JPS63135973A - Developing device - Google Patents

Abstract

PURPOSE:To eliminate fogging, and to attain an image formation with high density and visibility, by providing a fixed magnet roll arranged in the inside of a developing agent carrier, and a developing agent layer thickness regulating member arranged adjacently to the outer surface of the developing agent carrier and constituted of a magnetic material. CONSTITUTION:The titled device is provided with a developing agent vessel which accommodates a two-component developing agent consisting of toner and a microcarrier, the developing agent carrier being rotated in the vessel, the fixed magnet roll 3 arranged in the inside of the developing agent carrier, and the developing agent layer thickness regulating member 4, at least a part arranged adjacently to the outer surface of the developing agent carrier of which is constituted of the magnetic material. And the layer thickness of a developing agent layer to be carried to a latent image plane with the developing agent carrier and the magnet roll 3 is regulated under the influence of a magnetic function acting between the developing agent layer thickness regulating member 4 and the magnetic roll 3. In such way, it is possible to eliminate base fogging, to obtain a clear image with high density, and especially to obtain the image without color turbidity when it is applied in multilevel image formation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a development vc system for developing a latent image on an image forming body, and in particular to a developer layer which is regulated under the influence of magnetic force and turned into ff waste. The present invention relates to a developing device for developing the latent image.

[Background of the invention]

Conventionally, in the fields of electrophotography, electrostatic printing, electrostatic recording, etc., devices that use a powder developer to develop an electrostatic latent image formed on an image forming body use a -component developer. There are two main types: those that use two-component developers.

When using a two-component developer, there is a powder cloud developing device that uses magnetic or non-magnetic toner as the main component in a spray state, and a two-component developer that uses magnetic toner as the main component to be transported by magnetic force. There is a developing device that develops a latent image by bringing a magnetic brush into direct contact with the surface of the latent image.

In addition, when using a two-component developer, for example, the average particle size is 50 to 5.
Using a developer consisting of a relatively large particle size magnetic carrier of 00 μm and a relatively small particle size nonmagnetic toner with an average particle size of 1 to 30 μm, a magnetic brush is directly applied as in the case of using the above-mentioned -component developer. There is a developing device that develops the latent image by contacting it with the surface.

In such a developing device, the toner directly contacts the entire surface of the latent image surface, that is, both the image area and the non-image area of the latent image surface, causing problems such as ground force blurring and the image becoming smeared and unclear.

Therefore, for example, in Tokusho 1wI No. 18859,
The two-component developer flow conveyed on the sleeve is regulated by a layer thickness regulating member so that the developer layer is thinner than the gap (100 to 500 μm) between the sleeve and the latent image surface, for example, 100 μm or less, and An oscillating electric field is formed by applying an alternating current bias with a peak voltage of 800 to 1200 V at a frequency of IKIIz or less between the toner and the latent image surface, and the oscillating electric field causes the magnetic toner to fly toward the latent image surface without contact. A method and apparatus for developing is described.

According to the non-contact developing method and apparatus, even if the toner flies off due to the forward voltage of the AC bias and adheres to the non-image area, the toner is pulled back to the sleeve side by the reverse voltage, thereby preventing the occurrence of ground force blur. and clear images can be obtained. However, in the non-contact development method, in order to achieve effective development, the developer layer is required to be a uniform thin layer of, for example, 30 to 100 μl, which poses a major obstacle. For example, JP-A-57-2012
In Japanese Patent No. 55, the magnetic poles of a magnet roll disposed inside the sleeve are arranged opposite each other, and the magnetic poles are arranged close to the outer surface of the sleeve.
A technique is disclosed in which a thin layer of a two-component developer containing magnetic toner as a main component is formed using a magnetic regulating member.

That is, it is described that the developer flow is regulated into a thin layer by a magnetic curtain formed between the magnetic regulating member and the magnetic pole of the magnet roll facing the magnetic regulating member.

However, in the developing methods and devices described in the above-mentioned publications, a two-component developer is used, and the magnetic toner, which is the main component of the developer, originally contains magnetic powder dispersed in a binder resin. The content of the magnetic material in the toner is at most 50% by weight in view of the resistance value and processability of the resulting toner.

Therefore, the magnetic attraction force of the magnet roll against the two-component developer flow conveyed on the sleeve is weak (the developer flow is unstable and easily scatters, and such unstable developer flow is regulated by a magnetic curtain. However, the effect of thinning the layer is small (,
Moreover, there is also a problem in the uniformity of the regulated development MM.

In addition, -component developers have insufficient triboelectric charging and the amount of toner charge is small, so not only in contact development, but also in non-contact developers, the toner flying due to the oscillating electric field is insufficient, resulting in poor development. There are problems such as insufficient density of the image obtained.

Furthermore, when the toner is used for forming color images, there are problems such as color turbidity due to the presence of magnetic material in the toner, making it difficult to form clear color images.

[Problem that the invention seeks to solve]

Therefore, there is a need for a developing device that develops the toner in a non-contact manner using a two-component developer that has excellent magnetic conveyance properties, fluidity, triboelectric charging properties, etc., and does not contain a magnetic substance in the toner. However, the conventional two-component developer used is one consisting of a relatively large particle size magnetic carrier with an average particle size of 50 to 500 μm and a relatively small particle size magnetic toner with an average particle size of 1 to 30 μm, and contains such a large particle size carrier. With a developer, it is difficult to make a thin layer, and since the carrier vibrates little due to the oscillating electric field, the toner attached to the carrier is difficult to fly away, making it unsuitable for non-contact development. As a result of intensive studies, the inventors of the present invention discovered a developing device that uses a two-component developer and is capable of developing a thin layer, and completed the present invention.

[Means for solving problems]

(Objective of the Invention) An object of the present invention is to provide a developing device that is capable of forming high-density, clear images and is suitable for color development.

(Structure of the Invention) The above object is to provide a developer container containing a two-component developer consisting of toner and microcarriers, a developer transport carrier that rotates within the container, and a developer transport carrier disposed inside the developer transport carrier. A fixed magnet roll and a fixed magnet roll arranged close to the outer surface of the developer transport carrier! ! and a developer layer thickness regulating member, at least a portion of which is made of a magnetic material, and the layer thickness of the developer layer conveyed to the latent image surface by the developer conveying carrier and the magnetic roll is controlled by the developer layer. This is achieved by a developing device that regulates the agent layer thickness under the influence of the magnetic action acting between the agent layer thickness regulating member and the magnet roll, and in particular, a developing device that performs non-contact development.

(Detailed Description of the Invention) That is, in the developing device of the present invention, a two-component developer consisting of a magnetic microcarrier with an average particle size of 15 μm or more and less than 50 μm and a non-magnetic toner with an average particle size of 1 to 30 μm is used. It will be done. The average particle size here refers to the number-based average particle size (hereinafter omitted), where the carrier in the two-component developer is usually a ferromagnetic material, and the component ratio of the magnetic material in the developer is constant. Since the amount of the developer is much larger than that of the component developer, the magnetic force acting between the layer thickness regulating member and the magnet roll acts accordingly, and the developer layer thickness is regulated more effectively.

It is presumed that such regulation of the thickness of the developer layer is carried out as follows.

That is, the developer flow that is conveyed on the sleeve and attempts to pass through the gap between the layer thickness regulating member and the developer transport carrier (hereinafter referred to as a sleeve) is not limited to the mechanical layer thickness regulation by the gap. Preferably, the fixed magnet roll is regulated by magnetic action between a magnetic layer thickness regulating member provided opposite to a specific magnetic pole.

At this time, the upper layer of the developer flow is suppressed by the magnetic action of the magnetic layer thickness regulating member that is sensitive to the specific magnetic pole of the magnet roll, and only the remaining lower developer flow is suppressed by the magnetic attraction force of the magnet roll and the sleeve. The image is transported to the developing area by the transport force. Here, the layer 7I7 is regulated by the magnetic force because the developer used is a two-component developer that contains a much larger amount of magnetic component than the conventional one-component developer, so the magnetic force acts effectively. . For example, a magnetic material of the layer thickness regulating member is provided facing a specific magnetic pole of a magnet roll to form a perpendicular magnetic field to regulate the layer thickness.

In this case, it is possible to move through a thinner developer layer without changing the size of the gap between the sleeve and the layer thickness wind 1a11 member, and since the vertical magnetic field originally has a horizontal spread, the layer thickness regulation is It is loosely regulated over a relatively wide range.

Therefore, it is possible to form a much more uniform and thinner developer layer than when using conventional mechanical layer thickness regulating means.

Further, in order to prevent the developer flow from flowing directly into the narrow gap between the tip of the layer thickness regulating member and the sleeve and creating a turbulent flow, a horizontal magnetic field may be formed instead of the vertical magnetic field. That is, the first
As shown in the figure, the magnetic regulating member 4 is
, S magnetic pole, and may be arranged to regulate the flow of the developer transported by a horizontal magnetic field formed between the tip of the magnetic regulating member 4 and the N pole. Note that the regulating member 4 may be moved to an appropriate position between the N and S@magnetic poles to regulate by an intermediate magnetic field between the vertical magnetic field and the horizontal magnetic field. Here, the range θ in which the magnetic regulating member 4 can move between the magnetic poles is preferably set to 0 and θ1<60°.

In the developing device of the present invention, since the developer carrier accommodated in the 'gcWl is a microcarrier, it vibrates relatively easily due to the oscillating electric field, and therefore the toner adhering to the carrier is Asahikawa is more easily directed toward the image forming body, and as a result, non-contact development becomes possible.

In addition, in the developing device of the present invention, the surface condition of the sleeve, which is the main developer conveying means, directly affects the conveying force, and the degree of roughness is smaller than the calif particle size, and the roughness of the sleeve is 1 to 50 μm. It is better to

Furthermore, in the developing device of the present invention, the layer thickness regulating member 4
The developer layer defined by i1i+1 may be configured to develop the electrostatic latent image on the image forming body with the magnetic pole of a fixed magnet roll in the development area facing the image forming body; In order to achieve thin layer development, JP-A-60-176
As described in Japanese Patent No. 069, it is preferable to shift the magnetic pole of the fixed magnet roll from the position facing the image forming body to form a horizontal magnetic field component, and to develop under the horizontal magnetic field component. .

As the developing device of the present invention, for example, one having the following structure as shown in Fig. tPJ2 is used. Fixed magnet rolls with alternating magnetic poles, 4
5 is a developer reservoir, 6 is an agitator, and 7 is a replenishing toner T. 8 is a toner hopper; 9 is a power supply for applying a DC bias necessary for preventing fog during regular development or a DC bias necessary for reverse development to the sleeve 2; 10 is a sleeve for non-contact development. Power supply for applying AC bias to 2, R
is the protective resistance. In the developing device shown in Fig. Pt52, the non-magnetic insulating toner T in the hopper 8 is replenished into a two-component developer consisting of microcarriers and toner by a quantitative replenishment roller ruff, stirred and mixed by an agitator 6, and frictionally charged. Ru. This developer layer is conveyed while forming spikes by the action of the sleeve 2 and the magnet roll 3, but on the way, it is regulated by the development M layer thickness regulating member 4 and is made into a thin layer, and is conveyed to the development area. . Development in the development area K is performed by applying an AC bias from a power source 10 to cause the toner to fly toward the image forming body 1, thereby developing the electrostatic latent image on the surface of the image forming body 1 in a non-contact manner. .

Here, the gap d between the image forming body 1 and the sleeve 2 is set to be 1-100 m or less, and the gap between the developer layer thickness regulating member 4 and the sleeve 2 is smaller than the above-mentioned gap d, preferably 500 μm or less. Furthermore, the thickness of the developer layer in the development area K is preferably 400 .mu.m or less and more than 100 .mu.m. When the layer thickness is less than 100 μm, the thickness of the developer layer becomes non-uniform, and unlike in the case of a -component developer, a considerable amount of carrier coexists, resulting in an insufficient amount of toner and a decrease in image density. If it exceeds 40,011 ta, the developing M layer will be too thick, and the effect of AC bias on the toner particles on the surface will be reduced, making it difficult to fly, and the non-contact developing effect will be reduced. The frequency of the AC bias is greater than IKIIz and less than 10K11z, and its peak i voltage is 500~4
It is said to be KV. If the frequency of the second-stream bias is below IKIlz, toner flight will be insufficient, and 10K If z
If the value exceeds the value, the flying toner cannot follow the frequency of the oscillating rEJ electric field, and on the contrary, the image density decreases, and furthermore, carrier adhesion occurs. Also, the tip [7FC pressure is 500
If it is less than V, toner flight will be insufficient, and if it exceeds 4 KV, carrier adhesion will occur, which is not preferable.

In addition, the DC bias from the power source 9 has a polarity opposite to that of the toner in the case of regular development, and is usually set at 50 to 500 cm to prevent toner from adhering to non-image areas and reduce ground blurring. When reversal development is performed using toner having the same polarity as the latent image charge on the image forming member, a DC bias having the same polarity as the toner and close to the surface potential of the image forming member is applied.

Next, the developer layer thickness regulating member 4 is made of a magnetic material at least in part, and cooperates with the magnet roll 3 built into the sleeve 2 to magnetically regulate the developer flow and form a thin layer. be made into Examples of the form of the developer layer thickness regulating member 4 include various forms shown in FIGS. 3 to 5, for example.

(a) to (e) in FIG. 3 are regulating members made only of magnetic materials of various shapes, and are disposed on the sleeve 2 rotating in the direction of the arrow, and a magnet roll 3 fixed inside the sleeve 2. The thickness of the developed ITII layer is regulated in cooperation with the magnetic force of . Fig. 3 (a) shows a regulating member with a rectangular cross section whose lower surface is arranged parallel to the plane of the sleeve 2, and Fig. 3 (b) shows a regulating member with a wedge-shaped cross section, with a plane parallel to the plane of the sleeve 2 at the tip of the protrusion at the lower end. FIG. 3(c) has an inclined surface at its lower end that descends toward the upstream side of the sleeve 2, and magnetically regulates the regulated developer flow mainly near the descending tip, as well as the regulated developer flow. The flow of the developer is made smooth by flowing out onto the downwardly inclined surface, thereby preventing the accumulation of dust and the like. In FIG. 3(J), a plurality of regulating members 41 and 42 are provided to enable regulation in stages. Also the third
Figure (e) has an inclined surface that descends toward the downstream side of the sleeve 2, and has a plane parallel to the surface of the sleeve 2 at the lower end, so that the developing material flows smoothly into the regulating portion of the regulating member 4. Figure 4(f) to 4(f) shows an example in which a magnetic material is used as a part of the regulating member.
All of the sections up to (k) consist of a non-magnetic section 4a and a magnetic section 4b. The shape and arrangement of the magnetic portion 4b are determined by the developer seed characteristics,
It is selected depending on the rotational speed of the image forming body 1 and/or the sleeve 2, the strength of the magnetic field of the magnet roll, etc.

Although the thickness of the N thickness regulating portion varies depending on the material and shape, it is generally preferable to set it to Wln of 0.5 to 5 mII.

The magnetic materials used for the development MN regulating member 4 shown in FIGS. 3 and 4 above include substances that are strongly magnetized in the direction by a magnetic field, such as metals such as iron, Niacel, and cobalt, or their oxides; Alloys or compounds containing iron, cobalt, nickel, etc. such as elite, magnetite, hematite, etc., or Mn-Cu- which does not contain ferromagnetic substances but becomes ferromagnetic by appropriate heat treatment.
Heusler alloy such as Al or Mn-Cu-3-neck is used.

The non-magnetic material 4 of the regulating member 4 may be plastic, A1. Non-magnetic metals such as Cu, rubber, etc. are used.

Further, the magnetic material 4 may be made of a paramagnetic magnet.

By the way, the various regulating members of the present invention have mechanical layer thickness regulation based on the narrow gap d between the tip of the regulating member and the sleeve surface, and magnetic regulation 1111 based on the strength of the magnetic field I4 between the magnetic roll and the layer thickness regulating member. regulated by. By configuring the regulating member in this way, there are disadvantages that occur when only mechanical regulation is used, such as: (1) It is difficult to uniformly and precisely regulate narrow gaps of 500 μl or less;
2) The developer collides with the regulation plate and creates a vortex, making the developer layer obtained by regulation uneven. (3) The developer flow expands after regulation, making it unexpectedly thick, uneven, and rough. Various disadvantages such as the formation of a developer layer are greatly alleviated, and a uniform thin developer layer necessary for non-contact formation can be obtained.

In the present invention, it is preferable that 5 to 6096 of the amount of developer regulated by the regulation member is due to the magnetic regulation, and therefore the strength of the magnetic field between the magnet roll and the magnetic regulation member is 50 to 700. It is better to

Next, while FIGS. 3 and 4 above are fixed type layer thickness regulating members, the layer thickness regulating member shown in FIG. 5 below includes a magnetic material and has a rotating body that rotates in the opposite direction to the sleeve. Excess developer is caused to flow outward by the rotating body, thereby making it possible to form a thin layer more smoothly than in the case of the above-mentioned tj43 and FIG. 4. In this configuration, since the developer flow is regulated over a relatively wide area of the rotating body surface, the developer flow is affected by j! Uniform layer thickness can be controlled because no undue impact is applied and no vortices occur.

The regulating member shown in FIG. 5 (IJ) rotates the magnetic roll 11 on the surface of the sleeve 2 around the pongee 12.
The developer layer is regulated by a rotating magnetic field, and excess developer is separated and conveyed upward by a magnetic roll 11 rotating in the direction of the arrow and scraped off by a blade 15.

The magnetic roll 11 may be a paramagnetic magnet.

Next, the regulating member shown in Pt55 diagrams (m) and (+1) has a structure in which a non-magnetic sleeve 14 is rotated around the outer periphery of a fixed rolled magnet body 13, and excess developer is removed by the rotating sleeve 14. It is separated and conveyed upward for removal.

In FIG. 5(-) above, the developer conveyed upward by the sleeve 14 is scraped off by the blade 15, but in FIG.
), a blade magnet 16 is provided in place of the blade 15, and the excess developer M is scraped off by the repulsive magnetic field of the magnetic pole of the blade magnet 16, which has the same polarity as the magnetic pole of the rolled magnet 13. The regulating members (t') to (n) above automatically remove intervening foreign substances, which are suitable for forming a thin developing layer, to obtain a more uniform developer layer.

The above is a description of the structure of the developer layer thickness regulating member according to the present invention, and below, two-component development and removal including a microcarrier according to the present invention will be explained.

(Tos -) The toner, which is a component of the two-component developer, is usually prepared by mixing an appropriate amount of a coloring agent and, if necessary, a charge control agent, a mold release agent, etc. in a binder resin, melting, kneading, and cooling. It is obtained by post-pulverization and classification to obtain the desired particle size.

Examples of the buying resin include polyester resin and styrene/acrylic resin.

The polyester resin is obtained by polycondensation of alcohol and carboxylic acid, and the alcohols used include, for example, ethylene glycol, noethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, Fols such as 1,4-butanediol, neopentyl glycol, 1,4-buteneol, 1,4-bis(hydroxymethyl)cyclohexane, and bisphenol A, hydrogenated bis7er/-A1 polyoxyethylenated bisphenol Examples include etherified bisphenols such as A1 polyoxypropylenated bis-7-ethyl A, and dihydric alcohol monomers thereof.

In addition, carboxylic acids include 1, such as maleic acid, 7-maric acid, mesafonic acid, citraconic acid, itaconic acid, glutaconic acid, 7-talic acid, isophthalic acid, terephthalic acid, cyclohexanenocarboxylic acid, succinic acid, 7-nopic acid, Cepatic acid, malonic acid, anhydrides of these acids, dimers of lower alkyl esters and riluic acid, and other divalent compounds
! Mention may be made of acid monomers.

As the polyester resin preferably used in the present invention, it is also suitable to use a polymer containing a component of the above-mentioned trifunctional or higher polyfunctional monomer. Examples of trivalent or higher polyhydric alcohol monomers that are such polyfunctional monomers include sorbitol, 1.2.3.6-hetosantetrol, 1.4-sorbitan, pentaerythritol, and dipentaerythritol. , tripentaerythritol, sitasaccharide, 1.2.4-butanetriol, 1.2.5
-Pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1.3.5-)rihydroxymethylbenzene, to name a few. I can do it. Examples of trivalent or higher polycarboxylic acid monomers include 1.2.4-benzenetricarboxylic acid, 1.3.5-benzenetricarboxylic acid, 1.
, 2,4-cyclohexanetricarboxylic acid, 2,5.7
-su7talentricarboxylic acid, 1.2.4-butanetricarboxylic acid, 1,2゜5-hexanetricarboxylic acid, 1,
3-Nocarboquine-2-methyl-2-methylenecarboxypropane, tetra(methylenecarboxyl)methane, 1.2.7.

8-octane tetracarboxylic acid, empol trimer acid,
and anhydrides of these acids, and others.

The above-mentioned styrene/acrylic resin contains, for example, the α,β-unsaturated ethylenic monomer described in JP-A-50-134652 as a constituent unit, and f
fi weight average molecule ji (M w ) and number average molecule jft
(Mn) ratio (Mw/Mn) value of 3.5 or more (fat can be used).

Specific examples of α,β-unsaturated ethylenic monomers include styrene, 0-methylstyrene, l-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, and 2,4-nomethylstyrene. , p-n-butylstyrene, p-tcrt-butylstyrene, p-n
-hexylstyrene, 9-n-octylstyrene, p-
n-7nylstyrene, p-n-decylstyrene, p-n
-)' Aromatic vinyl monomers such as decylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-nochlorosticine; e.g. methyl acrylate, ethyl acrylate, n-butyl acrylate, acrylic isobutyl acrylate, puavir acrylate, n-octyl acrylate, dodecyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, acrylic W
17! methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, methacrylate Methacrylic acid esters such as acrylic dodecyl, uturyl methacrylate, R2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, diethylaminoethyl methacrylate;
Vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, and vinyl fluoride; vinyl esters such as vinyl acetate, vinyl prot'onate, vinyl benzoate, and buty['nyl]; and others. .

Next, the coloring agents mixed into the toner include carbon black, aniline black, 7-arnet black,
There are black pigments such as lamp black, and blue or cyan pigments such as aniline blue, carfoil blue, methylene blue, and 7-talocyanine blue, and red or magenta dyes such as DuPont Oil Red and Rose Bengal. Yellow pigments include auramine, cutranone, benzine derivatives, etc., and are contained in an amount of 1 to 20 parts by weight per 1100 parts by weight of binder tree rrf.

Furthermore, a charge control agent may be added to control the triboelectricity of the toner.For black toner, a conventionally known general charge control agent may be used, but for chromatic toner, the color tone of the toner may be changed to M. A charge control agent that is white, colorless, or close to colorless and does not cause any damage is selected. Examples of such charge control agents include Vf No. 59-88745 and JP-A No. 59-88.
No. 743, JP-A-59-79256, JP-A-11-1979-
No. 78362, JP-A-59-228259, JP-A-5
Publications No. 9-124344, patent application No. 61-2165
Specification No. 4 (Negative charge control agent) and JP-A-51-9456
No., JP-A-59-204851, JP-A-59-204
No. 850 and JP-A-59-177571 (positive charge tIImm). Such charge control agents are used in toner binder υ (0 to 5 parts per 100iI parts of fat). Contains 1 part.

Next, a release agent is used as necessary to prevent the toner from offsetting to the fixing roller and from adhering to the carrier.

Such mold release agents include, for example, polyolefins, fatty acids,
v! Examples include metal salts, fatty acid esters, partially saponified fatty acid esters, higher fatty acids, higher alcohols, liquid or solid paraffin waxes, 7-mide waxes, polyhydric alcohol esters, silicone esters, aliphatic 70 carbons, and the like.

The above mold release agents can be used alone or in combination of two or more.

Examples of the polyolefin include polypropylene,
JIS resins such as polyethylene and polybutene
The softening point when measured by the ring and ball method specified in K 2521-1960 is 80 to 180°C, preferably 100°C.
~160°C. Said fatty acid Jk! ! Examples of 4-salts include maleic acid and metal salts such as zinc, magnesium, and calcium; stearic acid and metal salts such as zinc, cadmium, barium, lead, iron, 2/kel, cobalt, copper, aluminum, and magnesium. Salt; Dibasic lead stearate; Metal salts of oleic acid with zinc, magnesium, iron, cobalt, copper, lead, calcium, etc.; Metal salts of palmitic acid with aluminum, calcium, etc.; Lead caprylate; Lead caproate Calcium linoleate; Metal salts of ricinoleic acid and zinc, cadmium, etc., and mixtures thereof. Examples of the fatty acid ester include ethyl maleate, butyl maleate, methyl stearate, methyl stearate, cetyl palmitate, and ethylene glyfur montanate. Examples of the partially saponified lff1l17j acid ester include partially saponified calcium esters of montanic acid.

Serious higher fatty acids include, for example, dodecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, sulfuric acid, ricyllic acid, arachidic acid, behenic acid, lignoceric acid, and ceracolein I! Examples of the higher alcohol include dodecyl alcohol, lauryl alcohol, myristyl alcohol, valmityl alcohol, stearyl alcohol, 7-ralkyl alcohol, and behenyl alcohol. Examples of the paraffin wax include natural paraffin, microwax, synthetic paraffin, chlorinated hydrocarbon, etc. Examples of the amide wax include stearic acid amide, oleic acid amide, valmitic acid amide,
Examples include lauryl a17miV1 behenic acid amide, methylene bisstearamide, and ethylene bisstearamide. Examples of the multi-fE+ alcohol ester include glycerin stearate, glycerin phosphorus/late,
Examples include glycerin monobehenate, sorbitan monostearate, propylene glycol more stearate, sorbitan triolate, and the like. Examples of the silicone face include methyl silicone 7 varnish, phenyl silicone varnish, and the like.

Examples of the aliphatic 70a carbon include low-polymerized compounds such as 47-fluorinated ethylene and 67-fluorinated propylene, and fluorine-containing surfactants described in JP-A-53-124428.

The amount of these mold release agents used is 1 to 10 parts by weight per 100 parts by weight of the buying resin.

When the toner is a chromatic toner, the coloring agent affects the performance of the toner, for example, the amount of charge of the toner, so a colored layer with a specific resistance in the range of 104 to 105 ΩCI is selected. Ru. In addition, since it also affects the charge control properties, etc., the charge 11.
1. It is necessary to appropriately select the amount of milling with a punch and its addition amount. ] The toner obtained in this way has a specific resistance of 10 in order to obtain high image quality.
"ΩC@ or more, preferably 10'2 Ωcm or more, more preferably 101 ΩC- or more, and the weight average particle size is 1 to 30μ
It is preferable to use a fine particle toner of m, which is suitable for non-contact development with a thin developer layer to be described later.

(Carrier) The carrier, which is another component of the two-component developer, uses magnetic particles, preferably spherical magnetic particles, as a core material, and a resin solution is dip coated or spray coated on the core material and dried. Alternatively, a coated carrier may be used in which a thin layer of resin is formed by a spray drying method or the like.

1. As the magnetic material for the core material, the same magnetic material as that used for the developer layer thickness regulating member can be used, but Hiro's 7 Elite is preferably used due to its toner transportability, durability, developability, etc. It will be done.

11 As for the characteristics of the core material, the specific resistance is lXl0'~l
Xl0"ΩCIfi, more preferably 1xio' to 1x
1011Ωc111. Saturation magnetization is 10-40 emu/
g, preferably 15 to 30 emu/H,
When it is less than 10C duck u/g, the magnetization of the core material becomes small, the conveyance property decreases, and the image density becomes thin. 40e+Ωu
/g or more, carrier density on the sleeve decreases, development efficiency decreases, and image density decreases. Still, r
G-layer formation becomes difficult. Coercive force is 0.1-1000 e
, a range of 10-700e is most preferable. Below 0.10e, is there a reversal of carrier magnetization? As a result, conveyance performance deteriorates. If it is 1000e or more, the transportability becomes large and carrier scattering tends to occur.

Further, the specific gravity of the core material is 4.0 to 5.5, particularly 4.2 to 5.
0 is preferred. If it is less than 4.0, the carrier will be light and will be easily scattered. If it is 5.5 or more, the conveyance property will deteriorate.

The porosity is preferably 1 to 10%. If it is less than 1%, the sintering temperature will be high, which will increase the time and cost. If it is 105 or more, the strength will be low and the durability of the carrier will be poor.

Styrene-acrylic is the coating resin! I fat, silicone? J (fat, fluororesin, acrylic O (fat), polyester resin, epoxy resin, vinyl chloride/vinyl acetate copolymer, nitrogen-containing resin. Inorganic materials such as glass and ceramics can also be used.

Usually, a resin is used that is soluble in a solvent and can be formed into a film by spray coating, impregnation treatment with a solution, or the like. The thickness of these coatings is 0.1 to 10 μl, preferably 0.3 to 3 μl, and may be set to a value that provides sufficient insulation and stable characteristics.

In addition, when using the resin-coated carrier IJ7, even if the carrier has a small particle size, it has good fluidity, so even if the N thickness is regulated by the layer thickness regulating member, a uniform developer layer can be formed on the sleeve. Moreover, it has good releasability and has the effect that toner does not film on the carrier even when subjected to strong pressure. The carrier thus obtained has a specific resistance of 10'Ωcm or more, preferably 1012ΩC- or more, more preferably 101Ωe1m or more, and preferably has a 50% diameter on a weight basis of usually 20 to 60μ. It is desirable to have the following relational expression between the weight-based 50% diameter (Rμ, ) and the magnetization of the carrier (emu/c@').

The formula is 30≦M≦-8R+150, where 10≦R≦150, preferably 20≦R≦60, and the measurement is carried out under the application of a magnetic field of 1,000 oersteds.

Next, the developer of the present invention is obtained by mixing appropriate amounts of the carrier and toner, but the mixing ratio varies depending on the particle size, that is, the surface area ratio, of the carrier and toner. In particular, the larger the carrier, the more the toner mixing ratio. will be made to reduce the amount of

For example, the ratio St/5c of the total area Sc of carrier to the total area SL of toner in a unit volume of developer = 0.5 to 2
The weight ratio is preferably in the range of 1 part by weight of 5 to 20 parts of toner per 100 ffl parts of carrier.

The resistance value listed above is 0.50ca+2 for particles.
After placing the particles in a container with a cross-sectional area of
This value is obtained by reading the current value when a voltage that generates an electric field of cm is applied.

Moreover, the average particle diameter is a 50% diameter on a weight basis measured with a Coulter Counter (manufactured by Coulter Inc.).

Further, the magnetic body used in FIGS. 3 and 4 according to the present invention may be a magnetic body having a magnetic pole of opposite polarity at a position facing the magnetic pole of the magnet roll.

〔Example〕

EXAMPLES The present invention will be specifically explained below with reference to Examples, but the embodiments of the present invention are not limited thereto.

(Embodiment 1) FIG. 6 is a sectional view of a main part of an image forming apparatus for explaining this embodiment, and the same parts as in FIG. 1 are given the same reference numerals. Reference numeral 20 denotes a non-contact developing device having the same structure as that shown in FIG. 2, and the magnetic layer thickness regulating member shown in FIG. 4(i) is installed as the developer M thickness regulating member 4. 21 is a corona charger, L image exposure, 22 is a pre-transfer exposure lamp, and 23 is a transfer? ! pole, 24 is a separation electrode, p is a transfer paper, 25 is a static eliminator for cleaning, and is a static eliminator electrode 25
m and a static elimination lamp 25b. 26 is cleaning! The device includes a cleaning blade 26a and a bias roller 26b.

Image formation is performed in this apparatus as follows. After the surface of the image forming body 10 is charged with a uniform potential by the corona charger 21, imagewise exposure is performed to form a latent image. This latent image is developed by the developing device J20 under the conditions described below to obtain a toner image. This toner image is transferred@
After being uniformly exposed by the exposure lamp 22, the transfer paper P is transferred onto the transfer # and P conveyed at a predetermined timing by the action of the transfer pole 23, and the transfer paper P is transferred to the image forming body 10 by the action of the separation pole 24.
The toner image is separated from the transfer paper P and further transferred by a fixing device (not shown), and is fixed onto the transfer paper P and discharged outside the machine. On the other hand, the surface of the image forming body 10 after being transferred is charged with the cleaning song static electricity removal! After the static electricity is removed by the electricity removal electrode 25a and the electricity removal lamp 25b of j125, the cleaning 1r112
The toner is cleaned by the blade 26a of No. 6, and the toner that spills out at this time is received by the bias roll 26b which rotates under the application of a bias, and is discharged by the discharge screw conveyor.

Next, the developer used will be explained.

The toner is produced as follows.

Polyester resin U X -K 120p 100
Parts by weight (manufactured by Kako Soup Co., Ltd.) Polypropylene 860p 13 /
/ (manufactured by Sanyo Chemical Industries, Ltd.) Carbon blank Mogul L 10 weight 1 part (Cabot Co., Ltd.) was mixed in a Henschel mixer, thoroughly kneaded at a temperature of 140°C with three rolls, and then allowed to cool. The average particle size is 10μ by the process of coarse grinding, grinding with a diene mill, and classification.
Obtain the mouse colorant particles. This coloring material particle 100fi f
A toner is obtained by adding 0.4 parts by weight of hydrophobic fine silica R-812 (Nippon Aerosil Co., Ltd. 91) to part i and dispersing and mixing in a type mixer.

The main physical properties of this toner are resistivity of approximately 10'4 Ωcm.
, an average particle size of 10 μm, and a specific gravity of 1.2 g/cm 3 .

Create a career as follows! ! be done.

A carrier is obtained by coating the surface of spherical man-zinc M7 elite particles (manufactured by TDK) with a styrene-acrylic resin to a thickness of 1.5 μm using a Subirahuter. The main physical properties are an average particle size of 30μ11, resistivity of 1013Ωcm, magnetization of 85emu/c+a3, and specific gravity of 4.6g/cm'.

Y Chi 10 layers like this! ? ! A desired developer is obtained by mixing Is and 1 part by weight of carrier. If this is sufficiently stirred, the average charge amount of the toner will be about -20 μC/g.

Other image forming conditions are summarized in Table 1.

As a result of repeating image formation 1,000 times under the conditions shown in Table 1, a high-density, clear image was obtained without any occurrence of ground blur.

(Comparative Example) The image forming apparatus shown in FIG. 6 of Example 1 is used, but development 1i
Image formation was performed under the image forming conditions shown in Pt52 table using a one-component developer having the following formulation in place of the two-component developer contained in fi20.

Developer formulation polyester resin U X -K 120p 100
m! j 1 part magnetite powder (average particle size 0.1 μm) 40 parts by weight polypropylene 660. 6 parts by weight Carbon black Mogul L 811 parts Colored particles with an average particle size of 10 μm were obtained using the same method as in Example 1, and 4 mfl of hydrophobic silica R-8120 was added to 100 parts by weight of the colored particles. was added to obtain a developer of this comparative example.

As a result of repeated image formation under the conditions shown in Table 2, there was overall density unevenness from the initial stage, which is presumably because the regulation by the developer layer thickness regulating member was not necessarily uniform.

(Embodiment 2) FIG. 7(A) is a cross-sectional view of the main parts of a multicolor image forming apparatus to explain this embodiment, and FIGS. 6(B) and (C) show the writing device and FIG. 3 is a cross-sectional view showing the developing device.

The multicolor image forming apparatus shown in FIG. 7(a) operates as follows.The image input section IN has an illumination light 'a31, a mirror 32, a lens 33, and a -dimensional color CCD image sensor 34 integrated into a unit. 7) The image input section IN is moved in the direction of arrow X by a drive device (not shown), and the CCD imaging probe 34 reads the document.

The image information read by the image input section IN is sent to the image processing section T.
R is used to convert the data into data suitable for recording.

The laser optical system 36 forms a latent image on the image forming body 1 in the following manner based on the above image data, and this latent image is developed to form a toner image on the image forming body. The surface of the image forming body 1 is uniformly charged by the scorotron electrode 41. Subsequently, the image forming body 1 is irradiated with image exposure light from the laser optical system 36 through the lens in accordance with the recorded data. In this way, an electrostatic latent image is formed. This electrostatic latent image is developed by a developing device A containing yellow toner. This developing device A has the configuration shown in FIG. 6(c) below.

The image forming body 1 on which the toner image has been formed is uniformly charged again by the scorotron electrode and subjected to image exposure according to recorded data of another color component. The formed e-electronic latent image is developed by a developing device fiB containing magenta toner. As a result, a two-color toner image of yellow toner and magenta toner is formed on the image forming body 1. Thereafter, in the same manner, cyan toner and black toner are developed in a superimposed manner by the developing devices c and D, and a four-color toner image is formed on the image forming body 1. Incidentally, all of the surface development devices B, C, and D have the same structure as the development device A.

The multicolor toner image thus obtained is transferred to the exposure lamp 4.
After the charge is removed by step 2 to make it easier to transfer, transfer step 143
The image is transferred onto the recording paper P fed from the paper feeding device 48 in synchronization with the image formation.

The recording paper P is separated from the image forming body 1 by the separation pole 44,
The image is fixed by a fixing device 45. On the other hand, the image forming body 1 has a removal electrode 4
6 and cleaning device 47.

The cleaning device fi47 is a cleaning blade 47a.
and a fur brush 47c. These are kept out of contact with the image forming body 1 during image formation, and when a multicolor image is formed on the image forming body 1, they come into contact with the image forming body 1 after the transfer.
Scrape off any residual toner. Thereafter, the cleaning blade 47a leaves the image forming body 1, and a little later, the brush 71-brush 47c leaves the image forming body 1. fur brush 47c
serves to remove toner remaining on the image forming body 1 when the cleaning blade 47a leaves the image forming body 1.

4F b is a roller that collects the toner scraped off by the blade 47a.

The laser optical system 36 is shown at 37 in Figure 0 in Figure 7 (B).
is a semiconductor laser oscillator, 38 is a rotating polygon mirror, 39 is r
It is a θ lens.

Further, the developing device A shown in FIG. 7(C) has almost the same component structure as the developing device shown in FIG. It has a more compact configuration.

Further, the magnetic plate shown in FIG. 2(b) is used as the developer layer thickness regulating member 4, the magnet roll 3 disposed inside the sleeve 2 is fixed, and the regulating member 4 is connected to the magnetic pole N of the magnet roll 3. are placed facing each other.

The carrier used here was the same as in Example 1.

In addition, the toner is the same black toner as in Example 1,
In other toners, each colorant was used instead of carbon black. In other words, yellow toner contains auramine,
Roguemin B for magenta toner, @ for cyan toner
7ria cyanine is used. Table 3 shows other working conditions in which the mixing ratio of toner and carrier was 1:9 (3! quantity ratio).

When a multicolor image was formed by developing in the order of yellow, magenta, cyan, and black under the conditions shown in Table 3 below, a high-density, well-toned image with no background blur was obtained.

(Example 3) In place of the layer thickness regulating member (i) of Example 1, a layer thickness regulating member (
The same developing device as in Example 1 was used except that the image forming apparatus vcr! shown in FIG. ! Image formation was carried out using Example 1 in the same manner as in Example 1. However, the layer thickness regulating member (■) has a diameter of 15 m.
m and move the sleeve 14 in the direction of the arrow at a circumferential speed of 250+am/se.
e (same circumferential speed as sleeve 2 of the developing roll, but in the opposite direction), and operated with a gap S with sleeve 2 of 100 μm. As a result, soil strength blurring, image unevenness,
A good image without dotted or streaky image defects was obtained.

(Example 4) In this example, the developing device (A) of Example 3 is used.

B T CI D ), the magnetic pole in the developing section of the fixed magnet roll 1 is not provided at a position facing the image forming body 10 , but approximately midway between the N and S magnetic poles is placed on the surface of the image forming body (closest to the sleeve 2 ). A developing device is used, which is provided opposite to the surface).

According to the development vc arrangement of this embodiment, a horizontal magnetic field is formed between adjacent N and S magnetic poles in the development section, and the IWWi latent image on the image forming body 10 is developed with a more uniform and thin developer. It becomes possible to do so.

A color image was formed in the same manner as in Example 2 except that the developing devices Δ, B, C, and D were changed as described above. Results 2.
High-density, clear color images were obtained even after printing 1,000 continuous copies.

〔Effect of the invention〕

As is clear from the above description, the developing device of the present invention can produce high-density, clear images without blurring, and especially when applied to multicolor image formation, can produce clear images with no color turbidity. can get.

[Brief explanation of the drawing]

FIG. 1 is a sectional view illustrating an example of layer thickness regulation according to the present invention, f
jS2 is a cross-sectional view showing an example of the developing vc position of the present invention, FIGS. 3 to 5 are cross-sectional views showing specific examples of the developer layer 77 regulating member that can be used in the present invention, and FIG. 6 is a cross-sectional view showing an example of the developer layer 77 regulating member that can be used in the present invention. 7(a) is a sectional view of essential parts of the image forming apparatus of Example 2, and FIG. 7(b) and 1(c) are
FIG. 2 is a sectional view of a writing device and a first developing device that are incorporated in the image forming apparatus of (b). 1 ---- Image forming body (photosensitive drum) 2 ----
- Sleeve, 3 ---- One magnet roll 4 ----
1. Developer layer thickness regulating member G ---- 1 Stirrer, 7 ---- 1. Toner replenishment roller 9.10 - 1. Bias power source 12. Layer thickness regulating member consisting of a magnetic roll. 13-
--- Fixed magnet body 14 as a further thickness regulating member ---
- Sleeves 20, A, B, C as Mn regulating members
, D -----1 development device 21.41 ----1 charger, L ----1 exposure light 22.42 ----1 pre-transfer exposure lamp 23.43 ----1 transfer device , 24
．． 44-----One separator 25.48-----Pre-cleaning static eliminator 26.47--Cleaning device IN----One image input section, 34------- CCD
Imaging Rinko TR----1 image processing section, 36----1-
IF! Insertion device Fig. 2 Fig. 3 (a) (b) (c) (d) (e) Fig. 4 (f) (g) (h) (i) (j) (k) Fig. 5 (n) Figure 6 Figure 7 (a) Figure 7 (b) Procedural amendment February 25, 1988 Patent Application No. 285305 2, name of the invention Developing device 3, relationship to the blue case in which the amendment is made Patent applicant address: 1-26-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo 1-26-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo 191 Konica Co., Ltd. (Tel: 0425-83-1521) Patent Department 5, of the specification subject to amendment “Detailed description of the invention” column. 6. Contents of amendment The detailed description of the invention will be amended as shown in the attached sheet. Procedural amendment February 26, 1988

Claims (6)

[Claims] (1) A developer container containing a two-component developer consisting of toner and microcarriers, a developer transport carrier that rotates within the container, and a fixed magnet roll disposed inside the developer transport carrier. and a developer layer thickness regulating member, at least a portion of which is made of a magnetic material, provided close to the outer surface of the developer transport carrier, and a latent image formed by the developer transport carrier and the magnetic roll. A developing device characterized in that the thickness of a developer layer conveyed to a surface is regulated under the influence of a magnetic effect acting between the developer layer thickness regulating member and the magnet roll. (2) The developing device according to claim 1, wherein the latent image surface is developed in a non-contact manner under an oscillating electric field generated by applying an alternating current bias to a gap between the latent image surface and the developer transport carrier. . (3) If the frequency of the AC bias exceeds 1KHz
The developing device according to claim 2, wherein the developing device has a peak voltage of 500 V to 4 KV. (4) The developing device according to claim 1, wherein the developer layer on the latent image surface has a layer thickness smaller than the gap between the developer transport carrier and the latent image surface, 500 μm or less, and exceeding 100 μm. . (5) Claim 1, wherein the gap between the developer transport carrier and the layer thickness regulating member is 700 μm or less, and is greater than or equal to the maximum particle size of microcarriers in the two-component developer.
Developing device as described in section. (6) The developing device according to claim 1 or 5, wherein the microcarrier has an average particle size of 15 μm or more and less than 50 μm.