KR20140074820A - Developing device, process cartridge including developing device, and image forming device including developing device - Google Patents

Abstract

In order to provide a developing device capable of realizing ease of assembly while satisfactorily maintaining the charging property of the developer, the developing device includes a developing roller, a toner supplying roller which moves in the opposite direction in the contact area with the developing roller, And the developer regulating member. Wherein the height difference between the convex portion and the concave portion of the developing roller is 0.8 times or more and 5.0 times or less as large as the weight average particle diameter of the developer and the imaginary whole circumferential surface , The ratio of the total area of the top surface of the convex portion with respect to the area of the entire peripheral surface is 3% or more and less than 40%, and the contact position of the developing roller and the regulating member is lower than the contact position of the developing roller and the toner supplying roller , And surplus developer regulated by the regulating member is collected in the toner storage portion provided below the developing chamber.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a developing device, a process cartridge, and an image forming apparatus. BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a developing apparatus, a process cartridge, and an image forming apparatus used in an electrophotographic image forming apparatus, particularly, a developing apparatus having a convex portion and a concave portion arranged on a surface thereof, And an image forming apparatus.

The image forming apparatus forms an image on a recording material (recording medium) by using an electrophotographic image forming system, and includes at least a copying machine, a printer, a facsimile machine, a word processor, and a multifunctional printer (multifunction printer). The developing apparatus is an apparatus for visualizing an electrostatic image on an image carrier such as an electrophotographic photosensitive member using a developer. The process cartridge is configured such that the electrophotographic photosensitive member and developing means as at least a process means acting on the electrophotographic photosensitive member are integrally made into a cartridge and detachable from the main body of the image forming apparatus.

In an image forming apparatus using an electrophotographic system, an electrostatic latent image is formed by selectively exposing the outer circumferential surface of a photoconductive drum as an electrophotographic photosensitive member which is normally charged, and the electrostatic latent image is transferred onto a developer As a toner image. Then, the toner image formed on the photosensitive drum is transferred to the recording material, and the toner image transferred onto the recording material is further subjected to heat or pressure to fix the toner image on the recording material.

In such an image forming apparatus, it is necessary to improve the chargeability of the toner in order to stably form a high-precision image. For example, by using a developer bearing roller having regularly arranged convex portions and concave portions on its surface, (See Japanese Patent Application Laid-Open No. 2001-3258).

In this developing apparatus, a developer regulating member is used to regulate the layer thickness of the toner carried on the developer carrying roller, and the toner carried on the surface of the developer carrying roller is conveyed by the plane of the developer regulating member The developer is pressed against the surface of the developer carrying roller or the developer regulating member, so that a good charging state can be obtained.

However, as a result of intensive investigation by the present inventors, it has been found that a slight difference in the contact condition of the developer regulating member, when using a developer bearing roller having a convex portion and a concave portion on its surface, (Hereinafter referred to as " developer regulated amount ").

As an example, Fig. 1 shows the relationship of the developer regulating amount on the developer carrying member to the amount of protrusion of the developer regulating member.

Here, the amount of protrusion of the developer regulating member (hereinafter referred to as " protrusion amount ") is one of the contact conditions of the developer regulating member. In the present invention, (Refer to FIG. 3, detailed description will be given later).

The regulating amount of the developer increases as the amount of protrusion increases. Since the surface regulating amount of the developer is influenced by the surface shape of the developer carrying member, the point of curvature A and the point of curvature B are generated.

In the region where the amount of protrusion is small (region (a) in FIG. 1), most of the developer is contained in the concave portion (see FIG. 2 (a)), so that good charging characteristics can be obtained. However, Is not. When the amount of protrusion becomes larger, the filling of the developer with the concave portion is terminated, and as a result, the inflection point A is generated. After the bending point A (region (b) in FIG. 1) is filled with the concave portion, some developer overflows at the top of the convex portion (refer to FIG. 2 (b)). (C) of Fig. 1), a developer layer which has not entered the concave portion forms one or more developer layers on the top surface of the convex portion (see Fig. 2 (c)), Adversely affecting the characteristics.

In other words, it is difficult to secure the amount of the developer necessary for image formation in the region (region (a) in FIG. 1) until the bending point A is generated, ), The characteristics of the developer bearing roller as described above are lost, and various defects such as image formation are caused.

Therefore, in order to exhibit the performance of the developer carrying member in which the convex portion and the concave portion are arranged on the surface, the amount of protrusion of the developer regulating member in the region from the bending point A to the bending point B (region (b) It was necessary to adjust and maintain the state.

However, in the region from the bending point A to the bending point B, since the rate of change (corresponding to the linear gradient in Fig. 1) of the regulated amount of the developer to the amount of protrusion is very large, (The range of the upper limit value to the lower limit value) of the protruding amount (center value) with respect to the protruding amount (the range of the lower limit value) is very narrow.

In addition, even in the case of the developing device having completed the adjustment, since the surface of the developer regulating member and the developer carrying member is worn away, the developer regulating amount is liable to fluctuate, so that it becomes difficult to control the image density and color balance, It was not suitable for the developing apparatus of the apparatus.

Further, when the above-described developing apparatus is mounted on a process cartridge having a relatively small opportunity for image formation, it is difficult to cope with twisting or distortion of the developing apparatus portion due to external power for driving the developing apparatus at the time of image formation, A difference in image brightness or color unevenness occurs in the page, and thus the image has not yet been put to practical use.

On the other hand, as a technique for developing with toner, for example, it is known that it is described in Patent Document 2. The developing device described in Patent Document 2 is provided with a developing roller having a cylindrical or cylindrical shape and having a concavo-convex portion for supporting toner on the outer peripheral surface thereof. The developing roller is provided with a plurality of concave portions extending in a direction inclined by 45 degrees with respect to the rotation direction of the developing roller and a plurality of concave portions extending in a direction inclining 45 degrees in the direction opposite to the concave portion with respect to the rotational direction have. Many of these concave portions are formed so as to intersect with each other, thereby forming a plurality of rhomboidal convex portions as shown in Fig. 20 (see Patent Document 2)

However, the convex-and-concave portion of the surface of the developing roller as described above has a configuration in which the cross-sectional area of the concave portion varies in accordance with the rotational position. Specifically, as shown in Fig. 20, the width of the concave portion of the A-A cross-section is different from the width of the concave portion of the B-B cross-section. When the width of the concave portion is deviated in this manner, the charged amount of the toner varies depending on the rotational position of the developing roller. When the charged amount of the toner is varied, an image in which the density is uneven is generated, which becomes a factor of deteriorating the image.

Further, in the above-described developing roller, there is a problem that the toner stagnates at the intersection of the concave portion extending in the direction inclining 45 degrees with the rotation direction and the concave portion extending in the direction inclining 45 degrees in the opposite direction. Specifically, as shown in Fig. 20, the toner tends to stagnate at the apex X of the convex portion. When the toner stagnates in this manner, the region of the stagnant toner at the apex X is diffused, There is a concern. Further, the surface of the developing roller may become dirty or the toner may scatter due to the stagnation of the toner.

Further, when the toner stagnates on the surface of the developing roller, toner adheres to the toner, resulting in defective conveyance of the toner. As a result, there arises a problem that the image is streaked or the density fluctuates. Further, if the toner stagnates on the surface of the roller, the remaining toner after development becomes difficult to be recovered by the toner recovery means, and a problem of charging failure occurs when new toner is supplied.

(Patent Document 1) Japanese Patent Laid-Open No. 2007-121947

(Patent Document 2) Japanese Patent No. 4618303

According to one embodiment of the present invention, by optimizing the configuration of the developing apparatus, the charging state of the developer is controlled by controlling the developer carrying state on the developer carrying roller in which convex portions and concave portions are arranged on the surface, A process cartridge, and an image forming apparatus, which facilitates mounting and adjustment of the regulating member so as to facilitate assembly at a mass production level.

Also, there is provided a developing apparatus, a process cartridge, and an image forming apparatus which are difficult to cause variations in image density and color balance due to wear of the developer regulating member and the surface of the developer carrying member even when image formation is repeated a plurality of times The purpose.

Another object of the present invention is to provide a developing apparatus, a process cartridge, and an image forming apparatus capable of minimizing variations in image density and color balance even when subjected to a deformation stress from the outside.

According to another embodiment of the present invention, there is provided a developing device, a process cartridge, and an image forming apparatus, which prevent toner from stagnating on the surface of the developing roller and improve image quality.

In order to achieve the above object, a developing apparatus according to an embodiment of the present invention includes: a developer accommodating chamber for accommodating a developer; a developing chamber disposed adjacent to the developer accommodating chamber; A partition wall having an opening for connecting the developer containing chamber and the developing chamber, a developer carrying member rotatably disposed for carrying and conveying the developer in the developing chamber, A developer supply member which is disposed in the developer carrying member and supplies the developer supplied through the opening to the developer carrying member; And a developer regulating member for regulating the layer thickness of the supplied developer, wherein the developer supplying member is provided so as to be in contact with the peripheral surface of the developer carrying member A plurality of protrusions arranged to bear the developer on the developer carrying member, and a plurality of protrusions arranged on the developer carrying member for surrounding the plurality of protrusions, Wherein a height difference between a top surface of the convex portion and a bottom surface of the concave portion is 0.8 times or more and less than 5.0 times the weight average particle diameter (D4) of the developer, Wherein a ratio of the total area of the top surface of the convex portion to the total area of the circumferential surface is 3% or more and less than 40% when the virtual total circumferential surface obtained by extending the top surface of the convex portion in the axial direction and the circumferential direction is defined And the contact position of the developer carrying member and the developer regulating member is below the contact position of the developer carrying member and the developer carrying member And is, to the developer carrying member, surplus developer regulated by said developer regulating member from the first characterized in that for recovering from a developer storage portion arranged at the bottom of the developing chamber.

As described above, according to the embodiment of the present invention, the surplus developer regulated by the developer regulating member from the surface of the developer carrying member is not directly recovered to the developer storage chamber, but is stored in the developer storage portion provided below the development chamber Recall. Since the surplus developer recovered in the developer storage portion is already adequately charged, it is subjected to gentle compression in the space between the contact position of the developer carrying member and the partition wall forming the developer storage portion It is possible to maintain a gentle compaction state by electrostatic repulsion between the developers while easily penetrating into the concave portion of the surface of the developer carrying member.

The contact position of the developer carrying member and the developer regulating member may be located below the contact position of the developer carrying member and the developer supplying member (between the partition wall forming the developer storing member and the developer carrying member, Between the contact positions of the developer supply member), the circulation pressure of the developer relative to the respective contact positions can be made uniform and gentle, so that the penetration into the concave portion of the surface of the developer carrying member is further stabilized , The degree of freedom of the contact condition (protrusion amount) between the developer carrying member and the developer regulating member can be increased.

A developing device according to another embodiment of the present invention includes: a developing roller having a concavo-convex portion on its surface, the convexoconcave portion being provided with a developing roller for charging toner, a toner supplying portion for supplying toner to the developing roller, And a developer regulating member for regulating the amount of toner to be charged. The concave portion of the surface of the developing roller has a first concave portion extending in a direction inclined with respect to the rotation direction of the developing roller and a second concave portion extending in a direction different from a direction in which the rotational direction or the first concave portion extends, And a third concave portion continuous to the concave portion and the second concave portion and extending in the rotational direction.

In this developing apparatus, a third concave portion continuously extending from the first concave portion and the second concave portion and extending in the rotational direction is provided as a concave portion on the surface of the developing roller. By having the third concave portion extending in the rotational direction in this way, the fluctuation of the width of the concave portion corresponding to the rotational position is reduced, and thus deviation of the charged amount of the toner and fluctuation in the density of the image can be prevented. Further, by having the third concave portion extending in the rotating direction, the toner is liable to move in the rotating direction, so that stagnation of the toner is suppressed. Therefore, the problem of stagnation of the toner does not occur, and the quality of the image can be improved.

If the width of the developing roller in the first concave portion in the direction of the axis of rotation is a, the width of the second concave portion in the direction of the axis of rotation is b, and the width of the third concave portion in the direction of the axis of rotation is c, 0.7 = c / 1.4 is satisfied. In this case, since the inclined sheet is close to the sum of the widths of the first concave portion and the second concave portion and the width of the third concave portion extending in the rotating direction, the toner filling amount to the concave portion according to the rotational position can be made uniform. Further, when the values of a, b, and c satisfy 0.9 = c / (a + b) = 1.2, the sum of the widths of the first recess and the second recess and the width of the third recess are closer to each other , The toner charging amount can be made more uniform, and the quality of the image can be further improved.

The sum of the width of the first concave portion and the width of the second concave portion when the developing roller is cut in the direction of the rotation axis of the developing roller may substantially coincide with the width of the third concave portion in the case of cutting in the rotational axis direction. In this case, even when the rotational position of the developing roller changes, there is no fluctuation in the amount of the toner filled in the concave portion, the occurrence of the deviation of the density can be more reliably prevented and the quality of the image can be further improved.

If the depth of the concave portion on the surface of the developing roller is h and the average particle diameter of the toner is d, d <h <3d may be satisfied. In this case, the number of the toner to be filled in the concave portion becomes less than 3, and since the concave portion is not made too deep, the fixing of the toner hardly occurs, so that the occurrence of filing can be prevented, Can increase.

Further, the image forming apparatus may further include a photoreceptor drum that receives toner from the developing roller, and the rotational speed of the developing roller may be 1.0 times or more and 3.0 times or less the rotational speed of the photoconductor drum. In this case, too, it is difficult for the toner to stick, so that the occurrence of filming can be prevented and the lifetime of the developing apparatus can be increased.

According to an embodiment of the present invention, it is possible to provide a developing device, a process cartridge and an image forming apparatus which are easy to assemble and have excellent mass productivity, while allowing good image formation by expressing / maintaining good charging characteristics of the developer have. Further, even in the case where image formation is repeated a plurality of times, it is possible to provide a developing apparatus, a process cartridge and an image forming apparatus which are less liable to cause variations in image density and color balance due to surface abrasion of the developer amount regulating member and the developer carrying member have. Also, it is possible to provide a developing apparatus, a process cartridge, and an image forming apparatus which are less liable to cause variations in image density and color balance even when subjected to a strained stress from the outside.

According to another embodiment of the present invention, there can be provided a developing apparatus, a process cartridge, and an image forming apparatus capable of preventing the toner from stagnating on the surface of the developing roller and improving the quality of the image.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing the relationship between the amount of developer regulating on the developer carrying member and the amount of protrusion of the developer regulating member in a developing apparatus (conventional example) provided with a developer carrying member having regularly arranged convex portions and concave portions on its surface Fig.
Fig. 2 is a partially enlarged photograph showing a regulation state of a developer (toner) carried on the surface of a developer carrying member having regularly arranged convex portions and concave portions on its surface.
3 is a view for explaining the amount of protrusion of the developer regulating member.
Fig. 4 is a diagram showing a schematic configuration of a one-component developing unit according to Embodiment 1. Fig.
5 is a view showing a schematic configuration of a developer carrying member according to an embodiment of the present invention.
6 is a view for explaining a top surface of a convex portion disposed on the developer carrying member;
7 is a view for explaining a top surface in the case where the shape of the convex portion arranged on the developer carrying member is different.
Fig. 8 is a view showing a schematic configuration of a one-component developing unit according to Comparative Examples 2 and 3. Fig.
9 is a view showing a schematic configuration of a one-component developing unit according to Comparative Example 4. Fig.
10 is a diagram showing a schematic configuration of a one-component developing unit according to Comparative Example 5. Fig.
11 is a view showing the relationship of the developer regulating amount on the developer carrying member to the amount of protrusion of the developer regulating member in Example 1. Fig.
12 is a view showing the relationship of the developer regulating amount on the developer carrying member to the amount of protrusion of the developer regulating member in Comparative Example 2. Fig.
13 is a schematic configuration diagram of a developing apparatus according to an embodiment of the present invention.
14 is a side view showing the developing roller of the developing apparatus of Fig.
15 is a partially enlarged view of the surface of the developing roller in Fig.
16 is a graph showing the relationship between the amount of toner on the developing roller and the number of prints.
17 is a graph showing the relationship between the widths of the first to third concave portions and the occurrence time of toner fixing.
18 is a graph showing the relationship between the depth of the concave portion and the fog density of the toner.
19 is a graph showing the relationship between the widths of the first to third concave portions and the toner fixation occurrence time.
20 is an enlarged view of the surface of a conventional developing roller.

 Hereinafter, a preferred embodiment of the present invention will be described in detail by way of example. It should be noted that the dimensions, materials, shapes, and relative arrangements of the constituent parts described in this embodiment should be appropriately changed depending on the configuration of the apparatus to which the present invention is applied and various conditions, But the present invention is not limited to the embodiment. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description is omitted.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copier, a printer, a facsimile apparatus, a word processor, and a multifunction printer (multifunction printer) for forming an image on a recording material (recording medium) using an electrophotographic method.

First, an image forming apparatus and an image forming method using the image forming apparatus will be described.

<Image Forming Apparatus and Image Forming Method>

The image forming method according to the present embodiment includes a charging step of applying a voltage to at least a charging member from outside and charging the latent electrostatic image bearing member, a latent image forming step of forming an electrostatic latent image on the charged latent electrostatic image bearing member, Developing the toner image on the latent electrostatic image bearing member to form a toner image on the latent electrostatic image bearing member, a transfer step of transferring the toner image on the latent electrostatic image bearing member to a transfer material, a fixing step of heating and fixing the toner image on the transfer material Process. Further, in addition to the above steps, for example, a cleaning step of removing residual toner such as toner remaining on the surface of the latent electrostatic image bearing member may be further provided.

Hereinafter, an image forming apparatus using the one-component developing method will be described as an example of the image forming apparatus according to the present embodiment.

In the image forming apparatus, around the electrophotographic photosensitive member, there are provided a charging section which is a charging means for charging the surface of the electrophotographic photosensitive member, an exposure section which is a latent image forming means for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image in accordance with image information, A development unit that develops the electrostatic latent image with toner to form a toner image, a transfer unit that is a transfer unit that transfers the toner image formed on the surface of the electrophotographic photosensitive member to the surface of the transfer target, Which is a cleaning means for removing the toner remaining on the surface of the photoreceptor drum.

A fusing unit, which is a fusing unit for fusing the toner image transferred to the subject, is disposed on the side of the transfer path of the transfer subject of the transfer unit.

The operation of the image forming apparatus according to the present embodiment will be described.

First, the surface of the electrophotographic photosensitive member is uniformly charged by the charging section (charging step). Next, the surface of the electrophotographic photosensitive member is irradiated with light by the exposure section, and the electrostatic charge at the portion irradiated with the light is removed, so that an electrostatic charge image (electrostatic latent image) is formed according to the image information (latent image forming step). Thereafter, the electrostatic charge image is developed by the developing portion, and a toner image is formed on the surface of the electrophotographic photosensitive member (developing step).

For example, a digital electrophotographic copying machine using an organophotoreceptor as an electrophotographic photosensitive member and laser beam light as an exposure unit is considered. In this case, the surface of the electrophotographic photosensitive member is given a negative charge by the charging section, a digital latent image is formed in a dot shape by the laser beam light, toner is applied by the developing section to the portion where the laser beam light comes in contact, .

Subsequently, in the transfer portion, a transfer object such as paper is superimposed on the toner image, a charge of a polarity opposite to that of the toner is given to the transfer target from behind the transfer target, and the toner image is transferred to the transfer target by the electrostatic force fair). The transferred toner image is subjected to heat and pressure by a fixing member in a fixing unit, and is fused and fixed to a transfer body (fixing step).

On the other hand, the toner remaining on the surface of the electrophotographic photosensitive member without being transferred is removed from the cleaning portion (cleaning step). One cycle ends with a series of processes from the competition to the cleaning.

The toner image may also be transferred to a transfer body via a transfer member such as an intermediate transfer member.

Hereinafter, the charging means, the latent electrostatic image bearing member, the exposure means, the developing means, the transfer means, the cleaning means, and the fixing means in the image forming apparatus will be described.

[Daejeon]

As the charging unit as the charging unit, for example, a charging unit using a corona discharge, a conductive or semiconductive charging roll, or the like can be used. A contact type charger using a conductive or semiconductive charging roll may apply a direct current to the electrophotographic photosensitive member, or may apply an alternating current in an overlapping manner. By such a charging portion, the surface of the electrophotographic photosensitive member is charged by generating a discharge in a minute space in the vicinity of the contact portion with the electrophotographic photosensitive member. The conductive or semiconductive charging roll may have a single layer structure or a multiple structure. Further, a mechanism for cleaning the surface of the charging roll may be further provided.

[Electrostatic latent image carrier]

The latent electrostatic image bearing member has a function of forming at least a latent image (electrostatic charge image). The electrostatic latent image bearing member is suitably an electrophotographic photosensitive member. The electrophotographic photosensitive member has a coating film containing an organophotoreceptor or the like on the outer circumferential surface of a cylindrical conductive base body. The coating film is formed on the base body in this order, if necessary, with an undercoat layer, a charge generating layer containing a charge generating material, and a charge transport layer containing a charge transporting material. The stacking order of the charge generating layer and the charge transporting layer may be reversed. These are laminated photoconductors in which a charge generating material and a charge transporting material are contained in separate layers (a charge generating layer and a charge transporting layer), and may be a single layer type photoconductor containing both a charge generating material and a charge transporting material in the same layer. Is a stacked photoreceptor. Further, an intermediate layer may be provided between the undercoat layer and the photosensitive layer. In addition, the present invention is not limited to the organic photoconductor, and other types of photosensitive layers such as an amorphous silicon photosensitive film may be used.

[Exposure Means]

The exposure unit, which is an exposure means, is not particularly limited, and for example, an optical system apparatus capable of exposing a light source such as semiconductor laser light, LED light, or liquid crystal shutter light to a desired image on the surface of the latent electrostatic image bearing member.

[Developing Means]

The developing section which is a developing means has at least a developer carrying member, a developer (toner) and a developer regulating member, and if necessary, a developer supplying member or a stirring conveying member for supplying the developer to the developer carrying member. The developer carrying member supplies a developer to an electrostatic latent image formed on the circumferential surface of the electrophotographic photosensitive member, and is, for example, a cylindrical or tubular member made of a non-magnetic metal or a polymer material. The developer bearing member is provided so as to be rotatable so as to face the electrophotographic photosensitive member and has a developing bias applying section for applying a developing bias.

Further, a developer regulating member is provided on the upstream side of the rotational direction of the developer carrying member based on the position where the developer carrying member and the electrophotographic photosensitive member face each other. The developer regulating member is a member that uniformizes the thickness of the developer carried on the peripheral surface of the developer carrying member, and can be constituted by, for example, a metal blade.

In the case where the developer is a non-magnetic one-component toner, the developer conveyed by the agitating conveying member or the like is directly supplied to the surface of the developer carrying member by the developer and / or the developer supplying member. A predetermined developing bias is applied between the developer carrying member and the electrophotographic photosensitive member, and the developer on the developer carrying member emits a toner image (visible image) on the electrophotographic photosensitive member according to the electrostatic latent image.

[Means of warrior]

Examples of the transferring portion which is a transferring means include transferring a toner image to a transferring object by applying an electric charge of a polarity opposite to that of the toner to the transferring object from behind the transferring object and transferring the toner image to the transferring object by an electrostatic force, A transfer roll and a transfer roll pressing apparatus using a conductive or semiconductive roll or the like which are directly contacted and transferred via the intermediary of a transfer roll and a transfer roll pressing apparatus. The transfer roll may be applied with a direct current as a transfer current applied to the latent electrostatic image bearing member, or alternatively, an AC current may be superimposed. The transfer roll can be arbitrarily set by the image area width to be charged, the shape of the transfer charger, the aperture width, the process speed, and the like. In addition, a monolayer foil roll or the like is suitably used as the transfer roll for low cost. In the transferring method, the transferring method may be a method of transferring directly to a transfer destination such as paper or a transfer transferring method to a transfer destination via an intermediate transferring device.

A known intermediate transfer member can be used as the intermediate transfer member. Examples of the material used for the intermediate transfer body include a polycarbonate resin (PC), polyvinylidene fluoride (PVDF), a polyalkylene phthalate, a blend material of PC / polyalkylene terephthalate (PAT), an ethylene tetrafluoroethylene copolymer ETFE) / PC, ETFE / PAT, and blend materials of PC / PAT. From the viewpoint of mechanical strength, an intermediate transfer belt using thermosetting polyimide resin is preferable.

[Cleaning means]

With respect to the cleaning unit serving as the cleaning means, the blade cleaning method, the brush cleaning method, and the roll cleaning method may be appropriately selected as long as the residual toner on the latent electrostatic image bearing member is cleaned. Among them, it is preferable to use a cleaning blade having elasticity.

[Settlement means]

The fixing unit which is the fixing unit (image fixing unit) includes a roller or a belt-like fixing member by fixing the toner image transferred to the conveyance body by heating, pressing or heating and pressing.

Such an image forming apparatus can form an image on a recording material (e.g., recording paper, plastic sheet or the like) in accordance with image information, and the image information can be recorded on an image reading apparatus connected to the image forming apparatus, And input from a host device such as a personal computer communicably connected to the apparatus main body.

Next, the developing device which is the developing means of the above-described image forming apparatus will be described in more detail.

[Description of developing apparatus]

Fig. 4 is a cross-sectional view showing the schematic configuration of the developing apparatus 100 according to the present embodiment, and is mounted on the above-described image forming apparatus. For example, the image forming apparatus provided with the developing apparatus 100 corresponding to each color of magenta, yellow, cyan, and black can color magenta, yellow, cyan, and black colors by development by the developing apparatus 100 To form a color image. The image forming apparatus includes a recording medium conveying unit for conveying the sheet in addition to the developing apparatus 100 having the developing roller 110 (developer bearing member) for forming a toner image, a transferring unit for transferring the toner image to the sheet, A photosensitive drum 30 as an electrostatic latent image bearing member on which an image is formed on the peripheral surface, and a fixing unit for attaching the toner image to the sheet.

When the image signal of the image to be recorded is input to such an image forming apparatus, the control unit of the image forming apparatus uniformly charges the surface of the photoconductive drum 30 to a predetermined potential by the charging roller based on the received image signal. Thereafter, the surface of the photoconductor drum 30 is irradiated with laser light by the exposure unit to form an electrostatic latent image. On the other hand, in each developing apparatus 100, the toner T (developer) in the developing chamber is carried on the developing roller 110 by the toner supplying roller 120 (developer supplying member).

When the toner is conveyed to the area opposed to the photosensitive drum 30 by the rotation of the developing roller 110, the toner carried on the developing roller 110 is conveyed to the electrostatic latent image formed on the peripheral surface of the photosensitive drum 30 And the electrostatic latent image is developed. This phenomenon is performed for each color of magenta, yellow, cyan, and black. The thus formed toner image is primarily transferred from the photosensitive drum 30 to the transfer belt in a region where the photosensitive drum 30 and the transfer belt face each other. Then, the toner image is secondarily transferred onto the paper conveyed by the recording medium conveying unit. Thereafter, the paper onto which the toner image has been secondary-transferred is conveyed to the fixing unit, is fixed, and is discharged to the outside of the image forming apparatus.

4, the developing apparatus 100 includes a toner supplying roller 120, a toner containing chamber 130 (developer receiving chamber), an elastic contact member 142, A developer reservoir 140 (developer regulating member), a developing chamber 150, a toner reservoir 160 (developer reservoir), a partition wall 170, a conveying member 135 and a stirring member 165, . In the image forming apparatus, the developing apparatus 100 is provided corresponding to each color of magenta, yellow, cyan, and black, but the basic configuration is the same except for the type of the toner which is the developer, .

The toner containing chamber 130 is a chamber for containing the toner T. The developing chamber 150 is a yarn that is developed by the developing roller 110 and is arranged adjacent to the upper side of the toner containing chamber 130. A partition wall 170 is provided between the toner storage chamber 130 and the developing chamber 150 so that the partition wall 170 separates the two chambers 130 and 150. An opening 172 is provided in a part of the partition wall 170 and the toner containing chamber 130 and the developing chamber 150 are connected to each other via the opening 172. The toner storage chamber 130, the developing chamber 150, and the partition wall 170 are integrally formed.

The toner storage chamber 130 is provided with a conveying member 135 for conveying the toner T to the developing chamber 150. The conveying member 135 is a rotatable conveying member that rotates the toner T accommodated in the toner accommodating chamber 130 through the opening 172 of the partition wall 170 into the developing chamber 150 And returns it to a specified amount.

The toner supply roller 120 is rotated by the toner T supplied from the toner containing chamber 130 by the transporting member 135 and the toner T scraped off from the developing roller 110 by the elastic blade 140, Is a supplying member for supplying the toner T stirred and mixed in the stirring member 165 to the developing roller 110. The toner supplying roller 120 is disposed in the developing chamber 150 so as to face the developing roller 110 so as to come into contact with the peripheral surface of the developing roller 110. The toner supply roller 120 is made of an elastic member such as polyurethane foam, and is formed to be elastically deformable. The toner supply roller 120 is in contact with the developing roller 110 in an elastically deformed state.

The toner supply roller 120 rotates counterclockwise, for example, and is configured so as to move in a direction opposite to the developing roller 110 in a contact area with the developing roller 110 that rotates in the counterclockwise direction. Mixed toner T is adhered to the surface of the toner supply roller 120 having such a configuration and the surface of the toner supply roller 120 contacts the surface of the developing roller 110 The toner T is supplied from the supply roller 120 to the developing roller 110 to carry the toner to the developing roller 110. [ The toner supply roller 120 also discharges the toner T that has not passed through the developing nip with the photosensitive drum 30 and has not been used for development from the developing roller 110 simultaneously with the supply of the toner T, (T) stays on the developing roller 110 for a long time, thereby preventing the charging amount from rising excessively.

The developing roller 110 carries the toner T supplied from the toner supplying roller 120 on the surface thereof and conveys the toner T to a region opposed to the photosensitive drum 30, A member for developing the electrostatic latent image by moving the toner T to an electrostatic latent image formed on the circumferential surface, the toner supply roller 120 being opposed to the toner supply roller 120 so as to come into contact with the circumferential surface of the toner supply roller 120, Is disposed in the developing chamber (150) so as to face the drum (30).

[Composition of developer carrying member]

The developing roller 110 has a surface having a plurality of convex portions 112 configured to bear the developer and a concave portion 114 surrounding each of the convex portions 112 (hereinafter referred to as &quot; developer bearing surface &quot; For example, a roller base material such as an aluminum alloy or an iron alloy is surface-processed by a known method such as a rolling method or an etching method, and then additional processing such as polishing or plating is added as needed do.

Fig. 5 shows an example of a preferred embodiment of the present invention. The convex portion 112 on the developer-carrying surface of the developing roller 110 indicates a rhomboid or a square, and one diagonal line is a rotational axis In the X direction). In this case, when the convex portion 112 is sectioned along the line C-C, it shows a trapezoidal shape.

The height difference between the top surface of the convex portion 112 and the bottom surface of the concave portion 114 is 0.8 times or more and less than 5.0 times the weight average particle diameter D4 of the developer, (The X direction in FIG. 5A) and the circumferential direction (the Y direction) of the convex portions 112 forming a part of the cylindrical surface having the same top surface on the sheet surface (Hereinafter referred to as &quot; area ratio of the top of the convex portion &quot;) of the total top surface of the plurality of convex portions 112 with respect to the area of the entire circumferential surface is 3% Or more and less than 40%.

The ratio of the height difference between the top surface of the convex portion 112 of the developing roller 110 and the bottom surface of the concave portion 114 and the total surface area of the top surface of the convex portion 112 in the present invention is defined as follows do.

As shown in Fig. 6 (a), the surface shape of the vicinity of the top of any convex portion and the bottom surface of the concave portion surrounding the convex portion is measured, and the highest point existing near the top of the convex portion, (Hereinafter referred to as a &quot; maximum elevation difference &quot;) is measured.

Quot; the difference in height between the top surface of the convex portion and the bottom surface of the concave portion &quot; of the present invention is defined as an average value of the maximum height differences obtained by performing the same measurement on other convex portions existing on the developer carrying member (H) of the concave portion ").

On the other hand, the ratio of the total area of the top surface of the convex portion to the area of the imaginary whole circumferential surface of the developer-carrying surface of the developer carrying member is defined as follows.

6 (b), a downward point (hereinafter referred to as &quot; 10% downward point &quot;) corresponding to 10% of the elevation difference H is determined from the highest point of the arbitrary convex portion, A convex portion that extends from the highest point of the convex portion to a point 10% below the convex portion is regarded as the top surface of the convex portion and a projection image generated when the top surface of the convex portion 112 is projected from a vertical direction to a plane (See Fig. 6 (c)).

It should be noted that the same measurement is also performed on other convex portions present on the developer carrying member, and the average value thereof is defined as the &quot; area of the top surface of the convex portion &quot; of the present invention (hereinafter referred to as &quot; The total area of the top surface of the convex portion is determined by multiplying the area of the top surface by the total number of convex portions present on the developer-carrying surface.

Specifically, when the developer carrying member is a developing roller, eight different convex portions are selected in each of the three regions of the center portion and left and right end regions of the developing roller to measure the maximum height difference, and then the average value is calculated. The height difference H between the defined convex portion and the concave portion is determined (see Fig. 6 (b)). Thereafter, a 10% downward point is determined to determine the area of the top surface of the convex portion, and finally the total area of the top surface of the convex portion is determined to calculate the ratio of the total area of the top surface of the convex portion occupying the entire surface of the developer bearing surface.

Also, even in the case where the shape of the convex portion is round, the ratio of the total height of the elevation difference H and the top surface can be obtained by the same method as described above (see FIG. 7).

The shape of the developer-carrying surface on the developer-carrying member can be measured by a conventionally known method, and examples thereof include a non-contact surface shape measuring device and a shape measuring laser microscope. Can be analyzed geometrically in the drawing by interpreting it with an analysis tool attached to the above-mentioned apparatus or using CAD (Computer Aided Design) or the like.

3 is an example of an embodiment of a preferable developer regulating member of the present invention. The base member 143 includes a base member 143, an elastic contact member 142, and a fixing member (not shown) for supporting and fixing the elastic contact member 142 to the base member 143 141). &Lt; / RTI &gt;

The elastic contact member 142 has an end extending in parallel to the axial direction of the developing roller 110 and the end of the elastic contact member 142 is located at the bottom of the concave portion 114 existing on the developer- (Hereinafter referred to as &quot; gap with the bottom surface &quot;) is larger than the weight-average particle diameter of the toner T. When the distance from the bottom surface is equal to or less than the weight average particle diameter of the toner T, the amount of toner on the developing roller can not be sufficiently secured, and image defects on the vertical lines tend to occur.

As shown in Fig. 3, by pressing the developer regulating member such as the elastic blade against the surface of the developer carrying member and changing the &quot; amount of protrusion &quot; of the developer regulating member, A thin layer of developer (toner) can be formed.

In the present invention, the &quot; amount of protrusion of the developer regulating member &quot; means the amount of protrusion of the developer regulating member that is present on the extension line passing from the rotation center of the developer carrying member through the distal end portion of the developer regulating member to the outer circumference of the developer carrying member The distance J from the point of intersection of the distal end of the member to the point of intersection with the outer circumferential surface of the developer carrying member can be geometrically determined on the drawing by CAD or the like.

As a simple measuring method, there is a method of actually measuring the length from the contact mark between the developer regulating member and the developer carrying member to the leading end of the developer carrying member, or the like, and substitution is also possible.

The elastic blade 140 regulates the layer thickness of the toner carried on the top surface of the convex portion 112 of the developing roller 110 to be one toner particle or less. That is, the elastic blade 140 prevents the excess toner particles from being carried on the top surface of the convex portion 112 of the developing roller 110. As a result, the toner particles carried on the developer-carrying surface of the developing roller 110 can be uniformly and efficiently transferred, making it possible to rapidly shift to a charging state desirable for development. On the other hand, if the excess toner particles are present on the top surface of the convex portion 112, the excess toner particles themselves can not be subjected to good charge application, and the transfer of the other toner particles is inhibited.

The elastic blade 140 is arranged such that the contact position S2 with the developing roller 110 is below the contact position S1 between the developing roller 110 and the toner supplying roller 120 ). The elastic blade 140 adjusts the layer thickness of the toner T supplied from the toner supply roller 120 to the developing roller 110 before the developing roller 110 moves the toner to the photosensitive drum 30 . The excess toner T among the toners T carried by the developing roller 110 is scraped off by the elastic blade 140 and collected in the toner storage section 160. [ The toner storage portion 160 is provided with a stirring member 165. The residual toner T and the toner T newly supplied from the toner storage chamber 130 are stirred and mixed by the stirring member 165, Is used for development.

As described above, according to the present invention, the excessive developer regulated by the elastic blade 140 from the surface of the developing roller 110 is not directly collected in the developer containing chamber 130, And is collected in the developer storage section 160. The residual developer recovered in the developer storage section 160 is already adequately charged so that the partition wall 170 forming the developer storage section 160 and the developing roller 110 and the toner supplying roller 120 and the contact position S1 of the developing roller 110, it is possible to easily fall into the concave portion of the surface of the developing roller 110 while maintaining a gentle consolidation state due to the electrostatic repulsion between the developers do.

In the developing apparatus 100, the contact position S2 of the developing roller 110 and the elastic blade 140 is lower than the contact position S1 of the developing roller 110 and the toner supplying roller 120 (Between the developing roller 110 and the toner supply roller 120 at the contact position S1) between the toner supply roller 120 and the partition wall 170 forming the developing roller 165, (The amount of protrusion) between the developing roller 110 and the developer regulating member 140 can be widened, so that the developing roller 110 can be smoothly and smoothly have.

In the developing apparatus 100, since the dimensional tolerance of the protruding amount J of the elastic blade 140 with respect to the developing roller 110 is wide, the contact area of the contact portion of the elastic blade 140 Wear and the like occur, and even if the amount of protrusion changes, it is easy to keep the amount of protrusion after the wear still within the predetermined dimensional tolerance. Since the self-cleaning can be performed by setting the wear of the contact portion of the elastic blade 140 to be reduced, for example, when the surface hardness ratio of the elastic contact member 142 to the developing roller 110 is 0.20 Or more and less than 1.00 are preferably selected.

As a result, filming of the toner can be prevented, so that not only the toner particles can be maintained in a charged state, but also the toner particles can be maintained in the best state. As a result, for example, it is possible to suppress the occurrence of image density unevenness in the vertical stripe pattern, to minimize the deterioration / fluctuation of toner contamination, fine line reproducibility and color taste in the non-image area corresponding to the image density and the print background Thereby making it possible to provide an excellent developing apparatus capable of performing the development.

Further, when the above developing apparatus is used in an image forming apparatus of the process cartridge type, which is susceptible to external stress from the outside, the effect is remarkably enhanced.

Example

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited to these examples.

&Lt; Production example of developer >

[Production example of one-component developer (black color)] [

The following components were dry mixed and kneaded with a biaxial kneader.

Styrene-butyl acrylate resin (Mw = 50,000, Tg = 60 占 폚) 100 parts by mass

Carbon black (average particle diameter = 40 nm) 5 parts by mass

1 part by mass of aluminum compound of a saccharide derivative (manufactured by Orient Chemical Industries, Ltd.)

· Ester wax (Peak temperature of maximum endothermic peak of DSC = 70 ° C) 5 parts by mass

The obtained kneaded product was cooled, pulverized to a size of about 1 mm or less, and further finely pulverized using a mechanical pulverizer. The resulting pulverized material was classified to obtain classified particles.

Next, 100 parts by mass of the classified particles obtained above were put into a dry mixer together with the following components, premixed at a low rotation speed, and further subjected to dry mixing at a high rotation speed for 5 minutes.

Hydrophobic-treated silica fine particles (number average particle diameter = 0.1 mu m) 0.5 parts by mass

Hydrophobic-treated silica fine particles (number average particle diameter = 0.02 占 퐉) 1.0 parts by mass

· Hydrophobicized titania fine particles (number average particle diameter = 0.02 μm) 1.0 parts by mass

After dry mixing, coarse particles were removed by sieving to obtain a black one-component developer.

[Production example of one-component developer (yellow color)] [

A one-component yellow color developer was obtained in the same manner as in &quot; Production Example of One Component Developer (Black Color) &quot; except that 7 parts by mass of &quot; CI Pigment Yellow 180 &quot; was used instead of carbon black.

[Production example of one-component developer (magenta color)] [

A one-component magenta developer was obtained in the same manner as in the above-mentioned &quot; Production Example of One Component Developer (Black Color) &quot; except that 7 parts by weight of &quot; CI Pigment Red 180 &quot; was used instead of carbon black.

[Production example of one-component developer (cyan color)] [

A one-component cyan developer was obtained in the same manner as in &quot; Production Example of One Component Developer (Black Color) &quot; except that 5 parts by mass of "CI Pigment Blue 15: 3" was used instead of carbon black.

In the present invention, the weight average particle size (D4) of the one-component developer or the number of particles of 3 mu m or less in the particle diameter frequency distribution based on the number can be measured with a precision particle size distribution measuring device "Multisizer 3" Quot; toner particle size distribution measuring method &quot; (http://www.beckmancoulter.co.jp/product/product03/toner/), which is described on the Internet homepage of Beckman Coulter, 04.html) and the like.

As a specific measuring method, 100 ml of an electrolytic solution "ISOTONE II PC" (manufactured by Beckman Coulter) was prepared in a beaker for preparing a suspension, 0.1 g of a surfactant (preferably LAS; linear alkylbenzenesulfonic acid sodium) , And 5 mg of a measurement sample (toner particle or one-component developer) are added to prepare a toner suspension. Next, in order to increase the dispersibility of the measurement sample in the toner suspension, an ultrasonic irradiation treatment from the outside is performed for 2 minutes using an ultrasonic bus or the like to prepare a measurement sample. An aperture tube having an aperture diameter of 50 mu m is used, and the volume and the number of the measurement sample are measured for each channel to calculate the volume distribution and the number distribution of the measurement sample. The weight average particle diameter (D4) of the measurement sample is obtained from the calculated distribution.

The one-component developers of the respective colors obtained in the above Production Examples were all prepared so that the weight average particle diameter (D4) was 6.5 占 퐉 and the number of particles of developer of 3 占 퐉 or less in the particle diameter frequency distribution on the number basis was 10%.

&Lt; Production example of developer carrying member >

[Production example 1 of developer carrying member]

(Hereinafter referred to as &quot; cylindrical surface &quot;) of a cylindrical roller base material made of a carbon steel pipe having a diameter of 16 mm was polished by a Centras polishing machine, The roller base material is provided in the rolling apparatus having the first and second dies provided with the projecting stems corresponding to the respective grooves so as to form the grooves in the directions indicated by the arrows A and B in Fig. Then, while the dice and the roller base material were rotated at a constant speed, the dice were pressed while the roller base material was being fed, and the first and second grooves were transferred to the roller base material.

As a result, a rolling roller having a plurality of convex portions regularly arranged on a cylindrical surface and a concave portion surrounding the convex portion on the surface thereof, and having a convex portion having the same surface as each other was obtained.

The cylindrical surface of the obtained rolling roller was again polished by a centreless polishing machine, and the height difference between the convex portion and the concave portion was adjusted, followed by immersion in the heated degreasing liquid to perform degreasing treatment.

Further, the degreased rolling rollers were immersed in a warmed Ni-P plating bath and electroless plating was performed on the cylindrical surface, followed by cleaning and drying thereof to form a developer-bearing surface (FIG. 5 (See Fig. 5 (a)) was produced on a developing roller &quot; Developer carrying member T-1 &quot;.

The height difference between convex and concave portions formed on the cylindrical surface of the obtained &quot; developer carrying member T-1 &quot; was 12 m, the area ratio of the top surface of convex portions was 11%, and the Vickers hardness on the surface of the developing roller was 700 Hv.

[Production examples 2 to 5 of developer carrying member]

Except that the preparation conditions of the rolling rollers and the adjustment conditions of the elevation difference between the convex portion and the concave portion due to polishing were changed and the content of the P component and the heat treatment conditions at the time of electroless plating were changed, Developing carrier T-2 to 5 &quot; in which the difference in height between the convex portion and the concave portion, the area ratio of the top surface of the convex portion and the surface hardness were different.

[Production Examples 6 and 7 of Developer Carrying Member]

The difference in height between the convex portion and the concave portion was measured in the same manner as in &quot; Production Example 1 of developer carrying member &quot; except that the cylindrical surface was processed by etching and the P component content and the heat treatment conditions were changed during electroless plating. , Developing rollers &quot; Developer carrying members E-1 and E-2 &quot; having different area ratios and surface hardness at the tops of convex portions were prepared.

[Production Examples 1 to 3 of a developer carrying member for comparison]

Except that the preparation conditions of the rolling rollers and the adjustment conditions of the elevation difference between the convex portion and the concave portion due to polishing were changed and the content of the P component and the heat treatment conditions at the time of electroless plating were changed, 6 to 8 &quot; were prepared in the same manner as in &quot; Production Example 1 &quot;, except for the difference in height between convex and concave portions, the area ratio and the surface hardness of the top surface of the convex portion.

[Production Example 4 of the developer carrying member for comparison]

The difference in height between the convex portion and the concave portion was measured in the same manner as in &quot; Production Example 1 of developer carrying member &quot; except that the cylindrical surface was processed by etching and the P component content and the heat treatment conditions were changed during electroless plating. , Developer roller for comparison "Developer carrying member e-3" having different surface area and surface hardness of the top surface of the convex portion were prepared.

The contents of the developing rollers and the comparative developing rollers obtained in Production Examples 1 to 7 of the developer carrying members and in Production Examples 1 to 4 of the comparative developer carrying members are summarized in Table 1 below.

&Lt; Example 1 >

As the image forming apparatus, the developing unit unit of "SAMSUNG MultiXpress CLX-9301NA (Samsung Electronics Co., Ltd.) ", which is a color multifunctional apparatus compatible with A3 size paper, is replaced with &quot; / Adjusted.

The "developer carrying member T-1" obtained in the "developer carrying member production example 1" was used for the developer carrying member of the black developing unit of the image forming apparatus and the elastic contact member of the developer regulating member was made of stainless steel A thin steel plate (plate thickness = 80 탆, Vickers hardness = 350 Hv) was used. Further, 150 g of the black one-component developer obtained in the above &quot; Production Example of one-component developer (black color) &quot;

Therefore, the height difference (H) between the convex portion and the concave portion of the &quot; developer carrying member T-1 &quot; at this time is 1.9 times the weight average particle diameter of the black one-component developer, The surface hardness ratio of the contact portion of the developer regulating member was 0.50.

[Evaluation of regulated amount of developer on the surface of the developer carrying member against the amount of protrusion of the developer regulating member]

(Hereinafter referred to as &quot; regulated amount &quot;) on the surface of the developer carrying member with respect to the amount of protrusion of the developer regulating member (hereinafter referred to as &quot; protrusion amount &quot;), (23 DEG C / 50% Rh).

First, a developer amount regulating member whose projection amount is adjusted by a dedicated jig is mounted on the developing unit and a solid image is printed. Then, the developing unit is operated for 15 seconds without consuming the developer, After regulating the developer regulating condition, the regulated amount was measured. In order to measure the regulated amount, a suction-and-attraction charge amount measuring apparatus was used.

Fig. 11 shows the results of measurement of the regulated amount of the developer on the surface of the developer carrying member relative to the amount of protrusion of the developer regulating member at this time.

The developer regulating amount on the developer carrying member with respect to the amount of protrusion of the developer regulating member generates the inflection point A after the regulating amount increases with the increase of the protrusion amount. When the amount of protrusion was further increased, the inflection point B was again generated when the amount of protrusion was 0.83 mm. The regulated amount of the developer on the surface of the developer carrying member at this time was 0.34 mg / cm 2. When the top surface of the convex portion of the surface of the developer carrying member was observed, the developer particles were regulated as one layer or less, The developer particles on the surface of the developer carrying member completely filled the convex portions, and the developer particles were changed to be supported over one layer.

When the regulated amount of the developer on the surface of the developer carrying member is 0.30 mg / cm 2, the amount of protrusion of the developer amount regulating member is 0.53 mm, and the amount of protrusion when the permissible variation amount of the developer regulated amount is ± 0.02 mg / (Upper limit: 0.69 mm, lower limit: 0.37 mm) of 0.32 mm, and exhibited the assemblability that can be easily handled even in mass production.

[Picture Quality Evaluation]

After regulating the regulated amount of developer on the surface of the developer carrying member at a temperature of normal temperature and humidity (23 ° C / 55% RH) to 0.30 mg / cm 2, 30,000 pieces of black images were printed out in monochromatic mode , And the image quality of the image obtained immediately after and immediately after the start of printing was evaluated. As the transfer material, a full-color copier paper C2 (70 g / cm2, A4 size) manufactured by Fuji Xerox Co., Ltd. was used.

As a result, the obtained image maintains the reproducibility of the excellent image density and the small-point character image from immediately after the start of printing to the end, and at the same time, the toner contamination in the non-image area is suppressed, There was no occurrence of image densification in the form of a vertical stripe pattern.

After the completion of the evaluation, the regulated amount of the developer at several points on the surface of the developer carrying member was checked, and it was maintained within the range of 0.30 mg / cm 2 0.02 mg / cm 2. In addition, filming and fixing of the developer were not observed on the surface of the developer carrying member, and a satisfactory state was maintained.

&Lt; Comparative Example 1 &

Except that the regulated amount of the developer on the surface of the developer carrying member was adjusted to 0.43 mg / cm 2 (in a state in which the developer particles on the surface of the developer carrying member had all the convex portions and the developer particles were carried over one layer) Quot; Example 1 &quot;.

As a result, since the developer regulating amount is excessive, the charged state of the developer becomes insufficient, and the obtained image shows a sufficient image density immediately after the start of printing, but the small point character image becomes thicker in line width, Toner contamination occurred. If the printout was continued in that state, the image density was lowered at the end of 30,000 sheets, and the toner contamination in the non-image area became worse. In addition, an image density unevenness in the form of a vertical striped pattern caused by the unevenness of the developer on the surface of the developer-carrying member also occurred, and the regulated amount of the developer on the surface of the developer- Causing a large variation in the regulated amount.

&Lt; Comparative Example 2 &

Instead of the &quot; one-component developing unit-A1 &quot;, the &quot; one-component developing unit-A2 &quot; Having a structure in which the rotation direction of the developer supply member is rotated so as to move in the same direction at a contact position with the developer carrying member. &Quot; Example 1 &quot;

As a result, since the rotation direction of the developer supplying member is changed to move in the same direction as the developer carrying member at the contact position, the developer regulating amount of the surface of the developer carrying member with respect to the amount of protrusion of the regulating member, The regulated amount abruptly increased and the bent point B was generated when the protrusion amount became 0.55 mm (see Fig. 12).

When the regulated amount of the developer on the surface of the developer carrying member is 0.30 mg / cm 2, the amount of protrusion of the developer regulating member is 0.45 mm, and the amount of protrusion when the allowable variation amount of the developer regulated amount is ± 0.02 mg / (Upper limit: 0.49 mm, lower limit: 0.41 mm) can not be ensured, and it has been found that the dimensional tolerance of 0.08 mm (upper limit: 0.49 mm, lower limit: 0.41 mm)

Next, by performing the image quality evaluation as in &quot; Example 1 &quot;, since the rotational direction of the developer supplying member is in the same direction as the developer carrying member, the replacement efficiency of the developing solution on the developer carrying member surface is reduced However, since the developer particles are packed in the concave portions of the developer carrying member surface, the frictional charging due to the transfer of the developer particles is inhibited. As a result, the image density is low and toner contamination occurs in the non-image areas immediately after the start of printing. In addition, a plurality of vertical striped image density unevenness caused by the unevenness of the developer on the surface of the developer carrying member occurred, and these phenomena deteriorated with the progress of the printout.

Further, after the completion of the evaluation, when the regulated amount of the developer on the surface of the developer carrying member was checked, a large variation was caused in the regulated amount in the axial direction of the developer carrying member.

&Lt; Comparative Example 3 &

Instead of the &quot; one-component developing unit-A1 &quot;, the &quot; one-component developing unit-A3 &quot; Having a structure in which a part of the partition wall partitioning the developer containing chamber and the development chamber is removed and the surplus developer regulated by the developer regulating member can be directly recovered to the developer containing chamber " Quot; Example 1 &quot;.

As a result, a part of the partition wall partitioning the developer receiving chamber and the developing chamber is removed, and the excess developer restricted by the developer regulating member is changed to a structure capable of directly recovering the excess developer to the developer containing chamber. The regulation amount of the developer on the surface of the developer carrying member against the amount of protrusion of the regulating member sharply increased with the increase of the protrusion amount and the inflection point B when the protrusion amount was 1.10 mm.

When the regulated amount of the developer on the surface of the developer carrying member is 0.30 mg / cm 2, the amount of protrusion of the developer regulating member is 0.81 mm, and the amount of protrusion when the allowable variation amount of the developer regulated amount is ± 0.02 mg / It is found that the dimensional tolerance of only 0.05 mm can not be ensured, which causes problems in assembling at the time of mass production.

Next, after the image quality evaluation as in &quot; Example 1 &quot;, a part of the partition wall partitioning the developer receiving chamber and the developing chamber was removed, and the excess developer regulated by the regulating member was directly collected The supply amount of the developer to the surface of the developer carrying member became unstable, resulting in a low image density immediately after the start of printing and causing a problem in reproducibility of the small point character image. In addition, a plurality of vertical striped image density unevenness caused by the unevenness of the developer on the surface of the developer carrying member occurred, and these phenomena deteriorated with the progress of the printout.

Further, after the completion of the evaluation, when the regulated amount of the developer on the surface of the developer carrying member was checked, a large variation was caused in the regulated amount in the axial direction of the developer carrying member.

&Lt; Comparative Example 4 &

The developer carrying member of the toner cartridge of "Color Laser Jet 5550 (product of Hewlett Packard Co.)" which is a color printer corresponding to A3 size paper as an image forming apparatus is referred to as "developer carrying member (Sheet thickness = 80 탆, Vickers hardness = 350 Hv), and the gap between the developer carrying member and the latent electrostatic image bearing member was 200 탆 (The &quot; one-component developing unit-B &quot; in which the contact position between the developer carrying member and the developer regulating member is provided above the contact position between the developer carrying member and the developer supplying member (Having a structure in which the excess developer restricted by the developer regulating member is directly recovered in the developing chamber "), the black one-component developer obtained in the above-mentioned &quot; Production Example of one-component developer (black color) &quot; 280 g was put in There was carried out the evaluation tests, such as "Example 1".

As a result, the contact position between the developer carrying member and the developer regulating member is provided above the contact position between the developer carrying member and the developer supplying member, and the excess developer regulated by the regulating member is directly collected The regulation amount of the developer on the surface of the developer carrying member with respect to the amount of protrusion of the developer regulating member increases sharply with the increase of the protrusion amount and the inflection point B is generated when the protrusion amount is 0.90 mm .

When the regulated amount of the developer on the surface of the developer carrying member is 0.30 mg / cm 2, the protrusion amount of the regulating member is 0.61 mm, and the dimension of the protrusion amount when the allowable variation amount of the developer regulated amount is ± 0.02 mg / Only a tolerance of 0.04 mm can be secured, and it has been found that a problem arises in assembling at the time of mass production.

Next, evaluation of the image quality as in &quot; Example 1 &quot; shows that the contact position between the developer carrying member and the developer regulating member is provided above the contact position between the developer carrying member and the developer supplying member, The developed image showed a sufficient image density immediately after the start of printing, but toner contamination occurred in the non-image area. If the printing was continued in this state, the toner contamination in the non-image area temporarily improved, but toner contamination in the non-image area again deteriorated at the time of replenishment of the developer, and the image density also dropped at the end of 30,000 sheets of printout. In addition, image density unevenness in the form of a vertical stripe pattern caused by the unevenness of the developer on the developer carrying member surface also occurred.

&Lt; Comparative Example 5 &

As the developing unit, &quot; one-component developing unit -C; A structure in which the rotation direction of the developer supply member is rotated so as to move in the same direction as the developer carrying member and the excess developer restricted by the developer regulating member is collected in the developer storage portion in the upper portion of the developing chamber Quot ;, the evaluation test was conducted as in &quot; Comparative Example 4 &quot;.

As a result, there is a structure in which the rotation direction of the developer supply member is rotated to move in the same direction as the developer carrying member, and the excess developer regulated by the developer regulating member is collected in the developer storage portion in the upper portion of the developing chamber The regulation amount of the developer on the surface of the developer carrying member against the amount of protrusion of the developer regulating member sharply increases with the increase of the protrusion amount and the inflection point B when the protrusion amount is 0.88 mm.

When the regulated amount of the developer on the surface of the developer carrying member is 0.30 mg / cm 2, the amount of protrusion of the regulating member is 0.85 mm, and the dimension of the amount of protrusion when the allowable variation of the developer regulated amount is ± 0.02 mg / Only a tolerance of 0.04 mm can be secured, and it has been found that a problem arises in assembling at the time of mass production.

Next, evaluation of the image quality as in &quot; Example 1 &quot; shows that the rotation direction of the developer supply member is the same direction as the developer carrying member, and the excess developer regulated by the regulating member is the developer storage Toner contamination occurred in the non-image area immediately after the start of printing. In addition, reproducibility of the image density and small-point character images remarkably deteriorated with the progress of the printout, and a plurality of image density unevenness in the vertical stripe pattern caused by the unevenness of the developer on the surface of the developer carrying member occurred.

Further, after the completion of the evaluation, when the regulated amount of the developer on the surface of the developer carrying member was checked, a large variation was caused in the regulated amount in the axial direction of the developer carrying member.

The configuration of the developing unit used in the "Example 1 and Comparative Examples 1 to 5" is shown in Table 2, and the evaluation results are shown in Table 3 together. The evaluation criteria of each item listed in the table are as follows.

[One. Assembling property of the regulating member in the amount of developer]

The dimensional tolerance of the amount of protrusion of the developer regulating member when the developer regulating amount on the surface of the developer carrying member is 0.30 mg / cm 2 and the allowable variation amount of the developer regulating amount is ± 0.02 mg / cm 2 is determined, Respectively.

A: Dimensional tolerance is 0.3mm or more (very easy)

B: Dimensional tolerance of 0.2mm or more and less than 0.3mm (easy)

C: The dimensional tolerance is 0.1 mm or more and less than 0.2 mm (this is an acceptable level in the present invention)

D: The dimensional tolerance is less than 0.1 mm (very difficult and unreachable in the present invention)

[2. Image density]

An image having a square solid patch of 5 mm on each side in the vicinity of the four corners and a central portion was printed and the reflection density of the solid patch was measured with a spectrophotometer Spectrofocus (manufactured by Gretech Macbeth), and the average value of the obtained measurement values was calculated And evaluated according to the following criteria.

A: 1.30 or more (very good)

B: 1.15 or more and less than 1.30 (good)

C: 1.00 or more and less than 1.15 (this is an acceptable level in the present invention)

D: less than 1.00 (not in the present invention)

[3. Reproducibility of small point character image]

Five-point character images were printed in the vicinity of the four corners and the central portion, and the reproducibility of the obtained character images was evaluated according to the following criteria.

A: Line width variation of thin wire is less than 10% (very good)

B: Line width variation of fine wire is 10% or more and less than 15% (good)

C: The change of the fine line is 15% or more, and it can be confirmed visually (it is an acceptable level in the present invention)

D: It is easy to visually confirm the contact between the fine lines and the break or cleavage of the fine line itself (this level is not possible in the present invention)

[4. Toner contamination of non-image area (print background)

During the formation of a white image, the developer present on the photoreceptor drum was transferred to the adhesion surface of a mending tape (manufactured by Sumitomo 3M Co., Ltd.) during the transition from the development step to the transfer step, and the reflection density of the toner adhered on paper was measured with a spectrophotometer (Manufactured by Grevet Macbeth), and a value obtained by subtracting the reflection density (blank) when the mending tape was directly stuck on the paper from the obtained reflection density was determined and evaluated according to the following criteria. The smaller the value is, the more the toner contamination in the non-image area is suppressed.

A: less than 0.03 (very good)

B: 0.03 or more and less than 0.07 (good)

C: 0.07 or more and less than 1.00 (this is an acceptable level in the present invention)

D: not less than 1.00 (not in the present invention)

[5. Uneven image density in the form of vertical stripes]

A halftone image constituted by a halftone dot shape was printed and the number of occurrence of image density unevenness of vertical stripe pattern formed on the obtained halftone image was measured and evaluated according to the following criteria.

A: Not occurring (very good)

B: A small number of image densities with a slight vertical stripe pattern are generated (good)

C: 2 to 4 small occurrences (acceptable level in the present invention)

D: 5 or more occurrences (this level is not possible in the present invention)

&Lt; Example 2 >

Evaluation test was conducted as in "Example 1" except that "developer carrying member T-2" obtained in "developer carrying member production example 2" was used as the developer carrying member. The difference in height between the convex portion and the concave portion of the &quot; developer carrying member T-2 &quot; at this time is 3.1 times the weight average particle diameter of the black one-component developer, The surface hardness ratio of the contact portion was 0.54.

As a result of the evaluation test, there was no problem in the assembling property of the regulating member and the obtained printout image, and the surface of the developer carrying member was also maintained in a good state.

&Lt; Example 3 >

Evaluation test was conducted in the same manner as in "Example 1" except that "developer carrying member T-3" obtained in "developer carrying member production example 3" was used as the developer carrying member. The height difference between the convex portion and the concave portion of the &quot; developer carrying member T-3 &quot; at this time is 0.8 times the weight average particle diameter of the black one-component developer, and the difference in the surface hardness of the developer carrying member The surface hardness ratio of the contact portion was 0.39.

As a result of the evaluation test, there was no problem in the assembling property of the regulating member and the obtained printout image, and the surface of the developer carrying member was also maintained in a good state.

<Example 4>

Developer carrying member T-4 &quot; obtained in &quot; Developer Example 4 of developer carrying member &quot; was used as the developer carrying member, and a thin plate of phosphor bronze (plate thickness = 100 mu m, Vickers Hardness = 190 Hv) was used as the test piece, the evaluation test was conducted as in &quot; Example 1 &quot;. The height difference between the convex portion and the concave portion of the &quot; developer carrying member T-4 &quot; at this time is 0.9 times the weight average particle diameter of the black one-component developer, and the difference between the surface hardness of the developer carrying member The surface hardness ratio of the contact portion was 0.38.

As a result of the evaluation test, there was no problem in the assemblability of the regulating member and the obtained printout image, and the surface of the developing roller was also maintained in a good state.

&Lt; Example 5 >

Evaluation test was conducted as in "Example 1" except that "developer carrying member T-5" obtained in "developer carrying member production example 5" was used as the developer carrying member. The difference in height between the convex portion and the concave portion of the &quot; developer carrying member T-5 &quot; at this time was 4.8 times the weight average particle diameter of the black one-component developer and the contact portion of the regulating member with respect to the surface hardness of the developer carrying member Surface hardness ratio of 0.37.

As a result of the evaluation test, there was no problem in the assembling property of the regulating member and the obtained printout image, and the surface of the developer carrying member was also maintained in a good state.

&Lt; Example 6 >

The developer carrying member E-1 obtained in the &quot; developer carrying member 6 &quot; was used as the developer carrying member, and a thin plate of stainless steel (plate thickness = 70 mu m, Vickers hardness = 450Hv) was used as the test sample. The convex portion and the concave portion of the &quot; developer carrying member E-1 &quot; at this time had a height difference of 4.9 times the weight average particle diameter of the black one-component developer and the contact portion of the regulating member with respect to the surface hardness of the developer carrying member Had a surface hardness ratio of 0.90.

As a result of the evaluation test, the protrusions on the surface of the developer carrying member were deformed by abrasion and the developer particles were slightly adhered, but there was no problem in the assembling property of the regulating member and the printed-out image obtained.

&Lt; Example 7 >

The developer carrying member E-2 obtained in the "developer carrying member Production Example 7" was used as the developer carrying member and a thin plate of phosphor bronze (sheet thickness = 120 μm, Vickers hardness = 150 Hv ) Was used as the test sample, the evaluation test was conducted as in &quot; Example 1 &quot;. The height difference between the convex portion and the concave portion of the &quot; developer carrying member E-2 &quot; at this time is 4.0 times the weight average particle diameter of the black one-component developer, The surface hardness ratio of the contact portion was 0.20.

As a result of the evaluation test, slight filming due to the developer particles occurred on the surface of the developing roller, but there was no problem in the assembling property of the regulating member and the printed image obtained.

&Lt; Comparative Example 6 >

Developer carrying member t-6 &quot; obtained in Production Example 1 of the comparative developer carrying member was used as the developer carrying member, and a thin plate of stainless steel (sheet thickness = 70 mu m, Vickers hardness = 440 Hv) was used as the test sample. The difference in height between the convex portion and the concave portion of the &quot; developer carrying member t-6 &quot; at this time is 3.2 times the weight-average particle diameter of the black one-component developer, and the surface of the contact portion of the regulating member The hardness ratio was 1.02.

When the regulation amount of developer on the surface of the developer carrying member was checked before the evaluation test, the assembling property of the regulating member was satisfied, but the area ratio of the top surface of the convex portion of the developer carrying member was 40% or more (43% , A large variation is caused in the regulated amount in the axial direction of the developer carrying member.

The printout image obtained by the evaluation test can not obtain a sufficient image quality, such as a stain of image density and printing background caused by uneven regulation from the start of printing. In addition, since the surface hardness ratio of the contact portion of the regulating member to the surface hardness of the developer carrying member is not less than 1.00, the wear deformation of the convex portion of the surface of the developer carrying member is significant and sticking of the developer particles occurs, It has adversely affected.

&Lt; Comparative Example 7 &

Evaluation test was conducted in the same manner as in &quot; Example 1 &quot; except that &quot; developer carrying member t-7 &quot; obtained in &quot; preparation example 2 of developer carrying member for comparison &quot; was used as the developer carrying member. The convex portion and the concave portion of the &quot; developer carrying member t-7 &quot; at this time had a height difference of 0.6 times the weight average particle diameter of the black one-component developer and the contact portion of the regulating member with respect to the surface hardness of the developer carrying member Surface hardness ratio of 0.50.

As a result of the evaluation test, since the height difference between the convex portion and the concave portion of the developing roller is less than 0.8 times the weight average particle diameter of the developer, there arises a problem in the assembling property of the regulating member, Sufficient image quality could not be obtained due to toner contamination in the area.

&Lt; Comparative Example 8 >

Developer carrying member t-8 &quot; obtained in Production Example 3 of the comparative developer carrying member was used as the developer carrying member and a thin plate of phosphor bronze (plate thickness = 120 m, Vickers hardness = 150Hv) was used as the test sample. The difference in height between the convex portion and the concave portion of the &quot; developer carrying member t-8 &quot; at this time was 2.8 times the weight average particle diameter of the black one-component developer, and the surface of the contact portion of the regulating member The hardness ratio was 0.15.

The printout image obtained by the evaluation test was good at the start of printing, but the image quality deteriorated as the printout proceeded. Further, since the surface hardness ratio of the contact portion of the regulating member to the surface hardness of the developing roller is less than 0.20, filming caused by the developer particles is generated on the surface of the developing roller, directly adversely affecting the printout image.

&Lt; Comparative Example 9 &

Evaluation test was carried out in the same manner as in "Example 1" except that "developer carrying member e-3" obtained in "Preparation Example 4 of the comparative developer carrying member" was used as the developer carrying member. The difference in height between convex and concave portions of the "developer carrying member e-3" at this time was 5.4 times the weight average particle diameter of the black one-component developer.

When the regulated amount of the developer on the surface of the developing roller before the evaluation test is confirmed, the assembling property of the developer regulating member is satisfied, but the difference in height between the convex portion and the concave portion of the developer carrying member is 5.0 times or more , A large variation is caused in the regulated amount in the axial direction of the developer carrying member.

The printout image obtained by the evaluation test was good in the reproducibility of the image density immediately after the start of printing and the small-point character image, but it was not possible to obtain sufficient image quality such as occurrence of image density unevenness due to uneven regulation or toner contamination in the non- .

The evaluation results of the "Examples 2 to 7 and Comparative Examples 6 to 9" are summarized in Table 4 below.

&Lt; Example 8 >

The developing unit units other than the black unit of the image forming apparatus used in the "Example 1" are also exchanged with the "one-component developing unit-A1" described in FIG. 4 and adjusted / , 150 g each of the black, yellow, magenta, and cyan one-component developers obtained in the above-mentioned &quot; Production Example of Developer &quot; The "developer carrying member T-1" obtained in the "developer carrying member production example 1" was used as the developer carrying member of the "one-component developing unit-A1", and the elastic contact member of the developer regulating member A thin steel plate (plate thickness = 80 탆, Vickers hardness = 350 Hv) was used.

Therefore, the difference in height between convex portion and concave portion of &quot; developer carrying member T-1 &quot; at this time is 1.9 times the weight average particle diameter of the one-component developer of each color, The surface hardness ratio of the contact portion of the regulating member was 0.50.

After adjusting the regulated amount of developer on the surface of the developer carrying member of each color in the same manner as in &quot; Example 1 &quot;, 10,000 color images were printed by the full color mode while the developer was supplied, Image quality of the obtained printout image was evaluated. As the transferring material, a full-color copier paper C2 (70 g / cm2, A4 size) manufactured by Fuji Xerox Co., Ltd. was used.

As a result of the evaluation test, there is no problem in the assembling property of the regulating member and the obtained printout image, and the excellent image density and reproducibility of the small point character image are maintained from immediately after the start of printing to the end, It was possible to obtain a good full-color image free from image stain-like unevenness in the vertical stripe pattern due to the unevenness of the developer on the surface of the developer-carrying member.

13 is a schematic configuration diagram of a developing apparatus according to another embodiment of the present invention. Referring to Fig. 13, the developing apparatus 200 according to another embodiment of the present invention is an apparatus mounted in an image forming apparatus such as a laser beam printer. The image forming apparatus having the developing apparatus 200 forms a color image by using each color of magenta, yellow, cyan, and black by development by the developing apparatus 200. [ The image forming apparatus includes a recording medium conveying unit for conveying a sheet in addition to a developing apparatus 200 having a developing roller 210 for forming a toner image, a transfer unit for secondary transferring the toner image onto the sheet, A photosensitive drum 30 as a latent electrostatic image bearing member on which an image is formed, and a fixing unit for attaching the toner image to the sheet.

When the image signal of the image to be recorded is input to such an image forming apparatus, the control unit of the image forming apparatus uniformly charges the surface of the photoconductive drum 30 to a predetermined potential by the charging roller based on the received image signal. Thereafter, the surface of the photosensitive drum 30 is irradiated with laser light by the exposure unit 42 to form an electrostatic latent image.

In the developing apparatus 200, the toner in the developing chamber is held on the developing roller 210 by the toner supplying roller 220. [ When the toner is conveyed to the area facing the photoconductive drum 30 by the rotation of the developing roller 210, the toner carried on the developing roller 210 is conveyed to the electrostatic latent image formed on the circumferential surface of the photoconductive drum 30 And the electrostatic latent image is developed. The toner image formed in this way is primarily transferred from the photosensitive drum 30 to the transfer belt in a region where the photosensitive drum 30 and the transfer belt face each other. Toner images formed on the four photosensitive drums 30 are successively laminated on the transfer belt to form one laminated toner image. Then, the stacked toner image is secondarily transferred onto the paper conveyed by the recording medium conveying unit. Thereafter, the paper onto which the laminated toner images are secondarily transferred is conveyed to the fixing unit, fused and fixed, and discharged to the outside of the image forming apparatus.

13, the developing apparatus 200 includes a toner supplying roller (toner supplying section) 220, an elastic blade (developer regulating member) 240, a stirring member 235).

The toner supplying roller 220 is provided to supply toner to the developing roller 210, and a part of the toner supplying roller 220 is in contact with the developing roller 210. The toner supplied from the agitating member 235 is attached to the surface of the toner supply roller 220 and the surface of the toner supply roller 220 contacts the surface S of the developing roller 210, Toner is supplied to the developing roller 210 from the developing rollers 220 to carry the developer to the developing roller 210. [ The surface S of the toner supply roller 220 is made of an elastic member so that the toner can be supplied to the developing roller 210 suitably when the toner supply roller 220 is brought into contact with the developing roller 210. [ Also, the toner supply roller 220 peels the toner used for development from the developing roller 210 through the developing nip with the photoreceptor at the same time as supplying the toner, and the toner stays on the developing roller 210 for a long time And also has a function of preventing the increase of the amount.

The elastic blade 240 regulates the amount of toner to be charged into the developing roller 210 by contact with the developing roller 210. Since the elastic blade 240 is partly in contact with the surface S of the developing roller 210 and the surface S of the developing roller 210 rotates while contacting the blade 240, The excess toner on the image can be scraped off. As a result, the toner can be carried only on the groove portion, and the toner on the top surface can be left without the toner, so that the stress applied to the toner by the blade 240 can be minimized. Further, since the groove shape is a regular shape, the amount of toner carried per unit area of the roller can be made uniform by filling the toner only inside the groove.

The agitating member 235 moves the toner in the toner tank 22 in the left direction of the drawing and allows the toner to always be supplied to the developing roller 210 via the toner supplying roller 220. [ The stirring member 235 is configured such that a wing member 235a is mounted on the shaft portion, and the wing member 235a rotates around the shaft portion to move the toner.

As shown in Fig. 14, the developing roller 210 is a circumferential roller formed by elongating in a long shape, and toner is supported on the surface S of the developing roller 210. As shown in Fig. In the following description, the direction of the rotation axis of the developing roller 210 is the X direction and the direction of rotation of the developing roller 210 is the Y direction.

Fig. 15 is an enlarged view of a part of the surface S of the developing roller 210. Fig. As shown in FIG. 3, the surface S of the developing roller 210 is formed with a plurality of projections and depressions, and the toner enters the concave portion of the surface S of the developing roller 210, thereby supporting the toner. The concave portion of the surface S of the developing roller 210 has a first concave portion A extending in a direction inclining at about 45 degrees with respect to the Y direction and a second concave portion A extending in the direction in which the first concave portion A extends A second concave portion B extending in a 90 degree inclined direction and a third concave portion C continuous to the first concave portion A and the second concave portion B and extending in the Y direction . As described above, the surface S of the developing roller 210 is provided with the first and second concave portions A and B which are inclined with respect to the Y direction and the second concave portions A and B which are continuous to the concave portions A and B and extend in the Y direction 3 concave portions C are provided so that a plurality of hexagonal convex portions symmetrical with respect to the X direction and symmetrical with respect to the Y direction are formed.

In this developing apparatus 200, since the third concave portion C extending in the Y direction is provided, the fluctuation of the concave width according to the rotational position of the developing roller 210 becomes small, It is possible to prevent a variation in the charged amount and a deviation in the density of the image. Further, by having the third concave portion C extending in the Y direction, the toner is liable to move in the Y direction, so that stagnation of the toner is suppressed. Therefore, the problem of stagnation of the toner does not occur, and the quality of the image can be improved. Specifically, as shown in FIG. 16, in the conventional developing roller, when the number of prints is increased by using the image forming apparatus for a long period of time, the amount of toner filling on the developing roller is reduced and filing occurs. However, in the developing roller 210 of the present embodiment, even when the number of prints is increased, the toner filling amount on the developing roller 210 does not decrease, and no event such as filming occurs. Therefore, the service life of the image forming apparatus 1 can be increased.

15, the width of the first concave portion A in the X direction is denoted by a, the width of the second concave portion B in the X direction is denoted by b, the width of the third concave portion C in the X direction C = (a + b) = 1.4 is satisfied. Therefore, since the sum a + b of the widths of the first concave portion A and the second concave portion B inclined with respect to the Y direction is close to the width c of the third concave portion C extending in the Y direction, It is possible to make the amount of toner charged in the first, second and third concave portions A, B, and C uniform according to the rotational position of the developing roller 210. [ When the values of a, b and c satisfy 0.9 = c / (a + b) = 1.2, the sum a + b of the widths of the first recessed portion A and the second recessed portion B The width c of the third concave portion C becomes closer to each other, the toner charging amount can be made more uniform, and the quality of the image can be further improved.

The sum of the width a of the first concave portion A and the width b of the second concave portion B in the case where the developing roller 210 is cut in the X direction is the sum of the width a of the first concave portion A and the width b of the second concave portion B, 3 width c of the concave portion C. In this case, even if the rotational position of the developing roller 210 changes, the amount of the toner filled in the first, second and third concave portions A, B, and C does not change, And the quality of the image can be further improved.

As described above, when the value of c / (a + b) is made close to 1, the stagnation of the toner on the developing roller 210 is suppressed. Thus, as shown in Figs. 17 and 19, The lifetime of the battery can be increased. If the depth (groove depth) of the first, second and third concave portions A, B and C is h and the average particle diameter of the toner is d, then d <h <3d is preferably satisfied. In this case, as shown in the graph of Fig. 17, the toner sticking occurrence time can be lengthened, so that the service life of the image forming apparatus can be further increased.

18, when the depths of the first, second and third concave portions A, B and C are less than 21 占 퐉, for example, when the average particle diameter of the toner is 7 占 퐉, The occurrence frequency of fogging (surface contamination) in which the toner adheres to the non-image portion (surface portion) is lowered and the fog density can be made lower than the target value. In this manner, when h < 3d is satisfied, the number of toner to be filled in the concave portion becomes less than three. That is, since the toner is supported on an average of two layers, the toner is likely to contact the developing roller 210 or the blade, so that the uniformity of charging of the toner is improved and the charging uniformity It is possible to minimize the occurrence of blur. Further, by combining with the surface shape of the developing roller of the present invention, it is possible to maintain a good image with little fluctuation of image density and no fogging for a long period of time.

When the ratio of the rotational speed of the developing roller 210 to the rotational speed of the photosensitive drum 30 is v, as shown in Fig. 19, the fixing occurrence time of the toner can be made longer by setting v to 3.0 or less . In consideration of the developing ability by the developing roller 210, v is preferably 1.0 or more. As described above, the rotation speed of the developing roller 210 is preferably 1.0 times or more and 3.0 times or less the rotation speed of the photoconductor drum 30. In this case, since toner sticking is hard to occur, It is possible to prevent occurrence of ruming and increase the lifetime of the developing apparatus.

As described above, the developing apparatus of the present invention can be suitably changed within a range not departing from the spirit of the present invention. That is, the inclination angles of the first and second concave portions A and B formed on the surface S of the developing roller 210 may not be 45 degrees. In other words, the inclination angle of the developing roller 210 in the Y direction, It is good if it is inclined.

Although the image forming apparatus is exemplified as an apparatus on which the developing apparatus 200 is mounted, the developing apparatus 200 may be mounted on an apparatus other than the image forming apparatus.

The method of manufacturing the convexo-concave shape of the developing roller 210 can be produced by conventionally known etching or rolling. For the rolling process, a cylindrical mold having a pattern with irregularities in Fig. 15 is prepared, and the roller is rotated while being pressed against a cylindrical material serving as a developing roller, whereby the concavo-convex shape shown in Fig. 15 can be manufactured. After the completion of the etching or rolling process, electroless nickel plating, electroplating, hard chrome plating, and the like are performed on the uneven surface. The plating treatment smoothes minute burrs and wounds on the corners of the unevenness after the processing, and increases the hardness of the surface, thereby improving the wear resistance.

100 ... Developing device, 110 ... A developer carrying member (developing roller) 112, Convex portion,
114 ... The concave portion, 120 ... The developer supply member (toner supply roller)
130 ... A developer containing chamber (toner containing chamber), 140 ... The developer regulating member (elastic blade)
150 ... Development room, 160 ... The developer storage part, 170 ... Compartment wall, 200 ... A developing device,
210 ... Development roller, 220 ... Toner supply roller (toner supply portion), 240 ... Elastic blade,
30 ... Photoconductive drum, S ... Surface, A ... The first concave portion, B ... The second concave portion, C ... The third recess,
a ... The width of the first concave portion A, b ... The width of the second concave portion B, c ... The width of the third concave portion C

Claims (13)

A developer containing chamber for containing the developer;
A developing chamber disposed adjacent to the developer containing chamber;
A partition wall partitioning the developer containing chamber and the developing chamber and having an opening for connecting the developer containing chamber and the developing chamber;
A developer carrying member rotatably disposed to carry and convey the developer in the developing chamber;
A developer supply member which is disposed in the development chamber and supplies the developer supplied through the opening to the developer carrying member;
And a developer regulating member which is arranged to be in contact with the circumferential surface of the developer carrying member and regulates a layer thickness of the developer supplied on the developer carrying member,
The developer supply member is rotatably disposed so as to be opposed to contact on the peripheral surface of the developer carrying member, moves in a direction opposite to the developer carrying member in the contact region,
The developer carrying member is provided with a developer bearing surface having a plurality of convex portions configured to bear the developer and a concave portion surrounding each of the plurality of convex portions,
The difference in height between the top surface of the convex portion and the bottom surface of the concave portion is at least 0.8 times and not more than 5.0 times the weight average particle diameter (D4)
Wherein when a hypothetical surface obtained by extending the top surface of the convex portion in the axial direction and the circumferential direction on the developer-carrying surface is defined as an entire circumferential surface, the total surface area of the top surface of the convex portion with respect to the area of the entire circumferential surface The ratio is from 3% to less than 40%
Wherein a contact position of said developer carrying member and said developer regulating member is provided below a contact position of said developer carrying member and said developer carrying member,
Wherein the excessive developer regulated by the developer regulating member from the developer carrying member is collected in a developer storage portion disposed below the developing chamber. The method according to claim 1,
The developer regulating member has an elastic contact member having an end portion extending in the width direction at least parallel to the rotation axis of the developer carrying member,
Wherein an end portion of the elastic contact member is spaced apart from the bottom surface of the concave portion in a state where the end portion faces the concave portion is larger than a weight average particle diameter (D4) of the developer. The method according to claim 1,
Wherein the thickness of the developer supported on the top surface of the convex portion is regulated to be not more than one layer of developer particles. The method according to claim 1,
Wherein a surface hardness ratio of a contact portion of the developer regulating member to the developer carrying member satisfies a relationship of 0.20 or more and less than 1.00. The method according to claim 1,
The developer containing chamber is disposed below the developing chamber and the developer in the developer containing chamber is fed upward from below and the developer is supplied to the developing chamber via the opening portion Wherein a stirring member as far as possible is provided in the developer containing chamber. A developing roller having a convex portion and a concave portion on its surface and filling the convex portion and the concave portion with toner;
A toner supply unit for supplying toner to the developing roller;
And a developer regulating member for regulating the amount of toner to be charged into the developing roller by contact with the surface of the developing roller,
Wherein the concave portion of the surface of the developing roller has a first concave portion extending in an inclined direction with respect to a rotating direction of the developing roller and a second concave portion extending in a direction different from a direction in which the rotating direction or the first concave portion extends, And a third concave portion continuous with the first concave portion and the second concave portion and extending in the rotation direction. The method according to claim 6,
The width of the second concave portion in the direction of the rotation axis is b and the width of the third concave portion in the direction of the rotation axis is c,
0.7 = c / (a + b) = 1.4. 8. The method of claim 7,
The width of the second concave portion in the direction of the rotation axis is b and the width of the third concave portion in the direction of the rotation axis is c,
0.9 = c / (a + b) = 1.2. 9. The method of claim 8,
The sum of the width of the first concave portion and the width of the second concave portion in the case of cutting the developing roller in the direction of the rotation axis of the developing roller corresponds to the width of the third concave portion in the case of cutting in the direction of the rotation axis . The method according to claim 6,
When the depth of the concave portion of the surface of the developing roller is h and the average particle diameter of the toner is d,
d < h < 3d. The method according to claim 6,
And a photoreceptor drum which receives the supply of toner from the developing roller,
Wherein the rotation speed of the developing roller is 1.0 times or more and 3.0 times or less the rotation speed of the photoconductor drum. Electrostatic latent image bearing member;
The process cartridge according to any one of claims 1 to 11, wherein the developing cartridge is integrally formed with the latent electrostatic image bearing member. An image forming apparatus comprising the developing device according to any one of claims 1 to 11.

Images