US Patent 10395498 Fire detection apparatus utilizing a camera

A fire detection device is provided that has a camera that captures a reference image and a measured image. A processor compares intensity of the measured image to intensity of the reference image and uses this comparison to determine if an alarm is generated to indicate the presence of fire. The intensity of the measured image may be the total number of photons of the measured image, and the intensity of the reference image may be the total number of photons of the reference image. In other arrangements, the intensity may be measured between individual corresponding pixels of the reference and measured images.