摘要 |
The digitization apparatus includes, as a main scale, a pulse delay circuit constituted by a plurality of delay units connected in series or in ring form, a latch/encoder, a circulation number counter, and a latch circuit, and includes, as a vernier, a reverse timing extraction circuit detecting a reverse timing at which any one of the delay units has reversed, and an interpolation circuit. The main scale digitizes a time interval between two successive measurement signals in a resolution equal to a delay time per one delay unit. The vernier digitizes a time difference between a measurement timing indicated by the measurement signal and the reverse timing in a resolution equal to 1/M (M being an integer not smaller than 2). The interpolation circuit includes two delay lines each constituted by a plurality of delay units connected in series or in ring form.
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