| 摘要 |
PURPOSE: Provided is an image change detection circuit in a thermal image system which uses one frame memory to compare a current signal with a preexisting signal and cause alarm in excess so that it helps to find the presence of infiltrators. CONSTITUTION: The image change detection circuit in the thermal image system comprises the parts of: a frame memory signal(31) which stores a digital image signal by a frame unit; a latch(32) which temporarily stores frame for the digital image signal; a comparator(33) which compares the preexisting image signal in the frame memory with a current image signal in the latch to generate a certain signal if both frame signals are different each other; a counter(34) which starts counting from an initial value on every output signal in the comparator; and an alarm(35) which causes an alarm, when the counted result exceeds the set value.
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