Strain sensing element, pressure sensor, microphone, blood pressure sensor, and touch panel

Patent metadata

Field	Value
Publication number	US-9342179-B2
Application number	US-201414471226-A
Country	US
Kind code	B2
Filing date	Aug 28, 2014
Priority date	Sep 20, 2013
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

According to one embodiment, a strain sensing element includes a film unit, and a sensing unit. The film unit has a film surface and is capable of being deformed. The sensing unit includes a first sensing element and a second sensing element. The first sensing element is provided between a part of the film unit and the second sensing element. The first sensing element includes a first magnetic layer having a changeable magnetization with a deformation of the film unit, a second magnetic layer provided apart from the first magnetic layer, and a first spacer layer provided between the first and second magnetic layers. The second sensing element includes a third magnetic layer having a changeable magnetization with the deformation of the film unit, a fourth magnetic layer provided apart from the third magnetic layer, and a second spacer layer provided between the third and fourth magnetic layers.

First claim

What is claimed is:

1. A strain sensing element comprising:
a film unit having a film surface and being deformable; and
a sensing unit including a first sensing element and a second sensing element,
the first sensing element being provided between a part of the film unit and the second sensing element,
the first sensing element including a first magnetic layer, a second magnetic layer provided apart from the first magnetic layer in a first direction crossing the film surface, and a first spacer layer provided between the first magnetic layer and the second magnetic layer, a magnetization of the first magnetic layer being configured to change in accordance with a deformation of the film unit,
the second sensing element including a third magnetic layer, a fourth magnetic layer provided apart from the third magnetic layer in the first direction, and a second spacer layer provided between the third magnetic layer and the fourth magnetic layer, a magnetization of the third magnetic layer being configured to change in accordance with the deformation of the film unit,
wherein
a magnetization of the second magnetic layer and a magnetization of the fourth magnetic layer are fixed,
the fourth magnetic layer is disposed between the third magnetic layer and the film unit, and
the second magnetic layer is disposed between the first magnetic layer and the film unit.

2. The element according to claim 1 , further comprising:
a first electrode; and
a second electrode,
the sensing unit being provided between the first electrode and the second electrode,
a current flowing between the first electrode and the second electrode being configured to flow between the first magnetic layer and the second magnetic layer, and
the current being configured to flow between the third magnetic layer and the fourth magnetic layer.

3. A pressure sensor comprising:
the strain sensing element according to claim 1 ; and
a support supporting the film unit.

4. A strain sensing element comprising:
a film unit having a film surface and being deformable; and
a sensing unit including a first sensing element and a second sensing element,
the first sensing element being provided between a part of the film unit and the second sensing element,
the first sensing element including a first magnetic layer, a second magnetic layer provided apart from the first magnetic layer in a first direction crossing the film surface, and a first spacer layer provided between the first magnetic layer and the second magnetic layer, a magnetization of the first magnetic layer being configured to change in accordance with a deformation of the film unit,
the second sensing element including a third magnetic layer, a fourth magnetic layer provided apart from the third magnetic layer in the first direction, and a second spacer layer provided between the third magnetic layer and the fourth magnetic layer, a magnetization of the third magnetic layer being configured to change in accordance with the deformation of the film unit,
wherein
a magnetization of the second magnetic layer and a magnetization of the fourth magnetic layer are fixed,
the third magnetic layer is disposed between the fourth magnetic layer and the film unit, and
the first magnetic layer is disposed between the second magnetic layer and the film unit.

5. A microphone comprising the pressure sensor according to claim 3 .

6. A strain sensing element comprising:
a film unit having a film surface and being deformable; and
a sensing unit including a first sensing element and a second sensing element,
the first sensing element being provided between a part of the film unit and the second sensing element,
the first sensing element including a first magnetic layer, a second magnetic layer provided apart from the first magnetic layer in a first direction crossing the film surface, and a first spacer layer provided between the first magnetic layer and the second magnetic layer, a magnetization of the first magnetic layer being configured to change in accordance with a deformation of the film unit,
the second sensing element including a third magnetic layer, a fourth magnetic layer provided apart from the third magnetic layer in the first direction, and a second spacer layer provided between the third magnetic layer and the fourth magnetic layer, a magnetization of the third magnetic layer being configured to change in accordance with the deformation of the film unit,
wherein
a magnetization of the second magnetic layer and a magnetization of the fourth magnetic layer are fixed,
the fourth magnetic layer is disposed between the third magnetic layer and the film unit, and
the first magnetic layer is disposed between the second magnetic layer and the film unit.

7. The element according to claim 1 , wherein
the third magnetic layer is disposed between the fourth magnetic layer and the film unit, and
the second magnetic layer is disposed between the first magnetic layer and the film unit.

8. The element according to claim 1 , wherein a distance between the first magnetic layer and the third magnetic layer is not more than ⅕ of a thickness along the first direction of the film unit.

9. The element according to claim 1 , wherein the sensing unit further includes a first hard bias layer arranged with the first sensing element in a second direction crossing the first direction.

10. The element according to claim 1 , wherein the sensing unit further includes a first shield layer arranged with the first sensing element in a second direction crossing the first direction.

11. The element according to claim 1 , wherein the sensing unit further includes a second shield layer provided between the first sensing element and the second sensing element.

12. The element according to claim 1 , wherein the sensing unit further includes an interposition layer provided between the first sensing element and the second sensing element.

13. The element according to claim 1 , wherein
the sensing unit is provided in a plurality,
the plurality of sensing units are provided on the film unit, and
the sensing units are apart from each other in a direction crossing the first direction.

14. The element according to claim 13 , wherein the sensing units are electrically connected in series.

15. The element according to claim 13 , wherein the sensing units are electrically connected in parallel.

16. The element according to claim 13 , wherein
the sensing units are electrically connected to one another and
a number of the sensing units electrically connected is not less than 7 and not more than 200.

17. A blood pressure sensor comprising the pressure sensor according to claim 3 .

18. A touch panel comprising the pressure sensor according to claim 3 .

Assignees

• Toshiba Kk

Inventors

• Fuji Yoshihiko
• Fukuzawa Hideaki
• Nagata Tomohiko
• Hori Akio
• Higashi Yoshihiro

Classifications

• A61B5/02141 Primary

  Details of apparatus construction, e.g. pump units or housings therefor, cuff pressurising systems, arrangements of fluid conduits or circuits (A61B5/02233, A61B5/0235 take precedence) · CPC title

• H04R19/005

  using semiconductor materials · CPC title

• G06F3/0414 Primary

  using force sensing means to determine a position · CPC title

• G01L9/16

  by making use of variations in the magnetic properties of material resulting from the application of stress · CPC title

• A61B5/6824

  Arm or wrist · CPC title