TOUCH SCREEN, TOUCH SYSTEM AND METHOD FOR POSITIONING A TOUCH OBJECT IN TOUCH SYSTEM

• US 20120176345A1
• Filed: 09/29/2010
• Published: 07/12/2012
• Est. Priority Date: 09/30/2009
• Status: Active Grant

• Current Assignee: Sansheng Intellectual Education Technology Co., Ltd.
• Original Assignee: Sansheng Intellectual Education Technology Co., Ltd.
• Inventors: Ye, Xinlin, Liu, Jianjun, Liu, Xinbin, Wu, Zhenyu, Zhang, Haibing, Wang, Yuhui, Hao, Haidong, Tang, Haibo
• Granted Patent: US 8,928,608 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/042 by opto-electronic 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 3/043 using propagating acoustic waves
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A touch screen, a touch system and a method for positioning a touch object in a touch system are disclosed. The touch screen comprises an infrared pair tube array, wherein said infrared pair tube array is disposed on an edge of said touch screen. By introducing the infrared pair tube array, the touch screen of the present invention eliminates invalid touch areas in the existing touch screen and avoids false touch points in multipoint positioning.

Claims

1. A touch screen, comprising:

a main touch sensing apparatus adapted to sense positions of a touch point at different directions and output sensed signals; and

an infrared pair tube array disposed on an edge of said touch screen, adapted to sense the position of the touch point at array extending direction and output a sensed signal;

wherein the sensed signals outputted by said main touch sensing apparatus and the sense signal outputted by said infrared pair tube array are used to determine real position information of the touch point.

2. The touch screen according to claim 1, wherein said main touch sensing apparatus is one of a resistive touch sensing apparatus, a surface capacitive touch sensing apparatus, a projected capacitive touch sensing apparatus, an optical touch sensing apparatus utilizing an image sensor, a surface acoustic wave touch sensing apparatus and a bending wave touch sensing apparatus.

3. The touch screen according to claim 1, wherein said main touch sensing apparatus comprises:

two image sensors disposed on an edge of said touch screen, adapted to acquire image information of a touch object; and

a light source disposed on an edge of said touch screen, adapted to provide light to said two image sensors;

wherein said infrared pair tube array is disposed on two opposite edges or the same edge of said touch screen.

4. The touch screen according to claim 1, further comprising:

a frame and a retro-reflection strip, wherein said two image sensors are mounted on two adjacent corners of said frame, each of the light sources is mounted near the respective image sensors;

said retro-reflection strip is mounted on three edges of said frame; and

said infrared pair tube array is disposed on the same edge or two opposite edges of said frame.

5. The touch screen according to claim 4, wherein said infrared pair tube array is disposed on the same edge of said frame, infrared emitting tubes and infrared receiving tubes in said infrared pair tube array are arranged to overlap each other or parallel to each other, and light shading plates are disposed between said infrared emitting tubes and said infrared receiving tubes.

7. The touch screen according to claim 4, wherein said infrared pair tube array comprises a plurality of infrared pair tubes, wherein each of said infrared pair tubes includes an infrared emitting tube and an infrared receiving tube adjacent to the infrared emitting tube, and a light-limiting hole is disposed in the front of each of said infrared pair tubes.

8. The touch screen according to claim 4, wherein said light source is adjacent to said image sensor, light shading plates are disposed between said image sensors and said light sources, said light shading plates extending along camera direction of said image sensors.

9. The touch screen according to claim 4, wherein said two image sensors and said infrared pair tube array are disposed on the edge on which said retro-reflection strip is not mounted.

10. The touch screen according to claim 4, wherein said infrared pair tube array comprises an infrared emitting tube group and an infrared receiving tube group, wherein said infrared emitting tube group and said infrared receiving tube group are respectively disposed on the edge on which said retro-reflection strip is not mounted and its opposite edge.

11. A touch system, comprising:

a touch screen according to any one of claims 1 to 4;

a first signal processing module connected to the main touch sensing apparatus in said touch screen, adapted to process the sensed signals from said main touch sensing apparatus to determine preliminary two-dimensional position information of a touch point on said touch screen and transmit it to a main controller;

a second signal processing module connected to the infrared pair tube array in said touch screen, adapted to determine one-dimensional position information of said touch point at the array extending direction of said infrared pair tube array according to number information of the infrared receiving tube which does not receive the infrared rays and transmit it to the main controller; and

the main controller connected to said first signal processing module and said second signal processing module, adapted to determine a real position of said touch point according to the preliminary two-dimensional position information from said first signal processing module and the one-dimensional position information from said second signal processing module.

6. (canceled)

12. A method for positioning a touch point in a touch system, comprising:

acquiring preliminary two-dimensional position information of a touch point, and at the same time acquiring one-dimensional position information of the touch point at array extending direction using an infrared pair tube array; and

determining real position information of said touch point according to said two-dimensional position information and said one-dimensional position the receiving status information.

16. The method according to claim 12, wherein apparatus for acquiring preliminary two-dimensional position information of a touch point includes two image sensors mounted on two adjacent corners of a touch screen, a light source and a retro-reflection strip;

and the step of acquiring two-dimensional position information comprises;

acquiring coordinate values N1, N2 of a centre of an image formed on the two image sensors by two shades formed by said touch point on said retro-reflection strip;

according to said coordinate values N1, N2, calculating the values of t1 and t2 corresponding to N1, N2 respectively by using t=(N−

0.5V)/(0.5V),tε

[−

1,1], wherein V is the total pixel value of any line of a charge-coupled device of each of said two image sensors;

according to the calculated values of t1 and t2, calculating the angles θ

1 and θ

2 respectively formed by the lines between the center of the two shades and the center of the images formed on said two image sensors and the common edge provided with said two image sensors using

17. The method according to claim 16, wherein the one-dimensional position information of said touch point at array extending direction acquired by said infrared pair tube array is the position information of infrared tubes which do not receive the infrared rays at the array extending direction.

18. The method according to claim 16, wherein the one-dimensional position information is horizontal ordinate X1,

according to horizontal ordinate x in said two-dimensional position information (x, y) and said horizontal ordinate x1, calculating the horizontal ordinate x_final in the real position information of said touch point by using x_final=xr+x1(1−

r), wherein r is a function of y, r=f(y), and

19. The method according to claim 18, wherein, when

20. The method according to claim 19, wherein k_x=1.

13-15. -15. (canceled)

21. A touch system, comprising:

a main touch positioning system adapted to position a touch point to acquire preliminary two-dimensional position information of said touch point;

one-dimensional position information positioning system including an infrared pair tube array adapted to determine one-dimensional position information of said touch point; and

a processing unit connected to said main touch positioning system and said one-dimensional position information positioning system, adapted to determine real position information of said touch point according to the preliminary two-dimensional position information of said touch point from said main touch positioning system and the one-dimensional position information of said touch point from said one-dimensional position information positioning system.

22. The touch system according to claim 21, wherein said main touch positioning system is one of a resistive touch positioning system, a surface capacitive touch positioning system, a projected capacitive touch positioning system, an optical touch positioning system, a surface acoustic wave touch positioning system and a bending wave touch positioning system.

23. The touch system according to claim 21, wherein said infrared pair tube array comprises an infrared emitting tube group and an infrared receiving tube group, wherein said infrared emitting tube group and said infrared receiving tube group are respectively disposed on two opposite edges of said main touch positioning system.

24. The touch system according to claim 23, wherein said processing unit further include a control unit adapted to control the infrared emitting tubes in said infrared emitting tube group to illuminate simultaneously.

25-27. -27. (canceled)