ILLUMINATION INSTRUMENT WITH DOPPLER SENSOR

摘要

PROBLEM TO BE SOLVED: To provide an illumination instrument with a Doppler sensor capable of suppressing an erroneous determination caused by a noise component generated by a lighting circuit.

SOLUTION: A lighting circuit for lighting a light source mixes a noise component of a fixed cycle into a Doppler signal output by a Doppler sensor. A timing circuit is provided which generates an intermittent signal that is a rectangular wave of which the cycle is matched with that of the noise component and of which on-duty is 20%. A determination circuit for determining the presence/absence of a human body within a detection range samples a signal level Vdp of the Doppler signal only while a signal level Vi of the intermittent signal is H during a period in which the light source is lighted by the lighting circuit, and makes the determination on the basis of a sampling result Vsp. In comparison with a case where the intermittent signal is not used, an erroneous determination caused by the noise component can be suppressed.

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