Surface acoustic wave touch panel and system of the same

• US 20060109261A1
• Filed: 09/14/2005
• Published: 05/25/2006
• Est. Priority Date: 09/14/2004
• Status: Abandoned Application

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Hwu, Keh-Long, Tien, Ching-Cheng, Chou, Yuan-Fang
• Application Number:
  US11/225,211
• Publication Number:
  US 20060109261A1
• Time in Patent Office: Days
• US Class Current: 345/177
• CPC Class Codes: G06F 3/0436 in which generating transducers and detecting transducers are attached to a single acoustic waves transmission substrate

Abstract

A surface acoustic wave touch panel and a system of the same are provided. The system includes the touch panel, an input/output (I/O) controlling unit, a detecting unit, and a signal processing unit. The touch panel includes a substrate on which at least one first emitter and at least one second emitter are provided on two adjacent edges thereof, and at least one first receiver and at least one second receiver are provided on the other two adjacent edges of the substrate. The I/O controlling unit controls the emitters to emit signals, and controls the detecting unit to pick up output signals from the receivers. The signal processing unit uses a neural network to determine an amplitude-reduction feature of any of the output signals so as to identify a position being touched on the touch panel. The touch panel is provided with high resolution and high throughput.

Claims

1. A system of surface acoustic wave touch panel, comprising:

a surface acoustic wave touch panel with a substrate, wherein at least one first emitter and at least one second emitter are formed on two adjacent edges of the substrate respectively, and at least one first receiver and at least one second receiver are respectively provided on edges of the substrate opposed to the edges with the first and second emitters, and wherein relation between the receiver number on one edge of the substrate to the emitter number on one edge of the substrate is multiple to multiple, multiple to one, or one to multiple;

an input/output (I/O) controlling unit for exciting the first and second emitters in a multiplex manner to emit surface acoustic waves, wherein the first and second receivers receive the surface acoustic waves emitted from the first and second emitters and convert the received surface acoustic waves into output signals, and when a particular position on the substrate of the touch panel is touched, the surface acoustic waves passing through this position are impeded and energy thereof is partially absorbed, making amplitude of the output signals reduced; and

a signal processing unit for processing the output signals from the first and second receivers via a neural network to detect any of the output signals having reduced amplitude so as to determine coordinates of the touched position on the touch panel.

2. The system of claim 1, wherein the signal processing unit further comprises:

a demodulating module for performing envelope detection on the output signals from the first and second receivers so as to output envelope signals;

an A/D converting module for sampling the envelope signals from the demodulating module and converting the sampling results into digital signals; and

a calculating module for processing the digital signals via the neural network to determine the coordinates of the touched position on the touch panel.

3. The system of claim 1, further comprising a detecting unit controlled by the I/O controlling unit to pick up the output signals from the first and second receivers in a multiplex manner, and for amplifying the output signals.

4. The system of claim 3, wherein when the relation between the receiver number on one edge of the substrate to the emitter number on an opposite edge of the substrate is multiple to multiple or multiple to one, the detecting unit amplifies the output signals from the first and second receivers in a multiplex manner and transmits the amplified output signals to the signal processing unit.

5. The system of claim 1, wherein the 1/O controlling unit controls duration of the exciting time for the first and second emitters.

6. The system of claim 1, wherein when the relation between the receiver number on one edge of the substrate to the emitter number on an opposite edge of the substrate is one to multiple, the signal processing unit determines the touched position on the touch panel via the neural network and according to relation between intensity and time of the output signals from the first and second receivers.

7. The system of claim 1, wherein when the relation between the receiver number on one edge of the substrate to the emitter number on an opposite edge of the substrate is multiple to multiple or multiple to one, the signal processing unit determines the touched position on the touch panel via the neural network and according to relation between intensity and spatial locations of the output signals from the first and second receivers.

8. The system of claim 1, wherein if two or more of the emitters or receivers are provided on one edge of the substrate, the two or more emitters or receivers are arranged as an array on the corresponding edge of the substrate.

9. The system of claim 8, wherein at least one trench is provided between two adjacent ones of the receivers to eliminate interference during signal receiving.

10. The system of claim 1, wherein if only one of the emitter or receiver is provided on one edge of the substrate, the single emitter or receiver is shaped as a strip on the corresponding edge of the substrate.

11. The system of claim 1, wherein the first and second emitters are substantially shaped as parallelogram on the edges of the substrate.

12. A surface acoustic wave touch panel, comprising:

a substrate;

at least one first emitter and at least one second emitter respectively formed on two adjacent edges of the substrate; and

at least one first receiver and at least one second receiver respectively made of piezoelectric films and respectively formed on edges of the substrate opposed to the edges with the first and second emitters, the first and second receivers being provided for receiving signals emitted from the first and second emitters, wherein relation between the receiver number on one edge of the substrate to the emitter number on one edge of the substrate is multiple to multiple, multiple to one, or one to multiple.

13. The surface acoustic wave touch panel of claim 12, wherein if two or more of the emitters or receivers are provided on one edge of the substrate, the two or more emitters or receivers are arranged as an array on the corresponding edge of the substrate.

14. The surface acoustic wave touch panel of claim 13, wherein at least one trench is provided between two adjacent ones of the receivers to eliminate interference during receiving of the signals.

15. The surface acoustic wave touch panel of claim 12, wherein if only one of the emitter or receiver is provided on one edge of the substrate, the single emitter or receiver is shaped as a strip on the corresponding edge of the substrate.

16. The surface acoustic wave touch panel of claim 12, wherein the first and second emitters are substantially shaped as parallelogram on the edges of the substrate.