JP2010210911A - Fixing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device that reduces area of contact between paper and a rib guide and prevents dew on a rib guide from adhering to the paper. <P>SOLUTION: The fixing device includes a fixing section 8 for heating and melting a toner image to fix it to the paper, and a guiding section 9 (second guiding member 9B) for guiding the paper P from the fixing section 8 to a paper eject section 104. The second guide member 9B has at the paper contact side leading end a plurality of projections 92a arranged in parallel along a paper guide direction (a). The paper contact side face of the second guide member 9B is formed of convex and concave faces 92. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fixing device and an image forming apparatus.

  A conventional fixing device includes a fixing unit that heats and melts a toner image and fixes the toner image on a sheet, and a guide having a sheet guide unit that guides the sheet from the fixing unit toward a sheet discharge unit (patent) Reference 1).

  In such a fixing device, when the sheet passes through the fixing unit, the toner image transferred onto the sheet is heated and melted and fixed. Thereafter, the sheet is conveyed to the paper discharge unit while being guided along the sheet guide unit of the guide.

JP-A-6-118828

  SUMMARY OF THE INVENTION An object of the present invention is to provide a fixing device and an image forming apparatus that can reduce the contact area of a sheet that contacts a rib guide and reduce the adhesion of condensation on the sheet to the sheet.

  In order to achieve the above object, the present invention provides the fixing devices (1) to (8) and the image forming device (9).

[1] A fixing unit that heats and melts a toner image and fixes the toner image on a sheet, and a guide member that guides the sheet from the fixing unit toward the sheet discharge unit. The guide member includes a plurality of guide members along the sheet guide direction. A fixing device in which a sheet contact side surface is formed as a concavo-convex surface by providing a plurality of juxtaposed convex portions at a front end portion on a sheet contact side.

[2] In the guide member, the upstream surface in the paper transport direction of the two surfaces forming the convex portions on the uneven surface is more gently inclined with respect to the paper guide direction than the downstream surface in the paper transport direction The fixing device according to [1], wherein the fixing device is formed by a surface.

[3] The fixing device according to [2], wherein the guide member is formed by a curved surface with an upstream surface in a paper conveyance direction protruding toward a paper contact side.

[4] The fixing device according to [1], wherein the guide member is formed with a flat surface at a tip end surface of each protrusion on the uneven surface.

[5] The fixing device according to [1], wherein the guide member has a escaping portion for escaping dew condensation generated on a surface thereof from a downstream side in a sheet conveying direction toward an upstream side of the guide portion.

[6] The fixing device according to [5], wherein a surface of the guide member is subjected to water repellent treatment.

[7] The guide member includes a plurality of rib guides each having the concavo-convex surface, and the convex portion is disposed between the two rib guides adjacent to each other in the plurality of rib guides so as to be shifted from each other along the paper guide direction. The fixing device according to [1].

[8] The fixing device according to [7], wherein the plurality of rib guides are arranged in parallel along a direction intersecting a sheet guide direction.

[9] An image forming apparatus comprising the fixing device according to any one of [1] to [8].

  According to the first and ninth aspects of the present invention, it is possible to reduce the contact area of the sheet that contacts the guide member, and to reduce the condensation on the sheet caused by the guide member.

  According to the second aspect of the present invention, the guide is better than the case where the surface on the downstream side in the paper transport direction is formed with a gentler inclined surface with respect to the paper guide direction than the surface on the upstream side in the paper transport direction. Sex is obtained.

  According to the third aspect of the invention, the paper is smoothly guided along the upstream surface in the paper conveyance direction.

  According to the fourth aspect of the present invention, wear of each convex portion on the concave and convex surface of the guide member is reduced.

  According to the fifth aspect of the present invention, the flow of condensation from the escape portion to the tip portion of the guide member is prevented.

  According to the sixth aspect of the present invention, good fluidity of dew condensation from the distal end portion of the guide member to the escape portion can be obtained.

  According to the seventh aspect of the invention, when the paper is guided by the guide member, the leading edge of the paper with respect to the concave portion of the uneven surface is suppressed.

  According to the eighth aspect of the present invention, when the paper is guided by the guide member, the drop of the front end of the paper with respect to the concave portion of the uneven surface is further effectively suppressed.

FIG. 1 is a cross-sectional view for explaining an image forming apparatus to which a fixing device according to a first embodiment of the present invention is applied. FIG. 2 is a side view for explaining the entire fixing device according to the first embodiment of the present invention. FIG. 3 is a front view showing an arrangement state of the rib guides in the fixing device according to the first embodiment of the present invention. FIG. 4 is a side view illustrating the rib guide of the fixing device according to the first embodiment of the present invention. FIGS. 5A and 5B are side views for explaining the modifications (1) and (2) of the rib guide in the fixing device according to the first embodiment of the present invention. FIG. 5A shows a modification (1), and FIG. 5B shows a modification (2). FIG. 6 is a side view for explaining the rib guide of the fixing device according to the second embodiment of the present invention. FIG. 7 is a side view for explaining a modified example of the rib guide in the fixing device according to the second embodiment of the present invention. FIG. 8 is a front view for explaining the arrangement state of the rib guides in the fixing device according to the third embodiment of the present invention. FIG. 9 is a front view for explaining a modified example of the rib guide in the fixing device according to the third embodiment of the present invention.

[First embodiment]
First, an image forming apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 shows the entire image forming apparatus.

[Overall configuration of image forming apparatus]
In FIG. 1, an image forming apparatus denoted by reference numeral 100 includes, for example, a tandem image forming apparatus, and includes an apparatus housing 101, an image forming unit 102, a paper supply unit 103, a paper discharge unit 104, and a paper discharge reversing unit. 105 is built in the apparatus housing 101 and is applied to, for example, a copying machine.

(Configuration of device casing 101)
The apparatus housing 101 has a discharge tray 106 at an upper portion thereof, and an accommodation space 107 for accommodating an image forming unit 102, a paper supply unit 103, a paper discharge unit 104, a paper discharge reversing unit 105, and the like is provided therein. . In the apparatus housing 101, the conveyance path 108 from the paper supply unit 103 to the image forming unit 102, the paper discharge path 109 from the image forming unit 102 to the paper discharge unit 104, and the image from the branching unit 109 a of the paper discharge path 109 are displayed. A reversing path 110 leading to the forming unit 102 is provided, and an opening / closing lever 111 for opening and closing the paper discharge path 109 is disposed.

(Configuration of image forming unit 102)
The image forming unit 102 includes a first image forming unit 2K that forms a black (K) toner image, a second image forming unit 2Y that forms a yellow (Y) toner image, and a magenta (M) toner. A third image forming unit 2M that forms an image; a fourth image forming unit 2C that forms a cyan (C) toner image; and image forming units 2K, 2Y, 2M, and 2C that are arranged at the primary transfer position. Transfer devices 3K, 3C, 3M, and 3Y that transfer the black, yellow, magenta, and cyan toner images respectively formed on the intermediate transfer belt 30, and a drive roll 4 that rotates and drives the intermediate transfer belt 30 in the arrow R direction. , Supporting rolls 5A to 5C that rotatably support the intermediate transfer belt 30 with a predetermined tension, a cleaning unit 6 that cleans the surface of the intermediate transfer belt 30, and an intermediate transfer A secondary transfer roll 7 for secondary transfer of the toner image transferred to the belt 30 to the paper P; a fixing device 22 having a fixing unit 8 for fixing the toner image transferred to the paper P by heating and melting; and image formation The units 2K, 2Y, 2M, and 2C have an exposure device 31 that exposes the photosensitive drum 20, and are disposed above the paper supply unit 103 and accommodated in the accommodation space 107.

  The developing device 23 receives toner from the toner cartridge 52 via the toner supply device 50. The exposure device 31 exposes the photosensitive drum 20 through a mirror 311 with a laser beam 310 modulated based on the image data of each color (K, Y, M, C) to form an electrostatic latent image. Details of the fixing device 22 will be described later.

  The image forming units 2K, 2Y, 2M, and 2C are configured to be attachable to the apparatus housing 101. Each of the image forming units 2K, 2Y, 2M, and 2C charges the photosensitive drum 20 having the photosensitive layer on the surface and the photosensitive drum 20 before exposure. Charging device 21, developing device 23 that develops (visualizes) each color toner corresponding to the electrostatic latent image formed on the photosensitive drum 20, static eliminating device 25 that neutralizes the photosensitive drum 20, and primary transfer And a drum cleaning unit 26 for removing residual toner remaining on the subsequent photosensitive drum 20.

(Configuration of paper supply unit 103)
The paper supply unit 103 includes a paper feed tray 127 and a paper feed unit 128 that sends the paper P stacked in the paper feed tray 127 to the image forming unit 102. The paper feed unit 103 is disposed below the image forming unit 102. In addition, the sheet is accommodated on the sheet feeding tray insertion / extraction side of the accommodation space 107.

  The paper feed tray 127 is housed in the housing space 107 of the apparatus housing 101 so as to be insertable / removable, and is configured so that the paper P can be stacked therein.

  The paper delivery unit 128 includes a pickup roll 129 for delivering the topmost paper among the papers P stacked in the paper feed tray 127, and a feed roll 130a for separating the paper P delivered by the pickup roll 129 one by one. The sheet feeding mechanism 130 including a retard roll 130 b is provided and is disposed on the sheet delivery side of the sheet feeding tray 127.

  The pickup roll 129 is rotatably supported by a free end of a swing plate (not shown) that swings about the roll axis of the feed roll 130a. The swing plate is always urged toward the paper feed tray 127 by a spring (not shown). As a result, the pickup roll 129 is pressed against the uppermost sheet P with a predetermined nip pressure.

  The paper handling mechanism 130 is disposed at a position where the feed roll 130a and the retard roll 130b can rotate in contact with each other. A pair of registration rolls 132 and 132 for positioning and transporting the paper P to the image forming unit 102 are disposed on the downstream side of the paper handling mechanism 130.

(Configuration of paper discharge unit 104)
The paper discharge unit 104 includes a paper discharge unit 131, is disposed above the image forming unit 102, and is stored on the paper discharge (discharge tray 106) side of the storage space 107.

  The paper discharge unit 131 includes a unit main body (not shown) and a pair of discharge rolls (discharge / reversing rolls) 133 and 134, and is disposed in the vicinity of the paper discharge reversing unit 105.

  The discharge rolls 133 and 134 are rotatably supported by a unit main body (not shown). The discharge rolls 133 and 134 are configured to discharge the paper P that has undergone image formation by the image forming unit 102 to the outside by rotation to one side. Further, the discharge rollers 133 and 134 form an image from the paper discharge unit 104 through the paper discharge reversing unit 105 in a state where the front and back surfaces of the paper P that has undergone image formation by the image forming unit 102 are reversed by rotation to the other side. It is configured to be conveyed to the unit 102.

  One discharge roll 133 is formed by a drive roll for forward and reverse rotation, and the other discharge roll 134 is formed by a driven roll. Switching of the discharge roll 133 is performed by a switching mechanism (not shown).

(Configuration of the paper discharge reversing unit 105)
The paper discharge reversing unit 105 includes a plurality of transport rolls 32 that constitute a paper discharge reversing device together with the discharge rolls 133 and 134, is disposed in the vicinity of the paper discharge unit 104, and is accommodated in the accommodation space 107.

  The plurality of transport rolls 32 are arranged along the reverse path 110 on the downstream side of the paper discharge reverse unit 105. The paper P is transported in the paper transport direction.

(Configuration of Fixing Device 22)
Next, the fixing device 22 according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 2 shows the entire fixing device. FIG. 3 shows an arrangement state of rib guides in the fixing device. FIG. 4 shows a rib guide of the fixing device.

  As shown in FIG. 2, the fixing device 22 includes a fixing unit 8 and a guide unit 9, and is interposed between the paper discharge unit 131 and the secondary transfer roll 7 (shown in FIG. 1). Is arranged.

  The fixing unit 8 includes a heating roll 8 </ b> A and a pressure roll 8 </ b> B, and is configured to heat and fuse the toner image transferred onto the paper P by the secondary transfer roll 7.

  The heating roll 8A includes a heater 80 and is formed by a driving roll that rotates in the direction of the arrow. The pressure roll 8B has an elastic layer such as rubber on the outer peripheral surface, and is formed by a driven roll that rotates in the direction of the arrow by the rotation of the heating roll 8B.

  As shown in FIG. 2, the guide unit 9 includes a first guide member 9 </ b> A that guides the paper P from the secondary transfer roll 7 (shown in FIG. 1) toward the fixing unit 8, and the discharge unit from the fixing unit 8. The second guide member 9 </ b> B and the third guide member 9 </ b> C that guide the sheet P toward the sheet 104 are configured to guide the sheet P along the sheet conveyance path 108.

  The first guide member 9A is arranged on the upstream side of the fixing unit 8, and the second guide member 9B and the third guide member 9C are arranged on the downstream side of the fixing unit 8, respectively. Among these, the second guide member 9B includes a base 90 and a plurality of rib guides 91, 91,..., And is disposed at a position facing the third guide member 9C via the paper discharge path 109.

  A plurality of rib guides 91, 91,... Hold an open / close lever 111 that opens and closes the paper discharge path 109 and the reverse path 110. The open / close lever 111 is normally configured to close the paper discharge path 109 by its own weight, as indicated by a solid line in FIG. Further, as shown by a two-dot chain line in FIG. 2, the opening / closing lever 111 opens the paper discharge path 109 by the rotation of the paper P when the paper P is conveyed from the paper discharge path 109 to the paper discharge unit 104. It is configured. An upper surface 91 a of the rib guide 91 serves as a guide for the paper discharge path 109.

  As shown in FIG. 3, the plurality of rib guides 91, 91,... Are arranged in parallel in a direction orthogonal to the paper guide direction a, and are entirely formed of, for example, PET (polyethylene terephthalate) resin. The plurality of rib guides 91, 91,... Are provided with a plurality of convex portions 92 a, 92 a,. 92,... This reduces the contact area of the paper P that contacts the plurality of rib guides 91, 91,..., And reduces the condensation on the paper P that occurs in the plurality of rib guides 91, 91,.

  As shown in FIG. 4, the plurality of rib guides 91, 91,... Are guided by a surface 92c on the upstream side of the guide among the two surfaces 92c, 92b forming the convex portions 92a of the uneven surfaces 92, 92,. It is formed with an inclined surface that is gentler relative to the paper guide direction than the downstream surface 92b. As a result, better guideability can be obtained as compared to the case where the surface 92b on the downstream side of the guide is formed with an inclined surface that is gentler than the surface 92c on the upstream side of the guide.

[Operation of image forming apparatus]
Next, the operation of the image forming apparatus 100 described in this embodiment will be described with reference to FIGS.

  In the initial state, as shown by the solid line in FIG. 1, the open / close lever 111 is disposed at a position where the paper discharge path 109 is closed.

  First, the paper P stacked in the paper feed tray 127 is separated one by one by the paper delivery unit 128 and delivered to the stopped registration rolls 132 and 132.

  Next, the leading edge of the sheet P is abutted against the registration rolls 132, 132, the skew feeding of the sheet is corrected, the position of the leading edge of the sheet is adjusted, and the sheet P is put on standby.

  When writing is possible in the image forming unit 102, the registration rollers 132 and 132 are rotated to feed the paper P to the transfer devices 3K, 3C, 3M, and 3Y, and the toner images are transferred by the transfer devices 3K, 3C, 3M, and 3Y. After the toner image is transferred, the toner image is fixed by the fixing unit 8 and then conveyed from the fixing unit 8 to the discharge rollers 133 and 134. In this case, since the paper P is guided along the guide portion 9 (rib guide 91), the contact area of the paper P that contacts the rib guide 91 is reduced, and the condensation on the paper P caused by the rib guide 91 is reduced. Can do.

  Here, when an image is formed on the first paper surface or the second paper surface of the paper P, the paper P presses the open / close lever 111 and moves from the position indicated by the solid line in FIG. 1 to the position indicated by the two-dot chain line in FIG. Rotate. For this reason, the paper discharge path 109 is opened. As a result, the paper P after image formation passes through the branching portion 109 a of the paper discharge path 109 by the forward rotation of the discharge rollers 133 and 134 and is discharged from the paper discharge portion 104 to the paper discharge tray 106.

  On the other hand, when forming an image on the first paper surface and the second paper surface of the paper P, a part of the paper P after the image formation on the first paper surface starts from one end of the paper P and the discharge rollers 133 and 134 The paper is conveyed to the paper discharge unit 104 by forward rotation. The paper P conveyed to the paper discharge unit 104 is conveyed from the paper discharge unit 104 to the paper discharge reversing unit 105 by reverse rotation of the discharge rollers 133 and 134 with the rear end as the head, and further from the paper discharge reversing unit 105 to the reverse path. It is conveyed to the registration rolls 132 and 132 via 110.

  Next, the leading edge of the sheet P is abutted against the registration rolls 132, 132, the skew feeding of the sheet is corrected, the position of the leading edge of the sheet is adjusted, and the sheet P is put on standby.

  When writing is possible in the image forming unit 102, the registration rollers 132 and 132 are rotated to feed the paper P to the transfer devices 3K, 3C, 3M, and 3Y, and the toner images are transferred by the transfer devices 3K, 3C, 3M, and 3Y. Then, the toner image is fixed by the fixing unit 8 and then conveyed from the fixing unit 8 to the discharge rollers 133 and 134. In this case, since the paper P is guided along the guide portion 9 (rib guide 91), the contact area of the paper P that contacts the rib guide 91 is reduced, and the condensation on the paper P caused by the rib guide 91 is reduced. Can do.

  Thereafter, the paper P presses the opening / closing lever 111 to rotate from the position indicated by the solid line in FIG. 1 to the position indicated by the two-dot chain line in FIG. For this reason, the paper discharge path 109 is opened. As a result, the paper P after the image formation on the second paper surface passes through the branch portion 109a of the paper discharge path 109 by the forward rotation of the discharge rollers 133 and 134, and is discharged from the paper discharge portion 104 to the paper discharge tray 106.

  In the present embodiment, the case has been described in which the surfaces 92c and 92b of the convex portions 92a are the rib guides 91 having the concave and convex surfaces 92 formed by inclined surfaces, but FIGS. 5 (a) and 5 (b). It is good also as the rib guide 91B as shown. FIG. 5A shows a modification (1) of the rib guide, and FIG. 5B shows a modification (2) of the rib guide.

  The rib guide 91 </ b> B shown in FIG. 5A is formed by a flat surface at the tip of the convex portion 92 a on the concave and convex surface 92. Thereby, the abrasion of the convex part 92a in the uneven surface 92 is reduced.

  The rib guide 91B shown in FIG. 5B is formed by a curved surface in which the guide upstream surface 92c of the concavo-convex surface 92 protrudes toward the paper contact side. Thereby, the paper P is smoothly guided along the surface 92c on the upstream side of the guide.

[Second Embodiment]
FIG. 6 shows a rib guide of a fixing device according to the second embodiment of the present invention. In FIG. 6, the same or equivalent members as in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 6, the rib guide 91 is characterized in that it has a release portion that releases condensation generated on the surface thereof from the guide downstream side toward the guide upstream side.

  For this reason, the escape portion is composed of a concave groove 91 b that opens on the surface of the rib guide 91, and is disposed between the distal end portion (paper contact side end portion) and the base end portion of the rib guide 91. Thereby, the flow of the dew condensation from the base end part in the rib guide 91 to the front-end | tip part in the groove 91b is blocked | prevented.

  Further, the surface of the rib guide 91 is subjected to water repellent treatment across the distal end portion and the proximal end portion. Thereby, the fluidity | liquidity with favorable dew condensation from the front-end | tip part of the rib guide 91 to the concave groove 91b is obtained.

  The water-repellent treatment is performed by spraying, for example, a mixture of PTFE (polytetrafluoroethylene) resin and a binder (polyamideimide) or a mixture of PFA (tetrafluoroethylene) resin and a binder onto the surface of the rib guide 91 and then 250 ° C. or less. It is performed by firing at a temperature of In this case, the rib guide 91 is desirably made of a material such as a liquid crystal polymer or PPS (polyphenylene sulfide) having a heat resistant temperature of 300 ° C. or higher.

  In the present embodiment, a case has been described in which the escape portion is formed of a concave groove opened on the surface of the rib guide 91, but the escape portion as shown in FIG. 7 may be used. FIG. 7 shows a modification of the relief portion.

  The relief portion shown in FIG. 7 includes a thick portion 91d, a thin portion 91c (thickness of the thick portion 91d is greater than the thickness of the thin portion 91c), and thicknesses set to two different sizes. By forming a rib guide 91 having a stepped portion 91e interposed between the thick portion 91d and the thin portion 91c, the rib guide 91 is provided between the distal end portion and the proximal end portion.

[Third embodiment]
FIG. 8 shows a rib guide arrangement state in the fixing device according to the third embodiment of the present invention. 8, the same or equivalent members as those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 8, the second guide member 9 </ b> B has two types of rib guides 91, 91 each having concave and convex surfaces 92, 92 in which the phases of the convex portions 92 a, 92 a are different from each other (four in this embodiment). The point is that they are arranged alternately.

  For this reason, the plurality of rib guides 91, 91,... Are composed of two symmetrical (four in this embodiment) rib guide aggregates having uneven surfaces 92, 92,. It is arranged in parallel in the direction to do.

  The convex portions 92a, 92a,... Of the concave and convex surfaces 92, 92,... Are arranged at positions shifted from each other along the paper guide direction a between two adjacent rib guides among the plurality of rib guides 91, 91,. . As a result, when the sheet P is guided by the plurality of rib guides 91, 91,..., The depression of the leading end of the sheet with respect to the recesses 92c, 92c,.

  In the present embodiment, a case has been described in which a plurality of rib guides 91, 91,... Are arranged in a direction orthogonal to the paper guide direction a, but the present invention is not limited to this and is shown in FIG. A plurality of rib guides 91, 91,.

  As shown in FIG. 9, the plurality of rib guides 91, 91,... Are composed of two sets (four each) of rib guide assemblies having uneven surfaces 92, 92,. Are arranged so as to extend from the upstream side of the guide toward the downstream side of the guide.

  Although the image forming apparatus of the present invention has been described based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

(1) In the above-described embodiment, the concave and convex surfaces 92, 92,... In the rib guides 91, 91,... Are provided with a plurality of convex portions 92a, 92a,. However, the present invention is not limited to this, and it is also possible to form a concavo-convex surface by providing a plurality of concave portions at the end of the paper contact side.

(2) In the above embodiment, the case where the present invention is applied to a copying machine has been described. However, the present invention is not limited to this, and may be applied to a printer or a facsimile. You may apply to the compound machine which combines two.

(3) Although the case where the image forming apparatus 100 is a color image forming apparatus using a plurality of photosensitive drums 20 has been described in the above embodiment, the present invention is not limited to this, and a single photosensitive drum is used. It may be a monochrome image forming apparatus using

2K: First image forming unit, 2Y: Second image forming unit, 2M: Third image forming unit, 2C: Fourth image forming unit, 3K, 3C, 3M, 3Y: Transfer device, 4: Drive Rolls, 5A to 5C: support rolls, 6: cleaning unit, 7 ... secondary transfer roll, 8 ... fixing unit, 8A ... heating roll, 8B ... pressure roll, 9 ... guide unit, 9A ... first guide member, 9B: Second guide member, 9C: Third guide member, paper feed tray, 10: Conveying roll, 20 ... Photosensitive drum, 21 ... Charging device, 22 ... Fixing device, 23 ... Developing device, 24 ... Transfer device , 25 ... neutralization device, 26 ... drum cleaning unit, 30 ... intermediate transfer belt, 31 ... exposure device, 32 ... transport roll, 50 ... toner supply device, 52 ... toner cartridge, 80 ... heater, 90 ... base, 91 ... rib guide 91a ... Inner surface, 91b ... concave groove, 91c ... thin portion, 91d ... thick portion, 91e ... stepped portion, 92 ... uneven surface, 92a ... convex portion, 92b ... guide downstream side surface, 92c ... guide upstream side surface, 100 DESCRIPTION OF SYMBOLS ... Image forming apparatus 101 ... Apparatus housing | casing 102 ... Image forming part 103 ... Paper supply part 104 ... Paper discharge part 105 ... Paper discharge reversing part 106 ... Discharge tray 107 ... Storage space 108 ... Paper conveyance 109, paper discharge path, 110, reverse path, 111, open / close lever, 127, paper feed tray, 128, paper feed unit, 129, pick-up roll, 130, paper roll mechanism, 130a, feed roll, 130b, retard roll 131 ... sheet discharge unit, 132 ... registration roll, 133,134 ... discharge roll, 132 ... 310 ... laser beam, 311 ... mirror, a ... paper conveyance direction, ... paper

Claims (9)

A fixing unit that heats and melts the toner image and fixes the toner image on the paper;
A guide member for guiding the paper from the fixing unit toward the paper discharge unit,
The guide member is a fixing device in which a plurality of convex portions arranged in parallel along the paper guide direction are provided at the front end portion on the paper contact side, and the paper contact side surface is formed as an uneven surface.   The guide member is formed such that the upstream surface in the paper transport direction of the two surfaces forming the convex portions on the concave and convex surface is a slant surface that is gentler relative to the paper guide direction than the downstream surface in the paper transport direction. The fixing device according to claim 1.   The fixing device according to claim 2, wherein the guide member is formed with a curved surface with an upstream surface in a sheet conveyance direction protruding toward a sheet contact side.   The fixing device according to claim 1, wherein the guide member is formed with a flat surface at a tip end surface of each convex portion on the uneven surface.   2. The fixing device according to claim 1, wherein the guide member has a release portion that releases condensation generated on a surface of the guide member from the downstream side in the sheet conveyance direction toward the upstream side of the guide portion.   The fixing device according to claim 5, wherein the guide member has a water repellent treatment on a surface thereof.   The guide member includes a plurality of rib guides each having the concavo-convex surface, and the convex portion is disposed at a position where the convex portions are displaced from each other along a paper guide direction between two adjacent rib guides among the plurality of rib guides. Item 4. The fixing device according to Item 1.   The fixing device according to claim 7, wherein the plurality of rib guides are arranged in parallel along a direction intersecting a sheet guide direction. An image forming apparatus comprising the fixing device according to claim 1.

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