ROTARY ENCODER AND METHOD OF DETECTING ABNORMALITY OF ROTARY ENCODER
First Claim
1. A rotary encoder of an incremental type, comprising:
- a rotation detector that outputs a continuous wave signal of a first phase and a continuous wave signal of a second phase according to rotation of a rotating body, the continuous signal of the first phase and the continuous signal of the second phase having a phase difference from each other;
a signal output unit that generates a rectangular wave output signal of the first phase and a rectangular wave output signal of the second phase from the continuous wave signal of the first phase and the continuous wave signal of the second phase, respectively and outputs the rectangular wave output signals of the first phase and the second phase from the rotary encoder;
an internal signal generator that generates a rectangular wave internal signal of the first phase and a rectangular wave internal signal of the second phase from the continuous wave signal of the first phase and the continuous wave signal of the second phase, respectively;
a first counter that sets a count value in response to a pulse edge of the rectangular wave internal signal of the first phase and resets the count value in response to a pulse edge of the rectangular wave output signal of the second phase;
a second counter that sets a count value in response to a pulse edge of the rectangular wave internal signal of the second phase and resets the count value in response to a pulse edge of the rectangular wave output signal of the first phase; and
an abnormality detector that detects an abnormality of the rotary encoder when the count value of at least one of the first and second counters reaches a prescribed value.
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Accused Products
Abstract
A signal output unit generates an A phase output signal of a rectangular wave and a B phase output signal of a rectangular wave from the A phase sinusoidal wave signal and the B phase sinusoidal wave signal, respectively and outputs the generated signals. An internal signal generating unit (comparator) generates an A phase internal signal of a rectangular wave and a B phase internal signal of a rectangular wave from the A phase sinusoidal wave signal and the B phase sinusoidal wave signal, respectively, which are further processed by counters, and an abnormality detector. Each counter resets in response to a pulse edge of a signal for detection. The abnormality detector detects an abnormality when the count value of at least one of counters reaches a prescribed value.
12 Citations
11 Claims
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1. A rotary encoder of an incremental type, comprising:
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a rotation detector that outputs a continuous wave signal of a first phase and a continuous wave signal of a second phase according to rotation of a rotating body, the continuous signal of the first phase and the continuous signal of the second phase having a phase difference from each other; a signal output unit that generates a rectangular wave output signal of the first phase and a rectangular wave output signal of the second phase from the continuous wave signal of the first phase and the continuous wave signal of the second phase, respectively and outputs the rectangular wave output signals of the first phase and the second phase from the rotary encoder; an internal signal generator that generates a rectangular wave internal signal of the first phase and a rectangular wave internal signal of the second phase from the continuous wave signal of the first phase and the continuous wave signal of the second phase, respectively; a first counter that sets a count value in response to a pulse edge of the rectangular wave internal signal of the first phase and resets the count value in response to a pulse edge of the rectangular wave output signal of the second phase; a second counter that sets a count value in response to a pulse edge of the rectangular wave internal signal of the second phase and resets the count value in response to a pulse edge of the rectangular wave output signal of the first phase; and an abnormality detector that detects an abnormality of the rotary encoder when the count value of at least one of the first and second counters reaches a prescribed value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of detecting an abnormality of a rotary encoder of an incremental type, comprising:
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outputting a continuous wave signal of a first phase and a continuous wave signal of a second phase from a rotation detector according to rotation of a rotating body, the continuous signal of the first phase and the continuous signal of the second phase having a phase difference from each other; generating a rectangular wave output signal of the first phase and a rectangular wave output signal of the second phase from the continuous wave signal of the first phase and the continuous wave signal of the second phase, respectively; outputting the rectangular wave output signals of the first phase and the second phase from the rotary encoder; generating a rectangular wave internal signal of the first phase and a rectangular wave internal signal of the second phase from the continuous wave signals of the first phase and the second phase; setting a first count value in response to a pulse edge of the rectangular wave internal signal of the first phase and resetting the first count value in response to a pulse edge of the rectangular wave output signal of the second phase; setting a second count value in response to a pulse edge of the rectangular wave internal signal of the second phase and resetting the second count value in response to a pulse edge of the rectangular wave output signal of the first phase; and detecting an abnormality of the rotary encoder when at least one of the first and second count values reaches a prescribed value. - View Dependent Claims (9, 10, 11)
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Specification