Touch screen, touch system and method for positioning a touch object in touch system

• US 8,928,608 B2
• Filed: 09/29/2010
• Issued: 01/06/2015
• 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
• Primary Examiner(s): Zhou, Hong
• Application Number:
  US13/497,337
• Publication Number:
  US 20120176345A1
• Time in Patent Office: 1,560 Days
• Field of Search: 345173-177, 178 1801- 1901
• US Class Current: 345/173
• 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 system, comprising:

a touch panel;

a main touch sensing apparatus adapted to sense a position of a touch point on the touch panel by a touch object at different directions and output a first sensed signal; and

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

a first signal processing module connected to the main touch sensing apparatus, adapted to process the first sensed signal from the main touch sensing apparatus to determine preliminary two-dimensional position information of the touch point on the touch panel;

a second signal processing module connected to the infrared pair tube array, adapted to determine one-dimensional position information of the touch point on the touch panel at the extending direction of the infrared pair tube array according to the second sensed signal; and

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

2. The touch system according to claim 1, wherein the 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 system according to claim 1, wherein the main touch sensing apparatus comprises:

two image sensors disposed on an edge of the touch panel, adapted to acquire image information of the touch object on the touch panel; and

a light source disposed on the edge of the touch panel, adapted to provide light to the two image sensors;

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

4. The touch screen according to claim 3, wherein the main touch sensing apparatus further comprises:

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

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

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

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

6. The touch system according to claim 4, wherein the infrared pair tube array comprises a plurality of infrared pair tubes, wherein each of the 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 the infrared pair tubes.

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

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

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

10. The touch system according to claim 1, wherein the second signal processing module determines number information of an infrared receiving tube of the infrared pair tube array which does not receive infrared rays as the one-dimensional position information of the touch point at the extending direction of the infrared pair tube array.

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

acquiring preliminary two-dimensional position information of the touch point;

acquiring, by means of an infrared pair tube array, one-dimensional position information of the touch point at an extending direction of the infrared pair tube array; and

determining the position of the touch point by using one-dimensional position information and the preliminary two-dimensional position information.

12. The method according to claim 11, wherein apparatus for acquiring preliminary two-dimensional position information of the touch point includes two image sensors mounted on two adjacent corners of a touch panel, 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 the touch point on the retro-reflection strip;

according to the 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 the 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 the two image sensors and the common edge provided with the two image sensors using

13. The method according to claim 12, wherein position information of an infrared receiving tube in the infrared pair tube array which does not receive infrared rays is acquired as the one-dimensional position information of the touch point.

14. The method according to claim 12, wherein the one-dimensional position information is horizontal ordinate X1,

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

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

15. The method according to claim 14, wherein, when

16. The method according to claim 15, wherein k_x=1.

17. A touch system, comprising:

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

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

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

18. The touch system according to claim 17, wherein the 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.

19. The touch system according to claim 17, wherein the infrared pair tube array comprises an infrared emitting tube group and an infrared receiving tube group, wherein the infrared emitting tube group and the infrared receiving tube group are respectively disposed on two opposite edges of the main touch positioning system.

20. The touch system according to claim 19, wherein the processing unit further include a control unit adapted to control the infrared emitting tubes in the infrared emitting tube group to illuminate simultaneously.

21. The touch system according to claim 17, wherein the one-dimensional position information positioning system determines number information of an infrared receiving tube of the infrared pair tube array which does not receive infrared rays as the one-dimensional position information of the touch point.