JPS62182769A - Rotary type multicolor developing device - Google Patents

Abstract

PURPOSE:To replenish toners uniformly and to prevent color mixture by constituting an agitating means, which distributes the toner in each toner chamber uniformly in the axial direction of a cylinder body, with a screw which reduces the extent of toner feed per rotation according as going to axial ends. CONSTITUTION:A screw 7B as the agitating means which distributes the toner uniformly in the axial direction of a cylinder body 1 is provided in the vicinity of a partitioning wall upstream in the rotation direction of the cylinder body 1. The turn direction of the screw 7B is reversed in a part corresponding to a toner replenishing hole 2B, and the pitch of the screw 7B is reduced according as going to axial ends. If the pitch of the screw is uniform in the axial direction, the quantity of the replenished toner is different by parts in the axial direction, and the quantity of toner is different in the axial direction to cause the irregularity of picture density.

Description

[Detailed description of the invention] (Technical field) The present invention relates to a rotary multicolor developing device.

(Prior Art) In the field of color electrophotography, a developing device is known that is disposed close to an electrostatic latent image carrier and sequentially supplies several types of toner to the electrostatic latent image to perform multicolor development.

In a conventional developing device of this type, a plurality of developing devices each having a function of developing with toners of different colors sequentially rotate to supply toners of a desired color to an electrostatic latent image to form a color image.

However, in the conventionally known developing device described above.

There is no mechanism for replenishing toner even if each developing device runs out of toner, and the developing device is designed to be disposable once the toner runs out. Therefore, since the toner is not necessarily used evenly in each developing device, there may be unused color toner, which is uneconomical.

For example, as a means of replenishing toner, different colors of 1-toner are used for each development using the same replenishment route! (However, if this is implemented, secondary problems such as color mixing of the toners of each color and toner scattering during replenishment will occur.

(Objective) Accordingly, an object of the present invention is to provide a rotary multicolor developing device that can improve economical efficiency by replenishing toner without causing color mixing.

(Structure) In order to achieve the above object, the present invention includes a cylindrical body provided with a plurality of independent toner chambers formed in one circumferential direction, and a cylindrical body provided for each toner chamber on the circumferential surface of the cylindrical body. It has a toner replenishment port, a means for opening and closing the toner replenishment port, a developing means for supplying toner from each toner chamber to the static ffi latent image, and a stirring means for uniformly distributing the toner in each toner chamber in the axial direction of the cylinder. It is characterized by

A detailed description will be given below based on one embodiment of the present invention.

In the following embodiments, a rotary multicolor developing device for a color electrophotographic copying device that performs development using four-color monocomponent toners will be described.

In FIGS. 1 and 2, reference numeral 1 indicates a rotatable drum-shaped cylindrical body, and four independent chambers 1 to 1B (tc, t+, IY, 1B) are formed inside thereof.

Each of these toner chambers has an extension in the axial direction of the cylinder 1, and its dimensions are as follows:
Corresponds to a longitudinal dimension of 0. Then, cyan is applied to 1 to toner chamber IC, and magenta is applied to toner chamber IM.

It is assumed that yellow toner is stored in the toner chamber IY and black toner is stored in the toner chamber IB.

For example, in the toner chamber IB, a rectangular toner replenishment port 2B is formed at the rightmost end in the axial direction of the cylinder, which corresponds to the circumferential surface of the cylinder 1.
A lid 3B is provided for opening and closing. Lid 3B is cylindrical body 1
It is fitted into a guide groove (not shown) on the inner side of the body and is movable. The lid 3B is driven to open and close by a rack and pinion mechanism driven by a motor or a mechanism using a solenoid. In other words, the lid 3C and the drive mechanism described above are collectively referred to as a toner replenishing port opening/closing means.

The toner supply port 2B is located on the rotational direction of the cylinder 1! - Nurse room I
A developing roller 4 is located near the partition wall downstream of the toner replenishing port 2B in the rotational direction of the cylinder l.
B, a developing means consisting of a sponge roller 5B, a sliding contact member 68, etc. is provided. A portion of the developing roller 4B is exposed from the circumferential surface of the cylindrical body 1, so that it can closely face the photosensitive drum 20 at a desired rotational position of the cylindrical body.

Further, near the partition wall on the upstream side in the rotational direction of the cylinder 1, a screw 7B is provided as a stirring means for uniformly distributing the toner in the axial direction of the cylinder. As shown in FIG. 3, the winding direction of the screw 7B is opposite to that of the toner replenishing port 2B, and the pinch becomes finer toward the end of the shaft.

If the pitch of the screw is the same in the axial direction as shown in FIG. 4, the amount of replenished toner will differ depending on the location in the axial direction. As a result, the amount of toner varies in the axial direction, causing image unevenness. Although this embodiment uses one-component development, two-component development would have an even worse effect.

However, if the pitch of the screw is set so that the closer to both axial ends, that is, the side plate, the smaller the lateral feed amount is, and the closer to the toner supply port 2B, the larger the feed amount, as in this example, the inside of the toner chamber IB can be set. The toner can be evenly distributed. By uniformly and evenly distributing the replenishment toner in the axial direction, it is possible to prevent uneven images.

The above is the main configuration of the toner chamber IB.

The various members described above in the toner chamber 1B are exactly the same in the other toner chambers. Therefore, the symbols indicating the constituent members of each of the other toner chambers are indicated by replacing the letter B with C, M, and Y, without changing the numbers in each symbol for toner chamber IB.

Here, regarding the toner supply ports, they are shifted at a constant interval in the axial direction of reference numeral 1. That is, the toner replenishing port 2C1 is located closer to the center than the toner replenishing port 2B, the toner replenishing port 2M is located further to the left end, and the toner replenishing port 2Y is located to the leftmost end. This misalignment of each toner supply port is caused by the difference between each toner storage chamber 81'l and 8C, which will be described later.

This is to make them correspond to 8M and 8Y, respectively.

On the two diagonal sides of the cylinder body 1, cyan, magenta, yellow,
Contains 4 types of black toner! - A toner container 8 is fixedly placed in the main body of the color electrophotographic apparatus. This l/ner container 8 is arranged in the axial direction of the cylinder l.
) L-ner storage chambers 8B, 8C, 8M, 8'/ and,
Each of these toner storage chambers has one outlet communicating with the toner storage chamber.

For example, as shown in FIG. 2, what is the rotation of the cylinder 1 when the toner supply port 2B matches the toner outlet 80B? At the lJ position, the developing roller 4C faces the photosensitive drum 20 most closely, and develops the electrostatic latent image with cyan toner.

At the same time, M3B is opened and the valve 800B of the outlet 80B is opened to supply the black toner contained in the toner storage chamber 8B to the toner chamber IB. The supplied black toner falls onto the partition wall and the screw 7B, and is transported in the axial direction and uniformly distributed as the screw 7B rotates.

In this way, when the supply of black toner is completed, the valve 800B
is closed, and the lid 3B is also closed. When the development with cyan 1 to toner is completed, the cylinder 1 rotates in the direction of the arrow and stops at a position where the toner supply port 2C coincides with the toner outlet communicating with the toner storage chamber 8C. This stop position is also the position where the developing roller is closest to the photoreceptor drum 20.

The electrostatic latent image is then developed with magenta toner by a developing roller 1. Further, the toner chamber tC is replenished with the cyan toner in the toner storage chamber 8C.

Following the above steps, replenishment and development will be performed for other 1-ners in sequence.

Note that the toner replenishment ports 2B, 2C, 2M, and 2Y are M3B, 3C, 3M, and 1 except when toner replenishment is performed.
The same applies to the valves provided at the toner outlet of each of the 9 toner storage chambers 8B, 8C, 8M, and 8Y, which are tightly closed by 3Y, etc., and are designed to prevent toner from scattering or leaking outside. It is. Further, the sliding contact members 6B, 6C, 6M, and 6Y that are in sliding contact with the developing roller not only triboelectrically charge the toner but also have a sealing function. The sponge rollers 5 [1, 5C, 5M, and 5V have an auxiliary function of attaching toner to each developing roller.

In this manner, in this example, since toner from each independent toner container is supplied to each independent toner chamber through a dedicated toner outlet, color mixing does not occur when toner is replenished.

Further, since the toner container 8 is fixed to the main body of the color electrophotographic apparatus, each toner storage chamber an, ac has one space.

Refilling toner to 8M and 8Y is easy.

Furthermore, since toner replenishment is performed stably and continuously, there is an advantage that the amount of toner stored in each toner chamber at all times can be reduced, and the developing device can be downsized.

(Effects of the Invention) According to the present invention, it is possible to provide a developing device that can uniformly replenish toner with a simple configuration and that does not cause color mixing, which is advantageous.

[Brief explanation of drawings]

FIG. 1 is a perspective view of essential parts of a rotary multicolor developing device according to the present invention, FIG. 2 is a cross-sectional view of the same, and FIG. 3 is a relationship between each screw and each toner replenishment port when the winding direction is reversed. FIG. 4 is a diagram illustrating the distribution of toner replenishment amount when the pitch of the screw is uniform. 1...Cylinder, 2B, 2C, 2M, 2V...
Toner supply port. 3B, 3C, 3M, 3'/... Lid, 4B, 4
C, 4M, 4'/-...-Developing roller, 7B, 7
C, 7M, 7'/...screw.

Claims (1)

[Claims] A developing device that is disposed close to an electrostatic latent image carrier and performs multicolor development by sequentially supplying several types of toner to the electrostatic latent image, comprising a plurality of toners formed in the circumferential direction. A cylindrical body provided with an independent toner chamber, a toner replenishment port provided for each toner chamber on the circumferential surface of the cylindrical body, and means for opening and closing the toner replenishment port;
It has a developing means that supplies toner to the electrostatic latent image from each toner chamber, and a stirring means that evenly distributes the toner in each toner chamber in the axial direction of the cylinder. A rotary multicolor developing device characterized by being constructed with a screw that reduces the amount of toner fed.