Capacitive input device having two detection modes
First and second substrates are disposed to face each other and allowed to approach each other. A plurality of first electrodes are formed on the first substrate. A plurality of second electrodes are formed on the second substrate and face the respective first electrodes. A facing electrode pair is constituted by each of the first electrodes and a corresponding one of the second electrodes. A switching unit causes each of the first electrodes and each of the second electrodes to be connected to a driving unit or a detecting unit and switches between a first detection state in which a distance change between each of the first electrodes and a corresponding one of the second electrodes is detected and a second detection state in which the coordinates of a position that an operating body approaches or touches are determined in accordance with detection outputs from the facing electrode pairs.
1. A capacitive input device comprising:
a first substrate;
a second substrate facing the first substrate, the first substrate being approachable to the second substrate in accordance with an input operation of an operating body;
a plurality of first electrodes formed on an upper surface of the first substrate;
a plurality of second electrodes formed on a lower surface of the second substrate, each second electrode facing corresponding one of the plurality of first electrodes with the first and second substrate interposed therebetween, thereby forming a plurality of electrode pairs, each electrode pair including a first electrode and a corresponding second electrode; and
a controller including:
a driving circuit;
a detecting circuit; and
a switching unit configured to selectively connect each of the first electrodes and each of the second electrodes to the driving circuit or the detecting circuit, thereby providing a first detection mode and a second detection mode,
wherein the first detection mode detects a change in a distance between each of the first electrodes and a corresponding one of the second electrodes, and the second detection mode determines a position which the operating body approaches or touches in accordance with detection outputs from the electrode pairs.
2. The capacitive input device according to claim 1 ,
wherein, in the first detection mode, the switching unit connects the plurality of first electrodes to one of the driving circuit and the detecting circuit, and the plurality of second electrodes to the other of the driving circuit and the detecting circuit, and
wherein, in the second detection mode, the switching unit selectively connects each electrode pair either to the driving circuit or to the detecting circuit.
3. The capacitive input device according to claim 2 ,
wherein, in the first detection mode, the switching unit simultaneously connects all of the first electrodes of the electrode pairs to one of the driving circuit and the detecting circuit, and all of the second electrodes of the electrode pairs to the other of the driving circuit the detecting circuit.
4. The capacitive input device according to claim 3 ,
wherein, in the second detection mode, the switching unit connects one of the electrode pairs to the driving circuit, and remaining electrode pairs to the detecting circuit, and
wherein the position is determined in accordance with a change in mutual capacitance between the one electrode pair connected to the driving circuit and the remaining electrode pairs connected to the detecting circuit.
5. The capacitive input device according to claim 4 ,
wherein, in the second detection mode, the switching unit sequentially selects the one electrode pair to be connected to the driving unit from among the electrode pairs.
6. The capacitive input device according to claim 3 ,
wherein, in the second detection mode, the switching unit connects at least one of the electrode pairs to the driving circuit and the detecting circuit, thereby determining a position which the operating body approaches or touches in accordance with a change in self-capacitance of the at least one electrode pair detected by the detecting circuit.
7. The capacitive input device according to claim 2 ,
wherein, in the first detection mode, the switching unit individually connects, in each electrode pair, the first electrode to one of the driving circuit and the detecting circuit and the second electrode to the other of the driving circuit and the detecting circuit.
8. The capacitive input device according to claim 7 ,
wherein, in the second detection mode, the switching unit connects one of the electrode pairs to the driving circuit, and remaining electrode pairs to the detecting circuit, and
wherein the position is determined in accordance with a change in mutual capacitance between the one electrode pair connected to the driving circuit and the remaining electrode pairs connected to the detecting circuit.
9. The capacitive input device according to claim 8 ,
wherein, in the second detection mode, the switching unit sequentially selects the one electrode pair to be connected to the driving unit from among the electrode pairs.
10. The capacitive input device according to claim 7 ,
wherein, in the second detection mode, the switching unit connects at least one of the electrode pairs to the driving circuit and the detecting circuit, thereby determining a position which the operating body approaches or touches in accordance with a change in self-capacitance of the at least one electrode pair detected by the detecting circuit.
11. The capacitive input device according to claim 2 ,
wherein, in the second detection mode, the switching unit connects one of the electrode pairs to the driving circuit, and remaining electrode pairs to the detecting circuit, and
wherein the position is determined in accordance with a change in mutual capacitance between the one electrode pair connected to the driving circuit and the remaining electrode pairs connected to the detecting circuit.
12. The capacitive input device according to claim 11 ,
wherein, in the second detection mode, the switching unit sequentially selects the one electrode pair to be connected to the driving unit from among the electrode pairs.
13. The capacitive input device according to claim 2 ,
wherein, in the second detection mode, the switching unit connects at least one of the electrode pairs to the driving circuit and the detecting circuit, thereby determining a position which the operating body approaches or touches in accordance with a change in self-capacitance of the at least one electrode pair detected by the detecting circuit.
14. The capacitive input device according to claim 1 ,
wherein, in the second detection mode, the switching unit connects one of the electrode pairs to the driving circuit, and remaining electrode pairs to the detecting circuit, and
wherein the position is determined in accordance with a change in mutual capacitance between the one electrode pair connected to the driving circuit and the remaining electrode pairs connected to the detecting circuit.
15. The capacitive input device according to claim 14 ,
wherein, in the second detection mode, the switching unit sequentially selects the one electrode pair to be connected to the driving unit from among the electrode pairs.
16. The capacitive input device according to claim 1 ,
wherein, in the second detection model, the switching unit connects at least one of the electrode pairs to the driving circuit and the detecting circuit, thereby determining a position which the operating body approaches or touches in accordance with a change in self-capacitance of the at least one electrode pair detected by the detecting circuit.
17. The capacitive input device according to claim 1 ,
wherein the first electrode and the second electrode in each electrode pair have a respective facing surface of a same planar shape.
18. The capacitive input device according to claim 1 , further comprising:
an elastic member interposed between the first substrate and the second substrate.