Patent ID: 6233006
Filing Date: 2001-05-15
Classification: G08B,H04N

Abstract:
An image change detecting machine comprising:a video camera for taking a photograph and outputting the video signal for it;a synchronous signal separating part for separating and outputting the video signal from the video camera into a vertical synchronous signal and a horizontal synchronous signal;a monitor for displaying the video signal from the video camera;a character generator for outputting letter signal the synchronousness of which matches with that of the video signal received from the video camera based on the synchronous signal applied from the synchronous signal separating part;an analog switches for overlapping the video signal from the video camera and the letter signal from the character generator and outputting it to the monitor, and detecting the change of the video signal at where the frequency of the video signal from the video camera and the frequency of the letter signal from the character generator match each other and outputting the detecting signal corresponding to this;a comparator for comparing the detecting signal from the analog switches with the standard signal and outputting the control signal corresponding to this;a main controlling part for determining the letter signal output from the character generator and controlling its location, and outputting the alarm signal in accordance with the control signal from the comparator;a buffer for stabilizing the control signal from the comparator and applying it to the main controlling part; andan alarm generating part for generating or cutting off alarm in accordance with the alarm signal from the main controlling part.