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Abstract

A motion detector assembly for a decorative lighting fixture that conceals the presence of the motion detector in a decorative element integrated into the design of the lighting fixture and that uses only mirrored optics instead of Fresnel lenses. The motion detector assembly includes a housing having a decorative external appearance harmonious with the style of the lighting fixture and forming an integral part of the lighting fixture. Included within the housing are a mirror assembly and PIR sensor. The mirror assembly includes a number of mirror faces that define a number of monitored zones in the field of view. Each respective mirror face defines an optical path in which radiation admitted through an aperture in the housing from an associated zone is directed to the sensor solely by the respective mirror face without the need for secondary mirrors or auxiliary lenses to complete the optical path. The mirror assembly can provide for two or more vertical levels of view and can provide for a wide angular field of view at one or more of the vertical levels of view. The mirror faces are arranged in tiers, and at least one tier is formed with distal extremities extending forward and looking to the sides so that a ray path emanating from a zone at the lateral reaches the field of view passes beneath a first distal extremity and reflects off the mirror face at the other distal extremity to the sensor. With this disposition of mirror faces at the distal extremities the tier is able to define a field of view having an angular width of at least 160 degrees and, depending on the length and shape of the tier and angular configuration of the distal extremities, extending at least up to 220 degrees. An aperture cover transmissive to infra-red radiation conforms to the shape of the housing around the aperture but otherwise plays no optical role in the operation of the motion detector, thereby giving the lighting fixture designer more aesthetic freedom in designing the motion detector housing.

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First Claim