Canon MF4100 Series Service Manual

Contents

Chapter 66-2Put the toner on the electrostatic latent image on the surface of the photosensitive drum to visualizeStep 3: Development3) Transfer blockThe toner image on the surface of the photosensitive drum is transferred to papers.Step 4: Transfer (Transfers the toner on the photosensitive drum to a paper)Step 5: Separation (Separates the paper from the photosensitive drum)4) Fixing blockThe toner image is fixed on the paper.Step 6: Fixing5) Drum cleaning blockThe residual toner on the photosensitive drum is removed.Step 7: Drum cleaning (Removes the residual toner on the photosensitive drum)6.2 Driving and Controlling the High-Voltage System6.2.1 Generation of Transfer Charging Bias 0014-5403i-SENSYS MF4150 / i-SENSYS MF4140 / i-SENSYS MF4120 /The transfer charging bias (TRS) is output to transfer the toner on the photosensitive drum to papers.There are transfer charging DC positive bias and transfer charging DC negative bias generated at the transfer charging bias generation circuit in the high-voltagepower supply circuit. The transfer charging DC positive bias is output to the transfer charging roller at transferring the toner. The transfer charging DC negativebias is applied to the transfer charging roller at cleaning the transfer charging roller.The transfer charging bias generation circuit applies these transfer charging biases to the transfer charging roller according to each print sequence.The following are the biases for print sequences.- Cleaning bias:This is the bias for transferring the toner on the photosensitive drum to the paper at the time of print sequence. The transfer charging DC positive bias is applied tothe transfer charging roller.- Sheet-to-sheet bias:This is the bias to prevent the residual toner on the photosensitive drum from being attracted to the transfer charging roller, at between sheets during continuousprinting. Faint transfer charging DC positive bias is applied to the transfer charging roller.- Cleaning bias:This is the bias to return the residual toner on the transfer charging roller to the photosensitive drum at the time of warm-up or last rotation sequence. The transfercharging DC negative bias is applied to the transfer charging roller.The transfer charging DC positive bias is changed due to the instruction of the DCNT board. To realize appropriate transfer density, the DCNT board changes thevoltage of the transfer charging DC positive bias for constant current control according to the transfer current feedback signal (TRCRNT) sent from the transfercharging bias generation circuit.