The sensor is configured to provide a digital output signal and has a digital detector, which is configured to detect a physical quantity and generate a conditioned digital signal indicative of the detected physical quantity; and a rate modification stage, configured to receive the conditioned digital signal and a group of parameters, the group of parameters comprising an interpolation factor and a downsampling factor, and to provide the digital output signal. The rate modification stage has an interpolator and a decimation element. The interpolator is configured to receive and to upsample the conditioned digital signal based on the interpolation factor and to provide an interpolated signal. The decimation element is configured to downsample the interpolated signal based on the downsampling factor, thereby generating the digital output signal.

A phase detector includes a sampling signal generator configured to generate a sampling signal at an edge of a scale signal, a counter configured to count up a count value according to a clock pulse every certain time and to output the count value at a timing instructed by the sampling signal, an edge polarity determinator configured to determine whether an edge polarity of the scale signal is a rising edge or a falling edge and to generate an adjustment signal when the polarity of the edge where the sampling signal is generated is a falling edge and an adjuster configured to add a predetermined adjustment amount to the count value output from the counter when receiving the adjustment signal.

An encoder includes a scale having a pattern to be detected, a detecting sensor outputting a signal corresponding to the pattern, a position calculator calculating a relative position between the scale and the detecting sensor based on the signal, a position data storage storing the calculated position data, and a position estimator estimating a relative position between the scale and the detecting sensor at a calculation-target time point based on the stored position data. The position estimator estimates the position at the calculation-target time point based on positions at first and second time points each preceding the calculation-target time point by a predetermined time. The position estimator processes position data in a first time width centered on the first time point and position data in a second time width centered on the second time point to calculate the positions at the first and second time points.

There is provided a position detection device to suppress an influence of a signal distortion due to a processing error, an assembly error of a sensor, or the like. The position detection device includes: a waveform correction unit that corrects waveforms of a first signal and a second signal, the first signal being detected from a first track provided on a moving body and having a scale of predetermined cycles, and the second signal being detected from a second track provided on the moving body and having a scale of cycles less than the predetermined cycles; and a position calculation unit that calculates a position of the moving body on the basis of the corrected first signal and second signal.

A method for detecting a phase on a gear includes obtaining a first determination result indicating whether the gear has been detected at a first detection position. A second determination result indicating whether the gear has been detected at a second detection position is obtained. A third angle between the first and second angles is obtained. A third determination result indicating whether the gear has been detected at a third detection position is obtained. The first angle is replaced with the third angle when the third and first determination results are same, or the second angle is replaced with the third angle when the third and first determination results are different. The phase on the gear is detected based on an angle that is between the first angle and the second angle.

There is provided a position detection device to suppress an influence of a signal distortion due to a processing error, an assembly error of a sensor, or the like. The position detection device includes: a waveform correction unit that corrects waveforms of a first signal and a second signal, the first signal being detected from a first track provided on a moving body and having a scale of predetermined cycles, and the second signal being detected from a second track provided on the moving body and having a scale of cycles less than the predetermined cycles; and a position calculation unit that calculates a position of the moving body on the basis of the corrected first signal and second signal.

There is provided a position detection device to suppress an influence of a signal distortion due to a processing error or the like, the position detection device including: a reference position calculation unit that calculates a reference position of a moving body on the basis of a first signal and a second signal, the first signal being detected from a first track provided on the moving body and having a scale of predetermined cycles, and the second signal being detected from a second track provided on the moving body and having a scale of cycles less than the predetermined cycles; a slit specifying unit that specifies a slit corresponding to a position of the moving body; an in-slit position calculation unit that calculates an in-slit position of the moving body in the specified slit; and a correction unit that corrects an absolute position of the moving body.

There is provided a position detection device to suppress an influence of a signal distortion due to a processing error or the like, the position detection device including: a reference position calculation unit that calculates a reference position of a moving body on the basis of a first signal and a second signal, the first signal being detected from a first track provided on the moving body and having a scale of predetermined cycles, and the second signal being detected from a second track provided on the moving body and having a scale of cycles less than the predetermined cycles; a slit specifying unit that specifies a slit corresponding to a position of the moving body; an in-slit position calculation unit that calculates an in-slit position of the moving body in the specified slit; and a correction unit that corrects an absolute position of the moving body.

A method for detecting a phase on a gear includes obtaining a first determination result indicating whether the gear has been detected at a first detection position. A second determination result indicating whether the gear has been detected at a second detection position is obtained. A third angle between the first and second angles is obtained. A third determination result indicating whether the gear has been detected at a third detection position is obtained. The first angle is replaced with the third angle when the third and first determination results are same, or the second angle is replaced with the third angle when the third and first determination results are different. The phase on the gear is detected based on an angle that is between the first angle and the second angle.

An encoder includes a scale having a pattern to be detected, a detecting sensor outputting a signal corresponding to the pattern, a position calculator calculating a relative position between the scale and the detecting sensor based on the signal, a position data storage storing the calculated position data, and a position estimator estimating a relative position between the scale and the detecting sensor at a calculation-target time point based on the stored position data. The position estimator estimates the position at the calculation-target time point based on positions at first and second time points each preceding the calculation-target time point by a predetermined time. The position estimator processes position data in a first time width centered on the first time point and position data in a second time width centered on the second time point to calculate the positions at the first and second time points.