INTRUDER DETECTION APPARATUS

• US 3,610,822 A
• Filed: 03/17/1969
• Issued: 10/05/1971
• Est. Priority Date: 03/20/1968
• Status: Expired due to Term

• Current Assignee: Christopher Archibald Gordon Le May, Robert Justin Froggatt, William Ellis Ingham
• Original Assignee: Christopher Archibald Gordon Le May, Robert Justin Froggatt, William Ellis Ingham
• Inventors: Ingham, William Ellis, Froggatt, Robert Justin, Le May, Christopher Archibald Gordon
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Eckert, Jr., Richard K.
• Application Number:
  US04/807,886
• Time in Patent Office: 932 Days
• Field of Search: 178/6,6.8
• US Class Current: 348/155
• CPC Class Codes: G08B 13/19602 Image analysis to detect motion of the intruder, e.g. by frame subtraction
• CPC Class Codes: G08B 13/19606 Discriminating between target movement or movement in an area of interest and other non-signicative movements, e.g. target movements induced by camera shake or movements of pets, falling leaves, rotating fan
• CPC Class Codes: G08B 13/19645 Multiple cameras, each having view on one of a plurality of scenes, e.g. multiple cameras for multi-room surveillance or for tracking an object by view hand-over

Abstract

A pickup tube repetitively scans a region so as to produce video signals dependent on radiation received from the region, and operating means produce a plurality of second signals which are dependent on changes in radiation from one scan to another from respective portions of the region. Alarm means produce an alarm signal when any of the second signals exceeds a threshold individual to the respective portion. The shapes of each of the portions may be varied and the second signals may be weighted. A plurality of pickup tubes may be provided each arranged to survey a different region, the pickup tubes being sequentially monitored by the operating means. In another embodiment two pickup tubes are provided one having a longer lag than the other, and the video signals derived from the two tubes for the respective portions of the region compared to produce the second signals.

Claims

1. Apparatus for detecting movement in a region, comprising:

a. at least one pickup tube arranged to repetitively scan the region to produce video signals dependent on radiation received from said region, b. means for operating on said video signals for deriving a plurality of second signals which are dependent on changes from one scan to a later scan in the radiation from respective portions of said region, c. means for passing each second signal to a threshold circuit having a threshold individual to the respective portion, and d. means for producing an alarm signal when any of said second signals exceeds a respective threshold.

2. Apparatus according to claim 1 including a plurality of television pickup tubes each arranged to survey a different region, and means for sequentially monitoring said pickup tubes by said operating means.

3. Apparatus according to claim 1 wherein said operating means include means for distributing contributions to said video signals from separate portions to channels, respectively representing said portions of the region, means for accumulating contributions in each channel, and means for comparing the accumulated contributions in each channel derived during one scan with contributions accumulated during an earlier scan to produce thE respective second signal.

4. Apparatus according to claim 1 wherein said operating means include means for comparing contributions to said video signals from separate portions derived during different scans so as to produce difference signals, and means for accumulating the separate difference signals so as to produce said second signals.

5. Apparatus according to claim 1 including two pickup tubes, one having a longer lag than the other, and wherein said operating means includes means for comparing the video signals derived from the two tubes for the respective portions of the region to produce said second signals.

6. Apparatus according to claim 1 including means operative to response to the production of an alarm signal for causing the region surveyed to be displayed on a monitor.

7. Apparatus according to claim 4 including means for weighting said second signals.

8. Apparatus according to claim 7 including means for producing signals related to the rates of change with respect to time of said contributions to said video signals derived during different scans, means for summing said signals related to the rates of change to produce sum signals, and means for weighting each difference signals by means of the respective sum signal.