Capacitance distribution detection method, capacitance distribution detection circuit, touch sensor system, and information input/output device

• US 9,454,271 B2
• Filed: 04/04/2012
• Issued: 09/27/2016
• Est. Priority Date: 06/27/2011
• 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: Miyamoto, Masayuki, Iizuka, Kunihiko
• Primary Examiner(s): Sternbane, Larry
• Assistant Examiner(s): Ritchie, Darlene M
• Application Number:
  US14/129,068
• Publication Number:
  US 20140139483A1
• Time in Patent Office: 1,637 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/04182 Filtering of noise external to the device and not generated by digitiser components
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A capacitance distribution detection circuit (2) includes a multiplexer (4), a driver (5), and a sense amplifier (6), and the multiplexer (4) switches states between a first connection state in which first signal lines (HL1 to HLM) are connected to the driver (5) and second signal lines (VL1 to VLM) are connected to the sense amplifier (6), and a second connection state in which the first signal lines (HL1 to HLM) are connected to the sense amplifier (6) and the second signal lines (VL1 to VLM) are connected to the driver (5).

Claims

1. A method of detecting capacitance distribution, to detect a distribution of capacitance of a plurality of capacitors that are each formed on intersections of a plurality of first signal lines with a plurality of second signal lines, the first signal lines and the second signal lines being included in a touch panel,

the method comprising:

driving the first signal lines to output from the second signal lines first electric charges that correspond to the capacitors;

detecting, based on the first electric charges, a first capacitance distribution on the touch panel, the first capacitance distribution representing a distribution of capacitances of a plurality of capacitors, the capacitances each being formed at an intersection of a corresponding one of the plurality of first signal lines and a corresponding one of the plurality of second signal lines;

driving the second signal lines to output from the first signal lines second electric charges that correspond to the capacitors;

detecting, based on the second electric charges, a second capacitance distribution on the touch panel, the second capacitance distribution representing a distribution of capacitances of a plurality of capacitors, the capacitance each being formed at an intersection of a corresponding one of the plurality of first signal lines and a corresponding one of the plurality of second signal lines; and

detecting, based on at least one of the first capacitance distribution and the second capacitance distribution, the distribution of the capacitance of the capacitors,

wherein the plurality of first signal lines, the plurality of second signal lines, and the plurality of capacitors constitute a touch panel, wherein the touch panel allows for a hand that holds a pen for input to be simultaneously placed thereon, thereby defining an input area circumscribed by a hand placing region, wherein an operation is carried out on the first and second capacitance distributions, respectively, to eliminate the effect of phantom noise generated in said area.

2. A capacitance distribution detection circuit that detects a distribution of capacitance of a plurality of capacitors that are each formed on intersections of a plurality of first signal lines with a plurality of second signal lines, the first signal lines and the second signal lines being included in a touch panel,

the capacitance distribution detection circuit comprising:

a multiplexer connected to the plurality of first signal lines and the plurality of second signal lines;

a driver connected to the multiplexer;

a sense amplifier connected to the multiplexer; and

a detecting section for detecting the distribution of the capacitance of the capacitors on the touch panel, based on a signal from the sense amplifier,

the multiplexer switching a connection state between a first connection state and a second connection state, the first connection state being a state in which the first signal lines are connected to the driver and the second signal lines are connected to the sense amplifier so that the driver drives the first signal lines by use of driving signals and then responses of the second signal lines to the driving signals are supplied to the detecting section via the sense amplifier, and the second connection state being a state in which the first signal lines are connected to the sense amplifier and the second signal lines are connected to the driver so that the driver drives the second signal lines by use of the driving signals and then responses of the first signal lines to the driving signals are supplied to the detecting section via the sense amplifier,

the detecting section being configured to (i) detect, based on the responses of the second signal lines, a first signal line capacitance distribution generated as a result of the first signal lines being driven, the first signal line capacitance distribution representing a distribution of capacitances of a plurality of capacitors, the capacitances each being formed at an intersection of a corresponding one of the plurality of first signal lines and a corresponding one of the plurality of second signal lines, (ii) detect, based on the responses of the first signal lines, a second signal line capacitance distribution generated as a result of the second signal lines being driven, the second signal line capacitance distribution representing a distribution of capacitances of a plurality of capacitors, the capacitances each being formed at an intersection of a corresponding one of the plurality of first signal lines and a corresponding one of the plurality of second signal lines, and (iii) detect, based on at least one of the first signal line capacitance distribution and the second signal line capacitance distribution, the distribution of the capacitance of the capacitors,

wherein the plurality of first signal lines, the plurality of second signal lines, and the plurality of capacitors constitute a touch panel, wherein the touch panel allows for a hand that holds a pen for input to be simultaneously placed thereon, thereby defining an input area circumscribed by a hand placing region, wherein an operation is carried out on the first and second signal line capacitance distributions, respectively, to eliminate the effect of phantom noise generated in said area.

3. The capacitance distribution detection circuit according to claim 2, wherein the plurality of first signal lines, the plurality of second signal lines, and the plurality of capacitors constitute a touch panel, the touch panel being of a size allowing for a hand that holds a pen for input to be placed thereon.

4. A touch sensor system, comprising:

a capacitance distribution detection circuit recited in claim 2; and

a touch panel including the plurality of first signal lines, the plurality of second signal lines, and the plurality of capacitors.

5. The touch sensor system according to claim 4, wherein the capacitance distribution detection circuit detects a distribution of capacitance in accordance with an input with use of a pen.

6. An information input/output device, comprising:

a touch sensor system recited in claim 4; and

a display panel (i) being superposed on a touch panel provided in the touch sensor system or (ii) having the touch panel be built therein.

7. The information input/output device according to claim 6, wherein the capacitance distribution detection circuit detects a distribution of capacitance in accordance with an input with use of a pen.

8. A capacitance distribution detection circuit that detects a distribution of capacitance of a plurality of capacitors that are each formed on intersections of a plurality of first signal lines with a plurality of second signal lines, the first signal lines and the second signal lines being included in a touch panel,

the capacitance distribution detection circuit comprising:

a first multiplexer connected to the first signal lines;

a first driver connected to the first multiplexer;

a first sense amplifier connected to the first multiplexer;

a second multiplexer connected to the second signal lines;

a second driver connected to the second multiplexer;

a second sense amplifier connected to the second multiplexer;

a detecting section for detecting the distribution of the capacitance of the capacitors on the touch panel, based on respective signals from the first sense amplifier and from the second sense amplifier; and

a control circuit that controls the first multiplexer and the second multiplexer so that a connection state is switchable between a first connection state and a second connection state, the first connection state being a state in which the first signal lines are connected to the first driver and the second signal lines are connected to the second sense amplifier so that the first driver drives the first signal lines by use of driving signals and then responses of the second signal lines to the driving signals are supplied to the detecting section via the second sense amplifier, and the second connection state being a state in which the first signal lines are connected to the first sense amplifier and the second signal lines are connected to the second driver so that the second driver drives the second signal lines by use of the driving signals and then responses of the first signal lines to the driving signals are supplied to the detecting section via the first sense amplifier,

the detecting section being configured to (i) detect, based on the responses of the second signal lines, a first signal line capacitance distribution generated as a result of the first signal lines being driven, (ii) detect, based on the responses of the first signal lines, a second signal line capacitance distribution generated as a result of the second signal lines being driven, and (iii) detect, based on at least one of the first signal line capacitance distribution and the second signal line capacitance distribution, the distribution of the capacitance of the capacitors.

9. The capacitance distribution detection circuit according to claim 8, wherein the plurality of first signal lines, the plurality of second signal lines, and the plurality of capacitors constitute a touch panel, the touch panel being of a size allowing for a hand that holds a pen for input to be placed thereon.

10. A touch sensor system, comprising:

a capacitance distribution detection circuit recited in claim 8; and

a touch panel including the plurality of first signal lines, the plurality of second signal lines, and the plurality of capacitors.

11. The touch sensor system according to claim 10, wherein the capacitance distribution detection circuit detects a distribution of capacitance in accordance with an input with use of a pen.

12. An information input/output device, comprising:

a touch sensor system recited in claim 10; and

a display panel (i) being superposed on a touch panel provided in the touch sensor system or (ii) having the touch panel be built therein.

13. The information input/output device according to claim 12, wherein the capacitance distribution detection circuit detects a distribution of capacitance in accordance with an input with use of a pen.