Abstract:
Disclosed are a set-top box and display apparatus having a discrete-type card portion and card portion-mounting methods thereof, in which the card portion with a card such as a cable card for descrambling a scrambled signal is readily detached and attached from the outside. The set-top box includes: a signal receiver configured to receive a scrambled signal; a card portion configured to include a card slot portion to which a cable card for descrambling the received scrambled signal is mountable; a substrate configured to include the signal receiver and electrically connect with the card portion; and a housing configured to support and surround the substrate, the housing including a first opening formed on a surface parallel with the substrate, and the card slot portion of the card portion being disposed to face the substrate with the first opening of the housing therebetween.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from Korean Patent Application No. 10-2014-0147019, filed on Oct. 28, 2014 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     
    
       [0002]    BACKGROUND 
         [0003]    1. Field 
         [0004]    Apparatuses and methods consistent with the exemplary embodiments relate to a set-top box and display apparatus having a discrete-type card portion, and more particularly to a set-top box and display apparatus having a discrete-type card portion and card portion-mounting methods thereof, in which the card portion with a personal computer memory card international association (PCMCIA) card such as a cable card for descrambling a scrambled signal is readily detached and attached from the outside and thus its maintenance is easy. 
         [0005]    2. Description of the Related Art 
         [0006]    In general, a set-top box (STB) or a display apparatus such as a digital television (TV) having a set-top box function includes a card portion with a PCMCIA card such as a cable card for descrambling a scrambled broadcast signal. 
         [0007]    As shown in  FIG. 1 , a card portion  10  of a set-top box  1  generally has a card mounting portion  15  to which a card  13  such as a cable card is mounted. 
         [0008]    The card mounting portion  15  is provided on a main substrate  7  inside the set-top box  1  so that an inlet opening  11   a  of a card slot  11  can be aligned with a card insertion opening  5   a  of an upper cover  5 . When the card  13  is inserted through the inlet opening  11   a  of the card slot  11 , a pin socket positioned at a front end portion of the card  13  is connected to pin terminals arranged inside the card slot  11 . The main substrate  7  is fastened to a bottom frame  3 , and the bottom frame  3  is covered with the upper cover  5 . 
         [0009]    Therefore, if the card mounting portion  15  needs to be repaired or replaced due to failure or the like, the whole upper cover  5  has to be separated from the bottom frame  3  in order to approach and detach the card mounting portion  15 . 
         [0010]    Further, the area of the main substrate  7  for mounting parts thereon is wasted as much as the area occupied by the card mounting portion  15  since the card mounting portion  15  is installed on the main substrate  7 . In result, the main substrate  7  has to be enlarged as much as the area wasted by the card mounting portion  15  in order to mount the foregoing parts thereon, and thus the size of the set-top box  1  increases. 
         [0011]    In addition, the card  13  is a part that radiates heat by itself, and therefore the main substrate  7  installed with the card mounting portion  15  may need to have a heat dissipating opening  7   a  for dissipating the heat from the card  13 . In this case, man hour for manufacturing the main substrate  7  increases. 
         [0012]    Further, the card  13  is likely to be affected by heat generated by a heat radiating element  9  of the set-top box  1  since the card  13  is placed inside the set-top box  1 . Hence, the card mounting portion  15  may need to have an additional cooling device such as a heat sink  18  or the like with cooling pins for cooling the card  13 . In this case, the product costs of the set-top box  1  increases. 
         [0013]    Accordingly, a new card portion has been required to solve the foregoing problems of the conventional card portion  10 . 
       SUMMARY 
       [0014]    An aspect of exemplary embodiments provides a set-top box and display apparatus having a discrete-type card portion and card portion-mounting methods thereof, in which the card portion with a PCMCIA card such as a cable card for descrambling a scrambled signal is readily detached and attached from the outside and thus its maintenance is easy. 
         [0015]    Another aspect of exemplary embodiments provides a set-top box and display apparatus having a discrete-type card portion and card portion-mounting methods thereof, in which an installation structure for the card portion is improved to increase a usable area of a main substrate and thus decrease the sizes of the substrate and apparatus. 
         [0016]    Still another aspect of exemplary embodiments provides a set-top box and display apparatus having a discrete-type card portion and card portion-mounting methods thereof, in which a cooling structure of the card portion is improved to not only raise a cooling efficiency of the card portion but also reduce product costs. 
         [0017]    In accordance with an exemplary embodiment, there is provided a set-top box including: a signal receiver configured to receive a scrambled signal; a card portion configured to include a card slot portion to which a cable card for descrambling the received scrambled signal is mounted; a substrate configured to include the signal receiver and electrically connect with the card portion; and a housing configured to support and surround the substrate, the housing including a first opening formed on a surface parallel with the substrate, and the card slot portion of the card portion being disposed to face the substrate with the first opening of the housing therebetween. 
         [0018]    In this set-top box, the card portion is exposed to the outside through the first opening, and it is thus easy to approach and detachably mount the card portion from the outside. In result, the maintenance of the card portion becomes easy. 
         [0019]    The card portion may be installed on a first surface of the substrate. Thus, the card portion may be installed on the first surface where the circuit parts are not mounted. In result, the usable area of the substrate increases, and thus the sizes of the substrate and device decreases. 
         [0020]    Alternatively, the card portion may be installed on a second surface of the substrate. Thus, the card portion may be also installed on the second surface of the substrate where the circuit parts are mounted in accordance with design. 
         [0021]    The card portion may include a connection socket mounted with the cable card and electrically connecting with the substrate, the connection socket including: a first socket portion configured to penetrate the first opening and electrically connect with the substrate; a second socket portion configured to includes a first surface electrically connecting with the first socket portion and a second surface electrically connecting with the cable card; and the card slot portion configured to accommodate and support the second socket portion and guide movement of the cable card parallel with the first opening so that the cable card can connect with the second surface of the second socket portion. Thus, it is easy to detach and attach the card portion from the outside. 
         [0022]    The first opening may have a size corresponding to the card slot portion. At this time, the first socket portion may protrude outward by a predetermined distance or more from the housing through the first opening of the housing. Thus, there is provided an air flowing space via which air can flow by convection from between the housing and the card slot portion in at least one directions, for example, a direction of both sides and an inlet direction of the card slot portion through the first opening in the state that the cable card is connected to the second socket portion through the card slot portion. In result, the cooling efficiency of the card portion is improved, and there is no need of adding another cooling device, thereby reducing production costs. 
         [0023]    The connection socket may further include a fastener configured to detachably fasten the card slot portion to one of the substrate and the housing. The fastener may include: a first fastener disposed at a first end portion of the card slot portion; and a second fastener disposed at a second end portion of the card slot portion. Thus, the connection socket can be detachably fastened to the substrate or the housing. 
         [0024]    The first fastener may include at least one first pillar disposed at each first end portion of the card slot portion and fastened to the substrate by a screw, and the second fastener may include at least one second pillar disposed at each second end portion of the card slot portion and including a locking projection locked to the substrate. 
         [0025]    Alternatively, the first fastener may include at least one first pillar disposed at each first end portion of the card slot portion and locked to the substrate, and the second fastener may include at least one second pillar disposed at each second end portion of the card slot portion and including a locking projection locked to the substrate. 
         [0026]    Further, the first fastener may include at least one first fastening bracket disposed at each first end portion of the card slot portion and fixed to the housing, and the second fastener may include at least one second fastening bracket disposed at each second end portion of the card slot portion and fixed to the housing. 
         [0027]    The housing may further include a plurality of second openings for circulating air in the set-top box outward. Thus, heat caused by the cable card and heat caused by circuit parts of the set-top box can be radiated outward. 
         [0028]    The set-top box may further include a blowing fan for circulating air in the set-top box. Thus, heat caused by the cable card and heat caused by circuit parts of the set-top box can be more efficiently radiated outward. 
         [0029]    The housing may include a ground disposed to contact and ground the cable card when the cable card is mounted to the connection socket. The ground includes a contact projection formed on a surface of the housing facing the cable card mounted to the card slot portion of the connection socket. Thus, it is sufficient to reinforce the ground of the card portion. 
         [0030]    The set-top box may further include a sealing cover configured to seal up the connection socket. Thus, it is possible to restrict an approach to the card portion except permission of a content provider. The sealing cover may include a plurality of third openings formed at a position corresponding to the air flowing space where air flow by convection through the first opening. Thus, regardless of installation of the sealing cover, heat generated in the cable card is cooled by air flowing through the third opening and the air flowing space. 
         [0031]    In accordance with another exemplary embodiment, there is provided a method of mounting the card portion of the foregoing display apparatus, which includes a housing supporting and surrounding the substrate, the method including: preparing the housing having a first opening; detachably mounting the card portion to one of the substrate and the housing; and installing the substrate in the housing so that the card slot portion of the card portion can be exposed to an outside through the first opening. 
         [0032]    In this card portion-mounting method for the set-top box, it is easy to approach and detachably mount the card portion from the outside since the card portion is exposed through the first opening. 
         [0033]    In accordance with still another exemplary embodiment, there is provided a display apparatus including: a signal receiver configured to receive a scrambled signal; a card portion configured to include a card slot portion to which a cable card for descrambling the scrambled signal is mounted; a video processor configured to process the descrambled signal to be displayed as an image; a display configured to display a signal processed by the video processor; a substrate configured to include the signal receiver and electrically connect with the card portion; and a housing configured to support and surround the substrate, the housing including a first opening formed on a surface parallel with the substrate, and the card slot portion of the card portion being disposed to face the substrate with the first opening of the housing therebetween. 
         [0034]    In this display apparatus, the card portion is exposed through the first opening, and it is thus easy to approach and detachably mount the card portion from the outside. 
         [0035]    The card portion may be installed on one side of the substrate where circuit parts are mounted. 
         [0036]    The card portion may include a connection socket mounted with the cable card and electrically connecting with the substrate, the connection socket including: a first socket portion configured to penetrate the first opening and electrically connect with the substrate; a second socket portion configured to include a first surface electrically connecting with the first socket portion and a second surface electrically connecting with the cable card; and the card slot portion configured to accommodate and support the second socket portion and guide movement of the cable card parallel with the first opening so that the cable card can connect with the second surface of the second socket portion. Thus, the card portion can be easily attached and detached from the outside. 
         [0037]    The first opening may have a size corresponding to at least a part of the card slot portion. At this time, the first socket portion may protrude outward by a predetermined distance or more from the housing through the first opening of the housing. Thus, there is provided an air flowing space via which air can flow by convection from between the housing and the card slot portion in at least one directions, for example, a direction of both sides and an inlet direction of the card slot portion through the first opening in the state that the cable card is connected to the second socket portion through the card slot portion. In result, the cooling efficiency of the card portion is improved, and there is no need of adding another cooling device. 
         [0038]    The connection socket may further include a fastener configured to detachably fasten the card slot portion to one of the substrate and the housing. The fastener may include: a first fastener disposed at a first end portion of the card slot portion; and a second fastener disposed at a second end portion of the card slot portion. Thus, the connection socket is detachably fastened to the substrate or the housing. 
         [0039]    In accordance with still another exemplary embodiment, there is provided a method of mounting the card portion of the foregoing display apparatus, which includes a housing supporting and surrounding the substrate, the method including: preparing the housing having a first opening; detachably mounting the card portion to one of the substrate and the housing; and installing the substrate in the housing so that the card slot portion of the card portion can be exposed to an outside through the first opening. 
         [0040]    In this card portion-mounting method for the display apparatus, it is easy to approach and detachably mount the card portion from the outside since the card portion is exposed through the first opening. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0041]    The above and/or other aspects will become apparent and more readily appreciated from the following description of exemplary embodiments, taken in conjunction with the accompanying drawings, in which: 
           [0042]      FIG. 1  is a cross-section view illustrating a set-top box having a general card portion; 
           [0043]      FIG. 2  is an exploded perspective view illustrating a set-top box with a discrete-type card portion according to an exemplary embodiment; 
           [0044]      FIG. 3  is a cross-section view taken along line III of  FIG. 2 ; 
           [0045]      FIG. 4  is a block diagram of a set-top box with a discrete-type card portion according to an exemplary embodiment; 
           [0046]      FIG. 5  is a partial perspective view illustrating an air flowing space, in which air can flow by convection through an exposure opening in a state that a cable card is connected to a second socket portion through a card slot portion; 
           [0047]      FIG. 6  is a view showing the card slot portion where the second socket is accommodated, along a direction of VI-VI of  FIG. 3 ; 
           [0048]      FIG. 7  is a view showing the card slot portion where the second socket is accommodated, along a direction of VII-VII of  FIG. 3 ; 
           [0049]      FIG. 8  is a view showing the card slot portion where the second socket is accommodated, along a direction of VIII-VIII of  FIG. 6 ; 
           [0050]      FIG. 9  is a perspective view showing an alternative example to a fastener of a card mounting portion; 
           [0051]      FIG. 10  is a cross-section view showing another alternative example to a fastener of a card mounting portion; 
           [0052]      FIG. 11  is a cross-section view of a set-top box with a discrete-type card portion according to another exemplary embodiment, which includes a sealing member; 
           [0053]      FIG. 12  is a perspective view of the sealing member of  FIG. 11 ; 
           [0054]      FIG. 13  is a cross-section view of a set-top box with a discrete-type card portion according to still another exemplary embodiment, which includes a blowing fan for circulating air; 
           [0055]      FIG. 14  is a cross-section view of a set-top box with a discrete-type card portion according to yet another exemplary embodiment; 
           [0056]      FIG. 15  is a flowchart showing a card portion mounting process in the set-top box according to an exemplary embodiment; 
           [0057]      FIG. 16  is a block diagram of a display apparatus with a discrete-type card portion according to another exemplary embodiment; 
           [0058]      FIG. 17  is a cross-section view of a display apparatus with a discrete-type card portion according to still another exemplary embodiment; and 
           [0059]      FIG. 18  is a flowchart showing a card portion mounting process in the display apparatus with according to yet another exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0060]    Below, a set-top box and display apparatus having a discrete-type card portion, and card portion-mounting methods thereof according to exemplary embodiments will be described in detail with reference to accompanying drawings. 
         [0061]      FIG. 2  and  FIG. 3  are an exploded perspective view and a cross-section view of a set-top box with a discrete-type card portion according to an exemplary embodiment. 
         [0062]    According to this exemplary embodiment, a set-top box  100  is an open cable set-top box, which receives a broadcast signal and broadcast-related information by a wire and wirelessly and transmits the received broadcast signal and broadcast-related information to the display apparatus  300  (see  FIG. 4 ). 
         [0063]    As shown in  FIG. 2  and  FIG. 3 , the set-top box  100  includes a subscriber terminal (Host)  101 , and a card portion  200  with a cable card  210 . 
         [0064]    The subscriber terminal  101  includes a bottom frame  103 , a main substrate  105  and an upper cover  107 . 
         [0065]    The bottom frame  103  and the upper cover  107  form a housing that supports and surrounds the main substrate  105 . 
         [0066]    The bottom frame  103  is a member for supporting the main substrate  105 , and is made of a metallic material and shaped like a top-opened box. On an inner surface of the bottom  103   a  of the bottom frame  103 , first to fourth fixing lugs  104   a  protrude to support the main substrate  105 . The first to fourth fixing lugs  104   a  may be positioned corresponding to four corners of the main substrate  105 , respectively. Further, on an outer surface of the bottom  103   a  of the bottom frame  103 , first to fourth support legs  104   b  are provided to support the set-top box  100  on a floor. 
         [0067]    Further, the bottom frame  103  is formed with the exposure opening  109  on the bottom  103   a  thereof corresponding to a card mounting portion  220  of the card portion  200  to be mounted to a bottom  105   a  of the main substrate  105 , so that the connection socket  230  of the card mounting portion  220  can be installed and at least a part of the card mounting portion  220  is exposed to the outside. The exposure opening  109  may have a size corresponding to at least a part of a card slot portion  240  of the connection socket  230 . Thus, the exposure opening  109  allows the first and second socket portions  231  and  235  of the connection socket  230  and the card slot portion  240  to pass therethrough and be exposed to the outside when the card mounting portion  220  is mounted to the bottom  105   a  of the main substrate  105 . 
         [0068]    Further, the bottom frame  103  is provided with a ground  106  on the outer surface of the bottom  103   a  thereof to ground the cable card  210 . The ground  106  is arranged to contact a top surface of the cable card  210  when the cable card  210  is mounted to the connection socket  230  of the card mounting portion  220 . To this end, the ground  106  may include a plurality of ground projections  108  (one of them is representatively shown in  FIG. 3 ) which protrude at regular intervals corresponding to a card mounting position on the outer surface of the bottom  103   a  of the bottom frame  103 . 
         [0069]    The upper cover  107  is a member for sealing up the main substrate  105  supported by the bottom frame  103 , and is made of a metallic or plastic material and shaped like a bottom-opened box. The upper cover  107  receives and seals four lateral walls of the bottom frame  103 , and is fastened to the bottom frame  103  by a screw or the like (not shown). 
         [0070]    Further, the upper cover  107  is formed with a plurality of first ventilation openings  107   b  on a top surface  107   a  thereof to ventilate the inside of the subscriber terminal  101 . The first ventilation openings  107   b  may be provided in the form of slits. 
         [0071]    The main substrate  105  is installed in the bottom frame  103 , and its bottom is supported at four corners by the first to fourth fixing lugs  104   a  and fastened to the first to fourth fixing lugs  104   a  by first fastening screws  259 . Thus, the main substrate  105  is disposed at a first distance from the inner surface of the bottom  103   a  of the bottom frame  103 . 
         [0072]    The main substrate  105  may be achieved by a printed circuit board (PCB). 
         [0073]    As shown in  FIG. 4 , circuit parts, which constitute a controller  110 , first to third tuners  111 ,  112  and  113 , first to third demodulators  120 ,  150  and  160 , a demultiplexer  130 , a decoder  140 , a switch  170  and a modulator  180 , are mounted to a top surface  105   b  of the main substrate  105 . 
         [0074]    The first to third tuners  111 ,  112  and  113  constitute a signal receiver for receiving a broadcast signal through an antenna and a cable. 
         [0075]    The first tuner  111  is tuned to only a frequency corresponding to a certain channel with regard to terrestrial audio/video (A/V) broadcast signals received through the antenna or cable A/V broadcast signals received by an in-band mode through the cable and outputs the broadcast signal of the tuned channel to a first demodulator  120 . 
         [0076]    At this time, the terrestrial broadcast and the cable broadcast are different in a transmission method, and therefore differently demodulated in the first demodulator  120 . That is, the terrestrial A/V broadcast signal is demodulated by vestigial sideband modulation (VSB), and the cable A/V broadcast signal is demodulated by quadrature amplitude modulation (QAM). Hence, if a channel frequency to which the first tuner  111  is tuned corresponds to the terrestrial broadcast signal, the broadcast signal is demodulated in the first demodulator  120  by the VSB. If the channel frequency corresponds to the cable broadcast signal, it is demodulated by the QAM. 
         [0077]    Further, if a signal demodulated in the first demodulator  120  is the terrestrial broadcast signal, the demodulated signal is output to the demultiplexer  130 . If a signal demodulated in the first demodulator  120  is the cable broadcast signal, the demodulated signal is output to the demultiplexer  130  via the cable card  210  mounted to the card mounting portion  220  of the card portion  200 . 
         [0078]    The demultiplexer  130  separates the multiplexed broadcast signal into a video signal and an audio signal and outputs the video signal and the audio signal to the decoder  140 . The decoder  140  respectively restores compressed A/V signals into original signals through video and audio decoding algorithms, and outputs the restored signals to the display apparatus  300 . At this time, the decoder  140  may download and use the video decoding algorithm and the audio decoding algorithm from a codec server (not shown) through a cable modem (not shown). 
         [0079]    The second tuner  112  is tuned to a frequency corresponding to a certain channel with regard to data broadcast signals received by a DOCSIS set-top gateway (DSG) mode through a cable and outputs the data broadcast signal of the tuned channel to a second demodulator  150 . The second demodulator  150  demodulates the DSG data broadcast signal and outputs it to the controller  110 . 
         [0080]    Further, the third tuner  113  is tuned to a frequency corresponding to a certain channel with regard to data broadcast signals received by an out of band (OOB) mode through the cable and outputs the broadcast signal of the tuned channel to a third demodulator  160 . The third demodulator  160  demodulates the OBB data broadcast signal by quadrature phase shift keying (QPSK) and outputs the data broadcast signal of the tuned channel to the cable card  210  of the card portion  200 . At this time, the reason why the third demodulator  160  demodulates the OOB data broadcast signal by QPSK is because the OOB mode employs the transmission method of QPSK. 
         [0081]    Further, if interactive communication is possible between a cable broadcasting station (not shown) and the subscriber terminal  101 , information (for example, pay program application, status information of the subscriber terminal  101 , a user&#39;s input, etc.) to be transmitted from the subscriber terminal  101  to the cable broadcasting station is transmitted by the OOB or DSG mode. To this end, the switch  170  is provided. Switching control for the switch  170  is fulfilled in the controller  110 . The controller  110  may be achieved by a central processing unit (CPU). 
         [0082]    For instance, in the OOB mode, status information of a user or subscriber terminal  101  is output to the modulator  180  via the cable card  210  and the switch  170 , demodulated in the modulator  180  by the QPSK mode, and transmitted to the cable broadcasting station via the cable. Further, in the DSG mode, status information of a user or subscriber terminal  101  is output to the modulator  180  via the controller  110  and the switch  170 , modulated in the modulator  180  by a  16 -QAM mode, and transmitted to the cable broadcasting station via the cable. 
         [0083]    The card portion  200  is a discrete type card portion, and includes a card mounting portion  220  to which the cable card  210  is mounted. 
         [0084]    The cable card  210  is to descramble a scrambled broadcast signal, and is also called a point of deployment (POD) module. The cable card  210  includes a conditional access (CA) system for copy protection with regard to a high value-added broadcast content and for restricted access. 
         [0085]    Specifically, if the scrambled cable A/V broadcast signal is received, the cable card  210  descrambles the received broadcast signal and outputs it to the demultiplexer  130 . If the cable card  210  is not mounted to the card mounting portion  220 , the cable A/V broadcast signal demodulated by the first demodulator  120  is directly output to the demultiplexer  130 . In this case, the scrambled cable A/V broadcast signal since is not descrambled and thus a user cannot normally view the broadcast signal. 
         [0086]    The cable card  210  may be achieved by a single-stream card for processing only one stream or by a multi-stream card for simultaneously processing a plurality of streams. 
         [0087]    Referring back to  FIG. 2  and  FIG. 3 , the card mounting portion  220  is mounted with the cable card  210  and includes the connection socket  230  electrically connected to the main substrate  105 . 
         [0088]    The connection socket  230  is installed in the bottom  105   a  of the main substrate  105  and exposed to the outside though the exposure opening  109  of the bottom frame  103 . 
         [0089]    The connection socket  230  includes the first and second socket portions  231  and  235 , and the card slot portion  240 . 
         [0090]    The first socket portion  231  has a box shape, and is arranged to electrically connect with the bottom  105   a  of the main substrate  105 . To this end, the first socket portion  231  includes a plurality of, e.g., sixty eight first pin receiving holes  233  to connect with sixty eight substrate pin terminals substrate pin terminals  105   c  formed in the bottom  105   a  of the main substrate  105 . The first pin receiving holes  233  may be formed to penetrate the first socket portion  231 . 
         [0091]    The first socket portion  231  may be formed to have a height to be extended through the exposure opening  109  of the bottom frame  103  and exposed to the outside by a predetermined distance D or more from the bottom  103   a  of the bottom frame  103 . 
         [0092]    This is to provide an air flowing space  119  via which air can flow in arrow directions by convection from between the bottom  103   a  of the bottom frame  103  and an upper side of the card slot portion  240  toward a direction of both sides (i.e. frontward and backward directions in the drawings) and an inlet direction of the card slot portion  240  through the exposure opening  109  of the bottom frame  103  in the state that the cable card  210  is connected to the second socket portion  235  through the card slot portion  240  as shown in  FIG. 3  and  FIG. 5 . Thus, it is possible to more efficiently dissipate heat radiated from the cable card  210 . 
         [0093]    The second socket portion  235  is shaped like a stick, and includes first and second sixty eight pin terminals  236 ,  237  respectively protruding from a top surface  235   a  and a lateral side  235   b  perpendicular to the top surface  235   a.  The first pin terminals  236  are inserted in and electrically connected to the first pin receiving holes  233  of the first socket portion  231 , and the second pin terminals  237  are inserted in and electrically connected to sixty eight second pin receiving holes (not shown) formed on the front end surface of the cable card  210 . 
         [0094]    As shown in  FIG. 2  and  FIG. 6  to  FIG. 8 , the card slot portion  240  is formed with a guide frame  241  having a ‘U’ shape. The guide frame  241  accommodates and supports the second socket portion  235  in a mounting space inside a left end portion of the guide frame  241  (‘left’ refers to in relation to the drawings). The second fastening screws  261  are fixed to the first pillars  252  and  253  of the first fastener  251  (to be described later) via first screen holes  263  formed at opposite end portions of the guide frame  241  and the second screw holes  264  formed at opposite end portions of the second socket portion  235 . In result, the guide frame  241 , the second socket portion  235  and the first pillars  252  and  253  are coupled one another. 
         [0095]    On the right side of the left end portion of the guide frame  241  in which the second socket portion  235  is accommodated and supported, a card insertion slot  245  is formed to guide the insertion of the cable card  210 . The second socket portion  235  is installed so that the first pin terminals  236  of the top surface  235   a  can protrude upward from the left end portion of the guide frame  241  and the second pin terminals  237  of the lateral surface  235   b  can protrude toward the inside of the card insertion slot  245 . 
         [0096]    Therefore, the second socket portion  235  is not only electrically connected to but also coupled to the first socket portion  231  as the first pin terminals  236  of the top surface  235   a  are inserted in the first pin receiving holes  233  of the first socket portion  231 . Further, when the cable card  210  is inserted in the card insertion slot  245 , the second socket portion  235  electrically connects with the cable card  210  as the second pin terminals  237  of the lateral surface  235   b  are inserted in the second pin receiving holes of the cable card  210 . 
         [0097]    The card insertion slot  245  is provided with an elastic supporter  246  for supporting and preventing the cable card  210  from being easily separated from the card insertion slot  245  after the cable card  210  is inserted in the card insertion slot  245 . The elastic supporter  246  includes a plurality of the elastic support projections  247  and first and second lateral support springs  248 . The plurality of the elastic support projections  247  are aligned in a line with the bottom of the slot  245 , and the first and second lateral support springs  248  are respectively formed inside the right end portions of the card insertion slot  245 . Thus, when the cable card  210  is inserted in the card insertion slot  245 , both lateral surfaces and the bottom of the cable card  210  are elastically supported by the elastic supporter  246 , and the cable card  210  is not easily separated from the slot  245 . 
         [0098]    To detachably mount the guide frame  241  of the card slot portion  240 , in which the second socket portion  235  connecting with the first socket portion  231  is accommodated and supported, to the main substrate  105 , the connection socket  230  further includes a fastener  250 . 
         [0099]    As shown in  FIG. 2  and  FIG. 5 , the fastener  250  includes a first fastener  251  and a second fastener  255 . 
         [0100]    The first fasteners  251  are respectively disposed on the opposite end portions of the second socket portion  235  and include a pair of first pillars  252  and  253  fastened to the opposite end portions of the second socket portion  235  by the second fastening screws  261 . The pair of first pillars  252  and  253  is fastened to the bottom  105   a  of the main substrate  105  by a third fastening screw  265 . The third fastening screw  265  is fastened to the first pillars  252  and  253  via through holes  105   c  of the main substrate  105 . Thus, the left end portion of the card mounting portion  220 , i.e. the left end portion of the guide frame  241 , in which the second socket portion  235  connecting with the first socket portion  231  is accommodated and supported, is detachably mounted to the main substrate  105 . 
         [0101]    The second fastener  255  includes a pair of second pillars  256  and  257  respectively disposed at the right end portions of the guide frame  241 . The second pillars  256  and  257  include locking projections  256   a  and  257   a  to be locked to locking grooves  105   d  of the main substrate  105 , respectively. Thus, the right end portion of the card mounting portion  220 , i.e. the right end portion of the guide frame  241  is detachably mounted to the main substrate  105 . 
         [0102]    Alternatively, as shown in  FIG. 9 , like the second fastener  255 , a first fastener  251 ′ of a fastener  250 ′ may include a pair of first pillars  252 ′ and  253 ′ having locking projections  252   a  and  253   a  to be locked to the locking grooves (not shown) of the main substrate  105 . 
         [0103]    Further, as shown in  FIG. 10 , to detachably mount the guide frame  241  of the card slot portion  240  to the bottom frame  103 , a fastener  250 ″ may include a first fastener  251 ″ having a pair of first fastening brackets  251   a  respectively protruding from both sides of the left end portion of the guide frame  241 , and a second fastener  255 ′ having a pair of second fastening brackets  255   a  respectively protruding from both sides of the right end portion of the guide frame  241 . The first and second fastening brackets  251   a  and  255   a  may be fastened to the bottom  103   a  of the bottom frame  103  by screws. 
         [0104]    Thus, when the first socket portion  231 , the second socket portion  235 , the card slot portion  240  or the like needs to be repaired or replaced due to damage in the first and second pin terminals  236  and  237  of the second socket portion  235 , a connection defect between the first socket portion  231  and the pin receiving holes of the cable card  210 , etc., the connection socket  230  can be repaired and replaced by easily separating the first socket portion  231 , the second socket portion  235 , the card slot portion  240  or the like from the bottom  103   a  of the bottom frame  103  through the fastener  250  from the outside. 
         [0105]    Alternatively, as shown in  FIG. 11 , to restrict an approach (or access) to the cable card  210  except permission of a content provider, the subscriber terminal  101  may further include a sealing cover  280  for sealing up the card portion  200 . The sealing cover  280  is shaped like a box surrounding the card portion  200 , and fastened to the bottom frame  103  by screws. Further, as shown in  FIG. 12 , the sealing cover  280  may include a plurality of air flowing openings  119   a  formed at positions corresponding to the air flowing space  119  so as to assist air convection in the air flowing space  119 . 
         [0106]    Further, as shown in  FIG. 13 , to promote air flow in the air flowing space  119  and easily dissipate heat radiating from the cable card  210 , the subscriber terminal  101  may further include a blowing fan  290  for blowing air. 
         [0107]    The blowing fan  290  is installed near a blowing opening  290   a  formed on one lateral wall of the upper cover  107 , thereby discharging air in the subscriber terminal  101  to the outside or introducing external air into the subscriber terminal  101  in accordance with rotating directions. According to an exemplary embodiment, it will be assumed that the blowing fan  290  operates to discharge air in the subscriber terminal  101  to the outside. 
         [0108]    At this time, a plurality of ventilation openings  107   b ′ of the upper cover  107  are formed on a lateral wall opposite to the lateral wall of the upper cover  107  where the blowing fan  290  is installed. 
         [0109]    When the blowing fan  290  operates, the external air is introduced into the subscriber terminal  101  via the ventilation openings  107   b ′ and the air flowing space  119 , so that both heat caused by circuit parts of the subscriber terminal  101  and heat caused by the cable card  210  can be radiated toward the outside of the subscriber terminal  101  through the blowing openings  290   a.    
         [0110]    In the foregoing set-top box  100  according to an exemplary embodiment, the card portion  200  is installed on the bottom  105   a  of the main substrate  105 , but not limited thereto. For example, in a set-top box  100 ′ as shown in  FIG. 14 , a card mounting portion  220 ′ of a card portion  220 ′ may be installed on a top surface  105   b  of the main substrate  105  where circuit parts are installed. In this case, an exposure opening  109 ′ for exposing the connection socket  230  of a card mounting portion  220 ′ is formed on not the bottom frame  103 ′ but a top surface  107   a  of an upper cover  107 ′. Thus, the set-top boxes  100  and  100 ′ are improved in degrees of freedom on designing in light of installing the card portions  220  and  220 ′. 
         [0111]    A method of mounting the card portion  200  of the foregoing set-top box  100  according to an exemplary embodiment will be described below in detail with reference to  FIG. 15 . 
         [0112]    First, the bottom frame  103  formed with the exposure opening  109  on the bottom  103   a  thereof for exposing the connection socket  230  of the card mounting portion  220  is prepared (S 10 ). 
         [0113]    Then, the card portion  200  is detachably mounted to the bottom of the main substrate  105  (S 20 ). That is, the second socket portion  235  is disposed at the mounting space in the left end portion of the guide frame  241 , and the first pin terminals  236  of the top surface  235   a  of the second socket portion  235  are inserted in and connected to the first pin receiving holes  233  of the first socket portion  231 . Further, the first pillars  252  and  253  of the first fastener  251  are fastened to the opposite end portions of the second socket portion  235  and the opposite sides of the left end portion of the guide frame  241  by the second fastening screws  261 . In result, the first socket portion  231 , the second socket portion  235  and the guide frame  241  are assembled into the connection socket  230 . The connection socket  230  is electrically connected to the main substrate  105  as not only the right end portions of the guide frame  241  are locked to the locking grooves  105   d  of the main substrate  105  by the locking projections  256   a  and  257   a  of the second pillars  256  and  257  but also substrate projection terminals  117  protruding from the bottom  105   a  of the main substrate  105  are inserted in substrate accommodating holes  232  of the first socket portion  231 . Then, the first pillars  252  and  253  of the first fastener  251  are fastened to the main substrate  105  by the third fastening screw  265 , thereby mounting the connection socket  230  to the main substrate  105 . 
         [0114]    Alternatively, as shown in  FIG. 10 , the card portion  200  may be provided so that the connection socket  230  can be detachably mounted to the bottom frame  103  by a fastener  250 ″. In this case, the connection between the substrate projection terminals  117  protruding from the bottom  105   a  of the main substrate  105  and the substrate accommodating holes  232  of the first socket portion  231  may be achieved when the main substrate  105  is installed inside the bottom frame  103 . 
         [0115]    Like this, the main substrate  105  mounted with the connection socket  230  is installed inside the bottom frame  103  and then fastened to the first to fourth fixing lugs  104  by the first fastening screws  259  so that the connection socket  230  of the card mounting portion  220  can be exposed to the outside through the exposure opening  109  of the bottom frame  103  (S 30 ). At this time, the first socket portion  231  protrudes outward by a predetermined distance D or more from the bottom  103   a  of the bottom frame  103  through the exposure opening  109  of the bottom frame  103 . Thus, there is provided the air flowing space  119  via which air can flow by convection from between the bottom  103   a  of the bottom frame  103  and an upper side of the card slot portion  240  toward the direction of both sides of the guide frame  241  and an inlet direction through the exposure opening  109  of the bottom frame  103  in the state that the cable card  210  is inserted in the card insertion slot  245  of the guide frame  241  and connected to the second socket portion  235 . 
         [0116]    Next, when the first socket portion  231 , the second socket portion  235 , the card slot portion  240  or the like needs to be repaired or replaced due to a connection defect or the like, the connection socket  230  can be detached as follows. 
         [0117]    First, from the outside of the bottom  103   a  of the bottom frame  103 , the second fastening screws  261  are removed through the exposure opening  109 . 
         [0118]    Then, the locking projections  256   a  and  257   a  of the first pillars  256  and  257  locked to the locking groove  105   d  of the main substrate  105  are released, thereby removing the guide frame  241 . At this time, the second socket portion  235  accommodated in and supported by the guide frame  241  and the first socket portion  231  connected to the second socket portion  235  may be removed together with or separately from the guide frame  241 . 
         [0119]    Then, the first socket portion  231  and/or the second socket portion  235  causing the connection defect is repaired or replaced. Next, the first socket portion  231 , the second socket portion  235 , and the guide frame  241  are coupled as described above and assembled into the connection socket  230 . Such an assembled connection socket  230  is coupled and mounted to the main substrate  105  like that of the mounting process. 
         [0120]    Consequently, the first socket portion  231 , the second socket portion  235 , the guide frame  241  and the like are easily separated and repaired or replaced using the fastener  250  from the outside of the bottom  103   a  of the bottom frame  103  without opening the upper cover  107 . 
         [0121]      FIG. 16  and  FIG. 17  are a cross-section view and a block diagram showing a display apparatus with a card portion according to another exemplary embodiment. 
         [0122]    A display apparatus  100 ″ according to an exemplary embodiment is a device for providing an open cable set-top box function, and may for example include a digital TV, a PC, a notebook PC, and the like device capable of displaying an image. Below, a digital TV will be described as an example of the display apparatus  100 ″. 
         [0123]    As shown in  FIG. 16  and  FIG. 17 , the display apparatus  100 ″ is a digital TV with an open cable set-top box function, and includes a set-top box  101 ′, a video processor  310 , a display  320 , a wireless communicator  330 , an audio processor  340 , a storage  350 , an user input  360 , and an main controller  370 . 
         [0124]    The set-top box  101 ′ is the same as the set-top box  100  described in  FIG. 2  to  FIG. 10  except that a card mounting portion  220 ″ of a card portion  200 ″ is installed on the top surface  105   a  that faces an inner surface of a rear cover  107 ″ (see the bottom in the drawings) of the set-top box substrate  105 ′ where circuit parts are installed and exposed to the outside through an exposure opening  109 ″ of the rear cover  107 ″, and the bottom frame  103 ″ is installed on the rear (see the bottom in the drawings) of the display panel of the display  320 . 
         [0125]    Further, the rear cover  107 ″ and the bottom frame  103 ″ form a housing that supports the set-top box substrate  105 ′ and a display apparatus substrate  305  and surrounds the set-top box substrate  105 ′ and the display apparatus substrate  305 . 
         [0126]    As necessary, the set-top box  101 ′ may selectively include the sealing cover  280  and/or the blowing fan  290  described with reference to  FIG. 11  to  FIG. 13 . 
         [0127]    On the top surface of the display apparatus substrate  305 , circuit parts that constitute a video processor  310 , a wireless communicator  330 , an audio processor  340 , a storage  350 , a user input  360 , a main controller  370 , etc. are installed. 
         [0128]    The video processor  310  processes a video signal output from the decoder  140  to be displayed as an image. The video processor  310  may have image enhancing, scaling and the like function. 
         [0129]    The display  320  displays an image based on the video signal processed by the video processor  310 . The display  320  may include a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting diode (OLED), or the like display panel (not shown) for displaying an image, and a panel driver (not shown) for fulfill timing control so that the video signal can be displayed on the display panel. 
         [0130]    The wireless communicator  330  communicates with other devices such as a mobile device or the like. The wireless communicator  330  may be achieved by a module for short-range wireless communication, i.e. at least one of modules such as wireless fidelity (Wi-Fi), Bluetooth, infrared data association (IrDA), Zigbee, wireless local areal network (WLAN), and ultra-wideband (UWB). 
         [0131]    The audio processor  340  processes an audio signal output from the decoder  140  and outputs it to a loudspeaker SPK. 
         [0132]    The storage  350  stores a content (e.g., broadcast channel, video on demand (VOD), etc.) displayed on the display  320 , and/or a firmware or control program for controlling the display apparatus  100 ″. The storage  350  may be achieved by a flash memory, a hard disk, or the like nonvolatile memory. 
         [0133]    The user input  360  receives a user&#39;s command. The user input  360  may include a remote controller (not shown), and a remote control signal receiver that receives a remote control signal including key input information corresponding to a user&#39;s input from the remote controller. 
         [0134]    The main controller  370  generally controls the operations of the display apparatus  100 ″. The main controller  370  may be achieved by a CPU. Further, the main controller  370  may further include a DDR or the like volatile memory for loading at least a part of stored operation system so that the CPU can have a rapid access. 
         [0135]    A method of mounting the card portion  200 ″ of the foregoing display apparatus  100 ″ according to another exemplary embodiment will be described below in detail with reference to  FIG. 18 . 
         [0136]    First, the rear cover  107 ″ with the exposure opening  109 ″ for exposing the connection socket  230  of the card mounting portion  220 ″ to the outside is prepared (S 10 ′). 
         [0137]    Then, the card portion  200 ″ is detachably mounted to the top surface  105   b  of the set-top box substrate  105 ′ (S 20 ). The operation of mounting the card portion  200 ″ to the top surface  105   b  of the set-top box substrate  105 ′ is the same as the foregoing operation of mounting the card portion  200  described with reference to  FIG. 15  except that the card portion  200 ″ is mounted to not the bottom  105   a  of the set-top box substrate  105 ′ but the top surface  105   b  mounted with circuit parts. 
         [0138]    Further, alternatively, in the card portion  200 ″, the connection socket  230  may be detachably installed to the rear cover  107 ″ by a fastener  250 ″ as shown in  FIG. 10 . In this case, the connection between substrate projection terminals protruding from the top surface  105   b  of the set-top box substrate  105 ′ and substrate accommodating holes of the first socket portion  231  may be fulfilled when the rear cover  107 ″ is coupled to the bottom frame  103 ″ in the operation S 30 ′. 
         [0139]    Then, the set-top box substrate  105 ′ mounted with the connection socket  230  is installed in the bottom frame  103 ″ and fastened to the first to fourth fixing lugs  104   a  by the first fastening screws, and the rear cover  107 ″ is coupled to the bottom frame  103 ″ so that the connection socket  230  of the card mounting portion  220 ″ can be exposed to the outside through the exposure opening  109 ″ (S 30 ′). At this time, the first socket portion  231  protrudes outward by a predetermined distance D or more from a rear surface  107   a  of the rear cover  107 ″ through the exposure opening  109 ″ of the rear cover  107 ″. Thus, there is provided the air flowing space  119 ″ via which air can flow by convection from between the rear surface  107   a  of the rear cover  107 ″ and the guide frame  241  toward the opposite directions and an inlet direction of the upper guide frame  241  through the exposure opening  109 ″ of the rear cover  107  in the state that the cable card  210  is inserted in the card insertion slot of the guide frame  241  and connected to the second socket portion  235 . 
         [0140]    Then, the display panel of the display  320  is installed in a front space of the rear cover  107 ″ so that the rear surface can contact the bottom frame  103 ″. 
         [0141]    Operations of replacing the first socket portion  231 , the second socket portion  235 , the card slot portion  240  or the like due to a connection defect and the like are the same as the repairing or replacing operations for the card portion  200  described with reference to  FIG. 15 . Thus, repetitive descriptions will be avoided. 
         [0142]    As described above, there are provided a set-top box  100 ,  100 ′ and display apparatus  100 ″ having a discrete-type card portion  200 ,  200 ″ and card portion-mounting methods thereof, in which the card portion  200 ,  200 ″ is readily detached and attached from the outside since it is exposed to the outside through the exposure opening  109 ,  109 ′,  109 ″. In result, the maintenance and replacement of the card portion  200 ,  200 ″ are easy. 
         [0143]    Further, the card portion  200  of the set-top box  100  can be installed on the bottom  105   a  of the main substrate  105 , where circuit parts are not mounted, by forming the exposure opening  109  on the bottom frame  103 . In result, the usable area of the main substrate  105  increases, and thus the sizes of the main substrate  105  and set-top box  100  are decreased. 
         [0144]    Further, the first socket portion  231  can protrude outward by a predetermined distance or more from the bottom frame  103 , the upper covers  107 ,  107 ′ or the rear cover  107 ″ through the exposure opening  109 ,  109 ′,  109 ″ of the bottom frame  103 , the upper covers  107 ,  107 ′ or the rear cover  107 ″. Thus, there is provided the air flowing space  119 ,  119 ″ via which air can flow by convection from between the guide frame  241  and the bottom frame  103 , the upper covers  107 ,  107 ′ or the rear cover  107 ″ in at least some directions, for example, the opposite directions and inlet direction of the guide frame  241  in the state that the cable card  210  is connected to the second socket portion  235  through the guide frame  241 . In result, a cooling efficiency for the card portion  200 ,  200 ″ is improved, and thus there is no need of adding another cooling device, thereby reducing product costs. 
         [0145]    Although a few exemplary embodiments have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these exemplary embodiments without departing from the principles and spirit of the invention. Therefore, the foregoing has to be considered as illustrative only. The scope of the invention is defined in the appended claims and their equivalents. Accordingly, all suitable modification and equivalents may fall within the scope of the invention.