Locating method of optical touch device and optical touch device

• US 8,994,693 B2
• Filed: 04/08/2010
• Issued: 03/31/2015
• Est. Priority Date: 11/16/2009
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Kao, Ming-Tsan, Cheng, Hsin-Chi, Hsu, Teng-Wei
• Primary Examiner(s): Horner, Jonathan
• Assistant Examiner(s): SOTO LOPEZ, JOSE R
• Application Number:
  US12/756,852
• Publication Number:
  US 20110116104A1
• Time in Patent Office: 1,818 Days
• Field of Search: 345/175, 345/166, 345/173, 358/448
• US Class Current: 345/175
• 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 for an optical touch device to calculate a position of a light blocking object is provided. The optical touch device includes a number of image detecting components. Each of the image detecting components includes a number of pixels arranged in a straight line. In the locating method, the pixels of each of the image detecting components are at least divided into a first group and a second group. When the first group detects a dark point caused by the light blocking object, the position of the dark point is calculated using a first calculating method. When the second group detects the dark point, the position of the dark point is calculated using a second calculating method. The locating method can determine the position of the light blocking object accurately. An optical touch device that is suitable for using the locating method is also provided.

Claims

1. A locating method for an optical touch device to calculate a position of a light blocking object in a detecting area of the optical touch device, the optical touch device comprising a plurality of image detecting components, each of the image detecting components having a plurality of pixels arranged in a straight line, the locating method comprising:

dividing the pixels of each of the image detecting components at least into a first group and a second group, the first group being configured for detecting a first partial field of view and the second group being configured for detecting a second partial field of view, and the first partial field of view and second partial field of view of the same image detecting component being different and not overlapped with each other, wherein the first group and the second group of the same image detecting component detect different portions of the detecting area, the portions detected by the first group and the second group are not overlapped with each other, in each of the image detecting components, when the first group detects a dark point caused by the light blocking object, the position of the dark point imaged in the pixels of the first group is calculated using a first calculating method, and when the second group detects the dark point caused by the light blocking object, the position of the dark point imaged in the pixels of the second group is calculated using a second calculating method.

2. The locating method as claimed in claim 1, wherein the first calculating method is a gravity center calculating method, and the second calculating method is a medium center calculating method.

3. The locating method as claimed in claim 2, wherein the optical touch device comprises a detecting area, a field of view of the second group of each of the image detecting components covers a corner area of the detecting area, and the corner area faces to the corresponding image detecting component.

4. The locating method as claimed in claim 1, wherein the pixels of each of the image detecting components are divided into the first group, the second group and a third group between the first group and the second group,

wherein the first group, the second group and the third group of the same image detecting component detect different portions of the detecting area, the portions detected by the first group, the second group and the third group are not overlapped with each other, and when the third group detects the dark point caused by the light blocking object, the position of the dark point imaged in the pixels of the third group is calculated using a third calculating method.

5. The locating method as claimed in claim 4, wherein the third calculating method comprises the steps of:

calculating the position of the dark point caused by the light blocking object imaged in the pixels of the third group using the first calculating method and the second calculating method respectively to obtain a first value and a second value;

multiplying the first value with a first weight a to obtain a third value and multiplying the second value with a second weight (1−

α

) to obtain a fourth value, and 0<

α

<

1; and

adding the third value and the fourth value together.

6. The locating method as claimed in claim 5, wherein when the pixels of the third group detecting the dark point caused by the light blocking object become closer to the first group, the first weight a becomes lager correspondingly.

7. The locating method as claimed in claim 4, wherein the pixels of each of the image detecting components are divided into the first group, the second group, the third group and a fourth group, the second group is located between the third group and the fourth group,

wherein the first group, the second group, the third group and the fourth group of the same image detecting component detect different portions of the detecting area, the portions detected by the first group, the second group, the third group and the fourth group are not overlapped with each other, and when the fourth group detects the dark point caused by the light blocking object, the position of the dark point is calculated using either the first calculating method or the third calculating method.

8. The locating method as claimed in claim 2, wherein the detecting area has a first corner area, a second corner area, a third corner area and a fourth corner area,

wherein the first corner area and the third corner area are opposite to each other diagonally, the second corner area and the fourth corner area are opposite to each other diagonally, one of the image detecting components is set at the first corner area, the field of view of the second group of the image detecting component set at the first corner covers the third corner area, and the field of view of the first group of the image detecting component set at the first corner does not cover the third corner area.

16. The locating method as claimed in claim 4, wherein the first group being configured for detecting a first partial field of view, the second group being configured for detecting a second partial field of view, and the third group being configured for detecting a third partial field of view, and the first partial field of view and second partial field of view and the third partial field of view being different and not overlapped with each other.

17. The locating method as claimed in claim 7, wherein the first group being configured for detecting a first partial field of view, the second group being configured for detecting a second partial field of view, and the third group being configured for detecting a third partial field of view, and the fourth group being configured for detecting a fourth partial field of view, and the first partial field of view and second partial field of view and the third partial field of view and the fourth partial field of view being different and not overlapped with each other.

9. An optical touch device, comprising:

a frame comprising a first sidewall, a second sidewall, a third sidewall and a fourth sidewall, the first sidewall facing to the third sidewall, the second sidewall facing to the fourth sidewall, the frame defining a detecting area therein;

a light source module configured for providing light to the detecting area;

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

wherein each of the first image detecting component and the second image detecting component comprises a plurality of pixels arranged in a straight line, the pixels of each of the first image detecting component and the second image detecting component at least comprises a first group and a second group, the first group being configured for detecting a first partial field of view and the second group being configured for detecting a second partial field of view, and the first partial field of view and second partial field of view of the same first image detecting component being different and not overlapped with each other, the first partial field of view and second partial field of view of the second image detecting component being different and not overlapped with each other, wherein the first group and the second group of the same first image detecting component or second image detecting component detect different portions of the detecting area, the portions detected by the first group and the second group are not overlapped with each other, when the first group detects a dark point caused by a light blocking object in the detecting area, a position of the dark point imaged in the pixels of the first group is calculated using a first calculating method, and when the second group detects the dark point caused by the light blocking object in the detecting area, the position of the dark point imaged in the pixels of the second group is calculated using a second calculating method.

10. The optical touch device as claimed in claim 9, wherein the third sidewall comprises a first section connected to the second sidewall and a second section connected to the fourth sidewall, the first group of the first image detecting component is configured for detecting the first section, the second group of the first image detecting component is configured for detecting the second section and the fourth sidewall, the first sidewall comprises a third section connected to the second sidewall and a fourth section connected to the fourth sidewall, the first group of the second image detecting component is configured for detecting the third section, and the second group of the second image detecting component is configured for detecting the fourth section and the fourth sidewall.

11. The optical touch device as claimed in claim 9, wherein the pixels of each of the first image detecting component and the second image detecting component further comprises a third group between the first group and the second group,

wherein the first group, the second group and the third group of the same first image detecting component or second image detecting component detect different portions of the detecting area, the portions detected by the first group, the second group and the third group are not overlapped with each other, and when the third group detects the dark point caused by the light blocking object in the detecting area, the position of the dark point imaged in the pixels of the third group is calculated using a third calculating method.

12. The optical touch device as claimed in claim 11, wherein the third sidewall comprises a first section connected to the second sidewall, a second section connected to the fourth sidewall and a fifth section connected between the first section and the second section, the first group of the first image detecting component is configured for detecting the first section, the second group of the first image detecting component is configured for detecting the second section and the fourth sidewall, the third group of the first image detecting component is configured for detecting the fifth section, the first sidewall comprises a third section connected to the second sidewall, a fourth section connected to the fourth sidewall and a sixth section connected between the third section and the fourth section, the first group of the second image detecting component is configured for detecting the third section, the second group of the second image detecting component is configured for detecting the fourth section and the fourth sidewall, and the third group of the second image detecting component is configured for detecting the sixth section.

13. The optical touch device as claimed in claim 9, wherein the pixels of each of the first image detecting component and the second image detecting component further comprises a third group and a fourth group, the third group is located between the first group and the second group, the second group is located between the third group and the fourth group,

wherein the first group, the second group, the third group and the fourth group of the same first image detecting component or second image detecting component detect different portions of the detecting area, the portions detected by the first group, the second group, the third group and the fourth group are not overlapped with each other, when the third group detects the dark point caused by the light blocking object in the detecting area, the position of the dark point imaged in the pixels of the third group is calculated using a third calculating method, and when the fourth group detects the dark point caused by the light blocking object in the detecting area, the position of the dark point imaged in the pixels of the fourth group is calculated using either the first calculating method or the third calculating method.

14. The optical touch device as claimed in claim 13, wherein the third sidewall comprises a first section connected to the second sidewall, a second section connected to the fourth sidewall and a fifth section connected between the first section and the second section, the first group of the first image detecting component is configured for detecting the first section, the second group of the first image detecting component is configured for detecting the second section and a section of the fourth sidewall adjacent to the third sidewall, the third group of the first image detecting component is configured for detecting the fifth section, the fourth group of the first image detecting component is configured for detecting a section of the fourth sidewall adjacent to the first sidewall, the first sidewall comprises a third section connected to the second sidewall, a fourth section connected to the fourth sidewall and a sixth section connected between the third section and the fourth section, the first group of the second image detecting component is configured for detecting the third section, the second group of the second image detecting component is configured for detecting the fourth section and a section of the fourth sidewall adjacent to the first sidewall, the third group of the second image detecting component is configured for detecting the sixth section, and the fourth group of the second image detecting component is configured for detecting a section of the fourth sidewall adjacent to the third sidewall.

15. The optical touch device as claimed in claim 9, further comprising a plurality of light guide components, wherein the light guide components are at least disposed on the first sidewall, the third sidewall and the fourth sidewall.

18. The optical touch device as claimed in claim 11, wherein the first group being configured for detecting a first partial field of view, the second group being configured for detecting a second partial field of view, and the third group being configured for detecting a third partial field of view, and the first partial field of view and second partial field of view and the third partial field of view being different and not overlapped with each other.

19. The optical touch device as claimed in claim 13, wherein the first group being configured for detecting a first partial field of view, the second group being configured for detecting a second partial field of view, and the third group being configured for detecting a third partial field of view, and the fourth group being configured for detecting a fourth partial field of view, and the first partial field of view and second partial field of view and the third partial field of view and the fourth partial field of view being different and not overlapped with each other.