JP5742232B2 - Developing device, process cartridge, and image forming apparatus - Google Patents

Description

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

In an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a complex machine of these, it is widely performed that a developer is enclosed in a developing device in advance at the time of shipment from a factory and then incorporated into the image forming device. In such a developing device, generally, a sealing member (seal member) is arranged so that the developer does not leak from a gap between a developing housing that contains the developer and a developing roller attached thereto. For this reason, in order to use the image forming apparatus, it is necessary to perform an operation of removing the seal member disposed in the developing device.
For example, Patent Document 1 discloses a configuration in which a user pulls and peels off an end portion of a strip seal (seal member) that closes an opening on a lower surface of a case in which a developer is previously sealed, and drops the developer onto a conveyance member. Yes. Patent Document 2 discloses a configuration for automatically winding a seal. Patent Document 3 discloses a stirring assisting member for assisting the developer stirring.

However, in the developing device disclosed in Patent Document 1, when the user forgets to pull out the seal member and is driven in a state where it is set in the main body of the image forming apparatus, the developing device is operated without any developer and an abnormality such as a density sensor is caused. There was a risk of causing it.
Further, the developing device of Patent Document 2 requires a winding mechanism for the seal member, which increases the number of parts. The increase in the number of parts is not preferable from the viewpoint of low cost and low environmental load. Further, the developing device of Patent Document 3 requires the addition of an agitation assisting member, so that there is a problem that the number of parts is also increased.
SUMMARY An advantage of some aspects of the invention is that it provides a developing device, a process cartridge, and an image forming apparatus that can reliably remove a seal member.

The present invention has been made to solve the above-described problems, and can be realized by the following modes.
That is, in the first embodiment, the developing roller that carries the developer, the first housing that supports the developing roller, the second housing in which the developer is disposed, and the developer in the second housing are transferred to the first housing. A rotary first developer conveying member that conveys along the axial direction of the two housings and that conveys the developer to the developing roller, and the first developer conveying member is in the axial direction of the first developer conveying member receiving the developer conveyed one end to the vicinity of, that conveys the developer received the to the other end side near the first developer conveying member, developer circulation path together with the first developer conveying member Between the developing roller and the first developer conveying member, the second developer conveying member formed in the second housing, and a non-adhered state between the first housing and the second housing . Sea to cut off between And member, wherein the sealing member is formed integrally or connected, the sealing member is transported the second developer when they are removed from a position for blocking between the developing roller and the first developer conveying member And a stirring auxiliary member for stirring the developer in the vicinity of the member.
According to the first embodiment, since the sealing member for blocking between the developing roller and the first developer conveying member is disposed in a non-adhesive state between the first housing and the second housing, the sealing member It can be reliably removed with low torque.

The second aspect is characterized by a developing device in which at least a part of the periphery of the seal member is formed of a member having rigidity.
According to the second embodiment, it is possible to reliably enclose the developer by forming the periphery of the seal member with a member having rigidity.
According to a third aspect, the removal mechanism that removes the seal member from the position where the gap between the developing roller and the first developer transport member is blocked is the first developer that works in conjunction with the second developer transport member. The developing device has the same rotation axis as the rotation axis of the transport member.
According to the third aspect, since the removal mechanism can be configured with the same rotation axis as the rotation axis of the first developer conveyance member that is linked to the second developer conveyance member, the number of parts of the developing device can be reduced , and more Miniaturization is possible .

A fourth embodiment is a process cartridge that is detachable from the image forming apparatus, and the developing device according to any one of the first to third embodiments and a rotatable photosensitive member are integrated. Characterized by a process cartridge.
According to the 4th form, the process cartridge which has an effect as the image development apparatus of the said 1st-3rd form is realizable.
The fifth aspect is characterized by an image forming apparatus including the developing device according to any one of the first to third aspects or the process cartridge according to the fourth aspect.
According to the fifth aspect, it is possible to realize an image forming apparatus having effects as the developing devices of the first to third embodiments or the process cartridge of the fourth embodiment.

According to the present invention, since the seal member for blocking between the developing roller and the first developer conveying member is disposed between the first housing and the second housing in a non-adhered state , the seal member is reduced in torque. Can be removed reliably .

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an exemplary embodiment. It is sectional drawing which shows the structure of the image forming apparatus which concerns on this Embodiment. It is sectional drawing which shows distribution of the magnetic force in the image forming apparatus shown in FIG. FIG. 2 is an exploded perspective view showing a configuration of a developing device according to the present embodiment. (A) (b) is sectional drawing which showed the structure of the sealing member with which the image development apparatus of this embodiment is equipped. It is a schematic diagram of the removal operation of the seal member in the developing device of the present embodiment, (a) is a diagram showing the movement of the perforated part meshing with the sprocket gear, (b) shows the movement of the seal member and the stirring auxiliary member. FIG.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention.
In this image forming apparatus 100, image forming apparatuses 10Y (yellow), 10C (cyan), 10M (magenta), and 10K (black) for four colors as process cartridges are formed on the apparatus main body 1 side. The image forming station is detachable and includes an optical unit 20, an intermediate transfer body unit 30, a paper feeding unit 40, a fixing unit 50, and the like as exposure means capable of irradiating laser light.
The image forming apparatuses 10Y, 10C, 10M, and 10K have the same structure, and the photosensitive drums 12Y, 12C, 12M, and 12K as latent image carriers are charged, and the photosensitive drums are charged as process means that act on the photosensitive drums. The charging devices 13Y, 13C, 13M, and 13K and cleaning devices 15Y, 15C, 15M, and 15K for removing the developer remaining on the photosensitive drum are integrally configured, and formed on each photosensitive drum. The developing devices 14Y, 14C, 14M, and 14K for developing the latent images are connected.

The intermediate transfer body unit 30 includes a transfer belt 31 as an intermediate transfer body, a plurality of (here, three) rollers 32, 33, and 34 that rotatably support the transfer belt 31, and toner formed on each photosensitive drum 12. A primary transfer roller 35 for transferring the image to the transfer belt 31 and a secondary transfer roller 36 for transferring the toner image transferred onto the transfer belt 31 to the recording paper P are provided.
The paper feed unit 40 includes a paper feed roller 43 and a registration roller 44 that convey the recording paper P from the paper feed cassette 41 or the manual paper feed tray 42 to the secondary transfer region. The fixing unit 50 includes a fixing roller 51 and a pressure roller 52, and has a known configuration in which fixing is performed by applying heat and pressure to the toner image on the recording paper P.

  In such a configuration, first, in the first color yellow image forming device 10Y, the photosensitive drum 12Y is uniformly charged by the charging device 13Y, and then the latent image is developed by the laser light emitted from the optical unit 20. 14 is developed to form a toner image. The toner image formed on the photosensitive drum 12 is transferred onto the transfer belt 31 by the action of the primary transfer roller 35. The photosensitive drum 12Y after the primary transfer is cleaned by the cleaning device 15Y to prepare for the next image formation. The residual toner collected by the cleaning device 15Y is stored in a waste toner collection bottle 16 installed in the take-out direction of the image forming device 10Y (the rotation axis direction of the photosensitive drum). The waste toner collection bottle 16 is detachable from the image forming apparatus main body 1 so that it can be replaced when the storage amount is full. A similar image forming process is performed in each of the image forming apparatuses 10C, 10M, and 10K for C, M, and K to form toner images of the respective colors, which are sequentially transferred to the previously formed toner images.

On the other hand, the toner image formed on the transfer belt 31 by the action of the secondary transfer roller 36 is transferred to the recording paper P conveyed from the paper feed cassette 41 or the manual paper feed tray 42 to the secondary transfer region. . The recording paper P to which the toner image has been transferred is conveyed to the fixing unit 50, where the toner image is fixed at the nip portion between the fixing roller 51 and the pressure roller 52 of the fixing unit 50, and the discharge roller 55 discharges the upper part of the apparatus. The paper is discharged to the paper tray 56.
At the upper part of the apparatus main body 1 of the image forming apparatus 100, toner bolts Y1, C1, M1, and K1 each storing toner to be supplied to a toner replenishing port 145, which will be described later, are detachable from the apparatus main body 1 separately from each image forming apparatus. It is attached to.

Next, the configuration of the image forming device and the developing device will be described. Each apparatus configuration is the same except that the color of the supplied toner as the developer is different, and therefore the image forming apparatus 10Y will be described below as an example.
FIG. 2 is a cross-sectional view showing the configuration of the image forming apparatus, and FIG. 3 is a cross-sectional view showing the distribution of magnetic force in the image forming apparatus shown in FIG. The charging device 13Y provided in the image forming device 10Y includes a charging roller 131 and a cleaning roller 132 that cleans the surface of the charging roller 131. The cleaning device 15Y includes a cleaning brush 151 and a cleaning blade 152 that are in contact with the surface of the photosensitive drum, and a toner recovery coil 153 that transports the toner scraped off by the cleaning brush 151 and the cleaning blade 152 toward the waste toner recovery bottle 16. It has.

The developing device 14Y carries the toner of the two-component developer and conveys it by rotating it counterclockwise in FIG. 2 to a developing region facing the photosensitive drum 12Y, and the developing device 141 is disposed facing the developing roller 141. The doctor blade 146 that forms a doctor gap S as a developer restricting portion for restricting the layer thickness of the toner carried on the surface of the developing roller 141 between the surface of the developing roller 141 and the developing device 14Y is housed. The second conveying screw, which is a second developer conveying member that guides the developing roller 141 while agitating the developer being supplied and the replenishing toner supplied from the toner replenishing port 145 while reciprocally conveying in the axial direction of the photosensitive drum 12Y. 142 and a first conveying screw 143 that is a first developer conveying member, and a developing casing 144 that accommodates and supports these members. Eteiru. The doctor blade 146 is supported so as to be sandwiched between the developing casings 144. In this example, the developing casing 144 is divided into a first housing 144A that holds the developing roller 141 and a second housing 144B that holds the conveying screws 142 and 143. In FIG. 3, the division | segmentation location of 144 A of 1st housings and the 2nd housing 144B was shown by the AA line.
The first housing 144A supports or configures the developing roller 141, the doctor blade 146, and the toner supply port 145. Further, the first housing 144A and the second housing 144B are fixed so as to sandwich the adhesive margin portion of the seal member 160 between the two housings in a light pressure contact state in which the seal member 160 described later is pulled out. In this example, in this state, a guide action is performed when the seal member 160 is pulled out and peeled off.

Here, the first transport screw 143 receives the developer transported to the vicinity of one end side in the axial direction by the second transport screw 142, and transports it to the vicinity of the other end portion side of the first transport screw 143. A developer circulation conveyance path is formed in the second housing 144B by one housing 144A.
A plurality of magnets (not shown) are disposed inside the developing roller 141. The distribution of the magnetic force in the normal direction by these magnets is indicated by symbols P1 to P5 in FIG. In the present embodiment, there is P5 as an opposite pole of the doctor blade 146, and P1: 105 mT, P2: 95 mT, P3: 45 mT, P4: 45 mT, and P5: 84 mT.
A receiving member 147 supported by the developing casing 144 is provided upstream of the doctor blade 146 in the moving direction of the developing roller 141. The developing roller 141, the doctor blade 146, and the receiving member 147 are extended in the axial direction of the photosensitive drum. The receiving member 147 has a substantially right triangle shape, and protrudes from the casing toward the space 148 where the toner is pumped up and retained by the first conveying screw 143 inside the developing casing 144. Specifically, the top of the right triangle protrudes so as to be located toward the surface of the developing roller 141 and is adjacent to the doctor blade 146. The receiving member 147 is provided with a toner receiving surface 147 a that moves from the space portion 148 toward the doctor blade 146. The top of the receiving member 147 is substantially the same as or somewhat lower than the tip of the doctor blade 146.

According to the developing device 14Y having such a configuration, the receiving member 147 is provided around the layer thickness regulating portion of the doctor blade 146 in the space portion 148 where the toner stays and flows toward the doctor blade 146. Other than that, it is concealed by the receiving member 147. As a result, the toner pressure applied to the doctor gap S is reduced, and the displacement of the doctor gap S is suppressed, so that the variation in the toner supplied to the photosensitive drum 12Y is extremely reduced.
Although the receiving member 147 is provided on the back side of the doctor blade 146, if a gap is formed between the back side of the doctor blade 146 and the receiving member 147, toner may accumulate between the two, and the doctor gap S can be narrowed. For this reason, a gap S1 is provided in advance between the back side of the doctor blade 146 and the receiving member 147, and a plate-like elastic member 150 serving as a seal member is inserted into the gap S1, thereby interposing this. It is possible to prevent toner accumulation and agent dropping with respect to the gap.
Further, in the present embodiment, each toner bottle is detachably attached to each image forming apparatus from the apparatus main body 1, so that each toner bottle and each image forming apparatus can be exchanged individually, which is unnecessary. Therefore, the user's expense at the time of parts replacement can be reduced. Further, since the number of times of opening / closing and taking in / out of other parts of the apparatus is reduced, it is possible to prevent toner scattering and improve maintainability.

  A toner having a sphericity of 0.93 or more can also be used as the toner used in this embodiment. In other words, it is known to reduce the toner particle size in order to improve the image quality of the image, but in the case of reducing the particle size, the conventional pulverized toner has a particle size distribution that is broad. There is a characteristic that it is difficult. Therefore, it is possible to achieve high image quality by increasing the circularity of the toner by a polymerization method or the like and by making the particle size distribution sharp. However, when the circularity of the toner is increased, the toner approaches a spherical shape, so that cleaning with the cleaning device 15Y becomes very difficult. However, in this embodiment, since the receiving member 147 is provided, the photosensitive due to the displacement of the doctor gap S is provided. Since there is no variation in the amount of toner supplied to the body drum 12Y, the cleaning performance can be maintained even when spherical toner obtained by polymerization or the like is used.

FIG. 4 is an exploded perspective view showing a schematic configuration of the developing device according to the present embodiment.
A developing roller 141 (not shown) is held in the first housing 144A, which is the upper case, and a driving force is transmitted from the developing driving gear 67 to the developing roller driving gear 63 so that the developing roller 141 is It has a rotatable structure. A first conveying screw 143 and a second conveying screw 142 are held in the second housing 144B, which is the lower case, so that the developer can be stirred.
The first conveying screw 143 and the second conveying screw 142 rotate by obtaining driving force from the first screw driving gear 61 and the second screw driving gear 62, respectively. The first screw drive gear 61 and the second screw drive gear 62 are connected by an idler gear 64.

The first housing 144A has a toner replenishing port 145 that can replenish toner from a replenishing mechanism (not shown).
A developer seal member (hereinafter referred to as “seal member”) 160 is sandwiched between the first housing 144A and the second housing 144B in a non-adhered state that is not bonded to the second housing 144B by gluing or the like. , The conveyance path of the first conveyance screw 143 and the developing roller 141 held by the first housing 144A are blocked. A stirring assist member 163 is attached to the seal member 160.
Further, at both ends in the short direction of the seal member 16, perforated portions 161 and 162 having perforations for engaging and removing sprocket gears 65 and 66 described later to move the seal member 160 in the direction of the second conveying screw. Is provided.

FIG. 5 is a cross-sectional view illustrating a configuration of a seal member provided in the developing device of the present embodiment.
The seal member 160 shown in FIG. 5A is configured by affixing, for example, a 0.2 to 0.3 mm film-like stirring auxiliary member 163 made of polyethylene terephthalate to a seal portion 160a made of polycarbonate, for example.
In addition, the seal member 160 shown in FIG. 5B is configured such that, for example, a 0.2 to 0.3 mm film made of polyethylene terephthalate is bent to form the seal portion 160a and the stirring assisting member 163.
In the developing device configured to wind up the seal member, for example, an ultra-thin (20 to 40 μm) polyethylene terephthalate film is used for winding, and the first housing 144A and the first housing 144A are not glued. When used as the seal member 160 in a configuration in which the second housing 144B is sandwiched with a pressure that allows it to be pulled out lightly, the seal member 160 has almost no rigidity, so that there is an increased risk of the seal being deformed and causing agent leakage from the end.

On the other hand, in the developing device of the present embodiment, the seal member 160 is made of a hard material such as 0.2 to 0.3 mm thick film or polycarbonate, so that the first housing 144A and the second housing 144B are separated. Even if it is configured to be lightly sandwiched between them, there is no risk of agent leakage due to deformation of the seal member 160. That is, even when the seal member 160 is disposed in a non-adhered state where it is not adhered to the second housing 144B by gluing or the like, there is no risk of agent leakage due to deformation of the seal member 160.
Further, since the seal member 160 is only lightly sandwiched, there is an advantage that the driving force at the time of removing the seal can be reduced.
In the present embodiment, the case where a hard material is used for the entire seal member 160 has been described as an example, but at least the periphery of the seal member 160 in contact with the first housing 144A and the second housing 144B is rigid (rigid) If it is made of a material, it is possible to prevent the agent leakage due to the deformation of the seal member 160.
In the developing device of this embodiment, sprocket gears 65 and 66 that are the same as the drive shaft of the first conveying screw 143 are attached to both ends of the second housing 144B, and are provided at both ends of the seal member 160. The perforated portions 161 and 162 are engaged with the perforations. If the rotation shafts of the sprocket gears 65 and 66 are configured to be the same rotation shaft as the first conveying screw 143 as described above, it is not necessary to separately provide a winding shaft for winding the sheet member 160. There is an advantage that can be reduced.

Next, the removal operation of the seal member in the developing device of this embodiment will be described.
6A and 6B are schematic views of the removal operation of the seal member in the developing device of the present embodiment, in which FIG. 6A shows the movement of the perforated portion where the sprocket gear meshes, and FIG. 6B shows the seal member 160 and the stirring auxiliary member. It is the figure which showed the motion of 163. FIG.
First, at the time of setting, as shown in FIG. 6A, the perforated portion 161 of the seal member 160 is engaged with the sprocket gear 65 attached to the first conveying screw 143. At this time, FIG. As shown, the seal member 160 is attached so as to seal between the developing roller 141 and the first conveying screw 143.
Next, during the removal operation of the seal member, when the development drive gear 67 starts to move as shown in FIG. 6A, the drive is transmitted to the drive shaft of the first conveying screw 143, and the sprocket gear 65 also rotates simultaneously. As a result, the perforated portion 161 meshing with the sprocket gear 65 slides, and the seal member 160 moves from the drive shaft of the first transport screw 143 to the drive shaft of the second transport screw 142 as shown in FIG. Go to.
When the seal member 160 is sufficiently moved, the sprocket gear 65 and the perforated portion 161 are disengaged as shown in FIG. 6A, the movement of the seal member 160 is stopped, and the removal of the seal member is completed. . After the removal of the seal member is completed, the sprocket gear 65 and the perforated portion 161 of the seal member 160 are disengaged, so that when the developing device is driven, almost no force is applied to the seal member 160 and operation is performed with low torque. It becomes possible to make it.
Further, in this embodiment, the configuration is such that the stirring assisting member 163 attached to the sealing member 160 contacts the second conveying screw 142 after the completion of the removal of the sealing member. Accordingly, there is an advantage that an effect of assisting the mixing of the toner that slides upward on the developer and the developer can be obtained.

  65 66 ... sprocket gear, 67 ... development drive gear, 141 ... development roller, 142 ... second transport screw, 143 ... first transport screw, 144A ... first housing, 144B ... second housing, 160 ... seal member, 161 162 ... Punching part, 163 ... Agitation auxiliary member

JP 2001-075346 A JP 2000-235301 A JP 2006-106282 A

Claims (5)

A developing roller carrying a developer;
A first housing that supports the developing roller;
A second housing in which the developer is disposed;
A rotary first developer conveying member that conveys the developer in the second housing along the axial direction of the second housing and conveys the developer to the developing roller;
The first developer transport member receives the developer transported to the vicinity of one end side in the axial direction of the first developer transport member, and the received developer is received to the vicinity of the other end side of the first developer transport member. by conveying a second developer conveying member for forming a developer circulation path in said second housing with said first developer conveying member,
A seal member disposed in a non-adhered state between the first housing and the second housing and blocking between the developing roller and the first developer conveying member ;
The seal member is formed integrally with or connected to the seal member, and when the seal member is removed from a position where the seal between the developing roller and the first developer transport member is removed , the seal member is located near the second developer transport member. An agitation auxiliary member for agitating the developer;
A developing device comprising:   2. The developing device according to claim 1, wherein at least a part of the periphery of the seal member is formed of a member having rigidity. 3. The developing device according to claim 1, wherein a removing mechanism that removes the seal member from a position that blocks between the developing roller and the first developer conveying member is interlocked with the second developer conveying member. A developing device having the same rotation axis as the rotation axis of the first developer conveying member. A process cartridge that is detachable from the image forming apparatus,
4. A process cartridge , wherein the developing device according to claim 1 and a rotatable photosensitive member are integrated .   An image forming apparatus comprising the developing device according to claim 1 or the process cartridge according to claim 4.

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