Canon FAX-L1000 - Manual (Page 179)

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FAX-L1000 Chapter 3: Technical Reference
2.3.2 Optical section
a) Functions
a-1) Document scanning
For document scanning, the Contact Sensor (CS) horizontally scans documents up to LTR
size 8.42" (214mm)(B4 size 10.00" (254mm) for AE) at a horizontal scanning resolution
of 8 dots/mm (Standard, Fine and Superfine) or 16 dots/mm (Ultrafine).
Vertical scanning resolution is fixed by selecting resolution button on the operation panel.
The document scanning speed changes according to the resolution setting, and scanning
will be done at either 97.79 lines/inch (3.85 lines/mm) for Standard, 195.58 lines/inch (7.7
lines/mm) for Fine, and 391.16 lines/inch (15.4 lines/mm) for Superfine and Ultrafine. The
scanned data are sent to the SCNT board, and image processing carried out by the image
processing IC (UHQ 6.6). When this IC is set for Text/Photo, areas of the document that
contain photographs are automatically processed with 64 gradations of gray, rather than
just two, black and white. This results in a much better reproduction of the photograph.
a-2) Prescanning
The variation of contact sensor output during document scanning is corrected by the
prescan function.
a-3) Automatic slice level
The slice level for determining the white and black areas is set automatically to scan
density correctly regardless of the document paper color.