Video signal dropout detector

A method of detecting video signal dropout, the method comprising the steps of:

• receiving a video signal;
• isolating at least one component of the video signal, the at least one component being representative of the absence of the video signal itself;
• sensing the absence of the at least one component;
• generating the video signal for a predetermined time duration;
• generating an audio signal to indicate the end of the predetermined time duration;
• and
• terminating the step of sensing in response to the audio signal.

A video signal dropout detector comprising:

• a video signal source;
• isolation means, connected to the video signal source, for isolating at least one signal component from a video signal generated by the video signal source;
• sensing means, connected to the isolation means, for sensing an interruption in the at least one signal component;
• counting means for counting a number of dropouts occurring within a test period;
• and
• display means for displaying said number of dropouts;
• wherein an interruption in the at least one signal component corresponds to a dropout of the video signal generated by the video signal source.

A video signal dropout detector comprising:

• a video signal source;
• isolation means, connected to the video signal source, for isolating at least one signal component from a video signal generated by the video signal source;
• and
• sensing means, connected to the isolation means, for sensing an interruption in the at least one signal component;
• wherein an interruption in the at least one signal component corresponds to a dropout of the video signal generated by the video signal source, wherein the isolation means includes a comb filter, wherein the at least one signal component is isolated by passing the video signal through the comb filter, and wherein the at least one signal component includes a luminescence component of the video signal.

A video dropout detector mechanism comprising the following:

• separation means for separating luminescence and synchronization components from a video signal,
• restorer means, electrically connected to the separation means, for restoring the luminescence and synchronization components of the video signal;
• comparator means, electrically connected to the restorer means, for comparing an output of the restorer means to a reference value;
• logic circuit connected to the comparator means;
• and
• a computer operatively connected to the logic circuit;
• whereby the computer includes a memory which saves the output from the comparator means.

A video signal dropout detector comprising:

• a video tape player serving as a signal source by playback of a test tape;
• said test tape including audio signals indicative of a test start and a test stop signal, and a video signal comprising a green raster;
• isolation means, including a comb filter and a video sync separator, connected to the video signal source, for isolating a luminance signal component from a video signal generated by the video signal source;
• and
• sensing means, including a window comparator connected to the isolation means, for sensing an interruption in the at least one signal component by comparing said luminance signal with an upper threshold and a lower threshold;
• wherein if said luminance signal is outside said upper and lower thresholds, a dropout of the video signal generated by the video signal source is deemed to have occurred;
• counting means for counting a number of dropouts occurring between the occurrence of said start and stop signals within a test period;
• and
• display means for displaying said number of dropouts.