying recording or otherwise without prior written permission of the publisher SHARP CORPORATION Printing Reprographic Systems Group Quality amp Reliability Control Center Yamatokoriyama Nara 639 1186 Japan 1998 October Printed in Japan
12. the A D convertor in the MCU PWB and outputted to the ASIC where the image is processed Scanner motor The scanner unit is driven by the scanner drive motor C Scanner writing section 1 Outline In this section the dot image data sent from the MCU PWB are converted into laser beams ON OFF which are scanned to form latent electrostatic images on the OPC drum It is composed of the laser beam generating section where dot image data signals are converted into laser beams ON OFF the laser beam correction section the laser beam scanning section and the laser beam detect ing section The major parts and their functions are described in the following 2 Block diagram Scanning motor drive signal PMD PMCLKk Laser diode No 1 control circuit Alens i No 2 1reflection mirror a mirror Laser beam sensor 2 lens iden Motor mirror mirror No 3 reflection mirror lt Signal Laser beam 3 Major parts 42 Scanner home position sensor The scanner home position sensor senses the scanner position The copy image position control is performed by the sensing timing of this sensor Zooming Zooming is performed by changing the copy magnification ratio in the sub scanning direction or changing the scanning speed The copy magnification ratio in the main scanning direction is changed by the software in the ASIC 2 1 SYNC Parts Sign
13. the OPC drum are removed This process is used to form latent electrostatic images CTL a Charge Transfer Layer CGL Charge Generation Layer OPC layer Aluminum layer 2 Main charger brush The main charger brush charges the OPC drum surface It is com posed of brush textures and of a roller shape A high voltage of AC 600V P P is applied to DC 850V to charge the brush The main charger brush is in contact with the OPC drum By supply ing electric charges to the OPC drum the OPC drum is charged to about 850V 3 Toner seal The OPC drum has two toner seals The toner seals are used to prevent residual toner on the OPC drum from leaking outside 1 20 lt 2 gt Developing unit Visible images are formed with toner over the latent electrostatic images formed on the OPC drum surface Toner is filled in the developing unit 1 Developing roller The developing roller is made of urethane and it has considerably high electrical resistance It is flexible and pressed onto the OPC drum Toner is attached to the latent electrostatic images on the OPC drum to make visible images A voltage of DC 310V 200V is applied to the developing roller A voltage of 310V is applied when develop ing A voltage of 220V is applied when cleaning 2 Doctor The doctor is pressed onto the developing roller It adjust the toner quantity on the developing roller surface The doctor is made of a conductive material 3
14. the photoconductor drum Function The laser power is controlled by the APC Auto Power Control circuit In addition the paper empty sensor is provided The laser diode radiates 780nm infrared semiconductor laser beams under control of the laser control PWB The collimator lens arranges laser beams radiated from the laser diode to be parallel beams and converges them on the photoconductor drum Part name Laser diode Collimator lens No 1 cylindrical lens Adjusts the direction of the laser beams Scanning motor Scanning mirror Used to rotate the scanning mirror Started by the drive signal PMD_ from the PCU The RPM is controlled by the clock signal PMCLK_ The motor RPM is 11811 RPM The scanning mirror is a6 surface mirror and it reflects laser beams By this operation 6 lines of printing is made for one rotation of the scanning motor No 1 mirror This mirror reflects laser beams to the curved mirror Laser beam sensor PWB Start position detection PWB Used to detect laser beams to make horizontal synchronization The photo sensor on the PWB detects laser beams to generate SYNC signal No 2 mirror Curved mirror Laser beams are scanned by the scanning mirror But the dot interval of laser beams radiated onto the photoconductior differs at the center and at the corners This mirror corrects this difference to provide even dot interval of laser beams For t
15. OPY LAMP OPERATION PWB CONTROL PWE A D ONVERTOR m I I I I I LAMP LED I I I I I I MOTOR MAIN MOTOR DRIVER HIGH VOLTAGE POWER PWB FUSING PAPER EXIT SECTION TEMPERATURE HEATER LAMP SENSOR PRESSURE ROLLER PRINT PWB HEAT ROLLER PAPER EXIT POWER PWB MEMORY ASIC MCU PCU PWB LASER DIODO LENS ee MIRROR MEMORY ASIC ICU PWB SCANNER MOTOR PARALLEL I F SCANNER WRITE SECTION LASER BEAM SENSER IMAGE PROCESS SECTION MAIN CHARGER DEVELOPING PHOTOCONDUCTOR ROLLER SEPARATION ELECTRODE SCANNER PAPER FEED SECTION PAPER FEED ROLLER CLUTCH PAPER WIDTH DETECTOR PAPER EMPTY DETECTOR PAPER ENTRY DETECTOR PAPER AC POWER J IdIONIYd ONILVYsdO 1 Scanner reading section Fusing paper exit section 4 Paper feed section Image process section Scanner read section In this section the copy lamp cathode ray tube 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 wh
16. SHARP SERVICE MANUAL CODE 00ZAL840 B1E BASIC MANUAL DIGITAL COPIER movEL AL 800 840 CONTENTS Ss a Geet da eves ee eas Scere t atraer ghee ah apres te eae ee 1 1 1 Block diag ram 1 1 2 Outline of eres 2 1 3 A Paper path and gt s riti 1 3 B Image process and dataflow eee 1 3 3 Operations of each section cccccececeeeee ee 1 5 A Paper feed paper transport Secon 1 5 B Scanner reading section lt 1 9 Ba ee eb ees eae ese eenes 1 12 MD Image process SeclOn A l a aerieni rrinin 1 14 LE Fusing paper exitsection cccccccccececececeeevees 1 25 E Drive section II IZID o on 1 27 G Electrical section u uouo daadaa Laaa LaaLa aaa 1 28 Parts marked with A is important for maintaining the safety of the set Be sure to replace these parts with specified ones for maintaining the safety and performance of the set This document has been published to be used SHARP CORPORATION after sales service only The contents are subject to change without notice 1 Block diagram DOCUMENT lt 4 Image data Signal line C ore 7 SCANNER HOME LIGHT QUANTITY POSITION SENSOR SENSOR Image light Power line Paperpath line _ _ _ A MIRROR C
17. YNC SYNC i l l l l ICU PWB b Operation The APC circuit is started by the APCSTT signal sent from the MCU PCU PWB and laser diode is turned on off according to the VIDEO signal The laser diode is turned on when the VDATA signal is HIGH When the laser diode is turned on 780nm infrared semiconductor laser beams are radiated from the laser diode and arranged to be parallel beams by the collimeter lens and focused to the photocon ductor drum by No 1 cylinder lens and sent to the scanning mirror Rotation of the scanning mirror is controlled by the scanning motor to scan laser beams 1 13 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 passed to No 3 reflection mirror The laser beams reflected by No 3 reflection mirror are passed through No 2 cylinder lens to the photoconductor drum No 2 cylinder lens corrects deflection of laser beams due to varia tions in the duplex scanning mirror installing angle and leads the stable laser beams for each line to
18. al name Name Type Function operation Active condition 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 No 1 mirror No 3 mirror Leads the laser beam to the OPC drum Second cylindrical lens Corrects the laser beam deflection by variations in the scanning mirror angle Corrects the optical section dirt F mirror No 2 mirror Corrects the laser beam form and pitch Scanning mirror rotation mirror Scans the laser beam and performs imaging No 1 cylindrical lens Adjust the direction of laser beam Laser diode 4 Operation a Wiring diagram MCU PCU PWB CPU IC5 PMCLK ai SAMP 2 CN601 3 termina 3 regulator 1 Generates laser beam Controls ON OFF for imaging LSU PWB start position detection PWB i Laser beam detection PWB IC603 GND VDATA ASI LEND e A ar SAMP 2 pecs H E VSYNC PRSTT dene E Se EE EEEE E E E PESE l mae ee ee el lt 3 01203 SDATA ASIC LEND 6202 PRSTT VS
19. built in the high voltage power PWB 2 Major parts Parts Name Type Function operation Main motor Stepping motor 24V Drives the paper feed section the paper transport section the fusing section and the image process section Paper feed section drive Transmits the main motor power to the gear paper feed section Imaging process Transmits the main motor power to the fusing section drive gear imaging process section and the fusing section 3 Wiring diagram MCU PCU PWB High voltage power PWB ASIC Paper feed roller ace MEN Heat roller Pressure roller Main motor Paper exit roller Developing cartridge Photoconductor cartridge Transfer roller 27 G Electrical section 1 Block diagram MCU PCU PWB Image process ASIC CCD PWB CCD Amplifier DRAM DRAM DRAM 16Mbit 16Mbit 16Mbit Motor driver Operation panel PWB Display lamp Data select LSU unit gt Paper exit sensor Pickup solenoid Laser beam sensor Polygon motor High voltage PWB Paper in sensor Main motor High voltage unit Heat roller Heater lamp fuse Scanner lamp Invertor Power PWB unit fuse a Major sections opera
20. e heat roller surface temperature at the optimum level The heat roller surface temperature is controlled to 160 155 C in the print mode and to 80 C in the pre heat mode As a protective measure in case of abnormally high temperature in the fusing section two temperature fuses are provided in the heater lamp power line The heater lamp is lighted by the AC power source High voltage power PWB l Heat roller Heater lamp Pressure roller Thermistor Temperature fuse 132 C Temperature fuse 187 C Separation pawl 26 The heat roller is made of aluminum tube coated with teflon to provide a good separation capability A halogen lamp is used as the heater lamp Silicon rubber is used to provide enough pressure A chip type thermistor of good response is used to detect the heat roller surface temperature The temperature fuse 132 C is at tached to the fusing cover When the fusing cover ambient temperature be comes abnormally high this fuse is blown off The temperature fuse 187 C is closely attached to the heat roller When the heat roller temperature becomes abnor mally high this fuse is blown off The separation pawl separates paper from the heat roller mechanically F Drive section 1 Outline The main motor drives the paper feed section the transport section the image process section and the fusing section The main motor drive circuit is
21. e of laser beams is higher than the developing roller potential On the other hand there are negative charges in the OPC drum surface area which is not exposed to laser beams When that area is brought into contact with the developing roller if toner is attached to the OPC drum toner is moved to the developing roller which is in a high potential than the OPC drum As a result unnecessary toner and paper dust on the OPC drum are collected in the developing unit In this operation toner is moved from the OPC drum to the develop ing roller In cleaning operation mode DC 200V is applied to the developing roller and cleaning capacity is further increased Step 4 Transfer Visible images of toner on the OPC drum are transferred to the paper Aluminum surface Drum base OPC drum DARA ceon IES 555 5556 oe Transfer roller DC 3500V AC600V P P Si DC 850V A high voltage of AC60V P P is applied to DC 350V and applied to the transfer roller generating electric discharge between the roller and the OPC drum generating positive and negative charges The positive charges are attracted to the OPC drum which is nega tively charged and put on the paper transported between the transfer roller and the OPC drum The paper therefore is charged positively The negative charged toner on the OPC drum is attracted to the paper which is positively charged and visible images of toner are transferred onto the paper
22. e photoconductor and converted into visible images by toner development The operations of this section are composed of five processes ex posure development transfer separation and discharge The OPC drum is used as the photoconductor drum and one com ponent toner is employed For charging the rotation brush is employed For transfer the roller is employed to eliminate ozone generation In addition t is compact The high voltage required in this section is supplied by the high voltage PWB Fusing paper exit section Toner is fused to the paper in the fusing paper exit section using heat and pressure The heat roller surface temperature is detected by the fusing temperature sensor to maintain the constant fusing temperature 155 C The heater lamp is driven by the power PWB unit Operation PWB The operation PWB displays various information and supplied the key operation signals to the MCU PCU PWB High voltage power PWB The high voltage power PWB outputs the high voltage for the main charger the developing bias and the transfer charger In addition the main motor drive circuit is built into the PWB Main motor The main motor drives the paper feed section the transport section the image process section and the fusing section The main motor drive circuit is built into the high voltage power PWB Copy lamp control PWB The copy lamp light quantity is controlled to provide necessary light quantity ev
23. ed 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 width is detected by the paper size width detector to prevent toner from attaching to the area over the paper width 2 Major parts 2 1 PE SENSOR 9 PAPER SIZE SW 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 OV 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 solenoid drive for the paper feed roller 6 Paper feed When the paper feed lever is put release lever straight this lever releases paper feed solenoid drive This partially reduces stress to the paper feed roller clutch in removing paper 7 PIN SENSOR PIN Paper in detector Photo Detects whether the fed paper is LOW OV when transmission transported to the transfer paper is detected sensor position or not By the timing of this detector signal the relative positions of paper and print
24. en though the conditions of the scanner reading section are changed The copy lamp drive voltage is controlled by the output level of the light quantity sensor in the scanner reading section Power PWB The power PWB outputs the DC power voltages 24V 5V 3 3V 12V and drives the heater lamp 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 to the paper exit tray by the paper exit roller B Image process and data flow 1 Copy mode C1 C2 C3 C4 Images scanned by the image sensor CCD element is con verted into electrical signals analog signals and outputted to the MCU PWB CCD unit Image data outputted from the scanner reading section are converted into digital signals CCDDO 7 Image process area separation filter process gamma correc tion resolution conversion zooming is performed by the ASIC and the line memory SRAM The dot image data the resolu tion of which is converted from 400dpi to 600dpi are sent to the da
25. er feed solenoid Paper feed solenoid Paper feed clutch The paper feed solenoid is used to turn ON OFF the paper feed clutch When the paper feed solenoid is turned on the paper feed roller is rotated paper feed clutch The paper feed clutch is a spring clutch The paper feed roller gear rotation is transmitted to the paper feed roller only in the direction of A That is the paper feed roller is rotated only in the direction of A paper feed direction 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 paper feed roller from rotating reversely When paper feed is not performed the paper feed clutch lever is engaged with the paper feed roller boss gear When removing paper for paper replacement a reverse rotation power is applied to the paper feed roller In this case the paper feed solenoid provides enough power to prevent the paper feed roller from rotating reversely however an excessive stress is applied to the spring clutch which may be damaged Therefore the paper feed clutch lever is used to lock and protect the spring clutch from an excessive stress 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 b
26. his reason it is of curved structure This mirror passes the laser beams reflected from the curved mirror to the photoconductor mirror This lens is used to correct laser beam deflection due to variations in the scanning mirror angle No 3 mirror No 2 cylindrical lens D Image process section 1 Outline This section is composed of the photoconductor section the develop ing section the transfer separation section Images formed by laser beams formed by the scanner Writing section are converted into a latent electrostatic images which are formed into visible images by toner development The toner images are transferred onto paper 1 14 2 Image forming process diagram Scannin g Lens Laser diode mirror No 1 No 3 mirror High voltage circuit Development residual toner collection Development High voltage roller circuit I DS GD e ce I I I m I I Transfer i Paper feed roller Paper tray Paper l I Separation gt 1 electrode ii l lt lt lt lt lt lt lt lt lt i Il L Heat roller Transfer charger roller pressure rollen I I I I High voltage circuit I I Heater lamp The operation of this section are composed of the six processes charging exposure development transfer separation and discharg ing An OPC drum is used as the photocod
27. ich are sent to the MCU PWB MCU ICU PWB The image data from the scanner reading section are converted into digital signals and subject to image process correction etc and converted into dot image data and outputted to the scanner writing section During printing the dot image data from the ICU PWB are outputted to the scanner writing section directly The engine status data are outputted to the ICU PWB The loads motor solenoid etc are controlled according to the sen sor detector signal The above operation is performed by the CPU ASIC and memory ICU PWB Print data compressed data sent from the host are developed and converted into dot image data and outputted to the scanner writing section The engine status data sent from the MCU PCU PWB are outputted to the host PC Scanner writing section In this section the dot image data sent from the MCU PWB are converted into laser beams ON OFF which is scanned to form latent electrostatic images on the OPC drum Paper feed section The paper feed roller feeds paper to the transfer section The paper feed operation is controlled by the paper fed roller clutch and the paper feed roller clutch solenoid Image process This section is composed of the photoconductor section the develop ing section and the transfer separation section The images formed by laser beams in the scanner writing section are formed into latent electrostatic images on th
28. or Leads the document image to CCD No 2 mirror Leads the document image to CCD No 3 mirror 1 10 Leads the document image to CCD 3 Operation a Wiring diagram MCU PCU PWB IC112 CCDDO ASIC Se lt ESS eS O A D 1 E ee a E E 12V 4 GND 10 10 D GND S es aE 13 O P a SOC OC lt SN G 16 B 17 GND 18 fee lt no a RAMP UNIT ae 3 e Pok CLCNT gt CN10 4 PD gt Not used CPU IC5 IC13 SCANER MOTOR DRIVER SCANER H P SENSOR Copy lamp The copy lamp drive voltage corresponding to the sensor output level A cathode ray tube Xenon lamp is used as the light source for CLIN is outputted reading images The copy lamp is driven by the scanner lamp control PWB To maintain the lamp light quantity at constant level the following operations are performed The copy lamp light quantity sensor is provided in the scanner unit to detect the copy lamp light quantity ieii CCD unit Images light is converted into an electrical signal analog signal by the CCD The image signal read by the CCD is converted into a digital signal b
29. ta select section Image data LD The data are passed through the data select section to the scanner writing section Image data V DATA In the multi copy mode image data of one sheet are stored in the DRAM Sharp version only 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 C2 C3 ICU PWB image data VIDEO image data VE lt re mal MCU PWB CCD PWB Image process ASIC Data 8 LSU unit image djita Image Data select KD image data V DATA analog image data C1 SRAM SRAM DRAM DRAM DRAM 16Mbit 16Mbit 16Mbit P 32kbitx8 32kbitx8 SC only SC only SC only C4 3 serial data serial data SDATA OP DATA KIN1 KIN2 Operation panel CPU BUS serial data EEPD y 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 fe
30. tions and functions MCU PCU PWB The CPU controls the engine and the ASIC performs image process Image data analog signals from the scanner reading section are converted into digital signals by the A D convertor and image process area separation filter process gamma correction resolution conver sion zooming is performed by the ASIC and the line memory SRAM The processed data are outputted to the scanner writing section During printing the dot image data from the ICU PWB are received and outputted to the scanner writing section straightly The CPU controls the machine operations according to the key operation sig nals from the operation PWB The loads motor lamp solenoid high voltage power PWB etc are controlled according to the sensors and detectors signals At the same time the machine status data are outputted to the operation section and the ICU PWB Developer cartridge Doctor Developing roller Earth sh 1 28 Transfer roller Main charger roller OPC cartridge Control electrode eet MCU PWB BLOCK DIAGRAM SCANNER MOTOR MRMT0 3 HOME POSITION SENSOR MHPS_IN 8 coD Pwe PWB RS CCDOUT CLCNT APER SIZE SENSOR VDATA LASER PMCLKy POLYGON PMD MOTOR IC5 IC8 CPU ASIC H8S 2350 HG73C025FD PAPER PEMP_IN EMPTY SENSOR PAPE DSRDY RESERR
31. tirred and negative charges are dis tributed evenly on the OPC drum The OPC drum is evenly charged The main charger brush is of roller shape and is rotating The main charger brush stirrs residual toner and paper dust on the OPC drum At the same time a high voltage of AC 600V P P is applied to DC 850V and applied to the main charger brush to make electric dis charge between the roller and the OPC drum to form positive and negative charges The negative charges are attracted to the OPC drum which is positively charged And negative charges are evenly distributed on the OPC drum The OPC drum surface is evenly charged Residual toner and paper dust stirred by the main charger brush are distributed evenly on the OPC drum Main charger brush aceoov Residual toner P P O OPC drum _DC 850V CGL Aluminum layer Drum base Step 2 Exposure Laser beam scanning light corresponding to the print data is radiated onto the OPC drum Positive and negative charges are generated in the CGL of the OPC drum which are radiated with laser beams The positive charges in the CGL are moved to the OPC drum surface and the negative charges are moved to the aluminum layer Therefore positive and negative charges are neutralized in the OPC drum exposed with laser beams and the aluminum layer reducing the OPC drum surface potential On the other hand there is no change in the area which is not exposed with
32. uctor drum Toner is of one component For charging the rotation brush is used For trans fer the roller is used and virtually no generation of ozone It is also compact The high voltage required in this section is provided by the high voltage power PWB 1 15 3 Major parts a Photoconductor section Name Function operation OPC drum Forms latent electrostatic images OPC drum earth electrode Connects the OPC drum aluminum layer and the earth high voltage PWB Main charger electrode Connects the main charger output high voltage PWB and the main charger brush Discharge brush Discharges lower the potential of the OPC drum surface Japan only Main charger brush Charges the OPC drum Toner seal Shield to prevent toner from leaking outside the OPC drum unit 1 16 b Development section 5 Name Function operation Developing roller Attaches toner to the latent electrostatic images on the OPC drum to convert it into a visible image Developing doctor Controls toner quantity on the developing roller and charges toner Developing bias electrode Connects the developing roller and the bias voltage output high voltage PWB Potential control electrode Connects the developing roller and the bias voltage output high voltage PWB Toner stirring roller Lead toner to the developing roller and charges toner
33. ure Thermistor Detects the heat roller sensor surface temperature Temperature fuse 1 Mold Assures safety in overheating Fusing section Temperature fuse 2 Mold Assures safety in overheating Fusing section Heater lamp Halogen lamp Heats the heat roller 100V series 10V 500W 120V series 120V 500W 200V series 230V 500W Pressure roller Applies a pressure to the heat roller and paper to improve fusing efficiency Paper exit roller Discharges paper after fusing Separation pawl Separates paper from the fusing roller mechanically Paper exit roller Discharges paper outside the machine after fusing Pressure spring Applies a pressure to the heat roller paper and pressure roller to improve transfer efficiency 1 25 3 Operation a Wiring diagram MCU PCU PWB POWER SUPPLY PWB Fusing section Temperature fuse Thermistor 4 AC POWER IN 65 HLON HLON ne Gate L d RTH O COMP PR i AMP CN2 GND 15 oi lt 2 2 2 1 lt 2 lt 222 2212 222 2 2 CN801 i i l DRIVER i i i i l b Operation The heater lamp ON OFF is controlled by the detection signal volt age value from the thermistor to maintain th
34. y the image sensor CCD element to convert into electrical signals analog signals which are sent to the MCU PWB 2 Major parts 4 MHPS 4 MHPS 10 8 SL SENSOR 7 6 CCD SENSOR S S Signal name Name Function operation Active condition Scanner lamp control PWB Drives the scanner lamp Maintains the lamp light quantity at a constant level Scanner drive wire Transmits the scanner motor power to the scanner unit Scanner motor Drives the scanner unit Scanner home position sensor Photo transmission sensor Detects the scanner home position By this signal the image scanning operation is controlled HIGH 5V when the home position is detected Lens Transfers the document image to CCD CCD OUT CCD Image sensor Scans the document images photo signals and converts them into electrical signals Digital signal 8Bit Scanner lamp Radiates light to the document to allow the CCD to scan the document images SL SENSOR PDA PDK Scanner lamp light quantity sensor Photo diode Detects the scanner lamp light quantity This signal is inputted to the scanner lamp control PWB to control the scanner lamp drive voltage to maintain a constant level of light quantity Analog signal 0 0 5V No 1 mirr
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