Actuator for camera

Abstract

An actuator for a camera according to an embodiment of the present invention comprises: a carrier that moves linearly; a housing that supports the linear movement of the carrier; a plurality of rails provided on one or more of the carrier and the housing; and balls disposed on each of the plurality of rails, in which, in a first rail, which is one of the plurality of rails, the number of balls is one or more greater than the number of balls disposed in the other rails.

Description

TECHNICAL FIELD

[0001] The present application relates to an actuator for a camera, and more particularly, to an actuator for a camera that enhances durability through a structural improvement for linear movement of a carrier and further improves driving accuracy. BACKGROUND

[0002] With the development of hardware technology for image processing and the increase in user demand for image capturing and the like, functions such as Auto Focus (AF), Optical Image Stabilization (OIS), and the like have been applied to independent camera devices and camera modules installed in mobile terminals such as cell phones, smart phones, and the like.

[0003] The Auto Focus (AF) function refers to a function of adjusting the focal length with a subject by linearly moving a carrier on which a lens or the like is mounted in the optical axis direction, thereby generating a clear image in an image sensor (CMOS, CCD, or the like) provided at the rear end of the lens.

[0004] The Optical Image Stabilization (OIS) function refers to a function of improving the sharpness of an image by adaptively moving a carrier on which a lens (or an image sensor) is mounted in a direction of compensating for shaking of the lens or the image sensor in the case where the shaking occurs due to hand jitter.

[0005] One of representative methods of implementing the AF or OIS function is to provide a magnet (coil) on a mover (carrier) and a coil (magnet) on a stator (housing, base, or other form of carrier or the like), and then to generate a driving force between the coil and the magnet, thereby moving the mover in the optical axis direction or a direction perpendicular to the optical axis.

[0006] Recently, in order to organically combine the physical characteristics of a zoom lens with the shape characteristics of a portable terminal, an actuator or a camera module or the like that reflects (refracts) light of a subject using a reflector arranged at the front end of a lens has been disclosed.

[0007] The actuator or the like using the reflector implements OIS by a method of rotating or moving the reflector in one axis or two axes, and implements AF or zoom functions by linearly moving a carrier on which a lens or the like is mounted.

[0008] In the case of such an actuator, the moving distance (stroke) of the carrier that moves in the optical axis direction by AF or zoom control is relatively long compared to other types of actuators, and a heavy lens can be mounted depending on the optical specifications.

[0009] If an external force such as an external impact or a shake is applied to the actuator, a physical impact can occur between the housings (chassis, base, etc.) and the carrier that are spaced apart from each other.

[0010] The internal structure or shape of the actuator is various, and the material is various such as plastic, metal, ceramic, etc. In the case of an actuator having a high weight and a long stroke, the amount of physical impact is larger, and thus not only noise is increased, but also wear, damage, breakage, etc. of the internal structure are more likely to occur.

[0011] Especially, in the case of a large physical impact force, a dent or damage such as a dent of the surface of a ball that guides the physical movement between the housings and the carrier or the surface of the carrier or the housings that contacts the ball can occur, and in the case where a dent, etc. occurs on the ball, etc., tilt, poor posture, etc. of the carrier can occur, and linear movement of the carrier is difficult to be accurately achieved.

[0012] In the case where wear, damage, etc. of the internal structure, etc. occur, the possibility of malfunction itself increases, impurities such as particles, debris, etc. that are separated from the internal structure, etc. are generated and scattered to reduce driving accuracy, and defective pixels, etc. are generated in the imaging element such as a CCD, etc., and thus a significant influence on image quality is generated. SUMMARY

[0013] PROBLEMS TO BE SOLVED BY THE INVENTION The present application has been made to solve the problems described in the background art as described above, and an object thereof is to provide a camera actuator that can not only strengthen durability but also further improve posture stability and driving accuracy of a carrier by improving a structure for physical support and guidance of the carrier.

[0014] Other objects and advantages of the present application will be understood by the following description, and will be more clearly understood by embodiments of the present application. In addition, the objects and advantages of the present application can be achieved by the structure appearing in the claims and the combination of the structures.

[0015] MEANS FOR SOLVING THE PROBLEMS To achieve the above object, a camera actuator according to an embodiment of the present application is configured to include a carrier that performs linear movement, a housing that supports the linear movement of the carrier, a plurality of rails that are provided in one or more of the carrier and the housing, and a ball that is arranged in each rail of the plurality of rails, and in this case, in a first rail that is one rail of the plurality of rails, one or more balls more than the number of balls arranged in the other rails are arranged.

[0016] In detail, the first track of the present application can have a length longer than those of the other tracks, and a U-shaped cross section.

[0017] In addition, the camera actuator according to an embodiment of the present application can further include a driving magnet installed to the carrier, a coil disposed to the housing in opposition to a first surface of the driving magnet, and a magnetic body disposed to the housing in opposition to a second surface of the driving magnet, which is perpendicular to the first surface, and generating an attractive force with the driving magnet.

[0018] In this case, the driving magnet of the present application can be installed to the carrier in a form in which the first surface and the second surface are both exposed to the outside, the magnetic body of the present application can have a shape extending along a moving direction of the carrier, and can be disposed outward of the plurality of tracks.

[0019] Preferably, the first track of the present application can be disposed on one or more of a lower side of the carrier and a bottom surface side of the housing, and in this case, the plurality of tracks can include second tracks disposed on one or more of an opposite lower side of the carrier and an opposite bottom surface side of the housing in parallel with the first track, and having a plurality of the second tracks on the same line.

[0020] In addition, the plurality of balls of the present application can include balls arranged in the first track, and a single number of balls having a diameter greater than that of the balls arranged in the first track and arranged in the second track, respectively.

[0021] According to an embodiment, the camera actuator according to the present application can further include a first magnetic body disposed to the carrier and disposed closer to the second track than to the first track, and a second magnetic body disposed to the housing in opposition to the first magnetic body and generating an attractive force with the first magnetic body.

[0022] In addition, the camera actuator according to the present application can further include a coil disposed to the housing, and a driving magnet installed to the carrier in opposition to the coil and disposed closer to the second track than to the first track.

[0023] Preferably, a virtual line connecting centers of the balls arranged in the second track can be located within a thickness range of the driving magnet.

[0024] According to an embodiment, the carrier of the present application can include: a mount on which a lens is mounted; a first support portion provided on one side of the mount, having a shape extending in the direction of the optical axis, and provided with a driving magnet; and a second support portion provided on the other side of the mount, having a shape extending in the direction of the optical axis, and having a shape extending in a direction opposite to the extending direction of the first support portion.

[0025] In this case, the first track of the present application is provided at the lower portion of the second support portion, the plurality of tracks include second tracks provided at the lower portion of the first support portion in a parallel manner to the first track, and a plurality of the second tracks are provided on the same line.

[0026] Inventive Effects According to an embodiment of the present application, different arrangements and numbers of balls physically supporting the carrier are applied at different positions, so that the physical guidance of the carrier can be effectively achieved, while the damage, wear, etc. of the balls caused by external impact can be more effectively reduced.

[0027] According to an embodiment of the present application, the balls on one side are always in contact with the carrier for guidance, and a plurality of balls are arranged on the other side where a gap can be generated, so that impact buffering and driving accuracy can be effectively achieved.

[0028] According to an embodiment of the present application, the carrier is supported by the balls at three positions as a whole, and the plurality of balls on one side are guided in such a manner that the physical contact of the carrier is made variable, so that the contact change caused by the balls can be minimized, and the inclination and attitude failure of the carrier, etc. can be effectively reduced.

[0029] According to an embodiment of the present application, the mutual relationship between the position where the driving force is generated by the magnet, the moving line where the carrier is linearly moved, and the linear line where the carrier is physically supported by the balls is structurally improved, so that the linear movement of the carrier can be more stably achieved. BRIEF DESCRIPTION OF DRAWINGS

[0030] The following drawings attached in the present specification illustrate preferred embodiments of the present application, and together with the detailed description of the present application described later, play a role in making the technical idea of the present application more effectively understood, and therefore the present application should not be interpreted as being limited to the matters described in such drawings.

[0031] Figures 1 to 3 is a view showing the overall configuration of a camera actuator and a camera module according to a preferred embodiment of the present application.

[0032] Figure 4is a diagram showing a detailed configuration of a reflector module according to a preferred embodiment of the present application.

[0033] Figure 5 is a diagram showing a detailed configuration of a camera actuator according to the present application.

[0034] Figure 6 is a diagram showing a detailed configuration of a ball and a track according to an embodiment of the present application.

[0035] Figure 7 and Figure 8 is a diagram showing a detailed configuration of a ball and a track according to another embodiment of the present application.

[0036] Figure 9 is a diagram showing a track structure provided to a housing and a carrier.

[0037] Figure 10 is a diagram showing a structure of a magnetic body according to an embodiment of the present application.

[0038] Figure 11 is a diagram showing a carrier according to an embodiment of the present application.

[0039] Figure 12 and Figure 13 is a diagram showing a structural relationship of a drive magnet and a magnetic body according to an embodiment of the present application.

[0040] Figure 14 is a diagram showing a relationship of a drive magnet and a ball according to an embodiment of the present application.

[0041] Figure 15 is a diagram showing a structure of a carrier according to another embodiment of the present application.

[0042] Figure 16 is a diagram showing an overall structure of a camera actuator according to another embodiment of the present application.

[0043] Explanation of Reference Numerals 1000: camera module 100: actuator 110: housing 120, 130: carrier 121A, 121B: first support portion, second support portion 122: mount 170: circuit substrate 190: housing 191: open port 200: reflector module 210: reflector 220: rotating carrier 230: intermediate guide 30: image sensor 50: fixed lens B1: first ball B2: second ball B3: third ball C1: first coil C2: second coil C3: third coil M1: first magnet M2: second magnet M3: third magnet D: driver Y1: magnetic body Y2: yoke plate MS: first magnetic body R1: first rail R2: second rail DETAILED DESCRIPTION Hereinafter, preferred embodiments of the present application will be described in detail with reference to the accompanying drawings. Before such descriptions, it is to be noted that the terms or words used in the present specification and claims should not be interpreted as being common or dictionary definitions thereof, but interpreted as having meanings and concepts compliant with the technical idea of the present application based on the principle that the inventor can appropriately define the concept of the terms in order to best explain own application.

[0044] Therefore, the embodiments described in the present specification and the structures shown in the accompanying drawings are merely the most preferred one of the present application, and cannot represent the entire technical idea of the present application, and it is understood that there can be a variety of equivalents and modifications to the present application.

[0045] Figures 1 to 3 is a diagram showing the overall configuration of a camera actuator (hereinafter, referred to as "actuator") 100 and a camera module 1000 according to a preferred embodiment of the present application, Figure 4 is a diagram showing the detailed configuration of a reflector module 200 according to a preferred embodiment of the present application.

[0046] The actuator 100 of the present application can not only be realized as a separate device by itself, but also as a camera module 1000 including the reflector module 200 and the like as shown in Figure 1

[0047] The actuator 100 of the present application can be an actuator that linearly moves a carrier 120 on which a lens, a lens module, or a lens assembly (hereinafter, referred to as "lens") L is mounted in an optical axis direction or the like to realize auto focus (AF) or zoom.

[0048] A single number of carriers 120 is shown in the diagram, but according to the embodiment, as shown in Figure 16 it is self-evident that the actuator 100 of the present application can include a plurality of carriers 120, 130.

[0049] ​The reflector module 200, which can be provided on the front side (light axis direction reference) of the actuator 100, performs the following function: if light is incident through an open port 191, which is formed in a housing 190 serving as a shield can or the like, or the like, the light path Z1 of the subject is reflected or refracted toward the path Z in the direction of the lens L. In this way, the light reflected or refracted in the direction of the optical axis is incident on the image sensor 30, such as a CMOS, a CCD, or the like, via the lens L.

[0050] The reflector module 200, which changes the path of light, can include a reflector 210, which can be constituted by one selected from a mirror or a prism or a combination thereof. The reflector 210 can be implemented by various components capable of changing the light incident from the outside in the direction of the optical axis, but in order to improve optical performance, it is preferable to be implemented by a glass material.

[0051] The camera module 1000 of the present application, which includes the reflector module 200 or the like, is constituted in a manner to refract the path of light so that the light is incident in the direction of the lens, and thus the device itself can be disposed in the length direction rather than in the thickness direction of the portable terminal, and thus the miniaturization and slimming of the portable terminal or the like can be optimized.

[0052] According to the embodiment, the reflector 210 can also be constituted to move in rotation by a driving unit or the like, such as a magnet and a coil, which generates a magnetic force. If the reflector 210 moves or rotates in this way, the light of the subject reflected (refracted) by the reflector 210 moves in the ±Y direction and / or the ±X direction to be incident on the image sensor 30, and thus correction in the X-axis and / or Y-axis direction caused by hand shake can be implemented.

[0053] Specifically, the reflector module 200 can be constituted to include a rotating carrier 220 for disposing the reflector 210 and an intermediate guide 230.

[0054] The rotating carrier 220 is constituted to move in rotation with the intermediate guide 230 as a reference if a magnetic force (electromagnetic force) is generated between the third magnet M3 disposed in the rotating carrier 220 and the third coil C3 (see Figure 5 ) disposed on the housing 110 side. In the drawing, as one embodiment thereof, an embodiment in which the intermediate guide 230 is taken as a relative stator and the rotating carrier 220 moves in rotation with the YZ plane as a reference is shown (see Figure 4 ).

[0055] If the rotating carrier 220 moves in rotation with the YZ plane as a reference, that is, with the X-axis direction as an axis RA (see Figure 4 ), the reflector 210 also rotates in the same direction together with the physical movement thereof.

[0056] Since the reflector 210 has an inclined surface that reflects the light of the subject, if the reflector 210 rotates and moves with the YZ plane as a reference, the path of the light incident on the image sensor 30 side will be shifted along the Y-axis direction, thus correcting for hand shake in the Y-axis direction.

[0057] According to the embodiment, in one or more of the intermediate guide 230 and the rotating carrier 220, a guide rail 222 for accommodating or guiding the third ball B3 may be formed on the surface of the intermediate guide 230 and the rotating carrier 220 that are opposite to each other.

[0058] On the other hand, if the second magnet M2 and the second coil C2 (see) are located in the intermediate guide 230 Figure 5 When a magnetic force (electromagnetic force) is generated between the two, the intermediate guide 230 rotates with the XZ plane as a reference while carrying the rotating carrier 220.

[0059] If the intermediate guide 230 rotates with the XZ plane as a reference, the reflector 210 also rotates, so the path of the light incident on the image sensor 30 moves (shift) along the X-axis direction, while correcting hand shaking in the X-axis direction component.

[0060] As illustrated, to guide the rotation of the intermediate guide 230 (XZ plane reference), a circular guide rail 232 can be provided on the rear surface of the intermediate guide 230. The second ball bearing B2 (see...) Figure 4 , Figure 6 (etc.) can be arranged in such a way that a portion of it is accommodated within the guide rail 232.

[0061] The light from the subject reflected by the reflector module 200 is incident on the lens L located inside the actuator 100. The position (optical axis direction reference) of the lens L is adjusted by the actuator 100 of the present invention, thereby realizing functions such as zoom or AF.

[0062] The image sensor 30 can be designed to interface with the motherboard of an application device (such as a smartphone) used to set the actuator 100 of the present invention, and therefore can be set inside the actuator 100 of the present invention, specifically inside the housing 110. However, as illustrated, it is self-evident that it can be set outside at a position corresponding to the opening formed in the lower part (Z-axis reference) of the housing 110.

[0063] On the other hand, such as Figure 16 As illustrated, there can be multiple carriers 120 and 130 that each mounts a separate lens 60 and 70. Furthermore, to improve optical performance such as zoom ratio of the actuator 100, etc. Figure 16As illustrated, a fixed lens 50 may be provided in front of the actuator 100.

[0064] It goes without saying that the reflector module 200, which provides reflector 210, can be composed of independent modules. According to embodiments, the actuator 100 of the present invention may also include a yoke plate Y2 (see...). Figure 10 The yoke Y2 prevents magnetic leakage and concentrates magnetic force (electromagnetic force) on the magnet.

[0065] The axes shown in the accompanying drawings, the terms used to refer to those axes, and the terms such as upper, lower, front, rear, vertical, and horizontal used to describe the axes are clearly only used to indicate the relative references for illustrating embodiments of the present invention, rather than to specify a direction or position from an absolute reference. It is self-evident that these terms can vary relative to the position of the object being described, the position of the observer, the view direction, etc.

[0066] Figure 5 This is a diagram illustrating the detailed configuration of the actuator 100 according to the present invention. (See diagram for details.) Figure 5 As shown, the actuator 100 of the present invention is equivalent to the basic skeleton or frame structure of the actuator 100, which may include a housing 110 for accommodating the internal structure and a carrier 120 for mounting a lens L that projects light onto the image sensor 30.

[0067] The carrier 120 of the present invention, which carries the lens L, is equivalent to a mover. This mover moves linearly along the optical axis (Z-axis direction) by the magnetic force (electromagnetic force) between the first magnet M1, which is a driving magnet, and the first coil C1. From the corresponding viewpoint, the housing 110 that supports the linear movement of the carrier 120 is equivalent to a relative stator.

[0068] The carrier 120 has a first magnet M1, and the housing 110 has a first coil C1, which is opposite to the first magnet M1 and provides driving force to the first magnet M1.

[0069] If an appropriate amount and direction of power is applied to the first coil C1 under the control of the driver D, a magnetic force (electromagnetic force) is generated between the first coil C1 and the first magnet M1, and the carrier 120 moves forward and backward along the optical axis by the generated magnetic force (electromagnetic force).

[0070] If the carrier 120 moves linearly along the optical axis (Z-axis direction), the lens L mounted on the carrier 120 also moves linearly along the optical axis, thus achieving AF or zoom function.

[0071] A first ball bearing B1 can be arranged between the carrier 120 and the housing 110 (see...). Figure 6(etc.) so that the carrier 120 can move linearly more flexibly with minimal friction. Preferably, the first ball B1 is arranged on one or more tracks R1, R2 provided in the carrier 120 and the housing 110.

[0072] Preferably, the first ball B1 is configured to be housed as a part of the tracks R1, R2 to effectively guide the linear movement of the carrier 120.

[0073] With the first ball B1 arranged between the carrier 120 and the housing 110, the following advantages can be achieved: by minimizing the friction caused by the rolling, moving, rotating, and point-contact of the ball with the relative object, the mover (carrier) can move linearly more flexibly, which can not only reduce noise and minimize driving force, but also improve driving accuracy.

[0074] The aforementioned first coil C1, driver D, etc. can be mounted on the circuit board 170. Preferably, the circuit board 170 can be configured such that part or all of it is exposed to the outside so as to interface with external modules, power units, external devices, etc.

[0075] The structure of tracks R1 and R2 according to a preferred embodiment of the present invention will be described in detail below.

[0076] Figure 6 This is a diagram illustrating the detailed configuration of the first ball B1 and the tracks R1 and R2 according to an embodiment of the present invention. Figure 7 and Figure 8 This is a diagram illustrating the detailed configuration of the first ball B1 and the tracks R1 and R2 according to another embodiment of the present invention.

[0077] The actuator 100 according to the present invention may include a plurality of tracks R1, R2, which have a shape extending along a direction corresponding to the direction of linear movement of the carrier 120. The plurality of tracks R1, R2 may be disposed on one or more of the carrier 120 and the housing 110, and a first ball B1 is arranged on each of the plurality of tracks R1, R2.

[0078] As shown in the figure, the tracks R1 and R2 can be formed into a shape in which the groove extends along the length direction (Z-axis direction) to effectively realize the movement of the first ball B1 and the linear movement of the carrier 120 physically supported by the first ball B1.

[0079] Figures 6 to 8 The tracks R1 and R2 provided in the housing 110 are shown. Figure 9The tracks R1 and R2 are shown in both the housing 110 and the carrier 120. Figure 11 and Figure 13 The tracks R1 and R2 on the carrier 120 are shown.

[0080] As shown in these figures, tracks R1 and R2 can be arranged opposite to each other on the carrier 120 and the housing 110, respectively. However, according to the embodiment, tracks R1 and R2 may be provided only on one of the carrier 120 and the housing 110. In this case, in the structure without tracks R1 and R2, a groove or storage portion may be provided to accommodate the first ball B1 or to prevent the first ball B1 from dislodging outward.

[0081] To ensure stable support for the carrier 120, as illustrated in the figure, the aforementioned multiple tracks R1 and R2 can be distributed across multiple locations. As an example, Figure 6 An embodiment is shown with four tracks R1 and R2 disposed on the housing 110. Figure 7 and Figure 8 An embodiment is shown in which three tracks R1 and R2 are disposed on the housing 110.

[0082] Correspondingly, Figure 13 An embodiment is shown in which four tracks R1 and R2 are arranged on the carrier 120. Figure 11 An embodiment is shown in which three tracks R1 and R2 are arranged on the carrier 120.

[0083] On one of the multiple tracks R1 and R2, there can be more than one more first ball B1 than on the other tracks.

[0084] With this implementation structure, not only can the physical support for the linear movement of the carrier 120 be effectively achieved, but the external forces exerted by falling, shaking, impact, etc. are also dispersed, thereby suppressing the occurrence of damage, breakage, defects (scar) or dents of the first ball B1 and the parts in contact with the first ball B1 (the track provided by the carrier or housing).

[0085] Hereinafter, the track with more than one more first ball B1 arranged on the other tracks R1 and R2 is called the first track R1, and the track other than the first track R1 is called the second track R2.

[0086] Even if the balls are designed to have the same diameter (size), it is impossible to make the diameters of the balls completely consistent. Therefore, even if multiple balls are arranged on the same track, these balls may not contact the carrier 120 at the same time. As a result, the balls that actually contact the carrier 120 (hereinafter referred to as "contact balls") may change at any time when the carrier 120 moves.

[0087] The random movement and stopping behavior of the carrier 120 may also be the reason for the phenomenon that the contact balls change constantly when the carrier 120 moves.

[0088] If the ball bearings that are in actual contact with the carrier 120 change at any time, the carrier 120 may become unsteady or tilted. This will not only reduce the driving accuracy of the carrier 120, but may also degrade the optical performance of the actuator, such as causing image degradation.

[0089] Two or more first balls B1 can be arranged on each track R1 and R2. However, when the number of first balls B1 arranged increases, the above-mentioned problem may occur. Therefore, it is preferable to arrange multiple first balls B1 on the first track R1 and one first ball B1 on the second track R2.

[0090] Since the first ball B1 of the first track R1 is arranged in a manner that is greater than that of the other tracks (second track R2), it is preferable that the length D1 of the first track R1 (in the Z-axis direction of the reference figure) is longer than the length D2 of the second track R2, so as to ensure the range of movement of the plurality of first balls B1 arranged in the first track R1 and the sufficient area in which the plurality of first balls B1 physically support the carrier 120.

[0091] Preferably, such as Figure 7 and Figure 11 As illustrated, the first track R1 is provided on one of the lower side of the carrier 120 and the bottom side of the housing 110, and the second track R2 is provided on one of the other side of the lower side of the carrier 120 and the bottom side of the housing 110 in a manner parallel to the first track R1, and multiple second tracks R2 are provided on the same line.

[0092] With the first track R1 and the second track R2 in this configuration, the physically supported portion of the carrier 120 can be separated and distributed in three locations, thereby effectively achieving stable support and linear movement of the carrier 120.

[0093] In addition, in multiple ( Figure 7 (Base, 2) The diameter of the first ball B1 arranged in the second track R2 can be larger than the diameter of the first ball B1 arranged in the first track R1.

[0094] In this way, when the diameters of the first balls B1 arranged in the first track R1 and the second track R2 are different according to the tracks R1 and R2, it is possible to guide the first balls B1 arranged in a single number in the second track R2 and spaced at a relatively far distance to always be in contact with the carrier 120, and to guide the contact point to be changed only by using two or more first balls B1 arranged in the first track R1.

[0095] Regarding this structure, since slight changes in the contact points may occur, there may be a slight decrease in driving accuracy. However, it can not only minimize contact point changes but also predict the range of contact point changes, so it can be fully controlled through calibration algorithms.

[0096] In the case of an actuator with a structure that fixes the carrier by three balls, it is effective in that no contact change occurs. However, in the case of an actuator with a long stroke, such as a zoom drive actuator, the fatal defect of the three ball support itself being destroyed may occur depending on the position of the carrier as the mover, the acceleration of the carrier, and the random drive of the carrier's stopping and moving.

[0097] In the embodiment of the present invention described above, the contact change can be guided to occur only in the plurality of first balls B1 arranged on the first track R1, thereby enabling more stable support of the carrier 120 in a long-stroke environment such as zoom drive with the contact change itself minimized.

[0098] In the case of the above-described structure according to the present invention, the structure becomes as follows: the two fulcrums (the first ball B1 of the second track R2) forming the bottom edge (relatively long distance) of the ladder shape are always in contact with the carrier 120, and the two fulcrums (the plurality of first balls B1 of the first track R1) forming the top edge (relatively short distance) of the ladder shape are in contact with the carrier 120 in a variable manner.

[0099] Therefore, with the structure described above according to the present invention, the carrier 120 can be supported more stably in long-stroke environments such as zoom drive.

[0100] Furthermore, in the case of the structure of the present invention, when an external force is applied, the impact of the external force is dispersed by the plurality of first balls B1 on the first track R1, thereby minimizing the occurrence of wear, damage, dents, etc.

[0101] In this regard, preferably, a structural design is adopted to guide the application of external forces in such a way that the point of application of the external force is, as far as possible, the second track R2 rather than the first track R1. This will be described later.

[0102] Figure 9This diagram illustrates the track R1 and R2 structures provided in the shell 110 and the carrier 120. Figure 10 This is a diagram illustrating the structure of a magnetic body Y1 according to an embodiment of the present invention.

[0103] Regarding the tracks R1 and R2 for arranging the first ball bearing B1, the cross-section of one of the tracks R1 and R2 (the vertical cross-section based on the optical axis direction) can be formed in a "V" shape, and the cross-section of the other track can be formed in a "U" shape.

[0104] When the cross-sections of the first track R1 and the second track R2 are configured to have different shape features, the contact points with the first ball B1 and the rotational characteristics can be configured to be different, thereby improving the linear movement and driving efficiency of the carrier 120 moving along the optical axis.

[0105] If a second track R2 with a "V" shaped cross-section is provided in both the carrier 120 and the housing 110, the second track R2 is arranged such that the wide areas of the grooves face each other, and a first ball B1 is arranged between them. Therefore, the first ball B1 makes point contact with both the second track R2 of the carrier 120 and the second track R2 of the housing 110, and through this contact relationship, the carrier 120 moves linearly at the same time.

[0106] The "V-shaped" cross-section refers not only to the V-shape of the letter itself, but also to the shape in which the ball and the inner side of the track make contact at two points. The "U-shaped" cross-section refers not only to the U-shape of the letter itself, but also to the existence of a certain degree of free space between the ball and the track.

[0107] When the cross-section of the second track R2 provided by either the carrier 120 or the housing 110 is U-shaped, it is preferable that the cross-section of the second track R2 provided by the other is V-shaped, so as to facilitate the linear movement of the carrier 120.

[0108] As an example, the attached drawings show the following embodiment: the cross-sections of the first track R1 and the second track R2 disposed on the housing 110 are both V-shaped, the cross-section of the second track R2 disposed on the carrier 120 is V-shaped, and the cross-section of the first track R1 disposed on the carrier 120 is U-shaped.

[0109] Preferably, as described above, the first ball B1 arranged on the second track R2 is always in contact with the carrier 120, and the plurality of first balls B1 arranged on the first track R1 are in contact with the carrier 120 in a variable manner.

[0110] In this case, in order to effectively achieve physical support and movement guidance by the first ball B1 arranged on the second track R2, as illustrated, it is preferable that the cross section of the second track R2 is formed in a V shape, and the cross section of the first track R1, which is arranged to contact the first ball B1 in a variable manner with the carrier 120, is formed in a U shape.

[0111] As described above, in the embodiment where both the carrier 120 and the housing 110 have a first track R1, it is self-evident that only one of the first track R1 provided on the carrier 120 and the first track R1 provided on the housing 110 can be formed into a U-shape.

[0112] When the track cross-section is V-shaped, the ball makes point-contact with the track, so there is almost no gap between the ball and the track. However, when the track cross-section is U-shaped, gaps may occur between the ball and the track.

[0113] Therefore, when an external force is applied, there is a high probability that the balls arranged on the U-shaped track will be damaged, worn, or dented.

[0114] In order to reflect this problem in the structure, preferably, a plurality of first balls B1 capable of dispersing the impact caused by external forces are arranged on a first track R1 which is a U-shaped track.

[0115] The carrier 120 of the present invention may have a first magnetic body MS (see Figure 11 The housing 110 has a magnetic body Y1, which is arranged opposite to the first magnetic body MS and generates an attraction between them.

[0116] One or more of the first magnetic body MS and magnetic body Y1 mentioned above can be made of magnets. However, considering the driving efficiency and the movement range of the carrier 120, it is preferable that the first magnetic body MS provided by the carrier 120 as the mover is made of magnets. As illustrated in the figure, the magnetic body Y1 provided by the housing 110 is made of a plate of magnetic material (such as metal) with a shape in which its length extends along the direction of movement of the carrier 120.

[0117] If an attractive force or suction force is generated between the first magnetic body MS and the magnetic body Y1, then with the first ball B1 inserted between the carrier 120 and the housing 110, the carrier 120 is in close contact with the housing 110 in the direction of the housing (X-axis direction of the reference figure), so that the physical contact between the first ball B1 and the carrier 120 and between the first ball B1 and the housing 110 can be sustained.

[0118] In order to guide the first ball B1 arranged on the second track R2 in such a way as described above, so that it is always in contact with the carrier 120, preferably, the first magnetic body MS disposed on the carrier 120 is disposed at a position that is relatively closer to the second track R2 than the first track R1.

[0119] Furthermore, when the first magnetic body MS and the magnetic body Y1 are arranged to be biased along the direction of the second track R2, the contact force between the carrier 120 and the housing 110 where the first ball B1 arranged on the second track R2 is involved can be relatively improved.

[0120] Therefore, when an external force is applied to the actuator 100, the impact of the impact caused by the external force on the first ball B1 arranged on the second track R2, i.e. the first ball B1 that actually guides the linear movement of the carrier 120, can be reduced or weakened.

[0121] Compared with the first ball B1 arranged on the second track R2, the first ball B1 arranged on the first track R1 has a relatively weaker clamping force, so it may be more affected by external impacts. However, as mentioned above, since multiple first balls B1 are arranged on the first track R1, external impacts can be effectively dispersed.

[0122] The linear movement of the carrier 120 is primarily guided by multiple second tracks R2 on the same line and a first ball B1 arranged on the second tracks R2. Therefore, preferably, the first magnet M1, which serves as the driving magnet and is arranged on the carrier 120 opposite to the first coil 1, is positioned closer to the second tracks R2 than the first tracks R1, so as to minimize the load caused by the linear movement.

[0123] In summary, preferably, the second track R2 is arranged at a position close to the location of the first magnet M1, which serves as the driving magnet, and the first track R1 is arranged in a manner parallel to the second track R2, and is arranged at a position relatively separated from the first magnet M1 compared to the second track R2.

[0124] Figure 11 This is a diagram illustrating a carrier 120 according to an embodiment of the present invention. Figure 12 and Figure 13 This is a diagram illustrating the structural relationship between the first magnet M1 and the magnetic body Y1 according to an embodiment of the present invention.

[0125] Figure 11 This shows the settings and references. Figures 7 to 9 The diagram illustrates the carrier 120 corresponding to tracks R1 and R2 of the housing 110. Figure 12 and Figure 13 This indicates that the settings are as described above. Figure 6The diagram illustrates the carrier 120 corresponding to the tracks R1 and R2 of the housing 110.

[0126] Figure 11 An embodiment of the carrier 120 is shown, wherein a single number of first tracks R1 and a pair of second tracks R2 are arranged parallel to each other along a direction corresponding to the direction of movement of the carrier 120.

[0127] Preferably, as described above, the first coil C1 and the like that driving the linear movement of the drive carrier 120 are arranged closer to the second track R2 than the first track R1, and the first magnetic body MS and the magnetic body Y1 that generates attraction with the first magnetic body MS are also biased to be closer to the second track R2 than the first track R1.

[0128] Figure 11 The first track R1 shown has a U-shaped cross-section. In this case, as described above, the cross-section of the first track R1 provided on the housing 110 can be V-shaped, so as to be opposite to the first track R1 provided on the carrier 120.

[0129] The branch extending laterally from the main body of the magnetic body Y1 provided in the housing 110 is a structure used to improve the bonding force with the housing 110 during injection molding and the like.

[0130] Furthermore, the space formed in the upper and lower (Z-axis reference) parts of the main body of the magnetic body Y1 is structured as follows: when the carrier 120 moves to the upper or lower (Z-axis reference), it guides the first magnetic body MS of the carrier 120 to relatively reduce the attraction between the magnetic body Y1 and the magnetic body, and generates a relatively large attraction in the middle part of the magnetic body Y1.

[0131] That is, the structure of the magnetic body Y1 described above can provide a force that causes the carrier 120 to return to the middle part of the magnetic body Y1 when the carrier 120 moves to the upper or lower end.

[0132] With this structure, the magnetic body Y1 of the present invention can suppress the carrier 120 from colliding with the housing 110 or the like in the upper or lower direction of the movement range (stroke), and can reduce the force exerted by the collision.

[0133] like Figure 12 and Figure 13 As shown in the embodiment, in order to improve the driving force, a first magnet M1 can be provided on both sides of the carrier 120.

[0134] As shown in the figure, the first surface P1 of the first magnet M1 is exposed in the direction opposite to the first coil C1, and the second surface P2 of the first magnet M1, which is a surface perpendicular to the first surface P1, is exposed in the direction of the magnetic body Y1. The magnetic body Y1 is disposed in the housing 110 and generates attraction with the first magnet M1.

[0135] That is, such as Figure 12 and Figure 13 The first magnet M1 of the carrier 120 shown serves as a driving magnet, simultaneously driving the movement of the carrier 120 in relation to the first coil C1 and generating a close-fitting force in relation to the magnetic body Y1.

[0136] Furthermore, the second surface P2 of the first magnet M1, that is, the surface opposite to the magnetic body Y1 disposed in the housing 110, is mounted on the carrier 120 in an exposed form, thereby enhancing the attraction (adhesion) between the first magnet M1 and the magnetic body Y1.

[0137] like Figure 13 As illustrated, preferably, the magnetic body Y1 disposed in the housing 110 is configured to have a shape that extends along a direction corresponding to the movement line of the carrier 120.

[0138] In addition, preferably, the magnetic body Y1 is disposed further outward than the plurality of tracks R1, R2, so as to more stably realize the physical support of the carrier 120 by the first ball B1 arranged on the tracks R1, R2.

[0139] Figure 14 This is a diagram illustrating the relationship between a first magnet M1, which serves as a driving magnet, and a first ball B1 according to an embodiment of the present invention.

[0140] As described above, the linear movement of the carrier 120 is mainly guided by a plurality of second tracks R2 on the same line and a first ball B1 arranged on the second track R2. In order to be organically combined with the driving force, preferably, the first magnet M1, which serves as the driving magnet, is mounted on the carrier 120 at the position where the second track R2 is located.

[0141] The driving force that moves the carrier 120 is the magnetic force (electromagnetic force) between the first coil C1 and the first magnet M1, which acts on the first magnet M1 mounted on the carrier 120 as a relative mover.

[0142] Therefore, in order to improve driving efficiency and reduce load, it is preferable to minimize the gap or position difference between the structure (second track R2) that physically supports the carrier 120 as the mover and the object that applies the driving force (first magnet M1).

[0143] In this respect, preferably, such asFigure 14 As shown, the first ball bearing B1, which provides physical support to the carrier 120 and guides the linear movement of the carrier 120, is specifically arranged in the second track R2. The first ball bearing B1 is located in the lower part of the carrier 120, as shown in the figure, within the thickness range D of the first magnet M1 that exerts the driving force.

[0144] That is, preferably, the second track R2 is disposed at the lower part of the carrier 120, and is disposed in an appropriate area where the line VL connecting (hypothetical) the first balls B1 respectively arranged in the second track R2 can be located within the thickness range D of the first magnet M1.

[0145] like Figure 14 As shown, there may be two or more second tracks R2. In this case, preferably, the second tracks R2 are arranged in positions that are symmetrical to each other with respect to the first magnet M1.

[0146] Figure 15 This is a diagram illustrating the structure of a carrier 120 according to another embodiment of the present invention.

[0147] According to an embodiment of the present invention, the carrier 120 may include a first support portion 121A, a second support portion 121B, and a mounting base 122 having a mounting space 122S for mounting a lens L.

[0148] like Figure 15 As shown, the first support portion 121A of the "Silly Girl Book" is provided on one side of the mounting base 122 (Y-axis reference) and has a shape E1 extending along the optical axis direction (Z-axis direction). A first magnet M1, serving as a driving magnet, is provided on the aforementioned first support portion 121A.

[0149] The second support portion 121B is disposed on the left and right sides of the mounting base 122, and does not have the side portion of the first support portion 121A described above. It has a shape extending along the optical axis direction and has a direction extending along the same direction as the first support portion 121A described above. Figure 15 The reference, positive Z-axis direction) opposite direction ( Figure 15 The shape E2 extends from the reference (negative Z-axis direction).

[0150] With the first support portion 121A and the second support portion 121B extending along the optical axis and in different directions from each other, the area for physical support can be expanded based on the entire carrier 120, thereby enabling more stable support of the carrier 120.

[0151] Furthermore, when the first support portion 121A and the second support portion 121B extend in different directions relative to each other with the optical axis as a reference, even if external impacts are applied, the external impacts can be dispersed more effectively, and the amount of physical impact on the first ball B1 can be reduced, thereby minimizing wear, damage, dents, etc. that may occur in the first ball B1.

[0152] Furthermore, according to this embodiment of the invention, the length or region linearly supported by the first track R1 and the second track R2 is expanded, thus more effectively suppressing problems such as twisting and tilting of the carrier 120, which disrupt its linearity.

[0153] Since the first magnet M1, which serves as the driving magnet, is disposed on the first support portion 121A, the driving force between the first coil C1 and the first magnet M1 is first applied to the first support portion 121A. Therefore, a uniform driving force is not applied to the entire carrier 120 simultaneously, which may result in a rotational component of the force acting on the carrier 120.

[0154] However, as in the embodiment of the present invention, when the first support portion 121A and the second support portion 121B are configured to extend in different directions relative to each other with reference to the optical axis, thereby increasing the distance between the first support portion 121A and the second support portion 121B, the rotational component of the carrier 120 that may occur during the transmission of driving force can be reduced more effectively.

[0155] For purposes such as weight distribution and stable support, such as Figure 15 As shown, preferably, the aforementioned first track R1, i.e., the first track R1 in which more than one more first ball B1 is arranged than the number of first ball B1 arranged in other tracks, is provided in the lower part of the second support 121B.

[0156] As described above, the second track R2 can be arranged in parallel with the first track R1 at the lower part of the first support 121A, and multiple second tracks R2 are provided on the same line.

[0157] To effectively distribute the center of gravity, ensure sufficient space for the first magnet M1, reduce the space occupied by the carrier 120, and effectively suppress rotational components, preferably, the length of the second support portion 121B is less than the length of the first support portion 121A (E2). <E1)。

[0158] While the present invention has been described above with reference to specific embodiments and accompanying drawings, it is not limited thereto. It is self-evident that those skilled in the art to which this invention pertains can make various modifications and variations within the scope of the technical concept of the invention and the equivalents of the claims described below.

[0159] In the above description of the present invention, modifiers such as first, second, etc. are merely tool concepts used to distinguish between constituent elements, and therefore should not be used to indicate a specific order, priority, etc.

[0160] For the purpose of illustrating the present invention and its embodiments, the accompanying drawings and other illustrations may be shown in a slightly exaggerated form to emphasize or highlight the technical content of the present invention. However, it should be understood that various modifications and applications can be made by those skilled in the art, taking into account the above content and the matters shown in the drawings, etc.

Claims

1. An actuator for a camera, characterized by, Comprising: a carrier that performs linear movement; a housing that supports the linear movement of the carrier; a plurality of rails provided in one or more of the carrier and the housing; and a plurality of balls arranged in each of the plurality of rails, in a first rail that is one of the plurality of rails, one or more balls are arranged than in the other rails.

2. The camera actuator according to claim 1, wherein the first rail has a longer length than the other rails.

3. The camera actuator according to claim 1, wherein the first rail has a U-shaped cross section. Further comprising:

4. The actuator for a camera according to claim 1, wherein a drive magnet mounted to the carrier; a coil provided in the housing opposite a first surface of the drive magnet; and a magnetic body provided in the housing opposite a second surface of the drive magnet that is perpendicular to the first surface and that generates an attractive force with the drive magnet.

5. The camera actuator according to claim 4, wherein the drive magnet is mounted to the carrier with the first surface and the second surface both exposed to the outside.

6. The camera actuator according to claim 4, wherein the magnetic body has a shape that extends along a direction of movement of the carrier and is provided further outward than the plurality of rails.

7. The camera actuator according to claim 1, wherein the first rail is provided on one or more of a lower side of the carrier and a bottom surface side of the housing, the plurality of rails include a second rail provided on one or more of an opposite lower side of the carrier and an opposite bottom surface side of the housing in parallel with the first rail and having a plurality of the second rails on the same line.

8. The camera actuator according to claim 7, wherein the plurality of balls include: balls arranged in the first rail; and a single number of balls each having a diameter greater than that of the balls arranged in the first rail and arranged in the second rail. Further comprising: a first magnetic body provided in the carrier closer to the second rail than the first rail; and 9. The actuator for a camera according to claim 7, wherein a second magnetic body provided in the housing opposite the first magnetic body and generating an attractive force with the first magnetic body. Further comprising: a coil provided in the housing; and a drive magnet mounted to the carrier opposite the coil and provided closer to the second rail than the first rail.

10. The camera actuator according to claim 7, wherein 11. The camera actuator according to claim 8, wherein a virtual line connecting centers of the balls arranged in the second rail is within a thickness range of the drive magnet.

12. The camera actuator according to claim 1, wherein the carrier includes: a mount on which a lens is mounted; a first support portion provided on one side of the mount, having a shape that extends along an optical axis direction, and provided with a drive magnet; and a second support portion provided on the other side of the mount, having a shape that extends along the optical axis direction, and provided with a drive magnet. ​ ​ ​ A second support portion is provided on the other side of the mount and has a shape extending in the direction of the optical axis and a shape extending in the direction opposite to the extending direction of the first support portion.

13. The camera actuator according to claim 12, wherein The first rail is provided at a lower portion of the second support portion, The plurality of rails includes a second rail provided at a lower portion of the first support portion in parallel with the first rail, and a plurality of the second rails are provided on the same line.

Images