JP5097255B2 - Developing roller, developing roller manufacturing method, developing device, and image forming apparatus - Google Patents

Description

The present invention relates to a developing roller , a developing roller manufacturing method, a developing device, and an image forming apparatus.

Image forming devices such as printers, copiers, and facsimile machines that employ electrophotographic methods
An image made of toner is formed on a recording medium such as paper by a series of image forming processes such as a charging step, an exposure step, a development step, a transfer step, and a fixing step.
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.
In addition, there has been a demand for a method that can arbitrarily set the uneven shape of the outer peripheral surface of the developing roller to a desired one.

JP 2003-263018 A

SUMMARY OF THE INVENTION An object of the present invention is to provide a developing roller , a developing roller manufacturing method, a developing device, and an image forming apparatus having improved development characteristics and improved durability.

Such an object is achieved by the present invention described below.
The developing roller of the present invention is a developing roller carrying a developer on its outer peripheral surface ,
The outer peripheral surface has protrusions regularly arranged surrounded by grooves, and the top of the protrusion is formed as a curved convex surface having a smaller radius of curvature than the radius of curvature of the outer peripheral surface. Features.
As a result, the developer can be carried on the top surfaces of the plurality of protrusions. Therefore, the developing roller can carry a uniform and optimum amount of developer on the outer peripheral surface thereof, and the rolling property (ease of rolling) of the developer on the outer peripheral surface of the developing roller is also uniform. can do. As a result, it is possible to prevent local charging failure and conveyance failure of the developer and to exhibit excellent development characteristics.
Furthermore, since the protrusion can be formed relatively large, the durability of the protrusion can be improved.

In the developing roller of the present invention, it is preferable that the width of the groove gradually decreases from the edge of the groove toward the bottom of the groove .
Accordingly, the developer can easily enter and exit, and the rolling property of the developer is improved. As a result, bias of the developer can be prevented, and the developing roller can exhibit excellent development characteristics.

In the developing roller of the present invention, it is preferable that the average curvature radius of the curved convex surface is 5 μm to 50 μm.
Accordingly, the developer can easily enter and exit, and the rolling property of the developer is improved. As a result, bias of the developer can be prevented, and the developing roller can exhibit excellent development characteristics.

In the developing roller of the present invention, it is preferable that the bottom of the groove is curved, and the average curvature radius of the curve is 5 to 200 μm.
Thereby, the developing roller can carry the developer in a uniform and optimum amount in the first groove and / or the second groove .

In the developing roller of the present invention, it is preferable that the groove portions are a first groove formed in parallel to each other and a second groove formed to be parallel to each other while intersecting the first groove.
Thus, the protrusion can be formed only by forming a relatively simple uneven pattern on the outer peripheral surface of the developing roller, and the manufacturing cost of the developing roller can be reduced.

In the developing roller of the present invention, when the pitch between the first grooves and / or between the second grooves is p, it is preferable that p is smaller than the resolution pitch of the image to be formed.
Thereby, unevenness of the toner image obtained by development can be prevented.

In the developing roller of the present invention, when the opening 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 to 20. It is preferable.
Thus, the developing roller 510 can carry the toner T on the uneven portion 2 in a uniform and optimum amount.

Method for producing a developing roller of the present invention is a method of producing a developing roller of the present invention,
Preparing a substrate to be the developing roller ;
Forming the plurality of protrusions by pressing a mold against the outer peripheral surface of the base material.
Thereby, regular and uniform uneven portions can be formed on the outer peripheral surface of the developing roller . Therefore, the obtained developing roller can carry a uniform and optimum amount of developer on its outer peripheral surface, and the developer rolling property (ease of rolling) on the outer peripheral surface of the developing roller is also uniform. Can be. As a result, it is possible to prevent local charging failure and conveyance failure of the developer and to exhibit excellent development characteristics.

The developing device of the present invention includes the developing roller of the present invention, and the developing roller is in contact with or in close proximity to a latent image carrier that carries a latent image, and from the developing roller to the latent image carrier. By applying a developer, the latent image is visualized as a developer image.
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.

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 and BB 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.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a developer carrying body, a developer carrying body manufacturing method, a developing apparatus, and an image forming apparatus according to the present invention will be described below 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, such an image forming apparatus 10 has a photosensitive member 20 that carries an electrostatic latent image and rotates in the direction of an arrow in the figure, and sequentially, along the rotation direction, a charging unit 30, 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 includes a paper feed tray 82 that accommodates a recording medium P such as paper at the bottom in FIG.
The secondary transfer roller 80 and the fixing device 90 are sequentially arranged along the conveyance direction of the recording medium P downstream of the sheet feeding tray 82 in 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 photoreceptor 20 includes a cylindrical conductive substrate (not shown) and a photosensitive layer (on the outer peripheral surface).
(Not shown) and can be rotated around the axis in the direction of the arrow in FIG.
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, the black developing device 51 is black (K
) Toner and magenta developing device 52 uses magenta (M) toner, cyan developing device 53 uses cyan (C) toner, and yellow developing device 54 uses yellow (Y) toner.

The YMCK developing unit 50 in this embodiment includes the above-described four developing devices 51, 52,
53 and 54 are rotatable so as to selectively face the photoconductor 20. Specifically, the YMCK developing unit 50 includes four developing devices 51, 52, 53, and four developing units 51a, 55b, 55c, and 55d, respectively, that are rotatable about a shaft 50a.
54 is held, and the four developing devices 51, 52, 53, 5 are rotated by the rotation of the holding body 55.
4 selectively opposes the photoconductor 20 while maintaining the relative positional relationship. 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, which is stretched by a primary transfer roller 60, a driven roller 72, and a driving roller 71.
Due to the rotation of the drive roller 71, the drive roller 71 is driven to rotate in the direction of the arrow shown in FIG.
The primary transfer roller 60 transfers a single color toner image formed on the photoreceptor 20 to the intermediate transfer belt 70.
It is an apparatus for transferring to the camera.

On the intermediate transfer belt 70, a toner image of at least one of black, magenta, cyan, and yellow is carried. For example, when forming a full-color image, black, magenta,
The four color toner images of cyan and yellow are sequentially superimposed and 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 photoconductor 20 and the developing unit 5
The developing roller (not shown) provided at 0 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 facing portion between the photoconductor 20 and the primary transfer roller 60) as the photoconductor 20 rotates, and the primary transfer roller 6.
With 0, the image is transferred (primary transfer) to the intermediate 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. The conveyance roller pair 88A, 88B is driven, and the recording medium P is conveyed to the conveyance path 88.
The image is reversed through C and returned to the secondary transfer roller 80, and an image is formed on the other surface of the recording medium P by the same operation as described above.

<Developing device>
Next, the developing devices 51, 52, 53, and 54 of the developing unit 50 will be described in detail. In addition,
The developing devices 51, 52, 53, and 54 have the same configuration except for the toner used, and therefore, the yellow developing device 54 will be representatively described below with reference to FIG. 2.
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 carrier, and a toner supply roller 550 that supplies the toner T to the developing roller 510. Toner T carried on developing roller 510
And a regulating blade 560 that regulates the layer thickness.
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. The housing 540 has a regulation blade 560 attached thereto.
This 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 this embodiment, the toner supply roller 55
0 rotates in the direction opposite to the rotation direction of the developing roller 510. The toner supply roller 55
0 has not only a function of supplying the toner T stored in the storage unit 530 to the developing roller 510, but also a function of peeling off the toner T remaining on the developing roller 510 after the development from the developing roller 510. ing.

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 5 as a support member that supports the rubber portion 560a.
60b. 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 this embodiment, a blade back member 570 is provided on the side opposite to the developing roller 510 side of the regulating blade 560, and the toner T is provided between the rubber support portion 560 b 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 the present embodiment, the free end of the regulating blade 560, that is, the blade support sheet metal 562.
The end opposite to the side supported by the roller is not in contact with the developing roller 510 at the edge, but is in contact with the developing roller 510 at a position slightly away from the edge. In addition, the regulation blade 560 is
The tip is arranged so as to face 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.
(A) is an expanded sectional view in the AA line in FIG. 3, FIG.4 (b) is an expanded sectional view in the BB line 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 T (developer) is formed. The uneven portion 2 has a plurality of first grooves 21 that are substantially parallel to each other.
And a plurality of second grooves 22 that intersect (substantially orthogonal to each other in the present embodiment) and are substantially parallel to each other, and a pair of first grooves 21 adjacent to each other. A protrusion 23 is formed by being surrounded by 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. The configuration of the second groove 22 is the same as that of the first groove 2 except that the extending direction is different.
The configuration is the same as that of FIG.

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), more specifically. For example, p is preferably smaller than 169 μm when the resolution is 150 dpi, and is preferably smaller than 127 μm when the resolution is 200 dpi, and the resolution is 300 dpi. Is preferably smaller than 85 μm. Thereby, unevenness of the toner image obtained by development can be prevented.

Further, the depth of the first groove 21 and / or the second groove 22 is D, and toner T (developer)
D / d is preferably 0.5 to 2, where 0.9 to 1.3.
It is more preferable that As a result, the developing roller 510 can carry the toner T uniformly and in an optimum amount in the groove (the first groove 21 and / or the second groove 22). On the other hand, when D / d is less than the lower limit, depending on the shape of the concavo-convex portion 2, the toner is difficult to be caught on the protrusion 23, and the rolling property of the toner is deteriorated, which easily causes a charging failure. On the other hand, if D / d exceeds the upper limit value, depending on the shape of the concavo-convex portion 2, the toner T in the groove may not contact either the developing roller 510 or the regulating blade 560, resulting in a charging failure. .

Further, when the opening width of the first groove 21 and / or the second groove 22 is W and the average particle diameter of the toner T is d, W / d is preferably 2 to 20, and W / d is more preferably 4-10. Thus, the developing roller 510 can carry the toner T on the uneven portion 2 in a uniform and optimum amount. On the other hand, if W / d is less than the lower limit value, depending on the shape of the concavo-convex portion 2, the toner T does not enter the groove and the rolling property is deteriorated to cause charging failure. Even if it enters, 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 or the like, the amount of toner T carried on the developing roller 510 is small, causing a conveyance failure, or the toner T is a protrusion of the concavo-convex portion 2 There are cases where the chance of contact with 23 decreases, the rolling property deteriorates, and charging failure occurs.

As shown in FIGS. 4A and 4B, the width of the first groove 21 and / or the second groove 22 is gradually reduced from the edge 25 toward the bottom. As a result, the toner T can easily enter and exit (move) into the groove.
The cross-sectional shape of the first groove 21 and / or the second groove 22 is not particularly limited as long as the developing roller 510 can carry the toner T. However, the outer shape of the edge continuously changes. It is preferable. As a result, the shape near the top of the protrusion 23 can be a relatively gentle curved surface, and the toner T can easily enter and exit (move) into the groove. As a result, the rolling property of the toner T can be improved, the unevenness of the toner T can be prevented, and the developing roller 510 can exhibit excellent developing characteristics.

Further, the cross-sectional shape of the first groove 21 and / or the second groove 22 is such that the outer shape of the bottom 24 of the first groove 21 and / or the second groove 22 is concave toward the axis of the developing roller 510. It is particularly preferable that the curved shape is as follows. In other words, in the cross section of the first groove 21 and / or the second groove 22, it is particularly preferable that the outer shape of the bottom 24 is substantially U-shaped. Thereby, clogging of the toner T in the groove can be prevented.

Furthermore, it is more preferable that the cross-sectional shape of the first groove 21 and / or the second groove 22 is continuously changed from the bottom 24 toward the edge 25. Thereby, the 1st groove | channel 21 and / or the 2nd groove | channel 22 can be formed from the one edge part 25 to the other edge part 25 with a gentle curved surface. As a result, while preventing the toner T from clogging in the groove, the toner T easily enters and exits (moves) into the groove, prevents the toner T from being biased, and the developing roller 51
0 can exhibit excellent development characteristics.

By adopting the shape of the first groove 21 and / or the second groove 22 as in the present embodiment, in particular, the toner T is prevented from clogging in the groove, and the toner T enters the groove. Easy access. Therefore, the rolling property of the toner T is improved, and the deviation of the toner T in the groove can be prevented. As a result, the developing roller 510 can prevent local charging failure and conveyance failure of the toner T and exhibit excellent development characteristics.

Moreover, the average curvature radius of the curvature of the bottom portion 24 is not particularly limited, but is preferably 5 to 200 μm, and more preferably 30 to 200 μm. Accordingly, clogging of the toner T can be prevented, and the developing roller 510 can carry a uniform and appropriate amount of toner T. On the other hand, when the average radius of curvature of the curvature of the bottom portion 24 exceeds the upper limit value, depending on the shape of the concavo-convex portion 2 or the like, the amount of toner T carried on the developing roller 510 is small, resulting in poor conveyance. There is a case. When the value is less than the lower limit value, depending on the shape of the concavo-convex portion 2, the toner T may stay in the groove and cause filming.
Note that the shape of the bottom of the first groove 21 and / or the second groove 22 is not particularly limited as long as the toner T easily enters and exits in the groove. For example, the bottom 24 has a flat surface. There may be.

In the present embodiment, the plurality of first grooves 21 that are substantially parallel to each other and the plurality of second grooves 22 that intersect the first grooves 21 and are substantially parallel to each other are surrounded by the protrusions. However, the present invention is not limited to this as long as the protrusion 23 can be formed. For example, the protrusion can be formed by forming a third groove in addition to the first groove 21 and the second groove 22. 23 may be formed. Further, the first groove 21 and the second groove 22 may not be linear grooves, and may be meandering or refracting, for example. In addition, the cross-sectional shapes of the first groove 21 and the second groove 22 may change in the longitudinal direction of each of the first groove 21 and the second groove 22.

As shown in FIG. 3, the protruding portion 23 is surrounded by a pair of adjacent grooves among the many first grooves 21 and a pair of adjacent grooves among the many second grooves 22. Is formed. Accordingly, the protrusion can be formed only by forming a relatively simple uneven pattern on the outer peripheral surface of the developer carrier, and the manufacturing cost of the developer carrier can be reduced.

The top surface of the protrusion 23 is a curved convex surface (curved surface that is convex toward the outer edge of the developing roller 510). The curved convex surface is formed by connecting the first grooves 21 adjacent to each other and the second grooves 22 adjacent to each other through a continuously changing surface. As a result, the toner T easily enters and exits the groove, and the rolling property of the toner T is improved. As a result, the unevenness of the toner T can be prevented, and the developing roller 510 can exhibit excellent developing characteristics.
If a curved convex surface can be formed on the top of the protrusion 23, the adjacent first groove 21 is formed.
The configuration between them is not particularly limited. For example, a flat edge may be formed so as to surround the curved convex surface, or a curved convex surface that changes discontinuously may be used.

The average radius of curvature of the curved convex surface is not particularly limited, but is preferably 50 μm or less, and more preferably 5 to 30 μm. Thereby, the rolling property of the toner T can be further improved. As a result, the toner T can easily enter and exit (move) into the groove, the deviation of the toner T in the groove can be prevented, and the developing roller 510 can exhibit excellent development characteristics. On the other hand, when the average radius of curvature of the curved convex surface exceeds the upper limit value, depending on the shape of the protrusion 23, the amount of toner carried on the developing roller 510 is small, and a conveyance failure may occur. Further, when the value is less than the lower limit value, the durability of the tip of the protrusion 23 may be reduced depending on the shape of the protrusion.

In addition, when the degree of curve or curved surface is approximated by a circle, the radius of the circle is the “curvature radius”.
The average value of the radius of curvature at each point of the curve or curved surface is called “average radius of curvature”.
Furthermore, since the top of the protrusion 23 has a curved convex surface, the protrusion 23 can also exhibit excellent durability against contact with the regulating blade 560, the toner supply roller 550, and the like. . Further, since the top of the protrusion 23 has a curved convex surface, it is possible to prevent the regulating blade 560 and the toner supply roller 550 from being inadvertently damaged.

Since the uneven portion 2 is regular and uniform, a uniform and optimum amount of toner T can be carried on the developing roller 510, and the toner rolling property on the outer peripheral surface of the developing roller 510 is possible. (Ease of rolling) can also be made uniform. Further, since the top of the protrusion 23 is a curved convex surface, the toner can easily enter and exit the groove, and the rolling property of the toner is improved. As a result, toner bias, local charging failure, and conveyance failure can be prevented, and the developing roller 510 can exhibit excellent developing characteristics.

Moreover, since such uneven | corrugated | grooved part 2 is obtained by processes, such as transcription | transfer (rolling) using a type | mold so that it may mention later, the intensity | strength of the pressed part improves and it is obtained by blasting etc. 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.
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.
Such a developing roller 510 is manufactured as follows, for example.

<Method for producing developer carrier>
Based on FIGS. 5 to 7, the above-described method for manufacturing the developing roller 510 will be described as an example of the 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 the embodiment of the present invention.
These are the perspective views which show 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. 5, FIG. 7 is a top view of the apparatus shown in FIG.
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 should be the main body 300 of the developing roller 510 described above,
The main material is a metal material such as aluminum, stainless steel or iron. 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, when the uneven part 2 is formed on the outer peripheral surface 301 of the main body 300 (developing roller 510) in the manufacturing process described later, the groove can be formed easily and reliably.

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. Part 31
A press-fitting portion 302 for press-fitting the shaft member 310A to be zero is formed.

Thereby, the dimensional accuracy of the press-fit portion 302 becomes excellent, and the shaft member 310 is attached to the base material 300A.
A can be easily press-fitted, and the shaft member 310A can be firmly fixed to the substrate 300A after the press-fitting without using an adhesive or welding.
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 of fixing the shaft member 310A to the base material 300A, the shaft member 310A is used as the base material 30.
It may be only press-fitted into the 0A press-fitting portion 302, 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.

Further, in the base material 300A and the bearing portion 310 after grinding, the outer diameter accuracy is ± 10 to ± 50.
It is preferable to set it as μm, and it is preferable that the deflection is 10 to 50 μm, and it is preferable that the surface roughness is 0.5 to 1 μm. Thus, the obtained developing roller 510 is obtained.
The dimensional accuracy can be made more excellent.
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 FIG. 6 and FIG. 7 is the base material 300A obtained by process [1] mentioned above.
And a first die 220 and a second die 230 (a pair of dies) for pressing the base material 300A on the base 210 from both sides.
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 (convex portions) 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 23
0 includes a plurality of ridges (convex portions) having a shape corresponding to the shape of the plurality of first grooves 21 to be formed.
231 is formed.
The constituent material of the first mold 220 and the second mold 230 is not particularly limited, but is preferably a material harder than the base material 300A, specifically, SK.
D, SKH, SLD and the like can be preferably used.
Each of the first mold 220 and the second mold 230 has a plate surface of the substrate 300.
It is disposed so as to be slightly inclined with respect to a direction perpendicular to the axis of A.
The uneven part 2 can be formed by pressing the first mold 220 and the second mold 230 against the substrate 300A.

When the first mold 220 and the second mold 230 are pressed in the opposite directions while being pressed against the base material 300A, the base material 300A is conveyed in the axial direction as shown by arrows in FIG.
The mold 220 and the second mold 230 are processed. As a result, the developing roller 510 having the uneven portion 2 as shown in FIG. 4 on the outer peripheral surface is manufactured.
By forming the concavo-convex portion 2 by such pressing, the durability of the protrusion 23 is improved as compared with the case where the concavo-convex portion is formed by blasting.

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.
Such a plating method is not particularly limited, but electroless Ni-P plating,
Electroplating, hard chrome plating, or the like can be suitably 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.

As described above, the developer carrying body, the method for producing the developer carrying body, the developing device, and the image forming apparatus of the present invention have been described with respect 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.
In the above-described embodiment, the first groove 21 and the second groove 22 are substantially orthogonal,
It is not limited to this, You may form so that these may cross | intersect with an acute angle or an obtuse angle.

Further, in the above-described embodiment, the curved convex surface formed on the top of the protrusion 23 has a surface where the first grooves 21 adjacent to each other and the second grooves 22 adjacent to each other continuously change. However, the present invention is not limited to this as long as the toner T can easily enter and exit (move) into the first groove 21 and / or the second groove 22. Only one of the first groove 21 and the second groove 22 may be provided continuously through the continuously changing surface as described above.

In the above-described embodiment, the first groove 21 is the first mold 220 and the second groove 22 is the second.
The molds 230 are formed using different molds, but the first groove 21 and the second groove are formed in one mold.
An uneven pattern for forming the groove 22 may be formed. In this case, for example, the first mold 2
The concavo-convex pattern may be formed on the outer peripheral surface of one of the 20 or the second mold 230 and the outer peripheral surface of the other mold may be a flat surface, or the concavo-convex pattern may be formed on both dies. Good.

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.

DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus 2 ... Irregularity part 21 ... 1st groove | channel 22 ... 2nd groove | channel 23 ...
... Projection 24 ... Bottom 25 ... Edge 20 ... Photoconductor 30 ... Charging unit 20
0 …… Processing device 210 …… Base 220 …… First mold 221 …… Convex ridge 230 …… Second mold 231 …… Convex ridge 300 …… Main body 300A …… Base material 301 …… Outer peripheral surface 30
2 ... Press-fit part 310 ... Bearing part 310A ... Shaft member 40 ... Exposure unit 50 ...
... Developing unit 50a ... Shaft 51 ... Black developing device 52 ... Magenta developing device 53 ... Cyan developing device 54 ... Yellow developing device 55 ... Holding body 55a-55
d …… Holding part 510 …… Developing roller 520 …… Seal member 530 …… Housing part 54
0 …… Housing 550 …… Toner supply roller 560 …… Regulating blade 560a…
... Rubber part 560b ... Rubber support part 562 ... Blade support sheet metal 570 ... Blade back member 60 ... Primary transfer roller 61 ... Intermediate transfer body 70 ... Intermediate transfer belt 71
…… Drive roller 72 …… Following roller 73 …… Substrate 75 …… Cleaning unit
76 …… Cleaning blade 80 …… Secondary transfer roller 87 …… Discharge roller pair 88
...... Conveying unit 88A, 88B ... Conveying roller pair 88C ... Conveying path 82 ... Feeding tray 84 ... Feeding roller 86 ... Registration roller 90 ... Fixing device p ... Pitch P ...
Recording medium T: Toner (developer).

Claims (10)

A developing roller carrying a developer on an outer peripheral surface ,
The outer peripheral surface has protrusions regularly arranged surrounded by grooves, and the top of the protrusion is formed as a curved convex surface having a smaller radius of curvature than the radius of curvature of the outer peripheral surface. A developing roller . The developing roller according to claim 1, wherein the width of the groove gradually decreases from an edge of the groove toward a bottom of the groove. The mean curvature of the curved convex surface radius, the developing roller according to claim 1 or 2 which is 5 m to 50 m. Bottom of the groove, is curved, the average radius of curvature of the curvature, the developing roller according to a any one of claims 1 to 3 is 5 to 200 [mu] m. The groove comprises a first groove that will be parallel to each other, wherein while crossing the groove of the first, to any one of claims 1 to 4 which is a second groove that will be parallel to each other Development roller . The developing roller according to claim 5, wherein when the pitch between the first grooves and / or between the second grooves is p, p is smaller than a resolution pitch of an image to be formed. 6. The development according to claim 5, wherein W / d is 2 to 20, where W is an opening width of the first groove and / or the second groove, and d is an average particle diameter of the developer. roller. A method for producing the developing roller according to any one of claims 1 to 7 ,
Preparing a substrate to be the developing roller ;
By pressing the mold on the outer circumferential surface of the base material, method for producing a developing roller, characterized by comprising the step of forming the protrusions. A developing roller according to any one of claims 1 to 7, the developing roller is opposed in contact with or in proximity to the latent image bearing member for bearing a latent image, the latent image bearing member from the developing roller A developing device characterized in that the latent image is visualized as a developer image by applying a developer. 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 9 .

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