Xerox 8500DN Service Manual - Page 59

Transfixing and Exiting Theory of Operation Transfixing and exiting consists of four major functions: 1. Staging the paper for rendezvous with the image on the drum and transfix roller nip. 2. Loading the transfix roller and engaging the drum stripper blade assembly. 3. Stripping the paper from the drum. 4. Exiting the paper from the printer, or exiting the paper for (2-sided) duplex printing. Tripping the preheat exit sensor (see previous illustration) sets up a series of events, which take place on a predetermined schedule. Paper is transported through the Preheater to thermally prepare it for transfixing. The preheat sensor detects the paper's presence, and accurately references the leading edge of the media with the image on the Drum. Based on the timing information from the Preheater, the leading edge of the media is advanced to the transfix nip. Once the media is stopped in the transfix nip, the Process Drive gears move to rotate the Transfix Camshaft to bring the Transfix Roller into contact with the Drum. The Transfix Roller nip applies the load necessary to transfer the image to the media from the Drum. At the point where the Transfix Roller loads, but before the Drum begins to rotate, the Stripper Solenoid engages. The Stripper Solenoid positions the stripper blade. The solenoid mounts on the Upper Inner Duplex guide and activates the strip solenoid lever, which in turn rotates the Stripper Carriage until it hits the transfix ground pins. This action causes the stripper blade to drop onto the deadband of the Drum. After the Transfix Roller and the stripper engage, the Drum rotates to advance the media and transfix the image. The stripper blade catches the leading edge of the sheet of media and separates it from the Drum. After the leading edge is beyond the stripper blade, the Stripper Solenoid de-energizes. When the solenoid is de-energized, the solenoid return spring provides a force to move the solenoid plunger out of the solenoid coil which rotates the Stripper Carriage back to its ready position. Once the entire image is transferred, the Drum stops rotating and the Process Drive lifts the Transfix Roller. The Media Drive now rotates the Exit Rollers in the correct direction to pull the media out. However, the Deskew Clutch is de energized so the deskew rollers are not driven during transfix. The Exit Rollers deposit the media into the Output Tray, ending the print cycle. Phaser 8400/8500/8550/8560 Color Printer Service Manual 2-27