EP0005352A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Radiation detection intruder alarm apparatus
Assignee: BA Security Systems Ltd
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Filing: 1979-04-27
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Granted: —
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Expires: 1999-04-27
Abstract
Abstract Radiation detection apparatus includes a first detector (6) for detecting radiation at a wavelength which is preferably in the infra-red region, and means for sensing the presence of an obturating element (11), which element acts to prevent operating of the first detector. The sensing means includes a transmitter (14) which transmits a signal at a second wavelength, and a second detector (15) responsive to and arranged to receive the signal in the presence of the obturating element, preferably by reflection of the signal from the element. An alarm (10) may be activated in response to detection of radiation or of the transmitted signal.
Inventors
- 👤 David William Crick
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 11:31
CPC Classifications
G; G08; G08B; G08B29/00; G08B29/02; G08B29/04; G08B29/046; G08B13/00; G08B13/18; G08B13/189; G08B13/19; G08B13/193
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
94 words
Radiation detection apparatus comprising first detecting means (6,7,8) for detecting radiation at a first wavelength, first indicating means (9,10) responsive to said first detecting means, characterised in that means for sensing the presence of an obturating element (ll) preventing the operation of said first detecting means are provided, said sending means comprising transmitting means (12,13,14) for transmitting a signal at a second wavelength, second detecting means (15,16) responsive to the signal at the second wavelength in the presence of the obturating element (11), and second indicating means (17,10) responsive to said second detecting means.
Claim 2
Dependent Claim
94 words
Radiation detection apparatus comprising first detecting means (6,7,8) for detecting radiation at a first wavelength, first indicating means (9,10) responsive to said first detecting means, characterised in that means for sensing the presence of an obturating element (ll) preventing the operation of said first detecting means are provided, said sending means comprising transmitting means (12,13,14) for transmitting a signal at a second wavelength, second detecting means (15,16) responsive to the signal at the second wavelength in the presence of the obturating element (11), and second indicating means (17,10) responsive to said second detecting means.
Claim 3
Dependent Claim
22 words
Apparatus according to claim 1 wherein said second detecting means (15,16) is arranged to detect said signal reflected from the obturating element.
Claim 4
Dependent Claim
23 words
Apparatus according to claim 1 or 2, further including means (5) for emitting said transmitted signal as at least one substantially parallel beam.
Claim 5
Dependent Claim
26 words
Apparatus according to claim 3 wherein said emitting means is additionally arranged to focus said radiation at the first wavelength on to said first detecting means.
Claim 6
Dependent Claim
16 words
Apparatus according to claim 3 or 4, wherein said emitting means comprises a concave spherical mirror.
Claim 7
Dependent Claim
16 words
Apparatus according to claim 3 or 4, wherein said emitting means comprises a concave parabolic mirror.
Claim 8
Dependent Claim
26 words
Apparatus according to claim 3 or 4 wherein said emitting means comprises an array of mirrors arranged to emit a plurality of said substantially parallel beams.
Claim 9
Dependent Claim
42 words
Apparatus according to any one of the preceding claims wherein said transmitting means is arranged to transmit a signal at said second wavelength pulsed at a constant frequency, and said second detecting means is responsive to the signal pulsed at that frequency.
Claim 10
Dependent Claim
23 words
Apparatus according to any one of the preceding claims wherein said transmitting means is arranged to transmit radiation of substantially 0.9 microns wavelength.
Claim 11
Dependent Claim
23 words
Apparatus according to any one of the preceding claims and comprising alarm means (10) common to said first and said second indicating means.
References Cited (Backward Citations)
No citation records indexed.
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