JPH08278703A - Wet-type image forming device - Google Patents

Abstract

PURPOSE: To achieve the satisfactory removal of liquid developer after image formation by removing the liquid developer from a developing member after development in such a manner that a cleaning liquid is supplied to a developing chamber formed from the developing member and an image carrier surface to which charges having the opposite polarity of electrified toner are applied. CONSTITUTION: The liquid developer is extracted from the developing head 22 after the development. However, the extraction of the liquid developer tends to leave the liquid developer in the developing head 22. To solve the problem, by using an electrifying charger used for the formation of an electrostatic latent image, charges having the opposite polarity of the electrified toner 44 of the developer remaining in the developing head 22 are applied to recording paper 1 prior to the cleaning of the developing head 22. Then, by using a pump 27, etc., the cleaning liquid in a cleaning-liquid tank 41 is supplied to the liquid developer chamber 21 formed from the recording paper 1 electrified to the opposite polarity of the electrified toner 44 and the developing head 22 abutting on the recording paper 1. Thus, the liquid developer, where the electrified toner 44 is suspended in the liquid carrier, remaining in the liquid developer chamber 21 is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile and a printer, and more specifically, a developing solution for supplying an electrostatic latent image formed on the surface of an image carrier. The present invention relates to a wet image forming apparatus that develops and cleans the developing member with a cleaning liquid.

[0002]

2. Description of the Related Art A wet image forming apparatus for forming an image by developing an electrostatic latent image formed on the surface of an image bearing member with a developing solution in which toner is dispersed in a liquid carrier supplied by a developing member is known. Are known. However, according to such a wet-type image forming apparatus, the developing solution remains on the developing member after the image formation is completed, and the toner in the remaining developing solution is fixed to the developing member, so that the image forming performed thereafter is prevented. There was a problem. Here, when a developing head having a groove is used as the developing member, the developer is likely to remain in the groove and the toner is apt to be fixed to the groove, so that the image formation to be performed thereafter tends to be particularly hindered.

Therefore, in Japanese Patent Laid-Open No. 61-179476, in order to prevent the developing solution from remaining on the developing member, an air flow is sent to the developing member after the developing operation is completed to remove the developing solution from the developing member. A wet image forming apparatus provided with a mechanism for removing it has been proposed (hereinafter referred to as a known apparatus 1). According to the known device 1, by removing the developer from the developing member, it is possible to prevent the toner from sticking to the developing member to some extent.

Further, Japanese Patent Laid-Open No. 1-185569 proposes a wet type image forming apparatus in which a cleaning liquid is made to flow through a developing member after development to wash away the developing liquid remaining on the developing member (hereinafter, known device). 2). By using the known device 2, it is possible to prevent the toner from sticking to the developing member to some extent.

Further, in Japanese Patent Laid-Open No. 4-51068, a voltage having a polarity opposite to that of the toner particles is applied to the developing member after image formation to dissociate the toner particles remaining on the developing member from the developing electrode. Then, a wet image forming apparatus has been proposed which removes the developer containing toner particles dissociated from the developing member by sending air to the developing member thereafter. (Hereinafter, known device 3). By using the known device 3, it is possible to prevent the toner from sticking to the developing member.

[0006]

However, even if the known apparatus 1 or the known apparatus 2 is used, the developing solution cannot be completely removed from the developing member in the state where the development is completed, and repeated image formation is performed. If this is done, toner will stick to the developing member. In particular, when a developing head having a groove is used as the developing member, it is difficult to remove the developing solution remaining in the groove, and toner sticking to the groove is apt to occur, so that the subsequent image formation is not hindered. Inevitable. Further, when the known device 3 is used, it is necessary to provide a special voltage generating circuit for applying a voltage having a polarity opposite to that of the toner particles to the developing member. As a result, the structure of the device becomes complicated and the device becomes expensive.

The present invention has been made in view of the above problems, and an object thereof is to favorably remove the developer from the developing member after completion of image formation while having a simple apparatus structure. However, it is another object of the present invention to provide a wet-type image forming apparatus that can prevent the subsequent image formation from being adversely affected.

[0008]

In order to achieve the above-mentioned object, a wet image forming apparatus according to a first aspect of the present invention applies a charge applying means for applying an electric charge to a surface of an image carrier and a surface of the image carrier. A developing member that is in contact with each other to form a developing solution chamber, and a developing solution in which a charged toner is dispersed in a liquid carrier are supplied to the developing solution chamber, and the static electricity formed on the surface of the image carrier by the charge applying unit. A developing solution supplying means for developing the latent image, a cleaning solution supplying means for supplying a cleaning solution to the developing solution chamber to clean the developing solution remaining on the developing member, and the image carrier relative to the developing member. Cleaning for supplying the cleaning solution to the developing solution chamber formed by the image carrier moving means for moving, the surface of the image carrier in the state where the charge having the characteristic opposite to that of the charged toner is applied, and the developing member. And a control means It is an feature.

A wet image forming apparatus according to a second aspect is the first aspect.
In the wet image forming apparatus, the cleaning control means controls the image carrier moving means to move the image carrier to the developing member while the cleaning solution is being supplied to the developing solution chamber. It is characterized in that it is a relative movement.

A wet image forming apparatus according to a third aspect is the first aspect.
A wet image forming apparatus, wherein the cleaning liquid supply means is
The cleaning solution can be supplied to the developing solution chamber in different directions, and the cleaning control means can control the cleaning solution supply means to select the supply direction of the cleaning solution supplied to the developing solution chamber. It is characterized by being

A wet image forming apparatus according to a fourth aspect is the first aspect.
A wet image forming apparatus, wherein the cleaning liquid supply means is
The cleaning solution can be supplied to the developing solution chamber in different directions, and the cleaning control unit controls the cleaning solution supply unit to supply the cleaning solution to the developing solution chamber each time the cleaning solution is supplied to the developing solution chamber. It is characterized in that the supply method is reversed.

A wet image forming apparatus according to a fifth aspect is the first aspect.
A wet image forming apparatus, wherein the cleaning liquid supply means is
The cleaning solution can be supplied to the developing solution chamber in different directions, and the cleaning control unit controls the cleaning solution supply unit to supply the cleaning solution to the developing solution chamber once during the supply of the cleaning solution. It is characterized in that the supply direction of the cleaning liquid is reversed.

According to a sixth aspect of the present invention, there is provided a wet image forming apparatus, wherein a charge applying means for applying an electric charge to the surface of the image bearing member, a developing member contacting with the surface of the latent image bearing member to form a developer chamber, A developing solution supplying means for supplying a developing solution in which charged toner is dispersed in a liquid carrier to the developing solution chamber to develop the electrostatic latent image formed on the surface of the image carrier by the charge applying means; After completion of the above, a cleaning solution supplying means for supplying a cleaning solution to the developing solution chamber to clean the developing solution remaining on the developing member, and an image carrier moving means for relatively moving the image carrier with respect to the developing member. , A vibrating vibrating member provided in the developer chamber, a vibrating member for imparting vibration to the vibrating member, and a vibrating member control for vibrating the vibrating member at desired timing by controlling the vibrating member. And means It is characterized in.

A wet image forming apparatus according to a seventh aspect is the sixth aspect.
In the wet image forming apparatus, the vibrating member control means vibrates the vibrating member while the developing solution supply means supplies the cleaning liquid to the developing solution chamber. To do.

A wet image forming apparatus according to an eighth aspect is the sixth aspect.
The wet image forming apparatus according to claim 1, further comprising cleaning control means capable of controlling the cleaning solution supply means to stop the flow of the cleaning solution in a state where the cleaning solution is filled in the developing solution chamber, The member control means vibrates the vibrating member in a state where the developing solution chamber is filled with the cleaning liquid and the flow of the cleaning liquid is stopped.

A wet image forming apparatus according to a ninth aspect is the sixth aspect.
Of the wet image forming apparatus, wherein the vibrating member control means develops the electrostatic latent image formed on the image bearing member into the developing solution chamber by the developing solution supply means after completion of development. The vibrating member is vibrated before the end of the liquid supply.

[0017]

In the wet image forming apparatus according to any one of claims 1 to 5, the developing solution is removed from the developing member after the development is completed, so that an image having a charge having a characteristic opposite to that of the charged toner is applied to the developing member. This is done by supplying a cleaning liquid to a developer chamber formed by the surface of the carrier. For this reason, the charged toner remaining on the developing member is electrostatically attracted to the image carrier, and is satisfactorily removed. Further, since the charged toner adheres to the surface of the image carrier, the concentration of the charged toner in the cleaning liquid does not increase, and the defective removal of the charged toner from the developing member due to the increase in the toner concentration during the supply of the cleaning liquid is prevented. Are well removed. In addition, the charged toner that adheres to the portion of the developing member that is in direct contact with the image carrier is also satisfactorily removed by being electrostatically adsorbed on the surface of the image carrier.

Further, in the wet image forming apparatus of the second aspect, the developing solution chamber is formed by the developing member and the image carrier which moves relative to the developing member, and the cleaning solution is supplied to the developing solution chamber. By doing so, the developing solution is removed from the developing member. Therefore, the developing solution chamber is always formed by the image carrier on which the charged toner does not adhere, and the charging that occurs when the developing solution chamber is formed by the image carrier that has reached the saturation amount of toner adhesion. Adhesion of the toner does not occur and the charged toner can be removed particularly well. Further, the charged toner attached to the portion of the developing member that is in direct contact with the image bearing member is also particularly good due to the mechanical friction with the image bearing member and the contact of the image bearing member to which the charged toner is not always attached. Will be removed.

Further, particularly in the wet image forming apparatus according to the third aspect, the cleaning control means controls the cleaning liquid supply means,
The cleaning solution is supplied to the developing solution chamber in different directions. For this reason,
May occur when supplying the cleaning liquid from one direction,
For example, it is possible to prevent the charged toner from remaining in a portion of the developer chamber where the developer is hard to come into contact, such as the vicinity of the inlet / outlet of the developer, so that the charged toner remains in the portion.

Further, particularly in the wet image forming apparatus according to the fourth aspect, the supply direction of the cleaning solution is reversed every time the cleaning solution is supplied to the developing solution chamber. For this reason, in the previous supply of cleaning liquid, the cleaning liquid also hits the areas where it is difficult to reach,
The charged toner is satisfactorily removed over the entire area of the developer chamber.

Further, particularly in the wet type image forming apparatus of the fifth aspect, the supply direction of the cleaning liquid is reversed during the single supply operation of the cleaning liquid to the developing solution chamber. For this reason, the cleaning liquid is applied to the portion where the cleaning liquid is hard to contact in the supply direction of the cleaning liquid before being reversed, and the charged toner is satisfactorily removed over the entire area of the developing solution chamber.

Further, in the wet image forming apparatus according to any one of claims 6 to 9, the vibrating member provided in the developing solution chamber in which the developing solution is supplied is vibrated by the vibrating means. The charged toner remaining in the developer chamber is vibrated and vibrated to disperse the charged toner in the cleaning liquid or the developing liquid. Therefore, removal of the cleaning solution may be insufficient by simply supplying the cleaning solution to the developing solution chamber.
The charged toner that has settled in the developer chamber and the charged toner that is about to stick to the developer chamber are also removed satisfactorily.

Further, particularly in the wet image forming apparatus of the seventh aspect, the vibrating member vibrates in the developing solution chamber while the cleaning solution is being supplied to the developing solution chamber. Therefore, the vibrating member vibrates the charged toner and the cleaning liquid is supplied to generate the cleaning liquid flow in the developing liquid chamber, which synergistically removes the charged toner from the developing liquid chamber. It

Further, particularly in the wet image forming apparatus of the eighth aspect, the vibrating member provided in the developing solution chamber vibrates in a state where the developing solution chamber is filled with the cleaning solution. Therefore, the vibration is satisfactorily transmitted to the entire wall surface of the developer chamber,
Even the charged toner remaining on any part of the wall surface is well removed.

Further, particularly in the wet type image forming apparatus of claim 9, after the development of the electrostatic latent image formed on the image carrier is completed, and the supply of the developing solution to the developing solution chamber is completed. Before, the vibrating member provided in the developer chamber vibrates.
Therefore, vibration is applied to the charged toner adhered to the wall surface of the developer during development, and the charged toner is dispersed in the developer. Therefore, the charged toner is prevented from remaining in the developer chamber. (Hereinafter, margin)

[0026]

【Example】

[First Embodiment] A first embodiment in which the present invention is applied to a wet electrophotographic copying machine (hereinafter referred to as a copying machine) will be described below. FIG. 1 is a front view showing a schematic configuration of a copying machine according to this embodiment. This copying machine is equipped with a charging charger as an electric charge applying means for applying an electric charge to the surface of the recording paper 1 as an image carrier to form an electrostatic latent image on the surface, and an exposure device. Further, the copying machine includes a developing device 2 for developing the electrostatic latent image with a developing solution in which charged toner is dispersed in a liquid carrier, and a cleaning solution for cleaning the remaining developing solution with a cleaning solution after the development is completed. The cleaning device 4 as a supply unit, the recording paper 1 to the developing head 22 (developing device 1
(Which is one of the components of the above), a clamp drum or the like (not shown) is provided as an image carrier moving means for moving the image carrier relatively.

The developing device 2 is supplied to a developing head 22 and a developing solution chamber 21 as a developing member which comes into contact with the recording paper 1 having an electrostatic latent image formed on its surface to form a developing solution chamber 21. A developer tank 23 in which the developer is stored, a developer supply pipe 24 that is a flow path when the developer is supplied from the developer tank 23 to the developer chamber 21, and a first flow path including an electromagnetic three-way valve. Developing solution supply pipe 24 through the selection valve 25
Common supply pipe 26 communicating with the developing tank and the developer tank 2
A negative pressure pump 27 for sucking the developing solution stored in No. 3 into the developing solution chamber 21 is provided. Here, the developer tank 23,
The electrostatic latent image formed on the surface of the recording paper 1 by the developing supply pipe 24, the first flow path selection valve 25, the common supply pipe 26, and the negative pressure pump 27 supplying the developing solution to the developing solution chamber 21. Functioning as a developer supply means for developing. Further, the developing device 2 uses the developing solution tank 2 to store the developing solution used for developing.
The common recovery pipe 28 for recovering to the common recovery pipe 3 and the common recovery pipe 2 through the second flow path selection valve 29 composed of an electromagnetic three-way valve.
8 is provided with a developer collecting pipe 30.

As the developing head 22, it is possible to use a member having a single groove or a plurality of grooves at the portion contacting the recording paper 1, and the recording paper 1 is brought into contact with the member from above to make a closed state. A developer chamber 21 can be formed. Further, the negative pressure pump 27 is preferably provided downstream of the developing solution chamber 21 in the flowing direction of the developing solution or the cleaning solution. If the negative pressure pump 27 is provided at such a position, a negative pressure is generated in the flow path only when the recording paper 1 contacts the developing head 22 and the developing solution chamber 21 is formed. Therefore, a negative pressure is not generated in the flow path in a state where the recording paper 1 is not in contact with the developing head 22, that is, a state where the developing solution chamber 21 is not formed, and the developing solution does not spill out from the groove. .

The cleaning device 4 is for cleaning the developing solution remaining on the developing head 22 after the development is completed. The cleaning solution tank 41 stores the cleaning solution, and the cleaning solution is transferred from the cleaning solution tank 41 to the developing head 22. A cleaning liquid supply pipe 42 that is a flow path when supplied, a common supply pipe 26 that communicates with the cleaning liquid supply pipe 42 via the first flow path selection valve 25, and the cleaning liquid stored in the cleaning liquid tank 41 to the developing head. 22 and a negative pressure pump 27 for sucking the same. As can be seen from this description, the first flow path selection valve 25, the common supply pipe 26, and the negative pressure pump 27 also serve as members for supplying the developing solution to the developing solution chamber 23 for supplying the cleaning solution.

Further, the cleaning device 4 communicates with the common recovery pipe 28 via the common recovery pipe 28 for recovering the cleaning liquid used for cleaning into the waste liquid tank 43, and the second flow path selection valve 29. The cleaning liquid recovery pipe 44 is provided. As can be seen from this description, the second flow path selection valve 2
9, the common recovery pipe 28, and the negative pressure pump 27 also serve as members for recovering the developing solution into the developing solution chamber 23 for recovering the cleaning solution. Further, as the above-mentioned cleaning liquid, a liquid carrier such as isoper which forms a developing liquid is usually used, but a dedicated cleaning liquid can also be used.

The operation of the copying machine configured as described above will be described. In this copying machine, an electrostatic latent image formed on the surface of the recording paper 1 by an exposure device (not shown) is applied to the developing device 2
And develop to form an image. That is, the recording paper 1 on which the electrostatic latent image is formed is conveyed by the clamp drum and abuts on the developing head 22 to form the developing solution chamber 21, and the developing solution is supplied to the developing solution chamber 21 to cause the electrostatic discharge. The latent image is developed. To supply the developing solution to the developing solution chamber, first, the first flow path selection valve 25 is connected to the developing solution supply pipe 24 and the common supply pipe 2.
6 and the second flow path selection valve 29 is in a state where the common recovery pipe 28 and the developer recovery pipe 30 are in communication, and the developer tank 23 is connected to the developer supply pipe 2
4, flow through the first flow path selection valve 25, the common supply pipe 26, the developer chamber 21, the common recovery pipe 28, the second flow path selection valve 29, and the developer recovery pipe 30 to reach the developer tank again. Forming a path. Then, in the state in which the flow path is formed, the negative pressure pump 27 is driven to flow the developer stored in the developer tank 23 into the flow path, thereby supplying the developer to the developer chamber 21. Is done. The recording paper 1 which has been developed by the above operation is subjected to a fixing process if necessary, and then discharged to the outside of the apparatus.

Next, the developing solution is drained from the developing head 22 which has completed development. However, the developer may remain on the developing head 22 only by removing the developer. Therefore, the developing head 22 is cleaned with a cleaning liquid.
The operation of this copying machine during cleaning will be described below.

Prior to cleaning the developing head 22, an electric charge having a polarity opposite to that of the charged toner contained in the developing solution remaining in the developing head 22 is recorded by the charging charger used for forming the electrostatic latent image. It is applied to the paper 1. The recording paper 1 is conveyed by a clamp drum (not shown) and abuts on the developing head 22 to form a developing solution chamber 21, and a cleaning solution is supplied to the developing solution chamber 21 so that the developing head 22 moves. To be washed. In order to supply the cleaning liquid to the developing solution chamber 21, first, the first flow path selection valve 25 is brought into a state where the cleaning liquid supply pipe 42 and the common supply pipe 26 are communicated with each other, and the second flow path selection valve 29 is commonly recovered. With the pipe 28 and the cleaning liquid recovery pipe 30 communicating with each other,
Waste liquid from the cleaning liquid tank 41 through the cleaning liquid supply pipe 42, the first flow path selection valve 25, the common supply pipe 26, the developing solution chamber 21, the common recovery pipe 28, the second flow path selection valve 29, and the cleaning liquid recovery pipe 30. A flow path leading to the tank 43 is formed. Then, in a state where the flow path is formed,
By driving the negative pressure pump 27 and flowing the cleaning liquid stored in the cleaning liquid tank 23 into the flow path, the developing liquid chamber 21
The cleaning liquid is supplied to the.

During the cleaning operation, as described above, the developing solution chamber 21 is formed by the recording paper 1 to which the charge having the characteristic opposite to that of the charged toner is applied, so that the charged toner may remain on the developing head 22. The developer can be removed satisfactorily. Hereinafter, this point will be described. FIG. 2 is an explanatory diagram schematically showing how the developing solution is removed from the developing head 22. 2 is an enlarged view of the AA cross section in FIG.

As shown in FIG. 2, the developing head 22 from which the developing solution has been removed and the developing solution has been removed has the charged toner 4
4 (hereinafter referred to as charged toner) remains. The charged toner 44 can be removed only by supplying the cleaning solution to the developing solution chamber 21, but a part thereof may remain. Therefore, in this copying machine, the recording paper 1 forming the developing solution chamber 21 is charged with a charge (negative charge) having a polarity opposite to that of the charged toner 44, and the charged toner 44 is electrostatically adsorbed to achieve good charging. Realizes the removal of toner. Further, since the charged toner 44 in the developer chamber 22 adheres to the recording paper 1, the cleaning liquid in the developer chamber 22 is less likely to be saturated with the toner, so that the charged toner can be removed well.
When the cleaning solution reaches the downstream of the developing solution chamber 21, the amount of the toner dispersed in the cleaning solution becomes close to the saturation amount, and the toner is not easily removed satisfactorily. However, this copier can prevent such an adverse effect. Further, even if the amount of the cleaning liquid supplied is small, the cleaning liquid is less likely to be saturated, so that the residual toner can be removed well even with a small amount of the cleaning liquid. Further, by applying an electric charge to the recording paper 1, the charged toner 44 attached to the convex portion 45, which is a portion of the developing head 22 where the cleaning liquid does not pass, can also be removed. After the above cleaning operation is completed, the cleaning liquid is drained from the developing liquid chamber 21, and the cleaning liquid is squeezed from the developing head 22.

In the apparatus described above, the recording paper to which a charge having a polarity opposite to that of the charged toner 44 is applied while the cleaning liquid is being supplied to the developing solution chamber 21, that is, during the cleaning operation. It is desirable that 1 is conveyed by a clamp drum (not shown) and is moved relative to the developing head 22. If the recording paper 1 is conveyed, the developer chamber 21
Is always formed in a portion of the recording paper 1 where the charged toner 44 is not attached, and the charged toner 44 is adsorbed well.

Further, although the developing head 22 having three grooves is used in the apparatus described above (see FIG. 2), the number of grooves may be appropriately determined. Further, in the above description, the case where the polarity of the charged toner 4 is positive and the polarity of the charge applied to the recording paper 1 is negative has been described as an example, but the polarity of the charged toner 44 is negative and the recording paper 1 is negative. 1
The polarity of the electric charge given to may be positive.

Further, in the apparatus described above,
An electric charge having a polarity opposite to that of the charged toner is applied to the recording paper 1 by using a charging charger, but a device for transferring the electric charge from the charged photoconductor or a stylus head for directly applying the electric charge to the recording paper 1 is used. You can also Further, whichever device is used to apply the electric charge to the recording paper 1, if the device and the device for forming the electrostatic latent image on the recording paper 1 are combined, the manufacturing cost of the device can be suppressed. While you can
The device can be downsized.

In the copying machine described above, the ultrasonic vibrator 50 as a vibrating member and the piezoelectric element 51 as a vibration applying means for applying ultrasonic vibration to the ultrasonic vibrator 50 are provided in the developer chamber 21. May be. FIG. 3 is an explanatory diagram showing an enlarged schematic configuration of the developing head 22 provided with the ultrasonic transducer 50 and the piezoelectric element 51. The ultrasonic transducer 5
When 0 and the piezoelectric element 51 are provided, it is not always necessary to apply a charge having a polarity opposite to that of the charged toner 44 to the surface of the recording paper 1, but if the charge is applied, better removal of the charged toner is realized. . The piezoelectric element 51 vibrates ultrasonically when a voltage is applied from a power source (not shown) and transmits the vibration to the ultrasonic transducer 50. Further, the ultrasonic vibrator 50 transmits ultrasonic vibration to the cleaning liquid in the developing solution chamber 21 and ultrasonically vibrates the cleaning liquid.

In the copying machine equipped with the ultrasonic vibrator 50 and the piezoelectric element 51, the ultrasonic vibrator 51 is ultrasonically vibrated in the state where the developing solution chamber 21 is filled with the cleaning liquid, and the vibration is converted into the cleaning liquid. The transfer causes the cleaning liquid to vibrate. The charged toner 44 attached to the developing head 22 by this operation
Since kinetic energy is applied to the toner to disperse the charged toner in the cleaning liquid, the charged toner 44 is satisfactorily removed from the developing head 22.

Here, when the developing solution chamber 22 is filled with the cleaning solution, even if ultrasonic vibration is applied to the developing solution while the cleaning solution is flowing in the developing solution chamber 22, Two
Even if ultrasonic vibration is applied to the cleaning liquid stopped in 2,
It doesn't matter which one. That is, the cleaning solution in the developing solution chamber 22 is supplied to the developing solution chamber 22 while the cleaning solution is being supplied to the developing solution chamber 22. It may be stopped in the room 22. When ultrasonic vibration is applied to the flowing cleaning liquid, the charged toner 44 is satisfactorily removed from the developing head 22 due to the synergistic action of the cleaning liquid vibrating and the cleaning liquid flowing. Further, when vibration is applied to the stopped developing solution, the cleaning solution is surely attached to the entire wall surface of the developing solution chamber 22, so that the developing head 2
The blackout toner 44 is satisfactorily removed from the entire area 2. To stop the cleaning liquid in the developer chamber 22, the negative pressure pump 29
Should be stopped.

In the above description, the developer chamber 21
Although the ultrasonic vibration was applied to the cleaning liquid in the state of being filled with the cleaning liquid, the ultrasonic vibration may be applied to the developing liquid when the developer chamber 21 is filled with the developing liquid. That is, after the development of the electrostatic latent image formed on the surface of the recording paper 1 is completed and when the developing solution chamber 21 is filled with the developing solution, ultrasonic waves are applied to the developing solution. Vibration may be applied by the vibrator 50. Specifically, the time from the start of the development of the electrostatic latent image to the completion of the development is measured in advance, and the vibration of the ultrasonic transducer 50 is started at the same time as the completion of the development operation. In this case, the charged toner 44 attached to the developing head 22 is dispersed in the developing solution,
It becomes difficult to remain in 4.

In the copying machine described above, the ultrasonic transducer 50 vibrates in the horizontal direction in FIG. 2, but it may vibrate in the vertical direction in FIG. Further, instead of the structure in which the ultrasonic transducer 50 and the piezoelectric element 51 are embedded in the developing head 22, a configuration may be adopted in which both members are attached to the outside of the developing head 22 and vibration is applied to the developing head 22 from the outside. it can.

[Second Embodiment] A second embodiment in which the present invention is applied to a wet electrophotographic copying machine (hereinafter referred to as a copying machine) will be described below. FIG. 4 is a front view showing a schematic configuration of the copying machine according to the present embodiment. This copying machine is the first embodiment.
Although the configuration and the operation of the developing device 2 and the cleaning device 4 are partially different from those of the copying machine according to the above, the other configurations and operations are common. Therefore, in the following description, only the differences from the copying machine of the first embodiment will be described, and the description of the common parts will be omitted.

The developing device 2 for this copying is the first embodiment.
Common supply pipe 26 in addition to the members of the developing device
Third flow path selection valve 71 provided in a supply communication pipe 70 that communicates between the developer chamber 21 and the developer chamber 21, and a fourth flow path provided in a recovery communication pipe 72 that communicates the developer chamber 21 with the common recovery pipe 28. A selection valve 73, a first backflow pipe 74 that connects the common supply pipe 26 and the fourth flow path selection valve 73, and a third
Second for connecting the flow path selection valve 71 and the common recovery pipe 29
The backflow pipe 75 is provided, and the liquid can be caused to flow in different directions in the developer chamber 21 by using the single pump 27.

In the copying machine, in order to flow the cleaning liquid from the left to the right in the drawing, first, the first flow path selection valve 25 is brought into a state in which the cleaning liquid pipe 42 and the common supply pipe 26 are communicated with each other.
The second flow path selection valve 29 connects the common recovery pipe 28 and the waste liquid tank 43, the third flow path selection valve 71 connects the common supply pipe 26 and the developer chamber 21, and The four-passage selection valve 73 is brought into a state in which the developer chamber 21 and the common recovery pipe 28 are communicated with each other. That is, from the cleaning liquid tank 41, the cleaning liquid supply pipe 42, the first flow path selection valve 25, the common recovery pipe 26, the third flow path selection valve 71, the developing solution chamber 21, the fourth flow path selection valve 73, the common recovery pipe. Two
8 and the flow path to the waste liquid tank 43 via the second flow path selection valve 29. And in this state, the negative pressure pump 2
When a negative pressure is generated in the cleaning liquid 7, the cleaning liquid flows through the flow path, and the cleaning liquid flows in the developing solution chamber 21 from left to right in the drawing.

On the other hand, when flowing the cleaning liquid from right to left in the figure, first, the first flow path selection valve 25 is placed in a state where the cleaning liquid pipe 42 and the common supply pipe 26 are communicated with each other, and the second flow path selection valve 29. In a state in which the common recovery pipe 28 and the waste liquid tank 43 are communicated with each other, the third flow passage selection valve 71 is in a state in which the common supply pipe 26 and the second backflow pipe 75 are communicated with each other, and the fourth flow passage selection valve 73 is in a communication state. The first reverse flow pipe 74 and the common recovery pipe 2
8 is in communication. That is, from the cleaning liquid tank 41, the cleaning liquid supply pipe 42, the first flow path selection valve 2
5, common supply pipe 26, first reverse flow pipe 74, fourth flow path selection valve 73, developer chamber 21, third flow path selection valve 71, second reverse flow pipe 75, common recovery pipe 28, and second flow path A flow path is formed to reach the waste liquid tank 43 via the selection valve 29. Then, when a negative pressure is generated in the negative pressure pump 27 in this state, the cleaning liquid flows through the flow path, and the cleaning liquid flows in the developing solution chamber 21 from right to left in the drawing.

In this copying machine, the flow path selection valves are driven as described above to appropriately reverse the cleaning liquid supply direction in the developing solution chamber 21. By reversing the supply direction of the cleaning liquid,
When the cleaning liquid is supplied only in one direction, the line liquid is likely to contact the portion of the developing head 22 where the cleaning liquid is hard to contact, and the charged toner 44 is reliably removed from the developing head 22.

Regarding the timing of reversing the direction of supplying the cleaning solution, it may be reversed every time the cleaning solution is supplied to the developing solution chamber 21, or may be reversed during one operation of supplying the developing solution. good. If you use this copier,
The direction in which the developing solution is supplied to the developing solution chamber can also be reversed. However, in the case of supplying the developing solution, the first flow path selecting valve 25 is in a state of connecting the developing solution supply pipe 24 and the common supplying pipe 26, and the second flow path selecting valve 29 is the common collecting pipe 28 and the developing solution. The recovery pipe 30 is brought into a communication state.

The copying machine according to the first embodiment and the second copying machine
In the copying machine according to the embodiment of the present invention, each flow path selection valve and the negative pressure pump 2 are provided.
7. A microprocessor for operating a clamp drum (not shown) or the like as described above is provided, and this microprocessor functions as a cleaning control means and a vibration member control means.

[0051]

According to the inventions of claims 1 to 5,
By electrostatically adhering the charged toner to the image carrier charged with the opposite characteristic to the charged toner, the charged toner is satisfactorily removed from the developing member. Therefore, it is possible to prevent the charged toner remaining on the developing member from being fixed to the developing member and adversely affecting the subsequent image formation.

According to the second aspect of the present invention, the developing solution chamber is formed by the developing member to which the charged toner is not always adhered, and the toner of the image bearing member is directly contacted with the portion of the developing member. The charged toner is removed particularly well from the developing member by contacting the portions to which the toner does not adhere. Therefore, it is possible to particularly well prevent the power failure toner remaining on the developing member from being fixed to the developing member and adversely affecting subsequent image formation.

According to the third aspect of the present invention, by supplying the cleaning liquid from different directions, it is difficult to remove the charged toner even when the cleaning liquid is supplied from one direction of the developer chamber. Are well removed. For this reason, it is particularly preferable to prevent the charged toner from adhering to the developing solution chamber and adversely affecting the subsequent image formation.

According to the fourth aspect of the present invention, the supply direction is switched every time the cleaning liquid is supplied to the developing solution chamber, so that it is good even from the portion where the removal of the charged toner was insufficient at the previous supply of the cleaning liquid. The charged toner is removed. For this reason, it is particularly well-prevented that the charged toner adheres to the developer chamber and adversely affects the image formation performed thereafter.

According to the invention of claim 5, the supply direction of the cleaning liquid is reversed during the single supply operation of the cleaning liquid, so that the removal of the charged toner is insufficient in the supply direction of the cleaning liquid before being reversed. The charged toner is satisfactorily removed from the exposed portion. For this reason, it is particularly well-prevented that the charged toner adheres to the developer chamber and adversely affects the image formation performed thereafter.

According to the sixth to ninth aspects of the invention, the vibrating member vibrates in the developing solution chamber, so that the charged toner remaining in the developing solution chamber and the charging that is about to adhere to the wall surface of the developing solution chamber. The toner is also removed well. Therefore, it is possible to prevent the charged toner from remaining in the developing solution chamber and sticking to the developing member to adversely affect the subsequent image formation.

According to the invention of claim 7, the vibration of the charged toner by the vibrating member and the fact that the cleaning liquid is supplied to generate the cleaning liquid flow in the developing liquid chamber synergize with each other. The charged toner is removed particularly well from the. For this reason, it is particularly well-prevented that the charged toner remains in the developing solution chamber and that the charged toner adheres to the developing member and adversely affects subsequent image formation.

According to the eighth aspect of the present invention, the vibrating member provided in the developing solution chamber vibrates in the developing solution chamber filled with the cleaning solution, so that the charged toner can be satisfactorily charged from the entire area of the developing solution chamber. Are removed. For this reason, it is particularly well-prevented that the charged toner remains in the developing solution chamber and that the charged toner adheres to the developing member and adversely affects subsequent image formation.

According to the invention of claim 9, the vibrating member provided in the developing solution chamber vibrates after the developing operation is completed and before the supply of the developing solution to the developing solution chamber is completed. , The charged toner adhering to the wall surface of the developer chamber is dispersed in the developer. Therefore, it is possible to prevent the charged toner from remaining in the developing solution chamber and adhering to the developing member, which adversely affects the subsequent image formation.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of a copying machine according to a first embodiment.

FIG. 2 is an explanatory diagram showing a state in which a developing solution is removed from a developing head of the copying machine.

FIG. 3 is an explanatory diagram showing a developing head provided with an ultrasonic transducer and a piezoelectric element.

FIG. 4 is a front view showing a schematic configuration of a copying machine according to a second embodiment.

[Explanation of symbols]

 1 recording paper 2 developing device 21 developing solution chamber 22 developing head 23 developing solution tank 24 developing solution supply pipe 25 first flow path selection valve 26 common supply pipe 27 negative pressure pump 28 common recovery pipe 29 second flow path selection valve 30 recovery Pipe 4 Cleaning device 41 Cleaning liquid tank 42 Cleaning liquid supply pipe 43 Waste liquid tank 44 Charged toner 45 Convex portion 50 Ultrasonic transducer 51 Piezoelectric element 70 Supply communication pipe 71 Third flow path selection valve 72 Recovery communication pipe 73 Fourth flow path selection valve 74 First Backflow Pipe 75 Second Backflow Pipe

Claims (9)

[Claims] 1. A charge applying means for applying an electric charge to the surface of an image carrier, a developing member for contacting the surface of the image carrier to form a developer chamber, and a toner charged to a liquid carrier in the developer chamber. Is supplied to the developing solution chamber, and a developing solution is supplied to the developing solution chamber to develop the electrostatic latent image formed on the surface of the image carrier by the charge applying means. Cleaning liquid supply means for cleaning the developing solution remaining on the developing member, image carrier moving means for relatively moving the image carrier with respect to the developing member, and a state in which a charge having a characteristic opposite to that of the charged toner is applied. A wet image forming apparatus comprising: a cleaning control unit configured to supply the cleaning liquid to the developing chamber formed by the surface of the image carrier and the developing member. 2. The cleaning control means controls the image carrier moving means to move the image carrier relative to the developing member while the cleaning solution is being supplied to the developing solution chamber. The wet image forming apparatus according to claim 1, wherein the wet image forming apparatus is a device. 3. The cleaning solution supply means is capable of supplying the cleaning solution to the developing solution chamber in different directions, and the cleaning control means controls the cleaning solution supply means to the developing solution chamber. The wet image forming apparatus according to claim 1, wherein the supply direction of the cleaning liquid to be supplied is selectable. 4. The cleaning solution supply means is capable of supplying cleaning solution to the developing solution chamber in mutually different directions, and the cleaning control means controls the cleaning solution supply means to cause the developing solution chamber to operate. The wet image forming apparatus according to claim 1, wherein the method of supplying the cleaning liquid is reversed every time the cleaning liquid is supplied to. 5. The cleaning solution supply means is capable of supplying the cleaning solution to the developing solution chamber in mutually different directions, and the cleaning control means controls the cleaning solution supply means to control the developing solution chamber. The wet image forming apparatus according to claim 1, wherein the supply direction of the cleaning liquid is reversed while the cleaning liquid is supplied to the cleaning liquid once. 6. A charge applying means for applying an electric charge to the surface of the image bearing member, a developing member which abuts on the surface of the latent image bearing member to form a developer chamber, and a liquid carrier charged in the developer chamber. A developing solution supplying means for supplying a developing solution in which toner is dispersed and developing the electrostatic latent image formed on the surface of the image carrier by the charge applying means, and the developing solution chamber after the development is completed. A cleaning solution supplying means for supplying a cleaning solution to the developing member to clean the developing solution remaining on the developing member, and an image carrier moving means for relatively moving the image carrier with respect to the developing member,
A vibrating vibrating member provided in the developer chamber, a vibrating means for imparting vibration to the vibrating member, and a vibrating member control means for controlling the vibrating means to vibrate the vibrating member at a desired timing. A wet image forming apparatus comprising: 7. The vibrating member control means vibrates the vibrating member while the cleaning solution is being supplied to the developing solution chamber by the developing solution supply means. Wet image forming apparatus. 8. A vibrating member control means, comprising: a cleaning control means capable of controlling the cleaning liquid supply means to stop the liquid flow of the cleaning liquid in a state where the developing solution chamber is filled with the cleaning liquid. 7. The wet image forming apparatus according to claim 6, wherein the vibrating member is vibrated in a state where the developing solution chamber is filled with a cleaning liquid and the flow of the cleaning liquid is stopped. 9. The vibrating member control means supplies the developing solution to the developing solution chamber after completion of development of the electrostatic latent image formed on the image bearing member and by the developing solution supply means. The wet image forming apparatus according to claim 6, wherein the vibrating member is vibrated before the end.