JPH03100575A - Developing device - Google Patents

Abstract

PURPOSE:To stably obtain a thin layer of a toner by placing opposingly a toner holding body in a developer holding body for holding and carrying a two-component developer and respectively specifying positions of a toner control member and a magnetic pole for forming a magnetic field in an opposed part in the developer holding body. CONSTITUTION:A toner holding roller 6 is provided so as to be opposed to a developer holding roller 1 provided in a developing container 7 in which a two-component developer 9 is contained, and in the developer holding roller 1, a magnet roller 2 is installed so as to be immovable against a rotation of the roller 1. Subsequently, an elastic blade 8 is provided so as to come into contact with a magnetic brush of the developer 9 formed on the developer holding roller 1 by a magnetic pole S1 of the magnet roller 2, in the downstream side in the rotating direction of the toner holding roller 6 against an opposed part Q to the developer holding roller 1. Also, the magnetic pole S1 is positioned in the part of the downstream side in the rotating direction of the developer holding roller 1 against an elastic blade 8 of the opposed part Q to the toner holding roller 6. In such a way, a thin layer of a toner 4 can stably be obtained extending over a wide range of toner concentration against a carrier 3.

Description

[Detailed Description of the Invention] No. 1 The present invention relates to a developing device using a two-component developer having toner and a carrier, and particularly to a developing device that makes it possible to satisfactorily form a thin layer of toner on a developer carrier. It relates to a developing device.

1. As a developing device using a two-component developer containing toner and carrier (magnetic particles), there is known a developing device disclosed in Japanese Patent Application Laid-open No. 116240/1983.

In such a developing device, a two-component developer including toner and carrier is stirred by a stirring means to triboelectrically charge the toner.
The charged toner from the developer is attached to a conductive roller, carried on it, and conveyed to a development position between the image carrier and the conductive roller is biased with a polarity opposite to the charged polarity of the toner. An electric field is applied by a bias power source to adhere toner to the electrostatic latent image formed on the image carrier, and the electrostatic latent image is visualized as a toner image.

However, in this type of developing device, if the toner concentration of the developer becomes higher than permissible, the amount of toner adhering to the conductive roller will be excessively large, causing image fogging and toner scattering. This causes the inconvenience of

Another example of a developing device using a two-component developer includes a developing sleeve as a developer carrier with a built-in magnetic field generating means, and an image carrier that is in contact with the circumferential surface of the developing sleeve to regulate the carrier. A device is known in which an elastic blade is provided to apply toner to a predetermined thickness to be conveyed to a developing position, as disclosed in, for example, Japanese Patent Laid-Open No. 62-96956.

In this developing device, an elastic blade is brought into elastic contact with the developing sleeve, and the toner is agitated by circulating carrier near the blade, so that the toner is coated with a sufficient amount of so-called tribo. .

However, in order to circulate the carrier sufficiently, sufficient space is required, and the amount of carrier must be kept small to obtain the tribo. The existence rate of carriers must be 10% or less. As a result, with such a small amount of carrier, the amount of toner conveyed is insufficient, and the toner cannot be sufficiently conveyed to the development position, resulting in a problem that a so-called ghost phenomenon occurs.

In addition, in devices where the elastic blade itself is made of a magnetic material and uses magnetic force to regulate the carrier, an immobile layer of carrier is created near the blade, making it difficult to circulate the carrier and supply toner to the developing sleeve. becomes insufficient,
As expected, there was a problem of a ghost phenomenon occurring.

For these reasons, it is possible to apply a thin layer of applied toner over a wide range of toner concentrations to the carrier of a two-component developer using a simple configuration that does not require a toner concentration control mechanism. It is possible to easily obtain high-density, high-quality images that are stable, do not cause fogging or toner scattering, and do not leave any history of previous development, and also allows for inexpensive and compact equipment. Development of a developing device is desired.

Therefore, an object of the present invention is to provide a developing device having the above characteristics.

of ruta The above object is achieved by a developing device according to the present invention.

In summary, the present invention provides a developer carrier that supports a two-component developer including toner and a carrier and transports the developer, and a developer carrier disposed opposite to the developer carrier. a toner carrier that receives, carries, and conveys the toner in the developer by contacting the developer carried on the body; and a portion of the toner carrier facing the developer carrier;
a toner regulating member that is brought into contact with the toner carrier at a downstream position in the rotational direction and that regulates the amount of toner carried on the toner carrier, and a magnetic pole that forms a magnetic field in the opposing portion; The developing device further includes a magnet disposed within the developer carrier and located downstream in the rotational direction of the developer carrier from a position of the contact portion of the toner regulating member.

According to one aspect of the present invention, the toner regulating member is made of an elastic blade, and the elastic blade is disposed to face in a direction opposite to the toner conveyance direction. According to another aspect of the present invention, a DC electric field or an AC electric field superimposed thereon is formed between the developer carrier and the toner carrier.

and i] Examples of the present invention will be described in detail below.

FIG. 1 is a schematic diagram showing an embodiment of the developing device of the present invention.

As shown in FIG. 1, the developing device of the present invention faces a developer carrying roller 1 as a developer carrying member that rotates in six directions and is disposed in a developing container 7 containing a two-component developer 9. A toner carrying roller 6 as a toner carrying member that rotates in the direction B is provided, and an elastic blade 8 that comes into contact with the toner carrying roller 6 is provided.

The developer 9 is a mixture containing the toner 4 and the carrier 3 made of magnetic particles having a larger diameter than the toner 4. A magnetic or non-magnetic doctor blade 5 that regulates the amount of developer 9 applied onto the roller 1 is arranged at the top of the developer carrying roller 1 with an interval from the roller 1. A magnet roller 2 serving as a magnetic field generating means is installed inside the developer carrying roller 1 so as to be immovable with respect to the rotation of the roller 1.

The toner carrying roller 6 is connected to the photosensitive drum 1 as an image carrying member.
The developer container 7 is disposed at the opening of the developer container 7 facing the roller 1, and is disposed close to the roller 1 so as to be in contact with the developer 9 carried by the roller 1 at a portion Q facing the developer carrying roller 1. .

The elastic blade 8 is configured to absorb the magnetism of the developer 9 formed on the developer carrying roller 1 by the magnetic pole S1 of the magnet roller 2 on the downstream side in the rotational direction of the toner carrying roller 6 from the facing portion Q of the developer carrying roller 1. It is provided so as to be in contact with the brush, and is inclined from above with respect to the direction in which the toner is conveyed by the roller 6 (rotation direction of the roller 6), and is brought into contact with the roller 6 in a counter direction. The elastic blade 8 is deformed as shown in the figure by the pressure applied to the toner carrier roller 6, and is urged such that the tip of the blade 8 comes into contact with the roller 6.

The magnet roller 2 has N1 and S in the rotational direction of the roller l.
It has four magnetic poles of t, Nz, and Ss, and the magnetic pole S1 is
It is located on the downstream side of the elastic blade 8 in the rotational direction of the developer carrying roller 1 in the portion Q facing the toner carrying roller 6 .

Next, the operation of the present developing device will be explained.

The two-component developer 9 accommodated in the developing container 7 forms a circulating flow C by the action of the rotational force of the developer carrying roller 1, the magnetic force of the magnet roller 2, and gravity, and the action of this circulating flow C and the action of the developing container Stirring member 13 provided at the lower part of 7
By this action, the carrier 3 and the toner 4 in the developer 9 are mixed and stirred, and furthermore, the toner 4 is charged by frictional charging.

The mixed and stirred developer 9 is transferred to the developer carrying roller 1.
A regulated amount is applied and supported by the doctor blade 5. The remaining developer 9 regulated by the doctor blade 5 is returned into the developer container 7 and incorporated into the circulating flow C of the developer 1 again to be stirred and mixed.

In this embodiment, a doctor blade 5 and a developer carrying roller 1 are used.
The gap between the two is set to 800 μm. Further, in order to stabilize the amount of developer 9 applied onto the developer carrying roller 1, the magnetic pole Nl of the magnet roller 2 is positioned at the location of the doctor blade 5. It is better to position the magnetic pole Nl slightly inclined at an angle θ on the upstream side in the rotational direction of the roller 1 than the position T facing the blade 5, since the developer 9
The circulating flow C can be formed more smoothly.

It is preferable that the above-mentioned angle θ is 5° to 15°.

The developer 9 coated on the developer carrying roller I is conveyed by the roller 1 to a portion Q facing the toner carrying roller 6. The magnetic pole SI of the magnet roller 2 is located at the portion Q facing the toner carrying roller 6, as described above.

Next, the state of the facing portion Q between the developer carrying roller 1 and the toner carrying roller 6 will be explained based on FIG.

The developer 9 applied and carried on the developer carrying roller 1 as described above is conveyed to the portion Q facing the toner carrying roller 6 by rotation of the roller I in the direction of arrow A. In this opposing portion Q, due to the action of the magnetic field (the lines of magnetic force are indicated by f in FIG. 2) formed by the magnetic pole S of the magnet roller 2,
The spikes 32 of the magnetic brush are formed on the developer 9 carried on the developer carrying roller l. In the spikes 32 of the magnetic brush, when the developer 9 flows in a laminar manner in the direction of rotation of the roller 1 due to the conveying force caused by the rotation of the developer carrying roller 1, the developer 9 is caused by the frictional force caused by the rotation of the toner carrying roller 6. A laminar flow C in the rotational direction of the roller 6 is generated.

One M flow C of the developer 9 is conveyed as the toner carrying roller 6 rotates, but since the elastic blade 8 is urged to contact the roller 6 as described above, the layer of the developer 9 is The developer 9 constituting the stream C, except for the toner transferred and applied to the roller 6, is bounced off the blade 8 as shown by arrow e. The repelled developer 9 becomes a circulating flow, merges with the other laminar flow, is conveyed by the developer carrying roller 1, and is returned into the developer container 7.

That is, at the contact portion between the elastic blade 8 and the toner carrying roller 6, the carrier 3 in the developer 9 forming a laminar flow C
(The illustration is enlarged for convenience of explanation) Therefore, the laminar flow of the developer 9 due to the rotation of the developer carrying roller 1 is in the forward direction with respect to the flow direction.For this reason, the return e of the carrier 3 at the contact portion merges when the developer 9 flows smoothly in a laminar manner. As a result, the developer 9 does not stagnate in the opposing portion Q between the developer carrying roller 1 and the toner carrying roller 6, and a stable flow can be formed.

In this manner, in the opposing portion Q, the toner 4 is applied onto the roller 6 while the developer 9 is rubbed against the toner carrying roller 6, and smooth flow of the developer 9 without stagnation is realized. Therefore, new developer 9 can always be supplied near the toner carrying roller 6, and a sufficient amount of toner 4 can be supplied, so that the toner 4 can be uniformly applied onto the roller 6 without leaving a history of the previous development. be able to.

Note that it is necessary to ensure that the developer 9 is not supplied relatively excessively at the opposing portion Q between the developer carrying roller 1 and the toner carrying roller 6. For this reason, in this embodiment, at the opposing portion Q, The gap was set to 700 μm.

Next, the function of the elastic blade 8 as a developer regulating member will be explained.

As described above, the elastic blade 8 is arranged so that its tip comes into contact with the toner carrying roller 6. In this manner, by bringing the tip of the elastic blade 8 into contact with the toner carrying roller 6, it is possible to scrape off excess toner 4 applied on the roller 6 and allow an appropriate amount of toner 4 to pass through.

At this time, the toner concentration of the developer 9 carried on the developer carrying roller 1 is made relatively high, so that the amount of toner 4 supplied from the roller 1 to the toner carrying roller 6 is always slightly excessive. At the same time, by removing the applied extra toner 4 and the carrier 3 conveyed at the same time with the elastic blade 8, the toner carrying roller 6
A constant amount of toner 4 can always be applied on top.

Generally, the amount of toner 4 transferred from developer carrying roller 1 to toner carrying roller 6 depends on the concentration of toner 4 in developer 9 carried on roller 1, and when the toner concentration is high, the amount of toner 4 transferred to toner carrying roller 6 increases. The amount is large, but when the toner concentration is low, the amount transferred is small (transferred to this toner carrying roller 6,
If the amount of toner applied is excessively large, it may cause image fogging or toner scattering. Therefore, it is necessary to always control the amount of toner 4 applied to the toner carrying roller 6 to an appropriate amount.

In the present invention, even if the toner concentration of the developer 9 changes greatly, an appropriate amount of toner 4 is applied to the toner carrying roller 6 by the action of the elastic blade 8, so that the above-mentioned disadvantages do not occur.

According to experiments conducted by the inventors, the toner concentration of the developer (toner weight/carrier weight x lOO (%)) is 10 to 40%.
Even in such a wide range, a certain amount of toner 4 could be applied onto the toner carrying roller 6.

Next, stabilization of toner application by the elastic blade 8 will be described in more detail.

FIG. 3 is a schematic diagram showing a contact portion of the elastic blade 8 that contacts the toner carrying roller 6. As shown in FIG.

The developer l carried on the developer carrying roller l and conveyed to the part Q facing the toner carrying roller 6 forms the magnetic brush spikes 32 as described above, and within the spikes 32 C-e.
The toner 4 is transferred and applied to the toner carrying roller 6 from the laminar flow C of the developer 9 constituting the circulating flow of e-1b. The applied toner 4 and accompanying carrier 3 are carried to the contact portion with the elastic blade 8 as the toner carrying roller 6 rotates. At this contact portion, the relatively strongly charged toner 4 of the applied toner 4 has a strong adhesion force with the toner carrying roller 6, so it contacts against the sliding force of the elastic blade 8. However, the toner 4 with a weak charge is scraped off, and the carrier 3 with a large particle size cannot pass through the gap and is similarly scraped off.

In this way, an appropriate amount of toner 4 is deposited on the surface of the toner carrying roller 6 after passing through the contact portion of the elastic blade 8.
A thin layer of toner 4 can be formed.

Here, the term "appropriate amount" refers to the amount of toner applied within a range that provides a developed image with sufficient density, no image fogging, and no scattering of toner 4 to the surroundings.According to experiments conducted by the present inventors, styrene / When using a toner whose main component is acrylic resin, the appropriate amount of toner to be applied is 0.5 to 1.2 mg/cm.
", preferably 9.7 to 1.0 mg/cm".

For details on how to set the elastic blade 8, refer to the elastic blade 8
There are two types: a type in which the ridge at the corner of the tip end is brought into pressure contact with the toner carrying roller 6, and a type in which the abdomen at the end part is brought into pressure contact with the toner carrying roller 6. In the case of the former type, as shown in FIG. 4, if the elastic blade 8 is set too high relative to the toner carrying roller 6, all of the applied toner 4 will be stripped off. In the case of the latter type, as shown in FIG. 5, if the tip of the elastic blade 8 lifts up too much from the toner carrying roller 6, the lifted area 11 is likely to be clogged with the carrier 3, resulting in uneven coating. Therefore, it is necessary to urge the tip of the elastic blade 8, that is, the tip and the vicinity thereof, so as to come into contact with the toner carrying roller 6.

FIG. 6 is an explanatory diagram illustrating the amount of penetration of the elastic blade 8.

In FIG. 6, the dotted line indicates the position of the tip of the elastic blade 8 assuming that the toner carrying roller 6 is not present, and the solid line indicates the actual position of the elastic blade 8 when the toner carrying roller 6 is present. It shows.

Intrusion amount g of elastic roller 8 into toner carrying roller 6 The length between the corner R on the roller 6 side) is 0.5 to 2 mm in order to urge the tip of the elastic blade 8 (the tip and its vicinity) to contact the toner carrying roller 6. is preferred.

As for the material of the elastic blade 8, it is preferable to use a material that can regulate the carrier 3 and also impart a charge of a desired polarity to the toner 4 through friction when it comes into contact with the toner 4.

Although it depends on the material of the toner, for example, ethylene propylene, fluororubber, natural rubber, polychlorobutadiene, N, B, R, etc. are effective for positively charging a toner whose main component is polystyrene. . On the other hand, silicone rubber, polyurethane, styrene-butadiene rubber, etc. are effective for negatively charging.

Note that the hardness of the rubber described above is preferably 50 to 70 degrees in terms of JISA hardness. If it exceeds 70@ in JISA, the elasticity of the rubber becomes too strong (the pressure at the contact part becomes too high, and the thin layer of toner 4 formed on the toner carrying roller 6 becomes excessively thin, resulting in insufficient The density of the image will not be obtained. On the other hand, if it is less than 50", the rubber itself will be weak and it will be difficult to obtain sufficient pressure to place the contact portion.

As the carrier 3 used in this example, conventionally known ferromagnetic or paramagnetic particles can be used, such as metal particles of iron, chromium, nickel, cobalt, etc., triiron tetroxide, gamma ferric oxide, etc. Metal oxides such as iron, chromium dioxide, manganese oxide, and ferrite, alloys such as manganese and copper alloys, resin carriers in which the above magnetic particles are dispersed in resin materials, and coated carriers in which the above magnetic particles are coated with resin materials. Can be used. Further, since the carrier 3 is not applied to the surface of the toner carrying roller 6, it is possible to use either a conductive carrier or an insulating carrier.

Regarding the particle sizes of the carrier 3 and toner 4, in order to reliably regulate the carrier 3 by the above-mentioned elastic blade 8, the particle size of the toner 4 is 1 to 20 μm, and the particle size of the carrier 3 is in the range of 40 to 200 μm. It is preferable that there be. If the particle size of the carrier 3 is less than 40 μm, it will be difficult to control the carrier 3 by the elastic blade 8, and if it exceeds 200 μm, the ability to hold the toner 4 on the toner carrying roller 6 will be significantly reduced.

In addition, it is preferable to add minute irregularities to the surfaces of the developer carrying roller 1 and the toner carrying roller 6 rather than making them mirror-finished in order to uniformly apply the toner 4. Furthermore, in order to control the charge imparting ability, it is preferable to add minute irregularities to the surfaces. Alternatively, a resin or a resin in which conductive particles such as carbon are dispersed may be applied.

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

In the developing device of this embodiment, the magnet roller 12 is installed immovably within the toner carrying roller 6, and the contact portion of the elastic blade 8 at the opposing portion Q between the developer carrying roller 1 and the toner carrying roller 6 is The lI! of the magnet roller 12 is located upstream of the toner carrying roller 6 in the rotational direction. It is characterized by having three locations on the north and north poles. The other structure of the developing device of this embodiment is basically the same as that shown in FIG. 1, and the same reference numerals in FIG. 7 as in FIG. 1 indicate the same members.

Next, the state of the facing portion Q between the developer carrying roller 1 and the toner carrying roller 6 in this embodiment will be explained based on FIG. 8.

In the same manner as in the previous embodiment, the developer 9 applied and carried on the developer carrying roller 1 is conveyed to the portion Q facing the toner carrying roller 6 by the rotation of the roller 1 in the direction of arrow A. .

In this opposing portion Q, a substantially parallel magnetic field (as shown in FIG. Lines of magnetic force (indicated by broken lines f) act on the developer 9 carried on the developer carrying roller 1 as a perpendicular force to the surface of each roller 1.6, and this and the conveying force due to the rotation of the roller 1.60. As a result, a laminar flow of the developer 9 is generated. In the vicinity of the developer carrying roller 1, there is a laminar flow in the direction of rotation, and in the vicinity of the toner carrying roller 6, a laminar flow in the direction of rotation similarly occurs.

One laminar flow C of this developer 9 is conveyed as the toner carrying roller 6 rotates, as in the previous embodiment, and the elastic blade 8 is urged to contact the roller 6. Therefore, the developer 9 constituting the laminar flow C, except for the toner transferred and applied to the roller 6, is bounced off at the position of the blade 8 as shown by arrow e. The repelled developer 9 becomes a circulating flow, joins the other laminar flow, is conveyed by the developer carrying roller 1, and is returned into the developer container 7.

That is, at the contact portion between the elastic blade 8 and the toner carrying roller 6, the carrier 3 in the developer 9 forming a laminar flow C
(As in the previous embodiment, the illustration is enlarged for convenience of explanation) The direction of the magnetic force acting on the magnet roller 2
This is the direction of the resultant force of the magnetic force caused by the magnetic pole S1 and the magnetic force caused by the magnet roller N3. The magnetic pole Sl is an elastic blade 8
Since the magnetic pole N is located downstream in the rotational direction of the developer carrying roller 6 from the abutting part, and the magnetic pole N is located upstream in the rotational direction of the toner carrying roller 6 from the abutting part. The direction of the magnetic force acting on the carrier 3 in the developer 9 constituting the laminar flow C is in the forward direction with respect to the laminar flow direction of the developer 9 as the developer carrying roller 1 rotates. For this reason, the return e of the carrier 3 at the abutting portion smoothly flows laminarly and merges, and as a result, the developer 9 does not stagnate in the opposing portion Q between the developer carrying roller 1 and the toner carrying roller 6. , it becomes possible to form a stable flow.

In this embodiment, in this way, the magnetic pole S of the magnet roller 2 in the developer carrying roller 1 and the magnetic pole N of the magnet roller 12 in the toner carrying roller 6 ensure smooth operation without retention in the opposing part Q. Circulating flow of developer 9 (
C→641) ) can be formed.

According to such a circulating flow of the developer 9, the toner 4 in the developer 9 is sufficiently charged, and the developer 9 and the toner carrying roller 6 are brought into strong contact, so that a sufficient amount of toner 4 is transferred to the roller. 6.

Furthermore, there is also an action of loosening the residual toner that has not been subjected to development and has been collected while remaining on the toner carrying roller 6, and replacing it with new toner, so that the history of the previous development is not left behind.

Note that the strength of the magnetic force of the magnetic poles S, N, is S
> N x, and in this example, S,
= 600 Gauss and N5 = 300 Gauss.

FIG. 9 is a schematic diagram showing still another embodiment of the developing device of the present invention.

In the developing device of this embodiment, in order to form a DC electric field or an AC electric field superimposed thereon at the facing portion Q between the developer carrying roller 1 and the toner carrying roller 6, an AC power supply 14 and an AC electric field are connected between these rollers 1 and 6. The feature is that a DC power supply 15 is inserted in series.

The other structure of the developing device of this embodiment is basically the same as that shown in FIG. 1, and the same reference numerals in FIG. 9 as in FIG. 1 indicate the same members.

To give an example in this embodiment, when a negatively charged toner is used as the toner 4 of the developer 9, s o OV(7)
A voltage obtained by superimposing an AC voltage of 1600Hz% 100OVp-p on a DC voltage is applied to the toner carrying roller 6,
An alternating current electric field is formed at the facing portion Q of the roller 1.6.

According to this, since an alternating current electric field is formed in the opposing portion Q of the developer carrying roller 1 and the toner carrying roller 6, the toner 4 is transferred from the developer 9 on the developer carrying roller 1 to the toner carrying roller 6. can be carried out satisfactorily. Furthermore, by adjusting the magnitude of the applied voltage, the amount of transferred toner can be controlled, and furthermore, by forming a reverse electric field, it is also possible to peel off the toner 4 on the toner carrying roll 6.

In the above description, an alternating current electric field with a direct current electric field superimposed was formed at the facing portion Q of the developer carrying roller 1 and the toner carrying roller 6. However, by applying only a direct current voltage to the toner carrying roller 6, Alternatively, a direct current electric field may be formed in the opposing portion Q. This also provides the same effect as described above.

As explained above, in the developing device of the present invention, the toner carrier is disposed opposite to the developer carrier carrying and conveying the two-component developer, and the developer carrier of the toner carrier is A toner regulating member is disposed in contact with the downstream position of the toner carrier in the rotational direction, and a magnetic pole that forms a magnetic field in the opposing portion of the magnet disposed inside the developer carrier is connected to the toner regulating member. Since it is located downstream in the rotational direction of the developer carrier from the abutment position of the developer carrier, it has a simple configuration that does not require a toner concentration control mechanism, and can be used over a wide range of toner concentrations with respect to the carrier of the two-component developer. By stably obtaining a thin layer of applied toner, it is possible to easily obtain high-density, high-quality images without fogging or toner scattering (and without leaving any history of previous development). It also becomes possible to reduce the cost and size of the device.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the developing device of the present invention. FIG. 2 is an explanatory diagram showing the state of the opposed portion between the developer carrying roller and the toner carrying roller in the developing device shown in FIG. FIG. 3 is a schematic diagram showing a contact portion of an elastic blade that contacts a toner carrying roller in the developing device shown in FIG. 1. FIG. FIG. 4 and FIG. 5 are explanatory diagrams each showing a contact mode of the elastic blade of FIG. 3. FIG. 6 is an explanatory diagram showing the amount of penetration of the elastic blade of FIG. 3 into the toner carrying roller. FIG. 7 is a schematic diagram showing another embodiment of the developing device of the present invention. FIG. 8 is an explanatory diagram showing the state of the opposed portion between the developer carrying roller and the toner carrying roller in the developing device of FIG. 7. FIG. FIG. 9 is a schematic diagram showing still another embodiment of the developing device of the present invention. 1: Developer carrying roller 2.12: Magnet roller 3: Carrier 4: Toner 5: Doctor blade 6: Toner carrying roller 8: Elastic blade 9: Two-component developer 14.15: Power source 2nd factor Figure 3 Figure 7 figure

Claims (1)

[Scope of Claims] 1) A developer carrier carrying a two-component developer having toner and a carrier and transporting the developer, and the developer disposed opposite to the developer carrier. a toner carrier that receives, carries, and conveys the toner in the developer by contacting the developer carried on the carrier; and the toner in a portion of the toner carrier that faces the developer carrier. a toner regulating member that is in contact with a downstream position in the rotational direction of the carrier and that regulates the amount of toner carried on the toner carrier, and a magnetic pole that forms a magnetic field in the opposing portion that controls the toner in the opposing portion; A developing device comprising: a magnet disposed within the developer carrier and located downstream in the rotational direction of the developer carrier from a position of the contact portion of the regulating member. 2) The developing device according to claim 1, wherein the toner regulating member is made of an elastic blade, and the elastic blade is disposed facing in a direction opposite to a direction in which the toner is conveyed. 3) A direct current electric field or an alternating current electric field superimposed thereon is formed between the developer carrier and the toner carrier.
Or the developing device described in 2.