JPS58217965A - Developing device - Google Patents

Abstract

PURPOSE:To prevent toner scatter and fogging and to perform sharp development by providing removing means for toner sticking to a toner cloud control means which forms or carries a toner cloud by establishing an alternating electric field. CONSTITUTION:A toner cloud control electrode 8 is provided as a means of preventing the diffusion of toner T by controlling the transfer of the toner T supplied in a cloud state to the surface of an image carrier 3, and magnetic poles S and N are provided at a position indicated by a gap D between magnets 4b, 5b and an image carrier 3; and magnets 10 and 11 are further provided at the upper and lower edge parts of the opening part of a developing device case 9. The toner sticks to the cloud control electrode 8 and magnets 10 and 11 to degenerate the functions, so the removing means 8a, 10a, and 11a made of sponge, etc., for removing the sticking toner are provided and a removing means 14a for the sticking toner is also provided to an auxiliary control electrode 14 impressed with a DC voltage for accelerating the movement of the toner to the image carrier 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an electrostatic charge image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, etc. or a latent image of a magnetic image formed in a magnetic printing method, etc. by toner particles. (Hereinafter, single K
Regarding the improvement of a developing device that develops a latent image by generating a) nur cloud and supplying it to the surface of an image carrier. Dry development methods for developing charge images include two-component developers consisting of carrier and toner;
A method using a one-component developer consisting only of toner is known, and a developing method using a -component developer essentially does not cause a change in toner concentration, simplifying the configuration of the developing device. Although it is superior to systems using two-component developers in that it is possible to stably obtain developer characteristics over a long period of time without deteriorating, There is a serious drawback that -
Charge the component developer to the required state, and apply the developer to the image-bearing surface in the required state during development.
The main reason for this is that it is difficult to make decisions.

That is, in order to obtain a good visible image using the dry development method, it is necessary to charge the toner so that it forms a band with a polarity opposite to that of the electrostatic charge image to be developed and an appropriate size. In systems using two-component developers, the toner is triboelectrified by mechanically stirring the toner and carrier. Therefore, by selecting the characteristics of the gear, stirring conditions, etc., toner charging can be controlled. It is possible to control the polarity and the amount of charge to a considerable degree.

However, since such a carrier does not exist in a one-component developer consisting only of toner, it is extremely difficult to control the charge polarity and amount of charge of the toner.0 One of the developing methods using such a one-component developer As one example, the so-called powder cloud method has been known for some time (US 44r#T 1, No. 78.30).

This method involves blowing out developer powder from a nozzle-shaped metal tube, which charges the developer particles through contact friction, and at the same time forms a smoke-like developer cloud, causing the particles to act on the electrostatic M image. It is used for developing. In this method, individual developer particles can move along the lines of electric force caused by the electrostatic charge image, resulting in a visible image with high resolution. There is a possibility of being defeated. However, as mentioned above, this method also cannot appropriately control the charging state of the developer, and furthermore, it is not easy to color the developer cloud in a stable state. The powder cloud method has hardly been put into practical use so far because the formation of the powder cloud causes scattering of the developer, which causes a serious problem. In addition, in consideration of controlling the charging state of the developer, a powder cloud method using a two-component developer (!Vf Kaisho!; Publication No. 3-7301.7) is used.
has also been proposed, but this method uses mechanical means to scatter the toner to form a cloud, and this method prevents contamination inside the machine due to toner scattering and problems during development.
Not only is the problem of ``□ blur'' hardly improved, but also disadvantages due to the use of a two-component developer are added.

In view of the above circumstances, the present inventors have previously discovered that it is possible to form a developer cloud in a stable and controlled state using an alternating electric field, thereby making it possible to develop a latent image with high resolution. We have invented a developing method and a developing device.

Those inventions were filed in Japanese Patent Application No. 36-623.21. No. and % Gansho, lt4-43947.

The present invention relates to an improvement of the above-mentioned invention, and further provides a toner developing device that can perform clear development while preventing toner scattering and fogging. In a developing device that generates or conveys a toner cloud in JA, a toner cloud control means that generates or conveys the toner cloud by forming an alternating electric field is provided with means for removing toner adhering to the toner cloud. This feature achieves the above objectives.

Hereinafter, the present invention will be explained in detail based on the drawings.

p4/Printing, Fig. 2 is a schematic configuration diagram showing an example of a toner cloud forming mechanism, and Fig. 3 is a schematic diagram of a configuration showing an example of a toner cloud forming mechanism, and Fig. 3 is a schematic diagram of a toner cloud forming mechanism. Current #1! FIGS. q to q are cross-sectional views showing an example of a developing device including a conveying means having the toner cloud forming mechanism of FIG. 2 and a tree-removing means of the present invention. Figures 7 to 12 are the developing device shown in Figure 3! FIGS. 13 to 1S are schematic configuration diagrams showing in detail an example of the adhered toner removing means used for the toner control means in q.
FIG. 3 is a schematic configuration diagram showing an example of an attached toner removing means used for the toner control means in the developing device shown in the figure.

In the toner cloud forming mechanism shown in FIG.
The police box m-o Vac is applied to the filiiP/.

When introduced between P, 2, toner T has m poles P/, P
Electrode P/
, P, begins to oscillate between 2. Therefore, by using this, a toner cloud can be stably formed. Here, tunpoku: P/, P
, 2 expands to one side as shown in the diagram,
Centrifugal force is added to the vibration movement of the toner T, and the toner T
Shake as shown by the thin arrow line! 1il + exercise @
It begins to move toward the expanding direction of P/, P, and 2.

This movement is used to cause the toner cloud to act on the surface of the image carrier, but on the other hand, the toner T is diffused on the surface of the image carrier, causing contamination and fogging during development. As a practical matter, a toner cloud is generated by an alternating electric field.

If this is maintained, the gap between the electrodes P/ and P, 20 will almost always be widened at the end side as shown in the figure. Moreover, even if the above-mentioned configuration can be avoided, the toner T can be used as an electric w3PI.

22 causes the toner T to move in the same manner as described above, which also causes contamination and fogging.

In the toner cloud forming mechanism shown in the cross-sectional view in FIG. 2 (4) and the surface perspective view in FIG.
- An insulating layer λ with many holes is provided thereon, and an electrode Pa is further provided on the upper surface.
The toner T is guided inside the pores of the insulating layer λ, where it is
A toner cloud is formed under the influence of the lines of electric force of the alternating electric field as shown by the chain arrows generated between the L poles PJ and PI3. Note that the electrode P3 may be provided inside the surface of the base 1, or provided only at the bottom of the hole in the insulating layer 2, or on the base of the insulating layer 1. The electrode Pu may be provided only at the connection part with /, and the electrode Pu may also be embedded in the upper part of the insulating layer 2, or it may be provided on the upper side of the hole in the insulating layer 2. It may be something. Even in such a toner cloud formation mechanism, the formed toner cloud moves to the outside where the alternating electric field is open, and centrifugal force and inertial force accompanying the movement of the base body are added to it, and the inside of the machine is affected. This may cause stains or fog during development.

As described above, the conveying means that generates a toner cloud and supplies toner to the surface of the image carrier is prone to staining and fogging. Therefore, in addition to providing a means for controlling the transfer of toner supplied from the conveying means to the surface of the image carrier, it is necessary to also provide a means for removing the adhered toner, since toner will adhere to the control means and a stable effect cannot be obtained with this alone. The developing device of the present invention is designed to prevent the occurrence of contamination due to toner scattering and the occurrence of fog during development.

In the developing device shown in FIG. 3, aluminum or brass, which has a photoreceptor layer on the surface 1cse, etc., is provided facing the surface of the image carrier 3, which rotates in the direction of the arrow, and rotates in the direction of the arrow, respectively. Sleeve 4ta made of non-magnetic material such as
a pair of magnetic drums U and S, each consisting of a magnet body Ilb and tb fixedly provided inside each of the magnetic drums U and S.
A conveying means is constituted by the sleeve lIa, and a DC voltage and an AC voltage are applied to the sleeve lIa, and a DC voltage m is applied to the sleeve and ta, and the sleeve 4! a, Ja is the electrode P/, P, shown in FIG.
The toner T in the toner reservoir B is attached to the surface of the sleeve IIa by the magnetic force of the magnet body ψb, and passes through the doctor blade 7 made of a magnetic blade or the like, thereby forming the sleeve ψa! is introduced into an alternating electric field between ra. The introduced toner T forms a toner cloud, as described with respect to FIG. The image carrier 3 is affected by the airflow accompanying the rotation of the sleeves pa and ta.
Go to the side. As a result, the toner T is supplied to the surface of the image carrier 3 in the form of a cloud.

Furthermore, due to the arrangement of the magnetic poles N and S in the magnet body Ilb, the toner T in the toner reservoir B is properly attached to the sleeve <Za,
The amount of adhering toner T is effectively regulated by the doctor blade 7, and the regulated toner T is transferred to the sleeve <ta.
It is considered that the toner remains attached to the sleeve as much as possible until it reaches the alternating electric field region closest to the toner and ja, and when it reaches the alternating electric field region, the restraint of the magnetic force is released and the action of the alternating electric field is sufficient to prevent the toner from falling. has been done.

The toner T supplied in the form of a cloud to the surface of the image carrier 30 is
As mentioned above, the sleeves fa and ta are used on the front surface of the image carrier 3 as a means to control the transfer of the toner T and prevent it from spreading, since it is inherently easy to fly off and cause stains and fog. In the space sandwiched between the toner cloud control electrode r and the image carrier 3 of the magnet bodies tIb and tb,
Magnetic poles S and N are located at the positions indicated by the gaps facing each other, and magnets 10 and 10 are located at the upper and lower edges of the open portion of the developing device case 9 that is open toward the image carrier 3, respectively.
/ is placed. As shown in the figure, a DC voltage is applied to the cloud control electrode l to control the deceleration of the toner cloud toward the surface of the image carrier 3, or a voltage in which an AC voltage is superimposed is applied thereto. The toner cloud is held in the space surrounded by the sleeves 4ja, ja and the cloud control electrode t so that development without fogging is performed, or furthermore, the aggregation of the toner T in the toner cloud is prevented to maintain the cloud state. ensure that it remains stable. Magnetic poles S and N provided in the positions shown by the gaps facing the image carrier 3 of the magnets vb and sb move the toner cloud that tries to escape outside the developing area without contributing to development into the sleeve 4 ( a
.

to prevent stains and fog from occurring. The magnet lθ, // is the magnetic pole S, N of the magnet body gb, tb
The toner cloud that has escaped capture by K is captured to prevent stains mainly due to toner diffusion to the outside of the developing device.

Since toner adheres to the cloud control electrode t and the magnet lθ, which deteriorates their functionality, use a sponge or similar device that reciprocates from one end to the other at appropriate intervals to remove the adhering toner. A removing means ta, 10a+l/a is provided. These removal means will be described later.

The toner captured in the sleeves 9a and 3a of the magnetic drum <c, t is collected by the cleaning blade 12 into a toner reservoir B for the sleeve tIa, and is attached to the sleeve ta by the magnetic force of the magnetic pole S of the magnet 3b. The toner is then carried away and scraped off by the cleaning blade 13 into the toner pool A.

In the developing device shown in FIG. 3, there is a button to prevent the toner cloud formed in the alternating electric field space from escaping in the direction opposite to the image carrier 3, and a button to encourage the toner cloud to advance toward the image carrier 3. An auxiliary control electrode to which a DC voltage is applied is also provided. Although this is effective in increasing the density of the toner cloud acting on the surface of the image carrier 3, it is not necessary to provide it. This is also provided with adhesion toner removing means/4(a).

According to the developing device shown in FIG. 3 as described above, the toner cloud formed by the conveying means acts on the image carrier surface in a sufficiently stable and controlled state, and the toner cloud that does not participate in development is diffused. It is almost completely prevented, and it is possible to perform stable and good development with high resolution for a long time, and it is possible to obtain excellent results without causing problems such as stains and fogging. . In the device shown in FIG. 3, the sleeves lIa, , ta are fixed and the magnet body <
<b.

! K to rotate b, or sleeve &a
, ja and the magnets Ilb, tb, respectively, are rotated integrally, the conveying means can achieve the same conveying purpose as described above.

In the developing device shown in FIG. A superimposed voltage of AC voltage and DC voltage is applied to the electrode P3 on the base/side shown in FIG. 1, and an if current voltage is applied to the electrode PII provided above the insulating layer λ.
Each voltage is applied by the power source shown in FIG.

In this developing device, the toner T is introduced into the hole of the insulating layer λ shown in Fig. 1 by the surface of the cloud conveyance drum/jj diving into the toner T in the toner reservoir B, and when the toner T has finished diving, it is transferred to the hole by the ζ filter. The introduced toner T is clouded as described in FIG. 1, and the clouded toner T
is conveyed with the rotation of the cloud conveyance drum lj, and develops the latent image on the surface of the image carrier 3 in the developing area closest to the image carrier 3. During this time, the excess toner T adhering to the upper part of the insulating layer is removed by the doctor blade 7 and dropped into the toner reservoir.

In this developing device, the insulating layer 2 and the electrode PII to which DC voltage is applied serve as a means to prevent toner from spreading, and if toner adheres to these, a stable toner cloud will be formed. As a result, toner scattering and fogging are more likely to occur. In order to remove the attached toner, a brush roller /6 rotating in the direction of the arrow is provided as a removing means.

With this developing device as well, as with the developing device ffK shown in FIG. 3, it is possible to stably perform high-resolution and good development for a long time, and the occurrence of stains and fogging can be prevented.

The developing device shown in FIG. S uses the same conveying means as the developing device shown in FIG. A voltage is applied, and a superimposed voltage IF of an AC voltage and a DC voltage is applied to the electrode PII provided on the upper part of the insulating layer λ. In this case as well, similar to the developing device shown in FIG.
When dispersing toner, the 11th means is cloud conveyance drum/JK
The attached toner is removed by the brush roller/B rotating in the direction of the arrow.

With this developing device, the same results as in the developing devices shown in FIGS. 3 and 4 can be obtained.

The developing device shown in FIG. 6 is composed of a sleeve drum/7a having a similar surface layer structure and a magnet body fixedly provided inside the cloud conveying drum/jj in FIG.
Remove the cleaning drum/l, which consists of a cloud conveying magnetic drum/7 consisting of b, and has a magnet body/gb fixedly installed inside the sleeve/a which rotates in the direction of the arrow instead of the brush roll 16. The point used as a means is J.
It is different from the developing device No. 11. This developing device uses magnetic toner as the developing device shown in FIG. Effectively regulated by 1. Furthermore, the toner cloud acting on the surface of the image carrier 3 is controlled and scattered.
4. Magnetic poles N and S are arranged so that there is no difference between them.

That is, in this development IR, the magnetic pole N of the magnet 7b facing the surface of the image carrier 3 is also used during toner diffusion! [Works as a secondary means.] Due to the magnetic force of the cleaning drum/1st magnet body/Ib provided inside, the toner captured on the cloud transport magnetic drum 17 that has passed through the development area is not only transferred to the surface of the sleeve/7a, but also transferred to the image carrier. The toner floating in the space between the magnetic drum 3 and the cloud transport magnetic drum 7g is also captured. Sleeve/7a
The toner captured on the surface of the cleaning blade/9
The toner pool is scraped off by the toner. In the developing device shown in FIG. 3 as well, magnets lθ, // for preventing toner escape as shown in FIG. 3 can be provided on the upper and lower edges of the developing device case 9. In addition, the developing device R in Figures V and S
kJ, which is used when the toner is a non-magnetic toner, so in that case, an electrode for capturing the toner may be provided in place of the magnet /θ, //.

In the developing device shown in FIG. 6, the same results as in the developing device shown in FIGS. 3 and 3 can be obtained. And this developing device ff
It is also possible to use non-magnetic toner in f.

In the above-mentioned developing device, a single pole P/, Pcom or P3, PtI as shown in Fig. 1, Fig. 2 is used.
As the AC voltage applied to ! ;OHz-! OkH
z.

A voltage in the range of ioV to 2 kV is suitably used, and a positive or negative DC voltage in the range of o-5oV to be applied singly or in a superimposed manner is suitably used. Furthermore, the image carrier 3 in the example of FIG.
The gap between the image bearing member 3 and the cloud conveying drum 15 or the cloud conveying magnetic drum 17 in the examples shown in FIGS.
It is preferable to set it within a range of about OO μm.

As an example, the conditions under which the above-mentioned remarkable results were obtained in the developing device shown in FIG. 3 are shown in the table below.

Peripheral speed of image carrier 3 /, 20 f/s Peripheral speed of magnetic drum and j tsom/s Applied AC pressure to sleeve tIa /kHz, /-200
V DC voltage iso V DC voltage applied to sleeve 3a /! Applied voltage to OV cloud control electrode l -100V auxiliary control electrode/j
Voltage applied to -300V The developing device of the present invention is applicable not only to electrostatic latent images but also to magnetic latent images. In that case, of course, a magnetic toner is used as the toner, and a developing device as shown in FIGS. 3 and 6 is used.

Next, a supplementary explanation will be given of the adhered toner removing means of the toner cloud control means in the developing device of the present invention.

The toner cloud control means includes linear electrodes or magnets such as the cloud control electrodes and auxiliary control electrodes shown in Figure 3.
, /l, the control means and toner removal means shown in FIGS. 7 to 12 can be used.

In FIG. 7, the linear π also has an endless pole, and the toner that rubs and adheres to the rotating tensioning body 2/, the linear electrode that is suspended by the sword and rotated thereby. A brush-like cleaning member n is fixedly provided so as to remove.

Note that FIG. 7 (support) is a normal WI view, and color) is a side view.

The figure shows a winding roller 24 on which the linear electrode I reciprocates.
1, an example is shown in which a cleaning member n made of a scraper, felt, brush, etc., rubs a linear electrode stretched by H and reciprocates from side to side to remove adhering toner. In FIG. 1, (4) shows a front view, and (B) shows a side view.

In Figure 9, a linear electrode is stretched between fixed tension members 26 and n, and a cleaning member B similar to that in Figure 9 reciprocates from side to side during non-development and adheres to the linear electrode. This example shows how to remove the toner.

1O to 12 show that the linear electrode is
- Figure 10 shows an example in which a cleaning brush consisting of a fixed brush is installed in a ladder-like manner in parallel between the brushes and moved in the horizontal direction (in the direction of the arrow). Element,
2JiC Therefore, FIG. 11 shows the cleaning member 2 rotating in the direction of the arrow similar to the brush roller 16 in FIGS. q and 5. Also, Fig. 12 shows the cleaning drum/g shown in Fig.
The toner adhering to each linear electrode is removed by a cleaning member n similar to the above.

An example is shown. Note that the cleaning member n in FIG. 1 is equipped with a beating bar J for knocking off toner adhering to it, and such a beating bar 1 is also used on the brush roller /l in FIGS. V and 3. can be provided. Further, in the cleaning member n in FIG. 12, the sleeve holder 3a rotates in the direction of the arrow.
Magnetic body, 2. ? The toner b rotates in the opposite direction of the arrow, and the toner that is captured and adhered to the sleeve 23a is carried in the direction of rotation of the sleeve JJa and removed by the cleaning blade y. Such a cleaning member n is used as the sixth
It may also be used for the cleaning drum/l shown in the figure.

11 to 13 show examples of removal means suitably used for cleaning the cloud conveyance drum t3 or the cloud conveyance magnetic drum 17 in FIGS. V to 6, in which FIG. With a cleaning member n similar to the brush roller/7 in FIGS. V and 3, in FIG. 7e with a cleaning member similar to that in FIG.
An example is shown in which adhered toner is removed by a cleaning member n similar to that in FIG. 12. In addition, the seventh
The cleaning member n in FIG. 3 is equipped with the beating bar 1 as in FIG. It is possible to prevent adhesion and fully utilize the features of toner cloud development.Therefore, there is no staining or fog caused by toner diffusion, and clear, high-resolution images can be recorded stably. It can be carried out.

[Brief explanation of drawings]

1 and 2 are schematic configuration diagrams showing an example of a toner cloud forming mechanism, respectively, and FIG. 3 shows an example of a developing device of the present invention equipped with a conveying means for accommodating the toner cloud forming mechanism of FIG. 1. 7 to 12 are cross-sectional views showing an example of the developing device of the present invention equipped with a conveyance means having the toner cloud forming mechanism shown in FIG. 2, respectively. A schematic configuration diagram showing an example of the adhered toner removing means used for the toner control means in the developing device shown in FIG. 3, and FIGS. FIG. 2 is a schematic diagram showing an example of an attached toner removing means used in the present invention. T...toner, P/~Pg...electrode, //...substrate,
C... Insulating layer, 3... Image carrier,
<c, t...magnetic drum, 4(a,,ta...
・Sleeve, *b, tb...Magnet, N, S
...Magnetic pole, 6...Toner pool, 7...
Doctor blade, t... Cloud control electrode, 9...
Developing device case, /θ, //... magnet, 9, /θa
, //a , /la ”'removal means, /2 , /3
・・Cleaning blade, /G・Auxiliary control electrode, /3
...Cloud conveyance drum, /6...Brush roller, 17...Cloud conveyance magnetic drum, /7a...Sleeve drum, /7b...Magnet, 7
g...cleaning drum, /ga...sleeve, /fb...magnet,
/9...cleaning blade, 〃...linear electrode, 2/, n...rotating tension body, n...cleaning member, 2Ja...sleeve, 23b...magnet, 2I/ -, B.
... Winding roller, %, 27 ... Fixed tension body, I
...Bashing bar, d...Cleaning blade. % Yorito Konishi Roku Photo Industry Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 4 Figure 10 Calculation 11 En0 Box 42 Figure 13

Claims (1)

[Scope of Claims] 1. In a developing device that generates or conveys a toner cloud in a developing area on the surface of an image carrier for development, the toner cloud is attached to a toner cloud control means that generates or conveys the toner cloud by forming an alternating electric field. A developing device comprising a toner removing means. 2. The developing device according to claim 1, wherein the control means is a movable electrode and the removal means is fixed. 3. The developing device according to claim 1, wherein the control means is a fixed electrode, and the removal means is movable. 4. The developing device according to claim 1, wherein the control means is a movable electrode, and the removal means is movable.