JP3483480B2 - Developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention
Copier, laser beam printer, facsimile,
The present invention relates to a developing device used for a printing device or the like. [0002] 2. Description of the Related Art Conventionally, uniform charging has been performed on an electrostatic latent image carrier.
After exposure to analog exposure or semiconductor laser or LED
Image exposure to form an electrostatic latent image on the electrostatic latent image carrier
After the formation, this electrostatic latent image is converted into a developer image by a developing device.
After the developer image is transferred to a transfer material,
The material is separated from the electrostatic latent image carrier and sent to the fixing device.
The developer image is fixed on the transfer material in the
2. Description of the Related Art An image forming apparatus that outputs an image is known. Here, the image forming process will be described with reference to FIG.
I will tell. FIG. 13 is a sectional view of a main part of the image forming apparatus.
The image forming apparatus is, for example, a photosensitive
The photosensitive drum 1 has an OP on its surface.
A photoconductive layer of C, a-Si, etc.
Be moved. The surface of the photosensitive drum 1 is
For example, it is uniformly charged to, for example, -700V. Then, the image signal
Exposure on photosensitive drum 1 by performing image exposure 12 based on information
Attenuates the surface potential of the section to, for example, -200 V
A latent image corresponding to the image signal of the image is formed on the system 1. still,
The image exposure 12 includes, for example, a semiconductor laser or an LED array.
Is used. Next, a developing device which is a one-component developing device for developing a latent image
2 and visualized as a toner image. In addition, dry type
A developing device using a one-component developer is simple and exchanges a carrier or the like.
It has a high durability and a long service life because no replacement is required.
For example, jumping current using magnetic one-component toner
An image or the like is employed. [0006] The developing device 2 has a negatively charged black toner.
Is used for development, and the developer
DC bias of about -500V as a developing bias.
Apply latent image to reverse develop latent image and visualize as toner image
Become Then, if necessary, post-charger (charge
Pretreatment (usually DC or A)
Addition of corona by C or combination with light elimination etc.
The toner image on the transfer material supplied to the photosensitive drum 1.
The image is transferred by the transfer charger 4. And toner
The transfer material on which the image has been transferred is sent to the fixing device 7 to form a toner image.
A desired image is obtained by fixing to a transfer material. still,
The transfer residual toner on the photosensitive drum 1 is transferred to the cleaning device 6.
Therefore, it is removed and prepared for the next image formation. [0007] By the way, in order to increase the speed of the image forming apparatus,
Indicates the development using a two-component magnetic brush in the developing device.
A plurality of developing rolls of the apparatus can be used (Japanese Unexamined Patent Publication No.
204084), the distance between the developing sleeve and the photosensitive member.
Move the separation closer to the downstream developing sleeve and
The toner supply amount is made uniform (Japanese Patent Laid-Open No. 2-18 / 1990).
8778). [0008] SUMMARY OF THE INVENTION
The conventional developing device has the following problems. That is, a plurality of developer carriers (developing sleeves)
Although a developing device having a
Multiple developing devices are φ30mm and φ20mm or φ20m
Different outer diameters such as a combination of m and φ16mm
In many cases, a developing sleeve is used. This is mainly developed
This is because the functions are separated into those for development and those for secondary development.
The auxiliary development is intended to supplement the main. That
Development sleeve to reduce costs as much as possible
It has a small diameterAsThe following problems occur in a simple system
was there. [0010] 1. Upstream developing sleeve and downstream developing sleeve
Development characteristics due to differences in development nip due to differences in diameter
But common development for space saving and cost reduction
When using a bias, the developability differs for each developing sleeve.
In other words, since the developability differs for each developing sleeve, the density
He had difficulties. This is because digital images and
Gradation of images and stabilization of gradations corresponding to roughening
It was at odds with sexual demands. This developability
The difference is that the larger the developing sleeve diameter, the
This is because the width of the development area formed between
You. This phenomenon is due to the low charge amount of toner
This is particularly noticeable when a one-component toner is used. 2. Also, developing with a plurality of developing sleeves
When the outer diameter of the developing sleeve is different,
The number of times of passing through the toner layer thickness regulating member in the developing sleeve is different
The degree of friction on the sleeve surface is different
And the service life is different due to the different degree of shaving of the coating material
(The smaller the diameter, the more times the blade passes
Life is short). Therefore, maintenance of replacement of the developing sleeve
Service intervals are different, and servicemen frequently visit users
Service costs were also rising because of the need. 3. Sleeve generated by developing sleeve pitch
In addition to ghost images, high-speed aircraft are fast
The development time is too short and the development time is not sufficient
As a result, the developability is unstable and the density varies greatly.
Had become. [0013] Therefore, solving the above problems simultaneously
Was difficult. Therefore, the first object of the present invention is to
Recent digital images and images compatible with graphics
Can meet the requirements of gradation and gradation stability
An object of the present invention is to provide a developing device. The second object of the present invention is as follows.Tona
-CarrierServiceman by standardizing the service life of
Maintenance costs and service costs
An object of the present invention is to provide a developing device capable of reducing the number of developing devices. Further, a third object of the present invention is that
While preventing the occurrence of leave ghost images,
Developing device that can stabilize developability and density
To provide a location. [0017] Means for Solving the Problems To achieve the above object,
,BookThe invention is directed to the rotation direction of the electrostatic latent image carrier.Side by side
And can rotate in the same directionMultiple outside diametersToner carrying
And a plurality of toners corresponding to the plurality of toner carriers.
A blade for regulating the layer thickness of the toner on the carrier,With
AndEach toner carrierNon-magnetic around the inner magnetic member
Material and coating material covering itAnd each
The rotation speed of the carrierIn the developing device,
PreviousNoteResin constituting the printing memberWeight of B, resin
Graphite and conductive carbon mixed with water
If the weight of titanium oxide and conductive carbon is P
Weight of the coating member of the toner carrier with a small outer diameter
Coating of toner carrier having a large outer diameter with a quantity ratio of P / B
The weight ratio of the members was smaller than P / B.Characterized by
You. [0018] [0019] [0020] [0021] [0022] Embodiments of the present invention are attached below.
Description will be given based on the drawings. <Embodiment 1> FIG. 3 shows a developing device according to the present invention.
FIG. 2 is a cross-sectional view of a main part of the image forming apparatus including the apparatus,
The image forming apparatus has a process speed of 450 mm / sec.
A black and white digital copier capable of outputting 82 sheets per minute.
A-Si photosensitive drum having a diameter of 108 mm
1 is used. a-Si is more attractive than organic photoreceptor
OP is as large as about 10 and the charging potential is relatively low.
Although latent image potential is not sufficient compared to C, high durability and long life
It is suitable for high-speed machines because there are more than 3 million
Have signs. The photosensitive drum 1 is, for example,
After being uniformly charged to 500 V, image exposure at 600 dpi
12 is made. Image exposure 12 uses semiconductor laser as light source
As a first laser modulated by a first image signal
The first laser beam is driven by a motor.
Polarized by a polygonal mirror rotating at a constant rotation speed,
After being reflected by the turning mirror
1 is raster-scanned, and the surface potential of the exposed portion is
Attenuates to + 100V to form an image-like latent image on photosensitive drum 1.
To achieve. The wavelength of the laser beam is 680 nm.
You. Thereafter, the latent image formed on the photosensitive drum 1
Is developed by the developing device 2 to form a visible image as a toner image.
Become Thus, the electrostatic latent image is developed by the developing device 2 and
After being visualized as a toner image, the post charger 10 (see FIG. 3)
), The total current (AC + DC) -200μA
-After the image is charged, the transfer material is easily transferred and separated.
And a toner image is formed on the transfer material supplied to the photosensitive drum 1.
The transfer is performed by the transfer charger 4. Then, the toner image is transferred.
The transferred transfer material is sent to the fixing device 7 to transfer the toner image to the transfer material.
To obtain a desired image. In addition, photosensitive
The transfer residual toner on the ram 1 is removed by the cleaning device 6.
It is removed and prepared for the next image formation. In this embodiment, the developing device 2 has a simple structure.
Easy maintenance with up to 2000k development sleeve life
Unnecessary and highly durable black magnetic one-component developer
The used development is performed. Incidentally, the toner is a negative toner,
Its particle size is 8.5 μm. In this embodiment, a plurality of developers are used.
Regular development using the carrier (developing sleeve) 20, 30
Do. In the toner supply operation, the vicinity of 2B shown in FIG.
When the toner runs out, the signal from the piezoelectric element 22
The magnet roll 24 is driven to rotate, and this magnet
By the rotation of the troll 24, the toner is discharged from the hopper 9B.
It is supplied into the developing device 2. Next, details of the developing device 2 according to the present invention will be described.
Will be described with reference to FIGS. FIG. 1 shows the present invention.
FIG. 2 is a sectional view of the developing device, and FIG.
FIG. In the developing device 2 according to the present embodiment,
High durability and high reliability with simple maintenance and no maintenance required
And a one-component magnetic toner having high productivity and a negative polarity was used. As shown in FIG.
The two developer sleeves 20 and 30 are used as developer carriers.
The first developing sleeve 20 is provided with a non-magnetic member.
On aluminum A2017 with a diameter of 30 mm
After blasting with FGB # 600,
It is constructed by coating. Also, the second
The developing sleeve 30 is also a non-magnetic member having a diameter of φ20.
mm A2017 on FGB # 600
It is composed by blasting and coating
You. In addition, this coating is aluminum (Al) surface
Forming a film that protects the
While preventing sleeve ghost images from occurring,
It is applied to increase the durability of the leave surface. Incidentally, the first developing sleeve 20 is
4And 6 poles (N1 to N3, S1 toS
3) Built-in fixed magnet with magnetic field pattern
ing. [0032]Further, the first developing sleeve 20 is
It rotates at a speed of 50% and is carried on the developing sleeve 20.
The thickness of the toner is regulated by the magnetic blade 20A.
Gap S-Bga between image sleeve 20 and magnetic blade 20A
p is set to 250 μm. And the first development
The gap S-Dgap between the sleeve 20 and the photosensitive drum 1 is 20
0 μm, and +200 V
DC bias and Vpp 1200V as shown in FIG.
A square wave of several 2.5 kHz is applied as an AC bias
The magnetic one-component non-contact development is performed. Therefore,
Trust fog removal (300V in the flight direction)
(Return) The contrast becomes 100V. As the second developing sleeve 30, a non-magnetic portion
Film on aluminum A2017 with diameter φ20mm
Is used, and inside it is a figure4And Table 2
Magnetic field pattern of 4 poles (N1, N2, S1, S2) shown in
Is provided. [0034] +200 V DC bias is applied to the second developing sleeve 30
And Vpp of 1200V and frequency of 2.5kHz shown in FIG.
Although a shape wave is applied, the second developing sleeve 30
One developing sleeve 20 is the same and common, and has one power supply.
Cost can be reduced and space for power supply can be reduced.
It has the advantage of requiring less. The second developing sleeve 30 is attached to the photosensitive drum 1
The developing sleeve 30 at a speed of 150%
The thickness regulation of the toner carried on the magnetic blade 30A
This is done. Then, the second developing sleeve 30 and the magnetic
The gap S-Bgap with the air blade 30A is 250 μm,
The gap S-Dgap between the image sleeve 30 and the photosensitive drum 1 is 2
It is set to 00 μm. By the way, the magnetic blades 20A and 30A
Both are 1.0 mm thick plate-like magnetic blades,
These magnetic blades 20A and 30A are configured in the same manner.
Setting the same development conditions as possible
To compensate for concentration fluctuations caused by the environment and durability.
Positive becomes possible. Thus, digital images and graphics in recent years have
To meet the demand for gradation stability of images corresponding to
The developing characteristics of the developing sleeves 20 and 30 (first and
The most important issue is to match the (second development characteristics).
is there. For both developing sleeves 20 and 30, S-Bgap is
Since these are the same, these developing sleeves 20 and 30
The toner coat amount (M / S) is also about 1.0mg / cm^Two Same as
Be the same. The developing pole of the first developing sleeve 20 is N
2, the developing pole of the second developing sleeve 30 is S1,
The same is true for the magnetic force and half-value width. However, the circumference of both developing sleeves 20 and 30
Although the speed is the same, the actual developing characteristics are shown in FIG.
So different. This will be described below. This is shown in FIG.
If the outer diameter is different when using a leave, the developing area (developing
The size of the tip varies depending on the sleeve diameter.
As the outer diameter increases, the developing nip also increases. The developability is basically based on the toner supply amount (M /
S) and triboelectric charge per unit weight (Q / M)
And the development nip. That is, the peripheral speed of the developing sleeve
If the ratios are equal, the toner supply amount (M / S) × the tribo
(Q / M) x It is proportional to the development nip. Therefore, the development
In the case of the condition, the development nip is 5.7 mm in the first development,
The difference is 5.0 mm in the development, and this difference is the development characteristic shown in FIG.
Make a difference. In FIG. 6, the horizontal axis represents the contrast current.
The V-D characteristic shows the density in the vertical axis at the position Vcont (V).
It is. Next, the second problem, which is the development sleeve
The life will be described. In a developing sleeve having a different outer diameter,
The larger the diameter, the more the blade part
Because the number of passages is reduced, the amount of film shaving on the sleeve is small.
Absent. Therefore, the diameter is φ20 as in the case of the present embodiment.
mm and φ30mm, φ20mm is φ30mm
It can be cut about 1.6 times more than the
Although the developing sleeve has not yet reached the end of its life,
The 0 mm developing sleeve must be replaced first,
Service after replacing φ30mm developing sleeve
Costs for the developer and increase the life of the developing sleeve.
It is hoped that this will be done. This embodiment is implemented in view of the above.
It is something. Table 3 shows the film formulation (P / B) and the shaving in the conventional system.
Amount, tribo (Q / M), toner supply amount (M / S), development
Nip and toner supply amount (M / S) x tribo (Q / M)
X Indicates the value of the development nip. [0045] The formula of the film is A1 sleeve surface with phenolic resin and crystalline
100: 36: 4 weight ratio of graphite and carbon
Mix in proportions and cure at a temperature of 150 ° C with a film thickness of 10μm
The film was used. To form a stable and uniform film
The film thickness is suitably about 10 μm. In this case, the P / B ratio
Is 1 / 2.5. B is the weight of the resin, and P is less than the resin.
Weight of outer pigment (crystalline graphite + carbon)
Quantity. As can be seen from Table 3, in the conventional system, 500
In k sheets, while φ30 sleeve can be cut 6.7μm
The service life of the φ20 sleeve exceeds 10 μm. Soshi
The development nip is different and the toner
Supply amount (M / S) x tribo (Q / M) x development nip
Different values. In contrast, in the present embodiment,
Has the above problem by adopting the configuration shown in Table 4.
Was solved. [0047]The formulation of the membrane is as shown in Table 5. Resin (B) and Pygme
(P) weight ratio P / B of smaller outer diameter
Coating material with larger outer diameter
It was set smaller than that of the member. By the way, graphite
The ratio of carbon to carbon is preferably 9: 1 over the dispersibility of carbon.
No. [0048] Table 4 shows the effects of the above configuration. First, the shaving amount of 500k sheets is φ30
Φ20 sleeve, while the sleeve is 6.7 μm
Was about the same as 6.8 μm. This is shown in FIG.
This is because it has such properties. That is, FIG. 8 shows the P / B ratio
Shows the relationship between and the amount of shaving of the film. As the P / B ratio increases,
The film is easy to scrape, and on the contrary, it is hard to
I applied the nature. Next, regarding tribo (Q / M),
Φ20 sleeve, which has a small gap and poor developability, is larger
Could be done. This corresponds to the P / B ratio and
As can be seen from the relationship with the
The tribo (Q / M) becomes smaller as the pitch increases, and the P / B ratio decreases.
Uses the characteristic that the tribo (Q / M) increases when the value is reduced
It was done. By doing so, the development characteristics
Toner supply amount (M / S) x tribo (Q /
M) × Development nip value can be made almost equal.
As a result, as shown in FIG.
-There was a difference in the D curve, as shown in FIG.
The same curve could be obtained. As a result, the gradation of the image
Control of gradation stability and
The endurance life of the probe can be shared. By configuring as described above, high speed
Development system compatible with the
Developing device having a plurality of developing sleeves,
The development property can be prevented from being different for each sleeve.
Of digital image and image corresponding to graphic conversion
And the stability of the gradation can be satisfied.
Developing device having a plurality of developing sleeves
The development sleeve can have a common life,
Servicemen by eliminating the need for maintenance.
Service cost can be reduced, and the third aspect of the present invention
While preventing the appearance of sleeve ghost images,
It is possible to provide a developing device having a high density and a stable density.
did it. <Embodiment 2> Next, an embodiment of the present invention will be described.
State 2 will be described. The image forming apparatus according to the present invention is the first embodiment.
Is the same as The feature of the present embodiment is that it is harder to
By using a highly conductive material, the developing sleeve
The point is that the diameter has been further reduced to save space.
You. The developing device 2 used in the present embodiment
explain in detail. As a developer, a one-component magnetic toner of negative polarity
Is used for regular development. As shown in FIG. 1, the developing device 2
A first developing sleeve having two developing sleeves 20 and 30;
The probe 20 is a non-magnetic member made of aluminum of φ20 mm.
Blasted with AGB # 600 on A2017
After that, the coating is performed. Also, the second
The developing sleeve 30 is also a non-magnetic member of φ15 mm
Bra with FGB # 600 over aluminum A2017
It is configured by a strike treatment and coating. Ko
Ghosting occurs in the sleeve cycle
Prevents image and increases durability of sleeve surface
Done for. The first developing sleeve 20 is attached to the photosensitive drum 1.
It rotates at a speed of 150%. Toner is magnetic
The thickness of the layer is regulated by the gap 20A, and the S-Bgap is 250
It is set to μm. First developing sleeve 20 and photosensitive
The distance S-Dgap from the drum 1 was set to 200 μm,
Leave 20 has a DC bias of + 200V and is shown in FIG.
So, a square wave with Vpp 1200V and frequency 2.5kHz
Performs magnetic one-component non-contact development applied as an AC bias.
U. Therefore, the development contrast is 300 V in the flight direction,
Fog removal (toner pullback) contrast is 100V
Becomes As the second developing sleeve 30, a non-magnetic portion
Formed on aluminum A2017 of φ15mm
What has been used is used. This developing sleeve 30 has +
200V DC bias and Vpp120 as shown in FIG.
A rectangular wave of 0 V and a frequency of 2.5 kHz is applied.
Since the application means is the same as the first developing sleeve 20,
And reduced costs because only one power source is needed.
And reduced power supply space
There is. The developing sleeve 30 is 15
Rotate at 0% speed. Magnetic blur is required to regulate toner layer thickness.
S-Bgap is 250 μm, S-Dga
p is set to 200 μm, respectively. The magnetic break
The nodes 20A and 30A are the same as in the first embodiment. Next, the features of this embodiment will be described.
You. The material used in this embodiment is resin (B) and
And epoxy resin, titanium oxide as pigment (P)
(TiO_Two ) And carbon. This film is an embodiment
Durability is higher than that of the film used in 1
And has a high charge-imparting property. When using this material
The results of are shown below. Table 6 shows the film formulation (P / B) and shaving in the conventional system.
Amount, tribo (Q / M), toner supply amount (M / S), development
Nip and toner supply amount (M / S) x tribo (Q / M)
X Indicates the value of the development nip. [0062] The formulation of the film is epoxy resin and TiO2 on the A1 sleeve surface._Two
And carbon in a weight ratio of 100: 36: 4
And a film cured at a temperature of 150 ° C. with a thickness of 10 μm.
Using. The thickness for forming a stable and uniform film is 10
It is about μm. In this case, the P / B ratio is 1 / 2.5.
You. B is the weight of the resin, P is the pigment other than the resin (crystal
Weight of graphite (carbon). As can be seen from Table 6, in the conventional system, 500
While the φ20 sleeve can cut 5.2 μm in k sheets, φ
The 15 sleeve can be cut to 7.0 μm. And the development nip
Are different, and the toner supply amount (M /
S) x tribo (Q / M) x development nip are different values
Is shown. On the other hand, in the present embodiment, Table 7
The above problem is solved by adopting the configuration shown
Was. [0065] The formulation of the membrane is as shown in Table 8. Resin (B) and Pygme
(P) weight ratio P / B of smaller outer diameter
Coating member with larger outer diameter
It was set smaller than. By the way, TiO_Two And carbon ratio
Is preferably 9: 1 from the dispersibility of carbon. [0066] Table 7 shows the effects of such a configuration. First, the shaving amount of 500k sheets is φ20.
Φ15 sleeves compared to 5.2μm sleeves
Was almost the same as 5.4 μm. This is the sleeve
It means that it can no longer be cut in spite of the smaller diameter
You. Similarly, as the P / B ratio increases, the film becomes easier to scrape.
Conversely, if the P / B ratio is reduced,
Applied. Next, the tribo (Q / M) has a small developing nip.
Φ15 sleeve with poor developability can be made larger
Was. This is because when the P / B ratio is increased, the tribo (Q / M)
When the P / B ratio is reduced, tribo (Q / M)
Is used. Like this
The toner supply amount (M
/ S) x tribo (Q / M) x development nip
And as a result, the development characteristic V
The -D curve could be made substantially the same. this child
Enables control of image gradation and gradation stability
At the same time, the durability life can be shared,
Furthermore, by selecting such a material, the developing device
2 space saving has become possible. With the above-described configuration, a high
The development system is compatible with high-speed machines.
In a developing device having a plurality of developing sleeves, the current
Developing properties can be prevented from being different for each image sleeve,
Digital image of the year and image floor corresponding to graphic
It can meet the requirements for tonality and gradation stability.
In the developing device having a plurality of developing sleeves, which is the second object,
Therefore, the life of the developing sleeve can be shared,
Service can be saved by eliminating maintenance work for service personnel
Cost can be reduced and the concentration is stable at high concentration.
The developing device can be provided. Also, the third object, sleeve ghost,
High density and stable for high speed
And saves space.
A developing device could be provided. <Embodiment 3> Next, an embodiment of the present invention will be described.
State 3 will be described. This embodiment is characterized by a reuse image forming apparatus.
That is, the developing device according to the present invention is applied to the apparatus. The reuse system is basically not transferred but remains.
Cleaning is waste toner.
Tribo is extremely small compared to New toner
And the cohesion of waste toner increases,
The share of S-Bgap increases, and the amount of film shaving increases.
This is shown in the developing characteristics of the reuse system shown in FIG.
You. The density is lower than that of the new toner,
It can be seen that the image sleeve difference has increased. This implementation
The embodiment is implemented in view of these. In this embodiment, the image forming apparatus shown in FIG.
A-Si drum was used as the photosensitive drum 201 in the apparatus
The digital copying machine will be described. The process speed of the digital copying machine is 56
0 mm / s at 115 sheets / min.
The surface is uniformly charged to +500 V by the primary charger 203
You. Next, 600 nm with a semiconductor laser having a wavelength of 680 μm.
Exposure 212 by PWM at the dpi
1 to form an electrostatic latent image. Next, regular development is performed by the developing device 202.
The electrostatic latent image is visualized as a toner image. Magnetic as developer
Development using a one-component negative toner. Tona
The particle size is 6.0 μm; With conventional two-component developers,
Servicemen have to replace carriers every 100,000 copies
And the benefits of reuse are not
Cannot be reflected. On the other hand, durability can be ignored and no
A dry magnetic one-component toner requiring only maintenance was used. Present
The image bias is 2000 Hz, 1500 V for both the first and second.
pp, Duty 50% AC voltage + 200V DC voltage
Apply the folded bias voltage. S-Bgap is 25
0 μm and S-Dgap were 250 μm. Then pos
The total current of -200 μA in the charging device 210 to form a toner image
After charging, the toner image is transferred to the transfer material that moves in the direction of the arrow.
The toner image is transferred by the transfer charger 204.
The transfer material is sent to the fixing device 207 to fix the toner image. On the other hand, the transfer residual toner on the photosensitive drum 201
Is removed and collected by the cleaning device 206, and
The waste toner (reuse toner) is developed through
Return to upper 209B. There is no screw inside the transport pipe 208.
A transfer member in the form of a menu is provided.
By rotating, the reused toner is transported. Soshi
And the reused toner is collected in the developing hopper 209B.
And reused. The new toner is stored in the hopper 209A.
And the magnetic force of the magnet rollers 21A and 21B.
And the magnet rollers 21A, 21A
1B is conveyed to the developing device 202 by rotation.
You. In this embodiment, the reuse toner and the new toner
Was mixed in the developing device 202.
It is permissible to provide a mixing space inside the room. Thus, the toner mixed in the developing device 202
The toner is sent to the developing sleeve again, and
Is used for development of the electrostatic latent image formed on the substrate. Magnetro
The normal rotation speed of the roller 21A is 2 revolutions / minute,
The rotation speed of the net roller 21B is changed. Developing device
Self-weight of toner on piezo sensor (made by TDK) in 202
Is not applied, and when the piezo sensor vibrates, the toner
A supply signal is issued. Normally, the magnet roller 21B
Is 10/90 (magnet) with respect to the magnet roller 21A.
Roller 21A: magnet roller 21B = 9: 1)
To Configuration of developing device 202 according to the present embodiment
Is an epoxy resin and TiO, as in the second embodiment._Two ,
Diameter of sleeve is φ20mm and φ15 with membrane using carbon
mm. Table 9 shows the effects of the present embodiment. [0082] [Table 9]As shown in Table 9, the shaving amount at 500k sheets was φ20.
Φ15 sleeve compared to 6.0μm sleeve
Was almost the same as 6.2 μm. this isReuseso
Life is about 800k despite the aggregation of waste toner
Means Next, the tribo (Q / M) has a small developing nip.
Φ15 sleeve with poor developability can be made larger,
Despite the deteriorated toner, 7.5 and 8.5 were obtained. This
The toner which is an index of the development characteristics
Supply amount (M / S) x tribo (Q / M) x development nip value
Can be made almost equal, and as a result,
VD curve, which is the characteristic, can be made almost the same curve.
Was. This makes it possible to control image gradation and gradation stability.
Control, and a durable life
A lease system was realized. With the above configuration, the reuse compatible
Development system, and the first purpose
For each developing sleeve in a developing device having a developing sleeve
Can be prevented from differing in developability.
Gradation and gradation of images corresponding to images and graphics
The requirements of stability can be satisfied, and
Developing device having a plurality of developing sleeves.
The service life of the serviceman can be standardized.
Service costs by eliminating maintenance
Developing equipment with high density and stable density
Could be provided. In addition, the third object, which is to increase the speed
Is stable at high concentration, saving space and
It is possible to provide a developing device with excellent use and environment.
Was. [0086] As is apparent from the above description, the present invention
According to recent digital images and graphics
To meet the requirements of image gradation and gradation stability.
The effect that can be obtained is obtained. Also,Toner carrierCommon life
Saves maintenance work by service personnel
And service costs can be reduced
Is obtained. Further, generation of a sleeve ghost image is prevented.
At the same time, stabilize developability and density against high speed
The effect that it can be obtained is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a developing device according to the present invention. FIG. 2 is a perspective view of a developing sleeve of the developing device according to the present invention. FIG. 3 is a cross-sectional view of a main part of an image forming apparatus including a developing device according to the present invention. FIG. 4 is a sectional view showing a magnetic pole arrangement of a developing sleeve of the developing device according to the present invention. FIG. 5 is a diagram showing a developing bias waveform. FIG. 6 is a diagram illustrating development characteristics of a conventional developing device. FIG. 7 is a diagram illustrating development characteristics of a conventional development device. FIG. 8 is a diagram showing the relationship between the P / B ratio of the film composition and the amount of film shaving. FIG. 9 is a diagram showing the relationship between the P / B ratio of film composition and tribo (Q / M). FIG. 10 is a diagram illustrating development characteristics of a conventional reuse image forming apparatus. FIG. 11 is a sectional view of a main part of a reuse image forming apparatus including a developing device according to a third embodiment of the present invention. FIG. 12 is a diagram illustrating a relationship between an outer diameter of a sleeve and a size of a developing nip. FIG. 13 is a sectional view of a main part of an image forming apparatus including a conventional developing device. DESCRIPTION OF SYMBOLS 1 Photosensitive drum (electrostatic latent image carrier) 2 Developing device 3 Primary charger 4 Transfer charger 6 Cleaning device 7 Fixing device 10 Post charger 12 Image exposure 20 Developing sleeve (developer carrier) 30 Developing sleeve (developer carrier)

Claims (1)

(57) [Claims] 1. An electrostatic latent image carrier is juxtaposed along the rotation direction.
Carrying multiple toners with different outer diameters that are rotatable in the same direction
And a plurality of toners corresponding to the plurality of toner carriers.
A blade that regulates the layer thickness of the toner on the carrier, wherein each toner carrier comprises a non-magnetic member around a magnetic member inside and a coating member covering the non-magnetic member .
In the developing apparatus equal rotation speed of the toner carrying member, the weight of the resin before configuring the logger computing member B, the resin
Graphite and conductive carbon mixed with water
If the weight of titanium oxide and conductive carbon is P
Weight of the coating member of the toner carrier with a small outer diameter
Coating of toner carrier having a large outer diameter with a quantity ratio of P / B
A developing device wherein the weight ratio of the members is smaller than P / B.