METHOD AND APPARATUS FOR IMPROVING TOUCH SENSITIVITY OF TOUCH SCREEN PANEL

• US 20130113753A1
• Filed: 11/02/2012
• Published: 05/09/2013
• Est. Priority Date: 11/09/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: LEE, Heonseok, HEO, Hoondo, PARK, Jongdae
• Granted Patent: US 9,348,471 B2
• Time in Patent Office: 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 3/0418 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 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A method and an apparatus for improving touch sensitivity of a capacitive type touch screen panel are provided. In the method, the apparatus sequentially drives a plurality of transmitting channels of the touch screen panel using a predetermined scan frequency. The apparatus determines a sequential touch count by simultaneously scanning a plurality of receiving channels of the touch screen panel wherein the sequential touch count is the number of sequentially touched receiving channels. Also, the apparatus specifies a scan unit to be used for dividing the plurality of receiving channels into groups on the basis of the sequential touch count and for sequentially scanning the groups of the receiving channels. The apparatus determines a touch coordinate by sequentially scanning the plurality of receiving channels using the specified scan unit.

Claims

1. A method for improving touch sensitivity in an electronic device having a capacitive type touch screen panel, the method comprising:

sequentially driving a plurality of transmitting channels of the touch screen panel using a predetermined scan frequency;

determining a sequential touch count by simultaneously scanning a plurality of receiving channels of the touch screen panel wherein the sequential touch count is the number of sequentially touched receiving channels;

specifying a scan unit to be used for dividing the plurality of receiving channels into groups on the basis of the sequential touch count and for sequentially scanning the groups of the receiving channels; and

determining a touch coordinate by sequentially scanning the plurality of receiving channels using the specified scan unit.

2. The method of claim 1, wherein the specifying of the scan unit includes categorizing the plurality of receiving channels in an amount corresponding to the sequential touch count.

3. The method of claim 2, wherein the categorizing of the plurality of receiving channels includes categorizing adjacent receiving channels into different groups.

4. The method of claim 1, further comprising:

newly specifying the scan frequency based on the sequential touch count; and

sequentially driving the plurality of transmitting channels using the newly specified scan frequency.

5. The method of claim 4, wherein the newly specifying of the scan frequency includes multiplying the predetermined scan frequency by the sequential touch count.

6. The method of claim 1, wherein the determining of the sequential touch count includes:

when a multi-touch is detected from two or more regions on the touch screen panel, selecting a greatest region in area among the regions; and

determining the sequential touch count at the selected region.

7. The method of claim 1, wherein the specifying of the scan unit includes specifying the scan unit on the basis of the sequential touch count when the sequential touch count is lower than a predetermined threshold value.

8. The method of claim 7, wherein the threshold value is used to determine whether the sequentially touched receiving channels are touched by a finger.

9. An apparatus for improving touch sensitivity, the apparatus comprising:

a capacitive type touch screen panel having a plurality of transmitting and receiving channels; and

a control unit configured to sequentially drive the plurality of transmitting channels using a predetermined scan frequency, to determine a sequential touch count by simultaneously scanning the plurality of receiving channels wherein the sequential touch count is the number of sequentially touched receiving channels, to specify a scan unit on the basis of the sequential touch count, and to determine a touch coordinate by sequentially scanning the plurality of receiving channels using the specified scan unit.

10. The apparatus of claim 9, wherein the control unit is further configured to categorize the plurality of receiving channels into groups in an amount corresponding to the sequential touch count, and to determine the touch coordinate by sequentially scanning the groups of the receiving channels.

11. The apparatus of claim 10, wherein adjacent receiving channels are categorized into different groups.

12. The apparatus of claim 9, wherein the control unit is further configured to newly specify the scan frequency based on the sequential touch count, and to sequentially drive the plurality of transmitting channels using the newly specified scan frequency.

13. The apparatus of claim 9, wherein the control unit is further configured to, when a multi-touch is detected from two or more regions on the touch screen panel, select a greatest region in area among the regions, and to determine the sequential touch count at the selected region.

14. The apparatus of claim 9, wherein the control unit is further configured to, when the sequential touch count is lower than a predetermined threshold value, determine that the sequentially touched receiving channels are touched by a finger, and to determine the touch coordinate.

15. The apparatus of claim 9, further comprising a touch sensing unit configured to detect a variation in capacitance in the touch screen panel.

16. The apparatus of claim 15, wherein the touch sensing unit comprises a plurality of sensing blocks corresponding to the plurality of receiving channels.

17. The apparatus of claim 16, wherein each of the plurality of sensing blocks comprises:

an amplifier configured to receive and amplify a signal from a corresponding receiving channel;

a capacitor configured to receive and store a capacitance from the corresponding receiving channel;

a switch, controlled by the control unit, configured to switch a connection between the amplifier and the capacitor; and

a delay unit configured to delay an output of the capacitor.

18. The apparatus of claim 17, further comprising an Analog to Digital Conversion (ADC) unit configured to receive the delayed output from the delay unit and to output a digital signal to the control unit.