Touch sensing apparatus and method thereof

• US 8,970,543 B2
• Filed: 01/27/2012
• Issued: 03/03/2015
• Est. Priority Date: 11/21/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Kwon, Yong II, Lee, Sang Ho, Hong, Gyung Hee, Park, Tah Joon
• Primary Examiner(s): Chow, Van
• Application Number:
  US13/359,610
• Publication Number:
  US 20130127773A1
• Time in Patent Office: 1,131 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 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• 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 are provided a touch sensing apparatus and a touch sensing method. The touch sensing apparatus includes a driving circuit unit applying a driving signal to at least one of a plurality of first electrodes; a sensing circuit unit generating an analog signal by detecting variations in capacitance in second electrodes intersecting the at least one of first electrodes to which the driving signal is applied; and a signal converting unit converting the analog signal into a digital signal, wherein the driving circuit unit controls a frequency of the driving signal according to electric noise and determines a level of the driving signal according to a dynamic range of the signal converting unit.

Claims

1. A touch sensing apparatus, comprising:

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

a sensing circuit unit generating an analog signal by detecting variations in capacitance in second electrodes intersecting the at least one of the first electrodes to which the driving signal is applied;

a signal converting unit converting the analog signal into a digital signal; and

a comparison circuit unit comparing a level of the analog signal input into the signal converting unit with an upper limit signal level and a lower limit signal level to determine a dynamic range of the signal converting unit, generating a comparison result signal to decrease a level of the driving signal if the level of the analog signal is higher than the upper limit signal level of the dynamic range of the signal converting unit, and generating the comparison result signal to increase the level of the driving signal if the level of the analog signal is lower than the lower limit signal level of the dynamic range of the signal converting unit, and

the driving circuit unit controlling a frequency of the driving signal according to electric noise and controlling the level of the driving signal according to the comparison result signal from the comparison circuit unit.

2. The touch sensing appartus of claim 1, wherein the driving circuit unit applies the driving signal to the plurlaity of first electrodes as a current signal and controls a level of the current signal according to the electric noise.

3. The touch sensing appartus of claim 2, wherein the driving circuit unit includes a curent mirror circuit for controlling the level of the current signal.

4. The touch sensing appartus of claim 1, wherein the driving circuit unit controls at least one of the frequency of the driving signal and the level of the driving signal accoridng to output of the comparision circuit unit.

5. The touch sensing appartus of claim 1, wherein the sensing circuit unit detects variations in mutual-capacitance in the second electrodes intersecting the at least one of first electrodes to which the driving signal is applied.

6. The touch sensing appartus of claim 1, wherein the driving circuit unit, the sensing circuit unit, and the signal converting unit are configured as an integrated circuit.

7. A touch sensing method, comprising:

changing a frequency of a driving signal according to a noise generated outside;

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

generating an analog signal by detecting variations in capacitance in second electrodes intersecting the at least one of the first electrodes to which the driving signal is applied; and

converting the analog signal into a digital signal,

wherein a level of the driving signal is controlled by comparing a level of the analog signal with a dynamic range of the converted analog signal that is converted into the digital signal.

8. The touch sensing method of claim 7, wherien the converting of the analog signal into the digital signal includes setting parameters accroding to the frequency of the driving signal and the level of the driving signal.

9. The touch sensing method of claim 7, further comprising determining a touch by using the digital signal.

10. The touch sensing method of claim 7, wherien the geneating of the analog signal includes detecting variations in mutual-capacitance in the second electrodes intersecting the at least one of first electrodes to which the driving signal is applied.

11. The touch sensing method of claim 7, wherein the dynamic range is a range between an upper limit signal level and a lower limit signal level of the analog signal.