Touchscreen for detecting multiple touches

• US 9,454,266 B2
• Filed: 07/16/2012
• Issued: 09/27/2016
• Est. Priority Date: 04/25/2007
• Status: Active Grant

• Current Assignee: Elo Touch Solutions, Inc.
• Original Assignee: Elo Touch Solutions, Inc.
• Inventors: Kent, Joel C., Aroyan, James L., Gao, Ting, Tanaka, Yoshikazu, Scharff, Daniel H.
• Primary Examiner(s): Boddie, William
• Assistant Examiner(s): EARLES, BRYAN E
• Application Number:
  US13/550,063
• Publication Number:
  US 20120280942A1
• Time in Patent Office: 1,534 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G06F 3/0436 in which generating transducers and detecting transducers are attached to a single acoustic waves transmission substrate

Abstract

A touchscreen system comprises a touch area. At least one transmitter is positioned proximate to outer edges of the touch area for transmitting first beams in a first direction. At least one beam splitter is positioned proximate to the outer edges of the touch area for splitting the first beams into at least second and third beams that travel through the touch area in at least second and third directions, respectively. The at least one beam splitter comprises a plurality of deflecting elements. Receivers are positioned proximate to the outer edges of the touch area for receiving the at least second and third beams.

Claims

1. A touchscreen system comprising:

a substrate comprising a touch area having X and Y dimensions;

a first beam splitter positioned proximate to an outer edge of the X dimension of the touch area and configured to split a first beam into at least a first X beam and a second X beam, wherein the first X beam and the second X beam travel through the touch area in different directions with respect to each other, and the first X beam or the second X beam travels in the same direction as and parallel to the first beam;

a second beam splitter positioned proximate to an outer edge of the Y dimension of the touch area and configured to split a second beam into at least a first Y beam and a second Y beam, wherein the first Y beam and the second Y beam travel through the touch area in different directions with respect to each other; and

receive sensors configured to receive the first X beam, second X beam, first Y beam, and second Y beam and to determine locations of multiple touches on the touch area.

2. The touchscreen system of claim 1, wherein each of the first and second beam splitters comprises a top side and a bottom side, the bottom side interfacing with the substrate, and further comprising a seal being formed at least along the top side of the first and second beam splitters.

3. The touchscreen system of claim 1, wherein the first beam splitter is configured to cause one of the first X beam or the second X beam to travel through the touch area along an X direction and cause the other of the first X beam or the second X beam to travel through the touch area in a U direction at a diagonal angle.

4. The touchscreen system of claim 1, wherein each of the first and second beam splitters comprises a linear segment fabricated on the substrate.

5. The touchscreen system of claim 1, wherein the first beam splitter is configured to split the first beam into a third X beam that travels through the touch area in a different direction with respect to the first X beam and the second X beam such that:

the first X beam travels through the touch area along an X direction,

the second X beam travels through the touch area in a U direction at a diagonal angle, and

the third X beam travels through the touch area in a V direction at another diagonal angle.

6. The touchscreen system of claim 5, wherein the first beam splitter or the second beam splitter comprises a superposition of two or more pluralities of deflecting elements, the two or more pluralities of deflecting elements having different respective orientations.

7. The touchscreen system of claim 1, wherein the first beam splitter or the second beam splitter comprises screen printed glass frit material.

8. The touchscreen system of claim 1, wherein the first beam splitter or the second beam splitter comprises composite polymer material ink.

9. The touchscreen system of claim 1, wherein the first beam splitter or the second beam splitter comprises etched grooves.

16. The touchscreen system of claim 1, wherein the second X beam and the second Y beam are parallel.

17. The touchscreen system of claim 3, wherein the diagonal angle is 45 degrees.

18. The touchscreen system of claim 5, wherein the U direction and the V direction are orthogonal.

19. The touchscreen system of claim 1, further comprising:

an X array positioned proximate to the outer edge of the X dimension of the touch area and configured to deflect the first beam transmitted through the X array towards the touch area;

a Y array positioned proximate to the outer edge of the Y dimension of the touch area and configured to deflect the second beam transmitted through the Y array towards the touch area;

a first transmitter configured to transmit the first beam through the X array; and

a second transmitter configured to transmit the second beam through the Y array.

20. The touchscreen system of claim 1, further comprising:

a first transmitter configured to transmit the first beam towards the first beam splitter; and

a second transmitter configured to transmit the second beam towards the second beam splitter.

21. The touchscreen system of claim 20, wherein the first and second transmitters are configured to transmit IR wave energy.

22. The touchscreen system of claim 21, wherein:

the first transmitter comprises the first beam splitter; and

the second transmitter comprises the second beam splitter.

23. The touchscreen system of claim 22, wherein each of the first and second beam splitters comprises a non-focusing concave lens.

24. The touchscreen system of claim 22, wherein each of the first and second beam splitters comprises a non-focusing convex lens.

25. The touchscreen system of claim 21, wherein each of the first and second beam splitters comprises a diffraction grating.

26. The touchscreen system of claim 21, wherein each of the first and second beam splitters comprises an array of notches.

27. The touchscreen system of claim 26, wherein each notch in the array of notches is associated with each of the first and second transmitters.

28. The touchscreen system of claim 26, wherein the array of notches comprises a plurality of notches each spaced so that the first or second beam from the first or second transmitter, respectively, produces the X or Y deflected and the X or Y undeflected beam independent of where the first or second transmitter is placed.

29. The touchscreen system of claim 21, wherein each of the first and second beam splitters comprises a refractive beam splitter.

30. The touchscreen system of claim 21, wherein each of the first and second beam splitters comprises a reflective beam splitter.

31. The touchscreen system of claim 21, wherein:

the first transmitter is positioned perpendicular to the first beam splitter; and

the second transmitter is positioned perpendicular to the second beam splitter.

32. The touchscreen system of claim 21, wherein:

the first beam splitter comprises an incoming or outgoing surface tilted with respect to the first transmitter; and

the second beam splitter comprises an incoming or outgoing surface tilted with respect to the second transmitter.

33. The touchscreen system of claim 21, wherein the first beam splitter is positioned to intercept a portion of the first beam transmitted by the first transmitter, and wherein another portion of the first beam bypasses the first beam splitter.

34. The touchscreen system of claim 1, wherein the first X and Y beams are positioned perpendicular to each other and the second X beam and second Y beam are offset with respect to the first X beam, the first Y beam, and each other.

35. The touchscreen system of claim 1, wherein at least one of the first X beam and first Y beam is unprocessed by the sensors.

36. The touchscreen system of claim 1, further comprising:

a first deflective array positioned parallel to the first beam splitter and configured to receive the first beam and deflect the first beam at a first angle into the first beam splitter; and

a second deflective array positioned parallel to the second beam splitter and configured to receive the second beam and deflect the second beam at a second angle into the second beam splitter.

37. The touchscreen system of claim 36, wherein the first deflective array is configured to deflect the first beam into the first beam splitter at approximately a 90°

angle and the second deflective array is configured to deflect the second beam into the second beam splitter at approximately a 90°

angle.

38. The touch screen system of claim 36, further comprising:

a third deflective array positioned parallel to the first beam splitter and across the touch area from the first deflective array and configured to deflect the first X beam or the second X beam at an angle into one of the receive sensors; and

a fourth deflective array positioned parallel to the second beam splitter and across the touch area from the second deflective array and configured to deflect the first Y beam or the second Y beam at an angle into one of the receive sensors.

39. The touch screen system of claim 38, further comprising:

a third beam splitter positioned parallel to the third deflective array and between the third deflective array and the touch area and configured to receive the first X beam or the second X beam and propagate the first X beam or the second X beam to the third reflective array.

10. A method for detecting multiple touches on a touchscreen system, the method comprising:

transmitting a first beam and a second beam proximate to outer edges of a touch area;

splitting the first beam to form at least a first X beam and a second X beam traveling in different directions through a touch area with respect to each other, wherein the first X beam or the second X beam travels in the same direction as and parallel to the first beam;

splitting the second beam to form at least a first Y beam and a second Y beam traveling in different directions through the touch area with respect to each other;

receiving, via at least one receiver, the first and second X beams and the first and second Y beams; and

detecting a location of at least two externally generated touches within the touch area based on the first and second X beams and the first and second Y beams.

11. The method of claim 10, further comprising:

deflecting the first and second X beams and the first and second Y beams to travel along the outer edges of the touch area.

12. The method of claim 10, wherein the splitting the first beam comprises directing the first X beam in an X direction and the second X beam in a U direction at a diagonal angle.

13. The method of claim 10, wherein the splitting the first beam comprises splitting the first beam to form a third X beam traveling in a V direction at a diagonal angle.

14. A touchscreen system comprising:

a first transmitter configured to transmit an X beam;

a second transmitter configured to transmit a Y beam;

a first beam splitter, fabricated proximate to a touch screen area, configured to split the X beam into at least a first X beam and a second X beam that travel through the touch area in different directions with respect to each other, and wherein the first X beam or the second X beam travels in the same direction as and parallel to the first beam;

a second beam splitter, fabricated proximate to the touch screen area, configured to split the Y beam into at least a first Y beam and a second Y beam that travel through the touch area in different directions with respect to each other; and

a sensor configured to receive the first and second X beams and the first and second Y beams and to determine locations of multiple touches on the touch area.

15. The touchscreen system of claim 14, further comprising:

a controller configured to determine the locations of the multiple touches based on two or more attenuations of the first and second X beams and the first and second Y beams that travel through the touch area.