U.S. patent application number 13/216251 was filed with the patent office on 2012-12-06 for voice coil motor and related image capturing module.
This patent application is currently assigned to HON HAI PRECISION INDUSTRY CO., LTD.. Invention is credited to CHAU-YUAN KE, YU-BIN WANG.
Application Number | 20120307140 13/216251 |
Document ID | / |
Family ID | 47190892 |
Filed Date | 2012-12-06 |
United States Patent
Application |
20120307140 |
Kind Code |
A1 |
WANG; YU-BIN ; et
al. |
December 6, 2012 |
VOICE COIL MOTOR AND RELATED IMAGE CAPTURING MODULE
Abstract
A voice coil motor includes a movable receiving cylinder having
protrusions formed at an end; a wire coil surrounding the receiving
cylinder; a hollow fixing frame receiving the receiving cylinder
and the wire coil; magnetic members fixedly received in the fixing
frame, top and bottom elastic members. The top elastic member
includes a peripheral portion and a resilient central portion, the
central portion having a central opening and cutouts. The
protrusions of the receiving cylinder are engaged in the cutouts.
The peripheral portion is fixed at a lower position than the
central portion, thereby forming an elastic force applied to the
receiving cylinder when no current is applied to the wire coil. The
bottom elastic member is connected to the receiving cylinder and
the fixing frame, and is in an undeformed state when no current is
applied to the wire coil.
Inventors: |
WANG; YU-BIN; (Tu-Cheng,
TW) ; KE; CHAU-YUAN; (Tu-Cheng, TW) |
Assignee: |
HON HAI PRECISION INDUSTRY CO.,
LTD.
Tu-Cheng
TW
|
Family ID: |
47190892 |
Appl. No.: |
13/216251 |
Filed: |
August 24, 2011 |
Current U.S.
Class: |
348/374 ;
310/12.16 |
Current CPC
Class: |
G02B 7/08 20130101; H02K
41/0356 20130101; H04N 5/2257 20130101 |
Class at
Publication: |
348/374 ;
310/12.16 |
International
Class: |
H04N 5/225 20060101
H04N005/225; H02K 41/035 20060101 H02K041/035 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 3, 2011 |
TW |
100119618 |
Claims
1. A voice coil motor, comprising: a movable receiving cylinder
having an inner receiving space for receiving a lens module, the
receiving cylinder comprising a first end and an opposite second
end, the first end adjacent to an object side of the lens module
and the second end adjacent to an image side of the lens module;
the receiving cylinder comprising a plurality of protrusions formed
at the first end; a wire coil fixed to the receiving cylinder and
surrounding the receiving cylinder; a hollow fixing frame receiving
the receiving cylinder and the wire coil; a group of magnetic
members fixed to an inner wall of the fixing frame and surrounding
the wire coil, the magnetic members and the wire coil cooperatively
configured for generating a magnetic driving force for driving the
receiving cylinder to move in the fixing frame; a top elastic
member comprising a peripheral portion and a central portion
resiliently connected to the peripheral portion, the central
portion having a central opening and a plurality of cutouts formed
in an inner edge thereof in the central opening, the protrusions of
the receiving cylinder engaged in the cutouts, the peripheral
portion being fixed at a position lower than the central portion,
thereby forming an elastic force applied to the receiving cylinder
in a direction from the first end to the second end when no current
is applied to the wire coil; and a bottom elastic member connected
to the receiving cylinder and the fixing frame, the bottom elastic
member being in an undeformed state when no current is applied to
the wire coil.
2. The voice coil motor of claim 1, wherein the receiving cylinder
further comprises a rim, a plurality of ribs are formed at an outer
wall of the rim of the receiving cylinder, the rim extending
outwards from the outer wall along a circumferential direction of
the receiving cylinder, the ribs extending upwards from the rim
along a central axis direction of the receiving cylinder, the wire
coil fixed on the rim, the ribs configured for creating a first
space between the wire coil and the outer wall of the receiving
cylinder.
3. The voice coil motor of claim 2, wherein the fixing frame
comprises a base, a frame and a cover, the frame has a top panel
having an opening, and a plurality of tabs depending from an inner
wall of the top panel in the opening along a central axis direction
of the frame, a second space is formed between the inner wall of
the frame and each of the tabs, each of the tabs extending into the
first space, and the magnetic members being received in the
respective second space.
4. The voice coil motor of claim 1, further comprising a
ring-shaped clamping member for clamping the peripheral portion of
top elastic member, a height of each of the magnetic members is
less than a height of the receiving cylinder, the clamping member
clamping the peripheral portion of the top elastic member on the
magnetic members.
5. The voice coil motor of claim 1, wherein the top elastic member
has a plurality of slots formed between the peripheral portion and
the central portion.
6. The voice coil motor of claim 1, wherein the receiving cylinder
has an inner thread formed in the inner wall of the inner space
threadedly engaging with the lens module.
7. An image capturing module, comprising: a voice coil motor of
claim 1; and a lens module received in the inner space of the
receiving cylinder of the voice coil motor.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present disclosure relates to a voice coil motor and an
image capturing module using same.
[0003] 2. Description of Related Art
[0004] Voice coil motors (VCMs) are widely used as lens actuators
in electronic devices having an image capturing function. A typical
VCM includes a movable receiving cylinder for receiving a lens
module, a group of magnetic members in cooperation with a wire coil
for generating a driving force, a fixing frame and one or more
elastic members connecting the movable receiving cylinder to the
fixing frame.
[0005] Usually, no matter how many elastic members are used, the
elastic members are all in an undeformed state, or all at a
deformed state when the VCM is not initiated. However, if the one
or more elastic members are all at an undeformed state, the movable
receiving cylinder together with the lens module may be shaken if
the entire module is taken downwards; and if the elastic members
are all at a deformed state, the movable receiving cylinder may
need to bear additional pressure, and the molding of the receiving
cylinder will require a higher precision.
[0006] What is needed, therefore, is a voice coil motor and an
image capturing module using same, which can overcome the above
shortcomings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Many aspects of the present voice coil motor and image
capturing module can be better understood with reference to the
following drawings. The components in the drawings are not
necessarily drawn to scale, the emphasis instead being placed upon
clearly illustrating the principles of the present voice coil motor
and image capturing module. Moreover, in the drawings, like
reference numerals designate corresponding parts throughout the
several views.
[0008] FIG. 1 is an isometric view of a voice coil motor in
accordance with one embodiment.
[0009] FIG. 2 is an exploded view of the voice coil motor of FIG.
1.
[0010] FIG. 3 is similar to FIG. 2, but shows the voice coil motor
in an opposite view.
[0011] FIG. 4 is a cross-sectional view of the voice coil motor of
FIG. 1 taken along a diagonal line.
[0012] FIG. 5 is a cross-sectional view of the voice coil motor of
the voice coil motor of FIG. 1 taken along a central parting
line.
[0013] FIG. 6 is an isometric view of an image capturing module in
accordance with one embodiment.
DETAILED DESCRIPTION
[0014] Embodiments of the present voice coil motor and image
capturing module will now be described in detail below and with
reference to the drawings.
[0015] Referring to FIGS. 1 to 3, a voice coil motor (VCM) 100
includes a cover 10, a frame 20, a base 30, a bottom elastic member
40, a movable receiving cylinder 50, a wire coil 60, a top elastic
member 70, a group of magnetic members 80 and a clamping member 90.
The cover 10, frame 20, and base 30 together form a hollow outside
fixing frame, and the bottom elastic member 40, the movable
receiving cylinder 50, the wire coil 60, the top elastic member 70,
the magnetic members 80, and the clamping member 90 are received in
the fixing frame.
[0016] Referring also to FIGS. 4 and 5, the frame 20 is
substantially rectangular, and includes a top panel 25 having an
opening 26, and four side panels 27. Four tabs 21 extend from an
inner wall of the opening 26 along a central axis direction of the
frame 20, at positions corresponding to four corners of the frame
20. A length of each of the tabs 21 along the central axis
direction is less than a height of the frame 20 and a height of the
receiving cylinder 50. The tabs 21 define a plurality of first
spaces between the inner wall of the frame 20 and the tabs 21. The
top panel 25 further defines four through holes 22 at the positions
corresponding to the four corners of the frame 20.
[0017] The receiving cylinder 50 has an inner receiving space 55
for receiving a lens module 201 (see FIG. 6). The receiving space
55 has an inner thread formed in the inner wall. The receiving
cylinder 50 includes a first end and an opposite second end, with
the first end located at an object side of the lens module and the
second end located at an image side of the lens module. The
receiving cylinder 50 has a plurality of protrusions 53 formed at
an edge of the first end, and has a rim 52 formed at an outer wall
adjacent to the second end. A plurality of ribs 51 are formed on
the outer wall and extend upwards from the rim 52 along a direction
parallel to a central axis of the receiving cylinder 50. The wire
coil 60 is fixed on the rim 52, and each adjacent two of the ribs
51 defines a number of second spaces between the wire coil 60 and
the outer wall of the receiving cylinder 50. Each of the tabs 21
extends into one of the second spaces when the receiving cylinder
50 is received in the frame 20. The tabs 21 are shorter than a
height of the second space, thereby providing a movement space for
the receiving cylinder 50 (see FIG. 4).
[0018] The magnetic members 80 are fixed on the inner wall of the
frame 20 in the respective first space, and surround the wire coil
60. A height of each of the magnetic members 80 is less than a
height of the receiving cylinder 50. A magnetic force between the
magnetic members 80 and the wire coil 60 provides a driving force
for driving the receiving cylinder 50 to move along the central
axis direction of the frame 20 when a current is applied to the
wire coil 60.
[0019] The top elastic member 70 is ring-shaped, and includes a
resilient central portion 71 and a peripheral portion 72
surrounding the central portion 71. A plurality of slots 75 are
formed between the central portion 71 and the peripheral portion 72
to provide elasticity for the central portion 71. The central
portion 71 defines a central through hole 74, and a plurality of
cutouts 73 formed in an inner wall of the central through hole 74.
The top elastic member 70 is placed at the end of the receiving
cylinder 50, with the protrusions 53 of the receiving cylinder 50
engaged in the cutouts 73 of the top elastic member 70.
[0020] The clamping member 90 is also a ring-shaped, and has a
central through hole 91. The clamping member 90 is placed between
the top panel 25 of the frame 20 and the top elastic member 70, and
the central portion 71 of the top elastic member 70 extend through
the central through hole 91 of the clamping member 90. The cover 10
has four protruding columns 12 corresponding to the through holes
22 of the top panel 25 of the frame 20, and the protruding columns
12 extend through the through holes 22 to abut against the clamping
member 90, thus the clamping member 90 clamps the peripheral
portion 72 of the top elastic member 70 on the magnetic members
80.
[0021] Due to the peripheral portion 72 of the top elastic member
70 clamping towards the magnetic members 80 (which is shorter than
the receiving cylinder 50), and the central portion 71 of the top
elastic member 70 engaging with the protrusions 53 of the receiving
cylinder 50, an elastic pressing force is applied on the receiving
cylinder 50 toward the image side. In this way, when no current is
applied to the wire coil 60, i.e., when the VCM 100 is not
initiated, the receiving cylinder 50 is pressed toward the image
side, thus shaking of the receiving cylinder 50 together with the
lens module 201 (see FIG. 6) can be avoided therein because the
entire module is taken downwards. The pressing force can counteract
the gravitational force of the receiving cylinder 50.
[0022] A part of the bottom elastic member 40 is fixed to the
receiving cylinder 50, and another part of the bottom elastic
member 40 is fixed to the base 30. When no current is applied to
the wire coil 60, the receiving cylinder 50 sits on the base 30,
and the bottom elastic member 40 is in an undeformed state.
[0023] With the above configuration, when the VCM 100 is not
initiated, the receiving cylinder 50 only bears the pressure from
the top elastic member 70. If a coefficient of rigidity of the top
elastic member 70 is K, a deformation amount is AY, then the
pressure can be expressed as F=KAY. The less the pressure the
receiving cylinder 50 bears, the lower precision the mold and the
molding of the receiving cylinder 50 will be. That is, the mold and
the molding of the receiving cylinder 50 will have more tolerance
of the precision thereof.
[0024] When a current is applied to the wire coil 60, i.e., when
the VCM 100 is initiated, the bottom elastic member 40 can have
deformation, and the top elastic member 70 can also have further
deformation.
[0025] Referring to FIG. 6, the lens module 201 received in the
receiving cylinder can include a lens barrel and a plurality of
lenses received in the lens barrel. The lens barrel has an outer
thread to threadedly engage in the receiving cylinder. The VCM 100
and the lens module 201 form an image capturing module 200
applicable in a camera, a mobile phone and other electronic
devices.
[0026] It is understood that the above-described embodiments are
intended to illustrate rather than limit the disclosure. Variations
may be made to the embodiments and methods without departing from
the spirit of the disclosure. Accordingly, it is appropriate that
the appended claims be construed broadly and in a manner consistent
with the scope of the disclosure.
* * * * *