Positioning module, optical touch system and method of calculating a coordinate of a touch medium

• US 9,134,855 B2
• Filed: 03/21/2013
• Issued: 09/15/2015
• 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
• Primary Examiner(s): Lao, Lun Yi
• Assistant Examiner(s): McLoone, Peter D
• Application Number:
  US13/848,720
• Publication Number:
  US 20140146016A1
• Time in Patent Office: 908 Days
• Field of Search: 345/156, 345/165, 345/175, 345/179, 250/221, 250/206.1, 178/19.05
• US Class Current: 1/1
• 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 bottom side, a lateral side and an upper side, the bottom side being opposite to the upper side and the lateral side being connected between the bottom side and the upper side, the bottom side of the image detecting unit being disposed on a panel;

a first light source disposed on the panel whereon the bottom side is disposed, and the first light source being adjacent to the lateral side for emitting a first beam;

a second light source disposed on the upper side for emitting a second beam, wherein an angle between the panel and a projection direction of the second light source is greater than an angle between the panel and a projection direction of the first light source; 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, wherein the first light source and the second light source are respectively actuated by the processor, 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.

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 the 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 the panel is substantially smaller than a distance between the second light source and the surface of the panel.

7. 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.

8. 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.

9. 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 bottom side, a lateral side and an upper side, the bottom side being opposite to the upper side and the lateral side being connected between the bottom side and the upper side, the bottom side of the image detecting unit being disposed on the panel;

a first light source disposed on the panel whereon the bottom side is disposed, and the first light source being adjacent to the lateral side for emitting a first beam;

a second light source disposed on the upper side for emitting a second beam, wherein an angle between the panel and a projection direction of the second light source is greater than an angle between the panel and a projection direction of the first light source; 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, wherein the first light source and the second light source are respectively actuated by the processor, 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.

10. The optical touch system of claim 9, 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.

11. The optical touch system of claim 10, 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.

12. The optical touch system of claim 11, 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.

13. The optical touch system of claim 10, 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.

14. The optical touch system of claim 9, 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.

15. The optical touch system of claim 12, 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.

16. The optical touch system of claim 12, 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.

17. A method of calculating coordinates of a touch medium, the method being applied to a positioning module disposed on a panel, the positioning module comprising at least one image detecting unit, the image detecting unit comprising a bottom side, a lateral side and an upper side, the bottom side being opposite to the upper side and the lateral side being connected between the bottom side and the upper side, the bottom side of the image detecting unit being disposed on the panel, the method comprising:

emitting a first beam by a first light source disposed on the panel whereon the bottom side is disposed and adjacent to the lateral side;

emitting a second beam by a second light source disposed on the upper side, wherein an angle between the panel and a projection direction of the second light source is greater than an angle between the panel and a projection direction of the first light source;

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;

determining a touch position of the touch medium according to the second image; and

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

18. The method of claim 17, 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.

19. The method of claim 18, 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.

20. The method of claim 19, further comprising:

determining 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.

21. The method of claim 18, 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.

22. The method of claim 20, 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.