JP2010122405A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which can easily remove charged products adhering to a photoreceptor and is suitable to a liquid developing system. <P>SOLUTION: The image forming apparatus 1 is configured to charge the surface of the photoreceptor 10, supply a liquid developer containing toner and carrier liquid in a mixed state from a developing unit 14 to the surface of the photoreceptor 10 and develop an electrostatic latent image. The image forming apparatus includes a moisture-containing removing roller 512 that can abut on the surface of the photoreceptor 10, the removing roller 512 removes the charge products adhering to the surface of the photoreceptor 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus provided with a liquid developing device used for a copying machine, a printer, a facsimile, a composite machine using the electrophotographic method, and the like.

  In an image forming apparatus using an electrophotographic system, the surface of the photoreceptor is uniformly charged, and an electrostatic latent image is formed on the charged photoreceptor surface by irradiation with laser light based on document information. The electrostatic latent image is developed to form a toner image, and the toner image is transferred to a sheet. Then, the toner image is fixed on the sheet by heating and pressurizing the fixing roller, whereby image formation is performed. Further, after the transfer of the toner image, the surface of the photoreceptor is cleaned by a cleaning blade or the like to remove the remaining toner, and the next image forming cycle is performed. In the image formation as described above, ozone is generated by discharge when charging the surface of the photosensitive member, and moisture in the air is decomposed by the ozone to generate charged products such as nitrogen oxides and ammonium salts. It is known. Since this charged product is water-soluble, when it adheres to the surface of the photoreceptor, it takes in moisture in the atmosphere and lowers the electrical resistance of the surface of the photoreceptor. As a result, when an image is formed, an image flow of the electrostatic latent image formed on the surface of the photoconductor occurs. In addition, amorphous silicon having high durability may be used as the photosensitive member. However, the amorphous silicon photosensitive member has particularly high hygroscopicity compared to other photosensitive members such as an organic photosensitive member. However, there is a drawback that the image flow is remarkable.

  Therefore, in Patent Document 1, when image formation is not performed, a developing bias voltage is applied between the developing device and the photosensitive member, and toner containing an abrasive is supplied from the developing device to the photosensitive member. Adhere to the surface of the photoreceptor. The rotating photoconductor is rubbed against the polishing roller to polish the surface of the photoconductor, and the charged product adhering to the surface of the photoconductor is removed by this polishing.

However, in the development method using a liquid developer obtained by mixing the toner and the carrier liquid using the above-described conventional technology, it is necessary to use a developer peculiar to the liquid development method, and the above-mentioned conventional abrasive is contained. It is difficult to use toner.
JP 2004-279902 A (paragraphs [0030], [0031], [0034], FIG. 1)

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus suitable for a liquid developing system that easily removes a charged product adhering to a photoreceptor. To do.

  In order to achieve the above object, the present invention provides an image forming apparatus for developing an electrostatic latent image by charging a surface of a photoreceptor and supplying a liquid developer obtained by mixing a toner and a carrier liquid to the photoreceptor surface from a developing unit. In the above, a removing member capable of contacting the surface of the photoconductor and containing moisture is provided, and the removing member removes a charged product adhering to the surface of the photoconductor.

  According to this configuration, the charged product adhering to the surface of the photoreceptor is dissolved by the moisture contained in the removal member, and is removed from the surface of the photoreceptor by the removal member.

  According to a second aspect of the present invention, there is provided a water removal member that removes water adhering to the surface of the photoconductor, and the water removal member is disposed downstream of the removal member in the photoconductor rotation direction. It is a feature. According to this configuration, after the charged product is removed from the surface of the photoreceptor by the removing member, the water adhering to the surface of the photoreceptor is removed by the water removing member.

  According to a third aspect of the present invention, an adjustment member that adjusts the amount of water supplied to the removal member is provided. According to this configuration, the adjusting member adjusts the moisture content of the removing member so that moisture does not remain on the surface of the photoreceptor.

  According to a fourth aspect of the present invention, the removing member is a roller, and has a heat source inside the roller. According to this configuration, the heat source evaporates water remaining on the surface of the photoreceptor.

  The invention according to claim 5 is characterized in that a heat source is disposed inside the photoconductor. According to this configuration, moisture remaining on the surface of the photoreceptor is evaporated by the heat source.

  The invention described in claim 6 is characterized in that a heat source is disposed in the vicinity of the outer periphery of the photosensitive member. According to this configuration, moisture remaining on the surface of the photoreceptor is evaporated by the heat source.

  According to the first aspect of the present invention, the charged product adhering to the surface of the photoconductor is dissolved by the moisture contained in the removal member and removed from the surface of the photoconductor by the removal member. The charged product can be easily removed and the image flow can be suppressed, which makes it suitable for the liquid development system.

  According to the second aspect of the present invention, after the charged product is removed from the surface of the photoreceptor by the removing member, the water adhering to the surface of the photoreceptor is removed by the water removing member. The charging characteristics of the photoreceptor can be stabilized.

  According to the third aspect of the present invention, since the adjusting member adjusts the amount of moisture in the removing member so that moisture does not remain on the surface of the photosensitive member, the charging characteristics of the photosensitive member during image formation can be stabilized. Can do.

  According to the fourth aspect of the present invention, since the heat source evaporates moisture remaining on the surface of the photoconductor, the charging characteristics of the photoconductor during image formation can be stabilized.

  According to the fifth aspect of the present invention, moisture remaining on the surface of the photoconductor is evaporated by the heat source, so that the charging characteristics of the photoconductor during image formation can be stabilized.

  According to the sixth aspect of the present invention, moisture remaining on the surface of the photoconductor is evaporated by the heat source, so that the charging characteristics of the photoconductor during image formation can be stabilized.

  Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments. The embodiment of the present invention shows the most preferable form of the invention, and the use of the invention and the terms shown here are not limited thereto.

(First embodiment)
The image forming apparatus according to the first embodiment will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of a tandem type color printer showing an embodiment of an image forming apparatus according to the present invention. FIG. 2 is a schematic cross-sectional view of the image forming apparatus excluding the liquid developer circulating portion, and FIG. 3 is an enlarged cross-sectional view of one of the image forming portions.

  As shown in FIG. 1, an image forming apparatus 1 includes an upper main body 1A that houses various units and parts for image formation, and a liquid developer for each color that is disposed below the upper main body 1A. It is comprised from the lower part main part 1B in which the circulation parts LY, LM, LC, and LB are accommodated. Here, the piping connecting the upper main body 1A and the lower main body 1B is not shown.

  The upper main body 1A includes a paper storage unit 3 for storing paper, a tandem image forming unit 2 for forming a toner image based on image data, and a toner image formed by the image forming unit 2 on the paper. A secondary transfer unit 4 for transferring, a fixing unit 5 for fixing the transferred toner image on the paper, a paper discharge unit 6 for discharging the fixed paper, and from the paper storage unit 3 to the paper discharge unit 6 A paper transport unit 7 for transporting paper is included.

  As shown in FIG. 2, the image forming unit 2 includes an intermediate transfer belt 21, a belt cleaning unit 22 of the intermediate transfer belt 21, and yellow (Y), magenta (M), cyan (C), and black (Bk). Image forming units FY, FM, FC, and FB corresponding to the respective colors are provided.

  The intermediate transfer belt 21 is a belt-like member having an endless shape, that is, a loop shape, which is wider than a sheet having the maximum length in the direction perpendicular to the usable sheet conveying direction and having conductivity. 2 is driven to circulate clockwise. In the circulation driving of the intermediate transfer belt 21, the surface facing outward is hereinafter referred to as a front surface, and the other surface is referred to as a back surface.

  Four image forming units FY, FM, FC, and FB are arranged in the vicinity of the intermediate transfer belt 21 between the belt cleaning unit 22 and the secondary transfer unit 4 of the intermediate transfer belt 21. Note that the order of arrangement of the image forming units FY, FM, FC, and FB is not limited to this, but this arrangement is preferable in consideration of the influence of the color mixture on the completed image.

  The image forming units FY, FM, FC, and FB include a photosensitive member 10, a charger 11, an exposure device 12, a developing device 14, a primary transfer roller 20, a cleaning unit 26, a charge removal device 13, and a carrier. A liquid removal roller 30. Further, among the image forming units, the image forming unit FB located closest to the secondary transfer unit 4 is not provided with the carrier liquid removal roller 30, but the other configurations are the same.

  Corresponding to the image forming units FY, FM, FC, and FB, liquid developer circulating portions LY, LM, LC, and LB (see FIG. 1) are provided, respectively, for supplying and collecting the liquid developers of the respective colors. To be done.

  The photosensitive member 10 is a cylindrical member, and amorphous silicon is used as a photosensitive material for forming a photosensitive layer. The photoconductor 10 may be an organic photoconductor (OPC photoconductor). A toner image containing toner charged on the surface (charged positively in this embodiment) can be carried. The photoreceptor 10 is a member that can rotate counterclockwise in FIG.

  As shown in FIG. 3, around the photoconductor 10, a charger 11, an exposure device 12, a developing device 14, a primary transfer roller 20, a cleaning unit 26, and a photoconductor cleaning described later are arranged in the rotation direction of the photoconductor 10. A part 51 is provided.

  The charger 11 can uniformly charge the surface of the photoconductor 10. The exposure device 12 has a light source such as an LED, and irradiates light onto the uniformly charged surface of the photoconductor 10 in accordance with image data input from an external device. As a result, an electrostatic latent image is formed on the surface of the photoreceptor 10.

  The developing device 14 holds the liquid developer containing the toner and the liquid carrier so as to face the electrostatic latent image on the surface of the photoreceptor 10, thereby attaching the toner to the electrostatic latent image. Thereby, the electrostatic latent image is developed as a toner image.

  The developing device 14 includes a developing container 140, a developing roller 141, a supply roller 142, a support roller 143, a supply roller blade 144, a development cleaning blade 145, and a development roller charger 147. The developing device 14 is rotatably held by a rotating shaft 148 below the developing device 14 and is in a position in contact with the photoconductor 10 during image formation. However, in the photoconductor cleaning mode described later, the developing device 14 is separated from the photoconductor 10. Rotate to.

  The developing container 140 is a container that receives a liquid developer including toner particles and a liquid carrier. The liquid developer is supplied from the liquid developer circulation section into the developing container 140 in a state where the density adjustment between the toner and the carrier is performed in advance.

  The support roller 143 contacts the supply roller 142 to form a nip portion. The supply roller 142 is provided with a groove for holding the liquid developer on the peripheral surface thereof, and rotates in the reverse direction of the supply roller 142.

  The liquid developer supplied from the liquid developer circulation unit is temporarily retained in the developing container 140 and is held in the groove of the supply roller 142 as the support roller 143 and the supply roller 142 rotate. It is carried upward in the state. The supply roller blade 144 is in pressure contact with the peripheral surface of the supply roller 142 and regulates the amount of liquid developer held by the supply roller 142 to be a predetermined amount. Excess liquid developer scraped off by the supply roller blade 144 is received at the bottom of the developing container 140.

  The developing roller 141 is disposed in the upper opening of the developing container 140 so as to be in contact with the supply roller 142. The developing roller 141 is rotated in the same direction as the supply roller 142, whereby the liquid developer held on the peripheral surface of the supply roller 142 is transferred to the peripheral surface of the developing roller 141. Since the layer thickness of the liquid developer on the supply roller 142 is regulated to a predetermined value, the layer thickness of the liquid developer layer formed on the surface of the developing roller 141 is also maintained at a predetermined value.

  Further, the developing roller 141 is in contact with the photosensitive member 10, and a toner image corresponding to image data is transferred to the photosensitive member 10 by a potential difference between the electrostatic latent image potential on the surface of the photosensitive member 10 and the developing bias applied to the developing roller 141. Formed on the surface.

  The developing roller charger 147 moves the toner in the developer layer carried on the developing roller 141 to the surface side of the developing roller 141 by applying a charging potential having the same polarity as the charging polarity of the toner, thereby improving the developing efficiency. Let

  The developing cleaning blade 145 is arranged so as to contact the downstream side in the rotation direction of the contact portion of the developing roller 141 with the photosensitive member 10, and removes the liquid developer on the surface of the developing roller 141 that has completed the developing operation on the photosensitive member 10. Remove.

  The primary transfer roller 20 is disposed on the back surface of the intermediate transfer belt 21 so as to face the photoreceptor 10. A voltage having a polarity opposite to that of the toner in the toner image (minus in this embodiment) is applied to the primary transfer roller 20 from a power source (not shown). That is, the primary transfer roller 20 applies a voltage having a polarity opposite to that of the toner to the intermediate transfer belt 21 at a position in contact with the intermediate transfer belt 21. Since the intermediate transfer belt 21 has conductivity, the applied voltage attracts toner to the surface side of the intermediate transfer belt 21 and its periphery.

  The cleaning unit 26 is for cleaning the liquid developer remaining on the photoreceptor 10 and includes a cleaning blade 262. The cleaning blade 262 is a plate-like member that slidably contacts the surface of the photoconductor 10 and scrapes off the liquid developer remaining on the surface of the photoconductor 10 as the photoconductor 10 rotates. The liquid developer scraped off by the cleaning blade 262 is temporarily stored in the cleaning unit 26 and then conveyed to the outside of the cleaning unit 26.

  Ozone is generated when the surface of the photoconductor 10 is charged, and a charged product is generated by this ozone. The photoconductor cleaning unit 51 removes the charged product adhering to the surface of the photoconductor 10 from the surface of the photoconductor 10. To do. The photosensitive member cleaning unit 51 is rotatably held by a rotating shaft 511 below the photosensitive member cleaning unit 51. The photosensitive member cleaning unit 51 is separated from the photosensitive member 10 at the time of image formation. Rotate to touching position.

  Returning to FIG. 2, the paper storage unit 3 is a part for storing a paper for fixing a toner image, and is disposed at the lower part of the upper main body 1 </ b> A. The paper storage unit 3 has a paper feed cassette that stores paper. The secondary transfer unit 4 is a part that transfers the toner image formed on the intermediate transfer belt 21 to a sheet, and is disposed opposite to the support roller 41 that supports the intermediate transfer belt 21 and the support roller 41. And a secondary transfer roller 42.

  The belt cleaning unit 22 is for cleaning the carrier liquid remaining on the intermediate transfer belt 21 after the toner image is transferred to the paper. The belt developer is scraped off by a cleaning blade, Transport to the liquid developer circulation section.

  The fixing unit 5 is a part for fixing the toner image on the sheet, and is disposed on the upper side of the secondary transfer unit 4. The fixing unit 5 includes a heating roller and a pressure roller disposed so as to face the heating roller. The paper discharge unit 6 is a portion from which the paper on which the toner image has been fixed by the fixing unit 5 is discharged, and is disposed at the top of the image forming apparatus 1. The paper transport unit 7 includes a plurality of transport roller pairs, and transports the paper from the paper storage unit 3 to the secondary transfer unit 4, the fixing unit 5, and the paper discharge unit 6.

  Next, the photoconductor cleaning mode will be described. FIG. 4 is a cross-sectional view showing the image forming unit in the photoreceptor cleaning mode. In the photosensitive member cleaning mode, the developing device 14 and the cleaning unit 26 are separated from the photosensitive member 10.

  The photoconductor cleaning unit 51 is disposed downstream of the cleaning unit 26 in the rotation direction of the photoconductor 10 and upstream of the charger 11 in the rotation direction of the photoconductor 10. Further, the photosensitive member cleaning unit 51 rotates a water container 518 that stores water W, a water supply roller 513, a removing roller 512 that is a removing member, a water removing member 514, and a main body 517 of the photosensitive member cleaning unit 51. And a rotating shaft 511 that is freely held.

  The water supply roller 513 has an axial length substantially the same as that of the cylindrical photosensitive member 10 and is formed of a urethane resin foam. A part of the water supply roller 513 is immersed in the water W in the water container 518. ing.

  The removal roller 512 is made of a cylindrical nonwoven fabric and has an axial length substantially the same as that of the photoconductor 10. The removal roller 512 is in contact with the water supply roller 513 on one side and contacts the surface of the photoconductor 10 on the other side. Touching. When the photoconductor 10 rotates, the removal roller 512 follows and rotates, and the water supply roller 513 rotates following the rotation. As a result, the water W in the water container 518 passes through the water supply roller 513 to the removal roller 512. Sucked up. The sucked water W melts the charged product adhering to the surface of the photoconductor 10 at the contact portion between the removal roller 512 and the surface of the photoconductor 10, and the removal roller 512 removes the charged product from the surface of the photoconductor 10. The removal roller 512 may be a urethane resin foam.

  The water removal member 514 has a plate shape and has an axial length substantially the same as that of the removal roller 512. The water removal member 514 is disposed downstream of the removal roller 512 in the photosensitive member rotation direction, and is attached to the main body 517 at one end thereof. The other end is in contact with the surface of the photoreceptor 10. The water removing member 514 scrapes off the water W adhering to the surface of the photoconductor 10 as the photoconductor 10 rotates.

  When the cleaning of the photoconductor 10 is completed, the photoconductor cleaning unit 51 is separated from the surface of the photoconductor 10, and the developing device 14 and the cleaning unit 26 come into contact with the surface of the photoconductor 10 to enable image formation.

  According to the first embodiment, the image forming apparatus 1 charges the surface of the photoconductor 10 and supplies a liquid developer, which is a mixture of toner and carrier liquid, from the developing device 14 to the surface of the photoconductor 10. Develop. A removal roller 512 that can be brought into contact with the surface of the photoconductor 10 and contains water is provided. The removal roller 512 removes the charged product attached to the surface of the photoconductor 10.

  According to this configuration, the charged product adhering to the surface of the photoconductor 10 is dissolved by the moisture contained in the removal roller 512 and is removed from the surface of the photoconductor 10 by the removal roller 512. The product can be easily removed and the image flow can be suppressed, which is suitable for the liquid development system.

  Further, according to the first embodiment, the water removing member 514 that removes the moisture adhering to the surface of the photoconductor 10 is provided, and the water removing member 514 is disposed downstream of the removing roller 512 in the photoconductor rotation direction. Thus, after the charged product is removed from the surface of the photoconductor 10 by the removing roller 512, the water adhering to the surface of the photoconductor 10 is removed by the water removing member 514, so that the charging characteristics of the photoconductor 10 at the time of image formation can be improved. It can be stabilized.

(Second Embodiment)
FIG. 5 is a cross-sectional view showing the image forming unit in the photoconductor cleaning mode according to the second embodiment of the present invention. The photosensitive member cleaning unit, which is different from the first embodiment, will be mainly described. In the photosensitive member cleaning mode, the developing device 14 and the cleaning unit 26 are separated from the photosensitive member 10.

  The photoconductor cleaning unit 61 is disposed downstream of the cleaning unit 26 in the rotation direction of the photoconductor 10 and upstream of the charger 11 in the rotation direction of the photoconductor 10. The photoreceptor cleaning unit 61 includes a tank 614 for storing water, a pipe 616, a pump 615 as an adjustment member, a removal roller 612 as a removal member, and a heater 613 as a heat source.

  The pump 615 is provided in the middle of a pipe 616 extending from the tank 614 to the removal roller 612, and adjusts the amount of water supplied from the tank 614 to the removal roller 612.

  The removal roller 612 is made of a cylindrical nonwoven fabric, has an axial length substantially equal to that of the photoconductor 10, and is in contact with the surface of the photoconductor 10. When the photosensitive member 10 rotates, the removing roller 612 follows and rotates, and water absorbed by the removing roller 612 at the contact portion between the removing roller 612 and the surface of the photosensitive member 10 is attached to the surface of the photosensitive member 10 to generate a charge. The removal roller 612 removes the charged product from the surface of the photoreceptor 10 by melting the object. The removal roller 612 may be a foamed urethane resin.

  A heater 613 is disposed inside the removal roller 612. When the charged product is removed from the surface of the photoconductor 10, the heater 613 is then turned on, and the water remaining on the surface of the photoconductor 10 is evaporated by the heat of the heater 613.

  When the cleaning of the photoconductor 10 is completed, the photoconductor cleaning unit 61 is separated from the surface of the photoconductor 10, and the developing device 14 and the cleaning unit 26 come into contact with the surface of the photoconductor 10, thereby enabling image formation.

  According to the second embodiment, the image forming apparatus 1 charges the surface of the photoconductor 10 and supplies a liquid developer, which is a mixture of toner and carrier liquid, from the developing device 14 to the surface of the photoconductor 10. Develop. A removal roller 612 that can contact the surface of the photoconductor 10 and contains water, a pipe 616 that supplies water to the removal roller 612, and a pump 615 that adjusts the amount of water supplied to the removal roller 612 are provided. 612 removes the charged product adhering to the surface of the photoreceptor 10.

  According to this configuration, the pump 615 adjusts the amount of water in the removal roller 612, and the removal roller 612 melts the charged product adhering to the surface of the photoconductor 10 with the contained moisture, and removes the charged product from the surface of the photoconductor 10. Since it is removed, the charged product adhering to the surface of the photoconductor 10 can be easily removed, the image flow can be suppressed, and it is suitable for the liquid developing system.

  Further, according to the second embodiment, the heater 613 is disposed inside the removing roller 612, so that the heater 613 evaporates water remaining on the surface of the photoconductor 10, so that the charging characteristics of the photoconductor during image formation are set. Can be stabilized.

(Third embodiment)
FIG. 6 is a cross-sectional view showing the image forming unit in the photoconductor cleaning mode according to the third embodiment of the present invention. A heat source different from the second embodiment will be mainly described. In the photosensitive member cleaning mode, the developing device 14 and the cleaning unit 26 are separated from the photosensitive member 10.

  The photoconductor cleaning unit 71 is disposed downstream of the cleaning unit 26 in the rotation direction of the photoconductor 10 and upstream of the charger 11 in the rotation direction of the photoconductor 10. The photoreceptor cleaning unit 71 includes a tank 714 for storing water, a pipe 716, a pump 715 as an adjustment member, a removal roller 712 as a removal member, and a heater 713 as a heat source.

  The pump 715 is provided in the middle of a pipe 716 extending from the tank 714 to the removal roller 712, and adjusts the amount of water supplied from the tank 714 to the removal roller 712.

  The removal roller 712 is made of a cylindrical nonwoven fabric, has an axial length substantially equal to that of the photoconductor 10, and is in contact with the surface of the photoconductor 10. When the photosensitive member 10 rotates, the removal roller 712 follows and rotates, and water absorbed by the removal roller 712 at the contact portion between the removal roller 712 and the surface of the photosensitive member 10 generates charge that adheres to the surface of the photosensitive member 10. The removal roller 712 removes the charged product from the surface of the photoconductor 10. The removal roller 712 may be a foamed urethane resin.

  A heater 713 is disposed inside the photoconductor 10, and the heater 713 evaporates water remaining on the surface of the photoconductor 10 by the heat. When the charged product is removed from the surface of the photoconductor 10, the heater 713 may be turned on thereafter.

  When the cleaning of the photoconductor 10 is completed, the photoconductor cleaning unit 71 is separated from the surface of the photoconductor 10, and the developing device 14 and the cleaning unit 26 come into contact with the surface of the photoconductor 10, thereby enabling image formation.

  According to the third embodiment, the image forming apparatus 1 charges the surface of the photoconductor 10 and supplies a liquid developer, which is a mixture of toner and carrier liquid, from the developing device 14 to the surface of the photoconductor 10. Develop. A removal roller 712 that can contact the surface of the photoconductor 10 and contains water, a pipe 716 that supplies water to the removal roller 712, a pump 715 that adjusts the amount of water supplied to the removal roller 712, and a removal roller 712. The removal roller 712 removes the charged product adhering to the surface of the photoconductor 10.

  According to this configuration, the pump 715 adjusts the moisture content of the removal roller 712, and the removal roller 712 melts the charged product adhering to the surface of the photoconductor 10 with the contained moisture and removes it from the surface of the photoconductor 10. It is possible to easily remove the charged product adhering to the surface of the photoreceptor 10 and suppress the image flow. In addition, since the heater 713 evaporates water remaining on the surface of the photoconductor 10, the charging characteristics of the photoconductor during image formation can be stabilized, and is suitable for the liquid developing system.

(Fourth embodiment)
FIG. 7 is a cross-sectional view showing the image forming unit in the photoconductor cleaning mode according to the fourth embodiment of the present invention. A heat source different from the second and third embodiments will be mainly described. In the photosensitive member cleaning mode, the developing device 14 and the cleaning unit 26 are separated from the photosensitive member 10.

  The photoreceptor cleaning unit 81 is disposed downstream of the cleaning unit 26 in the rotation direction of the photoreceptor 10. The photoreceptor cleaning unit 81 includes a tank 814 that stores water, a pipe 816, a pump 815 that is an adjustment member, a removal roller 812 that is a removal member, and a heater 813 that is a heat source.

  The pump 815 is provided in the middle of a pipe 816 extending from the tank 814 to the removal roller 812, and adjusts the amount of water supplied from the tank 814 to the removal roller 812.

  The removal roller 812 is made of a cylindrical nonwoven fabric, has an axial length substantially equal to that of the photoconductor 10, and is in contact with the surface of the photoconductor 10. When the photoconductor 10 rotates, the removal roller 812 follows and rotates, and the water absorbed by the removal roller 812 at the contact portion between the removal roller 812 and the surface of the photoconductor 10 generates charge that adheres to the surface of the photoconductor 10. The removal roller 812 removes the charged product from the surface of the photoreceptor 10 by melting the object. The removal roller 812 may be a foam of urethane resin.

  A heater 813 is disposed in the vicinity of the outer periphery of the photoconductor 10 and downstream of the removing roller 812 in the rotation direction of the photoconductor 10, and the heater 813 evaporates water remaining on the surface of the photoconductor 10 by the heat. When the charged product is removed from the surface of the photoconductor 10, the heater 813 may be turned on thereafter.

  When the cleaning of the photoconductor 10 is completed, the photoconductor cleaning unit 81 is separated from the surface of the photoconductor 10, and the developing device 14 and the cleaning unit 26 come into contact with the surface of the photoconductor 10, thereby enabling image formation.

  According to the fourth embodiment, the image forming apparatus 1 charges the surface of the photoconductor 10 and supplies a liquid developer, which is a mixture of toner and carrier liquid, from the developing device 14 to the surface of the photoconductor 10. Develop. A removal roller 812 that can contact the surface of the photoconductor 10 and contains water, a pipe 816 that supplies water to the removal roller 812, a pump 815 that adjusts the amount of water supplied to the removal roller 812, and an outer periphery of the photoconductor 10. The removal roller 812 removes the charged product adhering to the surface of the photoconductor 10.

  According to this configuration, the pump 815 adjusts the amount of water in the removal roller 812, and the removal roller 812 melts the charged product adhering to the surface of the photoconductor 10 with the contained water and removes it from the surface of the photoconductor 10. It is possible to easily remove the charged product adhering to the surface of the photoreceptor 10 and suppress the image flow. Further, since the heater 813 evaporates water remaining on the surface of the photoconductor 10, the charging characteristics of the photoconductor during image formation can be stabilized, and the heater 813 is suitable for the liquid developing system.

  In the above-described embodiment, the removal member is configured by a cylindrical roller. However, the present invention is not limited to this, and the removal member is a plate-like blade made of a nonwoven fabric material or a foamed urethane resin. The blade may be configured to be supplied with water from a water container or a tank and rub against the surface of the photoreceptor. In this case, the same effect as described above can be obtained.

  The present invention can be used for an image forming apparatus provided with a liquid developing unit used in a copying machine, a printer, a facsimile, a composite machine using the electrophotographic method, and the like.

1 is a schematic cross-sectional view showing an overall configuration of an image forming apparatus according to a first embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of the image forming apparatus excluding a portion of the liquid developer circulating unit according to the first embodiment of the present invention. These are sectional drawings which expand and show one of the image forming parts concerning a 1st embodiment of the present invention. These are sectional views showing the image forming unit in the photoconductor cleaning mode according to the first embodiment of the present invention. These are sectional drawings which show the image formation part in the photoconductor cleaning mode which concerns on 2nd Embodiment of this invention. These are sectional drawings which show the image formation part in the photoconductor cleaning mode which concerns on 3rd Embodiment of this invention. These are sectional drawings which show the image formation part in the photoreceptor cleaning mode which concerns on 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Color printer 2 Image formation part 10 Photoconductor 11 Charger 14 Developing device 26 Cleaning part 51, 61, 71, 81 Photoconductor cleaning part 148,511 Rotating shaft 512,612,712,812 Removal roller (removal member)
513 Water supply roller 514 Water removal member 518 Water container 613, 713, 813 Heater (heat source)
614, 714, 814 Tank 615, 715, 815 Pump 616, 716, 816 Pipe W Water

Claims (6)

In an image forming apparatus for developing an electrostatic latent image by charging a surface of a photoreceptor and supplying a liquid developer obtained by mixing a toner and a carrier liquid from the developing unit to the surface of the photoreceptor.
An image forming apparatus comprising: a removing member capable of contacting the surface of the photosensitive member and containing moisture, wherein the removing member removes a charged product adhering to the surface of the photosensitive member.   The image forming apparatus according to claim 1, further comprising a water removing member that removes moisture adhering to the surface of the photoconductor, wherein the water removing member is disposed downstream of the removing member in the photoconductor rotation direction. apparatus.   The image forming apparatus according to claim 1, further comprising an adjustment member that adjusts an amount of moisture supplied to the removal member.   The image forming apparatus according to claim 1, wherein the removing member includes a roller and has a heat source inside the roller.   The image forming apparatus according to claim 1, wherein a heat source is disposed inside the photoconductor.   The image forming apparatus according to claim 1, wherein a heat source is disposed in the vicinity of the outer periphery of the photoconductor.

Images