Vibration actuator

Patent metadata

Field	Value
Publication number	US-10406559-B2
Application number	US-201816132741-A
Country	US
Kind code	B2
Filing date	Sep 17, 2018
Priority date	Sep 28, 2017
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

A vibration actuator having a stationary element; a movable element that is supported elastically so as to enable vibration on the stationary element; and a driving source for causing reciprocating vibration of the movable element in relation to the stationary element, wherein: the movable element comprises an opposed face that opposes an opposing face of the stationary element; a magnetic fluid that has viscosity is filled into a gap between the opposing face and the opposed face and is attracted magnetically to at least either the opposing face or the opposed face; and on the other of the opposing face or the opposed face, a holding region for retaining the magnetic fluid is provided, and a lipophobic surface, for repelling the magnetic fluid is provided so as to surround the holding region.

First claim

The invention claimed is:

1. A vibration actuator comprising:
a stationary element;
a movable element that is supported elastically so as to enable vibration on the stationary element; and
a driver causing reciprocating vibration of the movable element in relation to the stationary element, wherein:
the movable element comprises an opposed face that opposes an opposing face of the stationary element;
a magnetic fluid that has viscosity is filled into a gap between the opposing face and the opposed face and is attracted magnetically to at least either the opposing face or the opposed face; and
on the other of the opposing face or the opposed face, a holding region for retaining the magnetic fluid is provided, and a lipophobic surface, for repelling the magnetic fluid is provided so as to surround the outside of the holding region.

2. The vibration actuator as set forth in claim 1 , wherein:
the driver comprises a flat plate-shaped coil provided in the stationary element and a magnet provided in the movable element, facing the coil; and
the opposing face is provided on the surface of the coil, and a region that is over a wound core portion of the coil, or that includes over the wound core portion, is used as the holding region.

3. The vibration actuator as set forth in claim 1 , wherein:
a lipophilic surface is provided at the holding region of the opposing face.

4. The vibration actuator as set forth in claim 3 , wherein:
the lipophilic surface is an organic solvent coated surface.

5. The vibration actuator as set forth in claim 1 , wherein:
the lipophobic surface is a fluorine resin coated surface.

6. An electronic device comprising a vibration actuator as set forth in claim 1 .

Assignees

• Nidec Copal Corp

Inventors

• OKAYASU Shinsuke

Classifications

• H04R9/066

  using the principle of inertia · CPC title

• H04R9/047

  in which the windings of the moving coil lay in the same plane · CPC title

• H04R9/043

  Inner suspension or damper, e.g. spider (outer suspension or surround H04R7/16) · CPC title

• H04R9/027

  Air gaps using a magnetic fluid · CPC title

• H04R2499/11

  Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's · CPC title