JPH07281475A - Non-magnetic or magnetic single-component developing method - Google Patents

Abstract

PURPOSE:To provide the developing method with which good threshold performance of electrification can be obtained and the change in developing properties due to the environmental change is inhibited from occurring over a long period and also generation of the ghost image due to development liable to occur at the time of performing the thin layer formation type development can be prevented from occurring and further, the developing device is not adversely affected by the sticking of the fused toner, etc., to the device itself and image density is stabilized over a long period and generation of image defects such as fogging, etc., is inhibited from occurring. CONSTITUTION:The non-magnetic single component developing method comprises producing a non-magnetic toner by adding at least inorganic particles to and mixing them with colored particles consisting of at least a resin and a colorant and performing development through carrying in the developing region a developer obtained by forming a thin layer of the non magnetic toner having 10 to 200mum thickness on each of the particles of a developer carrier with a thin layer forming device. At this time, the surface of the thin layer forming device contains at least a magnesium compound represented by the formula Mg(X)n (wherein X is O, CO3 or OH and (n) is an integer of 1 or 2).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a non-magnetic and magnetic one-component developing method for electrophotography.

[0002]

2. Description of the Related Art Conventionally, a one-component developing method has been used as a developing method without a carrier because it has advantages such as simplification of a developing device itself. As the one-component developing method, there are a magnetic one-component developing method using a magnetic developer and a non-magnetic one-component developing method composed only of non-magnetic toner not using a magnetic material. Since neither of them uses a carrier, a method has been proposed in which triboelectric charging between toners is used to impart charge to toners. However, in this case, toners of opposite polarities are generated due to friction between toners, and transfer rate It has drawbacks such as deterioration and generation of character fringes. Further, when the triboelectric charging between the toners is used, the triboelectric charging property on the surface of the developer carrying member is utilized, so that it is essential to make the toner layer thick.
In the case of a magnetic developer, it is possible to hold the magnetic developer by providing a magnet inside the developer carrying member, so it was easy to form a thick toner layer. However, in the non-magnetic one-component developer, since the developer itself has no magnetic force, it is difficult to keep the toner layer thick on the surface of the developer carrying member, and it is theoretically difficult to use the toner mutual friction.

In view of the above problems, a method has been proposed in which a developer layer is formed on the surface of a developer carrier as a thin layer and then development is performed. In this case, since the developer is composed only of toner, the triboelectrification of the toner is performed by a transport member for transporting the developer, a developer carrier, and a thin layer formation for regulating the developer layer. It is given by friction with the device. In this case, since the charge imparting ability has few charging contact points with the two-component developer by mixing with a general carrier,
The charge imparting ability itself is inferior to that of the two-component developer. For this reason, a method has been proposed in which a charge control agent is added to the thin-layer forming apparatus in order to improve the triboelectric charging ability (Japanese Patent Laid-Open No. 61-250666 / 62-24285 / 62). -20
317 / 63-81376 / 63-250662 etc.). In addition, a system in which the same silica that is added to the toner is added to the surface of the thin layer forming device in order to prevent migration of the external additive itself is also proposed for the effect of long-term charge imparting to these charge imparting. (Japanese Patent Laid-Open No. 4-308873). Further, in the magnetic one-component developer, in addition to the charge imparting effect, in order to prevent the so-called development ghost phenomenon that occurs due to the thin developer layer being formed, phenol resin and A system in which fine particles of resistance have been added and mixed has been proposed (JP-A-4-35).
No. 2170).

However, for example, when a charge control agent is added to and mixed with a thin layer forming apparatus, the material itself is composed of a pigment, and therefore, when it is used for a long period of time, the thin layer forming apparatus is worn out. There is a problem that the charge control agent is released and adheres to the toner or the like, which hinders the charging property. Furthermore, when the same silica added to the toner is added, so-called hydrophobicity is the main material, and there is a problem in that the chargeability changes with environmental changes. It is presumed that this is because the change in water content is one of the causes of the change in chargeability depending on the environment, and the charge imparting ability due to the change in water content is not constant with silica. Furthermore, when the developer carrier is coated with a material with low resistance, the problem of charge leakage in a high temperature and high humidity environment occurs due to the low resistance, and even in this case, it is necessary to prevent changes in developability due to environmental changes. Was difficult.

[0005]

In view of the above problems, the object of the present invention is that the charging start-up performance is good, there is no change in developability due to environmental changes over a long period of time, and it is likely to occur in the so-called thin layer forming method. It is possible to prevent development ghost, and further, there is no change due to fusion of toner or the like to the developing device itself, so-called stable non-magnetic image density over a long period of time, and non-magnetic or magnetic non-magnetic property. It is to provide a component developing method.

[0006]

The above object of the present invention can be achieved by the following constitutions.

1. A non-magnetic toner obtained by adding and mixing at least inorganic fine particles to colored particles containing at least a resin and a colorant in a thin layer forming device in a developing region on a developer carrying member in a thin layer of 10 to 200 μm. In a non-magnetic one-component developing method for carrying a developer and developing, a non-magnetic one-component developing method characterized in that the surface of the thin layer forming apparatus contains at least a magnesium compound represented by the following general formula. .

Mg (X) n Here, X represents O / CO ₃ / OH, and n represents an integer of 1 or 2.

2. A non-magnetic toner obtained by adding and mixing at least inorganic fine particles to colored particles containing at least a resin and a colorant in a thin layer forming device in a developing region on a developer carrying member in a thin layer of 10 to 200 μm. A non-magnetic one-component developing method in which a developer is conveyed and developed, wherein the surface of the developer-carrying member contains at least a magnesium compound represented by the following general formula: .

Mg (X) n Here, X represents O / CO ₃ / OH, and n represents an integer of 1 or 2.

3. A magnetic toner prepared by adding and mixing at least inorganic fine particles to colored particles containing at least a resin and magnetic powder is developed by a thin layer forming device in a developing region in a thin layer of 10 to 200 μm on a developer carrier. A magnetic one-component developing method for carrying out development by carrying an agent, wherein the surface of the thin layer forming device contains at least a magnesium compound represented by the following general formula.

Mg (X) n Here, X represents O / CO ₃ / OH, and n represents an integer of 1 or 2.

4. A magnetic toner prepared by adding and mixing at least inorganic fine particles to colored particles containing at least a resin and magnetic powder is developed by a thin layer forming device in a developing region in a thin layer of 10 to 200 μm on a developer carrier. A magnetic one-component developing method for carrying out development by carrying an agent, wherein the surface of the developer carrying member contains at least a magnesium compound represented by the following general formula.

Mg (X) n Here, X represents O / CO ₃ / OH, and n represents an integer of 1 or 2.

That is, the magnesium compound proposed in the present invention is a material having a particularly large charging property and exhibiting a positive charging property, and imparts a large negative charging property to the toner. Furthermore, the crystal structure has a number average primary particle diameter of 1 to 200 nm.
Since it is small, it is possible to provide a large number of charging points, and it is possible to accelerate the rise of charging. Further, this compound itself has a relatively high resistance of about 10 ⁶ to 10 ¹⁰ Ωcm, is a material with almost no leakage of charging due to environmental changes, and can prevent the target development ghost phenomenon. It is a possible material.

The present invention will be described in detail below.

Thin layer forming magnetic one-component developing method and non-magnetic one-component developing method The thin layer forming method is 20 to 50 in the developing area on the surface of the developer carrier.
A method for forming a toner layer of 0 μm is shown. When forming this thin layer, there are a magnetic blade that uses a magnetic force and a method of pressing a toner layer regulating rod against the surface of a developer carrying member.
Further, there is also a method in which a urethane blade, a phosphor bronze plate or the like is brought into contact with the surface of the developer carrying member to regulate the toner layer.

As the developer carrying member, in the case of a magnetic one-component developer, a developing unit having a magnet built in the carrying member is used. As the developer carrying member surface, aluminum or the surface is oxidized. Aluminum or stainless steel is used. On the other hand, in the case of a non-magnetic one-component developer, the developer bearing member is made of urethane rubber or silicon rubber.

The pressing force of the pressing regulating member is preferably 1 to 15 gf / mm.

When the pressing force is small, the regulation force is insufficient and the conveyance becomes unstable. On the other hand, when the pressing force is large, the stress on the developer increases, so that the durability of the developer decreases. The preferred pressing force range is 3-10gf
/ Mm.

The gap between the developer carrying member and the photosensitive member surface may be larger or smaller than the toner layer. Further, a system in which only the DC component is applied as the developing bias may be used, or AC
Any method of applying a bias may be used.

As the size of the developer carrying member, the diameter is 10 to
40 mmφ is preferable. When the diameter is small, it is difficult to ensure sufficient contact for imparting charge to the toner, and when the diameter is large, the centrifugal force on the toner becomes large, which causes a problem of toner scattering.

In the method of applying the magnesium compound of the present invention to these developer carrying members or thin layer forming apparatuses, the magnesium compound of the present invention is added to and dispersed in a resin solution. The solvent that constitutes the resin solution is preferably a volatile solvent, which has high resin solubility and low water adsorption. Specifically, although it varies depending on the resin, a ketone solvent such as methyl ethyl ketone and acetone, an aromatic solvent such as benzene, toluene and xylene, and an ester solvent such as ethyl acetate are preferable. In addition, methanol,
An alcohol solvent such as ethanol and an ether solvent such as ethyl ether may be added to adjust the solubility. The concentration of the solvent is preferably 1 to 20 wt% of the resin in the solvent. This is because if the concentration is 1 wt% or less, the resin concentration is low and it is difficult to control the film thickness to a desired value, and if it is 20 wt% or more, the resin concentration is high and it is difficult to perform coating.

The resin for coating is not particularly limited. Specific examples include styrene resins, acrylic resins, styrene / acrylic resins, polyester resins, urethane resins, silicone resins, and phenol resins. These resins may be used after being coated and then crosslinked by heating or reaction.

The magnesium compound of the present invention may be added in an amount of 10 to 100 parts based on 100 parts of the resin. If the addition amount is small, the effect of the present invention is not exhibited, and if the addition amount is large, the problem of uneven charging due to liberation of magnesium compound or generation of aggregates occurs.

The amount of resin coating on the developer carrier or the thin layer forming apparatus depends on the film thickness in the triboelectric charging section.
It is 0.1 to 100 μm, and particularly preferably 0.5 to 50 μm. When the film is thin, the durability is lost, and when the film is thick, unevenness is generated in the application of bias, which causes a problem of image unevenness.

As a method for coating the developer carrier or the thin layer forming apparatus with a resin, the developer carrier or the thin layer forming apparatus is dip-coated with a solution in which a resin and the magnesium compound of the present invention are dispersed, and dried. There is a way to do it. Further, a coating method using a spiral coater, a roll coater or the like can be used.

As a method of dispersing the magnesium compound in the resin solution, it is preferable to use a dissolver, a sand grinder, a ball mill, ultrasonic waves or the like.

The film thickness can be measured with a contact type film thickness meter. Further, a method of measuring by cross-section observation may be used.

Structure of Developer The developer is not particularly limited.

The toner used in the present invention is a toner obtained by adding and mixing inorganic fine particles to colored particles containing a binder resin, a colorant, and other additives used as necessary. The average particle size is a volume average particle size, usually 1 to 30 μm,
It is preferably 5 to 15 μm. The binder resin that constitutes the colored particles is not particularly limited, and various conventionally known resins can be used. For example, styrene resin, acrylic resin, styrene / acrylic resin, polyester resin, etc. may be mentioned. The colorant is not particularly limited, and various conventionally known materials can be used. In the case of non-magnetic one-component toner, carbon black, nigrosine dye, aniline blue, calcoil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow,
Examples include methylene blue chloride, phthalocyanine blue, malachite green oxalate, rose bengal, and the like. Examples of other additives include charge control agents such as salicylic acid derivatives and azo metal complexes, and fixability improving agents such as low molecular weight polyolefins and carnauba wax. When a one-component magnetic toner is obtained, the colored particles contain magnetic particles as an additive. As the magnetic particles, magnetic particles such as ferrite and magnetite having a number average primary particle diameter of 0.1 to 2.0 μm are used. The amount of the magnetic particles added is 20 to 70% by weight of the colored particles.

Further, as the toner, silica is used as colored particles,
In addition to inorganic fine particles such as titanium oxide and aluminum oxide (which may be hydrophobized), styrene-acrylic resin fine particles having a number average particle diameter of 0.1 to 2.0 μm as a cleaning aid, and higher fatty acid metal such as zinc stearate. Salt may be added. The amount of the inorganic fine particles added is preferably 0.1 to 2.0 wt% with respect to the colored particles. The cleaning aid is preferably 0.01 to 1.0 wt% with respect to the colored particles.

Specific examples of the magnesium compound of the present invention will be described below.

Mg (X) n Here, X represents O / CO ₃ / OH, and n represents an integer of 1 or 2.

[0035] More specifically, are exemplified magnesium oxide, magnesium-magnesium carbonate hydroxide, in addition to (3-5) of one of the magnesium carbonate composition of MgCO ₃ MgCO ₃ · Mg
It also includes magnesium hydroxycarbonate having a composition of (OH) ₂ · (3-7) H ₂ O. Further, a compound obtained by subjecting the above magnesium compound to a hydroxylation treatment may be used. These are obtained by subjecting magnesium oxide, magnesium carbonate and the like to a hydroxylation treatment. Hydroxylation treatment is magnesium oxide
It can be obtained by reacting magnesium carbonate or the like with steam containing no carbon dioxide.

The above magnesium compound has a number average primary particle diameter of 1 nm to 200 nm and a BET specific surface area of 500 to 10 m ² /
g is preferred. Especially, the number average primary particle diameter is 5 nm to 100 n
Particles having m and BET specific surface area of 200 to ²⁰ m ² / g are more preferable from the viewpoint of dispersibility. Particle size is less than 1 nm, BET value is 50
Particles having a particle size of 0 m ² / g or more are less likely to exhibit the spent prevention effect. Also, if the particle size exceeds 200 nm, BET value is 10 m ²
Particles of / g or less are difficult to disperse in the coating layer, the amount of free components increases, and the chargeability with the toner is likely to be impaired. The number average primary particle diameter indicates the number average primary particle diameter measured by a transmission electron microscope LPA-3000 / 3100 (manufactured by Otsuka Electronics). BET specific surface area is measured by Flow S
The value measured by the one-point method measured by orb 2300 (manufactured by Shimadzu Corporation) is shown. Furthermore, as the resistance, 10 ⁶ to 10
It is preferably ¹⁰ Ωcm. The resistance measurement method indicates a value measured in a powder state under the condition that a constant pressure is applied. In this measurement, the volume resistivity measured in a normal temperature and normal humidity environment is shown.

Magnesium oxide can be formed by burning metallic magnesium. In this case, the particle size of magnesium oxide or the like can be adjusted by controlling various combustion conditions. Further, the method for producing magnesium carbonate can be performed, for example, by obtaining sodium trihydrate crystals by adding sodium carbonate to an aqueous solution of a magnesium salt such as magnesium oxide while passing carbon dioxide. Furthermore, an anhydrous salt is obtained by drying and dehydrating this in a carbon dioxide stream. Further, the magnesium carbonate produced in the gas phase reaction can produce a single crystal by reacting the magnesium metal vapor in a steam atmosphere containing carbon dioxide. A single crystal structure obtained by a gas phase reaction is particularly preferable. The single-crystal magnesium carbonate obtained by the gas-phase reaction has a higher purity than general polycrystalline magnesium carbonate, and has a remarkable effect in improving the charge rising characteristics. Magnesium hydroxide can be obtained by adding an alkali to an aqueous solution of magnesium salt of magnesium oxide and heating and pressurizing. Further, magnesium hydroxide produced by a gas phase reaction can be produced by hydroxylating metallic magnesium vapor in a steam atmosphere containing no carbon dioxide to produce a single crystal. Hydroxylated magnesium compounds are particles of magnesium oxide, magnesium carbonate, etc.
The treatment can be performed by leaving it for 1 hour in an atmosphere of 50 ° C. and 80% RH. In this case, the mixing may be performed in a specific container, or the treatment may be performed by a fluidized bed device.

[0038]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

Resin Dispersion Preparation Example 1 100 parts of phenol resin and BE with number average primary particle size = 12 nm
Mix 20 parts of MgO of T = 152 m ² / g and 1000 parts of a mixed solution of methyl alcohol and methyl cellosolve as a solvent for the resin.
The mixture was stirred, and MgO was dispersed by a dissolver. This dispersion is referred to as "dispersion 1".

Production Example 2 of Resin Dispersion Liquid In Production Example 1 of resin dispersion liquid, styrene resin was used in place of phenol resin, and MgO having a number average primary particle size of 50 nm and BET = 41 m ² / g was used as MgO. Then, a dispersion liquid was obtained in the same manner except that toluene was used as a solvent.
This dispersion is referred to as "dispersion 2".

Production Example 3 of Resin Dispersion Liquid In Production Example 1 of Resin Dispersion Liquid, styrene-acrylic resin was used in place of the phenol resin, and the number average primary particle size was 25 nm instead of MgO and BET = 132 m ² / g. A dispersion was obtained in the same manner except that MgCO ₃ was used. This dispersion is referred to as "dispersion 3".

[0042] In resin dispersion Preparation Example 4 Resin Dispersion Preparation Example 1, dispersion in the same manner except that the number average primary particle diameter was used 115nm / BET = 15m ² / g of Mg (OH) ₂ instead of MgO Got This dispersion is referred to as "dispersion 4".

Developer Carrier Production Example 1 [Dispersion liquid 1] was used on the surface of a developing sleeve made of magnetic stainless steel having a diameter of 25 mm and containing a fixed magnet of 6 poles. A layer in which MgO was dispersed in phenol resin was formed with a film thickness. This is referred to as "magnetic developer carrier 1".

Production Example 2 of Developer Carrier On the sleeve surface in the same manner as in Production Example 1 of developer carrier, except that "dispersion liquid 2" was used instead of "dispersion liquid 1".
It was coated with a resin layer in which MgO was dispersed in styrene resin with a film thickness of 15 μm. This is referred to as "magnetic developer carrier 2".

Manufacturing Example 3 of Developer Carrier On the sleeve surface in the same manner as in Manufacturing Example 1 of developer carrier, except that "dispersion liquid 3" was used instead of "dispersion liquid 1".
A resin layer in which MgCO ₃ was dispersed in a styrene-acrylic resin was coated with a film thickness of 10 μm. This is referred to as "magnetic developer carrier 3".

Manufacturing Example 4 of Developer Carrier For a developing sleeve having a diameter of 25 mmφ formed of silicone rubber, "resin dispersion liquid 4" was applied on the developing sleeve surface in the same manner as in Manufacturing Example 1 of developer carrier. Then, a phenol resin was coated with a resin layer in which Mg (OH) ₂ was dispersed. This is referred to as "developer carrier 4".

Manufacturing Example 1 of Thin Layer Forming Member In Manufacturing Example 1 of developer carrier, MgO was added to phenol resin in a thickness of 15 μm in the same manner except that a magnetic stainless rod having a diameter of 2 mm was used instead of the developing sleeve. A dispersed resin layer was formed. This is referred to as "thin layer forming member 1".

Manufacture Example 2 of thin layer forming member In the same manner as Manufacture example 2 of developer carrier, MgO was dispersed in styrene resin in a thickness of 25 μm except that a magnetic stainless rod having a diameter of 2 mm was used instead of the developing sleeve. Coated resin layer. This is referred to as "thin layer forming member 2".

Thin Layer Forming Member Manufacturing Example 3 In the same manner as in Manufacturing Agent Developing Material Manufacturing Example 2, except that an adjacent bronze plate having a thickness of 0.5 mm was used instead of the developing sleeve.
It was coated with a resin layer in which MgO was dispersed in styrene resin with a film thickness of μm. This is referred to as "thin layer forming member 3".

Thin Layer Forming Member Production Example 4 In the same manner as in Production Example 3 of Developer Carrier, except that a urethane rubber sheet having a thickness of 3 mm was used in place of the developing sleeve, a styrene-acrylic resin having a film thickness of 30 μm was obtained. It was covered with a resin layer in which MgCO ₃ was dispersed. This is referred to as "thin layer forming member 4".

Development Method 1 to 3 of the Present Invention A laser printer LP-3015 manufactured by Konica was modified so that the printing speed in A4 longitudinal feeding was 20 sheets / min.
3, the developing area gap: Dsd = 0.2 mm, the toner layer on the surface of the developing device in the developing area is pressed with a regulation pressure of 5 gf / mm, and a magnetic stainless rod of 2 mm in diameter is used for 0.15.
It was modified to a non-contact type with mm. The photosensitive member is a laminated organic photosensitive member, the developing portion potential is -500V, the developing bias is -50 to -550V from peak to peak, and the frequency is 2kHz.
A C bias and a DC bias of -250V were applied. This will be referred to as "invention developing methods 1 to 3".

Development Methods 4 to 5 of the Invention Konica laser printer LP-3015 was modified to make the printing speed at A4 longitudinal feed 20 sheets / min, and made of magnetic stainless steel having a diameter of 25 mm with a built-in 6-pole fixed magnet. Using a developing sleeve, the developing area gap: Dsd = 0.2 mm, the toner layer on the surface of the developing device in the developing area is pressed with a regulation pressure of 5 gf.
/ Mm and using the thin layer forming members 1 and 2, the non-contact method was changed to 0.15 mm. The photosensitive member was a laminated organic photosensitive member, the developing portion potential was -500V, and the developing bias was applied from a peak to a peak of -50 to -550V with an AC bias of 2kHz and a DC bias of -250V. This will be referred to as "invention developing methods 4 to 5".

Developing Method 6 of the Present Invention By modifying Konica LP-3110, "Developer carrying member 4" is used as a developing sleeve, and a toner layer regulating member made of urethane rubber is brought into contact with the surface of the developing sleeve to form toner. Regulated layers. Further, the photosensitive member and the surface of the developing sleeve are in contact with each other so that the nip width is about 2 mm.
As the photoconductor, a laminated organic photoconductor is used. The developing conditions were such that the surface potential of the photoconductor was -550 V and the DC bias was -450 V, and the reversal development was performed. This is designated as Development Method 6 of the present invention.

Development Method 7-8 of the present invention: LP-3110 made by Konica is modified to have a developing sleeve with a diameter of 18 m.
An elastic sleeve formed of a silicone rubber roller of m was used, and the thin layer forming members 3 to 4 were brought into contact with the surface of the developing sleeve to regulate the toner layer. Further, the photosensitive member and the surface of the developing sleeve are in contact with each other so that the nip width is about 2 mm. As the photoconductor, a laminated organic photoconductor is used. The developing condition is that the surface potential of the photoreceptor is −550V,
Development was performed by reversal development with a DC bias of -450V. This will be referred to as "invention developing methods 7 to 8".

Developer Example 1 100 parts of styrene-acrylic resin, 50 parts of magnetite, 1 part of charge control agent and 3 parts of low molecular weight polypropylene were kneaded, pulverized and classified according to a conventional method to give a volume average particle diameter of 9.1 μm. Magnetic particles were obtained. To this one, add hydrophobized silica.
8 parts by weight were added to obtain a magnetic toner.

Developer Production Example 2 Nonmagnetic colored particles having a volume average particle diameter of 8.7 μm were obtained in the same manner as in Developer Production Example 1 except that 10 parts of carbon black was used instead of magnetite. 0.7 parts by weight of hydrophobized silica was added to this product to obtain a non-magnetic toner.

(Evaluation) Evaluation was carried out using the developing method described above. In the developing methods 1 to 4 of the present invention, a magnetic toner was used, and in the developing methods 5 to 8 of the present invention, a non-magnetic toner was used.
For comparison, the developer method of the present invention using a developing sleeve not covered with a resin layer is referred to as Comparative developing method 1 (in this case, a toner is a magnetic toner),
Comparative Development Method 2 was used in Development Method 5 of the present invention, in which a developer carrying member not coated with a resin layer was used (in this case,
Non-magnetic toner was used). The evaluation evaluated the initial density and fog in a low temperature and low humidity (LL) environment, and further evaluated the high temperature and high humidity (H
H) 100,000 sheets were printed under the environment (33 ° C / 80% RH), and the change in image density and the change in fog density were measured.
The image density is obtained by measuring 12 points of a solid black image and averaging them. In addition, the difference between the maximum density and the minimum density in these 12 measurement points was measured to evaluate density unevenness.
These densities are measured by the Macbeth reflection densitometer RD.
-918 is used and it is an absolute reflection density. The fog density is a relative density when the density of the paper is 0. The fog density is obtained by printing a solid white image, measuring the densities of the 12 points, and averaging the densities.

The results are shown below.

[0059]

[Table 1]

As shown in the above results, it is understood that the developing method of the present invention has a stable concentration under environmental changes and is excellent in durability.

That is, as the results show, in the low-temperature and low-humidity environment, the developing method of the present invention forms an image with less fog and good density. Further, even under high-temperature and high-humidity environment, the fog is small and the density is good. It can be seen that a stable image with no density unevenness can be obtained.

[0062]

INDUSTRIAL APPLICABILITY The non-magnetic and magnetic one-component developing methods according to the present invention have good charging start-up performance, no change in developability due to environmental changes over a long period of time, and prevent development ghosts that are likely to occur in a thin layer forming method. Further, there is no change due to the fusion of the toner or the like to the developing device itself, the image density is stable for a long period of time, and a good image that does not cause image defects such as fog can be obtained.

Claims (4)

[Claims] 1. A non-magnetic toner obtained by adding and mixing at least inorganic fine particles to colored particles containing at least a resin and a coloring agent is applied to a developer carrier in a developing region by a thin layer forming device in an amount of 10 to 10%. In a non-magnetic one-component developing method in which a developer is conveyed and developed in a thin layer of 200 μm, the surface of the thin layer forming apparatus contains at least a magnesium compound represented by the following general formula: Magnetic one-component development method. Mg (X) n, where, X is shows the O / CO ₃ / OH, n is an integer of 1 or 2. 2. A non-magnetic toner comprising at least inorganic fine particles added to and mixed with colored particles containing at least a resin and a colorant in a thin layer forming apparatus in a developing area to form a non-magnetic toner in an amount of 10 to 10%. In a non-magnetic one-component developing method in which a developer is conveyed in a thin layer of 200 μm for development, the surface of the developer carrying member contains at least a magnesium compound represented by the following general formula: Magnetic one-component development method. Mg (X) n, where, X is shows the O / CO ₃ / OH, n is an integer of 1 or 2. 3. A magnetic toner prepared by adding at least inorganic fine particles to colored particles containing at least a resin and magnetic powder and mixing them with a thin layer forming apparatus in a developing region on a developer carrying member in an amount of 10 to 200 μm. In the magnetic one-component developing method of carrying a developer in a thin layer for development, a magnetic one-component comprising at least a magnesium compound represented by the following general formula on the surface of the thin-layer forming apparatus. Development method. Mg (X) n, where, X is shows the O / CO ₃ / OH, n is an integer of 1 or 2. 4. A magnetic toner prepared by adding at least inorganic fine particles to colored particles containing at least a resin and magnetic powder and mixing them with a thin layer forming device in a developing region on a developer carrying member in an amount of 10 to 200 .mu.m. In the magnetic one-component development method of carrying a developer in a thin layer for development, the magnetic one-component development method is characterized in that the surface of the developer carrying member contains at least a magnesium compound represented by the following general formula. Development method. Mg (X) n, where, X is shows the O / CO ₃ / OH, n is an integer of 1 or 2.