Xerox 4400DT Service Manual - Page 416

Print Process Overview There are seven steps in the Phaser 4400 print process. This seven step cycle is repeated for each sheet of paper that is sent through the printer. The seven steps in the print process are: 1. Charge - A Bias Charge Roller (BCR) places a uniform negative electric charge on the drum surface. 2. Exposure - The laser scanner scans the drum surface with a very thin beam of laser light modulated according to the signal from the Engine Logic Board to form an invisible electrostatic latent image on the drum surface. 3. Development - Attracts toner to the electrostatic latent image on the drum surface to form a visible toner image. 4. Transfer - Transfers the toner image from the drum surface to the paper. 5. Discharge - Partially neutralizes the charge on the paper to allow the paper to peel off the drum surface. 6. Fusing - Permanently fixes the toner image to the paper by heat and pressure. 7. Cleaning - Cleans the drum surface of the remaining toner. The block diagram of the Phaser 4400 print cycle shows the sequence of events for the xerographic process and the paper flow into and out of the printer. Block Diagram of the Print Cycle Phaser 4400 Laser Printer Service Manual 8-3