KR100495638B1 - A developing apparatus - Google Patents

Abstract

Toner supply to the developing roller is smoothly performed for a long time, so that high quality can be obtained.

For the latent electrostatic image formed on the outer circumferential surface of the photosensitive drum 21, the developing apparatus 30 supplies by developing the non-magnetic-based toner 32 from the shape roller 33. The toner 32 is supplied from the supply roller 34 to the developing roller 33 in the toner container 31 in a positively charged state. A positive DC bias voltage is applied to the developing roller 33 and the supply roller 34 from the DC power sources 35 and 36. The feed roller 34 has a plurality of conductive yarns 40 planted on the outer circumferential surface of the core material 41 and contacts the surface of the developing roller 33 at the tip of the yarn material 40. .

Description

Developing apparatus {A DEVELOPING APPARATUS}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing apparatus for supplying and developing a developer to an electrostatic latent image for forming an image by an electrophotographic method, and particularly to a part related to a supply roller for supplying a developer to a developer carrying member.

Background Art Conventionally, cameras, printers, printers, fax milling apparatuses, and the like, which form images in an electrophotographic system, develop and develop an electrostatic latent image formed on an image carrier using a dry powder developer called a toner. I'm making it.

14 shows the configuration of a typical image forming apparatus. The photoconductive insulator layer is formed on the surface of the photosensitive drum 1 which is an image carrier, and usually shows electrical insulation, and the part to which light is irradiated shows electroconductivity. Since the photosensitive drum 1 rotates in the rotation direction 1a and makes the surface into a charged state, the charger 2 is provided toward the outer peripheral surface of the photosensitive drum 1. The developing apparatus 3 is disposed downstream of the charger 2 with respect to the rotation direction 1a. On the downstream side of the developing apparatus 3, the recording paper 4 is in contact with the outer circumferential surface of the photosensitive drum 1. The transfer machine 5 is disposed on the opposite side of the photosensitive drum 1 with the recording sheet 4 interposed therebetween. The cleaner 6 is disposed on the distillation side of the charger 2 on the downstream side of the contact portion with the recording sheet 4 with respect to the rotation direction 1a. The recording sheet 4 is conveyed to the fixing device 7 after contacting with the photosensitive drum 1. The fixing device 7 is provided with a heating roller 8 and a pressure roller 9, presses the recording paper 4, and heats it.

In the inversion phenomenon of the electrophotographic method, first, the outer peripheral surface of the photosensitive drum 1 as the image bearing member is similarly charged by the charger 2. When light irradiation 10 is applied to the outer circumferential surface of the charged photosensitive drum 1, the portion that receives the light irradiation 10 becomes conductive and loses electric charge, and the portion that does not receive the light irradiation 10 undergoes a charged state. As a result, an electrostatic latent image is formed. The developing apparatus supplies charged toner. When the charging polarity of the toner is made equal to the charging polarity of the photosensitive drum 1, the toner is selectively attached to the portion where the charge is lost by the light irradiation 10, and development by the toner is performed. The transfer machine 5 performs corona discharge with a polarity opposite to charging of the toner to generate a suction force for transferring the toner on the outer peripheral surface of the photosensitive drum 1 onto the recording paper 4. The toner contains a binder resin, which is melted by heat and pressure of the fixing unit 7 to fix the toner transferred onto the recording paper 4.

The developing apparatus 3 stores the toner 12 in the toner container 11. Toners that are dry developers used for electrophotographic image formation include nonmagnetic-based, magnetic-based, bicomponent, and the like. In the non-magnetic toner 12, a developing roller 13 as a developer carrying member is provided at the outlet of the toner container 11, and the toner 12 is attached to the outer circumferential surface of the developing roller 13. The outer peripheral surface of the drum 1 is in direct contact. In order to efficiently attach the toner 12 in the toner container 11 on the outer circumferential surface of the developing roller 13, a supply roller 14 in the toner container 11 is provided. The feed roller 14 agitates the toner in the toner container 11 and moves it toward the developing roller 13 while contacting the developing roller 13. The toner 12 is charged with negative polarity, for example, by mutual friction during stirring. In order to smoothly move the toner 12, the developing roller 13 and the supply roller 14 are provided with conductivity in a state where the electrical resistance is high, as compared with a metal conductor, so that the DC power supply 15 , 16) are respectively given a negative DC bias voltage. The absolute value of the DC bias voltage is set so that the side of the supply roller 14 is coincident with or higher than the developing roller 13. The polarity of the DC bias voltage of the developing roller 13 is the same as the charging polarity of the photosensitive drum 1.

In the developing apparatus 3 using the nonmagnetic-based toner 12 as shown in FIG. 14, the toner 12 in the toner container 11 is transferred to the developing roller 13 through the supply roller 14. Supply. If the supply of the toner 12 to the developing roller 13 is not performed properly, it causes a defective image to be developed. The conventional feed roller 14 has a surface layer, such as rubber | gum, for example, but it is difficult to maintain the contact state with the developing roller 13 which is stable from an initial stage in the long term. For this reason, there is a demand for a developing apparatus capable of stably forming high quality images in the long term.

An object of the present invention is to provide a developing apparatus capable of smoothly supplying toner to an image carrier and maintaining high quality in the long term from the beginning.

The present invention relates to a developing apparatus comprising a developer carrying member for developing an electrostatic latent image in a non-magnetic developer for forming an image by an electrophotographic method, and a supply roller for feeding the developer to the developer carrying member. In

Feed rollers,

Roll-shaped core,

It is planted on the outer circumferential surface of the core material, and is a developing device characterized in that the tip includes one or more yarns in contact with the developer carrier.

According to the present invention, in order to form an electrophotographic image in which a latent electrostatic image is developed in a non-magnetic developer, an image defect caused by supply of a developer onto a developer carrier can be prevented, and from the beginning to a long term. A supply roller capable of maintaining high image quality can be realized. On the surface of the developer carrying member having a predetermined surface roughness or a predetermined hardness, the supply roller supplies the developer. The feed roller is formed by planting a plurality of yarns on the outer circumferential surface of the roll-shaped core material, and since the surface of the yarns contacts the surface of the developer carrier, the electric field between the developer carrier and the feed roller, and the developer carrier If conditions such as a high speed ratio between the retardation member and the supply roller, nip width (erosion amount), and the like are appropriate, the developer is supplied from the supply roller to the developing carrier, and the supplied developer is supplied by a predetermined developer regulating member. The developer, which is regulated by a predetermined developer layer thickness, and whose layer thickness is regulated, can be used for the development of the electrostatic latent image bearing member at a predetermined electric field in the developing region.

In addition, in the present invention, the yarn is planted on the outer circumferential surface of the core material by the electrostatic weaving method,

The length of this yarn is characterized in that the range of 0.5mm or more and 3mm or less.

According to the present invention, the yarn is planted on the outer circumferential surface of the core by the electrostatic weaving method, and the length of the yarn is in the range of 0.5 mm or more and 3 mm or less. When the density decreases and the length of the yarn is shortened, the density of the yarn to be planted and installed by the electrostatic seedling method increases, so that the density can be adjusted to the length of the yarn.

In addition, the yarn in the present invention is characterized in that the single yarn decitex is more than 1 decitex, the range of less than 10 decitex.

According to the present invention, the range of single yarn decitex of the yarn is 1 decitex or more and 10 decitex or less, so that an appropriate contact state can be obtained.

In addition, in the present invention, the yarn is characterized in that it has conductivity and has electrical conductivity with the core material.

According to the present invention, the yarn is conductive and electrically conductive also with the core, so that electric charge can be applied to the developer in contact with the yarn.

Further, in the present invention, the yarn is characterized in that the single thread resistance value is 10 ⁵ Ω / cm or more, 10 ¹² Ω / cm or less.

According to the present invention, since the single yarn resistance value of the yarn is 10 ⁵ Ω / cm or more and 10 ¹² Ω / cm or less, appropriate charge can be given to the developer in contact with the yarn.

In the present invention, the yarn is characterized in that the yarn produced by the composite spinning method.

According to the present invention, since the yarn is manufactured by the composite spinning method, it is possible to appropriately impart conductivity or the like.

In addition, the present invention further includes a power source for applying a voltage to the developer carrier and the supply roller, respectively,

The difference between the voltage applied to the developer carrying member and the voltage applied to the supply roller is in the range of 0V to 350V.

According to the present invention, since the voltage is applied from the power supply to the developer carrying member and the supply roller, the difference in the applied voltage is kept in a constant range, and the supply of the developer can be continued stably.

In the present invention, in the developer carrying member, the portion in contact with the supply roller is moved to perform the latent electrostatic image development,

And a rotation mechanism for rotating the feed roller so that the speed ratio of the portion of the tip of the yarn is in the range of 0.5 to 2.0 times with respect to the speed at which the developer carrying member moves.

According to the present invention, in the contact portion between the developer carrying member and the feed roller, the speed ratio of the tip portion of the yarn material of the feed roller is 0.5 times or more and 2.0 times or less with respect to the speed at which the developer carrying member moves. Since the feed roller is driven to rotate by the rotating mechanism, the supply state of the developer can be adjusted even by the speed ratio, and the image quality can be improved.

In addition, in the present invention, the feed roller is characterized in that the insertion amount pushed on the surface of the developer carrier of the yarn material is -0.1mm or more and 0.7mm or less with respect to the developer carrier.

According to the present invention, since the sanding material of the developing roller is pushed in the range of -0.1 mm or more and 0.7 mm or less on the surface of the developer carrying member, the developer can be smoothly supplied to the developer carrying member.

1 shows the configuration of a main part of an image forming apparatus 20 by an electrophotographic method including a developing apparatus which is one embodiment of the present invention. The surface of the outer circumferential surface of the photosensitive drum 21, which is on the development bearing member, is similarly charged by the polarizer 22 by the polarizer. After the latent charging image is formed by the light irradiation system 23, the developing device 30 is developed. Formation of an electrostatic latent image is performed by light irradiation by the light irradiation system 23 to the outer peripheral surface surface of the photosensitive drum 21. The light irradiation system 23 modulates light from a light source such as laser light or a light emitting diode (LED), or irradiates light by optically introducing reflected light from the surface of a radiant document.

The developing apparatus 30 stores the dry nonmagnetic-based toner 32 in the toner container 31 and supplies it to the photosensitive drum 21 through the developing roller 33 which is a developer carrying member. The developing roller 33 is conductive, is softer than the outer peripheral surface of the photosensitive drum 21, and is formed of a rubber-based material having elasticity. In the toner container 31, there is also provided a supply roller 34 which stirs the toner 32 to positively charge and supplies it to the developing roller 33. A bipolar DC bias voltage is applied to the developing roller 33 and the supply roller 34 from the DC power sources 35 and 36, respectively. The layer thickness of the toner 32 adhering on the outer circumferential surface of the developing roller 33 is thinly restricted by the blade 37. The blade 37 is made of a hard rubber-based material having conductivity, and a bias voltage is applied by the DC power supply 38. In the supply roller 34 of this embodiment, many yarns 40 are planted and installed in the outer peripheral surface of the core material 41. As shown in FIG.

FIG. 2 shows a schematic configuration of the feed roller 34 shown in FIG. Fig. 2 (a) shows the state seen from the front cross section, and Fig. 2 (b) shows the state seen from the side cross section. The core 41 is supported so as to be conductive in a roller made of metal such as iron and to be rotatable at both ends. On the surface of the core material 41, the hair-growth layer of the yarn 40 formed by the electrostatic hair-flation method is formed. The seedling layer is formed by adhering the proximal ends of the plurality of yarns 40 to the surface of the core material 41 in the adhesive agent 42.

3 shows the principle of forming the hair-growing layer of the yarn 40 by the electrostatic weaving method. For example, when a radial electric field is generated around the core material 41, and the yarn 40 which has been cut to a predetermined length is adsorbed, it can be attached radially around the core material 41 along the electric field. When the adhesive agent 42 is applied to the surface of the core material 41, the adsorbed yarn material 40 can be adhered to the surface of the core material 41, and a seedling layer can be formed easily.

That is, by using the yarn 40 cut to a predetermined length, the yarn 40 is planted by the electrostatic planting method while rotating the core 41 around the axis on the outer circumferential surface of the roller-shaped core 41. do. The yarn 40 can be planted with respect to the core 41 by any material of electrical insulation or electrical conductivity, and the yarn 41 and the core 41 are bonded to the core 41 by using an insulating adhesive or a conductive adhesive. Bond with. As the adhesive, an aqueous acrylic emulsion adhesive, a urethane adhesive, or a polyester hot melt adhesive can be used. In order to have conductivity, conductive materials such as silver paste are mixed in the adhesive.

When using as the supply roller 34 of FIG. 2, it is preferable that the yarn 40 has electroconductivity. When electroconductivity is needed, the yarn 40 which comprises a tufted layer can be used, for example, giving electroconductivity to nylon fiber or acrylic fiber. When using such a feed roller 34, the speed ratio (theta) = 0.5-2.0 of the circumferential speed and the circumferential speed of the developing roller 33 is set. Although electroconductivity is required for the material 40, electroconductivity can also be adjusted by changing a ratio by combining electroconductive yarn and an electrically insulating yarn.

4 and 5 show examples of conductive fibers that can be used as the yarn 40 having conductivity. The name of the manufacturer is abbreviated as the manufacturer's name. In the diagram, "PET" represents a polyethylene terephthalate fiber. "Ny" represents a nylon fiber. "An" represents an acrylic fiber. "R" represents a rayon-based fiber. "Ar" represents an aromatic amine fiber. "G" represents a glass type fiber. "CB" represents carbon black. "M" represents an intermetallic compound. "FY" represents long fiber. "SF" represents short fiber. The denominator of the fiber degree represents the number of filaments.

In addition, composite spinning is also called conjugate spinning, and is a method of spinning aimed at producing two or more kinds of polymers of different physical properties from one hole at the same time to make fibers utilizing their respective properties. In addition, mixing spinning is a method of mixing a specific material in the spinning step, and when producing a conductive fiber, a conductive agent such as carbon black can be mixed. The dispersion type is obtained by dispersing a conductive agent in a material and spinning it.

As the yarn material 40 of this embodiment, "mega III" shown in FIG. 5 can be used suitably. Only one type of functional fiber 24 may be used, or many types may be used. Table 1 below shows an example of physical properties when the trade name "MegaIII-N" is used as the material 40.

TABLE 1

type The nature of the thread Electric resistance value Ω / cm Hydrothermal shrinkage 100 ℃ × 30 minutes% Dry shrinkage 180 ℃ x 20 minutes%  Fiber dtex   Strength of cn / dtex  Elongation% T-1 125.9 1.78 64.9 2.5 × 10 ⁶ 10.9 9.2 T-2 129.8 1.62 58.7 1.4 × 10 ⁶ 6.8 6.1

FIG. 6: shows typically the cross-sectional structure at the time of using the type T-2 shown in Table 1 as the yarn 40. As shown in FIG. A layer of the conductive material 44 made of conductive carbon fine particles is formed around the core fiber 43 made of nylon 6. Such a structure can be formed by a composite spinning method as shown in FIG. In addition, when using the electrostatic tufting method shown in FIG. 2, it is easy to fly that the surface is electroconductive and the inside is an electrically insulating fiber.

Conventionally, although the hair-growing roller is produced using the hair-growing technique, there are few materials which have functionality, such as electroconductivity, and the usage method is limited. For example, in the conductive fiber manufactured by the conventional composite spinning method, the electrical insulation part and the electroconductive part are clearly divided on the surface of a fiber, and it turns into one fiber. In such a structure, an electric field is formed on the surface of the fiber electrostatically, and the adhesion force by the electric field becomes large. Moreover, exposure of the insulator part on the fiber surface is large, and electric charge is hard to escape. In accordance with such an increase in adhesion force and residual charge, clogging is likely to occur, and it is necessary to cope with clogging radiation. Moreover, in order to reduce the electric field of a surface, after apply | coating with an electrically conductive coating material about insulating fiber, it is also used for hair transplantation. However, since the use of this conductive coating material causes peeling due to abrasion, it is not effective in an apparatus requiring long life, and improvement is necessary. In addition, when weaving fibers on the rollers by flying the fibers in an electric field, the electrical properties and the cross-sectional shape of the fibers themselves are also affected, and when the electrical resistance value is too low, it is difficult to escape and there is a problem that the seedling density decreases. have.

In this embodiment, in order to improve these problems, it is a fiber as shown in Table 1 which comprises the part which exposes to the surface by complex spinning as an improvement from the fiber itself by the conductor, and the ratio which an insulation part exposes. This fiber of 50% or less is used. A fiber obtained by uniformly dispersing or mixing carbon black in the fiber may be used so that the resistance value of the fiber becomes a predetermined value. Even in low-resistance fibers, the fiber surface can be treated to stabilize the seedling density. When forming a thin film as a process on a fiber surface, it can carry out the hair transplant after film formation, and can reduce a film | membrane density by post-processing, and can stabilize a hair-growing density.

In addition, if the surface of the feed roller 34 of this embodiment is comprised by the yarn 40, and the yarn 40 is electroconductive, the material of the core material 41 will not only be a metal but also any of conductive resin and paper. It may consist of one. The length of the yarn material 40 is 0.5 mm or more and can be made into the range which is 3 mm or less. As a property of the tufted layer by the yarn 40, when the fiber is long, the tuft level of the unit area becomes slender, and when it is short, it tends to be dense. The reason for this is that, when the electrostatic tufting method as shown in Fig. 3 is adopted, the fibers are blown electrically. The fibers of the yarn 40 adhere perpendicularly to the outer circumferential surface of the core material 41 because they have a tendency of adhesion in the fiber state in which the electric field is the strongest. When the fiber of the yarn 40 is lengthened, the fiber tends to be entangled during movement by the electric field, becomes difficult to adhere vertically, and the density decreases. For example, as a result of the conventional evaluation of the toner supply roller, when the length is about 2 mm, it is found that the toner supplyability starts to decrease due to the decrease in the vertical fiber density. When the length of the fiber becomes 3 mm, the fibers become coarse in the form of entanglement between the fibers, and the tufting layer itself becomes a tuft of a level that seems to have a gap, so that the toner 32 cannot be supplied almost. If the length of the fiber is smaller than 0.5 mm, conversely, the tufted layer becomes too dense and the surface becomes hard to obtain elasticity, and the torque rises or the margin for device precision is lost.

The single thread resistance value of the yarn 40 is preferably in the range of 10 ⁵ Ω / cm to 10 ¹² Ω / cm. When the resistance value is larger than 10 ¹² Ω / cm, electric charges remain in the yarn 40, and the toner 32 easily adheres, and clogging and torque tend to increase. If the resistance value is too large, frictional charging is likely to occur, the amount of charge of the toner 32 is increased, and the adhesion force to the yarn 40 is increased, which leads to clogging. Then, the insulating property of the feed roller 34 itself becomes high, making it difficult to supply toner by an electric field. In addition, when the resistance value is low, the voltage applied to the shape roller (development bias) is affected, so that too low resistance value is also a problem.

The single yarn decitex of the yarn 40 is preferably in the range of 1 decitex to 10 decitex. The decitex value is 1/10 of the tex value (tex: g / km), which is the weight of the fiber per unit length, and the larger the decitex value, the larger the linear diameter, the rigidity, and the shape of the stem to the developing roller 33 are. It is easy to produce peeling, and it is easy to produce an image defect. In addition, when the decitex value is reduced, the linear diameter becomes thinner, and the reset effect of the toner 32 on the developing roller 33 by the supply roller 34 is reduced, and the developing ghost phenomenon, which is a stain of the developing roller period, is generated. It becomes easy to do it. For this reason, it is necessary to set the line diameter suitable for the material and the amount of encroachment by the developing roller.

From the past experiences of the present inventors, it has been found that in 1.5 denier (1.67 decitex), a fiber length of 0.7 mm to 1.5 mm can be used. In 7 denier (7.78 decitex), it turns out that the fiber length is 1.2 mm-2.0 mm front and back. Moreover, it turns out that the range of -0.1mm-0.7mm is preferable as an amount of erosion. The minus sign means that the tip of the yarn 40 is separated from the surface of the developing roller 33.

FIG. 7 compares the supply roller 34 as the hair-growing roller according to the present embodiment and the conventional sponge roller in comparison with the transition of the number of copies of the blur on the photosensitive member on the sponge roller. As the supply roller 34, diameter 15.7 mm, the yarn 40 is 3d (denier), the length 1.2 mm, the core 41 is made of stainless steel (SUS), and 10 ⁷ Ω is obtained as the resistance value. It can be seen that the hauling roller improves the blur on the photosensitive member as compared to the sponge roller.

8 shows the comparison of the concentration difference between the leading end and the rear end in the supply roller 34 and the sponge roller when printing the black "beta black" region. It can be seen that the tuft roller 34 is stabilized. Even after the printing of 8000 sheets, the feeding roller 34 has no deterioration in the surface state, and the resistance value is also maintained at 10 ⁷ ?

Fig. 9 shows, as a parameter, the amount of encroachment (mm) of the feed roller 34 to the developing roller 33, which is a tuft roller, of the photosensitive member as a parameter for the number of copies of the cloudy concentration. When the encroachment amount is-(minus), the surface of the yarn material 40 is separated from the surface of the developing roller 33.

10 to 12 show various characteristics as parameters by the amount of encroachment (mm) of the feed roller 34, which is a tuft roller, to the developing roller 33. As shown in FIG. Fig. 10 shows the photoconductor blur density after 1000 sheets of printing, and Figs. 11 and 12 show the followability of the supply roller 34 with respect to the image density at the "beta black" leading end and the rear end, respectively, and the density difference thereof. do.

FIG. 13: shows the transition with respect to the number of sheets of the density difference with a "beta test" front end using the amount of erosion (mm) of the feed roller 34 which is a tuft roller to the developing roller 33 as a parameter.

In Fig. 12 and the like, it has been found that the toner follows the developing roller 33 at an initial stage of the enveloping amount of -0.4 mm, i.e., the non-contacting contact with the developing roller 33. However, if the running is continued, the followability of the toner decreases in the case of non-contact, and even if a predetermined density is obtained at the image leading end, the density cannot be maintained at the rear end. Therefore, it can be said that it is preferable to stay at about 0.1 mm for a non-contact.

A good result is obtained in about 0.35 mm of erosion amount. In other words, when a good result is obtained at 0 to 0.35 mm, and 0.35 mm is considered to be the center, it is estimated that a good result is obtained up to about 0.7 mm.

As the dry nonmagnetic-based toner 32 used in this embodiment, for example, a polyolefin resin having a cyclic structure can be used as the binder resin, as disclosed in Japanese Patent Laid-Open No. 9-101631. The toner disclosed in this publication contains a binder resin, a colorant, and a charge adjuster as main components. The binder resin is at least one selected from polyester resins, epoxy resins, polyolefin resins, vinyl acetate resins, vinyl acetate copolymer resins, styrene acrylic resins and other acrylic resins, based on 1 to 100 parts by weight of the cyclic polyolefin resin. It contains 0-99 weight part of resin. The polyolefin resin having a cyclic structure has at least one functional group selected from carboxyl groups, hydroxyl groups and amine groups, and has a structure crosslinked by ionomers or dienes.

As the toner having such a binder resin, carbon black, diazo yellow, phthalocyanine blue, quinacridone, carmine 6B, monoazo red, perylene and the like can be used as the binder. Examples of charge control agents include nigrosine dyes, fatty acid-modified nigrosine dyes, metal-containing nigrosine dyes, metal-containing fatty acid-modified nigrosine dyes, chromium complexes of 3,5-di-tert-butylsalicylic acid, quaternary ammonium salts, triphenylmethane dyes, Azochrome complex etc. can be used.

As the toner, for example, a low molecular weight polyolefin wax as disclosed in Japanese Patent Application Laid-open No. Hei 9-43891 may be included as a functioning agent. By including olefin waxes selected from homopolymers of α-olefins, copolymers of α-olefins and copolymers of α-olefins and cycloolefins as functioning agents, fixability, offset prevention properties, and heat responsiveness are improved. It is expected to let.

Toners containing a cyclic polyolefin resin as a binder resin include, for example, amine waxes, carnauba waxes, higher fatty acids and esters thereof, and higher fatty acid metals as functional imparting agents, as disclosed in Japanese Patent Application Laid-Open No. 2000-284528. It may also comprise at least one kind of wax selected from soaps, partially kenned higher fatty acid esters, higher aliphatic alcohols, polyolefin waxes, paraffin waxes.

The toner 32 includes a cyclic olefin resin as a binder resin, and the blade roller 33 is provided with a blade 37 for regulating the layer thickness of the toner 32 attached on the outer circumferential surface. It is done. A toner 32 containing a cyclic olefin resin as a binder resin is attached to the outer peripheral surface of the developing roller 33 to a thickness regulated by the blade 37, and smoothly from the developing roller 33 to the photosensitive drum 21. It can make a transition and develop.

According to the present invention as described above, the feed roller is provided with one or more yarns are installed on the outer peripheral surface of the roll-shaped core material, the surface of the yarn contact the surface of the developer carrier, the developer carrier and the supply roller If conditions such as an electric field between the developer, the speed ratio between the developer carrier and the supply roller, the nip width (erosion amount), and the like are appropriate, the developer is supplied from the supply roller to the developer carrier, and the supplied developer The developer having a predetermined developer layer thickness regulated by the developer regulating member and whose layer thickness is regulated can be used for developing the electrostatic latent image bearing member at a predetermined electric field in the developing region.

According to the present invention, the length of the yarn is in the range of 0.5mm or more and 3mm or less, and if the length of the yarn is longer, the density of the yarn installed by planting by the electrostatic seedling method is reduced, and when the length of the yarn is shortened, it is planted by the electrostatic seedling method. Since the density of the yarn increases, the density can be adjusted by the length of the yarn.

Moreover, according to this invention, the single yarn decitex of a yarn can be made into the range which can obtain an appropriate contact state.

In addition, according to the present invention, since the yarn has electroconductivity and electrical conductivity with the core, it is possible to apply electric charges to the developer in contact with the yarn from the supply roller.

In addition, according to the present invention, since the single yarn resistance value of the yarn is in the range of 10 ⁵ Ω / cm or more and 10 ¹² Ω / cm or less, appropriate charge can be given to the developer in contact with the yarn from the supply roller.

Moreover, according to this invention, since the yarn is manufactured by the composite spinning method, electroconductivity, a mechanical property, etc. can be provided suitably.

In addition, according to the present invention, it is possible to maintain the difference between the voltage applied to the developer carrying member and the supply roller in a constant range and to continue supplying the developer stably.

Moreover, according to this invention, the speed ratio of the contact part of a developer carrying body and a feed roller is 0.5 times or more, and can be maintained in the range of 2.0 times or less, and image quality can be improved.

Further, according to the present invention, the yarn of the developing roller is pushed onto the surface of the developer carrier in a range of -0.1 mm or more and 0.7 mm or less, so that the developer can be smoothly supplied to the developer carrier.

1 is a simplified cross-sectional view showing the configuration of a main part of an image forming apparatus 20 including a developing apparatus 30 which is one embodiment of the present invention;

2a and 2b are schematic front and side cross-sectional views of the feed roller 30 of FIG.

3 is an exploded perspective view of the supply roller 30 of FIG.

FIG. 4 is a diagram showing an example of conductive fibers usable as yarn 40 in the feed roller 30 of FIG.

FIG. 5 is a diagram showing an example of conductive fibers usable as yarn 40 in the feed roller 30 of FIG.

6 is a schematic cross-sectional view of the yarn 40 of FIG.

Fig. 7 is a graph showing a comparison between the supply roller 34 as the hair-growing roller according to the present embodiment and the conventional sponge roller with respect to the change in the number of copies of the blur on the photosensitive member in the sponge roller,

Fig. 8 is a graph showing a comparison of the transition of the concentration difference between the front end and the rear end when the supply roller 34 as the hair-feeding roller according to the present embodiment and the conventional sponge roller are printed with the same black "beta black" region. ,

Fig. 9 is a graph showing the transition of the number of prints of the photoconductor blur density, with the amount of erosion (mm) of the supply roller 34 as the hair-feeding roller according to the present embodiment to the developing roller 33 as a parameter;

Fig. 10 is a graph showing the photoconductor blur concentration after 1000 sheets of printing, with the amount of erosion (mm) of the feeding roller 34, which is the tuft roller, according to the present embodiment, into the developing roller 33 as a parameter.

Fig. 11 shows the followability of the feed roller 34 as the parameter of the erosion amount (mm) of the feed roller 34, which is the tuft roller, according to the present embodiment, to the developing roller 33 as a parameter. Graph plotting image density at,

Fig. 12 shows the followability of the feed roller 34 as the parameter of the erosion amount (mm) of the feed roller 34, which is the tuft roller, according to the present embodiment, to the developing roller 33 as a parameter. Graph showing concentration difference in

FIG. 13: shows the transition with respect to the number of sheets of the density difference with the "beta black" tip part as a parameter by the amount of erosion (mm) of the feed roller 34 which is a tuft roller to the developing roller 33 which concerns on this embodiment. One Graph,

14 is a simplified cross-sectional view showing the configuration of an image forming apparatus by a conventional electrophotographic method.

<Description of the symbols for the main parts of the drawings>

20: image forming apparatus

21: photosensitive drum

22: charger

30: developing device

31: toner container

32: toner

33: developing roller

34: feed roller

35, 36, 38: DC power

37: blade

40: private

41: heartwood

42: adhesive

43: seam fiber

44: conductive material

49: AC power

Claims (9)

A developing apparatus comprising a developer carrying member for developing an electrostatic latent image in a non-magnetic developer for forming an image by an electrophotographic system, and a feeding roller for feeding the developer to the developer carrying member, Feed rollers, Roller-shaped core material, It is planted on the outer circumferential surface of the core material, the tip includes one or more yarns in contact with the developer carrier, The sand material has conductivity, and has electrical conductivity with the core material, The yarn material has a single thread resistance value of 10 ⁵ Ω / cm or more and a range of 10 ¹² Ω / cm or less. The method of claim 1, The yarn is planted on the outer circumferential surface of the core material by an electrostatic weaving method, The length of this yarn is in the range of 0.5 mm or more and 3 mm or less. The method of claim 1, The yarn has a step decitex of 1 decitex or more, and the developing device, characterized in that the range of 10 decitex or less. delete delete The method of claim 1, And said yarn is a yarn produced by a composite spinning method. The method of claim 1, Further comprising a power source for applying a voltage to the developer carrier and the supply roller, respectively, A developing device characterized in that a difference between an applied voltage to a developer carrying member and an applied voltage to a supply roller is in a range of 0V to 350V. The method of claim 1, In the developer carrying member, a portion in contact with the supply roller is moved to perform the latent electrostatic image development, And a rotation mechanism for rotating the feed roller such that the speed ratio of the portion of the tip of the yarn is in the range of 0.5 times or more and 2.0 times or less with respect to the speed at which the developer carrying member moves. The method of claim 1, And the feed roller has an insertion amount in which the yarn is pushed onto the surface of the developer carrier, in a range of -0.1 mm or more and 0.7 mm or less with respect to the developer carrier.