JP3501018B2 - Developing device, process cartridge, developing device cartridge, and image forming apparatus - Google Patents

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 device for developing using a developer which is charged fine particles, a process cartridge, a developing device cartridge, and an image forming apparatus equipped with any one of them. Belong to.

[0002]

2. Description of the Related Art In a developing device in which toner, which is charged fine particles, is used as a developer and the toner is electrostatically adhered to an electrostatic latent image for development, there is a problem that the toner leaks from the developing device. is there. When the toner leaks from the developing device, the inside of the image forming apparatus main body equipped with this developing device becomes dirty, resulting in defective printing, and further, when the developing device is replaced, the worker's hands and clothes become dirty. There was something that happened.

In particular, a non-magnetic single component is used 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 carrying toner, and developing is carried out by making this thin layer face an electrostatic latent image. In the case of development, toner leakage easily occurs around the rotating developing roller.

Therefore, conventionally, a toner leakage preventing member is provided inside the developing device to prevent the toner leakage as described above. For example, around the developing roller, in order to prevent toner leakage from both ends of the developing roller, a toner leakage prevention member called a side seal is rubbed against the peripheral surfaces of both ends of the developing roller, and In order to prevent toner leakage from the gap between the developing roller formed below and the opening of the toner container, a toner leakage preventing member called a lower film is rubbed against the developing roller below the developing roller. . Further, in order to prevent the toner leakage 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. The regulation blade had a function as a toner leakage prevention member.

The side seal has a structure in which a sliding member made of Teflon felt is attached to urethane sponge. The urethane sponge is required to be sufficiently soft and have a small compression set. Teflon felt is used for both securing a pressing force and reducing a rotating torque.

The lower film is made of PET (polyethyle).
ne terephthalate) sheet or urethane rubber is used. Urethane rubber can be expected to be pressed softly, but since it is not stiff, it is necessary to press it from the back with a sponge or the like. Since the PET sheet is harder than the urethane rubber film, there is an advantage that it is not necessary to press the back surface with a sponge or the like and the assembly work is easier than the urethane rubber film.

[0007]

However, in the case of adopting this configuration, if a small amount of toner enters between the developing roller and the side seal, the developing toner and the side seal are damaged by the entering toner. There was a problem. Even if a small amount of toner first enters, the side seal is damaged, so that the degree of damage increases as printing is repeated, and toner leakage gradually increases.

In particular, when a polymerized toner having a spherical shape and excellent fluidity is used, the toner easily enters between the side seal and the developing roller, and further,
Toner leakage when the side seal or the like is damaged is more remarkable when the polymerized toner is used, and there is a problem in that the amount of toner that leaks is significantly increased.

In order to prevent such toner leakage, it is conceivable to increase the pressure of the side seals against the developing roller. However, if this is done, the rotational torque of the developing roller becomes too high and the motor is driven. There is a problem in that the load of is increased.

Further, when the polymerized toner is used, it is difficult to completely prevent the toner leakage even if the pressure is increased.

In particular, when a method of rubbing the supply roller against the developing roller is adopted in order to improve the supply of the toner to the developing roller, a large amount of toner is generated near the pressure contact portion between the supply roller and the developing roller. There is a problem in that the toner is likely to collect, the toner density is increased, and the toner easily enters between the side seal and the developing roller.

Therefore, the present invention can solve such a problem and reliably prevent the toner leakage from the sliding portion between the developing roller and the side seal even when the superposed toner and the supply roller are used. An object is to provide a developing device, a process cartridge, a developing device cartridge, and an image forming apparatus.

[0013]

According to a first aspect of the present invention, in order to solve the above-mentioned problems, a developer carrier is rotatably arranged in an opening of a developer housing for containing the developer. ,
A developing device for forming a visible image by causing a thin layer of the developer formed on the developer carrier to face an electrostatic latent image, wherein the developing device housing has openings near both ends in the longitudinal direction. Both ends of the developer leakage prevention member provided so as to rub against the peripheral surfaces of both ends of the developer carrying member, and the back surface of the sliding face of the both ends developer leakage preventing member with the developer carrying member. A sheet-like member that is provided at a position and that covers the sliding-leakage boundary portion between the developer leakage-preventing member and the developer-carrying member and the periphery of the sliding-rubbing boundary portion, and the sheet-shaped member is the back surface It is characterized in that it is provided so as to project from the position toward the central portion side in the longitudinal direction of the developing device housing opening.

According to the developing device of the present invention, the developer carrying member carries and conveys the developer while rotating, and the developer carrying member is provided near both ends of the developing device housing opening in the longitudinal direction. Since the developer leakage preventing members at both ends are provided so as to rub against the peripheral surfaces of both ends, the developer leakage from both ends is prevented. Moreover, a sheet-like member is provided at the rear position of the sliding surface of the developer leakage prevention member at both ends with the developer carrying member, and the sheet-like member is provided from the rear position in the longitudinal direction of the developing device housing opening. It was projected to the center side. As a result, since the sliding contact boundary portion between the developer leakage preventing member at both ends and the developer carrying member and the periphery of the sliding contact boundary portion are covered with the sheet-like member, the developer leakage preventing member at both end portions and the developing member are prevented from developing. The developer density at the sliding contact portion with the agent carrier and the periphery of the sliding contact portion decreases, and the developer enters the sliding contact portion between the developer leakage prevention member and the developer carrier at both ends. There is no. As a result, it is possible to reliably prevent the developer from leaking from the rubbing portion.

In order to solve the above-mentioned problems, the developing device according to a second aspect is the developing device according to the first aspect, in which the developer leakage preventing members at both ends are mounted on the developing device casing. And a rubbing portion that is mounted on the base material portion and rubs against the developer carrying member, and the sheet-shaped member is sandwiched between the base material portion and the rubbing portion. Is characterized by.

According to the developing device of the second aspect, the rubbing portions of the developer leakage preventing members at both ends are pressed by the base member attached to the developing device housing and rub against the developer carrier. Therefore, contact the developer carrier without forming a gap,
Surely prevent developer leakage. Moreover, since the sheet-shaped member is sandwiched between the base material portion and the rubbing portion,
The rubbing boundary portion between the rubbing portion and the developer carrying member and the periphery of the rubbing boundary portion are covered with the sheet-shaped member.
As a result, the developer density in the rubbing boundary portion and the periphery of the rubbing boundary portion is reduced, the developer does not enter between the rubbing portion and the developer carrier, and the developer leaks. Is reliably prevented.

In order to solve the above-mentioned problems, a developing device according to a third aspect of the present invention is the developing device according to the first or second aspect, wherein the developing device is rotatably arranged while sliding on the developer carrier. A developer transport supply body made of a foamed elastic body for transporting the developer to the carrier is further provided, and the projecting portion of the sheet-shaped member is provided between the developer carrier and the developer transport supply body. It is characterized by being sandwiched.

According to the third aspect of the present invention, the developer conveying / supplying member made of the foamed elastic body is pressed against the developer carrying member to rotate while rubbing to convey the developer to the developer carrying member. Supply. Therefore, a large amount of developer is supplied to the pressure contact portion between the developer transport supply member and the developer support member, and the developer density at the pressure contact portion increases. However, since the projecting portion of the sheet-shaped member is sandwiched between the developer carrying member and the developer conveying / supplying member, the developer in the pressure contact portion exceeds the sheet-shaped member and the developer at both ends is developer. The developer is not conveyed to the sliding friction boundary portion between the leak prevention member and the developer carrier and the periphery of the sliding friction boundary portion, and the developer density around the sliding friction boundary portion and the sliding friction boundary portion. Is reduced. As a result, the developer does not enter the sliding contact portion between the developer leakage prevention member at both ends and the developer carrier, and the developer leakage from the sliding contact portion is reliably prevented.

In order to solve the above problems, a developing device according to a fourth aspect of the present invention is the developing device according to any one of the first to third aspects, wherein the sheet-shaped member is made of resin. And

According to the developing device of the fourth aspect, since the sheet-shaped member is made of resin, it has appropriate hardness, reliably prevents the developer from entering, and is appropriately deformed. It becomes easy to make the shape along the peripheral surface of the developer carrying member.

In order to solve the above problems, the developing device according to a fifth aspect is the developing device according to the fourth aspect, wherein the sheet-shaped member is formed of PET.

According to the developing device of the fifth aspect, since the sheet-shaped member is made of PET, it has appropriate hardness, reliably prevents the developer from entering, and is appropriately deformed. It becomes easy to make the shape along the peripheral surface of the developer carrying member.

In order to solve the above-mentioned problems, the developing device according to a sixth aspect of the present invention is the developing device according to any one of the first to fifth aspects, wherein the sheet-shaped member has a longitudinal direction of the developer carrying member. It is characterized in that a notch along the is provided.

According to the developing device of the sixth aspect, since the notch is provided in the sheet-like member along the longitudinal direction of the developer carrying member, even when a load accompanying the rotation of the developer carrying member is received. The sheet-shaped member itself is not broken.

In order to solve the above-mentioned problems, a developing device according to a seventh aspect of the present invention is the developing device according to any one of the first to sixth aspects, wherein the sheet-shaped member is a developer leakage preventing member at both ends. The length of the portion projecting toward the central portion in the longitudinal direction of the developing device housing opening from the sliding contact with the developer carrying member along the longitudinal direction is 1 mm or more and 4 mm.
It is characterized by the following.

According to a seventh aspect of the present invention, in the sheet-shaped portion, the longitudinal direction of the opening of the housing of the developing device is larger than the sliding boundary between the developer leakage prevention member at both ends and the developer carrier. Since the length of the projecting portion along the longitudinal direction is set to 1 mm or more, the amount of the developer exceeding the projecting portion is reliably reduced to prevent the developer from leaking. Moreover, since the length of the protruding portion along the longitudinal direction is set to 4 mm or less, the convection of the developer is not deteriorated in the vicinity of the tip portion of the protruding portion, and the toner deterioration is prevented.

In order to solve the above problems, the developing device according to claim 8 is the developing device according to any one of claims 1 to 7, wherein the developer is a polymerized toner produced by a polymerization method. It is characterized by

According to the developing device of the eighth aspect, since the polymerized toner produced by the polymerization method is used as the developer, the fluidity is high and the developer is liable to leak, but as described above, the sheet is used. The toner density does not cause toner leakage because the developer density at and around the sliding frictional boundary between the developer leakage prevention member and the developer carrying member is reduced by the shaped member.

The process cartridge according to claim 9 is
In order to solve the above problems, a process cartridge detachably attached to an image forming apparatus, wherein the electrostatic latent image carrier is provided, and the developing device according to any one of claims 1 to 8. It is characterized by having.

According to the process cartridge of the ninth aspect, the process cartridge detachably formed with respect to the image forming apparatus is provided with the developing device of any one of the first to eighth aspects. Even when the cartridge is attached or detached, the developer leakage is surely prevented.

A developing device cartridge according to a tenth aspect is
In order to solve the above-mentioned problems, the developing device according to any one of claims 1 to 8 is formed so as to be attachable to and detachable from an image forming apparatus or a process cartridge.

According to the developing device cartridge of the tenth aspect, the developing device of any one of the first to eighth aspects is detachably formed with respect to the image forming apparatus or the process cartridge. The developer leakage is surely prevented even when attaching and detaching.

In order to solve the above problems, the image forming apparatus according to claim 11 is the developing device according to any one of claims 1 to 8, the process cartridge according to claim 9, or the process cartridge according to claim 10. A developing device cartridge is provided.

According to the image forming apparatus of claim 11,
Since the developing device according to any one of claims 1 to 8 or the process cartridge according to claim 9 or the developing device cartridge according to claim 10 is provided, developer leakage does not occur and the inside of the image forming apparatus main body is prevented. Is not contaminated by the developer.

[0035]

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 this embodiment will be described.

(Outline of Entire 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, a laser beam printer 1 is provided with a feeder unit (not shown) for feeding a sheet 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 feed roller 11, and a friction separating member 14. The paper pressing plate 10 presses the paper against the paper feed roller 11, and the paper feed roller 11 Is rotated to separate the uppermost paper between the paper feed roller 11 and the friction separating member 14, and the paper is supplied at a predetermined timing.

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

The photosensitive drum 20 is made of a positively chargeable material, for example, an organic photoreceptor having a positively chargeable polycarbonate as a main component. Specifically, the photosensitive drum 20 has, for example, a cylindrical cylindrical sleeve made of aluminum as a main body, and has a predetermined thickness (for example, about 20 μm) in which a photoconductive resin is dispersed in polycarbonate on the 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 rotationally driven in the direction of the arrow by a driving unit (not shown).

The charger 30 is composed of, 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.

In the developing device 50, a toner accommodating chamber 52 as a developer chamber is formed in a case 51 as a developing device housing, and an agitator 53 and a cleaning member 54 are provided in the toner accommodating chamber 52 as a rotating shaft 55. It is rotatably installed around. The toner containing chamber 52 contains toner as a positively charging non-magnetic one-component developer having electrical insulation. Further, the rotary shaft 55 of the toner storage chamber 52
Light-transmitting windows 56 are provided on the side walls located on both ends. Further, on the photosensitive drum 20 side of the toner accommodating chamber 52, a developing chamber 57 for communicating with the toner accommodating chamber 52 by the opening portion A for performing development is formed, and a supply roller 58 and a developing roller 59 as a developer carrier rotate. Be pivoted as possible.
The toner on the developing roller 59 is regulated to a predetermined layer thickness by a layer thickness regulating blade 64 having a thin plate-like elasticity, and is provided for development.

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

Further, in the supply roller 58 as a developer transport supply body, a cylindrical base material made of urethane rubber sponge, which is a conductive foam elastic body, is formed on a core metal made of stainless steel or the like. It is a roller and is arranged so as to press and contact the developing roller 59 by the elastic force of the urethane rubber sponge. In addition to this, as the supply roller 58, an appropriate member such as a conductive silicone rubber foam can be used.

The toner accommodated in the toner accommodating chamber 52 is a non-charged non-magnetic one-component developer having a positive charging property. Styrene-acrylic resin formed into a spherical shape by the suspension polymerization method, carbon black or the like. It has toner mother particles having a particle diameter of 6 μm to 10 μm and an average particle diameter of 8 μm, which is obtained by adding a well-known colorant and a charge control agent such as nigrosine, triphenylmethane, and a quaternary ammonium salt. The toner is formed by adding silica as an external additive to the surface of the toner mother particles.

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

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

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

The photosensitive drum 20, the transfer roller 21, the charger 30, and the developing device 50 described above are housed in a drum cartridge 2a, and the drum cartridge 2a is detachably attached to the laser beam printer 1. It is provided. Further, the developing device 50 is detachably provided as a developing device cartridge with respect to the drum cartridge 2a (process cartridge of claim 10).

In the laser beam printer 1 of this embodiment as described above, the surface of the photosensitive drum 20 is the charger 30.
When the laser beam L is uniformly charged by the laser scanner unit 40 and is modulated by the laser scanner unit 40 according to the image information, an electrostatic latent image is formed on the surface of the photosensitive drum 20.
The electrostatic latent image is visualized with toner by the developing device 50, and the visible image formed on the photosensitive drum 20 is conveyed to the transfer position by the photosensitive drum 20. At the transfer position, the paper is supplied through the paper feed roller 11 and the registration rollers 12 and 13, and the visible image is transferred onto 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, and 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. It Then, the sheet is ejected to the sheet ejection tray 75 above the laser beam printer 1 by the pair of conveyance rollers 73 and the sheet ejection roller 74, and the image forming operation is completed.

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

FIG. 2A, FIG. 3A, FIG. 4A, FIG. 5A, FIG. 6A, FIG. 7A, FIG. 8A, FIG.
1 (A), FIG. 12 and FIG. 14 (A) show the developing device 50.
3 is a partially cutaway perspective view showing a seal portion of a case 51 in FIG. In addition, FIG. 2B, FIG. 3C, FIG. 4C, FIG. 5B, FIG. 6B, FIG. 7B, FIG. 8C, and FIG.
1 (B) and FIG. 14 (C) are views showing the seal portion viewed from the direction of arrow B shown in the partially cutaway perspective views. 3B is a sectional view taken along the line CC of FIG.
8B is a diagram showing the seal portion viewed from the direction of arrow A shown in FIG. 4A, FIG. 8B is a diagram showing the seal portion viewed from the direction of arrow A shown in FIG. Is a front view showing the seal portion of the case 51 at the stage where the upper seal is attached, FIG. 10 is a view showing the seal portion viewed from the direction of arrow B shown in FIG. 9, and FIG. FIG. 13 (B) is a view of the layer thickness regulating blade from the front side, FIG. 13 (C) is a view showing a sealing portion as viewed in the direction of arrow B, similar to FIG. 11 (B), and FIG. (B) is FIG. 14 (A)
14 is a view showing the seal portion viewed from the direction of arrow A shown in FIG.
14D is a cross-sectional view taken along the line DD of FIG. 14C, FIG.
Is a plan view showing the lower film and the periphery of its mounting portion,
FIG. 15B is a view showing the adhesive surface of the lower film, FIG.
14A is a partially cutaway perspective view showing the seal portion of the case 51 on the side opposite to FIG. 14A, and FIG. 16B is FIG. 14C.
It is a figure which shows the seal part seen from the arrow B direction like this.

First, in FIG. 2A, a shaded 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. , Developing roller 5
It is divided into a lower seal attachment region 101 along the longitudinal direction of the developing roller 59 at a lower position of 9. 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 such that its end surface portion is close to the side surface portion 51a in the developing roller accommodating portion of the case 51 shown in FIG. 2 (A). Figure 2 (B)
The central point Q shown in indicates the position of the central axis of rotation of the developing roller 59. Further, the supply roller 58 is attached to a supply roller accommodating portion provided at a rear position of the developing roller accommodating portion as shown by a two-dot chain line in FIG.

Next, as shown in FIGS. 3A, 3B, and 3C, the end surface of the bottom surface portion 51b of the developing roller accommodating portion following the lower seal mounting area 101 on the side seal mounting area 100 side. The side edge seal 102 is attached to the side surface seal attachment area 1 with a double-sided tape.
It is adhesively attached to 00. The double-sided tape is attached to the bottom surface of the side edge seal 102, and the side edge seal 10
The end surface of No. 2 is pressed against the end surface 51c of the bottom surface portion 51b on the side seal attachment region 100 side to be brought into close contact therewith. As shown in FIG. 3B, the side-side seal attachment region 100 has a bottom surface portion 51 in consideration of the thickness of a side seal described later.
It is formed at a position lower than b, and a step portion having an end face 51c is formed between the bottom surface portion 51b and the side seal attachment region 100. Side seal installation area 1
00 is the side seal 10 as indicated by the dotted line in FIG.
4 is attached, the end face 51c becomes the side seal 10
4 will be in contact with the end face of the side seal 104
Since urethane sponge having a relatively high rigidity is used as the sponge, the adhesiveness with the resin forming the case 51 is weakened, and the end surface 51c and the side seal 104 are weakened.
The toner invades the contact portion with the end surface of the sheet, and the toner leaks. The toner not only enters the bottom surface portion 51b but also enters from the supply roller housing portion. Therefore, in this embodiment, the side edge seal 102 formed of a sponge softer than urethane sponge is brought into close contact with the end surface 51c to reliably prevent such toner from entering.

Next, as shown in FIGS. 4A, 4B, and 4C, the film 103 for attaching the upper side seal is attached.
Is attached to the case 51 with double-sided tape. The layer thickness regulating blade 64 is provided with blade side seals for preventing toner leakage from both end directions, and the case 51 side is provided with an upper side seal for enhancing adhesion with the blade side seals. It is attached. The upper side seal is attached so as to overlap with the film 103 shown in FIG. 4B. If the film 103 is not provided, the adhesive region of the upper side seal with respect to the case 51 is hatched in FIG. 4B. Only the area shown will be lacking in stability. Therefore,
In the present embodiment, the PET film 103 is used for the case 5
By attaching it to No. 1, the bonding area of this upper side seal is secured.

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

Further, in the present embodiment, FIG.
As shown in FIG. 5, the side end surface of the supply roller 58 is rubbed against the side end surface of the side seal 104 to prevent toner leakage from between the supply roller 58 and the side seal 104.

Next, as shown in FIGS. 6A and 6B,
In order to prevent toner leakage from the boundary between the lower seal mounting area 101 and the side seal mounting area 100, and to prevent toner leakage from the gap between the lower seal mounting area 101 and the movable part of the lower seal, which will be described later, Attach the side seal 105 to the lower seal attachment area 10 with double-sided tape.
Attach to the end of 1. The lower side seal 105 is made of soft urethane sponge, and the double-sided tape is attached to the bottom surface of the lower side seal 105. The end surface on the side seal 104 side is attached so as to overlap in a partial region W0 as shown in FIG. 6B, and the lower side seal 105 is pressed and brought into close contact with the side seal 104.
In this embodiment, the overlapping area W0 is set to about 2 mm.

Next, as shown in FIGS. 7A and 7B,
Adhesive surface of the side seal 104 of the case 51 and the film 1
The edge seal 106 is attached to the upper end surface of the side seal 104 from the step E formed between the edge seal 106 and the bonding surface of the side seal 03. The edge seal 106 is made of a soft urethane sponge, and is bonded to the step E and the upper end surface of the side seal 104 by attaching a double-sided tape to the bottom surface. By providing the edge seal 106 as described above, the lower side surface of the upper side seal attached to the film 103 and the double-sided tape of the blade side seal attached to the layer thickness regulating blade, which is not attached, are brought into contact with the edge seal 106. Therefore, it is possible to reliably prevent toner leakage by forming a contact portion between the sponges.

Next, as shown in FIGS. 8 (A), 8 (B) and 8 (C), the upper side seal 107 is covered with the film 103 in order to improve the adhesion with the blade side seal described later.
And the case 51 with double-sided tape. The upper side seal 107 is also formed of a soft urethane sponge, and is provided at a position where it comes into contact with a blade side seal described later. With this configuration, the contact portion between the upper side seal 107 and the blade side seal becomes a contact portion between sponges, and toner leakage can be reliably prevented.

Next, as shown in FIGS. 9 and 10, in order to prevent toner leakage from the upper position on the back side of the mounting portion of the layer thickness regulating blade 64, the layer thickness regulating blade 64 is formed so as to extend in the longitudinal direction. The upper seal 108 is attached. The upper seal 108 is formed of soft urethane sponge. With this upper seal 108,
It is possible to reliably prevent the toner leakage due to the toner that is sprayed in the toner storage chamber or the toner leakage when the developing device 50 is turned upside down.

Next, as shown in FIGS. 11A and 11B, the intermediate layer film 109 as a sheet-like member constituting the intermediate layer of the developer leakage prevention member at both ends is attached on the side seal 104. . The film 109 is made of PET, and the side seal 104 is made of double-sided tape.
Pasted on. The intermediate layer film 109 is shown in FIG.
As shown in (A), the side seal 104 has a width wider than that of the side seal 104, and a protruding portion whose end portion protrudes toward the center of the case 51 is formed. With this configuration, the toner density in the vicinity of the pressure contact portion between the Teflon felt and the developing roller mounted on the intermediate layer film 109 can be reduced, and the toner pressure to the pressure contact portion is reduced, as will be described later. be able to. As a result, toner leakage can be reliably prevented without increasing the pressing force of the side seal 104 on the developing roller 59 more than necessary.

In particular, in this embodiment, as shown in FIG. 11A, the supply roller 58 is shorter than the length of the developing roller 59, and as shown in FIG. 5A or FIG. Since the side end surface of the roller 58 is configured to rub against the side end surface of the side seal 104, unnecessary toner leakage from the contact portion between the side end surface of the supply roller 58 and the side end surface of the side seal 104 is prevented. Although, the supply roller 58
Since a large amount of toner is conveyed to the pressure-contacting portion between the developing roller 59 and the developing roller 59, the toner density around the pressure-contacting portion becomes extremely high.
As a result, the side end surface of the supply roller 58 and the side seal 10
The toner density also becomes high in the vicinity of the sliding contact portion with the side end surface of No. 4.

However, in the present embodiment, since the end portion of the intermediate layer film 109 is configured to protrude toward the central portion of the case 51, the toner around the sliding portion exceeds the intermediate layer film 109 and is developed. It is possible to reduce coming to the roller 59 side.

Further, as shown in FIG. 11A, a cut portion 109a is provided in the protruding portion of the intermediate layer film 109 along the longitudinal direction of the developing roller 59 from the central portion side of the case 51. Developing roller 59 and supply roller 5
The intermediate layer film 109 is prevented from being broken by the deformation caused by the load accompanying the rotation of 8.

That is, the intermediate layer film 109 is used for the case 5
By being configured so as to project toward the central portion of 1, the projecting portion is sandwiched between the developing roller 59 and the supply roller 58. Since Teflon felt is provided on the intermediate layer film 109 as will be described later, a minute gap corresponding to the thickness of the Teflon felt exists between the developing roller 59 and the intermediate layer film 109. However, since the supply roller 58 is pressed by the protruding portion of the intermediate layer film 109, the intermediate layer film 10 is pressed.
The projecting portion of 9 comes into contact with the developing roller 59, though it is slightly. Therefore, the protruding portion of the intermediate layer film 109 is sandwiched between the developing roller 59 and the supply roller 58, and is deformed as the developing roller 59 and the supply roller 58 rotate.

However, by providing the cut portion 109a in the intermediate layer film 109 as in the present embodiment, even if the intermediate layer film 109 is deformed by the rotation of the developing roller 59 and the supply roller 58, it is not broken. .

Next, as shown in FIG. 12, the side edge seal 110 is attached to the upper portion of the intermediate layer film 109 using a double-sided tape. This side edge seal 110
Is formed of a sponge, which prevents a gap from being formed between the sheet metal of the layer thickness regulating blade 64 described later and the intermediate layer film 109, and prevents toner leakage.

Next, as shown in FIG. 13A, the support portion 64 made of iron or stainless steel of the layer thickness regulating blade 64.
The back side blade side seal 111 is attached to the sheet metal 64b made of phosphor bronze or stainless steel attached to c by double-sided tape. Here, the surface on which the pressure contact member 64a is provided is the front surface of the sheet metal 64b, and the surface on the opposite side is the back surface of the sheet metal 64b. Back side blade side seal 1 along the longitudinal direction of the layer thickness regulating blade 64
The lateral length W1 of 11 is formed wider than the distance W2 from the side end of the sheet metal 64b to the side end of the pressure contact member 64a, and from the side end of the sheet metal 64b to the end of the pressure contact member 64a. It covers up to the corresponding position. When the layer thickness regulating blade 64 is attached to the case 51, the sheet metal 64b receives a pressing force from the upper side seal 107 and the back side blade side seal 111 as shown in FIG. By providing the blade side seal 111 in the area as described above, not only the sheet metal 64b but also the end portion of the pressure contact member 64a is pressed, and the sheet metal 64b is not bent. Therefore, it is possible to prevent toner leakage due to the bending of the metal plate 64b. Also,
The length H1 in the vertical direction of the back surface side blade side seal 111 along the lateral direction of the layer thickness regulating blade 64 is defined by the sheet metal 64.
The length b covers the entire area of the sheet metal 64b in the lateral direction. The double-sided tape is attached to the back surface of the back surface side blade side seal 111, and the front surface is pressed against and contacts the upper side seal 107 as shown in FIG. Since the back surface side blade side seal 111 is formed of soft urethane sponge, the contact portion between the back surface side blade side seal 111 and the upper side seal 107 is a contact portion between the sponge and the sponge. Also,
The lower end surface of the back side blade side seal 111 is shown in FIG.
It is in contact with the side edge seal 106 as shown in FIG. Therefore, the contact portion between the back surface side blade side seal 111 and the side edge seal 106 is also a contact portion between sponges. As described above, the boundary portion between the back side blade side seal 111 and other members is the contact portion between the sponge and the sponge except for the bonding surface with the sheet metal 64b, and the toner leakage is surely prevented.

On the other hand, on the front side of the sheet metal 64b on which the pressure contact member 64a is provided, as shown in FIG. 13 (B), the front side blade side seal 112 is attached to the double-sided tape so as to contact both ends of the pressure contact member 64a. It is installed by. The front blade side seal 112 is made of soft urethane sponge. A Teflon felt, which will be described later, is attached on the front side blade side seal 112. The thickness when the front side blade side seal 112 and the Teflon felt are combined is as shown in FIG.
As shown in FIG. 7, the thickness is made thicker than the pressure contact member 64a in consideration of a certain amount of crushing. With this configuration, even when the pressure contact member 64a is worn, the pressing force of the pressure contact member 64a on both end sides against the developing roller 59 is not changed, and the toner from the pressure contact portion between the pressure contact member 64a and the developing roller 59 is not changed. Leakage can be reliably prevented.

Next, as shown in FIGS. 14A, 14B, and 14C, the Teflon felt 113 forming the uppermost layer of the developer leakage prevention member at both ends is attached to the sheet metal 64b of the layer thickness regulating blade 64. , Front blade side seal 112, intermediate layer film 109, and side seal attachment area 100
Attach using double-sided tape. On the layer thickness regulating blade 64, as shown in FIGS. 14 (B) and 14 (C), the tip of the Teflon felt is attached to the sheet metal 64b, and the portion subsequent thereto is attached so as to cover the front side blade side seal 112. Make a mark. With this configuration, the pressure contact member 6 of the layer thickness regulating blade 64
It is possible to reliably prevent the toner from leaking from both ends of 4a. Further, since the Teflon felt 113 moves together with the movement of the sheet metal 64b of the layer thickness regulating blade 64, the leakage of toner is surely prevented and the movement of the sheet metal 64b of the layer thickness regulating blade 64 is not obstructed. Also,
Since the Teflon felt 113 has a low frictional resistance with respect to the developing roller 59, the rotational torque of the developing roller 59 can be reduced.

In particular, in the present embodiment, the intermediate layer film 109 is attached to the back side of the Teflon felt 113, and the end portion of the intermediate layer film 109 is projected toward the central portion side in the longitudinal direction of the case 51. Therefore, even if a large amount of toner is supplied to the pressure contact portion between the supply roller 58 and the developing roller 59 and the toner density becomes high, the toner is blocked by the intermediate layer film 109 and the Teflon felt 11
The amount of toner that reaches the surface of the developing roller 59 that is in contact with the developing roller 59 is significantly reduced. Therefore, the toner does not enter between the Teflon felt 113 and the developing roller 59, and the toner leakage is surely prevented.

Next, FIG. 15 (A), FIG. 16 (A),
As shown in (B), a lower film 114 is attached as a lower end developer leakage preventing member. Lower film 11
For 4, a PET sheet or a urethane rubber film is used. In this embodiment, a PET sheet is used. The lower film 114, as shown by the diagonal lines in FIG.
A part of the lower seal mounting area 101, a part of the front edge portion 51d of the case 51, and a part of the lower side seal 105 are attached using a double-sided tape. in this way,
Since the adhesive surface of the lower film 114 includes not only the lower seal attachment region 101 but also the region of the width W3 and the height H2 of the front edge portion 51d, it is difficult to peel off. Therefore, even if the pressing force of the developing roller 59, the lower film 114, and the Teflon felt 113 is increased to some extent, the lower film 114 can be reliably prevented from peeling off. Further, both ends of the lower film 114 are shown in FIG.
As shown in (B) and FIG. 16 (A), the Teflon felt 113 is mounted on top. With this configuration, when the developing roller 59 is mounted, the lower film 114 is pressed against the Teflon felt 113 side by the developing roller 59, and the gap between the Teflon felt 113 and the lower film 114 is eliminated.
It is possible to reliably prevent the toner from leaking from the contact portion between the Teflon felt 113 and the lower film 114.

As described above, in the developing device 50 of the present embodiment, it is possible to reliably prevent toner leakage from the upper portion, both end portions, and the lower portion of the developing roller 59,
Particularly, since the intermediate layer film 109 is attached to the back surface side of the Teflon felt 113 and the end portion of the intermediate layer film 109 is projected toward the central portion side in the longitudinal direction of the case 51, the Teflon felt 113 of the toner and the developing roller 59.
It is possible to reliably prevent the entry of the toner into the rubbing portion, and to reliably prevent toner leakage from the rubbing portion. When a polymerized toner having a fine particle diameter and high fluidity is used as in the present embodiment, toner leakage can be surely prevented, which is extremely effective.

As a result, the pressing force of the side seal 104 and the Teflon felt 113 against the developing roller 59 does not have to be increased more than necessary, so that the load on the motor can be reduced.

In the present embodiment, the amount of protrusion of the end portion of the intermediate layer film 109 was changed with reference to the side end surface of the side seal 104, and the difference in the toner leakage prevention effect was confirmed by experiments. As a result, when the amount of protrusion is less than 1 mm from the side end surface of the side seal 104, the toner leakage prevention effect is low and some toner leakage occurs.
On the other hand, when the protruding portion exceeds 4 mm, the convection of the toner is significantly deteriorated at the end portion of the protruding portion, the deterioration of the toner is promoted, and the print fog occurs on the end portion side of the paper. From these results, it was found that the protrusion length of the intermediate layer film 109 is preferably 1 mm or more and 4 mm or less based on the side end surface of the side seal 104. It was confirmed that 3 mm was particularly suitable.

When the relationship with the maximum print width (paper width) was examined, it was found that the protruding portion at the end of the intermediate layer film 109 was
It has been found that a length that does not enter the maximum print width (paper width) area is appropriate. When the protruding portion at the end of the intermediate layer film 109 entered the maximum print width (paper width) region, it was confirmed that printing was defective.

In the present embodiment, the resin sheet is used as the material of the intermediate layer film 109. However, since the resin sheet has an appropriate hardness, the rigidity of the resin sheet itself is high. Thus, the flatness of the toner blocking portion can be maintained to some extent, and the toner can be appropriately deformed to facilitate the assembling.

In the present invention, the intermediate layer film 109 is not limited to the resin sheet, but may be a urethane sheet or Teflon felt.

Further, in the above-described embodiment, an example in which the developer leakage preventing member on both end sides has a two-layer structure of a side seal and Teflon felt, and an intermediate layer film as a sheet-like member is provided in the intermediate layer thereof is described. However, the present invention is not limited to this, and in the case where the developer leakage prevention member at both ends has a one-layer structure in which the side seal is attached to the developer housing, the developer housing and the side seal are A sheet-shaped member may be provided between them.

Further, the length of the supply roller is set such that the side end surface of the supply roller rubs against the side end surface of the side seal. However, the present invention is not limited to this, and the side of the supply roller is the same. The length may be such that there is a gap between the end surface and the side end surface of the side seal. Even in this case, the sheet-like member lowers the toner density in the rubbing portion between the Teflon felt and the developing roller and in the vicinity thereof, and reliably prevents toner leakage.

In the above description, the developing device 5
The example in which the drum cartridge 2a in which 0 is mounted is configured to be attachable to and detachable from the image forming apparatus main body has been described, but the present invention is not limited to this. For example, only the developing device 50 portion forms an image. It may be detachable with respect to the apparatus main body, or a process cartridge (process cartridge according to claim 9) in which the drum cartridge 2a and the developing device 50 are integrally formed in a housing so as to be detachable with respect to the image forming apparatus. It may be configured. Further, the developing device 50 does not necessarily have to be attachable to and detachable from the image forming apparatus, and may be a stationary type. When the present invention is applied to the developing device cartridge and the process cartridge, it is possible to reliably prevent toner leakage at the time of attachment / detachment. It is possible to exert the effect of not being contaminated.

The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. Is easily guessed.

[0085]

According to the developing device of the first aspect of the present invention, both end portions are developed so as to rub against the peripheral surfaces of both ends of the developer carrying member in the vicinity of both ends in the longitudinal direction of the opening of the developing device housing. A developer leakage prevention member is provided, and the developer leakage prevention member at both ends is slidably rubbed against the developer carrier at the back surface position of the sliding surface of the developer leakage prevention member at the both ends. Since a sheet-like member that covers the boundary portion and the periphery of the rubbing boundary portion is provided, the sheet-shaped member is projected from the back position to the central portion side in the longitudinal direction of the developing device housing opening.
The developer density in the rubbing boundary portion and its periphery is reduced to prevent the developer from entering the rubbing portion between the developer leakage prevention member and the developer carrier at both ends, and the developer from the rubbing portion. Leakage can be reliably prevented. Also, as a result,
Since it is possible to suppress the pressing force of the developer leakage prevention member at both ends against the developer carrying member, it is possible to reduce the load on the motor.

According to the developing device of the second aspect, the both ends of the developer leakage prevention member are mounted on the base of the developing device, and the developer carrying member is mounted on the base. Since the sheet-like member is sandwiched between the base material portion and the rubbing portion,
To reduce the developer density at the sliding contact portion of the sliding contact portion and its periphery, prevent the developer from entering between the sliding contact portion and the developer carrier, and reliably prevent the developer from leaking. You can

According to the third aspect of the present invention, the developer made of a foamed elastic material is rotatably arranged while sliding on the developer carrying member and conveys the developer to the developer carrying member. Further, since the sheet feeding member is further provided and the projecting portion of the sheet-shaped member is sandwiched between the developer carrying body and the developer carrying supply body, a developer carrying body and a developer leakage preventing member at both ends are provided. To reduce the developer density in the sliding friction boundary portion and its periphery to prevent the developer from entering the sliding friction portion between the developer leakage prevention member and the developer carrying member at both ends, It is possible to reliably prevent developer leakage.

According to the developing device of the fourth aspect, since the sheet-like member is made of resin, it has an appropriate hardness and can reliably prevent the invasion of the developer, and is appropriately deformed. Therefore, the developer carrier can be easily attached in a shape along the peripheral surface.

According to the developing device of the fifth aspect, since the sheet-shaped member is formed of PET, it has an appropriate hardness and can reliably prevent the invasion of the developer, and is appropriately deformed. Therefore, the developer carrying member can be easily attached in a shape along the peripheral surface.

According to the developing device of the sixth aspect, since the notch is provided in the sheet-like member along the longitudinal direction of the developer carrying member, even when a load accompanying the rotation of the developer carrying member is received. Therefore, it is possible to reliably prevent the sheet-shaped member itself from breaking.

According to the developing device of the seventh aspect, the sheet-like portion is formed in the longitudinal direction of the opening of the developing device casing rather than the sliding frictional boundary between the developer leakage preventing member at both ends and the developer carrying member. Since the length of the protruding portion along the longitudinal direction is set to 1 mm or more by projecting to the center side, the developer exceeding the projecting portion can be reduced and the developer leakage can be prevented.
Moreover, the length of the protruding portion along the longitudinal direction is 4
Since it is less than or equal to mm, near the tip of the protruding portion,
It is possible to prevent toner deterioration without deteriorating the convection of the developer.

According to the developing device of the eighth aspect, since the polymerized toner produced by the polymerization method is used as the developer, the fluidity is high and the developer easily leaks. The toner density can be reliably prevented because the developer density at the boundary between the sliding portions between the developer leakage prevention member and the developer carrying member and the periphery thereof is reduced by the member.

According to the process cartridge of the ninth aspect, the process cartridge detachably attached to the image forming apparatus is provided with the developing device of any one of the first to eighth aspects. Even when the cartridge is attached or detached, the developer leakage can be surely prevented. Therefore, it is possible to provide an easy-to-use process cartridge.

According to the developing device cartridge of the tenth aspect, the developing device according to any one of the first to eighth aspects is detachably formed with respect to the image forming apparatus or the process cartridge. It is possible to reliably prevent the developer from leaking even when attaching or detaching. Therefore, it is possible to provide a developing device cartridge which is easy to use.

According to the image forming apparatus of claim 11,
Since the developing device according to any one of claims 1 to 8 or the process cartridge according to claim 9 or the developing device cartridge according to claim 10 is provided, developer leakage does not occur and the inside of the image forming apparatus main body is prevented. The developer contamination can be reliably prevented. Therefore, it is possible to form a high-quality image without print stains.

[Brief description of drawings]

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

2A is a partially cutaway perspective view showing a seal portion of the developing device case before the seal member is attached, and FIG. 2B is the seal seen from a direction of an arrow B shown in FIG. 2A. It is a figure which shows a part.

3A is a partially cutaway perspective view showing a seal portion of a developing device case when a side edge seal is attached, and FIG. 3B is a sectional view taken along line CC of FIG. 3A. , Fig. 3
(C), It is a figure which shows the said seal | sticker part seen from the arrow B direction shown in FIG. 3 (A).

4A is a partially cutaway perspective view showing a seal portion of a developing device case when an upper side seal mounting film is attached, and FIG. 4B is an arrow A shown in FIG. The figure which shows the seal part seen from the direction, and FIG.
It is a figure which shows the said sealing part 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.
5B is a diagram showing the seal portion viewed from the direction of arrow B shown in FIG.

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

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

FIG. 8A is a partially cutaway perspective view showing a seal portion of a developing device case when an upper side seal is attached,
8B is a diagram showing the seal portion viewed from the arrow A direction shown in FIG. 8A, and FIG. 8C is a diagram showing the seal portion viewed from the arrow B direction shown in FIG. 8A. Is.

FIG. 9 is a front view showing a seal portion of a developing device case when an upper seal is attached.

10 is a diagram showing a seal portion viewed from a direction of an arrow B shown in FIG.

11A is a partially cutaway perspective view showing a seal portion of a developing device case when an intermediate layer film is attached, and FIG. 11B is seen from a direction of an arrow B shown in FIG. 11A. It is a figure which shows the said seal part.

FIG. 12 is a partially cutaway perspective view showing a seal portion of a developing device case when a side edge seal is attached.

13A is a view of the layer thickness regulating blade viewed from the back side, FIG. 13B is a view of the layer thickness regulating blade viewed from the front side, and FIG. 13C is FIG. 11B. Similarly, it is a figure which shows the sealing part seen from the arrow B direction.

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

FIG. 15 (A) is a plan view showing the lower film and the periphery of its mounting portion, and FIG. 15 (B) is a view showing the adhesive surface of the lower film.

16 (A) is a partially cutaway perspective view showing a seal portion of the case 51 on the side opposite to FIG. 14 (A) when a lower film is attached, and FIG. 16 (B) is FIG. 14 (C). FIG. 7B is a view showing a seal portion viewed from the direction of arrow B as shown in FIG.

[Explanation of symbols]

1 Laser beam printer 50 developing device 51 cases 52 Toner Storage Room 59 developing roller 64 layer thickness control blade 64a pressure contact member 64b sheet metal 100 Side seal mounting area 101 Lower seal mounting area 102 Side edge seal 103 Upper Side Seal Attachment Film 104 side seal 105 Lower side seal 106 edge seal 107 Upper side seal 108 Upper seal 109 Intermediate film 109a notch 110 side edge seal 111 Back side blade side seal 112 Front blade side seal / 113 Teflon felt 114 lower film

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03G 15/08

Claims (11)

(57) [Claims] 1. A developer carrier is rotatably disposed in an opening of a developer housing for containing a developer, and a thin layer of the developer formed on the developer carrier is used as an electrostatic latent image. A developing device that forms a visible image by facing each other, and is provided in the vicinity of both longitudinal ends of the developing device housing opening so as to rub against the peripheral surfaces of both ends of the developer carrier. Both ends of the developer leakage prevention member and the both ends of the developer leakage prevention member are provided on the back surface of the sliding surface of the developer leakage prevention member, and the both ends of the developer leakage prevention member and the developer carrier. And a sheet-shaped member that covers the periphery of the sliding-rubbing boundary portion, and the sheet-shaped member projects from the rear position to the central portion side in the longitudinal direction of the developing device housing opening. Provided is a developing device. 2. The developer leakage prevention member at both ends is composed of a base member attached to the developing device casing, and a rubbing member attached on the base member to slide on the developer carrying member. 2. The developing device according to claim 1, wherein the sheet-shaped member is sandwiched between the base material portion and the rubbing portion. 3. A developer carrying / supplying member made of a foamed elastic body, which is rotatably arranged while rubbing against the developer carrying member, and which carries the developer to the developer carrying member, further comprising: 3. The developing device according to claim 1, wherein the projecting portion of the strip-shaped member is sandwiched between the developer carrying member and the developer carrying / supplying member. 4. The developing device according to claim 1, wherein the sheet-shaped member is made of resin. 5. The developing device according to claim 4, wherein the sheet-shaped member is made of PET. 6. The developing device according to claim 1, wherein the sheet-shaped member is provided with a cut along the longitudinal direction of the developer carrying member. 7. The sheet-like member protrudes toward the central portion in the longitudinal direction of the developing device housing opening from a sliding frictional boundary between the developer leakage preventing member at both ends and the developer carrying member. The length of the part along the longitudinal direction is 1 mm or more and 4 mm
The developing device according to any one of claims 1 to 6, wherein: 8. The developing device according to claim 1, wherein the developer is a polymerized toner produced by a polymerization method. 9. A process cartridge detachably formed on an image forming apparatus, comprising: the electrostatic latent image carrier; and the developing device according to claim 1. Process cartridge characterized in that. 10. A developing device cartridge, wherein the developing device according to claim 1 is detachably attached to an image forming apparatus or a process cartridge. 11. An image forming apparatus comprising the developing device according to claim 1, the process cartridge according to claim 9, or the developing device cartridge according to claim 10.