Invention Application
- Patent Title: CAPACITANCE DETECTION DEVICE AND CAPACITANCE DETECTION METHOD
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Application No.: US17721238Application Date: 2022-04-14
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Publication No.: US20220244299A1Publication Date: 2022-08-04
- Inventor: Tatsumi FUJIYOSHI
- Applicant: Alps Alpine Co., Ltd.
- Applicant Address: JP Tokyo
- Assignee: Alps Alpine Co., Ltd.
- Current Assignee: Alps Alpine Co., Ltd.
- Current Assignee Address: JP Tokyo
- Priority: JP2019-202625 20191107
- Main IPC: G01R27/26
- IPC: G01R27/26 ; G06F3/044 ; H03K17/955

Abstract:
A capacitance detection device detecting a capacitance between a detection electrode and a detection target close to the detection electrode has: a first voltage output circuit that outputs a first alternating current voltage to be supplied to a shield electrode placed close to the detection electrode; a second voltage output circuit that outputs a second alternating current voltage with substantially the same frequency as the first alternating current voltage; and an operational amplifier that amplifies the difference in voltage between an inverting input terminal connected to the detection electrode and a non-inverting input terminal to which the second alternating current voltage is applied, and outputs the amplified difference in voltage. With the detection target close to the detection electrode, the second voltage output circuit outputs the second alternating current voltage adjusted so that an output voltage from the operational amplifier has a smaller amplitude than the first alternating current voltage.
Public/Granted literature
- US12019109B2 Capacitance detection device and capacitance detection method Public/Granted day:2024-06-25
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