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US 9,438,147 B2Granted
Position detecting apparatus and driving system
AssigneeKabushiki Kaisha Toshiba
InventorsHiroshi Ariga, Masahiro Inoue
Life of this patent
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Abstract
The position detecting apparatus includes a comparing part that compares the value of the digital signal output from the AD converter and a reference value that is based on a preset reference amplitude at the timings and outputs a control signal responsive to a result of the comparison. The position detecting apparatus includes an amplitude controlling part that controls amplification factors of the first amplifier and the second amplifier in such a manner that the value of the digital signal output from the AD converter comes closer to the reference value in response to the control signal output from the comparing part.
Claims20
A position detecting apparatus comprises:
- a sensor that outputs two position detection signals with different phases that vary with a same amplitude and a same period in response to a relative movement with respect to a scale;
- a first amplifier that outputs a first amplified signal obtained by amplifying an amplitude of a first position detection signal with a first phase of the position detection signals and a first inverted signal obtained by inverting the first amplified signal;
- a second amplifier that outputs a second amplified signal obtained by amplifying an amplitude of a second position detection signal with a second phase of the position detection signals and a second inverted signal obtained by inverting the second amplified signal;
- a first comparator that compares the first amplified signal and the second amplified signal and outputs a first comparison signal responsive to a result of the comparison;
- a second comparator that compares the first amplified signal and the second inverted signal and outputs a second comparison signal responsive to a result of the comparison;
- a phase angle measuring part that measures phase angles of the position detection signals with respect to a reference position, outputs a selection signal that prescribes which one of the first amplified signal, the second amplified signal, the first inverted signal and the second inverted signal should be selected, and outputs a timing signal that prescribes timings at which two of the first amplified signal, the second amplified signal, the first inverted signal and the second inverted signal intersect with each other;
- an AD converter that receives the first amplified signal, the second amplified signal, the first inverted signal and the second inverted signal, continuously reads a value of a signal selected according to the selection signal from among the first amplified signal, the second amplified signal, the first inverted signal and the second inverted signal, and outputs a digital signal responsive to the read value;
- a comparing part that compares the value of the digital signal output from the AD converter and a reference value that is based on a preset reference amplitude at the timings and outputs a control signal responsive to a result of the comparison;
- and
- an amplitude controlling part that controls amplification factors of the first amplifier and the second amplifier in such a manner that the value of the digital signal output from the AD converter comes closer to the reference value in response to the control signal output from the comparing part.
7 more elements
A driving system, comprising:
- a movable body;
- a driving motor that moves the movable body;
- a driver that drives the driving motor;
- a position detecting apparatus that outputs a signal responsive to a position of the movable body;
- a position measuring apparatus that obtains the position of the movable body based on the signal output from the position detecting apparatus;
- and
- a position controlling apparatus that controls the driver based on the position obtained by the position measuring apparatus,
- wherein the position detecting apparatus comprises:
- a scale;
- a sensor that outputs two position detection signals with different phases that vary with a same amplitude and a same period in response to a relative movement with respect to the scale;
- a first amplifier that outputs a first amplified signal obtained by amplifying an amplitude of a first position detection signal with a first phase of the position detection signals and a first inverted signal obtained by inverting the first amplified signal;
- a second amplifier that outputs a second amplified signal obtained by amplifying an amplitude of a second position detection signal with a second phase of the position detection signals and a second inverted signal obtained by inverting the second amplified signal;
- a first comparator that compares the first amplified signal and the second amplified signal and outputs a first comparison signal responsive to a result of the comparison;
- a second comparator that compares the first amplified signal and the second inverted signal and outputs a second comparison signal responsive to a result of the comparison;
- a phase angle measuring part that measures phase angles of the position detection signals with respect to a reference position, outputs a selection signal that prescribes which one of the first amplified signal, the second amplified signal, the first inverted signal and the second inverted signal should be selected, and outputs a timing signal that prescribes timings at which two of the first amplified signal, the second amplified signal, the first inverted signal and the second inverted signal intersect with each other;
- an AD converter that receives the first amplified signal, the second amplified signal, the first inverted signal and the second inverted signal, continuously reads a value of a signal selected according to the selection signal from among the first amplified signal, the second amplified signal, the first inverted signal and the second inverted signal, and outputs a digital signal responsive to the read value;
- a comparing part that compares the value of the digital signal output from the AD converter and a reference value that is based on a preset reference amplitude at the timings and outputs a control signal responsive to a result of the comparison;
- and
- an amplitude controlling part that controls amplification factors of the first amplifier and the second amplifier in such a manner that the value of the digital signal output from the AD converter comes closer to the reference value in response to the control signal output from the comparing part.
16 more elements
Dependencies are inferred from the claim text.