Linear vibration motor

Disclosed herein is a linear vibration motor including: a stator part; a vibrator part received in the stator part to thereby linearly vibrate; an elastic member having one end fixedly coupled to the stator part and the other end fixedly coupled to the vibrator part, wherein the vibrator part includes a printed circuit board having one end fixedly coupled to the stator part and the other end fixedly coupled to the vibrator part to thereby linearly vibrate integrally with the vibrator part.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 10-2011-0100256, filed on Sep. 30, 2011, entitled “Linear Vibration Motor”, which is hereby incorporated by reference in its entirety into this application.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a linear vibration motor.

2. Description of the Related Art

A general vibration motor, which is a component converting electrical energy into mechanical vibration using a principle of generating electromagnetic force, is mounted in a mobile communication terminal, a portable terminal, and the like, to be used for silently notifying a user of call reception.

Currently, a linear vibration motor has been generally used as the vibration motor. The linear vibration motor is generally disposed at an edge portion of a device and generates vibration in a direction perpendicular to an object receiving the vibration.

A general linear vibration motor includes a stator part, a vibrator part, and an elastic member coupled to the stator part and elastically supporting the vibrator part.

In addition, the stator part includes a case, a bracket, and a magnet, and the vibrator part includes a coil a weight body, and a printed circuit board.

In the internal structure of the linear vibration motor according to the prior art described above, the printed circuit has one end electrically connected to the coil and the other end coupled to the bracket configuring the stator part, such that it linearly moves integrally with the vibrator part.

However, a coupling surface of the printed circuit board coupled to the bracket may be separated from the bracket due to linear movement for a long period of time or external impact.

SUMMARY OF THE INVENTION

The present invention has been made in an effort to provide a linear vibration motor including a case provided with a coupling part fixing a portion of a printed circuit board in order to increase adhesion between the printed circuit board and a stator part and the printed circuit board coupled to the case.

According a preferred embodiment of the present invention, there is provided a linear vibration motor including: a stator part; a vibrator part received in the stator part to thereby linearly vibrate; an elastic member having one end fixedly coupled to the stator part and the other end fixedly coupled to the vibrator part, wherein the vibrator part includes a printed circuit board having one end fixedly coupled to the stator part and the other end fixedly coupled to the vibrator part to thereby linearly vibrate integrally with the vibrator part.

The stator part may include: a case having an inner space formed therein so as to receive the vibrator part therein; a bracket coupled to a lower portion of the case to thereby compart the inner space of the case; and a magnet selectively coupled to the case or the bracket, wherein the case includes a coupling part to which the printed circuit board is partially coupled.

The printed circuit board may include: a power supplying part fixedly coupled to the bracket and provided with a power connection pad; a mounting part extended from the power supplying part and coupled to the coupling part of the case; an elastic part extended from the mounting part in a spiral direction so as to have elastic force; and a power applying part formed at one end of the elastic part and electrically coupled to the vibrator part to thereby apply external power to the vibrator part.

The coupling part may include: a penetration groove formed so that the mounting part of the printed circuit board is fitting-coupled thereinto in a width direction; and support parts formed to be protruded from both sides of the penetration groove toward the bracket and each including catching jaws formed in order to support the mounting part of the printed circuit board.

The mounting part may include predetermined grooves formed inwardly in the width direction at both sides thereof so as to face the catching jaws.

The magnet may include: a first magnet coupled to an upper surface of an inner side of the case; and a second magnet coupled to an upper surface of an inner side of the bracket.

The stator part may further include a plate yoke coupled to an upper surface of an inner side of the case and coupled to a lower portion of the magnet.

The stator part may further include a plate yoke coupled to an upper surface of an inner side of the bracket and coupled to an upper portion of the magnet.

The stator part may further include a plate yoke selectively positioned on the first and second magnets.

The vibrator part may further include: a coil electrically connected to the other end of the printed circuit board; a weight body coupled to an outer peripheral surface of the coil; and a cylindrical yoke coupled between the weight body and the coil to thereby increase magnetic force of the magnet, and the other end of the elastic member and an upper portion of the yoke may be fixedly coupled to each other.

The elastic member may include: an upper plate part fixedly coupled to an upper surface of an inner side of the stator part; a lower plate part fixedly coupled to an upper portion of the vibrator part; and a plurality of bending parts connecting the upper and lower plate parts to each other and generating elastic force, and elastically support linear movement of the vibrator part.

The linear vibration motor may further include a damper coupled to a lower portion of the power supplying part of the printed circuit board so as to face the stator part to thereby prevent noise and impact from being generated at the time of contact between the printed circuit board and the stator part.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Various objects, advantages and features of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings. In the specification, in adding reference numerals to components throughout the drawings, it is to be noted that like reference numerals designate like components even though components are shown in different drawings. Further, terms used in the specification, ‘first’, ‘second’, etc. can be used to describe various components, but the components are not to be construed as being limited to the terms. The terms are only used to differentiate one component from other components. Further, when it is determined that the detailed description of the known art related to the present invention may obscure the gist of the present invention, the detailed description thereof will be omitted.

FIG. 1is an exploded perspective view showing a linear vibration motor according to a preferred embodiment of the present invention; andFIG. 2is a cross-sectional view showing a coupled state of the linear vibration motor shown inFIG. 1. As shown, the linear vibration motor according to the preferred embodiment of the present invention is configured to include a stator part, a vibrator part, and an elastic member elastically supporting linear vibration of the vibrator part.

More specifically, the stator part includes a case100, a bracket110, a magnet130, and a plate yoke150, and the vibrator part includes a coil120, a weight body160, a yoke140, and a printed circuit board180.

The case100has an inner space formed therein so as to receive the linearly moving vibrator part therein, and the bracket110is coupled to a lower portion of the case100to thereby compart the inner space of the case100.

In addition, the case100includes a coupling part101formed at a lower portion thereof, wherein the coupling part101is coupled to a portion of the printed circuit board180to be described below.

Further, the magnet130may be selectively coupled to any one of the case100and the bracket110. According to the preferred embodiment of the present invention, the magnet130is formed in plural as shown inFIGS. 1 and 3.

However, the number of magnets according to the preferred embodiment of the present invention is not limited thereto. That is, a single magnet130may be coupled to only an upper surface of an inner side of the case100or only an upper surface of an inner side of the bracket110.

More specifically, the magnet130according to the preferred embodiment of the present invention includes a first magnet131coupled to the upper surface of the inner side of the case100and a second magnet132coupled to the upper surface of the inner side of the bracket110.

In addition, the first and second magnets131and132may be disposed so that portions thereof having same polarity face to each other in order to increase magnetic force.

For example, when a lower portion131bof the first magnet131is an S pole and an upper portion131athereof is an N pole, a lower portion132bof the second magnet132becomes an N pole and an upper portion132athereof becomes an S pole.

Further, a sequence of polarities is not limited to the contents described in the present invention but may be reverse.

Therefore, the first and second magnets131and132are spaced apart from each other by a predetermined interval a to thereby form a magnetic field in a vertical direction.

In addition, the plate yoke150may be selectively coupled to the first and second magnets131and132in order to collect the magnetic field. In the case of the linear vibration motor according to the preferred embodiment of the present invention, the plate yoke150is coupled to the upper portion132aof the second magnet132as shown.

As shown inFIGS. 2 and 3, the coil120may be formed to have a cylindrical shape in which it is provided with a hollow part121capable of receiving the first and second magnets131and132therein in order to generate electromagnetic force through electromagnetic induction along outer peripheral surfaces of the first and second magnets131and132.

In addition, the coil120is electrically connected to the other end of the printed circuit board180to thereby form a magnetic field by power applied from the printed circuit board180.

The yoke140is provided with a reception groove141coupled to an outer peripheral surface of the coil120and has an upper surface142coupled to an upper portion of the weight body160to be described below.

The weight body160is provided with a hollow part161for receiving the coil120therein, and the yoke140coupled to the outer peripheral surface of the coil120is coupled to an inner peripheral surface of the hollow hole161of the weight body160and the upper portion of the weight body160.

In addition, the weight body160is fixedly coupled to the other end of the printed circuit board180to thereby linearly vibrate integrally with the printed circuit board180.

The printed circuit board180includes a power supplying part181, a mounting part183, and an elastic part185, and a power applying part187.

More specifically, the power supplying part181is fixedly coupled to an upper portion of the bracket110and is provided with a power connection pad182for receiving external power from a set component.

In addition, the mounting part183is extended from the power supplying part181and is coupled to the coupling part101of the case100configuring the stator part.

More specifically, the mounting part183includes predetermined grooves184formed inwardly in a width direction at both sides thereof in order to be coupled to the coupling part101of the case100to be described below.

In addition, the elastic part185is extended from the mounting part183in a spiral direction so as to have elastic force.

Further, the power applying part187is formed at one end of the elastic part185extended in the spiral direction and has an upper surface coupled to the coil120of the vibrator part to thereby apply the external power to the coil120.

In addition, as shown inFIG. 3, which is a schematic view showing a coupled relationship between a weight body and a printed circuit board that configure a vibrator part according to the preferred embodiment of the present invention, the power applying part187is partially fixed to a lower portion of the weight body160to thereby linearly move integrally with the weight body160.

Therefore, the printed circuit board180is a flexible printed circuit (FPC) board having elastic force so that it has one end fixedly coupled to the bracket110configuring the stator part and the other end coupled to the coil120and the weight body160configuring the vibrator part to thereby linearly move integrally with the vibrator part, and may have a spring shape or a coil spring shape extended in the spiral direction.

The elastic member190, which has a leaf spring shape, includes an upper plate part191, a lower plate part193, and a plurality of bending parts195and is coupled to the yoke140and the case100.

More specifically, the upper plate part191is fixedly coupled to the upper surface of the inner side of the case100.

In addition, the lower plate part193is fixedly coupled to an upper portion of the yoke140configuring the stator part.

Further, the plurality of bending parts195serve to drive the elastic member190. More specifically, in order to generate elastic force, each of the plurality of bending parts195has one end connected to the upper plate part191and the other end connected to the lower plate part193, such that it is extended from the upper plate part191to the lower plate part193in the spiral direction.

In addition, the upper plate part191and the lower plate part193of the elastic member190are provided with a hollow part196in which the first and second magnets131and132are disposed in order to prevent contact with outer peripheral surfaces of the first magnet131coupled to the upper surface of the inner side of the case100and the second magnet132coupled to the upper surface of the inner side of the bracket110while they elastically support the vibrator part.

Therefore, the elastic member190may be formed to have a spring shape or a coil spring shape extending in the spiral direction.

The damper170is selectively coupled to the upper surface of the inner side of the printed circuit board180or the bracket110in order to prevent noise and impact from being generated at the time of contact between the printed circuit board180and the bracket110due to excessive linear vibration of the vibrator part.

More specifically, according to the preferred embodiment of the present invention, the damper170is coupled to a lower portion of the power supplying part181of the printed circuit board180so as to face the bracket110.

In addition, the damper170is provided with a hollow part171so that the first magnet131fixedly coupled to the upper surface of the inner side of the case and the second magnet132fixedly coupled to the upper surface of the inner side of the bracket110are disposed therein.

FIG. 4is a schematic perspective view of a case configuring a stator part according to the preferred embodiment of the present invention. As shown, the coupling part101of the case100is provided with a penetration groove102so that a portion of the printed circuit board180is connected to an external set component.

In addition, in order to support the printed circuit board180coupled to the penetration groove102of the coupling part101, both sides of the penetration grooves102are provided with support parts105each including a catching jaw103and protruded toward the bracket110.

FIG. 5is a schematic view showing a coupled relationship between the printed circuit board and a case according to the preferred embodiment of the present invention; andFIG. 6is a schematic cross-sectional view showing a coupled state between the printed circuit board and the case shown inFIG. 5. As shown, the printed circuit board180has a thickness T1smaller than a height T2of the support part configuring the mounting part101of the case100.

In addition, the printed circuit board180has a width W1equal to or slightly smaller than a width W2of the penetration groove181of the case180.

Therefore, when the mounting part183of the printed circuit board180is press-fitted so that the catching jaws103of the case100and the grooves184formed at both sides of the mounting part183of the printed circuit board180are positioned to face each other, the mounting part183of the printed circuit board180made of an elastic material is naturally press-fitted and fitting-coupled into the coupling part101of the case100.

Therefore, since the support parts105of the case100support the mounting part183of the printed circuit board180in a width direction and the catching jaws103support a rear side of the mounting part183, even though the printed circuit board180linearly vibrates integrally with the vibrator part, it is possible to prevent the printed circuit board180from being detached from the case100.

In addition, even though the printed circuit board180coupled integrally with the vibrator part is partially damaged due to linear vibration for a long period of time or electrical connection between the printed circuit board180and the coil120is short-circuited, the damaged printed circuit board is easily detached from the coupling part121of the case100, such that it may be replaced with a new printed circuit board.

According to the preferred embodiment of the present invention, it is possible to increase fixing force between the printed circuit board that linearly moves integrally with the vibrator part and the stator part.

In addition, a movable displacement of the printed circuit board that linearly moves is maintained to be constant, thereby making it possible to minimize a change in vibration force and frequency of the vibrator part.

Further, an insulation defect between the printed circuit board and the stator part is prevented, thereby making it possible to increase a yield of a product.

Furthermore, even though the printed circuit board coupled integrally with the vibrator part is partially damaged due to linear vibration for a long period of time or electrical connection between the printed circuit board and the coil is short-circuited, the damaged printed circuit board is easily detached from the stator part, such that it may be replaced with a new printed circuit board.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, they are for specifically explaining the present invention and thus a linear vibration motor according to the present invention is not limited thereto, but those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.