JP2001060038A - Developing device, process cartridge, developing unit cartridge and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a fogging due to the influence of toner accumulated on the back surface side of a layer thickness regulating blade even when the layer thickness of the toner on a developing roller is regulated by using the layer thickness regulating blade by providing a partition member between the back surface part of a developer layer thickness regulating member and the developer storing chamber of a developing unit. SOLUTION: The developing device is provided with the partition member having a shape by which developer is made to drop between the back surface part of the developer layer thickness regulating member and the developer storing chamber of the developing unit. And also, it is provided with a developer advance preventing member consisting of a foamed elastic body so as to come in contact with both the back surface part of the developer layer thickness regulating member and the partition member. Namely, this developing device 50 is provided with a rib 51b functioning as the partition member between the layer thickness regulating blade 64 and an aperture part A so as to prevent the toner from moving to the back surface side of the blade 64. Then, it is provided with a rib sponge 117 functioning as the developer advance preventing member so as to press-contact with the rib 51b. Thus, the toner is surely prevented from advancing to the back surface side of the blade 64.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technical field of a developing apparatus, a process cartridge, a developing cartridge, and an image forming apparatus provided with any one of them for developing using a developer which is charged fine particles. Belong to.

[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 apparatus main body equipped with the developing device becomes dirty, resulting in poor printing, and further, when the developing device is replaced, the hands and clothes of the worker become dirty. There was sometimes.

In particular, a non-magnetic one-component developing a thin layer of toner on a developing roller having a function of carrying and transporting the toner by using a layer thickness regulating blade and facing the electrostatic latent image. In the case of development, toner is likely to leak from around the rotating developing roller.

Conventionally, the above-described toner leakage has been prevented by providing a toner leakage prevention member inside the developing device. For example, in order to prevent toner leakage from both ends of the developing roller around the developing roller, a toner leakage preventing member called a side seal is rubbed against the peripheral surfaces of both ends of the developing roller, In order to prevent toner from leaking from the gap between the developing roller formed below and the opening of the toner container, a toner leak preventing member called a lower film is rubbed against the developing roller below the developing roller. . Further, in order to prevent toner from leaking from the gap between the developing roller formed above the developing roller and the opening of the toner container, the layer thickness regulating blade is pressed against the developing roller, and the layer thickness is reduced. The regulating blade has a function as a toner leakage preventing member.

[0005]

However, the layer thickness regulating blade has a structure in which a leaf spring member is mounted on a support member, and a rubber pressing member is mounted on the surface of the leaf spring member. In order to press the pressing member in a so-called counter direction with respect to the rotation direction of the developing roller, it is necessary to mount the pressing member at a predetermined angle with respect to the vertical direction. In other words, rather than the mounting position of the upper support member,
The lower pressing member is attached obliquely so as to face the inner side of the toner container.

Accordingly, when the toner enters the back side of the support member and the leaf spring member opposite to the front side on which the pressing member is attached, the toner does not drop and accumulates on the back side. Easier to do.

[0007] Since the toner thus accumulated is not circulated in the toner container, it is uncharged or insufficiently charged. Such uncharged or undercharged toner falls into the toner container from the back side due to vibration or the like, and is mixed into the normally charged toner. As a result, the layer thickness regulation using electrostatic force cannot be performed on the uncharged or undercharged toner. Therefore, the uncharged or undercharged toner is not disposed between the layer thickness regulation blade and the developing roller. It passes through the thickness regulation part. Further, also in the development area, since the development control utilizing the action of the electric field cannot be performed on the uncharged or undercharged toner, the uncharged or undercharged toner is exposed to the exposed state on the photosensitive drum. Is transferred to the photosensitive drum regardless of the position. If the transfer is performed in such a state, the toner is transferred to a white background portion where the toner is not originally transferred, and development called so-called fog occurs.

The present invention solves such a problem, and even when the layer thickness of the toner on the developing roller is regulated by using the layer thickness regulating blade, the influence of the toner accumulated on the back surface side of the layer thickness regulating blade. Developing device, process cartridge, developing device cartridge capable of preventing fog due to
And an image forming apparatus.

[0009]

According to a first aspect of the present invention, there is provided a developing device, wherein a developer carrier is rotatably disposed in an opening of a developing device housing for accommodating a developer. ,
A developing device that forms a visible image by causing a thin layer of developer formed on the developer carrier to face an electrostatic latent image, and is formed to extend in a longitudinal direction of the developer carrier,
A developer layer thickness regulating member for forming a thin layer of the developer on the peripheral surface of the developer carrying member by a pressing member provided on a front surface portion; a back surface portion of the developer layer thickness regulating member; And a partition member provided with a shape or an angle for dropping the developer between the developer storage chamber and the rear surface portion of the developer layer thickness regulating member and the partition member. And a developer intrusion prevention member formed of a foamed elastic body.

According to the first aspect of the present invention, since the partition member is provided between the back surface of the developer layer thickness regulating member and the developer accommodating chamber of the developing device, the developer accommodating chamber is provided. Does not reach the back surface of the developer layer thickness regulating member. Further, since the partition member is provided with a shape or an angle that allows the developer to drop, even if the developer adheres to the partition member, the developer immediately drops,
It does not accumulate on the partition member. Therefore, circulation of the toner is not hindered. Further, between the back surface of the developer layer thickness regulating member and the partition member, so as to contact both,
A developer entry preventing member made of a foamed elastic body is provided.
Therefore, the developer does not enter from between the back surface of the developer layer thickness regulating member and the partition member. As described above, the toner is reliably prevented from entering the back surface of the developer layer thickness regulating member, so that no toner is deposited on the back surface of the developer layer thickness regulating member, and fog is prevented.

According to a second aspect of the present invention, in order to solve the above-mentioned problem, in the developing device according to the first aspect, the developer intrusion preventing member includes a pressing member provided on a rear surface of the developer layer thickness regulating member. It is characterized in that it is provided so as to be in contact with the back surface portion outside the region corresponding to the adhesive attachment of the member.

According to the second aspect of the present invention, the developer intrusion preventing member is attached to the back surface of the developer layer thickness regulating member. It is not attached to the area corresponding to the area. Therefore, the pressing force of the pressing member against the developer carrier is not changed.

According to a third aspect of the present invention, in order to solve the above-mentioned problem, in the developing device according to the first or second aspect, the developer intrusion preventing member is provided on a back surface of the developer layer thickness regulating member. It is characterized by being adhered and attached.

According to the third aspect of the present invention, since the developer intrusion preventing member is attached to the back surface of the developer layer thickness regulating member by adhesion, the developer layer thickness regulating member is attached to the developing device. Thereby, the developer entry preventing member can be brought into pressure contact with the partition member.

According to a fourth aspect of the present invention, in order to solve the above-mentioned problem, in the developing device according to the first or second aspect, the developer intrusion preventing member is bonded and attached to the partition member. Features.

According to the fourth aspect of the present invention, the developer intrusion preventing member is bonded and attached to the partition member. Therefore, by attaching the developer layer thickness regulating member to the developing device, the developer intrusion preventing member is provided. Can be brought into pressure contact with the developer layer thickness regulating member.

According to a fifth aspect of the present invention, in order to solve the above problem, in the developing device according to any one of the first to fourth aspects, the developer is a polymerized toner produced by a polymerization method. It is characterized by the following.

According to the developing device of the present invention, since the polymerized toner produced by the polymerization method is used as the developer, the developing operation with high fluidity and high definition is performed. However, this polymerized toner is liable to cause toner leakage due to its high fluidity, and easily enters the back side of the developer layer thickness regulating member. Since the member is provided, it is possible to reliably prevent the developer from entering the back surface side of the developer layer thickness regulating member.

According to a sixth aspect of the present invention, in order to solve the above-mentioned problem, in the developing device according to the second aspect, the developer carrier is a roller formed of a conductive elastic material. It is characterized by.

According to the developing device of the present invention, since a roller formed of a conductive elastic material is used as the developer carrying member, the developing device is controlled by the pressing force of the pressing member of the developer layer thickness regulating member. Although the regulation amount of the layer thickness and the ability to prevent developer leakage are liable to fluctuate, as described above, the developer intrusion prevention member is attached outside the area corresponding to the area where the pressing member is adhered and attached. Instead, the desired layer thickness regulating power and developer leakage prevention ability are exerted.

According to a seventh aspect of the present invention, there is provided a process cartridge comprising:
7. A process cartridge detachably formed in an image forming apparatus for solving the above-mentioned problem, comprising: a carrier for the electrostatic latent image; and the developing device according to claim 1. It is characterized by having.

According to the process cartridge of the present invention, the process cartridge detachably formed in the image forming apparatus is provided with the developing device of any one of the first to sixth aspects. When attaching or detaching the cartridge, there is a possibility that the developer may enter the back surface side of the developer layer thickness regulating member, but as described above, not only the partition member but also the developer entry preventing member is provided, Even in such a case, it is possible to reliably prevent the developer from entering the back surface of the developer layer thickness regulating member.

According to an eighth aspect of the present invention, in order to solve the above problem, the developing device according to any one of the first to sixth aspects is configured such that the developing device is detachably attached to an image forming apparatus or a process cartridge. It is characterized by the following.

According to the developing device cartridge according to the eighth aspect, the developing device according to any one of the first to sixth aspects,
Since it is formed detachably with respect to the image forming apparatus or the process cartridge, there is a possibility that the developer may enter the back side of the developer layer thickness regulating member when the developing device cartridge is attached or detached. , As well as partition members,
Since the developer intrusion prevention member is provided, even in such a case, the developer can be surely prevented from entering the back surface side of the developer layer thickness regulating member.

According to a ninth aspect of the present invention, there is provided an image forming apparatus according to any one of the first to sixth aspects of the invention, or the process cartridge according to the seventh aspect or the eighth aspect of the present invention. A developing device cartridge is provided.

According to the image forming apparatus of the ninth aspect, the developing device of any one of the first to sixth aspects, the process cartridge of the seventh aspect, or the eighth aspect of the present invention.
Since the developing device cartridge described above is provided, good image forming operation is performed without generating fog.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. First, an overview of the entire image forming apparatus according to the present embodiment will be described.

(Overview of Overall Image Forming Apparatus) FIG. 1 is a sectional view showing a schematic configuration of a laser beam printer 1 as an embodiment of the image forming apparatus of the present invention. In FIG. 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 that is pressed by a spring (not shown), a paper feeding roller 11, and a friction separating member 14. 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 sheet conveyance direction by the rotation of the sheet supply 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 composed of 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 that generates 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 which is driven to rotate. , A pair of lenses 42 and 4
5 and reflection mirrors 43, 44 and 46.

The developing device 50 includes a process cartridge 2
As shown in FIG. 2 which is an enlarged view of FIG. 2A, a toner storage chamber 52 as a developer chamber is formed in a case 51 as a developing device housing, and an agitator 53 is provided in the toner storage chamber 52.
In addition, the cleaning member 54 is provided rotatably around the rotation shaft 55. The toner accommodating chamber 52 accommodates a positively chargeable nonmagnetic one-component developer having electrical insulation. Further, light transmitting windows 56 are provided on side walls of the toner storage chamber 52 located on both ends of the rotation shaft 55. The photosensitive drum 2 in the toner storage chamber 52
On the 0 side, a developing chamber 57 for performing development by communicating with the toner storage chamber 52 through the opening A is formed, and a supply roller 58 and a developing roller 59 as a developer carrier are rotatably supported. 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.

A rib 51b as a partition member is provided between the layer thickness regulating blade 64 and the opening A to prevent the toner from moving to the back side of the layer thickness regulating blade 64. . Further, a rib sponge 117 as a developer entry preventing member is provided on the back side of the layer thickness regulating blade 64.
Is provided, and the rib sponge 117 is provided with a rib 51b.
It is attached so as to be in pressure contact with. In this way, the toner is reliably prevented from entering the back surface of the layer thickness regulating blade 64.

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.

As shown in FIGS. 10A to 10C, a layer thickness regulating blade 64 serving as a developer layer thickness regulating member has a support portion 64c made of iron or stainless steel.
, A thin plate-shaped leaf spring 64b made of phosphor bronze or stainless steel is attached, and a pressing member 6 made of silicone rubber is further placed on the leaf spring 64b.
4a is attached. Further, the rib sponge 117 has a leaf spring 64 as shown in FIG.
b is attached along the longitudinal direction. Note that FIG.
(C) is a view seen from the arrow A side shown in FIG. 11, that is, from the front side, and FIGS. 10 (A) and (B) are views seen from the opposite back side.

The support portion 64c is provided with a boss hole 115 shown in FIG.
And a screw hole 11 shown in FIG.
6 and attached to the case 51 by screwing. After that, the developing roller 59 is moved to the case 5.
1, the pressing member 64a is
Due to the elastic force of b and the elastic force of the silicone rubber itself, it comes into pressure contact with the peripheral surface of the developing roller 59. Thus, the thickness of the toner layer on the developing roller 59 is regulated to a desired value.

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 diameter of 6 μm to 10 μm and an average particle diameter 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.

Returning to FIG. 1, the transfer roller 21 is rotatably supported by a pivot and is made of a conductive elastic foam made of silicone rubber or urethane rubber. The transfer roller 21 moves the photosensitive drum 20 by the applied voltage.
The configuration is such that the upper toner image is reliably transferred to a sheet.

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 discharge roller 74 for transporting the paper are provided on the downstream side in the transport direction of the fixing unit 70, respectively, and a discharge tray 75 is provided on the downstream side of the paper discharge roller 74. ing.

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 detachably with respect to the process cartridge 2a (the process cartridge of claim 8) as a developing device cartridge.

In the laser beam printer 1 of the present embodiment as described above, the surface of the photosensitive drum 20 is
When the laser beam L modulated according to image information is emitted from the laser scanner unit 40, an electrostatic latent image is formed on the surface of the photosensitive 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 a 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, and is nipped and conveyed by the heating roller 71 and the pressing roller 72 of the fixing unit 70. 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.

(Seal Structure in Developing Apparatus) Next, a seal structure using a developer leakage preventing member in the developing apparatus 50 of the present embodiment will be described with reference to FIGS. I do.

FIGS. 3 (A), 4 (A), 5 (A), 6 (A), 7 (A), 12 (A), 13 (A),
16 is a partially cutaway perspective view showing a seal portion of a case 51 in the developing device 50. FIG. 3B,
FIGS. 4 (C), 5 (B), 6 (B), 7 (C), 9, 11, 12 (B), and 13 (C) are perspective views of the respective partially broken sections. It is a figure showing the seal part seen from the direction of arrow B shown in the figure. FIG. 4B is a diagram showing the seal portion viewed from the direction of arrow A shown in FIG. 4A, and FIG.
FIG. 8A is a front view showing the seal portion of the case 51 at a stage where the upper seal is attached, and FIG. 10A is a view showing the back side of the layer thickness regulating blade. FIG. 10B is a view of the layer thickness regulating blade to which the rib sponge is attached as viewed from the back side, and FIG.
FIG. 13C is a diagram of the thickness regulating blade viewed from the front side, and FIG.
13 (B) is a view showing the seal portion viewed from the direction of arrow A shown in FIG. 13 (A), FIG. 13 (D) is a cross-sectional view taken along line DD of FIG. 13 (C), and FIG. 14 is lubricating the Teflon felt seal. FIG. 15 is a plan view showing a lower film and the vicinity of a mounting portion thereof, showing a method of applying an agent.

First, in FIG. 3A, a hatched area is an area where a seal member described below is attached by a double-sided tape, and a side seal attachment area 100 along the circumferential direction of the developing roller 59 is provided. , Developing roller 5
9 is divided into a lower seal mounting area 101 along the longitudinal direction of the developing roller 59. Side seal mounting area 100 and lower seal mounting area 101
Is subjected to a degreasing treatment in order to enhance the adhesiveness of the double-sided tape.

The developing roller 59 is arranged so that its end face is close to the side face 51a of the developing roller accommodating portion of the case 51 shown in FIG. FIG. 3 (B)
The center point Q shown in FIG. 7 indicates the position of the rotation center axis of the developing roller 59. The supply roller 58 is attached to a supply roller housing provided at a position behind the developing roller housing, as indicated by a two-dot chain line in FIG.

Next, as shown in FIGS. 4A, 4B and 4C, the film 103 for attaching the upper side seal is formed.
To the case 51 using a double-sided tape. As will be described later, a blade side seal for preventing toner leakage from both ends is attached to the layer thickness regulating blade attached to the upper position of the developing roller 59, and the blade side seal is attached to the case 51 side. An upper side seal is attached to enhance the adhesion with the upper side. This upper side seal is attached so as to be superimposed on the film 103 shown in FIG. 4B, but if there is no film 103, the bonding area of the upper side seal to the case 51 is indicated by hatching in FIG. 4B. Only the region shown indicates lack of stability. Therefore,
In the present embodiment, the PET film 103 is
1 to secure the bonding area of the upper side seal.

Next, as shown in FIGS. 5A and 5B,
In order to prevent toner from leaking from both ends of the developing roller 59, side seals 104 constituting a base material of a developer leak preventing member at both ends are attached to the side seal attaching area 100 with a double-sided tape. The side seal 104 is formed of a urethane sponge (trade name: Poron, manufactured by Rogers INOAC) having relatively high rigidity among sponges, and is compressed when the developing roller 59 is attached so as to exert a predetermined pressing force. It has a certain thickness. With such a configuration, Teflon felt, which is the uppermost layer of the both-end developer leakage prevention member described below,
The developing roller 59 can be pressed with a predetermined pressing force.

Also, in the present embodiment, FIG.
As shown in (1), the side end surface of the supply roller 58 is configured to rub against the side end surface of the side seal 104, so that toner leakage from between the supply roller 58 and the side seal 104 is prevented.

Next, as shown in FIGS. 6A and 6B,
Adhesive surface of side seal 104 of case 51 and film 1
The edge seal 106 is attached from the stepped portion E formed between the adhesive surface 03 and the upper surface of the side seal 104. The edge seal 106 is formed of urethane sponge, and is adhered to the step portion E and the upper end surface of the side seal 104 by attaching a double-sided tape to the bottom surface. By providing such an edge seal 106, the lower end face of the upper side seal attached to the film 103 and the blade side seal attached to the layer thickness regulating blade, to which the double-sided tape is not attached, is brought into contact with the edge seal 106. Thus, a contact portion between the sponge and the sponge can be formed to reliably prevent the toner from leaking.

Next, as shown in FIGS. 7 (A), (B) and (C), the upper side seal 107 is attached to the film 103 in order to enhance the adhesion with the blade side seal described later.
And attached to the case 51 with double-sided tape. The upper side seal 107 is formed of urethane sponge, and is provided at a position where it contacts a blade side seal described later. With such a configuration, the contact portion between the upper side seal 107 and the blade side seal becomes a contact portion between the sponge and the sponge, so that toner leakage can be reliably prevented.

Next, as shown in FIGS. 8 and 9, the layer thickness regulating blade 64 is formed to extend in the longitudinal direction in order to prevent toner from leaking from an upper position behind the mounting portion of the layer thickness regulating blade 64. The mounted upper seal 108 is attached. The upper seal 108 is formed of urethane sponge. The upper seal 108 reliably prevents toner leakage due to toner spraying in the toner storage chamber or toner leakage when the developing device 50 is turned upside down.

Next, as shown in FIG. 10A, the back side blade side seal 111 is attached to the leaf spring 64b attached to the support portion 64c of the layer thickness regulating blade 64 with a double-sided tape. When the layer thickness regulating blade 64 is attached to the case 51, the leaf spring 64b receives a pressing force from the upper side seal 107 and the back side blade side seal 111 as shown in FIG. The side blade side seal 111 is a leaf spring 64
Since it has a width to press not only b but also the end of the pressing member 64a, the leaf spring 64b does not bend.
Therefore, it is possible to prevent toner leakage due to the bending of the leaf spring 64b. Also, the back side blade side seal 1
A double-sided tape is stuck on the surface of the eleventh plate spring 64b to be bonded, but the upper side seal 107 comes into pressure contact with the opposite surface as shown in FIG. Since the back side blade side seal 111 is formed of urethane sponge, the contact portion between the back side blade side seal 111 and the upper side seal 107 is a sponge-to-sponge contact portion. The lower end surface of the back side blade side seal 111 is in contact with the side edge seal 106 as shown in FIG. Therefore,
The contact portion between the back side blade side seal 111 and the side edge seal 106 is also a sponge-to-sponge contact portion. As described above, the boundary between the back side blade side seal 111 and other members is a contact portion between the sponge and the sponge except for the adhesive surface with the leaf spring 64b, thereby reliably preventing toner leakage. .

In this embodiment, FIG.
As shown in (B), a rib sponge 117 formed to extend in the longitudinal direction of the leaf spring 64b is attached to a region sandwiched between the two back side blade side seals 111 with a double-sided tape. The rib sponge 117 is formed of a urethane sponge thicker than the back side blade side seal 111. As already described with reference to FIG. 2, the developing chamber 57 of the case 51 is provided with a rib 51 b behind the layer thickness regulating blade 64, and the layer thickness regulating blade 64 is provided.
Is attached to the case 51, the rib sponge 117 comes into pressure contact with the rib 51b.

As shown in FIG. 2, the rib 51b has a size that covers substantially the entire back surface of the layer thickness regulating blade 64. You cannot enter the side. Moreover, FIG.
When the process cartridge 2a is correctly mounted on the laser beam printer 1 and the laser beam printer 1 is installed in a horizontal state, the rib 51b is mounted so that its surface is vertical. Have been. Therefore, the toner does not run on the surface of the rib 51b and does not hinder the circulation of the toner.

Further, the rib 51b and the thickness regulating blade 64
Is closed by the rib sponge 117 over the entire area in the longitudinal direction of the rib 51b, so that the toner does not enter through the gap.

Accordingly, even when the layer thickness regulating blade 64 is attached at an angle as shown in FIG. 2 and toner is easily deposited on the back side of the layer thickness regulating blade 64, as described above, the layer thickness regulating blade Since the intrusion of the toner into the rear surface side of the toner 64 is reliably prevented, the above-described accumulation of the toner does not occur. As a result, uncharged or insufficiently charged toner is not generated, so that fog can be reliably prevented.

Further, as shown in FIG. 10B, the position where the rib sponge 117 is attached is set so as to leave an interval of W1 from the lower end of the leaf spring 64b. That is, as shown in FIG. 2, it is not positioned directly behind the pressing member 64a. Therefore, the rib sponge 11
Even when the elastic member 7 is pressed against the ribs 51b by its elastic force, the pressing force of the pressing member 64a against the developing roller 59 can be prevented from fluctuating due to being directly affected by the elastic force. And a toner seal can be performed.

On the other hand, on the front side of the leaf spring 64b on which the pressing member 64a is provided, as shown in FIG. 10C, a front blade side seal 112 is provided on both sides so as to contact both ends of the pressing member 64a. Attached by tape.
The front blade side seal 112 is formed of urethane sponge. This front blade side seal 112
A Teflon felt, which will be described later, is attached on the top, and the thickness when the front side blade side seal 112 and the Teflon felt are combined, as shown in FIG. It is configured to be thicker than the pressing member 64a. With this configuration, even when the pressing member 64a is worn, the pressing force of the pressing member 64a at both ends on the developing roller 59 is not changed, and the toner from the pressing contact portion between the pressing member 64a and the developing roller 59 is not changed. Leakage can be reliably prevented.

Next, as shown in FIGS. 12A and 12B, toner leaks from the boundary between the lower seal mounting region 101 and the side seal mounting region 100, and the movable portion of the lower seal described later. In order to prevent toner from leaking from the gap with the lower seal mounting area 101, the lower side seal 105 is attached to the end of the lower seal mounting area 101 with a double-sided tape. Lower side seal 105
Is formed of a urethane sponge, and a double-sided tape is attached to the bottom surface of the lower side seal 105. The end face on the side seal 104 side is attached so as to overlap in a partial area W0 as shown in FIG. 12B, and the lower side seal 105 is brought into close contact with the side seal 104 by pressing.
In the present embodiment, the overlapping area W0 is set to about 2 mm.

Next, as shown in FIGS. 13 (A), 13 (B) and 13 (C), the Teflon felt 113 as the rubbing portion of the developer leakage preventing member at both ends is attached to the leaf spring of the layer thickness regulating blade 64. 64b, the front-side blade side seal 112, and the side-side seal mounting area 100 are mounted using double-sided tape. On the layer thickness regulating blade 64,
As shown in FIGS. 13B and 13C, the tip of the Teflon felt is attached to the leaf spring 64b, and the subsequent portion is attached so as to cover the front blade side seal 112. With this configuration, it is possible to reliably prevent toner from leaking from both ends of the pressing member 64a of the layer thickness regulating blade 64.

Particularly, in the present embodiment, as shown in FIG. 14, the brush 1 is placed on the Teflon felt sheet 113a in a state before the Teflon felt 113 is cut off individually.
18, after applying a lubricant in which a fluororesin and a fluorine oil are dispersed in a quick-drying solvent, the Teflon felt 113 shown in a strip shape in FIG. 14 is individually cut off from the Teflon felt sheet 113a, as described above. Attached to. As a result, the developing roller 59 and the Teflon felt 11
In addition to improving the effect of preventing toner leakage in the rubbing portion between the developing roller 59 and the developing roller 59, even when the developing roller 59 is rotationally driven, it is possible to improve the lubricity. Generation of abnormal noise can be reliably suppressed.

As an example of the lubricant, "HANAL FL-Z75" manufactured by Kanto Kasei Kogyo Co., Ltd. was used. The application amount was 20 ± 5 g per 100 Teflon felts 113. This Hanal FL-Z75 is
Hydrofluorocarbon is 80 as a volatile solvent.
９０90 wt%, and furthermore, fluorinated oil and polytetrafluoroethylene (PTFE) as a fluorinated resin and other components are contained in an amount of 10-20 wt%.

In this embodiment, FIG.
As shown in (B), (C), and (D), the Teflon felt 113 is configured to ride on the position on the side end surface side of the pressing member 64a and on the leaf spring 64b.
The Teflon felt hair is pressed against the pressing member 64a and the developing roller 5
As a result, no gap is formed between the pressing member 64 a and the developing roller 59.
As a result, toner leakage from between the pressing member 64a and the developing roller 59 can be reliably prevented. Further, as described above, by configuring the Teflon felt 113 to ride on the leaf spring 64b, the Teflon felt 113 moves together with the movement of the leaf spring 64b of the layer thickness regulating blade 64, and the layer thickness is increased. Regulator blade 64
Does not hinder the movement of the leaf spring 64b. Further, in this embodiment, as shown in FIGS. 13C and 13D, the portion on which the Teflon felt 113 rides is a side seal 1 as a base material of a developer leakage prevention member at both ends.
The front blade side seal 112 as a foamed elastic material layer formed of a sponge other than the sponge
And the Teflon felt 113, and is bonded to the leaf spring 64b and the Teflon felt 113 with a double-sided tape. As a result, the developing roller 5
Even if the Teflon felt 113 is pressed against the developing roller 59 with a sufficient pressing force so as to reliably prevent toner leakage from both ends of the front side 9, the repulsive force of this portion can be reduced by an appropriate amount of crushing. The seal 112 absorbs,
Developing roller 5 of pressing member 64a of layer thickness regulating blade 64
9 does not weaken on both ends of the developing roller 59.

Next, as shown in FIGS. 15 and 16, a lower film 114 is attached as a lower end developer leakage preventing member. As the lower film 114, a PET sheet or a urethane rubber film is used. In this embodiment, a PET sheet is used. The lower film 114 is attached to a part of the lower seal mounting area 101, a part of the front edge 51d of the case 51, and a part of the lower side seal 105 using a double-sided tape. As described above, the bonding surface of the lower film 114 is
Since not only the area 1 but also the area of the front edge 51d is included, it is hard to peel off. Accordingly, even when the pressing force between the developing roller 59, the lower film 114 and the Teflon felt 113 is increased to some extent, the peeling of the lower film 114 can be reliably prevented. Also, the lower film 11
As shown in FIGS. 15 and 16, both end portions 114 a of the 4 are formed obliquely with respect to the sticking reference line. As a result, a gap is formed between both ends 114a and Teflon felt 113, and the lower side seal 105 is exposed from the gap. Accordingly, the lower film 114 does not ride on the Teflon felt 113, and there is no gap between the developing roller 59 and the Teflon felt 113 due to a step. Can be reliably prevented.

As described above, in the developing device 50 of this embodiment, toner leakage from the upper portion, both ends, and the lower portion of the developing roller 59 can be reliably prevented.

In particular, in the present embodiment, as described above, the rib 51b and the rib sponge 117 can reliably prevent toner from entering the back side of the layer thickness regulating blade 64. No toner is deposited on the back side of the blade 64. As a result, the toner does not become insufficiently charged by accumulating on the back surface side of the layer thickness regulating blade 64, or does not generate uncharged toner, so that fog can be reliably prevented.

When the developing cartridge or the process cartridge is configured to be detachable from the laser beam printer as in this embodiment, the toner enters the back surface of the layer thickness regulating blade 64 at the time of detachment. However, as described above, since the rib sponge 117 is provided in addition to the rib 51b, even when the developing unit cartridge or the process cartridge is attached or detached, the toner can enter the back side of the layer thickness regulating blade 64. The fog can be reliably prevented, and fog can be prevented.

In this embodiment, the rib 51b is used.
Is formed in a flat plate shape, but the present invention is not limited to this, and may be formed in another shape or attached at a predetermined angle as long as the structure is such that the toner easily falls.

Further, in the present embodiment, the example in which the rib sponge 117 is adhered and attached to the layer thickness regulating blade 64 has been described, but the present invention is not limited to such a configuration, and the rib sponge 117 is attached to the rib 51b side. Rib sponge 11
7 may be bonded and attached.

In this embodiment, the layer thickness regulating blade 64 is provided with the pressing member 64a made of silicone rubber on the plate spring 64b. However, without providing the pressing member 64a, the end of the plate spring 64b is formed. The present invention can also be applied to a layer thickness regulating blade that is bent at about 90 degrees and abuts on the developing roller 59 at the curved portion. In that case, the pressing member of claim 1 corresponds to the curved portion.

In the above description, the developing device 5
0 has been described as an example in which the process cartridge 2a is detachably attached to the image forming apparatus main body, but the present invention is not limited to this.
Only the developing device 50 may be attached to and detached from the image forming apparatus main body, and a process cartridge (process cartridge according to claim 7) in which the process cartridge 2a and the developing device 50 are formed in an integral housing. It may be configured to be detachable from the image forming apparatus. Also,
The developing device 50 does not necessarily need to be detachable from the image forming apparatus, and may be a stationary type. If the present invention is applied to a developing device cartridge or a process cartridge,
This has the effect of reliably preventing toner leakage at the time of attachment / detachment. However, even in the case of a stationary type, it is possible to exhibit the effect of not contaminating the inside of the image forming apparatus main body with toner even if vibrations or the like occur. .

As described above, the present invention has been described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be made without departing from the gist of the present invention. Can easily be inferred.

[0076]

According to the first aspect of the present invention, the developing device has a shape or an angle between the back surface of the developer layer thickness regulating member and the developer accommodating chamber of the developing device. Since there are provided a partition member provided, and a developer entry preventing member made of a foamed elastic body provided so as to come into contact with both the back surface of the developer layer thickness regulating member and the partition member, the developer layer thickness regulating member is provided. Can reliably be prevented from entering the back surface of the toner, and fog can be reliably prevented.

According to the second aspect of the present invention, the developer intrusion preventing member is provided so as to be in contact with the rear surface of the developer layer thickness regulating member outside the region corresponding to the adhesive attachment of the pressing member on the rear surface. Therefore, it is possible to exhibit excellent layer thickness regulation and developer leakage prevention ability without changing the pressing force of the pressing member against the developer carrier.

According to the third aspect of the present invention, since the developer intrusion prevention member is attached to the back surface of the developer layer thickness regulating member by adhesion, the developer layer thickness regulating member is attached to the developing device. The developer intrusion preventing member can be brought into press contact with the partition member, and the toner can reliably be prevented from entering the back surface of the developer layer thickness regulating member, and fog can be reliably prevented.

According to the fourth aspect of the present invention, since the developer intrusion preventing member is attached to the partition member by adhesion, the developer layer thickness regulating member is attached to the developing device.
The developer intrusion prevention member can be brought into press contact with the developer layer thickness regulating member, and the toner can reliably be prevented from entering the back surface of the developer layer thickness regulating member, and fog can be surely prevented.

According to the developing device of the present invention, since the polymerized toner produced by the polymerization method is used as the developer, the developing operation with high fluidity and high definition can be performed. In addition, even if the fluidity is high, it is possible to reliably prevent the developer from entering the back surface side of the developer layer thickness regulating member, thereby preventing fog.

According to the sixth aspect of the present invention, even when a roller formed of a conductive elastic material is used as the developer carrier, the pressing force of the pressing member against the developer carrier is varied. Thus, the desired layer thickness regulating force and the ability to prevent developer leakage can be exhibited.

According to the process cartridge of the present invention, since the process cartridge detachably formed in the image forming apparatus is provided with the developing device of any one of claims 1 to 6, Even when the cartridge is attached or detached, it is possible to reliably prevent the developer from entering the back surface side of the developer layer thickness regulating member, thereby preventing fog.

According to the developing device cartridge of the present invention, the developing device of any one of the first to sixth aspects can be provided with:
Since it is detachably attached to the image forming apparatus or the process cartridge, even when the developer cartridge is attached or detached, it is possible to reliably prevent the developer from entering the back side of the developer layer thickness regulating member and to reduce fog. Can be prevented.

According to the image forming apparatus of the ninth aspect, the developing device of the first aspect, the process cartridge of the seventh aspect, or the eighth aspect of the invention.
Since the developing device cartridge described above is provided, good image forming operation can be performed without generating fog.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a schematic configuration of a developing device in the image forming apparatus of FIG.

3 (A) is a partially cutaway perspective view showing a seal portion of a developing device case before a seal member is attached, and FIG. 3 (B) is a seal seen from the direction of arrow B shown in FIG. 3 (A). It is a figure which shows a part.

4 (A) is a partially cutaway perspective view showing a seal portion of a developing device case when an upper side seal attaching film is attached, and FIG. 4 (B) is an arrow A shown in FIG. 4 (A); FIG. 4C is a view showing the seal portion viewed from the direction, and FIG.
It is a figure showing the seal part concerned seen from the arrow B direction shown to (A).

5A is a partially cutaway perspective view showing a seal portion of a developing device case when a side seal is attached, FIG.
FIG. 5B is a diagram showing the seal portion as viewed from the direction of arrow B shown in FIG.

6A is a partially cutaway perspective view showing a seal portion of a developing device case when an edge seal is attached, FIG.
FIG. 7B is a diagram showing the seal portion as viewed from the direction of arrow B shown in FIG.

FIG. 7A is a partially broken perspective view showing a seal portion of a developing device case when an upper side seal is attached;
FIG. 7B is a diagram showing the seal portion viewed from the direction of arrow A shown in FIG. 7A, and FIG. 7C is a diagram showing the seal portion viewed from the direction of arrow B shown in FIG. It is.

FIG. 8 is a front view showing a seal portion of the developing device case when an upper seal is attached.

FIG. 9 is a view showing a seal portion viewed from a direction of an arrow B shown in FIG. 8;

10A is a diagram of the layer thickness regulating blade as viewed from the back side, FIG. 10B is a diagram of the layer thickness regulating blade with the rib sponge attached thereto as viewed from the back side, and FIG. It is the figure which looked at the thickness regulation blade from the front side.

FIG. 11 is a view showing the seal portion as viewed in the direction of arrow B, similarly to FIG. 9;

12 (A) is a partially cutaway perspective view showing a seal portion of a developing device case when a lower side seal is attached, and FIG. 12 (B) is viewed from an arrow B direction shown in FIG. 12 (A). FIG. 3 is a diagram showing the seal portion.

13 (A) is a partially cutaway perspective view showing a seal portion of a developing device case when Teflon felt is attached, and FIG. 13 (B) is viewed from an arrow A direction shown in FIG. 13 (A). FIG. 13C is a diagram showing the seal portion, and FIG. 13C is a diagram showing the seal portion viewed from the direction of arrow B shown in FIG.
FIG. 14D is a sectional view taken along line DD of FIG.

FIG. 14 is a view showing a method of applying a lubricant containing a fluorine-based resin and a fluorine oil to a Teflon felt sheet.

FIG. 15 is a plan view showing the periphery of the lower film and its mounting portion.

FIG. 16 is a partially cutaway perspective view showing a seal portion of the case 51 on the opposite side to FIG. 13A when a lower film is attached.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser beam printer 50 Developing device 51 Case 51b Rib 52 Toner accommodating chamber 59 Developing roller 64 Layer thickness regulating blade 64a Pressing member 64b Leaf spring 100 Side side seal mounting area 101 Lower side seal mounting area 103 Upper side seal mounting film 104 Side Seal 105 Lower side seal 107 Upper side seal 108 Upper seal 110 Side edge seal 111 Back side blade side seal 112 Front side blade side seal 113 Teflon felt 114 Lower film 117 Rib sponge

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masahiro Ishii 15-1 Naeshiro-cho, Mizuho-ku, Nagoya-shi, Aichi F-term (reference) in Brother Industries, Ltd. 2H077 AA12 AB04 AD06 AD13 AD17 AD23 BA08 BA09 CA02 CA12 EA14 FA13 FA16 FA22

Claims (9)

[Claims] A developer carrier is rotatably disposed in an opening of a developing device housing for accommodating a developer, and a thin layer of the developer formed on the developer carrier is formed into an electrostatic latent image. A developing device that forms a visible image by facing each other, and is formed to extend in a longitudinal direction of the developer carrying member, and is formed on a peripheral surface of the developer carrying member by a pressing member provided on a surface portion. A developer layer thickness regulating member that forms a thin layer of developer; and a shape or an angle that allows the developer to drop between the back surface portion of the developer layer thickness regulating member and the developer accommodating chamber of the developing device. A partition member provided with: a developer entry prevention member made of a foamed elastic body provided so as to contact both the rear surface of the developer layer thickness regulating member and the partition member. And a developing device. 2. The method according to claim 1, wherein the developer intrusion prevention member is provided so as to come into contact with the rear surface of the developer layer thickness regulating member outside the region corresponding to the adhesive attachment of the pressing member on the rear surface. The developing device according to claim 1. 3. The developing device according to claim 1, wherein the developer intrusion prevention member is adhered and attached to a back surface of the developer layer thickness regulating member. 4. The apparatus according to claim 1, wherein the developer intrusion prevention member is attached to the partition member by adhesive.
Or the developing device according to 2. 5. The developing device according to claim 1, wherein the developer is a polymerized toner produced by a polymerization method. 6. The developer carrier according to claim 2, wherein the developer carrier is a roller formed of a conductive elastic body.
The developing device as described in the above. 7. A process cartridge detachably formed in an image forming apparatus, comprising: a carrier for the electrostatic latent image; and a developing device according to claim 1. A process cartridge characterized by the above-mentioned. 8. A developing device cartridge, wherein the developing device according to claim 1 is detachably mounted on an image forming apparatus or a process cartridge. 9. The developing device according to claim 1, or a process cartridge according to claim 7,
An image forming apparatus comprising the developing device cartridge according to claim 8.