Canon PC940 Service Manual - Page 40

CHAPTER 2 BASIC OPERATION STBY (standby) INTR (initial rotation) AER (AE rotation) SCFW (scanner forward) SCRV (scanner reverse) LSTR (last rotation) Period • From when he power switch is turned on to when the Copy Start key is pressed. • From when LSTR ends to when the Copy Start key is pressed. Description Waits until the Copy Start key is pressed. From when the Copy Start key is Removes residual charges from the pressed to when the scanner moves for- photosensitive drum, thereby ensuring ward. a stable drum sensitivity. While the scanner moves forward about Measures the density of the original. 10 cm and then moves it in reverse. While the scanner is moving forward. • The distance varies according to the selected copy size and reproduction ratio. • The forward speed varies according to the selected reproduction ratio. Illuminates the original by the scanning lamp, and the reflected optical image is projected to the photosensitive drum through mirrors and lenses. While the scanner is moving in reverse. • The reverse speed is about 3.3 as fast as the forward speed used in Direct. From when SCRV ends to when the main motor stops. Moves the scanner to the home position in preparation for the next copying run. Neutralizes the drum surface potential as post-processing. Table 2-101 2-4 COPYRIGHT © 1999 CANON INC. CANON PC800s/900s REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)