Epson C 2900 Manual
Have a look at the manual Epson C 2900 Manual online for free. It’s possible to download the document as PDF or print. UserManuals.tech offer 1734 Epson manuals and user’s guides for free. Share the user manual or guide on Facebook, Twitter or Google+.
![Page 559
6 - 2 Chapter 6 Principles of Operation
Epson AcuLaser C2900NRevision B
Confidential
1.2 Schematic Diagram for Printing Processes
Outline of printing processes is shown in the figure below.
MiS06002SA
ROS
[(2)Exposure]Drum Cartridge
[(1)Charge]
[(3)Development]
[(4)Transfer]
[(5)Cleaning]
FUSER UNIT
[(6)Fusing]
Transfer ASSY
[(4)Transfer]
[(7)Cleaning]:
Laser beam
: Paper transfer](http://img.usermanuals.tech/thumb/23/100561/w64_c-2900-manual-1509489781_d-558.png "Page 559
6 - 2 Chapter 6 Principles of Operation
Epson AcuLaser C2900NRevision B
Confidential
1.2 Schematic Diagram for Printing Processes
Outline of printing processes is shown in the figure below.
MiS06002SA
ROS
[(2)Exposure]Drum Cartridge
[(1)Charge]
[(3)Development]
[(4)Transfer]
[(5)Cleaning]
FUSER UNIT
[(6)Fusing]
Transfer ASSY
[(4)Transfer]
[(7)Cleaning]:
Laser beam
: Paper transfer")
6 - 4 Chapter 6 Principles of Operation Epson AcuLaser C2900NRevision B Confidential 1.3.2 Exposure The exposure process forms an invisible electrostatic latent image on the negatively charged drum sur- face by scanning it with laser beams. This process is performed in parallel for yellow, magenta, cyan and black colors. - Laser beams are emitted from the laser diode in the ROS ASSY. The surface of each color drum is scanned from end to end in the axial direction by the rotating polygon mirror, the fixed mirror, and the lens attached to the Scanner Motor Assy of the ROS ASSY. : Laser beams (Y) : Laser beams (M) : Laser beams (C) : Laser beams (K) Wsb06004KADrum (K) Drum (C) Drum (M) Drum (Y) Polygon Mirror MirrorMirror Lens Mirror Mirror Mirror LensMirror Lens Mirror Lens Mirror Mirror Lens
6 - 5 Chapter 6 Principles of Operation Epson AcuLaser C2900NRevision B Confidential - The laser beam is irradiated according to the printing data (image data) output from the printer con- troller. The laser beam is output only when printing data is pixels (micro points composing charac- ters or pictures). (The laser diode lights up for parts to be developed by toner, and not for parts that are not to be developed.) The drum surface irradiated by the laser beam becomes a conductor, and the negative charge on the drum surface flows to the positive side and the charges cancel each other out so that the potential on the drum surface drops. The part on the surface where potential drops becomes the electrostatic latent image.
6 - 6 Chapter 6 Principles of Operation Epson AcuLaser C2900NRevision B Confidential 1.3.3 Development In the development process, toner is electrically attached to the invisible electrostatic latent image on the drum surface to form visible toner image on the drum. This process is performed in parallel for yellow, magenta, cyan and black color independently. - The toner in the toner cartridge is agitated by the built-in Agitator and fed into the developer. The Auger is driven by the toner motor.The amount of toner to be consumed according to the print count is calculated and that amount is fed into the developer. (Refer to Toner Dispense Mecha- nism.) This is called toner dispensation, which is controlled by two types of control, PCDC and ADC. (Refer to 5.3.2 Toner Density Control) - In the developer section, the incoming toner is mixed with the existing developer (toner/carrier mix- ture) by the Auger, and then supplied to the Magnet Roll located near the drum surface. The toner and carrier are charged by friction due to agitation (toner in negative, carrier in positive), and they attract each other electrically. The carrier, due to its magnetic properties, is attracted to the Magnet Roll, and then uniformly leveled by the Trimmer Rod. - The magnet roll is covered by a thin semi-conductive sleeve all over the surface. The DB (Develop- ing Bias) voltage is supplied to this semiconductor sleeve from the High Voltage Power Supply (HVPS). The DB voltage is negative DC voltage combined with AC voltage. The DC voltage keeps the magnet roll at a constant negative voltage against the photoreceptor layer of the drum. There- fore, at the area where the negative electric charge on the drum surface does not decrease, the potential is lower than that of the magnet roll, while the potential is higher than that of the magnet roll at the area where the negative charge on the drum surface decreases. The AC voltage shakes the developer on the surface of the magnet roll so that the toner easily flies to the drum. Thus, only the portions of the drum surface where the negative charge has decreased below that of the mag- net roll (electrostatic latent image) attract the toner to form an image on the drum. Once the toner is deposited on the drum, the potential and the toner-attracting force of the corresponding portion decreases because the increase of negative charge lowers the potential at that portion.
6 - 7 Chapter 6 Principles of Operation Epson AcuLaser C2900NRevision B Confidential HVPSDrum Wsb06005KA : Negative electric charge : Positive electric charge : Toner : Carrier Trimmer Rod Paddle Toner Cartridge Auger Auger Magnet Roll Agitator engine principle0013FAengine principle0014FA
6 - 8 Chapter 6 Principles of Operation Epson AcuLaser C2900NRevision B Confidential - Toner Dispense Mechanism The toner in the toner cartridge goes through the following steps before reaching the developer. Once the toner cartridge is set and the lever is moved toward the lock position, the JOINT ASSY DISP and the toner cartridge shutter move frontward, opening the toner supply port. The toner supplied from the toner cartridge is carried toward the developer by the Auger in the HOUSING ASSY AUGER. The Auger is a spiral-shaped part that carries toner forward as it rotates driven by the Dispense Motor in the FRAME ASSY MOT. After being carried to the front side of the HOUSING ASSY AUGER, the toner is fed to the devel- oper via the port of the HOUSING ASSY AUGER. MiS06003SA 1)-1 2)3) 1)-2 Toner Cartridge Auger Shutter Dispense Motor : Indicates the engagement of gears.
6 - 9 Chapter 6 Principles of Operation Epson AcuLaser C2900NRevision B Confidential 1.3.4 Transfer (Drum to Paper) In the transfer process, toner image formed on the drum surface is transferred onto the surface of the paper. The toner is transferred onto the paper in the order of Y, M, C, and K. -BTR The BTR (Bias Transfer Roll) is a conductive roll, to which the positive voltage is applied from the High Voltage Power Supply (HVPS). The BTR contacts the rear side of the Belt and applies the positive voltage to the Belt. -Belt The Belt is a conductive belt, to which the positive voltage is applied from the BTR. After the nega- tively charged toner image on the drum surface is drawn by the positive charge on the belt, it is transferred from the drum to the paper. The Belt feeds the paper to the direction of Fuser Unit. : Negative electric charge : Positive electric charge Rio06114KA Drum (K) Drum (C)BTR Drum (M) Drum (Y) Drum surface HVPS BTR BTR BTR Paper Transfer Belt: Toner
6 - 10 Chapter 6 Principles of Operation Epson AcuLaser C2900NRevision B Confidential Kmy06007KA
6 - 11 Chapter 6 Principles of Operation Epson AcuLaser C2900NRevision B Confidential 1.3.5 Cleaning (DRUM) In the Cleaning process, excess toner and charge is removed from the drum and BCR surfaces. - Drum cleaning The excess toner that was not transferred to the Transfer Belt remains on the drum surface. To prevent troubles in the subsequent processes, the excess toner is scraped off by the Cleaning Blade in contact with the drum, and then collected into the collection box as described in 1.3.8 Waste Toner Collection. - BCR cleaning The excess toner remaining on the BCR is wiped off by the Cleaning Roll made of spongy material, and then collected into the collection box as described in 1.3.8 Waste Toner Collection. - Charge cleaning When the drum is charged by BCR, any excess charge hinders the drum surface from being uni- formly charged, which may lead to print quality problems. The excess charge on the surface of the drum is eliminated by irradiating the light of the Erase Lamp (LED ASSEMBLY). Wsb06008KA
6 - 12 Chapter 6 Principles of Operation Epson AcuLaser C2900NRevision B Confidential 1.3.6 Fusing In the fusing process, toner is fixed on the paper by heat and pressure. - The toner particles are melted by the Heat Roll heated by the Heater lamp, and fused onto the print medium by the pressure between the Heat Roll and the Belt. - The Belt friction-driven by the Heat Roll nips the print media against the Heat Roll using the pres- surizing mechanism it contains. Rio06009KA PaperSpring Nip Felt Belt Nip Head Frame Belt Sheet Not fixed toner Heater Lamp Heat Roll Fixed toner
6 - 13 Chapter 6 Principles of Operation Epson AcuLaser C2900NRevision B Confidential 1.3.7 Cleaning (Transfer ASSY) In the Cleaning (Transfer ASSY) process, the transfer belt is cleaned by removing the excess toner on its surface (for the density measurement of ADC toner patch). - Collecting excess toner from the transfer belt (1) Toner on the BELT is scraped off by the Cleaner Blade that is in contact with the Drum. (2) The removed toner is dropped into the Cleaner BOX. Belt Transfer ASSY Cleaner BOX Blade Assy MiS06004SA