JP2001281988A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent leaking of developer in a developing device. SOLUTION: In the developing device where a sheet member 83 provided with elasticity is adhered to a casing 51 supporting a developer carrier 59 by double coated adhesive tape 82, while being supported by the double coated adhesive tape 82 and being deflected by pressure from the developer carrier 59, the leaking of the developer from the casing 51 is prevented, an elastic sheet provided with an elasticity in the direction of its thickness is contained in the double coated adhesive tape 82. A space that was often generated by having the sheet member directly adhered to the casing conventionally is solved by intervention of the elastic sheet to the adhered part and therefore, the leaking of the developer is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a developing device for performing development using a developer which is a charged fine particle of an image forming machine.

[0002]

2. Description of the Related Art In a developing device which uses a toner, which is charged fine particles, as a developer and electrostatically adheres the toner to an electrostatic latent image to perform development, there is a problem that the toner leaks from the developing device. is there. If the toner leaks from the developing device, the inside of the image forming machine equipped with the developing device becomes dirty, resulting in poor printing or
In addition, the hands and clothes of the worker become dirty when the developing device is replaced.

[0003] In particular, a non-magnetic monocomponent in which a thin layer of toner is formed by a layer thickness regulating blade on a developing roller having a function of carrying and transporting toner while the toner is opposed to an electrostatic latent image. In the case of development, toner is likely to leak from around the rotating developing roller.

Therefore, conventionally, as shown in FIGS. 6 and 7, a toner leak preventing member is provided inside the developing device to prevent the above toner leak. For example, in order to prevent toner from leaking from both ends of the developing roller 16, the side seals 15 are brought into contact with the peripheral surfaces of both ends of the developing roller 16, and the developing roller 16 is formed below the developing roller 16. The lower film 4 is in contact with the developing roller 16 below the developing roller 16 in order to prevent toner leakage from a gap between the housing 3 and the opening.

The side seal 15 has a structure in which a sliding member made of Teflon (registered trademark) is attached to a urethane sponge. Urethane sponges are required to be sufficiently soft and have low compression set. Teflon felt is used for both securing the pressing force and reducing the rotational torque. Side seal 15
Is adhered to the housing 3 by the double-sided adhesive tape 5.

The lower film 4 is made of PET (polyethy
For example, a lene terephthalate sheet or urethane rubber is used. Although urethane rubber can be expected to be softly pressed, it is necessary to press it with a sponge or the like from the back because it has no waist. Since the PET sheet is harder than the urethane rubber film, there is no need to press with a sponge or the like from the back, and there is an advantage that the assembling work is easier than the urethane rubber film. The lower film 4 is also adhered on the housing 3 by the double-sided adhesive tape 6.

However, when the side seal 15 and the lower film 4 are used as described above, when the side seal 15 is rubbed against the peripheral surface of the developing roller 16, a joining portion between the lower film 4 and the side seal 15 is formed. However, there is a problem that the toner is liable to leak.

For example, if the length of the lower film 4 is set to such a length that the lower film 4 does not overlap with the side seal 15, toner leaks from a gap between the lower film 4 and the side seal 15.

Further, both end portions of the lower film 4 are extended outward from both end portions of the side seal 15 so that the developing roller 16
When the lower film 4 is placed in contact with both the lower film 4 and the side seal 15, a minute gap corresponding to the thickness of the lower film 4 is generated where the lower film 4 rides on the side seal 15, and toner leaks from this gap. Sometimes. In particular, when a polymerized toner having excellent fluidity is used as the toner, toner leakage occurs even in such a small gap.

Therefore, it is considered that the length of the lower film 4 is set to such a length that both end portions of the lower film 4 are located near the center of the sliding portion of the side seal 15.

With such a configuration, a gap corresponding to the thickness of the lower film 4 generated in a portion where the lower film 4 rides on the side seal 15 is interrupted in the middle of the side seal 15, and as a result, Even when toner is used, toner leakage can be almost prevented.

However, the side seal 15 is
When the developing roller 16 is attached, it is crushed by the developing roller 16 so that the developing roller 16 comes into pressure contact with the developing roller 16 and has a thickness in consideration of the amount of crushing in advance. However, if the crushing amount is set too large, the pressing force of the side seal 15 against the developing roller 16 becomes too high, and the rotational torque of the developing roller 16 increases. Therefore, the mounting portion of the side seal 15 is previously adjusted so that the height of the surface of the side seal 15 is equal to the height of the mounting portion of the lower film 4 when the side seal 15 is crushed by an appropriate amount by the developing roller 16. A step is provided so as to be lower than the attachment portion of the film 4.

In such a configuration, when the side seal 15 is crushed by the developing roller 16, the side seal 15 rubs against the side wall surface forming the step, and the surface height of the side seal 15 is reduced by the mounting portion of the lower film 4. Height. The side seal 15 is provided with a developing roller 16.
Is slightly vibrated in accordance with the rotation of the roller, so that the rubbing between the side wall surface and the side seal side surface is small, even during the developing operation.

Therefore, the side surface of the side seal 15 and the side wall surface cannot be bonded with a double-sided adhesive tape or the like.
In addition, the rubbing portion between the side wall surface and the side seal side surface is an interface between the resin and the sponge. As described above, the sponge rubs against the resin surface or vibrates minutely. In this case, the adhesion at this interface is extremely low. As a result, when a polymerizable toner having extremely high fluidity is used as the developer, the toner easily leaks from the interface between the resin and the sponge.

Further, both ends of the lower film 4 located near the center of the sliding portion of the side seal 15 are
Before mounting 6, the side seal 15 is deformed so as to be bent upward by the difference in height between the mounting surface of the lower film 4 and the surface of the sliding portion of the side seal 15 because the side seal 15 is not crushed. .

When the developing roller 16 is mounted in such a state, the side seal 15 is crushed, and both ends of the lower film 4 which have been deformed upward follow the side seal 15. Crushed. As a result, there is a problem that the bonded portion of the lower film 4 is displaced, or the lower film 4 is deformed and the toner sealing property is reduced.

Therefore, the lower film 4 and the side seal 1
In order to more reliably prevent the toner from leaking from the joint with the lower film 5, as shown in FIG. 6 and FIG. It has been proposed to provide a lower side seal 7 made of a foamed elastic body, and to adhere the lower side seal 7 to the housing 3 with a double-sided adhesive tape 8.

[0018]

As described above, the developing device disclosed in Japanese Patent Application No. 11-200389 is provided with a sponge lower side seal 7 at the joint between the lower film 4 and the side seal 15. The sponge of the lower side seal 7 is sandwiched between the lower film 4 and the housing 3, and the sponge of the lower side seal 7 is bent to be depressed by the developing roller 16. The lower film 4 is pressed so as not to float.

However, in such a configuration, the sponge serving as the lower side seal 7 is attached to the lower film 4 and the housing 3.
It is difficult to provide such a contact with the adhesive portion between the two without any gap. Therefore, there is a problem that a minute gap 9 is generated and the developer leaks from the gap 9.

If the gap 9 is to be completely eliminated, the elastic force generated by compressing the sponge, which is the lower side seal 7, is concentrated on the boundary 6a between the bonded portion and the non-bonded portion of the lower film 4. This causes problems such as deformation of the lower film 4 at this portion and peeling of the double-sided adhesive tape 6 for bonding the lower film 4 to the housing 3. The lower film 4 is deformed or the double-sided adhesive tape 6
Peeling off causes toner leakage.

It is an object of the present invention to solve such a problem and to provide a developing device capable of more reliably preventing toner leakage.

[0022]

In order to solve the above-mentioned problems, according to the present invention, an elastic sheet-like member is adhered to a housing supporting a developer carrying member by a double-sided adhesive tape. While being supported by the adhesive tape, the developing device is bent by the pressure from the developer carrier to prevent leakage of the developer from the housing, wherein the double-sided adhesive tape includes an elastic sheet having elasticity in a thickness direction. Is adopted.

According to the first aspect of the present invention, the gap which was apt to be caused by the conventional sheet member being directly bonded to the housing is eliminated by the interposition of the elastic sheet at the bonding portion, so that the developer leaks. Is prevented.

According to a second aspect of the present invention, there is provided the developing device according to the first aspect, wherein the elastic sheet is formed of a foam.

According to the second aspect of the present invention, a sufficient amount of deformation can be obtained even if the thickness of the elastic sheet is small.

According to a third aspect of the present invention, there is provided the developing device according to the first or second aspect, wherein the thickness of the double-sided adhesive tape is 0.4 mm or more.

According to a fourth aspect of the present invention, there is provided the developing device according to any one of the first to third aspects, wherein the sheet member is a resin sheet.

According to the fourth aspect of the present invention, since the sheet-shaped member is a resin sheet, the sheet-shaped member is easy to handle and has good assemblability.

According to a fifth aspect of the present invention, there is provided the developing device according to any one of the first to fourth aspects, wherein the sheet-like member rubs against the surface of the developer carrier.

According to the fifth aspect of the present invention, since the sheet-like member must be strongly pressed against the moving developer carrier, a large elastic force is applied to the sheet-like member, but this elastic force is absorbed by the elastic sheet. can do.

According to a sixth aspect of the present invention, there is provided the developing device according to any one of the first to fifth aspects, wherein a foamed elastic body is compression-inserted between the sheet-like member and the housing.

According to the sixth aspect of the present invention, since the foamed elastic body is interposed between the sheet-shaped member and the housing, the pressing force due to the deformation of the foamed elastic body acts on the sheet-shaped member. The pressing force can be reduced by the elastic sheet.

The invention according to claim 7 employs the developing device according to claim 6, wherein the foamed elastic body is in contact with the double-sided adhesive tape.

According to the seventh aspect of the present invention, by bringing the foamed elastic body into contact with the double-sided adhesive tape without any gap,
It is possible to prevent the developer from leaking from this portion.

According to an eighth aspect of the present invention, there is provided the developing device according to the sixth or seventh aspect, wherein the double-sided adhesive tape is also adhered to the elastic foam.

According to the eighth aspect of the present invention, it is possible to prevent the developer from leaking from between the double-sided pressure-sensitive adhesive tape and the foamed elastic body.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

First, the general outline of the image forming machine to which the developing device is mounted will be described.

The image forming apparatus shown in FIG. 1 is a laser beam printer 1. The laser beam printer 1 includes a feeder unit for feeding paper (not shown) at the bottom of a main body case 2. The feeder unit includes a paper pressing plate 10 pressed by a spring (not shown), a paper feed roller 11, and a friction separating member 14.
The paper is pressed against the paper feed roller 11 by the
The uppermost sheet is separated between the feed roller 11 and the friction separating member 14 by the rotation of the roller, and the sheet is supplied at a predetermined timing.

A pair of registration rollers 12 and 13 are rotatably supported on the downstream side in the paper transport direction by the rotation of the paper feed roller 11 rotating in the direction of the arrow in FIG. The sheet is conveyed to a transfer position formed by the roller 21 at a predetermined timing.

The photosensitive drum 20 is made of a positively chargeable material, for example, an organic photoreceptor mainly containing positively chargeable polycarbonate. More specifically, the photosensitive drum 20 has, for example, a cylindrical aluminum sleeve as a main body, and has a predetermined thickness (for example, about 20 μm) in which a photoconductive resin is dispersed in polycarbonate on an outer peripheral portion thereof. It is composed of a hollow drum on which a conductive layer is formed, and is rotatably supported by the main body case 2 with the cylindrical sleeve grounded. Further, the photosensitive drum 20 is driven to rotate in a direction indicated by an arrow by driving means (not shown).

The charger 30 is, for example, a scorotron type charger for positive charging for generating corona discharge from a charging wire made of tungsten or the like.

The laser scanner unit 40 includes a laser generator (not shown) for generating a laser beam L for forming an electrostatic latent image on the photosensitive drum 20, and a polygon mirror (pentahedral mirror) 41 that is driven to rotate. , A pair of lenses 42 and 4
5 and reflection mirrors 43, 44 and 46.

As shown in FIG. 2, in the developing device 50, a toner accommodating chamber 52 as a developer chamber is formed in a housing 51, and an agitator 53 and a cleaning member 54 are provided in the toner accommodating chamber 52. It is rotatably provided around a rotation shaft 55. In the toner storage chamber 52, a positively chargeable nonmagnetic one-component developer having electrical insulation is stored. The rotation shaft 55 of the toner storage chamber 52
Light transmitting windows 56 are provided on the side walls located at both ends of the light emitting element. On the photosensitive drum 20 side of the toner accommodating chamber 52, a developing chamber 57 that communicates with the toner accommodating chamber 52 through the opening A to perform development is formed, and a supply roller 58 and a developing roller 59 as a developer carrier are rotated. Pivot as possible.
The toner on the developing roller 59 is regulated to a predetermined layer thickness by a thin plate-like elastic layer thickness regulating blade 64 and is used for development.

Here, a developing roller 59 as a developer carrying member is a cylindrical metal formed of conductive silicone rubber containing fine particles of conductive carbon on a metal core formed of stainless steel or the like. A base material is provided, and a coat layer of a resin or rubber material containing fluorine is formed on the base material. The base of the developing roller 59 does not necessarily have to be made of conductive silicone rubber, and may be made of conductive urethane rubber.

The toner accommodated in the toner accommodating chamber 52 is a positively-charged non-magnetic one-component developer, and a styrene-acrylic resin formed into a spherical shape by a suspension polymerization method, such as carbon black or the like. The toner base particles have a particle size of 6 μm to 10 μm and an average particle size of 8 μm to which a well-known coloring agent and a charge control agent such as nigrosine, triphenylmethane, and quaternary ammonium salt are added. The toner is configured by adding silica as an external additive to the surface of the toner base particles.

The transfer roller 21 is rotatably pivotally supported,
It is made of a conductive foamed elastic body made of silicone rubber or urethane rubber. The transfer roller 21 is configured to reliably transfer the toner image on the photosensitive drum 20 to the paper by the applied voltage.

The fixing unit 70 includes the registration roller 12
The heating roller 71 and the pressing roller 72 are provided on the further downstream side in the sheet conveyance direction from the sheet feeding roller 13 to the pressure contact portion between the photosensitive drum 20 and the transfer roller 21. The toner image transferred to the sheet is heated and pressed while being conveyed by the heating roller 71 and the pressing roller 72 and is fixed on the sheet.

A pair of transport rollers 73 and a paper discharge roller 74 for paper transport are provided on the downstream side in the transport direction of the fixing unit 70, respectively, and a paper output tray 75 is provided on the downstream side of the paper discharge roller 74. Have been.

The above-described photosensitive drum 20, transfer roller 21, charger 30, and developing device 50 are housed in a process cartridge 2a, and the process cartridge 2a is detachably attached to the laser beam printer 1. Is provided. Further, the developing device 50 is provided as a developing device cartridge detachably from the process cartridge 2a.

In the laser beam printer 1 described above, when the surface of the photosensitive drum 20 is uniformly charged by the charger 30 and the laser beam L modulated according to the image information is emitted from the laser scanner unit 40, the photosensitive drum 20 is exposed. An electrostatic latent image is formed on the surface of the drum 20. This electrostatic latent image is visualized with toner by the developing device 50, and the visible image formed on the photosensitive drum 20 is transported by the photosensitive drum 20 to a transfer position. At the transfer position, the paper is supplied via the paper feed roller 11 and the registration rollers 12 and 13, and the visible image is transferred to the paper by the transfer bias applied by the transfer roller 21. The toner remaining on the photosensitive drum 20 after the transfer is collected in the developing chamber 57 by the developing roller 59.

Next, the sheet is conveyed to the fixing unit 70, is nipped and conveyed by the heating roller 71 and the pressing roller 72 of the fixing unit 70, and the visible image on the sheet is pressed and heated to be fixed on the sheet. You. Then, the sheet is discharged to the discharge tray 75 above the laser beam printer 1 by the pair of transport rollers 73 and the discharge rollers 74, and the image forming operation is completed.

The developing device has the following seal structure for preventing toner from leaking between the developing roller and the housing.

That is, as shown in FIGS. 2 to 5, this sealing structure is provided near the longitudinal ends of the opening of the housing 51 so as to be in contact with the peripheral surfaces of both ends of the developing roller 59. , A lower side seal 81 having elasticity provided on the housing 51 so as to be in contact with the side seal 80, and a developing roller The developing roller 59 is provided on the peripheral surface of the developing roller
And a lower film 83 adhered to the lower end of the opening of the housing 51 with a double-sided adhesive tape 82 so as to be in uniform contact over the longitudinal direction and to cover the lower side seal 81.

The lower film 83 is a sheet-like member having elasticity. The lower film 83 is adhered to the housing 51 supporting the developing roller 59 with a double-sided adhesive tape 82. To prevent the developer from leaking from the housing 51. The lower film 83 is made of, for example, a resin sheet. The lower film 83 prevents the toner from leaking out of the housing 51 while rubbing against the surface of the rotating developing roller 59. The double-sided adhesive tape 82 for bonding the lower film 83 to the housing 51 will be described later.

The side seal 80 has the same structure as that of the related art, and is specifically formed of a square pillar-shaped sponge, and corresponds to both ends of the developing roller 59 in the housing 51 as shown in FIGS. It is adhered to a location with a double-sided adhesive tape 84. As the double-sided pressure-sensitive adhesive tape 84, for example, a tape in which a pressure-sensitive adhesive is applied to the front and back surfaces of a non-woven fabric at a uniform thickness is used. The side seal 80 is compressed and elastically deformed on the peripheral surfaces of both ends of the developing roller 59 rotatably supported by the housing 51, whereby the surface of the side seal 80 is rotated around the both ends of the rotating developing roller 59. The developer is prevented from leaking in the side direction while contacting the surface with an appropriate pressure.

The lower side seal 81 is made of a sponge, which is a rectangular parallelepiped foamed elastic body as in the prior art. As shown in FIGS. 3 and 4, the double-sided adhesive tape 85 is placed on the housing 51 so as to be in contact with the side seal 80. It is glued. The same double-sided adhesive tape 85 as that used for bonding the side seal 80 is used. The lower side seal 81 is sandwiched between the lower film 83 and the housing 51, and is pressed by the lower film 83 which is bent by the pressing from the developing roller 59. Thereby, the lower side seal 8 which is a foamed elastic body is formed.
Reference numeral 1 denotes a part to be compressed and inserted between the lower film 83 and the housing 51, and closes the lower film 83 and the housing 51 so that no gap is formed between the lower film 83 and the housing 51. To prevent toner leakage.

As already described with reference to FIGS. 6 and 7, it is difficult to provide the lower side seal 81 so as to be in contact with the bonding portion between the lower film 83 and the housing 51 without any gap. For this reason, a minute gap 9 is generated at the boundary 6a between the bonded portion and the non-bonded portion, and the developer may leak from the gap 9. If the gap 9 is to be completely eliminated, the elastic force generated by compressing the sponge, which is the lower side seal 15, will concentrate on the boundary 6a between the bonded portion and the non-bonded portion of the lower film 4, At this portion, problems such as deformation of the lower film 4 and peeling of the double-sided adhesive tape 6 for bonding the lower film 4 to the housing 3 occur.

In order to prevent the toner from leaking due to the deformation of the lower film and the peeling of the double-sided adhesive tape, in the present invention, the double-sided adhesive tape 82 for bonding the lower film 83 to the housing 51 has a thickness direction. An elastic sheet 82a having elasticity is provided.

Specifically, this double-sided adhesive tape 82
A foam base material type (product number # 8404B black) manufactured by Dainippon Ink and Chemicals, Inc. is used. This double-sided pressure-sensitive adhesive tape 82 uses a special polyolefin foam for the elastic sheet 82a as a base material, while using an acrylic pressure-sensitive adhesive as a pressure-sensitive adhesive applied to both sides of the elastic sheet 82a, thereby providing a favorable Shape followability and adhesiveness can be ensured.

The double-sided adhesive tape 82 is 0.4 m
As a result of an experiment, it was confirmed that toner leakage can be satisfactorily prevented if the tape layer has a thickness of 0.4 mm or more. Furthermore, this double-sided adhesive tape 82 has an adhesive force of 2000 g / 20 mm (when peeling a 20-mm-wide band-shaped tape from an end portion,
g). As a result of the experiment, if the adhesive force is 2000 g / 20 mm or more, the elastic sheet 82a can withstand the expansion and contraction. It was confirmed that it could be prevented.

As described above, the lower film 8 having elasticity
3 is a double-sided adhesive tape 8 including an elastic sheet 82a having elasticity in the thickness direction on a housing 51 supporting the developing roller 59.
2 and is bent by the pressure from the developing roller 59 while being supported by the double-sided adhesive tape 82. Therefore, even if the elastic force of the side seal 80 acts on the lower film 83, the sponge is an elastic sheet 82a. Since the layer is deformed to absorb this elastic force, the lower film 83
The stress does not concentrate on the boundary between the bonded portion and the non-bonded portion, and peeling of the lower film 83 from the housing 51 is prevented. Also,
In the present invention, a gap 9 (see FIGS. 6 and 7) generated at a position between the lower film 4 and the housing 3 at the upstream end in the developing roller rotation direction of the conventional lower side seal 7 is used in the present invention. The end face 86 of the elastic sheet 82a made of a sponge or the like of the double-sided adhesive tape 82 is closed by the contact between the end face 87 of the lower side seal 81 and the developer is prevented from leaking from this location.

The end face 8 of the lower side seal 81
The end face 86 of the elastic sheet 82a of the double-sided adhesive tape 82 may be adhered to the adhesive sheet 7 with the adhesive layer 82b of the double-sided adhesive tape 82. As a result, it is possible to reliably close the gap that has conventionally been easily generated.

The present invention has been described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. is there. For example, in the embodiment, the lower film has been described as an example, but exactly the same effect can be obtained as long as the sheet-like member prevents the developer from leaking. Further, in the embodiment, the example in which the elastic force due to the compression of the developer leakage prevention member of the sponge concentrates on the stress, but without the sponge, the lower film is bent and pressed against the developing roller. In such a case, the present invention is effective in preventing the bending stress from being concentrated on the boundary between the bonded portion and the non-bonded portion. Further, the double-sided adhesive tape 82
May be configured such that a double-sided pressure-sensitive adhesive tape having a conventional nonwoven fabric or the like as a base material is adhered to the front and back of a tape-shaped foam. Further, in the present embodiment, an example in which the lower film 83 directly rubs against the developing roller 59 has been described. However, the present invention is not limited thereto, and a rubbing member may be provided between the developing roller 59 and the lower film 83. May be separately provided.

[0065]

According to the first aspect of the present invention, the lower film 83, which is a sheet-like member having elasticity, is adhered to the housing 51 supporting the developing roller 59, which is a developer carrier, by the double-sided adhesive tape 82. While being supported by the double-sided adhesive tape 82, the double-sided adhesive tape is bent in the thickness direction by an elastic sheet 82 a in a developing device which bends by pressing from the developer carrier to prevent leakage of the developer from the housing. Because of the inclusion, the gap 9 that was apt to be caused by the conventional sheet member being directly bonded to the housing is eliminated by the interposition of the elastic sheet 82a in the bonding portion, and thus leakage of the developer is prevented.

According to the second aspect of the invention, since the elastic sheet 82a is formed of a foam in the developing device according to the first aspect, a sufficient amount of deformation can be obtained even if the thickness of the elastic sheet 82a is small. be able to.

According to the third aspect of the present invention, the double-sided adhesive tape 82 in the developing device according to the first or second aspect is made 0.4 mm or more. Leakage can be satisfactorily prevented.

According to the fourth aspect of the present invention, since the lower film 83 as the sheet-like member in the developing device according to any one of the first to third aspects is a resin sheet, the handling of the sheet-like member is easy. It is easy to assemble.

According to the fifth aspect of the present invention, the lower film 83 which is a sheet-like member in the developing device according to any one of the first to fourth aspects slides on the surface of the developing roller 59 which is a developer carrier. Due to the rubbing, the sheet-like member must be strongly pressed against the moving developer carrier, so that a large elastic force is applied to the sheet-like member. This elastic force can be absorbed by the elastic sheet 82a.

According to the sixth aspect of the present invention, the lower side seal 81 which is a foamed elastic body is provided between the housing 51 and the lower film 83 which is a sheet-like member in the developing device according to any one of the first to fifth aspects. Is compressed and inserted, a foamed elastic body is interposed between the sheet-shaped member and the housing, and the pressing force due to the deformation of the foamed elastic body acts on the sheet-shaped member,
This pressing force can be reduced by the elastic sheet 82a.

According to the seventh aspect of the present invention, since the lower side seal 81, which is a foamed elastic body of the developing device according to the sixth aspect, is in contact with the double-sided adhesive tape 82, the foamed elastic body is bonded to the double-sided adhesive tape. With no contact with the gap, leakage of the developer from this portion can be prevented.

According to the eighth aspect of the present invention, the double-sided adhesive tape 82 of the developing device according to the sixth or seventh aspect is also adhered to the lower side seal 81 which is a foamed elastic body. The developer can be prevented from leaking from between the adhesive tape 82 and the foamed elastic body.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of an image forming machine to which a developing device according to the present invention is mounted.

FIG. 2 is an enlarged sectional view of the developing device shown in FIG.

FIG. 3 is a partially cutaway perspective view showing one side of the developing device shown in FIG. 1;

4A is an exploded cross-sectional view of a portion from a developing roller to a housing at a location shown in FIG. 3, and FIG. 4B is a sectional view of FIG.
FIG.

FIG. 5 is a sectional view taken along line VV in FIG. 4 (B).

FIG. 6 is a diagram showing a conventional example in comparison with FIG.

7 is a diagram showing a conventional example in comparison with FIG. 5, and FIG.
FIG. 7B is a sectional view taken along line VII-VII in FIG.

[Explanation of symbols]

 51: housing 59: developing roller 59 81: lower side seal 82: double-sided adhesive tape 82a: elastic sheet 83: lower film

Claims (8)

[Claims] 1. A sheet-like member having elasticity is adhered to a housing supporting a developer carrying member with a double-sided adhesive tape, and while being supported by the double-sided adhesive tape, bends by being pressed from the developer carrying member. A developing device for preventing leakage of a developer from a housing, wherein the double-sided adhesive tape includes an elastic sheet having elasticity in a thickness direction. 2. The developing device according to claim 1, wherein said elastic sheet is formed of a foam. 3. The thickness of the double-sided pressure-sensitive adhesive tape is 0.4 mm.
The developing device according to claim 1, wherein: 4. The developing device according to claim 1, wherein said sheet member is a resin sheet. 5. The image forming apparatus according to claim 1, wherein said sheet member rubs against a surface of said developer carrier.
The developing device according to any one of the above. 6. The developing device according to claim 1, wherein a foamed elastic body is compression-inserted between the sheet-like member and the housing. 7. The developing device according to claim 6, wherein the foamed elastic body is in contact with the double-sided adhesive tape. 8. The developing device according to claim 6, wherein the double-sided pressure-sensitive adhesive tape is also adhered to the foamed elastic body.