Vivotek IP Surveillance Overview page 21

Chap.2 Lens and Image Sensor Technology
ICR
An ICR (IR-cut Filter Removable) is a mechanical shutter design. It is placed between the lens and the image
sensor and is controlled by a motor or an electromagnet (Figure 2.16).
When the ICR is switched on, it will block infrared light and allow only visible light to pass through. When the ICR is
switched off, infrared light will be allowed and images will turn into black-and-white mode, which is more sensitive
to infrared light (Figure 2.17).
Wave Length (nm)
Day
Light Transmission
Wave Length (nm)
Night
Light Transmission
Wave Length (nm)
16
Figure 2.16 Placement of ICR
Ultraviolet Visible Light
invisible
100 380
100 380
100 380
Figure 2.17 Operation of ICR in daytime and nighttime
Infrared
invisible
770 1000
770 1000
770 1000