Canon MF4690 - ImageCLASS B/W Laser Service Manual

Also see for ImageCLASS MF4690: Reference guide Instructions Starter Guide Operation guide Driver guide

Contents

Chapter 66-16.1 Overview/Configuration6.1.1 Configuration 0016-1839The image forming system is the core part of this machine, and is composed of the cartridge, the transfer charging roller, the fixing assembly, etc.When receiving the print command from the SCNT board, the DCNT board activates the main motor to rotate the photosensitive drum, the developing cylinder,the primary charging roller, the transfer charging roller and the pressure roller.The surface of the photosensitive drum is evenly charged negative by the primary charging roller, and the laser beam converted with the video signal (VDO, /VDO)is reflected to the surface of the photosensitive drum to form the latent image by the laser diode.The latent image formed on the photosensitive drum is turned visible with the toner on the developing cylinder and is transferred on the paper by the transfer charg-ing roller. The transferred toner turns into the permanent image on the paper when the heat and pressure are applied there at the fixing assembly. The cleaner bladeremoves the residual toner on the surface of the photosensitive drum, whose potential is made even by the primary charging roller to be ready for the formation ofthe next latent image.F-6-16.1.2 Print Process 0016-1840The print process shows the basic operation process for image formation by the printer.The print process of this machine has the main 5 blocks and 7 steps. The toner image is formed on papers by following the steps of each block.The following is the outline of the blocks and steps of the print process.F-6-21) Electrostatic latent image formation blockElectrostatic images are formed on the photosensitive drum.Step1: Primary charging (Charges negative potential evenly on the surface of the photosensitive drum)Step 2: Laser beam exposure (Forms electrostatic images on the photosensitive drum)2) Developing blockPut the toner on the electrostatic latent image on the surface of the photosensitive drum to visualizeStep 3: Development3) Transfer blockLaser /scanner blockCleaner bladePhotosensitivedrumPrimary charging rollerCartridgeBladeDeveloping cylinderTransfer chargingrollerFixing film areaDCNT board Print commandVideo signal VDO /VDOPR1TRSDEV SCNT boardLaser beam6. FixingDrum cleaningblock3. DevelopmentFixing blockTransfer blockElectrostatic latentimage formation block2. Laser beam exposure1. Primary chargingDeliveryFlow of paperDirection of drum rotation5. Separation4. Transfer7. Drum cleaningPick-upDeveloping block