Patent Publication Number: US-7218868-B2

Title: Image forming apparatus having locking/releasing unit

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the priority of Korean Patent Application No. 2003-76702, filed Oct. 31, 2003 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention generally relates to an image forming apparatus, and more specifically, to an image forming apparatus having a checking unit to check whether a transferring unit is mounted therein by a locking/releasing unit. 
   2. Description of the Related Art 
   Generally, an image forming apparatus such as a printer or a copier has a photoconductive unit on which an image is formed, a transferring unit to transfer the image from the photoconductive unit onto a paper, and a fixing means to fix at least any one of the photoconductive unit and the transferring unit into the image forming apparatus. 
   However, a user may inadvertently close a cover of a main body of the image forming apparatus to print an image on a recording medium, such as a paper, while the transferring unit is not completely connected with the photoconductive unit or the image forming apparatus. 
   At this time, as the transferring unit does not accurately make contact with the photoconductive unit, the image formed on the photoconductive unit is not completely transferred to the transferring unit. Thus, it becomes hard to print a desired image having a high quality. 
   In addition, as the transferring unit is not completely secured in the image forming apparatus during the operation, troubles may occur to the image forming apparatus and the transferring unit due to the shaking of a transfer belt while rotating and being disposed in the transferring unit. 
   Accordingly, it is required to provide an image forming apparatus capable of notifying the user that the image forming apparatus is operating while the transferring unit and the photoconductive unit are not secured therein due to the inadvertency of the user. 
   SUMMARY OF THE INVENTION 
   An aspect of the present general inventive concept is to provide an image forming apparatus capable of notifying a user whether a transferring unit is properly mounted in a main body of the image forming apparatus. 
   Additional aspects and advantages 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. 
   The foregoing and/or other aspects of the present general inventive concept are achieved by providing an image forming apparatus that may include a main body, a photoconductive unit disposed in the main body to develop an image, a transferring unit removably disposed in the main body in contact with the photoconductive unit to transfer the image from the photoconductive unit onto a recording medium, a locking/releasing unit to lock and unlock a mounting position of the transferring unit with respect to the photoconductive unit, and a checking unit to check whether the transferring unit is mounted in the main body by the locking/releasing unit. 
   The checking unit may include a sensor to detect whether the transferring unit is positioned in close contact with the photoconductive unit by a locking operation of the locking/releasing unit, and a controller to receive a signal from the sensor and process the received signal. 
   The checking unit may be controlled by the controller and may further include a displayer to notify a user of the signal generated in the sensor. Alternatively, the checking unit can be controlled by the controller and may further include an alarming unit to notify a user of the signal generated in the sensor. 
   The image forming apparatus may further include a shock-absorbing unit disposed between the photoconductive unit and the transferring unit to prevent a shock occurring while the transferring unit is mounted in the main body. The checking unit may be disposed to check whether the transferring unit is in close contact with the photoconductive unit by overcoming an elastic force of the shock-absorbing unit due to the locking/releasing unit. The sensor may be an ON/OFF sensor. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and/or other aspects and advantages of the 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: 
       FIG. 1  is a cross-sectional view schematically showing an image forming apparatus according to an embodiment of the present general inventive concept; 
       FIG. 2  is a cross-sectional view showing a transferring unit in contact with a photoconductive unit in  FIG. 1 ; 
       FIG. 3  is a cross-sectional view showing the transferring unit in close contact with the photoconductive unit by a locking/releasing unit in  FIG. 1 ; and 
       FIG. 4  is a view showing the transferring unit being received in the image forming apparatus by the locking/releasing unit in  FIG. 1 ; 
       FIG. 5  is a view illustrating a cross-sectional view of an absorbing body disposed on a transferring unit and a pressing member being disposed on a photoconductive unit, according to an embodiment of the present general inventive concept. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the general inventive concept by referring to the figures.  FIG. 1  shows the image forming apparatus according to an embodiment of the general inventive concept. A reference P indicates a paper delivery path. 
   As shown in  FIG. 1 , the image forming apparatus  30  may include a photoconductive unit  10  having a photoconductive medium (OPC drum)  11 , a laser scanning unit  120 , a developing device  13 , a transferring unit  20  having a transfer belt  14 , plural rollers to rotate the transfer belt  14  on an endless track, and a fixing roller  21  to fix an image. The plural rollers may include a transfer roller  16  to transfer the image onto the transfer belt  14 , a drive roller  19  to supply a driving force to the transfer belt  14 , a tension roller  18  and a nip roller  17  to adjust a tension of the transfer belt  14 , and a backup roller  15  to idle according to the rotation of the drive roller  19 . 
   The image forming apparatus  30  sequentially performs procedures such as charging, laser scanning, developing, transferring, and fixing to print a desired image on a paper. 
   Referring to  FIGS. 2 and 3 , the image forming apparatus  30  can check whether the transferring unit  20  is secured by the locking/releasing unit  40 .  FIG. 2  shows the transferring unit  20  in contact with the photoconductive unit  10  of  FIG. 1 .  FIG. 3  shows the transferring unit  20  in close contact with the photoconductive unit  10  with the aid of the locking/releasing unit  40  in  FIG. 1 . 
   As shown in  FIGS. 2 and 3 , the image forming apparatus  30  may include the photoconductive unit  10 , the transferring unit  20 , the locking/releasing unit  40 , and a checking unit  100 . 
   The photoconductive unit  10  on which the image is formed may include a photoconductive unit body  12  forming an external appearance of the photoconductive unit  10 , and a shock-absorbing unit  50  disposed at a side of the photoconductive unit body  12 . The shock-absorbing unit  50  may be disposed between the photoconductive unit  10  and the transferring unit  20  to prevent a shock from occurring when the transferring unit  20  is mounted on the photoconductive unit  10 . 
   The shock-absorbing unit  50  has an absorbing body  51  movably disposed at the photoconductive unit body  12  and an elastic member  53  to provide an elastic force to the absorbing body  51 . 
   The transferring unit  20  is removably disposed in a main body  31  of the image forming apparatus  30  to make contact with the photoconductive unit  10 , and transfers the image developed in the photoconductive unit  10  onto a recording medium, such as a paper. 
   The transferring unit  20  may have a transferring unit body  22  forming an external appearance of the transferring unit  20  and a first and second guide members  21  and  24 , respectively, disposed at two sides of the transferring unit body  22  to guide the transferring unit  20  into the image forming apparatus  30 . At both sides of the transferring unit body  22  at which the first and second guide members  21  and  24  are disposed, a pressing member  26  is also disposed to press the shock-absorbing unit  50  of the photoconductive unit  10 . 
   In  FIG. 2 , the shock-absorbing unit  50  is illustrated as being disposed at the photoconductive unit  10  and the pressing member  26  is illustrated as being disposed at the transferring unit  20 . However, the shock-absorbing unit  50  may be disposed at the transferring unit  20  while the pressing member  26  is disposed at the photoconductive unit  10 , alternatively. 
   The locking/releasing unit  40  can be disposed at the main body  31  to lock and release the transferring unit  20  to and from the photoconductive unit  10 . 
   The locking/releasing unit  40  can be disposed at both sides of the main body  31  so that two locking releasing units  40  can correspond to each other, and has a rotary lever  41 , a rotary cam  42 , and a connection bar  43  to interconnect the rotary cam  42  and the rotary lever  41  for an association therebetween. 
   Referring to  FIG. 4 , a user can manually rotate the rotary lever  41 . At a side of the rotary lever  41  a covering unit  44  may be formed to securely lock the second guide member  24  of the transferring unit  20  received in an upper receiving unit  31   b  of the main body  31 . 
   The rotary cam  42  may have a rail unit  42   a  to be connected to a second guide rail  34  formed at the main body  31 , and a pressing unit  42   b  rotatably disposed at the main body  31  to press and lock a guide member  89  of the photoconductive unit  10  received in a lower receiving unit  31   a  during the rotation. 
   The checking unit  100  checks whether the transferring unit  20  is mounted on the photoconductive unit  10  by the locking/releasing unit  40  and can include a sensor  80 , a controller (C)  70 , and a displayer  60  that may be disposed in the image forming apparatus  30 . 
   The sensor  80  can detect whether the transferring unit  20  is in tight contact with the photoconductive unit  10  by the locking operation of the locking/releasing unit  40 . Specifically, when received in the main body  31  and in contact with the photoconductive unit  10 , the transferring unit  20  is separated from the sensor  80  by a distance H (see  FIG. 2 ). 
   At this time, by rotating the locking/releasing unit  40  in a direction A, the transferring unit  20  is securely fixed within the main body  31  and to the photoconductive unit  10 , and can contact the sensor  80 , as shown in  FIG. 3 . 
   The sensor  80  may be an ON/OFF sensor. For example, while not contacting the transferring unit  20 , the sensor  80  may be turned on, and while contacting the transferring unit  20 , the sensor  80  can send an off signal to the controller  70 . Also, the sensor  80  may be a photo sensor having an emitting unit and a receiving unit. The sensor  80  checks whether the transferring unit  20  overcomes the elastic force of the shock-absorbing unit  50  by the locking/releasing unit  40  and makes contact with the photoconductive unit  10 . 
   The controller  70  can receive and process a signal from the sensor  80  and can send the processed signal to the displayer  60  and/or an alarming unit  65 . 
   The displayer  60  displays the received signal on a screen, such as, for example, a liquid crystal screen, and the alarming unit  65  can notify the user of the received signal as an audio signal. The controller  70  determines the signal from the sensor  80 . If the image forming apparatus  30  is operated while the locking/releasing unit  40  is not operated to secure the transferring unit  20  to the photoconductive unit  10  and the image forming apparatus  30 , the controller  70  can send an error or warning message to the displayer  60  and/or the alarming unit  65 . 
   Then, the user can be notified that the transferring unit  20  is not completely mounted in the image forming apparatus  30 . To secure the transferring unit  20  to the image forming apparatus  30 , the user operates the locking/releasing unit  40  of the image forming apparatus  30 . 
   Referring to  FIG. 4 , a procedure to mount the transferring unit  20  in the image forming apparatus  30  by the locking/releasing unit  40  is described. 
   At an upper part of a mounting portion of the main body  31 , an entrance is formed to be opened and closed by a door  32 . The transferring unit  20  can be exchanged through the entrance opened by the door  32 . A frame  39  can be disposed at the mounting portion in the main body  31  and has a first and the second guide rails  35  and  34 , respectively. The first guide rail  35  guides the first guide member  21  and the second guide rail  34  guides the second guide member  24  of the transferring unit  20 . 
   The photoconductive unit  10  is described below as already being mounted in the main body  31  of the image forming apparatus  30 , and therefore a detailed description thereof is omitted. 
   With the photoconductive unit  10  being mounted in the main body  31 , the transferring unit  20  can be mounted along the first and second guide rails  35  and  34 . Then, by rotating the rotary lever  41  of the locking/releasing unit  40 , the pressing unit  42   b  of the rotary cam  42  presses down the guide member  89  of the photoconductive unit  10  to lock the photoconductive unit  10 . Simultaneously, the covering unit  44  of the rotary lever  41  can cover and lock the second guide member  24  of the transferring unit  20 . 
   The first guide rail  35  can have an auxiliary locking unit to lock the first guide member  21  of the transferring unit  20 . The auxiliary locking unit can include an interference lever  45  rotatably disposed at the frame  39  and a spring  46  to elastically bias a free end  48  of the interference lever  45  to protrude toward the first guide rail  35 . 
   The free end  48  of the interference lever  45  can have a sloped surface and a stepped surface. Due to the sloped surface, the first guide member  21  can smoothly slide downward along the first guide rail  35 . Also, the first guide rail  35  is obstructed by the stepped surface while sliding upward along the first guide rail  35 . 
   In the above construction, to mount the transferring unit  20  into the main body  31  in which the photoconductive unit  10  is being mounted, the first guide member  21  of the transferring unit  20  can slide along the first guide rail  35  and can enter into a mounting position. The first guide member  21  can climb down the free end  48  of the interference lever  45  and be received therein. 
   After the entrance of the first guide member  21  along the first guide rail  35 , the second guide member  24  can enter into the second guide rail  34  and can be received at the upper receiving unit  31   b . As a result, the transferring unit  20  is completely mounted in the main body  31 . Next, the transferring unit  20  can be securely fixed at the main body  31  by the locking operation described above with respect to the locking/releasing unit  40 . 
   As described above, the locking operation can be carried out by rotating the rotary lever  41  of the locking/releasing unit  40 . If a user rotates the rotary lever  41  in the direction A (see  FIGS. 2 and 4 ) for the locking operation, the covering unit  44  of the rotary lever  41  can cover and prevent the second guide member  24  of the transferring unit  20  from escaping upward. The pressing unit  42   b  of the rotary cam  42  can lock the guide member  89  to prevent it from moving by pressing the guide member  89  of the photoconductive unit  10  toward the lower receiving unit  31   a . Accordingly, unless the rotary lever  41  is rotated back to an original position, the transferring unit  20  is securely locked by the locking/releasing unit  40 . 
   While locked in the main body  31  as shown in  FIGS. 2 and 3 , the transferring unit  20  is in close contact with the sensor  80 , and the sensor  80  sends the signal to the controller  70  notifying the controller  70  of this state. Receiving the signal from the sensor  80 , the controller  70  can send a checking signal to the displayer  60  and/or the alarming unit  65  to check whether the transferring unit  20  is fixed within the main body  30  so that the user can determine whether the image forming apparatus  30  is operating while the transferring unit  20  is completely mounted therein. 
   If the image forming apparatus  30  operates while the transferring unit  20  is not completely mounted therein, the displayer  60  can display a warning message or a flickering message and/or the alarming unit  65  can output an audio message to the outside. 
   According to the present general inventive concept, the image forming apparatus  30  can prevent the image formed on the photoconductive unit  10  from being incompletely transferred to the transferring unit  10  due to the transferring unit  20  not accurately being in contact with the photoconductive unit  10 . 
   Further, malfunctioning of the image forming apparatus  30  and troubles with the transferring unit  10  can be reduced, which may occur when the transferring unit  10  is not completely fixed in the image forming apparatus  30  during operation thereof. 
   In addition, the image forming apparatus  30  provides convenience to the user by notifying the user that the image forming apparatus  30  is operating while the transferring unit  20  and the photoconductive unit  10  are not properly fixed therein by the locking/releasing unit  40  due to inadvertent installation thereof by the user. 
   Although a few embodiments of the present general inventive concept have been shown and described, the present general inventive concept is not limited to the disclosed embodiments. Rather, it would be appreciated by those skilled in the art that changes and modifications may be made to the embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined by the claims and their equivalents.