JP2004037663A - Developing roller and developing device having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing roller which prevents ununiform image density which is caused by ununiform amount of attached toner which results from interference fringe due to an interference phenomenon with respect to an image pattern, and also prevents ununiform image density which is caused by an ununiform amount of attached toner which results from large surface roughness and waviness, and to provide a developing device having the developing roller. <P>SOLUTION: In the developing roller 10 having a surface layer 2 made of a resin, which is formed on the surface of a conductive cylindrical substrate 1, the surface of the cylindrical substrate 1 is subjected to cutting work so that the lengths of radii are the same in its circumferential direction. A pitch between a recess and a projection in the axial direction of the cylindrical substrate 1 obtained by the cutting work is 0.06 mm or less. The waviness Wca of the cylindrical substrate is preferably 0.1μm. The ten-point average roughness Rz of the surface of the surface layer is preferably 4 μm or less. The waviness Wca of the cylindrical substrate is preferably 0.5μm or less. <P>COPYRIGHT: (C)2004,JPO

Description

【００３５】
【発明の効果】
（１）請求項１に記載された本発明によれば、円筒状基体が、周方向に沿って半径方向の長さを一定にするように、切削加工により表面仕上げされたものであって、該切削加工による該円筒状基体の軸方向の凹凸ピッチが、０．０６ｍｍ未満であるものとしたので、画像パターンとの干渉現象による干渉縞に起因するトナー付着量のムラにより画像濃度ムラが発生することを防止することができる。
【００３６】
（２）請求項２に記載された本発明によれば、円筒状基体のうねりＷｃａが０．１μｍ以下であるので、切削ピッチの干渉と同様に、画像パターンとの干渉現象による干渉縞に起因するトナー付着量のムラにより画像濃度ムラが発生することを防止することができる。
【００３７】
（３）請求項３に記載された本発明によれば、表面層の表面の十点平均粗さＲｚ　が、４μｍ以下であり、そして、円筒状基体のうねりＷｃａが、０．５μｍ以下であるので、トナー付着ムラを防止することができ、そのために、画像濃度ムラを防止することができる。
【００３８】
（４）請求項４に記載された本発明によれば、表面層の膜厚が、円筒状基体の表面粗さＲｍａｘ　より厚く、且つ、１０μｍ以下であるので、円筒状基体の表面の凹凸が表面層から露出するのを防止することができる。
【００３９】
（５）請求項５に記載された本発明によれば、円筒状基体が金属で構成されているので、表面層を形成する際の焼成温度（１５０〜２００℃）において変形することがないこと、軸より電圧を印加することが可能であること、切削性が良好のために生産性が良好であること、機械的強度（剛性）が高いこと、等の利点がある。
【００４０】
（６）請求項６に記載された本発明によれば、現像ローラと、該現像ローラに接触するように配置されてトナーを該現像ローラに供給するトナー供給ローラと、該現像ローラ上に付着したトナーを規制して薄層を形成するトナー規制部材と、を有する現像装置において、該現像ローラとして、前記請求項１〜５のいずれかに記載の現像ローラを有しているので、画像パターンとの干渉現象による干渉縞に起因するトナー付着量のムラにより画像濃度ムラが発生することを防止すると共に、大きな表面粗さ及びうねりに起因するトナー付着量のムラにより画像濃度ムラを防止ことができる。
【００４１】
（７）請求項７に記載された本発明によれば、トナー規制部材がトナー規制ローラであるので、従来の現像装置で経時で発生していたようなトナー規制ブレードへのトナーフィルミング、及び、トナー規制ブレードと現像ローラとのくさび部へのトナー堆積による現像ローラにおけるトナー薄層上のスジの発生が無くなり、現像装置としての寿命を延ばすことが可能となる。
【図面の簡単な説明】
【図１】本発明の一実施の形態を示す現像ローラの断面図である。
【図２】円筒状基体の表面に切削加工を施す状態を示す説明図である。
【図３】円筒状基体の表面に形成された凹凸ピッチ（研削ピッチ）の拡大断面説明図である。
【図４】本発明の一実施の形態を示す現像装置の概略説明図である。
【図５】従来の現像装置の概略説明図である。
【図６】干渉縞のパターンを示す。
【図７】他の干渉縞のパターンを示す。
【符号の説明】
１　円筒状基体
２　表面層
１０　現像ローラ
１１　トナー供給ローラ
１２　　トナー撹拌・搬送部材
１３　トナー規制ローラ
１４　　バネ
１５　　ケース
１６　　トナー[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a developing roller used in an electrophotographic apparatus such as a copying machine, a printer, and a facsimile, and a developing device having the same.
[0002]
[Prior art]
In recent years, in colorization, a system using a belt photoreceptor has been adopted due to a degree of freedom in layout, and a developing roller having a configuration in which the surface of a hard roller is coated has been adopted. The cylindrical body of such a developing roller is formed by grinding a cylindrical body made of metal, or is formed by cutting a cylindrical body made of metal. In many cases, it is formed by cutting from the viewpoints of processing cost and resin coating performed later.
[0003]
[Problems to be solved by the invention]
However, since the cutting process has regularity in the feed pitch of the cutting tool, when developing the latent image on the electrostatic latent image carrier with the developing roller formed by such cutting process, depending on the pattern of the latent image, An interference phenomenon between the surface shape of the base and the latent image caused by cutting during the processing of the base occurs, and as a result, unevenness in image density due to unevenness in toner adhesion amount due to interference fringes as shown in FIG. There was a problem that occurred. In addition, fringes due to the phenomenon of interference with the latent image also occur due to “undulations” that have irregularities smaller than the large pitch shape such as the cutting feed pitch existing on the surface of the cylindrical substrate, and as a result, the image As described above, there is a problem that image density unevenness occurs due to uneven toner adhesion amount due to interference fringes as shown in FIG. Furthermore, when the surface roughness and waviness of the surface layer formed by the resin coating are large, unevenness in the amount of toner adhesion occurs, so that image density unevenness different from that caused by the interference fringes occurs. was there.
[0004]
The image in which interference fringes occur is a so-called halftone image, which is an image formed by 2 × 2 dots. In the graphic image, the number of lines is changed according to the image quality (high image quality, speed priority). For example, the number of lines such as 106, 134, 150, 168 lines... Is used. However, the "number of lines" is the number of lines per inch, and the higher the number of lines, the better the image quality. Of these lines, interference fringes were observed due to the pitch of the unevenness (cutting pitch) of the developing roller in a halftone image of 150 lines of 2 × 2 at 600 dpi.
[0005]
The present invention aims to solve such a problem.
That is, the present invention prevents image density unevenness from occurring due to uneven toner adhesion caused by interference fringes caused by an interference phenomenon with an image turn, and also reduces uneven toner adhesion caused by large surface roughness and waviness. It is an object of the present invention to provide a developing roller which prevents image density unevenness and a developing device having the same.
[0006]
[Means for Solving the Problems]
The present inventors, in a developing roller having a surface layer made of a resin on the surface of a conductive cylindrical substrate, the cylindrical substrate, so that the radial length along the circumferential direction is constant. Surface finishing is performed by cutting, and in this case, when the pitch of the unevenness in the axial direction of the cylindrical substrate is set to less than 0.06 mm by the cutting, it is found that image density unevenness due to interference fringes can be prevented. The present invention has been completed.
[0007]
That is, in order to achieve the above object, the invention described in claim 1 provides a developing roller having a surface layer made of a resin on the surface of a conductive cylindrical substrate, wherein the cylindrical substrate has a circumferential direction. The surface is finished by cutting so as to keep the length in the radial direction constant along the axis, and the pitch of the concave and convex in the axial direction of the cylindrical substrate by the cutting is less than 0.06 mm. Developing roller characterized by the following.
[0008]
According to a second aspect of the present invention, in the first aspect of the present invention, the undulation Wca of the cylindrical substrate is 0.1 μm or less.
[0009]
The invention described in claim 3 is the invention according to claim 1 or 2, wherein the ten-point average roughness Rz of the surface of the surface layer is 4 μm or less, and the undulation Wca of the cylindrical substrate is The thickness is 0.5 μm or less.
[0010]
The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the film thickness of the surface layer is larger than the surface roughness Rmax of the cylindrical substrate, and is 10 μm or less. It is characterized by having.
[0011]
According to a fifth aspect of the present invention, in the first aspect of the present invention, the cylindrical substrate is made of a metal.
[0012]
The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the developing roller and a toner supply arranged to be in contact with the developing roller to supply toner to the developing roller A developing roller according to any one of claims 1 to 5, wherein the developing roller includes a roller and a toner regulating member that regulates toner attached to the developing roller to form a thin layer. Is a developing device.
[0013]
The invention described in claim 7 is the invention described in claim 6, wherein the toner regulating member is a toner regulating roller.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view of a developing roller according to an embodiment of the present invention. FIG. 2 is an explanatory diagram showing a state in which a cutting process is performed on the surface of the cylindrical substrate. FIG. 3 is an enlarged cross-sectional explanatory view of a pitch of irregularities (grinding pitch) formed on the surface of the cylindrical substrate. FIG. 4 is a schematic explanatory diagram of a developing device showing one embodiment of the present invention. FIG. 5 is a schematic explanatory view of a conventional developing device. FIG. 6 shows a pattern of interference fringes. FIG. 7 shows another interference fringe pattern.
[0015]
In FIG. 1, reference numeral 10 denotes a developing roller. The developing roller 10 has a surface layer 2 made of a synthetic resin on the surface of a conductive cylindrical base 1. The cylindrical substrate 1 is surface-finished by cutting so that the length in the radial direction is constant along the circumferential direction, and the cylindrical substrate 1 is cut in the axial direction by the cutting. The uneven pitch is less than 0.06 mm.
[0016]
When the electrostatic latent image carrier uses a belt substrate, the cylindrical substrate 1 may be an elastic cylindrical substrate, but the surface layer 2 is restricted (for example, flexibility is required). It is easier to use the hard cylindrical substrate 1 because it is not affected. In the case of the hard cylindrical substrate 1, a hard plastic may be used. However, since a bias voltage is applied to the developing roller 10, the cylindrical substrate 1 needs to be a conductor. It is preferable to configure. Further, when the cylindrical substrate 1 is made of a metal, it does not deform at the firing temperature (150 to 200 ° C.) when the surface layer 2 is formed, and a voltage can be applied from the axis. There are advantages such as good productivity, good productivity due to good machinability, and high mechanical strength (rigidity).
[0017]
Shafts are press-fitted into both ends of a cylindrical body, that is, a three-arrow pipe formed by extruding aluminum, to form a cylindrical base 1, and then, as shown in FIG. The surface is finished by cutting the outer diameter with a diamond tool so as to keep the length constant. At that time, the cutting pitch in the axial direction of the cylindrical substrate 1 by the cutting process is set to less than 0.06 mm. The “cutting pitch” in the present invention means between the arrows shown in FIG. 3, that is, between the valleys of the sectional curve. As described above, when the cylindrical substrate 1 is cut, the processing time can be reduced as compared with the case where the cylindrical substrate 1 is ground, and the surface layer 2 having a uniform thickness can be easily formed on the surface thereof. In addition, the formed surface layer 2 is hardly peeled off. Thus, the surface of the cylindrical substrate 1 formed by the cutting process has a regular pitch of irregularities of less than 0.06 mm as shown in FIGS.
[0018]
In the present invention, the cylindrical substrate 1 is surface-finished by cutting so that the length in the radial direction is constant along the circumferential direction, and the cylindrical substrate 1 is formed by the cutting. Since the uneven pitch in the axial direction of the substrate is less than 0.06 mm, it is possible to prevent image density unevenness from occurring due to uneven toner adhesion due to interference fringes due to interference with the image pattern. Can be.
[0019]
In the present invention, the undulation Wca of the cylindrical substrate 1 is set to 0.1 μm or less. When the undulation Wca on the cylindrical substrate 1 exceeds 0.1 μm, an interference phenomenon occurs as in the case of the interference phenomenon caused by the cutting pitch, and interference fringes occur in an image. However, in the present invention, since the waviness Wca of the cylindrical substrate 1 is set to 0.1 μm or less, similar to the interference of the cutting pitch, image unevenness due to interference fringe caused by interference fringes due to the phenomenon of interference with the image pattern. The occurrence of density unevenness can be prevented.
[0020]
In the developing device, a negatively charged toner is usually used. Therefore, it is preferable to use a positively charged resin as the resin constituting the surface layer 2 of the developing roller 10 in order to negatively charge the toner. Therefore, it is effective to use a resin having a nitrogen atom-containing group, which is a resin having a positive charge, as the resin constituting the surface layer 2 of the developing roller 10. The resin constituting the surface layer 2 is preferably a cross-linking reaction product obtained by curing a resin having a hydroxyl group in a molecule with a triazine-based resin (a derivative such as melamine or guanamine). When the surface layer 2 is composed of such a cross-linking reaction product, the toner chargeability of the surface layer 2 can be improved, and the mechanical properties such as water resistance, solvent resistance, and abrasion resistance of the surface layer 2 can be improved. Can also be improved. The resin constituting the surface layer 2 is merely a preferred example, and other resins may be used as long as the object of the present invention is not contravened.
[0021]
In the present invention, the ten-point average roughness Rz of the surface of the surface layer 2 is 4 μm or less, and the undulation Wca of the cylindrical substrate 1 is 0.5 μm or less. When the ten-point average roughness Rz of the surface of the surface layer 2 exceeds 4 μm and the undulation Wca exceeds 0.5 μm, the density unevenness of dots on an image becomes more conspicuous. However, in the present invention, the ten-point average roughness Rz of the surface of the surface layer 2 is 4 μm or less, and the undulation Wca of the cylindrical substrate 1 is 0.5 μm or less, so that uneven toner adhesion is prevented. Therefore, image density unevenness can be prevented.
[0022]
In the present invention, the thickness of the surface layer 2 is greater than the surface roughness Rmax of the cylindrical substrate 1 and is 10 μm or less. In order to satisfy that the ten-point average roughness Rz of the surface of the surface layer 2 of the developing roller 10 is 4 μm or less and the undulation Wca is 0.5 μm or less, the thickness of the surface layer is set to 10 μm or less. Can be achieved. As described above, in the present invention, since the thickness of the surface layer 2 is larger than the surface roughness Rmax of the cylindrical substrate 1 and equal to or less than 10 μm, the unevenness of the surface of the cylindrical substrate 1 Exposure can be prevented.
[0023]
As shown in FIG. 4, the developing device of the present invention includes a developing roller 10, a toner supply roller 11 that is disposed so as to be in contact with the developing roller 10, and supplies a toner 16 to the developing roller 10. 6. A developing device comprising: a toner regulating member (13) for regulating a toner 16 attached to the developing roller 10 to form a thin layer, wherein the developing roller 10 is used as the developing roller 10. Of the developing roller. The toner regulating member is preferably a toner regulating roller. In FIG. 4, 12, 14, and 15 are a toner stirring / conveying member, a spring, and a case, respectively. As described above, since the developing device of the present invention includes the developing roller 10 according to any one of claims 1 to 5 as a developing roller, the toner caused by interference fringes due to an interference phenomenon with an image pattern. It is possible to prevent image density unevenness from occurring due to unevenness in the amount of adhesion, and to prevent unevenness in image density due to unevenness in the amount of toner adhesion due to large surface roughness and waviness.
[0024]
A conventional developing device is, for example, the one shown in FIG. In FIG. 5, reference numeral 20 denotes a developing roller, 21 denotes a toner supply roller, 22 denotes a toner stirring / conveying member, 23 denotes a toner regulating blade, 25 denotes a case, and 26 denotes toner. In the developing device of the present invention, the toner regulating roller 13 does not rotate the driving roller, but rotates the developing roller 10 in a direction opposite to the rotation during the image formation during non-development. As a result, an effect is produced in which the toner 16 deposited on the wedge portion between the developing roller 10 and the toner regulating roller 13 is once pushed back to the upstream side during non-development. Therefore, the contact surface between the toner regulating roller 13 and the developing roller 10 is constantly changing, and the toner filming to the toner regulating blade 23 and the toner regulating blade 23, which have occurred with time in the conventional developing device, occur. The generation of streaks on the thin toner layer in the developing roller 20 due to the accumulation of toner on the wedge portion with the developing roller 20 is eliminated, and the life of the developing device can be extended.
[0025]
In the developing device of the present invention, the driving rotation of the toner regulating roller 13 together with the developing roller 10 is not particularly limited as long as a problem does not occur in the developing device. Explaining the case where the toner regulating roller 13 is not constantly rotated, a one-way clutch (not shown) is provided on the shaft of the toner regulating roller 13 so that the toner regulating roller 13 operates only when the developing roller 10 rotates in the reverse direction. The toner regulating roller 13 can be rotated only by the frictional resistance between the toner regulating roller 13 and the surface of the developing roller 10. The same effect can be obtained by a system in which the toner regulating roller 13 is forcibly driven in the same direction, but the device becomes complicated and side effects such as banding occur depending on the gear configuration. There is a need. The toner 16 supplied to the toner supply roller 11 by the toner agitating / conveying member 12 is supplied to the surface of the developing roller 10 and imparts triboelectric charge to the toner 16 with the toner regulating roller 13. Is adjusted so that the amount of toner on the surface of the surface becomes an appropriate amount. The latent image formed on the electrostatic latent image carrier (not shown) is developed by the charged toner 16.
[0026]
【Example】
(Example 1)
The outer diameter of a Mitsuya pipe made of aluminum with shafts press-fitted at both ends was cut with a diamond bite so that the concave-convex pitch (cutting pitch) became 0.055 mm, thereby forming a cylindrical substrate having a diameter of 26 mm. The undulation Wca of the surface of the cylindrical substrate thus formed was measured by using a measuring machine (Kosaka Laboratories, Surfcoder SE30H) under the following measurement conditions: (1) vertical magnification: 2000 times, (2) ▼ Horizontal magnification: 2.5 times, ③ Measurement length: 25 mm, ４ Measurement speed: 2.0 mm / sec, and ５ Cut-off: fh 0.8 mm, fl 2.5 mm. When measured under the conditions, it was 0.071 μm. On the surface of the cylindrical substrate, a paint containing 70 parts by weight of a polyester resin having a hydroxyl group, 30 parts by weight of a trimethoxymethylmelamine resin, and 54 parts by weight of ITO conductive particles based on alumina powder was spray-coated. Was fired at 160 ° C. for 1 hour to form a developing roller having a surface layer having a thickness of 8 μm. Then, the surface of the developing roller was polished to a thickness of about 0.05 μm using a # 1000 polishing tape (polishing agent: SC) to form a developing roller.
[0027]
(Example 2)
A developing roller was formed in the same manner as in Example 1 except that the outer diameter of the Mitsuya pipe was cut with a diamond bite so that the pitch (cutting pitch) was 0.057 mm.
[0028]
(Example 3)
A developing roller was formed in the same manner as in Example 1 except that the outer diameter of the Mitsuya pipe was cut with a diamond bite so that the pitch of the concavo-convex (cutting pitch) was 0.059 mm.
[0029]
(Comparative Example 1)
A developing roller was formed in the same manner as in Example 1, except that the outer diameter of the Mitsuya pipe was cut with a diamond bite so that the uneven pitch (cutting pitch) became 0.060 mm.
[0030]
(Comparative Example 2)
A developing roller was formed in the same manner as in Example 1, except that the outer diameter of the Mitsuya pipe was cut with a diamond bite so that the uneven pitch (cutting pitch) was 0.063 mm.
[0031]
(Comparative Example 3)
A developing roller was formed in the same manner as in Example 1 except that the outer diameter of the Mitsuya pipe was cut with a diamond bite so that the pitch of concavo-convex (cutting pitch) was 0.065 mm.
[0032]
(Comparative Example 4)
A developing roller was formed in the same manner as in Example 1 except that the outer diameter of the Mitsuya pipe was cut with a diamond bite so that the uneven pitch (cutting pitch) became 0.180 mm.
[0033]
In Examples 2 to 4 and Comparative Examples 1 to 4, the waviness Wca of the surface of the cylindrical substrate was measured in the same manner as described in Example 1. Then, the ten-point average roughness Rz of the surface of the surface layer of the developing roller obtained in Examples 1 to 3 and Comparative Examples 1 to 4 was measured. The “ten-point average roughness Rz” was measured using the measuring device described in the above Example 1 (Kosaka Laboratories, Surfcoder SE30H) under the following measurement conditions: (1) longitudinal magnification: 200 times; (2) Lateral magnification: 20 times, (3) Measurement length: 2.5 mm, (4) Measurement speed: 0.5 mm / sec, and (5) Cutoff: λc 0.8 μm. did. In addition, the undulation Wca of the surface of the surface layer of the developing roller obtained in Examples 1 to 3 and Comparative Examples 1 to 4 was measured. The “undulation Wca on the surface of the surface layer” was measured by the same measurement method as described in Example 1. Further, the developing rollers obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were attached to the developing device shown in FIG. 4 to output 600 dpi, 2 × 2 images, and 150 lines of images. The occurrence of stripes and the presence or absence of image density unevenness were examined. The measurement results are shown in Table 1 below.
[0034]
[Table 1]

[0035]
【The invention's effect】
(1) According to the present invention described in claim 1, the cylindrical substrate is surface-finished by cutting so that the length in the radial direction is constant along the circumferential direction, Since the pitch of unevenness in the axial direction of the cylindrical substrate due to the cutting process is less than 0.06 mm, image density unevenness occurs due to unevenness of toner adhesion amount caused by interference fringes due to an interference phenomenon with an image pattern. Can be prevented.
[0036]
(2) According to the second aspect of the present invention, since the waviness Wca of the cylindrical substrate is 0.1 μm or less, the undulation Wca is caused by interference fringes due to the phenomenon of interference with the image pattern as well as the interference of the cutting pitch. It is possible to prevent image density unevenness from occurring due to uneven toner adhesion amount.
[0037]
(3) According to the third aspect of the present invention, the ten-point average roughness Rz of the surface of the surface layer is 4 μm or less, and the undulation Wca of the cylindrical substrate is 0.5 μm or less. As a result, it is possible to prevent toner adhesion unevenness, and therefore, it is possible to prevent image density unevenness.
[0038]
(4) According to the present invention described in claim 4, since the thickness of the surface layer is greater than the surface roughness Rmax of the cylindrical substrate and is 10 μm or less, the unevenness of the surface of the cylindrical substrate is reduced. Exposure from the surface layer can be prevented.
[0039]
(5) According to the present invention, since the cylindrical substrate is made of metal, it does not deform at the firing temperature (150 to 200 ° C.) when forming the surface layer. There are advantages such as being able to apply a voltage from the shaft, good productivity due to good machinability, and high mechanical strength (rigidity).
[0040]
(6) According to the present invention, a developing roller, a toner supply roller arranged to be in contact with the developing roller and supplying toner to the developing roller, and an adhesion on the developing roller And a toner regulating member that regulates the formed toner to form a thin layer, since the developing roller according to claim 1 is used as the developing roller. This prevents uneven image density due to uneven toner adhesion due to interference fringes caused by interference fringes, and prevents uneven image density due to uneven toner adhesion due to large surface roughness and waviness. it can.
[0041]
(7) According to the present invention, since the toner regulating member is a toner regulating roller, toner filming on the toner regulating blade, which has occurred with time in a conventional developing device, and In addition, generation of streaks on the thin toner layer of the developing roller due to accumulation of toner on the wedge portion between the toner regulating blade and the developing roller is eliminated, and the life of the developing device can be extended.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a developing roller according to an embodiment of the present invention.
FIG. 2 is an explanatory view showing a state where a cutting process is performed on the surface of a cylindrical substrate.
FIG. 3 is an enlarged sectional explanatory view of an uneven pitch (grinding pitch) formed on the surface of a cylindrical substrate.
FIG. 4 is a schematic explanatory diagram of a developing device showing one embodiment of the present invention.
FIG. 5 is a schematic explanatory view of a conventional developing device.
FIG. 6 shows a pattern of interference fringes.
FIG. 7 shows another interference fringe pattern.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cylindrical substrate 2 Surface layer 10 Developing roller 11 Toner supply roller 12 Toner stirring / conveying member 13 Toner regulating roller 14 Spring 15 Case 16 Toner

Claims (7)

In a developing roller having a surface layer composed of a resin on the surface of a conductive cylindrical substrate, the cylindrical substrate is surface-finished by cutting such that the length in the radial direction is constant along the circumferential direction. A developing roller, wherein the pitch of the concavo-convex in the axial direction of the cylindrical substrate by the cutting is less than 0.06 mm. 2. The developing roller according to claim 1, wherein the waviness Wca of the cylindrical substrate is 0.1 μm or less. 3. The developing roller according to claim 1, wherein a ten-point average roughness Rz of the surface of the surface layer is 4 μm or less, and waviness Wca of the cylindrical substrate is 0.5 μm or less. 4. The developing roller according to any one of claims 1 to 3, wherein a thickness of the surface layer is greater than a surface roughness Rmax of the cylindrical substrate and is 10 µm or less. The developing roller according to claim 1, wherein the cylindrical substrate is made of a metal. A developing roller, a toner supply roller disposed so as to be in contact with the developing roller and supplying toner to the developing roller, a toner regulating member that regulates toner attached to the developing roller to form a thin layer, A developing device comprising: the developing roller according to claim 1 as the developing roller. 7. The developing device according to claim 6, wherein the toner regulating member is a toner regulating roller.

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