Yokogawa Electric Corporation

Yokogawa Hokushin Electric Corp.

Fusao Kohsaka

Toshitsugu Ueda

Hiroshi Nakayama

Toshio Iino

Daisuke Yamazaki

Toshitugu Ueda

Yoshiaki Kudou

Yasuhiro Sakamaki

Yoshinobu Sugihara

Hideo Akazawa

Toshi Iino

Kunio Kazami

A multi-turn absolute encoder comprising a shaft angle encoder for measuring the turning angle of a rotating shaft, and a turn detector for detecting the number of turns of the rotating shaft, wherein the turn detector uses a magnetic bubble element for sequentially transferring magnetic bubbles in a pattern in accordance with a magnetic field generated by a permanent magnet turned by the shaft, and a detector to detect the number of turns of the shaft from the positions of the magnetic bubbles which are transferred in the pattern.

Revolution counter using a magnetic bubble device for multi-turn

An encoder device of the absolute position type for outputting a shift position or angle of rotation relative to the absolute position. The device comprises a code plate having first and second grid patterns wherein information is stored as 1 or 0 in a periodic manner at pitches slightly different from each other; first and second sensory arrays for detecting the first and second grid patterns; driving means for driving the sensors relative to the grid patterns and for obtaining an alternating signal from each array; and computation means for measuring the phase angle of the alternating signal from each array, and the phase angle difference therebetween and for calculating the position using such phase angles. Advantageously, the invention is suitable for miniaturization due to its simplicity, relaibility, and efficiency.

Absolute encoder for linear or angular position measurements

A quartz thermometer adapted to measure the ambient temperature through detection of a change in the resonance frequency of a quartz resonator due to change in the temperature, wherein a quartz wafer of 0.02 to 0.2 mm thickness is cut from a region of a quartz within -30.degree. to -70.degree. in terms of rotation angle about the X axis of the quartz thereby to form a quart resonator within a range of between -15.degree. to +15.degree. in terms of angle of rotation about the Z' axis within the plane of the quartz wafer; and wherein thin metallic films are formed on the surfaces of the resonator to serve as exciting electrodes. The resonator and electrodes are produced by photolithography and anisotropic quartz etching processes. The resulting quartz thermometer has a large first order temperature coefficient of frequency.

Quartz thermometer

A pressure measuring apparatus comprising a diaphragm to which pressure to be measured is applied and a resilient vibrator connected to the diaphragm, which acts to produce a signal based on its natural frequency relative to the pressure, wherein the diaphragm comprises a peripheral circumferential portion, a central fixing portion and a non-planar intermediate portion therebetween, with the central portion being connected to the vibrator and having its edge disposed at a non-perpendicular angle with respect to the vibrator area to which it is connected. The apparatus eliminates adverse influences due to initial distortion, hysteresis of the diaphragm and produces accurate measurements.

Apparatus for measuring pressure

A pressure sensor which detects delicate changes in pressure as small as 0.01 .mu.m water column by detecting displacement or torque in a movable plate. The sensor comprises a fixed plate in which slits are formed, a movable plate on which pressure to be measured is impressed, a supporting member which supports the movable plate at two points on a straight line passing through its center of gravity so as to enable the movable plate to rotate thereabout, and a detecting means for detecting displacement or torque in the movable plate. The different pressures act on the movable plate to cause the rotation thereof and the displacement or torque so that such displacement corresponds to the pressure difference.

Pressure sensor

Herein disclosed is a mechanical vibrating element which can be used as a resonator made operative to resonate in a predetermined frequency, a filter having a frequency selecting property or an optical deflector adapted to be mechanically dislocated in accordance with an input signal for deflecting an optical beam. The mechanical vibrating element according to the present invention is characterized in that a single insulating substrate constructs a frame and a moving portion supported by the frame, in that the moving portion is formed with a conductive pattern or a coil, and in that an electric current is fed to the conductor or the coil, while appling a magnetic field in the same direction as the plane direction of the insulating substrate, so that the moving portions may be mechanically vibrated.

Growing community of inventors

Tokyo, Japan

Fusao Kohsaka