Acoustic wave touch detecting apparatus

• US 20050035685A1
• Filed: 11/12/2003
• Published: 02/17/2005
• Est. Priority Date: 11/13/2002
• Status: Active Grant

• Current Assignee: Elo Touch Solutions, Inc.
• Original Assignee: Elo Touchsystems Incorporated (Elo Touch Solutions, Inc.)
• Inventors: Dews, Christopher, Scharff, Daniel, Tanaka, Yoshikazu
• Granted Patent: US 6,948,371 B2
• Time in Patent Office: Days
• US Class Current: 310/313.D
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0436 in which generating transducers and detecting transducers are attached to a single acoustic waves transmission substrate
• CPC Class Codes: H05K 1/0219 Printed shielding conductors for shielding around or between signal conductors, e.g. coplanar or coaxial printed shielding conductors
• CPC Class Codes: H05K 1/189 characterised by the use of a flexible or folded printed circuit H05K3/326 takes precedence
• CPC Class Codes: H05K 2201/09236 Parallel layout layout of balanced signal pairs H05K1/0245; superposed layout H05K2201/09672

Abstract

An FPC is constructed of two FPC branches, and a connection line that connects to a controller. Printed wiring of the connection line includes ten printed wires. The central four printed wires are signal reception wires, which are connected to two converters (sensors). Grounding wires are provided on both sides of the four signal reception wires. Two outer signal wires are provided adjacent to the grounding wires, respectively toward the outsides thereof. Further, two more grounding wires are provided adjacent to the outer signal wires, respectively on the outsides thereof. This construction results in shielding of all of the signal wires. This relationship is maintained in the FPC branches as well.

Claims

1. An acoustic wave contact detecting apparatus comprising:

a substrate having a surface along which acoustic waves propagate;

an acoustic wave generating means;

a reflection array for causing the generated acoustic waves to propagate along the surface of the substrate;

a detector for detecting changes in the acoustic wave caused by an object contacting the surface of the substrate; and

a controller for determining the geometric coordinates of the object;

wherein;

at least one of the acoustic wave generating means and the detector are connected the controller by flexible planar wiring; and

the flexible planar wiring is of a wiring pattern in which a grounding wire is provided on at least one side of a signal wire.

2. An acoustic wave contact detecting apparatus as defined in claim 1, wherein:

the flexible planar wiring comprises;

a signal wire group in which a plurality of the signal wires are arranged; and

grounding wires at both sides of the signal wire group.

3. An acoustic wave contact detecting apparatus comprising:

a substrate having a surface along which acoustic waves propagate;

a transmission side converter mounted on the substrate;

a mode converting element for converting bulk waves generated by the converter into acoustic waves, mounted on the surface of the substrate corresponding to the converter;

a reflection array for causing the generated acoustic waves to propagate along the surface of the substrate;

a detector for detecting changes in the acoustic wave caused by an object contacting the surface of the substrate; and

a controller for determining the geometric coordinates of the object;

wherein;

at least one of the converter and the detector are connected the controller by flexible planar wiring; and

the flexible planar wiring is of a wiring pattern in which a grounding wire is provided on at least one side of a signal wire.

5. An acoustic wave contact detecting apparatus as defined in claim 3, wherein:

the substrate further comprises an inclined surface at an edge thereof; and

the converter is mounted on the inclined surface.

7. An acoustic wave contact detecting apparatus as defined in claim 3, wherein:

the flexible planar wiring is a flexible printed circuit (FPC).

8. An acoustic wave contact detecting apparatus as defined in claim 5, wherein:

the flexible planar wiring is a flexible printed circuit (FPC).

9. An acoustic wave contact detecting apparatus as defined in claim 3, wherein:

the flexible planar wiring is a flexible flat cable (FFC).

10. An acoustic wave contact detecting apparatus as defined in claim 3, wherein:

the flexible planar wiring is a flexible flat cable (FFC).

4. An acoustic wave contact detecting apparatus comprising:

a substrate having a surface along which acoustic waves propagate;

a transmission side converter mounted on the substrate;

a mode converting element for converting bulk waves generated by the converter into acoustic waves, mounted on the surface of the substrate corresponding to the converter;

a reflection array for causing the generated acoustic waves to propagate along the surface of the substrate;

a detector for detecting changes in the acoustic wave caused by an object contacting the surface of the substrate; and

a controller for determining the geometric coordinates of the object;

wherein;

at least one of the converter and the detector are connected to the controller by a bifilar wire; and

the bifilar wire is that in which a grounding wire is provided adjacent to a signal wire.

6. An acoustic wave contact detecting apparatus as defined in claim 4, wherein:

the substrate further comprises an inclined surface at an edge thereof; and

the converter is mounted on the inclined surface.