Sealed force-based touch sensor

• US 20040156168A1
• Filed: 02/12/2003
• Published: 08/12/2004
• Est. Priority Date: 02/12/2003
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: LeVasseur, Lewis H., Ng, Chin Y., Cobian, Paul J., Bartz, Sherman L., Tran, Hung T.
• Granted Patent: US 8,488,308 B2
• Time in Patent Office: Days
• US Class Current: 361/681
• CPC Class Codes: G06F 3/0414 using force sensing means to determine a position

Abstract

The present invention provides a display seal for a force-based sensor assembly that includes a flexible membrane having inner and outer surfaces, and first and second sides. The first side of the membrane is capable of being mounted to a housing of the assembly, such as a frame or bezel, and the second side of the membrane is capable of being mounted to a touch surface of a touch sensitive structure of the assembly. The seal, when mounted to the housing and the screen, is capable of creating a seal around the screen without passing extraneous forces to the transducers.

Claims

1. A force-based touch sensor assembly comprising a frame, a screen having inner and outer surfaces, a seal for inhibiting passage between the frame and the screen, and a force activated transducer positioned adjacent the screen for detecting forces pushing through the screen due to a touch input, the seal comprising:

a flexible membrane having first and second surfaces and first and second sides, the first side capable of being mounted to the frame, and the second side capable of being mounted to the screen;

whereby the membrane is configured and arranged so that mounting the membrane to the frame and screen creates the seal without passing extraneous forces to the transducers.

2. The assembly of claim 1, wherein the second side of the membrane is capable of being mounted to the outer surface of the screen.

3. The assembly of claim 1, wherein the second side of the membrane is capable of being mounted to the inner surface of the screen.

4. The assembly of claim 1, wherein the frame comprises outer and inner surfaces, and the second side of the membrane is capable of being mounted to the outer surface of the frame.

5. The assembly of claim 1, wherein the frame comprises outer and inner surfaces, and the second side of the membrane is capable of being mounted to the inner surface of the frame.

6. The assembly of claim 1, wherein the display further comprises a bezel, and the second side of the membrane is further capable of being mounted to the bezel thereby creating a seal between the bezel and the outer surface of the screen.

7. The assembly of claim 1, wherein the first surface at the first side of the membrane is secured to the outer surface of the screen, and the second surface at the second side of the membrane is secured to the frame.

8. The assembly of claim 1, wherein the membrane, when mounted to the screen and frame, includes a bend section.

9. The assembly of claim 1, wherein the first and second sides of the membrane are brought together so as to form a cylindrical shaped seal, and the cylindrically shaped seal is capable of being secured to the frame and the outer surface of the screen to form the seal.

10. The assembly of claim 1, wherein the seal is a continuous, uninterrupted piece configured to extend around a periphery of the screen.

11. A self-contained force-based touch sensor assembly, comprising;

a frame having inner and outer surfaces;

a screen having inner and outer surfaces;

a transducer positioned to sense forces passing through the screen due to touch inputs on the screen;

a spring positioned between the inner surface of the frame and the screen to exert a pre-load force between the screen and the transducer;

a membrane having first and second surfaces and first and second sides, the membrane being mounted to the screen and to the frame, the membrane being capable of forming a complete seal between the frame and the screen.

12. The assembly of claim 11, wherein the transducer is positioned between the inner surface of the frame and the outer surface of the screen.

13. The assembly of claim 11, wherein the transducer is positioned between the inner surface of the frame and the inner surface of the screen.

14. The assembly of claim 12, wherein the spring is positioned between the inner surface of the frame and the outer surface of the screen.

15. The assembly of claim 13, wherein the spring is positioned between the inner surface of the frame and the inner surface of the screen.

16. The assembly of claim 11, wherein the membrane is a single molded piece.

17. A method of assembling a force-based touch sensor assembly, the assembly comprising a frame, a screen having first and second surfaces, and a sealing membrane having first and second sides and first and second surfaces, the method comprising the steps of:

retaining the screen within boundaries of the frame;

securing the first side of the membrane to the screen;

securing the second side of the membrane to the frame;

whereby the membrane, when mounted to the frame and screen, is capable of creating a seal between the frame and the screen so as to inhibit passage of foreign objects to an area between the frame and the inner surface of the screen.

18. A method of dissipating bezel forces in a force-based touch display assembly, the display assembly comprising a bezel, a display screen, a display frame, and a sensor assembly having a sensor screen and a sensor frame, the method comprising the steps of:

positioning the display screen adjacent the display frame, the sensor assembly adjacent the display, and the bezel adjacent the sensor assembly;

whereby an external force applied to the bezel is translated to the sensor frame and the system frame such that a threshold input to the sensor screen is not exceeded.

19. The method of claim 18, further comprising the step of sealing the display assembly with a membrane that provides a liquid and particle seal around the screen to promote essentially unrestricted motion of the screen without passing extraneous forces to the screen that result in false touches to the screen or skewing of touch location determination of intended touches to the screen

20. A method of producing a seal member for a force-based touch sensor assembly, comprising:

aligning strips of seal membrane in a shape that approximates a periphery of a touch sensitive structure of the force-based touch sensor assembly; and

securing the strips of seal membrane together to form a continuous seal member;

whereby the seal member is configured so as to be capable of being secured to the touch sensitive structure and a frame of the forced-based touch sensor assembly to form a complete seal between the touch sensitive structure and the frame.

21. The method of claim 20, wherein the strips of seal membrane are secured together by bonding.

22. The method of claim 20, wherein two of the strips of seal membrane are simultaneously cut to a predetermined length and secured together in a single step.

23. The method of claim 20, further comprising the step of forming strips of seal membrane from material selected from a group of materials consisting of polyethylene, polypropylene, polyurethane, polyamide, fluoropolymer or polyvinylchloride.

24. A self-contained force-based touch sensor assembly, comprising:

a frame;

a touch sensitive structure mounted to the frame;

a transducer positioned between the touch sensitive structure and the frame; and

a seal member secured to the frame and the touch sensitive structure to form a complete seal between the frame and the touch sensitive structure;

whereby the assembly is capable of being mounted to an existing display assembly to make the display assembly sensitive to touch inputs.

25. A seal for a force-based touch sensor assembly, the assembly comprising a frame, a touch sensitive structure, a seal, and a force activated transducer associated with the touch sensitive structure, the seal comprising:

a continuous piece of compliant material secured to the touch sensitive structure and the frame, the compliant material being configured such that a maximum force exerted upon the touch sensitive structure by the compliant material is an order of magnitude less or smaller than a minimum recognized touch input force to the touch sensitive structure.

26. The seal of claim 25, wherein the maximum force exerted upon the touch sensitive structure by the compliant material is {fraction (1/50)} or less of a minimum recognized touch input force to the touch sensitive structure.

27. The seal of claim 25, wherein the seal is configured such that the seal can be compressed without triggering a false touch input due to forces being transferred from the compliant material and the touch sensitive structure.

28. A force-based touch display device, comprising:

a housing;

a movable force-based touch sensitive screen;

a sealing means adapted and configured to provide a liquid and particle seal between the screen and the housing, and to promote essentially unrestricted motion of the screen without passing extraneous forces to the screen that result in false touches to the screen or skewing of touch location determination of intended touches to the screen.

29. The device of claim 28, wherein the housing is a frame for the screen.

30. The device of claim 28, wherein the housing is a bezel for the device.

31. The device of claim 28, wherein the sealing means is a continuous, uninterrupted membrane.

32. The device of claim 28, further comprising a reference surface positioned adjacent the screen, wherein the sealing means forms a seal between the screen and the reference surface.

33. The device of claim 28, wherein the sealing means includes a bend section when secured to the screen and the frame or bezel, the bend section being configured to promote essentially unrestricted motion of the screen.

34. The device of claim 28, wherein the sealing means has a C-shaped cross-section.

35. The device of claim 28, wherein the sealing means has a closed cross-section.

36. The device of claim 28, wherein the sealing means is adapted and configured to provide lateral-stiffening support to the screen.

37. The device of claim 28, wherein the sealing means is a polymeric material.

38. The device of claim 28, wherein the sealing means is a compliant foam material.

39. The device of claim 28, wherein the membrane is a composite material.

40. A force-based touch sensor assembly comprising a bezel, a screen having inner and outer surfaces, a seal, and a force activated transducer positioned adjacent the screen for detecting forces pushing through the screen due to a touch input, the seal comprising:

a flexible membrane having first and second surfaces and first and second sides, the first side capable of being mounted to the bezel, and the second side capable of being mounted to the screen;

whereby the membrane is configured and arranged so that the membrane, when mounted to the bezel and screen, creates a seal between the bezel and the screen without passing extraneous forces to the transducers.