| 摘要 |
A reader having a high-resolution mode and a high-speed mode is disclosed. The reader comprises a CCD sensor, a buffer, a first AD convertor, a second AD convertor, a data selector and a control circuit. The input of the buffer is connected to the CCD sensor through a capacitor and a 5 V power source through an analog switch, and an output of the buffer is connected to the first AD converter for the high-resolution mode and the second AD converter for the high-speed mode in parallel. The data selector for selecting an output from the first AD convertor or the second AD convertor and sending it out to the control circuit is connected to the outputs of the first AD convertor and the second AD convertor.
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