U.S. patent application number 12/734810 was filed with the patent office on 2011-02-10 for driving module and electronic apparatus provided with the same.
Invention is credited to Akira Kume.
Application Number | 20110030368 12/734810 |
Document ID | / |
Family ID | 40678465 |
Filed Date | 2011-02-10 |
United States Patent
Application |
20110030368 |
Kind Code |
A1 |
Kume; Akira |
February 10, 2011 |
DRIVING MODULE AND ELECTRONIC APPARATUS PROVIDED WITH THE SAME
Abstract
Disclosed are a driving module that can reduce fears of breakage
and failures due to impact force caused by dropping or the like and
can be miniaturized, and an electronic apparatus provided with the
driving module. The driving module includes: a lens frame (4); a
module frame (5) housing the lens frame (4) in an inside thereof;
an upper plate spring (6); and an SMA wire (10) for driving the
lens frame (4) along a predetermined direction against a biasing
force of the upper plate spring (6). The lens frame (4) is provided
with, in a cylinder end portion or a column end portion of the lens
frame (4) in a circumferential direction, caulking portions (16)
that sandwich the upper plate spring (6) with the lens frame (4) so
as to fix the upper plate spring (6) to the lens frame (4), and the
module frame (5) is provided with, in a cylinder end portion of the
module frame (5) in the circumferential direction, caulking
portions (17) that sandwich the upper plate spring (6) with the
module frame (5) so as to fix the upper plate spring (6) to the
module frame (5). The caulking portions (16) and the caulking
portions (17) are placed while angular positions in the
circumferential direction with respect to a center axis of the lens
frame (4) are shifted.
Inventors: |
Kume; Akira; (Chiba,
JP) |
Correspondence
Address: |
Bruce L Adams;Adams & Wilks
17 Battery Place, Suite 1231
New YOrk
NY
10004
US
|
Family ID: |
40678465 |
Appl. No.: |
12/734810 |
Filed: |
November 25, 2008 |
PCT Filed: |
November 25, 2008 |
PCT NO: |
PCT/JP2008/071288 |
371 Date: |
October 7, 2010 |
Current U.S.
Class: |
60/527 |
Current CPC
Class: |
H04N 5/2257 20130101;
G03B 3/10 20130101; G02B 7/04 20130101; G02B 7/023 20130101; H04N
5/2254 20130101 |
Class at
Publication: |
60/527 |
International
Class: |
F01B 29/10 20060101
F01B029/10 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 27, 2007 |
JP |
2007-305338 |
Claims
1. A driving module, comprising: a cylindrical or columnar body to
be driven; a cylindrical support housing the body to be drive in an
inside thereof; a plate spring member that holds elastically the
body to be driven with respect to the support so that the body to
be driven is movable in a predetermined direction; and driving
means for driving the body to be driven in the predetermined
direction against a biasing force of the plate spring member,
wherein: the body to be driven is provided with, in a cylinder end
portion or a column end portion of the body to be driven in a
circumferential direction, a plurality of first plate spring fixing
portions that sandwich the plate spring member with the body to be
driven so as to fix the plate spring member to the body to be
driven; the support is provided with, in a cylinder end portion of
the support in the circumferential direction, a plurality of second
plate spring fixing portions that sandwich the plate spring member
with the support so as to fix the plate spring member to the
support; and the first plate spring fixing portions and the second
plate spring fixing portions are placed while angular positions in
the circumferential direction with respect to a center axis of the
body to be driven are shifted on a plane orthogonal to the center
axis.
2. A driving module according to claim 1, wherein a cylinder outer
circumferential portion of the support is formed in a polygonal
shape, and each of the second plate spring fixing portions is
provided in a corner of a polygon of the support.
3. A driving module according to claim 2, wherein: the driving
means comprises a shape memory alloy wire that is stretched across
the cylinder outer circumferential portion of the support and
drives the body to be driven against the biasing force of the plate
spring member; the body to be driven comprises a protrusion that
locks the shape memory alloy wire; the support is provided with a
protrusion insertion portion that allows the protrusion to be
inserted in the corner of the polygon in a radial direction and to
move in the predetermined direction; and each of the second plate
spring fixing portions in the corner in which the protrusion
insertion portion is formed is placed adjacent to the protrusion
insertion portion in the circumferential direction.
4.-8. (canceled)
Description
TECHNICAL FIELD
[0001] The present invention relates to a driving module and an
electronic apparatus provided with the same. For example, the
present invention relates to a driving module, which is suited for
adjusting a focal position by driving an optical system or a mobile
member or for being used as an actuator, and relates to an
electronic apparatus provided with the driving module.
BACKGROUND ART
[0002] Conventionally, for example, in small electronic apparatuses
such as mobile phones with cameras, various types of driving
modules for driving a body to be driven such as a photographing
lens unit have been used.
[0003] As such a driving module, for example, Patent Document 1
describes an autofocus device whose both ends in an axial direction
are sandwiched by a holder spring while a lens holder holding a
focus lens in an inner circumferential portion and having a driving
coil attached to an outer circumferential portion is inserted in an
annular magnet.
[0004] Patent Document 1: JP 2005-173431 A
DISCLOSURE OF THE INVENTION
Problems To Be Solved By the Invention
[0005] In the autofocus device described in Patent Document 1, the
holder spring connects an inside ring to an outside ring with a
connecting spring, the inside ring is attached to the lens holder
that is a body to be driven, and the outside ring is attached to a
ring-shaped magnet via a ring-shaped spacer. Patent Document 1 does
not describe an attachment method, and no fixing means is
illustrated in the figures. Thus, adhesion with an adhesive is
considered to be used from the technical common sense.
[0006] In the case of adhering the holder spring made of metal to
the lens holder and the magnet, there is a problem in that high
reliability cannot be obtained in terms of adhesive strength
because the lens holder and the magnet to which the holder spring
is adhered are made of different materials. Further, in the case
where the adhered portion receives impact force caused by dropping
or the like, there is a problem in that the adhered portion is
likely to be damaged. Further, even if such peeling does not occur
in the adhered portion that the holder spring does not peel off,
when even a part of the adhered portion is degraded, a spring
constant changes. Therefore, elastic restoring force changes, and
there is a fear that precise driving may not be performed.
[0007] On the other hand, for example, in the case of adopting a
fixing method such as screwing or caulking so as to increase fixing
strength, there is a problem in that a large space for fixing is
required compared with a space for adhesion.
[0008] The present invention is dedicated for solving the
conventional problems, and it is an object of the present invention
to provide a driving module that can reduce the risks of breakage
and failures due to impact force caused by dropping or the like and
can be miniaturized, and an electronic apparatus provided with the
driving module.
Means For Solving the Problems
[0009] In order to achieve the above-mentioned object, in the
invention according to claim 1, a driving module includes: a
cylindrical or columnar body to be driven; a cylindrical support
housing the body to be driven in an inside thereof; a plate spring
member that holds elastically the body to be driven with respect to
the support so that the body to be driven is movable in a
predetermined direction; and driving means for driving the body to
be driven in the predetermined direction against a biasing force of
the plate spring member, in which: the body to be driven is
provided with, in a cylinder end portion or a column end portion of
the body to be driven in a circumferential direction, a plurality
of first plate spring fixing portions that sandwich the plate
spring member with the body to be driven so as to fix the plate
spring member to the body to be driven; the support is provided
with, in a cylinder end portion of the support in the
circumferential direction, a plurality of second plate spring
fixing portions that sandwich the plate spring member with the
support so as to fix the plate spring member to the support; and
the first plate spring fixing portions and the second plate spring
fixing portions are placed while angular positions in the
circumferential direction with respect to a center axis of the body
to be driven are shifted on a plane orthogonal to the center
axis.
[0010] According to the present invention, the first plate spring
fixing portions that fix the plate spring member by sandwiching the
plate spring member with the cylinder end portion or the column end
portion of the body to be driven and the second plate spring fixing
portions that fix the plate spring member by sandwiching the plate
spring member with the cylinder end portion of the support are
placed while the angular positions in the circumferential direction
with respect to the center axis are shifted on the plane orthogonal
to the center axis of the body to be driven. Therefore, compared
with the case where the first and second plate spring fixing
portions are placed on a straight line directed from the center
axis of the body to be driven to the outside in a radial direction,
the positions in the radial direction of the first and second plate
spring fixing portions can be made close to each other, and a large
space required for screwing and caulking can be ensured.
[0011] In the invention according to claim 2, in the driving module
according to claim 1, a cylinder outer circumferential portion of
the support is formed in a polygonal shape, and each of the second
plate spring fixing portions is provided in a corner of a polygon
of the support.
[0012] According to the present invention, each of the second plate
spring fixing portions is provided at the corner of the polygon of
the cylinder outer circumferential portion of the support.
Therefore, in the case where the support is formed in a polygonal
shape, the protrusion amount of the outer shape for providing the
second plate spring fixing portions can be suppressed.
[0013] Further, in the case of forming the outer shape of the plate
spring member along the end shape of the support, the outer shape
is formed in accordance with the shape of the corner of the polygon
of the cylinder outer circumferential portion of the support, and
the portion to be fixed can be provided at the corner of the plate
spring member having a space with a distance from the arc-shaped
plate spring portion on the inner circumferential side. Therefore,
the production of the plate spring member by precise punching and
the production by etching are facilitated.
[0014] In the invention according to claim 3, in the driving module
according to claim 2, the driving means includes a shape memory
alloy wire that is stretched across the cylinder outer
circumferential portion of the support and drives the body to be
driven against the biasing force of the plate spring member, and
the body to be driven includes a protrusion that locks the shape
memory alloy wire. The support is provided with a protrusion
insertion portion that allows the protrusion to be inserted in the
corner of the polygon in a radial direction and to move in the
predetermined direction, and each of the second plate spring fixing
portions in the corner in which the protrusion insertion portion is
formed is placed adjacent to the protrusion insertion portion in
the circumferential direction.
[0015] According to the present invention, the protrusion of the
body to be driven, which is to be housed in the inside of the
support, is inserted in the cut-away portion of the support, and
locked with the shape memory alloy wire stretched across the
cylinder outer circumferential portion of the support, whereby the
body to be driven can be driven in the axial direction of the
center axis of the body to be driven with the contraction force of
the shape memory alloy wire and the biasing force from the plate
spring member. At this time, the protrusion insertion portion of
the support, i.e., the position of the protrusion of the body to be
driven corresponds to the corner of the polygon of the support.
Therefore, the shape memory alloy wire can be stretched along the
polygon side surface of the support, and the shape memory alloy
wire can be placed easily.
[0016] Further, each of the second plate spring fixing portions at
the corner in which the protrusion insertion portion is formed is
placed adjacent to the protrusion insertion portion in the
circumferential direction, and hence, the protrusion insertion
portion can be formed in a cut-away shape opening on one side in
the axial direction of the inner circumferential portion of the
support. Therefore, the configuration of the support can be
simplified, which makes the assembly of the driving module
easy.
[0017] Further, in the case of using the plate spring member with
the outer shape of a polygon in accordance with the shape of the
cylinder end portion of the support, the corner of the plate spring
member becomes the portion to be fixed, and hence, the plate spring
member can be fixed stably.
[0018] In the invention according to claim 4, in the driving module
according to any one of claims 1 to 3, the body to be driven
includes a convex portion that protrudes in the radial direction in
an outer circumferential portion of a cylindrical or columnar main
part of the body to be driven, and each of the first plate spring
fixing portions is formed on an end side of the convex portion.
[0019] According to the present invention, each of the first plate
spring fixing portions is provided on the end side of the convex
portion protruding in the radial direction in the outer
circumferential portion of the cylindrical or columnar main part of
the body to be driven. Therefore, when the body to be driven is
housed in the support, the support and the body to be driven can
intrude into each other in the radial direction, and the shape
engaged with each other in the intruded portion can be provided.
Therefore, a space in the circumferential direction adjacent to the
convex portion can be used effectively.
[0020] In the invention according to claim 5, in the driving module
according to any one of claims 1 to 4, an inner circumferential
surface of the support is provided with a position regulating
portion that regulates a movement range of the body to be driven in
the predetermined direction, and the outer circumferential portion
of the body to be driven is provided with a portion whose position
is to be regulated, and which is placed so as to abut against the
position regulating portion of the support.
[0021] According to the present invention, the portion whose
position is to be regulated of the body to be driven abuts against
the position regulating portion of the support in the predetermined
direction, whereby the movement range of the body to be driven is
regulated. Therefore, for example, even at an abnormal time such as
dropping, the movement range of the body to be driven can be
regulated to an appropriate range, for example, the range avoiding
the collision with other members.
[0022] The position regulating portion is provided on an inner side
of the support, and hence the outer shape of the support and the
length of the driving direction are not required to increase. Thus,
the miniaturization can be achieved.
[0023] In the case of using the plate spring member for the driving
means, the movement range can be regulated to the range
corresponding to the deformation limit of the plate spring
member.
[0024] In the invention according to claim 6, in the driving module
according to claim 5, the position regulating portion of the
support is provided on an inner side in the radial direction with
respect to the second plate spring fixing portions, and the portion
whose position is to be regulated of the body to be driven is
formed at a position adjacent to each of the first plate spring
fixing portions in the circumferential direction.
[0025] According to the present invention, the position regulating
portion is provided on the inner side in the radial direction with
respect to the second plate spring fixing portions, and the portion
whose position is to be regulated is provided at the position
adjacent to each of the first plate spring fixing portions in the
circumferential direction. Therefore, the position regulating
portion and the portion whose position is to be regulated are
provided so as to abut against each other at the position adjacent
to each of the first plate spring fixing portions in the
circumferential direction. Therefore, the space adjacent to each of
the first plate spring fixing portions in the circumferential
direction can be used efficiently.
[0026] In the invention according to claim 7, the driving module
according to any one of claims 1 to 6 includes a cover member that
covers the support at least on the second plate spring fixing
portions, in which the cover member is provided with a run-off in a
concave shape in a plate thickness range of the cover member at a
position opposed to each of the second plate spring fixing
portions.
[0027] According to the present invention, the run-off provided in
the cover member can prevent the collision between the second plate
spring fixing portions and the cover member without allowing the
outer surface of the cover member from protruding in the plate
thickness direction.
[0028] In the invention according to claim 8, an electronic
apparatus includes the driving module according to any one of
claims 1 to 7.
[0029] According to the present invention, due to the presence of
the driving module according to any one of claims 1 to 7, the
function similar to that of the invention according to any one of
claims 1 to 7 is provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] [FIG. 1] A schematic perspective view illustrating an
attachment state of a driving module according to Embodiment 1 of
the present invention with respect to a substrate.
[0031] [FIG. 2] An exploded perspective view illustrating a
schematic configuration of the driving module according to
Embodiment 1 of the present invention.
[0032] [FIG. 3] A schematic perspective view illustrating an
internal configuration of an assembled state of the driving module
according to Embodiment 1 of the present invention.
[0033] [FIG. 4] A cross-sectional view taken along the line A-A in
FIG. 3.
[0034] [FIGS. 5(a) and (b)] A cross-sectional view taken along the
line B-B in FIG. 3, and a cross-sectional view taken along the line
B-B in FIG. 3 at a time of movement of a body to be driven.
[0035] [FIGS. 6(a) and (b)] A perspective view of the body to be
driven used in the driving module according to Embodiment 1 of the
present invention and a plan view seen from the arrow C.
[0036] [FIGS. 7(a) and (b)] A perspective view of a support used in
the driving module according to Embodiment 1 of the present
invention and a back view seen from the arrow D.
[0037] [FIG. 8] A plan view of a plate spring member used in the
driving module according to Embodiment 1 of the present
invention.
[0038] [FIGS. 9(a) and (b)] A plan view of a plate member used in
the driving module according to Embodiment 1 of the present
invention and a front view thereof.
[0039] [FIG. 10] A back view seen from the arrow E in FIG.
9(b).
[0040] [FIG. 11] A plan view of a feeding member used in the
driving module according to Embodiment 1 of the present
invention.
[0041] [FIG. 12] A back view of a cover used in the driving module
according to Embodiment 1 of the present invention.
[0042] [FIG. 13] A schematic cross-sectional view illustrating a
configuration of a driving module according to a modification of
Embodiment 1 of the present invention.
[0043] [FIGS. 14(a) to (c)] External perspective views of a front
surface and a back surface of an electronic apparatus according to
Embodiment 2 of the present invention, and a cross-sectional view
taken along the line F-F.
BEST MODE FOR CARRYING OUT THE INVENTION
[0044] Hereinafter, embodiments of the present invention are
described with reference to the attached drawings. In all the
figures, the same or corresponding members are denoted with the
same reference symbols and the repeated description is omitted,
even in the case where embodiments are different.
Embodiment 1
[0045] A driving module according to Embodiment 1 of the present
invention is described.
[0046] FIG. 1 is a schematic perspective view illustrating an
attachment state of a driving module according to Embodiment 1 of
the present invention with respect to a substrate. FIG. 2 is an
exploded perspective view illustrating a schematic configuration of
the driving module according to Embodiment 1 of the present
invention. FIG. 3 is a schematic perspective view illustrating an
internal configuration of an assembled state of the driving module
according to Embodiment 1 of the present invention. FIG. 4 is a
cross-sectional view taken along the line A-A in FIG. 3. FIG. 5(a)
is a cross-sectional view taken along the line B-B in FIG. 3. FIG.
5(b) is a cross-sectional view taken along the line B-B in FIG. 3
at a time of movement of a body to be driven. FIG. 6(a) is a
perspective view of the body to be driven used in the driving
module according to Embodiment 1 of the present invention. FIG.
6(b) is a plan view seen from the arrow C in FIG. 6(a). FIG. 7(a)
is a perspective view of a support used in the driving module
according to Embodiment 1 of the present invention. FIG. 7(b) is a
back view seen from the arrow D in FIG. 7(a). FIG. 8 is a plan view
of a plate spring member used in the driving module according to
Embodiment 1 of the present invention. FIGS. 9(a) and (b) are a
plan view of a plate member used in the driving module according to
Embodiment 1 of the present invention and a front view thereof,
respectively. FIG. 10 is a back view seen from the arrow E in FIG.
9(b). FIG. 11 is a plan view of a feeding member used in the
driving module according to Embodiment 1 of the present invention.
FIG. 12 is a back view of a cover used in the driving module
according to Embodiment 1 of the present invention.
[0047] In a part of the drawings, for ease of seeing, components
such as the lens unit 12 are omitted appropriately.
[0048] The driving module of this embodiment is formed in a box
shape as a whole as illustrated in FIG. 1. The driving module 1 in
an assembled state is provided in an electronic apparatus or the
like and is fitted onto or adhered to a substrate 2 supplying a
control signal and power to the driving module 1, whereby the
driving module 1 can be fixed.
[0049] On an upper surface of the substrate 2, there are provided a
pair of land portions 3 connected to a feeding member of the
driving module 1 described later so as to supply power and an image
pickup element 30.
[0050] As illustrated in FIG. 2, the driving module 1 includes, as
main components, a lens frame 4 to be a body to be driven, a module
frame 5 to be a support, an upper plate spring 6 and a lower plate
spring 7 to be plate spring members, a module lower plate 8, a
feeding member 9, a shape memory alloy (hereinafter, abbreviated as
an SMA) wire 10, and a cover 11 (cover member), and those
components are stacked integrally to constitute one actuator.
[0051] In the assembled state of those members, as illustrated in
FIGS. 3 and 4, the lens frame 4 is inserted in the module frame 5;
the upper plate spring 6 and the lower plate spring 7 are fixed by
caulking while sandwiching the lens frame 4 and the module frame 5
in an up-and-down direction in the figure; the module lower plate 8
and the feeding member 9 are stacked in this order from the lower
side in the figure and fixed respectively by caulking from a lower
side of the module frame 5; and a cover 11 covering those laminates
from an upper side is fixed to the module lower plate 8.
[0052] A symbol M in the figure denotes a virtual axis of the
driving module 1 matched with the optical axis of the lens unit 12,
and indicates the driving direction of the lens frame 4. In the
following, for simplicity of the description, even in the
description of exploded components, the position and direction may
be referred to based on the positional relationship with the axis M
at a time of assembly. For example, even in the case where a clear
circle and cylindrical surface are not present in the components,
as long as there is no fear of misunderstanding, the direction
along the axis M may be referred to merely as an axial direction,
and a radial direction and a circumferential direction of a circle
with respect to the axis M may be referred to merely as a radial
direction and a circumferential direction.
[0053] Further, the up-and-down direction refers to an up-and-down
direction in the arrangement in the case where the axis M is placed
in a vertical direction and the attachment surface of the driving
module 1 is placed on a lower side of the vertical direction,
unless otherwise specified.
[0054] Among the components, the lens frame 4 to be the body to be
driven is formed in a tubular shape as a whole as illustrated in
FIGS. 2 and 6(a), and a female screw is formed on an inner
circumferential surface 4F of a housing portion 4A (main body of
the body to be driven) in a tubular shape, which passes through the
center of the lens frame 4 and is formed coaxially with the axis M.
Then, the lens unit 12 holding an appropriate lens or lens group on
a lens barrel with a male screw formed on an outer circumferential
portion (see FIGS. 4 and 5) can be screwed to be fixed to the
housing portion 4A.
[0055] On an outer wall surface 4B of the lens frame 4, protrusions
4C (convex portion) protruding outward in a radial direction are
provided so as to extend in the axial direction at an interval of
90.degree. in a circumferential direction, and in upper ends and
lower ends of the respective protrusions 4C, on end surfaces 4a, 4b
formed of planes orthogonal to the axis M, four upper-side fixing
pins 13A (first fixing pin portions) and lower-side fixing pins 13B
(first fixing pin portions), which respectively protrude upward and
downward along the axis M are provided, respectively.
[0056] The upper-side fixing pins 13A hold the upper plate spring
6, and the lower-side fixing pins 13B hold the lower plate spring
7.
[0057] Although the positions of the upper-side fixing pins 13A and
the lower-side fixing pins 13B in a planar view may be different
from each other, they are placed at coaxial positions parallel to
the axis M in this embodiment. Therefore, the upper-side fixing
pins 13A and the lower-side fixing pins 13B at the upper plate
spring 6 and the lower plate spring 7 have insertion positions in
common.
[0058] Further, although the respective center positions in the
radial direction of the upper-side fixing pins 13A and the
lower-side fixing pins 13B may be different, they are placed on the
same circumference in this embodiment. Therefore, the respective
center positions are placed in a tetragonal lattice shape.
[0059] On the outer side in the radial direction of the lens frame
4, a guide protrusion 4D (protrusion portion) is provided so as to
protrude outward in the radial direction from the lower end side of
one protrusion 4C. The protruding direction of the guide protrusion
4D is set at a positional relationship shifted by an angle .THETA.
(where .THETA. is an acute angle) from an integral multiple of
90.degree. from the angular position in the circumferential
direction of each upper-side fixing pin 13A and each lower-side
fixing pin 13B with respect to the axis M. More specifically, when
the guide protrusion 4D is placed along a diagonal line of a
square, each upper-side fixing pin 13A and each lower-side fixing
pin 13B are placed at a position shifted by a predetermined angle
.THETA. from a diagonal line of a square.
[0060] As illustrated in FIG. 3, the guide protrusions 4D locks the
SMA wire 10 to a tip end key portion 4D1 thereof, and the guide
protrusion 4D is lifted upward (direction indicated by the arrow
(Z1)) to be moved due to the contraction of the SMA wire 10.
[0061] Further, as illustrated in FIGS. 2, 6(a), and 6(b),
positioning portions 4E in protrusion shapes are provided so as to
extend in a circumferential direction from a side portion of each
protrusion 4C along a lower portion of the outer wall surface 4B of
the lens frame 4.
[0062] Each of the positioning portions 4E has a smooth positioning
surface 4E1 on an upper surface thereof, and the position in the
axial direction of the positioning surface 4E1 is set at a position
where positioning portion 4E abuts against a positioning reception
portion 5E of the module frame 5 described later (see FIG. 5(b))
when the lens frame 4 tries to move along the axis M upward
(direction indicated by the arrow (Z1)) by a distance equal to or
longer than a predetermined distance.
[0063] Further, in this embodiment, the lens frame 4 is molded
integrally with a thermoplastic resin capable of being caulked with
heat or ultrasonic wave, such as a polycarbonate (PC) or a liquid
crystal polymer (LCP) resin.
[0064] As illustrated in FIGS. 2, 7(a), and 7(b), the module frame
5 is a tubular member whose outer shape in a planar view is formed
in a substantially rectangular shape as a whole, and in which a
housing portion 5A formed of a through-hole is formed coaxially
with the axis M in the center portion thereof. The lens frame 4 is
housed in the housing portion 5A.
[0065] At upper and lower four corners of the module frame 5, there
are formed end surfaces 5a, 5b formed of planes orthogonal to the
axis M. Four upper-side fixing pins 14A (second fixing pin
portions) are provided upward from the end surfaces 5a, and four
lower-side fixing pins 14B (second fixing pin portions) are
provided downward from the end surfaces 5b.
[0066] The upper-side fixing pins 14A hold the upper plate spring
6, and the lower-side fixing pins 14B hold the lower plate spring
7, the module lower plate 8, and the feeding member 9.
[0067] The distance between the end surfaces 5a, 5b is set to the
same distance as that between the end surfaces 4a, 4b of the lens
frame 4.
[0068] In a lower portion at one corner of the module frame 5,
there is formed a cut-away portion 5B (protrusion inserting
portion) whose groove width in a planar view has a size that is
fitted with the guide protrusion 4D of the lens frame 4 so as to
move in the axial direction. The cut-away portion 5B allows the
guide protrusion 4D of the lens frame 4 to pass through while the
lens frame 4 is inserted to be housed in the module frame 5 from a
lower side, allows the tip end key portion 4D1 of the guide
protrusion 4D to protrude outward in the radial direction of the
module frame 5, and determines the position of the lens frame 4 in
the circumferential direction.
[0069] In this embodiment, the cut-away portion 5B is provided at
such a position, and hence, as illustrated in FIG. 7(b), the
lower-side fixing pin 14B in the vicinity of the cut-away portion
5B is formed at a position away from a line connecting the axis M
to an intersection of the corners of the outer shape avoiding the
cut-away portion 5B. More specifically, the lower-side fixing pin
14B is provided adjacent to the cut-away portion 5B in the
circumferential direction.
[0070] In contrast, the other three lower-side fixing pins 14B are
respectively provided on a line connecting the axis M to the
intersection of the corners of the outer shape, and are placed
forming an L-shape along the outer shape of the module frame 5.
Thus, four lower-side fixing pins 14B are placed at positions
asymmetrical to each other in a planar view.
[0071] Meanwhile, although the positions of the upper-side fixing
pins 14A and the lower-side fixing pins 14B in a planar view may be
different from each other, they are placed at coaxial positions
parallel to the axis M in this embodiment, respectively. Therefore,
the upper-side fixing pins 14A and the lower-side fixing pins 14B
at the upper plate spring 6 and the lower plate spring 7 have
insertion positions in common.
[0072] As illustrated in FIG. 7(b), assuming that intersections on
side surfaces of the module frame 5 are indicated by Q1, Q2, Q3,
and Q4 in a planar view, the axis center of each upper-side fixing
pin 14A and each lower-side fixing pin 14B are placed respectively
in the vicinity of the points Q1, Q2, Q3, and Q4, and on or in the
vicinity of line segments K1, K2, K3, and K4 connecting the points
Q1, Q2, Q3, Q4 to the axis M. More specifically, the line segments
k1, k2, k3, and k4 connecting the axis center of each upper-side
fixing pin 14A and each lower-side fixing pin 14B to the axis M
overlap the line segments K1, K2, K3, and K4, or cross them at a
small angle of about 30.degree. or less.
[0073] As illustrated in FIG. 7(a), at two corners adjacent to the
cut-away portion 5B of the module frame 5, there is provided a pair
of locking grooves 5C for attaching the wire holding members 15A,
15B for holding the SMA wire 10 (see FIGS. 2 and 3) on a side
surface on the side in the same direction as that of the corner at
which the cut-away portion 5B. In this embodiment, the wire holding
member 15A is provided on a side surface on the side from which a
pair of terminal portions 9C of the feeding member 9 protrude from
the driving module 1, and the wire holding member 15B is provided
on a side surface on the side from which a pair of terminal
portions 9C of the feeding member 9 do not protrude from the
driving module 1.
[0074] The wire holding members 15A, 15B are conductive members
made of a metal plate or the like formed in a key shape, obtained
by caulking the ends of the SMA wire 10 onto the ends of the wire
holding members 15A, 15B, and the wire holding members 15A, 15B are
fitted in the locking grooves 5C from the side, thereby holding the
ends of the SMA wire 10 while positioning the SMA wire 10.
[0075] The wire holding members 15A, 15B have chip-shaped terminal
portions 15a on a side opposite to the caulking position of the SMA
wire 10, as illustrated in FIG. 3, and under the attached state
with respect to the module frame 5, the terminal portions 15a are
allowed to protrude slightly downward from the module lower plate 8
stacked on the lower side of the module frame 5.
[0076] Further, the SMA wire 10 whose both ends are held by a pair
of wire holding members 15A, 15B is locked from a lower side to the
tip end key portion 4D1 of the guide protrusion 4D of the lens
frame 4 protruding from the cut-away portion 5B of the module
frame, and biases the lens frame 4 upward via the tip end key
portion 4D1 due to the tension of the SMA wire.
[0077] In the housing portion 5A of the module frame 5, as
illustrated in FIGS. 7(a), 7(b), the positioning reception portion
5E that is a concave formed from the inner wall surface 5D to the
outer side in the radial direction and extending from the lower end
side to the intermediate portion on the upper end side in the axial
direction is formed in such a shape as to allow each positioning
portion 4E of the lens frame 4 to be inserted from a lower
side.
[0078] The positioning reception portion 5E has a receiving surface
5E1 capable of allowing the positioning surface 4E1 of the
positioning portion 4E to abut against the positioning reception
portion on a lower side in the axial direction. Thus, as
illustrated in FIG. 5 (b), when the lens frame 4 moves upward
(direction indicated by an arrow (Z1)) along the axis M by a
predetermined distance, the receiving surface 5E1 of each
positioning reception portion 5E abuts against the positioning
surface 4E1 of each positioning portion 4E. Therefore, the upward
movement of the lens frame 4 is regulated. More specifically, the
positioning reception portion 5E constitutes a position regulating
portion that regulates the movement range of the lens frame 4, and
the positioning portion 4E constitutes a portion whose position is
to be regulated, provided so as to abut against the position
regulating portion of the module frame 5.
[0079] In this embodiment, the position in a planar view where the
positioning reception portion 5E is formed is provided at positions
crossing the line segments K1, K2, K3, and K4 directed from the
center (axis M) of the housing portion 5A to the corners of the
rectangular outer shape of the module frame 5, as illustrated in
FIG. 7(b).
[0080] Due to such a configuration, even when large shock is
applied to the driving module from outside, for example, the
driving module is dropped, the lens frame 4 cannot move upward in
the figure, exceeding the position of the receiving surface 5E1 of
the positioning reception portion 5E1.
[0081] In this embodiment, such a regulating position is set in
such a manner that the lens frame 4 does not bump against the cover
11, and the deformation of the upper plate spring 6 and the lower
plate spring 7 is equal to or less than, for example, a deformation
limit such as an elastic limit.
[0082] The positioning reception portions 5E are provided at
positions crossing the line segments K1, K2, K3, and K4 directed
from the center of the housing portion 5A to the corners of the
rectangular outer shape of the module frame 5, and hence a region
in a radial direction can be effectively used in the corners of the
rectangular outer shape protruding from the housing portion 5A to
the outer side in the radial direction in the module frame 5.
[0083] Therefore, even if the positioning reception portions 5E are
provided on an inner side of the module frame 5, the outer shape of
the module frame 5 can be prevented from being increased, which
enables miniaturization and reduction in weight.
[0084] Further, in this embodiment, the module frame 5 is
integrally molded with a thermoplastic resin capable of being
caulked with heat or an ultrasonic wave, such as a polycarbonate
(PC) or a liquid crystal polymer (LCP) resin in the same way as in
the lens frame 4.
[0085] On each upper portion and each lower portion of the module
frame 5 and the lens frame 4 inserted therein, as illustrated in
FIG. 4, the upper plate spring 6 and the lower plate spring 7 are
stacked respectively.
[0086] In this embodiment, as illustrated in FIG. 8, the upper
plate spring 6 and the lower plate spring 7 are plate spring
members in a plate shape punched into the same shape, and are
formed of, for example, a metal plate having a spring property such
as stainless (SUS) steel plate.
[0087] As illustrated in FIG. 8, the outer shape in a planar view
of the upper spring 6 (lower spring 7) is a substantially
rectangular shape similar to that of an end on an upper side (lower
side) of the module frame 5, and a circular opening 6C (7C) that is
slightly larger than the inner circumferential surface 4F of the
lens frame 4 and is coaxial with the axis M is formed at the
center, whereby the upper plate spring 6 (lower plate spring 7) is
formed in a ring shape as a whole.
[0088] At three corners and in the vicinity of one corner of the
upper plate spring 6 (lower plate spring 7), four through-holes 6B
(7B) in which the upper-side fixing pins 14A (lower-side fixing
pins 14B) can be inserted respectively are provided correspondingly
to the arrangement positions of the upper-side fixing pins 14A
(lower-side fixing pins 14B) formed at the corners and in the
vicinity of one corner of the module frame 5. In this embodiment,
of the through-holes 6B (7B) in which the upper-side fixing pins
14A (lower-side fixing pins 14B) formed at the corners
corresponding to the points Q2, Q4 are inserted in FIG. 7(b), one
is formed in a standard circular hole and the other is formed in an
oval hole, which enables the positioning in a plane orthogonal to
the axis M with respect to the module frame 5.
[0089] Further, on the upper plate spring 6 (lower plate spring 7),
four through-holes 6A (7A) in which the upper-side fixing pins 13A
(lower-side fixing pins 13B) can be inserted respectively are
provided correspondingly to the arrangement position of the
upper-side fixing pins 13A (lower-side fixing pins 13B) formed on
the lens frame 4.
[0090] More specifically, in this embodiment, each through-hole 6A
(7A) is formed at a position shifted by an angle .theta. from an
integral multiple of 90.degree. with respect to a straight line L1
corresponding to the line segment K1 in FIG. 7(b).
[0091] In this embodiment, by setting the angle .theta. to be an
appropriate value in such an arrangement, the respective
arrangement positions of the through-hole 6A (7A) and the
through-hole 6B (7B) can be set in such a manner that the
difference between the diameter of a circle with respect to the
axis M at which the through-hole 6A (7A) is positioned and the
diameter of a circle with respect to the axis Mat which the
through-hole 6B (7B) is positioned becomes smaller than that in the
case where the through-hole 6A (7A) and the through-hole 6B (7B)
are placed so that the angle .theta. becomes 0.degree..
[0092] Further, a ring portion 6F (7F) is formed on an outer side
in a radial direction of the opening 6C (7C), and four slits 6D
(7D) extending in a substantially semi-arc shape in a
circumferential direction from positions in the vicinity of the
through-holes 6A (7A) opposed to each other in a diagonal direction
with the axis M interposed therebetween are formed in a state where
they overlap each other in a radial direction by a substantially
quadrant arc.
[0093] Thus, a plate spring member is formed in which four spring
portions 6E (7E) extending in a substantially quadrant arc shape
from the rectangular frame on the outer side of the upper plate
spring 6 (lower plate spring 7) extend to the vicinity of the
through-holes 6A (7A) one by one.
[0094] As described above, in this embodiment, the outer shape of
the upper plate spring 6 (lower plate spring 7) is provided in a
rectangular shape substantially matched with the outer shape of the
module frame 5, and the spring portion 6E (7E) and the ring portion
6F (7F) are formed in a ring-shaped region along the opening 6C
(7C). Then, the through-holes 6B (7B) that are portions to be fixed
are provided at corners with a space in accordance with the
arrangement of the upper-side fixing pins 14A (lower-side fixing
pins 14B) for fixing the upper plate spring 6 (lower plate spring
7) to the module frame 5, and hence, the shape of the through-hole
6B (7B) can be away from the spring portion 6E (7E). Therefore,
production by precise punching and production by etching can be
performed easily.
[0095] As illustrated in FIG. 2, the module lower plate 8 is used
for stacking the lower plate spring 7 by sandwiching the lower
plate spring 7 between the module lower plate 8 and the module
frame 5 from the lower side while the respective lower-side fixing
pins 14B of the module frame 5 are inserted in the through-holes 7B
of the lower plate spring 7 and the respective lower-side fixing
pins 13B of the lens frame 4 housed in the module frame 5 are
inserted in the through-holes 7A of the lower plate spring 7, and
fixing the outer frame in a rectangular shape of the lower plate
spring 7 to the end surface 5b of the module frame 5 in a pressed
state.
[0096] As illustrated in FIGS. 9(a) and 10, the module lower plate
8 is a plate member having a rectangular outer shape substantially
similar to the outer shape of the module frame 5, and an opening 8A
in a substantially circular shape with respect to the axis M is
formed through the center portion of the module lower plate 8 in
the thickness direction. Then, at a time of assembly, four U-shaped
concave portions 8B for avoiding the interference with a caulking
portion described later are formed at positions corresponding to
the arrangement positions of the respective lower-side fixing pins
13B of the lens frame 4 on the upper surface 8a side to be stacked
on the lower plate spring 7.
[0097] Further, at the respective corners positioned at a
circumferential edge of the module lower plate 8, through-holes 8C
allowing the lower-side fixing pins 14B to be inserted therethrough
are formed correspondingly to the arrangement positions of the
respective lower-side fixing pins 14B of the module frame 5.
[0098] Further, as illustrated in FIGS. 9(b) and 10, a wall portion
8D protruding downward along the opening 8A is formed on a lower
surface 8b of the module lower plate 8. In this embodiment, the
distance between the upper surface 8a and the lower surface 8b is
set at h1, and the distance between the upper surface 8a and the
end surface 8c of the wall portion 8D is set at h2 (where
h1<h2). The end surface 8c of the wall portion 8D constitutes an
attachment surface to be brought into contact with the substrate 2.
Herein, the distance h2 is set to be such a height as to protrude
downward from a caulking portion when the feeding member 9 is
caulked to the lower surface 8b.
[0099] Further, the wall portion 8D has a function of a positioning
spacer that performs positioning in the axis M direction, i.e., in
the optical axis direction with respect to the substrate 2 by
setting the distance h2 appropriately.
[0100] In this embodiment, as the material for the module lower
plate 8, a synthetic resin having an electric insulating property
and a light-shielding property is adopted.
[0101] Therefore, as illustrated in FIG. 5 (a), the wall portion 8D
has a function of a light-shielding material that shields the
periphery of the image pickup element 30 from light by covering the
image pickup element 30 provided on the substrate 2 from a
side.
[0102] Further, due to the electric insulating property, the module
lower plate 8 functions as an insulating member that fixes the
feeding member 9 to the lower plate spring 7 in an electrically
insulated state. Further, the module lower plate 8 also functions
as an insulating member that keeps an electrically insulated state
with respect to the substrate 2 which the end surface 8c abuts
against.
[0103] As illustrated in FIG. 11, the feeding member 9 includes a
pair of electrodes 9a, 9b respectively made of a plate-shaped metal
plate in this embodiment.
[0104] The electrodes 9a, 9b are formed of a bent line shaped metal
plate having a wiring portion 9B in a substantially L-shape along
the outer shape of the module lower plate 8 and terminal portions
9C protruding to the outer side of the outer shape of the module
lower plate 8 from the end of the wiring portion. Each wiring
portion 9B is provided with two through-holes 9A for positioning
the electrodes 9a, 9b with respect to the module frame 5 by
inserting two lower-side fixing pins 14B adjacent to each other
along the outer shape of the module lower plate 8 of the lower-side
fixing pins 14B of the module frame 5 protruding downward from the
lower surface 8b of the module lower plate 8.
[0105] In this embodiment, as illustrated in FIG. 3, the terminal
portions 9C of the electrodes 9a, 9b are provided in the module
frame 5 so as to protrude in parallel outward in the radial
direction from the side surface on which the wire holding member
15A is attached.
[0106] Therefore, the electrode 9a is provided with a conductive
connecting portion 9D that is cut away in a concave shape so as to
electrically connect the terminal portions 15a of the wire holding
member 15A to the side surface on the wiring portions 9B between
the through-holes 9A and the terminal portions 9C.
[0107] Further, the electrode 9b is provided with a conductive
connecting portion 9D that is cut away in a concave shape so as to
electrically connect the terminal portions 15a of the wire holding
member 15B to the side surface on the wiring portions 9B between
two through-holes 9A.
[0108] As means for electrically connecting the respective
conductive connecting portions 9D to the terminal portions 15a, for
example, adhesion through soldering or a conductive adhesive can be
adopted.
[0109] As illustrated in FIGS. 2, 4, and 12, the cover 11 is a
member in which a side wall portion 11D covering the module frame 5
from an outside of the module frame extends downward from an outer
edge of an upper surface 11E, an opening 11C in a rectangular shape
is formed on a lower side, and a circular opening 11A with the axis
M being the center is provided at the center of the upper surface
11E. The size of the opening 11A is designed so that the lens unit
12 can be taken in or out.
[0110] Further, as illustrated in FIG. 12, four U-shaped concave
portions 11B (run-off) for avoiding the interference with the
caulking portion 16 described later are formed at the positions
corresponding to the arrangement positions of the respective
upper-side fixing pins 13A of the lens frame 4 in the
circumferential direction of the opening 11A on the back surface
side of the upper surface 11E.
[0111] The depth of the concave portion 11B is set so that the
caulking portion 16 and the cover 11 do not come into contact with
each other even at a position where the positioning surface 4E1 and
the reception surface 5E1 abut against each other. The concave
portion 11B may be concave portion protruding upward. However, in
this embodiment, the thickness of the concave portion 11B is set to
be small, and the concave portion 11B is formed within the range of
the thickness of the cover 11, whereby the outer surface of the
upper surface 11E is set to be a flat surface.
[0112] The method of assembling the driving module 1 with such a
configuration is described successively. In a first step, first,
the lens frame 4 is inserted in the housing portion 5A of the
module frame 5 from a lower side, whereby each end surface 5a of
the module frame 5 and the end surface 4a of the lens frame 4 are
aligned to the same height. Then, the upper-side fixing pins 14A of
the module frame 5 and the upper-side fixing pins 13A of the lens
frame 4 are inserted in the respective through-holes 6A, 6B of the
upper plate spring 6.
[0113] After that, the tip ends of the upper-side fixing pins 14A,
13A that protrude upward through the through-holes 6A, 6B of the
upper plate spring 6 are caulked with heat by a heater chip (not
shown), whereby the caulking portion 16 which is a first fixing
portion and the caulking portion 17 which is a second fixing
portion are formed (see FIGS. 3 and 4).
[0114] At this time, the end surface 4a of the lens frame 4 and the
end surfaces 5a of the module frame 5 are aligned to the same
plane. The flat-plate-shaped upper plate spring 6 can be placed
without being deformed, and caulking with heat can be performed.
Therefore, it is not necessary to press the upper plate spring 6 to
be deformed, which makes it easy to perform caulking. Further, the
floating caused by the deformation of the upper plate spring 6 can
be prevented.
[0115] Further, the height of each heater chip can be set to be the
same, and hence, the variation in caulking precision can be reduced
even when the caulking portions 16, 17 are formed
simultaneously.
[0116] Next, in a second step, the lower-side fixing pins 13B of
the lens frame 4 are inserted respectively in the through-holes 7A
of the lower plate spring 7. At this time, the lower-side fixing
pins 14B of the module frame 5 are simultaneously inserted in the
through-holes 7B of the lower plate spring 7, the through-holes 8C
of the module lower plate 8, and the through-holes 9A of the
feeding member 9. After that, the tip ends of the lower-side fixing
pins 13B that protrude downward through the through-holes 7A of the
lower plate spring 7 are caulked with heat by a heater chip,
whereby caulking portions 18 which are first fixing portions (see
FIG. 4) are formed.
[0117] At this time, an axial distance between the end surfaces 4a,
4b of the lens frame 4 and an axial distance between the end
surfaces 5a, 5b of the module frame 5 are equal, and hence the end
surfaces 4b, 5b are aligned to the same plane. The
flat-plate-shaped lower plate spring 7 can be stacked and placed on
the module lower plate 8 without being deformed, and caulking with
heat can be performed. Therefore, the floating caused by the
deformation of the lower plate spring 7 can be prevented. Further,
the height of each heater chip can be set to be the same, and
hence, the variation in caulking precision can be reduced even when
the caulking portions 18 are formed simultaneously.
[0118] Next, in a third step, the lower ends of the lower-side
fixing pins 14B that protrude downward through the through-holes
7B, 8C, and 9A are caulked with heat by a heater chip, whereby
caulking portions 19 which are second fixing portions (see FIG. 4)
are formed.
[0119] At the time, the height of each heater chip can be set to be
the same, and hence, the variation in caulking precision can be
reduced even when the caulking portions 19 are formed
simultaneously.
[0120] Further, the concave portions 8B are formed in the module
lower plate 8, and hence the caulking portions 18 formed in the
second step do not come into contact with the module lower plate
8.
[0121] By performing the operations in the first to third steps,
the upper plate spring 6, the lower plate spring 7, the module
lower plate 8, and the feeding member 9 are stacked and fixed to
both ends of the lens frame 4 and the module frame 5.
[0122] In this embodiment, the upper-side fixing pins 13A and the
lower-side fixing pins 13B, and the upper-side fixing pins 14A and
the lower-side fixing pins 14B are provided respectively coaxially,
and hence, in the caulking in the first to third steps, the
positions on a plane of the heater chips for forming the caulking
portions 16, 18 and the caulking portions 17, 19 become common,
respectively. Therefore, it is not necessary to change the position
of a heater chip in each caulking, which enables a caulking
operation to be performed efficiently.
[0123] By caulking the plate spring member with heat as described
above, the plate spring member can be sandwiched and fixed between
the support and the body to be driven by the caulking portions.
Thus, a period of time required for hardening is shorter compared
with the case of fixing by adhesion or the like, and hence, an
assembly time can be reduced. Further, there is no fear that
components are contaminated due to the generation of gas. Further,
sequentially stable fixing can be performed. Consequently, the
reliability of a fixed portion can be enhanced.
[0124] Further, a simple configuration with the number of
components reduced is achieved because fixing components such as
screws are not used, which enables more reduction in weight and
miniaturization. In particular, the lens frame 4 that is a body to
be driven is reduced in weight, and hence the driving at high speed
with low power consumption can be performed.
[0125] Next, in a fourth step, a pair of wire holding members 15A,
15B provided with the SMA wire 10 attached to tip ends thereof are
locked respectively with locking grooves 5C at two places of the
module frame 5, whereby the wire holding members 15A, 15B are held
and fixed to the module frame 5 by means such as fitting or
adhesion. At this time, the center of the SMA wire 10 is locked
with the tip end key portion 4D1 of the guide protrusion 4D and
placed across so as to support the tip end key portion 4D1 from a
lower side.
[0126] At this time, the terminal portions 15a of the wire holding
members 15A, 15B protrude to a lower side of the module lower plate
8 and are respectively locked with the conductive connecting
portions 9D of the electrodes 9a, 9b that are the feeding member 9
fixed to the module lower plate 8, or placed in the vicinity
thereof.
[0127] The terminal portions 15a are electrically connected to the
conductive connecting portions 9D using, for example, soldering or
a conductive adhesive.
[0128] Next, in a fifth step, the cover 11 is placed on the module
frame 5 from above, thereby connecting the side wall portion 11D to
the module lower plate 8. For example, an engagement hook or the
like is provided at the side wall portion 11D, and the side wall
portion 11D is connected to the module lower plate 8 by fitting.
Alternatively, the side wall portion 11D and the module lower plate
8 are connected to each other by adhesion or welding.
[0129] At this time, the caulking portions 16, 17 are respectively
away from the back surface of the upper surface 11E of the cover
11.
[0130] The assembly of a main body of the driving module 1 is
completed.
[0131] Next, in a sixth step, the driving module 1 is attached to
the substrate 2 with the terminal portions 9C of the driving module
1 being positioned with respect to the land portions 3 on the
substrate 2 (see FIG. 1). Then, the terminal portions 9C are
electrically connected to the land portions 3 by means such as
soldering or a conductive adhesive. At this time, the caulking
portions 19 have a height lower than that of the wall portion 8D of
the module lower plate 8, and hence, is away from the substrate
2.
[0132] As the attachment of the driving module 1 to the substrate
2, fixing means such as adhesion and fitting can be adopted.
[0133] The substrate 2 may be an independent member belonging to
the driving module 1, or a member connected to and placed at an
electronic apparatus or the like.
[0134] Next, in a seventh step, the lens unit 12 is screwed and
fixed in the lens frame 4 through the opening 11A of the cover
11.
[0135] The reason why the lens unit 12 is attached finally is to
prevent the lens of the lens unit 12 from being contaminated or to
prevent dust and the like from adhering to the lens during an
assembly operation. For example, in the case where the driving
module 1 is shipped in a product state with the lens unit 12
attached thereto, and the case where the opening 11A of the cover
11 is desired to be smaller than the outer shape of the lens unit
12, for example, the opening 11A is also used as a diaphragm, the
seventh step may be performed in the middle of the fifth step or
the sixth step.
[0136] Next, the operation of the driving module 1 is
described.
[0137] In a state of the driving module 1 in which power is not
supplied to the terminal portions 9C, the forces acting on the lens
frame 4, such as the tension from the SMA wire 10 and the biasing
force that elastically biases the caulking portions 16, 18 from the
upper plate spring 6 and the lower plate spring 7, are balanced,
and as illustrated in FIG. 5(a), the lens frame 4 with the lens
unit 12 attached thereto is held at a constant position in the
axial direction.
[0138] When power is supplied from the terminal portions 9C to the
feeding member 9, for example, the electrodes 9a, the wire holding
member 15A, the SMA wire 10, the wire holding portion 15b, and the
electrodes 9b are brought into conduction, and hence, a current
flows through the SMA wire 10. When Joule heat is generated in the
SMA wire 10 and the temperature of the SMA wire 10 is raised to
exceed the transformation start temperature of the SMA wire 10, the
SMA wire contracts to the length in accordance with the
temperature.
[0139] Consequently, the guide protrusion 4D of the lens frame 4
moves upward ((Z1) direction in the figure). Thus, the upper plate
spring 6 and the lower plate spring 7 are respectively deformed,
and an elastic recovery force in accordance with the deformed
amount biases the lens frame 4. Then, the lens frame 4 stops at a
position where the elastic recovery force and the tension of the
SMA wire 10 are balanced.
[0140] At this time, in this embodiment, the upper plate spring 6
and the lower plate spring 7 constitute parallel springs, and
hence, the lens frame 4 is moved along the axis M precisely even
without being placed along the guide member in the axial direction.
Therefore, it is possible to reduce the number of components, and
to achieve miniaturization. Further, a sliding burden with respect
to the guide member does not occur, and hence, lower power
consumption can be realized.
[0141] Further, when the supply of power is stopped, the SMA wire
10 can expand, and the lens frame 4 moves to a balanced position in
a lower portion ((Z2) direction in the figure).
[0142] Thus, the lens frame 4 can be driven in the direction of the
axis M by controlling the supply amount of power.
[0143] Further, in the case where the SMA 10 contracts excessively
to increase the movement amount of the lens frame 4 excessively at
a time of some abnormality, for example, at a time of receiving
impact force from dropping or instability of power control, due to
the presence of the positioning portion 4E and the positioning
reception portion 5E in this embodiment, the position of the lens
frame 4 is regulated to a predetermined limit value. Therefore, the
lens frame 4 can be prevented from bumping against the cover 11,
and the upper plate spring 6 and the lower plate spring 7 can be
prevented from being deformed beyond a deformation limit. Thus,
reliability can be enhanced.
[0144] According to the driving module 1 in this embodiment, the
positions in the radial direction of the caulking portions 16, 18
and the caulking portions 17, 19, which fix the upper-side fixing
pins 13A, the lower-side fixing pins 13B, the upper-side fixing
pins 14A, and the lower-side fixing pins 14B to the lens frame 4
and the module frame 5 by sandwiching them, can be close to each
other. Therefore, the risks of breakage and failures due to impact
force caused by dropping or the like can be reduced, and the
miniaturization can be achieved.
[0145] Next, modifications of this embodiment are described.
[0146] FIG. 13 is a schematic cross-sectional view illustrating a
configuration of a driving module according to a modification of
Embodiment 1 of the present invention. In order to illustrate a
cross-section including screws 42, 52 described later, the
cross-section taken along a bent cross-sectional line similar to
the line A-A in FIG. 3 is illustrated.
[0147] As illustrated in FIG. 13, the driving module 1A of the
modification includes voice coil type driving means using the
driving coil 41 and the magnet 50 in place of the driving means
using the SMA wire 10 of Embodiment 1, and the screws 42 (first
fixing portions) and the screws 52 (second fixing potions) in place
of the caulking portions 16, 18 and the caulking portions 17,
19.
[0148] Hereinafter, the difference from Embodiment 1 is mainly
described.
[0149] The driving coil 41 is provided in an outer circumferential
portion of the cylindrical lens frame 40 (body to be driven) with
the lens unit 12 screwed in the inner circumferential side.
[0150] On an end surface in the axial direction of the lens frame
40, female screw portions 40a allowing the screws 42 to be screwed
therewith are provided at the positions similar to those of the
upper-side fixing pins 13A and the lower-side fixing pins 13B in
Embodiment 1.
[0151] The magnet 50 is formed in a cylindrical shape accommodating
the lens frame 40 in an inner circumferential portion, and plate
spring attachment portions 51 are respectively fixed to the
cylinder end portions. In the plate spring attachment portions 51,
female screw portions 51a allowing screws 52 to be screwed
therewith are provided at the positions similar to those of the
upper-side fixing pins 14A and the lower-side fixing pins 14B of
Embodiment 1. The magnet 50 with the plate spring attachment
portions 51 fixed thereto constitutes a cylindrical support
accommodating the body to be driven inside.
[0152] Each of the lower-side plate spring attachment portions 51
is fixed to the module lower plate 8 provided below through
appropriate means such as screwing or adhesion in the
circumferential direction (not shown).
[0153] Further, the upper plate spring 6 and the lower plate spring
7 are fixed to the lens frame 40 and the plate spring attachment
portions 51 to be sandwiched between them and the screws 42,
52.
[0154] According to the driving module 1A having the
above-mentioned configuration, similarly to the driving module 1
according to Embodiment 1, the positions in the radial direction of
the screws 42 and the screws 52 placed close to each other.
Therefore, the risks of breakage and failures due to impact force
caused by dropping or the like can be reduced, and the
miniaturization can be achieved.
Embodiment 2
[0155] Next, an electronic apparatus according to Embodiment 2 of
the present invention is described.
[0156] FIGS. 14(a) and 14(b) are external perspective views of a
front surface and a back surface of an electronic apparatus
according to Embodiment 2 of the present invention. FIG. 14(c) is a
cross-sectional view taken along the line F-F of FIG. 14(b).
[0157] A mobile phone 20 with a camera in this embodiment
illustrated in FIGS. 14(a) and 14(b) is an example of an electronic
apparatus having the driving module 1 according to Embodiment 1 and
further the driving module 1A according to the modification.
[0158] The mobile phone 20 with a camera includes well-known
apparatus configurations of a mobile phone such as a receiving
portion 22a, a sending portion 22b, an operation portion 22c, a
liquid crystal display portion 22d, an antenna portion 22e, and a
control circuit portion (not shown) inside and outside of covers
22.
[0159] Then, as illustrated in FIG. 14(b), a window 22A
transmitting ambient light is provided in the cover 22 on a back
surface of the side on which the liquid crystal display portion 22d
is provided. As illustrated in FIG. 14(c), the driving module 1
(1A) of Embodiment 1 is set so that the opening 11A of the driving
module 1 (1A) faces the window 22A of the cover 22, and the axis M
is placed along the normal direction of the window 22A.
[0160] Then, the driving module 1 is mechanically and electrically
connected to the substrate 2.
[0161] The substrate 2 is connected to the control circuit portion
(not shown) so as to supply power to the driving module 1.
[0162] According to such a configuration, light transmitted through
the window 22A is collected at the lens unit 12 (not shown) of the
driving module 1 (1A) and can form an image on the image pickup
element 30. Then, power is supplied appropriately from the control
circuit portion to the driving module 1, whereby a focus position
is adjusted by driving the lens unit 12 in the direction of the
axis M to perform photographing.
[0163] Due to the presence of the driving module 1 (1A) of
Embodiment 1, the mobile phone 20 with a camera can be miniaturized
and produced easily, and hence, high reliability can be ensured
even in the case of dropping the mobile phone 20.
[0164] In the above description, the case of using an SMA wire for
the driving means, and the case of using the voice coil type
driving means utilizing the driving coil and the magnet are
described. However, the driving means is not limited thereto as
long as it drives the body to be driven in a predetermined
direction with respect to the support. For example, driving means
such as a linear motor can be adopted.
[0165] Further, the description of Embodiment 1, the case is
described in which the upper-side fixing pins 13A, 14A, and the
lower-side fixing pins 13B, 14B are inserted in the upper plate
spring 6 and the lower plate spring 7 that are plate spring members
for biasing the support, and tip ends of the fixing pins are
caulked with heat. However, the method of fixing the plate spring
members is not limited thereto. For example, the plate spring
members may be fixed by ultrasonic caulking, or the plate spring
member may be adhered to the body to be driven or the support.
According to the present structure, a large adhesion area can be
ensured, and hence, large strength can be obtained even using an
adhesive.
[0166] Further, in the above description, the module frame 5 is a
member generally formed into a substantially rectangular shape.
However, the module frame 5 may have a polygonal shape without
being limited to a substantially rectangular shape. In this case, a
rectangular corner can be replaced by a polygonal corner.
[0167] Further, in the above description, the case where the
driving module is used in a focus position adjusting mechanism of a
lens unit is exemplified. However, the use of the driving module is
not limited thereto. For example, the driving module may be used in
another portion as an appropriate actuator that moves a body to be
driven to a target position. For example, the driving module can be
used as an appropriate actuator by screwing a rod member or the
like in place of the lens unit 12 or changing the lens frame 4 to
another shape. More specifically, the body to be driven may include
a columnar member without being limited to a tubular member.
[0168] Further, in the above description, the electronic apparatus
using the driving module is described in an example of a mobile
phone with a camera. However, the kind of the electronic apparatus
is not limited thereto. For example, the driving module may be used
in an optical apparatus such as a digital camera or a camera built
in a personal computer, or used as an actuator that moves a body to
be driven to a target position in an electronic apparatus such as
an information reading storage device and a printer.
[0169] Further, the components in each embodiment described above
may be combined appropriately within the technical concept of the
present invention, if possible technically.
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