Abstract:
The present disclosure relates to a card socket for an electronic device and, more particularly, to a card socket for an electronic device having an improved card insertion confirmation structure, wherein the structure of a card insertion confirmation terminal, which senses full insertion of a card or a tray into a card socket, is changed so as to improve stability of insertion of the card or the tray.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a national phase of International Application No. PCT/KR2015/010946, filed Oct. 16, 2015, which claims priority to Korean Application No. 10-2014-0140997, filed Oct. 17, 2014 and Korean Application No. 10-2015-0043507, filed Mar. 27, 2015, all of which are incorporated herein by reference in their entireties. 
     
    
     TECHNICAL FIELD 
       [0002]    This disclosure relates to a card socket for use in electronic devices, and more specifically to a card socket for use in electronic devices that can ensure reliable conductive performance by removing oxide films or impurities, etc. by forming a friction zone in the inter-terminal contact part, and can improve the stability of card or tray insertion through a change in the structure of the card insertion confirmation terminal that determines whether the card or tray has been fully inserted into the card socket. 
       BACKGROUND ART 
       [0003]    Various cards (memory cards/SIM cards) storing the personal information, etc., of diverse subscribers, such as their telephone number, are used in electronic devices such as mobile phones. Forms of card insertion include inserting the card alone, and inserting the card mounted on a separate tray. 
         [0004]    In these types of card sockets, a card insertion confirmation terminal is furnished that senses when the card or tray has been fully inserted. Generally, the card insertion confirmation terminal consists of a detect terminal that is contacted to the front end of the card tray when the card tray is inserted, and switch terminal that is pushed backward and contacts the detect terminal when the card tray has been fully inserted. 
         [0005]    A card insertion recognition terminal structure having this configuration is disclosed in Republic of Korea Registered Patent No. 1228837 (hereinafter “Prior Art Reference 1”) and U.S. Pat. No. 7,865,210 (hereinafter “Prior Art Reference 2”). 
         [0006]    The prior art references are generally configured so that upon card/tray insertion, the detect terminal is pushed backward and then contacted to the switch terminal. The detect terminal has internal elasticity such that when the card/tray is withdrawn, after it has been pushed backward upon card/tray insertion, it returns to its original state. 
         [0007]    Likewise, in the case of the prior art references, because the detect terminal has internal elasticity that pushes backward when the card/tray is inserted, force is continuously applied to the card/tray by the detect terminal in the withdrawal direction. Thus, there is a risk of an external nonconformity between the card tray and set, due to the card/tray protruding outward. 
         [0008]    In addition, there is a problem that grounding defects occur due to the penetration of impurities, etc., or the formation of an oxide film between the detect terminal and the contact part of the switch terminal, leading to unreliable conductivity. 
         [0009]    Patent Reference 1: Republic of Korea Registered Patent Gazette No. 1228837 (issued 2013 Feb. 15). 
         [0010]    Patent Reference 2: U.S. Pat. No. 7,865,210 (granted 2011 Jan. 4). 
       SUMMARY 
       [0011]    The purpose of this disclosure, which has been devised in order to address the above-described problems of the prior art, is to provide a card socket for use in electronic devices that can enhance card/tray insertion stability. 
         [0012]    In addition, another purpose of this disclosure relates to a card socket for electronic device use that can remove oxide films or impurities by forming a friction zone on the inter-terminal contact part of the socket. 
         [0013]    The card socket for electronic device use according to Preferred Embodiment 1 of this disclosure comprises: a fixing part that comprises a detect terminal furnished in the insertion space of the housing and is pushed downward by a card/tray when the card/tray is inserted and a switch terminal that is furnished below the detect terminal in the housing so that it contacts the detect terminal, wherein the detect terminal is fixed to the housing; and a pushing portion that is connected to the fixing part and located within the insertion space of the housing and contacts the card/tray so as to be pushed downward while contacting the switch terminal; formed such that either the part of the pushing portion that contacts the card/tray is connected to the fixing part and is located below the part that moves in a cantilevered fashion, or the of the part that contacts the card/tray is equal to or less than the thickness of the floor of the housing. 
         [0014]    In addition, said detect terminal may comprise: a 1st housing fixation part that is the portion that is fixed to the rear end of said housing; a 1st contact part that has internal elasticity and is installed height extending toward either side in the rear part of the insertion space of said housing, having a first end connected to the 1st housing fixation part while a second end contacts the switch terminal, so as to make up the pushing portion; and a push guide part that is formed sloping downward at the front, at a location spaced apart from the second end of said 1st contact part, so that the inserted card/tray slides along the sloped surface and is guided to as to push the 1st contact part, making up the pushing portion. 
         [0015]    In addition, when the card/tray pushes on said 1st contact part while sliding along said push guide part, the 1st contact part is pushed downward in an oblique direction as it approaches the second end. 
         [0016]    In addition, the 1st contact part may comprise a connecting surface that is connected to the 1st housing fixation part; a downward-sloping surface that is bent sloping downward from the connecting surface; and an upward-sloping surface bent upward from the downward-sloping surface. 
         [0017]    In addition, the switch terminal may comprise: a 2nd housing fixation part that is fixed to the housing; and a 2nd contact part that is bent upward from the 2nd housing fixation part. 
         [0018]    In addition, on the bottom surface of the insertion space of the housing, a catch lip is formed that will prevent the top of the second end of the 1st contact part from slipping when the card/tray is mis-inserted, so that a fixed interval is maintained between the 1st contact part and 2nd contact part. 
         [0019]    In addition, because if the end of said push guide part is pushed to a position below the bottom surface of the housing, there is a risk of contacting the PCB so that the PCB is damaged, in order to prevent this, the position of the push guide part that is contacted to the card/tray is below the fixing point, i.e. the part of the 1st contact part that is connected to the 1st housing fixation part, which is moved in a cantilever fashion; or alternatively, the push guide part is formed so as to have a height that is less than the thickness of the base surface of the housing. 
         [0020]    The card socket for electronic device use according to Preferred Embodiment 2 of this disclosure may comprise: a detect terminal that is installed inside the insertion space of the housing and is pushed downward by the card/tray when the card/tray is inserted into the insertion space; and a switch terminal that is installed on the top of the detect terminal the insertion space of the housing, so that contact with the detect terminal is released as the detect terminal is pushed downward. 
         [0021]    In addition, on said detect terminal, at the end of the pushing portion that is pushed by said card/tray, a 1st contact part is formed sloping upward toward the rear, and on said switch terminal, a 2nd contact part is formed that is formed sloping downward toward the front and is contacted to the 1st contact part; and wherein a friction zone is formed between the 1st contact part and 2nd contact part when said detect terminal is pushed downward, so that impurities or oxide films formed on the 1st contact part and 2nd contact part may be removed. 
         [0022]    In addition, when said detect terminal is pushed downward, the friction potential with said switch terminal, caused by the slope zone movement between said 1st contact part and said 2nd contact part, may be greater than the pushing potential of said detect terminal, due to the movement of the 1st contact part along the sloped surface of the 2nd contact part. 
         [0023]    In addition, the upward slope angle of the 1st contact part may be formed greater than the downward slope angle of the 2nd contact part, so that the corner of the 1st contact part rubs against the sloped surface of the 2nd contact part. 
         [0024]    In addition, the upward slope angle of the 1st contact part may be formed smaller than the downward slope angle of the 2nd contact part, so that the corner of the 2nd contact part rubs against the sloped surface of the 1st contact part. 
         [0025]    The following effects may be expected from the card socket for use in electronic devices according to this disclosure. 
         [0026]    First, because in this disclosure the detect terminal is configured so as to contact the switch terminal upon being pushed downward by the card/tray when the card/tray is inserted, a force acts in the thickness direction, i.e. the direction in which the card/tray is lifted upward by the detect terminal and switch terminal each having elasticity. Accordingly, since the card/tray is not subject to a force in the withdrawal direction, there is no risk of an exterior nonconformity between the card/tray and the set, and because the method of push-in insertion heightens the frictional force with the metal shell covering the housing, an enhanced insertion stability is achieved. 
         [0027]    Second, in this disclosure, stability of contact with the detect terminal and switch terminal may be maintained even if the thickness of the card/tray is increased, because the 1st contact part may be readily pushed by the push guide part that makes up the detect terminal, and the contact area with the switch terminal may be increased relative to existing detect terminals while forming the part of the 1st contact part that contacts the switch terminal at a location that is further toward the end than the part that contacts the switch terminal. 
         [0028]    Third, in this disclosure, because the 1st contact part of the detect terminal is kept in a horizontal state while maintaining a fixed interval with the 2nd contact part of the switch terminal, by virtue of the catch lip formed on the housing, the occurrence of shorts between the detect terminal and switch terminal may be greatly curtailed. 
         [0029]    Fourth, in this disclosure, because the detect terminal and card terminal are located below the card/tray when the card/tray is inserted, the size of the overall card socket may be reduced relative to a card socket of the prior art wherein the detect terminal and switch terminal are located in front of the card/tray. 
         [0030]    Fifth, in this disclosure, the occurrence of grounding defects may be prevented by ensuring reliable conductivity, such that even if conductivity defects are present due to impurities or oxide films between the contact parts of the detect terminal and switch terminal, because the terminal corners are configured to scratch the contact surface due to the formation of a sloped zone on the contact parts of the detect terminal and switch terminal. 
         [0031]    Sixth, this disclosure may improve the stability of conductivity, due to maximizing the area over which friction occurs, because the contact potential with the switch terminal  600  due to movement between the 1st contact part  530  and 2nd contact part  620  is greater than the pressure potential of the detect terminal  500 , because the 1st contact part of the detect terminal moves along the 2nd contact part of the switch terminal when the detect terminal is pushed downward. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]      FIG. 1  is a perspective view showing the card socket for use in electronic devices according to Preferred Embodiment 1 of this disclosure, when a card/tray has been inserted therein. 
           [0033]      FIG. 2  is a perspective view of the detect terminal and switch terminal furnished on the housing. 
           [0034]      FIG. 3  is a perspective view showing the gap between the detect terminal and switch terminal being held constant. 
           [0035]      FIG. 4  shows a perspective view of the detect terminal. 
           [0036]      FIG. 5  shows a perspective view of the switch terminal. 
           [0037]      FIG. 6  shows a view in which, prior to card/tray insertion, the gap between the 1st contact part of the detect terminal and the 2nd contact part of the switch terminal is held constant. 
           [0038]      FIG. 7  shows a view in which, during card/tray insertion, the 1st contact part and the 2nd contact part are brought into contact. 
           [0039]      FIG. 8  is a cross-section showing the proportion between the housing and the detect terminal. 
           [0040]      FIG. 9  shows a perspective view of a different implementation of the detect terminal. 
           [0041]      FIG. 10  is a perspective view showing the card socket for use in electronic devices according to Preferred Embodiment 2 of this disclosure, having a detect terminal and a switch terminal furnished on the housing. 
           [0042]      FIG. 11  is a perspective view of the detect terminal. 
           [0043]      FIG. 12  is a perspective view of the switch terminal. 
           [0044]      FIGS. 13A and 13B  are cross-sections of the state in which contact has been broken between the detect terminal and the switch terminal, due to card/tray insertion. 
           [0045]      FIG. 14  shows a perspective view of a different implementation of the detect terminal. 
           [0046]      FIG. 15  is a cross-section showing the assembled state of the detect terminal for forming a friction zone on the contact parts of the detect terminal and switch terminal. 
           [0047]      FIGS. 16A and 16B  are cross-sections showing the rubbing of the edge of the detect terminal against the sloped surface of the switch terminal when the detect terminal is pushed downward. 
           [0048]      FIGS. 17A and 17B  are cross-sections showing the zone of frictional contact between the detect terminal and switch terminal depending on the slope angle of the contact parts of the detect terminal and switch terminal. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0049]    Hereinbelow, a preferred embodiment of the card socket for electronic device use will be described in detail with reference to the attached drawings. 
         [0050]      FIG. 1  is a perspective view showing the card socket for use in electronic devices according to Preferred Embodiment 1 of this disclosure, when a card/tray has been inserted therein. Note that  FIG. 1  is a top view omitting the metal shell that covers the housing. 
         [0051]    The housing  100  that makes up the card socket has front end into which a card/tray  1  is inserted and an insertion space  110  that is opened toward the top and covered by a metal shell. On the basal surface of the insertion space  110 , a contact terminal  200  is furnished that contacts the card, and at the back part of the insertion space  110 , a detect terminal  300  and switch terminal  400  are furnished as a card insertion confirmation terminal that detects when a card/tray  1  has been inserted into the rear part of the insertion space  110 . 
         [0052]      FIG. 2  is a perspective view of the detect terminal and switch terminal furnished on the housing;  FIG. 3  is a perspective view showing the gap between the detect terminal and switch terminal being held constant;  FIG. 4  shows a perspective view of the detect terminal;  FIG. 5  shows a perspective view of the switch terminal. 
         [0053]    At the back part of the insertion space  110  of the housing  100 , a detect terminal  300  and switch terminal  400  are furnished above and below as a card insertion confirmation terminal that detects when a card/tray  1  has been inserted. 
         [0054]    As the card/tray  1  is inserted into the insertion space  110 , the card/tray  1  pushes the detect terminal  300  downward so as to contact the switch terminal  400 , so that the card/tray  1  is recognized to have been inserted into the insertion space  110 . Accordingly, because the detect terminal  300  and switch terminal  400  are in contact vertically, the card/tray  1  is not affected by any force in the withdrawal direction due to the detect terminal  300 , and thus there is no risk of an exterior nonconformity between the card/tray  1  and set. 
         [0055]    In other words, if the detect terminal  300  and switch terminal  400  are in contact, it may be recognized that the card tray  1  is not inserted or has not been completely inserted, and if the detect terminal  300  and switch terminal  400  are not in contact but are separated, it may be recognized that the card tray  1  has been fully and completely inserted into the insertion space  110 . 
         [0056]    Because the detect terminal  300  has elasticity, it is elastically pushed by the card/tray  1 , and because the switch terminal  400  also has elasticity, it is elastically contacted to the detect terminal  300 . 
         [0057]    The detect terminal  300  comprises a 1st housing fixing part  310 , 1st contact part  320 , and push guide part  330 . 
         [0058]    The 1st housing fixing part  310  may be fixed by insertion into an insertion recess (not shown) formed at the rear end of the housing  100 , but is not limited thereto and may also be formed integrally with the housing  100  by molding. 
         [0059]    The 1st contact part  320  is installed extending to either side in the rear part of the insertion space  110 , and has elasticity; a first end is connected integrally with the 1st housing fixing part  310 , while the second end is contacted to the switch terminal  400 . This 1st contact part  320  comprises a connecting surface  321  that integrally connects with the 1st housing fixing part  310 ; a downward-sloping surface  322  that is bent at a downward slope from the connecting surface  321 ; and an upward-sloping surface  323  that is bent sloping upward from the downward-sloping surface  322 . The end of the upward-sloping surface  323  contacts the switch terminal  400 . 
         [0060]    The push guide part  330  is formed sloping downward at the front in a location set apart from the end of the upward-sloping surface  323 , i.e. at the far end of the 1st contact part  320 , so that it guides the card/tray  1  inserted into the insertion space  110  to push on the 1st contact part  320  as it is slid along the sloped surface. 
         [0061]    The switch terminal  400  comprises a 2nd housing fixing part  410  and a 2nd contact part  420 . 
         [0062]    The 2nd housing fixing part  410  may be formed integrally with the housing  100  by molding. 
         [0063]    The 2nd contact part  420  is bent at an upward slope from the 2nd housing fixing part  410 , so that it has internal elasticity. The end of the 2nd contact part  420  is contacted to the detect terminal  300 . 
         [0064]    On the bottom surface of the insertion space  110 , a 2nd contact part  420  is located, and a through part  120  is formed that passes through in a vertical direction so as to enable vertical elastic deformation. Part of the 2nd housing fixing part  410  that is connected to the 2nd contact part  420  is also located in the through part  120 . 
         [0065]    On the rear surface of the insertion space  110 , a catch lip  130  is formed projecting outward so as to prevent the 1st contact part  320  of the detect terminal  300  from lifting upward when the card/tray  1  is mis-inserted, so that the gap between the 1st contact part  320  and the 2nd contact part  420  of the switch terminal  400  is kept constant. 
         [0066]    Before catching the 1st contact part  320  of the detect terminal  300  on the catch lip  130 , the 1st contact part  320  is formed sloping upward as shown in FIG.&gt;2, and then the 1st contact part  320  is pushed so that when it catches on the catch lip  130  as shown in  FIG. 3 , the 1st contact part  320  maintains a horizontal state and keeps a constant interval with the 2nd contact part  420 . Accordingly, the incidence of shorts between the detect terminal  300  and switch terminal  400  may be greatly reduced. 
         [0067]      FIG. 6  shows a view in which, prior to card/tray insertion, the gap between the 1st contact part of the detect terminal and the 2nd contact part of the switch terminal is held constant;  FIG. 7  shows a view in which, during card/tray insertion, the 1st contact part and the 2nd contact part are brought into contact. 
         [0068]    As described above, while caught on the catch lip  130  of the 1st contact part  320 , the 1st contact part  320  maintains a constant gap with the 2nd contact part  420  while remaining in a horizontal state, as shown in  FIG. 6 . In this case the 2nd contact part  420  slopes upward. 
         [0069]    If the card/tray  1  is inserted so as to push the 1st contact part  320 , then as shown in  FIG. 7 , the 1st contact part  320  is pushed sloping downward, and is also pushed as the end of the 1st contact part  320  and the end of the 2nd contact part  420  contact each other. Finally, when it has been pushed, the 1st contact part  320  is tilted downward and the 2nd contact part  420  is in a horizontal state; the ends of the two contact parts  320   420  are in contact with one another. 
         [0070]    As shown in  FIG. 6 , before the 1st contact part  320  is pushed by the card/tray  1 , the end of the push guide part  330 , formed sloping downward and forward from the 1st contact part  320 , is located at a lower place than the 1st contact part  320 . Accordingly, when the card/tray  1  is inserted, the card/tray  1  indirectly pushes the 1st contact part  320  while sliding along the upper sloped surface of the push guide part  330 , and additionally as it is inserted, it is directly contacted to the upper surface of the 1st contact part  320  while pushing directly on the 1st contact part  320 . 
         [0071]    As the 1st contact part  320  is pushed by the card/tray  1 , it is pushed downward in an oblique direction; thus, the end contact portion does not contact the card/tray  1 . 
         [0072]    Because the part of the 1st contact part  320  that contacts the switch terminal  400  without directly contacting the card/tray  1  is formed further toward the end than the part that directly contacts the card/tray  1 , when the 1st contact part  320  is pushed by the card/tray  1 , the part that contacts the switch terminal  400  moves a great deal more (A+a). Accordingly, even if the distance by which the detect terminal  300  is pushed is relatively reduced due to the thickness of the card/tray  1 , because the contact area with the switch terminal  400  is increased relative to the detect terminals of the prior art, the stability of contact between the 1st contact part  320  and 2nd contact part  420  may be maintained. 
         [0073]      FIG. 8  is a cross-section showing the proportion between the housing and the detect terminal. 
         [0074]    A push guide part  330  that forms the detect terminal  300  is located within the through part  120  formed in the basal surface of the insertion space of the housing  100 . Accordingly, when the detect terminal  300  is pushed by insertion of the card/tray  1 , the part that is pushed, namely the push guide part  330 , is caused to descend within the through part  120 . In this case, because if the end of said push guide part  330  is pushed to a position below the bottom surface of the housing  100 , there is a risk of contacting the PCB so that the PCB is damaged, in order to prevent this, the position of the part that contacts the card/tray  1  is below the fixing point that moves in cantilever fashion, i.e. below the connecting surface  321  of the 1st contact part  320 ; or alternatively, the push guide part  330  may preferably be formed so as to have a height (H 1 ) that is equal to or less than the thickness (H 2 ) of the base surface of the housing  100 . 
         [0075]      FIG. 9  shows a perspective view of a different implementation of the detect terminal. 
         [0076]    The 1st contact part  320  that makes up the detect terminal  300  has a shape that is bent 1 time. In other words, the 1st contact part  320  may consist of a connecting surface  321  that connects integrally with the 1st housing fixing part  310 , and a downward-sloping surface  322  that is bent sloping downward from the connecting surface  321 . 
         [0077]    The shape of the detect terminal  300  may be formed in diverse ways. 
         [0078]      FIG. 10  is a perspective view showing the card socket for use in electronic devices according to Preferred Embodiment 2 of this disclosure, having a detect terminal and a switch terminal furnished on the housing;  FIG. 11  is a perspective view of the detect terminal;  FIG. 12  is a perspective view of the switch terminal. 
         [0079]    As shown in  FIGS. 10 through 12 , the card socket for use in electronic devices according to Preferred Embodiment 2 of this disclosure may be furnished above and below with a switch terminal  500  and detect terminal  600 , which make up a card insertion confirmation terminal that senses when a card/tray  1  has been inserted into the back portion of the insertion space  110  of the housing  100 . 
         [0080]    As the card/tray  1  is inserted into the insertion space  110 , the card/tray  1  pushes the detect terminal  500  downward so as to break contact with the switch terminal  600 , so that the card/tray  1  is recognized to have been inserted into the insertion space  110 . As a result, because the detect terminal  500  and switch terminal  600  are in contact vertically, the card/tray  1  is not affected by any force in the withdrawal direction due to the detect terminal  500 , and thus there is no risk of an exterior nonconformity between the card/tray  1  and set. 
         [0081]    In other words, if the detect terminal  500  and switch terminal  600  are in contact, it may be recognized that the card tray  1  is not inserted or has not been completely inserted, and if the detect terminal  500  and switch terminal  600  are not in contact but are separated, it may be recognized that the card tray  1  has been fully and completely inserted into the insertion space  110 . 
         [0082]    The detect terminal  500  has elasticity so that when the card/tray  1  is inserted into the insertion space  110  of the housing  100 , it is elastically pushed downward by the card/tray  1 . 
         [0083]    The detect terminal  500  may comprise a 1st housing fixing part  510 , leaf spring part  520 , 1st contact part  530 , and push guide part  540 . 
         [0084]    The 1st housing fixing part  510  may be fixed by insertion into an insertion recess (not shown) formed at the rear end of the housing  100 , but is not limited thereto and may also be formed integrally with the housing  100  by molding. 
         [0085]    The leaf spring part  520  is the pushing portion that is pushed by the card/tray  1 ; it is installed extending in either direction in the rear part of the insertion space  110  of the housing  100 , and has internal elasticity. A first end of the leaf spring part  520  is connected integrally with the 1st housing fixing part  510 , while a below-described 1st contact part  530  is formed on the second end and is contacted to the switch terminal  600 . This leaf spring part  520  may comprise a connecting surface  521  that integrally connects with the 1st housing fixing part  510 ; a downward-sloping surface  522  that is bent at a downward slope from the connecting surface  521 ; and an upward-sloping surface  523  that is bent sloping upward from the downward-sloping surface  522 . 
         [0086]    The 1st contact part  530  is formed bending at an upward direction backward on the second end of the leaf spring part ( 520 ), i.e. the end of the upward-sloping surface  523 , so as to contact the 2nd contact part  620  of the below-described switch terminal  600 . 
         [0087]    The push guide part  540  is formed sloping downward at the front in a location set apart from the end of the upward-sloping surface  523  in the direction of the 1st housing fixing part  510 , i.e. at the second end of the leaf spring part  520 , so that it guides the card/tray  1  inserted into the insertion space  110  to push on the leaf spring part  520  as it is slid along the sloped surface. 
         [0088]    The switch terminal  600  is installed on top of the detect terminal  500 ; as the detect terminal  500  is pushed downward by the card/tray  1 , the contact with the detect terminal  500  is broken. 
         [0089]    The switch terminal  600  may comprise a 2nd housing fixing part  610  and a 2nd contact part  620 . 
         [0090]    The 2nd housing fixing part  610  may be formed integrally with the housing  100  by molding, but is not limited thereto and may also be fixed by insertion into an insertion recess (not shown) formed at the rear end of the housing  100 . 
         [0091]    The 2nd contact part  620  is formed bending downward and forward from the 2nd housing fixing part  610 , so as to contact the 1st contact part  530  of the detect terminal  500 . 
         [0092]    On the bottom surface of the insertion space  110 , a 1st contact part  530  and push guide part  540  of the detect terminal  500  are located, and a through part  120  is formed that passes through in a vertical direction so as to enable vertical elastic deformation. In addition, part of the leaf spring part  520  connecting the 1st contact part  530  and push guide part  540  is also located in the through part  120 . 
         [0093]    A push guide part  540  that forms the detect terminal  500  is located within the through part  120  formed in the basal surface of the insertion space  110  of the housing  100 . Accordingly, when the detect terminal  500  is pushed by insertion of the card/tray  1 , the part that is pushed, namely the push guide part  540 , is caused to descend within the through part  120 . In this case, because if the end of said push guide part  540  is pushed to a position below the bottom surface of the housing  100 , there is a risk of contacting the PCB so that the PCB is damaged, in order to prevent this, the position of the part that contacts the card/tray  1  is below the fixing point which moves in a cantilever fashion, i.e. below the connecting surface  521  of the leaf spring part  520 ; or alternatively, the push guide part  540  may preferably be formed so as to have a height that is less than the thickness of the base surface of the housing  100 . 
         [0094]      FIGS. 13A and 13B  are cross-sections of the state in which contact has been broken between the detect terminal and the switch terminal, due to card/tray insertion. 
         [0095]    As shown in  FIG. 13A , if the 1st contact part  530  of the detect terminal  300  and the 2nd contact part  620  of the switch terminal  400 , it is recognized that the card/tray  1  has not been inserted or has not been inserted fully. 
         [0096]    As shown in  FIG. 13B , if the card/tray  1  is inserted into the insertion space  110  of the housing  100 , the detect terminal  500  is pushed and caused to move downward by the card/tray  1 . Specifically, before the leaf spring part  520  of the detect terminal  500  is pushed by the card/tray  1 , the end of the push guide part  540  formed sloping downward and forward from the leaf spring part  520  is located in a lower position than the leaf spring part  520 . Accordingly, when the card/tray  1  is inserted, the card/tray  1  indirectly pushes the leaf spring part  520  while sliding along the upper sloped surface of the push guide part  540 , and additionally as it is inserted, it is directly contacted to the upper surface of the leaf spring part  520  while pushing directly on the leaf spring part  520 . 
         [0097]    As the left spring part  520  of the detect terminal  500  moves downward due to the insertion of the card/tray  1 , the 2nd contact part  620  of the switch terminal  600  and the 1st contact part  530  of the detect terminal  500  break contact. Likewise, if the detect terminal  500  and switch terminal  600  are not in contact with one another, the card/tray  1  is recognized to have been fully and completely inserted into the insertion space  110 . 
         [0098]      FIG. 14  shows a perspective view of a different implementation of the detect terminal. 
         [0099]    As shown in  FIG. 14 , the leaf spring part  520  that makes up the detect terminal  500  may also be configured in a flat cantilever shape. In other words, the leaf spring part  520  may be formed as a flat line without a bending part, but is not limited thereto, and the shape of the detect terminal  500  may be formed in diverse ways. 
         [0100]      FIG. 15  is a cross-section showing the assembled state of the detect terminal for forming a friction zone on the contact parts of the detect terminal and switch terminal;  FIGS. 16A and 16B  are cross-sections showing the rubbing of the edge of the detect terminal against the sloped surface of the switch terminal when the detect terminal is pushed downward. 
         [0101]    As shown in  FIGS. 15, 16A and 16B , when the detect terminal  500  is pushed downward by the card/tray  1 , a friction zone W is formed between the 1st contact part  530  of the detect terminal  500  and the 2nd contact part  620  of the switch terminal  600 , so that even if conductivity defects are present due to impurities or oxide films between the contact parts of the detect terminal  500  and switch terminal  600 , these are removed so that the occurrence of grounding defects may be prevented by ensuring reliable conductivity. 
         [0102]    Specifically, by configuring a sloped zone on the contact part of the detect terminal  500  and switch terminal  600  so that the corner of the terminal scratches the contact surface causing rubbing to occur. In addition, a torsional force must be applied to the detect terminal  500  in the assembly process, in order to establish a friction-causing mechanism. For example, the detect terminal  500  does not generate a torsional force at the pre-assembly location ( 1 ) and a recovering torque of the detect terminal  500  is generated at the post-assembly location ( 2 ). Specifically, an X-direction torque is generated due to the X-direction difference (ΔX) between the initial pre-assembly location and final post-assembly location of the detect terminal  500  in the X direction, and a Z-direction torque is generated due to the Z-direction difference (ΔZ) between the initial pre-assembly location and final post-assembly location of the Z-direction detect terminal  500 ; accordingly, a recovering torque of the detect terminal  500  is generated in the arrow direction (see arrow in  FIG. 15 ). Even if the detect terminal  500  is moved in the direction of the −Z axis by this torque, friction is generated between the contact parts of the detect terminal  500  and the switch terminal  600 , due to the corner  530   a  of the 1st contact part  530  of the detect terminal  500  moving along the sloped surface  620   b  of the 2nd contact part  620  of the switch terminal  600 . 
         [0103]    In addition, the stability of conductivity may be enhanced, due to maximizing the area over which friction occurs, because when the detect terminal  500  moves in the downward direction (−Z), the contact potential with the switch terminal  600  due to movement between the 1st contact part  530  and 2nd contact part  620  is greater than the pressure potential of the detect terminal  500 , because the corner  530   a  of the 1st contact part  530  moves along the sloped surface  620   b  of the 2nd contact part  620  of the switch terminal  600 . 
         [0104]      FIGS. 17A and 17B  are cross-sections showing the zone of frictional contact between the detect terminal and switch terminal depending on the slope angle of the contact parts of the detect terminal and switch terminal. 
         [0105]    As shown in  FIG. 17A , by configuring the upward-sloping angle θ1 of the 1st contact part  530  of the detect terminal  500  to be greater than the downward-sloping angle θ2 of the 2nd contact part  620  of the switch terminal  600 , the corner  530   a  of the 1st contact part  530  of the detect terminal  500  may be caused to rub against the sloped surface  620   b  of the 2nd contact part  620  of the switch terminal  600 . 
         [0106]    In addition, as shown in  FIG. 17B , by configuring the upward-sloping angle θ1 of the 1st contact part  530  of the detect terminal  500  to be less than the downward-sloping angle θ2 of the 2nd contact part  620  of the switch terminal  600 , the corner  620   a  of the 2nd contact part  620  of the switch terminal  600  may be caused to rub against the sloped surface  530   b  of the 1st contact part  530  of the detect terminal  500 . 
         [0107]    Hereinabove, the card socket for use in electronic devices according to this disclosure has been described based on a preferred embodiment, but this disclosure is not limited to any specific embodiment, and a person of ordinary skill in the art of the relevant field will be able to make diverse modifications without departing from the claimed scope of this disclosure.