Sensor-driven actuator and camera module comprising the same

Abstract

The present invention relates to a sensor driving actuator, including: an image sensor; a substrate including a first region configured with the image sensor, a second region extending from the first region, and at least one slit between the first region and the second region; a base frame in which the substrate is seated; a sensor cover fastened to an upper portion of the first region; and a driving portion to move the sensor cover in rotation with reference to the base frame. The first region moves in rotation together with the sensor cover in rotation.

Description

Technical Field

[0001] This invention relates to a sensor-driven actuator and a camera module including the same. Background Technology

[0002] With the development of hardware technology for image processing and the increasing demands of users for image capture, functions such as autofocus (AF) and image stabilization (OIS) have been implemented not only in standalone camera devices but also in camera modules installed in mobile terminals such as mobile phones and smartphones.

[0003] The autofocus function refers to the function of adjusting the focal length between the carrier, which is equipped with a lens, and the subject by moving the carrier linearly along the optical axis, so as to generate a clear image in the image sensor (CMOS, CCD, etc.) provided at the back of the lens.

[0004] In addition, the shake correction function refers to the function of improving image sharpness by adaptively moving the carrier (frame) carrying the lens in the direction of compensating for lens shake when lens shake occurs due to hand shake.

[0005] One of the representative methods for achieving autofocus or OIS is as follows: by setting a magnet (coil) on a moving body (carrier) and a coil (magnet) on a fixed body (housing or other type of carrier, etc.), an electromagnetic force is generated between the coil and the magnet, so that the moving body moves along the optical axis or in a direction perpendicular to the optical axis.

[0006] On the other hand, recently, in order to meet higher user needs and achieve more diverse user convenience, mobile terminals are equipped with zoom lenses, which have specifications such as the ability to adjust the focal length differently and variably or to capture distant images.

[0007] Because such zoom lenses have a structure with multiple lenses or lens groups arranged side by side, or have a relatively long length of the lens itself relative to the optical axis, they require more space to be provided in the mobile terminal.

[0008] Recently, in order to organically incorporate the physical characteristics of such zoom lenses into the shape features of portable terminals, actuators or camera modules with physical structures that utilize a reflectometer disposed at the front end of the lens to refract light from the subject have been disclosed.

[0009] These actuators employing reflectometers achieve OIS (Optical Image Sensor) for camera shake by rotating a reflectometer that reflects the light from the subject toward the lens, using a single-axis or two-axis reference, rather than correcting and moving the lens based on camera shake.

[0010] However, when jitter caused by hand tremors occurs with reference to the x-axis and y-axis, the aforementioned actuator achieves OIS in the yaw and pitch directions by rotating the reflector in the direction that compensates for the motion. However, when jitter caused by hand tremors occurs with reference to the z-axis, there is a problem that OIS in the roll direction cannot be achieved. Summary of the Invention

[0011] The technical problem to be solved by the present invention

[0012] The present invention is proposed to solve the problems mentioned above in the background. Its purpose is to provide a sensor drive actuator and a camera module that can realize OIS in the roll direction by rotating the image sensor in the direction of compensating for the shaking caused by hand tremors or other factors when shaking occurs with reference to the z-axis.

[0013] Other objects and advantages of the present invention may be understood from the following description and will become more apparent from embodiments of the invention. Furthermore, the objects and advantages of the present invention may be achieved through the structures shown in the claims and combinations thereof.

[0014] Technical solution

[0015] To achieve the above objectives, the present invention provides a sensor driving actuator, comprising: an image sensor; a substrate having a first region of the image sensor, a second region extending from the first region, and at least one slit between the first region and the second region; a base frame on which the substrate is mounted; a sensor cover fastened to the upper part of the first region; and a driving unit for rotating the sensor cover relative to the base frame. The first region rotates together with the sensor cover.

[0016] The first region and the second region can be made of the same material or they can be made of different materials.

[0017] In addition, the substrate may include multiple bridge portions, and slits are disposed between the multiple bridge portions.

[0018] In addition, the sensor cover can rotate and move as multiple bridge sections twist.

[0019] In addition, multiple bridge sections can be constructed from flexible printed circuit boards (FPCBs) and have wiring that is electrically connected to the image sensor.

[0020] In addition, the drive unit may include: a plurality of first guides disposed on the base frame and including a first guide rail having an arc shape; a plurality of second guides disposed on the sensor cover corresponding to the first guides and including a second guide rail having an arc shape; and a ball disposed between the first guide rail and the second guide rail.

[0021] Furthermore, the curvature centers of the first and second guide rails can coincide with the rotation center of the image sensor.

[0022] Furthermore, multiple fastening grooves may be provided in the first region in such a way that multiple first guides abut against second guides.

[0023] Furthermore, when the sensor cover rotates, the first region rotates because multiple second guides can be engaged by multiple fastening slots.

[0024] In addition, multiple second guide sections can be provided at each corner of the sensor cover.

[0025] In addition, the drive unit may also include: a magnet disposed on the base frame and configured between the first guides facing each other; and a drive coil configured on the upper part of the magnet and generating magnetic force in the magnet to cause the sensor cover to rotate.

[0026] In addition, the drive unit may also include a magnetic yoke, which is disposed on the sensor cover and generates an attractive force on the magnet.

[0027] In addition, the present invention may also provide a camera module, the camera module comprising: the aforementioned sensor drive actuator; a lens assembly disposed on the upper part of the sensor drive actuator; a reflector disposed on the upper part of the lens assembly and reflecting or refracting light onto the lens assembly; and a reflector drive module for rotating and moving the reflector.

[0028] Beneficial effects

[0029] According to the present invention, when a tremor occurs with reference to the z-axis due to hand tremor or the like, OIS in the roll direction can be achieved by rotating the image sensor in the direction that compensates for the movement.

[0030] Furthermore, according to the present invention, multiple bridge portions are provided on both sides of the substrate on which the image sensor is disposed, so that the image sensor can be easily rotated and moved by twisting the multiple bridge portions.

[0031] The effects of the present invention are not limited to those described above, and those skilled in the art will clearly understand from the following description other effects not mentioned. Attached Figure Description

[0032] Figure 1 This is a perspective view of the combination of a sensor-driven actuator and a camera module according to an embodiment of the present invention.

[0033] Figure 2 This is an exploded perspective view of a sensor-driven actuator and a camera module according to an embodiment of the present invention.

[0034] Figure 3 This is a combined perspective view of a sensor-driven actuator according to an embodiment of the present invention.

[0035] Figure 4 and Figure 5 This is an exploded perspective view of a sensor-driven actuator according to an embodiment of the present invention.

[0036] Figure 6 It is along Figure 3 A sectional view cut off by the VI-VI line.

[0037] Figure 7 It is along Figure 3 A sectional view cut off along line VII-VII.

[0038] Figure 8 This is a diagram illustrating the operation of a sensor-driven actuator according to an embodiment of the present invention. Detailed Implementation

[0039] In the following, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in this specification and claims should not be construed as limited to their ordinary or dictionary meanings. Based on the principle that the inventors are able to properly define the concepts of the terms to best interpret their invention, they should be interpreted as meanings and concepts consistent with the technical spirit of the invention.

[0040] Therefore, it should be understood that the embodiments and structures shown in the accompanying drawings described in this specification are only one preferred embodiment of the present invention and do not represent all the technical ideas of the present invention. Therefore, various equivalents and modifications that can replace them may exist when this application is filed.

[0041] Figure 1 This is a perspective view of the combination of a sensor-driven actuator and a camera module according to an embodiment of the present invention. Figure 2 This is an exploded perspective view of a sensor-driven actuator and a camera module according to an embodiment of the present invention.

[0042] The sensor-driven actuator 300 of the present invention can be implemented as a separate device, but as Figure 1 As shown, it can be implemented as a camera module 1000 together with the reflectometer driving module 100 and the lens driving module 200.

[0043] According to the present invention, the light of the subject does not directly enter the lens assembly 210, but enters the lens assembly 210 after the path of the light is changed (refracted, reflected, etc.) by the reflector 110 provided in the reflector drive module 100.

[0044] like Figure 2 As shown, the path of light incident from the outside is Z1, and the path of light incident from the outside after being refracted or reflected by the reflector 110 and then entering the lens assembly 210 is Z. In the following description, the Z-axis direction, which is the direction in which light enters the lens assembly 210, will be referred to as the optical axis or optical axis direction.

[0045] The reflectometer driving module 100 can be positioned in front of or above the lens driving module 200 (based on the optical axis direction) and performs the function of reflecting or refracting the light path (Z1) of the subject along the optical axis path (Z). In this way, the light reflected or refracted along the optical axis direction passes through the lens assembly 210 provided in the lens driving module 200 and enters the image sensor 310, such as CMOS or CCD.

[0046] The reflectometer drive module 100 may include a reflectometer 210, which may be composed of one or a combination of a mirror or a prism. The reflectometer 210 may be implemented by various components capable of altering the direction of light incident from the outside along the optical axis, but is preferably made of glass to improve optical performance.

[0047] The camera module 1000 of the present invention, including the reflectometer driving module 100, is configured to direct light toward the lens via the path of refracted light, so that the device itself can be positioned in the length direction of the portable terminal rather than in the thickness direction of the portable terminal. Therefore, the miniaturization or thinning of the portable terminal can be optimized without increasing the thickness of the portable terminal.

[0048] According to the embodiment, the reflectometer 110 can also be configured to rotate by a driving means for generating magnetic force (e.g., a magnet and a coil). In this way, when the reflectometer 110 moves or rotates, the light of the subject reflected (refracted) by the reflectometer 110 moves and enters the lens and imaging element, thus enabling OIS for hand shakiness.

[0049] That is, when a shaking occurs with the X-axis as a reference due to hand tremors, the reflectometer drive module 100 of the present invention causes the reflectometer 110 to rotate and move in the direction of compensating for its movement, thereby achieving OIS in the first direction.

[0050] Furthermore, the reflectometer driving module 100 of the present invention diversifies the frame structure so that the frame structure moves in all directions, and the reflectometer 110 rotates and moves with the Y-axis as a reference through the relative movement of the diversified frame structure, thereby realizing OIS in the second direction. At the same time, OIS in the first and second directions can also be realized in combination.

[0051] The light from the subject reflected by the reflectometer drive module 100 is incident on the lens assembly 210 located inside the lens drive module 200. During this process, the position of the lens assembly 210 (based on the optical axis direction) is adjusted in combination to achieve functions such as zoom or autofocus.

[0052] The lens drive module 200 achieves autofocus (AF) or zoom by linearly moving each of the plurality of carriers carrying the lens assembly 210 along the optical axis.

[0053] The lens assembly 210 can be a single lens or a zoom lens that may include optical components (e.g., multiple lenses or lens groups or prisms, mirrors, etc.) inside. When the lens assembly 210 is formed from a zoom lens or a zoom lens barrel, it can be formed in a shape that extends along the vertical length direction (Z-axis direction).

[0054] An image sensor 310 (e.g., CCD, CMOS, etc.) for converting optical signals into electrical signals can be provided at the rear end of the lens assembly 210 with the optical axis as a reference, and a filter for blocking or transmitting optical signals of a specific wavelength band can also be provided.

[0055] The sensor-driven actuator 300 may include an image sensor 310 internally, and when a tremor occurs with reference to the z-axis due to hand tremor or the like, the image sensor 310 is rotated and moved in the direction that compensates for its movement, thereby achieving OIS in the third direction (roll direction).

[0056] Figure 3 This is a combined perspective view of a sensor-driven actuator according to an embodiment of the present invention. Figure 4 and Figure 5 This is an exploded perspective view of a sensor-driven actuator according to an embodiment of the present invention. Furthermore, Figure 6 It is along Figure 3 A sectional view cut off by the VI-VI line. Figure 7 It is along Figure 3 A sectional view cut off along line VII-VII.

[0057] Below, refer to Figures 3 to 6 The structure of the sensor-driven actuator according to an embodiment of the present invention will be described in detail.

[0058] According to an embodiment of the present invention, the sensor drive actuator 300 can be configured to include an image sensor 310, a substrate 330, a base frame 340, a sensor cover 350, and a drive unit 360.

[0059] The image sensor 310 may be a CCD, CMOS, or other sensor that converts light signals incident from the lens assembly 210 into electrical signals, but is not limited to these.

[0060] The substrate 330 may include a first region 320 on which an image sensor is disposed, a second region 332 extending from the first region 320, and at least one slit 333 between the first region 320 and the second region 332.

[0061] The first region 320 and the second region 332 can be made of the same material or different materials. For example, the first region 320 can be a hard printed circuit board (HPCB), and the second region 330 can be a flexible printed circuit board (FPCB).

[0062] Furthermore, the first region 320 can be formed by stacking multiple FPCBs. For example, by integrally forming the first region 320 and the second region 332 into an FPCB, and then stacking multiple FPCBs only in the second region 330, the first region 320 can be made of HPCB and the second region 332 can be made of FPCB.

[0063] The substrate 330 may include a plurality of bridge portions 331, and a slit 333 is disposed between the plurality of bridge portions 331.

[0064] The plurality of bridge sections 331 are made of FPCB, and wiring (not shown) electrically connected to the image sensor 310 can be formed in the plurality of bridge sections 331. Furthermore, the second region 332 can be connected to the wiring, and circuitry (not shown) for processing electrical signals of the image sensor 310 can be formed therein.

[0065] As described above, since the substrate 330 includes slits 333 and the plurality of bridges 331 are made of FP CB, it can be torsional by external force. This will be explained in detail later.

[0066] The base frame 340 may include a mounting groove 341 for mounting the substrate 330, and when the substrate 330 is mounted in the mounting groove 341, the sensor cover 350 is fastened to the upper part of the first region 320.

[0067] The sensor cover 350 may have an opening 351 in the center to allow light signals to enter the image sensor 310 from the lens assembly 210, and the image sensor 310 may be exposed to the outside through the opening 351.

[0068] The drive unit 360 can rotate the sensor cover 350 around the base frame 340.

[0069] In this regard, from a relative point of view with the sensor cover 350 as the reference, the base frame 340 is equivalent to a fixed body.

[0070] Specifically, the drive unit 360 may be configured to include a plurality of first guides 361, second guides 362, balls 363, magnets 364, drive coils 365 and yokes 366.

[0071] The first guide section 361 may be multiple and disposed inside the base frame 340, and includes a first guide rail 361a having an arc shape.

[0072] The second guide portion 362 may have multiple portions and is disposed inside the sensor cover 350 corresponding to the first guide portion, and includes a second guide rail 362a having an arc shape.

[0073] Ball 363 is respectively disposed between the first guide rail 361a and the second guide rail 362a, and can roll (or rotate) between them.

[0074] The second guide portion 362 can be configured to protrude downward from each corner of the sensor cover 350, and the plurality of first guide portions 361 can be configured to protrude upward from the position of the base frame 340 corresponding to the second guide portion 362.

[0075] The first region 320 may be provided with a plurality of fastening grooves 321 in such a way that the first guide 361 abuts against the second guide 362.

[0076] The fastening groove 321 can be formed by cutting in the first region 320 with a shape corresponding to the first guide 361 and the second guide 362.

[0077] Therefore, if the substrate 330 is placed in the mounting groove 341 and the sensor cover 350 is fastened to the upper part of the first region 320, the first guide portion 361 and the second guide portion 362 abut against each other and the ball 363 is accommodated between the first guide rail 361a and the second guide rail 362a.

[0078] Magnets 364 are disposed inside the base frame 340 and can be configured between the first guides 361 facing each other.

[0079] The drive coil 365 is disposed on the upper part of the magnet 364 and generates a magnetic force in the magnet 364, thereby causing the sensor cover 350 to rotate and move.

[0080] For this purpose, the base frame 340 may have a first mounting groove 342 formed between the first guide portions 361 facing each other for mounting the magnet 364 and the drive coil 365.

[0081] The magnetic yoke 366 is disposed inside the sensor cover 350 corresponding to the magnet 364, and can be made of a magnetic material such as metal to generate an attractive force on the magnet 364. For this purpose, the sensor cover 350 can form a second mounting groove 352 for mounting the magnetic yoke 366 between the second guide portions 362 facing each other.

[0082] In this way, the base frame 340 with magnet 364 is pulled in the direction of the magnetic yoke 366 (i.e., the direction of sensor cover 350) by the attraction generated between the magnetic yoke 366 and magnet 364, so that the base frame 340 and ball 363 are closely attached to each other and the ball 363 and sensor cover 350.

[0083] Furthermore, when power to the drive coil 365 is stopped, the yoke 366 can also perform the function of restoring the sensor cover 350 to its original position. In addition, to improve the efficiency of the function control of the rotational movement of the sensor cover 350, the yoke 366 is preferably configured such that its center coincides with the center of the magnet 364, and its shape is the same as that of the magnet 364.

[0084] Figure 8 This is a diagram illustrating the operation of a sensor-driven actuator according to an embodiment of the present invention.

[0085] Reference Figure 8 In (a) and (b), when the drive coil 365 generates magnetic force in the magnet 364 in the first rotation direction (e.g., counterclockwise), the sensor cover 350 can rotate in the first rotation direction by the rolling motion of the ball 363 housed in the first guide rail 361a and the second guide rail 362a and the torsion of the plurality of bridge portions 331.

[0086] At this time, the first region 320 rotates and moves together with the sensor cover 350, while the second region 332 is fixed to the base frame 340.

[0087] That is, when the sensor cover 350 rotates, the first region 320 and the image sensor 310 can rotate together because the multiple second guides 362 are locked by the multiple fastening grooves 321.

[0088] Similarly, refer to Figure 8 In (a) and (c), when the drive coil 365 generates magnetic force in the magnet 364 in a second rotation direction (e.g., clockwise) opposite to the first rotation direction, the sensor cover 350 can rotate in the second rotation direction by the rolling motion of the ball 363 housed in the first guide rail 361a and the second guide rail 362a and the torsion of the plurality of bridge portions 331.

[0089] At this time, the first region 320 rotates and moves together with the sensor cover 350, while the second region 332 is fixed to the base frame 340.

[0090] That is, when the sensor cover 350 rotates and moves, the first region 320 and the image sensor 310 rotate and move together because the multiple second guides 362 are locked by the multiple fastening grooves 321.

[0091] On the other hand, when power to the drive coil 365 is stopped, the sensor cover 350 and the image sensor 310 return to their original positions by the attraction of the yoke 366 and the magnet 364.

[0092] In this way, when a tremor occurs with reference to the z-axis due to hand shaking, the sensor drive actuator 300 according to the embodiment of the present invention can rotate the image sensor 310 in the direction of compensating for its movement, thereby realizing OIS in the third direction (roll direction).

[0093] Refer again Figure 4 The curvature center CG of the first guide rail 361a and the second guide rail 362a coincides with the rotation center CS of the image sensor 310.

[0094] On the other hand, when the curvature center CG of the first guide rail 361a and the second guide rail 362a does not coincide with the rotation center CS of the image sensor 310, even if the same driving force is applied to the magnet 364, the amount of rotational movement of the image sensor 310 will be different depending on the position of the image sensor 310. In this way, there is a problem that a separate compensation algorithm needs to be applied to compensate for the different amount of rotational movement at each position.

[0095] However, in the sensor drive actuator 300 according to an embodiment of the present invention, the curvature center CG of the first guide rail 361a and the second guide rail 362a coincides with the rotation center CS of the image sensor 310. Therefore, for the same driving force, the rotational movement of the image sensor 310 is the same regardless of the position of the image sensor 310, thus eliminating the need for the separate compensation algorithm.

[0096] On the other hand, preferably, the curvature center CG of the first guide rail 361a and the second guide rail 362a coincides with the rotation center CS of the image sensor 310, but it is not limited to this. Even if the center part is offset due to manufacturing tolerances, it is still within the scope of the present invention.

[0097] While the present invention has been described above with reference to limited embodiments and accompanying drawings, the present invention is not limited thereto. Of course, those skilled in the art can make various modifications and variations within the scope of the technical concept of the present invention and the equivalents of the appended claims.

[0098] In the above description of the present invention, terms such as "first" and "second" are merely instrumental conceptual terms used to relatively distinguish each component element, and therefore should be understood as not being terms used to indicate a specific order, priority, etc.

[0099] In describing the present invention and illustrating its embodiments, the accompanying drawings and the like may be shown in a slightly exaggerated manner to emphasize or highlight the technical content of the invention. However, in view of the foregoing and the matters shown in the drawings, it should be understood that various types of modified application examples are obviously possible to those skilled in the art.

[0100] Industrial applicability

[0101] The sensor-driven actuator according to the present invention can be applied to a standalone camera device, and can also be applied to a camera module installed in a mobile terminal such as a mobile phone or smartphone.

Claims

1. A sensor-driven actuator, wherein, include: Image sensor; The substrate includes a first region where the image sensor is disposed, a second region extending from the first region, and at least one slit between the first region and the second region. The basic frame, on which the substrate is mounted; The sensor cover is fastened to the upper part of the first region; as well as The drive unit rotates and moves the sensor cover based on the base frame. The first region rotates and moves together with the sensor cover. The substrate includes a plurality of bridge portions, and the slit is disposed between the plurality of bridge portions. The sensor cover rotates and moves as the plurality of bridge sections twist.

2. The sensor-driven actuator according to claim 1, wherein, The first region and the second region may be made of the same material or different materials.

3. The sensor-driven actuator according to claim 1, wherein, The plurality of bridge sections are made of flexible printed circuit boards and have wiring that is electrically connected to the image sensor.

4. The sensor-driven actuator according to claim 1, wherein, The drive unit includes: Multiple first guides are disposed on the base frame and include first guide rails having an arc shape; Multiple second guide portions, corresponding to the first guide portions, are disposed on the sensor cover and include a second guide rail having an arcuate shape; and The ball is positioned between the first guide rail and the second guide rail.

5. The sensor-driven actuator according to claim 4, wherein, The curvature centers of the first and second guide rails coincide with the rotation center of the image sensor.

6. The sensor-driven actuator according to claim 4, wherein, In the first region, a plurality of fastening grooves are provided in such a manner that the plurality of first guides and second guides abut against each other.

7. The sensor-driven actuator according to claim 6, wherein, When the sensor cover rotates, the first region can rotate because the plurality of second guides are locked by the plurality of fastening grooves.

8. The sensor-driven actuator according to claim 4, wherein, The plurality of second guides are disposed at each corner of the sensor cover.

9. The sensor-driven actuator according to claim 8, wherein, The drive unit also includes: Magnets are disposed on the base frame and configured between the first guides that are opposite each other; and A drive coil is disposed on the upper part of the magnet and generates magnetic force in the magnet, enabling the sensor cover to rotate and move.

10. The sensor-driven actuator according to claim 9, wherein, The drive unit further includes a magnetic yoke, which is disposed on the sensor cover and exerts an attractive force on the magnet.

11. A camera module, in, include: The sensor-driven actuator according to any one of claims 1 to 10; A lens assembly is disposed on the upper part of the sensor drive actuator; A reflectometer, disposed on the upper part of the lens assembly, reflects or refracts light onto the lens assembly; and A reflectometer drive module is used to rotate and move the reflectometer.

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