The present invention provides: a rotary encoder checking an eccentricity state of a scale by sensor units; and related matters. The scale moves, relatively to the sensor units, around a rotational axis line. The pair of sensor units are arranged opposite to each other sandwiching the rotational axis line C0 therebetween. A processing system acquires output signals from each of the sensor units, at a plurality of rotation angles at which the scale has moved relatively to the sensor units. The processing system determines first phase information based on the output signal obtained from the sensor unit, and second phase information based on the output signal obtained from the sensor unit. The processing system determines eccentricity information based on a differential value between any one of the first phase information and the second phase information and an average value of the first phase information and the second phase information.

To reduce costs by adopting a direct modulation system in which a semiconductor laser is directly modulated. An optical fiber sensor includes a light source configured to generate an optical pulse as probe light by a direct modulation system, an optical bandpass filter configured to extract anti-Stokes light that is a component on an anti-Stokes side of Brillouin scattered light from backscattered light generated by the probe light in an optical fiber to be measured, an interference signal acquisition unit configured to generate an interference signal by self-delayed heterodyne interference from the anti-Stokes light extracted at the optical bandpass filter and input to the interference signal acquisition unit and a Brillouin frequency shift acquisition unit configured to acquire a Brillouin frequency shift amount from the interference signal.

The present application relates to a photon measuring and reading device, which belongs to the field of detection equipment, including a mounting seat and a photon counter. The photon counter can move up and down on the mounting seat. The mounting seat is provided with a vertically arranged sliding trough, and the photon counter is provided with a sliding rod slidably connected with the sliding trough. A double head motor is arranged on the mounting base, and a linkage mechanism is arranged between the output shaft at the tail end of the double head motor and the sliding rod. The bottom end of the photon counter is fixed with a box body.

The present application relates to a photon measuring and reading device, which belongs to the field of detection equipment, including a mounting seat and a photon counter. The photon counter can move up and down on the mounting seat. The mounting seat is provided with a vertically arranged sliding trough, and the photon counter is provided with a sliding rod slidably connected with the sliding trough. A double head motor is arranged on the mounting base, and a linkage mechanism is arranged between the output shaft at the tail end of the double head motor and the sliding rod. The bottom end of the photon counter is fixed with a box body.

There is provided an optical encoder with alignable relative positions between elements including an encoding medium, a sensor package and a memory. The sensor package includes a photodiode array and two alignment photodiodes opposite to the encoding medium. The memory records an alignment pattern associated with output signals of the two alignment photodiodes when the encoding medium and the sensor package are at nominal operating positions. When the encoding medium and the sensor package are not at the nominal operating positions, the relative position alignment is performed by adjusting current relative positions between the encoding medium and the sensor package to cause a current pattern associated with output signals of the two alignment photodiodes to be identical to the alignment pattern.

An encoder according to an embodiment of this disclosure includes a voltage generation circuit connected to a power supply through a diode and having a variable resistor, the voltage generation circuit outputting a voltage corresponding to a current flowing through the diode and a resistance value of the variable resistor, as a threshold value; a comparator for performing a comparison between an analog signal inputted from a detector for detecting rotation of a motor and the threshold value inputted from the voltage generation circuit, and outputting a comparison result as a comparator output; a resistance value variation circuit for varying the resistance value of the variable resistor; and a threshold value determination circuit for determining the threshold value based on a relationship between the resistance value and the comparator output.

An encoder according to an embodiment of this disclosure includes a voltage generation circuit connected to a power supply through a diode and having a variable resistor, the voltage generation circuit outputting a voltage corresponding to a current flowing through the diode and a resistance value of the variable resistor, as a threshold value; a comparator for performing a comparison between an analog signal inputted from a detector for detecting rotation of a motor and the threshold value inputted from the voltage generation circuit, and outputting a comparison result as a comparator output; a resistance value variation circuit for varying the resistance value of the variable resistor; and a threshold value determination circuit for determining the threshold value based on a relationship between the resistance value and the comparator output.

An encoder apparatus comprising a readhead moveable relative to a scale, configured to produce a position signal, as well as to produce a reference mark signal when the readhead passes over a reference mark on the scale, configured such that the process for producing the reference mark signal adapts automatically in response to a change in circumstance so as to at least pursue maintenance of a given relationship between the position and reference mark signals.

An encoder apparatus comprising a readhead moveable relative to a scale, configured to produce a position signal, as well as to produce a reference mark signal when the readhead passes over a reference mark on the scale, configured such that the process for producing the reference mark signal adapts automatically in response to a change in circumstance so as to at least pursue maintenance of a given relationship between the position and reference mark signals.

A method of determining a direction of rotation of a shaft is disclosed, as well as an integrated circuit chip that uses the disclosed method. The method includes receiving a first binary signal and a second binary signal from a transducer attached to the shaft, with the first and second binary signals being in quadrature. A present quadrant identification number, QID.sub.PRESENT, is determined as a two-digit binary number by left-shifting a value of the first signal and adding a value of the second signal. After a sampling interval has elapsed, the method sets a past quadrant identification number, QID.sub.PAST, to the value of said QID.sub.PRESENT, determines a new value of QID.sub.PRESENT and calculates a value of a transition code using an equation that operates on QID.sub.PRESENT and QID.sub.PAST. The method uses the transition code to determine a direction of rotation of the shaft.