Stress-Limiting Device For Forced-Based Input Panels

• US 20090316380A1
• Filed: 05/20/2009
• Published: 12/24/2009
• Est. Priority Date: 05/20/2008
• Status: Abandoned Application

• Current Assignee: QSI Incorporated (Quanta Services Incorporated)
• Original Assignee: QSI Incorporated (Quanta Services Incorporated)
• Inventors: Armstrong, Stephen G.
• Application Number:
  US12/469,052
• Publication Number:
  US 20090316380A1
• Time in Patent Office: Days
• US Class Current: 361/829
• CPC Class Codes: G06F 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04142 the force sensing means being located peripherally, e.g. disposed at the corners or at the side of a touch sensing plate

Abstract

A system for preventing damage caused by the application of excessive force to a force-based input device having an input panel supported by a plurality of deflecting beam segments, in which the excessive force could cause permanent plastic deformation in the beam segments. The system includes a stress-limiting device operable about the deflecting beam segments to control the motion of the beam segments to within a pre-determined range.

Claims

1. A system for preventing damage to a force-based input device caused by the application of excessive force, comprising:

a force-based input device comprising an input panel supported by a plurality of beam segments, each of the plurality of beam segments having an end fixed relative to a chassis and a movable end coupled to the input panel;

sensing means that emit an electrical signal proportional to a deflection of the plurality of beam segments along a translational axis substantially perpendicular to the plane of the input panel; and

a stress-limiting device operable about the movable end of each of the plurality of beam segments to facilitate limited deflection of the beam segment within a pre-determined range.

2. The system of claim 1, wherein the stress-limiting device is configured to limit deflection of the moveable end of the beam segment in either direction along the translational axis.

3. The system of claim 1, wherein the stress-limiting device is configured to limit deflection of the moveable end of the beam segment in both directions along the translational axis.

4. The system of claim 3, wherein the stress-limiting device is configured to limit deflection in both directions non-symmetrically.

5. The system of claim 3, wherein the stress-limiting device further comprises a tongue and groove configuration.

6. The system of claim 5, wherein the beam segment is configured with a tongue portion of the stress-limiting device and the chassis is configured with a groove portion of the stress-limiting device.

7. The system of claim 1, wherein the stress-limiting device is adjustable to allow changes in the pre-determined range of deflection of the beam segments.

8. The system of claim 7, wherein the pre-determined range is adjustable with a set screw.

9. The system of claim 7, wherein the pre-determined range is adjustable with an insert.

10. The system of claim 1, wherein the stress-limiting device further comprises an energy-absorbent material to dampen out rebound resulting from the application of excessive force.

11. A system for preventing damage to a force-based input device caused by the application of excessive force, comprising

a force-based input device comprising an input panel flexibly supported within a surrounding frame by a plurality of beam segments, each of the plurality of beam segments further comprising:

a fixed end secured to the frame;

a movable end coupled to the input panel; and

a means for providing an electrical signal proportional to a deflection of the beam segments along a translational axis substantially perpendicular to the plane of the input panel; and

a stress-limiting device operable about the movable end of each of the plurality of beam segments to facilitate limited deflection of the beam segment within a pre-determined range.

12. The system of claim 11, wherein the stress-limiting device is configured to limit deflection of the moveable end of the beam segment in both directions along the translational axis.

13. The system of claim 12, wherein the stress-limiting device is configured to limit deflection in both directions non-symmetrically.

14. The system of claim 12, wherein the stress-limiting device further comprises a tongue and groove configuration.

15. The system of claim 14, wherein the beam segment is configured with a tongue portion of the stress-limiting device and the frame is configured with a groove portion of the stress-limiting device.

16. The system of claim 11, wherein the stress-limiting device is adjustable to allow changes in the pre-determined range of deflection of the beam segment.

17. The system of claim 11, wherein the stress-limiting device further comprises an energy-absorbent material to dampen out rebound resulting from the application of excessive force.

18. A method for preventing damage to a force-based input device caused by the application of excessive force, comprising:

obtaining a force-based input device comprising an input panel flexibly supported within a surrounding frame by a plurality of deflecting beam segments, each of the plurality of beam segments further comprising;

a fixed end secured to the frame;

a movable end coupled to the input panel; and

a means for providing an electrical signal in response to a deflection of the beam segment along a translational axis substantially perpendicular to the plane of the input panel;

limiting the deflection of the beam segment with a stress-limiting device to a pre-determined range of motion within the elastic range of the beam segment.

19. The method of claim 18, wherein limiting the deflection of the beam segment further comprises limiting the range of motion in both directions along the translational axis.

20. The method of claim 18, further comprising adjusting the stress-limiting device to change the pre-determined range of motion of the beam segment.