JP2007057910A - Developer quantity regulating blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer quantity regulating blade for suppressing image irregularity, image stripe, ghost and the like caused by high speed rotation of a development carrier in a developing device accompanying a higher speed of an electrophotographic process by forming a uniform thin layer of a developer on a developing roller to give prescribed triboelectricity to the developer. <P>SOLUTION: The developer quantity regulating blade comprises a roller shaped developer carrier conveying the developer from a developer container of an electrophotographic device toward a developing part, a blade member contact-pressed on the developer carrier, and a support member for supporting the blade member. The developer quantity regulating blade in the developing device makes the developer a uniform thin layer while friction-electrifying the developer between the blade member and the development carrier and develops to supply the developer on the uniform thin layer to an electrostatic latent image formed on a latent image carrier. The blade member has ten-point average roughness (Rz) of 2-25 μm on a part contacted on at least a developer carrier, and has a roughness surface having an irregular average interval (Sm) of 1-400 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a developer amount regulating blade provided in a developing device in an image forming process of an electrophotographic apparatus such as an electrophotographic copying machine, a laser beam printer, and a facsimile machine.

  Conventionally, as a developing device in an image forming process of an electrophotographic apparatus such as an electrophotographic copying machine, a laser beam printer, a facsimile, etc., a part of the developing device is provided in an opening of a developer container for storing developer (toner). A roller-shaped developer carrying member and a developer amount regulating blade provided with a blade member formed of a rubber material that comes into contact with the surface of the developer carrying member are widely used. In such a developing device, the developer carrying member carrying the developer on the surface rotates, and the developer is carried out to the surface of the electrophotographic photosensitive member that contacts and rotates at a portion exposed from the developer container. It is like that. At this time, when the developer passes between the developer carrying member and the blade member, the surplus portion is removed from the surface of the developer carrying member and returned to the developer container. A triboelectric charge (also referred to as tribo) having a polarity opposite to that of the electrostatic latent image formed on the surface of the photographic photosensitive member is applied, and a certain amount thereof is deposited on the surface of the developer carrier. Then, at the contact portion between the developer carrying member and the electrophotographic photosensitive member, the developer is electrostatically attracted to the electrostatic latent image and moved from the surface of the developer carrying member to the surface of the electrophotographic photosensitive member. The image is developed.

  Such a developer amount regulating blade is composed of the developer carrier, a blade member in contact with the surface of the developer carrier, and a support member that supports the developer member in a predetermined position. For example, a blade member made of a plate material such as urethane resin or polyamide elastomer is attached to a support member such as a metal plate. For a positive developer, a blade member made of a plate material such as silicon rubber is used. Is attached to a support member such as a metal plate. The surface of the blade member that is in contact with or pressed against the developer carrying member has a function of controlling the triboelectric charge of the developer and is sometimes called a charge control surface.

  In recent years, in the electrophotographic process, higher image quality and higher speed have been advanced, and in the developing device, the rotation speed of the developing roller has been increased, and accordingly, image unevenness, image streaks, and ghost are suppressed. Technology is being developed.

  Specifically, by setting the ten-point average roughness (Rz) and maximum height (Rmax) of the developer regulating member within a specific range, a stable developer thin layer can be formed, and the image density can be reduced. It has been reported that a stable and high-quality image can be obtained (Patent Document 1). However, in order to form a developer thin layer stably without generation of development streaks, the relationship between the surface roughness of the roughened surface and its fineness is important. In the developer regulating member described in Patent Document 1, only the ten-point average roughness (Rz) and the maximum height (Ry) are in a specific range, and the fineness of the surface is not clear. There is.

In addition, the toner regulating member is roughened so that at least the charge imparting surface has a surface roughness Rz of 1 μm or more and 20 μm or less. It is reported that a high-quality image can be obtained (Patent Document 2). However, it is difficult to form a uniform thin layer of the developer on the surface of the development carrier only by setting the surface roughness (Rz) of the charge imparting surface within a specific range. In the apparatus, developer streaks may occur on the development carrier, and development streaks may occur in image evaluation.
JP 2004-012542 A JP 2004-117919 A

  According to the present invention, as the electrophotographic process increases in speed, image unevenness, image streaks, ghosts, and the like that are generated due to the high-speed rotation of the developer carrier in the developing device are uniformly thinned on the developer carrier. An object of the present invention is to provide a developer amount regulating blade that can be suppressed by forming a layer and applying predetermined tribo to the developer.

  The inventors have studied the surface of a blade member that controls the amount of developer, which causes image unevenness, image streaks, and ghosts accompanying high-speed rotation of the developer carrying member. Conventionally, in order to uniformly charge and transport developer particles, it has been thought that the better the charge control surface of the blade member, the better. However, in recent years, when the effect of the flatness of the charge control surface on the uniform charging and transport of the developer has been studied in detail, in order to achieve uniform charging and unloading of the developer particles, the charge control surface is: It has been clarified that it is sufficient if the surface is smooth to some extent, and that the surface with a roughened charge control surface can realize uniform charging and unloading of the developer and can suppress image defects such as streaks and unevenness. The reason for this is that the present invention makes it possible for the developer particles to rotate efficiently by roughening the portion of the developer amount regulating blade that is in contact with the developer carrier, thereby allowing the developer carrier to rotate efficiently. We thought that it was possible to form a uniform developer thin layer on the body and to apply tribo uniformly to the developer particles, and as a result, we obtained knowledge that image unevenness, development streaks and ghosting can be suppressed. .

  As a result of further research, it has been found that the charge control surface of the blade member is not roughened to form irregularities, but the interval between the irregularities is important. From the relationship with the toner particle diameter and the type of the developer as a specific range of the unevenness interval, by setting the specific range, it is possible to suppress adhesion and fusion of the toner particles to the blade member, As a result, the inventors have obtained knowledge that generation of development streaks can be suppressed, and have completed the present invention based on such knowledge.

  That is, the present invention provides a roller-shaped developer carrying member that conveys developer from a developer container of an electrophotographic apparatus toward a developing unit, a blade member that contacts the developer carrying member, and supports the blade member. And a uniform thin layer while the developer is triboelectrically charged between the blade member and the developer carrier, and the uniform thin layer developer is formed on the latent image carrier. In a developer amount regulating blade in a developing device that is supplied to an image and performs development, the blade member has a ten-point roughness average (Rz) of 2 to 25 μm at least in a contact portion with the developing carrier. In addition, the present invention relates to a developer amount regulating blade characterized by having a roughened surface having an uneven average interval (Sm) of 1 to 400 μm.

  The developer amount regulating blade of the present invention causes image unevenness, image streaks, ghosts, etc., which are caused by the high-speed rotation of the developer carrier in the developing device accompanying the increase in the speed of the electrophotographic process, on the developer carrier. By forming a uniform thin layer of the developer, it can be suppressed by applying a predetermined tribo to the developer.

  The developer amount regulating blade of the present invention includes a roller-shaped developer carrying member that conveys the developer from a developer container of an electrophotographic apparatus toward a developing unit, a blade member that contacts the developer carrying member, A support member that supports the blade member, and the developer is formed into a uniform thin layer while frictionally charging the developer between the blade member and the developer carrier, and the uniform thin layer developer is formed on the latent image carrier. In the developer amount regulating blade in the developing device that is supplied to the electrostatic latent image for development, the blade member has a ten-point roughness average (Rz) at least at a contact portion with the developing carrier. The surface is not particularly limited as long as it has a roughened surface having a roughness average interval (Sm) of 1 to 400 μm and 2 to 25 μm.

  The developer amount regulating blade of the present invention is provided in a developing device of an electrophotographic apparatus, and as such an electrophotographic apparatus, any apparatus can be used as long as it forms an image using an electrophotographic process. Specifically, an electrophotographic copying machine, a laser beam printer, a facsimile, etc. can be mentioned.

  Further, as a developing device of these electrophotographic apparatuses, a roller-shaped developer carrying body that carries the developer stored in the developer container and supplies it to the electrostatic latent image, a blade member that contacts the roller-shaped developer carrying body, As long as it has a developer amount regulating blade provided with a support member that supports the blade member, for example, as shown in the schematic configuration diagram of FIG. ) And an electrophotographic photosensitive member in which an electrostatic latent image is formed on the surface portion of the exposed portion of the developer container 10 exposed to the outside of the developer container. And 12 having a developer carrier 11 disposed so as to be in contact with the development target, and a blade member 13 formed of a rubber material that is in contact with the surface of the developer carrier. .

  As a developer amount regulating blade of the present invention, FIG. 2 shows a development comprising a roller-shaped developer carrier, a blade member 20 that slides on the developer carrier, and a support member 21 to which the blade member is bonded. The example of a dosage control blade is shown. Here, a surface (adhesion surface) on which the blade member 20 is bonded to the support member 21 is formed between 20 and 21, and 25 is a surface (sliding surface) on which the developer slides on the developer carrier and the blade member. And a surface for controlling the charge of the developer (charge control surface). Further, the blade member 20 and the support member 21 are bonded and integrated to be fixed to the developer container, and the developer carrier 11 is separately fixed to the developer container. The blade member is brought into pressure contact with the developer carrier 11 at the sliding surface 25 and regulates the amount of developer particles passing through the sliding surface 25.

  The developer carrying member of the developer amount regulating blade may be any roller as long as it has a roller shape and can carry the developer on the surface thereof. The material can be appropriately selected depending on the material of the developer.

  The developer that can be carried by the developer carrying member may be either a negative developer or a positive developer, and the particle size of the developer can be appropriately selected.

  As the support member 21 of the developer amount regulating blade, any member may be used as long as it supports the blade member, and the material may be any of metal, ceramic, resin and the like. Specific examples include steel plates subjected to chromate treatment and surface treatment with a lubricating resin, elastic metal plates such as phosphor bronze and spring steel, plastics, and ceramics.

  Further, the blade member 20 of the developer amount regulating blade is provided in contact with and pressed against the surface of the developer carrying member 11, and the developer carried by the developer carrying member is developed with the excess. The toner particles removed from the surface of the developer carrier to a fixed amount and the polarity of the toner particles of the developer passing between the developer carrier and the opposite polarity to the electrostatic latent image formed on the photoreceptor of the electrophotographic apparatus Is given a predetermined triboelectric charge.

  The blade member has a ten-point roughness average (Rz) of 2 to 25 μm and an uneven average interval (Sm) of 1 to 400 μm at least at a contact portion with the developer carrier such as a ridge line portion. Has a roughened surface. When the ten-point roughness average (Rz) of the roughened surface (charge control surface) of the blade member is 2 μm or more, the developer toner particles can be rotated between the developer carrying member and the blade member, and development is performed. The developer on the developer carrying member is made to drop off the surplus and is carried as a thin layer on the developer carrying member, whereby sufficient triboelectric charge is imparted. On the contrary, if the ten-point roughness average (Rz) of the roughened surface of the blade member is 25 μm or less, the developer particles may be fitted into the large roughness recess of the blade member and sandwiched between the profiles. Therefore, sufficient triboelectric charging can be performed, and further, it is possible to suppress the occurrence of image defects due to the aggregation of the developer.

  The ten-point average roughness (Rz) on the roughened surface of the blade member is substantially the same as the ten-point average roughness Rz1 in a direction substantially perpendicular to the axial direction of the developer carrier and the axial direction of the developer carrier. The absolute value of the difference from the ten-point average roughness Rz2 in the parallel direction is preferably in the range of 1 μm or less. When the difference between Rz1 and Rz2 is 1 μm or less, the developer toner particles supplied from all directions are efficiently rotated by contact with the roughened surface of the blade member, and are uniformly distributed on the developer carrier. Thus, a thin developer layer having a uniform film thickness can be formed. Furthermore, the retention of the developer can be suppressed, and the adhesion and fusion of the developer to the surface of the developer amount regulating blade can also be suppressed.

  The ten-point average roughness Rz can be a value measured based on JIS B 0601 using a surface roughness measuring machine.

  In the roughened surface of the blade member, it is preferable that the average interval (Sm) of the irregularities is 1 to 400 μm. If the average interval (Sm) of the unevenness is 1 μm or more, the effect of roughening can be obtained and the toner particles can be freely rotated. Further, if the average interval (Sm) of the unevenness is 400 μm or less, the retention of toner particles can be suppressed, the adhesion and fusion of the developer to the blade member can be suppressed, and the development streaks can be suppressed. The average interval (Sm) of the unevenness is the average height in the height direction of the unevenness, that is, the level surface where the average value of the height (+) of the mountain and the depth (−) of the valley is 0, and the uneven surface Is the average value of the measured length (Smi) of the distance between two adjacent points of intersection with and is obtained by the following equation (1).

かかる凹凸曲面と水準面との交点の隣り合う２点間の距離の測定長（Ｓｍｉ）は、表面粗さ測定機を用い、ＪＩＳ Ｂ ０６０１に基づいて計測することができる。

The measurement length (Smi) of the distance between two adjacent points of intersection of the uneven curved surface and the level surface can be measured based on JIS B 0601 using a surface roughness measuring machine.

  Such a roughened surface of the blade member is preferably formed by a method including a physical method and / or a chemical method. Specific examples of the physical method for roughening the surface of the blade member include a sand blast method, a shot blast method, and a method using a sand paper / roughened film. Alternatively, a method of roughening the surface of the drum-shaped mold such as centrifugal molding or continuous injection molding and transferring the roughened surface to the roughened surface of the blade member may be used.

  Specific examples of the chemical method for roughening the surface of the blade member include an etching method and a method for forming a film containing roughened fine particles. Examples of the roughened fine particles include inorganic fine particles such as silica (SiO2), alumina (Al2O3), silicon carbide (SiC), magnenite (Fe3O4), titanium oxide (TiO2), tin oxide (SnO2), polycarbonate fine particles, Organic fine particles such as polyethylene fine particles, polypropylene fine particles, polyphenol fine particles, polysilicon fine particles, polyamide fine particles, acrylic fine particles, and melamine resin fine particles, and other inorganic / organic hybrid fine particles can be used. A combination of more than one species can also be used.

  The methods for roughening the surface of the blade member may be used in appropriate combination as necessary.

  Examples of the material of the blade member include thermosetting polyurethane having a rubber elasticity, silicone rubber, liquid rubber and the like from the viewpoint of mechanical properties of wear resistance. The material can be appropriately selected depending on the material of the developer carrying member.

  As a method for producing such a developer amount regulating blade, using the above materials, a method according to a conventional method, specifically, a prepolymer method, a semi-one-shot method, a one-shot method, etc. It can be appropriately selected depending on the material used for the blade member. As a manufacturing method of the developer amount regulating blade, for example, an uncured composition of a rubber raw material is prepared, injected into a centrifugal molding machine, heat-molded, and cut into a predetermined dimension to obtain a blade member. An example is a method in which the obtained blade member is fixed to the prepared support member by a method such as adhesion to form a developer amount regulating blade.

  Other manufacturing methods for the developer amount regulating blade member include, for example, a method in which a support member is inserted into a mold and a rubber raw material for molding the blade member is injected to produce an integrally molded blade, or a support member is used. A molding method in which the rubber raw material is poured into the mold and cured and reacted at the same time by being cured and held at the blade member molding die, a method of injecting the rubber raw material into a groove carved in the outer peripheral surface of the molding drum, and heat curing. Can be mentioned.

  The operation of such a developer amount regulating blade in the developing device will be described.

The developer carrier 11 rotates in the direction of the arrow, whereby the developer particles 23 are conveyed to the sliding surface 25. At this time, since the blade member is in contact with the developing carrier 11 at the charge control surface and the sliding surface, the developer particles are given a predetermined triboelectric charge, and further developed through the sliding surface 25 and conveyed to the photosensitive member. The amount of agent particles can be regulated.
At this time, since the blade member has a rough surface having a specific ten-point roughness average (Rz) and uneven average interval (Sm), the developer toner particles can freely rotate and become a uniform thin film. And supported on a developer carrier. For this reason, the developer toner particles are uniformly and sufficiently charged with electric charges (tribo). For this reason, the occurrence of image unevenness, image streaks, and ghosts in the output image of the electrophotographic apparatus is suppressed.

  Examples of the present invention will be described below, but the technical scope of the present invention is not limited to these examples. Unless otherwise specified, commercially available high-purity products were used as reagents.

  The developer amount regulating blade of the present invention was produced as follows.

  As a support member, an electrogalvanized steel sheet gin coat 21 (trade name: manufactured by Nippon Steel Co., Ltd.) having a non-chromium surface treatment layer containing a urethane-modified olefin resin and an acrylic-modified olefin resin is used. Melt adhesive Elfan-UH (trade name: manufactured by Nippon Matai Co., Ltd.) was temporarily bonded.

  Next, 100 parts by mass of adipate-based urethane prepolymer (Mn 2000, NCO content 6.25% by mass), 3.7 parts by mass of 1,4-butanediol, and 1.9 parts by mass of trimethylolpropane were mixed in a casting machine mixing chamber. The rubber raw material mixture was obtained by mixing and stirring inside. The obtained rubber raw material mixture was poured into a centrifugal molding machine, heat-molded at 130 ° C. for 1 hour, demolded and heat-cured to obtain a sheet-like polyurethane elastomer. On the mold surface of the centrifugal molding machine used here, a layer (roughening member) having a desired ten-point roughness average (Rz) and an average interval of irregularities is formed in advance by dispersing the roughened fine particles. Then, this roughening member was placed, and the rubber raw material mixture was poured onto the layer, followed by heat molding. By molding by this method, the ten-point roughness average (Rz) of the roughened member and the average interval of the irregularities were transferred to the surface of the polyurethane elastomer to obtain a roughened blade member. By changing the particle size and amount of the roughened fine particles contained in the roughening member, polyurethane elastomers having different ten-point roughness averages (Rz) and average intervals of unevenness (Sm) were obtained. Polyurethane elastomers having different ten-point roughness average (Rz) and average interval of unevenness (Sm) are cut into predetermined dimensions, respectively, to form a blade member, and a support sheet metal temporarily bonded to the blade member and the hot melt adhesive; Were heated and bonded to obtain a developer amount regulating blade (Examples 1 to 4, Comparative Examples 1 to 8).

About the obtained developer amount regulating blade, the ten-point average roughness (Rz) and the uneven average interval (Sm) were measured using a surface roughness measuring machine SE3500 (manufacturer name: manufactured by Kosaka Laboratory Co., Ltd.). Measured based on B 0601. The ten-point roughness average in a direction substantially perpendicular to the axial direction of the developer carrier is Rz1 (μm), and the ten-point roughness average Rz2 (μm) in a direction substantially parallel to the axial direction is the difference between Rz1 and Rz2. The absolute value was ΔRz.
[Example 1]
A roughening member having an average particle diameter of 2 to 3 μm was used, and a developer amount regulating blade having a roughened surface of the blade member of Rz1, Rz2 = 2 μm, Sm = 1 μm was used.
[Example 2]
A roughening member having an average particle diameter of 2 to 3 μm was used, and the amount of roughened fine particles was increased from that in Example 1, and a blade amount roughening surface of the blade member was Rz1, Rz2 = 2 μm, Sm = 400 μm. used.
[Example 3]
A roughening member having an average particle diameter of 5 to 6 μm was used, and a developer amount regulating blade having a roughened surface of the blade member of Rz1, Rz2 = 25 μm, Sm = 1 μm was used.
[Example 4]
A roughening member having an average particle diameter of 5 to 6 μm was used, and the amount of roughening fine particles was increased from that of Example 3, and a blade amount roughening surface of the blade member was Rz1, Rz2 = 25 μm, Sm = 400 μm. used.
[Example 5]
The mold surface of the centrifugal molding machine was directly roughened with sandpaper, and a polyurethane elastomer was injected thereon, followed by heat molding to obtain a developer amount blade. The surface of the blade member thus obtained was Rz1 = 7 μm, Rz2 = 1 μm, and Sm = 350 μm.
[Comparative Example 1]
A roughening member having an average particle diameter of 2 to 3 μm was used, and a developer amount regulating blade having a roughened surface of the blade member of Rz1, Rz2 = 1 μm, Sm = 1 μm was used.
[Comparative Example 2]
A roughening member having an average particle diameter of 2 to 3 μm was used, and a developer amount regulating blade having a roughened surface of the blade member of Rz1, Rz2 = 1 μm, Sm = 400 μm was used.
[Comparative Example 3]
A roughening member having an average particle diameter of 2 to 3 μm was used, and a developer amount regulating blade having a roughened surface of the blade member of Rz1, Rz2 = 2 μm, and Sm = 0.8 μm was used.
[Comparative Example 4]
A roughening member having an average particle diameter of 5 to 6 μm was used, and a developer amount regulating blade having a roughened surface of the blade member of Rz1, Rz2 = 2 μm, Sm = 420 μm was used.
[Comparative Example 5]
A roughening member having an average particle diameter of 5 to 6 μm was used, and a developer amount regulating blade having a roughened surface of the blade member of Rz1, Rz2 = 27 μm and Sm = 1 μm was used.
[Comparative Example 6]
A roughening member having an average particle diameter of 5 to 6 μm was used, and a developer amount regulating blade having a roughened surface of the blade member of Rz1, Rz2 = 27 μm and Sm = 400 μm was used.
[Comparative Example 7]
A roughening member having an average particle diameter of 5 to 6 μm was used, and a developer amount regulating blade having a roughened surface of the blade member of Rz1, Rz2 = 25 μm and Sm = 0.8 μm was used.
[Comparative Example 8]
A roughening member having an average particle diameter of 5 to 6 μm was used, and a developer amount regulating blade having a roughened surface of the blade member of Rz1, Rz2 = 25 μm, Sm = 420 μm was used.

  The developer amount regulating blade thus produced was incorporated into a cartridge for LASER SHOT-LBP (manufactured by Canon Inc.), and ghosts and image stripes were evaluated. For ghosts, ◯ indicates that no ghost occurred, △ indicates that a slight ghost was confirmed, and × indicates that a ghost was clearly confirmed. In the development streak, the case where no generation of the image streak was observed was marked with ◯, and the case where some change was confirmed was marked with Δ, x depending on the degree. The results are shown in Tables 1 and 2.

  Further, the toner amount M / S (g / cm 2) per unit area was calculated by measuring the toner amount (M) of a certain area (S) on the surface of the developer carrying member. Each value was measured when solid white and solid black were output, and the difference (solid white M / S−solid black M / S) was taken as ΔM / S. When ΔM / S is smaller, the toner is uniformly charged, and the occurrence of ghost is suppressed. The results are shown in Tables 1 and 2.

上記の結果から、実施例では、画像スジ、ゴーストの発生がない良好な画像が得られた。これに対して、比較例１、２の表面十点平均粗さ（Ｒｚ）が１μｍ以下では、ΔＭ／Ｓの値が大きく、ゴーストの発生も見られた。また、比較例５、６の表面十点平均粗さ（Ｒｚ）が２５μｍ以上ではゴーストの発生は僅かに確認される程度だが、現像スジの発生が見られた。さらに比較例３、７の現像剤量規制ブレード表面の凹凸の平均間隔（Ｓｍ）が１μｍ以下ではΔＭ／Ｓの値が大きく、ゴーストの発生も見られた。また、比較例４、８の表面の凹凸の平均間隔（Ｓｍ）が４００μｍ以上では、ゴーストも発生し、現像スジも確認された。

From the above results, in the example, a good image with no image streak or ghost was obtained. On the other hand, when the surface ten-point average roughness (Rz) of Comparative Examples 1 and 2 was 1 μm or less, the ΔM / S value was large and ghosting was also observed. Further, when the surface ten-point average roughness (Rz) of Comparative Examples 5 and 6 was 25 μm or more, the occurrence of ghost was only slightly confirmed, but development streaks were observed. Further, when the average interval (Sm) of the unevenness on the surface of the developer amount regulating blade of Comparative Examples 3 and 7 was 1 μm or less, the ΔM / S value was large, and ghosting was also observed. In addition, when the average interval (Sm) of the irregularities on the surfaces of Comparative Examples 4 and 8 was 400 μm or more, ghosting occurred and development streaks were also confirmed.

FIG. 2 is a schematic configuration diagram illustrating an example of a developing device of an electrophotographic apparatus to which the developer amount regulating blade of the present invention is applied. It is a figure which shows the typical block diagram of the developer amount regulation blade of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Developer container 11 Developer carrier 12 Photoconductor 13, 20 Blade member 21 Support member 23 Developer (toner particle)
25 Sliding surface

Claims (3)

  A roller-shaped developer carrying member that conveys developer from a developer container of an electrophotographic apparatus toward a developing unit, a blade member that contacts the developer carrying member, and a support member that supports the blade member The developer is made into a uniform thin layer while frictionally charging the developer between the blade member and the developer carrier, and the uniform thin layer developer is supplied to the electrostatic latent image formed on the latent image carrier for development. In the developer amount regulating blade in the developing device, the blade member has a ten-point roughness average (Rz) of 2 to 25 μm at least at a contact portion with the development carrier, and an unevenness average. A developer amount regulating blade having a roughened surface having a spacing (Sm) of 1 to 400 μm.   The roughened surface of the blade member has a ten-point average roughness Rz1 in a direction substantially perpendicular to the axial direction of the roller-shaped developer carrying member and a tenth surface in a direction substantially parallel to the axial direction of the roller-shaped developer carrying member. 2. The developer amount regulating blade according to claim 1, wherein the absolute value of the difference from the point average roughness Rz2 is in the range of 1 [mu] m or less.   3. The developer amount regulating blade according to claim 1, wherein the roughened surface of the blade member is formed by a method including a physical method and / or a chemical method on the surface of the blade member. .

Images