Piezoelectric transducer and electrophoretic ink display apparatus using piezoelectric transducer

• US 7,173,602 B2
• Filed: 03/19/2004
• Issued: 02/06/2007
• Est. Priority Date: 01/29/1999
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Shimoda, Tatsuya, Hasegawa, Kazumasa
• Primary Examiner(s): Tran; Henry N.
• Application Number:
  US10/805,521
• Publication Number:
  US 20040174097A1
• Time in Patent Office: 1,054 Days
• Field of Search: 345/107, 310/324, 310/328, 310330-332, 310357-359, 310365-366
• US Class Current: 345/107
• CPC Class Codes: B06B 1/0688 with foil-type piezoelectric elements, e.g. PVDF
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/1685 Operation of cells; Circuit arrangements affecting the entire cell
• CPC Class Codes: G09G 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 3/344 based on particles moving in a fluid or in a gas, e.g. electrophoretic devices electrophoretic devices per se G02F1/167
• CPC Class Codes: G09G 3/3493 using light modulating elements actuated by a piezoelectric effect
• CPC Class Codes: H10N 30/40 with electrical input and electrical output, e.g. functioning as transformers
• CPC Class Codes: H10N 39/00 Integrated devices, or assemblies of multiple devices, comprising at least one piezoelectric, electrostrictive or magnetostrictive element covered by groups H10N30/00 – H10N35/00
• CPC Class Codes: Y10T 428/24322 Composite web or sheet
• CPC Class Codes: Y10T 428/24331 including nonapertured component

Abstract

A first electrode layer 12, a first piezoelectric film layer 13, a second electrode layer 14, a second piezoelectric film layer 15, and a third electrode layer 16 are layered in that order on a substrate 11; these are constrained so as pot to expand or contract in a thickness direction and a piezoelectric transducer is constructed thereby. A plurality of gate lines 201 and 202, a plurality of data lines 203 and 204 intersecting with the gate lines, and thin film transistors 205 and 207, disposed at the intersections of the abovementioned gate lines and data lines, are established; one source-drain of the abovementioned thin film transistors is connected to the abovementioned data lines; another source-drain of the abovementioned thin film transistors is connected to the input sides of the abovementioned thin film piezoelectric transducers 208 through 210; the output sides of the abovementioned thin film piezoelectric transducers are connected to the electrodes of electrophoretic ink display elements; and an electrophoretic ink display apparatus is constructed thereby.

Claims

1. A thin film piezoelectric transducer comprising:

a supporting base having a cavity formed therein;

a diaphragm disposed on said supporting base;

a piezoelectric film layer located above said cavity, said piezoelectric film layer having;

an upper surface which is not adjacent to said diaphragm; and

an end surface adjacent to said upper surface;

a first electrode layer and a second electrode layer disposed on said diaphragm;

a third electrode layer disposed on said piezoelectric film layer;

wherein said second electrode layer and said third electrode layer are spaced apart along said upper surface of said piezoelectric film layer;

said first electrode layer, said second electrode layer, and said third electrode layer independently contact said piezoelectric film layer; and

only a part of said first electrode layer of said three electrode layers is disposed between said diaphragm and said piezoelectric film layer.

2. The thin film piezoelectric transducer, according to claim 1, wherein said supporting base wherein said cavity is formed is a single crystal silicon substrate.

3. The thin film piezoelectric transducer, according to claim 1, wherein said diaphragm is formed of a zirconia thin film.

4. The thin film piezoelectric transducer, according to claim 1, wherein said first, second, and third electrode layers are formed of a multilayered structure of platinum and titanium.

5. The thin film piezoelectric transducer, according to claim 1, wherein said piezoelectric film layer is formed of a lead-titanate-zirconate piezoelectric material.

6. The thin film piezoelectric transducer, according to claim 1, wherein an arbitrary voltage waveform is applied between said first electrode layer and said second electrode layer, and said arbitrary voltage waveform which has been amplified is output to between said first electrode layer and said third electrode layer.

7. A thin film piezoelectric transducer comprising:

a supporting base having a cavity formed therein;

a diaphragm disposed on said supporting base;

a piezoelectric film layer located above said cavity;

a first electrode layer and a second electrode layer disposed on said diaphragm;

a third electrode layer disposed on said piezoelectric film layer;

wherein said second electrode layer and third electrode layer are disposed as a pair with a space therebetween on said piezoelectric film layer located above said cavity;

said first electrode layer, said second electrode layer, and said third electrode layer contact said piezoelectric film layer;

only a part of said first electrode layer of said three electrode layers is disposed between said diaphragm and said piezoelectric film layer; and

said second and third electrode layers being positioned on a side of said piezoelectric film layer.

8. The thin film piezoelectric transducer, according to claim 7, wherein said third electrode layer is formed to span an end surface and upper layer surface of said piezoelectric film layer.

9. The thin film piezoelectric transducer, according to claim 7, wherein said supporting base wherein said cavity is formed is a single crystal silicon substrate.

10. The thin film piezoelectric transducer, according to claim 7, wherein said diaphragm is formed of a zirconia thin film.

11. The thin film piezoelectric transducer, according to claim 7, wherein said first, second, and third electrode layers are formed of a multilayered structure of platinum and titanium.

12. The thin film piezoelectric transducer, according to claim 7, wherein said piezoelectric film layer is formed of a lead-titanate-zirconate piezoelectric material.

13. The thin film piezoelectric transducer, according to claim 7, wherein an arbitrary voltage waveform is applied between said first electrode layer and said second electrode layer, and said arbitrary voltage waveform which has been amplified is output to between said first electrode layer and said third electrode layer.

14. A thin film piezoelectric transducer comprising:

a supporting base having a cavity formed therein;

a diaphragm disposed on said supporting base;

a piezoelectric film layer located above said cavity;

a first electrode layer and a second electrode layer disposed on said diaphragm;

a third electrode layer disposed on said piezoelectric film layer;

wherein said second electrode layer and third electrode layer are disposed as a pair with a space therebetween on said piezoelectric film layer located above said cavity;

wherein said first electrode layer, said second electrode layer, and said third electrode layer contact said piezoelectric film layer;

only a part of said first electrode layer of said three electrode layers is disposed between said diaphragm and said piezoelectric film layer; and

upon receiving a voltage, a characteristic of said piezoelectric film layer that amplifies an applied voltage amplifies said voltage.

15. The thin film piezoelectric transducer, according to claim 14, wherein said third electrode layer is formed to span an end surface and upper layer surface of said piezoelectric film layer.

16. The thin film piezoelectric transducer, according to claim 14, wherein said supporting base wherein said cavity is formed is a single crystal silicon substrate.

17. The thin film piezoelectric transducer, according to claim 14, wherein said diaphragm is formed of a zirconia thin film.

18. The thin film piezoelectric transducer, according to claim 14, wherein said first, second, and third electrode layers are formed of a multilayered structure of platinum and titanium.

19. The thin film piezoelectric transducer, according to claim 14, wherein said piezoelectric film layer is formed of a lead-titanate-zirconate piezoelectric material.

20. The thin film piezoelectric transducer, according to claim 14, wherein an arbitrary voltage waveform is applied between said first electrode layer and said second electrode layer, and said arbitrary voltage waveform which has been amplified is output to between said first electrode layer and said third electrode layer.

21. The thin film transducer according to claim 14, wherein said voltage that is inputted or outputted is an alternating voltage.

22. A thin film piezoelectric transducer comprising:

a supporting base having a cavity formed therein;

a diaphragm disposed on said supporting base;

a piezoelectric film layer located above said cavity;

a first electrode layer and a second electrode layer disposed on said diaphragm;

a third electrode layer disposed on said piezoelectric film layer;

wherein said second electrode layer and third electrode layer are disposed as a pair with a space therebetween on said piezoelectric film layer located above said cavity;

said first electrode layer, said second electrode layer, and said third electrode layer contact said piezoelectric film layer;

only a part of said first electrode layer of said three electrode layers is disposed between said diaphragm and said piezoelectric film layer; and

said second and third electrode layers being positioned on one side of said piezoelectric film layer in a width direction of said cavity.

23. The thin film piezoelectric transducer, according to claim 22, wherein said third electrode layer is formed to span an end surface and upper layer surface of said piezoelectric film layer.

24. The thin film piezoelectric transducer, according to claim 22, wherein said supporting base wherein said cavity is formed is a single crystal silicon substrate.

25. The thin film piezoelectric transducer, according to claim 22, wherein said diaphragm is formed of a zirconia thin film.

26. The thin film piezoelectric transducer, according to claim 22, wherein said first, second, and third electrode layers are formed of a multilayered structure of platinum and titanium.

27. The thin film piezoelectric transducer, according to claim 22, wherein said piezoelectric film layer is formed of a lead-titanate-zirconate piezoelectric material.

28. The thin film piezoelectric transducer, according to claim 22, wherein an arbitrary voltage waveform is applied between said first electrode layer and said second electrode layer, and said arbitrary voltage waveform which has been amplified is output to between said first electrode layer and said third electrode layer.