JP2014178601A - Image forming apparatus refreshment method, image forming apparatus, and process cartridge - Google Patents

Abstract

In an electrophotographic system, an image forming method is provided that avoids degradation of print image quality due to background stains, toner dropping, and the like.
An electrostatic latent image carrier that carries an electrostatic latent image, a developer carrier that carries a developer that develops the electrostatic latent image, and a toner that is supplied to the developer carrier. In an image forming apparatus including a developer supply member, the photoreceptor surface potential, which is a potential difference between the surface potential of the electrostatic latent image carrier and the surface potential of the developer carrier during the non-printing operation, is the above-described value during the printing operation. A bias voltage is applied to at least one of the electrostatic latent image carrier and the developer carrier so as to be larger than the photoreceptor surface potential, and the deteriorated toner contained in the toner is consumed.
[Selection] Figure 2

Description

  The present invention relates to an image forming apparatus refresh method, an image forming apparatus, and a process cartridge.

The electrophotographic development methods are roughly classified into dry development methods and wet development methods, and the dry development methods are further classified into a one-component development method and a two-component development method.
The two-component development system uses a developer in which toner and magnetic particles called carriers are mixed at an appropriate weight ratio to impart charge to the toner, and the toner is appropriately charged by friction between the two. In this method, the toner is electrostatically attached to the photoreceptor. In contrast, the one-component development method is a method in which an appropriate charge amount is directly applied to the toner itself without using the carrier.

Since the image forming apparatus has been widely used by general users, a technology that can cope with cost reduction, long life, miniaturization, and high speed has been increasingly demanded.
The one-component development type image forming apparatus is excellent in terms of downsizing and low cost, but with further downsizing, parts used tend to be smaller, compared to large machines. In addition, the layout of the functional members is more difficult.

In order to cope with the long life of the apparatus, it is necessary to reduce the wear caused by the durability of the functional member to be used as much as possible. For example, in a photoconductor as an image carrier, a member in charging, developing, transferring, and cleaning means It is necessary to consider surface wear due to contact with the surface. Although it is known to provide a lubricant application member to suppress surface wear of the photoconductor, when the apparatus is downsized and the photoconductor is accordingly downsized, the lubricant application member is laid out. I can't.
Therefore, recently, means for reducing the surface friction of the photosensitive member by adding an external component added with a lubricant component such as silicone oil to the toner is known (for example, see Patent Document 1).

  As the life of the image forming apparatus has been extended, process cartridges that can be attached to and detached from the image forming apparatus have come to be used. However, if the toner that can be used for a long period of time is stored in the process cartridge, the process cartridge becomes large and the main body size of the image forming apparatus becomes large. Therefore, recently, a method has been proposed in which a small amount of toner is put into the process cartridge and the toner is supplemented with a toner cartridge. By doing so, it is not necessary to fill a large amount of the toner at a time, and if the toner runs out, the user can replace the toner cartridge and make up for the toner. Both cost reduction can be achieved.

  However, in the toner added with the external additive component to which the conventional lubricant component is added, the adhesion between the toners is increased, and the fluidity of the toner is deteriorated as compared with the conventional toners. For this reason, it is easy to be stressed in the process cartridge, and the toner thin layer on the developing roller is likely to be disturbed, so that background contamination and toner drop (color loss) are likely to occur.

  Further, in the toner cartridge replenishment method, a large difference occurs in the charge amount distribution between the residual toner subjected to stress in the process cartridge and the new toner replenished from the toner cartridge. It was difficult to maintain. For this reason, in the toner cartridge replenishment method, when the old and new toners are circulated, when the mixing ratio of the old and new toners needs to be kept within a certain range, or when printing at a low printing rate is continued, the retention of the deteriorated toners In order to suppress this, it is necessary to consume the deteriorated toner by controlling to forcibly print the toner at a timing other than printing and sweep it to the outside (see, for example, Patent Documents 2 to 4).

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention provides a method for avoiding deterioration of print image quality due to background stains, toner loss (color loss), etc., even when toner with reduced fluidity is used in an image forming apparatus. Objective.

Means for solving the problems are as follows. That is,
An electrostatic latent image carrier that carries an electrostatic latent image, a developer carrier that contains toner and carries a developer that develops the electrostatic latent image, and a development that supplies the toner to the developer carrier In the image forming apparatus having the agent supply member, the image forming apparatus refresh method for consuming the deteriorated toner contained in the toner during the non-printing operation,
The potential difference between the surface potential of the electrostatic latent image carrier and the surface potential of the developer carrier during non-printing operation (surface potential of the electrostatic latent image carrier (V) −surface potential of the developer carrier ( V)) the electrostatic latent image carrier surface potential is larger than the electrostatic latent image carrier surface potential during the printing operation, and
In a non-printing operation, the potential difference between the surface potential of the developer carrier and the surface potential of the developer supply member (surface potential of developer carrier (V) −surface potential of developer supply member (V)) A certain developer carrier surface potential is larger than the developer carrier surface potential during the printing operation.
An image forming apparatus refreshing method comprising applying a bias voltage to at least one of the electrostatic latent image carrier, the developer carrier, and the developer supply member.

  According to the present invention, the above-mentioned problems can be solved and the above-mentioned object can be achieved, and even in the case of using a toner having reduced fluidity or the like in the image forming apparatus, the background stain or the toner drop (color It is possible to provide a method for avoiding deterioration of the print image quality due to omission or the like.

FIG. 1 is a schematic view showing an example of an image forming apparatus of the present invention. FIG. 2 is a schematic view showing an example of the process cartridge of the present invention.

(Image forming apparatus refresh method and image forming apparatus)
An image forming apparatus refresh method according to the present invention includes an electrostatic latent image carrier (hereinafter also referred to as “photosensitive member”) that carries an electrostatic latent image, and a developer that develops the electrostatic latent image. A developer carrier (hereinafter sometimes referred to as “developing roller”) that carries the developer, and a developer supply member (hereinafter also referred to as “supply roller”) that supplies toner to the developer carrier. An image forming apparatus refresh method for executing a consumption operation of deteriorated toner in a non-printing operation (hereinafter, sometimes referred to as “non-image forming process”).
The image forming apparatus refresh method of the present invention includes a refresh process, and further includes other processes appropriately selected as necessary.
In the refreshing step, the electrostatic latent image carrier surface potential during the non-printing operation is greater than the electrostatic latent image carrier surface potential during the printing operation (hereinafter sometimes referred to as “image forming process”). And so that
The developer carrier surface potential during non-printing operation is larger than the developer carrier surface potential during printing operation.
A bias voltage is applied to at least one of the electrostatic latent image carrier, the developer carrier, and the developer supply member.

  The image forming apparatus refresh method of the present invention can be suitably implemented by the image forming apparatus of the present invention. Specifically, the application of the bias voltage in the image forming apparatus refresh method is the bias voltage in the image forming apparatus. It can implement suitably with an application means.

The image forming apparatus of the present invention includes an electrostatic latent image carrier, a developer carrier, a developer supply member, and a bias voltage application unit, and further includes other units as necessary. It becomes.
The electrostatic latent image carrier is not particularly limited as long as it can carry an electrostatic latent image, and can be appropriately selected according to the purpose. Examples thereof include a photoreceptor (photosensitive drum).
The developer carrying member is not particularly limited as long as it can carry the developer, and can be appropriately selected according to the purpose. Examples thereof include a developing roller and a developing brush.
The developer supply member is not particularly limited as long as the developer can be supplied, and can be appropriately selected according to the purpose. Examples thereof include a supply roller and a supply brush.
As the bias voltage applying means, the electrostatic latent image carrier surface potential during a non-printing operation is larger than the electrostatic latent image carrier surface potential during a printing operation, and during the non-printing operation. At least one of the electrostatic latent image carrier, the developer carrier, and the developer supply member so that the surface potential of the developer carrier is larger than the surface potential of the developer carrier during a printing operation. As long as a bias voltage can be applied to the image forming device, there is no particular limitation, and it can be appropriately selected according to the purpose, and may be provided independently in the image forming apparatus, or the electrostatic latent image carrier, The developer carrying member and the developer supply member may be incorporated in the developer carrying member and the developer supply member.

There is no restriction | limiting in particular as said other means, According to the objective, it can select suitably, For example, a charging means, an exposure means, a transfer means, a fixing means, etc. are mentioned.
The charging means is not particularly limited as long as the electrostatic latent image carrier can be charged, and can be appropriately selected according to the purpose. For example, a known contact charger or a non-contact contact charger Is mentioned.
The exposure unit is not particularly limited and may be appropriately selected depending on the intended purpose as long as the imagewise exposure can be performed on the surface of the electrostatic latent image carrier charged by the charging unit. Can do.
The transfer unit is not particularly limited and may be appropriately selected depending on the intended purpose. However, a visible image obtained by developing the electrostatic latent image formed on the electrostatic latent image carrier is recorded on the recording medium side. It is preferable to have at least a transfer device for peeling and charging.
The fixing unit is not particularly limited and may be appropriately selected depending on the purpose. However, a known heating and pressing unit is preferable, and the heating and pressing unit includes a combination of a heating roller and a pressing roller, A combination of a heating roller, a pressure roller, and an endless belt can be used.

The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier with the charging unit and then performing imagewise exposure with the exposure unit.
In the formation of a visible image by development, a toner layer is formed on a developing roller which is the developer carrying member, and the toner layer is conveyed so as to be in contact with the photosensitive drum which is the electrostatic latent image carrying member. Thus, the electrostatic latent image on the photosensitive drum is developed.
The toner is mechanically supplied to a supply roller which is the developer supply member. The toner supplied from the supply roller and deposited on the developing roller is formed into a uniform thin layer by passing through a developer layer regulating member provided so as to contact the surface of the photosensitive drum. Charged. The electrostatic latent image formed on the electrostatic latent image carrier is developed by attaching the toner charged by the developing means in the developing region to become a toner image.

-Surface potential of electrostatic latent image carrier-
The surface potential of the electrostatic latent image carrier (hereinafter sometimes referred to as “photoreceptor surface potential” or “background potential”) refers to the surface potential of the electrostatic latent image carrier and the surface of the developer carrier. The potential difference from the potential (surface potential (V) of electrostatic latent image carrier-surface potential (V) of developer carrier).
More specifically, the electrostatic latent image carrier surface potential is a non-exposed portion (non-printing portion) potential (charging potential: Vd) on the surface of the electrostatic latent image carrier (photoconductor), and the developer. It shows the potential difference (Vd (V) −Vb (V)) with the surface potential of the carrier (development applied voltage: Vb).

The measurement of the non-exposed portion potential of the electrostatic latent image carrier and the surface potential of the developer carrier is performed by, for example, measuring a surface potential meter on the surface of each of the electrostatic latent image carrier and the developer carrier. By installing (for example, Model 344, manufactured by TREK Co., Ltd.), the average surface potential of the non-exposed portion of the electrostatic latent image carrier and the average surface potential of the surface of the developer carrier can be measured.
Each of the average surface potentials matches the set value of the surface potential of the non-exposed portion of the electrostatic latent image carrier and the set value of the surface potential of the developer carrier.

  The surface potential of the electrostatic latent image carrier is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably −700 V to −200 V, more preferably −600 V to −300 V.

  The surface potential of the developer carrying member is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably −250 V to 0 V, more preferably −200 V to −50 V.

  The relationship between the electrostatic latent image carrier surface potential (Pa) during the non-printing operation and the electrostatic latent image carrier surface potential (Pb) during the printing operation is expressed by the electrostatic latent image during the non-printing operation. There is no particular limitation as long as the carrier surface potential (Pa) is larger than the electrostatic latent image carrier surface potential (Pb) at the time of the printing operation to the same charge polarity as the toner charge polarity. The potential difference (Pa (V) −Pb (V)) is preferably 100 V or higher, and more preferably 150 V or higher. When the potential difference (Pa (V) −Pb (V)) is 100 V or more, the electrostatic latent image is more selectively transferred from the developer carrier to the deteriorated toner during the non-printing operation. This is preferable in that it is developed (discharged) onto a carrier.

-Deteriorated toner-
The deteriorated toner is generated in the process of toner consumption in the image forming apparatus, and its potential is lower than the charge potential of normal toner (non-deteriorated toner) (for example, 30 of the charge potential of normal toner). % Charge potential) or a toner having a charge polarity opposite to the charge potential of normal toner (non-deteriorated toner).

When toner of uniform polarity is used, if all the toners have a uniform polarity, the toner is not developed on the electrostatic latent image carrier in the non-printing portion, and background stains do not occur. .
However, for example, when (-) polarity toner is used, the actual toner has a distribution of charge amount, and the toner has a low charge amount even in (+) polarity or (-) polarity (the deteriorated toner). And the electrostatic latent image carrier in some non-printing parts is also developed (background stain). The deteriorated toner that causes the background stain is removed by performing a normal refresh operation.

  The surface potential of the electrostatic latent image carrier during the non-printing operation is not particularly limited and can be appropriately selected according to the purpose, but is 400 V or more on the same charge polarity side as the toner charge polarity. Is preferred.

  For example, in one embodiment of the image forming apparatus refresh method of the present invention, the electrostatic latent image carrier is arranged so that undeteriorated (−) polarity toner (non-degraded toner) is not discharged as much as possible in the refresh step. The surface potential is increased to the minus side compared with the time of the printing operation, and the (+) polarity toner or the low (−) polarity toner (corresponding to the deteriorated toner) is more forcedly applied from the developer carrier to the static electricity. It is developed (discharged) onto the electrostatic latent image carrier.

  Here, in the non-printing operation, in order to increase the surface potential of the electrostatic latent image carrier to the minus side compared to the time of the printing operation, the bias voltage applying unit is configured to reduce the surface potential of the electrostatic latent image carrier. The value may be changed larger or smaller than the value of the surface potential at the time of the printing operation, and the surface potential value of the developer carrying member may be changed by the bias voltage applying unit to the surface at the time of the printing operation. The potential value may be changed larger or smaller. Further, at the time of the non-printing operation, the bias voltage application means sets both the surface potential value of the electrostatic latent image carrier and the surface potential of the developer carrier to values at the time of the printing operation. It may be changed from large to small.

-Developer carrier surface potential-
The developer carrier surface potential (hereinafter also referred to as “developing roller surface potential”) is a potential difference between the surface potential of the developer carrier and the surface potential of the developer supply member (the surface potential of the developer carrier ( V) —surface potential of developer supply member (V)).

  The surface potential of the developer supply member is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably −400 V to −50 V, more preferably −350 V to −100 V.

  The relationship between the developer carrier surface potential (Pb) during the non-printing operation and the developer carrier surface potential (Pc) during the printing operation is expressed as follows: the developer carrier surface potential (Pb) during the non-printing operation. ) Is larger than the developer carrier surface potential (Pc) at the time of the printing operation on the charged polarity side opposite to the charged polarity of the toner, there is no particular limitation, and it can be appropriately selected according to the purpose. The potential difference (Pb (V) −Pc (V)) is preferably 50 V or more, and more preferably 70 V or more. When the potential difference (Pb (V) −Pc (V)) is 50 V or more, the deteriorated toner is more selectively transferred from the process cartridge or toner cartridge to the supply roller during the non-printing operation. It is preferable in that it is discharged.

  The surface potential of the latent electrostatic image bearing member during the non-printing operation is not particularly limited and may be appropriately selected depending on the intended purpose. However, 150 V or more is on the charged polarity side opposite to the charged polarity of the toner. preferable.

  For example, in an embodiment of the image forming apparatus refresh method according to the present invention, the developing roller surface potential is increased more than during the printing operation so that undeteriorated (−) polarity toner is not discharged as much as possible in the refresh step. By enlarging to the side, the toner of (+) polarity and the toner of low (−) polarity are forcibly developed (discharged) from the ink supply cartridge to the supply roller and further to the development roller.

  Here, in order to increase the developing roller surface potential to the plus side during the non-printing operation, more positively than during the printing operation, the bias voltage application means sets the surface potential value of the developing roller during the printing operation. The surface potential value may be increased or decreased from the surface potential value, and the surface potential value of the supply roller may be increased or decreased from the surface potential value during the printing operation. Further, during the non-printing operation, the bias voltage application means changes both the surface potential value of the developing roller and the surface potential value of the supply roller to be larger or smaller than those during the printing operation. May be.

The image forming apparatus refreshing method and the image forming apparatus are suitable when using a toner having an increased aggregation degree, and more preferable when using a toner having an aggregation degree of 50% or more.
The cause of the increase in the degree of aggregation includes, for example, the use of silica particles treated with a lubricant such as silicone oil as an external additive for the toner.
The aggregation degree of the toner can be measured based on a manual of the powder tester using, for example, a powder tester (PT-X, manufactured by Hosokawa Micron Corporation).

Next, the basic configuration of the image forming apparatus (printer) according to the embodiment of the present invention will be further described with reference to FIG.
FIG. 1 is a schematic diagram illustrating a tandem type image forming apparatus.
Around the photosensitive drum 01, which is an electrostatic latent image carrier, is charged by a charging device 02 for charging the surface of the photosensitive drum 01 and a laser beam 03 for forming an electrostatic latent image on a uniformly charged surface. A developing device 05 for forming a toner image by applying a charged toner to the electrostatic latent image on the surface of the photosensitive drum 01, and transferring the toner image on the formed photosensitive drum 01 to a transfer target. A transfer device 07 and a cleaning device 012 for removing residual toner on the photosensitive drum 01 are sequentially arranged.

In addition, a toner replenishing container 04 that contains replaceable toner, is connected to the developing device 05, and supplies the toner into the developing device 05 is disposed above the developing device 05. Here, the toner supply container 04 has a configuration in which the toner is directly conveyed into the developing device 05. However, a supply path is provided in the main body of the image forming apparatus to supply toner to the developing container. It doesn't matter. In the tandem type electrophotographic apparatus, monochromatic images such as black, magenta, cyan, and yellow are mainly formed on the surface of the photosensitive drum 01. In such a configuration, when image formation is performed by a negative positive method (lowering the exposed portion potential and attaching toner), the photosensitive member whose surface is uniformly negatively charged by a charging roller (not shown) of the charging device 02. An electrostatic latent image is formed on the surface of the body drum 01 by exposure with the laser beam 03. Thereafter, the developing device 05 attaches toner to the surface of the photosensitive drum 01 to visualize the image. The toner image is transferred from the surface of the photosensitive drum 01 by the transfer device 07 including the intermediate transfer belt 013 and the like.
The residual toner component that has not been transferred from the photosensitive drum 01 to the intermediate transfer belt 013 is removed from the surface of the photosensitive drum 01 by the cleaning blade 011 of the cleaning device 012. The toner image transferred to the surface of the intermediate transfer belt 013 is transferred to a recording sheet conveyed from a paper feed tray (not shown) by applying a bias to the secondary transfer roller 08 at the secondary transfer portion. The residual toner component or the external additive component after the transfer is removed by a cleaning member (not shown). The toner image transferred to the recording paper is welded onto the recording paper by the fixing device 09 and discharged from a paper discharge port (not shown). In the figure, a sensor 015 is a sensor used to adjust the image density and alignment by measuring the amount of toner deposited on the intermediate transfer belt 013 and the position of each color, and combines regular reflection and diffuse reflection. It is. In the drawing, a cleaning unit 016 is a cleaning unit that cleans toner remaining on the surface of the intermediate transfer belt 013, and the cleaning blade 014 is brought into contact with the moving direction of the intermediate transfer belt 013 so as to be a counter. In addition, a metal cleaning facing roller 017 is provided so as to face each other. The toner removed by the cleaning blade 014 is conveyed by the coil 018 and stored in a waste toner storage unit (not shown).
By independently provided bias voltage applying means (not shown) for applying a bias voltage, the surface potential of the photosensitive drum 01, the surface potential of the supply roller in the developing device 05, and the surface of the developing roller in the developing device 05 The potential is controlled. Here, the bias voltage applying means is provided independently, but the photosensitive drum 01, the developing roller, and the supply roller may have a built-in function or an internal function.

  The image forming apparatus refreshing method of the present invention preferentially uses unnecessary toner consumption control other than printing for the toner to which a lubricating component is added or the toner having a high degree of deterioration and easily causing background contamination. In the toner replenishment method, the charging characteristics when the new and old toners are mixed can be kept stable, and the deterioration of the print image quality due to background dirt, toner dropping, etc. can be avoided.

(Process cartridge)
The process cartridge of the present invention includes an electrostatic latent image carrier, a developer carrier, a developer supply member, and a bias voltage application unit, and further includes other units as necessary. Become. The developer carrying member and the developer supply member constitute a developing unit.
In the process car cartridge according to the present invention, the electrostatic latent image carrier, the developer carrier, the developer supply member, and the bias voltage application unit are respectively electrostatic in the image forming apparatus according to the invention. This is the same as the latent image carrier, developer carrier, developer supply member, and bias voltage applying means.
The process car cartridge of the present invention can be installed in the main body of the image forming apparatus of the present invention.
There is no restriction | limiting in particular as said other means, According to the objective, it can select suitably, For example, the other means in the image forming apparatus of the above-mentioned this invention etc. are mentioned.

  For example, as shown in FIG. 2, the process cartridge includes an electrophotographic photosensitive member 101 (electrostatic latent image carrier), and in addition, a charging unit 102, a developing unit 104, a transfer unit 106, a cleaning unit 107, This is an apparatus (part) that includes at least one static elimination unit (not shown) and is detachable from the image forming apparatus main body. Referring to the image forming process using the process cartridge of FIG. 2, the electrophotographic photosensitive member 101 is charged in the direction of the arrow while being charged by the charging unit 102 and exposed by the exposure unit 103. A latent image is formed, and the electrostatic latent image is developed with toner by the developing unit 104, and the toner development is transferred to the recording medium 105 by the transfer unit 106 and printed out. Next, the surface of the photoconductor after the image transfer is cleaned by the cleaning unit 107 and further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, the form of this invention is not limited to this. Hereinafter, “part” means “part by mass”.

<Manufacture of polyester 1>
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 235 parts of bisphenol A ethylene oxide 2-mole adduct, 525 parts of bisphenol A propylene oxide 3-mole adduct, 205 parts terephthalic acid, 47 parts adipic acid, and Add 2 parts of dibutyltin oxide, react for 8 hours at 230 ° C. under normal pressure, and further react for 5 hours under reduced pressure of 10 mmHg to 15 mmHg, then put 46 parts of trimellitic anhydride into the reaction vessel at 180 ° C. under normal pressure. By reacting for 2 hours, [Polyester 1] was obtained. [Polyester 1] had a number average molecular weight of 2,600, a weight average molecular weight of 6,900, a glass transition temperature (Tg) of 44 ° C., and an acid value of 26.
The number average molecular weight and the weight average molecular weight are measured by gel permeation chromatography (GPC) (measuring device: GPC-150C (manufactured by Waters), column: KF801-807 (manufactured by Showa Denko KK)), and Tg is It was measured with a differential scanning calorimeter (TG-DSC system, TAS-100, manufactured by Rigaku Corporation). The acid value was measured by a method based on JIS K0070.

<Production of Prepolymer 1>
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2 mol adduct, 81 parts of bisphenol A propylene oxide 2 mol adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 And 2 parts of dibutyltin oxide were added, reacted at 230 ° C. under normal pressure for 8 hours, and further reacted under reduced pressure of 10 mmHg to 15 mmHg for 5 hours to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, Tg of 55 ° C., an acid value of 0.5, and a hydroxyl value of 49.
The number average molecular weight and the weight average molecular weight are measured by gel permeation chromatography (GPC) (measuring device: GPC-150C (manufactured by Waters), column: KF801-807 (manufactured by Showa Denko KK)), and Tg is It was measured with a differential scanning calorimeter (TG-DSC system, TAS-100, manufactured by Rigaku Corporation). Moreover, the acid value and the hydroxyl value were measured by the method based on JIS K0070.

  Next, 411 parts of [Intermediate Polyester 1], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Prepolymer 1] was obtained. The ratio of free isocyanate in [Prepolymer 1] was 1.53% by mass.

<Manufacture of master batch 1>
40 parts of carbon black (REGAL (registered trademark) 400R, manufactured by Cabot), binder resin (polyester resin, RS-801, manufactured by Sanyo Chemical Industries, Ltd., acid value 10, number average molecular weight 20,000, Tg 64 ° C.) 60 And 30 parts of water were mixed with a Henschel mixer (manufactured by Nippon Coke Industries Co., Ltd.) to obtain a mixture in which water was soaked into the pigment aggregate. This was kneaded for 45 minutes with two rolls set at a roll surface temperature of 130 ° C. and pulverized to a size of 1 mm with a pulverizer to obtain [Masterbatch 1].

<Oil phase preparation process>
In a container equipped with a stirring rod and a thermometer, 545 parts of [Polyester 1], 181 parts of paraffin wax, and 1,450 parts of ethyl acetate were charged, heated to 80 ° C. with stirring, and maintained at 80 ° C. for 5 hours. Thereafter, it was cooled to 30 ° C. in 1 hour. Next, 500 parts of [Masterbatch 1], 100 parts of charge control agent, and 100 parts of ethyl acetate were charged in a container and mixed for 1 hour to obtain [Raw material solution 1].

  [Raw material solution 1] 1,500 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by IMEX Co., Ltd.), a liquid feed speed of 1 kg / hour, a disk peripheral speed of 6 m / second, and 0.5 mm zirconia beads are obtained. Carbon black and WAX were dispersed under the conditions of 80% by volume filling and 3 passes. Next, 425 parts of [Polyester 1] was added, and one pass was performed with a bead mill under the above conditions, and the solid content concentration of [Pigment / WAX dispersion (oil phase) 1] ([Pigment / WAX dispersion (oil phase) 1) was 50% by mass).

<Water phase preparation process>
970 parts of ion-exchanged water, 40 parts of a 25% by weight aqueous dispersion of organic resin fine particles for dispersion stabilization (styrene copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate), dodecyl 140 parts and 90 parts of 48.5% aqueous solution of diphenyl ether sodium disulfonate (Eleminol MON-7, Sanyo Chemical Industries, Ltd.) were mixed and stirred to obtain [Aqueous Phase 1] as a milky white liquid.

<Emulsification process>
[Pigment / WAX Dispersion (Oil Phase) 1] 975 parts and 2.6 parts of isophoronediamine as amines were mixed for 1 minute at 5,000 rpm with a TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.). After adding 88 parts of prepolymer 1] and mixing with TK homomixer at 5,000 rpm for 1 minute, add 1,200 parts of [aqueous phase 1], and using TK homomixer, the rotational speed is 8,000 rpm to 13,000 rpm. While adjusting, the mixture was mixed for 20 minutes to obtain [Emulsion slurry 1].

<Demelting process>
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and the solvent was removed at 30 ° C. for 8 hours to obtain [Dispersion slurry 1].

<Washing and drying process>
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
(1): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered. The filtrate at this time was milky white.
(2): 900 parts of ion-exchanged water was added to the filter cake of (1), ultrasonic vibration was applied, and the mixture was mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure. This operation was repeated so that the electric conductivity of the reslurry liquid was 10 μC / cm or less.
(3): 10% hydrochloric acid was added so that the reslurry solution of (2) had a pH of 4, and the mixture was stirred as it was with a three-one motor for 30 minutes and then filtered.
(4): 100 parts of ion-exchanged water was added to the filter cake of (3), mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered. This operation was repeated so that the reslurry liquid had an electric conductivity of 10 μC / cm or less to obtain [Filter Cake 1].
[Filtration cake 1] was dried at 42 ° C. for 48 hours in a circulating drier and sieved with a mesh having an opening of 75 μm to obtain [Toner base 1]. [Toner Base 1] has an average circularity of 0.974, a volume average particle size (Dv) of 6.3 μm, a number average particle size (Dp) of 5.3 μm, and a particle size distribution of Dv / Dp of 1.19. It was a thing.

<Manufacture of toner 1>
[Toner base 1] 100 parts of commercially available silica fine powder, 1 part of H20TM (manufactured by Clariant Japan, average primary particle size 12 nm, no silicone oil treatment) and RY50 (manufactured by Nippon Aerosil Co., Ltd., average primary particles) Toner 1 was obtained by mixing 2 parts with a Henschel mixer and removing coarse particles and aggregates by passing through a sieve having an opening of 60 μm.
The aggregation degree of the toner 1 was measured by the following procedure and found to be 54.4%.

<Manufacture of toner 2>
[Toner base 1] 100 parts of commercially available silica fine powder, 1 part of H20TM (manufactured by Clariant Japan, average primary particle size 12 nm, no silicone oil treatment) and RX50 (manufactured by Nippon Aerosil Co., Ltd., average primary particles) Toner 2 was obtained by mixing 2 parts with a Henschel mixer and removing coarse particles and aggregates by passing through a sieve having an opening of 60 μm.
The aggregation degree of the toner 2 was measured by the following procedure and found to be 40.3%.

<Measurement of toner aggregation degree>
The degree of toner aggregation was measured as follows.
A powder tester (PT-X, manufactured by Hosokawa Micron Corporation) was used, and accessory parts were set on the vibration table by the following procedure.
(I) Vibro chute, (b) Packing, (c) Space ring, (d) Fluey (3 types) Top>Medium> Bottom, (e) Oseva, then fixed with a knob nut and actuated the shaking table .
The measurement conditions were as follows.
Sieve opening: (top) 75 μm, (middle) 45 μm, (bottom) 20 μm, amplitude scale: 1 mm, sampled amount: 2 g, vibration time: 10 seconds After measurement based on the above procedure, the degree of aggregation was calculated from the following calculation. Asked.
(A) Mass% of powder remaining on upper sieve × 1
(B) Mass% of powder remaining on middle stage sieve × 0.6
(C) Mass% of powder remaining on the lower sieve × 0.2
The total of the three calculated values was defined as the degree of aggregation [%].

Example 1
Toner 1 was used.
Using a modified machine of IPSiO SP C310 (manufactured by Ricoh Co., Ltd.), 2,000 sheets of a predetermined print pattern with a printing rate of 0.5% were continuously copied in an environment of 27 ° C. and 80% RH. For each sheet, as a non-printing operation, a bias voltage was applied to the photosensitive member and the supply roller so as to achieve a printing rate of 2.0% (hereinafter referred to as “refresh operation”).
Here, the printing rate means 100% (%) of the printing area when the area in the work area on the paper surface is 100%.
At the time of printing operation, the supply roller, the developing roller, and the photoreceptor incorporated in IPSiO SP C310 (manufactured by Ricoh Co., Ltd.) are each provided with the function of the bias voltage applying unit, and the applied potential on each surface is set. , −250V, −150V, and −450V.
On the other hand, at the time of non-printing operation in the refresh process, the applied potentials on the surfaces of the supply roller, the developing roller, and the photosensitive member are set to −320V, −150V, and −550V by the bias voltage applying unit having the function built-in. It was.

(Example 2)
Example 1 except that the applied potentials of the supply roller, the developing roller, and the surface of the photosensitive member during the printing operation and the non-printing operation are changed to those shown in Table 1-1 by the bias voltage application unit, respectively. The same operation was performed.

(Example 3)
The same operation as in Example 1 was performed except that toner 2 was used instead of toner 1.

(Comparative Example 1)
Example 1 except that the applied potentials of the supply roller, the developing roller, and the surface of the photosensitive member during the printing operation and the non-printing operation are changed to those shown in Table 1-1 by the bias voltage application unit, respectively. The same operation was performed.

(Comparative Example 2)
The same applies as in Example 1 except that the applied potentials of the supply roller, the developing roller, and the surface of the photosensitive member during printing operation and non-printing operation are changed to those shown in Table 1-1 by the bias voltage applying unit. Was performed.

Table 1-1 shows the following.
-Developing roller surface potential during printing operation and non-printing operation: (Developing roller surface potential (V))-(Supply roller surface potential (V)) value-Photoconductor during printing operation and non-printing operation Surface potential: value of (photosensitive member surface potential (V)) − (developing roller surface potential (V)) Table 1-2 shows the following.
-(Developing roller surface potential (V) during non-printing operation)-(Developing roller surface potential (V) during printing operation)-(Photoconductor surface potential (V) during non-printing operation)-(Photoconductor during printing operation) Value of surface potential (V)

  Each of the following evaluations was performed for Examples 1 to 3 and Comparative Examples 1 and 2. The results are shown in Table 2.

<Photoreceptor wear evaluation>
Before and after the 5,000 m running test, measurement was performed using a film thickness measuring instrument Fischer scope MMS (manufactured by Fischer Instruments Co., Ltd.), and the photoreceptor wear amount was evaluated from the results.
Judgment criteria are as follows. The judgment “◎” or “○” is at a level where there is no problem in the actual specification.
◎: Wear amount less than 2.5 μm ○: Wear amount 2.5 μm or more, less than 5 μm ×: Wear amount 5 μm or more

<Skin dirt evaluation>
After the 2,000-sheet passing test, the toner remaining on the photoconductor is peeled off with a booker tape, and the L * value of the tape that has been affixed to a white paper is measured with a spectrophotometer. Evaluated. Here, the L * value is a parameter corresponding to lightness (color brightness). The judgments “◎” and “○” are at a level where there is no problem in the actual specification.
Judgment criteria are as follows.
A: L * value> 95
○: 90 <L * value ≦ 95
×: L * value ≦ 90

<Evaluation of toner drop (color loss)>
The number of toner drop points of the image formed on the last paper after the 2,000-sheet passing test was visually counted and judged.
Judgment criteria are as follows. Judgment ◎ and ○ are levels that are not problematic in actual specifications.
○: Good (number of toner drop points is less than 3)
×: Defect (number of toner dropping points is 3 or more)

<Comprehensive evaluation>
Only when the photoreceptor wear amount, background stain, and toner drop were judged to be “汚 れ” or “◯”, the overall evaluation was judged as “◯”. When any one item was “x”, the comprehensive evaluation was “x”.

According to the image forming apparatus refreshing method and the image forming apparatus of the present invention, in order to reduce the surface friction of the photoreceptor, when a toner having a high degree of aggregation is used, to which an external component added with a lubricant component is added. Even in such a case, the deterioration of the print image quality due to toner dropping or background stains can be avoided.
In Comparative Example 1, forcible deterioration toner does not move from the developing roller to the photoconductor in the refresh operation. Therefore, in Comparative Example 2, forcing from the process cartridge to the developing roller via the supply roller in the refresh operation. Since the toner does not move as expected, toner drop (color loss) and background stains were observed.

The aspect of the present invention is as follows.
<1> An electrostatic latent image carrier that carries an electrostatic latent image; a developer carrier that contains toner and carries a developer that develops the electrostatic latent image; and the toner that is applied to the developer carrier. In the image forming apparatus having a developer supply member to be supplied, an image forming apparatus refresh method that consumes deteriorated toner contained in the toner during a non-printing operation,
The potential difference between the surface potential of the electrostatic latent image carrier and the surface potential of the developer carrier during non-printing operation (surface potential of the electrostatic latent image carrier (V) −surface potential of the developer carrier ( V)) the electrostatic latent image carrier surface potential is larger than the electrostatic latent image carrier surface potential during the printing operation, and
In a non-printing operation, the potential difference between the surface potential of the developer carrier and the surface potential of the developer supply member (surface potential of developer carrier (V) −surface potential of developer supply member (V)) A certain developer carrier surface potential is larger than the developer carrier surface potential during the printing operation.
An image forming apparatus refreshing method comprising applying a bias voltage to at least one of the electrostatic latent image carrier, the developer carrier, and the developer supply member.
<2> The difference between the surface potential of the electrostatic latent image carrier during the non-printing operation and the surface potential of the electrostatic latent image carrier during the printing operation (the electrostatic latent during the non-printing operation). <1> The image carrier surface potential (V) —the electrostatic latent image carrier surface potential (V) during the printing operation is set to have the same charge polarity as the toner charge polarity and 100 V or more. The image forming apparatus refresh method described in 1. above.
<3> The bias potential is applied so that the surface potential of the electrostatic latent image carrier in the non-printing operation is the same as the charge polarity of the toner and is 400 V or more. <1> to <2> The image forming apparatus refresh method according to any one of the above.
<4> The difference between the developer carrying member surface potential during the non-printing operation and the developer carrying member surface potential during the printing operation (the developer carrying member surface potential during the non-printing operation ( V) —Developer surface potential (V)) during the printing operation is set to any one of the above items <1> to <3>, which is performed so that the charged polarity opposite to the charged polarity of the toner is 50 V or more. The image forming apparatus refresh method described.
<5> The bias potential is applied so that the surface potential of the developer carrying member during the non-printing operation has a charge polarity opposite to the charge polarity of the toner and is 150 V or more. <1> to <4> The image forming apparatus refresh method according to any one of the above.
<6> The image forming apparatus refresh method according to any one of <1> to <5>, wherein the aggregation degree of the toner is 50% or more.
<7> The image forming apparatus refresh method according to any one of <1> to <6>, wherein the toner is externally added with silica particles surface-treated with silicone oil.
<8> An electrostatic latent image carrier that carries an electrostatic latent image;
A developer carrying body containing a toner and carrying a developer for developing the electrostatic latent image;
A developer supply member for supplying toner to the developer carrier;
The potential difference between the surface potential of the electrostatic latent image carrier and the surface potential of the developer carrier during non-printing operation (surface potential of the electrostatic latent image carrier (V) −surface potential of the developer carrier ( V)) the electrostatic latent image carrier surface potential is larger than the electrostatic latent image carrier surface potential during the printing operation, and
In a non-printing operation, the potential difference between the surface potential of the developer carrier and the surface potential of the developer supply member (surface potential of developer carrier (V) −surface potential of developer supply member (V)) A certain developer carrier surface potential is larger than the developer carrier surface potential during the printing operation.
Bias voltage applying means for applying a bias voltage to at least one of the electrostatic latent image carrier, the developer carrier, and the developer supply member;
An image forming apparatus comprising:
<9> An electrostatic latent image carrier that carries an electrostatic latent image;
A developer carrying body containing a toner and carrying a developer for developing the electrostatic latent image;
A developer supply member for supplying toner to the developer carrier;
The potential difference between the surface potential of the electrostatic latent image carrier and the surface potential of the developer carrier during non-printing operation (surface potential of the electrostatic latent image carrier (V) −surface potential of the developer carrier ( V)) the electrostatic latent image carrier surface potential is larger than the electrostatic latent image carrier surface potential during the printing operation, and
In a non-printing operation, the potential difference between the surface potential of the developer carrier and the surface potential of the developer supply member (surface potential of developer carrier (V) −surface potential of developer supply member (V)) A certain developer carrier surface potential is larger than the developer carrier surface potential during the printing operation.
Bias voltage applying means for applying a bias voltage to at least one of the electrostatic latent image carrier, the developer carrier, and the developer supply member;
It is a process cartridge characterized by having.

01 Photosensitive drum 02 Charging device 03 Laser light 04 Toner supply container 05 Developing device 07 Transfer device 08 Secondary transfer roller 09 Fixing device 011 Cleaning blade 012 Cleaning device 013 Intermediate transfer belt 014 Cleaning blade 015 Sensor 016 Cleaning unit 017 Cleaning counter roller 018 Coil 101 Electrophotographic photosensitive member 102 Charging means 104 Developing means 106 Transfer means

JP 2009-098700 A Japanese Patent No. 3029648 JP 2001-074438 A JP 2009-145488 A

Claims (9)

An electrostatic latent image carrier that carries an electrostatic latent image, a developer carrier that contains toner and carries a developer that develops the electrostatic latent image, and a development that supplies the toner to the developer carrier In the image forming apparatus having the agent supply member, the image forming apparatus refresh method for consuming the deteriorated toner contained in the toner during the non-printing operation,
The potential difference between the surface potential of the electrostatic latent image carrier and the surface potential of the developer carrier during non-printing operation (surface potential of the electrostatic latent image carrier (V) −surface potential of the developer carrier ( V)) the electrostatic latent image carrier surface potential is larger than the electrostatic latent image carrier surface potential during the printing operation, and
In a non-printing operation, the potential difference between the surface potential of the developer carrier and the surface potential of the developer supply member (surface potential of developer carrier (V) −surface potential of developer supply member (V)) A certain developer carrier surface potential is larger than the developer carrier surface potential during the printing operation.
An image forming apparatus refreshing method, comprising: applying a bias voltage to at least one of the electrostatic latent image carrier, the developer carrier, and the developer supply member.   The difference between the surface potential of the electrostatic latent image carrier during the non-printing operation and the surface potential of the electrostatic latent image carrier during the printing operation (the electrostatic latent image carrier during the non-printing operation). 2. The image according to claim 1, wherein the surface potential (V) —the surface potential (V) of the electrostatic latent image carrier at the time of the printing operation is set to be equal to or more than 100 V with the same charge polarity as that of the toner. Forming device refresh method.   3. The bias potential is applied so that the surface potential of the electrostatic latent image carrier during non-printing operation is the same as the charge polarity of the toner and is 400 V or more. Image forming apparatus refresh method.   The difference between the developer carrying member surface potential during the non-printing operation and the developer carrying member surface potential during the printing operation (the developer carrying member surface potential (V) − during the non-printing operation) 4. The image forming apparatus refresh according to claim 1, wherein the developer carrying member surface potential (V)) during the printing operation is performed such that the charged polarity is opposite to the charged polarity of the toner and is 50 V or more. Method.   The image according to any one of claims 1 to 4, wherein the bias potential is applied such that a developer carrier surface potential in a non-printing operation has a charge polarity opposite to that of the toner and is 150 V or more. Forming device refresh method.   The image forming apparatus refreshing method according to claim 1, wherein the toner has an aggregation degree of 50% or more.   The image forming apparatus refreshing method according to claim 1, wherein the toner is externally added with silica particles surface-treated with silicone oil. An electrostatic latent image carrier carrying an electrostatic latent image;
A developer carrying body containing a toner and carrying a developer for developing the electrostatic latent image;
A developer supply member for supplying toner to the developer carrier;
The potential difference between the surface potential of the electrostatic latent image carrier and the surface potential of the developer carrier during non-printing operation (surface potential of the electrostatic latent image carrier (V) −surface potential of the developer carrier ( V)) the electrostatic latent image carrier surface potential is larger than the electrostatic latent image carrier surface potential during the printing operation, and
In a non-printing operation, the potential difference between the surface potential of the developer carrier and the surface potential of the developer supply member (surface potential of developer carrier (V) −surface potential of developer supply member (V)) A certain developer carrier surface potential is larger than the developer carrier surface potential during the printing operation.
Bias voltage applying means for applying a bias voltage to at least one of the electrostatic latent image carrier, the developer carrier, and the developer supply member;
An image forming apparatus comprising: An electrostatic latent image carrier carrying an electrostatic latent image;
A developer carrying body containing a toner and carrying a developer for developing the electrostatic latent image;
A developer supply member for supplying toner to the developer carrier;
The potential difference between the surface potential of the electrostatic latent image carrier and the surface potential of the developer carrier during non-printing operation (surface potential of the electrostatic latent image carrier (V) −surface potential of the developer carrier ( V)) the electrostatic latent image carrier surface potential is larger than the electrostatic latent image carrier surface potential during the printing operation, and
In a non-printing operation, the potential difference between the surface potential of the developer carrier and the surface potential of the developer supply member (surface potential of developer carrier (V) −surface potential of developer supply member (V)) A certain developer carrier surface potential is larger than the developer carrier surface potential during the printing operation.
Bias voltage applying means for applying a bias voltage to at least one of the electrostatic latent image carrier, the developer carrier, and the developer supply member;
A process cartridge comprising: