Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation application of application U.S. Ser. No. 12/109,626 filed in the United States on Apr. 25, 2008, and is related to and claims the benefit and the priority under 35 U.S.C. §119(a) of Korean Patent Application No. 10-2007-0058953, filed on Jun. 15, 2007 in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present general inventive concept relates to an image forming apparatus, and more particularly, to an image forming apparatus having an automatic document feeding unit so as to successively read documents. 
         [0004]    2. Description of the Related Art 
         [0005]    An image forming apparatus is an apparatus that prints an image on a printing medium, e.g., paper, according to an input image signal. An image forming apparatus is classified as a printer, a copying machine, a multi-function printer which has multiple functions of printing, copying and scanning, and the like. 
         [0006]    A conventional image forming apparatus includes an image reading unit to read image information recorded on a document, an image forming unit mounted under the image reading unit to form an image on a printing medium, e.g., paper, in response to image information read by the image reading unit or image information transferred from an external apparatus, e.g., a computer, and an automatic document feeding unit mounted above the image reading unit to enable the image reading unit to successively read documents. 
         [0007]    The image reading unit is pivotally coupled to an upper portion of the image forming unit to enable a user to perform maintenance work on internal devices of the image forming unit. Accordingly, the image reading unit can be rotated to expose a top of the image forming unit as needed. The automatic document feeding unit is pivotally coupled to an upper portion of the image reading unit to enable the image reading unit to read a pile of documents or thick documents. Accordingly, the automatic document feeding unit can be rotated to expose a top of the image reading unit as needed. 
         [0008]    However, in the above arrangement such that the image reading unit is pivotally coupled to the upper portion of the image forming unit and the automatic document feeding unit is pivotally coupled to the upper portion of the image reading unit, when exposing the top of the image forming unit by rotating the image reading unit to perform maintenance work on internal devices of the image forming unit, the automatic document feeding unit mounted above the image reading unit may unintentionally rotate by its own weight and collide with another object, for example, a wall of a building, against which the image forming apparatus is installed, thereby being damaged. 
       SUMMARY OF THE INVENTION 
       [0009]    The present general inventive concept provides an image forming apparatus that is capable of preventing a top of an image forming unit and a top of an image reading unit from being simultaneously exposed. 
         [0010]    Additional aspects and/or utilities of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept. 
         [0011]    The foregoing and/or other aspects and utilities of the present general inventive concept may be achieved by providing an image forming apparatus including an image forming unit to form an image on a printing medium, an image reading unit pivotally coupled to an upper portion of the image forming unit to expose and shield a top of the image forming unit, an automatic document feeding unit pivotally coupled to an upper portion of the image reading unit to expose and shield a top of the image reading unit, and a locking device to selectively expose any one of the top of the image forming unit and the top of the image reading unit. 
         [0012]    The locking device may include an up/down lever movably mounted on the image reading unit, and a first hook member rotatably mounted on the image reading unit, the first hook member rotating between a first position in which the first hook member is latched by the image forming unit and a second position in which the first hook member is released from the image forming unit by being pressed by the lever, where the automatic document feeding unit may be provided with a pressing protrusion to protrude downward to move the lever by pressing the lever. 
         [0013]    The first hook member may include a force transmitting portion to receive a force from a lower end of the lever to cause rotation of the first hook member, and a first latching portion latched by the image forming unit depending on a rotational angle of the first hook member. 
         [0014]    The locking device may include a first elastic member to move the lever away from the first hook member, and a second elastic member to return the first hook member to the first position. 
         [0015]    The lever may be provided with a mounting recess at a lower end thereof to supportingly receive an upper end of the first elastic member, and the image reading unit may be provided with a supporting part disposed thereon to support a lower end of the second elastic member. 
         [0016]    The mounting recess may have a lower portion opened sideward to permit the lower end of the lever to pass by the supporting part and to move downward. 
         [0017]    The locking device may include a second hook member rotatably mounted in the image reading unit. When the top of the image forming unit is exposed, the second hook member may be latched by contact with the pressing protrusion. 
         [0018]    The second hook member may be pivotally coupled to the image reading unit at a lower end thereof and may have a second latching portion at an upper end thereof, which is bent sideward to be latched by contact with the pressing protrusion, and the pressing protrusion may have a third latching portion at a lower end thereof, which is bent sideward to be latched to the second latching portion. 
         [0019]    The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing an image forming apparatus including an image forming unit to form an image on a printing medium, an image reading unit pivotally coupled to an upper portion of the image forming unit to expose and shield a top of the image forming unit, an automatic document feeding unit pivotally coupled to an upper portion of the image reading unit to expose and shield a top of the image reading unit, an up/down lever movably mounted on the image reading unit, and a locking device, where when the top of the image forming unit is exposed, the locking device fixedly attaches the automatic document feeding unit to the image reading unit, and when the top of the image reading unit is exposed, the locking device fixedly attaches the image reading unit to the image forming unit. 
         [0020]    The locking device may include a first hook member rotatably mounted on the image reading unit, the first hook member to rotate between a first position in which the first hook member is latched by the image forming unit and a second position in which the first hook member is released from the image forming unit by being rotated by contact with the lever, a pressing protrusion to protrude downward from the automatic document feeding unit to move the lever by pressing the lever, and a second hook member rotatably mounted on the image reading unit, the second hook member being latched by contact of the pressing protrusion when the top of the image forming unit is exposed. 
         [0021]    The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing an image forming apparatus, including an image forming unit, an image reading unit movably disposed on the image forming unit, a document reading unit movably disposed on the image reading unit, and a locking device to selectively couple the image reading unit to one of the image forming unit and the document reading unit. 
         [0022]    The locking device may include first and second latching members that are rotatably disposed on the image forming apparatus, and a sliding member to selectively fixedly attach the first latching member to the image forming unit and the second latching member to the automatic document reading unit. 
         [0023]    When the first latching member is in a latched state the second latching member may be in an unlatched state. 
         [0024]    When the first latching member is in an unlatched state the second latching member may be in a latched state. 
         [0025]    The first and second latching members may be rotatably disposed on the image reading unit. 
         [0026]    When a top of the image forming unit is exposed to outside of the image forming apparatus, the locking device fixedly attaches the image reading unit to the automatic document feeding unit. 
         [0027]    When a top of the image reading unit is exposed to outside of the image forming apparatus, the locking device fixedly attaches the image reading unit to the image forming unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]    These and/or other aspects and utilities of the exemplary embodiments of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, of which: 
           [0029]      FIG. 1  is a perspective view illustrating an image forming apparatus in accordance with the present general inventive concept; 
           [0030]      FIG. 2  is a perspective view illustrating a locking device of the image forming apparatus of  FIG. 1  in accordance with the present general inventive concept; 
           [0031]      FIG. 3  is a side view illustrating a state in which both a top of an image forming unit and a top of an image reading unit are shielded in the image forming apparatus of  FIG. 1  in accordance with the present general inventive concept; 
           [0032]      FIG. 4  is an enlarged view of a circular highlighted portion of  FIG. 2 ; 
           [0033]      FIG. 5  is a side view illustrating a state in which the top of the image reading unit is exposed in the image forming apparatus of  FIG. 1  in accordance with the present general inventive concept; 
           [0034]      FIG. 6  is an enlarged view of a circular highlighted portion of  FIG. 5 ; 
           [0035]      FIG. 7  is a side view illustrating a state in which the top of the image forming unit is exposed in the image forming apparatus of  FIG. 1  in accordance with the present general inventive concept; and 
           [0036]      FIG. 8  is an enlarged view of a circular highlighted portion of  FIG. 7 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0037]    Reference will now be made in detail to exemplary embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below to explain the present general inventive concept by referring to the figures. 
         [0038]    As illustrated in  FIG. 1 , an image forming apparatus  5  according to the present general inventive concept includes an image reading unit  10  to read an image recorded on a document, an image forming unit  20  to print an image on a printing medium, e.g., printing paper, in response to image information read by the image reading unit  10  or image information transferred from an external apparatus, e.g., a computer, and an automatic document feeding unit  30  to automatically feed documents so that the image reading unit  10  can successively read the documents. 
         [0039]    The image reading unit  10  is mounted above the image forming unit  20  for convenience in use, and the automatic document feeding unit  30  is mounted above the image reading unit  10  to enable the image reading unit  10  to successively read the documents. The image reading unit  10  is pivotally coupled to an upper portion of the image forming unit  20  at its rear end to enable a user to perform maintenance work on internal devices of the image forming unit  20 . Accordingly, the image reading unit  10  can be rotated upward to expose a top portion of the image forming unit  20 . The automatic document feeding unit  30  is pivotally coupled to an upper portion of the image reading unit  10  at its rear end to enable the image reading unit  10  to read a pile of documents, or thick documents, manually fed by a user, since the documents cannot be fed through the automatic document feeding unit  30 . Accordingly, the automatic document feeding unit  30  can be rotated upward to expose a top of the image reading unit  10 . 
         [0040]    As illustrated in  FIG. 2 , the image forming apparatus  5  according to the present general inventive concept may further include a locking device  40  to prevent the top of the image forming unit  20  and the top of the image reading unit  10  from being simultaneously exposed by selectively exposing any one of the top of the image forming unit  20  and the top of the image reading unit  10 . Both of the top of the image reading unit  10  and the top of the image forming unit  20  may not be simultaneously exposed to the outside of the image forming apparatus  5 . When the top of the image forming unit  20  is exposed, the locking device  40  fixedly attaches the automatic document feeding unit  30  to the image reading unit  10 . On the other hand, when the top of the image reading unit  10  is exposed, the locking device  40  fixedly attaches the image reading unit  10  to the image forming unit  20 . Accordingly, only any one of the top of the image forming unit  20  and the top of the image reading unit  10  is selectively exposed. 
         [0041]    When the automatic document feeding unit  30  moves with respect to one of the image reading unit  10  and the image forming unit  20 , the image reading unit  10  and the image forming unit  20  are coupled to each other so that the image reading unit  10  and the image forming unit  20  do not move with respect to each other. When the image reading unit  10  moves with respect to the image forming unit  20 , the image reading unit  10  and the automatic document feeding unit  30  are coupled to each other so that the image reading unit  10  and the automatic document feeding unit  30  do not move with respect to each other. 
         [0042]    As illustrated in  FIGS. 3 and 4 , the locking device  40  includes a lever  41  which is up/down movably mounted on the image reading unit  10 , a first hook member  42  rotatably mounted on the image reading unit  10 , and a guide member  43  to guide the up/down movement of the lever  41 . The first hook member  42  rotates between a first position in which the first hook member  42  is latched by the image forming unit  20  and a second position in which the first hook member  42  is released from the image forming unit  20  by being pressed by the down-moving lever  41 . The first hook member  42  includes a force transmitting portion  42   a  which receives a pressing force from a lower end  47  of the lever  41  to cause a downward rotation of the first hook member  42 , and a first latching portion  42   b  which is latched by the image forming unit  20  depending on a rotational angle of the first hook member  42 . 
         [0043]    The automatic document feeding unit  30  is provided with a pressing protrusion  31  which protrudes downward. When the automatic document feeding unit  30  covers the top of the image reading unit  10 , the pressing protrusion  31  presses downward on the lever  41  to move the lever  41  downward. The locking device  40  further includes a first elastic member  45 , which may be a spring, for example, and may be disposed internally within the lever  41  in a mounting recess  41   a,  and a second elastic member  46 , which may be a spring, for example, and may be attached to the force transmitting portion  42   a  of the first hook member  42 . When the automatic document feeding unit  30  is rotated upward such that the top of the image reading unit  10  is exposed, the down pressing force of the pressing protrusion  31  on the lever  41  is removed, and an elastic force of the first elastic member  45  causes the first elastic member  45  to return the lever  41  upward. When the lever  41  is returned upward by the elastic force of the first elastic member  45 , an elastic force of the second elastic member  46 , which may be attached to the force transmitting portion  42   a  of the first hook member  42 , causes the first hook member  42  to rotate upward to the first position, where the first hook member  42  is latched by the image forming unit  20  (referring to  FIG. 6 ). 
         [0044]    As described above, to install the first elastic member  45 , the lever  41  may be provided with an internal mounting recess  41   a  to supportingly receive an upper end of the first elastic member  45 , and a supporting part  11  to support a lower end of the first elastic member  45  may be protrudingly formed on a portion of the image reading unit  10 . A lower portion of the mounting recess  41   a  may be opened sideward so that the supporting part  11  can be inserted into the mounting recess  41   a.  Accordingly, the lower end of the lever  41  can pass by the supporting part  11  and press down the force transmitting portion  42   a  of the first hook member  42  mounted below the supporting part  11 . 
         [0045]    The locking device  40  may further include a second hook member  44  rotatably mounted on a portion of the image reading unit  10 . When the image reading unit  10  is rotated upward and the top of the image forming unit  20  is exposed, the second hook member  44  rotates toward the pressing protrusion  31  to be latched by the pressing protrusion  31  (referring to  FIG. 8 ). The second hook member  44  may be pivotally coupled to a portion of the image reading unit  10  at its lower end. In order for the second hook member  44  to be latched by the pressing protrusion  31 , the second hook member  44  has a second latching portion  44   a  at its upper end, which is bent sideward to be latched by the pressing protrusion  31 . The pressing protrusion  31  has a third latching portion  31   a  disposed at its lower end, which is bent sideward to receive and to be latched by the second latching portion  44   a  of the second hook member  44 . 
         [0046]    Accordingly, while the top of the image reading unit  10  is unexposed and covered with the automatic document feeding unit  30 , the lever  41  is kept in a state of being compressed and is moved down by the pressing protrusion  31 , and the first hook member  42  is kept in a state of being rotated and released from the image forming unit  20 , so that the top of the image forming unit  20  can be exposed by rotating the image reading unit  10 . When the top of the image reading unit  10  is exposed by rotating the automatic document feeding unit  30  upward as illustrated in  FIG. 5 , the lever  41  is returned upward by an elastic force of the first elastic member  45  as illustrated in  FIG. 6 , the first hook member  42  is returned to its original position by being rotated upward by the second elastic member  46 , and the first latching portion  42   b  of the first hook member  42  is latched by the image forming unit  20 , thereby fixedly attaching the image reading unit  10  to the image forming unit  20 . As described above, when the top of the image reading unit  10  is exposed, the locking device  40  according to the present general inventive concept fixedly attaches the image reading unit  10  to the image forming unit  20 . 
         [0047]    If rotating the image reading unit  10  to expose the top of the image forming unit  20  as illustrated in  FIG. 7 , the second hook member  44  rotates on the lower end by its own weight as illustrated in  FIG. 8 , and the second latching portion  44   a  provided at the upper end of the second hook member  44  is latched by the third latching portion  31  a of the pressing protrusion  31  introduced into the image reading unit  10 , thereby fixedly attaching the automatic document feeding unit  30  to the image reading unit  10  through the action of the pressing protrusion  31 . As described above, when the top of the image forming unit  20  is exposed, the locking device  40  according to the present general inventive concept fixedly attaches the automatic document feeding unit  30  to the image reading unit  10 . 
         [0048]    As apparent from the above description, the image forming apparatus according to the present general inventive concept, can prevent both the top of the image forming unit and the top of the image reading unit from being simultaneously exposed by the locking device, which is capable of selectively exposing any one of the top of the image forming unit and the top of the image reading unit. Accordingly, the automatic document feeding unit can be prevented from being damaged due to the simultaneous exposure of the top of the image forming unit and the top of the image reading unit. 
         [0049]    Although embodiments of the present general inventive concept have been illustrated and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.

Technology Category: h