JP2002229314A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device in which developer remaining at the inside of a developer cartridge is easily led to a developing tank. SOLUTION: A transfer belt 6 and an electrifying roller 2 are released from a photoreceptor 1 by a timing other than needed by attaching/detaching operation. Vibration caused by the attaching/detaching operation is propagated to the developer cartridge 14, and the fluidity of the developer remaining inside without dropping is enhanced, thereby the developer drops to the developing tank 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus such as a copying machine, a facsimile, and a printer.

[0002]

2. Description of the Related Art In an image forming apparatus provided with a developing device using a two-component developer, a developer cartridge having an opening sealed to prevent the developer from spilling during transportation. The developer used in the developing device is stored in advance, the seal of the developer cartridge is peeled off when starting use of the image forming apparatus, the developer is dropped into the tank of the developing device, and the developer is transported and used. There is.

In such an image forming apparatus, it is necessary to arrange a developer cartridge above the developing apparatus. However, due to demands for downsizing of the apparatus, the space for arranging the developer cartridge is limited. It is difficult to secure space for installing cartridges. Therefore, at present, it is necessary to adopt a complicated shape in order to secure a sufficient capacity, and it is not always possible to adopt a developer cartridge shape suitable for dropping the developer from the developer cartridge into the developing tank.

Accordingly, an object of the present invention is to provide an image forming apparatus which can solve the above-mentioned conventional problems and can easily guide the developer remaining in a developer cartridge to a developing tank.

[0005]

According to a first aspect of the present invention, there is provided an image forming apparatus including a developer cartridge, the image forming apparatus including a developer cartridge. An operating means for shaking the developer remaining in the developer cartridge when the developer is conveyed is provided.

According to a second aspect of the present invention, in order to achieve the above object, in the image forming apparatus of the first aspect, the operating means is means for performing a contact / separation operation of the transfer belt unit. And

According to a third aspect of the present invention, in order to achieve the above object, in the image forming apparatus of the first aspect, the operating means is means for performing a contact / separation operation of the charging roller. I do.

According to a fourth aspect of the present invention, in order to achieve the above object, in the image forming apparatus of the first aspect, the operating means is means for performing a reverse rotation operation of the photoconductor driving device. And

According to a fifth aspect of the present invention, in order to achieve the above object, in the image forming apparatus of the first aspect, the operating means is means for performing a reverse operation of the developing drive device. I do.

According to a sixth aspect of the present invention, there is provided an image forming apparatus according to any one of the first to fifth aspects, wherein the developer used has a weight average diameter of 4 to 15%.
μm.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a main part of an embodiment of an image forming apparatus according to the present invention. In this embodiment, the photosensitive member 1, the charging roller 2 serving as a charging unit, the cleaning unit, and the developing unit are configured as one cartridge.

A writing means (not shown) and a writing position 3 are provided on the photosensitive member 1 uniformly charged by the charging roller 2.
A latent image is formed optically, and a visualized image of the toner is formed by the developing means 4. The toner image formed on the photoreceptor 1 is transferred onto a transfer sheet conveyed through a pair of registration rollers 5 by a transfer belt 6 as a transfer unit. The transfer paper on which the toner image has been transferred is conveyed by a transfer belt 6, where the image is fixed by a fixing unit 7, and discharged out of the apparatus.

The untransferred toner on the photoconductor 1 that has not been transferred onto the transfer paper is scraped off the photoconductor 1 by the cleaning blade 8. The residual charge on the photoreceptor 1 is neutralized by a neutralization lamp (not shown, the position of a neutralization light is indicated by an arrow 9) as a neutralization means, and is prepared for the next image forming operation.

The untransferred toner scraped off by the cleaning blade 8 is sent to the toner conveying means 11 by the toner collecting blade 10 and sent to the near side by the toner conveying means 11 (a collecting coil in the illustrated embodiment). . The toner sent to the near side is returned to the near side of the developing unit 4 through a collected toner conveying path (described later) and reused.

The developing means 4 includes a developing sleeve 12 and a paddle 1.
The untransferred toner returned to the front side of the developing unit and the new toner similarly dropped to the front side by a conveyance path (described later) from the toner supply unit are taken into the conveyance screw unit inside the paddle 13. It is conveyed to the back side and is sent from the back side to the front side together with the developer by a spiral on the outer periphery of the paddle 13 and circulates.

Next, the arrangement of the developer cartridge 14 will be described. In the present embodiment, the developer cartridge 14 is disposed on the developing tank 4 in front of the photoconductor 1. FIG. 2 shows a cross-sectional view of this part. In FIG.
When the removable seal member 15 provided at the lowermost portion of the developer cartridge 14 is peeled off, the developer cartridge 1 is removed.
The developer 16 contained in the container 4 is dropped into the developing tank 4. At this time, the developer 17 contained in the region with a relatively small inclination cannot drop into the developing tank 4 by its own weight, and may remain in the developer cartridge 14.

Referring back to FIG. 1, the transfer belt 6 and the charging roller 2
Will be described. The transfer belt 6 and the charging roller 2 are released from the photosensitive member 1 by a contact / separation operation at an unnecessary timing to avoid unnecessary idling.
The transfer belt 6 is at the position shown in the figure at the time of image formation.
When the image formation is completed, the transfer paper (not shown) is transferred to the transfer belt 6.
When transported further downstream, it is released from the photoreceptor 1 to a position 6 'in the figure by a contact / separation device (not shown). Similarly, the charging roller 2 operates at the illustrated position during image formation. However, when the charging timing has passed, a contact / separation device (not shown) is used.
Is released from the photoreceptor 1 to the position 2 'in the figure. The vibration generated by this contact / separation operation is
The developer 17 is transmitted to the developer tank 4 and the fluidity of the developer 17 described with reference to FIG.

In the image forming apparatus, in order to remove foreign matter such as paper dust attached to the tip of the cleaning blade 8, a reverse rotation operation of slightly rotating the photosensitive member 1 when the machine is stopped may be performed. Vibration occurs in the image forming apparatus due to torque fluctuation when switching from normal rotation to reverse rotation. Alternatively, the same vibration is generated even if the paddle 13 of the developing device is reversed. This vibration causes the developer cartridge 1
4 and the fluidity of the developer 17 described with reference to FIG.
Falling down to.

When the weight average diameter of the developer 17 is 4 to 15 μm, the resolution of the obtained image is improved. Developer 17
Is measured by the following procedure. First, 0.1 to 5 ml of a surfactant (preferably an alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution. Here, the electrolyte is prepared by preparing an approximately 1% NaCl aqueous solution using primary sodium chloride, and for example, ISOTON-II (manufactured by Coulter Inc.) can be used.

Here, 2 to 20 mg of a measurement sample is further added. The electrolyte in which the sample was suspended was mixed with an ultrasonic
The dispersion process is performed for one minute, and the volume distribution and the number distribution are calculated by measuring the volume and the number of the toner particles or the toner by using the measuring device with an aperture of 100 μm as the aperture. From the obtained distributions, the weight average particle diameter of the toner (D4), can be determined and the number average particle diameter.

As the channels, 2.00 to 2.52
μm, 2.52 to 3.17 μm, 3.17 to
4. Less than 4.00 μm, 4.00 to less than 5.04 μm,
04 to less than 6.35 µm, 6.35 to less than 8.00 µm, 8.00 to less than 10.08 µm, 10.08 to 1
Less than 2.70 μm, 12.70 to less than 16.00 μm,
16.00 to less than 20.20 μm, 20.20 to 25.m.
Less than 40 μm, 25.40 to less than 32.00 μm, 3
Thirteen channels of 2.00 to less than 40.30 μm are used, and particles having a particle size of 2.00 μm or more to less than 40.30 μm are targeted.

The material constituting the developer is described as being applicable to both one-component and two-component developers. Toner-
> Carrier: Materials such as a binder resin and a colorant that constitute the toner are listed below. The ratio of the binder resin to the entire toner is 75% to 93%, the colorant is 3% to 10%, the release agent is 3% to 8%, and the other components are 1% to 7%.

Examples of the binder resin to be used include, for example, polystyrene, poly-p-chlorostyrene, homopolymers of styrene and its substituted substances such as polyvinyltoluene, styrene-p-chlorostyrene copolymer, styrene-vinyl Toluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, Styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone and the like can be mentioned.

As the colorant, conventionally known inorganic or organic dyes / pigments can be used. For example, carbon black, aniline black, acetylene black, naphthol yellow, hansa yellow, rhodun lake, alizarin lake, Bengala, phthalocyanine blue, and induslen blue.

If necessary, a magnetic material can be used as a coloring agent. As magnetic materials, magnetite, γ-iron oxide, ferrite iron, iron oxide such as excess ferrite, magnetic metal such as iron, cobalt, nickel, iron oxide or magnetic metal, and cobalt, tin, titanium, copper, lead, A composite metal oxide alloy or a mixture with a metal such as zinc, magnesium, manganese, aluminum, or silicon may be used.

These magnetic particles preferably have an average particle size in the range of 0.05 to 1.0 μm, more preferably in the range of 0.1 to 0.6 μm, and still more preferably 0.1 to 0.6 μm. It is better to be within the range of 0.4 μm. These magnetic particles preferably have a BET specific surface area measured by a nitrogen adsorption method in the range of 1 to 20 m ² / g, particularly in the range of 2.5 to 12 m ² / g, and have a Mohs hardness of 5 to 5 m ² / g. 7 is preferable. The shapes of the magnetic particles include octahedron, hexahedron, sphere,
There are needles and scales, but octahedrons, hexahedrons, and spheres with little anisotropy are preferred.

When used as a magnetic toner, the magnetic toner particles containing a magnetic material preferably contain the magnetic material in an amount of 10 to 150 parts by weight, preferably 20 to 120 parts by weight, based on 100 parts by weight of the binder resin.

In the toner of the present invention, a small amount of an additive can be used within a range that does not substantially adversely affect the toner. Examples of the additive include a lubricant such as Teflon (registered trademark) powder, zinc stearate powder, polyvinylidene fluoride powder, cerium oxide powder, silicon carbide powder, and strontium titanate powder, for example, titanium oxide powder, Fluidity-imparting or anti-caking agents such as aluminum oxide powder, for example, carbon black powder,
Examples thereof include a conductivity imparting agent such as zinc oxide powder and tin oxide powder, and organic or inorganic fine particles of opposite polarity.

Further, a releasing agent may be added to improve the fixing property and the like. Examples of the release agent include paraffin wax and its derivatives, microcrystalline wax and its derivatives, Fischer-Tropsch wax and its derivatives, polyolefin wax and its derivatives, and carnauba wax and its derivatives. Derivatives include oxides, block copolymers with vinyl monomers, and graft-modified vinyl monomers. In addition, alcohols, fatty acids, acid amides, esters, ketones, hydrogenated castor oil and derivatives thereof, vegetable waxes, animal waxes, mineral waxes, and petrolactam can also be used.

As a charge control agent for controlling the toner to be negatively charged, for example, organometallic complexes and chelate compounds are effective, and monoazo metal complexes, acetylacetone metal complexes,
An aromatic hydroxycarboxylic acid-based metal complex and an aromatic dicarboxylic acid-based metal complex are exemplified. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, their anhydrides, their esters, and phenol derivatives such as bisphenol.

Examples of the charge control agent for controlling the toner to have a positive charge include a modified product of nigrosine and a fatty acid metal salt, and tributylbenzylammonium-1-hydroxy-4-.
Quaternary ammonium salts such as naphthosulfonate, tetrabutylammonium tetrafluoroborate, and onium salts such as phosphonium salts, which are analogs thereof; lake pigments thereof; triphenylmethane dyes; Examples thereof include phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, and ferrocyanide. The number average particle size of these particulate charge control agents is preferably 4 μm
Or less, more preferably 3 μm or less.

When these charge control agents are internally added to the toner particles, the toner particles are preferably 0.1 to 20 parts by mass, more preferably 0.1 to 20 parts by mass, based on 100 parts by mass of the binder resin. It is good to contain 2 to 10 parts by mass.

The toner produced according to the present invention may contain, if necessary, a generally used additive for toner, for example, a fluidizing agent such as colloidal silica, titanium oxide,
Metal oxides such as aluminum oxide, abrasives such as silicon carbide, and lubricants such as fatty acid metal salts may be contained.

The inorganic fine powder is preferably used in an amount of 0.1 to 2% by weight based on the toner. If it is less than 0.1% by weight,
If the effect of improving toner aggregation is poor, and if it exceeds 2% by weight, there is a tendency that problems such as toner scattering between fine lines, contamination inside the apparatus, scratches and abrasion of the photoreceptor, and the like tend to occur.

As a method of mixing the additive with the toner,
A conventionally known method may be used, and mixing can be performed by a device such as a Henschel mixer or a speed kneader. As a method for producing a toner kneading and cooling after the toner powder may be a conventionally known method, for example, by kneading and cooling, which was ground with a jet mill, obtained by classifying.

The toner for developing an electrostatic image produced by the present invention can be used as a dry one-component developer and a dry two-component developer. When used as a two-component developer, the mixing ratio of the toner and the carrier is generally about 0.5 to 6.0 parts by weight of the toner per 100 parts by weight of the carrier. When used as a dry two-component developer, the amount of the carrier and the toner of the present invention used is such that the toner particles adhere to the carrier surface of the carrier particles and have a surface area of 30 to 90%.
%, It is preferable to mix both particles.

As the core particles of the carrier constituting the developer in the present invention, conventionally known particles may be used, for example, iron,
Examples include ferromagnetic metals such as cobalt and nickel, alloys and compounds such as magnetite, hematite, and ferrite, and composites of the ferromagnetic fine particles and a resin.

The carrier used in the present invention is preferably coated on its surface with a resin for the purpose of increasing the durability. Examples of the resin forming the coating layer include polyethylene, polypropylene, chlorinated polyethylene, polyolefin resins such as chlorosulfonated polyethylene,
Polyvinyl and polyvinylidene-based resins such as polystyrene, acrylic (for example, polymethyl methacrylate), polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether, and polybiriketone, and vinyl chloride-vinyl acetate copolymer , A silicone resin comprising an organosiloxane bond or a modified product thereof (for example, a modified product of alkyd resin, polyester resin, epoxy resin, polyurethane, etc.), polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene Such as fluorine resins, polyamides, polyesters, polyurethanes, polycarbonates, amino resins such as urea-formaldehyde resins, and epoxy resins. It is. Of these, silicone resins or modified products thereof, and fluorine resins, particularly silicone resins or modified products thereof are preferred in terms of preventing toner spent.

As a method for forming the coating layer, the coating layer forming liquid may be applied to the surface of the carrier core particles by a method such as a spraying method or an immersion method as in the prior art. The thickness of the coating layer is 0.1 to 2
0 μm is preferred.

[0040]

EXAMPLE A production example as a two-component developer will be described. First, 100 parts by weight of a polyester resin (weight average particle diameter 300 μm, softening temperature 80.2 ° C.) 10 parts by weight of carbon black 5 parts by weight of polypropylene (weight average particle diameter 180 μm) 2 parts by weight of a quaternary ammonium salt The mixture was melt-kneaded, then pulverized and classified, and further, 0.3 parts by weight of hydrophobic silica was mixed with 100 parts by weight of the base colored particles to obtain a toner having an average particle size of 9.0 μm. Further, 2 parts by weight of polyvinyl alcohol and 60 parts by weight of water were placed in a ball mill and mixed for 12 hours with respect to 100 parts by weight of magnetite prepared by a wet method to prepare a magnetite slurry. The slurry was spray-granulated with a spray dryer to obtain spherical particles. The particles were fired at a temperature of 1000 ° C. for 3 hours in a nitrogen atmosphere and then cooled to obtain core particles 1. Silicone resin solution 100 parts by weight Toluene 100 parts by weight 15 parts by weight of γ-aminopropyltrimethoxysilane 20 parts by weight of carbon black The above mixture was dispersed for 20 minutes using a homomixer to prepare coating layer forming liquid 1. This coating layer forming liquid was coated on a surface of 1,000 parts by weight of core particles 1 using a fluidized bed type coating apparatus to obtain a silicone resin-coated carrier. A two-component developer was prepared by mixing 2.5 parts by weight of the toner with 97.5 parts by weight of the magnetic carrier.

[0041]

As described above, the image forming apparatus according to the first aspect of the present invention is provided with the operating means for shaking the developer remaining in the developer cartridge when the developer is transported from the developer cartridge to the developing tank. Therefore, there is an effect that the developer remaining in the developer cartridge can be easily guided to the developing tank.

According to the image forming apparatus of the present invention, as described above, since the operating means also serves as a means for performing the contact / separation operation of the transfer belt unit or the like, in addition to the above-mentioned common effects, a dedicated actuator is provided. Vibration can be applied to the developer cartridge without increasing the size of the developer cartridge, and the vibration can guide the developer remaining in the developer cartridge to the developing tank. This has the effect of reducing unnecessary costs.

According to the image forming apparatus of the present invention, as described above, the weight average diameter of the developer is set to 4 to 15 μm. There is.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a main part of an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a cross-sectional view of a portion of the apparatus of FIG. 1 where a developer cartridge is disposed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging roller 3 Writing position 4 Developing means 5 Registration roller pair 6 Transfer belt 7 Fixing means 8 Cleaning blade 9 Static elimination light position 10 Toner collecting blade 11 Toner conveying means 12 Developing sleeve 13 Paddle 14 Developer cartridge 15 Sealant 16 , 17 Developer

Claims (6)

[Claims] An image forming apparatus provided with a developer cartridge, further comprising an operation unit for shaking off the developer remaining in the developer cartridge when the developer is transported from the developer cartridge to a developing tank. An image forming apparatus comprising: 2. An image forming apparatus according to claim 1, wherein said operating means is means for performing a contact / separation operation of the transfer belt unit. 3. The image forming apparatus according to claim 1, wherein said operating means is means for performing a contact / separation operation of a charging roller. 4. An image forming apparatus according to claim 1, wherein said operating means is means for performing a reverse rotation operation of the photoconductor driving device. 5. An image forming apparatus according to claim 1, wherein said operating means is means for performing a reverse rotation operation of the developing drive device. 6. The image forming apparatus according to claim 1, wherein the developer used has a weight average diameter of 4-1.
An image forming apparatus having a size of 5 μm.