HP 5100 Service Manual - Page 84

Image-formation system The image-formation system is the main part of the printer, and consists of six stages: 1. Cleaning 2. Conditioning 3. Writing 4. Developing 5. Transferring 6. Fusing When the formatter board sends the print signal to the dc controller board, it drives the main motor to rotate the photosensitive drum, the developing cylinder, the primary charging roller, and the transfer charging roller. The primary charging roller places a uniform negative charge on the surface of the photosensitive drum. The laser beam modulated by the video signal is illuminated on the photosensitive drum surface to form the latent image on the drum with the laser diode. The latent image formed on the photosensitive drum is changed to a visual image by the toner on the developing cylinder, then transferred to the paper by the transfer charging roller. The residual toner on the photosensitive drum surface is scraped down with the cleaning blade. The potential on the drum is uniformed by the primary charging roller to prepare for a new latent image. After the image has been transferred to the paper, it is fused onto the paper by heat and pressure at the fuser. The cartridge has a toner sensor that detects the level of remaining toner and the presence of the cartridge. If the toner in the cartridge is lower than the specified level or if no cartridge is in the printer, that information is reported to the formatter. Figure 14. Image-formation system 82 Functional information Q1860-90918