Abstract: An actuator includes a substrate, a vibration film, and a piezoelectric element. The substrate has a void space having a first width, defined by opposed inner walls, in a width direction. The vibration film is disposed over the substrate in a lamination direction perpendicular to the width direction. The vibration film serves as a part of a wall of the void space. The piezoelectric element is disposed over the vibration film in the lamination direction. The piezoelectric element is opposed to the void space of the substrate via the vibration film. The piezoelectric element has a second width smaller than the first width in the width direction. The piezoelectric element has outer ends, defining the second width, within the opposed inner walls of the void space in the width direction.

Abstract: A liquid discharge head includes: a nozzle plate having a nozzle from which a liquid is to be discharged in a discharge direction, the nozzle having a cylindrical hole having periodical convex portions and concave portions on a sidewall of the nozzle in the discharge direction, a diameter of an outermost portion of the nozzle in the discharge direction being smaller than an average diameter of minimum values and maximum values of diameters of the cylindrical shape. The average diameter is obtained by: Average diameter = (Sum of minimum values + Sum of maximum values) / (Count of minimum values + Count of maximum values).

Abstract: A liquid discharge head includes a plurality of nozzles to discharge a liquid, a plurality of pressure chambers communicating with the plurality of nozzles, respectively, a plurality of individual supply channels communicating with the plurality of pressure chambers, respectively, a plurality of common-supply branch channels each having a side face and a bottom face and communicating with two or more of the plurality of individual supply channels, respectively, and a common-supply main channel communicating with the plurality of common-supply branch channels. The plurality of common-supply branch channels includes a curved portion on a corner between the side face and the bottom face of each of the plurality of common-supply branch channels along a direction of liquid flow in the plurality of common-supply branch channels.

Abstract: A liquid discharge head includes a plurality of nozzles to discharge a liquid, a plurality of pressure chambers communicating with the plurality of nozzles, respectively, a plurality of individual supply channels communicating with the plurality of pressure chambers, respectively, a plurality of common-supply branch channels each having a side face and a bottom face and communicating with two or more of the plurality of individual supply channels, respectively, and a common-supply main channel communicating with the plurality of common-supply branch channels. The plurality of common-supply branch channels includes a curved portion on a corner between the side face and the bottom face of each of the plurality of common-supply branch channels along a direction of liquid flow in the plurality of common-supply branch channels.

Abstract: An electromechanical transducer includes a first electrode mounted on one of a substrate and a base film, an electromechanical transducer film mounted on the first electrode and made of a piezoelectric substance having a perovskite crystal structure, and a second electrode mounted on the electromechanical transducer film. The electromechanical transducer film includes a {100} plane preferentially oriented to be orthogonal to a thickness direction of the electromechanical transducer film and has a full width at half maximum corresponding to a {200} plane in an X-ray diffraction measurement curve in 2?-? scan that is measured by emitting an X-ray beam onto a surface of the electromechanical transducer film at an incident angle ?. The full width at half maximum is not greater than 10 degrees.

Abstract: A piezoelectric actuator includes a vibrating plate, a lower electrode provided on the vibrating plate, including a platinum film and a titanium oxide film formed on the platinum film, a piezoelectric thin film provided on the lower electrode, and an upper electrode provided on the piezoelectric thin film, in which the titanium oxide film is provided between the platinum film and the piezoelectric thin film.

Abstract: An electromechanical transducer includes a first electrode mounted on one of a substrate and a base film, an electromechanical transducer film mounted on the first electrode and made of a piezoelectric substance having a perovskite crystal structure, and a second electrode mounted on the electromechanical transducer film. The electromechanical transducer film includes a {100} plane preferentially oriented to be orthogonal to a thickness direction of the electromechanical transducer film and has a full width at half maximum corresponding to a {200} plane in an X-ray diffraction measurement curve in 2?-? scan that is measured by emitting an X-ray beam onto a surface of the electromechanical transducer film at an incident angle ?. The full width at half maximum is not greater than 10 degrees.