JP2002268353A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device, which prevents overshooting of the toner density at the time of initialization of the developing device to obtain stable images from an early stage, without toner scattering and improves the operability by pulling off a sealing member usingle single action. SOLUTION: An initial developer 3 is sealed in a bag-shaped sealing member 30 and is set upstream of a pre-doctor 6b. The seal member 30 has one end part 30a, adhered to the bottom of a developing casing 2 and has the other end part 30b adhered to a toner replenishment port 8a. Using this constitution, the sealing member of a developer and toner replenishment port is extracted by one action of extracting a front end 3 of the sealing member 30, and quick toner replenishment from a toner hopper 8 is prevented in developer initialization processing, to prevent overshooting of the toner density because a developer stay part 3b can be formed, immediately after extraction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a developing device mounted on an image forming apparatus using an electrophotographic method, and a process cartridge having the same.

[0002]

2. Description of the Related Art Conventionally, a developing device having a configuration as shown in FIG. 5 has been proposed as a small and inexpensive developing device which does not require a toner supply mechanism or the like. The mechanism of toner supply will be described with reference to FIG. The developer 3a in the developer accommodating portion A located upstream of the developer first regulating member 6a changes its bulk due to increase and decrease of the toner concentration, thereby being formed before the developer second regulating member 6b. The bulk of the developer stagnation section 3b changes, and the toner hopper 8 moves the toner 11a
And toner concentration control is performed. Therefore, in this system, the toner concentration sensor can be omitted, and the toner replenishing mechanism can be simplified, so that downsizing and cost reduction can be achieved.

In the developing device, a developer preset case is set above the developer accommodating portion A so that the developer is not scattered from shipping to transportation. In use,
The seal of the developer preset case is pulled out, the developer is dropped into the developer accommodating section A, the developing device is set on a main body of a printer or the like, and the developer is initialized. In this initialization process, the driving of the main body is started, and the developer dropped in the developer accommodating portion A is conveyed by rotating the developing sleeve 4, and the developer is set around the developing sleeve 4. At this time, the toner supply port 8a from which the seal has been pulled out
, And the developing sleeve 4 and the agitator 9 are rotated for a certain time so that the toner concentration of the developer around the developing sleeve 4 becomes constant. At this time, a process of forming an image on the photoconductor 1 and consuming the toner contained in the developer to reduce the toner density is also performed. In this way, the developer initialization process is performed so that a stable image without background smear can be obtained.

However, in the above-described developer initialization processing method, the user pulls out the developer preset case and the seal member of the toner replenishing port 8a, and then sets it in the main body. The initialization is started after the detection of. At this time,
The agitator 9 in the toner hopper 8 rotates because it is driven in the same manner as the developing roller 5, so that the supply of the toner starts, and the toner density becomes higher than the target toner density, which is called “overshoot”. Occurs.

Further, if an impact or vibration occurs after the seal member on the side of the toner supply port 8a is pulled out, the toner leaks from the toner hopper 8 as shown in FIG. Things happen. Or,
There is a possibility that the toner may leak from the toner supply opening 8a by slipping through between the developing row 5 and the developing case 2. In the portion of the developing sleeve 4 to which the toner is attached, the toner density becomes high, and a problem such as background contamination temporarily occurs.
Therefore, the toner density is stabilized by forming an image on the photoconductor 1 at the time of initialization and consuming the toner. However, since the developer is not sufficiently charged, the toner density is high. There is a problem that scattering occurs. Furthermore, in the developing device, since there are two seal members at the time of shipment, a developer preset case and a toner replenishing port 8a, it is troublesome to pull them out separately. Normal operation stops.

[0006]

SUMMARY OF THE INVENTION In view of the above problems, the present invention prevents a toner density overshoot at the time of initialization of a developing device, and obtains a stable image from the beginning without causing toner scattering. It is another object of the present invention to provide a developing device which can improve the operability by making the pull-out of the seal member one-action.

[0007]

According to a first aspect of the present invention, there is provided a magnetic recording / reproducing apparatus having a magnetic field generating means therein for carrying a two-component developer containing a toner and a magnetic carrier. A developer carrier to be conveyed; a first regulating member for regulating the amount of developer; a developer accommodating chamber for accommodating the developer scraped off from the first regulating member; A toner hopper for supplying the toner to the developer carrier, and a second developer regulating member disposed further upstream than the first regulating member in the transport direction of the developer on the developer carrier. A developing device that changes the state of contact between the developer and the toner by changing the toner concentration on the developer carrying member to change the state of the developer taken up by the developer on the developer carrying member. Prep the developer upstream of the second regulating member Tsu and a developing device for theft. According to a second aspect of the present invention, in the developing device according to the first aspect, at the time of shipment of the developing device, the developer is sealed in a bag-shaped developer accommodating member provided upstream of the second regulating member. Developing device. According to a third aspect of the present invention, in the developing device according to the first or second aspect, one end of the bag-shaped developer accommodating member installed on the upstream side of the second regulating member is provided on a bottom surface of the developing case. The developing device is adhered and the other end is adhered to the toner supply port, and seals the toner supply port for feeding toner from the toner hopper to the developing sleeve.

According to a fourth aspect of the present invention, in the developing device according to any one of the first to third aspects, the developer used has a weight average diameter of 4 to 15 μm. According to a fifth aspect of the present invention, in the developing device according to any one of the first to third aspects, an alternating electric field is applied when a latent image on the image carrier is developed. According to a sixth aspect of the present invention, there is provided a developing device as set forth in any one of the first to fifth aspects, further comprising: a photosensitive member;
And a process cartridge detachably mounted on the image forming apparatus main body integrally supported with at least one means selected from the coating means.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a developing device according to the present invention. The developing device 22 is disposed on the side of the cylindrical photosensitive drum 1 which is a latent image carrier used in a copying machine, and is provided inside a developing casing 2 having an opening formed toward the photosensitive drum 1. A developer 3 composed of a toner and a magnetic carrier, partially exposed from the opening;
Sleeve 4 made of a non-magnetic material as a developer carrying member carrying the surface thereof, a magnet roller 5 as a magnetic field generating means fixedly disposed inside the developing sleeve 4, and carried on the developing sleeve 4 and conveyed. Doctor blade 6 as developer first regulating member for regulating the amount of developer
a, a developer storage case 7, a toner hopper 8 as a toner storage section, and the like. The developer accommodating case 7 has a developer accommodating portion A for accommodating the developer which is not supplied to the developing position of the portion facing the photoreceptor drum 1 and whose progress is prevented by the doctor blade 6a between the developer accommodating case 7 and the developing sleeve 4. Is formed.
The developer 3a in the developer accommodating portion A is carried on the developing sleeve 4 at a position facing the developer accommodating portion A in the magnet roller 5 fixedly disposed inside the developing sleeve 4. Are arranged. In addition, the toner hopper 8 has a toner supply port 8a adjacent to and upstream of the developer accommodating portion A in the developer transport direction and facing the surface of the developing sleeve 4. In a space adjacent to the toner supply port 8a, an agitator 9 as a toner stirring member that sends out the toner 11a in the toner hopper 8 while stirring toward the toner supply port 8a is arranged. The position of the rotating shaft and the length of the wings of the agitator 9 are adjusted so that the outermost trajectory of the agitator 9 does not swing to the developer as shown by the broken line in the figure.

In the developing device having the above structure, the developer 3a carried on the developing sleeve 4 is conveyed on the sleeve toward the doctor blade 6a with the rotation of the developing sleeve 4 rotating in the direction of arrow a in the drawing. The thickness is regulated by the doctor blade 6a. Thinned developer 3a
Is transported to a developing area facing the photosensitive drum 1 rotating in the direction of arrow b in the figure. And in the development area,
The toner is supplied to the electrostatic latent image formed on the photosensitive drum 1 in a contact or non-contact manner, and the electrostatic latent image is visualized. Thereafter, the developer 3 is conveyed over the sleeve along with the rotation of the developing sleeve 4 to the developer second regulating member, which is a developer supply port, to the pre-doctor blade 6 b side, and is sent out by the agitator 9 in the toner hopper 8. After taking in the new toner 11a supplied from the toner supply port 8a, the process returns to the developer accommodating section A. And new toner 11
In the developer 3a containing a, the internal pressure at the regulating portion by the doctor blade 6a increases, and the toner of the developer 3a is frictionally charged. As described above, the toner in the developer 3a on the developing sleeve 4 can be charged by the internal pressure of the developer in the developer accommodating portion A. Therefore, a paddle or a screw or the like for charging or stirring the developer is used. A complicated stirring and conveying mechanism is not required.

On the other hand, a part of the developer 3a, which is not supplied to the developing area and is prevented from proceeding by the doctor blade 6a,
The developer 3 moves toward the toner supply port 8 a of the toner hopper 8 due to the internal pressure and gravity of the developer 3 in the developer accommodating portion A. Developer 3 that has moved to the vicinity of toner supply port 8a
a is attracted to the developing sleeve 4 side by the magnetic force of the magnetic pole 5a, and is conveyed to the doctor blade 6a side as the developing sleeve 4 rotates, thereby circulating in the developer accommodating portion A. Further, in order to increase the stirring of the developer 3a in the developer accommodating section A, a stirring member 1 is provided in the developer accommodating section A.
3 are installed. The agitating member 13 also has the same rotation direction as the developing sleeve because it also serves as a developer regulating member on the developing sleeve 4.

In the developing device having the above structure, when the amount of toner supplied to the developer 3a increases and the toner concentration increases, the volume of the developer 3a increases accordingly. At 8a, the developer overflows from the inside of the developer accommodating section A and closes the pre-doctor blade 6b. Thus, the amount of the developer 3a on the developing sleeve 4 taken into the developer 3a is reduced. Due to this decrease in the amount of toner taken in, the toner concentration of the developer 3a is always kept below a certain concentration. Conversely, when the toner concentration of the developer 3a decreases, the bulk of the developer 3a decreases.
b, the developer 3 on the developing sleeve 4 is removed.
A predetermined amount of toner is taken into a, and the toner density of the developer 3a is always maintained at a certain level or more. As described above, since the toner density can be controlled within a substantially constant range, complicated toner density control using a toner density sensor, a supply member, or the like is not required.

In the conventional developing device, the developer is dropped into the developer accommodating section A by pulling out a seal from a preset case of the developer provided above the developer accommodating section A, and then set in the main body. As a result, the developer in the developer accommodating portion A is transported to the developing sleeve 4 and stays upstream of the pre-doctor blade 6b to form the developer staying portion 3b. Due to the formation of the developer retaining portion 3b,
Since toner replenishment is restricted to stabilize the toner concentration, the shorter the time required for the developer stagnation portion 3b to reach the normal amount, the faster the target toner concentration can be achieved. Therefore, the developing device of the present invention has a configuration in which the initial developer is preset on the upstream side of the pre-doctor blade 6b. As a result, the developer stagnation portion 3b can be formed in advance on the upstream side of the pre-doctor blade 6b from the time of shipment, so that the toner hopper 8 is not abruptly replenished with toner, but is subjected to an initialization process for consuming toner. Without overshooting.

As a method for presetting the initial developer, as shown in FIG. 1, there is a method in which the initial developer 3 is sealed in a bag-shaped seal member 30 and installed upstream of the pre-doctor blade 6b. One end 30 of the sealing member 30
a is adhered to the bottom surface of the developing casing 2 and the other end 30b is adhered to the toner supply port 8a. The toner supply port side end 30b of the seal member 30 also serves as a seal member on the toner supply port 8a side by closing the toner supply port 8a.
With such a configuration, it is possible to prevent the developer from leaking due to impact, vibration, or the like between the time of shipment and the time of transportation, and also to prevent the toner from moving to the developing sleeve 4 side through the toner supply port 8a.

The pulling out of the seal member 30 is performed as follows. As shown in FIG. 1, a tip 30c for pulling out the seal member 30 extends out of the developing device through a gap provided in the developer accommodating portion A. By pulling out this, a developer stagnant portion 3b of the initial developer 3 is formed. The gap between the developer accommodating portions A is provided with an elastic seal member 31 such as a sponge, so that the developer 3 does not leak and the initial developer can be securely removed from the bag-shaped seal member 30. 3 can be drained. Also, as a method of pulling out the tip 30c of the bag-shaped seal member 30, it is difficult to pull out the entire width at once,
As shown by an arrow in FIG. 2, the developing device 22 may be pulled out from either the left or right side in the longitudinal direction.

In the developing device of the present invention, a developer having a weight average diameter of 4 to 15 μm can be used in order to improve the resolution of an image. The method for measuring the weight average diameter of the developer is performed according to the following procedure. First, as an electrolytic aqueous solution,
NaCl aqueous solution adjusted to 1 wt% 100-150 ml
And 0.1 to 5 ml of a surfactant (preferably an alkylbenzene sulfonate) is added as a dispersant. Next, 2 to 20 mg of the measurement sample is weighed and added. The electrolytic aqueous solution in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser, and the volume and the number of the toner particles or the toner are measured using a 100 μm aperture as an aperture by a weight average diameter measuring device. Then, the volume distribution and the number distribution are calculated. From the obtained distribution, the weight average particle diameter (D4) and the number average particle diameter of the toner are determined. As a measurement channel, 2.00 to less than 2.52 μm,
3. less than 17 μm, 3.17 to less than 4.00 μm,
00 to less than 5.04 μm, 5.04 to less than 6.35 μm, 6.35 to less than 8.00 μm, 8.00 to 10.0
11. less than 8 μm, 10.08 to less than 12.70 μm,
70 to less than 16.00 μm, 16.000 to 20.20 μm
m, 20.20 to 25.40 μm, 25.40
13 channels of 32.00 μm or less and less than 40.30 μm, and a particle size of 2.00 μm or more
For particles less than 0.30 μm.

The materials constituting the developer will be described below. The composition of the toner contained in the developer is 75 to 93% of the binder resin, 3 to 10% of the colorant, and 3 to 3% of the release agent.
-8%, and other components are 1-7%. Examples of the binder resin include polystyrene, poly-p-chlorostyrene, a homopolymer of styrene such as polyvinyltoluene and a substituted product thereof, or a styrene-p-chlorostyrene copolymer or styrene-vinyltoluene copolymer. Copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl Methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone and the like can be used. As the colorant, an inorganic or organic dye / pigment can be used. For example, carbon black, aniline black, acetylene black,
Naphthol Yellow, Hansa Yellow, Lodamun Lake, Alizarin Lake, Bengala, Phthalocyanine Blue, Induslen Blue and the like. If necessary, a magnetic material can be used as a coloring agent.
As a magnetic material, magnetite, γ-iron oxide, ferrite iron, iron oxide such as excess ferrite, or
Magnetic metals such as iron, cobalt, nickel, or
Iron oxide or magnetic metal, cobalt, tin, titanium, copper,
A composite metal oxide alloy with a metal such as lead, zinc, magnesium, manganese, aluminum, and silicon, or a mixture thereof may be used.

These magnetic particles have an average particle size of 0.05 to
It is preferably in the range of 1.0 μm, more preferably in the range of 0.1 to 0.6 μm, even more preferably,
It is in the range of 0.1 to 0.4 μm. These magnetic particles preferably have a BET specific surface area measured by a nitrogen adsorption method in the range of 1.0 to ²⁰ m ² / g, particularly 2.5 to ¹² m ² / g.
/ G within the range, and the Mohs hardness is 5 to 5.
7 is preferable. Examples of the shape of the magnetic particles include an octahedron, a hexahedron, a sphere, a needle, and a scale.
A tetrahedron, a hexahedron, and a sphere having little anisotropy are preferable.
When used as a magnetic toner, the magnetic toner particles preferably contain 10 to 150 parts by mass, preferably 20 to 120 parts by mass of a magnetic material with respect to 100 parts by mass of the binder resin.

The developer used in the developing device of the present invention may contain a small amount of an additive within a range that does not substantially adversely affect the developer. As the additive, for example, a lubricant powder such as Teflon powder, zinc stearate powder, polyvinylidene fluoride powder, or an abrasive such as cerium oxide powder, silicon carbide powder, strontium titanate powder, or titanium oxide powder Fluidity-imparting agents such as aluminum oxide powder, or anti-caking agents, or carbon black powder, zinc oxide powder, conductivity-imparting agents such as tin oxide powder, and organic fine particles or inorganic fine particles of the opposite polarity. Can be Further, a release agent can be added to improve the fixing property and the like. Examples of the release agent include paraffin wax and its derivatives, microcrystalline wax and its derivatives, Fischer-Tropsch wax and its derivatives, polyolefin wax and its derivatives, carnauba wax and its derivatives, and the like. Derivatives include oxides, block copolymers with vinyl monomers, and graft-modified vinyl monomers. In addition, alcohols, fatty acids, acid amides, esters, ketones, hydrogenated castor oil and derivatives thereof, vegetable waxes, animal waxes, mineral waxes, petrolactam and the like can also be used.

As the charge controlling agent for controlling the toner to be negatively charged, for example, organometallic complexes and chelate compounds are effective, and monoazo metal complexes, acetylacetone metal complexes,
Examples thereof include an aromatic hydroxycarboxylic acid-based metal complex and an aromatic dicarboxylic acid-based metal complex. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, their anhydrides, their esters, and phenol derivatives such as bisphenol. Examples of the charge control agent for controlling the toner to be positively charged include denaturation products of nigrosine and fatty acid metal salts, and quinones such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate. Onium salts such as quaternary ammonium salts and their analogs, such as phosphonium salts, and their lake pigments, triphenylmethane dyes and these lake pigments (as the lake-forming agent, phosphotungstic acid, phosphomolybdic acid, phosphorous tungsten Molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide,
Ferrocyanide) and the like. The number average particle size of the particulate charge control agent is preferably 4 μm or less,
More preferably, it is 3 μm or less. When these charge control agents are internally added to the toner particles, the binder resin 100
Preferably, it is contained in an amount of 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass with respect to parts by mass.

Further, if necessary, additives for toner generally used widely, for example, fluidizing agents such as colloidal silica, metal oxides such as titanium oxide and aluminum oxide, and abrasives such as silicon carbide And a lubricant such as a fatty acid metal salt. The inorganic fine powder is preferably used in an amount of 0.1 to 2% by weight based on the toner. If the amount is less than 0.1% by weight, the effect of improving toner aggregation is poor. If the amount is more than 2% by weight, problems such as toner scattering between fine lines, contamination inside the machine, scratches and abrasion of the photoreceptor tend to occur. Because there is.

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

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

As the core particles of the carrier constituting the developer, conventionally known particles may be used. For example, ferromagnetic metals such as iron, cobalt and nickel, alloys and compounds such as magnetite, hematite and ferrite, or A composite of the ferromagnetic fine particles and a resin is exemplified. It is preferable that the surface of these carriers is coated with a resin for the purpose of increasing the durability. Examples of the resin forming the coating layer include polyolefin resins such as polyethylene, polypropylene, chlorinated polyethylene, and chlorosulfonated polyethylene, or polystyrene, polymethacrylate, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, and polystyrene. Vinyl chloride, polyvinyl carbazole,
Polyvinyl and polyvinylidene resins such as polyvinyl ether and polyvinyl ketone, or vinyl chloride-vinyl acetate copolymers, silicone resins comprising organosiloxane bonds or modified products thereof (for example, alkyd resins,
Modified products of polyester resin, epoxy resin, polyurethane, etc.) or polytetrafluoroethylene,
Examples include fluorine resins such as polyvinyl fluoride, polyvinylidene fluoride, and polychlorotrifluoroethylene; amino resins such as polyamide, polyester, polyurethane, polycarbonate, and urea-formaldehyde resin; and epoxy resins. Of these, silicone resins or modified products thereof and fluororesins are preferred in terms of preventing toner spent, and silicone resins or modified products thereof are particularly preferred. The coating layer may be formed by a conventionally used means such as a method of spraying or dipping a coating layer forming liquid on the surface of the carrier core particles. Further, the thickness of the coating layer is preferably 0.1 to 20 μm.

[0025]Example of manufacturing dry two-component developer  Hereinafter, a production example of a dry two-component developer will be described. First, Table 1
Melt and knead the mixture of the formulation shown in, then pulverize and classify
Thus, mother colored particles were obtained.

[Table 1] Further, 0.3 parts by weight of hydrophobic silica was mixed with 100 parts by weight of the base colored particles to obtain a toner having an average particle diameter of 9.0 μm.

On the other hand, 2 parts by weight of polyvinyl alcohol and 60 parts by weight of water were added to 100 parts by weight of magnetite prepared by a wet method in a ball mill, and mixed for 12 hours to prepare a magnetite slurry. This slurry was spray-granulated with a spray drier to obtain spherical particles.
The particles were fired in a nitrogen atmosphere at a temperature of 1000 ° C. for 3 hours, and then cooled to obtain core particles. Subsequently, a mixture having the formulation shown in Table 2 was dispersed with a homomixer for 20 minutes to prepare a coating layer forming liquid.

[Table 2] Using a fluidized bed type coating apparatus, the above-mentioned coating layer forming liquid was coated on the surface of 1,000 parts by weight of the core particles obtained above to obtain a silicone resin-coated magnetic carrier.

With respect to 97.5 parts by weight of the magnetic carrier,
The previously prepared toner was mixed at a ratio of 2.5 parts by weight to obtain a dry two-component developer.

The developing device of the present invention uses the following power supply. FIG. 3 is a diagram illustrating a power supply of the developing device of the present embodiment. An oscillating bias voltage in which an AC voltage is superimposed on a DC voltage is applied to the developing sleeve 4 as a developing bias by a power supply 26. The background potential and the image potential are
It is located between the maximum value and the minimum value of the oscillation bias potential. As a result, an alternating electric field whose direction changes alternately is formed in the developing device 22. The toner and the carrier of the developer violently vibrate in the alternating electric field, and the toner flies off the photosensitive drum 1 by shaking off the electrostatic restraining force on the developing sleeve 4 and the carrier, and corresponds to the latent image on the photosensitive drum 1. And adhere. The difference (peak-to-peak voltage) between the maximum value and the minimum value of the oscillation bias voltage is preferably 0.5 to 5 KV, and the frequency is 1 KV.
-10 KHz is preferred. The waveform of the oscillation bias voltage is
A rectangular wave, a sine wave, a triangular wave, or the like can be used. As described above, the DC voltage component of the vibration bias is a value between the background portion potential and the image portion potential. However, a value closer to the background portion potential than the image portion potential is more likely to cover the background portion potential region. It is preferable from the viewpoint of preventing toner from adhering. Further, when the waveform of the oscillation bias voltage is a rectangular wave, the duty ratio is desirably set to 50% or less. Here, the duty ratio is a ratio of a time during which the toner goes to the photoconductor in one cycle of the vibration bias. By doing so, the difference between the peak value of the toner going to the photoreceptor and the time average value of the bias can be increased, so that the movement of the toner is further activated, and the potential of the toner on the latent image surface is increased. It adheres faithfully to the distribution and can improve roughness and resolution. Also, since the difference between the peak value of the carrier having the opposite polarity to the toner and the time average value of the bias toward the photoreceptor can be reduced, the motion of the carrier is calmed down, and the background portion of the latent image is reduced. Can significantly reduce the probability that the carrier adheres to the substrate.

FIG. 4 is a schematic structural view of a process cartridge provided with the developing device of the present invention. The process cartridge 20 is configured by integrally combining one or both of the charging device 21 and the cleaning device 23 in addition to the photoreceptor 1 and the developing device 22, and is used for an image forming apparatus main body such as a copying machine or a printer. It is configured so that it can be attached and detached. The process cartridge provided with the developing device of the present invention operates as follows. The photoreceptor 1 is driven to rotate at a predetermined peripheral speed, and the peripheral surface thereof is uniformly charged at a predetermined positive or negative potential by a charging unit 21. Then, an image exposure unit such as a slit exposure or a laser beam scanning exposure (not shown) is used. , And sequentially forms an electrostatic latent image on the peripheral surface of the photoconductor 1. The formed electrostatic latent image is then subjected to toner development by the developing unit 22, and the developed toner image is transferred onto a transfer material (not shown) fed from a paper supply unit (not shown) in synchronization with the rotation of the photoconductor 1. The images are sequentially transferred by the transfer unit. The transfer material having undergone the image transfer is separated from the surface of the photoreceptor 1 and introduced into image fixing means (not shown) to fix the image, and is discharged out of the apparatus as a copy. Photoreceptor 1 after image transfer
The surface is cleaned by removing the transfer residual toner by the cleaning unit 23, and is further subjected to static elimination. Then, the surface is repeatedly used for image formation.

[0030]

As described above, according to the present invention, by presetting the initial developer upstream of the pre-doctor blade, it is possible to form a developer stagnant portion upstream of the pre-doctor blade from the time of shipment. Also, it is possible to provide a developing device capable of preventing the toner concentration of the developer on the developing sleeve from overshooting without abrupt toner replenishment from the toner hopper in the developer initialization processing. In addition, the initial developer is sealed in the bag-shaped seal member and installed, and one end is adhered to the bottom surface of the developing casing and the other end is adhered to the toner supply port, so that the seal member also functions as a seal member on the toner supply port side. Thus, it is possible to provide a developing device with improved operability that can pull out the seal member of the developer and toner supply port with one action.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a developing device according to the present invention.

FIG. 2 is a diagram illustrating a method of pulling out a tip of a seal member from a developing device.

FIG. 3 is a diagram illustrating a power supply of the developing device.

FIG. 4 is a schematic configuration diagram of a process cartridge provided with a developing device of the present invention.

FIG. 5 is a schematic configuration diagram of a conventional developing device.

FIG. 6 is a diagram showing toner leakage from a toner hopper in a conventional developing device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoconductor 2 developing casing 3, 3 a developer 3 b developer retaining portion 4 developing sleeve 5 magnet roller 5 a magnetic pole 6 a developer first regulating member (doctor blade) 6 b developer second regulating member (pre-doctor blade) 7 Developer storage case 8 Toner hopper 8a Toner supply port 9 Agitator 11a Toner 13 Developer stirring member 20 Process cartridge 21 Charging means 22 Developing device (Developing means) 23 Cleaning means 26 Power supply 30 Bag-shaped seal member 30a, 30b End 30c Tip 31 Seal member A Developer storage section

Claims (6)

[Claims] 1. A developer carrier having a magnetic field generating means therein for carrying and transporting a two-component developer including a toner and a magnetic carrier, a first regulating member for regulating the amount of the developer, A developer accommodating chamber for accommodating the developer scraped off by the first regulating member; and a toner hopper for supplying toner to the developer carrier adjacent to the developer accommodating chamber; A second developer regulating member disposed on the upstream side of the developer carrying direction with respect to the developer carrying member, and changes a contact state between the developer and the toner by a change in a toner concentration on the developer carrying member. A developing device for changing the toner intake state of the developer on the developer carrier by changing the developing device, wherein the developer is preset upstream of the second regulating member when the developing device is shipped. . 2. The developing device according to claim 1, wherein at the time of shipment of the developing device, the developer is sealed in a bag-shaped developer accommodating member provided upstream of the second regulating member. Characteristic developing device. 3. The developing device according to claim 1, wherein one end of a bag-shaped developer accommodating member installed upstream of the second regulating member is adhered to a bottom surface of the developing casing. One end of the developing device is adhered to the toner supply port, and seals the toner supply port for feeding the toner from the toner hopper to the developing sleeve. 4. The developing device according to claim 1, wherein the developer used has a weight average diameter of 4 to 15 μm. 5. The developing device according to claim 1, wherein an alternating electric field is applied when developing the latent image on the image carrier. 6. An image forming apparatus according to claim 1, wherein said developing device is supported integrally with a photosensitive member and at least one means selected from a charging means and a cleaning means. A process cartridge that is detachable from the main unit.