JPH0486866A - Developing device - Google Patents

Abstract

PURPOSE:To load/unload a toner supply roller and a magnetic brush roller together with a toner cartridge and to facilitate the replacement of developer and the maintenance by supporting the toner supply roller and the magnetic brush roller to the toner cartridge in a state they hold a specified gap. CONSTITUTION:The gap DG between the toner supply roller 75 and the magnetic brush roller 41 is an important point that is concerned with scraping toner from the roller 75 and collecting the excess toner from the roller 41 to the roller 75, and an allowable error is extremely small. Then, by loading/unloading the rollers 75 and 41 together with the cartridge in the state where they maintain the specified gap DG in the case of loading/unloading the cartridge 50, the replenishment of the toner with proper concentration is prevented from being hindered, which occurs because the gap DG is fluctuated by loading/ unloading the cartridge 50.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a developing device used in electrophotographic copying machines, printers, etc., and more specifically, a developing device using a two-component developer containing toner and carrier. Regarding.

[Conventional technology]

Various types of developing devices of this type have been proposed, one of which is disclosed in Japanese Patent Laid-Open No. 2-135476.

This developing device includes a toner cartridge that is removably attachable to the developing device main body, a toner supply roller that receives toner from within the cartridge and rotates while holding the toner on its surface, and a toner supply roller that faces the toner supply roller with a predetermined gap therebetween. death,
The apparatus includes a magnetic brush roller that rotates while forming spikes of developer on its surface, and is configured such that a predetermined bias voltage is applied to each of the toner supply roller and the magnetic brush roller.

In this developing device disclosed in the above-mentioned publication, of the toner supply roller and the magnetic brush roller, only the toner supply roller is supported by the toner cartridge, and when the cartridge is detached from the developing device main body, this toner supply roller is The cartridge is also attached and detached to prevent toner from spilling from the cartridge.

The reason for making the toner cartridge removable in this way is for the purpose of replacing the developer in the device due to deterioration and maintenance of the device.

To replace the developer, it is possible to open a lid on the main body of the device, but this involves turning the developing device upside down and shaking it, and if the toner cartridge is still attached, it may be bulky. It is expensive and heavy, making it difficult to work with.
This is because problems such as toner spillage and toner clogging near the cartridge outlet occur.

[Problem to be solved by the invention]

However, as described above, among the toner supply roller and the magnetic brush roller, only the toner supply roller is attached and detached together with the cartridge, and on the other hand, the gap between the toner supply roller and the magnetic brush roller is used to prevent toner from being scraped from the toner supply roller. This is an important point related to the collection of excess toner from the magnetic brush roller to the toner supply roller, and has extremely small tolerances.

Therefore, if toner or developer is accidentally spilled on the mounting portion of the cartridge and the developing device main body when the cartridge is attached or removed, the gap size is likely to change, and it is extremely inconvenient for this gap to change each time the cartridge is attached or detached. be.

SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device of the type described above, which can maintain a constant gap between the toner supply roller and the magnetic brush roller even when the toner cartridge is attached or detached.

[Means to solve the problem]

In accordance with the above object, the present invention includes a toner cartridge that is detachable from a developing device main body, a toner supply roller that receives toner from within the toner cartridge and rotates while holding the toner on its surface, and a toner supply roller that is provided with a predetermined gap. A two-component developer comprising magnetic brush rollers facing each other at a distance and rotating while forming ears of developer on the surface thereof, and configured such that a predetermined bias voltage is applied to each of the toner supply roller and the magnetic brush roller. A developing device using a developer, wherein the toner supply roller and the magnetic brush roller are supported by the toner cartridge while maintaining the predetermined gap, and are removably attached to the developing device main body together with the cartridge. provide.

[For production]

According to the developing device of the present invention, when replacing the developer or performing maintenance, the toner cartridge can be attached and detached from the developing device main body, and at that time, the toner supply roller and the magnetic brush roller are attached and detached together with the cartridge while maintaining a predetermined gap. be done.

〔Example〕

Next, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a cross section of an example developing device 1. As shown in FIG.

In an image forming apparatus such as a copying machine or a printer, this developing device 1 supplies toner to an electrostatic latent image formed on a photoreceptor layer 101 provided on the outer peripheral surface of a photoreceptor drum 100 rotating in the direction of arrow a. The developing device 2 is configured to visualize this as a toner image, and is composed of a developing device 2 and a toner cartridge 50.

The developing tank 3 of the developing device 2 has a side plate 4.4 (one of which is not shown).
, a bottom casing 5 and an upper casing 6.7.8, each having an opening 9.10 at the front (right side in the figure) and at the rear (left side in the figure).

In the developing section 11 facing the front opening 9 of the developing tank 3, magnet bodies 12.13 are fixed in a non-rotating state on the upper and lower sides, and a plurality of magnetic poles are arranged on the outer periphery of these magnet bodies 12.13. At the same time, in the upper magnet body 12, all magnetic poles S, ~S4
, N1-N,) are arranged alternately between S and N, with the spacing between the magnetic poles being small, especially in the rear region.

In the lower magnet body 13, there are two S poles (s7) only in the rear region.
, Se ) are adjacent to each other, and in other areas, the magnetic poles are S
, N are arranged alternately.

The cylindrical developing sleeves 14.15 are loosely fitted on the outside of the magnet body 12.13, and are rotated at the same speed in the directions of arrows A and C, respectively.
4, the tip of a height regulating plate 18 supported by the upper casing 7 is opposed to the upper outer circumferential portion of 4 with a predetermined height regulating gap Db+. Also, developing sleeve 14.15
are development bias ■, 1,
Vb2 is applied.

The holder 20 is made of a non-magnetic material and is attached to the upper developing sleeve 1.
4 and parallel to this developing sleeve 14, and the lower end portion 24 is connected to the lower developing sleeve 15 with a gap Db.
A portion facing the upper developing sleeve 14 with a □ has a curved portion 21 and an inclined portion 22 behind the curved portion 21 .

Further, a magnet plate 25 is attached to the curved surface portion 21 of the holder 20, and as shown in FIG. A plurality of them are provided in the rotational direction of the developing sleeve 14, and a dense magnetic field is formed between them and the magnet body 12.

Furthermore, the distance between the magnet plate 25 and the developing sleeve 14 is constant or narrows toward the downstream side in the rotational direction of the developing sleeve 14.

A packet roller 27 is arranged in a main developer stirring chamber 26 formed at the rear of the developing section 11 so as to be rotatable in the direction of arrow d.

This packet roller 27 has support plates 28a and 28a (
A plurality of packets 29 are installed at appropriate intervals between the outer peripheries of a (one not shown). Further, this packet 29 has a plurality of axial stirring blades 35 arranged on the inner surface every other one.

The packet 29 is made up of a front plate 30, a rear plate 32, which are located in front and behind with respect to the rotational direction of the packet roller 27, and a plate main body 31 located between them. It is formed.

At the rear of the developer stirring chamber 26, an auxiliary developer stirring chamber 36 is formed by widening the bottom casing 5 rearward. An auxiliary developer stirring blade 37 formed by attaching a blade 39 to a shaft 38 is arranged so as to be rotatably driven in the direction of arrow e.

The housing 51 of the toner cartridge 50 includes a main body 52
, the roller cover 53, the lid 54, and the side plates 55, 55 (
(one is not shown). Further, inside the housing 51, a toner storage section 56 and a toner supply section 57 are provided.
, a passage 58 connecting these, and a roller housing chamber 59 are formed.

A stirring blade 60 formed by attaching a blade 62 to a shaft 61 rotatably supported by a side plate 55.55 is disposed in the toner storage portion 56 so as to be rotatable in the direction of arrow ε, and a tip portion 63 of the stirring blade 60 is disposed so as to be rotatable in the direction of arrow ε. is formed into a shape protruding at an acute angle toward the direction of rotation (direction of arrow g), and a Mylar sheet 64 is attached outwardly to this tip 63.

A toner empty detection plate 65 is provided above the stirring blade 160. This toner empty detection plate 65 consists of two shafts 6 rotatably supported by side plates 55 and 55, respectively.
6.66 (one not shown) is equipped with a push-up plate 6, a support plate 67, 67 is attached to the push-up plate, and these tips are connected via a tip connection material 69. .

As the stirring blade 60 rotates, its tip 63 engages with the push-up plate 68 and is lifted to a predetermined position (position W shown by the solid line), and the stirring blade tip 63 and push-up plate 68 are held together. When it comes off, it falls onto the surface layer of the toner stored in the toner storage chamber 56.

A gate plate 70 is suspended from the upper part of the passage 58 to the lower right side thereof, and the lower end of the gate plate 70 is a free end and extends into the toner supply section 57 . When no external force is applied, the passage 5 is closed as shown by the broken line in FIG.
8 closes the lower right side of the passage 58, and when a rightward external force is applied to the lower end, the passage 58 opens as shown by the solid line in the figure.

In the toner replenishing section 57, a replenishing blade 71 formed by attaching a blade 73 to a shaft 72 rotatably supported by a side plate 55.55 is arranged so as to be rotatable in the direction of arrow i. The tip of the blade 73 is connected to the gate plate 70
is adapted to periodically engage the tip of the passageway 58 to open the passageway 58.

In the roller storage chamber 59, a toner supply roller 75 is rotatably supported by a side plate 55.55 via a support shaft (not shown).
is arranged so as to be rotatably driven in the direction of arrow j. A plurality of flange-like protrusions are formed along the entire circumference of the toner supply roller 75 at appropriate intervals in the axial direction, and the height thereof is 10 to 100 μm. The surface of the convex portion may be hard plated or coated with Teflon to improve wear resistance.

The roller storage chamber 59 further includes a toner supply roller 75.
A small gap DG is provided below the magnetic brush roller 4.
1 is arranged, and a magnet body 40 is fixedly arranged inside the roller 20.

The roller 41 can be rotated in the direction f in the figure. roller 41
faces the opening 10 of the developer tank 3, and faces the packet roller 27 and the auxiliary stirring blade 37 there.

Further, a regulating plate 4 is attached to the housing body 52 so as to face the rear outer peripheral surface of the magnetic brush roller 41 with a predetermined interval.
2 is installation. The regulating plate 42 may be formed of a magnetic material, and in this case, a magnetic chain of developer is formed between the magnetic brush roller 41 and the regulating plate 42, and toner spillage from this gap is prevented. .

Note that the magnet body 40 has a plurality of magnetic poles (S
+ I-S I:+, N11, N Iz ) are arranged, and the same S poles (S+t, S+, . . . ) are placed next to each other in the portion facing the packet roller 27. Also,
Magnetic brush roller 41 is connected to ground terminal 43.

The toner supply roller 75 is connected to an AC power source 80 and a DC power source 81.
are connected in series, and bias (3) is applied. The output waveform of the AC power supply 80 is not limited to a sine wave, but may be a pulse wave, a triangular wave, a sawtooth wave, or a complicated distorted wave as long as the current and voltage change periodically.

Further, on the outer peripheral surface of the toner supply roller 75, a spill prevention plate 76 attached to the end of the main body 52 constituting the toner supply section 57 and a regulation plate 7 supported by the roller cover 53 are provided.
The tips of 7 are in contact with each other.

The regulation plate 77 facing the toner supply roller 75 is held by the magnetic attraction force of a magnet plate 78 attached to the roller cover 53 and a magnet plate 79 attached to the regulation plate 77. Toner supply roller 7
A plurality of magnetic poles lined up in the axial direction of the magnet plates 78 and 79 are each arranged in a direction toward the toner supply roller 75.
The pressure force of the regulating plate 77 against the toner supply roller 75 is appropriately adjusted by the repulsive force and attractive force formed between the magnetic poles.

In this device, the timing at which the magnetic brush roller 41 is stopped from the driving state is delayed from the timing at which the auxiliary developer stirring blade 37 is stopped, so that when the toner cartridge 50 is attached and detached, which will be described later, the surface of the magnetic brush roller is Make sure that no developer remains on the surface.

The toner cartridge 50 having the above-described configuration includes the developing unit 2
FIG. 1 shows the attached state, and FIG. 4 shows the detached state.

Next, the operation of the developing device 1 will be explained.

A developer consisting of toner and carrier in a predetermined ratio is stored in the developing device 2, and this developer is mixed and agitated by a rotating packet roller 27 to bring the toner and carrier into frictional contact with each other. Charge to opposite polarity. Further, the axial stirring blade 35 of the packet roller 27 also causes the developer to be stirred in the axial direction.

As the packet roller 27 rotates, the developer flows into the recess 3 formed by the plate main body 31 and rear plate 32 of the packet 29.
4 and is supplied to the outer circumference of the lower developing sleeve 15 in the supply area R. The developer scooped into the bagerato 29 reaches the recess 34 through the opening 33 of the plate main body 31 from the area surrounded by each packet 29, and the developer located near the inner surface of the bottom casing 5 reaches the recess 34. I will not be scooped up by 34.

The developer supplied to the supply head R is held on the outer circumference of the developing sleeve 15 by the magnetic force of the magnet body 13, and is conveyed in the direction of arrow C as the developing sleeve 15 rotates, and is transferred to the holder 2.
The amount of conveyance is regulated at the lower end 24 of 0.

The developer that has passed through the lower end of the holder 20 is conveyed to a portion Q facing the upper developing sleeve 14 . In the facing part Q, N4 and S6 poles, S4 and N5 poles face each other in the vertical direction, and S4 and S6 poles of the same polarity, N4 and N, poles of the same polarity face in the diagonal direction, and there is a repulsive magnetic field. is formed.

Therefore, as shown in FIG. 3, the developer conveyed on the developing sleeve 15 in the direction of arrow C is prevented from entering the opposing portion Q, and is held at the magnetic pole S6 by the opposing portion of the magnetic poles S6 and N4. The developer is smoothly transferred to the magnetic pole N4.

Note that the magnetic force of magnetic pole N in the receiving area is applied to magnetic pole S6 in the delivery area.
By making it stronger (approximately 200 Gauss or more), the developer can be received and transferred more smoothly.

The developer supplied to the developing sleeve 14 is held by the magnetic force of the magnet body 13, and is conveyed in the direction of the arrow as the developing sleeve 14 rotates, passing through a portion facing the magnet plate 25.

Here, as shown in FIG. 2, a dense magnetic field is formed between the magnetic body 12 and the magnetic poles of the magnetic plate 25, so that the developer in the magnetic brush state is transferred between the developing sleeve 14 and the magnetic plate 25.
It is transported while undergoing shear failure between the two. therefore,
Frictional contact between the toner and the carrier increases, and sufficient charging power is applied to both.

The developer that has passed through the part facing the magnet plate 25 is transferred to the height regulating plate 1.
8, and this brush height regulating plate 18 and the developing sleeve 14
Only the developer that has passed through the brush height regulating gap Db+ is conveyed to the downstream side of the spike height regulating plate 18.

The developer regulated by the height regulating plate 18 falls into the main developer stirring chamber 26 along the inclined surface 22 on the back surface of the holder. Here, the lines of magnetic force formed by the magnet body 12 are focused on the magnet plate 25, and there is no magnetic field on the back surface of the magnet plate 25, and the magnetic force of the magnet body 12 does not reach the back surface of the holder 20. The developer regulated by 8 quickly falls into the main developer stirring chamber 26 without staying in front of it, and the stress applied to the developer is alleviated.

The developer that has passed through the portion facing the height regulating plate 18 continues to be conveyed in the direction indicated by the arrow as the developing sleeve 14 rotates, and passes through the portion facing the developing sleeve 14 and the photoreceptor drum 100 (
(hereinafter referred to as "development area") P, the photosensitive drum 100
toner is electrostatically supplied to the electrostatic latent image based on the potential difference between the surface potential of the electrostatic latent image and the developing bias voltage (1). Ru.

The developer that has passed through the developing area P1 is conveyed to a portion Q facing the developing sleeve 15, and is delivered to the developing sleeve 15 here. Here, the developer is transferred from the lower developing sleeve 15 to the upper developing sleeve 14 by the repulsive magnetic field formed in the opposing portion Q. Intrusion into the magnetic pole Q is prevented, and the flow is smoothly carried out from the magnetic pole S4 to the magnetic pole N.

The developer supplied to the developing sleeve 15 is conveyed in the direction of arrow C as the developing sleeve 15 rotates, and is transported to the developing area P.
In step 2, toner is further supplied onto the electrostatic latent image developed in the development area P1.

Further, the electrostatic latent image for which toner was insufficiently supplied in the development area P is visualized with sufficient density.

The developer whose toner concentration has been reduced after passing through the development areas P+ and P2 is continuously conveyed in the direction of arrow C as the development sleeve 15 rotates, and the developer that has passed through the development areas P+ and P2 is continuously conveyed in the direction of arrow C, and is removed from the toner formed therein in the intermediate area between the magnetic poles S and S. The magnetic pole portion releases the magnetic binding force and separates from the surface of the developing sleeve 15.

The developer that has fallen from the surface of the developing sleeve 15 is taken into the rotation locus of the outermost peripheral portion of the packet 29 by the developer conveying action caused by the rotation of the packet roller 27, and is conveyed to the rear of the main developer stirring chamber 26. .

Here, the front plate 30 of the packet 29 is
The outermost periphery of the packet 29 The developer captured within the trajectory of packet 29
conveyed along the bottom casing 5 without entering the inside of the bottom casing 5.

Therefore, the developer having a reduced toner concentration does not mix with the developer mixed at an appropriate toner concentration inside the packet 29.

Further, the developer that has fallen from the developing sleeve 15 is also captured in the recess 34 formed by the plate main body 31 and the rear plate 32, but the developer captured in the recess 34 is
The developer flowing out from the inside of the packet 29 through the opening 33 to the outside of the packet 29 and having a reduced toner concentration is not directly used for development.

The developer conveyed along the bottom casing 5 by the front plate 30 of the packet 29 is conveyed to the auxiliary developer stirring chamber 36, where it is mixed by the rotation of the auxiliary developer stirring blade 37.

The developer mixed in the auxiliary developer stirring chamber 36 is held on the outer periphery of the magnetic brush roller 41 by the magnetic attraction force of the magnet 40 located above the developer, and is regulated by the rotation of the magnetic brush roller 41. The toner is conveyed in the direction of the arrow f while being regulated by the plate 42, and the insufficient amount of toner is replenished at a portion T facing the toner supply roller 75 (hereinafter referred to as "replenishment area"). Note that the toner replenishment operation in the replenishment area T will be explained in detail later.

The developer that has been newly replenished with toner in the replenishment area T is conveyed in the direction of the arrow f and reaches the area U between the magnetic poles SI□ and 313.
The main developer stirring chamber 26 is released from the magnetic force of the magnet body 40.
It is replenished by falling while being dispersed in the form of a spray. At this time, a portion of the newly supplied developer containing uncharged toner falls on the developer held in the recess 34 of the packet 29; When the packet 29 passes through the portion facing the holder 20, it is almost never scraped off by the holder 20 and supplied to the developing sleeve 15 as is.

Replenishment of toner from the toner cartridge 50 is performed as follows.

The toner in the toner replenishing section 57 is conveyed toward the toner supply roller 75 as the replenishment blade 71 rotates, and the toner located in the vicinity of the convex portion of the toner supply roller 75 is held in the outer circumferential concave portion between the convex portions of the toner supply roller 75. The toner is conveyed in this direction, and excess material is scraped off from the surface of the toner supply roller 75 at the tip of the regulating plate 77 .

The toner held on the surface of the toner supply roller 75 and passed through the opposing portion of the regulation plate 77 is conveyed to the supply area T along the direction of arrow j.

In the replenishment area T, the developer in the auxiliary developer stirring chamber 36 is conveyed in a magnetic brush state (in the form of spikes) over a magnetic brush roller 41, and the scraping action of this magnetic brush-like developer and the toner supply roller Toner is supplied from the toner supply roller 75 to the magnetic brush roller 41 due to the potential difference (=bias V) between the toner supply roller 75 and the magnetic brush roller 41 .

However, from the toner supply roller 75 to the magnetic brush roller 4
1 is supplied with toner only when the toner concentration in the auxiliary developer stirring chamber 36 is below a predetermined standard toner concentration, and the toner concentration of the developer conveyed from the auxiliary developer stirring chamber 36 is equal to or lower than the standard toner concentration. Conversely, when the density is higher than that, excess toner is collected by the toner supply roller 75. That is, in the replenishment area T, toner density control is performed to maintain the toner density within the developing device 2 appropriately.

Further, in the toner replenishing section 57 , the rotation of the replenishing blade 71 causes the blade 73 to periodically engage with the tip of the gate plate 70 to curve the gate plate 70 from the dotted line state to the solid line state, so that the blade 73 is partitioned by the gate plate 70 . Toner is replenished from the tree-like space 58a of the passage 58 into the toner replenishing section 57. However, when the toner supply section 57 is filled with toner, the gate plate 70 hardly vibrates, and toner supply stops.

On the other hand, the toner in the toner storage portion 56 is stirred by the rotation of the stirring blade 60, thereby preventing crosslinking and blocking of the toner. Further, the toner is conveyed in the direction of arrow g along with the rotation of the blade 62 and the Mylar sheet 64 at the tip.
is supplied to passage 58.

Here, since the tip portion 63 of the blade 62 has a shape that projects at an acute angle toward the rotation direction, even if the blade 62 is buried in the toner or the blade 62 is exposed from the surface of the toner, Even if rotation starts, the tip 63
It rotates while easily crushing the toner. Further, even if the toner is left unstirred for a long period of time and becomes compacted, it is easily crushed.

In the empty detection plate 65, the push-up plate 68 periodically engages with the tip 63 of the stirring blade 60 as the stirring blade 60 rotates, and is lifted while rotating in the direction of the arrow to the solid line position, where the push-up plate 68 and the tip of the stirring blade are rotated. When the toner is disengaged from the portion 63, it rotates in the direction of arrow h'' and falls onto the surface layer of the accumulated toner.

At this time, the amount of rotation of the empty detection plate 65, that is, the amount of falling, varies depending on the amount of toner stored in the toner storage section 56. The amount of toner stored is large and the toner level is high, the amount of falling is small; As the amount decreases, the amount of falling toner increases, and when the remaining amount of toner in the toner storage section 56 decreases, the tip of the empty detection plate 65 moves toward the passage 5.
8 into the wedge-shaped space 58a.

Here, the toner in the toner storage section 56 is stirred up to the bottom by the Mylar sheet 64 provided at the tip of the stirring blade 60, and the toner is stably stored in the wedge-shaped space 58a. The toner level decreases when most of the toner in the toner storage section 56 is consumed.

Therefore, when the level of the tip of the toner empty detection plate 65 descending into the wedge-shaped space 58a falls below a certain level, this state should be detected by a detection means (not shown) and the toner cartridge 50 should be replenished with toner. inform about something.

The operation of the developing device 1 has been described above, but when replacing the developer (particularly the carrier) in the developing device 2 due to deterioration or when performing maintenance on the cartridge W1, as shown in FIG. It can be removed from the developing device 2 and reattached after necessary work.

When the toner cartridge 50 is attached and detached, the toner supply roller 75 and the magnetic brush roller 41 are attached and detached together with the cartridge while maintaining a predetermined gap. Therefore, due to the cartridge attachment and detachment, the gap is distorted and toner of appropriate density is not supplied. There is no problem with this.

Further, since the magnetic brush roller 41 is located below the toner supply roller 75, the possibility that the toner supply roller 75 will be damaged when the cartridge 50 is attached or detached is reduced accordingly.

〔Effect of the invention〕

As described above, according to the present invention, there is provided a toner cartridge that is removably attachable to the main body of a developing device, a toner supply roller that receives toner from within the toner cartridge and rotates while holding toner on its surface, and a predetermined portion of the toner supply roller that rotates while holding the toner on its surface. The toner supply roller includes magnetic brush rollers facing each other with a gap therebetween and rotates while forming spikes of developer on their surfaces, and is configured such that a predetermined bias voltage is applied to each of the toner supply roller and the magnetic brush roller. In a developing device using a two-component developer, a gap between a toner supply roller and a magnetic brush roller can be maintained constant even when a toner cartridge is attached to and detached from a main body of the developing device, and toner can be supplied stably.

Furthermore, since a portion of the toner supply roller is covered by the magnetic brush roller, there is less risk of the toner supply roller being damaged when the cartridge is attached or removed.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the present invention, Fig. 2 is a magnetic field line distribution diagram around the developing sleeve, Fig. 3 is a partial sectional view of the developing device shown in Fig. 1, and Fig. 4 is a toner cartridge. It is an explanatory view of a removed state. 1...Developing device 2...Developing device 50...Toner cartridge 40...Magnet body 41...Magnetic brush roller 42...Regulating plate 75...Toner supply roller 77...Regulating plate ■、...bias

Claims (1)

[Claims] (1) A toner cartridge that is removable from the developing device body;
a toner supply roller that receives toner from within the toner cartridge and rotates while holding the toner on its surface; a toner supply roller that faces the toner supply roller with a predetermined gap and rotates while forming spikes of developer on the surface; In a developing device using a two-component developer, the toner supply roller and the magnetic brush roller are provided with a magnetic brush roller and configured to apply a predetermined bias voltage to each of the toner supply roller and the magnetic brush roller. A developing device characterized in that the toner cartridge is supported by the toner cartridge while maintaining a gap therebetween, and is removably attached to the developing device main body together with the cartridge.