Patent Publication Number: US-9900483-B2

Title: Camera module

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 15/075,820, filed Mar. 21, 2016; which is a continuation of U.S. application Ser. No. 13/990,532, filed May 30, 2013, now U.S. Pat. No. 9,319,573, issued Apr. 19, 2016; which is the U.S. National Stage Application of International Patent Application No. PCT/KR2011/008635, filed Nov. 11, 2011; which claims priority to Korean Application No. 10-2010-0122909, filed Dec. 3, 2010, the disclosures of each of which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The teachings in accordance with exemplary embodiments of this invention relate generally to a camera module, and more particularly to a camera module having a structure capable of being miniaturized and light-weighted. 
     BACKGROUND ART 
     A camera module is recently applied to various multimedia fields including notebook type personal computers, camera phones, PDAs (Personal Digital Assistants), smart phones and toys, and to image input equipment including monitoring cameras and information terminals. 
     A PCB (Printed Circuit Board) of a camera module is manufactured being embedded with various electronic elements, and the electronic elements are generally configured with integrated modules on the PCB. The camera module used on the PCB is frequently mounted with an actuator for automatic focus adjustment generally using a VCM (Voice Coil Motor) method. 
     In order for the camera module mounted with an VCM actuator to be used for a mobile terminal, light-weightiness and slimness required for design must be accomplished. Meantime, although size of a camera module is basically limited by that of a VCM assembly, there is a disadvantage that even if the size is reduced, no part can be omitted as long as function of the VCM assembly has to be maintained. 
       FIG. 1  is a schematic structural view of a camera module according to prior art. Referring to  FIG. 1 , the conventional camera module includes a PCB ( 11 ) mounted with an image sensor ( 12 ), a base ( 20 ) on the PCB ( 11 ), upper and lower spring plates ( 30 ,  60 ), a spacer ( 40 ), a cover ( 70 ), a lens assembly ( 51 ), a bobbin ( 52 ), a lens actuator ( 50 ) including a coil ( 53 ) and a yoke ( 54 ) and a shield can ( 80 ). 
     That is, the cover ( 70 ) structurally takes a shape of an enclosure formed with a bottom-opened inner space, and accommodates the upper/lower spring plates ( 30 ,  60 ) and the lens actuator ( 500 ) at the inner space. 
     DETAILED DISCLOSURE 
     Technical Problem 
     The present invention is to provide a camera module directed to solve the aforementioned problems or disadvantages by changing the structure of a cover to correct a coupled relationship between an actuator and a base, whereby a miniaturization of the camera module can be accomplished. 
     Technical problems to be solved by the present invention are not restricted to the above-mentioned, and any other technical problems not mentioned so far will be clearly appreciated from the following description by skilled in the art. 
     Technical Solution 
     An object of the invention is to solve at least one or more of the above problems and/or disadvantages in whole or in part and to provide at least the advantages described hereinafter. In order to achieve at least the above objects, in whole or in part, and in accordance with the purposes of the invention, as embodied and broadly described, and in one general aspect of the present invention, there is provided a camera module, the camera module comprising: a PCB; an image sensor mounted on the PCB; a base mounted on the PCB and including a lower plate portion with an opening centrally mounted with an IR (infrared) filter, and a lower pillar portion erected at a corner portion of the lower plate portion; a lower spring plate arranged at an upper surface of the lower plate portion of the base and formed with an elastic support portion; a lens actuator including a bobbin elastically supported by the elastic support portion of the lower spring plate and accommodated inside with a lens assembly, and a yoke wrapping a periphery of the bobbin and secured onto the base; an upper spring plate having an elastic support portion coupled to an upper surface of the lens actuator to elastically support the bobbin; and a cover arranged on an upper surface of the upper spring plate and including an upper plate portion formed with an upper hole, and an upper pillar portion perpendicularly formed on a corner of the upper plate portion to be coupled to the lower pillar portion, wherein the yoke pinched by the base and the cover to expose an external wall between the mutually-coupled lower pillar portion of the base and the upper pillar portion of the cover. 
     Preferably, the camera module is further comprising a shield can of an enclosure centrally formed thereon with a hole and a bottom-opened inner space, accommodating the cover, the upper/lower spring plates, and the lens actuator at the inner space, and secured at a bottom end to an upper surface of the PCB. 
     Preferably, the lower spring plate is formed with a metal conductor to be electrically connected to a circuit of the PCB. 
     Preferably, the lower spring plate is electrically divided to a pair, each pair being connected to a power line of a different polarity. 
     Preferably, the each pair of the lower spring plate is opposite to the other pair. 
     Preferably, each pair of the lower spring plate is formed with a yoke terminal protruded toward the PCB to provide a power to the lens actuator. 
     Preferably, the camera module is further comprising an insulated spacer between the lower spring plate and a yoke of the lens actuator. 
     Preferably, a lower end portion of the shield can is fixedly bonded to an upper surface of the PCB by an adhesive. 
     In another general aspect of the present invention, there is provide a camera module, the camera module comprising: a PCB; an image sensor mounted on the PCB; a base mounted on the PCB and including a lower plate portion with an opening centrally mounted with an IR (infrared) filter, and a lower pillar portion erected at a corner portion of the lower plate portion; a lower spring plate arranged at an upper surface of the lower plate portion of the base and formed with an elastic support portion; a lens actuator including a bobbin elastically supported by the elastic support portion of the lower spring plate, accommodated inside with a lens assembly and wound with a coil, and a yoke mounted with a magnet at a position opposite to the bobbin and arranged opposite to the bobbin wound with the coil; an upper spring plate coupled to an upper surface of the lens actuator to elastically support the bobbin; a cover arranged on an upper surface of the upper spring plate and including an upper plate portion formed with an upper hole, and an upper pillar portion perpendicularly formed on a corner of the upper plate portion to be coupled to the lower pillar portion; a metal shield can of an enclosure centrally formed thereon with a hole and a bottom-opened inner space, accommodating the cover, the upper/lower spring plates, and the lens actuator at the inner space, and secured at a bottom end to an upper surface of the PCB, wherein the base and the cover are supplementarily coupled at each corner portion, and the yoke is exposed from a space formed by the lower pillar portion of the base and the upper pillar portion of the cover. 
     Preferably, the lower spring plate is formed with a metal conductor to be electrically connected to a circuit of the PCB. 
     Preferably, the lower spring plate is electrically divided to a pair, each pair being connected to a power line of a different polarity. 
     Preferably, the each pair of the lower spring plate is opposite to the other pair. 
     Preferably, each pair of the lower spring plate is formed with a yoke terminal protruded toward the PCB to provide a power to the lens actuator. 
     Preferably, the camera module is further comprising an insulated spacer between the lower spring plate and a yoke of the lens actuator. 
     Preferably, the yoke of the lens actuator is coated with an insulating member. 
     Preferably, a lower end portion of the shield can is fixedly bonded to an upper surface of the PCB by an adhesive. 
     Preferably, each thickness at the thickest portion of the lower pillar portion and the upper pillar portion is same, where a surface contacted by the lower pillar portion and the upper pillar portion takes a shape of a step. 
     Advantageous Effects 
     A camera module according to the present invention has an advantageous effect in that a cover and a base are structurally changed to enable miniaturization and light-weightiness of the camera module. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a schematic structural view of a camera module according to prior art 
         FIG. 2  is a schematic view of a camera module according to an exemplary embodiment of the present invention; 
         FIG. 3  is a schematic perspective view illustrating a base according to an exemplary embodiment of the present invention; 
         FIG. 4  is a schematic perspective view of a camera module according to an exemplary embodiment of the present invention; and 
         FIG. 5  is a schematic view illustrating the lower spring plate according to an exemplary embodiment of the present invention. 
     
    
    
     BEST MODE 
     The following description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the following teachings, and skill and knowledge of the relevant art are within the scope of the present invention. The embodiments described herein are further intended to explain modes known of practicing the invention and to enable others skilled in the art to utilize the invention in such, or other embodiments and with various modifications required by the particular application(s) or use(s) of the present invention. 
     The disclosed embodiments and advantages thereof are best understood by referring to  FIGS. 1-5  of the drawings, like numerals being used for like and corresponding parts of the various drawings. Other features and advantages of the disclosed embodiments will be or will become apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional features and advantages be included within the scope of the disclosed embodiments, and protected by the accompanying drawings. Further, the illustrated figures are only exemplary and not intended to assert or imply any limitation with regard to the environment, architecture, or process in which different embodiments may be implemented. Accordingly, the described aspect is intended to embrace all such alterations, modifications, and variations that fall within the scope and novel idea of the present invention. 
     It will be understood that the terms “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof. That is, the terms “including”, “includes”, “having”, “has”, “with”, or variants thereof are used in the detailed description and/or the claims to denote non-exhaustive inclusion in a manner similar to the term “comprising”. 
     Furthermore, “exemplary” is merely meant to mean an example, rather than the best. It is also to be appreciated that features, layers and/or elements depicted herein are illustrated with particular dimensions and/or orientations relative to one another for purposes of simplicity and ease of understanding, and that the actual dimensions and/or orientations may differ substantially from that illustrated. That is, in the drawings, the size and relative sizes of layers, regions and/or other elements may be exaggerated or reduced for clarity. Like numbers refer to like elements throughout and explanations that duplicate one another will be omitted. Now, the present invention will be described in detail with reference to the accompanying drawings. 
     Words such as “thereafter,” “then,” “next,” etc. are not intended to limit the order of the processes; these words are simply used to guide the reader through the description of the methods. 
     It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other elements or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items and may be abbreviated as “/”. 
     It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first region/layer could be termed a second region/layer, and, similarly, a second region/layer could be termed a first region/layer without departing from the teachings of the disclosure. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the general inventive concept. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. 
     Now, the camera module according to exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
       FIG. 2  is a schematic view of a camera module according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 2 , a camera module according to an exemplary embodiment of the present invention includes a PCB ( 110 ), an image sensor ( 120 ), a base ( 200 ), upper and lower spring plates ( 300 ,  600 ), a lens assembly and a lens actuator ( 500 ), a cover ( 700 ), and a shield can ( 800 ). 
     The PCB ( 110 ) is mounted with the image sensor ( 120 ), and coupled by the base ( 200 ) and a lower surface of the can ( 800 ). The image sensor ( 120 ) is mounted with an image pickup device for converting light incident through a lens formed at a lens assembly ( 510 ) positioned at an upper surface of the image sensor ( 120 ) to an electrical signal. 
     The base ( 200 ) mounted on the PCB ( 110 ) is formed with a lower plate portion ( 210 ) formed with an opening mounted with an IR filter ( 250 ) filtering an infrared, and a lower pillar portion ( 220 ) perpendicularly formed at a corner portion of the lower plate portion ( 210 ). The lower pillar portion ( 220 ) is formed at a distal end thereof in a staircase having a large cross section portion ( 220   a ) and a small cross section portion ( 220   b ) integrally extended from the large cross section portion ( 220   a ). The base ( 200 ) formed with the lower plate portion and lower pillar portion ( 210 ,  220 ) is illustrated in  FIG. 3 . 
     The lower spring plate ( 300 ) is coupled to an upper surface of the lower plate portion ( 210 ) at the base ( 200 ) and is inwardly formed with an elastic support portion. The lower spring plate ( 300 ) and the base are mutually arranged as exemplarily illustrated in  FIG. 3 . 
     The lens actuator ( 500 ) includes a lens assembly ( 510 ), a bobbin ( 520 ) accommodating the lens assembly ( 510 ), a coil wound on a periphery of the bobbin ( 520 ) and the yoke ( 540 ), which are elements for vertically driving the lens assembly ( 510 ). 
     The yoke ( 540 ) is secured to the base ( 200 ), while the bobbin ( 520 ) is not secured to the yoke ( 540 ) but elastically supported by the elastic support portion of the lower spring plate ( 300 ) with a capacity of vertical movement. The upper spring plate ( 600 ) is coupled to an upper surface of the lens actuator ( 500 ) and formed with an elastic support portion elastically supporting the bobbin ( 520 ). 
     The cover ( 700 ) is arranged at an upper surface of the upper spring plate ( 600 ) and includes an upper plate portion ( 710 ) formed with an upper hole ( 730 ) and an upper pillar portion ( 720 ) vertically and downwardly formed at a corner of the upper plate portion ( 710 ). The upper pillar portion ( 720 ) mutually coupled to the lower pillar portion ( 220 ) of the base ( 200 ) allows the cover ( 700 ) to be coupled to the base ( 200 ). 
     Thus, the yoke ( 540 ) is pinched by the base ( 200 ) and the cover ( 700 ) to structurally expose an external wall between the mutually-coupled lower pillar portion ( 220 ) and the upper pillar portion ( 720 ). The coupled relationship between the upper and lower pillar portions ( 220 ,  720 ) and the laterally exposed structure of the yoke ( 540 ) are clearly illustrated by  FIG. 4 . 
     Although  FIG. 2  has not clearly illustrated the coupled relationship between the upper and lower pillar portions ( 220 ,  720 ),  FIG. 2  illustrates a detailed description of an inner structure of the camera module, such that the coupled relationship between the upper and lower pillar portions ( 220 ,  720 ) can be correspondingly described by a lateral cross-sectional view along line A-A. 
     In comparison between  FIG. 1  of prior art and  FIG. 2  according to the present invention, a center portion of a lateral wall of the cover ( 70 ) in  FIG. 1  is not shown in  FIG. 2 , whereby there is an effect of a width of the camera module being reduced as much. Of course, as mentioned above, the coupling of the cover ( 700 ) and the base ( 200 ) is accomplished by the upper and lower pillar portions ( 720 ,  220 ) formed at the corner portion. 
     Therefore, the present invention has an effect of reducing the size of a camera module through a structural change, while maintaining the same function and structural strength as those of the VCM actuator. 
     MODE FOR INVENTION 
     Meanwhile, the shield can ( 800 ) may be coupled to an external side of the cover ( 700 ) to shield the EMI (Electromagnetic Interference). The shield can ( 800 ) is an enclosure formed at an upper center thereof with a hole and a bottom-opened inner space, accommodates the cover ( 700 ), the lower and upper spring plates ( 300 ,  600 ) and the lens actuator ( 500 ) at the inner space, and fixed at a bottom end to an upper surface of the PCB ( 110 ) by an adhesive. The adhesive may preferably include a conductive epoxy, but is not limited thereto. 
     The lower spring plate ( 300 ) is formed with a conductive metal, arranged at an upper surface of the lower plate portion ( 210 ) and electrically connected to a circuit of the PCB ( 110 ). 
     The lower spring plate ( 300 ) is electrically divided into a pair, each pair being connected to a power line of a different polarity. The each pair of the lower spring plate may be opposite to the other pair as shown in  FIGS. 3 and 5 . 
     As illustrated in  FIG. 5 , each pair of the lower spring plate ( 300 ) may be formed with a yoke terminal ( 310 ) protruded toward the PCB to provide a power to the lens actuator ( 500 ). That is, the yoke terminal ( 310 ) is inserted into a connection hole of the yoke ( 540 ) at the lens actuator ( 500 ) and electrically connected to the PCB ( 110 ) through the lower spring plate ( 300 ), whereby a power can be supplied to the lens actuator ( 500 ). 
     An insulated spacer is formed between the lower spring plate ( 300 ) and a yoke ( 540 ) of the lens actuator ( 500 ) to further increase insulation and air-tightness. 
     The previous description of the present invention is provided to enable any person skilled in the art to make or use the invention. Various modifications to the invention will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the invention. Thus, the invention is not intended to limit the examples described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. 
     INDUSTRIAL APPLICABILITY 
     The camera module according to the present invention has an industrial applicability in that the novel idea of the present invention can be applied to a small-sized camera module using a voice coil motor as an automatic focus adjusting unit.