| 摘要 |
PROBLEM TO BE SOLVED: To provide both short distance high speed communication and long distance low speed communication without increasing current consumption or complicating a circuit configuration. SOLUTION: This device is provided with a light emitting element 6 for outputting an optical signal, a modulating circuit 2 for IrDA for outputting a short distance high speed signal by IrDA, a modulating circuit 4 for a base band for outputting a long distance low speed signal through base band transmission, a drive circuit 3 for IrDA for driving the light emitting element 6 by forming driving currents corresponding to the short distance high speed signal outputted from the modulating circuit 2 for IrDA, a drive circuit 5 for a base band for driving the light emitting element 6 by forming driving currents corresponding to the long distance low speed signal outputted from the modulating circuit 4 for a base band, a photodetector 7 for receiving the optical signal and a demodulating circuit 10 for demodulating the optical signal by IrDA and the optical signal, through the base band transmission received by the photodetector 7. |
