PIR motion sensor

• US 20050236572A1
• Filed: 05/20/2005
• Published: 10/27/2005
• Est. Priority Date: 03/14/2003
• Status: Active Grant

• Current Assignee: Suren Systems, Ltd.
• Original Assignee: Suren Systems, Ltd.
• Inventors: Micko, Eric Scott
• Granted Patent: US 7,755,052 B2
• Time in Patent Office: Days
• US Class Current: 250/342
• CPC Class Codes: G01V 8/10 Detecting, e.g. by using light barriers by reflection from the object G01S17/00
• CPC Class Codes: G08B 13/19 using infrared-radiation detection systems G08B13/194 takes precedence
• CPC Class Codes: G08B 13/191 using pyroelectric sensor means

Abstract

A passive infrared sensor has two detection members established by respective detectors and optical elements, with alternating spatial volumes being monitored by each detection member. No dead space need exist between volumes. The detection members are configured such that a moving object causes the members to output different frequencies, whereas a non-moving stimulus produces the same frequency from both detection members.

Claims

1. A PIR motion sensor comprising:

at least first and second infrared detection members, each detection member including at least one optical element and at least one detector with at least positive and negative detector elements, wherein;

the optical elements cooperate to establish four or more monitored spatial volumes substantially without any unmonitored vertical dead space between any two adjacent volumes established by the optical elements, the first detection member monitoring first volumes and the second detection member monitoring second volumes, the first and second volumes alternating in sequence; and

further wherein

a moving object causes the detector of the first detection member to output a signal having a frequency that is different from an output of the detector of the second detection member, and a non-moving stimulus causes both detectors to output the same frequency.

2. The sensor of claim 1, wherein at least one detector element of the first detection member has a different size than at least one detector element of the second detection member.

3. The sensor of claim 1, wherein a spacing between adjacent detector elements of the first detection member is different from a spacing between adjacent detector elements of the second detection member.

4. The sensor of claim 2, wherein a spacing between adjacent detector elements of the first detection member is different from a spacing between adjacent detector elements of the second detection member.

5. The sensor of claim 1, wherein the focal length of the optical element of the first detection member is different from the focal length of the optical element of the second detection member.

6. The sensor of claim 1, wherein a number of lens elements of the optical element of the first detection member is different from a number of lens elements of the optical element of the second detection member.

7. A motion sensor having at least first and second detection members monitoring alternating volumes of space with substantially no unmonitored vertical space between any two monitored volumes, each detection member including at least one optical element and at least one detector with at least positive and negative detector elements, wherein a moving object causes the detection members to output different frequencies from each other and a non-moving stimulus causes both detection members to output the same frequency.

8. The sensor of claim 7, wherein at least one detector element of the first detection member has a different size than at least one detector element of the second detection member.

9. The sensor of claim 7, wherein a spacing between adjacent detector elements of the first detection member is different from a spacing between adjacent detector elements of the second detection member.

10. The sensor of claim 8, wherein a spacing between adjacent detector elements of the first detection member is different from a spacing between adjacent detector elements of the second detection member.

11. The sensor of claim 7, wherein the focal length of the optical element of the first detection member is different from the focal length of the optical element of the second detection member.

12. The sensor of claim 7, wherein a number of lens elements of the optical element of the first detection member is different from a number of lens elements of the optical element of the second detection member.

13. A motion sensor having at least first and second detection members monitoring alternating volumes of space, each detection member including at least one optical element and at least one detector with at least positive and negative detector elements, wherein a moving object causes the detection members to output different frequencies from each other and a non-moving stimulus causes both detection members to output the same frequency.

14. The sensor of claim 13, wherein substantially no unmonitored vertical space exists between any two monitored volumes.

15. The sensor of claim 14, wherein at least one detector element of the first detection member has a different size than at least one detector element of the second detection member.

16. The sensor of claim 14, wherein a spacing between adjacent detector elements of the first detection member is different from a spacing between adjacent detector elements of the second detection member.

17. The sensor of claim 15, wherein a spacing between adjacent detector elements of the first detection member is different from a spacing between adjacent detector elements of the second detection member.

18. The sensor of claim 14, wherein the focal length of the optical element of the first detection member is different from the focal length of the optical element of the second detection member.

19. The sensor of claim 14, wherein a number of lens elements of the optical element of the first detection member is different from a number of lens elements of the optical element of the second detection member.

20. A motion sensor having at least first and second detection members monitoring alternating volumes of space with substantially no unmonitored vertical space between any two monitored volumes, each detection member including at least one optical element and at least one PIR detector with at least positive and negative detector elements.