Ricoh DF44 SPECIFICATIONS
DOCUMENT FEEDER
(Machine Code: A662)
24 February 1997 SPECIFICATIONS
1. SPECIFICATIONS
Original Size: Maximum: A3 or 11" x 17"
Minimum: A5 Lengthwise or 51/2" x 81/2"
Original Weight: 52 to 105 g/m2 (14 to 28 lb)
Original Feed: Automatic Feed - ADF mode
Semi-automatic Feed - SADF mode
Original Tray Capacity: 30 sheets - 80 g/m2 (20 lb)
Original Set: Face up, first sheet on top
Original Separation: Feed roller and friction belt
Original Transport: One flat belt
Copying Speed: 15 copies/minute
(A4 lengthwise or 81/2" x 11" lengthwise)
Power Consumption: 45 W
Dimensions (W x D x H): 590 x 443 x 87.5 mm (23.3" x 17.5" x 3.4")
(Not including the original table)
Weight: Approximately 7 kg (15.5 lb)
• Specifications are subject to change without notice.
Option
A662-1
COMPONENT LAYOUT 24 February 1997
2. COMPONENT LAYOUT
2.1 MECHANICAL COMPONENTS
1 2 3 4 65
1. Pulse Generator Disk
2. Friction Belt
3. Pick-up Lever
4. Pick-up Roller
5. Original Table
2.2 ELECTRICAL COMPONENTS
4
5
3
2
1
6
7
8
78910
6. Exit Roller
7. Transport Belt
8. Transport Belt Roller
9. Feed Roller
10. Relay Roller
9
10
11
A662V500.img
12
1. Pick-up Solenoid
2. Registration Sensor
3. Original Set Sensor
4. Feed Clutch
5. Pulse Generator Sensor
6. DF Motor
A662-2
A662V501.img
A662V502.img
7. Insert Original Indicator
8. SADF Indicator
9. Lift Switch
10. DF Main Board
11. DF Transformer
12. DF Interface Board
24 February 1997 ELECTRICAL COMPONENT DESCRIPTIONS
3. ELECTRICAL COMPONENT DESCRIPTIONS
Symbol Name Function Index No.
Motor
M1 DF Motor Drives all the document feeder components. 6
Solenoid
Pick-up Solenoid Energizes to press the pick-up lever against
SOL1
Clutch
CL1
Switch
SW1
Feed Clutch Turns on to transmit main motor rotation to
Lift Switch Informs the CPU when the DF is lifted and
the stack of originals in preparation for
original feed-in.
the feed roller.
also serves as the misfeed reset switch for
the DF.
1
4
9
Option
Sensors
S1
S2
S3
Printed Circuit Board
PCB1 DF Main Board Controls all DF functions. 10
PCB2
Transformer
TR1 DF Transformer Steps down the wall voltage to 25 volts ac. 11
LEDs
LED1
LED2
Pulse Generator
Sensor
Original Set Sensor Informs the copier CPU that originals have
Registration Sensor Sets original stop timing and checks for
DF Interface Board Interfaces between the copier main board
SADF Indicator Informs the operator that the SADF mode is
Insert Original
Indicator
Supplies timing pulses to the DF main board.
been placed and causes the Insert Original
indicator to go out.
original misfeeds.
and the DF.
available.
Turns off when the originals are inserted into
the original table.
5
3
2
12
8
7
A662-3
POWER DISTRIBUTION 24 February 1997
4. POWER DISTRIBUTION
A662D500.wmf
The document feeder uses two dc power levels: +24 volts, and +5 volts.
When the main switch is turned on, the DF transformer receives the wall
outlet ac power through the ac drive board and outputs 25 volts ac to the DF
main board. Then, the dc power supply circuit on the DF main board converts
the 25 volts ac input to +24 volts and +5 volts.
+24 volts is used by the DF motor, the pick-up solenoid, and the feed clutch.
+5 volts is used by other electrical components.
A662-4
24 February 1997 BASIC OPERATION
5. BASIC OPERATION
When the main switch is turned on, the DF CPU sends the "DF installed"
signal to the copier CPU. Receiving this signal, the copier CPU recognizes
that the document feeder is installed and sends the "DF confirmed" signal to
the DF CPU.
When originals are placed on the original table, the Insert Original indicator
turns off and the DF CPU sends the "original set" signal to the copier CPU to
inform that the originals have been set.
When the key is pressed, the copier CPU sends the "feed-in" signal to
the document feeder. On receipt of this signal, the DF CPU energizes the DF
motor, then the pick-up solenoid and feed clutch to feed in the bottom sheet
of the original stack onto the exposure glass. The pick-up solenoid and the
feed clutch remain energized until the original’s leading edge reaches the
registration sensor. The DF motor turns off shortly after the original’s trailing
edge passes the registration sensor. Then, the DF motor pauses and
reverses for a moment to align the edge of the original with the scale.
Option
Then the scanner starts to move (scanner start timing does not depend on
the progress of the original through the DF; it starts at a fixed time after the
key is pressed). When the scanner reaches the return position, the
copier CPU sends the "original change" signal to the DF CPU in order to feed
out the current original and feed in the next original.
A662-5
INTERFACE CIRCUIT 24 February 1997
6. INTERFACE CIRCUIT
A662D509.wmf
The copier CPU and the DF CPU communicate via the interface board using
fiber optics. The interface board changes the optical signals to electrical
signals (and vice versa).
A662-6
24 February 1997 ORIGINAL FEED
7. ORIGINAL FEED
7.1 ORIGINAL PICK-UP MECHANISM
[B]
[C]
[A]
Option
[D]
A662D502.img
After setting the originals on the original table, the originals contact the feeler
[A] of the original set sensor and cause the feeler to move out of the sensor.
The DF CPU then sends the original set signal to the copier CPU to inform it
that the document feeder will be used. When the key is pressed, the
pick-up solenoid [B] is energized. The original stack is then pressed between
the pick-up lever [C] and pick-up roller [D]. The rotation of the pick-up roller
advances the bottom original.
A662-7
ORIGINAL FEED 24 February 1997
7.2 ORIGINAL SEPARATION MECHANISM
[B]
[D]
[C]
[A]
[E]
[C][D][B]
A662D503.img
[E]
[A]
A662D504.img
The feed roller [A] and the friction belt [B] are used to feed in and separate
the originals [C]. Only the bottom original is fed because the friction belt
prevents any other originals from feeding.
Original feed starts when the pick-up lever [D] presses the original stack and
the pick-up roller [E] advances the bottom original of the stack. The feed
roller moves the original past the friction belt because the driving force of the
feed roller is greater than the resistance of the friction belt. The friction belt
prevents multiple feeds because the resistance of the friction belt is greater
than the friction between original sheets.
A662-8
24 February 1997 ORIGINAL FEED
7.3 ORIGINAL FEED-IN MECHANISM
[C]
[E]
[G]
[A]
[D]
[B]
[F]
A662D505.img
The DF motor [A] drives the feed roller [B], the pick-up roller [C], the relay
rollers [D], and the transport belt roller [E] via timing belts and a gear train.
The feed roller and the pick-up roller are controlled by the feed clutch [F], but
the relay rollers and the transport roller are directly driven by the DF motor.
The idler rollers [G] on the feed roller shaft are free from the shaft.
Option
When the key is pressed, the DF motor is energized and the relay rollers
and transport belt roller start turning. 100 milliseconds after the DF motor
starts turning, the pick-up solenoid and the feed clutch are energized. The
pick-up and feed rollers then start turning and carry the original between the
relay rollers and the idler rollers. The pick-up solenoid and the feed clutch are
de-energized when the original’s leading edge passes through the
registration sensor.
The DF motor remains energized to deliver the original to the exposure glass
until a certain number of pulses (10 to 25 pulses) after the original’s trailing
edge passes through the registration sensor. Then, the DF motor pauses and
reverses for 15 pulses to align the edge of the original with the scale.
To feed the second original, the DF motor starts rotating when the scanner
reaches the return position. (The copier CPU sends the original change
signal to the DF CPU.) At this time, the transport belt starts carrying the first
original on the exposure glass to the exit roller. The timing for when the
pick-up solenoid and the feed clutch are energized for the second original
depends on the length of the first original detected by the registration sensor.
A662-9
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