Infrared detectors having front and rear fields of view
First Claim
1. An infrared detector, comprising:
- a) a housing having a front portion and a rear portion;
b) an infrared sensor mounted within said housing and facing said front portion of said housing;
c) a forward looking optical means mounted in said front portion of said housing for directing infrared energy onto said infrared sensor from a source of infrared energy located forward said housing, said forward looking optical means facing in a first direction;
d) a rearward looking optical means mounted in said rear portion of said housing for permitting infrared energy to enter said housing from a source of infrared energy located rearward said housing, said rearward looking optical means facing in a second direction which is substantially more than ninety degrees from said first direction; and
e) reflective means mounted inside said housing directly between said infrared sensor and said forward looking optical means for reflecting infrared energy entering said housing through said rearward looking optical means onto said infrared sensor.
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Accused Products
Abstract
A motion sensor having front and rear fields of view includes a housing containing an infrared sensor mounted on a surface which may be a circuit board containing associated electronics to form the motion detector which produces an output in response to the motion of a warm body passing through the sensor'"'"'s field of view. A front part of the housing is provided with a forward looking optical system, preferably a multifaceted Fresnel lens, and a rear part of the housing is provided with at least one rearward looking optical system. A reflector is provided directly between the sensor and the forward looking optical system for reflecting infrared light entering the rearward looking optical system onto the detector. According to one embodiment of the invention, the rearward looking optical system includes a pair of Fresnel lenses and the reflector is a flat mirror. In another embodiment of the invention, the rearward looking optical system includes a pin hole and the reflector is a reflective surface on the inside of the forward looking optical system. In yet another embodiment of the invention, the rearward looking optical system is a window without any lens and the reflector is a focusing mirror. According to a preferred embodiment of the invention, the rearward field of view is directed downward.
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Citations
27 Claims
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1. An infrared detector, comprising:
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a) a housing having a front portion and a rear portion; b) an infrared sensor mounted within said housing and facing said front portion of said housing; c) a forward looking optical means mounted in said front portion of said housing for directing infrared energy onto said infrared sensor from a source of infrared energy located forward said housing, said forward looking optical means facing in a first direction; d) a rearward looking optical means mounted in said rear portion of said housing for permitting infrared energy to enter said housing from a source of infrared energy located rearward said housing, said rearward looking optical means facing in a second direction which is substantially more than ninety degrees from said first direction; and e) reflective means mounted inside said housing directly between said infrared sensor and said forward looking optical means for reflecting infrared energy entering said housing through said rearward looking optical means onto said infrared sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification