JPH10307468A - Developing device and electrophotographic device provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device capable of eliminating the occurrence of filming with toner on a developing roll and further, the fluctuation of the density of an image and an electrophotographic device provided with the developing device. SOLUTION: The developing device is provided with the developing roll 4 which faces a photoreceptor 1 and is constituted in such a manner that a metallic sleeve 2 is fitted to the outer periphery of an elastic roll 3, a magnet roll 5 installed to face the developing roll 4 with a first facing gap and a regulating plate 6 as a developer layer thickness regulating means installed to face the outer periphery of the magnet roll 5. The regulating plate 6 stepwise regulates the thickness of a developer layer formed in such a manner that a toner magnetic powder mixture 11 is attracted to the outer periphery of the magnet roll 5 and the regulated developer layer is brought into contact with the developing roll 4, to be rotated, so that the magnet roll 5 forms a toner layer on the outer periphery of the developing roll 4. Thus, the occurrence of the filming with the toner can be prevented and the fluctuation of the density of the image can be prevented as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus implemented in the form of a copying machine, a printer, a facsimile or the like, and more particularly to developing an electrostatic latent image with a toner layer attached to a developing roll. The present invention relates to a developing device suitable for use in an electrophotographic apparatus.

[0002]

2. Description of the Related Art A developing device in an electrophotographic apparatus includes a two-component developing device in which a two-component developer in which a carrier and a toner are mixed is applied to an electrostatic latent image on a photosensitive member, and a toner which is used alone.
There is a one-component developing device that acts on a latent electrostatic image on a photoconductor as a component developer.

As a one-component developer, there are those using a magnetic toner or a non-magnetic toner. In particular, the latter one-component developing device using a non-magnetic toner does not use a carrier and controls the mixing ratio of the developer. Since there is no need to provide any means, the structure is simple, which is advantageous for miniaturization and weight reduction and cost reduction. Further, there are advantages such as no carrier adhesion to the photoreceptor. Many are used.

A non-magnetic one-component developing apparatus is disclosed in
55-77764, JP-A-61-239266, Japanese Patent Publication 7-
Japanese Patent Publication No. 43546, Japanese Utility Model Publication No. 7-20683, Japanese Patent Publication No. 7-66214
Etc. have been proposed.

Further, in a non-magnetic one-component developing apparatus, a method of covering the outer periphery with a sleeve using a magnet roll and regulating the toner layer thickness with a regulating plate is described in JP-A-62-192772. Japanese Patent Application Laid-Open No. Hei 8-254892 discloses a method of performing contact development using a blade as a means for forming a plurality of developer thin layers on a roll.
No., published in Japanese Unexamined Patent Publication No.

[0006]

However, when a conventional non-magnetic one-component developing apparatus is used to obtain a high-speed and high-definition color image or to apply low-temperature fixing required for power saving. The so-called filming in which a toner fixing layer is formed by the pressure of a blade for forming a thin toner layer on a developing roll occurs, deteriorating image quality and shortening the replacement life of a developing device. there were.

Further, a method in which a magnet roll is used as a transport roll, the outer periphery is covered with a sleeve, and rotation is applied to attach a toner layer to a developing roll, when used at a high speed, ears are formed. There has been a problem that the carrier (magnetic powder) is liable to be scattered or to have a variation in conveyance.

Further, the method of performing non-contact development by providing a gap between the toner layer on the developing roll and the photoreceptor has a problem that the reproducibility of fine halftone images and gradation becomes insufficient. Was.

[0009] A first object of the present invention is to eliminate the above-mentioned problems, and in a developing apparatus in which only a non-magnetic one-component toner acts on a developing roll during development, toner filming occurs. It is another object of the present invention to provide a developing device which does not cause the carrier to be scattered or disturbed during high-speed use.

A second object of the present invention is to provide a developing device which solves insufficient charging and does not cause a change in image density in a non-magnetic one-component developing system.

A third object of the present invention is to provide a developing apparatus which can be applied to an electrophotographic apparatus which performs low-temperature fixing required for power saving.

[0012]

In order to achieve the above-mentioned object, the present invention provides a method for developing an image by contacting a developer layer formed on an outer peripheral surface of a magnet roll with an outer peripheral surface of the developing roll. In a developing device for forming a toner layer on the outer peripheral surface of a roll and applying the toner layer to a photoreceptor to develop an electrostatic latent image, the developing device opposes the photoreceptor and is provided on the outer periphery of an elastic roll. A developing roll formed by fitting a metal sleeve, the magnet roll installed to face the developing roll through a first facing gap, and the magnet roll; And a developer layer thickness regulating means provided so as to face the outer peripheral surface of the magnet roll, wherein the developer layer thickness regulating means adsorbs the toner mixed magnetic powder on the outer peripheral surface of the magnet roll. The thickness of the formed developer layer is regulated step by step, and the magnet roll moves the regulated developer layer in front of the regulated developer layer. Developing Russia - by providing a rotation in contact with Le, said developing b - and forming a layer - the toner on the outer peripheral surface of the Le.

As another feature of the present invention, the developer layer thickness regulating means has at least two regulating plates, and each of the regulating plates has a gap facing the outer peripheral surface of the magnet roll. It is to be installed so as to face each other.

As another feature of the present invention, the developer layer thickness regulating means has two regulating plates, and the first regulating plate has a second opposing surface on the outer peripheral surface of the magnet roll. The second regulating plate is installed so as to be opposed via a gap, and a third regulating plate is provided on the upstream side in the rotation direction of the magnet roll with respect to the first regulating plate.
Are disposed so as to face each other via the facing gap.

Another feature of the present invention is that the second
Is set equal to or larger than the first opposing gap, and the third opposing gap is equal to the second opposing gap or the second opposing gap. The idea is to make it wider.

Further, as another feature of the present invention, the developer layer formed on the outer peripheral surface of the magnet roll is configured to rotate the developing roll at a portion facing the developing roll. And contacting the outer peripheral surface of the developing roll while rotating and moving in the opposite direction.

Further, as another feature of the present invention, the rotational peripheral speed ratio of the magnet roll to the developing roll is set to 1.
That is, it is set within the range of 0 to 3.0.

Further, as another feature of the present invention, each of the regulating plates has a single-edged tip at the end of the regulating plate.
The purpose of the present invention is to regulate the pool amount of the mixed magnetic powder.

Further, as another feature of the present invention, of the two regulating plates, the first regulating plate has a one-edge shape at the tip of the regulating plate, and the second regulating plate has Of the present invention is provided with a single-edged shape, and an outlet for the toner-mixed magnetic powder is provided above the single-edged blade.

Another feature of the present invention is that a bias power supply for applying a DC bias voltage to the developing roll is provided.

Another feature of the present invention is that in an electrophotographic apparatus having a photosensitive member on which an electrostatic latent image is formed, and a developing device for developing and visualizing the electrostatic latent image, the developing device comprises: A developing device according to any one of claims 1 to 9.

According to the present invention, the developing roll formed by fitting a metal sleeve around the outer circumference of the elastic roll faces the photosensitive member. The magnet roll is installed so as to face the developing roll via a first facing gap. The developer layer thickness regulating means is provided so as to face the outer peripheral surface of the magnet roll. Then, the developer layer thickness regulating means regulates the thickness of the developer layer formed by adsorbing the toner mixed magnetic powder on the outer peripheral surface of the magnet roll in a stepwise manner. The magnet roll is
The toner layer is formed on the outer peripheral surface of the developing roll by rotating the regulated developer layer by bringing the developer layer into contact with the developing roll.

Further, the developer layer thickness regulating means has at least two regulating plates, and each regulating plate is provided so as to face the outer peripheral surface of the magnet roll via a facing gap. Further, the developer layer thickness regulating means has two regulating plates, and the first regulating plate is provided so as to face the outer peripheral surface of the magnet roll via a second facing gap, and the second regulating plate is provided with a second regulating plate. The third regulating plate is installed so as to face the first regulating plate on the upstream side in the rotation direction of the magnet roll via a third facing gap.

The second opposing gap is set equal to the first opposing gap or wider than the first opposing gap.
Is set to be equal to or larger than the second opposing gap.

Further, the developer layer formed on the outer peripheral surface of the magnet roll rotates and moves in a direction opposite to the rotational movement direction of the developing roll at a portion facing the developing roll.
It comes into contact with the outer peripheral surface of the developing roll.

The rotational peripheral speed ratio of the magnet roll to the developing roll is set within a range of 1.0 to 3.0.

Each of the regulating plates has a one-edge shape at the tip of the regulating plate to regulate the amount of pooled toner-mixed magnetic powder.

Further, of the two regulating plates, the first regulating plate has a one-edge shape at the tip of the regulating plate, and the second regulating plate has
The tip of the regulating plate has a single-blade shape, and a toner-mixed magnetic powder sweeping port is provided above the single-blade.

Further, a bias power supply for applying a DC bias voltage to the developing roll is provided.

The developing device according to any one of claims 1 to 9 develops and visualizes an electrostatic latent image formed on a photosensitive member of an electrophotographic apparatus.

As a result, it is possible to prevent the occurrence of toner filming, and to prevent the carrier from being scattered or disturbed during high-speed use. Further, it is possible to solve the insufficient charging and prevent the image density from fluctuating.

Further, it is possible to provide a developing device which can be applied to an electrophotographic apparatus which performs low-temperature fixing required for power saving.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the developing device of the present invention will be described with reference to the drawings. (1) First Embodiment FIG. 1 shows a first embodiment of a developing device of the present invention. As shown in FIG. 1, the developing device 7 includes a developing roller 4 facing the photoreceptor 1, a bare magnet roller 5 facing the developing roller 4, and an outer peripheral surface of the magnet roller 5. A regulating plate 6 which is a developer layer thickness regulating means facing the toner hopper 10;
And a DC bias power supply 13 and the like.

The supply blade 9 supplies the non-magnetic one-component toner in the toner hopper 10 to the vicinity of the magnet roll 5. Toner-conveying magnetic powder of a magnetic carrier is arranged around the magnet roll 5, and the supplied toner is mixed with the toner-conveying magnetic powder to form a toner-mixed magnetic powder 11.

On the outer peripheral surface of the magnet roll 5, a magnetic brush containing toner is formed by the magnetic powder in the toner mixed magnetic powder 11, in other words, a developer layer is formed, and a developer layer is formed. Rotates together with the magnet roll 5, and circulates the toner contained in the magnetic brush to guide the toner to the developing roll 4. The amount (height of the magnetic brush) of the toner-mixed magnetic powder 11 conveyed by the magnet roll 5 is regulated stepwise to a predetermined developer layer thickness by a regulating plate 6 which is a developer layer thickness regulating means. You.

The magnet roll 5 rotates so as to contact the outer peripheral surface of the developing roll 4 while moving the magnetic brush in the counter direction (counterclockwise direction in FIG. 1) with respect to the developing roll 4. The toner layer 12 is formed on the outer peripheral surface of the developing roll 4. The toner layer 12 has a charge amount of 5 to 30 .mu.S / g, preferably 10 to 25 .mu.S / g. It is formed so that the amount of adhesion is 0.4 to 1.5 mg / cm ² , preferably 0.6 to 1.2 mg / cm ² .

The rotation (counterclockwise in FIG. 1) of the developing roll 4 causes the toner on the outer peripheral surface of the developing roll 4 to rotate.
The layer 12 is conveyed to a developing unit formed at a position facing the photoconductor 1, and is brought into contact with the outer peripheral surface of the photoconductor 1 on which the electrostatic latent image is formed, and a DC bias voltage is applied to the developing unit to By applying a developing electric field, the electrostatic latent image formed on the surface of the photoconductor 1 is developed to form a toner image.

Developer, that is, toner mixed magnetic powder 11
Is a mixture of a non-magnetic one-component toner and a magnetic powder as described above, and the non-magnetic one-component toner and the magnetic powder are mixed with a first regulating plate 6a and a second regulating plate 6a as a developer layer thickness regulating means. They are mixed by contact with the regulating plate 6b and the developing roll 4, and are charged to opposite polarities by frictional charging.

In this state, by applying an electric field (forward electric field) in a predetermined direction between the developing roll 4 and the photosensitive member 1, the toner layer 12 held by the developing roll 4 is exposed to light. The toner contacts the electrostatic latent image portion on the outer peripheral surface of the body 1 and the toner is transferred to perform development.

The rotation direction (moving direction of the opposing surface) of the developing roller 4 and the photosensitive member 1 may be the same or opposite, but the peripheral speed of the developing roller 4 with respect to the photosensitive member 1 is not limited. The ratio (peripheral speed of developing roll / peripheral speed of photoreceptor) is 2 or less, and preferably, the peripheral speed ratio is 1.2 to 1.8 in the same direction.

The outer circumference of the developing roll 4 is about 20 to 60.
An elastic roller formed by combining a non-magnetic metal sleeve 2 having a thickness of .mu.m with a low-hardness rubber roller (JIS-A, 20 to 40 degrees) on the outer periphery of a non-magnetic metal shaft. The developing roller 4 is formed by loosely fitting the outer periphery of the developing roller 3.

The metal sleeve 2 on the outer peripheral surface of the developing roll 4
Since the rubber roll has a high friction coefficient, it can rotate reliably and integrally with the rubber roll, and can be in close contact with the photosensitive member 1 softly. It becomes.

Accordingly, when the printing speed is high or when the peripheral speed ratio of the developing roll 4 to the photosensitive member 1 is large (1.5 to 3.0.
0), the effect of extending the replacement cycle of the developing roll 4 and the photosensitive member 1 can be obtained. The rubber roll is desirably conductive (for example, 10 ⁷ to 10 ⁸ Ωcm), and it is possible to apply a developing bias to the metal sleeve using the end of the metal shaft.

The parallel gap (first gap: G1) formed between the magnet roll 5 and the developing roll 4 is 0.3 to 2.0 m.
m, preferably 0.5 to 1.0 mm.

The developer layer formed on the outer peripheral surface of the magnet roll 5 is brought into contact with the developing roller 4 while rotating in the counterclockwise direction with respect to the developing roller 4, and the outer periphery of the developing roller 4 is contacted. Only the toner adheres to the surface, and the toner layer 12 is formed.

The toner mixed magnetic powder 11 formed as a developer layer on the outer peripheral surface of the magnet roll 5 has an average particle diameter of 50 to 50.
A magnetic powder of 100 μm and a toner having an average particle diameter of 6 to 12 μm are used.

As the magnetic powder, it is desirable to use an iron powder carrier or a ferrite carrier as used in a two-component developer. As described above, a magnetic brush is formed from the magnetic powder adsorbed on the outer peripheral surface of the magnet roll 5, and the toner mixed magnetic powder 11 composed of the supplied toner, that is, the developer is regulated to a constant layer thickness. After that, it comes into contact with the developing roll 4.

The magnet roll 5 has the same number of magnetic poles of 6 to 24 poles and the magnetic flux density of the magnetic pole portions of 450 to 1000 by multi-pole magnetizing at regular intervals.
The magnet roll 5 magnetized in the Gaussian range is used bare (the outer periphery is not covered with a relatively rotatable non-magnetic sleeve or the like).

FIG. 2 is a sectional view showing a part of the developing device of FIG. 1 in detail. As shown in FIG. 2, a regulating plate 6 serving as a developer layer thickness regulating means is provided above the outer peripheral surface of the magnet roll 5, and a first regulating plate 6a and a second regulating plate 6a forming a second gap G2. And the second regulating plate 6b forming the gap G3 of FIG.
The magnet roll 5 is rotated in the counterclockwise direction so as to regulate the developer layer thickness of the toner mixed magnetic powder 11 held on the outer peripheral surface of the magnet roll 5. I do.

FIG. 3 is a detailed view of the shape of the regulating plate as the developer layer thickness regulating means of FIG. 2, and FIG. 4 is a right side view of the regulating plate. As the material of the regulating plate, a non-magnetic metal is used. For example, in this embodiment, stainless steel is used.

As shown in FIGS. 3 and 4, the first regulating plate 6a and the second regulating plate 6b, which are the developer layer thickness regulating means, have a single edge shape and an angle θ of 20 ° to 70 °. °, preferably 30 ° to 50 °. Further, by providing extra lengths at both ends of the regulating plate outside the developing region and inserting the regulating plate on the casing side of the developing device 7, a sealing property is brought about and the toner mixed magnetic powder 11 is removed. Effective for preventing leakage.

Next, conditions for increasing the toner charge amount on the developing roll 4 and conditions for forming the toner mixed magnetic powder reservoir 8 by the developer layer thickness regulating means will be described.

The relationship between the peripheral speed U1 of the developing roll 4 and the peripheral speed U2 of the magnet roll 5 in the first gap G1 is expressed by U
When 1 ≦ U2, the peripheral speed ratio (magnet roll peripheral speed / developing roll)
It is desirable to set such that the peripheral speed is about 1.0 to 3.0.

First regulating plate 6 as a developer layer thickness regulating means
FIG. 2 shows a case where a fixed amount of toner mixed magnetic powder reservoirs 8a and 8b are stably formed on the front side of the opposing gap between the second regulating plate 6b and the magnet roll 5 in a fixed amount. I have.

The magnet roll 5 has 8 to 16 magnetic poles and a magnetic flux density of 600 to 800 Gauss.

The amount of the toner-mixed magnetic powder reservoir 8a in the second gap G2 is determined by the amount of the toner-mixed magnetic powder 11 adhering to the outer peripheral surface of the magnet roll 5 without forming the toner-mixed magnetic powder reservoir 8a. It is desirable to set the amount in a range of 1.5 to 3 times (toner mixed magnetic powder pool amount / magnet roll adhesion amount).

By setting the peripheral speed ratio in such a range, the toner-mixed magnetic powder reservoir 8a is formed on the side closer to the first regulating plate 6a by the rotation of the magnet roll 5. At the same time, the toner mixed magnetic powder reservoir 8b on the front side of the second regulating plate 8b is also taken into account, and circulating flows are generated at two places, and the frictional action at these two places greatly increases the toner charge amount. Is effective.

Further, when such a toner-mixed magnetic powder reservoir 8 is formed, an effect of eliminating the adhesion of the magnetic powder to the developing roll 4 can be obtained. This is because in the toner mixed magnetic powder reservoir 8a, a magnetic force acts on the toner mixed magnetic powder 11 to form a loop and the binding force is strengthened so that the magnetic powder is not detached. There is no sticking.

The toner-mixed magnetic powder 11 adsorbed on the magnet roll 5, that is, the layer thickness of the developer is adjusted by the first regulating plate 6a and the second regulating plate 6b which are the developer layer thickness regulating means. In two steps, the pressure can be regulated step by step, the compression resistance and the impact load can be reduced by dispersing, and the magnetic powder can be prevented from adhering to the developing roll 4.

Next, a gap (second gap: G) between the magnet roll 5 and the first regulating plate 6a as the developer layer thickness regulating means.
2) and a gap between the second regulating plate 6b (third gap: G
The conditions for increasing the toner charge amount when 3) is changed and the conditions for forming the toner mixed magnetic powder reservoir 8 will be described.

The form of the toner mixed magnetic powder reservoirs 8a and 8b is shown in FIG. 2 when the peripheral speed ratio of the magnet roll 5 is changed.
Is the same as

In order to achieve the condition for increasing the toner charge amount, the gap (second gap: G2) between the magnet roll 5 and the first regulating plate 6a must be larger than the first gap G1. , 0.1
It is desirable to set the width wider by about 0.3 mm.

The gap (third gap: G3) of the second regulating plate 6b is 0.1 to 0.5 with respect to the second gap G2.
It is desirable to set it wider by mm. (G1 <G2 <
G3) Thus, the second gap G is based on the first gap G1.
By setting the second gap G3 and the third gap G3, the form of the toner-mixed magnetic powder pool 8 is the same as that when the peripheral speed ratio is changed, and the toner-mixed magnetic powder pool is formed. This has the effect of increasing the toner charge. Further, the effect of preventing the magnetic powder from adhering to the developing roll 4 can be obtained similarly.

When the toner concentration of the toner-mixed magnetic powder 11 is set to a low value, the toner-mixed magnetic powder reservoir 8 can be easily and stably formed, and the magnetic force of the toner-mixed magnetic powder 11 is increased and the binding force is increased. Become stronger and do not detach. Further, by regulating the toner in a stepwise manner with the regulating plate 6 as the developer layer thickness regulating means, the frictional effect on the toner increases and the toner charge increases, which is effective in preventing fogging.

As described above, since the developing characteristic for attaching a desired amount of toner to the electrostatic latent image on the outer peripheral surface of the photosensitive member 1 can be secured, the developing roll 4 can be used even in long-term printing. There is no occurrence of toner filming on the outer peripheral surface, and the image density does not decrease or fluctuate.

(2) Second Embodiment FIG. 5 shows a developing device according to a second embodiment of the present invention. The difference of the second embodiment from the first embodiment is that the number of regulating plates 6 serving as a developer layer thickness regulating means is increased.

That is, as shown in FIG. 5, a plurality of (three or more) regulating plates 6 as developer layer thickness regulating means are provided for the magnet roll 5, and the first regulating plate 6a is provided. , Second
The opposing gaps between the second regulating plate 6b and the third regulating plate 6c are G2, G
3 and G4, a first toner mixed magnetic powder reservoir 8 on the front side of the portion opposite to the magnet roll 5 and each regulation plate.
a, second toner mixed magnetic powder reservoir 8b, third toner
The point is that the mixed magnetic powder reservoir 8c is formed, and the thickness of the developer layer is further regulated stepwise.

In order to increase the toner charge amount on the outer peripheral surface of the developing roll 4, the developer is attracted onto the magnet roll 5 in a stepwise manner by regulating the thickness of the developer layer as in the first embodiment. The difference is that the toner mixed magnetic powder 11 is regulated, but the difference is that the opposing gap between the magnet roll 5 and the third regulating plate 6c (fourth gap: G
4) has increased. The relationship is the third regulation plate 6
b (third gap: G3), the fourth gap G
No. 4 is to set the width wider by 0.1 to 0.5 mm (G4 to G3). (G1 <G2 <G3 <G4) In such a configuration, the toner regulating magnetic powder 11 adsorbed on the outer periphery of the magnet roll 5 is controlled by the first regulating plate using means for regulating the layer thickness stepwise. A first toner mixed magnetic powder reservoir 8a, a second toner mixed magnetic powder reservoir 8b, and a third toner mixed are provided on the front side of the second regulating plate 6a, the second regulating plate 6b, and the third regulating plate 6c, respectively. The magnetic powder reservoir 8c is formed.

The relationship between the gap between the magnet roll 5 and the regulating plate 6 as the developer layer thickness regulating means indicates that the amount of the first toner mixed magnetic powder reservoir 8a in the second gap G2 is equal to the toner. The amount of the toner mixed magnetic powder 11 adhering to the outer peripheral surface of the magnet roll 5 without forming the mixed magnetic powder pool is 1.
It is set to 5 to 2 times (toner-mixed magnetic powder pool amount / magnet roll adhering amount), and the amount of the second toner-mixed magnetic powder pool 8b in the third gap G3 is equal to the second gap G2. It is desirable to set the amount of the toner mixed magnetic powder to 1.1 to 2 times.

(3) Third Embodiment FIG. 6 shows a developing device according to a third embodiment of the present invention. As shown in FIG. 6, in the third embodiment, toner mixing restricted between a first restriction plate 6a and a sweep-out restriction plate 6b 'having a discharge port formed in a second restriction plate 6b. When the amount of the magnetic powder reservoir 8b 'has grown to a certain value or more, a certain amount or more is discharged (F direction) to a position just before the magnet roll 5 from a discharge port provided in the discharge port regulating plate 6b', and the toner is discharged. It is characterized in that the pooled amount of the mixed magnetic powder is limited and an appropriate amount is always maintained.

FIG. 7 is a detailed view of the shape of the sweep-out regulating plate 6b ′ of FIG. 6, and FIG. 8 is a detailed cross-sectional view taken along the line AA ′ of FIG. As the material of the sweep-out regulating plate 6b ', stainless steel is used similarly to the respective regulating plates of the first and second embodiments.

As shown in FIG. 7 and FIG.
The tip of b 'has a single-edged shape, and the angle of the blade is 20 ° to 70 °
It is desirable to set the angle to 30 ° to 50 °. Also,
A sweeping port is provided in the upper part of the single blade, and the conditions of the opening of the sweeping port W1 and the discharge side port W2 are as follows.
It is desirable that the discharge side port W2 be narrow. (W1> W
2) The relationship of the peripheral speed ratio between the magnet roll 5 and the developing roll 4 is equal to or higher than that of the first and second embodiments (1.0 to 3.0). Set.

Further, the magnet roll 5 and the first regulating plate 6a,
The gap facing the sweep-out regulating plate 6b 'is equal to or larger than that of the first embodiment (G2-G1 = 0.1 to 0.3, G
By setting 3-G2 = 0.1-0.5), the amount of the toner-mixed magnetic powder reservoir 8b 'can be limited to an optimum value.

In the developing device 7 having such a configuration, the toner-mixed magnetic powder reservoir 8b 'can be easily limited to an appropriate amount, and the conditions of the second gap G2 and the third gap G3 (G2 < G3), and the allowable range of the setting error with respect to the set values of the peripheral speed condition (U1 ≦ U2) of the developing roll 4 and the magnet roll 5 is widened and relaxed.

Further, the toner-mixed magnetic powder reservoir 8b 'is easily formed by the magnet roll 5 and the developer layer thickness regulating means, and a circulation action for circulating the toner-mixed magnetic powder 11 is performed.
In addition, since the layer thickness of the developer is regulated stepwise by the first regulating plate 6a and the sweep-out regulating plate 6b ', the contact area increases, the friction effect increases, the toner charge increases, and the developing roll increases. 4
And a stable toner charge amount on the outer peripheral surface of the substrate can be realized.

[0076]

According to the present invention, a toner having a low-temperature fixing property is provided.
In non-magnetic one-component toner development using
The occurrence of toner filming on the outer peripheral surface of the toner can be prevented for a long period of time, and a high-quality image can be obtained.

Accordingly, the non-magnetic one-component toner according to the present invention
In a high-speed electrophotographic apparatus using a developing device for performing development, a change in image density can be prevented, so that a clear image can be stably secured.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of a schematic configuration of a developing device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a part of the developing device of FIG. 1 in detail;

FIG. 3 is a detailed view of a shape of a regulating plate of a developer layer thickness regulating unit in FIG. 2;

FIG. 4 is a side view of the regulating plate of FIG. 3;

FIG. 5 is a vertical sectional side view of a schematic configuration of a developing device according to a second embodiment of the present invention.

FIG. 6 is a vertical sectional side view of a schematic configuration of a developing device according to a third embodiment of the present invention.

FIG. 7 is a detailed view of a shape of a regulating plate of the developer layer thickness regulating means of FIG. 6;

FIG. 8 is a detailed sectional view taken along the line A-A ′ of FIG. 7;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photoreceptor, 2 ... Metal sleeve, 3 ... Elastic roll, 4 ...
Developing roll, 5: magnet roll, 6: regulating plate, 6a: first
6b... Second regulating plate, 6c... Third regulating plate,
6b ': sweep-out regulating plate, 7: developing device, 8, 8a, 8
b, 8c, 8b ': toner mixed magnetic powder reservoir, 9: supply blade, 10: toner hopper, 11: toner mixed magnetic powder, 12: toner layer, 13: DC bias power supply

Claims (10)

[Claims] A developer layer formed on the outer peripheral surface of the magnet roll is brought into contact with the outer peripheral surface of the developing roll to form a toner layer on the outer peripheral surface of the developing roll; A developing device for developing an electrostatic latent image by applying a layer to a photoreceptor, wherein the developing roller comprises a metal sleeve fitted on an outer periphery of an elastic roll facing the photoreceptor; And the developing roller
And a developer layer thickness control means provided to face the outer peripheral surface of the magnet roll, the magnet roll being provided to face the roller with a first facing gap therebetween. The developer layer thickness regulating means includes a toner roller on an outer peripheral surface of the magnet roll.
The thickness of the developer layer formed by adsorbing the mixed magnetic powder is regulated in a stepwise manner, and the magnet roll contacts the regulated developer layer with the development roll to give rotation. Wherein the toner layer is formed on the outer peripheral surface of the developing roll. 2. The developer layer thickness regulating means according to claim 1, wherein said developer layer thickness regulating means has at least two regulating plates, each of said regulating plates being opposed to an outer peripheral surface of said magnet roll via a facing gap. A developing device, wherein the developing device is installed. 3. The developer layer thickness regulating means according to claim 1, wherein said developer layer thickness regulating means has two regulating plates, and said first regulating plate is provided with a second regulating plate on an outer peripheral surface of said magnet roll. The second regulating plate is installed so as to face through the facing gap, and
The developing device is provided so as to face the regulating plate on the upstream side in the rotation direction of the magnet roll via a third facing gap. 4. The device according to claim 3, wherein the second opposing gap is set to be equal to or larger than the first opposing gap, and the third opposing gap is set to be the second opposing gap. The developing device is set to be equal to or wider than the second opposing gap. 5. A developing device according to claim 1, wherein said developer layer formed on the outer peripheral surface of said magnet roll is opposed to said developing roll in a direction of rotation of said developing roll. A developing device contacting the outer peripheral surface of the developing roll while rotating in the opposite direction. 6. A developing device according to claim 1, wherein a rotational peripheral speed ratio of said magnet roll to said developing roll is set within a range of 1.0 to 3.0. 7. A developing device according to claim 1, wherein each of said regulating plates has a tip of said regulating plate having a single-blade shape to regulate a pool amount of said toner-mixed magnetic powder. . 8. The method according to claim 1, wherein
Of the two regulating plates, the first regulating plate has a one-edge shape at the tip of the regulating plate, and the second regulating plate has a one-edge shape at the tip of the regulating plate, and has Toner
A developing device characterized by providing an outlet for discharging the mixed magnetic powder. 9. The developing device according to claim 1, further comprising a bias power supply for applying a DC bias voltage to said developing roll. 10. An electrophotographic apparatus comprising: a photoreceptor on which an electrostatic latent image is formed; and a developing device for developing and visualizing the electrostatic latent image, wherein the developing device comprises: Any one
An electrophotographic apparatus, wherein the electrophotographic apparatus is the developing apparatus according to any one of the preceding claims.