To accurately discriminate between motion stop and leaving from a room.
In this human body detector having a human body sensor having an image pick-up device for image-picking up a bath room or the like with a prescribed time interval, a moving amount computing means for computing a human body moving amount as a difference between photoreception light quantities based on comparison between both images before and after the prescribed time interval, and a presence-of-moving determining means for determining the presence of moving in the human body by the moving amount computing means, an adjacent picture element difference computing means is provided to compute a difference between picture element data of a specified picture element out of one acquired image when the moving of the human body gets great, and of an adjacent picture element adjacent thereto, and the difference between the picture element data is squared, for example, to be added, so as to discriminate the operation stop from the leaving-off from the room.
IKEUCHI YASUHIDE
UEDA TAKAYUKI
