JPH08314277A - Developing device - Google Patents

Abstract

PURPOSE: To form the image of high resolution where image density fluctuation caused by a jitter is prevented by supplying developer on a developer carrier after temporarily damming and storing charged developer in developer storage space constituted of partitioning members. CONSTITUTION: A carrier member 40 separates the developer 10 which remains on the developer carrier 20 after developing and carries it to the developer storage space 62. A stripping bias applying means 46 is provided between the carrier member 40 and the developer carrier 20, and bias voltage is appliedd so as to make the carrier member 40 have the potential of reverse polarity to the charge polarity of the developer against the developer carrier 20. Thus, only the developer 10 charged to a specified polarity is stored in the developer storage space 62 without incorporating the developer charged to the reverse polarity. The partitioning member 50 temporarily dams the developer 10 carried after stripped from the developer carrier 20 by the carrier member 40, and supplies the charged developer 10 on the developer carrier 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording device used in electrophotography and the like. More specifically, the electrostatic latent image formed on a latent image carrier is visualized by a developer. The present invention relates to a developing device, and more specifically, to a developing device that forms a thin layer of a developer on a developer carrying member to perform development.

[0002]

2. Description of the Related Art Conventionally, a developer carrying member carrying and carrying a developer, and a developing for visualizing an electrostatic latent image formed on the latent image carrying member by the developer on the developer carrying member As a device, a developing device using a two-component developer consisting of toner and carrier or a one-component developer consisting only of toner,
Various developing devices have been proposed. Various proposals have been made regarding the method of supplying the developer onto the developer carrying member. Particularly, in the case of a one-component non-magnetic developer that does not use magnetic force, it is difficult to stably supply the developer, and in recent years, many have been proposed. Has been made.

For example, a conventional developing device is disclosed in Japanese Unexamined Patent Publication No. 2-1.
As disclosed in Japanese Patent Publication No. 91974, a foamed elastic body is used as a supply member for supplying the developer onto the developer carrying member.

Further, as disclosed in US Pat. No. 4,990,958, the developer carrying member and the supply member are arranged in non-contact with each other, and a bias voltage is applied between the supply member and the developer carrying member. The developer is supplied onto the developer carrier, and then the developer is removed from the supply member.

Further, as disclosed in Japanese Patent Laid-Open No. 3-48877, a supply member facing the developer carrying member at a predetermined interval, a scraping member for scraping off the developer on the supply member, and a scraping member. Further, there is provided an accommodation section for accommodating the developer.

Further, as disclosed in Japanese Patent Laid-Open No. 62-89976, a developing roller, a developer replenishing device for replenishing the developing roller with the developer, and a friction charging device for the developer. Charging plate, a rotating member disposed between the developing roller and a side wall of the developer replenishing device on the upstream side in the developing roller rotation direction, and for removing the developer on the developing roller after development. It was a thing.

[0007]

However, in the conventional technique as disclosed in the above-mentioned JP-A-2-191974, the supply member holding the developer is brought into contact with or close to the developer carrier. Since the developer is configured to be sequentially supplied onto the developer carrying member while moving, fluctuations in the pressure contact force of the supply member with respect to the developer carrying member and quantitative unevenness of the developer held on the supply member occur, and However, there is a problem in that the image density fluctuates corresponding to the rotation cycle of.

Further, in the prior art as disclosed in US Pat. No. 4,990,958, the developer carrier and the supply member depend on the processing accuracy of the developer carrier and the supply member itself or the mounting accuracy at the installation position. When the toner is rotated, shake occurs and the strength of the bias electric field formed between the supply member and the developer carrying member fluctuates. Therefore, there is a problem that the image density fluctuates corresponding to the rotation cycle of the supply member. It was

Further, in the conventional technique as disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 3-48877, the developer charged by the regulating member remaining on the developer carrying body after the visible image is formed on the developer carrying body. Since the toner is continuously supported without being separated from the developer carrier, a difference is generated between the low-charged or uncharged developer newly supplied onto the developer carrier, and the developer on the developer carrier does not remain during image formation. There is a problem that a difference in density occurs between the consumption part and the consumption part.

Further, in the conventional technique as disclosed in the above-mentioned Japanese Patent Laid-Open No. 62-89976, the charged state of the developer stored in the hopper is not always stable and is supplied onto the developing roller. Image density and background fog (developer adhesion to non-image areas) due to changes in developer charge
There was a problem that the amount changed. The cause of the variation in the charge amount of the developer supplied to the developing roller is due to the type of image pattern to be developed and the idling drive of the developing device, and the charged residuals removed from the developing roller by the rotating member. This is because the developer directly returns to the hopper where the uncharged developer remains, and both the charged developer and the uncharged developer are supplied onto the developing roller.

The present invention solves the above-mentioned conventional problems, and an object thereof is to form a charged developer by a partition member without returning it directly into a hopper in which an uncharged developer remains. It is an object of the present invention to provide a developing device that starts the developing operation by supplying the developer onto the developer carrier after temporarily blocking and storing the developer in the developer storage space.

[0012]

According to a first aspect of the present invention, there is provided a developing device carrying a developer carrying a developer and carrying the developer, and the developer on the developer carrying body. In a developing device for visualizing an image, the developer carrying member is moved from a position where the developer carrying member and the latent image carrying member are opposed to each other and the regulating member for thinning the developer carrying member and charging the developer carrying member. And a partitioning member disposed downstream of the developer carrying member in the moving direction of the developer carrying member with respect to the position where the developer carrying member and the carrying member face each other. And a developer storage space constituted by a partition member and a developer carrier.

In the developing device according to the second aspect of the present invention, the maximum image forming width of the developing device is L (cm), and the radius of a circle inscribed in the conveying member, the partitioning member and the developer carrying member is r. (Cm), the following relationships are satisfied.

R ≧ 3.35 × 10 ⁻² L ^{1/2 Further} , in the developing device according to claim 3 of the present invention, the peeling bias for forming an electric field in a predetermined direction between the conveying member and the developer carrying member. The application means is provided.

According to a fourth aspect of the present invention, there is provided a scraping member for scraping off the developer on the conveying member.

Further, in the developing device according to claim 5 of the present invention, at the closest position where the partition member and the developer carrying member face each other, a tangent line passing through the closest contact point existing on the outer peripheral surface of the developer carrying member. And the tangent to the partition member passing through the closest contact point, and the developer advancing angle formed by θ (degrees),
This satisfies the relation of θ ≦ 90 °.

According to a sixth aspect of the present invention, there is provided a separating bias applying means for forming an electric field in a predetermined direction between the partition member and the developer carrying member.

Further, in the developing device according to claim 7 of the present invention, the partition member is a rotating body.

Further, in the developing device according to claim 8 of the present invention, a cleaning member for removing the developer is provided on the rotating body.

According to a ninth aspect of the present invention, in the developing device, the conveying member and the rotating member are rotated at a position where the conveying member and the developer carrying member face each other and at a position where the rotating member and the developer carrying member face each other. The moving direction of the body is the same as the moving direction of the developer carrying body.

According to a tenth aspect of the present invention, in the developing device, at least the partition member and the developer carrying member on the downstream side in the moving direction of the developer carrying member relative to the position where the partition member and the developer carrying member face each other. The stirring member is provided in the developer recovery space surrounded by the regulating member and the regulating member.

Further, in the developing device according to claim 11 of the present invention, when the gap between the outer peripheral surface of the developer carrying member and the outer peripheral rotation orbit of the stirring member is d1 (mm), d1 ≧ 1.
The relationship is satisfied.

[0023]

According to the first aspect of the present invention, the partition member facing the developer carrying member temporarily blocks and stores the developer charged by the regulating member in the developer storage space. Is brought to a desired state, and then the developer is supplied onto the developer carrier. The developer storage space includes a transport member, a developer carrier that is located on the downstream side in the moving direction of the developer carrier with respect to the position where the transport member faces the developer carrier, and a developer that is configured by a partition member. This is a space for making the charge state uniform and alleviating the change in the flow state of the developer, and by supplying the developer onto the developer carrier after passing through the developer storage space, the developer carrier It is intended to solve the problems caused by the fluctuation of the pressure contact force, the fluctuation of the bias electric field strength, and the fluctuation of the charge state of the developer, which occur between the charging member and the supply member. The conveying member always peels off the charged developer remaining on the developer carrying body without moving to the latent image carrying body when the latent image is made visible and when the developing device is driven to idle. Therefore, when the developer is carried on the developer carrying member, the chance of being stressed by the pressing of the regulating member is reduced. Further, in the above configuration, it is possible to supply the charged developer onto the developer carrying member without providing a mechanism for charging the developer except the regulation member. As described above, in the developing device of the present invention, the charged developer is temporarily blocked in the developer storage space to make the charged state of the developer uniform and to reduce the change in the flow state of the developer before development. The developer is supplied to the developer carrier to start the developing operation. According to the present developing device, the latent image remains visible on the developer carrier despite being charged by the regulation member, and a latent image is visualized. The charged developer which has not contributed to the above can be effectively utilized at the time of subsequent visualization.

According to the second aspect of the invention, the maximum image forming width of the developing device is L (cm), and the radius of the circle inscribed in the conveying member, the partitioning member and the developer carrier is r (c).
m), the relationship r ≧ 3.35 × 10 ⁻² L ^1/2 is satisfied. The inscribed circle in contact with the carrying member, the partitioning member, and the developer carrying member represents a spiral flow trajectory generated when the charged developer carried in the developer storage space flows, and the developer is the carrying member. And an outer peripheral orbit of a vortex that flows while being in contact with each of the partition member and the developer carrier. During image formation by the developing device,
Inscribed circle and maximum image forming width L by the radius r (cm)
The volume of the developer corresponding to the volume πr ² L (cm ³ ) of the cylinder composed of (cm) can be surely consumed at the time of image formation. The maximum amount of the developer is 0.4πr ² L (g). It is the amount of developer. When an image is formed using commercially available standard recording paper, the maximum consumption of the developer transferred onto the recording paper is
The developer adhesion amount per unit area is 1 × 10 ⁻³ (g / c
m ² ) and the maximum image forming width in the short side direction is L (cm), it is √2 × 10 ⁻³ L ² (g) in terms of a solid image.
At this time, the required amount of the developer in the developer storage space is represented by the following relational expression 0.4πr ² L ≧ √2 × 10 ⁻³ L ² corresponding to the volume of the cylinder described above. When the circular radius r of the columnar space that is inherent in is obtained, r ≧ 3.35 × 10 ⁻² L ^1/2 is derived. Therefore, in the developing device described above,
The volume of the developer storage space has a radius of 3.35 × 10 ^-2 L
A circle of ^1/2 (cm) or more is inscribed in the conveying member, the partitioning member, and the developer carrying member, and by satisfying the above conditions, a uniform solid image without insufficient density can be formed.

According to the third aspect of the invention, the peeling bias applying means for forming an electric field in a predetermined direction is provided between the carrying member and the developer carrying member, and the carrying member carries the developer. A bias voltage is applied to the body so as to have a potential having a polarity opposite to the charge polarity of the developer. The conveying member provided with the peeling bias applying means was charged to a predetermined polarity from the developer remaining on the developer carrier without shifting to the latent image carrier at a position facing the developer carrier. Only the developer is electrostatically peeled off from the developer carrier and conveyed to the developer storage space. Therefore, it is possible to store only the developer charged to the predetermined polarity in the developer storage space without mixing the developer charged to the opposite polarity.

According to the fourth aspect of the invention, by providing the scraping member for scraping the developer on the conveying member, the developer separated from the developer carrying member is scraped from the conveying member. Thus, the developer can self-flow in a fixed direction in the developer storage space. In the above configuration, the developer adhering to the carrying member is scraped off at any time by the scraping member, and the carrying member is always cleaned to reduce the efficiency of peeling the developer remaining on the developer carrier. In addition to preventing this, by sending the developer from the scraping portion on the transport member in one direction of the developer storage space, the developer self-flows so as to draw a spiral trajectory in the developer storage space, It is intended to prevent the static layer from being formed.

According to a fifth aspect of the present invention, at the closest position where the partition member and the developer carrying member face each other, a tangent line passing through the closest contact existing on the outer peripheral surface of the developer carrying member, When the tangent to the partitioning member passing through the closest contact point and the developer advancing angle formed by θ are degrees, θ ≦
It satisfies the 90 ° relationship. Here, the tangent line to the partition member forming the developer entry angle θ is determined with respect to the side wall of the partition member facing the developer storage space. When forming a thin layer of the developer at the position where the regulating member faces the developer carrier, the developer supplied onto the developer carrier preferably has a high packing density of the developer in advance, By making the developer advancing angle θ into a wedge shape with θ ≦ 90 °, the developer is gradually allowed to enter between the partition member and the developer carrying member and is densely packed on the developer carrying member. Can be supplied.
In the pressing portion by the regulating member, the densely packed developer is regulated without rearrangement on the developer carrier, so that a uniform thin developer layer can be formed without uneven layer thickness. .

According to a sixth aspect of the present invention, the separation bias applying means for forming an electric field in a predetermined direction is provided between the partition member and the developer carrying member.
A bias voltage is applied to the developer carrying member so that the partition member has a potential having a polarity opposite to the charge polarity of the developer.
The partition member provided with the separation bias applying means electrostatically separates the developer, which is charged in the opposite polarity, from the developer supplied onto the developer carrier at a position facing the developer carrier, on the partition member. Then, only the developer charged to a predetermined polarity is supplied to the regulation section.

According to a seventh aspect of the present invention, the partitioning member is a rotating body, and the rotating body is electrostatically separated from the developer carrying body to form an oppositely charged developer. The charge polarity of the developer to be supplied to the regulation portion can be more surely aligned by holding the above, and sequentially discharging the developer while rotating and moving to the developer recovery space.

According to the eighth aspect of the present invention, since the cleaning member for removing the developer is provided on the rotary member, the developer attached to the rotary member is removed by the cleaning member. The developer is discharged in a predetermined direction in the developer collecting space to promote the self-flow of the developer in the developer collecting space. Further, by constantly cleaning the rotating body with the cleaning member, it is possible to prevent the efficiency of separating the oppositely charged developer on the developer carrier from being lowered.

According to a ninth aspect of the present invention, the carrying member and the developer carrying member are opposed to each other and the rotating member and the developer carrying member are opposed to each other. The moving direction of the rotating body is the same as the moving direction of the developer carrying body. By being in the same direction as the moving direction of the carrying member and the developer carrying member, the developer can be efficiently carried when the carrying member separates and carries the residual developer from the developer carrying member, Release into the developer storage space is also facilitated. Further, by making the rotating body and the developer carrying body move in the same direction, the oppositely charged developer is efficiently separated when the rotating body separates the oppositely charged developer from the developer carrying body. Therefore, the developer can be easily released into the space.

According to a tenth aspect of the present invention, the agitating member includes the partition member, the developer carrying member on the downstream side in the moving direction of the developer carrying member with respect to the position where the partition member is disposed, and the regulating member. This is to stir the excess supply of developer accumulated in the developer recovery space surrounded by. The excess supply of developer that does not pass through the regulation section accumulates in the developer recovery space described above,
In particular, when the developer replenishing space or the developer storing space exists above the horizontal line passing through the rotation center axis of the developer carrier, the reflux to the developer replenishing space or the developer storing space is unlikely to occur. The agitation member agitates the developer accumulated in the developer recovery space to promote reflux to the developer replenishment space or the developer storage space, and prevents the developer from stagnating in the developer recovery space. It is a thing.

According to the eleventh aspect of the present invention, when the gap between the outer peripheral surface of the developer carrying member and the outer peripheral rotation orbit of the stirring member is d1 (mm), d1 ≧
1 is satisfied, and when the stirring member is rotationally driven to move the developer in the developer recovery space, the gap between the outer peripheral surface of the developer carrier and the outer peripheral rotation track of the stirring member is set to 1
(Mm) or more prevents the developer in the developer recovery space and the developer on the developer carrier from interfering with each other, and also prevents the developer on the developer carrier from being affected by the stirring member. It is to prevent being scratched off.

[0034]

1 is a schematic view of an image forming apparatus according to an embodiment of the present invention, in which a latent image carrier 1 is made of an organic or inorganic photoconductive material on a conductive support 2. The photosensitive layer 3 is formed. After charging the photosensitive layer 3 with a charger 4 such as a charging roller, light emitted from a light source 5 such as a laser or an LED is selected on the photosensitive layer 3 through an imaging optical system 6 according to an image. By irradiating light, a potential contrast is obtained to form a desired electrostatic latent image pattern.

The developing device 11 conveys and develops the developer 10. The regulating member 30 presses the developer carrier 20 which conveys the developer 10 by the regulating member 30 or the developer. The carrier 20 is elastically deformed, and the developer 10 is thinly layered at the pressing portion against the developer carrier 20 and is charged to a predetermined polarity, so that the developer 10 is directly held on the developer carrier 20 to be thin. In the layered state, the developer carrier 20 is moved to convey the developer 10 to the latent image carrier 1.

The developer bearing member 20 is disposed close to or in contact with the latent image bearing member 1 so as to face it, and the potential contrast of the latent image bearing member 1 and the latent image bearing member 1 and the developer bearing member at the facing portion. Bias applying means 2 applied between the body 20 (or between the latent image carrier 1 and the regulating member 30).
A developing electric field is formed by 6, and the latent image is visualized by the developer 10 charged according to the developing electric field. In this way, the electrostatic latent image pattern of the latent image carrier 1 is visualized by the charged developer 10. Further, the transfer device 7 such as a transfer roller is used to transfer the image of the developer 10 on the recording paper 8 and the developer 10 is fixed to the recording paper 8 by using heat or pressure to form a desired image on the recording paper 8. 8 can be formed.

For the photosensitive layer 3 of the latent image carrier 1, an organic or inorganic photosensitive material can be used. Arrows in the figure indicate the rotation directions of the respective members, and the latent image carrier 1 and the developer carrier 20 are shown.
The peripheral speed ratio with is preferably in the range of 1: 1 to 1: 5,
The present invention is not limited to these figures and numerical values.

As the developer 10, a magnetic toner or a non-magnetic toner can be used, and either a resin type toner or a wax type toner can be used. Also,
The developer 10 may include an external additive such as colloidal silica, and the structure thereof is not limited to one component, but when a one-component developer is used, the volume average particle diameter is 3 to. It is preferably in the range of 15 μm.

FIG. 2 is a schematic view of the vertical developing device 11 in one embodiment of the present invention.

The regulating member 30 is a blade-shaped member, and by pressing the developer 10 on the developer carrying member 20, the developer 10 is thinned and charged to a predetermined polarity, The carrier 20 is uniformly carried on the carrier 20. The thinned developer 10 is transferred onto the latent image carrier 1 at a position where the latent image carrier 1 and the developer carrier 20 face each other in accordance with the developing electric field to visualize the latent image. To do.

The carrying member 40 is the developer carrying member 2 after the development.
When the latent image carrier 1 and the developer carrier 20 face each other, the developer carrier 20 is moved from the position where the latent image carrier 1 and the developer carrier 20 face each other. The developer carrier 20 is disposed on the downstream side in the direction close to or in contact with the developer carrier 20, and is rotationally driven so as to move in the same or opposite direction with respect to the moving direction of the developer carrier 20. When the carrying member 40 is arranged in non-contact with the developer carrying body 20, the developer 10 remaining on the developer carrying body 20 after development is provided between the carrying member 40 and the developer carrying body 20. The peeling electric field formed by the peeling bias voltage means 46 causes the peeling on the conveying member 40, so that the conveying member 40 can be conveyed to the developer storage space 62 without increasing the driving torque. On the other hand, when the carrying member 40 is arranged in pressure contact with the developer carrying body 20, the developer 10 remaining on the developer carrying body 20 after development is mechanically peeled off while being neutralized by the carrying member 40. It is also possible to omit the peeling bias applying means 46 provided between the carrying member 40 and the developer carrying member 20 since the transfer is performed above the carrying member 40. At this time, the transport member 40 is rotationally driven so as to have a relative speed difference with respect to the moving direction of the developer carrier 20, so that the developer 10 on the developer carrier 20 is mechanically moved by the transport member 40. Peeling can be reliably performed.

A peeling bias applying means 4 for forming an electric field in a predetermined direction between the carrying member 40 and the developer carrying member 20.
6 can be provided, and the transport member 40 can be the developer carrier 2
A bias voltage is applied so that the potential of the developer has a polarity opposite to that of the charge polarity of 0. For example, when a negatively charged developer is used, a bias voltage is applied so that the transport member 40 has a positive polarity potential with respect to the development carrier 20. The conveying member 40 provided with the peeling bias applying means 46 is provided with a negative electrode among the developers remaining on the developer carrier 20 without moving onto the latent image carrier 1 at a position facing the developer carrier 20. The developer storage space 62 is formed by electrostatically peeling off only the developer that is electrically charged from the developer carrier 20.
It is to be transported to. On the other hand, when a positively charged developer is used, the bias electric field is set in the opposite direction to the above-mentioned configuration. Therefore, in the developer storage space 62, it is possible to store only the developer charged to the predetermined polarity without mixing the developer charged to the opposite polarity.

Further, by providing a scraping member 48 for scraping the developer on the conveying member 40, the scraping member 48 for scraping the developer 10 adhering to the developer carrier 20 is provided.
The developer storage space 62 can be scraped off and self-flowed in one direction. In the above configuration, the developer 10 adhering to the transport member 40 is scraped off at any time and the transport member 40 is constantly cleaned, so that the developer 10 remaining on the developer carrier 20 can be efficiently removed. The developer 10 is prevented from being lowered and the developer 10 is scraped off on the conveying member 40.
From the developer storage space 62 in one direction, the developer 10 is drawn so as to draw a spiral trajectory in the developer storage space 62.
Self-flowing to prevent the formation of a stationary layer.

The partitioning member 50 temporarily blocks the developer 10 transported after being separated from the developer carrying member 20 by the transporting member 40 and supplies the charged developer 10 to the developer carrying member 20. The developer carrying member 2
Regulating member 30 and developer carrier 20 with respect to the moving direction of 0
Are arranged as the limit line of the downstream section of the developer storage space 62 upstream of the position where they face each other.

As shown in FIG. 8, the partition member 50 is
At the closest position facing the developer carrying body 20, a tangent line α passing through the closest contact point existing on the outer peripheral surface of the developer carrying body 20 and a tangent line β with the partition member 50 passing through the closest contact point are When the advancing angle of the formed developer 10 is θ (degrees), the developer 10 is arranged in a wedge shape satisfying the relationship of θ ≦ 90 °. Here, the tangent β to the partition member forming the developer advancing angle θ is defined with respect to the side wall of the partition member 50 facing the developer storage space 62. When the thin layer of the developer 10 is formed at the position where the regulating member 30 faces the developer carrying body 20, the developer 10 supplied onto the developer carrying body 20 has a higher packing density of the developer in advance. It is preferable that the developer carrying angle θ is 90 ≦ 90 ° so that the developer is gradually introduced between the partition member 50 and the developer carrying body 20. It can be densely packed and supplied on top. In the pressing portion by the regulating member 30,
The densely packed developer 10 is regulated without rearrangement on the developer carrier 20, so that a uniform thin developer layer can be formed without uneven layer thickness. At this time, at the closest position where the partition member 50 and the developer carrying member 20 face each other, the effect can be further enhanced by setting the proximity distance to 3 (mm) or less. Therefore, by forming the developer formed of the partition member 50 and the developer carrying member 20 into a wedge shape with an approach angle θ of θ ≦ 90 °, a uniform thin developer layer having no layer thickness unevenness can be easily formed. be able to.

As shown in FIG. 7, the partition member 54 can be provided with a separation bias applying means 56 for forming an electric field in a predetermined direction between the partition member 54 and the developer carrying member 21.
Bias voltage is applied to the developer carrier 21 so that the developer carrier 21 has a potential having the same polarity as the charge polarity of the developer 10.
For example, when a negatively charged developer is used, a bias voltage is applied so that the partition member has a potential on the negative polarity side with respect to the developer carrier. On the other hand, when a positively charged developer is used, the bias electric field is set in the opposite direction to the above-mentioned configuration. Therefore, the partition member 54 provided with the separation bias applying unit 56 partitions the developer charged to the opposite polarity from the developer supplied onto the developer carrier 21 at the position facing the developer carrier 21. Only the developer which is electrostatically separated on the surface 54 and is charged to a predetermined polarity can be supplied to the regulation portion.

The partition member 54 may be a roller-shaped rotating member, and the partition member 54 is the developer carrying member 2.
By holding the oppositely charged developer that is electrostatically separated from above 1 and sequentially releasing it while rotating and moving it to the developer recovery space 63, the polarity of the charge of the developer 10 to be supplied to the regulation unit is more surely aligned. be able to. Further, a cleaning member 55 for removing the developer may be provided on the partition member 54, and the developer 10 adhering to the partition member 54 may be removed by the cleaning member 55 to move the developer recovery space 63 in a certain direction. It is possible to discharge and accelerate the self-flow of the developer 10 in the developer collecting space 63. Further, by constantly cleaning the partition member 54 with the cleaning member 55,
It is possible to prevent the efficiency of separating the oppositely charged developer on the developer carrier 21 from decreasing. At this time, at the position where the transport member 40 and the developer carrier 21 face each other and the position where the partition member 54 and the developer carrier 21 face each other, the transport member 40 and the partition member 54 move the developer carrier 21. The directions can be the same as each other. By making the conveying member 40 and the developer carrying member 21 move in the same direction, the developer 10 can be efficiently separated when the conveying member 40 separates and conveys the residual developer from the developer carrying member 21. Therefore, the developer can be easily discharged to the developer storage space 62. Further, the partition member 54 and the developer carrier 2
By making the moving direction of 1 the same direction, when the partitioning member 54 separates the oppositely charged developer from the developer carrier 21, the oppositely charged developer can be efficiently separated,
It becomes easy to discharge the developer into the developer collecting space 63.

As shown in FIG. 3, the developer replenishing space 61
Is a space for temporarily storing the newly replenished developer in the developing device, and has a so-called developer hopper function. Developer 1 in the developer supply space 61
Since 0 has no opportunity to be positively charged, the absolute value q1 of the specific charge amount of the developer becomes a very small value. In the developer storage space 62 that stores the developer charged by the regulation member 30, the developer 10 remaining on the developer carrier 20 without being developed is transported after being separated by the transport member 40 to newly carry the developer. It is a space for temporarily blocking and storing the developer 10 until it is supplied onto the body 20. Since the developer 10 stored in the developer storage space 62 is in the state of being provided with the triboelectric charge while being regulated in a thin layer by the regulating member 30, the absolute value q2 of the specific charge amount of the developer 10 is sufficiently large. It becomes a value. A developer collecting space 63 surrounded by the partition member 240 and the developer carrying member 20 and the regulating member 30 on the downstream side in the moving direction of the developer carrying member with respect to the arrangement position of the partition member 240.
Regarding the developer 10 supplied onto the developer carrier 20 from the developer storage space 62, it is removed from the developer carrier 20 when passing through the position where the partition member 50 and the developer carrier 20 face each other. When the developer having a low charge amount and the regulating member 30 and the developer carrying body 20 pass through the facing position, they do not pass and the supply surplus stays upstream of the facing position in the moving direction of the developer carrying body 20. Is a space for accommodating the developer. The developer accommodated in the developer recovery space 63 is excluded from the developer carrier 20 because the image force when the developer is carried on the developer carrier 20 is weak. The absolute value q3 of is a relatively small value. As shown in FIG. 3, the absolute value of the specific charge amount of the developer staying in each of the spaces has a relation of q1 <q3 <q2 by dividing the space where the developer stays in the developing device. If established, it is possible to form a thin layer of a developer having a good charge state on the developer carrying member. Further, in the developing device of the present invention, the developer carrier 20 and the transport member 40 are moved for a predetermined time in a state where an image is not formed on the latent image carrier 1 prior to the developing operation, and the developer is retained in the storage space 60. It is preferable to start the developing operation after the charge state of the agent is made uniform.

Further, as shown in FIG. 9, the developer storage space 6
Regarding the volume of 1, when the radius of the circle inscribed in the conveying member 40, the partitioning member 50, and the developer carrying member 20 is r (cm), r ≧ 3.35 × 10 ⁻² L ^1/2 It satisfies. The maximum image forming width L (cm) of the developing device is the maximum width of the latent image in the main scanning direction of the scanning optical system that can be formed on the latent image carrier 1.
It is the smaller of the maximum widths in the main scanning direction of the developer thin layer formed on the developer carrier 20. The inscribed circle that is in contact with the transport member 40, the partition member 50, and the developer carrier 20 is the developer 1 transported into the developer storage space 62.
It represents a spiral flow trajectory that occurs when the flow is zero,
The developer 10 is an outer peripheral track of a vortex that flows while approaching the transport member 40, the partitioning member 50, and the developer carrier 20, respectively. During image formation by the developing device, the inscribed circle with the radius r (cm) and the maximum image formation width L (c
m) is the amount of the developer corresponding to the volume πr ² L (cm ³ ) of the cylinder that can be reliably consumed during image formation, and the maximum amount of developer is kπr ² L (g) in terms of weight. Becomes Here, the constant k is an experimentally obtained filling weight per unit volume of the developer in the developer storage space 62, and k = 0.4 for the one-component nonmagnetic developer, and the one-component magnetic development. For the agent, k = 0.5. In the developing device,
As a one-component non-magnetic developer is used for the developer,
By adopting k = 0.4, a maximum of 0.4πr ² L (g) of developer can be consumed from the developer storage space 62. The developer in the developer storage space 62 is caused to flow in a spiral orbit because the developer discharged from the supply member does not flow directly in the direction of the developer carrying member, but the developer is stored as shown in FIG. After passing through the opening direction of the space 62, the developer carrier 20
The flow state (flow rate or flow rate) of the developer released from the transport member 40 by flowing in the direction of
This is because when the value changes, the change is alleviated. The above-mentioned cylindrical space and the vicinity thereof, the developer remaining in the space excluding the vicinity of the surface of the developer carrier is liable to become a stationary layer due to its poor self-fluidity, and especially the developer staying away from the spiral flow trajectory is It is substantially difficult to be supplied onto the developer carrying member 20 without stirring or vibration due to an external force.
The developer remaining in the vicinity of the cylindrical space in the opening direction of the developer storage space 62 is slightly affected by the vortex flow of the developer, and gradually flows from the vicinity of the portion facing the spiral trajectory in the same direction. In the vicinity of the surface of the developer carrying member 20, the developer moving in the same direction as the moving direction of the developer carrying member 20 and the developer flowing in the spiral trajectory merge in different directions at their contact portions. Accordingly, the developer is carried by the developer carrier 20.
Supplied on.

When an image is formed using commercially available standard recording paper, the maximum consumption of the developer transferred onto the recording paper is
The adhesion amount of the developer per unit area is 1 × 10 ⁻³ (g /
cm ² ) and the maximum image forming width in the short side direction is L (cm), it is √2 × 10 ⁻³ L ² (g) in terms of a solid image. The developer 10 supplied onto the developer carrying member 20 passes through the restricting member 30 and forms a thin layer developer without generating excess developer at the position where the restricting member 30 and the developer carrying member 20 face each other. Assuming that the latent image is visualized, the required amount of the developer 10 in the developer storage space 62 corresponds to the volume of the cylinder described above, and the following relational expression 0.4πr ² L ≧ √2 × When the circular radius r of the cylindrical space, which is represented by 10 ⁻³ L ² and is present in the developer storage space 62, is calculated, r ≧ 3.35 × 10 ⁻² L ^1/2 is derived. On the other hand, in order to uniformly thin the developer on the developer carrier 20, the regulation member 30 and the developer carrier 20
It is preferable that a developer having a layer thickness of 1.5 times or more of the developer formed after the regulation is carried on the upstream side in the moving direction of the developer carrying member 20 than the position where the two are opposed to each other. Minimum required amount of developer is 1.5 x √2 x 10 ^-3 L
² (g). The above relational expression is used when the development efficiency, which is the transfer rate of the developer from the developer carrier 20 to the latent image carrier 1, and the separation efficiency of the developer from the developer carrier 20 to the transport member 40 change. Also holds in. However, when the transfer efficiency, which is the transfer rate of the developer from the latent image carrier 1 to the recording paper 8, is low, the minimum required amount of the developer is 1.5 × √, considering the transfer efficiency t (%). 2 x 10 ^-3 L ² x 1 / t
(G) is preferable.

Therefore, in the above-described developing device, the volume of the developer storage space 62 is at least a radius of 3.35 ×.
It is necessary that a circle of 10 ^-2 L ^1/2 (cm) or more can be inscribed in the conveying member 20, the partitioning member 50 and the developer carrying member 20.

The stirring member 70 includes a partition member 50 and a developer recovery space 63 surrounded by the developer carrier 20 and the regulating member 30 on the downstream side in the moving direction of the developer carrier 20 with respect to the position where the partition member 50 is disposed. It is for stirring the excessive supply of the developer 10 accumulated in the above, and is provided in a non-contact state with the regulating member 30, the partitioning member 50, and the development carrier 20. In particular, the gap d1 between the outer peripheral surface of the developer carrier 20 and the outer peripheral rotation orbit of the stirring member 70 satisfies the relationship of d1 ≧ 1 (mm). When the stirring member 70 is rotationally driven to move the developer in the developer recovery space 63, the gap between the outer peripheral surface of the developer carrier 20 and the outer peripheral rotation track of the stirring member 70 should be 1 (mm) or more. This prevents the developer in the developer recovery space 63 and the developer on the developer carrier 20 from being mixed with each other, and the developer on the developer carrier 20 is scraped off by the influence of the stirring member 70. Can be prevented. Regulation member 30 and developer carrier 20
The surplus developer 10 that does not pass through the position where
Accumulation in the developer recovery space 63, especially the developer supply space 61
When the developer storage space 62 and the developer storage space 62 are located below the horizontal line passing through the rotation center axis of the developer carrier 20, the reflux to the developer supply space 61 and the developer storage space 62 is unlikely to occur. The stirring member 70 stirs the developer accumulated in the developer recovery space 63 in order to prevent the movement of the developer remaining in the developer recovery space 62 from stagnating.
Reflux to the developer supply space 61 or the developer storage space 62 is promoted. By refluxing the developer accumulated in the developer recovery space 63, the pressing force of the regulation member 30 against the development carrier 20 is prevented from being substantially weakened, and the solidification (blocking) caused by the compression of the developer 10 is suppressed. Can be prevented.

The developer carrying member 20 is formed by forming a cylindrical solid member made of a continuous elastic body such as rubber or elastomer having a film thickness of about several mm on the outer circumference of a shaft made of metal or resin. It is a roller-shaped rotating body integrally molded of metal or resin. In addition, the developer carrier 20
Is formed to have a surface roughness of about several μm in terms of Rz (JIS 10-point average surface roughness), and a bias applying means 26 is connected so that at least the surface is made conductive and a predetermined potential can be applied. are doing. Developer carrier 20
In the case where the latent image carrier 1 and the latent image carrier 1 are pressed against each other, for example, when the developing nip width in the pressing portion is about 1 mm and a printing speed of about 20 PPM is realized, a sufficiently small developing current can be applied to the developing current. A constant is required, and by setting the resistance of the developer carrier 20 to 10 ⁹ Ω or less, high resolution printing due to the developing electrode effect can be realized. Further, a seal member 27 made of a film-shaped resin or rubber may be provided on the developer carrying member 20 to prevent the developer from leaking from the developing device. The seal member 27 includes a latent image carrier 1 and a developer carrier 2.
At a position downstream of the position where 0 is opposed to the developer carrier 20 in the moving direction, and at a position upstream of the position where the carrier member 40 and the developer carrier 20 are opposed to each other in the direction of movement of the developer carrier 20, One end is fixed to the housing of the developing device, and the other end is arranged close to or in contact with the developer carrier 20.

For the above-mentioned solid member not shown, urethane rubber is used in this embodiment, but similarly, rubber such as natural rubber, silicone rubber, butadiene rubber, chloroprene rubber, neoprene rubber, EPDM, NBR, or the like, It is also possible to use an elastomer containing styrene resin, vinyl chloride resin, polyurethane resin, polyethylene resin, methacrylic resin, or the like. Further, by forming a flexible layer on the surface of the solid member, the friction load can be reduced, and the triboelectrification of the developer and the thin layer conveyance can be stabilized. Furthermore, the friction load is reduced by hardening the surface of the solid member using heat treatment or chemical treatment,
It is also possible to form a highly durable developer carrier.

The regulation member 30 is composed of a support member 31 that supports the contact member 32 and a contact member 32 that contacts the developer carrying member 20. As the contact member 32, a thin leaf spring made of metal and having a wall thickness of about several hundred μm, a rigid body made of metal or ceramics, or an elastic body made of rubber or elastomer can be used. Since the contact member 32 is easily deformed when pressed against the developer carrying member 20, it is fixed by the support member 31 having a relatively thick wall (the support member 31 having the rotation center is shown in FIG. 2). The contact member 32
Presses the developer carrier 20 via the developer 10 in the vicinity of the tip end on the side fixed to the support 31. In FIG. 2, the support 31 has a center of rotation, and the compression coil spring 35 is arranged on the side opposite to the side on which the contact member 32 is fixed to apply a moment. A coil spring or a leaf spring may be used. Regarding the pressing portion between the contact member 32 and the developer carrying member 20, by pressing the vicinity of the end of the contact member 32 against the developer carrying member 20, the developer 10 can be thinned at a low pressure of about several g / mm. It is possible to form a layer and suppress the occurrence of filming of the developer due to excessive pressure. In addition, the regulating member 30 removes the developer 10 from the developer carrying member 20 by providing a bent portion near the pressing portion of the regulating member 30 so as to correct the flow of the developer 10 or by adding a member for correcting the flow. The developer can be stably returned to the developer recovery space 63 (not shown). Materials used for the contact member 32 include metals such as steel, stainless steel, phosphor bronze, brass, and aluminum, ceramics such as alumina and silicon nitride, rubbers and resins such as silicon and urethane, and carbon black for these materials. It is a conductive material in which conductive fine powder such as is dispersed.

The surface of the abutting member 32 is coated with a charge control agent such as a metal complex dye or a quaternary ammonium salt so that the developer layer formed on the developer carrier 20 has insufficient charge. It is possible to reduce frictional electrification defects such as or excessive charging. Further, by applying a developing bias voltage to the contact member 32, electric charges of opposite polarity generated by frictional charging between the contact member 32 and the developer 10 are leaked to a power source or the like,
It is possible to prevent density fluctuation due to accumulation of unnecessary charges and maintain a stable developing state. However, in order to prevent the fixed layer from being generated due to the adhesion of the developer 10, it is preferable to apply the developing bias voltage to a member other than the insulating member.

The conveying member 40 is made of a metal or resin, and has a shaft made of metal or resin. The shaft is made of metal, resin, or a continuous elastic body such as rubber, elastomer, or sponge having a thickness of several mm. Roller-shaped rotating body integrally molded,
A loop-shaped rotating body in which an endless tube (or belt) is provided on the outer circumference of a shaft made of metal or resin can be used (a roller-like rotating body is shown in FIG. 2). It is preferable that at least the surface of the transport member 40 has conductivity, and the residual developer on the developer carrier 20 can be discharged by being pressed against the developer carrier 20 and driven to rotate. Further, the conductive carrier member 40 is electrically biased with respect to the developer carrying body 20 by the peeling bias applying means 46, so that the developer carrying body 2 is provided.
It is possible to more efficiently peel off the developer remaining on the surface. When the conveying member 40 is brought into the same potential as the developer carrying body 20 and is pressed against the developer carrying body 20 to be rotationally driven, the charge removal of the developer remaining on the developer carrying body 20 proceeds. The mechanical peeling of the residual developer can be efficiently performed. When the carrier member 40 is applied to the developer carrying member 20 with a potential having a polarity different from the charge polarity of the developer, the developer remaining on the developer carrying member 20 can be electrostatically peeled off. it can. At this time, the transport member 40 may be in pressure contact with or close to the development carrier 20. A scraping member 48 for scraping off the developer adhering to the transport member 40 is preferably disposed on the transport member 40. The scraping member 48 presses or brings one end of a thin film having a thickness of 1 mm or less against the conveying member 40 in the counter direction or in the trail direction so that the conveying member 4 can be pressed.
To mechanically scrape the developer adhering to
It is preferable to use an insulating member in order to prevent the developer from sticking. Scraping member 4 facing the transport member 40
One end of 8 can be chamfered like a knife edge to enhance the scraping effect of the developer.

The partition member 50 is a block-shaped member or plate-shaped member made of metal or resin, a rotary member formed of a cylindrical elastic body such as rubber on the outer circumference of a shaft made of metal or resin, or a metal or resin. An integrally molded roller-shaped rotating body can be used (a plate-shaped member is shown in FIG. 2). The partition member is 50, 51, 52, 53, in FIGS.
The shape shown as 54 is preferable, but the shape is not limited to the above. Further, the partition member is a block-shaped member or a plate-shaped member, at least a surface facing the developer carrying member, a rotary member in which an elastic member is formed in a cylindrical shape on the outer periphery of the shaft, or a roller-shaped rotary member integrally molded of metal or resin. It is preferable that at least the surface of the above is made conductive, and the conductive partition member can be electrically biased with respect to the developer carrying member 20 by a separation bias applying means. At this time, the partition member may be in pressure contact with or close to the developer carrying member. A restriction member may be used as a modification of the partition member.

The cleaning member 55 mechanically scrapes off the developer adhering to the rotating member by facing one end of a thin film of 1 mm or less to the rotating member so as to come into pressure contact with or close to the counter member or the trail direction. Is something
It is preferable to use an insulating film in order to prevent the developer from sticking. Cleaning member 55 facing the rotating body
One end of the developer can be chamfered like a knife edge to enhance the scraping effect of the developer.

The specific charge amount q of the developer remaining in each space partitioned by the partition member 50 is determined by sucking the developer into a suction cell for trapping the developer connected to the Q meter by a vacuum pump or the like. It can be obtained from the ratio of the integrated charge amount of the developer obtained and the mass ratio of the developer (not shown). A filter having a minute opening diameter (for example, a membrane filter having an opening diameter of 1 to 5 μm) is interposed in the suction cell for capturing the developer to capture the developer sucked together with air. In the above-mentioned measurement system, it is possible to use an ammeter instead of the Q meter, but in any case, the measurement system is installed in an electrically shielded space to prevent electrical noise from the outside. Is preferably shielded.

The stirring member 70 is composed of at least a shaft portion 71 made of metal or resin and a blade portion 72 made of a thin plate made of metal or resin. The partition member 50 has a distance of at least 1 mm or more from 20 and is surrounded by the developer carrying body 20 and the regulating member 30 on the downstream side in the moving direction of the developer carrying body 20 with respect to the arrangement position of the partitioning member 50. It is arranged in the developer collecting space 63.

As shown in FIG. 5, the developer replenishing space 61
A second stirring member 75 can be provided in (c) if necessary. When the developer existing in the developer supply space 61 (c) cannot flow back to the developer storage space 62 (c) due to free flow, or the developer existing in the developer supply space 61 (c) is compressed or self-weighted due to its own weight. If it is desired to prevent aggregation, the above phenomenon can be prevented by providing the second stirring member 75 and forcibly stirring the developer.

A more detailed embodiment will be described below.

[Embodiment 1] FIGS. 2 and 4 are schematic views of the vertical developing devices 11 and 12 according to an embodiment of the present invention, showing examples in which the disposing conditions of the conveying members are different from each other. .

The developer bearing member 20 is formed by forming a cylindrical solid member made of a continuous elastic body of urethane rubber on the outer circumference of a shaft made of metal. The surface roughness of the solid member is Rz (JIS. A soft pressure development is made possible by setting the 10-point average surface roughness) to 3 μm and the surface rubber hardness (JIS A) to 20 degrees. Further, the developer carrying member 20 has an electric resistance of 1 × 10 ⁶ Ω, and is electrically biased to the latent image carrying member 1 by the bias applying means 26 so that the developer 10 is charged negatively. A potential of the same polarity (-100 to -500V) is applied.

The regulating member 30 comprises a support 31 having a center of rotation and an abutting member 32 made of urethane rubber.
The developer carrying body 20 carrying the developer 10 is pressed by the compression coil spring 35 to push the developer carrying body 20.
The developer 10 is negatively charged at the contact portion with
The thickness is reduced to about 2 layers.

The carrying member 40 shown in FIG. 2 is a roller-like rotating body having conductivity which is integrally molded of metal, is opposed to the developer carrying body 20 in a non-contact manner, and is rotationally driven under a predetermined condition. . On the other hand, the conveying member 41 shown in FIG. 4 is a shaft formed of metal, on the outer periphery of which a cylindrical foam member made of urethane foam is formed, and has an electric resistance of 1 ×.
The conductive material having a conductivity of 10 ⁶ Ω is brought into contact with the developer carrying member 20 so as to be opposed thereto, and is rotationally driven under a predetermined condition.

Further, the transport members 40 and 41 are electrically biased to the developer carrier 20 by the peeling bias applying means 46 and have a polarity (0 to +500 V) opposite to that of the developer 10 which is negatively charged. The respective undeveloped developers remaining on the developer carrying member 20 are peeled off on the transport members 40 and 41, respectively.

Further, the conveying member 40 has a scraping member 4 for scraping off the peeled developer from the conveying member 40.
8 is provided. The scraping member 48 is one in which one end of an insulating PET film of 100 μm is pressed against the conveying member 40 in the counter direction, and mechanically scrapes the developer adhering to the conveying member 40 to allow it to flow. It is sent to the developer storage space 62.

The partition members 50 and 51 are plate-shaped members made of resin, and the closest portion of one end thereof is the developing carrier 2.
It is close to 0 with a gap of 0.5 mm. Further, the partition members 50 and 51 respectively connect the tangent line α passing through the closest point existing on the outer peripheral surface of the developer carrying member 20 and the closest contact point at the closest position facing the developer carrying member 20. Tangent line β with passing partition members 50 and 51
The developer advancing angle θ formed by and is formed in a wedge shape of 45 degrees.

Table 1 shows the arrangement conditions of the transport member and the partition member.

[0072]

[Table 1]

With respect to the developer storage spaces 62 and 62 (b), when the radius of the circle inscribed in the transport members 40 and 41, the partition members 50 and 51 and the developer carrier 20 is r (cm), at least r A volume that can satisfy the relationship of ≧ 3.35 × 10 ^-2 L ^1/2 is required. Assuming that the maximum image forming width of each of the developing devices 11 and 12 is L = 20 (cm), the circle radius r inscribed in the conveying members 40 and 41, the partitioning members 50 and 51, and the developer carrying member 20 is r ≧ Since 0.15 (cm) is derived, in the present developing devices 11 and 12, the developer storage spaces 62 and 62 (b) are configured by setting the inscribed circle radius r to r = 0.25 (cm), respectively. did.

The agitating member 70 disposed in the developer collecting spaces 63 and 63 (b) is composed of a shaft portion and a blade portion which are integrally molded with resin, and the tip of the rotation orbit of the blade portion is the developer carrier 20. With a distance d1 = 4 (mm) from, the peripheral speed ratio with respect to the developer carrying member 20 was set to 0.1 and rotationally driven so that the portion facing the developer carrying member 20 moved in the same direction.

The developer replenishing space of the present developing device, the developer storing space for storing the developer charged by the regulating member, and the absolute value q1 of the specific charge amount of the developer remaining in the developer collecting space,
The values shown in Table 2 were obtained when q2 and q3 were respectively determined by the charge amount measurement method by the suction method. However, prior to the measurement, the developer carrying member and the conveying member were operated for 30 seconds in a state where the developer was not transferred onto the latent image carrying member to stabilize the charged state of the developer in each space. (The charge polarity of the developer is negative)

[0076]

[Table 2]

The seal member 27 is an insulating polyethylene film having a thickness of 500 μm, one end of which is fixed to the housing of the developing device and the other end of which is closely arranged in abdominal contact with the developer carrying member 20.

Using the developing devices 11 and 12 having the above-mentioned configuration, a print pattern including a grayscale image, a line image, a solid image and a character image having a resolution of 600 DPI was continuously formed on 5000 sheets.
The PI dot image and the line image were stably formed without thickening the image, and a high-resolution image excellent in area gradation could be formed. Further, it was possible to form a clear character image without ghost (so-called afterimage or development memory) and background fog, and to stably form a high-density solid image with an OD value of 1.4 or more without density unevenness. Further, no increase in driving torque of the developer carrying member or fluctuations in rotation speed were observed, and images without image jitter could be continuously formed. No toner adhesion or fusion state was observed on the developer carrier or the regulating member, and no toner damage was observed.

[Embodiment 2] FIGS. 5 to 7 are schematic views of the developing devices 13, 14 and 15 in the embodiment of the present invention, showing examples in which the shapes of partitioning members are different from each other.

The developer carrying member 21 is a roller-like rotating body having conductivity which is integrally molded of metal, and has a surface roughness Rz (JIS 10-point average surface roughness) of 2 μm.
Then, the developer 1 is electrically biased to the latent image carrier 1 by the bias applying means 26 to be negatively charged.
A potential of the same polarity (−100 to −500 V) as 0 is applied.
The regulating member 30 has the same structure as that used in the first embodiment.

The carrying member 40 is a roller-like rotating member made of a conductor integrally molded of metal, and is a developer carrying member 21.
Are opposed to each other with no contact (gap of 300 μm), and are rotationally driven at a peripheral speed ratio of 1 so as to move in the same direction at the facing position. Further, the carrying member 40 is electrically biased to the developer carrying member 21 by the peeling bias applying means 46, and has a polarity (0 to ++) opposite to that of the developer which is negatively charged.
The developer carrying member 21 is supplied with a potential of 500 V).
The residual developer remaining on the developer is peeled off on the transport member 40. Further, the carrying member 21 has a scraping member 48 for scraping the peeled developer from the carrying member 40.
(C) and 48 (d) and 48 (e) are arranged, respectively. The scraping members 48 (c) and 48 (d) and 4
8 (e) is one in which one end of an insulating PET film having a thickness of 100 μm is pressed against the conveying member 40 in the counter direction, and the developer adhered on the conveying member 40 is mechanically scraped to self-flow. While being fed, they are sent into the developer storage spaces 62 (c) and 62 (d) and 62 (e), respectively.

The partition member 52 shown in FIG. 5 is a block-shaped member made of resin, one end of which is the developer carrying member 2.
1 with a gap of r = 0.8 (mm), and at the closest position facing the developer carrying member 21,
The developer advancing angle θ formed by a tangent line α passing through the closest contact point existing on the outer peripheral surface of the developer carrying member 21 and a tangent line β with the partition member 52 passing through the closest contact point has a wedge shape of 60 degrees. I arranged it.

The partition member 53 shown in FIG. 6 is a plate-shaped member made of resin, and one end of the partition member 53 is the development carrier 21.
With a gap of r = 0.5 (mm),
The developer was arranged in a wedge shape having an approach angle θ of 45 degrees.

Further, the partition member 54 shown in FIG. 7 is a roller-shaped rotating body having conductivity which is integrally molded of metal and has a gap of r = 0.3 (mm) with respect to the developer carrying body 21. And are made to face each other, and the developer carrying member 21 is placed at the facing position.
The peripheral speed ratio is 1 so that the developer moves in the same direction as
Was rotated at 30 degrees. Table 3 shows the arrangement conditions of the partition members described above.

[0085]

[Table 3]

The partitioning member 54 is electrically biased to the developer carrying member 21 by the separation bias applying means 56, and has the same polarity (0) as the developer charged negatively.
The potential of (-500 V) is applied to separate the positively charged developer from the developer carrier 21 onto the partition member 54. Further, a cleaning member 55 for removing the developer adhering to the surface of the partition member is disposed on the partition member 54. Cleaning member 5
5 is one in which one end of an insulating PET film of 100 μm is pressed against the partition member 54 in the counter direction,
The developer adhering to the partition member 54 is mechanically scraped, and sent into the developer collecting space 63 (e) while self-flowing.

Developer storage spaces 62 (c) and 62 (d)
And 62 (e), the conveying member 40 and the partitioning member 5
When the radii of the circles inscribed in 2 and 53 and 54 and the developer carrying member 21 are r (cm), respectively, the volume that can satisfy at least the relationship of r ≧ 3.35 × 10 ⁻² L ^1/2 is is necessary. Assuming that the maximum image forming width of each of the developing devices 13 and 14 and 15 is L = 20 (cm), the circle radius r inscribed in the conveying member 40, the partitioning members 52 and 53 and 54, and the developer carrier 21 is Since r ≧ 0.15 (cm) is derived, in the developing device 13 shown in FIG. 5, r = 0.2 (cm),
In the developing device 14 shown in FIG. 6, r = 0.5 (cm),
In the developing device 15 shown in, the developer storage space is configured by setting r = 0.15 (cm).

Further, in the developing devices 14 and 15 shown in FIGS. 6 and 7, the developer collecting spaces 63 (c) and 63
The stirring member 70 arranged in (d) is composed of a shaft portion and a blade portion integrally molded of resin, and the tip of the rotation trajectory of the blade portion is a distance d1 = 4 (m) from the outer periphery of the developer carrying member 21.
m), the peripheral speed ratio with respect to the developer carrying member 21 is set to 0.1 so as to move in the same direction at a position facing the developer carrying member.
To rotate. On the other hand, in the developing device 13 shown in FIG. 5, the developer collecting space 63 is provided by disposing the regulating member 30 above the rotation center axis of the developer carrier 21.
The arrangement of the stirring member in (c) is unnecessary.

Developing devices 13 and 1 shown in FIGS.
4, the second stirring member 75 is composed of a shaft portion and a blade portion that are integrally molded with resin, and is provided with a developer replenishing space 61.
(C) and 61 (d), and the developers in the developer replenishing spaces 61 (c) and 61 (d) are moved to the developer storage spaces 62 (c) and 62 (d), respectively. It can be driven to rotate. On the other hand, in the developing device 15 shown in FIG. 7, the vertical configuration eliminates the need for disposing the second stirring member in the developer replenishing space 61 (e).

The developer replenishing space of the present developing device, the developer storing space for storing the developer charged by the regulating member, and the absolute value q1 of the specific charge amount of the developer remaining in the developer collecting space,
When q2 and q3 were respectively determined by the charge amount measurement method by the suction method, the results shown in Table 4 were obtained. However, prior to the measurement, the developer carrying member and the conveying member were operated for 30 seconds in a state where the developer was not transferred onto the latent image carrying member to stabilize the charged state of the developer in each space. (The charge polarity of the developer is negative)

[0091]

[Table 4]

The sealing member 27 is an insulating polyethylene film having a thickness of 500 μm, one end of which is fixed to the housing of the developing device and the other end of which is closely arranged in abdominal contact with the developer carrying member 20.

The developing devices 13 and 14 and 1 having the above structure
5, a print pattern including a grayscale image having a resolution of 600 DPI, a line image, a solid image, and a character image was continuously formed on 5000 sheets,
An excellent image as obtained in Example 1 could be formed. Further, no increase in driving torque of the developer carrying member or fluctuations in rotation speed were observed, and images without image jitter could be continuously formed. No toner adhesion or fusion state was observed on the developer carrier or the regulating member, and no toner damage was observed.

Although the embodiments have been described above, the present invention can be widely applied not only to the above embodiments but also to developing devices for electrophotography and the like, and especially when applied to printers, copying machines, facsimiles and displays. It is valid.

[0095]

As described above, according to the configuration of the first aspect of the present invention, the partition member is located at the position where the regulating member and the developer carrying member face each other in the moving direction of the developer carrying member. Is also disposed on the upstream side as the limit line of the downstream section of the developer storage space, so the developer separated from the developer carrier is temporarily blocked and the developer carrier is fully charged. Developer can be supplied. Therefore, in the developing device of the present invention, it is not necessary to add a mechanism for precharging the developer, and a drive load for operating the mechanism is not required. Therefore, the mechanism of the developing device can be simplified and downsized. And a developing device capable of low torque driving. Further, in the above-described developing device, the transport member always separates the developer remaining on the developer carrying member after the development from the developer carrying member to prevent the developer on the developer carrying member after being regulated by the regulating member. Since the history of the developed image pattern is not retained, it is possible to provide a developing device that does not cause ghost (so-called afterimage or developing memory). Further, since the developer remaining on the developer carrying member is constantly separated, the stress on the developer on the developer carrying member is minimized and the developer is fixed to the developer carrying member or the regulating member (so-called developer. The developing device can prevent the filming phenomenon.

According to the second aspect of the invention, the maximum image forming width of the developing device is L (cm), and the radius of the circle inscribed in the conveying member, the partitioning member and the developer carrying member is r (c).
m), the relation of r ≧ 3.35 × 10 ⁻² L ^1/2 is satisfied, and the cylindrical volume consisting of the inscribed circle radius r and the maximum image forming width L is defined in the developer storage space. In the case where the developer storage space is capable of storing a required minimum amount of charged developer or more and the image pattern formed in a high temperature and high humidity environment is a solid image of high density over the entire area. In addition, the developing device can form a uniform solid image without insufficient density.

According to the third aspect of the invention, the peeling bias applying means for forming an electric field in a predetermined direction is provided between the conveying member and the developer carrying member. Therefore, only the developer charged with a predetermined polarity can be peeled off and conveyed and stored in the developer storage space.
Since the charged developer having a uniform charging polarity is supplied onto the developer carrier, the regulating member does not need to charge the developer on the developer carrier with a large load, and thus it is possible to reduce the layer thickness. A uniform thin layer of developer can be formed with the minimum required load. Therefore, the frictional force generated between the restricting member and the pressing portion of the developer carrying member is reduced, the torque load for driving the developing device is reduced, and the phenomenon that the developer is fixed to the developer carrying member and the restricting member is prevented. It can be a developing device.

According to the fourth aspect of the invention, since the scraping member for scraping the developer is provided on the carrying member, the charged developer is scraped from the carrying member to store the developer. Since the developer self-flows in one direction in the space, the developer can be efficiently stored in the developer storage space. Therefore, in the above configuration, the charged developer can be stored only in the developer storage space without being discharged to a space other than the desired space, so that the time for storing the charged developer can be set to be short and continuous image formation can be performed. The non-image forming section (non-passage distance of recording paper) can be shortened.

According to the fifth aspect of the present invention, at the closest position where the partition member and the developer carrying member face each other, a tangent line passing through the closest contact existing on the outer peripheral surface of the developer carrying member, When the tangent to the partitioning member passing through the closest contact point and the developer advancing angle formed by θ are degrees, θ ≦
It satisfies the 90 ° relationship. By forming the developer formed by the partition member and the developer carrier into a wedge shape with an entrance angle of 90 ° or less, the developer densely packed on the developer carrier can be supplied, and the developer can be easily adjusted in the regulation section. A uniform thin developer layer with no layer thickness unevenness is formed. Therefore, it is possible to provide a developing device that does not cause density unevenness without providing a complicated developer supply mechanism inside the developing device.

According to the sixth aspect of the present invention, since the separating bias applying means for forming an electric field in a predetermined direction is provided between the partition member and the developer carrying member, the developing agent is provided. From the charged developer supplied on the carrier, only the developer charged to the opposite polarity is separated from the developer carrier, and the developer carrier is charged at the position where the regulation member and the developer carrier face each other. A developer having uniform polarity can be supplied.
Therefore, the developer can set the restriction load of the restriction member to be small, and at the same time, the development device can reduce the background fog (deposition of the developer to the non-image portion).

According to the structure of claim 7 of the present invention, since the partition member is a rotating body, the rotating body is separated from the developer carrying body and the developer charged to the opposite polarity is charged. And is sequentially discharged while being rotationally moved to the developer recovery space. The developer charged to the opposite polarity is efficiently released to the developer recovery space, and thus is prevented from being remixed in the developer on the developer carrier. Therefore, the developer on the developer carrying member, which has a predetermined charge polarity, is conveyed to the latent image carrying member, so that the developing device with a reduced background fog amount can be obtained.

According to the eighth aspect of the present invention, since the cleaning member for removing the developer is provided on the rotary member, the developer attached to the rotary member is removed by the cleaning member. The developer is discharged in one direction to accelerate the self-flow of the developer in the developer recovery space. Further, by constantly cleaning the rotating body with the cleaning member, it is possible to prevent the efficiency of separating the oppositely charged developer on the developer carrier from being lowered. Therefore, the developer in the developer collecting space is promoted to flow back to the developer replenishing space and the developer storing space, so that the developer is prevented from solidifying, and the developer having a predetermined charge polarity is prepared. The developing device can be carried on the latent image carrier to reduce the amount of background fog.

According to a ninth aspect of the present invention, the carrying member and the developer carrying member are opposed to each other and the rotating member and the developer carrying member are opposed to each other. The moving direction of the rotating body is the same as the moving direction of the developer carrying body. By making the conveying member and the developer carrying member move in the same direction, the developer can be efficiently separated when the conveying member separates and conveys the developer remaining on the developer carrying member. Therefore, the developer can be easily released into the storage space. Further, by making the rotating body and the developer carrying member move in the same direction, the oppositely charged developer is efficiently separated when the rotating member separates the oppositely charged developer from the developer carrying member. Therefore, the developer can be easily released into the space. Therefore, in the above configuration, it becomes easy to store the charged developer and release the oppositely charged developer,
The time for storing the charged developer can be set to be short, and the developing device can have a short non-image forming section during continuous image formation.

Further, according to the structure of the tenth aspect, the agitating member is the partition member, the developer carrier on the downstream side in the moving direction of the developer carrier from the position where the partition member is disposed, and the regulating member. By agitating the excess supply of developer that accumulates in the developer recovery space surrounded by and, it promotes the return to the developer replenishment space or developer storage space, and prevents the developer from stagnating in the developing device. can do. Therefore, in the above-described developing device, the excessive supply of developer accumulated in the developer recovery space is positively recirculated, so that the pressing force of the regulating member against the developing carrier is substantially weakened by the accumulated powder pressure of the developer. And the solidification (blocking) phenomenon of the developer that occurs due to the compression of the accumulated developer is prevented, and the fluctuation of the image density during the developing operation and the fluctuation of the background fog, and the development under the high temperature and high humidity environment It is possible to provide a developing device that does not cause troubles due to solidification of the agent.

Further, according to the structure of claim 11,
When the gap between the outer peripheral surface of the developer carrier and the outer peripheral rotation orbit of the stirring member is d1 (mm), the relationship of d1 ≧ 1 is satisfied, so that the stirring member moves to recover the developer. When the developer in the space moves, the gap between the outer peripheral surface of the developer carrier and the outer peripheral rotation orbit of the stirring member is set to 1 (mm) or more, so that the developer in the developer recovery space and the developer The developer on the carrier is prevented from interfering with each other and mixed, and the developer on the developer carrier is prevented from being scraped off by the stirring member. Therefore, in the above-mentioned configuration, the stirring member does not depend on the shape and the moving speed of the blade member with respect to the developer layer supplied on the developer carrier, and the periodic traces of the stirring member (image density and background). It is possible to provide a developing device in which the solidification of the developer is prevented without forming an unevenness such as a fog on the image.

Therefore, according to the developing device of the present invention,
It is possible to provide a developing device that is small in size and capable of low torque drive without causing image defects such as ghost and image density unevenness.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an image forming apparatus showing an embodiment of the present invention.

FIG. 2 is a schematic view of a developing device showing an embodiment of the present invention.

FIG. 3 is a diagram showing a section of a developer remaining in a sectioned space in a developing device according to an embodiment of the present invention.

FIG. 4 is a schematic view of a developing device showing another embodiment of the present invention.

FIG. 5 is a schematic view of a developing device showing still another embodiment of the present invention.

FIG. 6 is a schematic view of a developing device showing still another embodiment of the present invention.

FIG. 7 is a schematic view of a developing device showing still another embodiment of the present invention.

FIG. 8 is a diagram showing a developer advancing angle at a facing portion between a partition member and a developer carrier in the developing device of the present invention.

FIG. 9 is a diagram showing a configuration of a developer storage space in the developing device of the present invention.

[Explanation of symbols]

 1 latent image carrier 10 developer 11 12 13 14 15 developing device 20 21 developer carrier 26 bias applying means 30 regulating member 40 41 conveying member 48 scraping member 46 peeling bias applying means 50 51 52 53 54 partitioning member 55 cleaning Member 56 Separation bias applying unit 62 Developer storage space 63 Developer recovery space 70 Stirring member

Claims (11)

[Claims] 1. A developer carrying member carrying and carrying a developer, and a developing device for visualizing a latent image of a latent image carrying member by the developer on the developer carrying member, comprising: And a transport member arranged downstream of the developer carrying member and the latent image carrying member in the moving direction of the developer carrying member, and a developer carrying member. A partition member disposed downstream of the position where the body and the transport member face each other in the moving direction of the developer carrier, and the developer storage space is configured by the transport member, the partition member, and the developer carrier. A developing device characterized in that 2. The maximum image forming width of the developing device is L (c
2. The developing device according to claim 1, wherein the following relation is satisfied, where r (cm) is a radius of a circle inscribed in the developer carrying member, the carrying member, the partitioning member and the developer carrying member. r ≧ 3.35 × 10 ^-2 L ^1/2 3. The developing device according to claim 3, further comprising a peeling bias applying unit that forms an electric field in a predetermined direction between the conveying member and the developer carrying member. 4. The developing device according to claim 1, further comprising a scraping member that scrapes off the developer on the conveying member. 5. A tangent line passing through the closest contact existing on the outer peripheral surface of the developer carrying member at a closest position where the partition member faces the developer carrying member, and a partition member passing through the closest contact point. Θ (degrees) of the developer advancing angle formed by the tangent of
2. The developing device according to claim 1, wherein the relationship of θ ≦ 90 ° is satisfied. 6. The developing device according to claim 1, further comprising a separating bias applying unit that forms an electric field in a predetermined direction between the partition member and the developer carrying member. 7. The developing device according to claim 6, wherein the partition member is a rotating body. 8. The developing device according to claim 7, wherein a cleaning member for removing the developer is provided on the rotating body. 9. The moving direction of the carrying member and the rotating body is the developer carrying body at a position where the carrying member and the developer carrying body face each other and a position where the rotating body and the developer carrying body face each other. 8. The developing device according to claim 7, wherein the developing device is in the same direction as the moving direction of the developing device. 10. Enclosed by at least the partition member, the developer carrying body on the downstream side in the moving direction of the developer carrying body from the position where the partition member faces the developer carrying body, and a regulating member. The developing device according to claim 1, wherein a stirring member is provided in the developer collecting space. 11. The relationship of d1 ≧ 1 is satisfied, where d1 (mm) is the gap between the outer peripheral surface of the developer carrying member and the outer peripheral rotation orbit of the stirring member.
No. 0 developing device.