| 摘要 |
A key matrix scanning apparatus is provided. The key matrix comprises a plurality of switches which are arranged at intersections of a plurality of input signal lines and a plurality of output signal lines. The scanning apparatus repeatedly and quickly discharges or charges the plurality of input signal lines at appropriate times within a one complete scanning cycle to establish a reference potential on these lines in preparation for readings of switch states. Therefore, the scanning apparatus can provide a high-speed scanning of switches with high reliability. A good number of switches can be coupled to be read by a single unit of key scanner without a substantial delay in the detection of the switch operation.
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