JP2011158510A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which includes one or more image forming parts capable of forming toner images. <P>SOLUTION: The image forming apparatus 10 is configured to primarily transfer further the toner image to an intermediate transfer belt 7; then to secondarily transfer the toner image to a paper S ascending from a recording-paper supply part 10S; further, to move the paper S upward to pass through a fixing device 9 and fix the secondarily-transferred toner image onto the paper S; and then, to eject the paper S to a paper ejection tray 13. The image forming apparatus includes a side cover C1 capable of opening/closing paper-ascending conveying paths P2 and P3 from the paper supply part 10S; and an upper cover C2 capable of opening/closing an area A, including the fixing device 9. An image reading device 100 is externally attached to the image forming apparatus so as to be detachable above the fixing device 9. Even in a state with the device 100 attached to the image forming apparatus, the cover C2 and the cover C1 can be opened/closed readily, and maintenance work of the image forming apparatus can be also performed without difficulties. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention includes one or more image forming units capable of forming an electrostatic latent image on an electrostatic latent image carrier by an electrophotographic method or an electrostatic recording method and developing the latent image to form a toner image. The toner image formed by the image forming unit is primarily transferred to an intermediate transfer belt, and the primary transfer toner image on the belt is recorded on a recording sheet such as a recording sheet or an overhead projector sheet (hereinafter referred to as “recording sheet”). Or an image forming apparatus that can be secondarily transferred to and fixed on a sheet.

  There are various types of image forming apparatuses of this type, and among them, the toner image on the intermediate transfer belt is secondarily transferred to the recording paper and fixed, and then supplied from the recording paper supply unit. The toner image on the belt is secondarily transferred onto the recording sheet that is transferred, and the recording sheet is further raised and passed through the fixing device to fix the secondary transfer toner image, and is discharged onto the discharge tray above the intermediate transfer belt. There is something to discharge.

  In this image forming apparatus, the image forming apparatus further includes a side cover for maintenance work that can open and close a recording paper ascending conveyance path from the recording paper supply unit, and opens and closes an area including the fixing device. Some have a top cover for maintenance work possible.

  Such an image forming apparatus can be used, for example, as a printer that receives image information from an external computer or the like and prints an image, and is further positioned above an area including the fixing device and a discharge tray. Some image readers can be retrofitted so that they can be combined into a multifunction machine (MFP) having a copier function, a printer function, or a facsimile function.

  An image forming apparatus capable of being combined as described above is described in, for example, Japanese Patent Application Laid-Open No. 2007-271893.

JP 2007-271893 A

  In this way, in an image forming apparatus capable of being combined, even if an image reading device is mounted, there may be no problem in opening and closing the side cover and the top cover. In response to a request for downsizing, when the image reading device is mounted, the side cover can be opened and closed, but the upper surface cover may not be able to be opened and closed with the image reading device mounted.

  When the upper surface cover cannot be opened and closed with the image reading device mounted, if maintenance such as jam processing and parts replacement is required by opening the upper surface cover, the image reading device must be removed one by one. As a result, maintenance takes too much time and effort, and as a result, the image productivity decreases.

  Accordingly, the present invention includes one or more image forming units that can form an electrostatic latent image on an electrostatic latent image carrier and develop the latent image to form a toner image, and are formed by the image forming unit. The toner image is primarily transferred to an intermediate transfer belt, and the primary transfer toner image on the belt is secondarily transferred by a secondary transfer member to a recording sheet that is supplied from a recording sheet supply unit and is raised, The recording paper can be further raised, passed through a fixing device to fix the secondary transfer toner image, and discharged onto a discharge tray above the intermediate transfer belt. A side cover for maintenance work that can be opened and closed and an upper surface cover for maintenance work that can open and close an area including the fixing device. An image forming apparatus in which the image reading device is detachably mounted so as to be positioned above the rear and the discharge tray, and the upper surface cover and the side cover can be easily installed even when the image reading device is mounted. It is an object of the present invention to provide an image forming apparatus that can be opened and closed and that does not interfere with maintenance work.

In order to solve the above problems, the present invention
An electrostatic latent image is formed on an electrostatic latent image carrier, and the latent image is developed and includes one or more image forming units capable of forming a toner image. The toner image formed by the image forming unit is intermediately transferred. Primary transfer is performed on the belt, and the primary transfer toner image on the belt is secondarily transferred to the recording paper that is supplied from the recording paper supply unit and is raised by the secondary transfer member, and the recording paper is further raised. The secondary transfer toner image can be fixed by passing it through a fixing device and discharged onto a discharge tray above the intermediate transfer belt, and a maintenance mechanism capable of opening and closing a recording paper ascending conveyance path from the recording paper supply unit. A side cover for work and an upper surface cover for maintenance work capable of opening and closing an area including the fixing device are provided, and the image reading device is positioned above the area including the fixing device and the discharge tray. An image forming apparatus that is retrofitted and detachably mounted, and the side cover is opened by swinging downward with the lower end of the cover as a swing center portion regardless of whether or not the image reading apparatus is mounted, and swinging upward. The top cover can be detachably attached to the side cover, and the image reading apparatus is mounted on the side cover while the image reading apparatus is mounted, and the top cover is interlocked with the opening and closing of the side cover. Provided is an image forming apparatus that employs a top cover that can open and close an area including a fixing device and can be removed from the side cover when the side cover is open.

  According to the image forming apparatus of the present invention, the side cover can be opened by swinging downward with the lower end of the cover as a swing center portion and closed by swinging upward regardless of whether the image reading device is mounted. As for the top cover, the area including the fixing device can be opened and closed in conjunction with opening and closing of the side cover while the image reading device is mounted on the side cover. The side cover when the reading device is not installed can be used as it is, so that it can be made cheaper, its opening and closing is easy and maintenance can be performed by opening the side cover, and the top cover can be opened and closed together with the side cover. In addition, maintenance can be performed by opening the top cover.

  In addition, when the top cover is opened in conjunction with the side cover, maintenance can be performed if the top cover is not attached to the side cover. However, since the top cover has a side cover, it is obstructive. For parts and parts that can not be nonce, maintenance can be performed by removing the top cover from the side cover.

  As described above, according to the image forming apparatus of the present invention, both the upper surface cover and the side surface cover can be easily opened and closed even when the image reading device is mounted, and in some cases, the upper surface cover is removed from the side surface cover. Maintenance work can be performed, so there is no problem in maintenance work.

  Examples of the maintenance work target include an intermediate transfer unit including at least the intermediate transfer belt. In order to be able to pull out and push in the intermediate transfer unit for replacement of the intermediate transfer unit while the image reading device is mounted, the intermediate transfer unit is opened with the side cover together with the upper surface cover. The upper cover may be removed from the open side cover so that it can be pulled out to the upper area of the open side cover, and can be pushed in from the upper area.

  In the image forming apparatus according to the present invention, the image reading device is removed, and the side cover for opening and closing the recording paper ascending conveyance path is directly used as the side cover when the image reading device is mounted, and the upper surface As for the cover, it is possible to adopt an upper cover that can be opened and closed independently of the side cover.

As explained above, according to the present invention,
An electrostatic latent image is formed on an electrostatic latent image carrier, and the latent image is developed and includes one or more image forming units capable of forming a toner image. The toner image formed by the image forming unit is intermediately transferred. Primary transfer is performed on the belt, and the primary transfer toner image on the belt is secondarily transferred to the recording paper that is supplied from the recording paper supply unit and is raised by the secondary transfer member, and the recording paper is further raised. The secondary transfer toner image can be fixed by passing it through a fixing device and discharged onto a discharge tray above the intermediate transfer belt. A side cover for work and an upper surface cover for maintenance work capable of opening and closing an area including the fixing device are provided, and the image reading device is positioned above the area including the fixing device and the discharge tray. An image forming apparatus that is detachably mounted later, and can be easily opened and closed with respect to both the upper surface cover and the side surface cover while the image reading device is mounted, and there is no problem in maintenance work. Can be provided.

1 is a diagram schematically illustrating a configuration of an example of an image forming apparatus according to the present invention. FIG. 2 is a diagram illustrating a state in which a side cover is opened together with an upper cover in the image forming apparatus of FIG. 1. FIG. 2 is a view showing a state where an upper surface cover is removed from an opened side cover and an intermediate transfer unit is pulled out in the image forming apparatus of FIG. FIG. 2 is a diagram illustrating a positioning member that positions an intermediate transfer unit and a sheet conveyance guide in the image forming apparatus of FIG. 1, and a positioning state of the intermediate transfer unit and the sheet conveyance guide in the positioning member. FIG. 5 is a diagram illustrating a state where the sheet conveyance guide is lowered to the retracted position from the positioning state of FIG. 4 and the intermediate transfer unit is pulled out. FIG. 2 is a diagram illustrating an image forming apparatus in which an image reading apparatus is removed from the image forming apparatus in FIG. 1.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 schematically shows the configuration of an example 10 of an image forming apparatus according to the present invention. The image forming apparatus 10 is a tandem type full-color image forming apparatus, and is a complex machine having functions such as a copying machine, a printer, and a facsimile machine.

  The image forming apparatus 10 includes a printer part PR and an image reading apparatus 100 mounted later on the printer part PR. The printer PR has an endless intermediate transfer belt 7 wound around a driving roller 71 and a roller 72 facing the driving roller 71. The rollers 71 and 72 are rotatably supported by a pair of frames F (shown by chain lines in FIG. 1). The transfer belt 7 is rotated in the counterclockwise direction (arrow direction in the figure) CCW by a driving roller 71 driven by a belt driving unit (not shown).

  A cleaning device 73 that cleans secondary transfer residual toner and the like on the transfer belt 7 faces the roller 72, and a secondary transfer roller 8 faces the drive roller 71. The cleaning device 73 is supported by the frame F.

  The frame F, rollers 71 and 72 supported by the frame F, the intermediate transfer belt 7 wound around these rollers, the cleaning device 73, and the like constitute an intermediate transfer unit U.

  As will be described later, the intermediate transfer unit U is positioned at a normal position for image formation by a pair of positioning members 700 arranged on both outer sides of the intermediate transfer unit U, and can be pulled out from the positions as described later. .

  The secondary transfer roller 8 is pressed against the portion of the intermediate transfer belt 7 supported by the drive roller 71 in the unit U at the normal position by a pressing means (not shown), and a nip portion is formed between the secondary transfer roller 8 and the intermediate transfer belt 7. Rotate following the rotation of the intermediate transfer belt 7 or driven by or driven by the movement of the recording paper (recording paper, overhead projector sheet, etc.) fed into the nip as will be described later. Can do. A secondary transfer bias can be applied to the secondary transfer roller 8 from a power supply (not shown).

  A fixing device 9 is disposed above the intermediate transfer belt 7 and the secondary transfer roller 8, a timing roller pair 11 is disposed below, and a supply cassette 10S for the recording paper S is disposed below the fixing device 9. Has been.

The fixing device 9 includes a fixing heating roller having a heat source such as a halogen lamp heater and a pressure roller pressed against the fixing heating roller.
The recording paper S stored in the recording paper storage cassette 10 </ b> S can be pulled out one by one by the paper supply roller 101 and supplied to the timing roller pair 11.

  Between the rollers 71 and 72 around which the intermediate transfer belt 7 is wound, the yellow image forming unit Y, the magenta image forming unit M, and the cyan image forming unit C are arranged along the transfer belt 7 from the roller 72 toward the roller 71. And the black image forming portion K are arranged in this order.

  Each of the image forming units Y, M, C, and K includes a drum-type photosensitive member 1 as an electrostatic latent image carrier, and a charger 2, an exposure device 3, a developing device 4 and the like around the photosensitive member. The cleaning devices 5 are arranged in this order.

A primary transfer roller 6 is disposed opposite to the photoreceptor 1 of each image forming unit with a belt 7 therebetween. The primary transfer roller 6 is pressed in the direction of the photosensitive member 1 by a pressing unit (not shown), contacts the belt 7 and rotates in a driven manner, and can bring the belt 7 into contact with the photosensitive member 1.
These primary transfer rollers 6 are also mounted on the intermediate transfer unit U.

  A primary transfer bias for primary transfer of the toner image formed on the photoreceptor 1 to the belt 7 can be applied to the primary transfer roller 6 from a power supply (not shown).

  In accordance with image information provided from a personal computer (not shown), the image reading device 100, and the like, the exposure device 3 performs image exposure by dot (point) exposure on the photosensitive member 1 by blinking of a laser beam, and an electrostatic latent image. Can be formed.

  The image reading apparatus 100 reads an image for copying of a document image, facsimile transmission of the document image, reading of the document image and storage in a storage unit, and the like, which is a type already known per se. .

  The photoconductor 1 in each image forming unit is a negatively chargeable photoconductor here, and can be driven to rotate clockwise in the drawing by a photoconductor drive motor (not shown).

  The charger 2 in each image forming unit is a scorotron charger in this example, and a charging voltage is applied from a power supply (not shown) at a predetermined timing. The charger 2 may be one using a charging roller.

  In this example, the developing device 4 in each image forming unit applies a developing bias to an electrostatic latent image formed on the photoreceptor 1 using a one-component developer mainly composed of toner from a power supply (not shown). The developer carrying rotating body (hereinafter referred to as “developing roller”) 41 (see FIG. 2) in the form of a roller can be used for reversal development.

According to this printer, an image can be formed using one or more of Y, M, C, and K image forming units.
Taking a case where a full color image is formed using all of the image forming portions Y, M, C, and K as an example, first, a yellow toner image is formed in the yellow image forming portion Y, and this is formed on the transfer belt 8 as a primary. Transcript.

  That is, in the yellow image forming portion Y, the photosensitive member 1 is rotationally driven in the clockwise direction in the drawing, and the surface is uniformly charged to a predetermined potential by the charger 2, and the exposure device 3 corresponds to the yellow image in the charged area. Thus, an electrostatic latent image corresponding to the yellow image is formed on the photoreceptor 1.

  This electrostatic latent image is developed by a developing roller 41 to which a developing bias of the developing device 4 having yellow toner is applied, and becomes a visible yellow toner image. The yellow toner image is primarily transferred onto the transfer belt 7 by the primary transfer roller 6. At this time, a primary transfer bias is applied to the primary transfer roller 6 from a power supply (not shown).

  Similarly, a magenta toner image is formed in the magenta image forming unit M and transferred to the transfer belt 7. A cyan toner image is formed in the cyan image forming unit C and transferred to the transfer belt 7. In the black image forming unit K. A black toner image is formed and transferred to the transfer belt 7.

Yellow, magenta, cyan, and black toner images are formed at a timing when these toner images are transferred onto the intermediate transfer belt 7 in an overlapping manner.
Thus, the multiple toner image formed on the transfer belt 7 moves toward the secondary transfer roller 8 by the rotation of the transfer belt 7.

  On the other hand, the recording paper S is pulled out from the recording paper storage cassette 10S by the medium paper roller 101, supplied to the timing roller pair 11 through the paper ascending conveyance path (recording paper guide path) P1, and is on standby.

  In this way, the recording sheet S waiting at the timing roller pair 11 is transported up to the nip portion between the transfer belt 7 and the secondary transfer roller 8 in accordance with the multiple toner image sent by the intermediate transfer belt 7. Supplied through a path (recording paper guide path) P2. The multiple toner image is secondarily transferred onto the recording paper S by a secondary transfer roller 8 to which a secondary transfer bias is applied from a power source (not shown).

  Thereafter, the recording paper S is passed through the fixing device 9 through a paper ascending conveyance path (recording paper guide path) P3, where the multiple toner images are fixed on the recording paper S under heat and pressure. The recording sheet S is continuously discharged from the transport path (recording sheet guide path) P4 to the discharge tray 13 by the discharge roller pair 12.

  In the primary transfer of the toner image to the belt 7, transfer residual toner or the like remaining on the photoreceptor 1 is cleaned by the cleaning device 5, and secondary transfer residual toner or the like remaining on the belt 7 by the secondary transfer is cleaned by the cleaning device 73. It is cleaned with. Each of these cleaned and removed toners is sent to a waste container by a conveying means (not shown).

  The printer portion PR will be further described. Among the paper transport paths (recording paper guide paths) P1, P2, P3, and P4, in this example, the paper ascending transport paths P2 and P3 are used for jam processing and consumables (in this case, particularly intermediate A side cover C1 is provided for opening and closing the transfer unit U) for inspection, replacement or the like.

  An upper surface cover C2 that covers the area A including the fixing device 9 from above and that can be opened and closed is also provided. The cover C2 is detachably attached to the upper end of the cover C1. Although not limited thereto, in this example, a plurality of protrusions c21 are provided to protrude from the upper surface cover C2, and a hole c11 is formed in the upper end surface of the side cover C1 so that the protrusions c21 can be pulled out. Has been.

The side cover C1 includes a guide part p21 for forming the paper ascending conveyance path P2, a secondary transfer roller 8, a guide part p31 for forming the paper ascending conveyance path P3, and the like.
When the side cover C1 is closed as shown in FIG. 1, the guide portion p21 forms a transport path P2 together with the paper transport guide G on the printer main body side, and the guide portion p31 transports with the paper guide portion p32 on the printer main body side. A path P3 is formed.

  The side cover C1 can be opened by swinging down and closed by swinging up and down around a hinge portion s that pivotally connects the lower end of the cover to the printer body. Even when the image reading apparatus 100 is mounted on the printer PR as shown in FIG. 1, the upper surface cover C2 can be opened and closed in conjunction with the opening and closing of the side cover C1 without colliding with the image reading apparatus 100.

  FIG. 2 shows a state in which the side cover C1 is opened with the top cover C2 attached thereto, and FIG. 3 shows that the top cover C1 is removed from the side cover C1 thus opened (and thereby the top cover C1 is also opened). This shows a state where the intermediate transfer unit U can be pulled out from the normal position for image formation or pushed into the position.

  As described above, the intermediate transfer unit U is positioned at a normal position for image formation by the pair of positioning members 700 arranged on both outer sides of the intermediate transfer unit U, and can be pulled out from the position. In the positioning member 700, a portion 702 closer to the side cover C1 is integrally bent downward, and the sheet conveyance guide G is supported by the portion 702. That is, the sheet conveyance guide G is disposed between the pair of positioning members 700 located on both outer sides of the intermediate transfer unit U, and is supported by the support portion 702 of the sheet conveyance guide G that is also a part of the member 700. Yes.

  The matters relating to the positioning member 700 will be further described. As shown in FIGS. 4 and 5, each positioning member 700 positions the intermediate transfer unit U at a normal position (position shown in FIGS. 1 and 4) for image formation. In addition, it has a groove-shaped intermediate transfer unit guide 701 that guides it so that it can be pulled out from that position, or pushed into that position.

  As shown in FIG. 4, pin members 71 p and 72 p having the same central axis as the shafts 71 s and 72 s of the rollers 71 and 72 of the intermediate transfer unit U that are rotatably supported by the frame F protrude to the outside of the frame F. It can be guided by being fitted into the groove-shaped guide portion 701. In this way, the intermediate transfer unit U can be pushed into the normal position while being guided by the guide portion 701, or can be pulled out from the normal position as shown in FIG.

  When the unit U is disposed at the normal position, the pin member 71p corresponding to the shaft 71s of the roller 71 contacts the stopper st fixed to the outer surface of the positioning member 700, and is set at that position by the spring sp1. In this way, the unit U is arranged at the normal position and is stably held there. The spring sp1 is also provided on the member 700. When the unit is mounted, the spring sp1 is pushed upward by the pin member 71p and presses the pin member. When the unit is pulled out, it is pushed by the pin member 71p and then lowered.

  The stopper st and the spring sp1 are arranged so as not to prevent the unit U from being attached and detached, and are fixed to the member 700. The intermediate transfer unit U is easily attached and detached by holding a handle 74 (see FIG. 3) provided on the frame F.

  As shown in FIGS. 4 and 5, the sheet conveying guide G is provided with upper and lower pins Gp 1 and Gp 2 on both side surfaces thereof, and the upper pin Gp 1 is formed in the upper groove gr 1 of the portion 702 of the member 700. The lower pin Gp2 is fitted in the lower groove gr2 of the part 702 of the member 700 so as to be movable up and down.

  As shown in FIG. 4, the sheet transport guide G is manually lifted up so that the upper pin Gp1 reaches the upper limit of the upper groove gr1 and is pressed by the spring sp2 (in other words, for image formation). The paper transport path P2 is formed with the side cover C1 closed in a normal position (for recording paper guidance).

  As shown in FIG. 3, a triangular paper conveyance guide driving member 75 is provided on the lower surface of the end of the intermediate transfer unit U on the cover C1 side of the frame F, as viewed from the side. When pulling out, the inclined surface of the drive member 75 pushes down the paper transport guide G, so that the paper transport guide G is pushed down against the spring sp2, as shown in FIG. It is lowered to the retracted position. Ascending from this position to the normal position is performed manually.

  The paper transport guide G takes a position close to the intermediate transfer unit U when placed at the normal position. In this example, a density sensor SE is mounted on the paper transport guide G, and the sensor SE is also located near the intermediate transfer belt 7. However, when the intermediate transfer unit U is pulled out or attached, the sensor SE is also lowered to the retracted position together with the paper transport guide G, so that damage to the sensor SE due to collision with the intermediate transfer unit U or the like can be suppressed accordingly.

  The density sensor SE detects the density of a toner image such as a toner pattern or a toner patch formed on the intermediate transfer belt 7 for image density adjustment or color misregistration correction. It is used to detect the position of an image and is already known per se.

  According to the image forming apparatus 10 described above, the side cover C1 is opened by swinging downward with the hinge s at the lower end of the cover as the swing center part regardless of whether or not the image reading apparatus 100 is mounted, and swings upward. With respect to the top cover C2, the area A including the fixing device 9 can be opened and closed in conjunction with the opening and closing of the side cover C1 with the image reading apparatus 100 mounted and attached to the side cover C1.

  Therefore, as for the side cover C1, the side cover C1 when the image reading apparatus 100 is not mounted can be used as it is, and the cost can be reduced as much, and the side cover C1 can be easily opened and closed, and can be maintained by opening the side cover C1. The upper cover C2 is convenient because the area A can be easily opened and closed together with the side cover C1, and the upper cover C2 can be opened to perform maintenance of the area A.

  In the state where the top cover C2 is opened in conjunction with the side cover C1, maintenance is possible if the top cover C2 is not attached to the side cover C1, but the top cover C2 is attached to the side cover so that it is in the way. For parts and parts that cannot be maintained (for example, the intermediate transfer unit U), the top cover C2 is removed from the side cover C1, in other words, open to such parts and parts (for example, the intermediate transfer unit U). Since maintenance can be performed using the space above the wide side cover C1, there is no problem.

  When the image reading apparatus 100 is removed and used only as the printer portion PR, as shown in FIG. 6, the side cover that opens and closes the recording paper ascending conveyance path is the side surface when the image reading apparatus 100 is mounted. The cover C1 can be used as it is, and the top cover can be used by adopting a top cover C3 that can be opened and closed independently of the side cover C1.

  Furthermore, the printer PR is manufactured independently from the image reading apparatus 100. However, if the image reading apparatus 100 is manufactured so that it can be retrofitted, the side cover C1 and the upper surface cover can be used as maintenance covers. The cover C3 can be used and sold as a printer PR, and when the image reading apparatus 100 is retrofitted for MFP or the like, the side cover C1 can be used as it is, and the top cover can be used simply by using the cover C2. .

  Further, according to the image forming apparatus 10 of FIG. 1 described above, particularly the printer portion PR, or according to the image forming apparatus (printer) PR of FIG. 6, the intermediate transfer unit U must be pulled out or pushed in for maintenance or the like. If not, the cover C1 is opened (the cover C2 is also removed from the cover C1 in the apparatus of FIG. 1), and the intermediate transfer of the positioning member 700 provided integrally with both the intermediate transfer unit U and the paper transport guide G is performed. The intermediate transfer unit U can be guided by the unit guide portion 701, and can be pulled out or pushed in. At this time, the sheet conveyance guide G is supported by the sheet conveyance guide support portion 702 of the positioning member 700 provided integrally so that the sheet conveyance guide G does not interfere with operations such as drawing out the intermediate transfer unit U. In addition, the sheet transfer guide G can be retracted to the retracted position, and the sheet transfer guide G can be positioned to the regular position after the intermediate transfer unit U is mounted at the regular position.

  As described above, in the image forming apparatus 10 (printer PR), the intermediate transfer unit and the paper transport guide are mounted on the intermediate transfer unit U and the paper transport guide G using the positioning members separately provided in the main body of the image forming apparatus. Compared with the case of positioning, the mutual positional relationship between the two can be maintained with high accuracy, and each can be positioned accurately and easily.

  Further, in the image forming apparatus 10 (printer PR), the intermediate transfer unit U is pulled out from the normal position with the cover open, and the sheet conveyance guide G is recorded by the driving member 75 of the frame F of the intermediate transfer unit by the pulling operation. Since the sheet can be driven from the normal position for guiding the sheet to the retracted position, the maintenance of the intermediate transfer unit U is less likely to cause the two to collide and be damaged, and the intermediate transfer unit U can be pulled out safely. .

  Further, when the intermediate transfer unit U is mounted at the regular position, the intermediate transfer unit U can be mounted safely by performing the mounting operation with the sheet transport guide G being retracted to the retracted position.

The image forming apparatus 10 and the printer PR described above are tandem type color image forming apparatuses. However, the present invention can be applied to, for example, a so-called cycle type color image forming apparatus.
The cycle type color image forming apparatus, for example, forms an electrostatic latent image on an electrostatic latent image carrier such as a photoconductor with an exposure device, and moves the electrostatic latent image to an electrostatic latent image developing area. A toner image is formed by developing with a developing device that holds the assigned color toner corresponding to the electrostatic latent image among a plurality of possible developing devices, and the toner image is primarily transferred to an intermediate transfer belt, A monochrome toner image or a multiple toner image composed of two or more toner images can be formed on the intermediate transfer belt, and the toner image on the intermediate transfer belt can be secondarily transferred to a recording sheet and fixed.
Such an image forming apparatus can also be regarded as having a plurality of image forming units that share a photoconductor.

  The present invention is an image forming apparatus that is retrofitted with an image reading device, and that can open and close an area including a side cover and a fixing device for maintenance work that can open and close a recording paper ascending conveyance path from a recording paper supply unit. To provide an image forming apparatus having a top cover for maintenance work, which can be easily opened / closed for both the top cover and the side cover while the image reading apparatus is mounted, and which does not interfere with the maintenance work. Available to:

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 100 Image reading apparatus PR Printer (printer part)
Y Yellow image forming portion M Magenta image forming portion C Cyan image forming portion K Black image forming portion 1 Photoconductor 2 Charger 3 Exposure device 4 Developing device 41 Developing roller 5 Photoconductor cleaning device 6 Primary transfer roller 7 Intermediate transfer belt 73 Belt cleaning device U Intermediate transfer unit G Paper transport guides P1, P2, P3, P4 Ascending transport path (guide path) of recording paper
C1 Side cover s Hinge portions C2 and C3 at the lower end of the cover C1 Top cover A Area 700 including the fixing device Positioning member 701 Intermediate transfer unit guide portion 702 Paper conveyance guide support portion (part of the positioning member)
8 Secondary transfer roller 9 Fixing device 10S Recording paper supply unit 101 Recording paper supply roller 13 Discharge tray

Claims (3)

  An electrostatic latent image is formed on an electrostatic latent image carrier, and the latent image is developed and includes one or more image forming units capable of forming a toner image. The toner image formed by the image forming unit is intermediately transferred. Primary transfer is performed on the belt, and the primary transfer toner image on the belt is secondarily transferred to the recording paper that is supplied from the recording paper supply unit and is raised by the secondary transfer member, and the recording paper is further raised. The secondary transfer toner image can be fixed by passing it through a fixing device and discharged onto a discharge tray above the intermediate transfer belt, and a maintenance mechanism capable of opening and closing a recording paper ascending conveyance path from the recording paper supply unit. A side cover for work and an upper surface cover for maintenance work capable of opening and closing an area including the fixing device are provided, and the image reading device is positioned above the area including the fixing device and the discharge tray. An image forming apparatus that is retrofitted and detachably mounted, and the side cover is opened by swinging downward with the lower end of the cover as a swing center portion regardless of whether or not the image reading apparatus is mounted, and swinging upward. The top cover can be detachably attached to the side cover, and the image reading apparatus is mounted on the side cover while the image reading apparatus is mounted, and the top cover is interlocked with the opening and closing of the side cover. Provided is an image forming apparatus characterized in that an upper surface cover that can open and close an area including a fixing device and that can be removed from the side cover when the side cover is open is used.   The maintenance work target is an intermediate transfer unit including at least the intermediate transfer belt. When the image reading device is mounted, the intermediate transfer unit opens the side cover together with the upper surface cover, and opens the side cover from the opened side cover. The image forming apparatus according to claim 1, wherein the image forming apparatus can be pulled out to an upper area of the opened side cover by removing the upper surface cover, and can be pushed in and mounted from the upper area.   In the state where the image reading device is not mounted, the side cover when the image reading device is mounted is adopted as the side cover that opens and closes the recording paper ascending conveyance path. The image forming apparatus according to claim 1, wherein a top cover that can be opened and closed independently of the side cover is employed.

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