U.S. patent application number 15/975864 was filed with the patent office on 2018-09-13 for lens actuator.
This patent application is currently assigned to Samsung Electro-Mechanics Co., Ltd.. The applicant listed for this patent is Samsung Electro-Mechanics Co., Ltd.. Invention is credited to Jae Ho BAIK, Hoon Heo, Jung Wook Hwang, Jae Hyuk Lee, Jung Seok Lee, Yong Joon Park.
Application Number | 20180259740 15/975864 |
Document ID | / |
Family ID | 49857492 |
Filed Date | 2018-09-13 |
United States Patent
Application |
20180259740 |
Kind Code |
A1 |
BAIK; Jae Ho ; et
al. |
September 13, 2018 |
LENS ACTUATOR
Abstract
There is provided a lens actuator, including: a lens barrel in
which at least one lens is provided on an optical axis; a magnetic
part provided on one surface of the lens barrel; and a printed
circuit board in which a coil pattern part generating
electromagnetic force is provided, the printed circuit board having
one surface facing the magnetic part, wherein magnetic material is
provided on the other surface of the printed circuit board.
Inventors: |
BAIK; Jae Ho; (Suwon-si,
KR) ; Heo; Hoon; (Suwon-si, KR) ; Lee; Jung
Seok; (Suwon-si, KR) ; Lee; Jae Hyuk;
(Suwon-si, KR) ; Park; Yong Joon; (Suwon-si,
KR) ; Hwang; Jung Wook; (Suwon-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Samsung Electro-Mechanics Co., Ltd. |
Suwon-si |
|
KR |
|
|
Assignee: |
Samsung Electro-Mechanics Co.,
Ltd.
Suwon-si
KR
|
Family ID: |
49857492 |
Appl. No.: |
15/975864 |
Filed: |
May 10, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14012896 |
Aug 28, 2013 |
9995902 |
|
|
15975864 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 7/08 20130101; G02B
7/04 20130101 |
International
Class: |
G02B 7/04 20060101
G02B007/04; G02B 7/08 20060101 G02B007/08 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 10, 2012 |
KR |
10-2012-0112608 |
Claims
1. A lens actuator, comprising: a lens barrel in which at least one
lens is provided on an optical axis; a magnetic part provided on
one surface of the lens barrel; and a printed circuit board in
which a coil pattern part generating electromagnetic force is
provided, the printed circuit board having one surface facing the
magnetic part, wherein magnetic material is provided on the other
surface of the printed circuit board.
2. The lens actuator of claim 1, wherein the coil pattern part is a
metal layer patterned on the printed circuit board.
3. The lens actuator of claim 1, wherein the coil pattern part is a
winding coil embedded in the printed circuit board.
4. The lens actuator of claim 1, wherein the printed circuit board
has an integrated circuit component mounted therein.
5. The lens actuator of claim 1, wherein the printed circuit board
has a position sensor mounted therein to sense the position of the
lens barrel.
6. The lens actuator of claim 5, wherein the coil pattern part
surrounds the position sensor.
7. The lens actuator of claim 1, wherein the magnetic material is
magnetic paste.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 14/012,896 filed on Aug. 28, 2013 which claims the benefit
under 35 USC .sctn. 119(a) of Korean Patent Application No.
10-2012-0112608 filed on Oct. 10, 2012, in the Korean Intellectual
Property Office, the entire disclosures of each which are
incorporated herein by reference for all purposes.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention relates to a lens actuator, and more
particularly, to a lens actuator of which a manufacturing process
is simplified and preventing foreign objects from being introduced
thereto during the process.
2. Description of the Related Art
[0003] In general, it is common nowadays for mobile terminals such
as mobile phones, PDAs, portable computers to not only transmit
text messages and voice data but also image data.
[0004] Following this trend, recent mobile communications terminals
are standardly equipped with camera modules and are able to
transmit image data or allow users to make video calls.
[0005] In a camera module provided in a mobile communications
terminal, a lens moving device is provided to allow for lens
zooming or focusing by moving a lens in the optical direction.
[0006] The lens moving device may be divided into three types,
i.e., a rotation motor type, a piezoelectric actuator (PZT) type,
and a voice coil motor (VCM) type, following the manner in which
driving force is generated.
[0007] The rotation motor type has a relatively complicated
structural mechanism, since it needs to convert rotary motion into
linear motion. The PZT type is advantageous in that it is small and
light but is disadvantageous in that it requires a high voltage
power source.
[0008] The VCM type uses electromagnetic force between a coil
through which current flows and the flux of a magnet to directly
move a lens barrel having the coil or magnet attached thereto in
the optical direction, and has advantages in that it has a simple
structure and is operable at low voltage.
[0009] However, the existing lens actuator of VCM type requires
separation space between a coil and a position sensor, and requires
a separate process to electrically connect the coil and the
position sensor to a printed circuit board, such that the process
is complicated, and reliability is lowered if the assembly
tolerance is large.
[0010] Further, foreign objects may be generated during soldering
to contaminate the inside of the lens actuator, thereby lowering
the reliability.
[0011] Patent Document 1 discloses a camera module having a
structure in which an electromagnetic part and a hole sensor are
mounted in a yoke.
RELATED ART DOCUMENT
[0012] (Patent Document 1) Korean Patent Laid-Open Publication No.
2011-0064147
SUMMARY OF THE INVENTION
[0013] An aspect of the present invention provides a lens actuator
having a simplified manufacturing process, reduced manufacturing
costs, and preventing foreign objects from being introduced thereto
during the manufacturing process by connecting a coil and circuit
components to a printed circuit board without using wire
bonding.
[0014] An aspect of the present invention also provides a lens
actuator having a simplified manufacturing process due to a
reduction in a number of components used therein by applying
magnetic material to a printed circuit board without requiring a
separate yoke member.
[0015] An aspect of the present invention also provides a lens
actuator capable of being reduced in size by reducing separation
space between a coil, circuit components and a yoke.
[0016] According to an aspect of the present invention, there is
provided a lens actuator, including: a lens barrel in which at
least one lens is provided on an optical axis; a magnetic part
provided on one surface of the lens barrel; and a printed circuit
board in which a coil pattern part generating electromagnetic force
is provided, the printed circuit board having one surface facing
the magnetic part, wherein magnetic material is provided on the
other surface of the printed circuit board.
[0017] The coil pattern part may be a metal layer patterned on the
printed circuit board.
[0018] The coil pattern part may be a winding coil embedded in the
printed circuit board.
[0019] The printed circuit board may have an integrated circuit
component mounted therein.
[0020] The printed circuit board may have a position sensor mounted
therein to sense the position of the lens barrel.
[0021] The coil pattern part may surround the position sensor.
[0022] The magnetic material may be magnetic paste.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The above and other aspects, features and other advantages
of the present invention will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0024] FIG. 1 is an exploded perspective view of a lens actuator
according to an embodiment of the present invention;
[0025] FIG. 2 is a perspective view of the front of a printed
circuit board according to an embodiment of the present
invention;
[0026] FIG. 3 is a perspective view of the rear of a printed
circuit board according to an embodiment of the present invention;
and
[0027] FIG. 4 is a cross-sectional view taken along line A-A' of
FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Hereinafter, embodiments of the present invention will be
described in detail with reference to the accompanying drawings.
The invention may, however, be embodied in many different forms and
should not be construed as being limited to the embodiments set
forth herein. Rather, these embodiments are provided so that this
disclosure will be thorough and complete, and will fully convey the
scope of the invention to those skilled in the art. In the
drawings, the shapes and dimensions of elements may be exaggerated
for clarity, and the same reference numerals will be used
throughout to designate the same or like elements.
[0029] Firstly, the term "optical axis direction" is defined as a
vertical direction with respect to ".largecircle." shown in FIG.
1.
[0030] FIG. 1 is an exploded perspective view of a lens actuator
according to an embodiment of the present invention.
[0031] Referring to FIG. 1, the lens actuator according to the
embodiment of the present invention may include a lens barrel 100,
a magnetic part 200, a printed circuit board 300, a housing 400 and
a cover 500.
[0032] The lens barrel 100 is a hollow cylinder in which at least
one lens may be provided on the optical axis.
[0033] The lens barrel 100 is coupled to the housing 400 so that it
is movable on the optical axis, and the magnetic part 200 may be
provided on a part of the surface of the lens barrel 100 as a
driving unit for moving the lens barrel 100 in the optical
direction.
[0034] By providing the magnetic part 200 on the part of the
surface of the lens barrel 100, the lens barrel 100 can be moved in
the optical direction by the interaction between a coil pattern
part 310 provided on the printed circuit board 300 and the magnetic
part 200.
[0035] That is, the magnetic part 200 generates a constant magnetic
field, and electromagnetic interaction occurs between the magnetic
part 200 and the coil pattern part 310 when the coil pattern part
310 is powered, such that the lens barrel 100 can be moved in the
optical axis direction by Lorentz force generated in the vertical
direction due to current and magnetic field.
[0036] Here, the shape of the magnetic part 200 is not specifically
limited, as long as it is possible to move the lens barrel 100 in
the optical axis direction by the electrical interaction with the
coil pattern part 310.
[0037] The external power may be provided by the printed circuit
board 300, specifically by the power connection terminal 340 of the
printed circuit board 300.
[0038] The housing 400 is to support the lens barrel 100, in which
the lens barrel 100 is accommodated.
[0039] Accordingly, the housing 400 may have internal space to
accommodate the lens barrel 100, and the shapes of the housing 400
and the internal space are not specifically limited.
[0040] The cover 500 may have a shape to cover the lens barrel 100
moving in the optical axis direction and the housing 400, and may
be coupled to the housing 400.
[0041] The printed circuit board 300 may have the coil pattern part
310 and a position sensor 320 provided therein.
[0042] The detailed configuration of the printed circuit board 300
will be described in detail with reference to FIGS. 2 to 4.
[0043] The printed circuit board 300 may be coupled to the housing
400 so that its one surface faces the magnetic part 200.
[0044] Accordingly, the coil pattern part 310 provided on the
printed circuit board 300 and the magnetic part 200 provided on the
one surface of the lens barrel 100 may face and interact with each
other to generate the Lorentz force.
[0045] After the lens barrel 100 and the printed circuit board 300
are coupled to the housing 400, the cover 500 is coupled therewith
to protect the lens actuator from external impacts.
[0046] FIG. 2 is a perspective view of the front of a printed
circuit board provided in a lens actuator, according to an
embodiment of the present invention; FIG. 3 is a perspective view
of the rear of a printed circuit board provided in a lens actuator,
according to an embodiment of the present invention; and FIG. 4 is
a cross-sectional view taken along line A-A' of FIG. 2.
[0047] Referring to FIGS. 2 to 4, the printed circuit board 300
provided in a lens actuator according to an embodiment may have a
coil pattern part 310 and a position sensor 320 therein.
[0048] The coil pattern part 310 may be a winding coil pattern
embedded in the printed circuit board 300 or may be a metal layer
patterned in the printed circuit board 300.
[0049] Here, the coil pattern part 310 is formed in and
electrically connected to the printed circuit board 300 internally,
such that no separate wire bonding is required, thereby simplifying
the manufacturing process.
[0050] Additionally, in case of wire bonding, foreign objects
generated during the process may contaminate the inside of a lens
actuator so that reliability may be lowered. However, in the case
that the coil pattern part 310 and the printed circuit board 300
are electrically connected within the printed circuit board 300 as
described above, the above problem can be avoided.
[0051] The coil pattern part 310 electrically connected to the
printed circuit board 300 may generate electromagnetic force to
move the lens barrel 100 upon receiving current from the printed
circuit board 300.
[0052] In addition, the coil pattern part 310 may have an outer
surface conforming to an outer surface of the magnetic part 200
provided on one surface of the lens barrel 100.
[0053] In the lens actuators according to the related art, instead
of forming a coil pattern inside a printed circuit board, a coil
separated from a printed circuit board is mounted on the upper
surface of a printed circuit board, such that the winding shape of
the coil cannot be freely chosen. In the coil pattern part 310
according to the embodiment of the present invention, however, the
shape of the coil may be determined according to the shape of the
magnetic part 200, thereby improving magnetic and spatial
efficiency.
[0054] The location sensor 320 may be mounted in the printed
circuit board 300.
[0055] Here, the position sensor 320 is mounted in and electrically
connected to the printed circuit board 300 internally, such that no
separate wire bonding is required. Accordingly, like the coil
pattern part 310, the manufacturing process can be simplified and
the reliability can be improved.
[0056] Further, by mounting the position sensor 320 in the printed
circuit board 300, no separation space between the position sensor
320 in the housing 400 is required, such that the lens actuator can
be reduced in size and manufacturing tolerance during the
manufacturing process can be reduced.
[0057] The position sensor 320 senses a current position of the
lens barrel 100 to provide it to a control unit (not shown), and
the control unit (not shown) uses the information on the current
position of the lens barrel 100 received from the position sensor
320 and information on a target position to which the lens barrel
100 is moved so as to apply an appropriate current to the coil
pattern part 310, thereby controlling the movement of the lens
barrel 100.
[0058] Although the position sensor 320 is mounted in the printed
circuit board 300 in this embodiment, the present invention is not
limited to the position sensor 320 but other circuit components may
be mounted in the printed circuit board.
[0059] That is, as a driving chip for driving the lens actuator
according to the embodiment of the present invention, an integrated
circuit (IC) component may be mounted in the printed circuit board
300.
[0060] Since the integrated circuit (IC) component as well as the
position sensor 320 may be mounted in the printed circuit board
300, the manufacturing process can be simplified.
[0061] One surface of the printed circuit board 300 may face the
magnetic part 200, and magnetic material 330 may be provided on its
other surface.
[0062] Specifically, the magnetic material 330 may be applied to
the other surface of the printed circuit board 300, and may be
magnetic paste. By applying the magnetic material 330 to the other
surface of the printed circuit board 300, magnetic flux may
smoothly flow to the magnetic part 200 through the coil pattern
part 310.
[0063] Conventionally, a separate yoke member is prepared and is
attached to a coil. However, according to the embodiment of the
present invention in which the magnetic material 330 is applied to
the other surface of the printed circuit board 300, components are
reduced in number, thereby simplifying the process.
[0064] As in the above-described embodiment, by including the coil
pattern part 310, the position sensor 320, the integrated circuit
(IC) component and the magnetic material 330 in the printed circuit
board 300, the manufacturing process can be simplified,
manufacturing costs can be reduced and foreign objects generated by
soldering and the like can be prevented.
[0065] In addition, since no separation space between the coil, the
integrated circuit (IC) component and the yoke member is required,
the lens actuator can be reduced in size.
[0066] As set forth above, according to embodiments of the present
invention, the manufacturing process can be simplified,
manufacturing costs can be reduced, and foreign objects can be
prevented from being introduced during the process by way of
connecting a coil and circuit components to a printed circuit board
without using wire bonding.
[0067] Further, the manufacturing process can be simplified due to
a reduction in a number of components by way of applying a magnetic
material to a printed circuit board without requiring a separate
yoke member.
[0068] Moreover, the lens actuator can be reduced in size by way of
reducing separation space between a coil, circuit components and a
magnetic material.
[0069] While the present invention has been shown and described in
connection with the embodiments, it will be apparent to those
skilled in the art that modifications and variations can be made
without departing from the spirit and scope of the invention as
defined by the appended claims.
* * * * *