ELECTROMECHANICAL TRANSDUCER, LIQUID DROPLET DISCHARGE HEAD, AND IMAGE FORMING APPARATUS

• US 20160001556A1
• Filed: 06/24/2015
• Published: 01/07/2016
• Est. Priority Date: 07/02/2014
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Masuda, Toshiaki, Miwa, Keishi
• Granted Patent: US 9,321,263 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B41J 2/14201 Structure of print heads with piezoelectric elements
• CPC Class Codes: B41J 2/14233 of film type, deformed by bending and disposed on a diaphragm
• CPC Class Codes: B41J 2/161 of film type, deformed by bending and disposed on a diaphragm
• CPC Class Codes: B41J 2/1628 dry etching
• CPC Class Codes: B41J 2/1631 photolithography
• CPC Class Codes: B41J 2/1642 thin film formation by CVD [chemical vapor deposition]
• CPC Class Codes: B41J 2/1645 thin film formation by spincoating
• CPC Class Codes: H10N 30/06 Forming electrodes or interconnections, e.g. leads or terminals
• CPC Class Codes: H10N 30/082 by etching, e.g. lithography
• CPC Class Codes: H10N 30/2047 Membrane type
• CPC Class Codes: H10N 30/87 Electrodes or interconnections, e.g. leads or terminals

Abstract

An electromechanical transducer includes a substrate; a diaphragm formed on the substrate; and a piezoelectric element that includes a lower electrode; a piezoelectric member; and an upper electrode, in which a lower electrode film to form the lower electrode, a piezoelectric film to form the piezoelectric member, and an upper electrode film to form the upper electrode are laminated in layers on the diaphragm formed on the substrate. The piezoelectric element is formed such that the lower electrode film, the piezoelectric member film, and the upper electrode film are patterned to form the lower electrode, the piezoelectric member, and the upper electrode, each of which has a desired pattern; and corners of the lower electrode are rounded.

Claims

1. An electromechanical transducer comprising:

a substrate;

a diaphragm formed on the substrate; and

a piezoelectric element including;

a lower electrode;

a piezoelectric member; and

an upper electrode, wherein

a lower electrode film to form the lower electrode, a piezoelectric film to form the piezoelectric member, and an upper electrode film to form the upper electrode are laminated in layers on the diaphragm formed on the substrate;

the piezoelectric element is formed such that the lower electrode film, the piezoelectric member film, and the upper electrode film are patterned to form the lower electrode, the piezoelectric member, and the upper electrode, each of which has a desired pattern; and

corners of the lower electrode are rounded.

2. The electromechanical transducer as claimed in claim 1, wherein a curvature radius of the rounded corners is not less than 5 [μ

m].

3. The electromechanical transducer as claimed in claim 1, wherein a peripheral portion of the lower electrode is tapered at an angle relative to the diaphragm.

4. The electromechanical transducer as claimed in claim 3, wherein the peripheral portion of the lower electrode is tapered at an angle relative to the diaphragm of not more than 60 degrees.

5. The electromechanical transducer as claimed in claim 1, further comprising an adherence layer between the lower electrode and the diaphragm.

6. The electromechanical transducer as claimed in claim 5, wherein the adherence layer comprises titanium or Ti.

7. A liquid droplet discharge head comprising:

a plurality of nozzles to discharge liquid droplets;

liquid chambers each to contain a liquid, and communicating to the plurality of nozzles; and

the electromechanical transducer as claimed in claim 1,

wherein the piezoelectric element is disposed on the substrate to form the liquid chambers to squeeze the liquid inside the liquid chambers.

8. An image forming apparatus comprising:

the liquid droplet discharge head as claimed in claim 7 to discharge liquid droplets to form an image.