Intermediate movable member of camera actuator and camera actuator including same

Abstract

The present invention discloses an intermediate moving member of a camera actuator and a camera actuator including the same. The intermediate moving member of the camera actuator according to an embodiment of the present invention includes at least two or more ball guide rail portions. The ball guide rail portions respectively include: a first-direction ball guide rail formed in such a manner that a guide rail made of a metal material is exposed to the upper part of the intermediate moving member; and a second-direction ball guide rail formed in such a manner that a guide rail made of a metal material is exposed to the lower part of the intermediate moving member. The first-direction ball guide rail and the second-direction ball guide rail are adjacent to each other and are separated in such a manner that they do not coincide or overlap with each other when observed in the optical axis direction, and at least a part of them overlaps when observed in the first direction. In this way, when the camera actuator is configured such that the optical unit can perform planar movement in two axial directions orthogonal to the optical axis, the height of the ball guide rail portion formed in the intermediate moving member is significantly reduced, thereby enabling miniaturization and ultra-thinness of the camera actuator.

Description

Technical Field

[0001] The present invention relates to an intermediate movable member of a camera actuator, and to an intermediate movable member of a camera actuator mounted in a camera actuator of a camera module having a shake correction function and a camera actuator including the intermediate movable member. Background Art

[0002] Recently, portable terminals such as smart phones (hereinafter referred to as "mobile phones") have followed the progress of their technology, deviated from the existing simple telephone function, and evolved into media convergence capable of performing various functions such as music, movies, TV, games, etc. One of the elements leading the development of media convergence is the camera lens module.

[0003] The camera lens module mounted on a mobile phone has changed to a structure having various additional functions such as an auto focus function and an optical zoom function in order to meet the recent trend centered on high pixels and high performance in accordance with user needs. In particular, recently, attempts have been made from various angles to implement an optical image stabilizer technology within the size of a mobile phone.

[0004] The optical image stabilizer technology refers to a technology that automatically controls the focus of the lens assembly constituting the camera module to move in a direction resistant to shake, and maintains the resolution of the captured image at the best. In order to implement such an optical image stabilizer technology, a shake correction actuator is mounted in a camera module applicable to a mobile phone, a video camera, etc.

[0005] As a shake correction actuator, a VCM (Voice Coil Motor) type using the interaction between a magnetic field and an electric field is well known. The VCM type is generally configured such that a magnetic circuit is formed by a coil and a magnet arranged opposite to each other, and an optical unit on which a lens is mounted is moved in a two-axis direction in a plane perpendicular to the optical axis by the magnetic force generated by the magnetic circuit to cope with shake.

[0006] The basic principle of the optical image stabilizer function is to move the optical unit on which the lens is mounted in the relative direction of the driving displacement generated by shake, and to make the optical axis and the incident path of light received by the image sensor coincide. For this purpose, a structure is required that guides the optical unit on which the lens is mounted to be able to perform a planar motion in a two-axis direction in a plane perpendicular to the optical axis.

[0007] Among existing camera modules, one of the structures that guides the optical unit to move in a plane perpendicular to the optical axis is the Middle guide. In the Middle guide, balls are usually arranged as a medium between the optical unit and the housing that houses the optical unit in such a way that the optical unit can move in a plane relative to the housing in two axial directions.

[0008] Figure 1 FIG. 4 is an exploded schematic view of an existing camera actuator to which the Middle guide is applied. Figure 2 FIG. Figure 1 is a diagram showing a combined cross-sectional view of the camera actuator shown in FIG.

[0009] Referring to Figure 1 and Figure 2 , the Middle guide 70 applied to the existing camera actuator is mounted on the bottom of the housing 60 in such a way that it can move linearly in a first direction orthogonal to the optical axis relative to the housing 60, and the optical unit 80 that constitutes the optical system is formed on the Middle guide 70 in such a way that it can move linearly in a second direction orthogonal to the first direction.

[0010] A plurality of pairs of corresponding first-direction ball guides 74 are formed between the housing 60 and the Middle guide 70 in such a way that the Middle guide 70 can move linearly in the first direction relative to the housing 60, and a plurality of pairs of corresponding second-direction ball guides 72 are formed between the Middle guide 70 and the optical unit 80 in such a way that the optical unit 80 can move linearly in the second direction relative to the Middle guide 70.

[0011] Ball grooves (reference numerals omitted) are formed in the plurality of first-direction ball guides 74 provided in a paired manner on the lower surfaces of the housing 60 and the Middle guide 70, and ball grooves (reference numerals omitted) are formed in the plurality of second-direction ball guides 72 provided in a paired manner between the Middle guide 70 and the optical unit 80. And, a ball B is interposed between each of the first-direction ball guide 74 and the second-direction ball guide 72.

[0012] When the Middle guide 70 moves synchronously in the first direction relative to the housing 60 or the optical unit 80 moves synchronously in the second direction relative to the Middle guide 70, the ball B rolls along the ball grooves of the corresponding ball guides 72 or 74, while maintaining a stable linear motion, and also plays a role in suppressing the horizontal rotation of the optical unit 80 relative to the housing 60 between the corresponding ball guides 72 or 74.

[0013] In the existing camera actuator of this structure, at least one of the driving forces in the first direction generated by the first-direction magnetic circuit (not shown) and the driving force in the second direction generated by the second-direction magnetic circuit (not shown) is used to displace the optical unit 80 in the housing 60 in the first direction or the second direction, or in the first and second directions, to cope with shake.

[0014] However, in the existing structure such as Figure 1 and Figure 2 where the optical axis directions of the first-direction ball guide 74 and the second-direction ball guide 72 formed in the intermediate guide 70 overlap each other, the balls B between the corresponding first-direction ball guide 74 and second-direction ball guide 72 can only be arranged coaxially in the optical axis direction. Therefore, there is a limit in reducing the overall height of the camera module.

[0015] That is, the existing structure such as Figure 1 and Figure 2 has the disadvantage that it is difficult to implement the product in an ultra-thin and compact size in terms of structure, and it is also pointed out that in a drop test where an impact is directly applied to the ball guide or in an actual drop, problems such as reliability and durability occur, such as micro-indentations (ball indentations) being easily formed on the ball guides due to the balls B made of ceramic material applying impact to the resin ball guides 72 and 74.

[0016] In addition, since the ball guides 72 and 74 are arranged coaxially, the proportion of the components related to shake correction in the overall structure is relatively large, and accordingly, the size of the magnet that constitutes the magnetic circuit in a limited space can only be reduced. Therefore, in the trend of increasing weight of optical components with the increasing market demand for cameras with higher performance expectations, there is a problem of difficulty in ensuring sufficient driving force.

[0017] Prior Art Documents

[0018] Patent Document: Korean Patent Publication No. 10-2018-0116965 (Publication Date: October 26, 2018) Summary of the Invention

[0019] Technical Problem to be Solved

[0020] The technical problem to be solved by the present invention is to provide an intermediate moving member of a camera actuator and a camera actuator including the intermediate moving member, which can reduce the overall height by improving the structure of the intermediate guide (Middle guide), thereby enabling the implementation of an ultra-thin and compact product (camera module).

[0021] Another technical problem to be solved by the present invention is to provide an intermediate movable part of a camera actuator and a camera actuator including the intermediate movable part, which can fundamentally solve the problem of micro-depression (ball indentation) of the ball guide rail, thereby further improving the durability and reliability of the product.

[0022] Another technical problem to be solved by the present invention is to provide an intermediate movable part of a camera actuator and a camera actuator including the intermediate movable part. As the market demand for cameras with higher and higher performance is expected and the weight of optical components is increasing, the camera actuator can achieve miniaturization and ultra-thinness of the product and ensure sufficient driving force.

[0023] Means of solving the problem

[0024] As a solution to the problem, according to one aspect of the present invention, there is provided an intermediate movable part of a camera actuator including at least two ball guide parts, the ball guide parts respectively including: a first direction ball guide formed in a manner that a guide surface of a metal material is exposed toward an upper portion of the intermediate movable part; and a second direction ball guide formed in a manner that a guide surface of a metal material is exposed toward a lower portion of the intermediate movable part, the first direction ball guide and the second direction ball guide are adjacent to each other, and are separated in a manner that they do not overlap or overlap each other when viewed in the direction of the optical axis, and at least partially overlap when viewed in the first direction.

[0025] The intermediate movable member may be composed of an injection molded part made of synthetic resin constituting the outer shape of the intermediate movable member and an insert made of metal inserted into the injection molded part.

[0026] In addition, the first direction ball guide can be composed of a first ball guide forming part and a first track piece, the first ball guide forming part is formed on the injection molded part, the first track piece is formed on the insert, and has the guide surface exposed to the upper part of the first ball guide forming part after insertion molding, and the second direction ball guide can be composed of a second ball guide forming part and a second track piece, the second ball guide forming part is integrated with the first ball guide forming part, the second track piece is formed on the insert, and has the guide surface exposed to the lower part of the second ball guide forming part at a position offset from the first track piece after insertion molding.

[0027] In addition, a first pitch correction hole partially exposing the first rail piece may be formed on the lower surface of the first ball guide rail forming portion, and a second pitch correction hole partially exposing the second rail piece may be formed on the upper surface of the second ball guide rail forming portion.

[0028] Preferably, the insert may be a non-magnetic body.

[0029] As a solution to the problem, according to another aspect of the present invention, there is provided a camera actuator including: an intermediate movable member according to the foregoing aspect; an upper movable member mounted on the intermediate movable member so as to be capable of synchronously moving in a first direction relative to the intermediate movable member; and a lower movable member supporting the intermediate movable member from below so that the intermediate movable member carrying the upper movable member can synchronously move in a second direction.

[0030] Preferably, the camera actuator may further include a base housing the upper movable member, the intermediate movable member, and the lower movable member, and the lower movable member is housed in the base so as to be capable of synchronously moving in the optical axis direction in a state where the upper movable member and the intermediate movable member are carried.

[0031] At this time, a first optical axis drive coil and a second optical axis drive coil may be arranged on a first side surface and a second side surface adjacent to each other of the base, and a first optical axis drive magnet and a second optical axis drive magnet corresponding to the first optical axis drive coil and the second optical axis drive coil respectively are mounted on the lower movable member.

[0032] In addition, a first planar drive coil and a second planar drive coil may be respectively arranged on a third side surface and a fourth side surface of the base facing the first side surface and the second side surface respectively, and a first planar drive magnet and a second planar drive magnet corresponding to the first planar drive coil and the second planar drive coil respectively are provided on the upper movable member.

[0033] In addition, a first-direction upper ball guide rail corresponding to each of the first-direction ball guide rails of the intermediate movable member in a symmetric manner may be formed on the upper movable member, a second-direction lower ball guide rail corresponding to each of the second-direction ball guide rails of the intermediate movable member in a symmetric manner may be formed on the lower movable member, and a ball is interposed between the corresponding first-direction ball guide rail and the first-direction upper ball guide rail, and between the second-direction ball guide rail and the second-direction lower ball guide rail respectively.

[0034] Preferably, the upper movable member may be composed of an upper injection molded part made of a synthetic resin material forming the outer shape of the upper movable member and upper insert parts made of a metal material inserted into the upper injection molded part and decomposed into a plurality of parts.

[0035] In addition, the first-direction upper ball guide rail may be composed of an upper ball guide rail forming part and upper rail pieces. The upper ball guide rail forming part is formed on the upper injection molded part, and the upper rail pieces are formed at both ends of the first upper insert part and the second upper insert part formed opposite to each other in the upper insert parts, and have a guide surface exposed to the lower part of the upper ball guide rail forming part after insert molding.

[0036] Among them, a first planar drive yoke that generates an attractive force with the first planar drive magnet can be formed in one of the first upper insert and the second upper insert, and a third upper insert adjacent to the first upper insert and the second upper insert constitutes a second planar drive yoke that generates an attractive force with the second planar drive magnet.

[0037] In addition, an upper pitch correction hole for locally exposing the upper rail piece can be formed on the upper surface of the upper ball guide forming portion.

[0038] In addition, some or all of the upper inserts can be made of a magnetic material.

[0039] In addition, the lower movable member can be composed of a lower injection molded part made of a synthetic resin material forming the outer shape of the lower movable member and a lower insert made of a metal material inserted into the lower injection molded part.

[0040] Among them, the second-direction lower ball guide can be composed of a lower ball guide forming portion and a lower rail piece. The lower ball guide forming portion is formed on the lower injection molded part, and the lower rail piece is formed on the lower insert and has a guide surface that is exposed above the lower ball guide forming portion after insert molding.

[0041] At this time, a pair of the second-direction lower ball guides can be configured as V-guides, and the other pair can be configured in the form of U-guides.

[0042] In addition, a lower pitch correction hole for locally exposing the lower rail piece can be formed on the lower surface of the lower ball guide forming portion.

[0043] And, a first optical axis drive yoke that generates an attractive force with the first optical axis drive magnet can be formed on one side edge of the lower insert, and a second optical axis drive yoke that generates an attractive force with the second optical axis drive magnet can be formed on the other side edge of the lower insert.

[0044] At this time, some or all of the lower insert can be made of a magnetic material.

[0045] Advantages of the Invention

[0046] For the intermediate movable member of the camera actuator according to the present invention and the camera actuator including the intermediate movable member, by applying an intermediate movable guide having a unique structure (when observed in the planar (Z-axis direction), two balls (the balls respectively in contact with the first ball guide and the second ball guide) do not coincide or overlap with each other, and when observed in the first direction (X-axis direction), a part of the two balls overlaps with each other), the product can be made thinner and more compact as a whole.

[0047] In addition, by applying a movable member with a structure in which an insert made of a metal material is inserted into an injection molded part, the rigidity of the overall product is increased, which is also beneficial to the durability of the product. By forming a rail piece in contact with the ball from a part of the insert made of a metal material, it has the advantage of being able to significantly solve the problem of existing micro-indentations (ball indentations) during a drop test or actual fall.

[0048] Furthermore, due to the unique structure of the intermediate movable member, the height of the overall movable member is reduced. Correspondingly, the proportion of the components for correcting jitter in a limited space is decreased, so that the size of the magnet can be relatively increased. Therefore, in the trend of increasing component weight of optical components with the increasing market demand for cameras with higher and higher expected performance, sufficient driving force can be ensured without increasing the size of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is an exploded schematic view of an existing camera actuator to which an intermediate guide is applied.

[0050] Figure 2 is Figure 1 a combined sectional view of the camera actuator shown.

[0051] Figure 3 is a schematic view of a middle guide of a camera actuator according to an aspect of the present invention.

[0052] Figure 4 is Figure 3 a schematic view of an insert in the middle guide built-in shown.

[0053] Figure 5 is viewed from the bottom surface Figure 3 a schematic view of the middle guide shown.

[0054] Figure 6 is viewed from the first direction Figure 3 a perspective view of the middle guide shown.

[0055] Figure 7 is viewed from the second direction Figure 3 a perspective view of the middle guide shown.

[0056] Figure 8 is a reference diagram showing the insert molding process of a ball guide.

[0057] Figure 9 is an exploded schematic view showing the decomposition of a camera actuator according to another aspect of the present invention.

[0058] Figure 10 is Figure 9 an internal perspective view of the upper movable member shown.

[0059] Figure 11 Viewed from the bottom surface Figure 9 is a schematic view of the upper movable member shown.

[0060] Figure 12 is Figure 9 a schematic view of the lower movable member shown.

[0061] Figure 13 is a schematic view of the lower insert member of the lower movable member inserted into Figure 12 .

[0062] Figure 14 Viewed from the bottom surface Figure 12 is a schematic view of the lower movable member shown. Detailed implementation mode

[0063] Hereinafter, preferred embodiments of the present invention will be described in detail.

[0064] The terms used in the specification are only for explaining specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions as long as there is no clear other meaning in the context.

[0065] It should be understood that terms such as "including" or "having" in this specification indicate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and do not preclude the existence or additional possibility of one or more other features or numbers, steps, actions, components, parts, or combinations thereof in advance.

[0066] In addition, terms such as first, second, etc. can be used to explain various components, but the above components should not be limited to the above terms. The above terms are only for the purpose of distinguishing one component from other components.

[0067] Furthermore, terms such as "... part", "... unit", "... module", etc. described in the specification indicate units that process at least one function or action, which can be implemented by hardware or software, or a combination of hardware and software.

[0068] The embodiments of the following specification are applicable to the "camera" of a "portable user device", and the mobile terminal refers to a portable user device. However, this is just a conventional term, and these embodiments can be applicable to various devices or fields such as mobile phones, palm-sized personal computers (PCs), personal communication systems (PCS), personal digital assistants (PDAs), hand-held PCs (HPCs), smartphones, wireless LAN (Local Area Network) terminals, laptops, netbooks, tablet personal computers, game consoles other than mobile phones, VR devices (Virtual Reality), vehicles, etc.

[0069] Therefore, the term "portable user device" should not be used to limit the applicability of these embodiments to a specific type of device.

[0070] When explaining the present invention with reference to the accompanying drawings, the same reference numerals are given to the same structural elements and their descriptions are omitted. Also, when it is determined that the specific description of a well-known function or structural element relevant to explaining the present invention makes the gist of the present invention unnecessarily obscure, its detailed description can be omitted.

[0071] When explaining the present invention below, for the sake of convenience, a three-axis direction coordinate system is applied for the explanation. In the accompanying drawings, the Z-axis is the height direction of the camera actuator, which refers to the direction through which the light introduced from the outside passes, i.e., the optical axis direction, the X-axis (the first direction) is the direction perpendicular to the above-mentioned Z-axis as the optical axis direction. And the Y-axis (the second direction) is the direction orthogonal to the above-mentioned X-axis on the plane perpendicular to the Z-axis.

[0072] In addition, when explaining the intermediate moving member according to one aspect of the present invention below, an intermediate moving member having a structure in which a ball guide portion is arranged in each of the four corner regions is taken as an example for the explanation.

[0073] Figure 3 It is a schematic diagram of the intermediate moving member (Middle guide) of a camera actuator according to one aspect of the present invention, Figure 4 is Figure 3 a schematic diagram of the insert built in the intermediate moving member shown. And, Figure 5 is from the bottom view Figure 3 a schematic diagram of the intermediate moving member shown, Figure 6 is from the first direction view Figure 3 a perspective view of the intermediate moving member shown, Figure 7Viewed from the second direction Figure 3 is a perspective view of the intermediate movable member shown.

[0074] Referring to Figures 3 to 7 , the intermediate movable member 3 of the camera actuator 1 according to an aspect of the present invention is a member supported in such a manner that an optical component including an optical lens, such as a lens barrel (not shown), can perform two-dimensional planar (X-Y plane in the drawing) movement in a plane perpendicular to the optical axis (Z axis in the drawing), and includes ball guide portions 33 each arranged in four corner regions.

[0075] In the present embodiment, each of the ball guide portions 33 is composed of a first-direction ball guide 34 and a second-direction ball guide 35. The first-direction ball guide 34 has a guide surface f made of a metal material, and the guide surface f made of the metal material is formed to be exposed to the upper part of the intermediate movable member 3. Also, the second-direction ball guide 35 similarly has a guide surface f made of a metal material, and the guide surface f made of the metal material is formed to be exposed to the lower part of the intermediate movable member 3.

[0076] In the present embodiment, the first-direction ball guide 34 and the second-direction ball guide 35 constituting one ball guide portion 33 are formed to be adjacent to each other as shown in the drawing, and are separated from each other in a non-coincident or non-overlapping manner when viewed in the optical axis direction (Z-axis direction), and at least a part of them overlaps when viewed in the first direction. Thus, the balls B1 and B2 in contact with the corresponding ball guides 34 and 35 also do not overlap with each other when viewed in the optical axis direction.

[0077] In an existing structure where the optical axis direction positions of the first-direction ball guide and the second-direction ball guide overlap with each other (refer to Figure 1 and Figure 2 ), the balls arranged to roll along the first-direction ball guide and the second-direction ball guide can only be coaxially arranged when viewed in the optical axis direction, and there is a limit in terms of reducing the height of the camera module as a whole.

[0078] On the contrary, in the implementation of the present invention, the first-direction ball guide 34 and the second-direction ball guide 35 are adjacent to each other and are separated from each other in a non-coincident or non-overlapping manner when viewed in the optical axis direction (Z-axis direction). Therefore, the positions of the balls B1 and B2 in contact with the corresponding ball guides do not overlap with each other when viewed in the optical axis direction, and only at least a part of the two ball guides 34 and 35 overlaps when viewed in the first direction (refer to Figure 6 ).

[0079] That is, the first direction ball guide 34 and the second direction ball guide 35 are formed with a structure in which the two balls (balls B1 and B2 respectively contacting the first direction ball guide 34 and the second direction ball guide 35) do not overlap or overlap each other when viewed in a plane (Z-axis direction), but partially overlap the two balls B1 and B2 when viewed in the first direction (X-axis direction) (a structure in which the position of the uppermost end of the ball B2 located below is higher than the position of the lowermost end of the ball B1 located above). When viewed in the first direction, at least a portion of the two balls B1 and B2 overlap, and the overall height is reduced accordingly, thereby enabling a thinner and more compact product.

[0080] The intermediate movable member 3 is preferably composed of an injection molded part 30 made of a synthetic resin material constituting the outer shape of the part and an insert 32 inserted into the injection molded part 30 by insert molding. In this case, the insert 32 may be made of a non-magnetic metal material. This is because if the insert 32 is made of a magnetic body, an additional load may be generated due to the attraction with the planar driving magnets M1 and M2 described later when correcting the vibration.

[0081] If the intermediate movable part 3 is constructed by inserting an insert 32 made of metal into the injection molded part 30, the above-mentioned insert 32 made of metal is inserted into the injection molded part 30, and the overall rigidity of the intermediate movable part 3 is increased accordingly, thereby improving the durability of the product, and the guide surface f that contacts the ball can be formed by a part of the insert 32 made of metal, thereby also being able to solve the existing micro-depression (ball indentation) problem.

[0082] In a preferred embodiment of the present invention, the first direction ball guide 34 can be composed of a first ball guide forming part 301 and a first rail piece 321. The first ball guide forming part 301 is formed in the four corners of the injection molded part 30, and the first rail piece 321 is formed in the insert 32 and inserted into the first ball guide forming part 301. At this time, the first rail piece 321 has a rail surface f (refer to FIG. 1 ) exposed to the upper part of the first ball guide forming part 301 after insertion molding. Figure 4 (partial enlarged view).

[0083] Furthermore, the second direction ball guide 35 can be composed of a second ball guide forming part 302 and a second rail piece 322. The second ball guide forming part 302 is formed integrally with the first ball guide forming part 301. The second rail piece 322 is formed on the insert 32 and inserted into the second ball guide forming part 302. At this time, the second rail piece 322 also has a rail surface f' (refer to FIG. 1 ) exposed to the lower part of the second ball guide forming part 302 at a position offset from the first rail piece 321 after insertion and forming. Figure 4 (partial enlarged view).

[0084] The first rail piece 321 having a guide rail surface f exposed above the first ball guide rail forming portion 301 after insert molding may be configured in an arcuate shape that bulges downward, and the second rail piece 322 having a guide rail surface f exposed below the second ball guide rail forming portion 302 after insert molding may be configured in an arcuate shape that bulges upward contrary to the first rail piece 321 (refer to Figure 4 for a partial enlarged view).

[0085] As Figure 3 and Figure 5 in their respective partial enlarged views, a first tilting correction hole 308 for locally exposing the first rail piece 321 (locally exposing the lower surface portion of the first rail piece 321) may be formed on the lower surface of the first ball guide rail forming portion 301, and a second tilting correction hole 309 for locally exposing the second rail piece 322 (locally exposing the upper surface portion of the second rail piece 322) may be formed on the upper surface of the second ball guide rail forming portion 302.

[0086] The first tilting correction hole 308 and the second tilting correction hole 309 prevent thermal deformation of the first rail piece 321 and the second rail piece 322 due to the high-temperature resin filling the molding space during insert molding or deformation due to shrinkage deviation of the resin object during cooling after molding, and provide a space for introducing a slender tilting correction tool T during the product molding process in such a way that the first rail piece 321 and the second rail piece 322 can maintain an appropriate tilting angle planned during design as Figure 8 shown.

[0087] The intermediate moving member 3 of the camera actuator 1 according to an aspect of the present invention is configured such that when observed in a plane (Z-axis direction), two balls (balls B1 and B2 respectively contacting the first-direction ball guide rail 34 and the second-direction ball guide rail 35) do not coincide or overlap with each other, and when observed in the first direction (X-axis direction), a part of the two balls B1 and B2 overlaps with each other, thereby forming the first-direction ball guide rail 34 and the second-direction ball guide rail 35, which is advantageous for making the product (camera module) thinner and more compact.

[0088] That is, the first-direction ball guide rail 34 and the second-direction ball guide rail 35 are formed in a structure such that when observed in a plane (Z-axis direction), two balls (balls B1 and B2 respectively contacting the first-direction ball guide rail 34 and the second-direction ball guide rail 35) do not coincide or overlap with each other, and when observed in the first direction (X-axis direction), a part of the two balls B1 and B2 overlaps with each other. When observed in the first direction, a part of the two balls B1 and B2 overlaps with each other, and accordingly, the overall height is reduced compared to the prior art, so that a thinner and more compact product can be realized.

[0089] In addition, by adopting a structure in which an insert 32 made of a metal material is inserted into the injection molded part 30, the above-mentioned insert 32 made of a metal material is inserted into the injection molded part 30, and correspondingly, the overall rigidity of the intermediate movable part 3 is increased, which is also beneficial to improving the durability of the product. On the other hand, by providing rail pieces 321 and 322 in contact with the balls by a part of the insert 32 made of a metal material, the problem of existing micro-indentations (ball indentations) during the drop test or actual fall can be significantly solved.

[0090] As described above, as a preferred embodiment, the intermediate movable part having a structure in which a ball guide part is arranged at each of the four corner areas is taken as an example for illustration. However, the position or number of the ball guide parts is not limited to the position or number illustrated in the drawings. In other words, the position or number of the ball guide parts can be arbitrarily changed according to the specifications or structure of the camera module. Therefore, it is indicated that such deformations can also be included in the scope of the present invention.

[0091] Hereinafter, a preferred embodiment of the camera actuator jointly promoted by including the intermediate movable part according to one aspect of the present invention will be described, and the case where the intermediate movable part having a structure in which a ball guide part is arranged at each of the four corner areas as described above is applied will be taken as an example for illustration.

[0092] Of course, as described above, the number or position of the ball guide parts formed in the intermediate movable part is not particularly limited. Therefore, it is indicated that the position or number of the following upper ball guide and lower ball guide formed in a manner corresponding to the above ball guide parts is also not limited to the position or number illustrated in the drawings.

[0093] Figure 9 It is an exploded schematic view showing the camera actuator according to another aspect of the present invention in an exploded manner.

[0094] Refer to Figure 9 , the camera actuator 1 according to another aspect of the present invention includes an intermediate movable part 3 and an upper movable part 2 arranged on the upper part of the intermediate movable part 3. In addition, it has a lower movable part 4 that supports the intermediate movable part 3 of the above-mentioned upper movable part 2 from below and a base 5 that houses the above-mentioned movable parts (upper movable part 2, intermediate movable part 3, lower movable part 4).

[0095] Among them, the above-mentioned intermediate movable part 3 is the same as the intermediate movable part 3 according to one aspect. Therefore, for the sake of convenience of description, the repeated description of the same structure is omitted, and the description is centered on other structures except the intermediate movable part 3.

[0096] The upper movable member 2 is mounted on the intermediate movable member 3 in such a manner as to be capable of synchronous movement in the first direction. Further, the lower movable member 4 supports the intermediate movable member 3 from below in such a manner that the intermediate movable member 3 carrying the upper movable member 2 is capable of synchronous movement in the second direction. The upper movable member 2 and the intermediate movable member 3 are accommodated in the base 5 in such a manner as to be capable of synchronous movement in the optical axis direction in a state of being mounted on the lower movable member 4.

[0097] A first optical axis drive coil C3 and a second optical axis drive coil C4 are respectively arranged on the first side surface and the second side surface adjacent to each other of the base 5. A first optical axis drive magnet M3 and a second optical axis drive magnet M4 corresponding to the first optical axis drive coil C3 and the second optical axis drive coil C4 arranged on the side surface of the base 5 are respectively provided on one side surface and the other side surface of the lower movable member 4.

[0098] When current is applied, the magnetic circuits formed by the corresponding first optical axis drive coil C3 and first optical axis drive magnet M3, and the second optical axis drive coil C4 and second optical axis drive magnet M4 generate a driving force for moving the lower movable member 4 in the optical axis direction with respect to the base 5. By such a driving force, the lower movable member 4 and the movable members 3 and 2 mounted on the lower movable member 4 are simultaneously moved in the optical axis direction, thereby achieving zooming or autofocusing.

[0099] A first planar drive coil C1 and a second planar drive coil C2 are respectively arranged on the third side surface and the fourth side surface of the base 5 facing the first side surface and the second side surface of the base 5. A first planar drive magnet M1 and a second planar drive magnet M2 corresponding to the first planar drive coil C1 and the second planar drive coil C2 are respectively provided on one side surface and the other side surface of the upper movable member 2.

[0100] When current is applied, the magnetic circuits formed by the corresponding first planar drive coil C1 and first planar drive magnet M1, and the second planar drive coil C2 and second planar drive magnet M2 generate a two-dimensional planar force in the base 5 with respect to the plane (X - Y plane) perpendicular to the optical axis with the lower movable member 4 as a reference, for the intermediate movable member 3 and the upper movable member 2 arranged on the lower movable member 4. Shake correction is achieved by such a driving force.

[0101] On the upper movable member 2, a first-direction upper ball guide 24 is formed corresponding to each of the ball guides 34 in the first direction in a symmetrical manner. On the lower movable member 4, a second-direction lower ball guide 45 is formed corresponding to each of the ball guides 35 in the second direction in a symmetrical manner. Further, a ball B1 and a ball B2 are respectively interposed between the corresponding ball guides 34 in the first direction and the first-direction upper ball guide 24, and the ball guides 35 in the second direction and the second-direction lower ball guide 45.

[0102] Accordingly, if the upper movable member 2 is subjected to a force in a certain direction of the first direction by the driving force for correcting jitter acting in a certain direction of the first direction among the above driving forces, the ball B1 rolls between the corresponding ball guides (the first-direction ball guide 34 and the first-direction upper ball guide 24), so that the first-direction synchronous movement of the upper movable member 2 relative to the intermediate movable member 3 can be smoothly achieved.

[0103] The same principle applies to the second direction. If the upper movable member 2 is subjected to a force in a certain direction of the second direction by the driving force for correcting jitter acting in a certain direction of the second direction among the above driving forces, the ball B2 rolls between the corresponding ball guides (the second-direction ball guide 35 and the second-direction lower ball guide 45), so that the second-direction synchronous movement of the intermediate movable member 3 relative to the lower movable member 4 can be smoothly achieved.

[0104] Figure 9 In the figure, the reference numeral HS denotes a Hall sensor that senses a change in the distance between the induction drive magnet and the corresponding drive coil during correction, zooming, or autofocusing and transmits the sensed information to the drive IC. At this time, the drive IC recognizes the position of the movable member in real time from the induction information of the Hall sensor HS, and feeds back and controls the position of the movable member based on the recognized position value compared with the initial position.

[0105] Figure 10 is Figure 9 an internal perspective view of the upper movable member shown, Figure 11 is a schematic view of the upper movable member shown when viewed from the bottom surface Figure 9 of the upper movable member shown.

[0106] As Figure 10 and Figure 11 shown, the above-mentioned upper movable member 2 applicable to the camera actuator 1 according to another aspect of the present invention is composed of an upper injection molded part 20 made of a synthetic resin material forming the outer shape of the upper movable member 2 and an upper insert 22 made of a metal material inserted into the upper injection molded part 20 and decomposed into a plurality of parts. At this time, at least a part (a rear yoke part described later) of the upper insert 22 may be a magnetic body.

[0107] As described above, the upper movable member 2 has the first-direction upper ball guide 24 in a manner symmetric to the first-direction ball guide 34 by one. At this time, the first-direction upper ball guides 24 may be respectively composed of upper ball guide forming parts 202 formed in the four corner regions of the upper injection molded part 20 and upper rail pieces 222 formed at both ends of the first upper insert 22a and the second upper insert 22b formed opposite to each other in the upper insert 22.

[0108] On the upper rail piece 222, a guide surface f that is exposed to the lower part of the upper ball guide forming part 202 after insert molding can be formed. On the upper insert 22a and the second upper insert 22b, the upper insert 22 on the side corresponding to the aforementioned first planar drive magnet M1 can form a first planar drive yoke Y1, and it is formed with a predetermined area, preferably an area corresponding to the aforementioned first planar drive magnet M1.

[0109] The first planar drive yoke Y1 increases the driving force by concentrating the magnetic field generated when the current applied to the aforementioned first planar drive coil C1 magnetizes the first planar drive coil C1 on the side of the first planar drive magnet M1. At the same time, it has the effect of generating an attractive force between it and the first planar drive magnet M1 to prevent the first planar drive magnet M1 from falling off the designated installation position of the upper movable member 2.

[0110] The first upper insert 22a and the second upper insert 22b are structured to face each other and are inserted into one side surface of the upper injection molded part 20 and the other side surface of the facing part. The third upper insert 22c is inserted into the other side surface of the injection molded part 30 in a manner adjacent to the first upper insert 22a and the second upper insert 22b. At this time, the third upper insert 22c constitutes a second planar drive yoke Y2 corresponding to the aforementioned second planar drive magnet M2.

[0111] The second planar drive yoke Y2 increases the driving force by concentrating the magnetic field generated when the current applied to the aforementioned second planar drive coil C2 magnetizes the second planar drive coil C2 on the side of the second planar drive magnet M2. At the same time, it has the effect of generating an attractive force between it and the second planar drive magnet M2 to prevent the second planar drive magnet M2 from falling off the designated installation position of the upper movable member 2.

[0112] When considering the assemblability with the intermediate movable member 3 and the first direction drivability according to manufacturing tolerances, it is preferable that a pair of the four first direction upper ball guides 24 are configured in a V-guide form, and the other pair is configured in a U-guide form. An upper pitch correction hole 208 for locally exposing the upper rail piece 222 can be formed on the upper surface of the upper ball guide forming part 202.

[0113] As a reference, similar to the aforementioned first pitch correction hole 308 or the second pitch correction hole 309, the upper pitch correction hole 208 prevents the thermal deformation of the upper rail piece 222 due to the high-temperature resin filling the forming space during insert molding or the deformation due to the shrinkage deviation of the resin object during cooling after molding, and provides a space for introducing a slender pitch correction tool T during product molding in such a way that the upper rail piece 222 can maintain an appropriate pitch angle planned during design.

[0114] Figure 12 is Figure 9 a schematic view of the lower movable member shown below, Figure 13 is a schematic view of the lower insert member of the lower movable member inserted into Figure 12 And, Figure 14 viewed from the bottom surface Figure 12 a schematic view of the lower movable member shown below.

[0115] As Figures 12 to 14 shown, according to another aspect of the present invention, the above-mentioned lower movable member 4 applicable to the camera actuator 1 may be composed of a lower injection molded part 40 made of a synthetic resin material forming the outer shape of the lower movable member 4 and a lower insert member 42 made of a metal material inserted into the lower injection molded part 40. At this time, at least a part of the lower insert member 42, preferably Figure 13 the cross-hatched part may be made of a magnetic material.

[0116] As described above, the lower movable member 4 has second-direction lower ball rails 45 in a manner symmetric with respect to each of the second-direction ball rails 35. The second-direction lower ball rails 45 may be respectively composed of a lower ball rail forming part 402 and a lower rail piece 422. The above-mentioned lower ball rail forming part 402 is formed in the four corner regions of the above-mentioned lower injection molded part 40, and the above-mentioned lower rail piece 422 is formed in the above-mentioned lower insert member 42 and is inserted and formed in such a way that the rail surface f is exposed to the upper part of the above-mentioned lower ball rail forming part 402.

[0117] A first optical axis driving yoke Y3 corresponding to the above-mentioned first optical axis driving magnet M3 may be formed on one side edge of the lower insert member 42 (the side edge where the aforementioned first optical axis driving magnet M3 is installed), and a second optical axis driving yoke Y4 corresponding to the above-mentioned second optical axis driving magnet M4 may be formed on the other side edge (the side edge where the aforementioned second optical axis driving magnet M4 is installed).

[0118] The first optical axis driving yoke Y3 gathers the magnetic field generated when magnetizing the above-mentioned first optical axis driving coil C3 by the current applied to the above-mentioned first optical axis driving coil C3 to the side of the above-mentioned first optical axis driving magnet M3, thereby increasing the driving force, and at the same time has the effect of generating an attractive force with the first optical axis driving magnet M3 to prevent the above-mentioned first optical axis driving magnet M3 from falling off from the designated installation position of the lower movable member 4.

[0119] Further, when the second optical axis driving rear yoke Y4 is magnetized by the current applied to the aforementioned second optical axis driving coil C4, the magnetic field generated is concentrated on the side of the second optical axis driving magnet M4, thereby increasing the driving force. At the same time, it has the effect of generating an attractive force with the second optical axis driving magnet M4 to prevent the second optical axis driving magnet M4 from falling off the designated installation position of the lower moving member 4.

[0120] Similarly, when considering the assemblability with the intermediate moving member 3 and the second-direction drivability according to manufacturing tolerances, it is preferable that a pair of the four second-direction lower ball guide rails 45 are configured in a V-guide form, and the other pair is configured in a U-guide form. A lower pitch correction hole 408 for locally exposing the lower rail piece 422 may be formed on the lower surface of the lower ball guide forming portion 402.

[0121] Among them, the lower pitch correction hole 408 also prevents the thermal deformation of the lower rail piece 422 caused by the high-temperature resin filling the forming space during the insert molding process or the deformation caused by the shrinkage deviation of the resin object during cooling after molding, and provides a space for introducing the slender pitch correction tool T during product molding in such a way that the lower rail piece 422 can maintain an appropriate pitch angle planned during design.

[0122] On the other hand, as described above, a part of the lower insert 42, more specifically Figure 12 the hatched portion in the middle cross-section is at least composed of a magnetic material. In the hatched portion, the aforementioned first-direction optical axis driving rear yoke Y3 and the second-direction optical axis driving rear yoke Y4 should obviously be made of a magnetic material in terms of function, and the remaining hatched portions are also preferably composed of a magnetic material.

[0123] Thus, if the optical axis driving rear yokes Y3, Y4 and the remaining cross-section portions are made of a magnetic material, the upper moving member 2 is attracted to the lower moving member 4 with the intermediate moving member 3 in between by the attractive force with the corresponding first optical axis driving magnet M3 and second optical axis driving magnet M4. Therefore, stable two-dimensional planar motion without floating or shaking can be achieved when correcting jitter.

[0124] In the camera actuator according to another aspect of the present invention as described above, by applying the intermediate moving guide rail having the aforementioned unique structure (when observed in the plane (Z-axis direction), the two balls (the balls respectively in contact with the first ball guide rail and the second ball guide rail) do not coincide or overlap with each other, and when observed in the first direction (X-axis direction), a part of the two balls overlaps with each other), the product can be made thinner and more compact as a whole.

[0125] In addition, by applying a movable member with a structure of inserting an insert made of a metal material into an injection molded part, the rigidity of the overall product is increased, and it is also beneficial to the durability of the product. By forming a rail piece in contact with the ball from a part of the insert made of a metal material, it has the advantage of being able to significantly solve the problem of existing micro-indentations (ball indentations) during a drop test or an actual fall.

[0126] In the above detailed description of the present invention, only specific embodiments based on this detailed description have been described. However, it should be understood that the present invention is not limited to the specific forms mentioned in the detailed description, but includes all modifications, equivalents, and substitutes within the spirit and scope of the present invention defined by the appended claims.

[0127] Description of Reference Numerals

[0128] 1: Camera actuator 2: Upper movable member

[0129] 3: Intermediate movable member 4: Lower movable member

[0130] 5: Base 20: Upper injection molded part

[0131] 22: Upper insert 24: First direction upper ball guide rail

[0132] 30: Injection molded part of the intermediate movable member 32: Insert of the intermediate movable member

[0133] 33: Ball guide rail part of the intermediate movable member 34: First direction ball guide rail

[0134] 35: Second direction ball guide rail 40: Lower injection molded part

[0135] 42: Lower insert 45: Second direction lower ball guide rail

[0136] 202: Upper ball guide rail forming part 208: Upper pitch correction hole

[0137] 222: Upper rail piece

[0138] 301: First ball guide rail forming part of the intermediate movable member

[0139] 302: Second ball guide rail forming part of the intermediate movable member

[0140] 321: First rail piece of the intermediate movable member

[0141] 322: Second rail piece of the intermediate movable member

[0142] 308: First pitch correction hole 309: Second pitch correction hole

[0143] 402: Lower ball guide rail forming part 408: Lower pitch correction hole

[0144] 422: Lower rail pieces B1, B2: Ball

[0145] C1, C2, C3, C4: Drive coils f: Guide rail surface made of metal

[0146] M1, M2, M3, M4: Drive magnets Y1, Y2, Y3, Y4: Drive back yokes

[0147] HS: Hall sensor.

Claims

1. An intermediate movable member of a camera actuator, comprising two or more ball guide rails, characterized in that: The ball guide rail parts respectively include: A first direction ball guide rail formed in such a way that a guide rail made of metal is exposed toward the upper portion of the intermediate movable member; and A second direction ball guide rail is formed in such a way that a metal guide rail is exposed toward the lower part of the intermediate movable member, The first direction ball guide and the second direction ball guide are adjacent to each other and separated in a manner that they do not overlap each other when viewed in the optical axis direction, and at least partially overlap each other when viewed in a first direction perpendicular to the optical axis direction. The intermediate movable member is composed of an injection molded part made of synthetic resin constituting the outer shape of the intermediate movable member and an insert made of metal inserted into the injection molded part. The first direction ball guide rail is composed of a first ball guide rail forming portion and a first rail piece. The first ball guide rail forming portion is formed at the four corners of the injection molded part. The first rail piece is formed on the insert and has the rail surface exposed to the upper part of the first ball guide rail forming part after insertion forming. The second direction ball guide rail is composed of a second ball guide rail forming portion and a second rail piece. The second ball guide rail forming part is integrally formed with the first ball guide rail forming part, and the second rail piece is formed on the insert and has the rail surface exposed to the lower part of the second ball guide rail forming part at a position offset from the first rail piece after insertion molding.

2. The intermediate movable member of the camera actuator according to claim 1, characterized in that: A first pitch correction hole is formed on the lower surface of the first ball guide rail forming portion to partially expose the first rail piece. A second pitch correction hole is formed on the upper surface of the second ball guide rail forming portion to partially expose the second rail piece.

3. The intermediate movable member of the camera actuator according to claim 1, characterized in that: The insert is a non-magnetic body.

4. A camera actuator, characterized in that, include: The intermediate movable member according to any one of claims 1 to 3; an upper movable member mounted on the intermediate movable member in a manner capable of synchronous movement in a first direction relative to the intermediate movable member; and A lower movable member supports the intermediate movable member from below in such a manner that the intermediate movable member carrying the upper movable member can move synchronously in the second direction.

5. The camera actuator according to claim 4, characterized in that: It also includes a base for accommodating the upper movable member, the middle movable member and the lower movable member. The lower movable member is accommodated in the base in a manner that it can move synchronously along the optical axis direction when carrying the upper movable member and the middle movable member.

6. The camera actuator according to claim 5, characterized in that: A first optical axis driving coil and a second optical axis driving coil are arranged on a first side surface and a second side surface adjacent to each other of the base. The lower movable member is provided with a first optical axis driving magnet and a second optical axis driving magnet corresponding to the first optical axis driving coil and the second optical axis driving coil respectively.

7. The camera actuator according to claim 6, characterized in that: A first planar drive coil and a second planar drive coil are respectively disposed on a third side surface and a fourth side surface of the base facing the first side surface and the second side surface, respectively. A first planar drive magnet and a second planar drive magnet corresponding to the first planar drive coil and the second planar drive coil are respectively provided on the upper movable member.

8. The camera actuator according to claim 7, wherein a first-direction upper ball guide rail corresponding to each of the first-direction ball guide rails of the middle movable member in a symmetric manner is formed on the upper movable member, a second-direction lower ball guide rail corresponding to each of the second-direction ball guide rails of the middle movable member in a symmetric manner is formed on the lower movable member, a ball is interposed between the corresponding first-direction ball guide rail and the first-direction upper ball guide rail, and between the second-direction ball guide rail and the second-direction lower ball guide rail, respectively.

9. The camera actuator according to claim 8, wherein the upper movable member is composed of an upper injection molded part made of a synthetic resin material forming the outer shape of the upper movable member and upper insert parts made of a metal material inserted into the upper injection molded part and decomposed into a plurality of parts.

10. The camera actuator according to claim 9, wherein the first-direction upper ball guide rail is composed of an upper ball guide rail forming part and an upper rail piece, the upper ball guide rail forming part is formed on the upper injection molded part, the upper rail piece is formed at both ends of the first upper insert part and the second upper insert part formed opposite to each other in the upper insert parts, and has a guide surface exposed to the lower part of the upper ball guide rail forming part after insert molding.

11. The camera actuator according to claim 10, wherein a first planar drive yoke that generates an attractive force with the first planar drive magnet is formed in one of the first upper insert part and the second upper insert part, and a third upper insert part adjacent to the first upper insert part and the second upper insert part constitutes a second planar drive yoke that generates an attractive force with the second planar drive magnet.

12. The camera actuator according to claim 10, wherein an upper pitch correction hole for partially exposing the upper rail piece is formed on the upper surface of the upper ball guide rail forming part.

13. The camera actuator according to claim 9, wherein a part or all of the upper insert parts are magnetic bodies.

14. The camera actuator according to claim 8, wherein the lower movable member is composed of a lower injection molded part made of a synthetic resin material forming the outer shape of the lower movable member and a lower insert part made of a metal material inserted into the lower injection molded part.

15. The camera actuator according to claim 14, wherein the second-direction lower ball guide rail is composed of a lower ball guide rail forming part and a lower rail piece, the lower ball guide rail forming part is formed on the lower injection molded part, the lower rail piece is formed on the lower insert part, and has a guide surface exposed to the upper part of the lower ball guide rail forming part after insert molding.

16. The camera actuator according to claim 15, wherein a lower pitch correction hole for locally exposing the lower rail piece is formed on the lower surface of the lower ball guide forming portion.

17. The camera actuator according to claim 14, wherein a first optical axis driving yoke that generates an attractive force with the first optical axis driving magnet is formed on one side edge of the lower insert, and a second optical axis driving yoke that generates an attractive force with the second optical axis driving magnet is formed on the other side edge of the lower insert.

18. The camera actuator according to claim 14, wherein part or all of the lower insert is a magnetic body.

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