Xerox Phaser 3450, Руководство по обслуживанию, Страница: 136 / 155

11-5
CIRCUIT DESCRIPTION
Service Manual
11.2 System Composition
11.2.1 System Configuration
11.2.1-1 Video Controller Board
Video Controller Board receives image data from the Host Computer then convert into Bitmap (Binary) image or directly
receive Bitmap image from the Host and connect to the input/output section to process data and print out the created
image.
11.2.1.2 SMPS Board (Engine)
AC is received to create the needed quantity of +5V,+3.3V and +24V DC level. Adequate amount of voltage is supplied to
each units. It also supplies AC voltage to the Heat Lamp of the fixed unit.
11.2.1.3 Engine Board (SMPS)
Engine Board uses the voltage received from SMPS to control electric photo process, which is the basic operation principle
of LBP. Detailed explanation on each composition elements are in the section 2.4 Engine Controller.
11.2.1.4 HVPS Board
HVPS board creates optimum image formation condition by supplying High Voltage from THV/MHV/Supply/Dev to the developer.
11.2.1.5 Develop Unit
Develop unit creates image using electric photo process. This unit consists of Charge Roller, OPC drum, Developer Roller,
Supply Roller and Toner.
11.2.1.6 LSU(Laser Scanning Unit)
LSU is controlled by Video Controller. It is the core part that forms charge ripple at the OPC drum by applying video data
from the video controller, exposure from OPC drum and the rotation principle of polygon mirror. OPC drum synchronously
rotates with the paper feeding speed. At this point, when the laser beam within the LSU reaches the edge of the polygon
mirror, /HSYNC signal is sent to the engine. The engine then detects the /HSYNC signal and properly adjust the vertical
image lines of the paper. The image data is sent to the LSU at the set time, followed by /HSYNC signal detection to adjust
the left margin. It becomes one of the lines scanned by one side of polygon mirror.
11.2.1.7 Transfer Section
Transfer unit is composed of PTL(Pre-Transfer Lamp) and Transfer Roller PTL investigates Beam from OPC drum and
decreases the electric potential and the toner adhesion to increase the transfer efficiency. The transfer roller transfers the
toner from the OPC drum to the paper surface.
11.2.1.8 Printing Section
Printing unit is composed of Heat Lamp, Heat Roller, Pressure Roller, Thermistor and Thermostat. Printing unit completes
the printing job by applying toner from the transfer unit with pressure and high temperature to stick to the paper.
11.2.1.9 Driving Section
Driving unit applies Bi-Polar Motor and controls current in 2-2.
11.2.1.10 Cover Open Board
Cover Open board has Cover Open Sensing unit, which shuts off Main Motor, LSU, Fan, Clutch and +24V when the front
cover is opened.
11.2.1.11 Toner Sensor Board
Toner Sensor board transfers various signals(Cartridge detect, paper detect, paper size detect etc.)
11.2.1.12 Cassette Detect Board
Various signals(Feed Clutch, MP-empty, Cassette detect) connect to the Video Controller Board through the Cassette Detect
Board.