JPS5818657A - Developing device for electrostatic charge image - Google Patents

Abstract

PURPOSE:To regulate the amount of a developer with high precision, to charge toner to necessary polarity, and to perform stable and secure development, by providing a regulating roll for the amount of the developer in opposition to a developing roll, and applying a charging control voltage between both the rolls. CONSTITUTION:A recovery blade 8 and a regulating roll 7 provided facing a developing roll 3 constitute a regulating mechanism 6 for the amount of a developer, and a charging developer control voltage E1 is applied between the regulating roll 7 and developing roll 3 in such a way that supplied toner has the opposite polarity to an electrostatic image at an image part. When nonmagnetic toner is used as the developer and the toner reaches a regulation area C, some of excessive toner having the same polarity with the latent image is separated and removed to flow as shown by an arrow A, and the toner having the opposite polarity to the latent image remains in a thin layer and is carried to a development area 4. Therefore, the amount of the developer is regulated with high precision and toner with necessary polarity is supplied, performing excellent developement.

Description

[Detailed description of the invention] (2) The present invention relates to an electrostatic image developing device.

- In dry development methods for visualizing electrostatic images formed in electrophotography, electrostatic notation, electrostatic printing, etc., a developer made of colored powder is used. Ru.

As this developer, two-component developer consisting of carrier and toner, and one-component developer consisting of only toner are known, but in particular, the developing method using -component developer is Compared to the method using , it is possible to perform stable development because the toner lightness does not change.
It is also advantageous in that the device used in Fumizuki is simplified.

However, in the method using a 4IK-component developer, there is no carrier that controls the charging state of the toner, unlike in a two-component developer, so the charging of the toner cannot be sufficiently controlled. That is, in the area of the developer where certain toner particles are made to act on the electrostatic image, the toner particles adhere to non-image areas of the electrostatic image support where no charge exists. In order to prevent this, when applying a bias electric field such as a DC electric field or an alternating current electric field to the toner particles, toner particles of opposite polarity will appear in the non-image area. The phenomenon of adhesion will occur. In order to ensure the desired bias effect IIk accompanied by such a phenomenon, the wrinkled toner carrier 1lIv7i must be in a required state, that is, a state 1 having a polarity opposite to that of the electrostatic charge image and an appropriate amount of charge. [K-charged toner is required to be held in a thin layer.

Specifically, in the example shown in FIG. 1, as shown in FIG. ii) An image copper agent conveying body consisting of a rotating developing roll 3 is provided, and its outer peripheral surface faces the photoreceptor 1. A part of the developer roll consisting of toner filled inside is placed and conveyed in the direction of the arrow in the figure, and the wrinkled developing roll 3 and the photoreceptor are facing each other.
Although the toner is introduced into the I area 4, the toner introduced into the developing area 4 has a particle diameter of, for example, 10 to 500 microns on the surface of the 3J Iro 11 18657 (2) 3. It is necessary that the layer be a thin layer with a thickness of about 100%.

In order to meet such demands, conventionally, the development area 4
A developer amount regulating member consisting of, for example, a doctor blade 5 is fixedly provided near the outer circumferential surface LJI of the developing roll 3 on the upstream side of the developer roll 3, and this regulates the amount of developer conveyed from k toward the ll1gI area 4. are doing.

Therefore, the doctor blade 5 is required to be provided so that a developer passage gap of a certain size, usually within a range of 10 to 500 microns, is formed in relation to the outer peripheral surface of the ijlLgII roll 3. However, with the mechanical developer amount regulating means using the doctor blade 5, it is extremely difficult to regulate the size of this gap at a high Ift. In order to alleviate this condition when the developer is a magnetic toner, a method using a magnetic blade has also been proposed (see II of Japanese Patent Publication No. 4I 1982-93177).

However, in any case, the conventional developer amount regulation (5) member resists the developer conveying force of the developing roll 3, which is the developer conveying force, and prevents the excess amount of the developer from passing through. Since the main purpose is to regulate the amount of developer directed to the development area 4, rather than to prevent
In this case, the developer whose passage is blocked becomes accumulated on the upstream side of the developer amount regulating member, or it often aggregates (this causes the developer passage gap to become clogged, causing the developer layer to become clogged). There is a risk that some portions of the -sK developer are not transported, resulting in so-called white streaks, and as a result, it is not possible to achieve a stable thin layer of developer.

In addition, since the doctor blade and the magnetic blade only regulate the amount of single Kll toner passing through, it is possible to prevent the undesired polarity of the toner agent, which is the same as the polarity of the electrostatic latent in the image area of the photoreceptor 1. Polarly charged toner particles are also transported to the development area, and as a result, even if a thin layer could be formed, wrinkled toner particles tend to adhere to non-image areas. There is a drawback that good development cannot be achieved.

(6) The present invention eliminates the above drawbacks and makes it possible to form a developer layer with a suitable thickness by regulating the amount of developer transported to the 3jIgII region with high precision.

To provide an electrostatic image developing device capable of conveying only developer particles charged to a state suitable for development to a developing area, that is, capable of stably and reliably achieving good development of an electrostatic image. The purpose is to

Embodiments of the present invention will be described below with reference to the drawings.

In the present invention, as shown in FIG. A developer amount regulating mechanism (hereinafter simply referred to as "regulating mechanism") 6, which itself has a developer conveying function, is provided so as to face the outer circumferential surface of the developing roll 3 in the region. As a result, a branch conveyance path (indicated by an arrow mark in the figure) branched from the developer conveyance path by the developing roll 3' is formed, and a KN mechanism is formed between the regulating mechanism 6 (7) and the '1A11 roll 3. A charged developer control voltage application mechanism (hereinafter referred to as a single K "voltage application 411") is used to apply a developer control voltage (hereinafter referred to as a single K "control voltage").
It is called ``structure''. ) El is provided and configured.

To explain specifically, Figure 2 is! This is an example of a case where a non-magnetic toner is used as a magnetic agent, and the regulating mechanism 6 in this example is constituted by a regulating roll 7 made of a non-magnetic material with a relatively small diameter, which is controlled by means other than the force plate, e.g. Since the outer circumferential surface thereof has a rough surface or an uneven surface, it has a developer conveying function, and is rotated in a direction opposite to the direction of the developing roll 3 in a regulation area C facing the ms roll 3. Then, the developer supporting and conveying portion of the developing roll 3 is attached to the conductive sleeve or its outer periphery WJ by several μm to several tens of μm.
The conductive sleeve is made up of a sleeve provided with an insulating layer having a thickness of 100 μm to several tens of μm thick, and the luer is made of a conductive sleeve or a sleeve provided with an insulating layer several μm to several tens of μm thick on its outer peripheral surface, The voltage applying device *EI is connected between the conductive sleeves of both rolls, so that the regulation roll 7 in the regulation area CK has a polarity opposite to that of the electrostatic latent image on the photoreceptor 1. Make it 5. Of course, although not shown, a developing bias voltage is applied between the base of the sensory body 1 and the 3ji image roll 3. For example, when using a selenium photoreceptor, the developing bias voltage is -
A DC voltage of 100 to -500 V@variable is often used.

In the following description of each embodiment, unless otherwise specified, it is assumed that the above-mentioned or similar developing bias voltage is applied. Further, in this embodiment, the developing roll 3 has a developer conveying function by means similar to the above-mentioned regulating p-luer, but this is not limited to this. The regulation sail 7 is provided with a collection blade 8 for separating the 3iIIIll agent and collecting it in the developer tank 2, or the outer circumferential surface area of the developing roll 3 further upstream from the regulation port to the Lua. It is preferable to provide a developer amount preliminary regulation blade 9 which also serves as a charging member to which a voltage can be applied, if necessary. lO is the developing roll 30 provided downstream of the developing area 4 in the developing roll 3.
This is a cleaning blade that scrapes off toner particles (9) remaining on Table m.

According to such a configuration, when an excessive amount of developer is conveyed from the developer tank 2 by the developing roll 3 and reaches the regulation area CK where the regulation mechanism 6 is located, the excess aS agent is transferred to the developer of the regulation mechanism 6. The toner particles are diverted by the agent transport function, but since the control voltage is applied to the regulation roll 7 at this time, toner particles having the same polarity as the electrostatic latent image polarity of the 10th image area of the sensory body are preferentially distributed. It is separated and removed from the developing roll 3 which is diverted and directed toward the developing area 4 . That is, in the illustrated example, the excess developer, mainly containing toner particles charged to an unnecessary polarity, is separated by *m of the regulating roll 7 as shown by the arrow mark. As a result, the excess amount of developer is separated and removed on the developing roll 3 that has passed through the regulating mechanism 6, and an appropriate amount of developer is formed, and furthermore, a developing agent consisting mainly of toner particles charged to the opposite polarity to the polarity of the electrostatic latent image in the image area is deposited on the developing roll 3. The m-copper agent, which is suitable for
) Good development can be achieved.

The voltage application mechanism E1 may be any mechanism as long as it generates an electric field in the regulation area Ck formed by the developing roll 3 and the regulation roll 7 facing each other (specifically, for example, it may apply only a DC voltage). The configuration for applying the voltage and the power of applying the DC voltage by superimposing it on the AC voltage can be mentioned.

Among these, the configuration in which an alternating voltage is applied superimposed on the #1 voltage can be cited as the most preferable example;
According to this, the generated alternating electric field vibrates the developer in the regulation area CK, and even if there is aggregated toner, it is crushed by the IIA plow and the toner particles are shaken in the state of unit particles. , toner particles charged to an unnecessary polarity by the DC voltage are reliably selected and diverted, and the toner conveyed to the development area 4 does not contain aggregated toner. 1iiIO-Rule 3
The Ilm and magnitude of the control voltage to be applied will vary depending on the distance between the developer and the regulating roll 7, the physical properties of the toner particles, etc.
(11) ~50Gμm, and the particle size of the toner particles is several μm to 10 liters
1ljlsH1 kit, 100~500V@
Ii: IF) iE current voltage and 100 V ~ 1.5 kV
The above-mentioned effect can be obtained satisfactorily by applying a sine wave alternating current voltage of several hundred H2N of several kHz at li degrees in a superimposed manner.

Here, as shown in Figure 3, only a DC voltage vD is applied between the base 1m of the sensing body 1 kept at ground potential and the regulation roll 7, and the relationship between the base 1m and the developing roll 3 is k, DC voltage V'D I:I) Alternating voltage v to developing bias voltage
! A voltage application structure E may be provided which applies a voltage with a superimposed voltage of As the voltage is applied, the control roll 7 receives the llI meeting drum 3#! An alternating voltage Vλ having a phase inverted from that of the voltage c is applied superimposed on the DC voltage.

The polarity of the applied voltage in the examples described below, including the example of the third cabinet, is 1.1 when a negatively charged photoreceptor such as a selenium-based photoreceptor is used as the photoreceptor.
657 (4) Something.

Examples of the seven alternating voltages to be superimposed on the DC voltage VDk include a sine wave, a rectangular wave, a pulse with a duty ratio of 50- or less, a pulse with a duty ratio of 50Is or more, a sawtooth wave, and the like. These applied voltages are
It is necessary to set the voltage so that no discharge occurs between the two micrometers, and for example, it is usually preferable that the absolute value is 4 kV or less.

In this way, the layer thickness of the developer transported to the developing area 4 can be regulated to a desired size with high precision, and the excess developer that is prevented from passing through the regulated area C can be stored. (Therefore, there is no risk of agglomeration, and as a result,
The above-mentioned am agent amount regulating effect can be stably and reliably achieved over a long period of time, and furthermore, toner particles charged to the required polarity can be reliably carried into the K11l image area 4. That is, it becomes possible to smoothly supply a suitable thin layer of developer to the developing area 4KtK.

If the first collection blade 8 is provided in contact with the regulation roll 7 as in the illustrated example, the developer conveyed by the regulation roll 7 can be collected into the developer tank 2 by this (13). At the same time, since the developer is removed from the first regulation link 7, the above-mentioned separation and removal of the excess developer can be reliably achieved over a long period of time. The cleaning blade 10 is for returning the developer remaining on the developing roll 3 without being subjected to development into the developer tank 2.

The case where non-magnetic toner is used as the developer has been described above, but if the developer is magnetic toner, 3111
It is advantageous to use magnetic forces to transport the agent.

For example, regarding the developing roller 3, there is a structure of a sleeve/magnet integrated rotating wet roll in which a magnet is integrally fixed to the inner peripheral surface of a rotating cylindrical sleeve, and a structure in which a magnet is installed independently within the rotating cylindrical sleeve. A fixed sleeve-rotating roll configuration, a magnet-rotating roll configuration with a fixed cylindrical sleeve and independent magnet rotation, or a rotating cylindrical sleeve with an independent magnet rotating roll. (14) A girder magnet/sleeve rotating type roll configuration can be used, in which case it is possible to use a rotating roll. Regarding the structure 6, the regulation roll 7 has a configuration of a rough leakage roll with an outer peripheral surface of 5 tiir, or a configuration similar to the A-image roll 3, that is, a sleeve/magnet integrally rotating type roll, sleeve rotation 11Jule, magnet rotation! 1
--Can be of any type, such as rolls, magnet-sleeve rotating rolls. The developing roll 3 and the regulating roll 7 may have the above-mentioned configurations and may be used in combination. Furthermore, regardless of whether or not the cylindrical sleeve rotates,
The developer is transferred to the development area 4 by rotating a magnet called a so-called magnet roll inside the toothed scissors cylindrical sleeve.
In the case of conveyance, the regulating roll 7 may be made of a ferromagnetic material, and the regulating roll 7 may be disposed near the developing roll 3, thus forming the regulating device 6.

For example, FIG. 4 shows an example of a regulating mechanism consisting of a developing roll 3 having a sleeve-rotating roll configuration and a regulating roll 7 having a rough outer circumferential surface. A voltage application mechanism E is connected to the roller roller 3 (15) for applying a voltage in which, for example, an alternating current voltage vA is superimposed on a DC voltage VD as a control voltage. It has a structure in which a magnet is fixed and provided independently within the rotating cylindrical sleeve BL. According to such a configuration, an excessive amount of magnetic toner from the developer tank 2 is absorbed by the magnetic force of the magnet in the developing roll 3. When the am agent is transported and reaches the regulation area CK, the same effect as in the example shown in No. 21!11 is obtained, that is, for development, K is an excess developer containing toner particles charged to an unnecessary polarity. is diverted by the regulating roll 70 and the image material conveying device 111, but at this time, since a control voltage is applied between the regulating roll 7 and the lA image roll 3, the sleeve BLk of the developing roll 3 is separated. Unnecessary toner particles having a polarity opposite to that of the regulating roll 7 are preferentially shunted to a direction 5 as shown by an arrow mark, and are separated and removed from the V4 image roll 3 heading toward the development area 4. As a result, the developing roll 3 that has passed through the regulating mechanism 6
At the top, the excess amount of developer is separated and removed and becomes the appropriate amount.
1) Opening 58-18657 (5) In addition, toner particles charged to the opposite polarity to the polarity of the electrostatic latent image in the image area remain in the form of a thin layer, and this is carried into the development area 4, so that a good result is obtained. Development can be coupled.

To give yet another example, FIG. 5 shows a developing roll 3 having a magnet/sleeve rotating type roll configuration so that the magnetic pole of the developing roll 3 and the magnetic pole of the anti-resistance roll 7 having the opposite polarity are always opposed to each other. , an example in which the regulating roll 7 having the configuration of a rotating magnet type μ"-roll is combined, and the 6th al is a combination of the developing roll 3 having the configuration of the sleeve rotating type roll, the regulating roll 7 having the configuration of the sleeve rotating type roll, and In this example, 8 is a collection blade made of a magnet, which forms a magnetic field that repels the magnetic pole in the regulation roll 7, and therefore is placed on the regulation low shift 0 rotation sleeve S. This is to remove the toner from the top of the toner sleeve S that is being moved.Figure 7 shows a configuration of a magnet/sleeve rotating roll! In the above example, a voltage in which, for example, a DC voltage VD K and an alternating voltage VA are superimposed is applied as a control voltage to the regulating roll 7 in the same way as in the example of FIG. 4. A voltage application mechanism g is connected.

In the above, the rotational direction of the rotating cylindrical sleeve 8L is the same direction as the rotational direction of the photoreceptor 1 (indicated by the white arrow P in the figure) in one development area 4 as in the illustrated example; The rotation direction may proceed in the opposite direction. If the directions proceed in the same direction, the development area 4
The rotational speed of the rotating cylindrical sleeve 8L is preferably set to a rotational speed that is equal to or higher than that of the photoreceptor 1.

In addition, in the case where the regulation mechanism 6 is constituted by the regulation roll 7 as described above, the regulation roll 7 and the developing roller 3
Although it is preferable that the rotation directions proceed in opposite directions in the regulating region C where the two are opposed to each other, it is also effective that the rotation directions proceed in the same direction.

In the present invention, regulation! 11$16 is the replacement book number reference (
18) An endless belt may be used instead of the regulating roll 7. 5k as shown in No. 811.

The development time is as low as 3 (both magnet rotation!).

- When using the roll configuration, a ferromagnetic material such as iron can also be used as the magnetic member constituting the regulation roll 7. For example, a round bar-shaped regulating rod 11 made of iron or the like and having a diameter relatively smaller than that of the developing roll 3 is arranged in four stages facing the developing roll 3, or is rotated once as shown in the figure. It is also possible to adopt a configuration in which the regulating rod IIK is connected to a voltage applying mechanism E, which applies a control voltage in which, for example, a DC voltage vDk and an alternating tortoise pressure vA are superimposed.

In this example, by the action of the magnetic force of the regulating rod 11 induced by the magnet Mk and the action of the control voltage, the excess developer mainly containing magnetic toner particles charged with an unnecessary polarity is removed. *Can be separated and removed from roll 3. Furthermore, as shown in FIG.
By configuring the roller 1 to rotate around its axis, the conveying force for conveying the excess developer can be further increased (19). In addition, as shown in Fig. *S, a substantially cylindrical regulating rod 1 made of a material that can be strongly magnetized (ferromagnetic material) is used.
It is also possible to configure the regulating device II6 by providing the roller 2 such that its circumferential surface faces the developing roll 3. In this example, as specified in the specification, the regulation lot 12 is made of ferromagnetic material. A rotating magnetic field is placed on the surface, thereby achieving IA image copper regulation.

In the above, when applying a DC voltage with an alternating voltage superimposed as a control voltage (.

As mentioned above, toner particles charged with unnecessary polarity are developed.
In addition, the toner particles charged to the required polarity will also vibrate in the same way due to the alternating electric field, so the toner particles have reached a certain amount of charge on the plate. However, the repulsion of the DC voltage and the development] are caused by the insulator pressure lI! When Jt is applied, it is also effectively affected by the attractive force, so that it is not transported by the regulating roll 7 and is not disposed of (as a result, the jiHI The agent thin layer contains many toner particles having a charge amount above a certain level, and it is possible to achieve 3iIS even better than this.

Although the embodiments of the present invention have been described above, the present invention also applies to contact jJg
It can be applied to any developing method such as the II method or the non-contact m-image method. Further, the present invention is not limited to the embodiments shown in FIGS. 2 to 9. Furthermore, the feeling
Various methods can be used for applying the developing bias voltage between the light body 1 and the developing plate 3, such as applying a DC voltage or superimposing various alternating voltages on the DC voltage. It is possible to adopt a method of applying a different voltage, a method of applying various alternating voltages alone, or the like.

As described above, according to the present invention, with an extremely simple configuration, the developer conveyed to the developing area by the developer conveying body can be always controlled in an appropriate amount in a thin layer, and
Since this developer layer can be made of toner particles of the required polarity (21), very good development can be achieved.

[Brief explanation of drawings]

Figure 1 shows an example of a conventional electrostatic image developing device, and Figure 2 shows an embodiment of the electrostatic image developing device of the present invention.
14, Figures, and Figures 3 to ssi respectively show embodiments of the present invention, and Figure 9I shows still another embodiment.
- is an explanatory diagram showing. 1...Photoreceptor 2...Developer tank 3...
・ll image roll 4...development area 5...doctor blade 6...am agent amount regulation mechanism 57...regulation port 8...recovery plate 9.
...3i1gII dosage, reserve, regulation plate. 10...Cleaning blade 11.12...Regulation rod E,...Charged developer control voltage application **C...Regulation area Rei...Magnet No. 8, 9th procedural amendment ) October 83, 1945 1 Japan Patent Office Chotomi Kazuo Chikusan 1, Indication of the case Showa I + @ 2006 Fraudulent Application No. 11.3E No. 3 2.-
No. 10 Static charge / father / device 3, relationship with the person making the amendment case Zeng Xu Gang Jijin r Gaen Tokyo Shinsho section Shinsho 1 Chomaro ■ Number S quantity r electric (Name) 01? ) Small ■ Rokupo Shinko aS type regulations 4, agent 5, date of amendment order 1, -Rin・mlll page ssO bone in the ``negative 豐 班现'' tube ``positive chargeability'' is corrected.

Claims (1)

[Scope of Claims] 1) A developer transport member for transporting a monocomponent developer to a development area where an electrostatic charge image is developed, and a developer transport function disposed opposite to the developer transport member. 1. An electrostatic image developing device comprising: a developer amount regulating mechanism having a developer amount regulating mechanism #Ik, to which a charged developer control voltage #Ik is applied. -2) The electrostatic image developing device according to claim 8, item 1, wherein the developer amount regulating mechanism has a magnetic member. 3) The electrostatic charge image 3J image device according to claim 1 or 2, wherein the charging 3J agent control voltage is a DC voltage. 4) Claim 1, wherein the charged developer control voltage indicated by # is a DC voltage superimposed with an alternating voltage.
The electrostatic image developing device according to item 2 or item 2.