BACKGROUND 
     1. Field of the Invention 
     The present invention relates generally to an electronic locking system to secure consumable items in an image forming device, and particularly to an electronic locking system for a media tray to secure media sheets in an image forming device. 
     2. Description of the Related Art 
     Image forming devices generally use consumable items like toner, media sheets, etc., to execute printing. The image forming device generally includes containers to hold the consumable items, e.g., the image forming device includes a media tray to hold media sheets. The consumable item may include valuable media sheets like doctors&#39; prescriptions, bankers&#39; bearer bonds, etc. As can be seen, it is necessary to securely maintain such valuable media sheets inside the image forming device, so as to prevent the media sheets from being improperly used. Even rather modestly valuable consumable material such as toner or ink, when used in an environment in which a relatively large number of people have access to the consumable material, may need to be secured so as to prevent their theft. 
     A mechanical locking system is well known in the art for locking the media trays. In prior mechanical locking systems, a mechanical key is used to lock the media tray within the image forming device. However, it may be impractical for one user to carry the mechanical key for each and every media tray. Further, if any of the mechanical keys are lost, the manufacturer has to make a new serialized key. The time consumed in making the new serialized key may cause an unnecessary interruption in printing. Moreover, an unlocked media tray may be easily opened at an inopportune time, e.g., while the image forming device is printing, which generally causes paper jams. 
     It would therefore be desirable to provide an effective locking system that obviates the above-mentioned problems. 
     SUMMARY OF THE INVENTION 
     Disclosed herein is an electronic locking system to secure consumable items in an image forming device. The system includes a first member to hold the consumable item and which is movable between an open position and a closed position; a receiving member configured to receive the first member, the receiving member including a locking member; and a controller for controlling the locking member to lock the first member to the receiving member when the first member is in the closed position and to unlock the first member from the receiving member so that the first member is movable to the open position. 
     In some embodiments, the locking member includes a drive device and a plunger such that the drive device moves the plunger between a lock and an unlock position. The controller is configured to control the drive device to move the plunger to engage a portion of the first member in the lock position, and to move the plunger to disengage from the portion of the first member in the unlock position. 
     In some embodiments, the image forming device includes an I/O interface for receiving codes such that when a correct code is received the controller controls the drive device to move the plunger to the unlock position. 
     In other embodiments, the controller controls the drive device to move the plunger to the unlock position only when the image forming device is not printing. 
     In some embodiments, the controller records the time the correct code is entered into the image forming device and stores the recorded time along with the corresponding correct code in a memory. 
     In another embodiment, the first member comprises a media tray, the consumable item comprises one or more sheets of media, and the receiving member comprises a tray receiving member. 
     In other embodiments, the tray receiving member includes a sensing member that detects the media tray disposed within the tray receiving member and, in response to detection by the sensing member, the controller controls the drive device to move the plunger to the lock position. 
     In other embodiments, following the controller controlling the drive device to move the plunger to the unlock position, the controller controls the drive device to move the plunger to the lock position upon completion of a predetermined time period during which the media tray remains positioned inside the tray receiving member as sensed by the sensing member. 
     Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings. 
     It is to be understood that both the foregoing general description and the following detailed description of the present embodiments of the invention and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the invention and together with the description serve to explain the principles and operation of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of the various embodiments of the invention, and the manner of attaining them, will become more apparent and will be better understood by reference to the accompanying drawings, wherein: 
         FIG. 1  is a block diagram of one embodiment of an electronic locking system to secure consumable items in an image forming device according to the present invention; 
         FIG. 2  is an isometric view of an image forming device that may be used in the system of  FIG. 1 , including a media tray electronically lockable inside a tray receiving member; 
         FIG. 3  is a partial cross section view of a bidirectional solenoid including a plunger attachable to the tray receiving member of  FIG. 2 ; 
         FIG. 4  is a front elevational view of the tray receiving member of  FIG. 2 , illustrating a sensing member to be used with the media tray; 
         FIG. 5  is a perspective view of the media tray of  FIG. 2 , including a depression; 
         FIG. 6A  is a partial perspective view of the plunger of  FIG. 3  partially moved downward to engage the depression provided on the media tray of  FIG. 5 ; 
         FIG. 6B  is a partial perspective view of the plunger of  FIG. 3  moved upward to disengage from the depression provided on the media tray of  FIG. 5 ; 
         FIG. 7  is a flow chart illustrating the use of the system of  FIG. 1 ; 
         FIG. 8  is a perspective view of the image forming device of  FIG. 2  including a front cover having a door electronically lockable according to the present invention; 
         FIG. 9  is a perspective view of a latching assembly affixed to a housing of the image forming device and engaged with a locking member included inside the image forming device of  FIG. 8 ; and 
         FIG. 10  is a schematic diagram of a latching member disposed on the door of  FIG. 8  that moves downward to engage a pin member disposed on the latching assembly of  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the exemplary embodiment(s) of the invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. 
       FIG. 1  illustrates one embodiment of an electronic locking system  100  to secure consumable items in an image forming device  110  according to the present invention. The electronic locking system  100  includes a first member  120  to hold consumable items, a receiving member  130  to receive the first member  120 , and a controller  140 . The first member  120  is movable between an open and a closed position relative to the receiving member  130 . In the closed position, the first member  120  is positioned inside the receiving member  130 . The receiving member  130  includes a locking member  150 . The controller  140  controls the locking member  150  to lock the first member  120  to the receiving member  130  in the closed position. The controller  140  also controls the locking member  150  to unlock the first member  120  from the receiving member  130  so that the first member  120  is movable to the open position. In the open position, the first member  120  provides access to the consumable item. Generally, the receiving member  130  is an opening formed inside a housing  200  (shown in  FIG. 2 ) of the image forming device  110  and the first member  120  is movably positioned within the receiving member  130 . 
     The locking member  150  comprises a drive device  150   a  and a plunger  150   b . Essentially, the drive device  150   a  moves/drives the plunger  150   b  between a locked and an unlocked position. The drive device  150   a  may be a motor, a bidirectional solenoid, a servo, etc. When the first member  120  is positioned inside the receiving member  130 , the controller  140  controls the drive device  150   a  to move the plunger  150   b  to the locked position. In the locked position, the plunger  150   b  engages a portion of the first member  120  preventing the first member from moving relative to the receiving member  130 . Thus, when the first member  120  is locked to the receiving member  130 , the consumable items in the first member  120  are inaccessible to a user or anyone who may try to remove them. 
     In accordance with an exemplary embodiment of the present invention, in order to unlock the first member  120  a correct code is required to be entered into the image forming device  110 . The correct code is a predetermined code stored in memory  170  in the image forming device  110 . The image forming device  110  includes an interface  160  to receive the code from the user. The code is either directly entered by a user or is entered through a device on which the code is stored. The device may be one of an ID card, a credit card, a thumbnail or a flash drive, and a biometric scanner (not shown). The biometric scanner may include at least one of a fingerprint scanner, a palm scanner, and an eye scanner. Once a code is received, controller  140  compares the received code with the code stored in memory  170  to determine whether the received code is a correct code. 
     When the correct code is entered into the image forming device  110 , the controller  140  controls the drive device  150   a  to move the plunger  150   b  to the unlocked position. In the unlocked position, the plunger  150   b  is retracted and disengages from the portion of the first member  120  allowing the first member  120  to move to the open position. In the open position the consumable item is accessible to the user. 
     The controller  140  may record the time the correct code (or even an incorrect code in order to monitor unsuccessful attempts) is entered into the image forming device  110 , i.e., when the first member  120  is unlocked. The recorded time, along with the corresponding correct code, is stored in a memory  170  associated with the image forming device  110 . The recorded code and time helps in tracing the person who unlocked the first member  120  and when it was unlocked. 
     In one embodiment, as illustrated in  FIG. 2 , the first member  120  is illustrated as a media tray  120  and the receiving member  130  is a tray receiving member. The media tray  120  is configured to hold one or more media sheets and the tray receiving member  130  is an opening in the image forming device  110 . The tray receiving member  130  includes the locking member  150 . The locking member  150  includes a bidirectional solenoid  300  and the plunger  150   b  coupled thereto (see  FIG. 3 ). The bidirectional solenoid  300  moves the plunger  150   b  between the locked and the unlocked position. The controller  140  energizes the bidirectional solenoid  300  in a first direction to move the plunger  150   b  to the locked position. In the locked position, the plunger  150   b  engages a portion of the media tray  120 . The controller  140  energizes the bidirectional solenoid  300  in a second direction opposite the first direction to move the plunger  150   b  to the unlocked position. In the unlocked position, the plunger  150   b  disengages from the portion of the media tray  120 . 
     The media tray  120  is also movable between the open and the closed position. In the closed position, the media tray  120  is positioned inside the tray receiving member  130  in the image forming device  110 . The tray receiving member  130  includes a sensing member  400  (see  FIG. 4 ), which detects if the media tray  120  is positioned inside the tray receiving member  130 . The media tray  120  includes tray size sensing fingers  510  (see  FIG. 5 ) that compresses the sensing member  400  when the media tray  120  is positioned inside the tray receiving member  130 . When the sensing member  400  is compressed, the controller  140  detects that the media tray  120  is positioned inside the tray receiving member  130  and the controller  140  then energizes the bidirectional solenoid  300  to move the plunger  150   b  to the locked position. 
     In the locked position, the plunger  150   b  engages a portion of the media tray  120 . For example, the plunger  150   b  engages a depression  500  provided on the media tray  120 . As shown in  FIG. 5 , depression  500  may be formed along an upper surface of a side member of media tray  120 . The depression  500  may be an opening, a hole, a cut-out or any other concave surface to engage and/or receive the plunger  150   b  when plunger  150   b  is in the locked position and prevent the media tray  120  from being removed from the image forming device  110 . The plunger  150   b  may be movable vertically in upward and downward directions but other directions are also possible and come within the scope of the present invention. When the bidirectional solenoid  300  is energized in the first direction the plunger  150   b  moves downwardly to engage (mate with) the depression  500  provided on the media tray  120 . When the plunger  150   b  engages the depression  500  the media tray  120  is locked within image forming device  110  and cannot be removed.  FIG. 6A  illustrates the plunger  150   b  partially moved downward to lock the media tray  120 . Essentially, when the media tray  120  is positioned inside the tray receiving member  130  the controller  140  energizes the bidirectional solenoid  300  in the first direction to move the plunger  150   b  downward to lock the media tray  120 . 
     Alternatively, solenoid  300  and plunger  150   b  may be mounted on the bottom of the tray receiving member  130  such that plunger  150   b  moves upwardly to lock the media tray  120  by engaging with depression  500  formed along a bottom surface along a side of media tray  120  (not shown). Similarly, the solenoid  300  may be horizontally mounted on one side of receiving member  130  so that plunger  150   b  moves in a horizontal direction to engage with depression  500  defined along a side surface of the media tray  120 . 
     As explained above, in order to unlock the media tray  120 , a code is required to be entered into the image forming device  110 . When the code is entered into the image forming device  110 , the controller  140  determines if the code is the correct code. It is possible that there may be more than one correct code to assist in identifying the user or for other reasons. If the code is a correct code, the controller  140  energizes the bidirectional solenoid  300  in the second direction to move the plunger  150   b  to disengage from the depression  500  (as shown in  FIG. 6B ) to unlock the media tray  120 . In one embodiment, the controller  140  controls the bidirectional solenoid  300  to unlock the media tray  120  only when the image forming device  110  is not printing. In another embodiment, the controller  140  controls the bidirectional solenoid  300  to automatically unlock the media tray  120  when the media tray  120  is empty. The date and the time when the media tray  120  is unlocked and the corresponding correct code are stored in the memory  170  of the image forming device  110 , as mentioned above. 
     In one embodiment, after the controller  140  controls the bidirectional solenoid  300  to move the plunger  150   b  to the unlocked position, the controller  140  controls the bidirectional solenoid  300  to return the plunger  150   b  to the locked position after a predetermined time period (a timeout period) if the media tray  120  remains positioned inside the tray receiving member  130  as sensed by the sensing member  400 . This prevents the media tray  120  from being accidentally left unlocked for a prolonged period of time while remaining within tray receiving member  130 . Controller  140  may include a timer or the like for monitoring the timeout period. In this regard, the timer may be activated following controller  140  causing plunger  150   b  to be moved to the unlock position and remain activated until media tray  120  is removed from tray receiving member  130 . The timer may also be activated when media tray  120  is returned to the closed position within tray receiving member  130 . 
       FIG. 7  is a flowchart illustrating a method for electronically locking and unlocking the media tray  120 . The controller  140  determines if the media tray  120  is locked and secured at S 101 . If the media tray  120  is secured, the controller  140  determines if a code is entered into the image forming device  110  at S 102 . At S 103 , the controller  140  determines if the code is a correct, predetermined code. If the code is the correct, predetermined code, the controller  140  determines whether the image forming device  110  is performing a printing operation at S 104 . If the image forming device  110  is performing the printing operation, the controller  140  delays the unlocking of the media tray  120 , i.e., keeps the media tray  120  locked until the printing operation is complete. If the image forming device  110  is not printing, the controller  140  energizes the bidirectional solenoid  300  in the second direction to unlock the media tray  120  at S 105 . 
     In one embodiment, if the media tray  120  is secured at S 101 , the controller  140  determines if the media tray  120  is empty at S 106 . If the media tray  120  is empty, the controller  140  determines if the image forming device  110  is configured to automatically open at S 107 . If the image forming device  110  is configured to auto open, the controller  140  confirms if the print job in process at S 104 . In case the print job is not in process, the controller  140  energizes the bidirectional solenoid  300  to unlock the media tray  120  at S 105 . However, if the media tray  120  is not empty, the controller  140  keeps the media tray  120  locked. 
     Once the media tray  120  is unlocked and becomes unsecured at S 108 , the controller  140  detects if the predetermined time period occurred without media tray  120  being opened. This can be seen in blocks S 110  and S 111 . If the timeout period occurred without media tray  120  being opened, the controller  140  energizes the bidirectional solenoid  300  to lock the media tray  120  at S 109 . In case the media tray  120  is removed before the timeout period has elapsed, the controller  140  determines if the media tray  120  is reinstalled at S 112 . If the media tray  120  is reinstalled, the controller  140  energizes the bidirectional solenoid  300  to lock the media tray  120  at S 109 . In one embodiment, when the image forming device  110  is powered on at S 113 , the controller  140  energizes the bidirectional solenoid  300  to lock the media tray  120 . 
     In another embodiment according to the present invention, as illustrated in  FIGS. 8-10 , the first member includes a cover  120 ′ for accessing at least one cartridge containing toner or ink, and the receiving member includes a cover receiving member  130 ′ disposed within the housing  200  of image forming device  110 . The cover  120 ′ may be pivotally attached to the housing  200  via hinges  830 . A portion of cover  120 ′ forms a door  800  movable between an open and a closed position. When the door  800  is in the open position, the toner cartridge(s) is/are accessible. The door  800  is coupled to a latching assembly  810 . The latching assembly  810  is affixed to the housing  200 . The latching assembly  810  includes a button member  820  and a spring  840  coupled thereto. The button member  820  is horizontally movable along a frame portion of latching assembly  810  between a latched and an unlatched position. An external force, such as a user applied force, may be applied on the button member  820  to move the button member  820  towards the left in  FIG. 9  (shown by arrow A) to the unlatched position. When the external force is released, the spring  840  urges the button member  820  towards the right in  FIG. 9  (shown by arrow B) to the latched position. 
     The button member  820  is coupled to a latch member  850  movable therewith. The latch member  850  may include a pin member  860 . The latch member  850  is engageble with a latching member provided on the door  800 . For example, the door  800  may include a latching member  870  resembling an inverted “4” shape (shown in  FIG. 10 ) that is engageble with the pin member  860  of the latch member  850 .  FIGS. 10  (A, B, and C) illustrates a downward movement of the latching member  870  (shown by arrow Y) to engage the pin member  860  when door  800  is moved to the closed position and latched to housing  200 . 
     Usually, when the door  800  is not latched with the latching assembly  810 , a spring (not shown) coupled to the door  800  urges it to the open position. In the open position, the toner cartridge is accessible. In order to latch the door  800  to the latching assembly  810 , the door  800  is closed and the door  800  is moved downward by applying an external, user applied force thereto. When the door  800  is moved downward, the door&#39;s latching member  870  (the inverted 4 shape) moves into engagement with the pin member  860  (as shown in  FIG. 10 , A-C). Specifically, as the door  800  is moved further downward, the door&#39;s latching member  870  temporarily moves the pin member  860  along with the button member  820  towards the left (indicated by arrow A in  FIG. 9 ) to the unlatched position, overcoming the spring force applied by the spring  840 . This temporary displacement of pin member  860  can be seen as latching member  870  moves from position A to position B in  FIG. 10 . However, once the door&#39;s latching member  870  engages with the pin member  860  (position C of  FIG. 10 ), the spring  840  applies a force to move the button member  820  along with the pin member  860  towards the right (indicated by arrow B in  FIG. 9 ) to the latched position. In the latched position, the door  800  is latched with the latching assembly  810 . 
     In the latched position, the controller  140  energizes the bidirectional solenoid  300  in the first direction to move the plunger  150   b  in a direction indicated by arrow R (see  FIG. 9 ) to the locked position. In the locked position, the plunger  150   b  engages a portion of the latching member  810 . For example, the plunger  150   b  may engage the button member  820 . Once the plunger  150   b  is so engaged, the button member  820  may not be moved from the latched position, thereby locking the door  800  in the closed position. In the closed position, the door  800  cannot be opened. 
     In general terms, the operation of the locking mechanism of embodiment of  FIGS. 8-10  follows the flow chart of  FIG. 7 . In order to move the plunger  150   b  to the unlocked position, a code is entered into the image forming device  110 . The I/O interface  160  provides an option for entering the code for unlocking the door  800  of the cover  120 ′. When the code is entered into the image forming device  110 , the controller  140  determines if the code is the correct code for unlocking the door  800 . If the code is the correct code the controller  140  controls the bidirectional solenoid  300  to move the plunger  150   b  in a direction indicated by arrow L to the unlocked position. The controller  140  energizes the bidirectional solenoid  300  in the second direction to move the plunger  150   b  to the unlocked position. In the unlocked position, the plunger  150   b  is disengaged from the button member  820 . 
     When the plunger  150   b  is disengaged from the button member  820 , the button member  820  may be moved to the unlatched position by applying an external force. In the unlatched position, the pin member  860  disengages from the door&#39;s latching member  870  and the spring coupled to the door  800  urges the door  800  to the open position. In the open position, the toner cartridge(s) is/are accessible. 
     In one embodiment, the controller  140  energizes the bidirectional solenoid  300  to unlock the door  800  only when the image forming device  110  is not printing. In another embodiment, the controller  140  automatically energizes the bidirectional solenoid  300  in the second direction to unlock the door  800  when the toner cartridge is consumed. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. Thus it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
An electronic locking system to secure consumable items in an image forming device and a method therefore. In one embodiment of the invention, an electronic locking system to secure media sheets includes a media tray to hold media sheets, a tray receiving member for receiving the media tray, and a controller. The tray receiving member includes a drive device and a plunger. The plunger is moved by the drive device between a locked and an unlocked position. The controller is configured to control the drive device to move the plunger to engage a portion of the media tray in the locked position and to move the plunger to disengage from the portion of the media tray in the unlocked position. The electronic locking system, incorporating the controller, provides an effective and efficient way to lock/unlock the media tray and eliminates the use of mechanical keys.