Lexmark X940e Owners Manual

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Charge
The Charge Roll places a uniform negative electrostatic charge on the surface of the drum. The drum surface is 
made of a photoconductive material that holds an electrical charge as long as the drum remains in darkness. 
Light striking the drum discharges the surface charge.
The charge roll is a conductive roll that is positioned slightly above the surface of the drum. The HVPS supplies 
the charge roll with two voltages; a negative DC charge...

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Exposure
The Printhead generates a beam of laser light. Image data received from the RIP card assembly modulates this 
beam, turning it on and off according to image information that is received from the host computer and software.
Through the use of a series of rotating and stationary mirrors within the Printhead, the beam scans the negative 
charged drum surface. Whenever the print controller sends a command to print a black pixel, the laser switches 
on...

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The toner adhering to the Magnet Roll is always in contact with the drum surface. When a less negative point on 
the drum (a discharged area) comes in contact with the more negative charged toner on the Magnet Roll, toner 
transfers from the Magnet Roll to that point on the drum. There is now a visible toner image on the drum surface. 
The image is called a developed image.
Transfer
As the paper travels between the 2nd transfer Roll and the transfer belt...

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is now stuck to the transfer belt due to the relative electrical differences between the negative electrical charge 
of the inner conductive layer of the drum and the positive electrical charge of the paper.
Cleaning 
The Cleaning Blade removes any toner that remains on the drum after the transfer process. The toner that the 
Cleaning Blade removes is collected inside the sealed PC Cartridge and reused.
Discharge
At both the start and the end of each...

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At the beginning of each individual printer cycle, the Printhead scans the surface of the drum, further discharging 
any residual DC charge that may be left on the drum.
Auto density sensing
The image density sensor assembly uses a reflection type sensor that detects a pre-placed toner patch and 
image on the transfer belt and outputs pulses when the central line of the patch image aligns with the central line 
of the detector. The sensor outputs pulses...

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Document scanning
The document scanning section of this machine consists of a scanner that reads a single-sheet document 
placed on the platen glass and a document feeder that can transport a multiple-sheet document and flip the 
sheets for two-sided scanning. 
This ADF employs a constant velocity transport system that scans images by feeding the document at a 
constant speed over the specified position (scan position) where the carriage (full/half rate...

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The exposure lamp is installed on the full rate carriage. As the full rate carriage travels, the document on the 
platen glass is scanned and exposed with the exposure lamp.
In conjunction with the full rate carriage, the half rate carriage travels half of the stroke of the full rate carriage.
The optical image of the exposed document is reflected by the scanner 1st mirror of the full rate carriage and 
directed to the scanner lens via the scanner 2nd...

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Pre-feed
In the pre-feed step, a document sheet is fed from the Feed roll to the ADF transport roll assembly. To correct 
the skew, side1 of the document sheet is thrust against the ADF transport roll assembly rotating in the reverse 
direction, and side2 is thrust against the ADF transport roll assembly at rest. 
With the pick roll at the down position (see Preparation for feed), the ADF feed motor assembly rotates in the 
reverse direction (CCW direction)...

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Scan control
Scanning of the image illuminated with the exposure lamp of the full rate carriage is controlled by changing the 
feed speed according to the copy magnification. 
The document sheet stopping at the scan feed reference position is then fed to the scan position when the scan 
signal is sent from the main unit of the machine after the predetermined time lapse following the paper detection 
at sensor (ADF registration). Upon receipt of the scan...

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Simplex document
For two simplex document sheets, feed is performed in the following sequence:
1. The first document sheet is fed to the ADF transport roll assembly. (see Pre-feed)
2. The document is fed to the ADF registration roll assembly, and then fed to the scan feed reference 
position. (see Pre-registration)
3. The document sheet is fed at the feed speed corresponding to the selected magnification, and the image 
on it is scanned with the exposure lamp...