JP2008111900A - Developing device, process cartridge, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device capable of conveying developer in the axial direction of a shaft serving as the center of rotation, and to provide a process cartridge and an image forming apparatus which have such the developing device. <P>SOLUTION: The image forming apparatus 10 includes the developing device 28. The developing device 28 is rotated around one shaft 78, and has an agitator 74 for agitating the developer. The agitator 74 has a plate-like member 82, and a support member 80 supporting the plate-like member 82. The attaching faces 94a and 94c of the support member 80 and the parts of the plate-like members 82, attached to the attaching faces 94a and 94c, are inclined with respect to the shaft 78. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a developing device, a process cartridge, and an image forming apparatus.

A technique relating to a developing device, a process cartridge, and an image forming apparatus, in which a developer is stirred by a stirring unit, is known (Patent Document 1).

Japanese Patent No. 3271848

  An object of the present invention is to provide a developing device capable of moving a developer in the axial direction of a shaft serving as a center of rotation, and a process cartridge and an image forming apparatus having such a developing device.

  The first feature of the present invention is that it has a stirring portion that rotates around one axis and stirs the developer, and at least a part of the stirring portion is relative to the axial direction of the one shaft. And a developing device characterized by being inclined. Therefore, since at least a part of the stirring portion is inclined with respect to the axial direction of one shaft, the developer stirred by this inclined portion is not only in the direction perpendicular to the axial direction but also in the axial direction. Can also be transported.

  Suitably, a part of said stirring part is substantially horizontal with respect to the axial direction of said one axis | shaft. Therefore, the developer stirred in a portion substantially horizontal to the axial direction is conveyed in a direction substantially perpendicular to the axial direction.

  Preferably, the agitating part is entirely inclined with respect to the axial direction of the one shaft. Therefore, the entire part of the stirring unit can be inclined with respect to the axial direction. By stirring the developer by the stirring unit in the inclined state, the direction perpendicular to the axial direction can be obtained in a wider area. In addition, the developer can be conveyed not only in the direction along the axis of the rotation axis.

  Preferably, the stirring unit is made of an elastic body. Therefore, the developer is transported so that the stirring member is elastically deformed and is repelled when attempting to return to the original shape from the elastic deformation.

  Preferably, the agitation unit includes a change part in which an inclination with respect to the one axis changes, and a cut is formed in at least one of the change part or the vicinity of the change part of the agitation part. Therefore, even if a so-called strain is generated in the stirring portion, the stirring portion is elastically deformed in the changing portion.

  In addition, the second feature of the present invention is that it has a stirring portion that rotates around a single shaft and stirs the developer, and at least a part of the stirring portion is an axial direction of the single shaft. The developing device has a curved portion that is curved with respect to the developing device. Therefore, the developer stirred by the curved portion of the stirring unit can be transported not only in the direction perpendicular to the axial direction but also in the direction along the axis.

  Preferably, the stirring unit is made of an elastic body. Therefore, the developer is transported so that the stirring member is elastically deformed and is repelled when trying to return to the original shape from the elastic deformation.

  Preferably, a cut is formed in the curved portion. Therefore, even if a so-called strain is generated in the stirrer in the curved portion, the stirrer is elastically deformed.

  Preferably, the stirring unit has a length up to the one axis depending on a position in the axial direction of the one axis. Therefore, for example, when the edge of the stirring unit comes into contact with the inner wall of the housing that collects the developer, the angle with respect to the shaft of the stirring unit varies depending on the length to the shaft, and the angle with respect to the shaft varies. By being agitated by the agitating unit, it becomes possible to convey the developer more favorably not only in the direction perpendicular to the axial direction of the shaft but also in the direction along the axis.

  Preferably, the apparatus further includes a developer stirring chamber that houses the stirring section, and a developer conveyance path that communicates with the developer stirring chamber and that is supplied with the developer from the developer stirring chamber. The stirrer is cut to face the developer conveyance path. Therefore, the stirring member is easily deformed at the cut portion, and the developer is conveyed so as to be repelled when attempting to return to the original shape from the deformation.

  The present invention includes a process cartridge having the developing device configured as described above, and includes an image forming apparatus having such a process cartridge.

  According to the present invention, it is possible to provide a developing device capable of transporting a developer in the axial direction of a shaft serving as a center of rotation, and a process cartridge and an image forming apparatus having such a developing device.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an image forming apparatus 10 according to a first embodiment of the present invention. The image forming apparatus 10 includes an image forming apparatus main body 12, an image forming unit 14 in the image forming apparatus main body 12, a sheet supply device 51 that supplies a sheet used as a transfer material to the image forming unit 14, A power supply unit 16 is provided. Further, a sheet discharge unit 15 for discharging a sheet on which an image has been formed is provided on the upper part of the image forming apparatus main body 12.

  The image forming unit 14 is an electrophotographic system that forms a color image, and an image forming unit 18Y that forms a yellow image using a yellow developer and an image formation that forms a magenta image using a magenta developer. The image forming unit 18C includes an image forming unit 18C that forms a cyan image using a cyan developer, and an image forming unit 18B that forms a black image using a black developer. These image forming units are arranged in the order of the image forming unit 18Y, the image forming unit 18M, the image forming unit 18C, and the image forming unit 18B in this order from the lower side in the gravity direction, which is upstream in the sheet conveying direction, along the conveying belt 46 described later. Has been.

  Since the image forming units 18Y, 18M, 18C, and 18B have the same configuration although the colors of the images to be formed are different, the configuration of the image forming unit 18 will be described below. The image forming unit 18 includes a process cartridge 20. The process cartridge 20 is detachably attached to the image forming apparatus main body 12 and includes a photoconductor 24 used as an image carrier. A latent image is formed on the photosensitive member 24 by light emitted from the optical writing device 25, and the latent image is developed with a developer, whereby a developer image is formed on the surface of the photosensitive member 24.

  The developer image formed on the photoreceptor 24 is transferred to a sheet by the transfer roll 50. The four transfer rolls 50Y, 50M, 50C, and 50B are integrated with other members as a transfer unit 42, and can be attached to and detached from the image forming apparatus main body 12. The transfer unit 42 includes two support rolls 44a and 44b, a conveyance belt 46 that conveys the sheet, and an adsorption roll 48, in addition to the transfer rolls 50Y, 50M, 50C, and 50B. The support roll 44a is used as a drive roll for driving the transport belt 46, and is connected to a drive source (not shown) made of, for example, a motor. The adsorption roll 48 is used as an electrostatic adsorption unit that charges the sheet to the conveyance belt 46 in an electric charge.

  The developer images formed on the photoreceptors 24Y, 24M, 24C, and 24B are transferred to the sheet being conveyed by the conveyance belt 46 by the respective transfer rolls 50Y, 50M, 50C, and 50B, and the yellow, A full color developer image in which magenta, cyan and black developer images are superimposed is formed.

  In addition, a fixing device 52 that fixes the developer image transferred to the sheet to the sheet is provided in the upper part of the image forming apparatus main body 12. The fixing device 52 includes a heating roll 52a and a pressure roll 52b, and overheats and pressurizes the sheet passing between the heating roll 52a and the pressure roll 52b, thereby fixing the developer image on the sheet. It has become.

The sheet supply device 51 includes a sheet supply cassette 56 that is used as a sheet storage unit, a supply roll 59 that supplies sheets from the sheet supply cassette 56 toward the image forming unit 14, and a separating roll 66 that is used as a separation member. Have.
Have

  The sheet supply cassette 56 is provided detachably with respect to the image forming apparatus main body 12, and stores sheets such as plain paper and OHP sheets in a stacked manner. The separation roll 66 is pressed against the supply roll 59 and forms a contact portion with the supply roll 59. At this contact portion, the sheets supplied from the sheet supply cassette 56 are wound, separated, and double-feeded. To prevent.

  In the image forming apparatus main body 12, a conveyance path 60 that conveys the sheet supplied from the sheet supply apparatus 51 to the sheet discharge unit 15 is provided, and along the conveyance path 60 in order from the upstream side in the sheet conveyance direction. A resist roll pair 62, a transfer unit 42, a fixing device 52, and a discharge roll 64 are disposed. The discharge roll 64 discharges the sheet conveyed from the fixing device 52 to the sheet discharge unit 15.

  2 and 3 show the process cartridge 20. The process cartridge 20 includes a process cartridge main body 22, and the process cartridge main body 22 includes a photosensitive member 24, a charging device 26 having a charging roll for uniformly charging the photosensitive member 24, and charging by the charging device 26. The developing device 28 that develops the latent image written on the photoconductor 24 by the optical writing device 25 with the developer, and the developer remaining on the photoconductor 24 after the transfer of the developer image by the transfer roll 50 is cleaned. A cleaning device 56 for cleaning with the blade 58 is provided.

  The process cartridge body 22 is formed with a laser beam path 22a extending from one end portion in the horizontal direction to the vicinity of the other end portion, and the laser beam from the optical writing device 25 passes through the laser beam path 22a and reaches the photosensitive member 24. To do.

  The developing device 28 is used as a developing chamber 36 in which a developing roll 30 for developing a latent image formed on the photosensitive member 24 with a developer is disposed, and a developer agitating chamber. The developing device 28 supplies developer to the developing chamber 36. It consists of one developer supply chamber 38 and a second developer supply chamber 70 for supplying the developer to the first developer supply chamber. The developing chamber 36 and the first developer supply chamber 38 are communicated with each other through developer transport paths 37 and 39 provided in the process cartridge main body 22, and the first developer supply chamber 38 and the second developer supply chamber 70 are connected. Is communicated with the developer transport path 54. The developer collected in the second developer supply chamber 70 is supplied to the first developer supply chamber 38 by dropping the region 72 of the first developer supply chamber via the developer transport path 54. Is done.

  In the developing chamber 36, augers 32, 33, 34 used as developer conveying members are provided together with the developing roll 30 described above, and are conveyed from the developer supply chamber 38 via the developer conveying path 37. The developer that has been transferred is transported to the developer transport path 39 by the auger 34, the developer that has passed through the developer transport path 39 is transported to the auger 33, and the developer transported to the auger 33 is transported to the auger 32. And is supplied from the auger 32 to the developing roll 30.

  The first developer supply chamber 38 is located on the side of the developer chamber 36, and is used as a transport unit for transporting the developer in the first developer supply chamber 38 and agitates the developer. Agitators 74 and 76 used as the agitator are provided.

  The agitator 74 has a plate member 82 that rotates around a single shaft 78 and is used as a stirring unit, and a support member 80 that supports the plate member 82. The support member 80 has projecting portions 84 and 84 formed at both ends in the longitudinal direction, and the projecting portions 84 and 84 are rotatably supported on the side plate of the process cartridge main body 22. The plate-like member 82 is made of, for example, an elastic body such as resin and is made of a material having elasticity and flexibility, and stirs the developer in the first developer supply chamber 38 and supplies the developer. The developer in the chamber 38 is transported toward the developer transport path 37 and supplied. The edge of the plate-like member 82 can be in contact with the inner wall of the process cartridge main body 22, and the plate-like member 82 is in the position where the edge is in contact with the inner wall of the process cartridge main body 22. It is in a folded state.

  The agitator 76 rotates around a single shaft 86 and has a plate-like member 90 used as a stirring unit and a support member 88 that supports the plate-like member 90. The support member 88 has protrusions 92 and 92 formed at both ends in the longitudinal direction, and the protrusions 92 and 92 are rotatably supported by the side plate of the process cartridge main body 22. The plate-like member 90 is made of, for example, an elastic body such as a resin and is made of a material having elasticity and flexibility. The plate-like member 90 agitates the developer and conveys and supplies the developer toward the agitator 74. . The edge of the plate-like member 90 can abut on the inner wall of the process cartridge main body 22, and the plate-like member 82 is in the position where the edge of the edge is in contact with the inner wall of the process cartridge main body 22. It is in a folded state.

  4 and 5 show the agitator 74. As shown in FIGS. 4 and 5, the support member 80 has an attachment surface 94 used as an attachment portion to which the plate-like member 82 is attached, and is attached to the attachment surface 94 by a method such as pasting. A member 82 is attached. The mounting surface 94 includes three mounting surfaces 94a, 94b, and 94c arranged in the longitudinal direction of the agitator 74, and one plate-like member 82 is pasted so as to straddle the mounting surfaces 94a, 94b, and 94c. . The mounting surface 94 b is substantially parallel to the shaft 78, and the mounting surface 94 b is not inclined with respect to the shaft 78. On the other hand, the mounting surfaces 94 a and 94 c are inclined with respect to the shaft 78. That is, as shown in FIG. 3, the mounting surface 94 a has an angle θ <b> 1 with respect to the shaft 78, and the mounting surface 94 c has an angle θ <b> 2 with respect to the shaft 78.

  The plate-like member 82 is formed with a fold 82e used as a changing portion at a boundary line portion between a portion 82c attached to the attachment surface 94c and a portion 82b attached to the attachment surface 94b. In part, the inclination with respect to the axis 78 changes. Similarly, the portion 82b attached to the attachment surface 94b of the plate-like member 82 and the portion 82a attached to the attachment surface 94c are also formed with a fold 82d used as a changing portion. The inclination of the plate-like member 82 with respect to the shaft 78 is changed.

  Thus, the attachment surface 94c is formed so as to be inclined with respect to the shaft 78, and the plate-like member 82 is attached to the attachment surface 94c, and the developer is pressed and conveyed by the plate-like member 82. Therefore, the portion of the plate-like member 82 below the portion attached to the mounting surface 94 c in FIG. 4 presses the developer in a direction inclined with respect to the shaft 78 by the angle θ2. That is, the developer receives a pressing force having not only a component in a direction perpendicular to the axis 78 but also a component in a direction along the axis 78 as indicated by an arrow a in FIG. Further, the lower part in FIG. 4 than the part attached to the mounting surface 94 a of the plate-like member 82 presses the developer in the direction inclined by the angle θ 1 with respect to the shaft 78. Therefore, as shown by the arrow b in FIG. 3, the developer receives a pressure having not only a component in a direction perpendicular to the axis 78 but also a component in a direction along the axis 78. The developer is transported in the direction of the developer transport path 37 by receiving a pressing force having a component in the direction of the shaft 78.

  As described above, in the agitator 74, the mounting surfaces 94 a and 94 c that are part of the mounting surface to which the plate-like member 82 of the support member 80 is attached are inclined with respect to the shaft 78. The developer is conveyed not only in the direction perpendicular to the shaft 78 but also in the direction along the shaft 78.

  Cuts 91 are formed in the vicinity of the folds 82d and 82e of the plate-like member 82, respectively. In this embodiment, the cut 91 is formed substantially perpendicular to the shaft 78, but the cut 91 may be formed so as to be inclined with respect to the shaft 78. Further, in each of the embodiments, the cut 91 is formed in the vicinity of the folds 82d and 82e, but the cut 91 may be formed in the folds 82d and 82e instead of or in addition to this. By forming the notch 91, the plate-like member 82 is bent at the folds 82d and 82e, so that the plate-like member 82 is soaked in the vicinity of the folds 82d and 82e or the folds 82d and 82e. It is avoided that the plate-like member 82 is hardly elastically deformed.

  A notch 93 is formed in the portion 82 b of the plate-like member 82. The cut 93 is formed substantially perpendicular to the shaft 78, but the cut 91 may be formed so as to be inclined with respect to the shaft 78. The portion 82b is disposed at a position facing the developer conveyance path 37 when the portion 82b is incorporated in the process cartridge main body 22 (see FIG. 3). By forming the notch 91 in the plate-like member 82 so as to face the developer conveyance path 37, the plate-like member 82 is easily elastically deformed at the portion where the notch 91 is formed, and the elasticity of the plate-like member 82 and The developer is supplied to the developer conveyance path 37 such that the developer is repelled by flexibility.

  FIG. 6 shows an agitator 76. The support member 88 of the agitator 76 has an attachment surface 96 used as an attachment portion to which the plate-like member 90 is attached, and the plate-like member 90 is attached to the attachment surface 96 by, for example, affixing. In the agitator 74, only the mounting surface 94 a and the mounting surface 94 c among the mounting surfaces 94 to which the plate-like member 82 is mounted are inclined with respect to the shaft 78. On the other hand, in the agitator 76, the entire mounting surface 96 has a certain inclination with respect to the shaft 86. That is, as shown in FIG. 3, the mounting surface 96 has an angle θ <b> 3 with respect to the axis 86.

  As described above, the mounting surface 96 is formed on the agitator 76 so as to be inclined with respect to the shaft 86, and the plate member 90 is attached to the mounting surface 96, and the developer is pressed by the plate member 90. Is done. Therefore, the developer is pressed not only in the direction perpendicular to the axis 86 but also in the direction along the axis 86 as indicated by an arrow c in FIG. Then, the developer supplied to the region 72 from the second developer supply chamber 70 (see FIG. 2) by receiving a force in the direction along the shaft 78 causes the depth of the first developer supply chamber 38 to be increased. It is conveyed in a direction having a component (upward in FIG. 3).

  As described above, since the mounting surface 96 on which the plate-like member 90 of the support member 88 is attached to the agitator 76 is inclined with respect to the shaft 86, the developer is received by being pressed by the plate-like member 90. Similarly to the movement of the developer by the agitator 74, the movement in the direction along the axis 78 is performed in the same manner as in the direction perpendicular to the axis 78.

  FIG. 7 shows a second embodiment of the agitator 74. In the first embodiment described above, the support member 80 has a shape such that the mounting surface 94b protrudes from the axial direction among the mounting surfaces 94a, 94b, 94c. In the embodiment, the mounting surface 94b is shaped to form a recess in the axial direction. In the agitator 74 according to the first embodiment, as indicated by arrows a and b in FIG. 3, in the axial direction of the shaft 78, the developer is conveyed so as to gather from the outside to the mounting surface 94 b side. It was. On the other hand, in the agitator 74 according to the second embodiment, the developer is conveyed so as to be pushed out from the mounting surface 94b side. In addition, about the same part as 1st Embodiment, the same number is attached | subjected to FIG. 6, and description is abbreviate | omitted.

  FIGS. 8 and 9 show a third embodiment of the agitator 74. In the first and second embodiments described above, the surfaces 94 a and 94 c of the attachment surface 94 to which the plate-like member 82 of the support member 80 is attached have an inclination with respect to the shaft 78. On the other hand, in the third embodiment, the attachment surface 94 to which the plate-like member 82 of the support member 80 is attached is curved with respect to the axial direction of the shaft 78, for example, has an arc shape. The plate-like member 82 attached to the attachment surface 94 is in a curved state, the curved plate-like member 82 is used as a curved portion, and the developer is pressed by being pressed by the curved plate-like member 82. It is conveyed not only in the direction orthogonal to the shaft 78 but also in the direction along the shaft 78.

  In the first embodiment described above, the notch 91 is formed in the vicinity of the folds 82d and 82e of the plate-like member 82, and the notch 93 is formed in the portion 82b substantially parallel to the shaft 78. In the embodiment, a notch 95 is formed across the entire region of the shaft 78 of the plate-like member 82. In the third embodiment, since the plate-like member 82 is curved over the entire region of the shaft 78, a so-called strain is generated over the entire region of the shaft 78, so that it is difficult to elastically deform. By forming, it can be made to elastically deform well.

  The notch 95 is also formed in the plate-like member 82 at a position facing the developer transport path 37 when the agitator 74 is assembled to the process cartridge main body 22. Therefore, the developer is repelled by the elasticity and flexibility of the plate member 82 and supplied to the developer transport path 37. In addition, about the same part as 1st Embodiment, the same number is attached | subjected to FIG. 8 and 9, and description is abbreviate | omitted.

  FIG. 10 shows a fourth embodiment of the agitator 74. In the agitator 76 according to the fourth embodiment, the length L of the plate-like member 82 from the end edge of the protruding portion protruding from the mounting surface 94 to the shaft 78 differs depending on the position of the shaft 78 in the axial direction. Specifically, the length L is the maximum on one end side in the axial direction of the shaft 78, the length L is the minimum on the other end side, and the length L is linearly changed at an intermediate position. . The fourth embodiment of the agitator 76 can be used in combination with the first to third embodiments of the agitator 76. In the first to third embodiments, the length L varies depending on the position of the shaft 78 in the axial direction. You may do it. Further, in the agitator 76 (see FIG. 6), the length L may be varied depending on the position of the shaft 78 in the axial direction. In addition, about the same part as 1st Embodiment, the same number is attached | subjected to FIG. 10, and description is abbreviate | omitted.

  As described above, the present invention can be applied to an image forming apparatus such as a copying machine, a facsimile machine, and a printer, and a process cartridge and a developer conveying apparatus mainly used for these.

1 is a cross-sectional view illustrating a configuration of an image forming apparatus according to a first embodiment of the present invention. It is sectional drawing which shows the process cartridge which concerns on the 1st Embodiment of this invention. FIG. 3 is a cross-sectional view showing the process cartridge according to the first embodiment of the present invention and showing the AA cross section in FIG. 2. It is a perspective view which shows the 1st developer conveyance member used for the 1st Embodiment of this invention. It is a rear view which shows the 1st developer conveyance member used for the 1st Embodiment of this invention. It is a perspective view which shows the 2nd developer conveyance member used for the 1st Embodiment of this invention. It is a perspective view which shows the developer conveyance member used for the 2nd Embodiment of this invention. It is a perspective view which shows the developer conveyance member used for the 3rd Embodiment of this invention. The developer conveyance member used for the 3rd Embodiment of this invention is shown, FIG. 9 (a) is a top view, FIG.9 (b) is a rear view. It is a perspective view which shows the developer conveyance member used for the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Image forming apparatus main body 14 Image forming part 22 Process cartridge main body 28 Developing apparatus 74 Agitator 76 Agitator 78 Shaft 80 Support member 82 Plate member 86 Shaft 88 Support member 90 Plate member 91 Notch 93 Notch 94 Mounting surface 95 Notch 96 Mounting surface

Claims (12)

Having a stirrer that rotates around one axis and stirs the developer;
At least a part of the stirring unit is inclined with respect to the axial direction of the one shaft.   The developing device according to claim 1, wherein a part of the stirring unit is substantially horizontal with respect to an axial direction of the one shaft.   The developing device according to claim 1, wherein all of the agitating portion is inclined with respect to an axial direction of the one shaft.   The developing device according to claim 3, wherein the stirring unit is made of an elastic body. The stirring unit has a changing unit in which the inclination with respect to the one axis changes,
The developing device according to claim 4, wherein a cut is formed in at least one of the changing portion or the vicinity of the changing portion of the stirring portion. Having a stirrer that rotates around one axis and stirs the developer;
At least a part of the stirring unit has a curved portion that is curved with respect to the axial direction of the one shaft.   The developing device according to claim 6, wherein the stirring unit is made of an elastic body.   8. The developing device according to claim 7, wherein a cut is formed in the curved portion.   The developing device according to claim 1, wherein the stirring unit has a length up to the one axis that varies depending on an axial position of the one axis. A developer stirring chamber for storing the stirring section;
A developer conveying path that communicates with the developer agitating chamber and is supplied with the developer from the developer agitating chamber;
Further comprising
The developing device according to claim 1, wherein the stirring unit has a cut formed facing the developer conveyance path.    A process cartridge comprising the developing device according to claim 1.   An image forming apparatus comprising the process cartridge according to claim 11.

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