This model uses a conventional mechanism in which paper comes in contact with the exposure glass during feeding. This is useful for dealing with adhesion of free dirt particles (paper scraps, etc.), as a self-cleaning mechanism using the paper.
On the other hand, sticky dirt adhering to the document sticks to the exposure glass, and may cause black lines in scanned images.
DF cross-section diagram
[A]: Sheet-through glass
[B]: Reading position
[C]: Original feed path
By changing SP4-020-001 (Dust Check > Dust Detect:On/Off), when dirt is detected at the reading position, the reading position may be changed to avoid the dirt.
If it cannot be avoided, an alert is displayed on the operation panel advising the user to clean the exposure glass.
[A]: Reading position
[B]: Exposure glass
[C]: Dirt
In this machine, the LED is moved to the right:
[A]: Initial reading position
[B]: Left frame
[C]: New reading position
Note
Dirt is detected when a document passes through, so the alert will not disappear until reading of the next document begins, even after exposure glass cleaning is performed.
- If the detected dirt is not on the exposure glass but on the background guide plate, the alert will not disappear even if the glass is wiped.
- The time required for the first copy is slightly (almost imperceptibly) longer.
- The detection threshold can be changed using SP4-020-002 (Dust Check > Dust Detect:Lvl). (The larger the value is, the smaller the dirt particles that can be detected.)
- Do not change the setting of SP4-020-003 (Dust Check > Dust Reject:Lvl).