JP3372416B2 - Developing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile or a laser printer, and more particularly to a developing apparatus in an electrophotographic image forming apparatus for forming an image using a two-component developer composed of carrier and toner. With regard to the above, the toner is replenished as the toner is consumed, and the developer containing the carrier deteriorated with time is replaced.

[0002]

2. Description of the Related Art Conventionally, a two-component developer composed of charged carrier particles and charged toner particles which are triboelectrically adhered to the carrier particles has been widely used as being suitable for obtaining a high quality copy image. When development is performed using such a two-component developer, the toner content of the developer is consumed each time the development is repeated, the ratio to the carrier content is reduced, and as a result, the density of the formed image is reduced. . Therefore, the developer is replenished with fresh toner in an amount corresponding to the amount of consumption, but there are various problems with carrier particles as well. For example, when repeatedly used, the carrier particle surface is enhanced to enhance triboelectric charging characteristics. The coating material applied to the film may peel off and deteriorate as a carrier. Therefore, in many machines up to now, a developing unit is periodically taken out, a deteriorated carrier or developer in the developing chamber is taken out, and a new one is replaced by a service person.

Recently, for example, Japanese Patent Laid-Open No. 60-10705.
From Japanese Patent Publication No. 7, the shutter at the bottom of the developing device is opened to take out the deteriorated developer from below, and the supply developer is set in the developer feeding hopper provided at the upper part of the developing device to automatically insert it into the developing device. A configuration in which a developer is supplied has been proposed.

However, such a method of replacement is such that the entire amount is replaced after the life of the developer has expired, and there is a problem that the image quality is remarkably different immediately before and immediately after the replacement.

[0005]

Therefore, in order to obtain a stable image quality which is not affected by the life of the developer, a small amount replacement system of the developer as disclosed in, for example, JP-A-4-29271 has been proposed. ing. When this method is used, the developer is replaced little by little before it reaches the end of its life, so that the developer accommodated in the developing device does not reach the end of its life, and a stable degree of fatigue can be maintained.

However, the technique disclosed in Japanese Patent Application Laid- Open No. 4-29271 is such that if the amount of the dry two-component developer used in the developing device reaches a preset value, the used developer in the developing device is used. A part of the new toner is discharged in a preset amount, and a new developer of approximately the same amount as this discharged amount is supplied to the developing device. Must be replenished separately. Therefore, even if the supply / recovery of the developer to / from the developing device is automatically performed, when the supply developer in the developer storage tank is exhausted and replenishment is performed, or when a new storage tank is replaced, The replenishment or replacement cycle is different from the replenishment toner replenishment, and the work is troublesome. In addition, replenishment / recovery or container replacement work is required for each of the developer storage tank, the deteriorated developer collection container, and the toner storage container, and this is not a drastic solution to reduce the work burden on service personnel and operators. . Further, in order to reduce the labor required for the developer exchanging work in the publication, it is necessary to upsize the storage tank and the recovery container, and the entire apparatus becomes very large.

Therefore, in the present invention, the supply of the developer is related to the toner replenishment so that the supply of the developer can be provided for the user maintenance when the small amount of the developer is quantitatively exchanged, and moreover, it is necessary to be aware of the relationship. An object of the present invention is to provide a developing device that does not have such a developing device.

[0008]

In order to solve the above-mentioned problems, according to the present invention, a two-component developer and a fresh toner are housed in respective divided spaces, and the respective spaces are integrally connected in a horizontal arrangement. Of the storage container, a drive means for rotationally driving the storage container in the axial direction of the storage container, and a developing chamber connected to the storage container via a supply device. It is formed by fitting a shaped first space and a concentric second space, and is inclined in the same direction on the inner peripheral wall of each of the accommodating portions forming the first space and the second space. The respective spiral protrusions are formed, and the developer and the toner in the container are supplied to the developing chamber by rotating the container in one direction.

The accommodating portion forming the second space has a protrusion inserted into the center of the first space, and the stepped region of the constriction formed in the second space due to the presence of the protrusion, It is preferable if a rake wall having a shape that matches the spiral flow of carrying out the contents is provided.

It is preferable that the insides of the respective storage portions forming the respective spaces of the storage container are formed so that the developer in the storage container can be supplied faster than the toner in the storage container. is there. For example, if the spiral protrusion on the developer accommodating portion side is more inclined, its pitch is wider, or if the inside of the accommodating portion is inclined to be suitable for discharging, The discharge capacity on the agent side can be increased. Alternatively, it is preferable that the developer contained in the storage container has higher fluidity than the toner contained in the storage container.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on the embodiments shown in the drawings. FIG. 1 illustrates an image forming engine having a developing device according to the present invention. The configuration of the entire image forming engine is basically the same as that of a conventionally known one, and the charging unit 5
The surface of the photoreceptor 53 is uniformly charged by 0, and the latent image is written by the slit exposure 51 (for analog) or the laser exposure 52 (for digital). The developing device 54 visualizes the latent image. . The sheet whose timing is aligned with the visible image (toner image) moving along the photoconductor 53 by the registration roller 55 is conveyed on the guide plate 56, and the transfer device 57 transfers the toner image on the photoconductor 53. In order to stabilize the conveyance, the electricity is removed by the electricity removal brush 58 and completely separated by the action of the separation claw 59, and then the conveyance belt 60.
To the fixing device 61. The conveyed sheet is subjected to heat and pressure action by the heater 62 and the pressure roller 63 to fix the toner image. On the other hand, the photoconductor 5
The residual toner on 3 is removed and collected by the cleaning unit 64, and a new latent image can be formed. In addition,
An eraser 65 arranged between the exposure unit and the developing device 54.
Is for eliminating the charge on the surface of the photoconductor 53 so that the toner does not adhere to unnecessary portions on the photoconductor 53. Further, a paper sensor 66 arranged on the conveyor belt 60.
Is for detecting the separation state of the paper at the transfer portion, and prevents paper jamming and winding.

In the image forming engine having such a basic structure, the integrated storage container 10 is connected to the developing device 54 via the supplying device 20 and the discharging device 21. Here, a detailed configuration of the integrated storage container 10 is shown in FIG. 2a. As shown in the figure, the integrated storage container 10 is formed by fitting a first container 1 in the shape of an annular cylinder and a second container 2 concentric therewith. As can be seen in the exploded view of FIG. 2 b, the second container 2 has a protrusion 11 which is inserted into the central space of the first container 1.
On the side surface of the protrusion 11, the inner recess 1 of the first container 1 is provided.
A ridge 13 that engages 2 is formed, and both containers are fitted together.

Returning to FIG. 2a, both containers are rotated as an integral container, and in the same direction of rotation, the contents in the first container (here unused developer consisting of toner and carrier) and the second container
The contents (here, toner) in the container are discharged to the outlet side, FIG. 2a
In order to convey it to the left side as seen in, convex spirals 4 and 5 are attached to the inner peripheral wall of the container. In addition, in order to reliably discharge the content portion, the region that transitions from the large-diameter portion to the small-diameter portion of each container (the stepped region of the constricted portion of the container) has a shape that matches the spiral flow of the content discharge. Rake walls 6 and 7 are provided. A common lid 15 having a grip portion 14 is fitted into the discharge ports of both containers, and when the containers are mounted on the developing device 54, they are detached by using, for example, an automatic chuck.

Next, the actual supply of toner and developer will be described with reference to FIGS. As described above, the first container 1 of the integrated storage container shown in FIG. 2a is initially filled with a predetermined amount of unused developer. The second container 2 is filled with toner. The predetermined weight of the developer is understood as the amount of one partial replacement of the developer, and is the amount of the developer used in the developing device, the ratio to the amount of toner in the integrated storage container, the developer itself. It is determined by the degree of deterioration of Usually, about 10% of the amount of developer used in the developing device is sufficient. The unused developer is the same as the developer that has been used when the developer is replaced by a conventional service person.

When a new developer is supplied by exchanging the integrated storage container, the developer in the developing device at the time of the replacement is the same as the new developer supplied from the first container 1, which will be described later in detail. The same amount of used developer has already been collected in the storage container. New integrated storage container 1
When 0 is set on the apparatus main body side, the toner end signal is issued, and the toner concentration in the developing device is lower than the ideal toner concentration. Therefore, the toner replenishment signal is sent to the integrated storage container 10 immediately after the container is set. In response to this signal, the integrated storage container 10 rotates in the direction of arrow 40 in FIG. 3 by a drive source (not shown). The spiral protrusion 5 (Fig. 2) provided on the inner peripheral wall of the container
By the action of (a), the toner 43 is replenished from the discharge port 24. At this time, since the spiral protrusions 4 (FIG. 2A) in the same rotation direction are also provided on the inner peripheral wall of the first container 1, the unused developer in the first container is also removed as toner is replenished. It is automatically discharged from the discharge port 23. That is, the supply of the developer is performed at the same time when the toner replenishing operation is performed.

The unused developer supplied from the discharge port 23 of the integrated storage container 10 and the toner supplied from the discharge port 24 are both fed by the replenishment guide 26.
7 and the conveying screw 2 in the pipe 27
8 is discharged into the developing device 54 via the receiving port 30 formed in the upper lid portion of the developing device 54.

The unused developer and toner supplied into the developing device 54 reach the first conveying screw 31 arranged immediately below the receiving port 30. The first conveying screw 31
Is for agitating and transporting the developer from the back side to the front side of the drawing, and the second agitating screw 3 paired with the developer is conveyed.
2 is, on the contrary, for stirring and conveying the developer from the front side to the back side of the paper. Under the operation of these agitating screws, the supplied new developer / toner is uniformly mixed with the developer in the developing device 54, and then moves to the developing sleeve 33 side to expose the toner image corresponding to the latent image. It is formed on the body 53.

Next, the recovery of the deteriorated developer will be described with reference to FIGS. In FIG. 1, the developer is collected by the discharging device 21 arranged on the opposite side of the developing device 54 from the side where the supplying device 20 is attached, on the back side of the paper surface. When the new developer is supplied as described above, the developing device 5
The developer liquid level in 4 rises. And stirring screw 3
When 1 and 32 are activated, the liquid surface becomes wavy.
The used developer spilled to the discharge port 35 is transported to the integrated storage container 10 via the recovery guide 36 by the discharge device 21 including the transport pipe and the transport screw accommodated therein at the recovery time. At this time, the recovery agent spilled from the discharge port 35 is discharged from the discharge device 21 so that the recovery agent is finally easily stored in the storage container 10.
Is temporarily lifted by the hopper-shaped collection guide 3
It slides down in 6 by its own weight and flows into the storage container. The recovery agent 45 that has flowed into the storage container that rotates in the direction of the arrow 44 in FIG. 4 is guided to the bottom by the action of the inner peripheral wall projection 4 of the first container 1. The recovery guide 36 is rotatably supported around a vertical rotation shaft 37, and is retracted from the movement range of the lid 15 when the common lid 15 is attached or detached. In this embodiment, the used developer that has overflowed is stored in the container 1.
However, as another configuration, a recovery container is provided in an empty space of the apparatus main body, and the used developer discharged from the discharging device 21 is introduced into the recovery container. May be.

Next, the respective timings of supplying the unused developer and toner and collecting the used developer will be described. As described above, the unused developer is supplied to the developing device 54 along with the operation of setting the storage container 10 and replenishing the toner.
Is supplied to. The toner is replenished by rotating the storage container in the direction of arrow 40 in FIG. 3 each time the toner end on the apparatus body side is detected. Then, after the inside of the second container 2 of the storage container 10 becomes the toner end, the used developer is collected in the storage container 10. The toner end in the second container may be detected by a unique end sensor, or the toner end in the main body of the apparatus is determined to be the toner end in the second container 2 by counting a predetermined number of times. You may do it. After the toner end in the second container 2, when the toner end is detected again on the apparatus main body side, the discharging device 21 is operated, and the storage container 10 is rotated in the direction of arrow 44 in FIG. 4 to collect the used developer. To do. As described above, it may be recovered in a dedicated recovery container.

Since the overflow method is basically adopted for the recovery of the used developer, the recovery amount can be made equal to the supply amount. However, in the overflow method of the present invention, there is no space for temporarily storing the overflowed developer, and the developer in the developing device 54 is in a state where the discharging device 21 is stopped (at the time other than the collecting operation). Used as. Immediately after the used developer is collected, the amount of the developer in the developing device is smaller than that in the normal state (when the machine is operating). With such a configuration, the unused developer supplied when replacing the integrated storage container 10 is used at least up to the toner end of one storage container 10, and the unused developer is sufficient. It is not collected before it is used, is uniformly mixed with the developer already contained in the developing device, is used sufficiently, and is collected as a used developer at a constant rate.

When the developer is supplied along with the toner replenishing operation, the toner is replenished many times for each small amount of developer exchange as described above, and the toner is replenished even after the supply of the new developer is completed. It does not matter if replenishment is repeated, but the ratio of the amount of replenishment toner in the integrated storage container is low,
When the supply of the developer and the replenishment of the toner are almost completed, the unused developer in the first container must be completely supplied when the toner of the storage container ends. For that purpose, a developer having a fluidity higher than that of the toner is used. By doing so, if the rake walls 6 and 7 shown in FIG. 2 have at least the same inclination, as shown in FIG. 5, the unused developer is discharged earlier than the toner at the same rotation amount of the container. Will be completed. Further, in order to further enhance the developer discharging ability, the bottom side of the first container 1 may be inclined, the pitch of the spiral protrusions 4 may be increased, or the inclination of the protrusions may be strengthened. The supply rate of the unused developer is preferably higher than the toner discharge rate in order to stabilize the developer capacity in the developing device at an early stage.

[0022]

According to the first aspect of the present invention, the two-component developer and the fresh toner are stored in the respective divided spaces, and the horizontally arranged storage containers are integrally connected to each other. In a developing device provided with a driving means for rotationally driving the storage container in the axial direction thereof and a developing chamber connected to the storage container via a supply device, each of the spaces is a first space in the shape of an annular cylinder. And this is formed by fitting with this and the concentric second space,
Spiral protrusions that are inclined in the same direction are formed on the inner peripheral walls of the respective accommodating portions that form the first space and the second space, and by rotating the accommodating container in one direction, Since it is configured to supply the developer and the toner to the developing chamber, when the quantitative small amount developer is exchanged, the supply of the developer is automatically performed along with the toner replenishment, It will be used for user maintenance.

According to the invention of claim 2, the second
The accommodating portion that forms the space has a protruding portion that is inserted into the center of the first space, and the presence of the protruding portion forms a spiral shape for carrying out the content in the stepped region of the constricted portion formed in the second space. Since the rake wall having a shape that matches the flow is provided, the effect of claim 1 can be achieved with an extremely simple configuration.

According to the third aspect of the invention, the interior of each of the accommodating portions forming the respective spaces of the accommodating container so that the developer in the accommodating container finishes supplying faster than the toner in the accommodating container. According to the invention of claim 4, the fluidity of the developer contained in the container is
Since the fluidity of the toner in the storage container is higher than that of the toner, when the supply of the developer is accompanied by toner replenishment, the developer to be supplied remains in the container when the toner in the container is exhausted. And the container will not be replaced before the developer supply is completed.

[Brief description of drawings]

FIG. 1 is an overall schematic configuration diagram of an image forming engine including a developing device according to the present invention.

FIG. 2 is a schematic configuration diagram of an integrated storage container, in which (a) shows a connection state of each storage unit while showing a state of a spiral protrusion, and (b) shows an exploded view before the connection. It is shown.

FIG. 3 is a schematic view showing a state in the vicinity of a container outlet when supplying a developer and a toner.

FIG. 4 is a schematic view showing a state in the vicinity of a container discharge port when collecting a deteriorated developer.

FIG. 5 is a graph showing the relationship between the rotation of the storage container and the discharge amount when the developer discharge speed is faster than the toner discharge speed.

[Explanation of symbols]

1 first container 2 Second container 4,5 spiral projection 6,7 rake wall 10 Integrated storage container 15 Common lid

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Sou Kai 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. (72) Inventor Kiyonori Tsuda 1-3-6 Nakamagome, Ota-ku, Tokyo Inside the Ricoh Company (72) Inventor Satoshi Hatori 1-3-6 Nakamagome, Ota-ku, Tokyo Inside the Ricoh Company (56) Reference JP-A-6-348134 (JP, A) JP-A-4-34 118675 (JP, A) JP-A-7-20707 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 15/08

Claims (4)

(57) [Claims] 1. A horizontally arranged storage container in which a two-component developer and a fresh toner are stored in respective partitioned spaces, and the respective spaces are integrally connected, and a drive for rotationally driving the storage container in the axial direction thereof. In a developing device including means and a developing chamber connected to the storage container via a supply device, each of the spaces has an annular cylinder shape.
The space and the second space concentric with the space are fitted to each other, and spiral protrusions inclined in the same direction are formed on the inner peripheral wall of each of the accommodating portions forming the first space and the second space. A developing device, which is formed respectively, and is configured to supply the developer and the toner in the container to the developing chamber by rotating the container in one direction. 2. The accommodating portion that forms the second space has a protrusion that is inserted into the center of the first space, and the presence of the protrusion causes the stepped region of the constriction formed in the second space. Is provided with a rake wall having a shape matching the spiral flow of carrying out the contents.
The developing device according to 1. 3. The inside of each accommodating portion forming each space of the accommodating container is formed so that the developer in the accommodating container finishes supplying faster than the toner in the accommodating container. The developing device according to claim 1. 4. The developing device according to claim 1, wherein the developer contained in the storage container has a higher fluidity than the toner contained in the storage container.