Pressure sensitive surfaces

• US 7,077,009 B2
• Filed: 01/28/2004
• Issued: 07/18/2006
• Est. Priority Date: 06/28/2001
• Status: Expired due to Fees

• Current Assignee: Johnny Jay Jackson
• Original Assignee: Tactex Controls Inc.
• Inventors: Alexander, Sathya R., Lokhorst, David M.
• Primary Examiner(s): Lefkowitz, Edward
• Assistant Examiner(s): JENKINS, JERMAINE L
• Application Number:
  US10/765,081
• Publication Number:
  US 20040182164A1
• Time in Patent Office: 902 Days
• Field of Search: 73700-756
• US Class Current: 73/745
• CPC Class Codes: G01L 1/205 using distributed sensing elements
• CPC Class Codes: G06F 3/04144 using an array of force sensing means position sensing using the local deformation of sensor cells G06F3/0447
• CPC Class Codes: G06F 3/042 by opto-electronic means

Abstract

A position sensor comprises a substrate having an array of pressure sensors and a membrane overlying the substrate. The membrane includes physical parameters which vary with position. The membrane may include discontinuous regions and protrusions which affect the way in which forces on the membrane are distributed to the substrate. A pressure sensor may also include a controller for receiving pressure information from the substrate, with a signal processor being programmed to localize the depressed region or regions of the substrate.

Claims

1. A position sensor comprising a substrate covered by a membrane and a plurality of pressure sensors on the substrate, the membrane comprising at least first and second areas separated by at least one divider, wherein a force applied to the first area causes substantially no response in those of the pressure sensors underlying the second area

wherein the membrane has a stiffness which varies with position on the membrane.

2. The position sensor according to claim 1, wherein the at least one divider comprises a slot in the membrane.

3. The position sensor according to claim 2, wherein the membrane comprises protrusions, each protrusion positioned to contact a pressure sensor of the plurality of pressure sensors.

4. The position sensor according to claim 1, wherein the at least one divider comprises a region of the membrane attached to the substrate.

5. The position sensor according to claim 4, wherein the membrane comprises protrusions, each protrusion positioned to contact a pressure sensor of the plurality of pressure sensors.

6. The position sensor according to claim 1 wherein the membrane comprises a plurality of first areas wherein the stiffness of the membrane is at least a first stiffness and a second area between two of the plurality of first areas wherein the membrane has a stiffness less than the first stiffness.

7. The position sensor according to claim 1 wherein the membrane comprises a plurality of first areas wherein the stiffness of the membrane does not exceed a first stiffness and a second area between two of the plurality of first areas wherein the membrane has a stiffness of at least the first stiffness.

8. The position sensor according to claim 1, wherein the substrate comprises a plurality of cavities and the at least one divider comprises at least one portion of the membrane attached to the substrate in a region between two of the plurality of cavities.

9. The position sensor according to claim 1, wherein the membrane is separated from the substrate except in at least one region of the membrane wherein the membrane is in contact with the substrate.

10. The position sensor according to claim 1, wherein the membrane comprises protrusions, each protrusion positioned to contact a pressure sensor of the plurality of pressure sensors.

11. The position sensor according to claim 1 wherein the first and second areas are arranged in a non-regular array.

12. The position sensor according to claim 1 wherein the first and second areas are arranged in a regular array.

13. A position sensor comprising a substrate covered by a membrane and a plurality of pressure sensors on the substrate, the membrane comprising at least first and second areas separated by at least one divider, wherein a force applied to the first area causes substantially no response in those of the pressure sensors underlying the second area and the at least one divider comprises a weakened portion of the membrane.

14. The position sensor according to claim 13, wherein the membrane is separated from the substrate except in at least one region of the membrane wherein the membrane is in contact with the substrate.

15. The position sensor according to claim 13, wherein the membrane comprises protrusions, each protrusion positioned to contact a pressure sensor of the plurality of pressure sensors.

16. The position sensor according to claim 13 wherein the first and second areas are arranged in a non-regular array.

17. The position sensor according to claim 13 wherein the first and second areas are arranged in a regular array.

18. The position sensor according to claim 13 wherein the first and second areas comprise one or more of a rectangular, triangular, or truncated triangular area.