JP2016012105A - Development device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developer that can suppress increase of friction between an end of a blade rubber part and a developing roller.SOLUTION: The developer includes: a housing 50 containing a developing agent; a developing roller 31 adapted to be rotatable and carry the developing agent; a layer thickness regulating blade 100 having a blade body 110 and a blade rubber part 120 protruding from the blade body 110 by a first protrusion amount for regulating the thickness of the developing agent on the developing roller 31; and a side seal 200 arranged between the blade body 110 and an end of the developing roller 31 in an axis direction, blade rubber part 120 being in contact with the developing roller 31, an end surface of the side seal 200 on the inner side of the axis direction being in contact with the blade rubber part 120, the layer thickness regulating blade 100 further including a protrusion part 130 on a downstream side of the developing roller 31 in a rotational direction of the developing roller 31, the protrusion part 130 being nearer to the developing roller than the blade rubber part 120 is, protruding from the blade body 110 by a second protrusion amount more than the first protrusion amount, and being in contact with the end surface of the side seal 200.

Description

  The present invention relates to a developing device including a layer thickness regulating blade having a blade rubber portion that comes into contact with a developing roller, and a seal member whose end face comes into contact with the blade rubber portion.

  2. Description of the Related Art Conventionally, a developing device provided in an image forming apparatus includes a developing roller, a layer thickness regulating blade that regulates the thickness of a developer layer on the developing roller, and a casing that supports these members and accommodates the developer. And a seal member disposed between both ends of the developing roller and the housing.

  For example, in the developing device disclosed in Patent Document 1, a seal member is also provided between the layer thickness regulating blade and the developing roller in order to prevent the developer from leaking through the gap between the seal member and the layer thickness regulating blade. Yes. Specifically, the layer thickness regulating blade has a plate-like blade body and a blade rubber portion provided on the blade body and in contact with the developing roller. The seal member is affixed to the blade body so that the inner end surface in the axial direction of the developing roller is in contact with the blade rubber portion.

JP 2007-101595 A

  By the way, in the above-described technique, it is necessary to press the seal member against the blade rubber portion so that there is no gap between the blade rubber portion and the seal member. However, since the seal member is softer than the blade rubber portion, the blade rubber portion is sunk into the seal member. When the developing roller is used in this state, the toner is dammed up by the seal member at the upstream side in the rotation direction of the developing roller at the end of the blade rubber portion, and between the end of the blade rubber portion and the developing roller. It becomes difficult for the developer to enter. As a result, the friction generated between the end portion of the blade rubber portion and the developing roller becomes larger than the friction generated between the center portion of the blade rubber portion and the developing roller, and the vicinity of the end portion of the blade rubber portion becomes high temperature. There was a fear.

  Accordingly, an object of the present invention is to provide a developing device that can suppress an increase in friction between the end of the blade rubber portion and the developing roller.

In order to achieve the above-described object, a developing device of the present invention includes a housing that houses a developer, a developing roller that is rotatable and configured to carry the developer, and a developer on the developing roller. A layer thickness regulating blade configured to regulate the thickness, the blade body, and a layer thickness regulating blade having a blade rubber portion protruding from the blade body by a first protruding amount and contacting the developing roller, A sealing member disposed between the blade main body and the axial end of the developing roller, the end surface on the inner side in the axial direction being in contact with the blade rubber portion.
The layer thickness regulating blade is disposed downstream of the blade rubber portion in the rotation direction of the developing roller, protrudes from the blade body with a second protrusion amount equal to or greater than the first protrusion amount, and contacts the end surface of the seal member. Have

  According to the developing device configured as described above, when the seal member is pressed against the blade rubber portion, the seal member comes into contact with both the blade rubber portion and the protruding portion, so that the blade rubber portion is not easily embedded in the seal member. . This makes it easier for the developer to enter between the end portion of the blade rubber portion and the developing roller than when the end portion of the blade rubber portion is indented into the seal member. The friction between them can be reduced.

  In the developing device described above, the second protrusion amount may be larger than the first protrusion amount.

  In the developing device described above, the surface that contacts the end surface of the seal member of the protruding portion may be disposed at the same position as the surface that contacts the end surface of the seal member of the blade rubber portion in the axial direction.

  In the developing device described above, it is desirable that the protrusion has an inclined surface that is separated from the developing roller and extends along the peripheral surface of the developing roller and is inclined with respect to the blade body.

  According to this, the protrusion amount of the protrusion can be made as large as possible without the protrusion hitting the developing roller.

  In the developing device described above, it is desirable that the protruding portion is formed integrally with the blade rubber portion.

  According to this, compared with the case where a protrusion part is formed separately from a braid | blade rubber part, shaping | molding of a protrusion part is easy.

  In the developing device described above, when the side seal includes a contact member that contacts the developing roller and an elastic member that presses the contact member toward the developing roller, the axially inner side of the contact member It is desirable that both the end surface and the end surface on the inner side in the axial direction of the elastic member are in contact with the blade rubber portion and the protruding portion.

  According to this, since the end portion of the blade rubber portion does not sink into both the contact member and the elastic member, the friction between the end portion of the blade rubber portion and the developing roller can be reduced.

  According to the present invention, when the sealing member is pressed against the blade rubber portion, the sealing member contacts both the first surface of the blade rubber portion and the second surface of the protruding portion. It is hard to sink. This makes it easier for the developer to enter between the end portion of the blade rubber portion and the developing roller than when the end portion of the blade rubber portion is indented into the seal member. The friction between them can be reduced.

1 is a cross-sectional view illustrating a schematic configuration of a laser printer including a developing cartridge according to an embodiment of the present invention. It is sectional drawing of a process cartridge. FIG. 3 is an enlarged perspective view showing a structure around an opening of a developing cartridge. FIG. 3 is a cross-sectional view of the developing cartridge taken along a plane that passes through the side seal and is orthogonal to the axial direction of the developing roller. It is a figure which shows the edge part and side seal of a layer thickness control blade, Comprising: The figure (a) which shows the form which has a protrusion part, The figure (b) which shows the comparative example which does not have a protrusion part. FIG. 8 is an enlarged perspective view (a) showing a structure around the opening of the developing cartridge in a modified example, and a cross-sectional view (b) in which the layer thickness regulating blade is cut by a plane that passes through the protrusion and is orthogonal to the axial direction of the developing roller .

  Next, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, first, the overall configuration of a laser printer provided with a developing cartridge as an example of a developing device will be briefly described, and then the details of the features of the present invention will be described.

  Further, in the following description, the description will be made in the direction based on the user when the laser printer 1 is used. That is, the left side in FIG. 1 is “front”, the right side is “rear”, the back side is “left”, and the front side is “right”. Also, the vertical direction in FIG.

<Overall configuration of laser printer>
As shown in FIG. 1, the laser printer 1 includes a feeder unit 4 for feeding a sheet 3 into a main body casing 2, an image forming unit 5 for forming an image on the sheet 3, and the like.

  The feeder unit 4 includes a paper feed tray 6 that is detachably attached to the bottom of the main casing 2 and a paper pressing plate 7 provided in the paper feed tray 6. The feeder unit 4 includes various rollers 11 that carry the paper 3 and remove paper dust. In the feeder unit 4, the sheet 3 in the sheet feeding tray 6 is moved upward by the sheet pressing plate 7 and conveyed to the image forming unit 5 by various rollers 11.

  The image forming unit 5 includes a scanner unit 16, a process cartridge 17, a fixing unit 18, and the like.

  The scanner unit 16 is provided at an upper portion in the main body casing 2 and includes a laser light emitting unit (not shown), a polygon mirror 19 that is rotationally driven, lenses 20, 21 and reflecting mirrors 22, 23, 24, and the like. . In the scanner unit 16, the laser beam is irradiated on the surface of the photosensitive drum 27 by high-speed scanning through a path indicated by a chain line in the drawing.

  The process cartridge 17 is configured to be detachably attached to the main casing 2 by appropriately opening a front cover 2A provided on the front side of the main casing 2. The process cartridge 17 is mainly composed of a developing cartridge 28 and a drum unit 39.

  The developing cartridge 28 is detachably attached to the main casing 2 while being attached to the drum unit 39. As shown in FIG. 2, the developing cartridge 28 includes a developing roller 31, a layer thickness regulating blade 100, a supply roller 33, and a casing 50 that supports these members. The housing 50 has a toner storage chamber 34 in which toner as an example of a developer is stored.

  The layer thickness regulating blade 100 includes a blade body 110 and a blade rubber portion 120 fixed to the blade body 110.

The blade body 110 is a sheet metal extending in the left-right direction. The blade body 110 is fixed to the housing 50 above the developing roller 31, and the tip is disposed in front of the developing roller 31.
As shown in FIG. 3, the blade rubber portion 120 is a rubber member that is elongated in the left-right direction and smaller in size in the left-right direction than the blade body 110, and is made of, for example, silicon rubber or urethane rubber. The blade rubber portion 120 is provided on the surface on the developing roller 31 side at the tip of the blade body 110 and is in contact with the developing roller 31. The blade rubber portion 120 has a flat surface in contact with the developing roller 31 at the center in the left-right direction, and the upstream and downstream corners in the rotation direction of the developing roller 31 are arcuate in cross section. It has become.

  Returning to FIG. 2, in the developing cartridge 28, the toner stored in the toner storage chamber 34 is stirred by the agitator 34 </ b> A and then supplied to the developing roller 31 by the supply roller 33. At this time, the supply roller 33 and the developing roller 31 is triboelectrically charged. The toner carried on the outer peripheral surface of the developing roller 31 enters between the layer thickness regulating blade 100 and the developing roller 31 as the developing roller 31 rotates, and is further thinly layered with a constant thickness while being frictionally charged. Is carried on the developing roller 31.

  The drum unit 39 includes a photosensitive drum 27, a scorotron charger 29 and a transfer roller 30. In the drum unit 39, the surface of the photosensitive drum 27 is uniformly positively charged by the scorotron charger 29 and then exposed by high-speed scanning of the laser beam from the scanner unit 16. Thereby, the potential of the exposed part is lowered, and an electrostatic latent image based on the image data is formed.

  Next, by the rotation of the developing roller 31, the toner carried on the developing roller 31 is supplied to the electrostatic latent image formed on the surface of the photosensitive drum 27, so that the toner image is formed on the surface of the photosensitive drum 27. It is formed. Thereafter, the sheet 3 is conveyed between the photosensitive drum 27 and the transfer roller 30, whereby the toner image carried on the surface of the photosensitive drum 27 is transferred onto the sheet 3.

  As shown in FIG. 1, the fixing unit 18 includes a heating roller 41 and a pressure roller 42 that is disposed to face the heating roller 41 and pressurizes the heating roller 41. In the fixing unit 18 configured as described above, the toner transferred onto the paper 3 is thermally fixed while the paper 3 passes between the heating roller 41 and the pressure roller 42. The sheet 3 thermally fixed by the fixing unit 18 is conveyed to a paper discharge roller 45 disposed on the downstream side of the fixing unit 18, and is discharged from the paper discharge roller 45 onto a paper discharge tray 46.

<Detailed configuration of developing cartridge>
Next, the configuration of the developing cartridge 28 will be described in detail. FIG. 3 shows a state in which the developing roller 31 is removed from the housing 50. Further, since the configuration around the opening 51 of the developing cartridge 28 is substantially the same at the left end and the right end, only the left end is illustrated in the drawings referred to in the following description.

  As shown in FIG. 3, the housing 50 of the developing cartridge 28 has an opening 51 on the rear side wall, and the developing roller 31 is rotatably supported by the housing 50 so as to close the opening 51. Yes. A film 35 is provided on the lower edge of the opening 51, and side seals 200 as an example of a sealing member are provided on the left and right edges of the opening 51. A layer thickness regulating blade 100 is provided on the upper edge of the opening 51 so as to extend in the left-right direction.

  The side seal 200 is disposed in a shape following the outer peripheral shape of the developing roller 31 between the casing 50 and the developing roller 31 in the axial direction, that is, between both ends in the left-right direction, and is in contact with the developing roller 31. The film 35 is a sheet-like member extending in the left-right direction and is in contact with the lower part of the developing roller 31. In the layer thickness regulating blade 100, the blade rubber portion 120 is in contact with the developing roller 31 obliquely from above (see FIG. 2). As described above, in order to prevent the toner in the housing 50 from leaking from the periphery of the developing roller 31, the developing roller 31 is in close contact with the layer thickness regulating blade 100, the film 35, and the side seal 200 in four directions, top, bottom, left and right. ing. In the present embodiment, the developing roller 31 is provided so as to rotate in the direction of the arrow shown in FIG. 3, that is, the direction in which the peripheral surface slides from the bottom to the top of the side seal 200.

  The blade body 110 of the layer thickness regulating blade 100 extends to the outside in the left-right direction from the blade rubber portion 120, and a part of the side seal 200 is attached to a portion on the outside in the left-right direction from the blade rubber portion 120. Yes. That is, the layer thickness regulating blade 100 has the seal sticking surfaces 110 </ b> A on which part of the side seal 200 is provided on both the left and right sides of the blade rubber portion 120.

  The blade rubber portion 120 is provided with notches 121 formed so as to be recessed upward at both ends in the left-right direction. The blade main body 110 has a tip corresponding to the blade rubber portion 120.

  As shown in FIG. 5A, the notch 121 has a first side surface 121A extending upward from the lower end of the blade rubber portion 120 and an outer side in the left-right direction from the first side surface 121A. The second side surface 121B connected to the end surface 122 is formed. The second side surface 121 </ b> B is provided in a range in contact with the developing roller 31 of the blade rubber portion 120 (in a range indicated by dot hatching).

  By providing such a notch 121 in the blade rubber part 120, the surface of the blade rubber part 120 that contacts the developing roller 31 and the corner part of the second side surface 121B are developed at the left and right ends of the blade rubber part 120. It contacts the roller 31 (see FIG. 4). Thereby, at the position corresponding to the notch 121 of the developing roller 31, more toner is scraped off and the toner layer becomes thinner than the position inside the notch 121 in the left-right direction. It is possible to suppress toner leakage from the end portion of the toner.

  As shown in FIG. 3, in addition to the blade main body 110 and the blade rubber portion 120 described above, the layer thickness regulating blade 100 includes a protrusion 130 and a rubber plate on the surface of the blade main body 110 where the blade rubber portion 120 is provided. Part 140.

  The protruding portion 130 and the rubber plate portion 140 are arranged on the downstream side in the rotation direction of the developing roller 31 at both ends in the left-right direction of the blade rubber portion 120, that is, on the upper side.

  The protruding portion 130 and the rubber plate portion 140 are made of the same material as the blade rubber portion 120 and are formed integrally with the blade rubber portion 120. Thereby, compared with the case where the protrusion part 130 and the rubber plate part 140 are formed separately from the blade rubber part 120, the protrusion part 130 and the rubber plate part 140 can be easily formed.

  The protrusion 130 has a substantially triangular shape in a side view that tapers toward the rear, and protrudes toward the developing roller 31 from the seal application surface 110A of the blade body 110.

  Specifically, as shown in FIG. 4, the protruding portion 130 extends away from the seal application surface 110 </ b> A as it goes upward from a flat surface that contacts the developing roller 31 of the blade rubber portion 120, and is formed on the seal application surface 110 </ b> A. It has the 1st inclined surface 131 as an example of the inclined surface inclined with respect to it. The first inclined surface 131 extends along the peripheral surface of the developing roller 31. Moreover, the protrusion part 130 is arrange | positioned above the 1st inclined surface 131, and has the 2nd inclined surface 132 extended so that 110A of seal sticking surfaces may be approached as it goes upwards. In addition, the corner | angular part between the 1st inclined surface 131 and the 2nd inclined surface 132 is a curved surface. The protrusion 130 is separated from the developing roller 31.

  By forming the protrusion 130 in this manner, it is possible to increase the protrusion amount of the protrusion 130 as much as possible while suppressing the protrusion 130 from colliding with the developing roller 31.

  The protruding part 130 protrudes rearward from the blade rubber part 120. That is, the second protrusion amount that is the protrusion amount of the protrusion 130 from the seal attachment surface 110A is larger than the first protrusion amount that is the protrusion amount of the blade rubber portion 120 from the seal attachment surface 110A.

  As shown in FIG. 5A, the protruding portion 130 has an end surface 133 on the outer side in the left-right direction arranged at the same position as the end surface 122 on the outer side in the left-right direction of the blade rubber portion 120 in the left-right direction. That is, the end surface 133 on the outer side in the left-right direction of the protrusion 130 is flush with the end surface 122 on the outer side in the left-right direction of the blade rubber portion 120.

  As shown in FIG. 3, the rubber plate portion 140 is disposed on the inner side in the left-right direction of the protruding portion 130. The rubber plate portion 140 is formed in a rectangular plate shape, and the protruding amount from the seal sticking surface 110A of the blade body 110 is smaller than the protruding amount (first protruding amount) from the seal sticking surface 110A of the blade rubber portion 120. It has become.

  As shown in FIGS. 3 and 4, the side seal 200 is provided between the housing 50 and the left and right ends of the developing roller 31, and between the blade body 110 of the layer thickness regulating blade 100 and the left and right ends of the developing roller 31. Is provided. The side seal 200 overlaps the base material 210 attached to the housing 50, the blade side seal 220 attached to the blade body 110, the base material 210 and the blade side seal 220, and contacts the developing roller 31. And a contact member 230.

  The substrate 210 is made of a material having elasticity such as urethane sponge. The substrate 210 has a lower end disposed below the developing roller 31, an upper end disposed on the back side (front side) of the blade body 110 of the layer thickness regulating blade 100, and contacts the blade body 110 from the side opposite to the developing roller 31. doing. The base material 210 is affixed to the housing 50 with a double-sided tape or the like.

  The base member 210 is disposed between the contact member 230 and the housing 50, thereby pressing the contact member 230 toward the developing roller 31. Thereby, it is possible to prevent a gap between the contact member 230 and the developing roller 31.

  The blade-side seal 220 is an example of an elastic member, and is made of a material softer than the blade rubber portion 120, such as urethane sponge, and is formed in a rectangular shape. The blade side seal 220 is affixed to the seal affixing surface 110 </ b> A of the blade body 110. The blade side seal 220 overlaps the blade rubber portion 120 and the protruding portion 130 when viewed from the left-right direction.

  The blade-side seal 220 is disposed between the contact member 230 and the blade body 110 to press the contact member 230 toward the developing roller 31. Thereby, it is possible to prevent a gap between the contact member 230 and the developing roller 31.

  The contact member 230 is a fabric member that is softer than the blade rubber portion 120 and is formed in a substantially rectangular shape. The contact member 230 is made of, for example, a fabric member woven from Dyneema (manufactured by Toyobo Co., Ltd.) fiber. The contact member 230 is not limited to a woven member, and may be a non-woven fabric.

  The contact member 230 extends from a position overlapping the blade-side seal 220 to the rear side of the lower end of the base 210, and a part of the casing 50 that extends rearward from the blade-side seal 220, the base 210, and the base 210. It is affixed with double-sided tape. The contact member 230 overlaps the blade rubber portion 120 when viewed from the left-right direction. Further, the upper end of the contact member 230 is provided at a position above the contact portion of the blade rubber portion 120 with the developing roller 31, more specifically, in a position overlapping the protruding portion 130 when viewed from the left-right direction.

  As shown in FIG. 5A, the side seal 200 includes an end surface 221 on the inner side in the left-right direction of the blade-side seal 220 and an end surface 231 on the inner side in the left-right direction of the contact member 230. It is in contact with both the end surface 122 on the outer side in the direction and the end surface 133 on the outer side in the left-right direction of the protrusion 130.

  Next, a method of attaching the side seal 200 when assembling the developing cartridge 28 will be described with reference to FIGS. 4 and 5A.

  First, before assembling the layer thickness regulating blade 100 to the housing 50, the base material 210 is attached to the housing 50. Further, the blade side seal 220 is attached to the seal attaching surface 110A of the blade body 110. At this time, the blade side seal 220 is pressed against the blade rubber portion 120 and the protruding portion 130 so that there is no gap between the blade side seal 220 and the blade rubber portion 120 and the protruding portion 130. The end surface 221 is closely attached to the end surface 122 on the outer side in the left-right direction of the blade rubber portion 120 and the end surface 133 on the outer side in the left-right direction of the protruding portion 130, and in this state, the end surface 221 is attached to the seal application surface 110A.

  Next, the layer thickness regulating blade 100 is assembled to the casing 50, and the contact member 230 is affixed on the base member 210 and the blade side seal 220. At this time, the contact member 230 is pressed against the blade rubber portion 120 and the protruding portion 130 so that there is no gap between the contact member 230 and the blade rubber portion 120 and the protruding portion 130, and the end surface 231 on the inner side in the left-right direction of the contact member 230. Is adhered to the end surface 122 of the blade rubber portion 120 on the outer side in the left-right direction and the end surface 133 on the outer side of the protrusion portion 130 in the left-right direction.

  In this way, the blade side seal 220 and the contact member 230 are brought into contact with not only the blade rubber portion 120 but also the protruding portion 130 protruding from the blade rubber portion 120, whereby the blade side seal 220 and the blade rubber portion 120 are contacted. When pressed against the protruding portion 130, the pressure applied to the end surface 221 on the inner side in the left-right direction of the blade-side seal 220 and the end surface 231 on the inner side in the left-right direction of the contact member 230 is dispersed, and the blade-side seal 220 and the contact member 230 are deformed. Can be suppressed. Thereby, it is possible to suppress the end of the blade rubber portion 120 from being sunk into the blade side seal 220 and the contact member 230 by locally applying a force from the blade rubber portion 120 to the blade side seal 220 and the contact member 230.

  On the other hand, as shown in FIG. 5B, when the protrusion 130 is not provided as in this embodiment, the blade-side seal 220 is pressed against the blade rubber part 120 and the protrusion 130. A force is locally applied from the blade rubber portion 120 to the end surface 221 on the inner side in the left-right direction of the blade-side seal 220 and the end surface 231 on the inner side in the left-right direction of the contact member 230, so that the end of the blade rubber portion 120 The contact member 230 is recessed.

The operation and effect of the developing cartridge 28 configured as described above will be described.
When the developing roller 31 rotates, toner enters between the developing roller 31 and the blade rubber portion 120 of the layer thickness regulating blade 100. As described above, when the toner is interposed between the developing roller 31 and the blade rubber portion 120, the toner functions as a lubricant, and friction generated between the developing roller 31 and the blade rubber portion 120 is reduced.

  Incidentally, as shown in FIG. 5B, when the end of the blade rubber portion 120 is recessed into the side seal 200, the side seal 200 is located upstream of the blade rubber portion 120 in the rotation direction of the developing roller 31. The blade rubber portion 120 protrudes inward in the left-right direction from the end surface 122 on the outer side in the left-right direction, and the toner is blocked by the protruding portion 232. In this case, the toner does not easily enter between the end portion 120A of the blade rubber portion 120 that is indented into the side seal 200 and the developing roller 31, and between the end portion 120A of the blade rubber portion 120 and the developing roller 31. The generated friction is larger than the friction generated between the central portion of the blade rubber portion 120 where the toner is present and the developing roller 31.

  On the other hand, as shown in FIG. 5A, in this embodiment, since the end of the blade rubber portion 120 is difficult to sink into the side seal 200, the end of the blade rubber portion 120 sinks into the side seal 200. Compared with the case where the toner is present, the toner easily enters between the end of the blade rubber portion 120 and the developing roller 31. Thereby, friction generated between the end of the blade rubber portion 120 and the developing roller 31 can be reduced.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. About a concrete structure, it can change suitably in the range which does not deviate from the meaning of this invention. In the following description, components that are substantially the same as those in the above-described embodiment are given the same reference numerals, and descriptions thereof are omitted.

  In the embodiment, the protruding amount of the protruding portion 130 from the seal applying surface 110A is larger than the protruding amount of the blade rubber portion 120 from the seal applying surface 110A, but the shape of the protruding portion 130 is limited to this. It is not something. For example, as shown in FIGS. 6A and 6B, the protruding amount of the protruding portion 150 from the seal applying surface 110A may be equal to the protruding amount of the blade rubber portion 120 from the seal applying surface 110A. In other words, it is only necessary that a part of the contact member 230 overlaps the protruding portion 150 when viewed from the left-right direction.

  Specifically, the protrusion 150 is formed in a substantially rectangular shape when viewed from the side, and the first surface 151 that is flush with the surface of the blade rubber portion 120 that contacts the developing roller 31 faces upward from the blade rubber portion 120. It extends.

  In the embodiment, the laterally outer end surface 133 that contacts the blade-side seal 220 and the contact member 230 of the protruding portion 130 contacts the blade-side seal 220 and the contact member 230 of the blade rubber portion 120 in the left-right direction. Although provided at the same position as the outer end face 122, the position of the end face on the outer side in the left-right direction of the protruding portion is not limited to this. For example, the end surface on the outer side in the left-right direction of the protrusion may be provided, for example, 0.2 mm inward in the left-right direction with respect to the end surface 122 on the outer side in the left-right direction of the blade rubber portion 120.

  In the embodiment, the protrusion 130 is formed integrally with the blade rubber portion 120. However, the protrusion 130 may be formed separately from the blade rubber portion 120. The protrusion 130 may be made of a material different from that of the blade rubber part.

  In the above-described embodiment, the present invention is applied to the developing cartridge 28 provided in the laser printer 1. However, the present invention may be applied to other image forming apparatuses such as a developing apparatus provided in a copying machine or a multifunction peripheral.

  In the above embodiment, the present invention is applied to the developing cartridge 28, but the present invention is not limited to this. For example, the present invention may be applied to other developing devices such as a process cartridge in which a developing cartridge and a drum unit are integrated, or a developing device to which toner is supplied from a toner cartridge that contains toner.

28 Developing Cartridge 31 Developing Roller 100 Layer Thickness Restricting Blade 110 Blade Body 110A Sealing Surface 120 Blade Rubber Part 130 Projecting Part 131 First Inclined Surface 200 Side Seal 220 Blade Side Seal 230 Contact Member

Claims (6)

A housing for containing the developer;
A developing roller that is rotatable and configured to carry a developer;
A layer thickness regulating blade configured to regulate the thickness of the developer on the developing roller, the blade main body, and a blade rubber portion protruding from the blade main body by a first protruding amount and contacting the developing roller And a layer thickness regulating blade having,
A seal member disposed between the blade body and the axial end portion of the developing roller, the axially inner end surface being in contact with the blade rubber portion;
The layer thickness regulating blade is disposed downstream of the blade rubber portion in the rotation direction of the developing roller, protrudes from the blade body with a second protrusion amount equal to or greater than the first protrusion amount, and the end surface of the seal member A developing device having a projecting portion in contact therewith.   The developing device according to claim 1, wherein the second protrusion amount is larger than the first protrusion amount.   The surface of the protruding portion that contacts the end surface of the seal member is disposed at the same position as the surface of the blade rubber portion that contacts the end surface of the seal member in the axial direction. The developing device according to claim 1 or 2.   The said protrusion part is spaced apart from the said developing roller, and has the inclined surface inclined with respect to the said blade main body extended along the surrounding surface of the said developing roller. 4. The developing device according to any one of items 3.   The developing device according to claim 1, wherein the protruding portion is formed integrally with the blade rubber portion. The side seal has a contact member that contacts the developing roller, and an elastic member that presses the contact member toward the developing roller,
6. The axially inner end surface of the contact member and the axially inner end surface of the elastic member are both in contact with the blade rubber portion and the protruding portion. The developing device according to claim 1.

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