| 摘要 |
PROBLEM TO BE SOLVED: To provide a sensor unit which efficiently eliminates erroneous sensing of a human sensor due to noise.SOLUTION: A price indicator 12 (a sensor unit) includes a human sensor 24 which senses movement of an object and outputs the movement by converting it to voltage. The price indicator 12 (the sensor unit) further includes: change value calculation means which repeatedly calculates a plurality of change values in parallel that are obtained by averaging an output voltage of the human sensor by a plurality of short measuring times of different lengths; a stationary value calculation means which repeatedly calculates a stationary value obtained by averaging the output voltage of the human sensor by a prescribed long measuring time which is sufficiently longer than the short measuring time; and determination means which determines that a human is sensed, on the basis of the fact that a total difference between each change value at the point when the change value calculation means calculated and the latest stationary value calculated by the stationary value calculation means is equal to or more than a prescribed human existing threshold value. |
