JP2010044201A - Developer leakage preventing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive and stable developer leakage preventing device. <P>SOLUTION: The developer leakage preventing device includes: a cleaning rubber 1a, which is formed of elastic body and integrally provided with a pair of plate-like projections 1c extending in parallel in the longitudinal direction; and a projecting part 3a provided on a cleaning container 3 storing toner 8 in the interior thereof extending in the longitudinal direction. The projecting part 3a inserted between the pair of plate-like projections 1c is brought into close contact with the respective inside surfaces 1c<SB>1</SB>of the pair of plate-like projections 1c. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a developer leakage prevention apparatus for preventing leakage of a developer from a container that accommodates the developer, and an image forming apparatus including the developer leakage prevention apparatus.

  A fine powder toner is used as a developer of an electrophotographic apparatus. With the recent progress in print quality and color, the toner tends to become finer. In the process cartridge, the toner accommodated in the developing container is fed from the developing container and is formed on the developing sleeve by the developing blade so that the thickness of the developer layer is constant, and the electrostatic latent image is formed on the photosensitive drum. Are sequentially transferred to the printing paper and further transferred onto the printing paper. A part of the toner remaining on the photosensitive drum is removed by the cleaning blade and stored in the cleaning container.

  Here, in the electrophotographic apparatus, it is necessary to prevent the toner from leaking from the process cartridge during printing, standby, and while the process cartridge is being detached from the main body of the electrophotographic apparatus. Therefore, various leak-proof members are used in the process cartridge depending on the application.

  In particular, since the toner in the developing container and the cleaning container contains a large amount of toner, a toner leakage preventing member that can surely prevent leakage is required. Further, since the process cartridge is a consumable item, an inexpensive toner leakage prevention member is required.

  As a conventional method for preventing toner leakage from a process cartridge, there is a method in which a liquid elastomer is poured into a cartridge frame and the elastomer is solidified to form a seal (Patent Document 1).

Further, as shown in FIG. 5, the elastic protrusion C is generated by the amount corresponding to the gap G between the blade support plate and the container, which is generated when the elastic protrusion P formed on the blade is in contact with the container. Some of them have crushed and formed a seal (Patent Document 2).
Japanese Patent Registration No. 2678077 JP 2003-107901 A

  The above-described seal formed by pouring and forming a liquid elastomer into the cartridge frame provides a reliable sealing property. However, it takes 3 to 10 minutes to cure after pouring the elastomer, and in order to prevent the poured liquid elastomer from flowing out, it is necessary to maintain the outflow prevention posture during the curing time with the cartridge support jig. For this reason, mass production of process cartridges requires many cartridge support jigs for ensuring the curing time of the elastomer, making it difficult to produce seals at low cost.

  On the other hand, a seal that forms a rubber elastic body convex portion on the blade and makes contact with the container forms a seal member on the blade, and it is not necessary to form a seal portion of the elastic body on the cartridge, and the cost can be reduced. However, due to the recent increase in printing speed and image quality in electrophotographic apparatuses, and the finer particles of toner that accompany color, rubber elastic bodies used in blades tend to have higher hardness.

  In the method of crushing the rubber elastic body convex portion by pressing the rubber elastic body convex portion with high hardness against the container, a large load is generated in the direction of crushing the rubber elastic body on the blade support plate and the container. As a result of this load deforming the blade or the container, the positional relationship between the blade and the blade abutting member may change, resulting in a printing failure due to an image forming process such as a cleaning failure or a development failure.

  In view of the above problems, an object of the present invention is to provide a low-cost and stable developer leakage preventing member.

  In order to achieve the above object, a developer leakage prevention apparatus according to the present invention is a blade member made of an elastic body, and includes a pair of plate-like protrusions extending in parallel with the longitudinal direction of the blade member. And a protrusion that extends in the longitudinal direction of the container, and the protrusion is inserted between the pair of plate-shaped protrusions, and the pair of plate-shaped It is in close contact with each inner surface of the protrusion.

  According to the present invention, it is possible to provide a low-cost and stable developer leakage prevention apparatus without adding a member.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view of a process cartridge in the image forming apparatus of the present embodiment.

  In FIG. 1, the developer leakage preventing member indicated by X prevents the toner 8 collected inside the cleaning container 3 from leaking from the gap with the cleaning blade 1 attached to the cleaning container 3. In FIG. 1, the developer leakage preventing member indicated by the Y portion is similarly developed with toner 8 of fine particle powder, which is a developer housed in the developer container 4, attached to the developer container 4. Leakage from the gap with the blade 2 is prevented.

  First, an outline of the configuration of the image forming apparatus of the present embodiment will be described.

  As shown in FIG. 1, the image forming apparatus has a photosensitive drum 6 as an image carrier. The surface of the photosensitive drum 6 is uniformly charged by the charging device 5, and image exposure corresponding to an image signal (for example, an input original image) is irradiated to the charged surface of the photosensitive drum 6 by an exposure device (not shown). Is done. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 6.

  This electrostatic latent image is developed by a developer container 4 containing toner 8, a developing sleeve 7 and a developing device 10 having a developing blade 2 to form a toner image. The toner 8 is carried out of the developer container 4 with a developing sleeve 7 serving as a developer carrying member carried on the surface thereof. At that time, the conveyance amount of the toner 8 is regulated by the developing blade 2 which is a developer amount regulating blade.

  Thereafter, the toner image on the photosensitive drum 6 is transferred by a transfer device (not shown) to the recording medium fed in time with the toner image.

  After the transfer, the residual toner remaining on the photosensitive drum 6 is removed by the cleaning blade 1 of the cleaning device 11 and collected in the cleaning container 3.

  The recording medium (not shown) onto which the toner image has been transferred is sent to a fixing device (not shown) via a guide or the like, and after the toner image is fixed by the fixing device, it is discharged out of the image forming apparatus.

  Next, the developer leakage preventing member of this embodiment will be described in detail with reference to FIGS.

  2 is an enlarged view of the developer leakage preventing member of the present embodiment, FIG. 2 (a) is an enlarged view of an X portion in FIG. 1, and FIG. 2 (b) is an enlarged view of a Y portion in FIG. It is an enlarged view. FIG. 3 is a side sectional view of the cleaning blade and the developing blade. FIG. 4 is an enlarged view for explaining the engagement relationship in the developer leakage preventing member. 4A and 4B show the developer leakage prevention member shown in FIG. 2 as an example, but FIGS. 4C and 4D show the developer leakage prevention member. Another modification is shown.

  As shown in FIG. 2A, the developer leakage preventing member in the X part includes a cleaning rubber 1 a that is a blade member and a protrusion 3 a formed on the cleaning container 3. The developer leakage preventing member at the Y portion shown in FIG. 2B has the developing blade 2 and the protrusion 4a formed on the developer container 4. The basic configuration is shown in FIG. This is the same as the developer leakage preventing member for the portion X shown in (a). Therefore, here, the configuration and the function and effect of the developer leakage preventing member in the X part having the cleaning blade 1 and the cleaning container 3 will be described.

The cleaning blade 1 includes a cleaning rubber 1a that is a blade member, and a cleaning support plate 1b that is a support member that supports the cleaning rubber 1a. The cleaning rubber 1a is made of an elastic body such as rubber, and has a recess 1a1 on _one end side. The cleaning rubber 1a is supported by the cleaning support plate 1b with the cleaning support plate 1b is inserted into the recess 1a _1.

A on the main surface of the cleaning rubber 1a, a position corresponding to the concave portion 1a ₁ pair of plate-like projections 1c extending longitudinally with collateral (the direction perpendicular to the paper surface) is provided. As will be described later, the protrusion 3a of the cleaning container 3 is inserted into the pair of plate-like protrusions 1c. In this embodiment, the plate-like protrusion 1c is inserted into the recess 1a ₁ into which the cleaning support plate 1b is inserted. It is provided at the corresponding position. For this reason, the cleaning support plate 1b receives the force in the advancing direction when inserting the protrusion 3a, and the cleaning rubber 1a does not escape when the protrusion 3a is inserted.

Incidentally, the developing rubber 2a of the developing blade 2 is not formed with the concave portion 1a _{1 which} is formed in the cleaning rubber 1a. However, as shown in FIG. 3B, in the developing rubber 2a, the plate-like protrusion 2c is located on the main surface 2b ₁ of the developing support plate 2b, so that the protruding portion 4a of the developer container 4 is inserted. At this time, the developing rubber 2a does not escape.

In the cleaning container 3, an opening 3 b for collecting the residual toner from the photosensitive drum 6 in the cleaning container 3 is formed. The cleaning support plate 1b of the cleaning blade 1 is fixed to the wall surface of the cleaning container 3 so that the cleaning rubber 1a is disposed on the opening surface of the opening 3b. At the position where the plate-like protrusion 1c of the cleaning rubber 1a is disposed, which is the peripheral portion of the opening 3b, the protrusion 3a protrudes in a direction toward the pair of plate-like protrusions 1c. Protrusion 3a shown in FIG. 4 (a) is a side 3a ₁ is chamfered. Therefore, the cross-sectional shape of the protrusion 3a is a tapered shape in which the width of the tip 3a ₂ is shorter than the root 3a ₃ of the protrusion 3a.

The distance d between the plate-like projection 1c is wider than the width of the tip portion 3a ₂ of the protruding portion 3a, and narrower than the width of the root portion 3a _3.

  Next, the relationship between the protrusion 3a and the pair of plate-like protrusions 1c when the cleaning blade 1 is attached to the cleaning container 3 will be described with reference to FIGS. 4 (a) and 4 (b).

  4A shows a state before the cleaning blade 1 is attached to the cleaning container 3, and FIG. 4B shows a state where the cleaning blade 1 is attached.

By moving the cleaning container 3 in the direction of arrow A shown in FIG. 4A, the tip 3a ₂ of the protrusion 3a is inserted between the pair of plate-like protrusions 1c, resulting in the state of FIG. 4B. .

When the protrusion 3a is inserted, the tapered side surface 3a ₁ presses the inner surface 1c ₁ of the plate-like protrusion 1c. Here, the plate-like protrusion 1c is curved outward from its root portion, the contact portion with the protrusion 3a is slightly crushed and deformed, and the side face 3a ₁ of the protrusion 3a and the inner face 1c ₁ of the plate-like protrusion 1c are mutually connected. It will be in close contact. Further, the tip 3a ₂ of the protrusion 3a is in a positional relationship floating from the bottom surface of the plate-like protrusion 1c. That is, when the cleaning blade 1 is attached to the cleaning container 3, a leakage preventing effect is exerted by the bending moment-like pressing force by the plate-like protrusion 1 c. Moreover, since the plate-like protrusions 1c are opposed to each other with the protrusion 3a as the center, the force for shifting the cleaning blade 1 in the mounting surface direction is canceled out. A force also acts in the direction of the mounting surface of the cleaning blade 1 and the cleaning container 3, but the deformation of the cleaning support plate 1b or the cleaning container 3 can be made slight by considering the point of action of the force. Further, as described above, since a method of applying a pressing force like a bending moment can be used, in the present invention, a material having a high rubber hardness can be used as the material of the cleaning rubber 1a.

As described above, the developer leakage preventing member of the present embodiment has a configuration in which the side surface 3a ₁ of the protrusion 3a presses the inner surface 1c ₁ of the plate-like protrusion 1c, and the contact portion is crushed and deformed to be in close contact with each other. It has become. With this configuration, the toner 8 in the cleaning container 3 is prevented from leaking from the attachment portion between the cleaning blade 1 and the cleaning container 3. In addition, since the developer leakage preventing member of the present embodiment has a pair of plate-like projections 1c, even if the toner 8 slips through one of the pair of plate-like projections 1c, the other plate-like projection 1c is used. It is possible to supplement and stable toner leakage prevention is possible.

As described above, according to the present embodiment, the side surface 3a ₁ of the protrusion 3a presses the inner surface 1c ₁ of the plate-like protrusion 1c, and the contact portion is crushed and deformed, thereby bringing them into close contact with each other. It is possible to reliably prevent toner leakage.

  Further, because of the above configuration, a rubber elastic body having high hardness can be applied to the plate-like protrusion 1c. That is, even in the case where a hard rubber elastic body is applied to the cleaning rubber 1a in order to cope with high-speed printing, high image quality, and finer toner particles associated with color in the electrophotographic apparatus, the cleaning rubber A plate-like protrusion 1c can be integrally provided on 1a. For this reason, according to this embodiment, the developer leakage preventing member can be manufactured at low cost.

Note that the Y portion developer leakage prevention member including the developing blade 2 and the protrusion 4 a of the developer container 4 also has the same effects as the cleaning blade 1 and the cleaning container 3. 4 (c) and 4 (d), the protrusion 3a has a chamfered corner 3c between the tip 3a ₂ and the side surface 3a ₁ of the protrusion 3a. This also has the same effect. Therefore, the detailed description about these is abbreviate | omitted.

  Hereinafter, the cleaning blade will be described as an example, but the present invention is not limited to the embodiment.

  In this example, the cleaning blade 1 shown in FIG. 3A was manufactured, and a test for toner leakage from the cleaning container 3 equipped with the cleaning blade 1 was performed.

  In the cross-sectional view of the cleaning blade 1, polyurethane rubber, which is integrally formed with a pair of plate-like protrusions 1c at one end of the cleaning rubber 1a, is integrated by attaching it to one end in the width direction of the cleaning support plate 1b.

  The cleaning blade 1 was molded using a mold (not shown) that can be divided in the rubber thickness direction. As a material for the cleaning blade 1, a mixture mainly containing an isocyanate group-terminated prepolymer was used. This main agent is obtained by reacting 0.097 mole part of polyethylene adipate-based polyester polyol: PAE with 1.0 mole part of 4,4'-diphenylmethane diisocyanate: MDI. The trade name of PAE is “Nipporan 4040”, manufactured by Nippon Polyurethane Industry Co., Ltd. To this, 1.0 mol part of PAE (trade name “Nipporan 4040” manufactured by Nippon Polyurethane Industry Co., Ltd.) and 2.0 mol parts of 1,4-BD as a chain extender and 1.1 mol parts of a crosslinking agent Trimethylolpropane (TMP) was mixed to obtain a mixture. Furthermore, the catalyst triethylenediamine (TEDA) was added to this mixture so that it might become 0.025 mass%, the hardening | curing agent was prepared, and it stirred and mixed with the casting machine (not shown).

  Cleaning support plate 1b preliminarily coated with a mold: galvanized steel plate is set, preheated to 120 ° C with a hot platen, the mixture is poured into the mold, cured and removed from the mold, and the polyurethane tip is removed It was obtained by cutting into a predetermined shape. As a galvanized steel sheet, a trade name “JINCOAT 21” manufactured by Nippon Steel Corporation was used.

  Here, the plate-like protrusion 1c formed a recess corresponding to the plate-like protrusion 1c in the dividing direction of the mold, and a draft angle of 3 ° was provided on both the inside and outside of the plate-like protrusion 1c. Thereby, the cleaning rubber 1a that contacts the photosensitive drum 6 and the plate-like protrusion 1c constituting the leak-proof can be simultaneously molded in a single molding process, and can be manufactured at a lower cost than a method that requires other processes. Became possible. The shape of the plate-like protrusion 1c was such that the plate thickness W at the protrusion root was 1.0 (mm), and the height H of the plate-like protrusion 1c was 1.8 (mm). In addition, equilateral gradients are provided on both side surfaces of the protrusion 3a formed on the cleaning container 3 so that the tip taper angle of the protrusion 3a is 60 °.

Next, as shown in FIG. 1, in the process cartridge, the center of the pair of plate-like protrusions 1c and the center of the protrusion 3a of the cleaning container 3 are matched, and the cleaning blade 1 is attached to the cleaning container 3 with screws. . Thereby, the plate-like protrusion 1c is expanded along the tapered side surface 3a ₁ of the protrusion 3a. In this state, the plate width in the first contact position on the chamfered portion of the side surface 3a ₁ of the protrusions 1c be of the tip projecting portion 3a, 0.4 to taper the width direction from the state before the mounting ( mm) has been expanded.

  While the toner 8 is collected in the cleaning container 3, printing in the electrophotographic apparatus and attachment / detachment of the process cartridge to / from the electrophotographic apparatus are performed. However, toner leakage from the toner leakage member constituted by the cleaning blade 1 and the cleaning container 3 is caused. Did not occur.

  In this example, the developing blade 2 shown in FIG. 3B was manufactured, and the toner leakage from the developer container 4 equipped with the developing blade 2 was tested.

  As with the cleaning blade 1, the developing blade 2 is formed by integrally forming polyurethane rubber in which a pair of plate-like protrusions 2c are integrally formed at one end of the developing rubber 2a at one end in the width direction of the developing support plate 2b. .

  The developing rubber 2a was molded by a so-called centrifugal molding method using a drum mold in which grooves corresponding to the plate-like protrusions 2c were formed in the circumferential direction of the inner circumferential surface of the cylindrical drum.

  First, a drum mold heated to a temperature of 120 ° C. is rotated in the axial direction, and the same liquid polyurethane rubber raw material as that of Example 1 is stirred and mixed by a casting machine, injected into the drum mold and cured, and a pair of outer circumferences A plate-like rubber protrusion was formed. Then, a rubber cylinder having a radial cross section including the shape of the developing rubber 2a shown in FIG. 3B was molded, and the rubber cylinder was opened and cut into a predetermined size to obtain a developing rubber 2a. Further, the developing rubber 2a was adhered to the developing support plate 2b: galvanized steel plate (trade name “JINCOAT 21” manufactured by Nippon Steel Corporation) via a polyester hot melt adhesive to obtain the developing blade 2. .

  The shape and positional relationship of the plate-like protrusion 2c formed on the developing blade 2 and the protrusion 4a formed on the developer container 4 were the same as those in Example 1, and were mounted on the process cartridge as shown in FIG. The toner from the toner leaking member constituted by the developing blade 2 and the developer container 4 was printed in the electrophotographic apparatus while the toner 8 was accommodated in the developer container 4 and the process cartridge was attached to and detached from the electrophotographic apparatus. There was no leakage.

FIG. 2 is a cross-sectional view of a process cartridge having a developer leakage prevention apparatus according to an embodiment of the present invention. FIG. 3 is a partially enlarged view of the developer leakage preventing apparatus according to an embodiment of the present invention. It is a sectional side view of a cleaning blade and a development blade in one embodiment of the present invention. FIG. 4 is an enlarged view for explaining an engagement relationship in a developer leakage preventing member according to an embodiment of the present invention. It is a figure which shows the seal structure disclosed by patent document 2. FIG.

Explanation of symbols

1a cleaning rubber 1c plate-like protrusion 1c ₁ inner surface 3 cleaning container 3a protrusion

Claims (6)

A blade member made of an elastic body, comprising a pair of plate-like protrusions extending in parallel with the longitudinal direction of the blade member; and
A container containing a developer, and a protrusion provided to extend in the longitudinal direction of the container;
The developer leakage prevention apparatus, wherein the protrusion is inserted between the pair of plate-like protrusions and is in close contact with each inner side surface of the pair of plate-like protrusions.   The developer leakage prevention apparatus according to claim 1, wherein the blade member is integrally provided with the pair of plate-like protrusions.   The developer leakage prevention apparatus according to claim 1, wherein a side surface of the projection portion presses each inner side surface of the pair of plate-like projections.   4. The developer leakage prevention apparatus according to claim 1, wherein the side surface is a chamfered surface of the protruding portion. 5. A developer carrier that carries the developer on the surface and carries it out of the developer container, and a developer amount that contacts the developer carrier and regulates the amount of developer carried on the surface of the developer carrier In an image forming apparatus having a regulation blade,
5. An image comprising the developer leakage prevention apparatus according to claim 1, wherein the developer container is the container, and the developer amount regulating blade has the blade member. Forming equipment. In an image forming apparatus comprising: a cleaning blade that removes the developer remaining on the photosensitive drum; and a cleaning container that collects and stores the developer removed by the cleaning blade.
An image forming apparatus comprising the developer leakage prevention apparatus according to claim 1, wherein the cleaning container is the container, and the cleaning blade has the blade member.

Images