Method for detecting touch panel noise and performing signal control and associated controller

• US 9,582,109 B2
• Filed: 09/30/2013
• Issued: 02/28/2017
• Est. Priority Date: 09/30/2013
• Status: Active Grant

• Current Assignee: Himax Technologies Ltd. (Himax Technologies Incorporated)
• Original Assignee: Himax Technologies Ltd. (Himax Technologies Incorporated)
• Inventors: Liu, Li-Lin, Chang, Chung-Wen, Tai, Shen-Feng, Liu, Jui-Min
• Primary Examiner(s): Ghebretinsae, Temesghen
• Assistant Examiner(s): Karki, Paras D
• Application Number:
  US14/042,697
• Publication Number:
  US 20150091814A1
• Time in Patent Office: 1,247 Days
• Field of Search: 345/173
• US Class Current: 1/1
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/044 by capacitive means

Abstract

A method for detecting noise of a touch panel and performing signal control is provided, where the method may determine how many cycles of frame data are influenced by noise, may determine whether the frame data is influenced by noise by determining whether a number of cycles influenced by noise is greater than a first threshold value or not, and may determine whether a number of continuous frame data determined to be influenced by noise is greater than a second threshold value to generate a determination result. Finally, the method may determine whether to adjust a frequency of the transmitting signals according to the determination result.

Claims

1. A method for detecting noise of a touch panel and performing signal control, wherein the touch panel comprises a plurality of sensing lines and a plurality of driving lines, and the sensing lines and the driving lines are intersected, and the method comprises:

a first step sequentially transmitting a plurality of transmitting signals to the driving lines of the touch panel, respectively;

a second step for receiving data of a plurality of cycles, where data of one cycle is digital data of a plurality of receiving signals from the sensing lines when one transmitting signal is enabled and inputted into its corresponding driving line, and the data of the plurality of cycles form one frame data of the touch panel;

a third step for determining how many cycles are influenced by noise for each cycle by determining a maximum value and a minimum value of the received data among the cycle; and

determining whether the cycle is influenced by noise according to the maximum value and the minimum value of the cycle;

a fourth step for determining whether the frame data is influenced by noise by determining whether a number of cycles influenced by noise is greater than a first threshold value or not, where when the number of cycles influenced by noise is greater than the first threshold value, the frame data is determined to be influenced by noise;

a fifth step for repeating the first to fourth steps to determine whether a number of continuous frame data determined to be influenced by noise is greater than a second threshold value to generate a determination result; and

a sixth step for adjusting a frequency of the transmitting signals according to the determination result;

wherein the first step to the sixth step are performed sequentially.

2. The method of claim 1, wherein in the third step, determining whether the cycle is influenced by noise according to the maximum value and the minimum value of the cycle comprises:

determining whether the minimum value is greater than a third threshold value or not;

determining whether a difference value between the maximum value and the minimum value is less than a fourth threshold value or not;

when the minimum value is greater than the third threshold value and the difference value is less than the fourth threshold value, determining that the cycle is influenced by noise; and

when the minimum value is not greater than the third threshold value or the difference value is not less than the fourth threshold value, determining that the cycle is not influenced by noise.

3. The method of claim 1, wherein the second threshold value is equal to 1 or 2.

4. A controller of a touch panel, wherein the touch panel comprises a plurality of sensing lines and a plurality of driving lines, and the sensing lines and the driving lines are intersected, and the controller comprises

a micro-processor;

and

a program code stored in a storage device of the controller;

when the program code is executed by the micro-processor, the program code executes the following steps;

a first step for sequentially transmitting a plurality of transmitting signals to the driving lines of the touch panel, respectively;

a second step for receiving data of a plurality of cycles, where data of one cycle is digital data of a plurality of receiving signals from the sensing lines when one transmitting signal is enabled and inputted into its corresponding driving line, and the data of the plurality of cycles form one frame data of the touch panel;

a third step for determining how many cycles are influenced by noise for each cycle by

determining a maximum value and a minimum value of the received data among the cycle; and

determining whether the cycle is influenced by noise according to the maximum value and the minimum value of the cycle;

a fourth step for determining whether the frame data is influenced by noise by determining whether a number of cycles influenced by noise is greater than a first threshold value or not, where when the number of cycles influenced by noise is greater than the first threshold value, the frame data is determined to be influenced by noise;

a fifth step for repeating the first to fourth steps to determine whether a number of continuous frame data determined to be influenced by noise is greater than a second threshold value to generate a determination result; and

a sixth step for adjusting a frequency of the transmitting signals according to the determination result;

wherein the first step to the sixth step are performed sequentially.

5. The controller of claim 4, wherein in the third step, determining whether the cycle is influenced by noise according to the maximum value and the minimum value of the cycle comprises:

determining whether the minimum value is greater than a third threshold value or not;

determining whether a difference value between the maximum value and the minimum value is less than a fourth threshold value or not;

when the minimum value is greater than the third threshold value and the difference value is less than the fourth threshold value, determining that the cycle is influenced by noise; and

when the minimum value is not greater than the third threshold value or the difference value is not less than the fourth threshold value, determining that the cycle is not influenced by noise.

6. The controller of claim 4, wherein the second threshold value is equal to 1 or 2.