Abstract:
Disclosed herein is a camera module comprising: a circuit board; a frame coupled to the circuit board; an image sensor on the circuit board; a bobbin on the frame, a plurality of lenses being inside the bobbin; a coil wound on the bobbin, the bobbin moving to two directions based on a current applied to the coil; a magnet configured to interact the coil; and a yoke on the frame, the magnet being at an inner side of the yoke, wherein the bobbin moves to a first direction when a forward current is applied to the coil and to a second direction when a reverse current is applied to the coil.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. application Ser. No. 12/974,675, filed Dec. 21, 2010, which claims the benefit under 35 U.S.C. §119 of Korean Patent Application No. 10-2009-0128159, filed on Dec. 21, 2009, which are hereby incorporated by reference in their entirety. 
     
    
     BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a mobile phone installed with a camera module. 
         [0004]    2. Description of the Related Art 
         [0005]    Concomitant with the development of recent communication and digital information processing technologies, a mobile phone technique integrated with information processing and computations, communications, and image information input/output has newly emerged. 
         [0006]    Consistent with this, a mobile phone merged with a camera function has commercialized, at which system the mobile phone installed with a camera module photographs and stores moving images and still images and transfers them to the other party. 
         [0007]    A mobile phone installed with such a camera module simply does not remain in a function of shooting an object, but is actually in a stage of adding an accessory function like a focus function of adjusting a focus of objects to be shot and a zoom function of making an object in the distance appear a near-sight or a close positioned object coming into a far distance. 
         [0008]    A conventional lens unit of a camera module moves upward/downward along with an optical axis by a VCM (Voice Coil Motor), and through such an action, a camera module can do an auto focusing of a focal point of an object. 
         [0009]    At this time, an upper part and a lower part of a lens unit is installed with an upper spring and an lower spring, and in a case a force applied to a lens part by a voice coil motor is greater than tension of a spring, a lens unit moves in an optical axis direction. 
         [0010]    A camera module-installed mobile phone may operate in “vibration mode” vibrating by drive of a vibration motor, where a spring supporting a lens unit may rock simultaneously when a mobile phone is trembling due to a vibration mode. 
         [0011]    When a spring supporting a lens unit rocks, so does a lens unit, whereby a banging sound occurs in a vibration mode as the lens unit touches a bottom surface. 
       BRIEF SUMMARY 
       [0012]    The present invention provides a mobile phone installed with a camera module configured to inhibit a thud noise occurring due to a lens unit in a vibration mode of a mobile phone. 
         [0013]    In one general aspect of the present invention, there may be provided a camera module, the camera module comprising: a circuit board; a frame coupled to the circuit board; an image sensor on the circuit board; a bobbin on the frame, a plurality of lenses being inside the bobbin; a coil wound on the bobbin, the bobbin moving to two directions based on a current applied to the coil; a magnet configured to interact the coil; and a yoke on the frame, the magnet being at an inner side of the yoke, wherein the bobbin moves to a first direction when a forward current is applied to the coil and to a second direction when a reverse current is applied to the coil. 
         [0014]    In some exemplary of the present invention, the magnet may be between the yoke and the coil. 
         [0015]    In some exemplary of the present invention, the first direction may include a direction distancing from the frame along an optical axis and the second direction may include a direction approaching the frame along the optical axis. 
         [0016]    In some exemplary of the present invention, the camera module may further comprising: a first tension member at upper part of the bobbin; and a second tension member on the frame, wherein the second tension member is place below the bobbin. 
         [0017]    In some exemplary of the present invention, outside part of the first tension member may be supported by an upper side of the yoke, and inside part of the first tension member may face the bobbin. 
         [0018]    In some exemplary of the present invention, the either side of the second tension member may be spaced from the frame. 
         [0019]    In some exemplary of the present invention, the second tension member may be isolated from the yoke. 
         [0020]    In some exemplary of the present invention, the first tension frame may apply pressure to the upper part of the bobbin. 
         [0021]    In some exemplary of the present invention, the camera module may further comprise a filter laid over the image sensor and below the bobbin, and configured to filter infrared inputted to the image sensor. 
         [0022]    In some exemplary of the present invention, the camera module may further comprise a case supported by the frame. 
         [0023]    In another general aspect of the present invention, there may be provided a mobile terminal comprising a camera module and a vibration control unit, wherein the camera module comprising; a circuit board; a frame coupled to the circuit board; an image sensor disposed on the circuit board; a bobbin on the frame, a plurality of lenses being inside the bobbin; a coil wound on the bobbin, the bobbin moving to two directions based on a current applied to the coil; a magnet configured to interact the coil; and a yoke disposed on the frame, the magnet being at an inner side of the yoke, and wherein the vibration control unit may be configured to output a first control signal and a second control signal when a signal for a vibration mode is inputted and a reverse current is applied to the coil according to the second control signal. 
         [0024]    In some exemplary of the present invention, the mobile terminal may further comprise a vibration motor unit configured to vibrate the mobile terminal by driving a motor according to the first control signal from the vibration control unit. 
         [0025]    In some exemplary of the present invention, the mobile terminal may further comprise an actuator drive unit configured to apply the reverse current to the coil according to the second control signal. 
         [0026]    In some exemplary of the present invention, the yoke may comprise an upper plate and a lateral plate extended from an edge of the upper plate, and the magnet may be coupled to the lateral plate. 
         [0027]    In some exemplary of the present invention, the frame may further comprise a supporter extended toward the image sensor from a peripheral portion of the frame. 
         [0028]    An embodiment of the invention applies a reverse current to an actuator driving a lens unit of a camera module and thus extremely pushes a lens unit onto a tension member placed at a lower part, so that a banging sound occurring by movement of a lens unit in a vibration mode can be inhibited. 
         [0029]    In addition, the present invention provides a mobile phone including, an actuator moving a lens; a vibration control unit outputting a first control signal and a second control signal; a vibration motor unit vibrating the mobile phone by driving a motor, when the first control signal is input, connected to the vibration control unit; and an actuator drive part applying the current to the actuator when the second control signal is input, connected to the vibration control unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]      FIG. 1  is an outer shape diagram of a mobile phone according to an embodiment of the present invention; 
           [0031]      FIG. 2  is a cross-section view of a camera module according to an embodiment of the present invention; and 
           [0032]      FIG. 3  is a schematic construction diagram of a central control unit and an actuator of a mobile phone according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    Since the present invention can be applied with various changes thereto and several types of embodiments, specific embodiments intend to be exemplified in the drawings and minutely described in the detailed description. However, it should not be appreciated in a limiting sense of limiting the present invention to a specific example but to include all the changes, equivalents and replacements which fall in the spirit and technical scope of the present invention. 
         [0034]    While terms including ordinal numbers such as a first and a second may be used to describe various components, such components are not limited to the terms. The terms are used only for the purpose of distinguishing one component from other components. 
         [0035]    For example, a second component may be named as a first component without departing from the scope of the present invention rights, and in a similar way, the first component may be renamed as the second component. 
         [0036]    Stated that any component is “connected” or “conjunctive” to another component, it will be appreciated to be directly connected or conjunctive to the very another component or otherwise that there exists any component in the midst of them. On the other hand, stating that any component is “directly connected” or “directly conjunctive” to another component, it should be understood that any other component does not exist therebetween. 
         [0037]    Terms used in the present application are only used to describe a specific embodiment, not in a sense of limiting the invention. A singular form includes a plural form, otherwise stated in a different way in the context. In this application, the terms such as “include” or “have” indicate that there exist a characteristic, a number, a step, an operation, a component, other things recited in the specification or a combination thereof, but it should not be understood to preclude the existence or addition of one or more other characteristics, numbers, operations, substances, components or a combination of thereof. 
         [0038]    In the following, a mobile phone according to an embodiment of the present invention will be described in detail referring to the attached drawings, but without regard to a drawing sign, an identical or corresponding component is assigned the same reference numeral and a redundant description regarding this will be omitted. 
         [0039]      FIG. 1  is an outer shape diagram of a mobile phone according to the present invention. As shown in  FIG. 1 , a mobile phone includes a main body  200  and a camera module  100  mounted at a setting position of the main body  200 . 
         [0040]      FIG. 2  is a cross-sectional view of a camera module  100  according to an embodiment of the invention. 
         [0041]    As shown in  FIG. 2 , a camera module  200  of the present invention includes a case  10 , an upper part tension member  20 , a lens barrel  30 , an actuator  40 , a lower part tension member  50 , a frame  60 , an IR filter  70 , an image sensor  80  and a printed circuit board  90 . 
         [0042]    For auto focusing, an actuator  40 , that is an operating unit shifting a lens barrel  30  along with an optical axis direction  0 , is necessary, in which the present invention is a voice coil motor among actuators  40 . 
         [0043]    An actuator  40  includes a bobbin  41 , a coil  42 , a permanent magnet  43 , and a yoke  44 . 
         [0044]    A case  10  has a cubical form with its lower part opened, and an upper part central side is formed with a light penetration hole  11 . A lower part of a case  10  is supported by a frame  60 . 
         [0045]    The case  10  is coupled with a frame  60  to form a frame  60 , and the space includes an upper part tension member  20 , a lens barrel  30 , an actuator  40 , and an IR filter  50 . 
         [0046]    It is preferred that a case  10  is manufactured with plastic for an insulation between its inner part and outer part, and an injection molding for mass production is possible. 
         [0047]    An upper part tension member  20  is a plate spring, being inserted into an upper part of a case  10 , and its outside part is supported by a yoke  44  of an actuator  40 , and its inside part faces a bobbin  41  of an actuator  40  and applies pressure to an upper side of a bobbin  41 . 
         [0048]    A lower part tension member  50  may be into an insert injection at a bobbin  41 , and may be pasted with a bond. 
         [0049]    A lens barrel  30  is a means of fixing and protecting a plurality of lenses, an inner side of a lens barrel  30  is stacked with a plurality of lens capable of inputting a light image of a subject sequentially according to an optical axis direction  0 . 
         [0050]    A surrounding surface of a lens barrel  30  is formed of a screw thread  31 , and the screw thread  31  is screw-coupled to a screw thread formed at an inner-rim surface of a bobbin  41 . 
         [0051]    The bobbin  41  is of a cylindrical shape with its upper part and lower part opened, and the inner-rim surface is formed with a screw thread corresponding to a screw thread  31  of a lens barrel  30 . The present invention may take the far distance focusing of a camera module by screw-coupling a lens barrel  30  to an inner-rim surface of a bobbin  41 . 
         [0052]    A surrounding part of a bobbin  41  is wound perpendicular to the direction of magnetic flux by a coil  42  interacting with a permanent magnet  43 . 
         [0053]    An inner side of a case  10  is inserted with a yoke  44  for keeping magnetic field between a coil  42  and a permanent magnet  43  from leaking from outside, and a permanent magnet  43  is mounted at an inner side of a yoke  44  to face each other based on a bobbin  41 . The yoke  44  is supported by a frame  60 . 
         [0054]    When a voltage is applied to a coil  42 , current flowing through the coil and magnetic field of a permanent magnet  43  interact (Fleming&#39;s left-hand rule), and thus a bobbin  41  is inflicted with a force towards an upper side of an optical axis direction. At this time, the greater the intensity of current applied to the coil  42  is, a distance a lens barrel  30  and a bobbin  41  shift to an upper part along an optical axis direction increases. 
         [0055]    Successively, when a voltage applied to a coil  42  is blocked, a lens barrel  30  and a bobbin  41  shift to a lower part along with an optical axis direction by an upper part tension member  20  and a lower part tension member  50  and return to its original state. 
         [0056]    A printed circuit board  90  is mounted with an image sensor  80  transforming a light image into an electrical signal, and a frame  60  is a rectangular shape having a central opening part that can penetrate a light to an image sensor  80 , and the frame  60  is positioned at a lower part of a lens barrel  30 , and mounted with an IR filter  70  filtering infrared. 
         [0057]    An image sensor  80  is placed at a lower part of a lens barrel  30  and at an upper part of a printed circuit board  90 , and transforms a light image incident through a plurality of lens into an electrical signal. 
         [0058]    The printed circuit board  90  is an FPCB (Flexible Printed Circuit Board) having a high evenness level, an outwardly extended part from an FPCB is provided with means connected to an external device (not shown). 
         [0059]    As described above, a lens barrel  30  of the present invention is supported by elasticity force between an upper part tension member  20  and a lower part tension member  50 . 
         [0060]      FIG. 3  is a schematic construction view of a central control part  300  and an actuator  40  of a mobile phone according to an embodiment of the invention. 
         [0061]    As illustrated in  FIG. 3 , a central control part  300  of a mobile phone of the invention includes a vibration control part  310  controlling vibration of a mobile phone, a vibration motor part  320  receiving an electric source voltage according to a control signal of the vibration control part  310  and driving a mobile phone in a vibration mode, and an actuator drive part  330  driving the actuator  40  of a camera module. 
         [0062]    The vibration control part  310  processes a signal input from an external and determines if a mobile phone should be operated in a vibration mode, and if a mobile phone needs to be operated in a vibration mode, outputs a first control signal to the vibration motor part  320 . 
         [0063]    Then, the vibration motor part  320  drives a motor so that a mobile phone vibrates according to a first control signal. 
         [0064]    If a signal telling of operating in a vibration mode from outside is input like in the case of a vibration mode when a call is terminated or in a case a user manipulates a keypad to convert a bell mode into a vibration mode, a vibration control part  310  outputs a first control signal and a second control signal informing of a vibration mode initiation to a vibration motor part  320  and an actuator drive part  330 , respectively. 
         [0065]    An actuator drive part  330  applies “forward current” to the coil  42  of an actuator  40  at the time of auto focusing action, but if a second control signal from the vibration control part  310  is input, it applies “reverse current” to the coil  42  of an actuator  40 . 
         [0066]    If a reverse current is applied to the coil  42 , a bobbin  41  of an actuator  40  is inflicted with a force toward a lower side of an optical axis direction by Fleming&#39;s left-hand rule. Then, a lens barrel  30  including a lens unit connected to a bobbin  41  is maximally pushed to a lower part tension member  50 , thereby presumably inhibiting a banging sound occurring according to the falter of a lens unit in a vibration mode of a mobile phone. 
         [0067]    A circuit of applying a forward current and a reverse current to the actuator  40  may be variously realized, and a related specific description will be omitted. 
         [0068]    The vibration control part  310  may output simultaneously a first control signal and a second control signal, but it may output a first control signal a pre-defined time after a second control signal is outputted. 
         [0069]    A vibration control part  310  of the present invention may set a certain time interval while a second control signal is output and afterwards a first control signal is output, so that a vibration mode after a lens barrel  30  is maximally pushed to a lower part tension member  50  may be initiated and a banging sound occurring according to the falter of a lens unit may be inhibited. At this time, a certain time interval is a time required so that a lens barrel  30  closely couples to a lower part tension member  50 . 
         [0070]    While the present invention has been described in detail through representative embodiments in the above part, those skilled in the art would understand that various modifications can be made in the described embodiment without departing from the scope of the present invention.