| 摘要 |
PROBLEM TO BE SOLVED: To obtain a cover whose transmittance to infrared rays is superior without spoiling the designing property of a structure body by forming a plurality of holes, for infrared transmission, whose diameter is at a specific value or lower on the optical axis of a sensing beam. SOLUTION: An infrared sensor 2 is covered with a cover 1. Thereby, the disharmony of a design with a structure body due to the exposure of the infrared sensor 2 is prevented. Since a beam spot 11 which is composed of holes is formed on the optical axis of a sensing beam 23, the transmittance of infrared rays is enhanced, and a human body in a desired sensing range can be detected surely. In addition, since the diameter of every hole is set at 0.4 mm or lower, the existence of every hole is not noticeable, and the designing property of a luminaire as a whole is not lowered. In addition, when the number of holes is set in such a way that an occupation rate is 40 to 70% with reference to the cross section of one sensing beam 23, the existence of the holes 12 is not noticeable while the transmittance of infrared rays in a range which does not spoil the performance of the sensor is being ensured, and the designing property of the luminaire as a whole is not lowered.
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