Patent Publication Number: US-10775734-B2

Title: Image forming apparatus with plural covers and a lock control unit

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application relates to and claims priority rights from Japanese Patent Application No. 2018-149850, filed on Aug. 9, 2018, the entire disclosures of which are hereby incorporated by reference herein. 
     BACKGROUND 
     1. Field of the Present Disclosure 
     The present disclosure relates to an image forming apparatus. 
     2. Description of the Related Art 
     An image forming apparatus includes a cover for a user to remove a jammed printing sheet when a printing sheet jam occurs, and locks the cover using a lock mechanism so as to prevent the cover from being opened when a printing sheet jam occurs, and unlocks the cover if a predetermined-year-old user or older inputs login information. 
     However, in the aforementioned image forming apparatus, every user who is the predetermined years old or older can unlock the cover, and therefore a manual operation for resolving the trouble may not be performed properly by a user who is not familiar to a structure of the apparatus. 
     SUMMARY 
     An image forming apparatus according to an aspect of the present disclosure includes plural covers installed on a housing, plural cover lock units, and a lock control unit. The plural covers are capable of being opened and closed. The plural cover lock units are configured to lock a predetermined cover among the plural covers and unlock the predetermined cover in accordance with a control signal. The lock control unit is configured to control the cover lock units and thereby change a status of the cover from one to the other among lock status and unlock status. The plural covers include a first cover, a second cover, and a third cover, the first cover on which the cover lock unit is not installed, the second cover on which the cover lock unit is installed and that a predetermined user and a service person are allowed to unlock, the third cover on which the cover lock unit is installed and that the service person is allowed to unlock. The lock control unit determines whether the lock control unit unlocks the second cover or not on the basis of a user level of either a user who is in login status or an authenticated user. 
     These and other objects, features and advantages of the present disclosure will become more apparent upon reading of the following detailed description along with the accompanied drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a side view that indicates a partial internal mechanical configuration of an image forming apparatus in an embodiment according to the present disclosure; 
         FIG. 2  shows a block diagram that indicates an electronic configuration of the image forming apparatus in the embodiment according to the present disclosure; 
         FIG. 3  shows a diagram that indicates an example of positions of covers and sensors installed on a housing of the image forming apparatus in the embodiment according to the present disclosure; and 
         FIG. 4  shows a flowchart that explains a behavior of the image forming apparatus shown in  FIGS. 1 to 3 . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, an embodiment according to an aspect of the present disclosure will be explained with reference to drawings. 
       FIG. 1  shows a side view that indicates a partial internal mechanical configuration of an image forming apparatus in an embodiment according to the present disclosure. The image forming apparatus shown in  FIG. 1  is an apparatus having an electrophotographic printing function, such as a printer, a facsimile machine, a copier or a multi function peripheral. 
     The image forming apparatus in this embodiment includes a tandem-type color development device. This color development device includes photoconductor drums  1   a  to  1   d , exposure devices  2   a  to  2   d , and development devices  3   a  to  3   d . The photoconductor drums  1   a  to  1   d  are photoconductors of four colors: Cyan, Magenta, Yellow and Black. 
     The exposure devices  2   a  to  2   d  are devices that form electrostatic latent images by scanning and irradiating the photo conductor drums  1   a  to  1   d  with laser light, respectively. The photo conductor drum  1   a ,  1   b ,  1   c  or  1   d  is scanned with the laser light in a direction (a primary scanning direction) perpendicular to a rotation direction (a secondary scanning direction) of the photoconductor drum. The exposure devices  2   a  to  2   d  include laser scanning units that include laser diodes as light sources of the laser light, optical elements (such as lens, mirror and polygon mirror) that guide the laser light to the photoconductor drums  1   a  to  1   d , respectively. 
     Further, the periphery of each one of the photo conductor drums  1   a  to  1   d  includes a charging unit such as scorotron, a cleaning device, a static electricity eliminator and the like. The cleaning device removes residual toner on each one of the photo conductor drums  1   a  to  1   d  after primary transfer. The static electricity eliminator eliminates static electricity of each one of the photoconductor drums  1   a  to  1   d  after primary transfer. 
     The development unit  3   a ,  3   b ,  3   c  or  3   d  includes a toner cartridge and a development device. The toner cartridge contains toner of one of four colors: Cyan, Magenta, Yellow, and Black. The toner is supplied from a toner hopper in the toner cartridge to the development device. The development device adheres the toner on the photoconductor drum  1   a ,  1   b ,  1   c , or  1   d . The development unit  3   a ,  3   b ,  3   c , or  3   d  forms a toner image by adhering the toner to an electrostatic latent image on the photoconductor drum  1   a ,  1   b ,  1   c , or  1   d.    
     The photoconductor drum  1   a , the exposure device  2   a  and the development device  3   a  perform development of a Magenta component of an image to be printed. The photoconductor drum  1   b , the exposure device  2   b  and the development device  3   b  perform development of a Cyan component of an image to be printed. The photoconductor drum  1   c , the exposure device  2   c  and the development device  3   c  perform development of a Yellow component of an image to be printed. The photoconductor drum  1   d , the exposure device  2   d  and the development device  3   d  perform development of a Black component of an image to be printed. 
     An intermediate transfer belt  4  is a loop-shaped image carrier (here an intermediate transfer member), and contacts the photoconductor drums  1   a  to  1   d . Toner images on the photoconductor drums  1   a  to  1   d  are primarily transferred onto the intermediate transfer belt  4 . The intermediate transfer belt  4  is hitched around driving rollers  5 , and rotates by driving force of the driving rollers  5  towards the direction from the contact position with the photoconductor drum  1   d  to the contact position with the photoconductor drum  1   a.    
     A transfer roller  6  makes an incoming printing sheet contact the transfer belt  4 , and secondarily transfers the toner image on the transfer belt  4  to the printing sheet. The printing sheet on which the toner image has been transferred is transported to a fuser  9 , and consequently, the toner image is fixed on the printing sheet. 
     A roller  7  includes a cleaning brush, and removes residual toner on the intermediate transfer belt  4  by the cleaning brush contacting to the intermediate transfer belt  4  after transferring the toner image to the printing sheet and/or after toner density calibration or toner gradation calibration. 
     A sensor  8  irradiates the intermediate transfer belt  4  with a light beam, and detects its reflection light from a surface of the intermediate transfer belt  4  or a toner pattern on the intermediate transfer belt  4 . For example, in toner gradation calibration, the sensor  8  irradiates a predetermined area (an area onto which a toner patch for calibration is transferred) on the intermediate transfer belt  4  with a light beam, detects its reflection light, and outputs an electronic signal corresponding to the received light amount. 
     Further, the image forming apparatus of this embodiment includes plural printing sheet cassettes  11  to  14 . The printing sheet cassettes  11  and  12  are installed in a main body of the image forming apparatus, and the printing sheet cassettes  13  and  14  are installed in an option sheet feeding device that is mountable to and demountable from the main body of the image forming apparatus. 
     The printing sheet cassettes  11  to  14  are capable of storing printing sheets  101  to  104 , and push up the printing sheets  101  to  104  using lift plates  21 ,  24 ,  31  and  34  so as to cause the printing sheets  101  to  104  to contact with pickup rollers  22 ,  25 ,  32  and  35 , respectively. The printing sheets  101  to  104  on the sheet cassettes  11  to  14  are fed to sheet feeding rollers  23 ,  26 ,  33  and  36  by the pickup rollers  22 ,  25 ,  32  and  35  one by one from the tops of bunches of the printing sheets  101  to  104 , respectively. The sheet feeding rollers  23 ,  26 ,  33  and  36  are rollers that transport to a sheet transportation path the printing sheets  101  to  104  one by one fed by the pickup rollers  22 ,  25 ,  32  and  35  from the sheet cassettes  11  to  14 , respectively. 
     A transportation roller  27  is a transportation roller on a transportation path common to the printing sheets  101  to  104  transported from the printing sheet cassettes  11  to  14 . 
     A registration roller  41  temporarily stops the printing sheet in transportation, and at a second feeding timing, transports the printing sheet to a transfer position between the intermediate transfer belt  4  and the transfer roller  6 . The second feeding timing is specified by a controller  61  mentioned below so as to cause a toner image on the intermediate transfer belt  4  to be transferred to a specified position on the printing sheet. 
     A registration sensor  42  is installed near the registration roller  41 , and is an optical sensor that detects that the printing sheet  101 ,  102 ,  103  or  104  on the transportation path reaches the registration roller  41 . 
     A transportation sensor  43  is an optical sensor that the detects that the printing sheet  101 ,  102 ,  103  or  104  on the transportation path reaches a predetermined position (i.e. installation position of the transportation sensor  43 ). The transportation sensor  43  is installed on an upstream side of the registration sensor  42  in the main body of the image forming apparatus. 
     A transportation sensor  44  is an optical sensor that the detects that the printing sheet  103  or  104  on the transportation path reaches a predetermined position (i.e. installation position of the transportation sensor  44 ). The transportation sensor  44  is installed in the aforementioned option sheet feeding device. 
     A transportation sensor  45  is an optical sensor that the detects that the printing sheet  101 ,  102 ,  103  or  104  on the transportation path reaches a predetermined position (i.e. installation position of the transportation sensor  45 ). The transportation sensor  45  is installed on a downstream side of the fuser  9  in the main body of the image forming apparatus. 
     A bridge transportation sensor  46  is an optical sensor that the detects that the printing sheet  101 ,  102 ,  103  or  104  on the transportation path reaches a predetermined position (i.e. installation position of the bridge transportation sensor  46 ). The bridge transportation sensor  46  is installed on a bridge transportation path in the main body of the image forming apparatus. The bridge transportation path is a transportation path to transport the printing sheet to the finisher, and is a transportation path that branches from a main body transportation path at a position in a downstream side of the fuser  9 . 
       FIG. 2  shows a block diagram that indicates an electronic configuration of the image forming apparatus in the embodiment according to the present disclosure.  FIG. 3  shows a diagram that indicates an example of positions of covers and sensors installed on a housing of the image forming apparatus (including a main body, an option sheet feeding device, and a finisher) in the embodiment according to the present disclosure. 
     As shown in  FIGS. 2 and 3 , this image forming apparatus further includes a finisher inlet sensor  47 . The finisher inlet sensor  47  is an optical sensor that detects that the printing sheet  101 ,  102 ,  103  or  104  on the bridge transportation path reaches a predetermined position (i.e. installation position of the finisher inlet sensor  47 ) in a finisher mountable to and demountable from the main body of this image forming apparatus. The finisher inlet sensor  47  is installed on the bridge transportation path near a printing sheet inlet of the finisher. 
     Hereinafter the registration sensor, the transportation sensor, the bridge transportation sensor and the finisher inlet sensor are simply called as “sensor.” As mentioned, the sensors  42  to  47  are photoelectric sensors that are installed on the sheet transportation path of the printing sheet for printing sheet detection. Each of the sensors  42  to  47  is a reflection type sensor, and includes a light emitting unit that irradiates a predetermined position on the transportation path with a measurement light, and a light receiving unit that receives reflection light from the predetermined position and outputs an output signal corresponding to the received light amount. Therefore, when a printing sheet is located at the predetermined position, the received light amount gets large, otherwise the received light amount gets small. 
     Further, as shown in  FIGS. 2 and 3 , this image forming apparatus includes plural covers  51  to  56  installed on the housing, and plural cover lock units  51   a  to  53   a ,  55   a  and  56   a . The covers  51  to  56  are capable of being opened and closed. Each of the cover lock units  51   a  to  53   a ,  55   a  and  56   a  locks a predetermined cover among the plural covers  51  to  56  and unlocks the predetermined cover in accordance with a control signal. 
     The cover  51  is installed on a side face (upper side) of the main body, and the cover  52  is installed on a side face (lower side) of the main body. The cover  53  is installed on a side face of the option sheet feeding device. The cover  54  is installed over the bridge transportation path. The cover  55  is installed on a front face of the finisher. The covers  51  to  55  are covers for removing a printing sheet that stops on the transportation path due to jam or the like. The cover  56  is installed on a front face of the main body, and is a cover for replacement of the development devices  3   a  to  3   d  and/or the toner cartridges. 
     Each of the cover lock units  51   a  to  53   a ,  55   a  and  56   a  locks a predetermined cover among the plural covers  51  to  56  and unlocks the predetermined cover in accordance with a control signal. 
     For example, each of the cover lock units  51   a  to  53   a ,  55   a  and  56   a  includes an actuator that performs mechanically locking of the cover in accordance with the control signal. 
     In a status that the cover lock units  51   a  to  53   a ,  55   a  and  56   a  lock the covers  51  to  53 ,  55  and  56 , the covers  51  to  53 ,  55  and  56  are prevented from being opened and closed by a user or a service person; and in an unlock status of the covers  51  to  53 ,  55  and  56 , the covers  51  to  53 ,  55  and  56  can be opened and closed by a user or a service person. 
     Further, as shown in  FIG. 2 , this image forming apparatus includes a controller  61 , a storage device  62 , and an operation panel  63 . 
     The controller  61  includes a computer, an ASIC (Application Specific Integrated Circuit) and/or the like and thereby embodies sorts of processing units with software and/or hardware, watches and controls an internal device such as the printing device as shown in  FIG. 1  and performs sorts of data processing. The controller  61  controls an unshown driving source that drives the aforementioned rollers and the like, a bias circuit that induces a primary transfer bias, the development devices  3   a  to  3   d , the exposure devices  2   a  to  2   d  and the like, and thereby performs developing, transferring and fixing the toner image, feeding a paper sheet, printing on the paper sheet, and outputting the paper sheet. 
     Further, the controller  61  detects a trouble (printing sheet jam, toner empty, reaching usage limit of the development devices  3   a  to  3   d  or the like) of this image forming apparatus. Specifically, in order to control transportation of each printing sheet, the controller  61  determines whether a printing sheet is located at each of the predetermined positions on the transportation path of the printing sheet on the basis of the output signals of the sensors  42  to  47 , and thereby detects a printing sheet jam. Further, in a known manner, the controller  61  detects toner empty of the toner cartridge and detects reaching usage limit of the development device  3   a ,  3   b ,  3   c  and  3   d.    
     The storage device  62  is a nonvolatile storage device such as flash memory. In the storage device  62 , a programs, data and the like for the controller  61  are stored in advance. In this embodiment, in the storage device  62 , relationship data  81  is stored. 
     The operation panel  63  includes a display device (a liquid crystal display or the like) that displays an operation screen or the like to a user and an input device (touch panel, hard key and/or the like) that detects a user operation. 
     Further, the controller  61  acts as a login processing unit  71 , a maintenance processing unit  72 , and a lock control unit  73 . 
     The login processing unit  71  displays a login screen on the operation panel  63  and detects a user operation to input user authentication information (a user ID and a password) to the login screen with the operation panel  63 . Upon detecting the user authentication information, the login processing unit  71  performs user authentication on the basis of the inputted user authentication information. If the user authentication is succeeded, the login processing unit  71  displays on the operation panel  63  a menu screen to use sorts of functions of this image forming apparatus. A user whose user authentication is succeeded operates the menu screen and thereby uses the functions until the user logs out. 
     The maintenance processing unit  72  performs authentication of a service person on the basis of a specific operation (e.g. inputting a specific password or the like) to the operation panel  63 . If the authentication is succeeded, the maintenance processing unit  72  allows a maintenance operation instructed by the service person. If the authentication is succeeded, the maintenance processing unit  72  performs the maintenance operation (reading out a log, changing a setting item or the like) in accordance with an operation of the service person. 
     The lock control unit  73  controls the cover lock units  51   a  to  53   a ,  55   a  and  56   a  and thereby changes a status of the cover  51 ,  52 ,  53 ,  55  or  56  from one to the other among lock status and unlock status. 
     The aforementioned plural covers  51  to  53 ,  55  and  56  include one or more first covers, one or more second covers, and one or more third covers. The first cover (here, the cover  54 ) is a cover on which the cover lock unit  51   a ,  52   a ,  53   a ,  55   a  or  56   a  is not installed. The second cover (here, the covers  52 ,  53 ,  55  and  56 ) is a cover on which the cover lock unit  51   a ,  52   a ,  53   a ,  55   a  or  56   a  is installed and that a predetermined user and a service person are allowed to unlock. The third cover (here, the cover  51 ) is a cover on which the cover lock unit  51   a ,  52   a ,  53   a ,  55   a  or  56   a  is installed and that the service person is allowed to unlock. Further, the lock control unit  73  determines whether the lock control unit  73  unlocks the second cover or not on the basis of a user level of either a user who is in login status (i.e. login user) or an authenticated user (whose user authentication is succeeded after detecting a trouble). 
     The user level is determined on the basis of a user registration data (not shown) used in the user authentication. The user registration data includes user authentication information (a user ID and a password) and user level information on each registered user. The user registration data has been stored in the storage device  62  or a server (not shown), and is read out when required. 
     Further, the relationship data  81  is data that indicates a relationship between each second cover and a user level that allows to unlock this second cover. The relationship data  81  is stored in the storage device  62  in advance. The lock control unit  73  determines (a) a user level of either a user who is in login status or an authenticated user, (b) determines on the basis of the relationship data  81  the second cover that the determined user level allows to unlock, and (c 1 ) performs unlocking the determined second cover and (c 2 ) does not perform unlocking the second cover other than the second cover that the determined user level allows to unlock. 
     The following part explains a behavior of the aforementioned image forming apparatus.  FIG. 4  shows a flowchart that explains a behavior of the image forming apparatus shown in  FIGS. 1 to 3 . 
     Upon detecting a trouble (for example, a jam in a copy job or a jam in a print job) in this image forming apparatus (in Step S 1 ), the lock control unit  73  determines whether there is a user in a login status or not (in Step S 2 ); and if there is a user in a login status, then the lock control unit  73  determines a user level of the login user (in Step S 3 ), and locks all covers except for a cover that the determined user level allows to unlock among the covers  51  to  53 ,  55  and  56  using the cover lock units  51   a  to  53   a ,  55   a  and  56   a  (in Step S 4 ). Subsequently, on the operation panel  63 , the lock control unit  73  displays a message that indicates the aforementioned one or more covers in lock status (in Step S 5 ). 
     Contrarily, if there are no users in a login status when the trouble is detected (for example, when the trouble is detected in a print job requested from a remote host device), then the lock control unit  73  locks all the covers to  53 ,  55  and  56  (in Step S 6 ). Subsequently, on the operation panel  63 , the lock control unit  73  displays a message that indicates the aforementioned one or more covers in lock status (in Step S 5 ). 
     As mentioned, if there is a cover in lock status after the detection of the trouble, then controller  61  stops receiving a job request until the trouble is resolved. 
     The operation panel  63  displays a screen that includes the message that indicates one or more covers in lock status, and in this screen, an input field for inputting user authentication information and an input field for inputting service person authentication information are displayed together. 
     When user authentication information is inputted to the input field for inputting user authentication information by a user with the operation panel  63 , the lock control unit  73  performs user authentication based on the inputted user authentication information (in Step S 7 ); and if the user authentication is succeeded, then the lock control unit  73  determines a user level of the user and unlocks a cover that is in lock status and the determined user level allows to unlock among the covers  51  to  53 ,  55  and  56  using the cover lock unit  51   a  to  53   a ,  55   a  and  56   a  (in Step S 8 ). 
     When service person authentication information is inputted to the input field for inputting service person authentication information by a service person with the operation panel  63 , the lock control unit  73  performs service person authentication based on the inputted service person authentication information (in Step S 9 ); and if the service person authentication is succeeded, then the lock control unit  73  unlocks all covers that are in lock status among the covers  51  to  53 ,  55  and  56  using the cover lock unit  51   a  to  53   a ,  55   a  and  56   a  (in Step S 10 ). 
     Further, when the user or the service person finishes an operation for resolving the trouble, the controller  61  detects that the trouble has been resolved (in Step S 11 ), and terminates this process. 
     As mentioned, in the aforementioned embodiment, each of the cover lock units  51   a  to  53   a ,  55   a  and  56   a  locks a predetermined cover among the plural covers  51  to  56  and unlocks the predetermined cover in accordance with a control signal. The lock control unit  73  controls the cover lock units  51   a  to  53   a ,  55   a  and  56   a  and thereby changes a status of the cover  51 ,  52 ,  53 ,  55  or  56  from one to the other among lock status and unlock status. The aforementioned plural covers  51  to  53 ,  55  and  56  include one or more first covers, one or more second covers, and one or more third covers. The first cover is a cover on which the cover lock unit  51   a ,  52   a ,  53   a ,  55   a  or  56   a  is not installed (i.e. a cover that is not locked when a trouble is detected). The second cover is a cover on which the cover lock unit  51   a ,  52   a ,  53   a ,  55   a  or  56   a  is installed and that a predetermined user and a service person are allowed to unlock (i.e. a cover that is locked when a trouble is detected but allowed to be opened and closed by a specific user and a service person). The third cover is a cover on which the cover lock unit  51   a ,  52   a ,  53   a ,  55   a  or  56   a  is installed and that the service person is allowed to unlock (i.e. a cover that is locked when a trouble is detected and is not allowed to be opened and closed by any users but allowed to be opened and closed by a service person). Further, the lock control unit  73  determines whether the lock control unit  73  unlocks the second cover or not on the basis of a user level of either a user who is in login status or an authenticated user. 
     Consequently, locking and unlocking of the covers  51  to  53 ,  55  and  56  are properly performed when a trouble is detected. 
     The covers  51  to  53 ,  55  and  56  is classified in accordance with locations thereof into (a) a cover that there are no problems even if any user touches the inside through this cover, (b) a cover that there are no problems even if a user who is familiar to a structure of the apparatus touches the inside through this cover but it is favorable that a user who is not familiar to a structure of the apparatus does not touch the inside the inside through this cover and (c) a cover that it is favorable that no users touch the inside the inside through this cover. These covers are classified into the aforementioned first, second and third covers in advance, and a user who is not familiar to a structure of the apparatus and a user who is familiar to a structure of the apparatus are classified with the aforementioned user levels in advance, and thereby locking and unlocking of the covers  51  to  53 ,  55  and  56  are properly performed in accordance with locations of the covers and the user level when a trouble is detected. 
     It should be understood that various changes and modifications to the embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims. 
     For example, in the aforementioned embodiment, the cover  51  (i.e. a specific cover for removing a printing sheet that jams in the fuser  9 ) may be set as the second cover; and the lock control unit  73  may (a) not allow the user to unlock the cover  51  regardless of the user level and allows the service person to unlock the cover  51  if a temperature of the fuser  9  is equal to or higher than a predetermined value when a printing sheet jam occurs in the fuser  9 , and (b) allows the user to unlock the cover  51  in accordance with the user level and allows the service person to unlock the cover  51  if the temperature of the fuser  9  is lower than the predetermined value when a printing sheet jam occurs in the fuser  9 . The temperature of the fuser  9  is detected using a temperature sensor, for example. 
     Further, in the aforementioned embodiment, the user authentication and the service person authentication may be performed by an external authentication server (not shown). In such a case, the controller  61  (a) transmits the authentication information of a user or a service person to the authentication server using a network interface (not shown), and thereby causes the authentication server to perform the user authentication or the service person authentication, (b) receives an authentication result from the authentication server and if the authentication is succeeded, then receives a user level of the user together with the authentication result.