Actuator drive device

Patent metadata

Field	Value
Publication number	US-9520813-B2
Application number	US-201214237804-A
Country	US
Kind code	B2
Filing date	Oct 23, 2012
Priority date	Oct 27, 2011
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

An actuator drive device is configured to drive an actuator. The actuator drive device includes a storage section for storing a drive condition of the actuator, a processor for calculating and outputting drive signal D(t) based on a drive base signal V(t) calculated based on the drive condition with respect to time t, and a generator for outputting, based on the drive signal D(t) calculated, a driving signal for driving the actuator. The drive base signal V(t) is a sum of a fundamental wave and at least one harmonic wave of the fundamental wave. The processor is operable to determine the coefficient a k such that the drive base signal V(t) changes linearly from a minimum value to a maximum value with respect to a time. This actuator drive device improves the linearity of the driving of the actuator.

First claim

The invention claimed is:

1. An actuator drive device configured to drive an actuator which includes a driver and a drive electrode, said actuator drive device comprising:
a storage section for storing a drive condition of the actuator;
a processor for calculating and outputting drive signal D(t) based on a drive base signal V(t) calculated based on the drive condition with respect to time t; and
a generator for outputting, based on the drive signal D(t) calculated, a driving signal to the drive electrode of the actuator for driving the driver of the actuator,
wherein the actuator drive device is configured to drive the actuator in a main mode while not exciting the actuator in a mode different from the main mode,
wherein the drive base signal V(t) is a sum of a fundamental wave and at least one harmonic wave of the fundamental wave, and is expressed as:

V
⁡

(
t
)

=

A
⁢

∑

k
=
1

N

⁢

a
k

⁢

sin
⁡

(

2
⁢
π
⁢

⁢

f
base

⁢
kt

)

,

with an amplitude A, an integer N, a coefficient a k , a frequency f base of the fundamental wave, and an integer k (1≦k≦N),
wherein frequencies of the fundamental wave and the at least one harmonic wave of the fundamental wave includes a resonance frequency f 0 of the main mode,
wherein the mode, different from the main mode, is excited with a vibration at a resonance frequency f 1 ,
wherein an upper limit frequency out of the frequencies of the fundamental wave and the at least one harmonic wave of the fundamental wave is a frequency f BW ,
wherein a frequency kf base of a harmonic wave out of the at least one harmonic wave at any order k is included within a range of f base ≦kf base ≦f BW ≦f 1 , and
wherein the processor is operable to determine the coefficient a k such that the drive base signal V(t) changes linearly from a minimum value to a maximum value with respect to a time.

2. The actuator drive device according to claim 1 , wherein the processor outputs the drive base signal V(t) as the drive signal D(t).

3. The actuator drive device according to claim 1 , wherein the drive signal D(t) is expressed as:
D ( t )= V ( t )+ X,

with the drive base signal V(t) and a bias X.

4. The actuator drive device according to claim 1 ,
wherein an evaluation function S is expressed as:

S
=

∑

T
/
2

-

Δ
⁢

⁢
t

T
/
2

+

Δ
⁢

⁢
t

⁢



V
⁡

(
t
)

-

(

mt
+
n

)



2

with a period T(=1/f base ) of the drive base signal V(t), a duration Δt which is a half of a duration from the minimum value to the maximum value, and integers m and n, and
wherein the coefficient a k is determined to satisfy S/N S <0.0015 with a discrete value N S of the time t.

5. The actuator drive device according to claim 1 ,
wherein an evaluation function S is expressed as:

S
=

∑

T
/
2

-

Δ
⁢

⁢

Assignees

• Panasonic Corp
• Panasonic Ip Man Co Ltd

Inventors

• Yamamoto Yuta
• Nakazono Shinsuke
• Kurozuka Akira

Classifications

• H02N2/0075 Primary

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

• H01L41/042

  Electricity · mapped topic

• G02B26/0858 Primary

  the reflecting means being moved or deformed by piezoelectric means · CPC title

• H10N30/802

  Circuitry or processes for operating piezoelectric or electrostrictive devices not otherwise provided for, e.g. drive circuits · CPC title