CAPACITANCE SENSING APPARATUS AND METHOD, AND TOUCH SCREEN APPARATUS

• US 20140009431A1
• Filed: 09/10/2012
• Published: 01/09/2014
• Est. Priority Date: 07/09/2012
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Kwon, Yong Il, Hong, Kyung Hee, Lee, Sang Ho, Park, Tah Joon
• Granted Patent: US 8,976,149 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• 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 3/04182 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

There is provided a capacitance sensing apparatus including: a driving circuit unit sequentially applying a driving signal to each of a plurality of first electrodes; a sensing circuit unit including a first integrating circuit detecting a first change in capacitance generated in a plurality of second electrodes by the driving signal and a second integrating circuit connected to another first electrode adjacent to the first electrode to which the driving signal is applied; and an operating unit connected to the sensing circuit unit to determine a touch input, wherein the second integrating circuit detects a second change in capacitance generated due to noise in the another first electrode, and the operating unit determines the touch input based on the first and second changes in capacitance.

Claims

1. A capacitance sensing apparatus comprising:

a driving circuit unit sequentially applying a driving signal to each of a plurality of first electrodes;

a sensing circuit unit including a first integrating circuit detecting a first change in capacitance generated in a plurality of second electrodes by the driving signal and a second integrating circuit connected to another first electrode adjacent to the first electrode to which the driving signal is applied; and

an operating unit connected to the sensing circuit unit to determine a touch input,

wherein the second integrating circuit detects a second change in capacitance generated due to noise in the another first electrode, and

the operating unit determines the touch input based on the first and second changes in capacitance.

2. The capacitance sensing apparatus of claim 1, wherein the first integrating circuit includes a variable capacitor and a non-inverting amplifier, the variable capacitor being controlled to allow an output value of the non-inverting amplifier to be 0 when noise is not introduced thereto.

3. The capacitance sensing apparatus of claim 1, wherein the second integrating circuit inverts and integrates the second change in capacitance.

4. The capacitance sensing apparatus of claim 1, wherein the sensing circuit unit further includes a subtractor calculating a voltage difference between an output voltage of the first integrating circuit and an output voltage of the second integrating circuit.

5. The capacitance sensing apparatus of claim 1, further comprising a controlling unit performing a control operation such that the driving signal is sequentially applied to the plurality of first electrodes and the second integrating circuit is connected to the another first electrode adjacent to the first electrode to which the driving signal is applied.

6. The capacitance sensing apparatus of claim 4, wherein the operating unit determines the touch input based on an output signal of the subtractor.

7. A capacitance sensing method comprising:

applying a driving signal to at least one of a plurality of first electrodes;

generating a first output voltage from a first change in capacitance generated in a plurality of second electrodes by the driving signal;

generating a second output voltage from a second change in capacitance generated due to noise in another first electrode adjacent to the first electrode to which the driving signal is applied;

calculating a voltage difference between the first and second output voltages; and

determining a touch input based on the voltage difference.

8. The capacitance sensing method of claim 7, wherein the generating of the first output voltage is performed by non-inverting and integrating the first change in capacitance.

9. The capacitance sensing method of claim 7, wherein the generating of the first output voltage further includes controlling a variable capacitor to allow the first output voltage to be 0 when noise is not introduced thereto.

10. The capacitance sensing method of claim 7, wherein the generating of the second output voltage is performed by non-inverting and integrating the second change in capacitance.

11. A touch screen apparatus comprising:

a panel unit including a plurality of driving electrodes and a plurality of sensing electrodes;

a driving circuit unit applying a driving signal to each of the plurality of driving electrodes;

a sensing circuit unit sensing changes in capacitance generated in intersections between the driving electrodes to which the driving signal is applied and the plurality of sensing electrodes; and

a controlling unit controlling operations of the driving circuit unit and the sensing circuit unit,

wherein the sensing circuit unit includes first and second integrating circuits, the first integrating circuit detecting a first change in capacitance generated in the sensing electrodes by the driving signal and the second integrating circuit detecting a second change in capacitance generated due to noise in another driving electrode adjacent to the driving electrode to which the driving signal is applied.

12. The touch screen apparatus of claim 11, wherein the first integrating circuit includes a variable capacitor and a non-inverting amplifier, the variable capacitor being controlled to allow an output value of the non-inverting amplifier to be 0.

13. The touch screen apparatus of claim 11, wherein the sensing circuit unit calculates a voltage difference between an output voltage of the first integrating circuit and an output voltage of the second integrating circuit to generate an output signal to be input to the controlling unit.

14. The touch screen apparatus of claim 11, wherein the controlling unit performs a control operation so that the second integrating circuit is connected to the another driving electrode adjacent to the driving electrode to which the driving signal is applied.