Multi-touch system and driving method thereof

• US 8,436,832 B2
• Filed: 12/30/2008
• Issued: 05/07/2013
• Est. Priority Date: 04/08/2008
• Status: Expired due to Fees

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Sohn, Min Ho, Choi, Jong Seong, Jang, Hyung Uk, Bae, Sang Hyuck, Yu, Byung Chun
• Primary Examiner(s): Shalwala, Bipin
• Assistant Examiner(s): SPAR, ILANA L
• Application Number:
  US12/318,535
• Publication Number:
  US 20090251425A1
• Time in Patent Office: 1,589 Days
• Field of Search: 345/156, 345/157, 345/173, 345/175
• US Class Current: 345/175
• CPC Class Codes: G06F 2203/04808 Several contacts: gestures triggering a specific function, e.g. scrolling, zooming, right-click, when the user establishes several contacts with the surface simultaneously; e.g. using several fingers or a combination of fingers and pen
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0428 by sensing at the edges of the touch surface the interruption of optical paths, e.g. an illumination plane, parallel to the touch surface which may be virtual sensing beam interruptions in a planar beam grid of an optical touch-screen G06F3/0421
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures

Abstract

Provided are a multi-touch system and a driving method thereof. The method includes, extracting using a digital processor a touch frequency and at least one angle associated with at least one touch from image information captured by each of at least two cameras, selecting a touch mode on the basis of sum value of the touch frequencies extracted from the image information captured by the cameras, and performing a touch function corresponding to the selected touch mode using a user interface.

Claims

1. A method for driving a multi-touch system, the method comprising:

capturing image information including fingers touch points of a user touched on a panel by each of at least two camera for a set of frames;

extracting using a digital processor both touch frequency and angle information of the user'"'"'s touch points from the image information;

summing the touch frequency from each camera without calculating positional information using a controller, wherein the touch frequency has a threshold of at least 2;

selecting a touch mode on the basis of only the summed value of the touch frequencies using the controller;

generating a control signal corresponding to the selected touch mode using the controller; and

performing a touch function in response to the control signal using a user interface,

wherein the image information comprises a touch frequency of at least one touch and at least one angle information.

2. The method according to claim 1, wherein the touch frequency is a count of concurrent touches in the image information captured by one of the cameras.

3. The method according to claim 1, wherein each camera generates the image information for each image frame in a set of frames for a display having a predetermined number.

4. The method according to claim 1, wherein the touch mode is selected when a sum value of the touch frequency of the at least one touch in the generated image information for the cameras is included within a range of sum values of the frequency of touches that correspond to the touch mode, for between 50 and 100% of the frames in the set of frames.

5. The method according to claim 1, wherein the touch function simulates pressing of a mouse left button.

6. The method according to claim 1, wherein the touch function simulates pressing of a mouse right button.

7. The method according to claim 1, wherein the touch function simulates pressing of a mouse scroll button.

8. The method according to claim 1, wherein the touch function performs toggling the state of a virtual keyboard between an off state and an on state.

9. The method according to claim 5, further comprising computing a coordinate of a touch point using the angles extracted from the image information of each of the cameras, the simulated pressing of the mouse left button being performed at the touch point.

10. The method according to claim 6, further comprising:

averaging the angles of a user'"'"'s touch points extracted from the image information of each of the cameras to compute an average angle for each camera; and

computing a coordinate of a new touch point using the average angles,

wherein simulating the pressing of the mouse right button is performed at the new touch point.

11. The method according to claim 7, further comprising:

averaging the angles of the user'"'"'s touch points extracted from the image information of each of the cameras to compute average angles; and

computing a coordinate of a new touch point using the average angles,

wherein an image displayed on a panel is moved from the new touch point along the user'"'"'s scroll in a specific direction after simulating the pressing of the mouse scroll button.

12. The method according to claim 8, further comprising:

averaging the angles extracted from the each image information to compute average angles; and

computing a coordinate of a new touch point using the average angles,

wherein the virtual keyboard is displayed at the new touch point used as a reference.

13. The method according to claim 12, wherein the virtual keyboard that is being displayed is removed by another touch of the user.

14. A multi-touch system comprising:

at least two cameras, each capturing image information including fingers touch points of a user touched on a panel for a set of frames;

a digital processor calculating both touch frequency and angle information of the user'"'"'s touch points from each image information without calculating positional information;

a controller summing the touch frequency from each image information, selecting a touch mode in response to only the summed value of the touch frequency and generating a control signal corresponding to the selected touch mode, wherein the touch frequency has a threshold of at least 2;

an operating system generating a command corresponding to the control signal to provide the command to the user interface; and

a user interface performing a touch function in response to the command,

wherein the image information comprises a touch frequency of at least one touch and at least one angle information.

15. The system according to claim 14, wherein the touch recognition unit includes at least two cameras.

16. The system according to claim 15, wherein the at least two cameras are disposed at corner regions of a panel.

17. The system according to claim 14, wherein the touch recognition unit includes a plurality of infrared sensors and a plurality of photo sensors.

18. The system according to claim 14, wherein the controller averages the angles extracted from the each image information to compute an average angle for reach image information, and computes a coordinate of a new touch point using the computed average angles to provide the new touch point to the user interface, and the user interface performs the touch function using the new touch point as a reference.