Abstract:
A common socket device for memory cards is a common inserted base with an upper cover to offer a common space for receive a smart media card, a multimedia card, and a secure digital memory card. The common base may be inserted by two or three memory cards without a need of providing two or three kinds of different socket device. Therefore, contact points in the common socket device is reduced substantially, a less volume of the common socket device is obtained comparing to the gross volume of two or three conventional socket devices, and it enhance the convenience for the user.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a common socket device for memory cards, and particularly to a socket device, which is possible for being inserted by a smart media card, a multimedia card, and a secure digital memory card respectively. 
     2. Description of Related Art 
     Usually, a portable personal apparatus such as a digital camera, or a notebook computer is provided with a memory card for storing data. It is necessary to arrange a socket device to receive the memory card of the portable personal apparatus. The socket device has connecting pins therein to contact with the memory card and a microprocessor in the portable personal apparatus. Although a smart media card, a multimedia card, and a secure digital memory card basically are all memory cards, shapes of these cards and numbers of contact points on these cards are different from one another. Hence, socket devices adaptable for different types of memory cards are different from one another in their shapes and connecting pins in number therein either. It means a specific type of socket device can only for a kind of memory card not for all kinds of memory cards. However, it is inconvenient that two or three different socket devices have to be offered in case of two or three different memory cards being used. In this way, a lot of contact points in circuits used in all utilized socket devices are needed and a large gross volume of all utilized socket devices is required either. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a common socket device for memory cards, which is adaptable for different types of memory cards to enhance the convenience while in use. 
     Another object of the present invention is to provide a common socket device for memory cards, which is less in contact points therein and is smaller in volume than the conventional ones having the same function. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention can be more fully understood by referring to the following description and accompanying drawing, in which: 
     FIGS. 1A,  1 B, and  1 C are plan views of smart media card, Multimedia card, and security digital memory card illustrating outer looks thereof with thickness; 
     FIG. 2 is a perspective view of common socket device for memory cards according to the present invention in a first embodiment thereof; 
     FIG. 3 is a disassembled perspective view of the common socket device for memory cards shown in FIGS. 1A,  1 B, and  1 C illustrating a base and a cover thereof; 
     FIG. 4 is a disassembled perspective view similar to FIG. 3 illustrating a base and a cover in a second embodiment of the present invention; 
     FIG. 5 is perspective view of a base in a third embodiment of the present invention; 
     FIG. 6 is a perspective view of a base in a fourth embodiment of the present invention; 
     FIG. 7 is a perspective view of outer look of a fifth embodiment according to the present invention; 
     FIG. 8 is a perspective view of outer look of a sixth embodiment according to the present invention; 
     FIG. 9 is a perspective view of outer look of a seventh embodiment according to the present invention; 
     FIG. 10 is a disassembled perspective view of the common socket device for memory cards shown in FIG. 9 illustrating a base and a cover thereof; 
     FIG. 11 is a disassembled perspective view similar to FIG. 10 illustrating a base and a cover in a eighth embodiment of the present invention; 
     FIG. 12 is a perspective view of a base in a ninth embodiment of the present invention; 
     FIG. 13 is a perspective view of outer look of a tenth embodiment according to the present invention; 
     FIG. 14 is a sectional view of a spring leg used in the present invention; 
     FIG. 15 is a circuit diagram illustrating a circuit arranged in the present invention; and 
     FIG. 16 is another circuit diagram illustrating another circuit arranged in the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1A,  1 B, and  1 C, the smart media card  10  is bigger and thinner, the multimedia card  20  is smaller and thicker, and the security digital memory card  30  is the same size as the multimedia card  20  but thicker. These three memory cards are attached with exposed contact pieces  101 ,  201 , and  301  on a facial side thereof respectively and contact pieces  101 ,  201 , and  301  are different in number. These contact pieces are ports for memories in these memory cards to connect with outward. The width of each contact piece  101  and the clearance between any two neighboring contact pieces  101  on the smart media card  10  are about the same as that of each contact piece  201  and that between any two adjacent contact pieces  201  on the multimedia card  20  respectively. The clearance between adjacent contact pieces  301  on the security digital memory card  30  is the same as that between adjacent contact pieces  201  on the multimedia card  20 . A respective chamfer  102 ,  202 ,  302  is provided on these three memory cards, and the security digital memory card  30  is arranged a write protection switch  303  additionally. 
     Referring to FIGS. 2 and 3, a first embodiment of the present invention provides a common socket device  40 , which comprises a base  41 , and an upper cover  42 . The common socket device  40  at the interior thereof is arranged a first receiving slot  43 , which is wider and thinner for locating the security digital memory card, a second receiving slot  44 , which is narrower and thicker for locating the multimedia card. A common section  431  is disposed between the first receiving slot  43  and the second receiving slot  44 . The base  41  at both lateral sides thereof has a sensor switch  410  respectively, and long connecting pins  46  and short connecting pins  47  are arranged to have an equal space apart one another alternately between these two sensor switches  410 . Each long connecting pin  46  and each short connecting pin  47  at an end thereof extend outward from a rear side  411  of the base  41  for connecting with a circuit on a circuit board. Each long connecting pin  46  and each short connecting pin  47  are elastically bent upward respectively to pressingly contact with two rows of the contact pieces  101  on the smart media card. When the smart media card is inserted into the common socket device  40 , a corner opposite to the corner with chamfer  102  on the smart media card presses against one of sensor switches  410 . The base  41  at both lateral sides  412  thereof is provided with a projecting piece  413  and at the front end thereof has a recession opening  48  for an inserted memory card being taken out easily. The upper cover  42  has a projection section  421  with a shape corresponding to the multimedia card and a sensor switch  45  is provided at a lateral side thereof to detect if the multimedia card is in the socket device  40  or not. The front end of the upper cover  42  also has a recession opening  48  either. An engaging aperture  423  is provided at both lateral walls  422  of the upper cover  42  respectively such that the respective projecting piece  413  may engage with the respective engaging aperture  423  firmly and extends outward while the upper cover  42  is joined to the base  41 . The sensor switch  45  on the upper cover  42  comprises a first spring strip  451  and a second spring strip  452  and both the spring strips contact with each other at an end thereof. The first spring strip  451  has projection part  453  extends outward from a lateral side of the projection section  421  on the upper cover  421 . When the multimedia card is inserted into the projection section  421  to press against the projection part  453  on the first spring strip  451 , the projection part  453  may move inward to make the first spring strip  451  disconnect the second spring strip  452 . Each contact piece on the multimedia card contacts with a long connecting pin  46 . 
     Referring to FIG. 4, a second embodiment of the present invention provides connecting pins  49  in the projection section  421  on the upper cover  42  and these connecting pins  49  at an end thereof pressingly contact with contact pieces on the multimedia card. The other ends of these connecting pins  49  extend outward from the top of the upper to connect with the circuit on a circuit board. Contact pieces on the multimedia card do not contact with long connecting pins  46  at the base  41  in the second embodiment. A sensor switch  410  is provided at both lateral sides of the base  41  respectively only in the second embodiment. 
     Referring to FIG. 5, a third embodiment of the present invention provides an expanded second receiving slot toward a lateral side of the base  41 . In this way, a second contact piece next to the first contact piece  201  on the multimedia card can contact with a long connecting pin  46  close to this lateral side to leave the first contact piece  201  not being contacted. The contact piece  201  is a reserved one and it can be kept not in use. 
     Referring to FIG. 6, a fourth embodiment of the present invention provides seven of long connecting pins on the base  41  and these seven connecting pins are a little shorter than rest of long connecting pins about 0.3-0.4 mm. In this way, the multimedia card and the secure digital memory card have their rear parts extend outward from the rear end of the common socket device a length equal to each other. These seven shortened long connecting pins may contact with contact pieces on the smart media card and the multimedia card respectively. Referring to FIG. 7, the projection section  421  on the upper cover  42  may extend backward to have the second receiving slot extends to the rear part of the common socket device. In this way, the contact pieces on the multimedia card may be pressingly contacted by short connecting pins on the base. Referring to FIG. 8, the projection section  421  may be arranged at the middle area of the upper cover  42 . 
     Referring to FIGS. 9 and 10, a seventh embodiment of the present invention is a common socket device  50  for three cards. The common socket device  50  has a primary difference from the common socket device  40  for two cards shown in FIGS. 2 and 3. The difference is that the base  51  thereof is provided with a lower recession part  511  to match with the projection section  421  on the upper cover  52  so as to form a space for receiving the secure digital memory card. In order to adapt with two contact pieces closer to each other near lateral sides of the secure digital memory card respectively, long connecting pins  512  and short connecting pins  513  on the base  51  are rearranged. Therefore, these two contact pieces near lateral sides of the secure digital memory card are contacted by long connecting pins  512 . In addition, a sensor switch  514  is provided on the base  51  to detect if the write protection switch in the secure digital memory card is in a state of on. The sensor switch  514  may extend outward from a lateral side of the lower recession part  511 . Because the lower recession part  511  has a width smaller than the projection section  521 , the multimedia card may be placed in a space formed by the projection section  521  without falling in the lower recession  511 . 
     Referring to FIG. 11, an eighth embodiment of the present invention provides a common socket device for three cards different from the second embodiment shown in FIG.  2 . The difference is that a swollen part  522  is formed on the projection section  521  of upper cover  52  for receiving the secure digital memory card, and two more connecting pins  523  are added. In addition, a sensor switch  524  is provided to detect the write protection switch. The sensor switch  524  may extend outward from a lateral side of the projection section  521 . 
     Referring to FIG. 12, a ninth embodiment of the present invention provides a common socket device for three cards, which is different from the fourth embodiment shown in FIG.  6 . The difference is that a lower recession part  511  is arranged on the base  51  for receiving the secure digital memory card and two contact pieces closer to each other at lateral sides of the secure digital memory card match with long connecting pins  512 . In addition, a sensor switch  514  for detecting the write protection switch and a reversed connecting pin  515  are provided in the ninth embodiment. 
     Referring to FIG. 13, a tenth embodiment of the present invention provides a common socket device  50  for three cards. Contact pieces on the multimedia card and the secure digital memory card can contact with short connecting pins in the common socket device  50  because a longer lower recession  511  and a longer projection section  521  are arranged on the common socket device  50 . It is noted that connecting pins in the area possibly reached by the secure digital memory card have to be movable vertically and extendable longitudinally so as not to bias the secure digital memory card being inserted into the common socket device  50  of the present embodiment. 
     It is necessary to arrange a conductive part such as connecting pins disclosed in preceding described embodiments to match the location of contact pieces on the memory card. Referring to FIG. 14, another embodiment of conductive part is illustrated. A hole  701  is set up in the base  70  corresponding to the position of contact pieces on the smart media card, the multimedia card, and the secure digital memory card respectively. The circuit board  80  is provided with a extendable connecting head  81  corresponding to the hole  701 . The extendable connecting head  81  may touch contact pieces on the smart media card, the multimedia card, and the secure digital memory card such that the circuit on circuit board  80  may connect with these memory cards respectively. The extendable connecting head  81  is received in a fixing seat  82  attached to the circuit board  80  and pressed outward by a spring  83  in the fixing seat  82 . The extendable connecting head  81  may move backward in the fixing seat  82  against the biasing force of the spring. 
     Referring to FIG. 15, the structure of circuit adapted with the common socket device of the present invention is illustrated. The circuit comprises a microprocessor  60  connecting joining points  454  on three sensor switches, an interface connector  61  for data of the smart media card, an interface connector  62  for data of multimedia card/secure digital memory card. The interface connector  61  and the interface connector  62  connect a switch  611 ,  621  respectively. These two switches  611 ,  621  connect with each other at the other end thereof and then connect with a joining point on the common socket device so as to connect with long connecting pins and short connecting pins respectively. Once the smart media card, the multimedia card, and the secure digital memory card are inserted into the common socket device, the microprocessor  60  may sense reaction signals from these three sensor switches. Then, the microprocessor  60  may determine to control the switch  611  via the interface connector  61  or the switch  621  via the interface connector  62 . Therefore, connect connecting pins in the common socket device may connect with the smart media card, the multimedia card, and the secure digital memory card. 
     Referring to FIG. 16, another embodiment for the structure of circuit is illustrated. The circuit comprises a microprocessor  60 , an interface connector  61  for data of smart media card, an interface connector  62  for data of multimedia card/secure digital memory card, and joining points  454  for sensor switches on the base. The interface connectors  61 ,  62  connect with the joining point  401  of the common socket device respectively so as to connect with connecting pins on the base and the upper cover. Once the smart media card is inserted into the common socket device, the microprocessor  60  may sense the reaction signals of these sensor switches to identify the smart media card or read directly if it is necessary to insert the multimedia card/secure digital memory card. Then, the microprocessor  60  further determines to read and write data in the smart media card via the interface connector  61  or data in the multimedia card/secure digital memory card via the interface connector  62 . 
     It can be understood that it is required 37 contact points totally while an independent socket device is used for the smart media card, the multimedia card, and the secure digital memory card respectively. It is appreciated that the common socket device for the smart media card, the multimedia card, and the secure digital memory card according to the present invention can reduce to 27 contact points at most to achieve a purpose of saving contact points. Furthermore, the present invention provides a common receiving space for the smart media card, the multimedia card, and the secure digital memory card to save the gross volume required by these three socket devices corresponding to the smart media card, the multimedia card, and the secure digital memory card. Accordingly, it is convenient for a usr and economical for saving the production cost of two extra socket device due to the common socket device of the present invention being adaptable for connecting the smart media card, the multimedia card, or the secure digital memory card respectively. 
     While the invention has been described with reference to a preferred embodiment thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention, which is defined by the appended claims.