Abstract:
Disclosed is a mobile terminal including a terminal body; a display portion movably mounted on the terminal body; and a keyboard portion provided to be slidable on the bottom of the terminal body and selectively exposing an auxiliary keypad. Also, disclosed is a mobile terminal including a body portion; a display portion mounted on the body portion and having a display; a keyboard portion provided on the body portion to be situated therein or slid to be opened to the outside of the body portion; an auxiliary keypad provided on the keyboard portion; and an operating unit attached to the terminal body and enabling the keyboard portion to be opened via an operation button, but, when the display portion is opened, locking the closed keyboard portion even in the case the operation button is pressed. Due to the auxiliary keypad, it is possible to improve the effectiveness in creating a text message and make a game more interesting. Also, in the case the auxiliary keypad is not used to make a call, a locking function is also provided to prevent opening of the keypad to the outside, thereby not interfering with the call.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority under 35 U.S.C. §119(a) from Republic of Korea Patent Application No. 10-2005-0073051, filed on Aug. 10, 2005 in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entity.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a mobile terminal, and more particularly, to a mobile terminal in which an auxiliary keypad is provided to improve the effectiveness in creating a text message and making a game more interesting. In the case the auxiliary keypad is not used, such as when making a call, a locking function is also provided to conceal the keypad from the outside, thereby not interfering with the call.  
         [0004]     2. Description of the Related Art  
         [0005]     Generally, a mobile terminal is a type of communication equipment that a user can conveniently carry and make a call to another person from different places. The mobile terminal is a concept which includes a PDA (Personal Digital Assistant), a cellular phone, a PCS (Personal Communication Service) phone, a Hand-Held PC, a CDMA-2000 (Code Division Multiple Access 1×, 3×) phone, a WCDMA (Wideband CDMA) phone, a Dual Band/Dual Mode phone, a GSM (Global Standard for Mobile) phone, an MBS (Mobile Broadband System) phone, a notebook computer, and the like.  
         [0006]     Since the main characteristic of a mobile terminal is to enable a user to carry the mobile terminal along with the user, a small-sized mobile terminal is preferred. Also, a mobile terminal having a special design or various functions is preferred by a significant number of users. Accordingly, mobile phones which are currently being released are products having functions to enable a user to listen to music, enjoy a movie, create and send a text message, play a game, not to mention the original function of making a call.  
         [0007]     Mobile terminal as above can be generally classified as a flip method, a folder method, and a sliding method. The flip method means a method of generally providing a display portion like an LCD (Liquid Crystal Display) and a key input portion on the same body and uses a cover connected to the lower portion via a hinge which protects the key input portion when closed, or is used to receive or make a call when opened. Also, the folder method is a method of connecting two pieces of folder parts via a hinge to be opened and closed, and providing a main display portion and a key input portion on the two facing surfaces. Finally, the sliding method means a method of two overlapping pieces of sliding parts and providing a display portion and a key input portion on each sliding part facing the same direction. Generally, the sliding method can expose the display portion or the key input portion, which is concealed by the top portion, by sliding the top sliding part.  
         [0008]     The mobile terminal of each method as described above includes button-type keys through which letters and numbers can be inputted and navigation keys on the key input portion. The mobile terminal of the sliding method having the general key input portion as above is illustrated in  FIG. 1 . As illustrated in  FIG. 1 , the mobile terminal includes a body portion  20  including a camera apparatus  10 , a display portion  30  provided with a display  35  and slidably attached to the body portion  20 , and a key input portion  40  for inputting letters and numbers.  
         [0009]     The key input portion  40  includes input keys  41 , navigation keys  42 , and function keys  43 . The input keys  41  are provided on the body portion  20  and in the shape of a button to enable a user to input a number and a letter. The navigation keys  42  are provided in a radial direction to enable the user to selectively press a key, and the function keys  43  are provided around the navigation keys  42 . The input keys  41  are constructed such that the user may select and input letters by pressing one key several times when the user creates a text message. For example, in case of creating a text message in English, if each of the 26 alphabet letters is allocated one key, 26 buttons are needed. However, because of a limited installation space, a plurality of letters is allocated to one button and thereby, a user is able to select and input all alphabet letters only with about 12 input keys  41 . Generally, the user has to select a letter by pressing one key several times. Thus, there is a problem that creating a text message is inconvenient and takes time.  
         [0010]     Namely, until now a user has had to input a number of numbers or letters with the limited number of input keys in the mobile terminal. Thus, a plurality of alphabet letters or Hangul consonants and vowels, or numbers is allocated to one input key. As a matter of fact, while the user uses the mobile terminal, a letter for the English alphabet, Korean alphabet, Chinese alphabet or some other language&#39;s alphabet, or a number is selected in accordance with an input key, and the number of times that input key is pressed. Thus, it has been very inconvenient for the user to use the mobile terminal constructed as above.  
         [0011]     Also, while the functions of mobile terminals are being diversified and users playing a game via the mobile terminals are also increasing, it is hard to say that the input keys  41  sufficiently play their role as input buttons for a game. To play a game, direction keys capable of moving an avatar in all directions or a plurality of operation keys capable of performing special operations are needed as input buttons. However, there is a problem that the space of a mobile terminal is insufficient to provide all those buttons.  
         [0012]     In addition to the input keys  41 , the navigation keys  42  are provided. However, all input buttons desired by a user may not be provided because the installation space is small. If input buttons desired by the user are all provided by increasing the number of buttons, the area of one button becomes too small. Thus, the user may feel inconvenience in operating the buttons and also may have difficulty in finding the proper button because of special keys for a game, or when the user wants to make a call or create a text message. Furthermore, if too many buttons are provided, it is aesthetically wanting. Also, there is a problem that the size of the mobile terminal may become cumbersome. Thus, it is not a preferable solution.  
       SUMMARY OF THE INVENTION  
       [0013]     The present invention is conceived to solve the problems as described above. Thus, the present invention provides a mobile terminal which can improve the effectiveness in creating a text message and make a game more interesting by providing an auxiliary keypad for the SMS message or the game.  
         [0014]     The present invention also provides a mobile terminal in which an auxiliary keypad is not used such as when making a call, and a locking function is also provided to not open the keypad to the outside, thereby not interfering with the call.  
         [0015]     The present invention also provides a mobile terminal with a convenient keypad having a compact external appearance because an auxiliary keypad can be closed.  
         [0016]     To achieve the above objectives of the present invention, according to an aspect of the present invention, a mobile terminal includes a terminal body, a display portion movably mounted on the terminal body; and a keyboard portion provided to be slidable on the bottom of the terminal body and selectively exposing an auxiliary keypad. The keyboard portion may be constructed in plural, and the auxiliary keypad may be variously formed to be an English, Chinese or Korean keyboard to create a text message, or directional keys or operational keys for a game. The present invention is not limited to a cell phone formed with the sliding method, however, and may be constructed to include a body portion and a display portion slidably provided on the body portion and displaying visual information. Also, the display portion may be constructed to slide in the lengthwise direction of the body portion or to horizontally slide in the widthwise direction of the body portion.  
         [0017]     Also, the keyboard portion may be constructed to be automatically opened by using an operation button. Thus, an operating unit including the operation button includes a moving guide attached to the keyboard portion to be movable in accordance with the pushing of the operation button; a guide groove concavely formed on the rear of the terminal body to guide the moving guide; and an elastic body connected to the moving guide to move the same by an elastic force.  
         [0018]     Also, according to another aspect of the present invention, a mobile terminal includes a body portion; a display portion mounted on the body portion and having a display; a keyboard portion provided on the body portion to be closed therein or slid to be opened to the outside of the body portion; an auxiliary keypad provided on the keyboard portion; and an operating unit attached to the terminal body and enabling the keyboard portion to be opened via an operation button, but, when the display portion is opened, locking the keyboard portion in the closed position even in the case the operation button is pressed.  
         [0019]     The operating unit includes an operation button disposed on one side of the terminal body to enable a user to press; a moving guide attached to the keyboard portion to be movable in accordance with the pushing of the operation button; a guide groove concavely formed on the rear of the terminal body to guide the moving guide; an elastic body connected to the moving guide to move the same by an elastic force; a rotating block capable of rotating and protruded on the lower part of the terminal body; and a combination block protruded on the lower part of the display portion and rotating the rotating block in the case the display portion is open and maintaining a certain interval with the rotating block in the case the display portion is folded closed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]     The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:  
         [0021]      FIG. 1  is a front view illustrating a mobile terminal provided with a general key input portion;  
         [0022]      FIG. 2  is a perspective view illustrating the rear of a mobile terminal according to a first embodiment of the present invention;  
         [0023]      FIG. 3  is a perspective view illustrating the state where a display portion of the mobile terminal according to the first embodiment is opened;  
         [0024]      FIG. 4  is a perspective view illustrating the state where first and second keyboard portions of the mobile terminal according to the first embodiment of the present invention are opened;  
         [0025]      FIG. 5  is an exploded perspective view of the mobile terminal according to the first embodiment of the present invention;  
         [0026]      FIG. 6  is a cross-sectional view of the mobile terminal according to the first embodiment;  
         [0027]      FIG. 7  is a cross-sectional view illustrating an operating unit of a mobile terminal according to a second embodiment of the present invention;  
         [0028]      FIG. 8  is a perspective view of a mobile terminal according to a third embodiment of the present invention;  
         [0029]      FIG. 9  is a perspective view illustrating another modified example of the third embodiment;  
         [0030]      FIG. 10  is an exploded perspective view according to a fourth embodiment of the present invention;  
         [0031]      FIG. 11  is an exploded perspective view of an operating unit according to the fourth embodiment of the present invention;  
         [0032]      FIG. 12  is a perspective view illustrating the appearance of the operating unit in the case a display portion according to the fourth embodiment of the present invention is closed;  
         [0033]      FIG. 13  is a cross-sectional view illustrating along A-A′ line of  FIG. 12 ;  
         [0034]      FIG. 14  is a perspective view illustrating the operating unit when the display portion according to the fourth embodiment of the present invention is opened; and  
         [0035]      FIG. 15  is a cross-sectional view illustrating along B-B′ line of  FIG. 14 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0036]     Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited thereto or restricted thereby. Also, a slide-type mobile phone is described in the present invention for convenience of description, but the present invention is not limited thereto and applicable to a folder-type mobile phone.  
       Embodiment 1  
       [0037]      FIG. 2  is a perspective view illustrating the rear of a mobile terminal according to a first embodiment of the present invention,  FIG. 3  is a perspective view illustrating the state where a display portion of the mobile terminal according to the first embodiment is opened, and  FIG. 4  is a perspective view illustrating the state where first and second keyboard portions of the mobile terminal according to the first embodiment of the present invention are opened.  
         [0038]     As illustrated in the figures, the mobile terminal of the present invention includes a terminal body  100 , a keyboard portion  200 , and an auxiliary keypad  300 .  
         [0039]     The terminal body  100  includes a body portion  110  embedded with a communicable circuit member and a display portion  120  provided to be slidable up and down. The body portion  110  is provided with a plurality of input keys  111  in the shape of a button to enable a user to input a number and a letter. A microphone  112  capable of receiving an audio signal is provided on one side of the body portion  110 . Also, although not illustrated in the figures, a battery supplying power is provided. An operation button  410  capable of opening a first keyboard portion  210  from the keyboard portion  200  is provided on the side of the body portion  110 . Another operation button capable of opening a second keyboard portion  220  may be provided on the opposite side to operation button  410 . A display  121  displaying visual information is provided on the display portion  120 , a speaker  123  outputting audio information is provided on the upper part of the display portion  120 , and auxiliary keys  122 , called navigation keys or multi-keys, are provided on the lower part of the display portion  120 .  
         [0040]     The keyboard portion  200 , as illustrated in  FIG. 2 , includes the first keyboard portion  210  and the second keyboard portion  220 , as shown in  FIG. 4 , which are attached on the bottom of the body portion  110  and slide so as to be opened in an opposite direction to each other. The first and second keyboard portions  210  and  220  operate via the operation button  410  provided on the side of the body portion  110 , and will be described in detail later.  
         [0041]     The auxiliary keypad  300  includes a first auxiliary keypad  310  provided on the first keyboard portion  210  and a second auxiliary keypad  320  provided on the second keyboard portion  220 . The first and second auxiliary keypads  310  and  320  are provided with letter keys necessary to create an SMS message. At this time, an alphabetic keyboard may be provided on the first auxiliary keypad  310  and a Hangul keyboard may be provided on the second auxiliary keypad  320 . Also, the locations of the alphabet and Hangul keyboards may be exchanged.  
         [0042]     More specifically, an English keyboard formed in a “qwerty” letter arrangement may be provided on the first auxiliary keypad  310  and a Korean or Chinese keyboard may be, provided on the second auxiliary keypad  320 . Or, an English or Korean keyboard may be provided on the first auxiliary keypad  310 , and numbers and special characters may be provided on the second auxiliary keypad  320 .  
         [0043]      FIGS. 5 and 6  are views for explaining how a keyboard portion is opened by an operation button.  FIG. 5  is an exploded perspective view of the mobile terminal according to the first embodiment of the present invention, and  FIG. 6  is a cross-sectional view of the mobile terminal according to the first embodiment.  
         [0044]     As illustrated in the figures, the present mobile terminal includes an operating unit  400  automatically opening the keyboard portions  210  and/or  220  closed into the terminal body  100  via operation buttons  410  and/or  420 . The configuration of the operating unit  400  is divided into the first operation button  410  opening the first keyboard portion  210  and into the second operation button  420  opening the second keyboard portion  220  as necessary. First, the configuration of opening the first keyboard portion  210  will be described below.  
         [0045]     The operating unit  400  includes a first operation button  410  disposed on one side of the body portion  110  to enable a user to press; a first moving guide  430  attached to the first keyboard portion  210  to be movable in accordance with the pushing of the first operation button  410 ; a first guide groove  435  concavely formed on the rear of the body portion  110  to guide the first moving guide  430 ; and a first elastic body  440  connected to the first moving guide  430  to move the same by an elastic force.  
         [0046]     The first operation button  410  is inversed “T”-shaped, includes a pressing portion  411  extended on one end thereof to help a user to press the first operation button  410 ; a vertical extension portion  412  vertically extended from the pressing portion  411  to pass through a body case  115 ; a horizontal extension portion  413  horizontally extended from the center of the end of the vertical extension portion  412  in both directions; and first and second hooks  414  and  415  curved toward the body case  115  at both ends of the horizontal extension portion  413 .  
         [0047]     The pressing portion  411  is formed to be round and constructed to enable a user to press easily. The vertical extension portion  412  is provided with an elastic spring  416  in the body case  115 . It is preferable that the elastic spring  416  enables the pressing portion  411  of the operation button  410  to be protruded to the outside again after the user releases the same. For this, the elastic spring  416  is initially provided in a slightly compressed state.  
         [0048]     The outer surface shape of the first and second hooks  414  and  415  is formed to be inclined. Also, the outer surface shape of the first and second hooks  414  and  415  may be formed to be curved to have a certain curvature. The first hook  414  is provided to hook a protrusion  432  of the first moving guide  430 , which will be described later. Also, the second hook  415  may further include a rectilinear first fixing guide  433  capable of going in and out from the center of the two guide protrusions  434  in accordance with the pressing of the operation button. Guide protrusions  434  are formed on both ends of the first fixing guide  433 .  
         [0049]     The first moving guide  430  is formed rectilinearly and an anchor portion  431  to which the first elastic body  440  is attached is formed on one end of the first moving guide  430  and a protrusion  432  capable of being hooked by the first hook  414  of the first operation button  410  is formed on the other end of the first moving guide  430 . Also, the anchor portion  431  is joined with a first keyboard portion combining portion  211  protruded in the first keyboard portion  210  to enable the first keyboard portion  210  to interconnect with the first moving guide  430 .  
         [0050]     The width of the first guide groove  435  is formed wider than that of the first moving guide  430 , thereby not impeding the movement of the first moving guide  430 . Also, the length of the first guide groove  435  has to be extended long enough to fully open the auxiliary keypad of the first keyboard portion  210  connected to the first moving guide  430  to the outside, when the first moving guide  430  reaches the end of the first guide groove  435 .  
         [0051]     One end of the first elastic body  440  is attached to an anchoring projection  441 , formed on the bottom of the body portion  110 , and the other end thereof is fixed to the anchor portion  431  of the first moving guide  430 . It is preferable that the first elastic body  440  is a torsion spring, which is “L”-shaped, and forms a layered coil  442  by repeated winding to enhance its elastic force in its middle.  
         [0052]     The configuration of opening the second keyboard portion  220  from the operating unit  400  will be described below. The operating unit  400  includes a second operation button  420  disposed on the body portion  110  opposite to the first operation button  410  to enable a user to press; a second moving guide  450  attached to the second keyboard portion  220  to be movable in accordance with the pushing of the second operation button  420 ; a second guide groove  436  concavely formed on the rear of the body portion  110  to guide the second moving guide  450 ; and a second elastic body  443  connected to the second moving guide  450  to move the same by an elastic force. Also, a second fixing guide  460  is included in the location and configuration corresponding to the first fixing guide  433 .  
         [0053]     The second operation button  420 , the second moving guide  450 , the second fixing guide  460 , the second guide groove  436 , a second keyboard combining portion  222 , and the second elastic body  443  are provided to correspond to the first operation button  410 , the first moving guide  430 , the first fixing guide  433 , the first guide groove  435 , the first keyboard combining portion  211 , and the first elastic body  440 , respectively. Also, the configuration thereof is constructed to be same. Thus, the detailed description related thereto will be omitted.  
         [0054]     Hereinafter, operations and effects according to the first embodiment of the present invention will be described.  
         [0055]     A user presses the pressing portion  411  of the first operation button  410  to draw the first keyboard portion  210  as necessary. While the operation button  410  is being pressed, the protrusion  432  hooked by the first hook  414  of the operation button  410  is being released and the first moving guide  430  moves by an elastic force of the first elastic body  440 . As the first moving guide  430  moves, the first keyboard portion  210  attached thereto also moves to be opened to the outside of the body portion  110 . The first moving guide  430  moves to the end portion of the first guide groove  435 , and the first keyboard portion  210  connected thereto is also opened. In this manner, a user can use an auxiliary keypad provided on the first keyboard portion  210 .  
         [0056]     The user pushes the first keyboard portion  210  toward the body portion  110  to close the first keyboard portion  210 . At this time, the first moving guide  430  connected to the first keyboard portion  210  moves, and the protrusion  432  formed on the other end of the first moving guide  430  goes over the first hook  414 , since the outer surface shape of the first hook  414  is inclined, to move to the inside of the first hook  414 . Accordingly, the protrusion  432  of the first moving guide  430  is again locked via the first hook  414 , and the first keyboard portion  210  connected to the first moving guide  430  is closed into the body portion  110 . At this time, the vertical extension portion  412  of the operation button  410  is provided with the elastic spring  416  in the body case  115 , which enables the operation button  410  to be returned to the previous state which is protruded to the outside.  
         [0057]     Also, the user presses the second operation button  420  to open the second keyboard portion  220 , and the procedures thereof are the same to those of the first operation button  410  and also, the procedures of closing the second keyboard portion  220  are the same to those of the first keyboard portion  210 . Also, the user may select and open only the first or the second keyboard portions  210  and  220  which have the auxiliary keypads the user desires. The user may press both the first operation button  410  and the second operation button  420 , thereby opening both the first and the second keyboard portions  210  and  220 .  
         [0058]     Accordingly, since a user can be provided with an auxiliary keypad as necessary for creating a text message, there is an effect that it is possible to improve the effectiveness in creating a text message. Also, in the case the auxiliary keypad is not used, an auxiliary keypad may be closed. Thus, when a user makes a call, the call is not interfered with. Also, a mobile terminal looks aesthetically pleasing and it is easy to use since it is possible to open and close an auxiliary keypad.  
       Embodiment 2  
       [0059]      FIG. 7  is a cross-sectional view illustrating an operating unit of a mobile terminal according to a second embodiment of the present invention. In describing the second embodiment, identical reference numbers are assigned to portions identical to the portions in the first embodiment, and description related thereto will be omitted.  
         [0060]     As illustrated in  FIG. 7 , a third elastic body  445  connected to the first moving guide  430  and moving the same by an elastic force is also included. The third elastic body  445  is an elastic spring disposed along the guide groove  435 , and one end of the third elastic body  445  is connected to an anchor portion  431  of the first moving guide  430  and the other end of the third elastic body  445  is attached to a projection  446  formed on the end portion of the guide groove  435 . It is preferable that the third elastic body  445  is initially provided in a tense state to pull the first moving guide  430 .  
         [0061]     The first moving guide  430  moves by an elastic force of the third elastic body  445  and as the first moving guide  430  moves, the first keyboard portion  210  attached thereto is also opened to the outside of the body portion  110 . This is the same as the first embodiment. At this time, the first moving guide  430  may collide into the projection  446  formed on the end of the guide groove  435 . Thus, it is preferable that the projection  446  is formed of an elastic material such as rubber in order to prevent noise and damage to the respective elements. Similarly, an elastic body capable of opening the second keyboard portion  220  may be configured. Thus, the “L”-shaped first elastic body  440 , which has been described in the first embodiment, may be used to open the first keyboard portion  210 , and the third elastic body  445 , which has been described in the second embodiment, may be used to draw the second keyboard portion  220 .  
       Embodiment 3  
       [0062]      FIG. 8  is a perspective view of a mobile terminal according to a third embodiment of the present invention, in which a game keyboard may be provided on the auxiliary keyboard  300 . As illustrated in  FIG. 8 , direction keys may be provided on the first auxiliary keypad  330  to control the movement of an avatar in a game, and a plurality of operation keys may be provided on the second auxiliary keypad  340  at a proper interval so as not to interfere with each other. Particularly, in the case of operation buttons, a user has to repeatedly press the operation buttons to play a game. Thus, the operation buttons need to be large and disposed to be spaced apart from each other at a certain interval. The auxiliary keypad may provide the space as above.  
         [0063]      FIG. 9  is a perspective view illustrating another modified example of the third embodiment, in which the display portion  130  may be constructed to slide along the width of the body portion  110 , not slide along the length of the body portion  110 . In the configuration as above, the display portion  130  may slide to be opened to expose input keys  113  provided on the body portion  110  in a situation where the auxiliary keyboards  210  and  220  are opened. In this configuration, since not only the auxiliary keyboards  210  and  220  but also the input keys  113  may be used, the configuration as above is particularly suitable for a game.  
         [0064]     Namely, direction keys and operation buttons should be provided on the auxiliary keypads  330  and  340  to enable a user to play a game. Because the features of a game require the user to click direction keys or operation buttons repeatedly and consecutively, the size of the button should be constructed to be large and in particular, a certain spatial interval should be maintained between buttons so as an adjacent button is not inadvertently pressed and causes interference with the button the user intentionally presses. Thus, the number of buttons which may be provided on the auxiliary keyboards  210  and  220  may be limited. Also, since there are various kinds of games, the number of input buttons required is also different. Accordingly, in the case an additional button apart from the auxiliary keyboards  210  and  220  is required, the input keys  113  provided on the body portion  110  may be used by opening the display portion  130 .  
       Embodiment 4  
       [0065]     Briefly describing the operations of this fourth embodiment to easily understand, in the present embodiment, unlike the first embodiment, in the case the display portion is open, a keyboard portion provided with an auxiliary keypad is not opened even though a user presses an operation button. Namely, although the user opens the display portion and inadvertently presses the operation button when making a call, the keyboard portion is not opened. Thus, the keyboard portion does not interrupt the call.  
         [0066]     The configuration related thereto will be described in detail with reference to  FIG. 10 .  FIG. 10  is an exploded perspective view according to the fourth embodiment of the present invention. As illustrated, the mobile terminal of the present invention includes a terminal body  100 , a keyboard portion  200 , an auxiliary keypad provided on the keyboard portion  200 , and an operating unit  600 .  
         [0067]     The terminal body  100  includes a body portion  110  embedded with a communicable circuit member and a display portion  120  to be slidable up and down lengthwise on the body portion  110 . The body portion  110  is provided with a plurality of input keys  111  in the shape of a button to enable a user to input a number and a letter. A microphone  112  capable of receiving an audio signal is provided on one side of the body portion  110 . Also, although not illustrated in this figure, a battery supplying power is provided. Operation buttons  510  and  520  capable of opening the keyboard portion  200  are provided on the side of the body portion  110 .  
         [0068]     The keyboard portion  200  includes a first keyboard portion  210  and a second keyboard portion  220  which are attached to the bottom of the body portion  110  and may slide to be opened in opposite directions from each other. The first and second keyboard portions  210  and  220  open via the operation buttons  510  and  520  provided on the side of the body portion  110 . As described above, what is different from the first embodiment is that the first keyboard portion  210  and the second keyboard portion  220  are not opened when the display portion  120  is opened, although a user may press the operation buttons  510  and/or  520 .  
         [0069]     Like the first embodiment, the display portion  120  may include a display displaying visual information, navigation keys provided with a speaker outputting audio information, or auxiliary keys referred to as multi-keys. Also, a combination block  125  capable of pushing a rotating block  610  to rotate when the display portion  120  is opened is formed to be protruded on the bottom of the display portion  120 . The rotating block  610  will be described later.  
         [0070]     The body portion  110  includes the operating unit  600  automatically opening the keyboard portions  210  and/or  220  via the operation buttons  510  and/or  520 , but not opening the keyboard portions  210  and  220  when the display portion  120  is open, although a user may press the operation buttons  510  and/or  520 . The preceding will be described in detail below with reference to FIGS.  11  to  15 .  FIG. 11  is an exploded perspective view of an operating unit according to the fourth embodiment of the present invention,  FIG. 12  is a perspective view illustrating the appearance of the operating unit in the case a display portion according to the fourth embodiment of the present invention is closed,  FIG. 13  is a cross-sectional view illustrating along A-A′ line of  FIG. 12 ,  FIG. 14  is a perspective view illustrating the operating unit when the display portion according to the fourth embodiment of the present invention is opened, and  FIG. 15  is a cross-sectional view illustrating along B-B′ line of  FIG. 14 .  
         [0071]     The configuration of the operating unit  600  is divided into the configuration of including the first operation button  510  opening the first keyboard portion and into the configuration of including the second operation button  520  opening the second keyboard portion as necessary. First, the configuration of opening the first keyboard portion will be described below.  
         [0072]     The operating unit  600  includes the first operation button  510  disposed on one side of the body portion  110  to enable a user to press; a first moving guide  430  attached to the first keyboard portion to be movable in accordance with the pushing of the first operation button  510 ; a first guide groove  435  concavely formed on the rear of the body portion  110  to guide the first moving guide  430 ; a first elastic body  440  connected to the first moving guide  430  to move the same by an elastic force; and the rotating block  610  preventing the movement of the first operation button  510  in the case the display portion  120  is open and not interfering with the movement of the first operation button  510  in the case the display portion  510  is closed.  
         [0073]     The first operation button  510  is “T”-shaped, includes a pressing portion  511  extended on one end thereof to help a user to press the first operation button  510 ; a vertical extension portion  512  vertically extended from the pressing portion  511  to pass through a body case  115 ; a horizontal extension portion  513  horizontally extended from the center of one part of the vertical extension portion  512  in both directions; first and second hooks  514  and  515  curved toward the outside of the body case  115  at both ends of the horizontal extension portion  513 ; and a first braking portion  517  formed on the vertical extension portion  512  and extending to be formed on the end opposite to the pressing portion  511 .  
         [0074]     The pressing portion  511  is processed to be round and constructed to help a user to press easily. The vertical extension portion  512  is provided with an elastic spring  516  in the body case  115 . It is preferable that the elastic spring  516  enables the pressing portion  511  of the operation button  510  to be protruded to the outside again after the user presses the same. For this, the elastic spring  516  is initially provided in a slightly compressed state.  
         [0075]     The outer shape of the first and second hooks  514  and  515  is formed to be inclined. The first hook  514  is provided to hook a protrusion  432  of the first moving guide  430 , which will be described later. Also, the second hook  515  may further include a rectilinear first fixing guide  433  capable of going in and out from the center of the two guide protrusions  434  in accordance with the pressing of the first operation button  510 . Guide protrusions  434  are formed on both ends of the first fixing guide  433 .  
         [0076]     The first moving guide  430  is formed rectilinearly and an anchor portion  431  to which the first elastic body  440  is attached to is formed on one end of the first moving guide  430  and a protrusion  432  capable of being hooked by the first hook  514  of the first operation button  510  is formed on the other end of the first moving guide  430 . Also, the anchor portion  431  is joined with a first keyboard portion combining portion (not illustrated) protruded in the first keyboard portion to enable the first keyboard portion to interconnect with the first moving guide  430 . This is the same as the first embodiment.  
         [0077]     The width of the first guide groove  435  is formed a slightly wider than that of the first moving guide  430 , thereby not interfering with the movement of the first moving guide  430 . Also, the length of the first guide groove  435  has to be extended long enough to fully open the auxiliary keypad of the first keyboard portion connected to the first moving guide  430 , when the first moving guide  430  reaches the end of the first guide groove  435 .  
         [0078]     One end of the first elastic body  440  is attached to an anchoring projection  441  formed on the bottom of the body portion  110  and the other end thereof is attached to the anchoring portion  431  of the first moving guide  430 . It is preferable that the first elastic body  440  is a torsion spring, which is “L”-shaped, and forms a layered coil  442  by repeated winding to enhance its elastic force in its middle.  
         [0079]     The rotating block  610  is in the shape of a hexahedron and one side thereof is formed to be inclined. Also, the rotating block  610  is constructed to be rotatable around an axial projection  611  which is formed on both sides, and a leaf spring  612  is connected to the opposite side of the rotating block  610  from the axial projection  611  to give the force of restitution. The rotating block  610  is disposed between the first operation button  510  and the second operation button  520  to block or allow the moving course of the first and second operation buttons  510  and  520  as dictated by its rotation. A part of the rotating block  610  is protruded outside the body case  115  through a hole formed in the body case  115 . The rotating block  610  protruded outside the body case  115  is configured to rotate while making contact with the combination block  125  provided on the display portion  120 .  
         [0080]     Hereinafter, operations and effects according to the fourth embodiment of the present invention will be described below.  
         [0081]     The fourth embodiment works differently with respect to the display portion  120  being opened or closed. First, the case when the display portion  120  is closed will be described below with reference to  FIGS. 12 and 13 .  
         [0082]     A user presses the pressing portion  511  of the first operation button  510  to open the first keyboard portion as necessary. At this time, the combination block  125  of the display portion  120  and the rotating block  610  provided on the body portion  110  are spaced apart at a certain interval. In this case, like the first embodiment, while the operation button  510  is being pressed, the protrusion  432  hooked by the first hook  514  of the operation button  510  is released and the first moving guide  430  moves by an elastic force of the first elastic body  440 . As the first moving guide  430  moves, the first keyboard portion attached thereto also moves to be opened to the outside of the body portion  110 . The first moving guide  430  moves to the end portion of the first guide groove  435 , and the first keyboard portion connected thereto is also opened. In this manner, a user can use an auxiliary keypad provided on the first keyboard portion.  
         [0083]     To close the first keyboard portion as necessary, the user pushes the first keyboard portion toward the body portion  110  to close the first keyboard portion, which is also the same as the first embodiment. At this time, the first moving guide  430  connected to the first keyboard portion moves, and the protrusion  432  formed on the end of the first moving guide  430  goes over the first hook  514  since the outer surface shape of the first hook  514  is inclined. Accordingly, the protrusion  432  of the first moving guide  430  is locked in place again via the first hook  514 , and the first keyboard portion connected to the first moving guide  430  is closed and concealed by the body portion  110 . At this time, the vertical extension portion  512  of the operation button  510  is provided with an elastic spring  516  in the body case  115 , which enables the operation button  510  to be re-protruded to the outside.  
         [0084]     Also, the user presses the second operation button  520  to open the second keyboard portion, and the procedures thereof are the same to those of the first operation button  510  and also, the procedures of closing the second keyboard portion are the same to those of the first keyboard portion. Also, the user may select and open either the first or the second keyboard portion having the auxiliary keypad the user wants to use. The user may also press both the first operation button  510  and the second operation button  520 , thereby drawing both the first and the second keyboard portions.  
         [0085]     Next, the case in which the display portion  120  slides to be opened will be described below with reference to  FIGS. 14 and 15 .  
         [0086]     While the display portion  120  slides forward, the combination block  125  provided on the display portion  120  makes contact with the rotating block  610  provided on the body portion  110 . The combination block  125  pushes the rotating block  610  to rotate within the range of about 20° to 90° around the axial projection  611 . The rotating block  610  rotates to be disposed between the first operation button  510  and the second operation button  520 . In this state, the user may press the first operation button  510 , but the first operation button  510  is making contact with the rotating block  610 . Thus, the first operation button  510  does not move. Namely, the first hook  514  of the first operation button  510  does not move to release the protrusion  432  of the first moving guide  430  and thus, the first keyboard portion is not opened. Similarly, the user may press the second operation button  520 , but the second operation button  520  is making contact with the rotating block  610 . Thus, the second operation button  520  does not move and the second keyboard portion  220  is not opened.  
         [0087]     Accordingly, in the case a display portion is closed, a user may use an auxiliary keypad to create a text message, as necessary. Thus, the effectiveness in creating a text message may be improved. Also, in case of not using an auxiliary keypad, the auxiliary keypad may be concealed. Thus, when a user makes a call, the call is not interfered with. Also, the mobile terminal is aesthetically pleasing and is easy to use since it is possible to open and close an auxiliary keypad. Furthermore, in case of opening the display portion to make a call, although the user may inadvertently or intentionally press an operation button, the auxiliary keypad is not opened. Thus, the user can make a call without interference.  
         [0088]     As described above, in the present embodiment, the rotating block  610  may be constructed to be disposed between the first operation button  510  and the second operation button  520 , thereby binding the first and second operation buttons  510  and  520  simultaneously when the rotating block  610  rotates. In contrast to this, the rotating block  610  may also be constructed to bind only the first operation button  510  and not bind the second operation button  520  when the rotating block  610  rotates. In this way, even when the display portion  120  is opened, the second keyboard portion may be configured to be opened via the second operation button  520 . This method is constructed to provide a necessary auxiliary keyboard to the second keyboard portion in the case a user opens the display portion  120  for its use, such as making a call, thereby enabling the second keyboard portion to be open by using the second operation button  520  even when the display portion  120  is open.  
         [0089]     According to the present embodiment, since a user can be provided with an auxiliary keypad as necessary for creating a text message, the effectiveness in creating a text message can be improved.  
         [0090]     Also, in the case an auxiliary keypad is not used, an auxiliary keypad can be concealed. Thus, when a user makes a call, the user can make a call without interference. Also, a mobile terminal is aesthetically pleasing and is easy to use since the auxiliary keypad can be closed and concealed by the body portion  110 .  
         [0091]     Also, since game keys can be provided through an auxiliary keypad, a user can have more fun playing a game.  
         [0092]     Also, in the case a user opens a display portion to make a call, although the user may inadvertently or intentionally press an operation button, an auxiliary keypad is not opened. Thus, the call is not interfered with.  
         [0093]     While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.