Security sensor having disturbance detecting capability
First Claim
1. A security sensor having a disturbance detecting capability, which comprises:
- a carrier body having an infrared sensor element;
an incident side enclosure mounted on the carrier body, said incident side enclosure comprising a lens that defines at least one detection area for the infrared sensor element or a cover that covers an incident surface area of the infrared sensor element;
a light projecting element for projecting a disturbance detecting beam;
a light receiving element for receiving at least a portion of the disturbance detecting beam;
first and second light guide members separate from each other with a space therebetween and operatively associated with the light projecting element and the light receiving element, respectively, said first and second light guide members being cooperative with each other to define an optical path along and adjacent an outer surface of the incident side enclosure or an outer surface of the carrier body adjacent the incident side enclosure so as to extend between the first and second light guide members;
a detecting circuit for detecting a presence or absence of an obstacle, applied to at least one of the first and second light guide members, based on an amount of light received by the light receiving element; and
surface irregularities formed on a light transmitting surface or a light reflecting surface of the first or second light guide members which surface is exposed traverse to the optical path.
1 Assignment
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Accused Products
Abstract
A security sensor 1 having a disturbance detecting capability capable of detecting the presence of an obstacle purposefully applied to the sensor 1 in an attempt to fool or tamper the sensor 1 includes a carrier body A having an infrared sensor element 4, an incident side enclosure 5 mounted on the carrier body A, a light projecting element 11 for projecting a disturbance detecting beam L1, a light receiving element 12 for receiving disturbance detecting beam L1, first and second light guide members 8, 9 operatively associated with the light projecting element 11 and the light receiving element 12, respectively, said first and second light guide members 8, 9 being cooperative with each other to define an optical path L along and adjacent an outer surface of the incident side enclosure 5 or an outer surface of the carrier body A adjacent the incident side enclosure 5, a detecting circuit 15 for detecting a presence or absence of an obstacle, applied to at least one of the first and second light guide members 8, 9, based on an amount of light received by the light receiving element 12. Surface irregularities are formed on a light transmitting surface 8c or 9c, or a light reflecting surface 8b or 9b of the light guide members 8 and 9.
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Citations
19 Claims
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1. A security sensor having a disturbance detecting capability, which comprises:
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a carrier body having an infrared sensor element;
an incident side enclosure mounted on the carrier body, said incident side enclosure comprising a lens that defines at least one detection area for the infrared sensor element or a cover that covers an incident surface area of the infrared sensor element;
a light projecting element for projecting a disturbance detecting beam;
a light receiving element for receiving at least a portion of the disturbance detecting beam;
first and second light guide members separate from each other with a space therebetween and operatively associated with the light projecting element and the light receiving element, respectively, said first and second light guide members being cooperative with each other to define an optical path along and adjacent an outer surface of the incident side enclosure or an outer surface of the carrier body adjacent the incident side enclosure so as to extend between the first and second light guide members;
a detecting circuit for detecting a presence or absence of an obstacle, applied to at least one of the first and second light guide members, based on an amount of light received by the light receiving element; and
surface irregularities formed on a light transmitting surface or a light reflecting surface of the first or second light guide members which surface is exposed traverse to the optical path. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A security sensor system comprising:
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a detector element for detecting infrared radiation representative of an intruder in a target area;
a cover member extending over the detector element and having an incident surface transmissive of the infrared radiation from the target area;
a source of a disturbance detecting beam directed above the cover member and on the other side of the cover member from the detector element; and
a disturbance detecting beam detector unit having a light guide member with an incident surface positioned above the cover member to receive a portion of the disturbance detecting beam that will vary depending upon a presence of any obstacle placed over the incident surface of the light guide member whereby the variance in reception of the amount of the disturbance detecting beam will be an indication of an obstacle, wherein the source of the disturbance detecting beam and the incident surface of the light guide member are spaced apart and above the cover member to provide an air gap there between. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A security sensor system comprising:
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a detector element for detecting infrared radiation representative of an intruder in a target area;
a cover member extending over the detector element and having an incident surface transmissive of the infrared radiation from the target area;
a source of a disturbance detecting beam having a transmission surface extending above the cover member and directing the disturbance detecting beam across the incident surface of the cover member; and
a disturbance detecting beam detector unit having an incident light guide surface extending above the cover member and spaced from the transmission surface to provide an air gap there between, the incident light guide surface will receive a portion of the disturbance detecting beam that will vary depending upon a presence of any obstacle placed over at least one of the transmission surface and the incident light guide surface, at least one of the transmission surface and the incident light guide surface will have surface irregularities whereby any obstacle that varies the transmission capability of the disturbance detecting beam will be detected. - View Dependent Claims (17, 18, 19)
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Specification