Samsung SCX 4200-XAA Operation Instruction & Installation

System Overview

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3. System Overview

This chapter describes the functions and operating principles of the main components.

3.1 System Outline

3.1.1 Front View

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3.1.2 Sensor

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3.1.3 Control Panel

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3.1.4 System Layout

SCAN PART

Paper Input (Cassette)

Paper Input (Manual Feeder)

Paper Out (Face Down)

Paper Empty Sensor (Manual)

Paper Empty Sensor (Cassette)

Paper Feeding Sensor

Paper Exit SensorPaper Out (Face Up)

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3.1.4.1 Paper Feed Mechanism

The printer has a universal cassette which automatically loads paper and a manual feed which supplies paper
single sheet at a time. The cassette has a friction pad which separates paper to ensure single sheet feeding, and it
has a sensor, which checks when the paper tray is empty.

- Feeding Method: Universal Cassette Type

- Feeding Standard: Center Loading

- Feeding Capacity: Cassette-250 sheets (75g/m2 , 20lb paper standard)
Manual 1 sheet (Paper, OHP, Envelop, etc.)

- Paper detecting sensor: Photo sensor

- Paper size sensor: None

3.1.4.2 Transfer Ass’y

This consists of the PTL (pre-transfer lamp) and the Transfer Roller. The PTL shines a light onto the OPC drum.
This lowers the charge on the drum’s surface and improves transfer efficiency.

The transfer roller transfers toner from the OPC drum surface to the paper.

- Life expectancy: Over 50,000 sheets (at 15~30°C)

3.1.4.3 Drive Ass’y

A gear driven power unit. The motor supplies power to the paper feed unit, the fuser unit, and the toner cartridge.

3.1.4.4 Fixing Part(Fuser)

Heat Lamp type used on 220V Export models and all 110V models.

The Heat Lamp type fuser consists of the Heat Lamp, Heat Roller, Pressure Roller, Thermistor, and Thermostat. It
fixes toner to the paper using pressure and heat to complete the printing job.

1)Heat Lamp power cut-off (Thermostat)

The thermostat is a temperature sensing device, which cuts off the power to the heat lamp to prevent overheating
fire when the heat lamp or heat roller overheats.

2)Temperature Detecting Sensor (Thermistor)

The Thermistor detects the surface temperature of the heat roller, this information is sent to the main processor
which uses this information to regulate the temperature of the heat roller.

3) Heat Roller

The surface of the Heat Roller is heated by the Heat Lamp. As the paper passes between the Heat and Pressure
rollers the toner is melted and fixed permanently to the paper. The surface of the roller is coated with Teflon. This
ensures that toner does not adhere to the roller surface.

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4) Pressure roller

The Pressure Roller mounted under the heat roller, it is made of a silicon resin, and the surface of the roller is
tubed with Teflon. This ensures that toner does not adhere to the roller surface.

5) Safety Relevant Facts

• To prevent overheating

- 1st protection device: Hardware cuts off when overheated

- 2nd protection device: Software cuts off when overheated

- 3rd protection device: Thermostat cuts off mains power to the lamp.

• Safety device

- Fuser power is cut off when the front cover is opened

- LSU power is cut off when the front cover is opened

- The temperature of the fuser cover's surface is maintained at less than 80ºC to protect the user and a
caution label is attached where the customer can see it easily when the rear cover is opened.

3.1.4.5 Scanner Unit

• Scan Image Controller

1.Scan Line Time : 1.63ms

2.Scan Resolution : Color : Max 600DPI

3.Scan Width : 216mm

4.Function

- White Shading Correction

- Gamma Correction

- CIS Interface

- 256 Gray Scale

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CIS Operating Part: CIS use +3.3V

- CIS Max Operating Freguency: 5MHz

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3.1.4.6 LSU (Laser Scanner Unit)

This is the core of the laser printer. It converts the video data received from the computer 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. Arotating polygon mirror reflects the laser light onto the OPC and each
side of the mirror is one scan line. The OPC drum turns as the paper feeds to scan the image down the page.

The /HSYNC signal is created when the laser beam from LSU reaches the end of the polygon mirror and this
signal is sent to the controller. The controller detects the /HSYNC signal to adjust the vertical line of the image on
paper. In other words after the /HSYNC signal is detected the image data is sent to the LSU to adjust the left margin
on the paper.

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3.1.4.7 Toner Cartridge

The toner cartridge is an integral unit containing the OPC unit and toner unit. The OPC unit consists of the OPC
drum and charging roller, and the toner cartridge unit consists of the toner, supply roller, developing roller, and
blade (Doctor blade)

- Developing Method: Non magnetic 1 element contacting method

- Toner: Non magnetic 1 element shatter type toner

- The life span of toner: 3,000 sheets (ISO standard)

- Toner remaining amount detecting sensor: No

- OPC Cleaning: Electrostatic process

- Management of waste toner: Electro static process(Cleanerless Type)

- OPC Drum protecting Shutter: No

- Classifying device for toner cartridge: ID is classified by interruption of the frame channel

0.22mW

-970V

-430V

-580V

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3.2 H/W Structure and Descriptions

SCX-4200 is roughly made up Main Control part, Operation Panel part, Scanner part, PC interface part and
Power part. Each Part is separated Module which focus on common and standard design of different kind products.
The main control part is 1 CPU,1 board adopting Chorus 2 Chip which is exclusive MFP ASIC . Scanner part is
composed Platen and is connected with Main Cantroller by Harness.

3.2.1 CPU Part

1) CPU : Use 16/32Bit RISC Processor, Chorus 2,which is exclusive controller to execute Printer and to execute

operation block by flash memory within system program, and to control whole system.

- Main function block

- Completely Integrated System for Embedded Applications,

- 16/32 Bit Risc Architecture, Efficient and Powerful ARM7 Core.

- LSU Interface Module for Interfacing PVC with LSU

- 5 Channel General Purpose DMA Controllers for High Speed I/O

- Operation Frequency: System: 66MHz, Bus: 66MHz

- Operation Voltage : 3.3V

2) Flash Memory : Record System Program, and download System Program by PC INTERFACE..

- Size: 1M Byte

- Access time: 70 nsec