Mitutoyo Corporation

Toshiro Horikawa

Mikio Suzuki

Souji Ichikawa

Shingo Kuroki

Yoichi Toida

Wataru Ishibashi

A measuring apparatus employing a differential transformer includes a high-frequency oscillator which generates a high-frequency signal having a frequency higher than the excitation frequency of the differential transformer, a frequency divider which divides the high-frequency signal to generate a driving signal for the differential transformer, a multiplier or divider which reduces the frequency of the high frequency signal by the frequency of the driving signal, a mixer which mixes the output from the multiplier or the divider with the output from the differential transformer, a high-pass filter or a band-pass filter which cuts a low-frequency component of the output from the mixer, and a double balanced mixer which synchronously detects the output from the high-pass filter or the band-pass filter with the use of the high-frequency signal. With the use of the thus configured apparatus, an output signal having a fast response speed can be obtained through the use of an existing head having a low excitation frequency.

Signal processing apparatus and method of differential transformer

The object of present invention is to provide a sensitivity calibrating method for a detector of a comparator, which enables easy and highly accurate sensitivity calibration for a first and a second detector for measuring opposing position of an object. Heights of two pairs of reference gauge blocks, a first reference gauge block W1 and a second reference gauge block W2, and the second reference gauge block W2 and a third reference gauge block W3 is first measured, and thereafter, sensitivity coefficients for calibrating the sensitivity of an upper detector 10 and a lower detector 20 are calculated by applying the measured value to a predetermined formula. The calculation is repeated three times, and each value is renewed for the upper and the lower detector 10 and 20 respectively.

Sensitivity calibrating method for detector of comparator

In one type of an angular velocity sensor, a constant vibration is applied in an X direction to one end of a vibrator which is fixed at another end and the vibrator vibrates in a Y direction perpendicular to the X direction by an action of Coriolis force caused by the angular velocity of the vibrator about the Z axis with an amplitude proportional to an angular velocity about a Z axis. An angular velocity sensor of this invention utilizes a photoelectric encoder for measurement of the vibration amplitude of the vibrator in the Y direction. The encoder includes a main scale mounted on the free end of the vibrator; an index scale mounted on a housing of the sensor to face the main scale; and a photoelectric element for sensing light reflected from the main scale and passing through the index scale. The angular velocity sensor utilizing the photoelectric encoder is less subject to influence of variation in the temperature in comparison with the conventional sensor utilizing piezoelectric elements and a higher precision can be attained.

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Kawasaki, Japan

Toshiro Horikawa