Pressure sensing element comprising electrode including protrusion having elasticity

• US 9,752,940 B2
• Filed: 12/08/2015
• Issued: 09/05/2017
• Est. Priority Date: 12/22/2014
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: Ogura, Tetsuyoshi, Noine, Keiji, Ezaki, Kenichi, Masuda, Shinobu
• Primary Examiner(s): Caputo, Lisa
• Assistant Examiner(s): Hollington, Octavia
• Application Number:
  US14/962,958
• Publication Number:
  US 20160178460A1
• Time in Patent Office: 637 Days
• Field of Search: 73862626
• CPC Class Codes: G01L 1/142 using capacitors
• CPC Class Codes: G01L 9/0072 using variations in capacitance

Abstract

A pressure sensing element of an aspect of the present disclosure includes a first electrode including at least one protrusion having elasticity; a second electrode facing the at least one protrusion; and a dielectric disposed between the first electrode and the second electrode and including a first dielectric and a second dielectric. The first dielectric is disposed between a top of the at least one protrusion and the second electrode, and is in contact with each of the top of the at least one protrusion and the second electrode. The second dielectric is disposed between a first portion of the first electrode, the first portion not including the at least one protrusion, and the first dielectric.

Claims

1. A pressure sensing element comprising:

a first electrode including at least one protrusion having elasticity;

a second electrode facing the at least one protrusion;

a dielectric disposed between the first electrode and the second electrode and including a first dielectric and a second dielectric, and

a spacer disposed between the first electrode and the second electrode;

wherein the first dielectric is disposed between a top of the at least one protrusion and the second electrode, and is in contact with each of the top of the at least one protrusion and the second electrode without application of a load,

the second dielectric is disposed between a first portion of the first electrode, the first portion not including the at least one protrusion, and the first dielectric, and

the spacer is disposed only on a peripheral portion of each of the first electrode and the second electrode, and the spacer directly contacts the first portion of the first electrode.

2. The pressure sensing element according to claim 1, wherein the pressure sensing element has a capacitance including a first capacitance and a second capacitance,

the first capacitance is a capacitance of a first capacitor including a contact area between the at least one protrusion and the first dielectric, and

the second capacitance is a capacitance of a second capacitor including a contact area between the first dielectric and the second dielectric.

3. The pressure sensing element according to claim 2, wherein a capacitance characteristic of the pressure sensing element has higher linearity than a capacitance characteristic of the first capacitance and a capacitance characteristic of the second capacitance.

4. The pressure sensing element according to claim 2, wherein the first capacitor includes the at least one protrusion, a first section of the second electrode facing the at least one protrusion, and a first section of the first dielectric positioned between the at least one protrusion and the first section of the second electrode, and

the second capacitor includes the first portion of the first electrode, a second section of the second electrode facing the first portion of the first electrode, a second section of the first dielectric positioned between the first portion of the first electrode and the second section of the second electrode, and the second dielectric.

5. The pressure sensing element according to claim 1, wherein the at least one protrusion has a tapered shape in which a width of the tapered shape gradually decreases toward the second electrode.

6. The pressure sensing element according to claim 1, wherein the at least one protrusion and the second dielectric are configured such that the second dielectric deforms when the at least one protrusion deforms.

7. The pressure sensing element according to claim 1, wherein

the second electrode has a first main surface facing the first electrode and a second main surface opposite the first main surface, and

the at least one protrusion is configured such that a contact area between the at least one protrusion and the first dielectric increases due to deformation of the at least one protrusion caused by an application of a load to the second main surface.

8. The pressure sensing element according to claim 1, wherein

the second electrode has a first main surface facing the first electrode and a second main surface opposite the first main surface, and

the at least one protrusion is configured such that a thickness of the second dielectric decreases due to deformation of the second dielectric caused by an application of a load to the second main surface.

9. The pressure sensing element according to claim 1, wherein the first dielectric has elasticity.

10. The pressure sensing element according to claim 1, wherein

the second electrode has a first main surface facing the first electrode and a second main surface opposite the first main surface, and

the at least one protrusion and the first dielectric are configured such that the at least one protrusion and the first dielectric are both deformed when a load is applied to the second main surface.

11. The pressure sensing element according to claim 1, wherein the first dielectric has a higher elastic modulus than the at least one protrusion.

12. The pressure sensing element according to claim 1, wherein at least one selected from the group consisting of the first electrode, the second electrode, the first dielectric, and the second dielectric has light transmissivity.

13. The pressure sensing element according to claim 1, further comprising a supporting member and a pressing member, wherein

the second electrode has a first main surface facing the first electrode and a second main surface opposite the first main surface,

the first electrode has a third main surface facing the second electrode and a fourth main surface opposite the third main surface,

the supporting member is in contact with the fourth main surface, and

the pressing member is in contact with the second main surface.

14. The pressure sensing element according to claim 1, wherein the spacer includes an insulating resin.

15. The pressure sensing element according to claim 1, wherein the spacer is disposed between the first portion of the first electrode and the first dielectric.