JPS6177074A - Printer - Google Patents

Abstract

PURPOSE:To make a developing device small-sized and inexpensive by providing a replenishing toner storage space and a developer storage space in a developer storage vessel with a partitioning member, which has a proper toner-transmissive property, between them. CONSTITUTION:A replenishing toner storage part 9 which is adjacent to a developer storage part 12 with a partitioning member 11, which has a proper toner-transmissive property, between them is provided in the right lower corner part of a developing device housing 10. The toner stored in this replenishing toner storage part 9 is loosened by minute oscillation accompanied with rotation of a developing sleeve 1 and is leaked out from gaps of the partitioning member 11 to the developer storage part 12 little by little, and the toner of the lack is attracted to a carrier to restore the toner concentration of the developer to a prescribed value, and the developer is carried to a developing part again with the developing sleeve 1 by the magnetic force.

Description

TECHNICAL FIELD The present invention relates to an electrostatic printing device such as an electrophotographic copying machine that develops an electrostatic latent image formed on a photoreceptor by a developing device using a two-component developer.

BACKGROUND OF THE INVENTION In recent years, copying machines have become more popular, and we are entering an era in which people will find one in every home and one next to the desk in the office. Furthermore, we have entered the age of colorization, and the demand for a single copying machine capable of making copies in various colors or capable of making multicolor copies is gradually increasing.

The copier used for personal use as described above makes only a small number of copies, and is desired to be small and inexpensive.

On the other hand, developing devices that use a two-component developer containing at least toner and carrier are widely used as developing devices for electrophotographic copying machines, but this type of developing device replenishes toner consumed during copying. Therefore, it is normal for the developer to come with a replenishing toner tank.
The figure shows an example of a conventional two-component developing device, in which an opening is provided in the developing device housing 1O facing the photoreceptor 6, and the developing sleeve 1 provided in the housing 10 is passed through the opening to the photoreceptor. 6 with a predetermined gap. A paddle wheel 2 is provided at the bottom of the housing 10, a fin 4 is provided at the top of the paddle wheel 2, and a doctor 3 is provided at the upstream side of the developing sleeve 1 near the photoreceptor 6', c. A toner tank 5 is removably attached to the upper part of the No-Wung IO on the side opposite to the developing sleeve 1. A toner replenishing roller 5a is provided at the bottom of the toner tank 5, and replenishes a certain amount of toner every time a predetermined number of copies are made. In order to prevent the toner in the toner tank from clumping and preventing smooth toner supply, a stirring blade 5b is provided inside the toner tank and rotates to fill the tank interior space. The operation of the conventional developing device having the above configuration is well known, so the explanation will be omitted. However, to explain the capacity of the replenishment toner tank 5, the capacity W of the toner tank is the number of copies that can be made with one toner replenishment. When the number of sheets is N, W=a+bN. Here, b is the number of times that the toner can be replenished, and a is a constant term corresponding to the capacity required for the stirring blades, etc., in addition to the amount of toner. Since the amount of copies to be made in a machine is small, there is no real inconvenience even if N is made small, so in order to reduce the capacity of the toner tank by 2,
can be made small, but in that case the constant term a
The weight that occupies in W increases. Furthermore, the same relational expression as above holds for the cost of the toner tank, but in this case, the constant term a is larger than in the case of capacity, so if N is reduced, the constant term a becomes much larger than bN. A problem occurs. Especially in the case of a multicolor copying machine equipped with multiple developing units, it becomes difficult to arrange the equipment inside the copying machine.
There are disadvantages that hinder miniaturization and increase costs.Purpose The present invention, in view of the above-mentioned circumstances of the conventional two-component developing device, provides a compact and inexpensive developing device to achieve miniaturization,
An object of the present invention is to provide an electrostatic printing device such as an electrophotographic copying machine that can achieve cost reduction.

Structure The printing device of the present invention that achieves the above object includes a replenishment toner storage space provided in the developer container of the developing device via a partition member having appropriate toner permeability to the developer storage space. Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing a developing device according to an embodiment of the present invention,
The housing lO of the developing device, which is disposed around the photoreceptor drum 6 rotating in the direction of arrow A, is provided with an opening in a portion facing the photoreceptor tram 6, and the photoreceptor drum is inserted through this opening. 6 with a predetermined gap, the developing sleeve 1 consists of a non-magnetic cylindrical member that rotates in the direction of the arrow B, with a magnet fixed therein. A two-component developer 8 containing at least toner and carrier stored in a developer reservoir 12 is drawn up by magnetic force and supplied to a developing section adjacent to the photoreceptor drum 6;
Developing is performed by adsorbing toner to the electrostatic latent image formed on the photoreceptor. The developer that has passed through the developing section is transferred to the developing sleeve 1.
A scraper 7 for further stripping is provided in the lower right corner [in the figure] of the developing device housing IO, where the scraper 7 is provided with its tip in contact with the developing sleeve on the opposite side of the developing section on the downstream side of the developing section.
A replenishment toner storage section 9 is provided adjacent to the developer reservoir section 12 with a partition member 11 having appropriate toner permeability interposed therebetween.

Therefore, the developer that passes through the developing section and is conveyed by the developing sleeve 1 is peeled off from the top of the developing sleeve 1 by the scraper 7 and falls into the developer reservoir 12 . The toner stored in the replenishment toner accommodating portion 9 which is in contact with the developer reservoir 12 via the partition member 11 collapses due to minute vibrations caused by the rotation of the developing sleeve 1, and the partition member 1
A small amount of toner leaks out from the gap 1 toward the developer reservoir, and the insufficient toner is absorbed by the carrier, so that the toner concentration in the developer returns to the predetermined value, and the magnetic force forces the developer sleeve again. It is transported to the developing section by l. The amount of toner that can be adsorbed to the carrier is determined by the adsorption force due to contact charging between the two, and since more than a certain amount of toner will not be adsorbed to the carrier, only the insufficient amount of toner will be transferred from the toner storage space 9 to the developer. will be replenished. Partition member 1
As the material 1, a suitable mesh wire gauze, a comb tooth-like protrusion molded integrally with the housing, a 7-piece having a curtain-like gap, etc. can be used. When the toner in the toner storage space 9 runs out, the developing device can be used for a long period of time by filling it with toner using a suitable applicator or the like.

With the above configuration, a small and inexpensive developing device can be obtained.

FIG. 2 is a diagram showing the vicinity of the developing device of an embodiment of a multicolor copying machine in which three developing devices having the above configuration are installed along the photoreceptor belt 6, and the space occupied by the three developing devices is extremely small. can do.

In still another embodiment shown in FIG. 3, there is provided a conventional developing device in which the replenishment toner tank 5 described in FIG. A developing device according to the present invention having a replenishment toner accommodating portion 9 is arranged in parallel in the device housing 10, and is used for black development in, for example, a red and black copying machine.

Suitable for two-color copying machines whose imaging devices are frequently used.

In the embodiment shown in FIG. 5, the developing device is provided in contact with the upper part of the photoreceptor, and the replenishment toner storage section 9 is provided in the upper part of the developing device housing 10. The developer passes through the horizontally provided partition 9 member 11 and falls in an appropriate amount onto the developer 8 in the developer reservoir 12 below. However, the present invention can be applied to various electrostatic printing devices other than copying machines to obtain similar effects.

Effects As described above, according to the present invention, the developing device can be made smaller and cheaper, and as a result, the printing device can be made smaller and the cost can be reduced.

[Brief explanation of the drawing]

The first diagram is a sectional view showing the developing device according to the embodiment of the present invention, and the second diagram is
3 and 3 are sectional views showing the developing device section of other embodiments of the present invention, FIG. 4 is a sectional view showing another embodiment of the developing device of the present invention, and FIG. 5 is a sectional view of a conventional two-component developing device. It is a sectional view showing an example of the configuration of the developing device. developer container) 11
...Partition member 12...Developer storage space Fig. 1 Fig. 2 Fig. 3 Fig. 4

Claims (3)

[Claims] (1) In an electrostatic printing device that develops an electrostatic latent image formed on a photoreceptor by a developing device using a two-component developer containing at least toner and carrier, the developing device includes a developer container and a developer container. A printing device characterized in that a replenishment toner storage space is provided in the container via a developer storage space and a partition member having appropriate toner permeability. (2) The printing apparatus according to claim 1, wherein a plurality of developing devices having the above configuration can be mounted along the photoreceptor. (3) The printing apparatus according to claim 1, wherein the developing device configured as described above and the developing device equipped with a replenishment toner tank can be simultaneously mounted along the photoreceptor.