HP laserjet 3390, 3392 all-in-one Manuale Di Servizio
Scanner operation
At power-on and periodically at other times, the scanner assembly moves systematically to locate its
home position. It then calibrates to a white strip located under the glass at the right end of the scan tub.
home position. It then calibrates to a white strip located under the glass at the right end of the scan tub.
If the all-in-one detects a document in the ADF when a copy or scan is initiated (from the software or
the 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.
the 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.
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 original document too far. When a document is inserted correctly,
the paper-present sensor detects its presence.
preventing the user from inserting the original document too far. When a document is inserted correctly,
the paper-present sensor detects its presence.
The standard operation of the ADF consists of the pick, feed, and lift steps.
Pick: When it receives a copy or scan command, the ADF motor engages the gear train to lower the
pickup-roller assembly and raise the stack-stop. The first roller, called the pre-pick roller, moves the top
few sheets forward into the ADF. The next roller is the pickup roller. This roller contacts the ADF
separation pad, which separates multiple pages into single sheets.
pickup-roller assembly and raise the stack-stop. The first roller, called the pre-pick roller, moves the top
few sheets forward into the ADF. The next roller is the pickup 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, the form sensor, which is a set
distance from the ADF glass, detects the sheet. This alerts the scanner to start when the page reaches
the glass. The scanner acquires the image, one raster line at a time, until it detects the end of the page.
The page is then ejected. The pick and feed steps are repeated as long as paper is detected in the ADF
input tray.
distance from the ADF glass, detects the sheet. This alerts the scanner to start when the page reaches
the glass. The scanner acquires the image, one raster line at a time, until it detects the end of the page.
The page is then ejected. The pick and feed steps are repeated as long as paper is detected in the ADF
input tray.
Lift: When no more paper is detected in the ADF input tray and the form sensor detects the trailing edge
of the last page, the last sheet is ejected and the motor turns in a sequence that lifts the pick roller
assembly to standby (paper-loading) mode again.
of the last page, the last sheet is ejected and the motor turns in a sequence that lifts the pick roller
assembly to standby (paper-loading) mode again.
The ADF will not function when the ADF cover is open. The paper path is incomplete if the ADF cover
is lifted from the glass.
is lifted from the glass.
ENWW
Scanner and ADF functions and operation
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