Canon DADF-M1 Service Manual page 92

Chapter 4
4) Clean the top face (plastic film) [1] of the prism.
The surface of the prism coming in contact with paper is covered with plastic film. Be sure to clean the film.
3. Post-Separation Sensor, Prism
1) Remove the inside cover.
2) Remove the 2 screws [1], and detach the post-separation sensor [2]; then, clean the post-separation sensor using an air blower brush.
4-10
[2]
[1]
F-4-22
[1]
F-4-23
F-4-24
[1]