Abstract:
A developing unit includes a developer cartridge containing developer and a developing cartridge with a developing cartridge body comprising a mounting portion and a cover member. The mounting portion accepts the developer cartridge for replenishing developer consumed by the developing cartridge. The cover member closes an opening of the mounting portion when the developer cartridge is not inserted into the mounting portion. When a developing unit is initially constructed, printing is performed using developer contained in the developing unit. A developer cartridge containing developer can be inserted into the developing unit, allowing the supply of developer in the developing unit to be replenished.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from Korean Patent Application No. 10-2008-0016467, filed on Feb. 22, 2008, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to an image forming apparatus, and more particularly, to a configuration of developing unit of an image forming apparatus. 
         [0004]    2. Description of the Related Art 
         [0005]    Developing units employed in compact image forming apparatuses such as laser printers may include an internal space for housing developer, a photosensitive medium, a developer supply unit for supplying developer and a waste developer collecting portion for collecting remaining developer, all of which are integrated as a single cartridge. 
         [0006]    Due to such integration, despite the fact that the other components of the developing unit, e.g., photosensitive media and developer supply units, may have considerable remaining useful life, when developer is completely exhausted, a user needs to replace the entire developing unit with a new one at least in part due to the difficulties in only replenishing the developer by the user. 
         [0007]    To avoid the cost of new developing unit, users may attempt to refill a used developing unit with additional supply of developer or to purchase from so called recycling vendors a used developing unit that has been refilled with developer. However, these refilling attempts are generally inadequate, as they are messy and may result in damage or reduced performance of the developing units if developer of inferior quality is used as replenishment. 
         [0008]    Researches are on-going among the manufacturers of image forming apparatus to provide ways in which to allow replenishment of genuine quality developer by the users. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Various features and advantages of the disclosure will become more apparent by the following detailed description of several embodiments thereof with reference to the attached drawings, of which: 
           [0010]      FIG. 1  is a perspective view of a developing unit of an image forming apparatus according to an embodiment of the invention; 
           [0011]      FIGS. 2 and 3  are plane views of a cover member according to an embodiment of the invention; 
           [0012]      FIG. 4  is a cross-sectional view of a developing cartridge from which a cover member is removed, according to an embodiment of the invention; 
           [0013]      FIG. 5  is a cross-sectional view of a developing cartridge in which a cover member is mounted, according to an embodiment of the invention; 
           [0014]      FIG. 6  is a perspective view of a developing cartridge in which a cover member is mounted, according to an embodiment of the invention; and 
           [0015]      FIG. 7  is a perspective view of a developing unit from which a cover member is removed and to which a developer cartridge is attached, according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0016]    In the following description, the same drawing reference numerals are used for the same elements in all drawings. The matters defined in the description, such as detailed construction and elements, are provided to assist in a comprehensive understanding of the invention. Thus, it should be apparent that the exemplary embodiments of the invention can be carried out without those specifically detailed matters. Also, well-known functions or constructions are not described in detail so as to avoid obscuring the description with unnecessary detail. 
         [0017]    Referring to  FIG. 1 , a developing cartridge  100  according to an embodiment of the invention may include a cartridge body  110 , a handle  120  and a mounting portion  130 . The mounting portion  130  may be closed by a cover member  10 . Reference numeral  117  denotes a waste developer outlet shutter unit, which is described in detail below. 
         [0018]    The handle  120  may be pivotably mounted on the cartridge body  110 . The handle  120  allows a user to attach or detach the cartridge body  110  to or from an image forming apparatus. 
         [0019]    The mounting portion  130  has an opening on one side of the cartridge body  110 , so that a developer cartridge  200  (see  FIG. 7 ) which houses developer may be mounted in the mounting portion  130 . 
         [0020]    Referring to  FIG. 4 , the cartridge body  110  includes a photosensitive medium  111  and a developer supply unit  112  which contains developer T used for printing. The developer cartridge  200  may supply additional developer when the developer contained in the developer supply unit  112  is exhausted or when additional supply of developer is required. 
         [0021]    The mounting portion  130  may include mounting guides  131  and  132 . The mounting guides  131  and  132  may be formed on sides of the mounting portion  130  and may have concave and convex surfaces to guide the developer cartridge  200  into the mounting portion  130 . As shown in  FIG. 7 , in one embodiment of the invention, the developer cartridge  200  may include guide traveling units  211  and  212  which correspond to the mounting guides  131  and  132  of the mounting portion  130 , respectively, so that the developer cartridge  200  may be smoothly mounted in the mounting portion  130 . 
         [0022]    Referring to  FIGS. 1 and 6 , the cover member  10  may be slidingly inserted or otherwise detachably inserted into the mounting portion  130  to seal the opening of the mounting portion  130 . Referring to  FIGS. 2 and 3 , the cover member  10  includes a cover member body  11 , a shutter unit  17  and a locking unit  18  (see  FIG. 1 ). 
         [0023]    Referring to  FIG. 5 , the cover member body  11  is configured in the form of a box enclosing a space to house a waste developer collecting portion  14 , and has a shape corresponding to the opening of the mounting portion  130  (see  FIG. 1 ). Additionally, the cover member body  11  includes a waste developer inlet  12  which is formed on a surface thereof and through which waste developer generated as a result of printing using the developing cartridge  100  enters. A waste developer outlet  115  is formed on a surface of the cartridge body  110  opposite the waste developer inlet  12  of the cover member body  11 . 
         [0024]    Referring to  FIGS. 2 and 3 , the shutter unit  17  includes a sliding shutter  15  and an elastic member  16 . When the cover member  10  is mounted in the developing cartridge  100 , the sliding shutter  15  slides to an open position while one end of the sliding shutter  15  is blocked by the cartridge body  110 , as shown in  FIG. 3 . The elastic member  16  elastically supports the sliding shutter  15  so that the sliding shutter  15  slides to a closed position in which the waste developer inlet  12  is sealed. According to the supporting operation of the elastic member  16 , the sliding shutter  15  causes the waste developer inlet  12  to open when the cover member  10  is attached to the cartridge body  110  as shown in  FIGS. 3 and 6 . If the cover member  10  is separated from the cartridge body  110 , as shown in  FIG. 1 , the sliding shutter  15  closes the waste developer inlet  12  as shown in  FIGS. 1 and 2 . 
         [0025]    Referring to  FIG. 7 , a developing unit  300  according to an embodiment may include the developing cartridge  100  and the developer cartridge  200  is inserted into the mounting portion  130 , which is exposed when the cover member  10  closing the opening of the developing cartridge  100  (see  FIG. 6 ) is removed from the cartridge body  110 . The developer cartridge  200  supplies developer to the developer supply unit  112  (see  FIG. 4 ). 
         [0026]    Hereinafter, an operation of the developing unit  300  of the image forming apparatus according to an embodiment of the invention will be described. 
         [0027]    As shown in  FIG. 4 , the photosensitive medium  111  and developer supply unit  112  are disposed inside the cartridge body  110  of the developing cartridge  100 , and the developer supply unit  112  contains developer T. A user may use the developing cartridge  100  until the developer T is substantially exhausted, although it should be understood that the developing cartridge  100  may be replenished using the developer cartridge  200  even before the developer T is completely exhausted. 
         [0028]    The mounting portion  130  is disposed inside the cartridge body  110  to receive the developer cartridge  200  (see  FIG. 7 ), from which replenishment of the developer that had been consumed by the developer supply unit  112  may be made. The mounting portion  130  may be sealed by the cover member  10 , in order, e.g., to prevent external dust or dirt from being drawn therein, for example, when the developing cartridge  100  is initially manufactured, as shown in  FIGS. 1 and 6 , or during when the developing cartridge  100  is operated without a developer cartridge  200  installed by using the developer available in the developer supply unit  112 . 
         [0029]    Referring to  FIG. 5 , the cover member  10  acts to close the mounting portion  130  (see  FIG. 6 ). Additionally, in one embodiment of the invention, the cover member  10  may include the waste developer collecting portion  14  disposed therein to collect waste developer W generated during printing operations. The waste developer W is conveyed to the waste developer outlet port  115  through a waste developer conveying unit  113 , and is then collected in the waste developer collecting portion  14  via the waste developer inlet  12 . The waste developer outlet port  115  may be opened by the outlet port shutter unit  117  (see  FIG. 1 ) when the developing cartridge  100  is installed in an image forming apparatus (not shown), so as to fluidly communicate with the waste developer inlet  12 . 
         [0030]    When the developer in the developer supply unit  112  is substantially exhausted, a user removes the developing cartridge  100  from the image forming apparatus (not shown) by gripping the handle  120 . Subsequently, the user operates the locking unit  18  of the cover member  10  to release the locking state, so that the cover member  10  is removed from the cartridge body  110 . 
         [0031]    As shown in  FIG. 7 , since the mounting portion  130  is accessible once the cover member  10  is removed, the user may insert the developer cartridge  200  into the mounting portion  130 . When the developer cartridge  200  is mounted in the cartridge body  110 , a developer contained in the developer cartridge  200  can be supplied to the developer supply unit  112  via a developer discharge port (not shown) provided between the developer cartridge  200  and the developer supply unit  112 . 
         [0032]    The foregoing embodiments and advantages are merely examples and are not to be construed as limiting the present invention. The present teaching can be readily applied to various other embodiments. Also, the description of the embodiments of the present invention is intended to be illustrative, and not to limit the scope of the claims, and many alternatives, modifications, and variations will be apparent to those skilled in the art.