JP2733605B2 - Developing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device applied to the development of a latent image on an image forming body, particularly an image forming body used in an electrophotographic image forming apparatus. is there.

[Background of the Invention]

In an electrophotographic image forming apparatus using a one-component or two-component developer, in order to obtain a good image, the layer thickness of the developer on a developer carrier (also referred to as a developing sleeve) is thin and uniform. It is necessary to

Conventionally, the thickness of the layer was regulated by a fixed regulation plate that has been used for a long time.However, there is a limit to the accuracy of mechanical mounting between the developer carrier and the fixed regulation plate, and the lower limit is about 0.3 mm as the layer thickness. Has become. Moreover, it was difficult to obtain a uniform and uniform thin layer by this method. However, various types of developer layer thickness control devices other than the fixing control plate have been devised for the purpose of obtaining a uniform thin layer. For example, (a) the developer layer forming apparatus described in Japanese Patent Application Laid-Open No. Sho 54-43038 discloses a developer comprising a plate-shaped elastic body having a free end on one side when a one-component toner is used. (B) The developer layer forming apparatus described in Japanese Patent Application Laid-Open No. 54848/1979 discloses a plate-like elastic body formed by laminating a metal spring and a soft elastic body. The layer thickness of the one-component developer is regulated by pressing the plate-shaped abdomen of the soft elastic body against the developer carrier.

(C) The developer layer forming apparatus described in JP-A-59-126567 and JP-A-59-129879 is a developing apparatus using a one-component type developer, which is intermittent or continuous with a developer carrier. The rotating elastic roller is pressed to regulate the layer thickness of the developer by the nip between the two.

(D) A developer layer forming apparatus described in Japanese Patent Publication No. Sho 60-12627 is a developing apparatus using a one-component developer, in which a rotating roller is brought into contact with a developer carrier made of an elastic material to reduce the layer thickness of the developer. It regulates.

(E) JP-A-62-191868 and JP-A-62-191869 disclose the development of a thin layer on a development sieve suitable for non-contact development as those improved for use in a two-component developer. Technical means for forming an agent layer are disclosed.

This is because the tip of the elastic plate supported by the support member is directed in the upstream direction of the movement of the developer on the developing sleeve, and the elastic plate is pressed onto the developing sleeve, whereby the elastic plate adheres to the developing sleeve. By regulating the layer thickness of the developer containing the magnetic carrier and the toner to be conveyed,
The thickness of the developer layer can be easily set to a thinner layer with higher precision than conventional regulating means.

(F) A two-component developer is also used.
In the developing devices described in JP-A-195958 and JP-A-62-75563, a solid plate-like layer thickness regulating member is provided, a magnetic body is arranged on the back surface thereof, and the attracting force of a fixed magnet body provided in the developer carrier is used. There is disclosed one that indirectly presses the abdomen or bent edge portion of the regulating plate to regulate the layer thickness.

[Problems to be solved by the invention]

The drawbacks of each of the developer layer forming apparatuses as conventionally proposed above are as follows. (A),
(B) Since both devices use a pressing force generated by bending a layer thickness regulating member made of an elastic body, the pressing force is controlled by the rotation speed of the developer carrier, the pressure contact position, the developer layer thickness, and the like. It is easy to change due to fluctuations, it is also easy to vibrate, and since there is no means to suppress the vibration, it comes to vibrate in resonance with the vibration generated in the image forming apparatus, so that it has a uniform thickness There is a problem that it is difficult to obtain a developer layer. In particular, in the apparatus (b), the tendency is remarkable because the pressing is performed by the soft elastic body. However, the geometrical shape of the abutting portion (nip) depends on the rotational speed of the developer carrier, the pressure contact position, and the developer. The nip is susceptible to perturbation due to variations in the layer thickness and the like, and the area of the nip changes. Therefore, there is a problem that the thickness of the developer layer tends to be uneven. In addition to such inconveniences, when one or both of the nips are formed of a soft elastic material, there is a further disadvantage that the nip is clogged by a developer and a temporal variation is caused by abrasion of the (soft) elastic material. These disadvantages are likely to occur particularly in the case of a developer containing a hard substance such as a magnetic material or a fluidizing agent. In the apparatus (c), a more uniform thin layer can be obtained more stably than in the apparatus (a), but the ability to dislodge or remove the aggregated particles of the developer due to the means for regulating the layer thickness by the rotating body. In such a case, the performance is inferior, and agglomeration of particles agglomerated in the nip portion is pinched, and the development occurs that it goes through with the rotation of the rotating body, and the satisfactory performance is obtained even by intermittent rotation. Instead, image stains, black spots, and the like occur, resulting in image quality deterioration. Further, in order to balance the pressure, the rotation mechanism, the pressure contact mechanism, and the like are complicated.

Further, in any of the apparatuses (a) to (d), in a normal developing apparatus in which the pressing area of the layer thickness regulating member is relatively large and the amount of the developer fed into the nip portion fluctuates from time to time, such a device is used. There is a disadvantage that the developer layer thickness is changed every moment by reflecting the fluctuation.

(C) and (d) show a technique for forming a thin layer of developer by pressing a developer layer thickness regulating member against a developer carrier having elasticity, which is suitable for a non-magnetic component developer. In addition, the developer carrier is permanently deformed, and the elastic modulus of the developer layer thickness regulating member is liable to change over a long period of use, and a stable layer cannot be formed.

Even in the case of (e) developed for two components, sufficient properties cannot be maintained after long-term use.

Further, in (a), (b), (e) and (f), a thin layer is formed by pressing an elastic developer layer thickness regulating plate against a rigid developer carrier (metal sleeve). ,
When used for a long period of time, the elastic plate tends to undergo a change in elastic modulus or permanent deformation, and has a shortcoming of being short in durability as a layer thickness regulating member. In addition, when the position of the elastic plate is slightly changed when the elastic plate is attached, the amount of play at the end and the pressing force change, so that it is difficult to stably regulate the layer thickness. For this reason, there is also a serious disadvantage that the mounting accuracy is extremely strict during mass production.

In particular, in (f), although the effect of loosening toner agglomeration by magnets arranged on the back surface of the developer layer thickness regulating member and inside the developer carrier slightly works, the effect of the solid plate-like regulating member is not sufficient. Because the attraction force is used, the attraction force decreases rapidly as the distance between the two magnets increases.
It is easy to spread the pressure fluctuation due to the distance fluctuation, the pressing effect on the developer layer is not stable and uniform, and the aggregates of the toner or the developer pass through, or conversely, a constant layer thickness is not obtained, There is a drawback that the image is adversely affected, for example, causing a streak and causing white stripes on the image quality.

The present invention is intended to solve these problems and to stably form a good image by uniformly forming the layer thickness of the developer on the developer carrier and forming the aggregated developer and toner. It is an object of the present invention to provide a developing device capable of preventing movement to a region.

[Means for solving the problem]

The object is to provide a fixed magnet body, a developer carrier having the magnet body therein, and having a rigidity of 10 ⁴ kg / cm ² or more, which carries a two-component developer on the surface thereof, A rod-shaped developer amount regulating member that is pressed against the carrier to face the body and regulates the amount of the two-component developer carried on the carrier; and The pressing portion is made of a material having a rigidity of 10 ⁴ kg / cm ² or more and magnetic properties, and a radius of curvature.
This is achieved by a developing device for a two-component developer, which is characterized in that the thickness is 0.5 to 15 mm.

[Description of Means for Solving Problems]

According to the present invention, a stable two-component developer thin layer can be formed by pressing a rigid magnetic rod member, which is similarly rigid, onto a rigid developer carrier as a developer amount regulating member.

In the present invention, having rigidity means having a large rigidity, that is, having a rigidity of 10 ⁴ kg / cm ² or more, specifically (0.8 to 1.6) × 10 ⁶ kg / cm ^2. (1.0 to 10) × 10 ⁴ kg / c containing various magnetic metals, including iron and its alloys, having a degree of rigidity, and magnetic powder
A hard resin having a rigidity of about m ^{2 is} also used as the developer amount regulating body of the present invention. Also, iron and iron alloy plated with chromium or the like may be used.

Also, having magnetism means having a property of being attracted to a magnet.

 The present inventors conducted the following experiment.

Using an experimental apparatus as shown in FIG. 1, layers were formed with magnetic and non-magnetic cylindrical rods 50. That is, the magnet roller 4 having a plurality of magnetic poles was fixed, and the developing sleeve 3 was rotated on the outside thereof in the direction indicated by the arrow. This developing sleeve 3
The cylindrical bar 50 was pressed using a spring burr. The pressing position of the cylindrical bar 50 was a position facing the magnetic pole of the magnet roller 4. When the parameters were the pressing force of the cylindrical bar 50 and the diameter of the cylindrical bar, a graph as shown in FIG. 2 was obtained for the transport amount. Here, in the case of a non-magnetic cylindrical bar, the pressing force is obtained by adding the load F of the spring burr and the own weight of the cylindrical bar, and in the case of the magnetic cylindrical bar, the attraction force due to the magnetic force is further added. In the figure, the curve shown by the solid line shows the case of a magnetic cylinder, and the curve shown by the chain line shows the case of a non-magnetic cylinder.
As is clear from the figure, the transport amount of the two-component developer is
The balance between the force applied to the cylindrical bar by the two-component developer entering the wedge-shaped portion formed by the sleeve 50 and the sleeve 3 and the force in the sleeve direction of the cylindrical bar pressed by a spring or a spring and a magnetic force. Indicates that it will be determined. In addition, in the case of the magnetic cylindrical rod, the transport amount of the two-component developer is more stable with respect to the fluctuation of the pressing force than the non-magnetic cylindrical rod.
Non-magnetic SUS such as SUS310, Al, or polycarbonate is used as the material of the cylindrical rod 50, and SUS416 is used as the magnetic cylindrical rod 50.
The results obtained by using a hard resin containing magnetic SUS, iron alloy, and magnetic powder such as SUS430 and SUS430 are shown. In this device, the cylindrical rod is a rigid and magnetic cylindrical rod having a radius of curvature of 0.5 mm to 15 mm, preferably 1 mm to 10 mm,
When the pressing force was set to (1 to 15) gf / mm, a stable desired amount of conveyance was obtained regardless of the fluctuation of the pressing force during the operation of the apparatus. If the pressing force is too small, the regulating power of the amount of the two-component developer decreases, and stable regulation cannot be performed. Further, it is not preferable because it is easily affected by external influences such as vibration of the developing device. Agglomerates of the two-component developer are also passed through, and a uniform two-component developer layer cannot be formed.

If the pressing force is too high, the load on the two-component developer becomes large, and remarkable adhesion of the two-component developer component is observed in the vicinity of the regulating portion of the regulating body, so that it cannot withstand long-term use. In addition, even small lumps of paper powder, rubber, and developer are clogged in the regulating portion, and white stripes are easily generated.

The selection of the pressing force is (1-15) gf / m from the above various viewpoints.
m is appropriate and (2 to 10) gf / mm is particularly preferable. In the case of a two-component developer using a magnetic spherical carrier as described in Table 1, the above range is optimal for the pressing force. As a result, an image with no unevenness and a stable density was obtained.

As means for pressing the cylindrical rod in the sleeve direction,
It is preferable to use a non-linear elastic member having a characteristic that the load (repulsive force) does not easily change with respect to the amount of deflection in the use range including before and after the use state. An example of a characteristic curve of a nonlinear elastic member having such characteristics is shown in FIG.
FIG. Shown are the four POs with slightly different performance.
In the characteristic curve of RON (trade name of INOAC), when the amount of deflection is plotted on the horizontal axis and the load is plotted on the vertical axis, a stable range with a gentle inclination is shown in the use range U.

By using a non-linear elastic member that presses in this range of use as a pressing member for the cylindrical bar, even if there is an error in the accuracy of the parts of the casing or the holder or a variation due to the assembly state of the developing device, the variation is absorbed and the cylindrical bar is absorbed. The variation in the pressing force on the sleeve is small, and the layer thickness of the two-component developer is kept uniform.

That is, it was confirmed that a very stable transport amount and a uniform thin layer could be formed as compared with a developing device having a conventional developer amount regulating body.

Note that a coating may be provided on a rod-shaped developer amount regulating member such as a cylindrical rod or the like, or a coating of polyurethane rubber or silicone rubber may be provided as long as the effects of the present invention are not lost.

〔Example〕

Based on the above results, an embodiment of a developing device to which the present invention is applied will be described first with reference to FIG.

Embodiment 1 FIG. 3 shows a cross section of a main part of the developing device, and FIG.
Is an image carrier, 2 is a housing, 3 is a developing sleeve, 4 is a magnet roller, 5 is a rigid and magnetic rod-like body (cylindrical rod) for regulating the amount of the two-component developer, and 15 is a cylindrical rod 5
Is a spring material for allowing the two-component developer to be conveyed by pressing the cylindrical bar 5 and the developing sleeve 3. The cylindrical bar 5 is a two-component developer with respect to the developing sleeve 3. Is pressed with a constant load without intervening. 7 and 8 are first and second stirring members, 9 is a supply roller, 10
Denotes a scraper, and 11 denotes a stirring partition plate.

The toner replenished in the apparatus rotates in the direction indicated by the arrow.
The upper developer D which is sufficiently stirred and mixed with the carrier by the stirring member 7 and the second stirring member 8 which rotates so as to overlap with each other in the opposite direction is sent to the developing sleeve 3 via the supply roller 9.

The first stirring member 7 and the second stirring member 8 are screw-shaped members having left-handed helical angles rotating in mutually opposite arrow directions, and are conveyed to the back side by the thrust of the second stirring member 8. The toner and the carrier are moved over the agitating partition plate 11 whose upper edge is inclined downward in the depth direction of the drawing and move to the first agitating member 7 side, and are conveyed to the near side of the drawing by the thrust thereof. The developer D is triboelectrically charged by the mixing action of the developer and the carrier, and adheres in a layer on the peripheral surface of the developing sleeve 3 by the supply roller 9 which is sponge-shaped and rotates in the direction of the arrow.

The two-component developer used in the example shown in FIG. 3 is as shown in the table below.

In this apparatus, when the cylindrical rod 5 is made of SUS having rigidity and magnetism of 6 mm and a load of (2 to 6) gf / mm is applied to the position where the cylindrical rod 5 faces the magnetic pole of the magnet roller 4, Approximately (7-9) mg / c without uniformity
A transport volume of m ² was obtained. As a result, a stable image having a uniform density was obtained. At this time, the magnetic flux density at the pressing position on the surface of the developing sleeve 3 was 600 Gauss. FIG. 4 shows a comparison between the case where a non-magnetic cylindrical rod having a rigidity of 6 mm is used in place of the magnetic cylindrical rod 5 and the amount of developer transported.

Regarding the transport amount when the rigid and magnetic cylindrical rod 5 was used, the relationship between the pressing force and the transport amount when the radius was changed as shown in FIG. 5 could be obtained. A suitable transport amount. In particular, the radius of curvature is 0.
In the case of 5 to 15 mm, a stable transport amount was obtained in which the balance between the force exerted by the developer D on the cylindrical bar 5 and the force of the cylindrical bar 5 toward the sleeve 3 was well balanced. More preferably, when the radius of curvature is 1 to 10 mm, regardless of the variation in the pressing force, the variation in the transport amount is very small, and a uniform and thin developer layer thickness can be obtained.

Although non-magnetic stainless steel was used as the material of the developing sleeve 3 having rigidity, equivalent effects were obtained by using rigid materials such as aluminum metal, hard resin, glass, and ceramics. The surface roughness of the developing sleeve 3 is 3S
Was used. The same effect was obtained even when the surface roughness was (0.1-20) S.

As described above, a uniform and stable thin developer layer in the range of 100 μm to 450 μm, preferably 150 μm to 400 μm is formed on the surface of the developing sleeve 3 for a long time.

In this embodiment, the fixed magnet roller 4 and a thin layer of developer adhered on the outer peripheral surface of the developing sleeve 3 rotating in the direction indicated by the arrow (clockwise) are fixed in the developing region 12 in the direction indicated by the arrow. The latent image on the rotating image carrier 1 is developed in a non-contact manner at intervals to form a toner image.

FIG. 6 shows a situation in which the developer layer formed in the example of FIG. 3 is standing near the developing section. Assuming that the closest distance d between the developer carrier 3 and the image carrier 1 and the height of the spikes of the developer are S, the condition d> S is satisfied in the non-contact developing system.

To this non-contact developer, a developing bias including an AC component is applied to the developing sleeve 3 from a power source (not shown), and as a result, only the toner being developed on the developing sleeve 3 is selectively transferred to the surface of the latent image. Attached.

The developer that has consumed the toner component has a high carrier ratio and is conveyed by the developing sleeve 3 to the scraper.
It is separated and collected by 10 and is again mixed with a developer having a high toner ratio.

The specifications of the components included in the embodiment shown in FIG. 3 of the developing device of the present invention are as follows.

The developing sleeve 3 is made of a thin cylindrical stainless steel material having an outer diameter of 20 mmφ and has an outer peripheral surface honed to a roughness of 3 μm, and is clockwise at 200 to 300 revolutions per minute, and 250 revolutions per minute in this embodiment. Has been rotated. Although the diameter of the developing sleeve 3 is required to be small in order to reduce the size of the developing device, the diameter of the developing sleeve 3 is limited by the magnetic force of the built-in magnet roller.
It is set to 15 to 30 mmφ. Various experiments were also conducted on the number of rotations of the developing sleeve. When the number of rotations was low, the supply amount of the developer was small, and the image density when the latent image was developed was low. For a developing sleeve having an outer diameter of 20 mm, the maximum image density increases linearly when the number of rotations is 0 to 200 rotations per minute, and becomes saturated when the number of rotations is 200 rotations per minute or more. However, when the ambient temperature is low, the maximum image density is reduced, so it is necessary to set the maximum image density with some margin.

As shown in FIG. 3, the magnet roller 4 is composed of 12 magnets of equal magnetic poles in which N and S are alternately arranged at equal intervals, but forms a repulsive magnetic field at a portion where the scraper 10 contacts, In order to facilitate the peeling of the developer, one pole is removed to make 11 poles, and is enclosed in the developing sleeve 3 in a fixed state. The magnetic force of each magnet is preferably large in order to suppress the carrier from adhering to the image carrier 1. However, depending on the shape of the magnet roller, the maximum magnetic flux density in the normal direction on the circumferential surface of the developing sleeve 3 is limited due to manufacturing limitations. Is maintained at about 600 Gauss in this embodiment. The magnet roller 4 is made of ferrite.

The relative position between the developing sleeve 3 and the cylindrical bar 5 is a position facing the magnetic pole of the magnet roller 4 as shown in FIG.
The cylindrical rod 5 is pressed by the developing sleeve 3 and is attracted by the attracted magnetic force to increase the pressing force.
It works so that it adheres evenly.

When the rigid and magnetic cylindrical rod 5 is used as the layer thickness regulating member in the above-described embodiment, the toner stuck to the layer thickness regulating member in white streaks or continuous copying due to developer aggregation,
It was confirmed that excellent image quality with excellent reliability without image quality deterioration was obtained. In addition, it was confirmed that the above-mentioned effects are superior in the case of a magnetic cylindrical rod than in a non-magnetic cylindrical rod. The cylindrical rod having magnetism described above may be magnetized and attracted to the developing sleeve 3 side, or may be magnetized and act to be attracted.

As can be seen from Example 1, the important factor that determines the amount of developer transported by the rigid and magnetic developer amount regulating member pressed against the developer carrier is the curvature thereof as long as a rigid and magnetic cylindrical rod is used. And pressing force. Accordingly, examples of various other developer layer regulating members for giving the curvature and the pressing force are shown in FIGS. 7 to 13.

FIG. 7 shows an example in which the cylindrical bar 5 is held and pressed by the leaf spring 16. FIGS. 8 (a) and 8 (b) show that the pressing force of the leaf spring 16 can be partially adjusted by the adjusting screw 61. This is an example. The leaf spring 16 'is integral with the cylindrical bar 5 in the axial direction,
Any of those partially divided by slits and those completely divided can be suitably implemented.

FIG. 9 shows an embodiment in which the coil spring 17 applies a pressing force. In this example, a semi-cylindrical rod 5a using only the vicinity of the pressing portion of the cylindrical rod 5 is used. A plurality of coil springs 17 are arranged in the axial direction of the semi-cylindrical bar 5a to obtain a desired pressing force.

FIG. 10 is an example in which a rubber-like elastic body 18 is compressed to obtain a pressing force. The present invention can be similarly applied not only to a rubber-like elastic body but also to a resin foam.

FIG. 11 shows a cylindrical rod 5 as in FIGS.
Compressed by the compression spring 19.

FIG. 12 shows a rod-shaped developer in which the pressing portion has rigidity and magnetism and has a radius of curvature of 6 mm, and an edge portion is provided on the upstream side of the pressing portion, and the edge portion regulates the developer layer to a predetermined thickness in advance. This is the quantity regulator 5b. The pressing portion in FIGS. 11 and 12 is made of a material using a material having rigidity and magnetic poles, and is configured to press at a position corresponding to the magnetic pole on the developing sleeve 3 or in the vicinity thereof. It is possible.

In FIG. 13, the pressing portion has a two-layer structure, and the outside of the cylindrical rod 5 is covered with a thin rubber material 5 'such as urethane rubber or silicon rubber.

The thickness of the rubber material showing the pressing part of the developer amount regulating body is 0.
It is preferably from 01 to 1 mm.

Embodiment 2 In this embodiment, the same device as that of the developing device shown in FIG. 3 is used, but the rotation direction of the developing sleeve 3 is the same in the portion facing the image carrier 1. In this case, the cylindrical rod 5, which is a developer amount regulating body, is disposed at a position as shown in FIG. The developing sleeve 3 is made of non-magnetic stainless steel having a surface roughness of 1S (diameter 30).
φmm), the magnet roller 4 has a sleeve surface magnetic flux density
An 8-pole with 700 gauss was used. The cylindrical rod 5 has a diameter of 7φm
a stainless steel SUS416, which is rigid and magnetic, and is disposed near the magnetic pole of the magnet roller 4 and has a non-magnetic pressing leaf spring 6
And the holder 15. The parts not described in FIG. 14 of this embodiment are configured in the same manner as the parts described in FIG. 3 of the first embodiment. The cylindrical bar 5 is a device made of a columnar magnetic material, magnetizes the magnetic material by a magnetic field generated by the fixed magnet roller 4 in the developing sleeve 3, and obtains a pressing force by a magnetic attractive force. Since the cylindrical bar 5 presses the developing sleeve 3 with magnetic attraction uniformly distributed in the longitudinal direction, an extremely good developer layer can be obtained.

Embodiment 3 FIG. 16 is a cross-sectional view of a main part of a developing device showing a third embodiment, and the same functional parts as those in FIG. 3 are indicated by the same part numbers. This embodiment is an example in which a non-linear elastic body is used as a pressing member.

The developing sleeve 3 has an outer diameter rotating at 250 rpm in the direction indicated by an arrow.
This cylinder is made of non-magnetic stainless steel with a diameter of 20 mm. Inside the developing sleeve 3, there is a magnet roller 4 having 11 poles fixed and positioned, and the maximum magnetic flux density is maintained at 600 gauss on the surface of the developing sleeve.

At a position facing the magnetic pole of the magnet roller 4, a rigid and magnetic cylindrical rod 5 is pressed against the developing sleeve 3. The cylindrical rod 5 is made of magnetic SUS416 and is a straight rod having a diameter of 6 φmm and having excellent straightness. The surface asara is grinded to 0.5S without a surface coating. The cylindrical bar 5 is restricted from moving laterally by a holder 35 attached to the housing 2, and is pressed by a non-linear elastic member 36 in the pressing direction. The nonlinear elastic member used in this embodiment has a characteristic in which the repulsion force does not easily change with respect to the amount of deflection in the range of use, and a PORON having the characteristic shown in FIG.
Is used. In this embodiment, two plate-like nonlinear elastic members 36 each having a thickness of 2 mm and a length of 4 mm and a width of 5 mm are adhered to the holder 35, and the cylindrical bar 5 is pressed. Figure 17 shows the holder
This shows a state in which the non-linear elastic member 36 is attached to 35, and is pressed at two points where the entire length of the cylindrical bar 5 is divided into n: m: n = 2: 5: 2. When the pressing force of 2 to 4 gf / mm is set under such a condition, the bending of the cylindrical bar 5 due to the pressing can be reduced, and 7 to 10 mg is uniformly applied over the entire area of the developing sleeve 3 in the axial direction. A two-component developer regulated to a developer amount of / cm ² was conveyed. Further, in this embodiment, the above-mentioned favorable developing conditions were set and maintained without providing an adjusting portion for regulating the transport amount of the developer.

As the non-linear elastic member 36, SORBOTHANE (manufactured by Sanshin Kosan Co., Ltd.), α-gel, or the like is used in addition to the urethane foam PORON, and a malt plane, a non-linear spring, or the like can also be used.

The method of pressing the cylindrical bar 5 by the non-linear elastic member 36 is also effective in reducing the bending of the cylindrical bar 5 by the two-point supporting method described in the above embodiment. It is also possible to press by. However, when using such a pressing method, it is necessary to pay sufficient attention to the accuracy of the components of the holder 35 and the degree of parallelism.

In the above embodiment, the surface roughness of the developing sleeve 3 is 3
S, the surface roughness of the cylindrical bar 5 was 0.5S. The surface roughness of the cylindrical rod 5 is desirably close to a mirror surface of 0.5 or less. On the other hand, the surface roughness of the developing sleeve 3 is required to be rough from the viewpoint of securing a necessary amount of developer transport. The surface roughness of 3 is preferably rougher (larger) than the surface roughness of the cylindrical rod 5. In addition, the surface roughness of the developing sleeve 3 tends to be gradually smoothed by the use for a long time, and the transport amount of the developer tends to gradually decrease. In order to prevent this, it is desirable that the surface hardness of the developing sleeve 3 is high, and according to experiments, it is desirable that the cylindrical rod 5 also has the same high hardness.

 The embodiment has been described above.

In the embodiments of the present invention, the cylindrical rod is mainly used for the developer amount regulating body.However, without being limited to these, at least the pressing portion has rigidity and magnetism, and its curvature radius is 0.5 to 15 mm.
Any rod-shaped body is acceptable.

The developing conditions and developer components used in the present invention include the following. In the developing device of the present invention, the distance between the developing sleeve 3 and the image carrier 1, that is, the value of d in FIG.
It is preferably from m to 0.6 mm. Reducing the distance between the developing sleeve 3 and the image carrier 1 increases the electric field effect and adjusts the direction of the lines of electric force, so that the image does not blur during development. When the average value is 0.5 mm, the height of the developer spike becomes 200 μm to 450 μm by selecting the multi-pole magnet roller as described above. S is 0.02mm ~ 0.3mm
That is, a value corresponding to (0.1 to 0.6) × d can be maintained.

The developer used in the present invention is a two-component developer. This is presumably because the carrier has a function of self-cleaning the developer component adhering to the regulating body, so that a more stable developer layer can be formed for a longer period than in the case of a one-component developer. Examples of the two-component developer include a non-magnetic toner having a particle size of 6 μm to 18 μm,
Particle size of ferrite core coated with resin material is 10μm ~ 100
A developer comprising a carrier having a size of μm (preferably 30 μm to 60 μm) is preferably used in a developing device to which the present invention is applied. The toner will be described below.

Thermoplastic resin (binder) (80-90) wt% Example: Polystyrene, styrene-acrylic polymer, polyester, polyvinyl butyral, epoxy resin, polyamide resin, polyethylene, ethylene-vinyl acetate copolymer, or a mixture of the above pigments (Colorant) 0 to 15 wt% Example: Black: carbon black Yellow: benzidine derivative Magenta: rhodamine B lake, carmine 6B, etc. Cyan: copper phthalocyanine, sulfonamide derivative dye, etc. Charge control agent 0 to 5 wt% plus toner: nigrosine-based Electron-donating dyes, alkoxylated amines, alkylamides, chelates, pigments, 4
Negative toner: electron-accepting organic complex, chlorinated paraffin, chlorinated polyester, acid-excess polyester,
Chlorinated copper phthalocyanine, etc. Fluidizing agent Examples: Colloidal silica, hydrophobic silica, silicone varnish, metal soap, nonionic surfactant, etc. Cleaning agents (prevents filming of toner on photoreceptor) Examples: fatty acid metal salts, Silicon oxide with organic groups on the surface,
Fillers (improve surface gloss of images, reduce raw material costs) Examples: Calcium carbonate, clay, talc, pigments, etc. In addition to these materials, to prevent fogging and toner scattering on the image surface, A small amount of magnetic powder may be contained.

Examples of such magnetic powder include triiron tetroxide, γ-ferric oxide, chromium dioxide, nickel ferrite, and iron alloy powder having a particle size of 0.1 μm to 1 μm, and (0.1 to 5) wt.
%. In order to maintain a clear color, the content is desirably 1 wt% or less.

Adhesive resins such as wax, polyolefins, ethylene-vinyl acetate copolymer, polyurethane, and rubber are used as the resin suitable for pressure fixing toner that is plastically deformed with a force of about 20 kg / cm and fixed to paper. Can be

On the other hand, the surface potential on the image carrier 1 side is -600 V, the exposure section potential is 0 to -100 V, and the developing sleeve 3 has a DC bias of -500 V, an AC bias of 700 V (rms), and a frequency of 4 kHz.
When the development was attempted under the condition that the voltage of z was applied, it was confirmed that a high-quality toner image with a high resolution and a uniform gradation was obtained.

〔The invention's effect〕

As described above, the developing device of the present invention presses the developer amount regulating body formed of a magnetic member having the same rigidity and magnetism and having a small radius of curvature on a rigid developer carrier to thereby charge the developer. By forming the layer forming portion, it is not affected by changes in the rotation speed and the pressing position of the developer carrier, and is particularly rich in the stability of the transport amount with respect to the pressing force fluctuation,
A developer layer having a stable thickness can be obtained. Therefore,
As a result, a uniformly stable developer layer can be obtained with a lower load compared to the conventional one.

Further, the particles are less likely to be clogged by foreign substances, and the crushability of the aggregated toner and the developer mass is excellent, and white streaks are hardly generated in an image. Also, the fluctuation in the amount of developer after the regulation due to the change in the pressing force of the developer amount regulating member at the pressing portion against the developer carrier is extremely small, and a developing device having excellent developability can be obtained. Thus, it is possible to stably form a thin layer without unevenness, and to provide an image of excellent quality without causing unevenness in density and a decrease in density.

Since the developing device of the present invention does not deform when the regulating member is used for a long period of time and changes in the attraction force due to the magnetic force are small, the durability as the regulating device is extremely large. Furthermore, even in mass production, the tolerance of the mounting accuracy is relatively large, and it is rich in practicality.

In addition, since the developer regulating area is small, adverse effects due to unnecessary triboelectric charging with the developer hardly occur, and a good image can be obtained.

In addition, when replacing the regulating member,
Easy installation and high maintainability.

In addition, when a non-linear elastic member is used as the pressing member of the cylindrical bar, errors in component accuracy of the casing and the holder and variations during assembly are absorbed, so that even if there is no adjustment portion, stable and good development is always achieved. A developing device capable of transporting the amount of the agent has been provided.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an experiment on which the present invention is based. FIG. 2 is a view showing the relationship between the presence / absence of magnetism, the curvature of the pressing portion, the pressing force, and the conveyance amount obtained by the experiment of FIG. FIG. 3 is a block diagram showing the first embodiment, and FIGS. 4 and 5 are relational graphs obtained by the same. FIG. 6 is an explanatory diagram of the development between the image carrier and the developing sleeve. FIG. 7 to FIG. 13 are main part views showing another application example of the first embodiment. FIG. 14 is a configuration diagram showing a second embodiment. FIG. 15 is a graph showing the relationship between deflection and load for an example of a nonlinear elastic body. FIG. 16 is a block diagram showing a third embodiment, and FIG. 17 is a perspective view of a main part thereof. DESCRIPTION OF SYMBOLS 1 ... Image carrier, 3 ... Developing sleeve 4 ... Magnet roller 5 ... Bar-shaped body (cylindrical bar) 6 ... Spring material, 15, 35 ... Holder 36 ... Nonlinear elastic member

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Toshiro Fujimori 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (72) Inventor Masayuki Kamegamori 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (72) Inventor Mitsuo Sugizaki 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation Examiner Masao Shinda (56) References JP-A-60-46577 (JP, A) JP-A-62-75479 (JP, A) 3860 (JP, U)

Claims (1)

(57) [Claims] 1. A fixed magnet body, and a developer carrier having the magnet body therein and having a rigidity of 10 ⁴ kg / cm ² or more and carrying a two-component developer on a surface thereof; A rod-shaped developer amount regulating body that is pressed against the carrier against the magnet and regulates the amount of the two-component developer carried on the carrier; and the carrier of the regulator is provided. The pressing part is a material having a rigidity of 10 ⁴ kg / cm ² or more and a magnetic property, and has a radius of curvature.
A developing device for a two-component developer, which is 0.5 to 15 mm.