Simplified intruder detection module

• US 4,468,658 A
• Filed: 12/12/1980
• Issued: 08/28/1984
• Est. Priority Date: 09/10/1979
• Status: Expired due to Fees

• Current Assignee: John A. Rossin
• Original Assignee: John A. Rossin
• Inventors: Rossin, John A.
• Primary Examiner(s): Swann, III, Glen R.
• Application Number:
  US06/215,800
• Time in Patent Office: 1,355 Days
• Field of Search: 340/565, 340/567, 340/555, 340/556, 250/340, 250/342, 250/353, 338/18
• US Class Current: 340/567
• CPC Class Codes: G01V 8/20 using multiple transmitters or receivers
• CPC Class Codes: G08B 13/19 using infrared-radiation detection systems G08B13/194 takes precedence
• CPC Class Codes: Y10S 250/01 Passive intrusion detectors

Abstract

An Improved Intruder Detection Module is disclosed that incorporates a compact, unique optical system, a detector array, and an electronic system of a combined size and configuration that permits the Module to be shaped to approximate a normal household wall outlet box and its associated face panel. The optical system incorporates removable facet reflectors enabling the system to monitor any of a variety of different fields of view. The detector array includes pyroelectric elements mounted in an adjacent facing relationship to cause radiation passing through one element to immediately pass through the adjacent element, thereby causing intense white light to which the detector elements are not particularly responsive to generate substantially the same electrical signal in both elements. The electronic system may include a unique self-checking feature to regularly insure that the system is properly functioning, thereby avoiding nonresponse to an intruder. The electronic system also may dynamically adjusts its effective sensitivity to insure proper response of the system to low level inputs.

Claims

1. An intruder detection module having:

sensor means for producing an electric signal in response to non-visible radiation emitted by an intruder, the sensor means including at least one sensor pair having sensors substantially opaque to said non-visible radiation but substantially transparent to visible radiation;

optical means including a primary reflector for directing visible and non-visible radiation from a plurality of zones, both the visible and non-visible radiation from one zone being directed onto one sensor of the sensor pair, the visible and non-visible radiation from the second zone being directed onto the second sensor of the sensor pair;

means to direct radiation passing through one sensor to the other sensor of the pair, and

electronic means responsive to the electric signal output of the sensors to produce an alarm signal if one then the other sensor produces an output but to inhibit the alarm signal if both sensors produce an output at substantially the same time, whereby the system discriminates between radiation flashes simultaneously striking both sensors and movement of a non-visible radiation source across the zones defined by the optical means.

2. An intruder detection module as set forth in claim 1 in which the optical means includes a plurality of reflectors, and facet reflectors to direct radiation from other zones onto the primary reflector and hence to the sensor pair.

3. An intruder detection module as set forth in claim 2 in which the facet reflectors are removably mounted in the optical means.

4. An intruder detection module as set forth in claim 1 in which the means to direct radiation passing through one sensor to the other sensor of the pair mounts the sensors of the pair in an adjacent, facing relationship to permit radiation passing through one sensor to immediately strike the other sensor.

5. An intruder detection module as set forth in claim 4 in which the sensor pairs are mounted in frames received between two secondary reflectors, the secondary reflectors directing both visible and non-visible radiation onto the sensors.

6. An intruder detection module as set forth in claim 5 in which the sensor pair and associated frames and secondary reflectors are attached as a unit to a printed circuit board bearing the electronic means.

7. An intruder detection module having sensor means producing an electrical signal and responsive to an intruder, the sensor means including at least a pair of sensor elements viewing adjacent fields and responsive to the passage of an intruder between those fields to cause one sensor then the other sensor of the pair to product an electrical signal;

electrical means connected to the sensor means and responsive to the electrical signals produced by the pair of sensor elements to generate an alarm signal, the electronic means having two channel means, each channel means being connected to a corresponding one of the sensor elements and responsive to the electrical signals of that element to produce a first output signal;

alarm actuation means electrically responsive to the first output signals of the two channel means to generate an alarm signal;

inhibition means responsive to the substantially simultaneous generation of first output signals to inhibit the generation of an alarm signal;

timing means to delay the generation of an alarm signal sufficiently to permit the inhibition means to respond to the substantially simultaneous generation of first output signals by the channel means, thereby to prevent the generation of an alarm signal upon the occurrence of such a substantially simultaneous response of the two channel means; and

signal means responsive to the first output signals to produce a signal effectively increasing the sensivity of at least one channel means, whereby the sensivity of the electronic means to low level inputs to the sensor is increased to ensure that such low level signals will be detected.

8. An intruder detection module as set forth in claim 7 in which the signal means simultaneously effectively increases the sensivity of all channel means.

9. An intruder detection module as set forth in claim 7 in which the timing means and the inhibition means together define the sequence of first output signals required to permit the alarm actuation means to generate an alarm signal, the sequence being greater than a first interval required by the timing means but less than a second interval required by said inhibition means.

10. An intruder detection module as set forth in claim 7 including test circuit means responsive to at least one of said first output signals to cause the alarm actuation means to generate an alarm signal if either of the channel means or the inhibition means is not operating properly.

11. An intruder detection module as set forth in claim 10 in which the test circuit means produces an output signal which is applied to cause both sensor elements to simultaneously generate electrical signals, and control means responsive to the output of the inhibition means to prevent the alarm actuation means from generating an alarm signal, whereby if both the channel means and the inhibition means are operating properly, generation of the alarm signal as a result of the test circuit output signal is prevented.

12. An intruder detection module as set forth in claim 11 including time delay means to delay operation of the test circuit means until after of the expiration of predetermined interval sufficient to permit the alarm actuation means to generate an alarm signal if the module is functioning properly.

13. An intruder detection module as set forth in claim 12 including timing means to delay generation of the alarm signal sufficiently to permit the inhibition means to respond to the simultaneous generation of first output signals, thereby to prevent generation of an alarm condition upon the occurrence of such a simultaneous generation of output signals.

14. An intruder detection module as set forth in claim 13 in which the inhibition means is responsive to the substantially simultaneous generation of first output signals to inhibit generation of the alarm signal if the sequence of first output signals is less than a first interval.

15. An intruder detection module as set forth in claim 14 including signal means responsive to the first output signals to produce a signal simultaneously increasing the sensivity of the channel means, whereby the sensitivity of the electronic means to low level simultaneous inputs to the sensors is increased to ensure that such low level signals will be detected.

16. An intruder detection module as set forth in claim 15 in which the sensor means responds to non-visible radiation emitted by an intruder, the sensor elements being substantially opaque to said non-visible radiation but substantially transparent to visible radiation, the intruder detection module further including;

optical means including a primary reflector for directing visible and non-visible radiation from a plurality of zones, the visible and non-visible radiation from one zone being directed onto one sensor element, the visible and non-visible radiation from the second zone being directed on to a second sensor element; and

means to direct radiation passing through one sensor to a second sensor element.

17. An intruder detection module as set forth in claim 16 in which the optical means includes a plurality of reflectors, and facet reflectors to direct radiation from other zones onto the primary reflector hence to the sensor elements, the facet reflectors being removably mounted in the optical means.

18. An intruder detection Module as set forth in claim 7 in which inhibition means are included in each channel means, each inhibition means preventing response of the alarm actuation means to the other channel means for a period determined by the inhibition means.

19. An intruder detection Module as set forth in claim 18 in which each inhibition means compares a signal produced by its associated channel means with a reference signal and only prevents response of the alarm actuation means if the channel signal exceeds the reference signal.

20. A detector for an intruder detection system as set forth in claim 18, including optical filter means between the sensor elements to inhibit passage of long wavelength infrared radiation from one element to the other.

21. A detector for an intruder detection system having optical means defining at least two discrete fields of view and directing visible and infrared radiation from these fields of view to adjacent locations, and having electronic means responsive to signals to produce an alarm output, the detector including:

at least a pair of discrete sensor elements responsive to at least infrared radiation to produce an electrical signal;

means mounting the sensor elements in an adjacent, facing relationship; and

at least one reflector at said adjacent locations to direct radiation from the fields of view onto the outer face of the sensor elements, one field being directed onto the outer face of one element while the other field is directed onto the outer face of the other element, whereby white light and short wavelength infrared radiation passing through one sensor may pass directly through the adjacent sensor.