A multi-axis MEMS assembly includes: a micro-electrical-mechanical system (MEMS) actuator configured to provide linear three-axis movement, the micro-electrical-mechanical system (MEMS) actuator including: an in-plane MEMS actuator, and an out-of-plane MEMS actuator including a multi-morph piezoelectric actuator; an optoelectronic device coupled to the in-plane MEMS actuator; and a lens barrel assembly coupled to the out-of-plane MEMS actuator.

A vibration device includes a vibrator including a cylinder including an opening, a light-transmissive cover directly or indirectly coupled to the cylinder to cover the opening of the cylinder, and a piezoelectric element to vibrate the light-transmissive cover, and including an opening end portion, an elastic member holding the opening end portion of the vibrator, and a case connected to the elastic member.

A vibration-type actuator includes a vibrating body including an annular elastic member and an electric-mechanical energy conversion element, and an annular contact body configured to move relative to the vibrating body. The contact body includes a base portion, a support portion annularly extending from the base portion in a radial direction of the contact body, and a friction member provided at the support portion, formed separately from the support portion, and being in contact with the vibrating body. The friction member includes a first part extending in a direction along a central axis of the annular contact body, and a second part extending in the radial direction, the first part and the second part being connected to the support portion. The first part includes a portion that is connected by being either internally or externally fitted to the support portion in the radial direction.

A vibration device includes a light-transmitting body that is located on a subject side of an imaging element, a cylindrical body that includes a first end portion, a second end portion on the opposite side from the first end portion, and an outer surface and an inner surface that connect the first end portion and the second end portion to each other, the cylindrical body being connected to the light-transmitting body and holding the light-transmitting body on the first end portion side thereof, and a piezoelectric element provided along a circumferential direction of the cylindrical body and that torsionally vibrates the cylindrical body.

A camera module includes a first circuit board on which the image sensor is mounted; a plurality of lens barrels spaced apart from the first circuit board; a carrier on which the plurality of lens barrels are mounted and configured to move along a plane intersecting an optical axis so as to align any one of the plurality of the lens barrel with the image sensor; an actuator configured to move the carrier to each of an optical axis direction and a direction intersecting the optical axis direction; and a housing receiving therein at least a portion of each of the lens barrels and the actuator.

An optical system is provided. The optical system includes a first assembly and a second assembly. The first assembly includes a first welding portion. The second assembly is affixed on the first assembly and includes a second welding portion. The first welding portion is affixed on the second welding portion by welding.

A lens holder driving device includes a first piezoelectric driver configured to move a first lens holder along an optical-axis direction based on the movement of a first piezoelectric element and a second piezoelectric driver configured to move a second lens holder along the optical-axis direction based on the movement of a second piezoelectric element. The first lens holder includes a portion (first left-bearing portion) near a first shaft member and a portion near a second shaft member. The first piezoelectric driver is provided in the first left-bearing portion and contacts the first shaft member. The second lens holder incudes a portion near the first shaft member and a portion (second right-bearing portion) near the second shaft member. The second piezoelectric driver is provided in the second right-bearing portion and contacts the second shaft member.

A lens apparatus is provided with movable first and second units, first and second holders for holding the first and second units, a driving unit for electrically driving the second holder, a transmission member movable relative to the second holder in the optical axis direction and transmits driving force to the second holder, a biasing member for biasing the second holder toward the first holder side relative to the transmission member, a controller for controlling the driving unit, and first and second detectors for detecting the positions of the first and second holders, wherein movable ranges of the first and second holders have interference region which interfere with each other, and controller changes a control of driving unit between the interference region where the first and the second holding members interfere each other and an interference-free region based on detection results of the first and second detectors.

A vibration actuator control apparatus includes a control amount output unit. The control amount output unit includes a trained model trained by machine learning configured to output a control amount, if the target speed and a value based on the target position are input to the trained model, to move the contact body relative to the vibrator. The value based on the target position is a value based on a product of first and second values. The first value is a value based on a difference between the target position and a detection position detected from the vibration actuator moved based on the control amount. The second value is a value based on a ratio between the control amount output from the control amount output unit and a value output from the trained model if the target speed and a predetermined value are input to the trained model.

A lens apparatus includes a base barrel, a lens movable to an object side and an image side relative to the base barrel, an actuator configured to move the lens, a drive board that includes an electric element configured to drive the actuator, and a board holding member configured to hold the drive board and attached to the base barrel from the object side.