Dust removing device and imaging device

Patent metadata

Field	Value
Publication number	US-9252685-B2
Application number	US-201214344396-A
Country	US
Kind code	B2
Filing date	Oct 19, 2012
Priority date	Oct 20, 2011
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

Provided is a dust removing device that can be designed and controlled appropriately and has high dust removal performance even at low temperature, and an imaging device using the dust removing device. In a dust removing device to be set on a base, including a piezoelectric element formed of a piezoelectric material and a pair of opposing electrodes, a vibration member, and a fixation member containing at least a high molecular compound component, a phase transition temperature T from a first ferroelectric crystal phase to a second ferroelectric crystal phase of the piezoelectric material is set to −60° C.≦T≦−5° C., and whereby, the dust removing device can be designed and controlled appropriately and high dust removal performance can be obtained even at low temperature.

First claim

The invention claimed is:

1. A dust removing device comprising:
a piezoelectric element comprising a piezoelectric material and a pair of opposing electrodes;
a vibration member; and
a fixation member containing at least a high molecular compound component,
wherein a phase transition temperature T from a first ferroelectric crystal phase to a second ferroelectric crystal phase of the piezoelectric material is −60° C.≦T≦−5° C., and
wherein a modulus of elasticity at 25° C. of the fixation member is smaller than a modulus elasticity at −5° C. of the fixation member.

2. The dust removing device according to claim 1 , wherein the fixation member comprises an elastomer.

3. The dust removing device according to claim 1 , wherein the fixation member comprises a foamed resin.

4. The dust removing device according to claim 1 , wherein the fixation member is thermoplastic.

5. The dust removing device according to claim 1 , wherein the first ferroelectric crystal phase of the piezoelectric material comprises a tetragonal phase.

6. The dust removing device according to claim 1 , wherein the second ferroelectric crystal phase of the piezoelectric material comprises an orthorhombic phase.

7. The dust removing device according to claim 1 , wherein the piezoelectric material has a lead content of less than 1,000 ppm.

8. The dust removing device according to claim 1 , wherein the piezoelectric material comprises piezoelectric ceramics containing barium titanate as a main component.

9. The dust removing device according to claim 1 , wherein the piezoelectric material comprises, as a main component, a perovskite-type metal oxide represented by general formula (1):
(Ba 1-x Ca x )(Ti 1-y Zr y )O 3 ,
where 0.02≦x≦0.30, 0.020≦y≦0.095, and y≦x.

10. The dust removing device according to claim 9 , wherein the piezoelectric material comprises an Mn component, and a content of the Mn component is from 0.02 parts by weight to 0.40 parts by weight with respect to 100 parts by weight of the perovskite-type metal oxide.

11. The dust removing device according to claim 1 , wherein the piezoelectric element and the vibration member have a plate shape, one electrode surface of the piezoelectric element is fixedly bonded to a plate surface of the vibration member, and the vibration member is fixed to a base through an intermediation of the fixation member.

12. The dust removing device according to claim 1 , comprising multiple piezoelectric elements.

13. The dust removing device according to claim 1 , wherein the vibration member comprises an optical material.

14. An imaging device comprising the dust removing device according to claim 1 and an image pickup element unit, wherein the vibration member of the dust removing device and a light receiving surface of the image pickup element unit are provided coaxially in this order.

Assignees

• Canon Kk

Inventors

• Ifuku Toshihiro
• Shimizu Yasushi
• Furuta Tatsuo
• Matsuda Takanori
• Kubota Makoto
• Hayashi Jumpei

Classifications

• H04N23/811

  by dust removal, e.g. from surfaces of the image sensor or processing of the image signal output by the electronic image sensor · CPC title

• H04N23/52

  Elements optimising image sensor operation, e.g. for electromagnetic interference [EMI] protection or temperature control by heat transfer or cooling elements · CPC title

• B08B7/028 Primary

  Using ultrasounds · CPC title

• G03B2205/00

  Adjustment of optical system relative to image or object surface other than for focusing · CPC title

• H02N2/001 Primary

  Driving devices, e.g. vibrators · CPC title