JP2009276437A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which a developing unit is turned and separated from a photoreceptor unit and they are separately replaced, the apparatus being able to properly set a positional relationship between a photoreceptor and a developing roller even when distortion is present in the housing of a developing unit. <P>SOLUTION: The image forming apparatus turns the developing unit 20 which has the developing roller 21, around a turning point of support 22 with respect to the photoreceptor unit 10 which has the photoreceptor 11. The apparatus also locks the developing unit by means of locking members 25 and 26 so that the developing roller faces the photoreceptor in a predetermined position. In the image forming apparatus, an auxiliary member 24 for connecting the rotary shaft 21a of the developing roller and the turning point of support is disposed at one axial end of the developing roller of the developing unit separately from the housing of the developing unit. The auxiliary member is locked by a locking member 25, and the developing roller is locked so that it faces the photoreceptor. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a composite machine of these, and more particularly, to a photosensitive unit provided with a photosensitive member, a developing roller for conveying the developer to the photosensitive member. In the image forming apparatus in which the developing unit provided is rotated about the rotation fulcrum and the developing unit is provided so as to be able to approach and separate from the photosensitive unit, there is distortion in the housing of the developing unit. However, the developing roller is characterized in that it can be easily and appropriately set at a predetermined position with respect to the photosensitive member in the photosensitive unit.

  2. Description of the Related Art Conventionally, image forming apparatuses such as copiers, printers, facsimiles, and multifunction machines of these have various configurations.

  As one of such image forming apparatuses, in recent years, a photosensitive unit provided with a photosensitive member and a developing unit provided with a developing roller for transporting the developer to the photosensitive member can be brought close to and separated from each other. The photosensitive member unit and the developing unit can be individually replaced.

  Here, in order to perform appropriate image formation in the case where the photosensitive unit and the developing unit are provided so as to be close to and separated from each other and the photosensitive unit and the developing unit are individually replaced, It is necessary to appropriately set the developing roller provided in the developing unit at a predetermined position with respect to the photosensitive member provided in the photosensitive unit.

  Conventionally, as disclosed in Patent Document 1, the developing unit can be moved in parallel with respect to the photosensitive unit, and the developing unit is urged to be pressed against the photosensitive unit by a biasing member such as a spring. The developing roller in the developing unit is set at a predetermined position with respect to the photosensitive member in the photosensitive unit, and as shown in Patent Document 2, the developing unit is rotated with respect to the photosensitive unit. By rotating around a fulcrum, the developing unit can be moved closer to and away from the photosensitive unit, and by a pressing / separating member biased by a biasing member such as a spring provided in the holding member, The developing unit is urged to be pressed against the photoconductor unit, and the developing roller in the developing unit is moved against the photoconductor in the photoconductor unit. Those to be set at a predetermined position has been proposed.

  However, even when the developing roller in the developing unit is set at a predetermined position with respect to the photosensitive member in the photosensitive unit as described above, if the housing of the developing unit has distortion such as twist, the developing roller is There was a problem that the image could not be set in parallel to the photosensitive member, and the distance between one end side and the other end side of the developing roller with respect to the photosensitive member changed, making it impossible to form an appropriate image. .

  For this reason, conventionally, the developing unit is set parallel to the photosensitive member by increasing the pressing force to press the developing unit against the photosensitive unit, deforming the housing of the distorted developing unit, and developing the developing unit. The distance between the roller and the photoconductor is made constant.

However, when the force for pressing the developing unit against the photosensitive unit is increased to deform the housing of the developing unit, the photosensitive unit and the developing unit are separated from each other by separating the photosensitive unit from the developing unit. It becomes difficult to individually replace the unit, and the amount of the developer conveyed to the photosensitive member by a member provided inside the housing, for example, a developing roller as the housing of the developing unit is deformed. The regulating member or the like to be regulated is deformed, and the amount of the developer conveyed to the photosensitive member is changed to cause a problem that good image formation cannot be performed.
JP 2001-83800 A JP 2004-264791 A

  In the present invention, a photosensitive unit provided with a photosensitive member and a developing unit provided with a developing roller for transporting a developer to the photosensitive member are provided so as to be close to and away from each other, and the photosensitive unit and the developing unit are individually provided. An object of the present invention is to solve the above-described problems in an image forming apparatus that can be exchanged.

  In the present invention, the developing unit including the developing roller for transporting the developer to the photosensitive member rotates about the rotation fulcrum with respect to the photosensitive unit including the photosensitive member. In the image forming apparatus in which the image forming apparatus is provided so as to be able to approach and separate from the photosensitive unit, the developing roller in the developing unit is fixed to the photosensitive member in the photosensitive unit even when there is distortion in the housing of the developing unit. It is an object to be able to set the position easily and appropriately.

  In the present invention, in order to solve the above-described problems, a developing unit including a developing roller that conveys developer to the photosensitive member is centered on a rotation fulcrum with respect to the photosensitive unit including the photosensitive member. Is provided so that the developing unit can be moved toward and away from the photosensitive unit, and a locking member is provided for locking the developing unit so that the developing roller faces the photosensitive member at a predetermined position. In the image forming apparatus, an auxiliary member that connects the rotating shaft of the developing roller and the rotation fulcrum is provided on one end side in the axial direction of the developing roller in the developing unit, separated from the housing of the developing unit, The auxiliary member is locked by the locking member, and the developing roller is locked so that one end side of the developing roller faces the photosensitive member at a predetermined position.

  Here, in the image forming apparatus of the present invention, when the developing unit is locked by the locking member so that the developing roller faces the photoconductor at a predetermined position as described above, the locking member is connected to the auxiliary member. An engaging portion that engages with the locking member can be provided on the housing of the developing unit on the other end side in the axial direction of the developing roller.

  In the image forming apparatus of the present invention, the developing unit is locked by the locking member so that the developing roller in the developing unit faces the photosensitive member in the photosensitive unit with a required interval. be able to.

  In the image forming apparatus of the present invention, the developing unit including the developing roller for transporting the developer to the photosensitive member rotates about the rotating fulcrum with respect to the photosensitive member unit including the photosensitive member as described above. When the developing unit is locked by the locking member so that the developing unit can be moved toward and away from the photosensitive unit and the developing roller faces the photosensitive member at a predetermined position, the developing roller in the developing unit An auxiliary member for connecting the rotating shaft of the developing roller and the rotation fulcrum is provided on one end side of the developing roller separately from the housing of the developing unit, and the auxiliary member is locked by the locking member.

  As described above, when the auxiliary member for connecting the rotating shaft of the developing roller and the rotation fulcrum is separated from the developing unit on one end side in the axial direction of the developing roller, the auxiliary member can be connected to the rotating shaft of the developing roller by the auxiliary member. Even when the rotation fulcrum is maintained in a fixed positional relationship and there is distortion such as torsion in the housing of the developing unit, if the auxiliary member is locked by the locking member, the developing roller provided with the auxiliary member As with the other end side in the axial direction of the developing roller, the rotating shaft of the developing roller and the rotation fulcrum are kept in a fixed positional relationship by the auxiliary member.

  For this reason, the positions of the one end side and the other end side of the developing roller relative to the photosensitive member can be maintained without increasing the force of pressing the developing unit against the photosensitive member unit and deforming the housing of the developing unit as in the prior art. Even when the developing roller and the photosensitive member are opposed to each other with a predetermined interval, the developing roller is appropriately opposed to the photosensitive member in a predetermined position. Appropriately facing the body through a certain distance.

  As a result, in the image forming apparatus of the present invention, as in the conventional image forming apparatus that deforms the housing of the developing unit by increasing the pressing force of the developing unit against the photosensitive unit, the photosensitive unit and the developing unit It is difficult to replace the photosensitive unit and the developing unit separately, or the regulating member provided inside the housing is deformed with the deformation of the housing of the developing unit. In other words, even when the photosensitive unit and the developing unit are individually replaced, the developing roller is appropriately opposed to the photosensitive member at a predetermined position so that appropriate image formation can be performed.

  Next, an image forming apparatus according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. Note that the image forming apparatus according to the present invention is not limited to those shown in the following embodiments, and can be implemented with appropriate modifications within a range not changing the gist thereof.

  In the image forming apparatus according to this embodiment, as shown in FIG. 1, the photosensitive member 11, the charging device 12 for charging the photosensitive member 11, and the toner remaining on the surface of the photosensitive member 11 after the transfer are removed. The photosensitive unit 10 provided with the cleaning device 13 and the developing unit 20 provided with the developing roller 21 that conveys the developer to the photosensitive member 11 are made separable, and each of the four photosensitive units 10 and 10 is separated. A developing unit 20 is provided in the main body 1 of the image forming apparatus, and each developing unit 20 contains a developer containing toners of different colors of black, yellow, magenta, and cyan. In this embodiment, the photosensitive member 11 and the developing roller 21 are provided so as to face each other with a required interval. However, the photosensitive member 11 and the developing roller 21 may be provided so as to contact each other. It is.

  Here, in the image forming apparatus of this embodiment, when full-color image formation is performed, the photoreceptor 11 in each photoreceptor unit 10 is rotated, and the surface of each photoreceptor 11 is charged by the charging device 12. Then, each of the charged photoreceptors 11 is exposed according to the image data by the exposure device 31 to form an electrostatic latent image on the surface of each photoreceptor 11.

  Then, a developer containing toner of each color is conveyed to each photoconductor 11 on which the electrostatic latent image is formed in this manner by a developing roller 21 provided in each corresponding developing unit 20, and A toner image of each color corresponding to the electrostatic latent image is formed on the surface of the body 11.

  Next, the toner images of the respective colors formed on the respective photoconductors 11 are primarily transferred sequentially to an intermediate transfer body 33 in the form of an endless belt that is driven around a roller 32. A full-color toner image is formed on the intermediate transfer member 33, and a residue such as toner remaining on the surface of each photoconductor 11 after the toner image is transferred is provided in each photoconductor unit 10. Further, the cleaning device 13 is used to remove the surface of each photoconductor 11.

  The full-color toner image formed on the intermediate transfer member 33 as described above is guided to a position facing the roller-like secondary transfer device 34, and the sheet-like recording medium S is transferred to the intermediate transfer member. 33 and the secondary transfer device 34, the full-color toner image formed on the intermediate transfer body 33 by the secondary transfer device 34 is secondarily transferred to the recording medium S, while the full-color toner image Residue such as toner remaining on the surface of the intermediate transfer member 33 after the toner is transferred is removed from the surface of the intermediate transfer member 33 by the cleaning device 36.

  Then, the recording medium S to which the full color toner image is transferred as described above is guided to the fixing device 35 and the transferred full color toner image is fixed to the recording medium S, and then the full color toner image is fixed. The recording medium S is discharged.

  Here, in the image forming apparatus according to this embodiment, when the photosensitive unit 10 and the developing unit 20 are detachably provided, FIGS. 2A and 2B and FIGS. 3A and 3B are used. As shown in FIG. 4, the developing unit 20 is provided so as to be rotatable about a rotation fulcrum 22 with respect to the photoconductor 11 provided in the photoconductor unit 10.

  Then, on one end side in the axial direction of the developing roller 21 in the developing unit 20, the auxiliary member 24 is separated from the housing 23 of the developing unit 20 and connects the rotating shaft 21 a of the developing roller 21 and the rotating fulcrum 22. And an engaging portion 24b composed of a recess engaged with the first locking member 25 is provided on the extending portion 24a extending below the auxiliary member 24.

  Further, on the other end side in the axial direction of the developing roller 21 in the developing unit 20, an extending portion 23a extending downward from the housing 23 of the developing unit 20 is provided, and the second engaging portion 23a is provided in the extending portion 23a. An engaging portion 23 b made of a concave portion engaged with the member 26 is provided.

  Further, the first locking member 25 and the second locking member 26 are rotatably provided by rotation fulcrums 25b and 26b provided in the elongated holes 25a and 26a, respectively, and the elongated holes 25a and 26a. Spring members 25c and 26c are provided in the inside, respectively.

  And as shown to FIG. 2 (A), (B), the 1st locking member 25 and the 2nd locking member 26 were provided in the extension part 24a extended below the auxiliary member 24. As shown in FIG. In a state where the engaging portion 24b is engaged with the engaging portion 23b provided in the extending portion 23a extending downward from the housing 23, the first engaging member 25 and the second engaging member 26 are The developing unit 20 is urged toward the photoreceptor unit 10 by pushing the extending portion 24a of the auxiliary member 24 and the extending portion 23a extending from the housing 23 by the spring members 25c and 26c. It will be maintained in the state.

  Here, when the auxiliary member 24 is separated from the housing 23 in the developing unit 20 and is provided so as to connect the rotation shaft 21a of the developing roller 21 and the rotation fulcrum 22, as described above, Even if the housing 23 in the unit 20 is distorted such as torsion, the first locking member 25 and the second locking member 26 are provided in the extending portion 24 a extending below the auxiliary member 24. When the engaging portion 24b is engaged with the engaging portion 23b provided in the extending portion 23a extending downward from the housing 23, the above-described auxiliary is provided on one end side in the axial direction of the developing roller 21. The positional relationship between the rotation shaft 21 a of the developing roller 21 and the rotation fulcrum 22 is determined by the member 24, and the positional relationship between the rotation shaft 21 a of the developing roller 21 and the rotation fulcrum 22 on the other axial end side of the developing roller 21. Flip will be kept in the state.

  As a result, when distortion such as torsion occurs in the housing 23 in the developing unit 20, the housing 23 in the developing unit 20 is slightly distorted with respect to the photoreceptor 11 in the photoreceptor unit 10 as shown in FIG. However, the developing roller 21 is arranged in parallel with the photoconductor 11 in the photoconductor unit 10 and is held at a predetermined constant distance from the photoconductor 11.

  Therefore, when the photosensitive unit 10 and the developing unit 20 are individually replaced, even if the housing 23 of the developing unit 20 changes, the developing roller 21 appropriately faces the photosensitive member 11 with a predetermined interval. As a result, appropriate image formation can be performed.

  In the image forming apparatus described above, it is not necessary to deform the housing 23 of the developing unit 20 by strongly pressing the developing unit 20 against the photosensitive unit 10, and the developing roller 21 and the photosensitive member 11 can be easily configured. It can be set to be held at a predetermined constant interval.

  Further, since it is not necessary to strongly press the developing unit 20 against the photoconductor unit 10, the first locking member 25 and the second locking member 26 are extended below the auxiliary member 24. It is easy to disengage from the engaging portion 24b provided in the portion 24a and the engaging portion 23b provided in the extending portion 23a extending downward from the housing 23, and development is performed with the rotation fulcrum 22 as the center. By rotating the unit 20, the developing unit 20 is separated from the photosensitive unit 10, and the operation of exchanging the photosensitive unit 10 and the developing unit 20 individually can be easily performed.

  In the image forming apparatus according to this embodiment, an example of a full-color image forming apparatus in which a plurality of photosensitive units 10 and developing units 20 are provided has been described. However, one photosensitive unit 10 and one developing unit 20 are provided. It may be a monochrome image forming apparatus provided.

1 is a schematic explanatory view showing an image forming apparatus according to an embodiment of the present invention. In the image forming apparatus according to the above-described embodiment, when the developing roller provided in the developing unit is set at a predetermined position with respect to the photosensitive member provided in the photosensitive unit, the first locking member is disposed below the auxiliary member. The state in which the second locking member is locked to the engaging portion provided in the extended extension portion and the engaging portion provided in the extending portion that extends downward from the housing of the developing unit. It is the schematic explanatory drawing which showed the state stopped. In the image forming apparatus of the above-described embodiment, the first locking member is extended below the auxiliary member when the developing unit is rotated around the rotation fulcrum and the developing unit is separated from the photosensitive unit. A state in which the engagement portion provided in the extension portion is detached and a state in which the second locking member is separated from the engagement portion provided in the extension portion that extends downward from the housing of the developing unit are shown. FIG. FIG. 3 is a schematic plan view showing a state in which the developing roller provided in the developing unit is set at a predetermined position with respect to the photosensitive member provided in the photosensitive unit in the image forming apparatus according to the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body 10 Photoconductor unit 11 Photoconductor 12 Charging device 13 Cleaning device 20 Developing unit 21 Developing roller 21a Rotating shaft 22 Rotating fulcrum 23 Housing 23a Extending portion 23b Engaging portion 24 Auxiliary member 24a Extending portion 24b Engagement Joint portion 25 First locking member 25a Long hole 25b Rotating fulcrum 25c Spring member 26 Second locking member 26a Long hole 26b Rotating fulcrum 26c Spring member 31 Exposure device 32 Roller 33 Intermediate transfer member 34 Secondary transfer device 35 Fixing Device 36 Cleaning device S Recording medium

Claims (3)

  With respect to the photosensitive unit provided with the photosensitive member, the developing unit provided with the developing roller that conveys the developer to the photosensitive member rotates about the rotation fulcrum, and the developing unit moves with respect to the photosensitive unit. In an image forming apparatus provided with a locking member that is provided so as to be able to approach and separate, and that locks the developing unit so that the developing roller faces the photosensitive member at a predetermined position, the developing roller of the developing unit includes: An auxiliary member for connecting the rotation shaft of the developing roller and the rotation fulcrum is provided on one end side in the axial direction, separated from the housing of the developing unit, and the auxiliary member is locked by the locking member, An image forming apparatus, wherein one end side of the developing roller is locked so as to face a photoconductor at a predetermined position.   The image forming apparatus according to claim 1, wherein the auxiliary member provided on one end side in the axial direction of the developing roller is provided with an engaging portion that engages with the locking member, and the axial direction of the developing roller. An image forming apparatus, wherein an engaging portion that engages with the locking member is provided in a housing of a developing unit on an end side.   3. The image forming apparatus according to claim 1, wherein the developing unit is locked by the locking member so that the developing roller in the developing unit faces the photosensitive member in the photosensitive unit with a predetermined interval. An image forming apparatus.

Images