COORDINATE POSITION DETECTION APPARATUS

• US 20140125628A1
• Filed: 06/04/2012
• Published: 05/08/2014
• Est. Priority Date: 06/08/2011
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Yoshida, Takehisa, Shimoshikiryoh, Fumikazu
• Granted Patent: US 9,235,305 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer

Abstract

A configuration of a coordinate position detection apparatus is provided that provides a sufficient sensitivity even in the case of a larger device. A coordinate position detection apparatus (100) includes: a first sensor electrode (X_i); a first capacitance detector (21) connected with the first sensor electrode (X_i) and including an integration circuit; a second sensor electrode (Y_j); a second capacitance detector (22) connected with the second sensor electrode (Y_j) and including an integration circuit; a coordinate computing unit (25); and a coordinate pointing device (30). In this coordinate position detection apparatus (100), when it is in a first input mode where the coordinate pointing device (30) inputs a coordinate position, a plurality of first and second capacitance detectors (21) and (22) are configured to detect a signal provided by the coordinate pointing device (30), and the coordinate pointing device (30) performs charging and the plurality of first and second capacitance detectors (21) and (22) perform integration during a unit detection period to measure capacitances. Based on the capacitances, the coordinate computing unit (25) determines the coordinate position.

Claims

1. A coordinate position detection apparatus, comprising:

a first sensor electrode;

a first capacitance detector connected with the first sensor electrode and including an integration circuit;

a second sensor electrode;

a second capacitance detector connected with the second sensor electrode and including an integration circuit;

a coordinate computing unit; and

a coordinate pointing device,

wherein, when the apparatus is in a first input mode where the coordinate pointing device inputs a coordinate position,

a plurality of first and second capacitance detectors are configured to detect a signal provided by the coordinate pointing device,

the coordinate pointing device performs charging and the plurality of first and second capacitance detectors perform integration during a unit detection period to measure capacitances, and

based on the capacitances, the coordinate computing unit determines the coordinate position.

2. The coordinate position detection apparatus according to claim 1, further comprising:

a selector switch provided between the second sensor electrode and the second capacitance detector; and

an oscillator circuit connected with one switching connection of the selector switch,

wherein, when the apparatus is in a second input mode where a coordinate position is input by a coordinate pointing means other than the coordinate pointing device, the selector switch causes the second sensor electrode to be connected with the oscillator circuit, a plurality of first capacitance detectors detect a signal provided by the oscillator circuit, the oscillator circuit performs charging and the plurality of first capacitance detectors perform integration during the unit detection period to measure capacitances, and based on the capacitances, the coordinate computing unit determines the coordinate position.

3. The coordinate position detection apparatus according to claim 2, further comprising an input mode switching unit configured to switch the apparatus between the first input mode and the second input mode successively during the unit detection period.

4. The coordinate position detection apparatus according to claim 2, wherein the coordinate computing unit determines the coordinate position based on signals provided by a plurality of oscillator circuits in a time division manner when the apparatus is in the second input mode.

5. The coordinate position detection apparatus according to claim 2, wherein the coordinate computing unit determines the coordinate position based on signals perpendicular to each other provided by a plurality of oscillator circuits when the apparatus is in the second input mode.

6. The coordinate position detection apparatus according to claim 5, wherein the signals perpendicular to each other provided by the plurality of oscillator circuits include bit strings with +1 and −

1.

7. The coordinate position detection apparatus according to claim 1, wherein the coordinate computing unit determines the coordinate position of each of a plurality of coordinate pointing devices based on signals provided by the plurality of coordinate pointing devices in a time division manner when the apparatus is in the first input mode.

8. The coordinate position detection apparatus according to claim 1, wherein the coordinate computing unit determines the coordinate position of each of a plurality of coordinate pointing devices based on signals perpendicular to each other provided by the plurality of coordinate pointing devices when the apparatus is in the first input mode.

9. The coordinate position detection apparatus according to claim 8, wherein the signals perpendicular to each other provided by the plurality of coordinate pointing devices include bit strings with +1 and −

1.