JP7250622B2 - image forming device - Google Patents

Description

The present invention relates to an image forming apparatus that forms an image by an image forming process using toner, and more particularly to an image forming apparatus in which a transfer unit for transferring a toner image onto a recording material is detachable from the main body of the apparatus. be.

2. Description of the Related Art An increasing number of image forming apparatuses that form images in an image forming process using toner (dry toner) allow users to replace consumables and units for the purpose of reducing running costs. In such an image forming apparatus, consumables and units to be replaced are sometimes provided with an operation section such as a handle that a user actively touches. Toner scattered or floating (herein simply referred to as "scattering toner") inside the main body of the image forming apparatus (herein also referred to as "inside the machine") is placed on the operation section such as the handle. Adherence may stain the user's hands.

As a means for reducing contamination in the machine caused by toner scattered from a developing device or a photosensitive drum of an image forming unit, a configuration is known in which the toner is collected by suction. Japanese Patent Application Laid-Open No. 2002-200003 discloses a configuration in which a duct having a plurality of intake ports along the direction of the rotational axis of the photosensitive drum is provided downstream of the developing device with respect to the rotational direction of the photosensitive drum.

JP-A-11-161019

However, in the configuration described in Japanese Patent Application Laid-Open No. 2002-200010, an intake mechanism for sucking the scattered toner is provided in the vicinity of the developing device, which is the source of the scattered toner. In this case, in order to suck the scattered toner from the developing device and the photosensitive drum, it is necessary to provide a duct over substantially the entire rotation axis direction of the photosensitive drum. In addition to providing such a suction mechanism, in order to enable the attachment/detachment of an image forming unit having a developing device, a photosensitive drum, etc., and a transfer unit having an intermediate transfer belt, etc., the detachable unit is It is necessary to provide an area to avoid the duct. As a result, the cross section of the image forming unit increases, leading to complication and enlargement of the image forming apparatus.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image forming apparatus which has a simple configuration that is advantageous for simplification and miniaturization of the configuration, and which is capable of suppressing scattering toner from adhering to the handle portion of the transfer unit. be.

The above object is achieved by an image forming apparatus according to the present invention. In summary, a typical configuration of the present invention is an image forming apparatus that forms an image using toner, which includes an image carrier, a developing member that supplies toner to the image carrier, and a developing device that forms a toner image by attaching toner to the formed electrostatic image; a transfer unit that is detachable from an apparatus main body of the image forming apparatus, the transfer unit having a rotatably movable conveying body that carries and conveys a recording material; an inner portion facing an end portion of a transfer unit, wherein the transfer unit is disposed above the image carrier in the direction of gravity, has a handle portion at the end portion in the width direction, and includes the inner portion. has a wall positioned above the image carrier and below the lowermost part of the handle with respect to the gravitational direction and protruding toward the end of the transfer unit along the width direction. The wall portion overlaps the handle portion in the width direction and is formed so as not to reach the position of the end portion facing the inner portion of the conveying body. The image forming apparatus is characterized in that it is formed so as to cover a range of 50% or more of the width of the handle portion with respect to a direction substantially perpendicular to the direction of gravity when viewed substantially parallel to.

According to the present invention, it is possible to suppress scattering toner from adhering to the handle portion of the transfer unit with a simple configuration that is advantageous for simplification and miniaturization of the configuration.

1 is a schematic cross-sectional view of an image forming apparatus; FIG. 2 is a schematic cross-sectional view of an image forming unit; FIG. 3A and 3B are a schematic perspective view of a transfer unit and a schematic diagram of an example of a handle. FIG. FIG. 10 is a schematic right side view showing a process cartridge replacement method; FIG. 10 is a schematic front side view showing a method of exchanging the transfer unit; 3A and 3B are schematic front and right side views of the image forming apparatus for explaining a toner scattering path inside the machine; FIG. 1A and 1B are schematic front and right side views of an image forming apparatus according to Embodiment 1; FIG. It is a schematic diagram for demonstrating the installation range of a wall part. 2A and 2B are schematic front and right side views of an image forming apparatus according to a second embodiment; FIG. 10A and 10B are schematic front and right side views of an image forming apparatus according to Example 3; FIG.

Hereinafter, the image forming apparatus according to the present invention will be described in more detail with reference to the drawings.

[Example 1]
1. 1. Overall Configuration and Operation of Image Forming Apparatus FIG. 1 is a sectional view of an image forming apparatus 100 of this embodiment. The image forming apparatus 100 of this embodiment is a tandem type multifunction machine (having functions of a copier, a printer, and a facsimile machine) that employs an intermediate transfer system and is capable of forming a full-color image using an electrophotographic system. be. In the following description, regarding the image forming apparatus 100 and its elements, the front side of the paper surface of FIG. The depth direction (front-to-rear direction) connecting the "" side and the "rear" side is substantially parallel to the rotation axis direction of the photosensitive drum 1 and the supporting rollers of the intermediate transfer belt 7. Further, the image forming apparatus 100 and elements thereof. , "left" and "right" refer to left and right when the image forming apparatus 100 is viewed from the front side, and regarding the image forming apparatus 100 and its elements, "top (upper, upper) ", "Lower (lower, lower)" means "upper (upper, upper)" and "lower (lower, lower)" in the direction of gravity (vertical direction).However, only directly above and directly below is intended to include above and below a horizontal plane passing through the element or location of interest.

The image forming apparatus 100 has an apparatus main body 110 . An image reading section 120 is provided above the apparatus main body 110 to read a document sent by an automatic document feeder 121 or a document placed on a platen glass 122 as a document table. The apparatus main body 110 includes an image forming unit 111, a feeding device 112 for feeding a recording material (sheet, transfer material) S such as recording paper to the image forming unit 111, a manual feeding unit 113, a control unit 114, and the like. It is The image forming section 111 is provided with a laser scanner unit 3, a process cartridge 10, a transfer unit 17, a toner bottle 12, a fixing device 20, and the like. The feeding device 112 includes a plurality of storages 13 as storage units for storing the recording materials S, which are detachable from the apparatus main body 110, and feeding means for feeding the recording materials S stored in the storages 13. A pickup roller 14 and the like are provided. A manual feeding unit 113 is provided on the right side of the apparatus main body 110 so as to be openable and closable. A feeding roller 16 or the like is provided as a feeding means. When the manual feeding unit 113 is used, the feeding tray 15 is opened and protruded to a position where the recording material S can be fed. The recording material S is set and fed. A control unit 114 controls each unit of the image forming apparatus 100 .

The image forming apparatus 100 of this embodiment includes four stations 11Y and 11M for forming yellow (Y), magenta (M), cyan (C), and black (K) images in the image forming unit 111, respectively. , 11C, 11K. Elements having the same or corresponding functions or configurations in the stations 11Y, 11M, 11C, and 11K are denoted by omitting Y, M, C, and K at the end of the code indicating that they are elements for one of the colors. , may be comprehensively described. FIG. 2 is a schematic cross-sectional view showing one station 11 as a representative. In this embodiment, the station 11 includes a photosensitive drum 1, a charging roller 2, a laser scanner unit (exposure device) 3, a developing device 4, a primary transfer roller 5, a drum cleaning device 6, etc., which will be described later. . Further, in this embodiment, in each station 11, the photosensitive drum 1, the charging roller 2 as a process means acting on the photosensitive drum 1, the developing device 4 and the drum cleaning device 6 are integrally formed as a process cartridge 10. has been made The process cartridge 10 is detachable from the apparatus main body 110, as will be described later in detail. The drum unit including the photosensitive drum 1 and the developing unit including the developing device 4 may be individually detachable from the apparatus body 110 .

Next, an image forming operation in the image forming apparatus 100 of this embodiment will be described. Here, a case of operating as a copier will be described as an example. When an image reading signal is output from the control section 114 provided in the apparatus main body 110 to the image reading section 120, the image reading section 120 reads an image. The image reading unit 120 converts the optically read image information of the document into an electric signal and sends the electric signal to the image forming unit 111 . In the image forming unit 111, a photosensitive drum 1, which is a drum-shaped (cylindrical) photosensitive member (electrophotographic photosensitive member) as an image bearing member, is rotationally driven in the clockwise direction in FIGS. . The surface of the rotating photosensitive drum 1 is uniformly charged to a predetermined potential with a predetermined polarity (negative polarity in this embodiment) by a charging roller 2 which is a roller-shaped charging member as charging means. The charged surface of the photosensitive drum 1 is scanned and exposed by a laser scanner unit 3 to form an electrostatic image (electrostatic latent image) on the photosensitive drum 1 . The laser scanner unit 3 irradiates the photosensitive drum 1 with laser light corresponding to the electrical signal sent from the image reading section 120 . The electrostatic image formed on the photosensitive drum 1 is developed (visualized) by supplying toner as a developer by a developing device 4 as developing means, and a toner image is formed on the photosensitive drum 1 . The developing device 4 includes a developing container 4b containing a developer, and a developer carrying member (developing member) that carries the developer contained in the developing container 4b and conveys it to a portion (developing portion) facing the photosensitive drum 1. ) as a developing roller 4a.

A transfer unit 17 is arranged so as to face the four photosensitive drums 1 . The transfer unit 17 has an intermediate transfer belt 7 which is an intermediate transfer member formed of an endless belt so as to face the four photosensitive drums 1 . The intermediate transfer belt 7 is stretched over a plurality of support rollers (stretching rollers) and stretched with a predetermined tension. The intermediate transfer belt 7 circulates (rotates) in the counterclockwise direction in FIG. 1 by rotating a drive roller, which is one of the plurality of support rollers. On the inner circumferential surface side of the intermediate transfer belt 7 , primary transfer rollers 5 that are roller-shaped primary transfer members as primary transfer means are arranged corresponding to the respective photosensitive drums 1 . The primary transfer roller 5 is urged in a direction toward the photosensitive drum 1 via the intermediate transfer belt 7 to form a primary transfer portion N1 where the photosensitive drum 1 and the intermediate transfer belt 7 are in contact with each other. The intermediate transfer belt 7 is an example of a rotatably movable conveying member that bears and conveys a toner image transferred from an image bearing member. The toner image formed on the photosensitive drum 1 as described above is primarily transferred onto the rotating intermediate transfer belt 7 by the action of the primary transfer roller 5 at the primary transfer portion N1. During the primary transfer, a primary transfer bias having a polarity opposite to the normal charging polarity of the toner (the charging polarity during development) is applied to the primary transfer roller 5 . For example, when forming a full-color image, the toner images formed on the respective photosensitive drums 1Y, 1M, 1C, and 1K are sequentially primarily transferred onto the intermediate transfer belt 7 so as to be superimposed.

On the outer peripheral surface side of the intermediate transfer belt 7, a roller-shaped secondary transfer member 2 as a secondary transfer means is provided at a position facing a secondary transfer inner roller 19, which is one of a plurality of support rollers. A secondary transfer outer roller 29 is arranged. The secondary transfer outer roller 29 is urged in a direction toward the secondary transfer inner roller 19 via the intermediate transfer belt 7, and moves the secondary transfer portion N2 where the intermediate transfer belt 7 and the secondary transfer outer roller 29 are in contact with each other. Form. The toner image formed on the intermediate transfer belt 7 as described above is nipped between the intermediate transfer belt 7 and the secondary transfer outer roller 29 by the action of the secondary transfer outer roller 29 at the secondary transfer portion N2. Secondarily transferred onto the conveyed recording material S. During secondary transfer, a secondary transfer bias having a polarity opposite to the normal charging polarity of the toner is applied to the secondary transfer roller 29 . Here, when a feeding signal is output from the control unit 114 to the feeding device 112 , the recording material S is fed out from the storage 13 by the pickup roller 14 . When a feeding signal is output from the control unit 114 to the manual feeding unit 113 , the recording material S is fed from the feeding tray 15 by the feeding roller 16 . After that, the sent recording material S is skew-corrected by a skew-correcting unit including a pair of registration rollers 18, etc., and then sent to the secondary transfer unit N2 in time with the toner image on the intermediate transfer belt 7. be done.

The recording material S onto which the toner image has been transferred is conveyed to a fixing device 20 as fixing means. The fixing device 20 fixes (melts, fixes) the toner image to the recording material S by heating and pressurizing the recording material S bearing the unfixed toner image. The recording material S on which the toner image is fixed is discharged (output) by a discharge roller 21 to a discharge tray 22 provided outside the apparatus main body 110 (here, also referred to as “outside”).

On the other hand, the toner remaining on the photosensitive drum 1 after the primary transfer (primary transfer residual toner) is removed from the photosensitive drum 1 and collected by a drum cleaning device 6 as photoreceptor cleaning means. Further, the toner remaining on the intermediate transfer belt 7 after the secondary transfer (secondary transfer residual toner) is removed from the intermediate transfer belt 7 and collected by a belt cleaning device 24 as intermediate transfer body cleaning means. The transfer residual toner collected by the drum cleaning device 6 and the belt cleaning device 24 is sent to and stored in a collection container 23 .

FIG. 3A is a schematic perspective view of the transfer unit 17. FIG. A plurality of support rollers of the intermediate transfer belt 7 provided in the transfer unit 17 are rotated by a unit frame 30, which is a frame of the transfer unit 17, via bearing members (not shown) at both ends in the rotation axis direction. supported as possible. The unit frame 30 has side structures 31 at both ends in a direction substantially perpendicular to the moving direction of the surface of the intermediate transfer belt 7 (here, also referred to as “width direction”). Note that the side structure 31 may be composed of a single member or may be composed of a plurality of members. Further, in this embodiment, the side structure 31 on the both end sides is provided with a grip portion 32, a boss 33, and the like. The grip portion 32, the boss 33, etc. will be described later in more detail. In this embodiment, the side structure 31 is substantially symmetrical with respect to the center of the intermediate transfer belt 7 in the width direction. In this embodiment, the transfer unit 17 is detachable from the apparatus main body 110, as will be described later in detail. Further, in this embodiment, the transfer unit 17 is arranged above each photosensitive drum 1 with respect to the direction of gravity when it is attached to the apparatus main body 110 .

Further, in this embodiment, the image forming apparatus 100 has a fan 50 (see FIGS. 7A and 7B), which is a blowing means, as an airflow generating means for generating an air flow inside the apparatus body. In this embodiment, the fan 50 is mainly used to cool the recording material P after the toner image has been fixed by the fixing device 20, or to exhaust the air heated by the fixing device 20 from the inside of the apparatus to the outside of the apparatus. is established for The airflow generating means may mainly discharge air from the inside of the device main body 110 to the outside, or may mainly draw air into the machine from the outside. In this embodiment, the fixing device 20 is arranged above the transfer unit 17 with respect to the direction of gravity. In this embodiment, the fan 50 is arranged above the transfer unit 17 with respect to the direction of gravity. More specifically, in this embodiment, a plurality (two in this embodiment) of the fans 50 are arranged side by side in the front-rear direction of the image forming apparatus 100 at positions overlapping the fixing device 20 in the direction of gravity. In this embodiment, the fan 50 is operated at least during image forming operations to generate airflow within the machine. The airflow generated by the fan 50 will be described in more detail later. In this embodiment, the image forming apparatus 100 further includes a fan (not shown) for cooling the developing device 4, which is an air blower, as an airflow generator.

2. Attachment and Detachment of Unit Next, attachment and detachment of a replaceable unit in the image forming apparatus 100 of this embodiment will be described. In this embodiment, the process cartridge (image forming unit) 10 and the transfer unit 17 are assembled at predetermined positions with respect to the apparatus main body 110. However, by allowing the user to replace each unit, maintenance is facilitated. is enhanced.

FIG. 4 is a schematic right side view of the image forming apparatus 100, showing the internal configuration of the essential parts of the image forming apparatus 100 and a method of replacing the process cartridge 10. As shown in FIG. When the process cartridge 10 is replaced, the contact state of the intermediate transfer belt 7 against the photosensitive drum 1 due to the pressure of the primary transfer roller 5 is changed by the operation of the link (not shown). It is canceled by being moved in the detachment direction indicated by the arrow U in the middle. As a result, the process cartridge 10 can be removed from the front side of the apparatus main body 110 in the front direction indicated by the arrow F in FIG. Further, the process cartridge 10 is moved in the direction opposite to the arrow F in FIG. Thereafter, a link (not shown) moves the primary transfer roller 5 in the direction opposite to the arrow U in FIG. 7 are abutted. Accordingly, the image forming apparatus 100 can be brought into a state in which image formation is possible. A front door (not shown) is provided on the front side of the apparatus main body 110 so that the process cartridge 10 can be attached and detached. be done.

FIG. 5 is a schematic front side view of the image forming apparatus 100, showing the internal configuration of the main parts of the image forming apparatus 100 and a method of replacing the transfer unit 17. As shown in FIG. The transfer unit 17 is held by a front rail 26 as a support portion fixed to a front side plate (frame) 25 of the apparatus main body 110 and a rear rail 28 as a support portion fixed to a rear side plate (frame) 27 . be. Further, the transfer unit 17 is positioned by pressing the secondary transfer outer roller 29 toward the secondary transfer inner roller 19 via the intermediate transfer belt 7 . When the transfer unit 17 is replaced, the pressure of the secondary transfer outer roller 29 is released first, and the photosensitive drum 1 is pressed by the primary transfer roller 5 by the operation of the link (not shown) similar to that described above. The contact state of the intermediate transfer belt 7 with respect to is released. Next, in a state where the bosses 32 of the side structures 31 of the unit frames 30 at both ends in the width direction of the intermediate transfer belt 7 are placed on the guide portions 34 of the front rail 26 and the rear rail 28, the transfer unit 17 is moved. is moved in the right direction indicated by the arrow R in FIG. The transfer unit 17 is moved while the boss 32 is guided by the guide portion 34 . At this time, an operator such as a user can pull out the transfer unit 17 from the apparatus main body 110 by holding a pull-out handle (not shown) provided at the leading end of the transfer unit 17 in the pull-out direction. ing. Further, when the transfer unit 17 is pulled out from the apparatus main body 110 about halfway in the attachment/detachment (insertion/removal) direction, an operator such as a user moves the side structure 31 of the unit frame 30 at both ends in the width direction of the intermediate transfer belt 7 . The handle 32 provided in the can be grasped. An operator such as a user can move the transfer unit 17 to the outside of the apparatus main body 110 while holding the handle 32 . In this manner, the transfer unit 17 can be removed from the apparatus main body 110. FIG. When assembling a new transfer unit 17 to the apparatus main body 110, the transfer unit 17 can be attached to the apparatus main body 110 and positioned by performing the procedure in reverse to the removal. As described above, in this embodiment, the transfer unit 17 is moved in the horizontal direction of the image forming apparatus 100 to be attached to and detached from the apparatus body 110 . An openable/closable right door 115 is provided on the right side of the main body of the apparatus to allow attachment and detachment of the transfer unit 17. When the transfer unit 17 is attached and detached, the right door 115 is opened. The secondary transfer outer roller 29 is interlocked with the opening operation of the right door 115 to release the pressure applied to the secondary transfer inner roller 19 and retreat, and interlocked with the right door 115 closing operation, the secondary transfer inner roller 19 is closed. is pressed against to determine the position of the transfer unit 17 .

3. Toner Scattering Path Next, the toner scattering path inside the apparatus main body 110 (inside the machine) will be described. 6A is a schematic front side view of the image forming apparatus 100 of the comparative example, and FIG. 6B is a schematic right side view of the image forming apparatus 100 of the comparative example. The internal structure of the main part of 100 is shown. 6(a) and 6(b) show toner scattering paths in the machine when the wall portion 35 according to the present invention, which will be described later, is not provided. The image forming apparatus 100 of the comparative example shown in FIGS. 6A and 6B has substantially the same configuration as the image forming apparatus 100 of the present embodiment except that the wall portion 35 is not provided. Assume that there is

Most of the scattered toner is generated from the developing device 4 and the photosensitive drum 1 , especially the developing device 4 . For example, scattering toner is generated from the developing roller 4a rotating while holding the toner. Further, for example, at the end of the developing container 4b in the direction of the rotation axis of the developing roller 4a (here, also simply referred to as "the end of the developing device 4"), the toner is prevented from leaking from the developing container 4b. Scattered toner is generated from the sealing portion. Further, in the apparatus, an air flow A is generated by a fan 50 for cooling the recording material P after fixing the toner image by the fixing device 20 and a fan (not shown) for cooling the developing device 4 . Therefore, the scattered toner T generated on the developing roller 4 a and from the end of the developing device 4 as described above is carried by the airflow A directed toward the fan 50 . Here, as shown in FIGS. 6A and 6B, the fan 50 is positioned on the photosensitive drum 1 side (image carrier side) with respect to the transfer unit 17 when viewed substantially parallel to the width direction of the intermediate transfer belt 7 . ) toward the side opposite to the photosensitive drum 1 (that is, upward). In this case, as described above, the scattered toner T generated from the developing roller 4a and the end portions of the developing device 4 is deposited on both end portions of the intermediate transfer belt 7 in the width direction. (Side structure 31) and the inner part (front side plate 25, rear side plate 27) of apparatus main body 110 facing this, and carried upward by airflow A directed to fan 50. Here, the transfer unit 17 has a handle portion 32 at an end portion (side portion structure 31 ) in the width direction of the intermediate transfer belt 7 . Therefore, the scattering toner T adheres to the handle portion 32 of the transfer unit 17, particularly to the downward facing surface 32a of the handle portion 32 and the like. If toner adheres to the handle portion 32 in this manner, the user may touch it when replacing the transfer unit 17, and the user's hands may become soiled with toner.

3B and 3C are schematic diagrams showing examples of the handle portion 32, respectively. In each of FIGS. 3B and 3C, the upper diagram is a schematic cross-sectional view of the transfer unit 17 viewed along the attachment/detachment (insertion/removal) direction with respect to the apparatus main body 110, and the lower diagram is a cross-sectional view of the intermediate transfer belt 7. 1 is a schematic side view looking along; FIG. The grip portion 32 is assumed by the manufacturer of the image forming apparatus 100 (transfer unit 17 ), for example, to be gripped by an operator such as a user when attaching/detaching the transfer unit 17 . In general, the handle portion 32 has a shape (convex shape, concave shape) that can be clearly distinguished from the surrounding structure, and is configured so that an operator such as a user can easily recognize that it is a handle portion. However, the grip portion 32 may be configured so that an operator such as a user can easily recognize that it is a grip portion, for example, by making the material, color, pattern, etc. different from those of the surroundings. In the example shown in FIG. 3B, the handle portion 32 protrudes along the width direction of the intermediate transfer belt 7 from the surrounding structure toward the inner portion (the front side plate 25 and the rear side plate 27) of the apparatus main body 110. It is composed of ribs 32b. In the case of the example shown in FIG. 3B, it is assumed that an operator such as a user handles the transfer unit 17 by placing a finger on the lower surface 32a of the handle portion 32 formed by the protruding ribs 32b. In the example shown in FIG. 3C, the handle 32 extends along the width direction of the intermediate transfer belt 7 from the surrounding structure toward the inner side (the front side plate 25 and the rear side plate 27) of the apparatus main body 110. It is composed of a projecting edge 32c and a region surrounded by the edge 32c. In the example shown in FIG. 3C, an operator such as a user can handle the transfer unit 17 by placing a finger on the lower surface 32a of the upper edge 32c or the lower surface 32a of the lower edge 32c. is assumed. For example, in the case of the examples shown in FIGS. 3B and 3C, the scattered toner T is likely to adhere to the lower surface 32a of the handle portion 32 if the wall portion 35 according to the present invention, which will be described later, is not provided.

4. Wall part (shielding part)
Next, a configuration for suppressing adhesion of scattered toner to the handle portion 32 of the transfer unit 17 in this embodiment will be described. 7A is a schematic front side view of the image forming apparatus 100 of this embodiment, and FIG. 7B is a schematic right side view of the image forming apparatus 100 of this embodiment. The internal configuration of the essential parts of the forming apparatus 100 is shown.

As described above, the scattered toner T generated on the developing roller 4a or from the edge of the developing device 4 is carried by the airflow A. As shown in FIG. On the other hand, in this embodiment, the apparatus body 110 is provided with walls (shielding portions) 35 at positions blocking the path of the airflow A on both widthwise end sides of the intermediate transfer belt 7 . .

In this embodiment, the wall portion 35 is made up of a portion of each of the front rail 26 and the rear rail 28 . The wall portion 35 is positioned above the photosensitive drum 1 and below the lowest portion (lowermost surface 32a in this embodiment) of the handle portion 32 with respect to the direction of gravity. The wall portion 35 protrudes toward the end portion (side portion structure 31 ) of the transfer unit 17 along the width direction of the intermediate transfer belt 7 .

8A and 8B are schematic diagrams showing in more detail the range in which the wall portion 35 is provided, and FIG. 8A is a schematic cross-sectional view of the transfer unit 17 as seen along the attachment/detachment (insertion/removal) direction with respect to the apparatus main body 110. FIG. 8(b) is a schematic side view of the intermediate transfer belt 7 viewed along the width direction. With respect to the width direction of the intermediate transfer belt 7, the protrusion amount L1 of the wall portion 35 can sufficiently suppress the scattering toner T from adhering to the handle portion 32, and the transfer unit 17 when the intermediate transfer belt 7 is operated or the transfer unit 17 is attached or detached. The length is such that it does not come into contact with the 17 components. Specifically, the wall portion 35 overlaps the handle portion 32 in the width direction of the intermediate transfer belt 7 and faces the inner portion (the front side plate 25 and the rear side plate 27) of the apparatus main body 10. 7 is formed so as not to reach the position of the end 7a. The wall portion 35 is preferably formed so as to cover a range of 50% or more of the width G of the grip portion 32 in the width direction of the intermediate transfer belt 7, and is formed so as to cover a range of 80% or more. (It may be formed so as to cover the entire width G.). In this embodiment, it is formed so as to cover a range of 50% or more.

Further, the width L2 of the wall portion 35 is sufficient to prevent the scattered toner T from adhering to the grip portion 32 in the left-right direction (the direction substantially perpendicular to the direction of gravity when viewed substantially parallel to the width direction of the intermediate transfer belt 7). It is considered to be a length that can be suppressed to Specifically, the wall portion 35 is formed so as to cover a range of 50% or more of the width W of the handle portion 32 in the left-right direction. However, the amount of scattering toner T adhering to the grip portion 32 can be reduced as the range in which the wall portion 35 covers the grip portion 32 increases. Preferably, the wall portion 35 is formed so as to cover 80% or more of the width of the handle portion 32 in the left-right direction. In particular, in this embodiment, the wall portion 35 is formed so as to cover the full width W of the handle portion 32 in the left-right direction. More specifically, in this embodiment, the wall portion 35 extends from a portion of the leftmost Y process cartridge 10Y (a position covering a portion of the photosensitive drum 1Y) to the rightmost K process cartridge 10K in the horizontal direction. (position covering part of the photosensitive drum 1K). On the other hand, in many cases, it is sufficient if the wall portion 35 is formed so as to fit within the distance between both ends of the intermediate transfer belt 7 (within the distance between the ends 7b and 7b in FIG. 7A) in the horizontal direction. . In addition, with respect to the direction of gravity, the distance D between the lowest portion of the handle portion 32 and the uppermost portion of the wall portion 35 is preferably greater than 0 mm and 10 mm or less, and more preferably 3 mm or more and 5 mm or less. . In this embodiment, it is approximately 4 mm. If the distance D is not greater than 0 mm, the wall portion 35 may come into contact with the handle portion 32 and interfere with attachment/detachment of the transfer unit 17 . Also, if the distance D is too large, the wall 35 blocks the path of the airflow A, and the effect of causing the airflow A to bypass the vicinity of the handle 32 may be reduced.

As shown in FIGS. 7A and 7B, by providing the wall portion 35 , the path of the airflow A near the handle portion 32 is blocked by the wall portion 35 . As a result, most of the airflow A flows around the route passing near the handle 32 . Further, the scattered toner T carried by the airflow A passing near the handle portion 32 reaches the wall portion 35 before reaching the handle portion 32 . Therefore, most of the scattered toner T adheres to the wall portion 35, and the amount of the scattered toner T adhering to the handle portion 32 can be reduced.

As described above, according to the present embodiment, the scattered toner can be transferred to the handle portion 32 of the transfer unit 17 with a simple structure without increasing the cross section of the image forming section by providing a duct or the like in the image forming section. Adhesion can be suppressed. That is, according to the present embodiment, it is possible to suppress adhesion of the scattering toner T to the handle portion 32 of the transfer unit 17 with a simple configuration that is advantageous for simplification and miniaturization of the configuration.

In this embodiment, the wall portion 35 is made up of a portion of each of the front rail 26 and the rear rail 28, but may be made up of a portion of each of the front side plate 25 and the rear side plate 27, or the like. In other words, the wall portion 35 may be part of a member constituting a support portion that supports the transfer unit 17 provided inside the apparatus main body 110, or may be a part of the apparatus main body 110 that forms the inner portion. It may be configured as part of a frame.

[Example 2]
Another embodiment of the present invention will now be described. The basic configuration and operation of the image forming apparatus of this embodiment are the same as those of the image forming apparatus of the first embodiment. Accordingly, in the image forming apparatus of the present embodiment, elements having the same or corresponding functions or configurations as those of the image forming apparatus of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted. .

In this embodiment, the configuration of the wall portion (shielding portion) 35 is different from that in the first embodiment. In this embodiment, the range in which the wall portion 35 is provided is set with the process cartridge 10 as a reference.

9A is a schematic front side view of the image forming apparatus 100 of this embodiment, and FIG. 9B is a schematic right side view of the image forming apparatus 100 of this embodiment. The internal configuration of the essential parts of the forming apparatus 100 is shown. As described in the first embodiment, most of the scattered toner T is generated from the developing device 4 and the photosensitive drum 1, especially the developing device 4. FIG.

Therefore, in this embodiment, the wall portion 35 is provided corresponding to each process cartridge 10 so as to block the path of the airflow A that carries the scattered toner T generated from each process cartridge 10 . In particular, in this embodiment, a plurality of (four in this embodiment) wall portions 35Y, 35M, 35C, and 35K are provided corresponding to each process cartridge 10 respectively. In this embodiment, the width L2 ( L2y, L2m, L2c, and L2k) are set to a length that can sufficiently reduce the airflow A carrying the scattered toner T from each process cartridge. Specifically, each wall portion 35 is formed so as to cover a range equal to or larger than the width of each developing roller 4a provided in each developing device 4 in the left-right direction. However, the amount of scattering toner T adhering to the grip portion 32 can be reduced as the range covered by the wall portion 35 increases in addition to the width of the developing roller 4a. Particularly, in this embodiment, the developing roller 4a and the photosensitive drum 1 of each process cartridge 10 are arranged so that each wall portion 35 covers the entire width of each developing roller 4a provided in each developing device 4 in the horizontal direction. It is formed so as to cover the range between both ends (between the ends 10a, 10a in FIG. 9(a)) of the region that is formed.

In this embodiment, the positions of the walls 35 (35Y, 35M, 35C, and 35K) in the gravitational direction and the length L1 in the width direction of the intermediate transfer belt 7 are the same as in the first embodiment. Further, in this embodiment, each wall portion 35 (35Y, 35M, 35C, 35K) is composed of a part of the front rail 26 and the rear rail 28, respectively.

In this embodiment, the wall portion 35C provided corresponding to the process cartridge 10C for C, which is closest to the handle portion 32 in the left-right direction, has a position in the left-right direction and a width L2c corresponding to the handle described in the first embodiment. The conditions for the position and width W of the portion 32 are also satisfied.

As shown in FIGS. 9A and 9B, by providing each wall portion 35, the scattered toner T carried by the airflow A reaches the wall portion 35 before reaching the handle portion 32. As shown in FIGS. Therefore, most of the scattered toner T adheres to each wall portion 35, and the amount of the scattered toner T adhering to the grip portion 32 can be reduced.

As described above, according to this embodiment, the same effects as those of the first embodiment can be obtained. Further, according to the present embodiment, since the range in which the wall portion 35 is provided is set based on the source of the scattered toner T, depending on the path of the airflow A, the scattered toner T may reach the handle portion 32 more than in the first embodiment. adhesion can be suppressed.

In this embodiment, each wall portion 35 is composed of a part of each of the front rail 26 and the rear rail 28, but may be composed of a part of each of the front side plate 25 and the rear side plate 27, or the like.

Further, by extending the width direction of the wall portion 35 toward the path of the airflow A, the amount of the scattering toner T directed toward the handle portion 32 can be efficiently reduced. In this embodiment, a plurality of wall portions 35 are provided corresponding to each process cartridge 10, but the wall portions 35 corresponding to any number (or all) of the process cartridges 10 are continuous. You may have However, like the process cartridge 10Y for Y in this embodiment, the process cartridge is sufficiently far from the airflow A (or the fan 50 that is the source of the airflow A) and the amount of the scattered toner T carried by the airflow A is sufficiently small. It is not necessary to provide the wall portion 35 corresponding to 10Y. The wall portion 35 does not need to be provided at a location where it is unnecessary or sufficiently low in order to suppress adhesion of the scattering toner T to the grip portion 32 . In this way, when the image forming apparatus 100 has a plurality of developing devices 4 along the direction crossing the direction of gravity when viewed substantially parallel to the width direction of the intermediate transfer belt 7, the following can be done. . In other words, the wall portion 35 can be formed so as to cover a range that is equal to or greater than the width of the developing roller 4a provided in at least one developing device 4 among the plurality of developing devices 4 in the left-right direction. The at least one developing device 4 may be a single developing device 4 or a plurality of developing devices 4 including at least the developing device 4 closest to the handle portion 32 in the left-right direction among the plurality of developing devices 4 . Also, in this case, the wall portion 35 may consist of one continuous portion or a plurality of portions.

[Example 3]
Another embodiment of the present invention will now be described. The basic configuration and operation of the image forming apparatus of this embodiment are the same as those of the image forming apparatus of the first embodiment. Accordingly, in the image forming apparatus of the present embodiment, elements having the same or corresponding functions or configurations as those of the image forming apparatus of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted. .

In this embodiment, the configuration of the wall portion (shielding portion) 35 is different from that in the first embodiment. In this embodiment, the range in which the wall portion 35 is provided is set with the toner bottle 12 as a reference.

10A is a schematic front side view of the image forming apparatus 100 of this embodiment, and FIG. 10B is a schematic right side view of the image forming apparatus 100 of this embodiment. The internal configuration of the essential parts of the forming apparatus 100 is shown. The image forming apparatus 100 includes toner bottles 12 (12Y, 12M, 12C) as replenishment containers that are detachable from the apparatus body 110 and store toner to be replenished to the developing devices 4 (4Y, 4M, 4C, 4K). , 12K). In this embodiment, each toner bottle 12 is arranged above the transfer unit 17 with respect to the direction of gravity. Each toner bottle 12 can be replaced at any time by the user according to the consumption of toner in each developing device 4 . In this embodiment, each toner bottle 12 can be removed from the apparatus main body 110 by pulling it out toward the front of the image forming apparatus 100 . Therefore, when removing the toner bottle 12 from the apparatus main body 110 , an operator such as a user may touch the outer periphery of the toner bottle 12 . Therefore, it is also desired to suppress adhesion of the scattered toner T to the toner bottle 12 .

Therefore, in this embodiment, the wall portion 35 is provided so as to block the path of the airflow A to the toner bottle 12 whose outer periphery is stained with the scattered toner T carried by the airflow A. As shown in FIG. In this embodiment, the width L2 of the wall portion 35 in the left-right direction (the direction substantially perpendicular to the direction of gravity when viewed substantially parallel to the width direction of the intermediate transfer belt 7) is the width L2 of the wall portion 35 that conveys the scattered toner T to the toner bottle 12. It is set to a length that can sufficiently reduce the airflow A reaching the . Specifically, the wall portion 35 is formed so as to cover, in the left-right direction, a range equal to or larger than the width of the toner bottle 12 whose outer periphery is stained with the scattered toner T carried by the airflow A. As shown in FIG. At this time, like the toner bottle 12Y for Y in this embodiment, the position is sufficiently far from the airflow A (or the fan 50 that is the source of the airflow) and the amount of the scattered toner T carried by the airflow A is sufficiently small. The toner bottle 12 placed on the wall need not be covered with the wall portion 35 . The wall portion 35 may not be provided at locations where it is unnecessary or sufficiently low in order to suppress adhesion of the scattering toner T to the toner bottle 12 . In this way, when the image forming apparatus 100 has a plurality of toner bottles 12 along the direction crossing the direction of gravity when viewed substantially parallel to the width direction of the intermediate transfer belt 7, the following can be done. . That is, the wall portion 35 can be formed so as to cover a range equal to or greater than the width of at least one toner bottle 12 among the plurality of toner bottles 12 in the left-right direction. The at least one toner bottle 12 may be a single toner bottle or a plurality of toner bottles 12 including at least the toner bottle 12 closest to the handle portion 32 in the left-right direction among the plurality of toner bottles 12 . In this embodiment, one continuous wall portion covers the entire width of each of the toner bottles 12M, 12C, and 12K for C, M, and K, including the toner bottle 12K for K, which is closest to the grip portion 32 in the left-right direction. 35 is provided.

In this embodiment, the position of the wall portion 35 in the gravitational direction and the length L1 in the width direction of the intermediate transfer belt 7 are set in the same manner as in the first embodiment. Moreover, in this embodiment, the wall portion 35 is formed by a part of each of the front rail 26 and the rear rail 28 .

In this embodiment, the position and width L2 of the wall 35 in the left-right direction also satisfy the conditions for the position and width W of the handle 32 described in the first embodiment. Further, in this embodiment, the wall portion 35 includes the developing roller 4a described in the second embodiment with respect to the process cartridges 10M and 10C for M and C including the process cartridge 10C for C that is closest to the handle portion 32 in the left-right direction. Also satisfies the conditions of the position and the width L2 with respect to .

As shown in FIGS. 10A and 10B, by providing the wall portion 35, the scattered toner T carried by the airflow A reaches the wall portion 35 before reaching the handle portion 32 and the toner bottle 12. . Therefore, most of the scattered toner T adheres to the wall portion 35, and the amount of the scattered toner T adhering to the handle portion 32 and the toner bottle 12 can be reduced.

As described above, according to this embodiment, the same effects as those of the first embodiment can be obtained. Further, according to this embodiment, adhesion of the scattered toner T to the toner bottle 12 can be suppressed.

In this embodiment, the wall portion 35 is made up of a portion of each of the front rail 26 and the rear rail 28, but may be made up of a portion of each of the front side plate 25 and the rear side plate 27, or the like.

[others]
Although the present invention has been described with reference to specific examples, the present invention is not limited to the above-described examples.

In the above-described embodiments, the handle portion of the transfer unit is provided symmetrically with respect to the center of the intermediate transfer belt in the width direction, but the present invention is not limited to this. For example, when the positions and lengths of the handles on both ends in the width direction of the intermediate transfer belt are different in the left-right direction, or when the positions and lengths in the front-rear direction are different, the handles correspond to the respective handles. A wall may be formed according to the position and length.

Further, in the above-described embodiment, the handle portion is provided substantially at the center in the attachment/detachment direction (horizontal direction) of the transfer unit, but the present invention is not limited to this. Even if the grip portion is located at one end in the attachment/detachment direction of the transfer unit, the wall portion may be formed at a position and length corresponding to the grip portion.

Further, in the above-described embodiments, the transfer unit has the intermediate transfer belt as the carrier, but the present invention is not limited to this. 2. Description of the Related Art A direct transfer type image forming apparatus is provided with a recording material carrying belt, for example, an endless belt, as a conveying member capable of carrying and conveying a recording material onto which a toner image is transferred from an image bearing member. well known in the art. The present invention can be equally applied to a transfer unit having a recording material carrying belt as a carrier, and can obtain the same effect as the above-described embodiments. In other words, the conveying member may carry and convey the toner image transferred from the image carrier, or carry and convey the recording material onto which the toner image is transferred from the image carrier. .

Reference Signs List 1 photosensitive drum 4 developing device 4a developing roller 7 intermediate transfer belt 10 process cartridge 12 toner cartridge 17 transfer unit 25 front side plate 26 front rail 27 rear side plate 28 rear rail 32 handle portion 35 wall portion (shielding portion)

Claims (16)

In an image forming apparatus that forms an image using toner,
an image carrier;
a developing device that includes a developing member that supplies toner to the image carrier and forms a toner image by attaching toner to an electrostatic image formed on the image carrier;
The image forming apparatus, comprising: a rotatably movable conveying body that carries and conveys a toner image transferred from the image carrier or carries and conveys a recording material onto which the toner image is transferred from the image carrier; a transfer unit detachable from the apparatus main body of
an inner portion facing an end portion of the transfer unit in a width direction substantially perpendicular to the movement direction of the surface of the conveying body;
has
The transfer unit is arranged above the image bearing member in the direction of gravity, and has a handle at an end in the width direction,
The inner portion is positioned above the image bearing member and below the lowest portion of the handle portion with respect to the direction of gravity, and protrudes toward the end portion of the transfer unit along the width direction. A wall is provided,
The wall portion overlaps the handle portion in the width direction and is formed so as not to reach a position of an end portion facing the inner portion of the carrier, and is substantially parallel to the width direction. The image forming apparatus is formed so as to cover a range of 50% or more of the width of the handle portion in a direction substantially orthogonal to the direction of gravity when the grip portion is closed. The wall portion is formed so as to cover a range of 80% or more of the width of the handle portion in a direction substantially orthogonal to a direction of gravity when viewed substantially parallel to the width direction. Item 1. The image forming apparatus according to item 1. 2. The wall portion is formed so as to cover a range equal to or larger than the width of the developing member in a direction substantially perpendicular to a direction of gravity when viewed substantially parallel to the width direction. 2. The image forming apparatus according to 2 above. A plurality of the image carriers and a plurality of the developing devices provided corresponding to each of the plurality of image carriers are arranged along a direction intersecting the direction of gravity when viewed substantially parallel to the width direction. have
The wall portion has a range that is equal to or greater than the width of the developing member provided in at least one of the plurality of developing devices in a direction that is substantially perpendicular to the direction of gravity when viewed substantially parallel to the width direction. 4. The image forming apparatus according to claim 3, wherein the image forming apparatus is formed so as to cover. The at least one developing device includes a single or a plurality of developing devices including at least the developing device closest to the grip portion in a direction substantially orthogonal to the direction of gravity when viewed substantially parallel to the width direction, among the plurality of developing devices. 5. The image forming apparatus according to claim 4, wherein said wall portion is composed of one continuous portion or a plurality of continuous portions. a replenishment container disposed above the transfer unit with respect to the direction of gravity and containing toner to be replenished to the developing device and detachable from the main body of the device;
1. The wall portion is formed so as to cover a range equal to or larger than the width of the replenishment container with respect to a direction substantially perpendicular to the direction of gravity when viewed substantially parallel to the width direction. 6. The image forming apparatus according to any one of 5. having a plurality of replenishment containers along a direction intersecting with the direction of gravity when viewed substantially parallel to the width direction;
The wall portion is formed to cover a range equal to or greater than the width of at least one of the plurality of replenishment containers in a direction substantially perpendicular to the direction of gravity when viewed substantially parallel to the width direction. 7. The image forming apparatus according to claim 6, wherein: The at least one replenishment container includes at least the replenishment container closest to the handle portion in a direction substantially perpendicular to the direction of gravity when viewed substantially parallel to the width direction of the plurality of replenishment containers. 8. The image forming apparatus according to claim 7, which is a replenishment container. 9. The wall portion is formed so as to fit within a space between both ends of the conveying body with respect to a direction substantially orthogonal to a direction of gravity when viewed substantially parallel to the width direction. The image forming apparatus according to any one of . In an image forming apparatus that forms an image using toner,
an image carrier;
a developing device that includes a developing member that supplies toner to the image carrier and forms a toner image by attaching toner to an electrostatic image formed on the image carrier;
The image forming apparatus, comprising: a rotatably movable conveying body that carries and conveys a toner image transferred from the image carrier or carries and conveys a recording material onto which the toner image is transferred from the image carrier; a transfer unit detachable from the apparatus main body of
an inner portion facing an end portion of the transfer unit in a width direction substantially perpendicular to the movement direction of the surface of the conveying body;
has
The transfer unit is arranged above the image bearing member in the direction of gravity, and has a handle at an end in the width direction,
The inner portion is positioned above the image bearing member and below the lowest portion of the handle portion with respect to the direction of gravity, and protrudes toward the end portion of the transfer unit along the width direction. A wall is provided,
The wall portion overlaps the handle portion in the width direction and is formed so as not to reach a position of an end portion facing the inner portion of the carrier, and is substantially parallel to the width direction. An image forming apparatus, wherein the image forming apparatus is formed so as to cover a range equal to or larger than the width of the developing member with respect to a direction substantially perpendicular to a direction of gravity when the image forming apparatus is closed. A plurality of the image carriers and a plurality of the developing devices provided corresponding to each of the plurality of image carriers are arranged along a direction intersecting the direction of gravity when viewed substantially parallel to the width direction. have
The wall portion has a range that is equal to or greater than the width of the developing member provided in at least one of the plurality of developing devices in a direction that is substantially perpendicular to the direction of gravity when viewed substantially parallel to the width direction. 11. The image forming apparatus according to claim 10, wherein the image forming apparatus is formed so as to cover. The at least one developing device includes a single or a plurality of developing devices including at least the developing device closest to the grip portion in a direction substantially orthogonal to the direction of gravity when viewed substantially parallel to the width direction, among the plurality of developing devices. 12. The image forming apparatus according to claim 11, which is a developing device, and wherein the wall portion is composed of one continuous portion or a plurality of continuous portions. 13. The apparatus according to any one of claims 1 to 12, wherein the distance between the bottom of said handle and the top of said wall in the direction of gravity is greater than 0 mm and equal to or less than 10 mm. Image forming device. 14. The apparatus according to any one of claims 1 to 13, wherein the inner portion is provided with a support portion for supporting the transfer unit, and the wall portion is constituted by a part of a member constituting the support portion. The image forming apparatus according to any one of the items. 14. The image forming apparatus according to any one of claims 1 to 13, wherein the wall portion is configured by part of a frame of the apparatus main body that configures the inner portion. The apparatus main body has an airflow generating means for generating an airflow, and the airflow generating means moves the image from the image carrier side with respect to the transfer unit when viewed substantially parallel to the width direction. 16. The image forming apparatus according to any one of claims 1 to 15, wherein an air current is generated in a direction opposite to the carrier.

Images