Oki OL1200 Service Manual page 27

Page: 12
Service Guide OL1200
Chapter 2 Operation Description
2.4 Electro-photographic Process
2.4.1 Electro-photographic process mechanism
This mechanism prints image data from the control board on the paper by electro-photographic process.
The Figure 2-4 shows the layout of the electro-photographic process mechanism.
(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 an 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) Registration 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 registration roller.
(4) Drum motor
This drum motor is a pulse motor of 48 steps/rotation that is two-phase excited by the signal from the
control board and is the main motor of this mechanism.
(5) LED head
Image data for each dot line from the control board is received by the shift register and latch register. The
5120 LED's are driven to radiate the image data to the image drum.
(6) 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