Patent Publication Number: US-11022925-B2

Title: Post-processing apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2019-009648, filed Jan. 23, 2019, the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to a post-processing apparatus and post-processing methods. 
     BACKGROUND 
     A post-processing apparatus performs a post-process on a sheet conveyed from an image forming apparatus. For example, the post-process is stapling. The post-processed sheet is discharged from an opening. When an object enters the opening, the post-processing apparatus may fail. However, in the post-processing apparatus, the occurrence of a failure is not prevented when an object enters the opening. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an external view showing an example of the overall configuration of an image forming system according to an embodiment; 
         FIG. 2  is a block diagram showing an example of the configuration of the image forming system; 
         FIG. 3  is a view showing an example of the configuration of a post-processing apparatus; 
         FIG. 4  is a view showing an example of arrangement of an object sensor; 
         FIG. 5  is a view showing a first example of an object detection order; 
         FIG. 6  is a view showing a second example of the object detection order; and 
         FIG. 7  is a flowchart showing an operation example of the image forming system. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments provide a post-processing apparatus capable of preventing the occurrence of a failure when an object enters an opening of the post-processing apparatus. 
     In general, according to one embodiment, a post-processing apparatus includes a first sensor, a second sensor, and a control unit. The first sensor detects an object in a predetermined area in which a predetermined post-process is performed on a sheet conveyed from an image forming apparatus. The second sensor detects an object at a position closer to an opening in the area than a position of the first sensor with respect to the opening through which the sheet passes when the post-processed sheet is discharged from the area. When the second sensor detects an object before the first sensor detects the object, the control unit performs a predetermined process for preventing the occurrence of a failure. 
     According to another embodiment, a post-processing method involves detecting an object at a first position in an area of a post-processing apparatus in which a predetermined post-process is performed on a sheet conveyed from an image forming apparatus; detecting the object at a second position closer than the first position to an opening in the area, the opening is an opening through which the sheet passes when the post-processed sheet is discharged from the area; and performing a predetermined process for preventing an occurrence of a failure when the object is detected at the second position before the object is detected at the first position. 
     Hereinafter, a post-processing apparatus of an embodiment will be described with reference to the drawings. 
       FIG. 1  is an external view showing an example of the overall configuration of an image forming system  1  according to an embodiment. The image forming system  1  includes an image forming apparatus  2  and a post-processing apparatus  3 . The image forming system  1  is a system for forming an image on a sheet-like recording medium. The image forming system  1  performs a post-process on a sheet-like recording medium. The post-process is, for example, sorting, stapling, or the like. 
     The image forming apparatus  2  is, for example, a multifunction peripheral or a printing apparatus. The image forming apparatus  2  includes a display  21 , a control panel  22 , a printer  23 , a sheet accommodating unit  24 , and an image reading unit  25 . The printer  23  of the image forming apparatus  2  may be an apparatus for fixing a toner image, or may be an ink jet apparatus. 
     The image forming apparatus  2  forms an image on a sheet using a developer such as toner. The sheet is, for example, paper or label paper. The sheet may be anything as long as it is a material on which the image forming apparatus  2  can form an image on the surface thereof. 
     The display  21  is an image display apparatus such as a liquid crystal display or an organic electro luminescence (EL) display. The display  21  displays various information items related to the image forming apparatus  2 . The various types of information are, for example, information indicating the number of sheets on which an image is formed, and message information transmitted from the post-processing apparatus  3 . The message information is, for example, information that warns that an object that enters inside the post-processing apparatus  3  is detected. The display  21  may include a speaker. The display  21  may output a warning sound from the speaker based on the message information indicating a warning. 
     The control panel  22  includes a plurality of buttons. The control panel  22  receives an operation input of a user. The control panel  22  outputs a signal in accordance with the operation by the user to a control unit of the image forming apparatus  2 . The display  21  and the control panel  22  may be integrally configured as a touch panel. 
     The printer  23  forms an image on a sheet based on the image information generated by the image reading unit  25 . The printer  23  may form an image on a sheet based on the image information (online data) received via a communication channel. For example, the printer  23  forms an image using the following process. The image forming unit of the printer  23  forms an electrostatic latent image on a photosensitive drum based on the image forming information. The image forming unit of the printer  23  causes a developer to adhere to the electrostatic latent image to form a visible image. An example of the developer includes toner. 
     A transfer unit of the printer  23  transfers the visible image to the sheet. A fixing unit of the printer  23  performs heating and pressurizing of the sheet to fix the transferred visible image on the sheet. The sheet in which the image is formed may be a sheet accommodated in the sheet accommodating unit  24  or a sheet manually supplied to the image forming apparatus  2 . The sheet accommodating unit  24  accommodates sheets to be used for image formation in the printer  23 . 
     The image reading unit  25  reads image information to be read based on the relative brightness and darkness thereof. The image reading unit  25  outputs the read image to the printer  23 . The image according to the read image information is formed on the sheet by the printer  23 . The image reading unit  25  may output the read image information to other information processing apparatus via the network. 
     The post-processing apparatus  3  is an apparatus that performs a post-process on a plurality of sheets conveyed from the image forming apparatus  2 . 
       FIG. 2  is a block diagram showing an example of the configuration of the image forming system  1  according to the embodiment. The image forming apparatus  2  includes the display  21 , the control panel  22 , the printer  23 , the sheet accommodating unit  24 , the image reading unit  25 , a sheet discharging unit  26 , an image forming control unit  27 , and an image forming communication unit  28 , and an image forming memory  29 . 
     A part or the entirety of the image forming control unit  27  and the image forming communication unit  28  is realized by software by causing a processor such as a central processing unit (CPU) to execute a program stored in the image forming memory  29 . For example, a part or the entirety of the image forming control unit  27  and the image forming communication unit  28  may be realized using hardware such as large scale integration (LSI). 
     The sheet discharging unit  26  conveys the sheet discharged from the printer  23  to the post-processing apparatus  3 . When the message information is transmitted from the post-processing apparatus  3  to the image forming apparatus  2 , the sheet discharging unit  26  may temporarily stop the process of conveying the sheet to the post-processing apparatus  3 . The image forming control unit  27  controls the operation of each component of the image forming apparatus  2 . For example, the image forming control unit  27  controls the printing operation of the printer  23 . 
     When the image forming apparatus  2  executes an online job, the image forming communication unit  28  receives image information via a communication channel. The image forming communication unit  28  outputs the received image information to the printer  23 . The image forming communication unit  28  receives the message information transmitted from the post-processing apparatus  3 . The message information indicates, for example, that an object enters an opening of the post-processing apparatus  3 . The image forming communication unit  28  outputs the message information to the image forming control unit  27 . The image forming communication unit  28  may output the message information to the display  21 . 
     The image forming memory  29  is, for example, a non-volatile recording medium (non-temporary recording medium) such as a flash memory. The image forming memory  29  stores, for example, an image forming program. The image forming memory  29  may include a volatile recording medium such as, for example, a dynamic random access memory (DRAM). 
     The post-processing apparatus  3  includes a fixed tray  31 , a movable tray  32 , a processing tray  33 , a post-processing control unit  34 , a post-processing communication unit  35 , and a post-processing memory  36 . A part or the entirety of the post-processing control unit  34  and the post-processing communication unit  35  is realized by software by causing a processor such as a CPU to execute an image forming program stored in the image forming memory  29 . Apart or the entirety of the post-processing control unit  34  and the post-processing communication unit  35  may be realized using hardware such as an LSI, for example. 
     The fixed tray  31  is a tray fixed to the upper portion of the post-processing apparatus  3 . The fixed tray  31  holds the sheet discharged from the post-processing apparatus  3  at the upper portion of the post-processing apparatus  3 . The movable tray  32  is a tray that moves upward or downward on the side surface of the post-processing apparatus  3 . The movable tray  32  holds the sheet discharged from the post-processing apparatus  3  on the side surface of the post-processing apparatus  3 . 
     The processing tray  33  (driving unit) is an area in the post-processing apparatus  3  where a post-process is performed on a sheet. The processing tray  33  may generate a bundle of sheets conveyed from the image forming apparatus  2  (hereinafter, referred to as “sheet bundle”). The processing tray  33  performs a post-process on the sheet bundle. The processing tray  33  includes a sheet sensor  331 , a post-processing section  332 , and a plurality of object sensors  333 . 
     The sheet sensor  331  (outlet sensor) is a sensor that detects a sheet conveyed from the image forming apparatus  2 . The object sensor  333  is, for example, a reflective type optical sensor. The sheet sensor  331  is provided in apart of the sheet conveyance path in the processing tray  33 . For example, the sheet sensor  331  is provided at a position where the sheet immediately after being conveyed from the image forming apparatus  2  can be detected in the sheet conveyance path of the processing tray  33 . 
     The post-processing section  332  (stapling unit) performs a post-process on the sheet bundle. The post-processing section  332  holds the sheet bundle until the post-processing is completed. The post-processed sheet bundle is discharged to the movable tray  32 . 
     The object sensor  333  is a sensor that detects an object, and is, for example, a reflective type optical sensor. The object to be detected is, for example, a hand. The plurality of object sensors  333  are arranged on a ceiling inside the processing tray  33  so as to be distributed in a predetermined range from a position close to the opening of the processing tray  33  to a position far from the opening. That is, the plurality of object sensors  333  are disposed on the ceiling inside the processing tray  33  so as to be distributed in a predetermined range from the downstream to the upstream of the sheet conveyance direction. Thus, when an object enters inside the processing tray  33 , the object sensor  333  can detect the entered object. 
     The post-processing control unit  34  controls the operation of each functional unit of the post-processing apparatus  3 . For example, the post-processing control unit  34  controls the operation of sheet conveyance processing in the post-processing apparatus  3 . The post-processing control unit  34  controls the post-process operation performed by the post-processing section  332 . 
     The post-processing control unit  34  determines whether or not an object enters inside the processing tray  33  based on the order in which the respective object sensors  333  detect the object. When the downstream object sensor  333  in the sheet conveyance direction in the processing tray  33  detects an object before the upstream object sensor  333  detects the object in the processing tray  33 , the post-processing control unit  34  determines that the object enters inside the processing tray  33 . When the post-processing control unit  34  determines that the object enters inside the processing tray  33 , the post-processing control unit  34  stops (cancels) the processing by the post-processing section  332 . Further, the post-processing control unit  34  may stop the conveyance process in progress when it is determined that the object enters inside the processing tray  33 . With these controls, the post-processing control unit  34  can reduce the possibility of occurrence of a failure due to the object entered inside the processing tray  33 . Further, the post-processing control unit  34  may generate message information indicating a warning when it is determined that the object enters inside the processing tray  33 . The post-processing control unit  34  restarts the post-process by the post-processing section  332  when the predetermined release condition is satisfied. The predetermined release condition is, for example, a condition that a predetermined time elapses since no object is detected inside the processing tray  33 . 
     The post-processing communication unit  35  transmits the generated message information to the image forming communication unit  28 . The post-processing memory  36  is, for example, a non-volatile recording medium (non-temporary recording medium) such as a flash memory. The post-processing memory  36  stores, for example, a post-processing program. The post-processing memory  36  may include a volatile recording medium such as a DRAM. 
       FIG. 3  is a view showing an example of the configuration of the processing tray  33  according to the embodiment. The xyz axes are shown in  FIG. 3  to simplify the description. In  FIG. 3 , the conveyance direction of a sheet  100  is the negative direction of the x-axis direction. An opening  33   a  is provided on the negative side of the x-axis direction in the processing tray  33 . That is, the opening  33   a  is provided on the downstream side of the processing tray  33  in the conveyance direction of the sheet  100 . A height “H 1 ” of the opening  33   a  represents a distance from a ceiling surface  33   b  (first reference surface) of the processing tray  33  to a floor surface  33   c  (second reference surface). The width of the provided opening  33   a  is equal to or greater than the width of a sheet bundle  100   a.    
     A holding area  330  is provided in the processing tray  33 . The sheet bundle  100   a  is a bundle of sheets  100 . The processing tray  33  generates the sheet bundle  100   a  in the holding area  330 . The generated sheet bundle  100   a  is held in the holding area  330 . A height “H 2 ” of the holding area  330  represents the height according to the thickness and the maximum number of sheets  100 . That is, the height “H 2 ” of the holding area  330  represents the maximum height of the sheet bundle  100   a  with respect to the floor surface  33   c.  The maximum number of sheets of the sheet bundle  100   a  is, for example, 50. 
     The object sensor  333  detects an object at a position at a predetermined height or higher from the floor surface  33   c . In  FIG. 3 , the focus of each object sensor  333  is set so that an object at a position at the height “H 2 ” of the holding area  330  or higher inside the processing tray  33  can be detected. Thus, the object sensor  333  can detect an object in a range of the height “H 2 ” or higher from the floor surface  33   c  and the height “H 1 ” or lower from the floor surface  33   c.    
     The sheet bundle  100   a  is held in the holding area  330  until a predetermined number of sheets  100  are bundled, and is then conveyed to the post-processing section  332 . The post-processing section  332  performs a post-process on the sheet bundle  100   a.  The post-processed sheet bundle  100   a  is discharged to the movable tray  32  from the opening  33   a.    
       FIG. 4  is a view showing an example of arrangement of the object sensor  333  according to the embodiment. The xyz axes are shown in  FIG. 4  to simplify the description. The number of object sensors  333  is not limited to nine as illustrated in  FIG. 4  as long as the number is two or more. In  FIG. 4 , a total of nine object sensors  333  in three rows in the x-axis direction and three rows in the y-axis direction are disposed on the ceiling inside the processing tray  33 . 
     The plurality of object sensors  333  may be transmission type light sensors. The plurality of transmission type light sensors may be arranged so that the light emitting side and the light receiving side face each other in the y-axis direction (horizontal direction) inside the processing tray  33 . Furthermore, the plurality of transmission type light sensors may be arranged at positions where the light emitting side and the light receiving side are higher than the height “H 2 ” inside the processing tray  33 . When the object sensor  333  is a transmission type light sensor, some of the members of the processing tray  33  may be provided with a hole for transmitting the light of the transmission type light sensor. 
       FIG. 5  is a view showing a first example of an object detection order according to the embodiment. In the example shown in  FIG. 5 , the object does not enter inside the processing tray  33  through the opening  33   a.  In this case, the object sensor  333  arranged at a position far from the opening  33   a  detects the sheet  100  before the object sensor  333  arranged at a position close to the opening  33   a  detects the sheet  100 . That is, each object sensor  333  detects the sheet  100  being conveyed in the conveyance direction in order from the upstream object sensor  333  to the downstream object sensor  333 . When such a detection order result is obtained, the post-processing control unit  34  continues a normal conveyance process in progress. 
     In  FIG. 5 , an object sensor  333 - 1  detects the sheet  100  conveyed into the detection range of the object sensor  333 - 1  at time t 1  before an object sensor  333 - 2  detects the sheet  100  conveyed in the detection range of the object sensor  333 - 2 . The object sensor  333 - 2  detects the sheet  100  conveyed into the detection range of the object sensor  333 - 2  at time t 2  before an object sensor  333 - 3  detects the sheet  100  conveyed in the detection range of the object sensor  333 - 3 . The object sensor  333 - 3  detects the sheet  100  conveyed in the detection range of the object sensor  333 - 3  at time t 3 . 
     The object sensor  333 - 1  does not detect the sheet  100  conveyed outside the detection range of the object sensor  333 - 1  at time t 4  before the object sensor  333 - 2  does not detect the sheet  100  conveyed outside the detection range of the object sensor  333 - 2 . The object sensor  333 - 2  does not detect the sheet  100  conveyed outside the detection range of the object sensor  333 - 2  at time t 5  before the object sensor  333 - 3  does not detect the sheet  100  conveyed outside the detection range of the object sensor  333 - 3 . The object sensor  333 - 3  does not detect the sheet  100  conveyed outside the detection range of the object sensor  333 - 3  at time t 6 . 
       FIG. 6  is a view showing a second example of the object detection order according to the embodiment. In the example shown in  FIG. 6 , the object enters inside the processing tray  33  through the opening  33   a.  In this case, the object sensor  333  arranged at a position close to the opening  33   a  detects the object before the object sensor  333  arranged at a position far from the opening  33   a  detects the object. That is, each object sensor  333  detects the object that enters inside the processing tray  33  in order of the downstream object sensor  333  and the upstream object sensor  333 . 
     When the result of such detection order is obtained, the post-processing control unit  34  stops the normal conveyance process in progress. As a result, the post-processing control unit  34  can reduce the possibility of occurrence of a failure due to the entry of the object into the processing tray  33 . 
     When the post-processing control unit  34  stops the normal conveyance process in progress, the post-processing communication unit  35  transmits message information representing a warning to the image forming communication unit  28  based on transmission processing control by the post-processing control unit  34 . An image of the message information representing a warning is displayed on the display  21 . The post-processing communication unit  35  may transmit message information representing a warning to an information processing terminal that transmits the image information to the image forming apparatus  2 . 
     In  FIG. 6 , before the object sensor  333 - 2  detects the object that enters in the detection range of the object sensor  333 - 2 , the object sensor  333 - 3  detects the object moved in the detection range of the object sensor  333 - 3  at the time t 1 . The object sensor  333 - 2  detects the object moved in the detection range of the object sensor  333 - 2  at the time t 2  before the object sensor  333 - 3  detects the object that enters in the detection range of the object sensor  333 - 3 . The object sensor  333 - 1  detects the object moved in the detection range of the object sensor  333 - 1  at the time t 3 . 
     The object sensor  333 - 3  does not detect the object moved outside the detection range of the object sensor  333 - 3  at the time t 4  before the object sensor  333 - 2  does not detect the object that enters outside the detection range of the object sensor  333 - 2 . Before the object sensor  333 - 3  does not detect the object that enters outside the detection range of the object sensor  333 - 3 , the object sensor  333 - 2  does not detect the object moved outside the detection range of the object sensor  333 - 2  at the time t 5 . At the time t 6 , the object sensor  333 - 1  does not detect the object moved outside the detection range of the object sensor  333 - 1 . 
     Next, an operation example of the image forming system  1  will be described. 
       FIG. 7  is a flowchart showing an operation example of the image forming system  1  according to the embodiment. The post-processing control unit  34  determines whether or not the downstream object sensor  333  in the conveyance direction of the sheet  100  detects the object (ACT  101 ). When the object sensor  333  other than the downstream object sensor detects the object (ACT  101 : NO), the post-processing control unit  34  determines whether or not the object sensor  333  detects the object in order from the upstream side to the downstream side (ACT  102 ). 
     When it is determined that the object sensor  333  detects the object in order from the upstream side to the downstream side (ACT  102 : YES), the post-processing control unit  34  continues the normal conveyance process in progress (ACT  103 ). The post-processing control unit  34  ends the process of the flowchart shown in  FIG. 7 . 
     When it is determined that the object sensor  333  detects the object in order other than the order from the upstream side to the downstream side (in random order) (ACT  102 : NO), the post-processing control unit  34  returns the process to ACT  101 . 
     When the downstream object sensor  333  detects the object (ACT  101 : NO), the post-processing control unit  34  determines whether or not the object sensor  333  detects the object in order from the downstream to the upstream (ACT  104 ). When it is determined that the object sensor  333  detects an object in order other than the order from the downstream side to the upstream side (in random order) (ACT  104 : NO), the post-processing control unit  34  returns the process to ACT  101 . 
     When it is determined that the object sensor  333  detects an object in order from the downstream side to the upstream side (ACT  104 : YES), the post-processing control unit  34  stops the conveyance process in progress. The post-processing communication unit  35  transmits the message information to the image forming communication unit  28  (ACT  105 ). The post-processing control unit  34  ends the process shown in the flowchart of  FIG. 7 . 
     As described above, the post-processing apparatus  3  according to the embodiment includes a first object sensor  333 , a second object sensor  333 , and the post-processing control unit  34 . The first object sensor  333  is provided on the processing tray  33 . The processing tray  33  is an area where a predetermined post-process is performed on the sheet bundle  100   a.  The post-processed sheet  100  passes through the opening  33   a  when the sheet is discharged from the processing tray  33 . The first object sensor  333  detects an object in the processing tray  33 . The second object sensor  333  detects an object at a position closer to the opening  33   a  in the processing tray  33  than the position of the first object sensor  333  with respect to the opening  33   a.  When the second object sensor  333  detects the object before the first object sensor  333  detects the object, the post-processing control unit  34  performs a predetermined process for preventing the occurrence of a failure. The predetermined process for preventing the occurrence of failure is, for example, a process of stopping a conveyance process of the sheet  100  halfway, a process of displaying a warning message on the display  21  of the image forming apparatus  2 , a process of outputting a warning sound from at least one of the image forming apparatus  2  and the post-processing apparatus  3 , or the like. 
     According to at least one embodiment described above, it is possible to prevent the occurrence of a failure when an object enters the opening of the post-processing apparatus. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.