U.S. patent application number 14/745048 was filed with the patent office on 2015-10-08 for linear vibrator.
The applicant listed for this patent is SAMSUNG ELECTRO-MECHANICS CO., LTD.. Invention is credited to Jin Hoon KIM.
Application Number | 20150283580 14/745048 |
Document ID | / |
Family ID | 49773825 |
Filed Date | 2015-10-08 |
United States Patent
Application |
20150283580 |
Kind Code |
A1 |
KIM; Jin Hoon |
October 8, 2015 |
LINEAR VIBRATOR
Abstract
There is provided a linear vibrator, including: a housing
providing an internal space; an electromagnet having one end fixed
to the housing so as to be disposed in the internal space; a
vibrating part including a magnet facing the electromagnet and
interacting therewith; an elastic member having one end fixed to
the housing and the other end fixed to the vibrating part and
elastically supporting the vibrating part during vibrating thereof;
and a separation prevention member interposed between the other end
of the electromagnet and the housing.
Inventors: |
KIM; Jin Hoon; (Suwon-Si,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG ELECTRO-MECHANICS CO., LTD. |
Suwon-Si |
|
KR |
|
|
Family ID: |
49773825 |
Appl. No.: |
14/745048 |
Filed: |
June 19, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13601857 |
Aug 31, 2012 |
9085013 |
|
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14745048 |
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Current U.S.
Class: |
310/25 |
Current CPC
Class: |
H02K 33/16 20130101;
B06B 1/045 20130101; H02K 33/00 20130101 |
International
Class: |
B06B 1/04 20060101
B06B001/04; H02K 33/00 20060101 H02K033/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 22, 2012 |
KR |
10-2012-0067402 |
Claims
1. A linear vibrator, comprising: a housing providing an internal
space; a magnetic field part having one end fixed to the housing so
as to be disposed in the internal space; a vibrating part including
an electromagnet facing the magnetic field part and interacting
therewith; an elastic member having one end fixed to the housing
and the other end fixed to the vibrating part and elastically
supporting the vibrating part during vibrating thereof; and a
separation prevention member interposed between the other end of
the magnetic field part and the housing.
2. The linear vibrator of claim 1, wherein the other end of the
magnetic field part is provided with a yoke.
3. The linear vibrator of claim 1, wherein the magnetic field part
includes a yoke fixed to the housing and a magnet inserted into the
yoke.
4. The linear vibrator of claim 3, wherein one end of the yoke is
inserted into a seating groove or a seating hole formed in the
housing.
5. The linear vibrator of claim 3, wherein the other end of the
yoke is provided with a flange protruded in an outer radial
direction.
6. The linear vibrator of claim 1, further comprising a shock
absorbing member inserted between the separation prevention member
and the other end of the magnetic field part.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser.
No. 13/601,857, filed on Aug. 31, 2012, which claims the priority
of Korean Patent Application No. 10-2012-0067402 filed on Jun. 22,
2012, in the Korean Intellectual Property Office, the disclosures
of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a linear vibrator.
[0004] 2. Description of the Related Art
[0005] In recent years, a personal mobile terminal having a large
liquid crystal display (LCD) screen for a user's convenience has
been increasingly released onto the market. In line with this
trend, a touch screen type display device has been greatly favored,
and a vibration motor has been used so as to generate vibrations
when a touch is applied to a touch screen.
[0006] A vibration motor transforms electrical energy into
mechanical energy using a principle of generating electromagnetic
force, is mounted on a personal mobile terminal, and is used for
silent call reception notification.
[0007] According to the related art, rotatory power is generated to
rotate a rotational part of an unbalance mass, thereby obtaining
mechanical vibrations. In this case, rotatory power is generated
such that it is subjected to a rectifying action through a brush
and a contact point of a commutator (or rectifier) to obtain
mechanical vibrations.
[0008] However, in the brush type structure using a commutator,
when the motor rotates, the brush passes through a gap between
segments of the commutator, causing mechanical friction and an
electrical spark, producing foreign objects and thereby shortening
the life span of the motor.
[0009] In addition, because voltage is applied to the motor by
using a moment of inertia, time is taken to reach a target amount
of vibrations, so it is difficult to implement vibrations suitable
for a touch screen.
[0010] In order to overcome such disadvantages in terms of the life
span and response of the motor and implement the vibration function
of the touch screen, a linear vibrator is increasingly being
used.
[0011] A linear vibrator, rather than using the rotational
principle of the motor, uses the following principle: when
electromagnetic force, obtained by using a spring installed inside
a vibration motor and a mass body hung on the spring, is generated
periodically in conformity with a resonance frequency, resonance is
caused, thereby generating vibrations.
[0012] The linear vibrator needs to be slimmed and efficiently
produced in order to meet a market trend in which miniaturization
and slimness of portable electronic devices are demanded, while
performance and characteristics thereof should not be affected,
even in the case that several different factors are applied.
[0013] In particular, a linear vibrator mounted in an internal
space of a housing largely has a vibrating part and a fixed part,
wherein the fixed part is fixed to the housing and the vibrating
part is vibrated through electromagnetic interaction with the fixed
part. In this configuration, the fixed part, fixed to the housing,
maybe separated from the housing due to an external shock, or the
like, applied to the linear vibrator.
[0014] Patent Document 1 discloses that fixed parts, that is, a
yoke 15 and a coil 14 are fixed to a bracket 11 and only one end
thereof is fixed to the bracket 11 and therefore, the yoke 15 may
be separated from the bracket 11 when an external shock, or the
like, is applied thereto.
RELATED ART DOCUMENT
[0015] (Patent Document 1) Korean Patent No. 10-1101330
SUMMARY OF THE INVENTION
[0016] An aspect of the present invention provides a linear
vibrator capable of maintaining a state in which a fixed part is
firmly fixed to a housing, even in the case that an external shock,
or the like, is applied thereto.
[0017] According to an aspect of the present invention, there is
provided a linear vibrator, including: a housing providing an
internal space; an electromagnet having one end fixed to the
housing so as to be disposed in the internal space; a vibrating
part including a magnet facing the electromagnet and interacting
therewith; an elastic member having one end fixed to the housing
and the other end fixed to the vibrating part and elastically
supporting the vibrating part during vibrating thereof; and a
separation prevention member interposed between the other end of
the electromagnet and the housing.
[0018] The linear vibrator may further include a shock absorbing
member inserted between the separation prevention member and the
other end of the electromagnet.
[0019] At least a portion of the separation prevention member may
be formed of an elastomer.
[0020] The separation prevention member may be formed of a magnetic
material.
[0021] The separation prevention member may be formed of a
non-magnetic material.
[0022] The housing may include an external wall protruded into the
internal space, and the separation prevention member may be
inserted into an interior of the external wall.
[0023] The electromagnet may include a yoke fixed to the housing
and a coil wound around the yoke.
[0024] One end of the yoke may be inserted into a seating groove or
a seating hole formed in the housing.
[0025] The other end of the yoke may be provided with a flange
protruded in an outer radial direction.
[0026] The flange may be disposed to face the magnet.
[0027] According to another aspect of the present invention, there
is provided a linear vibrator, including: a housing providing an
internal space; a magnetic field part having one end fixed to the
housing so as to be disposed in the internal space; a vibrating
part including an electromagnet facing the magnetic field part and
interacting therewith; an elastic member having one end fixed to
the housing and the other end fixed to the vibrating part and
elastically supporting the vibrating part during vibrating thereof;
and a separation prevention member interposed between the other end
of the magnetic field part and the housing.
[0028] The other end of the magnetic field part may be provided
with a yoke.
[0029] The magnetic field part may include a yoke fixed to the
housing and a magnet inserted into the yoke.
[0030] One end of the yoke may be inserted into a seating groove or
a seating hole formed in the housing.
[0031] The other end of the yoke may be provided with a flange
protruded in an outer radial direction.
[0032] The linear vibrator may further include a shock absorbing
member inserted between the separation prevention member and the
other end of the magnetic field part.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] 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:
[0034] FIG. 1 is an exploded perspective view illustrating a linear
vibrator according to an embodiment of the present invention;
[0035] FIGS. 2 and 3 are cross-sectional views illustrating a
linear vibrator according to an embodiment of the present
invention;
[0036] FIG. 4 is an exploded perspective view illustrating a linear
vibrator according to an embodiment of the present invention;
and
[0037] FIGS. 5 and 6 are cross-sectional views illustrating a
linear vibrator according to an embodiment of the present
invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0038] Hereinafter, exemplary embodiments of the present invention
will be described 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.
[0039] Throughout the drawings, the same reference numerals will be
used to designate the same or like elements.
[0040] FIG. 1 is an exploded perspective view illustrating a linear
vibrator according to an embodiment of the present invention, and
FIGS. 2 and 3 are cross-sectional views illustrating a linear
vibrator according to an embodiment of the present invention.
[0041] First, defining terms related to directions, an inner or
outer radial direction may refer to a direction from a center of a
case 112 toward an external circumferential surface of the case
112, and vice versa. In addition, a circumferential direction may
refer to a circumferential direction (including both a clockwise
direction and a counterclockwise direction) of the case 112.
[0042] Referring to FIGS. 1 and 2, a linear vibrator 100 according
to an embodiment of the present invention may include a housing 110
forming an exterior of the linear vibrator 100, a vibrating part
130 including amass body 131, an elastic member 135 and a magnetic
field part 136, an electromagnet 150 including a yoke 152 and a
coil 154, and a substrate 140 for supplying power to the
electromagnet 150. In addition, in the embodiment of the present
invention, a separation prevention member 120 may be interposed
between the electromagnet 150 and the housing 110.
[0043] Here, the magnetic field part 136 may include upper and
lower plates 132 and 134 acting as a yoke and a magnet 133
interposed therebetween. Further, the electromagnet 150 may include
the yoke 152 and the coil 154.
[0044] The housing 110 may include the case 112 having an opened
portion and providing an internal space having a predetermined
volume, and the bracket 114 joined to the opened portion of the
case 112 to seal the internal space formed by the case 112.
[0045] Here, the internal space may accommodate the electromagnet
150, the vibrating part 130, and the like, and the case 112 and the
bracket 114 may also be integrally formed.
[0046] In addition, the bracket 114 may include a sealing portion
114a sealing the opened portion of the case 112 and a protruding
portion 114b protruded to the outside of the case 112 after being
joined to the case 112.
[0047] Meanwhile, an external wall 112a is provided on a top
surface of the case 112 to be protruded downwardly to correspond to
an external edge of the separation prevention member 120 to be
described below to thereby allow the external circumferential
surface of the separation prevention member 120 to be fitted into
an internal surface of the external wall 112a, such that the
external wall 112a of the case 112 can be more firmly joined to the
separation prevention member 120.
[0048] The electromagnet 150 may be fixed to the housing 110 so as
to be mounted in the internal space of the housing 110. The
electromagnet 150 may be joined to the housing 110 (may be mounted
in the case 112 or on the bracket 114) by at least one of bonding,
press-fitting, and welding.
[0049] The electromagnet 150 may have an external diameter smaller
than internal diameters of the upper and lower plates 132 and 134
and the magnet 133 forming the magnetic field part 136 and may act
as a fixed member by being joined to the housing 110 (the case 112
or the bracket 114).
[0050] In this configuration, the electromagnet 150 may be
configured to include the yoke 152 fixed to the housing 110 and the
coil 154 wound around the yoke 152. The yoke 152 may be provided so
as to smooth a flow of magnetic flux during a process of generating
electromagnetic force through interaction between the coil 154 and
the magnet 133 of the vibrating part 130.
[0051] One end of the yoke 152 may be inserted into a seating
groove or a seating hole 114c formed in the housing 110. Further,
the yoke 152 may be fixed to the housing 110 using various methods
such as bonding, press-fitting, welding, and the like, but the
present invention is not limited thereto. FIGS. 1 and 2 show that
the yoke 152 is inserted into the seating hole 114c formed in the
bracket 114, but the present invention is not limited thereto.
Therefore, the seating hole may also be provided as a seating
groove and may fix the yoke to the housing rather than to the
bracket.
[0052] Further, the yoke 152 may include a body 152a inserted into
the housing 110 and a flange 152b protruded from the other end of
the yoke 152 in the outer radial direction. Here, the flange 152b
may be disposed to face the magnet 133 of the vibrating part 130.
This configuration of the yoke 152 may smooth the flow of magnetic
flux during the process of generating electromagnetic force through
interaction between the coil 154 and the magnet 133.
[0053] Here, the yoke 152 may be formed of a magnetic material.
[0054] In addition, a lead wire of the coil 154 may be connected to
the substrate 140 that is mounted in the housing 110. Further, the
substrate 140 may be a flexible circuit board and be directly
attached to a bottom surface of the coil 154 (a method illustrated
in FIG. 5). When current having a predetermined frequency is
applied to the coil 154, a magnetic field may be induced around the
coil 154.
[0055] The vibrating part 130 may include the mass body 131, the
elastic member 135, and the magnetic field part 136. In this
configuration, the magnetic field part 136 may include the upper
and lower plates 132 and 134 and the magnet 133 interposed
therebetween.
[0056] One end of the elastic member 135 may be fixed to the mass
body 131 having the magnetic field part 136 mounted therein and the
other end thereof may be fixed to the housing 110 (fixed to the
case 112 or to the bracket 114).
[0057] The magnetic field part 136 is fixed to the interior of the
mass body 131 to interact with the electromagnet 150 fixed to the
housing 110 so as to face the interior of the magnetic field part
136, such that the magnetic field part 136 may be used to vibrate
the vibrating part 130 relative to the electromagnet 150 via the
elastic member 138.
[0058] That is, the vibrating part 130 may be a member that can
vibrate vertically via the elastic member 135.
[0059] Here, the upper and lower plates 132 and 134 and the magnet
133 may include an internal diameter larger than an external
diameter of the electromagnet 150.
[0060] In detail, the magnetic field part 136 may be disposed to
face the electromagnet 150 and at least a portion of the
electromagnet 150 may be inserted into a space formed by the
magnetic field part 136.
[0061] Therefore, the electromagnet 150 and the magnetic field part
136 may maintain a state of non-contact during the movement of the
vibrating part 130.
[0062] Further, the magnet 133 may be joined to an internal
circumferential surface of a hollow of the mass body 131.
[0063] The mass body 131 is a vibrating body that is vibrated
vertically. When the mass body 131 is vibrated vertically, the mass
body may have an external diameter smaller than an internal
diameter of the internal circumferential surface of the case 112 so
as to be vibrated without coming into contact in the housing
110.
[0064] Therefore, a gap having a predetermined size may be formed
between the internal circumferential surface of the case 112 and
the external circumferential surface of the mass body 131.
[0065] The mass body 131 may be formed of a non-magnetic material
or a paramagnetic material that is not affected by magnetic force
generated by the magnet 133.
[0066] Therefore, the mass body 131 may be formed of a material
such as tungsten having a heavier specific gravity than iron, which
increases a mass of the vibrating part 130 without an increase in
volume to control a resonance frequency, thereby maximizing a
vibration quantity.
[0067] However, a material of the mass body 131 is not limited to
tungsten and various materials can be used according to designer's
intention.
[0068] Here, in order to calibrate a natural frequency of the
linear vibrator 100, the mass body 131 is provided with a space
into which a sub mass body may be inserted, thereby increasing or
reducing the mass of the mass body 131.
[0069] When current having a predetermined frequency is applied to
the coil 154, a magnetic field may be induced around the coil 154.
In this case, when electromagnetic force is propagated through the
coil 154, a direction of magnetic flux through the coil 154 from
the magnet 133 is horizontal, while the magnetic field generated by
the coil 154 is vertically formed to vibrate the vibrating part 130
vertically.
[0070] Therefore, the magnetic flux direction of the magnet 133 and
the vibration direction of the vibrating part 130 are perpendicular
with regard to each other.
[0071] That is, when electromagnetic force having the same
frequency as the natural mechanical frequency of the vibrating part
130 is formed, the vibrating part 130 may be resonance-vibrated to
obtain a maximum quantity of vibrations and the natural frequency
of the vibrating part 130 is affected by the mass of the vibrating
part 130 and an elasticity modulus of the elastic member 135.
[0072] Here, current, namely, external power having a predetermined
frequency, applied to the coil 154 may be provided by the substrate
140 electrically connected to the coil 154, which will be described
below.
[0073] As described above, the elastic member 135 is a member that
is joined to the mass body 131 and the housing 110 (the case 112 or
the bracket 114) to provide elastic force, wherein the natural
frequency of the vibrating part 130 is affected by the elasticity
modulus of the elastic member 135.
[0074] Here, the elastic member 135 may be one of a coil spring and
a leaf spring, but the present invention is not limited thereto.
Therefore, it is to be noted that any member capable of providing
elastic force may be used without limitation.
[0075] The substrate 140 may be electrically connected to the lead
wire of the coil 154 configuring the electromagnet 150.
[0076] The substrate 140 may include a through hole 149 into which
the electromagnet 150 fixed to the housing 110 is inserted during
the process of mounting the substrate 140 in the housing 110. The
substrate 140 may be easily mounted in the housing 110 due to the
through hole 149.
[0077] In detail, the substrate 140 may be mounted so as to be
entirely adhered to the housing 110 and the lead wire of the coil
154 may extend to be electrically connected to the substrate
140.
[0078] Alternatively, the substrate 140 may be a flexible printed
circuit board and may include a moving piece 142 coupled to the
coil 154, a fixed piece 146 coupled to the protruding portion 114b
of the bracket 114, and a connecting piece 144 connecting the
moving piece 142 and the fixed piece 146 to each other.
[0079] The moving piece 142 may be coupled to a bottom surface of
the coil 154 without being adhered to the bracket 114 (please see
the structure for coupling the substrate to the coil of FIG.
5).
[0080] In addition, the internal space formed by the moving piece
142 may refer to the above-mentioned through hole 149.
[0081] A top surface of the fixed piece 146 may be provided with a
power connection terminal 147 for supplying power to the coil 154
and may be protruded to the outside of the case 112.
[0082] Therefore, the fixed piece 146 of the substrate 140 may be
coupled to the protruding portion 114b.
[0083] In addition, the substrate 140 may include the connecting
piece 144 connecting the moving piece 142 and the fixed piece 146
to each other, wherein the connecting piece 144 may be provided to
be pivoted in a circumferential direction of the moving piece 142
from an end of the fixed piece 146 at a predetermined gap with
respect to an edge of the moving piece 142.
[0084] In addition, the bottom surface of the substrate 140 may be
provided with an electrode pad (not shown) for transferring an
electrical signal having a specific frequency to the coil 154 and
the electrode pad may be electrically connected to the lead wire of
the coil 154.
[0085] Here, the electrode pad may be formed further outwardly than
the external edge of the coil 154 and the electrode pad, and the
electrode pad and the lead wire of the coil 154 may be electrically
connected by soldering.
[0086] In other words, the electrode pad may be formed on the
bottom surface of the moving piece 142 of the substrate 140 to be
coupled to the lead wire of the coil 154.
[0087] The separation prevention member 120 may be interposed
between the other end of the electromagnet 150 and the housing 110.
In detail, when the other end of the electromagnet 150 is fixed to
the bracket 114, the separation prevention member 120 may be
interposed between the other end of the electromagnet 150 and the
case 112.
[0088] The linear vibrator mounted in the internal space of the
housing 110 is largely divided into the vibrating part and the
fixed part, wherein the fixed part is fixed to the housing and the
vibrating part is vibrated by the electromagnetic interaction with
the fixed part. In this configuration, the fixed part fixed to the
housing may be separated from the housing due to an external shock
applied to the linear vibrator, or the like. Therefore, the present
invention may additionally include the separation prevention member
120 capable of firmly fixing the electromagnet 150 corresponding to
the fixed part.
[0089] That is, one end of the electromagnet 150 is a fixed end
fixed to the bracket 114 and the other end thereof is a free end,
which results in an unstable structure. Therefore, the free end is
changed to the fixed end by the addition of the separation
prevention member connected to the case 112, such that the
electromagnet 150 may be firmly fixed even in the case that an
external shock, or the like, is applied thereto.
[0090] Herein, the separation prevention member 120 may be formed
of a magnetic or a non-magnetic material. In the case that the
separation prevention member 120 is formed of a magnetic material,
the separation prevention member 120 may act as the yoke to smooth
the flow of magnetic flux. In addition, in the case that the
separation prevention member 120 is formed of a non-magnetic
material, the separation prevention member 120 can prevent the
leakage of magnetic flux.
[0091] In addition, at least a portion of the separation prevention
member 120 may be formed of an elastomer to act as a shock
absorbing member. That is, the separation prevention member 120 is
inserted between the other end of the electromagnet 150 and the
case 112. Therefore, when the separation prevention member 120 is
formed of a material having elastic force to a certain degree, the
separation prevention member 120 is interposed between the other
end of the electromagnet 150 and the case 112 and then elastically
recovered, thereby more firmly fixing the electromagnet 150.
[0092] Here, at least a portion of the separation prevention member
120 is formed of a material capable of absorbing shock such as
rubber, silicon, cork, propylene, poron, and the like, or may be
configured as a spring having elastic force, and the like.
[0093] Meanwhile, the housing 110 includes the external wall 112a
protruded to the internal space and the separation prevention
member 120 may be inserted into the interior of the external wall
112a. The external wall 112a may more firmly fix the separation
prevention member 120. In addition, the external wall 112a may also
act to guide the position of the separation prevention member
120.
[0094] In addition, referring to FIG. 3, the linear vibrator 200
according to the embodiment of the present invention may further
include a shock absorbing member 121 inserted between the
separation prevention member 120 and the other end of the
electromagnet 150.
[0095] That is, even in the case that the separation prevention
member 120 does not include an elastomer, the additional shock
absorbing member is provided to obtain a shock absorbing effect.
The separation prevention member 120 is inserted between the other
end of the electromagnet 150 and the case 112. In the case in which
the separation prevention member 120 is formed of a rigid body, a
gap is inevitably formed, even in the case that the separation
prevention member 120 is inserted between the other end of the
electromagnet 150 and the case 112, such that the electromagnet 150
may be separated due to an external shock, or the like. Therefore,
the shock absorbing member 121 having elastic force may
additionally be inserted between the electromagnet 150 and the
separation prevention member 120 to allow the separation prevention
member 120 to be inserted between the other end of the
electromagnet 150 and the case 112 and then, elastically recover
the shock absorbing member 121, thereby more firmly fixing the
electromagnet 150.
[0096] Here, the shock absorbing member 121 is formed of a material
such as rubber, silicon, cork, propylene, poron, and the like,
capable of absorbing shocks, or may be configured as a spring
having elastic force, and the like.
[0097] FIG. 4 is an exploded perspective view illustrating a linear
vibrator according to an embodiment of the present invention, and
FIGS. 5 and 6 are cross-sectional views illustrating a linear
vibrator according to an embodiment of the present invention.
[0098] When linear vibrators 300 and 400 according to an embodiment
of the present invention are compared with the linear vibrators 100
and 200 illustrated in FIGS. 1 through 3, the electromagnet and the
magnetic field part are positioned opposite to each other.
[0099] That is, the linear vibrators 100 and 200 of FIGS. 1 through
3 have a structure in which the magnetic field part 136 including
the magnet 133 is mounted in the vibrating part 130 and the
electromagnet 150 is mounted in the housing 110 (the bracket 114),
the fixed part. On the other hand, the linear vibrators 300 and 400
of FIGS. 4 through 6 have a structure in which an electromagnet 336
is mounted in a vibration part 330 and a magnetic field part 350
including a magnet 354 is mounted in a housing 310 (a bracket 314),
the fixed part.
[0100] Referring to FIGS. 4 and 5, the linear vibrator 300
according to the embodiment of the present invention may include
the housing 310 forming an interior of the linear vibrator 300, the
vibrating part 330 including a mass body 331, an elastic member 335
and the electromagnet 336, the magnetic field part 350 including a
yoke 352 and the magnet 354, and a substrate 340 for supplying
power to the electromagnet 336. In addition, in the embodiment of
the present invention, a separation prevention member 320 may be
interposed between the magnetic field part 350 and the housing
310.
[0101] Here, the electromagnet 336 may include an upper plate 332
acting as a yoke and a coil 333. Further, the magnetic field part
350 may include the yoke 352 and the magnet 354.
[0102] The housing 310 may include the case 312 having an opened
portion and providing an internal space having a predetermined
volume and a bracket 314 joined to the opened portion of the case
312 to seal the internal space formed by the case 312.
[0103] Here, the internal space may accommodate the magnetic field
part 350, the vibrating part 330, and the like, and the case 312
and the bracket 314 may also be formed integrally.
[0104] In addition, the bracket 314 may include a sealing portion
314a sealing the opened portion of the case 312 and a protruding
portion 314b protruded to the outside of the case 312 after being
joined to the case 312.
[0105] Meanwhile, an external wall 312a is provided on a top
surface of the case 312 to be protruded downwardly to correspond to
an external edge of the separation prevention member 320 to be
described below to thereby allow the external circumferential
surface of the separation prevention member 320 to be fitted into
an internal surface of the external wall 312a, such that the
external wall 312a of the case 312 can be more firmly joined to the
separation prevention member 320.
[0106] The magnetic field part 350 may be fixed to the housing 310
so as to be mounted in the internal space of the housing 310. The
magnetic field part 350 may be joined to the housing 310 (may be
mounted in the case 312 or on the bracket 314) by at least one of
bonding, press fitting, and welding.
[0107] The magnetic field part 350 may have an external diameter
smaller than internal diameters of the upper plate 332 and the coil
333 forming the electromagnetic 336 and may act as a fixed member
by being joined to the housing 310 (the case 312 or the bracket
314).
[0108] In this configuration, the magnetic field part 350 may be
configured to include the yoke 352 fixed to the housing 310 and the
magnet 354 inserted into the yoke 152. The yoke 352 may be provided
so as to smooth a flow of magnetic flux during a process of
generating electromagnetic force by interaction between the magnet
354 and the coil 333 of the vibrating part 330.
[0109] Meanwhile, although not shown, the magnetic field part 350
may include a magnet of which one end is mounted in the housing
310. Here, the other end of the magnet may be provided with the
yoke.
[0110] One end of the yoke 352 may be inserted into a seating
groove or a seating hole 314c formed in the housing 310. Further,
the yoke 352 may be fixed to the housing 310 using various methods
such as bonding, press-fitting, welding, and the like, but the
present invention is not limited thereto. FIGS. 4 and 5 show that
the yoke 352 is inserted into the seating hole 314c formed in the
bracket 314, but the present invention is not limited thereto.
Therefore, the seating hole may be provided as a seating groove and
may fix the yoke to the housing rather than to the bracket.
[0111] Further, the yoke 352 may include a body 352a inserted into
the housing 310 and a flange 352b protruded outwardly from the
other end of the body 352a in the outer radial direction.
[0112] Here, the flange 352b may be disposed to face the coil 333
of the vibrating part 330. This configuration of the yoke 352 may
smooth the flow of magnetic flux during the process of generating
electromagnetic force through interaction between the magnet 354
and the coil 333.
[0113] Here, the yoke 352 maybe formed of a magnetic material.
[0114] The vibrating part 330 may include the mass body 331, the
elastic member 335, and the electromagnet 336. Here, the
electromagnet 336 may include the upper plate 332 and the coil
333.
[0115] One end of the elastic member 335 may be fixed to the mass
body 331 having the electromagnet 336 mounted therein and the other
end thereof may be fixed to the housing 310 (fixed to the case 312
or the bracket 314).
[0116] The electromagnet 336 is fixed to the interior of the mass
body 331 to interact with the magnetic field part 350 fixed to the
housing 310 so as to face the interior of the electromagnet 336,
such that the electromagnet 336 may be implemented to vibrate the
vibrating part 330 relative to the magnetic field part 350 via the
elastic member 335.
[0117] That is, the vibrating part 330 may be a member that can
vibrate vertically via the elastic member 335.
[0118] Here, the upper plate 332 and the coil 333 may have an
internal diameter larger than the external diameter of the magnetic
field part 350.
[0119] In detail, the electromagnet 336 may be disposed to face the
magnetic field part 350 and at least a portion of the magnetic
field part 350 may be inserted into a space formed by the
electromagnet 336.
[0120] Therefore, the magnetic field part 350 and the electromagnet
336 may maintain a state of non-contact during the movement of the
vibrating part 330.
[0121] Further, the coil 333 may be joined to an internal
circumferential surface of a hollow of the mass body 331.
[0122] The mass body 331 is a vibrating body that is vibrated
vertically. When the mass body 331 is vibrated vertically, the mass
body may be provided to have an external diameter smaller than an
internal diameter of the internal circumferential surface of the
case 312 so as to be vibrated without coming into contact in the
housing 310.
[0123] Therefore, a gap having a predetermined size may be formed
between the internal circumferential surface of the case 312 and
the external circumferential surface of the mass body 331.
[0124] The mass body 331 may be formed of a non-magnetic material
or a paramagnetic material that is not affected by magnetic force
generated by the magnet 354.
[0125] Therefore, the mass body 331 may be formed of a material
such as tungsten having a heavier specific gravity than iron, which
increases a mass of the vibrating part 330 without an increase in
volume to control a resonance frequency, thereby maximizing a
vibration quantity.
[0126] However, a material of the mass body 331 is not limited to
tungsten and therefore, various materials can be used according to
designer's intention.
[0127] Here, in order to calibrate a natural frequency of the
linear vibrator 300, the mass body 331 is provided with a space
into which a sub mass body may be additionally inserted, thereby
increasing or reducing the mass of the mass body 331.
[0128] When current having a predetermined frequency is applied to
the coil 333, a magnetic field may be induced around the coil 333.
In this case, when electromagnetic force is propagated through the
coil 333, a direction of magnetic flux through the coil 333 from
the magnet 354 is horizontal and the magnetic field generated by
the coil 333 is vertical, to vibrate the vibrating part 330
vertically.
[0129] Therefore, the magnetic flux direction of the magnet 354 and
the vibration direction of the vibrating part 330 are perpendicular
with respect to each other.
[0130] That is, when electromagnetic force having the same
frequency as the natural mechanical frequency of the vibrating part
330 is formed, the vibrating part 330 may be resonance-vibrated to
obtain a maximum quantity of vibrations and the natural frequency
of the vibrating part 330 is affected by the mass of the vibrating
part 330 and an elasticity modulus of the elastic member 335.
[0131] Here, current, namely, external power having a predetermined
frequency, applied to the coil 333, may be provided by the
substrate 340 electrically connected to the coil 333, which will be
described below.
[0132] As described above, the elastic member 335 is joined to the
mass body 331 and the housing 310 (the case 312 or the bracket 314)
and provides elastic force, wherein the natural frequency of the
vibrating part 330 is affected by the elasticity modulus of the
elastic member 335.
[0133] Here, the elastic member 335 may be one of a coil spring and
a leaf spring, but the present invention is not limited thereto.
Therefore, it is to be noted that any member capable of providing
elastic force may be used without limitation.
[0134] The substrate 340 may be coupled to one surface of the mass
body 331 configuring the vibrating part 330 and may include a
through hole 349 passing through the magnet 354 so that the
substrate 340 does not contact the magnetic field part 350 at the
time of the vibration of the vibrating part 330.
[0135] That is, the through hole 349 may prevent contact between
the magnetic field part 350 and the substrate 340 and may secure
the maximum quantity of vibrations of the vibrating part 330
without limiting amplitude at the time of the vibration and
movement of the vibrating part 330.
[0136] Therefore, the linear vibrator 300 according to the
embodiment of the present invention can obtain more stable linear
vibrations by the through hole 349.
[0137] In detail, one end of the substrate 340 may be coupled to
the vibration part 330 so as to be a free end and the other end
thereof may be coupled to the protruding portion 314b of the
bracket 314 so as to be a fixed end.
[0138] Here, describing the substrate 340 in more detail, the
substrate 340 may be a flexible printed circuit board and may
include a moving piece 342 coupled to the mass body 331 of the
vibrating part 330, a fixed piece 346 coupled to the protruding
portion 314b of the bracket 314, and a connecting piece 344
connecting the moving piece 342 and the fixed piece 346 to each
other.
[0139] The moving piece 342 may be a free end as a portion vibrated
by cooperating with the vibrating part 330 and a top surface of the
moving piece 342 may contact a bottom surface of the mass body
334.
[0140] In addition, the internal space formed by the moving piece
342 may refer to the above-mentioned through hole 349.
[0141] A top surface of the fixed piece 346 may be provided with a
power connection terminal 347 for supplying power to the coil 333
and may be protruded to the outside of the case 312.
[0142] Therefore, the fixed piece 346 of the substrate 340 may be
coupled to the protruding portion 314b.
[0143] In addition, the substrate 340 may include the connecting
piece 344 connecting the moving piece 342 and the fixed piece 346
to each other, wherein the moving piece 342 may be vibrated
vertically while the connecting piece 344 is pivoted in a
circumferential direction of the moving piece 342 from an end of
the fixed piece 346 at a predetermined gap with respect to an edge
of the moving piece 342.
[0144] In addition, the bottom surface of the substrate 340 may be
provided with an electrode pad (not shown) for transferring an
electrical signal having a specific frequency to the coil 333 and
the electrode pad may be electrically connected to a lead wire of
the coil 333.
[0145] Here, the electrode pad may be formed further outwardly than
the external edge of the coil 333 and the electrode pad and the
lead wire of the coil 333 may be electrically connected to each
other by soldering.
[0146] In other words, the electrode pad may be formed on the
bottom surface of the moving piece 342 of the substrate 340 to be
coupled to the lead wire of the coil 333.
[0147] Therefore, the lead wire of the coil 333 does not affect
vibrations and movement of the linear vibrator 300 according to the
embodiment of the present invention by coupling the electrode pad
of the substrate 340 to the outside of the coil 333.
[0148] The separation prevention member 320 may be interposed
between the other end of the magnetic field part 350 and the
housing 310. In detail, when the other end of the magnetic field
part 350 is fixed to the bracket 314, the separation prevention
member 320 may be interposed between the other end of the magnetic
field part 350 and the case 312.
[0149] The linear vibrator mounted in the internal space of the
housing 310 is largely divided into the vibrating part and the
fixed part, wherein the fixed part is fixed to the housing and the
vibrating part is vibrated by the electromagnetic interaction with
the fixed part. In this configuration, the fixed part fixed to the
housing may be separated from the housing due to an external shock
applied to the linear vibrator, and the like. Therefore, the
present invention may additionally include the separation
prevention member 320 capable of firmly fixing the magnetic field
part 350 corresponding to the fixed part.
[0150] That is, one end of the magnetic field part 350 is a fixed
end fixed to the bracket 314 and the other end thereof is a free
end, which results in an unstable structure. Therefore, the free
end is changed to the fixed end by the addition of the separation
prevention member connected to the case 312, such that the magnetic
field part 350 may be firmly fixed even in the case that an
external shock, or the like, is applied thereto.
[0151] Herein, the separation prevention member 320 may be a
magnetic or a non-magnetic material. When the separation prevention
member 320 is formed of a magnetic material, the separation
prevention member 320 may act as a yoke to smooth the flow of
magnetic flow. In addition, when the separation prevention member
320 is formed of a non-magnetic material, the separation prevention
member 320 may prevent the leakage of magnetic flux.
[0152] In addition, at least a portion of the separation prevention
member 320 may be formed of an elastomer to act as a shock
absorbing member. The separation prevention member 320 is inserted
between the other end of the magnetic field part 350 and the case
312. Therefore, when the separation prevention member 320 is formed
of a material having elastic force to a certain degree, the
separation prevention member 320 is interposed between the other
end of the magnetic field part 350 and the case 312 and then
elastically recovered, thereby more firmly fixing the magnetic
field part 350.
[0153] Here, at least a portion of the separation prevention member
320 maybe formed of a material having elastic force such as rubber,
silicon, spring, and the like.
[0154] Meanwhile, the housing 310 includes the external wall 312a
protruded to the internal space and the separation prevention
member 320 may be inserted into the interior of the external wall
312a. The external wall 312a may more firmly fix the separation
prevention member 320. In addition, the external wall 312a may also
act to guide the separation prevention member 320 during the
positioning thereof.
[0155] In addition, referring to FIG. 6, the linear vibrator 400
according to the embodiment of the present invention may further
include a shock absorbing member 321 that is inserted between the
separation prevention member 320 and the other end of the magnetic
field part 350.
[0156] That is, even in the case that the separation prevention
member 320 does not include an elastomer, the additional shock
absorbing member is provided to obtain a shock absorbing effect.
That is, the separation prevention member 320 is inserted between
the other end of the magnetic field part 350 and the case 312.
However, in a case in which the separation prevention member 320 is
formed of a rigid body, a gap is inevitably formed, even in the
case that the separation prevention member 320 is inserted between
the other end of the magnetic field part 350 and the case 312, such
that the magnetic field part 350 may be separated due to an
external shock, and the like. Therefore, the shock absorbing member
321 having elastic force is additionally inserted between the
magnetic field part 350 and the separation prevention member 320 to
allow the separation prevention member 320 to be inserted between
the other end of the magnetic field part 350 and the case 312 and
then, elastically recover the shock absorbing member 321, thereby
more firmly fixing the magnetic field part 350.
[0157] Here, the shock absorbing member 321 may be formed of
various materials having elastic force such as rubber, silicon,
spring, and the like.
[0158] As set forth above, according to embodiments of the present
invention, a linear vibrator capable of maintaining a state in
which a fixed part is firmly fixed to a housing even in the case
that an external shock, and the like, is applied thereto.
[0159] 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.
* * * * *