Image sensing module and optical sensing system

• US 8,947,403 B2
• Filed: 06/23/2011
• Issued: 02/03/2015
• Est. Priority Date: 01/25/2011
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Lu, Chih-Hung, Su, Tzung-Min, Lin, Chih-Hsin, Yang, Shu-Sian, Yao, Wen-Han
• Primary Examiner(s): Chang, Kent
• Assistant Examiner(s): BRITTINGHAM, NATHANIEL P
• Application Number:
  US13/166,818
• Publication Number:
  US 20120188203A1
• Time in Patent Office: 1,321 Days
• Field of Search: None
• US Class Current: 345/175
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

An image sensing module utilizes an image sensor to sense objects and a mirror image of the objects in a mirror through a plurality of first light filtering components with a first transmission spectrum and a plurality of second light filtering components with a second transmission spectrum for generating an image. A light filtering module substantially having the first transmission spectrum is disposed in front of the mirror. The image includes a plurality of pixels. Each pixel includes a first sub data and a second sub data. The image sensing module utilizes an image sensing controller to detect real images corresponding to the objects and virtual images correspond to the mirror image of the objects from the image according to the first sub data and the second sub data of the plurality of pixels.

Claims

1. An image sensing module, comprising:

a first light filtering module comprising a plurality of first light filtering components with a first transmission spectrum and a plurality of second light filtering components with a second transmission spectrum;

an image sensor for generating a first image by receiving an image of multiple objects through the first light filtering module and receiving a mirror image of the objects reflected from a mirror through the first light filtering module, wherein a second light filtering module substantially having the first transmission spectrum is arranged in front of the mirror, the first image comprises a plurality of pixels, and each pixel comprises a first sub data corresponding to light transmitted through at least a first light filtering component and a second sub data corresponding to light transmitted through at least a second light filtering component, wherein the image sensor comprises a plurality of first sensing units and a plurality of second sensing units, the first sensing units and the second sensing units are interlacedly arranged, the first sub data is generated by using interpolation according to first sensing signals generated by the first sensing units, and the second sub data is generated by using interpolation according to second sensing signals generated by the second sensing units; and

a sensing controller electrically connected to the image sensor, for determining a first set of real images of the objects and a first set of virtual images of the objects reflected from the mirror according to the first sub data and the second sub data of the plurality of pixels.

2. The image sensing module of claim 1 wherein the sensing controller determines an image area of the first image according to the first sub data of the plurality of pixels.

3. The image sensing module of claim 2 wherein when a first sub data of one of the plurality of pixels is greater than an image threshold value, the sensing controller determines the pixel is in the image area.

4. The image sensing module of claim 2 wherein the sensing controller determines whether a pixel in the image area belongs to the first set of real images or the first set of virtual images by comparing the first sub data and the second sub data of the pixel.

5. The image sensing module of claim 4 wherein when a result of subtracting the second sub data from the first sub data of the pixel in the image area is greater than a virtual image threshold value, the sensing controller determines the pixel belongs to the first set of virtual images.

6. The image sensing module of claim 4 wherein when a result of subtracting the second sub data from the first sub data of the pixel in the image area is less than a virtual image threshold value, the sensing controller determines the pixel belongs to the first set of real images.

7. The image sensing module of claim 2 wherein the first light filtering module further comprises a plurality of third light filtering components with a third transmission spectrum;

wherein each of the pixels further comprises a third sub data corresponding to light transmitted through at least a third light filtering component, and the sensing controller determines the first set of real images of the objects and the first set of virtual images of the objects reflected from the mirror according to the first sub data, the second sub data, and the third sub data of the plurality of pixels.

8. The image sensing module of claim 7 wherein the sensing controller determines whether a pixel in the image area belongs to the first set of real images or the first set of virtual images according to the first sub data, the second sub data, and the third sub data of the pixel.

9. The image sensing module of claim 8 wherein when a result of subtracting the second sub data from the first sub data of the pixel in the image area is greater than a first virtual image threshold value, and a result of subtracting the third sub data from the first sub data of the pixel is greater than a second virtual image threshold value, the sensing controller determines the pixel belongs to the first set of virtual image.

10. The image sensing module of claim 8 wherein when a result of subtracting the second sub data from the first sub data of the pixel in the image area is less than a first virtual image threshold value, and a result of subtracting the third sub data from the first sub data of the pixel is less than a second virtual image threshold value, the sensing controller determines the pixel belongs to the first set of real image.

11. An optical sensing system, comprising:

a sensing area with a plurality of edges;

a first light filtering module with a first transmission spectrum;

a mirror for generating a mirror image of the sensing area by receiving and reflecting light through the first light filtering module;

a first image sensing module, comprising;

a second light filtering module comprising a plurality of first light filtering components with the first transmission spectrum and a plurality of second light filtering components with a second transmission spectrum;

a first image sensor for generating a first image by receiving an image of multiple objects through the second light filtering module and receiving a mirror image of the objects reflected from the mirror through the second light filtering module, wherein the first image comprises a plurality of first pixels, and each first pixel comprises a first sub data corresponding to light transmitted through at least a first light filtering component and a second sub data corresponding to light transmitted through at least a second light filtering component, wherein the first image sensor comprises a plurality of first sensing units and a plurality of second sensing units, the first sensing units and the second sensing units are interlacedly arranged, the first sub data is generated by using interpolation according to first sensing signals generated by the first sensing units, and the second sub data is generated by using interpolation according to second sensing signals generated by the second sensing units; and

a first sensing controller electrically connected to the first image sensor, for determining a first set of real images of the objects and a first set of virtual images of the objects reflected from the mirror according to the first sub data and the second sub data of the plurality of first pixels; and

a processing circuit electrically connected to the first sensing controller, for generating a first set of candidate coordinates of the objects according to the first set of real images and the first set of virtual images.

12. The optical sensing system of claim 11 wherein the first sensing controller determines an image area of the first image according to the first sub data of the plurality of first pixels.

13. The optical sensing system of claim 12 wherein when a first sub data of one of the plurality of first pixels is greater than an image threshold value, the first sensing controller determines the first pixel is in the image area.

14. The optical sensing system of claim 12 wherein the first sensing controller determines whether a first pixel in the image area belongs to the first set of real images or the first set of virtual images by comparing the first sub data and the second sub data of the first pixel.

15. The optical sensing system of claim 14 wherein when a result of subtracting the second sub data from the first sub data of the first pixel in the image area is greater than a virtual image threshold value, the sensing controller determines the first pixel belongs to the first set of virtual images.

16. The optical sensing system of claim 14 wherein when a result of subtracting the second sub data from the first sub data of the first pixel in the image area is less than a virtual image threshold value, the sensing controller determines the first pixel belongs to the first set of real images.

17. The optical sensing system of claim 12 wherein the second light filtering module further comprises a plurality of third light filtering components with a third transmission spectrum;

wherein each of the first pixels further comprises a third sub data corresponding to light transmitted through at least a third light filtering component, and the first sensing controller determines the first set of real images of the objects and the first set of virtual images of the objects reflected from the mirror according to the first sub data, the second sub data, and the third sub data of the plurality of first pixels.

18. The optical sensing system of claim 17 wherein the first sensing controller determines whether a first pixel in the image area belongs to the first set of real images or the first set of virtual images according to the first sub data, the second sub data, and the third sub data of the first pixel.

19. The optical sensing system of claim 18 wherein when a result of subtracting the second sub data from the first sub data of the first pixel in the image area is greater than a first virtual image threshold value, and a result of subtracting the third sub data from the first sub data of the first pixel is greater than a second virtual image threshold value, the first sensing controller determines the first pixel belongs to the first set of virtual image.

20. The image sensing module of claim 18 wherein when a result of subtracting the second sub data from the first sub data of the first pixel in the image area is less than a first virtual image threshold value, and a result of subtracting the third sub data from the first sub data of the first pixel is less than a second virtual image threshold value, the sensing controller determines the first pixel belongs to the first set of real image.

21. The optical sensing system of claim 11 further comprising a third light filtering module with a third transmission spectrum;

wherein the mirror comprises a first area for receiving and reflecting light through the first light filtering module, and a second area for receiving and reflecting light through the third light filtering module.

22. The optical sensing system of claim 11 further comprising a light emitting element for emitting light to the sensing area.

23. The optical sensing system of claim 22, wherein the light emitting element is arranged nearby the first image sensing module.

24. The optical sensing system of claim 11, wherein the first transmission spectrum is a red color transmission spectrum, and the second transmission spectrum is a green or blue color transmission spectrum.

25. The optical sensing system of claim 11 further comprising:

a second image sensing module, comprising;

a third light filtering module comprising a plurality of third light filtering components with the first transmission spectrum and a plurality of fourth light filtering components with the second transmission spectrum;

a second image sensor for generating a second image by receiving an image of the objects through the third light filtering module and receiving a mirror image of the objects reflected from the mirror through the second light filtering module, wherein the second image comprises a plurality of second pixels, and each second pixel comprises a third sub data corresponding to light transmitted through at least a third light filtering component and a fourth sub data corresponding to light transmitted through at least a fourth light filtering component; and

a second sensing controller electrically connected to the second image sensor, for determining a second set of real images of the objects and a second set of virtual images of the objects reflected from the mirror according to the third sub data and the fourth sub data of the plurality of second pixels;

wherein the processing circuit generates a second set of candidate coordinates of the objects according to the second set of real images and the second set of virtual images, and the processing circuit compares the first set of candidate coordinates and the second set of candidate coordinates.

26. An optical sensing system, comprising:

a sensing area with a plurality of edges;

a first light filtering module with a first transmission spectrum;

a mirror for generating a mirror image of the sensing area by receiving and reflecting light through the first light filtering module;

a first image sensing module, comprising;

a second light filtering module comprising a plurality of first light filtering components with the first transmission spectrum and a plurality of second light filtering components with a second transmission spectrum;

a first image sensor for generating a first image by receiving an image of multiple objects through the second light filtering module and receiving a mirror image of the objects reflected from the mirror through the second light filtering module, wherein the first image comprises a plurality of first pixels, and each first pixel comprises a first sub data corresponding to light transmitted through at least a first light filtering component and a second sub data corresponding to light transmitted through at least a second light filtering component, wherein the first image sensor comprises a plurality of first sensing units and a plurality of second sensing units, the first sensing units and the second sensing units are interlacedly arranged, the first sub data is generated by using interpolation according to first sensing signals generated by the first sensing units, and the second sub data is generated by using interpolation according to second sensing signals generated by the second sensing units; and

a first sensing controller electrically connected to the first image sensor, for determining a first set of real images of the objects and a first set of virtual images of the objects reflected from the mirror according to the first sub data and the second sub data of the plurality of first pixels;

a second image sensing module, comprising;

a third light filtering module comprising a plurality of third light filtering components with the first transmission spectrum and a plurality of fourth light filtering components with the second transmission spectrum;

a second image sensor for generating a second image by receiving an image of the objects through the third light filtering module and receiving a mirror image of the objects reflected from the mirror through the second light filtering module, wherein the second image comprises a plurality of second pixels, and each second pixel comprises a third sub data corresponding to light transmitted through at least a third light filtering component and a fourth sub data corresponding to light transmitted through at least a fourth light filtering component; and

a second sensing controller electrically connected to the second image sensor, for determining a second set of real images of the objects and a second set of virtual images of the objects reflected from the mirror according to the third sub data and the fourth sub data of the plurality of second pixels; and

a processing circuit electrically connected to the first sensing controller and the second sensing controller, for generating a set of real image candidate coordinates of the objects according to the first set of real images and the second set of real images, and generating a set of virtual image candidate coordinates of the objects according to the first set of virtual images and the second set of virtual images, the processing circuit further generating a set of output coordinates according to the set of real image candidate coordinates and the set of virtual image candidate coordinates.

27. The optical sensing system of claim 26 wherein the first sensing controller determines an image area of the first image according to the first sub data of the plurality of first pixels.

28. The optical sensing system of claim 27 wherein when a first sub data of one of the plurality of first pixels is greater than an image threshold value, the first sensing controller determines the first pixel is in the image area.

29. The optical sensing system of claim 27 wherein the first sensing controller determines whether a first pixel in the image area belongs to the first set of real images or the first set of virtual images by comparing the first sub data and the second sub data of the first pixel.

30. The optical sensing system of claim 29 wherein when a result of subtracting the second sub data from the first sub data of the first pixel in the image area is greater than a virtual image threshold value, the sensing controller determines the first pixel belongs to the first set of virtual image.

31. The optical sensing system of claim 29 wherein when a result of subtracting the second sub data from the first sub data of the first pixel in the image area is less than a virtual image threshold value, the sensing controller determines the first pixel belongs to the first set of real image.

32. The optical sensing system of claim 27 wherein the second light filtering module further comprises a plurality of fifth light filtering components with a third transmission spectrum;

wherein each of the first pixels further comprises a third sub data corresponding to light transmitted through at least a fifth light filtering component, and the first sensing controller determines the first set of real images of the objects and the first set of virtual images of the objects reflected from the mirror according to the first sub data, the second sub data, and the third sub data of the plurality of first pixels.

33. The optical sensing system of claim 32 wherein the first sensing controller determines whether a first pixel in the image area belongs to the first set of real images or the first set of virtual images according to a first sub data, a second sub data, and a third sub data of the first pixel.

34. The optical sensing system of claim 33 wherein when a result of subtracting the second sub data from the first sub data of the first pixel in the image area is greater than a first virtual image threshold value, and a result of subtracting the third sub data from the first sub data of the first pixel is greater than a second virtual image threshold value, the first sensing controller determines the first pixel belongs to the first set of virtual images.

35. The image sensing module of claim 33 wherein when a result of subtracting the second sub data from the first sub data of the first pixel in the image area is less than a first virtual image threshold value, and a result of subtracting the third sub data from the first sub data of the first pixel is less than a second virtual image threshold value, the sensing controller determines the first pixel belongs to the first set of real images.

36. The optical sensing system of claim 26 further comprising a fourth light filtering module with a third transmission spectrum;

wherein the mirror comprises a first area for receiving and reflecting light through the first light filtering module, and a second area for receiving and reflecting light through the fourth light filtering module.

37. The optical sensing system of claim 26 further comprising a light emitting element for emitting light to the sensing area.

38. The optical sensing system of claim 37, wherein the light emitting element is arranged nearby the first image sensing module.

39. The optical sensing system of claim 26, wherein the first transmission spectrum is a red color transmission spectrum, and the second transmission spectrum is a green or blue color transmission spectrum.