| 摘要 |
<p>PURPOSE:To carry out a data communication in the form of a non-contact type without shielding disturbance light by arranging a means of indicating signal contents on the card surface and providing a receiving signal detecting circuit on a receiving light part. CONSTITUTION:When a data signal is transmitted from a reader/writer 11, lamp light, disturbance light as well as a modulation transmission signal enter a filter 19 that is incorporated into the surface and inside of a data management card 5 and the lamp lights and the disturbance lights are reduced in their gains. The signal passes through a photodetector 20, a DC amplifier 21, a capacitor 22, and an AC amplifier 23 to a band pass filter 24, which produces only the components of the modulating signal. This signal as digital signals to a processing part in the data management passes through a waveform shaping circuit to a processing unit of a data management card 5. Once the processing is complete, processed contents are indicated on a display 6 located on the surface of the card 5.</p> |
