JP2015227908A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably and stably close an opening/closing door of an image forming apparatus.SOLUTION: An image forming apparatus includes: an image forming section; an opening/closing door 90 for turning with respect to a device body having the image forming section; a guide unit body 40 which forms a conveyance path of a recording material P and movably supported by the opening/closing door 90; a holding section (a holding projection 41, and a unit holding member 92) for holding the guide unit body 40 so as to open the conveyance path when the opening/closing door 90 is opened; a releasing section (a releasing projection 42, a releasing protrusion 152) for releasing the guide unit body 40 held by the holding section along with the operation for closing the opening/closing door 90; and a lock section (a transfer lock arm 110, a registration lock arm 120) for locking the guide unit body 40 when the opening/closing door 90 is closed. The releasing section releases the held guide unit body 40 before the start of locking of the locking section in process of the operation for closing the opening/closing door 90.

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a multifunction machine having an electrophotographic fax machine and a printer, and more particularly to an image forming apparatus having a maintenance door.

  In most image forming apparatuses, a configuration that can open and close the door including a conveyance function by an operation of removing the residual paper in the apparatus when a jam occurs, maintenance, or the like is adopted. Among these, what has various functions is proposed by interlocking with opening and closing of a door or a conveyance guide in a door using a link mechanism.

  For example, when a jam is detected, a necessary door is automatically opened according to a detection location. Among them, there has been proposed one in which a door is opened with a drive system including a link and an electromagnetic clutch, in which a gear is cut in a rack shape (see Patent Document 1).

  Also, when the door with the unit that holds the transport guide and the secondary transfer outer roller is opened and closed, and the door is closed using the shaft provided coaxially with the roller shaft on the secondary transfer guide unit. The position with respect to the main body is determined (see Patent Document 2). Further, the unit itself that holds the secondary transfer outer roller about its axis is also rotatable with respect to the door.

  In addition, there is a door comprising an exterior and a conveying device, and an intermediate conveying device is provided on the inside thereof, and when the door is opened, the intermediate conveying device is also opened to take out the paper remaining in the image forming unit ( (See Patent Document 3). Here, the intermediate transfer device is connected to a shutter for protecting a drum provided in the main body through a link, and the shutter is closed in conjunction with an operation for opening the door to protect the drum.

  In an image forming apparatus having a door as described above, an opening / closing door in which a conveyance guide and a secondary transfer outer roller (unit) (unit) are integrated with a door forming an exterior is a frame body of the apparatus main body. It rotates around the center of rotation provided. The opening / closing door is connected to the apparatus main body by a stopper member that regulates the opening angle. The internal unit is urged from the door to the inside by an elastic member disposed inside the door. For this reason, in a state where the door is opened, the internal unit is in a state of being separated from the door (floating state).

  The apparatus main body is provided with a cam-shaped arm member for storing the internal unit in a predetermined position and appropriately fixing the internal unit to the apparatus main body. Due to the presence of the arm member, when the open / close door is closed, the arm member pulls in and locks a part of the internal unit toward the apparatus main body. As a result, the secondary transfer roller and the conveyance roller attached to the door are accurately positioned with respect to the opposing roller disposed on the apparatus main body side.

JP 2006-36432 A JP 2008-216595 A JP 2008-261926 A

  However, in the case of an open / close door configuration in which the internal unit is in a float state with respect to the door as described above, the arm member stably performs the pull-in operation of the internal unit if the relative position of the internal unit to the door is different. Becomes difficult. Moreover, depending on the position of the internal unit in the float state, a load may be applied to the operation of retracting the arm member, which may increase the user's operating force when closing the door.

  Accordingly, an object of the present invention is to reliably and stably close an opening / closing door of an image forming apparatus.

  In order to achieve the above object, a typical configuration of the present invention includes an image forming unit, an opening / closing door that is rotatable with respect to an apparatus main body including the image forming unit, a recording material conveyance path, A guide unit that is movably supported by the door, a holding portion that holds the guide unit so that the conveyance path is opened when the door is opened, and an operation for closing the door. A release unit that releases the holding of the guide unit by the holding unit, and a lock unit that locks the guide unit in a closed state of the open / close door, and the release unit closes the open / close door. In the course of operation, before the lock by the lock unit is started, the holding of the guide unit is released.

  According to the present invention, the opening / closing door of the image forming apparatus can be reliably and stably closed.

FIG. 2 is a cross-sectional view illustrating the overall configuration of the image forming apparatus. The perspective view which shows the whole structure of an opening-and-closing door. The perspective view which shows the state which each unit assembled | attached to the door. The perspective view of an opening-and-closing door. The perspective view of a guide unit. The perspective view of a secondary transfer unit. The perspective view of a registration roller unit. The perspective view which shows the detailed structure of a stopper member. The figure which shows the rail shape of a guide rail part. The figure explaining the holding state of each unit hold | maintained at an opening-and-closing door. The figure explaining the state by which an opening / closing door is fixed with respect to the lock | rock part by the side of an apparatus main body. The perspective view which shows the detailed structure of the lock | rock part by the side of an apparatus main body. The figure explaining the state before and behind canceling | releasing holding | maintenance of a guide unit. The figure explaining the state of the stopper member before and behind releasing holding | maintenance of a guide unit. The flowchart which shows the operation order of guide unit holding | maintenance.

(Image forming device)
The overall configuration of the image forming apparatus 100 will be described. FIG. 1 is a cross-sectional view showing the overall configuration of the image forming apparatus. The image forming apparatus 100 includes image forming portions for yellow (Y), magenta (M), cyan (C), and black (K). The configuration of the image forming unit for each color does not differ depending on the toner color to be stored. For this reason, in the following description, Y, M, C, and K subscripts are omitted.

  The surface of the photosensitive drum 11 (image carrier) is uniformly charged by the charging roller 12, and then an electrostatic latent image is formed by the laser scanner 13 driven based on the transmitted image information signal. The The electrostatic latent image is made visible as a toner image by the developing device 14.

  The toner image on the photosensitive drum 11 is sequentially transferred (primary transfer) to the intermediate transfer belt 61 (intermediate transfer member) by applying a predetermined pressure and electrostatic load bias by the primary transfer roller 17. . A small amount of residual toner remaining on the photosensitive drum 11 after the primary transfer is removed and collected by the drum cleaner 15 to prepare for the next image formation again. The intermediate transfer belt 61 is unitized integrally with a plurality of stretching rollers including a driving roller 62 that stretches the intermediate transfer belt 61, and constitutes an intermediate transfer unit 60.

  On the other hand, the recording material P is fed one by one from the feeding cassette 2 and conveyed through the main conveyance path 71 while being sandwiched between two conveyance rollers of a registration roller pair (registration counter roller 3 and registration driving roller 25). The In the nip portion of the registration roller pair, the skew of the recording material P is corrected by forming a loop at the tip of the recording material P. Thereafter, the registration roller pair synchronizes with the toner image on the intermediate transfer belt 61, and the recording material P is interposed between the driving roller 62 that drives the intermediate transfer belt 61 and the secondary transfer roller 35 (secondary transfer member). Transport. The secondary transfer roller 35 is integrally assembled with a secondary transfer unit 30 described later, and is separated from the drive roller 62 when the open / close door 90 is opened.

  A predetermined pressing force and an electrostatic load bias are applied to the nip portion between the driving roller 62 and the secondary transfer roller 35 disposed to face each other. As a result, the color toner image on the intermediate transfer belt 61 is transferred (secondary transfer) to the recording material P. After the transfer, a slight residual toner remaining on the intermediate transfer belt 61 is removed and collected by the belt cleaner 7 to prepare for the next image formation again.

  The toner image transferred onto the recording material P is fixed by being heated and pressed by the fixing device 4 (fixing unit), and is discharged onto the discharge tray 6 by the discharge roller pair 5. When images are formed on both sides of the recording material P, the discharge roller pair 5 is reversed to pass through the duplex conveying path 72. The color toner image on the intermediate transfer belt 61 is transferred to the recording material P guided by the double-sided conveyance path 72 to form images on both sides of the recording material P.

  An opening / closing door 90 that can be opened and closed with respect to the apparatus main body is formed on the side surface of the image forming apparatus 100 shown in FIG. The open / close door 90 rotates about a rotation center 90a disposed below the door 90. Further, a locking portion 90b is formed above the opening / closing door 90, and the locking portion 90b is locked to a locking portion formed on the image forming apparatus 100 main body (apparatus main body). By being locked by the locking portion 90b, the opening / closing door 90 is closed with respect to the apparatus main body. A guide rail portion 93 is provided on a side surface of the opening / closing door 90, and an opening angle of the opening / closing door 90 with respect to the image forming apparatus 100 is restricted by a stopper member 150 (a rotation restricting member) described later provided in the apparatus main body. It is configured.

  As will be described in detail later, inside the opening / closing door 90, a guide unit in which a conveyance path for the recording material P is formed on the front and back is disposed. The guide unit body 40 is disposed so as to be rotatable (movable) with respect to the opening / closing door 90 about the rotation center 40a. Further, the secondary transfer unit 30 is disposed integrally with the guide unit body 40 inside the guide unit body 40. The one-piece configuration is such that the longitudinal end of the secondary transfer unit 30 and the longitudinal end of the guide unit main body 40 are loosely fitted to each other.

  A floating spring 32 (biasing member) is disposed between the secondary transfer unit 30 and the guide unit main body 40. As a result, the secondary transfer unit 30 is biased from the guide unit main body 40 toward the intermediate transfer unit 60, and the guide unit main body 40 holds the secondary transfer unit 30 in a so-called float state.

  A main conveyance path 71 is formed by a conveyance guide provided in the apparatus main body and the secondary transfer unit 30. Further, a registration roller unit 20 (roller unit) is disposed below the secondary transfer unit 30 and on the conveyance path side of the recording material P. The registration roller unit 20 is loosely fitted to the lower portion of the guide unit main body 40 and is disposed integrally with the guide unit main body 40. The registration roller unit 20 is disposed to face the registration facing roller 3 on the apparatus main body side, and corrects the posture of the recording material P so that the recording material P in the conveyance path does not skew. The guide unit main body 40, the secondary transfer unit 30, and the registration roller unit 20 constitute a guide unit of the present invention.

(Configuration and operation around the door)
The configuration and operation of the unit disposed inside the opening / closing door 90 will be schematically described. FIG. 2 is a perspective view showing the overall configuration of the open / close door. 2A shows a state in which the opening / closing door 90 is completely closed, FIG. 2B shows a state in which the opening / closing door 90 is partially opened, and FIG. 2C shows a state in which the opening / closing door 90 is completely opened. (A) shows the state of the door 90 during normal operation or image forming operation, (b) during jam processing, and (c) the state of the door 90 during unit replacement.

  As described above, the opening / closing door 90 is configured integrally with the registration roller unit 20, the secondary transfer unit 30, and the guide unit main body 40. A double-sided conveyance path 72 is formed between the opening / closing door 90 and the guide unit main body 40. As shown in FIG. 2, the open / close door 90 rotates about a rotation center 90a. With the open / close door 90 open, the registration roller unit 20, the secondary transfer unit 30, and the guide unit main body 40 integrally rotate with respect to the open / close door 90, whereby the double-sided conveyance path 72 is opened.

  The opening angle of the opening / closing door 90 is regulated by a stopper member 150 that is disposed in the apparatus main body and rotates about a rotation center 150a. Specifically, a rail is formed on the guide rail portion 93 on the side surface of the opening / closing door 90, and a restriction boss disposed on the stopper member 150 is engaged with the rail. Therefore, the stopper member 150 allows the opening / closing door 90 to rotate only within a range in which the restriction boss can move in the rail.

(Detailed configuration of members around the door)
A detailed configuration of each of the above-described members assembled integrally with the opening / closing door 90 will be described in order with reference to FIGS.

  FIG. 3 is a perspective view showing a state in which each unit is assembled to the door. As shown in FIG. 3, each unit of the registration roller unit 20, the secondary transfer unit 30, and the guide unit main body 40 is integrally assembled with the opening / closing door 90. In addition, as shown in FIG. 3, a part of the surface side of each unit constitutes a conveyance path for the recording material P.

  FIG. 4 is a perspective view of the door. As can be seen with reference to FIG. 4 showing the state of the opening / closing door 90 excluding each unit, the inner surface of the opening / closing door 90 is provided with a double-sided conveyance path and rollers that enable the double-sided conveyance of the recording material P. The

  As shown in FIGS. 3 and 4, the lower side surface of the opening / closing door 90 is provided with a rotation center 90 a protruding so as to rotate with respect to the apparatus body, and a guide rail above the rotation center 90 a. A portion 93 is provided. Further, a locking portion 90b that locks against the apparatus main body is disposed on the upper side surface.

  Further, the rotation support portion 91 is configured to protrude from the side of the guide rail portion 93 in the apparatus internal direction. The rotation support part 91 supports the rotation center 40a arrange | positioned at the lower end of the guide unit main body 40 shown in FIG. 3 so that rotation is possible. With this configuration, the guide unit main body 40 rotates around the rotation center 40a while being supported by the rotation support portion 91 at the lower end.

  Further, a unit holding member 92 is disposed by an elastic member on the side in the apparatus internal direction near the upper end of the guide rail portion 93. The unit holding member 92 holds a holding projection 41 formed on the guide unit main body 40 as will be described later.

  FIG. 5 is a perspective view of the guide unit main body 40. In FIG. 5, it is seen from the side where the double-sided conveyance path is present, that is, from the back side of the recording material P. As shown in FIG. 5, the guide unit main body 40 has a projecting rotation center 40a at the lower end of the side surface. Since the rotation center 40 a is supported by the rotation support portion 91 of the opening / closing door 90, the guide unit body 40 is interlocked with the opening / closing door 90.

  Further, two protrusions (holding protrusion 41 and releasing protrusion 42) that protrude in the width direction of the transport path are disposed slightly above the rotation center 40a. The holding projection 41 is arranged at a position where the unit holding member 92 can come into contact, and the release projection 42 is arranged at a position where a release projection 152 (described later) of the stopper member 150 can come into contact.

  As shown in FIG. 5, a plurality of engagement holes (transfer unit upper engagement hole 40b, transfer unit lower engagement hole 40c, registration roller engagement hole 40d) are formed on both side surfaces of the guide unit main body 40. . The transfer unit upper engagement hole 40b and the transfer unit lower engagement hole 40c are engaged with the secondary transfer unit 30, and the registration roller engagement hole 40d is a bearing 26 of the registration driving roller 25 of the registration roller unit 20 (see FIG. 7). ).

  A plurality of guide portions are formed on both side surfaces of the guide unit main body 40 to assist the rotation of the plurality of lock arms (transfer lock arm 110 and registration lock arm 120) disposed in the apparatus main body. . Specifically, it has two inclined surfaces: an upper arm guide 43 that guides the distal end portion of the transfer lock arm 110 and a lower arm guide 44 that guides the distal end portion of the registration lock arm 120.

  FIG. 6 is a perspective view of the secondary transfer unit. (A) is the figure seen from the surface side, (b) is the figure seen from the back surface side. As shown in FIG. 6A, the secondary transfer unit 30 is a unit that pivotally supports the secondary transfer roller 35 facing the drive roller 62 (see FIG. 1). Before and after the secondary transfer roller 35 is a conveyance path on the surface side of the recording material P.

  In addition, on both side surfaces of the secondary transfer unit 30, an upper positioning protrusion 30a and a plurality of engaging protrusions (upper engaging protrusion 30b and lower engaging protrusion 30c) are formed. The positioning protrusion 30 a is positioned by the transfer lock arm 110. The upper engagement protrusion 30b engages with the transfer unit upper engagement hole 40b of the guide unit main body 40, and the lower engagement protrusion 30c engages with the transfer unit lower engagement hole 40c.

  Further, as shown in FIG. 6B, a floating spring 32 for urging the secondary transfer unit 30 in a direction away from the guide unit main body 40 is disposed on the back surface of the secondary transfer unit 30. As described above, the secondary transfer unit 30 is engaged with the guide unit main body 40 and is biased toward the side separated by the floating spring 32, so that the secondary transfer unit 30 is against the guide unit main body 40. It is held in a float state that floats.

  FIG. 7 is a perspective view of the registration roller unit. The registration roller unit 20 includes a registration driving roller 25 and a driving gear 27 attached coaxially thereto. The drive gear 27 is driven by a motor (drive unit) (not shown). The registration roller unit 20 is held by the bearings 26 at both ends of the registration driving roller 25 engaging with the transfer unit lower engagement hole 40 c of the guide unit main body 40.

  FIG. 8 is a perspective view showing a detailed configuration of the stopper member. In FIG. 8, the stopper member 150 is viewed from the back surface (the surface on the side engaged with the opening / closing door 90). As shown in FIG. 2, the stopper member 150 rotates around the rotation center 150 a and regulates the opening angle of the open / close door 90.

  The stopper member 150 is formed with a projecting portion called a restricting boss 151 and a release projecting portion 152 (hooking portion) at the end opposite to the position of the rotation center 150a. The restriction boss 151 restricts the rotation angle of the open / close door 90 by engaging with the guide rail portion 93. The release protrusion 152 is a protrusion for releasing the separation of the guide unit main body 40 from the opening / closing door 90 with the configuration described later.

  FIG. 9 is a view showing the rail shape of the guide rail portion. As shown in FIG. 9, a guide rail portion 93 is formed on the side surface of the opening / closing door 90. A guide rail 93 a for guiding the restriction boss 151 of the stopper member 150 is formed on the guide rail portion 93. The rail shape of the guide rail 93a is bifurcated at a branch C. A rotation restriction position A and a rotation restriction position B are formed at the tip of the branch.

  Thus, since the guide rail 93a branches and there are two rotation restricting positions, the open / close door 90 can be opened or closed selectively or in two stages. That is, when the restriction boss 151 of the stopper member 150 slides on the guide rail 93a and is guided to the rotation restriction position A, the opening / closing door 90 is held halfway open as shown in FIG. Is done. In this case, since the opening / closing door 90 is held at an angle at which paper can be easily taken out from above, it is easy to perform jam processing. Further, when the restriction boss 151 of the stopper member 150 is guided to the rotation restriction position B, the opening / closing door 90 is fully opened as shown in FIG. It becomes easier to do.

  FIG. 10 is a diagram for explaining a holding state of each unit held by the opening / closing door. (A) is a side view which shows the state by which each unit was hold | maintained, (b) is an enlarged view of the unit holding member 92. FIG.

  As shown in FIG. 10A, the secondary transfer unit 30 is engaged with the guide unit main body 40 at two locations. Specifically, the upper engagement protrusion 30b of the secondary transfer unit 30 is loosely fitted inside the transfer unit upper engagement hole 40b of the guide unit main body 40, and the lower engagement protrusion 30c is engaged with the transfer unit lower engagement hole. The fitting hole 40c is loosely fitted inside. The secondary transfer unit 30 is urged leftward in the figure by a floating spring 32 disposed between the guide unit body 40 and the secondary transfer unit 30.

  Further, the bearing 26 of the registration driving roller 25 of the registration roller unit 20 is engaged with the registration roller engagement hole 40d. Retained. As a result, the registration roller unit 20 is also held integrally with the guide unit main body 40.

  Further, the guide unit main body 40 is held by the opening / closing door 90 at two places, that is, a rotation support portion 91 and a unit holding member 92. That is, the rotation support part 91 opened in a C shape holds the rotation center 40 a disposed at the lower end of the guide unit body 40. Further, the unit holding member 92 holds the holding protrusion 41 of the guide unit main body 40 on the surface side. Here, a concave portion 92D is formed in a portion of the unit holding member 92 that holds the holding projection 41. For this reason, when the opening / closing door 90 is opened, the holding projection 41 is caught in the recess 92D, and the opening state of the guide unit main body 40 is easily held.

(Engagement structure of the door to the device body)
FIG. 11 is a diagram illustrating a state in which the open / close door is fixed to the lock portion on the apparatus main body side. (A) is a state immediately before a lock part starts engagement with an opening-and-closing door, (b) is a state which the lock part completed the lock | rock with respect to an opening-and-closing door. The outline of the lock part is as follows.

  As shown in FIG. 11, the apparatus main body is provided with two lock portions, a transfer lock arm 110 (first lock portion) and a registration lock arm 120 (second lock portion). The transfer lock arm 110 is engaged with the positioning protrusion 30 a at the upper end of the secondary transfer unit 30, and the registration lock arm 120 is engaged with the bearing 26 of the registration roller unit 20.

  FIG. 12 is a perspective view showing a detailed configuration of the lock portion on the apparatus main body side. (A) is the transfer lock arm 110, and (b) is the resist lock arm 120. As shown in FIG. 12, the transfer lock arm 110 is rotated about a rotation center 110a, the tip is moved by being guided by the guide protrusion 111, and the positioning protrusion 30a is moved by the arm-shaped lock portion 112. Lock it. The registration lock arm 120 rotates about the rotation center 120 a, the tip is moved by being guided by the guide protrusion 121, and the bearing 26 is locked by the arm-shaped lock portion 122.

  With this configuration, the lock unit operates as follows. First, as shown in FIG. 11A, before the opening / closing door 90 is closed, the lower end of the transfer lock arm 110 is supported by the lower end restricting portion 119 disposed in the apparatus main body. Similarly, the lower end of the registration lock arm 120 is also supported by the lower end restricting portion 129 disposed in the apparatus main body.

  When the opening / closing door 90 is closed, the guide protrusion 111 of the transfer lock arm 110 abuts on the upper arm guide 43 formed on the guide unit main body 40. Then, as the open / close door 90 is closed, the guide protrusion 111 is guided in the direction of the arrow. As a result, the transfer lock arm 110 rotates counterclockwise. Similarly, the guide protrusion 121 of the registration lock arm 120 abuts on the lower arm guide 44 formed on the guide unit main body 40. Then, as the open / close door 90 is closed, the guide protrusion 121 is guided in the direction of the arrow. As a result, the registration lock arm 120 rotates counterclockwise.

  As shown in FIG. 11B, when the open / close door 90 is closed, the guide protrusion 111 of the transfer lock arm 110 moves to the upper end of the upper arm guide 43. In this state, the lock portion 112 engages with the positioning protrusion 30 a of the secondary transfer unit 30. Thus, the transfer lock arm 110 positions the upper part of the secondary transfer unit 30. On the other hand, the guide protrusion 121 of the registration lock arm 120 also moves to the upper end of the lower arm guide 44. In this state, the lock portion 122 is engaged with the bearing 26 of the registration driving roller 25. In this way, the registration lock arm 120 positions the registration roller unit 20.

(Behavior immediately before the guide unit reaches the lock member)
Next, the behavior immediately before the guide unit main body 40 reaches the two lock members (transfer lock arm 110 and registration lock arm 120) disposed in the apparatus main body when the door is closed will be described with reference to FIG. To do. FIG. 13 is a diagram illustrating a state before and after releasing the holding of the guide unit. (A) is a state in which the guide unit body 40 is held by the unit holding member 92, and (b) is a view showing a state in which the holding of the guide unit body 40 by the unit holding member 92 is released.

  The rotation center 90a of the opening / closing door 90 is different from the rotation center 40a of the guide unit body 40. Further, as shown in FIG. 13A, the guide unit main body 40 is in a state of being separated from the open / close door 90 when the open / close door 90 is closed. For this reason, two guide portions (upper arm guide 43 and lower arm guide 44) formed in the guide unit main body 40 and two lock members (transfer lock arm 110 and registration lock arm 120) formed in the apparatus main body. The relative position is different.

  Conventionally, in order to reliably perform the positioning operation of the opening / closing door with respect to the apparatus body, the shape of the guide member on the opening / closing door side and the shape of the lock member on the apparatus body side have been optimized. However, even if optimization is performed, it is difficult to sufficiently improve the operability of the open / close door, and there is a problem that a load is applied to related parts.

  Therefore, in the present embodiment, the following structure is employed in order to improve the operability of the open / close door while reliably performing the positioning operation of the open / close door with respect to the apparatus main body. That is, when closing the opening / closing door 90, the separation of the guide unit body 40 from the opening / closing door 90 is released immediately before positioning by the lock member.

  More specifically, when the opening / closing door 90 is closed, the opening / closing door 90 and the guide unit shown in FIG. 13B are separated from the state where the opening / closing door 90 and the guide unit main body 40 shown in FIG. It will be in the state which the main body 40 contact | abutted. In this state, the upper arm guide 43 is in a position close to the transfer lock arm 110, and the lower arm guide 44 is in a position close to the registration lock arm 120. As a result, the positioning operation of the secondary transfer unit 30 and the registration roller unit 20 by the transfer lock arm 110 and the registration lock arm 120 can always be performed under the same conditions.

(Detailed configuration for releasing the guide unit)
As described above, in this embodiment, before the positioning by the lock member is performed, the separation of the guide unit body 40 from the open / close door 90 is released. This configuration will be described in more detail with reference to FIG. FIG. 14 is a diagram illustrating the state of the stopper member before and after releasing the holding of the guide unit. (A) shows a state where the guide unit main body 40 is held by the unit holding member 92, and (b) shows a state where the holding of the guide unit main body 40 by the unit holding member 92 is released. For the sake of explanation, the stopper member 150 is shown in FIG. 14 so that the state of the guide unit main body 40 can be understood.

  As shown in FIG. 14A, when the open / close door 90 is closed, the restriction boss 151 of the stopper member 150 engaged with the guide rail portion 93 is guided to the guide rail 93a and moves upward. Accordingly, the release projection 152 also moves. At this time, the release projection 152 is caught by the release projection 42 of the guide unit main body 40. Then, the release protrusion 152 presses the release protrusion 42, and the holding protrusion 41 disposed adjacent to the release protrusion 42 is also indirectly pressed. Then, the holding projection 41 held in the recess 92D presses the unit holding member 92 in the direction of the arrow to elastically deform it, and releases the engagement with the recess 92D.

  Thereafter, the holding protrusion 41 moves so as to sink under the unit holding member 92 as shown in FIG. Since the holding projection 41 is configured integrally with the guide unit main body 40, the guide unit main body 40 released from being held by the unit holding member 92 of the holding projection 41 is on the side of the open / close door 90 with the rotation center 40a as the center. Move to. When the guide unit is rotated so as to open the double-sided conveyance path 72 after the opening / closing door 90 is opened, the holding projection 41 elastically deforms the unit holding member 92, and the holding projection 41 is eventually engaged with the recess 92D. Match. As a result, the guide unit is held in the open position.

  As a result, the guide unit main body 40 falls to the opening / closing door 90 side, and as shown in FIG. 13B, the upper arm guide 43 and the lower arm guide 44 of the guide unit main body 40 reliably transfer the transfer lock arm 110 and the resist. The lock arm 120 can be guided.

  The above sequence of operations is shown. FIG. 15 is a flowchart showing the operation order for holding the guide unit. As shown in FIG. 15, when the opening / closing door 90 is closed (step S1), it becomes a problem whether the guide unit main body 40 is held by the unit holding member 92 of the opening / closing door 90 (step S2).

  When the open / close door 90 is held by the unit holding member 92, the release protrusion 152 of the stopper member 150 contacts and presses the release protrusion 42 of the guide unit body 40 as shown in FIG. 14. Then, the holding protrusion 41 configured integrally with the release protrusion 42 elastically deforms the unit holding member 92, and the holding protrusion 41 is detached from the recess 92 </ b> D and is retracted below the unit holding member 92. Then, the holding of the guide unit main body 40 by the unit holding member 92 is released (step S3).

  After step S3 or when the door 90 is not held by the unit holding member 92 in step S2, the two lock members (transfer lock arm 110 and registration lock arm 120) rotate and start the positioning operation ( Step S4). Then, as shown in FIG. 11, the upper arm guide 43 guides the guide protrusion 111 and the lower arm guide 44 guides the guide protrusion 121, thereby completing the positioning operation (step S5). Thereby, the opening / closing door 90 is fixed with respect to the apparatus main body (step S6).

  As described above, in this embodiment, the holding of the guide unit main body 40 by the opening / closing door 90 is released immediately before the positioning operation by the transfer lock arm 110 and the registration lock arm 120 is started. Thereby, the upper arm guide 43 and the lower arm guide 44 of the guide unit main body 40 can be reliably guided to the transfer lock arm 110 and the registration lock arm 120. Since the lock member is reliably guided to each guide, the operation force does not become too large. Therefore, the open / close door of the image forming apparatus can be reliably and stably closed.

  As described above, when the opening / closing door 90 is opened, the guide unit main body 40 is held in a state of being separated from the opening / closing door 90 by the holding portions (holding protrusion 41, unit holding member 92). On the other hand, when closing the opening / closing door 90, in conjunction with the closing operation, the holding of the guide unit body 40 with respect to the opening / closing door 90 is released by the action of the release portion (the release protrusion 42, the release protrusion 152).

  In the process of closing the open / close door, the holding of the guide unit main body 40 is released by pressing the release protrusion 42 of the release protrusion 152, but the timing is just before the lock portion starts to be locked. . Then, at the stage where the locking operation of the lock portion starts, the holding of the guide unit body 40 is always released, and the guide unit body 40 is in contact with the open / close door 90. For this reason, the open / close door is reliably and stably closed.

P ... Recording material 20 ... Registration roller unit 25 ... Registration drive roller 30 ... Secondary transfer unit 35 ... Secondary transfer roller 40 ... Guide unit body 41 ... Holding projection 42 ... Release projection 90 ... Opening / closing door 90a ... Center of rotation 91: Rotating support portion 92 ... Unit holding member 93 ... Guide rail portion 93a ... Guide rail 100 ... Image forming apparatus 110 ... Transfer lock arm 120 ... Registration lock arm 150 ... Stopper member 152 ... Release protrusion

Claims (6)

An image forming unit;
An openable / closable door rotatable with respect to the apparatus main body including the image forming unit;
A guide unit that forms a recording material conveyance path and is movably supported by the door;
A holding unit that holds the guide unit so that the conveyance path is opened when the opening and closing door is opened;
A release unit that releases the holding of the guide unit by the holding unit in conjunction with an operation of closing the opening and closing door;
A lock portion for locking the guide unit in a closed state of the door;
Have
The image forming apparatus according to claim 1, wherein the release unit releases the holding of the guide unit before the locking by the lock unit is started in the process of closing the door. The guide unit holds a transfer unit that includes a transfer roller that transfers the toner image formed by the image forming unit in the transfer unit, and a roller unit that includes a transport roller that transports a recording material to the transfer unit. And
The image forming apparatus according to claim 1, wherein the lock unit includes a first lock member that positions the transfer unit and a second lock member that positions the roller unit. A rotation restricting member for restricting a rotation angle of the door while being guided by a guide rail disposed on a side surface of the door;
The holding portion includes a part of the holding projection of the guide unit, and a unit holding member that is disposed on the opening / closing door and engages the holding projection,
The release portion includes a part of a release protrusion of the guide unit, and a hook portion that is disposed on the rotation restricting member and releases the engagement by hooking the release protrusion. The image forming apparatus according to claim 1.   The image forming apparatus according to claim 2, further comprising an urging member that urges the transfer unit and the guide unit in a direction to separate the transfer unit and the guide unit.   5. The image forming apparatus according to claim 2, wherein the transport roller of the roller unit is a roller attached to a driving unit to correct skew of the recording material.   The guide rail is divided into two forks so that the opening angle of the door can be selectively switched between a first opening angle and a second opening angle larger than the first opening angle. The image forming apparatus described in 1.

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