KR20150051098A - Ois camera module - Google Patents

Abstract

An optical image stabilizer (OIS) camera module according to an embodiment of the present invention consists of: a fixed unit which includes a main body facing an image sensor; a movement unit which is installed in ways for a lens bobbin unit on which the lens is mounted to move in the direction of the optical axis and moves perpendicularly to the optical axis against the fixed unit; and a movement unit support tool which supports the movement unit horizontally against the fixed unit and fixes in one place the movement unit in the direction of the optical axis against the fixed unit.

Description

OIS camera module {OIS CAMERA MODULE}

The present invention relates to a camera module for photographing a subject, and more particularly to an OIS camera module provided with optical image stabilization means.

A camera module having an auto focusing function that automatically adjusts the focus of a subject when shooting a subject is widely applied to mobile devices such as a mobile phone or a tablet PC as well as a general digital camera.

Recently, a camera module employing a camera shake prevention means has been introduced not only in the auto focus (AF) function but also in the camera. The anti-shake means can be largely classified into an electronic type and an optical type. An electronic image stabilizer (EIS) is an image processing method of an image signal outputted from an image sensor. Optical Image Stabilizer (OIS) is a system that mechanically adjusts the position and angle of an image sensor or lens optical system.

Since the camera module with OIS device is complicated in structure and bulky, it needs to overcome many technical difficulties to be adopted for mobile devices.

Korean Patent Application Publication No. 2007-0065195 discloses a device for compensating for phase shift, but it is structurally difficult to miniaturize for a mobile device such as a smart phone.

Korean Patent Publication No. 2007-0065195

The present invention relates to an OIS camera module that implements an OIS (Optical Image Stabilizer) function and is optimized for a mobile device having a reduced thickness or volume.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the precise forms disclosed. Other objects, which will be apparent to those skilled in the art, It will be possible.

The OIS camera module of the present invention includes: a fixing unit including a main body facing an image sensor; A moving unit which is installed movably in a direction of an optical axis and in which a lens bobbin to which a lens is mounted is moved in a horizontal direction perpendicular to the optical axis with respect to the fixing unit; A moving unit supporting means for movably supporting the moving unit with respect to the fixing unit in the horizontal direction and restricting the moving unit with respect to the fixing unit at a predetermined position in the optical axis direction; .

The OIS camera module of the present invention is optimized for a mobile device, and corresponds to a lens shift method, and optically corrects image deterioration as well as electronic correction. Therefore, even when the camera is shaken when the exposure time is prolonged, high-quality shooting can be performed without deterioration of the image. In addition, high-quality shooting can be performed even in a low-illuminance environment.

The OIS camera module of the present invention can constitute an apparatus by efficiently using a space by using a permanent magnet as an AF actuator and an OIS actuator in common.

The sensor unit of the OIS camera module of the present invention is installed at a position not affected by the magnetic field of the AF coil and the OIS coil, thereby preventing noise due to the magnetic field generated in the AF coil and the OIS coil.

The ball of the present invention minimizes the friction during movement of the moving unit to reduce the OIS driving power and supports the moving unit freely movably only in the horizontal direction while maintaining a constant height with respect to the optical axis,

The ball of the present invention can reduce the frictional load ideally to zero when driving the OIS to reduce the driving power and reduce the positional error so that the lens bobbin portion can be moved in the direction of the optical axis A skew that is tilted with respect to the vehicle can be prevented.

1 is a perspective view of an OIS camera module of the present invention.
2 is an exploded perspective view of the OIS camera module of the present invention.
3 is a partial perspective view of a part of the housing of the present invention.
4 is a side sectional view schematically showing the ball and guide structure of the present invention.
5 is a side sectional view schematically showing a pressing member and a ball according to the present invention.
6 is a side sectional view schematically showing the suction magnet of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The sizes and shapes of the components shown in the drawings may be exaggerated for clarity and convenience. In addition, terms defined in consideration of the configuration and operation of the present invention may be changed according to the intention or custom of the user, the operator. Definitions of these terms should be based on the content of this specification.

The construction and operation of the OIS camera module of the present invention will be described in detail with reference to FIGS. 1 to 6. FIG.

The OIS camera module of the present invention includes a fixing unit 400, a moving unit 300, and a moving unit supporting means.

One side of an optical axis on which light is incident is referred to as a first side, and the other side of an optical axis through which light is emitted in the direction of an image sensor (not shown) is defined as a second side. In addition, a first axis, a second axis and a third axis which define an xyz orthogonal coordinate system are defined. The optical axis or the first axis corresponds to the z axis, the second axis perpendicular to the optical axis corresponds to the x axis, and the third axis perpendicular to the optical axis corresponds to the y axis.

In the present invention, 'horizontal direction' refers to an x-axis direction or a y-axis direction which is a direction perpendicular to an optical axis. This is extended to define a horizontal direction, which is not perpendicular to the optical axis, but which is directed to the side radial direction of the optical axis, but is also inclined to the optical axis.

If camera shake occurs during camera shooting, it is difficult to shoot an accurate image. There are camera tilting method and lens shift method as means for optically correcting the camera shake.

The camera tilting method tilts the camera module itself including the lens together with the image sensor so that a virtual axis connecting the subject and the center of the OIS camera module is aligned with the optical axis on which the actual light is incident. However, the camera tilting method has a disadvantage that the bulky and bulky power consumption for tilting driving becomes large. The camera tilting method is simplified so that the image sensor is kept in a still state and the lens is moved in the horizontal direction with respect to the optical axis.

The OIS camera module of the present invention is optimized for a mobile device, and corresponds to a lens shift method. Although not described in detail, an electronic correction (EIS) is also possible and optically corrects deterioration of an image. Therefore, even when the exposure time is long and the camera is shaken, high-quality shooting can be performed without deterioration of the image. In addition, high-quality shooting can be performed even in a low-illuminance environment.

In the present invention, the lens must be able to move in the optical axis direction in order to perform the auto focus (AF) function. On the other hand, in order to perform optical correction (OIS), the lens must be able to move in the horizontal direction perpendicular to the optical axis. The OIS camera module of the present invention can perform the OIS function independently of the AF function regardless of whether the AF function is operated or not.

The main body 410 faces the image sensor and forms an external appearance of the OIS camera module, provides an assembly base when an OIS camera module is assembled to an external device such as a mobile device, and supports a load or an external force. The case 100 corresponds to a cover for covering the main body 410. Fig. The case 100 and the housing 310 are shown in a cut-away state. The fixing unit 400 includes at least one of a main body 410 and a case 100.

It is possible to define the mobile unit 300, which is an element to be moved with respect to the main body 410 which is a fixed element. The moving unit 300 includes a housing 310, a lens bobbin 330, and an AF actuator.

The movable unit 300 is provided with a lens bobbin 330 on which the lens is mounted so as to be movable in the direction of the optical axis and the movable unit 300 is movable in the direction perpendicular to the optical axis And is moved in one horizontal direction.

The lens bobbin 330 can move in the horizontal direction as well as in the optical axis direction to where the lens is mounted. The optical axis direction driving force of the lens bobbin portion 330 is provided by the AF actuator, and the horizontal direction driving force is provided by the OIS actuator.

In auto focusing, the lens bobbin portion 330 is moved in the optical axis direction with respect to the housing 310. The optical axis direction driving force of the lens bobbin 330 is generated by the AF actuator, and the AF actuator may be independent of whether or not the OIS actuator is operated.

The housing 310 may be positioned between the lens bobbin 330 and the body 410. A lens bobbin 330 is positioned inside the housing 310. The lens bobbin 330 may be coupled to the housing 310 together with the housing 310 even if the lens bobbin 330 is moved in the optical axis direction for the AF function when the housing 310 is moved in the horizontal direction for OIS operation. As shown in FIG.

The housing 310 can be moved in the horizontal direction with respect to the main body 410 at the time of optical image stabilization. The horizontal driving force of the housing 310 is generated by the OIS actuator, and may be independent of the operation of the AF actuator. The housing 310 may have a magnet fixing portion 314 on which the driving magnets 340a and 340b are installed.

The AF actuator may include driving magnets 340a and 340b mounted on the housing 310 and an AF coil 350 mounted on the lens bob 330. [ The AF actuator generates an electromagnetic force for driving the lens bobbin portion 330 in the optical axis direction. The AF actuator generates driving force in the optical axis direction of the lens bobbin portion 330 with respect to the movable unit 300 during the auto focusing operation.

The OIS actuator may include driving magnets 340a and 340b installed in the housing 310 and OIS coils 450a and 450b installed in the main body 410. [ The OIS actuator generates an electromagnetic force for driving the housing 310 in the horizontal direction. The OIS actuator generates a horizontal driving force of the mobile unit 300 with respect to the fixing unit 400 when optical image stabilization is performed.

The driving magnets 340a and 340b of the AF actuator and the driving magnets 340a and 340b of the OIS actuator may be separate permanent magnets fixed to the inside of the housing 310 or common permanent magnets. The embodiment which is a common permanent magnet can avoid the distortion of the electromagnetic force due to the interference of the magnetic force and save the installation space compared with the embodiment in which the magnet of the AF actuator and the magnet of the OIS actuator are provided separately, It is possible to reduce the inertia of the housing 310, which is a part of the housing 310, and reduce the power consumption of the actuator.

The driving magnets 340a and 340b may include a pair of first driving magnets 340a facing each other in the first axis direction and a pair of second driving magnets 340b facing each other in the second axis direction have.

In one embodiment, the side surfaces of the driving magnets 340a and 340b face the AF coil 350 in a radial direction along the outer periphery of the lens bobbin portion 330. The upper surface or the rear surface of the driving magnets 340a and 340b may face the OIS coils 450a and 450b along the optical axis direction.

The OIS coils 450a and 450b include a pair of first OIS coils 450a facing the pair of first driving magnets 340a and a pair of second OIS coils 450b facing the second driving magnets 340b. (450b). The plurality of OIS coils 450a and 450b may be a pattern formed on the OIS coil substrate 460. Therefore, the thickness of the coil can be reduced and the number of assembling steps can be reduced.

Means for measuring the horizontal displacement of the housing 310 is needed for accurate feedback control of the OIS actuator. For this, the sensor units 210a and 210b are mounted. The sensor units 210a and 210b are installed in the main body 410 and are in a fixed position and sense a change in the magnetic force of the driving magnets 340a and 340b moved during OIS driving. Since the magnetic force variation of the driving magnets 340a and 340b is proportional to the horizontal displacement of the housing 310, the signals measured by the sensor units 210a and 210b are inputted as feedback signals of the OIS coils 450a and 450b.

The sensor units 210a and 210b sense the amount of movement of the first driving magnet 340a to independently sense the movement amounts of the first and second axes and feed back to the first OIS coil 450a. And a second sensor unit 210b that senses the amount of movement of the second driving magnet 340b and feeds back the sensed amount to the second OIS coil 450b.

A first sensor portion 210a facing the first driving magnet 340a and a second sensor portion 210b facing the second driving magnet 340b are mounted and the first sensor portion 210a And a second sensor unit 210b are mounted on the main body 410 and patterns for inputting and outputting power and signals are formed on the sensor unit holder 200. [

Since the lens bobbin 330 needs to be installed in the housing 310 so as to be movable on the optical axis, the lens bobbin 330 can be elastically supported in the optical axis direction or the self- Is required. As the elastic supporting means of the lens bobbin portion 330, a first AF suspension 321 and a second suspension are provided along the optical axis direction. The reason why the pair of AF suspensions 321 and 322 are provided in the direction of the optical axis is to prevent the skew of the lens bobbin portion 330.

In one embodiment, the AF suspensions 321 and 322 are made of a metal plate having elasticity, and a part of the metal plate may be cut off to facilitate elastic deformation in the optical axis direction. It is preferable that the AF suspensions 321 and 322 are provided in such a shape as to allow elastic deformation in the first axial direction but inhibit movement of the lens bobbins 330 along the second and third axial directions. This is to match the optical center of the lens bob 330 with the optical center of the initially set OIS camera module with respect to AF drive displacement, self deflection or vibration / impact displacement.

Meanwhile, since the housing 310 is movably installed to the body 410, a means for supporting the housing 310 in a horizontal direction with respect to the body 410 is needed. Also, the weight of the housing 310 should be supported. Here, 'self weight' can be various forms such as a vector of an optical axis direction, a vector of a horizontal direction, a vector of an optical axis and a component of a horizontal direction according to the posture of the OIS camera module. In this embodiment, a mobile unit support means is provided.

The moving unit supporting means can support the moving unit 300 in the horizontal direction so as to be movable with respect to the fixing unit 400. [

In one embodiment, the movable unit support means includes a ball 900 interposed between the fixed unit 400 and the movable unit 300. Since the ball 900 is brought into rolling contact with the fixing unit 400 and the moving unit 300 respectively, it is possible to minimize the frictional load of the moving unit 300 during OIS driving and to prevent the movement of the moving unit 300 in the optical axis direction have.

As a means for preventing the ball 900 from being dislocated from a predetermined position or for keeping the movement locus of the ball 900 within a desired range, a guide means may be provided.

In one embodiment, the guiding means comprises a first insertion groove 390 defining a rolling contact surface of the ball 900 and the moving unit 300, and a second insertion groove 390 defining a rolling contact surface of the ball 900 and the fixing unit 400 And includes a second insertion groove 490. The first insertion groove 390 and the second insertion groove 490 in which the ball 900 is inserted may be provided in the fixing unit 400 and the moving unit 300, respectively.

It is preferable that the opening of the first insertion groove 390 and the opening of the second insertion groove 490 are opposed along the optical axis so that the assembling property of the ball 900 is improved and the state of the ball 900 is changed from outside Can be made observable.

On the other hand, the moving unit support means preferably restrains the moving unit 300 with respect to the fixing unit 400 at a predetermined position in the optical axis direction. According to this embodiment, the OIS driving and the AF driving can be controlled independently of each other without being affected by each other, or skew in which the weight of the moving unit 300 is supported or the moving unit 300 is tilted with respect to the optical axis is prevented . The moving unit support means is provided to secure the self-weight support or shock / vibration responsive force of the moved component while permitting the AF drive displacement and the OIS drive displacement of the movable unit 300, the housing 310 or the lens bob 330 .

The rolling contact surface of the first insertion groove 390 and the rolling contact surface of the second insertion groove 490 are formed perpendicular to the optical axis so that the mobile unit 300 is accurately guided in the horizontal direction .

On the other hand, it is possible to prevent the ball 900 from moving at a predetermined position during OIS driving or vibration / impact, or to prevent the moving unit 300 from moving in a horizontal direction to other parts such as the case 100, Position limiting means of the mobile unit 300 for preventing contact interference is provided.

4, at least a part of the first insertion groove 390 or at least a part of the second insertion groove 490 protrudes in a direction to enclose the ball 900. As shown in Fig. It is preferable that the moving amount of the moving unit 300 in the horizontal direction is limited within a certain range due to contact interference between the protruded portion and the ball 900. [

On the other hand, the suction unit is provided to prevent the fixing unit 400 and the moving unit 300 from being separated from each other in the optical axis direction by self weight or external force. The suction means can suck the moving unit 300 in a direction approaching the fixing unit 400 along the optical axis direction.

The moving unit 300 is provided with the driving magnets 340a and 340b for generating the moving force in the optical axis direction or the moving force in the horizontal direction of the lens bobbin 330, A suction yoke 420 or a suction magnet 430 is disposed. The moving unit 300 can be sucked toward the fixing unit 400 along the optical axis direction by the attracting force of the suction yoke 420 or the suction magnet 430 with respect to the driving magnets 340a and 340b.

In one embodiment, the suction means generates a magnetic force to connect the movable unit 300 to the fixed unit 400 in the direction of the optical axis. The movement of the mobile unit 300 in the direction of the optical axis is prevented.

On the other hand, for uniform elastic support and installation space saving, the movable unit support means can be arranged in a plurality of axially symmetrical positions with respect to the optical axis. In one embodiment, the moving unit support means is disposed at a vertex portion of the inner space formed by the main body 410. The moving unit support means may be disposed concentrically on one side or the other side of the lens bobbin portion 330 along the optical axis. Referring to the illustrated example, four balls 900 are arranged in the axisymmetric position or arranged at the second side position with respect to the lens bobbin 330, and arranged at the vertex portion of the inner space of the main body 410, Can be reduced.

On the other hand, centering means for returning the mobile unit 300 to the initial position may be provided in order to achieve various purposes such as when the OIS actuator is turned off or to improve the OIS control convenience.

In one embodiment, the centering means may apply a horizontal external force to the moving unit 300 so as to converge the moving unit 300 to the initial position x0 in the horizontal direction.

5, a non-contact type pressing means (not shown) such as a pressing member 800 or a permanent magnet for returning or elastically pressing the movable unit 300 to the horizontal direction with respect to the fixing unit 400, Can be provided.

6, the driving magnets 340a and 340b are provided in the moving unit 300 and the suction magnets 430 are disposed in the fixing unit 400. In this embodiment,

The magnetic forces MC1 and MC2 of the driving magnets 340a and 340b and the magnetic attraction centers MC1 and MC2 of the driving magnets 340 and 340 and the driving magnets MC1 and MC2 of the driving unit 300 are shifted by an OIS driving force or other external force, The attracting force acting between the driving magnets 340a and 340b and the attracting magnet 430 can function to make the center of the moving unit 300 approach the optical axis. The driving magnets 340a and 340b and the suction magnet 430 can function as centering means of the moving unit 300 because they interact with attraction forces in the direction in which the magnetic force centers MC1 and MC2 coincide with each other.

The suction magnet 430 can be moved to the moving unit 300 so that the horizontal magnetic force center point MC1 of the driving magnets 340a and 340b and the horizontal magnetic force center point MC2 of the suction magnet 430 coincide with each other Pull it. Accordingly, the optical center of the mobile unit 300 can be aligned in position with respect to the optical axis, or the mobile unit 300 can be converged to the initial position x0 in the horizontal direction.

On the other hand, if the moving unit support means having at least three points of support as in the case of the ball 900 of the present invention is provided, the skew in which the lens bobbin portion 330 tilts with respect to the optical axis is fundamentally interrupted. The arrangement of the balls 900 that limit the position in the optical axis direction essentially prevents the skew in which the movable unit 300, the housing 310, or the lens bob 330 is inclined with respect to the optical axis.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. Accordingly, the true scope of the present invention should be determined by the following claims.

100 ... case 200 ... sensor holder
210a ... first sensor unit 210b ... second sensor unit
300 ... mobile unit 310 ... housing
314 ... magnet fixing portion 321 ... first AF suspension
322 ... second AF suspension 330 ... lens bobbin portion
340a ... First driving magnet 340b ... Second driving magnet
350 ... AF coil 390 ... first insertion groove
400 ... fixing unit 410 ... body
420 ... suction yoke 430 ... suction magnet
450a ... First OIS coil 450b ... Second OIS coil
460 ... OIS coil substrate 490 ... second insertion groove
800 ... pressing member 900 ... ball

Claims (14)

A fixing unit including a main body facing the image sensor;
A moving unit which is installed movably in a direction of an optical axis and in which a lens bobbin to which a lens is mounted is moved in a horizontal direction perpendicular to the optical axis with respect to the fixing unit;
A moving unit supporting means for supporting the moving unit movably in the horizontal direction with respect to the fixing unit; And an OIS camera module. The method according to claim 1,
An AF actuator including an AF coil and a driving magnet respectively provided in the lens bobbin portion and the moving unit and generating driving force in the optical axis direction of the lens bobbin portion with respect to the moving unit during an auto focusing operation;
An OIS actuator including an OIS coil and a driving magnet respectively provided in the fixing unit and the moving unit, the OIS actuator generating the horizontal driving force of the moving unit with respect to the fixing unit during optical camera shake correction; Lt; / RTI >
Wherein the driving magnet of the AF actuator and the driving magnet of the OIS actuator are the same. 3. The method of claim 2,
The side surface of the driving magnet faces the AF coil in a radial direction along the outer periphery of the lens bobbin portion,
Wherein an upper surface or a rear surface of the driving magnet faces the OIS coil along the optical axis direction. The method according to claim 1,
Wherein the moving unit support means restrains the moving unit with respect to the fixing unit at a predetermined position in the optical axis direction. The method according to claim 1,
Wherein the moving unit support means comprises:
And a ball interposed between the fixed unit and the movable unit. The method according to claim 1,
At least one ball rollingly contacting the fixed unit and the movable unit is provided,
Wherein the first insertion groove forming the rolling contact surface of the ball and the moving unit and the second insertion groove forming the rolling contact surface of the ball and the fixing unit are provided. The method according to claim 6,
The opening of the first insertion groove and the opening of the second insertion groove face each other along the optical axis,
Wherein the rolling contact surface of the first insertion groove and the rolling contact surface of the second insertion groove are formed perpendicular to the optical axis so that the moving unit is guided in the horizontal direction when the optical camera shake correction is performed. The method according to claim 1,
The first insertion groove and the second insertion groove into which the ball is inserted are respectively provided in the fixing unit and the moving unit,
At least a part of the first insertion groove or at least a part of the second insertion groove protrudes in a direction of wrapping the ball,
Wherein the horizontal movement amount of the moving unit is limited within a certain range by contact interference between the protruding portion and the ball. The method according to claim 1,
Wherein the moving unit support means is disposed at a vertex portion of the inner space formed by the main body and is integrally disposed on one side or the other side of the lens bobbin portion along the optical axis. The method according to claim 1,
Suction means for sucking the moving unit in a direction approaching the fixing unit along the optical axis direction; And an OIS camera module. The method according to claim 1,
A driving magnet for generating the moving force in the optical axis direction or the moving force in the horizontal direction of the lens bobbin portion is provided in the moving unit,
A suction yoke or a suction magnet is disposed in the fixing unit,
Wherein the moving unit is sucked in a direction in which the moving unit is approached to the fixing unit along the optical axis direction by attraction of the suction yoke or the suction magnet to the driving magnet. The method according to claim 1,
A centering means for converging the moving unit to an initial position in the horizontal direction, and applying an external force in the horizontal direction to the moving unit; And an OIS camera module. The method according to claim 1,
A suction unit for generating a magnetic force and connecting the moving unit to the fixing unit in the direction of the optical axis is provided,
And a pressing member for elastically pressing the moving unit in the horizontal direction with respect to the fixing unit.
The method according to claim 1,
A driving magnet for generating the moving force in the optical axis direction of the lens bobbin portion is provided in the moving unit,
A suction magnet is disposed in the fixing unit,
The suction magnet pulls the moving unit so that the optical center of the moving unit is aligned with the optical axis so that the horizontal magnetic force center point of the driving magnet and the horizontal magnetic force center point of the suction magnet coincide with each other, OIS camera module to approach the initial position in the horizontal direction.

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