PROBLEM TO BE SOLVED: To make it possible to transmit a control signal even at the existence of an obstruction and to prevent the generation of radio wave faults in medical equipments because of no use of electromagnetic waves by providing a master equipment with a hear infrared ray receiving part for receiving a control signal consisting of near infrared rays from a slave equipment. SOLUTION: When a person enters a room, infrared rays hν radiated from a human body H are inputted to a pyrosensor 2 in the slave equipment 1a. The slave equipment 1a detecting the human body H radiates a control signal consisting of near infrared rays hν ' to the master equipment 1b and the near infrared rays hν' are made incident upon the master equipment 1b directly or by reflecting on a wall surface or a ceiling surface. The master equipment 1b receiving the control signal consisting of the near infrared rays hν' continuously lights up an electric lamp 19 during a period from the entrance of the person H into the room up to leaving. When the slave equipment 1a of the infrared human body detector 1 is set up on a proper place and the master equipment 1b is connected to a power supply for the lamp 19, a user can automatically turn on/off the lamp 19 only by entering the room without depressing a switch.
展开▼
