MULTI-TOUCH POSITION TRACKING APPARATUS AND INTERACTIVE SYSTEM AND IMAGE PROCESSING METHOD USING THE SAME

• US 20090267919A1
• Filed: 06/18/2008
• Published: 10/29/2009
• Est. Priority Date: 04/25/2008
• Status: Abandoned Application

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: WANG, PO-HUNG, CHAO, SHIH-PIN, LIOU, TUNG-FA, TANG, CHENG-YUAN, CHEN, CHIA-CHEN, HUANG, CHING-LUNG
• Application Number:
  US12/141,248
• Publication Number:
  US 20090267919A1
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 2203/04108 Touchless 2D- 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 without distance measurement in the Z direction
• CPC Class Codes: G06F 2203/04109 FTIR in optical digitiser, i.e. touch detection by frustrating the total internal reflection within an optical waveguide due to changes of optical properties or deformation at the touch location
• 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 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

The present invention provides a multi-touch position tracking technique and an interactive system and a multi-touch interactive image processing method using the same. In the present invention, a light guide element is designed to comprise frustrating structures to frustrate total internal reflection (TIR) so that the light beam therein can be dispersed to form a dispersed optical field distribution. The dispersed optical field is used to respond a physical relation between an object and the light guide element.

Claims

1. A multi-touch position tracking apparatus, comprising:

a light source;

a light guide element capable of receiving an incoming optical field from the light source and enabling the incoming optical field to go out from a side surface of the light guide element to form a dispersed optical field;

a sensor module capable of sensing the light from the dispersed optical field being dispersed or reflected to acquire a sensed image; and

a processing unit capable of determining a physical relation between at least an object and the light guide element corresponding to the sensed image.

2. The multi-touch position tracking apparatus as recited in claim 1, wherein the light guide element comprises a dispersing structure on the side surface.

3. The multi-touch position tracking apparatus as recited in claim 1, wherein the light guide element further comprises:

a light guide plate capable of receiving the incoming optical field; and

a light guide sheet connected to one side surface of the light guide plate;

wherein the refractive index of the light guide sheet is larger than the refractive index of the light guide plate, and the light guide sheet comprises a dispersing structure to enable the incoming optical field to go out to form the dispersed optical field.

4. The multi-touch position tracking apparatus as recited in claim 2, wherein the light source is an infrared light emitting diode (LED), an infrared laser or a non-visible light source.

5. The multi-touch position tracking apparatus as recited in claim 1, wherein the sensor module further comprises:

an image sensor; and

a lens set capable of forming the sensed image on the image sensor.

6. The multi-touch position tracking apparatus as recited in claim 5, further comprising an optical filter disposed between the lens set and the image sensor or between the lens set and the light guide element.

7. The multi-touch position tracking apparatus as recited in claim 1, wherein the physical relation is a position or a pressure applied on the light guide element.

8. A multi-touch interactive system, comprising:

a light source;

a light guide element capable of receiving an incoming optical field from the light source and enabling the incoming optical field to go out from a side surface of the light guide element to form a dispersed optical field;

a sensor module capable of sensing the light from the dispersed optical field being dispersed or reflected to acquire a sensed image;

a processing unit capable of determining a physical relation between at least an object and the light guide element corresponding to the sensed image and generating a control signal corresponding to the physical relation or the variation of the physical relation; and

a display device capable of generating an interactive image according to the control signal.

9. The multi-touch interactive system as recited in claim 8, wherein the light guide element is a light guide plate comprising a dispersing structure on the side surface wherefrom the incoming optical field goes out.

10. The multi-touch interactive system as recited in claim 8, wherein the light guide element further comprises:

a light guide plate capable of receiving the incoming optical field; and

a light guide sheet connected to one side surface of the light guide plate;

wherein the light guide sheet comprises a dispersing structure to enable the incoming optical field to go out to form the dispersed optical field.

11. The multi-touch interactive system as recited in claim 8, wherein the light source is an infrared light emitting diode (LED), an infrared laser or a non-visible light source.

12. The multi-touch interactive system as recited in claim 8, wherein the sensor module further comprises:

an image sensor; and

a lens set capable of forming the sensed image on the image sensor.

13. The multi-touch interactive system as recited in claim 12, further comprising an optical filter disposed between the lens set and the image sensor or between the lens set and the light guide element.

14. The multi-touch interactive system as recited in claim 8, wherein the display device and the light guide element are coupled.

15. The multi-touch interactive system as recited in claim 8, wherein the display device is a rear-projection display device or a liquid-crystal display device.

16. The multi-touch interactive system as recited in claim 8, wherein the physical relation is a position or a pressure applied on the light guide element.

17. A multi-touch interactive image processing method, comprising steps of:

(a) providing a light guide element and a sensor module, the light guide element capable of receiving an incoming optical field and enabling the incoming optical field to go out therefrom to form a dispersed optical field being incident on at least an object so that a dispersed/reflected light beam from the object is received by the sensor module to form a sensed image;

(b) filtering the sensed image according to at least a threshold value to form at least a filtered image;

(c) analyzing the filtered image to acquire at least a group of characteristic values corresponding to the filtered image and the object;

(d) determining a physical relation between the object and the light guide element according to the characteristic values; and

(e) tracking the variation of the physical relation.

18. The multi-touch interactive image processing method as recited in claim 17, wherein the physical relation is a position or a pressure applied on the light guide element.

19. The multi-touch interactive image processing method as recited in claim 17, wherein the characteristic values represent luminance.

20. The multi-touch interactive image processing method as recited in claim 17, wherein step (b) further comprises steps of:

(b1) determining a first threshold value and a second threshold value;

(b2) filtering the sensed image according to the first threshold value to form a first filtered image; and

(b3) filtering the first filtered image according to the second threshold value to form a second filtered image.

21. The multi-touch interactive image processing method as recited in claim 20, wherein the first filtered image corresponds to at least a non-contact object and the second filtered image corresponds to at least a contact object.

22. The multi-touch interactive image processing method as recited in claim 17, further comprising between step (d) and step (e) steps of:

(d1) determining if there is any signal missing from the group of characteristic values and determining the variation between a previous physical relation and a next physical relation if there is no signal missing; and

(d2) updating the threshold value if there is the variation so as to form an updated filtered image and repeating from step (a) to step (d).

23. The multi-touch interactive image processing method as recited in claim 17, further comprising steps of:

(f) issuing a control signal to an application program according to the variation of the physical relation; and

(d2) interacting with the object according to the control signal.