Abstract:
A mobile terminal having a first body, a second body slidably attached to the first body, and means for connecting the first body to the second body and allowing the second body to be moved between a closed position and an open position such that an overall thickness of the mobile terminal in the open position is thinner than an overall thickness of the mobile terminal in the closed position. The means includes a slide mechanism having at least one rail mechanism attached to the first body; and at least one slider mechanism attached to the second body and slidably engaged with the at least one rail mechanism.

Description:
This application claims the benefit of Korean Patent Application No. 10-2005-0121800, filed on Dec. 12, 2005, and Korean Patent Application No. 10-2006-0032337, filed on Apr. 10, 2006, which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a mobile terminal and more particularly, to a sliding type mobile terminal having a slide mechanism 
     2. Description of Related Art 
       FIGS. 1A and 1B  show a conventional slide type mobile terminal. The slide type mobile terminal includes a body module  10  and a cover module  20  assembled to a top surface of the body module  10  to allow for sliding motion. 
     The body module  10  includes a keypad  11  for signal inputs of various symbols, a microphone  12  to input audio signals, and a battery cover  13 . The cover module  20  includes an LCD (liquid crystal display) screen  21  for displaying pictures, a speaker  22  for outputting sound, and a plurality of function keys  23  to execute special functions performable by the slide type mobile terminal. 
     As seen in  FIG. 1B , the back of the cover module includes a pair of slots  24  that cooperate with a pair of members (not shown) extending from a front surface of the body module  10 . The length of the slots  24  determines the extent to which the cover module  20  moves in relation to the body module  10 . As shown in  FIGS. 1A and 1B , the cover module  20  is supported by the body module  10  in such a manner that the overall thickness of the slide type mobile terminal does not change as the cover module  20  moves between open and closed positions. 
     As noted, conventional slide type mobile terminals suffer from various shortcomings including that the mobile terminal remains bulky when in use. Because of the change in profile, some mobile terminal can be awkward to hold. Finally, because the slide mechanisms are exposed to a great extent while in the open position, the slide mechanism can collect dirt and other particles therein, thereby effecting the operation of the slide mechanism or the mobile terminal itself. 
     The present invention attempts to overcome these defects by providing a slide mechanism that allows the cover module to slide and drop into a position where the body module and cover module may have the same profile. In addition, the slide mechanism is arranged to limit the exposure of the slide mechanism. 
     BRIEF SUMMARY OF THE INVENTION 
     According to principles of this invention, the present invention solves the problems identified above. In a first aspect of the present invention, a mobile terminal includes a first body having a front and rear surface, a second body slidably attached to the first body, the second body having a front and rear surface, and a slide mechanism connecting the first body to the second body. The slide mechanism allows the second body to be moved between a closed position and an open position such that an overall thickness of the mobile terminal in the open position is thinner than an overall thickness of the mobile terminal in the closed position and the front and rear surfaces of the first and second bodies are uninterrupted by the slide mechanism. 
     In a further aspect, the slide mechanism may include at least one rail mechanism attached to the first body, and at least one slider mechanism attached to the second body and slidably engaged with the at least one rail mechanism. 
     In yet a further aspect, the at least one slider mechanism includes a follower and the at least one rail mechanism includes a guide groove configured to receive the follower. 
     In a different aspect, the at least one slider mechanism includes a slider body supported by the at least one rail mechanism and a linkage arm having a first end pivotally connected to the second body and a second end connected to the slider body. 
     In a further aspect, the at least one slider mechanism includes a torsion spring configured to assist in moving the second body from the closed position to the open position. 
     In a second aspect of the present invention, a mobile terminal includes a first body, a second body slidably attached to the first body, and means for connecting the first body to the second body and allowing the second body to be moved between a closed position and an open position such that an overall thickness of the mobile terminal in the open position is thinner than an overall thickness of the mobile terminal in the closed position. 
     In a third aspect of the present invention, a mobile terminal includes a first body having an upper surface and a lower surface, where the lower surface defines a first plane. The mobile terminal also includes a second body slidably attached to the first body, the second body having an upper surface defining a second plane and a lower surface. The second plane is substantially parallel to the first plane when the second body is in a closed position. A slide mechanism connects the first body to the second body. The slide mechanism allows the second body to be moved between a closed position and an open position such that the second plane is parallel to the first plane in the closed position and the elevation between the first plane and second plane in the closed position is greater than the elevation between the first plane and second place in the open position. In addition, the upper surface of the first body and the lower surface of the second body are uninterrupted by the slide mechanism. 
     Further scope of applicability of the present application will become more apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
         FIGS. 1A and 1B  are perspective diagrams of a slide type mobile terminal according to a related art; 
         FIGS. 2A and 2B  show a front diagram of a slide type mobile terminal and side view of the slide type mobile terminal, respectively, according to the present invention, with the slide type mobile terminal in a closed position; 
         FIGS. 3A and 3B  show a front diagram of a slide type mobile terminal and side view of the slide type mobile terminal, respectively, according to the present invention, with the slide type mobile terminal in an open position; 
         FIG. 4  is an exploded perspective diagram of a slide mechanism according to a first embodiment of the present invention; 
         FIGS. 5A to 5C  are side diagrams to explain a process of a sliding motion of a cover module using the slide mechanism shown in  FIG. 4 ; 
         FIG. 6  is an exploded perspective diagram of a slide mechanism according to a second embodiment of the present invention; 
         FIGS. 7A to 7C  are side diagrams to explain a process of a sliding motion of a cover module using the slide mechanism shown in  FIG. 6 ; 
         FIG. 8  is a perspective diagram of a slide mechanism according to a third embodiment of the present invention; 
         FIGS. 9A and 9B  are side diagrams to explain a process of a sliding motion of the slide mechanism shown in  FIG. 8 ; 
         FIGS. 10A and 10B  are diagrams to explain motions of a link and an elastic member configuring the slide mechanism shown in  FIGS. 9A and 9B ; and 
         FIGS. 11A to 11C  are side diagrams to explain a process of a sliding motion of a cover module using the slide mechanism shown in  FIG. 8 , and  FIGS. 11A-1  to  11 C- 1  are more detailed views of the slide mechanism of  FIG.8 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
       FIGS. 2A and 2B  show a front diagram of a slide type mobile terminal and a side view of the slide type mobile terminal, respectively, according to the present invention, with the slide type mobile terminal in a closed position.  FIGS. 3A and 3B  show a front diagram of the slide type mobile terminal and a side view of the slide type mobile terminal, respectively, according to the present invention, with the slide type mobile terminal in an open position 
     Referring to  FIGS. 2A and 2B , a slide type mobile terminal according to the present invention includes a body module  100  and a cover module  200  positioned above a top or front surface of the body module  100 . The cover module  200  is slidable with respect to the body module and will be described in further detail below. 
     As best seen in  FIG. 3A , the body module  100  includes a keypad  110  for signal inputs of various symbols and a microphone  120  to input audio signals. The body module  100  includes a front surface that defines an upper plane and a lower surface that defines a lower plane. The cover module  200  includes an LCD (liquid crystal display) screen  210  for displaying pictures, a speaker  220  for outputting sound, and a plurality of function keys  230  for executing special functions of the slide type mobile terminal. The cover module  200  includes a front surface that defines an upper plane and a lower surface that defines a lower plane. 
     An incline  130  is provided at a middle portion of a top of the body module  100 . Another incline  240  corresponding to incline  130  of the body module  100  is provided at a middle portion of a bottom of the cover module  200 . In this first exemplary embodiment, each of the inclines  130 ,  240  of the body and cover modules  100 ,  200  is configured to incline downwardly. In this case, an upper thickness A 2  of the body module  100  is formed smaller than a lower thickness Al of the body module  100  and an upper thickness B 2  of the cover module  200  is formed greater than a lower thickness B 1  of the cover module  200 . Alternatively, the inclines  130 ,  240  can be configured to incline upward. In this case, the upper and lower thickness of the body and cover modules  100 ,  200  are reverse to those of the case of the downward inclines. 
     As a result, the inclines  130 ,  240  of the body and cover modules  100 ,  200  enable vertical motions of the cover module  200  with respect to the body module  100 . Because of such motions, the distance between the lower plane of the body module  100  and the upper plane of the cover module  200  is smaller when in the open position as compared to the closed position. 
     Referring to  FIGS. 3A and 3B , a vertical motion of the cover module  200  is carried out in a manner that a lower part of the cover module  200  slides along the incline  130  of the body module  100  as soon as the incline  240  of the cover module  200  slides along an upper part of the body module  100 . 
     After completion of the slide motion of the cover module  200 , the keypad  110  of the body module  100  is completely exposed. In addition, a thickness of the mobile terminal becomes equal to the lower thickness A 1  of the body module  100  or the upper thickness B 2  of the cover module  200 , thereby becoming reduced overall. In particular, although a total thickness of the mobile terminal prior to a slide motion of the cover module  200  is (A 1 +B 1 ) or (A 2 +B 2 ), the thickness of the mobile terminal becomes A 1  or B 2  after completion of the slide motion of the cover module  200 . Specifically, in a case where the lower thickness A 1  of the body module  100  is equal to the upper thickness B 2  of the cover module  200 , the overall thickness of the mobile terminal becomes uniform after completion of the slide motion of the cover module  200 . 
     In order to accomplish the above motion, a slide mechanism is provided that connects the body and cover modules  100 ,  200  to allow the cover module  200  to move in a horizontal and a vertical direction. 
       FIG. 4  is an exploded perspective diagram of a slide mechanism according to a first embodiment of the present invention, and  FIGS. 5A to 5C  are side diagrams to explain a process of a sliding motion of a cover module using the slide mechanism shown in  FIG. 4 . The slide mechanism according to a first embodiment of the present invention includes a slide rail  310  fixed to an inside of the body module  100  and a slider or slider mechanism  320  attached to the cover module  200 . The slide rail  310  includes a bent portion that extends at the same angle as incline  130  of the body module  100 . One end of the slider  320  is fixed to an inside of the cover module  200 , while the other end is movably connected to the slide rail  310 . 
     In particular, the slide rail  310  includes a pair of horizontal rails  311  extending toward a middle part of the body module  100  from a lower part of the body module  100  and a pair of incline rails  312  extending from a pair of the horizontal rails  311  to be bent at the same angle of the incline  130  of the body module  100 , respectively. When the slider  320  is moved along the horizontal and incline rails  311 ,  312  by an external force, horizontal and vertical motions of the cover module  200  occurs. 
     Specifically, when the slider  320  moves along the horizontal rails  311 , the horizontal motion of the cover module  200  takes place. When the slider  320  moves along the incline rails  312 , a horizontal and vertical motion of the cover module  200  takes place. It is this motion that allows the mobile terminal to have a smaller profile in the open position than in the closed position. 
     To couple the slide rail  310  and the slider  320  together, a guide groove  313  is provided in slide rail  310  and a guide projection or follower  321  is provided, on the slider  320  to be fitted into the guide groove  313 , thereby providing for the sliding motion. Optionally, a plurality of guide projections  321  can be provided on the slider  320  if desired. 
     Preferably, a roller  322  is provided on the guide projection  321 . The roller  322  rotates by being fitted in the guide groove  313 , thereby enabling a smooth motion of the slider  320  and preventing abrasion of the guide projection  321  due to friction with the slide rail  320 . The roller  322  is preferably formed of a metal based material or a plastic based material such as POM (polyoxymethylene) that is resistant against friction. Alternatively, the guide projection  321  can be replaced by a ball bearing (not shown in the drawing) to be provided to the slider  320 . The ball bearing enables the smooth motion of the slider  320  and minimizes the friction with the slide rail  310  in case of movement of the slider  320 . 
     A support plate  314  may also be provided between a pair of the horizontal rails  311 . The support plate  314  can assist in uniformly maintaining a gap in the slide rail  310  between the horizontal rails  311  to enable the slider  320  to move along the slide rail  310  into either the open or closed position. In addition, the support plate  314  may facilitate installation of the slide rail  310 . For example, a user is able to complete the installation of the slide rail  310  in a manner of pushing the support plate  314  into the body module  100  by inserting the support plate  314  into a corresponding cavity. 
     Optionally, it is possible to provide the support plate  314  between the incline rail  312  and the slider  320 . Yet, in this case, since a space between the incline rail  312  and the slider  320  is not usable, it is preferable that the support plate  314  be provided between a pair of the horizontal rails  311  only. 
     Referring to  FIG. 5A  and  FIG. 5B , a process of the slide motion of the cover module  314  by the above-configured slide mechanism according to the first embodiment of the present invention is explained. 
     If an external force is applied to the cover module  200  by a user to execute a new function such as a calling and the like while the slider  320  is coupled with the horizontal rails  311 , the slider  320  moves along the horizontal rail  311  according to a rotation of the roller  322  or other movement of guide projection  321 . Thus, as the slider  320  moves along the horizontal rails  311 , the horizontal motion of the cover module  200  coupled with the slider  320  is carried out. 
     Referring to  FIG. 5C , as soon as the slider  320  moves along the incline rails  312 , the lower part of the cover module  200  slides down along the incline  130  of the body module  100  and the incline  240  of the cover module  200  slides to move along the upper part of the body module  100 . Thus, the horizontal and vertical motion of the cover module  200  is carried out. 
     After completion of the horizontal and vertical motions of the cover module  200 , the thickness of the mobile terminal becomes equal to the lower thickness A 1  of the body module  100  or the upper thickness B 2  of the cover module  200  to achieve the slimness of the mobile terminal. If the lower thickness A 1  of the body module  100  and the upper thickness B 2  of the cover module  200  are equal to each other, the overall thickness of the mobile terminal is uniform after completion of the slide motion of the cover module  200 . 
       FIG. 6  is an exploded perspective diagram of a slide mechanism according to a second embodiment of the present invention, and  FIGS. 7A to 7C  are side diagrams to explain a process of a sliding motion of a cover module using the slide mechanism shown in  FIG. 6 . 
     Referring to  FIGS. 6 ,  7 A, and  7 B, a slide mechanism according to a second embodiment of the present invention includes a first slide rail  410  fixed within the body module  100 , a second slide rail  420  fixed within the cover module  200 , a first slider or slider mechanism  430  coupled with the second slide rail  420 , and a second slider or slider mechanism  440  coupled with the first slide rail  410 . 
     The first slide rail  410  has a portion that is bent at the same angle as the incline  130  of the body module  100 , and the second slide rail  420  also has a portion that is bent at the same angle as the incline  240  of the cover module  200 . The first slider  430  extends from the first slide rail  410 , while the second slider  440  extends from the second slide rail  420 . In particular, the first slide rail  410  includes a pair of first horizontal rails  411  extending from the lower part of the body module  100  toward the middle part of the body module  100  and a pair of first incline rails  412  extending from the first horizontal rail  411  to be bent at the same angle as the incline  130  of the body module  100 . The second slide rail  420  includes a pair of second horizontal rails  421  extending from the upper part of the cover module  200  toward the middle part of the cover module  200  and a pair of second incline rails  422  extending from the second horizontal rail  421  to be bent at the same angle of the incline  240  of the cover module  200 . 
     Hence, when the first and second sliders  430 ,  440  move along the second and first horizontal rails  421 ,  411 , respectively, by an external force applied to the cover module  200 , the horizontal motion of the cover module  200  is carried out. When the first and second sliders  430 ,  440  move along the second and first incline rails  422 ,  412 , respectively, by the external force, the horizontal and vertical motion of the cover module  200  is carried out. 
     In particular, when the first slider  430  moves along the second horizontal rails  421 , the second slider  440  moves along the first horizontal rails  411 . When the first slider  430  moves along the second incline rails  422 , the second slider  440  moves along the first incline rails  412 . In actuality, the first slider  430  does not move along the second slide rail  420 , rather it remains stationary with the body module  100  and the second slide rail  420  substantially moves together with the cover module  200 . 
     Meanwhile, the first slider  430  extends from the first incline rails  412  to be coupled with the second slide rail  420 . And, the second slider  440  extends from the second horizontal rails  421  to be coupled with the first slide rail  410 . Unlike the second slider  440 , the first slider  430  extends from the first incline rails  412 . This is to prevent the contact between the cover module  200  and the first slider  430  according to the vertical motion of the cover module  200 . 
     In particular, if the first slider  430  were to extend from the first horizontal rails  411 , the first slider  430  would be placed on a moving path of the cover module  200  to restrict the motion of the cover module  200  (see  FIG. 7B  and  FIG. 7C ). In this case, in order to achieve the vertical motion of the cover module  200 , a separate space for accommodating the first slider  430  should be provided within the cover module  200 . For ease of manufacture of the mobile terminal, it is preferable that the first slider  430  is configured to extend from the first incline rails  412  rather than the first horizontal rails  411 . 
     Because the first slider  430  extends from the first incline rails  412 , the first slider  430  is located below the second slide rail  420  and an extension  450  is provided to an end portion of the first slider  430  to compensate for a height difference from the second slide rail  420 . In this exemplary embodiment, the extension  450  is assembled to the second slide rail  420 . 
     In order to couple the first and second slide rails  410 ,  420  with the second and first sliders  440 ,  430 , respectively, guide grooves  413 ,  423  are provided on the first and second slide rails  410 ,  420 , respectively. Guide projections or followers  451 ,  441  are provided on the extension  450  and the second slider  440 , respectively, and are to be fitted into the guide grooves  423 ,  413  to allow for a sliding motion, respectively. The guide projections  451  and  441  can include multiple guide projections if necessary. 
     Preferably, rollers  460  are provided on the guide projections  451 ,  441 . Alternatively, ball bearings (not shown in the drawing) can be provided on the extension  450  and the second slider  440  to replace the guide projections  451 ,  441 , respectively. The rollers  460  and the ball bearings have been explained in the foregoing description of the first embodiment of the present invention, of which detailed explanations will be omitted in the following description. 
     A support plate  414  may be provided between the first horizontal rails  411  and another support plate  424  may be provided between the second horizontal rails  421 . The support plate  414  can maintain an interval of the first slide rail  410  uniformly to enable the second slider  440  to move between and open and closed position along the first slide rail  410 . The other support plate  424  can maintain an interval of the second slide rail  420  uniformly to enable the first slider  430  to move to between and open and closed position along the second slide rail  420 . In addition, the support plates  414  and  424  may facilitate installations of the first and second slide rails  410  and  420 , respectively. In particular, a user is able to complete the installations of the first and second slide rails  410 ,  420  in a simple manner of pushing the support plates  414 ,  424  into positions determined within the body and cover modules  100 ,  200 , respectively. 
     Referring to  FIG. 7A  and  FIG. 7B , if an external force is applied to the cover module  200  by a user to execute a new function such as a calling and the like while the first and second sliders  430 ,  440  are coupled with the second and first slide rails  420 ,  410 , respectively, the first and second sliders  430 ,  440  move along the second and first horizontal rails  421 ,  411 , respectively, according to rotations of the rollers  460  or other movement of guide projection  451 ,  441 , respectively. Thus, the horizontal motion of the cover module  200  is carried out. 
     Referring to  FIG. 7C , as soon as the second slider  440  moves along the first incline rails  412  and the first slider  430  moves along the second incline rails  422 , the horizontal and vertical motion of the cover module  200  is carried out. 
     After completion of the horizontal and vertical motions of the cover module  200 , the thickness of the mobile terminal becomes equal to the lower thickness A 1  of the body module  100  or the upper thickness B 2  of the cover module  200  to achieve the slimness of the mobile terminal. If the lower thickness A 1  of the body module  100  and the upper thickness B 2  of the cover module  200  are equal to each other, the overall thickness of the mobile terminal is uniform after completion of the slide motion of the cover module  200 . 
       FIG. 8  is a perspective diagram of a slide mechanism according to a third embodiment of the present invention. The slide mechanism includes a slider or slider body  520 , a guide part  510  and a link or linkage arm  530 . It does not matter whether the guide part  510  is provided on the body module  100  or the cover module  200 . In the following description, it is assumed that the guide part  510  is provided on the body module  100 . 
     The guide part  510  is provided within the body module  100  and configures a horizontal motion path of the cover module  200 . The slider  520  is movably coupled with the guide part  510  to carry out horizontal reciprocations for the slide motion of the cover module  200 . One side of the link  530  is coupled with the slider  520 , while the other is coupled with the cover module  200 , which allows the link  530  to be turned to provide further horizontal and vertical motion of the cover module  200  (see  FIG. 8 ,  FIG. 9A  and  FIG. 9B ). 
     In particular, the guide part  510  is configured to have a plate shape and rails are provided on both sides of the guide part  510 , respectively. The slider  520  is coupled with each of the rails of the guide part  510 . Alternatively, a pair of sliders  520  can be provided to be coupled with the rails of the guide part  510 , respectively. Yet, in the present embodiment, one slider  520 , as shown in the drawing, is used and configured to enclose the guide part  510  and be coupled with the rails of the guide part  510 . 
     One end of the link  530  is connected to the slider  520  by a shaft  541 , and the other is connected to the cover module  200  by another shaft  542 . The link  530  is connected to the slider  520  and the cover module  200  by the shafts  541 ,  542 , respectively. As a result, the link  530  is able to rotationally move with respect to the slider  520  and the cover module  200 . Although the link  530  has been described in a specific manner, the present invention may employ any rotationally movable configurations apparent to those skilled in the art. For example, the shafts  541 ,  542  may be provided on the slider  520  and the cover module  200 , respectively, to be coupled with the link  530 . Alternatively, the shafts  541 ,  542  may be provided on the link  530  and are to be coupled with the slider  520  and the cover module  200 , respectively. In yet another alternative, the shafts  541 ,  542  are separately provided to connect an upper portion of the link  530  to the cover module  200  and to connect a lower portion of the link  530  to the slider  520 . 
     To enable the link  530  to turn to provide both horizontal and vertical motion of the cover module  200 , the shafts  541 ,  542  are moveable in and out of a vertical orientation in a lateral direction of the cover module  200  and a moving direction of the slider  520 . 
     An elastic member  550  can be further provided on the slide mechanism. The elastic member  550  applies a force to the cover module  200  to provide an elastic force enabling the cover module  200  to make both a horizontal and vertical sliding motion in a direction of opening the body module  100 . 
     Referring to  FIGS. 10A and 10B , when the cover module  200  makes both a horizontal and a vertical motion after completion of a horizontal motion to open the body module  100 , the elastic member  550  provides an elastic force to the cover module  200  to automatically turn the cover module  200 . In the present embodiment, the elastic member  550  automatically moves the cover module  200  in both a horizontal and vertical direction in a manner of turning the link  530  by applying the elastic force to the link  530 . Alternatively, the elastic member  550  may be able to move the cover module  200  by applying the elastic force to the cover module  200  directly. 
     As mentioned in the foregoing description, in order to turn the link  530 , the elastic member  550  can include a torsion spring. In particular, one side of the torsion spring is connected to the link  530  and the other side is connected to the slider  520  to turn the link  530 . As the link  530  is turned, the cover module  200  moves in both a horizontal and vertical direction of opening the body module  100 . 
     In particular, the torsion spring includes a coil portion  550   a  generating a torsion moment as a central portion and a pair of extension blades  550   b  extending from both ends of the coil portion  550   a . Preferably, the coil portion  550   a  is fixed. 
     One side of the elastic member  550  is connected to the link  530 , the other side of the elastic member  550  is connected to the slider  520 , and the central portion of the elastic member  550  is connected to the shaft  541 . Preferably, the coil portion  550   a  of the torsion spring is connected to the shaft  541  connecting the link  530  and the slider  520  together, and more perferably, to the shaft  541  connected to the lower part of the link  530 . 
     When the link  530  is in a state parallel to the top of the body module  100  by rotating 90°, a considerably large force is needed to return the cover module  200  to its original position by turning the link  530  counterclockwise. Therefore, when the slide motion for opening of the cover module  200  is completed and the cover module  200  makes both the horizontal and vertical motion in the direction of opening the body module  100 , the link  530  preferably maintains a predetermined angle against the top of the body module  100 . In particular, it is preferable that the angle between the link  530  and the top of the body module  100  is an acute angle. More preferably, the angle between the link  530  and the top of the body module  100  is 30°. 
     If the link  530  were to be excessively turned, a shock to the body module  100  may be generated by the vertical motion of the cover module  200 . As a result, the cover module  200  and the body module  100  can be damaged. 
     In order for the link  530  to configure a predetermined angle with the body module  100  and to be prevented from being turned excessively or over a predetermined value, a first rotation preventing portion  140  is provided on the body module  100 . A second rotation preventing portion  250  is provided on the cover module  200  (see  FIGS. 11A to 11C ). 
     Optionally, either the first rotation preventing portion  140  or the second rotation preventing portion  250  can be provided. In order to sufficiently prevent the link  530  from being overturned, both of the first and second rotation preventing portions  140 ,  250  are preferably provided. 
     The first rotation preventing portion  140  includes a first vertical sill  140   a  provided vertically on the body module  100  and a first incline sill  140   b  configured to form a predetermined angle (e.g., 30°) against the body module  100 . The first vertical sill  140   a  of the first rotation preventing portion  140  is provided near a middle part of the body module  100  and prevents the link  530  from being overturned in case that the cover module  200  closes the body module  100 . The first incline sill  140   a  of the first rotation preventing portion  140  is formed in the vicinity of a periphery of the body module  100  and prevents the link  530  from being overturned in case that the cover module  200  opens the body module  100 . 
     The second rotation preventing portion  250  includes a second vertical sill  250   a  configured vertical on the cover module  200  and a second incline sill  250   b  formed to configure a predetermined angle (e.g., 30°) against the cover module  200 . The second rotation preventing portion  250  is formed in the vicinity of the shaft  542  connecting the link  530  and the cover module  200  together. Preferably, the second vertical sill  250   a  and the second incline sill  250   b , as shown in  FIG. 11A , are configured to enclose a circumference of the shaft  542 . 
     The second vertical sill  250   a  of the second rotation preventing portion  250  prevents the link  530  from being overturned in case that the cover module  200  closes the body module  100 . The second incline sill  250   b  of the second rotation preventing portion  250  prevents the link  530  from being overturned in case that the cover module  200  opens the body module  100 . 
     A process of a slide motion of the cover module  200  by the above-configured slide mechanism according to the present invention is explained. 
       FIGS. 11A to 11C  are side diagrams to explain a process of a sliding motion of a cover module using the slide mechanism shown in  FIG. 9A  and  FIG. 9B .  FIGS. 11A-1  to  11 C- 1  show the interaction of the link  530  with the rotation preventing portions  140  and  250 . 
     Referring to  FIG. 11A  and  FIG. 11B , if a user applies an external force to the cover module  200  to execute a function such as a calling and the like, the slider  320  and the link  530  move in a horizontal direction along the guide part  310 , whereby the cover module  200  moves in the horizontal direction. 
     Referring to  FIG. 11B  and  FIG. 11C , if the lower part of the cover module  200  is placed on the incline  130  of the body module  100 , and more particularly, if the link  530  comes into contact with the first incline sill  140   b , the link  530  is turned in an incline direction of the first incline sill  140   b . The elastic member  550  of the link  530  elastically returns in the incline direction of the first incline sill  140   b  to operate in the manner shown in  FIG. 11C . 
     Once one side of the turned link  530  adheres closely to the incline of the first incline sill  140   a , the other side of the link  530  comes into adhering to the second incline sill  250   a . Namely, the cover module  200  moves downward by the displacement amounting to the inclines of the first and second incline sills  140   a ,  250   b  against the body module  100 . 
     When the cover module  200  is made to return to the body module  100  after completion of using the terminal, a user pushes the cover module  200  in the direction of the body module  200 . In this case, a force enough to overcome the elastic force of the elastic member  550  should be applied. 
     If the elastic force of the elastic member  550  is overcome, the cover module  200  executes the above-explained process in a reverse order ( FIG. 11C  to  FIG. 11B ) to be located in the same manner shown in  FIG. 11A . Hence, the cover module  200  is mounted on the body module  100 . 
     Accordingly, the present invention provides several effects and advantages. 
     First, inclines mutually opposing each other are provided to middle parts of both the body and cover modules, respectively, and a slide mechanism is provided to enable the cover module to move along the inclines. As a result, a horizontal and vertical motion of the cover module is enabled. After completion of the slide motion of the cover module to execute a new function such as a calling function, the horizontal and vertical motion of the cover module is achieved to enable slimness of a mobile terminal. 
     Second, if a lower thickness of the body module is equal to an upper thickness of the cover module, an overall thickness of the mobile terminal becomes uniform after completion of the slide motion of the cover module. Hence, an exterior design of the mobile terminal is enhanced. 
     The invention thus being described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.