JPS59231549A - Developing method - Google Patents

Abstract

PURPOSE:To form an image having stable image quality with good fidelity in a developing method of an electrostatic latent image using a one-component type nonmagnetic toner by using a toner compounded with specific fine silica powder. CONSTITUTION:A layer of an insulating nonmagnetic toner 5 is formed on a toner carrying body 2 disposed apart at a prescribed space from an electrostatic latent image holding body 1 more thinly than said space by a coating means 4 (a symbol 3 denotes a hopper and 6 a biasing power source for development) and the electrostatic latent image on the body 1 is developed by transferring selectively the toner onto said body. The insulating nonmagnetic toner compounded with about 0.01-20wt% the fine powder obtd. by treating the fine silica powder formed by vapor phase oxidation of a silicon halide compd. with a titanate coupling agent (e.g.; isopropyltriisostearoyl titanate) is used in the above- mentioned method.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for developing an electrostatic image formed on the surface of an electrostatic image carrier, and particularly a method for developing an electrostatic image formed by forming a thin and uniform layer of insulating non-magnetic toner on a toner carrier. It's about how to do it.

Various developing methods are known for visualizing electrostatic latent images using toner, and they can be broadly classified into dry developing methods and wet developing methods. The former method is further divided into a method using a two-component developer and a method using a -component developer. There are various methods that belong to the two-component developing method, but all of them are excellent methods that can obtain good images relatively stably. They have common drawbacks associated with two-component developers.

The method of using a one-component developer consisting of Toner Only 9 avoids the disadvantages associated with the method of using a more two-component developer described above, and includes a method of development using a -component magnetic toner and a method using a one-component non-component developer. There is a developing method using magnetic toner. Among these, developing methods using -component magnetic toner contain a large amount of magnetic powder in the magnetic toner particles, so they are not only more expensive than non-magnetic toners, but also produce beautiful colors. It was difficult to adapt.

The present invention relates to a developing method using a -component insulating non-magnetic toner rather than a -component magnetic toner which has the drawbacks mentioned above.

Conventionally, the following methods are known as developing methods using component-based nonmagnetic toners.

A movable toner carrier carrying and conveying toner and supplying the toner to the latent image carrier, a toner replenishing means, and a movable application means receiving toner from the toner replenishing means and applying the toner to the movable toner carrier. , a movable applicator having a fiber brush carrying toner on its surface, which contacts the movable toner carrier and moves in the same direction as the movable toner carrier and at a higher speed than the movable toner carrier at this contact portion; a developing method comprising means for uniformly applying toner to the surface of the movable toner carrier using the movable applying means and developing the applied layer by bringing the applied layer close to the electrostatic latent image area; A rotatable magnetic roller that attracts a magnetic carrier to form a magnetic brush for charging magnetic toner particles, and a rotatable magnetic roller that transfers the toner particles from the roller and develops an electrostatic image on an electrostatic image carrier. It has a toner carrier in the form of a developing roller, and maintains a gap between the electrostatic image holder and the developing roller in the developing section, and the gap length is set to be larger than the thickness of the toner coating layer on the developing roller. A developing method for developing an electrostatic image, and an electrostatic image development method for developing an electrostatic image on the surface of an electrostatic image holder by placing a toner carrier carrying toner on its surface facing the electrostatic image holder. In this method, when the toner under the toner carrier stored in the toner storage means is pumped up onto the toner carrier, vibration is applied to only the pumped up portion of the toner to activate it, and a predetermined thickness is applied to the surface of the toner carrier. There is a developing method in which a single layer of toner is formed and then subjected to development. However, in the method of developing these insulating non-magnetic toners by supporting them on a toner carrier using non-magnetic force in the developing section, the force that causes the non-magnetic toner to be supported on the toner carrier in the vicinity of the developing section is mainly electrostatic attraction. If physical adhesion (adhesive force between the toner and the carrier and toner particles, and Van der Waal's adhesion between the toner particles and the surface of the carrier) is dominant, the adhesive force and electrostatic force will cause the adhesive force to form on the carrier. This method has various disadvantages compared to the conventional developing method using insulating magnetic toner to support the toner. For example, a phenomenon occurs that many toners are not applied relatively thinly and uniformly on the carrier. Furthermore, for example, a so-called soil build-up occurs in which toner adheres to non-image areas even though the toner is applied relatively uniformly. Furthermore, even though the toner is applied thinly and uniformly, the amount of toner adhering to the image area is insufficient, resulting in an image with low density. Additionally, many toners produce very poor images with low fidelity and low resolution even though they are applied thinly and evenly. Furthermore, repeated use of more toner results in decreased image density and lower quality images. Furthermore, many toners have the disadvantage that they sometimes cause a decrease in image density and sometimes cause blurring when exposed to environmental changes such as high temperature and high humidity, low temperature and low humidity. .

An object of the present invention is to provide a new developing method using an insulating non-magnetic toner, which improves the above-mentioned drawbacks. That is, an object of the present invention is to provide a developing method with high fidelity and stable image quality. A further object of the present invention is to provide a developing method that eliminates the blurring phenomenon and provides a high-resolution image that is uniform and has sufficient density in the image area.

Another object of the present invention is to provide a developing method with excellent durability such as continuous use characteristics.

Another object of the present invention is to provide a developing method that is stable against environmental changes such as high temperature and high humidity, and low temperature and low humidity.

Another object of the present invention is to provide a developing method that provides images with sharp hues.

The present inventors investigated various developing methods using conventionally known non-magnetic toner, and found that in order to solve the above-mentioned drawbacks, compared to the developing method using magnetic toner, toner is used in the developing section. It has been found that more precise control of the amount of electrostatic charge possessed by the toner on the carrier is required. For example, if the amount of charge is low, a phenomenon occurs in which the toner is not evenly applied onto the carrier, and development cannot be achieved. Next, raise the charge cover and even if you create a condition where -Km is distributed evenly,
If the value is not appropriate, the soil strength will be poor.9 Conversely, if the value is too high, the electrostatic attraction between the toner and the toner carrier will be too strong, making it difficult for the toner to transfer to the electrostatic image carrier. ,
As a result, image density decreases and a low-quality image appears. Furthermore, for the same reason, these developing methods have an extremely large effect on the image due to changes in the toner charge amount during repeated use or environmental changes, and ensuring the stability of the charge amount is more important than ever. In these development methods, the physical adhesion between the toner and the toner carrier clearly affects the transfer of the toner from the toner carrier. It has been found that it is extremely important to prevent an increase in physical adhesion, as when the packing density of toner particles in the toner particles is high, the image density becomes low, resulting in a low-quality image with low resolution. The present invention solves these characteristic requirements due to the method of developing an insulating non-magnetic toner by supporting it on a carrier by non-magnetic force in a developing section by using a toner containing specific silica fine powder. This is something that can be achieved.

That is, the characteristics of the developing method according to the present invention are as follows.
An electrostatic image carrier that holds an electrostatic image on its surface and a toner carrier that carries an insulating non-magnetic toner on its surface are arranged with a certain gap in the developing section, and are treated with a titanate coupling agent. A developing method includes supporting a non-magnetic toner containing fine silica powder on a toner carrier to a thickness thinner than the gap, and transferring the toner to the electrostatic image carrier in a developing section for development. .

In the present invention, if necessary, alternating current and/or direct current bias may be applied between the toner carrier and the electrostatic image holder in the developing section to effect transfer.

The silica fine powder used in the present invention is so-called dry process silica or heated silica produced by vapor phase oxidation of a silicon halide compound, and is produced by a conventionally known technique. For example, it is a method that utilizes the thermal decomposition oxidation reaction of silicon tetrachloride gas in an oxyhydrogen flame, and the basic reaction formula is as follows.

5iCJ, +2H2+02-+SiO2+4HCJ,
In this manufacturing process, for example, aluminum chloride or
By using another metal halide compound such as titanium chloride together with a silicon halide compound, it is also possible to obtain a composite fine powder of silica and other metal oxides, and these are also included. The particle size is 0.001 as the average primary particle size.
It is desirable that it is within the range of ~2μ, particularly preferably,
It is preferable to use silica fine powder within the range of 0.002 to 0.2μ.

Examples of commercially available silica fine powders include those available under the following trade names.

00 80 T600 0X80 0X170 0K84 Cab-0-8i! M-5 (CABOT) MS-7 5-75 8-5 H-5 Wacker HDK N20 (WACKER-V15 40 D-CFlne 5ilica (Dow Corning) Fran J (Francl J) Conventionally, these silica fine powders have been added to toner. Examples of adding silica are known.However, such substances are not necessarily sufficient in terms of stability, and in toners that require positive charge controllability, the addition of such silica changes the chargeability. However, the present inventors found that by incorporating such fine silica powder treated with a titanate coupling agent into the developing side, it was possible to stabilize the amount of triboelectric charge of the developer. They found that the treated silica fine powder is effective in controlling I found it particularly desirable.

A proposal to use a titanate-based force and a pulling agent in toner is given in Karikai No. 55-26519, 55-280.
There are methods described in Specification No. 19, Specification No. 56-51755, etc., but these are basically proposals for the purpose of improving the dispersibility and affinity of the magnetic material for the resin in magnetic toner, and it is true that the dispersibility is improved. However, in such a method, the titanate-based cutting agent has no effect on the charging characteristics of the developer, which is different from the technical content and idea of the present invention.

The titanate coupling agent used in the present invention is an organic titanium compound that can react or adsorb with the hydroxyl group or adsorbed water on the surface of the silica fine powder and form a film on the surface of the silica fine powder, for example, It is as follows.

These may be used alone or in a mixed system of two or more.

The method of treating the fine silica powder with a titanate-based force or f-ring agent is such that the titanium-based coupling agent used in the present invention easily interacts with the chemically or physically bound water present on the surface of the fine silica powder. Because it undergoes a chemical reaction and is coated, a wide range of treatment methods can be used, including both dry and wet methods. For example, fine silica powder and an appropriate amount of titanium-based coupling agent are put into a mixer such as a Henschel mixer or a ball mill, and the titanium-based coupling agent is dry-mixed, or after the titanium-based coupling agent is dissolved in an appropriate solvent, Various methods can be used, such as adding fine silica powder, mixing, and removing the solvent.

The amount of the titanate coupling agent treated with respect to the silica fine powder is preferably 0.01 to 20% by weight, particularly preferably 0.1 to 10% by weight. In addition to the above titanate coupling agent, it is also preferable to use a known silanka or f-ring agent in combination.

In addition, the applied amount of these treated silica fine powders exhibits an effect when it is added in an amount of 0.01 to 20% by weight based on the weight of the developer, and particularly when it is added in an amount of 0.1 to 3% by weight, excellent results are obtained. Shows stable positive chargeability. Regarding the preferred form of addition, it is preferable that 0.01 to 3 weight of treated silica fine powder be attached to the surface of the toner particles based on the weight of the 5' developer.

As the binder resin for toner used in the developing method of the present invention, various material resins conventionally known as toner binder resins for electrophotography are used.

For example, styrenic copolymers such as polynutyrene, polystyrene/butadiene copolymer, styrene/acrylic copolymer, polyethylene, polyethylene vinyl acetate copolymer,
These include ethylene copolymers such as polyethylene vinyl alcohol copolymers, phenolic resins, epoxy resins, allyl 7-thalerate resins, polyamide resins, polyester resins, maleic acid resins, and the like. Furthermore, there are no particular restrictions on the manufacturing method of any of the resins. This is because conventional resins produced by emulsion polymerization or the like tend to contain impurities and are difficult to use, but the present invention allows them to be easily used, and the range of resin selection is greatly expanded. This is also a great effect of the present invention.

As the coloring material used in the toner, conventionally known coloring materials such as carbon f-lac, dyes, pigments, etc. can be used, and all the conventionally known dyes as positive charge control agents can be mixed with the treated silica fine powder used in the present invention. Can be used in combination.

Hereinafter, the present invention will be explained in detail based on embodiments using figures.

FIG. 1 shows an example of a developing device for carrying out an electrostatic latent image developing method using insulating non-magnetic toner. In the figure, 1 is a cylindrical electrostatic image carrier, 2 is a toner carrier, 3 is a hopper which is a toner supply means, 4 is a coating means, and 51d is an insulating non-magnetic toner specified in the present invention.

For example, an electrostatic Vh image is formed on the electrostatic image carrier 1 by a known electrophotographic method such as the Carlson method or the NP method, and the insulating non-magnetic toner 5 in the hopper 3 is transferred to the developer onto the toner carrier 2. The toner 5 is developed using a toner 5 applied by a coating means 4 that controls the thickness of the layer. The toner carrier 2 is a cylindrical developing row 2 made of stainless steel. Aluminum may be used as the material for this developing roller,
Other metals may also be used. Alternatively, a metal roller coated with resin or the like may be used in order to frictionally charge the toner to a desired polarity. Additionally, the developer roller may be made of an electrically conductive non-metallic material.

At both ends of this toner carrier 2,
However, a spacer made of high-density polyethylene is inserted into this shaft. Add this 7 rollers to the electrostatic image holder 1
By fixing the developing device against both ends of the toner carrier 2, the distance between the electrostatic image holder 1 and the toner carrier 2 is reduced
The thickness of the toner layer applied to ± is set and maintained. This spacing is, for example, 100μ to 500μ, preferably 150μ to 300μ. If this distance is too large, the electrostatic latent image on the electrostatic image carrier 1 will cause the toner carrier 2J to:
The electrostatic force exerted on the non-magnetic toner applied to the
The image quality deteriorates, and it becomes difficult to visualize fine lines through development. Furthermore, if this distance is too narrow, there is a great risk that the toner applied on the toner carrier 2 will be compressed and aggregated between the toner carrier 2 and the electrostatic image carrier 1. Reference numeral 6 denotes a developing bias power source, which is capable of applying a voltage between the conductive toner carrier 2 and the back electrode of the electrostatic image holder 1. This developing bias voltage is, for example,
The developing bias voltage is as described in No. 2108.

FIG. 2 shows another example of the developing device. In the same figure, 11
12 is an electrostatic image carrier, 12 is a toner carrier, 13 is a hopper, 14 is an insulating non-magnetic toner specified in the present invention, 15 is a toner storage section, and 16 is a toner supply member. Storage part 1
A vibrating member 17 is used to vibrate the toner 14 in the toner 5.
A vibration generating means 18 is provided at the bottom of the hopper 13.

19 is a cleaning blade. In this developing device, the vibration generating means 18 vibrates the vibrating member 17 at an appropriate amplitude and frequency to form a uniform toner coating layer on the toner carrier 12 which is rotating at a constant speed. The electrostatic image carrier 11 is placed in opposition with a gap larger than the thickness of the toner coating layer, and the non-magnetic toner is flown onto the electrostatic image to develop it. The vibration of the vibrating member 17 may be at any level as long as it does not cause liquid to flow directly onto the toner carrier 12, but it is preferable to control the frequency and amplitude so that the toner coating layer has a uniform thickness of about 5 to 100 μm. .

It is also possible to apply an AC and/or DC developing bias voltage between the toner carrier 12 and the electrostatic image holder 11.

FIG. 3 shows yet another example of the developing device. In the same figure, 21
2 is an electrostatic image carrier, 22 is a toner carrier, 23 is a toner supply section, 24 is an insulating non-magnetic toner specified in the present invention, 2
5 is a coating roller, 26 is a fiber brush fixed to the surface of the coating roller, 27 is a toner cleaning member, 28 is a developing bias power source, and 29 is a coating bias power source.

The application row 225 contacts the toner carrier 22 and rotates in the same direction as the toner carrier 22 at the contact portion. The application row 225 rotates, and the brush 26 applies
24 is conveyed, the toner carrier 22 is uniformly coated with the toner carrier 22, and the electrostatic image is flown onto the electrostatic image holder 21 to be developed. The gap between the toner carrier 22 and the application roller 25 is adjusted so as to form a uniform layer of toner on the toner carrier 22 with a thickness of about 5 to 100 μm. A bias voltage may be applied by a bias power supply 29 for uniform toner application. The gap between the electrostatic image carrier 21 and the toner carrier 22 may be made larger than the thickness of the toner, and a developing bias may be applied by a bias power supply 28 during development.

FIG. 4 shows another example of the developing device. In the figure, 31 is an electrostatic image holder, 32 is a toner carrier, 33 is a developing device main body,
34 is F! specified in the present invention. magnetic-component non-magnetic toner,
35 indicates a magnetic roller. The magnetic row 235 is constituted by a non-magnetic sleeve 36 and a magnet 37 provided therein, forming a magnetic plan 38 thereon. In this developing device, a magnetic carrier is magnetically held on a non-magnetic sleeve 36 to form a brush, and by rotating the Nureap 36, the toner 34 is drawn up by the carrier brush and applied to the toner carrier 32 by contact. In particular, it forms a uniform layer of toner. At this time, since the carrier is held on the magnetic roller 35 by magnetic force, it does not move onto the toner carrier 32. Next, the toner carrier 3
2 and onto the electrostatic image holder 31 for flying development. The gap between the magnetic roller 35 and the toner carrier 32 is
Adjust so that the thickness of the upper toner layer is approximately 5 to 100 μm. The gap between the toner carrier 32 and the electrostatic image holder 31 is made larger than the thickness of the toner, and if necessary, a bias voltage may be applied by a developing bias power source 39.

FIG. 5 shows yet another example of the developing device. In the same figure, 41
4 is an electrostatic image carrier; 42 is a sleeve-shaped toner carrier; 4 is a sleeve-shaped toner carrier;
3 is a fixed magnet disposed within the toner carrier, 44 is a hopper, 45 is a one-component non-magnetic toner specified in the present invention,
46 is a toner thickness regulating blade, and 47 is a developing bias power source. In this developing device, the toner carrier 42
A magnetic plan 48 of the carrier toner mixture is formed thereon, and by rotating the toner carrier 42, the magnetic brush 48 is circulated to collect the toner in the hopper 44.
Then, a thin layer is uniformly coated on the toner carrier 42.

Next, the toner carrier 42 and the electrostatic image carrier 41 are opposed to each other with a gap larger than the thickness of one toner layer, and the one-component non-magnetic toner 45 on the toner carrier 42 is transferred onto the electrostatic charge image on the electrostatic image carrier 41. Perform flying development.

The thickness of one layer of toner is controlled by the size of the magnetic brush 48, that is, the amount of carrier, and the regulating blade 46.

The gap between the electrostatic image holder 41 and the toner carrier 42 is set to be larger than the thickness of the toner. In this case, a developing bias may be applied by the bias power supply 47.

The present invention uses the above-mentioned developing device, and connects an electrostatic image carrier that holds an electrostatic image on its surface and a toner carrier that carries an insulating non-magnetic toner on its surface with a certain gap in the developing section. A non-magnetic toner containing fine silica powder treated with a titanate-based force and a 7° ring agent is supported on a toner carrier to a thin thickness across the gap, and the toner is applied in a developing section. The above object is achieved by transferring the toner to the electrostatic image holder and developing it.

Examples and comparative examples of the present invention will be described below.

Example 1 The above materials were thoroughly mixed in a plengy and then kneaded with two rolls heated to 15F.The kneaded material was left to cool naturally, coarsely pulverized with a cutter mill, and then pulverized with a pulverizer using a jet stream. The toner raw material fine powder having a particle size of 5 to 20 μm was obtained by pulverizing the powder using a wind classifier and further classifying it using an air classifier.

Next, fine silica powder AERO8IL 200 (manufactured by Nippon Aerosil Co., Ltd.) was placed in a closed-type Henschelmie+ sacrificial vessel heated to 70°C, so that the amount of titanium coupling agent was 2.0% by weight based on the silica. Isopropyl triisostearoyl titanate diluted with alcohol was added dropwise to the solution while stirring at high speed. The obtained treated silica fine powder was dried at 120°C.

The treated silica fine powder was added to the above toner raw material fine powder at a rate of 0.
A toner was prepared by adding 6% by weight and mixing with a Henschel mixer.

Meanwhile, a mixture consisting of 100 parts by weight of zinc oxide, 20 parts by weight of styrene-butadiene copolymer, 46 parts by weight of n-butyl methacrylate, 120 parts by weight of toluene, and 4 parts by weight of 1% rose bengal methanol solution was dispersed in a ball mill for 6 hours. Mixed. This was applied to a 0.05 mm thick aluminum plate using a wire spar so that the dry coating thickness was 40 μm, and the solvent was evaporated with warm air to produce a zinc oxide binder photoreceptor in the form of a drum. 6k for this photoconductor
After performing corona discharge of V to uniformly charge the entire surface, original image irradiation was performed to form an electrostatic latent image.

The above toner was put into a developing device as shown in FIG. 1, and the electrostatic latent image described above was developed. Here, the toner carrier is a stainless steel cylindrical sleeve with an outer diameter of 50 mm, and the distance between the photosensitive drum surface and the creep surface is set to 0.25 m,
400 Hzioov AC and -150 in the sleeve
A DC bias of v was applied.

Next, the powder image was transferred from the back side of the transfer paper while irradiating it with a DC corona of −7 kV to obtain a copied image. Fixing was carried out using a commercially available plain paper copying machine (trade name: NP-5000, Canon #R).

The resulting transferred image had a sufficiently high density of 125, had no fogging, and had no toner scattering 9 around the image, resulting in a good image with high resolution. Durability was evaluated continuously using the above toner, and the transferred image after 10,000 copies was also completely dull compared to the initial image.

In addition, when the environmental conditions were set to 35°C and 85%, the image density was 1.22, a value that was almost unchanged from normal temperature and humidity, and a clear blue image was obtained without fogging or scattering, and it was durable. There was almost no change until 1oooo. Next 1
When a transferred image was obtained at a low temperature and low humidity of 10% at 0° C., the image density was as high as 1°20, and the image was developed and transferred extremely smoothly even with a flat black, and was an excellent image without any scattering or hollow spots. Durability was carried out under these environmental conditions, and the density fluctuation was ±0.2 up to 910,000 copies, which was sufficient for practical use, and no white streaks or blemishes occurred.

Comparative Example 1 The above materials were thoroughly mixed in a blender and then kneaded with two rolls heated to 150°C. After allowing the kneaded mixture to cool naturally, it is coarsely pulverized with a cutter mill, then pulverized with a pulverizer using a jet stream, and further classified with an air classifier to obtain toner raw material fine powder with a particle size of 5 to 20μ. I got it.

Silica fine powder AERO8IL 200 (manufactured by Nippon Aerosil Co., Ltd.) was not treated with isozoropyl triisostearoyl titanate, and 0.6% by weight of the silica fine powder was added to the above toner raw material fine powder, and this was mixed with a Henschel mixer. The mixture was used as a toner.

Using the same developing device as in Example 1 and under the same conditions as in Example 1, the electrostatic latent image formed on the photoreceptor drum was developed and transferred with the above toner, but the reversed image was It was only obtained.

Example 2 Fine silica powder AERO8IL200 (manufactured by Nippon Aerosil Co., Ltd.) was treated with isozolopyl triisostearoyl titanate.
A toner obtained in exactly the same manner as in Example 1 except that it was treated with ethylamino) titanate was used, and development and transfer were carried out in the same manner as in Example 1. The image density was as high as 1.31, and an image faithful to the latent image was obtained with no fogging, scattering, or transfer omission, and high resolution. Even in a durability test of 10,000 sheets, an image with no dark color was obtained compared to the initial image.

After storing this toner for one month in an environment with a temperature of 35°C and a humidity of 90°C, an image was obtained, and the image density was 1.30, which was no different from before storage and the image quality was good.

In addition, images were printed in an environment of a temperature of 35°C and a humidity of 85q6, and very good images were obtained from the beginning, and the images after 10,000 sheets were also good.

Example 3 Example 3 except that instead of treating the silica fine powder AERO8IL200 (manufactured by Nippon Aerosil Co., Ltd.) with isozoropyl triisostearoyl titanate, dianthranyl ethylene titanate was treated to give a concentration of 10% by weight based on the silica. Development and transfer were carried out in the same manner as in Example 1 using the toner obtained in the same manner as in Example 1.

The obtained toner exhibited excellent image quality and durability in various environments: low temperature and low humidity, high temperature and high humidity, and room temperature and normal humidity.

Example 4 Toner obtained in exactly the same manner as in Example 1 was put into the apparatus shown in FIG. 2, and the vibrating member 17 was vibrated at a frequency of 50 Hz and an amplitude of 0.2 m, and the toner carrier 12 was set at a circumferential speed. 120
Rotated at 1@/sea. A uniform toner coating layer having a thickness of about 50 μm was formed on the toner carrier 12. The toner carrier 12 and the electrostatic image holder 11 are faced to each other with a gap of about 300μ maintained, and the toner carrier 12 is supplied with a frequency of 100 to several kilohertz, a negative peak value of -660 to -1200V, and a G/C peak value. Similar good results were obtained when development was carried out by applying a Baianu alternating current electric field of +400 to +800 .mu.m.

Comparative Example 2 Using the same toner as in Comparative Example 1, the electrostatic latent image on the electrostatic image carrier 11 was developed in exactly the same manner as in Example 4 using the developing device shown in FIG. .

In this case, the defects shown in Comparative Example 1 were noticeable.

Example 5 The toner shown in Example 2 was applied with the gap between the toner carrier 22 and the application roller 25 being approximately 2 mm, and the length of the fiber brush 26 being approximately 3 W.
+1 to the developing device shown in FIG. 3, the gap between the toner carrier 22 and the electrostatic image holder 21 is maintained at 300μ, and a single layer of approximately 80μ of toner is formed on the toner carrier 22 to generate an AC waveform. As a result, a DC component of 250 V was added to the peak value of the voltage at a frequency of 200 Hz, ±450 V, and development was performed by applying a peak voltage of +700 V and -200 V.
Similar good results were obtained.

lj1 The toner of Example 3 was applied to the toner carrier 32 and the magnetic roller 3.
5, and the maximum thickness of the magnetic brush 38 is set to be approximately 3 mm, and the gap between the toner carrier 32 and the electrostatic image holder 31 is 300μ
A single layer of toner with a thickness of approximately 80μ was formed on the toner carrier 32, and a DC component of 250V with a frequency of 200 Hz was added to the peak value of the voltage at a frequency of 200Hz to give a peak value of +700V and -200V. When developed, similar good results were obtained.

Example 7 Toner 20F of Example 1 was placed in an iron powder carrier 205m in advance.
The mixture is mixed with the toner carrier 42 and mixed with the toner carrier 42.
The toner is placed in the developing device shown in the figure, the gap between the toner carrier 42 and the electrostatic image holder 41 is maintained at 300μ, and a single layer of approximately 80μ of toner is formed on the toner carrier to generate an AC waveform with a frequency of 2
00 Hz voltage peak value ±450V and DC component 250V
By adding v, the peak value of voltage +700■ and -200■
Similar good results were obtained when the film was developed using

[Brief explanation of the drawing]

FIG. 1, FIG. 2, FIG. 3, FIG. 4, and FIG. 5 each show an example of a developing device used to carry out the developing method according to the present invention. 1: Electrostatic image carrier, 2: Toner carrier, 3: Hopper, 4: Coating means, 5: Insulating non-magnetic toner, 6: Development bias power supply, 11: Electrostatic image carrier, 12: Toner carrier , 13
: Hopper-14: Insulating non-magnetic toner, 15: Toner storage section, 16: Toner supply member, 17: Vibration member,
18: vibration generating means, 19: cleaning blade, 21: electrostatic image holder, 22: toner carrier, 23:
Toner supply section, 24: Toner 25: Application roller,
26: brush 27: toner cleaning member, 28: developing bias power supply, 29: bias power supply for 3m cloth, 31: electrostatic image holder, 32: toner carrier, 33
: developing device main body, 34: toner 35: magnetic roller,
36: Non-magnetic sleeve, 37: Magnet 1.38:
magnetic brush, 39: developing bias power supply, 41: electrostatic image holder, 42:
toner carrier, 43: magnet, 44: hopper,
45: Toner, 46: Toner thickness regulating blade, 47: Bias power supply for development, 48: Magnetic brush. Figure 1 Figure 2

Claims (2)

[Claims] (1) An electrostatic image carrier that holds an electrostatic image on its surface and a toner carrier that carries an insulating non-magnetic toner on its bottom are arranged with a constant gap in the developing section, and titanate coupling is applied. A non-magnetic toner containing fine silica powder treated with an agent is supported on a toner carrier to a thickness thinner than the gap, and the toner is transferred to the electrostatic image carrier in a developing section for development. Characteristic development method. (2) The developing method according to claim (1), wherein in the developing section, an alternating current and/or direct current bias is applied between the toner carrier and the electrostatic image holding surface.