JP2023055234A - image forming device - Google Patents

Abstract

The present invention relates to a developing device having a developer regulating member made of resin. SOLUTION: The sheet member is provided over the entire region of the developing rotator corresponding to the maximum image area in which an image can be formed on the image carrier. A space partitioned by the developing rotor, the developer regulating member, and the sheet member is formed over the entire area, and the outer side of the developing rotor in the rotation axis direction of the area corresponding to the maximum image area of the developing rotor is formed. , the developer regulating member is provided with a first sealing portion and a second sealing portion at positions facing one end and the other end in the direction of the rotation axis of the developing rotator, respectively. The first sealing portion covers one end portion of the space in the longitudinal direction outside the region of the developing rotator corresponding to the region in the direction of the rotation axis of the developing rotator, and the second sealing portion covers the other longitudinal end of the space. [Selection drawing] Fig. 6

Description

The present invention relates to an image forming apparatus equipped with a developing device having a developer regulating member made of resin.

The developing device includes a developing container containing a developer containing toner and carrier, and a developing rotary member that carries and conveys the developer to a developing region for developing an electrostatic image formed on an image carrier. While the developing device is in operation, air flows into the developing container as the developing rotator rotates. In particular, when the rotation speed of the developing rotor is increased to speed up the process speed, the amount of air flowing into the developing container per unit time increases, so the internal pressure in the developing container increases to a large extent. Become. When the internal pressure inside the developing container increases, the force of the air that is about to be discharged from the inside of the developing container toward the outside of the developing container through the opening of the developing container increases. The amount of scattered toner tends to increase.

In recent years, there has been known a developing device having a resin-made developer regulating member that regulates the amount of developer carried on the surface of the developing rotator (see Patent Document 1). ). The resin-made developer regulating member disclosed in Patent Document 1 has a space formed between the developing device and the image bearing member, which is arranged so as to face the developing rotary member so as not to be in contact with the developing rotary member. A sheet member is attached for sealing at least part of the This sheet member has an area of the developing rotator corresponding to the maximum image area of the image areas capable of forming an image on the surface of the image carrier (maximum image area of the developing rotator) with respect to the rotation axis direction of the developing rotator. ) facing the developing rotary member.

JP 2019-101304 A

In the configuration of Patent Document 1, when the layer thickness of the developer passing through the gap between the developing rotor and the resin developer regulating member is regulated by the sheet member, the developer regulating member prevents the developer regulating member from It is possible to suppress scattering of toner outside the developing container in the maximum image area of . However, in the configuration of Patent Document 1, the sheet member is not provided outside the maximum image area of the development rotor with respect to the rotation axis direction of the development rotor. There is a tendency for the air in the developing container to run sideways toward the ends. As the amount of air in the developing container running sideways from the center to the end of the developing rotor increases, the air containing the toner flows from both ends of the developing rotor in the direction of the rotating shaft to the developing container. Easier to get out. As a result, there is a possibility that the amount of toner that scatters outside the developing container from both ends in the direction of the rotation axis of the developing rotator increases.

The present invention has been made in view of the above problems. SUMMARY OF THE INVENTION It is an object of the present invention to provide a developing device having a developer regulating member made of resin, and to provide a configuration capable of reducing the amount of toner scattered outside the developing container from both ends in the direction of the rotation axis of the developing rotator. That's what it is.

In order to achieve the above object, an image forming apparatus according to one aspect of the present invention has the following configuration. That is, it accommodates a rotatable image carrier on which an electrostatic image is formed, an exposure device for exposing the image carrier to form an electrostatic image on the image carrier, and a developer containing toner and carrier. a developing rotator for carrying and conveying the developer for developing an electrostatic image formed on the image carrier; a developer regulating member made of resin for regulating the amount of developer carried on a body; The developer is disposed facing the developing rotary member downstream in the direction and upstream in the rotational direction of the developing rotary member from a position on the developing rotary member at which the developing rotary member is closest to the image bearing member, and a sheet member provided on a regulating member; The sheet member extends over the entire area of the developing rotator corresponding to the maximum image area in which an image can be formed on the image carrier. a space partitioned by the developing rotator, the developer regulating member, and the sheet member is formed over the entire area of the developing rotator corresponding to the maximum image area, and Outside the region corresponding to the maximum image area in the rotation axis direction of the development rotor, the developer regulating member is provided at a position facing one end portion of the development rotor in the rotation axis direction. A first sealing portion is provided, and a second sealing portion is provided at a position facing the other end in the direction of the rotation axis of the developing rotor, corresponding to the maximum image area. The first sealing portion covers one end portion of the space in the longitudinal direction outside the region of the developing rotor in the direction of the rotation axis of the developing rotor, and the second sealing portion covers the other longitudinal end of the space.

According to the present invention, it is possible to reduce the amount of toner that scatters outside the developing container from both ends in the rotation axis direction of the developing rotator in the developing device having the developer regulating member made of resin.

1 is a cross-sectional view showing the overall configuration of an image forming apparatus according to a first embodiment; FIG. 1 is a perspective view showing the configuration of a developing device according to a first embodiment; FIG. 2 is a cross-sectional view showing the configuration of the developing device according to the first embodiment; FIG. FIG. 4 is a cross-sectional view showing the configuration in the vicinity of the regulating blade according to the first embodiment; FIG. 5 is a diagram showing how scattered toner is deposited in the vicinity of the regulation blade according to the first embodiment; FIG. 4 is a perspective view showing the configuration of a pair of sealing portions provided on the regulating blade according to the first embodiment; FIG. 11 is a perspective view showing the configuration of a pair of sealing portions provided on a regulating blade according to a second embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the present invention according to the claims, and not all combinations of features described in the embodiments are essential for the solution of the present invention. do not have. The present invention can be implemented in various applications such as printers, various printing machines, copiers, facsimiles, and multi-function machines.

[First Embodiment]
(Overall Configuration of Image Forming Apparatus)
First, the overall configuration of the image forming apparatus according to the first embodiment of the invention will be described with reference to the cross-sectional view of FIG. FIG. 1 is a cross-sectional view of a color image forming apparatus using an electrophotographic system. An image forming apparatus 60 is of a so-called intermediate transfer tandem system in which four-color image forming units 600 are arranged to face an intermediate transfer belt 61 . For example.

The transfer material S is stacked in a transfer material storage section 62 and is fed by a feeding means 63 at the timing of image formation. Here, the feeding means 63 employs, for example, a friction separation method using a feeding roller or the like. The transfer material S sent out by the feeding means 63 is conveyed to the registration rollers 65 arranged in the middle of the conveying path 64 . After skew correction and timing correction are performed by the registration rollers 65, the transfer material S is sent to the secondary transfer portion. The secondary transfer portion is a transfer nip formed by a secondary transfer inner roller 66 and a secondary transfer outer roller 67 facing each other. Adsorb the toner image.

A process of forming an image sent to the secondary transfer portion at the same timing as the process of conveying the transfer material S to the secondary transfer portion described above will be described. The image forming section 600 mainly includes a photoreceptor drum 1 (image carrier), a developing device 2, a charging device 3, a primary transfer device 4, a photoreceptor cleaner 5, and the like. The surface of the photosensitive drum 1 which is rotationally driven is uniformly charged in advance by the charging device 2, and then an electrostatic latent image (electrostatic image) is formed by the exposure device 68 which is driven based on the image information signal. is formed. Next, the electrostatic latent image formed on the photosensitive drum 1 is visualized through toner development by the developing device 2 . After that, the primary transfer device 4 applies a predetermined pressure and an electrostatic load bias, and the toner image is transferred onto the intermediate transfer belt 61 . Finally, a small amount of untransferred toner remaining on the photoreceptor drum 1 is collected by the photoreceptor cleaner 5 to prepare for the next image forming process. In the case of FIG. 1, the image forming unit 600 described above has four sets of yellow (Y), magenta (M), cyan (C), and black (Bk). However, the number of colors is not limited to four colors, and the arrangement order of colors is not limited to this.

Next, the intermediate transfer belt 61 is described. The intermediate transfer belt 61 is an endless belt that is stretched by a tension roller 6, a secondary transfer inner roller 66, and driven rollers 7a and 7b, and is conveyed and driven in the direction of arrow C in FIG. Here, the inner secondary transfer roller 66 also serves as a drive roller for driving the intermediate transfer belt 61 . The image forming process of each color processed in parallel by the Y, M, C, and Bk image forming units 600 is performed at the timing of sequentially superimposing on the upstream color toner image primarily transferred onto the intermediate transfer belt 61 . As a result, a full-color toner image is finally formed on the intermediate transfer belt 61 and conveyed to the secondary transfer portion. The transfer cleaner device 8 collects the transfer residual toner after passing through the secondary transfer portion.

Through the conveying process and the image forming process described above, the timings of the transfer material S and the full-color toner image are matched at the secondary transfer portion, and the secondary transfer is performed. After that, the transfer material S is conveyed to the fixing device 9, and the toner image is melted and fixed on the transfer material S by a predetermined amount of pressure and heat. The transfer material S on which the image has been fixed in this manner is discharged as it is onto the discharge tray 601 by the forward rotation of the discharge roller 69, or a two-sided image formation is performed. When double-sided image formation is required, the forward rotation of the discharge roller 69 conveys the transfer material S until the rear end passes through the switching flapper 602, and then the discharge roller 69 is reversely rotated to switch the leading and trailing ends. , is conveyed to the double-sided conveying path 603 . After that, it is sent to the conveying path 64 again by the re-feeding roller 604 in synchronism with the transfer material S of the succeeding job conveyed by the feeding means 63 . The subsequent transportation and the image forming process for the back surface of the transfer material S are the same as those for the front surface of the transfer material S described above, so the description thereof will be omitted.

(Structure of developing device)
Next, the configuration of the developing device 2 according to the first embodiment will be described with reference to the perspective view of FIG. 2 and the cross-sectional view of FIG.

The developer container 20 contains a two-component developer containing toner and carrier (hereinafter simply referred to as developer). A portion of the developer container 20 facing the photosensitive drum 1 is open, and a developing sleeve 21 (developer carrier, developing rotator) is rotatably disposed so as to be partially exposed through the opening. there is The developing sleeve 21 carries and conveys a developer to a developing area where an electrostatic latent image formed on the surface of the photosensitive drum 1 is developed. The developing sleeve 21 is made of a non-magnetic material, and a magnet 22 as a magnetic field generating means is fixed inside the developing sleeve 21 so as not to rotate.

A regulating blade 23 (developer regulating member) is attached to the developing container 20 to regulate the amount of developer carried on the developing sleeve 21 (on the developing rotator). In the first embodiment, as shown in FIG. 3, the position on the developing sleeve 21 where the developing sleeve 21 is closest to the regulating blade 23 is the position on the developing sleeve 21 where the developing sleeve 21 is closest to the photosensitive drum 1 . below the position.

The regulating blade 23 is a resin regulating blade 23 molded from resin, and has a rigidity that allows it to be bent. The regulation blade 23 is adhered to the developer container 20 with an adhesive while the regulation blade 23 is bent so that the gap (shortest distance) between the developing sleeve 21 and the regulation blade 23 is within a predetermined range. .

The developing sleeve 21 rotates in the direction of arrow E in FIG. 3 to convey the developer toward the regulating blade 23 . The developer is sheared by the regulating blade 23 and its amount is regulated, and passes through the gap between the developing sleeve 21 and the regulating blade 23 to form a developer layer with a predetermined layer thickness on the developing sleeve 21 . The developer layer formed on the developing sleeve 21 is carried and transported to the developing area facing the photoreceptor drum 1 to develop the electrostatic latent image formed on the surface of the photoreceptor drum 1 .

The developer container 20 is partitioned into a developing chamber 11 (first developer containing chamber) and a stirring chamber 12 (second developer containing chamber) by a partition wall 15 . The developing chamber 11 and the stirring chamber 12 extend along the rotation axis direction of the developing sleeve 21 . Both ends of the partition wall 15 do not reach the side walls at both ends in the longitudinal direction inside the developing container 20, thereby acting as a communication portion between the developing chamber 11 and the stirring chamber 12 to allow the passage of the developer. A communication port is formed. A first screw 13 is arranged in the developing chamber 11 as a circulation conveying member for circulating the developer between the developing chamber 11 and the stirring chamber 12 . Further, in the stirring chamber 12 , a second screw 14 is arranged as a circulation conveying member for circulating the developer between the developing chamber 11 and the stirring chamber 12 .

The developing sleeve 21 , the first screw 13 , and the second screw 14 are configured to be connected and driven by a gear train, and rotate by receiving driving force from the driving gear provided in the developing device 2 . The rotation of the first screw 13 and the second screw 14 mixes and agitates the developer while circulating in the developer container 20 .

The replenishment toner is replenished from a replenishment port 17 provided on the most upstream side of the second screw 14 in the developer conveying direction. The replenishment toner replenished from the replenishment port 17 is conveyed into the stirring chamber 12 by the second screw 14, and then stirred and mixed with the developer, thereby uniformly diffusing into the developer while being triboelectrically charged. .

The replenishment toner replenished from the replenishment port 17 spreads uniformly in the developer while being triboelectrically charged. Regulated. When the toner having a low charge amount passes through the regulating blade 23, when the layer thickness of the developer is regulated by the regulating blade 21, the centrifugal force due to the rotation speed of the developing sleeve 21 and the magnetic brush of the carrier on the developing sleeve 21 are generated. The force of motion separates the toner from the carrier. If the toner separates from the carrier, there is a possibility that the toner may scatter outside the developer container 20 .

Further, while the developing device 2 is in operation, air flows into the developing container 20 as the developing sleeve 21 rotates. In particular, when the rotation speed of the developing sleeve 21 is increased to speed up the process, the amount of air flowing into the developing container 20 per unit time increases, so the internal pressure in the developing container 20 increases. becomes larger. When the internal pressure in the developer container 20 increases, the force of the air that is about to be discharged from the developer container 20 to the outside of the developer container 20 through the opening of the developer container 20 increases. The amount of toner scattering toward the outside of the container 20 tends to increase.

Therefore, in the first embodiment, as shown in FIG. 3, a sheet member 24 is attached on the regulation blade 23 made of resin to prevent the toner from scattering. Specifically, with respect to the rotation axis direction of the developing sleeve 21 , the developing sleeve 21 covers the entire area of the developing sleeve 21 corresponding to the maximum image area among the image areas in which an image can be formed on the surface of the photosensitive drum 1 . A sheet member 24 is provided opposite to 21 . In the first embodiment, if the sheet member 24 is provided over 95% or more of the area of the developing sleeve 21 corresponding to the maximum image area, the developing sleeve 21 corresponding to the maximum image area It is assumed that the sheet member 24 is provided over the entire area of .

Here, the configuration in the vicinity of the resin regulation blade 23 will be described with reference to the cross-sectional view of FIG. The sheet member 24 is a urethane sheet with a thickness of 100 μm, and is attached to the resin regulation blade 21 with a double-sided tape or an adhesive so as to form a predetermined angle on the regulation blade 23 . 25 is attached. In the first embodiment, an example in which the resin regulating blade 23 and the resin sheet sticking base 25 are integrally formed will be described. A modification in which the stand 25 is separate may be used.

The sheet member 24 is located at a position (development position) at which the development sleeve 21 is closest to the photosensitive drum 1 and downstream of the position (regulation position) at which the regulation blade 23 is closest to the development sleeve 21 in the rotational direction of the development sleeve 21 . is positioned upstream in the rotational direction of the developing sleeve 21 . Thereby, the sheet member 24 is arranged so as to seal the regulation blade 23 from the photosensitive drum 1 . The other end side of the sheet member 24 is attached to the sheet attaching table 25 so that the gap between the sheet member 24 and the developing sleeve 21 narrows from upstream to downstream in the rotation direction of the developing sleeve 21 . In addition, the other end of the sheet member 24 is attached to the sheet attaching table 25 so that one end of the sheet member 24 in the short direction is in contact with the developing sleeve 21 .

Here, how the toner accumulates in the vicinity of the regulation blade 23 made of resin will be described with reference to the cross-sectional view of FIG. Also, the configuration of a pair of sealing portions provided on the regulation blade 23 according to the first embodiment will be described with reference to the perspective view of FIG.

As shown in FIG. 6, the developing sleeve 21 and the regulating blade 23 extend over the entire region R of the developing sleeve 21 corresponding to the maximum image region among the image regions in which an image can be formed on the surface of the photosensitive drum 1 . and a space F partitioned by the sheet member 24 is formed. In the first embodiment, if the space F is formed over 95% or more of the area R of the developing sleeve 21 corresponding to the maximum image area, the developing sleeve 21 corresponding to the maximum image area It is assumed that a space F is formed over the entire region R of .

As shown in FIGS. 5 and 6, the space F contains toner separated from the developer when passing through the gap between the developing sleeve 21 and the regulating blade 23, and toner separated from the developer on the developing sleeve 21. deposited. As for the toner accumulated in the space F, when the toner layer of the developer grows to a certain amount, the air in the developing container 20 runs sideways from the central portion of the developing sleeve 21 in the direction of the rotational axis toward the ends.

As the amount of air in the developing container 20 running laterally from the center to the end of the developing sleeve 21 in the rotational axis direction increases, the air containing the accumulated toner from the end of the developing sleeve 21 in the rotational axis direction moves into the developing container. 20 It becomes easier to be discharged outside. Further, by the rotation of the developing sleeve 21, the air passes through the restricted position from the inside of the developing sleeve 20, flows into the enclosed space F, flows in the longitudinal direction, and flows from both ends of the developing sleeve 21 in the rotation axis direction to the developing container. There is a risk that the amount of toner scattered outside 20 will increase. As a result, there is a risk that the toner that scatters outside the developing container 20 from both ends of the developing sleeve 21 in the direction of the rotational axis may be carried by the airflow and adhere to the photoreceptor unit including the photoreceptor drum 1 . In recent years, from the viewpoint of serviceability, the photoreceptor unit and the like are sometimes provided in the image forming apparatus 60 in a user-replaceable manner. In such a configuration, if scattered toner adheres to the photoreceptor unit, there is a risk that the user will come in contact with the toner when replacing the photoreceptor unit and it will become dirty.

In the first embodiment, a resin regulating blade 23 is provided to reduce the amount of toner scattering outside the developing container 20 from both ends of the developing sleeve 21 in the rotation axis direction. 26 (first sealing portion, second sealing portion) are provided on the regulating blade 23 . Specifically, the sheet member 24 is provided over the entire area R of the developing sleeve 21 corresponding to the maximum image area in which an image can be formed on the photosensitive drum 1 . A space F partitioned by the developing sleeve 21, the regulating blade 23, and the sheet member 24 is formed over the entire area R of the developing sleeve 21 corresponding to the maximum image area. Further, outside the region R of the developing sleeve 21 corresponding to the maximum image region in the direction of the rotation axis of the development sleeve 21, the regulation blade 23 is provided at one end and the other end in the direction of the rotation axis of the development sleeve 21. A pair of sealing portions 26 are provided at opposing positions. Further, the sealing portion 26 (first sealing portion) covers one longitudinal end of the space F outside the region R of the developing sleeve 21 corresponding to the maximum image region in the rotation axis direction of the developing sleeve 21 . and the sealing portion 26 (second sealing portion) covers the other end of the space F in the longitudinal direction. In the first embodiment, regarding the developing device 2 having the regulation blade 23 made of resin, the amount of toner scattered outside the developing container 20 from both ends of the developing sleeve 21 in the rotation axis direction is reduced. The details are described below.

As shown in FIG. 6, a sealing portion 26 is provided at each of one longitudinal end and the other longitudinal end of the regulating blade 23 made of resin. Specifically, in the first embodiment, the pair of sealing portions 26 are fixed to the resin regulation blade 23 and the resin sheet attachment base 25 with double-sided tape or adhesive. Further, in the first embodiment, the thickness of the pair of sealing portions 26 in the direction of the rotation axis of the developing sleeve 21 is configured to be about 1 mm to 2 mm, which is a general thickness of resin parts, but is not limited to this. can be thicker.

The sealing portion 26 is provided at each of one end and the other end of the developing sleeve 21 in the direction of the rotation axis, and prevents scattering toner in the longitudinal direction of the space F surrounded by the regulating blade 23, the developing sleeve 21, and the sheet member 24. is suppressed.

The sealing portion 26 is formed substantially concentrically with the developing sleeve 21 toward the downstream in the rotational direction of the developing sleeve 21 from the position (regulating position) where the regulating blade 23 and the developing sleeve 21 are closest to each other with a slight gap from the developing sleeve 21 . be done. The gap (shortest distance) between the outer peripheral surface of the developing sleeve 21 and the outer peripheral surface of the sealing portion 26 is preferably 100 μm or more and 500 μm or less.

This is because when the gap between the outer peripheral surface of the developing sleeve 21 and the outer peripheral surface of the sealing portion 26 is smaller than 100 μm, the developing sleeve 21 and the sealing portion 26 may come into contact with each other depending on assembly accuracy and part tolerance. It's for. If the sealing portion 26 is brought into contact with the developing sleeve 21, the temperature of the contact portion between the developing sleeve 21 and the sealing portion 26 may rise.

On the other hand, when the gap between the outer peripheral surface of the developing sleeve 21 and the outer peripheral surface of the sealing portion 26 is larger than 500 μm, one longitudinal end portion of the space F partitioned by the developing sleeve 21, the regulating blade 23, and the sheet member 24 The portion covering each of the other ends is reduced. As a result, the effect of suppressing lateral movement of air in the developing container 20 from the central portion of the developing sleeve 21 toward the end portions thereof is reduced.

Therefore, the gap between the outer peripheral surface of the developing sleeve 21 and the outer peripheral surface of the sealing portion 26 is appropriately selected in consideration of assembly accuracy and part tolerance. In the first embodiment, the gap (shortest distance) between the outer peripheral surface of the developing sleeve 21 and the outer peripheral surface of the sealing portion 26 is set to about 200 μm in consideration of the component tolerance and mounting accuracy with respect to the developing sleeve 21 . . In addition, the facing surface side of the sheet member 24 is also formed substantially parallel to the sheet member 24 with a slight gap. From the viewpoint of toner scattering, it is preferable to provide these gaps so as to reduce them as much as possible in view of assembly and part tolerance.

In addition, in the first embodiment, as for the material of the pair of sealing portions 26, ABS, which is a general resin material, is selected in the first embodiment. A modification using a material may be used. When an elastic body such as a sponge is used for the pair of sealing portions 26, it is possible to use the pair of sealing portions 26 in contact with the developing sleeve 21. FIG. This is because when an elastic body such as a sponge is used for the pair of sealing portions 26, even if the developing sleeve 21 and the sealing portion 26 are in contact with each other, the contact portion between the developing sleeve 21 and the sealing portion 26 rises. This is because there is no risk of overheating.

When an elastic body such as a sponge is used for the pair of sealing portions 26, the gap between the outer peripheral surface of the developing sleeve 21 and the outer peripheral surface of the sealing portion 26 is substantially zero. The effect of covering the one end and the other end can be enhanced. If the effect of covering one end and the other end of the space F in the longitudinal direction is enhanced, lateral movement of air in the developing container 20 from the central portion toward the end portion of the developing sleeve 21 in the rotation axis direction is suppressed. Increased effect. However, since the developing sleeve 21 and the sealing portion 26 are brought into contact with each other, a configuration in which the developing sleeve 21 and the sealing portion 26 are not brought into contact with each other is preferable from the viewpoint of wear resistance (lifetime) of the elastic body. Needless to say, this is more preferable than the configuration in which the sealing portion 26 is brought into contact with the sealing portion 26 .

As shown in FIG. 6, the developing sleeve 21 and the regulating blade 23 extend over the entire region R of the developing sleeve 21 corresponding to the maximum image region among the image regions in which an image can be formed on the surface of the photosensitive drum 1 . and a space F partitioned by the sheet member 24 is formed. A pair of sealing portions 26 (a first sealing portion and a second sealing portion) are provided at one end portion and the other end portion in the longitudinal direction outside the region of the developing sleeve 21 having the developer conveying ability. are placed in each of the Thereby, the pair of sealing portions 26 can cover one end portion and the other end portion in the longitudinal direction of the space F partitioned by the developing sleeve 21 , the regulating blade 23 and the sheet member 24 .

Incidentally, the area where the developing sleeve 21 has the ability to convey the developer is the area R corresponding to the maximum image area among the image areas in which an image can be formed on the surface of the photosensitive drum 1 . Further, the region where the developing sleeve 21 has the ability to convey the developer means the region where the magnet 22 is provided inside the developing sleeve 21, and the surface processing (for example, , grooves, ditches, blasting, etc.).

Incidentally, when the sealing portion 26 is arranged in the area R corresponding to the maximum image area among the image areas in which an image can be formed on the surface of the photosensitive drum 1, the layer thickness of the developer carried on the developing sleeve 21 is (Coating amount) may change due to contact with the sealing portion 26, which may affect the electrostatic latent image. Therefore, in order to eliminate the influence on the electrostatic latent image, the pair of sealing portions 26 are not arranged in the region R where the developing sleeve 21 has the developer conveying ability, and the developing sleeve 21 is not provided with the developing agent conveying capability. It is arranged at each of one end portion and the other end portion on the outer side in the longitudinal direction of the region R having the agent transport capability.

As described above, in the first embodiment, in the developing device provided with the regulating blade 23 made of resin, the pair of sealing portions 26 are provided at the ends of the regulating blade 23 in the longitudinal direction. In the first embodiment, such a configuration can reduce the amount of toner that scatters outside the developing container 20 from the end of the developing sleeve 21 in the rotation axis direction.

[Second embodiment]
In the second embodiment, portions different from the first embodiment will be described, and other basic configurations are common to the first and second embodiments. In the configuration of the first embodiment described above, an example in which the pair of sealing portions 26 is fixed to the resin regulation blade 23 and the resin sheet attachment base 25 with double-sided tape or adhesive will be described. bottom. On the other hand, in the configuration of the second embodiment, a pair of sealing portion 26a and regulation blade 23a are formed of the same component. In other words, in the first embodiment, the regulating blade 23 and the pair of sealing portions 26 are separate bodies, whereas in the second embodiment, the regulating blade 23a and the pair of sealing portions 26a are integrated with resin. It is molded.

The regulating blade 23a is mounted by adjusting the gap (the shortest distance between the developing sleeve 21 and the regulating blade 23a) with high accuracy in order to obtain a developer layer with a predetermined layer thickness on the developing sleeve 21 . The adjustment accuracy of the gap between the developing sleeve 21 and the regulating blade 23a is ±20 to 50 μm.

In the second embodiment, similarly to the first embodiment, the regulating blade 23a is a resin regulating blade 23a molded from resin and has a rigidity that allows it to be bent. The regulating blade 23a is adhered to the developing container 20 with an adhesive while the regulating blade 23a is bent so that the gap (shortest distance) between the developing sleeve 21 and the regulating blade 23a is within a predetermined range. .

In the second embodiment, the regulating blade 23a and the pair of sealing portions 26a are integrally molded with resin. In the second embodiment, by attaching the regulating blade 23a to the developing container 20 so that the gap between the developing sleeve 21 and the regulating blade 23a is within a predetermined range, the pair of sealing portion 26a and the developing sleeve 21 are separated. can be assembled with high accuracy. In order to enhance the effect of suppressing lateral movement of the air in the developing container 20 from the central portion of the developing sleeve 21 in the rotation axis direction toward the end portions, the outer peripheral surface of the developing sleeve 21 and the outer peripheral surface of the sealing portion 26a It is preferable that the gap (shortest distance) between and is set to 100 μm to 500 μm.

In the second embodiment, since the regulating blade 23a and the pair of sealing portions 26a are integrally molded with resin, the pair of sealing portions 26a and the developing sleeve 21a can be assembled with high precision. Furthermore, in the second embodiment, the regulating blade 23a, the sheet attaching base 25a, and the pair of sealing portions 26a are integrally formed of resin. Therefore, in the second embodiment, compared to the first embodiment in which the regulating blade 23 and the pair of sealing portions 26 are separate bodies, the outer peripheral surface of the developing sleeve 21 and the sealing portion 26a are separated from each other. The gap (shortest distance) can be set small.

In the second embodiment, the gap (shortest distance) between the outer peripheral surface of the developing sleeve 21 and the outer peripheral surface of the sealing portion 26a is set to about 100 μm. The effect of suppressing the lateral movement of the air in the developing container 20 toward the part can be enhanced. Therefore, in the second embodiment, the effect of suppressing toner scattering from both ends of the developing sleeve 21 in the rotation axis direction can be enhanced.

In the configuration of the second embodiment (the regulation blade 23a and the pair of sealing portions 26a are integrated), the configuration of the first embodiment (the regulation blade 23 and the pair of sealing portions 26 are separate Certain configuration), the accuracy of the gap between the developing sleeve 21 and the pair of sealing portions 26a can be improved. In this respect, the second embodiment is more advantageous than the first embodiment.

On the other hand, in the configuration of the second embodiment in which the resin regulation blade 23a and the pair of sealing portions 26a are integrally molded, it is necessary to suppress sink marks and the like in relation to the thickness of the pair of sealing portions 26a. Therefore, in the second embodiment, the thickness of the pair of sealing portions 26a may be set in the vicinity of the basic thickness of the regulating blade 23a in the form of a rib in order to suppress sink marks or the like, or may be provided with an appropriate cutout. desirable.

(Other embodiments)
The present invention is not limited to the above embodiments, and various modifications (including organic combinations of each embodiment) are possible based on the gist of the present invention, and they are excluded from the scope of the present invention. isn't it.

In the above embodiment, as shown in FIG. 1, the image forming apparatus using the intermediate transfer belt 61 has been described as an example, but the present invention is not limited to this. It is also possible to apply the present invention to an image forming apparatus having a structure in which the transfer material S is brought into direct contact with the photosensitive drum 1 in order for transfer.

Reference Signs List 1 photoreceptor drum 2 developing device 20 developing container 21 developing sleeve 22 developing sleeve 23 regulating blade 24 sheet member 26 sealing portion 60 image forming device 68 exposure device

Claims (4)

a rotatable image carrier on which an electrostatic image is formed;
an exposure device for exposing the image carrier to form an electrostatic image on the image carrier;
a developing container containing a developer containing toner and carrier; a developing rotary member carrying and conveying the developer for developing an electrostatic image formed on the image carrier; A developer regulating member made of resin that is arranged to face the developing rotator and regulates the amount of developer carried on the developing rotator, and a developer regulating member on the developing rotator that is closest to the developer regulating member. downstream of the position on the developing rotor in the rotational direction and upstream of the position on the developing rotor where the developing rotor is closest to the image bearing member in the rotational direction of the developing rotor. a developing device having a sheet member disposed facing the developer regulating member and provided on the developer regulating member;
with
a position on the developing rotary member at which the developing rotary member is closest to the developer regulating member is lower than a position on the developing rotary member at which the developing rotary member is closest to the image bearing member;
The sheet member is provided over the entire area of the developing rotary member corresponding to the maximum image area in which an image can be formed on the image carrier,
A space partitioned by the developing rotator, the developer regulating member, and the sheet member is formed over the entire area of the developing rotator corresponding to the maximum image area,
A position facing one end of the development rotor in the rotation axis direction of the development rotor outside the area corresponding to the maximum image area in the rotation axis direction of the development rotor. is provided with a first sealing portion, and a second sealing portion is provided at a position facing the other end portion in the rotation axis direction of the developing rotor,
The first sealing portion covers one end in the longitudinal direction of the space outside the area of the developing rotator corresponding to the maximum image area in the rotation axis direction of the developing rotator, and The image forming apparatus, wherein the second sealing portion covers the other longitudinal end portion of the space. The image forming apparatus according to claim 1, wherein the developer regulating member, the first sealing portion, and the second sealing portion are integrally molded. The shortest distance between the developing rotor and the first sealing portion is 100 μm or more and 500 μm or less, and the shortest distance between the developing rotor and the second sealing portion is 100 μm or more and 500 μm or less. The image forming apparatus according to claim 1 or 2, characterized by comprising: The image forming apparatus according to any one of claims 1 to 3, wherein the developer regulating member has a rigidity that allows it to bend.

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