JP6667404B2 - Medium separation device, medium supply device, and image forming system - Google Patents

Description

  The present invention relates to an image forming system for forming an image on a medium, and a medium separating device and a medium supplying device mounted on the image forming system.

  Some image forming apparatuses such as a copying machine, a printer, and a facsimile have an external medium supply device. Such a medium supply device includes a medium separation device that sequentially separates and extracts one medium from a plurality of stacked media (for example, see Patent Document 1).

U.S. Pat. No. 7,850,163

  By the way, in such a medium separation device, it is desired that smooth medium separation be performed regardless of the type of medium.

  Therefore, it is desirable to provide a medium separation device capable of exhibiting excellent medium separation performance, a medium supply device provided with such a medium separation device, and an image forming system.

  A first medium separation device as one embodiment of the present invention includes a stacker that stacks and holds a plurality of media and a separation unit that separates the plurality of media one by one. The separation unit has a moving body, a biasing member, and a contact member. The moving body conveys the medium in the first direction by moving in the first direction. The urging member contacts the moving body via the medium in the second direction, and applies an urging force to the medium to urge the medium toward the moving body. The contact member is provided so as to be movable along the second direction so as to approach or move away from the moving body, and to be in contact with a medium passing between the moving body and the urging member. Including planes. The urging force of the urging member varies according to the position of the contact member in the second direction with respect to the position of the moving body.

A first medium supply device as one embodiment of the present invention includes the first medium separation device and a medium conveyance device that conveys the medium separated in the medium separation device.
Further, a first image forming system as one embodiment of the present invention includes the first medium supply device and an image forming device.

  In the first medium separation device, the first medium supply device, and the first image forming system according to an embodiment of the present invention, the urging force of the urging member for holding the medium between the moving body and the first medium separation device is the second medium separation device. In the direction indicated by the arrow in FIG. For this reason, the urging member is displaced in the second direction in conjunction with the contact member, and can apply an auxiliary conveyance force to the medium according to a change in the separation load. The change in the separation load is caused, for example, by a change in the position of the contact member in the second direction. Therefore, an appropriate relationship between the separation load and the transporting force can be obtained regardless of the remaining amount of the medium without performing complicated control. Feeding (an event in which a plurality of media are conveyed while overlapping) is avoided. The “separation load” refers to, for example, a force required when one medium is separated by a contact member from a plurality of stacked media. The “conveying force” refers to a force for conveying one medium to be separated in a first direction, and is generated by, for example, a moving body and an urging member.

  A second medium separation device as one embodiment of the present invention includes a stacker that stacks and holds a plurality of media and a separation unit that separates the plurality of media one by one. The separation unit has a moving body, a contact member, a first cam, and a locking portion. The moving body conveys the medium in the first direction by moving in the first direction. The contact member is provided so as to be movable along the second direction so as to approach or move away from the moving body, and includes a contact surface that comes into contact with a medium conveyed by the moving body. The first cam moves the contact member along the second direction so as to approach or move away from the moving body. The locking portion locks the first cam in two or more postures.

A second medium supply device as one embodiment of the present invention includes the above-described second medium separation device and a medium conveyance device that conveys the medium separated in the medium separation device.
Further, a second image forming system as one embodiment of the present invention includes the second medium supply device and an image forming device.

  In the second medium separation device, the second medium supply device, and the second image forming system according to an embodiment of the present invention, the first cam that moves the contact member along the second direction is locked. The part locks in two or more positions. Accordingly, the contact member is locked at an arbitrary position in the second direction, so that the gap between the contact member and the moving body can be easily adjusted. Accordingly, an appropriate separation load is obtained by the urging member in accordance with the position of the contact member in the second direction, and non-feeding of the medium and damage to the medium (the occurrence of curling and wrinkling) are avoided.

  According to the medium separation device, the medium supply device, and the image forming system as one embodiment of the present disclosure, excellent medium separation performance can be exhibited.

FIG. 1 is a schematic diagram illustrating an overall configuration example of an image forming system according to a first embodiment of the present invention. FIG. 2 is an enlarged front view illustrating a main part of the medium separation device illustrated in FIG. 1. FIG. 2 is an enlarged plan view illustrating a main part of the medium separation device illustrated in FIG. 1. FIG. 2 is another front view illustrating a main part of the medium separation device illustrated in FIG. 1 in an enlarged manner. FIG. 4B is a front view illustrating a part of FIG. 4A in a further enlarged manner. FIG. 9 is a characteristic diagram schematically illustrating a relationship between a total weight of a medium, a conveying force, and a separation load in a medium separation device as a reference example having a general structure. FIG. 2 is a characteristic diagram schematically illustrating a relationship between an overlap amount, a conveying force, and a separation load in the medium separation device illustrated in FIG. 1. FIG. 9 is a schematic diagram illustrating an overall configuration example of a medium separation device according to a second embodiment of the present invention. FIG. 7 is a side view of the separation unit shown in FIG. 6 as viewed from a downstream side. It is the side view which expanded the principal part of the separation unit shown in FIG. FIG. 7 is a perspective view illustrating an appearance of a separation unit illustrated in FIG. 6. FIG. 7 is a perspective view illustrating an internal structure of a separation unit illustrated in FIG. 6. FIG. 7 is a cross-sectional view illustrating an internal structure of a separation unit illustrated in FIG. 6. FIG. 7 is a perspective view illustrating an internal structure of a separation unit illustrated in FIG. 6. FIG. 7 is another perspective view illustrating the internal structure of the separation unit illustrated in FIG. 6. FIG. 7 is a perspective view for explaining an operation of the separation unit shown in FIG. 6. FIG. 7 is a side view for explaining the operation of the separation unit shown in FIG. 6. It is the expanded side view which expanded a part of FIG. 10B. FIG. 7 is a characteristic diagram schematically illustrating a relationship between a ratchet position and a gap in the separation unit illustrated in FIG. 6. FIG. 7 is a perspective view illustrating a first modification of the separation section illustrated in FIG. 6. FIG. 13 is a perspective view illustrating a second modification of the separation section illustrated in FIG. 6. FIG. 7 is a cross-sectional view illustrating a second modification of the separation section illustrated in FIG. 6. FIG. 13 is a perspective view for explaining an operation of the separation unit shown in FIG. 6 in a second modification. FIG. 13 is another perspective view for explaining the operation of the separation section shown in FIG. 6 in a second modification. FIG. 13 is a characteristic diagram schematically illustrating a relationship between a ratchet position and a gap in a second modification of the separation unit illustrated in FIG. 6.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description is a specific example of the present invention, and the present invention is not limited to the following embodiments. Further, the present invention is not limited to the arrangement, dimensions, dimensional ratios, and the like of the components shown in the drawings. The description will be made in the following order.
1. First Embodiment (Medium Separation Apparatus Having Stepless Gap Adjustment Mechanism, and Medium Supply Apparatus and Image Forming System on Which It Is Mounted)
1.1 Overall Configuration of Image Forming System 1.2 Detailed Configuration of Medium Supply Device 1.3 Detailed Configuration of Image Forming Device 1.4 Effects of Image Forming System Second Embodiment (Medium Separation Apparatus Having Multi-Stage Gap Adjustment Mechanism)
2.1 Detailed Configuration of Medium Separation Device 2.2 Functions and Effects 2.3 First Modified Example 2.4 Second Modified Example 3. Other modifications

<1. First Embodiment>
[1.1 Overall Configuration of Image Forming System]
FIG. 1 schematically illustrates an example of the entire configuration of an image forming system according to a first embodiment of the present invention. This image forming system corresponds to a specific example of the “image forming system” of the present invention, and includes a medium supply device S1 and an image forming device S2. The medium supply device S1 corresponds to a specific example of the “medium supply device” of the present invention, and includes a medium separation device S11, a medium conveyance device S12, a control unit SS1, and a drive motor S1M. The medium separation device S11 corresponds to a specific example of the “medium separation device” of the present invention, and includes a stacker 2020 that stacks and holds a plurality of media PM1, and a separation unit that separates the plurality of media PM1 one by one. And 10. The medium transporting device S12 is located downstream of the medium separating device S11, and transports the medium PM1 separated by the medium separating device S11 to the image forming device S2 located downstream thereof. In the present specification, when an arbitrary position is set as a reference, a direction from the position toward the stacker 2020 or a position closer to the stacker 2020 than the position is referred to as upstream or rearward, and a direction away from the position to the stacker 2020. Alternatively, a position farther from the stacker 2020 than that position is referred to as downstream or forward. In this image forming system, the stacker 2020 is the most upstream. Further, the control unit SS1 performs overall control of the medium supply device S1 in cooperation with the control unit SS2 (described later) in the image forming apparatus S2. The drive motor S1M functions as a drive source for the later-described sheet feeding / conveying unit 2010 or the medium conveying device S12 based on a command from the control unit SS1.

[1.2 Detailed Configuration of Medium Supply Apparatus S1]
FIG. 2 is an enlarged front view illustrating a main part of the medium separation device S11. However, FIG. 2 also illustrates some components of the medium transport device S12. FIG. 3 is an enlarged plan view illustrating a main part of the medium separation device S11. In the present specification, the transport direction of the transported medium PM1 is referred to as an X-axis direction (one specific example corresponding to the “first direction” of the present invention). Further, the width direction of the medium PM1 perpendicular to the X-axis direction is referred to as a Z-axis direction (one specific example corresponding to the “third direction” of the present invention), and the direction perpendicular to the surface of the medium PM1 is referred to. It is referred to as a Y-axis direction (one specific example corresponding to the “second direction” of the present invention).

  The medium separation device S11 further includes a bridge 2005 in addition to the stacker 2020 and the separation unit 10 described above. The stacker 2020 and the separation unit 10 are arranged adjacent to each other with the bridge 2005 interposed therebetween. The stacker 2020 and the separation unit 10 are attached to the bridge 2005, respectively.

(Configuration of Stacker 2020)
The stacker 2020 includes, for example, a bottom plate 2020S that supports a plurality of stacked media PM1 from below, a stack guide 2021 that guides rear ends of the stacked media PM1, and a set guide that guides side edges of the media PM1. 2022.

(Configuration of the separation unit 10)
The separation unit 10 includes a separation unit 2001 and a sheet feeding / conveying unit 2010.

(Separation unit 2001)
The separation unit 2001 includes a separation frame 2002, a separator 2003, a knob 2004, a separator frame 2006, a guide shaft 2007, an elastic body 2008, an auxiliary roller 2009, a roller frame 2023, and a support unit 2025. ing. The separation frame 2002 is fixed to the bridge 2005 via the connection portion 2024, and holds the support portion 2025 movably along the Y-axis direction as indicated by an arrow Y2025 (FIG. 2). The separation frame 2002 is a specific example corresponding to the “base” of the present invention. The knob 2004 is held on the separation frame 2002 so as to be rotatable in the + R4 direction and the −R4 direction around the axis J4 as shown in FIG. 2, and is used to operate the movement of the support portion 2025 in the Y-axis direction. Functions as an operation unit. The support portion 2025 is a member extending in the Y-axis direction, and moves in the + Y direction by rotating the knob 2004 in the + R direction, and moves in the -Y direction by rotating the knob 2004 in the -R direction. I have. When the support portion 2025 moves in the + Y direction, part or all of the support portion 2025 is housed inside the separation frame 2002. On the other hand, when the support portion 2025 moves in the −Y direction, part or all of the support portion 2025 housed inside the separation frame 2002 is exposed outside the separation frame 2002 (the side opposite to the knob 2004). Becomes A separator frame 2006 is connected to a tip of the support portion 2025, that is, an end opposite to the separation frame 2002. A separator 2003 is provided on a side of the separator frame 2006 opposite to the support portion 2025. The separator 2003 and the separator frame 2006 are one specific example corresponding to the “contact member” of the present invention. The separator 2003 is provided so as to face the sheet feeding / conveying unit 2010, and has a contact surface 2003S that comes into contact with the medium PM1 during the medium separating operation in the medium separating device S11. With such a configuration, the support portion 2025, the separator frame 2006, and the separator 2003 are integrally movable with the rotation of the knob 2004 in the + Y direction or the −Y direction. In this embodiment, the + Y direction may be expressed as an upward direction, and the −Y direction may be expressed as a downward direction.

  In the separator frame 2006, an auxiliary roller 2009 is provided upstream of the separator 2003 and downstream of the stacker 2020 via a guide shaft 2007 and a roller frame 2023. The guide shaft 2007 is held by the separator frame 2006 so as to be movable along the Y-axis direction as indicated by an arrow Y7 (FIG. 2). The roller frame 2023 is attached to the tip of the guide shaft 2007. An elastic body 2008 such as a coil spring is provided between the separator frame 2006 and the roller frame 2023. The guide shaft 2007, the elastic body 2008, the roller frame 2023, and the auxiliary roller 2009 correspond to one specific example of the "biasing member" of the present invention as a whole, and extend along the Y-axis direction with respect to the separator 2003. It is held by the separator frame 2006 so as to be elastically displaced. One end of the elastic body 2008 contacts a part of the separator frame 2006, and the other end of the elastic body 2008 contacts a part of the roller frame 2023. The elastic body 2008 urges the separator frame 2006 and the roller frame 2023 in the Y-axis direction so as to separate them (in a direction away from them). The auxiliary roller 2009 is held by a roller frame 2023 so as to be rotatable about an axis J9 extending in the Z-axis direction. The auxiliary roller 2009 is opposed to the surface 2011S (described later) of the sheet feeding belt 2011 (described later) of the sheet feeding / conveying unit 2010, and attaches the elastic body 2008 to the medium separating operation in the medium separating device S11. It is in a state of being constantly urged by the force so as to head toward the surface 2011S of the sheet feeding belt 2011 via the medium PM1. That is, at the time of the medium separation operation in the medium separation device S11, the medium PM1 is sandwiched between the auxiliary roller 2009 and the front surface 2011S, and the auxiliary roller 2009 rotates with the rotation of the sheet feeding belt 2011, so that the medium PM1 is rotated. It is to be transported downstream.

  Further, the biasing force of the elastic body 2008 or the like varies according to the position of the separator 2003 with respect to the position of the paper feed belt 2011 in the Y-axis direction. During the medium separation operation, the auxiliary roller 2009 is in a state of facing the surface 2011S of the paper feed belt 2011 with the medium PM1 interposed therebetween, and the positional relationship between the auxiliary roller 2009 and the surface 2011S is substantially constant. On the other hand, the separator 2003 does not directly or indirectly contact the surface 2011S of the sheet feeding belt 2011 as described later, and the height position of the contact surface 2003S is lower than the height position of the surface 2011S. Can be displaced. Therefore, when the separator 2003 (separator frame 2006) is displaced downward, the elastic body 2008 is compressed and the urging force is increased. When the separator 2003 (separator frame 2006) is displaced upward, the elastic body 2008 is relaxed and the urging force is increased. Decline. In the present embodiment, one separator 2003 for one separator frame 2006, a pair of guide shafts 2007A and 2007B, a pair of elastic bodies 2008, a pair of roller frames 2023A and 2023B, and a pair of auxiliary rollers 2009A and 2009B. (See FIG. 3 described later).

(Sheet feeding unit 2010)
The sheet feeding / conveying section 2010 is located below the stacker 2020 and the separating section 2001, and includes, for example, a sheet feeding belt 2011, a medium sensor 2012, a driving roller 2013, and a stretching roller 2014. FIG. 3 illustrates a plan configuration of the sheet feeding / conveying unit 2010 viewed from the separating unit 2001. In the paper feeder 2010, as shown in FIGS. 2 and 3, a plurality of paper feed belts 2011 (2011A to 2011F) are arranged at predetermined intervals in the Z-axis direction. The paper feed belt 2011 is a specific example corresponding to the “moving body” of the present invention. In the example illustrated in FIG. 3, paper feed belts 2011A to 2011C are disposed on the left of an axis 2010Z that represents the center of the paper feed unit 2010 in the Z-axis direction, and paper feed belts 2011D to 2011F are disposed on the right of the axis 2010Z. However, the present invention is not limited to this. Each of the paper feed belts 2011A to 2011F is an endless belt member stretched by one drive roller 2013 extending in the Z-axis direction and one stretch roller 2014 extending in the Z-axis direction. The driving roller 2013 receives the driving force of the driving motor S1M driven according to the control of the control unit SS1, and is driven to rotate in the direction of arrow R13 (FIG. 2). The paper feed belts 2011A to 2011F rotate and rotate in the direction indicated by the arrow R11 by the rotation of the drive roller 2013. The tension roller 2014 is driven to rotate by frictional force with the paper feed belts 2011A to 2011F. The medium sensor 2012 detects whether or not the medium PM1 is loaded on the stacker 2020.

  In the present embodiment, as described above, in the separator 2001, one separator 2003 for one separator frame 2006, a pair of guide shafts 2007A and 2007B, a pair of elastic bodies 2008, and a pair of roller frames 2023A and 2023B. And a pair of auxiliary rollers 2009A and 2009B (see FIG. 3). Here, the separator 2003 is located at the center of the sheet feeding / conveying unit 2010 in the Z-axis direction, that is, between the adjacent sheet feeding belts 2011C and 2011D. Therefore, even when the sheet moves in the Y-axis direction, the contact surface 2003S of the separator 2003 does not interfere with the sheet feeding belt 2011. Therefore, as shown in FIGS. 4A and 4B, the separator 2003 can move in the −Y direction to a position where the separator 2003 overlaps (overlaps) with the sheet feeding belt 2011 in the Z-axis direction. 4A is a schematic diagram illustrating a state in which the separator 2003 and the sheet feeding belt 2011 overlap, and FIG. 4B is an enlarged view illustrating a part of FIG. 4A. In the present embodiment, as shown in FIG. 4B, the height position (position in the Y-axis direction) of the contact surface 2003S of the separator 2003 at the foremost 2003SS and the height position (the position of the surface 2011S of the sheet feeding belt 2011). The difference (overlapping dimension) from the position (the position in the Y axis direction) is defined as the overlap amount L.

  The guide shaft 2007A, the elastic body 2008 (not shown in FIG. 3), the roller frame 2023A, and the auxiliary roller 2009A are provided at positions corresponding to, for example, the paper feed belt 2011C in the Y-axis direction. On the other hand, the guide shaft 2007B, the elastic body 2008 (not shown in FIG. 3), the roller frame 2023B, and the auxiliary roller 2009B are provided at positions corresponding to the sheet feeding belt 2011D in the Y-axis direction. That is, the auxiliary roller 2009A and the auxiliary roller 2009B are arranged so as to face each other with one separator 2003 interposed therebetween in the Z-axis direction. Therefore, at the time of the medium separation operation in the medium separation device S11, the medium PM1 is moved between the paper feeding belt 2011C and the auxiliary roller 2009A and between the paper feeding belt 2011D and the auxiliary roller 2009B by the urging force of the elastic body 2008. Each is to be sandwiched.

(Configuration of Bridge 2005)
Further, the bridge 2005 has a stacking guide 2027 that comes into contact with the front end surfaces of the plurality of stacked media PM1 (see FIG. 1), and a pre-separation guide 2026 located below the stacking guide 2027. The loading guide 2027 includes, for example, a flat surface extending in the Y-axis direction, whereas the pre-separation guide 2026 includes a curved surface that gradually approaches the separation unit 2001. The pre-separation guide 2026 functions so as to advance slightly in the + X direction (downstream) as the plurality of media PM1 moves downward (approaching the paper feed belt 2011). The bridge 2005 corresponds to a specific example of the “guide unit” of the present invention.

(Configuration of the medium transport device S12)
As shown in FIG. 2, the medium transport device S12 includes, for example, a transport belt 2031, a drive roller 2032, a transport table 2033, a plurality of transport rollers 2034, media sensors 2035, 2036, and a stretching roller 2037. Have. The transport table 2033 is a member that places the medium PM1 separated in the medium separation device S11 and guides the medium PM1 to the image forming device S2. The transport belt 2031 is stretched by a driving roller 2032 and a stretching roller 2037 so as to surround the transport table 2033, and is rotated by the driving roller 2032 to transport the medium PM1 from the medium separating device S11 to the image forming device S2. Belt member. The driving roller 2032 receives the driving force of the driving motor S1M driven under the control of the control unit SS1, and is driven to rotate in the direction of arrow R32 (FIG. 2). The transport belt 2031 is configured to circulate and rotate in a direction indicated by an arrow R31 (FIG. 2) by the rotation of the drive roller 2032. The stretching roller 2037 is driven to rotate by the frictional force with the transport belt 2031. Further, the plurality of transport rollers 2034 are, for example, rotating bodies that rotate about axes extending in the Z-axis direction, and in the transport direction (X-axis direction) of the medium PM1 so as to face the transport belt 2031 and the transport table 2033. A plurality is provided along. The plurality of transport rollers 2034 rotate following the circulation rotation of the transport belt 2031 while sandwiching the medium PM1 with the transport belt 2031 to transport the medium PM1 toward the image forming apparatus S2. ing. The medium sensor 2035 is provided near the leading end of the sheet feeding / conveying unit 2010 (near the stretching roller 2037), and the medium sensor 2036 is located at an intermediate position in the X-axis direction (between the driving roller 2032 and the stretching roller 2037). Is provided.

[1.3 Detailed Configuration of Image Forming Apparatus S2]
Next, the configuration of the image forming apparatus S2 will be described with reference to FIG. The image forming apparatus S2 corresponds to a specific example of the “image forming apparatus” of the present invention. For example, an image (for example, a color Image). The image forming apparatus S2 includes a medium supply unit 100, a conveyance unit 300, an image formation unit 400, a medium reception unit 600, an intermediate transfer unit 700, a fixing unit 500, a discharge unit 800, a reversing unit 900, and a control inside a housing K. A section SS2 and a drive motor S2M are provided. The control unit SS2 performs overall control of the image forming apparatus S2 in cooperation with the control unit SS1 in the medium supply device S1. The drive motor S2M functions as an entire drive source based on a command from the control unit SS2.

(Medium supply unit 100)
The medium supply unit 100 includes a paper feed tray 101, a mounting plate 102, a lift-up lever 103, a motor 104, a lift detection unit 201, a pickup roller 202, a feed roller 203, and a retard roller 604. .

  The paper feed tray 101 is, for example, removably attached to the lower part of the image forming apparatus S <b> 2, and stacks and accommodates the media PM <b> 2, and the mounting plate 102 is provided rotatably about the axis J <b> 102. . Part of the medium PM2 is stacked on the mounting plate 102. A lift-up lever 103, which is rotatably supported by a shaft J103, is provided on a feed-out side of the paper feed tray 101 where the medium PM2 is fed out. The shaft J103 rotates by the driving force from the motor 104. The motor 104 is driven or stopped, for example, by a signal from the control unit SS2. In such a medium supply unit 100, when the lift-up lever 103 rotates about the axis J103, the tip of the lift-up lever 103 pushes up the mounting plate 102, and the medium placed on the mounting plate 102 PM2 also rises. With such a configuration, a state where the upper surface of the uppermost medium PM2 is in contact with the pickup roller 202 is ensured. The elevation detection unit 201 detects that the mounting plate 102 is sufficiently pushed up to a predetermined height, and that the upper surface of the uppermost medium PM2 is in contact with the pickup roller 202. The control unit SS2 stops driving the motor 104 based on a signal from the elevation detection unit 201. The pickup roller 202, the feed roller 203, and the retard roller 204 function as a print medium feeding unit that supplies the medium PM2 stored in the paper feed tray 101 to the transport unit 300 one by one. The pickup roller 202 and the feed roller 203 are driven to rotate in the direction of the arrow shown in FIG.

(Medium receiving unit 600)
The medium receiving portion 600 is a portion that receives the medium PM1 conveyed from the medium conveying device S12 of the medium supply device S1, and is provided near an opening provided on a side surface of the housing K. The medium receiving section 600 includes, in order, a mounting section 601 in which the front end of the medium transport device S12 is detachably formed, a pickup roller 602, a feed roller 603, and a retard roller 204. The pickup roller 602, the feed roller 603, and the retard roller 604 function as a print medium feeding unit that supplies the medium PM1 conveyed from the medium conveyance device S12 to the conveyance unit 300 one by one.

  Note that the pickup rollers 202 and 602 and the feed rollers 203 and 603 each include, for example, a one-way clutch mechanism, and may be configured to be rotatable in the direction of the arrow. Further, the retard rollers 204 and 604 generate a rotation torque in the direction of the arrow shown in FIG. 1 by the rotation torque generation unit.

(Transport unit 300)
The transport unit 300 is a mechanism that transports the medium PM2 from the medium supply unit 100 or the medium PM1 from the medium transport device S12 one by one to the transfer unit. The transport unit 300 includes, for example, a media sensor 301, a transport roller pair 302, a media sensor 303, a transport roller pair 304, a media thickness sensor 320, a media sensor 330, and a transport roller pair 305 arranged in order from upstream to downstream. are doing. The transport roller pairs 302, 304, and 305 transport the media PM1 and PM2 downstream while regulating their skew. The medium PM1 from the medium receiving unit 600 joins the conveyance path between the conveyance roller pair 302 and the conveyance roller pair 304. The medium sensors 301, 303, and 330 detect the positions of the media PM1 and PM2 in order to adjust the drive timing of the transport roller pairs 302, 304, and 305.

(Image forming unit 400)
The image forming section 400 has, for example, image forming units 400Y, 400M, 400C, and 400K. The image forming units 400Y, 400M, 400C, and 400K respectively use the corresponding toners of the respective colors, that is, the yellow toner, the magenta toner, the cyan toner, and the black toner to form the toner images of the respective colors as specific examples of the developer image. To form.

  The image forming units 400Y, 400M, 400C, and 400K respectively include, for example, the photosensitive drum 401, the charging roller 402, the LED (Light Emitting Diode) head 850, the developing roller 404, the cleaning unit 405, and the toner storage units 406Y, 406M, and 406C. 406K and a supply roller 407. The charging roller 402, the developing roller 404, and the supply roller 407 constitute a developing unit, and operate under the control of the control unit SS2.

  The photoconductor drum 401 is a columnar member that carries an electrostatic latent image on the surface (surface layer portion) and extends in the Z-axis direction, and is configured using a photoconductor (for example, an organic photoconductor). Specifically, the photosensitive drum 401 has a conductive support and a photoconductive layer covering the outer periphery (surface). The conductive support is made of, for example, a metal pipe made of aluminum. The photoconductive layer has, for example, a structure in which a charge generation layer and a charge transport layer are sequentially stacked. Such a photosensitive drum 401 rotates at a predetermined peripheral speed (in this example, rotates counterclockwise as indicated by an arrow in FIG. 1) according to a command from the control unit SS2.

  The charging roller 402 is a member (charging member) that charges the surface (surface layer portion) of the photoconductor drum 401 and is arranged so as to be in contact with the surface (peripheral surface) of the photoconductor drum 401. The charging roller 402 has, for example, a metal shaft and a semiconductive rubber layer (for example, a semiconductive epichlorohydrin rubber layer) covering the outer periphery (surface). Note that, in this example, the charging roller 402 rotates clockwise (rotates in the opposite direction to the photosensitive drum 401).

  The developing roller 404 is a member that carries a toner for developing an electrostatic latent image on its surface, and is arranged so as to be in contact with the surface (peripheral surface) of the photosensitive drum 401. The developing roller 404 has, for example, a metal shaft and a semiconductive urethane rubber layer covering the outer periphery (surface). Such a developing roller 404 rotates at a predetermined peripheral speed (in this example, rotates clockwise, which is the opposite direction to the photosensitive drum 401).

  The toner storage units 406Y, 406M, 406C, and 406K store yellow toner, magenta toner, cyan toner, and black toner, respectively, and supply toner of each color to the supply roller 407 as appropriate.

  The supply roller 407 is a member (supply member) for supplying each color toner to the developing roller 404, and is arranged so as to be in contact with the surface (peripheral surface) of the developing roller 404. The supply roller 407 has, for example, a metal shaft and a foamable silicone rubber layer covering the outer periphery (surface) thereof. In this example, the supply roller 407 rotates clockwise (rotates in the same direction as the developing roller 404).

  Each of the LED heads 850 is an exposure device that forms an electrostatic latent image on the surface (surface layer) of the photosensitive drum 401 by exposing the surface of the photosensitive drum 401. Each of the LED heads 850 has a plurality of LED light emitting units arranged in the Z-axis direction with respect to one photosensitive drum 401. Each LED light emitting unit is configured to include a light source such as a light emitting diode that emits irradiation light, and a lens array that forms the irradiation light on the surface of the photosensitive drum 401.

  The cleaning unit 405 removes toner remaining on the surface of the photosensitive drum 401 after transferring the toner image to the media PM1 and PM2.

(Intermediate transfer unit 700)
The intermediate transfer unit 700 is also called an intermediate transfer belt unit, and includes an intermediate transfer belt 701, a driving roller 702, a driven roller 703, a backup roller 704, a plurality of primary transfer rollers 705, a cleaner 706, It has a secondary transfer roller 707 and an urging member 708. The driving roller 702, the driven roller 703, the backup roller 704, the plurality of primary transfer rollers 705, and the secondary transfer roller 707 each have a substantially columnar shape rotatable around a rotation shaft portion extending in the Z-axis direction perpendicular to the paper surface. It is a member. The intermediate transfer unit 700 transports the media PM1 and PM2 transported from the transport roller pair 305 along the transport direction, and transfers the toner images formed in the image forming units 400Y, 400M, 400C and 400K in the transport direction. Is a mechanism for sequentially transferring the image to the intermediate transfer belt 701 along the path.

  The intermediate transfer belt 701 is an endless elastic belt made of a resin material such as a polyimide resin. The intermediate transfer belt 701 is stretched (stretched) by a driving roller 702, a driven roller 703, and a backup roller 704.

  The drive roller 702 rotates clockwise in the direction of the arrow shown in FIG. 1 by the power transmitted from the drive motor S2M controlled by the control unit SS2, and circulates and rotates the intermediate transfer belt 701 in the rotation direction R701. Things. The drive roller 702 is disposed upstream of the image forming units 400Y, 400M, 400C, and 400K in the rotation direction R701 of the intermediate transfer belt 701. The driven roller 703 adjusts the tension applied to the intermediate transfer belt 701 by the urging force of the urging member 708. The driven roller 703 rotates in the same direction as the rotation direction R701, and is disposed downstream of the image forming units 400Y, 400M, 400C, and 400K in the rotation direction R701. The drive roller 702, the driven roller 703, and the biasing member 708 constitute a drive mechanism for driving the intermediate transfer belt 701. The cleaner 706 is a member for scraping and cleaning the toner adhered on the transfer surface of the intermediate transfer belt 701.

  The secondary transfer roller 707 forms a secondary transfer unit 750 together with the backup roller 704. The secondary transfer roller 707 and the backup roller 704 face each other and are arranged so as to sandwich the intermediate transfer belt 701. The secondary transfer roller 707 has, for example, a metal core material and an elastic layer such as a foamed rubber layer formed so as to be wound around the outer peripheral surface of the core material. One end of the secondary transfer roller 707 is urged toward the backup roller 704 by an urging member such as a coil spring fixed at one end to the housing K of the image forming apparatus S2. As a result, the secondary transfer roller 707 is pressed against the backup roller 704 via the intermediate transfer belt 701.

  When the backup roller 704 and the secondary transfer roller 707 transfer (secondary transfer) the toner image on the intermediate transfer belt 701 to the media PM1 and PM2 supplied from the transport roller pair 305, the secondary transfer roller 707 A DC voltage is applied to generate a potential difference between the secondary transfer roller 707 and the backup roller 704.

(Configuration of the fixing unit 500)
The fixing unit 500 applies heat and pressure to the toner images transferred onto the media PM1 and PM2 that have passed through the secondary transfer unit 750 including the backup roller 704 and the secondary transfer roller 707, so that the toner A member for fixing an image on the media PM1 and PM2. The fixing unit 500 includes an upper roller 501 and a lower roller 502 as shown in FIG.

  The upper roller 501 and the lower roller 502 each include heat sources 503A and 503B, which are heaters such as halogen lamps, inside thereof, and apply heat to the toner images on the media PM1 and PM2. Function as For example, the upper roller 501 is rotationally driven by a drive motor S2M controlled by the control unit SS2. The heat sources 503A and 503B are supplied with a bias voltage controlled by the control unit SS2, and control the surface temperatures of the upper roller 501 and the lower roller 502.

  The lower roller 502 is disposed opposite to the upper roller 501 so that a pressure contact portion is formed between the lower roller 502 and the upper roller 501, and is a pressure roller that applies pressure to the toner images on the media PM1 and PM2. Function as The lower roller 502 preferably has a surface layer made of an elastic material.

(Ejection unit 800)
The discharge unit 800 includes, for example, a pair of conveying rollers 801 to 804 and a stacker 805. Accordingly, the media PM1 and PM2 sent from the fixing unit 500 are sequentially transported by the transport roller pairs 801 to 804 as they are when the discharge separator 901 (described later) is in the posture shown in FIG. The sheet is discharged to the outside and stacked on the stacker 805.

(Reversal unit 900)
The reversing unit 900 forms a transport path for leading the image from the pair of transport rollers 305 to the secondary transfer unit 750 and the fixing unit 500 again to form an image on the front surface of the media PM1 and PM2 and then perform image formation on the back surface. Mechanism to form. The reversing unit 900 includes a discharge separator 901, a pair of reversing rollers 902, a reversing separator 903, a guide unit 904, pairs of conveying rollers 905 to 907, and a retreat unit 914.

  The media PM1 and PM2 discharged from the fixing unit 500 advance in the direction of arrow B by the rotation of the pair of reversing rollers 902 when the discharge separator 901 is switched to the switchback posture indicated by the broken line in FIG. , To the evacuation unit 914. Thereafter, when the reversing separator 903 rotates and the reversing roller pair 902 rotates in the reverse direction, the media PM1 and PM2 once stored in the retreating part 914 advance in the direction of arrow C. Further, the media PM1 and PM2 travel on the guide section 904 by the pair of transport rollers 905 to 907, are guided to the transport path before the pair of transport rollers 305, and are sent out to the secondary transfer section 750 again by the pair of transport rollers 305. With such a mechanism, printing can be performed on both sides of the media PM1 and PM2.

[1.4 Effects of Image Forming System]
(A. Basic operation)
In this image forming system, a toner image is transferred to the media PM1 and PM2 as described below.

  When print image data is input from an external device to the activated image forming apparatus S2, the control unit SS2 starts a print operation of the print image data.

  Specifically, the control unit SS2 drives the intermediate transfer belt 701 and the photosensitive drum 401 and causes the charging roller 402 to start a charging operation. Further, the control unit SS2 transmits an exposure control signal to each LED head 850. The LED head 850 irradiates the photosensitive drum 401 with light corresponding to a color component of a print image at a timing designated by the exposure control signal to form an electrostatic latent image on the surface of the photosensitive drum 401. The developing roller 404 applies a developer to each of the electrostatic latent images on the photosensitive drum 401 to form toners of yellow (Y), magenta (M), cyan (C), and black (K). Form an image. The primary transfer rollers 705Y, 705M, 705C, and 705K receive a transfer bias from a power supply circuit in the control unit SS2 and sequentially transfer the toner images on the respective photosensitive drums 401 to the transfer surface of the intermediate transfer belt 701. And overlap.

  Next, the control unit SS2 rotates the pickup rollers 202 and 602 and the feed rollers 203 and 603, and transmits a control signal to the control unit SS1 in the medium supply device S1 to start supplying the media PM1 and PM2. Thereby, the media PM1 and PM2 are supplied toward the transport unit 300 at a predetermined transport speed. As for the supply of the medium PM2, specifically, as shown in FIG. 1, first, the medium PM2 stored in the paper feed tray 101 is taken out one by one from the top by the pickup roller 202, It is sent out to. After the skew of the medium PM2 fed from the paper feed tray 101 is corrected by the feed roller 203 and the retard roller 204, the medium PM2 is transported to the secondary transfer unit 750 via the transport unit 300. The supply of the medium PM1 will be described later in detail.

  For example, when the positions of the media PM1 and PM2 are detected by the media sensor 330, a detection signal is transmitted to the control unit SS2. The control unit SS2 adjusts the transport speed of the media PM1 and PM2 and the rotation speed of the intermediate transfer belt 70, and aligns the media PM1 and PM2 with the toner image on the intermediate transfer belt 701. Accordingly, the toner image on the intermediate transfer belt 701 is secondarily transferred to a predetermined area on the media PM1 and PM2 at the secondary transfer position, that is, at a position where the backup roller 704 and the secondary transfer roller 707 face each other. Thereafter, in the fixing unit 500, heat and pressure are applied to the toner images transferred onto the media PM1 and PM2, and the toner images are fixed on the media PM1 and PM2. Finally, the media PM1 and PM2 on which the toner images are fixed are discharged to the outside by a pair of conveying rollers 801 to 804 in the discharge unit 800 and accumulated in the stacker 805.

(B. Operation of Medium Supply Apparatus S1)
Next, the operation of the medium supply device S1 will be described with reference to FIGS. A plurality of media PM1 such as envelopes are stacked on the stacker 2020. By stacking the plurality of media PM1 in a state where the rear ends of the plurality of media PM1 are lifted by the stack guide 2021, the weight of the plurality of media PM1 is dispersed. In addition, the plurality of media PM1 are set so that their front ends abut on the set guide 2022 so that they do not advance downstream. When the control unit SS1 receives a control signal from the control unit SS2 of the image forming apparatus S2 in this state, the control unit SS1 detects the medium PM1 on which the medium sensor 2012 provided below the stacker 2020 is loaded, and detects the medium sensor 2035 If at least one of the medium sensor 2036 and the medium sensor 2036 does not detect the medium PM1, the drive motor S1M is driven. Even when the medium sensor 2012 is detecting the medium PM1, the control unit SS1 does not drive the drive motor S1M when both the medium sensor 2035 and the medium sensor 2036 detect the medium PM1. In addition, as a matter of course, the control unit SS1 does not drive the drive motor S1M when the medium sensor 2012 does not detect the medium PM1.

  The drive of the drive motor S1M causes the drive roller 2013 to rotate in the direction of the arrow R13 (FIG. 2). The rotation of the drive roller 2013 causes the paper feed belt 2011 to circulate and rotate in the direction indicated by the arrow R11 (FIG. 2). Thereby, one medium PM1 located at the lowermost layer among the plurality of media PM1 stacked on the stacker 2020 is fed out in the + X direction. However, due to the frictional force between the media PM1, the media PM1 may be fed in the + X direction while being stacked. One or a plurality of the fed-out media PM1 enters a gap between the pre-separation guide 2026 and the paper feed belt 2011, and is further fed between the paper feed belt 2011 and the auxiliary roller 2009 (nip portion). . Due to the function of the pre-separation guide 2026, the number of the media PM1 entering between the paper feed belt 2011 and the auxiliary roller 2009 becomes about one or two. One or a plurality of media PM1 travels in the + X direction so as to pass through the separator 2003 while passing through the nip portion between the paper feed belt 2011 and the auxiliary roller 2009 and further contacting the contact surface 2003S of the separator 2003. When the plurality of media PM1 arrives at the separator 2003 while being superposed, the upper layer medium PM1 is locked by the separator 2003, and only the lowermost layer medium PM1 proceeds so as to pass under the separator 2003. Due to such behavior, in the separation unit 2001, only one medium PM1 is separated from the plurality of media PM1 and is fed to the downstream medium transport device S12.

  The drive of the drive motor S1M causes the drive roller 2032 to rotate in the direction of the arrow R32 (FIG. 2). By the rotation of the driving roller 2032, the transport belt 2031 circulates and rotates in the direction indicated by the arrow R31 (FIG. 2). As a result, one medium PM1 that has reached the medium transport device S12 after being separated in the medium separating device S11 is transported on the transport table 2033 in the + X direction by the frictional force generated between the medium PM1 and the transport belt 2031. When the front end of the medium PM1 is detected by the medium sensor 2035, the drive motor S1M stops. Therefore, the transport operation of the medium PM1 is stopped. At this time, the front end of the medium PM1 may be located downstream of the nip between the pickup roller 602 and the transport belt 2031. Thereafter, the pickup roller 602 rotates under the control of the control unit SS2 in the image forming apparatus S2, and when it is detected that the medium PM1 has been transported further downstream and the rear end of the medium PM1 has passed the medium sensor 2036, the drive is started. The operation of the motor S1M is restarted, and the medium supply operation of the new medium PM1 in the medium supply device S1 is started.

  As described above, during the medium separation operation, the auxiliary roller 2009 is kept urged by the paper feed belt 2011 via the medium PM1, while the height position of the separator 2003 (the position in the Y-axis direction) is maintained. ) Can be set arbitrarily. FIG. 2 shows a state in which the height position at the forefront of the contact surface 2003S of the separator 2003 is substantially the same as the height position of the surface 2011S of the sheet feeding belt 2011. On the other hand, FIGS. 4A and 4B show a state where the height position at the forefront of the contact surface 2003S is located lower than the height position of the surface 2011S of the sheet feeding belt 2011. The height position of the separator 2003 is adjusted in advance by operating the knob 2004 in accordance with the type (material and thickness) of the medium PM1. In general, the separation load increases as the overlap amount L shown in FIG. 4B increases. Here, the separation load refers to a force required when one medium PM1 is separated by the separator 2003 from the plurality of stacked media PM1. That is, unless the plurality of media PM1 stacked with a transport force exceeding the separation load is transported, the paper feed transport unit 2010 cannot separate one medium PM1 from the plurality of media PM1. The progress of all the reached media PM1 will be delayed. Therefore, in order to perform the medium separation operation, the separation load on the separator 2003 must be increased by the conveyance force of the sheet conveyance unit 2010.

  By the way, the conveying force of the sheet feeding / conveying unit 2010 is substantially determined by the rotation torque of the sheet feeding belt 2011 and the frictional force between the surface 2011S of the sheet feeding belt 2011 and the medium PM1. Here, the rotation torque of the paper feed belt 2011 is constant. However, the frictional force between the surface 2011S and the medium PM1 changes depending on the number (total weight) of the medium PM1 loaded on the stacker 2020. That is, the initial frictional force at the start of the printing operation in the image forming system indicates the maximum frictional force, and as a result, the transporting force by the paper feeding and transporting unit 2010 becomes maximum. Thereafter, as the printing operation is repeated, the frictional force decreases as the number of sheets of the medium PM1 stacked on the stacker 2020 decreases, and as a result, the conveying force of the sheet feeder 2010 also decreases. On the other hand, although the separation load in the separator 2003 varies depending on the overlap amount L, it does not have a characteristic that varies depending on the number of the media PM1 (when the auxiliary roller 2009 does not exist). FIG. 5A is a characteristic diagram schematically showing a relationship between a conveying force and a separation load in a medium separation device having a general structure in which the auxiliary roller 2009 does not exist, and a total weight of the medium loaded on the stacker. . In FIG. 5A, the horizontal axis represents the total weight of the media loaded on the stacker, and the vertical axis represents the conveying force and the separation load. In FIG. 5A, a straight line C51 represents the separation load, and a straight line C52 represents the conveying force. As shown in FIG. 5A, the separation load is constant irrespective of the total weight of the medium, while the conveying force tends to be proportional to the total weight of the medium. Therefore, even if the relationship of (conveyance force)> (separation load) is obtained at the beginning of the printing operation, when the remaining amount of the medium in the stacker becomes small, the above relationship is reversed and (conveyance force) <( (Separation load). In that case, the progress of the medium is delayed (medium non-feed). Therefore, for example, as shown by a straight line 51A in FIG. 5A, by lowering the separation load, the relationship of (transport force)> (separation load) is maintained even when the remaining amount of the medium is reduced. It is also conceivable to do this. However, in this case, at the beginning of the printing operation, the conveyance force becomes too large compared to the separation load (the relation of (conveyance force) >> (separation load)), and depending on the type of the medium, curling or wrinkling occurs. Or, there is a possibility that double feed (a phenomenon in which a plurality of media are conveyed while overlapping) may occur, which is not preferable. Further, a method of changing the overlap amount L continuously or stepwise according to the remaining amount of the medium in the stacker can be considered. However, since the appropriate overlap amount L differs depending on the type of the medium, etc. A complicated control mechanism is required.

  Therefore, in the present embodiment, the auxiliary roller 2009 is provided on the separator frame 2006 supporting the separator 2003, and the auxiliary roller 2009 is elastically displaced with respect to the separator 2003 along the Y-axis direction. Thereby, as shown in FIG. 5B, for example, the auxiliary roller 2009 is displaced in the Y-axis direction in conjunction with the separator 2003, and responds to a change in the separation load due to a change in the height position (overlap amount L) of the separator 2003. The added auxiliary conveyance force can be applied to the medium PM1. In FIG. 5B, the horizontal axis represents the amount of overlap L, and the vertical axis represents the conveying force and the separation load. In FIG. 5B, a straight line C53 represents the separation load, and a straight line C54 represents the conveying force. As shown in FIG. 5B, in the present embodiment, the transfer force can be increased or decreased in accordance with the increase or decrease of the overlap amount L, so that the separation load and the transfer force can be linked. Therefore, an appropriate relationship between the separation load and the conveyance force can be obtained without performing complicated control regardless of the remaining amount of the medium PM1. As a result, non-feeding of the medium PM1, damage to the medium PM1 (generation of curls and wrinkles), or double feeding is avoided.

(C. Effects of Image Forming System)
As described above, in the present embodiment, in the medium supply device S1, the auxiliary roller 2009 that sandwiches the medium PM1 with the paper feed belt 2011 is elastically displaced along the Y-axis direction with respect to the separator 2003. Are held in the separator frame 2006. For this reason, the auxiliary conveyance force according to the change of the separation load can be applied to the medium PM1. Therefore, excellent medium separation performance can be exhibited without performing complicated control.

<2. Second Embodiment>
[2.1 Overall Configuration of Separation Unit 10A]
Next, a separation unit 10A according to a second embodiment of the present invention will be described with reference to FIGS. The separation unit 10A is mounted on the image forming system described in the first embodiment, for example, and performs a medium separation operation in the medium separation device S11. FIG. 6 is a perspective view illustrating an overall configuration example of the separation unit 10A. 7A is a side view of the separation unit 10A as viewed from the downstream side, and FIG. 7B is an enlarged view of a main part of the separation unit 10A shown in FIG. 7A. The separation unit 10A has a separation unit 2001A and a sheet feeding / conveying unit 2010. The sheet feeding / conveying unit 2010 is the same as that described in the first embodiment. Therefore, in the present embodiment, separation section 2001A will be mainly described.

(Configuration of Separation Unit 2001A)
FIG. 8A is a perspective view illustrating the appearance of the separation unit 2001A, and FIG. 8B is a perspective view illustrating the internal structure of the separation unit 2001A. The separation unit 2001A has a separation piece 1, a frame 2, a cover 3, a lever 4, and release levers 5A and 5B. The separation piece 1 is provided so as to face the sheet feeding / conveying unit 2010, and has a contact surface 1S (FIG. 7B) that comes into contact with the medium PM1 during the medium separation operation in the medium separation device S11. ing. The separation piece 1 is a specific example corresponding to the “contact member” of the present invention, and is located at the center of the sheet feeding / conveying unit 2010 in the Z-axis direction, that is, between the adjacent sheet feeding belts 2011C and 2011D. It is located in. Accordingly, even when the separation piece 1 is moved in the Y-axis direction, the contact surface 1S of the separation piece 1 does not interfere with the sheet feeding belt 2011. Therefore, as shown in FIGS. 10A, 10B, and 11 described later, the separation piece 1 can move in the −Y direction to a position overlapping (overlapping) with the paper feed belt 2011 in the Z-axis direction. It has become. Here, as shown in FIG. 7B, a gap between the contact surface 1S of the separation piece 1 and the surface 2011S of the sheet feeding belt 2011 is defined as a gap YG.

  9A shows a cross section of the separation unit 2001A parallel to the XY plane, and FIG. 9B is a perspective view showing the internal structure of the separation unit 2001A, showing a state in which some components have been removed. Further, FIG. 9C is a perspective view illustrating other components inside the separation unit 2001A. As shown in FIGS. 8A to 9C, the separation portion 2001A includes lock posts 6A and 6B, ratchet plates 7A and 7B, a shaft 8, a movable post 9, a coil spring 11, a frame 12, and a post 13. And further.

  The frame 2 is a base to which various members are attached. For example, as shown in FIG. 8B, two ratchet plates 7A and 7B including a substantially arc-shaped outer edge are fixed. The ratchet plate 7A and the ratchet plate 7B each extend in, for example, the XY plane, and are fixed to the frame 2 so as to be adjacent to each other in the Z-axis direction. A plurality of recesses 7UA, 7UB are formed on the outer edges of the ratchet plates 7A, 7B, which form a substantially circular arc, so as to be arranged in the circumferential direction. In the example shown in FIG. 8B, the shape and size of the ratchet plate 7A and the shape and size of the ratchet plate 7B are the same, and the concave portions 7UA and 7UB are formed in the same phase. The lock posts 6A, 6B engage with the recesses 7UA, 7UB, respectively. The lock posts 6A, 6B are provided at one ends of the release levers 5A, 5B so as to protrude in the -Z direction or the + Z direction, respectively. Notches 7K extending in the Y-axis direction are formed in the ratchet plates 7A and 7B, respectively, so that the movable post 9 extending in the Z-axis direction is guided in the Y-axis direction. Further, the separation unit 2001A has a ratchet plate post 7P extending in the Z-axis direction so as to connect the ratchet plate 7A and the ratchet plate 7B. The lock posts 6A, 6B and the ratchet plates 7A, 7B correspond to one specific example of the "locking portion" of the present invention.

  A lever 4 is held on the frame 2 so as to be rotatable around a shaft 8 extending in, for example, the Z-axis direction. The shaft 8 is fixed to the side walls 2A and 2B of the frame 2 (FIGS. 8A and 8B). The lever 4 extends in a direction away from the shaft 8 and has a base 4A formed with an elongated hole 4H whose longitudinal direction is the extending direction, and a cam portion formed at one end of the base 4A and supported by the shaft 8. 4B, and an operation unit 4C provided at the other end of the base 4A. The cam portion 4B is a plate-like portion extending in the XY plane, and has a cam surface 4K on the outer edge thereof (FIG. 9B). The cam portion 4B is a specific example corresponding to the “first cam” of the present invention. The cam portion 4B rotates about the Z axis while maintaining a state where the cam surface 4K is in contact with the surface of the movable post 9 as described later. A connecting member 5P that connects the release lever 5A and the release lever 5B is inserted into the elongated hole 4H, and the connecting member 5P is guided along the longitudinal direction of the elongated hole 4H. Thereby, the release levers 5A, 5B and the lock posts 6A, 6B can be displaced with respect to the lever 4 along the extending direction of the base 4A. The release levers 5A and 5B and the lock posts 6A and 6B are urged to approach the shaft 8 by the urging force of a coil spring 22 that connects a part of the release lever 5A and a part of the lever 4, for example. (See FIGS. 9B and 9C). The lever 4 can reversibly rotate around the shaft 8 in, for example, the range of the arrow 4R (between the position P1 and the position P2) shown in FIG. 9A. However, when rotating the lever 4, the release levers 5A and 5B are displaced in the direction of arrow Y5 with respect to the lever 4, that is, in the direction away from the shaft 8, and the lock posts 6A and 6B are depressed in the recesses 7UA in the ratchet plates 7A and 7B. , 7UB.

  In the separation unit 2001A, a frame 12 holding the separation piece 1 is held by a frame 2 via a coil spring 11 so as to be elastically displaceable. The frame 12 includes a pair of side walls 12A and 12B facing each other across the separation piece 1 in the Z-axis direction. The movable post 9 and the post 13 are provided so as to extend in the Z-axis direction and connect the pair of side walls 12A and 12B. The separating piece 1 is fixed to the side walls 12A and 12B by mounting posts 20 and 21 penetrating therethrough. The post 13 is elastically connected to the ratchet plate post 7P by the coil spring 11. That is, the post 13 is urged by the urging force of the coil spring 11 so as to approach the ratchet plate post 7P. As a result, the movable post 9 is always kept in contact with the cam surface 4K provided on the outer edge of the cam portion 4B. On the side surface of the frame 2, a long hole 2H is formed at a position corresponding to the movable post 9, and a notch 2K is formed at a position corresponding to the post 13. Each of the elongated hole 2H and the notch 2K extends in the Y-axis direction, thereby guiding the movable post 9 and the post 13 in the Y-axis direction. Therefore, the separation piece 1 fixed to the frame 12 can reversibly move (vertically move) with respect to the frame 2 along the Y-axis direction.

(Operation of Separation Unit 2001A)
In the separation unit 2001A having the above configuration, the rotation of the lever 4 about the shaft 8 causes the separation piece 1 fixed to the frame 12 to move up and down along the Y-axis direction. This is because the rotation of the cam portion 4B changes the distance between the shaft 8 and the movable post 9 according to the shape of the cam surface 4K of the cam portion 4B (that is, the movable post 9 moves up and down with respect to the frame 2). . Therefore, by operating the lever 4, the adjustment of the gap YG (FIG. 7B) between the contact surface 1S of the separation piece 1 and the surface 2011S of the paper feed belt 2011 can be easily performed.

  10A and 10B are a perspective view and a side view showing a state where the height position of the separation piece 1 is displaced downward. FIGS. 10A and 10B show a state where the lever 4 is largely rotated from the position P1 (FIG. 9A) to the position P2 (FIG. 9A). The position P1 corresponds to an initial state (YG> 0) where the gap YG is relatively large as shown in FIG. On the other hand, the position P2 corresponds to the overlap state (YG <0) where the gap YG is relatively small as shown in FIG. The reason why the gap YG changes is that at the position P1, the movable post 9 is in contact with the portion 4K1 of the cam surface 4K which is relatively close to the center of the shaft 8, whereas at the position P2, the movable post 9 is in contact. 9 is in contact with a portion 4K2 of the cam surface 4K that is relatively far from the center of the shaft 8 (see FIG. 9A). In addition, in the present embodiment, the ratchet plates 7A, 7B are provided with a plurality of recesses 7UA, 7UB arranged along their outer edges, so that the lock posts 6A, 6B are engaged with them so that the lever 4 Can be locked stepwise at different positions (desired positions). Therefore, as shown in FIG. 12, an appropriate gap YG can be selected according to the ratchet position, that is, the position of the concave portions 7UA and 7UB with which the lock posts 6A and 6B are engaged. An appropriate gap YG is, for example, about -2 mm.

[2.2 Action and Effect]
In the separation unit 10A of the present embodiment, a cam portion that moves the separation piece 1 along the Y-axis direction so as to approach the paper feed belt 2011 or move away from the paper feed belt 2011 by displacement of its own posture. The lever 4 including the lever 4B, the lock posts 6A and 6B for locking the cam portion 4B in two or more positions, and the ratchet plates 7A and 7B are provided. Accordingly, the separation piece 1 is locked at an arbitrary position in the Y-axis direction, so that the gap YG can be easily adjusted in multiple stages. As a result, an appropriate separation load can be easily obtained, and non-feeding of the medium PM1 and damage to the medium PM1 (generation of curling or wrinkling) can be avoided. Therefore, according to the medium separation device S11, the medium supply device S1, and the image forming system including the separation unit 10A, excellent medium separation performance can be exhibited.

[2.3 First Modification Example of Separation Unit 2001A]
In the separation unit 2001A shown in the second embodiment, the shape and size of the ratchet plate 7A and the shape and size of the ratchet plate 7B are the same, and the concave portions 7UA and 7UB are formed in the same phase. . However, for example, as in the separation unit 2001A1 shown in FIG. 13, the arrangement position of the concave portion 7UA on the ratchet plate 7A and the arrangement position of the concave portion 7UB on the ratchet plate 7B may be shifted in phase. In this case, the lever 4 can be locked at both the position where only the lock post 6A engages with the concave portion 7UA and the position where only the lock post 6B engages with the concave portion 7UB. Multi-stage adjustment of YG can be performed.

[2.4 Second Modification Example of Separation Unit 2001A]
14A and 14B are a perspective view and a cross-sectional view illustrating an internal structure of a separation unit 2001A2 as a second modification of the separation unit 2001A. The separating portion 2001A2 has a cam 14 at a position of the movable post 9 which comes into contact with the cam surface 4K of the cam portion 4B. At the end of the movable post 9 opposite to the end where the cam 14 is provided, a cam adjusting portion 15 for adjusting the posture of the cam 14 is provided. The cam 14 is a specific example corresponding to the “second cam” of the present invention. Similarly to the cam portion 4B, the cam 14 moves the separation piece 1 along the Y-axis direction so as to approach the paper feeder 2010 or move away from the paper feeder 2010 by the displacement of its own posture. It works to make it work. For example, the state of FIGS. 14A and 14B is a state in which the separation piece 1 is displaced most upward. On the other hand, as shown in FIG. 15A, for example, when the lever 4 is depressed, the posture of the cam portion 4B changes, and the cam 14 (movable post 9) abutting on the cam surface 4K is largely displaced downward. In this state, the posture of the cam 14 is changed by rotating the cam adjusting unit 15. FIG. 15B shows that the cam surface 4K of the lever 4 is in contact with the cam surface 14K of the cam 14 at a position relatively far from the rotation center of the movable post 9. For this reason, in FIG. 15B, the separation piece 1 is slightly displaced further downward than in the state of FIG. 15A. By providing the cam 14 in this manner, the gap YG can be finely adjusted steplessly.

  FIG. 16 shows the relationship between the ratchet position and the gap YG in the separation unit 2001A2. In FIG. 16, a curve C4 indicates a change in the gap YG according to the ratchet position when only the adjustment by the lever 4 (change in the posture of the cam portion 4B) is performed. On the other hand, curves C14A and C14B show changes in the gap YG according to the ratchet position when fine adjustment is performed by changing the attitude of the cam 14 in addition to the lever 4. However, a curve C14A shows a case where the separation piece 1 is displaced in the + Y direction by adjusting the posture of the cam 14, and a curve C14B shows a case where the separation piece 1 is displaced in the −Y direction by adjusting the posture of the cam 14. .

<3. Other Modifications>
As described above, the present invention has been described with reference to the embodiments and the modifications, but the present invention is not limited to the above-described embodiments and the like, and various modifications are possible. For example, in the above embodiments and the like, an image forming apparatus that forms a color image has been described. However, the present invention is not limited to this. For example, an image forming apparatus that transfers only a black toner image to form a monochrome image It may be. Further, in the above-described embodiment and the like, the image forming apparatus of the secondary transfer system has been described, but the present invention can also be applied to a primary transfer system (direct transfer system).

  Further, in the above-described embodiment and the like, six paper feed belts 2011 are illustrated, but the number is not limited in the present invention. Further, a coil spring has been exemplified as the elastic body, but another member such as a leaf spring may be used. In the second embodiment, two ratchet plates are provided. However, the number is not limited to two. For example, only one plate may be provided, or three or more plates may be arranged. Good. Further, the shape of the cam surface 4K in the cam portion 4B of the lever 4 can be appropriately changed.

  Further, in the above embodiments and the like, an LED head using a light emitting diode as a light source is used as an exposure device. However, an exposure device using a laser element or the like as a light source may be used.

  Further, in the above embodiments and the like, the image forming apparatus having the printing function has been described as a specific example of the “image forming apparatus” in the present invention, but the present invention is not limited to this. That is, the present invention can be applied to an image forming apparatus that functions as a multifunction peripheral having a scan function and a fax function in addition to the print function.

  DESCRIPTION OF SYMBOLS 1 ... Separation piece, 2 ... Frame, 3 ... Cover, 4 ... Lever, 5 ... Release lever, 6A, 6B ... Lock post, 7A, 7B ... Ratchet plate, 8 ... Shaft, 9 ... Movable post, 11, 22 ... Coil Spring, 12 ... frame, 13 ... post, 14 ... cam, 15 ... cam adjustment unit, 10, 10A ... separation unit, 2001, 2001A ... separation unit, 2002 ... separation frame, 2003 ... separator, 2004 ... knob, 2005 ... bridge , 2006: separator frame, 2007: guide shaft, 2008: elastic body, 2009: auxiliary roller, 2010: paper feeder, 2011: paper feed belt, 2012: medium sensor, 2013: drive roller, 2014: tension roller, 2020: Stacker, 2021: Stack guide, 2022: Set guide, 2023: Roller frame, 20 4 Connection part, 2025 Support part, 2026 Pre-separation guide, 2027 Loading guide, 2031 Transport belt, 2032 Drive roller, 2033 Transport table, 2034 Transport roller, 2037 Stretch roller, 100 Medium Supply unit, 101: paper feed tray, 202: pickup roller, 203: feed roller, 204: retard roller, 300: transport unit, 400: image forming unit, 500: fixing unit, 501: upper roller, 502: lower roller, 503A, 503B heat source, 600 medium receiving unit, 700 intermediate transfer unit, 701 intermediate transfer belt, 702 drive roller, 703 driven roller, 704 backup roller, 707 secondary transfer roller, 750 secondary Transfer unit, 800: discharge unit, 801 to 804: transport roller pair, 805: stacker, 9 0 ... reversing unit, K ... housing, PM1, PM2 ... medium, S1 ... medium supplying device, S11 ... medium separation device, S12 ... medium transport device, S2 ... image forming apparatus.

Claims (10)

A stacker for stacking and holding a plurality of media;
A separation unit that separates the plurality of media one by one,
The separation unit,
A moving body that conveys the medium in the first direction by moving in a first direction;
An urging member that contacts the moving body via the medium in a second direction and applies an urging force to the medium to urge the medium toward the moving body;
A movable member is provided along the second direction so as to approach or move away from the moving body, and is configured to contact the medium passing between the moving body and the urging member. And a contact member including a contact surface,
The medium separating device, wherein the urging force of the urging member fluctuates according to the position of the contact member with respect to the position of the moving body in the second direction. A base for holding the contact member movably along the second direction;
Anda drive motion roller,
The medium separation device according to claim 1, wherein the moving body is an endless belt rotated by the driving roller. The medium separation device according to claim 1, wherein the urging member includes a rotating body that rotates with the movement of the moving body. The medium separation device according to any one of claims 1 to 3, wherein the urging member is located between the contact member and the stacker in the first direction. The medium separation device according to claim 4, further comprising: a guide portion that is located between the urging member and the stacker in the first direction and guides the medium. The medium separation device according to claim 1, wherein the urging member includes an elastic body that elastically deforms in the second direction. The moving body includes a first portion and a second portion that are adjacent to each other in a third direction substantially orthogonal to the first direction and transport the medium in the first direction, respectively.
The medium separation device according to any one of claims 1 to 6, wherein the contact member is located between the first portion and the second portion in the third direction. The medium separation device according to claim 7, wherein the contact member is movably provided at a position overlapping with the first portion and the second portion in the third direction. A stacker that stacks and holds a plurality of media, and a media separation device that has a separation unit that separates the plurality of media one by one,
A medium transport device that transports the medium separated in the medium separation device,
The separation unit,
A moving body that conveys the medium in the first direction by moving in a first direction;
An urging member that contacts the moving body via the medium in a second direction and applies an urging force to the medium to urge the medium toward the moving body;
A movable member is provided along the second direction so as to approach or move away from the moving body, and is configured to contact the medium passing between the moving body and the urging member. And a contact member including a contact surface,
The medium supply device, wherein the urging force of the urging member fluctuates according to the position of the contact member with respect to the position of the moving body in the second direction. A medium supply device, and an image forming device,
The medium supply device,
A stacker that stacks and holds a plurality of media, and a media separation device that has a separation unit that separates the plurality of media one by one,
A medium transport device that transports the medium separated in the medium separation device,
The separation unit,
A moving body that conveys the medium in the first direction by moving in a first direction;
An urging member that contacts the moving body via the medium in a second direction and applies an urging force to the medium to urge the medium toward the moving body;
A movable member is provided along the second direction so as to approach or move away from the moving body, and is configured to contact the medium passing between the moving body and the urging member. And a contact member including a contact surface,
An image forming system, wherein an urging force of the urging member changes in accordance with a position of the contact member with respect to a position of the moving body in the second direction.

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