Black Detection Circuit And Edge/Line Width Detection Circuit - Canon 1130 Service Manual

F. Black Detection Circuit and Edge/Line Width Detection Circuit
The black detection and edge/line width detection circuits perform the following image
processing using RGR signals:
1. Black Detection
Identifies the color of the pixel in question, and generates its color code.
2. Edge Detection
Detects whether the pixel in question is the edge of an input image or not.
3. Line Width Detection
Detects the width of the line forming the edge of an input image.
Part 2>Chapter 3>2.9
1. Black detection (ACS) is performed using the black detection signal
2. The black detection signal (ACSROI), edge signal (EDGE), and line width
REF.
COPYRIGHT © 2002 CANON INC.
IP-MAIN PCB
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Figure 4-406
(ACSROI) generated during pre-scanning.
signal (LWTH) from the black detection circuit and edge/line width
detection circuit are used to generate UCR signals and to detect black
characters, determine the level of sharpness processing, and to identify black
originals (ACS).
CANON CLC1100/1130/1150/1160/1180 REV.2 FEB. 2002 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 4 IMAGE PROCESSING SYSTEM
Black detection
Line width
detection
ACSROI
LWTH
EDGE
4-9