6.4 TASK -- REPLACEMENT OF WHITE BACKGROUND
A piece of white mylar is mounted on the underside of the scanner lid to provide a uniformly
bright and clean background for all documents. In time, however, this background may be
damaged and will need to be replaced . It is a simple job, but for best results, it requires the
efforts of two people.
The goal to keep in mind while performing this task is that you want to provide a clean smooth
background which presents no edges.
Equipment, Tools & Materials Required:
• Pre-cut White Mylar Background (Scangraphics Part Number 64163-2)
• AWG 16 wire (about 60 inches long)
• Very sharp small blade utility knife.
Procedure for Replacing White Background:
1. Lift the scanner lid, take out the top pressure rollers and remove the document guide
plate.
2. Remove the old background from the document guide, be sure to clean away any debris
from the old mounting materials.
3. Place the new background against the plate so that the top edge is aligned with the front
roller cut-outs and centered on the plate.
4. Peal off the backing tape from the pressure sensitive tape on the white background and
secure the top edge to the plate.
5. If misplacement occurs, use a new piece of white background and start again.
6. To help provide pressure against the document so it is flat against the camera window, a
bulge or dome is created in the mylar. This is done by placing the length of wire under
the mylar, close to the top taped edge. Tape the ends of the wire temporarily. This part is
tricky because of the wire underneath the mylar, but it is essential that the taping and the
mylar be uniform to prevent inconsistencies in the background and pressure.
Remember, you can not remove the tape and start over if there is a problem. Patience
and steady hands are required.
7. Once the bottom edge is secure, you can remove the wire by untaping it and pulling it out
one side.
8. Now, using the utility knife, carefully trim the mylar and tape away from the openings for
the document sensors.
9. Replace the document guide and the top pressure rollers. The procedure is now
completed.
