Method of controlling noise processing circuit of touch panel and related noise processing apparatus

• US 9,041,673 B2
• Filed: 03/14/2013
• Issued: 05/26/2015
• Est. Priority Date: 04/17/2012
• Status: Active Grant

• Current Assignee: Raydium Semiconductor Corporation
• Original Assignee: Raydium Semiconductor Corporation
• Inventors: Chou, Shih-Tzung, Chuang, Hsu-Ming
• Primary Examiner(s): Agustin, Peter Vincent
• Application Number:
  US13/802,811
• Publication Number:
  US 20130271398A1
• Time in Patent Office: 803 Days
• Field of Search: None
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment

Abstract

The present invention provides a method of controlling a noise processing circuit of a touch panel and a related noise signal processing apparatus. At first, the present invention detects whether the touch panel is interfered with by noise. Then, according to whether the noise interferes with the touch panel, the noise processing circuit is controlled to be activated or not activated. Therefore, the noise processing circuit can be turned off if it is unnecessary, thereby to reduce the workload due to the noise processing.

Claims

1. A method for controlling a noise processing circuit of a touch panel, the touch panel having a plurality of first sensing axes on a first dimension and a plurality of second sensing axes on a second dimension, the method comprising:

selecting at least one reference axis from the plurality of first sensing axes;

sensing the least one reference axis to generate a first sensed output when the plurality of first sensing axes and the plurality of second sensing axes are not driven;

generating a noise detection result at least according to the first sensed output; and

controlling the noise processing circuit according to the noise detection result.

2. The method of claim 1, wherein the step of controlling the noise processing circuit according to the noise detection result comprises:

activating the noise processing circuit to process noises when the noise detection result indicates the touch panel is interfered with by the noises.

3. The method of claim 1, wherein:

the step of selecting the at least one reference axis from the plurality of first sensing axes comprises;

selecting a plurality of reference axes from the plurality of first sensing axes; and

the step of sensing the least one reference axis to generate the first sensed output comprises;

sensing the plurality of reference axes to generate the first sensed output.

4. The method of claim 1, further comprising:

selecting at least one detection axis from the plurality of first sensing axes; and

sensing the at least one detection axis to generate a second sensed output;

wherein the step of generating the noise detection result at least according to the first sensed output comprising;

generating the noise detection result according to the first sensed output and the second sensed output.

5. The method of claim 1, wherein the step of sensing the at least one reference axis to generate the first sensed output comprises:

sensing the at least one reference axis to generate the first sensed output;

and the method further comprises;

selecting at least one detection axis from the plurality of the second sensing axes; and

sensing the at least one detection axis to generate a second sensed output; and

the step of generating the noise detection result at least according to the first sensed output comprising;

generating the noise detection result according to the first sensed output and the second sensed output.

6. The method of claim 1, further comprising:

selecting at least one reference axis from the plurality of second sensing axes;

wherein the step of generating the first sensed output comprises;

sensing the at least one reference axis selected from the plurality of first sensing axes and the at least one reference axis selected from the plurality of second sensing axes to generate the first sensed output.

7. A noise processing apparatus for a touch panel, the touch panel having a plurality of first sensing axes on a first dimension and a plurality of second sensing axes on a second dimension, the noise processing apparatus comprising:

a driving circuit;

a multiplexer, coupled to the plurality of the first sensing axes and the plurality of the second sensing axes, for generating at least one first sensed output;

a configuration circuit, coupled to the driving circuit and the multiplexer, for configuring the driving circuit not to drive the plurality of first sensing axes and the plurality of second sensing axes, and configuring the multiplexer to select at least one reference axis from the plurality of first sensing axes, wherein the multiplexer generates the first sensed output according to a sensed result of the at least one reference axis;

a determination circuit, coupled to the multiplexer, for generating a noise detection result at least according to the first sensed output; and

a noise processing circuit, coupled to the determination circuit, for operating according to the noise detection result.

8. The noise processing apparatus of claim 7, wherein the noise processing circuit is activated to process noises when the noise detection result indicates the touch panel is interfered with by the noises.

9. The noise processing apparatus of claim 7, wherein the configuration circuit configures the multiplexer to select a plurality of reference axes from the plurality of first sensing axes and to generate the first sensed output according to sensed results of the plurality of reference axes.

10. The noise processing apparatus of claim 7, wherein:

the configuration circuit configures the multiplexer to select at least one detection axis from the plurality of first sensing axes, wherein the multiplexer generates a second sensed output according to a sensed result of the at least one detection axis; and

the determination circuit generates the noise detection result according to the first sensed output and the second sensed output.

11. The noise processing apparatus of claim 7, wherein:

the configuration circuit configures the multiplexer to select at least one detection axis from the plurality of the second sensing axes, wherein the multiplexer generates a second sensed output according to a sensed result of the at least one detection axis; and

the determination circuit generates the noise detection result according to the first sensed output and the second sensed output.

12. The noise processing apparatus of claim 7, wherein:

the configuration circuit configures the multiplexer to select at least one reference axis from the plurality of the second sensing axes, wherein the multiplexer generates the first sensed output according to sensed results of the at least one reference axis selected from the plurality of first sensing axes and the at least one reference axis selected from the plurality of second sensing axes; and

the determination circuit generates the noise detection result according to the first sensed output.