Abstract: A seismic sensor 10 comprises an acceleration acquisition unit 21, an acceleration waveform generation unit 22, a frequency sensing unit 24, and an earthquake determination unit 25. The acceleration acquisition unit 21 detects vibration and measures the acceleration of the vibration. The acceleration waveform generation unit 22 generates an acceleration waveform that indicates the relation between the elapsed time and the acceleration measured by the acceleration acquisition unit 21. The frequency sensing unit 24 senses the frequency of the acceleration waveform generated by the acceleration waveform generation unit 22 using a zero-crossing method. The earthquake determination unit 25 determines whether or not there is an earthquake on the basis of the frequency sensed by the frequency sensing unit 24.

Abstract: A seismic sensor 10 comprises an acceleration acquisition unit 21, an acceleration waveform generation unit 22, a frequency sensing unit 24, and an earthquake determination unit 25. The acceleration acquisition unit 21 detects vibration and measures the acceleration of the vibration. The acceleration waveform generation unit 22 generates an acceleration waveform that indicates the relation between the elapsed time and the acceleration measured by the acceleration acquisition unit 21. The frequency sensing unit 24 senses the frequency of the acceleration waveform generated by the acceleration waveform generation unit 22. The earthquake determination unit 25 determines whether or not there is an earthquake by classifying acceleration waveforms into those in which the frequency sensed by the frequency sensing unit 24 is 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.

Abstract: Whether a human body is touching or not is detected highly accurately at high speed. Switch SW1 is turned on to charge condenser Ca by power supply Vcc. The switch SW1 is turned off to transfer the electric charge charged in the condenser Ca to condensers Cs and Cx. The switches SW2 and SW3 are 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.

Abstract: Whether a human body is touching or not is detected highly accurately at high speed. Switch SW1 is turned on to charge condenser Ca by power supply Vcc. The switch SW1 is turned off to transfer the electric charge charged in the condenser Ca to condensers Cs and Cx. The switches SW2 and SW3 are 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.