Touch panels having plastic substrates

• US 6,087,599 A
• Filed: 11/24/1997
• Issued: 07/11/2000
• Est. Priority Date: 11/24/1997
• Status: Expired due to Fees

• Current Assignee: The Whitaker Corporation (Meggitt PLC)
• Original Assignee: The Whitaker Corporation (Meggitt PLC)
• Inventors: Knowles, Terence J.
• Primary Examiner(s): Shankar, Vijay
• Assistant Examiner(s): Said, Mansour M.
• Application Number:
  US08/977,095
• Time in Patent Office: 960 Days
• Field of Search: 345/173, 345/177, 345/179, 345/156, 178/18.01, 178/18.04, 178/18.03, 178/19.01, 178/19.02, 178/19.03
• US Class Current: 178/18.04
• CPC Class Codes: G06F 3/0436 in which generating transducers and detecting transducers are attached to a single acoustic waves transmission substrate

Abstract

The present invention is directed to a touch panel for use in a touch position sensor. The touch panel includes a substrate fabricated at least partially from plastic materials. The plastic may be a polystyrene and/or copolymers of polystyrene. The touch panel utilizes transverse acoustic waves having a frequency in the range of 0.2 to 2.0 Megahertz to detect a touch on the touch panel.

Claims

1. A touch panel for use in a touch position sensor, comprising:

a substrate of polystyrene having four edges and a thickness chosen to support transverse acoustic waves;

at least one transducer disposed on two of said edges, each transducer for transmitting transverse acoustic waves having a frequency in the range of about 0.2 to 2.0 Megahertz to and receiving transverse acoustic waves having a frequency in the range of about 0.2 to 2.0 Megahertz from the substrate; and

selectively disposed reflective arrays for reflecting a portion of said transverse acoustic waves.

2. A touch panel as recited in claim 1 were in said substrate has a thickness which will not support surface acoustic waves.

3. A touch panel as recited in claim 1 were in said transverse acoustic zeroth order horizontally polarized shear waves.

4. A touch panel as recited in claim 1 wherein said reflective arrays are gratings disposed peripherally about said substrate.

5. A touch panel as recited in claim 1, wherein said substrate has a hard coat material disposed thereon.

6. A touch panel for use in a touch position sensor, comprising:

a substrate of polystyrene having four edges and a thickness chosen to support transverse acoustic;

at least one transducer selectively disposed on each of said edges, each transducer for transmitting transverse acoustic waves having a frequency in the range of about 0.2 to 2.0 Megahertz to or receiving transverse acoustic waves having a frequency in the range of about 0.2 to 2.0 Megahertz from the substrate.

7. A touch panel as recited in claim 6 wherein transducers on a first edge of said substrate are coupled selectively to transducers on a second edge of said substrate and transducers disposed on a third on said substrate are coupled selectively to transducers on a forth edge to effect the transmission and reception of transverse acoustic waves.

8. A touch panel as recited in claim 6 where in said substrate has a thickness which will not support surface acoustic waves.

9. A touch panel as recited in claim 6 where in said transverse acoustic waves are zeroth order horizontally polarized shear waves.

10. A touch panel as recited in claim 6 where in said transducers are lead-zirconium.