JP2008020729A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus achieving the reduction of copying cost by decreasing the number of sheets of wasted paper even when jamming occurs in the midst of printing processing. <P>SOLUTION: The image forming apparatus 1A includes: an image forming part 14 having a photoreceptor drum 3 and transferring a toner image to the paper P; a fixing unit 6 fixing the toner image transferred to the paper P on the paper P; and a paper conveying device 7 ejecting the paper P on which a developer image has been fixed to a paper output tray 9, and outputs an image in compliance with a printing requirement. The apparatus 1A includes a paper conveyance path 7a for conveying a recording medium on which the developer image has been fixed toward the image forming part again as the paper conveying device 7, and equipped with a paper collecting device 90 for making normal paper P accumulated in the paper conveyance path 7a retreat from the paper conveyance path 7a and housing it when the paper P going through a printing processing stage is jammed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus that is applied to an electrophotographic copying machine, multifunction machine, printer, facsimile, and the like and outputs an image in response to a print request.

  In recent years, the function of an image forming apparatus is generally a double-sided printing function, and the printing processing speed has been increased. For example, in the past, development of an apparatus having a light printing processing speed of 100 sheets / min or more is in progress.

  Corresponding to the double-sided printing function of the image forming apparatus, as the paper discharge method, face-up discharge that discharges the printing surface upward during single-sided printing, face-down discharge that discharges the printing surface downward, and discharge page of double-sided printing A method of discharging the first surface for aligning the order downward is known (see Patent Document 1).

In such a paper discharge method, the face-down discharge and the discharge at the time of double-sided printing are performed by increasing the speed after passing through the fixing mechanism in consideration of the print processing speed (process speed) of the image forming apparatus. In this way, the printing process efficiency is improved.
Japanese Patent Laid-Open No. 04-55256

  However, in such an apparatus, since a plurality of sheets are arranged in the sheet conveyance path and continuously processed, the sheet conveyance speed can be increased. In this case, the number of sheets staying in the sheet conveyance path when a sheet jam occurs is extremely increased as compared with the prior art.

  In this state, when the printing process is resumed after removing all the sheets in the sheet conveyance path and performing initialization of the apparatus in the same manner as in the prior art, the printing process is delayed and more sheets are wasted, The problem arises that the copy cost increases.

  The present invention has been made in view of the above-described conventional problems, and provides an image forming apparatus that reduces the number of sheets to be discarded even if a JAM occurs during a printing process, thereby reducing the copy cost. The purpose is to do.

The configuration of the image forming apparatus according to the present invention for solving the above-described problems is as follows.
The image forming apparatus according to claim 1, further comprising an electrostatic latent image carrier on which a developer image is formed by a developer, and an image on which the developer image on the surface of the electrostatic latent image carrier is transferred to a recording medium. Printing is provided with a forming unit, a fixing unit that fixes the developer image transferred onto the recording medium to the recording medium, and a recording medium conveying unit that discharges the recording medium after the developer image fixing process to a discharge tray. An image forming apparatus that outputs an image in response to a request, wherein the recording medium conveying unit includes a recording medium conveying path for conveying the recording medium after the developer image fixing process again toward the image forming unit, A recording medium recovery unit is provided for retracting and storing a normal recording medium staying in the recording medium conveyance path when a paper jam occurs in the recording medium during a printing process in the image forming apparatus. It is characterized by that .

  In the present invention, the print request includes, for example, a copier mode, a printer mode, a FAX mode, and the like that can be output by the image forming apparatus, and further output modes required by the user, that is, double-sided printing, single-sided printing. The output mode is included.

  In addition to the configuration described in claim 1, the image forming apparatus described in claim 2 is reversed as a recording medium conveyance path, a switchback conveyance path for reversing the recording medium after the developer image fixing process. A recording medium reversing conveyance path for conveying the recording medium from the switchback conveying path toward a registration roller disposed upstream of the image forming unit in the sheet conveying direction, and the recording medium collecting section is connected to the recording medium reversing conveyance path It is provided in the middle of this.

  According to a third aspect of the present invention, in addition to the configuration described in the first or second aspect, the recording medium recovered by the recording medium recovery unit is at least a recording medium after passing through the fixing unit. It is characterized by.

  According to a fourth aspect of the present invention, in addition to the configuration described in the first or second aspect, the recording medium collected by the recording medium collecting unit is printed on one side in a print processing mode in which double-sided printing is performed. After the processing is completed, the recording medium is being transported for double-sided printing processing.

  According to a fifth aspect of the present invention, in addition to the configuration described in any one of the first to fourth aspects, the image forming apparatus includes the recording medium collecting unit, and the conveyed recording medium is upstream in the recording medium conveying direction. It is characterized in that it is stored from the side and discharged from the downstream side in the recording medium conveyance direction.

  In addition to the configuration described in any one of claims 1 to 5, the image forming apparatus described in claim 6 is configured to stack the recording medium collection unit on the upper side in the order of conveyance. The recording medium is discharged in order from the upper recording medium of the stacked recording medium.

  That is, according to the present invention, when JAM occurs in the paper transport path, the paper is discharged from the recording medium closest to the print processing unit.

  According to a seventh aspect of the present invention, in addition to the configuration described in any one of the first to sixth aspects, the image forming apparatus supplies a recording medium supplied again as the recording medium recovery unit. The recording medium supply structure includes at least a pick-up roller for discharging the recording medium, a separator roller for separating the recording medium one by one, and a separator member.

  According to an eighth aspect of the present invention, in addition to the configuration described in the seventh aspect, when the recording medium is recovered, the recording medium supply structure is retracted to a range that does not interfere with the recovered recording medium. It is characterized by doing so.

  In addition to the configuration described in claim 7 or 8, the image forming apparatus described in claim 9 is configured such that the recording medium supply structure has a rear end of the recording medium with respect to a conveyance direction when the recording medium recovery unit recovers the recording medium. It is characterized by being arranged on the part side.

  According to a tenth aspect of the present invention, in addition to the configuration according to any one of the first to ninth aspects, the image forming apparatus includes an alignment member that aligns the stored recording medium as the recording medium recovery unit. The alignment member is characterized in that the length of the recording medium storage area of the recording medium recovery unit can be changed according to the length of the recording medium to be stored.

  In addition to the structure described in claim 10, the image forming apparatus described in claim 11 is configured such that the alignment member is disposed on the leading end side of the recording medium with respect to the transport direction when the recording medium recovery unit collects the recording medium. It is characterized by this.

  In addition to the structure described in claim 11, the image forming apparatus described in claim 12 aligns the recording medium by pressing the one end of the recording medium accommodated through the elastic member. It is a feature that has been made.

  That is, according to the present invention, the position of the recording medium to be aligned by being pushed by the alignment member is changed according to the elastic force of the elastic member.

  According to the first aspect of the present invention, the image has the electrostatic latent image carrier on which the developer image is formed by the developer, and transfers the developer image on the surface of the electrostatic latent image carrier to the recording medium. Printing is provided with a forming unit, a fixing unit that fixes the developer image transferred onto the recording medium to the recording medium, and a recording medium conveying unit that discharges the recording medium after the developer image fixing process to a discharge tray. An image forming apparatus that outputs an image in response to a request, wherein the recording medium conveying unit includes a recording medium conveying path for conveying the recording medium after the developer image fixing process again toward the image forming unit, A recording medium recovery unit is provided for retracting and storing a normal recording medium staying in the recording medium conveyance path when a paper jam occurs in the recording medium during a printing process in the image forming apparatus. The device is in the process of printing When JAM of the recording medium is detected, a recording medium not related to JAM is temporarily stored in the recording medium collecting unit in the recording medium conveyance path, and after the JAM paper is removed, the recording medium is removed from the recording medium collecting unit. Since it is possible to return to the forward-dimensional recording medium conveyance path and contribute to continuous printing, it is possible to realize an image forming apparatus capable of reducing wasteful disposal paper and reducing copy cost. .

  Moreover, according to invention of Claims 2-12, in addition to the said common effect obtained by the invention of Claim 1, the following effect can be acquired.

  That is, according to the second aspect of the present invention, the recording medium conveyance path includes a switchback conveyance path that reverses the recording medium after the developer image fixing process, and the reversed recording medium from the switchback conveyance path. A recording medium reversing conveyance path that conveys toward a registration roller disposed upstream of the image forming unit in the sheet conveying direction, and the recording medium recovery unit is provided in the middle of the recording medium reversing conveyance path, The recording medium staying in the switchback conveying path or the recording medium reversing conveying path can be stored in the recording medium collecting unit.

  According to the invention described in claim 3, in addition to the effect obtained by the invention described in claim 1 or 2, the recording medium recovered by the recording medium recovery unit is recorded after passing through at least the fixing means. By using the medium, the recording medium on which the image transferred onto the recording medium is fixed is collected, so that the recording medium can be used again without being contaminated with toner.

  According to the invention described in claim 4, in addition to the effect obtained by the invention described in claim 1 or 2, the recording medium collected in the recording medium collecting part is subjected to a printing process mode in which double-sided printing is performed. In this case, the double-sided printing process is performed without wasting the recording medium on which the single-sided printing process is completed when the apparatus is restarted by using the recording medium in the middle of conveyance for the double-sided printing process after the single-sided printing process is completed. be able to.

  According to the invention described in claim 5, in addition to the effect obtained by the invention described in any one of claims 1 to 4, the recording medium collecting unit is used as the recording medium conveyed. By storing from the upstream side in the transport direction and discharging from the downstream side in the recording medium transport direction, the direction of the recording medium can be returned to the normal transport state when the apparatus is restarted.

  According to the invention described in claim 6, in addition to the effect obtained by the invention described in any one of claims 1 to 5, the recording medium recovery unit is arranged so that the recording medium is moved upward in the order of conveyance. In this case, the processing order of a plurality of collected recording media can be returned to the normal processing order.

  According to the invention described in claim 7, in addition to the effect obtained by the invention according to any one of claims 1 to 6, the recovered recording medium is supplied again as the recording medium recovery unit. A recording medium supply structure that includes at least a pickup roller for discharging the recording medium, a separator roller that separates the recording medium one by one, and a separator member. Each sheet can be reliably returned to the recording medium conveyance path.

  According to the invention described in claim 8, in addition to the effect obtained by the invention described in claim 7, the recording medium supply structure does not interfere with the collected recording medium when the recording medium is collected. By retracting to the range, the collected recording medium can be reliably stored in the recording medium collecting unit.

  According to the ninth aspect of the present invention, in addition to the effect obtained by the seventh or eighth aspect of the invention, the recording medium supply structure is recorded in the recording direction with respect to the transport direction when the recording medium recovery unit recovers the recording medium. By arranging the recording medium on the rear end side of the medium, the recovered recording medium can be returned from the rear end when returning to the recording medium conveyance path, so that the conveyance process can be performed reliably.

  According to the invention described in claim 10, in addition to the effect obtained by the invention according to any one of claims 1 to 9, the recording medium to be stored is aligned as the recording medium recovery unit. An alignment member, and the alignment member is configured such that the length of the recording medium storage area of the recording medium recovery unit can be changed according to the length of the storage medium to be stored. Even if they are different, the recording media can be easily arranged.

  According to the invention described in claim 11, in addition to the effect of the invention described in claim 10, the alignment member is disposed on the leading end side of the recording medium with respect to the transport direction when the recording medium recovery unit recovers the recording medium. By arranging, the leading end position of the recording medium can be easily adjusted.

  According to the invention described in claim 12, in addition to the effect obtained in the invention described in claim 11, the alignment member is pressed by pressing one end of the recording medium accommodated via the elastic member. By aligning the recording media, it is possible to align the recording media easily collected with a simple configuration.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 and 2 show an example of an embodiment of the present invention. FIG. 1 is an explanatory diagram showing the overall configuration of the image forming apparatus according to the embodiment of the present invention. FIG. 2 shows the main body of the image forming apparatus. FIG.

  The image forming apparatus 1A according to the present embodiment includes a photosensitive drum (electrostatic latent image carrier) 3 on which a developer image is formed by a developer, and a toner image (developer image) on the surface of the photosensitive drum 3. Is formed on a sheet-like paper (recording medium) P, a fixing unit (fixing means) 6 for fixing the toner image transferred onto the paper P to the paper P, and after the developer image fixing process. A paper transport device (recording medium transport means) 7 for discharging the paper P to the paper discharge tray 9 is provided, and image data read into the scanner unit 22 and the like and image data transmitted from the outside are transferred to the paper P by electrophotography. An image forming apparatus that outputs and forms a monochrome (single color) image as a configuration of the sheet conveying apparatus 7. The sheet conveying path (for conveying the sheet P after the developer image fixing process again toward the image forming unit 14) (Recording medium transport path) a paper collecting device (recording device) for retracting and storing normal paper P staying in the paper transport path 7a when the paper P in the print processing process causes JAM (paper jam). Medium recovery unit) 90 is provided.

  First, the overall configuration of the image forming apparatus 1A according to the present embodiment will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the image forming apparatus 1 </ b> A mainly includes an exposure unit 1, a developing device 2, a photosensitive drum 3, a charger 4, a charge eliminating device 41, a cleaner unit 5, and a fixing unit (fixing unit). 6, an apparatus main body 1A1 including a sheet conveying device (recording medium discharging means) 7, a sheet conveying path (recording medium conveying path) 7a, a sheet feeding tray 8, a sheet discharge tray 9, a transfer mechanism 10, and the like, and automatic document processing It is comprised by apparatus 1A2.

  A document placing table 21 made of transparent glass on which a document is placed is provided on the upper surface of the apparatus main body 1A1. Above the document placing table 21, the automatic document processing device 1A2 is swingably opened upward. On the other hand, a scanner unit 22 serving as a document reading unit that reads image information of a document is disposed below the document placement table 21.

  Below the scanner unit 22, the exposure unit 1, the developing device 2, the photosensitive drum 3, the charger 4, the charge removal device 41, the cleaner unit 5, the fixing unit 6, the paper transport device 7, the paper transport path 7 a, and the paper discharge A tray 9 and a transfer mechanism 10 are disposed, and a paper feed tray 8 in which the paper P is stored is disposed below the tray 9 and the transfer mechanism 10.

  The exposure unit 1 performs exposure by irradiating the surface of the photosensitive drum 3 uniformly charged by the charger 4 with laser light according to image data (image information for printing) output from an image processing unit (not shown). Thus, it has a function of writing and forming an electrostatic latent image corresponding to image data on the surface of the photosensitive drum 3.

  The exposure unit 1 is disposed immediately below the scanner unit 22 and above the photosensitive drum 3, and employs laser scanning units (LSU) 13 a and 13 b including a laser irradiation unit 11 and a reflection mirror 12. In the present embodiment, in order to perform high-speed printing processing, a technique of using a plurality of laser beams to reduce the irradiation timing is adopted, and a two-beam technique is adopted.

  In this embodiment, the laser scanning units (LSU) 13a and 13b are used for the exposure unit 1, but a light emitting element arranged in an array, for example, an EL or LED writing head may be used. .

  As shown in FIG. 2, the photosensitive drum 3 has a cylindrical shape, is disposed below the exposure unit 1, and is rotated in a predetermined direction (the direction of arrow A in the figure) by a driving unit and a control unit (not shown). Is controlled. Along the outer peripheral surface of the photosensitive drum 3, the sheet peeling claw 31, the cleaner unit 5, the charger 4 as an electric field generating unit, and the development head toward the downstream side in the rotational direction of the photosensitive drum with reference to the position after completion of image transfer. The device 2 and the static eliminator 41 are arranged in this order.

  The sheet peeling claw 31 is disposed so as to be able to contact and separate from the outer peripheral surface of the photosensitive drum 3 by a solenoid 32. The sheet peeling claw 31 is stuck to the surface of the photosensitive drum 3 when the unfixed toner image on the photosensitive drum 3 is transferred to the sheet P in a state of being in contact with the outer peripheral surface of the photosensitive drum 3. The sheet P is peeled off.

  Note that a driving motor or the like may be employed as the driving means for the sheet peeling claw 31 instead of the solenoid 32, and other driving means may be selected.

  The developing device 2 visualizes the electrostatic latent image formed on the photosensitive drum 3 with black toner, and is downstream of the charger 4 in the rotating direction of the photosensitive drum (the direction of arrow A in the figure). It is arranged substantially horizontally (right side in the figure) on the side of the photosensitive drum 3. A registration roller 15 is disposed below the developing unit 2 on the upstream side in the recording medium conveyance direction.

  The registration roller 15 aligns the front end of the paper P supplied from the paper feed tray 8 and the toner image on the photoconductive drum 3 and conveys it between the photoconductive drum 3 and the transfer belt 103 (not shown). The operation is controlled by the drive means and the control means.

The charger 4 is a charging means for uniformly charging the surface of the photosensitive drum 3 to a predetermined potential, and is disposed above the photosensitive drum 3 and in the vicinity of the outer peripheral surface thereof.
In this embodiment, the charger type charger 4 is used. However, a contact type roller type or a brush type may be used.

  The static eliminator 41 is a pre-transfer static eliminator for reducing the surface potential of the photosensitive drum 3 in order to facilitate the transfer of the toner image formed on the surface of the photosensitive drum 3 to the paper P. It is arranged downstream of the developing device 2 in the drum rotating direction and close to the outer peripheral surface below the photosensitive drum 3.

  In the present embodiment, the static eliminator 41 is configured using a static elimination electrode. However, a static elimination lamp may be used in place of the static elimination electrode, or other static elimination may be used.

  The cleaner unit 5 removes and collects toner remaining on the surface of the photosensitive drum 3 after development and image transfer. The cleaner unit 5 is located at a position substantially opposite to the developing device 2 with the photosensitive drum 3 interposed therebetween. The drum 3 is disposed substantially horizontally (left side in the drawing) on the side.

As described above, the electrostatic image visualized on the photosensitive drum 3 is applied from the transfer mechanism 10 onto the paper P on which the electric field having the opposite polarity to the charge of the electrostatic image is conveyed. Transferred onto P.
For example, when the electrostatic image has a charge of (−) polarity, the applied polarity of the transfer mechanism 10 is (+) polarity.

  As shown in FIG. 2, the transfer mechanism 10 is bridged by a driving roller 101, a driven roller 102, and other rollers, and has a predetermined resistance value (in this embodiment, a range of 1 × 10 9 to 1 × 10 13 Ω · cm). A transfer belt unit having a transfer belt 103 is disposed, and is arranged below the photosensitive drum 3 so that the surface of the transfer belt 103 is in contact with a part of the outer peripheral surface of the photosensitive drum 3. . The transfer belt 103 conveys the paper P while pressing it against the photosensitive drum 3.

  An elastic conductive roller 105 capable of applying a transfer electric field with a conductivity different from that of the driving roller 101 and the driven roller 102 is disposed at the contact portion 104 between the photosensitive drum 3 and the transfer belt 103.

  The elastic conductive roller 105 is made of a soft material such as elastic rubber or foamable resin. Since the elastic conductive roller 105 has elasticity, the photosensitive drum 3 and the transfer belt 103 are not in line contact but in surface contact having a predetermined width (referred to as a transfer nip), so that the sheet P to be conveyed is conveyed. The transfer efficiency can be improved.

  Further, on the downstream side of the transfer area of the transfer belt 103 in the sheet conveyance direction, a discharge roller 106 for discharging the electric field applied to the sheet P to be transferred in the transfer area and smoothly transferring to the next process is transferred. It is arranged on the back side of the belt 103.

  In addition, the transfer mechanism 10 is provided with a cleaning unit 107 that removes dirt from the residual toner on the transfer belt 103 and a plurality of charge removal mechanisms 108 that perform charge removal on the transfer belt 103. As a technique for performing static elimination used in the static elimination mechanism 108, there is a technique of grounding through an apparatus, or a technique of positively applying a polarity opposite to the polarity of the transfer electric field.

  The electrostatic image (unfixed toner) transferred onto the paper P by the transfer mechanism 10 is conveyed to the fixing unit 6 and is pressurized and heated to melt the unfixed toner and be fixed on the paper P. .

  As shown in FIG. 2, the fixing unit 6 includes a heating roller 6a and a pressure roller 6b. The heating roller 6a is rotated while the sheet P is sandwiched between the heating roller 6a and the pressure roller 6b. By passing between 6a and the pressure roller 6b, the toner image transferred onto the paper P is melted and fixed.

  A conveyance roller 16 that conveys the paper P is provided downstream of the fixing unit 6 in the paper conveyance direction.

  The heating roller 6a is provided with a sheet peeling claw 611, a roller surface temperature detecting member (thermistor) 612, and a roller surface cleaning member 613 on the outer peripheral portion, and the heating roller surface is set to a predetermined temperature (fixing set temperature) on the inner peripheral portion. : Approximately 160 to 200 ° C.).

  The pressure roller 6b is provided with a pressure member 621 that allows the pressure roller 6b to come into pressure contact with the heating roller 6a at a predetermined pressure amount at both ends of the roller. Similarly to the outer periphery of the roller 6a, a sheet peeling claw 622 and a roller surface cleaning member 623 are arranged.

  As shown in FIG. 2, the fixing unit 6 is configured to remove unfixed toner on the conveyed paper P at a pressure contact portion (called a so-called fixing nip portion) 600 between the heating roller 6a and the pressure roller 6b. The unfixed toner is fixed on the paper P by the application of the heat applied by the heat roller 6a to melt and the throwing action on the paper P by the pressure contact force between the heating roller 6a and the pressure roller 6b.

  The paper feed tray 8 is used for accumulating a plurality of sheets (paper sheets) on which image information is output (printed). The exposure unit 1, the developing device 2, the photosensitive drum 3, the charger 4, and the charge eliminating device. The image forming unit 14 is configured below the image forming unit 14 including the apparatus 41, the cleaner unit 5, the fixing unit 6, and the like. A paper pickup roller 8a and transport rollers 8b and 8c are disposed on the upper side of the paper discharge side of the paper feed tray 8 (see FIG. 3).

  The paper P loaded in the paper feed tray 8 is picked up one by one from the uppermost layer by the paper pick-up roller 8a, and the paper P is transported downstream in the paper transport direction by the transport rollers 8b and 8c (for convenience, paper The flow side (cassette side) of P is upstream and the discharge side is downstream.) The sheet is conveyed to a registration roller (also referred to as “idle roller”) 15 side on the sheet conveyance path 7a.

  In the image forming apparatus 1A according to the present embodiment, in order to perform high-speed printing processing, a plurality of paper supply units capable of storing 500 to 1500 sheets of standard size sheets P in each tray are provided below the image forming unit 14. A paper tray 8 is disposed, and on the other hand, a large-capacity paper feed cassette 81 capable of storing a large amount of a plurality of paper types is disposed on the side of the apparatus, and an irregular type is mainly disposed above the large-capacity paper feed cassette 81. A manual feed tray 82 corresponding to size printing or the like is provided.

  The paper discharge tray 9 is disposed on the side of the apparatus opposite to the manual feed tray 82. Further, instead of the paper discharge tray 9, a post-processing device (device for performing stapling, punching, etc.) of paper discharge, a multi-stage paper discharge tray, and the like can be arranged as options.

  The paper transport path 7a is configured between the above-described photosensitive drum 3 and the paper feed tray 8, and transports the paper P supplied from the paper feed tray 8 to the transfer mechanism 10 one by one. The sheet on which the toner image is transferred from the photosensitive drum 3 is conveyed to the fixing unit 6, and after the unfixed toner image is fixed on the sheet in the fixing unit 6, the sheet is formed according to the designated discharge processing mode. A sheet is conveyed by a path or a branch claw.

  In the image forming apparatus A1 according to the present embodiment, a single-sided printing mode and a double-sided printing mode are set as preset discharge processing modes. In the single-sided printing mode, face-up discharge for discharging the print surface upward and face-down discharge for discharging the print surface downward are set as discharge processing.

Here, the sheet conveying device 7 will be described in detail with reference to the drawings.
FIG. 3 is an explanatory diagram showing a configuration of a sheet conveyance path constituting the sheet conveyance apparatus of the image forming apparatus according to the present embodiment, and FIG. 4 is a branched sheet conveyance path constituting the sheet conveyance path and a branch for communicating them. It is a partial detail drawing which shows the structure of a nail | claw.

  As shown in FIG. 3, the sheet conveying device 7 includes a sheet conveying path (recording medium conveying path) 7 a through which the sheet P passes from the image forming unit 14 to the fixing unit 6 and the paper discharge tray 9. Yes. As shown in FIG. 4, the sheet conveyance path 7a mainly passes through the fixing unit 6 via the first sheet conveyance path 7a1 from the sheet feed tray 8 to the registration roller 15 and from the registration roller 15 via the transfer mechanism 10. The second paper transport path 7a2 to the downstream transport roller 16 and the third paper transport path (first roller) to the paper discharge roller (transport roller) 17 for discharging the paper from the transport roller 16 to the paper discharge tray 9. Recording medium conveyance path) 7a3, the fourth paper conveyance path 7a4 for reversing the paper P from the conveyance roller 16, and the reverse conveyance roller 18 that communicates with the fourth paper conveyance path 7a4 and conveys the paper P to the registration roller 15 again. The fifth paper transport path 7a5, the sixth paper transport path 7a6 that reverses from the paper discharge roller 17 and transports the paper P, and the seventh paper transport that communicates with the sixth paper transport path and avoids the fifth paper transport path 7a5. Road 7a7 and No. Communicates with the sheet conveying path 7a7 is constituted by the eighth sheet conveying path 7a8 leading the switchback roller 19.

  In particular, the fourth paper transport path 7a4 is configured as a switchback transport path for reversing the paper P after the toner image fixing process, and the fifth paper transport path 7a5 is configured to transfer the reversed paper P from the fourth paper transport path 7a4. It is configured as a recording medium reversal conveyance path that conveys toward the registration roller 15 disposed upstream of the image forming unit 14 in the sheet conveyance direction.

  In the fifth paper transport path 7a5, a paper collection device 90 is provided in the middle of the transport path between the fourth paper transport path 7a4 and the registration rollers 15.

  A plurality of sheets P are arranged in the sheet transport path 7a according to the processing mode. In this embodiment, as shown in FIG. 3, eight sheets P of (1) to (8) (indicated by the circled numbers in the figure) are arranged in the sheet transport path 7a. The number of sheets P allowed in the sheet conveyance path can be changed in any way depending on the configuration of the sheet conveyance path.

  In the paper transport path 7a, a plurality of branching claws that change the transport path of the paper P by selecting the paper transport path according to the selected processing mode are provided at the branch points of the paper transport path. .

  As shown in FIG. 4, in the vicinity of the downstream side of the transport roller 16, a branch claw 20a that communicates with the third paper transport path 7a3 or the fourth paper transport path 7a4 is provided so as to be able to swing and displace. The branch claw 20a is operated by a solenoid (not shown).

  On the downstream side of the fourth paper transport path 7a4, a branch claw 20b that connects the fourth paper transport path 7a4 and the fifth paper transport path 7a5 or the fifth paper transport path 7a5 and the sixth paper transport path 7a6 swings. Displaceable. The branch claw 20b is operated by a spring member (not shown) and the elastic force of the paper P.

  On the downstream side of the sixth paper conveyance path 7a6, a branch claw 20c communicating with the fifth paper conveyance path 7a5 or the seventh paper conveyance path 7a7 is provided so as to be able to swing and displace. The branch claw 20c is operated by a solenoid (not shown).

  On the downstream side of the seventh paper transport path 7a7, a branch claw 20d that connects the seventh paper transport path 7a7 and the eighth paper transport path 7a8 or the fifth paper transport path 7a5 and the eighth paper transport path 7a8 is rocked. It is provided so that it can be displaced dynamically. The branch claw 20d is operated by a solenoid (not shown).

  On the upstream side of the fifth paper transport path 7a5, a branch claw 20e is provided for smoothly connecting the fourth paper transport path 7a4 and the eighth paper transport path 7a8 and the fifth paper transport path 7a5.

  According to the paper conveyance path 7a configured as described above, the branch claws 20a to 20d are operated according to the requested processing mode, and the paper conveyance path of the paper P corresponding to the processing mode can be selected.

  Here, a sheet conveying process corresponding to the processing mode of the image forming apparatus 1A will be described with reference to the drawings.

First, as shown in FIG. 3, the paper P that matches the print request is selected from the plurality of paper feed trays 8 and is transported to the registration rollers 15 by the transport rollers in the paper transport path 7a.
The paper P that has reached the registration roller 15 and has stopped once is conveyed to the transfer mechanism 10 by the rotation of the registration roller again at the timing when the leading edge of the paper P and the image information on the photosensitive drum 3 coincide with each other. After an unfixed toner image (image information) is transferred from the photosensitive drum 3 to the top, the toner image is fixed on the paper P by the fixing unit 6 and is discharged to the paper discharge tray 9.

  In the conveyance path in the sheet conveyance path 7a, the sheet discharge tray from the fixing unit 6 onward is processed by the processing mode (copier mode, printer mode, FAX mode) of the image forming apparatus 1A and the printing processing method (single-sided printing, duplex printing). The transport method up to 9 is different.

  Usually, in the copier mode, since the user performs an operation in the vicinity of the image forming apparatus 1A, a method called “face-up discharge” in which the printing surface is discharged with its upper side being used is often used.

  On the other hand, in each mode such as printer, FAX, etc., a so-called “face-down discharge” method is used in which the user is not in the vicinity of the image forming apparatus 1 </ b> A so that the page order of the discharged paper P is aligned.

  Accordingly, in the image forming apparatus 1A, the sheet P meeting the above purpose is discharged through the plurality of transport paths and the plurality of branch claws until the sheet P that has passed through the fixing unit 6 is discharged to the sheet discharge tray 9. Is supposed to do.

  Next, a characteristic sheet collecting apparatus 90 according to the present embodiment will be described with reference to the drawings. FIG. 5 is an explanatory diagram showing the configuration of the paper collecting device that constitutes the paper conveying device of the image forming apparatus according to the present embodiment.

  As shown in FIG. 5, the paper collection device 90 mainly includes a paper storage unit 91 that stores the recovered paper P, and a paper supply structure (recording medium supply structure) 92 that supplies the recovered paper P again. And an alignment portion (alignment member) 93 for aligning the stored paper P.

  The paper storage unit 91 is configured by a box body having an open upper shape that has a rectangular shape corresponding to the paper size, and a spring member for pushing up one end side of the tray unit 91a on which the paper P is stacked and the tray unit 91a. 91b.

  In the tray portion 91a, one end P1 side (the front side in the paper entering direction) of the collected paper P is lowered in the drawing, and the other end P2 side (the rear end side in the paper entering direction) of the paper P is in the drawing than the one end side. It is urged | biased upwards by the spring material 91b so that it may arrange | position upwards.

  The paper supply structure 92 includes a pickup roller 92a for transporting the paper P stored in the tray portion 91a again into the paper transport path 7a, a paper roller 92b and a paper member 92c for separating the paper P one by one, and a fifth member. A recovery paper transport path 92d that transports the recovered paper P in communication with the paper transport path 7a5 to the paper storage section 91 is provided, and the other end of the paper P above the paper storage section 91 and in the transport direction during paper recovery It is arranged on the P2 side.

  A branching claw 92e for switching the transport direction of the paper P passing through the fifth paper transport path 7a5 is provided near the branch between the fifth paper transport path 7a5 and the collected paper transport path 92d.

  Further, when the paper P is collected by the paper collecting device 90, the paper supply structure 92 is located at a position where the pickup roller 92a, the suction roller 92b, and the suction member 92c do not interfere with the collected paper P (two-dot chain line in the figure). It is designed to evacuate.

  The aligning unit 93 is disposed on the one end P1 side of the paper P with respect to the transport direction when collecting the paper in the paper storage unit 91, and stores the paper P according to the length of the paper P stored in the paper storage unit 91. The length of the paper storage area of the storage unit 91 is configured to be changeable. That is, the aligning section 93 aligns the paper P by pressing and moving the one end P1 side of the paper P stored by the spring member (elastic member) 93b with the push plate 93a.

  The paper P collected by the paper collecting device 90 is the paper P staying in the paper transport path 7 a after passing through the fixing unit (fixing means) 6. For example, in the printing process mode in which the duplex printing process is performed, the sheet P is transported into the sheet transport path 7a for the duplex printing process after the single-sided printing process is completed.

  The paper collecting device 90 stores the transported paper P from the upstream side in the paper transport direction and discharges it from the downstream side in the paper transport direction. That is, the sheets P are stacked on the upper side in the transported order, and are discharged in order from the upper sheet P of the stacked sheets P.

Next, regarding the paper discharge processing of the image forming apparatus 1A, face-up discharge and face-down discharge in single-sided printing and paper conveyance in double-sided printing will be described with reference to the drawings.
FIG. 6 is an explanatory diagram showing a sheet conveyance state by face-up discharge during single-side printing in the sheet conveyance path of the image forming apparatus according to the present embodiment, and FIG. 7 is a sheet by face-down discharge during single-side printing in the sheet conveyance path. FIG. 8 is an explanatory diagram showing a paper conveyance state during duplex printing in the paper conveyance path.

(Face-up discharge with single-sided printing)
As shown in FIG. 6, the face-up discharge in the image forming apparatus 1A is performed through the third paper transport path 7a3 in the paper transport path 7a (first recording medium transport path).

  In the image forming apparatus 1A, when face-up discharge is performed by single-sided printing of the paper P, the branching claw 20a is provided with a claw position switching unit (not shown) immediately before the paper P that has passed through the fixing unit 6 passes through the conveyance roller 16. The third paper transport path 7a3 is opened by a solenoid or the like, and the fourth paper transport path 7a4 is shielded.

  The leading end of the transported paper P is navigated to the branch claw 20a, passes through the third paper transport path 7a3, and is discharged to the paper discharge tray 9 via the paper discharge roller 17 (arrow B).

(Face-down discharge with single-sided printing)
As shown in FIG. 7, the face-down discharge in the image forming apparatus 1A is performed through the fourth paper transport path 7a4, the fifth paper transport path 7a5, and the sixth paper transport path 7a6 in the paper transport path 7a (the second paper transport path 7a). Recording medium transport path).

  In the image forming apparatus 1A, when face-down discharge is performed by single-sided printing of the paper P, the branching claw 20a has a claw position switching unit (not shown) immediately before the paper P that has passed the fixing unit 6 passes the transport roller 16. The fourth paper transport path 7a4 is opened by a solenoid or the like, and the third paper transport path 7a3 is shielded.

  Further, the branching claw 20c opens the fifth paper conveyance path 7a5 and shields the seventh paper conveyance path 7a7 by a claw position switching means (not shown).

  The transported paper P is navigated to the branch claw 20a by the leading end of the paper P and passes through the fourth paper transport path 7a4, and the branch claw 20b is moved by the waist (material strength) of the front end of the paper P and the transport force. Then, after the fifth paper transport path 7a5 is opened, it is navigated to the branch claw 20c and guided to the fifth paper transport path 7a5 (arrow C1).

When the trailing edge of the paper P reaches the position of the branching claw 20e, the conveyance of the paper P is temporarily stopped.
The branch claw 20c opens the sixth paper conveyance path 7a6 and shields the seventh paper conveyance path 7a7 by a claw position switching means (not shown).

  At this time, the branching claw 20b is naturally displaced by an elastic member (spring or the like) disposed on a branching claw holding shaft (not shown) so as to shield the fourth paper conveyance path 7a4.

  Thereafter, the reverse conveyance roller 18 rotates in the reverse direction to re-convey the paper P, and the conveyed paper P passes through the sixth paper conveyance path 7a6 from the rear end side where it stays at the position of the branching claw 20e. (Arrow C2), the paper is discharged to the paper discharge tray 9 via the paper discharge roller 17.

(Paper transport using double-sided printing)
As shown in FIG. 8, the sheet conveyance during duplex printing in the image forming apparatus 1A is the fourth sheet conveyance path 7a4, the fifth sheet conveyance path 7a5, the seventh sheet conveyance path 7a7, and the eighth sheet conveyance in the sheet conveyance path 7a. This is performed through the path 7a8 (third recording medium conveyance path).

  When double-sided printing is performed in the image forming apparatus 1A, the first claw printing (front surface printing) of the paper P is finished, and immediately before the paper P that has passed the fixing unit 6 passes the transport roller 16, the branch claw 20a is The claw position switching means (not shown) (solenoid or the like) opens the fourth paper conveyance path 7a4 and shields the third paper conveyance path 7a3.

  Further, the branching claw 20c opens the seventh paper conveyance path 7a7 and shields the fifth paper conveyance path 7a5 by a claw position switching means (not shown). Further, the branch claw 20d opens the eighth paper conveyance path 7a8 by a claw position switching means (not shown).

  The sheet P to be conveyed is navigated by the branch claw 20a at the leading end thereof, passes through the fourth sheet conveyance path 7a4, and the branch claw 20b is moved by the waist (material strength) and the conveyance force at the front end of the sheet P. After the movement, it is navigated to the branch claw 20c and guided to the seventh paper transport path 7a7 and the eighth paper transport path 7a8 (arrow D1).

  When the trailing edge of the sheet P reaches the eighth sheet conveyance path 7a8, the conveyance of the sheet P is temporarily stopped (completion of the first surface switchback). Thereafter, when the branching claw 20d shields the seventh paper conveyance path 7a7 by a claw position switching means (not shown) and the conveyance path to the branching claw 20e is opened, the switchback roller 19 rotates in the reverse direction so Transport is performed.

  The transported paper P passes through the fifth paper transport path 7a5 (arrow D2) from the rear end side where it stays at the position of the eighth paper transport path 7a8 through the branch claws 20d and 20e, and further the reverse transport roller 18. Thus, the sheet is conveyed to the registration roller 15 disposed immediately before the printing process (transfer process in the transfer mechanism).

  Thereafter, the second side printing (back side printing) of the paper P is completed, and the paper P that has passed through the fixing unit 6 is subjected to the same processing as described above (single-sided printing and face-up discharge), and the paper discharge tray 9 To be discharged.

Next, a control system of the image forming apparatus 1A according to the present embodiment will be described with reference to the drawings.
FIG. 9 is a block diagram showing the configuration of the electric control unit of the image forming apparatus according to the present embodiment.
As shown in FIG. 9, the image forming apparatus 1 </ b> A according to the present embodiment performs image reading processing, image processing, image forming processing, paper P conveyance processing, paper discharge processing, and the like in a ROM (Read Only Memory) 55. A central processing unit (CPU) 54 executes processing using temporary storage means such as a RAM (Random access Memory) 56 according to a program stored in advance.
Note that storage means such as an HDD (hard disk drive) can be used in place of the ROM 55 and the RAM 56.

  In the image forming apparatus 1A, document image information (document image data) read by the scanner unit 22 or document image information transmitted from each terminal device connected to a communication network (not shown) is transmitted via the communication processing unit 58. Are input to the image processing unit 57.

  The image processing unit 57 processes the document image information stored in the storage unit such as the RAM 56 into a print image suitable for printing (image formation on paper) by the above program.

The image information for printing is input to the image forming unit 14.
The image forming unit 14, the paper transport unit 59, the fixing unit 6, and the paper discharge processing unit (recording medium discharge unit) 60 are linked to each drive control unit 62.

The paper transport unit 59 detects and controls various types of paper in the paper transport path 7a and the like.
The sheet conveyed by the sheet conveying unit 59 is subjected to a printing process (image information printing process in the image forming unit 14), and then a fixing process (fixing unit 6) for the printed sheet. The paper is discharged to the paper discharge tray 9.
Note that detection signals from a pre-registration detection switch 596, a fixing detection switch (not shown), a paper discharge detection switch, and the like are input to the paper transport unit 59.

  The pre-registration detection switch 596 is a switch that detects whether or not a sheet has reached the registration roller 15. The fixing detection switch is a switch that detects whether or not a sheet has reached the fixing unit 6. The paper discharge detection switch is a switch that detects whether or not the paper is discharged.

The image forming apparatus 1 </ b> A is provided with an operating condition setting unit 77.
The operation condition setting unit 77 is configured to perform image formation or conveyance conditions of the image forming apparatus 1A according to an image formation request set by the user using the operation switches 76 or an image formation condition such as the type of recording medium (paper). The operation conditions are set.

  The image forming apparatus 1 </ b> A is a driving actuator such as a reading unit (scanner unit 22), a sheet conveying unit 59, an image forming unit 14, a fixing unit 6, and a paper discharge processing unit 60 according to the set operating conditions. The operation of the drive unit in a certain document reading drive unit 64, paper transport drive unit 66, print processing drive unit 68, fixing drive unit 70, paper discharge drive unit 72, and paper collection unit, that is, the CPU 54 based on the program stored in the ROM 55 An operation synchronized according to the command is performed under the control of the drive control unit 62.

The document reading drive unit 64 is a drive actuator for the scanner unit 22.
The paper transport drive unit 66 is a motor for driving the paper transport unit 59, specifically, the paper pickup roller 8a and the registration roller 15 on the paper transport path 7a.
The print processing drive unit 68 is a drive motor for the photosensitive drum 3.
The fixing driving unit 70 is a driving motor for the heating roller 6 a and the pressure roller 6 b of the fixing unit 6.

The paper discharge drive unit 72 is a drive motor such as a paper discharge roller 17.
The drive motors of these drive units can be appropriately configured through a power transmission mechanism using the same or different motors as drive sources.

  In the paper collecting device 90, an actuator for attaching and detaching the pickup roller, a driving motor for driving the pickup roller 92a and the suction roller 92b, and an actuator for retracting the suction roller 92b and the suction member 92c from the paper transport path.

  In the present embodiment, the operation of each driving motor and actuator in the paper collecting apparatus 90 is performed in conjunction with the operation of the driving unit of each unit by a signal output when JAM occurs on the conveyed paper P or the like. It is supposed to be.

  Further, the image forming apparatus 1A includes, as an optional configuration 74, a post-processing device (staples, punches, a multi-stage discharge tray, a shifter, etc.), an automatic document reading device (automatic document processing device 1A2, etc.), a large-capacity paper feed cassette. 81, etc. can be arranged, and the optional configuration 74 has the control unit 74a in each optional configuration 74 separately from the control unit of the image forming apparatus 1A, and adjusts the timing with the communication processing unit 58. Is configured to synchronize.

  The recording medium detection unit 78 detects that the leading edge of the paper reaches the fixing unit 6 or the carry-out unit.

  Specifically, the recording medium detecting unit 78 includes a conveyance time measuring unit 79a that measures the conveyance time of the sheet after the sheet is sent out from the registration roller 15 that introduces the sheet at the entrance of the sheet conveyance path 7a, and the registration roller. 15 includes a conveyance timing detection unit 79b that detects the conveyance timing of the sheet in the sheet conveyance path 7a based on the distance from the fixing unit 6 to be controlled and the discharge roller 17 and the conveyance speed of the sheet.

  In the present embodiment, the recording medium detection unit 78 is based on the conveyance timing of the recording medium detected by the conveyance timing detection unit 79b when the sheet reaches (enters) the fixing unit 6 and the discharge roller 17 respectively. I try to detect it.

  The paper discharge processing unit 60 performs transport of the paper P by the transport roller 16, the paper discharge roller 17, the reverse transport roller 18, and the switchback roller 19 and various types of detection and control. Is provided with a paper conveyance speed control function 601 for controlling the paper conveyance speed.

  The paper transport speed control function 601 controls the rotational speeds of the transport roller 16, the paper discharge roller 17, and the reverse transport roller 18 based on the transport speed of the paper P corresponding to a plurality of preset discharge processing modes, and performs printing. This is a function for selectively controlling the conveyance speed of the paper P in response to a request, and is executed by a central processing unit (CPU) 54 using temporary storage means such as a RAM 56 in accordance with a program stored in the ROM 55 in advance. .

  In addition, the control by the paper discharge processing unit based on the paper transport speed control function 601 controls the operation of the transport roller 16, the paper discharge roller 17, the reverse transport roller 18, the switchback roller 19 and the like in response to a print request, and prints. Operation control of each branching claw that communicates and shields each conveyance path of the sheet conveyance path 7a corresponding to the discharge processing according to the request is performed.

Next, the collecting operation of the paper P by the paper collecting device 90 in this embodiment will be described.
First, when JAM (paper jam) of the paper P occurs during the continuous printing process, when collecting the paper P in which the JAM staying in the paper transport path 7a is not generated, the fifth paper transport path 7a5 and the recovery are performed. The branching claw 92e provided near the branch with the paper transport path 92d is operated to switch the paper transport direction so that the paper P passing through the fifth paper transport path 7a5 is introduced into the recovered paper transport path 92d.

  Then, the paper P staying in the fourth paper transport path 7a4 and the fifth paper transport path 7a5 is transported, and the paper is stored through the collected paper transport path 92d in order from the paper P downstream in the transport direction in the paper transport path. Collected in the unit 91. At this time, the pickup roller 92a, the roller roller 92b, and the roller member 92c are retracted to positions that do not interfere with the collected paper P.

The paper P collected in the paper storage unit 91 is stored by aligning the end of the paper P by the alignment unit 93 and aligning the paper ends.
The paper collecting operation as described above is performed before the apparatus is restored.

  On the other hand, when the paper P collected in the paper storage unit 91 is to be reused, the pickup roller 92a, the suction roller 92b is driven by driving a driving motor or actuator (not shown) that displaces the pickup roller 92a, the suction roller 92b, and the suction member 92c. In addition, the sheet member 92c is disposed at a predetermined position where the sheet can be conveyed.

  Then, the pickup roller 92a is driven to take out and convey the sheets P collected in the sheet storage unit 91 one by one, and again pass through the collected sheet conveyance path 92d to again enter the fourth sheet conveyance path 7a4 and the fifth sheet conveyance path 7a5. Returned to

  When the double-sided printing process is subsequently executed after the apparatus is restored, the paper P returned to a predetermined position in the paper conveyance path is conveyed toward the registration roller 15 and the double-sided printing process is continued.

  As described above, according to the present embodiment, even when JAM occurs on the paper P during the printing process and the apparatus stops in the middle of the processing process, the paper recovery device 90 performs the single-sided printing in the double-sided printing process. The paper P that has completed the process can be collected, and the double-sided printing process can be continued using the collected paper P again. Accordingly, since the paper P staying in the paper transport path is not discarded as in the prior art, it is possible to reduce the copy cost and to efficiently output an image without wasting the printing process.

  In the present embodiment, the paper collecting device 90 is provided in the space above the paper transport path 7a and below the transfer mechanism 10, and is configured compactly without expanding the device. Therefore, the image forming apparatus is designed to save space. Can be realized.

  Note that the present invention is not limited to the image forming apparatus described in the above-described embodiment, and any image forming apparatus or paper having a configuration different from that of the present embodiment may be used as long as it has a configuration for conveying paper. It can be deployed in various devices related to transportation.

1 is an explanatory diagram showing an overall configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a partial detail view showing a configuration of an apparatus main body of the image forming apparatus. FIG. 4 is an explanatory diagram illustrating a configuration of a sheet conveyance path of the image forming apparatus. FIG. 4 is a partial detail view illustrating a configuration of a branched paper conveyance path that constitutes the paper conveyance path and a branching claw that connects the branched paper conveyance paths. It is explanatory drawing which shows the structure of the paper collection | recovery apparatus of the said paper conveying apparatus. FIG. 6 is an explanatory diagram illustrating a sheet conveyance state by face-up discharge during single-side printing in the sheet conveyance path. FIG. 6 is an explanatory diagram illustrating a paper conveyance state by face-down paper discharge during single-side printing in the paper conveyance path. It is explanatory drawing which shows the paper conveyance state at the time of double-sided printing in the said paper conveyance path. FIG. 2 is a block diagram illustrating a configuration of an electric control unit of the image forming apparatus.

Explanation of symbols

1A Image forming apparatus 3 Photosensitive drum (electrostatic latent image carrier)
6 Fixing unit (fixing means)
7 Paper transport device (recording medium transport means)
7a Paper transport path (recording medium transport path)
7a1 First paper transport path 7a2 Second paper transport path 7a3 Third paper transport path 7a4 Fourth paper transport path (switchback transport path)
7a5 Fifth paper transport path (recording medium reversal transport path)
7a6 6th paper conveyance path 7a7 7th paper conveyance path 7a8 8th paper conveyance path 9 Paper discharge tray 14 Image forming part 15 Registration roller 90 Paper collection apparatus (recording medium collection part)
91 Paper storage portion 91a Tray portion 91b Spring material 92 Paper supply structure 92a Pickup roller 92b Sakiaki roller 92c Sakiki member 92d Collected paper transport path 92e Branching claw 93 Alignment portion (Alignment member)
93a Push plate 93b Spring member (elastic member)
P paper (recording medium)
P1 one end P2 other end

Claims (12)

An electrostatic latent image carrier on which a developer image is formed by a developer, an image forming unit that transfers the developer image on the surface of the electrostatic latent image carrier to a recording medium, and the image is transferred onto the recording medium. Image forming apparatus that includes a fixing unit that fixes the developer image on the recording medium and a recording medium conveying unit that discharges the recording medium after the developer image fixing process to a paper discharge tray and outputs an image in response to a print request Because
The recording medium conveying means includes a recording medium conveying path for conveying the recording medium after the developer image fixing process again toward the image forming unit,
A recording medium recovery unit for retracting and storing a normal recording medium staying in the recording medium conveyance path when a paper jam occurs in the recording medium during the printing process in the image forming apparatus; An image forming apparatus comprising the image forming apparatus. The recording medium conveyance path is disposed on the upstream side in the sheet conveyance direction of the image forming unit from the switchback conveyance path and the switchback conveyance path for reversing the recording medium after the developer image fixing process. And a recording medium reversing conveyance path that conveys toward the registration roller,
The image forming apparatus according to claim 1, wherein the recording medium recovery unit is provided in the middle of the recording medium reversal conveyance path.   The image forming apparatus according to claim 1, wherein the recording medium collected by the recording medium collecting unit is a recording medium that has passed through at least a fixing unit.   The recording medium recovered by the recording medium recovery unit is a recording medium that is being conveyed for the double-sided printing process after the single-sided printing process is completed in the printing process mode in which the double-sided printing process is performed. Item 3. The image forming apparatus according to Item 1 or 2.   5. The recording medium collecting unit according to claim 1, wherein the recording medium collecting unit stores the conveyed recording medium from the upstream side in the recording medium conveying direction and discharges the recording medium from the downstream side in the recording medium conveying direction. The image forming apparatus described in the item.   6. The recording medium collecting unit according to claim 1, wherein the recording medium collecting unit stacks the recording mediums in the transported order and discharges the recording media in order from the recording medium above the stacked recording medium. The image forming apparatus described in the item.   The recording medium recovery unit includes a recording medium supply structure for supplying the recovered recording medium again, and the recording medium supply structure includes at least a pickup roller for discharging the recording medium and a sucker roller for separating the recording media one by one. An image forming apparatus according to any one of claims 1 to 6, further comprising:   The image forming apparatus according to claim 7, wherein when the recording medium is collected, the recording medium supply structure is retracted in a range that does not interfere with the collected recording medium.   9. The image forming apparatus according to claim 7, wherein the recording medium supply structure is disposed on a rear end side of the recording medium with respect to a conveyance direction when the recording medium collecting unit collects the recording medium. The recording medium recovery unit includes an alignment member that aligns the stored recording medium,
10. The alignment member according to claim 1, wherein the alignment member is configured to be capable of changing a length of a recording medium storage area of the recording medium recovery unit in accordance with a length of the recording medium stored. The image forming apparatus according to any one of the above.   The image forming apparatus according to claim 10, wherein the alignment member is disposed on a leading end side of the recording medium with respect to a conveyance direction when the recording medium collecting unit collects the recording medium.   The image forming apparatus according to claim 11, wherein the alignment member aligns the recording medium by pressing one end of the recording medium accommodated via an elastic member.

Images