Dalsa 1M28-SA, Руководство пользователя

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8 PRELIMINARY 1M28 and 1M75 User’s Manual
03-32-00525-03 DALSA
Sensor Cosmetics: Blemishes Types
The 1M28 and 1M75 one megapixel CMOS sensor has two different blemish types,
referred to as hot pixels (bright blemishes) and dark blemishes.
Hot Pixels
Hot pixels are pixels that generate excessive amounts of dark current relative to other
pixels. Some hot pixels will generate dark current at 10 to 20 times the rate of a normal
pixel. Hot pixels are isolated single pixel defects. They follow the general rule of thumb
for dark current where the dark current doubles every 7-8°C. They are more easily
recognizable when the camera is in dark conditions.
Figure 1: Typical Output at Dark, 1ms Exposure Time
Figure 1 depicts the number of pixels that generate larger amounts of dark current than
your average pixel—the average pixel level output is 7DN.
Figure 2: Typical Output at Dark, 10ms Exposure Time
Figure 2 depicts the number of pixels that generate larger amounts of dark current than
your average pixel—the average pixel level output is 8DN.