JP2003228232A - Developing device and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device by which a developing quality is improved by planarly uniformizing a toner quantity stuck to a toner carrier and a manufacturing method for the developing device. <P>SOLUTION: A supporting member 26 to which a blade 32 to scrape toner is fixed is formed into a bar-like shape whose cross section is Z-shaped by bending a steel plate whose thickness is ≥1.6 mm and possesses a planar seat part 22, a first side wall part 24 and a second side wall part 20. Warpage caused by bending the first side wall part 24 to the part 22 and that caused by bending the second side wall part 20 to the part 22 are mutually negated at the part 22, so that the flatness of the part 22 is lowered. Thus, the flatness of the top end part 30 of the blade 32 whose base end part is fixed at the part 22 is lowered. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device and its manufacturing method.

[0002]

2. Description of the Related Art Conventionally, there has been known a developing device which is provided in a printing device such as a laser printer or a copying machine and which attaches toner to a latent image formed on a photoconductor to develop the latent image. Such a developing device includes a toner carrier that carries toner on the outer peripheral wall surface and rotates. The excess toner attached to the toner carrier is scraped off by a blade that is in pressure contact with the toner carrier. In order to improve the development quality, it is necessary to flatten the tip of the blade in the direction parallel to the rotation axis of the toner carrier to make the amount of toner adhered to the toner carrier uniform.

Generally, the blade of the developing device is fixed to a supporting member held in the casing of the device. As the support member, for example, a rod-shaped member in which a metal plate is bent into a V shape to ensure rigidity is known.

[0004]

However, when the metal plate 102 is bent into a V shape by using the punch 100 and the die 104 shown in FIG. 2, the metal plate 102 generally projects inward in the longitudinal direction as shown in FIG. Warp. This phenomenon is caused by the metal plate 10
It becomes more remarkable as the thickness of 2 increases. When the flatness of the base end portion of the blade fixed to the support member increases, the flatness of the tip end portion that abuts the toner carrier also increases. Therefore, a metal plate having a large plate thickness is bent to be used as the blade support member. Therefore, it is difficult to increase the rigidity of the support member. For example, when a metal plate having a large plate thickness is bent and used as a supporting member for the blade, the flatness of the blade must be reduced by polishing the mounting surface of the blade after the bending process, resulting in an increase in manufacturing cost. become.

The present invention was devised to solve the above problems, and provides a developing device and a manufacturing method thereof for improving the development quality by making the amount of toner adhered to a toner carrier uniform on the surface. The purpose is to do.

[0006]

A developing device according to a first aspect of the present invention is a developing device according to the first aspect of the present invention, in which a toner carrier that carries toner on a cylindrical outer peripheral wall surface and rotates, and a cross section Z in which a steel plate having a plate thickness of 1.6 mm or more is bent.
A bar-shaped seat portion, a flat plate-shaped seat portion, a first side wall portion extending from one edge extending in the longitudinal direction of the seat portion in a direction substantially perpendicular to the seat portion, and a longitudinal direction of the seat portion A support member having a second side wall portion extending from the other edge in a direction substantially opposite to the first side wall portion, the longitudinal axis of which is provided in a posture parallel to the rotation axis of the toner carrier; A portion fixed to the seat portion, and a blade for scraping off the toner carried by the toner carrier at a tip portion parallel to the rotation axis of the toner carrier. Plate thickness 1.6
By using a steel plate of mm or more for the supporting member, the rigidity of the supporting member is increased, and as a result, the flatness of the tip portion of the blade is reduced. Generally, when a steel sheet is bent into a V shape, a compressive stress is generated in the inner region B of the neutral line and a tensile stress is generated in the outer region C of the neutral line as shown in FIG. Therefore, the metal plate 102 bent into a rod shape having a V-shaped cross section
Warps inward in the longitudinal direction as shown in FIG. In the developing device according to the first aspect of the invention, the first side wall portion and the second side wall portion are bent in substantially opposite directions with respect to the seat portion. For this reason, the warp caused by bending the first side wall portion with respect to the seat portion and the warp caused by bending the second side wall portion with respect to the seat portion cancel each other out in the seat portion, so that the flatness of the seat portion is reduced. Becomes smaller. As a result, the flatness of the tip end portion of the blade whose base end portion is fixed to the seat portion is reduced. Therefore, with the developing device according to the first aspect of the present invention, it is possible to improve the development quality by making the amount of toner attached to the toner carrier uniform on the surface.

Further, it is desirable that the lengths of the first side wall portion and the second side wall portion in the lateral direction are three times or more the plate thickness of the steel sheet. Further, it is desirable that the steel sheet is a cold-rolled steel sheet that has been electrogalvanized. Further, the cold rolled steel sheet is preferably a cold rolled stainless steel sheet.

A developing device according to a second aspect of the present invention comprises a toner carrier which carries toner on a cylindrical outer peripheral wall surface and rotates, and a bar having a U-shaped cross section formed by bending a steel plate having a plate thickness of 1.6 mm or more, A flat plate-shaped seat portion and a side wall portion extending in a direction substantially perpendicular to the seat portion from both side edges extending in the longitudinal direction of the seat portion and having a lateral direction length that is three times or more the plate thickness of the steel sheet. A supporting member having a longitudinal axis parallel to the rotation axis of the toner carrier, and a base end fixed to the outer wall surface of the seat, and parallel to the rotation axis of the toner carrier. And a blade for scraping off the toner carried by the toner carrier at its leading end. When the steel sheet is bent into a U-shaped cross section by sinking, generally, as shown in FIG. 4, a force is exerted on the steel sheet 200 so as to warp outward in the longitudinal direction. By balancing the compressive stress and tensile stress acting when the steel sheet is bent into a V-shaped cross section and the force acting when bending the steel sheet into a U-shaped cross section by making the width of the side wall portion 3 times or more the plate thickness. The flatness of the seat can be reduced. Therefore, according to the developing device of the second aspect of the present invention, it is possible to improve the developing quality by making the amount of toner attached to the toner carrier uniform on the surface.

Further, it is desirable that the steel sheet is a cold-rolled steel sheet that has been electrogalvanized. Further, the cold rolled steel sheet is preferably a cold rolled stainless steel sheet.

A method of manufacturing a developing device according to the third invention is
A toner carrier that rotates by carrying toner on a cylindrical outer peripheral wall surface; and a rod-shaped support member that has a flat plate-shaped seat portion and is provided with its longitudinal axis parallel to the rotation axis of the toner carrier. A method for manufacturing a developing device, comprising: a blade having a base end portion fixed to the seat portion and a blade scraping off the toner carried on the toner carrier at a front end parallel to a rotation axis of the toner carrier; By bending a steel plate having a thickness of 1.6 mm or more into a V shape twice to form a Z-shaped cross section of the steel plate,
The seat portion, a first side wall portion extending in a direction substantially perpendicular to the seat portion from one edge extending in the longitudinal direction of the seat portion, and the first side wall portion extending from the other edge extending in the longitudinal direction of the seat portion. And a second side wall portion extending substantially in the opposite direction. By bending the steel plate twice in a V shape to form the cross section of the steel plate in a Z shape, the warpage due to the bending of the first side wall portion with respect to the seat portion and the bending of the second side wall portion with respect to the seat portion Since the warp caused by each other cancels each other out in the seat portion, the flatness of the seat portion can be reduced. Therefore, according to the manufacturing method of the third aspect of the present invention, it is possible to manufacture a developing device in which the amount of toner attached to the toner carrier is made uniform on the surface and the development quality is improved.

Further, the steel sheet is bent twice in a V shape so that the lengths of the first side wall portion and the second side wall portion in the lateral direction are not less than three times the plate thickness of the steel sheet. Z
The flatness of the seat can be further reduced by forming the seat into a V shape.

A method of manufacturing a developing device according to a fourth aspect of the invention is
A toner carrier that rotates by carrying toner on a cylindrical outer peripheral wall surface; and a rod-shaped support member that has a flat plate-shaped seat portion and is provided with its longitudinal axis parallel to the rotation axis of the toner carrier. A method for manufacturing a developing device, comprising: a blade having a base end portion fixed to the seat portion and a blade scraping off the toner carried on the toner carrier at a front end parallel to a rotation axis of the toner carrier; By subjecting a steel plate having a thickness of 1.6 mm or more to a sink bending process, the seat portion and the edges on both sides extending in the longitudinal direction of the seat portion extend in a direction substantially perpendicular to the seat portion and have a lateral length. It is characterized in that the support member having a side wall portion having a thickness three times or more the thickness of the steel plate is formed. By balancing the compressive stress and tensile stress acting when the steel sheet is bent into a V-shaped cross section and the force acting when bending the steel sheet into a U-shaped cross section by making the width of the side wall portion 3 times or more the plate thickness. The flatness of the seat can be reduced.
Therefore, according to the manufacturing method of the fourth aspect of the present invention, it is possible to manufacture a developing device in which the amount of toner adhered to the toner carrier is made uniform on the surface and the development quality is improved.

Further, by performing the sinking bending process to form a linear recess on the inner wall surface of the seat portion along the side wall portion, the flatness in the vicinity of the edge extending in the longitudinal direction of the seat portion is further improved. Can be made smaller.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on a plurality of examples. (First Embodiment) FIG. 1 is a sectional view showing a developing device according to the first embodiment of the present invention. The developing device 10 is a device that adheres toner to the photoconductor 14 of the printing device and develops on the photoconductor, and includes a hopper 12, a toner carrier 18, and a support member 2.
6 and a blade 32.

The hopper 12 is fixed to a casing (not shown). The hopper 12 is a container that contains toner, and has an opening 16 formed therein. A part of the toner carrier 18 enters the hopper through the opening 16.

The toner carrier 18 is a cylindrical outer peripheral wall surface 1.
7, which has a rotation axis O extending in the direction perpendicular to the plane of FIG.
It is rotatably supported by a casing (not shown) centering around. Since the outer peripheral wall surface 17 of the toner carrying member 18 is exposed inside the hopper, toner adheres to the outer peripheral wall surface 17 inside the hopper, and the toner carrying member 18 is rotated by a driving device (not shown).
The toner is conveyed to the photoconductor 14 by rotating in the direction.

The blade 32 is composed of a spring portion 28 and an abutting portion 30 corresponding to the tip portion described in the claims. The spring portion 28 is formed of a metal plate of brass, phosphor bronze, or the like into an elongated, generally rectangular flat plate shape.
The spring portion 28 has its base end fixed to the support member 26 so that its longitudinal axis is in a posture parallel to the rotation axis of the toner carrier 18. The contact portion 30 is formed of an elastic material such as rubber in the shape of an elongated flat plate, and is fixed to the tip of the spring portion 28 so that its longitudinal axis is parallel to the rotation axis O of the toner carrier 18. . The contact portion 30 is in contact with the outer peripheral wall surface 17 of the toner carrier 18 with a predetermined pressure by the spring portion 28 bending in its lateral direction. Toner carrier 18
When the toner carrier 18 rotates in the R direction, the toner adhering to the outer peripheral wall surface 17 of the toner is scraped off by the contact portion 30, and the toner remaining on the outer peripheral wall surface 17 of the toner carrier 18 evenly adheres to the photoconductor 14. . The spring portion 28 may be directly brought into contact with the toner carrier 18 without providing the contact portion 30.

The supporting member 26 has a cross section Z formed by pressing a steel plate (SECC) electroplated with zinc (described later).
It is formed into a bar shape. SPC as the original plate
C (cold rolled steel plate), Bs, SUS (stainless steel material), etc. can be used, and SUS having a particularly high yield strength is suitable. It is desirable that the plate thickness of the support member 26 be set to 1.6 mm or more to ensure rigidity, and especially 2.0 m.
About m is desirable.

The support member 26 comprises a seat portion 22 to which the base end of the blade 32 is fixed, and a first side wall portion 24 and a second side wall portion 20 which are substantially perpendicular to the seat portion 22. The seat portion 22 is formed in a rectangular flat plate shape, and the edges on both sides extending in the longitudinal direction are formed in a posture parallel to the rotation axis O of the toner carrier 18, that is, the seat portion 22 and the side wall portions 24, 20. Hopper 1 with the ridge of the corner parallel to the axis of rotation O
It is fixed at 2. The outer wall surface of the seat portion 22 on the side opposite to the hopper is formed to have a flatness of 0.1 mm or less. The first side wall portion 24 extends from the edge of the seat portion 22 near the toner carrier 18 in a direction substantially perpendicular to the seat portion 22.
The second side wall portion 20 is a seat portion 22 located far from the toner carrier 18.
Extends substantially perpendicular to the seat portion 22 in the opposite direction to the first side wall portion 24.

FIG. 5 is a schematic view showing one step of the method of manufacturing the developing device according to the first embodiment of the present invention. Support member 26
Is manufactured by pressing and shearing the steel sheet into a predetermined elongated shape, and then forming the steel sheet into a Z-shaped cross section by performing V bending twice using a die 104 and a punch 100 as shown in FIG. Cross-sectional shape of support member 26 and seat portion 2
There is the following correlation with the flatness of the outer wall surface on the side opposite to the hopper of No. 2.

FIG. 6 is a graph for explaining the flatness of the support member according to the first embodiment of the present invention. This graph represents the amount of warpage in the vicinity of the ridgeline when a SECC having a length of 260 mm, a width of 20 mm, and a plate thickness of 2 mm is bent into a L-shaped section or a Z-shaped section by press working. The measurement points P1 to P9 are arranged at equal intervals in the longitudinal direction from one end to the other end of the steel sheet. In this graph, when the surface to be measured becomes a concave surface by bending, the distance between the line segment whose both ends are located on the concave surface and the concave surface is represented as the amount of warpage. According to the experiment, when the SECC having the above dimensions is bent into an L-shaped cross section, the flatness is about 0.4 mm, and when the SECC having the above dimensions is bent into a Z-shaped cross section, the flatness is 0.
It will be less than 05 mm. As is clear from this, the flatness of the support member 26 is significantly smaller when the support member 26 is formed in the Z-shaped cross section than when formed in the L-shaped cross section.

Further, the first side wall portion 24 and the second side wall portion 20.
It is desirable to set the widths H ₁ and H ₂ of the steel sheet to 3 times or more the thickness of the steel sheet. Using the SECC of the above dimensions, the first side wall 2
4. The width H ₁ and H ₂ of the second side wall portion 20 is set to ₁ of the plate thickness of the steel plate.
As a result of an experiment in which the length was doubled, doubled, and tripled, the amount of warpage at the central portion (P5) in the longitudinal direction of the steel plate was as shown in the table below. still,
In the bending process in which the widths H ₁ and H ₂ of the first side wall part 24 and the second side wall part 20 are set to be 1 times the plate thickness of the steel plate, the steel plate is die 10
Since it could not be set to 4, the amount of warp could not be measured.

[Table 1]

As described above, according to the developing device of the first embodiment of the present invention, since the flatness of the seat portion 22 of the support member 26 to which the base end of the blade 32 is fixed can be reduced, the toner can be reduced. It is possible to improve the development quality by making the amount of toner attached to the carrier 18 uniform on the surface.

(Second Embodiment) FIG. 7 is a sectional view showing a developing device according to a second embodiment of the present invention. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. The second embodiment is different from the first embodiment in that the supporting member 56 to which the base end of the blade 32 is fixed has a U-shaped cross section, and is substantially the same as the first embodiment in other points. is there.

The support member 56 is composed of a seat portion 52 to which the base end of the blade 32 is fixed, and a first side wall portion 50 and a second side wall portion 54 which are substantially perpendicular to the seat portion 52. The seat portion 52 is formed in a rectangular flat plate shape, and the edges on both sides extending in the longitudinal direction are formed in a posture parallel to the rotation axis O of the toner carrier 18, that is, the seat portion 52 and the side wall portions 50 and 54. Hopper 1 with the ridge of the corner parallel to the axis of rotation O
It is fixed at 2. The flatness of the outer wall surface of the seat 52 is 0.
It is formed on a flat surface of 05 mm or less. On the inner wall surface of the seat portion 52, a streak-shaped beat 60 is formed as a recess. The beat 60 is formed along the side wall portions 50 and 54 at both edges of the inner wall surface of the seat portion 52 extending in the longitudinal direction.
The beat 60 is preferably formed in a groove having a rectangular cross section with a punch used for press molding described later, and its width is set to 1 to 2 mm and its depth is set to 0.2 to 0.3 mm. By forming such a beat 60 on the inner wall surface of the seat portion 52, the protrusion of the edge of the outer wall surface of the seat portion 52 is suppressed, and the flatness around the edge of the outer wall surface of the seat portion 52 extending in the longitudinal direction is further reduced. can do.

The first side wall portion 50 extends from the edge of the seat portion 52 near the toner carrier 18 in a direction substantially perpendicular to the seat portion 52. The second side wall portion 54 extends substantially in the same direction as the first side wall portion 50 from the edge of the seat portion 52 remote from the toner carrier 18 and substantially perpendicular to the seat portion 52. When the support member 56 is formed using the manufacturing method described later, the flatness of the outer wall surface of the seat portion 52 is determined by the side wall portions 50 and 54 with respect to the plate thickness t of the steel plate.
Of the widths H ₁ and H ₂ .

FIG. 8 is a graph for explaining the flatness of the support member according to the second embodiment of the present invention. This graph shows the sizes of the widths H ₁ and H ₂ of the side wall portion with respect to the plate thickness t of the steel sheet and the seat portion 52 when the manufacturing method described later is used.
Shows the relationship with the flatness of the outer wall surface. Side wall 50,
When the widths H ₁ and H _{2 of} 54 are not more than twice the thickness of the steel plate, the outer wall surface of the seat portion 52 is recessed at the center portion thereof, and the side wall portion 5 is formed.
When the widths H ₁ and H _{2 of 0} and 54 are three times or more the plate thickness of the steel plate, the central portion of the outer wall surface of the seat portion 52 is convexly warped.
When the widths H ₁ and H ₂ of the side wall portions 50 and 54 are 3 times or more and 5 times or less the thickness of the steel sheet, the flatness of the outer wall surface of the seat portion 52 is sufficiently smaller than 0.05 mm. The flatness of the outer wall surface of the seat portion 52 is preferably 0.05 mm or less so that the flatness of the tip of the blade 32 fixed to the outer wall surface of the seat portion is sufficiently small. The widths H ₁ and H ₂ are preferably 3 times or more the plate thickness of the steel sheet, and even if 5 times or more, sufficient flatness can be expected.

FIG. 9 is a schematic view showing one step of a method of manufacturing a developing device according to the second embodiment of the present invention. Support member 56
Is formed by press-shearing the steel sheet into a predetermined elongated shape and then by sinking and bending using dies 74 and 84 and a punch 70 as shown in FIG.

The side wall portions 50 and 54 are formed on the side wall surfaces 72 of the dies 74 and 84 by pressing the steel plate against the punch 70.
Folded along 86. At the bottom of the dies 74 and 84, a movable portion 80 having a flat and flat contact surface 78 with respect to the side wall surfaces 72 and 86 of the dies 74 and 84 is provided.
The movable portion 80 is provided so as to be capable of reciprocating along the side wall surfaces 72 and 86 of the dies 74 and 84. The movable portion 80 is pressed by a predetermined knockout force in a direction approaching the punch 70. Therefore, the outer wall surface of the seat portion 52 is formed flat along the contact surface 78 of the movable portion 80. Two elongated projections 76 and 82 are formed at the tip corner of the punch 70. The protrusions 76 and 82 have a height of 0.2 to 0.3 mm and a width of 1.
It is set to ~ 2 mm. The protrusions 76 and 82 are pressed against the steel plate when the steel plate is sunk and bent, and form the two lines of the beat 60 on the inner wall surface of the seat 52. By forming the beat 60 during the sinking and bending in this way, the corner portion of the outer wall surface of the seat portion 52 is suppressed from expanding outward, and the seat portion 52 is suppressed.
The flatness of the outer wall surface is further reduced. Further, as described above, the flatness of the outer wall surface of the seat portion 52 is set to 0.
It can be less than or equal to 05 mm.

As described above, according to the developing device of the second embodiment of the present invention, since the flatness of the seat portion 52 of the support member 56 to which the base end of the blade 32 is fixed can be reduced, the toner can be reduced. It is possible to improve the development quality by making the amount of toner attached to the carrier 18 uniform on the surface.

[Brief description of drawings]

FIG. 1 is a sectional view showing a developing device according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing conventional V-bending.

FIG. 3 is a perspective view showing a conventional steel plate bent by V-bending.

FIG. 4 is a perspective view showing a conventional steel plate bent into a U-shaped cross section by sinking.

FIG. 5 is a schematic view showing one step of the manufacturing method of the developing device according to the first embodiment of the present invention.

FIG. 6 is a graph illustrating the flatness of the support member according to the first embodiment of the present invention.

FIG. 7 is a sectional view showing a developing device according to a second embodiment of the present invention.

FIG. 8 is a graph illustrating the flatness of a support member according to a second embodiment of the present invention.

FIG. 9 is a schematic view showing one step of a manufacturing method of the developing device according to the second embodiment of the present invention.

[Explanation of symbols]

10 Development device 12 hoppers 14 Photoconductor 17 outer wall 18 Toner carrier 20 Second side wall 22 seat 24 First side wall 26 Support members 30 Contact part 32 blades 50 First side wall 52 seat 54 Second Side Wall 56 Support member 60 beats 70 punch 74 die 76 Projection 100 punches 104 die

Claims (11)

[Claims] 1. A toner carrier, which rotates by supporting toner on a cylindrical outer peripheral wall, a bar-shaped seat having a Z-shaped cross section formed by bending a steel plate having a plate thickness of 1.6 mm or more, and a flat plate-shaped seat portion, A first side wall portion extending from one edge of the seat portion extending in the longitudinal direction in a direction substantially perpendicular to the seat portion, and another edge extending in the longitudinal direction of the seat portion in a direction substantially opposite to the first side wall portion. A support member having a second side wall and a longitudinal axis parallel to the rotation axis of the toner carrier; and a base end fixed to the seat to rotate the toner carrier. And a blade for scraping off the toner carried by the toner carrier at a tip portion parallel to the axis. 2. The developing device according to claim 1, wherein the length of the first side wall portion and the second side wall portion in the lateral direction is three times or more the plate thickness of the steel sheet. 3. The developing device according to claim 1, wherein the steel plate is a cold-rolled steel plate that is galvanized. 4. The developing device according to claim 3, wherein the cold rolled steel sheet is a cold rolled stainless steel sheet. 5. A toner carrier which rotates by supporting toner on a cylindrical outer peripheral wall surface, a bar-shaped U-shaped bar-shaped section formed by bending a steel plate having a plate thickness of 1.6 mm or more, and a flat plate-shaped seat portion, The seat portion has side walls extending in a direction substantially perpendicular to the seat portion from both side edges extending in the longitudinal direction and having a lateral length of 3 times or more the plate thickness of the steel sheet, and the longitudinal axis is A supporting member provided in a posture parallel to the rotation axis of the toner carrier, and a base end portion of which is fixed to an outer wall surface of the seat portion, and the toner carrier body having a tip portion parallel to the rotation axis of the toner carrier. And a blade for scraping off the toner carried on the developing device. 6. The developing device according to claim 5, wherein the steel plate is a cold-rolled steel plate that has been galvanized. 7. The developing device according to claim 6, wherein the cold rolled steel sheet is a cold rolled stainless steel sheet. 8. A toner carrier that rotates by supporting toner on a cylindrical outer peripheral wall surface, and a flat seat portion, the longitudinal axis of which is provided in a posture parallel to the rotation axis of the toner carrier. Method for manufacturing a developing device, comprising: a rod-shaped support member; and a blade, the base end of which is fixed to the seat portion, and a blade which scrapes off the toner carried on the toner carrier at a tip parallel to the rotation axis of the toner carrier. And, by bending a steel plate having a plate thickness of 1.6 mm or more twice into a V shape to form a cross section of the steel plate into a Z shape,
A first side wall portion extending from one edge extending in the longitudinal direction of the seat portion in a direction substantially perpendicular to the seat portion, and another edge extending in the longitudinal direction of the seat portion in a direction substantially opposite to the first side wall portion. A method of manufacturing a developing device, comprising: forming the supporting member having a second side wall portion that extends. 9. The steel sheet is bent twice in a V-shape so that the lengths of the first side wall portion and the second side wall portion in the lateral direction are three times or more the plate thickness of the steel sheet. The method for manufacturing a developing device according to claim 8, wherein the cross section is formed in a Z shape. 10. A toner carrier, which rotates by supporting toner on a cylindrical outer peripheral wall surface, and a flat seat, and a longitudinal axis thereof is provided in a posture parallel to the rotation axis of the toner carrier. Method for manufacturing a developing device, comprising: a rod-shaped support member; and a blade, the base end of which is fixed to the seat portion, and a blade which scrapes off the toner carried on the toner carrier at a tip parallel to the rotation axis of the toner carrier. In addition, by subjecting a steel plate having a plate thickness of 1.6 mm or more to a sink bending process, the seat portion and the edges on both sides extending in the longitudinal direction of the seat portion extend in a direction substantially perpendicular to the seat portion. A method of manufacturing a developing device, comprising forming the supporting member having a side wall portion having a length in a direction that is three times or more the plate thickness of the steel sheet. 11. By subjecting the sunken bending process,
11. The method for manufacturing a developing device according to claim 10, wherein a streak-shaped recess is formed on the inner wall surface of the seat along the side wall.