Chapter 22-95) ITB cleaning blockCleans residual toner on the photosensitive drum and ITB.Step 9: Auxiliary ITB cleaning roller charging - Residual toner on the ITB is charged in order to be held on the ITB.Step 10: ITB cleaning roller charging - Residual toner on the ITB is charged.Step 11: ITB cleaning - Residual toner on the ITB is transferred onto the drum.Step 12: Drum cleaning - Residual toner adhered to the drum is cleaned.2.3.1.3 Electrostatic Latent Image Formation Block 0007-4978This block comprises three steps, which forms an electrostatic latent image on the photosensitive drum.After the completion of the last step in this block, negative charges remain in areas on the drum surface exposed to laser beams. Negative charges are removed fromareas exposed to the laser beams.An image with negative charges on the drum is called an "electrostatic latent image" since it is invisible to the eye.F-2-14Step 1: Primary chargingA uniform negative potential is applied to the drum surface in preparation for latent image formation, in this step.The primary charging roller is made with conductive rubber. A DC bias is applied to the primary charging roller to keep the potential on the drum surface uniformly.F-2-15Step 2: Laser beam exposureAn electrostatic latent image is formed on the photosensitive drum in this step.When the laser beams scan a negatively charged drum surface, it causes the charges in areas struck by the laser beams to be neutralized. An electrostatic latentimage is formed in areas on the drum where the negative charges are eliminated.F-2-162.3.1.4 Developing Block 0007-4979This block is comprised of two steps (see Step 3 and Step 4). In this block, the image becomes visible by utilizing a developing method called contact developmentmethod, where the toner is transferred onto the electrostatic latent image on the drum surface. In this method, developing cylinder adheres closely to the photosen-sitive drum to push up the toner.Toner (development agent) used in this printer is non-magnetic single-component toner, composed of resins, etc.Time (t)Surface potential (V)ExposedareasUnexposedareasLaser beamexposure(step 2)Primarytransfer(step 5)Primarycharging(step 1)0-100-500Primarycharging(step 1)PhotosensitivedrumPrimary charging rollerAC biasDC biasLaser beamUnexposedareasExposedareas
