Frame Detection Unit - Canon imageFORMULA DR-X10C Service Manual

5. Frame Detection Unit

This machine has a dedicated frame
detection unit detecting the document frame
for auto-size detection and skew correction.
The conventional machines detected docu-
ment size or angle from image data from the
reading unit to process images. By installing a
Document
The frame detection unit consists of a
sensor assembly including 2 CIS PCBs, a
frame detection guide including a reading
glass, and other parts (ink pad, light guide) not
associated with the frame detection function.
The CIS PCB contains an A4/LTR 600dpi
1-line CMOS image sensor. The reading
width of this machine is covered by assem-
bling 2 CIS PCBs. The resolutions that are
actually read are 300dpi for main-scanning
direction and 50dpi for sub-scanning direc-
tion.
COPYRIGHT © CANON ELECTRONICS INC. 2008
Frame detection
Registration
guide
roller
Sensor assembly
Figure 2-205
CANON DR-X10C FIRST EDITION
CHAPTER 2 FUNCTION & OPERATION
sensor to read
high-speed scanning is realized and disap-
pearance of an image can be prevented when
there is a dark area at the periphery of a
document.
A sectional view of the frame detection
unit is shown below.
Reading glass
CIS PCB
The light source is a yellow-green LED
and is mounted on the frame LED PCB which
is connected to the main drive PCB of the
upper unit. Light from the LED passes through
a slit and enters an image sensor. Reflected
light is used to read images and transmitted
light is used to detect the frame. Thus, the
outer frame of the document can be detected
correctly even if there is a dark area at the
periphery of a document.
the document frame,
2-13