Patent Publication Number: US-11383539-B2

Title: Unit attaching/detaching structure and image forming system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2019-011558 filed Jan. 25, 2019. 
     BACKGROUND 
     (i) Technical Field 
     The present disclosure relates to a unit attaching/detaching structure and an image forming system. 
     (ii) Related Art 
     In a grounding structure of a unit disclosed in JP-A-2014-194506, the unit is detachable while preventing a ground spring interposed between the two units from being projected. 
     In the related art, in a configuration in which a unit attachable to and detachable from the apparatus main body is provided, the apparatus main body is provided with a displacement portion that is displaced by attaching the detached unit on the apparatus main body, and a detection unit that detects attachment of the unit with respect to the apparatus main body by displacing the displacement portion. Further, when the unit is attached to the apparatus main body, the unit is provided with a movement portion that directly comes into contact with the displacement portion to displace the displacement portion. 
     Thus, when the unit is brought close to the apparatus main body in an attempt to attach the unit on the apparatus main body, if a position of the unit deviates from a target position, the movement portion of the unit may come into contact with the detection unit, which may cause damage to the detection unit. 
     SUMMARY 
     Aspects of non-limiting embodiments of the present disclosure relate to preventing damage to a detection unit when a unit is attached to an apparatus main body in contrast to case where a movement portion of the unit directly displaces a displacement portion of the apparatus main body. 
     Aspects of certain non-limiting embodiments of the present disclosure address the above advantages and/or other advantages not described above. However, aspects of the non-limiting embodiments are not required to address the advantages described above, and aspects of the non-limiting embodiments of the present disclosure may not address advantages described above. 
     According to an aspect of the present disclosure, there is provided a unit attaching/detaching structure, including: a unit that is attachable to and detachable from an apparatus main body; a displacement portion that is provided on the apparatus main body and is displaceable to one side and another side; a detection unit that detects attachment of the unit when the displacement portion is displaced from the another side to the one side; a connecting portion that is separated from the detection unit in a direction intersecting with a direction of attaching/detaching of the unit, and is connected to the displacement portion so as to displace the displacement portion to be moved; a movement portion that is provided on the unit and displaces the displacement portion from the another side to the one side by moving the connecting portion when the unit is attached to the apparatus main body; and a returning unit that returns the displacement portion from the one side to the another side when the unit is detached from the apparatus main body. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the present invention will be described in detail based on the following figures, wherein: 
         FIG. 1  is a perspective view illustrating a detection unit and a cantilevered portion provided in an apparatus main body of a unit attaching/detaching structure according to an exemplary embodiment of the present disclosure; 
         FIGS. 2A and 2B  are an enlarged perspective view illustrating the detection unit and the cantilevered portion provided in an apparatus main body of a unit attaching/detaching structure according to an exemplary embodiment of the present disclosure; 
         FIG. 3  is a perspective view illustrating a charge removal plate and the like provided in an output unit of the unit attaching/detaching structure according to the exemplary embodiment of the present disclosure; 
         FIG. 4  is a perspective view illustrating the output unit of the unit attaching/detaching structure according to the exemplary embodiment of the present disclosure; 
         FIG. 5  is a perspective view illustrating the output unit of the unit attaching/detaching structure according to the exemplary embodiment of the present disclosure; 
         FIG. 6  is a perspective view illustrating an apparatus main body of the unit attaching/detaching structure according to the exemplary embodiment of the present disclosure; 
         FIG. 7  is a perspective view illustrating an image forming system according to an exemplary embodiment of the present disclosure; 
         FIG. 8  is a configuration diagram illustrating an image forming system according to an exemplary embodiment of the present disclosure; and 
         FIG. 9  is a configuration diagram illustrating an image forming system according to an exemplary embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     An example of a unit attaching/detaching structure and an image forming system according to the exemplary embodiment of the present disclosure will be described with reference to  FIGS. 1 to 9 . Note that, in the drawings, an arrow H indicates a vertical direction of the apparatus (=vertical direction), an arrow W indicates an apparatus width direction (an example of a horizontal direction), and an arrow D indicates an apparatus depth direction (another example of the horizontal direction). 
     Overall Configuration 
     An image forming system  10  according to the exemplary embodiment is provided with, as illustrated in  FIGS. 8 and 9 , an image forming apparatus  12 , an apparatus main body  12   a  of an output unit  60  that is attachable to and detachable from the image forming apparatus  12 . 
     As illustrated in  FIGS. 8 and 9 , in the image forming apparatus  12 , an accommodating portion  14  in which a sheet member P as a recording medium is accommodated, a transport unit  16  that transports the sheet member P accommodated in the accommodating portion  14 , and an image forming unit  20  that performs image-forming on the sheet member P transported from the accommodating portion  14  by the transport unit  16  are provided in this order, from the lower side to the upper side in vertical direction (=direction of arrow H). Further, the image forming apparatus  12  is provided with a manual feed portion  24  in which the sheet member P can be supplied from the outside of the apparatus main body  12   a.    
     Note that, a side plate  64  being in contact with the output unit  60  attached to the apparatus main body  12   a , and the like will be specifically described later. 
     Accommodating Portion  14   
     The accommodating portion  14  is provided with an accommodating member  26  that can be pulled out from the apparatus main body  12   a  of the image forming apparatus  12  in an apparatus width direction (=left direction in the drawings), and the sheet members P are stacked on the accommodating member  26 . The accommodating portion  14  is further provided with a feeding roll  30  for feeding the sheet member P stacked on the accommodating member  26  to a transport path  22  constituting the transport unit  16 . 
     Transport Unit  16   
     The transport unit  16  is provided with plural transport rolls  32  for transporting the sheet member P along the predetermined transport path  22 , and a transport roll  34  for transporting the sheet member P along a reversed path  28  through which the sheet member P passes to reverse the front and back of the sheet member P. 
     In addition, the transport unit  16  is provided with a transport roll  46  for transporting the sheet member P along a supply path  54  through which the sheet member P supplied from a manual feed portion  24  passes. 
     In the transport path  22 , a part on the upstream side and a part on the downstream side in the transport direction of the sheet member P are formed into a U shape. That is, the sheet member P is folded in the transport direction in the U shape and then output to the outside of the apparatus main body  12   a.    
     In addition, the transport unit  16  is provided with an output path  62  which is branched from the part on the downstream side of the transport direction of the sheet member P in the transport path  22 , and outputs the sheet member P to the outside of the apparatus main body  12   a  without folding the sheet member P into the U shape. 
     Image Forming Unit  20   
     The image forming unit  20  includes an image forming unit  18  that forms a black image. 
     The image forming unit  18  is provided with an image holding member  36 , a charging roll  38  for charging the surface of the image holding member  36 , and an exposure device  42  for irradiating the charged image holding member  36  with exposure light. Further, the image forming unit  20  is provided with a developing machine  40  for developing an electrostatic latent image formed by exposing the image holding member  36  charged by the exposure device  42  to visualize the electrostatic latent image as a toner image. 
     Further, the image forming unit  20  is provided with a transfer roll  44  for transferring the toner image formed by the image forming unit  18  to the sheet member P at a transfer position T where the image is transferred to the sheet member P, and a fixing device  50  that fixes the toner image to the sheet member P by heating and pressing the sheet member P. 
     Output Unit  60   
     The output unit  60  is attachable to and detachable from the apparatus main body  12   a , Then, the sheet member P transported along the output path  62  is output to the output unit  60 . 
     The output unit  60  and a detection mechanism  66  for detecting that the output unit  60  is attached to the apparatus main body  12   a  will be described in detail later. 
     Action of Image Forming Apparatus 
     The image forming apparatus  12  forms an image as follows. 
     First, the charging roll  38  to which a voltage is applied comes into contact with the surface of the image holding member  36  to negatively charge the surface of the image holding member  36  uniformly at a predetermined potential. Subsequently, the exposure device  42  irradiates the charged surface of the image holding member  36  with exposure light to form an electrostatic latent image based on data input from the outside. 
     With this, the electrostatic latent image corresponding to the data is formed on the surface of the image holding member  36 . Further, the developing machine  40  develops and visualizes the electrostatic latent image as a toner image. 
     Then, the sheet member P fed from the accommodating member  26  to the transport path  22  by the feeding roll  30  is transported to the transfer position T. At the transfer position T, the sheet member P is sandwiched and transported by the image holding member  36  and the transfer roll  44 , thereby the toner image on the surface of the image holding member  36  is transferred to the sheet member P. 
     The toner image transferred to the sheet member P is fixed to the sheet member P by the fixing device  50 . Then, the sheet member P on which the toner image is fixed is transported along the transport path  22 , folded back in a U-shape, and output to the upper part of the apparatus main body  12   a.    
     On the other hand, when the sheet member P on which the toner image is fixed by the fixing device  50  is output to the output unit  60 , the sheet member P on which the toner image is fixed is transported along the output path  62  branched from the transport path  22 , and is output to the output unit  60  without being folded back in a U-shape. 
     Configuration of Main Components 
     Next, the side plate  64  of the apparatus main body  12   a , the output unit  60 , and the detection mechanism  66  (refer to  FIG. 1 ) for detecting that the output unit  60  is attached to the apparatus main body  12   a  will be described. The output unit  60  is an example of a unit. 
     Side Plate  64  of Apparatus Main Body  12   a    
     As illustrated in  FIGS. 8 and 9 , the side plate  64  is disposed on the downstream side of the transport direction in which the plate surface facing the apparatus width direction and the sheet member P having the toner image transferred at the transfer position T is transported. 
     As illustrated in  FIG. 6 , the side plate  64  is provided with an output hole  64   a  through which the sheet member P output from the apparatus main body  12   a  passes, and positioning recessed portions  64   b  and  64   c  for positioning the output unit  60  with respect to the apparatus main body  12   a . The side plate  64  is further provided with an insertion hole  64   d  for inserting a part of a transmission gear  98  described later into the apparatus main body  12   a , and a detection hole  64   e  into which a detection convex portion  72   e  described later is inserted. 
     The output hole  64   a  is formed in a part on the center side in the vertical direction of the side plate  64 . Further, the output hole  64   a  is formed into a rectangular shape extending in the apparatus depth direction as viewed from the apparatus width direction. 
     The positioning recessed portions  64   b  are formed in a pair separately in the apparatus depth direction, at a part on the upper side of the output hole  64   a  in the side plate  64 . Further, each positioning recessed portion  64   b  is rectangular when viewed from the apparatus width direction. 
     The positioning recessed portions  64   c  are formed in a pair separately in the apparatus depth direction, at a part on the lower side of the output hole  64   a  in the side plate  64 . Further, each positioning recessed portion  64   c  is rectangular when viewed from the apparatus width direction. 
     The insertion hole  64   d  is formed in a part on the front side in the apparatus depth direction with respect to the output hole  64   a  in the side plate  64 . Further, the insertion hole  64   d  is formed into a rectangular shape extending in the vertical direction as viewed from the apparatus width direction. 
     The detection hole  64   e  is formed in a part on the back side in the apparatus depth direction of the side plate  64  between the output hole  64   a  and the positioning recessed portion  64   b  in the vertical direction. Further, the detection hole  64   e  is rectangular when viewed from the apparatus width direction. 
     Output Unit  60   
     The output unit  60  is a unit that can be selectively used by the user, and as illustrated in  FIGS. 6 and 7 , is attachable to and detachable from the apparatus main body  12   a , and is in contact with the side plate  64  of the apparatus main body  12   a  in a state of being attached to the apparatus main body  12   a , Note that the state in which the output unit  60  is attached to the apparatus main body  12   a ″ means a state that the sheet member P can be output from the apparatus main body  12   a  to the output unit  60  when the user designates output of the sheet member P to the output unit  60 . 
     As illustrated in  FIG. 5 , the output unit  60  is provided with a unit main body portion  70  in contact with the side plate  64  (refer to  FIG. 7 ) of the apparatus main body  12   a , and an output plate  76  on which the sheet member P output from the apparatus main body  12   a  is placed. Further, output unit  60  is provided with an output roll  78 , a pressing roll  82 , a charge removal brush  86 , and a charge removal plate  88 . The output roll  78  is an example of a transport unit, 
     Unit Main Body Portion  70   
     As illustrated in  FIGS. 4 and 5 , the unit main body portion  70  extends in the apparatus depth direction, and has a hollow inside. Further, the unit main body portion  70  is provided with a pair of protruding portions  70   a  protruding in the apparatus width direction from both end portions of the unit main body portion  70  in the apparatus depth direction, and an intermediate portion  70   h  sandwiched between the pair of the protruding portions  70   a . In addition, on the apparatus main body  12   a  side of the pair of protruding portions  70   a  and the intermediate portion  70   b , a facing plate  72  which constitutes the unit main body portion  70  and faces the side plate  64  of the apparatus main body  12   a  is disposed. 
     As illustrated in  FIG. 4 , the facing plate  72  is provided with a passage hole  72   a  through which the sheet member P output from the apparatus main body  12   a  passes, and a pair of positioning convex portions  72   b  and a pair of positioning convex portions  72   c  for positioning the output unit  60  with respect to the apparatus main body  12   a . Further, the facing plate  72  is provided with an exposure hole  72   d  for exposing a portion of a transmission gear  98  described later to the outside, and a detection convex portion  72   e  inserted in the detection hole  64   e  (refer to  FIG. 6 ). 
     The detection convex portion  72   e  has a rectangular cross section, and a rectangular end surface  74  is formed at the end of the detection convex portion  72   e . Further, at both end portions of the end surface  74  in the apparatus depth direction, a pair of protruding portions  74   a  extending in the vertical direction is formed. 
     In this configuration, by moving the output unit  60  detached from the apparatus main body  12   a  in the apparatus width direction, the pair of positioning convex portions  72   h  of the facing plate  72  are respectively inserted into the recessed portions  64   b  (refer to  FIG. 6 ) of the side plate  64 . Further, the pair of positioning convex portions  72   c  of the facing plate  72  are respectively inserted into the recessed portions  64   c  (refer to  FIG. 6 ) of the side plate  64 . As a result, the output unit  60  is positioned with respect to the apparatus main body  12   a , and the output unit  60  is attached to the apparatus main body  12   a  (hereinafter, referred to as “attached state of the output unit  60 ”). The apparatus width direction is an example of the attaching/detaching direction of the unit. 
     Further, in the attached state of the output unit  60 , the passage hole  72   a  of the facing plate  72  faces the output hole  64   a  (refer to  FIG. 6 ) of the side plate  64 , and the detection convex portion  72   e  is inserted into the detection hole  64   e  (refer to  FIG. 6 ). The unit main body portion  70  is provided with a maintenance mechanism (not shown) for maintaining the attached state of the output unit  60  in the attached state of the output unit  60 . 
     Output Plate  76   
     As illustrated in  FIG. 5 , the output plate  76  is formed into a plate shape, is disposed between the pair of protruding portions  70   a  in the unit main body portion  70 , and is inclined with respect to the horizontal direction. Further, the output plate  76  is formed into a rectangular shape when viewed from a plate thickness direction. 
     Output Roll  78  and Pressing Roll  82   
     As illustrated in  FIG. 5 , the output roll  78  is disposed in the unit main body portion  70  and is provided with a metal shaft  78   a  extending in the apparatus depth direction and plural resin roll portions  78   b  through which the shaft  78   a  penetrates and is disposed spaced apart in the apparatus depth direction. The output roll  78  is further provided with a pair of metal bearings  78   c  disposed at both end portions of the shaft  78   a  in the apparatus depth direction. 
     The pressing roll  82  is disposed on the upper side of the roll portion  78   b  and is in contact with the roll portion  78   b  in the vertical direction. The pressing roll  82  is integrally formed of a roll portion and a shaft portion with a resin material, is rotatably supported by a support member (not shown) to press the sheet member P sandwiched between the output roll  78  and the pressing roll  82  against the output roll  78  side. 
     In this configuration, the output roll  78  is rotated by the transmission of a rotational force, and the pressing roll  82  is rotated following the rotation of the output roll  78 . Then, the output roll  78  sandwiches the sheet member P output from the apparatus main body  12   a  with the pressing roll  82  to transport, and outputs the sheet member P to the output plate  76 . 
     Charge Removal Brush  86   
     As illustrated in  FIG. 5 , the charge removal brush  86  is disposed in the unit main body portion  70 , and is on the downstream side of the output roll  78  and the pressing roll  82  in the transport direction of the sheet member P. The charge removal brush  86  is provided with a metal plate material  86   a  and a brush-like metal brush material  86   b.    
     The plate material  86   a  extends to the apparatus depth direction, and the plate surface of the plate material  86   a  faces the apparatus width direction. In addition, the plate material  86   a  is formed into a rectangular shape extending to the apparatus depth direction when viewed from the plate thickness direction, and is disposed in the same range as the shaft  78   a  of the output roll  78  in the apparatus depth direction. 
     The brush material  86   b  protrudes downward from the lower edge of the plate material  86   a  and extends in the vertical direction. In addition, the plural brush materials  86   b  are provided at intervals in the apparatus depth direction. 
     In this configuration, a part on the end side (=lower end side) of the brush material  86   b  is in contact with the sheet surface of the sheet member P transported by the output roll  78 . 
     Charge Removal Plate  88   
     The charge removal plate  88  is formed by bending a trimmed sheet metal, and is, as illustrated in  FIG. 5 , disposed on the back side of the output roll  78  and the charge removal brush  86  in the apparatus depth direction. The charge removal plate  88  is an example of the movement portion. 
     As illustrated in  FIGS. 3 and 5 , the charge removal plate  88  is provided with a main body portion  90  extending in the apparatus width direction, and a connecting portion  92  connected to the apparatus main body  12   a  of the main body portion  90 . Further, the charge removal plate  88  is provided with a connecting portion  94  connected to a part on the side opposite to the side to which the connecting portion  92  is connected in the main body portion  90  and a connecting portion  96  connected to a part on the central side of the main body portion  90  in the apparatus width direction. 
     The main body portion  90  is formed into a step shape as viewed from the apparatus depth direction, and is provided with a first portion  90   a , a second portion  90   b , and a third portion  90   c , which are arranged in this order from the apparatus main body  12   a  side. The first portion  90   a  and the third portion  90   c  are formed into a rectangular shape in which the plate surface faces in the vertical direction and extends in the apparatus width direction as viewed from the plate thickness direction. The second portion  90   b  is formed into a rectangular shape in which the plate surface faces in the apparatus width direction and extends in the vertical direction as viewed from the plate thickness direction. 
     The connecting portion  92  is connected to an edge portion of the first portion  90   a  of the main body portion  90  on the apparatus main body  12   a  side, and protrudes upward from the first portion  90   a . Further, the connecting portion  92  is formed into a rectangular shape in which the plate surface faces in the apparatus width direction as viewed from the plate thickness direction. In addition, the connecting portion  92  is provided with a protruding portion  92   a  that protrudes in a curved surface shape from the plate surface toward the apparatus main body  12   a.    
     Further, as illustrated in  FIG. 4 , the connecting portion  92  and the first portion  90   a  of the main body portion  90  protrude from the facing plate  72  toward the apparatus main body  12   a , and the connecting portion  92  is in contact with the end surface  74  of the detection convex portion  72   e  at a surface. In this state, the connecting portion  92  is disposed between the pair of protruding portions  74   a  in the apparatus depth direction, and the protruding end of the protruding portion  92   a  of the connecting portion  92  protrudes toward the apparatus main body  12   a  with respect to the protruding portion  74   a.    
     As illustrated in  FIGS. 3 and 5 , the connecting portion  94  is connected to the edge portion on the side opposite to the apparatus main body  12   a  in the third portion  90   c  of the main body portion  90 , and protrudes downward from the third portion  90   c . Further, the connecting portion  94  is formed into a rectangular shape in which the plate surface faces in the apparatus width direction as viewed from the plate thickness direction. The connecting portion  94  is in contact with a part on the back side in the apparatus depth direction in the plate material  86   a  of the charge removal brush  86  at a surface. In this way, the charge removal plate  88  is electrically connected to the charge removal brush  86 . 
     The connecting portion  96  is connected to the edge portion of the second portion  90   b  of the main body portion  90  on the back side in the apparatus depth direction and protrudes downward from the second portion  90   b . Further, the connecting portion  96  is formed into a step shape in which the plate surface faces in the apparatus depth direction as viewed from the plate thickness direction. The connecting portion  96  is in contact with one of the bearings  78   c  of the output roll  78 . In this way, the charge removal plate  88  is electrically connected to the output roll  78 . 
     Others 
     As illustrated in  FIG. 4 , a transmission gear  98  for transferring a rotational force to the output roll  78  is attached to an end portion on the side opposite to the side on which the charge removal plate  88  is disposed in the shaft  78   a  of the output roll  78 . In addition, as described above, a portion of the transmission gear  98  protrudes to the outside from the exposure hole  72   d  of the facing plate  72 . 
     In this configuration, in the attached state of the output unit  60 , a portion of the transmission gear  98  exposed from the exposure hole  72   d  is inserted into the insertion hole  64   d  (refer to  FIG. 6 ) of the side plate  64 , and the transmission gear  98  engages with a drive gear (not shown). With this, the rotational force is transmitted to the output roll  78  via the transmission gear  98  so that the output roll  78  is rotated. 
     Detection Mechanism  66   
     The detection mechanism  66  is disposed inside the apparatus main body  12   a  as illustrated in  FIG. 1 , and is provided with a detection unit  102  and a detection plate  106 . 
     Detection Unit  102   
     The detection unit  102  is an optical sensor, and is formed into a. U-shaped with the lower side opened as viewed in the apparatus width direction, and is provided with a pair of separated portions  102   a  separated in the apparatus depth direction. With this, a space  104  is formed between the pair of the separated portions  102   a . In addition, light is emitted from one separated portion  102   a  to the space  104 , and the light emitted from the one separated portion  102   a  is incident on other separated portion  102   a.    
     Detection Plate  106   
     The detection plate  106  is formed by bending a trimmed sheet metal, and is provided with, as illustrated in  FIG. 1 , a displacement portion  108  which is displaced so as to be inserted into and removed from the space  104  and a cantilever-like cantilevered portion  110  extending in the vertical direction and being fixed to the apparatus main body  12   a  at the upper end portion. Further, the detection plate  106  is provided with a strip-like strip portion  114  extending in the apparatus depth direction, having the displacement portion  108  connected to one end and the cantilevered portion  110  connected to the other end. The cantilevered portion  110  is an example of the connecting portion. 
     In the displacement portion  108 , the plate surface is directed in the apparatus width direction, and at least a portion thereof is disposed in the space  104 . 
     The cantilevered portion  110  is disposed apart from the displacement portion  108  in an intersecting direction (corresponding to the apparatus depth direction) which intersects with an attaching/detaching direction (corresponding to the apparatus width direction) of the output unit  60 . Specifically, the cantilevered portion  110  is disposed at the back side in the apparatus depth direction with respect to the displacement portion  108 , and extends in the vertical direction. 
     The cantilevered portion  110  is a plate spring and is formed into a step shape as viewed from the apparatus depth direction, and formed into a rectangular shape extending in the vertical direction as viewed from the apparatus width direction. Further, a base portion  110   a  whose plate surface is directed in the apparatus width direction is provided on the upper end part of the cantilevered portion  110 , and an end portion  110   b  whose plate surface is directed in the apparatus width direction and is disposed on the side plate  64  side with respect to the base portion  110   a  is provided on the lower end part of the cantilevered portion  110 . Note that, a plate spring is a spring using energy absorption by elastic deformation of bending of metal plates such as spring steel, and energy discharge by restoration. 
     The base portion  110   a  is formed into a rectangular shape as viewed from the plate thickness direction, and is fixed to a metal frame member  120  provided on the apparatus main body  12   a  and grounded, by a metal fixture  122 . In this way, the detection plate  106  is attached to the frame member  120  by fixing the base portion  110   a  to the frame member  120 . Further, the end portion Hob is formed into a rectangular shape when viewed from a plate thickness direction. 
     As such, by fixing the base portion  110   a  to the frame member  120 , the cantilevered portion  110  extending in the vertical direction is in a cantilever state in which the base portion  110   a  is at the support end and the end portion  110   b  is at the free end. In the cantilever state, one end side of the member is fixed, and the other end side is displaceable freely. 
     Further, the end portion  110   b  overlaps the detection hole  64   e  formed in the side plate  64  as viewed in the apparatus depth direction. 
     In this configuration, when the output unit  60  is attached to the apparatus main body  12   a  from the state where the output unit  60  is detached from the apparatus main body  12   a  (hereinafter, referred to as the detached state of the output unit  60 ″), the detection convex portion  72   e  of the output unit  60  is inserted into the detection hole  64   e  of the side plate  64 . As illustrated in  FIGS. 2A and 2B , the end portion  110   b  of the cantilevered portion  110  comes into contact with the protruding portion  92   a  formed on the connecting portion  92  of the charge removal plate  88  and is pushed by the output unit  60  (refer to  FIG. 4 ) to one side (corresponding to the left side in the drawing) in the apparatus width direction. By pressing the end portion  110   b , the cantilevered portion  110 , which is a plate spring, on the end portion  110   b  side (corresponding to the free end side) moves to one side in the apparatus width direction (corresponding to the left side in the drawing) with the fixed base portion  110   a  so as to be elastically deformed. Further, the contact between the protruding portion  92   a  formed on the connecting portion  92  of the charge removal plate  88  and the end portion  110   b  of the cantilevered portion  110  allows the charge removal plate  88  and the detection plate  106  to be electrically connected to each other. 
     Further, when the output unit  60  is detached from the attached state of the output unit  60 , the end portion  110   b  of the cantilevered portion  110  is separated from the protruding portion  92   a  formed on the connecting portion  92  of the charge removal plate  88 . When the end portion  110   b  is separated from the protruding portion  92   a , the cantilevered portion  110 , which is a plate spring on the end portion  110   b  side, moves to the other side in the apparatus width direction (corresponding to the right side in the drawing) to be elastically returned. 
     As illustrated in  FIG. 1 , the strip portion  114  is disposed below the detection unit  102  in the vertical direction, and extends from the displacement portion  108  to the end portion  110   b  of the cantilevered portion  110  in the apparatus depth direction. In other words, the strip portion  114  is disposed at a position that does not interfere with the detection unit  102  even if the strip portion  114  moves in the apparatus width direction. 
     Further, the plate surface of the strip portion  114  is directed in the vertical direction, and the strip portion  114  is formed into a rectangular shape extending in the apparatus depth direction as viewed from the plate thickness direction. 
     Then, when the end portion  110   b  of the cantilevered portion  110  moves, the displacement portion  108  is displaced in an interlocking manner. That is, the strip portion  114  functions as an interlocking unit that interlocks the displacement portion  108  with the movement of the cantilevered portion  110 . 
     Further, the displacement portion  8  is connected to a part on the one end side of the strip portion  114 , and the end portion  110   b  of the cantilevered portion  110  is connected to a part on the other end side of the strip portion  114  so that the cantilevered portion  110  is separated from the detection unit  102  as viewed from the apparatus depth direction. In other words, in the apparatus depth direction, a portion of the strip portion  114  overlaps the detection unit  102 , and another portion of the strip portion  114  is disposed at a position different from the detection unit  102 . 
     As described above, the strip portion  114  functions as a separation unit that separates the cantilevered portion  110  and the detection unit  102  from each other when viewed in the apparatus depth direction. 
     In this configuration, in the detached state of the output unit  60 , as illustrated in  FIG. 2A , a part on one side of the displacement portion  108  in the apparatus width direction is disposed in the space  104  of the detection unit  102 . Then, the light emitted from one of the separated portion  102   a  is incident on the other separated portion  102   a.    
     On the other hand, when the output unit  60  is attached to the apparatus main body  12   a  from the detached state of the output unit  60 , the detection convex portion  72   e  of the output unit  60  is inserted into the detection hole  64   e  of the side plate  64 . As illustrated in  FIG. 2B , the end portion  110   b  of the cantilevered portion  110  comes into contact with the protruding portion  92   a  formed on the connecting portion  92  of the charge removal plate  88  and is pushed by the output unit  60  to one side in the apparatus width direction. As a result, the end portion  110   b  moves to one side in the apparatus width direction, and the cantilevered portion  110  is elastically deformed. 
     The displacement portion  108  is displaced to one side in the apparatus width direction as the end portion  110   b  is moved to one side in the apparatus width direction. Then, most of the displacement portion  108  is disposed in the space  104  of the detection unit  102 . With this, the light emitted from one of the separated portion  102   a  is blocked by the displacement portion  108  and is not incident on the other separated portion  102   a . In this manner, the detection unit  102  detects that the output unit  60  has been attached to the apparatus main body  12   a.    
     As described above, the unit attaching/detaching structure  100  includes the output unit  60 , the displacement portion  108 , the detection unit  102 , the cantilevered portion  110 , and the charge removal plate  88  and is configured such a the output unit  60  is attachable to and detachable from the apparatus main body  12   a.    
     Action of Main Component Configuration 
     Next, the action of the unit attaching/detaching structure  100  will be described. Specifically, a case where the output unit  60  is attached to the apparatus main body  12   a  from the detached state of the output unit  60  and a case where the output unit  60  is detached from the apparatus main body  12   a  from the attached state of the output unit  60  will be described. 
     Case where Output Unit  60  is Attached to Apparatus Main Body  12   a    
     In the detached state of the output unit  60 , as illustrated in  FIG. 2A , a part on one side of the displacement portion  108  in the apparatus width direction is disposed in the space  104  of the detection unit  102 . With this, the light emitted from one of the separated portion  102   a  is incident on the other separated portion  102   a . In this manner, the detection unit  102  detects the detached state of the output unit  60 . 
     Further, when the output unit  60  is attached to the apparatus main body La by moving the output unit  60  to one side in the apparatus width direction from the detached state of the output unit  60 , the detection convex portion  72   e  (refer to  FIG. 4 ) of the output unit  60  is inserted into the detection hole  64   e  (refer to  FIG. 6 ) of the side plate  64 . 
     When the detection convex portion  72   e  is inserted into the detection hole  64   e , as illustrated in  FIG. 2B , the front end portion  110   b  of the cantilevered portion  110  contacts the protruding portion  92   a  formed on the connecting portion  92  of the charge removal plate  88  and is pushed by the Output unit  60  to one side in the apparatus width direction. As a result, the end portion  110   b  moves to one side in the apparatus width direction, and the cantilevered portion  110  is elastically deformed. 
     The displacement portion  108  is displaced to one side in the apparatus width direction as the end portion  110   b  is moved to one side in the apparatus width direction. Then, most of the displacement portion  108  is disposed in the space  104  of the detection unit  102 . With this, the light emitted from one of the separated portion  102   a  is blocked by the displacement portion  108  and is not incident on the other separated portion  102   a . In this manner, the detection unit  102  detects that the output unit  60  has been attached to the apparatus main body  12   a.    
     Further, in the attached state of the output unit  60 , the rotational force is transmitted from the apparatus main body  12   a  side to the output roll  78  via the transmission gear  98 , thereby the output roll  78  is rotated. Then, the output roll  78  to be rotated sandwiches the sheet member P output from the apparatus main body  12   a  with the pressing roll  82  to transport, and outputs the sheet member P to the output plate  76  (refer to  FIG. 5 ). 
     In addition, the brush material  86   h  of the charge removal brush  86  as illustrated in  FIG. 5  comes into contact with the sheet surface of the sheet member P transported by the output roll  78 , and the charge removal brush  86  discharges the sheet member P. 
     Here, due to the frictional force generated between the output roll  78  and the sheet member P, the frictional charge generated on the shaft  78   a  of the output roll  78  is suppressed by electrically connecting the charge removal plate  88  and the cantilevered portion  110 . Similarly, due to the frictional force generated between the charge removal brush  86  and the sheet member P, the frictional charge generated on the charge removal brush  86  is suppressed by electrically connecting the charge removal plate  88  and the cantilevered portion  110 . 
     Case where Output Unit  60  is Detached from Apparatus Main Body  12   a    
     In the attached state of the output unit  60 , as illustrated in  FIG. 2B , most of the displacement portion  108  is disposed in the space  104  of the detection unit  102 . 
     Further, when the output unit  60  is detached from the apparatus main body  12   a  by moving the output unit  60  to the other side in the apparatus width direction from the attached state of the output unit  60 , the detection convex portion  72   e  (refer to  FIG. 4 ) of the output unit  60  is removed from the detection hole  64   e  (refer to  FIG. 6 ) of the side plate  64 . 
     When the detection convex portion  72   e  is removed from the detection hole  64   e , the end portion  110   b  of the cantilevered portion  110  is separated from the protruding portion  92   a  formed in the connecting portion  92  of the charge removal plate  88 . When the end portion  110   b  of the cantilevered portion  110  is separated from the connecting portion  92  of the charge removal plate  88 , as illustrated in  FIG. 2A , the end portion  110   b  moves to the other side in the apparatus width direction so that the cantilevered portion  110  is elastically returned. 
     The displacement portion  108  is displaced to the other side in the apparatus width direction as the end portion  110   b  is moved to the other side in the apparatus width direction. Then, a part on one side of the displacement portion  108  in the apparatus width direction is disposed in the space  104  of the detection unit  102 . With this, the light emitted from one of the separated portion  102   a  is incident on the other separated portion  102   a . In this manner, the detection unit  102  detects that the output unit  60  has been detached from the apparatus main body  12   a.    
     SUMMARY 
     As described above, when the output unit  60  is attached to the apparatus main body  12   a , the cantilevered portion  110  in contact with the charge removal plate  88  of the output unit  60  is separated from the detection unit  102  in the apparatus depth direction. Therefore, damage to the detection unit  102  is suppressed when the output unit  60  is attached to the apparatus main body  12   a , as compared with the case where the charge removal plate directly displaces the displacement portion  108 . 
     The cantilevered portion  110  is a plate spring, and when the output unit  60  is attached to the apparatus main body  12   a , the cantilevered portion  110  comes into contact with the charge removal plate  88  and is pressed to be elastically deformed. On the other hand, when the output unit  60  is detached from the apparatus main body  12   a , the cantilevered portion  110  is separated from the charge removal plate  88  to be elastically returned. In this way, by using the cantilevered portion  110  as a plate spring, for example, the cantilevered portion  110  is moved with a simple configuration as compared with the case where the cantilevered portion is moved to one side and the other side using an actuator. 
     Further, the cantilevered portion  110  is in a cantilever state, and the free end side of the cantilevered portion  110  is connected to the displacement portion  108  via the strip portion  114 . For this reason, the cantilevered portion  110  is miniaturized as compared with the case where the support end side of the cantilevered portion is connected to the displacement portion. 
     Further, the contact between the charge removal plate  88  of the output unit  60  and the cantilevered portion  110  allows the cantilevered portion  110  to be electrically connected to the apparatus main body  12   a . As a result, the number of parts is reduced as compared with the case where members for electrically connecting the cantilevered portion to the apparatus main body  12   a  are separately provided. 
     The output roll  78  and the charge removal brush  86  are electrically connected to the apparatus main body  12   a  so that the output roll  78  and the charge removal brush  86  are grounded. As a result, the number of parts is reduced as compared with the case where the members for grounding the output roll  78  and the charge removal brush  86  are separately provided. 
     Further, in the image forming system  10 , the attached state of the output unit  60  is detected with high accuracy by suppressing the damage of the detection unit  102  as compared with the case where the charge removal plate directly displaces the displacement portion  108 . 
     Note that the present disclosure has been described in detail with respect to the specific exemplary embodiment; however, it is clear for the person skilled in the art that the present disclosure is not limited to the exemplary embodiment, and various other exemplary embodiments can be employed within the scope of the present disclosure. In the above exemplary embodiment, the cantilevered portion  110  and the displacement portion  108  are separated from each other in the apparatus depth direction; however, the direction may be the intersecting direction which intersects with the attaching/detaching direction corresponding to the apparatus width direction) of the output unit  60 , for example, it may be the vertical direction. 
     Further, in the above exemplary embodiment, a transmissive optical sensor is used as the detection unit  102 ; however, a reflective optical sensor may be used, or a mechanical sensor or the like that mechanically detects the displacement of the displacement portion  108  may be used. 
     Further, in the above exemplary embodiment, the output roll  78  and the charge removal brush  86  are grounded by the contact between the charge removal plate  88  of the output unit  60  and the cantilevered portion  110 ; however, when the charge removal plate  88  and the cantilevered portion  110  come into contact with each other, for example, power may be supplied to a member provided in the output unit, or an electrical signal may flow. 
     In the above exemplary embodiment, the cantilevered portion  110  is a plate spring; however, it may be a member that moves by being pushed by the output unit  60 , and may be, for example, a rubber member that expands and contracts in the apparatus width direction. 
     Further, although not particularly described in the above exemplary embodiment, for example, the cantilevered portion may include a combination of a plate material and a compression spring. 
     Further, although not particularly described in the above exemplary embodiment, the displacement portion  108  may be a member constituting the detection unit  102 . 
     The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.