JP5181705B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, a printer, a plotter, etc., and a multifunction machine having at least two functions.

In an image forming apparatus such as a copying machine, a facsimile machine, a printer, a plotter, and a multi-function machine having at least two functions, an image forming apparatus capable of selecting and executing various sheet processes is assembled as necessary, and the installation area A technique relating to an image forming apparatus and a sheet processing apparatus that are made based on the problem of providing a small, small, and low cost is known (see, for example, Patent Document 1).
In the technique described in Patent Document 1, a plurality of unitized sheet processing apparatuses are connected so as to overlap each other in a vertical direction, and designated sheet processing is performed. The unitized sheet processing apparatus is used as an image forming apparatus. The apparatus main body before being connected to the apparatus main body has a conveyance path and a sheet passing path which are not originally required for connection to the sheet processing apparatus.

In an image forming system in which the post-processing apparatus is assembled so as to be substantially aligned with the upper surface of the recording material supply apparatus along with the image forming apparatus, a technique for further reducing the installation area of the entire image forming system has been proposed (for example, a patent). Reference 2).
In the technology described in Patent Document 2, a vertically long image forming apparatus is formed on a paper feed cassette unit, and a post-processing device is attached to the remaining space (area).

  In addition, an image forming apparatus that prevents the installation area from being increased even if the required number of additional discharge trays and additional discharge post-processing devices are added by using a support connected to the main body. A technique related to this is also proposed (see, for example, Patent Document 3).

  Further, when the binding process is performed on the sheet on which the image is formed by the image forming unit, the sheet discharged from the discharge roller pair is supported by the alignment unit, and then the processed sheet is discharged to the second sheet stacking unit. On the other hand, if no processing is performed on the sheet, the sheet discharged from the pair of discharge rollers can be directly discharged to the second sheet stacking unit without being supported by the aligning means, so that the installation area and cost can be reduced. A technology relating to a sheet processing apparatus and an image forming apparatus including the sheet processing apparatus has also been proposed (see, for example, Patent Document 4).

Japanese Patent Laying-Open No. 2007-70096 (FIGS. 1 and 14) JP 2002-278194 A JP 11-65195 A JP 2003-73011 A

However, the technique described in Patent Document 1 does not have an idea of using an existing sheet conveyance path, and has a problem that an extra conveyance path is provided in the apparatus main body of the image forming apparatus.
The technique described in Patent Document 2 results in a vertically long special image forming apparatus.

The technique described in Patent Document 3 has a problem that it is essential to add a support body connected to the main body.
The technique described in Patent Document 4 has a problem that due to its configuration, a scanner or the like cannot be mounted, and a multifunction printer (multifunction printer: hereinafter also referred to as “MFP”) cannot be supported.

Therefore, the present invention has been made in view of the above-described problems and circumstances, and by utilizing the existing double-sided path that the image forming apparatus has in the apparatus main body, without modifying the apparatus main body, The first object is to enable post-processing by a post-processing device additionally installed on the bottom surface of the apparatus main body. With this configuration, a full front desktop that discharges paper from the front to the back of the main body of the apparatus, a small installation space, which is an advantage of the MFP, and easy handling of sheets such as recording paper are not impaired, and it is difficult. Installation of aftertreatment equipment is also solved.
If a post-processing device is additionally installed directly in the paper outlet of the main unit (this machine), the recording paper discharged after the post-processing is further to the rear than the in-body paper discharge tray position before the post-processing device is installed. A paper discharge tray will be installed and the user will not be able to take out the recording paper. At the same time, the machine will be large in the depth direction due to the paper discharge tray, the wall surface cannot be installed, and the in-body paper discharge unit will be used. Impossible, it becomes difficult to open and close the upper cover by exchanging consumables such as all-in-one (hereinafter also referred to as “AIO”) (a cartridge for supplying toner and a cartridge including a photoreceptor). When an intermediate conveyance path is used for the discharge port of the apparatus main body and the front-side-back-front side U-turn path is formed and the front-side paper is discharged, it is difficult to secure a space for forming the U-turn path in the body. It is difficult to handle paper types such as cardboard that cannot make the turn radius small. Further, when the U-turn path is performed outside the machine that has passed through the inside of the body, an increase in size is inevitable and the transport distance becomes enormous. In addition, when the first printing surface faces the paper ejection surface → back paper ejection, the recording paper stacking order is stacked on the first printing surface with the second and third sheets in one U-turn. Cannot staple. Therefore, an object of the present invention is to solve all the above problems.

In order to solve the above-described problems and achieve the above-mentioned object, the present invention employs the following characteristic means / configuration in the invention of each claim.
The invention according to claim 1 includes a sheet feeding cassette that is detachable with respect to the apparatus main body, and is disposed above the sheet feeding unit and a sheet feeding unit that feeds a sheet from the sheet feeding cassette. An image forming unit that forms an image on the sheet fed from the sheet feeding unit, a first sheet conveyance path that guides the fed sheet to contact the image forming unit, and a first sheet conveyance and out exhaust to the rear side of the sheet with the image formed a tract in street said image forming unit from the apparatus main body front, and a sheet discharge unit having a switchback means for switching back the sheet, placed on top of the image forming unit A sheet stacking section for stacking image-formed sheets discharged from the sheet discharge section in the sheet discharge direction, and a transport path different from the first sheet transport path, and switched by the switchback means. After reversing the back-formed image-formed sheet, the sheet passes through a part of the sheet feeding unit to reach the first sheet conveyance path again, and comes into contact with the image forming unit, thereby the other sheet of the sheet. A second sheet conveying path for forming an image on the surface, and a bottom portion of the sheet feeding section capable of receiving a sheet conveyed toward the bottom of the sheet feeding section from the middle of the second sheet conveying path disposed, have a, a post-processing device configured to detachably attached to the apparatus main body, a sheet feeding port of the sheet fed from the sheet feeding cassette is disposed in the image forming section A secondary transfer portion and a paper discharge port for discharging a sheet on which an image is formed from the sheet discharge portion to the sheet stacking portion are arranged in this order from the bottom toward the top of the apparatus main body, Whether the second sheet conveyance path is the discharge port The second sheet conveying path is formed in a curved shape so as to communicate with the sheet feeding port, and the lowest point of the second sheet conveying path is disposed in the vicinity of the lowermost surface of the apparatus main body. A sheet feeding / post-processing path that branches from the vicinity of the lower point and communicates with the post-processing apparatus is provided, and the apparatus main body further includes a sheet feeding cassette that is detachable from the apparatus main body. An image forming apparatus , wherein the positioning unit of the post-processing apparatus with respect to the apparatus body has the same configuration as the positioning unit of the sheet feeding cassette to be added .

According to a second aspect of the invention, Te claim 1 the image forming apparatus odor description, the power supply means of the post-processing apparatus for pre-Symbol apparatus main body has the same configuration as the power supply means of the sheet feeding cassette to add pre-Symbol It is characterized by.

According to a third aspect of the invention, Te claim 1 or 2, the image forming apparatus odor description, signal communication means of the post-processing apparatus for pre-Symbol apparatus main body, the same configuration as the signal means before Symbol add a sheet feeding cassette It is characterized by having.

According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, a conveyance direction switching unit capable of switching a sheet conveyance direction in the middle of the second sheet conveyance path. In the sheet feeding unit.

According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, a drive unit for the transport direction switching unit is provided in the post-processing apparatus.

According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects, a manual feeding unit is disposed in the apparatus body, and a sheet from the manual feeding unit is provided. An image forming apparatus having a detection mechanism including a sheet detection unit for detecting a feeding state in the post-processing apparatus.

According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the first to sixth aspects, the post-processing device includes a sheet conveyance path, a sheet aligning unit, and a post-processing unit, and the post-processing And the support portion of the post-processing apparatus are configured to be separable.

According to an eighth aspect of the present invention, in the image forming apparatus according to any one of the first to seventh aspects, the post-processing device includes a sheet storage unit that stores a post-processed sheet, and the sheet storage The means is configured to be detachable from the post-processing apparatus main body, and an expanded sheet storage means can be attached to the bottom of the post-processing apparatus main body after being detached from the post-processing apparatus main body. It is characterized by that.

According to the present invention, it is possible to realize and provide a novel image forming apparatus capable of solving the above problems and achieving the above object. The effects for each claim of the present invention are as follows.
According to the first aspect of the present invention, in particular, the sheet feeding port of the sheet feeding cassette, the secondary transfer unit, and the sheet ejection port in the above configuration are arranged in this order from the bottom toward the top of the apparatus main body. The second sheet conveying path is curved so as to communicate from the sheet discharge port to the sheet feeding port, and the lowest point of the second sheet conveyance path is near the lowermost surface of the apparatus main body. The apparatus main body may be increased in size by being provided with a sheet feeding / post-processing path that is branched from the vicinity of the lowest point of the second sheet conveyance path and communicates with the post-processing apparatus. Absent. In addition, since it has a post-processing device disposed at the bottom of the sheet feeding unit so as to be able to receive a sheet conveyed in the bottom direction of the sheet feeding unit from the middle of the second sheet conveyance path, By using, for example, an existing double-sided path as the second sheet conveyance path, installation space is not increased, access to the in-cylinder discharge sheet is not deteriorated, and all-in-one type cartridge replacement related to toner supply, for example, is performed. As well as the fact that it does not require any intermediate conveyance path without deteriorating the property, it is possible to discharge the normal printed matter by using the sheet discharge port of the post-processing device, so it has excellent access to the printed matter as a desktop machine, Since it is added to the lower part of the device body, it is easy to cope with the tilt problem, and the device body and the post-processing device are connected and fixed by their own weight. A lock can be configured without the need for, yet can be dealt with options added. In addition, since the positioning means of the post-processing apparatus with respect to the apparatus main body has the same configuration as the positioning means of the sheet feeding cassette (hereinafter also referred to as “additional sheet feeding cassette”) added to the apparatus main body, To increase the repertoire of optional components.

According to the second aspect of the invention, the feeding means of the post-processing apparatus with respect to the apparatus main body, since it has the same configuration as the power supply means of the additional sheet feeding cassette, for example, feed port for adding the sheet feeding cassette and the post-processing apparatus It is possible to make a common part without installing a power supply cable and the apparatus main body is not enlarged.

According to the third aspect of the present invention, the signal communication means of the post-processing apparatus for the apparatus main body has the same configuration as the signal means of the additional sheet feeding cassette. It can be configured to be a common part without installing a port or signal communication cable, and the apparatus main body does not increase in size.

According to the fourth aspect of the present invention, the sheet feeding unit has the conveyance direction switching means capable of switching the sheet conveyance direction in the middle of the second sheet conveyance path. Can be configured to not be enormous.

According to the fifth aspect of the present invention, since the drive unit for the conveyance direction switching means is included in the post-processing apparatus, the cost of the apparatus main body can be suppressed without increasing the apparatus main body itself.

According to the invention described in claim 6 , since the post-processing apparatus includes the detection mechanism including the sheet detection unit that detects the sheet feeding state from the manual feeding unit, the apparatus main body is not enlarged. The cost increase can be suppressed, and malfunction can be prevented.

According to the seventh aspect of the present invention, the post-processing section and the support section of the post-processing apparatus are configured to be separable, so that jam processing, consumable replacement and maintenance can be easily performed.

According to the invention described in claim 8 , the sheet storage means is configured to be detachable from the post-processing apparatus main body, and extends to the bottom of the post-processing apparatus main body after being detached from the post-processing apparatus main body. Since the sheet storage means can be mounted, user selectivity with respect to function and installation height is improved.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention including examples will be described with reference to the drawings. First, before describing the embodiment, the operation of the image forming apparatus to which the present invention is applied will be described with reference to FIGS. The image forming apparatus shown in FIGS. 1 to 6 is a multifunction printer (hereinafter, abbreviated as “MFP”) configured to be able to add a multifunctional configuration such as a scanner or a post-processing apparatus according to an embodiment described later. This is an example of various configurations configured without impairing the small installation space, which is also an advantage of the full front desktop that discharges from the user's front to the back, and the ease of discharging the discharged recording paper, etc. It has the following new features.

FIG. 1 is an external perspective view of an image forming apparatus to which the present invention is applied, and FIG. 2 is a schematic longitudinal sectional view showing an example of an internal configuration of the image forming apparatus.
The image forming apparatus shown in FIG. 1 and FIG. 2 is disposed almost at the center of the apparatus main body 1, and is disposed below the image forming section 2 and an image forming section 2 having an image forming means for forming an image on a sheet. The sheet feeding unit 20 serving as a sheet feeding unit that feeds the sheet S to the image forming unit 2, and single-sided conveyance as a first sheet conveyance path that guides the fed sheet so as to contact the image forming unit 2. A path 67 (see FIG. 7), an image reading unit (hereinafter also referred to as “scanner”) 30 disposed above the image forming unit 2 with a space therebetween, and a sheet on which an image is formed by the image forming unit 2 A sheet discharge unit serving as a sheet discharge unit that discharges from the front of the apparatus main body 1 (the right side of both drawings) to the back side (the left side of both drawings), and an upper portion of the image forming unit 2. Stack sheets to be discharged in the discharge direction (discharge direction) Xa The sheet stacking unit 40 and a conveyance path different from the single-sided conveyance path 67 are reversed after an image-formed sheet that has been switched back by a pair of sheet discharge rollers 25 described later as a switchback unit. , The double-sided conveyance path 71 and the re-conveyance path 24 as a second sheet conveyance path for forming an image on the back surface of the sheet by contacting the image forming unit 2 again. And a manual paper feed unit 45 as a manual feed unit that is disposed at the lower part of the apparatus main body 1 and includes a manual paper feed port (manual feed port) 46.
That is, the image forming apparatus shown in both figures is a tandem type color image forming apparatus with a scanner, and a predetermined space for discharging the sheet is formed between the sheet stacking unit 40 and the scanner 30. It is also an in-body discharge type image forming apparatus.

A pair of paper discharge rollers 25 constituting the same part are disposed in the sheet paper discharge unit. The paper discharge roller pair 25 includes a driving roller and a driven roller, and also functions as switchback means for switching back the sheet. The discharge roller pair 25 is driven to rotate on the drive roller side by a drive means such as a motor (not shown). The drive roller side of the paper discharge roller pair 25 is driven and controlled so as to be rotated forward and backward at a predetermined sheet detection timing by controlling drive means such as a motor in accordance with a command from a control means (not shown). .
In FIG. 1 and the like, Y indicates a sheet width direction orthogonal to the sheet discharge direction Xa, the sheet discharge direction Xa is also a slide direction described later of the scanner 30, and Xb is a slide in a direction opposite to the slide direction Xa. Direction.
The image forming unit 2 is also referred to as an image recording unit 2 that records an image on the sheet S, and the sheet stacking unit 40 is also referred to as a sheet mounting unit 40 that mounts and stacks discharged sheets.

  As shown in FIG. 2, the image forming unit 2 includes a plurality of drum-shaped photoconductors 3a, 3b, 3c, and 3d configured as image carriers, and the photoconductors 3a to 3d are connected to each other. Different color toner images are formed. In the illustrated example, a yellow toner image, a cyan toner image, a magenta toner image, and a black toner image are formed on the surfaces of the photoreceptors 3a to 3d, respectively. The photoconductors 3a to 3d are arranged in parallel with each other at a predetermined interval, and an intermediate transfer belt 4 configured as an intermediate transfer body is arranged facing the lower portions of the photoconductors 3a to 3d. As the intermediate transfer member, a drum can be used, but in the illustrated example, an intermediate belt composed of an endless belt wound around a plurality of support rollers 5 and 6 and driven in the direction of the arrow (counterclockwise in FIG. 2). A transfer belt 4 is used.

  Since the configuration around each of the photoconductors 3a to 3d is the same, the photoconductor 3a on which the yellow toner image arranged on the rightmost side in FIG. 2 is formed will be described as a representative. That is, the photoconductor 3a includes exposure of a charging device 7 that uniformly charges the surface of the photoconductor 3a, and an optical scanning device (LSU) 8 that irradiates the surface of the photoconductor 3a with laser light. , A developing device 9 that visualizes the electrostatic latent image formed on the surface of the photoconductor 3a by exposure, a transfer device 10 that is disposed to face the photoconductor 3a via the intermediate transfer belt 4, and an intermediate transfer belt 4, a cleaning device 11 for removing and recovering toner remaining on the surface of the photoreceptor 3a after transfer is provided in this order.

  When image formation is started in such an image forming apparatus, the photoreceptor 3a is rotationally driven in the clockwise direction in FIG. 2, and at this time, the charging device 7 uniformly charges the surface of the photoreceptor 3 to a predetermined polarity. Next, the charged surface is irradiated with laser light based on image information from the optical scanning device 8, thereby forming an electrostatic latent image on the photoreceptor 3 a. The electrostatic latent image formed on the surface of the photoreceptor 3 a is visualized as a yellow toner image by the developing device 9, and the yellow toner image is transferred onto the intermediate transfer belt 4 by the transfer device 10.

  At the time of full color image formation, the above-described image forming operation is performed in the same manner on all the remaining photoconductors 3b to 3d, whereby yellow toner images, cyan toner images, and magenta toner images respectively formed on the respective photoconductors 3a to 3d. Then, the black toner image is sequentially superimposed and transferred onto the intermediate transfer belt 4. In the image forming apparatus, a secondary transfer roller 12 is disposed so as to face the support roller 6 with the intermediate transfer belt 4 interposed therebetween.

  On the other hand, a paper feed unit 20 disposed below the image forming unit 2 has a paper feed tray 21 serving as a sheet storage unit on which sheets S made of transfer paper or resin film are stacked, and a stack on the paper feed tray 21. A sheet feeding roller 22 that feeds the sheet S, a friction pad 23 as a separating unit that separates the multi-fed sheets into one sheet, a re-conveying path 24 that is used when forming a double-sided image, and the like are provided.

  The sheet S fed from the sheet feeding unit 20 is fed toward the pair of registration rollers 13 and is once abutted against the registration rollers 13 whose leading ends are stopped. As a result, after the oblique deviation of the leading edge of the sheet S is corrected and aligned, the registration roller 13 causes the color toner image formed on the intermediate transfer belt 4 to be sheeted at the secondary transfer portion provided with the secondary transfer roller 12. The rotation is resumed at a predetermined timing so as to coincide with the leading end portion of S, and the sheet S is sent out toward the secondary transfer portion.

The sheet S on which the unfixed color toner image is transferred in the secondary transfer unit is sent to the fixing unit 14 composed of a fixing device, and after the unfixed color toner image is fixed by heating and pressing by the fixing unit 14. Then, the sheet is discharged to a sheet stacking unit 40 provided on the upper surface of the apparatus main body 1 via a sheet discharge roller pair 25 of the sheet discharge unit. The transfer residual toner adhering to the surface of the intermediate transfer belt 4 after the color toner image is transferred is removed by a belt cleaner 15.
As described above, the sheet conveyance path to the sheet feeding roller 20 as the sheet feeding unit 20, the registration roller 13, the secondary transfer unit provided with the secondary transfer roller 12, the fixing unit 14, and the sheet ejection unit is appropriately set. A single-sided conveyance path (single-sided conveyance path) 67 shown in FIG. 7 and the like is formed together with a guide member (not shown).
The double-sided conveyance path (double-sided conveyance path) 71 is also formed by a guide member (not shown) provided as appropriate, and a conveyance roller 75 including a pair of driving rollers and a driven roller is arranged at a substantially intermediate position. Yes.

Next, the operation during double-sided image formation will be described. By the operation as described above, first, an image is transferred from the intermediate transfer belt 4 to one side of the sheet, and the sheet passing through the fixing unit 14 via the single-sided conveyance path 67 shown in FIG. By being driven to rotate in the rotation direction, the sheet is conveyed to the sheet stacking surface 41 side, and when the trailing edge of the sheet has passed through the sheet detection sensor 82 shown in FIG. As a result, the sheet that has been the rear end of the sheet until now is used as the leading edge, and the sheet is conveyed toward the conveying roller pair 75 while being guided toward the double-sided conveying path 71 by the strength of the sheet itself. Thereafter, the sheet is reversed through the U-shaped re-conveying path 24 and reaches the registration roller 13 as described above. When the sheet having an image on one side is conveyed again toward the secondary transfer portion where the secondary transfer roller 12 is provided at a timing by the registration roller 13, the toner image on the intermediate transfer belt 4 is transferred to the sheet. It is transferred to the other side.
In this example, the purpose is to realize an image forming apparatus that is as simple, small, and inexpensive as possible. Therefore, the sheet is guided to the double-sided conveyance path 71 side by the strength of the waist of the sheet itself. In the case of using thin paper or the like, not only a mechanism similar to a branching claw 90 shown in FIG. 13 and FIG. 14 described later, but also known means such as switching of a sheet conveyance path by a guide member is used as appropriate. Also good.

Images to be formed on the other side of the sheet are sequentially formed by an image forming process that is started when the sheet is conveyed to a predetermined position. The image forming process in this case is also the same as the full color toner image formation at the time of the above-mentioned single-sided image formation, and this full color toner image is carried on the intermediate transfer belt 4. However, since the front and rear of the sheet are reversed in the refeed path 24, the image data emitted from the optical scanning device 8 is formed so that the image is formed in the opposite direction in the sheet conveyance direction with respect to the first image formed. Is controlled and executed.
The sheet having the full-color toner image transferred on both sides is again subjected to fixing processing by the fixing unit 14 via the single-sided conveyance path 67, and is then placed on the sheet stacking surface (discharge tray) 41 by the discharge roller pair 25. The paper is ejected. In order to increase the efficiency of double-sided image formation, the timing of forming images to be formed on the front and back sides of the paper is executed by a control means (not shown).

  As in the case of a general image reading apparatus, the scanner 30 is provided with a mechanism for setting an original on the upper part of the apparatus body and scanning an image of the original, and an original for pressing and holding the original. A platen cover 31 as a pressing member is provided. The platen cover 31 is configured to be swingable and openable around a hinge 38 with respect to the housing of the scanner 30. As shown in FIG. 1, the platen cover 31 includes an automatic document feeder (ADF) 32, and the scanner 30 performs both of a document set manually and a document fed by the automatic document feeder 32. Reading can be done. Further, the scanner 30 is supported via a support unit 50 with respect to the apparatus main body 1 arranged at the lower part.

  1 and 2, reference numeral 16 denotes a control panel for controlling operations of the scanner 30 and the image forming unit 2, and the side on which the control panel 16 is arranged is the front of the image forming apparatus. Therefore, in this image forming apparatus, the sheet discharge portion (the arrangement portion of the discharge roller pair 25) is arranged on the front side which is the front of the apparatus main body 1, and the sheet discharged to the sheet stacking section 40 is the front of the apparatus main body 1. -It has a front discharge type device configuration that discharges paper from the near side to the far side / rear side.

  An upper cover 18 as an upper cover member that covers the image forming unit 2 is provided on the upper portion of the apparatus main body 1, and an upper surface portion of the upper cover 18 is used as a sheet stacking surface 41 of the sheet stacking unit 40. The upper cover 18 is provided with a support portion 50 that supports the scanner 30. The support unit 50 of this example is disposed along the left and right side edges of the upper cover 18. In other words, the support unit 50 forms a space between the sheet stacking unit 40 and the scanner 30, and the sheet stacking unit 40. Are arranged along the sheet discharge direction Xa on both outer sides in the sheet discharge direction Xa, and are arranged to support the scanner 30 so as to be slidable. The support portion 50 includes two first support portions 51 and a second support portion 52, but no support portion is provided on the rear end side of the upper cover 18. With this configuration, even if the long sheet is longer than the width in the front-rear direction of the sheet stacking surface 41 of the upper cover 18, a part of the sheet is hung to the rear side beyond the sheet stacking surface 41, and the long sheet is stored without any problem. can do. Furthermore, if the scanner 30 is above the sheet stacking unit 40, it is inevitable that the sheet stacking surface 41 becomes dark. However, since the rear end side support unit is not provided, daylighting can be obtained. Can alleviate that problem.

  Further, as shown in FIGS. 1 to 3 and the like, the upper cover 18 supports an optical scanning device 8 which is a part of the image forming unit (image forming means) 2 at the lower portion thereof, and the rear end side of the device. It is configured to be able to open upward with a hinge 17 provided in the center. The upper cover 18 is locked to the apparatus main body 1 by a lock lever 60 serving as a locking means, which will be described later. When the lock is released, the upper cover 18 becomes swingable and openable. As shown in FIG. 3, when the upper cover 18 is swung and opened counterclockwise, the scanner 30 and the lower optical scanning device 8 are swung up together via the upper support portions 51 and 52. Thus, it is possible to access the image forming unit, and maintenance and the like can be easily performed. Further, in this example, the photoconductors 3a to 3d of the image forming unit 2 from the portion where the upper cover 18 is opened, and the charging device 7, the developing device 9 and the cleaning device 11 respectively arranged around these are integrated in an all-in-one type. These four process cartridges can be removed and mounted for replacement.

  When the upper cover 18 is swung / released, it is swung up so that the rear end side of the sheet stacking surface 41 is down, but it is swung inadvertently when sheets are stocked on the sheet stacking surface 41. If it is moved or released, there is a problem that the stocked sheet falls to the rear side of the apparatus. This problem can be solved by providing the support portion 50 also on the rear end side of the upper cover 18. However, in the case of a long sheet, the rear end support portion is hit and the stock is disturbed.

  Therefore, in this example, an operation unit 61 for releasing the lock of the lock lever 60 and allowing the upper cover 18 to swing and be opened is provided on the sheet stacking surface 41 at a position hidden by the stocked sheets S. Yes. The lock lever 60 is integrally provided with an operation portion 61 operated by a user on one end side and a lock claw 62 engaged with a protrusion 64 fixed to the apparatus main body 1 on the other end side. The lock lever 60 is rotatably supported around a pin 63 fixed to the upper cover 18, and the lock claw 62 is always engaged with the protrusion 64 by a torsion coil spring (not shown) mounted around the pin 63. A swinging urging force in the direction to match is applied. The operation unit 61 of the lock lever 60 is formed of a plate material having a surface that is on the same plane as the sheet stacking surface 41, and the sheet stacking surface 41 can be touched by the operation unit 61. A fan-shaped recess 44 shown in FIG. 1 is formed.

As described above, when the upper cover 18 is opened, a hand is inserted from the concave portion 44, and the operation portion 61 of the lock lever 60 is lifted up against the urging force of a torsion coil spring (not shown). The lock claw 62 is removed from the protrusion 64 by rotating clockwise around the pin 63. Then, the upper cover 18 is swung around the hinge 17 in the same direction as the swinging / releasing direction of the automatic document feeder 32 by lifting the operation unit 61 as it is.
As described above, since the operation portion 61 of the lock lever 60 that enables the upper cover 18 to swing and open / close is disposed on the sheet placement surface 41 on which the sheets S are stocked, the sheet S is placed on the sheet stacking surface 41. It is reliably prevented that the upper cover 18 is swung and opened in a certain state.

  As described above, in the image forming apparatus in which the scanner 30 is disposed above the sheet placement unit 40, the visibility of the stocked sheets and the sheet take-out performance are deteriorated as compared with the image forming apparatus without the scanner 30. Is inevitable. Therefore, in the image forming apparatus of this example, the scanner 30 can be slid in the arrow B direction parallel to the sheet discharge direction Xa of FIG. 2 by the two support portions 51 and 52 in order to improve the deteriorated sheet visibility and sheet take-out performance. The working space formed at the interval between the sheet discharge portion (the arrangement portion of the discharge roller pair 25) and the scanner 30 can be widened by sliding the scanner 30 to the back side. .

  Specifically, as shown in FIGS. 1 and 2, a space between the scanner 30 that accesses the sheet stacking unit 40 and the apparatus main body 1 is greatly opened toward the front, and the width of the front opening 42 is as follows. Since the opening is larger than the width of the discharged sheet, the visibility of the sheet discharged to the sheet stacking surface 41 and the ease of taking out the sheet are good. Further, in order to improve sheet visibility and sheet take-out property, a first taper portion 37 is formed at the lower corner of the front surface of the scanner 30. Similarly, a second taper portion 37 is also formed above the control panel 16 of the apparatus main body 1. A tapered portion 19 is formed to increase the opening area of the front opening 42. In particular, the second tapered portion 19 in this example has a tapered shape so that the opening area increases toward the outside of the opening, and it is easy to insert a hand into the opening when taking out the discharged sheet. ing. This configuration may be provided in the first tapered portion 37, or may be any shape as long as the opening area of the front opening portion 42 is not limited to a tapered shape.

As described above, in FIG. 1 and FIG. 2, the discharge space between the scanner 30 and the apparatus main body 1 is greatly opened toward the front surface. Is excellent.
However, if the size of the apparatus in the depth direction is reduced and the height is reduced, the size of the front opening 42 is also reduced, making it difficult to insert a hand into the paper discharge space, and the sheet is not in the scanner 30. Or the sheet discharge section (arrangement section of the discharge roller pair 25), and the ease of taking out the sheet is sacrificed. For example, in FIG. 2, the scanner 30 protrudes rearward from the rear part of the image forming unit 2 and the apparatus main body 1, but when the rear part of the scanner 30 and the apparatus main body 1 are combined to reduce the size of the apparatus, the front opening 42. Becomes smaller. However, depending on the installation environment of the user, the ease of taking out the sheet is more important than the size of the apparatus. Also, the ease of taking out differs depending on the user, so the size of the front opening 42 can be adjusted. It is desirable that a plurality of moving positions can be selected, so that it is possible to provide usage conditions suitable for various users.

As shown in FIGS. 4A and 4B, the scanner 30 includes right and left slide mechanisms that are slidably supported in the front-rear direction of the apparatus body 1, in other words, in the sheet discharge direction or the slide directions Xa and Xb. It can be moved via the support portions 51 and 52. Although the description of the scanner 30 is omitted, the scanner 30 can be assembled by sliding in the sliding direction Xb from the rear side of the apparatus. When the scanner 30 is slid in the sliding direction Xb as shown in FIG. Occupies the position shown in FIG.
At this time, the back surface of the scanner 30 is equivalent to the back surface of the image forming unit 2, and the machine size is minimized. When packing is performed in the state shown in FIG. 4B as described above, since there are few irregularities, a large amount of packing material is not used, and the packing volume is small. Since it increases, it can be said to be environmentally friendly. Since the scanner 30 is attached in the engagement relationship between the stepped screw pin and the groove, which are not described, so that the scanner 30 does not come off in the insertion direction / removal direction, the scanner 30 does not come off from the support portions 51 and 52.

Characteristic configurations of the slide mechanism and the lock mechanism between the scanner 30 and the support unit 50, such as a mechanism for preventing the scanner 30 from coming off from the support unit 50 and a mechanism for locking and unlocking the scanner 30, etc. However, since it exceeds the scope of the disclosure of the present invention, further explanation is omitted.
1 and 4 denotes an operation button for releasing the state in which the scanner 30 is locked and fixed at a predetermined position with respect to the support unit 50. By pressing the operation button 70, the lock / engagement state of the left and right support portions 52, 51 and the left and right rail members (not shown) attached to the bottom wall of the scanner 30 is released in conjunction with each other, thereby releasing the scanner 30. Is slidable.

As shown in FIG. 5, the apparatus main body 1 has a front cover 27 that can be opened and closed via a hinge 28. By opening the front cover 27, the unit of the intermediate transfer belt 4, the waste toner bottle 65, Replacement maintenance for the fixing unit 14 and processing of jammed paper in the sheet conveyance path in the apparatus main body 1 can be performed.

Further, as shown in FIG. 6, the apparatus main body 1 has an opening 29 for inserting the paper feed tray 21 in the front cover 27, and the paper feed tray 21 extends from the opening 29 in the left-right direction in the drawing (front side of the main body). From) is configured to be detachable. FIG. 6 shows a state in which the paper feed tray 21, the friction pad 23, and the reconveying path 24 are taken out from the apparatus main body 1 in the P direction (also in the Xb direction in FIG. 4 and the like) and detached. As a result, full front operation that allows maintenance, consumable replacement, jam handling, etc. to be performed from the front of the device body 1 is possible, and the installation area can be reduced and user-friendliness can be reduced without requiring a space for performing the above operations from the back. A low-cost image forming apparatus can be provided.
The paper feeding unit 20 as the sheet feeding unit shown in FIG. 1 is merely described as being disposed in the apparatus main body 1. However, in the example of FIG. 6, in the example of FIG. 23 and the re-conveying path 24 are detachable with respect to the apparatus main body 1, and it is clarified that the sheet feeding cassette 20A is configured as a detachable sheet feeding cassette. In the embodiment described later, the paper feed cassette 20 </ b> A illustrated in FIG. 6 is used as the paper feed unit 20.

(First embodiment)
Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. In the first embodiment shown in FIGS. 7 to 27, as shown in FIG. 7, the paper feeding unit 20 is a paper feeding cassette as compared with the image forming apparatus to which the present invention shown in FIGS. From the point where the sheet detection sensors 81 and 82 as sheet detection means are arranged in the single-sided conveyance path 67, and in the middle of the re-conveyance path 24 communicating with the double-sided conveyance path 71, the sheet cassette 20A The main difference is that the image forming apparatus has the post-processing device 100 arranged at the bottom of the sheet feeding cassette 20A so as to receive the sheet conveyed in the bottom direction.
That is, in order to convey the sheet to the post-processing apparatus 100, the existing double-sided conveyance path 71 and the re-conveyance path 24 (double-sided path) are used by the branching claw 90 disposed between the manual feed port 46 and the registration rollers 13. A major feature is that the sheet conveyed from the double-sided path is conveyed from the lowermost surface of the re-conveying path 24 toward the bottom surface of the sheet feeding cassette 20A.

A sheet conveyance path unique to the present embodiment will be described. As shown in FIG. 8, the existing re-conveying path 24 (hereinafter also referred to as “double-sided path 24”) branches off from the guide member shown in FIG. The nail 90 is formed.
As shown in FIG. 9, the manual paper feed path 74 (hereinafter also referred to as “manual paper feed path 74”) joins from the manual paper feed port 46 to a single-sided conveyance path 67 (see FIG. 7) (not shown). Accordingly, the guide member 92 and the branch claw 90 shown in FIG.
As shown in FIG. 10, the double-side / post-processing path 72 branches from the middle of the existing re-transport path 24 (double-side path 24), joins and communicates with the paper feed / post-processing path 73, and then the post-processing apparatus. 100 is disposed to communicate with the post-processing path 108 (see FIG. 17). The double-side / post-processing path 72 is formed by the guide members 92 and 93 and the guide members shown in FIG. The paper feed / post-processing path 73 is formed by a guide member and a branch claw 90 shown in FIG.

With reference to FIGS. 8-14, the structure and function of the branch claw 90 are demonstrated. The branching claw 90 functions as a conveyance direction switching unit capable of switching the sheet conveyance direction in the middle of the re-conveyance path 24.
As shown in FIGS. 8 and 9, a predetermined angle is rotated clockwise by a dead spring of the branch claw 90 or a winding spring (torsion coil spring) (not shown) wound on the swinging shaft 91 of the branch claw, that is, The tip 90a of the branching claw 90 that swings clockwise contacts the branching claw abutting portion 93a formed on the guide member 93 that forms the paper feeding / post-processing path 73, and stops. . The branch claw abutting portion 93a is located at a position lower than the manual paper feed path 74, and the branch claw tip 90a is lower than the manual paper feed path 74 even when the branch claw 90 contacts the branch claw abutting portion 93a. It is formed in the abutting part position which becomes a position.

  As shown in FIG. 9, when the branching claw tip 90a is located at a position lower than the manual paper feed path 74, the sheet passes through the branching claw 90 without causing jamming. As shown in FIG. 8, similarly, in the case of the double-sided path 24, both sides of the portion surrounded by the re-conveying path 24 and the branching claw 90 are caused by the branching claw tip 90 a stopping against the branching claw abutting portion 93 a. A path 24 is formed. When the post-processing apparatus 100 is not coupled to the apparatus main body 1, the branch claw 90 is always stopped in contact with the branch claw abutting portion 93a.

  With respect to the above-described points, the post-processing apparatus 100 is coupled to the apparatus main body 1 so that a force can be applied from the post-processing apparatus 100 side to swing the branching claw 90 counterclockwise. . FIG. 10 shows a path of the double-side / post-processing path 72 that passes through the double-sided path 24 toward the post-processing apparatus 100. The path of the double-sided / post-processing path 72 is to pass the lower side of the branching claw 90 without passing through the double-sided path 24 passing through the entire re-conveying path 24 by swinging the branching claw 90 counterclockwise. Become. The sheet guided downward by the sheet feeding cassette 20 </ b> A by the branching claw 90 passes through the sheet feeding / post-processing path 73 and is delivered into the post-processing apparatus 100. When the branching claw 90 swings counterclockwise, as shown in FIG. 11, the branching claw tip 90a is displaced in a direction orthogonal to the guide rib 92a of the guide member 92 formed on the re-conveying path 24. Therefore, the branch claw tip 90a fits within the height of the guide rib 92a of the guide member 92 on the re-conveying path 24 so that the jam does not occur. The sheet will pass.

  FIG. 12 is a view showing the back side of the paper feed cassette 20A. A branch claw action member 94 fixed to one end of the swinging shaft 91 of the branch claw 90 is inserted into a space formed between a part forming the paper feed / post-processing path 73 and the paper feed cassette 20A, and is subjected to post-processing. Access from the apparatus 100 is possible.

  In FIG. 13 and FIG. 14, the peripheral parts of the branch claw 90 are indicated by a two-dot chain line, and the presence / absence state of the action on the branch claw 90 from the post-processing device 100 is shown. In the post-processing apparatus 100, a push-type solenoid 95 as a driving means, a link 96 having a substantially L shape, and a bias that biases the link 96 in a direction that always swings counterclockwise about the shaft 96a. There is a driving unit for the branching claw 90 formed of a tension spring 97 as a means, and in a state where the post-processing apparatus 100 is coupled to the apparatus main body 1, one end of the link 96 forms a sheet feeding / post-processing path 73 and a sheet feeding cassette. 20A and is in a position where it can come into contact with the branch claw action member 94.

  The state shown in FIG. 13 is a state in which the branch claw tip 90a is lowered so that manual feed printing and double-sided printing are possible, the branch claw 90 swings clockwise, and stops against the branch claw abutting portion 93a. Since the pressing force from the plunger (illustrated portion) of the solenoid 95 to the link 96 is not acting, it indicates that no force is applied from the link 96 to the branch claw acting member 94. At this time, the other end of the link 96 facing the distal end of the plunger (illustrated portion) of the solenoid 95 serves as a stopper by the distal end of the plunger (illustrated portion) of the solenoid 95 that is energized by the urging force of the tension spring 97. Yes.

The state shown in FIG. 14 is such that the sheet can be conveyed to the inside of the post-processing apparatus 100 from the middle of the re-conveying path 24 through the double-sided path 24 and under the branching claw 90 toward the lower side of the sheet feeding cassette 20A. The branch claw tip 90 a is raised and the branch claw 90 is swung counterclockwise, and the plunger (illustrated portion) of the solenoid 95 that is energized presses the link 96 against the biasing force of the tension spring 97. Thus, the link 96 swings clockwise and a force is applied to the branch claw action member 94 from one end of the link 96.
In addition to the solenoid 95, the drive source / drive means for the swinging action on the branch claw 90 can be a mechanism using a motor and a cam, a mechanism using a torque limiter that idles when a predetermined torque is applied, and the like. is there.

In the model of the present embodiment, there is a single manual sheet feeding unit 45, but when the sheet is inserted into the manual sheet feeding port, the sheet is fed to the re-conveying path 24 or the duplex / post-processing path 72. Depending on the paper passing state, it is necessary to prohibit paper feeding from the manual paper feeding unit 45.
FIG. 15 shows a detection mechanism that detects the presence or absence of a sheet on the manual sheet feed port 46. FIG. 16 shows the movable pattern of the filler 112 and its detection status.
As shown in FIGS. 15 and 16, a detection mechanism including a sheet detection sensor 109 including a transmissive photosensor as a sheet detection unit that detects the sheet feeding state from the manual feeding unit 45 will be described later. One of the features is that it is included in the processing apparatus 100. In addition to the sheet detection sensor 109, the detection mechanism also includes a filler 112 that includes one end 112a and the other end 112b and is supported so as to be swingable around a shaft 112c. The shaft 112c is fixed to the filler 112 and is supported by a non-illustrated immovable member in the post-processing apparatus 100 so as to be swingable. The filler 112 is formed of a resin such as a thin sheet-like polyethylene terephthalate (PET).

In both figures, the filler 112 extending from the post-processing apparatus 100 in the direction of the paper feed cassette 20A (vertical direction) and passing through the 47 cutouts cut out in the center of the manual paper feed port 46 is the initial position (default). At position P1, the optical path of the sheet detection sensor 109 is blocked while standing upright in the vertical direction by its own weight, and the sheet detection sensor 109 is off.
On the other hand, as shown in FIG. 16, when the sheet is inserted into the manual sheet feeding port 46, the filler 112 is pushed counterclockwise by the end 112 a of the filler 112 being pushed by the sheet, so that the filler 112 detects the sheet. The position P2 is occupied, and the other end 112b of the filler 112 is detached from the sheet detection sensor 109, and the sheet detection sensor 109 is turned on to perform sheet detection.
Further, when the paper feed cassette 20A is pulled out or detached from the apparatus main body 1, one end 112a of the filler 112 is pushed by the paper feed cassette 20A, and the filler 112 rotates clockwise, so that the filler 112 is fed. The drawer detection position P3 of the cassette 20A is occupied, and the other end 112b of the filler 112 is detached from the sheet detection sensor 109. When the sheet detection sensor 109 is turned on, the other end 112b of the filler 112 is removed from the sheet detection sensor 109. When the sensor 109 is turned on, the drawer detection of the paper feed cassette 20A from the apparatus main body 1 is detected. In FIG. 16, S indicated by a broken line represents a sheet position when manually feeding, and 20 A indicated by a broken line represents a pulling locus of the sheet feeding cassette 20 A from the apparatus main body 1.

When the sheet detection sensor 109 indicates a sheet-on detection state during and after execution of post-process printing, the process is temporarily interrupted by a command from a control unit (not shown) and manually fed to the user. A display prompting the user to remove the sheet from the paper mouth 46 is displayed on, for example, a liquid crystal display unit provided in the control panel 16 shown in FIGS .

  A detailed configuration of the post-processing apparatus 100 will be described with reference to FIG. As described above, the installation position of the post-processing apparatus 100 is the bottom surface of the apparatus main body 1 and under the paper feed cassette 20A. Since the apparatus main body 1 is installed on the post-processing apparatus 100, the width and depth of the post-processing apparatus 100 are substantially equal to or greater than the bottom surface of the apparatus main body 1. The positioning of the post-processing apparatus 100 and the apparatus main body 1 is not shown on the apparatus main body 1 side by three positioning bosses 101 a, 101 b, 101 c having a taper on the upper portion standing from the post-processing apparatus 100 toward the apparatus main body 1. The position in the two-dimensional direction is determined by fitting with a hole formed on the bottom surface of the frame and having at least one fitting gap. As described above, the three positioning bosses 101a, 101b, and 101c function as positioning means of the post-processing apparatus 100 with respect to the apparatus main body 1.

  In addition, a power supply (ground) terminal 102 as a power supply unit and a signal terminal 103 (including a part of power sharing) as a signal communication unit are also provided on the coupling surface between the post-processing apparatus 100 and the apparatus main body 1. The power supply terminal 102 has a leaf spring shape and generates a pressing pressure necessary for power supply. The signal terminal 103 is coupled by a connector, and a protective guard member 104 is provided on the outer periphery of the connector for protection against damage due to contact or the like.

As shown in FIGS . 7 , 17, and 18 , the post-processing apparatus 100 includes a post-sheet conveying path that communicates with and is connected to the double-side / post-processing path 72 or the sheet feeding / post-processing path 73 shown in FIG. 10. The processing path 108, a plurality of sheet aligning rollers 106 as sheet aligning sections for receiving and aligning the sheet conveyed through the post-processing path 108 into the post-processing apparatus 100, and an abutting section 107a that abuts the sheet are integrated. And a sheet output tray 113 as a sheet storage means for storing post-processed sheets and a binding device and a punching device (not shown) as post-processing units for performing post-processing.
The post-processing apparatus 100, conveying rollers 105a that are disposed at a predetermined position of the post-processing circuit 108 consisting of a pair of driving rollers and the driven roller as the sheet conveying means for conveying the sheet, 105b, and 105c, 105 d, the post-processing A plurality of sheet detection sensors 109, 110, and 111 are disposed at predetermined positions on the path 108 and serve as sheet detection means for detecting at least one of the leading edge and the trailing edge of the sheet, and the detection mechanism described above.

  Since the post-processing apparatus 100 according to the present embodiment uses positioning means, a power feeding / feeding terminal, and a signal terminal similar to those of a paper feeding cassette that is an optional bank that is detachable with respect to the apparatus main body 1, In addition to the post-processing device 100 under the paper cassette 20A, an optional bank including an additional paper feeding cassette can be provided under the paper feeding cassette 20A of the apparatus main body 1, and a post-processing device similar to the post-processing device 100 can be additionally provided below. is there.

  Next, various printing processes (normal single-sided printing, normal double-sided printing, single-sided printing with post-processing, post-processing) in the image forming apparatus that performs post-processing under the paper feed cassette 20A through the double-sided path, which are operations unique to the present embodiment. The paper passing timing for double-sided printing with processing will be briefly described with reference to FIGS. 7 and 18 to 27. In FIGS. 7 and 18 to 27, in order to simplify the drawing and make it easy to see the state of sheet conveyance, the sheet is indicated by a thick dashed line.

(1) In the case of normal single-sided printing In the case of (1-1): b in FIG. 18 → k in FIG. 27 → paper discharged onto the sheet stacking surface 41 of the upper cover 18 or in the case of (1-2): FIG. B → c in FIG. 19 → d in FIG. 20 → e in FIG. 21 → discharged to the discharge tray 113 of the post-processing apparatus 100

(2) In the case of normal double-sided printing In the case of (2-1): b in FIG. 18 → c in FIG. 19 → h in FIG. 24 → k in FIG. 27 → sheet discharge onto the sheet stacking surface 41 of the upper cover 18 In the case of (2-2): b in FIG. 18 → c in FIG. 19 → h in FIG. 24 → c in FIG. 19 → d in FIG. 20 → i in FIG.

(3) Single-sided printing with post-processing FIG. 18 b → FIG. 19 c → FIG. 20 d → FIG. 21 e → FIG. 22 f → (post-processing) → the output tray 113 of the post-processing apparatus 100. Paper ejection

(4) In the case of double-sided printing with post-processing FIG. 18 b → FIG. 19 c → FIG. 24 h → FIG. 19 c → (second sheet switchback) → FIG. 25 i → FIG. Processing) → paper discharged to the paper discharge tray 113 of the post-processing apparatus 100

  In the case of (1-1), in normal single-sided printing in which the sheet is discharged onto the sheet stacking surface 41 (inside the cylinder) of the upper cover 18, even if the post-processing device 100 of the present embodiment is installed, as described above. Paper discharge can be performed in the same manner as when the processing apparatus 100 is not provided.

In the case of (1-2), that is, normal single-sided printing without post-processing can also be discharged to the discharge tray 113 of the post-processing apparatus 100. The sheet S is fed from the sheet feeding cassette 20A that is in the state before the start shown in FIG. The fed first sheet S1 passes through the roller nip portion of the registration roller 13, the secondary transfer roller 12, and the fixing unit 14, and the sheet detection in which the rear end in the traveling direction of the first sheet S1 is a sheet discharge sensor. The switchback is started when the sensor 82 is passed, and the feeding of the second sheet S2 is started after the switchback is started as described above.
When the first sheet S1 is conveyed via the duplex / post-processing path 72 and the sheet feeding / post-processing path 73 and passes the sheet detection sensor 110, the feeding of the third sheet S3 is started. The When the leading edge of the first sheet S1 reaches the sheet detection sensor 111, each sheet alignment roller 106 is separated from or separated from the sheet alignment table 107, and the trailing edge of the sheet movement direction is the sheet detection. When the sheet passes through the sensor 111, each sheet aligning roller 106 is driven in a direction in contact with the sheet aligning table 107, applies light pressure to the sheet and simultaneously rotates counterclockwise to remove the sheet S1 from the post-processing apparatus 100. The paper is discharged onto the paper tray 113. Further, the sheet printing surface and the order on the paper discharge tray 113 of the post-processing apparatus 100 are the same as in the in-cylinder normal single-sided printing.

  In the case of (2-1), the normal double-sided printing for discharging the sheet onto the sheet stacking surface 41 (inside the cylinder) of the upper cover 18 is similar to the normal single-sided printing, but the post-processing device 100 is not provided even if the post-processing device 100 is installed. The paper can be discharged in the same way as the time. In addition, in the case of double-sided printing, there is a space between normal printing pass + double-sided pass + switchback twice. In addition, double-sided printing prints the second page of the printed document on the first page of the sheet (front side) and the first page of the printed document on the second page of the sheet (back side). It is the same.

In the case of (2-2), that is, duplex printing without post-processing can also be discharged to the discharge tray 113 of the post-processing apparatus 100. The sheet S1 is fed from the sheet feeding cassette 20A in the state before the start shown in FIG. The fed first sheet S1 passes through the roller nip portion of the registration roller 13, the secondary transfer roller 12, and the fixing unit 14, and a sheet detection sensor whose rear end in the traveling direction of the first sheet S1 is a sheet discharge sensor. Switchback is started when passing through 82, passes through the double-sided path / re-transport path 24, and after correcting the skew deviation by the registration roller 13, the first sheet S 1 passes again through the sheet detection sensor 82. Then, after the switchback is started, the feeding of the second sheet S2 is started.
When the first sheet S1 is conveyed via the duplex / post-processing path 72 and the sheet feeding / post-processing path 73 and passes the sheet detection sensor 110, the feeding of the third sheet S3 is started. The When the leading edge of the first sheet S1 reaches the sheet detection sensor 111, each sheet alignment roller 106 is separated from or separated from the sheet alignment table 107, and the trailing edge of the sheet movement direction is the sheet detection. When the sheet passes through the sensor 111, each sheet aligning roller 106 is driven in a direction in contact with the sheet aligning table 107, applies light pressure to the sheet and simultaneously rotates counterclockwise to remove the sheet S1 from the post-processing apparatus 100. The paper is discharged onto the paper tray 113. Further, since the sheet printing surface (front surface) and the order are printed in the same order as in the cylinder normal single-sided printing, the sheet printing surface (front surface) and order are the same as in the cylinder normal single-sided printing.

Even in the case of the above-described (3) which is single-sided printing in which post-processing is performed, the sheet S1 is fed from the sheet feeding cassette 20A which is in the state before starting shown in FIG. The fed first sheet S1 passes through the roller nip portion of the registration roller 13, the secondary transfer roller 12, and the fixing unit 14, and the sheet detection in which the rear end in the traveling direction of the first sheet S1 is a sheet discharge sensor. After passing through the sensor 82, the switchback is started, and after passing through the double-sided path / reconveying path 24 and correcting the skew deviation by the registration roller 13, the first sheet S1 passes through the sheet detection sensor 82 again. Then, after the switchback starts, the feeding of the second sheet S2 is started.
When the first sheet S1 is conveyed via the duplex / post-processing path 72 and the sheet feeding / post-processing path 73 and passes the sheet detection sensor 110, the feeding of the third sheet S3 is started. The When the leading edge of the first sheet S1 reaches the sheet detection sensor 111, each sheet alignment roller 106 is separated from or separated from the sheet alignment table 107, and the trailing edge of the sheet movement direction is the sheet detection. When the sheet passes through the sensor 111, each sheet aligning roller 106 is driven in a direction to come into contact with the sheet aligning table 107, and a light pressure is applied to the sheet, and at the same time, the sheet aligning roller 106 is rotationally driven in the clockwise direction. Hit it. The first sheet S1 remains in place until post-processing, and the second sheet S2 is stacked on the first sheet S1 through the same process as the first sheet. The sheet alignment in the width direction (main scanning direction) is performed in a state where all the numbers of print processing sheets are in contact with the abutting portion 107a on the sheet alignment table 107. After both the width direction (main scanning direction) and the front-rear direction (sub-scanning direction) are aligned, post-processing such as stapling by a binding device (not shown) as a post-processing unit and punching by a punching device (not shown) is performed. After the post-processing, each sheet aligning roller 106 is driven to rotate counterclockwise, so that the printed sheets S are collectively discharged onto a post-processing discharge tray 113. In this case, the sheet printing surface and order are the same as those in the normal single-sided printing in the cylinder.

In the case of the above-described (4) which is the double-sided printing in which the post-processing is performed, the sheet S1 is fed from the sheet feeding cassette 20A which is in the state before the start shown in FIG. The fed first sheet S1 passes through the roller nip portion of the registration roller 13, the secondary transfer roller 12, and the fixing unit 14, and the sheet detection in which the rear end in the traveling direction of the first sheet S1 is a sheet discharge sensor. When the sensor 82 is passed, the switchback is started, passes through the double-sided path / re-transport path, passes through the paper discharge sensor again, and after the switchback is started, the feeding of the second sheet S2 is started.
When the first sheet S1 is conveyed via the duplex / post-processing path 72 and the sheet feeding / post-processing path 73 and passes the sheet detection sensor 110, the feeding of the third sheet S3 is started. The When the leading edge of the first sheet S1 reaches the sheet detection sensor 111, each sheet alignment roller 106 is separated from or separated from the sheet alignment table 107, and the trailing edge of the sheet movement direction is the sheet detection. When the sheet passes through the sensor 111, each sheet aligning roller 106 is driven in a direction to come into contact with the sheet aligning table 107, and a light pressure is applied to the sheet, and at the same time, the sheet aligning roller 106 is rotationally driven in the clockwise direction. Hit it. The first sheet S1 remains in place until post-processing, and the second sheet S2 is stacked on the first sheet S1 through the same process as the first sheet. The sheet alignment in the width direction (main scanning direction) is performed in a state where all the numbers of print processing sheets are in contact with the abutting portion 107a on the sheet alignment table 107. After both the width direction (main scanning direction) and the front-rear direction (sub-scanning direction) are aligned, post-processing such as stapling by a binding device (not shown) as a post-processing unit and punching by a punching device (not shown) is performed. After the post-processing, each sheet aligning roller 106 is driven to rotate counterclockwise, so that the printed sheets S are collectively discharged onto a post-processing discharge tray 113. In this case, the sheet printing surface and order are the same as those in the normal single-sided printing in the cylinder.

(Modification 1)
With reference to FIG. 28, the modification 1 of 1st Embodiment regarding the jam processing of the post-processing apparatus 100 is demonstrated.
The apparatus main body 1 is a desktop MFP as described above, is small, and the post-processing apparatus 100 of the first embodiment can be detached, that is, configured to be detachable from the apparatus main body 1. . Still, since the apparatus main body 1 is heavy and exists under the paper feed cassette 20A, separating the post-processing apparatus 100 for each jam processing generated in the post-processing apparatus 100 requires a great deal of labor for the user. To do.

  Therefore, as shown in FIG. 28, a post-processing path 108 which is a sheet conveyance path in the post-processing apparatus 100 in the same direction as the paper cassette 20A insertion / removal direction (arrow Xa and Xb direction) of the apparatus main body 1 which is a full front machine. A plurality of sheet aligning rollers 106 and a sheet aligning table 107 serving as a sheet aligning unit, and a binding device and a punching device (not illustrated) serving as a post-processing unit that performs post-processing are configured to be pulled out collectively. The post-processing path 108, the plurality of sheet aligning rollers 106, the sheet aligning table 107, a binding device and a punching device (not shown) are collectively held in a case 114 that forms a housing, and the case 114 is disposed in the post-processing device 100. It is held by a frame portion (not shown) as a support portion. Since the case 114 and the frame portion are slidably held by loose fitting in the form of rails, they can be inserted / removed / inserted / removed in one direction, in other words, separated. In addition, since the case 114 held by the frame is in a position that is weakly floated with respect to the installation base of the entire apparatus including the post-processing device 100, the bottom of the case 114 can be inserted and removed without using the installation base. The drive unit of the post-processing device 100 remains on the frame unit side, and the conveyance rollers 105, the sheet alignment rollers 106, the post-processing mechanism (not shown) and the punching device (not shown) are installed outside the case 114. It is the structure connected with the said drive part in a flame | frame with the other gear.

(Modification 2)
As described above, the post-processing device 100 can be added to answer various user requests. Therefore, in the second modification, as shown in FIG. 29, the post-processing apparatus 100A also has an extended paper discharge tray 120 that can be added by dividing the paper discharge tray section. The functions of the extended sheet discharge tray 120 include a large capacity stack function and a slide sort function.
As a configuration required for the additional installation, there is a release lever (not shown) so that the accompanying paper discharge tray 113A can be removed in the initial state of the post-processing device 100A, and the bottom surface of the post-processing device 100A and the top surface of the extended paper discharge tray 120 The same positioning means, power supply / feed terminals and signal terminals as in the option bank are used.

The present invention is not limited to the image forming apparatus of the above-described embodiment or modification, but is a monochrome copying machine, a monochrome laser printer, an inkjet printer, or a direct transfer in which a sheet is sequentially transferred and superimposed while being transferred by a transfer member. The present invention can be similarly applied to a tandem type color image forming apparatus. Needless to say, the endless belt-like photoconductor can be similarly applied to a single image forming apparatus. In particular, the in-cylinder discharge type image forming apparatus that is small and light in weight has the above-described remarkable effects.
The present invention has been described above with reference to specific embodiments. However, the technical scope disclosed by the present invention is not limited to those exemplified in the above-described embodiments, and may be configured by appropriately combining them. It will be apparent to those skilled in the art that various embodiments, modifications, and examples can be made within the scope of the present invention according to the necessity and application thereof.

1 is an external perspective view of an image forming apparatus to which the present invention is applied as viewed from the upper left side. FIG. 2 is a schematic longitudinal sectional view showing an example of the internal configuration of the image forming apparatus of FIG. 1 on the apparatus main body side. FIG. 2 is an external perspective view showing a state where an upper structure including an upper cover of the image forming apparatus in FIG. 1 is opened. (A) is a front view explaining a state when the scanner is slid to the end, and (b) is a front view explaining a state when the scanner is slid forward. It is a simplified front view showing an example in which the front cover can be opened and closed from the apparatus main body. It is a simplified front view of a paper feed cassette configured to be detachable from the apparatus main body and detachable. FIG. 2 is a schematic longitudinal sectional view illustrating an example of an internal configuration of an all-sheet passing path (sheet conveyance path) including a post-processing device mounted on the image forming apparatus according to the first embodiment, a sheet detection sensor, a branching claw, and the like. It is an expanded sectional view around a double-sided path and a branch claw. FIG. 6 is an enlarged cross-sectional view around a manual paper feed path and branch claws. It is an expanded sectional view around a double-sided / post-processing path, a paper feeding / post-processing path, and a branch claw. It is a perspective view around a double-sided / post-processing path, a paper feeding / post-processing path, and a branch claw. FIG. 6 is a bottom view of the sheet feeding cassette viewed from the back side. It is a simplified front view which shows the structure and operation | movement of a branch nail | claw and its drive part. It is a simplified front view which shows the structure and operation | movement of a branch nail | claw and its drive part. FIG. 6 is a perspective view of a manual sheet feeding unit. FIG. 5 is an enlarged cross-sectional view illustrating a sheet detection mechanism of a manual sheet feeding unit. It is an external appearance perspective view of the post-processing apparatus of FIG. FIG. 6 is a simplified front view illustrating a conveyance state before starting a sheet. FIG. 6 is a simplified front view illustrating a first sheet switchback and second sheet feeding start state of a sheet. FIG. 6 is a simplified front view illustrating a state in which the first sheet is conveyed to the post-processing apparatus inlet. It is a simplified front view showing a state before the first sheet is aligned by a sheet alignment roller. FIG. 6 is a simplified front view illustrating a state in which the first sheet is stopped at a sheet alignment position. FIG. 6 is a simplified front view illustrating a state in which the first sheet is stopped at a sheet alignment position. It is a simplified front view showing a state where the first sheet is in a double-sided printing resist position. It is a simple front view which shows the state which has the 2nd sheet | seat of a sheet | seat in a double-sided printing resist position. It is a simple front view which shows the state which has the 2nd sheet | seat of a sheet | seat in a double-sided printing resist position. It is a simplified front view showing a single-sided normal paper discharge state. It is an external appearance perspective view which shows that the support part and post-processing part of the post-processing apparatus of the modification 1 are comprised so that isolation | separation is possible. FIG. 10 is an external perspective view showing an extended sheet discharge tray of a post-processing apparatus according to Modification 1;

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Image formation part 10 Transfer apparatus 12 Secondary transfer roller 18 Upper cover (upper cover member)
20 Paper Feeder (Sheet Feeder)
20A paper feed cassette (sheet feed cassette)
24 Re-conveying path (constitutes the second sheet conveying path)
25 Paper discharge roller pair (composed of sheet discharge unit, switchback means)
30 Image Reading Unit, Scanner 40 Sheet Stacking Unit 41 Sheet Stacking Surface 45 Manual Feed Unit (Manual Feed Unit)
46 Manual feed slot (manual feed slot)
50 Supporting part 67 Single-sided conveyance path (first sheet conveyance path)
71 Double-sided conveyance path (constitutes the second sheet conveyance path)
72 Double-sided / post-processing path (sheet transport path)
73 Paper Feed / Post-Processing Path (Sheet Conveyance Path)
74 Manual feed path (sheet transport path)
90 branch claw (conveying direction switching means)
95 Solenoid (conveying direction switching means drive unit)
96 links (conveying direction switching means drive unit)
97 Tension spring (constitutes the drive unit for the transfer direction switching means)
100, 100A Post-processing device 101a, 101b, 101c Positioning boss (Positioning means of post-processing device)
102 Feeding terminal (feeding means of post-processing device)
103 Signal terminal (Signal communication means of post-processing device)
106 Sheet alignment roller (constitutes the sheet alignment section)
107 Sheet alignment table (configures the sheet alignment section)
109 Sheet detection sensor (sheet detection means of manual feed unit)
112 Filler (Detection mechanism of manual feeding unit)
113 Paper discharge tray (sheet storage means)
S sheet (sheet-shaped recording medium)
Xa Sheet discharge direction (paper discharge direction), slide direction Y Sheet width direction

Claims (8)

A sheet feeding unit that is detachable with respect to the apparatus body, and that feeds sheets from the sheet feeding cassette ;
An image forming unit that is disposed above the sheet feeding unit and forms an image on the sheet fed from the sheet feeding unit;
A first sheet conveyance path for guiding the fed sheet so as to contact the image forming unit;
A sheet discharge portion for exiting exhaust to the rear side of the sheet with the image formed from the apparatus main body front, a sheet with a switchback means for switchback first sheet conveying path as the image forming unit,
A sheet stacking unit that is disposed at an upper portion of the image forming unit and stacks an image-formed sheet discharged from the sheet discharge unit in a sheet discharge direction;
It is a conveyance path different from the first sheet conveyance path, and after the image-formed sheet that has been switched back by the switchback means is reversed, it passes through a part of the sheet feeding unit, and the first sheet again. A second sheet conveying path that forms an image on the other sheet surface of the sheet by contacting the image forming unit,
It is arranged at the bottom of the sheet feeding unit so as to be able to receive a sheet conveyed in the direction of the bottom of the sheet feeding unit from the middle of the second sheet conveyance path, and is configured to be detachable from the apparatus main body. After- treatment device,
I have a,
A sheet feeding port for sheets fed from the sheet feeding cassette, a secondary transfer unit disposed in the image forming unit, and a sheet ejected image from the sheet discharging unit to the sheet stacking unit. The paper discharge port is disposed in this order from the bottom to the top of the front of the apparatus body,
The second sheet conveying path is formed to be curved so as to communicate with the sheet feeding port from the sheet discharge port, and the lowest point of the second sheet conveyance path is disposed in the vicinity of the lowermost surface of the apparatus main body. Has been
A sheet feeding / post-processing path that branches off from the vicinity of the lowest point of the second sheet conveying path and communicates with the post-processing apparatus is provided;
The apparatus main body is further provided with a sheet feeding cassette that can be inserted into and removed from the apparatus main body.
An image forming apparatus , wherein positioning means of the post-processing apparatus with respect to the apparatus main body has the same configuration as positioning means of the sheet feeding cassette to be added . The image forming apparatus according to claim 1 .
An image forming apparatus , wherein power supply means of the post-processing apparatus for the apparatus main body has the same configuration as power supply means of the sheet feeding cassette to be added . The image forming apparatus according to claim 1 or 2,
The image forming apparatus according to claim 1, wherein the signal communication means of the post-processing apparatus for the apparatus main body has the same configuration as the signal means of the sheet feeding cassette to be added . The image forming apparatus according to any one of claims 1 to 3 ,
An image forming apparatus comprising: a conveyance direction switching unit capable of switching a sheet conveyance direction in the middle of a second sheet conveyance path in the sheet feeding unit. The image forming apparatus according to any one of claims 1 to 4,
An image forming apparatus comprising: a drive unit for the transport direction switching unit in the post-processing apparatus. The image forming apparatus according to claim 1,
In the apparatus main body, a manual feeding unit is arranged,
An image forming apparatus , comprising: a detection mechanism including a sheet detection unit configured to detect a sheet feeding state from the manual feeding unit in the post-processing apparatus. The image forming apparatus according to any one of claims 1 to 6,
The post-processing apparatus has a sheet conveyance path, a sheet aligning unit, and a post-processing unit,
An image forming apparatus , wherein the post-processing section and the support section of the post-processing apparatus are configured to be separable . The image forming apparatus according to any one of claims 1 to 7,
The post-processing apparatus has a sheet storage means for storing a post-processed sheet,
The sheet storage means is configured to be detachable from the post-processing apparatus main body, and an expanded sheet storage means is attached to the bottom of the post-processing apparatus main body after being detached from the post-processing apparatus main body. An image forming apparatus capable of being used.

Images