Abstract: An encoder sampling a first phase (A) signal and second phase (B) signal with phases differing from each other by about 90 degrees at the same timing, converting them from an analog to digital format, and detecting an angle signal based on the obtained digital signals, provided with offset detection circuits using a second phase A/D converted value (BD) of when a first phase A/D converted value (AD) is near a first value (XA) to find a second phase (B) offset value (Bofs), using a first phase A/D converted value (AD)of when a second phase A/D converted value (BD) is near a second value (XB) to find a first phase (A) offset value (Aofs), and using the currently found first offset value (Aofs) for the first value (XA) and the currently found second offset value (Bofs) for the second value (XB)when calculating the next first offset value (Aofs) and second offset value (Bofs) and a subtraction circuits using a first offset value (Aofs) and second offset value (Bofs) to correct offsets of the first phase signal an

Abstract: An encoder that can detect the presence of noise occurring within the encoder. The encoder is constructed by incorporating within the same apparatus: a movement detecting unit for detecting the movement of a moving body; a signal processing circuit for processing a movement detection signal supplied from the movement detecting unit, and thereby producing an encoder signal representing the position and/or the amount of displacement of the moving body; and a noise detecting unit for detecting noise superimposed on the movement detection signal. According to this encoder, a noise voltage generated within the encoder via a stray capacitance is detected within the encoder and is output as noise data, so that the noise level can be detected without requiring the use of an external measuring device. Further, by outputting encoder data and noise data occurring at the same instant in time, the reliability of the encoder data can be judged based on the condition of the noise level.

Abstract: A magnetic type angle sensor includes a rotary body having a first sensed part provided on a circumferential surface thereof with projecting parts and recessed parts at equal intervals in a circumferential direction thereof and a second sensed part provided on a circumferential surface thereof with a projecting parts at just one location, and a magnetic sensing device for sensing a change in a magnetic field along with rotation of the rotary body. The rotary body is formed with a plurality of projecting parts and recessed parts in a gear shape by gear cutting on the circumferential surface, then is cut with a groove at the center thereof in the axial direction thereof and has all projecting parts in a half section in the axial direction thereof cut off except for one.

Abstract: In an encoder which is equipped with two detectors arranged on both sides of a rotating shaft in order to eliminate an eccentricity error, the mounting of the detectors is facilitated by making provisions so as to not cause a problem in the calculating of an average even if the detectors happen to be so mounted that the difference between the angular values calculated from the outputs of the respective detectors becomes equal to 180°. In an initialization process after power on, the difference ?? between the angular values ?1 and ?2 calculated from the signals output from the respective detectors is stored as an initial value. Position data ? is output by taking an average between ?3 and ?2, where ?3 is a value obtained by correcting ?1 by the initial difference ??.

Abstract: A self-diagnosing system for an encoder. The system includes an encoder circuit for outputting information detected by an encoder; a data preparing section provided in the encoder circuit and preparing data representing a state of an abnormal-state judgment factor in connection with at least one of the encoder and an electric motor combined with the encoder; a signal generating section provided in the encoder circuit and generating an abnormal-state signal when the data prepared in the data preparing section represents an abnormal state of the abnormal-state judgment factor; and a storage section provided in the encoder circuit and storing the data representing a state of the abnormal-state judgment factor when the signal generating section generates the abnormal-state signal. The storage section may store the data prepared in the data preparing section at a desired timing not later than the instant the signal generating section generates the abnormal-state signal.

Abstract: The invention aims to suppress or prevent the vibration that can occur due to the intervention of a low-rigidity part between detector and rotating body. An angular acceleration sensor for detecting the rotational angular acceleration of a rotating body is provided, and an angle/angular speed command value is compensated in accordance with the value of the angular acceleration.

Abstract: The invention aims to reduce an error occurring due to the mounting condition of an acceleration sensor. In the case of a two-axis sensor, an angle ? is calculated from outputs (x?, y?) that the acceleration sensor produces when known accelerations (x, y) are applied, and the angle ? is stored in a storage device contained in a casing in which the acceleration sensor is housed. In the case of a one-axis sensor, the ratio of the magnitudes of accelerations is stored. The acceleration detected by the acceleration sensor is compensated by using the value stored in the storage device.

Abstract: A fan having a function for detecting a fault such as a breakage or a loss of a rotating part of the fan as well as reduction in the rotational speed of the fan, the function being not affected by an operating condition of the fan. The fan includes a stationary part, a rotating part rotatably attached to the stationary part, a first electric circuit arranged on the rotating part, a second electric circuit arranged on the stationary part, the second electric circuit being electromagnetically connected to the first circuit, and a fault detecting circuit electrically connected to the second electric circuit, for detecting a fault of the rotating part.

Abstract: The invention aims to detect only an angular acceleration without using an angular acceleration sensor, even in a situation where not only acceleration due to rotational motion but also acceleration due to translational motion is expected. Two acceleration sensors are mounted on a rotating body at positions located on the same radial line and are oriented in a direction that detects the tangential acceleration of the rotation, and the angular acceleration of the rotation is calculated from accelerations X1 and X2 detected by the two sensors.

Abstract: The invention aims to suppress or prevent the vibration that can occur due to the intervention of a low-rigidity part between detector and rotating body. An angular acceleration sensor for detecting the rotational angular acceleration of a rotating body is provided, and an angle/angular speed command value is compensated in accordance with the value of the angular acceleration.

Abstract: A driving control apparatus that can judge whether there is any abnormality in the operation of an acceleration sensor as well as in the mounting direction thereof. The driving control apparatus which controls the operation of a driven part via a driving device is constructed to include an abnormality judging circuit which, based on acceleration information from the acceleration sensor, judges the presence or absence of an abnormality in the operation of the acceleration sensor, or the mounting thereof with respect to the driven part, in addition to a position sensor or velocity sensor which detects the position or velocity of the driven part and the acceleration sensor which detects the acceleration of the driven part separately from the position sensor or velocity sensor.

Abstract: The invention aims to reduce an error occurring due to the mounting condition of an acceleration sensor. In the case of a two-axis sensor, an angle ? is calculated from outputs (x?, y?) that the acceleration sensor produces when known accelerations (x, y) are applied, and the angle ? is stored in a storage device contained in a casing in which the acceleration sensor is housed. In the case of a one-axis sensor, the ratio of the magnitudes of accelerations is stored. The acceleration detected by the acceleration sensor is compensated by using the value stored in the storage device.

Abstract: In a control apparatus, a “characteristic value calculation” block calculates a characteristic value (such as amplitude value, offset value, or waveform distortion for each phase of two-phase sinusoidal signals optically input from an encoder, or phase difference between the two phase signals) for each of the two-phase sinusoidal signals, and an “alarm detection” block checks the presence or absence of an excursion outside a predetermined allowable range and, if such an excursion is detected, produces an alarm indication or the like. Each time the “present characteristic value” is input, a “characteristic value comparison” block compares it with “previous characteristic values”, and analyzes the result of the comparison. That is, the difference between the present value and each previous data is calculated, and the largest amount of variation (with plus or minus sign) is obtained; if this amount is larger than a predetermined value, a signal indicating an “imminent failure” is output.

Abstract: An assembly of electric motor with encoder, including an electric motor having a motor housing, and an encoder for detecting the rotation angle of the output shaft of the electric motor. The encoder includes a frame member attached to the motor housing in a conductive manner, a circuit board supported on the frame member and a detection circuit provided in the circuit board. The assembly of electric motor with encoder further includes an output signal cable connected to the circuit board of the encoder and including a signal wire and a shield member, and a grounding mechanism electrically connecting the shield member of the output signal cable to the motor housing for grounding purposes. The grounding mechanism includes a conductor patterned on the circuit board, a first connecting structure mutually connecting the conductor to the shield member, and a second connecting structure mutually connecting the conductor to the frame member.

Abstract: A magnetic type angle sensor includes a rotary body having a first sensed part provided on a circumferential surface thereof with projecting parts and recessed parts at equal intervals in a circumferential direction thereof and a second sensed part provided on a circumferential surface thereof with a projecting parts at just one location, and a magnetic sensing device for sensing a change in a magnetic field along with rotation of the rotary body. The rotary body is formed with a plurality of projecting parts and recessed parts in a gear shape by gear cutting on the circumferential surface, then is cut with a groove at the center thereof in the axial direction thereof and has all projecting parts in a half section in the axial direction thereof cut off except for one.

Abstract: A linear encoder comprises a light source, a main scale provided with a measuring pattern having a constant pitch, an index scale to which a measuring pattern having a constant pitch is mounted, and a light receiving element. The light receiving element detects the brightness generated by these patterns superposed one upon another by relative movement of the main scale with respect to the index scale. The linear encoder further comprises pattern end detecting means for detecting the end portion of the measuring pattern provided on the main scale so that the position of the end portion is used as an origin of the encoder.

Abstract: After cyclic original signals generated from a sensing element of an encoder are converted into digital signals, positions P(0) to P(n) in one period are obtained for each given period by means of a digital interpolator. If position data obtained immediately after a zero cross point is detected are P(0) and P(n) and if speed is fixed, an object should move on a straight line from a position P(0) to a position P(n). An actual detected position data P(m) is deviated from this straight line by D(m). This detection error D(m) and the detected position data P(m) are combined and stored in advance as reference data, and correction is carried out using the reference data every time position data is detected by the digital interpolator.

Abstract: In a control apparatus, a “characteristic value calculation” block calculates a characteristic value (such as amplitude value, offset value, or waveform distortion for each phase of two-phase sinusoidal signals optically input from an encoder, or phase difference between the two phase signals) for each of the two-phase sinusoidal signals, and an “alarm detection” block checks the presence or absence of an excursion outside a predetermined allowable range and, if such an excursion is detected, produces an alarm indication or the like. Each time the “present characteristic value” is input, a “characteristic value comparison” block compares it with “previous characteristic values”, and analyzes the result of the comparison. That is, the difference between the present value and each previous data is calculated, and the largest amount of variation (with plus or minus sign) is obtained; if this amount is larger than a predetermined value, a signal indicating an “imminent failure” is output.

Abstract: A servo motor controller for controlling a machine includes a first receiver circuit for receiving signals from an encoder that detects the position of the machine and a second receiver circuit for receiving signals sent from a sensor unit. The first receiver circuit has the same configuration as the second receiver circuit, and the same interface is used between the sensor unit and the second receiver circuit as is used between the encoder and the first receiver circuit.

Abstract: An amplitude of an electrical signal generated on the basis of a light detected by a light receiving part of an optical encoder is monitored and, using the monitored result, a displacement between a moving scale and fixed slits of an optical encoder (or a displacement of a moving part in a motor attached with an optical encoder) is detected. Further, a load applied to a moving part in a motor attached with an optical encoder is detected using the monitored result.