| 摘要 |
PROBLEM TO BE SOLVED: To enable a highly accurate measurement of pressure force in pressure sensors.SOLUTION: In a pressure detection device 1, a pressure sensor 3 has a piezoelectric sheet 21 that generates a piezoelectric signal in accordance with a given load, and a touch detection unit 7 detects a contact with the pressure sensor 3. A switch 11 is switchable between an electric charging state of a capacitance 27 and an electric discharging state thereof, and an AD conversion unit 39 converts an analog voltage signal to be output from an integration circuit 5 into a digital voltage signal. An acquisition unit 36 acquires the digital voltage signal in the electric charging state of the capacitance 27, and a switch unit 35 controls the switch 11 to alternately repeat the electric charging state of the capacitance 27 and the electric discharging state thereof, and puts the capacitance 27 into the electric discharging state for a prescribed time after the digital voltage signal is acquired. A calculation unit 37 adds the digital voltage signals acquired while the touch detection unit 7 detects the contact with the pressure sensor 3, and calculates a pressure force measurement value.SELECTED DRAWING: Figure 1 |
