JP2007140080A - Method for manufacturing developer carrier, developer carrier, developing device, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer carrier manufacturing method for manufacturing a developer carrier achieving improvement in durability and having excellent developing characteristics, and also provide the developer carrier, a developing device, and an image forming apparatus. <P>SOLUTION: The method for manufacturing the developer carrier made cylindrical or columnar and having a rugged part for carrying developer on its outer peripheral surface, includes: a stage for preparing cylindrical or columnar base material 300A to be the developer carrier; and a stage for forming the rugged part by pressing a first die 220 and a second die 230 for forming the rugged part on the outer peripheral surface of the base material 300A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a developer carrier, a developer carrier, a developing device, and an image forming apparatus.

Image forming apparatuses such as printers, copiers, and facsimile machines that employ an electrophotographic method are applied to a recording medium such as paper by a series of image forming processes such as a charging process, an exposure process, a development process, a transfer process, and a fixing process. Then, an image made of toner is formed.
Such an image forming apparatus is provided with a developing device provided with a developing roller (developer carrying member) that is disposed opposite to a photosensitive member carrying an electrostatic latent image and carries toner. Such a developing device visualizes the latent image as a toner image by applying toner from the developing roller to the photoconductor in the developing step.

2. Description of the Related Art Conventionally, as a developing roller provided in such a developing device, an outer peripheral surface of which is roughened by blasting to form irregularities is known (for example, see Patent Document 1). Thereby, the toner can be reliably carried on the developing roller.
However, since the developing roller according to Patent Document 1 forms the unevenness as described above by blasting, the shape, size, and arrangement of the formed unevenness are not uniform, and the development characteristics may be deteriorated. is there.

For example, the distribution of the amount of toner carried on the outer peripheral surface of the developing roller becomes non-uniform, and the rolling property (ease of rolling) of toner particles on the outer peripheral surface of the developing roller becomes non-uniform. For this reason, when the toner on the developing roller is frictionally charged by the regulating blade, a toner charging failure or a conveyance failure may occur locally. As a result, development defects such as so-called fogging occur.
Further, the unevenness obtained by the blasting process is relatively sharp at the tip of the convex part, and thus, for example, it easily wears due to contact with the above-described regulation blade and the like. Will end up with low durability.

JP 2003-263018 A

  An object of the present invention is to provide a developer carrying body, a developer carrying body, a developing device, and an image forming apparatus capable of producing a developer carrying body having excellent development characteristics while improving durability. Is to provide.

Such an object is achieved by the present invention described below.
The method for producing a developer carrier of the present invention is a method for producing a developer carrier having a cylindrical shape or a columnar shape and having an uneven portion for carrying the developer on the outer peripheral surface thereof.
Preparing a cylindrical or columnar base material to be the developer carrier;
And a step of forming the concavo-convex portion by pressing a mold for forming the concavo-convex portion on the outer peripheral surface of the base material.

  Thereby, regular and uniform uneven portions can be formed on the outer peripheral surface of the developer carrier. Therefore, the obtained developer carrying member can carry a uniform and optimum amount of developer on the outer circumferential surface thereof, and the developer rollability (ease of rolling) on the outer circumferential surface of the developer carrying member. ) Can also be uniform. As a result, it is possible to prevent local charging failure and conveyance failure of the developer and to exhibit excellent development characteristics.

  In addition, since the concavo-convex portion is formed using a mold, the obtained concavo-convex portion can have a relatively thick tip at the tip of the concavo-convex portion, unlike the case obtained by blasting. Such a concavo-convex part has excellent mechanical strength. In particular, since the mechanical strength of the portion pressed by the mold is improved, the obtained concavo-convex portion has excellent mechanical strength even compared with that obtained by processing such as cutting. The developer carrying member having such a concavo-convex portion can exhibit excellent durability. In addition, if the width of the tip of the convex and concave portions is relatively large, there will be little change in shape even if it is worn out. Can do.

In the method for producing a developer carrying member of the present invention, the concavo-convex portion includes a plurality of first grooves formed in parallel with each other and a plurality of first grooves formed in parallel with each other while intersecting the first grooves. It is preferable that it is composed of two grooves.
Thereby, a regular and uniform uneven | corrugated | grooved part can be easily formed using the type | mold of a comparatively simple shape.

In the method for producing a developer carrying member of the present invention, it is preferable that the formation of the first groove and the formation of the second groove are performed using different molds.
Thereby, it is only necessary to provide each mold with a plurality of protrusions parallel to each other, and the shape of the mold can be simplified.
In the method for producing a developer carrying member of the present invention, the first groove and / or the second groove is formed by pressing the mold in a plurality of times at the same location on the outer peripheral surface of the substrate. It is preferable.
Thereby, since the outer peripheral surface of a base material is gradually plastically deformed, the residual stress in the base material after a process can be reduced, and the mechanical strength of an uneven | corrugated | grooved part can be made more excellent. Moreover, a uniform uneven | corrugated | grooved part can be formed more reliably.

In the method for producing a developer carrying member of the present invention, it is preferable to use the same mold for each pressing.
As a result, the cost for the mold can be suppressed, and as a result, the cost of the resulting developer carrier can be reduced.
In the method for producing a developer carrying member of the present invention, it is preferable to use different molds for each pressing.
Thereby, the uneven | corrugated | grooved part of a desired shape can be formed by selecting the type | mold used for each time suitably.

In the method for producing a developer carrying member of the present invention, it is preferable that the mold used at each time has protrusions for forming the first groove and / or the second groove, and the widths thereof are different from each other. .
Thereby, when forming an uneven | corrugated | grooved part, the processability with respect to a base material, durability of a type | mold, etc. can be improved by selecting suitably the type | mold used for each time.
In the method for producing a developer carrying member of the present invention, the width of the ridge of the mold used for the (n + 1) th time is preferably smaller than the width of the ridge of the mold used for the nth time (where n is a natural number of 2 or more). is there.).
Thereby, the uneven | corrugated | grooved part of a desired shape can be formed, reducing the residual stress which arises in a base material more. In addition, the durability of the mold can be improved.

In the method for producing a developer carrying member of the present invention, it is preferable that the height of the protrusions of the mold used for the final round is smaller than the depth of the recesses of the uneven portions.
As a result, since the concave portion of the mold presses the tip of the convex portion of the concave and convex portion at the time of the final press, the tip shape of the convex portion of the concave and convex portion obtained is adjusted to a desired shape, and the strength of the tip is increased. Can be improved.

In the developer carrying member manufacturing method of the present invention, when the pitch between the first grooves and / or the second groove is p, p may be smaller than the resolution pitch used. preferable.
Thereby, the obtained developer carrying member can prevent unevenness of the toner image obtained by development.

In the method for producing a developer carrying member of the present invention, when the depth of the first groove and / or the second groove is D and the average particle diameter of the developer is d, D / d is: It is preferable that it is 0.5-2.
As a result, the obtained developer carrying member can carry the developer in a uniform and optimum amount on the uneven portion.

In the method for producing a developer carrying member of the present invention, when the width of the first groove and / or the second groove is W and the average particle diameter of the developer is d, W / d is 2 It is preferably ~ 20.
As a result, the obtained developer carrying member can carry the developer in a uniform and optimum amount on the uneven portion.

The developer carrying member of the present invention is manufactured using the manufacturing method of the present invention.
Thereby, it is possible to provide a developer carrying member excellent in development characteristics and durability.
The developing device of the present invention includes the developer carrier of the present invention, and the developer carrier is in contact with or in close proximity to the latent image carrier that bears the latent image, from the developer carrier. The latent image is visualized as a developer image by applying a developer to the latent image carrier.
Thereby, it is possible to provide a developing device having excellent development characteristics and durability.
The image forming apparatus of the present invention is an image forming apparatus that forms an image on a recording medium by a series of image forming processes including charging, exposure, development, transfer, and fixing.
The developing device of the present invention is provided.
Thereby, it is possible to provide an image forming apparatus excellent in development characteristics and durability.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a method for producing a developer carrier, a developer carrier, a developing device, and an image forming apparatus according to the present invention will be described with reference to the accompanying drawings.
<Image forming apparatus>
First, an image forming apparatus of the present invention, that is, an image forming apparatus including the developing device of the present invention will be briefly described.

FIG. 1 is a schematic cross-sectional view of the overall configuration showing an embodiment of an image forming apparatus according to the present invention.
An image forming apparatus 10 according to this embodiment shown in FIG. 1 records an image on a recording medium mainly by a series of image forming processes including exposure, development, transfer, and fixing. As shown in FIG. 1, the image forming apparatus 10 has a photosensitive member 20 that carries an electrostatic latent image and rotates in the direction of the arrow in the figure. An exposure unit 40, a developing unit 50, a primary transfer roller 60, and a cleaning unit 75 are provided. In addition, the image forming apparatus 10 is provided with a paper feed tray 82 for storing a recording medium P such as paper at the bottom in FIG. The next transfer roller 80 and the fixing device 90 are sequentially arranged along the conveyance direction of the recording medium P. Further, in the image forming apparatus 10, when an image is formed on both sides of a recording medium, the recording medium P fixed on one side by the fixing device 90 is reversed and returned to the secondary transfer roller 80. The conveyance part 88 is provided.

The photoconductor 20 has a cylindrical conductive substrate (not shown) and a photosensitive layer (not shown) formed on the outer peripheral surface thereof, and can rotate around the axis in the direction of the arrow in FIG. It has become.
The charging unit 30 is a device for uniformly charging the surface of the photoconductor 20 by corona charging or the like.
The exposure unit 40 receives image information from a host computer such as a personal computer (not shown) and irradiates a laser on the uniformly charged photoreceptor 20 to form an electrostatic latent image. It is a device to do.

  The developing unit 50 has four developing devices, a black developing device 51, a magenta developing device 52, a cyan developing device 53, and a yellow developing device 54. These developing devices are converted into latent images on the photosensitive member 20. The latent image is visualized as a toner image (developer image) by selectively using correspondingly. In this apparatus, as a developer, the black developing device 51 is black (K) toner, the magenta developing device 52 is magenta (M) toner, the cyan developing device 53 is cyan (C) toner, and the yellow developing device 54 is yellow (Y). Development is performed using toner.

  The YMCK developing unit 50 in the present embodiment is rotatable so that the above-described four developing devices 51, 52, 53, 54 are selectively opposed to the photoconductor 20. Specifically, in this YMCK developing unit 50, four developing devices 51, 52, 53, and 54 are respectively held by four holding portions 55a, 55b, 55c, and 55d of a holding body 55 that can rotate around a shaft 50a. The four developing devices 51, 52, 53, and 54 are selectively opposed to the photoconductor 20 while maintaining the relative positional relationship by the rotation of the holding body 55. Each of the developing devices 51, 52, 53, and 54 includes a developer carrier manufactured using the method for manufacturing a developer carrier of the present invention. The developing devices 51, 52, 53, and 54 will be described later in detail.

The intermediate transfer member 61 has an endless belt-like intermediate transfer belt 70, and this intermediate transfer belt 70 is stretched by a primary transfer roller 60, a driven roller 72, and a drive roller 71, and is rotated by the rotation of the drive roller 71. 1 is driven to rotate in the direction of the arrow shown in FIG.
The primary transfer roller 60 is a device for transferring a single color toner image formed on the photoconductor 20 to the intermediate transfer belt 70.

  On the intermediate transfer belt 70, a toner image of at least one of black, magenta, cyan, and yellow is carried. For example, when a full-color image is formed, four color toner images of black, magenta, cyan, and yellow are sequentially formed. The toner images are transferred to form a full-color toner image. In the present embodiment, the drive roller 71 also functions as a backup roller for the secondary transfer roller 80 described later. Further, the primary transfer roller 60, the driving roller 71, and the driven roller 72 are supported by the base body 73.

The secondary transfer roller 80 is a device for transferring a single-color or full-color toner image formed on the intermediate transfer belt 70 to a recording medium P such as paper, film, or cloth.
The fixing device 90 is a device for fusing the toner image to the recording medium P and fixing it as a permanent image by heating and pressing the recording medium P that has received the transfer of the toner image.

The cleaning unit 75 has a rubber cleaning blade 76 that contacts the surface of the photoconductor 20 between the primary transfer roller 60 and the charging unit 30, and the toner image is transferred onto the intermediate transfer belt 70 by the primary transfer roller 60. Then, the toner remaining on the photoreceptor 20 is scraped off and removed by the cleaning blade 76.
The conveyance unit 88 reverses the front and back of the conveyance roller pair 88A and 88B for nipping and conveying the recording medium P fixed on one surface by the fixing device 90 and the conveyance medium pair 88A and 88B. And a conveyance path 88 </ b> C for guiding the registration roller 86. As a result, when an image is formed on both sides of the recording medium, the recording medium P fixed on one side by the fixing device 90 is reversed and returned to the secondary transfer roller 80.

Next, the operation of the image forming apparatus 10 configured as described above will be described.
First, in response to a command from a host computer (not shown), the photosensitive member 20, the developing roller (not shown) provided in the developing unit 50, and the intermediate transfer belt 70 start to rotate. The photoreceptor 20 is sequentially charged by the charging unit 30 while rotating.
The charged area of the photoconductor 20 reaches the exposure position as the photoconductor 20 rotates, and the exposure unit 40 forms a latent image corresponding to the image information of the first color, for example, yellow Y, in the area. .

The latent image formed on the photoconductor 20 reaches the development position as the photoconductor 20 rotates, and is developed with yellow toner by the yellow developing device 54. As a result, a yellow toner image is formed on the photoreceptor 20. At this time, in the YMCK developing unit 50, the yellow developing device 54 faces the photoconductor 20 at the developing position.
The yellow toner image formed on the photoconductor 20 reaches the primary transfer position (that is, the portion where the photoconductor 20 and the primary transfer roller 60 face each other) as the photoconductor 20 rotates. Transfer (primary transfer) is performed on the transfer belt 70. At this time, a primary transfer voltage (primary transfer bias) having a polarity opposite to the charging polarity of the toner is applied to the primary transfer roller 60. During this time, the secondary transfer roller 80 is separated from the intermediate transfer belt 70.

  The same processing as described above is repeatedly executed for the second color, the third color, and the fourth color, so that the toner images of the respective colors corresponding to the respective image signals are transferred onto the intermediate transfer belt 70 in an overlapping manner. The As a result, a full-color toner image is formed on the intermediate transfer belt 70.

On the other hand, the recording medium P is conveyed from the paper feed tray 82 to the secondary transfer roller 80 by the paper feed roller 84 and the registration roller 86.
The full-color toner image formed on the intermediate transfer belt 70 reaches the secondary transfer position (that is, the portion where the secondary transfer roller 80 and the driving roller 71 face each other) as the intermediate transfer belt 70 rotates, and the secondary transfer. The image is transferred (secondary transfer) to the recording medium P by the roller 80. At this time, the secondary transfer roller 80 is pressed against the intermediate transfer belt 70 and a secondary transfer voltage (secondary transfer bias) is applied.

The full-color toner image transferred to the recording medium P is heated and pressurized by the fixing device 90 and fused to the recording medium P. Thereafter, the recording medium P is discharged to the outside of the image forming apparatus 10 by the discharge roller pair 87.
On the other hand, after the primary transfer position has elapsed, the toner adhering to the surface of the photoconductor 20 is scraped off by the cleaning blade 76 of the cleaning unit 75 to prepare for charging for forming the next latent image. The toner that has been scraped off is collected by a residual toner collecting section in the cleaning unit 75.

  In the case of forming an image on both sides of the recording medium, the recording medium P fixed on one side by the fixing device 90 is once sandwiched between the discharge roller pair 87, and then the discharge roller pair 87 is driven in reverse. By driving the conveyance roller pair 88A, 88B, the recording medium P is turned upside down through the conveyance path 88C and returned to the secondary transfer roller 80, and an image is printed on the other surface of the recording medium P by the same operation as described above. Form.

<Developing device>
Next, the developing devices 51, 52, 53, and 54 of the developing unit 50 will be described in detail. The developing devices 51, 52, 53, and 54 are different in toner to be used, but have the same configuration except that, and therefore, the yellow developing device 54 will be representatively described below with reference to FIG.
FIG. 2 is a schematic cross-sectional view showing a schematic configuration of the developing device of the present invention.
A yellow developing device 54 shown in FIG. 2 includes a housing 540 that stores toner T (yellow toner) as a developer, a developing roller 510 that is a developer carrying member, and a toner supply roller 550 that supplies toner T to the developing roller 510. And a regulating blade 560 that regulates the layer thickness of the toner T carried on the developing roller 510.

  The housing 540 stores the toner T in a storage portion 530 formed as an internal space thereof. In the housing 540, the toner supply roller 550 and the developing roller 510 are supported so as to rotate in pressure contact with each other at an opening formed in the lower portion of the housing portion 530 and in the vicinity thereof. A regulating blade 560 is attached to the housing 540 and is in pressure contact with the developing roller 510. Further, a seal member 520 for preventing leakage of toner from between the housing 540 and the developing roller 510 in the opening is attached to the housing 540.

  The development roller 510 conveys the toner T to a development position (hereinafter, simply referred to as “development position”) that is a facing portion between the development roller 510 and the photoconductor 20 while carrying the toner T on the outer peripheral surface thereof. . Further, the developing roller 510 has a cylindrical shape and is rotatable around its axis. In the present embodiment, the developing roller 510 rotates in a direction opposite to the rotation direction of the photoconductor 20. The developing roller 510 will be described in detail later.

In this embodiment, the developing roller 510 and the photoconductor 20 face each other in a non-contact state with a minute gap during development by the yellow developing device 54. Then, by applying an alternating electric field between the developing roller 510 and the photosensitive member 20, the toner T is caused to fly from the developing roller 510 to the photosensitive member 20, and the latent image on the photosensitive member 20 is developed.
The toner supply roller 550 supplies the toner T stored in the storage unit 530 to the developing roller 510. The toner supply roller 550 is made of polyurethane foam or the like, and is pressed against the developing roller 510 in an elastically deformed state. In the present embodiment, the toner supply roller 550 rotates in the direction opposite to the rotation direction of the developing roller 510. The toner supply roller 550 not only has a function of supplying the toner T stored in the storage unit 530 to the developing roller 510, but also peels off the toner T remaining on the developing roller 510 after the development from the developing roller 510. It also has a function.

The regulating blade 560 regulates the layer thickness of the toner T carried on the developing roller 510 and, at the time of regulation, applies a charge to the toner T carried on the developing roller 510 by frictional charging. This regulating blade 560 also functions as a seal member on the upstream side of the developing position in the rotation direction of the developing roller 510.
The regulating blade 560 includes a rubber portion 560a as a contact member that is contacted along the axial direction of the developing roller 510, and a rubber support portion 560b as a support member that supports the rubber portion 560a. . The rubber part 560a is made of silicon rubber, urethane rubber or the like as a main material, and the rubber support part 560b also has a function of urging the rubber part 560a toward the developing roller 510. A sheet-like thin plate having elasticity) is used. One end of the rubber support portion 560 b is fixed to the blade support metal plate 562. The blade support metal plate 562 is attached to the housing 540, and the seal member 520 is also attached to the housing 540. Further, with the developing roller 510 attached, the rubber portion 560a is pressed against the developing roller 510 by the elastic force due to the bending of the rubber support portion 560b.

In the present embodiment, a blade back member 570 is provided on the side opposite to the developing roller 510 side of the regulating blade 560 to prevent the toner T from entering between the rubber support portion 560b and the housing 540. The rubber portion 560a is pressed against the developing roller 510, and the rubber portion 560a is pressed against the developing roller 510.
In this embodiment, the free end portion of the regulating blade 560, that is, the end portion opposite to the side supported by the blade support metal plate 562, is not contacted with the developing roller 510 at the end edge. It is in contact with the developing roller 510 at a slightly separated site. The regulating blade 560 is disposed so that the tip thereof faces the upstream side in the rotation direction of the developing roller 510, and is in a so-called counter contact.

<Developer carrier>
Here, based on FIG. 3 and FIG. 4, the developing roller 510 which is an example of the developer carrier of the present invention will be described in detail.
3 is a plan view showing a schematic configuration of a developer carrier provided in the developing device shown in FIG. 2, and FIG. 4 is an enlarged sectional view taken along line AA in FIG.
The developing roller 510 shown in FIG. 3 has a cylindrical main body 300 and bearings 310 that protrude from both ends of the main body 300.

  On the outer peripheral surface 301 of the main body 300, as shown in FIG. 3, the concavo-convex portion 2 for carrying the toner is formed. The concavo-convex portion 2 includes a plurality of first grooves 21 that are substantially parallel to each other and a plurality of second grooves 22 that intersect the first grooves 21 (substantially orthogonal in the present embodiment) and are substantially parallel to each other. It consists of That is, a plurality of first grooves 21 and a plurality of second grooves 22 are formed on the outer peripheral surface 301 so as to form a lattice shape. Therefore, a convex portion 23 is formed in a region surrounded by a pair of first grooves 21 adjacent to each other and a pair of second grooves 22 adjacent to each other.

As shown in FIG. 3, the first groove 21 is formed in a spiral shape along the outer peripheral surface 301. In other words, the first groove 21 extends in a direction inclined with respect to the circumferential direction of the outer peripheral surface 301.
Further, as shown in FIG. 4, the first groove 21 has a trapezoidal cross-sectional shape. The configuration of the second groove 22 is the same as the configuration of the first groove 21 except that the extending direction is different as described above. For convenience of explanation, FIG. 4 schematically shows the first groove 21 and the second groove 22.

Since such uneven portions 2 are regular and uniform, it is possible to carry a uniform and optimum amount of toner T on the developing roller 510, and to allow toner to roll on the outer peripheral surface of the developing roller 510 ( (Ease of rolling) can also be made uniform. As a result, it is possible to prevent poor local charging and conveyance of the toner and to exhibit excellent development characteristics.
In addition, unlike those obtained by blasting, the uneven portion 2 has excellent mechanical strength because the width of the tip of the protruded portion 23 is relatively large. In particular, since the concavo-convex portion 2 is obtained by a process such as transfer (rolling) using a mold as will be described later, the strength of the pressed portion is improved and obtained by a process such as cutting. Even when compared to those obtained, it has excellent mechanical strength. The developing roller 510 having such a concavo-convex portion 2 can exhibit excellent durability even when it is slid by the regulating blade 560 and the toner supply roller 550 as described above. Therefore, such a developing roller 510 can be suitably used in a developing device that uses dry one-component non-magnetic toner. In addition, if the width of the tip of the convex portion of the concavo-convex portion 2 is relatively large, there is little change in shape even if it is worn, so that the development characteristics are prevented from abruptly decreasing and excellent development characteristics are exhibited over a long period of time. be able to.

The main body 300 of the developing roller 510 is composed mainly of a metal material such as aluminum, stainless steel, or iron.
The outer peripheral surface (outer peripheral surface 301) of the main body 300 may be subjected to nickel plating, chrome plating, or the like as necessary.
The outer diameter (diameter) of the main body 300 is not particularly limited, but is preferably 10 to 30 mm, for example, and more preferably 15 to 20 mm.

<Method for producing developer carrier>
Next, based on FIGS. 5 to 8, a method for manufacturing the developing roller 510 will be described as an example of a method for manufacturing the developer carrying member of the present invention.
FIG. 5 is a diagram for explaining a method for producing a developer carrier according to an embodiment of the present invention, and FIG. 6 is an outline of an apparatus for forming an uneven portion on the outer peripheral surface of a substrate in the production method shown in FIG. FIG. 7 is a plan view of the apparatus shown in FIG. 6, and FIG. 8 is a diagram for explaining the formation of uneven portions on the outer peripheral surface of the substrate in the manufacturing method shown in FIG. 5.
The manufacturing method of the developing roller 510 includes [1] preparing a cylindrical base material to be the developing roller 510, and [2] forming the concavo-convex portion 2 on the outer peripheral surface of the base material.
Hereinafter, each process will be described in detail.

[1] Step of Preparing Substrate First, as shown in FIG. 5A, a cylindrical substrate 300A to be the developing roller 510 is prepared.
This base material 300A is to be the main body 300 of the developing roller 510 described above, and is composed mainly of a metal material such as aluminum, stainless steel, iron or the like. More specifically, iron-based materials such as STKM, STK, and SGP, and aluminum-based materials such as A6063 and A5056 are preferably used as the constituent material of the base material 300A. Thereby, in the manufacturing process described later, when the uneven portion 2 is formed on the outer peripheral surface 301 of the main body 300 (developing roller 510), the uneven portion 2 can be easily and reliably formed.

Moreover, the outer diameter of this base material 300A is not particularly limited, but is preferably 10 to 30 mm, and more preferably 15 to 25 mm.
Further, the thickness of the base material 300A is not particularly limited, but is preferably 0.2 to 3 mm, and more preferably 0.5 to 3 mm.
As shown in FIG. 5B, the inner peripheral portion at the end portion in the axial direction of the base material 300A is removed by, for example, about 0.5 to 1 mm in thickness by cutting or the like, and the bearing is thinned. A press-fitting portion 302 for press-fitting the shaft member 310 </ b> A to be the portion 310 is formed.

As a result, the dimensional accuracy of the press-fitting portion 302 is excellent, and the shaft member 310A can be easily press-fitted into the base material 300A, and the shaft member 310A can be inserted after the press-fitting without using an adhesive or welding. It can be firmly fixed to the substrate 300A.
Then, as shown in FIG. 5C, the shaft member 310A is press-fitted into the press-fitting portion 302 of the substrate 300A. Thereby, the shaft member 310A is fixed to the base material 300A.

As a method for fixing the shaft member 310A to the base member 300A, the shaft member 310A may be only press-fitted into the press-fitting portion 302 of the base member 300A, or an adhesive or welding may be used.
Thereafter, the outer peripheral surface of the base member 300A and the outer periphery of the protruding portion of the shaft member 310A so that the axis of the base member 300A matches the axis of the portion of the shaft member 310A that protrudes from the end surface of the base member 300A. Grind the surface. Thereby, as shown in FIG.5 (d), the bearing part 310 which protrudes from the both ends of 300 A of base materials is formed.

Although this grinding method is not particularly limited, for example, centerless polishing can be suitably used.
Moreover, in the base material 300A and the bearing portion 310 after grinding, it is preferable that the outer diameter accuracy is ± 10 to ± 50 μm, the deflection is preferably 10 to 50 μm, and the surface roughness is 0. The thickness is preferably 5 to 1 μm. As a result, the dimensional accuracy of the developing roller 510 obtained can be further improved.
The formation of the press-fitting portion 302 and the press-fitting of the shaft member 310A may be performed after step [2] described later. Further, the formation of the press-fit portion 302 and the grinding of the outer peripheral surfaces of the base material 300A and the shaft member 310A can be omitted.

[2] Step of Forming Irregularities Next, as shown in FIG. 5E, the irregularities 2 are formed on the outer peripheral surface of the base material 300A.
Hereinafter, the formation of the uneven portion 2 will be described in detail with reference to FIGS.
In forming the uneven portion 2, for example, a processing apparatus 200 as shown in FIGS. 6 and 7 is used.

  The processing apparatus 200 shown in FIGS. 6 and 7 presses the base 210 that supports the base 300A obtained in the above-described step [1] from below and the base 300A on the base 210 from both sides. It has a first mold 220 and a second mold 230 (a pair of dice).

Each of the first mold 220 and the second mold 230 has a disk shape (short columnar shape) and is rotatable around its axis.
In addition, as shown in FIG. 7, the first mold 220 is formed with a plurality of ridges 221 having a shape corresponding to the shape of the plurality of first grooves 21 to be formed. On the other hand, the second mold 230 is formed with a plurality of ridges 231 having a shape corresponding to the shape of the plurality of second grooves 22 to be formed.

The constituent materials of the first mold 220 and the second mold 230 are not particularly limited, but are preferably harder than the base material 300A. Specifically, SKD, SKH, SLD or the like can be preferably used.
Further, the pitch between the ridges 221 and the pitch between the ridges 231 are not particularly limited, but are preferably 50 to 150 μm, and more preferably 50 to 100 μm.

As described above, the concavo-convex portion 2 is composed of a large number of first grooves 21 formed in parallel to each other, and a large number of second grooves 22 formed in parallel to each other while intersecting the first grooves 21. It is configured. Therefore, regular and uniform uneven portions 2 can be easily formed by using relatively simple shapes as described above as the first mold 220 and the second mold 230.
In addition, since the formation of the first groove 21 and the formation of the second groove 22 are performed using separate molds, it is only necessary to provide a plurality of ridges parallel to each other. It can be simple and the mold can be inexpensive.

  Further, when the pitch between the first grooves 21 and / or between the second grooves 22 is defined as p, p is preferably smaller than the pitch of the resolution used (resolution of the image), and more specifically. For example, p is preferably smaller than 169 μm when the resolution is 150 dpi, and preferably smaller than 127 μm when the resolution is 200 dpi, and the resolution is 300 dpi. In some cases, it is preferably smaller than 85 μm. Thereby, unevenness of the toner image obtained by development can be prevented.

  Further, when the depth of the first groove 21 and / or the second groove 22 is D and the average particle diameter of the toner T (developer) is d, D / d is 0.5 to 2. Is preferable, and it is more preferable that it is 0.9-1.3. Thus, the obtained developing roller 510 can carry the toner T uniformly and in an optimum amount on the uneven portion 2. On the other hand, if D / d is less than the lower limit value, depending on the shape of the concavo-convex portion 2, it is difficult to be caught by the convex portion of the concavo-convex portion 2, the toner rolling property is deteriorated, and charging failure is likely to occur. . On the other hand, if D / d exceeds the upper limit, depending on the shape of the concavo-convex portion 2, the toner in the groove (in the concave portion of the concavo-convex portion 2) does not come in contact with either the developing roller 510 or the regulating blade 560. It may cause charging failure.

  Further, when the width of the first groove 21 and / or the second groove 22 is W and the average particle diameter of the toner T (developer) is d, W / d is preferably 2 to 20. , W / d is more preferably 4-10. Thus, the obtained developing roller 510 can carry the toner T (developer) in a uniform and optimal amount on the uneven portion 2. On the other hand, if W / d is less than the lower limit, depending on the shape of the concavo-convex portion 2, the toner does not enter the groove and the rolling property is deteriorated to cause poor charging, or the toner enters the groove. However, it tends to stay in the groove and cause filming. On the other hand, if W / d exceeds the upper limit, depending on the shape of the concavo-convex portion 2, the amount of toner carried on the developing roller 510 is small, causing poor conveyance, or the toner contacts the convex portion of the concavo-convex portion 2. Opportunities are reduced, rolling properties are deteriorated, and charging failure may occur.

Each of the first mold 220 and the second mold 230 is disposed such that the plate surfaces thereof are slightly inclined with respect to the direction perpendicular to the axis of the base material 300A.
When the first mold 220 and the second mold 230 are rotated in opposite directions while pressing the base 300A from both sides, the base 300A is conveyed in the axial direction as shown by arrows in FIG. However, processing by the first mold 220 and the second mold 230 is performed.

  In forming the first groove 21 of the concavo-convex portion 2 by such processing, the first groove 21 is formed by one press of the convex strip 221 of the first mold 220 against the outer peripheral surface of the base material 300A. However, it is preferable to form the first groove 21 by pressing the convex strip 221 of the first mold 220 against the outer peripheral surface of the base 300A a plurality of times. Thereby, since the outer peripheral surface of the base material 300A is gradually plastically deformed, the residual stress in the processed base material 300A can be reduced, and the mechanical strength of the concavo-convex portion 2 can be made more excellent. Moreover, the uniform uneven | corrugated | grooved part 2 can be formed more reliably.

  Similarly, when forming the second groove 22 of the concavo-convex portion 2, the second groove 22 is formed by one press of the convex strip 231 of the second mold 230 against the outer peripheral surface of the base 300A. However, it is preferable to form the second groove 22 by pressing the convex strips 231 of the second mold 230 a plurality of times against the outer peripheral surface of the substrate 300A. Thereby, since the outer peripheral surface of the base material 300A is gradually plastically deformed, the residual stress in the processed base material 300A can be reduced, and the mechanical strength of the concavo-convex portion 2 can be made more excellent. Moreover, the uniform uneven | corrugated | grooved part 2 can be formed more reliably.

Hereinafter, an example of the formation of the concavo-convex portion 2 by rolling with such multiple pressings will be described more specifically. Since the formation of the first groove 21 and the formation of the second groove 22 are substantially the same, the formation of the first groove 21 will be representatively described. Moreover, in the following description, the case where the uneven | corrugated | grooved part 2 is formed by 3 times press is demonstrated to an example. The number of times the mold is pressed is not limited to this.
First, in the first pressing, as shown in FIG. 8B, the convex strip 221 of the first mold 220 is pressed against the outer peripheral surface of the base material 300A as shown in FIG. Then, the groove 21A having a depth of, for example, about one third of the depth of the first groove 21 to be formed is formed.

Next, in the second pressing, the first strip 220 to be formed is pressed as shown in FIG. 8C by pressing the convex strip 221 of the first mold 220 against the same location as the groove 21A of the base 300A. A groove 21B having a depth of about two thirds of the depth of the groove 21 is formed.
And by pressing the convex strip 221 of the 1st type | mold 220 further against the same location as the groove | channel 21B of 300 A of base materials by the 3rd press, as shown in FIG.8 (d), a 1st groove | channel is shown. 21 is formed.

As described above, when the first groove 21 and the second groove 22 are formed by pressing the mold several times at the same location on the outer peripheral surface of the base material 300A, the uniform uneven portion 2 is more reliably obtained. Can be formed.
At this time, if the same mold is used for each pressing, the cost for the mold can be suppressed, and as a result, the cost of the developing roller 510 obtained can be reduced.

On the other hand, when different molds are used for each pressing, the uneven portion 2 having a desired shape can be formed by appropriately selecting the mold used for each time.
In this case, it is preferable that the molds used at each time have different widths of protrusions for forming the first groove 21 and / or the second groove 22. Thereby, when forming the uneven | corrugated | grooved part 2, the easiness of the process with respect to 300 A of base materials, the durability of a type | mold, etc. can be improved by selecting suitably the type | mold used for each time.

Moreover, it is preferable that the width | variety of the protruding item | line of the type | mold used for the (n + 1) th time is smaller than the width | variety of the protruding item | line of the type | mold used for the nth time (however, n is a natural number of 2 or more). Thereby, the uneven | corrugated | grooved part 2 of a desired shape can be formed, reducing the residual stress which arises in 300 A of base materials more. In addition, the durability of the mold can be improved.
Moreover, it is preferable that the height of the projections of the mold used for the last round or the rounds close thereto is smaller than the depth of the concave portion of the concave-convex portion 2. Thereby, since the concave portion of the mold presses the tip of the convex portion of the concavo-convex portion 2 at the time of pressing in the final round or the like, the tip shape of the convex portion of the obtained concavo-convex portion 2 is adjusted to a desired shape, and the tip The strength of can be improved.

As described above, when changing the width and height of the ridges (convex parts) of the mold by pressing each time, the width and height of the ridges (convex parts) are continuously or intermittently on one mold. May be changed. For example, when the outer diameters of the first mold 220 and the second mold 230 are significantly larger than the outer diameter of the base material 300A, the width and height of the ridges may be changed in the circumferential direction of these molds. .
After forming the concavo-convex portion 2 using the mold as described above, the surface is subjected to plating treatment as necessary. Thereby, the mechanical strength of the uneven | corrugated | grooved part 2 obtained can be made further excellent.

The plating method is not particularly limited, and electroless Ni—P plating, electroplating, hard chrome plating, or the like can be preferably used.
The plating thickness is preferably about 2 to 10 μm.
As described above, the developing roller 510 can be manufactured.
Such a developing roller 510, and a developing device and an image forming apparatus including the developing roller 510 can be excellent in developing characteristics and durability.

  The method for producing a developer carrier, the developer carrier, the developing device, and the image forming apparatus according to the present invention have been described above with reference to the illustrated embodiments. However, the present invention is not limited to this. In addition, each part constituting the developer carrying member, the developing device, and the image forming apparatus can be replaced with any one that can exhibit the same function. Moreover, arbitrary components may be added.

In the above-described embodiment, the developer carrier and the base material for forming the developer carrier have been described as being cylindrical. However, the developer carrier (main body) and the base material may be columnar.
Further, the shape of the concavo-convex portion formed on the outer peripheral surface of the developer carrying member is not limited to that of the above-described embodiment, and is arbitrary as long as it has a function of carrying the developer. For example, in the above-described embodiment, the first groove 21 and the second groove 22 are substantially orthogonal to each other. However, the present invention is not limited to this, and the first groove 21 and the second groove 22 may be formed so as to intersect with an acute angle or an obtuse angle.

  In the above-described embodiment, the first groove 21 and the second groove 22 are formed using different molds. However, the first groove 21 and the second groove 22 are formed in one mold. An uneven pattern may be formed. In this case, for example, the concavo-convex pattern may be formed on the outer peripheral surface of one of the first mold 220 and the second mold 230, and the outer peripheral surface of the other mold may be a flat surface. The concavo-convex pattern may be formed.

In the above-described embodiment, the uneven portion 2 is formed while moving the base material 300A in the axial direction using a disk-like (short columnar) mold, but the uneven portion 2 of the base material 300A. The concavo-convex portion 2 may be formed without moving the base material 300A in the axial direction by using a cylindrical mold having a length substantially the same as the length in the axial direction of the site to be formed.
Moreover, the type | mold used for formation of the uneven | corrugated | grooved part 2 is not limited to a disk shape or cylindrical shape as mentioned above, The thing of other shapes, such as plate shape, may be sufficient.

1 is a schematic cross-sectional view showing a schematic configuration of an image forming apparatus of the present invention. 1 is a schematic cross-sectional view showing a schematic configuration of a developing device of the present invention. FIG. 3 is a plan view showing a schematic configuration of a developer carrier provided in the developing device shown in FIG. 2. It is an expanded sectional view in the AA line in FIG. It is a figure for demonstrating the manufacturing method of the developing agent carrier concerning embodiment of this invention. It is a perspective view which shows schematic structure of the apparatus which forms an uneven | corrugated | grooved part in the outer peripheral surface of a base material in the manufacturing method shown in FIG. It is a top view of the apparatus shown in FIG. It is a figure for demonstrating formation of the uneven | corrugated | grooved part with respect to the outer peripheral surface of a base material in the manufacturing method shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus 2 ... Irregularity part 21 ... 1st groove | channel 21A, 21B ... Groove 22 ... 2nd groove | channel 23 ... Protrusion part 20 ... Photoconductor 30 ... Charging unit 200 ... Processing Device 210 ... Base 220 ... First mold 221 ... Convex strip 230 ... Second mold 231 ... Convex strip 300 ... Main body 300A ... Base material 301 ... Outer peripheral surface 302 ... Press-fit portion 310 …… Bearing part 310A …… Shaft member 40 …… Exposure unit 50 …… Development unit 50a …… Shaft 51 …… Black development device 52 …… Magenta development device 53 …… Cyan development device 54 …… Yellow development device 55 …… Holding body 55a to 55d ...... Holding part 510 ...... Developing roller 520 ... Seal member 530 ...... Housing part 540 ... Housing 550 ... Toner supply roller 560 …… Regulation Blade 560a …… Rubber portion 560b …… Rubber support portion 562 …… Blade support sheet metal 570 …… Blade back member 60 …… Primary transfer roller 61 …… Intermediate transfer member 70 …… Intermediate transfer belt 71 …… Drive roller 72 …… Follower roller 73 ... Substrate 75 ... Cleaning unit 76 ... Cleaning blade 80 ... Secondary transfer roller 82 ... Paper feed tray 84 ... Paper feed roller 86 ... Registration roller 87 ... Paper discharge roller pair 88 ... Conveyance Portion 88A, 88B ... Conveying roller pair 88C ... Conveying path 90 ... Fixing device p ... Pitch P ... Recording medium T ... Toner

Claims (15)

A method for producing a developer carrying body having a cylindrical shape or a columnar shape, and having a concavo-convex portion carrying a developer on its outer peripheral surface,
Preparing a cylindrical or columnar base material to be the developer carrier;
And a step of forming the concavo-convex portion by pressing a mold for forming the concavo-convex portion on the outer peripheral surface of the base material.   2. The uneven portion includes a plurality of first grooves formed in parallel with each other and a plurality of second grooves formed in parallel with each other while intersecting the first grooves. A method for producing a developer bearing member as described in 1. above.   The method for producing a developer carrier according to claim 2, wherein the formation of the first groove and the formation of the second groove are performed using different molds.   4. The developer carrier according to claim 2, wherein the first groove and / or the second groove is formed by pressing the mold several times at the same location on the outer peripheral surface of the base material. Manufacturing method.   The method for producing a developer carrying member according to claim 4, wherein the same mold is used for each pressing.   The method for producing a developer carrying member according to claim 4, wherein different molds are used for each pressing.   The method for manufacturing a developer carrier according to claim 6, wherein the mold used for each round has protrusions for forming the first groove and / or the second groove, and the widths thereof are different from each other.   8. The method for producing a developer carrying member according to claim 7, wherein the width of the ridges of the mold used for the (n + 1) th time is smaller than the width of the ridges of the mold used for the nth time (where n is a natural number of 2 or more. ).   The method for manufacturing a developer carrying member according to any one of claims 6 to 8, wherein the height of the ridge of the mold used in the final round is smaller than the depth of the concave portion of the concave and convex portion.   10. The developer carrying according to claim 2, wherein when the pitch between the first grooves and / or between the second grooves is p, p is smaller than the pitch of the resolution used. Body manufacturing method.   11. The D / d is 0.5 to 2, where D is the depth of the first groove and / or the second groove, and d is the average particle diameter of the developer. A method for producing a developer carrying member according to any one of the above.   12. The W / d is 2 to 20, where W is a width of the first groove and / or the second groove and d is an average particle diameter of the developer. A method for producing a developer bearing member as described in 1. above.   A developer carrying member manufactured using the manufacturing method according to claim 1.   14. A developer carrying body according to claim 13, wherein the developer carrying body is in contact with or in close proximity to a latent image carrying body carrying a latent image, from the developer carrying body to the latent image carrying body. A developing device characterized by visualizing the latent image as a developer image by applying a developer to a body. An image forming apparatus that forms an image on a recording medium by a series of image forming processes including charging, exposure, development, transfer, and fixing,
An image forming apparatus comprising the developing device according to claim 14.

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