Optical touch device and related image detecting component and locating method

• US 9,274,650 B2
• Filed: 03/03/2014
• Issued: 03/01/2016
• Est. Priority Date: 11/16/2009
• Status: Expired due to Fees

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Su, Tzung-Min, Ko, Yi-Hsien, Cheng, Hsin-Chi, Kao, Ming-Tsan
• Primary Examiner(s): Wang-Hurst, Kathy
• Assistant Examiner(s): SOTO LOPEZ, JOSE R
• Application Number:
  US14/195,824
• Publication Number:
  US 20140184571A1
• Time in Patent Office: 729 Days
• Field of Search: 345/175, 345/173
• US Class Current: 1/1
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• 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

Abstract

A locating method applied to an optical touch device is disclosed. The optical touch device includes at least one image detecting component for detecting an imaging position of an object and generating a touch position of the object on a plane according to the imaging position. The at least one image detecting component includes a plurality of pixels. The locating method includes dividing the pixels into a first group and a second group along a first direction, analyzing dimension ratios of a darkness point respectively relative to the first group and the second group when the darkness point formed by the object is simultaneously detected by the first group and the second group, and calculating the imaging position of the darkness point inside the image detecting component according to the dimension ratios.

Claims

1. A locating method applied to an optical touch device, the optical touch device comprising at least one image detecting component for detecting an imaging position of an object and generating a touch position of the object on a plane according to the imaging position, the at least one image detecting component comprising a plurality of pixels, the locating method comprising:

dividing the plurality of pixels into a first group and a second group along a first direction;

analyzing dimension ratios of a darkness point respectively relative to the first group and the second group when the darkness point formed by the object is simultaneously detected by the first group and the second group, wherein a first algorithm is utilized to calculate the imaging position of the darkness point inside the image detecting component when the darkness point formed by the object is detected by the first group, and a second algorithm is utilized to calculate the imaging position of the darkness point inside the image detecting component when the darkness point formed by the object is detected by the second group;

utilizing the first algorithm and the second algorithm to respectively calculate a first subgroup imaging position of the darkness point on the first group and a second subgroup imaging position of the darkness point on the second group;

setting the dimension ratio of the darkness point relative to the first group and the dimension ratio of the darkness point relative to the second group as weight indices; and

multiplying the first subgroup imaging position and the second subgroup imaging position respectively by the corresponding weight indices and adding up two multiplication results, so as to obtain the imaging position of the darkness point.

2. The locating method of claim 1, wherein the first algorithm is a gravity center calculating method, and the second algorithm is a medium center calculating method.

3. The locating method of claim 1, wherein the optical touch device comprises a sensory area, a field of view of the second group of each image detecting component covers a corner of the sensory area opposite to the image detecting component.

4. The locating method of claim 1, wherein calculating the imaging position of the darkness point inside the image detecting component according to the dimension ratios comprises:

comparing the dimension ratio of the darkness point relative to the first group with the dimension ratio of the darkness point relative to the second group;

determining whether the darkness point is located at the first group or the second group according to the maximal dimension ratio; and

utilizing the corresponding algorithm to calculate the imaging position of the darkness point.

5. The locating method of claim 1, wherein the darkness point is set on the second group when the dimension ratio of the darkness point relative to the first group is equal to the dimension ratios of the darkness point relative to the second group, or the darkness point is set on the first group or the second group according to an imaging position of a former darkness point detected by the image detecting component.

6. An optical touch device comprising:

a frame comprising a first sidewall, a second sidewall, a third sidewall and a fourth sidewall, the first sidewall being opposite to the third sidewall, the second sidewall being opposite to the fourth sidewall, and a sensory area being formed inside the frame;

a light source module for providing light to the sensory area;

a first image detecting component disposed between two adjacent ends of the first sidewall and the second sidewall, a field of view of the first image detecting component covering the third sidewall and the fourth sidewall; and

a second image detecting component disposed between two adjacent ends of the second sidewall and the third sidewall, a field of view of the second image detecting component covering the first sidewall and the fourth sidewall;

wherein the first image detecting component and the second image detecting component respectively comprise a plurality of pixels, the plurality of pixels is at least divided into a first group and a second group along a first direction, dimension ratios of a darkness point relative to the first group and the second group are respectively analyzed when the darkness point formed by an object is simultaneously detected by the first group and the second group, so as to calculate an imaging position of the darkness point according to the dimension ratios, and to generate a touch position of the object on a plane according to the imaging position, a first algorithm is utilized to calculate the imaging position of the darkness point inside the first image detecting component when the darkness point formed by the object is detected by the first group of the first image detecting component, and a second algorithm is utilized to calculate the imaging position of the darkness point inside the first image detecting component when the darkness point formed by the object is detected by the second group of the first image detecting component, the first image detecting component utilizes the first algorithm and the second algorithm to respectively calculate temporary imaging positions or subgroup imaging positions of the darkness point, sets the dimension ratios of the darkness point relative to the first group and the second group respectively as weight indices, multiplies the temporary imaging positions or the subgroup imaging positions of the darkness point by the corresponding weight indices and adds up two multiplication results, so as to obtain the imaging position of the darkness point.

7. The optical touch device of claim 6, wherein the first algorithm is a gravity center calculating method, and the second algorithm is a medium center calculating method.

8. The optical touch device of claim 6, wherein the first image detecting component compares the dimension ratio of the darkness point relative to the first group with the dimension ratio of the darkness point relative to the second group, and determines whether the darkness point is located at the first group or the second group according to the maximal dimension ratio, so as to utilize the corresponding algorithm to calculate the imaging position of the darkness point.

9. The optical touch device of claim 6, wherein the first image detecting component sets the darkness point on the second group when the dimension ratio of the darkness point relative to the first group is equal to the dimension ratio of the darkness point relative to the second group, or the first image detecting component sets the darkness point on the first group or the second group according to an imaging position of a former darkness point detected by the first image detecting component.

10. The optical touch device of claim 6, wherein the plurality of pixels of the first image detecting component further comprises a third group along the first direction, the third group is located between the first group and the second group, a third algorithm is utilized to calculate the imaging position of the darkness point inside the first image detecting component when the darkness point formed by the object is detected by the third group.

11. The optical touch device of claim 10, wherein the plurality of pixels of the first image detecting component further comprises a fourth group along the first direction, the second group is located between the third group and the fourth group, the first algorithm and the third algorithm are alternatively utilized to calculate the imaging position of the darkness point inside the first image detecting component when the darkness point formed by the object is detected by the fourth group.

12. The optical touch device of claim 6, wherein the plurality of pixels of the second image detecting component further comprises a third group along the first direction, the third group is located between the first group and the second group.

13. The optical touch device of claim 12, wherein the plurality of pixels of the second image detecting component further comprises a fourth group along the first direction, the second group is located between the third group and the fourth group.

14. The optical touch device of claim 6, further comprising:

a plurality of light guiding components respectively disposed on the first sidewall, the third sidewall and the fourth sidewall.

15. An image detecting component applied to an optical touch device, the image detecting component comprising:

a light receiving unit, the light receiving unit comprising a plurality of pixels for receiving an optical signal from an object, the plurality of pixels being divided into a first group and a second group along a first direction;

a digital signal processing unit electrically connected to the light receiving unit for processing the optical signal detected by the plurality of pixels; and

a central processing unit electrically connected to the digital signal processing unit, the central processing unit analyzing dimension ratios of a darkness point respectively relative to the first group and the second group when the darkness point formed by the object is simultaneously detected by the first group and the second group, and calculating an imaging position of the darkness point according to the dimension ratios, so as to generate a touch position of the object on a plane according to the imaging position, wherein the central processing unit utilizes a first algorithm to calculate the imaging position of the darkness point on the light receiving unit when the darkness point formed by the object is detected by the first group, and further utilizes a second algorithm to calculate the imaging position of the darkness point on the light receiving unit when the darkness point formed by the object is detected by the second group, the central processing unit utilizes the first algorithm and the second algorithm to respectively calculate temporary imaging positions or subgroup imaging positions of the darkness point, sets the dimension ratios of the darkness point relative to the first group and the second group respectively as weight indices, multiplies the temporary imaging positions or the subgroup imaging positions of the darkness point by the corresponding weight indices and adds up two multiplication results, so as to obtain the imaging position of the darkness point.

16. The image detecting component of claim 15, wherein the central processing unit compares the dimension ratio of the darkness point relative to the first group with the dimension ratio of the darkness point relative to the second group, determines whether the darkness point is located at the first group or the second group according to the maximal dimension ratio, so as to utilize the corresponding algorithm to calculate the imaging position of the darkness point.

17. The image detecting component of claim 15, wherein the central processing unit sets the darkness point on the second group when the dimension ratio of the darkness point relative to the first group is equal to the dimension ratio of the darkness point relative to the second group, or the central processing unit sets the darkness point on the first group or the second group according to an imaging position of a former darkness point detected by the light receiving unit.

18. The image detecting component of claim 15, wherein the plurality of pixels further comprises a third group along the first direction, the third group is located between the first group and the second group, the central processing unit utilizes a third algorithm to calculate the imaging position of the darkness point on the light receiving unit when the darkness point formed by the object is detected by the third group.

19. The image detecting component of claim 18, wherein the plurality of pixels further comprises a fourth group along the first direction, the second group is located between the third group and the fourth group, the central processing unit utilizes the first algorithm or the third algorithm to calculate the imaging position of the darkness point on the light receiving unit when the darkness point formed by the object is detected by the fourth group.

20. A locating method applied to an optical touch device, the optical touch device comprising at least one image detecting component for detecting an imaging position of an object and generating a touch position of the object on a plane according to the imaging position, the at least one image detecting component comprising a plurality of pixels, the locating method comprising:

dividing the plurality of pixels into a first group and a second group along a first direction;

analyzing dimension ratios of a darkness point respectively relative to the first group and the second group when the darkness point formed by the object is simultaneously detected by the first group and the second group, wherein a first algorithm is utilized to calculate the imaging position of the darkness point inside the image detecting component when the darkness point formed by the object is detected by the first group, and a second algorithm is utilized to calculate the imaging position of the darkness point inside the image detecting component when the darkness point formed by the object is detected by the second group;

utilizing the first algorithm and the second algorithm to respectively calculate a first temporary imaging position and a second temporary imaging position of the darkness point inside the image detecting component;

setting the dimension ratio of the darkness point relative to the first group and the dimension ratio of the darkness point relative to the second group as weight indices; and

multiplying the first temporary imaging position and the second temporary imaging position respectively by the corresponding weight indices and adding up two multiplication results, so as to obtain the imaging position of the darkness point.

21. The locating method of claim 20, wherein the first algorithm is a gravity center calculating method, and the second algorithm is a medium center calculating method.

22. The locating method of claim 20, wherein the optical touch device comprises a sensory area, a field of view of the second group of each image detecting component covers a corner of the sensory area opposite to the image detecting component.

23. The locating method of claim 20, wherein calculating the imaging position of the darkness point inside the image detecting component according to the dimension ratios comprises:

comparing the dimension ratio of the darkness point relative to the first group with the dimension ratio of the darkness point relative to the second group;

determining whether the darkness point is located at the first group or the second group according to the maximal dimension ratio; and

utilizing the corresponding algorithm to calculate the imaging position of the darkness point.

24. The locating method of claim 20, wherein the darkness point is set on the second group when the dimension ratio of the darkness point relative to the first group is equal to the dimension ratios of the darkness point relative to the second group, or the darkness point is set on the first group or the second group according to an imaging position of a former darkness point detected by the image detecting component.

25. A locating method applied to an optical touch device, the optical touch device comprising at least one image detecting component for detecting an imaging position of an object and generating a touch position of the object on a plane according to the imaging position, the at least one image detecting component comprising a plurality of pixels, the locating method comprising:

dividing the plurality of pixels into a first group and a second group along a first direction;

analyzing dimension ratios of a darkness point respectively relative to the first group and the second group when the darkness point formed by the object is with simultaneously detected by the first group and the second group, wherein a first algorithm is utilized to calculate the imaging position of the darkness point inside the image detecting component when the darkness point formed by the object is detected by the first group, and a second algorithm is utilized to calculate the imaging position of the darkness point inside the image detecting component when the darkness point formed by the object is detected by the second group; and

calculating the imaging position of the darkness point inside the image detecting component according to the dimension ratios;

wherein the plurality of pixels is divided into the first group, the second group and a third group along the first direction, the third group is located between the first group and the second group, a third algorithm is utilized to calculate the imaging position of the darkness point inside the image detecting component when the darkness point formed by the object is detected by the third group, and the third algorithm comprises;

utilizing the first algorithm and the second algorithm to respectively calculate a first temporary imaging position and a second temporary imaging position of the darkness point formed by the object to obtain a first value and a second value;

multiplying the first value by a first weight α

to obtain a third value, and multiplying the second value by a second weight (1-α

) to obtain a fourth value, wherein a is greater than or equal to 0 and is further smaller than or equal to 1; and

adding up the third value and the fourth value to obtain the imaging position of the darkness point.

26. The locating method of claim 25, wherein the first weight α

used by the third algorithm becomes larger when an amount of the pixels of the third group close to the first group for detecting the darkness point formed by the object becomes greater.

27. The locating method of claim 25, wherein the plurality of pixels is further divided into the first group, the second group, the third group and a fourth group along the first direction, the second group is located between the third group and the fourth group, the first algorithm and the third algorithm are alternatively utilized to calculate the imaging position of the darkness point inside the image detecting component when the darkness point formed by the object is detected by the fourth group.