Touchscreen for detecting multiple touches

• US 8,243,048 B2
• Filed: 04/25/2007
• Issued: 08/14/2012
• 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): TRAN, MY CHAU T
• Application Number:
  US11/789,776
• Publication Number:
  US 20080266266A1
• Time in Patent Office: 1,938 Days
• Field of Search: 345/156, 345/173, 345/177, 178/18.01, 178/18.03, 178/18.04
• US Class Current: 345/177
• 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;

wherein the at least one transmitter is a surface acoustic wave (SAW) transmitter and the receivers are SAW receivers.

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 2, further comprising receive beam splitters positioned proximate to the receivers for deflecting the at least second and third beams with respect to the receivers.

4. The system of claim 2, wherein the at least one transmitter is one of an array of transmitters transmitting the first beams and the receivers are correspondingly positioned opposite the transmitters.

5. The system of claim 4, further comprising receive beam splitters positioned proximate to the receivers for deflecting the at least second and third beams with respect to the receivers.

6. The system of claim 4, wherein the plurality of deflecting elements comprises screen printed glass frit material.

7. The system of claim 4, wherein the plurality of deflecting elements comprises composite polymer material ink.

8. The system of claim 4, wherein the plurality of deflecting elements comprises etched grooves.

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

10. The system of claim 9, wherein the at least one transmitter comprises a transmit transducer and a first array proximate to the outer edges of the touch area, wherein the at least one transmitter is configured to deflect in the second direction the first beams towards the at least one beam splitter.

11. The system of claim 10, wherein one of the at least second and third beams travels through the touch area along one of an X or Y direction, wherein the other of the at least second and third beams travels in a U direction at a diagonal angle.

12. The system of claim 10, further comprising receive beam splitters positioned proximate to the receivers for deflecting the at least second and third beams with respect to the receivers.

13. The system of claim 10, wherein the plurality of deflecting elements comprises screen printed glass frit material.

14. The system of claim 10, wherein the plurality of deflecting elements comprises composite polymer material ink.

15. The system of claim 10, wherein the plurality of deflecting elements comprises etched grooves.

16. The system of claim 12, wherein at least one of the receivers comprises a receive transducer and a second array proximate to the outer edges of the touch area, wherein the at least one of the receivers is configured to deflect the other of the at least second and third beams from the U direction.