Ros Control; Rotation Of Scanner Motor; Warm-Up Of Ros; Ros Reference Value - Oki B6500 Service Manual

6.2 ROS Control

6.2.1 Rotation of Scanner Motor

The control (ON/OFF) of the rotation of the Scanner Motor is performed as shown below according
to the mode of operation.
Mode of operation
Standby state
Printing state
Power-saving state
The following table gives the resolution that differs according to the specifications of the machine,
and the corresponding rotational speeds of the Scanner Motor.
dpi (dot per inch)
rpm (revolutions per minute)
Each facet of the Polygon Mirror (12 facets) is scanned with a laser beam.

6.2.2 Warm-up of ROS

The Scanner Motor rotates simultaneously with the warm-up of the ROS. The SOS signal is
sampled at intervals of 100 ms. If the obtained value is shorter than the Ready reference value three
consecutive times, the warm-up of the ROS is ended (The Scanner Motor is rotating at a constant
speed).

6.2.3 ROS Reference Value

ROS reference value
Ready reference value
Fail reference value
If the speed of the Scanner Motor increases by more than 1%, the laser beam does
not enter the SOS Sensor, and "U2" is detected in terms of Fail reference value.
ON/OFF of rotation of Scanner Motor
Kept OFF.
Turned on by receiving signal from the Controller, and turned off after 10 s
since end of printing.
Kept OFF.
Process Resolu-
Speed tion
600dpi
269mm/s
1200dpi
SOS signal interval corresponding to less than 98% of the
specified rotational speed of the Scanner Motor
SOS signal interval corresponding to less than 90% of the
specified rotational speed of the Scanner Motor
6 – 30
Chapter 6 Principles of Operation
RPM of CLK signal fre-
Scanner quency
31,772rpm 3,177.2Hz
31,772rpm 3,177.2Hz
Description