Infrared intrusion detector

Claim 2

An infrared intrusion detector, comprising: a housing having an entrance window defining at least one reception zone of the detector; said entrance window being transparent to external infrared radiation; an infrared dual sensor for generating an output signal in response to externally impinging infrared radiation enclosed in said housing; an optical arrangement for directing external infrared radiation entering said housing through said entrance window from predetermined ones of said at least one reception zone to said infrared dual sensor; an evaluation circuit connected to said infrared dual sensor for generating a first alarm signal in response to a predetermined type of change in said output signal; an infrared radiation source for emitting checking infrared radiation and contained in said housing and constructed and arranged such that said checking infrared radiation irradiates said infrared dual sensor after traversing said entrance window; said evaluation circuit being constructed for additionally generating a second alarm signal in response to a predetermined degree of attenuation of said checking infrared radiation to indicate possible sabotage of the infrared intrusion detector; said infrared dual sensor comprising a first sensor element and a second sensor element arranged in proximate relationship to one another; said first sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a first predetermined manner; said second sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a second predetermined manner; and differential circuit means interconnecting said first sensor element and said second sensor element.

Claim 3

The infrared intrusion detector as defined in claim 1, wherein: said differential circuit having an output signal; and said evaluation circuit comprising means for generating a malfunction alarm signal when said output signal falls below a predetermined threshold value.

Claim 4

The infrared intrusion detector as defined in claim 1, further including: means for briefly activating said infrared radiation source at a predetermined radiation temperature for the temporal duration of a predetermined activation interval.

Claim 5

The infrared intrusion detector as defined in claim 3, wherein: the temporal duration of said predetermined activation interval is on the order of one second; and said predetermined radiation temperature being on the order of 100° C.

Claim 6

The infrared intrusion detector as defined in claim 1, wherein: said evaluation circuit generates said second alarm signal when sabotage of the infrared intrusion detector is carried out at said entrance window.

Claim 7

An infrared intrusion detector, comprising: a housing having an entrance window defining at least one reception zone of the detector; said entrance window being transparent to external infrared radiation; an infrared sensor for generating an output signal in response to externally impinging infrared radiation enclosed in said housing; an optical arrangement for directing external infrared radiation entering said housing through said entrance window from predetermined ones of said at least one reception zone to said sensor; an evaluation circuit connected to said sensor for generating a first alarm signal in response to a predetermined type of change in said output signal; an infrared radiation source for emitting checking infrared radiation and contained in said housing and constructed and arranged such that said checking infrared radiation irradiates said sensor after traversing said entrance window; said evaluation circuit being constructed for additionally generating a second alarm signal in response to a predetermined degree of attenuation of said checking infrared radiation; said infrared sensor comprising a first sensor element and a second sensor element; said first sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a first predetermined manner; said second sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a second predetermined manner; differential circuit means interconnecting said first sensor element and said second sensor element; said first and second sensor elements define a plane of symmetry lying therebetween; and said infrared radiation source lying outside of said plane of symmetry.

Claim 8

An infrared intrusion detector, comprising: a housing having an entrance window defining at least one reception zone of the detector; said entrance window being transparent to external infrared radiation; an infrared sensor for generating an output signal in response to externally impinging infrared radiation enclosed in said housing; an optical arrangement for directing external infrared radiation entering said housing through said entrance window from predetermined ones of said at least one reception zone to said sensor; an evaluation circuit connected to said sensor for generating a first alarm signal in response to a predetermined type of change in said output signal; an infrared radiation source for emitting checking infrared radiation and contained in said housing and constructed and arranged such that said checking infrared radiation irradiates said sensor after traversing said entrance window; said evaluation circuit being constructed for additionally generating a second alarm signal in response to a predetermined degree of attenuation of said checking infrared radiation; said infrared sensor comprising a first sensor element and a second sensor element; said first sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a first predetermined manner; said second sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a second predetermined manner; differential circuit means interconnecting said first sensor element and said second sensor element; said first and second sensor elements define a plane of symmetry lying therebetween; and said infrared radiation source lying outside of said plane of symmetry.

Claim 9

An infrared intrusion detector, comprising: a housing having an entrance window defining at least one reception zone of the detector; said entrance window being transparent to external infrared radiation; an infrared sensor for generating an output signal in response to externally impinging infrared radiation enclosed in said housing; an optical arrangement for directing external infrared radiation entering said housing through said entrance window from predetermined ones of said at least one reception zone to said sensor; an evaluation circuit connected to said sensor for generating a first alarm signal in response to a predetermined type of change in said output signal; an infrared radiation source for emitting checking infrared radiation and contained in said housing and constructed and arranged such that said checking infrared radiation irradiates said sensor after traversing said entrance window; said evaluation circuit being constructed for additionally generating a second alarm signal in response to a predetermined degree of attenuation of said checking infrared radiation; said infrared sensor comprising a first sensor element and a second sensor element; said first sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a first predetermined manner; said second sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a second predetermined manner; differential circuit means interconnecting said first sensor element and said second sensor element; said housing has a front side; said entrance window having an edge; and said infrared radiation source being arranged on said edge and on said front side.

Claim 10

An infrared intrusion detector, comprising: a housing having an entrance window defining at least one reception zone of the detector; said entrance window being transparent to external infrared radiation; an infrared sensor for generating an output signal in response to externally impinging infrared radiation enclosed in said housing; an optical arrangement for directing external infrared radiation entering said housing through said entrance window from predetermined ones of said at least one reception zone to said sensor; an evaluation circuit connected to said sensor for generating a first alarm signal in response to a predetermined type of change in said output signal; an infrared radiation source for emitting checking infrared radiation and contained in said housing and constructed and arranged such that said checking infrared radiation irradiates said sensor after traversing said entrance window; said evaluation circuit being constructed for additionally generating a second alarm signal in response to a predetermined degree of attenuation of said checking infrared radiation; said infrared sensor comprising a first sensor element and a second sensor element; said first sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a first predetermined manner; said second sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a second predetermined manner; differential circuit means interconnecting said first sensor element and said second sensor element; said housing has a front side; said entrance window having an edge; and said infrared radiation source being arranged on said edge and on said front side.

Claim 11

The infrared intrusion detector as defined in claim 7, wherein: said entrance window has a centerline; and said infrared radiation source being arranged off said centerline.

Claim 12

The infrared intrusion detector as defined in claim 7, wherein: said optical arrangement defines a reception direction; and said entrance window being set back in said reception direction in relation to said infrared radiation source.

Claim 13

The infrared intrusion detector as defined in claim 7, wherein: said entrance window is inclined relative to said front side of said housing.

Claim 14

An infrared intrusion detector, comprising: a housing having an entrance window defining at least one reception zone of the detector; said entrance window being transparent to external infrared radiation; an infrared sensor for generating an output signal in response to externally impinging infrared radiation enclosed in said housing; an optical arrangement for directing external infrared radiation entering said housing through said entrance window from predetermined ones of said at least one reception zone to said sensor; an evaluation circuit connected to said sensor for generating a first alarm signal in response to a predetermined type of change in said output signal; an infrared radiation source for emitting checking infrared radiation and contained in said housing and constructed and arranged such that said checking infrared radiation irradiates said sensor after traversing said entrance widow; said evaluation circuit being constructed for additionally generating a second alarm signal in response to a predetermined degree of attenuation of said checking infrared radiation; said infrared sensor comprising a first sensor element and a second sensor element; said first sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a first predetermined manner; said second sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a second predetermined manner; differential circuit means interconnecting said first sensor element and said second sensor element; a reflector mounted in said housing for deflecting said checking infrared radiation emitted by said infrared radiation source onto said sensor after having traversed said entrance window.

Claim 15

An infrared intrusion detector, comprising: a housing having an entrance window defining at least one reception zone of the detector; said entrance window being transparent to external infrared radiation; an infrared sensor for generating an output signal in response to externally impinging infrared radiation enclosed in said housing; an optical arrangement for directing external infrared radiation entering said housing through said entrance window from predetermined ones of said at least one reception zone to said sensor; an evaluation circuit connected to said sensor for generating a first alarm signal in response to a predetermined type of change in said output signal; an infrared radiation source for emitting checking infrared radiation and contained in said housing and constructed and arranged such that said checking infrared radiation irradiates said sensor after traversing said entrance widow; said evaluation circuit being constructed for additionally generating a second alarm signal in response to a predetermined degree of attenuation of said checking infrared radiation; said infrared sensor comprising a first sensor element and a second sensor element; said first sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a first predetermined manner; said second sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a second predetermined manner; differential circuit means interconnecting said first sensor element and said second sensor element; a reflector mounted in said housing for deflecting said checking infrared radiation emitted by said infrared radiation source onto said sensor after having traversed said entrance window.

Claim 16

The infrared intrusion detector as defined in claim 11, wherein: said reflector is included in said optical arrangement.

Claim 17

The infrared intrusion detector as defined in claim 11, wherein: said reflector comprises an optical element distinct from said optical arrangement.

Claim 18

The infrared intrusion detector as defined in claim 13, wherein: said first and second sensor elements conjointly define a plane of symmetry; and said reflector being arranged asymmetrically in relation to said plane of symmetry.

Claim 19

The infrared intrusion detector as defined in claim 14, wherein: said reflector is arranged to irradiate exclusively one sensor element of said first and second sensor elements.

Claim 20

An infrared intrusion detector, comprising: a housing having an entrance window defining at least one reception zone of the detector; said entrance window being transparent to external infrared radiation; an infrared sensor for generating an output signal in response to externally impinging infrared radiation enclosed in said housing; an optical arrangement for directing external infrared radiation entering said housing through said entrance window from predetermined ones of said at least one reception zone to said sensor; an evaluation circuit connected to said sensor for generating a first alarm signal in response to a predetermined type of change in said output signal; an infrared radiation source for emitting checking infrared radiation and contained in said housing and constructed and arranged such that said checking infrared radiation irradiates said sensor after traversing said entrance window; said evaluation circuit being constructed for additionally generating a second alarm signal in response to a predetermined degree of attenuation of said checking infrared radiation; said infrared sensor comprising a first sensor element and a second sensor element; said first sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a first predetermined manner; said second sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a second predetermined manner; differential circuit means interconnecting said first sensor element and said second sensor element;

Claim 21

An infrared intrusion detector, comprising: a housing having an entrance window defining at least one reception zone of the detector; said entrance window being transparent to external infrared radiation; an infrared sensor for generating an output signal in response to externally impinging infrared radiation enclosed in said housing; an optical arrangement for directing external infrared radiation entering said housing through said entrance window from predetermined ones of said at least one reception zone to said sensor; an evaluation circuit connected to said sensor for generating a first alarm signal in response to a predetermined type of change in said output signal; an infrared radiation source for emitting checking infrared radiation and contained in said housing and constructed and arranged such that said checking infrared radiation irradiates said sensor after traversing said entrance window; said evaluation circuit being constructed for additionally generating a second alarm signal in response to a predetermined degree of attenuation of said checking infrared radiation; said infrared sensor comprising a first sensor element and a second sensor element; said first sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a first predetermined manner; said second sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a second predetermined manner; differential circuit means interconnecting said first sensor element and said second sensor element;

Claim 22

obturation means for briefly transmitting said checking infrared radiation.

Claim 23

obturation means for briefly transmitting said checking infrared radiation.

Claim 24

The infrared intrusion detector as defined in claim 16, wherein: said obturation means comprises a mechanical shutter.

Claim 25

The infrared intrusion detector as defined in claim 16, wherein: said obturation means comprises an element of electrically controllable transmissivity.

Claim 26

An infrared intrusion detector, comprising: a housing having an entrance window defining at least one reception zone of the detector; said entrance window being transparent to external infrared radiation; an infrared sensor for generating an output signal in response to externally impinging infrared radiation enclosed in said housing; an optical arrangement for directing external infrared radiation entering said housing through said entrance window from predetermined ones of said at least one reception zone to said sensor; an evaluation circuit connected to said sensor for generating a first alarm signal in response to a predetermined type of change in said output signal; an infrared radiation source for emitting checking infrared radiation and contained in said housing and constructed and arranged such that said checking infrared radiation irradiates said sensor after traversing said entrance window; said evaluation circuit being constructed for additionally generating a second alarm signal in response to a predetermined degree of attenuation of said checking infrared radiation; said infrared sensor comprising a first sensor element and a second sensor element; said first sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a first predetermined manner; said second sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a second predetermined manner; differential circuit means interconnecting said first sensor element and said second sensor element; said infrared radiation source emitting said checking infrared radiation with a spectrum of wavelengths; and said spectrum of wavelengths having a maximum intensity of radiation between a wavelength of 5 μm and a wavelength of 15 μm.

Claim 27

An infrared intrusion detector, comprising: a housing having an entrance window defining at least one reception zone of the detector; said entrance window being transparent to external infrared radiation; an infrared sensor for generating an output signal in response to externally impinging infrared radiation enclosed in said housing; an optical arrangement for directing external infrared radiation entering said housing through said entrance window from predetermined ones of said at least one reception zone to said sensor; an evaluation circuit connected to said sensor for generating a first alarm signal in response to a predetermined type of change in said output signal; an infrared radiation source for emitting checking infrared radiation and contained in said housing and constructed and arranged such that said checking infrared radiation irradiates said sensor after traversing said entrance window; said evaluation circuit being constructed for additionally generating a second alarm signal in response to a predetermined degree of attenuation of said checking infrared radiation; said infrared sensor comprising a first sensor element and a second sensor element; said first sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a first predetermined manner; said second sensor element being irradiated with said checking infrared radiation by said infrared radiation source in a second predetermined manner; differential circuit means interconnecting said first sensor element and said second sensor element; said infrared radiation source emitting said checking infrared radiation with a spectrum of wavelengths; and said spectrum of wavelengths having a maximum intensity of radiation between a wavelength of 5 μm and a wavelength of 15 μm.