US 2011/0254571 A1 · POSITION DETECTOR

Abstract

To enable position or distance of sensing target making approach, etc. to the range of sensing area to be detected securely with simple configuration at low cost and improve latitude of designing, position detector includes capacitance sensor unit and detecting circuit unit. Capacitance sensor unit includes first and second sensing electrodes and dielectric material therebetween. Dielectric material has range L of sensing area defined on its sensing surface. Detecting circuit unit includes selector switches SWA and SWB, capacitance sensing circuits, A/D converters, and arithmetic processing circuit. Arithmetic processing circuit judges and detects the position of sensing target in range L of sensing area based on detected values of capacitances C1 and C2 sensed by first and second sensing electrodes under switching control on selector switches SWA and SWB.

Claims20

Dependent claims

A position detector, comprising:

a dielectric material having a sensing surface defining a range of a sensing area;
a plurality of sensing electrodes which are provided in the vicinity of ends of the dielectric material, and which sense a capacitance between themselves and a sensing target;
a detecting circuit which detects capacitance values that are based on sensing signals from the plurality of sensing electrodes;
a plurality of selector switches which are capable of switching the plurality of sensing electrodes respectively between connection to the detecting circuit and connection to a ground potential or a certain fixed potential;
and
judging/detecting means which judges and detects at least one of a position of the sensing target on the sensing surface and a distance of the sensing target from the sensing surface based on detection results from the detecting circuit.

3 more elements

A position detector, comprising:

a dielectric material having a sensing surface defining a range of a sensing area;
a plurality of sensing electrodes which are provided in the vicinity of ends of the dielectric material and which sense a capacitance between themselves and a sensing target;
a detecting circuit which detects capacitance values which are based on sensing signals from the sensing electrodes;
a dummy detecting circuit which supplies a same potential as that of any of the sensing electrodes that is connected to the detecting circuit to the other sensing electrode/s;
a plurality of selector switches which are capable of switching the plurality of sensing electrodes respectively between connection to the detecting circuit and connection to the dummy detecting circuit;
and
judging/detecting means which judges and detects at least one of a position of the sensing target on the sensing surface and a distance of the sensing target from the sensing surface based on detection results from the detecting circuit.

4 more elements

Dependencies are inferred from the claim text.

Position detector

Life of this patent

Position detector

Life of this patent

Abstract

Claims20