JP2002148968A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve failures (blowoff of a cleaning residue such as a toner cloud, change of transfer conditions, lowering of maintenance workability) in accordance with a state that a transfer unit is arranged on a turn support unit. SOLUTION: The transfer unit 3 is constituted by incorporating a transfer member 3a and a cleaning member 3b in on a unit case 3c and the transfer unit 3 together with the unit case 3c is made movable to the turn supporting unit 5. In addition, a nip load of a transfer roll 3a is received by a turn supporting point 5d of the turn supporting unit 5 and a moment is given to the direction to turn the turn supporting unit 5 to the side of an apparatus main body 4 in a setting process of a transfer roll 3a. Furthermore, maintenance parts of an image formation engine 1 are movable arranged while the transfer unit 3 is left located at a setting position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine and a printer, and more particularly, to an image forming apparatus in which a transfer unit is disposed on a rotation support unit which is rotatably supported by an apparatus main body. Regarding improvement.

[0002]

2. Description of the Related Art As an example of a conventional image forming apparatus, for example, an intermediate transfer type image forming apparatus will be described.
A predetermined color component image (a toner image in the case of an electrophotographic method) is formed on a latent image carrier such as a photosensitive drum, and the color component image on the latent image carrier is primarily transferred to an intermediate transfer body such as an intermediate transfer belt. After the transfer, there is already provided one in which a color component image on an intermediate transfer body is transferred (collectively) to a recording material by a transfer unit for secondary transfer. As this type of transfer unit, for example, a transfer unit in which a transfer roll is rotatably supported by a unit case and the unit case is supported by a door unit (openably and closably provided in the apparatus main body) is known. . Further, since there is a concern that untransferred toner or the like may adhere to the transfer roll, a mode in which a cleaning member is provided as a transfer unit for cleaning the transfer roll is already known.

A member such as a door unit of an apparatus main body is often a module having low rigidity and poor positional accuracy from the viewpoint of weight reduction. Normally, a state in which a backup roll (opposite roll) of the intermediate transfer member is in contact with a predetermined nip area is set as an operation position for image formation, and is positioned. Further, in the case where the image forming process of the image forming apparatus has four cycles, or when there is a concern that a long-term contact state may lead to deformation of the transfer roll depending on the material of the transfer roll, a cycle other than the cycle of transferring to the recording material may be used. Alternatively, when the power is turned off, a method is often employed in which the transfer roll is made to stand by at a retract position separated from the set position.

Further, in the above-described transfer roll type image forming apparatus, measures are taken to prevent transfer conditions from deteriorating due to a change in the nip pressure of the transfer roll. For example, a technique for positioning the transfer unit on the intermediate transfer unit with a positioning pin or the like (for example, Japanese Patent Application Laid-Open No. H11-24528 and Japanese Patent Application Laid-Open No. H10-293478), or a repulsive force is generated from the intermediate transfer body when the transfer roll is pressed against To prevent a change in transfer conditions due to a movement of the position of the intermediate transfer member before and after pressing of the transfer roll (for example, Japanese Patent Laid-Open No. 11-265123)
Has already been proposed.

[0005]

However, in a mode in which the transfer unit is provided on a rotation support unit such as a door unit, the following technical problems have been found. In a conventional transfer unit mounting structure, for example, as shown in FIGS. 23A and 23B, a transfer unit 810 is disposed on a door unit 800 having a rotation fulcrum 801, and the transfer unit 810 includes a door. Unit 8
The transfer roll 812 is provided in the opening of the unit case 811 fixed to
A cleaning brush 813 in contact with the transfer roll 812 is provided therein. Further, the transfer roll 812 is supported by a retracting mechanism 820 (for example, a transfer arm 822 that is rocked by an eccentric cam 821, and Swing arm 8
The mechanism 22 is configured to be retractably supported by an urging spring 823 in a predetermined direction. In FIGS. 23A and 23B, reference numeral 830 denotes a belt unit having an intermediate transfer belt 831, and a backup roll 832 serving as a stretching roll is provided on the back surface of the intermediate transfer belt 831 facing the transfer roll 812. ing.

In this type of embodiment, the transfer roll 81
To enable the retracting operation of the transfer roll 81,
2 is swingably supported by the swing arm 822, it is indispensable to secure a large opening area of the unit case 811 in consideration of the swing locus of the transfer roll 812. For this reason, a relatively wide gap is formed between the opening of the unit case 811 and the transfer roll 812. For example, as shown in FIG. 23A, the transfer roll 812 is moved between the set position and the retract position. Under such conditions that the unit case 811 is moved between
There is a concern that the toner cloud 840 will blow out from the gap. Further, as shown in FIG. 23B, the door unit 800 is opened and the work is performed during jam clearance and maintenance, but when the door unit 800 is opened and closed, the unit case 811 of the transfer unit 810 is opened and closed. There is a concern that the toner cloud 840 may blow out from the gap.

In the case where the transfer unit is disposed on a rotation support unit such as a door unit, the transfer roll is pressed against the backup roll of the intermediate transfer belt. A reaction force inevitably acts on the area, and this reaction force acts in a direction to open the door unit, and there is a concern that the door unit may be slightly deformed in the opening direction. Under such circumstances, there is a concern that the positioning accuracy of the transfer unit provided in the door unit may be affected, and the transfer conditions of the transfer roll may change such as a change in the nip pressure of the transfer roll. There is.

Further, in the above-described embodiment, when the intermediate transfer unit is replaced, if the intermediate transfer unit is removed and inserted while the transfer roll is nipped, the intermediate transfer belt moves while sliding on the transfer roll. To become
There is a concern that the intermediate transfer belt may be damaged. For this reason, when the intermediate transfer unit is replaced, a method of opening the door unit and separating the transfer unit from the intermediate transfer unit has been adopted. When replacing the photoconductor unit for image formation, the photoconductor drum and the intermediate transfer belt must be separated to prevent damage to the photoconductor drum. Since the transfer unit could not be immediately inserted and removed, there was a restriction on maintenance work that the photosensitive unit had to be separated from the intermediate transfer unit and replaced. As described above, in the mode in which the transfer unit is disposed on the rotation support unit, there is a point that the maintenance workability is still insufficient.

[0009] Such a technical problem is not limited to the intermediate transfer type image forming apparatus, but similarly occurs in a mode in which the transfer unit is provided on the rotation support unit. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described technical problems, and has a problem (a. Blowing of cleaning residue such as a toner cloud, b. ．Change of transfer condition,
c. It is an object of the present invention to provide an image forming apparatus capable of improving maintenance workability.

[0010]

That is, the first aspect of the present invention is to improve the blowing of cleaning residue such as toner cloud, and as shown in FIG. The image forming engine 1 including the image carrier 2 to be supported is pressed against the surface side of the image carrier 2 via a recording material, and the image carrier 2 is pressed.
And a transfer member 3a for collectively transferring the upper visible image onto a recording material.
A rotation support unit 5 rotatably supported with respect to
A transfer unit 3 in which a transfer member 3a and a cleaning member 3b for cleaning the transfer member 3a are incorporated in a single unit case 3c. The transfer unit 3 is movably held together with the unit case 3c with respect to the moving support unit 5.

According to this aspect, the retracting operation of the transfer member 3a alone is eliminated, and the retracting operation is performed for each unit case 3c, thereby minimizing the opening width of the unit case 3c and cleaning residue from the unit case 3c. Blowing can be prevented.

In such a technical means, the present embodiment is configured such that the transfer member 3a and the cleaning member 3b are provided in the transfer unit 3.
Is assumed. Here, the transfer member 3a may be appropriately selected as long as it is a member capable of contact transfer such as a roll or a belt, and the cleaning member 3b includes various modes such as a brush and a blade. Further, the unit holding mechanism 6 for holding the transfer unit 3 only needs to be movably held together with the unit case 3c, and is not limited to a mode of rotatably supporting. Here, as a typical mode of the unit holding mechanism 6, the unit case 3c is
Is rotated by a lifting member at a position separated from the rotation center of the unit case 3c, and the unit case 3c is swung about the rotation center of the unit case 3c to move the transfer member 3a to the image carrier 2. And those which can be separated from and contacted with. The image forming engine 1 includes various aspects, and the image carrier 2 only needs to carry a visible image, and is not limited in form such as a belt shape and a drum shape. The number may be single or plural.

Further, in such an embodiment, the transfer unit 3 includes a cleaning residue storage section in the unit case 3c, and the unit case 3c is divided into a cleaning member disposition section and a cleaning residue storage section. It is preferable to provide a partition part. In this case, with the mode in which the transfer unit 3 comes and comes together with the unit case 3c, it is possible to avoid a situation in which the cleaning residue adheres to the cleaning member 3b when the transfer unit 3 comes and goes. Further, the partition may be provided integrally with the unit case 3c, or a separate member may be provided.

Further, in the present embodiment, the transfer member 3a of the transfer unit is positioned while being rolled in contact with the positioning member 7 (indicated by a virtual line in the drawing) during the setting process of being placed in contact with the image carrier 2, and the transfer is performed. The cleaning member 3b of the unit 3
It is preferable that the transfer member 3a that is in contact with the positioning member 7 be disposed in a direction in which the rotational load is smaller than the rotational direction of the transfer member 3a. In this case, the load fluctuation of the transfer member 3a when the transfer unit 3 is set is suppressed, and the transfer member 3
The position reproducibility of a can be improved.

In particular, in a mode in which the image carrier 2 is provided with a cleaning member for cleaning, the transfer member 3a of the transfer unit 3 comes into contact with the positioning member 7 in the setting process of contacting the image carrier 2 and rolling. The cleaning member 3b of the transfer unit 3 is positioned in the direction in which the rotational load is smaller than the rotation direction of the transfer member 3a that rolls in contact with the positioning member 7, and the cleaning member 3b of the image carrier 2 (shown in FIG. Is preferably arranged in a direction in which the rotational load is smaller than the rotational direction of the image carrier 1 which rotates in contact with the transfer member 3a which rolls in contact with the positioning member 7. In this case, in a mode in which the cleaning member of the image carrier 2 is provided, the load fluctuation of the transfer member 3a when the transfer unit 3 is set can be suppressed, and the reproducibility of the position of the transfer member 3a due to the load fluctuation can be improved.

A second aspect of the present invention is to improve a change in transfer conditions, and as shown in FIG. 1B, an image forming engine including an image carrier 2 for carrying a visible image. 1
And a transfer member 3a which is pressed against the surface of the image carrier 1 via a recording material and collectively transfers the visible image on the image carrier 2 to the recording material.
In the image forming apparatus provided in the apparatus main body 4, a rotation supporting unit 5 rotatably supported with respect to the apparatus main body 4, the transfer member 3a is incorporated into one unit case 3c, and the transfer member 3a And a transfer unit 3 movably held together with the unit case 3c with respect to the rotation support unit 5 so that the transfer unit 3 can move toward and away from the image carrier 2.
A unit holding mechanism 6 that holds the transfer unit 3 supports the unit case 3c to be rotated by the rotation support unit 5, and sets the unit case 3c at a position separated from the rotation fulcrum 3d of the unit case 3c during the setting process of the transfer unit 3. F, the reaction force R from the rotation fulcrum 3d of the unit case 3c is set in the direction of the rotation fulcrum 5d of the rotation support unit 5, and the rotation of the rotation support unit 5 by the reaction force of the set force F. The moment M about the rotation fulcrum 5d is transferred to the rotation support unit 5
Is set in a direction to be rotated toward the apparatus main body 4 side. Note that the transfer unit 3 of this embodiment includes at least the transfer roll 3 in the unit case 3c.
a, and it is not essential to provide the cleaning member 3b.

According to this aspect, by canceling the moment generated by the nip force of the transfer member 3a with respect to the rotation support unit 5, the deformation of the rotation support unit 6 is suppressed, and the positional accuracy of the transfer member 3a is kept good. be able to.

Still another embodiment of the present invention is shown in FIG.
As shown in (b), the image forming engine 1 including the image carrier 2 for carrying a visible image is pressed against the surface side of the image carrier 2 via a recording material, and In an image forming apparatus including a transfer member 3a for collectively transferring a visual image to a recording material in an apparatus main body 4, a rotation support unit 5 rotatably supported with respect to the apparatus main body 4, and the transfer member 3a. And a transfer unit 3 movably held together with the unit case 3 c with respect to the rotation support unit 6 such that the transfer member 3 a can be moved toward and away from the image carrier 2. A unit holding mechanism 6 for holding the transfer unit 3 supports the unit case 3c on the rotation support unit 6 in a rotating manner, and applies a setting force F to a portion of the unit case 3c remote from the rotation fulcrum 3d in the process of setting the transfer unit 3. What gives , Rotation of the unit case 3c fulcrum 3
d of the rotation support unit 5 due to the reaction force R from d.
The total M ′ of the moment around d ′ (indicated by the phantom line in FIG. 1B) and the moment around the pivot fulcrum 5d ′ of the pivot support unit 5 due to the reaction force of the set force F is pivotally supported. The unit 5 is characterized in that the unit 5 is turned to the side of the apparatus main body 4 or substantially zero.

In this case, the rotation fulcrum 5 of the rotation support unit 5 due to the reaction force from the rotation fulcrum 3d of the unit case 3c.
Since the moment around d 'is opposite to the moment around the rotation fulcrum 5d' of the rotation support unit 5 due to the reaction force of the normal set force F, the moment acting on the rotation support unit 5 can be reduced. Preferred above. For this reason,
Even if the rigidity of the rotation support unit 5 is reduced, deformation of the rotation support unit 6 can be suppressed. In particular, it is preferable to set the total moment of both to substantially zero, since the deformation of the rotation support unit 5 is almost completely prevented.

Further, a third aspect of the present invention is to improve a reduction in maintenance workability, and as shown in FIG. 1C, an image forming apparatus including an image carrier 2 for carrying a visible image. An image forming apparatus comprising an engine 1 and a transfer member 3a, which is in pressure contact with the front side of the image carrier 2 via a recording material and transfers a visible image on the image carrier 2 to the recording material at a time, in the apparatus main body 4. In the apparatus, the rotation supporting unit 5 rotatably supported by the apparatus main body 4 and the transfer member 3a are incorporated in one unit case 3b, and the transfer member 3a can be moved toward and away from the image carrier 2. And a transfer unit 3 that movably holds the unit case 3c with respect to the rotation support unit 5, and the maintenance unit (for example, the image) of the image forming engine 1 in a state where the transfer unit 3a is disposed at the set position. Carrier 2) So as to be one in which is disposed movably maintenance part of the image forming engine 1.
Note that the transfer unit 3 of this embodiment only needs to include at least the transfer roll 3a in the unit case 3c, and it is not essential to include the cleaning member 3b.

According to this aspect, while the transfer unit 3 is set at the set position, the maintenance part of the image forming engine 1, for example, the belt unit as the image carrier 2 is moved in the direction of an arrow indicated by a dashed line, for example. Since the parts can be replaced, the workability of replacing the maintenance parts of the imaging engine 1 can be improved.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings. First Embodiment FIG. 2 is an explanatory view showing a first embodiment of a tandem image forming apparatus to which the present invention is applied. In the figure, a tandem type image forming apparatus includes an image forming unit 22 of four colors (black, yellow, magenta, and cyan in the present embodiment) in a main body housing 21 (specifically, 22a to 22a).
a) a belt unit (belt transport device) including an intermediate transfer belt 230 that is circulated and transported along the direction in which the image forming units 22 are arranged.
23, a recording material supply cassette (not shown) for accommodating a recording material such as paper (not shown) is provided below the main body housing 21. The recording material transport path serving as the recording material transport path is arranged in the vertical direction.

In this embodiment, the image forming units 22 (22a to 22d) are arranged in order from the upstream side in the circulation direction of the intermediate transfer belt 230, for example, for black, yellow, magenta, and cyan (the arrangement is not limited to this. The toner image is formed in any order (not limited to the order), and includes each photoconductor unit 30, each developing unit 33, and one common exposure unit 40. Here, the photoconductor unit 30 includes, for example, a photoconductor drum 31, a charger (a charging roll in this example) 32 for pre-charging the photoconductor drum 31, and a cleaner 34 for removing residual toner on the photoconductor drum 31. Are integrated into a cartridge. The developing unit 33 develops the electrostatic latent image formed by exposure on the charged photosensitive drum 31 by the exposure unit 40 with a corresponding color toner (for example, negative polarity in the present embodiment). is there. On the other hand, the exposure unit 4
Reference numeral 0 denotes, for example, four semiconductor lasers (not shown), one polygon mirror (not shown), an imaging lens (not shown), and mirrors (not shown) corresponding to the respective photoconductor units 30 in the unit case. ) Is stored, the light from the semiconductor laser for each color component is deflected and scanned by a polygon mirror, and a light image is guided to the corresponding exposure point on the photosensitive drum 31 via an imaging lens and a mirror. It is.

In this embodiment, the belt unit 23 has an intermediate transfer belt 230 stretched between a plurality of stretching rolls 231 to 236, and corresponds to the photosensitive drum 31 of each photosensitive unit 30. A primary transfer device (primary transfer roll in this example) 51 is disposed on the back surface of the intermediate transfer belt 230, and a voltage having a polarity opposite to the charging polarity of the toner is applied to the primary transfer device 51, so that the photosensitive drum is charged. The toner image on the transfer belt 31 is electrostatically transferred to the intermediate transfer belt 230 side. Here, the intermediate transfer belt 2
30 is polyimide, polycarbonate, polyester,
A resin such as polypropylene or various rubbers containing an appropriate amount of an antistatic agent such as carbon black is used to form a volume resistivity of 10 ⁶ to 10 ¹⁴ Ω · cm. It is set to about 1 mm. On the other hand, the stretching roll 231 is
Is a steering drive roll that tilts to control meandering in a lateral direction perpendicular to the traveling direction of the intermediate transfer belt 230, and drives the intermediate transfer belt 230.
Reference numerals 2 and 233 denote image forming units 22 (22a to 22a).
d) are surface-applying rolls (both driven rollers) for exposing the primary transfer surface of the intermediate transfer belt 230 to a predetermined position, and a tension roll 234 is used to adjust the bending of the intermediate transfer belt 230. The tension roll 235 is pressed against the intermediate transfer belt 230 with a predetermined tension by a biasing spring (not shown), and a tension roll 235 pushes a recording material into a transfer nip area of a secondary transfer unit 52 described later. It is a recording material posture adjusting roll for regulating the posture, and the stretching roll 236 is a roll (driven roll) which also serves as a backup roll of the secondary transfer unit 52 described later.

Further, a secondary transfer unit 52 is provided at a position corresponding to the stretching roll 236 on the downstream side of the most downstream image forming unit 22d of the intermediate transfer belt 230,
The primary transfer image on the intermediate transfer belt 230 is secondarily transferred (collectively transferred) to a recording material. In the present embodiment, the secondary transfer unit 52 has a secondary transfer roll 522 disposed in the opening of the unit case 521, and this secondary transfer roll is used as a backup roll (in this example, the stretching roll 23).
6 is also used, for example, the secondary transfer roll 522
And the backup roll (stretch roll 23)
In 6), a bias having the same polarity as the charging polarity of the toner is applied. Here, the secondary transfer roll 52
2 is a urethane rubber tube with carbon dispersed on the surface,
The inside is made of foamed urethane rubber with carbon dispersed,
Further, the roll surface is coated with fluorine, the volume resistivity is 10 ³ to 10 ¹⁰ Ω · cm, and the roll diameter is, for example, φ28.
mm, and the hardness is set to, for example, 30 ° (Asuka C). And the backup roll 23
Reference numeral 6 denotes a tube provided with a blend rubber tube of EPDM and NBR in which carbon is dispersed on the surface, and the inside of which is formed of EPDM rubber, and whose surface resistivity is 10 ⁷ to 10.
^The roll is formed to have a roll diameter of, for example, φ28 mm at ¹⁰ Ω / □, and the hardness is set to, for example, 70 ° (Asuka C). In particular, in the present embodiment, the secondary transfer unit 52
Has a cleaning brush 523 for cleaning the surface of the secondary transfer roll 522 in the unit case 521.
The mounting structure and drive system of the secondary transfer unit 52 will be described later.

Further, a belt cleaner 5 is provided upstream of the most upstream image forming unit 22a of the intermediate transfer belt 230.
3 is provided to remove the residual toner on the intermediate transfer belt 230. A feed roll (not shown) for picking up a recording material is provided in a recording material supply cassette (not shown). Immediately after this feed roll, a takeaway roll for sending out the recording material is provided. In the material transport path, transport rolls 6
1 is provided, and a registration roll (registration roll) 62 for supplying a recording material to the secondary transfer portion at a predetermined timing is provided in a recording material conveyance path located immediately before the secondary transfer portion. I have. On the other hand, a fixing device 66 is provided in a recording material conveying path located downstream of the secondary transfer portion, and a discharge roll (not shown) for discharging the recording material is provided downstream of the fixing device 66. The recording material is accommodated in an accommodation tray 68 formed on the upper part of the main body housing 21.

Next, the mounting structure of the secondary transfer unit 52 will be described. In the present embodiment, as shown in FIGS. 2 to 4, a door unit 70 is supported on the side of the main body housing 21 so as to be openable and closable about a pivot point 71. , A secondary transfer unit 52 is attached via a retract mechanism 80. Here, the secondary transfer unit 52 is provided on both sides of the unit case 521 with pivot points (constituted as pins in this embodiment) 52.
4 and a slot 74 in a bracket 73 (indicated by an imaginary line in FIG. 4) attached to a frame 72 of the door unit 70.
(Shown by phantom lines in FIG. 4), and is rotatably supported by locking the rotation fulcrum 524 in the long hole 74.

In this embodiment, the retract mechanism 80 is provided with an eccentric cam 81 which is rotated by a lifting motor (not shown), as shown in FIGS. 4 and 5, and above the eccentric cam 81. Slide the slide lever 82 to the guide roller 83
(See Fig. 6)
A bent portion 82a facing the surface of the eccentric cam 81 is formed at the lower end of the slide lever 2, and the distal end of the bent portion 82a is urged downward by an urging spring 84, while the upper end of the slide lever 82 is pressed. Is formed with a bent portion 82b inclined obliquely downward from the horizontal direction.
A portion of the secondary transfer unit 52 that is separated from the rotation fulcrum 524 of the unit case 521 (the upper part of the unit case 521 in this example) is connected and fixed by a connecting rod 85.

On the other hand, on the belt unit 23 side, as shown in FIGS. 2 to 4, a positioning plate 90 (indicated by a virtual line in the figure) for positioning the secondary transfer roll 522 at the set position is provided. A V-shaped positioning groove 91 for positioning the secondary transfer roll 522 is formed in the positioning plate 90.
The secondary transfer roll 522 is positioned in the positioning groove 91 by moving the guide shaft to the back of the positioning groove 91 (corresponding to the set position) while abutting the support shaft of the two-character transfer roll 522 against one of the edges. It is supposed to be.
Incidentally, in FIGS. 2 to 4, reference numeral 63 denotes a resist roll 6.
The transport chute provided downstream of the door unit 7
0 is opened, one of the transport chutes is opened together with the one registration roll 62 and the door unit 70, and reference numerals 64 and 65 are provided on the downstream side of the secondary transfer portion and directed toward the fixing device 66. The conveyance guide guides and conveys the recording material, and in this example, is opened together with the door unit 70.

FIGS. 6 and 7 show a drive system 100 of the secondary transfer unit 52 used in the present embodiment. In the figure, the drive system 100 of the secondary transfer unit 52 includes:
A drive motor 101 is fixedly arranged on the main body housing 21 (see FIG. 2), and a drive transmission gear 102 is coaxially fixed to a drive shaft of the drive motor 101, while a driven transmission gear is connected to one end of the secondary transfer roll 522. The gear 103 is coaxially fixed, and the drive transmission is performed in any situation where the secondary transfer roll 522 is located at the set position (see FIG. 7A) or the retract position (see FIG. 7B). Gear 102
And the driven transmission gear 103 are meshed with each other. 7A and 7B, the same components as those in FIGS. 2 to 5 are denoted by the same reference numerals, and the detailed description thereof will be omitted.

Next, an image forming process of the image forming apparatus according to the present embodiment will be described. Each image forming unit 2
2 (22a to 22d) form each color component image (toner image) on the photosensitive drum 31 and sequentially primary transfer each color component image on the intermediate transfer belt 230 by the primary transfer device 51.
On the other hand, a recording material is supplied from a recording material supply cassette (not shown), and is conveyed to a secondary transfer portion at a predetermined timing via a registration roll 63. Then, the multi-transferred image primarily transferred onto the intermediate transfer belt 230 is conveyed to a secondary transfer portion, and is collectively transferred to a recording material by the secondary transfer unit 52. Thereafter, the recording material is fixed to the image transferred collectively via the fixing device 66, and then discharged to a discharge tray 68 through a discharge roll (not shown). In each of the image forming units 22, while the residual toner on the photosensitive drum 31 is cleaned by the cleaner 34, the intermediate transfer belt 23
The residual toner on the surface 0 is cleaned by the belt cleaner 53.

In such an image forming process, the secondary transfer unit 52 moves the secondary transfer roll 522 from the retracted position (see FIG. 5B) to the set position (FIG. 5A) immediately before performing the secondary transfer operation. )), And is retracted from the set position to the retract position when the secondary transfer operation is completed or when the power is turned off. Here, the operation state of the retract mechanism 80 when the secondary transfer roll 522 is located at the set position will be described. In the retract mechanism 80, the eccentric cam 81 has the lowest cam surface (FIG. 5).
(See (a)). At this time, the lower bent portion 82 a of the slide lever 82 is not in contact with the cam surface of the eccentric cam 81, and the slide lever 82 is pushed down by the biasing spring 84. Then, the unit case 521
Rotates in the direction of the arrow around the rotation fulcrum 524, and the secondary transfer unit 522 in the unit case 521 approaches the backup roll 236 side, engages with the positioning groove 91 of the positioning plate 90, and performs positioning. Is done.

On the other hand, the operation state of the retract mechanism 80 when the secondary transfer roll 522 is located at the retract position will be described. In the retract mechanism 80, the eccentric cam 81 has the highest cam surface (FIG. 5B). See). At this time, the lower bent portion 82 a of the slide lever 82 is pushed up by the eccentric cam 81, and the slide lever 82 is pushed upward against the urging force of the urging spring 84. Then, the unit case 521 is moved to the pivot 524.
, The secondary transfer unit 522 in the unit case 521 moves in a direction away from the backup roll 236 and reaches a retract position separated from the set position.

In this embodiment, the retract mechanism 80
Has a delay circuit that works when the power is off, and makes it possible to move the secondary transfer roll 522 to the retract position when the power is off. For this reason, in the present embodiment,
When the power is turned off, the retract mechanism 80 operates to always set the secondary transfer roll 522 to the retract position. Therefore, when the power is turned on, the secondary transfer unit 52 starts operating from a state where the secondary transfer roll 522 is held at the retract position.

Further, in this embodiment, the driving system 100 of the secondary transfer unit 52 operates as shown in FIG. 7B, even when the secondary transfer roll 522 is located at the retract position. Since the drive transmission gear 102 and the driven transmission gear 103 that are drivingly connected to 101 are meshed, the secondary transfer roll 522 is immediately driven and rotated.
For this reason, when the secondary transfer roll 522 is moved from the retract position (see FIG. 7B) to the set position (see FIG. 7A), the secondary transfer roll 522 is set to the set position while rotating. can do. Therefore, even if the intermediate transfer belt 230 is rotated in advance before the secondary transfer roll 522 reaches the set position and the image forming process of each image forming unit 22 is started, the secondary transfer roll 5
At the moment when the roller 22 reaches the set position and comes into contact with the intermediate transfer belt 230, the speed of the intermediate transfer belt 230 fluctuates, and there is no adverse effect on the image displacement or the motion quality of the intermediate transfer belt 230.

In the present embodiment, the drive transmission gear 1
The position of 02 is uniquely determined from the positional relationship with the drive motor 101, but the position of the driven transmission gear 103 moves with the change in the position of the secondary transfer roll 522. For this reason, in the present embodiment, when the secondary transfer roll 522 is at the set position (see FIG. 7A), the drive transmission gear 102 and the driven transmission gear 103 mesh with each other at the regular position, and A stable rotation drive is given to the transfer roll 522. However, when the secondary transfer roll 522 is located at the retract position (see FIG. 7B), the meshing state of both gears 102 and 103 is shifted from the normal position, but the tooth radius of the gears 102 and 103 is smaller than the normal position. If the distance between the centers of both gears 102 and 103 is set to be smaller than the sum, the meshing state of both gears 102 and 103 is maintained.

Further, in the present embodiment, when a recording material jam occurs during the transfer operation by the secondary transfer unit 52, as shown in FIGS.
By clearing 0, jam processing can be performed. In this case, the secondary transfer unit 52 is opened together with the door unit 70. The secondary transfer unit 52 is one in which the secondary transfer roll 522 and the cleaning brush 523 are incorporated in the unit case 521, and the retract mechanism 80
As a result, the secondary transfer unit 52 moves along with the unit case, so that the opening of the unit case 521 may be secured by a dimension corresponding to the secondary transfer roll 522, and the unit case 521 and the secondary transfer roll 522 are provided.
There is no unnecessary gap between them. Therefore, even if the secondary transfer unit 52 rotates together with the door unit 70, there is no possibility that the toner cloud is unnecessarily blown out from the opening of the unit case 521.

In the present embodiment, the driving system 100 of the secondary transfer unit 52 includes a secondary transfer roll 522
The driven transmission gear 103 is fixed coaxially with the above, but is not limited to this. For example, FIG.
A drive system 100 as shown in FIG. Drive system 1 of secondary transfer unit 52 in FIG.
Reference numeral 00 designates a drive motor 111 fixedly arranged on the main body housing 21 (see FIG. 2), and a drive transmission gear 112 is coaxially fixed to a drive shaft of the drive motor 111, while a unit case 521 of the secondary transfer unit 52 is provided. Fulcrum 5
24, the driven transmission gear 113 is fixed coaxially.
The driven transmission gear 113 is engaged with the driven transmission gear 114 coaxially fixed to the secondary transfer roll 522, and the secondary transfer roll 522 is set at a set position (see FIG. 8A) or a retract position (see FIG. 8A). 8 (b)), the drive transmission gear 112 and the driven transmission gear 113 are engaged with each other in any situation.

Here, the unit case 521 is rotated about the rotation fulcrum 524 by the retract mechanism 80, and the rotation fulcrum 524 is engaged with the bracket 73 of the door unit 70 while being restrained by the long hole 74. Since the link mechanism is adapted, the position of the rotation fulcrum 524, which is the center of rotation of the link mechanism, does not vary much. For this reason, in this example, the driven transmission gear 113 is fixed to the rotation fulcrum 524 of the unit case 521 with little position fluctuation, and the meshing state with the drive transmission gear 112 at each position can be maintained. It is. In this example, the secondary transfer roll 52 is also used.
When the position 2 is at the set position (see FIG. 8A), the drive transmission gear 112 and the driven transmission gear 113 mesh with each other at a regular position so that the secondary transfer roll 522 is given a stable rotational drive. Has become. However, the secondary transfer roll 5
When the gear 22 is located at the retract position (see FIG. 8B), the meshing state of the two gears 112 and 113 is shifted from the normal position, but the gears 112 and 113 are not more than the sum of the tip radii of the gears 112 and 113. , 113, the meshing state of both gears 112, 113 is maintained.

In this embodiment, the cleaning brush 5 is provided in the unit case 521 of the secondary transfer unit 52.
23 deposits toner residue. At this time, as shown in FIG. 9, when the residual toner accumulation section 120 is secured in the lower area of the unit case 521, the secondary transfer unit 52 largely rotates when the door unit 70 is opened and closed. The toner accumulated in the accumulation unit 120 flows back to the cleaning brush 523 and adheres again, which may cause the secondary transfer roll 522 to be stained. For this reason, in the present embodiment, the cleaning brush 5 is provided in the unit case 521.
It is preferable to provide a partition part 121 between the arrangement part 23 and the residual toner accumulation part 120. Here, the partition 121
As shown in FIG. 9, a partition wall protruding inward may be provided in a part of the unit case 521, or a partition wall made of a separate member may be provided in the unit case 521. Is also good. Note that in FIG.
Reference numeral 22 denotes an elastic seal lip attached to the lower edge of the opening of the unit case 521 to keep the space between the secondary transfer roll 522 airtight.

Further, in the present embodiment, the direction of the brush body 523a of the cleaning brush 523 is devised. That is, in the present embodiment, FIG.
, The door unit 70, the secondary transfer unit 52
And a belt unit 23, and a driving system of the cleaning brush 523 in the secondary transfer unit 52 is shown in FIG.
As shown in (b), a drive transmission gear 131 is provided at one end of the secondary transfer roll 522, and a driven transmission gear 132 meshing with the drive transmission gear 131 is provided at one end of the rotation shaft of the cleaning brush 523. The secondary transfer roll 5
The cleaning brush 523 is driven to rotate following the rotation of the cleaning brush 22. In such an embodiment, during the setting process, the secondary transfer roll 522 causes the support shaft to abut on the edge of the V-shaped positioning groove 91 of the positioning plate 90, and the support shaft is contact-rolled by the edge. The positioning direction of the secondary transfer roll 522 is determined by moving the secondary transfer roll 522, and the rotation direction of the secondary transfer roll 522 differs depending on which edge of the positioning groove 91 is located.

For example, as shown in FIG. 11A, in a mode in which the support shaft portion 522a of the secondary transfer roll 522 abuts on the upper edge portion 91a of the positioning groove 91 and rolls downwardly. The secondary transfer roll 522 rotates counterclockwise as indicated by the arrow, and the cleaning brush 523 rotates clockwise in reverse. On the other hand, for example, FIG.
As shown in FIG. 7, the support shaft portion 522 of the secondary transfer roll 522
a is in contact with the lower edge portion 91b of the positioning groove 91 and rolls upwardly.
Reference numeral 22 rotates clockwise as indicated by an arrow, and the cleaning brush 523 rotates counterclockwise. At this time, in the present embodiment, as shown in FIG. 11C, the brush body 523a of the cleaning brush 523 is arranged in a direction in which the rotational load is smaller than the rotational direction of the secondary transfer roll 522. Note that, in an embodiment in which the cleaning blade 525 is used instead of the cleaning brush 523, FIG.
As shown in (d), the cleaning blade 525 may be arranged so as to face a direction in which the rotational load is smaller than the rotational direction of the secondary transfer roll 522. Accordingly, when the secondary transfer unit 52 is set, the secondary transfer roll 52
2 is suppressed, and the reproducibility of the position of the secondary transfer roll 522 due to the load change is kept good.

In particular, in this embodiment, the belt cleaner 53 on the side of the belt unit 23 has a cleaning blade 53a in a direction shown in FIG. Since the cleaning blade 53a is arranged in a direction in which the rotation load is reduced when the intermediate transfer belt 230 rotates in the direction of the arrow,
From the viewpoint of suppressing the influence of the rotational load by the cleaning blade 53a, the intermediate transfer belt 230 may be rotated in the above-described direction in the process of positioning the secondary transfer roll 522. In this example, specifically, as shown in FIG. 11B, for example, the support shaft portion 522a of the secondary transfer roll 522 is brought into contact with the lower edge portion 91b of the positioning groove 91 of the positioning plate 90, If the method of rotating the secondary transfer roll 522 in the direction of the arrow is employed for positioning and holding, the intermediate transfer belt 230 is moved when the secondary transfer roll 522 comes into contact with the intermediate transfer belt 230 in FIG.
It is possible to rotate the secondary transfer roll 522 in the direction of the arrow indicated by 0 (a), whereby the rotational load on the secondary transfer roll 522 can be further reduced in the process of positioning the secondary transfer roll 522. Therefore, the secondary transfer unit 52
The load fluctuation of the secondary transfer roll 522 at the time of the setting of the second transfer roll 522 is further suppressed, and the secondary transfer roll 5
The position reproducibility of No. 22 is kept good.

Second Embodiment FIG. 12 is an explanatory view showing a main part of an image forming apparatus according to a second embodiment. In the figure, the image forming apparatus according to the present embodiment has a basic configuration substantially similar to that of the first embodiment, and further sets a new force relationship acting on the door unit 70. Note that components similar to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted here. That is, in the present embodiment, as shown in FIG. 12, the unit case 521 of the secondary transfer unit 52 is rotatably supported by the door unit 70, and the unit case 5 is set in the process of setting the secondary transfer unit.
The set force F is applied to a portion of the unit case 521 remote from the rotation fulcrum 524, but the reaction force R from the rotation fulcrum 524 of the unit case 521 is applied to the rotation fulcrum 71 of the door unit 70.
The moment M around the pivot fulcrum 71 of the door unit 70 due to the reaction force of the set force F causes the door unit 70 to move the door unit 70 to the main housing 21 (see FIG. 2).
It is set to rotate to the side.

Here, as a method of setting the reaction force R from the rotation fulcrum 524 of the unit case 521 in the direction of the rotation fulcrum 71 of the door unit 70, there is a method of setting the long hole 74 of the bracket 73.
Is a circular locus m of a radius connecting the pivot point 71 of the door unit 70 and the pivot point 524 of the unit case 521 with the longitudinal direction of
May be set in the tangential direction of. Further, in this example, the force acting on the secondary transfer unit 52 when the secondary transfer unit 52 is set is, as shown in FIG. 13, the set force F from the retract mechanism 80 and the reaction force acting on the rotation fulcrum 524. R and the force K applied to the secondary transfer roll 522 side. If all the forces are set to be substantially parallel now, these forces F, R, and K are F + R + K =
There is a balance of 0. In this state, the door unit 7
Considering the moment M around 0, the door unit 70
Are external forces F and R, and R is directed toward the pivot fulcrum 71 of the door unit 70. Therefore, if the moment span up to the point of application of the set force F to the pivot fulcrum 71 is r, , M = F · r.

According to this embodiment, the reaction force R acting on the rotation fulcrum 524 receives a nip load or the like from the secondary transfer roll 522, and this reaction force R is generated at the rotation fulcrum 71 of the door unit 70. I can take it. Therefore, the door unit 70 is not unnecessarily distorted and deformed by the reaction force R. Further, since the moment M that rotates toward the main body housing 21 acts on the door unit 70, there is no concern that the door unit 70 may be displaced in the opening direction.
Therefore, the nip force of the secondary transfer roll 522 (7 to 10)
kgf), even if a reaction force R corresponding to the nip force is generated at the pivot fulcrum 71 of the door unit 70, the door unit 70 has a rigid structure capable of withstanding the nip force of about 7 to 10 kgf. There is no need to be. Also,
Since a moment M in the closing direction acts on the door unit 70, the positioning accuracy of the secondary transfer roll 522 is kept good, and the reproducibility of the position of the secondary transfer roll 522 is ensured.

In a modification of the present embodiment, as shown in FIG. 14, the reaction force R (the nip load of the secondary transfer roll 522) from the rotation fulcrum 524 of the unit case 521 of the secondary transfer unit 52, And positioning plate 9
The moment M1 around the pivot fulcrum 71 of the door unit 70 due to the reaction force load from the positioning groove 91 of 0 (R · r if the moment span from the pivot fulcrum 71 is r1)
1) and the moment M2 around the pivot fulcrum 71 of the door unit 70 due to the reaction force of the set force F (F · r2 if the moment span from the pivot fulcrum 71 is r2) is the sum of the door unit 70 The orientation may be such that it is turned to the main body housing 21 side. In this embodiment, if the nip load or the like of the secondary transfer roll 522 is received near the pivot 71 of the door unit 70, the door unit 7
0 without increasing the rigidity of the secondary transfer roll 5
The door unit 70 is not distorted and deformed due to the nip load 22 or the like.

Further, since the total of the moments acts in the direction to close the door unit 70, the reproducibility of the position of the secondary transfer roll 522 is also ensured. In particular, in the present embodiment, since the moment M1 is a component acting in the direction in which the door unit 70 is opened, the total moment itself can be suppressed smaller than that in the embodiment. Therefore, this door unit 7
Strain deformation due to the moment acting on zero is also reduced.
In this modification, the total moment may be set to substantially zero. In this case, no moment acts on the door unit 70 in the closing direction, so that the door unit 70 It can be rigid.

Third Embodiment FIG. 15 is an explanatory view showing an image forming apparatus according to a third embodiment. In the figure, an image forming apparatus according to the present embodiment has a configuration substantially similar to that of the first embodiment, and further improves maintenance workability. still,
The same components as those in the first embodiment are described in the first embodiment.
The same reference numerals are given, and the detailed description is omitted here. In this example, the belt unit 23 has a belt unit support mechanism 600. The belt unit support mechanism raises and lowers the belt unit 23 by rotating the operation arm 601 and moves the guide rail at the raised position. The belt unit 23 can be inserted and removed along 602. The photoconductor unit 30
Has a photoconductor unit support mechanism (not shown) that can be pulled out from the front side of the main body housing.

First, when replacing the secondary transfer unit 52, the secondary transfer unit 52 is removed by opening the door unit 70 as shown in FIGS. After the new secondary transfer unit 52 is set as the door unit 70 while the door unit 70 is open, the door unit 70 may be closed. At this time, as shown in FIG. 20A, when the door unit 70 is opened, the support shaft portion 522 of the secondary transfer roll 522 is opened.
a is guided upward along the positioning groove 91 of the positioning plate 90, and conversely, when the door unit 70 is closed, the support shaft 522 a of the secondary transfer roll 522 is moved downward along the positioning groove 91 of the positioning plate 90. You will be guided to the side.

When the belt unit 23 is replaced, the secondary transfer unit 52 may be left at the set position. First, as shown in FIG. 17, the operation arm 601 of the belt unit support mechanism 600 is moved forward. Side, thereby pushing the belt unit 23 upward. At this time, as shown in FIG. 21, the support shaft 5 of the secondary transfer roll 522 is
22a is separated from the positioning groove 91 of the positioning plate 90, and the belt unit 23 is
Is separated from the photosensitive drum 31. In this state,
As shown in FIGS. 18 and 21, after opening the corresponding side door 610 of the main body housing 21, the belt unit 23 may be pulled out along the guide rail 602 of the belt unit support mechanism 600.

When the belt unit 23 is mounted after the replacement, the reverse procedure of the above-described removal step may be performed. At this time, when the operation arm 601 is raised and lowered after the belt unit 23 is inserted into the main body housing 21, the positioning groove 91 of the positioning plate 90 is moved to the secondary position when the belt unit 23 is lowered. Secondary transfer roll 5 of transfer unit 52
22. When the belt cleaner 53 of the belt unit 23 is replaced, the belt cleaner 53 is replaced when the belt cleaner 53 is exposed to the outside of the main body housing 21.
The replacement work of No. 3 may be performed.

Further, when the photoconductor unit 30 is to be replaced, as shown in FIG. 19, after the belt unit 23 is raised, the front door 611 of the main body housing 21 is opened, and the photoconductor unit 30 is pulled out. do it.
When the photoconductor unit 30 is mounted, a new photoconductor unit 30 may be inserted into the main body housing 21 and then the belt unit 23 at the raised position may be lowered. At this time, as shown in FIG. 22, since only the belt unit 23 is moved up and down, the secondary transfer unit 52 can be left at the set position.

[0054]

As described above, according to the first aspect of the present invention, a transfer unit in which a transfer member and a cleaning member are incorporated in one unit case is provided, and the transfer unit is united with respect to the rotation support unit. Since the entire case can be moved, there is no relative movement of the transfer member with respect to the unit case, and accordingly, the opening area of the unit case can be set according to the size of the transfer member. The gap between them can be minimized. Therefore, even if the transfer unit is moved toward and away from the transfer unit, and the rotation support unit is opened and closed during jam clearance and maintenance, the cleaning residue in the unit case cleaned by the cleaning member is unnecessarily blown out from the opening gap. The situation can be effectively prevented, and adverse effects such as contamination of the recording material due to blowing of the cleaning residue can be effectively avoided.

Further, according to the second aspect of the present invention, in the process of setting the transfer unit, the nip load of the transfer member is received at the rotation fulcrum of the rotation support unit, and the rotation support unit is moved toward the apparatus main body. Since the moment is applied in the rotating direction, the reproducibility of the position of the transfer member can be ensured even when the rigidity of the rotating support unit is reduced.
For this reason, the transfer operation by the transfer member can be always performed satisfactorily, a defect (such as a jam) can be effectively prevented from changing the peeling posture of the recording material, and the image quality of a color image or the like is always kept good. be able to. Further, a nip load or the like of the transfer member is received in the vicinity of the rotation fulcrum of the rotation support unit, and a moment is applied in a direction for rotating the rotation support unit toward the apparatus main body, or the moment is reduced to substantially zero. By doing so, it is possible to maintain good reproducibility of the position of the transfer member while reducing the rigidity of the rotation support unit.

Further, according to the third aspect of the present invention, since the maintenance parts of the image forming engine are movably arranged while the transfer unit is arranged at the set position, compared with the maintenance work involving the movement of the transfer unit. Thus, maintenance workability can be improved.

[Brief description of the drawings]

FIGS. 1A to 1C are explanatory diagrams each showing an outline of an image forming apparatus according to the present invention.

FIG. 2 is an explanatory diagram illustrating an overall configuration of the image forming apparatus according to the first embodiment;

FIG. 3A is an explanatory diagram showing a door unit closed in the image forming apparatus according to the embodiment, and FIG. 3B is an explanatory diagram showing a state in which the door unit is opened in the image forming device. .

FIG. 4 is an explanatory diagram showing details of a secondary transfer unit used in the present embodiment.

FIG. 5A is an explanatory diagram showing a state of a secondary transfer unit when a secondary transfer roll is located at a set position;
(B) is an explanatory view showing a state of the secondary transfer unit when the secondary transfer roll is located at the retract position.

FIG. 6 is an explanatory diagram showing a drive system of the secondary transfer unit according to the embodiment.

FIG. 7A is an explanatory diagram illustrating a state of a drive system when a secondary transfer roll is located at a set position, and FIG. 7B is a diagram illustrating a state of a drive system when the secondary transfer roll is located at a retract position. FIG.

FIGS. 8A and 8B are diagrams illustrating a modification of the drive system of the secondary transfer unit according to the embodiment, and FIG. 8A is an explanatory diagram illustrating a state of the drive system when the secondary transfer roll is located at a set position;
(B) is an explanatory diagram showing a state of the drive system when the secondary transfer roll is located at the retract position.

FIG. 9 is an explanatory diagram showing a modification of the secondary transfer unit in the present embodiment.

FIG. 10A is an explanatory diagram showing a layout of a door unit, a secondary transfer unit, and a belt unit used in the embodiment, and FIG. 10B is an explanatory diagram showing a driving system of a cleaning brush of the secondary transfer unit. It is.

11A is an explanatory view showing an example of a state at the time of positioning a secondary transfer roll, FIG. 11B is an explanatory view showing another example of a state at the time of positioning the secondary transfer roll, and FIG. FIG. 4D is an explanatory diagram illustrating the direction of the brush of the cleaning brush, and FIG. 4D is an explanatory diagram illustrating a layout example when a cleaning blade is used instead of the cleaning brush.

FIG. 12 is an explanatory diagram showing a main part of an image forming apparatus used in the second embodiment.

FIG. 13 is an explanatory diagram showing a balanced state of the force of the secondary transfer unit according to the second embodiment.

FIG. 14 is an explanatory diagram showing a state of action of a moment acting on a door unit in a modification of the second embodiment.

FIG. 15 is an explanatory diagram illustrating an outline of a usage state of the image forming apparatus used in the third embodiment.

FIG. 16 is an explanatory diagram showing an example of a maintenance operation when exchanging the secondary transfer unit in the third embodiment.

FIG. 17 is an explanatory diagram showing a first step of a maintenance operation example when replacing a belt unit in the third embodiment.

FIG. 18 is an explanatory diagram illustrating a second step of a maintenance operation example when replacing the belt unit in the third embodiment.

FIG. 19 is an explanatory diagram illustrating an example of a maintenance operation when exchanging a photoconductor unit in the third embodiment.

20A is an explanatory diagram illustrating a state around the secondary transfer unit in a maintenance operation example when removing the secondary transfer unit, and FIG. 20B is a diagram illustrating a state in the maintenance operation example when mounting the secondary transfer unit. FIG. 9 is an explanatory diagram illustrating a state around a next transfer unit.

FIG. 21 is an explanatory diagram showing a state around the secondary transfer unit in a maintenance work example when the belt unit is replaced.

FIG. 22 is an explanatory diagram illustrating a state around the secondary transfer unit in a maintenance work example when the photoconductor unit is replaced.

23A is an explanatory diagram illustrating an example of an image forming apparatus in which a secondary transfer unit is provided on a conventional door unit, and FIG. 23B is an explanatory diagram illustrating a state where the door unit is opened.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Imaging engine, 2 ... Image carrier, 3 ... Transfer unit,
3a: Transfer member, 3b: Cleaning member, 3c: Unit case, 3d: Rotating fulcrum, 4: Device body, 5: Rotating support unit, 5d, 5d ': Rotating fulcrum, 6: Unit holding mechanism, 7 ... Positioning member

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H030 AA07 AB02 BB23 BB42 BB46 2H032 AA05 AA15 BA09 BA23 BA30 2H071 AA03 AA07 AA08 AA20 BA04 BA13 BA16 BA27 BA35 DA09 EA04 EA06 EA10 EA18

Claims (8)

[Claims] An image forming engine including an image carrier for carrying a visible image is pressed against a surface side of the image carrier via a recording material, and the visible image on the image carrier is collectively applied to the recording material. In an image forming apparatus having a transfer member for transferring in an apparatus main body, a rotation supporting unit rotatably supported with respect to the apparatus main body, the transfer member and a cleaning member for cleaning the transfer member are one. A transfer unit incorporated in a unit case, wherein the transfer unit is movably held with respect to the rotation support unit together with the unit case so that the transfer member can be moved toward and away from the image carrier. Image forming device. 2. The image forming apparatus according to claim 1, wherein the unit holding mechanism for holding the transfer unit rotatably supports the unit case on the rotation support unit, and raises and lowers a portion separated from the rotation center of the unit case. An image forming apparatus wherein the transfer member can be moved toward and away from the image carrier by moving the unit case up and down around the rotation center of the unit case. 3. The image forming apparatus according to claim 1, wherein the transfer unit includes a cleaning residue storage unit in the unit case, and the unit case includes a cleaning member disposition unit and a cleaning residue storage unit. An image forming apparatus, comprising a partition part for partitioning. 4. The image forming apparatus according to claim 1, wherein the transfer member of the transfer unit is positioned while rolling in contact with the positioning member during a setting process of contacting and arranging the image carrier. An image forming apparatus, wherein the image forming apparatus is arranged in a direction in which a rotational load is small with respect to a rotational direction of a transfer member that rolls in contact with a positioning member. 5. The image forming apparatus according to claim 1, further comprising a cleaning member configured to clean the image carrier, wherein the transfer member of the transfer unit is a positioning member in a setting process of being arranged in contact with the image carrier. The cleaning member of the transfer unit is disposed in a direction in which the rotational load is smaller than the rotation direction of the transfer member that rolls in contact with the positioning member, and the cleaning member of the image carrier is positioned. An image forming apparatus, wherein the image forming apparatus is arranged in a direction in which a rotation load is small with respect to a rotation direction of an image carrier that rotates in contact with a transfer member that rolls in contact with a member. 6. An image forming engine including an image carrier for carrying a visible image, is pressed against the surface side of the image carrier via a recording material, and the visible image on the image carrier is collectively applied to the recording material. An image forming apparatus having a transfer member for transferring in an apparatus main body, a rotation support unit rotatably supported with respect to the apparatus main body, and incorporating the transfer member into one unit case and forming an image on the transfer member. A transfer unit that movably holds the unit case with respect to the rotation support unit so that the unit case can be moved toward and away from the carrier. The unit holding mechanism that holds the transfer unit includes a unit case mounted on the rotation support unit. Rotationally supports and applies a setting force to a portion of the transfer unit that is away from the rotation fulcrum in the process of setting the transfer unit. The reaction force from the rotation fulcrum of the unit case is applied to the rotation fulcrum of the rotation support unit. Wherein the moment around the pivot point of the pivot support unit due to the reaction force of the set force is set in a direction to rotate the rotary support unit toward the apparatus main body. apparatus. 7. An image forming engine including an image carrier for carrying a visible image, and a pressure contact with a surface side of the image carrier via a recording material to collectively apply the visible image on the image carrier to the recording material. An image forming apparatus having a transfer member for transferring in an apparatus main body, a rotation support unit rotatably supported with respect to the apparatus main body, and incorporating the transfer member into one unit case and forming an image on the transfer member. A transfer unit that movably holds the unit case with respect to the rotation support unit so that the unit case can be moved toward and away from the carrier. The unit holding mechanism that holds the transfer unit includes a unit case mounted on the rotation support unit. The unit supports the unit and applies a setting force to a part of the unit case away from the fulcrum in the process of setting the transfer unit. The sum of the moment around the point and the moment around the pivot point of the pivoting support unit due to the reaction force of the set force is the direction in which the pivoting support unit is pivoted toward the apparatus main body, or approximately zero. An image forming apparatus, comprising: 8. An image forming engine including an image carrier for carrying a visible image, which is pressed against a surface side of the image carrier via a recording material, and collects the visible image on the image carrier onto the recording material. An image forming apparatus having a transfer member for transferring in an apparatus main body, a rotation support unit rotatably supported with respect to the apparatus main body, and incorporating the transfer member into one unit case and forming an image on the transfer member. A transfer unit that is movably held with respect to the unit case with respect to the rotation support unit so that the transfer unit can be moved toward and away from the carrier, and maintenance parts for the image forming engine in a state where the transfer unit is disposed at the set position. An image forming apparatus characterized in that maintenance parts of an image forming engine are movably disposed so that the image forming engine can be replaced.