POSITIONING MODULE, OPTICAL TOUCH SYSTEM AND METHOD OF CALCULATING A COORDINATE OF A TOUCH MEDIUM

• US 20140146016A1
• Filed: 03/21/2013
• Published: 05/29/2014
• Est. Priority Date: 11/29/2012
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Lu, Chun-Yi, Cheng, Hsin-Chi, Lin, Yu-Chia, Lin, Chun-Sheng
• Granted Patent: US 9,134,855 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

A positioning module of calculating a coordinate of a touch medium is disclosed in the present invention. The positioning module includes at least one image detecting unit, a first light source, a second light source and a processor. The image detecting unit includes a lateral side and an upper side. The image detecting unit captures an image reflected from a reflection component. The first light source is disposed on the lateral side and outputs a first beam. The second light source is disposed on the upper side and outputs a second beam. The processor is electrically connected to the image detecting unit. The processor determines a touch status of the touch medium according to a first image generated by the first beam, and further determines a touch coordinate of the touch medium according to a second image generated by the second beam.

Claims

1. A positioning module for calculating coordinates of a touch medium, the positioning module comprising:

at least one image detecting unit, the image detecting unit comprising a lateral side and an upper side;

a first light source disposed on the lateral side for emitting a first beam;

a second light source disposed on the upper side for emitting a second beam; and

a processor electrically connected to the image detecting unit, the processor determining a touch status of the touch medium according to a first image generated by the first beam, and further determining a touch position of the touch medium according to a second image generated by the second beam.

2. The positioning module of claim 1, wherein the first beam is reflected by a reflection component to project the first image on the image detecting unit, the second beam is reflected by the reflection component to project the second image on the image detecting unit.

3. The positioning module of claim 2, wherein the image detecting unit detects a first dark area generated on the reflection component because a part of the first beam is shadowed by the touch medium, and determines the touch status according to an intensity of the first dark area on the first image.

4. The positioning module of claim 3, wherein the image detecting unit determines that the touch medium contacts a panel when the intensity of the first dark area on the first image is lower than a threshold value.

5. The positioning module of claim 2, wherein the image detecting unit detects a second dark area generated on the reflection component because a part of the second beam is shadowed by the touch medium, and determines the touch position according to a position of the second dark area on the second image.

6. The positioning module of claim 1, wherein a distance between the first light source and a surface of a panel is substantially smaller than a distance between the second light source and the surface of the panel.

7. The positioning module of claim 1, wherein the first light source and the second light source are respectively actuated by the processor.

8. The positioning module of claim 7, wherein the processor actuates the first light source to generate the first image, and determines whether the second light source is actuated to generate the second image according to the touch status by analyzing the first image.

9. The positioning module of claim 4, wherein the intensity of the first image comprises a plurality of intensity magnitudes, and each intensity magnitude corresponds to a typical value of the each column of the first image.

10. The positioning module of claim 4, wherein the threshold value comprises a plurality of threshold magnitudes, and the threshold magnitudes respectively correspond to intensity thresholds of a plurality of columns of the first image.

11. An optical touch system for calculating coordinates of a touch medium, the optical touch system comprising:

a panel; and

a positioning module disposed on the panel, the positioning module comprising;

at least one image detecting unit, the image detecting unit comprising a lateral side and an upper side;

a first light source disposed on the lateral side for emitting a first beam;

a second light source disposed on the upper side for emitting a second beam; and

a processor electrically connected to the image detecting unit, the processor determining a touch status of the touch medium according to a first image generated by the first beam, and further determining a touch position of the touch medium according to a second image generated by the second beam.

12. The optical touch system of claim 11, wherein the first beam is reflected by a reflection component to project the first image on the image detecting unit, the second beam is reflected by the reflection component to project the second image on the image detecting unit.

13. The optical touch system of claim 12, wherein the image detecting unit detects a first dark area generated on the reflection component because a part of the first beam is shadowed by the touch medium, and determines the touch status according to an intensity of the first dark area on the first image.

14. The optical touch system of claim 13, wherein the image detecting unit determines that the touch medium contacts the panel when the intensity of the first dark area on the first image is lower than a threshold value.

15. The optical touch system of claim 12, wherein the image detecting unit detects a second dark area generated on the reflection component because a part of the second beam is shadowed by the touch medium, and determines the touch position according to a position of the second dark area on the second image.

16. The optical touch system of claim 11, wherein a distance between the first light source and a surface of the panel is substantially smaller than a distance between the second light source and the surface of the panel.

17. The optical touch system of claim 11, wherein the first light source and the second light source are respectively actuated by the processor.

18. The optical touch system of claim 17, wherein the processor actuates the first light source to generate the first image, and determines whether the second light source is actuated to generate the second image according to the touch status by analyzing the first image.

19. The optical touch system of claim 14, wherein the intensity of the first image comprises a plurality of intensity magnitudes, and each intensity magnitude corresponds to a typical value of the each column of the first image.

20. The optical touch system of claim 14, wherein the threshold value comprises a plurality of threshold magnitudes, and the threshold magnitudes respectively correspond to intensity thresholds of a plurality of columns of the first image.

21. A method of calculating coordinates of a touch medium, the method comprising:

emitting a first beam;

emitting a second beam;

receiving a first image generated by the first beam;

determining a touch status of the touch medium according to the first image;

receiving at least one second image generated by the second beam; and

determining a touch position of the touch medium according to the second image.

22. The method of claim 21, further comprising:

reflecting the first beam to an image detecting unit by a reflection component to generate the first image; and

reflecting the second beam to the image detecting unit by the reflection component to generate the second image.

23. The method of claim 22, further comprising:

detecting a first dark area generated on the reflection component because a part of the first beam is shadowed; and

determining the touch status according to an intensity of the first dark area on the first image.

24. The method of claim 23, further comprising:

determining that the touch medium contacts a panel when the intensity of the first dark area on the first image is lower than a threshold value.

25. The method of claim 22, further comprising:

detecting a second dark area generated on the reflection component because a part of the second beam is shadowed; and

determining the touch position according to a position of the second dark area on the second image.

26. The method of claim 21, further comprising:

determining whether the second beam is emitted to generate the second image according to the touch status by analyzing the first image.

27. The method of claim 24, further comprising:

comparing intensity magnitudes of the second image to the threshold value; and

determining that the touch medium does not contact the panel when the intensity of the second image is greater than the threshold value.

28. The method of claim 21, wherein the first beam is emitted by a first light source, the second beam is emitted by a second light source, the first image and the second image are captured by an image detecting unit, the first light source is disposed on a lateral side of the image detecting unit, and the second light source is disposed on an upper side of the image detecting unit.