Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Takashi Okamuro

Hirokazu Sakuma

Hajime Nakajima

Yoichi Ohmura

Takeshi Musha

Toshikazu Satone

Toru Oka

Toshiro Nakashima

Yoichi Omura

Noriyasu Hasegawa

Hiroshi Nishizawa

Jin Inoue

Koichi Sugimoto

Masahiko Sakamoto

Yoshinao Tatei

Yukio Aoki

Hiroo Sakamoto

Masanori Nimura

Tsuneo Hamaguchi

Hiroshi Sugie

Takumi Asano

Yoshimitsu Sato

Hiroshi Nagata

Takashi Shirase

Kosuke Shamoto

Ikio Sugiura

Mikio Iijima

Yohichi Ohmura

Masaki Iwata

Provided is a magnetic rotation-angle detector that includes a disk-shaped magnet that is magnetized so as to change magnetic poles n times per rotation (where n is an integer equal to or larger than 1); a magnetic-body slit plate that is rotated together with the magnet, where a part having a high magnetic flux permeability and a part having a low magnetic flux permeability are alternately and repeatedly arranged thereon so as to change the magnetic flux permeability m times per rotation (where m is an integer equal to or larger than 2 and m&#x3e;n); a magnetic sensor that detects magnetism from the magnet when the magnet has passed by through the magnetic-body slit plate; and a calculation unit that obtains the rotation angle of the magnet from the output from the magnetic sensor.

Magnetic rotation-angle detector

A rotation number detector according to an embodiment is a rotation number detector that detects the number of rotations of a magnet attached to a rotating body by using a power generation unit. The power generation unit includes N (N is a natural number equal to or larger than 1) power generation elements, each including a magnetic wire in which magnetization reversal occurs due to a large Barkhausen effect and a pickup coil that is wound around the magnetic wire. The magnetic wire is longer than a wound portion of the pickup coil in an extension direction of the magnetic wire of the power generation elements. The magnetic wire is set above a rotation center of the magnet.

Rotation number detector

A detection track includes a first detection element group that includes a plurality of first magnetic resistance elements arranged at a pitch &#x3bb;/(2n) when an order to cancel target harmonic components among a plurality of harmonic components superimposed on a fundamental component of a detection signal for multi-pole magnetic pattern is assumed as n, and a second detection element group that includes a plurality of second magnetic resistance elements arranged at the pitch &#x3bb;/(2n), a plurality of first dummy magnetic resistance elements arranged among the first magnetic resistance elements, and a plurality of second dummy magnetic resistance elements arranged among the second magnetic resistance elements. Pitches between adjacent magnetic resistance elements among the first magnetic resistance elements and the first dummy magnetic resistance element are equivalent to one another, and pitches between adjacent magnetic resistance elements among the second magnetic resistance elements and the second dummy magnetic resistance element are equivalent to one another.

Rotation-angle detection device

The encoder includes a plurality of position-detection-signal generation systems that generates electrical signals as position detection signals having different cycles, respectively; a first computing unit that calculates first position data based on the position detection signals generated by the position-detection-signal generation systems; a second computing unit that calculates second position data based on electrical signals generated by fewer ones of the position-detection-signal generation systems than in the first computing unit; and a failure determination unit that determines whether the encoder is defective based on a comparison between the first position data and the second position data.

Encoder

A rotary encoder includes a rotary encoding unit attached to a rotary shaft which is rotatably held in a metal casing, a number-of-revolution detection unit supported by the metal casing for detecting a number of revolutions of the rotary encoding unit and producing heat, a cylindrical insulating resin cover having a base end attached to the metal casing for accommodating therein the rotary encoding unit and the number-of-revolution detection unit, a metal lid for blocking an opening of the other end of the insulating resin cover, and a shield cable electrically connected to the number-of-revolution detection unit and drawn out from a cable outlet of the metal lid. A shield of the shield cable is heat-transferably and electrically connected to the metal lid.

Rotary encoder

A position detection error correcting method that corrects position detection errors using a limited storage capacity, by calculating position detection error correction values by four simple arithmetic operations at startup to reduce a startup time delay and consumption of a storage capacity even when a portion containing steep error variations exists. Detection error correction values of a position detector are expressed by a correction function using a periodic function, and correction parameters of the correction values are stored in advance in a non-volatile memory. At startup, these correction parameters are read out, and a position detection error correction value corresponding to each detected position is calculated and stored in a random access memory. The output position detection error correction value detector corresponding to each detected position is read out from the random access memory and a corrected detected position value corrected for the detected position value error is calculated.

Position detection error correcting method

An electronic device housing includes a metallic base part; a resin partfixed to the base part; and a printed circuit boardcoming into contact with the resin part; wherein bonding of the base partto the resin partis carried out by way of a nanomold technique and wherein the resin parthas insulating property.

Electronic device housing

A rotary type encoder is provided with a signal generating portionfor generating a sine wave signal of N periods for each revolution in accordance with the rotation of the shaftof a motor; a calculation means for obtaining the rotation angle of the shaftbased on the sine wave signal; an EEPROMbeing arranged in a manner that the error value of the rotation angle for one revolution of the shaftthus measured is divided in relation with the N periods to set a plurality of first angle regions i, the angle region almost at the center of the angle region i is divided into plural regions to set second angle regions j, and an error value corresponding to the angle at almost the center of each of the angle regions j is stored therein in correspondence with the rotation angle; and a correction means for reading the error value stored in the EEPROMin correspondence with the rotation angle to correct the rotation angle.

A photoelectric rotary encoder includes a light source that emits a light beam, a returning section that returns the emitted light beam to a direction opposite to an emitting direction of the beam, and a photodetector that is disposed on a substrate on which the light source is disposed and that detects the returned light beam via a disk having a detection pattern section. The photoelectric rotary encoder detects rotational displacement of the disk based on the detected returned light beam. In this photoelectric rotary encoder, an optical element that lets a stray beam component of the light beam from the light source escape via a side surface of the optical element, is disposed in front of the substrate on which the light source and the photodetector are disposed. The optical element covers the substrate and integrates the optical element and the substrate.

Photoelectric rotary encoder

A scale generates a periodic light-intensity distribution pattern having a pitch upon irradiation by emission light from a light source. Light-detecting element groups are shifted relative to the scale to generate phase signals having fixed phase differences. Light-detecting elements are adjacently positioned to have the same phase to form each light-detecting element group. Area centers of gravity on a phase axis of the light-detecting element groups having a fixed phase difference are made coincident with each other.

Phase-shift photoelectric encoder

An interference-type distance measuring device generates a reference beam having a first frequency and detection beam having a second frequency and directs these beams toward a moving detection unit which reflects these beams toward an interference system, where these beams are used to generate a detection interference wave. A reference interference wave generated by the interference system is converted into a first sine-wave signal, the interference detection wave is converted into a second sine-wave signal, first and second cosine-wave signals are generated from the first and second sine-wave signals, and the position of the motion detection unit is detected based upon these four signals.

Interference-type distance measuring device

A position detection apparatus which can control an apparatus to be controlled, such as a motor or the like, more precisely, is disclosed. When a predetermined time has passed since reception of a request signal for requesting output of the position data was detected, the position detector measures the output of a sensor for detecting the position of an object to be measured, and calculates the position data representing the position of the object at a point of time when the measurement was performed, based on the measured output. Moreover, the position detector measures the reception interval of the request signal, calculates the corrected position data representing the position of the object at the time of receiving the request signal whose reception interval was measured, using a value obtained by subtracting the predetermined time from the measured reception interval, the calculated position data, and a change rate in a presumed position of the object, and outputs the corrected position data as a response to the request signal.

Position detection apparatus

An absolute-value encoder device for detecting a plurality of rotation quantities is disclosed. An A/B phase forming portion,forms an A-phase pulse signal and a B-phase pulse signal, based on light passing through a slit rotating together with a rotary shaft. One period of each of those pulse signals corresponds to one revolution of a rotary shaft. The A- and B-phase pulse signals are displaced in phase by 90&deg; from each other. When an A/B-phase state detecting portion,detects a state change of each of those pulse signals, a clock forming portion,changes a frequency of a clock pulse signal to another frequency.

Absolute-value encoder device

In a position detecting apparatus which detects an absolute position by A/D converting sinusoidal and cosinusoidal signals and performing interpolation, a phase error between the signals which is caused by movement of a detection object during the A/D conversion is corrected, thereby enabling sample hold circuits which have been necessary for maintaining the synchronism of analog signals to be omitted, so as to realize the cost reduction and miniaturization. This is enabled also in an apparatus of high resolution. Position data at requests of the last and preceding times are stored into a RAM,On the basis of the position data, a CPU,predicts the amount of a phase shift of another signal due to movement during A/D conversion of one signal, corrects the predicted phase shift amount, and then calculates the position data.

Growing community of inventors

Tokyo, Japan

Takashi Okamuro