Sharp FO IS125N Service Manual - Page 103

2.2.2 Signal assignment to the Printer CPU pins Control unit LSU High voltage Sensor Fusing Main motor Solenoid Fan Power supply Mechanism control CPU Signal I/O Pin No. PMCLK O FlexIO0B[0] LDEN O FlexIO2A[4] S_nH O FlexIO2A[5] PDATA O FlexIO2B[0] HSYNC I FlexIO2B[4] PMD O GPIO[03] PMREADY I GPIO[24] MCON O GPIO[05] TC/BSON O GPIO[06] PWM O FlexIO0B[1] nPIN I GPIO[19] nPOUT I GPIO[18] nDOP I GPIO[01] TCT0 I GPIO[23] TCT1 I MADC_IN[2] TCT2 I MADC_IN[1] nHLON O FlexIO0B[3] RTH I MADC_IN[0] nMEN O GPIO[04] STEP O FlexIO0B[2] PUS O GPIO[07] FAN O GPIO[00] nZC I FlexIO0A[2] 1) Main Motor control: Control the rotation of Main Motor and its mechanism Main Motor is the stepper motor and drives the whole of the mechanism of LBP. Main Motor is driven in 2-phase excitation by the driver (IC500: A3982SLB). The driver circuit is provided with the fuse (F500) to shut the motor power supply for the safety. 2) Pickup Solenoid drive: Drive a solenoid for paper pickup Pickup Solenoid drives the pickup mechanism of print paper. The driver circuit is provided with the fuse (F501) to shut power supply for the safety. Fax Engine controls the timing to pickup the paper with watching the paper sensor. 3) Fuser control: Control the temperature of the fuser unit The heater lamp is controlled ON/OFF to adjust the temperature of the fusing unit. The heater lamp is driven by the driver (Q900). The temperature of the fusing unit is monitored with the thermistor. The fuser control circuit is provided with the safety circuit to stop to light the heater lamp automatically when the thermistor detection temperature rises over unusual high temperature. 4) High Voltage Generator control: Control high voltage supplied to LBP • Main charger voltage to the drum unit • Developing bias voltage to the toner unit • Transfer charger voltage to the transfer roller The high voltage outputted from High Voltage unit is controlled with PWM and ON/OFF signals ("MCON" and "TCON"). 5) Laser Scanning control: Control Optical unit (LSU) to expose the OPC drum. The laser beam scanning light expose the OPC drum corresponding to the print data. The circuit of Optical unit (LSU) is composed with the scanning motor drive block and the laser beam drive block. a) The control of the scanning motor drive block The scanning motor is controlled by the clock of 2659Hz ("PMCLK") and ON/OFF signal ("PMD"). Optical unit (LSU) replies by the ready when the rotation of the motor becomes stable. The initialization of the laser beam control is started after the stable rotation of the scanning motor is confirmed. FO-IS125N Description Polygon motor clock Laser circuit driving signal APC circuit sample signal Laser on signal Laser main scanning syncronism signal Polygon motor driving signal Polygon motor turn syncronism detection Charge control Transfer/DC bias control Clock for high voltage control clock PWM Main unit paper feed detection (Paper-In) Paper eject detection (Paper-Out/fusing section) Door open/close detection (front and right doors) Toner cartridge identification Heater lamp ON/OFF control Thermistor analog input (temperature detection) Excitation enable Step clock Solenoid ON/OFF control Fan ON/OFF control AC zero-cross signal input b) The laser beam drive block The timing of the signals is controlled in accordance with the specifications of Optical unit (LSU). Fax Engine (IC100) outputs the print data ("PDATA") synchronized in the horizontal synchronous signal ("SYNC") from Optical unit (LSU). 6) Sensor monitor: Monitor each sensor Fax Engine controls the timing of the printing action with the following sensor information, and detect the paper jam, the paper empty and the paper size. a) P-IN: Detect carriage position of the paper b) P-OUT: Detect carriage position of the paper c) TCT2~0: Detect the toner cartridge setting 5 - 12