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(3) Thermal control
1. The heater lamp, thermistor, main PWB, DC power supply PWB,

and triac within the power supply unit are used to control the
temperature in the fuser unit.
To prevent against abnormally high temperature in the fuser unit, a
thermal breaker and thermal fuse are used for safety purposes.

2. The surface temperature of the upper heat roller is set to 165˚C 

∼

190˚C. The surface temperature during the power save mode is set
to 100˚C.

3. The self-check function comes active when one of the following

malfunctions occurs, and an "H" is displayed on the multicopy win-
dow.

a. When the heat roller surface temperature rises above 240˚C.
b. When the heat roller surface temperature drops below 100˚C

during the copy cycle.

c. Open thermistor
d. Open thermal fuse
e. When the heat roller temperature does not reach 190˚C within

27 second after supplying the power.

(4) Fusing resistor
Fusing resistor
This model is provided with a fusing resistor in the fusing section to im-
prove transfer efficiency.
General descriptions are made in the following.

General descriptions
Since the upper heat roller is conductive when copy paper is highly
moistured and the distance between the transfer unit and the fusing
unit is short, the transfer current leaks through the copy paper, the
upper heat roller and the discharging brush.

Saftey device
(Thermal breaker, thermal
fuse)

Triac (in the

power supply unit)

Level of the thermistor is
controlled by the main PWB.

With th e signal from the
main PWB, the triac  is

controlled on and o ff.

(power  supply PWB )

Heated by the heater
lamp.(950W)

The surface temperature
of the upper heat roller is
sensed by the thermistor.

(1)

Scanner unit

(6)

Main charger

(11)

Pickup roller

(2)

Copy lamp

(7)

Heat roller

(12)

Manual paper feed tray

(3)

Lens unit

(8)

Pressure roller

(13)

Manual paper feed roller

(4)

LSU (Laser unit)

(9)

Drum

(14)

PS roller unit

(5)

Paper exit roller

(10)

Transfer unit

(15)

Paper feed roller

Paper feed is made in two ways; the tray paper feed and the manual paper feed. The tray is of universal-type, and has the capacity of 250 sheets.
The front loading system allow you to install or remove the tray from the front cabinet.
The general descriptions on the tray paper feed and the manual paper feed are given below.

(2)

(4)

(1)

(3)

(5)

(6)

(7)

(8)

(9)

(10)

(11)

(13)

(12)

(14)

(15)

DM-1505

6  –  4

(1) Cassette paper feed operation
1) The figure below shows the positions of the pick-up roller, the paper

feed clutch sleeve, and the paper feed latch in the initial state
without pressing the COPY button after lighting the ready lamp.
The paper feed latch is in contact with the projection of the clutch
sleeve.

2) When the COPY button is pressed, the main drive motor starts

rotating to drive each drive gear.
The pick-up drive gear also is driven at that time. Since, however,
the paper feed latch is in contact with the projection of the clutch
sleeve, rotation of the drive gear is not transmitted to the pick-up
roller, which does not rotate therefore.

3) After about 0.1 sec from when the main motor start rotating, the

tray paper feed solenoid (PFS) turns on at a moment.
This disengages the paper feed latch from the projection of the
clutch sleeve, transmitting rotation of the pick-up drive gear to the
paper feed roller shaft, rotating the pick-up roller to feed the paper.

4) After more than half rotation of the pick-up roller, the paper feed

latch is brought in contact with the projection of the clutch sleeve,
stopping rotation of the pick-up roller.

5) At this time, the paper is fed passed the paper entry detection

switch (PPD1), and detected by it. After about 0.15 sec from detec-
tion of paper by PPD1, the tray paper feed solenoid (PFS) turns on
so that the clutch sleeve projection comes into contact with the
paper feed latch to stop the pick-up roller. Then the pick-up roller
rotates for about 0.15 sec so that the lead edge of the paper is
evenly pressed on the resist roller, preventing against skew feed-
ing.

6) To release the resist roller, the tray paper feed solenoid and the

resist solenoid are turned on by the paper start signal to disengage
the resist start latch from the clutch sleeve projection, transmitting
rotation of the resist drive gear to the resist roller shaft. Thus the
paper is transported by the resist roller.

7) After the resist roller starts rotating, the paper is passed through the

pre-transfer guide to the transfer section. Images are transferred on
the paper, which is separated from the OPC drum by the drum
curve and the separation section.

8) The paper separated from the drum is passed through the fusing

paper guide, the heat roller (fusing section), POD (paper out detec-
tor) to the copy tray.

OFF

PFS

OFF

RRS

OFF

PFS

OFF

RRS

ON

PFS

OFF

RRS

OFF

PFS

ON

RRS

DM-1505

6  –  5

(2) Manual multi paper feed operation
1) Before paper feed operation, the manual paper feed solenoid

(MPFS) is turned OFF as shown in the figure below.

2) When the PRINT button is pressed, the manual paper feed

solenoid (MPFS) turns on to disengage the manual paper feed latch
A from the manual paper feed clutch sleeve A, rotating the manual
paper feed roller and the manual take-up roller. At the same time,
the manual paper feed stopper opens and the manual take-up roller
is pressed to the surface of the paper to start paper feeding.

3) When pawl C of the manual paper feed clutch sleeve is hung on the

manual feed latch, the manual feed stopper falls and the manual
take-up roller rises. At that time, the manual paper feed roller is
rotating.

4) The lead edge of the transported paper is pressed on the resist

roller by the transport roller. Then the paper is stopped temporarily
to make synchronization with the lead edge of the image on the
OPC drum.
The operations hereinafter are the same as the paper feed opera-
tions from the tray. (Refer to A-5 

∼ 8.)

5) The solenoid turns off to close the gate and return to the initial

state.

(3) Conditions of occurrence of paper misfeed
a. When the power is turned on:

PPD or POD is ON when the power is turned on.

b. Copy operation

a. PPD1 jam

1) PPD1 does not turn off within 4 sec

after turning on the resist roller.

b. PPD2 jam

1) PPD2 is off immediately after turning on

the resist roller.

2) PPD2 does not turn off within 1.2 sec

after turning off the resist roller.

OF

MPFS

F

C

A

ON

MPFS

A

C

ON

MPFS

A

C

OF

MPFS

F

A

C

DM-1505

6  –  6

c. POD jam

1) POD does not turn on within 2.9 sec

after turning on the resist roller.

2) POD does not turn off within 1.5 sec 

∼

2.7 sec after turning off PPD2.

1) When the power is turned on, the detection gear 38T is rotated in

the arrow direction by the detection gear 20T to push the micros-
witch (process detection switch) installed to the machine sensor
cover, making a judgement as a new drum.

2) When the detection gear 38T turns one rotation, there is no gear

any more and it stops.
The latch section of the 38T gear is latched and fixed with the
projection of the process cover.

Set duplex documents on the document tray.
Set paper on the cassette. (In the duplex mode, the manual feed tray
cannot be selected.)

Document transport: The document feed roller feeds the document

from the paper feed roller to the PS roller.
→ The document is exposed in the exposure

section, and sent to the document exit section
by the transport/paper exit roller.

→ R-SPF gate solenoid ON

→ The document is sent to the intermediate tray

(but not discharged completely.)

→ The document is stopped once, then

switchback operation is performed. (To the
back copy)

Paper transport:

The document is passed through the paper feed
roller and the PS roller by the paper feed roller
and the images on the front surface are trans-
ferred.
→ The paper is passed through the fusing sec-

tion and the lower side of the gate section to
the paper exit tray side, (but not discharged
completely.)

→ It is stopped once and switchback operation

is performed. (To the back copy)

Gear 20T

Process detection switch

Gear 38T

Gear notch

Gear pawl

Projection

Gear notch

Gear pawl

Projection

Gate OFF

Lower Side of Gate

Gate ON

DM-1505

6  –  7