Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Cornoration

Yoshinori Tatenuma

Masahiro Yokotani

Hideki Shimauchi

Yuji Kawano

Izuru Shinjo

Hiroshi Kobayashi

Akira Koshimizu

Kazuyasu Nishikawa

Hiroshi Sakanoue

Manabu Tsukamoto

Akio Kamimurai

Shigeki Tsujii

Ryouichi Sasahara

Takashi Tokunaga

Junichi Ichikawa

Tetsuo Amano

Kanji Kitamura

Mutsuo Daito

Masatoshi Uchino

Takeharu Umegami

The magnetic detection device includes: a first magnetic rotary body which rotates about a rotation shaft and has an outer circumferential portion which is a magnetic body; a second magnetic rotary body has an outer circumferential portion which is a magnetic body; a magnet which has a magnetization direction along the axial direction; a first magneto-resistive element provided on another side in the axial direction of the magnet; a second magneto-resistive element provided on one side in the axial direction of the magnet; a first magnetic guide provided between the magnet and the first magneto-resistive element; and a second magnetic guide provided between the magnet and the second magneto-resistive element, wherein the outer circumferential portion of the first magnetic rotary body and the outer circumferential portion of the second magnetic rotary body cause different magnetic fields between the magnet and the respective outer circumferential portions.

Magnetic detection device

To obtain a magnetic detection device which can detect a direction of movement of a magnetic moving body immediately right after a reset release of the magnetic detection device. The magnetic detection device includes a signal change detector which detects the peak, bottom, and gradient of an output signal of a first magnetoelectric conversion element group and the peak, bottom, and gradient of an output signal of a second magnetoelectric conversion element group, wherein a direction of movement of a magnetic moving body is detected based on the gradient of increase or decrease of one of the output signal or the output signal at the timing of a detection of the peak or bottom of the other.

There is provided a magnetic detection apparatus in which based on a second comparison signal or a first comparison signal, a second analog/digital conversion circuit or a first analog/digital conversion circuit converts a second amplification signal or a first amplification signal into a digital value at a time when the peak value of the first amplification signal or the second amplification signal is detected or at a time when the bottom value of the first amplification signal or the second amplification signal is detected, as the case may be, and that can implement at least one of actions in which based on comparison between the digital value converted and a predetermined reference value, a second threshold value adjusting apparatus or a first threshold value adjusting apparatus adjusts a second threshold value or a first threshold value, as the case may be.

Magnetic detection apparatus

Provided is a comparator configured to compare input voltages, which are input to a first dynamic comparator and a second dynamic comparator, with a reference voltage, select either an output signal of the first dynamic comparator or an output signal of the second dynamic comparator based on the comparison result, output the selected output signal, and control clock signals, which are input to the first dynamic comparator and the second dynamic comparator respectively, based on the comparison result, so as to stop the operation of the dynamic comparator of which output signal is not selected.

Comparator, AD converter, semiconductor integrated circuit, and rotation detector

Provided is an AD converter having a rail-to-rail input voltage range and being free of a missing code and monotonicity loss. A comparator includes a first comparator having an NMOS differential input stage, a second comparator having a PMOS differential input stage, and an output selection circuit configured to select any one of outputs of the two comparators. A correction circuit acquires in advance a first AD converted value in the case of using the first comparator and a second AD converted value in the case of using the second comparator with respect to the same input voltage to calculate a correction value, and performs correction processing based on the correction value to suppress an offset error between the first AD converted value and the second AD converted value.

Ad converter, semiconductor integrated circuit, and rotation detector

A magnetic detection in which a first element () and a second element () that are a magnetoresistance element whose resistance value changes in response to an external magnetic field are connected in series with each other so as to form a bridge circuit, one end of the bridge circuit is connected to a power supply (), the other end thereof is grounded, a connecting point () between the first element () and the second element () is connected to an amplifier means (), at least one switching means () is connected in series with the bridge circuit, and an output terminal () of the amplifier means () is connected to a failure detection means ().

A differential amplifier generates an offset correction signal based on a rotation detection signal from a rotation detector apparatus and an offset signal. A comparator compares the offset correction signal with a threshold voltage, and outputs a binarized signal representing the comparison result. An average value signal generator circuit generates an average value signal representing the average value of the offset correction signal. The offset signal generator circuit generates the offset signal so that the signal voltage of the average value signal has a voltage value between a threshold voltage and a threshold voltage.

Binarization circuit for binarizing detection signal representing rotation or movement of object

A magnetic detection apparatus includes a first comparison circuit that waveform-shapes the amplitude of a detection signal from magneto-electric transducers by DC coupling, a third comparison circuit that waveform-shapes the detection signal by AC coupling, an oscillation circuit having a natural frequency, a control circuit that counts the output of the first comparison circuit by using the oscillation means, and a selection circuit that selects the output of the first comparison means and the output of the second comparison means. The control circuit counts rising from the next rising or falling from the next falling of an output rectangular wave of the first comparison circuit, and provides output to the selection circuit at the time point at which the count value reaches a desired value. The selection circuit selects and outputs the output rectangular wave of the first comparison circuit or the third comparison circuit.

A magnetic detection device includes a signal processing circuit that detects a moving position and a moving direction of a magnetic mobile object using an output of a comparing circuit configured to output a signal by comparing an output signal of a magneto-electric transducer element with a threshold. A duration during which an output of the signal processing circuit is in a high level or in a low level is fixed to a period tor a period tdepending on the moving direction of the magnetic mobile object. When switching of the moving direction of the magnetic mobile object takes place within the period tor the period t, the signal processing circuit outputs a position signal same as a position signal indicating a position immediately before the switching of the moving direction of the magnetic mobile object due to hysteresis of the threshold of the comparing circuit.

Provided is an apparatus for detecting a moving direction that can accurately detect the position, regardless of the moving direction. The moving direction detector includes groups of sensor elements that face a moving body to output detection signals in accordance with travel of the moving body. The detector includes signal processing units that convert output signals of the groups of sensor elements into rectangular waves and a moving direction detection unit that outputs a signal corresponding to a moving direction of the moving body based on the detection signals from the groups of sensor elements. The moving direction detection unit includes a delay function of generating an output signal at a time instant that is delayed by a predetermined time from a time instant when a moving direction of the moving body is changed.

Moving direction detector

In a magnetic detection apparatus, a magnetic detection sensor generates a sensor output signal whose high level and low level have different potentials in accordance with the moving direction of a magnetic moving object, and a computer unit includes three comparator circuits and detects the output signal of the magnetic detection sensor with three levels of comparison threshold values, so that the moving direction of the magnetic moving object can be detected accurately without any delay.

A magnetic detection apparatus can be improved in its product yield. The magnetic detection apparatus includes a resin compact having a the magnet arranged in opposition to an object to be detected for generating a magnetic field, an IC chip with a magnetic detection part built therein for detecting a change in the magnetic field in accordance with movement of the object to be detected, and an IC package in which a lead frame having the IC chip installed thereon is sealed with a resin. A method for manufacturing such a magnetic detection apparatus includes a signal adjustment step for adjusting a signal generated from the magnetic detection part in a state in which the magnetic field is applied to the magnetic detection part to correct a deviation of the signal of the magnetic detection part generated in accordance with a relative displacement between the magnetic detection part and the magnet.

Method of manufacturing a magnetic detection apparatus

The invention provides a magnetic detector that exerts no influence on detection accuracy of a magnetic movable body, being a detected body, even if relative positions of magnetic resistance elements and a magnet are out of alignment due to variation occurred in manufacturing process. A magnetic detector includes: a magnetic field detection part constructed of at least two magnetic resistance elements; a magnet for applying a magnetic field to the magnetic resistance elements; a magnetic movable body for changing the magnetic field that is generated by the magnet; and a processing circuit part for outputting a signal based on the change in resistance values of the magnetic resistance elements due to the change in the magnetic field; and in which a shape of the magnetic resistance elements is symmetric with respect to a point.

Magnetic detector

Magnetic detection apparatus with resin infiltration prevention

There is provided a rotation information detecting apparatus which suppresses noise superimposed on an output line and can prevent detection of erroneous rotation information. A periodic changing magnetic field is applied to a detection element according to the rotation of a rotation object, and rotation information is detected. A signal processing circuit includes an output circuit for generating a binary output signal changing between a high level and a low level according to the rotation of the rotation object. The output circuit includes an output transistor, an output line connected to the output transister, a power supply terminal for the output transistor, and a noise suppression circuit connected between the output line and the power supply terminal a power supply terminal. The noise suppression circuit includes a diode and a current limiting resistor.

Growing community of inventors

Tokyo, Japan

Yoshinori Tatenuma