Nikon Corporation

Takatoshi Ashizawa

Tadao Takagi

Mitsuhiro Okazaki

Kazuyasu Oone

Isao Sugaya

Toshikazu Morioke

Shinji Nishihara

Ryoichi Suganuma

Daisuke Saya

Mina Kobayashi

Azusa Muto

Tsuyoshi Matsumoto

Yoshiro Tomikawa

Tsutomu Narisawa

Kunihiro Kuwano

Michihiro Tobe

Hirofumi Takahashi

Mine Sumitomo

Masamitsu Kimura

Tomohiko Yokoo

Kazutaka Watanabe

A vibrator includes an electromechanical transducer which is a piezoelectric ceramic made of sodium-potassium niobate metal oxides and whose temperature characteristics of a relative permittivity is 500 [ppm/° C.] or less in absolute value in a temperature range from −40° C. to 170° C., wherein excitation of the electromechanical transducer produces a vibration wave. Another vibrator includes an electromechanical transducer which is a piezoelectric ceramic made of sodium-potassium niobate metal oxides and whose temperature characteristics of a relative permittivity is 390 [ppm/° C.] or less in absolute value in a temperature range from 0° C. to 60° C., wherein excitation of the electromechanical transducer produces a vibration wave.

Vibrator and vibration wave motor

A lens barrel includes an element displaced by application of voltage; an elastic body having a contact surface coming into contact with the element, a drive surface to produce a vibration wave by displacement of the element, and a plurality of grooves; a moving element come into contact with the drive surface and rotated by the vibration wave; an annular ring rotated by rotating of the moving element; and a lens moved in an optical axis direction by rotating of the annular ring; wherein the element mainly contains a material having potassium sodium niobate, potassium niobate, sodium niobate, or barium titanate, wherein a value of [(T/B)&#xf7;W] is in a range of 0.84 to 1.94, where T represents a depth of the groove, B represents a distance from a bottom part of the groove to the contact surface, and W represents a radial width of the elastic body.

Lens barrel and imaging device with element and elastic body for producing vibration wave

A lens barrel includes: an electromechanical conversion element; an elastic body having a joining surface, a drive surface, and grooves; a motion member rotating by vibration wave of the drive surface; a rotating ring having a recess part and rotating by rotation of the motion member; a moving ring engaged to the recess part and moving to an optical axis direction by rotation of the rotating ring; and a lens held in the moving ring; wherein the element is made of a material having sodium potassium niobate, potassium niobate, sodium niobate or barium titanate, wherein a value of T/(B+C) is within a range of from 1.3 to 2.8 when: length from the drive surface to a base unit of the groove is defined as T; length from the base unit of the groove to the joining surface is defined as B; and thickness of the element is defined as C.

Lens barrel and imaging device

A vibration wave motor includes an element configured to be displaced by application of voltage, and an annular elastic body having a bottom surface coming into contact with the element and a drive surface having a groove, configured to drive a moving element by a vibration wave produced on the drive surface by displacement of the element. The element has a density of 4.2 to 6.0&#xd7;10kg/m. A value of [(T/B)&#xf7;W] is in a range of 0.84 to 1.94, where T represents a depth of the groove, B represents a distance from a bottom part of the groove to the bottom surface, and W represents a radial width of the elastic body.

Vibration wave motor and optical device

A vibration wave motor comprises: an electromechanical conversion element; an elastic body which has a drive surface on which a vibration wave is generated due to vibration of the electromechanical conversion element; and a relative motion member which makes contact with the drive surface of the elastic body and is configured to rotationally drive by the vibration wave, the electromechanical conversion element having a density of from 4.2 to 6.0&#xd7;10kg/m, a plurality of grooves being provided on the drive surface side of the elastic body, and a value of T/(B+C) being within a range of from 1.3 to 2.8 when: depth of at least one groove of the plurality of grooves is defined as T; thickness from a base unit of the groove to a first surface is defined as B; and thickness of the electromechanical conversion element is defined as C.

Noise produced during phase-difference changes is minimized without decreasing the responsiveness of a vibration-wave motor. A lens-side MCU for a lens barrel controls a drive apparatus that applies a drive voltage to the vibration-wave motor by outputting an A-phase drive signal and a B-phase drive signal thereto. The lens-side MCU uses, for example, a drive-voltage setting unit and a duty-cycle change unit to change the drive voltage. Also, the lens-side MCU is provided with a phase-difference change unit that changes the phase difference between the A-phase drive signal and the B-phase drive signal. When driving the vibration-wave motor, the lens-side MCU changes the drive voltage to V, and when the phase-difference change unit is changing the aforementioned phase difference, the drive voltage is changed to V, Vbeing greater than zero and less than V.

Drive apparatus, drive method, and optical device

Noise produced during phase-difference changes is minimized without decreasing the responsiveness of a vibration-wave motor. A lens-side MCU for a lens barrel (controls a drive apparatus that applies a drive voltage to the vibration-wave motor by outputting an A-phase drive signal and a B-phase drive signal thereto. The lens-side MCU uses, for example, a drive-voltage setting unit and a duty-cycle change unit to change the drive voltage. Also, the lens-side MCU is provided with a phase-difference change unit that changes the phase difference between the A-phase drive signal and the B-phase drive signal. When driving the vibration-wave motor, the lens-side MCU changes the drive voltage to Vreg, and when the phase-difference change unit is changing the aforementioned phase difference, the drive voltage is changed to V, Vbeing greater than zero and less than Vreg.

Provided is a lens barrel includes a vibration actuator that drives a focusing lens which brings a subject image into focus; an amplifying section that applies a pair of driving signals amplified to the vibration actuator; a phase shifting section that changes a phase difference between the pair of the driving signals; and a control section that, when a signal for giving an instruction to drive the vibration actuator is input, executes a first processing of causing the phase shifting section to perform an operation which periodically changes the phase difference of the pair of the driving signals.

Driving device, lens barrel, and image capturing apparatus

A lens barrel includes a linear vibration actuator and a lens ring. The linear vibration actuator includes a vibrating element, relative motion member and pressurizing mechanism. The vibrating element generates a driving force at a driving face in parallel with an optical axis by oscillation of an electromechanical conversion element. The relative motion member is in pressure contact with the driving face and linearly moves in parallel with the optical axis with respect to the vibrating element. The pressurizing mechanism applies a pressure force between the driving face and the relative motion member. The lens ring holds a photographic lens and is linearly moved by the relative motion member in parallel with the optical axis. The linear vibration actuator includes a first linear guide receiving the pressure force applied to the relative motion member, and the lens ring includes a second linear guide guiding the lens ring to linearly move.

Lens barrel and camera

A vibrational wave motor includes a motor main body and pressing member. The motor main body includes an electromechanical conversion element, elastic body and relative motion member. The elastic body joined to the electromechanical conversion element generates an oscillating wave. The relative motion member in pressure contact with the elastic body is rotationally driven relative to the elastic body. The pressing member generates a pressing force between the elastic body and relative motion member. The pressing member includes a pressure applying portion, extension portion and pressing main body. The pressure applying portion presses one of the elastic body and the relative motion member towards the other, along a rotation axis. The extension portion extends outward from the pressure applying portion in a radial direction centered about the rotation axis. The pressing main body is disposed more outward in the radial direction than the motor main body at the extension portion.

Vibrational wave motor, lens barrel and camera

A piezoelectric actuator having reduced sizes, a lens barrel and an optical device. A piezoelectric actuator is provided with: a first actuator including first piezoelectric elements to be displaced in a first direction; a second actuator, which includes second piezoelectric elements to be displaced in a second direction intersecting with the first direction, and is arranged in a direction intersecting with the first direction with respect to the first actuator; and a relative displacement member, which is arranged between the first actuator and the second actuator and can be relatively displaced in the first direction with respect to the first actuator.

Piezoelectric actuator, lens barrel and optical device

A vibrational wave motor which can realize a suitable drive performance and can be driven quietly. The vibrational wave motor includes: an electromechanical-conversion element excited by a driving signal; a vibrating element joined with the electromechanical-conversion element, and having a drive surface where a progressive vibrational wave is generated by the excitation; a relative motion member having a sliding surface pressure-contacting the drive surface of the vibrating element, and which is driven by the wave; and a driving device for providing the driving signal to the electromechanical-conversion element, wherein: the driving device provides the driving signal to the electromechanical-conversion element, the driving signal generating the wave satisfying a-value/&#x3bb;&#x2266;0.00025 in the drive surface, where a vibration amplitude generated in the drive surface of the vibrating element is a-value, and a wavelength generated in the drive surface of the vibrating element is &#x3bb;.

Disclosed is a piezoelectric actuator which has an improved driving force or drive efficiency. Specifically disclosed is a piezoelectric actuator which is provided with: a plurality of piezoelectric members which have a first piezoelectric element capable of being displaced in a first direction and a second piezoelectric element capable of being displaced in a second direction intersecting the first direction, and which are divided into a plurality of groups; a relative movement member which has a contact surface that is in contact with the piezoelectric members, and which moves relatively to the piezoelectric members in the first direction; and a drive unit which, when piezoelectric members of one group among the plurality of groups are in contact with the contact surface, drives the first piezoelectric element of the piezoelectric members.

Piezoelectric actuator, lens barrel, and camera

A piezoelectric actuator comprises a first piezoelectric element pre-polarized towards a first direction and displaceable towards an about orthogonal direction with respect to said first direction, a second piezoelectric element pre-polarized towards a direction about parallel to the first direction and displaceable towards a direction about parallel to said first direction, a relative moving member clamped by displacement of said first piezoelectric element and relatively moves by displacement of said second piezoelectric element.

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Yokohama, Japan

Takatoshi Ashizawa