Panasonic DX-600 Service Manual

Also see for DX-600: Network fax guide Technical guide

Contents

204DX-600/800APR 2002Edition 1.06.1.4. Printing Process OperationChargeIn the dark, the Bias Charge Roller (BCR) applies a high, uniform negative charge to the surface of theOPC Drum. The surface potential is approximately -650 VDC and remains because the drum has a highelectric resistance in the dark.ExposureA portion of the laser beam is deflected to the timing sensor [Beam Detection (BD) Sensor], whichcontrols the start timing of scanning on the OPC Drum. The CPU also uses the timing sensor to detectabnormal signals. The light beam from the laser diode is modulated by the digital signal (nVIDEO) andconverted to parallel light waves by the collimator lens. The beam is then directed to the rotating tetragonmirror, where it is reflected to the f-θ lens and then focused onto the OPC Drum surface. The laser beammoves across the surface of the OPC Drum in the scanning direction. Where the laser beam is applied,the negative charge on the drum dissipates, and where the laser is not applied, the negative chargeremains. This action forms a latent, electrostatic image on the OPC Drum, corresponding to the originalimage.DevelopmentThis development process uses a conventional method, where toner coats a Development Roller andtransfers to the latent image on the OPC Drum. In the Toner Cartridge, the (mono-component) toner isnegatively charged by the friction between the rotating Development Roller (Mag Roller) and theDeveloping Blade. This combination and the rotation of the Mixing Blade transfers the toner from thereservoir and forms a brush effect on the Mag roller. Where the magnetic brush lightly touches the OPCDrum, the negatively charged toner is attracted to the latent image on the drum, forming a mirror imageof the original on the drum. Any remaining toner is removed from the Mag Roller by the DevelopingBlade and is recycled back into the toner reservoir. A bias voltage of approximately 1.65 kVACp-p at1.875 kHz, riding on a -300 VDC bias is applied to the magnetic brush to achieve maximum print quality.The Toner Sensor (513), a magnetic sensor, detects the remaining quantity of toner in the TonerCartridge. When the “TONER” lamp starts to blink, there is still enough toner left in the cartridge to print100 pages (based on ITU-T Image No.1). When the toner runs out, the display will show: “OUT OFHandleBias Transfer RollerLaser BeamTonerToner Waste BoxWaste TonerCleaning BladeDeveloping BladeAgitator SweeperMixing BladeOPC DrumDevelopment RollerHopper