JP2019109283A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that can improve jam processability with a simple configuration.SOLUTION: An image forming apparatus 100 comprises: an image forming unit 30 that has a photoreceptor drum 5; a conveyance roller pair 40 that are provided in the body of the image forming apparatus 100, and nip and convey a sheet; and a pressure changing mechanism 60 that operates in conjunction with attachment/detachment of the image forming unit 30 to/from the body of the image forming apparatus 100, and changes a nip pressure at a nip part N of the conveyance roller pair 40. While the image forming unit 30 is attached to the body of the image forming apparatus 100, the pressure changing mechanism 60 sets the nip pressure at the nip part N to a first pressure, and while the image forming unit 30 is removed from the body of the image forming apparatus 100, sets the nip pressure at the nip part N to a second pressure smaller than the first pressure.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus provided with an imaging unit and a conveyance roller pair.

  2. Description of the Related Art Conventionally, there has been known an image forming apparatus which conveys a sheet (recording medium) along a sheet conveyance path, and transfers and fixes an image on the sheet being conveyed. In such an image forming apparatus, when a jam (paper jam) occurs in the sheet conveyance path, the cover of the apparatus main body is opened to perform jam processing, or the image forming unit or the like is removed from the apparatus main body to perform jam processing. There is a need to.

  Also, conventionally, in order to improve the jam processing performance, a clutch or the like is provided in the drive train from the motor to the transport roller pair, and the rotational load of the transport roller pair is reduced by disconnecting the drive train at the time of jam processing. Forming devices are known. There is also known an image forming apparatus which reduces the nip pressure of a conveying roller pair by using a drive motor at the time of jam processing.

  An image forming apparatus that uses a drive motor to release the nip pressure of the conveyance roller pair at the time of jam processing is disclosed in, for example, Patent Document 1.

Unexamined-Japanese-Patent No. 2004-101830

  However, in the conventional image forming apparatus in which the connection of the drive train is disconnected at the time of jam processing, or the nip pressure of the transport roller pair is reduced using the drive motor, the structure and control of the image forming apparatus become complicated. There is a problem.

  The present invention has been made to solve the problems as described above, and it is an object of the present invention to provide an image forming apparatus capable of improving the jam processing property with a simple structure.

  In order to achieve the above object, an image forming apparatus according to one aspect of the present invention is an image forming unit including an apparatus main body and an image carrier which is detachable from the apparatus main body and on which an electrostatic latent image is formed. A conveyance roller pair provided on the apparatus main body and configured to nip and convey the recording medium, and a release roller pair that operates in conjunction with attachment / detachment of the imaging unit to the apparatus main body; And a pressure change mechanism that changes the nip pressure of The pressure change mechanism uses the nip pressure of the nip portion as the first pressure in the mounted state where the imaging unit is mounted on the apparatus body, and the nip pressure of the nip portion in the detached state where the imaging unit is removed from the apparatus body. The second pressure is smaller than the first pressure.

  According to the image forming apparatus of one aspect of the present invention, the image forming apparatus includes a pressure changing mechanism that operates in conjunction with attachment / detachment of the image forming unit to / from the apparatus main body. At (1), the nip pressure at the nip portion is taken as a first pressure, and the nip pressure at the nip portion is taken as a second pressure smaller than the first pressure in the removal state in which the imaging unit is removed from the apparatus body. As a result, the nip pressure of the nip portion can be reduced from the first pressure to the second pressure in conjunction with the attachment / detachment of the image forming unit at the time of jam treatment, so that the jam treatment property can be improved.

  Further, since it is not necessary to separately provide a drive source such as a motor in order to reduce the nip pressure of the nip portion, it is possible to suppress the structure and control from being complicated.

  As described above, the jam clearance can be improved with a simple configuration.

FIG. 1 is a side cross-sectional view showing an internal structure of an image forming apparatus according to an embodiment of the present invention. FIG. 5 is a side view showing the structure of the periphery of a transport roller pair and the imaging unit of the image forming apparatus according to an embodiment of the present invention, showing a state (removal state) before the imaging unit is mounted on the image forming apparatus main body. It is. FIG. 5 is a side view showing the structure of the periphery of a transport roller pair and the image forming unit of the image forming apparatus according to an embodiment of the present invention, and showing a state in which the image forming unit is being mounted on the image forming apparatus main body. FIG. 6 is a side view showing the structure of the periphery of a conveyance roller pair and the image forming unit of the image forming apparatus according to an embodiment of the present invention, and a state in which the image forming unit is attached to the image forming apparatus main body (mounted state). FIG. 2 is a side cross-sectional view showing the structure around the lock mechanism of the image forming apparatus according to the embodiment of the present invention. FIG. 5 is a side view showing a structure around a conveyance roller pair of the image forming apparatus according to an embodiment of the present invention, and is a view showing a state where the imaging unit is not attached to the image forming apparatus main body (removal state). FIG. 5 is a side view showing the structure of the periphery of the transport roller pair of the image forming apparatus according to the embodiment of the present invention, and a view showing a state (mounted state) where the imaging unit is mounted on the image forming apparatus main body. FIG. 2 is a cross-sectional view showing a structure around a pressure change mechanism of an image forming apparatus according to an embodiment of the present invention. FIG. 6 is a perspective view showing the structure of a conveyance guide member and a pressing force change member of the image forming apparatus according to the embodiment of the present invention. FIG. 6 is a perspective view showing the structure of the conveyance guide member and the first roller of the image forming apparatus of the embodiment of the present invention from below. FIG. 3 is a perspective view showing a structure of a conveyance guide member of the image forming apparatus of the embodiment of the present invention. FIG. 3 is an exploded perspective view showing the structures of a conveyance guide member, a first roller, and a pressure change mechanism of the image forming apparatus according to an embodiment of the present invention from below. FIG. 10 is a side view showing the structure around the pressing force changing member and the pressing unit of the image forming apparatus of the modified example of the present invention, and showing a state in which the image forming unit is mounted on the image forming apparatus main body (mounted state).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side sectional view showing an internal structure of an image forming apparatus 100 according to an embodiment of the present invention. In the image forming apparatus (here, a monochrome printer) 100, an image forming portion P for forming a monochrome image by the steps of charging, exposure, development and transfer is disposed. In the image forming portion P, the charging device 4, the exposure unit (laser scanning unit etc.) 7, the developing device 8, and the like along the rotational direction (counterclockwise direction in FIG. 1) of the photosensitive drum (image carrier) 5. The transfer roller 14, the cleaning device 19, and the charge removing device 6 are disposed.

  When the image forming operation is performed, the photosensitive drum 5 rotating in the counterclockwise direction is uniformly charged by the charging device 4 and electrostatically charged on the photosensitive drum 5 by the laser beam from the exposure unit 7 based on the document image data. A latent image is formed, and a developer (hereinafter referred to as toner) is attached to the electrostatic latent image by the developing device 8 to form a toner image.

  The supply of toner to the developing device 8 is performed from the toner container 9. The image data is transmitted from a personal computer (not shown) or the like. Further, the charge removing device 6 is provided on the downstream side of the cleaning device 19 with respect to the rotational direction of the photosensitive drum 5, and removes the residual charge on the surface of the photosensitive drum 5.

  The photosensitive drum 5, the developing device 8 and the toner container 9 are unitized, and this unit is hereinafter referred to as an imaging unit 30. The image forming unit 30 is removable from the main body of the image forming apparatus 100.

  A sheet feeding cassette 10 is detachably provided at a lower portion of the image forming apparatus 100 main body, and a manual feed tray 11 is provided on one side 100 a of the image forming apparatus 100 main body so as to be openable and closable. A paper feed roller (feed roller) 25 for feeding (feed) a sheet (recording medium) on the manual feed tray 11 is provided on the downstream side (right side in FIG. 1) of the manual feed tray 11 in the paper feed direction. A transport roller pair 40 including a first roller 41 and a second roller 42 is provided immediately downstream of the feed roller 25 in the sheet feeding direction (feeding direction). A sheet feeding device 26 for feeding the sheet of the sheet feeding cassette 10 is provided on the downstream side (left side in FIG. 1) of the sheet feeding direction of the sheet feeding cassette 10. The pressure roller 27 is provided to be in pressure contact with the second roller 42.

  The sheet of the manual feed tray 11 is conveyed to the photosensitive drum 5 via the sheet conveyance path (recording medium conveyance path) 12 by the sheet feed roller 25, the conveyance roller pair 40 and the registration roller pair 13. The sheet of the sheet feeding cassette 10 is conveyed to the photosensitive drum 5 through the sheet conveyance path 12 by the sheet feeding device 26, the second roller 42 and the pressure roller 27, the conveyance roller pair 40, and the registration roller pair 13. Be done. The toner image formed on the surface of the photosensitive drum 5 is transferred by the transfer roller 14 onto the sheet conveyed to the photosensitive drum 5. The sheet on which the toner image has been transferred is separated from the photosensitive drum 5 and conveyed to the fixing device 15 to fix the toner image. The sheet having passed through the fixing device 15 is conveyed to the upper portion of the apparatus by the sheet conveyance path 16, and is discharged to the discharge tray 18 by the discharge roller pair 17 when forming an image on only one side of the sheet (in single-sided printing).

  On the other hand, when forming an image on both sides of the sheet (during double-sided printing), the sheet conveyance direction is reversed after the rear end of the sheet passes through the branch portion 20 of the sheet conveyance path 16. As a result, the sheet is distributed to the reverse conveyance path 21 branched from the branch unit 20, and is re-conveyed to the registration roller pair 13 in a state where the image surface is reversed. Then, the next toner image formed on the photosensitive drum 5 is transferred by the transfer roller 14 to the surface of the sheet on which the image is not formed. The sheet on which the toner image has been transferred is conveyed to the fixing device 15 and the toner image is fixed, and then the sheet is discharged to the discharge tray 18 by the discharge roller pair 17.

  An open / close cover 18 a constituting a part of the discharge tray 18 is provided on the upper surface of the image forming apparatus 100. Further, a lock mechanism 50 for holding the imaging unit 30 at a predetermined position in the main body of the image forming apparatus 100 is provided adjacent to the upstream side of the imaging unit 30 in the insertion direction. The detailed configuration of the lock mechanism 50 will be described later.

  The image forming unit 30 integrally holds the photosensitive drum 5, the developing device 8 and the toner container 9 by a unit housing 30a (see FIG. 2). 2 and the following drawings, the developing device 8 and the toner container 9 are omitted, and the image forming unit 30 is drawn by the unit housing 30 a and the photosensitive drum 5 in order to simplify the drawing.

  As shown in FIGS. 2 to 4, the imaging unit 30 is configured to be removable from one side 100 a (see FIG. 1) of the main body of the image forming apparatus 100. When the imaging unit 30 is attached to and detached from the main body of the image forming apparatus 100, the imaging unit 30 is attached and detached through the opening formed in the one side surface 100a by opening the manual feed tray 11. When the imaging unit 30 is attached to the main body of the image forming apparatus 100, the imaging unit 30 is inserted obliquely downward, and the rotation shaft 5a of the photosensitive drum 5 is positioned on the bearing member 29. Then, the imaging unit 30 is rotated by a predetermined angle in the counterclockwise direction of FIG. 3 about the rotation axis 5 a of the photosensitive drum 5 so that the imaging unit 30 is configured as the image forming apparatus 100 as shown in FIG. It is attached to the body.

  FIG. 5 is a side sectional view showing the structure around the lock mechanism 50. As shown in FIG. A lock member 53 engaged with an engagement protrusion 51 which projects rearward (left direction in FIG. 5) of the unit housing 30 a engages with the main body of the image forming apparatus 100, and the lock member 53 is coiled by a coil spring 55. It is biased in the protruding direction. A first inclined surface 51 a is formed on the lower surface corner of the engagement protrusion 51, and a second inclined surface 51 b is formed on the upper surface corner of the engagement protrusion 51.

  When the image forming unit 30 is pushed downward, the engagement protrusion 51 approaches the lock member 53 from above, and the upper end of the lock member 53 contacts the first inclined surface 51 a. As a result, a force in the arrow X direction is applied to the lock member 53, so the lock member 53 moves in the arrow X direction against the biasing force of the coil spring 55. Thereafter, when the first inclined surface 51a passes the front of the lock member 53, the lock member 53 is again protruded in the direction of the arrow X 'by the biasing force of the coil spring 55 and engaged with the second inclined surface 51b. Thereby, the imaging unit 30 is locked at a predetermined position.

  Next, the structure around the transport roller pair 40 will be described in detail.

  As shown in FIG. 2, the transport roller pair 40 is provided on the main body of the image forming apparatus 100. The paper feed roller 25, the registration roller pair 13 and the transfer roller 14 are also provided in the main body of the image forming apparatus 100.

  As shown in FIG. 6, a pressure change mechanism 60 that changes the nip pressure of the nip portion N of the conveyance roller pair 40 is provided above the conveyance roller pair 40. The pressure change mechanism 60 operates in conjunction with attachment / detachment of the imaging unit 30 to / from the main body of the image forming apparatus 100 as described later.

  The pressure change mechanism 60 includes an urging member 61 formed of a compression coil spring that urges the first roller 41 to the second roller 42 and an end (upper end) of the urging member 61 opposite to the first roller 41. And a pressing force changing member 62 disposed opposite to each other. The pressing force change member 62 is movable in a direction (vertical direction) in which the first roller 41 contacts and separates from the second roller 42, and the first position at which the nip pressure of the nip portion N is a first pressure A position shown in FIG. 7) and a second position (the position shown in FIG. 6) for setting the nip pressure of the nip portion N to a second pressure smaller than the first pressure. The first pressure is a pressure necessary for transporting the sheet, and the second pressure is a pressure capable of easily pulling out the sheet from the nip portion N when a sheet jam occurs.

  As shown in FIGS. 2 and 7, at a predetermined position of the unit housing 30a of the imaging unit 30, the imaging unit 30 is mounted on the main body of the image forming apparatus 100 (in the state of FIGS. 4 and 7). A pressing portion 31 is provided which presses the pressing force changing member 62 downward to arrange the pressing force changing member 62 at a first position (the position shown in FIG. 7). The lower surface (pressing surface) 31 a of the pressing portion 31 and the upper surface (pressing surface) 62 a of the pressing force changing member 62 are formed to extend in the horizontal direction.

  As shown in FIG. 8, the pressing force changing member 62 has a top surface 62a, a recess 62b in which the upper portion of the biasing member 61 is accommodated, and a projection 62c to which the upper end of the biasing member 61 is attached. And a pair of engaging portions 62d that project in the left and right direction 8 and engage with the edge of an opening hole 74 described later. Further, a pressing member 65 for pressing the rotating shaft 41 a downward is provided on the rotating shaft 41 a of the first roller 41. The pressing member 65 has a pair of wall portions 65a disposed on the left and right sides in FIG. 8 with respect to the rotation shaft 41a of the first roller 41, and a projection 65b to which the lower end portion of the biasing member 61 is attached.

  As shown in FIG. 2, the main body of the image forming apparatus 100 is provided with a conveyance guide member 70 disposed on the first roller 41 side (upper side) with respect to the sheet conveyance path 12 around the conveyance roller pair 40 and guiding the sheet. ing. As shown in FIGS. 9 and 10, the conveyance guide member 70 includes a plurality of ribs 71 forming the upper surface of the sheet conveyance path 12, a sheet feed roller accommodating portion 72 that accommodates the sheet feed roller 25, and the first roller 41. And a first roller accommodating portion 73 for accommodating. The first roller accommodating portion 73 is formed by cutting out a part of the rib 71.

  As shown in FIGS. 11 and 12, an opening hole 74 into which the pressing force changing member 62 is inserted is provided at the central portion of the first roller housing portion 73. The pressing force changing member 62 is inserted into the opening hole 74 from below and protrudes upward.

  In the image forming apparatus 100, the pressing force change member 62 is moved downward by the pressing unit 31 of the image forming unit 30 in the mounted state (the state of FIGS. 4 and 7) in which the image forming unit 30 is mounted on the image forming apparatus 100 main body. It is pressed by. At this time, the pressing force change member 62 is disposed at the first position, and the nip pressure of the nip portion N becomes the first pressure.

  On the other hand, when a paper jam occurs in the transport roller pair 40, the manual feed tray 11 (see FIG. 1) is opened, and the left end of FIG. 3 of the imaging unit 30 is lifted. ) Is released. Then, the imaging unit 30 is removed from the one side surface 100 a of the image forming apparatus 100 main body. In this removal state (the states of FIGS. 2 and 6), the pressing force changing member 62 is biased upward by the biasing member 61, and the engaging portion 62d engages with the edge of the opening hole 74. , Placed in the second position. Thereby, the nip pressure of the nip portion N becomes the second pressure. Then, the operator inserts a hand from one side 100 a of the main body of the image forming apparatus 100 and removes the jammed sheet.

  Thereafter, when mounting the imaging unit 30 on the main body of the image forming apparatus 100, the imaging unit 30 is inserted from one side 100a of the main body of the image forming apparatus 100 as shown in FIG. Then, with the rotary shaft 5a of the photosensitive drum 5 positioned by the bearing member 29, the hand is released from the imaging unit 30, and the self-weight of the imaging unit 30 centers on the rotary shaft 5a as shown in FIG. The imaging unit 30 rotates in the counterclockwise direction in FIG. Thus, the imaging unit 30 is held at a predetermined position by the lock mechanism 50, whereby the imaging unit 30 is mounted on the main body of the image forming apparatus 100 as shown in FIG. In the state where the rotational shaft 5a of the photosensitive drum 5 is positioned by the bearing member 29, the imaging unit 30 is moved counterclockwise in FIG. 3 around the rotational shaft 5a by pressing the imaging unit 30 downward. It may be rotated and mounted on the main body of the image forming apparatus 100.

  In the present embodiment, as described above, the pressure change mechanism 60 sets the nip pressure of the nip portion N as the first pressure in the mounting state of the imaging unit 30, and in the removal state of the imaging unit 30, The nip pressure is a second pressure smaller than the first pressure. As a result, the nip pressure of the nip portion N can be reduced from the first pressure to the second pressure in conjunction with the attachment / detachment of the image forming unit 30 at the time of jam treatment, so that the jam treatment property can be improved.

  Further, since it is not necessary to separately provide a drive source such as a motor to reduce the nip pressure of the nip portion N, it is possible to suppress the structure and control from being complicated.

  As described above, the jam clearance can be improved with a simple configuration.

  Further, as described above, the pressure change mechanism 60 is disposed so as to face the biasing member 61 and the end (upper end) opposite to the first roller 41 of the biasing member 61, and the first roller 41. Is movable in a direction in which the image forming unit 30 contacts or separates from the second roller 42, and is disposed at a first position where the nip pressure of the nip portion N is made the first pressure by mounting of the imaging unit 30. And a pressing force changing member 62 disposed at a second position for bringing the nip pressure of the nip portion N to a second pressure by removal. Thus, the pressure changing mechanism 60 can be easily configured to set the nip pressure of the nip N to the first pressure in the mounted state and to set the nip pressure of the nip N to the second pressure in the removal state. Can.

  Further, as described above, the pressing force change member 62 is disposed at the second position by being engaged with the conveyance guide member 70 by the biasing force of the biasing member 61 in the removal state. Thus, the nip pressure of the nip portion N can be easily made the second pressure in the removal state.

  Further, as described above, the image forming unit 30 is provided with the pressing portion 31 which presses the pressing force changing member 62 in the mounted state. As a result, the pressure change mechanism 60 can be easily operated in conjunction with attachment / detachment of the imaging unit 30 to / from the main body of the image forming apparatus 100.

  Further, as described above, the conveyance roller pair 40 is disposed immediately downstream of the sheet feeding roller 25 in the sheet feeding direction, and the image forming unit 30 is the main body of the image forming apparatus 100 with the manual feed tray 11 opened. It is comprised so that it may attach or detach from one side 100a. Thus, after the imaging unit 30 is removed from the main body of the image forming apparatus 100 at the time of jam processing, it is possible to easily remove the jammed sheet by inserting a hand from one side 100 a of the main body of the image forming apparatus 100.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is indicated not by the description of the embodiments described above but by the claims, and further includes all modifications within the meaning and scope equivalent to the claims.

  For example, although the example which applied this invention to the monochrome printer was shown in the said embodiment, this invention is not limited to this. Needless to say, the present invention can be applied to various image forming apparatuses such as color printers, monochrome and color copiers, multifunction machines, facsimiles, etc., each having an imaging unit and a pair of transport rollers.

  In the above embodiment, the image forming unit 30 includes the photosensitive drum 5, the developing device 8, and the toner container 9. However, the present invention is not limited to this. The imaging unit 30 may not have the developing device 8 and the toner container 9. The imaging unit 30 may also have the charging device 4 and the cleaning device 19.

  Moreover, although the example which applies this invention to the conveyance roller pair 40 arrange | positioned between the paper feed roller 25 and the registration roller pair 13 was shown in the said embodiment, this invention is not limited to this. For example, the present invention may be applied to the resist roller pair 13. Also, for example, the present invention may be applied to both the transport roller pair 40 and the resist roller pair 13.

  Further, although the lower surface 31a of the pressing portion 31 and the upper surface 62a of the pressing force change member 62 are formed to extend in the horizontal direction in the above embodiment, the present invention is not limited to this. For example, as in the image forming apparatus 100 according to the modification of the present invention shown in FIG. 13, the lower surface (pressing surface) 31a of the pressing portion 31 and the upper surface (pressing surface) 62a of the pressing force changing member 62 are made You may form so that it may incline toward the conveyance roller pair 40 side (lower side) toward the mounting direction downstream (right side of FIG. 13) of the image unit 30. FIG. According to this structure, in the mounting state of the imaging unit 30, a force always acts on the imaging unit 30 in the mounting direction downstream side (right side in FIG. 13). Can be suppressed.

  In the above embodiment, the pressure changing mechanism 60 is provided in the main body of the image forming apparatus 100. However, the present invention is not limited to this. The pressure changing mechanism for changing the nip pressure of the nip portion N is the imaging unit 30. It may be provided in In this case, the pressure change mechanism is disposed, for example, on the biasing member 61 that biases the first roller 41 to the second roller 42 and the end of the biasing member 61 on the first roller 41 side. May be movable in a direction in which the second roller 42 contacts or separates from the second roller 42 and may press a first roller 41.

5 Photosensitive drum (image carrier)
11 manual feed tray 12 paper transport path (recording medium transport path)
25 Feed roller (feed roller)
30 imaging unit 31 pressing portion 31 a lower surface (pressing surface)
40 conveyance roller pair 41 first roller 42 second roller 60 pressure changing mechanism 61 biasing member 62 pressing force changing member 62 a upper surface (pressure surface)
70 conveyance guide member 100 image forming apparatus 100 a one side N nip portion

Claims (6)

The device body,
An imaging unit having an image carrier that is detachable from the apparatus body and on which an electrostatic latent image is formed;
A transport roller pair provided on the apparatus main body and configured to nip and transport the recording medium, the transport roller pair comprising:
A pressure changing mechanism that operates in conjunction with mounting and demounting of the image forming unit with respect to the apparatus main body, and changes the nip pressure of the nip portion of the transport roller pair;
Equipped with
The pressure change mechanism sets a nip pressure of the nip portion as a first pressure in a mounted state in which the imaging unit is mounted on the apparatus body, and in a removal state in which the imaging unit is removed from the apparatus body An image forming apparatus, wherein a nip pressure of the nip portion is a second pressure smaller than the first pressure. The pressure change mechanism is
A biasing member for biasing the first roller to the second roller;
The biasing member is disposed opposite to the end of the biasing member opposite to the first roller, and the first roller is movable in a direction in which the first roller contacts or separates from the second roller. It is disposed at a first position where the nip pressure of the nip portion is brought to the first pressure by mounting, and is disposed at a second position where the nip pressure of the nip portion is brought to the second pressure by removing the imaging unit. Pressing force changing member,
The image forming apparatus according to claim 1, comprising: The recording medium conveyance path further includes a conveyance guide member disposed on the first roller side with respect to the recording medium conveyance path and guiding the recording medium.
3. The image forming apparatus according to claim 2, wherein the pressing force changing member is disposed at the second position by being engaged with the transport guide member by the biasing force of the biasing member in the removal state. apparatus.   The image forming apparatus according to claim 2, wherein the image forming unit is provided with a pressing unit configured to press the pressing force changing member in the mounting state and to arrange the pressing unit in the first position. . The pressing portion has a pressing surface for pressing the pressing force changing member,
The pressing force changing member has a pressed surface pressed by the pressing portion,
The image forming apparatus according to claim 4, wherein each of the pressing surface and the pressed surface is inclined toward the conveyance roller pair side toward the downstream side in the mounting direction of the image forming unit. A manual feed tray provided so as to be openable and closable with respect to one side surface of the device body;
A feed roller for feeding the recording medium on the manual feed tray;
And further
The transport roller pair is disposed immediately downstream of the feed roller in the feeding direction,
The image forming unit according to any one of claims 1 to 5, wherein the image forming unit is configured to be detached from the one side of the apparatus main body in a state in which the manual feed tray is opened. Image forming apparatus.

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