Actuator for camera

Abstract

The present disclosure relates to an actuator for a camera, the actuator comprising: a lens module, the lens module emitting light toward an image sensor; a housing, the housing surrounding the lens module; and a patterned member, the patterned member being disposed on an inner surface of the housing, wherein the inner surface is an inner surface between the lens module and the image sensor. The patterned member comprises protrusions, the protrusions being repeatedly arranged along an optical axis, wherein each protrusion longitudinally extends in a direction perpendicular to the optical axis.

Description

Technical Field

[0001] The present disclosure relates to an actuator for a camera and a camera module including the same. More particularly, the present disclosure relates to an actuator for a camera capable of reducing flare, for example, from internal reflection. Background Art

[0002] With the development of hardware technology for image processing and the increase in user demand for image capture, functions such as auto focus (AF) and optical image stabilization (OIS) have been applied to camera modules installed in portable terminals such as cellular phones and smart phones, as well as independent camera devices.

[0003] An auto focus (AF) function (or auto focus function) refers to a function of bringing a subject into focus by linearly moving a carrier having a lens in an optical axis direction to generate a clear image at an image sensor (CMOS, CCD, etc.) located at the rear of the lens.

[0004] In addition, an optical image stabilization (OIS) function refers to a function of improving image clarity by adaptively moving a bracket having a lens in a direction to compensate for the shake when the lens shakes due to vibration.

[0005] Current mobile terminals are equipped with zoom lenses, the specifications of which support functions such as variable focal length adjustment and shooting of long-distance images, to meet growing consumer demands and further facilitate users.

[0006] Since zoom lenses themselves have a structure of a plurality of lenses or lens assemblies in a parallel array, or are distinguished by having an extended size along an optical axis, they require a larger space in a mobile terminal accommodating them.

[0007] In an effort to make a zoom lens having such physical characteristics seamlessly coordinate with the shape of a mobile terminal, an actuator and a camera module including a zoom lens having a physical structure in which light from an object is refracted with the help of a reflectometer placed in front of the lens have recently been developed.

[0008] Light from an object passing through the lens may adopt an optical path that may have a wide distribution of incident angles. An increase in the distance between the lens and the image sensor, such as an increase in the back focal length (the distance between the image sensor and the physical end of the optical system), may result in a phenomenon known as light speckling, where light saturation appears in certain portions of the image because some of the light leaving the lens may reflect off of internal surfaces such as the housing and enter the image sensor.

[0009] The spot problem becomes worse for actuators equipped with reflectometers as the distance from the reflectometer to the image sensor becomes even longer.

[0010] In order to solve this problem, it is known in the art to install a reflection inhibitor made of a material with poor light absorption or reflection on a housing or a casing (shielding cover).

[0011] However, these embodiments not only result in reduced process efficiency due to the additional step of mounting the reflection inhibitor to the actuator, but also, particularly since the reflection inhibitor is formed of materials such as films, paints, and non-woven fabrics, foreign matter (such as broken particles and debris) is generated from the inhibitor material and dispersed in the air.

[0012] Such generated foreign matter may limit the driving accuracy of the actuator and may likely continue to cause another level of image degradation, such as dead pixels, because the foreign matter may adhere to the surfaces of the lens and image sensor or block the optical path. Summary of the invention

[0013] Technical issues

[0014] The present invention has been conceived to solve the above-mentioned problems in the above-mentioned context. A technical object of the present invention is to provide an actuator for a camera which can effectively reduce light spots by means of a physical structure that is easily realized on the inner surface of a housing.

[0015] These and other objects and advantages of the present disclosure can be understood from the following detailed description and will become more apparent from the exemplary embodiments of the present disclosure. In addition, it will be easily understood that the objects and advantages of the present disclosure can be achieved by the means shown in the appended claims and their combinations.

[0016] Technical Solution

[0017] In order to achieve the above technical purpose, in one aspect of the present invention, there is provided an actuator for a camera, the actuator comprising: a lens module from which light is emitted toward an image sensor; a housing, the housing surrounding the lens module; and a patterned member, the patterned member being arranged on an inner surface of the housing, the inner surface being an inner surface between the lens module and the image sensor. The patterned member of the present invention is configured to include protrusions repeatedly arranged along an optical axis, wherein each protrusion extends longitudinally in a direction perpendicular to the optical axis.

[0018] Preferably, the protrusion of the present invention has a triangular cross section. Specifically, the protrusion of the present invention includes a vertical surface perpendicular to the inner surface of the housing and includes an inclined surface, the surface of the inclined surface is directed toward the image sensor.

[0019] According to a specific embodiment, the present invention further includes a reflectometer module, which is disposed in front of the lens module and reflects light from an object toward the lens module.

[0020] Furthermore, the patterned member of the present invention may have its exposed surface subjected to a roughened surface treatment. Preferably, the patterned member is formed integrally with the housing.

[0021] Beneficial effects

[0022] According to the preferred embodiments of the present disclosure, light spots caused by processes such as internal reflection can be effectively reduced through uncomplicated structural improvements.

[0023] Since the present invention can be implemented by processing or molding the inner surface of the housing as an integral part of the actuator, the present invention can be easily applied to the general manufacturing process of the actuator components. The efficiency of the manufacturing process itself can be improved because it saves additional steps for realizing dedicated components as in the prior art.

[0024] Furthermore, according to the present invention, since the generation of foreign matter is prevented from the beginning by forgoing the addition of a component formed of a foreign material, the accuracy of actuator driving can be consistently maintained. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, are used to provide a further understanding of the technical features of the present disclosure. Therefore, the present disclosure is not interpreted as being limited to the accompanying drawings.

[0026] Figures 1 to 3 shows the overall structure of a camera actuator and a camera module according to a preferred embodiment of the present invention;

[0027] Figure 4 The structure of the reflectometer module according to the preferred embodiment of the present invention is shown in detail;

[0028] Figure 5 The structure of the actuator for a camera according to the present invention is shown in detail;

[0029] Figure 6 A housing equipped with a patterned member according to a preferred embodiment of the present invention is shown;

[0030] Figure 7 A patterned member according to a preferred embodiment of the present invention is shown;

[0031] Figure 8 Shown in detail Figure 7 The patterned component depicted in ;

[0032] Fig. 9 and Fig.10 An actuator for a camera and a camera module according to another embodiment of the present invention are shown;

[0033] Fig.11 The path of light reflected from a protrusion according to the present invention is shown.

[0034] Reference numerals

[0035] 1000: Camera module

[0036] 100: Actuator 110: Housing

[0037] 111: Orifice 115: Patterned component

[0038] 1151: protrusion 1151A: vertical surface

[0039] 1151B: inclined surface 120 (130): bracket

[0040] 170: Circuit board 180: Yoke plate

[0041] 190: Shell 191: Opening

[0042] 1111, 1112, 222, 232: Guide rails

[0043] 30: Image sensor 50: Fixed lens

[0044] 60, 70, R: Lens

[0045] B1: First sphere B2: Second sphere

[0046] B3: Third sphere C1: First coil

[0047] C2: Second coil C3: Third coil

[0048] M1: first magnet M2: second magnet

[0049] M3: Third magnet D: Operation driver

[0050] 200: reflectometer module 210: reflectometer

[0051] 220: Rotating bracket 230: Intermediate guide DETAILED DESCRIPTION

[0052] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to the general meaning and dictionary meaning, but should be interpreted based on the meaning and concept corresponding to the technical aspects of the present disclosure according to the principle of allowing the inventor to appropriately define the terms for the best interpretation.

[0053] Therefore, the descriptions presented herein are merely preferred examples for illustrative purposes, and are not intended to limit the scope of the present disclosure, and it should be appreciated that other equivalents and modifications may be made thereto without departing from the scope of the present disclosure.

[0054] Figures 1 to 3 The overall configuration of an actuator for a camera (hereinafter referred to as “actuator”) 100 and a camera module 1000 according to a preferred embodiment of the present invention is depicted. Figure 4 The configuration of the reflectometer module 200 according to the preferred embodiment of the present invention is shown in detail.

[0055] The actuator 100 of the present invention can be used with Figure 1 The reflectometer module 200 and other components are shown to be implemented together as a part of the camera module 1000, or needless to say, implemented as a single independent device.

[0056] The actuator 100 of the present invention is used to perform automatic focusing or zooming by driving a single bracket or each of a plurality of brackets to which a lens module (lens assembly) R is attached in linear motion along an optical axis.

[0057] The reflectometer module 200 may be disposed in front of the actuator 100 of the present invention (along the optical axis), and after light from an object enters through, for example, an opening 191 formed on a housing 190 that is particularly used as a shield, the reflectometer module 200 reflects or refracts an optical path Z1 of the light from the object in a direction toward the lens module R. The light thus reflected or refracted toward the optical axis passes through the lens module R and enters the image sensor 30, such as a complementary metal oxide semiconductor (CMOS) and a charge coupled device (CCD).

[0058] The reflectometer module 200 for modifying the optical path may include a reflectometer 210, which may include one selected from a mirror, a prism, or a combination thereof. The reflectometer 210 may be composed of various materials capable of changing the path of light incident from the outside toward the optical axis, but glass is a preferred medium for high-performance optical properties.

[0059] The camera module 1000 of the present invention including elements such as the reflectometer module 200 is configured to refract the path of light toward the lens. This allows the entire device to be disposed longitudinally of the mobile terminal rather than across its width, thereby helping to keep the mobile terminal small and thin.

[0060] In some embodiments, the reflectometer 210 is configured to perform a rotational motion by the action of a driving device (such as a magnet and a coil) capable of generating a magnetic field. Therefore, when the reflectometer 210 moves or performs a rotational motion, light from an object reflected (refracted) by the reflectometer 210 is guided along the ±Y axis and / or the ±X axis to enter the lens and the image sensor 30, so that the camera shake along the X axis and / or the Y axis can be corrected.

[0061] Specifically, the reflectometer module 200 may be configured to include a rotating bracket 220 equipped with a reflectometer 210 and an intermediate guide 230 .

[0062] The rotating bracket 220 is configured to rotate once the third coil C3 (see FIG. Figure 5 ) and the third magnet M3 mounted on the rotating bracket 220 generate an electromagnetic force, and the rotating bracket 220 performs a rotational motion with the intermediate guide 230 as a reference. The accompanying drawings show an embodiment in this regard, in which the rotating bracket 220 performs a rotational motion in the YZ plane with the intermediate guide 230 as a fixed reference.

[0063] Therefore, when the rotating bracket 220 performs a rotational motion around the X axis in the YZ plane (RA, see Figure 4 ), so does the reflectometer 210 which accompanies it in the same physical movement in the same direction.

[0064] Therefore, when the reflectometer 210 having an inclined surface from which light from an object is reflected performs rotational motion in the YZ plane as described above, incident light toward the image sensor 30 shifts its path in the Y-axis direction, thereby correcting the Y-axis component of camera shake.

[0065] In certain embodiments, a guide rail 222 for accommodating or guiding the third ball B3 may be formed on at least one of the surfaces of the intermediate guide 230 and the rotating bracket 220 that face the other.

[0066] At the same time, when the second coil C2 (see Figure 5 ) provides a driving force to the second magnet M2 equipped to the lower portion (based on the X-axis) of the intermediate guide 230, the intermediate guide 230 performs a rotational motion in the XZ plane along with the rotating bracket 220 attached thereto.

[0067] Therefore, when the intermediate guide 230 performs rotational motion in the XZ plane, so does the reflectometer 210, and incident light toward the image sensor 30 shifts its path in the X-axis direction, thereby correcting the X-axis component of the camera shake.

[0068] As shown in the figure, there is a second sphere B2 (see Figure 6A guide rail 232 having a circular shape as a portion of the intermediate guide 230 may be formed on a rear surface of the intermediate guide 230 to guide the intermediate guide 230 (in the XZ plane) to perform rotational movement.

[0069] The light from the object thus reflected by the reflectometer module 200 enters the lens module R equipped in the actuator 100, and the position along the optical axis of the lens module R is adjusted by the actuator 100 of the present invention to perform functions such as zooming and auto-focusing.

[0070] The image sensor 30 may be constructed inside the actuator 100 of the present invention, or more specifically, inside the housing 110, because the image sensor 30 may be designed to be coupled to a mainboard of an application (e.g., a smartphone) on which the actuator 100 of the present invention is mounted. Needless to say, the image sensor 30 may alternatively be placed outside the actuator 100 and at a position corresponding to the aperture 111 formed on the housing 110, as shown in the figure.

[0071] In addition, if Fig. 9 and Fig.10 As shown, there may be a plurality of brackets 120, 130 that move along the optical axis, wherein each bracket is mounted with a lens (lens assembly) 60, 70. In such an embodiment, a fixed lens 50 may be disposed in front of the actuator 100 (e.g. Fig.10 ), to enhance optical performance such as the zoom ratio of actuator 100.

[0072] The reflectometer module 200 equipped with the reflectometer 210 can be implemented as follows Fig. 9 and Fig.10 Separate module shown. Additionally, in certain embodiments, a yoke plate 180 may be attached to the actuator 100 of the present invention so that the magnetic force is not dissipated and concentrated on the magnets.

[0073] It should be clear to those skilled in the art that the axes depicted in the drawings herein, references to these axes, and terms used herein to define directions relative to a particular axis in question (such as up, down, front, back, and vertical) are used only to provide relative standards when describing embodiments of the present invention, and are not intended to define a particular direction or position in absolute terms. It is apparent that such directions or positions may vary depending on factors such as the position of the object in question, the position of the viewer, and the direction of the view.

[0074] For the purpose of describing the embodiments of the present invention, hereinafter, the optical axis (Z axis), i.e., the axis corresponding to the path of incident light toward the lens module R, etc., will be a reference point for defining the front and rear as described above. Similarly, the Y axis will be a reference point for defining the left and right sides, and the X axis will be a reference point for the upper, lower, or vertical directions.

[0075] Figure 5 The configuration of the actuator 100 of the present invention is shown in detail. Figure 6 A housing 110 equipped with a patterning member 115 according to a preferred embodiment of the present invention is shown.

[0076] like Figure 5 As depicted, the actuator 100 of the present invention includes a housing 110, which corresponds to a basic frame of the actuator 100 and contains internal components, and a lens module R that emits light toward the image sensor 30. In some embodiments, the actuator 100 may include a bracket 120 to which the lens module R is mounted.

[0077] The bracket 120 on which the lens module R is mounted corresponds to a moving body that moves linearly along the optical axis (Z axis), and correspondingly, the housing 110 corresponds to a fixed body.

[0078] The bracket 120 is provided with a first magnet M1 , and a first coil C1 is provided in the housing 110 , the first coil C1 facing the first magnet M1 and applying a driving force to the first magnet M1 .

[0079] Once the operating driver D applies power of appropriate magnitude and direction to the first coil C1 , an electromagnetic force is generated between the first coil C1 and the first magnet M1 , and the generated force moves the bracket 120 back and forth along the optical axis.

[0080] Although the drawings show a single bracket 120 for mounting the lens module R, this is only one of possible examples. Fig. 9 and Fig.10 The particular embodiment shown may include a plurality of lenses 60 , 70 and brackets 120 , 130 .

[0081] Therefore, when each bracket 120 moves linearly along the optical axis (along the Z axis), the lens module R mounted on the bracket 120 also moves linearly along the optical axis, thereby achieving zooming or auto-focusing.

[0082] The first ball B1 is preferably placed between the bracket 120 and the housing 110 so that the bracket 120 can perform smooth linear motion with minimal friction.

[0083] In order to achieve effective guidance toward linearity in the path, it is preferred that the guide rail 1111 is configured to accommodate a portion of the first sphere B1 extending along the optical axis and formed on one or more of the bracket 120 and the housing 110 . Figure 6 The guide rail 1112 shown in FIG. Figure 4The guide rail 232 of the intermediate guide 230 is depicted. The guide rail 1112 guides the rotation (XZ plane) of the reflectometer module 200 regulated by the second sphere B2 and the like.

[0084] As shown in the drawings, in the present invention, a patterned member 115 is formed on the inner surface of the housing 110. The patterned member 115 is used to prevent light spots, that is, to block unnecessary light from entering the image sensor 30 by dispersing or scattering the components of light that passes through the lens module R and reflects off from the inner surface of the housing 110.

[0085] Therefore, the patterned member 115 of the present invention is an element whose function is to weaken and attenuate the component of light entering the image sensor 30, which has passed through the lens module R and has been reflected from the housing 110 thereafter. Therefore, it is preferred that the patterned member 115 is located behind the lens module R (along the Z axis) as shown in the figure, and is located on the path of the light traveling toward the image sensor 30 after passing through the lens module R, that is, on one of the inner surfaces of the housing 110 between the lens module R and the image sensor 30.

[0086] Although the patterned member 115 of the present invention is preferably disposed on the bottom surface of the housing 110 so that it is placed corresponding to the inclined surface of the reflectometer 210, the patterned member 115 may alternatively be disposed on one or more inner surfaces of the housing 110 and, depending on the embodiment, also on the inner surface (upper surface) of the outer shell 190.

[0087] Figure 7 1 shows a patterned member 115 according to a preferred embodiment of the present invention, and Figure 8 Shown in detail Figure 7 The patterned member 115 depicted in FIG. Fig.11 is a diagram describing a path of light reflected from a protrusion 1151 according to the present invention.

[0088] As shown in the figure, the patterned member 115 is preferably configured such that protrusions 1151 are repeatedly arranged back and forth (along the Z axis), and each protrusion 1151 extends longitudinally along a direction (Y axis) perpendicular to the optical axis (Z axis).

[0089] Considering the orientation and angle of incident light entering the image sensor 30 after passing through the lens module R and reflecting off the inner surface of the housing 110 , each protrusion 1151 preferably has a triangular cross-section (in the XZ plane) as shown.

[0090] More preferably, the protrusion 1151 includes a vertical surface 1151A standing perpendicular to the inner surface of the housing 110 (and rising from the inner surface of the housing 110 in the X-axis direction) and an inclined surface 1151B whose surface is directed toward the image sensor 30 .

[0091] That is, the protrusion 1151 generally protrudes forward from the inner surface of the shell 110 toward the inside, the front side of each protrusion (relative to the Z axis) stands perpendicular to the inner surface of the shell 110, and the rear side of each protrusion is inclined to form an inclined surface 1151B facing the image sensor 30.

[0092] Constructing the protrusion 1151 as described above provides an effective means for directing light directly incident on the vertical surface 1151A to be reflected away in a direction opposite to the incident direction, such as Fig.11 shown.

[0093] In addition, the rear side of the protrusion 1151 is arranged into a repeated array of inclined surfaces 1151B, wherein two consecutive protrusions 1151 can form a pair of ridges and valleys. Such a configuration can widen the area of ​​the inner surface of the housing 110 facing the light emitted from the lens module R, and this widening contributes to further attenuation of the power of the light.

[0094] Furthermore, such a configuration allows incident light falling between two consecutive ridges to be refracted away from the image sensor 30 by being reflected off the vertical surface 1151A of the rear protrusion 1151 of the consecutive pair.

[0095] In addition, since the portion of light refracted by the vertical surface 1151A of the rear protrusion 1151 is guided toward subsequent refraction through the inclined surface 1151B of the continuously centered front protrusion 1151, resulting in a reflection angle greater than the first incident angle, the component of light directly entering the image sensor 30 can be minimized.

[0096] In order to effectively guide the refracted light not to return to the image sensor 30, it is most preferred that the angle between the inclined surface 1151B and the inner surface of the housing 110 is 45 degrees or less.

[0097] In some embodiments, the patterned member 115 is preferably subjected to surface treatment, such as laser etching (corrosion), arc discharge and chemical treatment, to roughen its exposed surface. Such a surface-treated patterned member 115 can attenuate the reflection behavior of light as a whole due to the fine (several micrometers) cracks formed on its surface.

[0098] Since the patterned component 115 of the present invention relies on a structure or shape formed on the shell 110 itself for attenuating light reflection as described above, and does not rely on the use of foreign materials such as fibers, films or coatings, its production can be easily integrated into the manufacturing process of the shell 110 by molding (injection, press fitting, etc.), thereby producing a patterned component 115 made integrally with the shell 110.

[0099] The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present disclosure, are given by way of illustration only, as various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art from the detailed description.

[0100] In the above description of the present specification, terms such as “first” and “second” are merely conceptual terms for relatively identifying components with each other, and thus they should not be construed as terms for indicating a specific order, priority, and the like.

[0101] In order to emphasize or highlight the technical content of the present disclosure, the drawings used to illustrate the present disclosure and its embodiments may be shown in a slightly exaggerated form, but it should be understood that without departing from the scope of the present invention, those skilled in the art may make various modifications taking into account the above description and the illustrations of the drawings.

Claims

1. A camera actuator, comprising: a lens module that emits light toward the image sensor; a housing, the housing surrounding the lens module; as well as a patterned member disposed on an inner flat surface of the housing, the inner flat surface being an inner flat surface between the lens module and the image sensor; wherein the patterned member comprises protrusions, and the protrusions are repeatedly arranged back and forth along the optical axis, Each protrusion is constructed as follows: It extends longitudinally in a direction perpendicular to the optical axis and has a triangular cross-section, and comprises: a vertical surface that is perpendicular to the inner planar surface of the housing; and an inclined surface, the surface of the inclined surface being directed toward the image sensor, and Wherein, adjacent protrusions among the protrusions are arranged to be spaced apart from each other. 2 . The camera actuator according to claim 1 , further comprising a reflectometer module which is disposed in front of the lens module and reflects light from an object toward the lens module.

3. The camera actuator according to claim 1, wherein: The exposed surface of the patterned member is subjected to a roughened surface treatment.

4. The camera actuator according to claim 1, wherein: The patterned member is formed integrally with the housing.

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