Canon LBP1760P, Service Manual

Page: 101 / 394

VIII. ENVELOPE FEEDER
A. Outline
The operation sequences of the envelope feeder are controlled by the envelope feeder driver. A
4-bit microprocessor is used in the envelope feeder driver, which controls the sequences of the
envelope feeder and the serial communication with the engine controller of the printer.
The engine controller outputs the pick-up command to the paper feeder driver at the neces-
sary timing. The envelope feeder driver drives the solenoid in response to the command. The
envelope feeder driver also sends back the status of the envelope feeder to the engine controller.
The printer su24VDC to the envelope feeder. The envelope feeder driver generates
+3.3V for the ICs based on this +24V.
The flow of input/output signals to/from the envelope feeder driver PCB is as shown below.
Figure 2-8-1
2 - 63
CHAPTER 2
Envelope feeder driver PCB
Accepts the command when "L." /SEL2
+24VA
J901-1
-2
-3
J911-3
-2
-1
To printer
Command input
Status output
Serial clock SOUT
SIN
SCLK
J901-4
-5
-6
J912-3
-2
-1
To printer
Envelope sensor
PS901
+24VA
Envelope pick-
up solenoid
SL901
ENV SOL Starts envelope pick-up when "L."
J902-1
-2
Envelope
multiple
feed sensor
PS902
J913-3
-1
-2
+24VA
J903-1
-3
-2
MF SNS
"L" when the sensor detects multiple
envelopes.