Chapter 22-402) When the pulse count for ENCODER DETECTION signal does not fit in the prescribed range, (within -/+ 200 of a targeted pulse count memorized by CPU)after a period of time from the start of the drive when the developing rotary motor becomes Ready.The encoder used in this printer consists of a disk, reflective sensor, and detection unit. The disk is installed on the motor shaft. The disk rotates as the motor does.The disk has reflective areas and interrupting areas alternately located on its surface. The sensor strikes light to the rotating disk and sends the monitoring resultsof the reflected light to the detection unit. The detection unit monitors the results constantly. It generates the two ENCODER DETECTION (ENCSNS1, ENCSNS2)signals based on the tim-ing of detecting the reflective and interrupting areas on the disk and sends the signals to the DC controller.F-2-552.6.2.6 Cooling Fan 0008-1730The Cooling fan, a DC brushless motor with a built-in Hall device, cools off around the fixing unit, power supply unit, high-voltage power supply PCB, and car-tridge.The CPU (IC101) controls the cooling fan.The CPU outputs the FAN DRIVE (FAN1D) signal after receiving a print command from the interface controller and rotates the cooling fan. After the completionof a print operation, the CPU rotates the fan for a specified period based on internal temperature by monitoring the internal temperature detection thermistor (TH3).Then it stops the fan.(Refer to the table below)The CPU monitors the FAN LOCK DETECTION (/FAN1S) signal while the cooling fan is rotating. If the signal remains "H" continuously for more than 10 sec-onds, the CPU determines a fan failure, then stops the printer engine, and notifies the failure to the interface controller.F-2-56T-2-9Thermistor detection temparature (deg C) Fan rotation time (s)44 or less 045 to 49 3050 or more 300ENCSNS1ENCSNS2ROTHPS Start of ENCODER DETECTIONsignal monitoring(Normal speed)ENCSNS2(Slow)ENCSNS2(Fast)DelayedHastenedENCSNS1 DelayedENCSNS1THastenedTDiskReflectingareasInterruptingareasMotorshaftReflectivesensor Sensor outputENCSNS1ENCSNS2DetectionunitIC101CPUFAN1D/FAN1S FM721J123-1-3+24VBDCNT boardSLVTHJ137-1 TH3Internal temperaturedetection thermistorFan motorcontrol circuitCooling fan
