CP43维护手册.pdf.pdf - 第159页
19 – 1 V ersion 7.0 Chapter 19 V ideo Signal Gain and Offset 19. Video Signal Gain and Offset Gain and offset ar e parameters to which the vision system r efers when converting a camera’s analog signal to a digital signa…
Chapter 18 Camera Proper Data Backup Procedure
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CP IV-3 Maintenance
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Version 7.0
Chapter 19 Video Signal Gain and Offset
19.Video Signal Gain and Offset
Gain and offset are parameters to which the vision system refers when
converting a camera’s analog signal to a digital signal for processing. Gain and
offset must be properly set for the mark and parts cameras to provide usable
images. These settings are made at the factory before the machine is shipped,
and normally the user has no need to change them. However, if image contrast
decreases as the result of damage to a camera, or if the marks on a set of boards
do not contrast well with the background, the user may adjust the gain and
offset as necessary.
19.1Gain
Gain determines the contrast of an image. The smaller the number, the
higher the gain. If the gain is set too high, background noise may increase
to an unacceptable level.
Gain can be set from 0 to 255.
19.2Offset
Offset determines the brightness of an image. The value defines the point
below which signals are ignored. Since noise levels rise as gain increases,
offset must be raised accordingly to exclude noise from the image.
Offset can be set from 0 to 255.
Note: The offset value can be changed if there is difficulty in reading the fiducial
mark or the part, but chances of this type of problem occurring are very
rare. Normally the user should not change the offset value.
CP IV-3 Maintenance
Chapter 19 Video Signal Gain and Offset
19.3Setting Gain and Offset
(1) Press [SET], [MANUAL] and [VISION]. An ID code must be entered
to access vision commands.
(2) Press [BRIGHT].
(3) Press [MARK CAMERA] to set gain and offset for the mark camera.
Press [NARROW VIEW] to set gain and offset for the narrow view
parts camera.
Press [WIDE VIEW] to set gain and offset for the wide view parts
camera.
When any of the above function keys is pressed, the monitor displays
a realtime image from the selected camera. The image changes
dynamically as gain and offset are adjusted.
(4) Press [SELECT] to choose between gain and offset adjustment.
Note: Refer to Part 3 of the CP IV-3 Operation Manual for details of the gain
and offset setting commands.
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