HP LaserJet P4510 Service Manual - Page 131

Step 2: Laser-beam exposure The laser beam scans the photosensitive drum to neutralize the negative charge on portions of the drum surface. An electrostatic latent image forms where the negative charge was neutralized. Figure 5-16 Laser-beam exposure Laser beam Unexposed area Exposed area Block 2: Developing Toner adheres to the electrostatic latent image on the photosensitive drum. Step 3: Developing Toner acquires a negative charge from the friction that occurs when the developing cylinder rotates against the developing blade. The negatively charged toner is attracted to the latent image on the photosensitive drum surface because the drum surface has a higher potential. The AC bias that is superimposed with the developing negative DC bias is applied to the developing cylinder. Figure 5-17 Developing Blade Developing cylinder Exposed area Unexposed area Photosensitive drum Unexposed area Exposed area AC bias DC bias Block 3: Transfer During the steps that comprise this block, a toner image on the photosensitive drum is transferred to the print media. ENWW Image-formation system 117