JPH08137251A - Developer regulating member, developing device using the same, image forming device and process cartridge using the same - Google Patents

Abstract

PURPOSE: To provide a developer regulating member capable of reducing electrostatic capacity and making the easiness of assembly and attachment compatible with the reduction of cost without spoiling the usual effect of blade bias by surely making a developing blade abut on a developing sleeve at the position of an electrode though the width of the electrode is made small. CONSTITUTION: The blade base substance 1b of the developing blade 1 is an elastic body such as urethane, silicone, chloroprene or fluororesin and the blade 1 is provided with a high resistance layer 1c consisting of urethane, silicone or nylon on the abutting surface side of the blade 1 with the developing sleeve 2. An electrode member 1a is disposed inside the high resistance layer 1c and abuts on the developing sleeve 2 through the high resistance layer 1c. The electrode member 1a and the high resistance layer 1c are formed to be projected with reference to the blade base substance 1b and the projected part abuts on the surface of the developing sleeve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic apparatus, a developing apparatus used therein, and a developer regulating member used therein.

[0002]

2. Description of the Related Art FIG. 14 is a diagram showing an example of a conventional image forming apparatus. In the figure, 101 is the main body of the image forming apparatus. Reference numeral 111 denotes a cylindrical photosensitive drum that is a latent image carrier, and rotates in one direction around its axis. The surface of the photosensitive drum 111 is uniformly charged by the charging device 103, and then a latent image is formed by the exposure device 102. Also,
The developing device is a hopper 1 for storing and storing the developer 109.
04 and a developing sleeve 105 serving as a developer carrier, the developer 10 is applied to the latent image formed on the photosensitive drum 111.
9 is supplied for visualization. The developing sleeve 10
A developing blade 107, which is a developer regulating member, is installed in the vicinity of 5. A bias power supply (not shown) in which an AC bias is superimposed on a DC bias is connected between the photosensitive drum 111 and the developing sleeve 105,
It is designed to give a proper developing bias.

The image on the photosensitive drum 111 thus visualized by the developer 109 is transferred onto the transfer material 114 by the transfer device 110. The transfer material 114 is the paper feed roller 11
The sheet is fed at 6, and is sent to the transfer device 110 in synchronization with an image on the photosensitive drum 111 by a registration roller (not shown). Then, the visible image formed by the developer transferred to the transfer material 114 is conveyed to the fixing device 115 together with the transfer material 114 and fixed by heat or pressure to form a recorded image. On the other hand, the developer remaining on the photosensitive drum 111 after being transferred is removed by a cleaning device 112 having a blade 113. After that, the surface of the photosensitive drum is charged again by the charging device 103 and the above steps are repeated.

Various types of developing devices can be applied to the image forming apparatus as described above, and for example, there is one using a magnetic one-component developer as shown in FIG. FIG.
Numeral 105b is a non-magnetic developing sleeve as a developer carrying member formed of an aluminum or stainless steel pipe, in which a magnet 105a in which a plurality of magnetic N and S are alternately formed is provided on the developing sleeve 105b. It is arranged immovably.

At a position on the developing sleeve 105b, a developing blade 107a made of rubber (eg, urethane rubber, silicone rubber, etc.) or a metal plate spring is fixed to the support plate 107b as a developer regulating member. Sleeve 10
5b is contacted with a predetermined pressure. The toner 109, which is the developer attracted to the developing sleeve 105b by the magnetic force, is regulated by the developing blade 107a in an appropriate amount, and is rubbed between the developing sleeve 105b and the developing blade 107a to be frictionally charged to give an appropriate charge. Then, it is transported to the developing area. However, the toner 109 strongly charged by the above-mentioned triboelectrification causes the developing sleeve 105
When it comes close to b or the developing blade 107a, a large electrostatic mirroring force works between them and adheres to their surfaces.
Further, the toner 109 attached to the surfaces of the developing sleeve 105b and the developing blade 107a is subjected to various physical attraction forces in addition to the electrostatic mirror image force, so that it cannot be easily peeled off from the surface. For this reason, as shown in FIG.
5b and the surface of the developing blade 107a have several layers of toner 10
9 is attracted, and the toner supplied to the developing sleeve 105b later is the developing sleeve 105b and the developing blade 107a.
It prevented me from coming into contact with.

When an image having a low printing rate is continuously developed especially in a low humidity environment, the toner covering the developing sleeve 105b is further strongly charged, and uneven charging of the toner and uneven coating occur. There was a case where a corresponding uneven image defect occurred.

Further, in the above-mentioned state, not only the charging efficiency of the toner is lowered, but also the frictional electrification between the toners is increased, so that the amount of the toner charged to the opposite polarity (reversed toner) is relatively increased. This results in a decrease in image density and an increase in "fog" in the non-image area, resulting in a loss of image quality.

Further, the toner 10 on the developing sleeve 105b
When only a part of 9 is subjected to development, the development sleeve 105
There is a difference in the amount of charge between the toner newly carried and charged in the portion used for the development of b and the toner which is not used for the development and is further charged, and the charge of the toner is charged. Due to the difference in amount, a phenomenon (a phenomenon called "ghost") in which the influence of the previous image appears when the image is developed next time may occur.

In addition, when foreign matter is caught between the developing sleeve 105b and the elastic blade 107a, the application of the toner 109 may be disturbed. In the past, the application of the toner was effectively alleviated. There was no way to do it.

Therefore, as a measure against these problems, a method has been proposed in which an electrode is provided on the elastic blade 107a and a bias voltage is applied to the electrode. Hereinafter, this method is referred to as a blade bias method.

A developing device adopting this system will be described in more detail with reference to FIGS. 16, 17, 18, and 19.

In the developing device of FIG. 16, the developing blade main body 118b is made of an insulating material such as urethane, and the surface of which is provided with an electrode 118a made of a conductive material such as carbon-dispersed nylon. The entire surface of the developing blade, or at least the surface on the developing sleeve 105b side is covered with a high resistance layer 118c such as urethane resin. The elastic blade 118b is attached to the developing sleeve 105b,
The contact is made in the opposite direction to the rotation direction. Then, via a sliding contact (not shown) to the developing sleeve 105b,
A developing bias is applied by the power supply 119. A bias power supply 120 for applying a blade is connected to the electrode 118a so that a predetermined bias voltage can be applied. The high resistance layer 118c of the developing blade 118b is
It is provided to prevent leakage between the electrode 118a and the developing sleeve 105b.

As described above, the developing blade 118 has a power source 120 between the electrode 118a and the developing sleeve 105b.
An alternating electric field is applied by the blade bias from the above, and a force corresponding to the strength of the alternating electric field acts on the charged toner in the meantime. 18 and 19 when this force exceeds the electrostatic mirror image force acting between the strongly charged toner and the developing blade 118 or the developing sleeve 105b.
The toner moves as shown in FIG. For example, when the alternating electric field E is in the direction from the developing sleeve 105b to the developing blade 118 as shown in FIG. 19, the toner layer covering the developing blade 118 is peeled off, and the toner layer is transferred and removed as the developing sleeve 105b rotates. . Therefore, this toner layer is peeled off, and is transferred and removed as the developing sleeve 105b rotates. Therefore, the adverse effects of the contact inhibition of the new toner with the developing sleeve 105b and the developing blade 118 and the frictional electrification between the toners caused by the toner layer are eliminated, the charging efficiency of the toner is improved, and the reversal toner is reduced.

In particular, the developing blade 118 and the developing sleeve 1
On the downstream side from the rubbing portion of 05b, as shown in FIG.
The toner reciprocates according to the alternating electric field. In this downstream region, the developing blade 118 or the developing sleeve 105
Not only is the toner layer covering the surface b peeled off, but also because the toner reciprocates, the excessively charged toner layer and the toner chain formed by the magnetic force are loosened and sufficiently stirred. Due to this stirring effect, the uneven charging of the toner is almost eliminated. In addition, uneven coating caused by foreign matter sandwiched between the developing blade 118 and the developing sleeve 105b is also alleviated by the above stirring effect.

As a matter of course, if the alternating electric field is constantly applied during the rotation of the developing sleeve 105b, the toner layer covering the developing blade 118 or the developing sleeve 105b is not formed, and the above-mentioned problem occurs. Absent.

With the above-mentioned structure, the charge amount of the toner can be set to a predetermined value, and a high-quality image free from sleeve ghost, reversal fog, and density unevenness can be stably obtained. It has become possible.

[0017]

However, when the width of the electrode 118a is large, the electrostatic capacitance between the electrode 118a and the developing sleeve 105b becomes large. Therefore, when the alternating electric field is applied, Since a large amount of current flows, power consumption increases, and with it,
The power supply 120 also needs to have a larger capacity, which has been a factor of increasing the product cost.

Therefore, an attempt has been made to reduce the width of the electrode 118a in order to reduce the product cost due to the reduction in power source capacity. However, as the width becomes smaller, the developing sleeve 1
Electrode 1 for the contact position between 05b and the developing blade 118
It becomes difficult to position 18a (position of the electrode on the blade, and position of the electrode so as to match the contact position with the developing sleeve in both the longitudinal direction and the longitudinal direction), and conversely, the manufacturing cost is reduced. This has resulted in an increase.

An object of the first invention of the present application is to solve the above-mentioned problems and reduce the width of the electrode, and surely bring the developing blade into contact with the developing sleeve at the electrode position, so that the blade bias of the prior art is reduced. Another object of the present invention is to provide a developer regulating member that reduces electrostatic capacitance without sacrificing the further effect, and that facilitates assembly and attachment and reduces cost.

A second object of the present invention is to provide a developer regulating member capable of further stabilizing the contact of the blade and stabilizing the control of the toner coating amount. .

An object of a third invention according to the present application is to solve the above-mentioned problems and to maintain the electrostatic capacity while maintaining a sufficient effective contact width with the developing sleeve without impairing the effect of the blade bias from the conventional one. It is an object of the present invention to provide a developer regulating member that can be reduced in number and can be positioned easily and can be reduced in cost.

An object of a fourth invention according to the present application is to provide a developer regulating member capable of further reducing electrostatic capacitance, realizing easier positioning and cost reduction than the third invention. To do.

The fifth object of the present invention is, in addition to the above-mentioned fourth object, a developer regulating member which does not reduce the blade bias effect even if a part of the electrode in the developing blade is damaged. To provide.

A sixth object of the present invention is to provide a developing device using the developer regulating member, which can obtain a high quality image at a low cost.

A seventh object of the present invention is to provide an image forming apparatus using the developing device, which can obtain a high quality image at a low cost.

An eighth object of the present invention is to provide a process cartridge which uses the developing device and can obtain a high quality image at a low cost.

[0027]

According to the first invention of the present application, the above-mentioned object is to bring the developer into contact with the developer carrying member to uniformly regulate the layer of the developer, and to provide a position opposed to the developer carrying member. In the developer regulating member used in a developing device having a developer regulating member in which an electrode for applying an oscillating voltage is arranged,
The developer regulating member includes an elastic base body, an electrode that is attached to the base body and is in contact with the developer carrying body that is covered with a high resistance layer, and a support that supports the base body to which the electrode is attached to a developing device. A member, the electrode and the high resistance layer are formed in a convex shape with respect to the base body and brought into contact with the developer carrier, and a portion of the convex portion that abuts the developer carrier. The radius of curvature of is in the range of 0.25 to 1.0 mm.

According to the second invention of the present application,
In the first aspect of the invention described above, the convex portion is arranged at the free end of the base, and the distance between the fulcrum of the base and the point where the extension line of the supporting member intersects the developer carrying member is l ₀ . Assuming that the distance between the contact point of the base body in the absence of the carrier with the developer carrying member and the fulcrum of the base body is l _{1 and} the distance from the fulcrum of the base body to the convex portion is l ₂ , l ₀ ≤l ₂ ≤l it is achieved by a _1.

Further, according to the third invention of the present application,
The above-mentioned object is to provide a developing device having a developer regulating member in which an electrode for applying an oscillating voltage is arranged at a position facing the developer carrying member so as to uniformly regulate the layer of the developer by contacting the developer carrying member. In the developer regulating member used, the developer regulating member is arranged such that an area ratio of the electrode within an effective contact width between the electrode and the developer carrying member is 1.0 or less. Achieved by

According to the fourth invention of the present application,
The above-mentioned object is to provide a developing device having a developer regulating member in which an electrode for applying an oscillating voltage is arranged at a position facing the developer carrying member so as to uniformly regulate the layer of the developer by contacting the developer carrying member. In the developer regulating member used, a plurality of the electrodes are provided, and each electrode is arranged in parallel in the longitudinal direction of the developing regulating member.

Further, according to the fifth invention of the present application,
The above-mentioned object is to provide a developing device having a developer regulating member in which an electrode for applying an oscillating voltage is arranged at a position facing the developer carrying member so as to uniformly regulate the layer of the developer by contacting the developer carrying member. In the developer regulating member to be used, a plurality of the electrodes are provided, and the electrodes are arranged in the longitudinal direction of the developing regulating member while alternately intersecting each other.

According to the sixth invention of the present application,
The above object is achieved by using the developer regulating member according to any one of the first to fifth inventions of the present application in the developing device.

Further, according to the seventh invention of the present application,
The above object is achieved by using the developing device of the sixth invention according to the present application in an image forming apparatus.

According to the eighth invention of the present application,
The above object is achieved by using the developing device of the sixth invention according to the present application in a process cartridge which is detachably mountable to the main body of the image forming apparatus.

[0035]

According to the first invention of the present application, the electrode which is in contact with the developer carrying member to uniformly regulate the layer of the developer and which is applied with the oscillating voltage at the position facing the developer carrying member is provided. In the developer regulating member used in the developing device having the developer regulating member arranged, since the electrode and the high resistance layer are formed in a convex shape with respect to the substrate and are brought into contact with the developer carrying member,
The capacitance decreases. Further, by forming the electrode in a convex shape and setting the radius of curvature of the abutting portion of the developer carrying member to 0.25 to 1.0 mm, the abutting range with respect to the developer carrying member is expanded as compared with the conventional case. Positioning becomes easy and cost is reduced.

In the second invention of the present application, in the developer regulating member of the first invention, the electrode is arranged at the free end of the developer regulating member and the contact range is set as described above. By doing so, in addition to the same effect as in the first aspect of the invention, the contact with the developer carrying member is further stabilized, and the toner coating amount is stably controlled.

Further, according to the third invention of the present application,
Since the developer regulating member is arranged so that the area ratio of the electrode within the effective contact width between the electrode and the developer carrying member is 1.0 or less, the electrostatic capacity is reduced, and from the electrode side. As it can be seen, the contact range within the effective contact width is expanded, which facilitates positioning and reduces cost.

According to the fourth invention of the present application,
Since a plurality of electrodes are provided and the electrodes are arranged in parallel in the longitudinal direction of the development regulating member, the contact range of the electrodes with respect to the developer carrying member is further expanded and the electrostatic capacity is further reduced.

Further, according to the fifth invention of the present application,
Since a plurality of electrodes are provided and the electrodes are arranged alternately in the longitudinal direction of the development restricting member while intersecting each other, the contact range of the electrodes with respect to the developer carrying member is further expanded and the electrostatic capacity is reduced.

Further, in the sixth invention according to the present application, by using the developer regulating member of each of the above inventions in the developing device, a high quality image due to the effect of the blade bias can be obtained.
Moreover, it can be obtained at low cost.

Further, in the seventh invention of the present application, by using the developing device of the sixth invention in an image forming apparatus, a high-quality image due to the effect of blade bias can be obtained at a low cost. .

Further, in the eighth invention of the present application, by using the developing device of the sixth invention in an integrated cartridge, image stability, which is an advantage of the cartridge, can be obtained.
In addition to easy maintainability, a higher-quality image due to the effect of blade bias can be obtained at low cost.

[0043]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) FIG. 1 is an enlarged view of a part of a cross section of a developing device which best shows the features of the first embodiment of the present invention, and FIG. 2 shows a developer regulating member used therein. FIG. 3 is a cross-sectional view, FIG. 3 is a view showing how the developer regulating member contacts the developing sleeve, and FIG. 4 is a view showing an image forming apparatus using the present invention. In each drawing, common components are denoted by the same reference numerals.

In FIG. 1, a developing blade 1 as a developer regulating member has a blade base 1b made of an elastic material such as urethane, silicone, chloroprene, and fluorine rubber, and urethane is provided on the contact surface side with a developing sleeve 2 as a developer carrying member. A high resistance layer 1c made of silicone, nylon or the like is provided. The electrode member 1a is disposed inside the high resistance layer 1c and is in contact with the developing sleeve 2 via the high resistance layer 1c. The electrode member 1a and the high resistance layer 1c are the blade base 1b.
Is formed in a convex shape, and the convex portion is in contact with the surface of the developing sleeve.

The developing blade 1 is fixed to a supporting member 1d made of sheet metal or the like, and then arranged in the developing container 6 so as to have a predetermined contact pressure with the developing sleeve 2. The developing sleeve 2 rotates in the direction shown by the arrow in the drawing while holding the toner as a developer on the surface thereof in the developing container 6, and at the contact portion with the developing blade 1, a thin layer formation of toner and triboelectric charging are performed. After that, the photosensitive drum 111 as an image carrier shown in FIG.
The toner is conveyed to a portion opposite to and the electrostatic latent image is developed.
A predetermined developing bias is applied to the developing sleeve 2 from a bias power source 4 via a sliding contact (not shown).

The present invention will be described in detail below with reference to actual examples. The developing blade 1 shown in FIGS. 2 and 3 has a structure in which a high resistance layer 1c made of a nylon resin having a thickness of 0.1 mm is coated on the periphery of an electrode member 1a made of a metal wire having a diameter of 1.0 mm. It is formed by adhering to an elastic substrate 1b made of 1.0 mm urethane rubber.

As the electrode member 1a, a conductive wire having a predetermined outer diameter, for example, a fine metal wire, carbon fiber or the like can be used. Also, the high resistance layer 1c
May be formed to have a constant thickness around the electrode member 1a, and the manufacturing method is not limited to this. For example, it may be formed by extruding resin around a metal wire and adhering it to the elastic body 1b. Alternatively, a conductive resin material is used as the electrode member 1a, and the high resistance layer 1c is formed after being formed on the base body 1b.
May be formed.

FIG. 3 shows how the developing blade 1 contacts the developing sleeve 2. In the figure, 1c 'and 1c "represent the upper and lower limit positions where the convex portions contact the sleeve. The range in which the sleeve 2 and the electrode 1a of the blade 1 can contact is
Conventionally, it is L'when there is no convex portion, but it is enlarged to L by making the electrode 1a convex.

In the example of FIG. 1, the developing sleeve 2 has a diameter of 1
6.0 mm, urethane rubber is used as the elastic body 1b, the height h of the convex portion is 1.2 mm, and the electrode width w is 1.0 mm.
Then, the range in which the electrode 1a can abut the sleeve 2 is changed from the conventional L '= 1.0 mm to L = 3.5 in the present embodiment.
Can be widened to mm. As a result, the accuracy tolerance of manufacturing the blade 1 and mounting it on the developing device can be increased.

Next, by using the developing device of FIG. 1 and the image forming device of FIG. 4, the width of the convex portion (electrode width) was changed to perform image evaluation, and the result of the experiment on the necessary width of the convex portion was performed. explain. The process speed was 50 mm / sec, and the developing blade 1 was set so as to come into contact with the developing sleeve 2 at a linear pressure of about 40 gf / cm. As the toner, a negatively chargeable magnetic one-component toner having an average particle size of about 6 μm is used. A non-magnetic aluminum sleeve having a diameter of 16 mm is used as the developing sleeve 2, and a magnet 3 in which N poles and S poles are alternately arranged is arranged in the sleeve. Further, in the developing sleeve 2, a DC voltage: Vdc = -400v, an AC voltage: amplitude Vpp = 1.6KVpp, a frequency f = 1800Hz.
A developing bias 4 such as (rectangular wave) is applied to the electrode member 1a of the blade, DC voltage: Vdc = 0V, AC voltage: amplitude Vpp = 0.8KVpp, frequency f = 500H.
A bias 5 such as z (sine wave) is applied while controlling each constant voltage. Due to the effects described above, the uniformly charged toner can be used for development.

With the above specifications, the electrode width is 0.1 to
Image formation was performed by changing each 0.1 to 2.0 mm, and image unevenness, reversal fog, and sleeve ghost were evaluated. As a result, the electrode width on the surface facing the developing sleeve is 0.5.
If it is larger than mm, there is a blade bias effect,
It was confirmed that a good image was obtained. However, below that, the strength of the above effect was uneven, and streaks were generated. On the other hand, as the electrode width increases, the contact latitude with the developing sleeve increases, but the electrostatic capacity increases. Therefore, the electrode width is preferably in the range of 0.5 to 2.0 mm.
Therefore, the shape of the convex portion has a radius of curvature of 0.25 to 0.25 in the portion that contacts the developing sleeve 2 as in the two examples shown in FIG.
It should be 1.0 mm. In addition, the electrode 1 of the present embodiment
Since a has a cylindrical shape in the surface thereof facing the developing sleeve 2, the capacity is smaller than that in the case where the plate electrode has the same width.

In this structure, by forming the blade electrode 1a and the high resistance layer 1c on the convex portion, the range of contact with the sleeve 2 can be widened as compared with the conventional case, so that the electrostatic capacity is reduced and the positioning is easy and the cost is low. It is possible to achieve both reductions.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

5 and 6 are partial sectional views showing the contact between the developing blade 1 and the sleeve 2 according to the second embodiment of the present invention.
The present embodiment is characterized in that the convex portion is provided with a certain curvature and is arranged at the free end of the blade 1. Other than that, it is the same as that described in the first embodiment.

In FIG. 5, the fulcrum of the developing blade 1 is O, the extension of the blade supporting member 1d and the fulcrum of the sleeve 2 are A, and the contact point where the tangent of the developing sleeve 2 is coincident with the fulcrum of the developing blade 1 is B. And The actual contact point C of the developing blade 1 is located between A and B. This depends on the elastic modulus of the elastic body. In this embodiment, the convex portion is arranged at the free end of the developing blade 1. Therefore, assuming that OA is l ₀ , OC is l ₁ , and the distance from the blade fulcrum to the convex portion (free end) is l ₂ , if l ₀ ≤l ₂ ≤l ₁ , the developing blade 1 is a convex portion. It surely contacts the sleeve 2.

In the case of the conventional developing blade, there is a difference in the toner coating amount depending on the distance l ₃ from the contact portion with the developing sleeve 2 to the free end. When l ₃ is large, the coat amount is large, and conversely, when it is small, the coat amount is small.
Then, when abutting at the free end, the toner was scraped by the developing blade 1 and a predetermined coating amount could not be obtained.

In the developing blade 1 of this embodiment, the contact portion with the developing sleeve 2 has a circular cross section, so that the distance l ₂ from the fulcrum of the developing blade 1 to the convex portion is l ₀ ≤l ₂ ≤l even vary in ₁ range, always developing sleeve 2 as shown in FIG. 6, the inlet shape of the developing blade 1 becomes similar.
Therefore, the contact state is stabilized, and the free end has a constant curvature, so that the toner can be regulated to a predetermined amount.

If the diameter of the convex portion is too small, the toner coating amount becomes small, and if it is large, the electrode width becomes large.
The capacitance will increase.

An image was formed by changing the diameter of the convex portion by the same image forming apparatus as in the first embodiment, and image unevenness, reversal fog and sleeve ghost were evaluated. as a result,
The radius of curvature of the convex portion is in the range of 0.25 to 1.0 mm, and it is possible to obtain the effect of reducing the electrostatic capacity without compromising the effect of the blade bias as compared with the conventional one, and achieving both ease of assembly and attachment and cost reduction. It was

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 7 is an enlarged view of a part of the cross section of the developing device that best shows the characteristics of the third embodiment of the present invention, FIG. 8 is a cross-sectional view of the developer regulating member used therein, and FIG. 9 is the developer regulating member. FIG. 10 is a diagram showing a state in which the toner contacts the developing sleeve, and FIG. 10 is a diagram showing an image forming apparatus using the present invention. In each figure,
Common configurations are denoted by the same reference numerals.

In FIG. 8, the developing blade 1 as a developer regulating member has a blade base 1b made of an elastic material such as urethane, silicone, chloroprene, and fluorine rubber, and urethane is provided on the contact surface side with the developing sleeve 2 as a developer carrying member. A high resistance layer 1c made of silicone, nylon or the like is provided.

A fine electrode member 1 is provided at the boundary between the base 1b and the high resistance layer 1c and near the contact position with the developing sleeve 2.
A plurality of a are arranged at predetermined intervals in the longitudinal direction of the developing blade 1. With such a configuration, by setting the area ratio of the electrode portion within the effective contact width between the developing sleeve 2 and the electrode 1a to 1.0 or less, the electrostatic capacitance can be maintained while maintaining the effective contact width as in the conventional case. When using a conventional electrode, it can be reduced to the following.

When the electrode member 1a is formed of a resin material, the kind of the resin material is not particularly limited, but the adhesion between the electrode member 1a, the high resistance layer 1c and the base body 1b is ensured. Therefore, a material compatible with at least one of the high resistance layer 1c and the substrate 1b is desirable. As for the conductive powder added to reduce the resistance, carbon-based materials such as carbon black and graphite as well as S
Metal oxides such as nO ₂ , TiO ₂ and ZnO can also be used. An example of the electrode member 1a using a resin material is a two-component curing type urethane resin in which carbon black is added to form a conductive paint, and screen printing is performed on the substrate 1b in a desired plurality of linear patterns. Can be performed, and then hardening by heat treatment can be performed. Further, as another form of the electrode member 1a, the same effect can be obtained by disposing a plurality of conductive wires having a predetermined outer diameter in the longitudinal direction. As the conductive wire, for example, a fine metal wire or carbon fiber can be used.

FIG. 8 is a view of the longitudinal direction of the developing blade 1 as seen from the inside of the developing container, and FIG. 9 is an enlarged view of the electrode portion thereof. The electrode member 1a has a width w and the developing blade 1a has a width w. In the portion corresponding to the contact position of the first developing sleeve 2 with
In a predetermined range (effective contact width; supported by X in the figure), a plurality of electrodes are arranged in parallel in the longitudinal direction at the interval w ', and the electrode member 1a is electrically connected at one end thereof. They are bundled to form the power feeding unit 1a '. At this point, the area ratio of the electrode within the effective contact width is w / (w +
w '). Then, the bias power source 5 is connected to the power feeding section 1a 'so that a predetermined bias is applied. The electrode width w and the number thereof mainly contribute to the effect degree of the present method, and the larger the electrode width w and the larger the number, the greater the effect.

Further, the ratio of the interval w'to the electrode width w mainly contributes to the electrostatic capacity, and the electrostatic capacity can be reduced as the interval w'is larger than the electrode width w. That is, if the area ratio is 1. It should be 0 or less. The range X of the electrode arrangement mainly contributes to the ease of attachment, and if the range X is wide, the contact position with the developing sleeve 2 may be located in any of the ranges, so that the range X with respect to the developing sleeve 2 can be improved. Positioning becomes easy.

The developing blade 1 is fixed to a supporting member 1d made of sheet metal or the like, and then arranged in the developing container 6 so as to have a predetermined contact pressure against the developing sleeve 2. The developing sleeve 2 rotates in the direction shown by the arrow in the drawing while holding the toner as a developer on the surface thereof in the developing container 6, and at the contact portion with the developing blade 1, a thin layer formation of toner and triboelectric charging are performed. After that, the photosensitive drum 11 as an image carrier shown in FIG.
Toner is conveyed to a portion facing 1 to develop the electrostatic latent image. A sliding contact (not shown) is provided on the developing sleeve 2.
A predetermined developing bias is applied from the bias power source 4 via the.

An image forming apparatus using such a developing device is shown in FIG. In the figure, the toner as a developer is shown by 7, and the other components having the same structure in FIGS. 7 to 9 are shown by the same symbols. The necessary width w of the electrode member 1a and the like will be described below with reference to actual examples of the present invention.

As the developing blade, a plate material made of urethane rubber having a thickness of 1.0 mm is used for the base body 1b, and the high resistance layer 1c.
The used nylon was 0.3 mm thick. Electrode member 1a
Is a two-component curing type urethane resin, carbon black is added to the conductive coating with a volume resistance of 1 × 101 Ω · cm or less on the substrate 1b by screen printing in a desired plurality of linear patterns, followed by heat treatment. What was hardened by was used. In the present study, the electrode range X is set to 2.0 mm, which allows a sufficient margin at the time of mounting, and the interval w ′ is set to w ′ = 3w so that the capacitance is sufficiently smaller than that of the conventional type electrode. , 1/4 of the conventional one. The area ratio is 0.25. Then, under this condition, in order to investigate the factor of the electrode width w, the electrode width w is set to 30, 60, 9
The development blade 1 was changed to 0, 150, 300, and 500 (μm) and examined.

The developing blade 1 has a linear pressure of 40 gf / cm.
It was set so as to come into contact with the developing sleeve 2 in a certain degree. As the toner, a negatively chargeable magnetic one-component toner having an average particle size of about 6 μm is used. The developing sleeve 2 is a non-magnetic aluminum sleeve having a diameter of 16 mm, and the sleeve has a north pole and a south pole.
Magnets 3 having poles arranged alternately are arranged. Further, the developing sleeve 2 has a DC voltage: Vdc = -400.
v, AC voltage: amplitude Vpp = 1.6KVpp, frequency f
= 1800 Hz (square wave) development bias 4
Further, the DC voltage: Vdc is applied to the electrode member 1a of the blade 1.
= -600V, AC voltage: Amplitude Vpp = 0.8KVp
Bias 5 such as p and frequency f = 1800 Hz is applied such that the phases thereof are opposite to each other while constant voltage control is performed.

Table 1 shows the results of image evaluation by using the developing blades having various electrode widths with the process speed of 50 mm / sec with the above specifications.

[0072]

[Table 1]

The three items from the top of Table 1 relate to the specifications of the electrode member 1a. The electrode width w, the interval w ', and the number of electrodes (the number of electrodes that can be arranged in the electrode arrangement range is 20 mm). Are listed respectively. The following three image evaluation results are used to evaluate image unevenness, reversal fog, and sleeve ghost. The rightmost end of the table is the result when the conventional type electrode member shown in FIG. 16 is used.
According to the results in the table, the effect of blade bias increases as the electrode width increases, and the effect equal to that of the conventional type electrode can be obtained when the electrode width is 90 μm or more. Therefore, in order to satisfy all the third items of the image evaluation, the electrode width w needs to be 90 μm or more.

As described above, according to the third embodiment of the present invention, by making the electrode width fine and arranging a plurality of electrodes in parallel with the longitudinal direction of the developing blade, the original effect of the blade bias type is not impaired. In addition, since the electrostatic capacity can be reduced while maintaining a sufficient effective contact width with the developing sleeve, it is possible to achieve both easy positioning of the electrode portion and the sleeve and cost reduction.

In this embodiment, the developing device using the magnetic one-component toner has been described, but the effect of the present invention is that the developing device using other kinds of toner (for example, non-magnetic toner) is used. The same effect can be obtained in the device.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIGS. 11 and 12. The same parts as those of the third embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 11 shows a developing blade used in the fourth embodiment of the present invention. The feature of this embodiment is that the fine electrodes are arranged in the longitudinal direction of the developing blade while intersecting each other. Except for the constitution of the electrode 9a of this embodiment (the material used for the electrode 9a, other constitutions and the material thereof), it is the same as that described in the third embodiment.

FIG. 12 is an enlarged view of a part 10 of the electrode shown in FIG. As shown in the figure,
The fine electrodes 9a have a predetermined width w and a predetermined interval w ', and are arranged in the electrode range X so that the electrodes intersect with each other (also electrically connected). Therefore, even if a part of the electrode 1a is lost during manufacturing or use for some reason, all the paths to which the bias is applied are not blocked, so that a stable blade bias effect can be obtained in the longitudinal direction. be able to.

Also, by intersecting the electrodes,
The effect of the blade bias itself is the same as that described in the third embodiment. It is the developing sleeve 2
The toner carried on the microelectrodes 9a in the electrode range X is
This is because the path that passes through the electrode 1a obliquely passes through the electrode 1a, and therefore becomes a longer path than when the electrodes are arranged in parallel (third embodiment), and a sufficient blade bias effect is obtained.

The results of examination in actual examples are shown below. w = 90
The developing blade 9 was prepared by performing screen printing with the above-mentioned conductive resin material under the specifications of μm, w ′ = 270 μm, X = 20 mm, and the intersecting angle of each electrode 9a of 90 °. Even in this configuration, the capacitance is
The entire mm width could be reduced to 1/4 of that of the electrode. Then, when an image was formed using this blade under the experimental conditions shown in the third embodiment, an image having no problem was obtained in any of the items of image unevenness, reversal fog, and sleeve ghost.

As described above, according to the fourth embodiment of the present invention, by making the electrode width fine and arranging the electrodes in the longitudinal direction of the developing blade while intersecting the electrodes, the original effect of the blade bias system is obtained. Capacitance can be reduced without damaging the effective contact width with the developing sleeve, and even if a part of the electrode is lost, the effect in the longitudinal direction does not decrease. It is possible to achieve both easy positioning of the blade and the sleeve and cost reduction, and also increase the reliability of the blade itself.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to FIG. The same parts as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted.

The feature of this embodiment resides in that the developing device using the developing blade described in the above embodiment is provided in an integral type cartridge which can be replaced together with other devices for the same life.

FIG. 13 is a diagram showing an example of an image forming apparatus using the integrated cartridge. The same components as those of the image forming apparatus described in the previous embodiment are designated by the same reference numerals.
In this embodiment, a developing device including a developing blade 1, a developing sleeve 2, a magnet 3, and a toner container 6 containing a toner 7, a photosensitive drum 111, and a cleaning blade 113.
Also, the cleaning device having the cleaning container 112 and the charging device 103 are connected by the exterior 11 to form an integrated cartridge.

In the case of this integral type cartridge, when the toner 7 is used up, other devices are designed to reach the end of their lives almost at the same time.

Therefore, the user can always obtain a stable image while the toner in the cartridge is present, and since it is an integral type, it has the advantage that it can be easily replaced. Further, by using the blade of the present invention in the developing device in the cartridge that adopts the blade bias system that can obtain good image quality, in addition to the advantages inherent to the integrated cartridge, the blade can be easily attached on the cartridge side. It is possible to add the advantage that the manufacturing cost can be reduced by simplifying the manufacturing process and the cost of the power source can be reduced by reducing the capacitance on the main body side.

[0087]

As described above, the first aspect of the present application
According to the invention, by forming the electrode and the high resistance layer in a convex shape on the substrate and contacting the developer carrying member, the electrostatic capacity is reduced, and both easy positioning and cost reduction are achieved. It is possible to provide a developer regulation member that can be achieved.

According to the second invention of the present application,
In the developer regulating member of the first invention, since the electrode is arranged at the free end of the developer regulating member, the contact of the developer regulating member can be further stabilized in addition to the effect of the first invention. Therefore, it is possible to provide the developer regulating member capable of stabilizing the control of the toner coating amount.

Further, according to the third invention of the present application,
Since the area ratio of the electrode within the effective contact width of the electrode with the developer carrying member is 1.0 or less,
Development that can reduce the electrostatic capacity while maintaining the effective contact width with the developer bearing member without impairing the effect of the conventional blade bias and achieving both positioning ease and cost reduction An agent regulating member can be provided.

According to the fourth invention of the present application,
Since a plurality of electrodes are provided and the electrodes are arranged in parallel in the developer regulating member longitudinal direction, the blade bias effect of the prior art is not impaired and the effective contact width with the developer carrying member is further increased as compared with the third invention. It is possible to provide a developer regulating member capable of reducing the electrostatic capacity while maintaining the above-mentioned value sufficiently, and achieving both easy positioning and cost reduction.

Further, according to the fifth invention of the present application,
Since there are multiple electrodes and the electrodes are arranged in the developer regulating member longitudinal direction while alternately intersecting each other, the effect of the blade bias as compared with the conventional one is not impaired, and the effective contact width with the developer carrier is sufficiently maintained. As it is, the electrostatic capacity can be reduced, the positioning is easy and the cost can be reduced at the same time, and the effect of the blade bias is not reduced even if a part of the electrode is lost. it can.

Further, in the sixth invention according to the present application, by using the developer regulating member of each of the above inventions in the developing device, a high-quality image due to the effect of the blade bias can be obtained.
Moreover, a developing device that can be obtained at low cost can be provided.

Further, according to the seventh invention of the present application,
By using the developing device of the sixth aspect of the invention, it is possible to provide an image forming apparatus capable of obtaining a high-quality image due to the effect of the blade bias and at a low cost.

According to the eighth invention of the present application,
By using the developing device of the sixth aspect of the invention in an integrated type cartridge, in addition to the image stability and easy maintainability, which are the advantages of the cartridge, an even higher quality image can be obtained at a low cost due to the effect of the blade bias. A process cartridge can be provided.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a developing device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a developer regulating member according to the first embodiment of the present invention.

FIG. 3 is a partially enlarged view of a developer regulating member and a developer carrier in the first embodiment of the present invention.

FIG. 4 is a diagram of an image forming apparatus using the developing device according to the first embodiment of the present invention.

FIG. 5 is a partially enlarged view of a developer regulating member and a developer carrying member according to the second embodiment of the present invention.

FIG. 6 is a partially enlarged view of a developer regulating member and a developer carrying member according to the second embodiment of the present invention.

FIG. 7 is a partial cross-sectional view of a developing device according to a third embodiment of the present invention.

FIG. 8 is a view showing a longitudinal direction of a developer regulating member according to a third embodiment of the present invention.

FIG. 9 is a partially enlarged view in the longitudinal direction of the developer regulating member according to the third embodiment of the present invention.

FIG. 10 is a diagram of an image forming apparatus using a developing device according to a third embodiment of the present invention.

FIG. 11 is a diagram showing a longitudinal direction of a developer regulating member according to a fourth embodiment of the present invention.

FIG. 12 is a partially enlarged view in the longitudinal direction of a developer regulating member according to a fourth embodiment of the present invention.

FIG. 13 is a diagram of an image forming apparatus using a developing device according to a fifth embodiment of the present invention.

FIG. 14 is a diagram of an image forming apparatus using a conventional developing device.

FIG. 15 is a diagram showing a conventional developing device.

FIG. 16 is a diagram showing a developing device using a blade bias.

FIG. 17 is a diagram showing the behavior of toner between a developer bearing member and a developer regulating member.

FIG. 18 is a diagram showing the behavior of toner between a developer bearing member and a developer regulating member.

FIG. 19 is a diagram showing the behavior of toner between a developer carrying member and a developer regulating member.

FIG. 20 is a diagram showing the behavior of toner between a developer carrying member and a developer regulating member.

[Explanation of symbols]

 1, 9 developing blade (developer regulating member) 1a, 9a electrode member 1b substrate 1c high resistance layer 1d supporting member 2 developing sleeve (developer carrying member) 11 process cartridge 101 image forming apparatus

Claims (8)

[Claims] 1. A developing device having a developer regulating member in which an electrode for applying an oscillating voltage is disposed at a position facing the developer carrying member to uniformly regulate the layer of the developer by contacting the developer carrying member. In the developer regulating member used for, the developer regulating member includes an elastic base body, an electrode attached to the base body, which is in contact with the developer carrying body and which is in contact with the developer carrying body, and the electrode is attached. And a support member for supporting the developed substrate on a developing device. The electrode and the high resistance layer are formed in a convex shape on the substrate and brought into contact with the developer carrying member. A developer regulating member, wherein a radius of curvature of a portion of the portion abutting the developer carrying member is in a range of 0.25 to 1.0 mm. 2. The convex portion is arranged at the free end of the base, the distance between the fulcrum of the base and the point where the extension line of the support member intersects the developer carrying member is l ₀ , and the convex portion has no convex portion. When the distance between the contact point of the developer carrier and the fulcrum of the substrate is l _{1 and} the distance from the fulcrum of the substrate to the convex portion is l ₂ , l ₀ ≤l ₂ ≤
The developer regulating member according to claim 1, wherein the developer regulating member is l ₁ . 3. A developing device having a developer regulating member in which an electrode for applying an oscillating voltage is arranged at a position opposed to the developer carrying member by abutting on the developer carrying member to uniformly regulate the layer of the developer. In the developer regulating member used for, the developer regulating member is arranged such that the area ratio of the electrode within the effective contact width between the electrode and the developer carrying member is 1.0 or less. A developer regulating member characterized by the above. 4. A developing device having a developer restricting member in which an electrode for applying an oscillating voltage is arranged at a position facing the developer carrying member so as to uniformly regulate the layer of the developer by contacting the developer carrying member. In the developer regulating member used in, the plurality of electrodes are provided, and each electrode is arranged in parallel in the longitudinal direction of the development regulating member. 5. A developing device having a developer restricting member in which an electrode for applying an oscillating voltage is arranged at a position facing the developer carrying member so as to uniformly regulate the layer of the developer by contacting the developer carrying member. In the developer regulating member used in, the plurality of electrodes are provided, and the electrodes are arranged in the longitudinal direction of the development regulating member while alternately intersecting each other. 6. A developing device using the developer regulating member according to any one of claims 1 to 5. 7. An image forming apparatus using the developing device according to claim 6. 8. A process cartridge using the developing device according to claim 6, wherein the process cartridge is detachable from an image forming apparatus main body.