Patent ID: 12189138

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, some exemplary embodiments of the present invention are described in detail with reference to the accompanying drawings.

FIG.1is a schematic plan view of a camera module according to an embodiment of the present invention,FIG.2is a sectional view of the camera module taken along line A-A ofFIG.1,FIGS.3and4are side views of the camera module according to the embodiment of the present invention, andFIG.5is an enlarged view of a part B ofFIG.2according to a first embodiment of the present invention.

As shown inFIG.1showing the schematic plan view andFIG.2showing the schematic side view of line A-A inFIG.1, the camera module according to the present invention includes a first Printed Circuit Board (hereinafter referred to as a PCB)10, a housing unit20, a holder module30, a second PCB40, a third PCB50, wire springs60, and buffer units100.

It is preferred that an image sensor11be mounted approximately on the central part of the first PCB10. Elements for driving the image sensor11may be disposed in the first PCB10or a plurality of terminal units for supplying power and outputting information from the image sensor11may be provided in the first PCB10.

The housing unit20is disposed over the first PCB10, and it forms the framework of the camera module. In accordance with an exemplary embodiment of the present invention, the housing unit20includes a first housing21, a second housing22, pairs of first and second permanent magnets23and24, and a plurality of yokes25.

The first housing21is a base and is disposed on the top of the first PCB10and spaced apart from the image sensor11at a specific interval. A filter member for filtering an image phase incident on the image sensor11may be further included in the first housing21as occasion demands.

The second housing22is disposed on the top of the first housing21and is configured to cover the first housing21. An opening is formed approximately at the center of the second housing22so that an image can be transferred to the image sensor11. The third PCB50is adhered and fixed to the upper lateral face of the second housing22using a fixing member to be described later, such as a double-sided tape or an adhesive, but not limited thereto. In some embodiments, however, an additional third housing, such as a casing or a shield can, may be provided, and the third PCB50may be fixed to the inside of the additional third housing using the fixing member according to a product design. If the third housing is provided, the third housing may press and support the third PCB50without an additional fixing member.

The first and the second permanent magnets23and24are interposed between the first and the second housings21and22and are configured to apply magnetic force to the holder module30. It is preferred that the first and the second permanent magnets23and24have the same size. Furthermore, the first and the second permanent magnets23and24and the yoke25may be disposed on the inside of the first and the second housing21and22, if possible, within a design tolerance limit.

Meanwhile, if the size of the first and the second permanent magnets23and24is increased, OIS driving is increased even by low current. If the first and the second permanent magnets23and24are configured to have a specific size, OIS driving is increased as current flowing into first and the second coils31ato31dand32adisposed at positions corresponding to the first and the second permanent magnets23and24is increased. Consequently, OIS driving becomes better according to an increase of the first and the second permanent magnets23and24, but it is preferred that the first and the second permanent magnets23and24have an optimized size within a design tolerance limit.

Each of the yokes25is interposed between each of the pairs of first and the second permanent magnets23and24. Furthermore, the central portion of the yoke25is configured to have a protruded shape so that the pair of first and second permanent magnets23and24may apply magnetic force to the internal space of the holder module30. It is preferred that the yoke25be configured to the same width as the pair of first and second permanent magnets23and24, the center of the yoke25be protruded in a specific size, and the pair of first and second permanent magnets23and24and the yoke25have an approximately ‘T’ shape.

The holder module30is spaced apart from the bottom surface of the inside of the housing unit20and is formed of an outer blade31and a bobbin32. The holder module30may perform a pendulum movement in the front/rear, left/right, and diagonal directions with it dangled from the wire springs60.

Spring members35and36are provided in the upper and lower parts of the outer blade31, respectively. The outer blade31is elastically supported by the spring member35so that the bobbin32is moved up and down.

As shown inFIG.1, a total of four first coils31ato31dare wound on the four outer faces of the outer blade31, respectively, and the central part of each of the four outer faces of the outer blade31on which the first coils31ato31dare wound is perforated without a coil. Each of the yokes25is disposed at a position corresponding to the perforated space unit, and thus the yoke25may be partially inserted into the space unit.

The second PCB40may be fixed to the bottom of the outer blade31using a fixing member33, such as a double-sided tape or an adhesive. The outer blade31is dangled from the plurality of wire springs60so that the outer blade31can move in the front/rear and left/right directions or in a diagonal line according to an interaction between the magnetic force of the first and the second permanent magnets22and23and the first coils31a, as indicated by an arrow ofFIG.2. Furthermore, the outer blade31is spaced apart from the bottom surface of the first housing21at a specific interval.

Furthermore, a plurality of spring through holes37may be provided in the outer blade31so that the wire springs60are connected to the second PCB40through the spring through holes37.

The bobbin32is disposed within the outer blade31so that it is movable up and down. At least one lens34is installed within the bobbin32. The second coil32ais wound on the outer circumferential face of the bobbin32. The second coil32aperforms an operation of raising up and lowering the bobbin32through an interaction with the magnetic force applied through the perforated spaces without the first coils31ato31dof the outer blade31through the yokes25. As the size of the yoke25increases, AF driving may become better, but may be changed according to an optimal design value. It is possible to automatically control the focus of an image transferred to the image sensor11through the raising action of the bobbin32.

The second PCB40is disposed at the bottom surface of the outer blade31as described above and is connected to the wire springs60so that it can supply a power source to the first and the second coils31ato31dand32a. This connection method may include any method if soldering or other conductive substances may be used. That is, the connection units w′ of the second PCB40are connected to the first coils31ato31d, respectively, and the second coil32a, as shown in,FIG.2. Thus, a power source supplied through the wire springs60is transferred to the first and the second coils31ato31dand32a, thus forming electromagnetic force.

Here, the second coil32amay be directly connected to the second PCB40, or the second coil32amay be connected to the lower spring36and the lower spring36may be then connected to the second PCB40as shown inFIG.2.

The third PCB50is fixed to the top of the second housing22using the fixing member, such as a double-sided tape or an adhesive member, as described above. A power source transferred through the terminal unit52of the third PCB50connected to the first PCB10is transferred to the second PCB40through the wire springs60connected to the second PCB40. This connection method may include any method if soldering or other conductive substances may be used.

The third PCB50may be provided to cover the walls of the first and the second housings21and22on one side, as shown inFIGS.3and4. Here, a window55may be formed in a surface of the third PCB50where the third PCB50faces the first and the second permanent magnets23and24and the yoke25in order to avoid interference therebetween.

The window55functions to prevent the third PCB50from being influenced by coupling portions because the first and the second permanent magnets23and24and the yoke25are directly adhered to a shield can70(described later) by using the fixing means, such as epoxy.

Meanwhile, a flexible PCB (FPCB), a PCB, or a rigid FPCB integration type (R-FPCB) may be used as each of the second PCB40and the third PCB50, but not limited thereto. Any board may be used as the second PCB40and the third PCB50if the board enables electrical connection.

Each of the wire springs60has both ends connected to the second and the third PCBs40and50. Here, one end of the wire spring60is connected to a pad51formed in the third PCB50as shown inFIG.5. A through hole53through which the wire spring60passes is formed at the center of the pad51. In this case, a connection method may include any method if soldering or other conductive substances may be used. Meanwhile, a Solder Register (SR) is provided around the pad51, thus protecting a surface of the third PCB50. The area of the pad51may be connected by opening the SR so that the area is conductive.

The wire spring60connected at the pad51as described above supplies the power source from the terminal unit52to the second PCB40, so that the first and the second coils31ato31dand32amay interact with the first and the second permanent magnets23and24.

Furthermore, the other end of the wire spring60is connected to the second PCB40, provided at the bottom surface of the outer blade31, through the spring through hole37formed in the outer blade31, as shown inFIG.2. As in the third PCB50, the other end of the wire spring60is connected at a pad (not shown) formed in the second PCB40, although not shown. A through hole (not shown) through which the wire spring60passes is formed at the center of the pad (not shown). In this case, a connection method may include any method if soldering or other conductive substances may be used. In this construction, the outer blade31may be dangled from the wire springs60and may be spaced apart front the bottom surface of the first housing21. In this case, the outer blade31performs a pendulum movement according to an interaction between the first coils31ato31dand the first and the second permanent magnets23and24. Accordingly, the vibration of the outer blade31due to hand shaking can be corrected by the interaction between the first coils31ato31dand the first and the second permanent magnets23and24. To this end, it is preferred that the wire spring60be made of metal material that has elasticity enough to withstand a shock and conductivity.

Meanwhile, as the thickness of the wire spring60is reduced, optical image stabilizer motility becomes better even at a low current, but may be changed according to an optimal design value. It is preferred that the thickness of the wire spring60be several μm to several hundreds of μm, more preferably, 1 to 100 μm.

Furthermore, it is preferred that the number of wire springs60be at least six. It is necessary to supply a power source of two polarities for auto-focusing control and a power source of four polarities for optical image stabilizer to the holder module30through connection between the wire springs60and the second and the third PCBs40and50.

In accordance with an exemplary embodiment of the present invention, it is preferred that four pairs of the wire springs60having the same length are disposed at the respective corners of the holder module30in order to keep the balance, as shown inFIGS.1and2.

Meanwhile, if an additional third housing, such as the shield can70, is included as shown inFIG.2, the windows55for covering the walls of the first and the second housings21and22are formed in the third PCB50in order to avoid the coupling parts because the first and the second permanent magnets23and24and the yokes25are fixed to the shield can70using epoxy, as described above.

If the shield can70is omitted, the first and the second permanent magnets23and24and the yokes25may be attached and fixed within the third PCB50. In some embodiments, the windows55may be formed in the third PCB50as described above, and the first and the second permanent magnets23and24and the yokes25may be inserted into the windows55. Reinforcement may be additionally performed outside the third PCB50using a shielding tape.

Buffer units100function to absorb a shock and repeated load applied to the wire springs60by surrounding connection units w where the wire springs60are connected to the third PCB50.

In accordance with an exemplary embodiment of the present invention, each of the buffer units100includes an injection hole110and a second wire spring through hole120.

The injection hole110is formed around the through hole53to which the wire spring60passing through the third PCB50is soldered. In accordance with the first embodiment of the present invention, the number of injection holes110may be one, as shown inFIG.5.

The second wire spring through hole120is provided in the second holder22. The second wire spring through hole120includes an upper opening121and a support hole122.

The upper opening121has a structure that is taped downwardly. It is preferred that the upper opening121have a conical funnel shape that is downwardly tapered, as shown inFIGS.5and6. The support hole122is formed in the same axis as the through hole53. It is preferred that the support hole122have a diameter equal to or greater than the through hole53.

It is preferred that the through hole53have a diameter slightly greater than the wire spring60. When the wire spring60is connected at the pad51formed in the third PCB50, a connection substance101, such as soldering or another conductive substance, flows out through the through hole53. The connection substance101may be connected to the wire spring60in the top and bottom surfaces of the third PCB50, as shown inFIGS.5and6.

It is preferred that the diameter of the support hole122be slightly greater than the diameter of the wire spring60. The diameter of the support hole122may be equal to or greater than the diameter of the through hole53. That is, the diameter of the support hole122may be designed so that the wire spring60does not interfere with the second holder22near the support hole122through contact with the second holder22.

A shown inFIG.5, an adhesive substance130is injected through the injection hole110and then filled in the internal space unit of the second wire spring through hole120. The adhesive substance130may further cover the connection unit w of the third PCB50. The adhesive substance130filled in the second wire spring through hole120may absorb a shock and load transferred to the connection unit w of the wire spring60and the third PCB50and may prevent the wire spring60from being shaken within the upper opening121of the second wire spring through hole120. Epoxy may be used as the adhesive substance130, but not limited thereto. Any material that may support elasticity through adhesion may be used as the adhesive substance130.

In accordance with a second embodiment of the present invention, the buffer unit100may be configured like in the first embodiment, but a pair of the injection holes110may be provided in the buffer unit100. In this case, the pair of the injection holes110may be disposed on both sides of the through hole53or may be symmetrically disposed each other, but not limited to the positions.

In this case, the adhesive substance130injected through the pair of injection holes110may fully cover not only the inside of the upper opening121of the second wire spring through hole120, but also the connection unit w formed on the top of the third PCB50, as shown inFIG.4.

In accordance with this construction, there are additional effects that the connection unit w of the third PCB50exposed at the top can be prevented from being damaged by an external shock and the connection unit w is insulated.

Meanwhile, in a common assembly process, after the bobbin32and the outer blade31are combined, the second housing22, the second and the third PCBs40and50, and the wire springs60are coupled, the bobbin32including a lens barrel is combined, the first housing21is connected, and the first housing21is then mounted on the first PCB10by using a jig. Alternatively, the permanent magnets and the yokes may be combined before the first housing21is connected. The sequence of the above assembly may be changed as occasion demands. In other words, the assembly may be directly performed in equipment without a jig. In this process, although force for inserting and combining the bobbin32including the lens barrel is excessively great and the connection units w are adversely affected by the excessive force, the buffer units100may absorb the excessive force.

In other words, the transformation energy of the buffer unit100absorbs load that is generated in the wire spring60around the connection unit w of the wire spring60and the third PCB50and thus pulled in the direction of gravity and load generated when the wire spring60is shaken left and right, as shown inFIGS.2,5, and6.

Accordingly, a problem that the connection task has to be performed again or that a damaged product cannot be used because the connection unit w is broken during the assembly process can be avoided. It is thus possible to produce a reliable camera module.

Surface processing units1100are formed at both ends of each of the wire springs60, thereby improving a coupling property between the second and the third PCBs40and50and the wire spring60.

In accordance with third and fourth embodiments of the present invention, each of the surface processing units1100may be coarsely formed by polishing a surface of the wire spring60as shown inFIG.5or may be formed by partially removing a coating film formed on the surface of the wire spring60using a method, such as corrosion, as shown inFIG.6. If the surface processing unit1100is formed as described above, bonding force between lead and the wire spring60can be improved when a soldering process using lead as the connection substance is performed.

Meanwhile, a second wire through hole120is provided in the second holder22, as shown inFIG.7. The second wire through hole120includes an upper opening121and a wire spring support hole122.

The upper opening121has a conical funnel shape that is downwardly tapered. The wire spring support hole122is formed on the same axis as the first wire through hole53. It is preferred that the wire spring support hole122have a diameter equal to or greater than the first wire through hole53.

Here, the diameter of the first wire through hole53may be slightly greater than the diameter of the wire spring60. The diameter of the first wire through hole53may be designed so that, when the wire spring60is connected to the pad51formed in the third PCB50, a connection substance, such as soldering or other conductive substances, flows down through the first wire through hole53and the connection substance is then connected and fixed to the wire spring60on the top and bottom surfaces of the third PCB50.

Furthermore, the diameter of the wire spring support hole122may be slightly greater than the diameter of the wire spring60. The wire spring support hole122may have a diameter equal to or greater than the first wire through hole53. That is, the diameter of the wire spring support hole122may be designed so that the wire spring60does not interfere with the second holder22near the support hole122through contact with the second holder22.

In accordance with this construction, the wire springs60can be combined with the second and the third PCBs40and50more firmly. Furthermore, a reliability problem (e.g., the separation or disconnection of the wire springs60that may occur owing to external force, such as a drop) can be improved.

That is, the surface processing units1100increase the frictional force of the connection units w and w′ between the wire springs60and the second and the third PCBs40and50, so that the surface processing units1100withstand load in the direction of gravity applied to the wire springs60at the connection units w and w′ and load that may occur when the wire springs60are shaken left and right, as shown inFIGS.2,8, and9.

Accordingly, a problem that the connection task has to be performed again or that a damaged product cannot be used because the connection unit w is broken during the assembly process can be avoided. It is thus possible to produce a more reliable camera module.

Meanwhile, the surface processing unit1100may be formed only at the end of one side of the wire spring60, although not shown. That is, the surface processing unit1100may be formed only at the connection unit w with the third PCB50to which heavy load is repeatedly applied or at the connection unit w′ with the second PCB40.

Meanwhile, the shield can70may be further provided to have a through hole at a position corresponding to the lens module30near the connection units w of the third PCB50and the wire springs60and configured to surround the housing units21and22. In this case, the third PCB50may be attached and fixed to the inside of the shield can70as described above. Meanwhile, the shield can70is not a requisite and may be omitted according to constructions of the housing units21and22.

Meanwhile, as shown inFIG.2, in order to fix the shield can70to the first housing21, a hook unit80may be provided at each of the four faces or at one or more faces. The position of the hook unit80may be within a range in which the center or corner design is allowed. The number of hook units80may be one or more.

The hook unit80may include a hook81protruded into the first housing21and a hook hole82formed to penetrate the shield can70facing the hook81, and an opposite construction is possible as an occasion demands.

The embodiments of the present invention described above and shown in the drawings should not be construed as limiting the technical spirit of the present invention. The scope of the present invention is restricted by only the claims, and a person having ordinary skill in the art to which the present invention pertains may improve and modify the technical spirit of the present invention in various forms. Accordingly, the modifications and modifications will fall within the scope of the present invention as long as they are evident to those skilled in the art.