JPH11133746A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide constitution by which a uniform toner thin layer having specified thickness is stably formed on a toner carrier over a long term and to provide a developing device preventing the leakage of toner with simple constitution. SOLUTION: A toner partition plate 72 for dividing toner is provided between a toner retaining chamber 62 in which the scraped toner is accumulated and a toner storing chamber in which the toner is stored, and is formed to be circular-arc shape adaptively to a toner stirring member. Thus, the constitution by which the uniform toner thin layer having the specified thickness is stably formed on the toner carrier over a long term is provided. The leakage of the toner from the developing device is prevented and cleaning work for the device is facilitated. Then, the developing device capable of realizing easy maintenance is made small in size and light in weight and inexpensive with the simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing method for visualizing an electrostatic latent image on a photoreceptor by using a toner supplied on a toner carrier as a developer layer having a predetermined thickness by a toner layer thickness regulating member. Related to the device.

[0002]

2. Description of the Related Art In a conventional apparatus, generally, a toner carrier is rotatably supported on a housing of a developing device, and a toner layer thickness regulating member is attached to a holding member of a toner layer thickness regulating member attached to the housing. A developing device is known in which a thickness regulating member is opposed to a toner carrier, and a thin toner layer is formed on the toner carrier by the toner layer thickness regulating member. The toner layer thickness regulating member is provided with a friction regulating material such as a rubber plate attached to the tip of a plate-like rubber retaining plate, and the rubber retaining plate is attached to the holding member of the toner layer thickness regulating member so that the friction regulating material carries toner. A holding member of the toner layer thickness regulating member is screwed and attached to a screw hole of the housing so as to come into contact with the body.

Further, as disclosed in JP-A-1-309080, there is disclosed a configuration in which a toner carrier is rotatably supported on a housing by a support shaft, and a toner layer thickness regulating member is positioned on the basis of the support shaft. I have. Further, as disclosed in Japanese Patent Application Laid-Open No. 55-89869, there is disclosed a structure in which means for connecting and supporting the toner carrier and the developer layer thickness regulating means are provided, and their linear expansion coefficients are defined to improve positioning accuracy. Have been.

[0004]

In the above prior art, various measures have been devised for the purpose of accurately positioning the toner carrier and the toner layer thickness regulating member so as to form a thin layer uniformly, and to prevent the toner layer from being removed from the developing device case. Various measures have been taken against toner leakage, but in recent years, further uniformity of image quality has been required for higher image quality and higher definition. for that purpose,
It is required to further improve the performance of the toner carrier and the toner layer thickness regulating member and further improve against toner leakage.

In the prior art, a toner carrier and a toner layer thickness regulating member are fixed to a housing by providing a support plate or the like to form a final form.

A toner seal member for preventing toner leakage is provided between the toner layer thickness regulating member and the housing.

In such a case, a toner holding chamber for storing the scraped toner is provided by using a toner layer thickness regulating member from the toner carrier, but if there is a large amount of scraped toner, the toner When the toner storage chamber for storing the toner is full, and when the storage chamber is full, the operation of the toner scraping member configured to scrape the toner into the toner storage chamber becomes slow, and the toner supply roller In order to supply the toner, the toner supply to the toner storage chamber for storing the toner becomes insufficient, and the toner seal member provided between the toner layer thickness regulating member and the housing for preventing toner leakage is used. In many cases, toner leakage occurred.

SUMMARY OF THE INVENTION An object of the present invention is to provide a structure capable of stably forming a uniform thin toner layer with a predetermined thickness on a toner carrier for a long period of time and to prevent toner leakage with a simple structure. An object of the present invention is to provide a developing device.

[0009]

In order to achieve the above object, a toner as a fine colored powder, a toner carrier and a toner carrier are pressed against the toner carrier to frictionally charge the toner, and the toner is placed on the toner carrier. Rotating the toner layer thickness regulating member forming the thin layer and the toner carrier on which the toner thin layer is formed,
In a developing device that conveys the thin toner layer to a position facing the latent image holding unit on which the electrostatic latent image is formed and visualizes the electrostatic latent image, using a toner layer thickness regulating member from a toner carrier, Preferably, a toner partition plate for separating toner is provided between a toner storage chamber for storing the scraped toner and a toner storage chamber for storing toner for supplying toner to the toner supply roller. Provided a toner partition plate having a plurality of openings through which toner can pass,
This toner partition plate was formed in an arc shape so as to fit into the toner stirring member.

Thus, the toner scraped off from the toner carrier by the toner layer thickness regulating member using the toner layer thickness regulating member is scraped from the plurality of openings provided in the toner partition plate by the toner scraping member. Will be issued. The scraped toner is held on the surface of the toner partition plate,
It does not return to the toner storage chamber where the scraped toner is stored. The toner on the surface of the toner partition plate is supplied to a toner supply roller by a toner stirring member provided in a toner storage chamber for storing toner.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 is a sectional view of a small color image forming apparatus according to the present invention.

This color image forming apparatus is a machine frame (outer frame).
A photosensitive belt 2 serving as a latent image holding means is installed vertically long in a main body constituted by 1, and a transfer drum 6 serving as an intermediate transfer member, a transfer device 12, A medium supply device 10 and a fixing device 14 are arranged, and developing devices 30Y, 30M, 30C, and 30K filled with toners of four different colors are arranged on the right side in the drawing. An exposure device 4 for forming a latent image on the photosensitive belt 2 is disposed below the developing device 30Y, and a paper feed cassette 9 for storing a recording medium is disposed below the exposure device 4.

A transfer device 12, a recording medium peeling device 13, and an intermediate transfer member cleaning device 16 are arranged around the transfer drum 6, and a charging device 3, an afterimage removing device 7, and a photosensitive member cleaning device 8 are arranged around the photosensitive belt 2. Be placed.

The photosensitive belt 2 serving as a latent image holding means is driven in a direction of an arrow 21a by a driving device (not shown).

First, the photosensitive layer on the surface of the driven photosensitive belt 2 is uniformly charged by the charging device 3.

Next, the exposure device 4 exposes the image and character information by a personal computer, an image scanner or the like in dot units, and forms an electrostatic latent image on the photosensitive belt 2.

Thereafter, the electrostatic latent image on the photosensitive belt 2 is visualized as a toner image by being developed by any one of the developing devices 30Y, 30M, 30C and 30K, and is sent to the first transfer position 22a. . The photosensitive belt 2 is supplied with a potential by a power supply (not shown), and the transfer drum 6 is connected to the ground. For this reason, at the first transfer position 22a, the potential difference between the photosensitive belt 2 and the transfer drum 6
The transfer of the toner image to is performed.

After passing through the first transfer position 22a, the photosensitive belt 2 is erased of the electrostatic latent image by light irradiation by the residual image removing device 7, and the surface potential of the photosensitive belt 2 is reduced to a certain level or less.

After that, the remaining toner on the photosensitive belt 2 which is not transferred by the first transfer is removed by the photosensitive member cleaning device 8, and the next toner image can be formed.

The operation of one cycle described above is performed by the transfer drum 6.
Developing devices 30Y and 30Y
By sequentially performing the processes on M, 30C, and 30K, a multicolor toner image in which a single color toner image is superimposed on the transfer drum 6 is formed.

On the other hand, a recording medium such as a sheet, an OHP sheet, etc.
b, and a single or multiple color toner image formed on the transfer drum 6 is transferred to a recording medium by the operation of the transfer device 12.

After the transfer of the toner image to the recording medium, the recording medium is peeled off from the transfer drum 6 by the recording medium peeling device 13, the toner is fused and fixed by the fixing device 14, and the paper is discharged onto the upper surface of the main body by the paper discharging device 15. You.

On the other hand, after the transfer to the recording medium is completed, the residual toner remaining on the transfer drum 6 without being transferred is cleaned by the intermediate transfer body cleaning device 16 so that the next toner image can be superimposed.

By simplifying the transport path from the supply of the recording medium to the discharge of the recording medium as much as possible and by increasing the radius of curvature of the transport path, paper jams during transport can be prevented and reliability can be improved. .

Further, the processing at the time of paper jam can be easily performed. Further, it can correspond to various types of recording media such as cardboard.

In this embodiment, the recording medium conveyance path is arranged in a substantially arc shape, and the transfer drum 6, the photosensitive belt 2, the developing device 30
By arranging the Y, 30M, 30C, 30K, the exposure device 4 and the like inside the recording medium transport path, the space is effectively used, the body is reduced in size, the transport path is simplified, and the printing surface faces downward when the recording medium is discharged. To discharge to

By adopting the above arrangement, the transport path can be simplified, and most of the units are disposed inside the main body relative to the transport path.
, And the transport route is easily opened, so that a paper jam can be easily handled. In addition, discharging the printing surface downward at the time of discharging has an advantage that the printing surface is discharged in a printing order from the printing surface side.

By forming the photoreceptor in a belt-like configuration, the developing devices 30 of a plurality of colors can be arranged in substantially the same shape on the same plane of the photosensitive belt, and the developing devices can be replaced according to the color to be developed. There is no need to change the structure of the developing device for each color or the like, and the size and the price can be reduced.

Further, by arranging the photosensitive belt 2 vertically long, the space occupied by the photosensitive belt having the same circumference can be reduced, so that the size of the main body can be reduced.

When the recording medium is conveyed from the lower part to the upper part of the main body, the transfer drum 6 rotates in the direction of arrow 21c, and the photosensitive belt 2 rotates in the direction of arrow 21a to operate in the forward direction at each contact point. As a result, it is possible to obtain a configuration with good development efficiency and less problems such as vibration.

Further, the transfer drum 6 can be made to follow the photosensitive belt 2 so that the color shift can be reduced. At this time, the toner carrier 3 which is a toner carrier
1 is a reversal developing method in which the photosensitive belt 2 and the toner carrier 31 are rotated in a direction indicated by an arrow 21b (a method in which the photosensitive belt 2 is rotated upward from the lower side) so that the developing efficiency can be reduced. It is possible to obtain a configuration that is good and has few problems such as vibration.

FIGS. 1, 2, 3, 5, and 6 show an embodiment of the developing device 30 according to the present invention. The photosensitive belt 2 is driven upward from below in the direction of arrow 21b, and the toner carrier 31 of the developing device 30 contacts the photosensitive belt 2 or holds a gap of about 0.1 to 0.3, and is driven as shown by arrow 31b. Is done.

The material of the toner carrier 31 is made of a conductive material such as aluminum or stainless steel or a conductive rubber material.
A toner supply roller 32 and a toner layer thickness regulating member 34 are arranged around the toner carrier 31.

The toner layer thickness regulating member 34 is pressed by the pressing means 35 against the toner carrier 31 with an appropriate pressing force. The structure of the pressing means 35 is constituted by a leaf spring made of a thin plate such as stainless steel or phosphor bronze.

The friction regulating member 34 of the toner layer thickness regulating member 34
a is a leaf spring material of the pressing means 35 and a toner layer thickness regulating material 34a.
Alternatively, a rubber plate (urethane rubber, silicon rubber, or the like) may be attached, or the plate spring material of the pressing means 35 may be stretched to directly contact the toner carrier 31.

The toner layer thickness regulating member 34 is fixed to the holding portion 36 a of the holding member 36 by being sandwiched by a pressing plate 37.

Further, on both sides of the holding member 36, support portions 36b of the toner carrier 31 are provided. The toner support shaft 31a is engaged with the opening 36c of the support portion 36b via a bearing 31b. The toner carrier 31 and the toner layer thickness regulating member 34 are integrated by a holding member 36 to form a toner carrier unit 38.

Here, the holding member 36 and the toner carrier 31
The supporting portion 36b is preferably composed of one part, and may be attached by another piece. However, by using one part, errors in assembling can be reduced. Further, the material is desirably made of a metal plate having a minimum difference in order to prevent deformation due to a difference in linear expansion coefficient from the material of the pressing means 35 of the toner layer thickness regulating member 34.

The housing 39 of the developing device 30 is provided with an opening 39b which is detachable from the support portion 39a of the bearing 31b of the toner carrier unit 38. Therefore, the integrated toner carrier unit 38 is configured to be detachable from the housing 39.

Further, the toner carrier unit 38 is configured to be detachable without disassembling the lid and the like of the housing 39.

By inserting the toner carrier unit 38 in the direction of arrow R shown in FIG. 2 and rotating in the direction of arrow S,
As shown in FIG. 1, the toner carrier unit 38 can be mounted on the housing 39.

FIG. 3 is a perspective view showing details of the assembly and configuration of the toner carrier unit 38. As shown in FIG. As described above, the toner layer thickness regulating member 34 is sandwiched by the holding plate 37 in the holding portion 36a of the toner layer thickness regulating member 34 of the holding member 36 and fixed by the screw, and the toner carrier 31 is fixed to the toner carrier support shaft 31a. Of the holding member 3 via the bearing 31b.
6, by being engaged with the support portions 36b on both sides.
A toner carrier unit 38 is configured.

As shown in FIG. 2, the toner carrier unit 38 is inserted in the direction of arrow R with the flat portion of the bearing 31b aligned with the opening 39b of the housing 39.
The support 39 of the housing 39
a and the cylindrical portion of the bearing 31b are engaged with each other, and are finally fixed by fastening the toner carrier unit 31 with screws, so that the developing device 30 is in the final form.

A toner seal member 40 is provided in the housing 39 of the developing device 30 at a position corresponding to the back surface of the toner layer thickness regulating member 34 when the toner carrier unit 38 is attached. The material of the toner seal member 40 is an elastic member such as a foamed sponge or a rubber plate, or a thin sheet.

Further, a toner scraping member 41 is provided to prevent toner stagnation around the toner layer thickness regulating member 34.

The operation of the developing device 30 having the above configuration is as follows.
A toner supply roller 32 rotatably contacting the side of the toner carrier 31 with respect to the toner carrier 31;
The toner T attached to the toner supply roller 32 adheres to the toner carrier 31 and is supplied. On the downstream side, a thin toner layer is formed by the friction regulating member 34a of the toner layer thickness regulating member 34 which is pressurized to a constant pressure by the pressurizing means 35 for applying a contact pressure to the toner carrier 31.

Here, the remaining toner T '(supply surplus) whose layer thickness has been regulated by the toner layer thickness regulating member 34 falls below the layer thickness regulating member 34a, and passes through the toner return opening 61 into the toner holding chamber. Collect at 62.

Thereafter, the excessively supplied toner T 'is removed by the rotatable toner scraping member 41 into the toner scraping port 63.
The toner is further scraped off and accumulated in the toner accumulation chamber A68.

The toner T already accumulated is stored in the toner accumulation chamber A68, the toner accumulation chamber B69, and the toner accumulation chamber C7.
0, a toner agitating member A64, a toner agitating member B65, a toner agitating member C66,
The toner is supplied to the toner supply roller 32 while being stirred by the toner stirring member D67.

FIG. 6 shows a conventional example. The excessively supplied toner T ′ accumulated in the toner holding chamber 62 is removed by the rotatable toner scraping member 41 to remove the toner.
3 and is about to be accumulated in the toner accumulation chamber A68.

At this time, depending on the timing, the toner T 'is agitated by the toner agitating member A64 by the toner T accumulated in the toner accumulating chamber A68 and is pushed back into the toner holding chamber 62. A phenomenon in which the toner is pushed back to the toner return opening 61 occurs, which causes the toner to leak from the toner seal member 40.

In the present invention, the toner storage chamber 62 shown in FIG.
Between the toner feed opening 7 and the toner storage chamber A68.
3 is provided. This allows
Excessive supply of toner T ′ accumulated in the toner storage chamber 62
Is a toner ejection port 63 by the toner ejection member 41.
Partition plate 72 having toner feed opening 73
Is scraped off by the toner partition plate surface 74.

As a result, the toner T 'is held on the toner partition plate surface 74, and the toner T' is supplied to the toner supply roller 32 while being stirred by the toner stirring member A64. Therefore, the toner T that has already been accumulated is not pushed back into the toner storage chamber 62.

Therefore, the excessively supplied toner T 'is scraped out by the toner scraping member 41 and no excess toner T' is accumulated around the toner layer thickness regulating member 34, so that a stable toner thin layer is always formed, and Appropriate charging of the toner becomes possible.

Further, since no extra toner is accumulated in the toner storage chamber 62, it is an effective means for using the toner to the end.

In a printing test of 10,000 sheets using the developing device 30, a long-term stability of a toner layer thickness of 0.42 ± 0.03 mg / cm ² and a toner charge amount of 20 to 30 μC / g was able to be achieved.

Further, since the toner carrier 31 and the toner layer thickness regulating member 34 are integrated by the holding member 36, if the precision of the components of the holding member 36 is controlled to be high, the toner carrier and the toner layer thickness can be controlled. Accurate positioning of the regulating member is possible, stable and uniform formation of a thin toner layer is possible, and image uniformity is improved, and high image quality and high definition can be realized.

Further, by integrating the toner carrier 31 and the toner layer thickness regulating member 34 with the holding member 36,
The positioning of the toner carrier 31 and the toner layer thickness regulating member 34 is determined by the holding member 36, so that high precision is not required for the housing 39 for positioning, and the occurrence of torsion and the like due to mounting errors during assembly is small.

In the prior art, the housing and the toner layer thickness regulating member are positioned by the housing.
Since high precision is required for the housing, an expensive resin that can be molded with high precision must be used, and accurate positioning has been performed using a jig or the like during assembly.

However, in the present embodiment, the necessary and sufficient accuracy can be obtained by using a general resin material, and the assembling time can be shortened because the holding member 36 need only be controlled with high precision as a single component. It was able to achieve a low price.

[0062]

According to the present invention, a structure capable of stably forming a uniform thin toner layer with a predetermined thickness on a toner carrier over a long period of time is provided, and at the same time, leakage of toner from a developing device is prevented. Thus, the developing device which can facilitate the cleaning work of the device and can be easily maintained can be realized with a simple configuration, with a small size, light weight and low cost.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a developing device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a toner carrier unit and a housing of the developing device according to the embodiment of the present invention.

FIG. 3 is a perspective view showing an assembly and configuration of a toner carrier unit and a housing of the developing device according to one embodiment of the present invention.

FIG. 4 is a sectional view of a color image forming apparatus according to one embodiment of the present invention.

FIG. 5 is an enlarged perspective view of a main part of the developing device according to the embodiment of the present invention.

FIG. 6 is a sectional view of a main part of a developing device showing a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Machine frame, 2 ... Photosensitive belt, 3 ... Charging device, 4 ... Exposure device, 6 ... Transfer drum, 7 ... After-image removal device, 8 ... Photoconductor cleaning device, 9 ... Paper cassette, 10 ... Paper feeding device , 12 ...
Transfer device, 13: recording medium peeling device, 14: fixing device, 1
5 paper discharge device, 16 intermediate transfer body cleaning device, 21a, 2
1b, 21c: arrow, 22a: first transfer position, 30, 3
0Y, 30M, 30C, 30K: developing device, 31: toner carrier, 31a: toner carrier support shaft, 31b: bearing,
32: toner supply roller, 34: toner layer thickness regulating member,
34a: friction regulating material, 36: holding member, 36a: holding portion, 36b, 39a: supporting portion, 36c, 39b: opening, 37: holding plate, 38: toner carrier unit, 3
9: Housing, 40: Toner seal member, 41: Toner scraping member, 61: Toner return opening, 62: Toner holding chamber, 63: Toner scraping port, 64: Toner stirring member A, 65: Toner stirring member B, 66 ... toner stirring members C, 67 ... toner stirring members D, 68 ... toner accumulation chambers A, 69 ... toner accumulation chambers B, 70 ... toner accumulation chambers C, 7
1: toner storage chamber D, 72: toner partition plate, 73: toner feed opening, 74: sheet surface

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tadashi Okano 1-1-1 Higashitaga-cho, Hitachi City, Ibaraki Prefecture Inside the Taga Headquarters, Hitachi, Ltd.Electric Equipment Division (72) Inventor Yoshitaro Ishii Higashi Taga, Hitachi City, Ibaraki Prefecture 1-1-1, Machi, Hitachi, Ltd.Electrical Equipment Division, Taga Headquarters (72) Inventor Nobuo Suzuki 1-1-1, Higashitagacho, Hitachi, Ibaraki Prefecture, Hitachi, Ltd.Electrical Equipment Division Taga Division (72) Inventor Masafumi Suzaki 1-1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture Inside the Taga Headquarters, Electrification Equipment Division, Hitachi, Ltd. (72) Inventor Shoji Shokai 1-1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture No. 1 Inside the Taga Headquarters, Hitachi, Ltd.Electrical Equipment Division (72) Inventor Katsumasa Mikami 1-1-1, Higashitagacho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd.Electrical Equipment Division, Taga Headquarters (72) Inventor Shoji Takeya 1-1-1, Higashitagacho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd.Electrical Equipment Division, Taga Headquarters (72) Inventor Katsuyoshi Onose 1-1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture Within the Taga Headquarters, Hitachi, Ltd.Electrical Equipment Division (72) Inventor Shuji Imazeki 7-1-1, Omika-cho, Hitachi City, Hitachi City, Ibaraki Prefecture Hitachi Research, Hitachi, Ltd. In-house (72) Inventor Tohru Miyasaka 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd.Hitachi Laboratory (72) Inventor Masashi Yamamoto 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Co., Ltd. Within Hitachi, Ltd. Hitachi Research Laboratory (72) Inventor Yoshinori Aono 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd. Hitachi Research Laboratory Co., Ltd. (72) Inventor Kazuomi Onishi 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture No. 1 Inside Hitachi, Ltd. Hitachi Research Laboratory (72) Akiko Oikawa Akiko 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Masaru Nakano 502, Kdatemachi, Tsuchiura City, Ibaraki Prefecture, Machinery Research Laboratory, Hitachi, Ltd. (72) Inventor Riki Hiraoka 502 Kandachi-cho, Tsuchiura-city, Ibaraki Pref., Machinery Research Laboratory, Hitachi, Ltd. (72) Inventor Shinichi Hosaka 1-1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture Taga Headquarters, Hitachi, Ltd. (72) Inventor Motoyuki Suzuki 1-1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture Inside the Taga Headquarters, Electrification Equipment Division, Hitachi, Ltd. (72) Yoshikatsu Shinonaga 1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi, Ltd.Electrical Equipment Division Taga Headquarters (72) Inventor Hiroyuki Onodera 1-1-1, Higashitagacho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd.Electrical Equipment Division Taga Headquarters (72) Invention Person Kazuo Shishido 1-chome, Higashitaga-cho, Hitachi City, Ibaraki Prefecture No. 1 Inside the Taga Headquarters, Hitachi, Ltd.Electrical Equipment Division

Claims (5)

[Claims] 1. A toner layer having a fine color powder, a toner carrier, and a toner layer thickness regulation for pressing the toner carrier and frictionally charging the toner and forming a thin toner layer on the toner carrier. The member and the toner carrier on which the thin toner layer is formed are rotated, and the thin toner layer is transported to a position facing the latent image holding unit on which the electrostatic latent image is formed, and the electrostatic latent image is transferred. In a visualization developing device, a toner storage chamber for storing toner scraped off from a toner carrier using a toner layer thickness regulating member, and a toner storage for storing toner for supplying toner to a toner supply roller A developing device provided with a toner partition plate for separating toner between the developing chamber and the chamber. 2. A developing device according to claim 1, wherein said toner partition plate has an opening through which toner can pass. 3. The developing device according to claim 1, wherein a plurality of openings are provided in said toner partition plate. 4. The developing device according to claim 1, wherein said toner partition plate is formed in an arc shape. 5. The developing device according to claim 1, wherein said toner partition plate is formed so as to be adapted to a toner stirring member.