JP2008242228A - Blade, blade manufacturing device, developing device, image forming device - Google Patents

Abstract

A blade, a blade manufacturing apparatus, a developing apparatus, and an image forming apparatus capable of improving shape accuracy and improving assembly efficiency are proposed.
SOLUTION: A plate-shaped spring member 425 and an elastic member having a rectangular cross section which is fixed to one end of the spring member 425 and abuts against the developing roller 41a to regulate the layer thickness of the developer carried on the developing roller 41a. 430, the elastic member 430 is formed by molding urethane elastomer with a predetermined accuracy. The flatness and flatness of the surface 431 in contact with the developing roller 41a were formed with a predetermined accuracy. The squareness and chamfered shape of the tip 432 adjacent to the developing roller 41a were formed with a predetermined accuracy.
[Selection] Figure 4

Description

  The present invention relates to a blade, a blade manufacturing apparatus, a developing apparatus, and an image forming apparatus.

An image forming apparatus such as a laser printer includes a blade that abuts on the developing roller in order to charge the toner carried on the developing roller and to regulate the layer thickness of the toner carried on the developing roller. . By controlling the toner layer thickness with this blade, the printing quality is improved and stabilized.
In order to regulate the layer thickness of the toner carried on the developing roller to be constant, it is necessary to position and assemble the blade with high accuracy with respect to the developing roller. In particular, it is required that the shape accuracy of the tip of the blade contacting the developing roller be formed with high accuracy. For example, a method of cutting the blade in the longitudinal direction after holding the blade on the rigid holding member is disclosed. (Patent Document 1).
JP-A-5-265361

However, in the above-described technique, there are not a few cases where burrs are generated at the tip of the blade that has been cut and formed, and the perpendicularity of the tip is less than a desired value. For this reason, there is a problem that the toner layer thickness becomes non-uniform.
Further, in order to position and assemble the blade with respect to the developing roller with high accuracy, it is necessary to perform so-called shim adjustment, and there is a problem that work efficiency is low.
For this reason, improvement in blade shape accuracy and efficiency in blade assembly are required.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to propose a blade, a blade manufacturing apparatus, a developing apparatus, and an image forming apparatus capable of improving shape accuracy and improving assembly efficiency.

In the blade, the blade manufacturing apparatus, the developing apparatus, and the image forming apparatus according to the present invention, the following means are adopted in order to solve the above problems.
According to a first aspect of the present invention, there is provided a plate-shaped spring member and an elastic member having a rectangular cross section which is fixed to one end of the spring member and abuts against the developing roller to regulate the layer thickness of the developer carried on the developing roller. The elastic member is formed by molding a urethane elastomer with a predetermined accuracy.
Thereby, the layer thickness of the toner carried on the developing roller can be regulated uniformly.

Further, the flatness and flatness of the surface in contact with the developing roller are formed with a predetermined accuracy.
Accordingly, the elastic member can be pressed against the developing roller with a uniform contact force, and the toner layer thickness can be regulated uniformly.

Further, the squareness and chamfered shape of the tip adjacent to the developing roller are formed with a predetermined accuracy.
As a result, it is possible to avoid so-called white streaks from occurring in the toner carried on the developing roller.

In addition, a mark that allows the tip to be visually confirmed is provided.
Thereby, the misassembly of an elastic member can be prevented.

According to a second aspect of the present invention, there is provided an elastic member having a rectangular cross section which is fixed to one end of a plate-shaped spring member and abuts against the developing roller to regulate the layer thickness of the developer carried on the developing roller. In the blade manufacturing apparatus, the flatness and flatness of the inner wall surface forming the contact surface to the developing roller are formed with a predetermined accuracy.
Accordingly, the elastic member can be pressed against the developing roller with a uniform contact force, and the toner layer thickness can be regulated uniformly.

Further, the squareness and chamfering shape of the inner wall corner portion forming the tip adjacent to the developing roller are formed with a predetermined accuracy.
As a result, it is possible to avoid so-called white streaks from occurring in the toner carried on the developing roller.

A third invention is a developing device having a developing roller and a blade that abuts against the developing roller and regulates a layer thickness of the developer carried on the developing roller, wherein the blade is the first invention. Or a blade manufactured by the blade manufacturing apparatus according to the second invention.
As a result, a developer having a uniform layer thickness can be carried on the developing roller.

According to a fourth aspect of the invention, there is provided a photosensitive member, a charger for charging the photosensitive member, an exposure unit for exposing the photosensitive member charged by the charger to form an electrostatic latent image, and the exposed photosensitive member. In the image forming apparatus having a developing unit that develops and visualizes a body and a transfer unit that transfers an image developed on the photosensitive member to a recording material, the developing unit according to the third invention is used as the developing unit. An apparatus is used.
Thereby, a high-quality image can be formed on the recording material.

Embodiments of a blade, a blade manufacturing apparatus, a developing apparatus, and an image forming apparatus according to the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic diagram illustrating a configuration of a laser printer according to an embodiment of the present invention.
The laser printer (image forming apparatus) 10 includes an exposure unit 20, a photosensitive drum 30, an attaching / detaching unit (developing apparatus) 40, a primary transfer unit 51, an intermediate transfer body 55, a cleaning unit 35, a secondary transfer unit 64, and a fixing unit 65. The operation panel 80 and the control unit 90 are configured.

  The exposure unit 20 is located below the photosensitive drum 30 and includes a semiconductor laser, a polygon mirror, an F-θ lens, and the like. Image data to be printed input from the host side is subjected to image processing and the like by the control unit 90, and then converted to pulse data for driving laser light. The exposure unit 20 irradiates the photosensitive drum 30 with a laser based on the pulse data.

  The photosensitive drum 30 is composed of a cylindrical conductive substrate and a photosensitive layer formed on the outer peripheral surface thereof, and is provided in the laser printer 10 so as to be rotatable around a central axis. In addition, a charging unit 31 is provided below the photosensitive drum 30 to charge the photosensitive drum 30. By irradiating the charged photosensitive drum 30 with the laser from the exposure unit 20, an electrostatic latent image is formed on the surface of the photosensitive drum 30. As a result, the photosensitive drum 30 carries a latent image.

  The developing device 40 is configured such that a plurality of developing units (toner cartridges) 41, 42, 43, and 44 can be attached and detached. In the laser printer 10, toner cartridges 41, 42, 43, 44 containing four color (C, M, Y, K) developers (toner T) can be mounted.

The primary transfer unit 51 is located above the photosensitive drum 30 and transfers the toner image on the photosensitive drum 30 developed by the developing device 40 to the intermediate transfer member 55.
The intermediate transfer member 55 is an endless belt in which an aluminum vapor deposition film is provided on the surface of a PET film, and a semiconductor paint is formed and laminated on the surface layer. The intermediate transfer member 55 is rotationally driven along the primary transfer unit 51, rollers 52 and 53, and the secondary transfer unit 64 at substantially the same peripheral speed as the photosensitive drum 30.

  The secondary transfer unit 64 (secondary transfer roller pair 64a, 64b) is for transferring the toner image formed on the intermediate transfer body 55 to a recording medium 70 such as paper, film, cloth or the like. Further, the secondary transfer unit 64 (64a, 64b) also serves as a roller for conveying the recording medium 70 conveyed from below upward.

  The fixing unit 65 (fixing roller pair 65a, 65b) is positioned above the secondary transfer unit 64 (64a, 64b), and the toner image transferred to the recording medium 70 is heat-fused to the recording medium 70 to be a permanent image. It is for.

  The cleaning unit 35 is provided between the primary transfer unit 51 and the charging unit 31, and has a rubber cleaning blade (not shown) in contact with the surface of the photosensitive drum 30. After the toner image is transferred to the intermediate transfer member 55 by the primary transfer unit 51, the cleaning unit 35 scrapes off and removes the toner remaining on the photosensitive drum 30 with a cleaning blade. The waste toner scraped off is stored in a container.

Further, the laser printer 10 includes a paper feed tray 60 in which a plurality of recording media 70 are accommodated, a pair of paper feed rollers 61 a and 61 b that take out the recording media 70 one by one from the paper feed tray 60, and a pair of paper feed rollers 61 a and 61 b. The recording medium 70 conveyed from the fixing unit 65 (fixing roller pair 65a, 65b) and the feed roller pair 62a, 62b and the gate roller pair 63a, 63b for sandwiching and conveying the recording medium 70 conveyed from the recording medium 70 further downstream. And the post-fixing roller pair 66a, 66b for transporting the recording medium 70 to the re-transport path h, and the recording medium 70 transported from the post-fixing roller pair 66a, 66b for discharging the recording medium 70 from the discharge port. In order to convey the recording medium 70 conveyed to the discharge roller pair 67a, 67b and the reconveying path h to the gate roller pair 63a, 63b. Refeed roller pairs 68a, 68b, the provided.
Further, a switching guide 69 for switching the transported recording medium 70 to the re-transport path h is also provided.

  In addition, the laser printer 10 includes an operation panel 80 that can specify a printing direction, a type of a printing medium, and the like on the upper part of the housing, and serves as a user interface.

Next, the configuration of the toner cartridges 41, 42, 43, and 44 will be described.
FIG. 2 is a perspective view showing the toner cartridge 41. FIG. 3 is a cross-sectional view showing the configuration of the toner cartridge 41.
Hereinafter, the toner cartridge 41 will be described, but the other toner cartridges 42, 43, and 44 have the same configuration.

  The toner cartridge 41 includes a developing roller 41a, a housing 410, a toner container 413, a regulating blade 420, a seal member 417, a toner supply roller 41c, and the like.

  The developing roller 41a is made of a metal such as an aluminum alloy or an iron alloy, and is subjected to nickel plating, chrome plating, or the like as necessary. The developing roller 41 a has both longitudinal ends pivoted by a pair of roller holders 440 so that the developing roller 41 a can rotate in a direction (counterclockwise in FIG. 3) opposite to the rotation direction of the photosensitive drum 30 (clockwise in FIG. 3). It is supported.

  Further, when the toner cartridge 41 faces the photosensitive drum 30, there is a gap between the developing roller 41 a and the photosensitive drum 30. That is, the toner cartridge 41 develops the electrostatic latent image formed on the photosensitive drum 30 in a non-contact state. When developing the latent image formed on the photosensitive drum 30, an alternating electric field is formed between the developing roller 41 a and the photosensitive drum 30.

  The housing 410 is manufactured by fusing a plurality of paired molded housing parts, that is, an upper housing part 411 and a lower housing part 412. The housing 410 forms a toner storage portion 413 that can store the toner T. As the developing device 40 rotates, the toner cartridges 41, 42, 43, and 44 rotate, whereby the toner T of the toner cartridges 41, 42, 43, and 44 is agitated.

The regulating blade (blade) 420 applies a charge to the toner T carried on the developing roller 41a, and regulates the layer thickness of the toner T carried on the developing roller 41a.
The regulation blade 420 includes a rubber member 430 and a rubber support portion 425. The rubber support portion 425 is a thin plate having a spring property such as phosphor bronze or stainless steel. The material for forming the rubber member 430 will be described later.
The rubber member 430 is fixed (adhered) to one end of the upper end surface of the rubber support portion 425 using a double-sided tape or the like. Further, the other end of the rubber support portion 425 is welded (laser welding) to the upper surface of the mounting portion 440 a of the roller holder 440, and is fixed to the housing 410 via the roller holder 440.
Further, a blade back member 414 made of malt plane or the like is provided on the side opposite to the developing roller 41 a side of the regulating blade 420.

The rubber member 430 is pressed against the developing roller 41a by the elastic force due to the bending of the rubber support portion 425. In addition, the blade back member 414 prevents the toner T from entering between the rubber support portion 425 and the housing 410, stabilizes the elastic force due to the bending of the rubber support portion 425, and prevents the rubber from the back of the rubber member 430. The rubber member 430 is pressed against the developing roller 41a by urging the member 430 toward the developing roller 41a.
Therefore, the blade back member 414 improves the uniform contact property of the rubber member 430 to the developing roller 41a.

  The seal member 417 prevents the toner T in the toner cartridge 41 from leaking out of the device and collects the toner T on the developing roller 41a that has passed through the developing position into the developing device 40 without being scraped off. The seal member 417 is a seal made of a polyethylene film or the like. The seal member 417 is supported by a seal support sheet metal 418 and is attached to the housing 410 via the seal support sheet metal 418. Further, a seal urging member 419 made of malt plain or the like is provided on the opposite side of the seal member 417 from the developing roller 41 a side. The seal member 417 is developed by the elastic force of the seal urging member 419. It is pressed against.

The toner supply roller 41c is provided in the toner storage unit 413, and supplies the toner T stored in the toner storage unit 413 to the developing roller 41a. The toner supply roller 41c is made of polyurethane foam or the like, and is in contact with the developing roller 41a in an elastically deformed state. The toner supply roller 41c is disposed below the toner container 413 and is configured to be rotatable about a central axis. Further, the toner supply roller 41c rotates in a direction (clockwise direction in FIG. 3) opposite to the rotation direction of the developing roller 41a (counterclockwise direction in FIG. 3).
The toner supply roller 41c also has a function of peeling off the toner T remaining on the developing roller 41a after development from the developing roller 41a.

Next, the operation of the laser printer 10 configured as described above will be described.
First, an image to be printed output from the host side is input to the control unit 90, and pulse data for driving laser light is generated. The exposure unit 20 is driven based on the pulse data, and the laser light irradiates the photosensitive drum 30. The photosensitive drum 30 is charged by a charging unit 31, and an electrostatic latent image is formed on the surface thereof by irradiation with laser light.

  The toner is supplied from the toner cartridges 41, 42, 43, and 44 to the photosensitive drum 30 through the developing rollers 41a, 42a, 43a, and 44a. As a result, the photosensitive drum 30 is developed with toner, and a toner image is formed on the surface thereof.

  The photosensitive drum 30 further rotates, and the toner image formed on the photosensitive drum 30 is transferred to the intermediate transfer member 55 by the primary transfer unit 51. The toner image on the intermediate transfer member 55 is moved to the secondary transfer unit 64 (64a, 64b) by driving the drive roller 52.

On the other hand, the recording medium 70 fed to the paper feed tray 60 is fed one by one by a pair of paper feed rollers 61a and 61b and conveyed downstream. The transported recording medium 70 is further sandwiched between feed roller pairs 62a and 62b and gate roller pairs 63a and 63b and transported to secondary transfer roller pairs 64a and 64b.
In the secondary transfer unit 64 (secondary transfer roller pair 64a and 64b), the toner image formed on the intermediate transfer body 55 is transferred to the recording medium 70 by applying a secondary transfer bias to the secondary transfer roller 64b side. The The transferred recording medium 70 is conveyed to the fixing unit 65, and the transferred toner image is fused by being heated and pressed by the fixing roller pair 65a and 65b. Then, the recording medium 70 is conveyed to the switching guide 69 by the fixing unit 65 (65a, 65b).

The switching guide 69 is normally provided so as to block the conveyance path from the fixing unit 65 (65a, 65b) by its own weight. Then, the leading end of the recording medium 70 conveyed from the fixing unit 65 (65a, 65b) comes into contact with the switching guide 69 and pushes up the guide 69, thereby being conveyed to the post-fixing roller pair 66a, 66b.
The recording medium 70 conveyed to the post-fixing roller pair 66a, 66b is further conveyed and sandwiched between the discharge roller pair 67a, 67b and discharged from the laser printer 10.

When double-sided printing is specified on the host side or the operation panel 80, the controller of the control unit 90 causes the rotation of the post-fixing roller pair 66a, 66b and the discharge roller pair 67a, 67b to be the rotation direction so far. Control to rotate in the reverse direction. That is, when the trailing edge of the recording medium 70 conveyed from the pair of fixing rollers 65a and 65b passes through the switching guide 69, the switching guide 69 blocks the conveyance path from the pair of fixing rollers 65a and 65b by its own weight, and at the same time. The blocked re-transport path h is opened. In this state, the post-fixing roller pair 66a, 66b is driven in the reverse direction of rotation, so that the recording medium 70 sandwiched between the post-fixing roller pair 66a, 66b is transported to the re-transport path h. .
The recording medium 70 conveyed to the re-conveying path h is conveyed again to the gate roller pair 63a and 63b via the refeed roller pair 68a and 68b, and is transferred to the recording medium 70 by the secondary transfer roller pair 64a and 64b. The back side is printed and double-sided printing is performed.

The toner cartridge 41 operates as follows. That is, the toner T accommodated in the toner accommodating portion 413 is supplied to the developing roller 41a by the rotation of the toner supply roller 41c. The toner T supplied to the developing roller 41a reaches the contact position of the regulating blade 420 as the developing roller 41a rotates, and is charged when passing through the contact position, and the layer thickness is regulated. Is done.
The toner T on the developing roller 41a whose layer thickness is regulated reaches a developing position facing the photosensitive drum 30 by further rotation of the developing roller 41a, and is placed on the photosensitive drum 30 under an alternating electric field at this developing position. It is used for development of the formed latent image.
Then, the toner T on the developing roller 41a that has passed the developing position by further rotation of the developing roller 41a passes through the seal member 417 and is collected in the toner cartridge 41 without being scraped off by the seal member 417. Further, the toner T still remaining on the developing roller 41a can be peeled off by the toner supply roller 41c.

FIG. 4 is a view showing a peripheral structure of the regulating blade 420.
The regulating blade 420 regulates the layer thickness of the toner T carried on the developing roller 41a. In order to keep the layer thickness of the toner T constant, the rotating shaft of the developing roller 41a and the rubber support portion 425 are fixed. It is necessary to keep the distance L to the lower surface constant. For example, it is required to define the error range of the distance L to be, for example, about ± 0.03 mm.
In order to keep the error range of the distance L within the above-described value, the shape accuracy of the roller holder 440 and the rubber member 430 is important.
In addition, since the plate | board thickness error is prescribed | regulated by the standards, such as JIS, as for the rubber | gum support part 425, only the shape accuracy of the roller holder 440 and the rubber member 430 becomes important.
Hereinafter, the shape accuracy of the rubber member 430 will be described.

As an example of the shape accuracy of the rubber member 430, the following conditions are required.
(A) Thickness error: within ± 0.015 mm (b) Flatness of upper surface 431 (surface in contact with developing roller 41a): 0, 1 mm or less (c) Lower surface 425b of rubber support 425 and upper surface 431 of rubber member 430 Parallelism: 0.1 mm or less (d) Tip straightness: 0.1 mm or less (e) Surface roughness of the upper surface 431: No waviness or deformation (visual observation)

Furthermore,
(F) The tip 432 of the rubber member 430 is required to be free of burrs.
For example, when burrs of about 20 to 50 μm exist, streaks (portions where the toner T has been peeled off) are generated in the toner T layer carried on the developing roller 41a, and white streaks (unprinted streaks) appear on the printing paper. It will appear.
For this reason,
(G) The radius R of the tip 432 of the rubber member 430 is required to be within a radius of 30 μm.

FIG. 5 is a cross-sectional view of the mold 100 for molding the rubber member 430. FIG. 6 is an enlarged view of the tip 432 of the rubber member 430.
In order to form the rubber member 430 with the above-described shape accuracy, injection molding using a mold (blade manufacturing apparatus) 100 is performed. As a material for forming the rubber member 430, urethane elastomer (for example, T8375N, hardness 78 °) is used.
The mold (blade manufacturing apparatus) 100 includes a lower mold 110 in which a concave digging (cavity) is formed, and a plate-shaped upper mold 120. Then, when the lower mold 110 and the upper mold 120 are brought into close contact with each other, the space formed between the lower mold 110 and the upper mold 120 (the recessed digging portion of the lower mold 110) is filled with urethane elastomer. The rubber member 430 is molded.

The lower mold 110 includes an L-shaped first member 112 and a second member 113 disposed on the side of the first member 112. The inner corner 112 a of the lower mold 110 is a part that forms the tip 432 of the rubber member 430, and the bottom surface 112 b is a part that forms the upper surface 431.
Since the lower mold 110 is formed by machining, the rubber member 430 can be reliably and stably molded with a predetermined shape accuracy.
In particular, since the inner corner 112a is formed as an integral mold, no burrs are generated due to mold matching by combining two members. Moreover, since the internal angle 112a is formed by machining, the squareness is high, and therefore the squareness of the tip 432 of the rubber member 430 is also highly accurate.
Further, the bottom surface 112b is precisely machined to have high flatness and flatness by removing a cutter mark or the like formed at the time of machining by optical plating or polishing. Therefore, the flatness and flatness of the upper surface 431 of the rubber member 430 are also highly accurate.

As described above, the above-described condition of the shape accuracy can be reliably and stably achieved by injection molding the rubber member 430 by using the mold 100 using a urethane elastomer as a material.
It should be noted that the rubber member 430 needs to be fixed so that the front end 432 of the rubber member 430 is positioned on the front end side of the rubber support portion 425. It is desirable to form a mark M or the like in the vicinity of the tip 432 or the like so that the mounting direction is not mistaken during the mounting operation.

  Conventionally, since the rubber portion is formed of a two-pack type urethane rubber, it has been difficult to achieve the above-described shape accuracy condition. That is, the two liquids as raw materials are mixed and centrifuged to form a sheet-shaped urethane rubber, and then cut into a desired shape using a cutter to form a rubber portion. In the case of centrifugal molding, the error accuracy of the thickness of the rubber part is about ± 0.15 mm. For this reason, the mounting position (distance L) of the rubber member 430 is adjusted to be within an error accuracy of, for example, about ± 0.03 mm by shim adjustment.

  Conventionally, since the sheet-shaped urethane rubber is cut into a desired shape by a cutter, the perpendicularity of the tip is less likely to be, for example, about 0.3 mm due to the influence of the posture (falling) of the cutter. There wasn't. Moreover, since it cut | disconnects with a cutter, a burr | flash generate | occur | produced at the front end.

On the other hand, according to the present embodiment, the rubber member 430 has the above-described shape accuracy (a) to (e) reliably and stably. Further, since the chamfer with a radius of 30 μm or less is formed at the tip 432 of the rubber member 430, the conditions (f) and (g) can be achieved reliably and stably (see FIG. 6).
For this reason, the distance L can be reliably kept within an error accuracy of about ± 0.03 mm only by fixing the rubber member 430 to the rubber support portion 425.
As described above, when the rubber member 430 is used, it is not necessary to perform adjustment (shim adjustment) for inserting a shim between the rubber support portion 425 and the upper surface of the attachment portion 440a of the roller holder 440. Reduction and efficiency improvement. Moreover, since there is no variation in assembly, stable quality can be ensured.

  It should be noted that the various shapes and combinations of the constituent members shown in the above-described embodiments, the operations, the operation procedures, and the like are examples, and can be variously changed based on design requirements and the like without departing from the gist of the present invention. .

For example, as the shape accuracy required for the rubber member 430, the above-described (a) to (g) are examples, and are not limited to these values.
Although the case where T8375N and hardness of 78 ° are used as the urethane elastomer has been described, the present invention is not limited to this. For example, when the hardness is changed, the shape accuracy and the like of (a) to (g) required for the rubber member 430 are slightly different values.

It is a schematic diagram which shows the structure of the laser printer which concerns on embodiment of this invention. FIG. 3 is a perspective view illustrating a toner cartridge. FIG. 3 is a cross-sectional view illustrating a configuration of a toner cartridge. It is a figure which shows the surrounding structure of a control blade. It is sectional drawing of the metal mold | die 100 which shape | molds a rubber part. It is an enlarged view of the front-end | tip of a rubber part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Laser printer (image forming apparatus) 20 ... Exposure unit (exposure part) 30 ... Photosensitive drum (photoreceptor) 31 ... Charging unit (charger) 40 ... Developer (development part) 41 ... Toner Cartridge, 41a ... developing roller, 51 ... primary transfer unit (transfer part), 64 ... secondary transfer unit (transfer part), 65 ... fixing unit, 70 ... recording medium (recording material), 100 ... mold (blade manufacturing) Device), 112b ... bottom surface (inner wall surface), 112a ... inner angle (inner wall corner portion), 420 ... regulating blade (blade), 425 ... rubber support portion (spring member), 430 ... rubber member (elastic member), 431 ... upper surface (Contact surface), 432 ... tip, T ... toner (developer), M ... mark

Claims (8)

In a blade comprising: a plate-shaped spring member; and an elastic member having a rectangular cross section that is fixed to one end of the spring member and that contacts the developing roller and regulates the layer thickness of the developer carried on the developing roller ,
The blade is characterized in that the elastic member is formed by molding urethane elastomer with a predetermined accuracy.   The blade according to claim 1, wherein the flatness and flatness of the surface in contact with the developing roller are formed with a predetermined accuracy.   3. The blade according to claim 1, wherein a squareness and a chamfered shape of a tip adjacent to the developing roller are formed with a predetermined accuracy.   The blade according to claim 3, wherein a mark is provided so that the tip can be visually confirmed. A blade manufacturing apparatus for forming an elastic member having a rectangular cross section which is fixed to one end of a plate-shaped spring member and abuts against a developing roller to regulate a layer thickness of a developer carried on the developing roller. ,
A blade manufacturing apparatus, wherein the flatness and flatness of an inner wall surface forming a contact surface to the developing roller are formed with a predetermined accuracy.   A blade manufacturing apparatus, wherein a squareness and a chamfered shape of an inner wall corner portion forming a tip adjacent to the developing roller are formed with a predetermined accuracy. A developing device having a developing roller and a blade that contacts the developing roller and regulates the layer thickness of the developer carried on the developing roller;
As the blade, the blade according to any one of claims 1 to 4 or the blade manufactured by the blade manufacturing apparatus according to claim 5 or 6 is used as the elastic member. Developing device. A photoconductor, a charger for charging the photoconductor, an exposure unit for exposing the photoconductor charged by the charger to form an electrostatic latent image, and developing and visualizing the exposed photoconductor An image forming apparatus including: a developing unit that transfers the image developed on the photosensitive member to a recording material;
An image forming apparatus using the developing device according to claim 7 as the developing unit.

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