2005-06-27
Page
5
2.4 CMOS
SENSOR
The Dica 220 uses a monochrome sensor IBIS5A-1300
from FillFactory. This sensor is specially designed for
industrial machine vision, because it has both a rolling and
a synchronous shutter. High dynamic range scenes can be
captured using the double or multiple slope functionality.
Depending on the mode of operation, the following main
features are available:
•
1280 x 1024 Pixels
•
10 bit 40 MHz sample ADC resolution
•
2/3” sensor
•
One region of interest (ROI)
•
Programmable ROI dimensions
•
Programmable exposure time
•
10, 20 or 40 MHz pixel clock
•
Full Frame rate:
FrameGrabber mode
: 4 frames per second (when a
100 Mbit/s Ethernet connection is used)
Embedded mode
: 27 frames per second
•
Optical dynamic range 64 dB in single slope,
up to 100 dB in multi slope.
•
Decimation factor 2 for higher frame rates of sub-
sampled images
Besides the quality of the CMOS sensor, the illumination
and the optical path determine the image quality and
corresponding measurement accuracy. When any of these
elements has a bad quality or performance, the resulting
image which will be used for processing will / can have
distortions.
The CMOS sensor quality can not be influenced by the
user. The quality of the illumination and the used optics on
the other hand is completely the responsibility for the user
of the Dica 220. Always use illumination and optical
elements of a good quality with respect to the required
accuracy.
One aspect related to the optical path to the CMOS sensor
is the cleanness of the sensor itself. During the production
of the Dica 220 special account is taken with respect to the
cleanness of the sensor. However when you remove the
sensor protection cap from the Dica 220 front end prior to
the mounting of a lens, the sensor can attract some dust or
dirt. This can affect the image captured with the Dica 220.
Therefore remove the sensor protection cap only in a clean
environment by holding the Dica 220 with the sensor facing
down. After removing the sensor protection cap inspect the
cleanness of the sensor and immediately attach the
required lens to the Dica 220.
When contamination is detected on the glass in front of the
sensor it can be removed by applying dry compressed air
to the sensor. When this doesn't clear the contamination
the dry compressed air can be combined with wiping the
glass with lens tissues. Because of the glass you don’t
have to be afraid of damaging the sensor.
Always keep the Dica 220 facing down when you have the
protection cap removed.
