JP2003076131A - Electrophotographic image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic image forming apparatus in which a high quality image without toner fogging is obtained over a long period of time by controlling an amount of toner replenishment to be replenished to a developer carrier by using a toner density or an image density and information on a humidity detecting means. SOLUTION: The electrophotographic image forming apparatus includes a photoreceptor, an electrifying means, an exposure means, a developing means, a transfer means, a fixing means, a toner density detecting means to detect a toner density in a developer, a toner replenishment means to replenish the toner from a toner replenishing device to the developer carrier, a humidity detecting means to detect the humidity of an atmospheric environment, and a control means. The control means controls the amount of toner replenishment of the toner replenishment means at least according to information outputted by the toner density detecting means and information outputted by the humidity detecting means.

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 (hereinafter also simply referred to as an image forming apparatus) such as a copying machine, a printer and a facsimile, and more specifically, it is characterized by controlling a toner replenishment amount. The present invention relates to an image forming apparatus having the same.

[0002]

2. Description of the Related Art In image formation by an electrophotographic method, a photosensitive member is charged by a charging unit, a latent image is formed by an exposing unit, and then a developing bias power source is used to develop a high-voltage developer having the same polarity as the charging polarity on a developer carrying member. A method of applying a bias voltage to adhere toner to the latent image is used.

Since the toner of the developer on the developer carrying member is consumed by adhering to the latent image, the toner is replenished from the toner replenishing device and the toner concentration of the developer is controlled to be constant. .

However, in a low humidity environment (for example, 35R
(H% or less), it is difficult for the carrier and the toner to mix on the developer carrying member. Therefore, when a large amount of toner is replenished rapidly, the carrier and the toner are not mixed well, and the insufficiently charged toner remains in the developer. There was a tendency to end up. This insufficiently charged toner is apt to cause problems such as toner fogging or stain inside the machine due to toner scattering.

In the conventional image forming apparatus, toner is replenished from the toner replenishing device to the developer carrying member depending on the toner concentration in the developer or the image concentration formed on the photosensitive member.
The toner replenishment amount is set in advance, and the toner replenishing device is driven by a supply start signal from the control means to replenish a fixed amount of toner.

In the image forming apparatus having such a structure, the toner replenishment method does not change depending on the toner concentration of the developer, the atmospheric humidity at the time of printing, or the usage time of the developer. It was difficult to obtain a good image without toner fogging from the start of use of the agent to the end of its life.

Further, in order to obtain a high-quality image for a long period of time, maintenance of the image forming apparatus is frequently carried out in order to eliminate problems caused by stains inside the apparatus due to toner (particularly, stains on the wire of the scorotron charger due to scattered toner). I had to.

In particular, when a large amount of high density originals are continuously printed in a low humidity environment, problems such as toner fog and stains inside the machine are likely to occur.

[0009]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above problems, and determines the toner replenishment amount to be replenished to a developer carrier based on the toner density or image density detecting means and the output information of the humidity detecting means. An object of the present invention is to provide an image forming apparatus that can control and obtain a high-quality image without toner fog for a long period of time.

[0010]

As a result of intensive studies on the above problems, the present invention supplies toner to a developer carrier based on the toner density of the developer or the image density of the photoconductor and the atmospheric humidity during printing. Control the amount of toner replenishment
It has been found that by preventing the insufficiently charged toner from remaining in the developer, a good image without toner fogging can be obtained for a long period of time even when the atmospheric humidity during printing is low.

The object of the present invention can be achieved by adopting the following configuration. 1. A photoconductor, a charging unit for applying a surface potential to the photoconductor, an exposing unit for exposing the charged surface of the photoconductor to form a latent image, and the latent image carried on a developer carrier. Developing means for developing with a developer to form a toner image on a photoreceptor, transfer means for transferring the toner image onto a transfer material, fixing means for heating and fixing the transferred toner image, and toner in the developer In an electrophotographic image forming apparatus having a toner density detecting means for detecting a density, a toner supplying means from a toner supplying device to a developer carrying member, a humidity detecting means for detecting a humidity of an ambient environment, and a controlling means, The control means is
An electrophotographic image forming apparatus characterized in that the toner replenishing amount of the toner replenishing means is controlled in accordance with at least output information of the toner concentration detecting means and output information of the humidity detecting means.

2. The control means controls the toner replenishing amount of the toner replenishing means in accordance with at least the developer usage time output information, the toner concentration detecting means output information, and the humidity detecting means output information. 2. The electrophotographic image forming apparatus described in the item 1 above.

3. 3. The electrophotographic image forming apparatus as described in 1 or 2 above, wherein the toner replenishing means replenishes toner by rotating a motor, and the amount of toner replenishment is controlled by the rotation speed of the motor.

4. 4. The electrophotographic image forming apparatus according to any one of items 1 to 3, wherein the toner replenishing amount of the toner replenishing means is controlled by intermittently performing a replenishing operation.

5. The electrophotographic image forming apparatus according to any one of items 1 to 4, wherein the toner replenishing amount of the toner replenishing means is controlled by controlling the maximum replenishing amount per unit time.

6. The electrophotographic image forming apparatus according to any one of items 1 to 5, wherein the developer comprises a toner and a carrier, and the toner is produced by a polymerization method.

7. A photoconductor, a charging unit for applying a surface potential to the photoconductor, an exposing unit for exposing the charged surface of the photoconductor to form a latent image, and the latent image carried on a developer carrier. Developing means for developing with a developer to form a toner image on a photoreceptor, transfer means for transferring the toner image onto a transfer material, fixing means for heating and fixing the transferred toner image, and toner on the photoreceptor In an electrophotographic image forming apparatus having an image density detecting means for detecting an image density, a toner replenishing means from a toner replenishing device to a developer carrying member, a humidity detecting means for detecting the humidity of an ambient environment, and a controlling means, The electrophotographic image forming apparatus, wherein the control means controls the toner replenishing amount of the toner replenishing means in accordance with at least output information of the image density detecting means and output information of the humidity detecting means.

8. The control means controls the toner replenishment amount of the toner replenishing means in accordance with at least the usage time output information of the developer, the output information of the image density detecting means, and the output information of the humidity detecting means. 8. The electrophotographic image forming apparatus described in 7 above.

9. 9. The electrophotographic image forming apparatus as described in 7 or 8 above, wherein the toner replenishing means replenishes toner by rotating a motor, and the toner replenishment amount is controlled by the rotation speed of the motor.

10. The electrophotographic image forming apparatus according to any one of items 7 to 9, wherein the toner replenishment amount of the toner replenishing means is controlled by intermittently performing a replenishing operation.

11. The electrophotographic image forming apparatus according to any one of items 7 to 10, wherein the toner replenishing amount of the toner replenishing unit is controlled by controlling a maximum replenishing amount per unit time.

12. 12. The electrophotographic image forming apparatus according to any one of items 7 to 11, wherein the developer comprises a toner and a carrier, and the toner is produced by a polymerization method.

The present invention will be described in detail below. The toner in the two-component developer is consumed by developing the latent image on the photoconductor with the two-component developer, and the consumed toner equivalent amount is replenished from the toner replenishing device. The replenished toner is mixed with the carrier on the developer carrying member, and the toner is charged.

When the toner is mixed with the carrier on the developer carrying member, the toner is uniformly charged if the replenishment amount of the toner is controlled to be small. In some cases, the toner replenishment cannot keep up with the consumption of the toner, and the toner density decreases, so that a sufficient image density cannot be obtained. On the other hand, if the replenishment amount of the toner is controlled to a large amount so that a high-density image can be obtained even when a high-density original is continuously printed, insufficiently charged toner will remain on the developer carrying member, If insufficiently charged toner adheres to the non-latent image portion on the photoconductor, it causes toner fogging, and if it scatters in the machine, it scatters the scorotron charger and causes image defects.

Particularly in a low-humidity environment, if a large amount of toner is rapidly replenished, a large amount of insufficiently charged toner remains, and toner fog and toner scattering significantly occur due to the insufficiently charged toner.

The image forming apparatus of the present invention detects the toner density information on the developer carrier or the image density information attached on the photoconductor and the humidity detection in order to prevent the image quality from being deteriorated due to the toner fog and the toner scattering in the machine. It is characterized in that the toner replenishment amount of the toner replenishing means is controlled according to the detection information of the means.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing an example of the configuration of the image forming apparatus. In FIG. 1, reference numeral 1 is a control means for controlling the image forming apparatus, and at least a surface potential control section 7, an exposure amount control section 9, a bias potential control section 15, a humidity detection section 20,
The toner replenishment amount control unit 30, the toner concentration control unit 40, and the developer usage time integration unit 24 are controlled.

The surface potential controller 7 controls the voltage of the scorotron charger 5 by the charging high-voltage power supply 6 included in the charging means 4. The control is performed based on the surface potential detected by the surface potential detecting means 11.

The exposure amount control section 9 controls the exposure light amount of the exposure means 8. The control is performed by a method in which current or voltage is variable, a pulse width modulation method, or the like.

In the bias potential controller 15, the developing means 1
The voltage to the developer carrying member 13 is controlled by the developing bias power source 14 included in 0. The control is performed by a method such as changing the current or the voltage.

The humidity detecting section 20 processes information from the humidity detecting means 21 installed near the photoconductor 2 and the developer carrying member 13.

The toner concentration control section 40 processes the information from the toner concentration detecting means 41 for measuring the magnetic permeability or the permittivity of the developer to calculate the toner concentration in the developer.

The developer usage time integration section 24 integrates the number of revolutions or the operating time of the motor 25 for driving the developer carrier (developing magnet roll) and sends the information to the control means 1.

The control means 1 receives an image formation start signal in response to an input signal such as the turning-on of a print switch (not shown) and sends an electric signal to the drive means of a photoconductor drive motor (not shown) to drive the photoconductor 2 and to expose the photoconductor. The charge removal lamp 3 is turned on in order to eliminate the influence of the surface potential of the previous image formed on the body. Next, the surface of the photoconductor 2 is charged by the charging means 4. The charging means 4 comprises a scorotron charger 5 and a charging high voltage power source 6 for applying a voltage to the scorotron charger 5. The output voltage of the charging high-voltage power supply 6 is controlled by the surface potential controller 7, and the surface potential of the photoconductor 2 can be controlled to 0 to -1000 V by changing the grid voltage of the scorotron charger 5.

The photoconductor 2 whose surface is charged by the scorotron charger 5 continues to rotate and reaches a position facing the exposure means 8. As the exposure means 8, a scanning method using a laser exposure system or the like is used. In the exposure means 8, since the exposure light amount can be changed by the exposure amount control section 9, the limit potential from which the surface potential does not decrease from the receiving surface potential of the photoconductor even if the exposure is continued (hereinafter, this potential is saturated exposure. Potential), the latent image is formed by changing the potential level according to the amount of exposure light.

Although the exposure means 8 is a scanning method using a laser exposure system in this embodiment, an exposure method using an LED or the like is also applicable.

The photoconductor 2 on which the latent image is formed continues to rotate and reaches a position facing the non-contact surface potential detecting means 11 arranged between the exposing means 8 and the developing means 10. The surface potential detecting means 11 has a high-voltage detector (not shown), and sends the detected surface potential to the surface potential controller 7 as a signal. Then, the photoconductor 2 enters the developing area 12. A toner image is formed on the latent image by the developing means 10 in the developing area 12. The developing means 10 can control the output voltage thereof from 0 to -1000V by applying a high voltage to the developer carrier 13 that holds and rotationally conveys the two-component developer composed of toner and carrier, and applies a high voltage to the developer carrier 13. It has a developing bias power source 14.

The photoreceptor 2 on which the toner image has been formed by the developing means 10 is further rotated to transfer the toner image onto a recording sheet (not shown) by a transfer means (not shown) in a transfer area (not shown). The recording paper is heated and fixed by a fixing device (not shown), and is discharged to a discharge tray (not shown).

The control means 1 controls the replenishment amount of the toner replenished from the toner replenishing device 31 to the developer carrying member 13 in accordance with the information of the toner concentration control section 40 and the humidity detecting section 20.

Alternatively, in the control means 1, the toner concentration control section 40, the humidity detection section 20, and the developer use time integration section 24 are included.
From the toner replenishing device 31 according to the information of
3 controls the amount of toner to be replenished.

FIG. 2 is a schematic view showing another example of the structure of the image forming apparatus. In FIG. 2, reference numeral 1 is a control unit for controlling the image forming apparatus, which is at least the surface potential control unit 7, the exposure amount control unit 9, the bias potential control unit 15, the humidity detection unit 2.
0, the toner replenishment amount control unit 30, the image density control unit 50, and the developer use time integration unit 24 are controlled.

The surface potential controller 7 controls the voltage of the scorotron charger 5 by the charging high voltage power source 6 included in the charging means 4. The control is based on the surface potential detected by the surface potential detecting means 11.

The exposure amount control unit 9 controls the exposure light amount of the exposure means 8. The control is performed by a method in which current or voltage is variable, a pulse width modulation method, or the like.

The bias potential controller 15 controls the voltage to the developer carrier 13 by the developing bias power source 14 included in the developing bias means 10. The control is performed by a method such as changing the current or the voltage.

The humidity detecting section 20 processes information from the humidity detecting means 21 installed near the photoconductor 2 and the developer carrying member 13.

The image density control section 50 processes the information from the reflection type image density detecting means 51 for measuring the image density on the photoconductor to calculate the toner density in the developer.

In the developer use time integration section 24, the number of revolutions or the operating time of the motor 25 for driving the developer carrier (developing magnet roll) is integrated and the information is sent to the control means 1.

The control means 1 receives an image formation start signal in response to an input signal such as the turning-on of a print switch (not shown) and sends an electric signal to the drive means of a photoconductor drive motor (not shown) to drive the photoconductor 2 and to expose it The charge removal lamp 3 is turned on in order to eliminate the influence of the surface potential of the previous image formed on the body. Next, the surface of the photoconductor 2 is charged by the charging means 4. The charging means 4 comprises a scorotron charger 5 and a charging high voltage power source 6 for applying a voltage to the scorotron charger 5. The output voltage of the charging high-voltage power supply 6 is controlled by the surface potential controller 7, and the surface potential of the photoconductor 2 can be controlled to 0 to -1000 V by changing the grid voltage of the scorotron charger 5.

The photoconductor 2 whose surface is charged by the scorotron charger 5 continues to rotate and reaches a position facing the exposure means 8. As the exposure means 8, a scanning method using a laser exposure system or the like is used. In the exposure means 8, since the exposure light amount can be changed by the exposure amount control section 9, the limit potential from which the surface potential does not decrease from the receiving surface potential of the photoconductor even if the exposure is continued (hereinafter, this potential is saturated exposure. Potential), the latent image is formed by changing the surface potential level according to the exposure light amount.

Although the exposure means 8 is a scanning method using a laser exposure system in this embodiment, an exposure method using an LED or the like is also applicable.

The photoconductor 2 on which the latent image is formed continues to rotate and reaches a position facing the non-contact surface potential detecting means 11 arranged between the exposing means 8 and the developing means 10. The surface potential detecting means 11 has a high-voltage detector (not shown), and sends the detected surface potential to the surface potential controller 7 as a signal. Then, the photoconductor 2 enters the developing area 12. A toner image is formed on the latent image by the developing means 10 in the developing area 12. The developing means 10 can control the output voltage thereof from 0 to -1000V by applying a high voltage to the developer carrier 13 that holds and rotationally conveys the two-component developer composed of toner and carrier, and applies a high voltage to the developer carrier 13. It has a developing bias power source 14.

The photoreceptor 2 on which the toner image has been formed by the developing means 10 further rotates to transfer the toner image onto a recording sheet (not shown) by a transfer means (not shown) in a transfer area (not shown). The recording paper is heated and fixed by a fixing device (not shown), and is discharged to a discharge tray (not shown).

The control means 1 controls the amount of toner to be replenished from the toner replenishing device 31 to the developer carrier 13 in accordance with the information of the image density controller 50 and the humidity detector 20.

Alternatively, in the control means 1, from the toner replenishing device 31 to the developer carrying member 13 in accordance with the information of the image density control unit 50, the humidity detecting unit 20, and the developer use time integrating unit 24.
Controls the amount of toner to be replenished to.

Next, the material according to the present invention will be described in detail. << Toner >> As the toner, a polymerized toner prepared by a polymerization method is preferable.

Since the composition of the polymerized toner is uniform in the toner and the particle diameters of the toner are uniform, the toner is easily mixed with the carrier on the developer carrying member and uniformly charged in a short time. preferable.

The method of producing the polymerized toner will be described below, but the method of production is not limited to this.

As the polymerized toner, resin particles having a number average primary particle diameter of 10 to 500 nm prepared by a suspension polymerization method or an emulsion polymerization method are salted out / fused to prepare secondary particles, and then an organic solvent, Polymerization is performed by adding a flocculant, a polymerization catalyst, etc., and the sphered secondary particles (spherical toner) in the solution having a polymerization rate of 80% are further added with a polymerization catalyst to complete the polymerization. It can be manufactured.

The salting out / fusing means salting out the resin fine particles produced in the polymerization step with an aggregating agent to remove excess dispersants, surfactants and the like, and at the same time, heat fusion to determine the size of the resin particles. It means adjusting.

The number average primary particles can be measured, for example, by a light scattering electrophoretic particle size measuring device "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.).

The volume average particle diameter can be measured with, for example, a Coulter Counter TA-2 type or Coulter Multisizer (manufactured by Coulter Co., Ltd.).

The salting-out / fusion is carried out by mixing resin particles with a dispersion liquid such as a releasing agent or a coloring agent necessary for the constitution of the toner, or a toner constitution of the releasing agent or the coloring agent in the monomer. Number average primary particle size 1 produced by a method such as emulsion polymerization after dispersing the components
It can be carried out by salting out / fusing resin particles of 0 to 500 nm.

That is, various constituent materials such as a colorant and, if necessary, a release agent, a charge control agent, and a polymerization initiator are added to the polymerizable monomer, and a homogenizer, a sand mill, a sand grinder, and an ultrasonic dispersion are added. Various constituent materials are dissolved or dispersed in the polymerizable monomer by a machine or the like. A liquid in which these various constituent materials are dissolved or dispersed is dispersed in oil droplets of a desired size as a toner using a homomixer, a homogenizer or the like in an aqueous medium containing a dispersion stabilizer. afterwards,
Transfer to a reactor equipped with a stirring mechanism equipped with a stirring blade, and heat to advance the polymerization reaction to 80% to form spherical particles (spherical toner). Further, a polymerization catalyst is added to proceed with the polymerization to complete the polymerization. After the polymerization is completed, the dispersion stabilizer is removed, filtered, washed, and dried to prepare a polymerized toner used in the image forming apparatus of the present invention.

As the polymerizable monomer constituting the resin as the binder, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-chlorostyrene. Styrene, 3,4-dichlorostyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene,
Styrenes such as p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, styrene derivatives, and methacrylic acid. Methyl, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, Methacrylic acid ester derivatives such as diethylaminoethyl methacrylate and dimethylaminoethyl methacrylate, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate,
Acrylate ester derivatives such as isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate, olefins such as ethylene, propylene and isobutylene, vinyl chloride, vinylidene chloride , Halogenated vinyls such as vinyl bromide, vinyl fluoride and vinylidene fluoride, vinyl propionate, vinyl acetate, vinyl benzoate and other vinyl esters, vinyl methyl ether, vinyl ethyl ether and other vinyl ethers, vinyl methyl ketone , Vinyl ethyl ketone, vinyl hexyl ketone and other vinyl ketones, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone and other N-vinyl compounds, vinyl naphthalene, vinyl pyridine and other vinyl compounds Acrylonitrile, methacrylonitrile, acrylic acid or methacrylic acid derivatives of acrylamide. Among these, vinyl monomers can be used alone or in combination.

Further, it is more preferable to use, as the polymerizable monomer constituting the resin, those having an ionic dissociative group in combination. For example, those having a substituent such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group as a constituent group of the monomer, and specifically, acrylic acid, methacrylic acid,
Maleic acid, itaconic acid, cinnamic acid, fumaric acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, styrenesulfonic acid, allylsulfosuccinic acid, 2-acrylamido-2-methylpropanesulfonic acid, acid phosphooxyethyl Methacrylate,
3-chloro-2-acid phosphooxypropyl methacrylate and the like can be mentioned.

Further, divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate,
It is also possible to use a polyfunctional vinyl such as neopentyl glycol diacrylate to form a resin having a crosslinked structure.

These polymerizable monomers can be polymerized by using a radical polymerization initiator. In this case, an oil-soluble polymerization initiator can be used in the suspension polymerization method. Examples of the oil-soluble polymerization initiator include 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile and 1,1'-azobis (cyclohexane-1). -Carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile,
Azo-based or diazo-based polymerization initiators such as azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide,
Dicumyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-
Examples include peroxide polymerization initiators such as bis- (4,4-t-butylperoxycyclohexyl) propane and tris- (t-butylperoxy) triazine, and polymer initiators having a peroxide in the side chain. Can be done.

When the emulsion polymerization method is used, a water-soluble radical polymerization initiator can be used. Examples of the water-soluble polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropaneacetic acid salts, azobiscyanovaleric acid and its salts, and hydrogen peroxide.

Examples of the dispersion stabilizer include tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, Examples thereof include calcium sulfate, barium sulfate, bentonite, silica and alumina. In addition, polyvinyl alcohol, gelatin,
Methyl cellulose, sodium dodecylbenzene sulfonate, ethylene oxide adducts, higher alcohol sodium sulfate and the like which are commonly used as surfactants can be used as the dispersion stabilizer.

The polymerized toner contains at least a resin and a colorant, but may contain a releasing agent which is a fixing property improving agent, a charge control agent and the like, if necessary. Further, an external additive composed of inorganic fine particles or organic fine particles may be added to the particles of the polymerized toner containing the above resin and the colorant as main components.

As the colorant used for the polymerized toner, carbon black, dyes, pigments and the like can be optionally used.

As the carbon black, for example, channel black, furnace black, acetylene black, thermal black, lamp black and the like can be used.

Examples of the dye include C.I. I. Solvent Red 1, 49, 52, 58, 63, 11
1, 122, C.I. I. Solvent Yellow 19, 4
4, ibid 77, ibid 79, ibid 81, ibid 82, ibid 93, ibid 9
8, the same 103, the same 104, the same 112, the same 162, C.I.
I. Solvent Blue 25, 36, 60, 70,
No. 93, No. 95, etc. can be used, and a mixture thereof can also be used.

Examples of the pigment include C.I. I. Pigment Red 5, 48: 1, 53: 1, 57: 1, 122, 139, 144, 149, 166, 177, 178, 222, C.I. I. Pigment Orange 31, the same 43, C.I. I. Pigment Yellow 14,
Ibid. 17, ibid. 93, ibid. 94, ibid. 138, C.I. I. Pigment Green 7, C.I. I. Pigment Blue 15: 3, 60 and the like can be used.

The above dyes and pigments can be used alone or in combination. The number average primary particle diameter of the colorant varies depending on the type, but is preferably about 10 to 200 nm.

As a method of adding the colorant, a method of adding the colorant at the stage of polymerizing the monomer and polymerizing it to form colored particles can be used. When the coloring agent is added at the stage of producing the polymer, it is preferable to treat the surface with a coupling agent or the like before use so as not to hinder the radical polymerizability.

Further, low molecular weight polypropylene (number average molecular weight = 1500 to 9000) or low molecular weight polyethylene as a fixability improving agent may be added.

Similarly, various known charge control agents can be used.
Moreover, the thing which can be disperse | distributed in water can be used. Specifically, nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines,
Examples thereof include secondary ammonium salt compounds, azo-based metal complexes, salicylic acid metal salts or metal complexes thereof.

The particles of these charge control agents and fixability improvers have a number average primary particle diameter of 10 to 500 in a dispersed state.
It is preferably about nm.

Further, in the polymerized toner used in the image forming apparatus of the present invention, it is possible to exert more effects by adding fine particles such as inorganic fine particles and organic fine particles as an external additive. The reason for this is presumed to be that the burial and detachment of the external additive can be effectively suppressed, and the effect is remarkable.

As the inorganic fine particles, it is preferable to use inorganic oxide particles such as silica, titania and alumina.
Further, these inorganic fine particles are preferably subjected to a hydrophobic treatment with a silane coupling agent, a titanium coupling agent or the like.

<< Carrier >> As a carrier, for example,
It is possible to use metal particles such as iron, ferrite and magnetite, magnetic particles made of alloys of these metals with metals such as aluminum and lead, or resin-coated magnetic particles obtained by coating the magnetic particles with a resin, but not limited to these. It is not something that will be done. Examples of preferable carriers include resin-coated magnetic particles obtained by coating ferrite particles whose electric resistance is easily controlled with a silicon resin.

<< Two-Component Developer >> As a two-component developer,
It can be prepared by mixing the toner and the carrier with a known mixer.

The toner concentration of the two-component developer is generally controlled to 3 to 10% by mass, though the appropriate range varies depending on the humidity during printing, the usage time of the developer and the like. Generally, if the toner concentration is less than 3% by mass, it is difficult to obtain a high-concentration image, and if it exceeds 10% by mass, toner fogging and toner scattering increase even with sufficient stirring, and high quality images are obtained for a long period of time. Difficult to get images.

<< Photoreceptor >> The photoreceptor is not particularly limited, and known ones can be used. Specifically, a charge generating layer formed on a conductive support, a charge transport layer sequentially laminated, an intermediate layer on the conductive support, a charge generating layer,
Examples thereof include those in which charge transport layers are sequentially laminated, and those in which a surface layer is further laminated on a charge generation layer.

[0087]

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

<Preparation of Toner> 0.055 kg of sodium dodecylbenzenesulfonate was added to 4.0 L of ion-exchanged water.
The solution dissolved in was designated as "anionic surfactant solution A".

0.014 kg of a 10-mol addition product of nonylphenol polyethylene oxide was added to 4.0 L of ion-exchanged water.
The solution dissolved in was designated as "Nonionic surfactant solution B".

A solution prepared by dissolving 223.8 g of potassium persulfate in 12.0 L of ion-exchanged water was designated as "initiator solution C".

In the reaction kettle, add 3.41 of wax emulsion.
Kg, the total amount of "anionic surfactant solution A" and the total amount of "nonionic surfactant solution B" were added, and then "initiator solution C" was added to carry out polymerization to prepare "latex 1-A".

A solution prepared by dissolving 0.055 kg of sodium dodecylbenzenesulfonate in 4.0 L of ion-exchanged pure water was designated as "anionic surfactant solution D".

Further, 0.014 kg of a 10-mol addition product of nonylphenol polyethylene oxide was added to 4.
The solution dissolved in 0 L was designated as "nonionic surfactant solution E".

Potassium persulfate (manufactured by Kanto Chemical Co., Inc.) 200.
A solution prepared by dissolving 7 g in 12.0 L of ion-exchanged water was designated as "initiator solution F".

In the reactor, wax emulsion 3.41 was added.
Kg, the whole amount of "anionic surfactant solution D" and the whole amount of "nonionic surfactant solution E" were added, and then "initiator solution F" was added. Next, styrene 11.0 kg, n-butyl acrylate 4.00 kg, methacrylic acid 1.04
A mixed solution of kg and 9.02 g of t-dodecyl mercaptan was added dropwise and reacted to prepare "latex 1-B".

5.36 kg of sodium chloride as a salting-out agent
Was dissolved in 20.0 L of ion-exchanged water to be referred to as "sodium chloride solution G".

0.90 kg of sodium n-dodecyl sulfate
And 10.0 L of pure water were added and dissolved by stirring. 1.20 kg of carbon black "Regal 330R" (manufactured by Cabot Corporation) was gradually added to this solution, and the mixture was stirred well for 1 hour and then continuously dispersed for 20 hours using a sand grinder (medium type disperser). This is "Colorant dispersion 1".
And

Then, in a reaction kettle, 20.0 kg of "latex 1-A" prepared above was added to "latex 1-B".
5.2 kg, 0.4 kg of “colorant dispersion 1” and 20.0 kg of ion-exchanged water were added and stirred. The liquid is heated with stirring to grow particles, and the average particle size is 6.0.
"Sodium chloride solution G" was added at the stage when the particle size became μm to stop the growth and prepare a "fusion particle dispersion liquid".

Next, 5.0 kg of the above "fusion particle dispersion liquid" was added, and the fusion particles were spheroidized at a liquid temperature of 92 ± 2 ° C while observing the shape change of the fusion particles. went. This was designated as "spherical particle dispersion liquid".

Next, the "spherical particle dispersion liquid" was washed with ion-exchanged water and filtered three times, preliminarily dried using a flash jet dryer, and further dried using a fluidized bed dryer to obtain "black". Particles ".

Hydrophobic silica fine particles were externally added to and mixed with the obtained "black particles" in a Henschel mixer to prepare "polymerized toner".

<Production of Carrier> 100 parts of a silicone resin liquid (silicone SR2406, solid content 20% by mass: manufactured by Toray Industries, Inc.) and 5 parts of γ-aminoethyl-aminopropyltrimethoxysilane dissolved in 300 parts of toluene. A resin liquid for use was prepared. Next, 1000 parts of a ferrite carrier having a volume average particle diameter of 60 μm was put into a rotating cylindrical fluidized bed particle coating device, and the coating resin solution was spray coated under heating conditions at 70 ° C. while flowing. Then, heat treatment was performed at 180 ° C. for 3 hours, crushing and classification were performed to prepare a “silicone resin-coated carrier”.

<Preparation of Two-Component Developer> The above “polymerized toner” and the above “silicone resin-coated carrier” were mixed with a mixer to prepare a “two-component developer” having a toner concentration of 4% by mass.

<Image Forming> Example 1 The image forming apparatus shown in FIG.
"Component developer" was loaded, and the toner was replenished from the toner replenishing device to the developer carrier according to the information from the toner concentration control unit and the humidity detection unit. The toner replenishment amount is a constant replenishment amount per one rotation of the motor of the toner replenishing device, and the toner replenishment cycle is once per second. The time for rotating the motor within one cycle (toner replenishment time ) Was changed and controlled.

In Table 1, the toner replenishment time (s) at each humidity corresponds to the output (V) of the toner density detecting means for which a good result was obtained without toner fogging in the printed image.
Describe the setting conditions of.

The relationship between the toner concentration (mass%) of the developer and the output (V) of the toner concentration detecting means is 1 mass% / 0.
It is 5V.

[0107]

[Table 1]

As shown in Table 1, in a low humidity environment of less than 30% RH in which the replenishment toner is agglomerated with the toner due to toner aggregation, the toner replenishment time is set to be short according to the output value of the toner concentration detecting means. By replenishing the toner, a good image without toner fogging was obtained. Also, 30% R
When the value is H or more, the toner replenishment time is set to be extended according to the output value of the toner concentration detecting means, and even if a large amount of toner is replenished, toner fog does not occur and a high-density good image can be obtained.

Example 2 The image forming apparatus shown in FIG.
"Component developer" was loaded, and the toner was replenished from the toner replenishing device to the developer carrier according to the information from the toner concentration control unit and the humidity detection unit. Regarding the amount of toner replenishment, the number of revolutions of the replenishment motor was changed according to the information of the humidity detection unit, and the toner replenishment time was controlled according to the information of the toner concentration control unit.

Table 2 shows the print image under the conditions set by changing the number of revolutions (rpm) of the replenishment motor corresponding to each humidity and the toner replenishment time (s) according to the output information (V) of the toner concentration detecting means. The toner replenishment amount (mg) for which good results were obtained without toner fogging is described.

The toner replenishment amount (mg) is determined by integrating the motor rotation speed (rpm) and the replenishment time (s).

[0112]

[Table 2]

As shown in Table 2, in a low humidity environment of less than 30% RH in which the mixing property of the replenishment toner is inferior, the rotation speed of the toner replenishment motor is set to be slow and the toner replenishment amount per time is reduced to cause toner fogging. A good image was obtained. Further, at 30% RH or more and less than 50 RH%, the rotation speed of the toner replenishment motor is set to be slightly faster to increase the toner replenishment amount per time. However, it was possible to obtain a high-density good image without toner fogging even with a setting in which the toner replenishment amount per time was increased.

Example 3 The image forming apparatus shown in FIG.
"Component developer" was loaded, and the toner was replenished from the toner replenishing device to the developer carrier according to the information from the image density controller and the humidity detector. The toner replenishment amount is a constant replenishment amount per one rotation of the motor of the toner replenishing device, and the toner replenishment cycle is once per second. The time for rotating the motor within one cycle (toner replenishment time ) Was changed and controlled.

In Table 3, the toner replenishment time (s) at each humidity corresponding to the output (V) of the image density detecting means for which a good result was obtained without causing toner fog in the printed image
Describe the setting conditions of.

[0116]

[Table 3]

As shown in Table 3, in a low humidity environment of less than 30% RH in which the mixing property of the replenishment toner is inferior, the toner replenishment time is set short according to the output value of the image density detecting means, and the toner is not fogged by replenishing the toner. A good image was obtained. Further, at 30% RH or more, even if conditions are set such that the toner replenishment time is extended and a large amount of toner is replenished in accordance with the output value of the image density detection means, toner fog does not occur and a high-density good image can be obtained. .

Example 4 The image forming apparatus shown in FIG.
"Component developer" was loaded, and the toner was replenished from the toner replenishing device to the developer carrier according to the information from the toner concentration control unit and the humidity detection unit. The toner replenishment amount is set such that the replenishment amount per one rotation of the motor of the toner replenishing device is set to a constant condition, and the toner replenishment period is once per second, and the time for rotating the motor within one period ( The toner replenishment time) was changed and controlled.

Table 4 shows the conditions for setting the maximum toner replenishment time (s) at each humidity corresponding to the output (V) of the toner density detecting means which gave a good result without toner fog in the printed image.

[0120]

[Table 4]

If the maximum replenishment amount shown in Table 4 is exceeded, toner fogging or the like will occur, which is not preferable.

[0122]

As demonstrated in the embodiment, the image forming apparatus of the present invention controls the replenishment amount of the toner replenished to the developer carrying member by the toner density or the information of the image density and the humidity detecting means to control the toner fog. It has an excellent effect that a high-quality image free of noise can be obtained for a long time.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating an example of a configuration of an image forming apparatus.

FIG. 2 is a schematic diagram illustrating another example of the configuration of the image forming apparatus.

[Explanation of symbols]

1 control means 2 photoconductor 5 Scorotron charger 6 electrified high voltage power supply 8 Exposure means 10 developing means 11 Surface potential detection means 12 Development area 13 Developer support 14 Development bias power supply 20 Humidity detector 21 Humidity detection means 40 Toner density control unit 41 Toner concentration detecting means 50 Image density controller 51 image density detection means

Claims (12)

[Claims] 1. A photoconductor, a charging unit for applying a surface potential to the photoconductor, an exposing unit for exposing the surface of the photoconductor after charging to form a latent image, and a developer for the latent image. Developing means for developing with a developer carried on a carrier to form a toner image on the photoreceptor, transfer means for transferring the toner image onto a transfer material, and fixing means for heating and fixing the transferred toner image, Toner concentration detecting means for detecting the toner concentration in the developer, toner replenishing means from the toner replenishing device to the developer carrier, and humidity detecting means for detecting the humidity of the ambient environment,
In an electrophotographic image forming apparatus having a control means, the control means controls the toner replenishing amount of the toner replenishing means in accordance with at least output information of the toner density detecting means and output information of the humidity detecting means. And an electrophotographic image forming apparatus. 2. The toner replenishing amount of the toner replenishing means according to at least the use time output information of the developer, the output information of the toner concentration detecting means, and the output information of the humidity detecting means. The electrophotographic image forming apparatus according to claim 1, further comprising: 3. The electronic device according to claim 1, wherein the toner replenishing means replenishes the toner by rotating a motor, and the toner replenishment amount is controlled by the rotation speed of the motor. Photo image forming apparatus. 4. The toner supply amount of the toner supply means is
The electrophotographic image forming apparatus according to claim 1, wherein the electrophotographic image forming apparatus is controlled by intermittently performing a supply operation. 5. The toner replenishment amount of the toner replenishing means is
The electrophotographic image forming apparatus according to any one of claims 1 to 4, wherein the electrophotographic image forming apparatus is performed by controlling a maximum replenishment amount per unit time. 6. The electrophotographic image forming apparatus according to claim 1, wherein the developer comprises a toner and a carrier, and the toner is produced by a polymerization method. 7. A photoconductor, a charging unit for applying a surface potential to the photoconductor, an exposing unit for exposing the surface of the photoconductor after charging to form a latent image, and a developer for the latent image. Developing means for developing with a developer carried on a carrier to form a toner image on the photoreceptor, transfer means for transferring the toner image onto a transfer material, and fixing means for heating and fixing the transferred toner image, Electrophotographic having image density detecting means for detecting the toner image density on the photoconductor, toner supplying means for supplying toner to the developer carrier from the toner supplying device, humidity detecting means for detecting the humidity of the ambient environment, and control means In the image forming apparatus, the control means controls the toner replenishing amount of the toner replenishing means in accordance with at least the output information of the image density detecting means and the output information of the humidity detecting means. Forming equipment. 8. The toner replenishing means of the toner replenishing means is responsive to at least the use time output information of the developer, the output information of the image density detecting means, and the output information of the humidity detecting means. The electrophotographic image forming apparatus according to claim 7, wherein the amount is controlled. 9. The electronic device according to claim 7, wherein the toner replenishing means replenishes the toner by rotating a motor, and the toner replenishment amount is controlled by the rotation speed of the motor. Photo image forming apparatus. 10. The electrophotographic image forming apparatus according to claim 7, wherein the toner replenishing amount of the toner replenishing means is controlled by performing a replenishing operation intermittently. 11. The electrophotographic image forming apparatus according to claim 7, wherein the toner replenishment amount of the toner replenishing means is controlled by controlling the maximum replenishment amount per unit time. apparatus. 12. The electrophotographic image forming apparatus according to claim 7, wherein the developer comprises a toner and a carrier, and the toner is produced by a polymerization method.