CN105938311B

CN105938311B - Developing device, process cartridge and image forming apparatus

Info

Publication number: CN105938311B
Application number: CN201610101057.XA
Authority: CN
Inventors: 大吉浩文
Original assignee: Liguang Co
Current assignee: Liguang Co
Priority date: 2015-03-05
Filing date: 2016-02-24
Publication date: 2020-01-10
Anticipated expiration: 2036-02-24
Also published as: CN105938311A; JP2016167046A

Abstract

The invention provides a developing device, a process cartridge and an image forming apparatus capable of improving the performance of preventing or inhibiting developer on the surface of a developer carrier from scattering to the periphery of the developing device. The developing device (1) includes an end sealing member (6) abutting against outer peripheral surfaces of both end portions in a longitudinal direction (Y) of a rotating developer carrier (2), and an inlet sealing member (7) abutting against the end sealing member (6) at a center portion in the longitudinal direction (Y) while abutting against the developer carrier (2), the end portion in the longitudinal direction (Y) abutting against the end sealing member (6), the end sealing member (6) having a cutout portion (6A) in the center portion on an upstream side in a rotation direction of the developer carrier (2), the inlet sealing member (7) covering an edge portion in the longitudinal direction Y of the cutout portion (6A).

Description

Developing device, process cartridge and image forming apparatus

Technical Field

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

Background

An image forming apparatus employing an electrophotographic method is equipped with a developing device that performs visible image processing of an electrostatic latent image. The developing device has a structure such as a sealing member provided at both longitudinal ends of the developer carrier in order to prevent the developer in the developing device from being inadvertently scattered to the peripheral portion of the developer carrier (for example, patent document 1).

Since the leakage of the developer in the same direction is blocked by the pair of seal members provided in contact with the surface of the developer carrier at both ends in the longitudinal direction of the developer carrier, it is possible to prevent the developer from scattering to the outside at both ends in the same direction. Even in the center in the same direction, another sealing member is preferably provided along the same direction in order to prevent the developer in the developing device from leaking to the outside. In order to prevent the scattering of the developer, it is preferable to arrange the sealing members so that the ends in the same direction overlap each other. However, simply arranging the sealing members in an overlapping manner allows the developer carried by the surface of the developer carrier to be blocked at the overlapping portion, and the blocked developer may be scattered.

[ patent document 1 ] Japanese patent application laid-open No. 9-101677

Disclosure of Invention

The invention provides a developing device, a process cartridge, and an image forming apparatus, which can improve the performance of preventing or inhibiting developer on the surface of a developer carrier from scattering to the periphery of the developing device.

In order to achieve the above object, an aspect of the present invention provides a developing device including: end sealing members which abut against outer peripheral surfaces of both end portions in the longitudinal direction of the rotating developer carrier; and an inlet seal member that abuts the developer carrier at a center portion in the longitudinal direction and at an end portion in the longitudinal direction, wherein the end seal member has a cutout portion in the center portion on an upstream side in a rotation direction of the developer carrier, and the inlet seal member covers an edge portion in the longitudinal direction of the cutout portion.

According to the present invention, the end seal member prevents or suppresses the developer from scattering from the longitudinal end of the developer carrier, and the inlet seal member overlapping the longitudinal end of the end seal member prevents or suppresses the developer from scattering, thereby preventing the developer from scattering around the developing device and improving the performance of the developer suppression.

Drawings

Fig. 1 is a schematic diagram illustrating a developing device according to an embodiment of the present invention.

Fig. 2 is a perspective view of a portion of the developer carrier in which the end seal member and the inlet seal member are disposed in an opposing relationship as shown in fig. 1, with respect to one end in the longitudinal direction of the developer carrier.

Fig. 3 is a development view for explaining the opposing relationship of the end seal member and the inlet seal member shown in fig. 2.

Fig. 4 is a schematic view showing a positional relationship between an end sealing member and an inlet sealing member provided in the developing device shown in fig. 1, as viewed from the longitudinal direction end side of the inlet sealing member.

Fig. 5(a) - (D) are oblique views for explaining different actions when the configuration of the end seal member and the inlet seal member shown in fig. 2 is adopted and not adopted.

Fig. 6 is a simplified perspective view for explaining the surface structure of the end seal member shown in fig. 5.

Fig. 7 is a perspective view of a portion of another example of the positional relationship between the end seal member and the inlet seal member used in the developing device shown in fig. 1, with respect to one end in the longitudinal direction of the developer carrier.

Fig. 8(a) and (b) are developed views for explaining the facing relationship between the end seal member and the inlet seal member shown in fig. 7.

Fig. 9(a) - (C) are developed views for explaining other examples of the arrangement relationship of the end sealing member and the inlet sealing member used in the developing device shown in fig. 1.

Fig. 10(a) and (B) are schematic views for explaining an example of an image forming apparatus including a process cartridge on which an example of the developing device according to the embodiment of the present invention is mounted.

Fig. 11 is a partial perspective view of a virtual example for explaining the arrangement relationship between the end seal member and the inlet seal member shown in fig. 2, with respect to one end in the longitudinal direction of the developer carrier.

Fig. 12 is a perspective view for explaining a problem in a virtual example of the end sealing member.

Detailed Description

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. As shown in fig. 1, the developing device 1 includes a developer carrier 2, which is exposed to the outside of the developing tank 1A at a portion facing the developing tank 1A and the latent image carrier 4 and on which a developer is placed, and a developer supply member 3, which is disposed in the developing tank 1A and supplies the developer in the developing tank 1A to the developer carrier 2. The developing device 1 includes a regulating blade 5 for regulating the amount of the developer placed on the developer carrier 2 and supplied to the latent image carrier 4 to a predetermined amount. The developing device 1 is provided with an end seal member 6 and an inlet seal member 7 as members for preventing scattering due to leakage of the developer in a longitudinal direction perpendicular to the sheet of fig. 1, that is, in a Y direction of fig. 2. The Y direction is an axial direction of the developer carrier 2 perpendicular to the X direction indicated by an arrow indicating a designated rotation direction of the developer carrier 2 in fig. 1.

The developer carrier 2 is a roller having a rubber layer on the surface thereof and rotatable in the X direction. As the developer to be placed on the developer bearing member 2, for example, a one-component magnetic developer is used in the present embodiment. During the rotation of the developer carrier 2 in the X direction, the developer drawn from the developer supply member 3 and loaded on the developer carrier 2 is supplied to the latent image carrier 4. The developer supply member 3 is a sponge roller whose rotational direction is set to move in the opposite Z direction at the position opposite to the developer carrier 2, but may be formed of other material as long as it is an elastic member.

The regulating blade 5 is an elastic member that can be brought into contact with the surface of the developer carrier 2 with a predetermined pressure, and specifically, is a metal plate spring. The regulating blade 5 thins the developer on the surface of the developer carrier 2 to a predetermined thickness, and promotes frictional contact between the developer passing between the regulating blade 5 and the developer carrier 2 to triboelectrically charge the developer.

The end sealing members 6 are provided in a pair facing each end of the developer carrier 2 in the Y direction (see fig. 2). The end seal member 6 extends in the X direction shown in fig. 2 and 3, and has a predetermined width D, L as the maximum width in the X direction and the Y direction on the surface facing the developer bearing member 2. The end sealing members 6 abut on the outer peripheral surfaces of both ends of the developer carrier 2 in the Y direction, and fill the gap between the developer carrier 2 and the developing tank 1A along the outer peripheral surface of the developer carrier 2. As described above, the end sealing member 6 is a member for shielding the developer to be leaked from each end of the developer carrier 2 in the Y direction. In order to improve the close contact between the end seal member 6 and the developer carrier 2, a structure is adopted in which felt or brush having high sliding mobility is laminated on the surface of a base layer such as a sponge, or a structure is adopted in which only felt or brush is provided without a base layer.

The inlet seal member 7 extends in the Y direction, and the center portion in the Y direction abuts the developer carrier 2 and the end portions in the Y direction abut the end seal members 6. The end of the inlet seal member 7 in the Y direction is sandwiched between the developer carrier 2 and the end seal member 6 as shown in fig. 4.

The bottom end of the inlet seal member 7 is directly joined to the developing tank 1A over the entire range in the Y direction by a double-sided tape, an adhesive agent, or the like, and the free end is brought into contact with the developer carrier 2 at a pressure capable of collecting the developed developer into the developing tank 1A without being scraped off the developer carrier 2. The inlet seal member 7 is made of a sheet material having plasticity or elasticity, such as PET (polyethylene terephthalate), which the free end can contact, under a pressure that prevents the developer from leaking from the inside of the developing tank 1A with respect to the developer carrier 2 in addition to the recovery of the developer. The bottom end of the inlet seal member 7 is directly stuck to the developing tank 1A side, and abuts against the developer carrier 2 at each end in the Y direction (see fig. 2) of the free end thereof, and the end in the X direction of the opposite surface thereof abuts against the end seal member 6. At the abutment position of the inlet seal member 7 and the end seal member 6, the free end of the inlet seal member 7 is abutted with the developer carrier 2 by the thickness of the end seal member 6.

As shown in fig. 3, the end seal member 6 has a cut-out portion 6A at the Y-direction center (inside the developing device) on the upstream side in the X-direction, which is equal to or less than the specified width L of the end seal member 6 in the Y-direction. Thus, compared to the example (see fig. 11) in which the width in the Y direction is L, the end seal member 6 has the cutout portion 6A, and therefore the contact area thereof is smaller than the area facing the inlet seal member 7 (the contact area without the cutout portion 6A).

In fig. 2 and 3, the cutout portion 6A has a parallel side 6A1 parallel to the X direction, and a crossing side 6A2 extending from the downstream end of the parallel side 6A1 in the X direction toward the center side in the Y direction. The intersecting edge 6a2 is a vertical edge (denoted by the symbol 6a20 for simplicity) perpendicular to the parallel edge 6a 1.

The inlet seal member 7 is abutted against the end seal member 6 in a state of covering at least the edge portions (the parallel sides 6A1 and the intersecting side 6A2) of the cutout portion 6A. Specifically, as shown in fig. 3, the inlet seal member 7 covers the end seal member 6 in the X direction and the Y direction in a state of surrounding the edge portion of the cutout portion 6A, and forms covered

portions

6B and 6C. The covered portion 6B is a portion of the inlet seal member 7 that covers the portion of the end portion side in the Y direction of the cut-out portion 6A of the end seal member 6, and is the most upstream side portion of the end seal member 6 in the X direction. The covered portion 6C is a portion of the inlet seal member 7 that covers the downstream side of the cut-out portion 6A of the end seal member 6 in the X direction, and is the most central portion of the end seal member 6 in the Y direction. As shown in fig. 3, the length of the coated portion 6B is set to be approximately 3mm between the end sealing member 6 and the inlet sealing member 7 and between the end sealing member 6 and the developing tank 1A (see fig. 4) in order to secure a coating material of a sealant (sealant) for preventing leakage of the developer in the Y direction. In fig. 3, the coating material of the sealant is shown as a sealant coating position. Since the sealant is deformed by the heat of the developer, the range of the sealant application position is the covered portion 6B of the end portion in the Y direction farthest from the inside of the developing device. Since the inlet seal member 7 can be placed and supported in an easily bendable state by securing a small support area, the length of the covered portion 6C along the X direction of the end seal member 6 may be about 1 mm. By reducing the length of the covering portion 6C as much as possible in this manner, when the inlet seal member 7 is prevented from coming off the end seal member 6, the inlet seal member 7 is easily bent toward the filling cut-out portion 6A at a position facing the cut-out portion 6A. In other words, the inlet seal member 7 facing the cut-out portion 6A may be easily bent to the cut-out portion 6A side because there is no backing of the end seal member 6. Thereby, when the developer enters between the developer carrier 2 and the inlet seal member 7, the inlet seal member 7 is bent in a direction in which the developer escapes after being pressed, and the rise in pressure at the formation position of the cutout portion 6A is alleviated.

The mounting range of the developer in the Y direction on the developer carrier 2 is a range between the end sealing members 6. However, the mounting range of the developer in the Y direction (inside of both ends of the developer carrier 2 in the Y direction) may flow into the Y direction due to the rotational movement of the developer carrier 2, or the like. Thereby causing the developer in the end portion to leak. Particularly, in the case of the developer mounting system using the magnetic brush, since the magnetic lines of force are expanded to the outside in the Y direction, the developer may flow into the range from the outside in the Y direction to the end sealing member 6. In the range where the end sealing member 6 is located, when a part of the developer enters between the developer carrier 2 and the inlet sealing member 7, the inlet sealing member 7 is pushed by the developer and the pressure of this part is raised. In the case of the configuration shown in fig. 11 in which the cutout portion 6A is not provided, when the pressure of the developer increases in the portion thereof due to the reaction force from the backing portion, the developer is dammed, and movement of the developer into the developing tank 1A through the leading end (free end) of the inlet seal member 7 is hindered and dammed. When the developer is dammed, the developer moved from behind at this position causes a further increase in pressure and causes the developer to leak out of the developing device.

Then, as shown in the imaginary example shown in fig. 12, it is considered that the pressure of the portion of the inlet seal member 7 abutting the end seal member 6 in the Y direction and the pressure of the portion not abutting the end seal member 6 are balanced by making the thickness T1 of the surface of the end seal member 6 abutting the inlet seal member 7 on the upstream side in the X direction smaller than the thickness T0 on the downstream side. However, in the case of such a configuration, the processing state of the material used for the end sealing member 6 must be changed slightly, which leads to an increase in cost. Further, when the sponge used for the bottom layer of the end sealing member 6 is thin, the processing becomes difficult, and the desired result cannot be obtained. In addition, it is also conceivable to change the material of the end seal member 6 itself instead of changing the thickness by changing the surface structure of the end seal member 6.

However, when the end seal member 6 is manufactured by resin molding, it is inevitable to increase the difficulty and cost in manufacturing the resin molded product. When the inlet seal member 7 is easily bent by changing the thickness or material of the end seal member 6, the movement space of the inlet seal member 7 is enlarged by the change at the Y-direction end of the developer bearing member 2. Therefore, the developer leaks out toward the outside of the Y-direction end.

In contrast, in the configuration of the present embodiment shown in fig. 2 and 3, the cutout portion 6A is provided on the developing device inner side (Y-direction center portion direction) of the end sealing member 6, and the difference in contact area with respect to the opposing area allows the pressure rise to be alleviated and the scattering of the developer to be prevented or suppressed by a simple configuration in which the non-contact portion is easily bent. That is, since the inlet seal member 7 is relatively easily bent toward the cutout portion 6A on the side of the end seal member 6, a pressure rise between the developer carrier 2 and the inlet seal member 7 due to the developer being pressed is alleviated. Thus, the developer moved from the developer carrier 2 side is easily collected into the developing tank 1A, and the scattering of the developer from the end of the developer carrier 2 in the Y direction and the scattering of the developer toward the periphery of the developing position by the end sealing member 6 are prevented or suppressed, respectively.

On the other hand, in the present embodiment, the following configuration is adopted when the inlet seal member 7 is brought into contact with the end seal member 6 in a state where the edge portion of the cut-out portion 6A in the end seal member 6 is covered. That is, the inlet seal member 7 covers the end seal member 6 in the Y direction and the X direction including the cutout portion 6A. By providing the overlapping portion of the covered

portions

6B, 6C, no gap into which the developer enters is provided between the cut-out portion 6A and the inlet seal member 7.

Thus, as shown in fig. 5(a), since the inlet seal member 7 covers at least the edge portion of the cut-out portion 6A of the end seal member 6, the gap S shown in fig. 5(B) into which the developer enters is not formed between the inlet seal member 7 and the cut-out portion 6A. If there is the gap S, when the developer moves with the rotation of the developer carrier 2 in the X direction (see fig. 3), the developer may be scraped off by the edge portion of the peripheral portion of the cutout portion 6A and accumulated in the gap S. In the Y direction of the cut-out portion 6A, the developer at the center of the gap S is pushed out and overflows by the subsequent developer entering the gap S as shown by an arrow Q in fig. 5(C), and moves to the developing region center side. On the other hand, the developer accumulated on the end portion side in the gap S in the Y direction is not easily overflowed and is likely to accumulate all the time, and as a result, the developer is solidified as shown in fig. 5 (D). The solidified developer also scrapes off the developer moving in the X direction, and thus an increase in the amount of deposition may be caused. The solidified developer with an increased amount of accumulation may damage the surface of the developer carrier 2 or scrape off the developer placed on the developer carrier 2, thereby causing an abnormal image such as a streak to be generated on the image.

As described above, by covering the inlet seal member 7 with respect to the cut-out portion 6A of the end seal member 6, damage to the developer carrier 2 can be prevented or suppressed, and further, generation of an abnormal image can be prevented or suppressed, so that the performance of preventing the developer from scattering to the peripheral portion of the developing device can be improved.

The end sealing member 6 has a structure in which the developer is oriented toward the center side in the Y direction by a frictional force generated when contacting the developer carrier 2. That is, as shown by an arrow in fig. 6, the end seal member 6 is provided with bristles B that are implanted in a direction capable of guiding the developer toward the Y-direction center side corresponding to the center side of the developing region on the surface facing the inlet seal member 7. The brush bristles B are arranged in such a manner that the developer is less likely to move to the outside in the Y direction in the end seal member 6 than the end seal member 6 due to the direction of bristle implantation. Thus, the end sealing member 6 is provided in the developing device 1 as a multifunctional part not only simply shielding leakage of the developer but also by giving it a guide function different from the shielding function.

Next, another embodiment of the cut-out portion (hereinafter, referred to as a symbol 6A' for convenience) in the end sealing member 6 will be described. In the configurations of fig. 7 and 8, the configuration of the cut-out portion 6A' provided in the end sealing member 6 is different. The cutout portion 6A' has a parallel side 6A1 parallel to the X direction, and as shown in fig. 7 and 8, has a sloped side 6A21 inclined toward the downstream side in the X direction with respect to the parallel side 6A 1.

As shown in fig. 8, the inlet seal member 7 includes a covered portion 6B ' and a covered portion 6C ' covering the end seal member 6 and including a cut-out portion 6A ' in the X direction and the Y direction. In this configuration, since there is the inclined side 6a21 intersecting the parallel side 6a1, the effect of moving the developer along the inclined side 6a21 is more than the effect of moving the developer by the end seal member 6 as shown in fig. 3. That is, the developer between the inlet seal member 7 and the developer carrier 2 in the cut-out portion 6A' becomes easily guided toward the Y-direction center side by the rotational friction of the developer carrier 2 that rotates in contact with the inlet seal member 7. Thus, since the vertical side 6a20 shown in fig. 5 in which the gap S is generated is not described, but the inclined side 6a21 serves as a guide surface for the developer, it is possible to suppress accumulation of the developer and prevent and/or suppress damage to the developer carrier 2 and generation of an abnormal image.

As shown in fig. 8 a, a covered portion 6C 'is provided between the cut-out portion 6A' and the inlet seal member 7 to avoid the occurrence of a gap (see reference symbol S in fig. 5) in the X direction. When the covered portion 6C' is provided, the overlapping region length L1 of the end seal member 6 and the inlet seal member 7 can be extended in the Y direction and shielding efficiency can be improved. Fig. 8(b) shows a state where the cover 6C' is not provided. When the inlet seal member 7 abuts against the end seal member 6, the length L1 of the region where the end seal member 6 and the inlet seal member 7 overlap in the Y direction is shorter than that shown in fig. 8 (a). Thus, leakage of the developer (movement in the direction indicated by the symbol PL) from the center side to the end side in the Y direction between the end seal member 6 and the inlet seal member 7 is less effective in shielding as the length in the Y direction in which the both

seal members

6 and 7 overlap is shorter, and is better as the length is longer.

When the inlet seal member 7 is disposed so as not to generate the gap S into which the developer enters as shown in fig. 8(a), the movement of the developer from the center to the end side in the Y direction is easily suppressed by increasing the length of the overlap between the end seal member 6 and the inlet seal member 7 in the Y direction. This can substantially reliably prevent the developer from scattering outward from the end sealing member 6. On the other hand, even when the inlet seal member 7 is disposed in the gap S where the developer enters as shown in fig. 8(B), the developer is smoothly moved toward the center in the Y direction by the provision of the inclined side 6a21, unlike the case of having the intersecting side as shown in fig. 5 (B). Thereby, in the position of the end sealing member 6, retention of the developer is prevented or suppressed, and scattering of the developer at the Y-direction end is prevented or suppressed. That is, by providing the inclined side 6a21, even if the overlapping region length L1 is shorter than that shown in fig. 8(a), scattering of the developer at the Y-direction end portion can be prevented or suppressed.

The parallel sides 6A1 parallel to the X direction of the

cutouts

6A and 6A' substantially coincide with each other in the Y-direction horizontal cross section and the Y-direction end surface of the developer carrier 2. More precisely, the parallel side 6a1 is provided with a margin (gap) at some Y-direction end side of the end surface of the developer carrier 2 so as not to generate a rotational load of the developer carrier 2, in order to make the parallel side 6a1 parallel to the end surface. Accordingly, when the outer peripheral surface of the end portion of the developer carrier 2 presses the inlet seal member 7, the inlet seal member 7 is bent, and the bent portion engages with the parallel side 6a1, so that the rotational load of the developer carrier 2 can be reduced and the developer can be prevented from scattering toward the outside of the developing device. However, the end sealing member 6 is not necessarily provided with the parallel sides 6a1 as long as the end sealing member 6 has sufficient flexibility to reduce the rotational load of the developer carrier 2 and prevent the developer from scattering toward the outside of the developing device. For example, fig. 9 may be mentioned as an example of the edge portion of the cutout portion 6A. That is, the edge portion of the cutout portion 6A may be formed as a linear inclined side 60 (see fig. 9 a) or a curved inclined side 60' (see fig. 9B) having a curvature radius R, which is inclined with respect to the X direction and the Y direction and widens the width of the end seal member 6 in the Y direction toward the downstream side in the X direction. With this configuration, even if the developer between the developer carrier 2 and the inlet seal member 7 spreads to the outside of the end of the developer carrier 2, the developer is moved toward the center in the Y direction by the inclined edges 60, 60' of the end seal member 6 to the outside of the end of the developer carrier 2, so that the developer can be prevented from scattering to the outside of the developing device. In addition, also in this example, as shown in fig. 9(C), the inlet seal member 7 may be disposed so as to generate a gap S into which the developer enters. In this configuration, although the above-described covering edge 6B is not provided, it is needless to say that the above-described application of the sealant may be performed at a position on one side in the Y direction of the X direction upstream side end portion corresponding to the starting end of the inclined edge.

The developing device 1 having the above-described configuration can be incorporated in, for example, a process cartridge 101 shown in fig. 10(B), and the process cartridge 101 is easily detachably provided in the image forming apparatus 100 as an image forming unit of the image forming apparatus 100 shown in fig. 10 (a). The image forming apparatus 100 shown in fig. 10(a) is, as an example, a printer having a plurality of colors, that is, having image forming portions of respective colors of yellow, magenta, cyan, black, and the like, and capable of forming a color image. The process cartridges 101 are provided so as to correspond to the respective colors. Each process cartridge 101 has photosensitive drums (for the sake of simplicity, roman letters indicating colors are given to reference numeral 4 in fig. 1) 4Y, 4M, 4C, and 4K as latent image carriers. The

photosensitive drums

4Y, 4M, 4C, and 4K of the process cartridges 101 are arranged in parallel along one extended surface of the intermediate transfer belt 111 provided in the intermediate transfer device 110. The intermediate transfer belt 111 is wound around the driving

rollers

110A and 110B, respectively, and moves in the direction of the arrow shown in the figure.

Since the configurations of the process cartridges 101 are the same, the following configuration will be described with respect to the yellow image forming portion having the 00 photosensitive drum 4Y. Around the photosensitive drum 4Y, a charging device 10Y, a writing device 11Y, a developing device 1Y, a primary transfer device 12Y, and a cleaning device 13Y for performing an image forming process are arranged along the rotation of the photosensitive drum 4Y. Further, as in 10(B), reference numeral 13Y1 denotes a cleaning blade provided in the cleaning device 13Y. As shown in fig. 10(B), the charging device 10Y, the writing device 11Y, the developing device 1Y, the primary transfer device 12Y, and the cleaning device 13Y are collectively housed in the process cartridge 101, except for the writing device 11Y and the primary transfer device 12Y.

In fig. 10(a), the images formed by the process cartridges 101 are sequentially transferred onto the intermediate transfer belt 111 by the

primary transfer devices

12Y, 12M, 12C, and 12K to form a superimposed image. In the intermediate transfer belt 111, secondary transfer devices 14 for collectively transferring the superimposed images onto a recording medium P such as recording paper are arranged in opposite directions. The

primary transfer devices

12Y, 12M, 12C, and 12K and the secondary transfer device 14 transfer images by supplying power from transfer bias

power sources

112 and 113. A recording medium supply device 115 is provided inside the image forming apparatus 100. The feeding device 115 includes a cartridge 115A that houses a recording medium P such as recording paper, a feed roller 115B that feeds the recording medium from the cartridge 115A, and a conveying mechanism 115C that conveys the fed recording medium P toward the position of the secondary transfer device 14.

The recording medium P having completed the entire transfer by the secondary transfer is discharged to the paper discharge portion 100A by the discharge roller 17 after the image fixing by the fixing device 116. When the intermediate transfer belt 111 has moved to the position where the transfer is completed, the belt cleaning device 18 removes the untransferred toner or foreign matter and prepares for the next image transfer.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above specific embodiments, and various modifications and changes can be made within the spirit of the present invention described in the scope of the claims unless otherwise specified. For example, it is also possible to avoid the damming phenomenon of the developer corresponding to the amount of the accumulated developer by using the shape memory alloy in the inlet seal member. That is, as the amount of the developer deposited increases, the inlet seal member generated by the developer carrier has a greater chance of being rubbed by sliding, and frictional heat is likely to be generated. When the amount of the developer deposited increases, the inlet seal member returns to a predetermined initial shape by frictional heat generated by sliding friction of the developer, and then the dammed developer flicks, thereby preventing or suppressing the scattering of the developer. The effects described in the embodiments of the present invention are merely the best effects produced by the present invention, and the effects of the present invention are not limited to those described in the embodiments of the present invention.

Claims

1. A developing device, comprising:

end sealing members which abut against outer peripheral surfaces of both end portions in the longitudinal direction of the rotating developer carrier;

an inlet seal member having a center portion in the longitudinal direction in contact with the developer bearing member and having an end portion in the longitudinal direction in contact with the end seal member,

wherein the end sealing member has a cutout portion in a central portion of the developer carrier on an upstream side in a rotation direction thereof,

the inlet seal member covers an edge portion in the longitudinal direction of the cutout portion, the edge portion including at least an inclined edge inclined to the rotation direction and the longitudinal direction and toward an upstream side in the rotation direction so as to narrow a width of the end seal member in the longitudinal direction.

2. The developing device according to claim 1, characterized in that:

the edge portion includes a parallel side parallel to a rotation direction of the developer bearing member, and an intersecting side from a downstream side end portion of the parallel side in the rotation direction toward the central portion side, and the intersecting side is the inclined side inclined toward a downstream side in the rotation direction with respect to the parallel side.

3. The developing device according to claim 1, characterized in that:

the edge portion is a linear or curved inclined side inclined in the rotation direction and the longitudinal direction and formed to narrow the width of the end seal member in the longitudinal direction toward the upstream side in the rotation direction.

4. The developing device according to any one of claims 1 to 3, characterized in that:

the inlet seal member covers the edge portion and the covered portion on the upstream side in the rotation direction of the end seal member or the covered portion on the central portion side in the longitudinal direction in the rotation direction and the longitudinal direction.

5. The developing device according to any one of claims 1 to 4, characterized in that:

the end seal member is provided with brush bristles on a surface facing the inlet seal member, the brush bristles being capable of being flocked in a direction in which the developer is guided toward the center portion side.

6. The developing device according to claim 2, characterized in that:

the parallel sides are arranged in positions that coincide with the end portions of the developer carrier in the longitudinal direction.

7. A process cartridge, characterized in that:

the developing device according to any one of claims 1 to 6 including a latent image carrier and the developer carrier is integrally housed.

8. An image forming apparatus, characterized by comprising:

the developing device according to any one of claims 1 to 6, or the process cartridge according to claim 7.