Denso Corporation

Kenji Chikuan

Michitake Kuroda

Atsushi Kobayashi

Kazuhiko Koga

Haruhiko Miyagawa

A rotation detection apparatus includes a signal detector and a determination circuit. The signal detector outputs a first signal and a second signal based on changes in respective resistance values of magnetoresistive element pairs. The first signal has a waveform corresponding to convexities and concavities of a rotor, while the second signal has a waveform differing in phase from the first signal. Upon receiving the first signal and second signal, the determination circuit compares each of the first signal and second signal against a binarization threshold value to generate a first binarized signal and a second binarized signal. The determination circuit permits output of the first binarized signal during one of a concavity period and a convexity period of the second binarized signal, and prohibits output of the first binarized signal during the other one of the concavity period and convexity period.

Rotation detection apparatus

A semiconductor sensor chip is interposed between a sensor case and a housing. A first pressure is introduced from the sensor case and applied to a rear surface of the sensor chip, while a second pressure is introduced from the housing and applied to a front surface of the sensor chip. The sensor chip detects a pressure difference between the first and the second pressures and converts it into an electrical signal. The sensor chip is hermetically mounted in a depressed portion formed in the sensor case by charging a sealing material from holes formed around the depressed portion. The charging holes are positioned between terminals electrically connecting the sensor chip to an outside circuit to avoid enlarging the pressure sensor size by forming the charging holes.

Pressure sensor having semiconductor sensor chip

In a pressure sensor, a sensor element is mounted on a side of a first surface of a first case, and a second case having a cylindrical hollow portion is bonded to the first case to cover a part of a second surface of the first case, opposite to the first surface. Terminals are embedded in the first case to protrude from the second surface, and branch portions are branched from the terminals from an embedded portion in the first case to have exposed portions exposed to the second surface. A chip capacitor is mounted on the exposed portions on the second surface to be electrically connected to the exposed portions. In the pressure sensor, a diameter (D ) of the second surface of the first case is larger than an inner diameter (D ) of the hollow portion at a position where protrusion top ends of the terminals are positioned.

Pressure sensor and method for manufacturing the same

A pressure detection apparatus is manufactured by fitting an end portion of a first case into an opening portion of a second case, filling a space, which is defined between the end portion of the first case and an opening edge portion of the second case, with adhesive, and hardening the adhesive. Accordingly, variations in volume of a pressure detection chamber sealed between the first case and the second case can be reduced, resulting in decreased variations in output.

Growing community of inventors

Kariya, Japan

Kenji Chikuan