JP4385294B2 - Developing device, process cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to a developing device, a process cartridge, and an image forming apparatus.

In an image forming apparatus such as a laser printer, an electrostatic latent image is formed on the surface of a photosensitive drum, and a developer image is formed on the surface of the photosensitive drum by supplying developer from the developing device to the electrostatic latent image. Supported. Then, the developer image is transferred onto the paper, thereby forming an image on the paper.
The developing device includes a housing having an opening that opens toward the photosensitive drum, a developer carrier that carries the developer contained in the housing, and a developer layer that is carried on the developer carrier. And a blade for regulating the thickness. The developer carrier is rotatably supported in a state where a part of the surface is exposed at the opening of the housing. Further, the blade is formed in a thin plate shape extending along the axial direction of the developer carrier, and an upper end portion thereof is supported by the casing and a lower end portion thereof is pressed against the surface of the developer carrier. The developer in the housing is supplied onto the surface of the developer carrier, and passes between the blade and the surface of the developer carrier as the developer carrier rotates. A layer is carried on the surface of the developer carrying member. The developer carried on the surface of the developer carrying member is supplied to the electrostatic latent image formed on the surface of the photosensitive drum when contacting the surface of the photosensitive drum.

Such a developing apparatus is usually provided with a seal member for preventing toner from leaking from both longitudinal ends of the developer carrier. The seal member is disposed in the vicinity of both ends in the longitudinal direction of the developer carrier, and is pressed against the surfaces of both ends in the longitudinal direction of the developer carrier. For example, such a seal member is composed of an upstream seal member and a downstream seal member having different elasticity, and an upstream seal member having high elasticity is arranged on the upstream side in the rotation direction of the developer carrier, and elastic on the downstream side. It has been proposed to arrange a downstream sealing member having a small size (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 11-73017

However, in the configuration described in Patent Document 1, since the pressing force of the developer carrier by the downstream seal member is smaller than the pressing force of the developer carrier by the upstream seal member, the downstream seal member and the developer carrier are There is a problem that the developer leaks from the gap.
Therefore, an object of the present invention is to reliably prevent developer leakage from the gap between the pressing member and the housing in the opening of the housing by using the first seal member and the second seal member having different elasticity. It is an object of the present invention to provide a developing device capable of performing the above, a process cartridge including the developing device, and an image forming apparatus including such a developing device or the process cartridge.

In order to achieve the above object, according to a first aspect of the present invention, there is provided a developing device including: a housing having a longitudinal opening; and the opening disposed along the longitudinal direction of the opening. A developer carrier that is rotatably supported by the body; a pressing member that is disposed in the opening of the housing; and a first elastic modulus that is disposed in the opening of the housing, and the pressing member A first seal for preventing the developer from leaking from the gap between the pressing member and the casing in the opening portion, being sandwiched between the casing and the casing in a compressed state with a first compression amount A member and a second elastic modulus smaller than the first elastic modulus, disposed adjacent to the first seal member at the opening of the housing, and between the pressing member and the housing Compressed in a second compression amount larger than the first compression amount It is sandwiched, and a second sealing member for preventing leakage of the developer through the gap between the pressing member and the housing in the opening, the first seal member and the second sealing member are each Adjacent end portions are arranged to overlap in the compressing direction, and either the end portion of the first seal member or the end portion of the second seal member that overlaps is disposed on the first seal member and the second seal member. A plurality of projecting portions projecting in the direction adjacent to the seal member are formed .

According to such a configuration, since the first elastic modulus is larger than the second elastic modulus, and the first compressibility is smaller than the second compressibility, the first seal member serves as the pressing member and the casing. The difference between the pressing force and the force with which the second seal member presses the pressing member and the housing can be reduced. Therefore, the leakage of the developer from the gap between the pressing member and the housing at the opening of the housing can be reliably prevented by using the first seal member and the second seal member having different elasticity.
Further, since the protruding portion is formed at one of the end portion of the overlapping first seal member and the end portion of the second seal member, the pressing member presses the first seal member and the second seal member in the overlapping direction. The plurality of projecting portions deform along the shape of the end portions where the projecting portions are not formed, or the end portions where the projecting portions are not formed deform along the shape of the plurality of projecting portions. Thus, the first seal member and the second seal member can be connected without generating a gap. Therefore, the leakage of the developer from the connection portion between the first seal member and the second seal member can be reliably prevented.
In addition, when the first seal member and the second seal member are arranged, the end of the first seal member and the end of the second seal member can be allowed to overlap, so that the first seal member and the second seal member can be allowed to overlap. It is possible to reduce the labor required for the arrangement of the seal member.

According to a second aspect of the present invention, in the first aspect of the present invention, the first seal member and the second seal member are respectively pressed by the pressing member and the first compression amount and the second compression member, respectively. By compressing by the amount of compression, it has the same thickness in the opposing direction of the said housing | casing and the said press member, It is characterized by the above-mentioned.
According to such a configuration, since the first seal member and the second seal member have the same thickness, it is possible to prevent a step between the first seal member and the second seal member. Therefore, it is possible to prevent a gap from being generated between the first seal member or the second seal member and the pressing member or the housing. Therefore, the leakage of the developer from the gap between the pressing member and the housing in the opening of the housing can be more reliably prevented.

The invention according to claim 3 is the invention according to claim 1 or 2, wherein the pressing member is made of a hard material.
If the rigidity of the pressing member is low, a repulsive force from the first seal member having a large elastic modulus may cause a gap between the pressing member and the first seal member. However, according to this configuration, since the pressing member is made of a hard material, it is possible to prevent a gap from being generated between the pressing member and the first seal member, while the second sealing member is moved by the pressing member. It can be surely pressed. Therefore, the leakage of the developer from the gap between the pressing member and the housing in the opening of the housing can be prevented more reliably.

According to a fourth aspect of the present invention, there is provided the developer according to any one of the first to third aspects, wherein one end portion presses the developer carrying member and is carried on the developer carrying member. A blade unit for restricting the layer thickness, and the pressing member is the blade unit.
According to such a configuration, since the blade unit also serves as the pressing member, the number of parts can be reduced.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the casing communicates with the opening, and contains an accommodating portion for accommodating a developer, and the opening. A side portion located at both ends in the longitudinal direction and extending so as to face the developer carrier and the pressing member in a direction along a communication direction between the opening and the accommodating portion, and in a longitudinal direction of the opening A connecting portion that extends in the longitudinal direction of the opening and connects between the side portions located at both ends in the longitudinal direction at one end in a direction perpendicular to the communication direction. The seal member is disposed on the side portion, and the second seal member is disposed on the coupling portion.

  According to such a configuration, since the first seal member disposed on the side portion has great elasticity, the first seal member is moved from the developer carrier to the rotation of the developer carrier. Even when a large torque is applied, it is possible to prevent the adhesion between the first seal member and the developer carrying member from being lowered. Therefore, the leakage of the developer from both ends in the longitudinal direction of the developer carrier can be reliably prevented.

The invention according to claim 6 is the invention according to any one of claims 1 to 5 , wherein the second seal member is disposed between the housing and the first seal member. It is a feature.

  According to such a configuration, the end portion of the first seal member having a large elastic modulus is disposed on the end portion of the second seal member having a small elastic modulus, and these are pressed and sandwiched between the pressing member and the housing. Thus, the end portion of the second seal member having a small elastic modulus can be deformed along the shape of the end portion of the first seal member having a large elastic modulus. Therefore, it is possible to reliably prevent a gap from being generated in the connection portion between the first seal member and the second seal member, and to prevent the developer from leaking from the connection portion between the first seal member and the second seal member. It can be surely prevented.

The invention according to claim 7 is the invention according to any one of claims 1 to 6 , wherein at least one of the first seal member and the second seal member is a contact surface with the housing and the A concave portion and a convex portion are formed on at least one of the contact surfaces with the pressing member.
According to such a configuration, the pressing force by the pressing member is concentrated on the convex portion, and the adhesion between the convex portion and the housing or / and the pressing member can be enhanced. Therefore, the sealing performance between the pressing member and the housing can be improved, and the leakage of the developer from the gap between the pressing member and the housing in the opening of the housing can be more reliably prevented.

The invention according to claim 8 is characterized in that, in the invention according to claim 7 , the concave portion and the convex portion are formed in a linear shape.
According to such a configuration, it is possible to improve the adhesion between the first seal member or / and the second seal member and the housing or / and the pressing member in a region that is long in the extending direction of the concave portion and the convex portion. Therefore, the leakage of the developer from the gap between the pressing member and the housing in the opening of the housing can be prevented more reliably.

The invention according to claim 9 is characterized in that, in the invention according to claim 8 , the concave portion and the convex portion extend in a direction orthogonal to a direction connecting the inner side and the outer side of the opening. Yes.
According to such a configuration, the concave portion and the convex portion extend in the direction connecting the inner side and the outer side of the opening, that is, the direction orthogonal to the leakage direction of the developer, so that the leakage of the developer can be prevented more reliably. can do.

The invention according to claim 10 is the invention according to any one of claims 1 to 9 , wherein the first seal member is connected to be adjacent to the second seal member, and the housing is A dam member is provided to face the connecting portion between the first seal member and the second seal member from the inside of the opening, and to prevent leakage of the developer from the connecting portion. It is a feature.
According to such a configuration, the weir member can prevent the developer from entering the connecting portion between the first seal member and the second seal member. Therefore, the leakage of the developer from the connection portion between the first seal member and the second seal member can be prevented.

The invention according to claim 11 is characterized in that, in the invention according to any one of claims 1 to 10 , the developer is a polymerized toner obtained by polymerizing a polymerizable monomer. Yes.
According to such a configuration, even when a polymerized toner having good fluidity is used, leakage of the polymerized toner from the gap between the pressing member and the housing at the housing opening can be prevented.
According to a twelfth aspect of the present invention, in the developing device, a casing having a longitudinal opening, and the opening is disposed along the longitudinal direction of the opening, and is rotatably supported by the casing. A developer carrying member, a pressing member disposed in the opening of the housing, a first elastic modulus, disposed in the opening of the housing, and between the pressing member and the housing A first seal member that is sandwiched in a compressed state with a first compression amount and prevents leakage of developer from a gap between the pressing member and the housing in the opening; A second elastic modulus that is smaller than the elastic modulus of the first seal member, and is disposed adjacent to the first seal member in the opening of the housing, and the first compression between the pressing member and the housing. Is held in a compressed state with a second compression amount larger than the amount, A second seal member for preventing leakage of developer from a gap between the pressing member and the housing in the portion, and the first seal member is connected to be adjacent to the second seal member. The dam member is disposed so as to face the connecting portion between the first seal member and the second seal member from the inside of the opening, and prevents the developer from leaking from the connecting portion. It is characterized by having.
According to such a configuration, since the first elastic modulus is larger than the second elastic modulus, and the first compressibility is smaller than the second compressibility, the first seal member serves as the pressing member and the casing. The difference between the pressing force and the force with which the second seal member presses the pressing member and the housing can be reduced. Therefore, the leakage of the developer from the gap between the pressing member and the housing at the opening of the housing can be reliably prevented by using the first seal member and the second seal member having different elasticity.
Further, the weir member can prevent the developer from entering the connecting portion between the first seal member and the second seal member. Therefore, the leakage of the developer from the connection portion between the first seal member and the second seal member can be prevented.

According to a thirteenth aspect of the present invention, a process cartridge that is detachable from the image forming apparatus includes the developing device according to any one of the first to twelfth aspects.
According to such a configuration, since the developing device that can prevent the leakage of the developer from the gap between the pressing member and the housing in the opening of the housing is provided, the leakage of the developer from the developing device is prevented. Can be prevented.

The invention of claim 14 is the image forming apparatus is characterized in that it comprises a developing equipment according to any one of claims 1 to 12.
Prevention According to such a configuration, since the developing equipment which can prevent leakage of the developer through the gap between the pressing member and the casing at the opening of the housing, the leakage of the developing instrumentation placed these developer can do.
According to a fifteenth aspect of the present invention, in the image forming apparatus, the process cartridge according to the thirteenth aspect is provided.
According to such a configuration, since the process cartridge that can prevent the leakage of the developer from the gap between the pressing member and the housing in the opening of the housing is provided, the leakage of the developer from the process cartridge can be prevented. Can do.

According to the first aspect of the present invention, by using the first seal member and the second seal member having different elasticity, it is ensured that the developer leaks from the gap between the pressing member and the housing at the opening of the housing. Can be prevented.
Further, the first seal member and the second seal member can be connected without generating a gap, and the leakage of the developer from the connecting portion between the first seal member and the second seal member can be reliably prevented. it can. Moreover, the effort concerning arrangement | positioning of a 1st seal member and a 2nd seal member can be reduced.
According to the second aspect of the present invention, the leakage of the developer from the gap between the pressing member and the casing in the opening of the casing can be more reliably prevented.

According to the third aspect of the present invention, the leakage of the developer from the gap between the pressing member and the housing in the opening of the housing can be more reliably prevented.
According to the invention described in claim 4, since the blade unit also serves as the pressing member, the number of parts can be reduced.
According to the fifth aspect of the present invention, it is possible to reliably prevent developer leakage from both longitudinal ends of the developer carrying member.

According to invention of Claim 6 , it can prevent reliably that a clearance gap produces in the connection part of a 1st seal member and a 2nd seal member, and the connection of a 1st seal member and a 2nd seal member is possible. The leakage of the developer from the portion can be prevented more reliably.

According to the seventh aspect of the present invention, the sealing property between the pressing member and the housing can be improved, and the developer leaks from the gap between the pressing member and the housing in the opening of the housing. It can be surely prevented.
According to the eighth aspect of the present invention, the leakage of the developer from the gap between the pressing member and the casing in the opening of the casing can be more reliably prevented.

According to the ninth aspect of the present invention, the leakage of the developer can be prevented more reliably.
According to the tenth aspect of the present invention, it is possible to prevent the developer from leaking from the connecting portion between the first seal member and the second seal member.
According to the eleventh aspect of the present invention, it is possible to prevent the polymerized toner having good fluidity from leaking from the gap between the pressing member and the casing in the opening of the casing.
According to the twelfth aspect of the invention, the first seal member and the second seal member having different elasticity can be used to reliably prevent the developer from leaking from the gap between the pressing member and the case at the opening of the case. Can be prevented.

According to the invention described in 請 Motomeko 13, it is possible to prevent leakage of the developer from the developing device.
According to the invention described in claim 14, it is possible to prevent leakage of the developing instrumentation placed et the developer.
According to the invention of the fifteenth aspect, it is possible to prevent leakage of the developer from the process cartridge.

FIG. 1 is a cross-sectional side view of a main part showing an embodiment of a laser printer as an image forming apparatus of the present invention. In FIG. 1, a laser printer 1 includes a feeder unit 4 for feeding a sheet 3 and an image forming unit 5 for forming an image on the fed sheet 3 in a main body casing 2. .
An attachment / detachment opening 6 for attaching / detaching a process cartridge 18 to be described later is formed on one side wall of the main casing 2, and a front cover 7 for opening / closing the attachment / detachment opening 6 is provided. The front cover 7 is rotatably supported by a cover shaft (not shown) inserted through the lower end portion thereof. Thus, when the front cover 7 is closed around the cover axis, the attachment / detachment opening 6 is closed by the front cover 7, and when the front cover 7 is opened with the cover axis as a fulcrum (tilted), the attachment / detachment opening 6 is opened, The process cartridge 18 can be attached to and detached from the main casing 2 through the attachment / detachment opening 6. In addition, an operation panel (not shown) including operation keys and LED display units is embedded in the front cover 7.

Hereinafter, in the laser printer 1, the side on which the front cover 7 is provided is referred to as “front side”, and the opposite side is referred to as “rear side”.
The feeder unit 4 includes a paper feed tray 8 that is detachably attached to the bottom of the main casing 2, a paper feed roller 9 and a paper feed pad 10 that are provided above the front end of the paper feed tray 8, A pickup roller 11 provided on the rear side of the roller 9, a pinch roller 12 disposed oppositely on the lower front side of the paper feed roller 9, and a registration roller 13 provided on the upper rear side of the paper feed roller 9 are provided.

Inside the paper feed tray 8 is provided a paper pressing plate 14 on which the paper 3 can be placed in a stack. The paper pressing plate 14 is supported at the rear end so as to be swingable, so that the front end is movable in the vertical direction.
A lever 15 for lifting the front end portion of the paper pressing plate 14 upward is provided at the front end portion of the paper feed tray 8. The lever 15 is formed in a substantially L-shaped cross section so as to go from the front side to the lower side of the paper pressing plate 14, and its upper end is attached to a lever shaft 16 provided at the front end of the paper feed tray 8. The rear end portion is in contact with the front end portion of the lower surface of the paper pressing plate 14. Accordingly, when a clockwise rotational driving force in the drawing is input to the lever shaft 16, the lever 15 rotates about the lever shaft 16, and the rear end portion of the lever 15 lifts the front end portion of the paper pressing plate 14.

When the front end of the sheet pressing plate 14 is lifted, the uppermost sheet 3 on the sheet pressing plate 14 is pressed by the pickup roller 11, and the sheet feeding roller 9 and the sheet feeding pad 10 are rotated by the rotation of the pickup roller 11. Conveyance is started in between.
On the other hand, when the paper feed tray 8 is detached from the main casing 2, the front end portion of the paper pressing plate 14 moves downward due to its own weight, and is in a state along the bottom surface of the paper feed tray 8. In this state, the sheets 3 can be stacked on the sheet pressing plate 14.

The sheet 3 sent out between the sheet feeding roller 9 and the sheet feeding pad 10 by the pickup roller 11 is sandwiched between the sheet feeding roller 9 and the sheet feeding pad 10 by the rotation of the sheet feeding roller 9. Sometimes, each sheet is reliably fed and fed. The fed paper 3 passes between the paper feed roller 9 and the pinch roller 12 and is conveyed to the registration roller 13.
The registration roller 13 is composed of a pair of rollers facing each other, and after the registration of the sheet 3, the transfer position of the image forming unit 5 (a nip position between a photosensitive drum 28 and a transfer roller 30 described later, The toner image on the photosensitive drum 28 is conveyed toward the transfer position of the paper 3.

The image forming unit 5 includes a scanner unit 17, a process cartridge 18, a fixing unit 19, and the like.
The scanner unit 17 is provided in the upper part of the main casing 2 and includes a laser light source (not shown), a polygon mirror 20 that is rotationally driven, an fθ lens 21, a reflecting mirror 22, a lens 23, a reflecting mirror 24, and the like. The laser beam based on the image data emitted from the laser light source is deflected by the polygon mirror 20 as shown by a chain line, passes through the fθ lens 21, then the optical path is turned back by the reflecting mirror 22, and further passes through the lens 23. After that, the optical path is further bent downward by the reflecting mirror 24, so that the surface of a photosensitive drum 28 (to be described later) of the process cartridge 18 is irradiated at high speed.

The process cartridge 18 is detachably attached to the main body casing 2 below the scanner unit 17. The process cartridge 18 includes a drum cartridge 25 and a developing cartridge 26 as a developing device that is detachably attached to the drum cartridge 25.
Each of the drum cartridges 25 extends in the front-rear direction, and is between a pair of side plates 27 arranged to face each other in a direction orthogonal to the front-rear direction (a direction perpendicular to the paper surface in FIG. 1; hereinafter, simply referred to as “width direction”). A developing cartridge 26 is mounted on the front side, and a photosensitive drum 28, a scorotron charger 29, a transfer roller 30, and a cleaning brush 31 are provided on the rear side.

  The photosensitive drum 28 includes a cylindrical drum body 32 formed by a positively chargeable photosensitive layer whose outermost layer is made of polycarbonate or the like, and a metal extending along the longitudinal direction of the drum body 32 at the axis of the drum body 32. And a drum shaft 33 made of steel. The drum shaft 33 is non-rotatably supported on both side plates 27 of the drum cartridge 25, and the drum main body 32 is rotatably supported on the drum shaft 33, so that the photosensitive drum 28 is disposed between the both side plates 27. The shaft 33 is provided to be rotatable.

  The scorotron charger 29 is disposed oppositely and spaced apart from the rear side of the photosensitive drum 28 so as not to contact the photosensitive drum 28. The scorotron charger 29 is a positively charged scorotron charger that generates corona discharge from a charging wire such as tungsten, so that the surface of the photosensitive drum 28 can be uniformly charged to a positive polarity. Is provided.

  The transfer roller 30 is rotatably supported by both side plates 27 of the drum cartridge 25, and is disposed so as to face and contact the photosensitive drum 28 in the vertical direction so as to form a nip with the photosensitive drum 28. Yes. The transfer roller 30 is configured by covering a metal roller shaft 34 with a roller 35 made of a conductive rubber material. A transfer bias is applied to the transfer roller 30 during transfer.

The cleaning brush 31 is disposed behind the photosensitive drum 28 so that the tip of the brush is in contact with the surface of the drum body 32 of the photosensitive drum 28.
As shown in FIG. 2, the developing cartridge 26 includes a housing 36, a toner containing chamber 37, a supply roller 38, a developing roller 39 as a developer carrier, and a blade unit as a pressing member. 40.

The housing 36 is formed in a box shape having a longitudinal opening 41 at the rear end.
Specifically, as shown in FIGS. 2 and 3, the housing 36 includes an upper wall 42 and a lower wall 43 that face each other in the vertical direction, and a width direction between the upper wall 42 and the lower wall 43. A pair of side walls 44 provided so as to be closed from both sides, and a front wall 79 provided so as to close between the upper wall 42 and the lower wall 43 from the front side are provided.

  As shown in FIG. 2, the upper wall 42 is provided with a partition plate 45 that extends in the middle in the front-rear direction and extends toward the lower wall 43 from a portion closer to the rear side. The partition plate 45 partitions the internal space of the housing 36, and the front internal space is partitioned as a toner storage chamber 37. In addition, a blade attachment portion 46 as a connecting portion for attaching the blade unit 40 is provided at the rear end portion of the upper wall 42, and the blade attachment portion 46, the lower wall 43, and the pair of side walls 44, A longitudinal opening 41 extending in the width direction is defined. A direction in which the toner storage portion 37 and the opening 41 communicate with each other is referred to as a communication direction. That is, in the present embodiment, the communication direction and the front-rear direction coincide with each other.

  The blade mounting portion 46 has an L-shaped side section. Specifically, the blade attachment portion 46 faces the lower wall 43, extends in the width direction, and has a plate-like upper attachment portion 47 having a width in the front-rear direction, and downward from the front end portion of the upper attachment portion 47. And a front mounting portion 48 that extends in the width direction, has a width in the vertical direction, and is formed with a lattice-like recess when viewed from the back. The blade attachment portion 46 may be formed separately from the upper wall 42 and may be fixed to the upper wall 42, or may be formed integrally with the upper wall 42. If the blade mounting portion 46 is formed integrally with the upper wall 42, the number of parts of the laser printer 1 can be reduced, and the configuration can be simplified.

  As shown in FIG. 3, the front mounting portion 48 is formed with a recess 82 for avoiding a collision with an assembly screw 94, which will be described later, by notching in a semicircular shape from the lower end edge of both ends in the longitudinal direction. . Further, when the blade unit 40 is attached to the blade attachment portion 46 (the front attachment portion 48) at a position spaced apart from each recess 82 outward in the longitudinal direction, the attachment screw 100 described later is attached to the front attachment portion 48. A screw hole 83 for screwing is formed.

  As shown in FIG. 2, the front end portion of the lower wall 43 extends obliquely upward to the front side and is connected to the front wall 79. A film placement portion 121 extending along the axial direction of the developing roller 39 is formed on the rear upper surface of the lower wall 43. In the film placement portion 121, a lower film 122 made of polyethylene terephthalate and rubbed uniformly along the axial direction on the peripheral surface of the roller 56 of the developing roller 39 is placed. The lower film 122 is rubbed uniformly along the axial direction on the peripheral surface of the roller 56 of the developing roller 39 above the lower wall 43, so that the toner is between the lower wall 43 and the developing roller 39. Leakage can be prevented. Further, as shown in FIG. 3, a plurality of ribs 103 are formed on the lower surface of the lower wall 43 so as to extend in the front-rear direction at intervals in the width direction. The ribs 103 formed at both ends in the width direction of the lower surface of the lower wall 43 extend in the front-rear direction along the inner edge in the width direction of the lower surface 102 of the seal arrangement portion 96 described below, and a felt seal member described later. It also serves as a guide part for arranging 93.

As shown in FIG. 3, the side wall 44 has a support plate portion 95 for supporting the developing roller 39, and a side where a seal side portion 88 and a side seal 91 of a blade back seal 87 to be described later are disposed. And a seal arrangement part 96 as a part.
The support plate 95 has a plate shape extending in the vertical direction, and is formed with a bearing hole 97 for receiving a roller shaft 55 of the developing roller 39 described later. The bearing hole 97 has a U-shape when viewed from the side and has an opening at the rear end thereof so that the roller shaft 55 of the developing roller 39 can be received from the opening.

  The seal arrangement portion 96 is provided adjacent to the support plate portion 95 on the inner side in the longitudinal direction of the opening 41, and the axial end portion of the roller 56 of the developing roller 39 described later and the blade unit 40 described later. It has a roller facing surface 98 that faces the lower end of the leaf spring member 57 and extends in a curved shape along the outer peripheral surface of the roller 56. A recess 99 for receiving a roller shaft 53 of a supply roller 38, which will be described later, is formed in the middle of the seal arrangement portion 96 in the vertical direction so as to be recessed obliquely forward.

Further, as shown in FIG. 2, the front wall 79 is gripped when the developing cartridge 26 is attached to or detached from the drum cartridge 25 by extending forward from a connecting portion with the upper wall 42 and folding back further downward. A grip portion 49 is provided.
In the toner storage chamber 37 serving as a storage unit, positively chargeable non-magnetic one-component toner is stored as a developer. Examples of the toner include polymerizable monomers such as styrene monomers such as styrene, and acrylic monomers such as acrylic acid, alkyl (C1 to C4) acrylate, and alkyl (C1 to C4) methacrylate. Polymerized toners obtained by copolymerization by a known polymerization method such as suspension polymerization are used. Such a polymerized toner has a spherical shape, has extremely good fluidity, and can achieve high-quality image formation.

Such a toner is blended with a colorant such as carbon black, wax, and the like, and an external additive such as silica is added to improve fluidity. The particle diameter is about 6 to 10 μm.
An agitator 50 for agitating the toner in the toner storage chamber 37 is provided in the toner storage chamber 37. The agitator 50 is supported by a rotation shaft 51 extending in the width direction at the center of the toner storage chamber 37, and the toner in the toner storage chamber 37 is rotated by rotating the agitator 50 about the rotation shaft 51. Is agitated and discharged toward the rear side from the communication port 52 between the partition plate 45 and the lower wall 43.

The supply roller 38 is disposed obliquely below the rear side of the communication port 52 and is rotatably supported between the pair of side walls 44 of the housing 36. The supply roller 38 is configured by covering a metal roller shaft 53 with a roller 54 made of a conductive foam material.
The developing roller 39 is disposed behind the supply roller 38 along the width direction at the opening 41 and is rotatably supported between the support plate portions 95 of the pair of side walls 44 of the housing 36. . Further, the developing roller 39 is disposed so that a part of the surface of the developing roller 39 protrudes rearward from the opening 41 of the housing 36 and is exposed, and the developing roller 26 is attached to the drum cartridge 25 and the photosensitive drum 28. Contact in the front-rear direction. The developing roller 39 is configured by covering a metal roller shaft 55 with a roller 56 made of a conductive rubber material. In the roller 56 of the developing roller 39, the surface of a roller layer made of conductive urethane rubber or silicone rubber containing carbon fine particles is coated with a coating layer of urethane rubber or silicone rubber containing fluorine. Further, the roller 56 of the developing roller 39 is disposed in contact with the roller 54 of the supply roller 38 so as to be compressed with each other.

The supply roller 38 is rotated in the counterclockwise direction in which the portion in contact with the developing roller 39 rotates from top to bottom as indicated by an arrow. Further, as shown by the arrow, the developing roller 39 is rotated in the counterclockwise direction in which the portion exposed from the housing 36 rotates from top to bottom.
As shown in FIG. 4, FIG. 5, FIG. 6 or FIG. 7, the blade unit 40 includes a leaf spring member 57 as a blade, a bending preventing member 58 and a reinforcing plate 59 for supporting the leaf spring member 57, Two assembly screws 94 for fixing them together and a seal washer 84 are provided. Each member constituting the blade unit 40 is made of a metal as a hard material. The metal used here has at least higher hardness than a sponge seal member 92 described later. As will be described later, in the blade unit 40, the reinforcing plate 59 is opposed to the front mounting portion 48 with respect to the blade mounting portion 46 in a state where the leaf spring member 57 is sandwiched between the bending preventing member 58 and the reinforcing plate 59. It is attached to touch.

  The leaf spring member 57 is made of a thin metal leaf spring material, and is formed in a rectangular shape having substantially the same width as the axial width of the roller 56 of the developing roller 39. The upper end portion of the leaf spring member 57 is sandwiched between the bending prevention member 58 and the reinforcing plate 59. A pressing rubber member 60 having a rectangular cross section made of insulating silicone rubber is provided at the lower end of the leaf spring member 57 so as to extend in the longitudinal direction of the leaf spring member 57. The pressing rubber member 60 is not provided at both ends in the longitudinal direction of the leaf spring member 57, and is formed at both ends so that an upper end portion of a felt seal member 93 described later can be attached. .

  In addition, at both ends in the longitudinal direction of the leaf spring member 57, insertion holes (not shown) through which the assembly screws 94 are inserted are positioned in the thickness direction at positions opposed to a thread groove hole 80 described later in the front-rear direction. It is formed to penetrate. Each insertion hole is arranged inside the both end edges of the pressing rubber member 60 in the longitudinal direction of the leaf spring member 57. Further, in the longitudinal direction of the leaf spring member 57, attachment holes 81 for inserting attachment screws 100 described later are formed on both outer sides of each insertion hole so as to penetrate the thickness direction. Each attachment hole 81 is formed at a position corresponding to each screw hole 83 formed in the front attachment portion 48 of the blade attachment portion 46 in the front-rear direction.

  The bending preventing member 58 has an L-shaped side section, extends in the longitudinal direction of the leaf spring member 57, and is disposed to face the upper end portion of the surface of the leaf spring member 57. The bending prevention member 58 extends rearward from the upper edge of the contact portion 61 when the blade unit 40 is attached to the blade attachment portion 46 and the rectangular plate contact portion 61 that contacts the surface of the leaf spring member 57. The extending portion 62 and two gripping portions 63 extending downward from the rear end portion (the free end portion in the extending direction) of the extending portion 62 are integrally provided.

  The extending portion 62 is provided between the end extending portion 64 extending at a first width from both ends in the longitudinal direction of the upper end edge of the contact portion 61, and the upper end edge of the contact portion 61. A central extension portion 65 extending from the central portion in the longitudinal direction with a second width larger than the first width. In other words, the extending portion 62 extends rearward from the entire longitudinal direction of the upper end edge of the contact portion 61 and has notches 66 at both longitudinal ends.

The two gripping portions 63 respectively extend obliquely rearward and downward from both longitudinal ends of the central extending portion 65 with respect to the central extending portion 65, and are formed in a rectangular shape in a rear view.
Each assembly screw 94 is located at both ends in the longitudinal direction of the contact portion 61, at positions that oppose each end extending portion 64 in the vertical direction and that oppose the thread groove hole 80, which will be described later, in the front-rear direction. An insertion hole (not shown) to be inserted is formed so as to penetrate the thickness direction. Further, in the longitudinal direction of the contact portion 61, attachment holes 81 corresponding to the attachment holes 81 of the leaf spring member 57 are formed on both outer sides of the insertion holes so as to penetrate the thickness direction.

  The reinforcing plate 59 is made of an elongated rectangular metal plate, extends along the longitudinal direction of the leaf spring member 57, and is formed shorter than between the mounting holes 81 of the leaf spring member 57. The reinforcing plate 59 is opposed to the contact portion 61 of the bending prevention member 58 on the back surface of the leaf spring member 57 with the leaf spring member 57 interposed therebetween, and the lower end surface thereof faces the lower end surface of the contact portion 61 in the vertical direction. It is arranged at the position that becomes one. Further, the reinforcing plate 59 is formed to be slightly narrower than the width (vertical width) of the contact portion 61 of the bending preventing member 58. The reinforcing plate 59 further reinforces the leaf spring member 57 by supporting the upper end portion of the leaf spring member 57 between the reinforcement plate 59 and the bending preventing member 58. Further, at both ends in the longitudinal direction of the reinforcing plate 59, screw groove holes 80 into which the assembly screws 94 are screwed are formed.

  Each assembly screw 94 is integrally provided with a screw head 85 and a screw shaft 86 extending from the screw head 85. Each assembly screw 94 has the upper end portion of the leaf spring member 57 sandwiched between the bend preventing member 58 and the reinforcing plate 59, and the screw shaft 86 is connected to the bend preventing member 58 and the leaf spring from the bend preventing member 58 side. The screw 57 is inserted into insertion holes (not shown) formed at both ends in the longitudinal direction of the member 57, and the screw heads 85 are opposed to the contact portions 61, so that the screw grooves 80 formed at both ends of the reinforcing plate 59 are formed. By screwing, the leaf spring member 57 and the bending prevention member 58 and the reinforcing plate 59 sandwiching the leaf spring member 57 are fixed to each other.

The leaf spring member 57, the bending prevention member 58, and the reinforcing plate 59 are fixed to each other only by two assembly screws 94.
The seal washer 84 is made of a rubber material and is formed in an annular plate shape through which the screw shaft 86 of the assembly screw 94 can be inserted. In the assembly by the assembly screw 94 described above, the screw shaft 86 of the assembly screw 94 is inserted into the seal washer 84, and then the screw shaft 86 is inserted into the bending prevention member 58, the leaf spring member 57, and the reinforcing plate 59. The seal washer 84 is interposed between the screw head 85 of the assembly screw 94 and the contact portion 61 of the bending prevention member 58. By interposing this seal washer 84, it is possible to seal between the screw head 85 of the assembly screw 94 and the contact portion 61 of the bending preventing member 58, and between the screw shaft 86 and the screw groove hole 80. It is possible to prevent the toner that has entered the gap from leaking between the screw head 85 and the contact portion 61.

In the blade unit 40, as shown in FIG. 2, the extending portion 62 of the bending preventing member 58 is opposed to the blade mounting portion 46 with a gap from the upper mounting portion 47, and the reinforcing plate 59 is It is attached so as to be opposed to the front attachment portion 48.
In the attachment of the blade unit 40, as shown in FIG. 8, the attachment screw 100 is inserted into each attachment hole 81, and the attachment screw 100 is screwed into the screw hole 83 of the blade attachment portion 46, thereby providing the blade unit. 40 is fixed to the blade mounting portion 46.

  As shown in FIGS. 4 and 5, in each attachment hole 81 of the contact portion 61 and the leaf spring member 57, one attachment hole 81 is formed in a round hole corresponding to the outer diameter of the screw shaft of the attachment screw 100. The other mounting hole 81 is formed as a long hole that is slightly longer in the longitudinal direction of the contact portion 61, the leaf spring member 57, and the reinforcing plate 59. By forming one attachment hole 81 as a long hole, a tolerance can be given to the formation position of the attachment hole 81 in the longitudinal direction, and the blade unit 40 can be easily attached to the blade attachment portion 46.

Further, when the blade unit 40 is attached to the blade attachment portion 46, the tip end of the screw shaft 86 of the assembly screw 94 protruding from the reinforcing plate 59 enters the recess 82 of the front attachment portion 48. Collision between the portion and the front mounting portion 48 can be avoided. Therefore, the reinforcing plate 59 can be brought into contact with the front mounting portion 48 without a gap.
Further, in attaching the blade unit 40, the grip unit 63 can be gripped from the notch portion 66, and the blade unit 40 can be aligned with the blade mounting portion 46. Easy to install.

In a state where the blade unit 40 is attached to the blade attachment portion 46, the lower end portion of the leaf spring member 57 faces the roller 56 of the developing roller 39 from the front side, and the pressing rubber member 60 is elastic of the leaf spring member 57. It is pressed against the roller 56 by force.
The toner discharged from the communication port 52 to the rear inner space of the housing 36 by the rotation of the agitator 50 is supplied onto the roller 56 of the developing roller 39 by the rotation of the supply roller 38. At this time, the supply roller The friction roller is positively charged between the 38 rollers 54 and the roller 56 of the developing roller 39. The toner supplied onto the roller 56 of the developing roller 39 enters between the pressing rubber member 60 of the blade unit 40 and the roller 56 of the developing roller 39 with the rotation of the developing roller 39, and here further frictionally charged. As a result, a thin layer having a constant thickness is carried on the roller 56 of the developing roller 39.

  In the developing cartridge 26, the vertical distance D1 between the lower end edge of the leaf spring member 57 and the uppermost position of the roller 54 of the supply roller 38 is 2 mm or less. By having such a distance D1, The toner charged between the roller 54 of the supply roller 38 and the roller 56 of the developing roller 39 can be promptly sent to the position of the pressing rubber member 60, and high charging of the toner can be made unnecessary. The vertical distance D2 between the lower end edge of the reinforcing plate 59 and the uppermost position of the roller 54 of the supply roller 38 is 15 mm or more. By having such a distance D2, the inside of the toner storage chamber 37 is provided. The toner can be smoothly supplied to the developing roller 39 side.

On the other hand, as shown in FIG. 1, the surface of the photosensitive drum 28 is uniformly positively charged by a scorotron charger 29 and then exposed by high-speed scanning of a laser beam from the scanner unit 17, and is statically based on image data. An electrostatic latent image is formed.
Next, the electrostatic latent image formed on the surface of the photosensitive drum 28 when the toner carried on the developing roller 39 and positively charged comes into contact with the photosensitive drum 28 by rotation of the developing roller 39. That is, the surface of the photosensitive drum 28 that is uniformly positively charged is supplied to an exposed portion that is exposed to a laser beam and the potential is lowered, and is selectively carried to be visualized. Thus, a toner image is formed by reversal development.

Thereafter, the photosensitive drum 28 and the transfer roller 30 are rotationally driven so as to sandwich and convey the sheet 3 therebetween, and the sheet 3 is conveyed between the photosensitive drum 28 and the transfer roller 30. A toner image carried on the surface of the photosensitive drum 28 is transferred onto the paper 3.
Note that the paper dust adhering to the surface of the photosensitive drum 28 by contact with the paper 3 after the transfer, when the surface of the photosensitive drum 28 faces the brush of the cleaning brush 31 as the photosensitive drum 28 rotates, Removed by the brush.

The fixing unit 19 is provided on the rear side of the process cartridge 18, and includes a fixing frame 67, and a heating roller 68 and a pressing roller 69 in the fixing frame 67.
The heating roller 68 includes a metal base tube and a halogen lamp for heating in the metal base tube, and is rotationally driven by power input from a motor (not shown).
The pressing roller 69 is disposed below the heating roller 68 so as to press the heating roller 68. The pressing roller 69 is configured by covering a metal roller shaft with a roller made of a rubber material, and is driven according to the rotational driving of the heating roller 68.

  In the fixing unit 19, the toner transferred onto the sheet 3 is thermally fixed while the sheet 3 passes between the heating roller 68 and the pressing roller 69. The sheet 3 on which the toner is fixed is conveyed to a sheet discharge path 70 extending in the vertical direction toward the upper surface of the main body casing 2. The sheet 3 conveyed to the sheet discharge path 70 is discharged onto a sheet discharge tray 72 formed on the upper surface of the main casing 2 by a sheet discharge roller 71 provided at the upper end of the sheet 3.

  Further, in the developing cartridge 26, as shown in FIG. 9, the leaf spring member 57 and the bending prevention member 58 of the blade unit 40, the front mounting portion 48 of the blade mounting portion 46, and the seal arrangement portion 96 of each side wall 44 are provided. A blade back seal 87 as a second seal member for sealing between the leaf spring member 57 and the bending prevention member 58 and the front mounting portion 48 and the seal arrangement portion 96 is sandwiched therebetween.

  The blade back seal 87 is made of a sponge material such as urethane foam, and as shown in FIG. 10, as shown in FIG. 10, a seal side portion 88 disposed on the roller facing surface 98 of the seal placement portion 96 of each side wall 44, and a blade mounting portion. 46, and a seal connecting portion 89 that extends along the upper edge of the front mounting portion 48 and connects the seal side portions 88 together. In the state in which the blade unit 40 is attached to the blade attachment portion 46, as shown in FIG. 11, the blade back seal 87 has the seal side portions 88 on the back surfaces of the leaf spring members 57 on both sides in the longitudinal direction of the reinforcing plate 59. The seal connecting portion 89 contacts the back surface side of the bending preventing member 58 on the upper side of the reinforcing plate 59. Therefore, the blade unit 40 can be attached to the blade attachment portion 46 without sandwiching the blade back seal 87 between the reinforcing plate 59 and the front attachment portion 48 and the seal placement portions 96 of the side walls 44.

  Further, the blade back seal 87 has a thickness larger than the thickness of the reinforcing plate 59 in the front-rear direction (direction perpendicular to the back surface of the leaf spring member 57) before the blade unit 40 is attached to the blade attachment portion 46. is doing. When the blade unit 40 is attached to the blade attachment portion 46, the blade back seal 87 is attached to the front attachment portion 48 of the blade attachment portion 46 and the seal arrangement portion 96 of the side walls 44 by the leaf spring member 57 and the bending prevention member 58. The leaf spring member 57, the bending prevention member 58, the front mounting portion 48, and the seal placement portion 96 are compressed inward in the opposing direction, and the leaf spring member 57, the bending prevention member 58, the front mounting portion 48, and the seal placement are compressed. Each part 96 is elastically pressed.

  By providing the blade back seal 87, it is possible to seal between the leaf spring member 57 and both ends in the longitudinal direction of the front mounting portion 48 by the respective seal side portions 88, and the bending prevention member 58 and the front mounting portion 48. Can be sealed by a seal connecting portion 89. Therefore, it is possible to prevent the toner that enters the back surface of the leaf spring member 57 from climbing over the upper end portion of the leaf spring member 57 from the back surface and wrapping around the bending prevention member 58. Leakage from between the portion 47 and the blade unit 40 can be reliably prevented.

  The blade back seal 87 is attached to the blade attachment portion 46 and the seal placement portion 96 with double-sided tape before the blade unit 40 is attached to the blade attachment portion 46. For example, after one surface of the double-sided tape is attached to the blade back seal 87, the other surface of the double-sided tape is attached to the blade attachment portion 46 and the seal placement portion 96, whereby the blade back seal 87 and the blade attachment portion 46 and It can be affixed to the seal arrangement part 96. At this time, if a double-sided tape based on polyethylene terephthalate is used, such a double-sided tape is strong, so even if a relatively large force is applied to the blade back seal 87, the deformation of the blade back seal 87 ( (Elongation) can be prevented. Therefore, the blade back seal 87 can be attached with high accuracy.

Further, in this developing cartridge 26, as shown in FIGS. 9 and 10, toner leakage from both ends in the axial direction of the developing roller 39 is prevented at the lower part of the roller facing surface 98 of the seal placement portion 96 of each side wall 44. A side seal 91 is provided for this purpose.
The side seals 91 are provided so as to rub against the surface of the roller 56 at both ends in the axial direction of the roller 56 of the developing roller 39. The side seal 91 includes a sponge seal member 92 as a first seal member, and a felt seal member 93 stacked on the sponge seal member 92.

  The sponge seal member 92 is made of a sponge material such as urethane foam. More specifically, the sponge seal member 92 is made of a urethane foam sponge material (trade name: Polon, manufactured by Roger Sinoac Co., Ltd.) having a relatively high rigidity among the sponge materials. The elastic modulus of the back seal 87 (for example, a pressure of 2000 Pa is indicated when 25% is compressed) (for example, a pressure of 12000 Pa is indicated when 25% is compressed). . Further, as shown in FIG. 12, the sponge seal member 92 has a thickness in the direction facing the roller 56 of the developing roller 39 in a state before the blade unit 40 is attached to the blade attachment portion 46. The thickness (for example, 3 mm) is smaller than the thickness (for example, 4 mm).

  The sponge seal member 92 extends in the vertical direction along the rotation direction of the developing roller 39 on the roller facing surface 98 of the seal arrangement portion 96, and the upper end surface on the downstream side in the rotation direction is the seal of the blade back seal 87. The side portion 88 is connected so as to be adjacent to the lower end surface, and is arranged so that the lower end surface on the upstream side in the rotational direction is flush with the rear end surface 101 of the seal arrangement portion 96 in the front-rear direction. Further, the upper end portion of the sponge seal member 92 is disposed between the leaf spring member 57 and the seal arrangement portion 96 together with the seal side portion 88 of the blade back seal 87, and is sandwiched between them. Note that the sponge seal member 92 is adhered to the roller facing surface 98 of the seal placement portion 96 with a double-sided tape, like the blade back seal 87.

The felt seal member 93 is made of a felt made of polyester fiber and is formed to have the same width as the sponge seal member 92 in the width direction. The felt seal member 93 is formed so that the thickness in the direction facing the developing roller 39 is smaller than the thickness of the sponge seal member 92.
The felt seal member 93 has an upper end on the downstream side in the rotation direction of the developing roller 39 straddling the lower end of the leaf spring member 57 and the sponge seal member 92, and extends along the sponge seal member 92. It is arranged so as to go around the lower surface 102 of the seal arrangement part 96 via the rear end surface 101 of the 96. The surface of the felt seal member 93 that faces the roller 56 of the developing roller 39 is a rubbing surface that rubs against the roller 56. Like the blade back seal 87, the felt seal member 93 is adhered to the lower surface 102 of the seal placement portion 96 from the lower end portion of the leaf spring member 57 via the sponge seal member 92 by double-sided tape. Yes.

  When the developing cartridge 26 is assembled, after the blade back seal 87 is attached to the blade mounting portion 46 and the seal placement portion 96, the sponge seal member 92 is connected to the rear end surface 101 with respect to the rear end face 101 of the seal placement portion 96. The sponge seal member 92 is aligned with the lower end surface on the upstream side in the rotation direction of the developing roller 39 so as to be flush with each other in the front-rear direction, and is stuck on the roller facing surface 98 of the seal arrangement portion 96. Then, after the sponge seal member 92 is disposed, the blade unit 40 is attached to the blade attachment portion 46. At this time, the seal connecting portion 89 of the blade back seal 87 is pressed against the front mounting portion 48 by the upper end portion of the bending preventing member 58 of the blade unit 40, and the sponge seal member is pressed by both longitudinal ends of the leaf spring member 57. The upper end portion of 92 is pressed against the seal arrangement portion 96 together with the seal side portion 88 of the blade back seal 87. After that, the felt seal member 93 is attached to the lower surface 102 of the seal arrangement portion 96 from the lower end portion of the leaf spring member 57 via the sponge seal member 92, and then both end portions of the roller shaft 55 of the developing roller 39. However, the developing roller 39 is supported between the support plate portions 95 of the both side walls 44 by being received in the bearing holes 97 of the support plate portions 95 of the both side walls 44. At this time, the center portion to the lower end portion of the sponge seal member 92 is pressed against the seal arrangement portion 96 by both end portions in the axial direction of the roller 56 of the developing roller 39 via the felt seal member 93. As a result, the thickness of the sponge seal member 92 in the direction in which the developing roller 39 faces the roller 56 is made the same as the thickness of the seal side portion 88 of the blade back seal 87.

  That is, when the blade unit 40 is attached to the blade attachment portion 46 and the developing roller 39 is supported between the two support plate portions 95, the sponge seal member 92 having a relatively large elastic modulus has a relatively small compression amount. The blade back seal 87 having a relatively small elastic modulus is compressed with a relatively large compression amount, so that the thickness of the sponge seal member 92 in the direction facing the roller 56 of the developing roller 39 is reduced. The thickness of the seal side portion 88 of the blade back seal 87 is made the same.

  Therefore, a value obtained by multiplying the elastic modulus of the sponge seal member 92 and the compression amount of the sponge seal member 92 and a value obtained by multiplying the elastic modulus of the blade back seal 87 and the compression amount of the blade back seal 87 are obtained. If the elastic modulus of the sponge seal member 92, the elastic modulus of the blade back seal 87, and the compression amount thereof are set so as to match, the force by which the sponge seal member 92 presses the blade unit 40 and the seal arrangement portion 96, and The force with which the blade back seal 87 presses the blade unit 40 and the seal arrangement portion 96 can be matched equally. Therefore, by using the sponge seal member 92 and the blade back seal 87 having different elasticity, it is possible to reliably prevent toner leakage from the gap between the blade unit 40 and the housing 36 in the opening 41 of the housing 36. . Therefore, even when polymerized toner with good fluidity is used as the developer, the polymerized toner can be prevented from leaking from the gap between the opening 41 of the housing 36 and the developing roller 39.

  Further, since the sponge seal member 92 and the seal side portion 88 of the blade back seal 87 have the same thickness, it is possible to prevent a step between the sponge seal member 92 and the seal side portion 88 of the blade back seal 87, Due to such a step, it is possible to prevent a gap from being generated between the sponge seal member 92 and the leaf spring member 57. Therefore, the leakage of toner from the gap between the opening 41 of the housing 36 and the developing roller 39 can be prevented more reliably.

  In addition, if the rigidity of the blade unit 40 that presses the sponge seal member 92 and the blade back seal 87 is low, the repulsive force from the sponge seal member 92 having a large elastic modulus causes the blade unit 40 and the sponge seal member 92 to be interposed. There is a risk of creating a gap. However, since the blade unit 40 is made of metal and has higher rigidity than the sponge seal member 92, a gap due to a repulsive force from the sponge seal member 92 is generated between the blade unit 40 and the sponge seal member 92. While being able to prevent this, the blade back seal 87 with a small elastic modulus can be reliably pressed by the blade unit 40. Therefore, toner leakage from the gap between the blade unit 40 and the housing 36 in the opening 41 of the housing 36 can be prevented more reliably.

In addition, since the blade unit 40 also serves as a pressing member that presses the sponge seal member 92 and the blade back seal 87, the number of parts of the developing cartridge 26 can be reduced.
Further, since the sponge seal member 92 arranged in the seal arrangement portion 96 has great elasticity, a large torque due to the rotation of the developing roller 39 acts on the sponge seal member 92 via the felt seal member 93. However, it is possible to prevent the adhesion between the felt seal member 93 and the developing roller 39 from being lowered. Therefore, it is possible to reliably prevent toner leakage from both axial ends of the developing roller 39.

  Further, since the process cartridge 18 includes the developing cartridge 26 that can prevent the leakage of toner from the gap between the blade unit 40 and the casing 36 in the opening 41 of the casing 36, Toner leakage can be prevented. Even in the laser printer 1 including such a process cartridge 18, toner leakage from the developing cartridge 26 or the process cartridge 18 can be prevented.

FIG. 13 is a rear view showing another embodiment of the developing cartridge 26. In addition, about the part corresponding to each above-mentioned part, the same referential mark is attached | subjected in FIG. 13, and the description is abbreviate | omitted below.
In the developing cartridge 26 shown in FIG. 13, before the blade unit 40 is attached to the blade attachment portion 46, the upper end portions of the sponge seal members 92 are located at the lower end portions of both seal side portions 88 of the blade back seal 87. They are arranged so as to overlap in the front-rear direction (the direction in which the seal side portion 88 and the sponge seal member 92 are compressed). 14 and 15, the upper end portion of each sponge seal member 92 protrudes toward the lower end portion of each seal side portion 88 (the adjacent direction between the sponge seal member 92 and the seal side portion 88). Two triangular plate-like projecting portions 114 are formed.

  When the developer cartridge 26 is assembled, after the blade back seal 87 is attached to the blade mounting portion 46 and the seal placement portion 96, the sponge seal member 92 is attached to the seal placement portion 96 as shown in FIG. The rear end surface 101 and the lower end surface of the sponge seal member 92 on the upstream side in the rotation direction of the developing roller 39 are aligned so as to be flush with each other in the front-rear direction, and the roller facing surface 98 of the seal placement portion 96 (see FIG. 9). The protruding portion 114 is attached so as to overlap the lower end portion of the seal side portion 88 of the blade back seal 87. Then, after the sponge seal member 92 is arranged, the blade unit 40 (see FIG. 9) is attached to the blade attachment portion 46, and the protruding portions of the sponge seal member 92 are formed by the longitudinal ends of the leaf spring member 57 of the blade unit 40. 114 is pressed against the seal side 88 of the blade back seal 87.

  In this manner, the upper end portion of the sponge seal member 92 having a large elastic modulus is arranged on the lower end portion of the seal side portion 88 having a small elastic modulus, and these are pressed and sandwiched between the leaf spring member 57 and the seal arrangement portion 96. Accordingly, as shown in FIG. 16B, the lower end portion of the seal side portion 88 having a small elastic modulus can be deformed along the shape of the protruding portion 114 at the upper end portion of the sponge seal member 92 having a large elastic modulus. it can. Therefore, it is possible to prevent a gap from being generated in the connection portion between the seal side portion 88 and the sponge seal member 92, and to prevent toner leakage from the connection portion between the seal side portion 88 and the sponge seal member 92. it can.

  In particular, since the protruding portion 114 is formed on the sponge seal member 92, when the sponge seal member 92 is pressed toward the seal side portion 88 of the blade back seal 87 by the leaf spring member 57, the lower end of the seal side portion 88 is pressed. The portion is deformed along the shape of the protruding portion 114. Therefore, it is possible to reliably prevent a gap from being generated in the connection portion between the sponge seal member 92 and the seal side portion 88. As a result, the leakage of toner from the connecting portion between the sponge seal member 92 and the seal side portion 88 can be reliably prevented.

  That is, as shown in FIG. 17A, when the protruding portion 114 is not formed on the upper end portion of the sponge seal member 92, the upper end portion of the sponge seal member 92 is placed on the lower end portion of the seal side portion 88. However, when these are pressed by the leaf spring member 57, there is a possibility that a gap is formed in the connection portion between the seal side portion 88 and the sponge seal member 92 as shown in FIG. On the other hand, if the protruding portion 114 is formed at the upper end portion of the sponge seal member 92, when the sponge seal member 92 is pressed toward the seal side portion 88 of the blade back seal 87 by the leaf spring member 57, By deforming the lower end portion of the seal side portion 88 along the shape of the protruding portion 114, it is possible to prevent a gap as shown in FIG.

Further, when the sponge seal member 92 is disposed, it is possible to allow the upper end portion of the sponge seal member 92 to overlap the lower end portion of the seal side portion 88, so that the effort required for disposing the sponge seal member 92 is reduced. can do.
In this embodiment, the upper end portion of the sponge seal member 92 is disposed on the lower end portion of the seal side portion 88 of the blade back seal 87. However, the sponge seal member 92 is first adhered, and then the blade back seal. 87 may be attached, and the lower end portion of the seal side portion 88 having a small elastic modulus may be disposed on the upper end portion of the sponge seal member 92 having a large elastic modulus. In this case, by pressing the end portions of the sponge seal member 92 and the seal side portion 88 from the seal side portion 88 side having a small elastic modulus toward the seal placement portion 96, the lower end portion of the seal side portion 88 is made the sponge seal member. It can be easily deformed along the shape of the protrusion 114 at the upper end of 92.

In addition, although the two protrusions 114 are formed at the upper end of the sponge seal member 92, only one protrusion 114 may be formed, or three or more protrusions 114 may be formed at the upper end of the sponge seal member 92. It may be formed. Furthermore, such a protrusion 114 may be formed at the lower end of the seal side portion 88.
FIG. 18 is a rear view schematically showing another embodiment of the blade back seal 87 and the sponge seal member 92. In addition, about the part corresponding to each above-mentioned part, the same referential mark is attached | subjected in FIG. 18, and the description is abbreviate | omitted below.

  The blade back seal 87 shown in FIG. 18 is made of a sponge material such as urethane foam, is formed in an elongated rectangular plate shape, and extends along the upper edge of the front mounting portion 48 of the blade mounting portion 46 as a connecting portion. . Further, as shown in FIG. 19, linear concave portions 115 and convex portions 116 extending along the longitudinal direction are orthogonal to the longitudinal direction on the back surface of the blade back seal 87 (contact surface with the leaf spring member 57). Are arranged alternately at intervals in the vertical direction.

  On the other hand, before the blade unit 40 is attached to the blade attachment portion 46, the sponge seal member 92 rotates the developing roller 39 on the roller facing surface 98 (see FIG. 9) of the seal placement portion 96 as a side portion. As shown in FIG. 20 (a), the upper end portion in the vertical direction extending in the vertical direction along the direction enters between the width direction both ends of the blade back seal 87 and the front mounting portion 48, The blade back seal 87 is disposed so as to overlap both ends in the width direction and the front-rear direction (the direction in which the blade back seal 87 and the sponge seal member 92 are compressed). The upper end portion of the sponge seal member 92 overlaps at the lower portion of both end portions in the width direction of the blade back seal 87, and the upper portion of both end portions in the width direction of the blade back seal 87 is exposed from the upper end portion of the sponge seal member 92. .

  Further, as shown in FIG. 18, the front mounting portion 48 of the blade mounting portion 46 is disposed so as to face the connecting portion between the blade back seal 87 and each sponge seal member 92 from the inside of the opening 41, and An L-shaped weir member 117 is provided to prevent toner leakage from the connecting portion. More specifically, the dam member 117 protrudes rearward from the front mounting portion 48 and extends along the sponge seal member 92, and protrudes rearward from the front mounting portion 48 and is orthogonal to the side dam portion 118. And an upper weir 119 extending in a direction along the blade back seal 87.

  After the blade back seal 87 and the sponge seal member 92 are arranged in the above-described state, when the blade unit 40 is attached to the blade attachment portion 46, the blade attachment unit 40 and the seal arrangement portion 48 respectively. It is pressed toward 96 roller facing surfaces 98. As a result, as shown in FIG. 20B, both ends in the width direction of the blade back seal 87 having a small elastic modulus are deformed along the shape of the upper end portion of the sponge seal member 92 having a large elastic modulus. 87 and each sponge seal member 92 are connected without causing a gap in the connection portion. Therefore, it is possible to prevent toner leakage from the connection portion between the blade back seal 87 and each sponge seal member 92.

Further, the weir member 117 can prevent the toner from entering the connecting portion between the blade back seal 87 and each sponge seal member 92. Therefore, the leakage of toner from the connecting portion between the blade back seal 87 and each sponge seal member 92 can be prevented more reliably.
Further, since the concave portion 115 and the convex portion 116 are formed on the contact surface of the blade back seal 87 with the leaf spring member 57, the pressing force by the leaf spring member 57 is convex when pressed by the leaf spring member 57. It can concentrate on the part 116 and the adhesiveness of the leaf | plate spring member 57 and the braid | blade back seal 87 can be improved in the convex part 116. FIG. Therefore, the sealing performance between the leaf spring member 57 and the blade back seal 87 can be enhanced, and toner leakage from the gap between the opening 41 and the developing roller 39 can be more reliably prevented.

Furthermore, since the concave portion 115 and the convex portion 116 are formed in a linear shape, the adhesion between the blade back seal 87 and the blade unit 40 can be enhanced in a region that is long in the longitudinal direction. Therefore, toner leakage from the gap between the opening 41 and the developing roller 39 can be more reliably prevented.
In addition, since the recess 115 and the protrusion 116 extend in the longitudinal direction of the opening 41, that is, in the direction orthogonal to the direction in which the toner leaks from the upper end of the opening 41, the blade unit 40 and the housing 36 in the opening 41. The toner leakage from the gap can be prevented more reliably.

  The concave portion 115 and the convex portion 116 are formed on the contact surface of the blade back seal 87 with the leaf spring member 57. The concave portion 115 and the convex portion 116 are connected to the front mounting portion 48 of the blade mounting portion 46 of the blade back seal 87. It may be formed on both the contact surface of the blade back seal 87 and the contact surface of the blade back seal 87 with the blade unit 40 and the contact surface with the front mounting portion 48. Further, the concave portion 115 and the convex portion 116 may be formed on one or both of the contact surface of the sponge seal member 92 with the blade unit 40 and the contact surface with the seal arrangement portion 96. When the recess 115 and the protrusion 116 are formed in the sponge seal member 92, the recess 115 and the protrusion 116 are formed so as to extend linearly along a direction orthogonal to the longitudinal direction of the opening 41 (that is, a direction orthogonal to the direction in which the toner leaks). To do.

  Further, a weir member for preventing toner leakage from the connecting portion between the blade back seal 87 and the sponge seal member 92 may be provided also in the developing cartridge 26 having the configuration shown in FIG. In this case, the weir member faces the connection portion between each seal side portion 88 of each blade back seal 87 and each sponge seal member 92 from the inside of the opening 41 and extends along the rotation direction of the developing roller 39. It is formed in a plate shape.

1 is a cross-sectional side view of an essential part showing an embodiment of a laser printer as an image forming apparatus of the present invention. FIG. 2 is a side sectional view of the developing cartridge shown in FIG. 1. FIG. 3 is a perspective view of a housing of the developing cartridge shown in FIG. 2. FIG. 3 is a rear view of the blade unit shown in FIG. 2. FIG. 3 is a front view of the blade unit shown in FIG. 2. FIG. 3 is a plan view of the blade unit shown in FIG. 2. FIG. 3 is a side view of the blade unit shown in FIG. 2. FIG. 3 is a rear view showing the configuration of both ends in the longitudinal direction of the developing cartridge shown in FIG. 2. FIG. 3 is a side sectional view showing a configuration of an opening of a housing of the developing cartridge shown in FIG. 2. FIG. 3 is a rear view showing a state where a blade back seal and a side seal are attached to an opening of a housing of the developing cartridge shown in FIG. 2. It is a front view for demonstrating the sticking position of the braid | blade back seal and side seal shown in FIG. It is a sectional side view which shows the state of the opening part before the blade unit shown in FIG. 10 is attached. FIG. 10 is a rear view showing another embodiment of the developing cartridge (an embodiment in which the upper end portion of the sponge seal member is disposed so as to overlap the lower end portion of the seal side portion of the blade back seal). FIG. 14 is a perspective view showing the configuration of one side in the width direction of the developing cartridge shown in FIG. 13. FIG. 14 is a perspective view showing a configuration on the other side in the width direction of the developing cartridge shown in FIG. 13. FIG. 14 is a perspective view for explaining a connection state between the blade back seal and the sponge seal member shown in FIG. 13. It is a perspective view for demonstrating the malfunction when the sponge seal member shown in FIG. 13 does not have a protrusion part. Illustrates another embodiment of a blade back seal and a sponge seal member (an embodiment in which the blade back seal is formed in an elongated rectangular plate shape and a weir member is provided opposite to the connecting portion between the blade back seal and the sponge seal member). FIG. It is a perspective view of the braid | blade back seal shown in FIG. It is a perspective view for demonstrating the connection state of the braid | blade back seal and sponge seal member shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser printer 18 Process cartridge 26 Developing cartridge 36 Case 39 Developing roller 41 Opening part 46 Blade attachment part 57 Leaf spring member 87 Blade back seal 92 Sponge seal member 96 Seal arrangement part 114 Protrusion part 115 Concave part 116 Convex part 117 Weir member

Claims (15)

A housing having a longitudinal opening;
A developer carrier disposed in the opening along the longitudinal direction of the opening and rotatably supported by the housing;
A pressing member disposed in an opening of the housing;
The first elastic modulus is disposed in the opening of the casing, and is sandwiched between the pressing member and the casing in a compressed state with a first compression amount, and the pressing in the opening A first seal member for preventing leakage of developer from a gap between the member and the housing;
The second elastic modulus is smaller than the first elastic modulus, is disposed adjacent to the first seal member at the opening of the housing, and is disposed between the pressing member and the housing. A second seal member that is sandwiched in a state compressed with a second compression amount larger than the compression amount of 1, and prevents leakage of developer from the gap between the pressing member and the housing in the opening. It equipped with a door,
The first seal member and the second seal member are arranged such that end portions adjacent to each other overlap in the compressing direction,
A plurality of projecting portions projecting in the adjacent direction of the first seal member and the second seal member are formed at one of the end portion of the first seal member and the end portion of the second seal member that overlap each other. A developing device.   The first seal member and the second seal member are compressed by the pressing member with the first compression amount and the second compression amount, respectively, so that the casing and the pressing member are opposed to each other. The developing device according to claim 1, wherein the developing devices have the same thickness.   The developing device according to claim 1, wherein the pressing member is made of a hard material. One side end portion presses the developer carrying member, and includes a blade unit for regulating the layer thickness of the developer carried on the developer carrying member,
The developing device according to claim 1, wherein the pressing member is the blade unit. The housing communicates with the opening, and is located at both ends of the opening in the longitudinal direction of the opening and the opening, and in the direction along the communication direction of the opening and the storage, A side portion extending so as to face the developer carrier and the pressing member, and one end portion in a direction perpendicular to the longitudinal direction of the opening and perpendicular to the communication direction extend in the longitudinal direction of the opening. A connecting portion for connecting between the side portions located at both ends in the longitudinal direction,
The first seal member is disposed on the side part,
The developing device according to claim 1, wherein the second seal member is disposed in the connecting portion. The developing device according to claim 1, wherein the second seal member is disposed between the housing and the first seal member. At least one of the first seal member and the second seal member has a concave portion and a convex portion formed on at least one of a contact surface with the housing and a contact surface with the pressing member. the developing device according to any one of claims 1 to 6. The developing device according to claim 7 , wherein the concave portion and the convex portion are formed in a linear shape. The developing device according to claim 8 , wherein the concave portion and the convex portion extend in a direction orthogonal to a direction connecting the inner side and the outer side of the opening. The first seal member is connected to be adjacent to the second seal member,
The housing is disposed to face the connecting portion between the first seal member and the second seal member from the inside of the opening, and includes a weir member for preventing leakage of the developer from the connecting portion. It includes wherein the are developing device according to any one of claims 1 to 9. The developer is characterized by a polymerized toner obtained by polymerizing a polymerizable monomer, a developing device according to any one of claims 1 to 10.   A housing having a longitudinal opening;
  A developer carrier disposed in the opening along the longitudinal direction of the opening and rotatably supported by the housing;
  A pressing member disposed in an opening of the housing;
  The first elastic modulus is disposed in the opening of the casing, and is sandwiched between the pressing member and the casing in a compressed state with a first compression amount, and the pressing in the opening A first seal member for preventing leakage of developer from a gap between the member and the housing;
  The second elastic modulus is smaller than the first elastic modulus, is disposed adjacent to the first seal member at the opening of the housing, and is disposed between the pressing member and the housing. A second seal member that is sandwiched in a state compressed with a second compression amount larger than the compression amount of 1, and prevents leakage of developer from the gap between the pressing member and the housing in the opening. And
  The first seal member is connected to be adjacent to the second seal member,
  The housing is disposed to face the connecting portion between the first seal member and the second seal member from the inside of the opening, and includes a weir member for preventing leakage of the developer from the connecting portion. A developing device comprising: a developing device; In a process cartridge that is detachable from an image forming apparatus,
A process cartridge comprising the developing device according to claim 1. Characterized in that it comprises a developing equipment according to any one of claims 1 to 12, the image forming apparatus.   An image forming apparatus comprising the process cartridge according to claim 13.

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