Oki OKIPAGE18 Maintenance Manual page 23

(1) Image drum unit
The image drum unit consists of a sensitive drum, a charger, and a developer. The unit forms
a toner image on the sensitive drum, using a electrostatic latent image formed by the LED
head.
(2) Hopping motor
This motor is a pulse motor of 48 steps/rotation that is two-phase excited by the signal from
the control board. It drives the hopping roller of the first tray and the front feed roller via two
one-way clutches according to the direction of rotation.
(3) Motor-Main
This motor is a pulse motor of 72 steps/rotation that is two-phase excited by the signal from
the control board and is the main motor of this mechanism.
(4) Clutch (for Regist)
Swithes the transfer of power to Roller Regist if necessary depending on the power from
Motor-Main and instructions from the control PCB.
(5) Clutch (for Feed Roller)
Swithes the transfer of power to Feed Roller if necessary depending on the power from Motor-
Main and instructions from the control PCB.
(6) LED head
Image data for each dot line from the control board is received by the shift register and latch
register. The 4992 LEDs are driven to radiate the image data to the image drum.
(7) Fuser
The fuser consists of a heater, a heat roller, a thermistor and a thermostat.
An AC voltage from the power supply board is applied to the heater under the control of the
HEATON signal from the control board. This AC voltage heats the heater. The control board
supervises the heat roller temperature via the thermistor, and regulates the heater roller at
a predetermined temperature (202 °C : Normal paper, MEDIA TYPE = MEDIUM) by
connecting or disconnecting the AC voltage supply to the heater.
If the heater roller temperature rises abnormally, the thermostat of the heater voltage supply
circuit is activated to cut the AC voltage supply forcibly.
40931201TH Rev. 4
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