JP2002189346A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device by which a latent image on an image carrier can be stably developed with toner by having an excellent quality by suppressing the occurrence of a defective image due to deteriorated toner by enhancing the recovery efficiency of the deteriorated toner to a toner storing part storing fresh toner. SOLUTION: A regulating rear space SP is made to communicate with the toner storing part 45 by the bottom part 412 of a housing member 41 and a partition 411, and also a valve member 49 is provided on a communicating path R, so that toner flow-out to the toner storing part 45 from the regulating rear space SP is attained and on the other hand, toner flow-in from the toner storing part 45 to the regulating rear space SP is regulated. Thus, the deteriorated toner caused during development processing is captured by the regulating rear space SP, and a rotary developing unit 4 is rotated for the changeover of a developing unit after the development processing, so that the deteriorated toner is surely recovered to the toner storing part 45.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, a copying machine, a facsimile machine, and the like for visualizing an electrostatic latent image formed on an image carrier such as a photosensitive drum or a photosensitive belt by attaching toner to the latent image. And a developing device used in the electrophotographic image forming apparatus.

[0002]

2. Description of the Related Art As a developing device of this type, there is a one-component developing system using one-component toner. For example, Japanese Patent Application Laid-Open No. 7-44011 discloses that a thin layer of non-magnetic toner is formed on the surface of a developing roller (developing sleeve) and is brought into contact with the surface of a photosensitive drum as an image carrier at a predetermined developing position. Discloses an apparatus for performing development. More specifically, the developing roller elastically contacts the photosensitive drum and has a nip width due to deformation, rotates in a direction opposite to the rotating direction of the photosensitive drum, and faces the image carrier. The toner is conveyed to the developing position. A supply roller (toner supply body) is provided on the opposite side of the developing roller from the development position, and the non-magnetic one-component toner stored in the toner storage section provided in the developing device main body is removed. Supply to developing roller. Also,
A regulating blade is provided below the developing roller so that a tip of the regulating roller contacts the developing roller. The regulating blade regulates the amount of toner transported to the developing position by the developing roller. Form a thin layer. The toner thus formed is transported to the developing position to develop the latent image on the photosensitive drum.

[0003]

By the way, in the developing device constructed as described above, the non-magnetic one-component toner may be deteriorated by long-term use. For example, the toner on the developing roller may be rubbed by the supply roller or the regulating blade to break the toner. Further, when the toner and the external additive are rubbed at the contact position, there is a problem that the external additive is buried in the toner base particles and the external additive is detached from the toner. . Further, such deteriorated toner may cause a phenomenon called so-called filming, which remains as a film on the surface of the developing roller or the regulating blade. Due to such factors, density unevenness may occur, or an image with low granularity may be formed, resulting in image defects.

Here, in order to suppress the influence of the deteriorated toner, one of effective measures is to return the deteriorated toner to the toner storing section and mix the deteriorated toner with the fresh toner stored in the toner storing section. However, in the conventional apparatus, the recovery efficiency of the deteriorated toner in the toner storing section was not high. Further, in the conventional apparatus, a relatively large space is formed at a contact position where the regulating blade and the developing roller contact each other, and the deteriorated toner may stay in a powder state in this space. For this reason, the collection of the deteriorated toner in the toner storage unit does not progress, and it is difficult to improve the image defect caused by the deteriorated toner.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and enhances the efficiency of collecting deteriorated toner in a toner storage section in which fresh toner is stored, suppresses image defects due to the deteriorated toner, and reduces the latent image on the image carrier. It is an object of the present invention to provide a developing device capable of stably developing an image with high quality and toner.

[0006]

According to the present invention, a plurality of developing devices for developing a latent image formed on an image carrier with toner are provided, and the plurality of developing devices are rotatably provided. Developing device holding means for holding the developing device while being arranged along, and by rotating and positioning the developing device holding device, one of the plurality of developing devices is selectively disposed facing the image carrier. And a developing device for developing the latent image with toner by the developing device. To achieve the above object, each developing device is configured as follows. Each of the developing devices includes a toner storage unit that stores the toner, a toner carrier that conveys the toner to a development position facing the image carrier by rotating while carrying the toner, and a toner storage unit that rotates in the rotation direction of the toner carrier. The toner supply unit that supplies the toner in the toner storage unit to the toner carrier by rotating while being in contact with the toner carrier on the upstream side with respect to the development position, and the toner carrier and the toner supply unit communicate with each other. And a regulating unit that regulates excess toner at a contact position sandwiched between the developing position and the contact position to form a thin charged toner layer on the surface of the toner carrier. A communication path is formed from the post-regulation space facing the toner supply body and the regulation means to the toner storage unit, and the communication between the post-regulation space and the toner storage unit is established. And a toner flow control means provided on the communication path to allow toner flow from the post-regulation space to the toner storage section, and to regulate toner flow from the toner storage section to the post-regulation space. And

In the developing device configured as described above, the post-regulation space facing the toner carrier, the toner supply body, and the regulation means is communicated with the toner storage section through a communication path. In addition, a toner flow control unit is provided on the communication path to enable toner flow from the regulated space to the toner storage unit, while restricting toner flow from the toner storage unit to the regulated space. . For this reason, one developing unit is selectively disposed opposite to the image carrier, and while the developing unit performs the toner development of the latent image, the flow of the fresh toner from the toner storage unit into the post-regulation space is restricted. At the start of development by the developing device, the regulated space is empty. Then, as the developing process proceeds, only the toner generated at the contact position or the contact position due to the developing process, that is, only the deteriorated toner, is captured in the post-regulation space without the fresh toner flowing from the toner reservoir. To go. Then, the developing process by the developing device is completed,
As each developing device rotates, the degraded toner captured in the post-regulation space flows out of the post-regulation space into the toner storage unit via the toner flow control means due to the rotation, and the post-regulation space is again empty. Return to As described above, the deteriorated toner is captured by the post-regulation space, the developing process is completed, and the deteriorated toner is collected in the toner storage unit during the toner development by another developing device.

Here, the toner flow control means is supported at one end thereof so as to be swingable with respect to the communication means, and the other end is capable of contacting the outer peripheral surface of the toner supply member. May be configured. Further, the valve member is desirably disposed as follows according to the rotation direction of the toner supply member in order to effectively prevent the toner from flowing into the post-regulation space from the toner storage section.

First, when the toner supply member rotates in the direction opposite to the rotation direction of the toner carrier, the valve member is moved such that one end thereof is located upstream of the other end in the rotation direction of the toner supply member. It is desirable to arrange them so that they are located. On the other hand, when the toner supply member rotates in the same direction as the rotation direction of the toner carrier, the valve member is moved so that one end thereof is located downstream of the other end in the rotation direction of the toner supply member. It is desirable to arrange.

When the regulating means is disposed below the contact position in the vertical direction, one end of the valve member is connected to the communicating means below the imaginary horizontal line passing through the rotation center of the toner supply body. When swingably supported, the area of the peripheral surface of the toner supply body that rubs against the fresh toner in the toner storage unit increases. By increasing the rubbing area in this manner, the amount of preliminary charge given to the toner before reaching the contact position increases, and the toner can be charged more reliably.

Further, the regulating means has a rear end fixed below the contact position in the vertical direction, and the leading end elastically contacts the surface of the toner carrier at the contact position. It is preferable that the front end is disposed upstream of the rear end in the rotation direction of the toner carrier. In this case, the regulating means comes into contact with the peripheral surface of the toner carrier at an obtuse angle, and the toner scraped from the toner carrier by the regulating means, that is, the deteriorated toner can be guided to the post-regulation space, The toner collection efficiency can be improved.

[0012]

FIG. 1 is a view showing an image forming apparatus equipped with an embodiment of a developing device according to the present invention. In this image forming apparatus, a photoreceptor 2 is provided in an apparatus main body 1 so as to be rotatable in an arrow direction D1 in FIG. Further, around the photosensitive member 2 along the rotation direction D1,
A charger 3 as a charging unit, a rotary developing unit 4 as a developing unit, and a cleaning unit 5 are arranged. The charger 3 is applied with a charging bias from a charging bias circuit (not shown), and uniformly charges the outer peripheral surface of the photoconductor 2.

Then, a laser beam L is emitted from the exposure unit 6 toward the outer peripheral surface of the photosensitive member 2 charged by the charger 3. The exposure unit 6 performs laser beam L irradiation according to image data obtained by developing an image forming command into an image.
On the photoreceptor 2 to form an electrostatic latent image on the photoreceptor 2 corresponding to the image forming command.

The electrostatic latent image thus formed is developed by the developing unit 4 with toner. That is, in this embodiment, the developing unit 4 is a developing unit 4 for yellow.
A developing unit 4C for Y and cyan, a developing unit 4M for magenta,
And a developing device 4K for black is provided rotatably about the axis. These developing units 4Y, 4C, 4M, 4K
Is rotated and positioned, and selectively contacts the photoconductor 2 to apply toner to the surface of the photoconductor 2. As a result, the electrostatic latent image on the photoconductor 2 is visualized in the selected toner color. The configuration and operation of the developing unit 4 will be described later in detail.

The toner image developed by the developing unit 4 as described above is transferred to the transfer unit 7 in the primary transfer area TR1.
Is primarily transferred onto the intermediate transfer belt 71. A cleaning unit 5 is disposed at a position in the circumferential direction (rotational direction D1 in FIG. 1) from the primary transfer area TR1 to remove toner remaining on the outer peripheral surface of the photoconductor 2 after the primary transfer. Scrape off.

The transfer unit 7 includes an intermediate transfer belt 71 stretched over a plurality of rollers, and a drive unit (not shown) for driving the intermediate transfer belt 71 to rotate. When the color image is to be transferred to the sheet member S, the color images are formed by superimposing the toner images of each color formed on the photoconductor 2 on the intermediate transfer belt 71,
In a predetermined secondary transfer area TR2, a color image is secondarily transferred onto the sheet member S taken out of the cassette 8. The sheet member S on which the color image has been formed is conveyed via the fixing unit 9 to the discharge tray section 11 provided on the upper surface of the apparatus main body 1.

Next, the structure and operation of the rotary developing unit 4 provided in the image forming apparatus of FIG. 1 will be described in detail. FIG. 2 is a view showing a rotary developing unit as an embodiment of the developing device according to the present invention. FIG. 3 is a partially enlarged view of the developing device of FIG. As shown in FIG. 2, the rotary developing unit 4 has a rotating shaft 4a at the center thereof and a support frame 4b fixed to the rotating shaft 4a, and the developing devices 4Y and 4C for the four colors described above. , 4M, 4K are fixed radially around a rotation shaft 4a to a support frame 4b by fixing brackets (not shown). A drive unit (not shown) is connected to the rotation shaft 4a via a clutch. By driving this drive unit, the support frame 4b is rotated, and the four developing units 4Y, 4C, 4M, and 4K are driven. One developing unit can be selectively positioned at a developing position DP (FIG. 3) facing the photoconductor 2. Thus, in this embodiment,
The support frame 4b corresponds to the "developing device holding means" of the present invention.

The developing units 4Y, 4C, 4M, and 4K held on the support frame 4b have the same configuration. Therefore, here, the configuration of the developing device 4Y will be described in detail, and the other developing devices 4C, 4M, and 4K will be denoted by the same reference numerals, and description of the configuration will be omitted.

In the developing device 4Y, the two housing members 4
A housing 43, which is a unit of the developing device, is formed by integrally combining the developing devices 1 and 42. The inside of the housing 43 is partitioned into a toner storage section 44 and a toner storage section 45 by a partition wall 411 protruding from a substantially central portion of the housing member 41 toward the housing member 42. The toner storage unit 44 is a space in which yellow toner is stored in advance, while the toner storage unit 45 receives the toner T corresponding to the amount used during toner development from the toner storage unit 44, and during toner development processing, This is a space for storing toner to be used for development. Therefore, in this embodiment, the toner storage section 44 is set relatively large as compared with the toner storage section 45.

The toner storing section 45 includes a supply roller 4
6 is arranged, and rotates in the whiz direction with the developing roller 47 while being in contact with the developing roller 47 that is rotationally driven on the most distal end side of the housing 43. That is, in this embodiment, the developing roller 47 rotates in the direction D2 opposite to the rotational direction D1 of the photosensitive member 2 while carrying the toner T, and the developing position D
The toner P is configured to adhere to the surface of the photoconductor 2 at P (FIG. 3). Then, in order to supply the toner T to the developing roller 47, a contact position CP which is upstream with respect to the developing position DP in the rotation direction D2 of the developing roller 47.
In FIG. 3, the supply roller 46 rotates in the direction D3 opposite to the rotation direction D2 of the development roller 47 while contacting the development roller 47. As a result, the yellow toner T is rubbed against the surface of the developing roller 47 to have a predetermined thickness (for example, several tens μm).
m) is formed on the surface of the developing roller 47. Thus, in this embodiment, the supply roller 46 and the developing roller 47 function as the “toner supply member” and the “toner carrier” of the present invention, respectively.

Further, at a contact position EP (FIG. 3) sandwiched between the contact position CP and the developing position DP, a regulating blade 48 corresponding to the "regulating means" of the present invention is disposed. The regulating blade 48 includes a plate-shaped member 481 such as stainless steel or copper, and an elastic member 482 such as a rubber or resin member attached to the tip of the plate-shaped member 481. The rear end of the plate member 481 is fixed to the housing member 41 in a so-called counter state. That is, in the rotation direction D2 of the developing roller 47, the elastic member 482 attached to the front end of the plate-shaped member 481 is disposed upstream of the rear end of the plate-shaped member 481. The elastic member 482 is positioned at the contact position E
P elastically contacts the surface of the developing roller 47. For this reason, the thickness of the toner layer formed on the surface of the developing roller 47 by the regulating blade 48 is finally regulated to about 10 μm. At this time, the toner is charged to a predetermined polarity by friction with the regulating blade 48. In this way, the toner T charged to a predetermined polarity with respect to the developing roller 47 is supplied to the developing position DP, and the electrostatic latent image on the photoconductor 2 can be developed by the toner T on the developing roller 47. On the other hand, the developing roller 47 is controlled by the regulating blade 48.
Surplus toner scraped from the toner, that is, the deteriorated toner DT
Is scattered in the post-regulation space SP facing the supply roller 46, the development roller 47, and the regulation blade 48.

As shown in FIG. 3, the post-regulation space SP includes a bottom portion 412 of the housing member 41 and a partition wall 411.
And the supply roller 46 communicates with the toner storage section 45 through a communication path R. For this reason, the deteriorated toner DT that has scattered in the post-regulation space SP during the development processing by the developing device 4Y is not affected by the bottom 412 of the housing member 41.
It is deposited on. As described above, in this embodiment, the bottom 412 and the partition 411 of the housing member 41 function as “communication means” of the present invention.

Further, on the communication path R, polyethylene terephthalate (PET) or polypropylene (PP)
A valve member 49 made of a resin film such as the above is disposed in a trail state as “toner flow control means” of the present invention.
That is, one end 49 a of the valve member 49 is hingedly attached to the partition 411 so as to be swingable with respect to the partition 411, while the other end 49 b is in contact with the outer peripheral surface of the supply roller 46. It is provided as possible. Also,
In this embodiment, the rotation direction D3 of the supply roller 46 corresponds to the rotation of the supply roller 46 in the direction D3 opposite to the rotation direction D2 of the
, One end (oscillation support shaft portion) 49a of the valve member 49
Is disposed upstream of the other end (tip portion) 49 b of the valve member 49. For this reason, as will be described below, the other end 4 is moved by its own weight according to the rotational position of the developing device.
9b moves toward and away from the supply roller 46 to prevent the toner from flowing from the toner storage unit 45 to the post-regulation space SP due to the abutment, while causing the toner to flow from the post-regulation space SP to the toner storage unit 45 by separation. Is possible.

Here, the operation of the rotary developing unit 4 configured as described above will be described with respect to the yellow developing unit 4.
The operation of Y will be mainly described. In this embodiment, while forming toner images in the order of yellow (Y), cyan (C), magenta (M), and black (K), each toner image is superimposed on the intermediate transfer belt 71 to form a color image. I do. Therefore, first, the yellow developing device 4Y is selectively positioned at the developing position DP (FIG. 3) facing the photoconductor 2. In this state, the valve member 49 falls down toward the supply roller 46 by its own weight, and the other end 49b is
Is in contact with the surrounding surface. Therefore, the flow of fresh toner from the toner storage section 45 into the post-regulation space SP is prevented during the toner development by the developing device 4Y. Is empty. Then, as the development process proceeds, only the toner generated at the contact position CP or the contact position EP during the development process, that is, the deteriorated toner DT is regulated while the toner inflow from the toner storage unit 45 is blocked. It is captured in the back space SP.

When the developing process by the developing unit 4Y is completed, the developing unit 4 is rotated every time the toner color is switched so as to sequentially execute the developing process using the cyan toner, the developing process using the magenta toner, and the developing process using the black toner. 1 and 2 around the shaft 4a in a counterclockwise direction by 90 degrees. In the course of switching from the yellow developing device 4Y to the cyan developing device 4C in this way, the valve member 49 falls down to the side opposite to the supply roller 46 by its own weight, and the other end 49b separates from the peripheral surface of the supply roller 46, and this separating operation The toner stored in the toner storage unit 45 starts to flow out to the toner storage unit 44 side in conjunction with. When the developing unit 4 rotates by 90 °, the yellow developing device 4Y is moved and positioned at the position of the black developing device 4K in FIG.

When the developing process using the cyan toner is completed and the switching operation from the cyan developing device 4C to the magenta developing device 4M is started, for example, as shown in FIG. Deteriorated toner DT
Flows out along the partition 411 to the toner storage section 45 and further to the toner storage section 44 side. Thus, the deteriorated toner D
T is reliably collected from the post-regulation space SP. Then, in the toner storage section 44, the toner is sufficiently mixed with the fresh toner, so that an image defect due to the deteriorated toner can be further suppressed. As a result, the latent image on the photosensitive member 2 can be developed with high quality and stably.

Further, as the developing unit 4 rotates, the yellow developing unit 4Y is moved and positioned at the position of the magenta developing unit 4M in FIG. In this state, the deteriorated toner almost completely flows out of the communication path R, and the regulated space SP returns to an empty state again. As described above, during the development processing, the deteriorated toner DT is transferred by the communication path R due to the regulated space SP.
The developing process by the yellow developing unit 4Y is completed, and the deteriorated toner is collected in the toner storage unit 45 during switching to the other developing units 4C, 4M, and 4K. The other developing units 4C, 4M, and 4K operate in exactly the same manner as the yellow developing unit 4Y.

As described above, according to this embodiment, by arranging the valve member 49 functioning as the "toner flow control means" on the communication path R, the deteriorated toner DT generated during the developing process can be reduced. After the development processing is completed, the deteriorated toner DT can be reliably collected in the toner storage section 45 during the toner development by another developing device. In addition, the deteriorated toner thus collected is mixed not only with the toner stored in the toner storage unit 45 but also with the toner stored in the toner storage unit 44 while the rotary developing unit 4 is rotating. Therefore, it is possible to effectively suppress the deterioration of the image quality due to the deteriorated toner, and stably develop the latent image on the image carrier with high quality.

The provision of the valve member 49 restricts the flow of toner from the toner storage section 45 into the post-regulation space SP during the developing process, and prevents the post-regulation space SP from being in a powder state. Can be prevented.

Furthermore, in this embodiment, since the regulating blade 48 is fixed to the housing member 41 in a counter state with respect to the developing roller 47, the regulating blade 48 contacts the peripheral surface of the developing roller 47 at an obtuse angle. That is, the toner scraped off from the developing roller 47 by the regulating blade 48, that is, the deteriorated toner DT can be guided to the post-regulation space, which is advantageous in that the collection efficiency of the deteriorated toner DT is improved.

The present invention is not limited to the above embodiment, and various changes other than those described above can be made without departing from the gist of the present invention. For example, the developing device according to the above-described embodiment is the rotary developing unit 4 in which the supply roller 46 rotates with respect to the developing roller 47, but the present invention rotates the supply roller 46 against the developing roller 47. It is applicable to a rotary developing unit. This will be described with reference to FIG.

FIG. 5 is a view showing another embodiment of the developing device according to the present invention. Each of the developing units 4Y, 4C, 4M, and 4K constituting the rotary developing unit is significantly different from the previous embodiment in the following two points. First, in this embodiment, the supply roller 46 is configured to rotate in the same direction D4 as the rotation direction D2 of the developing roller 47, that is, to perform so-called opposite rotation. To cope with this, the valve member 49 is arranged in a counter state.
That is, in the rotation direction D4 of the supply roller 46, the one end (oscillation support shaft portion) 49a of the valve member 49 is disposed downstream of the other end (tip portion) 49b of the valve member 49. I have. For this reason, similarly to the above-described embodiment, while restricting the toner from flowing into the post-regulation space SP from the toner storage unit 45 during the development process, the deteriorated toner DT generated due to the development process is removed from the post-regulation space SP. And deposited on the bottom 412 of the housing member 41.
The deteriorated toner DT thus captured is collected in the toner storage unit 45 and mixed with the fresh toner in the same manner as in the previous embodiment, so that the deterioration of the image quality due to the deteriorated toner can be effectively prevented. .

The valve member 49 may be disposed at any position on the communication path. However, as in the above-described embodiment (FIGS. 3 and 5), the regulating blade 48 has a contact position in the vertical direction. When the valve member 49 is disposed below the CP, it is preferable to provide the one end (oscillation support shaft portion) 49a of the valve member 49 below the virtual horizontal line X passing through the rotation center of the supply roller 46. is there. This is because, by arranging in this manner, the area of the peripheral surface of the supply roller 46 that rubs against the fresh toner in the toner storage section 45 becomes larger, and the peripheral surface of the supply roller 46 reaches the contact position CP as the rubbing area increases. By this time, the amount of preliminary charge given to the toner adhering to the supply roller 46 increases. As a result, the toner can be more reliably charged.

Further, in the above embodiment, the valve member 49 swings by its own weight in accordance with the rotation of the rotary developing unit 4, but a rotational driving force is applied to one end 49a of the valve member 49 to force the valve member 49. Needless to say, it may be configured such that it is swingably driven.

In the above embodiment, the regulating blade 4
8 is arranged in a counter state with respect to the developing roller 47, but such a configuration itself is not an essential configuration of the present invention, and a developing device in which the regulating blade 48 is arranged in a trail state with respect to the developing roller 47 is used. Alternatively, the present invention may be applied.

Further, in the above embodiment, the regulating blade 48 in which the elastic member 482 is attached to the tip of the plate member 481 is used as the regulating means, but a plate blade made of stainless steel or copper is adopted. Needless to say, the present invention can be applied to any developing device.

[0037]

As described above, according to the present invention, the post-regulation space is communicated with the toner storage section by the communication means, and the toner flow control means is provided on the communication path so that the toner storage section can be moved from the post-regulation space to the toner storage section. While restricting toner flow from the toner storage section to the post-regulation space while restricting toner inflow from the toner storage section during development processing. After the developing process is completed by the developing device, the deteriorated toner captured in the regulated space flows out of the regulated space into the toner storage unit through the toner flow control unit with the rotation of each developing device. Can be recovered. Therefore, the collection efficiency of the deteriorated toner is improved, image defects due to the deteriorated toner are suppressed, and the latent image on the image carrier can be developed with high quality and stably.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an image forming apparatus equipped with an embodiment of a developing device according to the present invention.

FIG. 2 is a view showing a rotary developing unit as an embodiment of the developing device according to the present invention.

FIG. 3 is a partially enlarged view of the developing device of FIG. 2;

FIG. 4 is a diagram for explaining a recovery operation of the deteriorated toner in the developing device of FIG. 2;

FIG. 5 is a view showing another embodiment of the developing device according to the present invention.

FIG. 6 is a diagram for explaining an arrangement position of a valve member.

[Explanation of symbols]

 2 Photoconductor (image carrier) 4 Rotary developing unit 4Y, 4C, 4M, 4K Developing device 4a Rotating shaft 4b Support frame (developing device holding means) 45 Toner storage unit 46 Supply roller (toner supply 47) developing roller (toner carrier) 48 ... regulating blade (regulating means) 49 ... valve member (toner flow control means) 49a ... one end (of valve member) 49b ... other end (of valve member) 411 ... partition wall (Communication means) 412 Bottom (communication means) 481 Plate member 482 Elastic member CP Contact position D1 Rotation direction (of image carrier) D2 Rotation direction of toner carrier D3, D4 (Toner) Rotation direction of the supply body DP: development position EP: contact position R: communication path T: toner X: virtual horizontal line

Claims (6)

[Claims] 1. A developing device for developing a latent image formed on an image carrier with toner, and a developing device rotatably provided and holding the developing devices arranged in a rotational direction. Device holding means, and by rotationally positioning the developing device holding means, one of the plurality of developing devices is selectively disposed to face the image carrier, and the latent image is A developing device for performing toner development, wherein each developing device includes: a toner storage unit that stores toner; and a toner carrier that conveys the toner to a development position facing the image carrier by rotating while carrying the toner. Rotating the toner carrier in contact with the toner carrier upstream of the developing position in the rotational direction of the toner carrier to transfer the toner in the toner reservoir to the toner carrier. A toner supply body to be supplied, a contact position where the toner carrier and the toner supply body are in contact with each other, and a contact position sandwiched between the developing position and a surplus toner. Regulating means for forming a charged toner thin layer on the surface, forming a communication path from the regulated space facing the toner carrier, the toner supply body and the regulating means to the toner storage section, and A communication unit that communicates with the toner storage unit; provided on the communication path to allow the toner to flow from the post-regulation space to the toner storage unit, and from the toner storage unit to the post-regulation space. A developing device comprising: toner flow control means for restricting toner flow. 2. The toner flow control means has one end rotatably supported by the communication means and the other end capable of abutting the outer peripheral surface of the toner supply body. The developing device according to claim 1, further comprising a valve member. 3. The toner supply member is rotating in a direction opposite to the rotation direction of the toner carrier, and the valve member is configured to rotate in a rotation direction of the toner supply member.
3. The developing device according to claim 2, wherein one end of the developing device is located upstream of the other end. 4. The toner supply member is rotating in the same direction as the rotation direction of the toner carrier, and the valve member is configured to rotate in the rotation direction of the toner supply member.
3. The developing device according to claim 2, wherein one end of the developing device is located downstream of the other end. 5. The control means is disposed below the contact position in the vertical direction, and one end of the valve member is connected to a lower side of an imaginary horizontal line passing through a rotation center of the toner supply body. 5. The developing device according to claim 2, wherein the developing device is swingably supported by the means. 6. The restricting means is vertically lower than the contact position and has a rear end fixed.
The tip is configured to elastically contact the surface of the toner carrier at the contact position, and the tip is upstream of the rear end in the rotation direction of the toner carrier. 6. The method according to claim 1, wherein
The developing device according to any one of the above.