JP2009244524A - Developing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device capable of allowing the charge amount of a toner in a developing chamber to be uniform, and an image forming apparatus. <P>SOLUTION: The developing device includes: a developer carrier 52Y which carries the toner; a toner supply member 53Y which supplies the toner to the developer carrier 52Y; a regulation member 54Y which regulates an amount of the toner on the developer carrier 52Y; a developing chamber 51Y which has the developer carrier 52Y and the toner supply member 53Y; a transport section 55Y which is connected to an upper portion and a lower portion of the developing chamber 51Y and transports the toner from the lower portion to the upper portion outside the developing chamber 51Y; transport means 56Y, 57Y and 58Y which are disposed in the transport section 55Y and transport the toner while agitating the toner; and a toner giving section 60Y which is connected to the transport section 55Y and gives the toner to the transport section 55Y. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a developing device and an image forming apparatus that develop an electrostatic latent image on a latent image carrier with a developer.

An electrophotographic recording type image forming apparatus that exposes and forms an electrostatic latent image based on image data on the surface of a latent image carrier is known. In this image forming apparatus, the electrostatic latent image is developed with toner by a developing device. Then, the toner image on the surface of the latent image carrier is transferred to a recording medium such as recording paper to form an image. In recent years, this type of image forming apparatus is generally designed to be detachably mounted with a toner cartridge that is constructed integrally with or separately from a developing device and that contains toner. By repeatedly developing the electrostatic latent image, when the stored toner is consumed, the toner cartridge is replaced to replenish the toner for developing the electrostatic latent image on the surface of the latent image carrier. ing.

In such a developing device, the toner in the developing chamber is agitated for a long time by the agitating member, the toner supply roller, and the regulating blade, so that the charging ability is deteriorated. When the new toner and the deteriorated toner remaining in the developing chamber are stirred and mixed by replacing the toner cartridge, the new toner having high charging ability is selectively charged, and the deteriorated toner becomes insufficiently charged. When the entire charge amount becomes insufficient, regulation passing leakage and adhesion (fogging) to non-image portions occur. In order to prevent this, Japanese Patent Laid-Open No. 2000-181216 discloses the driving time of the developing device, and forcibly writing in the non-image portion according to the driving time,
A processing technique for residual toner remaining in the developing chamber that consumes toner having deteriorated charging ability in the developing chamber is disclosed.
JP 2000-181216 A

However, in the conventional technology of the related art, toners having different deterioration states (chargeability) are mixed in the developing chamber, and toners having different charge amounts are mixed, so that regulation leakage or fogging may occur.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art and provide a developing device and an image forming apparatus that make the charge amount of toner in the developing chamber close to uniform.

The developing device of the present invention includes a developer carrying member that carries toner, a toner supply member that supplies toner to the developer carrying member, a regulating member that regulates the amount of toner on the developer carrying member, and the development A developer chamber having an agent carrier and the toner supply member; a transport unit connected to an upper part and a lower part of the developer chamber; and transporting toner from a lower part to an upper part of the developer chamber; Since it has a conveying means for conveying while stirring, and a toner replenishing unit connected to the conveying unit for replenishing toner to the conveying unit, before the toner is replenished to the developing chamber, different charges are applied in the conveying unit. The toner held therein can be agitated, and the charge amount of the toner in the developing chamber can be made nearly uniform.

The transport unit is connected to a lower portion of the developing chamber, and a lower transport path for collecting toner;
A lifting conveyance path that is connected to the lower conveyance path and conveys toner from the lower part to the upper part outside the developing chamber, and an upper conveyance path that connects the lifting conveyance path and the upper part of the developing chamber and conveys toner to the developing chamber. Since the toner replenishing unit is connected to the lower conveyance path, the toner agitation portion increases in the conveyance unit, and the toner charge amount in the developing chamber can be made more uniform. It becomes.

Further, since the upper transport path is connected to the upper portion of the developing chamber at the central portion in the axial direction of the developer carrier, it is possible to supply toner smoothly and uniformly into the developing chamber.

The lower conveying path has a lower conveying means, and the toner replenishing portion is connected to the upstream side of the lower conveying path in the conveying direction of the lower conveying means. Therefore, the toner charge amount in the developing chamber can be made more uniform.

The toner replenishing section includes a toner cartridge, a toner replenishing path that connects the toner cartridge and the transport section, and a toner replenishing member that transports toner in the toner replenishing path, and the toner replenishing section. Since the member and the lower conveying means are the same member, it is possible to drive both the toner replenishing member and the lower conveying means with one driving means,
The number of parts and energy can be reduced.

The toner replenishing section includes a toner cartridge, a toner replenishing path that connects the toner cartridge and the transport section, and a toner replenishing member that transports toner in the toner replenishing path, and the toner replenishing section. Since the member and the lower conveying means are separate members, the degree of freedom in design increases.

Further, since the toner replenishment path is arranged in a direction intersecting with the conveying direction of the lower conveying means, the space in the axial direction of the developer carrying member can be effectively utilized, and the degree of freedom in design is further increased.

Furthermore, the image forming apparatus of the present invention includes a latent image carrier on which an electrostatic latent image is formed, and a developing device that develops the electrostatic latent image with a developer to form a toner image on the latent image carrier. And at least a transfer device that transfers a toner image on the latent image carrier to a transfer material, and a fixing device that fixes the toner image on the transfer material. Since the developing device described in any one of 7 is mounted, an image with good image quality can be formed with a nearly uniform charge amount.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a view showing an embodiment of an image forming apparatus provided with the developing device of the present invention, and FIG. 2 is an enlarged view of the yellow image forming station of FIG.

As shown in FIG. 1, the image forming apparatus 10 includes four image forming stations 15 (Y, M,
C, K), an intermediate transfer belt 70, a secondary transfer unit 80, and a fixing unit 9
0, a display unit 95 which is a means for notifying a user and is formed of a liquid crystal panel, and a control unit 100 which controls these units and operates as an image forming apparatus.

The image forming station 15 (Y, M, C, K) has a function of forming an image with toners of yellow (Y), magenta (M), cyan (C), and black (K), respectively.
Since the configuration of the image forming station 15 (Y, M, C, K) is the same, the image forming station 15Y will be described below.

As shown in FIG. 2, the image forming station 15Y includes a photosensitive member 2 as an example of an image carrier.
A charging unit 30Y, an exposure unit 40Y, a developing cartridge 50Y as a developing device, a primary transfer portion B1, and a photosensitive member cleaning unit 75Y are provided along the 0Y rotation direction.

The photoreceptor 20Y has a cylindrical base material and a photosensitive layer formed on the outer peripheral surface thereof, and can rotate around a central axis. In the present embodiment, the photoreceptor 20Y rotates clockwise as indicated by an arrow. To do.

The charging unit 30Y is a device for charging the photoconductor 20Y. Exposure unit 40
From Y, a latent image is formed on the charged photoreceptor 20Y by laser irradiation.

The exposure unit 40Y has a semiconductor laser, a polygon mirror, an F-θ lens, and the like, and is charged with a modulated laser based on an image signal input from a host computer (not shown) such as a personal computer or a word processor. Irradiate onto the photoconductor 20Y.

The developing cartridge 50Y is a device for developing the latent image formed on the photoconductor 20Y using yellow (Y) toner. In the developing cartridge 50Y, a developing roller 52Y and a toner supply roller 53Y are disposed in a developing chamber 51Y to which new toner is supplied from a replaceable toner cartridge 56Y, and a regulating blade 54Y comes into contact with the developing roller 52Y and the developing roller 52Y. Thin the upper toner.

The primary transfer portion B1 transfers the yellow toner image formed on the photoreceptor 20Y to the intermediate transfer belt 70.
It is a place to transcribe to. When the four color toners are sequentially transferred in the primary transfer portions B 1, B 2, B 3 and B 4, a full color toner image is formed on the intermediate transfer belt 70.

The intermediate transfer belt 70 is an endless belt stretched around a belt driving roller 71a and a driven roller 71b, and is rotationally driven while being in contact with the photoreceptor 20 (Y, M, C, K).

The secondary transfer unit 80 is a device for transferring a single color toner image or a full color toner image formed on the intermediate transfer belt 70 onto a transfer material such as paper, film, or cloth.

The fixing unit 90 includes a fixing roller 90a and a pressure roller 90b, and is a device for fusing a single color toner image or a full color toner image transferred onto a transfer material to the transfer material to form a permanent image.

The photoconductor cleaning unit 75Y includes a rubber photoconductor cleaning blade 76Y that is in contact with the surface of the photoconductor 20Y. After the toner image is transferred onto the intermediate transfer belt 70 at the primary transfer portion B1, the photoconductor is cleaned. The toner remaining on 20Y is removed from the photoconductor cleaning blade 7
It is an apparatus for scraping and removing with 6Y.

  Next, the operation of the image forming apparatus 10 configured as described above will be described.

First, when an image signal and a control signal from a host computer (not shown) are input to the main controller of the image forming apparatus via an interface, the photoconductor 20Y and the developing cartridge are controlled by a unit controller based on a command from the main controller. 50
The developing roller 52Y, the supply roller 53Y, the intermediate transfer belt 70, and the like provided in Y rotate. The photoconductor 20Y is sequentially charged by the charging unit 30Y at the charging position while rotating.

The charged area of the photoconductor 20Y reaches the exposure position as the photoconductor 20Y rotates, and a latent image corresponding to yellow Y image information is formed in the area by the exposure unit 40Y.

The latent image formed on the photoconductor 20Y reaches the development position as the photoconductor 20Y rotates, and is developed by the developing cartridge 50Y. Thereby, a toner image is formed on the photoreceptor 20Y.

The toner image formed on the photoreceptor 20Y is transferred to the primary transfer portion B1 as the photoreceptor 20Y rotates.
At this position, the image is transferred to the intermediate transfer belt 70 by the primary transfer unit. At this time, a primary transfer voltage having a polarity opposite to the charging polarity of the toner is applied to the primary transfer unit. As a result, the four color toner images formed on the respective photoconductors 20 (Y, M, C, K) are transferred to overlap the intermediate transfer belt 70, and a full color toner image is formed on the intermediate transfer belt 70. Is done.

The intermediate transfer belt 70 is driven by a belt driving roller 7 from a belt driving means such as a motor.
It is driven by being transmitted through 1a.

The full color toner image formed on the intermediate transfer belt 70 is transferred to a transfer material such as paper by the secondary transfer unit 80. Such a transfer material is fed from the paper feed tray to the paper feed roller 94.
a, conveyed to the secondary transfer unit 80 via the registration roller 94b.

The full color liquid developer image transferred to the transfer material is heated and pressed by the fixing unit 90 and fused to the transfer material. After passing through the fixing unit 90, the paper is discharged by a paper discharge roller 94c.

On the other hand, the photoreceptor 20 (Y, M, C, K) is neutralized by a neutralization unit (not shown) after passing through the primary transfer portions B1, B2, B3, B4, and further, the photoreceptor cleaning unit 75 ( Photoconductor cleaning blade 76 (Y, M, Y) supported by Y, M, C, K)
C, K) causes the toner adhering to the surface to be scraped off to prepare for charging to form the next latent image. The toner scraped off is removed from the photosensitive member cleaning unit 75 (Y,
M, C, and K) are collected by a residual toner collecting unit.

An intermediate transfer belt cleaning device (not shown) is installed on the driven roller 71b side of the intermediate transfer belt 70 after the secondary transfer, and cleans the intermediate transfer belt 70 after the secondary transfer. Although the description has been given based on the embodiment of the intermediate transfer system using the intermediate transfer belt, a direct transfer image forming apparatus may be used.

In the developing cartridge 50Y, after long-time development driving is performed, toners in the developing chamber 51Y are mixed with toners having different deterioration states (such as chargeability).

As the toner deterioration, for example, the external fluid additive such as hydrophobic silica added to the toner is gradually embedded in or released from the toner due to mechanical stress applied to the toner. Since the toner particle size is increased by crushing the toner, or the toner charge amount at the time of development is proportional to the particle size of the toner, the development is selectively performed according to the particle size of the toner. Accumulation of small-diameter toners, further decrease in fluidity due to the small-diameter toners, and generation of aggregates due to aggregation of the toners with decreased fluidity, which are causes of image degradation It becomes.

Small toner particles tend to have an excessively large charge amount and have a strong mirror image force on the latent image carrier, so that they are observed as non-image areas (so-called image fogging) in images. Is done. In addition, the toner having a small particle diameter is easily scattered and is scattered from the opening of the developing device and causes internal contamination of the image forming apparatus.

Further, when the fluidity of the toner is lowered, the toner is insufficiently frictionally charged in the developing device, and a toner having a polarity opposite to a desired charging polarity is generated. This reverse polarity toner is still observed as image fog.

In addition, the toner with reduced fluidity and the aggregates thereof cannot smoothly pass through the contact portion between the developing roller 52Y and the regulating blade 54Y, so that the charge is insufficient and the image is fogged. . Further, the agglomerates are caused by the mechanical force and frictional heat at the contact portion between the developing roller 52Y and the regulating blade 54Y, so that the developing roller 52Y or the regulating blade 54Y.
If the toner is fused (so-called filming) to the surface of the toner, or if the agglomerates are extremely large, the contact portions are clogged as they are. As a result, a toner layer is not formed on the developing roller 52Y at the contact portion where filming or the like has occurred, and an image corresponding to the toner layer is observed as a white stripe (image missing).

FIG. 3 is a perspective view showing a first embodiment of the developing cartridge 50Y according to the present invention, and FIG. 4 is a cross-sectional view in a direction perpendicular to the axial direction of the developing cartridge 50Y of FIG.

As shown in FIGS. 3 and 4, the developing cartridge 50Y according to the first embodiment includes a developing chamber 51Y and a transport unit 55Y. The developing chamber 51Y and the transport unit 55Y include a developing roller 52Y and a toner supply roller 53Y. Is defined as a boundary line V, a space from the developing chamber inlet 51aY to the boundary line V is defined as a developing chamber 51Y, a space 55aY below the boundary line V, a lower conveying path 55bY, and a lifting conveying path. 55cY and the upper conveyance path 55dY are defined as a conveyance unit 55Y.
In addition, a toner replenishing unit 60Y that replenishes the developing cartridge 50Y with new toner is provided.

The developing chamber 51Y includes a developing roller 52Y and a toner supply roller 53Y. The toner supply roller 53Y supplies toner to the developing roller 52Y, and may rotate in either direction. The developing roller 52Y rotates counterclockwise and is supplied with toner from the toner supply roller 53Y. The regulating blade 54Y is disposed below the developing roller 52Y and regulates the amount of toner on the developing roller 52Y.

The transport unit 55Y includes a space 55aY below the boundary line V, a lower transport path 55bY, a lift transport path 55cY, and an upper transport path 55dY. The lower transport path 55bY, the lift transport path 55cY, and the upper transport path 55dY have a lower transport member 56Y as a lower transport means, a lift transport member 57Y as a lift transport means, and an upper transport member 58Y as an upper transport means, respectively. . In FIG. 3, a part of each conveying member is exposed for explanation.

The space 55aY below the boundary line V is a portion where toner that has passed through the nip portion between the developing roller 52Y and the toner supply roller 53Y falls into the lower conveyance path 55bY.

The lower conveying member 56Y is located below the developing cartridge 50Y, in particular, the toner supply roller 53.
The toner is arranged below Y, collects the toner dropped from the developing chamber 50Y, and is stirred while being conveyed in the first axial direction, and is constituted by a screw conveyor or the like.

The lifting and conveying member 57Y stirs the toner conveyed by the lower conveying member 56Y outside the developing chamber 51Y while conveying the toner above the developing cartridge 50Y and in a direction perpendicular to the first direction, and is composed of a screw or the like. Is done.

The upper transport member 58Y moves the toner transported upward by the lift transport member 57Y to the developing chamber inlet 51aY at the substantially central portion in the axial direction, and stirs while transporting in the first axial direction. Consists of a screw conveyor and the like.

The toner supply unit 60Y includes a toner cartridge 61Y, a toner supply member 62Y, and a toner supply path 63Y. In addition, the toner replenishing unit 60Y is provided on the lower conveyance path 55b of the conveyance unit 55Y.
Connected to the upstream side of the lower conveyance member 56Y in Y in the conveyance direction, and supplies toner to the conveyance unit 55Y.

The toner cartridge 61Y is filled with new toner and is configured to be detachable from the toner supply member 62Y and the toner supply path 63Y. The toner replenishment path 63Y connects the toner cartridge 61Y and the transport portion 55Y of the developing cartridge 50Y, and has a toner replenishment member 62Y inside. The toner replenishing member 62Y is agitated while conveying the toner in the first axial direction, and is constituted by a screw conveyor or the like. In the present embodiment, the toner supply member 62Y and the lower transport member 56Y are the same member.

The transport members 56Y, 57Y, and 58Y are driven by a driving unit (not shown).
One drive unit may drive each of the transport members 56Y, 57Y, and 58Y, or a plurality of drive units may be provided corresponding to each of the transport members 56Y, 57Y, and 58Y.

Further, the regulating blade 54Y is arranged above or below the developing roller 52Y and regulates the amount of toner carried on the developing roller 52Y. When the regulating blade 54Y is provided below the developing roller 52Y so as to come into contact with the developing roller 52Y in the counter direction with respect to the rotation direction of the developing roller 52Y, the toner passing through the nip portion between the developing roller 52Y and the toner supply roller 53Y is further conveyed to the lower part. It becomes easy to fall to the path 55bY.

FIG. 5 is a schematic diagram showing the flow of toner. The new toner in the toner cartridge 61Y is agitated while being conveyed in the first axial direction by the toner replenishing member 62Y in the toner replenishing path 63Y, and is conveyed into the conveying portion 55Y of the developing cartridge 50Y.

In the transport section 55Y, new toner is mixed with the toner collected by passing through the developing roller 52Y, the toner supply roller 53Y, the regulating blade 54Y, etc., and passes through the lower transport member 56Y, the lift transport member 57, and the upper transport member 58Y. Then, it is again put into the developing chamber 51Y. In this way, the collected toner and new toner are mixed and agitated, so that the charge is made uniform. The longer the distance in which the collected toner and the new toner are mixed and agitated, the more uniform the charging is. Therefore, the toner replenishment path 62Y has a space 55a below the boundary line V.
It is preferable to be connected to Y or the lower conveyance path 55bY.

FIG. 6 is a plan view showing a second embodiment of the developing cartridge 50Y according to the present invention, and FIG. 7 is a sectional view in a direction perpendicular to the axial direction of the developing cartridge 50Y of FIG.

As shown in FIGS. 6 and 7, the developing cartridge 50Y of the second embodiment has a developing chamber 51Y and a transport section 55Y similar to those of the first embodiment, but the connection position of the replenishing section 60 is different. .

The toner supply unit 60Y of the second embodiment includes a toner cartridge 61Y and a toner supply member 62.
Y and toner supply path 63Y. Further, the toner replenishing unit 60Y is arranged in a direction intersecting the conveyance direction at a substantially center of the lower conveyance member 56Y in the lower conveyance path 55bY of the conveyance unit 55Y, and replenishes toner to the conveyance unit 55Y.

The toner cartridge 61Y is filled with new toner and is configured to be detachable from the toner supply member 62Y and the toner supply path 63Y. The toner replenishment path 62Y is a space 55aY below the boundary line V between the conveying portion 55Y of the toner cartridge 61Y and the developing cartridge 50Y.
And a lower conveyance path 55bY, and has a toner supply member 62Y therein. The toner replenishing member 62Y stirs the toner while conveying the toner in a second direction perpendicular to the axial direction, and includes a screw conveyor or the like. In this embodiment, the toner replenishing member 62Y and the lower conveying member 56Y are separate members.

Since the toner replenishing member 62Y of the second embodiment is configured to convey the toner in the second direction perpendicular to the axial direction, it can be used when there is insufficient space in the axial direction.

As described above, the developing device of the present embodiment regulates the developer carrier 52Y that carries toner, the toner supply member 53Y that supplies toner to the developer carrier 52Y, and the toner amount on the developer carrier 52Y. A regulating member 54Y, a developing chamber 51Y having a developer carrier 52Y and a toner supply member 53Y, a transport unit 55Y connected to the upper and lower portions of the developing chamber 51Y and transporting toner from the lower portion to the upper portion of the developing chamber 51Y. And transport means 56Y, 57Y, 58Y that are disposed in the transport section 55Y and transport the toner while stirring, and a toner replenishment section 60Y that is connected to the transport section 55Y and replenishes toner to the transport section 55Y. Before the toner is supplied to the developing chamber 51Y, the toner having a different charge can be agitated in the transport portion 55Y.
It is possible to make the charge amount of the toner close to uniform.

The transport section 55Y is connected to the lower part of the developing chamber 51Y, and is connected to the lower transport path 55bY for collecting the toner and the lower transport path 55bY, and the lifting transport path for transporting the toner from the lower part to the upper part outside the developing chamber 51Y. 55cY, and an upper conveyance path 55dY that connects the lifting conveyance path 55cY and the upper portion of the developing chamber 51Y and conveys toner to the developing chamber 51Y. The toner replenishing section 60Y is connected to the lower conveyance path 55bY. Therefore, the portion where the toner is agitated in the transport portion 55Y increases, and the charge amount of the toner in the developing chamber 51Y can be made more uniform.

The upper conveyance path 55dY is a substantially central portion in the developer carrier 52Y axial direction, and is in the developing chamber 5.
Since it is connected to the upper part of 1Y, it becomes possible to supply toner smoothly and uniformly into the developing chamber 51Y.

Further, the lower conveyance path 55bY has a lower conveyance means 56Y, and the toner replenishing section 60Y is connected to the upstream side of the lower conveyance path 55bY in the conveyance direction of the lower conveyance means 56Y, so the toner is agitated by the conveyance section 55Y. As a result, the amount of toner charged in the developing chamber 51Y can be made more uniform.

The toner replenishing unit 60Y includes a toner cartridge 61Y and a toner cartridge 61.
A toner replenishment path 62Y that connects Y and the conveyance section 55Y, and a toner replenishment member 63Y that conveys toner in the toner replenishment path 62Y. The toner replenishment member 63Y and the lower conveyance means 56Y
Are the same member, the toner replenishing member 63Y and the lower transporting unit 56Y are formed by one driving unit.
Both of them can be driven, and the number of parts and energy can be reduced.

The toner replenishing unit 60Y includes a toner cartridge 61Y and a toner cartridge 61.
A toner replenishment path 62Y that connects Y and the conveyance section 55Y, and a toner replenishment member 63Y that conveys toner in the toner replenishment path 62Y. The toner replenishment member 63Y and the lower conveyance means 56Y
Since this is a separate member, the degree of freedom in design increases.

Further, since the toner replenishment path 60Y is arranged in a direction intersecting with the conveyance direction of the lower conveyance means 56Y, the axial space of the developer carrier 20Y can be used effectively, and the degree of freedom in design is further increased.

Further, the image forming apparatus according to the present embodiment includes a photosensitive member 20Y on which an electrostatic latent image is formed, a developing device that develops the electrostatic latent image with a developer to form a toner image on the photosensitive member 20Y, and a photosensitive member. Since at least the transfer device 80 for transferring the toner image on the body 20Y to the transfer material and the fixing device 90 for fixing the toner image on the transfer material are provided and the developing device is mounted, the image quality can be obtained with a nearly uniform charge amount. A good image can be formed.

1 is a diagram illustrating an image forming apparatus according to an exemplary embodiment. FIG. 3 is a cross-sectional view showing the main components of the periphery of the photoreceptor and the developing cartridge. 1 is a perspective view showing a first embodiment of a developing cartridge according to the present invention. FIG. 4 is a cross-sectional view in a direction perpendicular to the axial direction of the developing cartridge of FIG. 3. FIG. 3 is a schematic diagram illustrating a toner flow. FIG. 6 is a plan view showing a second embodiment of the developing cartridge according to the present invention. FIG. 7 is a cross-sectional view in a direction perpendicular to the axial direction of the developing cartridge of FIG. 6.

Explanation of symbols

10Y, 10M, 10C, 10K ... Image forming apparatus, 15Y, 15M, 15C, 15K ...
Image forming station, 20Y, 20M, 20C, 20K ... photosensitive member (latent image carrier), 30
Y, 30M, 30C, 30K ... charger, 40Y, 40M, 40C, 40K ... exposure unit, 50Y, 50M, 50C, 50K ... developing cartridge (developing device), 51Y, 51M,
51C, 51K ... developing chamber, 52Y, 52M, 52C, 52K ... developing roller (developer carrier), 53Y, 53M, 53C, 53K ... toner supply roller (toner supply member), 54Y,
54M, 54C, 54K ... regulating blade, 55Y, 55M, 55C, 55K ... conveying section, 5
6Y, 56M, 56C, 56K ... Lower conveying member, 57Y, 57M, 57C, 57K ... Lift conveying member, 58Y, 58M, 58C, 58K ... Upper conveying member, 70 ... Intermediate transfer belt (intermediate transfer member), 75Y, 75M , 75C, 75K ... Photoconductor cleaning unit (latent image carrier cleaning unit), 80 ... Secondary transfer unit, 90 ... Fixing unit

Claims (8)

A developer carrier for carrying toner;
A toner supply member for supplying toner to the developer carrier;
A regulating member for regulating the amount of toner on the developer carrying member;
A developing chamber having the developer carrier and the toner supply member;
A transport unit that is connected to the upper and lower portions of the developing chamber and transports toner from the lower portion to the upper portion of the developing chamber;
A conveying means disposed in the conveying section for conveying the toner while stirring;
A toner replenishing unit connected to the conveying unit for replenishing toner to the conveying unit;
A developing device comprising: The transport unit is
A lower conveyance path connected to a lower portion of the developing chamber and collecting toner;
A lifting conveyance path that is connected to the lower conveyance path and conveys toner from the lower part to the upper part outside the developing chamber;
An upper conveyance path that connects the lifting conveyance path and the upper part of the developing chamber, and conveys toner to the developing chamber;
Have
The developing device according to claim 1, wherein the toner replenishing unit is connected to the lower conveyance path. The developing device according to claim 2, wherein the upper transport path is connected to an upper portion of the developing chamber at a central portion in the axial direction of the developer carrier. The lower transport path has a lower transport means,
4. The developing device according to claim 2, wherein the toner replenishing unit is connected to an upstream side in a transport direction of the lower transport unit in the lower transport path. The toner replenishing unit
A toner cartridge,
A toner supply path connecting the toner cartridge and the transport unit;
A toner replenishing member for conveying toner in the toner replenishing path;
Have
The developing device according to claim 4, wherein the toner replenishing member and the lower conveying unit are the same member. The toner replenishing unit
A toner cartridge,
A toner supply path connecting the toner cartridge and the transport unit;
A toner replenishing member for conveying toner in the toner replenishing path;
Have
The developing device according to claim 4, wherein the toner replenishing member and the lower conveyance unit are separate members. The developing device according to claim 6, wherein the toner replenishment path is arranged in a direction intersecting a transport direction of the lower transport unit. A latent image carrier on which an electrostatic latent image is formed;
A developing device for developing the electrostatic latent image with a developer to form a toner image on the latent image carrier;
A transfer device for transferring the toner image on the latent image carrier to a transfer material;
A fixing device for fixing a toner image on a transfer material;
Comprising at least
An image forming apparatus comprising the developing device according to claim 1 as the developing device.

Images