Method and circuit for interpolating encoder output
AssigneeMitutoyo Corporation
InventorsTetsuro Kiriyama, Ryuichi Koiso, Toshirou Yoshinaka
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Abstract
Two-phase sinusoidal signals QA, QB output from an encoder are interpolated by sample-and-hold (S/H) circuits and A/D conversion (ADC) circuits, and data D is output in accordance with a data request signal RQ from exterior. For this interpolation of encoder output, a direction discrimination up/down counter is arranged near a two-phase square-wave uniform pulse generating circuit, and the data D is latched and output using a signal which is obtained by delaying the data request signal RQ. This can reduce synchronization errors between the data request signal RQ from exterior and the interpolated data, with an improvement in dynamic precision.
Claims10
A method of interpolating an encoder output for interpolating two-phase sinusoidal signals output from an encoder through sample-and-hold and A/D conversion, and outputting data in accordance with a data request signal from exterior, the method comprising:
- arranging a direction discrimination up/down counter near a two-phase square-wave uniform pulse generating circuit;
- and
- latching and outputting data by using a signal obtained by delaying the data request signal.
A method of interpolating an encoder output for interpolating two-phase sinusoidal signals output from an encoder through sample-and-hold and A/D conversion, and outputting data in accordance with a data request signal from exterior, the method comprising:
- counting time from sampling of the A/D conversion to a data request;
- and
- interpolating data based on the counted time.
A method of interpolating an encoder output for interpolating two-phase sinusoidal signals output from an encoder through sample-and-hold and A/D conversion, and outputting data in accordance with a data request signal from exterior,
- the method comprising performing sampling of the A/D conversion in synchronization with the data request signal.
A circuit for interpolating an encoder output for interpolating two-phase sinusoidal signals output from an encoder through sample-and-hold and A/D conversion, and outputting data in accordance with a data request signal from exterior, the circuit comprising:
- a direction discrimination up/down counter arranged near a two-phase square-wave uniform pulse generating circuit;
- and
- a delay circuit for delaying the data request signal, wherein
- data is latched and output by using output of the delay circuit.
A circuit for interpolating an encoder output for interpolating two-phase sinusoidal signals output from an encoder through sample-and-hold and A/D conversion, and outputting data in accordance with a data request signal from exterior, the circuit comprising:
- a count circuit for counting time from sampling of the A/D conversion to a data request;
- and
- an interpolation and approximation circuit for interpolating data based on the counted time.
A circuit for interpolating an encoder output for interpolating two-phase sinusoidal signals output from an encoder through sample-and-hold and A/D conversion, and outputting data in accordance with a data request signal from exterior, wherein
- sampling of the A/D conversion is performed in synchronization with the data request signal.
Dependencies are inferred from the claim text.