Touchscreen for detecting multiple touches

• US 20080266266A1
• Filed: 04/25/2007
• Published: 10/30/2008
• Est. Priority Date: 04/25/2007
• Status: Active Grant

• Current Assignee: Elo Touch Solutions, Inc.
• Original Assignee: Tyco Electronics Corporation (TE Connectivity Ltd. (United Kingdom))
• Inventors: Kent, Joel C., Aroyan, James L., Scharff, Daniel H., Gao, Ting, Tanaka, Yoshikazu
• Granted Patent: US 8,243,048 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• 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 touch area;

at least one transmitter positioned proximate to outer edges of the touch area for transmitting first beams in a first direction;

at least one beam splitter positioned proximate to the outer edges of the touch area for splitting the first beams into at least second and third beams traveling through the touch area in at least second and third directions, respectively, the at least one beam splitter comprising a plurality of deflecting elements; and

receivers positioned proximate to the outer edges of the touch area for receiving the at least second and third beams.

2. The system of claim 1, wherein one of the at least second and third directions is the same as the first direction.

3. The system of claim 1, wherein the at least second and third directions and the first direction are different with respect to each other.

4. The system of claim 1, wherein the at least one transmitter is an infrared (IR) transmitter and the receivers are IR receivers.

5. The system of claim 1, wherein the at least one transmitter is a surface acoustic wave (SAW) transmitter and the receivers are SAW receivers.

6. The system of claim 1, further comprising receive beam splitters positioned proximate to the receivers for deflecting the at least second and third beams with respect to the receivers.

7. The system of claim 1, wherein the at least one beam splitter comprises at least one lens, the at least one transmitter being associated with the at least one lens.

8. The system of claim 1, wherein the at least one transmitter is an IR transmitter and the receivers are IR receivers, wherein the touch area comprises X and Y directions that are 90 degrees different with respect to each other, wherein the second beam traveling through the touch area along one of the X and Y directions and the third beam traveling through the touch area at an approximately 45 degree angle with respect to the second beam.

9. The system of claim 1, wherein the at least one beam splitter comprises at least one lens, the at least one transmitter being associated with the at least one lens, the touch area comprising X and Y directions that are 90 degrees different with respect to each other, the at least one transmitter being further positioned to align one of the at least second and third directions with one of the X and Y directions.

10. The system of claim 1, wherein the at least one transmitter is associated with one deflecting element of the plurality of deflecting elements, the at least one transmitter being aligned with respect to the associated deflecting element.

11. The system of claim 1, wherein the at least one beam splitter comprises a front wall, wherein each deflecting element within the plurality of deflecting elements comprises at least one slanted facet, and wherein the first beams are IR beams that interface with the front wall of the beam splitter at an incident direction, the at least one slanted facet bending at least a portion of the first beam in a direction different than the incident direction.

12. The system of claim 1, wherein the plurality of deflecting elements are oriented to one of reflect and refract the beams.

13. The system of claim 1, wherein each deflecting element within the plurality of deflecting elements comprises at least one slanted facet being coated with reflective material, the at least one slanted facet bending at least a portion of the beams in a direction different than the first direction.

14. A touchscreen system, comprising:

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

a first X array and a first Y array being fabricated on the substrate proximate to outer edges of the touch area;

transmit transducers for transmitting beams through the first X and Y arrays, the first X and Y arrays deflecting the beams towards the touch area;

first and second beam splitters fabricated on the substrate between the first X and Y arrays, respectively, and the touch area, the first and second beam splitters each splitting the beams into at least two beams traveling through the touch area in different directions with respect to each other; and

receive transducers for receiving the at least two beams.

15. The system of claim 14, further comprising:

each of the first and second beam splitters comprising a top side and a bottom side, the bottom side interfacing with the substrate; and

a seal being formed at least along the top side of the first and second beam splitters.

16. The system of claim 14, further comprising:

a second X array and a second Y array being fabricated on the substrate proximate to the outer edges of the touch area; and

third and fourth beam splitters being fabricated on the substrate between the second X and Y arrays, respectively, and the touch area, the third and fourth beam splitters deflecting the at least two beams to travel toward the receive transducers.

17. The system of claim 14, wherein the first and second beam splitters each comprise a plurality of deflecting elements wherein each of the deflecting elements comprises a linear segment fabricated on the substrate.

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

transmitting first beams proximate to an outer edge of a touch area;

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

splitting the at least second and third beams traveling in different directions to form receive beams;

receiving the receive beams; and

detecting a location of at least one externally generated touch within the touch area based on the receive beams.

19. The method of claim 18, further comprising deflecting portions of the first beams towards the touch area as the first beams travel along the outer edges of the touch area.

20. The method of claim 18, further comprising deflecting the receive beams to travel along the outer edges of the touch area.