JP4343658B2 - Color image forming apparatus - Google Patents

Description

  The present invention relates to a color image forming apparatus such as a printer, a copying machine, and a facsimile using an electrophotographic system.

  Conventionally, as a color image forming apparatus, a developing device that stores a color developer such as yellow, magenta, and cyan, and a developing device that stores a black developer in addition to the three colors in some cases, are provided. A plurality of developing devices are arranged linearly or curvedly, and the electrostatic latent image corresponding to the developer of each color formed on the image carrier is developed to obtain a developed image (that is, a toner image). There is a configuration one.

  Further, there are a direct transfer method and an intermediate transfer method for the transfer process from the transfer of the plurality of toner images onto the transfer material until the final visible image is obtained.

  In the direct transfer method, since a toner image is transferred from an image carrier to a transfer material, the transfer environment due to the physical properties of the transfer material, the transfer property of the transfer material, and the like affect the image quality. On the other hand, in the intermediate transfer method, since the transfer target in the step of overlapping the developer is always the same object, that is, the intermediate transfer body, a superimposed image can be obtained stably.

  In a color image forming apparatus using an intermediate transfer member, a developer that is a consumable item may be used up in a cycle shorter than the life of the apparatus main body. In that case, there is a method of supplying the developer or replacing the developing device including the developer.

  Further, even in a color image forming apparatus using an intermediate transfer member, a defective image may occur due to mishandling by a user, unexpected damage, deterioration due to long-term use, and the like. Therefore, in order to obtain a good image, it is essential to repair or replace the intermediate transfer member.

  However, a developing device using an electrophotographic technique and an adjacent image carrier are generally surrounded by an exposure device for forming an electrostatic latent image on the image carrier or an intermediate transfer member in the next process of the developed image. It is often arranged in the state of being. Further, since there are a plurality of components such as a cleaning mechanism for removing the developer that is not transferred to the transfer material and remaining on the intermediate transfer member, and a container for the removed developer, conventionally, for example, As described in Patent Document 1, there is a configuration in which a plurality of doors are provided in an image forming apparatus for replacement of a developing device so that a user can access the inside of the apparatus main body. However, it has never been excellent in maintenance.

  10 and 11 show a schematic configuration of a conventional color image forming apparatus.

  In this example, the color image forming apparatus includes four image forming units PY, PM, PC, and PBK arranged in the horizontal direction, and each of the image forming units PY, PM, PC, and PBK has a first image. A photosensitive drum 1 (1Y, 1M, 1C, 1BK) which is a drum-type electrophotographic photosensitive member as a carrier is provided.

  Image forming process means are arranged around the photosensitive drum 1 (1Y, 1M, 1C, 1BK). 10 and 11 show only an exposure device 3 (3Y, 3M, 3C, 3BK) that forms an electrostatic latent image on the photosensitive drum 1 (1Y, 1M, 1C, 1BK) based on the image information. In addition, there are other charging devices that uniformly charge the surface of the photosensitive drum 1 (1Y, 1M, 1C, 1BK), and toner on the electrostatic latent image on the photosensitive drum 1 (1Y, 1M, 1C, 1BK). A developing device or the like for arranging a toner image to form a toner image is disposed.

  Further, below the four image forming portions PY, PM, PC, and PBK, that is, below the photosensitive drum 1 (1Y, 1M, 1C, 1BK), the photosensitive drum 1 (1Y, 1M, 1C, 1BK). An intermediate transfer unit 5 is installed as a second image carrier to which the upper toner image is transferred. In this embodiment, the intermediate transfer unit 5 has an intermediate transfer belt 5a wound around rollers 51 and 52, and the intermediate transfer belt 5a rotates clockwise. Further, transfer rollers 5dY, 5dM, 5dC, and 5dBK are arranged facing the respective photosensitive drums 1 (1Y, 1M, 1C, and 1BK) from the inside of the intermediate transfer belt 5a.

  The intermediate transfer belt 5a forms one color developed image on the intermediate transfer belt 5a, and then transfers the developed image to the transfer material P supplied from the transfer material storage box 6 at the transfer position E.

  Further, the transfer material P is conveyed to the fixing device 8 and melts and fixes the toner image on the transfer material P to the transfer material P using heat and pressure. The transfer material P that has passed through the fixing device 8 is discharged to the discharge tray 10 by the transport unit 9.

  As described above, in the conventional color image forming apparatus, from the upper position to the lower position of the image forming apparatus, the exposure device 3 and the image carrier 1 (process means such as a charging device and a developing device around the image carrier 1). The intermediate transfer unit 5 and the transfer material storage box 6 are arranged in this order. A fixing device 8 is disposed downstream of the transfer material P.

  In the color image forming apparatus of this example, as shown in FIG. 11, access to the inside of the image forming apparatus for repairing or replacing the intermediate transfer belt 5a or jam processing is formed at the top of the image forming apparatus. This is done by opening the access door 100. In addition, the exposure apparatus 3 is provided integrally with the access door 100.

  On the other hand, on the image forming apparatus main body 200 side, the image carrier 3, process means around the image carrier, and further the intermediate transfer unit 5 remain fixed.

  Accordingly, when the intermediate transfer unit 5 is detached from the image forming apparatus main body for repairing or replacing the intermediate transfer belt 5a, or for jam processing, the process of the image carrier 3 and the process around the image carrier is performed by the user. It is indispensable to remove the means once from the image forming apparatus main body 200.

Thus, in the conventional color image forming apparatus, the user has to perform complicated operations.
JP 2001-272864 A

An object of the present invention, the intermediate transfer member by the user, as well as the image bearing member, to facilitate access to the image forming section and the like developing device, repair or replacement of the intermediate transfer member, or jam during jam It is an object of the present invention to provide a color image forming apparatus with greatly improved processability and operability.

The above object is achieved by a color image forming apparatus according to the present invention. In summary, the present invention includes an intermediate transfer member having the toner image and a plurality of image bearing members formed, toner images on the plurality of provided along the image bearing member of the plurality of image bearing members are sequentially transferred An intermediate transfer unit, and a door provided to be openable and closable with respect to the apparatus main body. The intermediate transfer unit is detachably attached to the door, and the plurality of images are opened by opening the door. In the color image forming apparatus in which the space between the carrier and the intermediate transfer member is opened ,
A pressing member that is provided on the door and presses the intermediate transfer unit; and an abutting member that is provided on the apparatus main body side and that abuts the intermediate transfer unit. The intermediate transfer unit is pressed by the pressing member. Further, the movement is restricted in the pressing direction so that the door is loosely attached to the door, and the intermediate transfer unit is abutted against the abutting member and is pressed by the pressing member by closing the door. Thus , the color image forming apparatus is characterized in that the intermediate transfer unit is positioned with respect to the apparatus main body .

According to the present invention, the following effects can be obtained.
(1) The intermediate transfer unit can be easily detached from the door ( access door ) provided in the image forming apparatus main body, and maintenance and replacement of the intermediate transfer unit can be easily achieved by a simple operation.
(2) By providing access to the intermediate transfer unit from the same direction as the transfer material conveyance, if one access door is opened, an image forming unit including an image carrier, a developing device, etc., and an intermediate transfer member are provided. The intermediate transfer unit and the transfer material transport unit are exposed, and the intermediate transfer unit, the image carrier, the developing device, and the transfer material transport path are highly visible to the user. Access to the provided image forming unit and intermediate transfer unit is easy, and they can be exchanged. At the same time, the transfer material jam handling ability is also improved.
(3) When the access door is changed from the open state to the closed state, the intermediate transfer unit attached in a floating state to the access door by the pressing member is automatically positioned, and the operability is improved. Therefore, a high-quality image can be obtained over a long period of time by simple maintenance without complicated operations for the user. As a result, the usability of the color image forming apparatus is improved.

  The color image forming apparatus according to the present invention will be described below in more detail with reference to the drawings.

Example 1
FIG. 1 is a cross-sectional view showing a configuration of a color image forming apparatus using an electrophotographic system according to an embodiment of the present invention. The color image forming apparatus A of the present embodiment is a laser beam printer that can form a four-color full-color image.

  According to this embodiment, the color image forming apparatus A includes four image forming units PY, PM, PC, and PBK, and each of the image forming units PY, PM, PC, and PBK serves as a first image carrier. A photosensitive drum 1 (1Y, 1M, 1C, 1BK), which is a drum type electrophotographic photosensitive member. The photosensitive drum 1 (1Y, 1M, 1C, 1BK) is rotationally driven counterclockwise in this embodiment by a driving unit (not shown).

  Around the photosensitive drum 1 (1Y, 1M, 1C, 1BK), a charging device 2 (2Y, 2M, 2C, 2BK) for uniformly charging the surface of the photosensitive drum 1 (1Y, 1M, 1C, 1BK), image information An exposure device 3 (3Y, 3M, 3C, 3BK) that forms an electrostatic latent image on the photosensitive drum 1 (1Y, 1M, 1C, 1BK) by flashing a light source, for example, laser light or LED light based on Developing device 4 (4Y, 4M, 4C, 4BK) for developing toner 4 by attaching toner to the electrostatic latent image on photosensitive drum 1 (1Y, 1M, 1C, 1BK), photosensitive drum 1 (1Y, 1M, 1C, 1BK) is provided with an intermediate transfer unit 5 as a second image carrier to which the toner image is transferred. In this embodiment, the intermediate transfer unit 5 has a transfer belt 5a wound around rollers 51, 52, and 53, and the transfer belt 5a rotates clockwise. Further, transfer rollers 5dY, 5dM, 5dC, and 5dBK are arranged facing the photosensitive drums 1 (1Y, 1M, 1C, and 1BK) from the inside of the transfer belt 5a.

  Each of the image forming units PY, PM, PC, and PBK is provided with a developing device 4 (4Y, 4M, 4C, 4BK) that is integrally provided with the photosensitive drum 1 (1Y, 1M, 1C, 1BK) vertically. They are arranged side by side. Accordingly, the intermediate transfer belt 5a of the intermediate transfer unit 5 moves vertically from below to above on the side facing the photosensitive drum 1 (1Y, 1M, 1C, 1BK).

  Each developing device 4 (4Y, 4M, 4C, 4BK) has a developer accommodating portion 4a that accommodates four color toners of yellow Y, magenta M, cyan C, and black BK. Each developer accommodating portion 4a is provided with a developing roller 4b as a developer carrying member that carries toner as a developer and conveys it to a developing portion facing the photosensitive drum 1. Accordingly, the electrostatic latent image on the photosensitive drum 1 is developed by the developing roller 4b.

  The developed images (that is, toner images) formed on the respective photosensitive drums 1 (1Y, 1M, 1C, 1BK) are transferred to the intermediate transfer belt 5a by transfer rollers 5 (5dY, 5dM, 5dC, 5dBK) arranged opposite to each other. Each color is sequentially transferred and four color images are superimposed. Thereby, one full-color developed image electrostatically attracted is formed on the intermediate transfer belt 5a.

  The intermediate transfer belt 5a further rotates to the transfer position E where the developed image is transferred onto the transfer material P after one color developed image is formed on the intermediate transfer belt 5a.

  The transfer material P in the transfer material storage box 6 is supplied to the transfer position E by the paper feeding / conveying device 7 at a predetermined timing. At the transfer position E, transfer means 5b for generating a transfer bias with respect to the intermediate transfer belt 5a is provided on the opposite side of the intermediate transfer belt 5a with the transfer material P interposed therebetween.

  According to this embodiment, the developed image on the intermediate transfer belt 5a is collectively transferred to the transfer material P using the electrostatic attraction force at the transfer position E described above.

  Further, the transfer material P is conveyed to the fixing device 8 in order to fix the toner image on the transfer material P. In the fixing device 8, the toner on the transfer material P is melted and fixed using heat and pressure. The transfer material P that has passed through the fixing device 8 is discharged to the discharge tray 10 by the transport unit 9.

  In the present exemplary embodiment, the transfer path P of the transfer material P includes a transfer path 20A from the transfer material storage unit 6 to the transfer position E, a transfer path 20B from the transfer position E to the fixing device 8, and a discharge from the fixing device 8. A conveyance path 20 </ b> C to the tray 10 is configured.

  Next, the characteristic configuration and operation mode of the color image forming apparatus of the present invention will be described with reference to FIGS.

  2 to 4 schematically show a schematic configuration of the color image forming apparatus of the present embodiment. FIG. 2 is a schematic diagram showing the configuration of the color image forming apparatus shown in FIG. FIG. 3 shows a state where the access door 100 as an intermediate transfer unit holding unit holding the intermediate transfer unit 5 is opened. FIG. 4 shows a state where the intermediate transfer unit 5 detachably held on the access door 100 is detached from the access door 100.

  In other words, according to the present invention, the intermediate transfer unit 5 is detachably attached to the access door 100. By opening and closing the access door 100, the intermediate transfer unit 5 is in an inoperative state (the state shown in FIG. 2). It is possible to move between operating states (state of FIG. 3). That is, when the access door 100 is in the closed state, the intermediate transfer unit 5 is set in the activated state, and when the access door 100 is brought into the opened state, the intermediate transfer unit 5 is inactivated.

  More specifically, according to the present embodiment, the access door 100 has an outer lower end attached to a support member 201 provided in the image forming apparatus main body 200 so as to be swingable by a support shaft (fulcrum) 202. . The intermediate transfer unit 5 is detachably attached to the access door 100 using attachment means (not shown) such as a guide rail. Such mounting means are well known to those skilled in the art and will not be described further.

  According to this embodiment, as can be understood from FIG. 3, the support shaft 202 below the image forming apparatus main body 200 is used as the rotation center of the access door 100. Accordingly, the access door 100 is opened by rotating clockwise around the fulcrum serving as the support shaft 202, that is, in the same clockwise direction as the transfer material conveyance of the intermediate transfer belt 5a.

  When the access door 100 is rotated about the support shaft 202, the intermediate transfer unit 5 includes the photosensitive drum 1 (1Y, 1M, 1C, 1BK) in which the intermediate transfer belt 5a is arranged in the vertical direction. ) And the boundary.

  Accordingly, the transfer material P is jammed in the transfer route 20 of the transfer material P in the transfer route 20A from the transfer material storage 6 to the transfer position E and in the transfer route 20B from the transfer position E to the fixing device 8. When this occurs, the visibility of the user is ensured for all of the transport path 20 by opening the access door 100 as described above. Therefore, the user can easily perform jam processing.

  FIG. 4 shows a state where the intermediate transfer unit 5 is removed from the access door 100 by pulling out the intermediate transfer unit 5 in the arrow X direction. As is apparent from FIG. 4, when the access door 100 is opened, the user can immediately recognize the intermediate transfer unit 5.

  Further, since the intermediate transfer unit 5 is separated and independent from the image carrier 1 and the developing device 4 attached to the apparatus main body 200 side, the intermediate transfer unit is pulled out from the access door 100 and the intermediate transfer unit 5 is removed. Is easy to replace.

  Next, a description will be given of the automatic positioning of the intermediate transfer unit 5 with respect to the apparatus main body 200 by the operation of the access door 100.

  According to this embodiment, the intermediate transfer unit 5 is attached to the access door 100 by being attached to the access door 100 by a mounting means (not shown) such as a guide rail and pressed against the access door 100 by the pressing members 14 and 15. It is done. That is, according to the present embodiment, the intermediate transfer unit 5 is not fixed with screws or the like but is attached in a so-called floating state (floating state).

  According to this embodiment, the intermediate transfer unit 5 is provided with the abutting portions 16 and 17, and the abutting member 18 corresponding to the abutting portions 16 and 17 is provided on the image forming apparatus main body 200 side. 19 is arranged.

  Therefore, as shown in FIG. 2, when the user performs an operation of closing the access door 100, the abutting members 18 and 19 provided in the image forming apparatus main body have the abutting portions 16 and 17 on the intermediate transfer unit 5 side. And abutment positions G and H, respectively.

  As the access door 100 is further closed, the pressing members 14 and 15 as elastic members are elastically deformed, and when the access door 100 is completely closed, the positioning with respect to the image carrier 1 and the transfer position E is automatically performed. Done. Therefore, the user can obtain a high-quality image.

  The case where the access door 100 is closed and the intermediate transfer unit 5 is positioned with respect to the image carrier 1 and the transfer position E will be described with reference to FIG.

When the access door 100 is closed, the pressing members 14 and 15 provided in the access door 100 press the intermediate transfer unit 5. When the force at that time and F _14, in a system of x-y as shown in FIG. 5, can be divided force F _14x and F _14y.

Similarly, each image which acts a force pressing member 15 presses the intermediate transfer unit 5 and F _15, 4 pieces of image forming portions PY, PM, PC, each of the primary transfer unit 5dBK in PBK, 5Dc, 5 dm, the 5dY The reaction forces from the supports 1BK, 1C, 1M, and 1Y are F _5dBK , F _5dC , F _5dM , F _5dY , and the reaction force from the secondary transfer unit 5b to the intermediate transfer unit 5 is F _5b .

Here, since the intermediate transfer unit 5 abuts against the image bearing member 1 and the transfer position E, if similarly the force component as F _14, the _{x-direction, F 14x + F 15x> F} 5dBK + F 5dC + F 5dM With _{respect to} + F _5dY + F _5bx and the y direction, it is necessary that a relationship of F _14y + F _15y > F _5by is _satisfied .

  That is, the pressing force of the pressing members 14 and 15 needs to be larger than the reaction force generated between the intermediate transfer unit 5 and the image forming apparatus main body 200 when the intermediate transfer unit 5 is positioned on the image forming apparatus main body 200. .

  6 and 7 show a state in which the access door 100 is in an open state and the intermediate transfer unit 5 is attached to the access door 100. FIG. FIG. 7 is a view of FIG. 6 as viewed from the direction of the arrow (a).

  In attaching the intermediate transfer unit 5 to the access door 100, at least one member 23 protruding from the intermediate transfer unit 5 is inserted into the access door 100 on one side of the access door 100. On the opposite side of the access door 100, a protruding portion 25 of a slidable lock member 21 as a fixing member attached to the access door 100 is in contact with the lock member receiving portion 22 of the intermediate transfer unit 5. The intermediate transfer unit 5 is locked with appropriate play and play with respect to the access door 100.

  With such a configuration, the intermediate transfer unit 5 is configured not to be detached from the door 11 even though the intermediate transfer unit 5 is pressed from the access door 100 by the pressing members 14 and 15 to be in a floating state. . Further, the intermediate transfer unit 5 is provided with handle portions 24 on both side surfaces thereof so that the user can reliably handle with both hands.

  8 and 9 show a state when the intermediate transfer unit 5 is removed from the opened access door 100. FIG. FIG. 9 is a view of FIG. 8 as seen from the direction of the arrow (a).

  When the user simply slides the lock member 21 in the direction of arrow X in the figure, the intermediate transfer unit 5 is unlocked from the access door 100, and the intermediate transfer unit 5 can be removed in the direction of arrow Y in the figure.

  When the user removes the intermediate transfer unit 5 for repair or replacement and then attaches it again, the reverse operation is sufficient.

  With the above configuration, usability and maintenance of the image forming apparatus are improved.

1 is a cross-sectional view illustrating a configuration of an embodiment of a color image forming apparatus according to the present invention. 1 is a schematic diagram showing a configuration of an embodiment of a color image forming apparatus according to the present invention, showing a state in which an access door is closed. 1 is a schematic diagram showing the configuration of an embodiment of a color image forming apparatus according to the present invention, showing a state where an access door is opened. FIG. 1 is a schematic diagram illustrating a configuration of an embodiment of a color image forming apparatus according to the present invention, and illustrates a state in which an intermediate transfer unit is removed while an access door is opened. FIG. 2 is a schematic diagram illustrating a configuration of an embodiment of a color image forming apparatus according to the present invention, and is a diagram for explaining positioning of an intermediate transfer unit with respect to an image carrier and a transfer position. In the color image forming apparatus according to the present invention, the intermediate transfer unit is locked to the access door while the access door is open. In the color image forming apparatus according to the present invention, the intermediate transfer unit is locked to the access door while the access door is open. In the color image forming apparatus according to the present invention, the intermediate transfer unit is unlocked from the access door while the access door is open. In the color image forming apparatus according to the present invention, the intermediate transfer unit is unlocked from the access door while the access door is open. In the conventional color image forming apparatus, the access door is closed. In the conventional color image forming apparatus, the access door is shown open.

Explanation of symbols

1 Photosensitive drum (image carrier)
2 Charging device 3 Exposure device 4 Developing device 5 Intermediate transfer unit 5a Transfer belt (intermediate transfer member)
14, 15 Press member 16, 17 Abutting portion 18, 19 Abutting member 20 Transfer material conveyance path 21 Lock member (adhering member)
22 Lock member receiving portion 23 Projecting member 24 Handle portion 25 Projecting portion 100 Access door (intermediate transfer unit holding means)
200 Image forming apparatus main body 201 Support shaft (fulcrum)

Claims (1)

An intermediate transfer unit including the intermediate transfer member and a plurality of image bearing members, toner images on the plurality of provided along the image bearing member of the plurality of image bearing members are sequentially transferred to the toner image is formed, A door provided to be openable and closable with respect to the apparatus main body, the intermediate transfer unit is detachably attached to the door, and the plurality of image carriers and the intermediate transfer member are opened by opening the door. In the color image forming apparatus where the space is opened ,
A pressing member that is provided on the door and presses the intermediate transfer unit; and an abutting member that is provided on the apparatus main body side and that abuts the intermediate transfer unit. The intermediate transfer unit is pressed by the pressing member. Further, the movement is restricted in the pressing direction so that the door is loosely attached to the door, and the intermediate transfer unit is abutted against the abutting member and is pressed by the pressing member by closing the door. Accordingly, the intermediate transfer unit is positioned with respect to the apparatus main body .

Images