Method and apparatus for electronically monitoring a field of view

Claim 3

The method of claim 1 including the step of indicating an alarm condition responsively to said comparison.

Claim 4

The method of claim 1 wherein the step of counting includes: generating a pulse each time the amplitude of said electronic signatures exceeds said threshold; counting the number of pulses generated for each oF said electronic signatures; and, storing the number counted for one of said electronic signatures.

Claim 5

The method of claim 3 wherein the step of comparing comprises determining the difference between said stored number and the number counted in another of said electronic signatures.

Claim 6

The method of claim 4 including the step of indicating an alarm condition when said difference exceeds a predetermined number.

Claim 9

The method of claim 6 including the step of indicating an alarm condition responsively to said comparison.

Claim 10

Apparatus for monitoring a predetermined field of view comprising: means for generating successive electronic signatures of said field of view; means for counting the number of times that the amplitude of each of said electronic signatures exceeds a predetermined threshold; and, means for comparing the number counted in one of said electronic signatures with the number counted in another of said electronic signatures.

Claim 11

Apparatus for monitoring a predetermined field of view comprising: means for generating successive electronic signatures of said field of view; means for counting the number of times that the amplitude of each of said electronic signatures exceeds a predetermined threshold; and, means for comparing the number counted in one of said electronic signatures with the number counted in another of said electronic signatures.

Claim 12

The apparatus of claim 8 including means for indicating an alarm condition in response to an inequality between said compared numbers.

Claim 13

The apparatus of claim 8 wherein said electronic signatures each comprise a composite video signal having an amplitude related to the light reflected from an optical image within said field of view and having scan synchronization signals superimposed thereon, and wherein said counting means comprises: means for isolating at least a portion of said scan synchronization signals from said composite video signal; means for generating a pulse each time the amplitude of said video signals exceeds a predetermined threshold; means for counting the number of said generated pulses for said video signals; and, means responsive to said counting means and said isolating means for storing said counted number for one of said video signals.

Claim 14

The apparatus of claim 10 wherein said comparing means comprises: means for generating a digital signal representative of the numerical difference between said stored number and the number of pulses counted for another of said electronic signals; and, means for generating an alarm signal when said digital signal exceeds a predetermined number.

Claim 15

The apparatus of claim 8 wherein said generating means comprises a television camera tube.

Claim 16

The apparatus of claim 12 wherein said counting means comprises: means for generating a pulse each time the amplitude of said electronic signatures exceeds said threshold; means for counting the number of pulses generated for each of said electronic signatures; and, means for storing the number of pulses counted for one of said electronic signatures.

Claim 17

The apparatus of claim 13 wherein said comparing means comprises means responsive to said counting means and said storing means for determining the difference between said stored number and the number of pulses counted for another of said electronic signatures.

Claim 18

The apparatus of claim 14 including means for generating an alarm signal when said difference exceeds a predetermined number.

Claim 19

In a surveillance system for monitoring unaUthorized intrusion into a predetermined area, said system comprising television camera means for generating successive electronic signatures of a field of view which includes said area, means for supplying said successive electronic signatures to a remote security station, visual monitor means at said security station for providing a visual reproduction of said area responsively to said successive electronic signatures and automatic monitor means at said security station for automatically detecting unauthorized intrusion into said area, the improvement wherein said automatic monitor means comprises: means responsive to each of said successive electronic signatures for generating an electrical pulse each time that the amplitude of said electronic signatures exceeds a predetermined threshold; means for counting the number of generated electricl pulses; means for storing the number of pulses counted in a first one of said successive electronic signatures; means for comparing the stored number in said first one of said successive electronic signatures with the number of pulses subsequently counted in a second one of said electronic signatures; means responsive to said comparing means for generating an alarm signal when a selected numerical difference between the numbers compared is exceeded.

Claim 20

In a surveillance system for monitoring unaUthorized intrusion into a predetermined area, said system comprising television camera means for generating successive electronic signatures of a field of view which includes said area, means for supplying said successive electronic signatures to a remote security station, visual monitor means at said security station for providing a visual reproduction of said area responsively to said successive electronic signatures and automatic monitor means at said security station for automatically detecting unauthorized intrusion into said area, the improvement wherein said automatic monitor means comprises: means responsive to each of said successive electronic signatures for generating an electrical pulse each time that the amplitude of said electronic signatures exceeds a predetermined threshold; means for counting the number of generated electricl pulses; means for storing the number of pulses counted in a first one of said successive electronic signatures; means for comparing the stored number in said first one of said successive electronic signatures with the number of pulses subsequently counted in a second one of said electronic signatures; means responsive to said comparing means for generating an alarm signal when a selected numerical difference between the numbers compared is exceeded.