JP4899621B2 - Image forming apparatus and transfer unit - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine of these.

  2. Description of the Related Art Conventionally, an image forming apparatus that includes a photosensitive drum on which a toner image is formed and a transfer unit that is disposed at a position facing the photosensitive drum is known. The transfer unit is generally provided with a transfer roller that is disposed at a position facing the photosensitive drum and transfers a toner image on the photosensitive drum (for example, Patent Document 1). reference).

  On the other hand, such an image forming apparatus is generally configured by assembling a large number of members by various methods. As an example of such an assembling method, an elastically deformable portion that can be elastically deformed is provided on at least one of the members to be assembled with each other, and the other member gets over the elastically deformable portion, so-called snap fit in which both members are engaged. There is a technique. By adopting this method, various members can be easily attached. This snap-fit method can be used in various places, for example, when the transfer roller is assembled to the transfer unit.

JP 2005-172992 A

Incidentally, in recent years, there has been an increasing demand for downsizing image forming apparatuses, and in order to realize this downsizing, it is necessary to reduce the size of each member. However, as the size of each member is reduced, the portion that supports each member is also reduced in size. For example, the strength may be reduced, and the member may drop off.
For example, when the transfer roller is assembled to the transfer unit using the snap fit as described above, the height of the elastically deforming portion naturally decreases as the size of each portion is reduced. As a result, the transfer roller easily gets over the elastically deformed portion due to shaking or the like during conveyance of the apparatus, so that the transfer roller may drop out, and the transfer roller may be arranged at a position different from the predetermined position. If the transfer roller is arranged at a position other than the predetermined position as described above, there is a risk of image quality deterioration such as transfer failure. Further, the dropout or the like may cause interference with other members, and the transfer roller itself or other peripheral members may be damaged.

  The present invention has been made in order to solve the technical problems as described above, and an object of the present invention is to stably transfer the transfer roller to a predetermined position even in the case where shaking due to conveyance acts. An object is to provide an image forming apparatus and the like that can be arranged.

  For this purpose, an image forming apparatus to which the present invention is applied is an image forming apparatus for forming an image on a recording material, and holds a transfer roller and a transfer roller for transferring a toner image. A transfer unit including a main body, and a restricting member that restricts movement of the transfer roller so as to maintain a holding state of the transfer roller by the main body, and the restricting member is moved by the main body of the image forming apparatus. It can be characterized by being regulated.

  Here, the image forming apparatus may further include a positioning unit that relatively positions the regulating member and the main body of the image forming apparatus. In addition, a plurality of holding units may be provided in which the main body of the transfer unit holds the transfer roller, and movement of the transfer roller is regulated by a single regulating member in the plurality of holding units. Further, the transfer unit is disposed at a predetermined position in the main body of the image forming apparatus, and a blocking unit that prevents the transfer unit from being disposed at the predetermined position when a component member that performs part of image formation is mounted on the image forming apparatus. It may be characterized by further comprising.

  In addition, the holding portion in which the main body portion holds the transfer roller includes a bearing member that rotatably supports the transfer roller, a housing portion that houses the bearing member, and a bearing member that is formed to be inclined toward the housing portion. And an abutting surface that abuts. Further, the regulating member includes a first regulating member provided on one end side of the transfer roller and a second regulating member provided on the other end side of the transfer roller, and the first regulating member A connecting member for connecting the second restricting member to each other may be further provided.

  From another viewpoint, the image forming apparatus to which the present invention is applied is an image forming apparatus for forming an image on a recording material, and holds a transfer roller and a transfer roller for transferring a toner image. And a restricting member that restricts movement of the transfer roller so that the transfer roller does not fall off from the main body. The restricting member is restricted from moving by the main body of the image forming apparatus. It can be characterized by that.

  Here, the image forming apparatus may further include an engaging portion that engages the main body of the transfer unit in a state where the regulating member can be removed from the main body of the transfer unit. In addition, a plurality of transfer rollers are provided, and movement of at least a part of the plurality of transfer rollers is restricted by a single restricting member provided along the arrangement direction of the transfer rollers. It can be characterized in that it is provided at both ends of a single regulating member in the arrangement direction of the rollers. Furthermore, a belt-like member provided so as to be movable on the outside of the plurality of transfer rollers, and a tension roller for stretching the belt-like member are further provided, and the plurality of transfer rollers include a first transfer roller and And a second transfer roller disposed at a position farther from the stretching roller than the first transfer roller, and the engaging portion is provided on the second transfer roller side. it can.

  Further, when the present invention is regarded as a transfer unit, the transfer unit to which the present invention is applied is provided so as to be movable outside the transfer roller for transferring the toner image, the main body holding the transfer roller, and the transfer roller. A transfer unit main body provided with a belt-shaped member, a restricting member for restricting movement of the transfer roller so as to maintain a holding state of the transfer roller by the main body, and restricting movement of the restricting member, And a protective member for protection.

  According to the present invention, it is possible to provide an image forming apparatus and the like in which the transfer roller can be stably disposed at a predetermined position.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to the present embodiment.
An image forming apparatus 10 shown in FIG. 1 has four color process cartridges (image forming units, drum cartridges) 11a, 11b, 11c, and 11d as constituent members that take part in image formation in a main body 10a in a vertical direction. It is a so-called tandem type arranged in order. Further, a conveyance path 12 through which the paper P is conveyed from a substantially vertical lower side to an upper side is arranged at a corresponding position in each of the process cartridges 11a to 11d. Further, a paper feed cassette 13 for storing the paper P that is transported through the transport path 12 and to which the toner images are sequentially transferred is disposed further below (upstream) of the lowermost (uppermost) process cartridge 11a. Has been. In addition, due to the size of the paper P stored in the paper feed cassette 13, a part of the paper feed cassette 13 protrudes to the back side (rear side, in side) of the main body 10a. If it is a small size, it does not protrude from the main body 10a.

The process cartridges 11 a to 11 d form toner images for yellow (Y), magenta (M), cyan (C), and black (K) in order from the upstream side of the conveyance path 12. Each of the process cartridges 11a to 11d is a cartridge in which a photosensitive drum (image carrier) 14 and various electrophotographic devices sequentially arranged around the photosensitive drum 14 are integrally formed into a cartridge. It is.
The device includes a charging roller that precharges the photosensitive drum 14, a developing device that develops the electrostatic latent image formed on the photosensitive drum 14 charged by the charging roller with each corresponding toner, and And a cleaning device that removes waste toner on the photosensitive drum 14.
Each of the process cartridges 11a to 11d includes a handle 27 that is gripped by the user when being attached or detached at a position where the process cartridge 11a to 11d does not interfere with the transfer unit 30.

An exposure device (ROS) 15 common to the process cartridges 11a to 11d is disposed on the opposite side of the transport path 12 of the process cartridges 11a to 11d. The exposure device 15 drives and drives four semiconductor lasers (not shown) based on image data corresponding to each color. The light from the four semiconductor lasers is deflected and scanned by a polygon mirror (not shown) and guided to an exposure point on the photosensitive drum 14 through an fθ lens (not shown) and a plurality of reflection mirrors, thereby the photosensitive drum 14. It is configured to draw a light image on top.
At locations corresponding to the photosensitive drums 14 of the process cartridges 11a to 11d,
A transfer unit 30 is provided. The transfer unit 30 is provided with a conveyance belt 16 that circulates along the conveyance path 12 and holds a transfer roller 19.
The transport belt 16 is made of a belt material that can electrostatically attract the paper P, and is stretched around a pair of driving roller 17A and driven roller 17B. Further, an adsorption roller 18 for electrostatically adsorbing the paper P to the conveyance belt 16 is disposed in the conveyance path 12.

The transfer roller 19 is disposed on the back side of the transport belt 16 corresponding to the photosensitive drum 14 of each of the process cartridges 11a to 11d. The transfer roller 19 is for transferring the toner image formed on the photosensitive drum 14 onto the paper P by bringing the photosensitive drum 14 and the paper P on the transport belt 16 into close contact with each other.
A fixing device 20 is provided in the conveyance path 12 further above (downstream side) of the uppermost (most downstream) process cartridge 11d. On the upper part of the main body 10a, a paper discharge unit 21 is provided integrally with the main body 10a for storing the paper P discharged after the toner image is fixed by the fixing device 20. The main body 10 a is provided with a reversing conveyance path 22 for reversing the paper P, one side of which has been fixed by the fixing device 20, and sending it again to the conveyance path 12.

FIG. 2 is a diagram for explaining the manual feed tray 23.
As shown in FIG. 2, the main body 10a of the image forming apparatus 10 is provided with a manual feed tray 23 that is rotatable about a rotation fulcrum J provided at the lower end. That is, the manual feed tray 23 is configured to be openable and closable on the front side (front side and out side). When the manual feed tray 23 is rotated in the opening direction, a desired paper P can be set in an insertion window (not shown). As described above, the image forming apparatus 10 is configured to feed paper P other than the paper P stored in the paper feed cassette 13 from the manual feed tray 23.
Here, in a state where the paper P on which the toner image is to be transferred is set, either one of the paper P in the paper feed cassette 13 and the paper P in the manual feed tray 23 is instructed by a user to a control device (not shown). Are sent at a predetermined timing. The sent paper P is transported to the transport path 12 via a plurality of transport rollers 24 and sent to the transfer positions of the process cartridges 11 a to 11 d via the transport belt 16.

FIG. 3 is a view for explaining the cover member 25.
As shown in FIG. 3, the main body 10a of the image forming apparatus 10 is provided with a cover member 25 as an example of an opening / closing part that can be opened and closed with respect to the main body 10a. The cover member 25 is disposed so as to be rotatable (swingable) about a rotation fulcrum J (supporting portion) provided at the lower end. The cover member 25 functions as an external cover together with the main body 10a in the closed state. That is, the cover member 25 constitutes a side wall portion on the upper side of the paper feed cassette 13 and on the front side of the image forming apparatus 10.
The cover member 25 is provided with a transfer belt 16, a driving roller 17 </ b> A, a driven roller 17 </ b> B, a suction roller 18, a transfer roller 19, and a reverse transfer path 22. Therefore, when the cover member 25 is opened, these components are accompanied and separated from the main body 10a side. Therefore, by opening the cover member 25, the process cartridges 11a to 11d are exposed, and the user can easily access the transport path 12.

Here, each of the process cartridges 11a to 11d is detachably attached to the main body 10a in a substantially horizontal direction. Therefore, the process cartridges 11a to 11d can be attached and detached by opening the cover member 25 of the main body 10a. A set detection sensor (not shown) detects the set state of each of the process cartridges 11a to 11d and outputs the detection result to a control device (not shown).
Further, the handle 27 of each of the process cartridges 11a to 11d is arranged in a region where a regulating member 50 (see FIG. 16) described later is located when the cover member 25 is closed. Further, the process cartridges 11a to 11d are arranged side by side in a direction away from the rotation fulcrum J.
Thus, by opening the cover member 25, the process cartridges 11a to 11d can be exposed and replaced. Further, it is possible to deal with a paper jam (jam clear) with the photosensitive drum 14 exposed. Thus, the maintainability of the image forming apparatus 10 is improved.

FIG. 4 is a view for explaining a pulled-out state of the paper feed cassette 13.
The paper feed cassette 13 is accommodated in a cassette accommodating portion 26 provided in the main body 10a, and is configured to be drawable from the front side of the main body 10a. More specifically, the paper feed cassette 13 can be pulled out and inserted into the cassette housing portion 26 with the manual feed tray 23 and the cover member 25 closed.
The paper feed cassette 13 is provided with an insertion window in which the paper P for the manual feed tray 23 is set. Further, the paper feed cassette 13 is provided with a part of a plurality of transport rollers 24 for transporting the paper P on the manual feed tray 23. Thus, the paper feed cassette 13 is formed with a delivery path through which the paper P set in the insertion window is delivered to the transport path 12.

Next, the internal configuration of the image forming apparatus will be described.
FIG. 5 is a perspective view showing a state in which the cover member 25 is opened. This figure shows a state where the process cartridges 11a to 11d (see FIG. 1) are not mounted.
When the cover member 25 is opened around the rotation fulcrum J, the transfer unit 30 is separated from the main body 10a. As a result, a large opening 10 c is formed in the image forming apparatus 10. Then, when the cover member 25 is closed from the state of this figure, the transfer unit 30 is disposed at a predetermined position of the main body 10a.
Here, the inside of the main body 10a will be described. The process cartridges 11a to 11d (shown in FIG. 5) are provided on both side inner walls (one not shown) of the main body 10a so as to protrude from the side inner walls toward the inner side of the main body 10a. 1d) is provided at both ends. Furthermore, a plurality of stopper portions 10e that protrude from the side wall to the inside of the main body 10a are provided on both inner walls (one not shown) of the main body 10a. The stopper portion 10e abuts against the restriction member 50 (described later) when a later-described restriction member 50 (see FIG. 10) is attached to the transfer unit 30.

FIG. 6 is a diagram for explaining the transfer unit 30.
The transfer unit 30 shown in the figure includes a plurality of transfer rollers 19, a main body 31 that holds the transfer rollers 19, a transport belt 16, and an adsorption roller 18. Further, the transfer unit 30 includes a bearing member 40 (see FIG. 7) described later between the transfer roller 19 and the main body 31. The bearing member 40 allows each transfer roller 19 to rotate with respect to the main body 31.

Next, the A part shown in FIG. 6 will be described in detail.
FIG. 7 is an explanatory view showing the holding portion 35 of the transfer roller 19 in the main body portion 31 of the transfer unit 30. In addition, illustration of the conveyance belt 16 is abbreviate | omitted in this figure.
As shown in the figure, the main body portion 31 has an outer wall portion 32 at both end portions thereof, an inner wall portion 33 formed inside the outer wall portion 32 with a predetermined gap from the outer wall portion 32, and An accommodating portion 34 is provided between the outer wall portion 32 and the inner wall portion 33 and accommodates a part of a regulating member 50 (see FIG. 10) described later. On the other hand, a bearing member 40 disposed between the transfer roller 19 and the main body 31 is provided. The bearing member 40 is held by a holding portion 35 provided in the main body portion 31. As a result of the bearing member 40 being held by the holding portion 35, the transfer roller 19 is configured to be rotatable with respect to the main body portion 31.

Next, the holding unit 35 will be described.
FIG. 8 is an explanatory diagram showing the vicinity of the holding unit 35 in an enlarged manner. In the drawing, the illustration of the transfer roller 19 is omitted.
As shown in the figure, the holding portion 35 provided in the main body portion 31 is provided with a storage portion 39 for storing the bearing member 40. The holding portion 35 includes two protruding pieces 35 a that are formed to protrude from the bottom portion 37 of the main body portion 31 toward the conveyance belt 16 (see FIG. 6) and are disposed to face each other. The holding portion 35 includes a regulation projection 35d that is located at the tip of each projection piece 35a and is arranged to project toward the other projection piece 35a.
Further, the holding portion 35 is formed at two locations on the inner wall portion 33 and is formed so as to protrude toward the inside of the main body portion 31 and is arranged substantially parallel to the axial direction of the transfer roller 19 (see FIG. 7). A partition wall 36 is provided so as to face each other across the transfer roller 19. The holding portion 35 is provided at each partition wall 36 and protrudes toward the other partition wall 36 and is disposed substantially parallel to the inner wall portion 33, and is provided at the tip of each projection wall 35b. And a convex portion 35 h protruding toward the inner wall portion 33.

On the other hand, the bearing member 40 includes a base portion 45 that rotatably supports the transfer roller 19, a concave portion 43 that is formed on a surface facing the inner wall portion 33 and that forms a gap 70 between the inner wall portion 33, and a base portion 45. There are provided restricting protrusions 41 that are provided on both side surfaces of the member and restrict the movement of the base portion 45 by abutting against the restricting protrusions 35d. The bearing member 40 is disposed substantially parallel to the inner wall portion 33 and has a protruding piece 42 sandwiched between a protruding portion 35h formed on the protruding wall 35b and a protruding portion 33a formed on the inner wall portion 33, and a base And a top portion 44 formed on the surface of the portion 45 on the side of the conveyor belt 16 (see FIG. 6).
Furthermore, the transfer unit 30 in the present embodiment includes a compression spring 71 (see FIG. 9) as an elastic member that presses the bearing member 40 toward the transport belt 16 (see FIG. 6), a bottom 37 of the main body 31, and A bearing member 40 is further provided.
In the present embodiment, the restricting protrusion 35d of the protruding piece 35a and the restricting protrusion 41 of the bearing member 40 abut against each other, and the movement of the transfer roller 19 in the direction of the conveying belt 16 (see FIG. 6) is restricted. be able to.

Further, the bearing member 40 will be described in detail.
FIG. 9 is an explanatory view showing a cross section in the vicinity of the bearing member 40.
As shown in the figure, in the present embodiment, a storage portion 39 for storing the bearing member 40 is provided. And the bearing member 40 accommodated in this accommodating part 39 is provided with the receiving hole 46 for supporting the transfer roller 19 (refer FIG. 7) rotatably in the approximate center part of the base part 45. As shown in FIG.
Further, a compression spring 71 is provided between the bearing member 40 and the bottom portion 37 of the main body 31 to press the bearing member 40 toward the transport belt 16 (see FIG. 6) as described above.
Further, the regulation protrusion 41 provided on the side surface of the bearing member 40 has a regulation surface 41a on the side where the regulation protrusion 35d is located. The restricting surface 41 a is configured such that the wedge angle α of the wedge-shaped region formed between the side surface of the base portion 45 is an acute angle. More specifically, the regulation surface 41 a is formed so as to be separated from the bottom portion 37 as it is separated from the base portion 45.

On the other hand, the restricting projection 35d provided at the tip of the protruding piece 35a is formed on the bottom 37 side so as to be inclined toward the accommodating portion 39 and has a restricting surface 35k as an abutting surface that abuts against the restricting projection 41 of the bearing member 40. Have. More specifically, the regulation surface 35k is formed so as to approach the bottom portion 37 as the distance from the protruding piece 35a increases.
In the state shown in this figure, when the bearing member 40 tries to move away from the bottom portion 37, the restriction protrusion 41 of the bearing member 40 abuts against the restriction protrusion 35d of the protruding piece 35a as described above. In the present embodiment, since the restricting surface 41a and the restricting surface 35k formed on the restricting protrusion 41 and the restricting protrusion 35d are arranged at the angles as described above, the movement of the bearing member 40 can be effectively restricted. It is possible.

  By the way, in recent years, downsizing of apparatuses has been increasingly desired. For this reason, the apparatus according to this embodiment also attempts to satisfy this requirement by reducing the thickness, gaps, and the like of various members. In the present embodiment, for example, the dimensions of the bearing member 40 and the holding portion 35 are small. Moreover, the structure which suppressed the protrusion amount of the control protrusion 41d formed in the front-end | tip of the control protrusion 41 provided in the bearing member 40 and the protrusion piece 35a as much as possible is employ | adopted. However, when the dimensions and the like of each part are reduced in this way, the strength decreases. Further, when the protruding amount of the restricting protrusion 41 and the restricting protrusion 35d is reduced, the amount of catch between the restricting protrusion 41 and the restricting protrusion 35d is reduced. For this reason, there arises a problem that the bearing member 40 and the transfer roller 19 are likely to be detached from the transfer unit 30 (easily fall off) due to shaking, impact, or the like caused by conveyance or dropping of the apparatus. Therefore, in the present embodiment, the transfer roller 19 is prevented from coming off by preventing the bearing member 40 from coming off (dropping off).

FIG. 10 is an explanatory view showing a state in which a regulating member 50 for preventing the transfer roller 19 from coming off is attached.
The transfer unit 30 shown in the figure includes a regulating member 50 that regulates the movement of the transfer roller 19 (see FIG. 6) and maintains the holding state of the transfer roller 19 by the main body 31.
The regulating member 50 is detachably provided along the moving direction of the conveying belt 16 and at both ends of the main body 31 in a direction orthogonal to the moving direction of the conveying belt 16. Two restricting members 50 are provided to restrict the movement of the transfer roller 19 at both ends of the transfer roller 19 (see FIG. 6).

Further, the restriction member 50 will be described in detail.
FIG. 11 is a perspective view showing details of the regulating member 50.
The regulating member 50 shown in the figure is made of resin (specifically, polypropylene (PP)). The restriction member 50 includes a plate-like main body 51 including a contact portion 51a formed in a concave shape into which the stopper portion 10e shown in FIG. In the longitudinal direction of the main body 51, a plurality (four in the present embodiment) of restricting portions (first restricting portion 52 to fourth restricting portion 55) that restrict the movement of the bearing member 40, and An attachment portion 56 is provided at one end portion of the main body portion 51 to which a connecting member 61 described later is attached.
The first to fourth regulating portions 52 to 55 serve to regulate the movement of the four transfer rollers 19 shown in FIG. In this embodiment, a configuration is adopted in which the movement of the plurality of transfer rollers 19 is regulated by one (single) regulating member 50 as described above. As a result, the number of parts can be reduced and the cost can be reduced. In addition, it is possible to improve workability during mounting and removal.

Next, each regulation part (the 1st regulation part 52-the 4th regulation part 55) is explained in detail.
FIG. 12 is a perspective view showing details of each regulating portion. 12A shows the first restricting portion 52 in FIG. 11, and FIG. 12B shows the second restricting portion 53 in FIG. The fourth restricting portion 55 has the same configuration as the first restricting portion 52, and the third restricting portion 54 has the same configuration as the second restricting portion 53, and therefore the third restricting portion 54 and the fourth restricting portion. Description of 55 is omitted.
First, the first restriction unit 52 will be described. The first restricting portion 52 shown in FIG. 12A is formed on the same surface as the main body portion 51 and extends from the main body portion 51 toward the transfer roller 19 (see FIG. 6) side. A portion 52b is provided. The first restricting portion 52 includes a facing portion 52a provided at the tip of the extending portion 52b and protruding from the extending portion 52b toward the bottom portion 37 (see FIG. 8) of the main body portion 31.

  The first restricting portion 52 includes a bottom portion 52c having a V-shaped surface with a shallow angle at a portion facing one side of the facing portion 52a and facing the bottom portion 37, and a bottom portion further from a substantially central portion of the bottom portion 52c. And an insertion portion 52d projecting toward 37. Further, the first restricting portion 52 includes a protruding piece 52e protruding toward the bottom portion 37 from the joint portion 52h between the main body portion 51 and the extending portion 52b. Further, the first restricting portion 52 is provided with two claw-shaped restricting protrusions 52f (one not shown) located at the tip of the protruding piece 52e and protruding toward the transfer roller 19 (see FIG. 6). Yes. And the engaging part of the control member 50 and the main-body part 31 is formed by this control protrusion 52f and the inner wall part 33 (refer FIG. 7) of the main-body part 31. FIG. The first restricting portion 52 includes a box-shaped box-shaped portion 52 g that protrudes from the main body portion 51 toward the bottom portion 37. One side surface of the box-shaped portion 52g constitutes a part of the protruding piece 52e.

Next, the 2nd control part 53 is demonstrated. Basically, it is the same as the first restricting portion 52, but the second restricting portion 53 has a configuration in which portions corresponding to the protruding piece 52e and the restricting protrusion 52f in the first restricting portion 52 do not exist. ing.
That is, the second restricting portion 53 includes an extending portion 53b, a facing portion 53a, a bottom portion 53c, an insertion portion 53d, and a box-shaped portion 53g.
In the present embodiment, as described above, the first restricting portion 52 and the fourth restricting portion 55, that is, the protruding pieces on the restricting portions located on the (both) end portions of the restricting member 50 among the plurality of restricting portions. 52e and restricting protrusions 52f are provided. As a result, the restriction load in the first restriction part 52 and the fourth restriction part 55 is increased. The vicinity of the end portion has a high possibility of interference with other members and tends to come off easily. In the present embodiment, as described above, the restriction load of the restriction portion located in the vicinity of the end portion of the restriction member 50 is made larger than that of the other restriction portions, thereby suppressing the unintentional release of the restriction member 50 from the main body portion 31. is doing.

Although not shown, for example, the first restricting portion 52 and the fourth restricting portion 55 are not provided with the protruding pieces 52e and the restricting protrusions 52f, and the second restricting portion 53 and the third restricting portion 54 are provided. The protrusion piece 52e and the restricting protrusion 52f can be provided on.
This point will be described with reference to FIG. As shown in FIG. 10, the conveyor belt 16 stretched in a flat shape has a driving roller 17A and a driven roller 17B that also function as a stretching roller at both ends in the moving direction. Tends to be difficult to deform. For this reason, the transfer rollers 19 (the uppermost transfer roller 19 and the lowermost transfer roller 19 (see FIG. 6)) located in the vicinity of both ends of the conveyance belt 16 are less likely to fall off because the movement is restricted by the conveyance belt 16. .

On the other hand, the middle of the transport belt 16 in the moving direction tends to be deformed because it is away from the driving roller 17A and the driven roller 17B. For this reason, the transfer roller 19 (second transfer roller 19 from the upper side in FIG. 6) located in the middle of the conveyance belt 16 is less likely to be regulated from the conveyance belt 16 and is likely to drop off. It is in.
Therefore, as described above, on the second restricting portion 53 and the third restricting portion 54, that is, on the side of the transfer roller 19 disposed at a position away from the driving roller 17A and the driven roller 17B functioning as a stretching roller. By providing the protruding piece 52e and the restricting protrusion 52f, it is possible to suppress the transfer roller 19 from falling off, which is difficult to restrict from the conveying belt 16.

Next, a state where the regulating member 50 is mounted on the main body 31 will be described.
FIG. 13 is an explanatory diagram showing in detail the vicinity of the first restricting portion 52 in a state where the restricting member 50 is attached to the main body portion 31.
As shown in the figure, the main body 51 of the restricting member 50 is located in the accommodating portion 34 formed between the outer wall 32 and the inner wall 33 of the main body 31. And the extension part 52b extended and provided from the main-body part 51 is arrange | positioned so that the inner wall part 33 may be straddled, and the opposing part 52a located in the front-end | tip of the extension part 52b is the bearing member 40 (FIG. 7) is arranged in the vicinity.
In the state of being arranged as shown in this figure, even if a load is applied to the regulating member 50, the regulating projections 52f (see FIG. 12) provided on the first regulating portion 52 and the fourth regulating portion 55 are the inner wall portion 33. Therefore, even if a load is applied to the regulating member 50 from the transfer roller 19 side due to shaking during conveyance, the regulating member 50 is not easily detached from the main body 31.

Further, with reference to FIG. 5 as well, the restricting member 50 abuts against the stopper portion 10e formed on the main body 10a when the cover member 25 is closed, and the movement is restricted by the stopper portion 10e. It has become. More specifically, when the cover member 25 is closed, the regulating member 50 is configured to be sandwiched between the stopper portion 10 e and the main body portion 31. As a result, it is possible to more reliably suppress the transfer roller 19 from dropping due to shaking during conveyance.
In this embodiment, an example of the image forming apparatus has been described. For example, a protective member that prevents damage to the transfer unit 30 is provided for the transfer unit 30 alone, and the protective member and the transfer unit are provided. The movement of the restriction member 50 can also be restricted by sandwiching the restriction member 50 with 30.

  Moreover, in this embodiment, the positioning part which performs the relative positioning of the control member 50 and the main body 10a is further provided. In this embodiment, this positioning part is comprised from the contact part 51a (refer FIG. 11) formed in the control member 50, and the stopper part 10e (refer FIG. 5) formed in the main body 10a. In a state where the restriction member 50 is sandwiched between the main body 10a and the transfer unit 30, the stopper portion 10e formed on the main body 10a is fitted into the contact portion 51a formed on the restriction member 50, and the restriction member 50 and the main body 10a are engaged. Positioning is done. As a result, it is possible to suppress the displacement of the regulating member 50 with respect to the main body 10a in the longitudinal direction of the regulating member 50, and it is possible to hold the bearing member 40 and the transfer roller 19 more stably.

Furthermore, this 1st control part 52 is demonstrated.
FIG. 14 is an explanatory diagram in which the illustration of the conveyance belt 16 is omitted from the state of FIG. In addition, in the drawing, the protruding pieces 35a and the restricting protrusions 35d are not shown.
As shown in the drawing, in a state where the regulating member 50 is mounted on the main body 31, the facing portion 52a is located in a space formed between the inner wall portion 33 and the protruding wall 35b. Further, the bottom portion 52c of the facing portion 52a comes into contact with the top portion 44 of the bearing member 40. Therefore, movement of the bearing member 40 and the transfer roller 19 attached to the bearing member 40 in a direction away from the bottom portion 37 (see FIG. 8) is restricted. For this reason, the transfer roller 19 can be prevented from coming off (dropping off) from the main body 31 due to shaking or dropping that occurs during conveyance.
Further, since the top portion 44 of the bearing member 40 formed so as to rise in a V shape and the bottom portion 52c of the opposing portion 52a formed so as to be recessed in a V shape are engaged with each other, even if shaking or the like acts due to conveyance or the like, the transfer roller 19 can be stably arranged.

Furthermore, since the insertion portion 52d (see FIG. 12) of the regulating member 50 is located in the gap 70 (see FIG. 8), the movement of the transfer roller 19 in the paper transport direction can be regulated, and the transfer roller 19 is more stable. It becomes possible to arrange.
The movement of the restricting member 50 in the axial direction of the transfer roller 19 is restricted by positioning the inner wall portion 33 (see FIG. 7) between the facing portion 52a and the like and the protruding piece 52e (see FIG. 12). Further, the movement of the regulating member 50 in the longitudinal direction is regulated by the bearing member 40 abutting against the projecting wall 35b.
By adopting the above configuration, it is possible to prevent the bearing member 40 and the transfer roller 19 from falling off during conveyance. Therefore, it is possible to actively reduce the size and space saving around the bearing member 40. As a result, it is possible to finally reduce the size of the apparatus.

The restricting member 50 is removed from the transfer unit 30 by the user or the like after the completion of conveyance or the like. In the present embodiment, a configuration for easily removing the regulating member 50 is employed.
FIG. 15 is an explanatory view showing a state around the regulating member 50.
In this embodiment, the display part 60 and the string-shaped connection member 61 which connects this display part 60 and the control member 50 are further provided. In the drawing, the illustration of the transfer unit 30 (see FIG. 10) is omitted.
The display unit 60 plays a role of indicating to the user or the like that when the image forming apparatus is used, it is necessary to remove the regulating member 50, and how to remove the regulating member 50.
The connecting member 61 is between the first connecting member 61 a that connects the display unit 60 and one restricting member 50, and between the one (first) restricting member 50 and the other (second) restricting member 50. It is composed of a second connecting member 61b which is arranged loosely (in a state where no tension is applied) and connects one restricting member 50 and the other restricting member 50. In addition, the connection member 61 is attached to the attachment part 56 (refer FIG. 11) formed in the ring shape.

  When a user or the like pulls the display unit 60, first, tension is applied to the first connecting member 61a, and a large load acts on one of the regulating members 50 side. With this load, first, the first restricting portion 52 (see FIG. 11) of the one restricting member 50 starts to be separated from the main body portion 31 (see FIG. 10). Thereafter, the second restricting portion 53 and the third restricting portion 54 (see FIG. 11) are sequentially separated from the main body portion 31. When the second restricting portion 53 and the third restricting portion 54 are separated from each other, tension gradually starts to be applied to the second connecting member 61b side, and the first restricting portion 52 of the other restricting member 50 is the main body portion. 31. Finally, both regulating members 50 are removed from the main body 31.

  When the configuration of the present embodiment is employed, a load can be applied to one of the restricting members 50 in a concentrated manner. For this reason, it becomes possible to make small the load for removing the control member 50 in the initial stage of removal. In particular, in the present embodiment, as described above, the restriction protrusion 52f is provided on the first restriction portion 52 located at the end portion in the longitudinal direction of the restriction member 50 (see FIG. 12). For this reason, in the 1st control part 52, compared with the 2nd control part 53 and the 3rd control part 54, the load required in order to remove the control member 50 from the main-body part 31 also becomes large. If a configuration in which a load acts on one restricting member 50 in a concentrated manner as in the present embodiment is adopted, even the restricting member 50 having such a configuration can be easily removed from the main body 31. It becomes possible. Further, in the present embodiment, each of the regulating members 50 is not removed separately, but can be removed integrally by the connecting member 61. For this reason, it becomes possible for the user or the like to remove both the restricting members 50 with a single operation, and the removal work of the restricting members 50 can be simplified.

Furthermore, in this embodiment, the regulating member 50 is made of resin as described above. For this reason, when removing the regulating member 50, for example, the protruding piece 52e (see FIG. 12) in the first regulating portion 52 can be deformed, and the engagement between the regulating projection 52f and the inner wall portion 33 is released. Can do.
In the present embodiment, in the state shown in FIG. 1 in which the cover member 25 is closed, the display unit 60 is disposed in a state exposed to the outside of the apparatus in order to notify the user or the like of the presence of the regulating member 50. In the present embodiment, the connecting member 61 is composed of the first connecting member 61 a and the second connecting member 61 b as described above, and the first connecting member 61 a connected to the display unit 60 is only the one regulating member 50. The structure that is connected to When the shape in which the display unit 60 is connected simultaneously with the two regulating members 50 is employed, the length of the connecting member 61 becomes long when the display unit 60 is disposed outside the apparatus. By adopting the configuration in the present embodiment, the length of the connecting member 61 can be shortened even when the display unit 60 is disposed outside the apparatus.

By the way, in this embodiment, the structure for preventing the forgetting removal of the control member 50 is further employ | adopted. Next, a configuration for preventing this forgetting to remove will be described.
FIG. 16 is a schematic configuration diagram illustrating the operation of the cover member 25 with respect to the main body 10a.
In the image forming apparatus according to the present embodiment, after the conveyance is finished, the process cartridges 11a to 11d are mounted on the main body 10a, and then the cover member 25 provided with the transfer unit 30 is closed with respect to the main body 10a as shown in FIG. It is done.
In the present embodiment, when the restriction member 50 remains attached to the transfer unit 30 (not removed), the restriction member 50 and the process cartridge 11a are provided when the cover member 25 is closed. A configuration in which the handle 27 is engaged (abuts) is adopted. As a result, the transfer unit 30 is prevented from being placed at a predetermined position. Further, the movement of the cover member 25 is restricted, and the cover member 25 cannot be closed, and the cover member 25 is kept open.
When the restriction member 50 is not removed, the bearing member 40 (see FIG. 14) remains pressed by the restriction member 50. As a result, the transfer roller 19 attached to the bearing member 40 remains disposed at a position away from the photosensitive drum 14 (see FIG. 1), which may cause a transfer failure or the like.

As described above, by adopting a configuration in which the regulating member 50 and the handle 27 are brought into contact with each other, it is possible to confirm that there is an obstacle (the regulating member 50 in the present embodiment) between the main body 10a and the cover member 25. Can be recognized. As a result, it is possible to prompt the user to remove the restricting member 50, and it is possible to suppress the occurrence of transfer defects and the like.
Furthermore, in this embodiment, the structure which the handle 27 of the process cartridge 11a nearest to the rotation fulcrum J and the regulating member 50 abuts among the plurality of process cartridges (11a to 11d) provided.
As described above, by disposing the abutting portion at a position close to the rotation fulcrum J, when the cover member 25 is closed, the grip 27 and the regulating member 50 are moved at a stage where the moving speed of the cover member 25 is relatively small. A bump will occur. For this reason, it becomes possible to make the impact which arises at the time of abutment of both members comparatively small, and can suppress the failure | damage of each member by an impact, etc. In addition, it is possible to notify the user or the like of the removal of the regulating member 50 at the initial stage when the cover member 25 is closed.

Next, the state in which the handle 27 and the regulating member 50 abut will be described in detail.
FIG. 17 shows a state where the handle 27 of the first process cartridge 11a and the regulating member 50 are in contact with each other.
As shown in FIG. 16 and FIG. 16, the restricting member 50 is configured to abut against the handle 27 of the first process cartridge 11 a closest to the rotation fulcrum J. Further, the handle 27 is configured to abut against a regulating member 50 (see FIG. 10) provided at both ends of the transfer roller 19. For this reason, when the restricting member 50 and the handle 27 abut against each other, the impact is alleviated and it is possible to suppress breakage of each part. Further, it is possible to stabilize the behavior of the cover member 25 and the like at the time of abutment.

Furthermore, a state where the handle 27 and the regulating member 50 are in contact with each other will be described from another angle.
18 is a cross-sectional view showing the vicinity of the handle 27 and the regulating member 50 in FIG.
The handle 27 shown in the figure is provided with a stopper portion 70a as a second surface which is formed in a flat shape and against which the regulating member 50 abuts.
On the other hand, the regulating member 50 is formed on a flat surface, and an abutting portion 51b as a first surface that abuts against the stopper portion 70a at an end portion of the main body portion 51 near the rotation fulcrum J (see FIG. 16). It is equipped with. Furthermore, the regulating member 50 includes a pressing portion 51c that is pressed against the main body portion 31 when a load is applied on the opposite side of the abutting portion 51b with the main body portion 51 interposed therebetween.
In this embodiment, when the handle 27 and the regulating member 50 are abutted, a configuration is adopted in which the stopper portion 70a and the abutting portion 51b are in surface contact with each other. By making the surface contact in this way, the contact area can be ensured, and excessive concentrated load does not act at the time of application, and it is possible to prevent the handle 27 and the regulating member 50 from being damaged. In addition, it is possible to suppress slip and the like at the abutting portion, and stable abutment is possible. Further, when the regulating member 50 comes into contact with the handle 27, the transfer unit 30 and the cover member 25 (see FIG. 16) can be prevented from wobbling and the like so that the transfer unit 30 can be stabilized.

Further, in the present embodiment, the stopper portion 70a is disposed in a direction substantially orthogonal to the mounting direction (see arrow A in FIG. 18) of the process cartridge 11a (see FIG. 16). Further, when the restricting member 50 and the handle 27 abut, the abutting portion 51b of the restricting member 50 is also in a relationship that is substantially orthogonal to the mounting direction of the process cartridge 11a.
On the other hand, when the process cartridge 11a is mounted on the main body 10a, an engaging portion (not shown) with which the process cartridge 11a abuts is formed on the main body 10a in order to perform positioning in the mounting direction.
By disposing the stopper portion 70a and the abutting portion 51b in a relationship substantially orthogonal to the mounting direction of the process cartridge 11a, an engagement portion (not shown) is arranged on the main body 10a to apply a load from the regulating member 50 acting on the handle 27. ) Can be effectively communicated to. That is, it is possible to make the direction of the load applied to the handle 27 acting from the restricting member 50 coincide with the direction of the load supported by the engaging portion (not shown). As a result, wobbling of the process cartridge 11a can be suppressed, and the abutment between the regulating member 50 and the handle 27 can be further stabilized.

Further, in the present embodiment, as described above, the pressing portion 51 c of the regulating member 50 is pressed against the receiving portion 38 of the main body portion 31 when the regulating member 50 and the handle 27 abut against each other. With this configuration, when a load is applied to the regulating member 50 from the handle 27, the swinging of the regulating member 50 can be suppressed, and the regulating member 50 can be stabilized. Further, the wobbling of the transfer unit 30 can be suppressed. In addition, it is possible to suppress breakage of the restricting member 50 due to the handle 27.
In the present embodiment, a suppression unit that suppresses displacement of the regulating member 50 relative to the transfer unit 30 is provided. In the present embodiment, the suppressing portion is composed of an insertion portion 52d (see FIG. 12), a bearing member 40, and a protruding wall 35b (see FIG. 8). The insertion portion 52d is inserted into the gap 70 formed by the recess 43 (see FIG. 8) of the bearing member 40, and when the bearing member 40 abuts against the protruding wall 35b (see FIG. 8), the regulating member 50 is Movement in the longitudinal direction is suppressed. For this reason, the restricting member 50 can be further stably arranged, and the butting of the restricting member 50 and the handle 27 can be stabilized.

1 is a schematic configuration diagram illustrating an image forming apparatus according to an exemplary embodiment. It is a figure for demonstrating a manual feed tray. It is a figure for demonstrating a cover member. FIG. 6 is a diagram for explaining a drawer state of a paper feed cassette. It is the perspective view which showed the state which opened the cover member and the cover member separated from the main body. It is a front view of a transfer unit. It is explanatory drawing which showed the holding | maintenance part of the transfer roller in a main-body part. It is explanatory drawing which expanded and showed about the holding | maintenance part vicinity. It is explanatory drawing which showed the cross section of the bearing member vicinity. It is explanatory drawing which showed the state which attached the control member for preventing the detachment | transfer of a transfer roller. It is the perspective view which showed the detail of the control member. It is the perspective view which showed the detail of each control part. It is explanatory drawing which showed in detail the 1st control part vicinity in the state which attached the control member to the main-body part. It is explanatory drawing which abbreviate | omitted illustration of the conveyance belt from the state of FIG. It is explanatory drawing which showed the state around a control member. It is a schematic block diagram explaining operation | movement with respect to the main body of a cover member. The state where the handle and the regulating member of the first process cartridge are in contact with each other is shown. FIG. 18 is a cross-sectional view showing the vicinity of the handle and the regulating member in FIG. 17.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus, 10a ... Main body, 10e ... Stopper part, 11a, 11b, 11c, 11d ... Process cartridge, 16 ... Conveyor belt, 17A ... Drive roller, 17B ... Driven roller, 19 ... Transfer roller, 30 ... Transfer unit , 31 ... body part, 35 ... holding part, 35k ... regulating surface, 39 ... storage part, 40 ... bearing member, 50 ... regulating member, 51a ... contact part, 52f ... regulating projection, 61 ... connecting member

Claims (13)

An image forming apparatus for forming an image on a recording material,
A transfer unit comprising a transfer roller for transferring a toner image and a main body for holding the transfer roller;
Regulating the movement of the transfer roller so as to maintain the holding state of the transfer roller by the main body, and a regulating member removed before image formation is performed ,
The restriction member includes a recess, and the movement of the restriction member is restricted when a protrusion provided in the image forming apparatus enters the recess . A plurality of holding portions for holding the transfer roller by the main body portion of the transfer unit are provided,
The image forming apparatus according to claim 1, wherein movement of the transfer roller is regulated by the single regulating member in the plurality of holding units. The transfer unit is attached, and further includes an opening / closing part provided to be openable / closable with respect to the main body of the image forming apparatus,
When the opening / closing part is operated by the user and the opening / closing part is closed in a state in which the constituent member responsible for part of the image formation is mounted on the main body of the image forming apparatus, the regulating member hits the constituent member and the user The image forming apparatus according to claim 1, wherein a closing operation of the opening / closing portion is restricted.   The holding portion for holding the transfer roller by the main body is formed with a bearing member for rotatably supporting the transfer roller, a housing portion for housing the bearing member, and an inclination toward the housing portion. The image forming apparatus according to claim 1, further comprising an abutting surface that abuts against the bearing member. The restriction member is composed of a first restriction member provided on one end side of the transfer roller and a second restriction member provided on the other end side of the transfer roller,
The image forming apparatus according to claim 1, further comprising a connecting member that connects the first restricting member and the second restricting member to each other. The restriction member is formed of a resin material and is provided so as to be elastically deformable. The restriction member is provided with a hook portion that is hooked on the main body portion of the transfer unit and restricts movement of the restriction member with respect to the main body portion. The image forming apparatus according to claim 1, wherein: The transfer roller is arranged in a state aligned in Rutotomoni one direction provided with a plurality of,
The restricting member is disposed along the one direction and restricts movement of the plurality of transfer rollers,
The image forming apparatus according to claim 6 , wherein the catch portion provided on the restriction member is provided at both end portions in the longitudinal direction of the restriction member . A belt-like member provided movably on the outside of the plurality of transfer rollers provided; and a tension roller for stretching the belt-like member;
The plurality of transfer rollers include a first transfer roller and a second transfer roller disposed at a position farther from the stretching roller than the first transfer roller,
The restricting member is disposed from the first transfer roller to the second transfer roller to restrict movement of the first transfer roller and the second transfer roller,
The regulating said caught portion provided on member according to claim 6, characterized in that provided in the second transfer roller side of said first transfer roller side and the second transfer roller side Image forming apparatus. The holding portion where the main body portion holds the transfer roller is provided with a bearing member that rotatably supports the transfer roller, and a housing portion that houses the bearing member,
The regulating member regulates the movement of the transfer roller by regulating the movement of the bearing member,
The surface of the bearing member that faces the restriction member is formed so as to be convex toward the restriction member side, and is formed so that the cross section is V-shaped,
The surface of the restriction member that faces the bearing member is formed to be recessed and have a V-shaped cross section.
The bearing member is formed so as to be convex toward the regulating member and has a V-shaped cross section. The bearing member is formed to be concave and has a V-shaped cross section. The image forming apparatus according to claim 1, wherein the surface of the formed regulating member meshes with the regulating member to restrict movement of the bearing member. The holding portion where the main body portion holds the transfer roller is provided with a bearing member that rotatably supports the transfer roller, and a housing portion that houses the bearing member,
The regulating member regulates the movement of the transfer roller by regulating the movement of the bearing member,
The surface of the restriction member that faces the bearing member is provided with a protrusion that protrudes from the surface.
The image forming apparatus according to claim 1, wherein the bearing member has a recess into which the protrusion enters. The image forming apparatus according to claim 1, wherein the restricting member in a state where the protruding portion enters the recess is sandwiched between the main body portion of the transfer unit and the main body of the image forming apparatus. The transfer unit is attached, and further includes an opening / closing portion provided to be openable / closable with respect to the main body of the image forming apparatus,
By closing the opening / closing portion with respect to the main body of the image forming apparatus, the restriction member is pressed against the main body of the image forming apparatus, and the restriction member is connected to the main body portion of the transfer unit and the main body. The image forming apparatus according to claim 11, wherein the image forming apparatus is sandwiched between the main body of the image forming apparatus. A transfer unit main body comprising a transfer roller for transferring a toner image, a main body for holding the transfer roller, and a belt-like member movably provided outside the transfer roller;
A protective member for protecting the transfer unit body;
A regulating member that regulates movement of the transfer roller so as to maintain the holding state of the transfer roller by the main body, and is removed before the toner image is transferred ;
The transfer unit is characterized in that the restricting member includes a recess, and movement of the restricting member is restricted when a protrusion provided on the protection member enters the recess.

Images