Lexmark X940e Owners Manual

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Sensor (ADF pre-registration)
ADF feed motor assembly
Sensor (sheet through)
ADF registration
motor
Sensor (ADF registration)
Sensor (ADF inverter)
Sensor (ADF APS 1)Sensor (ADF APS 2)Sensor (ADF APS 3)Inverter solenoid assembly 
						

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Control 
Document size detection at scanner unit assembly
The width (fast-scan-directional size) of the document sheet on the Platen Grass is detected with the CCD 
image sensor, and the length (slow-scanning-directional size) is detected with the sensor (platen length APS 1) 
and the sensor (platen length APS 2).
Document size detection timing
The size of the document sheet on the platen glass is detected at the following timings:
•When the Platen Cover (ADF) is closed
•When the START button is pressed with the Platen Cover (ADF) open
Identification of standard document sizes
The width of the document sheet is detected in millimeters with the CCD image sensor to determine the size in 
the fast scanning direction. With respect to a pair of documents whose sizes in the fast scanning direction are 
the same, the document size is determined by detecting paper presence/absence at the positions of sensor 
(platen length APS 1) and sensor (platen length APS 2) (e.g., A4LEF vs. A3SEF; 8.5x11SEF vs. 8.5x13SEF).
The standard document sizes to be identified by the same given detection information are defined on an 
area-by-area basis. Each area is to be set in the system data.
The figure below shows the positional relationships among the scan position of the CCD image sensor and the 
positions of sensor (platen length APS 1) and the sensor (platen length APS 2).
CCD scan position
Sensor (platen
length APS 1)
Sensor (platen
length APS 2) 
						

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Shown below are the combinations of document size, detection range in the fast scanning direction, and 
sensors. 
Document SizeWidth (Fast scanning 
direction: mm)Length (Slow scanning direction) Area
Fast 
scanning 
WidthDetection 
RangeSensor (platen 
length APS 1)Sensor (platen 
length APS 2)012
Japanese Post 
Card SEF100.0 90–115 Off Off X X N
Post Card SEF 101.6NOX
A6 SEF 105.0ONO
5 X 7 SEF 127.0 115–138 Off Off N O N
B6 SEF 128.0ONO
5.5 X 8.5 SEF 139.7 138–163 Off Off X O X
A5 SEF 148.0OXO
Japanese Post 
Card LEF148.0XXN
Post Card LEF 152.4NNX
B5 SEF 182.0 163–188 On Off O X O
16kai SEF 194.0/
195.0188–202 On/Off Off X X
X*3
A5 LEF 210.0 202–213 Off Off O X*3O
A4 SEF 210.0 On On/Off O X
*3O
5.5 X 8.5 LEF 215.9 213–226 Off Off O
*1OX*3
8.5 X 11 SEF 215.9 On Off O*1OX*3
8.5 X 12.4 SEF 215.9 On On N N X
8.5 X 13 SEF 215.9ON X
8.5X 14 SEF 215.9NOX
8 X 10 LEF 254.0 226–262 Off Off N X
*4X
B5 LEF 257.0 O
*2XO
B4 SEF 257.0 On On O X O
Executive LEF 266.7 262–267 Off Off X O
*4X
8 X 10.5 LEF 266.7 X
*2NX
16kai LEF 267.0/
270.0267–275 Off Off X X X
*3
8kai SEF On On/Off X X X*3
8.5 X 11 LEF 279.4 275–289 Off Off O*2OX*5
11 X 14.9 SEF 279.4 On On N N X
11 X 17 SEF 279.4OOX
*5 
						

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O: Detectable by default.
N: Detectable by replacing the document size marked as O with the system data having the same detection 
information.
X: Not detectable.
*1: Changeable from 5.5 X 8.5 LEF to A5 LEF, or from 8.5 X 11 SEF to A4 SEF by the system data.
*2: Changeable from B5 LEF or 8.5 X 11 LEF to 8 X 10.5 LEF by the system data.
*3: Detectable by setting the system data.
*4: Changeable from Executive LEF to 8 X10 LEF.
*5: Changeable from A4 LEF to 8.5 X 11 LEF, or from A3 SEF to 11 X 17 SEF.
ADF document size detection
The ADF first detects the document size when the document is set on the document tray, and detects the 
document size again when the document travels.
When the document is set on the document tray, the document size is determined by a combination of ON/off 
status of the sensor (ADF APS 1), sensor (ADF APS 2) and the sensor (ADF APS 3) for detecting the document 
width (in the fast scanning direction) and ON/off status of the sensor (document tray length 1) and the sensor 
(document tray length 2) for detecting the document length (in the slow scanning direction). 
The document width is detected according to whether the sensor (document tray width 1), sensor (document 
tray width 2) and the sensor (document tray width 3) are shielded (blocked) or unshielded (unblocked) by the 
document tray size actuator moving in conjunction with guides of the document tray.
The document length is detected according to whether the sensor (document tray length 1) and the sensor 
(document tray length 2) are shielded (blocked) or unshielded (unblocked) by the document set on the tray.
When different-sized sheets are stacked on the tray, the document size is determined by using the largest 
possible combination of width and length obtained from the sheets. A4 LEF 297.2 289–307 Off Off O O O
*5
A3 SEF 297.2 On On O O O*5
Document SizeWidth (Fast scanning 
direction: mm)Length (Slow scanning direction) Area
Fast 
scanning 
WidthDetection 
RangeSensor (platen 
length APS 1)Sensor (platen 
length APS 2)012 
						

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The standard document sizes to be identified by the same given detection information are defined on an 
area-by-area basis. Each area is to be set in the system data.
ADF side 1ADF side 2
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The table below shows the combinations of document sizes and sensors. 
O: Detectable
X: Not Detectable
While the document is traveling, document size detection is performed as follows.
When the document goes through the sensor (ADF APS 1), sensor (ADF APS 2) and the sensor (ADF APS 3), 
the document width in the fast scanning direction is detected according to the combination of shielded/
unshielded status of each sensor.
The document length in the slow scanning direction is detected by the scanning time measured from the 
moment when the document starts scanning from the wait position (see Pre-registration) until its tail end passes 
through the sensor (ADF sheet through). 
Document scanning steps
Document SizeWidth (Fast scanning direction)
Sensor (document tray width *)Length (Slow scanning direction)
Sensor (document tray length *)Area
1 2 3 1 2 012
5.5 X 8.5 SEF Off Off Off On Off X O X
A5 SEFOXO
B5 SEF Off Off Off On Off X X O
8 X 10 SEFXOX
8 X 10.5 SEFOX X
A5 LEF Off On Off Off Off O O O
A4 SEF On Off O O O
5.5 X 8.5 LEF Off On On Off Off O O O
8.5 X 11 SEF On Off O O O
8.5 X 13 SEF On On O X X
8.5 X 14 SEFXOO
8 X 10 LEF On Off On On Off O O O
B5 LEF Off Off OOO
B4 SEF On On O O O
8 X 10.5 LEF On Off Off On Off O O X
Executive LEF  Off Off O O X
16kai LEFXXO
8kai SEF On On O O O
8.5 X 11 LEF On On Off On Off O O O
11 X 17 SEF On On O O O
A4 LEF On On On On Off O O O
A3 SEF On On O O O 
						

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The CCD image sensor is used to read image data from the document. To stabilize the read image data, the 
CCD image sensor output is adjusted and the read image data is compensated.
The CCD image sensor output is adjusted with the gain/offset voltage of the amplifier in the analog circuit. This 
adjustment includes AGC and AOC.
In addition, the reference data is collected and compensation values are calculated to compensate for the read 
image data. This compensation includes shading compensation, white variation compensation, and black 
variation compensation. These adjustment and compensation steps are detailed below.
The reference data is prepared by reading the image data of a white reference plate via the CCD image sensor.
AGC (auto gain control): white level coarse adjustment
AGC is a function that adjusts the gain so that the CCD image sensor output becomes as specified when the 
exposure lamp is on. AGC functions as a coarse white level adjustment of the image. AGC is performed at 
initialization.
AOC (auto offset control)
AOC is a function that adjusts the offset voltage so that the CCD image sensor output becomes as specified 
when the exposure lamp is off. AOC functions as a black level adjustment of the image. AOC is performed at 
initialization.
Shading compensation
Shading compensation is a function that compensates for pixel-to-pixel sensitivity variation of the CCD image 
sensor and pixel-to-pixel output variation of the CCD image sensor that is caused by illumination non uniformity 
in the fast scanning direction of the optical system.
Shading compensation is performed at initialization.
White level variation compensation
White level variation compensation is performed to compensate for variation in light quantity of the exposure 
lamp.
White level variation compensation includes two processes: acquisition of white variation compensation 
reference data during initialization and white variation compensation during document scanning.
For the ADF, white level variation compensation is performed at both the white reference plate position of the 
platen and at the white reference plate of the scanner read position.
Black level variation compensation
Black level variation compensation is performed to compensate for variation in black level that is caused by the 
temperature drift of the CCD image sensor and analog circuit.
Black level variation compensation is performed during document scanning.
For the platen, black level variation compensation is performed at the white reference plate position of the 
platen. For the ADF, black level variation compensation is performed at the scanner read position. 
						

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TTM theory 
						

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Media transport 
Media transport path
Media is supplied from tray 2, tray 3 or tray 4, and is transported to the printer along the media transport path 
shown below.
Pick rollPick roll
Separation rollSeparation roll
Feed roll
Transfer belt 2nd transfer roll assembly
Heat roll
Pressure roll
Fuser unit ASM
Standard media
exit roll assembly
Duplex media transport roll ASM
Duplex mediaCenter transport
roll ASM
Tray 3Tray 4
Feed roll
Tray module media Transport roll ASM
Media transport roll ASM
Registration roll ASM
Standard media exit
Pick roll
Separation roll
Feed rollTray 2 
						

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Media transport path
The following is a cross section of the printer and the tandem tray module, showing the main components 
directly associated with the media path and transport.  
Functions of main components
When the TTM is installed under the printer, additional trays are available.
Media tray assembly
It is necessary to adjust the rear side guides in the media tray assembly to match the media size.
Rear media guide
The rear media guide can be adjusted to different media sizes by moving it to the front or rear. The guide comes 
into contact with the rear edge of the media and holds it in position.
Tr a y  2
1TM (optional)
Media transport roll assembly
Tr a y  2
Tr a y  3
Tr a y  4
ADF and Scanner
MPF
Tr a y  1
Tr a y  2
Tr a y  3Tr a y  4
3TM (optional)
Finisher
(optional) Booklet maker unit
(optional)
Standard media exit
roll assembly
Fuser exit
roll assembly
Duplex media
transport roll
assembly
2nd transfer
roll assembly
Bridge unit assembly
(included with finisher)
Tray module transport
roll assembly
TTM
Pick roll
Feed roll
Separation roll
Registration
roll assembly
Tray module transport
roll assembly
MPF pick roll
Tray 4 transport roll assembly
Finisher media entrance
roll assembly
Upper media exit
roll assembly Upper media
transport roll assembly
Buffer roll assembly
Lower media exit
roll assembly
Booklet media
transport roll assembly
Booklet media
entrance roll assembly
Booklet media
exit roll assembly
Booklet folding
roll assembly
Media eject
roll assembly
Fuser
Bridge unit bin exit
roll assembly