JPH07261559A - Wet image forming device - Google Patents

Abstract

PURPOSE:To prevent the adverse effect on a formed image caused by the sticking of the residual toner occurring in a wet image forming device by uniformly electrifying a latent image carrier with an electrifier, and feeding a liquid carrier to a developing device from a liquid carrier feed section at the time of washing. CONSTITUTION:A photoreceptor drum 1 is rotatively driven in the direction of an arrow (a) at a constant speed, and the outer periphery surface of the photoreceptor drum 1 is uniformly electrified in darkness by a main charger 2. The developing roller 52 of a developing device 5 is rotatively driven in the direction of an arrow (b) opposite to the rotating direction of the photoreceptor drum 1. A developer dispersed with a toner in a liquid carrier is fed from a developer feed section 54 at the time of image formation, and the liquid carrier is fed from a liquid carrier feed section 10 provided above the developing roller 52 at the time of washing. The liquid carrier is accumulated in a wedge section 56 formed by the developing roller 52 and a scraper 55, and it is fed to the portion where the photoreceptor drum 1 and the developing roller 52 face each other by the rotation of the developing roller 52.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention develops a latent image formed on a latent image bearing member into a visible particle image by developing the latent image with a developer in which a toner, which is a visible particle, is dispersed in a liquid carrier. The present invention relates to a wet image forming apparatus that transfers this visible particle image onto a copy sheet, which is a transfer material. More specifically, in order to eliminate the adverse effect on the image due to the toner in the developing solution being fixed in the wet image forming apparatus, The present invention relates to a wet image forming apparatus having a mechanism for circulating a liquid carrier in a forming apparatus to prevent toner from sticking.

[0002]

2. Description of the Related Art Conventionally, a latent image formed on a latent image carrier such as a photosensitive drum is developed by using a developing solution in which a toner, which is a visualization particle, is dispersed in a liquid carrier, and the visible particles are developed. Wet image forming apparatuses that transfer an image to a transfer paper are known.

[0003]

However, in the conventional wet image forming apparatus, the residual toner after image formation adheres to, for example, the developing device, the surface of the photosensitive drum, the cleaning blade, the transfer belt, etc. As a result, adverse effects such as streaks on the image formed on the transfer paper occurred. This phenomenon occurs even in an image forming apparatus using a solid toner, but it is particularly remarkable in a wet type image forming apparatus using a developing solution. This is because, even if the liquid developer is a small amount, if it adheres to and remains in the image forming apparatus, the liquid carrier has the property of evaporating the liquid carrier and fixing the toner. The present invention has been made in view of the above points, and it is an object of the present invention to provide a wet image forming apparatus capable of eliminating an adverse effect on a formed image caused by sticking of residual toner generated in the wet image forming apparatus. To provide.

As a prior art having a structure similar to that of the present invention although its purpose is completely different, there is a wet image forming apparatus which forms a multicolor image using a single developing device. In this wet type image forming apparatus, the liquid carrier is set in the developing device before the development of the specific color is completed by the developing device and the developing liquid of the different color is supplied in order to develop the different color in the developing device. The developing device is washed by circulating it. However, the reason why the conventional wet type developing device cleans the developing device is to prevent the deterioration of the image quality caused by the mixing of the developing solutions of different colors, and the purpose is different from the present invention. Further, in this conventional wet-type image forming apparatus, since the liquid carrier is circulated only inside the developing device, the inside of the developing device can be washed, but the toner is fixed to the surface of the photosensitive drum, the cleaning blade, the transfer belt and the like. Cannot be prevented.

[0005]

In order to achieve the above object, a wet image forming apparatus according to the invention of claim 1 uniformly charges a latent image carrier by a charging device during cleaning, and a liquid carrier supply unit. The liquid carrier is supplied to the latent image carrier by supplying the liquid carrier to the developing device. A wet image forming apparatus according to a second aspect of the invention is the wet image forming apparatus according to the first aspect,
The transfer material transporting member is a transporting member that avoids a position where it does not come into contact with the liquid carrier during cleaning.

A wet image forming apparatus according to a third aspect of the present invention is the wet image forming apparatus according to the first aspect, characterized in that the wet image forming apparatus has a blowing unit for blowing air to the latent image carrier. . Furthermore, the wet image forming apparatus according to claim 4 develops each of the latent images formed on the plurality of latent image carriers by using a developing solution in which visualization particles are dispersed in a liquid carrier to form a visible particle image. A wet image forming apparatus for transferring and synthesizing a visible particle image on a transfer belt and transferring the visible particle image on the transfer belt to a transfer material to form a color image. To move each latent image carrier to a position where it does not contact the transfer belt, uniformly charge at least one of the plurality of latent image carriers by the charging device, and supply the liquid carrier from the liquid carrier supply unit to the developing device. The liquid carrier is supplied to the latent image carrier by doing so, and then the latent image carrier to which the liquid carrier is supplied by the latent image carrier moving mechanism is brought into contact with the transfer belt, and the liquid is transferred to the transfer belt using the transfer device. To supply a carrier It is an butterfly.

[0007]

According to the present invention, the liquid carrier is circulated not only inside the developing device but also to the surface of the photosensitive drum, the cleaning blade, the transfer belt, and the like, so that the respective members are washed, so that it is generated in the wet image forming apparatus. It is possible to eliminate the adverse effect on the formed image due to the adhesion of the residual toner.

[0008]

[Examples] Specific examples will be described below.
FIG. 2 shows a wet image forming apparatus according to the first embodiment of the present invention. The wet image forming apparatus to which the first embodiment can be applied includes the one shown in FIG. 1. Therefore, the configuration of the first embodiment and the outline of the image forming apparatus of the image forming operation will be described first with reference to FIG. .

In FIG. 1, the photosensitive drum 1, which is a latent image carrier, is rotationally driven in the direction of arrow a at a constant speed during printing. The outer peripheral surface of the photosensitive drum 1 is uniformly charged by the main charger 2 in the dark, and a light image is irradiated and formed by the exposure laser beam 3 to form an electrostatic latent image. Next, the eraser 4 eliminates charges on the outer peripheral surface of the photosensitive drum 1 outside the image forming area, and thereafter, the electrostatic latent image is visualized in the developing solution while passing through the area facing the liquid developing device 5. Toner particles, which are particles, are attached and visualized. The visualized electrostatic latent image is transferred by a transfer charger 7 onto a transfer sheet 6 which is a transfer material conveyed from a sheet feeding device (not shown). After the transfer material 6 is separated from the photosensitive drum 1, the cleaning blade 8 removes the residual toner. In addition,
The arrangement direction of the cleaning blade 8 may be the trailing direction or the counter direction. After that, the photosensitive drum 1
The surface is prepared for the next copy after the residual potential is removed by the slow-electricity lamp 9.

In the liquid developing device 5, a developing container 51
A developing roller 52 that forms a developing region and a squeeze roller 57 that is a squeeze means for thinning the developing solution adhering to the surface of the latent image carrier are disposed inside the photosensitive member and the drum 1 so as to face each other. There is. The developing roller 52 is rotationally driven in the direction of arrow b, which is the reverse rotation direction of the photosensitive drum 1, by a driving unit such as a motor (not shown). Further, above the developing roller 52, a developing solution supply unit 54 that supplies the developing solution to the developing roller 52 is provided. On the right side of the developing roller in the drawing, a scraper 55 has an end portion thereof
It is provided in contact with the outer peripheral surface of No. 2. The developing solution in which the toner is dispersed in the liquid carrier supplied from the developing solution supply unit 54 is accumulated in the wedge-shaped portion 56 formed by the developing roller 52 and the scraper 55, and the rotation of the developing roller 52 causes the photosensitive drum 1 and the developing unit to develop. The roller 52 is supplied to the opposing developing unit.

Further, as the squeeze roller 57 arranged below the developing roller 52 so as to face the photosensitive drum 1, it is preferable to use a squeeze roller whose surface is anodized. The squeeze roller 57 is driven to rotate in the direction of arrow c, which is the opposite direction to the photoconductor drum 1, by a driving unit such as a motor (not shown), thereby removing the excess carrier liquid on the photoconductor drum 1 after development. A scraper 58, which is a contact member in contact with the squeeze roller 57, is provided on the outer peripheral surface of the squeeze roller 57 on the downstream side in the rotation direction of the squeeze roller 57 in the rotational direction, in order to remove the developer on the surface of the squeeze roller 57. It is provided so that its end is in contact with the top. The scraper 58 is a squeeze roller 57.
Clean the developer on top.

In this embodiment, a transfer corona discharger 7 is used as the transfer charger. The transfer corona discharger 7 generates ions opposite to the toner, and the ions are given from the back surface of the transfer paper 6 on the photosensitive drum 1, so that the transfer paper is charged and adsorbed to the photosensitive drum 1, and at the same time. The toner is transferred to the transfer paper 6 by Coulomb force.

A wet-type image forming apparatus according to the first embodiment of the present application, which is applied to the wet-type image forming apparatus outlined above, will be described with reference to FIG. In FIG. 2, illustration of some members shown in FIG. 1 is omitted for convenience of explanation. First, the configuration of the present invention will be described with a focus on the members that have not been described in the above description of the outline of the apparatus. In FIG. 2, 10 is
A liquid carrier supply port for supplying a liquid carrier to the developing roller 52, which is provided above the developing roller 52. Further, numeral 59 is a liquid carrier or a liquid recovery port for recovering a developing solution in which toner is dispersed in the liquid carrier, which is provided at the bottom of the developing container 51. Reference numeral 12 denotes a liquid recovery pipe for recovering the developer or the liquid carrier, one end of which is in communication with the liquid recovery port 59. Reference numeral 13 is a liquid path switching valve provided at the end of the liquid recovery pipe 12 opposite to the end where the liquid opening 59 is provided. The liquid recovery pipe 12 is branched by a valve at a liquid path switching 13, one of which is the developer tank 1
5 and the other one communicates with the liquid carrier tank 14. A filter 16 for removing toner mixed in the liquid carrier is provided in a portion of the liquid recovery pipe 12 from the liquid path switching valve 13 to the liquid carrier tank 14.
Further, 17 is an air blowing unit, which is provided at a position where the air blowing direction is the surface of the photosensitive drum 1.

Next, the operation of the present invention realized by the above-described structure, that is, the toner cleaning operation for preventing toner sticking will be described. First, similarly to the image forming operation described in the outline of the image forming apparatus, the photosensitive drum 1 is rotated and driven at a constant speed in the direction of the arrow a, and the outer peripheral surface of the photosensitive drum 1 is darkened by the main charger 2. Are uniformly charged. In the developing device 5, the developing roller 52
Is rotationally driven in the direction of arrow b, which is the reverse rotation direction of the photosensitive drum 1, by a driving means such as a motor (not shown).
Here, the developer obtained by dispersing the toner in the liquid carrier is supplied from the developer supply unit 54 at the time of image formation, but the liquid carrier is supplied from the liquid carrier supply unit 10 provided above the developing roller 52 at the time of cleaning. To be done. The liquid carrier is accumulated in the wedge-shaped portion 56 formed by the developing roller 52 and the scraper 55, and is supplied to the portion where the photosensitive drum 1 and the developing roller 52 face each other by the rotation of the developing roller 52.

After the developing roller 52 supplies the liquid carrier to the portion where the photosensitive drum 1 and the developing roller 52 face each other, the scraper 55 is brought into a non-contact state from the developing roller by a scraper drive mechanism (not shown) including a solenoid, a cam and the like. As such, it is preferable to further supply the liquid carrier from the liquid carrier supply unit 10 in this state. If the liquid carrier is supplied without contacting the scraper 55,
This is because the developer accumulated in the wedge-shaped portion 56 can be completely washed off during image formation.

The squeeze roller 57 is rotationally driven in the direction of arrow c, which is the opposite direction to the photosensitive drum 1, by a driving means such as a motor (not shown). The rotation of the squeeze roller 57 removes a part of the liquid carrier on the surface of the photoconductor drum 1 to which the liquid carrier has been supplied, thereby cleaning the surface of the photoconductor 1. Here, the scraper 58 that was in contact with the outer peripheral surface of the squeeze roller 57 at the time of image formation
When cleaning, it is preferable to bring the squeeze roller 58 into a non-contact state with a scraper drive mechanism (not shown) including a solenoid, a cam and the like. If the cleaning is performed in a state where the scraper 58 is not in contact with the scraper 58, it is possible to clean the developer that has accumulated in the wedge-shaped portion formed by the squeeze roller 57 and the scraper 58 during image formation. The liquid carrier that has not been removed from the surface of the photosensitive drum 1 by the squeeze roller 57 is conveyed by the photosensitive drum 1, reaches the cleaning blade 8, and the cleaning blade 8 is washed by the liquid carrier. After that, the surface of the photosensitive drum 1 is destaticized by the gradual discharge lamp 9 to prepare for the next cleaning. The transfer charger 7 does not operate during the cleaning operation. Through the above steps, each member to which the developing solution has adhered is washed away with the developing solution.

The liquid carrier that has been washed flows down from the surface of the photoconductor 1 to the bottom of the developing section 5 because the surface of the photoconductor 1 has been neutralized. The liquid carrier that has flowed down is further collected in the liquid recovery port 59 provided at the bottom of the developing device 5,
It reaches the flow path switching valve 13 via the liquid recovery pipe 12. Since the flow path switching valve selects the flow path to the liquid carrier tank 14 during cleaning, the liquid carrier whose apparatus has been cleaned is finally collected in the liquid carrier tank 14.
A filter 16 for removing the washed toner from the liquid carrier is preferably provided between the flow path switching valve 13 and the liquid carrier tank. If the filter 16 is provided, the liquid carrier is prevented from being contaminated by the toner, so that the subsequent cleaning is efficiently performed.

The transfer material 6 is conveyed to a position where transfer from the photosensitive drum 1 to the transfer material 6 is performed by a not-shown conveying member, but this conveying member does not come into contact with the liquid carrier during the cleaning operation. It is preferable that the configuration avoids the above. With this configuration, the transfer member is not wetted by the liquid carrier, so that the transfer material can be transferred smoothly during the image forming operation after the cleaning operation. further,
If a blowing member 17 for blowing air is provided on the surface of the photoconductor 1, after the supply of the liquid carrier into the developing container 51 is stopped, the functions of the main charger 2 and the dimming lamp 9 are stopped, and the photoconductor drum 1 By blowing air toward the inside of the electrophotographic apparatus using this blower member while the roller 52 and the squeeze roller 57 continue to rotate, it is possible to accelerate the drying of each member after cleaning.

Next, a second embodiment of the present invention will be described. FIG. 3 is a sectional view showing an image forming apparatus using a liquid developing apparatus according to the second embodiment. In FIG. 3, 105
Is a transfer belt, and is provided at a position facing the photoconductor 101, the photoconductor 102, the photoconductor 103, and the photoconductor 104. Around the periphery of each photoconductor, a main charger (not shown), a developing device, a cleaning blade, etc. for forming a toner image on each photoconductor drum are arranged. From the upstream side in the rotational direction of the transfer belt 105, the photosensitive drum 101 forms a black toner image on the photosensitive drum 1.
02 forms a magenta toner image, the photosensitive drum 103 forms a yellow toner image, and the photosensitive drum 104 forms a cyan toner image, so that the entire apparatus is capable of forming a full-color image. Further, each photosensitive drum can be selected by a photosensitive drum moving mechanism (not shown) between a state of contacting the transfer belt 105 and a state of not contacting the transfer belt 105.

A blotter roller 106 is provided at a position where it abuts on the transfer belt 105. Further, the blotter roller 106 is connected to the photosensitive drum 104 via the transfer belt 105 on the opposite side of the surface of the transfer belt 105 where the photosensitive drum 104 abuts. A contact member 107 is provided at a position facing each other. Although the contact member 107 is shown in contact with the transfer belt 105 in FIG. 3, it can be moved by a contact member driving means (not shown) including, for example, a solenoid and a cam. The position where the transfer belt 105 and the photosensitive drum 104 are brought into contact with each other and the position where the transfer belt 105 is not brought into contact with the photosensitive drum 104 are selectable. The image forming apparatus configured as described above temporarily transfers the toner image formed on each photoconductor by using a transfer charger (not shown) with each photoconductor drum in contact with the transfer belt 105. The color image is transferred onto the belt 105 and combined. Thereafter, the synthesized toner image is transferred again to a transfer material such as transfer paper to form a full-color image.

Next, the operation of the image forming apparatus during cleaning will be described. First, by the same operation as that of the first embodiment, each photoconductor drum and the developing device, the cleaning drum, and the like arranged on each photoconductor drum are cleaned. During this operation, the state in which each photoconductor does not contact the transfer belt 105 is selected by the photoconductor drum moving mechanism. After the above cleaning is performed for a predetermined time, the photosensitive drum 104 is brought into contact with the transfer belt 105 by the photosensitive drum moving mechanism. The transfer belt 105 and the photosensitive drum 104 may be brought into contact with each other by moving the contact member 107 from the contact member driving means and selecting a position where the transfer belt 105 and the photosensitive drum 104 are brought into contact with each other. . Further, the photoconductor drum 104 and the transfer belt 105 are rotated in the same direction as during image formation, and the transfer charger for transferring the toner image from the photoconductor drum 104 to the transfer belt 105 is operated, so that the photoconductor drum 104 The liquid carrier is supplied to the developing device provided in.

The supplied liquid carrier is supplied to the opposing portion of the photosensitive drum 104 and the transfer belt via the developing device and the photosensitive drum 104. Further, this liquid carrier adheres to the transfer belt because the transfer charger is operating. The liquid carrier is moved by the rotation of the transfer belt 105 from the facing portion of the transfer belt 105 and the photosensitive drum 104 to the portion where the transfer belt 105 and the blotter roller 106 come into contact with each other, and is removed by the blotter roller. In order to clean the entire transfer belt 105,
At least the entire surface of the transfer belt is supplied with the liquid carrier, and the supplied liquid carrier is used for the blotter roller 10.
The transfer belt 104 is rotated as many times as necessary to be removed by 6.
The above cleaning must be continued while the process is completed. As described above, in the second embodiment, the photosensitive drum 1
Since the transfer charger for transferring the toner image from 04 to the transfer belt 105 is operated during the cleaning operation, the liquid carrier is supplied to the transfer belt, and the liquid carrier is removed by the blotter roller 106, so that the transfer belt is removed. It becomes possible to wash.

[0023]

According to the first aspect of the invention, since the liquid carrier is supplied to the uniformly charged photoconductor drum during the cleaning operation, not only the members in the developing container but also the cleaning blade and the photoconductor. It is also possible to wash away the developer adhering to the surface of the drum, and it is possible to prevent the toner from sticking when the developer is dried. By preventing the toner from sticking, it is possible to form a uniform liquid film on the photosensitive drum, and it is possible to prevent the occurrence of abnormal images such as streaks.

Further, according to the second aspect of the present invention, since the transport member is prevented from coming into contact with the liquid carrier during the cleaning operation, the transport member is not wet by the liquid carrier. Therefore, the transfer material is smoothly transported during the image forming operation after the cleaning operation. Further, according to the invention described in claim 3, since the air blowing member for blowing air is provided on the surface of the photoconductor drum, the air is blown toward the inside of the electrophotographic apparatus by the air blowing member after the cleaning operation is completed, so that after cleaning, It becomes possible to accelerate the drying of each member.

Further, according to the invention of claim 4,
Since the transfer charger for transferring the toner image from the photosensitive drum to the transfer belt is operated during the cleaning operation, the liquid carrier is supplied to the transfer belt, and the transfer belt can also be cleaned by the liquid carrier. .

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a wet image forming apparatus to which a first embodiment of the present invention is applied.

FIG. 2 is a schematic configuration diagram of a wet image forming apparatus according to a first embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a wet image forming apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Photoreceptor Drum 2 Main Charger 3 Exposure Laser Light 4 Eraser 5 Liquid Developing Device 51 Developing Container 52 Developing Roller 54 Developing Solution Supply Section 55 Scraper 56 Wedge Section 57 Squeeze Roller 58 Scraper 59 Liquid Collecting Port 6 Transfer Paper 7 Transfer Corona Release Electric appliance (transfer charger) 8 Cleaning blade 9 Elimination lamp 10 Liquid carrier supply unit 12 Liquid recovery pipe 13 Flow path switching valve 14 Liquid carrier tank 15 Developer tank 16 Filter 17 Blower member 101 Photoconductor drum (black) 102 Photoconductor drum ( Magenta) 103 photoconductor drum (yellow) 104 photoconductor drum (cyan) 105 transfer belt 106 blotter roller 107 contact member

Claims (4)

[Claims] 1. A latent image formed on a latent image carrier is developed into a visible particle image by using a developing solution in which visualization particles are dispersed in a liquid carrier, and the visible particle image is transferred to a transfer material. A wet image forming apparatus for forming an image by a charging device that uniformly charges a latent image carrier, and a developer is supplied to the uniformly charged latent image carrier at the time of image formation to wash the latent image carrier. Sometimes a developing device that supplies a liquid carrier to the uniformly charged latent image carrier, a liquid carrier supply unit that supplies the liquid carrier to the developing device, and a visible particle image formed on the latent image carrier. At a position where the transfer material is transferred to the transfer material, and a transfer member which guides the transfer material, and uniformly charges the latent image carrier by the charging device at the time of cleaning. By supplying a liquid carrier to the developing device, Wet image forming apparatus according to claim supplying liquid carrier to the body. 2. The wet type image forming apparatus according to claim 1, wherein the conveying member is a conveying member that avoids a position where the conveying member does not come into contact with a liquid carrier during an apparatus cleaning operation. 3. The wet image forming apparatus according to claim 1, further comprising a blowing unit that blows air to the latent image carrier. 4. A latent image formed on a plurality of latent image carriers is developed with a developing solution in which visualization particles are dispersed in a liquid carrier to form a visible particle image, and the visible image is formed on a transfer belt. A wet image forming apparatus for transferring and synthesizing a particle image, and transferring a visible particle image on the transfer belt to a transfer material to form a color image, wherein a plurality of latent image carriers are uniformly charged. A charging device, and at least one developing device that supplies a developing solution to the uniformly charged latent image carrier during image formation and supplies a liquid carrier to the uniformly charged latent image carrier during cleaning. A liquid carrier supply unit for supplying a liquid carrier to the developing device, a transfer device for transferring a visible particle image from the latent image carrier to the transfer belt, and a blotter roller provided in a position in contact with the transfer belt. ,
Latent image carrier movement for moving the contact member provided at a position facing the photoconductor drum via the transfer belt and the latent image carrier to a position not contacting the transfer belt and a position not contacting the transfer belt. And a latent image carrier moving mechanism that moves each latent image carrier to a position where it does not contact the transfer belt, and at least one of the plurality of latent image carriers is charged by the charging device. Are uniformly charged, and the liquid carrier is supplied from the liquid carrier supply unit to the developing device to supply the liquid carrier to the latent image carrier, and then the latent image carrier moving mechanism supplies the liquid carrier. The wet image forming apparatus characterized in that the latent image carrier thus formed is brought into contact with the transfer belt, and a liquid carrier is supplied to the transfer belt by using the transfer device.