JP5157421B2 - Image forming apparatus and post-processing apparatus - Google Patents

Description

The present invention is a copying machine, a facsimile, a printer, to a processing device after there use in an image forming apparatus and the image forming apparatus such as MFP.

  In image forming apparatuses such as copiers, facsimiles, printers, and multifunction machines of these, as described in [Patent Document 1] to [Patent Document 5], generally, an image forming paper or the like is used. A sheet is placed in a substantially horizontal direction, and the sheet is fed out in a substantially horizontal direction to form an image, and a sheet such as a sheet on which an image has been formed is discharged out of the main body of the image forming apparatus in a substantially horizontal direction. Therefore, the sheet discharge direction and the sheet feeding direction are parallel to each other, but these directions are the same in the image forming apparatuses described in [Patent Document 1] and [Patent Document 2]. 3] to [Patent Document 5], the image forming apparatuses are opposite to each other.

  On the other hand, the image forming apparatus is provided with a paper feed cassette for placing a plurality of sheets. The paper feed cassette is provided so as to be able to be pulled out from the image forming apparatus main body. The seat can be replenished. In order to facilitate the operation of pulling out the sheet cassette and the sheet replenishment operation, the sheet cassette is normally drawn in the direction of the front or side of the image forming apparatus. Since the ease of such work affects the usability of the image forming apparatus, it is important which direction the paper cassette is pulled out.

  Another factor that affects the usability of the image forming apparatus is the ease of taking out the sheet discharged outside the image forming apparatus main body. Therefore, it is necessary to determine the discharge direction of the sheet outside the image forming apparatus main body so that the sheet can be easily taken out.

  Under such circumstances, the drawing direction of the sheet feeding cassette, the feeding direction of the sheet from the sheet feeding cassette, and the discharging direction of the sheet from the image forming apparatus main body are determined in consideration of these workability.

  In consideration of prevention of sheet jamming in the image forming apparatus and simplification of the structure of the image forming apparatus, it is better that the sheet conveyance path in the image forming apparatus is simple. From this point of view, the sheet conveyance path in the image forming apparatus is S-shaped, and the sheet conveyance path in the image forming apparatus is more coherent than the image forming apparatuses described in [Patent Document 1] and [Patent Document 2]. The image forming apparatus described in the character-shaped [Patent Document 3] to [Patent Document 5] is more preferable.

  However, for example, as in the image forming apparatuses described in [Patent Document 3] to [Patent Document 5], the sheet transport path in the image forming apparatus is formed in a U-shape. If you try to determine the paper cassette withdrawal direction, the sheet feeding direction from the paper cassette, the sheet ejection direction from the main body of the image forming apparatus, and other layouts, all these conditions will be satisfied. There are cases where it cannot be satisfied. In particular, in an image forming apparatus, it is naturally necessary to form an image on a sheet that is being conveyed through the inside of the image forming apparatus. For this reason, the sheet discharge direction may be inevitably reduced in the sheet take-out property. Such a situation also occurs in the image forming apparatus described in [Patent Document 1] and [Patent Document 2] in which the sheet conveyance path in the image forming apparatus is S-shaped.

  In addition, from the viewpoint of common parts, a layout in which only the sheet discharge direction is reversed may be required in order to provide variations in the sheet extraction direction while sharing the internal structure of the image forming apparatus.

  Here, post-processing apparatuses such as those described in [Patent Document 1] to [Patent Document 4] are known as those that perform various processes on an image-formed sheet while sharing the internal structure of the image forming apparatus. It has been.

JP 2004-334040 A JP 2005-348065 A Japanese Patent No. 3795488 JP 2000-86076 A JP 11-65195 A

  However, none of the post-processing apparatuses discharges the sheet that has been discharged from the main body of the image forming apparatus by reversing the traveling direction. Although the image forming apparatus described in [Patent Document 5] can increase the number of paper discharge trays, it does not disclose a technique for reversing the sheet traveling direction.

  In recent years, there has been an increasing demand for space saving of installation of the image forming apparatus, that is, suppression of the installation area. However, any of the post-processing apparatuses described in [Patent Document 2] to [Patent Document 4] Since it is arranged on the side of the apparatus main body and causes an increase in the installation area, it does not sufficiently meet such requirements.

  Considering these circumstances comprehensively, the image forming apparatus main body, in other words, by reversing the traveling direction of the image-formed sheet discharged from the original discharge position of the image forming unit that performs image formation on the sheet. Development of technologies for discharging, in particular, technologies for performing such discharging while preventing or suppressing an increase in the installation area is awaited.

  Furthermore, development of an image forming apparatus capable of performing post-processing on an image-formed sheet whose traveling direction is reversed while preventing or suppressing an increase in installation area is awaited.

The present invention includes a sheet reversing device that reverses an image-formed sheet, and reverses and discharges the traveling direction of the image-formed sheet while preventing or suppressing an increase in installation area. Image forming apparatus such as a copying machine, a facsimile, a printer, and a composite machine capable of performing predetermined post-processing on the inverted image-formed sheet, and an installation area used for the image forming apparatus It is an object of the present invention to provide a post-processing apparatus that performs a predetermined post-processing on a sheet on which an image has been formed whose direction of travel is reversed while preventing or suppressing the increase of the image.

To achieve the above object, a first aspect of the present invention, an image forming unit for forming an image on a sheet, accept imaged sheet, the front side of reversing the traveling direction of the sheet the image forming apparatus a sheet reversing apparatus having a sheet reversing portion for discharging the performs predetermined post-processing on the sheet that has passed through the sheet inverting portion, selectable from a plurality of types having different functions, removably attached to the image forming apparatus A guide unit that guides the post-processing unit when the post-processing unit is mounted on the image forming apparatus, and the sheet reversing unit passes through the first part that receives and conveys the sheet, and the first part. A second portion that reverses the traveling direction of the sheet, and a first conveyance path that guides the sheet that has passed through the second portion toward the front side to the post-processing unit that is positioned above the first portion. The second part The sheet passing through is discharged toward the front side above the same post-processing unit without leading to the post-processing unit, it has a second transport path located above the first portion, the sheet A reversing unit is provided above or below the image forming unit, and the post-processing unit is provided on the side where the sheet reversing unit is provided above or below the image forming unit by the guide unit. The image forming apparatus can be attached to the image forming apparatus at the same time so as to be connected to each other in any order from the back side to the front side of the image forming apparatus, and is driven by a driving source provided in the sheet reversing unit. As described above, at least the back side and the near side have a drive gear train having a common layout, and the plurality of post-processing units in the state are provided in each of the post-processing units. From the back side By being connected to each other toward the front side, the sheet is driven from the back side while being driven by the drive source and maintaining the traveling direction of the sheet discharged from the first transport path on the front side. Inheriting and transporting toward the front side, performing a predetermined post-processing on the sheet in the process of transporting to the front side, from the post-processing unit on the most front side among the plurality of the post-processing unit The sheet is discharged to the front side, and the upper surface of the sheet is in an image forming apparatus that forms a discharge tray on which the sheets discharged to the front side by the second transport path are stacked .

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the sheet reversing device is detachable .

According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect of the present invention, a document reading unit that reads a document image is provided, and the document reading unit is disposed above the sheet reversing unit and the image forming unit. It is characterized by being provided in.

According to a fourth aspect of the present invention, there is provided a post-processing apparatus including the post-processing unit used in the image forming apparatus according to any one of the first to third aspects and having the driving gear train having the common layout .

According to a fifth aspect of the present invention, in the post-processing apparatus according to the fourth aspect , an electrical connection section for connecting to the other post-processing section is compatible with each other.

According to a sixth aspect of the present invention, in the post-processing apparatus according to the fourth or fifth aspect , there is provided an electrical path wiring for the other post-processing section.

The present invention relates to a sheet reversing unit including an image forming unit that forms an image on a sheet, and a sheet reversing unit that receives an image-formed sheet, reverses the traveling direction of the sheet, and discharges the sheet to the front side of the image forming apparatus. A post-processing section that is detachable from the image forming apparatus and that can be selected from a plurality of types having different functions, and that performs predetermined post-processing on the sheet that has passed through the apparatus and the sheet reversing section. And a sheet reversing unit that receives and conveys the sheet, and a second portion that reverses the traveling direction of the sheet that has passed through the first portion. A first conveyance path that guides the part, the sheet that has passed through the second part, to the post-processing unit positioned above the first part, and the sheet that has passed through the second part. Lead to the post-processing section Discharged toward the front side above the same post-processing unit without, and a second transport path located above the first portion possess, the sheet inverting portion above or below the image forming unit The plurality of post-processing units are arranged on the side where the sheet reversing unit is provided above or below the image forming unit by the guide unit, from the back side to the near side of the image forming apparatus. Can be attached to the image forming apparatus at the same time so as to be connected to each other in any order, and at least the back side and the near side are driven by a driving source provided in the sheet reversing unit. A plurality of the post-processing units in the state, the driving gear trains provided in the respective post-processing units are directed from the back side toward the front side. Connected to each other The sheet is driven by the driving source and is conveyed from the back side to the front side while maintaining the traveling direction of the sheet discharged from the first transport path on the near side, Predetermined post-processing is performed on the sheet in the course of conveyance toward the front side, and the sheet is discharged from the front-side post-processing unit closest to the front side to the front side among the plurality of the post-processing units. In addition, since the upper surface of the image forming apparatus forms a discharge tray on which the sheets discharged to the front side by the second transport path are stacked , the increase in the installation area and the increase in the number of parts can be prevented or suppressed. However, it is possible to eject the image-formed sheet on the upper surface of the post-processing unit without performing post-processing by reversing the traveling direction, and arranging a plurality of post-processing units selected as necessary. Care The sheet can be easily mounted without operability, and the operability is good, and a plurality of predetermined post-processing can be performed on the image-formed sheet by the plurality of mounted post-processing units. It is possible to provide an image forming apparatus that can reduce the weight and size of the processing unit itself without providing a driving source, and can improve sheet take-out performance.

  If a document reading unit for reading a document image is provided, and this document reading unit is provided above the sheet reversing unit and the image forming unit, the installation area of the document reading unit can be reduced. While preventing or suppressing the increase, the image-formed sheet can be discharged while being reversed, and the image-formed sheet can be subjected to predetermined post-processing, and the sheet can be taken out. It is possible to provide an image forming apparatus capable of improving the performance.

  If the electrical connection section for connecting to the other post-processing section is compatible with each type, the direction of travel is reversed by selecting the desired function type and mounting it on the image forming apparatus. Post-processing with the same function can be performed on the discharged sheets, and when mounting a plurality of sheets on the image forming apparatus, the mounting operation can be performed without worrying about the arrangement, and wiring is simplified. Therefore, it is possible to provide a post-processing apparatus that can contribute to the provision of an image forming apparatus that has excellent appearance and high usability.

  If it has wiring for the electrical path for the other post-processing units, it is possible to select the desired function type and attach it to the image forming apparatus, thereby reversing the direction of travel to the discharged sheet. On the other hand, it is possible to provide a post-processing apparatus that can perform post-processing by the same function and that can contribute to the provision of an image forming apparatus that has excellent appearance and high usability because the wiring is simplified. .

  FIG. 1 shows an outline of the appearance of an image forming apparatus that is a multicolor image forming apparatus capable of forming a color image to which the present invention is applied. The image forming apparatus 100 is a color laser copying machine, which is a combination machine of a color laser printer and a facsimile, but other types of copying machines, other types of printers, facsimiles, combinations of such copying machines and such printers. Other image forming apparatuses such as a printer may be used. The image forming apparatus 100 can use any of ordinary paper generally used for copying and the like, a resin film such as an OHP sheet, thick paper such as a card and a postcard, and an envelope as a sheet used for image formation. It is.

  As shown in FIG. 1 or 2, the image forming apparatus 100 includes a main body 99 as an image forming unit that forms an image on a transfer sheet as a sheet that occupies a central position from the bottom in the vertical direction, and a lower side of the main body 99. A sheet feeding device 61 serving as a sheet feeding unit that is positioned and loads transfer sheets on which image formation is performed in the main body 99 and feeds the loaded transfer sheets to the main body 99 is provided. The transfer paper is not shown.

  The image forming apparatus 100 is also located on the upper side of the main body 99, and is a detachable rear part as a post-processing unit that is a plurality of sheet post-processing units that perform predetermined post-processing on transfer paper on which image formation has been performed in the main body 99. It includes processing devices 31, 32, and 33, and a relay unit 41 that is positioned above the main body 99 and receives transfer paper on which an image has been formed in the main body 99 and guides it to the post-processing device 31.

  The image forming apparatus 100 is also positioned above the main body 99, the post-processing devices 31, 32, 33 and the relay unit 41, a reading device 21 as a scanner for reading a document, and a reading device 21 positioned above the reading device 21 and loaded with a document. It has an automatic document feeder 22 called ADF that feeds the stacked documents toward the reading device 21. The reading device 21 and the automatic document feeder 22 constitute an image reading unit 23 as a document reading unit that reads an image recorded on a document.

  The image forming apparatus 100 is also detachably disposed on the post-processing device 33 and is a transfer paper that passes the post-processing devices 31, 32, and 33 and on which the transfer paper passes the relay unit 41. Disposed on the upper surface of the relay unit 41 and the discharge tray 25 constituted by the upper surfaces of the post-processing devices 31, 32, 33, on which the transfer paper discharged without being guided to the processing devices 31, 32, 33 is discharged. When the post-processing devices 31, 32, and 33 are mounted, the post-processing devices 31, 32, and 33 are guided, and a guide portion 26 is provided as a guide unit that is fixed to the image forming apparatus 100.

  The image forming apparatus 100 is also arranged on the upper surface of the main body 99 on the front side of the image forming apparatus 100 indicated by the arrow D1, in other words, on the front side. And a control unit (not shown) as control means for controlling the overall operation and the like of the image forming apparatus 100. An arrow D2 indicates a direction facing the back side of the image forming apparatus 100. The direction D1 and the direction D2 are parallel to each other and are opposite to each other, and are substantially parallel to the mounting surface of the image forming apparatus 100.

  In the layout of the image forming apparatus 100, the image reading unit 23 is positioned above the main body 99 and the relay unit 41, so that the operability is improved and the installation area is suppressed. In addition to this, the relay unit 41 is located above the main body 99, and the post-processing devices 31, 32, and 33 are located above the main body 99 and the relay unit 41 also contribute to the suppression of the installation area. doing. In addition to this, the fact that most of the paper discharge tray 24 and the whole paper discharge tray 25 are located above the main body 99 also contributes to the reduction of the installation area. The main body 99, the relay unit 41, and the image reading unit 23 are integrated and cannot be separated.

Details of the main body 99 will be described with reference to FIG.
As shown in the figure, the main body 99 is a latent image carrier as a plurality of image carriers that can form images as images corresponding to colors separated into yellow, magenta, cyan, and black, respectively. A tandem structure employing a tandem structure in which certain cylindrical photosensitive drums 20Y, 20M, 20C, and 20BK are arranged side by side is employed, and the image forming apparatus 100 is a tandem type, that is, a tandem type image forming apparatus. .

  The photosensitive drums 20Y, 20M, 20C, and 20BK have the same diameter, and are transfer images that are intermediate transfer belts as intermediate transfer members that are endless belts that are disposed almost in the center of the main body 99 of the image forming apparatus 100. They are arranged at equal intervals on the outer peripheral surface side of the belt 11, that is, on the image forming surface side.

  The photosensitive drums 20Y, 20M, 20C, and 20BK are arranged in this order from the upstream side in the A1 direction. The photoconductive drums 20Y, 20M, 20C, and 20BK are image stations 60Y, 60M, 60C, and 60BK that are image forming units as image forming units for forming yellow, magenta, cyan, and black images, respectively. Is provided.

  The transfer belt 11 is movable in the direction of the arrow A1 while facing the photosensitive drums 20Y, 20M, 20C, and 20BK. The visible image, that is, the toner image formed on each of the photoconductive drums 20Y, 20M, 20C, and 20BK is superimposed and transferred onto the transfer belt 11 that moves in the direction of the arrow A1, and is then collectively transferred onto the transfer paper. It has become.

  In the superimposing transfer to the transfer belt 11, the toner images formed on the photosensitive drums 20Y, 20M, 20C, and 20BK are transferred to the same position on the transfer belt 11 while the transfer belt 11 moves in the A1 direction. As described above, voltage is applied by primary transfer rollers 12Y, 12M, 12C, and 12BK as transfer chargers disposed at positions facing the respective photosensitive drums 20Y, 20M, 20C, and 20BK across the transfer belt 11. , The timing is shifted from the upstream side toward the downstream side in the A1 direction, and the transfer is performed at a transfer position that is opposite to each of the photosensitive drums 20Y, 20M, 20C, and 20BK and the transfer belt 11.

  The transfer belt 11 is an elastic belt whose entire layer is formed using an elastic member such as a rubber agent. The transfer belt 11 may be a single-layer elastic belt, may be an elastic belt using a part of the elastic belt, or a conventionally used fluorine-based resin, polycarbonate resin, or polyimide resin. Or an inelastic belt may be used.

  The image forming apparatus 100 is an intermediate transfer apparatus that includes four image stations 60Y, 60M, 60C, and 60BK, and is disposed below the photosensitive drums 20Y, 20M, 20C, and 20BK, and includes a transfer belt 11. A transfer belt unit 10 as a certain belt unit, and a transfer member that is disposed opposite to the transfer belt 11 and contacts the transfer belt 11 and rotates in the same direction as the transfer belt 11 at the contact position with the transfer belt 11. And a secondary transfer roller 5 as a transfer device which is a paper transfer belt.

  The image forming apparatus 100 also includes a cleaning device 34 as an intermediate transfer belt cleaning device that is disposed opposite to the transfer belt 11 and includes an intermediate transfer cleaning blade that cleans the transfer belt 11, and image stations 60Y, 60M, and 60C. , And an optical scanning device 8 as a writing device as an optical writing device, which is a writing means disposed facing the upper side of 60BK.

  The image forming apparatus 100 is also transported from the sheet feeding device 61, a sheet feeding device 61 on which transfer paper transported between the photosensitive drums 20 </ b> Y, 20 </ b> M, 20 </ b> C, 20 </ b> BK and the transfer belt 11 is stacked. A pair of registration rollers that feeds the recording paper to the transfer portion between the transfer belt 11 and the secondary transfer roller 5 at a predetermined timing in accordance with the timing of toner image formation by the image stations 60Y, 60M, 60C, and 60BK. 13 and a sensor (not shown) for detecting that the leading edge of the transfer paper has reached the registration roller pair 13.

  The image forming apparatus 100 also includes a fixing device 6 as a roller fixing type fixing unit for fixing the toner image onto the transfer paper that has entered the toner image after being transferred and conveyed in the direction of arrow C1, and a fixing device. 6 is discharged to the outside of the main body 99, and the transfer paper is disposed in the upper part of the main body 99 and is discharged to the outside of the main body 99 in the direction D2. It has a discharge port 17 through which paper enters the relay unit 41 and a toner bottle (not shown) filled with toners of each color of yellow, magenta, cyan, and black.

  In addition to the transfer belt 11, the transfer belt unit 10 includes primary transfer rollers 12Y, 12M, 12C, and 12BK, and a driving roller that is a driving member as a plurality of winding members around which the transfer belt 11 is wound. It has a transfer entrance roller 73 which is also a supporting roller and a driven roller 72 which is a supporting roller. The transfer entrance roller 73 is driven to rotate by driving a motor as a drive source (not shown), whereby the transfer belt 11 is driven to rotate in the A1 direction.

  The fixing device 6 includes a fixing roller 62 having a heat source therein and a pressure roller 63 pressed against the fixing roller 62, and transfers the transfer paper carrying the toner image to the fixing roller 62 and the pressure roller 63. By passing the toner image through a fixing unit that is a pressure contact portion, the carried toner image is fixed on the surface of the transfer paper by the action of heat and pressure.

  The optical scanning device 8 is an LSU, and scans and exposes scanning surfaces formed by the surfaces of the photosensitive drums 20Y, 20M, 20C, and 20BK, and forms image signals for forming an electrostatic latent image. Beams LY, LM, LC, and LBK are emitted as laser beams based on the above. The beams LY, LM, LC, and LBK are emitted according to image information based on the image to be formed.

  The sheet feeding device 61 includes a paper feed tray 15 on which transfer paper is stacked, a paper feed roller 16 that feeds the transfer paper stacked on the paper feed tray 15, and a paper feed roller 16 that is disposed opposite the paper feed roller 16 to double feed the transfer paper. In this case, there is provided a friction pad 29 as a separating means for separating the sheet into one sheet and a sheet feeding tray 15 that can be pulled out from the main body 99 in the direction of arrow D1 and can be further removed from the pulled-out state. It has a paper feed cassette 14 as a body and a transport path 35 used when forming double-sided images.

  Since the paper feed cassette 14 can be pulled out in the direction D1, that is, the front side of the image forming apparatus 100, an operation of supplying transfer paper to the paper feed cassette 14 is easily performed. When the paper feed cassette 14 is pulled out, the friction pad 29 and a part of the re-transport path 35 are pulled out together with the paper feed cassette 14, but the paper feed roller 16 is held at a fixed position without moving.

  The secondary transfer roller 5 forms a part of the main body 99 and can be opened in the direction of the arrow F1 together with the front cover 28 positioned on the front surface side of the image forming apparatus 100. If this is the case, this can be easily resolved.

  Regarding the image stations 60Y, 60M, 60C, and 60BK, the configuration will be described as a representative of the configuration of the image station 60Y including the photosensitive drum 20Y. Since the configuration of the other image station is substantially the same, in the following description, for the sake of convenience, a reference numeral corresponding to the reference symbol assigned to the configuration of the image station 60Y is attached to the configuration of the other image station. Further, detailed description will be omitted as appropriate, and those with Y, M, C, and K at the end of the reference numerals are configurations for forming yellow, magenta, cyan, and black images, respectively. Will be shown.

  The image station 60Y provided with the photoconductive drum 20Y is for cleaning the primary transfer roller 12Y and the photoconductive drum 20Y around the photoconductive drum 20Y along its rotation direction B1, which is the clockwise direction in the drawing. A cleaning device 70Y as a cleaning device, a charging device 30Y as a charging device as a charging device for charging the photosensitive drum 20Y to a high voltage, and a developing device as a developing device for developing the photosensitive drum 20Y A developing device 50Y. The developing device 50Y has a developing roller 51Y disposed at a position facing the photosensitive drum 20Y.

  The photosensitive drum 20Y, the cleaning device 70Y, the charging device 30Y, and the developing device 50Y are integrated to form a process cartridge. The process cartridge is detachable from the main body 99. Making a process cartridge in this way is very preferable because it can be handled as a replacement part, so that the maintainability is remarkably improved.

  With the configuration described above, the surface of the photosensitive drum 20Y is uniformly charged to a predetermined polarity by the charging device 30Y as it rotates in the B1 direction, and yellow is detected by exposure scanning of the beam LY from the optical scanning device 8. An electrostatic latent image corresponding to the color is formed. The electrostatic latent image is formed by scanning the beam LY in the main scanning direction, which is a direction perpendicular to the paper surface, and performing sub scanning in the circumferential direction of the photosensitive drum 20Y by rotating the photosensitive drum 20Y in the B1 direction. This is done by scanning in the direction as well.

  To the electrostatic latent image formed in this manner, charged yellow toner supplied by the developing device 50Y adheres, and is developed into a yellow color to be visualized. The toner image, which is a visible image, is primarily transferred to the transfer belt 11 moving in the A1 direction by the primary transfer roller 12Y, and foreign matters such as toner remaining after the transfer are scraped off and stored by the cleaning device 70Y. The drum 20Y is subjected to the next charging by the charging device 30Y.

  Similarly, toner images of the respective colors are formed on the other photosensitive drums 20C, 20M, and 20BK, and the formed toner images of the respective colors are transferred to the A1 direction by the primary transfer rollers 12C, 12M, and 12BK. 11 is sequentially transferred to the same position on the head.

  The toner image superimposed on the transfer belt 11 moves to the transfer portion that is the secondary transfer portion that is the position facing the secondary transfer roller 5 as the transfer belt 11 rotates in the A1 direction. Secondary transferred onto transfer paper.

  The transfer paper conveyed between the transfer belt 11 and the secondary transfer roller 5 is fed out from the sheet feeding device 61 and aligned with the leading edge of the pair of resist rollers 13 being stopped. Based on the detection signal, the registration roller pair 13 is rotated, and the toner image on the transfer belt 11 is sent out at the timing when the front end of the toner image faces the secondary transfer roller 5.

  When the toner images of all colors are collectively transferred and carried on the transfer paper, the transfer paper is transported in the C1 direction and enters the fixing device 6, and passes through the fixing portion between the fixing roller 62 and the pressure roller 63. The carried toner image is fixed by the action of heat and pressure, and this fixing process forms a color image as a composite color image on the transfer paper. The fixed transfer paper that has passed through the fixing device 6 passes through the paper discharge roller 7 and is discharged from the discharge port 17 toward the relay unit 41. On the other hand, the transfer belt 11 that has finished the secondary transfer is cleaned by the cleaning device 34 to prepare for the next primary transfer.

  In the main body 99, the transfer paper is fed out in the direction D1, and image formation is performed in the process of being conveyed upward, and is discharged in the direction D2. In this way, the transfer paper is transported in a substantially U-shape within the main body 99, so the transfer paper transport path has a relatively simple U-shape, which is less likely to jam. There is an advantage that the time from paper supply to paper discharge is short and image formation is performed promptly.

The configuration of the image reading unit 23 will be described.
The reading device 21 includes a contact glass (not shown) for placing a document, a light source (not shown) that irradiates light on the document placed on the contact glass, and a first light (not shown) that reflects light reflected from the light source. A first traveling body (not shown) that includes a reflector and travels in the left-right direction in FIG. 2, a second traveling body that includes a second reflector (not illustrated) that reflects light reflected by the reflector of the first traveling body, (2) An imaging lens (not shown) for imaging light from the traveling body, a reading sensor (not shown) that receives the light passing through the imaging lens and reads the contents of the document are provided.

  The automatic document feeder 22 is pivotally integrated with the reading device 21 and can be opened and closed with respect to the reading device 21. The automatic document feeding device 22 is opened with respect to the reading device 21 by rotating upward to expose the contact glass. Let

As shown in FIG. 1, the automatic document feeder 22 feeds a document table 22a on which a document is placed, a platen cover 22b that presses the document against a contact glass, and a document placed on the document table 22a. And a drive unit having a motor or the like (not shown). When copying using the image forming apparatus 100, the document is set on the document table 22a of the automatic document feeder 22, or the automatic document feeder 22 is rotated upward and manually placed on the contact glass. After placing the document, the automatic document feeder 22 is closed and the document is pressed against the contact glass by the platen cover 22b.
When the image forming apparatus 100 is used as a printer or a facsimile, the image forming apparatus 100 performs image forming processing based on an image signal corresponding to image information received from the outside.

  As shown in FIG. 2, the relay unit 41 is disposed at a position facing the discharge port 17, and receives the image-formed transfer paper discharged from the discharge port 17, and the direction D <b> 2 from the reception port 42. And a sheet reversing path 43 for reversing the traveling direction of the transfer paper entering the direction D1 in the direction D1 and discharging it to the outside of the relay unit 41.

  The relay unit 41 also branches from the sheet reversing path 43, and discharges the transfer paper that has passed through the sheet reversing path 43 toward the post-processing apparatus 31, thereby serving as a first transport path that leads to the post-processing apparatus 31. As a second transport path for guiding the transfer paper that has passed through the discharge path 44 and the sheet reversing path 43 to the discharge tray 25 positioned above the post-processing devices 31, 32, and 33, and leading to the discharge tray 25. Second discharge path 46.

  The relay unit 41 is also disposed at a position facing the post-processing device 31, and is directed to a first discharge port 45 through which the transfer paper that has passed through the first discharge path 44 enters the post-processing device 31, and the discharge tray 25. The second discharge port 47 for discharging the transfer paper that has been opened and passed through the second discharge path 46 onto the discharge tray 25, and the first discharge path 44 and the second discharge of the transfer paper that has passed through the sheet reversing path 43. A switching claw 48 for switching which path 46 is entered and a plurality of roller pairs 49 for conveying the transfer paper in the relay unit 41 are provided.

  As shown in FIG. 1, the guide portion 26 extends along the directions D <b> 1 and D <b> 2 and is paired with a pair of recesses that fit into the protrusions 28 protruding from the lower surfaces of the post-processing devices 31, 32, and 33. 29, the post-processing devices 31, 32, 33 can be moved in such a manner as to slide only in the directions D 1, D 2 with the protrusion 28 fitted in the recess 28. . The order of mounting is arbitrary. Therefore, the post-processing devices 31, 32, and 33 are easily mounted without making a mistake in the mounting position, and the workability of the mounting work is improved.

  Although illustration is omitted, the operation panel 27 selects a copy start key for starting copying, a numeric keypad for designating the number of copies, and any of the attached post-processing devices 31, 32, 33 to be operated. Has keys etc.

  Although not shown, the control unit includes a CPU, a memory, and the like. For example, driving of the switching claw 48 of the relay unit 41 and operations described later of the post-processing devices 31, 32, and 33 are input to the operation panel 27. Based on the control.

  The post-processing devices 31, 32, and 33 transport the transfer paper in this order while maintaining the transport direction of the transfer paper that has passed through the sheet reversing path 43 in the direction D <b> 2. The stamp stamp, the staple binding, and the 1 bin sort are performed, and the transfer paper is discharged to the front side of the image forming apparatus 100.

  As shown in FIG. 4, the post-processing devices 31, 32, and 33 are compatible with each other, such as an electrical connection unit 34 for connecting to other post-processing units. The shapes and the like of the respective housings 35 are made common, so that the order of connection in the directions D1 and D2 is arbitrary. Therefore, mounting of the post-processing devices 31, 32, and 33 is easily performed without considering the order of connection. 4A is a plan view of the post-processing devices 31, 32, and 33, and FIG. 4B is a rear view of the post-processing devices 31, 32, and 33. FIG.

  In order to make the connecting order of the post-processing devices 31, 32, 33 arbitrary in the directions D 1, D 2, the electrical connection parts 34 are respectively arranged on the direction D 2 side, that is, on the back side of the housing 35 in the mounted state on the image forming layer 100. The connector projections 36 of the same configuration projecting at the same position and the connector projections 36 recessed at the same position on the direction D1 side, that is, the front side of the housing 35 in the mounted state on the image forming layer 100 are fitted. Connector recesses 37 having the same configuration. Correspondingly, on the direction D1 side of the relay unit 41, a connector recess (not shown) having the same configuration as the connector recess 37 is disposed at a position where it is fitted with the connector protrusion 36, and the relay unit 41 is located closest to the direction D2. It fits with the connector projection 36 of the mounted post-processing device. The connector recesses of the electrical connection portions 34 and the relay unit 41 have the same power supply line and ground line in the same manner as can be seen from FIG. 5B, and are mounted on the direction D1 side. It is configured such that power can be supplied to other post-processing devices.

  As a result, the wiring of each of the post-processing devices 31, 32, and 33 is simplified, it is easy to use such as a clean appearance and does not catch on the harness, and the relay unit regardless of the order of connection in the directions D1 and D2. Only one connector recess provided in 41 is supplied with power corresponding to a plurality of post-processing apparatuses, and the configuration is simplified.

  In addition, the wiring addresses in each electrical connection section 34 are allocated to each of the post-processing devices 31, 32, and 33, and the signal line 38 disposed in each of the post-processing devices 31, 32, and 33 Only those used in the processing apparatus are drawn from the connector projection 36, and the others are directly connected to the connector recess 37 from the connector projection 36 through the through-pass. That is, the signal line 38 has wiring for an electrical path for other post-processing devices. Accordingly, control signals for the post-processing devices 31, 32, and 33 can be transmitted and received regardless of the order of connection in the directions D1 and D2, and each of the post-processing devices 31, 32, and 33 is connected to the image forming apparatus 100 by a harness. There is no need to perform wiring, and wiring is performed simply and easily.

  In order to obtain the driving force necessary for the operation of each post-processing device 31, 32, 33 even if the order of connection of the post-processing devices 31, 32, 33 is arbitrary in the directions D1, D2, each post-processing device 31 is provided. , 32 and 33 have a drive gear train 39 having a common layout at least on the input side, that is, the direction D2 side, and on the output side, that is, the direction D1 side. Each drive gear train 39 has a rear surface protruding from the housing 35 and a front surface located inside the housing 35. Correspondingly, on the direction D1 side of the relay unit 41, a gear (not shown) that meshes with the portion of the drive gear train 39 that is engaged with the portion protruding from the housing 35 is disposed. In addition, a drive source such as a motor for driving the gear is disposed inside the relay unit 41, and the post-processing devices 31, 32, and 33 are not related to the order of connection in the directions D1 and D2. The drive is performed by the same drive source. Accordingly, it is not necessary to dispose a drive source such as a motor in each of the post-processing devices 31, 32, and 33, and the post-processing devices 31, 32, and 33 are compared with the case where the drive sources are provided. Have been made smaller, lighter and cheaper.

  As shown in FIG. 5, the post-processing device 31 includes a paper feed opening 52 formed on the direction D2 side of the housing 35, a paper discharge opening 53 formed on the direction D1 side of the housing 35, and a paper feed. A sheet conveying path 54 in which the paper opening 52 and the sheet discharging opening 53 communicate with each other, and a driving gear train 39 provided at a position facing the sheet discharging opening 53 at the end of the sheet conveying path 54 in the direction D1. A pair of conveying rollers 55 driven by rotation, a stamping stamper 56 facing the center of the sheet conveying path 54, and a drive mechanism 57 having a solenoid (not shown) that moves the stamping stamper 56 toward the sheet conveying path 54. Have.

  The post-processing device 31 rotates the transport roller pair 55 by the drive gear train 39 at a predetermined timing in the process in which the transfer paper entering from the paper feed opening 52 is transported by the transport roller pair 55 through the sheet transport path 54. At this time, the drive mechanism 57 is activated and the stamping stamper 56 is fed out toward the sheet conveying path 54 to execute the stamp on the transfer paper in the stopped state. The rotation of the conveying roller pair 55 is resumed, and the transfer paper on which the stamp has been applied is discharged from the paper discharge opening 53.

  The drive mechanism 57 is capable of moving the stamp stamper 56 in the vertical direction of the drawing in the drawing, in other words, in the main scanning direction, and with respect to the transfer paper at a plurality of positions in each of the main scanning direction and directions D1 and D2. Thus, the rotational driving means appropriately stops the rotational driving of the conveying roller pair 55 at the timing and time interval necessary for the stamping stamp.

  As shown in FIG. 6, the post-processing device 32 includes a paper feed opening 81 formed on the direction D2 side of the housing 35, a paper discharge opening 82 formed on the direction D1 side of the housing 35, and a paper feed. A sheet conveying path 83 in which the paper opening 81 and the sheet discharging opening 82 communicate with each other, and a driving gear train 39 provided at a position facing the sheet discharging opening 82 at the end of the sheet conveying path 83 in the direction D1. A pair of conveyance rollers 84 that are driven by rotation, a stapler 85 for stapling the transfer paper, an end aligning roller 86 for aligning the trailing end of the transfer paper, and a swing arm 87 that displaces the end aligning roller 86. And have.

  The post-processing device 32 also includes a forward / reverse drive means (not shown) that includes a motor (not shown) that rotates the end aligning roller 86 forward and backward, and a peristaltic drive means (not shown) that includes a motor (not shown) that swings the swing arm 87. Alignment means provided with a jogger fence (not shown) for aligning the transfer paper in the vertical direction of the drawing sheet in the main scanning direction, and the lower roller 89 of the upper roller 88 and the lower roller 89 constituting the conveying roller pair 84, respectively. Displacement means (not shown) provided with a motor (not shown) that is displaced in the vertical direction, advance / retreat drive means (not shown) provided with a motor (not shown) that moves the stapler 85 forward and backward in the sheet conveyance path 83, and transfer paper in the sheet conveyance path 83 A sheet detection sensor (not shown) for detecting whether or not there is.

  The sheet conveying path 83 has a bottom surface that swells downward, and this portion is provided as an end alignment groove 58 for abutting and aligning the rear end of the transfer paper. The stapler 85 is actuated when it enters the end alignment groove 58 by the advance / retreat driving means. The peristaltic drive means swings the peristaltic arm 87 so as to occupy the position where the end aligning roller 86 enters the end aligning groove 58 and the position retracted above the sheet conveying path 83. The sheet detection sensor detects whether or not there is a transfer paper in the end alignment groove 58. The transport roller 84 is driven to rotate by the drive gear train 39, and the lower roller 89 is driven to rotate by the upper roller 88 when it comes into contact with the upper roller 88 by the displacement means.

  In the post-processing device 32, the lower roller 89 is moved at a predetermined timing when the rear end of the transfer paper reaches the end alignment groove 58 in the process in which the transfer paper entering from the paper supply opening 81 is transported by the transport roller pair 84. While being displaced downward by the displacing means and being separated from the upper roller 88, the end aligning roller 86 is displaced downward by the peristaltic driving means and enters the end aligning groove 58, and is reversely rotated by the forward / reverse driving means and transferred. The rear end of the paper is abutted against the lower wall of the alignment groove 58. When this operation is repeated and the trailing edge of the last transfer sheet to be stapled hits the lower wall of the aligning groove 58, the aligning means aligns the bundle of transfer sheets in the main scanning direction, and the advance / retreat driving means continues to the stapler 85. Is entered into the alignment groove 58, the stapler 85 staples the bundle of transfer sheets.

  When stapling is performed, the end aligning roller 86 is rotated forward by the forward / reverse driving means, and the staple-bound bundle of transfer paper is caused to enter between the upper roller 88 and the lower roller 89 which are separated from each other. When a bundle of paper enters between the upper roller 88 and the lower roller 89, the lower roller 89 is displaced upward by the displacing means, and the bundle of transfer paper is sandwiched between the upper roller 89, thereby stapling. The bundle of transferred paper is discharged from the paper discharge opening 82. When the sheet detection sensor no longer detects the transfer sheet, a signal indicating that the next transfer sheet can enter the post-processing device 32 is input to the control unit. Note that the operation of aligning the transfer sheet in the main scanning direction by the aligning unit may be performed in a timely manner, not at the timing when the rear end of the last transfer sheet to be stapled hits the lower wall of the alignment groove 58.

  As shown in FIG. 7, the post-processing device 32 extends in the main scanning direction, which is the left-right direction in the figure, and a shaft 91 that is rotationally driven by the drive gear train 39 and a shaft that is spaced in the main scanning direction. A plurality of rollers 92 fixed to 91, a slide bearing 93 that supports one end of the shaft 91 so as to be rotatable and non-slidable, and a fixed bearing 94 that supports the other end of the shaft 91 so as to be rotatable and slidable. A solenoid 95 that displaces the slide bearing 93 in one direction of the main scanning direction, and a spring 96 that biases the slide bearing 93 in the other direction of the main scanning direction.

  The post-processing device 32 also includes a paper feed opening (not shown) formed on the direction D2 side of the housing 35, a paper discharge opening (not shown) formed on the direction D1 side of the housing 35, and a paper feed opening. And a sheet conveyance path (not shown) that communicates with the discharge opening. A pair of shafts 91 and rollers 92 are provided in a direction perpendicular to the paper surface of the figure, and are driven to rotate in opposite directions by the drive gear train 39 so as to convey the transfer paper in the direction D1 therebetween. In the drawing, only the shaft 91 on the front side of the drawing in the drawing and the roller 92 fixedly disposed on the shaft 91 are shown.

  The post-processing device 31 receives a sort signal at a predetermined timing in a process in which the transfer paper that has entered from the paper feed opening is transported through the sheet transport path by the rotation of the pair of shafts 91 and rollers 92, so that the solenoid 95 Is operated to displace the pair of shafts 91 and the rollers 92 in one direction of the main scanning direction, whereby the transfer paper is discharged from the paper discharge opening in a state of being displaced in the same direction. The pair of shafts 91 and rollers 92 occupy the sorting position displaced in the same direction only when the solenoid 95 is operated.

  As a result, only the transfer paper whose solenoid 95 is operated during the conveyance process occupies a position corresponding to the sorting position, and therefore, the transfer paper is distinguished from other transfer papers, and sorting is performed. A plurality of sort positions may be provided.

  Since the relay unit 41 and the post-processing devices 31, 32, and 33 are configured as described above, the transfer sheet transferred from the main body 99 to the relay unit 41 has its traveling direction reversed from the direction D2 to the direction D1. Depending on the position of the switching claw 48, when the paper is discharged to one of the paper discharge trays 24 and 25 and is discharged to the paper discharge tray 24, the stamp is stamped in the process of passing through the post-processing devices 31, 32 and 33. Staple binding and 1-bin sort are appropriately performed.

  Regardless of whether the paper is discharged to the paper discharge trays 24 and 25, the transfer paper is discharged to the front side of the image forming apparatus 100, so that it is easy to take out. Further, since the paper discharge tray 25 is constituted by the upper surfaces of the post-processing devices 31, 32, 33, the number of parts and the increase in size are suppressed.

  The post-processing unit is not limited to the post-processing devices 31, 32, and 33, and a post-processing unit having other functions, for example, a function having a punching punch function, may be prepared and attached to the image forming apparatus 100 as necessary. When mounting the image forming apparatus 100 on the image forming apparatus 100, a plurality of types having different functions or one of the types is selected as necessary. Therefore, the post-processing apparatus is selected according to the user's request, and a plurality of post-processing can be performed by one image forming apparatus 100, which is highly convenient. When preparing a different type of post-processing unit from the post-processing devices 31, 32, and 33, the number corresponding to the type of wiring address of the electrical connection unit 34 is prepared. The image forming apparatus 100 may be configured to be equipped with four or more post-processing units at the same time.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments, and the present invention described in the claims is not specifically limited by the above description. Various modifications and changes are possible within the scope of the above.

  For example, in the above-described embodiment, the main body 99, the relay unit 41, and the image reading unit 23 are integrated and cannot be separated, but the relay unit 41 is an optional sheet reversing device that is detachable from the image forming apparatus 100. In this case, the transfer paper take-out direction is set according to the arrangement of the image forming apparatus 100 and the like. In this case, the image reading unit 23 can also be an option.

  Regardless of whether the relay unit 41 is an option or not, depending on the internal configuration of the main body 99, the relay unit 41 may be provided below the main body 99. In this case, the post-processing devices 31, 32, 33, etc. The post-processing unit is also provided below the main body 99.

  In the above-described form, the relay unit 41 reverses the traveling direction of the transfer paper in such a manner that the transfer paper is reversed, but the transfer unit 41 may reverse the traveling direction of the transfer paper in a so-called switchback manner.

  The transfer paper may be transported in a substantially S shape instead of being transported in a substantially U shape in the image forming unit. At this time, if the paper feeding direction is the front side of the image forming apparatus, the paper discharge direction in the image forming unit is also the front side of the image forming apparatus, and the entire image forming apparatus is discharged to the back side of the image forming apparatus by the sheet reversing unit. Paper is used, but such a configuration is suitable when it is desirable to take out the transfer paper after image formation on the back side of the image forming apparatus.

  The present invention is not a so-called tandem type image forming apparatus, but a so-called one-drum type image forming apparatus that sequentially forms toner images of each color on a single photosensitive drum and sequentially superimposes the color toner images to obtain a color image. It can be similarly applied to. Further, the present invention can be applied not only to a color image forming apparatus but also to a monochrome image forming apparatus. In any type of image forming apparatus, the intermediate transfer member may be in the form of a drum, or each color toner image may be directly transferred onto a transfer sheet or the like without using the intermediate transfer member.

  The image forming apparatus is not limited to the so-called electrophotographic image forming apparatus described above, and may be an image forming apparatus using ink such as an ink jet system, a printing apparatus such as a stencil printing apparatus, and a facsimile, etc. Or a multi-function machine.

  The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

1 is a schematic perspective view of an image forming apparatus to which the present invention is applied. FIG. 2 is a schematic side sectional view of the image forming apparatus shown in FIG. 1. FIG. 2 is a schematic side sectional view of an image forming unit provided in the image forming apparatus shown in FIG. 1. 2A and 2B are diagrams illustrating a configuration common to a post-processing unit provided in the image forming apparatus illustrated in FIG. 1, wherein FIG. 2A is a partially transparent schematic plan view, and FIG. FIG. 2 is a side sectional view schematically showing one of post-processing units provided in the image forming apparatus shown in FIG. 1. FIG. 5 is a side sectional view schematically showing another one of post-processing units provided in the image forming apparatus shown in FIG. 1. FIG. 6 is a plan sectional view schematically showing still another one of post-processing units provided in the image forming apparatus shown in FIG. 1.

Explanation of symbols

23 Document reading section 25 Paper discharge tray 26 Guide means 31, 32, 33 Post-processing section, post-processing apparatus 34 Electrical connection section 38 Electrical path wiring 41 Sheet reversing section, sheet reversing apparatus 44 First transport path 45 Second Transport path 99 Image forming unit 100 Image forming apparatus D1 Front side of image forming apparatus D1, D2 Advancing direction of sheet

Claims (6)

An image forming unit for forming an image on a sheet;
A sheet reversing device including a sheet reversing unit that accepts an image-formed sheet, reverses the traveling direction of the sheet, and discharges the sheet to the front side of the image forming device ;
When a predetermined post-processing is performed on the sheet that has passed through the sheet reversing section, and a post-processing section that can be selected from a plurality of types having different functions and is detachable from the image forming apparatus is mounted on the image forming apparatus And guiding means for guiding to
The sheet reversing unit receives a first portion that receives and conveys the sheet, a second portion that reverses the traveling direction of the sheet that has passed through the first portion, and the sheet that has passed through the second portion . A first conveyance path that leads the front processing unit positioned above the first part toward the front side, and the sheet that has passed through the second part is not guided to the post processing unit without being guided to the post processing unit. discharged toward the front side upwardly, and a second transport path located above the first portion possess, provided the sheet inverting portion above or below the image forming unit,
A plurality of the post-processing units are arbitrarily arranged from the back side of the image forming apparatus toward the front side by the guide unit on the side where the sheet reversing unit is provided above or below the image forming unit. In this order, the image forming apparatus can be attached to the image forming apparatus at the same time so as to be connected to each other, and at least the back side and the near side are driven by a driving source provided in the sheet reversing unit. Have a common layout drive gear train,
The plurality of post-processing units in the state are driven by the drive source when the drive gear trains provided in the respective post-processing units are connected to each other from the back side toward the front side, In the process of transporting to the front side, the sheet that has been discharged from one transport path is transported by passing the sheet from the back side to the front side while maintaining the traveling direction of the sheet at the front side. A predetermined post-processing is performed, and the sheet is discharged to the front side from the front-end processing unit closest to the front side among the plurality of post-processing units, and an upper surface thereof is a second one. An image forming apparatus for forming a paper discharge tray on which the sheets discharged to the near side by a conveyance path are stacked . The image forming apparatus according to claim 1.
An image forming apparatus, wherein the sheet reversing device is detachable . The image forming apparatus according to claim 1 or 2,
An image forming apparatus comprising an original reading unit for reading an original image, and the original reading unit provided above the sheet reversing unit and the image forming unit. A post-processing apparatus comprising the post-processing unit used in the image forming apparatus according to claim 1 and having the drive gear train having the common layout . The post-processing apparatus according to claim 4, wherein
The post-processing apparatus characterized in that an electrical connection section for connecting to the other post-processing section is compatible with each type . The post-processing apparatus according to claim 4 or 5,
A post-processing apparatus having wiring for an electrical path for the other post-processing unit.

Images