System and method of determining a position of a radiation scattering/reflecting element

• US 7,465,914 B2
• Filed: 09/09/2004
• Issued: 12/16/2008
• Est. Priority Date: 09/12/2003
• Status: Expired due to Fees

• Current Assignee: FlatFrog Laboratories AB
• Original Assignee: FlatFrog Laboratories AB
• Inventors: Eliasson, Jonas Ove Philip, Ostergaard, Jens Wagenblast Stubbe
• Primary Examiner(s): Lee; John R
• Application Number:
  US10/571,567
• Publication Number:
  US 20070125937A1
• Time in Patent Office: 1,559 Days
• Field of Search: 250/221, 250/222.1, 345/173, 345/175, 345/176, 178/18.09
• US Class Current: 250/221
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 2203/04109 FTIR in optical digitiser, i.e. touch detection by frustrating the total internal reflection within an optical waveguide due to changes of optical properties or deformation at the touch location
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

A method and system for determining the position of a radiation scattering/reflecting element, where the radiation emitter is provided at a surface of a radiation transmissive element an on which radiation is incident. This incident radiation is scattered/diffused/reflected by the scattering/reflecting element and guided by the transmissive element toward a detector able to determine the position of the element.

Claims

1. A system for determining a position of a radiation reflecting/scattering element, the system comprising:

a transmissive element or plate having a first surface part adapted to be engaged by the reflecting/scattering element and a second surface part being opposite to the first surface part,

a radiating element adapted to provide radiation into the transmissive element and onto the first surface part,

a detector adapted to detect radiation provided by the radiating element and that is reflected/scattered by the reflecting/scattering element when engaging the first surface part at a position thereof and outputting a signal relating to an angle of incidence of the radiation, the transmissive element being adapted to guide the reflected/scattered light via total internal reflection to the detector, the detector being at least one at least one-dimensional detector having a plurality of detecting elements each being adapted to detect radiation and to output a corresponding signal,

at least one aperture, pinhole, or lens arranged between the transmissive element and the detector and adapted to modulate radiation incident on the detecting elements, and

a determining element adapted to determine, on the basis of angle signal, a position of engagement of the reflecting/scattering element on the first surface part.

2. A system according to claim 1, wherein the radiating element comprises a reflecting element adapted to reflect radiation that penetrates the transmissive element from the first surface part to the second surface part back into the transmissive element.

3. A system according to claim 1, wherein the radiating element is a monitor or screen positioned at a second surface part of the transmissive element opposite to the first surface part and in a manner so as to emit radiation through the transmissive element onto the first surface part.

4. A system according to claim 3, wherein the monitor or screen is adapted to provide radiation of different characteristics onto different areas of the first surface part.

5. A system according to claim 3, wherein the transmissive element further comprises a converting element adapted to convert radiation from the monitor or screen, the converting element being adapted to provide radiation of different characteristics onto different areas of the first surface part, and the detecting elements being adapted to detect the different characteristics.

6. A system according to claim 1, wherein the transmissive element has a shape of a plate or sheet, the system further comprising a transferring element adapted to engage with the transmissive element so as to transfer radiation transmitted by the transmissive element to the detector.

7. A system according to claim 3, wherein the transmissive element comprises, at the first surface part thereof, a converting element adapted to convert radiation from the monitor or screen and reflected/scattered by the reflecting/scattering element, the converting element being adapted to provide radiation of different characteristics from different areas of the first surface part, and the detecting elements being adapted to detect the different characteristics.

8. A system according to claim 1, further comprising a filtering element adapted to filter radiation incident on the detecting elements.

9. A system according to claim 1, further comprising a second reflecting/scattering element, positioned at the second surface part, adapted to reflect or scatter radiation having a first wavelength and being incident thereon from the first surface part and from a first angle to the first surface part to a direction inside the transmissive element and having a second angle to the first surface part, the second angle being lower than the first angle.

10. A system according to claim 9, wherein the second reflecting/scattering element being provided in predetermined areas over the second surface area.

11. A system according to claim 10, wherein the detector and the predetermined areas are provided at positions so that, from each of a number of the predetermined areas, no other predetermined area exists along a straight line between the predetermined area and the detector.

12. A system according to claim 9, wherein the second reflecting/scattering element is adapted to reflect radiation having a second wavelength, being different from the first wavelength, and having a third angle to the first surface part, back toward the first surface part at an angle being at least substantially equal to the third angle.

13. A system according to claim 1, further comprising a second reflecting/scattering element adapted to provide the radiation to a predetermined area of the first surface part, the second reflecting/scattering element being adapted to prevent radiation onto areas adjacent to the predetermined area.

14. A system according to claim 13, wherein the second reflecting/scattering element comprises a radiation blocking area at or on adjacent areas of the first surface part.

15. A system according to claim 13, wherein the predetermined area is oblong shaped.

16. A system according to claim 15, wherein the predetermined area has a length of approximately ½

-20cm.

17. A system according to claim 1, further comprising:

one or more radiation emitters adapted to transmit electromagnetic radiation into the transmissive element and toward the first surface thereof, and

an element adapted to prevent radiation from traveling directly from the emitters to the detector.

18. A system according to claim 1, further comprising a force sensing element adapted to sense a force applied by the reflecting/scattering element onto the transmissive element.

19. A system according to claim 2, further comprising a reflective element extending in a direction of the first surface part, and having a plurality of predetermined areas, the reflective element being adapted to, in the areas, provide radiation transmission from the first surface part toward the second surface part and, outside the areas, provide reflection of radiation traveling from the second surface part toward the first surface part back toward the second surface part.

20. A method for determining a position of a radiation reflecting/scattering element, the method comprising:

providing radiation into a transmissive element or plate and onto a first surface part thereof, the transmissive element having a second surface part being opposite to the first surface part,

providing engagement between the reflecting/scattering element and the first surface part of the transmissive element,

guiding the reflected/scattered light via total internal reflection in the transmissive element to a detecting means being at least one at least one-dimensional detector having a plurality of detecting elements each detecting the radiation and outputting a corresponding signal,

modulating radiation incident on the detecting means with at least one aperture, pinhole, or lens arranged between the transmissive element and the detector,

detecting using the detecting means, radiation which is provided into the transmissive element and reflected/scattered by the reflecting/scattering element engaging the first surface part at a position thereof, and modulated by the at least one aperture, pinhole, or lens, and providing a signal relating to an angle of incidence of the radiation, and

determining, on the basis of the angle signal, a position of engagement of the reflecting/scattering element on the first surface part.

21. A method according to claim 20, wherein the radiation providing step comprises reflecting the radiation that penetrates the transmissive element from the first surface part to the second surface part back into the transmissive element.

22. A method according to claim 20, wherein the radiation providing step comprises providing the radiation from a monitor or screen positioned at a second surface part of the transmissive element opposite to the first surface part in a manner so that radiation is emitted through the transmissive element onto the first surface part.

23. A method according to claim 22, wherein the monitor or screen provides radiation of different characteristics onto different areas of the first surface part.

24. A method according to claim 22, wherein the radiation providing step comprises converting radiation from the monitor or screen, the converting step includes providing radiation of different characteristics onto different areas of the first surface part, and the detecting step includes detecting the different characteristics.

25. A method according to claim 20, wherein the transmissive element has a shape of a plate or sheet, and the detecting step includes transferring radiation transmitted by the transmissive element to the detector.

26. A method according to claim 22, further comprising the step of converting, at the first surface part, radiation from the monitor or screen and reflected/scattered by the reflecting/scattering element, wherein the converting step includes providing radiation of different characteristics from different areas of the first surface part, and the detecting step includes detecting the different characteristics.

27. A method according to claim 20, wherein the detecting step comprises filtering radiation incident on the detecting elements.

28. A method according to claim 20, further comprising a second step of reflecting/scattering, at the second surface part, radiation having a first wavelength and being incident thereon from the first surface part and from a first angle to the first surface part to a direction inside the transmissive element and having a second angle to the first surface part, the second angle being lower than the first angle.

29. A method according to claim 28, wherein the second reflecting/scattering step is performed in predetermined areas over the second surface area.

30. A method according to claim 29, further comprising positioning the detecting means and the predetermined areas at positions so that, from each of a number of the predetermined areas, no other predetermined area exists along a straight line between the predetermined area and the detecting means.

31. A method according to claim 28, wherein the second reflecting/scattering step comprises reflecting radiation having a second wavelength being different from the first wavelength and having a third angle to the first surface part, back toward the first surface part at an angle being at least substantially equal to the third angle.

32. A method according to claim 20, wherein the providing step further comprises providing the radiation to a predetermined area of the first surface part, the second providing step includes preventing radiation onto areas adjacent to the predetermined area.

33. A method according to claim 32, wherein the second providing step comprises preventing or blocking radiation at or on adjacent areas of the first surface part.

34. A method according to claim 32, wherein the providing step comprises providing the radiation to an oblong area.

35. A method according to claim 34, wherein providing step comprises providing the radiation to an oblong area having a length of approximately ½

-20cm.

36. A method according to 20, further comprising the steps of:

one or more radiation emitters transmitting electromagnetic radiation into the transmissive element and toward the first surface thereof,and

preventing radiation from traveling directly from the emitters to the detector.

37. A method according to claim 20, further comprising the step of sensing a force applied by the reflecting/scattering element onto the transmissive element.

38. A method according to claim 21, further comprising the steps of:

providing a reflective element extending in a direction of the first surface part, and having a plurality of predetermined areas, the reflective element includes;

facilitating radiation transmission, in the areas, from the first surface part toward the second surface parts, and

reflecting, outside the areas, radiation traveling from the second surface part toward the first surface part back toward the second surface part.

39. A system for determining the a position of a radiation emitting/reflecting/scattering element, the system comprising:

a transmissive element or plate having a first surface part and a second surface part being opposite to the first surface part,

a first reflective element extending in a direction of the first surface part and having one or more predetermined areas, the reflective element being adapted to, in each area, provide radiation transmission from the first surface toward the second surface part and, outside the area(s), reflect radiation traveling from the second surface part toward the first surface back toward the second surface part,

a second reflective element extending in a direction of the first surface part and being adapted to reflect radiation traveling in the transmissive element from the first reflective element toward the second surface part back toward the first surface part and the first reflective element,

a detector, the detector being at least one at least one-dimensional detector having a plurality of detecting elements each being adapted to detect radiation and to output a corresponding signal,

at least one aperture, pinhole, or lens arranged between the transmissive plate and the detector and adapted to modulate radiation incident on the detecting elements, the detector being adapted to;

detect radiation from the emitting/reflecting/scattering element, which radiation has entered the transmissive element, passed through an area of the first reflective element and has been reflected toward the detector by the first and second reflective element, and

output a signal relating to an angle of incidence of the radiation, to a determining element adapted to determine, on the basis of the angle signal, a position of the emitting/reflecting/scattering element in relation to the first surface part.

40. A system according to claim 39, further comprising a radiating element adapted to provide radiation towards the emitting/reflecting/scattering element.

41. A method of determining a position of a radiation emitting/reflecting/scattering element, the method comprising:

providing a transmissive element or plate having a first surface part and a second surface part being opposite to the first surface part,

providing a first reflective element extending in a direction of the first surface part, and having a plurality of predetermined areas,

providing a second reflective element extending in a direction of the first surface part,

providing a detecting means including at least one at least one-dimensional detector having a plurality of detecting elements each being adapted to detect radiation and to output a corresponding signal,

receiving radiation from the emitting/reflecting/scattering element into the transmissive element, through an area, and toward the second reflective element,

the first and second reflective elements subsequently reflecting at least part of the received radiation toward the detecting means,

modulating radiation incident on the detecting elements with at least one aperture, pinhole, or lens arranged between the transmissive element and the detecting means,

detecting modulated radiation and outputting a signal relating to an angle of incidence of the radiation, and

determining, on the basis of the angle signal, a position of the emitting/reflecting/scattering element in relation to the first surface part.

42. A method according to claim 41, the method further comprising the step of providing radiation toward the emitting/reflecting/scattering element.