Paper Feed Operation - Sharp MX-LCX3N Service Manual

C. Lowering operation by paper supply
If the tray is pulled out when it is at the paper supply position, the
tray lock solenoid keeps the lock open.
When the tray is pulled out, the tray LED turns OFF.
When the paper front surface sensor (LPUD) is turned ON for 2sec
while the tray is pulled out, the lift motor is turned ON to lower the
tray.
When the paper front surface sensor (LPUD) is turned OFF while
the tray is lowered, the lift motor is turned OFF to stop the tray.
When the lower limit sensor (LDD) is turned ON while the tray is
lowered, the lift motor is turned OFF to stop the tray regardless of
the state of the paper front surface sensor (LPUD).

2. Paper feed operation

When the tray is stationary at the paper feed position (upper limit
sensor: LUD ON position) and there is paper on the tray, paper
feed operation can be performed.
Paper feed operation is performed by the transport motor (LPFM),
the transport clutch (LTRC), the paper feed clutch (LPFC), and the
paper feed solenoid (LPFS) at the following timing.
Paper feed time chart
Paper feed start
LPFM
Clearance-between-
(Transport motor)
papers control timer
LTD
(Transport sensor) PIC drop timer
LPFS
(Paper feed solenoid)
Paper feed clutch
LPFC
(Paper feed clutch)
LTRC
(Transport clutch)
TRC-LCC
(Main unit
synchronous signal)
Preliminary
paper feed start
First sheet
Preliminary paper
feed complete
Paper feed start
Clearance-between-
papers control timer
PIC drop timer
Paper feed clutch
OFF timer OFF timer
Resist stop
Preliminary Preliminary
paper feed start paper feed start
Second sheet Third sheet
Preliminary paper
feed complete
Paper feed start
MX-LCX3N OPERATIONAL DESCRIPTION 5 – 2
Lowering operation (when paper is supplied or when the paper
front surface sensor is turned ON)
LLM
(Lift motor output)
LDD
(Lower limit sensor)
LPUD
(Paper front surface
sensor) 2 [sec]
LRE
(Encoder signal)
Lowering operation (when paper is supplied or when the lower
limit sensor is turned ON)
LLM
(Lift motor output)
LDD
(Lower limit sensor)
LPUD
(Paper front surface
2 [sec]
sensor)
LRE
(Encoder signal)
When the transport clutch (LTRC) is turned ON with the transport
motor (LPFM) ON (rotating), the transport roller rotates. When the
paper feed clutch (LPFC) is turned on under this state, the paper
feed roller and the take-up roller rotate. When the paper feed sole-
noid (LPFS) is turned ON, the take-up roller is pushed down to
press paper.
Clearance-between- Clearance-between-
papers control timer papers control timer
PIC drop timer PIC drop timer
Paper feed clutch Paper feed clutch
OFF timer
Resist stop
Preliminary
paper feed start
Fourth sheet
Preliminary paper Preliminary paper
feed complete feed complete
Paper feed start Paper feed start
Paper feed clutch
OFF timer OFF timer
Resist stop Resist stop
Preliminary
paper feed start
Fifth sheet
Preliminary paper
feed complete
Paper feed start