Patent ID: 12216330

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to the description, terms or words used in the present specification and claims should not be construed as being limited to their usual or dictionary meanings, and the terms or words should be interpreted as meanings and concepts consistent with a technical idea of the present invention based on a principle that the inventor can properly define concepts of the terms in order to describe his or her invention in the best way.

Accordingly, the embodiments described in the present specification and configurations illustrated in the drawings are only the most exemplary embodiments of the present invention and do not represent all technical ideas of the present invention, and thus, it should be understood that at the time of the present application, there may be various equivalents and modifications that can replace the embodiments and configurations.

FIG.1is a perspective view of an overall assembly of an actuator for driving a reflector according to one embodiment of the present invention.

As illustrated inFIG.1, an actuator100for driving a reflector according to one embodiment of the present invention may of course be implemented as a single device and may be implemented in the form of a camera module including a lens assembly, a lens driving module that implements autofocus of the lens assembly, an image sensor, and the like. Here, when the actuator100for driving a reflector is implemented in the form of a camera module, the lens assembly may be located below the actuator100for driving a reflector.

According to the present invention, light of a subject is not directly introduced into the lens assembly and is introduced into the lens assembly after a path of light is changed (refracted, reflected, or the like) through a reflector110provided in the actuator100for driving a reflector of the present invention.

As described above, the actuator100for driving a reflector according to one embodiment of the present invention is configured so that the light is introduced into the lens assembly after the path of light is refracted by the reflector110. Accordingly, since the lens assembly itself does not need to be installed in a thickness direction of a mobile terminal, even when a lens having long physical characteristics in a direction of an optical axis such as a zoom lens is mounted on the mobile terminal, a thickness of the mobile terminal does not increase, and thus it is possible to reduce a size of the mobile terminal.

As illustrated inFIG.1, a path of light coming from the outside is a path Z1, and a path through which the light introduced from the outside is refracted or reflected by the reflector110and introduced into the lens assembly is a path Z. In the following description, a Z-axis direction, which is a direction in which light is introduced into the lens assembly, is referred to as an optical axis to a direction of the optical axis.

The reflector110may be one selected from or a combination of a mirror and a prism and, may further be implemented as one of various members capable of changing light introduced from the outside in the direction of the optical axis.

The lens assembly may be a zoom lens in which not only a single lens but also a plurality of lenses or lens groups, or an optical member such as a prism or a mirror may be included therein, and when the lens assembly is constituted by a zoom lens or a zoom lens barrel, the lens assembly may have a shape extending in the direction of the optical axis.

An image sensor such as a CCD or CMOS that converts a light signal into an electric signal may be provided below the lens assembly based on the direction of the optical axis, and a filter for blocking or transmitting a light signal of a specific band may also be provided.

As will be described in detail below, when shaking occurs due to hand shaking or the like based on a first direction (Y-axis direction, vertical direction) and a second direction (X-axis direction, horizontal direction) perpendicular to the optical axis, the actuator100for driving a reflector of the present invention may implement Optical Image Stabilization (OIS) in the first direction and the second direction by rotationally moving the reflector110in a direction that compensates for the movement.

FIGS.2and3are exploded perspective views of an entirety of the actuator for driving a reflector according to one embodiment of the present invention.

As illustrated inFIGS.2and3, the actuator100for driving a reflector according to the embodiment of the present invention may include the reflector110, a movement frame120, a first support frame130, a second support frame140, a circuit board150, and a case165.

Here, the reflector110is installed in the movement frame120, and the first support frame130is accommodated in the second support frame140. In addition, the movement frame120in which the reflector110is installed is seated on the first support frame130and accommodated in the second support frame140.

In addition, the circuit board150is coupled to an outer surface of the second support frame140, and the case165fixes the movement frame120, the second support frame140, and the circuit board150and functions as a shield can.

As will be described in detail below, the actuator100for driving a reflector according to the embodiment of the present invention includes a first rotation guide191and a second rotation guide192having a ball160therein.

Specifically, the first rotation guide191is provided between the movement frame120and the first support frame130and has an arc shape so that the movement frame120is rotated in the first direction (Y-axis direction, vertical direction). Moreover, the second rotation guide192is provided between the first support frame130and the second support frame140and has an arc shape so that the first support frame130rotates in the second direction (X-axis direction, horizontal direction). Here, at least one of centers of curvature of the first rotation guide191and the second rotation guide192coincides with a center of rotation of the reflector110.

In this way, it is preferable that the centers of curvature of the first rotation guide191and the second rotation guide192coincide with the center of rotation of the reflector110. However, the present invention is not limited thereto, and even when the centers are partially shifted due to manufacturing tolerances or the like, this falls within a scope of the present invention.

FIGS.4and5are exploded perspective views of components coupled to a movement frame according to a first embodiment of the present invention, andFIG.6is an exploded perspective view of components coupled to a movement frame according to a second embodiment of the present invention.

As illustrated inFIGS.4and5, the movement frame120may be provided with the reflector110, a first magnet122, and a first yoke125.

The movement frame120provides a seating surface on which the reflector110is installed, a first installation groove121is formed on an outer surface perpendicular to the direction of the optical axis, and a second installation groove124and a first guide rail123ahaving an arc shape are formed on an outer surface parallel to the direction of the optical axis. Here, the first guide rails123amay be provided as the pair of first guide rails123afacing each other based on the center of curvature of the first rotation guide191.

The first magnet122is installed in the first installation groove121, and the first yoke125is installed in the second installation groove124. In addition, a plurality of balls160are located in the first guide rail123a. Here, a center of the first yoke125coincides with the center of curvature of the first rotation guide191.

Meanwhile, as illustrated inFIG.6, a plurality of first holders123bmay be provided instead of the first guide rail123a. Here, the first holder123bmay be formed in plural and be disposed along an arc shape, and the ball160is located inside each first holder123b.

FIGS.7and8are exploded perspective views of components coupled to the first support frame according to the first embodiment of the present invention, andFIGS.9and10are exploded perspective views of components coupled to the first support frame according to the second embodiment of the present invention.

As illustrated inFIGS.7and8, the first support frame130provides a movement space of the movement frame120and may include a second magnet135and a third magnet136.

The first support frame130may include a first plate130aparallel to the direction of the optical axis and a second plate130bperpendicular to the direction of the optical axis.

The first support frame130includes a third installation groove132formed inside the first plate130a, that is, in an inner surface of the first support frame130parallel to the direction of the optical axis, and a second guide rail133ahaving an arc shape corresponding to the first guide rail123aof the movement frame120. Here, the second guide rail133amay be provided as the pair of second guide rails133afacing each other based on the center of curvature of the first rotation guide191.

When the movement frame120and the first support frame130are coupled to each other, the first guide rail123aand the second guide rail133aform the first rotation guide191, or the first holder123band the second guide rail133aform the first rotation guide191.

In addition, the first support frame130includes a fourth installation groove134and a third guide rail137ahaving an arc shape that are formed outside the second plate130b, that is, on an outer surface of the first support frame130perpendicular to the direction of the optical axis. Here, the third guide rail137amay be provided as the pair of third guide rails137afacing each other based on the center of curvature of the second rotation guide192.

The second magnet135is installed in the fourth installation groove134, and the third magnet136is installed in the third installation groove132. In addition, a plurality of balls160are located in the second guide rail133aand the third guide rail137a. Here, the center of the second magnet135coincides with the center of curvature of the second rotation guide192.

Meanwhile, as illustrated inFIGS.9and10, a plurality of second holders133bmay be provided instead of the second guide rail133a. In this case, when the movement frame120and the first support frame130are coupled to each other, the first guide rail123aand the second holder133bform a first rotation guide191. In addition, a plurality of third holders137bmay be provided instead of the third guide rail137a.

Here, each of the second holder133band the third holder137bmay be formed in plural and disposed along an arc shape, and the ball160is located inside each holder.

FIGS.11and12are exploded perspective views of components coupled to the second support frame according to the first embodiment of the present invention, andFIGS.13and14are exploded perspective views of components coupled to the second support frame according to the second embodiment of the present invention.

As illustrated inFIGS.11and12, the second support frame140is formed in a box shape, provides a movement space of the first support frame130, and has an opening formed in the Y-axis direction which is a light traveling path and the direction of the optical axis. In addition, a first installation hole141is formed corresponding to the first magnet122of the movement frame120, and a second installation hole142is formed corresponding to the second magnet135of the first support frame130. In addition, a fourth guide rail147ais formed corresponding to the third guide rail137aof the first support frame130. Here, the fourth guide rail147amay be formed as the pair of fourth guide rails147afacing each other based on the center of curvature of the second rotation guide192.

When the first support frame130and the second support frame140are coupled, the third guide rail137aand the fourth guide rail147aform the second rotation guide192, or the third holder137band the fourth guide rail147aform the second rotation guide192.

Meanwhile, as illustrated inFIGS.13and14, a plurality of fourth holders147bmay be provided instead of the fourth guide rail147a. In this case, when the first support frame130and the second support frame140are coupled, the third guide rail137aand the fourth holder147bform the second rotation guide192.

Here, the fourth holder147bmay be formed in plural and disposed along an arc shape, and the ball160is located inside each fourth holder147b.

FIG.15is a perspective view of an overall assembly of a circuit board according to one embodiment of the present invention, andFIGS.16A and16Billustrate plan views of the circuit board according to one embodiment of the present invention.

As illustrated inFIGS.15and16A-16B, the circuit board150may include a first drive coil151, a second drive coil154, and first to fourth Hall sensors152,153,155, and156.

The circuit board150may include a first circuit board150aand a second circuit board150bthat is bent to be perpendicular to the first circuit board150a. Here, the second drive coil154and third and fourth Hall sensors155and156are provided in the first circuit board150a, and the first drive coil151and first and second Hall sensors152and153are provided in the second circuit board150b.

The circuit board150is coupled to the second support frame140so that the first drive coil151is installed in the first installation hole141of the second support frame140, and the second drive coil154is installed in the second installation hole142of the second support frame140.

Accordingly, the first drive coil151and the first magnet122of the movement frame120face each other, and the second drive coil154and the second magnet135of the first support frame130face each other.

The first drive coil151generates an electromagnetic force in the first magnet122provided in the movement frame120to rotationally move the movement frame120in a first direction (Y-axis direction, vertical direction) based on the first support frame130.

The first magnet122receives a driving force due to the electromagnetic force from the first drive coil151, and the movement frame120in which the first magnet122is installed is rotationally moved by this driving force based on the first support frame130.

In this respect, the first support frame130providing a movement space of the movement frame120corresponds to a fixed body from a relative viewpoint based on the movement frame120.

In this way, when the movement frame120, in which the reflector110is installed, is rotationally moved (YZ plane) based on the first support frame130, the reflector110physically moves together with the movement frame120and is rotationally moved, and a position where the light of the subject is introduced into an image sensor (not illustrated) is shifted by the rotational movement of the reflector110. Accordingly, the OIS for the first direction is implemented.

Preferably, the first magnet122is installed at a center of the movement frame120so that the rotational movement of the movement frame120is stably supported and driving precision is improved, and a center of the first magnet122coincides with a center of rotation of the reflector110in the first direction. However, the present invention is not limited thereto, and even when the centers are partially shifted due to manufacturing tolerances or the like, this falls within the scope of the present invention.

The ball160is located in the first rotation guide191between the movement frame120and the first support frame130, and the movement frame120rotationally moves in a state of being in contact with the ball160.

The first yoke125provided in the movement frame120is made of a magnetic material such as metal and performs a function of generating an attractive force in the third magnet136provided in the first support frame130.

The first support frame130, in which the third magnet136is installed, is pulled in a direction in which the first yoke125is provided, that is, in a direction of the first support frame130by the attractive force generated as described above. Accordingly, the movement frame120and the ball160are pressed against each other, and the ball160and the first support frame130are pressed against each other.

In addition, the first yoke125may also perform a function of returning the movement frame120to an original reference position when power being supplied to the first drive coil151is stopped. In order to improve efficiency of a functional control for the rotational movement of the movement frame120as well as returning to the reference position, preferably, a center of the first yoke125coincides with a center of the third magnet136, and a shape of the first yoke125is the same as that of the third magnet136.

The first and second Hall sensors152and153use a Hall effect to detect a position (specifically, a position of the reflector110installed in the movement frame120in which the first magnet122is provided) of the first magnet122.

The first and second Hall sensors152and153may be implemented in the form of a single chip together with a driving driver that controls a magnitude and direction of power applied to the first drive coil151using output values of the first and second Hall sensors152and153for feedback control.

Meanwhile, the present invention includes two first and second Hall sensors152and153to compensate for crosstalk, and when the first and second Hall sensors152and153are disposed at the inner edge of the first drive coil151, a compensation amount of the crosstalk increases as the position of the first magnet122changes. In order to solve the problem, it is preferable that the first and second Hall sensors152and153are disposed at an inner center of the first drive coil151.

When the first rotation guide191includes the first holder123bor the second holder133b, the movement frame120is rotationally moved by the ball160constrained by the first holder123bor the second holder133brotationally moving along the first guide rail123aor the second guide rail133a.

Specifically, the ball160may perform a rolling or rotating movement in a state of being accommodated in the first holder123bor the second holder133b, and a distance between the balls160is kept constant. Therefore, it is possible to essentially solve problems of devices of the related art such as support instability caused by free movement of the ball, tilt of the moving body, degradation of the driving precision, or the like.

Furthermore, in the case of the present invention, since the balls160may be spaced apart from each other by an appropriate distance, an additional space can be secured, and a ball having a relatively larger size can be applied.

In addition, preferably, the inner surface of the first holder123bor the second holder133bbecomes narrower inward so that a point contact with the ball160and physical support by the ball160are more effectively implemented.

The second drive coil154generates an electromagnetic force in the second magnet135provided in the first support frame130to rotationally move the first support frame130in the second direction (X-axis direction, horizontal direction) based on the second support frame140.

The second magnet135receives a driving force by the electromagnetic force from the second drive coil154, and the first support frame130in which the second magnet135is installed is rotationally moved based on the second support frame140by this driving force.

In this respect, the second support frame140providing a movement space of the first support frame130corresponds to a fixed body from a relative viewpoint based on the first support frame130.

In this way, when the first support frame130, in which the movement frame120is installed, is rotationally moved (XZ plane) based on the second support frame140, the reflector110physically moves together with the first support frame130and is rotationally moved, and a position where the light of the subject is introduced into an image sensor (not illustrated) is shifted by the rotational movement of the reflector110. Accordingly, the OIS for the second direction is implemented.

Preferably, the second magnet135is installed at a center of the first support frame130so that the rotational movement of the first support frame130is stably supported and driving precision is improved, and a center of the second magnet135coincides with a center of rotation of the reflector110in the second direction. However, the present invention is not limited thereto, and even when the centers are partially shifted due to manufacturing tolerances or the like, this falls within the scope of the present invention.

The ball160is located in the second rotation guide192between the first support frame130and the second support frame140, and the first support frame130rotationally moves in a state of being in contact with the ball160.

Although not illustrated in the drawings, a second yoke may be provided below the circuit board150. Here, the second yoke is disposed at a position corresponding to the second magnet135.

The second yoke is made of a magnetic material such as metal and performs a function of generating an attractive force in the second magnet135provided in the first support frame130.

The first support frame130, in which the second magnet135is installed, is pulled in a direction in which the second yoke is provided, that is, in a direction of the second support frame140by the attractive force generated as described above. Accordingly, the first support frame130and the ball160are pressed against each other, and the ball160and the second support frame140are pressed against each other.

In addition, the second yoke may also perform a function of returning the first support frame130to an original reference position when the power being supplied to the first drive coil151is stopped. In order to improve efficiency of a functional control for the rotational movement of the first support frame130as well as returning to the reference position, preferably, a center of the second yoke coincides with a center of the second magnet135, and a shape of the second yoke is the same as that of the second magnet135.

The third and fourth Hall sensors155and156use a Hall effect to detect a position (specifically, the position of the reflector110installed in the first support frame130in which the second magnet135is provided) of the second magnet135.

The third and fourth Hall sensors155and156may be implemented in the form of a single chip together with a driving driver that controls a magnitude and direction of power applied to the second drive coil154using output values of the third and fourth Hall sensors155and156for feedback control.

The second drive coil154includes a first sub-drive coil154athat rotationally moves the first support frame130in a first rotation direction (for example, clockwise direction) and a second sub-drive coil154bthat rotationally moves the first support frame130in a second rotation direction (for example, counterclockwise direction) opposite to the first rotation direction.

Here, in order to increase the output values of the third and fourth Hall sensors155and156, preferably, the third and fourth Hall sensors155and156are respectively disposed at inner edges of the first sub-drive coil154aand the second sub-drive coil154band each disposed at the edge farthest from the center of curvature of the second rotation guide192.

When the second rotation guide192includes the third holder137bor the fourth holder147b, the first support frame130is rotationally moved by the ball160constrained by the third holder137bor the fourth holder147brotationally moving along the third guide rail137aor the second guide rail147a.

Specifically, the ball160may perform a rolling or rotating movement in a state of being accommodated in the third holder137bor the fourth holder147b, and a distance between the balls160is kept constant. Therefore, it is possible to essentially solve problems of devices of the related art such as support instability caused by the free movement of the ball, the tilt of the moving body, the degradation of the driving precision, or the like.

Furthermore, in the case of the present invention, since the balls160may be spaced apart from each other by an appropriate distance, an additional space can be secured, and a ball having a relatively larger size can be applied.

In addition, preferably, the inner surface of the third holder137bor the fourth holder147bbecomes narrower inward so that the point contact with the ball160and the physical support by the ball160are more effectively implemented.

FIG.17is a view for describing structural features of the first rotation guide191of the actuator for driving a reflector according to one embodiment of the present invention.

Referring toFIG.17, in the actuator100for driving a reflector according to one embodiment of the present invention, a center of curvature CC1of the first rotation guide191(for example, the first guide rail123a) coincides with a center of rotation Cr1of the reflector110in the first direction.

Meanwhile, when the center of curvature CC1of the first rotation guide191and the center of rotation Cr1of the reflector110in the first direction do not coincide with each other, even when the same driving force is applied to the first magnet122, an amount of rotation of the movement frame120differs depending on the position of the movement frame120, and there is a problem in that a separate compensation algorithm should be applied to compensate for the different amount of rotation for each position.

However, in the actuator100for driving a reflector according to the embodiment of the present invention, the center of curvature CC1of the first rotation guide191coincides with the center of rotation Cr1of the reflector110. Accordingly, regardless of the position of the movement frame120for the same driving force, since the amount of rotation of the movement frame120is the same, the separate compensation algorithm is not required.

FIGS.18A and18Billustrate views for describing a driving method using the first rotation guide191of the actuator for driving a reflector according to one embodiment of the present invention.

First, as illustrated inFIG.18A, when the first drive coil151generates an electromagnetic force in the first magnet122so that the movement frame120rotationally moves in the first rotation direction (for example, counterclockwise direction), the reflector110also rotationally moves together.

Next, as illustrated inFIG.18B, when the power being supplied to the first drive coil151is stopped, the movement frame120is returned to the original reference position by the attraction forces of the first yoke125and the third magnet136.

FIG.19is a view for describing structural features of the second rotation guide192of the actuator for driving a reflector according to one embodiment of the present invention.

Referring toFIG.19, in the actuator100for driving a reflector according to one embodiment of the present invention, a center of curvature CC2of the second rotation guide192(for example, the third guide rail137a) coincides with a center of rotation Cr2of the reflector110in the second direction.

Meanwhile, when the center of curvature CC2of the second rotation guide192and the center of rotation Cr2of the reflector110in the second direction do not coincide with each other, even when the same driving force is applied to the second magnet135, an amount of rotation of the first support frame130differs depending on the position of the first support frame130, and there is a problem in that a separate compensation algorithm should be applied to compensate for the different amount of rotation for each position.

However, in the actuator100for driving a reflector according to the embodiment of the present invention, the center of curvature CC2of the second rotation guide192coincides with the center of rotation Cr2of the reflector110in the second direction. Accordingly, regardless of the position of the first support frame130for the same driving force, since the amount of rotation of the first support frame130is the same, the separate compensation algorithm is not required.

FIGS.20A and20Billustrate views for describing a driving method using the second rotation guide192of the actuator for driving a reflector according to one embodiment of the present invention.

First, as illustrated inFIG.20A, when the second drive coil154generates an electromagnetic force in the second magnet135so that the first support frame130rotationally moves in the first rotation direction (for example, counterclockwise direction), the movement frame120and the reflector110also rotationally moves together.

Next, as illustrated inFIG.20B, when the power being supplied to the second drive coil154is stopped, the first support frame130is returned to the original reference position by the attraction forces of the second yoke and the second magnet135.

According to the present invention, the center of curvature of the rotation guide coincides with the center of rotation of the reflector. Accordingly, for the same driving force, the amount of rotation of the moving body can be the same regardless of the position of the moving body.

In addition, according to the present invention, the position of the ball disposed between the moving body and the fixed body to guide the rotational movement of the moving body is specified at an exact position regardless of the OIS drive. Accordingly, physical support according to the rotational movement of the moving body is made to be more balanced, and thus a phenomenon that the moving body is tilted can be fundamentally prevented.

In addition, according to the present invention, the plurality of balls are disposed, but a pitch between the balls can be designed to be optimized for the rotational movement of the moving body, and thus more stable physical support and the precision of the OIS can be further improved due to the stable physical support.

In addition, according to the present invention, the ball having a relatively large size can be disposed in the actuator having the same size, and thus behavior of the ball can be improved. Moreover, it is possible to further suppress adverse physical influences generated between the ball and the guide rail to improve driving performance and further increase durability.

Heretofore, the present invention is described by the limited embodiments and drawings. However, the present invention is not limited thereto, and it goes without saying that various modifications and variations are possible within an equivalent range of a technical idea of the present invention and claims described below by those of ordinary skill in a technical field to which the present invention belongs.

In the above description of the present invention, modifiers such as first and second are only terms of instrumental concepts used to relatively distinguish components between each other, and thus the modifiers should not be interpreted as terms used to indicate a specific order, priority, or the like.

The accompanying drawings for descriptions of the present invention and the embodiments thereof may be illustrated in a somewhat exaggerated form in order to emphasize or highlight a technical content according to the present invention. However, it is obvious that various types of modifications can be applied at a level of a person skilled in the art in consideration of the above-described contents and items illustrated in the drawings.