Touch controller, touch system, and method for detecting a touch screen

• US 9,715,310 B2
• Filed: 12/23/2014
• Issued: 07/25/2017
• Est. Priority Date: 03/19/2008
• Status: Active Grant

• Current Assignee: eGalax_eMPIA Technology Inc.
• Original Assignee: eGalax_eMPIA Technology Inc.
• Inventors: Tang, Chi-Hao, Chang, Chin-Fu
• Primary Examiner(s): PHAM, VIET DAVID
• Application Number:
  US14/580,812
• Publication Number:
  US 20150109250A1
• Time in Patent Office: 945 Days
• Field of Search: 345173
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/04162 for exchanging data with external devices, e.g. smart pens, via the digitiser sensing hardware
• 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 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• 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

The invention discloses a touch controller, a touch system, and a method for detecting a touch screen. At first, a full screen driven detection is performed on a touch screen to determine whether at least one external object touches or approaches the touch screen. Then, if the full screen driven detection represents that no external object touches or approaches the touch screen, an updating determination is performed to determine whether a plurality of reference values are updated during a predetermined updating period of time. If the updating determination represents that the reference values are not updated during the predetermined updating period of time, the reference values will be updated based on a first 2D sensing information.

Claims

1. A method for detecting a touch screen, comprising:

continuously performing a plurality of full screen driven detections on a touch screen to determine whether at least one external object touches or approaches the touch screen, wherein the touch screen comprises a plurality of first conductive strips and a plurality of second conductive strips, and each of the plurality of full screen driven detections comprises;

simultaneously providing a driving signal to all of the first conductive strips; and

detecting mutual capacitive signals of all of the second conductive strips to generate a 1D (one-dimensional) sensing information based on the signals of all of the second conductive strips while all of the first conductive strips are provided with the driving signal;

performing an updating determination to determine whether a plurality of reference values are updated during a predetermined updating period of time if each of the plurality of full screen driven detections represents that no external object touches or approaches the touch screen; and

updating the reference values based on a first 2D (two-dimensional) sensing information if the updating determination represents that the reference values are not updated during the predetermined updating period of time.

2. The method of claim 1, wherein the full screen driven detection is repeated after the reference values are updated.

3. The method of claim 1, wherein the full screen driven detection is repeated if the updating determination represents that the reference values are updated during the predetermined updating period of time.

4. The method of claim 1, further comprising:

performing a 2D mutual capacitive detection to obtain a second 2D sensing information and determining a location of the at least one external conductive object based on the second 2D sensing information if the full screen driven detection represents that at least one external object touches or approaches the touch screen; and

repeating the full screen driven detection.

5. The method of claim 1, wherein if the full screen driven detection represents that no external object touches or approaches the touch screen, the first 2D sensing information is obtained by performing a 2D mutual capacitive detection, comprising:

sequentially providing a driving signal to one or more different conductive strips in the first conductive strips;

each time one or more different conductive strips in the first conductive strips being provided with the driving signal, detecting the signals of all of the second conductive strips to obtain a 1D sensing information corresponding to the one or more first conductive strips being provided with the driving signal generated based on the mutual capacitive signals of all of the second conductive strips; and

combining each 1D sensing information corresponding to the one or more first conductive strips being provided with the driving signal to generate a 2D sensing information.

6. A touch controller, executing the following operations:

continuously performing a plurality of full screen driven detections on a touch screen to determine whether at least one external object touches or approaches the touch screen, wherein the touch screen comprises a plurality of first conductive strips and a plurality of second conductive strips, and each of the plurality of full screen driven detections comprises;

simultaneously providing a driving signal to all of the first conductive strips; and

detecting mutual capacitive signals of all of the second conductive strips to generate a 1D (one-dimensional) sensing information based on the signals of all of the second conductive strips while all of the first conductive strips are provided with the driving signal;

performing an updating determination to determine whether a plurality of reference values are updated during a predetermined updating period of time if each of the plurality of full screen driven detections represents that no external object touches or approaches the touch screen; and

updating the reference values based on a first 2D (two-dimensional) sensing information if the updating determination represents that the reference values are not updated during the predetermined updating period of time.

7. The touch controller of claim 6, wherein the full screen driven detection is repeated after the reference values are updated.

8. The touch controller of claim 6, wherein the full screen driven detection is repeated if the updating determination represents that the reference values are updated during the predetermined updating period of time.

9. The touch controller of claim 6, further executing the following operations:

performing a 2D mutual capacitive detection to obtain a second 2D sensing information and determining a location of the at least one external conductive object based on the second 2D sensing information if the full screen driven detection represents that at least one external object touches or approaches the touch screen; and

repeating the full screen driven detection.

10. The touch controller of claim 6, wherein if the full screen driven detection represents that no external object touches or approaches the touch screen, the first 2D sensing information is obtained by performing a 2D mutual capacitive detection, comprising:

sequentially providing a driving signal to one or more different conductive strips in the first conductive strips;

each time one or more different conductive strips in the first conductive strips being provided with the driving signal, detecting the signals of all of the second conductive strips to obtain a 1D sensing information corresponding to the one or more first conductive strips being provided with the driving signal generated based on the mutual capacitive signals of all of the second conductive strips; and

combining each 1D sensing information corresponding to the one or more first conductive strips being provided with the driving signal to generate a 2D sensing information.

11. A touch system, comprising:

a touch screen; and

a touch controller, executing the following operations;

continuously performing a plurality of full screen driven detection on a touch screen to determine whether at least one external object touches or approaches the touch screen, wherein the touch screen comprises a plurality of first conductive strips and a plurality of second conductive strips, and each of the plurality of full screen driven detections comprises;

simultaneously providing a driving signal to all of the first conductive strips; and

detecting mutual capacitive signals of all of the second conductive strips to generate a 1D (one-dimensional) sensing information based on the signals of all of the second conductive strips while all of the first conductive strips are provided with the driving signal;

performing an updating determination to determine whether a plurality of reference values are updated during a predetermined updating period of time if each of the plurality of full screen; and

updating the reference values based on a first 2D (two-dimensional) sensing information if the updating determination represents that the reference values are not updated during the predetermined updating period of time.

12. The touch system of claim 11, wherein the full screen driven detection is repeated after the reference values are updated.

13. The touch system of claim 11, wherein the full screen driven detection is repeated if the updating determination represents that the reference values are updated during the predetermined updating period of time.

14. The touch system of claim 11, wherein the touch controller further executes the following operations:

performing a 2D mutual capacitive detection to obtain a second 2D sensing information and determining a location of the at least one external conductive object based on the second 2D sensing information if the full screen driven detection represents that at least one external object touches or approaches the touch screen; and

repeating the full screen driven detection.

15. The touch system of claim 11, wherein if the full screen driven detection represents that no external object touches or approaches the touch screen, the first 2D sensing information is obtained by performing a 2D mutual capacitive detection, comprising:

sequentially providing a driving signal to one or more different conductive strips in the first conductive strips;

each time one or more different conductive strips in the first conductive strips being provided with the driving signal, detecting the signals of all of the second conductive strips to obtain a 1D sensing information corresponding to the one or more first conductive strips being provided with the driving signal generated based on the mutual capacitive signals of all of the second conductive strips; and

combining each 1D sensing information corresponding to the one or more first conductive strips being provided with the driving signal to generate a 2D sensing information.