HP Color 9850mfp Service Manual - Page 105

II UNIT EXPLANATION hp Color 9850mfp Symbol Name [9] Toner guide brush [10] Toner collection screw [11] Image correction unit [12] Transfer belt separation claw [13] 2nd transfer roller U [14] 2nd transfer roller L (Provided on ADU side) M18 Transfer belt motor M19 SD1 PS15 1st transfer pressure/release motor Transfer belt separation claw solenoid 1st transfer HP sensor PS68 Encoder sensor/belt 1 PS69 Encoder sensor/belt 2 TRANSFER BELT UNIT Function or method Scraping and collection of toner on the transfer belt Conveys toner from the belt cleaning section to the toner collection section Screw method Detection of variety of information of images transferred on the transfer belt Paper separation assist from the transfer belt Pressure/release method by the transfer belt separation claw solenoid (SD1) Toner transfer from the transfer belt to paper Constant current DC bias applied roller method DC output range by constant current method: +30 to -120µA Toner transfer from the transfer belt to paper Pressure/release mechanism by means of cam Driven idly by the transfer belt Driving of the transfer belt DC brushless motor, PLL control Pressure/release of the 1st transfer roller Y, M, C, K Stepping motor Pressure/release of the separation claw 24VDC drive Pressure/release mechanism of the 1st transfer roller Y, M, C, K Home position detection Detection of the rotation of encoder for the transfer belt drive shaft Drive control of the transfer belt motor (M18) 2 sensors of the PS68 and PS69 are provided at the opposite position of the encoder to cancel the change of rotation caused by the eccentricity of the encoder. Detection of the rotation of encoder for the transfer belt drive shaft Drive control of the transfer belt motor (M18) 2 sensors of the PS68 and PS69 are provided at the opposite position of the encoder to cancel the change of rotation caused by the eccentricity of the encoder. 2-31