Xerox Phaser 3155 User Manual

							2
Chapter
Theory of Operation
In this chapter...
• Operational Overview
•Paper Path
Downloaded From ManualsPrinter.com Manuals 
						

							2-2Phaser 3140/3155/3160 Printer Service Manual
Theory of Operation
Operational Overview
The Phaser 3140/3155/3160 is a monochrome printer that has a single-pass laser 
design architecture, which offers mono print speed up to 24 pages per minute 
(ppm), and resolution up to 1200 x 1200 
dots-per-inch (dpi) image quality. The 
printer provides a USB interface for all models, and the 3160N supports 10/100 
Base-TX ethernet.
System Overview
The location of the printer’s primary functional components is shown in the 
following illustration.
s3160-065
Output Bin Full Sensor
Paper Exit Sensor
Paper Empty Sensor
Tray
Paper Feed Sensor
Cover Open Sensor
Manual Feed Sensor
Transfer Roller Manual Feed Slot
Print Cartridge Laser Unit
Fuser
Downloaded From ManualsPrinter.com Manuals 
						

							Phaser 3140/3155/3160 Printer Service Manual2-3
Theory of Operation
Paper Path
The media supplied from the Paper Tray is transported through the printer as 
shown in the illustrations below. Media fed from the manual feed slot enters the 
media path at the Feed Idle Roller.
Paper Feeding
The feeding mechanism consists of the manual feeder, Paper Tray, Pick Up Roller, 
Feed Rollers, and Holder Pad. 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.
s3160-082
Output Bin Full Sensor
Paper Exit Sensor
Paper Empty SensorPaper Feed SensorCover Open Sensor
Manual Feed Sensor
Pick Up Roller
Feed Roller
Feed Idle Roller
Manual Feed Slot
Downloaded From ManualsPrinter.com Manuals 
						

							2-4Phaser 3140/3155/3160 Printer Service Manual
Theory of Operation
Paper Tray
In the Paper Tray, paper is separated by the Holder Pad mounted to the center of 
the tray. Both the side guide and the rear guide can be adjusted for various paper 
sizes. The Paper Empty Sensor detects when the Paper Tray needs to be loaded 
with paper.
Tra y  H o l d e r  Pa d
Individual sheets are separated by the Tray Holder Pad in the Paper Tray. When 
paper feeds into the printer, it passes over the Tray Holder Pad Assembly which 
uses a spring loaded friction pad to separate the sheets of paper.
Manual Feeder
The manual feeder is used to hold non-st
andard or custom paper sizes and special 
media (envelopes, transparencies, etc.). The manual feeder can hold 1 sheet of 
paper or 1 envelope.
s3160-077
s3160-153
Downloaded From ManualsPrinter.com Manuals 
						

							Phaser 3140/3155/3160 Printer Service Manual2-5
Theory of Operation
Pick Up Roller
The Pick Up Roller is used to pick up and feed paper into the printer and remove 
static charge on the paper. The Pick Up Roller is driven by the Pick Up Solenoid.
Feed Roller (Registration)
The Feed Roller controls paper registration and guides the paper into the printer.
s3160-090
Pick Up Roller
s3160-089
Downloaded From ManualsPrinter.com Manuals 
						

							2-6Phaser 3140/3155/3160 Printer Service Manual
Theory of Operation
Drive Assembly
The Drive Assembly receives power from the Controller Board. The Drive Assembly 
consists of the main motor and ge
ar set mounted to a support plate.
• Motor: 24V DC
• Driving Frequency: 2200 rpm
s3160-084
3155 & 3160 3140
Downloaded From ManualsPrinter.com Manuals 
						

							Phaser 3140/3155/3160 Printer Service Manual2-7
Theory of Operation
Laser Unit
The Laser Unit is the core part of the Phaser 3140/3155/3160 and is controlled by 
the video controller circuitry of the Controller Board. The Laser Unit converts video 
data received from the Controller Board into an electrostatic latent image on the 
surface of the OPC drum. This is achieved by controlling the laser beam and 
exposing the surface of the OPC drum to the laser light. A rotating polygon mirror 
reflects the laser light onto the OPC drum. Each face of the mirror produces one 
scan line. The OPC drum rotates at the same speed as the paper feeding speed. As 
the OPC drum turns, the laser sc
ans creating the full page image.
The Horizontal Sync (HSYNC) signal is created when the laser beam from the Laser 
Unit reaches the end of the polygon mirror and the signal is sent to the Controller 
Board. The controller detects the HSYNC sign al and adjusts the vertical line of the 
image on paper. After the HYSNC signal is detected, the image data is sent to the 
Laser Unit to adjust the left margin on the paper.
Transfer Roller
The Transfer Roller applies a positive char ge to the rear surface of the paper. The 
negatively charged toner image on the Printer Cartridge OPC drum is attracted to 
the positive charge on the rear surface of the paper, causing the image to be 
transferred from the surface of the drum onto the paper. For more information, see 
“Print Cartridge” on page 2-8.
s3160-087
s3160-083
Downloaded From ManualsPrinter.com Manuals 
						

							2-8Phaser 3140/3155/3160 Printer Service Manual
Theory of Operation
Print Cartridge
The Print Cartridge is an integral unit containing the OPC unit and toner unit. The 
OPC unit consists of the OPC drum and charging roller. The toner unit consists of 
toner, supply roller, developing roller, and cleaning blade.
• Developing method: Non-magnetic 1 element contacting method
• Toner: non-magnetic 1 element shatter type toner
• Toner Life: 1,000 pages/2,500 pages (ISO 19752 Pattern/A4 Standard)
• Toner Residual Sensor: Dot count with CRUM(CRU Monitor)
• OPC cleaning blade
• Management of waste toner: Collects toner using the cleaning blade.
• OPC drum protecting shutter: No
• Toner CRUM reader: Identifies whether toner is Xerox branded toner or 
whether a non-Xerox Print Cartridge is installed.
s3160-076
Cleaning Roller
Cleaning Blade
Max. -350V
Max. -550V
Max. +5KV Max -1.4KV
Zener Diode
-100V
Charging Roller Laser 
V 0 : -720V
V L : -150V
Doctor Blade
Developing Roller
Supply Roller
Transfer Roller
OPC Drum
s3160-088
Downloaded From ManualsPrinter.com Manuals 
						

							Phaser 3140/3155/3160 Printer Service Manual2-9
Theory of Operation
Fuser
The Fuser consists of a Halogen Lamp, Heat Roller, Pressure Roller, Thermistor, and 
Thermostat. The Heat Roller transfers he
at from the lamp to the paper. The 
Pressure Roller adheres the melted toner to the media surface. The Thermistor and 
Thermostat monitor Fuser operating temperature.
Halogen Lamp
•Voltage
• 120V: 115 V ± 5%
• 220V: 230 V ± 5%
• Capacity: 750 Watt ± 25 W
Thermistor
The Thermistor detects the temperature of  the heating unit and feeds the data to 
the main processor.
Thermostat
When the Heat Lamp becomes too hot, the Thermostat cuts off power to the lamp 
to prevent overheating.
Heat Roller
The Heat Roller transfers heat from the lamp to the paper. As the paper passes 
between the Heat Roller and Pressure Rollers, the toner is melted and permanently 
fixed to the paper. The surface of the Heat Roller is coated with Teflon, so that 
toner does not stick to the surface.
Thermistor Thermostat
Heat Roller
Pressure Roller Halogen Lamp 
(inside Heat Roller)
Pressure Roller
(behind Heat Roller) 
s3160-086
Downloaded From ManualsPrinter.com Manuals 
						

							2-10Phaser 3140/3155/3160 Printer Service Manual
Theory of Operation
Pressure Roller
The Pressure Roller is made of a silicon resin and the surface is coated with Teflon. 
When media passes between the Heat Roller and the Pressure Roller, toner is 
melted and permanently fixed to the surface of the paper.
Safety Features
Several protection devices are used to prevent Fuser overheating:
• Hardware cuts off Fuser power when overheating is detected.
• Software cuts off Fuser power when overheating is detected.
• Thermostat cuts off power to the lamp.
Interlocks disable the Fuser, motor, and Laser Unit.
• Fuser power is cut off when the front cover is opened.
• Fuser cover temperature is maintained at less than 80° C.
Electrical Components
The printer’s major electrical components consist of these boards:
• Control Panel 
• Controller 
•Power Supply 
Controller
Power SupplyControl Panel
s3160-091
Downloaded From ManualsPrinter.com Manuals