Lead Edge And Trailing Edge Erase; Side Erase - Ricoh FT5540 Service Manual

4.2 LEAD EDGE AND TRAILING EDGE ERASE

The entire bank of erase lamps turns on to erase the drum before and after the image area.
Leading edge erase overlaps the paper and the image slightly. The leading edge margin helps
prevent fusing jams by making it easier for the stripper pawls to separate the paper from the
hot roller. Trailing edge erase turns on about 2 mm after the trailing edge of the copy paper.
The width of the lead edge margin can be adjusted by SP mode #41.
Mode No.
41 Lead Edge
Erase Margin
Adjustment
During image density detection cycles (once every ten cycles), the center block of erase
lamps turns off long enough for the sensor pattern to be developed [g].

4.3 SIDE ERASE

Side erase overlaps the image slightly on either side. The CPU calculates the side erase
margins from the paper size and the selected reproduction ratio. As the paper is fed to the
center of the drum, the LEDs for side erase turn on in pairs. The erase lamp is not used for
side erase with A3 or 11 x 17 paper. For these paper sizes, side erase occurs due to the end
block covers of the charge corona.
The CPU adjusts the side erase margin to be as near as possible to the actual image size,
even when using the zoom function. However, since the erase lamp LEDs will not work in
precise one millimeter intervals, the side erase margin varies slightly depending on the
reproduction ratio.
SP 27 decreases the side margins by 5 mm.
Function
Adjusts the
lead edge
margin
Data Factory
Setting
0 - 15 8
2-23
31 August 1989
Comments
0.6 mm per step
(max. -4.8 mm to
+4.2 mm)