JP2008076697A - Developing unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of components by attaching a toner restricting member to a housing directly without via a hold member and to form a uniform toner layer on the surface of a developing roller by restricting a quantity of toner attached to the surface of a developing roller, without precisely positioning the restricting member by laser length measurement or the like. <P>SOLUTION: Part of the housing 10 made of a synthetic resin is extended in a tangential direction of the developing roller 20. In addition, outside both ends of the extension part 12 in the axial direction of the developing roller 20, slits 13 are formed perpendicular to the axial direction. Between these slits, the extension part 12 has a free edge 12a. The sheet-like toner-restricting member 30 made of rubber or elastomer is directly attached to the extension part 12 between the slits 13. The entire face of one side of the sheet-like toner-restricting member 30 is supported by the extension part 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a developing device used in an image forming apparatus for forming a toner image. More specifically, the present invention relates to an improvement in a support structure for a toner regulating member that regulates the amount of toner adhering to the surface of the developing roller.

2. Description of the Related Art Conventionally, a synthetic resin housing (11) having a toner containing portion (12) containing toner, and the housing (11) is provided so as to be rotatable with respect to the image carrier of the image forming apparatus. Is provided between the developing roller (13), the developing roller (13), and the housing (11), and is in contact with the developing roller (13) over the entire length in the axial direction of the developing roller (13). And a toner regulating member (15) for regulating the amount of toner adhering to the surface of the developing roller (13). A part of the housing (11) extends in the tangential direction of the developing roller (13) and A developing device is known in which a recovery sheet (seal member) (19) is directly attached to the extended portion (Patent Document 1).
The toner regulating member (toner layer forming member) (15) in the developing device is entirely formed in a thin plate shape, the base end portion is fixed to the front surface portion of the housing (11), and the tip end portion is a developing roller. It is provided so that it can be pressed against the outer peripheral surface of (13) to form a thin layer having a predetermined thickness while charging the toner on the outer peripheral surface.

In such a developing device, the recovery sheet (seal member) (19) is brought into contact with the developing roller (13) in the forward direction of the rotation direction to prevent toner leakage from the surface of the developing roller. As long as it is possible, the contact pressure against the developing roller does not have to be very accurate.
Therefore, for example, as shown in Patent Document 1 and Patent Document 2, a part of the housing (11) extends in the tangential direction of the developing roller (13) and extends. The base of the recovery sheet (seal member) (19) is directly attached to the part, and the tip of the cantilevered seal member (19) is brought into contact with the developing roller (13) to easily form the seal part. Can do.

On the other hand, since the toner regulating member needs to regulate the amount of toner adhering to the surface of the developing roller and form a uniform toner layer on the surface of the developing roller, the contact pressure against the developing roller is managed with high accuracy. There is a need.
The toner regulating member (15) in Patent Document 1 is formed in a thin plate shape as a whole, its base end is fixed to the front surface of the housing (11), and the tip is the outer peripheral surface of the developing roller (13). Therefore, it is necessary to select the restricting member based on the plate thickness or to fix the restricting member (15) with high accuracy while performing precise positioning by laser length measurement. For this reason, there is a problem that complicated work increases and the cost increases (see paragraph 0002 of Patent Document 2).
Therefore, in Patent Document 2, it is proposed to hold the regulating member with a holding member and fix the regulating member to the housing via the holding member.

The paragraph 0024 of Patent Document 2 states that “the regulating member 15 can be directly bonded to the case without the holding member 18 to reduce the number of parts. Is fixed with a highly rigid holding member. ”, However, it is described that the regulation member is directly bonded to the case (housing) without the holding member. There is no disclosure of the specific configuration.
JP-A-8-220883 JP-A-8-160742

  The problem to be solved by the present invention is to reduce the number of parts by directly attaching the toner regulating member to the housing without using the holding member, and at the same time, without positioning the regulating member precisely by laser length measurement, etc. The object is to regulate the amount of toner adhering to the surface of the developing roller so that a uniform toner layer can be formed on the surface of the developing roller.

In order to solve the above problems, a developing device according to the present invention includes a synthetic resin housing having a toner containing portion containing toner,
A developing roller provided rotatably with respect to the housing and supplying toner to an image carrier of the image forming apparatus;
A developing device provided between the developing roller and the housing and provided with a toner regulating member that regulates the amount of toner adhering to the surface of the developing roller by contacting the developing roller over the entire axial length of the developing roller. A vessel,
A part of the housing extends in the tangential direction of the developing roller, and slits in a direction perpendicular to the axial direction are provided outside the both ends of the extending roller in the axial direction of the developing roller. A free end is formed in the extended portion, a sheet-like toner regulating member made of rubber or elastomer is directly attached to the extended portion between the slits, and the entire surface of one side of the sheet-like toner regulating member is formed by the extended portion. It is characterized by being supported.
According to such a configuration, since the toner regulating member is directly attached to the housing without using the holding member, the number of parts can be reduced.
In addition, a part of the housing is extended in the tangential direction of the developing roller, and slits in a direction perpendicular to the axial direction are provided outside the both ends of the developing roller in the axial direction of the extending roller. Since the free end is formed in the extended portion, the extended portion has a cantilever structure and has a spring property (flexibility).
Then, a sheet-like toner regulating member made of rubber or elastomer is directly attached to the extending portion, and the entire surface of one side of the sheet-like toner regulating member is supported by the extending portion. As long as the mounting part is accurately molded, the amount of toner adhering to the surface of the developing roller can be accurately regulated and evenly distributed on the surface of the developing roller without precise positioning of the toner regulating member by laser length measurement or the like. A precise toner layer can be formed with high accuracy.
That is, according to the present invention, the number of parts can be reduced by attaching the regulating member directly to the housing without using the holding member, and at the same time, the positioning of the developing roller can be performed without precise positioning of the regulating member by laser length measurement or the like. By regulating the amount of toner adhering to the surface, a uniform toner layer can be formed on the surface of the developing roller.

Preferably, the extending portion between the slits has a crown shape that curves convexly toward the developing roller with respect to the axial direction of the developing roller.
With this configuration, the pressure contact force between the developing roller and the toner regulating member, which tends to be low in the central portion of the developing roller due to the deflection of the shaft of the developing roller, can be corrected, and a uniform toner layer can be formed on the surface of the developing roller. It becomes like this.
Preferably, a plurality of reinforcing ribs extending in a direction perpendicular to the axial direction of the developing roller are provided in the extending portion between the slits along the axial direction of the developing roller, and the reinforcing rib in the axial direction of the developing roller is provided. The interval between the central portions is made smaller than the interval between the end portions.
With this configuration, the pressure contact force between the developing roller and the toner regulating member, which tends to be low in the central portion of the developing roller due to the deflection of the shaft of the developing roller, can be corrected, and a uniform toner layer can be formed on the surface of the developing roller. It becomes like this.
Desirably, the extending portion between the slits is provided with a plurality of holes in the axial direction of the developing roller within a range covered with the toner regulating member.
If comprised in this way, the thermal deformation regarding the axial direction of the developing roller of the extending part between the said slits can be relieved, and the fluctuation | variation by the temperature change of the toner layer formed in the developing roller surface can be reduced.

In order to solve the above problems, a developing device according to the present invention includes a synthetic resin housing having a toner containing portion containing toner,
A developing roller provided rotatably with respect to the housing and supplying toner to an image carrier of the image forming apparatus;
A developing device provided between the developing roller and the housing and provided with a toner regulating member that regulates the amount of toner adhering to the surface of the developing roller by contacting the developing roller over the entire axial length of the developing roller. A vessel,
A part of the housing extends in the tangential direction of the developing roller, and a toner restricting member made of rubber or elastomer is directly attached to the extending portion, and the toner restricting member is seen from the axial direction of the developing roller. A horizontal L-shape having an attachment base to the installation part and a cantilever part integral with the attachment base is provided, and the developing roller is brought into contact with the cantilever part.
According to such a configuration, since the toner regulating member is directly attached to the housing without using the holding member, the number of parts can be reduced.
Further, a part of the housing is extended in the tangential direction of the developing roller, and a toner regulating member made of rubber or elastomer is directly attached to the extending portion, and the toner regulating member is seen from the axial direction of the developing roller. Since it is comprised in the horizontal L shape which has the attachment base part to an extension part, and this cantilever part integral with this attachment base part, the cantilever part will have springiness (flexibility).
Since the developing roller is brought into contact with the cantilever portion, the laser restricting member and the toner restricting member itself in the extending portion integral with the housing can be molded with high accuracy. Even without precise positioning of the toner regulating member by length measurement or the like, it is possible to accurately regulate the amount of toner adhering to the surface of the developing roller and form a uniform toner layer on the surface of the developing roller with high accuracy. become.
That is, according to the present invention, the number of parts can be reduced by attaching the regulating member directly to the housing without using the holding member, and at the same time, the positioning of the developing roller can be performed without precise positioning of the regulating member by laser length measurement or the like. By regulating the amount of toner adhering to the surface, a uniform toner layer can be formed on the surface of the developing roller.

Preferably, the toner regulating member is provided so that a free end of the cantilever portion is positioned upstream of a contact portion between the cantilever portion and the developing roller with respect to the rotation direction of the developing roller.
With this configuration, it is possible to easily adjust the amount of toner supplied to the surface of the developing roller.
Desirably, the extending portion is provided with a plurality of holes in the axial direction of the developing roller within a range covered with the toner regulating member.
If comprised in this way, the thermal deformation regarding the axial direction of the developing roller of the said extension part can be relieved, and the fluctuation | variation by the temperature change of the toner layer formed in the developing roller surface can be reduced.

Hereinafter, embodiments of a developing device according to the present invention will be described with reference to the drawings.
1 is a cross-sectional view showing an embodiment of a developing device according to the present invention, FIG. 2A is a partially omitted plan view of FIG. 1, and FIG. 2B is a right side view of FIG. is there.
As shown in these drawings, the developing device 1 of this embodiment is provided with a synthetic resin housing 10 having a toner storage portion 11 in which toner T is stored, and a housing 10 that is rotatable with respect to the housing 10. A developing roller 20 that supplies toner to the image carrier 2 of the image forming apparatus, and is provided between the developing roller 20 and the housing 10, and the axial direction of the developing roller 20 (perpendicular to the paper surface of FIG. 1). A developing device including a toner regulating member that regulates the amount of toner adhering to the surface 21 of the developing roller 20 by contacting the developing roller 20 over its entire length;
A portion 12 of the housing 10 extends in the tangential direction of the developing roller 20 and extends outward from both ends of the extending roller 12 in the axial direction of the developing roller 20 (see FIG. 2A). ) In the left-right direction), free ends 12a are formed between the slits 13 between the slits 13, and a sheet-like toner regulating member 30 made of rubber or elastomer is extended between the slits 13. The mounting portion 12 is directly attached, and the entire surface of one side 32 of the sheet-like toner regulating member 30 is supported by the extending portion 12.

The developing roller 20 is made of rubber or metal. As shown in FIG. 2, the shaft 22 is rotatably supported on the side plate 14 of the housing 10, and a gear 23 provided at the end of the shaft 22 is not shown. It is rotationally driven by meshing with the drive gear of the forming apparatus main body.
In FIG. 1, reference numeral 24 denotes a supply roller made of sponge or the like, and its shaft 25 is rotatably supported on the side plate 14 of the housing 10, and a gear (not shown) provided at the end of the shaft is imaged like the developing roller. It is rotationally driven by meshing with the drive gear of the forming apparatus main body. The supply roller 24 is in contact with the developing roller 20 to supply the toner T in the toner storage unit 11 to the surface 21 of the developing roller 20.

The toner regulating member 30 is a sheet-like or thin plate-like member made of rubber or elastomer, and itself has elasticity in the thickness direction. The entire surface of the toner regulating member 30 (the surface facing the extended portion 12) 32 is attached to the extended portion 12 with an adhesive or a double-sided tape.
The toner regulating member 30 is in pressure contact with the developing roller 20 by its own elasticity and the elasticity (flexibility) of the extending portion 12, and the pressure contacting portion between the surface 31 of the toner regulating member 30 and the surface 21 of the developing roller 20. (Nip part) By regulating the amount of toner passing through N, the amount of toner adhering to the surface 21 of the developing roller 20 is regulated, and the toner supplied to the image carrier (photoconductor) 2 by the developing roller 20 Regulate the amount of
In FIG. 1, reference numerals 50 and 51 denote seal members that prevent the toner from leaking between the housing 10 and the developing roller 20. The sheet-like seal member 50 is connected to the developing roller by the sponge-like seal member 51. 20 is in pressure contact.

According to the developing device 1 as described above, since the toner regulating member 30 is directly attached to the housing 10 without using the holding member, the number of parts can be reduced.
Further, a part 12 of the housing 10 is extended in the tangential direction of the developing roller 20, and slits 13 in a direction orthogonal to the axial direction are provided outside the both ends of the extending roller 12 in the axial direction of the developing roller 20. Since the free end 12 a is formed in the extended portion 12 between the slits 13, the extended portion 12 has a cantilever structure and has a spring property (flexibility).
Then, a sheet-like toner regulating member 30 made of rubber or elastomer is directly attached to the extending portion 12, and the entire surface of one side 32 of the sheet-like toner regulating member 30 is supported by the extending portion 12. As long as the extended portion 12 integrated with the toner 10 is accurately molded, the amount of toner adhering to the surface 21 of the developing roller 20 can be reduced without precise positioning of the toner regulating member 30 by laser length measurement or the like. It becomes possible to accurately form a uniform toner layer on the developing roller surface 21 by regulating with high accuracy.
For example, the housing 10 is molded from polystyrene, the free length (the length of the slit 13) L = 15.6 mm, the displacement (the amount of deflection of the free end 12a) δ = 1.35 mm, the width (the length between the slits 13) When W = 305 mm and the total load (the contact force of the toner regulating member 30 against the developing roller 20) F = 10N, the thickness t of the extending portion 12 may be t = 0.72 mm.
As described above, according to the developing device 1, the number of parts can be reduced by attaching the regulating member 30 directly to the housing 10 without using a holding member, and at the same time, precise positioning of the regulating member 30 by laser length measurement or the like can be performed. Even if this is not the case, the amount of toner adhering to the surface 21 of the developing roller 20 can be regulated, and a uniform toner layer can be formed on the developing roller surface 21.

FIG. 3 is a diagram showing a comparative example, and (a) and (b) respectively correspond to FIGS. 2 (a) and 2 (b).
As shown in this comparative example, when the toner regulating member 30 is attached to the extended portion 12 ′ without providing a slit in the extended portion 12 ′, both ends of the extended portion 12 ′ are restrained by the side plate 14 of the housing 10. Therefore, as shown by the broken line 12 ″ in contact with the developing roller 20, the central portion bends in a curved shape so as to be separated from the developing roller 20, and the toner regulating member 30 is formed on the surface 21 of the developing roller 20. The amount of the toner adhering to the toner cannot be regulated to form a uniform toner layer on the developing roller surface 21.
On the other hand, in the above-described embodiment, as described above, the slits 13 in the direction orthogonal to the axial direction are provided outside the both ends in the axial direction of the developing roller 20 in the extending portion 12, and the slits 13 are arranged between the slits 13. Since the free end 12 a is formed in the extended portion 12, both ends in the axial direction of the extended portion 12 are not restrained by the side plate 14 of the housing 10 and are curved so that the central portion is separated from the developing roller 20. No longer bends.

FIG. 4 is a diagram showing a modification, and corresponds to FIG.
As shown in FIG. 4, the extending portion 12 between the slits 13 can have a crown shape that curves convexly toward the developing roller 20 in the axial direction of the developing roller 20.
With this configuration, it is possible to correct the pressure contact force between the developing roller 20 and the toner regulating member 30 that tends to be low in the central portion of the developing roller due to the bending of the shaft 22 of the developing roller 20, and a uniform toner layer is formed on the developing roller surface 21. Can be formed.

FIG. 5 is a diagram showing another modified example, and (a) and (b) correspond to FIGS. 2 (a) and 2 (b).
As shown in FIG. 5, the extending portion 12 between the slits 13 has reinforcing ribs 12 b extending in a direction orthogonal to the axial direction of the developing roller 20 (left and right direction in FIG. 5A) in the axial direction of the developing roller 20. And the interval between the reinforcing ribs in the axial direction of the developing roller 20 is made smaller at the center interval P2 than at the end interval P1.
With this configuration, it is possible to correct the pressure contact force between the developing roller 20 and the toner regulating member 30 that tends to be low in the central portion of the developing roller due to the bending of the shaft 22 of the developing roller 20, and a uniform toner layer is formed on the developing roller surface 21. Can be formed.

FIG. 6 is a view showing still another modified example, and (a) and (b) are plan views of the extending portion 12, respectively.
As shown in FIG. 6, the extending portion 12 between the slits 13 is provided with a plurality of holes (12 c or 12 d) in the axial direction of the developing roller 20 within the range covered with the toner regulating member 30. The shape of the hole may be a slit shape (rectangular shape) as shown in FIG. 1A, or a round hole as shown in FIG.
With this configuration, thermal deformation in the axial direction of the developing roller 20 of the extending portion 12 between the slits 13 can be mitigated, and fluctuation due to temperature change of the toner layer formed on the developing roller surface 21 can be reduced. Can do.

7 is a sectional view showing another embodiment of the developing device according to the present invention, FIG. 8A is a partially enlarged view of FIG. 7, and FIG. 8B is a view showing a comparative example.
As shown in these drawings, the developing device 1 ′ of this embodiment is provided with a synthetic resin housing 10 having a toner containing portion 11 containing toner T, and rotatable relative to the housing 10. , A developing roller 20 for supplying toner to the image carrier 2 of the image forming apparatus, and provided between the developing roller 20 and the housing 10, and an axial direction of the developing roller 20 (a direction orthogonal to the paper surface of FIG. 1). A developing device including a toner regulating member that regulates the amount of toner adhering to the surface 21 of the developing roller 20 by contacting the developing roller 20 over its entire length;
A part of the housing 10 extends in the tangential direction of the developing roller 20, and a toner regulating member 40 made of rubber or elastomer is directly attached to the extending portion 15, and the toner regulating member 40 is viewed from the axial direction of the developing roller 20. A lateral L-shape having an attachment base 41 to the extended portion 15 and a cantilever portion 42 integral with the attachment base 41, and the developing roller 20 is brought into contact with the cantilever portion 42. Features.

This embodiment differs from the above-described embodiment in that the slit 13 is not provided in forming the extended portion 15 and the toner regulating member 40 is configured as described above. The point remains the same.
However, in this embodiment as well, the free end 12a may be formed by providing the slit 13 in the extended portion 15 as in the above-described embodiment.
The toner restricting member 40 can be attached to the extended portion by closely fitting the base portion 41 into the concave portion 16 provided on the upper surface of the extended portion, or can be attached by being attached as in the above embodiment. it can.

Even with such a developing device 1 ′, the toner regulating member 40 is directly attached to the housing 10 without using a holding member, so that the number of parts can be reduced.
Further, a part 15 of the housing 10 is extended in the tangential direction of the developing roller 20, and a toner regulating member 40 made of rubber or elastomer having elasticity in the thickness direction is directly attached to the extended part 15, Since the toner restricting member 40 is configured in a lateral L shape having an attachment base 41 to the extending portion 15 as viewed from the axial direction of the developing roller 20 and a cantilever portion 42 integral with the attachment base 41, The cantilever part 42 will have springiness (flexibility).
Since the developing roller 20 is in contact with the cantilever portion 42, the mounting portion 16 of the toner restricting member 40 and the toner restricting member 40 itself in the extended portion 15 integral with the housing 10 are molded with high accuracy. As long as the toner regulating member 40 is not precisely positioned by laser length measurement or the like, the amount of toner adhering to the surface 21 of the developing roller 20 is accurately regulated and a uniform toner layer is formed on the developing roller surface 21. Can be formed with high accuracy.
That is, also in this embodiment, the number of parts can be reduced by attaching the regulating member 40 directly to the housing 10 without using the holding member, and at the same time, the regulating member 40 can be positioned without laser positioning. , The amount of toner adhering to the surface 21 of the developing roller is regulated, and a uniform toner layer can be formed on the surface 21 of the developing roller.

As shown in FIG. 8B, the toner regulating member 40 has a contact portion (nip) between the cantilever portion 42 and the developing roller 20 with respect to the rotation direction of the developing roller 20. Part) Although it is possible to provide it so as to be located downstream from N, it is preferable that the free end 43 of the cantilever part 42 be related to the rotation direction of the developing roller 20 as shown in FIG. It is provided so as to be located on the upstream side of the contact portion N between the cantilever portion 42 and the developing roller 20.
The distance S from the nip portion N to the tip of the toner regulating member 40 located upstream in the rotation direction of the developing roller 20 affects the amount of toner supplied to the surface 21 of the developing roller 20, and the longer S is, the more the toner is supplied. The amount gets bigger. Normally, it is desirable to set S to about 1 mm. Therefore, as shown in FIG. 8A, the free end 43 of the cantilever 42 is related to the rotation direction of the developing roller 20, and the cantilever 42 and the developing roller. By providing it so as to be located on the upstream side of the contact portion N with 20, it becomes possible to easily adjust the amount of toner supplied to the developing roller surface 21.
Although it is possible to reduce the amount of toner supplied to the surface of the developing roller by increasing the rigidity of the toner regulating member 40 itself, it is not desirable because the toner is pressed more than necessary.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be appropriately modified within the scope of the gist of the present invention. Further, the configurations shown in the drawings can be combined as appropriate.
For example, the extended portion 15 shown in FIG. 7 may be provided with a plurality of holes similar to those shown in FIG. 6 in the axial direction of the developing roller within the range covered with the toner regulating member 40.
If comprised in this way, the thermal deformation regarding the axial direction of the developing roller of the extension part 15 can be relieved, and the fluctuation | variation by the temperature change of the toner layer formed in the developing roller surface can be reduced.

FIG. 3 is a cross-sectional view showing an embodiment of a developing device according to the present invention. (A) is a partially omitted plan view of FIG. 1, (b) is a right side view of (a). It is a figure which shows a comparative example, (a) (b) is a figure corresponding to FIG. 2 (a) (b), respectively. It is a figure which shows a modification, and is a figure corresponding to FIG.2 (b). FIGS. 8A and 8B are diagrams showing another modification, and FIGS. 2A and 2B correspond to FIGS. Furthermore, it is a figure which shows another modification, (a) (b) is a top view of the extension part 12, respectively. Sectional drawing which shows other embodiment of the developing device which concerns on this invention. (A) is the elements on larger scale of FIG. 7, (b) is a figure which shows a comparative example.

Explanation of symbols

  T: toner, 1: developing device, 2: photoconductor (image carrier), 10: housing, 11: toner accommodating portion, 12, 15: extended portion, 12a: free end, 12b: reinforcing rib, 12c, 12d : Hole, 13: Slit, 20: Developing roller, 21: Surface, 30, 40: Toner regulating member, 41: Base part, 42: Cantilever part.

Claims (7)

A synthetic resin housing having a toner containing portion containing toner;
A developing roller provided rotatably with respect to the housing and supplying toner to an image carrier of the image forming apparatus;
A developing device provided between the developing roller and the housing and provided with a toner regulating member that regulates the amount of toner adhering to the surface of the developing roller by contacting the developing roller over the entire axial length of the developing roller. A vessel,
A part of the housing extends in the tangential direction of the developing roller, and slits in a direction perpendicular to the axial direction are provided outside the both ends of the extending roller in the axial direction of the developing roller. A free end is formed in the extended portion, a sheet-like toner regulating member made of rubber or elastomer is directly attached to the extended portion between the slits, and the entire surface of one side of the sheet-like toner regulating member is formed by the extended portion. A developing device characterized by being supported.   The developing device according to claim 1, wherein the extending portion between the slits has a crown shape that curves convexly toward the developing roller with respect to the axial direction of the developing roller.   The extending portion between the slits is provided with a plurality of reinforcing ribs extending in the direction orthogonal to the axial direction of the developing roller along the axial direction of the developing roller, and the interval between the reinforcing ribs in the axial direction of the developing roller is set. 3. A developing device according to claim 1, wherein the distance between the central portions is smaller than the distance between the end portions.   The extended portion between the slits is provided with a plurality of holes in the axial direction of the developing roller within a range covered by the toner regulating member. The developing device according to item. A synthetic resin housing having a toner containing portion containing toner;
A developing roller provided rotatably with respect to the housing and supplying toner to an image carrier of the image forming apparatus;
A developing device provided between the developing roller and the housing and provided with a toner regulating member that regulates the amount of toner adhering to the surface of the developing roller by contacting the developing roller over the entire axial length of the developing roller. A vessel,
A part of the housing extends in the tangential direction of the developing roller, and a toner restricting member made of rubber or elastomer is directly attached to the extending portion, and the toner restricting member is seen from the axial direction of the developing roller. A developing device having a lateral L-shape having a mounting base to a mounting portion and a cantilever portion integral with the mounting base, wherein the developing roller is in contact with the cantilever portion.   The toner restricting member is provided such that a free end of the cantilever portion is positioned upstream of a contact portion between the cantilever portion and the developing roller with respect to a rotation direction of the developing roller. The developing device according to claim 5.   7. The developing device according to claim 5, wherein a plurality of holes are provided in the extended portion in the axial direction of the developing roller within a range covered with the toner regulating member.

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