User guide

EN Scanner and ADF functions and operation 81
The image data is collected in the scanner formatter where it is
processed and sent to the formatter. The formatter then handles the
image data, outputting it as a copy, sending it through the LIU as a
fax, or directing it to the computer as scanner output.
The image data collected is 600 pixels per inch. Each pixel has 8 bits
for each of the three colors (256 “grey” levels for each color) or a total
of 24 bits per pixel (24-bit color).
Scanner Operation
Upon power-up and periodically at other times, the scanner assembly
moves systematically to locate its home position. It then calibrates
itself to a white label located under the glass at the right end of the
scan tub.
If a document is detected in the ADF when a copy or scan is initiated
(from software or control panel), the scan module moves to the left
side of the scan tub and stops. The image is acquired as the paper is
fed through the ADF past the scanner module.
If no document is detected in the ADF, or if the model does not have
an ADF, the scan module acquires the image from the flatbed glass
while slowly moving within the scan tub.
ADF Operation
Standby (paper loading) mode: In standby mode, the pickup roller
is up and the stack stop is down, preventing the user from inserting
the document original in too far. When a document is inserted
properly, it is detected by the paper-present sensor.
The standard operation of the ADF consists of the pick, feed, and lift
steps.
Pick: Upon receipt of a copy or scan command, the ADF motor
engages the gear train to lower the pick roller assembly and raise the
stack-stop. The first roller is called the pre-pick roller and serves to
move the top few sheets forward into the ADF. The next roller is the
pick roller. This roller contacts the ADF separation pad which
separates multiple pages into single sheets.
Feed: The single sheet continues through the path. Along the way, it
is detected by the form sensor a set distance from the ADF glass.
This alerts the scanner to start when the page reaches the glass. The
scanner acquires the image, one raster line at a time, until the end of
the page is detected and the page is ejected. The pick and feed steps
are repeated as long as paper is detected in the ADF input tray.