Omron Corporation

Hideyuki Urata

Akinori Narumiya

Masahiro Kinoshita

Yoshihiro Tanabe

Hideshi Tsugui

A seismic sensorcomprises an acceleration acquisition unit, an acceleration waveform generation unit, a frequency sensing unit, and an earthquake determination unit. The acceleration acquisition unitdetects vibration and measures the acceleration of the vibration. The acceleration waveform generation unitgenerates an acceleration waveform that indicates the relation between the elapsed time and the acceleration measured by the acceleration acquisition unit. The frequency sensing unitsenses the frequency of the acceleration waveform generated by the acceleration waveform generation unit. The earthquake determination unitdetermines whether or not there is an earthquake by classifying acceleration waveforms into those in which the frequency sensed by the frequency sensing unitis above a specific threshold and those in which the frequency is below the specific threshold, and excluding any acceleration waveforms in which the frequency is above the specific threshold.

Seismic sensor, earthquake detection method, and earthquake detection program

A seismic sensorcomprises an acceleration acquisition unit, an acceleration waveform generation unit, a frequency sensing unit, and an earthquake determination unit. The acceleration acquisition unitdetects vibration and measures the acceleration of the vibration. The acceleration waveform generation unitgenerates an acceleration waveform that indicates the relation between the elapsed time and the acceleration measured by the acceleration acquisition unit. The frequency sensing unitsenses the frequency of the acceleration waveform generated by the acceleration waveform generation unitusing a zero-crossing method. The earthquake determination unitdetermines whether or not there is an earthquake on the basis of the frequency sensed by the frequency sensing unit

Whether a human body is touching or not is detected highly accurately at high speed. Switch SWis turned on to charge condenser Ca by power supply Vcc. The switch SWis turned off to transfer the electric charge charged in the condenser Ca to condensers Cs and Cx. The switches SWand SWare repeatedly turned on and off for a predetermined short time, and thus the electric charge charged in the condenser Ca is slowly discharged through resistor R. The unknown charging voltage Vx of the condenser Cx is compared with the reference voltage Vref by comparator Comp, and the unknown capacitance of the condenser Cx is computed based on the number of times to count turning on and off until it is smaller than the reference voltage Vref. When the computed unknown capacitance of the condenser Cx is the value near the capacitance of a human body, it is determined that a human body is touching. The invention can be applied to a touch sensor.

Growing community of inventors

Kusatsu, Japan

Hideyuki Urata