| 摘要 |
PROBLEM TO BE SOLVED: To improve precision of waveform display using the whole display screen by interpolation processing, in a waveform display device having more number of display pixels than resolution of an A/D converter. SOLUTION: This device is equipped with an offset circuit 18 for superimposing an offset voltage equivalent to a half of the resolution of the A/D converter 12 on an input signal, a switching circuit 20 for switching the superimposed state to/from the non-superimposed state of the offset voltage at each cycle, a duplication arithmetic circuit 14 for duplicating a digital value acquired from the A/D converter 12, an interpolation processing circuit 15 for performing interpolation processing of the digital value from the duplication arithmetic circuit 14, and a waveform memory 16 for memorizing the time-series digital value after interpolation processing as waveform data corresponding to the pixel position in the vertical direction to the time base direction of the display screen. The interpolation processing circuit 15 performs processing for correlating the digital value as it is with the pixel position in the vertical direction to the time base direction in a cycle wherein the offset voltage is not superimposed, and for correlating the digital value with the position shifted as much as one pixel in a cycle wherein the offset voltage is superimposed.
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