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CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit under 35 U.S.C. §119(a) of Korean Patent Application No. 2005-125570 filed on Dec. 19, 2005, in the Korean Intellectual Property Office, the entire disclosure of which is hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a mobile apparatus. More particularly, the present invention relates to a smaller, simpler hinge device, and a mobile apparatus having the same. 
         [0004]    2. Description of the Related Art 
         [0005]    A mobile apparatus such as a mobile phone or a camcorder has a display part that can rotate away from a main body. Accordingly, a user opens the display part of the mobile apparatus and moves the display part away from the main body by a predetermined distance to adjust a rotation angle of the display part. To do so, the display part of the mobile apparatus is hinged to the main body. 
         [0006]      FIG. 1  illustrates an example of a conventional rotatable hinge device. Referring to  FIG. 1 , a conventional rotatable hinge device  10  comprises a main bracket  11  having a hinge unit  18 , a shaft  12  rotatably engaged with a penetrating opening  11   a  of the main bracket  11 , a pair of cams  13  and  14  that fit over the shaft  12  and restrain rotation of the main bracket  11 , and an elastic member  15  disposed between the pair of cams  13  and  14  and the penetrating opening  11   a  to press the main bracket  11 . A detector  16  may be formed above the cam  13  to operate a rotating angle sensing switch (not shown). A fixing member  17  is fixed under the shaft  12 , and the elastic member  15  may include a spring washer. The pair of cams  13  and  14  comprise a lower cam  14  having a protrusion  14   a  to form the sense of a click when rotating, and an upper cam  13  having a recess  13   a  to receive the protrusion  14   a.  Accordingly, when the rotatable hinge device  10  rotates, the lower cam  14  and the upper cam  13  are placed into friction contact with each other so that the hinge implements a free stop movement, and the protrusion  14   a  of the lower cam  14  and the recess  13   a  of the upper cam  13  impart the feeling of a click. The phrase free stop movement refers to the ability to stop at an arbitrary rotational angle, and hereinafter will be referred to as a free stop. 
         [0007]      FIG. 2  is a front view of the rotatable hinge device when the rotatable hinge device is engaged with a mobile apparatus. As shown in  FIG. 2 , the rotatable hinge device  10  having the fixing member  17  of the shaft  12  engaged with the display part  2  is connected to the main body  3  of the mobile apparatus by a hinge unit  18  of the main bracket  11 . 
         [0008]      FIGS. 3A and 3B  are views of an upright camcorder  1  with the rotatable hinge device  10 .  FIG. 3A  shows the display part  2  closed, and  FIG. 3B  shows the display part  2  opened. 
         [0009]    Referring to  FIGS. 3A and 3B , the display part  2  of the upright camcorder  1  can be rotated about an X axis of  FIG. 3B  by the rotatable hinge device  10  so that the display part  2  can be opened from the main body  3 . When opened, the display part  2  can be rotated about a Z axis of an X-Y plane of  FIG. 3B , that is, from the main body  3 , by the shaft  12 . Accordingly, a user rotates the display part  2  to adjust an angle of a screen when the display part  2  is opened from the main body  3 . The upright camcorder  1  observes a subject using the display part  2  such as a liquid crystal display (LCD) instead of a general viewfinder. 
         [0010]    The conventional rotatable hinge device  10  has relatively large-sized parts, such as the main bracket, so it occupies a large space in the mobile apparatus. Compact mobile apparatuses, such as an upright camcorder that uses a hard drive or flash memory, requires a more compact hinge device in comparison with a mobile apparatus that uses a deck unit and a magnetic recording medium. Additionally, part of the conventional hinge device is exposed to the outside by an installation line L 1 . This interferes with the aesthetics of the mobile apparatus. 
         [0011]    Accordingly, there is a need for a more compact hinge device for a mobile apparatus. 
       SUMMARY OF THE INVENTION 
       [0012]    An aspect of the present invention is to address at least the above problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide an improved hinge device that can be installed in a smaller area in comparison with a conventional rotatable hinge device. 
         [0013]    Another aspect of the present invention is to provide a hinge device which does not reveal an installation line when installed in a mobile apparatus so that the mobile apparatus has a more refined design. 
         [0014]    Yet another aspect of the present invention is to provide a mobile apparatus having the hinge device. 
         [0015]    In accordance with an aspect of the present invention, a hinge device includes a sliding unit that slides with respect to a main body of a mobile apparatus; and a rotary unit disposed on the sliding unit to rotatably engage a display part of a mobile apparatus. 
         [0016]    The sliding unit may include a sliding body, and a first connection portion to engage the sliding body with the main body. 
         [0017]    The sliding body may be curved. 
         [0018]    The sliding body may include a first connection opening to receive the first connection portion, and a second connection opening to receive the rotary unit. 
         [0019]    The rotary unit may include a rotary body engaging the display part, a first rotary shaft formed in the rotary body to be inserted in the second connection opening, a cam formed at the first rotary shaft to control a rotating of the rotary body, and a second elastic member formed in the first rotary shaft to press the cam. 
         [0020]    The rotary body according to an exemplary embodiment of the present invention may include a fixing member to fix the display part. 
         [0021]    The rotary body according to another exemplary embodiment of the present invention may include a second connection portion to rotatably engage the display part. 
         [0022]    The second connection portion may include a third elastic member inserted in an axial opening formed on the rotary body, and second rotary shafts elastically supported at opposite ends of the third elastic member to protrude outside the rotary body. 
         [0023]    The cam may include a first cam having a protrusion, and a second cam having a protrusion receiving recess corresponding to the protrusion. 
         [0024]    The rotary unit may further include a detector to sense a rotational angle of the first rotary shaft. 
         [0025]    The first connection portion may protrude from the sliding body. 
         [0026]    The first connection portion may include a first elastic member inserted in the first connection opening, and guide protrusions elastically supported at opposite ends of the first elastic member to protrude outside the sliding body. 
         [0027]    The guide protrusions may slide along a guide recess formed in the main body. 
         [0028]    In accordance with another aspect of the present invention, a mobile apparatus includes a main body, a display part, and a hinge device to slidingly open and close the display part with respect to the main body. 
         [0029]    The hinge device may slidingly open and close the display part and then allow the display part to rotate. 
         [0030]    The hinge device may include a sliding unit that slides with respect to a main body of a mobile apparatus; and a rotary unit disposed on the sliding unit to rotatably engage a display part of a mobile apparatus. 
         [0031]    The sliding unit may include a sliding body, and a first connection portion to engage the sliding body with the main body. 
         [0032]    The sliding body may be curved. 
         [0033]    The sliding body may include a first connection opening to receive the first connection portion, and a second connection opening to receive the rotary unit. 
         [0034]    The rotary unit may include a rotary body engaging the display part, a first rotary shaft formed in the rotary body to be inserted in the second connection opening, a cam formed at the first rotary shaft to control a rotating of the rotary body, and a second elastic member formed in the first rotary shaft to press the cam. 
         [0035]    The rotary body according to an exemplary embodiment of the present invention may include a fixing member to fix the display part. 
         [0036]    The rotary body according to another exemplary embodiment of the present invention may include a second connection portion to rotatably engage the display part. 
         [0037]    The second connection portion may include a third elastic member inserted in an axial opening formed on the rotary body, and second rotary shafts elastically supported at opposite ends of the third elastic member to protrude outside the rotary body. 
         [0038]    The cam may include a first cam having a protrusion, and a second cam having a protrusion receiving recess corresponding to the protrusion. 
         [0039]    The rotary unit may further include a detector to sense a rotational angle of the first rotary shaft. 
         [0040]    The first connection portion may protrude from the sliding body. 
         [0041]    The first connection portion may include a first elastic member inserted in the first connection opening, and guide protrusions elastically supported at opposite ends of the first elastic member to protrude outside the sliding body. 
         [0042]    The guide protrusions may slide along a guide recess formed in the main body. 
         [0043]    The rotary unit may further include a detector to sense a rotating angle of the first rotary shaft. 
         [0044]    The hinge device may be formed at an edge inside the display part. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0045]    The above and other objects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: 
           [0046]      FIG. 1  is a perspective view of a conventional hinge device; 
           [0047]      FIG. 2  is a front view of the hinge device of  FIG. 1  when installed in a mobile apparatus; 
           [0048]      FIG. 3A  is a perspective view of an upright camcorder having the hinge device of  FIG. 1  with the display part closed; 
           [0049]      FIG. 3A  is a perspective view of an upright camcorder having the hinge device of  FIG. 1  with the display part opened; 
           [0050]      FIG. 4A  is a front view of a hinge device according to a first exemplary embodiment of the present invention; 
           [0051]      FIG. 4B  is a side view of the hinge device of  FIG. 4A ; 
           [0052]      FIG. 5  is an exploded perspective view illustrating the hinge device of  FIGS. 4A and 4B ; 
           [0053]      FIG. 6  is a perspective view of the exterior of an upright camcorder having the hinge device of  FIGS. 4A and 4B ; 
           [0054]      FIG. 7A through 7E  are views illustrating the operation of an upright camcorder having a hinge device according to a first exemplary embodiment of the present invention; 
           [0055]      FIG. 8  is an exploded perspective view illustrating a hinge device according to a second exemplary embodiment of the present invention; and 
           [0056]      FIGS. 9A and 9B  are views illustrating the operation of an upright camcorder having a hinge device according to a second exemplary embodiment of the present invention. 
       
    
    
       [0057]    Throughout the drawings, the same reference numerals will be understood to refer to the same elements, features, and structures. 
       DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0058]    The matters defined in the description such as a detailed construction and elements are provided to assist in a comprehensive understanding of the embodiments of the invention. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness. 
         [0059]      FIG. 4A  is a front view of a hinge device according to a first exemplary embodiment of the present invention,  FIG. 4B  is a side view of the hinge device of  FIG. 4A , and  FIG. 5  is an exploded perspective view of the hinge device of  FIG. 4A . 
         [0060]    Referring to  FIGS. 4A ,  4 B, and  5 , a hinge device  100  according to the first exemplary embodiment of the present invention comprises a sliding unit  110  and a rotary unit  120 . 
         [0061]    The sliding unit  110  comprises a sliding body  113  with a certain curvature and a first connection portion  111  to engage the sliding body  113  with a main body of a mobile apparatus. 
         [0062]    A first connection opening  114  is disposed at a first end of the sliding body  113  and a second connection opening  115  is disposed at a second end of the sliding body  113 . The second connection opening  115  is substantially perpendicular to the first connection opening  114 . The first connection opening  114  receives the first connection portion  111 , and the second connection opening  115  receives the rotary unit  120 . Because the sliding body  113  has a certain curvature, a display part  102  engaged with the sliding body  113  can be opened and closed along the curved passage from a main body  103 . Additionally, the sliding body  113  is slid along a guide recess  104  formed in the main body  103  so as to be hidden in the main body  103 . The curvature of the sliding body  113  can be arbitrarily set depending on the size or specification of a product. 
         [0063]    The first connection portion  111  comprises a first elastic member  112  inserted in the first connection opening  114 , and a pair of guide protrusions  111   a  and  111   b.  Opposite ends of the first elastic member  112  have a first guide protrusion  111   a  and a second guide protrusion  111   b,  respectively. The first and the second guide protrusions  111   a  and  111   b  protrude to the outside of the sliding body  113 . The pair of guide protrusions  111   a  and  111   b  may have round or hemispherical surfaces. For example, the pair of guide protrusions  111   a  and  111   b  may be round balls or round rods. The pair of guide protrusions  111   a  and  111   b  each may have engagement protrusions  111   a ′ and  111   b ′ which face inward into the first connection opening  114  so as to be connected with the first elastic member  112 . The first elastic member  112  fits over each engagement protrusion  111   a ′ and  111   b ′ of the pair of guide protrusions  111   a  and  111   b  to push the pair of guide protrusions  111   a  and  111   b  outward. Therefore, when the pair of guide protrusions  111   a  and  11   b  are slid along the guide recess  104  inside of the main body  103 , the display part  102  engaged with the sliding body  113  can be arbitrarily stopped at any desired angle. In other words, a free stop can be implemented. The first connection portion  111  may be provided in various forms if the sliding body  113  is guided along the guide recess  104  to perform a free stop movement. One of the features of the hinge device  100  according to the first exemplary embodiment of the present invention is that the display part  102  is engaged by the sliding body  113 . 
         [0064]    The rotary unit  120  comprises a rotary body  121 , a first rotary shaft  122 , a second elastic member  123  and a pair of cams  124  and  125 . 
         [0065]    The rotary body  121  extends from the first rotary shaft  122  toward the display part  102  to engage with the display part  102 . In the hinge device  100  according to the first exemplary embodiment of the present invention, the rotary body  121  engages the display part  102  by a fixing member  127 . In a hinge device  200  (refer to  FIG. 8 ) according to a second exemplary embodiment of the present invention, which will be explained later, a rotary body  221  engages a display part  202  by a second connection portion  230 . In the hinge device  100  according to the first exemplary embodiment of the present invention, the fixing member  127  is inserted in a fixing recess (not shown) of the display part  102  so as to engage the rotary body  121  with the display part  102 . The fixing member  127  may extend from a center of the rotary body  121  as a single member. Or, a separate axial opening may be formed on a central portion of the rotary body  121  and a bar shaped fixing member  127  may be inserted in the opening. Regardless of the shape, the fixing member  127  has a fixing protrusion  127   a  so that the rotary body  121  does not separately rotate about the first rotary shaft  122 . 
         [0066]    The first rotary shaft  122  is rotatably engaged with a sliding unit  110 , more specifically, the second connection opening  115  of the sliding body  113 . Screw threads are formed at one end of the first rotary shaft  122 , and the second elastic member  123  and the pair of cams  124  and  125  are sequentially engaged with the first rotary shaft  122 . Although not shown, a separate cap is fastened with the screw threads of the first rotary shaft  122  to restrain the second elastic member  123  and the pair of cams  124  and  125 . The first rotary shaft  122  and the rotary body  121  may be integrally formed. The first rotary shaft  122  may further include a detector  126 . The detector  126  is disposed above the pair of cams  124  and  125  to operate a rotary angle sensing switch (not shown) of the first rotary shaft  122 . 
         [0067]    The second elastic member  123  fits over the first rotary shaft  122  to press the pair of cams  124  and  125 . The second elastic member  123  may include a spring washer. 
         [0068]    The pair of cams  124  and  125  engage the second elastic member  123  of the first rotary shaft  122 . The pair of cams  124  and  125  control rotation of the rotary body  121 . The pair of cams  124  and  125  comprise a first cam  124  having a protrusion  124   a,  and a second cam  125  having a protrusion receiving recess  125   a  corresponding to the protrusion  124   a.  The pair of cams  124  and  125  generate the sense of a click when the first rotary shaft  122  rotates. Accordingly, when the first rotary shaft  122  rotates, the second elastic member  123  presses the first cam  124  and the second cam  125  together to generate friction so that a free stop rotary movement can be implemented and so that the protrusion receiving recess  125   a  of the second cam  125  and the protrusion  124   a  of the first cam  124  generate the sense of a click. 
         [0069]    The above configuration of the rotary unit  120  should not be considered as limiting. The configuration of the rotary unit  120  according to the first exemplary embodiment of the present invention may be varied if the display part  102  can be rotated based on 2 axes. 
         [0070]    The mobile apparatus  101  having the hinge device  100  according to the first exemplary embodiment of the present invention comprises the main body  103 , the display part  102 , which can output image information from the main body  103 , and the hinge device  100 . 
         [0071]    The guide recess  104  is formed in the main body  103  for accommodating the hinge device  100  so that it may slide. The shape of the curved guide recess  104  corresponds to the shape of the sliding body  113 . Accordingly, the hinge device  100  allows the display part  102  to be opened and closed along the guide recess  104  with respect to the main body  103 . Additionally, the hinge device  100  is engaged by the sliding body  113  and slides along the guide recess  104  so that the space required by the hinge device  100  can be significantly reduced. 
         [0072]    The mobile apparatus  101  according to the first exemplary embodiment of the present invention may have the hinge device  100  on an inner surface of a top end of the display part  102 . If formed on the inner surface of the display part  102 , the hinge device  100  is hidden from the exterior of the display part  102 . 
         [0073]      FIG. 6  is a view of the exterior of an exemplary mobile apparatus (an upright camcorder) having the hinge device according to the first exemplary embodiment of the present invention. As shown in  FIG. 6 , the mobile apparatus  101  having the hinge device  100  according to the first exemplary embodiment of the present invention has no line at a portion where the hinge device  100  is installed and only an exterior line L 2  at the top end of the display part  102  so that a more refined design is possible. 
         [0074]    The operation of the mobile apparatus having the hinge device according to the first exemplary embodiment of the present invention will now be described with reference to the accompanying drawings. 
         [0075]      FIGS. 7A through 7E  illustrate the operation of an upright camcorder, which is a representative example of a mobile apparatus, having the hinge device according to the first exemplary embodiment of the present invention. As shown in  FIGS. 7A through 7E , the hinge device  100  is engaged with one end of the upper portion of the display part  102  of the upright camcorder  101 . 
         [0076]    First, as shown in  FIGS. 4A and 7A , in the upright camcorder  101  according to the first exemplary embodiment of the present invention, the sliding body  113  of the hinge device  100  is slid along the guide recess  104  of the main body  103  to open and close the display part  102 . During this movement, the display part  102  may perform a free stop at any desired angle, as shown in dotted lines of  FIG. 7A   
         [0077]    Additionally, regardless of the degree to which the sliding body  113  is opened and closed, the display part  102  can be rotated on an X-Y plane from the sliding body  113 , that is, rotated about a Z axis, by the rotary unit  120 , as shown in  FIG. 7B . 
         [0078]      FIG. 7C  illustrates a moving image photographing mode of the upright camcorder  101 . This mode is convenient for a user to photographing a moving image while holding the upright camcorder  101  in the user&#39;s hands and viewing the display part  102 . 
         [0079]    While in the moving image photographing mode of  FIG. 7C , the sliding body  113  may be slid into the main body  103 , as illustrated in  FIG. 7D . When the sliding body  113  is slid into the main body  103 , the upright camcorder  101  moves into the position shown in  FIG. 7E .  FIG. 7E  illustrates a still image photographing mode. This mode is convenient for photographing a still image or reproducing and viewing still images. The mode of  FIG. 7E  provides a landscape mode, and is also suitable for watching digital multimedia broadcasting (DMB). 
         [0080]    As described above, the mobile apparatus according to the first exemplary embodiment of the present invention has a display part that can be freely, smoothly, and conveniently operated. 
         [0081]      FIG. 8  is an exploded perspective view of a hinge device according to a second exemplary embodiment of the present invention. 
         [0082]    Referring to  FIG. 8 , the hinge device  200  according to the second exemplary embodiment of the present invention has a structure in which the rotary body  221  of the rotary unit  220  is engaged with the display part  202  by a second connection portion  230  as briefly described above. The second connection portion  230  of the rotary body  221  according to the second exemplary embodiment of the present invention may have the same structure as the first connection portion  111  according to the first exemplary embodiment of the present invention. 
         [0083]    In detail, the second connection portion  230  comprises a third elastic member  232  and a pair of second rotary shafts  231  and  233 . The pair of second rotary shafts  231  and  233  protrude to the outside of the rotary body  221 . The surfaces of the pair of second rotary shafts  231  and  233  may be round or hemispherical. For example, the pair of second rotary shafts  231  and  233  may be round balls or round rods. The pair of second rotary shafts  231  and  233  each may have engagement protrusions  231 ′ and  233 ′ which extend inward into an axial opening  221   a  so as to be connected with the third elastic member  232 . The third elastic member  232  fits over each of the engagement protrusions  231 ′ and  233 ′ of the pair of second rotary shafts  231  and  233  to push the pair of second rotary shafts  231  and  233  outward. Accordingly, the pair of second rotary shafts  231  and  233  allow the display part  102  to arbitrarily stop at a desired angle, that is, a free stop can be implemented. For a more effective free stop function, the display part  202  has hemispheric recesses that correspond to the engagement protrusions  231 ′ and  233 ′ of the second rotary shafts  231  and  233  of the hinge device  200  according to the second exemplary embodiment of the present invention. 
         [0084]    The remaining portions of the hinge device  200  are substantially the same as the hinge device  100  according to the first embodiment of the invention. Therefore, a detailed description of these portions will not be repeated for conciseness. 
         [0085]      FIGS. 9A and 9B  are views illustrating the operation of an upright camcorder having the hinge device  200  according to the second exemplary embodiment of the present invention. Referring to  FIGS. 9A and 9B , the hinge device  200  according to the second exemplary embodiment of the present invention is engaged with one end of an upper portion of the display part  202  of the upright camcorder  201 . 
         [0086]    The upright camcorder  201  according to the second exemplary embodiment of the present invention can be rotated about an X axis by the sliding body  213 . Specifically, even when the sliding body  213  is not slid into a main body  203 , the upright camcorder  201  according to the second exemplary embodiment of the present invention can directly translate from the moving image photographing mode of  FIG. 9A  into the landscape mode of  FIG. 9B  by rotation of the second connection member  230 . 
         [0087]    The hinge device according to the exemplary embodiments of the present invention can be installed in a smaller space than a conventional rotatable hinge device so that the mobile apparatus may be more compact. 
         [0088]    Further, a mobile apparatus having the hinge device according to exemplary embodiments of the present invention has no line for engaging the hinge device so that it has a more refined design in comparison with a conventional mobile apparatus. 
         [0089]    While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Summary:
A mobile apparatus includes a main body, a display part, and a hinge device. The hinge device opens and closes the display part from the main body and allows the display part to rotate. The hinge device includes a sliding unit that slides with respect to the main body, and a rotary unit rotatably formed with the sliding unit to engage the display part. The hinge device requires less installation space so that the mobile apparatus may be more compact. Furthermore, there is no visible installation line of the hinge device so that the mobile apparatus may have a more refined design.