JPS63129368A - Developing device - Google Patents

Abstract

PURPOSE:To supply the same amount of toner as consumed toner in a developer to a containing part from a hopper and to keep the toner concentration in the developer almost constant by providing a partition means with plural opening holes and an agitating means agitating a developer in a developer containing part. CONSTITUTION:The toner in the developer 14 is used by a developing action to develop a gap equivalent to the volume of the consumed toner in the containing part 16, and a fresh toner goes into the containing part 16 through the opening holes of the partition 24 from the hopper. When the volume of the developer 14 in the containing part 16 increases to its initial level, an agitating action inhibits an excessive toner from entering, whereby the developer 14 maintains almost the same toner concentration as in an initial state. By amplifying the agitating action in the developer containing part 16, an agitating vane 26 agitates and mixes the toner supplied from the hopper with the developer in the developer containing part 16 to speed up the electrostatic charge of the toner, and functions so that the toner can have an electrostatic charge amount enough to develop satisfactorily. Simultaneously the vane 26 homogenizes the developer and minimizes the unevenness of the toner concentration.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a developing device most suitable for use in an electrophotographic device using the so-called Carlson process, which copies an image of a document surface onto plain paper. An appropriate amount of toner is supplied to the developer according to the amount of toner consumed.
The present invention provides a developing device that can maintain the toner concentration in the developer at a substantially constant state.

2. Description of the Related Art In recent years, there has been a demand for the development of electrophotographic devices that are compact and have excellent image stability, and there has been a need for small, inexpensive, and capable developing devices that can maintain good developing conditions.

An example of the above-mentioned conventional developing device will be described below with reference to the drawings.

FIG. 4 is a side sectional view showing the configuration of a conventional developing device.

In FIG. 4, 1o is a photoreceptor as a latent image holding means;
Reference numeral 12 denotes developer supporting means (hereinafter referred to as a sleeve), which is provided facing the photoreceptor 10 . 14 is a developer supported on the sleeve 12;

Reference numeral 16 denotes the developer storage section, and 18 denotes a developer layer thickness regulating means (hereinafter referred to as a blade), which adjusts the developer supplied from the storage section 16 onto the sleeve 12 to a predetermined layer thickness. 2o is a toner storage section (hereinafter referred to as a hopper), and 22 is a roller for supplying toner from the hopper 20 to the storage section 16. In the so-called two-component developing method,
The developer 14 includes a toner for adhering to the latent image on the photoreceptor 10 to make it visible, and a carrier for triboelectrically charging this toner.
That is, since the toner is consumed during development, the toner is stored in the hopper 20 and is conveniently supplied from the flopper 20 to the storage section 16 as the toner in the developer 14 is consumed. From hopper 2o to storage section 16
The toner is supplied to the roller 22 by a roller 22. A groove is cut on the surface of the roller 22, and by rotating this roller 22, the groove on the surface of the roller 22 is cut into the hopper 2.
The toner inside 0 is scraped off and conveyed to the storage section 16 side, and the toner is dropped onto this storage section 16 and supplied.

Two methods are known for adjusting the amount of toner supplied by the rotation of the roller 22. One is for each development operation in which the developer 14 is conveyed by the sleeve 12 and the latent image on the photoreceptor 10 is developed.
By always rotating the roller 22 for a certain period of time, a certain amount of toner is supplied from the pumper 20 to the storage section 16 regardless of the amount of toner that is consumed by adhering to the photoreceptor 10 from the toner. This is the so-called quantitative feeding method. Another method is to detect the toner concentration in the developer 14 with some kind of toner, rotate the roller 22 when the toner concentration becomes lower than a predetermined value, and move the developer 14 to the hopper until the toner concentration reaches the predetermined value. Toner is supplied from 20 to the storage section 16.

Problems to be Solved by the Invention However, while the quantitative feeding method is structurally relatively simple and can be manufactured at low cost, the hopper 20
Since a constant amount of toner is always supplied to the storage unit 16 from the developer 14, if the amount of toner consumed from the developer 14 is larger than the constant supply amount, the toner concentration in the developer 14 gradually decreases, and as a result, the developer There is a problem in that the density of the image produced decreases, and if the amount of toner consumed from the developer is less than the above-mentioned constant supply amount, the toner concentration in the developer 14 gradually increases. However, there is a problem in that so-called fog occurs in the developed image, making it difficult to make good copies. Furthermore, in the method using a detection sensor, the toner concentration in the developer 14 can be kept approximately constant and a good development state can be maintained. There is a problem in that it is expensive and difficult to apply mainly to high-end models. Furthermore, in either of these two methods, the hopper 20 and the storage section 16 are normally cut off, and an intermittent toner feeding means supplies toner from the hopper 20 to the storage section 16 in accordance with the developing operation or in accordance with a signal from a detection sensor. The roller 22 is required, which makes the developing device expensive and has a complicated structure.

In view of the above-mentioned problems, the present invention provides the developer 14 that is consumed by developing the latent image on the photoreceptor 10 without using an expensive toner concentration detection sensor, its attached circuit, or an intermittent toner feeding means. Toner corresponding to the amount of toner inside is supplied from the hopper 20 to the storage section 16 and the developer 14 is
The purpose of the present invention is to provide an inexpensive developing device with a simple configuration that can maintain a good developing state by keeping the toner concentration substantially constant.

Means for Solving the Problems The developing device of the present invention includes a developer supporting means provided opposite to the latent image holding means for supporting and transporting the developer, and a developer supporting means for supporting and conveying the developer, and a developer supporting means for supporting and conveying the developer, and a developer supporting means for supporting and conveying the developer, and a developer supporting means for supporting and transporting the developer, and a developer supporting means for supporting and conveying the developer, and a developer supporting means for supporting and conveying the developer, and a developer supporting means for supporting and transporting the developer. a layer thickness regulating means for regulating the layer thickness of the developer in contact with the holding means; a developer storage section for containing the developer; and a toner for adhering to the latent image and visualizing the latent image; a toner storage section for supplying the toner to the developer storage section; a partition means having a plurality of openings provided between the developer storage section and the toner storage section; The developer stirring means is provided in the developer stirring means.

Effect of the present invention With the above-described configuration, when the toner concentration in the developer is at an initial predetermined value, the above-mentioned limiting means prevents toner from entering from the toner accommodating portion to the developer accommodating portion, and also prevents the toner from entering the developer accommodating portion. By supplying toner from the toner accommodating section to the developer accommodating section through the plurality of openings of the above-mentioned limiting means as the toner is consumed, the developer can be kept in its initial state regardless of the amount of toner consumed. A homogeneous developer having the amount of charge necessary for development is obtained by maintaining an equal constant state and by mixing and stirring the developer and toner with a developer stirring means provided in the developer storage section. It is something that can be done.

EXAMPLE Hereinafter, a developing device according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a side sectional view showing the configuration of a developing device in an embodiment of the present invention. In FIG. 1, 1° is a photoreceptor as a latent image holding means, and 12 is a developer supporting means (hereinafter referred to as a sleeve) which is provided facing the photoreceptor 1o. 1
4 is a developer supported on the sleeve 12, and 16 is a storage portion for the developer.

Reference numeral 18 denotes a developer layer thickness regulating means (hereinafter referred to as a blade), which adjusts the developer supplied onto the sleeve 12 from the storage portion 16 to a predetermined layer thickness. 2o is a toner storage unit (hereinafter referred to as hopper), 24 is a partition plate that connects the hopper 20
and the storage section 16 so as to separate the two. The partition plate 24 is provided with a plurality of openings over its entire surface, and toner is supplied from the hopper 20 to the storage section 16 through these openings.

Reference numeral 26 denotes a stirring blade, which continues to rotate during the development operation in order to mix the toner supplied from the hopper 20 with the developer in the storage unit 16 and stir it to promote charging of the toner and to create a homogeneous developer. are doing.

The operation of the developing device constructed as described above will be described below with reference to FIG. 1 and FIGS. 2a and 2b. Second
Figure a is a front view showing the initial state of the developing device of the present invention. A storage portion 16 is filled with a developer 14 having a predetermined toner concentration, and as the sleeve 12 rotates in the direction of an arrow 27, a predetermined layer thickness of developer regulated by a blade 18 is supported and conveyed onto the sleeve 12. . When the blade 18 regulates the layer thickness of the developer 14 by this rotation of the sleeve 12, the developer moves behind the blade 18 in the IJ-sphere rotational direction 27 as shown by an arrow 28. That is, the developer in the storage portion 16 is transferred in the direction of the arrow 27 by the rotation of the sleeve 12, and a portion of the developer is transferred to the blade 1.
8 and the sleeve 12 to form a developer layer of a predetermined thickness on the sleeve 12. However, the excess developer regulated by the blade 18 is returned toward the storage section 16 and is stored inside the storage section 16. Creates an agitation movement of the developer.

In the initial state, the developer 14 is filled in the storage portion 16, and the agitation movement of the developer prevents toner from entering the storage portion 16 from the hopper 20 through the opening in the partition plate 24. There is.

FIG. 2 shows a state in which the toner in the developer 14 has been consumed by the developing operation. In this state, a space corresponding to the volume of the consumed toner is created in the storage section 16. The agitation movement 28 of the developer 14 in the storage portion 16 described above occurs in the same way as in the case of the same device, but in the space corresponding to the volume of the consumed toner, the toner enters due to this agitation movement 28. There is no action to prevent this, and the toner enters the storage portion 16 from the hopper 20 through the opening in the partition plate 24. The toner that has entered the storage section 16 is mixed into the developer 14 and stirred by the stirring movement 28, thereby increasing the volume of the developer 14 within the storage section 16. When the volume of the developer 14 in the storage portion 16 increases to the initial state shown in FIG. Approximately the same amount of toner as consumed is replenished, and the toner concentration is maintained approximately equal to the initial state.

The agitating blade 26 amplifies the agitating motion within the developer accommodating section 16 to mix and stir the toner supplied from the hopper 20 with the developer within the developer accommodating section 16 to promote charging of the toner, thereby improving the charging of the toner. It acts so that the toner has a sufficient amount of charge for proper development, and also has the effect of making the developer homogeneous and reducing unevenness in toner concentration. In addition, in order to enhance the agitation effect of the developer in the developer storage portion 16, especially the agitation effect in the direction perpendicular to the direction of rotation of the sleeve 12,
It is effective to provide the stirring blade 26 with an inclined blade that is inclined with respect to the rotational direction so as to swing the developer in the lateral direction with respect to the rotational direction of the stirring blade 26.

It is possible to improve the homogeneity of the developer and to further reduce unevenness in toner density. FIG. 3 shows a perspective view of the stirring blade 26 having inclined blades.

Here, the following points are important regarding how the partition plate 24 controls the supply of toner from the hopper 20 as described above. First, the partition plate 24 can hold the developer filled in the storage portion 16, and second, the plurality of apertures provided in the partition plate 24.

Each has a size sufficient to allow the toner to pass through. For example, if the partition plate 24 is removed,
The developer 14 enters the hopper 20 due to the agitation movement generated in the storage portion 16, and the toner in the hopper 20 enters the developer 14 without restriction, thereby significantly increasing the toner concentration in the developer. Further, the same is true when, for example, about half of the upper or lower part of the partition plate 24 is cut out to form an opening and used as a toner supply port, and toner flows into the developer 14 from the opening without restriction. In other words, the partition plate 24 having a plurality of holes is connected to the storage section 16 and the hopper 2.
It is necessary for the control of toner supply that the developer filled in the storage portion 16 is held by this partition plate 24 between the storage portion 16 and the storage portion 16 .

An example of a ready-made material having a plurality of apertures over its entire surface is a mesh. In an experiment, a 20-mesh non-magnetic stainless steel mesh was used as the partition plate 24, the toner concentration in the developer was set to 7, and the hopper was filled with toner. No capri was seen on the top, and when I made continuous copies using Dataquest's test chart with a 36.5% blackening rate and a standard original with a blackening rate of 6%, the toner in the hopper 20 was consumed. It was possible to maintain a good developing state until the image was completely exhausted.

As described above, according to this embodiment, the toner is distributed over the entire area between the developer storage section filled with developer having a predetermined toner concentration and the hopper that stores the toner.

By providing a 2° mesh net as the barrier means 24 having a plurality of openings, when the toner concentration in the developer is at an initial predetermined value, it is possible to prevent toner from entering from the hopper to the developer storage section. As the toner in the developer is consumed, the toner is supplied from the hopper to the developer accommodating portion through the openings in the screen serving as the squeezing means,
It was possible to maintain the developer in a constant state substantially equal to the initial state, regardless of the amount of toner consumption.

In addition, in the above embodiment, a ready-made net was used as the separating means 24, but the separating means 24 is particularly limited to a net as long as it is a member provided with a plurality of openings that meet the above-mentioned requirements. Moreover, it is not necessary to have openings over the entire surface. Furthermore, in the above embodiment, the restriction means 24
Although a non-magnetic material was used as the sleeve, the carrier in the developer is usually a magnetic material, and a member having magnetomotive force is usually provided inside the sleeve.
The retention effect of the developer in the developer accommodating portion 16 by the barrier means 24 is rather stronger when a magnetic material is used as the barrier means 24. Therefore, using a magnetic material for at least the portion of the restricting means 24 having the openings will further ensure the effects of the present invention. Further, in the above embodiment, the supply of toner to the developer in so-called two-component development was explained, but also in so-called one-component development where the developer and toner are the same, the toner stirring/transporting section and the toner storage section are connected. It is possible to separate the toner and replenish the toner consumed by development while stirring and transporting the toner under certain conditions in the developer storage section, which has the effect of maintaining stable developing conditions. The scope of application of the present invention is not limited only to two-component development.

Effects of the Invention As described above, the present invention has a developer supporting means provided opposite to the latent image holding means for supporting and conveying the developer, and a developer supporting means provided on the developer supporting means to support the latent image holding means. a layer thickness regulating means for regulating the layer thickness of the developer in contact with the developer; a developer storage section for storing the developer; and a developer storage section for storing toner for adhering to the latent image and making it visible. a toner storage section for supplying the toner to the developer storage section; and a partition means provided between the developer storage section and the toner storage section, the partition means having a plurality of openings. As a result, as the toner in the developer supported and conveyed by the developer support means is consumed, toner is supplied from the toner storage section to the developer storage section through the opening of the diaphragm. The developer is kept in a constant state substantially equal to the initial state regardless of the amount of toner consumed, and the developer stirring means provided in the developer storage unit mixes and stirs the developer and toner. By doing so, it is possible to obtain a homogeneous developer having the amount of charge required for development.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing the configuration of a developing device in an embodiment of the present invention, Fig. 2 is an explanatory diagram of the operation of the developing device in the embodiment shown in Fig. 1, and Fig. 3 is a part thereof. The perspective view and FIG. 4 are side sectional views showing the structure of an example of a conventional developing device. 10...Photoreceptor, 12...Sleeve,
14...Developer, 16...Developer storage section, 18...Blade, 20...Hopper, 22...Toner supply roller , 24...
...Shield plate, 26...Stirring blade, 2a...
...Sleeve rotation direction, 28...Agitation movement of developer. Name of agent: Patent attorney Toshio Nakao and one other person lθ
- Bald, light body 12 - Sleeve / 4 - At first glance scratch smooth l 16 - - Demisuku f”l 8 Matanato 18 - Blade 20 - 11 years old, horn - 24-1, cut version No. Figure 2 Figure 3

Claims (4)

[Claims] (1) A developer support means provided opposite to the latent image holding means for supporting and conveying the developer, and regulating the layer thickness of the developer facing the latent image holding means on the developer support means. a layer thickness regulating means for accommodating the developer, a developer accommodating section for accommodating the developer, and a toner accommodating section for accommodating toner for adhering to the latent image to make it visible and supplying the toner to the developer accommodating section. a partitioning means having a plurality of openings provided between the developer storage part and the toner storage part, and a developer stirring means provided in the developer storage part, As the toner in the developer supported and conveyed by the developer support means is consumed, toner is supplied from the toner storage section to the developer storage section through the opening of the partitioning means, and the toner is supplied to the developer storage section through the opening of the partitioning means. A developing device characterized in that it is configured to be mixed and stirred with a developer by a stirring means so that the developer is maintained in a substantially constant state regardless of the amount of toner consumption. (2) At least a part of the partitioning means provided between the developer storage section and the toner storage section is made of a mesh material, and the mesh of the mesh material is made into an opening, and the toner is passed through the mesh. The developing device according to claim 1, characterized in that the toner is supplied from the storage section to the developer storage section. (3) The developing device according to claim 1 or 2, wherein the developer stirring means provided in the developer storage section is a rotatable stirring blade. (4) The rotatable stirring blade includes an inclined blade that is inclined with respect to the rotation direction thereof, and is configured to swing the developer in a side direction with respect to the rotation direction of the stirring blade with the inclined blade. A developing device according to claim 3, characterized in that: