Precaution When Using The Cmos Image Sensor - Hamamatsu Photonics C11440-42U30 Instruction Manual

C11440-42U30/C11440-42U31 Instruction manual_Ver.1.2
10. PRECAUTION WHEN USING THE CMOS
IMAGE SENSOR
This camera uses the scientific CMOS image sensor. Careful attention must be paid to the
following points when using the CMOS image sensor:
(1) White spot
Subjecting the CMOS image sensor to extended exposures may cause failure in part of
the silicon wafer, resulting in white spots. Currently this phenomenon is not
preventable. If the CMOS image sensor is at a fixed temperature, recurrence of the
white spot increases proportionally with the exposure time, so this can be rectified with
dark subtraction*. Cosmic ray may generate white spot.
*
After acquiring an image using a certain exposure time is loaded, the CMOS image sensor is exposed to darkness for
the same amount of time, and another image is obtained. After this, the difference between the images is determined,
and the data for the dark portion of the original image is nullified.
(2) Folding distortion
A rough-edged flicker may be visible when imaging striped patterns, lines, and similar
subject matter.
(3) Over light
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Be careful not to input too strong light such as high-energy laser
•
into the CMOS image sensor because the CMOS image sensor
may be damaged by over light.