JP2012225963A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of performing jam processing of a fixing part with simple operations even though it includes a paper reverse conveying passage.SOLUTION: An image forming device 100 includes: a reverse guide member 62 which is disposed so as to cover a fixing part 14 on the upper side of a device body 2 and in which a paper conveying passage 11 is formed by a conveying guide surface 62a while a reverse conveying passage 16 is formed by a reverse guide surface 62b facing the conveying guide member 62a on the opposite side; an upper surface cover 51 which is rotatably supported with regard to the upper surface of the device body 2 and can open/close the upper surface of the device body 2 by rotation; and a driving mechanism 70 which swings the reverse guide member 62 so that the fixing part 14 is exposed from the reverse guide member 62 in association with rotation of the upper surface cover 51 in the opening direction.

Description

The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a composite machine thereof, and more particularly to an image forming apparatus having a jam processing mechanism of a fixing unit located above the apparatus.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a printer or a multifunction peripheral, an image forming process is performed in an image forming unit, and a sheet on which a toner image is transferred by the image forming unit is formed along a sheet conveyance path formed in a vertical direction. The toner image is fixed on the paper by the fixing unit arranged above the paper conveyance path, and then the paper is discharged to the discharge unit provided above the fixing unit. There is. In such a configuration, the side cover is normally provided on the side wall of the apparatus main body of the image forming apparatus so as to be openable and closable, and the sheet conveyance path and the fixing unit are disposed immediately inside the side cover. Therefore, when a paper jam occurs in the paper conveyance path or the fixing unit, the position where the paper jam occurs is exposed to the outside by opening the side cover, so that the paper jam clearing operation can be easily performed. .

  For example, in the image forming apparatus described in Patent Document 1, a sheet carrying path on which a toner image is formed is conveyed in a vertical direction toward a fixing unit, and a sheet after fixing processing is discharged to the upper part of the apparatus main body. A state change mechanism that changes the state between a pressurization state and a pressure release state by a pressure roller in conjunction with the opening / closing operation of the side cover, and a side cover that can be freely opened and closed to cover the discharge unit, the paper conveyance path and the fixing unit And comprising. When the side cover is closed, the state change mechanism is set to the pressurized state and fixing processing is possible, and when the side cover is opened, the state change mechanism is set to the release state of pressure and the paper jam at the fixing unit is eliminated. The operation can be performed.

JP 2008-122744 A (Patent Claim, FIG. 1)

  In recent years, image forming apparatuses such as printers and multifunction peripherals have become capable of duplex printing. In order to enable double-sided printing, together with a paper transport path that transports the fixed paper after image formation to the discharge section, a reverse transport path that reverses the image-formed paper on one side and transports it again to the image forming section is required. The reverse conveyance path is a conveyance path that branches from the sheet conveyance path between the fixing unit and the discharge unit and again faces the image forming unit, and is usually formed between the sheet conveyance path that extends in the vertical direction and the side cover. The In the image forming apparatus having such a configuration, when a paper jam occurs in the fixing unit, the fixing unit is disposed at the back of the reverse conveyance path even if the side cover is opened for jamming. There was a problem that it was difficult to remove the paper jammed in the section.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of performing jam processing of a fixing unit with a simple operation even if a paper reverse conveyance path is provided. Objective.

  In order to achieve the above object, an image forming apparatus according to a first aspect of the present invention includes an image forming unit that transfers a toner image formed on an image carrier onto a recording medium, and the image forming unit that transfers the toner image onto the recording medium. A fixing unit that melts and fixes the toner image on the recording medium, a discharge unit that discharges the recording medium on which the toner image is fixed by the fixing unit, and a conveyance of the recording medium from the image forming unit to the discharge unit. A reversing conveyance path for reversing a recording medium that is extended along the upper and side surfaces of the apparatus main body and on which image formation has been performed, and reconveying to the image forming unit, A reversing guide surface is disposed on the upper side of the apparatus body so as to be able to swing so as to cover the fixing unit, and forms a part of the sheet transport path on the transport guide surface, while facing the opposite side of the transport guide surface. To form a part of the reverse conveying path. A guide member, an upper surface cover that is pivotally supported with respect to the upper surface of the apparatus main body, and that can open and close the upper surface of the apparatus main body by a rotation operation; And a drive mechanism that swings between a position that exposes the fixing unit and a position that covers the fixing unit.

  According to a second aspect of the present invention, in the above image forming apparatus, the drive mechanism is separated from the first rotation shaft that forms the swing center of the reversing guide member by a first distance from the first rotation shaft. A first engaging portion provided on the reversing guide member, a second rotating shaft constituting a rotation center of the upper surface cover, and a second distance away from the second rotating shaft. A second engagement portion that is provided and engageable with the first engagement portion, and the second engagement portion is coupled to the second engagement portion in conjunction with a rotation operation of the upper surface cover in the opening direction. By rotating about a rotation axis, the first engagement portion is lifted, and the reversing guide member swings about the first rotation axis.

  According to a third aspect of the present invention, in the above image forming apparatus, the first engagement portion is formed in a concave shape whose lower surface is an engagement surface, and the second engagement portion is associated with the first engagement portion. It is characterized by being formed in a hook shape having an upper surface capable of abutting against the mating surface.

  According to a fourth aspect of the present invention, in the above image forming apparatus, the first distance is configured to be smaller than the second distance.

  According to a fifth aspect of the present invention, in the above image forming apparatus, the side surface of the apparatus main body is rotatably supported with respect to the side surface of the apparatus main body, and the side surface of the apparatus main body can be opened and closed by rotating operation. The reversing guide member is further provided with a side cover that exposes the conveyance path from the apparatus main body, and the upper surface cover is configured to open the side cover side by rotating the upper surface cover in the opening direction. Is characterized in that the fixing portion is configured to be exposed from the apparatus main body toward the side cover side.

  According to a sixth aspect of the present invention, in the above image forming apparatus, the upper surface cover includes a cover member that forms an upper surface of the apparatus main body, and a conveyance guide member that is disposed to face the reversing guide surface. It is a feature.

  According to the first invention, when a paper jam occurs in the fixing unit, when the upper surface cover that covers the upper surface of the apparatus main body is opened, it is reversed by the drive mechanism in conjunction with the rotation operation of the upper surface cover in the opening direction. The guide member swings, and the fixing portion covered with the reverse guide member is exposed from the reverse guide member. In this state, the recording medium jammed in the fixing unit can be removed. Therefore, even if a reverse conveyance path is provided for double-sided printing, jamming of the fixing unit can be performed with a simple operation.

1 is a diagram schematically illustrating an overall configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a plan view showing the periphery of the fixing unit of the image forming apparatus according to the embodiment. FIG. 3 is a perspective view illustrating a reverse guide member of the image forming apparatus according to the embodiment. 1 is a perspective view showing a top cover of an image forming apparatus according to an embodiment. The perspective view which shows the cover member of the upper surface cover which concerns on embodiment The perspective view which shows the conveyance guide member of the upper surface cover which concerns on embodiment Sectional drawing which shows typically the drive mechanism of the image forming apparatus which concerns on embodiment FIG. 3 is a plan view showing the periphery of the fixing unit in a state where the upper surface cover of the image forming apparatus according to the embodiment is opened.

  Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments. Further, the use of the invention and the terms shown here are not limited thereto.

  FIG. 1 is a diagram illustrating an overall configuration of an in-body discharge type image forming apparatus. Under the image forming apparatus 100, a cassette type paper feeding unit 10 is disposed. The paper feeding unit 10 has upper and lower two-stage paper feeding cassettes 10a and 10b, and sheets before printing are stacked and stored in the paper feeding cassettes 10a and 10b. The paper stored in the paper cassettes 10a and 10b is fed out one by one from the selected paper cassette 10a (10b) by the paper pickup roller 10d (10e), and the fed paper is sent out to the paper transport path 11. It is.

  A manual feed tray 10 c is disposed on the right side surface of the image forming apparatus 100. The manual feed tray 10c can be loaded with paper having a size different from that of the paper feed cassettes 10a and 10b. The paper placed on the manual feed tray 10 c is sent out to the paper transport path 11.

  The sheet conveyance path 11 extends in the vertical direction of the apparatus main body 2 on the left side of the sheet feeding unit 10. The sheet fed from the sheet feeding unit 10 is conveyed to the registration roller pair 12 above the sheet conveying path 11. The registration roller pair 12 sends the paper toward the image forming unit 3 in synchronization with the timing of transferring the toner image onto the paper.

  A document reading device 6 is disposed above the image forming apparatus 100, and a platen (document pressing) 24 is provided on the upper surface of the document reading device 6 so as to be openable and closable. Is attached. When copying an original, the originals placed on the original conveying device 27 are separated one by one and sent to the original reading unit, and the original reading device 6 reads the image data of the original.

  An image forming unit 3 is disposed substantially at the center of the image forming apparatus 100. The image forming unit 3 includes a photoconductor 5 that is an image carrier, and further, around the photoconductor 5 in order along its rotation direction (A direction in the drawing), a charging unit 4, an exposure unit 7, and a developing unit. A unit 8, a transfer roller 13, and a cleaning unit 18 are provided. The toner is supplied to the developing unit 8 from the toner container 9. The cleaning unit 18 includes a cleaning member such as a blade, a brush, or a polishing roller, and removes and collects toner remaining on the surface of the photoreceptor 5 by the cleaning member.

  When the surface of the photoreceptor 5 is uniformly charged with a predetermined polarity and potential by the charging unit 4, the exposure unit 7 is placed on the photoreceptor 5 based on the image data of the document read by the document reader 6. An electrostatic latent image of the original image is formed.

  The developing unit 8 supplies charged toner to the surface of the photoconductor 5 and develops the electrostatic latent image on the photoconductor 5 to form a toner image. The toner image is transferred onto the paper by the transfer roller 13. The sheet on which the toner image has been transferred is conveyed to a fixing unit 14 disposed above the sheet conveyance path 11. After the toner image is transferred to the paper, the toner remaining on the surface of the photoconductor 5 is cleaned and collected by the cleaning unit 18, and the residual charge on the surface of the photoconductor 5 is removed by a static elimination device (not shown).

  The fixing unit 14 includes a fixing roller 14a having a built-in heat source and a pressure roller 14b, and pressurizes and heats the paper on which the toner image has been transferred by the fixing roller 14a and the pressure roller 14b, thereby converting the toner image on the paper. Melt and fix. The sheet on which the toner image is fixed is conveyed to the upper right in the sheet conveyance path 11 and is discharged by the discharge roller pair 20 to the in-body discharge unit 17 which is a discharge unit.

  A reverse conveyance path 16 is provided that branches from the sheet conveyance path 11 between the fixing unit 14 and the discharge roller pair 20. The reverse conveyance path 16 is used when a toner image is fixed on one side of the paper and then formed on the other side of the paper as needed. It covers the periphery of the fixing unit 14, further extends downward between the sheet conveyance path 11 and the side surface 2 a of the apparatus main body 2, and merges with the sheet conveyance path 11 near the registration roller pair 12.

  When performing double-sided printing, the paper on which the toner image is fixed on one side of the paper is discharged to the in-body paper discharge unit 17 while the branch portion between the paper conveyance path 11 and the reverse conveyance path 16 is moved to the rear of the paper. The discharge roller pair 20 is reversely rotated at the timing when the end passes. As a result, the paper is switched back, sent to the reverse conveyance path 16 with the printing surface of the paper turned upside down, and conveyed from the reverse conveyance path 16 to the registration roller pair 12 of the paper conveyance path 11 again. Thereafter, when the toner image is transferred to the other side of the sheet by the image forming unit 3, the sheet is fixed by the fixing unit 14 and discharged to the in-body sheet discharge unit 17.

  The fixing unit 14 and the reverse conveyance path 16 disposed around the fixing unit 14 are configured as shown in FIG. FIG. 2 is a plan view showing the periphery of the fixing unit 14. 2 is a plan view seen from the back side of FIG. 1, and accordingly, the side surface 2a of the apparatus main body 2 is shown on the right side of FIG. 2, and the in-body discharge section 17 is on the left side of FIG. Indicated.

  A discharge guide member 61, a discharge roller pair 20, a reverse guide member 62, a top cover 51, and a side cover 55 are disposed around the fixing unit 14.

  The discharge guide member 61 is disposed on the downstream side of the sheet conveyance path 11 with respect to the fixing unit 14 and adjacent to the fixing roller 14a. A conveyance guide surface 61 a is formed on the discharge guide member 61. The conveyance guide surface 61 a is formed in an arc shape from above the fixing roller 14 a to the discharge roller pair 20, and guides the fixed sheet from the fixing unit 14 to the discharge roller pair 20.

  The discharge roller pair 20 includes a discharge roller 20a fixed to the second support shaft 20c and disposed on the upper side, and a roller 20b disposed on the lower side of the discharge roller 20a and pressed against the discharge roller 20a. When the shaft 20 c is rotationally driven, the discharge roller 20 a rotates and the roller 20 b is driven to rotate, and the sheet is discharged to the in-body discharge unit 17.

  The reverse guide member 62 is disposed so as to cover the upper and right sides of the outer periphery of the pressure roller 14b. The reverse guide member 62 is formed with a conveyance guide surface 62a and a reverse guide surface 62b.

The conveyance guide surface 62a is disposed to face the conveyance guide surface 61a of the discharge guide member 61, and is formed to extend from the upper side of the pressure roller 14b to the branching portion 62c toward the discharge roller pair 20. Accordingly, the conveyance guide surface 62 a guides the fixed sheet from the fixing unit 14 toward the discharge roller pair 20 together with the conveyance guide surface 61 a of the discharge guide member 61.
Note that the branching portion 62 c is provided at a position that substantially intersects the paper conveyance path 11 and the reverse conveyance path 16.

  The reverse guide surface 62b faces the opposite side of the conveyance guide surface 62a and extends from the branch portion 62c to the side surface 2a side of the apparatus main body 2. The reversing guide surface 62b faces the upper surface cover 51 substantially in parallel, but the surface on the branching portion 62c side is gently inclined downward, and the surface on the side surface 2a side of the apparatus main body 2 faces downward. It is formed in an arc shape. Therefore, after the rear end of the sheet has passed through the branch portion 62c, when the discharge roller pair 20 rotates in the reverse direction, the sheet is guided substantially parallel to the upper surface cover 51 by the surface of the reverse guide surface 62b on the branch portion 62c side. The reversing guide surface 62b is guided downward in an arc shape by the surface on the side surface 2a side, and is guided substantially parallel to the side surface 2a of the apparatus main body 2 by a conveyance guide (not shown). Further, the sheet is conveyed from the reverse conveyance path 16 to the registration roller pair 12 (see FIG. 1) in the sheet conveyance path 11. Since the surface on the branching portion 62c side is gently inclined downward, the paper that has passed through the branching portion 62c from the paper conveyance path 11 is smoothly guided to the reverse conveyance path 16 without returning to the paper conveyance path 11. The

  The upper surface cover 51 is disposed so as to face the upper side of the reverse guide member 62 and a part of the discharge guide members 61, and is supported so as to be rotatable about the second support shaft 20c of the discharge roller pair 20. . The reversing guide member 62 and the fixing unit 14 are exposed from the apparatus main body 2 by the rotation operation of the upper surface cover 51 in the arrow B direction. The upper surface cover 51 includes a conveyance guide member 52 and a cover member 53.

  The conveyance guide member 52 is provided to face the reverse guide surface 62 b of the reverse guide member 62 and a part of the conveyance guide surface 61 a of the discharge guide member 61, and is fixed together with the conveyance guide surface 61 a of the discharge guide member 61. Is guided from the branch portion 62c to the discharge roller pair 20, while the reversed paper is guided along the reverse guide surface 62b along the reverse conveyance path 16 in the horizontal direction.

  The cover member 53 forms an exterior surface with respect to the upper surface of the apparatus main body 2. The document reading device 6 is disposed above the fixing unit 14, but a gap 2 b is formed between the cover member 53 and the document reading device 6. When the upper surface cover 51 is rotated around the second support shaft 20c, the cover member 53 can be opened and closed within the gap 2b.

  The side cover 55 forms an exterior surface with respect to the side surface 2 a of the apparatus main body 2, and has a conveyance guide surface 55 a that forms the reverse conveyance path 16 on the opposite side of the exterior surface. The conveyance guide surface 55 a has a surface facing the arc surface of the reversing guide surface 62 b of the reversing guide member 62 and a surface extending in parallel to the side surface 2 a of the apparatus main body 2. Further, the side cover 55 is rotatably supported below the side surface 2a of the apparatus main body 2 so that the side surface 2a of the apparatus main body 2 can be opened and closed by a rotation operation. The reversal conveyance path 16 is exposed from the apparatus main body 2 by the rotation operation of the side cover 55 in the opening direction.

  The reversing guide member 62 is supported to be swingable as shown in FIG. FIG. 3 is a perspective view showing the configuration of the reversing guide member 62.

  The reverse guide member 62 has a pair of first bearings 62e. The pair of first bearings 62e are provided at both ends in the longitudinal direction of the reversing guide member 62, and are provided so as to protrude upward from the reversing guide surface 62b on the branching portion 62c side (upstream side of the reversing conveyance path 16). . The first bearings 62e are formed in a U shape with the lower side opened, and are supported by a pair of first support shafts 2d provided in the apparatus main body 2 so as to be swingable. The first bearing 62e and the first support shaft 2d constitute a first rotating shaft that is the center of swinging of the reversing guide member 62, and the reversing guide member 62 is swingable about the first rotating shaft. The reversing guide member 62 is provided with a pair of support shafts, the apparatus main body 2 is provided with a pair of bearing holes, and the first rotating shaft is composed of the support shaft of the reversing guide member 62 and the bearing holes of the device main body 2. It may be.

  Further, the reversing guide member 62 has a pair of concave surfaces 62d which are first engaging portions. The pair of concave surfaces 62 d are provided at both ends of the reversing guide member 62 in the longitudinal direction. The concave surface 62d is recessed in an arc shape below the reversing guide surface 62b at a position away from the first bearing 62e with respect to the conveying path of the reversing conveying path 16 (a position on the downstream side of the reversing conveying path 16). (The other concave surface 62d of the pair of concave surfaces 62d is invisible in FIG. 3). The concave surface 62d can be engaged with a hook portion 52a of the upper surface cover 51, which will be described later. When the upper surface cover 51 rotates, the reversing guide member 62 is centered on the first rotation axis by the engagement of the concave surface 62d and the hook portion 52a. And can be swung.

  4 to 6 show a detailed configuration of the top cover 51 having a hook portion 52a which is a second engagement portion. 4 is a perspective view of the top cover 51 as viewed from below, FIG. 5 is a perspective view of the cover member 53 of the top cover 51 as viewed from below, and FIG. 6 illustrates the transport guide member 52 of the top cover 51. It is the perspective view seen from the lower side.

  As shown in FIG. 4, the upper surface cover 51 includes a conveyance guide member 52 and a cover member 53. A conveyance guide member 52 is attached to the inner surface of the cover member 53, and the conveyance guide member 52 is rotatably supported by the second support shaft 20 c of the discharge roller pair 20.

  As shown in FIG. 5, the cover member 53 is made of a resin having a good appearance finish and is formed in a rectangular shape with a rising portion at the outer edge. The cover member 53 has a plurality of fitting protrusions 53a formed on the inner side surface 53b opposite to the exterior surface. The plurality of fitting protrusions 53a are for attaching the conveyance guide member 52 to the cover member 53, and are arranged side by side in the longitudinal direction so as to face each other with the outer side in the width direction as a bowl shape, and can be elastically deformed in the width direction. is there.

  As shown in FIG. 6, the transport guide member 52 is made of a heat-resistant resin and is formed in a rectangular shape so as to fit on the inner side surface 53 b (see FIG. 5) of the cover member 53. Since the upper surface cover 51 is disposed in the vicinity of the fixing unit 14, the exterior surface of the upper surface cover 51 may be thermally deformed due to the heat of the fixing unit 14. However, the upper surface cover 51 is separated into the cover member 53 and the conveyance guide member 52, and the conveyance guide member 52 made of a resin having heat resistance is interposed between the cover member 53 and the fixing unit 14, thereby the cover member. 53 is not directly affected by the heat of the fixing unit 14, and the top cover 51 does not impair the appearance performance.

  The conveyance guide member 52 includes a hook portion 52a that is an upper surface engagement portion, a fitting hole 52b that engages with the fitting protrusion 53a of the cover member 53, a second bearing 52c, and a conveyance guide surface 52d.

  A plurality of fitting holes 52b are formed in the longitudinal direction so as to be engageable with the pair of fitting projections 53a of the cover member 53. When the conveyance guide member 52 faces the inner side surface 53b of the cover member 53 and is accommodated in the cover member 53, the fitting protrusion 53a of the cover member 53 is elastically deformed and engages with the fitting hole 52b of the conveyance guide member 52, thereby conveying the conveyance guide. The member 52 is attached to the cover member 53.

  The conveyance guide surface 52d is formed by arranging a plurality of fin-shaped ribs in the longitudinal direction, the conveyance guide surface 61a of the discharge guide member 61 (see FIG. 2), and the reverse guide surface 62b of the reverse guide member 62 (see FIG. 2). It is arrange | positioned facing. The conveyance guide surface 52d is disposed opposite to the conveyance guide surface 61a of the discharge guide member 61 to guide the fixed sheet, and the conveyance guide surface 52d is disposed opposite to the reverse guide surface 62b. Guide the reversed paper.

  A pair of second bearings 52 c are provided at both ends in the longitudinal direction of the conveyance guide member 52, and are provided upstream of the reverse conveyance path 16. The second bearings 52c are formed in a U shape with the lower side opened, and are rotatably supported by the second support shafts 20c (see FIG. 4) of the discharge roller pair 20, respectively. The second bearing 52c and the second support shaft 20c constitute a second rotation shaft that is the rotation center of the transport guide member 52 (upper surface cover 51), and the upper surface cover 51 is rotatable about the second rotation shaft. Become.

  A pair of hook portions 52 a are provided at both ends of the conveyance guide member 52 in the longitudinal direction, and are provided on the downstream side of the reverse conveyance path 16. The hook portion 52a is formed in a hook shape on the inner side in the longitudinal direction, and can be engaged with the concave surface 62d of the reversing guide member 62 (see FIG. 3). Specifically, the upper surface of the hook portion of the hook portion 52 a can contact the concave surface 62 d of the reversing guide member 62. When the transport guide member 52 (upper surface cover 51) rotates, the reverse guide member 62 swings in conjunction with the rotation of the transport guide member 52 due to the engagement between the hook portion 52a and the concave surface 62d.

  FIG. 7 is a diagram schematically showing a drive mechanism that swings the reversing guide member 62 in accordance with the turning operation of the upper surface cover 51.

  The drive mechanism 70 is formed on a first rotating shaft 71 composed of a first support shaft 2d and a first bearing 62e, a second rotating shaft 72 composed of a second support shaft 20c and a second bearing 52c, and a reversing guide member 62. 62 d (first engagement portion) and a hook portion 52 a (second engagement portion) provided on the upper surface cover 51.

  The first rotation shaft 71 constitutes the swing center of the reversing guide member 62, and the second rotation shaft 72 constitutes the rotation center of the upper surface cover 51.

  The hook portion 52 a of the upper surface cover 51 is engaged with the concave surface 62 d of the reversing guide member 62 on its upper surface. When the upper surface cover 51 rotates in the direction of arrow B (the opening direction of the upper surface cover 51), the hook portion 52a rotates in the direction of arrow B around the second rotation shaft 72. Due to the rotation of the hook portion 52 a, the concave surface 62 d that comes into contact with the hook portion 52 a is lifted, and the reverse guide member 62 swings around the first rotation shaft 71 in the arrow B direction.

  Here, a distance from the first rotation shaft 71 to the concave surface 62d is a first distance X1, and a distance from the second rotation shaft 72 to the hook portion 52a is a second distance X2. The first distance X1 is configured to be smaller than the second distance X2. According to this configuration, the first rotation shaft 71 is disposed on the downstream side of the reverse conveyance path 16 with respect to the second rotation shaft 72. The first distance X1 is the distance between the position of the concave surface 62d that contacts the hook portion 52a and the first rotation shaft 71.

  According to the embodiment, when the upper surface cover 51 is rotated by a predetermined angle in the direction of arrow B and the upper surface cover 51 is opened, the reversing guide member is interlocked with the rotation operation of the upper surface cover 51 in the opening direction. 62 swings in the direction of arrow B to be larger than a predetermined angle. Therefore, the fixing unit 14 (see FIG. 2) covered with the reversing guide member 62 is widely exposed from the reversing guide member 62, and it becomes easy to perform jam processing of the fixing unit 14. Further, as in the present embodiment, another member such as the document reading device 6 is disposed on the upper side of the fixing unit 14, the gap between the top cover 51 and the document reading device 6 is small, and the top cover 51 is rotated largely. It can also be applied when it cannot be opened. In this case, the image forming apparatus becomes small.

  In the above embodiment, the first distance X1 is configured to be smaller than the second distance X2, but the arrangement and configuration of the members around the fixing unit 14 such that the upper surface cover 51 can be opened at a large angle. Accordingly, the first distance X1 may be appropriately equal to or greater than the second distance X2.

  FIG. 8 is a plan view showing the periphery of the fixing unit 14 with the top cover 51 opened. When the paper is jammed between the fixing roller 14 a and the pressure roller 14 b and the paper is removed from the fixing unit 14, first, the side cover 55 is opened with respect to the apparatus main body 2. When the side cover 55 is opened, the reverse guide member 62 is exposed from the apparatus main body 2. Next, the top cover 51 is opened with respect to the apparatus main body 2. When the upper surface cover 51 is opened, that is, when the upper surface cover 51 rotates about the second support shaft 20 c, the reversing guide member 62 moves in the same direction as the upper surface cover 51 in conjunction with the rotation operation of the upper surface cover 51. It swings around the support shaft 2d. The fixing unit 14 is exposed from the reverse guide member 62 by the swinging of the reverse guide member 62. In this state, the paper jammed in the fixing unit 14 can be easily removed.

  Further, according to the above-described embodiment, the upper surface cover 51 is configured so that the side surface cover 55 side is opened by the rotation operation of the upper surface cover 51 in the opening direction, and the reverse guide member 62 is configured so that the fixing unit 14 is open. Is exposed from the apparatus main body 2 toward the side cover 55 side. Since the operation of opening and closing the side cover 55 and the opening and closing of the top cover 51 and the removal of the sheet from the fixing unit 14 are always performed from the side cover 55, it is easy to perform jam processing.

  Further, according to the embodiment, the driving mechanism 70 includes the first rotating shaft 71, the second rotating shaft 72, the concave surface 62 d formed on the reverse guide member 62, and the hook portion 52 a provided on the upper surface cover 51. The fixing unit 14 covered with the reversing guide member 62 can be exposed in conjunction with the turning operation of the upper surface cover 51.

  In the embodiment described above, the conveyance guide surface 55a of the side cover 55 forms the reverse conveyance path 16 together with the reverse guide surface 62b of the reverse guide member 62. However, the present invention is not limited thereto, and the side cover 55 is not limited thereto. Instead of the transport guide surface 55 a, the transport guide surface 52 d of the transport guide member 52 extends further to the downstream side of the reverse transport path 16, and the extended transport guide surface 52 d is the reverse guide of the reverse guide member 62. You may comprise so that the surface 62b may be opposed. In this configuration, when the jam processing of the fixing unit 14 is performed, the top cover 51 is simply opened without the side cover 55 being opened, and the reversing guide member 62 is covered in conjunction with the rotation of the top cover 51. The fixing unit 14 can be exposed.

  In the above-described embodiment, an example is shown in which the present invention is applied to the image forming apparatus 100 in which the document reading device 6 is disposed on the upper side of the fixing unit 14. Further, the present invention may be applied to an image forming apparatus such as a printer in which the upper surface cover 51 is disposed without the document reading device 6 being disposed.

  In the above embodiment, the upper surface cover 51 is configured by the cover member 53 and the conveyance guide member 52. However, the present invention is not limited thereto, and the upper surface cover 51 may be configured by one member. Good.

  In the above-described embodiment, the hook portion 52a is provided on the upper surface cover 51 and the concave surface 62d is formed on the reversing guide member 62. However, the present invention is not limited to this, and the upper surface cover 51 is provided with a concave surface. The reverse guide member 62 may have a convex portion, and the lower side of the convex portion of the reverse guide member 62 may be in contact with the concave surface of the upper surface cover 51. In this case, the turning operation of the upper surface cover 51 causes the concave surface of the upper surface cover 51 to lift the convex portion of the reversing guide member 62, and the reversing guide member 62 swings. Thus, the same effect as in the above embodiment can be obtained.

  The present invention can be used for an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine thereof. In particular, the present invention can be used for an image forming apparatus having a jamming mechanism of a fixing unit located above the apparatus. it can.

2 apparatus main body 2a side surface 2b gap 2d first support shaft (first rotation shaft)
3 Image forming unit 5 Photoconductor (image carrier)
DESCRIPTION OF SYMBOLS 11 Paper conveyance path 14 Fixing part 14a Fixing roller 14b Pressure roller 16 Reverse conveyance path 17 In-body discharge part (discharge part)
20 discharge roller pair 20a discharge roller 20b roller 20c second support shaft (second rotation shaft)
51 Upper surface cover 52 Conveying guide member 52a Hook part (second engaging part)
52b Fitting hole 52c Second bearing (second rotating shaft)
52d conveyance guide surface 53 cover member 53a fitting projection 53b inner surface 55 side cover 55a conveyance guide surface 61 discharge guide member 61a conveyance guide surface 62 reverse guide member 62a conveyance guide surface 62b reverse guide surface 62c branching portion 62d concave surface (first engagement) Part)
62e First bearing (first rotating shaft)
70 Drive Mechanism 71 First Rotating Shaft 72 Second Rotating Shaft 100 Image Forming Apparatus

Claims (6)

An image forming unit for transferring a toner image formed on the image carrier onto a recording medium;
A fixing unit that melts and fixes the toner image transferred onto the recording medium in the image forming unit;
A discharge unit for discharging the recording medium on which the toner image is fixed by the fixing unit;
A paper transport path for transporting a recording medium from the image forming section to the discharge section;
A reversing conveyance path for reversing a recording medium that is extended along the upper surface and side surface of the apparatus main body and on which the image is formed on one surface, and reconveyed to the image forming unit;
A reversing guide surface is disposed on the upper side of the apparatus body so as to be able to swing so as to cover the fixing unit, and forms a part of the sheet transport path on the transport guide surface, while facing the opposite side of the transport guide surface. A reversing guide member that forms part of the reversing conveyance path;
An upper surface cover that is rotatably supported with respect to the upper surface of the apparatus main body, and that can open and close the upper surface of the apparatus main body by a rotating operation;
An image forming system comprising: a drive mechanism that swings the reversing guide member to a position that exposes the fixing unit and a position that covers the fixing unit in conjunction with the opening and closing operation of the upper surface cover. apparatus. The drive mechanism includes: a first rotation shaft that forms a swing center of the reversing guide member; and a first engaging portion that is provided on the reversing guide member and is separated from the first rotation shaft by a first distance. A second rotation shaft that constitutes a rotation center of the upper surface cover, and a second rotation shaft that is provided on the upper surface cover and spaced from the second rotation shaft by a second distance and is engageable with the first engagement portion. 2 engaging portions,
In conjunction with the pivoting operation of the upper surface cover in the opening direction, the second engagement portion pivots about the second rotation axis, whereby the first engagement portion is lifted, and the inversion guide The image forming apparatus according to claim 1, wherein the member swings about the first rotation axis.   The first engaging portion is formed in a concave shape having a lower surface as an engaging surface, and the second engaging portion is formed in a hook shape having an upper surface capable of contacting the engaging surface of the first engaging portion. The image forming apparatus according to claim 2, wherein the image forming apparatus is an image forming apparatus.   The image forming apparatus according to claim 2, wherein the first distance is configured to be smaller than the second distance. A side cover that is supported rotatably with respect to the side surface of the apparatus main body, that allows the side surface of the apparatus main body to be opened and closed by a rotation operation, and that exposes the reverse conveyance path from the apparatus main body by rotation in an opening direction;
The top cover is configured such that the side cover side is opened by the pivoting operation of the top cover in the opening direction, and the reversing guide member is configured such that the fixing unit faces the side cover side. The image forming apparatus according to claim 1, wherein the image forming apparatus is configured to be exposed from the main body.   The said upper surface cover has a cover member which forms the upper surface of an apparatus main body, and the conveyance guide member arrange | positioned facing the said inversion guide surface, The Claim 1 characterized by the above-mentioned. Image forming apparatus.