Xerox 3150 - Phaser B/W Laser Printer, Service Manual

Page: 27 / 116

Summary of Product
Service Manual 4-5
4.2.2 System Layout
4.2.3 Paper Feed
The paper feed system consists of a 250- sheet main paper tray (Tray 2), a multi-purpose paper tray (Tray 1), pickup
rollers, friction pads and feed rollers. The rollers and sensors in the paper feed path control paper registration and
guide the paper through the image transfer, image development, image fusing and exit assemblies. The paper path has
an anti-static connection to ground to eliminate problems due to static charge on the paper.
1. Paper separation method
Individual sheets are separated in the tray using the ‘friction pad’ method. When paper feeds into the printer it
passes over a spring loaded friction pad that separates the sheets of paper.
2. Paper tray (cassette)
The paper trays use a ‘center loading’ method. There are no paper size sensors, instead a software process is used
to detect the size of the first sheet of paper as it is fed through the printer. Both the rear and side paper guides are
adjustable for various paper sizes.
There is a ‘Paper Empty’ sensor which detects the presence of paper (Capacity: 250 sheets).
There is an indicator flag on the front of the tray which indicates the amount of paper remaining.
3. Pick-up roller
The pick-up roller is used to pick and feed paper into the printer. It also is used to remove any static charge on the
paper.
4. Tray1/MPT
The multi-purpose tray is used to hold non-standard or custom paper sizes and special media (envelopes,
transparencies, etc.). There is an MPT paper empty sensor. The MPT uses a friction pad method to ensure paper
separation and can hold a maximum of 50 sheets of paper or envelopes.
5. SCF (Second Cassette Feeder) or Tray 3
The optional third tray unit is universal with the second main tray and also has a capacity of 250 sheets.
PIC
K/
R
L S U
Toner Cartridge
PR
Fuser
EXIT
Sensor
OPC
CR
DR
SR
TR
FR
1
1
2
2
3
6
3
4
Cassette
Manual Feeder
Transfer Roller
5
6
5
Fuser
LSU(Laser Scan Unit)
Toner Cartridge
4
MP Sensor MP Sensor