JP2001042563A - Image forming method and toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the image forming method and the toner each capable of obtaining images freed of uneven revolution of an electrostatic latent image holder and free from image jitter and high in quality in the image forming method for driving plural image forming parts with a driving device using a gear speed-reducing mechanism and overlaying a monocolor toner image formed on the separate image forming part on the latent image holder onto a holder on an endless conveyer belt. SOLUTION: A toner image is developed on the electrostatic latent image by the development part of the image forming part by a nonmagnetic contact unicomponent developing system, and at the time, a toner has an agglomeration degree of 30-80% and the toner contains an exterior additive having a particle diameter of 30-100 nm in an amount of 0.5 to 10 weight %, and further, another exterior additive having a particle diameter of 5 to 20 nm in an amount of 0.05 to 1.0 weight %.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method, and more particularly, to a method of driving a plurality of image forming units using a driving device using a gear reduction mechanism, and forming an electrostatic latent image in each image forming unit. The present invention relates to an image forming method for superposing a multicolor toner image formed thereon on a holding member conveyed on an endless belt and a toner used for the method.

[0002]

2. Description of the Related Art Generally, in an electrophotographic apparatus, such as a photosensitive drum, a photosensitive belt, or a transfer drum, on which an electrostatic latent image or a toner image is formed, the rotation unevenness is remarkable and image quality is deteriorated. In particular, when a graphic pattern is output, a light and shade stripe pattern (referred to as image jitter) due to rotation unevenness occurs, and image quality is significantly reduced. The cause of the rotation unevenness is due to the accuracy of the power transmission system between the motor and the drum, or backlash. For that reason,
In recent years, electrophotographic devices such as printers and copiers
As shown in Japanese Patent Application No. 62-110015, a direct drive system in which a drum shaft and a motor shaft are directly connected has been adopted without providing an intermediate mechanism such as a gear. However, a drive device using a conventional gear reduction mechanism has advantages that it is much cheaper and easier to manufacture than a direct drive method, so that rotation unevenness in a drive device using a gear reduction mechanism is reduced. Reduction is also being studied, for example, as disclosed in JP-A-5-52282, a method for preventing rotation unevenness by attaching a flywheel to an electrostatic latent image carrier and increasing inertial weight, As shown in No. 5-188725, during exposure to the electrostatic latent image carrier, the developing unit and transfer unit of the electrostatic latent image carrier contact unit are separated, and during further exposure, the operation of the unit is stopped. And a method of providing a brake mechanism on the electrostatic latent image carrier, as shown in JP-A-10-340029.

[0003]

SUMMARY OF THE INVENTION
In the case of 5-52282, it is necessary to increase the torque of the drive motor in proportion to the weight of the photoreceptor portion, leading to an increase in cost and an increase in the weight of the machine body. Japanese Patent Application Laid-Open No. 5-188725 requires that a separating device be provided, which increases the number of parts, increases costs, and requires that exposure, development, and transfer processes be performed at different timings. However, the drawback that the printing speed decreases is inevitable. In addition, JP 10
The method of reducing the uneven rotation of the brake mechanism and the like described in JP-340029 leads to an increase in the load on the entire machine. In recent years, using a plurality of developing units such as a color copying machine, an endless belt has been used to transfer a multicolor toner image to each developing unit. In the case of an image forming method of superimposing on a carrier conveyed above, a simple and simple alternative method of reducing rotation unevenness is required because the load on the entire machine is increased and the miniaturization of the machine is hindered. ing.

The present invention has been made in view of such conventional problems, and a plurality of image forming units are driven by a driving device using a gear reduction mechanism, and each of the image forming units is electrostatically driven. In an image forming method in which a monochromatic toner image on a latent image carrier is superimposed on a carrier conveyed on an endless belt, it is possible to obtain a high-quality image without rotation unevenness of the electrostatic latent image carrier and no image jitter. It is an object of the present invention to provide an image forming method and a toner that can be used.

[0005]

The present inventors drive a plurality of image forming units with a driving device using a gear reduction mechanism,
An image forming method in which a single-color toner image is superimposed on a carrier conveyed on an endless belt in each image forming unit, wherein a developing unit in the image forming unit develops the toner image by a non-magnetic contact one-component developing method It has been found that a high-quality image free of image jitter can be obtained by the image forming method and the toner, wherein the toner has an agglomeration degree represented by the following formula of 30 to 80%. Reached the present invention.

If the cohesion degree is less than 30%, the image jitter cannot be reduced, and if it exceeds 80%, the transfer rate decreases.

The reason why image jitter can be reduced by using a toner having an agglomeration degree of 30% or more is not clear, but the contact portion between the electrostatic latent image carrier and the toner carrier, that is, both are carried in the so-called development area. It is considered that the load of the toner carrier on the electrostatic latent image carrier is reduced because the toner layer sandwiched between the bodies is sparse.

(Image Forming Apparatus) FIG. 1 shows an example of an image forming apparatus according to an embodiment of the present invention,
1 schematically shows the configuration of a four-tandem tandem-type full-color copying machine (hereinafter simply referred to as a copying machine) capable of printing a full-color image in one pass. This copier includes electrostatic latent image carriers 1Y, 1M, 1C, and 1 corresponding to visible images of four colors of yellow, magenta, cyan, and black, respectively.
It has four sets of electrophotographic image forming units 10Y, 10M, 10C, and 10Bk for forming on the surface of Bk.

Each of the image forming units 10Y, 10M, 10C, 1
Since 0Bk has substantially the same configuration, the image forming unit 10Y for yellow disposed on the most upstream side in the transport direction will be described as a representative.

That is, the image forming section 10Y for yellow
Is provided with an electrostatic latent image carrier 1Y as an image carrier rotatably brought into contact with the conveyor belt 21 and a developing device 4Y at a substantially central position, and is driven by a driving device using a gear reduction mechanism.

Around the periphery of the electrostatic latent image carrier 1Y, a contact charging device 2Y for charging the surface of the electrostatic latent image carrier 1Y to a predetermined potential, converts the charged drum surface into a color-separated image signal. Exposure device 3Y that forms an electrostatic latent image on the surface of the drum based on the exposure, and supplies a yellow toner to the electrostatic latent image formed on the surface of the drum to develop the image. Transfer roller 5Y for transferring the transferred toner image onto recording paper P, cleaner blade 6Y for removing the residual toner remaining on the surface of electrostatic latent image carrier 1Y without being transferred, and surface of electrostatic latent image carrier 1Y The static elimination lamps 7Y for removing the electric charges remaining in the hopper are sequentially arranged.

Electrostatic latent image carrier 1Y causing image jitter
The rotation unevenness of the contact charging device 2 applies a load by contacting around the electrostatic latent image carrier 1Y in the above configuration, that is, the contact charging device 2
When the load torque combined from the developing sleeve 40Y of the developing device 4Y, the endless belt pressed from behind and coming into contact with the transfer roller 5Y, and the cleaner blade 6Y increases, the rotational driving system of the electrostatic latent image carrier 1Y exists. Caused by backlash.

The magenta image forming section 10M, the cyan image forming section 10C, and the black image forming section 10Bk have the same configuration as the above-described yellow image forming section 10Y, and have the same relationship with respect to rotation unevenness. To establish. Note that the load torque is strongly affected by the bite amount between the electrostatic latent image carrier and the developing roller, and there is a phenomenon that when the bite amount is increased, rotation unevenness increases.

In the figure, 20 is a transport mechanism, 21 is a transport belt, 22 is a drive roller, 24 is a driven roller, 27 is a belt cleaner, 34 is a polygon mirror, 40 is a paper feed mechanism,
50 is a fixing device.

(Toner Aggregation Degree) The aggregation degree was determined by measuring as follows. First, a 75 μm mesh sieve from the top, 45
A 3-μm meshed sieve and a 22-μm meshed sieve stacked in three stages are set on the cohesion degree measuring unit of a powder tester made by Hosokawa Micron, and set so that the vertical amplitude is 1.0 mm. Then, gently put 2.0 g of the sample into the top sieve,
After vibrating up and down for 30 seconds, weigh the remaining amount of sample on each sieve,
The aggregation degree is calculated by the following equation.

[0016] Remaining amount of toner on opening 74 μm sieve (g) / 2 × 100 (a) ・ Remaining amount of toner on opening 44 μm sieve (g) / 2 × 100 × 3/5 (b) Remaining amount of toner on opening 22 μm sieve (g) / 2 × 100 × １ ／ (c) Aggregation degree (%) = (a) + (b) + (c) Here, toner used in the present invention Regarding the production method and materials, all known ones are possible.

As the binder resin, polystyrene,
Polymers of styrene such as poly-p-chlorostyrene and polyvinyltoluene and their substituted products; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer Styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-
Butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethacrylic acid Methyl copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer Coalescence, styrene-
Styrene-based copolymers such as maleic ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, Examples thereof include polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, and aromatic petroleum resin, which can be used alone or in combination.

As the coloring agent, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (1
0G, 5G, G), cadmium yellow, yellow iron oxide, ocher, graphite, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow ( G, G
R), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Tan, Lead Zhu, Cadmium Red, Cad Muum Mercury Red, Antimony Vermilion, Permanent Red 4R, Para Red, Phisaed Red, Parachlor Ortho Nitroaniline Red, Risor Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine Min BS, Permanent Red (F2R, F4R, FRL, FRL)
L, F4RH), Fast Scarlet VD, Belcan Fast Rubin B, Brilliant Scarlet G, Lisor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F
2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Museum, Eosin Lake,
Rhodamine lake B, rhodamine lake Y, alizarin lake, thioindigo red B, thioindigo maroon, oil red, quinacridone red, pyrazolone red, polyazo red, chrome vermilion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue , Alkaline blue lake, peacock blue lake, Victoria blue lake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indanthrene blue (R
S, BC), indigo, ultramarine, navy blue, anthraquinone blue, fast violet B, methyl violet lake, cobalt violet, manganese violet, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Anthraquinone Green, Titanium Oxide, Zinc White, Lithobon and mixtures thereof can be used. The amount used is generally 0.1 to 50 parts by weight based on 100 parts by weight of the binder resin.

The toner of the present invention may contain a charge control agent, if necessary. As the charge control agent, any known charge control agents can be used. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified) Quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds,
Tungsten alone or compound, fluorine-based activator, metal salt of salicylic acid, metal salt of salicylic acid derivative and the like. Specifically, bontron 03 of a nigrosine dye, bontron P-51 of a quaternary ammonium salt, bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid-based metal complex, and E-82 of a salicylic acid-based metal complex 84, phenolic condensate E-89 (all manufactured by Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-
302, TP-415 (manufactured by Hodogaya Chemical Industry Co., Ltd.),
Copy charge PSY VP2 of quaternary ammonium salt
038, copy blue P of triphenylmethane derivative
R, copy charge of quaternary ammonium salt NEGV
P2036, Copy Charge NX VP434 (above, manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (manufactured by Nippon Carlit), copper phthalocyanine, perylene, quinacridone, azo pigments, other sulfonic acid groups, carboxyl groups And high molecular compounds having a functional group such as quaternary ammonium salts.

In the present invention, the amount of the charge control agent used is determined by the type of binder resin, the presence or absence of additives used as required, and the toner production method including the dispersion method, and is uniquely limited. However, preferably, 0.1 to 100 parts by weight of the binder resin
Used in the range of 10 parts by weight. Preferably, the range is 2 to 5 parts by weight. If the amount exceeds 10 parts by weight, the chargeability of the toner is too large, and the effect of the main charge control agent is reduced.
The electrostatic attraction with the developing roller increases, which causes a decrease in the fluidity of the developer and a decrease in image density.

Further, in order to obtain the above-mentioned cohesion degree range of the toner, the toner can be obtained without containing an additive. However, when the external additive having a particle size of 30 to 100 nm is contained at 0.5 to 10% by weight, It has been found that the uniformity of the developing roller toner layer is improved, and the image quality can be uniform even if the cohesion is poor. The particle size referred to here is a number average particle size, which is also determined from a photograph obtained by a transmission electron microscope.

As the external additive having a particle size of 30 to 100 nm, conventionally known materials can be used. Specific examples include silica, titanium dioxide, aluminum oxide, zinc oxide, and magnesium oxide. Examples of those preferably used in the present invention include MOX80 (average particle diameter, about 30 nm) manufactured by Nippon Aerosil Co., Ltd.
50 (average particle diameter, about 40 nm) and TT600 (average particle diameter, about 40 nm), manufactured by Idemitsu Kosan Co., Ltd., IT-PB (average particle diameter, about 40 nm) and IT-PC (average particle diameter,
About 60 nm), manufactured by Fuji Titanium Industry Co., Ltd., TAF110A
(Average particle size, about 40-50 nm) and TAF510
(Average particle diameter, about 40 to 50 nm) and the like can be conveniently used. When used as an electrophotographic toner, these inorganic fine particles may be used alone or in combination of two or more.

Further, in order to suppress environmental fluctuation of the degree of aggregation, the additive is preferably subjected to a hydrophobic treatment, and is used after being treated with dimethyldichlorosilane, dimethylpolysiloxane, hexamethyldisilazane or the like.

Further, not only 0.5 to 10 wt% of an external additive having a particle size of 30 to 100 nm but also an external additive having a particle size of 5 to 20 nm is used.
It is thought that by adding 0.05 to 1.0 wt% of the external additive in addition, it is possible to secure minute development uniformity, but it is possible to obtain an image without image blur and graininess. I found out.

As the external additive having a particle size of 5 to 20 nm, Si
Inorganic fine powders selected from O ₂ , SnO ₂ , TiO ₂ , ZrO ₂ , ZnO and Al ₂ O ₃ are used, and those subjected to a hydrophobic treatment are preferable.

The external additive may have an average particle diameter of 0.1 to
1.0 μm resin particles may be used together. As the insulating resin used for the resin particles, the same resin as the binder resin used for the toner described above can be used, and the spray drying method, the suspension polymerization method, the emulsion polymerization method, the soap-free polymerization method, the seed polymerization method,
A method capable of producing spherical fine particles, such as a mechanical pulverization method, can be used. Among them, a soap-free polymerization method, which has an advantage that there is no residual emulsifier and thus a polymer having a narrow particle size distribution can be obtained without inhibiting the chargeability of the toner, is exemplified. But is not particularly limited.

As the resin particles used in the present invention, methyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, N-
It is preferable to use a resin synthesized from a composition containing monomers such as methyl-N-phenylaminoethyl methacrylate, diethylaminoethyl methacrylamide, dimethylaminoethyl methacrylamide, 4-vinylpyridine, and 2-vinylpyridine. .

The weight average diameter and the particle size distribution were measured at an aperture diameter of 100 μm using a Coulter Counter TAII manufactured by Coulter Corporation.

The linear velocity of the electrostatic latent image carrier of each image forming unit is 20 to 150 mm / sec, and the linear velocity ratio between the electrostatic latent image carrier and the developing roller is 1.0 to 2.0 times ( This is particularly effective when the ratio is (linear velocity with respect to the electrostatic latent image carrier). The amount of penetration of the developing roller into the electrostatic latent image carrier is 20 to 100 μm.
m is preferred.

When the bite amount is less than 20 μm, the end of the electrostatic latent image carrier is out of contact with the developing roller due to the deflection of the developing roller, causing image loss. When it is more than 100 μm, the load torque increases. For some reasons, image jitter suddenly worsens.

Preferably, the linear velocity of the electrostatic latent image carrier of each of the developing units is 40 to 100 mm / sec, and the linear velocity ratio between the electrostatic latent image carrier and the developing roller is 1.0 to 1.6. The image forming method is characterized in that the developing roller has a depth of 30 to 60 [mu] m with respect to the electrostatic latent image carrier.

[Evaluation Items] (Image Jitter) Image jitter was evaluated by a print quality evaluation system (RT2000, manufactured by Yarman KK). The evaluation sample was a sample in which a black and white pair line composed of two dots arranged in parallel with the long side of the A4 size paper was continuous. The two-dot line in this case is 84.6 μm.
m. The center position of the line on the pattern is measured, the center position interval is determined, and the jitter ratio (%) = (standard deviation) / (average value) × from the average value and standard deviation.
It was determined by 100. The measurement width was 20 cm.

(Halftone Uniformity) A continuous halftone image consisting of one dot writing and one dot blank was output, and the uniformity of the image was compared with a step sample. Rank
1 is lowest, rank 5 is highest. Evaluation was made as a four-color superimposed image.

(Image Graininess) A continuous halftone image consisting of two-dot writing and two-dot blanks was output, and the graininess of the image was compared with a step sample. Rank 1 is lowest and rank 5 is highest. Evaluation was made as a 4-color superimposed image.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 Common Material for Each Color Polyol Resin 100 parts Mn: 3600 Mw / Mn: 4.2 Tg: 60 ° C. Softening Point: 110 ° C. Charge Control Agent Zinc Salicylate Derivative (Bontron E84, Orient Chemical) 2 parts for each color Material Yellow toner 1 Colorant Disazo yellow pigment (CI Pigment Yellow 17) 5 parts Magenta toner 1 Colorant quinacridone magenta pigment (CI Pigment Red 122) 4 parts Cyan toner 1 Colorant Copper phthalocyanine blue pigment (C I. Pigment Blue 15) 2 parts Black toner 1 Colorant carbon black 6 parts

The mixture having the above composition is melt-kneaded by a roll mill, cooled, coarsely pulverized by a hammer mill, and finely pulverized by a jet mill to classify the fine powder.
The weight average is 10.5, 10.3, 10.2, 10.6
μm of each color toner was obtained. In addition, the cohesion of the toner is
Y, M, C and Bk were respectively 61, 65, 58 and 63%.

When this toner was evaluated by the machine shown in FIG. 1, an image having no image jitter but poor halftone uniformity was obtained. At this time, the ratio between the linear speed of the photosensitive member and the linear speed of the developing roller was 100 mm / sec and 1.3 times.

Example 2 Material Common to Each Color Polyester Resin 100 parts Mn: 4100 Mw / Mn: 5.5 Tg: 62 ° C. Softening Point: 110 ° C. Oxidation: 9 Charge Control Agent Zinc Salicylate Derivative (Bontron E84, Orient Chemical) 2 Part Color-Specific Materials Yellow Toner 2 Colorant Disazo Yellow Pigment (CI Pigment Yellow 17) 5 Parts Magenta Toner 2 Colorant Quinacridone Magenta Pigment Toner (CI Pigment Red 122) 4 Parts Cyan Toner 2 Colorant Copper Phthalocyanine Blue pigment (CI Pigment Blue 15) 2 parts Black toner 2 Colorant carbon black 6 parts

The mixture having the above composition is melt-kneaded with a roll mill, cooled, coarsely ground with a hammer mill, and finely ground with a jet mill, and the fine powder obtained is weight averaged for each of Y, M, C and Bk. 100 parts of the fine powder obtained by classifying the particles having a particle size of 9.1, 9.2, 9.3, and 9.0 μm was added to R made by Nippon Aerosil
X50 (40 nm, hexamethyldisilazane-treated silica) was added in an amount of 0.8 part and mixed with a mixer to obtain a toner of each color.

The degree of aggregation of this toner is represented by Y, M, C, Bk
It was 71, 74, 77, 72% for each. When this toner was evaluated by the machine shown in FIG. 1, an image having no image jitter and having excellent halftone uniformity was obtained. However, the graininess of the image was poor. The ratio of the linear velocity of the photosensitive member to the linear velocity of the developing roller at that time was 50 mm / sec.
It was 2.2 times.

Example 3 The same kneading formulation as in Example 2 was pulverized and classified to obtain Y, M,
The weight average particle diameters of C and Bk are 7.0, 6.9,
Fine powders of 6.8 and 7.1 μm were obtained. This fine powder 100
For the part, NY50 (30 nm,
2.0 parts of dimethylpolysiloxane-treated silica) and 0.4 parts of R972 (16 nm, dimethyldichlorosilane-treated silica) manufactured by Nippon Aerosil Co., Ltd. were added and mixed with a mixer to obtain toners of each color.

The degree of aggregation of the toner is Y, M, C, Bk
These were 49, 45, 52, and 44%, respectively, and were images having no problems in image jitter, halftone uniformity, and image granularity. The ratio between the linear velocity of the photosensitive member and the linear velocity of the developing roller at that time was 70 mm / sec, 1.1 times.

Example 4 The same kneading formulation as in Example 1 was pulverized and classified to obtain Y, M,
The weight average particle diameters of C and Bk are 11.5 and 1 respectively.
100 parts by weight of fine powder having a particle size of 1.4, 11.6, 11.3 μm and 8 parts by weight of fine powder obtained by treating dimethylpolysiloxane with titanium oxide having an average particle diameter of 70 nm and R812 (7 nm, manufactured by Nippon Aerosil Co., Ltd.) , Trimethylsilyl group-treated silica) was added and mixed with a mixer to obtain toners of respective colors.

The degree of aggregation of the toner is represented by Y, M, C, and Bk.
The images were 31, 35, 32, and 33%, respectively, and were images having no problems in image jitter, halftone uniformity, and image granularity. The ratio between the linear velocity of the photosensitive member and the linear velocity of the developing roller at that time was 25 mm / sec, 1.05 times.

Example 5 The same kneading formulation as in Example 2 was pulverized and classified to obtain Y, M,
The weight average particle diameters of C and Bk are 8.5, 8.
100 parts by weight of fine powder having a particle size of 4,8.6, 8.5 μm were mixed with OX50 (average particle size: 40 n) manufactured by Nippon Aerosil Co., Ltd.
m) 3.0 parts by weight of the silica fine powder and 0.75 parts of hexamethyldisilazane-treated product of α-alumina (average particle diameter: 20 nm) were added and mixed with a mixer to obtain toners of each color.

The degree of aggregation of the toner is represented by Y, M, C, Bk
These were 65, 63, 67, and 66%, respectively, and were images having no problems in image jitter, halftone uniformity, and image granularity. The ratio of the linear velocity of the photosensitive member to that of the developing roller at that time was 170 mm / sec, 1.2 times.

Comparative Example 1 The same fine powder as in Example 3 (identical from kneading to pulverization and classification)
1.2 parts of R974 (12 nm, dimethyldichlorosilane-treated silica) manufactured by Nippon Aerosil Co., Ltd. was added and mixed with a mixer to obtain toner of each color.

The degree of aggregation of the toner is represented by Y, M, C, Bk
The results were 5.5, 5.8, 5.6, and 5.4%, respectively, and the image jitter was poor. The ratio between the linear velocity of the photosensitive member and the linear velocity of the developing roller at that time was 57 mm / sec and 1.4 times.

Comparative Example 2 The same fine powder as in Example 1 (the same from kneading to grinding and classification)
To this was added 1.0 part of a spherical ceramic (120 nm) treated with dimethylpolysiloxane manufactured by Tokuyama Co., Ltd., and mixed with a mixer to obtain a toner of each color.

The degree of aggregation of the toner is represented by Y, M, C, and Bk.
They were 95, 98, 93, and 96%, respectively, and there was no image jitter, but the transfer rate was as low as 70%. In addition,
At that time, the ratio of the linear velocity of the photosensitive member to the linear velocity of the developing roller was 70 mm /
sec, 1.8 times. The above is summarized in the following table.

[0052]

[Table 1]

[0053]

As described above, since the image forming method and the toner of the present invention have the above-described functions, the rotation of the output electrostatic latent image carrier can be prevented from being uneven.
High quality images without image jitter can be formed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a color copying machine as an image forming apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 1Y, 1M, 1C, 1Bk ... electrostatic latent image carrier, 2Y, 2M, 2C, 2Bk ... charging device, 3Y, 3M, 3C, 3Bk ... exposure device, 4Y, 4M, 4C, 4Bk ... developing device, 5Y 5M, 5C, 5Bk: transfer roller, 6Y, 6M, 6C, 6Bk: cleaning blade, 7Y, 7M, 7C, 7Bk: static elimination lamp, 10Y, 10M, 10C, 10Bk: image forming unit, 20: transport mechanism, 21 ... Conveying belt, 22: drive roller, 24: driven roller, 27: belt cleaner, 34: polygon mirror, 40: paper feed mechanism, 50: fixing device, P: recording paper.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Shinichi Kuramoto, 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company, Ltd. (72) Inventor Yuji Yamashita 1-3-6, Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Osamu Uchinokura 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Masae Nakamura 4-1-1 Kamikadanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Limited (72) Inventor Takashi Yamamoto 4-1-1, Kamidadanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Limited (72) Shoichi Kinoshita 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture No. Fujitsu Limited (72) Inventor Yoshimichi Katagiri 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa F-term within Fujitsu Limited (reference) 2 H005 AA08 CA12 CA26 CB07 CB13 EA05 EA07 EA10 FA07 2H030 AA01 AD01 BB23 BB53 2H077 AD02 AD06 EA14 EA15 GA13

Claims (6)

[Claims] A single-color toner image developed on an electrostatic latent image of each image forming unit is conveyed onto an endless belt having a plurality of image forming units driven by a driving device using a gear reduction mechanism. An image forming method in which an image is formed by superimposing an image on a carrier, wherein a developing unit of the image forming unit develops a toner image on an electrostatic latent image by a non-magnetic contact one-component developing method; An image forming method, wherein the degree of aggregation is 30 to 80%. 2. The image forming method according to claim 1, wherein the toner used in claim 1 contains 0.5 to 10 wt% of an external additive having a particle size of 30 to 100 nm. 3. The toner according to claim 1, further comprising 0.5 to 10 wt% of an external additive having a particle size of 30 to 100 nm.
Further, 0.05 to 1.0 of an external additive having a particle size of 5 to 20 nm is added.
wt. 4. The electrostatic latent image carrier according to claim 1, wherein the linear velocity of the electrostatic latent image carrier is 20 to 150 mm / sec, and the linear velocity ratio between the electrostatic latent image carrier and the developing roller is 1.0. ~
2. An image forming method, wherein the magnification is 2.0 times (the linear velocity of the electrostatic latent image bearing member). 5. The method according to claim 1, wherein the toner used is:
0.5 to 10 wt% of external additive having a particle size of 30 to 100 nm
A toner characterized by containing. 6. The method according to claim 1, wherein the toner used is:
0.5 to 10 wt. Of external additive having a particle size of 30 to 100 nm
%, And an external additive having a particle size of 5-20 nm is 0.05-
A toner characterized by containing 1.0 wt%.