TOUCH SCREEN RENDERING SYSTEM AND METHOD OF OPERATION THEREOF

• US 20120026124A1
• Filed: 07/31/2010
• Published: 02/02/2012
• Est. Priority Date: 07/31/2010
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: LI, Hao, WEI, Yi, YOUNG, Steven
• Granted Patent: US 8,963,874 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49004 including measuring or testing of device or component part
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

A touch-screen display apparatus, the apparatus may include first and second sheets having opposed major surfaces and a size and shape defined by a periphery. The periphery may be defined by opposed ends and opposed edges. The first and second sheets may each have a conductive pattern including a pair of opposed busbars and a plurality of traces electrically coupled to, and extending between, corresponding pairs of opposed busbars. The transparent force sensing (TFS) sheet may have opposed major surfaces and a variable resistance which is related to a force exerted upon one or more of its major surfaces. The TFS sheet may be situated between the first and second sheets. The apparatus may also include one or more separation portions situated between the TFS sheet and the first or second sheet to bias the TFS sheet apart from the first or second sheet.

Claims

1. A touch panel (TP) display apparatus having a user interface (UI) with which a user may interact with the panel, the apparatus comprising:

first and second sheets, each having opposed major surfaces and corresponding peripheries defined by opposed ends and opposed edges, the first and second sheets each having a conductive pattern comprising a pair of opposed busbars electrically coupled to corresponding ones of the first and second sheets;

a transparent force sensing (TFS) sheet having opposed major surfaces and a variable resistance, situated between the first and second sheets; and

separation portions situated between the TFS sheet and the first or second sheet to bias the TFS sheet apart from the first or second sheet.

2. The apparatus of claim 1, wherein the opposed pairs of busbars are selectively coupled to one or more of a voltmeter, a voltage source, an analog-to-digital (A/D) converter, and a digital-to-analog (D/A) converter by a control portion.

3. The apparatus of claim 1, further comprising a control portion comprising a processor configured to determine a location of force and a magnitude of the force applied to the UI of the TP, the processor coupled to one or more of the voltmeter, the voltage source, the analog-to-digital (A/D) converter, and the digital-to-analog (D/A) converter.

4. The apparatus of claim 1, further comprising a transparent protective layer superimposed upon a major surface of the first or second sheets.

5. The apparatus of claim 1, wherein the busbars of the first major sheet extend between the opposed edges and are proximate to an adjacent end of the opposed ends of the first major sheet.

6. The apparatus of claim 1, wherein the opposed pairs of busbars of the first sheet to be substantially perpendicular to the opposed pair of busbars of the second sheet.

7. The apparatus of claim 1, further comprising a transparent substrate upon which the upon which a major surface of the first or second sheets is attached.

8. A method of forming a touch panel (TP) display apparatus having a user interface (UI) with which a user may interact, the method comprising acts of:

forming first and second sheets, each having opposed major surfaces and corresponding peripheries defined by opposed ends and opposed edges, the first and second sheets each having a conductive pattern comprising a pair of opposed busbars electrically coupled to corresponding ones of the first and second sheets;

positioning a transparent force sensing (TFS) sheet between the first and second sheet, the TFS sheet having opposed major surfaces and a variable resistance across the opposed major surfaces;

biasing the first or second sheets apart from the TFS sheet using separation portions situated between the TFS sheet and the first or second sheet.

9. The method of claim 8, further comprising an act of electronically coupling the opposed pairs of busbars to one or more of a voltmeter, a voltage source, an analog-to-digital (A/D) converter, and a digital-to-analog (D/A) converter.

10. The method of claim 8, further comprising an act of coupling a control portion having a processor configured to determine a location of force and a magnitude of force to one or more of the voltmeter, the voltage source, the analog-to-digital (A/D) converter, and the digital-to-analog (D/A) converter.

11. The method of claim 8, further comprising an act of placing a transparent protective layer upon a major surface of the second major sheet.

12. The method of claim 8, wherein the busbars of the first major sheet extend between the opposed edges and are proximate to an adjacent end of the opposed ends of the first major sheet.

13. The method of claim 8, further comprising an act of configuring the opposed pairs of busbars of the first sheet to be substantially perpendicular to the opposed pair of busbars of the second sheet.

14. The method of claim 8, further comprising an act of superposing a substrate to upon a major surface of the first or second sheets.

15. A method of operating a touch panel (TP) using a controller, the method comprising acts of:

applying a predetermined voltage across a first end of a first conductive pattern having first and second ends on a first layer and a second end of a second conductive pattern electrically coupled to the first conductive pattern via a resistance (Rt), the second conductive pattern having first and second ends on a second layer;

determining a resistance (Rx) across the first and second ends of the first conductive pattern;

determining a first voltage (V1) at the second end of the first conductive pattern;

determining a second voltage (V2) at the first end of the second conductive pattern;

determining a value of Rt based upon V1, V2, and Rx; and

producing a control signal based on the determined value of Rt.

16. The method of claim 15, further comprising an act of determining a magnitude of a force applied to the first or second layers of the TP based upon a value of Rt.

17. The method of claim 15, further comprising acts of:

applying a voltage (Vcc2) across the first and second ends of a first one of the first or second conductive pattern;

measuring a voltage (V3) at the second end of a second one of the first or second conductive patterns; and

is determining a coordinate of a force applied to the first or second layers of the TP based upon a ratio of V3 to Vcc2.

18. The method of claim 15, wherein the resistance Rt comprises a variable resistance across a transparent force sensing (TFS) sheet interposed between the first and second layers.

19. A computer program stored on a computer readable persistent memory medium, the computer program configured to operate a touch panel (TP) of a user interface (UI), the computer program comprising:

a program portion configured to;

apply a predetermined voltage across a first end of a first conductive pattern having first and second ends on a first layer and a second end of a second conductive pattern electrically coupled to the first conductive pattern via a resistance (Rt), the second conductive pattern having first and second ends on a second layer;

determine a resistance (Rx) across the first and second ends of the first conductive pattern;

determine a first voltage (V1) at the second end of the first conductive pattern;

determine a second voltage (V2) at the first end of the second conductive pattern;

determine a value of Rt based upon V1, V2, and Rx; and

produce a control signal based on the determined value of Rt.

20. The computer program of claim 19, wherein the program portion is configured to:

determine a magnitude of a force applied to the first or second layers of the TP based upon a value of Rt;

apply a voltage (Vcc2) across a first and second ends of the first or second conductive pattern;

measure a voltage (V3) at the second end of the other of the first or second conductive panels; and

determine a coordinate of the force based upon a ratio of V3 to Vcc2.