Touch panel and image display device including the same

• US 9,619,095 B2
• Filed: 07/28/2015
• Issued: 04/11/2017
• Est. Priority Date: 06/21/2012
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Kim, Sung-Chul, Lee, Jung-Han
• Primary Examiner(s): CHOWDHURY, AFROZA Y
• Application Number:
  US14/811,007
• Publication Number:
  US 20160011695A1
• Time in Patent Office: 623 Days
• 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 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G09G 2354/00 Aspects of interface with display user
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 2217/960715 Rc-timing; e.g. measurement of variation of charge time or discharge time of the sensor

Abstract

A self capacitance type touch panel includes a touch driver including a plurality of touch ICs; and a touch unit including a plurality of touch groups that are controlled by the plurality of touch ICs, respectively, wherein each of the plurality of touch groups includes a plurality of pattern electrodes, and some touch ICs selected from the plurality of touch ICs apply sensing voltages to respective corresponding touch groups at a same timing.

Claims

1. A touch driver circuit for driving a self capacitance type touch panel including a plurality of touch groups, each of the touch groups including a plurality of pattern electrodes, the touch driver circuit comprising:

a plurality of touch ICs (integrated circuits) to control the plurality of touch groups of the self capacitance type touch panel, wherein;

selected ones of the touch ICs apply touch sensing voltages to respective corresponding touch groups at a same timing, the plurality of touch ICs that apply the sensing voltages to the respective corresponding touch groups at the same timing controlling the respective corresponding touch groups using the touch sensing voltages adjusted to have the same phase and stored in advance, and

the plurality of touch ICs determine presence of a touch input on the touch panel based on a change to the touch sensing voltages responsive to the touch input.

2. The touch driver circuit of claim 1, wherein each touch IC comprises:

a memory unit to store a reference sensing time period for each pattern electrode, taken for the touch sensing voltage to be charged or discharged to be a sensed voltage before the touch input is generated; and

a comparator to compare a changed sensing time period received from the memory unit when the touch input has been generated, to the reference sensing time period, and to determine whether or not the touch input has occurred according to results of the comparison.

3. The touch driver circuit of claim 1, further comprising a voltage switching unit to transfer the touch sensing voltage or a common voltage to the pattern electrodes.

4. The touch driver circuit of claim 1, wherein the touch driver circuit further comprises a touch group switching unit to switch connections of output channels of each of the touch ICs in order to change touch groups that are controlled by the touch IC.

5. A method of driving a self capacitance type touch panel including a plurality of touch groups, each of the touch groups including a plurality of pattern electrodes, the method comprising:

applying touch sensing voltages to respective corresponding touch groups of the self capacitance type touch panel at a same timing using selected ones of a plurality of touch ICs to control the plurality of touch groups, the touch sensing voltages adjusted to have the same phase and stored in advance; and

determining presence of a touch input on the touch panel based on a change to the touch sensing voltages responsive to the touch input.

6. The method of claim 5, wherein determining presence of the touch input comprises:

storing a reference sensing time period for each pattern electrode taken for the touch sensing voltage to be charged or discharged to be a sensed voltage before the touch input is generated; and

comparing a changed sensing time period when the touch input has been generated to the reference sensing time period to determine whether or not the touch input has occurred according to results of the comparison.

7. The method of claim 5, further comprising transferring the touch sensing voltage or a common voltage to the pattern electrodes using a voltage switching unit.

8. The method of claim 5, further comprising switching connections of output channels of each of the touch ICs, using a touch group switching unit, to change touch groups that are controlled by the touch IC.