Drive control circuit that drives vibrator, driving method, vibration-type driving apparatus, and image pickup apparatus

Patent metadata

Field	Value
Publication number	US-2016226402-A1
Application number	US-201615010396-A
Country	US
Kind code	A1
Filing date	Jan 29, 2016
Priority date	Jan 30, 2015
Publication date	Aug 4, 2016
Grant date	—

Abstract

A drive control circuit which restores holding force when a vibrator and a driven body have been left at a standstill for a long time period and when they are used in a high-humidity environment. A drive circuit outputs an alternating-current signal, which is to be applied to an electro-mechanical energy conversion element, based on an output from a control unit. The control circuit controls the drive circuit with first timing such that elliptical motion produced in the vibrator takes a path of which a component parallel to a driving direction of the driven body is large as compared to such a path that a speed at which the driven body is driven is the maximum. The first timing is different from second timing with which relative positions of the vibrator and the driven body are changed.

First claim

What is claimed is:

1 . A drive control circuit that drives one or a plurality of vibrators each having an electro-mechanical energy conversion element and a driving unit that comes into contact with a driven body, and moving the driven body and the driving unit relatively to each other through elliptical motion produced in the driving unit by application of an alternating-current signal to the electro-mechanical energy conversion element, comprising:
a control unit; and a drive circuit configured to output the alternating-current signal, which is to be applied to the electro-mechanical energy conversion element, based on an output from said control unit, wherein with first timing, said control unit controls said drive circuit such that the elliptical motion takes a path of which a component parallel to a driving direction of the driven body is large as compared to such a path that a speed at which the driven body is driven is the maximum, and the first timing is different from second timing with which relative positions of the driving unit and the driven body are changed.

2 . The drive control circuit according to claim 1 , wherein in driving the plurality of vibrators, said control unit controls said drive circuit with the first timing such that one of the plurality of vibrators is brought to a standstill, and the elliptical motion produced in the driving units of the rest of the vibrators take a path of which a component parallel to the driving direction of the driven body is large.

3 . The drive control circuit according to claim 1 , wherein the first timing is later than turning-on of power supply to the drive control circuit and earlier than relative movement of the vibrator and the driven body.

4 . The drive control circuit according to claim 1 , wherein the first timing is earlier than turning-off of power supply to the drive control circuit.

5 . The drive control circuit according to claim 1 , wherein the first timing corresponds to a time at which a predetermined time period has elapsed with relative positions of the vibrator and the driven body unchanged.

6 . The drive control circuit according to claim 1 , further comprising detection unit for detecting a position of the driven body, wherein the first timing is later than said detection unit detecting the driven body having moved to a target position.

7 . A driving method for driving one or a plurality of vibrators each having an electro-mechanical energy conversion element and a driving unit that comes into contact with a driven body, and moving the driven body and the driving unit relatively to each other through elliptical motion produced in the driving unit by application of an alternating-current signal to the electro-mechanical energy conversion element, comprising:
a step of, with timing different from timing with which relative positions of the driving unit and the driven body are changed, providing driving control using a drive control circuit to drive the vibrator such that the elliptical motion takes a path of which a component parallel to a driving direction of the driven body is large as compared to such a path that a speed at which the driven body is driven is the maximum.

8 . The driving method according to claim 7 , wherein in driving the plurality of vibrators, one of the plurality of vibrators is brought to a standstill, and the elliptical motion produced in the driving units of the rest of the vibrators take a path of which a component parallel to the driving direction of the driven body is large.

9 . A vibration-type driving apparatus comprising:
one or a plurality of vibrators each configured to have an electro-mechanical energy conversion element and an elastic body with a first side to which the electro-mechanical energy conversion element is joined, and have a projecting portion provided on a second side opposite to the first side; a driven body configured to come into pressure contact with the projecting portion; and a drive control circuit configured to drive said vibrator, wherein elliptical motion is produced in the projecting portion to move said vibrator and said driven body relatively to each other, and said drive control circuit comprises: a control unit; and a drive circuit that outputs an alternating-current signal, which is to be applied to the electro-mechanical energy conversion element so as to excite the elliptical motion in the projecting portion, based on an output from the control unit, wherein with first timing, the control unit controls the drive circuit such that the elliptical motion takes a path of which a component parallel to a driving direction of said driven body is large as compared to such a path that a speed at which said driven body is driven is the maximum, and the first timing is different from second timing with which relative positions of said vibrator and said driven body are changed.

10 . An image pickup apparatus comprising:
a vibration-type driving apparatus; a lens configured to be driven by a driven body of said vibration-type driving apparatus; an image pickup device configured to be provided at a location which light having passed through said lens forms an image, wherein said vibration-type driving apparatus comprises: one or a plurality of vibrators that comprises an electro-mechanical energy conversion element and an elastic body that has a first side to which the electro-mechanical energy conversion element is joined, and has a projecting portion on a second side opposite to the first side; a driven body that comes into pressure contact with the projecting portion; and a drive control circuit that drives the vibrator, wherein elliptical motion is produced in the projecting portion to move the vibrator and the driven body relatively to each other, and the drive control circuit comprises: a control unit; and a drive circuit that outputs an alternating-current signal, which is to be applied to the electro-mechanical energy conversion element so as to excite the elliptical motion in the projecting portion, based on an output from the control unit, wherein with first timing, the control unit controls the drive circuit such that the elliptical motion takes a path of which a component parallel to a driving direction of the driven body is large as compared to such a path that a speed at which the driven body is driven is the maximum, and the first timing is different from second timing with which relative positions of the vibrator and the driven body are changed.

Assignees

• Canon Kk

Inventors

• Morita Hiromitsu
• Sumioka Jun
• Yamamoto Shinji

Classifications

• H02N2/0015

  using only bending modes · CPC title

• H02N2/103

  by pressing one or more vibrators against the rotor · CPC title

• H02N2/026

  by pressing one or more vibrators against the driven body · CPC title

• H02N2/0075 Primary

  Electrical details, e.g. drive or control circuits or methods · CPC title