6 - 30Chapter 6 Principle of Operation6.2 ROS Control6.2.1 Rotation of Scanner MotorThe control (ON/OFF) of the rotation of the Scanner Motor is performed as shown below according tothe mode of operation.The following table gives the resolution that differs according to the specifications of the machine, andthe corresponding rotational speeds of the Scanner Motor.dpi (dot per inch)rpm (revolutions per minute)Reference Each facet of the Polygon Mirror (12 facets for 34PPM, and 6 facets for 24PPM) isscanned with a laser beam.6.2.2 Warm-up of ROSThe Scanner Motor rotates simultaneously with the warm-up of the ROS. The SOS signal is sampledat intervals of 100 ms. If the obtained value is shorter than the Ready reference value threeconsecutive times, the warm-up of the ROS is ended (The Scanner Motor is rotating at a constantspeed).6.2.3 ROS Reference ValueReference If the speed of the Scanner Motor increases by more than 1%, the laser beam doesnot enter the SOS Sensor, and "U2" is detected in terms of Fail reference value.Mode of operation ON/OFF of rotation of Scanner MotorStandby state Kept OFF.Printing stateTurned on by receiving signal from the Control-ler, and turned off after 10 s since end of print-ing.Power-saving state Kept OFF.Type Process Speed Resolution RPM of Scanner CLK signal frequency34PPM 204mm/s 600dpi 24,094.49rpm 2,049.449Hz1200dpi 24,094.49rpm 2,049.449Hz24PPM 141mm/s 600dpi 33,307.09rpm 3,300.708Hz1200dpi 33,307.09rpm 3,300.708HzROS reference value DescrptionReady reference value SOS signal interval corresponding to less than 98% of the specifiedrotational speed of the Scanner MotorFail reference value SOS signal interval corresponding to less than 90% of the specifiedrotational speed of the Scanner Motor
