| 摘要 |
PURPOSE:To preclude data errors and malfunction due to an external noise and to improve operativity by transmitting data forth and back optically between portable information equipment and terminal equipment. CONSTITUTION:Data outputted by the CPU 14 of the portable information equipment 11 is converted by a light emitting circuit 15 into the turn-on or turn-off signal of a light emitting element 15d and then converted into a binary signal of 1 and 0 again by a light receiving element 16 in a printer cable 12, a current limiting circuit 17, and a waveform shaping circuit 18. When a printer 13 sends data to the portable information equipment 11, exactly the same operation is performed. Consequently, the operation becomes easier and clearer than by an attaching and detaching method for a connector, etc, and there is almost no influence of the external noise because of optical coupling, so that defects in contacting due to repetitive attachment and detachment are eliminated completely. |
