Method of manufacturing piezoelectric ceramics, piezoelectric ceramics, piezoelectric element, ultrasonic motor, optical apparatus, dust removing device, image pickup apparatus, ultrasonic probe, ultrasonic diagnostic apparatus, and electronic apparatus

Patent metadata

Field	Value
Publication number	US-2021328131-A1
Application number	US-202117222120-A
Country	US
Kind code	A1
Filing date	Apr 5, 2021
Priority date	Apr 20, 2020
Publication date	Oct 21, 2021
Grant date	—

Abstract

Provided are a piezoelectric ceramics which does not contain lead, has small temperature dependence of a piezoelectric constant within an operating temperature range, and has high density, a high mechanical quality factor, a satisfactory piezoelectric constant, and a small surface roughness, and a method of manufacturing the piezoelectric ceramics. The method of manufacturing a piezoelectric ceramics is characterized by including: sintering a compact containing a raw material at 1,000° C. or more to obtain a sintered compact; abrading the sintered compact; and annealing the abraded sintered compact at a temperature of 800° C. or more and less than 1,000° C.

First claim

What is claimed is:

1 . A method of manufacturing a piezoelectric ceramics comprising:
sintering a compact containing a raw material at 1,000° C. or more to obtain a sintered compact; abrading the sintered compact; and annealing the abraded sintered compact at a temperature of 800° C. or more and less than 1,000° C.

2 . The method of manufacturing a piezoelectric ceramics according to claim 1 , wherein the annealing is performed by keeping the temperature for 6 minutes or more and less than 10 hours.

3 . A method of manufacturing a piezoelectric element comprising:
obtaining a piezoelectric ceramics by the method of manufacturing a piezoelectric ceramics of claim 1 ; and arranging an electrode on the piezoelectric ceramics, wherein the arranging an electrode on the piezoelectric ceramics is performed before the annealing, and wherein the electrode is baked by the annealing.

4 . The method of manufacturing a piezoelectric ceramics according to claim 1 , wherein the piezoelectric ceramics contains titanium and barium as main components.

5 . The method of manufacturing a piezoelectric element according to claim 3 , wherein the piezoelectric ceramics contains titanium and barium as main components.

6 . A piezoelectric ceramics comprising titanium and barium as main components,
wherein the piezoelectric ceramics has an electromechanical coupling coefficient k 31 at room temperature of 0.252 or more, and wherein the piezoelectric ceramics has a roughness Ra of 0.19 μm or less on at least a part of a surface thereof.

7 . The piezoelectric ceramics according to claim 6 ,
wherein the piezoelectric ceramics contains an oxide containing Ba, Ca, Ti, and Zr, and Mn, wherein a molar ratio “x” of the Ca with respect to a sum of the Ba and the Ca is 0.02≤x≤0.30, wherein a molar ratio “y” of the Zr with respect to a sum of the Ti and the Zr is 0.020≤y≤0.095, wherein the molar ratio “y” and the molar ratio “x” has a relationship of y≤x, wherein a molar ratio “a” of the sum of the Ba and the Ca with respect to the sum of the Ti and the Zr is 1.00≤a≤1.01, and wherein a content of the Mn with respect to 100 parts by weight of the oxide is 0.02 part by weight or more and 0.40 part by weight or less in terms of a metal.

8 . The piezoelectric ceramics according to claim 6 , wherein a fluctuation rate of the electromechanical coupling coefficient k 31 is 35% or less within a temperature range of 0° C. or more and 60° C. or less.

9 . The piezoelectric ceramics according to claim 6 , wherein the piezoelectric ceramics has a mechanical quality factor Qm of 1,000 or more.

10 . The piezoelectric ceramics according to claim 6 , wherein the piezoelectric ceramics is formed of crystal grains having an average equivalent circle diameter of 1 μm or more and 10 μm or less.

11 . The piezoelectric ceramics according to claim 6 , wherein the piezoelectric ceramics has a relative density of 93% or more and 100% or less.

12 . A piezoelectric element comprising:
an electrode; and a piezoelectric ceramics, wherein the piezoelectric ceramics is the piezoelectric ceramics of claim 6 .

13 . An ultrasonic motor comprising:
a vibrating body in which the piezoelectric element of claim 12 is arranged; and a contact body configured to be brought into contact with the vibrating body to move relative to the vibrating body.

14 . An optical apparatus comprising:
a drive unit; and the ultrasonic motor of claim 13 provided to the drive unit.

15 . A vibration device comprising a vibrating body in which the piezoelectric element of claim 12 is arranged on a vibrating plate.

16 . A dust removing device comprising:
a vibrating portion; and the vibration device of claim 15 provided to the vibrating portion.

17 . An image pickup apparatus comprising:
the dust removing device of claim 16 ; and an image pickup element unit, wherein a vibrating plate of the dust removing device is arranged on a light receiving surface side of the image pickup element unit.

18 . An ultrasonic probe comprising:
a housing; and the piezoelectric element of claim 12 configured to transmit and receive a signal.

19 . An ultrasonic diagnostic apparatus comprising:
the ultrasonic probe of claim 18 ; an image processing unit configured to process an obtained signal; and an image display portion configured to display image data processed by the image processing unit.

20 . The ultrasonic diagnostic apparatus according to claim 19 further comprising a cable configured to connect the ultrasonic probe and the image processing unit in a communicable manner.

21 . A piezoelectric acoustic component comprising the piezoelectric element of claim 12 .

22 . An electronic apparatus comprising:
a member; and the piezoelectric element of claim 12 arranged on the member.

Assignees

• Canon Kk

Inventors

• Furuta Tatsuo
• Matsuda Takanori
• Yabuta Hisato
• Uebayashi Akira

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

• H04N23/55

  Optical parts specially adapted for electronic image sensors; Mounting thereof · CPC title

• B08B7/028 Primary

  Using ultrasounds · CPC title

• H04N23/54

  Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils · CPC title

• H04N23/50

  Constructional details · CPC title