HP 2100 Service Manual - Page 92

Cleaning Stage Figure 5-9 Cleaning the Photosensitive Drum At the cleaning stage, the photosensitive drum's surface is prepared to hold an image. During printing, the drum rotates completely several times per printed page. Before forming the image for a given section of print, a cleaning blade removes toner from the previous rotation of the drum. The toner cartridge stores waste toner and prevents it from being used in later print jobs (see figure 5-9). Conditioning Stage Figure 5-10 Primary Charging Roller At the Conditioning Stage, the primary charging roller applies a uniform negative charge on the photosensitive drum's surface. Conductive rubber coats the primary charging roller with an AC bias to erase any residual charges and maintain a constant potential on the drum's surface. In addition, the primary charging roller applies a negative DC bias to create a uniform negative potential on the drum's surface. 82 5 Functional Overview C4170-90959