INFRARED RAY TRANSMITTER AND TRANSMISSION SYSTEM USING IT

PURPOSE:To obtain a simple central management or control system requiring no wiring, not giving adverse effect on the surrounding and immune to adverse effect from the surrounding. CONSTITUTION:The transmitter 1 is provided with a modulation circuit 3 converting a communication signal into a digital pulse signal, an infrared ray emitting element 4 sending an infrared ray digital pulse signal in response to the electric signal from the modulation circuit 3, and a converging lens 5 converging a radiation angle theta of an infrared ray sent from the light emitting element 4. The transmitter 1 forms a transmission system Sm for central management or central control together with a receiver 2 provided with a light receiving element 7 and a demodulation circuit 12 and a repeater interposed between the transmitter and the receiver. Since an infrared ray radiating from the light emitting element 4 is converged by the lens 5, the infrared ray reaches a long distance, does not give affect onto the surrounding and receives no effect from the surrounding. A simple transmission line being straight or meandered whose communication distance is limitless is built up with the repeater.