Abstract:
A card connector comprises: an ejection mechanism having an ejection member for ejecting a card; a locking piece displaceable vertically of the connector housing and adapted to fix the ejection member, when the card is loaded, to restrict the movement of the ejection member in the card ejection direction; and an releasing means for unlocking the locking piece in response to the card ejection operation.

Description:
[0001]    This application is based on Patent Application No. 2000-319891 filed Oct. 19, 2000 in Japan, the content of which is incorporated hereinto by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to a card connector mounted on electronic devices, such as cellular phones, telephones, PDAs (personal digital assistants), portable audio devices and cameras, and more specifically to a structure for locking a card ejection mechanism ejecting a card when the card is loaded.  
           [0004]    2. Description of the Related Art  
           [0005]    In electronic devices such as cellular phones, telephones, PDAs and cameras, a variety of functions are added by loading an IC card with a built-in CPU or memory IC, such as a SIM (subscriber identity module) card, an MMC (multimedia card) (trademark), an SD (super density) card, a Memory Stick (trademark) and a Smart Media (trademark).  
           [0006]    The connector structure for removably accommodating such an IC card has a plurality of contact terminals in a connector housing that are connected to a variety of signal processing circuits and a power supply circuit of the electronic device on which the connector is mounted. These contact terminals are brought into contact with a plurality of contact pads formed on a front or back surface of the loaded IC card, causing the IC card to be electrically connected to the electronic device on which the connector is mounted.  
           [0007]    Many of such card connectors have an ejection mechanism for withdrawing the loaded IC card from the connector.  
           [0008]    A proposed system of this ejection mechanism is shown in FIG. 13.  
           [0009]    The card connector shown in FIG. 13 has an ejection member  102  urged in an ejection direction by coil springs  100  to eject a card  101 , a looking piece  103  adapted to engage with a locking projection  102   a  formed at an end of the ejection member  102  to restrict the movement of the ejection member  102  in the ejection direction, and an ejection button  104  for releasing the restriction imposed by the locking piece  103  to allow the card to be ejected. At the locking piece  103  is formed an engagement hole  103   a  for fixing the locking projection  102   a . The ejection button  104  is urged in the ejection direction by a coil spring  105 . The ejection button  104  has a cam surface  104   a  that displaces a front end of the locking piece  103  in a lateral direction C.  
           [0010]    In the construction described above, with the card  101  loaded in the connector and the ejection member  102  held immovable by the locking piece  103  as shown in FIG. 13, when the ejection button  104  is depressed, the pressing force from the cam surface  104   a  displaces the front end of the locking piece  103  away from the locking projection  102   a , disengaging the ejection member  102  from the locking piece  103 , with the result that the ejection member  102  moves in the ejection direction by the force of the coil springs  100 , which allows the loaded card  101  to extrude out of the connector.  
           [0011]    There is a growing demand on the card connector of this kind for size reduction as the electronic devices are becoming smaller and smaller. To meet this demand a variety of parts need to be laid out efficiently in a small space.  
           [0012]    In the card connector described above, however, since the front end of the locking piece  103  is displaced in the lateral direction C of the connector housing, it is necessary to secure a space in which to displace the locking piece  103  laterally. Further, the cam surface  104   a  of the ejection button  104  needs to be extended in the lateral direction C, which results in an increase in the width of the connector housing in the lateral direction C and therefore there are some problems that the mounting area of the connector increases.  
         SUMMARY OF THE INVENTION  
         [0013]    The present invention has been accomplished under these circumstances and its primary object is to provide a card connector which can reduce the width of its connector housing and therefore the card mounting area.  
           [0014]    According to one aspect, the present invention provides a card connector for holding a card in a connector housing in such a way that a plurality of contact pads provided on a bottom surface of the card are in contact with contact terminals arranged in the connector housing. The card connector comprises: an ejection mechanism having an ejection member, the ejection member being adapted to move in a card insertion direction as the card is inserted into the connector housing, and move in a card ejection direction in response to a card ejection operation to eject the card; a locking piece displaceable vertically of the connector housing and adapted to fix the ejection member, when the card is loaded, to restrict the movement of the ejection member in the card ejection direction; and an releasing means for unlocking the locking piece in response to the card ejection operation.  
           [0015]    As described above, because the locking piece for locking the ejection member is displaced vertically of the connector housing to lock or unlock the ejection member, the present invention makes it possible to reduce the width of the connector housing and therefore the mounting area of the connector housing.  
           [0016]    The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    [0017]FIG. 1 is a perspective view showing an external construction of a card connector in one embodiment of the present invention;  
         [0018]    [0018]FIG. 2 is a plan view showing the condition of the card connector in the embodiment of the invention before a card is inserted;  
         [0019]    [0019]FIG. 3 is an enlarged perspective view showing an essential portion of an ejection mechanism of the card connector in the embodiment of the present invention as seen from the back;  
         [0020]    [0020]FIG. 4 is a perspective view showing a locking piece used in the card connector of the present invention;  
         [0021]    [0021]FIG. 5 is a side cross-sectional view showing the condition of the card connector in the embodiment of the present invention before the card is inserted;  
         [0022]    [0022]FIG. 6 is a side view showing the condition of the card connector in the embodiment of the present invention before the card is inserted;  
         [0023]    [0023]FIG. 7 is a plan view and a side view showing the condition of the card connector in the embodiment of the present invention when the card Is inserted;  
         [0024]    [0024]FIG. 8 is a horizontal cross-sectional view schematically showing the condition of the card connector in the embodiment of the present invention when the card is inserted;  
         [0025]    [0025]FIG. 9 is a side view showing the card connector in the embodiment of the present invention when an ejection button is pressed;  
         [0026]    [0026]FIG. 10 is a partly enlarged side view showing the condition of the card connector in the embodiment of the present invention when the ejection button is pressed;  
         [0027]    [0027]FIG. 11 is a side cross-sectional view showing the card connector in the embodiment of the present invention when an ejection button is pressed;  
         [0028]    [0028]FIG. 12 is a horizontal cross-sectional view schematically showing the card connector in the embodiment of the present invention when the ejection button is pressed; and  
         [0029]    [0029]FIG. 13 is a plan view schematically showing a prior art. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0030]    Now, embodiments of the present invention will be described in detail by referring to the accompanying drawings.  
         [0031]    [0031]FIG. 1 is a perspective view showing an external construction of the card connector. FIG. 2 is a plan view showing the construction of the card connector, with a cover  30  of an ejection portion (FIG. 1) taken away, before the card is inserted.  
         [0032]    The card connector  1  is installed in electronic devices such as cellular phones, PDAs, portable audio devices and cameras.  
         [0033]    An IC card  10  (hereinafter referred to also as a card  10 ), as shown in FIG. 3, FIG. 7 and FIG. 12, has a chamfer  12  at one front end corner of its body portion  11  for preventing an erroneous insertion of the card. On the back surface of the body portion  11  there are arranged a plurality of metal contact pads  13  connected to an IC in the card.  
         [0034]    In FIG. 1 and FIG. 2, the card connector  1  has a connector housing  20  molded from an insulating material such as resin. When the connector housing  20  needs a lid, it may be formed integral with the lid or provided with a separate lid.  
         [0035]    The IC card  10  is inserted into the connector  1  through a card insertion opening  21  formed in the front of the connector housing  20 . The connector housing  20  has a card accommodating portion defined by a pair of side wall portions  22 ,  23 , a bottom plate portion  24  and a rear plate portion  25 .  
         [0036]    At the bottom plate portion  24  is formed a plurality of grooves  45  for positioning and fixing a plurality of contact terminals  40 ,  
         [0037]    The each of contact terminals  40  include power supply terminals and signal terminals. Each of the contact terminals  40  in this embodiment is folded over and has a terminal portion  40   a  soldered to a corresponding contact pad on a printed circuit board of the electronic device, a fixed portion  40   b  securely press-fitted in the groove  45 , and a contact leaf spring portion  40   c  elastically displaced to come into contact with the contact pad  13  of the card  10 . The contact leaf spring portion  40   c  has a prominent contact portion  40   d.    
         [0038]    Contact terminals  40  of these plurality make electrical connection between the card  10  and the electronic device, and the elastic force of the contact leaf spring portion  40   c  holds the card  10  with an appropriate force when it is loaded.  
         [0039]    The bottom plate portion  24  is provided with an elastic braking piece  46  for preventing the card from slipping off when the card is ejected.  
         [0040]    Next, a card ejection mechanism, an essential part of the present invention, will be described.  
         [0041]    This card ejection mechanism has an ejection member  50 , a coil spring  55 , an elastic locking piece  60 , an ejection button  70 , and a plate cam lever  80 .  
         [0042]    [0042]FIG. 3 is a view showing an essential portion of the ejection mechanism as seen from the back of the connector. FIG. 4 is a view illustrating the elastic locking piece  60 . FIG. 5 and FIG. 6 are views illustrating the state of the ejection mechanism when the card is not loaded. FIG. 7 and FIG. 8 are views illustrating the state of the ejection mechanism when the card is loaded. FIGS.  9  to  12  are views illustrating the state of the ejection mechanism when the ejection button is pressed.  
         [0043]    As shown in FIGS.  1  to  12 , the ejection member  50  is nearly L-shaped and is slidable in a predetermined range of stroke both in card insertion and ejection directions. As shown in FIG. 2, the ejection member  50  is fixed to one end of the coil spring  55  as an elastic member. The other end of the coil spring  55  is secured to a spring catching projection  28  (FIG. 2) formed on the bottom plate portion  24  of the connector housing  20 . Hence, the ejection member  50  is urged in the card ejection direction by the coil spring  55 .  
         [0044]    The ejection member  50  has a card abutment portion  53  against which the front face of the card  10  abuts and a corner wall  54  which the chamfer  12  of the card  10  touches. When a card is inserted, the ejection member  50  is slid in the card insertion direction by the pushing force of the card  10 . A portion  56  projected to the direction of the back in the ejection member  50  (FIG. 3) is accommodated in a recessed portion  29  (FIG. 1) formed in the rear plate portion  25  of the connector housing  20  when the card is inserted.  
         [0045]    On the bottom side of the ejection member  50  is formed a fixing projection  57  for attaching the elastic locking piece  60  as shown in FIG. 3. The locking projection  57  has a taper portion  57   a  on its rear side with respect to the housing and a fixing portion  57   b  on its front side.  
         [0046]    The elastic locking piece  60 , as shown in FIG. 4, has a fixed portion  60   a  press-fitted in the connector housing  20 , an elastically displaceable spring portion  60   b , and a front expanded portion  60   c . The elastic locking piece  60  is supported like a cantilever. The elastic locking piece  60  is elastically displaced vertically with respect to the connector housing  20  (in a direction of thickness of the loaded card  10 ). The side projecting portions  60   d  (hereinafter referred to as locking portion) at the one side of the front expanded portion  60   c  is engaged the fixing portion  57   b  of the fixing projection  57  of the ejection member  50 . The other side projecting portion  60   e  (hereinafter referred to as a cam touching portion) of the front expanded portion  60   c  comes in contact with a cam surface  81  formed in the plate cam lever  80  and moves almost along the cam surface  81 .  
         [0047]    The ejection button  70  is attached to the connector housing  20  so that it can be slid in the card insertion and ejection directions by a distance equal to the stroke of the eject operation. The ejection button  70  is urged at all times by a built-in spring (not shown) toward the front of the connector  1  (in the card insertion and ejection direction).  
         [0048]    The ejection button  70  has the plate cam lever  80  secured thereto. The plate cam lever  80  is made from a continuous plate material and is slid in the card insertion and ejection directions by a distance of the operation stroke of the ejection button  70  along a groove (not shown) formed in a side edge portion of the connector housing  20 . At the plate cam lever  80  is formed a slot has the cam surface  81  with which the cam touch portion  60   e  of the elastic looking piece  60  is made to come to contact. The movement of the cam surface  81  causes the front expanded portion  60   c  of the elastic locking piece  60  to move vertically with respect to the housing. The cam surface  81  comprises two surfaces with different heights (a locking surface  81   a  and a releasing surface  85   b ) and a taper surface  81   c  connecting these two surfaces.  
         [0049]    Next, the operation of the card connector  1  performed when the card is inserted and ejected will be described.  
         [0050]    (operation When Card is Inserted)  
         [0051]    Before a card is inserted, the ejection member  50  is situated at a predetermined front position spaced from the rear plate portion  25  by the urging force of the coil spring  55 , as shown in FIG. 2 and FIG. 5. At this time, the fixing projection  57  of the ejection member  50  is situated in front side of and spaced from the elastic locking piece  60 , as shown in FIG. 5.  
         [0052]    The ejection button  70  is also situated at a front side position, i.e., on a card insertion slot side, by the elastic force of the built-in spring, so that the plate cam lever  80  is situated in the condition as shown in FIG. 6. That is, the locking surface  81   a  of the plate cam lever  80  opposes the cam touch portion  60   e  of the elastic locking piece  60  and thus the elastic locking piece  60  is not elastically displaced.  
         [0053]    When in this state the card  10  is inserted into the connector  1 , the front end wall and the chamfer  12  of the card  10  press against the card abutment portion  53  and the corner wall  54  of the ejection member  50 . The ejection member  50  is therefore slid toward the rear plate portion  25  (on the rear side of the connector) against the force of the coil spring  55 .  
         [0054]    As the ejection member  50  is moved toward the rear plate portion  25  (in the rearward direction), the locking projection  57  of the ejection member  50  slides from the taper portion  57   a  to the locking portion  60   d  of the elastic looking piece  60 , so that the locking portion  60   d  of the elastic locking piece  60  rides over the fixing projection  57 . The locking portion  60   d , after riding over the fixing projection  57 , is attached by the fixing portion  57   b  of the fixing projection  57 , as shown in FIG. 8. As a result, the ejection member  50  is blocked from moving in the card ejection direction.  
         [0055]    During the process of inserting the card  10 , because the plate cam lever  80  does not move relative to the connector housing  20 , the positional relation between the plate cam lever  80  and the elastic locking piece  60  shown in FIG. 6 is maintained.  
         [0056]    In this way, the card  10  is loaded into the connector  1 .  
         [0057]    (Operation When Card Is Ejected)  
         [0058]    When, with the card  10  loaded, the ejection button  70  is pressed, the plate cam lever  80  is also slid toward the back of the connector in connection with this. The plate cam lever  80  moves relative to the cam touch portion  60   e  of the elastic locking piece  60  so that the cam touch portion  60   e  successively opposes the locking surface  81   a , the taper surface  81   c  and the releasing surface  81   b  in that order until finally the releasing surface  81   b  of the cam surface  81  comes in contact with the cam touch portion  60   e  of the elastic locking piece  60 . As a result, the front expanded portion  60   c  of the elastic locking piece  60  is elastically deflected downwardly of the housing, as shown in FIG. 9 to FIG. 12.  
         [0059]    Hence, as shown in FIG. 10 and FIG. 11, the lock state between the locking portion  60   d  of the elastic locking piece  60  and the fixing projection  57  of the ejection member  50  is canceled. The ejection member  50  is therefore moved toward the card insertion opening side (front side) of the connector housing  20  by the recovering force of the coil spring  55 , ejecting the card  10 . The ejection button  70 , when released from the pressing operation, is automatically returned to the original position by the recovering force of the built-in spring.  
         [0060]    In this way, with this card connector construction, the fixing projection  57  formed on the ejection member  50  and the plate cam lever  80  linked with the ejection button  70  cause the elastic locking piece  60  for locking the ejection member  50  to displace vertically of the connector housing  20  (in the direction of thickness of the card  10 ) so as to lock and release the ejection member  50 . This makes it possible to reduce the width of the connector housing  20  and therefore the mounting area of the connector housing.  
         [0061]    Although in the embodiment described above, the ejection member  50  is provided with the fixing projection  57  which the front end of the elastic locking piece  60  is attached, locking the ejection member  50 , the locking structure is arbitrary, and any other arbitrary locking structure may be adopted. For example, a hook portion may be provided to the front end of the locking piece  60  and a recessed portion  2  for engagement with the hook portion may be formed on the ejection member  50  side.  
         [0062]    Further, while in the embodiment above the ejection operation is done by the ejection button  70 , it is possible to eliminate the ejection button  70  and eject the card by performing a push-push operation on the card  10 . In this push-push type ejector as shown in Japanese Patent Application Laid-open No 2000-251025, the loaded card is pushed slightly toward the rear plate portion  25  (back side of the connector) to unlock the ejection member and thereby eject the card. In this type of ejector, too, the mounting area of the connector can be reduced by displacing the locking piece for the ejection member vertically of the connector housing.  
         [0063]    Further, in the embodiment as described, the coil spring  55  and the spring built into the ejection button  70  are not limited to coil springs but may use any other kind of spring or even an arbitrary elastic body.  
         [0064]    The present invention has been described in detail with respect to preferred embodiments, and it will now be apparent from the foregoing to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and it is the intention, therefore, in the appended claims to cover all such changes and modifications as fall within the true spirit of the invention.