JPH063950A - Developing device - Google Patents

Abstract

PURPOSE:To provide a developing device capable of obtaining excellent image quality without the mark of the replenishment of toner, surface staining, etc., even in a small sized developing device having a small space for stirring a developer. CONSTITUTION:A stirring member driving means 51 used exclusively for independently driving a stirring roller 50 is provided and the revolving speed of the stirring roller 50 is controlled by a revolving speed controller 52 via the stirring member driving means 51 so that the revolving speed r2 of the stirring roller 50 in an image nonvisualizing process is made higher than the revolving speed r1 of the stirring roller 50 in an image visualizing process for making an electrostatic latent image formed on a photosensitive body 1 visualizable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device in an image forming apparatus such as a copying machine, a printer and a facsimile.

[0002]

2. Description of the Related Art In recent years, with the demand for miniaturization and personalization of image forming apparatuses using electrophotography such as copying machines and printers, the development apparatus has been miniaturized. Further, in response to such a request, when the toner is used up, a developing device of a disposable type that is replaced with the developing device, and in addition to this developing device, a latent image carrier on which an electrostatic latent image of an original image is formed (Photoreceptor), and a cleaning unit for removing the toner remaining on the photoreceptor are integrated.
So-called process cartridges have become widely used in general.

However, in such a disposable type developing device or process cartridge in which each unit is exchanged, the amount of the developer consisting of the toner and the carrier is small, and the space for the developer stirring section is inevitably reduced. Therefore, it takes a short time for the replenished toner to reach the developing area (toner agitating / conveying section), and the agitating of the replenished toner and the developer (carrier) becomes insufficient, and the toner charge amount is small. Therefore, the floating toner is likely to be generated. When this floating toner is generated, the background stain on the transfer paper becomes severe. Therefore, in this type of developing device, the initial image quality is maintained despite the large amount of toner remaining in the developer. Therefore, since the developer or the developing device must be replaced, there is a problem in that the replacement and the disposal process are troublesome and costly.

In order to solve such a problem, conventionally,
For example, as described in JP-A-57-120965, by increasing the number of rotations of the stirring blade and the scooping sleeve of the toner stirring and conveying unit as the number of developed sheets increases, the charge amount of the developer is reduced. The same applicant as the present application has proposed a "deterioration preventing method for a dry electrophotographic developing machine" which prevents the deterioration and maintains the initial image quality.

[0005]

By the way, in the above-mentioned conventional developing device, the toner agitating and conveying means for agitating and conveying the toner and the developer replenished to the toner agitating and conveying section, that is, the developing for carrying and conveying the developer. The developing sleeve, the scooping sleeve, the stirring blade, and the like as the agent carrier are configured to rotate in association with each other by one driving means including a gear train. Therefore, in this conventional developing device, in order to maintain the initial image quality, when the number of rotations of the stirring blade and the scooping sleeve of the toner stirring and conveying unit is increased as the number of developing sheets is increased, The number of revolutions of the developing sleeve is also increased in association with the increase, and the amount of toner supplied from the developing sleeve becomes larger than necessary.

Therefore, when the above-mentioned conventional method is applied to this conventional developing device as it is, the toner consumption amount and the toner recovery amount of the cleaning portion increase, and the developer (developing unit) and the cleaning unit are increased. There is a problem that the replacement cycle of is shortened. Further, since the developing sleeve in this type of developing device is arranged so as to keep a distance of 1 mm or less with respect to the latent image carrier (photoreceptor), the developing sleeve rotates as described above. By increasing the number, the rubbing force of the ear of the developer carried by the developing sleeve on the surface of the photoconductor is increased,
There is a problem that the wear of the surface of the photoconductor is accelerated and the life of the photoconductor is shortened.

The present invention has been made in view of the above points, and an object thereof is to obtain a good image quality without background stains even in a small-sized developing device having a small developer stirring space. To provide a developing device.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a toner replenishing section including a toner reserving chamber for reserving toner and a toner replenishing member for supplying toner from the toner reserving chamber, and a developing unit. It is composed of a stirring member that mixes the developer and the replenished toner and a toner stirring and conveying unit that is composed of a developer carrier that carries and conveys the developer, and the carrier is conveyed to the peripheral surface of the developer carrier. A developing device for visualizing an electrostatic latent image formed on a latent image carrier by a developing agent, which is provided with a dedicated stirring member drive means for independently driving the stirring member. Increase the rotation speed of the stirring member during the non-visualization process to be higher than the rotation speed of the stirring member during the visualization process that visualizes the electrostatic latent image formed on the image carrier. Let it be configured to.

In order to solve the above-mentioned problems, the present invention is replenished with a developer, and a toner replenishing portion including a toner replenishing member for replenishing toner from the toner replenishing chamber for containing toner. The toner agitating and conveying section which is composed of a stirring member for mixing toner and a developer carrier for carrying and carrying the developer, and the developer carried and carried on the peripheral surface of the developer carrier. A developing device for visualizing an electrostatic latent image formed on a latent image carrier,
In a state other than the visualizing step of visualizing the electrostatic latent image formed on the latent image carrier, a toner replenishing operation from the toner replenishing section to the toner stirring and conveying section is performed,
The setting position of the developer carrier with respect to the latent image carrier is separated to increase the rotation speed of the stirring member.

Further, in order to solve the above-mentioned problems, the present invention is replenished with a developer, and a toner replenishing section comprising a toner replenishing member for replenishing the toner and a toner replenishing member for replenishing the toner from the toner containing chamber. The toner agitating and conveying section which is composed of a stirring member for mixing toner and a developer carrier for carrying and carrying the developer, and the developer carried and carried on the peripheral surface of the developer carrier. A developing device for visualizing the electrostatic latent image formed on the latent image carrier, wherein the electrostatic latent image formed on the latent image carrier is visualized In a state other than the process, the toner replenishing operation from the toner replenishing section to the toner agitating / conveying section is performed, and the developer on the developer carrier corresponding to the developing portion of the latent image carrier is removed. So that the rotation speed of the stirring member is increased.

[0011]

According to the present invention, the number of rotations of the stirring member is independently controlled by the dedicated stirring member driving means for independently driving the stirring member, so that the stirring during the non-visualization step is performed. The number of rotations of the member is increased more than the number of rotations during the visualization process without increasing the number of rotations of the developer carrier.

Further, according to the present invention, the toner agitating and conveying from the toner replenishing section is performed in a state other than the visualizing step of visualizing the electrostatic latent image formed on the latent image carrier. The toner replenishing operation to the area is performed, and the setting position of the developer carrier with respect to the latent image carrier is separated, so that extra toner consumption is caused or the surface of the photoconductor is slid by the ear of the developer. Without rubbing, the rotation speed of the stirring member during the invisible image formation step is increased more than the rotation speed during the visible image formation step.

Further, according to the present invention, the toner agitating and conveying from the toner replenishing section is performed in a state other than the visualizing step of visualizing the electrostatic latent image formed on the latent image carrier. The toner corresponding to the latent image carrier is removed from the developer corresponding to the developing portion of the developer carrier, so that extra toner is consumed and the developer spikes. Thus, the number of rotations of the stirring member during the invisible image formation step is increased more than the number of rotations during the visible image formation step without rubbing the surface of the photoconductor.

[0014]

Embodiments of the present invention will be described in detail below with reference to the drawings. However, with respect to the configuration, operation, and the like in the range that can be clearly recalled from the description of the present specification, illustration and description thereof will be omitted or simplified in order to avoid complication of description.

First, prior to the description of the embodiments of the present invention,
The outline of the developing device in which the present invention is implemented will be described. As shown in FIG. 1, the developing device includes a developing roller 10 serving as a developer carrier, a doctor 20 that regulates the supply amount of the developer provided on the developing roller 10, and an upper portion that forms the developing device main body 2. A case 30, a lower case 40 that forms the developing device main body 2, a stirring roller 50 that stirs the developer accommodated in the developing device main body, and a toner stirring / conveying unit for the toner in the toner cartridge 70 installed in the developing device main body 2. A small hole mylar 80 that forms a partition wall between the toner agitator 60, the toner replenishing unit including the agitator 60 and the toner cartridge 70, and the toner stirring and conveying unit 100;
In addition, the developer after completion of development carried on the developing roller 10 is peeled off from the developing roller, and the toner stirring and conveying unit 1 is provided.
It is composed of a separator 90 for returning to 00.

In FIG. 1, the toner contained in the toner cartridge 70 is carried toward the small hole mylar 80 by the rotation of the agitator 60, and by the elasticity of the brush 61 fixed to the tip of the agitator 60, The toner is stirred and fed to the toner agitating and conveying section 100 through a small hole 81 (see FIG. 2) formed in the small hole mylar 80. Here, the agitator 60 includes a sensor for detecting the toner concentration during development,
By detecting a lack of toner density during development and outputting a toner replenishment signal, the toner is controlled to rotate until the toner density in the developer reaches an appropriate reference value. Further, in this embodiment, the brush 61 is used as the toner replenishing means of the toner replenishing section, but a sheet such as a polyester film may be used as the toner replenishing means.

In this way, the toner replenished in the toner agitating / conveying section 100 of the developing device main body 2 is mixed and agitated by the agitating roller 50 together with the developer contained in the toner agitating / conveying section 100. . This mixed and stirred toner (developer) is pumped up onto the peripheral surface of the developing roller 10 by the magnet 11 in the developing roller 10 and regulated by the doctor 20 to be thinned to a predetermined thickness. , And is carried and conveyed to the developing area formed by the closest portion of the photoconductor 1 and the developing roller 10. As a result, the photoconductor 1
The electrostatic latent image of the original formed on the document is visualized (developed) by the developing toner. The toner and the carrier remaining on the developing roller 10 without being consumed in the visualizing step are separated by the separator 90 from the developing roller 10.
The toner is peeled off from above and returned to the toner stirring and conveying unit 100.

By the way, in the downsized developing device as shown in this embodiment, since the amount of the developer accommodated is small and the space for the developer stirring section is inevitably reduced, the replenished toner is It takes a short time to reach the developing area (toner stirring and conveying section), the stirring of the replenishment toner and the developer (carrier) becomes insufficient, the charge amount of the toner becomes small, and floating toner easily occurs. Because,
There is a problem that toner supply marks and background stains occur. In FIG. 1, the toner replenishment trace is the small hole 81 of the small hole mylar 80.
This is a phenomenon in which the toner replenished from the toner reaches the developing area without being uniformly dispersed during development and is biasedly transferred onto the transfer paper P as shown in FIG. Further, the background stain is a phenomenon in which the toner is transferred to the background portion of the transfer paper P in a dust shape as shown in FIG.

These phenomena are phenomena in which toner having a small charge amount, which has not been sufficiently stirred with the developer, appears as floating toner, and its occurrence is suppressed by sufficiently stirring the toner and the developer. It is possible. That is, as shown in FIGS. 5 and 6, these phenomena suppress the occurrence of a predetermined time T ₀ after the new toner is replenished from the toner replenishing section of the developing device, and suppress the occurrence of the phenomenon. Can meet the standard. Here, the predetermined time T ₀ is the amount of developer stored in the developing device and the agitator 6
0 is the time individually determined by the specifications of the developing device such as the toner replenishment amount per one rotation, the outer diameter of the developing roller 10 and the stirring roller 50, and the number of rotations.

Therefore, in this type of developing device, as shown in FIG. 7, in a non-visible image forming step other than the visible image forming step of visualizing the electrostatic latent image formed on the photoconductor 1. The toner replenishment is stopped and the toner replenishment is stopped at a predetermined time T ₀ before the end of the non-visible image process, thereby preventing generation of toner replenishment traces and background stains during the visible image process. can do.

However, when the toner is supplied in the invisible image forming step as described above, as shown in FIG. 8, the time during which the toner can be supplied in the invisible image forming step, that is, The permissible time T ₂ for toner replenishment is always constant. Therefore, for example, when it is assumed that the permissible time T ₂ is set to a time that satisfies the toner replenishment required for a document having a document area ratio of 50% (a ratio of a solid image to a document area), For example, a document area ratio 60 requiring a toner replenishment time of time T ₁ e
When developing more than 100% of the original, as shown in Fig. 8,
The toner replenishment time becomes short by T ₁ e−T ₂ = ΔT time. Therefore, in this developing device, the toner replenishment shortage time ΔT is stored in the memory of the controller (not shown), and a document having an original area ratio of less than 50% that requires only the toner replenishment time of time T ₁ c is developed. At this time, the shortage time ΔT is added to replenish the toner.

By properly controlling the toner replenishment timing and the toner replenishment time as described above, it is possible to prevent the toner replenishment trace and the background stain from occurring during the visible image process. In such a developing device, for example, when a document having a document area ratio of 60% or more is developed for a long time, the toner cartridge 70 has sufficient toner to be replenished despite the fact that the toner can be replenished. , Toner shortage is detected. on the other hand,
As another method for preventing the occurrence of toner replenishment traces and background stains during the visible image process, as described above,
There is a method of increasing the rotation speed of the stirring roller 50 in FIG. 1 to sufficiently stir the toner and the developer. However, simply increasing the rotation speed of the stirring roller 50 also increases the rotation speed of the developing roller 10, so that the amount of toner consumption is significantly increased, and the developer (developing unit) or the cleaning unit is replaced. This leads to a short cycle.

Therefore, in the first embodiment of the present invention, as shown in FIG.
As shown in FIG. 10, a dedicated stirring member driving means 51 including a motor that independently drives the stirring roller 50 as a stirring member for the replenishment toner is provided, and as shown in FIG. From the rotation speed r ₁ of the stirring roller 50 during the visualization process for visualizing the electrostatic latent image formed in 1),
The rotation speed controller 52 controls the rotation speed of the stirring roller 50 via the stirring member driving means 51 so as to increase the rotation speed r ₂ of the stirring roller 50 in the non-visualization step. . According to the first embodiment, the rotation speed of the stirring roller 50 is independently controlled by the dedicated stirring member driving means 51 for independently driving the stirring roller 50, and the stirring roller at the time of the invisible image forming process is controlled. Since the number of rotations of 50 is increased more than the number of rotations of the developing roller 10 during the visualization process without increasing the number of rotations of the developing roller 10, the supply toner and the developer are not wasted. And can be sufficiently stirred and mixed, and the background stain of the transferred image and the generation of toner replenishment traces can be prevented (FIG. 11).

By the way, in the first embodiment, the rotation speed of the stirring roller 50 can be independently controlled by the dedicated stirring member driving means 51. However, in the ordinary developing device, the cost and space are reduced. Due to such restrictions, as described above, the developing roller 10 as a developer carrier that carries and conveys the developer, the stirring roller 50, and the like rotate in association with each other by one driving unit including a gear train and the like. Is configured as follows. Therefore, in this developing device, when the rotation speed of the stirring roller 50 of the toner stirring / transporting unit 100 is simply increased in order to maintain the initial image quality, the rotation speed of the stirring roller 50 increases as described above. The number of rotations of the developing roller 10 is also increased in conjunction with this, and the amount of toner supplied from the developing roller 10 is increased more than necessary, the toner consumption amount and the toner recovery amount of the cleaning unit are increased, and There is a problem that the replacement cycle of the (developing unit) and the cleaning unit becomes short. Further, since the developing roller 10 in the developing device of this type is normally arranged at a distance of 1 mm or less with respect to the photoconductor 1, the rotation speed of the developing roller 10 is increased as described above. As a result, the rubbing force of the ears of the developer carried on the developing roller 10 on the surface of the photoconductor is increased, and the abrasion of the surface of the photoconductor is promoted, which shortens the life of the photoconductor. .

Therefore, in the second embodiment of the present invention, in a state other than the visualizing step of visualizing the electrostatic latent image formed on the photoreceptor 1, that is, in the non-visible image step, The toner replenishing operation is performed from the toner replenishing section to the toner agitating / conveying section 100, the setting position of the developing roller 10 with respect to the photoconductor 1 is separated, and the rotation speed of the agitating roller 50 is increased. According to the second embodiment, in the non-visible image process other than the visualizing process of visualizing the electrostatic latent image formed on the photoconductor 1, the toner replenishing unit to the toner stirring / transporting unit 100 are performed.
Toner is supplied to the photosensitive member 1 and the setting position of the developing roller 10 with respect to the photosensitive member 1 is separated from each other, so that an invisible image is generated without causing excessive toner consumption and rubbing the surface of the photosensitive member with the brush of the developer. Since the rotation speed of the agitating roller 50 during the image formation step is higher than the rotation speed during the visible image formation step, the supply toner and the developing toner can be developed without wasting the supply toner or abrading the surface of the photoconductor. By sufficiently stirring and mixing the agent, it is possible to prevent the occurrence of background stains on the transferred image and toner supply traces. Here, the mechanism for bringing the developing roller 10 into and out of contact with the photoconductor 1 is the same as the known developing switching mechanism used in a full-color developing device, a twin-color developing device, etc., as shown in FIG. By rotating the development switching cam 13 with the solenoid 12 and swinging the development switching levers 14 and 15 by the rotation of the development switching cam 13, the developing device main body 2 (see FIG. 1) is moved relative to the photoconductor 1. It is configured to be brought into and out of contact.

By the way, in the second embodiment, the photosensitive member 1 and the developing roller 10 are separated from each other, so that the toner is excessively replenished to the photosensitive member 1 and the excessive amount of the photosensitive member 1 and the developer spikes. Although it is configured to prevent rubbing, excessive replenishment of toner to these photoconductors 1 and the photoconductor 1
Excessive rubbing between the developer and the brush of the developer can be prevented by stopping the supply of the developer onto the developing roller 10 at the time of replenishing the toner, that is, at the time of invisible image formation. Therefore, in the third embodiment of the present invention, the toner replenishing section to the toner agitating / conveying section 100 is transferred from the toner replenishing section to a state other than the visualizing step of visualizing the electrostatic latent image formed on the photoconductor 1. The toner replenishing operation is performed, the developer on the developing roller 10 corresponding to the developing portion of the photoconductor 1 is removed, and the rotation speed of the stirring roller 50 is increased.

FIG. 13 shows the developing roller 1 for the photosensitive member 1.
It is a schematic sectional drawing of the developing device of the 3rd Example provided with the brush cutting mechanism which removes the developer corresponding to the 0 development site. In FIG. 13, a magnetic plate 16 for shielding a magnetic field is provided between each magnet 11 arranged in the developing roller 10 and the developing roller 10. This magnetic plate 1
6 is formed by a magnetic plate member curved in an arc shape with a predetermined curvature, and extends in the axial direction of the cylindrical developing roller 10. The magnetic plate 16 is rotatably supported coaxially with the developing roller 16 along the inner peripheral surface of the developing roller 10. The magnetic plate 16 is basically installed so as to cover the magnet portion at the position where the developer remaining on the magnetic brush after development falls (the position shown by the solid line in FIG. 13). It functions as a magnetic body that drops the. That is, this developing roller 10
The developer after development is the magnetic plate 16 as the magnetic material.
When it reaches the region immediately below, the developer is dropped by its own weight. Therefore, in this developing device, the magnetic plate 16 is rotated to a position (a position shown by a broken line in FIG. 13) that covers the magnet, which is the position where the developer is attached, to shield the magnetic field of the magnet to which the developer is attached. As a result, the adhesion of the developer on the developing roller 10 can be stopped.

Thus, according to this third embodiment,
The toner replenishing operation from the toner replenishing section to the toner stirring and conveying section 100 is performed in a state other than the visualizing step of visualizing the electrostatic latent image formed on the photoreceptor 1 to develop the photoreceptor 1. The developer corresponding to the developing portion of the roller 10 is removed, and the rotation speed of the stirring roller 50 during the invisible image formation step is increased more than the rotation speed during the visible image formation step. Without causing toner consumption and rubbing the surface of the photoconductor with the ears of the developer, the supply toner and the developer can be sufficiently stirred and mixed to prevent background stains on the transferred image and toner supply traces. .

[0029]

According to the present invention, the rotation number of the stirring roller is independently controlled by the dedicated stirring member driving means for independently driving the stirring roller, and the rotation of the stirring roller during the non-visualization process is performed. Since the number is increased more than the number of rotations during the visualization process without increasing the number of rotations of the developing roller,
The replenishment toner can be sufficiently agitated and mixed without wasteful consumption of the replenishment toner, and the background stain of the transferred image and the generation of the toner replenishment trace can be prevented. Further, according to the present invention, The toner replenishment operation from the toner replenishment section to the toner stirring and conveying section is performed in the non-visible image step other than the visible image forming step of making the electrostatic latent image formed on the photoconductor visible, The setting position of the developing roller with respect to the body 1 is separated, and the rotation speed of the stirring roller during the invisible image formation step can be controlled without causing excessive toner consumption or rubbing the surface of the photosensitive member with the developer ears. Since the rotation speed is higher than the number of rotations during the visualization process, the replenishment toner and the developer are sufficiently agitated and mixed without wasteful consumption of the replenishment toner or abrasion of the surface of the photoconductor, and transfer. Prevents background stains on images and toner supply marks .

Further, according to the present invention, toner is supplied from the toner replenishing section to the toner stirring and conveying section in a state other than the visualizing step of visualizing the electrostatic latent image formed on the photosensitive member. The operation is performed, the developer corresponding to the developing portion of the developing roller with respect to the photoconductor is removed, and the rotation speed of the stirring roller during the invisible image formation step is higher than that during the visible image formation step. Therefore, the replenishment toner and the developer are sufficiently agitated and mixed without causing excessive toner consumption or rubbing the surface of the photoconductor with the ears of the developer, and the background stain or the toner of the transfer image is mixed. It is possible to prevent the occurrence of supply marks.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a developing device according to a first embodiment of the present invention.

FIG. 2 is a partial perspective view of a small hole mylar disposed in a toner supply portion of the developing device according to the first embodiment of the present invention.

FIG. 3 is a schematic plan view showing a toner replenishment mark on a transfer paper which is generated by development.

FIG. 4 is a schematic plan view showing a background stain on a transfer paper which is generated by development.

FIG. 5 is a graph showing a state of occurrence of toner replenishment traces with respect to time elapsed after toner replenishment.

FIG. 6 is a graph showing a background stain generation state with respect to a lapse of time after toner supply.

FIG. 7 is a diagram showing a relationship between a visible image process and an invisible image process and a toner replenishing operation of the developing device in which the present invention is carried out.

FIG. 8 is a diagram showing a relationship between toner replenishment timing and toner replenishment time of the developing device in which the present invention is carried out.

FIG. 9 is a schematic cross-sectional view of an example of a stirring roller and a driving means therefor in the first embodiment of the present invention.

FIG. 10 is a diagram showing a relationship between a visible image process and an invisible image process and a rotation number of a stirring roller in the first embodiment of the present invention.

FIG. 11 is a graph showing the relationship between the rotation number of the stirring roller and the toner replenishment mark in the first embodiment of the present invention.

FIG. 12 is a schematic perspective view of an example of a development switching unit according to a second exemplary embodiment of the present invention.

FIG. 13 is a schematic cross-sectional view of a developing device having a spike cutting mechanism according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Photoconductor 10 Development roller 11 Magnet 12 Development switching solenoid 13 Development switching cam 14,15 Development switching lever 16 Magnetic plate 20 Doctor 30 Upper case 40 Lower case 50 Stirring roller 51 Stirring member drive means 52 Rotation speed control means 60 Agitator 61 Brush 70 Toner Cartridge 80 Small Hole Mylar 81 Small Hole 90 Separator 100 Toner Stirring Conveying Part P Transfer Paper r ₁ Rotation Speed of Stirring Roller in Visualization Process r ₂ Rotation Speed of Stirring Roller in Invisible Imaging Process

Claims (3)

[Claims] 1. A toner replenishing section comprising a toner accommodating chamber for accommodating toner and a toner replenishing member for supplying toner from the toner accommodating chamber, a stirring member for mixing the developer and the replenished toner, and the developer. An electrostatic latent image formed on a latent image carrier by the developer carried on the peripheral surface of the developer carrier, which is composed of a toner agitating and transporting unit composed of a developer carrier to be carried and transported. A developing device for visualizing an image, wherein a dedicated stirring member driving means for independently driving the stirring member is provided, and the electrostatic latent image formed on the latent image carrier is visualized. The developing device is characterized in that the rotation speed of the stirring member in the non-visible image forming step is increased more than the rotation speed of the stirring member in the visible image forming step. 2. A toner replenishing section comprising a toner accommodating chamber for accommodating toner and a toner replenishing member for supplying toner from the toner accommodating chamber, a stirring member for mixing the developer and the replenished toner, and the developer. An electrostatic latent image formed on a latent image carrier by the developer carried on the peripheral surface of the developer carrier, which is composed of a toner agitating and transporting unit composed of a developer carrier to be carried and transported. A developing device for visualizing an image, wherein the toner is supplied from the toner replenishing section in a state other than a visualizing step of visualizing an electrostatic latent image formed on the latent image carrier. A developing device, which performs a toner replenishing operation to a stirring / conveying unit, separates a set position of the developer carrier with respect to the latent image carrier, and increases the rotation speed of the stirring member. 3. A toner replenishing section comprising a toner accommodating chamber for accommodating toner and a toner replenishing member for supplying toner from the toner accommodating chamber, a stirring member for mixing the developer and the replenished toner, and the developer. An electrostatic latent image formed on a latent image carrier by the developer carried on the peripheral surface of the developer carrier, which is composed of a toner agitating and transporting unit composed of a developer carrier to be carried and transported. A developing device for visualizing an image, wherein the toner is supplied from the toner replenishing section in a state other than a visualizing step of visualizing an electrostatic latent image formed on the latent image carrier. The toner replenishing operation to the agitating / conveying unit is performed, and the developer on the developer carrier corresponding to the developing portion of the latent image carrier is removed to increase the rotation speed of the agitating member. Characteristic developing device.