Canon LBP-800, Руководство по обслуживанию

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2. Operation
When the power is switched ON, the printer enters the WAIT mode.
When the printer is ready for operation after the WAIT period, the engine controller sends the
ready status to the interface controller to notify that the printer is ready.
On receiving the ready status, the interface controller sends the pick-up command to the
engine controller.
When the engine controller receives the pick-up command, it starts the operation of the ini-
tial rotations (INTR) sequence.
When the paper is picked up and the engine controller detects that the paper has reached the
specified position, it starts sending the /BD signal to the interface controller.
When the interface controller receives the /BD signal sent from the engine controller, it sends
the VIDEO signals (/VDO, VDO) synchronized with the /BD signal to the laser driver via the
engine controller.
The engine controller generates LASER CONTROL signals (CNT0, CNT1) and sends them to
the laser driver.
The laser diode emits the laser beam when the /VDO signal is “L”, CNT0 signal is “H”, and
CNT1 signal is “L.” The laser beam emitted from the laser diode is scanned by the scanning mir-
ror to form a latent image on the photosensitive drum.
The latent image on the photosensitive drum is transferred onto the plain paper through the
electrophotographic process and then delivered to the face up delivery slot.
The STATUS COMMAND signal (/SC) is a bi-directional signal for serial data exchange
between the interface controller and engine controller.
The interface controller uses the /SC signal to send the 16 bit serial data as a command to
the engine controller. On receiving the command from the interface controller, the engine con-
troller uses the/SC signal to send back the 16 bit serial data as a status.
The command and status sent from the interface controller and the engine controller respec-
tively are synchronized with the SYNCHRONIZE CLOCK signal (/SCLK) output from the inter-
face controller. When the interface controller initiates the communication with the engine con-
troller, the interface controller outputs the data to the /SC signal synchronizing it with the
falling edge of the /SCLK signal, and the engine controller inputs the data to the /SC signal syn-
chronizing it with the rising edge of the /SCLK signal. When the engine controller initiates the
communication with the interface controller, the engine controller outputs the data to the /SC
signal synchronizing it with the falling edge of the /SCLK signal, and the interface controller
inputs the data to the /SC signal synchronizing it with the rising edge of the /SCLK signal.
The interface controller can perform the software reset on the engine controller by keeping
the /SCLK signal “L” for 2 seconds. The /RESET signal is used to initialize the interface con-
troller at the power-ON. The signal is sent to the interface controller from the engine controller.
3. Cleaning page
This printer can execute the cleaning page sequence with the command sent from the inter-
face controller. The cleaning page cleans the pressure roller.
On receiving the cleaning page execution command from the interface controller, the engine
controller conducts the paper pick-up operation. Then, the engine controller adjusts the fixing
temperature at 200°C and feeds the paper 4mm at a time by step driving the main motor. This
cleans the pressure roller by fusing the toner adhered to the pressure roller onto the paper.
Note: The paper used for cleaning the pressure roller must be the maximum size used by the
user in horizontal direction and 240mm or more in the vertical direction (feed direction).
CHAPTER 2
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