Surface sensor

Patent metadata

Field	Value
Publication number	US-9818014-B2
Application number	US-201414904527-A
Country	US
Kind code	B2
Filing date	Jun 23, 2014
Priority date	Jul 12, 2013
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

A sensor unit for measuring surface structures and properties of an object of organic tissue includes a contact surface adapted to have mechanical contact with the object, a first dielectric layer made from a dielectric material, a first conductor layer including at least one shielding electrode essentially covering an area of the dielectric layer facing the contact surface, the at least one shielding electrode surrounding at least one essentially non-conductive aperture defining a sensing region, and a second conductor layer separated from the first conductor layer by the first dielectric layer and comprising a number of conductive wires extending at least partially under the at least one aperture and having a direction essentially perpendicular to the sensing region, each wire having a predetermined width. A sensing area of each wire is defined by the width and the length of each wire extending in the sensing region.

First claim

The invention claimed is:

1. Sensor unit for measuring structures and properties of an object of organic tissue, the sensor unit comprising:
a contact surface adapted to have mechanical contact with said object,
a first dielectric layer made from a dielectric material,
a first conductor layer including at least one shielding electrode essentially covering an area of said first dielectric layer facing said contact surface, the at least one shielding electrode surrounding at least one essentially non-conductive aperture defining a sensing region, and
a second conductor layer separated from said first conductor layer by said first dielectric layer and comprising a number of conductive wires extending at least partially under said at least one aperture and having a direction essentially perpendicular to said sensing region, each wire having a predetermined width,
wherein a sensing area related to each wire is defined by the width and the length of a part of the wire extending into the sensing region.

2. Sensor unit according to claim 1 , wherein each wire is coupled to a processing unit, said processing unit also being coupled to at least one drive electrode positioned so as to be galvanically or capacitively coupled to said contact surface and to apply a varying voltage between the at least one drive electrode and said wires in said sensing region.

3. Sensor unit according to claim 2 , wherein said at least one drive electrode is constituted by a part of said first conductor layer, being electrically insulated from said at least one shielding electrode and being electrically coupled to said contact surface.

4. Sensor unit according to claim 2 , wherein said processing unit is electrically coupled to an interface means for communicating with external equipment.

5. Sensor unit according to claim 1 , wherein the at least one aperture defines an essentially linear sensing region.

6. Sensor unit according to claim 5 , comprising wires extending less than half an aperture width into the aperture, the unit comprising wires extending from both sides of the aperture in direction across the aperture width, thus defining two linear sensing units in said aperture.

7. Sensor unit according to claim 1 , wherein the wires extend across the width of said sensing region.

8. Sensor unit according to claim 1 , comprising at least two apertures, each aperture representing a sensing region and each comprising wires defining sensing areas in said sensing region.

9. Sensor unit according to claim 8 including a processing unit, wherein said processing unit is adapted to measure characteristics in individual sensing areas in a time sequence and calculating movement of a surface moved over the sensor unit.

10. Sensor unit according to claim 1 , wherein said wires extend a chosen length into said aperture, the chosen length and wire width thus defining the sensing area.

11. Sensor unit according to claim 1 , wherein the first dielectric layer under said at least one aperture at least partially contains a dielectric material having a reduced thickness.

12. Sensor unit according to claim 1 , wherein the first dielectric layer is completely removed under said at least one aperture.

13. Sensor unit according to claim 1 , wherein said first dielectric layer is made from a flexible material.

14. Sensor unit according to claim 13 , wherein said first dielectric layer is made from polyimide.

15. Sensor unit according to claim 1 , wherein said first dielectric layer is made from a rigid material such as FR_4.

16. Sensor unit according to claim 1 , wherein said contact surface comprises an insulating layer covering said first conductor layer.

17. Sensor unit according to claim 1 , comprising a second dielectric layer separated from the first dielectric layer by said second conductor layer.

Assignees

• Idex Asa

Inventors

• Bredholt Geir Ivar
• Bernstein Ralph W
• Sløgedal Øyvind

Classifications

• G06K9/0002 Primary

  Physics · mapped topic

• G06K9/00053

  Physics · mapped topic

• G06V40/1329 Primary

  Protecting the fingerprint sensor against damage caused by the finger · CPC title

• G06V40/1306 Primary

  non-optical, e.g. ultrasonic or capacitive sensing · CPC title