Method and apparatus for protection of contour sensing devices

• US 20050223818A1
• Filed: 03/25/2005
• Published: 10/13/2005
• Est. Priority Date: 05/16/2000
• Status: Active Grant

• Current Assignee: Lenovo PC International Limited (Lenovo Group Ltd.)
• Original Assignee: Fidelica Microsystems, Inc. (Petters Group Worldwide LLC)
• Inventors: DeConde, Keith T., Pritikin, Joseph J., Diamant, Joram, Ganapathi, Srinivasan K.
• Granted Patent: US 7,316,167 B2
• Time in Patent Office: Days
• US Class Current: 73/862.42
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing
• CPC Class Codes: G06V 40/1329 Protecting the fingerprint sensor against damage caused by the finger
• CPC Class Codes: H01H 1/0036 Switches making use of microelectromechanical systems [MEMS] for electromagnetic relays H01H50/005; for electrostatic relays H01H59/0009
• CPC Class Codes: H01H 67/22 Switches without multi-position wipers

Abstract

A sheet film protective covering for different types of contour sensing devices is described. In a preferred embodiment, this covering is a mylar sheet film that is coated with a layer of a conductive material. The bottom surface of the mylar film is also preferably coated with a layer of an adhesive. The sheet film covering preferably is contiguous and serves the purpose, among other things, to protect the underlying surface of the pressure-sensing device from contaminants and from electrostatic discharge, as well provide force concentration during use.

Claims

1. An apparatus for protecting an array of sensing devices that detect the contour of the object, each of the sensing devices operable to discriminate ridges from valleys of the object when an adjacent ridge and valley is spaced less than 800 microns apart, each of the sensing devices further including a top surface, the apparatus comprising:

a contiguous sheet film protective covering adapted for placement over the top surface of the sensing devices, the sheet film protective covering including a plurality of layers, at least one of the layers enhancing mechanical damage resistance, and at least a top layer being conductive and grounded.

2. The apparatus according to claim 1 wherein the contiguous sheet film protective covering further provides for force concentration to the sensing devices in the array.

3. The apparatus according to claim 1 wherein a bottom layer of the contiguous sheet film protective covering includes an adhesive that bonds with the top surface of substantially all of the sensing devices of the array.

4. The apparatus according to claim 3 wherein a thickness of the adhesive is between 1 micron and 10 microns.5.

5. The apparatus according to claim 1 wherein the top layer is contiguous.

6. The apparatus according to claim 1 wherein the contiguous sheet film protective covering is adapted to cover each of a stylus input sensor, a touchpad, and a fingerprint sensor.

7. The apparatus according to claim 1 wherein one of the layers of the contiguous sheet film protective covering is mylar and the top layer of the contiguous sheet film protective covering is a metallic film.

8. The apparatus according to claim 7 wherein the top layer of the metallic film is contiguous.

9. The apparatus according to claim 7 wherein a thickness of the mylar is between 3 and 50 microns.

10. The apparatus according to claim 7 wherein a resistivity of the top layer is less than about 155 ohms per square.

11. The apparatus according to claim 7 wherein the contiguous sheet film protective covering further includes another polymer layer.

12. The apparatus according to claim 8 wherein a thickness of the another polymer layer is between 3 micron and 50 micron.

13. The apparatus according to claim 11 wherein the another polymer layer is a blocked isocyanate derived polyurethane.

14. The apparatus according to claim 13 wherein the blocked isocyanate derived polyurethane is the top layer, and includes conductive particles disposed therein that render the blocked isocyanate derived polyurethane the metallic film that is conducting and grounded.

15. The apparatus according to claim 14 wherein a resistivity of the top layer is less than about 155 ohms per square.

16. The apparatus according to claim 15 wherein a thickness of the mylar is between 3 micron and 50 micron and the thickness of the another polymer layer is between 3 and 50 microns.

17. The apparatus according to claim 7 wherein a bottom layer of the contiguous sheet film protective covering includes an adhesive that bonds with the top surface of substantially all of the sensing devices of the array.

18. The apparatus according to claim 17 wherein a thickness of the adhesive is between 1 micron and 10 microns.

19. A method comprising the steps of:

providing on a substrate an array of sensing devices for detecting the contour of an object, each of the sensing devices operable to discriminate ridges from valleys of the object when an adjacent ridge and valley is spaced less than 800 microns apart, each of the sensing devices further including a top surface;

applying under at least one of normal room temperature and normal room temperature conditions a contiguous sheet film protective covering adapted for placement over the top surfaces of the sensing devices to form a sensing apparatus, the sheet film protective covering including a plurality of layers, at least one of the layers enhancing mechanical damage resistance, and at least a top layer being conductive and grounded.

20. The method according to claim 19 further including the step of detecting the contour of the object using the array, wherein, during detecting, the contiguous sheet film protective covering provides for force concentration to the sensing devices in the array.

21. The method according to claim 19 wherein the step of applying includes using an adhesive on a bottom layer of the contiguous sheet film protective covering that bonds with the top surface of substantially all of the sensing devices of the array.

22. The method according to claim 21 wherein, during the step of applying, a thickness of the adhesive is between 1 micron and 10 microns.

23. The method according to claim 19 wherein the top layer applied during the step of applying is contiguous.

24. The method according to claim 19 wherein the steps of providing and applying are repeated to form a plurality of the sensing devices, and wherein the step applying forms the contiguous sheet film protective covering over a plurality of different sensing devices, the plurality of different sensing devices including a stylus input sensor, a touchpad, and a fingerprint sensor.

25. The method according to claim 19 wherein during the step of applying one of the layers of the contiguous sheet film protective covering is mylar and the top layer of the contiguous sheet film protective covering is a metallic film.

26. The method according to claim 25 wherein the top layer of the metallic film applied during the step of applying is contiguous.

27. The method according to claim 19 wherein the step of applying further includes providing another polymer layer for the contiguous sheet film protective covering.

28. The method according to claim 27 wherein the another polymer layer applied during the step of applying is a blocked isocyanate derived polyurethane.

29. The method according to claim 28 wherein the blocked isocyanate derived polyurethane is applied as the top layer during the step of applying, and includes conductive particles disposed therein that render the blocked isocyanate derived polyurethane the metallic film that is conducting and grounded.

30. The method according to claim 25 wherein the step of applying includes using an adhesive on a bottom layer of the contiguous sheet film protective covering that bonds with the top surface of substantially all of the sensing devices of the array.

31. The method according to claim 19 wherein the step of applying is performed at normal temperature conditions and normal room pressure conditions.

32. The method according to claim 19 wherein the step of applying is performed at normal temperature conditions.