JP2013200375A - Developing device and image forming apparatus - Google Patents

Abstract

In a flare (cloud) development method in which toner is hopped by an electric field, a developing device capable of suppressing toner scattering due to residual toner with high accuracy and preventing background contamination and environmental pollution is provided.
A developing device 16 agitates a flare roller 22 as a developer carrying member that conveys a developer to a photosensitive drum (not shown) and develops a latent image on the photosensitive drum in a development region, and an agitation paddle 18. A supply roller 21 that supplies the supplied developer to the flare roller 22 and collects development residual toner remaining after development. The seal member 26 is in contact with the vertical vertex position of the surface of the flare roller 22. On the upstream side of the seal member 26 in the rotation direction of the flare roller 22, there is provided a charge imparting member 27 that charges the undeveloped toner and increases the restraining force of the flare roller 22.
[Selection] Figure 3

Description

  The present invention relates to a developing device for visualizing an electrostatic latent image (hereinafter also simply referred to as “latent image”) formed on an image carrier based on image information, a copier having the developing device, a printer, a facsimile, The present invention relates to a plotter and an image forming apparatus such as a multifunction machine including at least one of them.

Conventionally, as a developing device of this type, toner adsorbed on a developing roller or a magnetic carrier is not used for development, but toner hopped on the surface of a toner carrier (developer carrier) such as a toner transport substrate is used. Those used for development are already known. Hereinafter, this method is referred to as “flare method” or “cloud method”.
For example, the developing device described in Patent Document 1 includes a cylindrical toner carrier including a plurality of electrodes arranged at a predetermined pitch in the circumferential direction. These electrodes are formed by repeatedly arranging electrode pairs composed of two adjacent electrodes. An alternating electric field is formed between the two electrodes in each electrode pair.
As a result, the toner located on one electrode in the electrode pair floats and landes on the other electrode, or floats on the other electrode and landes on the one electrode. . This behavior is called “hopping”.

While repeating hopping in this manner, the developer is transported to the development region by surface movement accompanying the rotational driving of the cylindrical toner carrier. In the developing area, the toner that has floated to the vicinity of the latent image on the image carrier is attracted to the electric field by the latent image and does not descend toward the electrode of the toner carrier, and adheres to the latent image.
In such a configuration, not the toner adsorbed on the developing roller or the magnetic carrier but the toner that does not exhibit the adsorbing force by hopping is used for the development. As a result, it is possible to realize low-potential development that cannot be realized by the conventional one-component development method or two-component development method.
For example, toner can be selectively attached to an electrostatic latent image having a potential difference of only a few tens [V] with respect to surrounding non-image portions.

FIG. 10 shows a conventional flare type developing device. Reference numeral 9 denotes a photosensitive drum as an image carrier, 22 denotes a flare roller as a developer carrier, 21 denotes a supply / recovery roller as a developer supply member, and 23 denotes a developer layer thickness on the flare roller 22. 3 shows a toner layer thickness regulating member that regulates
A portion of the developing device facing the image carrier of the flare roller 22 is opened as a developing region.
As shown in FIG. 11, the seal member 26 is provided on the downstream side in the flare roller rotation direction at the facing portion so that the free end thereof is in contact with the flare roller surface and along the flare roller rotation direction, The developer in the developing device is prevented from leaking out of the device through the facing area. The seal member 26 is also called “development seal member” or “entrance seal”. In FIG. 10, the seal member 26 is omitted.
As a material of the seal member 26, for example, a PET film (Mylar (registered trademark)) is employed.

However, in the flare type developing device described in Patent Document 1 and the like, the adhesion force between the toner carrier and the toner is extremely small, and the development residual toner remaining on the flare roller 22 after development is stored in the toner container in the developing device. When entering, there is a problem that the toner leaks out of the apparatus without being taken into the developing device (toner scattering) without being taken into the developing device because it is repelled by being brought into contact with the seal member 26 or rebounded by the seal member 26.
When the toner scatters, the scattered toner adheres to the non-image portion of the image carrier and causes scumming (deterioration in image quality), or contamination in the image forming apparatus (especially adverse effects on the optical system).

  SUMMARY OF THE INVENTION The present invention has been made in view of such a situation, and it is a main object of the present invention to provide a developing device capable of suppressing toner scattering due to undeveloped residual toner with high accuracy and preventing ground contamination and contamination in an image forming apparatus. And

  In order to achieve the above object, the present invention comprises a developer carrying member that conveys a developer to an image carrying member, and a developer supply member that supplies the developer to the developer carrying member, The agent carrier includes a first electrode and a second electrode provided via an insulator with respect to the first electrode, and the potential difference between the first electrode and the second electrode is temporally The developer on the developer carrier is clouded by applying a reversal voltage, and the developer carrier is moved to the development area by moving the surface of the developer carrier to be formed on the image carrier. In a developing device that develops an electrostatic latent image and collects the developer remaining on the developer carrying member after development by the developer supply member, the developer remaining after the development is collected by the developer supply member After the development, on the upstream side of the rotation direction of the developer carrier relative to the position Providing the charge-providing means for applying a charge to the developer remaining, characterized in that said.

  According to the present invention, the developer remaining after development can be transported into the apparatus while being held (restrained) on the surface of the developer carrying member by charging by the charge imparting member. It is possible to suppress soil contamination and environmental pollution around the device.

1 is a schematic configuration diagram of an image forming apparatus according to a first embodiment of the present invention. It is a figure which shows the detail of a structure of the imaging device of each color. It is a schematic sectional drawing of a developing device. It is an experimental characteristic figure which shows the effect of this embodiment. It is a schematic sectional drawing of the image development apparatus in 2nd Embodiment. It is a perspective view of a flare roller. It is a cross-sectional development view of the circumferential direction of the electrode part of a flare roller. It is a plane development view of the electrode part of a flare roller. It is a figure which shows the drive waveform applied to an electrode. FIG. 6 is a schematic sectional view of a conventional flare type developing device. It is a principal part enlarged view which shows the arrangement configuration of the sealing member in the conventional flare-type developing device.

Embodiments of the present invention will be described below with reference to the drawings.
The first embodiment will be described with reference to FIGS. First, an outline of the configuration of an image forming apparatus capable of full color image formation according to the present embodiment will be described with reference to FIG.
As shown in FIG. 1, the image forming apparatus according to the present embodiment includes image forming apparatuses 15Y (yellow), 15M (magenta), 15C (cyan), and 15K (for four colors as image carrier units or process units. The image forming device 15 serving as each station is detachably attached to the device main body 80.
In addition to each image forming device 15, an optical scanning device 20 as an exposure unit capable of irradiating a laser beam, an intermediate transfer body unit 30, a paper feed unit 60, a fixing unit 50 as a fixing unit, and the like are provided.

The structures of the image forming devices 15Y, 15C, 15M, and 15K are the same except that the development colors are different. The yellow image forming device 15Y will be described as a representative. The photosensitive drum 9Y as an image carrier, the charging device 13Y for charging the photosensitive drum, and the cleaning device for removing the developer remaining on the photosensitive drum. 14Y and a developing device 16Y that develops the latent image formed on the photosensitive drum are integrally provided.
Each image forming apparatus is configured to be detachable from the apparatus main body in the opening / closing direction of an openable / closable face plate (not shown) provided on the operation surface side of the apparatus main body, that is, the rotation axis direction of the photosensitive drum.

The intermediate transfer body unit 30 includes an endless transfer belt 31 as an intermediate transfer body and four primary transfer rollers 35 as primary transfer means for transferring the toner images formed on the respective photosensitive drums 9 to the transfer belt 31. And a secondary transfer roller 36 as secondary transfer means for transferring the toner image transferred onto the transfer belt 31 onto a recording paper P as a recording medium.
The transfer belt 31 is wound around the support rollers 32 and 33 and the primary transfer roller 35, and the support roller 32 faces the secondary transfer roller 36 with the transfer belt 31 interposed therebetween, and is between the secondary transfer roller 36. The secondary transfer nip portion is formed by the above.
A belt cleaning device 38 for cleaning the surface of the transfer belt 31 after transfer is provided at a portion facing the support roller 33.

The paper feed unit 60 has a configuration in which a bundle of recording paper P is brought into contact with the calling roller 61 by operating an arm 48 installed inside the paper feed cassette 41 by a lift motor (not shown) to raise the tray bottom plate 47. Have.
By rotating the calling roller 61, the bundle of recording papers P is shifted downstream in the paper feeding direction, and one sheet of the uppermost paper is separated by the paper feeding roller 62 and the reverse roller 63, and the conveying roller pair 64 and the registration roller pair 65 are separated. Transport to secondary transfer area.
The fixing unit 50 includes a fixing roller 51 and a pressure roller 52, and performs fixing by applying heat and pressure to the toner image on the recording paper P.

In the above configuration, first, in the yellow image forming device 15Y for the first color, the photosensitive drum 9 is uniformly charged by the charging device 13, and then the laser beam (modulated with yellow image data) emitted from the optical scanning device 20 is used. Electrostatic latent image is formed by the developed light beam, and the latent image is visualized as a toner image by the developing device 16.
The toner image formed on the photosensitive drum 9 is transferred onto the transfer belt 31 by the action of the primary transfer roller 35. After completion of the primary transfer, the photosensitive drum 12 is cleaned by the cleaning device 14 to prepare for the next image formation.
The residual toner collected by the cleaning device 14 is stored in a waste toner collection bottle (not shown) installed in the take-out direction of the image forming device. The waste toner collection bottle is detachable from the apparatus main body so that it can be replaced when it is full.

A similar image forming process is also performed in the image forming apparatuses 15M, 15C, and 15K to form toner images of the respective colors, which are sequentially superimposed on the previously formed toner images and transferred as full-color images.
On the other hand, the recording paper P is conveyed from the paper feed cassette 41 to the secondary transfer region, and the toner image formed on the transfer belt 31 is secondarily transferred to the recording paper P by the secondary transfer roller 36 to which a transfer bias is applied. The
The recording paper P to which the toner image has been transferred is conveyed to the fixing unit 50, where the toner image is fixed at the nip portion between the fixing roller 51 and the pressure roller 52 of the fixing unit 50, and discharged by the discharge roller pair 55. The paper is discharged to the tray 56.
The recording paper P is also set on the manual feed tray 59, and is similarly fed and transported by the paper feed roller 58, transferred and fixed, and discharged to the paper discharge tray 56.
The toner of each image forming device 15Y, 15M, 15C, 15K is consumed by the image formation. In response to this, new toner is supplied from the toner bottles 57Y, 57M, 57C, and 57K. At the time of toner supply, the toner bottles 57Y, 57M, 57C, and 57K are rotated, and the toner is conveyed to each image forming device through a pipe (not shown).

  FIG. 2 is a detailed view of each image forming apparatus. The developing device 16 is integrated with the photosensitive drum 9 and the like as one component of the image forming device (process unit) 15.

Based on FIG. 3, the configuration of the developing device 16 according to the present embodiment and the toner behavior in the developing device will be described.
First, toner (nonmagnetic one-component developer) as a developer accommodated in the toner accommodating portion 17a of the casing 17 is conveyed to a supply roller 21 as a developer supply member by a stirring paddle 18 as a stirring member. . In the present embodiment, the supply roller 21 also functions as a collection roller by rotating the supply roller 21 in a counter direction with a flare roller 22 as a developer carrier. Of course, the supply member and the recovery member may be independent.
When toner is supplied from the supply roller 21 to the flare roller 22, the toner is charged by friction between the flare roller and the supply roller. The charged toner performs a hopping motion (described later) according to an electric field that periodically changes between the two-phase electrodes inside the flare roller.
Then, after the flare roller itself rotates and passes through the toner layer thickness regulating member 23 and the amount of adhesion is regulated, the flare roller is conveyed to a region (development region) facing the photosensitive drum 9 to be electrostatically charged on the photosensitive drum. Develop the latent image without contact.

On the other hand, the toner that has not contributed to development passes through the development area. The toner after passing is collected by the supply roller 21 that also functions as a collection roller, and is temporarily returned to the toner storage portion 17a. Since the toner on the flare roller is hopped, the adhesion force between the flare roller and the toner is small and is easily collected by the collection roller.
By repeating the above-described series of processes, a state where toner is always hopping is formed on the flare roller.
One end of the sealing member 26 is fixed to the element 25 constituting the casing 17, and the free end is in contact with the surface of the flare roller 22 so as to follow the rotation direction of the flare roller 22.

As described above, when the seal member 26 comes into contact with the flare roller 22 downstream of the facing region, the toner hopping on the flare roller is repelled by the seal member 26 and passes because the adhesion force with the flare roller is small. The inability to do so is a problem.
In the present embodiment, in order to solve this problem, a roller-shaped roller serving as a charge applying unit for applying charge to the development residual toner is provided upstream of the position where the development residual toner is collected by the supply roller 21 in the rotation direction of the flare roller 22. A charge imparting member 27 is provided.
A voltage applying means (not shown) is connected to the charge applying member 27. By applying a charge to the undeveloped toner by the charge applying member 27 and increasing the charge amount so that the restraining force by the flare roller 22 is increased, toner scattering can be suppressed.

In this embodiment, a rectangular wave as shown in FIG. 11B is used as a bias applied to the two-phase electrodes inside the flare roller. That is, the two-phase electrodes were each a rectangular wave bias having an offset voltage V0 of −300V, a frequency f of 700 Hz, and a peak-to-peak voltage Vpp of 500V.
The charging member 27 is a roller made of rubber, and is installed with a 1 mm gap from the flare roller. The charging member 27 is rotated by a rotation mechanism (not shown). The rotation was driven at a rotation speed at which the speeds of the flare roller surface and the surface of the charging member 27 were equal.
The effect was verified by applying an AC voltage to the charging member 27. As for the applied bias, the Q / M (charge amount) and scattering amount of the developed toner were measured while changing the offset value with a sine wave of -2 kVpp and 1 kHz.

FIG. 4 shows the verification result. The amount of toner scattering on the vertical axis was measured by covering the developing device with paper and the amount of toner adhering to the paper. As can be seen from the figure, as the toner Q / M after development increases, the amount of toner scattering decreases.
This is because as the Q / M increases, the charge amount of each toner increases, and the binding force due to the electric field applied to the flare roller increases. In addition, when Q / M is -50uC / g or more, the charge of each toner is very high, and the electrostatic adhesion between the flare roller and the toner becomes high, so it is impossible to hop. As a result, since the toner enters the seal portion in a state of being in close contact with the flare roller (in a state where the restraining force is increased to the limit), the amount of scattered toner is reduced.

In the figure, the amount of scattering shown by the dotted line is the result of measurement with a commercially available developing device (method that uses toner adsorbed on a developing roller or magnetic carrier for development). By increasing the offset value, the flare method It was confirmed that it can be improved to the same level as the market.
In the present embodiment, the roller-shaped charge imparting member 27 is configured to rotate, but the charge imparting function can also be obtained as a fixed method. In the case of the rotation method, the discharge surface of the charging member 27 facing the flare roller 22 can be always cleared, and the charging function can be maintained uniformly.
Although not shown, the charging member is not limited to a roller shape, and the same effect can be obtained even in a wire shape.

In the developing device shown in FIG. 3, the seal member 26 made of Mylar (registered trademark) as a development upper seal member is installed so as to come into contact at the apex position in the vertical direction of the flare roller. In view of the above, it is desirable to have a layout in which the bounced back enters the seal portion again.
That is, it is desirable that the flare roller 22 is provided so as to be in contact with the highest position in the vertical direction (the position shown in FIG. 3) on the surface of the flare roller 22 at a position downstream of the flare roller 22 in the rotational direction and at a lower position. .

A second embodiment will be described with reference to FIG. In addition, the same part as the said embodiment is shown with the same code | symbol, and unless it was especially required, the description on the structure and function which were already demonstrated is abbreviate | omitted, and only the principal part is demonstrated.
In the present embodiment, an inlet member 29 is provided through a gap between the surface of the flare roller 22 and a portion where the development residual toner enters the apparatus. As a result, a conveyance path 25 is formed between the flare roller 22 and the inlet member 29 to guide the undeveloped toner into the apparatus.
The conveyance path 25 has an arcuate cross-sectional shape along the surface of the flare roller 22, and should be referred to as a non-contact opening with respect to the flare roller 22.
The entrance member 29 is provided with a roller-shaped charging member 27 so as to face the transport path 25. The charging member 27 may be provided so as to rotate as described above, or may have a wire shape.
In the present embodiment, the undeveloped toner can be taken into the apparatus by the drawing air flow accompanying the rotation of the flare roller 22 by the conveyance path 25 which is a closed space, and the restraining force by the charging member 27 can be obtained. As a result, the sealing member 26 is not provided.

The undeveloped toner is carried to the toner accommodating portion by the drawing airflow caused by the rotation of the flare roller 22, but in the configuration in which only the conveying path 25 is provided, a discharge airflow is generated due to an increase in the internal pressure on the toner accommodating portion side. Similar to the contact configuration by the sealing member 26 shown, the toner is repelled and scattering occurs.
By providing the charge imparting member 27, toner scattering can be suppressed even in the configuration having the transport path 25.

Table 1 shows a condition in which the seal member 26 abuts on the roller at the vertical apex of the flare roller 22 (FIG. 3), and a condition in which the abutment position of the seal member is a low position downstream in the rotation direction of the flare roller 22 ( The measurement result of the toner scattering amount with and without the charge imparting member is shown for each of the conditions (FIG. 5) including the conveyance path 25 as a non-contact opening.
It was confirmed that the effect of the charge imparting member appeared in any form, and the amount of scattering was further reduced by the combination with the conveyance path (non-contact opening).
Under the condition that the contact position of the seal member is set to a low position on the downstream side in the rotation direction of the flare roller 22, when the charging member is provided, the result is the same as the case of sealing at the apex position, but the low value on the downstream side. Since the seal configuration at the position itself has the effect of suppressing scattering when there is no charge imparting member, from the viewpoint of reliably suppressing toner scattering, the re-entry function by gravity can be obtained for the seal position. A combination of a “seal configuration at a low position” and a charging member is desirable.

The flare development will be described below.
A schematic view of the flare roller 22 is shown in FIG. FIG. 7 is a schematic view of a circumferential section of the electrode portion of the flare roller.
Electrodes are arranged on the support substrate at predetermined intervals, and a surface protective layer made of an inorganic or organic insulating material is laminated thereon. In addition, the line extended from each electrode in FIG. 7 represents the conductive wire for applying a voltage to each electrode, and only the part shown by the black circle among the overlapping parts of each line is electrically connected, The part is electrically insulated.
Two-phase different drive voltages are applied to each electrode from the power source on the main body side.

FIG. 8 is a plan development view of the flare roller electrode portion. As can be seen from these figures, the flare roller has a two-phase electrode group that generates an electric field for hopping the toner, and an example is shown in each of the even-numbered electrode group and the odd-numbered electrode group from drive circuits (not shown). As shown in FIG. 9 (a) or (b), an antiphase driving waveform is applied, and a time-periodic potential difference is formed between the two-phase electrodes.
The flare roller is rotationally driven, and an odd numbered electrode is connected to one of the rotating shafts, and an even numbered electrode is connected to the other of the rotating shafts.

As the support substrate of the flare roller, an insulating material such as a resin, or a substrate made of a conductive material such as SUS and an insulating film such as SiO ₂ may be applied.
The electrode is formed on a support substrate with a conductive material such as Al, Cu, Ni-Cr, etc. in a thickness of 0.1 to 10 um, preferably 0.5 to 2.0 um, and this is patterned into the required electrode shape using photolithography technology or the like. Formed.

Next, the electrode width L and electrode interval R on the flare roller for toner hopping, the drive waveform shape, and the surface protective layer will be described.
The electrode width L and the electrode interval R in the conveying member greatly affect the toner hopping efficiency. The electrode pitch P is expressed by P = R + L.
The toner between the electrodes moves to the adjacent electrode on the substrate surface by a substantially horizontal electric field. On the other hand, since the toner on the electrode is given an initial velocity having at least a component in the vertical direction, most of the toner flies away from the substrate surface.
In particular, since the toner near the electrode end surface moves over the adjacent electrode, when the electrode width L is wide, the number of toners on the electrode increases, and the toner having a large moving distance increases.

However, if the electrode width L is too wide, the electric field strength in the vicinity of the center of the electrode is lowered, so that the toner adheres to the electrode and the hopping efficiency is lowered.
Therefore, as a result of intensive studies, the present inventors have found that there is an appropriate electrode width for efficiently hopping toner at a low voltage.
In addition, the electrode interval R determines the electric field strength between the electrodes from the relationship between the distance and the applied voltage. The smaller the interval R, the stronger the electric field strength, and the easier the initial hopping speed is obtained. However, toner that moves from electrode to electrode has a short moving distance, and unless the drive frequency is increased, the hopping time is shortened and the landing time is lengthened. As a result of intensive studies, the present inventors have found that there is an appropriate electrode interval for efficiently transporting and hopping toner at a low voltage.
Further, the present inventors have also found that the thickness of the surface protective layer covering the electrode surface also affects the electric field strength on the electrode surface, in particular, the influence of the vertical component on the electric field lines is large, and determines the hopping efficiency.

That is, by appropriately setting the relationship between the electrode width of the flare roller, the electrode interval, and the surface protective layer thickness, efficient hopping can be performed at a low voltage.
Therefore, in each of the above embodiments, the electrode width L shown in FIG. 7 is 1 to 20 times the average toner particle size, and the electrode interval R is also 1 to 20 times the average toner particle size.
Next, for example, SiO ₂ , BaTiO ₂ , TiO ₂ , TiO ₄ , SiON, BN, TiN, Ta ₂ O ₅ or the like can be applied to the surface protective layer, and the thickness is formed to be 0.5 to 30 μm.
Further, an organic material such as polycarbonate may be coated on SiO ₂ or the like. It is also possible to select zirconia or a material generally used as a coating material for a carrier of a two-component developer, for example, a silicone resin. The surface protective layer is appropriately selected from the relationship between the insulating property, durability, the production method of the flare roller itself, and the charge train with the toner to be used.

When the developing device according to the present invention is used in an image forming apparatus, it is necessary to use a fine pattern as a flare roller that is at least as long as A4 21 cm wide or 30 cm wide and has a large area.
Here are some examples of how to make flare rollers.
First, a case where a flexible electrode pattern is formed and wound around a support drum to form a flare roller will be described.
As an example of a substrate having a flexible fine pitch thin layer electrode, a polyimide base film (thickness 20 to 100 μm) is used as a base material (supporting substrate), and 0.1 to 0.3 μm of Cu, Al, Ni-Cr or the like is deposited. If it is 30-60 cm in width, it can be manufactured by a roll-to-roll apparatus, and mass productivity is greatly enhanced. The common bus line simultaneously forms an electrode having a width of about 1 to 5 mm.

  As a specific means of the vapor deposition method, a sputtering method, an ion plating method, a CVD method, an ion beam method, or the like can be used. For example, when an electrode is formed by sputtering, a Cr film may be interposed in order to improve the adhesion with polyimide, and the adhesion can also be improved by plasma treatment or primer treatment.

As a method other than the vapor deposition method, the thin layer electrode can be formed also by an electrodeposition method. In this case, an electrode is first formed on the polyimide substrate by electroless plating. After the base electrode is formed by sequentially immersing in Sn chloride, Pd chloride, and Ni chloride, the Ni film of 1 to 3 um can be manufactured roll-to-roll by electrolytic plating in a Ni electrolyte solution.
Electrodes 12 are formed on these thin film electrodes by resist coating, patterning, and etching. In this case, if it is a thin layer electrode having a thickness of 0.1 to 3 μm, a fine pattern electrode having a width of 5 μm to several tens of μm or an interval can be accurately formed by photolithography and etching.

Next, SiO ₂ , BaTiO ₂ , TiO ₂ or the like is formed as the surface protective layer 13 to a thickness of 0.5 to ₂ μm by sputtering or the like. Alternatively, PI (polyimide) as a surface protective layer is applied to a thickness of 2 to 5 μm with a roll coater or other coating apparatus, and baked to finish. When trouble occurs with PI, it is sufficient to form SiO _{2 on} the outermost surface and other inorganic film to a thickness of 0.1 to 0.5 μm by sputtering or the like. Further, an organic material such as polycarbonate may be coated on SiO ₂ or the like. It is also possible to select zirconia or a material generally used as a coating material for a carrier of a two-component developer, for example, a silicone resin.

By configuring such a flexible substrate, it can be easily attached to a cylindrical drum, or partially curved.
As another example, it is also possible to use 10 to 20um thick Cu, SUS, etc. as a base material (supporting substrate) with a polyimide base film (thickness 20 to 100um) as an electrode material. is there. In this case, conversely, polyimide is applied on a metal material by a roll coater and baked by 20 to 100 μm. After that, the metal material is patterned into the shape of an electrode by photolithography and etching, polyimide is coated on the electrode surface as a protective layer 13, and if there are irregularities according to the thickness of the metal material electrode 10-20um, it is flattened Complete.

For example, when a polyimide material or polyurethane material having a viscosity of 50 to 10,000 cps, more preferably 100 to 300 cps, is spin-coated and left standing, the unevenness of the substrate is smoothed by the surface tension of the material, and the outermost surface of the conveying member is flat. It becomes.
As yet another example of increasing the strength of the flexible substrate, a 20-30 um thick SUS or Al base material is used as the base material, and an insulating layer (insulation between the electrode and the base material) is formed on the surface. The diluted polyimide material of about 5um is coated with a roll coater. Then, this polyimide is pre-baked, for example, at 150 ° C. for 30 minutes, and post-baked at 350 ° C. for 60 minutes to form a thin-layer polyimide film to be a support substrate.

Then, after performing plasma treatment and primer treatment for improving adhesion, Ni-Cr is deposited as a thin electrode layer to a thickness of 0.1 to 0.2 um, and the fine pattern electrode 12 of several tens um is formed by photolithography and etching. To do. Furthermore, a flexible transport member can be obtained by forming a surface protective layer of SiO ₂ , BaTiO ₂ , TiO ₂ or the like on the surface to a thickness of about 0.5 to 1 μm by sputtering.
Further, an organic material such as polycarbonate may be coated on SiO ₂ or the like. It is also possible to select zirconia or a material generally used as a coating material for a carrier of a two-component developer, for example, a silicone resin.
Other flare roller manufacturing methods include screen printing using conductive ink, ink-jet printing, and other methods such as removing non-electrode parts of the plated electrode by laser processing. The creation method is not limited to the above-described method.

DESCRIPTION OF SYMBOLS 9 Photosensitive drum as image carrier 16 Developing apparatus 21 Supply roller as developer supply member 22 Flare roller as developer carrier 25 Conveyance path 26 Seal member 27 Charge application member 29 as charge application means 29 Entrance member

JP-A-3-21967

Claims (7)

A developer carrier for conveying the developer to the image carrier;
A developer supply member for supplying a developer to the developer carrier;
Have
The developer carrier includes a first electrode and a second electrode provided via an insulator with respect to the first electrode,
The developer on the developer carrier is clouded by applying a voltage at which the potential difference between the first electrode and the second electrode is reversed in time, and the developer is developed by moving the surface of the developer carrier. In a developing device for transporting a developer to a development region to develop an electrostatic latent image formed on the image carrier and collecting the developer remaining on the developer carrier after development by the developer supply member ,
A charge imparting means for imparting a charge to the developer remaining after the development is provided on the upstream side in the rotation direction of the developer carrier from the position where the developer remaining after the development is collected by the developer supply member. A developing device. The developing device according to claim 1,
2. A developing apparatus according to claim 1, wherein said charging means is constituted by a roller-like member disposed with a gap between said developer-carrying member and said developer-carrying member. The developing device according to claim 2,
A developing device in which the roller-like member rotates. The developing device according to claim 1,
2. A developing apparatus according to claim 1, wherein said charging means is a wire disposed in a gap with said developer carrying member and extending in the axial direction of said developer carrying member. In the developing device according to any one of claims 1 to 4,
A seal member that shields the inside and outside of the apparatus when the developer remaining after the development enters the apparatus;
The seal member is provided at a position downstream and lower in the rotation direction of the developer carrier than the highest position in the vertical direction of the surface of the developer carrier. Developing device. In the developing device according to any one of claims 1 to 4,
An inlet member is provided through a gap between the surface of the developer carrier at a portion where the developer remaining after the development enters the apparatus, and between the developer carrier and the inlet member, A developing device characterized in that a conveying path for guiding the developer remaining after the development into the device is formed. In an image forming apparatus that visualizes an electrostatic latent image formed on an image carrier based on image information as a toner image by a developing device, and finally transfers the toner image to a recording material to form an image.
7. The image forming apparatus according to claim 1, wherein the developing device is one according to any one of claims 1 to 6.

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