Patent Publication Number: US-9841696-B2

Title: Image forming apparatus and cleaning method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2016-043403 filed Mar. 7, 2016. 
     BACKGROUND 
     Technical Field 
     The present invention relates to an image forming apparatus and a cleaning method. 
     SUMMARY 
     According to an aspect of the invention, there is provided an image forming apparatus including: 
     a first holding member that is rotated and holds a liquid developer including a volatile carrier liquid; 
     a first cleaning member that is able to come into contact with or separated from the first holding member and cleans a surface of the first holding member by being in contact with the first holding member; 
     a supplying device that supplies a volatile washing liquid to the first holding member at an upstream side of the first cleaning member in a rotation direction of the first holding member; and 
     a switching mechanism that switches a first state in which the washing liquid is supplied to the first holding member in a state in which the first cleaning member is in contact with the first holding member that is rotated to a second state in which the first cleaning member is separated from the first holding member that is rotated and the washing liquid is applied to the first holding member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the present invention will be described in detail based on the following figures, wherein: 
         FIG. 1  is a configuration view illustrating an image forming apparatus according to a first exemplary embodiment of the invention; 
         FIG. 2  is a configuration view illustrating a state in which a contact portion of a developing roll and a scraping blade used for the image forming apparatus illustrated in  FIG. 1  is washed; 
         FIG. 3  is a view illustrating a state in which the scraping blade is separated from the developing roll used for the image forming apparatus illustrated in  FIG. 1  and washing liquid is applied to the developing roll; 
         FIG. 4  is a configuration view illustrating a state in which a contact portion of a transfer roll and a cleaning member used for an image forming apparatus according to a second exemplary embodiment is washed; 
         FIG. 5  is a configuration view illustrating a state in which the cleaning member is separated from the transfer roll used for the image forming apparatus illustrated in  FIG. 4 , the washing liquid is applied to the transfer roll, and a contact portion of the image holding member and the cleaning member is washed; 
         FIG. 6  is a configuration view illustrating a state in which the cleaning member is separated from the image holding member used for the image forming apparatus illustrated in  FIG. 4 , the washing liquid is applied to the image holding member, and a contact portion of the developing roll and the cleaning member is washed; 
         FIG. 7  is a configuration view illustrating a state in which the cleaning member is separated from the developing roll used for the image forming apparatus illustrated in  FIG. 4 , and the washing liquid is applied to the developing roll; and 
         FIG. 8  is a configuration view illustrating a state in which, before forming an image, the washing liquid is applied to the transfer roll, the image holding member, and the developing roll used for the image forming apparatus illustrated in  FIG. 4 , and then the transfer roll, the image holding member, and the developing roll are reversely rotated. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, an exemplary embodiment of the image forming apparatus of the invention will be described with reference to drawings. Also, an arrow H illustrated in each drawing indicates an up and down direction (vertical direction) of the apparatus, and an arrow W indicates a width direction (horizontal direction) of the apparatus. 
     First Exemplary Embodiment 
     Entire Configuration of Image Forming Apparatus 
     In  FIG. 1 , an example of an image forming apparatus  10  of a first exemplary embodiment is illustrated. As illustrated in  FIG. 1 , the image forming apparatus  10  includes a transportation unit  12  which transports continuous form paper P as an example of a recording medium, an image forming section  14  which forms a toner image on the continuous form paper P, and a fixing device  16  which fixes the toner image to the continuous form paper P. 
     The transportation unit  12  has a function of transporting the continuous form paper P in an arrow A direction (transportation direction) at a predetermined transportation speed. Moreover, the transportation unit  12  winds the continuous form paper P, and includes a pair of transport rolls  12 A and  12 B which are disposed side by side in a width direction of the apparatus. The transport roll  12 A is disposed on an upstream side of the transportation direction of the continuous form paper P with respect to the transport roll  12 B. The continuous form paper P is transported from a lower side to an upper side of an up and down direction in the upstream side with respect to the transport roll  12 A, and is transported from the upper side to the lower side of the up and down direction in a downstream side with respect to the transport roll  12 B. 
     The image forming section  14  includes an image forming section  14 Y which forms a toner image of a yellow color (Y), an image forming section  14 M which forms a toner image of a magenta color (M), an image forming section  14 C which forms a toner image of a cyan color (C), and an image forming section  14 K which forms a toner image of a black color (K). In the image forming apparatus  10 , as an example, the image forming sections  14 Y,  14 M,  14 C, and  14 K are disposed in this order from the upstream side in the transportation direction of the continuous form paper P. 
     The image forming sections  14 Y,  14 M,  14 C, and  14 K of each color are disposed inside a housing  17 . In a lower wall of the housing  17 , an opening  17 A where the continuous form paper P transported by the transportation unit  12  is entered into the housing  17  is formed, and in a upper wall of the housing  17 , an opening  17 B, which exits the continuous form paper P entered into the housing  17  to the outside of the housing  17 , is formed. The image forming sections  14 Y,  14 M,  14 C, and  14 K of each color are formed basically in the same manner except a liquid developer G to be used. 
     The image forming sections  14 Y,  14 M,  14 C, and  14 K of each color include, an image forming unit  18  for forming the toner image using the liquid developer G including toner and insulating liquid, and a transfer unit  20  for transferring a toner image formed by the image forming unit  18  to the continuous form paper P. In the exemplary embodiment, the continuous form paper P is transported to the upper side from the lower side in the up and down direction by the transportation unit  12 , and the image forming sections  14 Y,  14 M,  14 C, and  14 K of each color are disposed side by side from the lower side toward the upper side in the up and down direction. 
     The image forming unit  18  includes an image holding member  22  which rotates in an arrow C direction and holds the toner image. Also, the image forming unit  18  includes sequentially a charging device  24  which charges the image holding member  22 , an exposure device  26  which irradiates the image holding member  22  with exposing light and forms an electrostatic latent image, and a developing device  28  which develops the electrostatic latent image on the image holding member  22  as a toner image, from the upstream side of a rotation direction (arrow C direction) of the image holding member  22 . Further, the image forming unit  18  includes a cleaning device  30  which cleans an outer peripheral surface of the image holding member  22 , after the toner image is transferred to a transfer roll  50  to be described later from the image holding member  22 . The cleaning device  30  includes a scraping blade  32  as an example of a cleaning member which scrapes the liquid developer G remaining on the outer peripheral surface of the image holding member  22  without being transferred to the transfer roll  50  from the image holding member  22 , and a recovering member  34  which recovers the scraped liquid developer G. 
     The developing device  28  includes a developing roll  36 , which rotates in an arrow D direction and develops an electrostatic latent image formed on the image holding member  22  using the liquid developer G, as an example of a holding member. In addition, the developing device  28  sequentially includes a supplying device  40 , which supplies the liquid developer G to the developing roll  36 , and a charging device  42 , which charges toners included in the liquid developer G supplied to the developing roll  36 , from the upstream side of a rotation direction (arrow D direction) of the developing roll  36 . Further, the developing device  28  includes a cleaning device  44  which cleans an outer peripheral surface of the developing roll  36  after developing. The cleaning device  44  includes a scraping blade  46 , which scrapes the liquid developer G remaining on the outer peripheral surface of the developing roll  36 , as an example of the cleaning member, and a recovering member  48  which recovers the scraped liquid developer G. 
     The liquid developer G used for the exemplary embodiment is a liquid type developer in which toners (particles) are dispersed in volatile carrier liquid, and as carrier liquid, insulating liquid having volatility which is selected from, for example, vegetable oil, liquid paraffin oil, and silicone oil, is used. In addition, relating to the liquid developer G, as an example, an average particle diameter of the toner is 0.5 μm or more and 5 μm or less, and the toner (particles) in the carrier liquid is dispersed at a concentration of 15 wt % or more and 45 wt % or less. 
     The supplying device  40  includes a container  70  which is disposed on a lower side of the developing roll  36  and accommodates the liquid developer G, and a supplying roll  72  which pumps the liquid developer G from the container  70  and supplies the developer to the outer peripheral surface of the developing roll  36 . The supplying roll  72  is rotated in an arrow E direction, and is moved in the same direction as that of the developing roll  36  at a position in contact with the developing roll  36 . The supplying roll  72  includes plural concave portions (not illustrated) on the outer peripheral surface thereof, and the liquid developer G is held on the concave portions. In addition, the supplying device  40  includes a regulating blade  74  which adjusts a layer film of the liquid developer G attached to the supplying roll  72 , and a charging device  76  which charges toners included in the liquid developer G attached to the supplying roll  72 . 
     In the supplying device  40 , the liquid developer G accommodated in the container  70  is pumped due to rotation of the supplying roll  72 , and the layer film of the liquid developer G attached to the supplying roll  72  is regulated by the regulating blade  74 . Further, the liquid developer G attached to the supplying roll  72  is supplied to the outer peripheral surface of the developing roll  36  by an electrical field formed between the supplying roll  72  and the developing roll  36 . 
     In the developing device  28 , the charging device  42  charges the toner included in the liquid developer G supplied to the outer peripheral surface of the developing roll  36 , and an electrostatic latent image on the image holding member  22  is developed as a toner image by the liquid developer G of the outer peripheral surface of the developing roll  36 . Also, in a case in which the electrostatic latent image is developed as the toner image using the liquid developer G, the carrier liquid is also moved to the image holding member  22 . 
     The transfer unit  20  includes the transfer roll  50 , which is disposed to face the image holding member  22  and rotated in the arrow B direction, on which the toner image on the image holding member  22  is transferred due to an electrical field formed between the image holding member  22  and the roll. In addition, the transfer unit  20  is disposed on an opposite side of the transfer roll  50  with the continuous form paper P pinched therebetween, and includes a backup roll  52  which transfers the toner image on the transfer roll  50  to the continuous form paper P due to the electrical field formed between the unit and the transfer roll  50 . Further, the transfer unit  20  includes a cleaning device  54  which cleans the outer peripheral surface of the transfer roll  50  after transferring. The cleaning device  54  includes a scraping blade  56  which scrapes the liquid developer G remaining on the outer peripheral surface of the transfer roll  50  after transferring, and a recovering member  58  which recovers the scraped liquid developer G. 
     In the transfer unit  20 , the toner image on the image holding member  22  is transferred to the transfer roll  50 , and the toner image transferred to the transfer roll  50  is transferred to the continuous form paper P. In addition, in the same manner, the carrier liquid which is moved from the developing roll  36  to the image holding member  22 , is also moved to the continuous form paper P through the transfer roll  50 . 
     The fixing device  16  includes a heating portion  60  which heats the continuous form paper P, a carrier liquid removing portion  62  which removes the carrier liquid from the continuous form paper P, and a fixing portion  64  which fixes the toner image to the continuous form paper P. The carrier liquid removing portion  62  and the fixing portion  64  include a heating roll  65 , and a pressure roll  66  which presses the continuous form paper P with the heating roll  65 . 
     In the fixing device  16 , the heating portion  60  heats the continuous form paper P, and the toner included in the liquid developer G on the continuous form paper P and the carrier liquid (oil) are dispersed, and therefore, an oil layer is formed on an upper layer of the toner. Further, the carrier liquid removing portion  62  removes the carrier liquid (oil), and the continuous form paper P is heated and pressed, and thus the toner image is fixed to the continuous form paper P by the fixing portion  64 . 
     In the image forming apparatus  10  described above, the image holding member  22  of the image forming unit  18  of each color is rotated, and the charging device  24  charges the outer peripheral surface of the image holding member  22  with electricity. Next, the exposure device  26  exposes the outer peripheral surface of the image holding member  22 , and the electrostatic latent image is formed on the outer peripheral surface of the image holding member  22 . The electrostatic latent image is developed by the developing device  28  as a toner image. Further, the toner image formed on the rotated outer peripheral surface of the image holding member  22  is primarily transferred to the transfer roll  50 . The toner image primarily transferred to the transfer roll  50  is transferred to the continuous form paper P being transported in the arrow A direction. Such a process is carried out in the image forming section  14  of each color, and the toner image in which colors are superimposed is formed on the continuous form paper P. Further, the fixing device  16  removes the carrier liquid (oil) of the transported continuous form paper P, and fixes the toner image to the continuous form paper P. 
     Main Configuration of Image Forming Apparatus 
     Next, an image forming apparatus of a first exemplary embodiment will be described with reference to  FIG. 2  and  FIG. 3 . 
       FIG. 2  illustrates, in a main configuration of the image forming apparatus  10  illustrated in  FIG. 1 , a state in which a contact portion of the developing roll  36  and the scraping blade  46  is washed with the washing liquid L. In addition,  FIG. 3  illustrates, in a main configuration of the image forming apparatus illustrated in  FIG. 1 , a state of applying the washing liquid L to the developing roll  36 . 
     As illustrated in  FIG. 2  and  FIG. 3 , the developing device  28  includes a contact and separation device  80  which allows the scraping blade  46  to be brought into contact with the outer peripheral surface of the developing roll  36  or to separate the scraping blade  46  from the outer peripheral surface of the developing roll  36 . The scraping blade  46  includes a plate-shaped blade portion  46 A which scrapes the liquid developer G remaining on the outer peripheral surface of the developing roll  36  in contact with the developing roll  36 , and a supporting member  46 B supporting the blade portion  46 A. The blade portion  46 A is disposed to be in contact with the developing roll  36  so that a front edge of the blade portion  46 A is toward an upstream side of a rotation direction of the developing roll  36 . The contact and separation device  80  includes, as an example, a hydraulic cylinder. More specifically, the contact and separation device  80  includes a cylinder main body portion  80 A, and a rod  80 B which moves forward and backward with respect to the cylinder main body portion  80 A and an edge portion thereof is fixed to the supporting member  46 B. When the rod  80 B moves forward and backward with respect to the cylinder main body portion  80 A, the scraping blade  46  is moved to a position of being in contact with the outer peripheral surface of the developing roll  36 , and the scraping blade  46  is moved to a position of being separated from the outer peripheral surface of the developing roll  36 . In the image forming apparatus  10  (refer to  FIG. 1 ), a controller  82 , which controls an operation of the contact and separation device  80 , is provided. The controller  82  controls a rotational operation of the developing roll  36 , a rotational operation of the image holding member  22 , and a rotational operation of the transfer roll  50 . The contact and separation device  80  and the controller  82  are an example of a switching mechanism. The controller  82  will be described later. 
     In addition, the developing device  28  includes a supplying device  84  which supplies the washing liquid L to the outer peripheral surface of the developing roll  36 . The supplying device  84  includes, as an example, a supplying roll  86  which is in contact with the developing roll  36  and rotated at the same time and supplies the washing liquid L to the outer peripheral surface of the developing roll  36 , and a nozzle  88  which ejects the washing liquid L to the supplying roll  86 . The supplying device  84  is disposed at an upstream side of the scraping blade  46  in a rotation direction (arrow D direction) of the developing roll  36 . In addition, the supplying device  84  is disposed at the downstream side further than a facing portion with the image holding member  22  (refer to  FIG. 1 ) in a rotation direction (arrow D direction) of the developing roll  36 . In the exemplary embodiment, the developing roll  36  is in contact with the image holding member  22 , and is configured to rotate in the same direction at a contacting position with the image holding member  22  (refer to  FIG. 1 ). 
     The washing liquid L is volatile washing liquid, and as an example, volatile carrier liquid including a two-component developer G is used. Moreover, the washing liquid L is not limited to the volatile carrier liquid, and for example, volatile organic solvent, or the like may be used. 
     The supplying roll  86  has a function of holding the washing liquid L ejected from the nozzle  88  and supplying the liquid to the outer peripheral surface of the developing roll  36 . The supplying roll  86  is supported to be rotatable, and is rotated in the same direction as that of the contact portion of the developing roll  36 . In the exemplary embodiment, the supplying roll  86  is configured to be rotated by following the rotation of the developing roll  36 ; however, the supplying roll  86  may be configured to be driven by being rotated. 
     As the supplying roll  86 , for example, a sponge roll which impregnates and holds the washing liquid L, an anilox roll which includes plural concave portions in the outer peripheral surface and holds the washing liquid L in the concave portions, or the like is used. In the nozzle  88 , a supplying tube (not illustrated) supplying the washing liquid L using a pump from a storage tank which is not illustrated is connected. 
     When the supplying device  84  supplies the washing liquid L to the outer peripheral surface of the developing roll  36  being rotated, the washing liquid L is supplied to a contact portion between the developing roll  36  and the scraping blade  46 , and thus the washing liquid L causes the contact portion between the developing roll  36  and the scraping blade  46  to be washed (refer to  FIG. 2 ). 
     The controller  82  controls an operation of the contact and separation device  80 , and allows the scraping blade  46  to be in contact with the outer peripheral surface of the developing roll  36 , or to separate the scraping blade  46  from the outer peripheral surface of the developing roll  36 . As illustrated in  FIG. 3 , if the scraping blade  46  is separated from the outer peripheral surface of the developing roll  36 , the washing liquid L is supplied to the outer peripheral surface of the developing roll  36  being rotated from the supplying device  84 , and the washing liquid L is applied to the outer peripheral surface of the developing roll  36 . 
     That is, the controller  82  has a function of switching a first state in which the washing liquid L is supplied to the developing roll  36  in a state in which the scraping blade  46  is in contact with the developing roll  36  which is being rotated, to a second state in which the scraping blade  46  is separated from the developing roll  36  which is being rotated, and then the washing liquid L is applied to the developing roll  36 . In the exemplary embodiment, as an example, the controller  82  sets a state to be the first state after forming an image, and thus the washing liquid L causes the contact portion between the scraping blade  46  and the developing roll  36  to be washed. In addition, the controller switches the state to be the second state after the washing liquid L washes the contact portion between the scraping blade  46  and the developing roll  36 . In the exemplary embodiment, “after washing” means a predetermined time has elapsed from starting washing. That is, the controller  82  switches the state to the second state, after a predetermined time elapses from starting washing. Moreover, “after washing” may mean that the developing roll  36  is rotated at the number of rotations which is predetermined. In addition, in the exemplary embodiment, as an example, after the first state when an image is formed, and the state is switched to the second state; however, the invention is not limited to such a configuration. For example, switching between the first state and the second state may be carried out before forming an image or during forming an image, and the state may be switched from the second state to the first state. 
     Action and Effect 
     Next, an action and effect of the image forming apparatus  10  of the exemplary embodiment will be described with reference to a cleaning method of the exemplary embodiment. 
     As illustrated in  FIG. 2 , as an example, the controller  82  rotates the developing roll  36  in the arrow D direction in a state in which the scraping blade  46  is in contact with the developing roll  36  after forming an image (after a series of an image forming process is finished). Accordingly, the washing liquid L is supplied from the supplying roll  86  of the supplying device  84  to the outer peripheral surface of the developing roll  36 , and the washing liquid L is supplied to the contact portion between the developing roll  36  and the scraping blade  46  due to rotation of the developing roll  36 . A state in which the washing liquid L is supplied to the developing roll  36  is the first state. Accordingly, the scraping blade  46  and the contact portion between the developing roll  36  and the scraping blade  46  are washed by the washing liquid L (first process). 
     As illustrated in  FIG. 3 , after the first state, that is, after a predetermined time has elapsed from starting washing, when the controller  82  operates the contact and separation device  80  in a state in which the developing roll  36  is rotated in the arrow D direction, the scraping blade  46  is separated from the developing roll  36 . Accordingly, when the washing liquid L is supplied from the supplying roll  86  of the supplying device  84  to the outer peripheral surface of the developing roll  36 , the washing liquid L is applied to the outer peripheral surface of the developing roll  36  (second process). The controller  82  stops rotation of the developing roll  36  in a state in which the scraping blade  46  is separated from the developing roll  36 . A state in which the washing liquid L is applied to the outer peripheral surface of the developing roll  36  is the second state. Therefore, accumulating of the liquid developer G in the contact portion between the developing roll  36  and the scraping blade  46  is suppressed, and drying and fixing of the liquid developer G which is accumulated in the contact portion between the developing roll  36  and the scraping blade  46  is suppressed. 
     In the image forming apparatus  10 , as compared to a configuration in which the cleaning member comes into contact with the holding member at the time of stopping rotation of a holding member, cleaning failure or an image quality defect due to drying and fixing of the liquid developer G accumulated in the contact portion between the developing roll  36  and the scraping blade  46  is suppressed. 
     Also, in the cleaning method using the above described image forming apparatus  10 , as compared to the cleaning method in which the cleaning member comes into contact with the holding member at the time of stopping rotation of the holding member, cleaning failure or an image quality defect due to drying and fixing of the liquid developer G accumulated in the contact portion between the developing roll  36  and the scraping blade  46  is suppressed. 
     First Modification Example 
     In the image forming apparatus  10  described above, an example in which the supplying device  84  is provided to the developing roll  36  and the washing liquid L is supplied is described, but instead of the developing roll  36 , the washing liquid L may be supplied by providing the supplying device to the image holding member  22  as an example of the holding member. 
     In the image forming apparatus  10  of a first modification example, it is not illustrated, but in the scraping blade  32  as an example of the cleaning member of the image holding member  22 , the contact and separation device is provided as an example of the switching mechanism. In addition, the controller  82  as an example of the switching mechanism allows the scraping blade  32  to be brought into contact with the outer peripheral surface of the image holding member  22  by controlling operation of the contact and separation device, or to separate the scraping blade  32  from the outer peripheral surface of the image holding member  22 . Further, as an example, the controller  82  switches the first state in which the washing liquid L is supplied to the image holding member  22  in a state in which the scraping blade  32  is in contact with the image holding member  22  which is being rotated after forming an image, to the second state in which the washing liquid L is applied to the image holding member  22  in which the scraping blade  32  is separated from the image holding member  22  which is being rotated. In the first state, the scraping blade  32  and a contact portion between the scraping blade  32  and the image holding member  22  are washed by the washing liquid L supplied to the image holding member  22 , and the state is switched to the second state after the washing. 
     In the image forming apparatus  10  of the first modification example, as compared to a configuration in which the cleaning member comes into contact with the holding member at the time of stopping rotation of the holding member, cleaning failure or an image quality defect due to drying and fixing the liquid developer G, which is accumulated in the contact portion between the image holding member  22  and the scraping blade  32 , is suppressed. 
     Second Modification Example 
     In the image forming apparatus  10  described above, an example in which the supplying device  84  is provided to the developing roll  36  and the washing liquid L is supplied is described, but instead of the developing roll  36 , the washing liquid L may be supplied by providing the supplying device to the transfer roll  50  as an example of the holding member. 
     In the image forming apparatus  10  of the second modification example, it is not illustrated, but in the scraping blade  56  as an example of the cleaning member of the transfer roll  50 , the contact and separation device as an example of the switching mechanism is provided. In addition, the controller  82  as an example of the switching mechanism allows the scraping blade  56  to be in contact with the outer peripheral surface of the transfer roll  50  by controlling an operation of the contact and separation device, or to separate the scraping blade  56  from the outer peripheral surface of the transfer roll  50 . Further, as an example, the controller  82  switches the first state in which the washing liquid L is supplied to the transfer roll  50  in a state in which the scraping blade  56  is in contact with the transfer roll  50  which is being rotated after forming an image, to the second state in which the scraping blade  56  is separated from the transfer roll  50  which is being rotated after washing, and then the washing liquid L is applied to the transfer roll  50 . In the first state, the scraping blade  56  and a contact portion between the scraping blade  56  and the transfer roll  50  are washed using the washing liquid L, and the state is switched to the second state after washing. 
     In the image forming apparatus  10  of the second modification example, as compared to a configuration in which the cleaning member comes into contact with the holding member at the time of stopping rotation of the holding member, cleaning failure or an image quality defect due to drying and fixing of the liquid developer G accumulated in a contact portion between the transfer roll  50  and the scraping blade  56  is suppressed. 
     Second Exemplary Embodiment 
     Next, with reference to  FIG. 4  to  FIG. 8 , an image forming apparatus as a second exemplary embodiment of the invention will be described. Also, configuration parts the same as that of the first exemplary embodiment described before will be given the same numbers and description thereof will be omitted. 
     Configuration of Image Forming Apparatus 
     In  FIG. 4  to  FIG. 8 , an image forming section  102  used for an image forming apparatus  100  is illustrated. Four image forming sections  102  are disposed in actual, and basically has a same configuration except the liquid developer G to be used, and therefore, one image forming section  102  is illustrated, and description of image forming sections of four colors will be omitted. 
     As illustrated in  FIG. 4 , in the image forming section  102 , instead of the supplying device  84  disposed in the developing roll  36  of the first exemplary embodiment, a supplying device  104  which supplies the washing liquid L to the outer peripheral surface of the transfer roll  50  as an example of the holding member is included. The supplying device  84  includes the supplying roll  86  and the nozzle  88 . In the transfer roll  50 , the scraping blade  56  as an example of the cleaning member is provided, the supplying device  104  is disposed at an upstream side further than the scraping blade  56  in the rotation direction (arrow B direction) of the transfer roll  50 . In addition, the supplying device  104  is disposed at downstream side further than a transferring position to the continuous form paper P in the rotation direction (arrow B direction) of the transfer roll  50 . 
     Moreover, in the exemplary embodiment, the supplying device  104  is not provided at a position facing the image holding member  22  and the developing roll  36 . The image holding member  22  as an example of the other holding member is disposed to be in contact with the transfer roll  50 , and the washing liquid L attached to the outer peripheral surface of the transfer roll  50  is moved (transited) to the outer peripheral surface of the image holding member  22 . Further, the developing roll  36  is disposed to be in contact with the image holding member  22 , and the washing liquid L attached to the outer peripheral surface of the image holding member  22  is moved (transited) to the outer peripheral surface of the developing roll  36 . 
     The scraping blade  56  includes a plate-shaped blade portion  56 A which is in contact with the transfer roll  50  and scraps the liquid developer G remained on the outer peripheral surface of the transfer roll  50 , and a supporting member  56 B supporting the blade portion  56 A. The blade portion  56 A is disposed to be in contact with the transfer roll  50  so that a front edge of the blade portion  56 A is toward an upstream side of the rotation direction of the transfer roll  50 . In the scraping blade  56 , the contact and separation device  80  is provided as an example of a switching mechanism which allows the scraping blade  56  to be in contact with the outer peripheral surface of the transfer roll  50  or to separate the scraping blade  56  from the outer peripheral surface of the transfer roll  50 . 
     In addition, the scraping blade  32  as an example of the other cleaning member includes a plate-shaped blade portion  32 A which is in contact with the image holding member  22  and scraps the liquid developer G remained the outer peripheral surface of the image holding member  22 , and a supporting member  32 B supporting the blade portion  32 A. The blade portion  32 A is disposed to be in contact with the image holding member  22  so that a front edge of the blade portion  32 A is toward an upstream side of the rotation direction of the image holding member  22 . In the scraping blade  32 , the contact and separation device  80  is provided as an example of a switching mechanism which allows the scraping blade  32  to be in contact with the outer peripheral surface of the image holding member  22 , or to separate the scraping blade  32  from the outer peripheral surface of the image holding member  22 . 
     In the image forming apparatus  100 , a controller  106  is provided as an example of a switching mechanism which respectively controls an operation of the contact and separation device  80  of the scraping blade  56 , an operation of the contact and separation device  80  of the scraping blade  32 , and an operation of the contact and separation device  80  of the scraping blade  46 . In addition, motors (not illustrated) are respectively connected to the image holding member  22 , the developing roll  36 , and the transfer roll  50 , and the controller  106  controls rotational operation of the motors respectively connected to the image holding member  22 , the developing roll  36 , and the transfer roll  50 . Moreover, the controller  106  respectively reversely rotates the image holding member  22 , the developing roll  36 , and the transfer roll  50  by reversely rotating the motors respectively connected to the image holding member  22 , the developing roll  36 , and the transfer roll  50 . 
     Further, in the image forming apparatus  100 , an evacuation device (not illustrated) is provided which evacuates the continuous form paper P and the backup roll  52  at a position separated from the transfer roll  50  in a washing process. 
     In a washing process, when the supplying device  104  supplies the washing liquid L to the outer peripheral surface of the transfer roll  50  which is being rotated in the arrow B direction, the washing liquid L is supplied to a contact portion between the transfer roll  50  and the scraping blade  56 , and thus the contact portion between the transfer roll  50  and the scraping blade  56  is washed with the washing liquid L (refer to  FIG. 4 ). 
     In addition, the controller  106  separates the scraping blade  56  from the outer peripheral surface of the transfer roll  50  by the contact and separation device  80  after washing. Accordingly, when the washing liquid L is supplied from the supplying device  104  to the outer peripheral surface of the transfer roll  50  which is being rotated, the washing liquid L is applied to the outer peripheral surface of the transfer roll  50  (refer to  FIG. 5 ). At this time, when the image holding member  22  is rotated in the arrow C direction while being in contact with the transfer roll  50 , the washing liquid L is moved (transited) from the transfer roll  50  to the image holding member  22 , and the washing liquid L is supplied to the contact portion between the image holding member  22  and the scraping blade  32 . Accordingly, the contact portion between the image holding member  22  and the scraping blade  32  is washed with the washing liquid L (refer to  FIG. 5 ). 
     That is, as an example, the controller  106  has a function of switching the first state in which the washing liquid L is supplied to the transfer roll  50  in a state in which the scraping blade  56  is in contact with the transfer roll  50  which is being rotated after forming an image, to the second state in which the scraping blade  56  is separated from the transfer roll  50  which is being rotated and the washing liquid L is applied to the transfer roll  50  (refer to  FIG. 5 ). In the first state, the scraping blade  56  and the contact portion between the scraping blade  56  and the transfer roll  50  are washed with the washing liquid L. In the second state, the scraping blade  32  and the contact portion between the scraping blade  32  and the image holding member  22  are washed with the washing liquid L supplied from the outer peripheral surface of the transfer roll  50  to the image holding member  22  which is being rotated (refer to  FIG. 5 ). 
     In addition, the controller  106  has a function of switching the second state to a third state in which the scraping blade  32  is separated from the image holding member  22  which is being rotated and the washing liquid L is applied to the image holding member  22  (refer to  FIG. 6 ). In the third state, the scraping blade  46  and a contact portion between the scraping blade  46  and the developing roll  36  are washed with the washing liquid L supplied from the outer peripheral surface of the image holding member  22  to the developing roll  36  which is being rotated (refer to  FIG. 6 ). 
     In addition, the controller  106  has a function of switching the third state to a fourth state in which the scraping blade  46  is separated from the developing roll  36  which is being rotated and the washing liquid L is applied to the developing roll  36  (refer to  FIG. 7 ). 
     Further, in the image forming apparatus  100 , as an example, before forming an image (for example, before starting an image forming operation such as supplying power), the controller  106  rotates the image holding member  22 , the developing roll  36 , and the transfer roll  50  in a state in which all of the scraping blades  32 ,  46 , and  56  are separated from the image holding member  22 , the developing roll  36 , and the transfer roll  50 . Accordingly, the washing liquid L is applied to the outer peripheral surfaces of the image holding member  22 , the developing roll  36 , and the transfer roll  50 . After that, the controller  106  switches the state to a reverse rotation state in which the transfer roll  50 , the image holding member  22 , and the developing roll  36  are reversely rotated, in a state in which all of the scraping blades  32 ,  46 , and  56  are respectively in contact with the image holding member  22 , the developing roll  36 , and the transfer roll  50 . More specifically, the controller  106  rotates the transfer roll  50 , the image holding member  22 , and the developing roll  36  in a reverse direction (arrow F direction, arrow G direction, and arrow H direction) by reversely rotating motors (not illustrated) respectively connected to the transfer roll  50 , the image holding member  22 , and the developing roll  36  (refer to  FIG. 8 ). 
     Action and Effect 
     Next, action and effect of the image forming apparatus  100  of the exemplary embodiment will be described with reference to a cleaning method of the exemplary embodiment. 
     As illustrated in  FIG. 4 , as an example, the controller  106  rotates the transfer roll  50  in the arrow B direction in a state in which the scraping blade  56  is in contact with the transfer roll  50  after forming an image (after finishing a series of image forming processes). Accordingly, the washing liquid L is supplied from the supplying device  104  to the outer peripheral surface of the transfer roll  50 , and the washing liquid L is supplied to the contact portion between the transfer roll  50  and the scraping blade  56 . Therefore, in the first state, the scraping blade  56  and the contact portion between the transfer roll  50  and the scraping blade  56  are washed with the washing liquid L (first process). 
     As illustrated in  FIG. 5 , after the first state, that is, as an example, after a predetermined time elapsed from starting washing in the first state, in a state in which the transfer roll  50  is rotated in the arrow B direction, the controller  106  switches the state to the second state in which the scraping blade  56  is separated from the transfer roll  50  by the contact and separation device  80 . Accordingly, when the washing liquid L is supplied from the supplying device  104  to the outer peripheral surface of the transfer roll  50 , the washing liquid L is applied to the outer peripheral surface of the transfer roll  50  (second process). In addition, in the second state, the image holding member  22  being in into contact with the transfer roll  50  is rotated in the arrow C direction, and the scraping blade  32  is in contact with the image holding member  22 . Accordingly, when the washing liquid L is supplied from the outer peripheral surface of the transfer roll  50  to the image holding member  22  which is being rotated, the scraping blade  32  and the contact portion between the scraping blade  32  and the image holding member  22  are washed (second process). 
     As illustrated in  FIG. 6 , after the second state, that is, as an example, after a predetermined time elapsed from starting washing in the second state, in a state in which the image holding member  22  is rotated in the arrow C direction, the controller  106  switches the state to the third state in which the scraping blade  32  is separated from the image holding member  22  by the contact and separation device  80 . Accordingly, when the washing liquid L is supplied from the transfer roll  50  to the outer peripheral surface of the image holding member  22 , the washing liquid L is applied to the outer peripheral surface of the image holding member  22  (third process). In addition, in the third state, the developing roll  36  being in contact with the image holding member  22  is rotated in the arrow D direction, and the scraping blade  46  is in contact with the developing roll  36 . Accordingly, when the washing liquid L is supplied from the outer peripheral surface of the image holding member  22  to the developing roll  36  which is being rotated, the scraping blade  46  and the contact portion between the scraping blade  46  and the developing roll  36  are washed (third process). 
     As illustrated in  FIG. 7 , after the third state, that is, as an example, after a predetermined time elapsed from starting washing in the third state, in a state in which the developing roll  36  is rotated in the arrow D direction, the controller  106  switches the state to the fourth state in which the scraping blade  46  is separated from the developing roll  36  by the contact and separation device  80 . Accordingly, when the washing liquid L is supplied from the outer peripheral surface of the image holding member  22  to the outer peripheral surface of the developing roll  36 , the washing liquid L is applied to the outer peripheral surface of the developing roll  36  (fourth process). In this state, rotation of the transfer roll  50 , the image holding member  22 , and the developing roll  36  is stopped. In other words, in a state in which the scraping blade  56 , the scraping blade  32 , and the scraping blade  46  are respectively separated from the transfer roll  50 , the image holding member  22 , and the developing roll  36 , rotation of the transfer roll  50 , the image holding member  22 , and the developing roll  36  is stopped. Therefore, accumulation of the liquid developer G in the contact portion between the transfer roll  50  and the scraping blade  56 , the contact portion between the image holding member  22  and the scraping blade  32 , and the contact portion between the developing roll  36  and the scraping blade  46  are suppressed, and drying and fixing of the liquid developer G is suppressed. 
     In the image forming apparatus  100 , as compared to a configuration in which the cleaning member comes into contact with the holding member at the time of stopping rotation of the holding member, cleaning failure or an image quality defect due to drying and fixing of the liquid developer G accumulated in the contact portion between the transfer roll  50  and the scraping blade  56  is suppressed. In addition, in the image forming apparatus  100 , as compared to a configuration in which the other cleaning member at the time of stopping rotation of the other holding member comes into contact with the other holding member, cleaning failure or an image quality defect, due to drying and fixing of the liquid developer G, which is accumulated in the contact portion between the image holding member  22  and the scraping blade  32  and the contact portion between the developing roll  36  and the scraping blade  46 , is suppressed. 
     In addition, in the image forming apparatus  100 , as an example, before forming an image (for example, before starting an image forming operation such as supplying power), the controller  106  rotates the image holding member  22  in the arrow C direction, rotates the developing roll  36  in the arrow D direction, and rotates the transfer roll  50  in the arrow B direction, in a state in which all of the scraping blades  32 ,  46 , and  56  are separated from the image holding member  22 , the developing roll  36 , and the transfer roll  50 . Accordingly, the washing liquid L is applied to the outer peripheral surfaces of the image holding member  22 , the developing roll  36 , and the transfer roll  50  (refer to  FIG. 7 ). After that, as illustrated in  FIG. 8 , the controller  106  reversely rotates the transfer roll  50  to the arrow F direction, reversely rotates the image holding member  22  to the arrow G direction, and reversely rotates the developing roll  36  to the arrow H direction, in a state in which all of the scraping blades  32 ,  46 , and  56  are respectively in contact with the image holding member  22 , the developing roll  36 , and the transfer roll  50  (reverse rotation state). Accordingly, the image holding member  22 , the developing roll  36 , and the transfer roll  50  are slid to a direction where load is low with respect to the scraping blades  32 ,  46 , and  56  (front edge direction). 
     In the image forming apparatus  100 , as compared to a case in which the scraping blades  32 ,  46 , and  56  are dried and brought into contact with the image holding member  22 , the developing roll  36 , and the transfer roll  50 , damage due to friction of each member is suppressed. Further, as compared to a case in which a rotation direction of the holding member is determined (holding member is not in a reverse rotation state), unevenness generated in a thickness of the washing liquid L of the outer peripheral surface of the transfer roll  50  is suppressed. In addition, in the image forming apparatus  100 , as compared to a case in which a rotation direction of the other holding member is determined (the other holding member is not in the reverse rotation state), unevenness generated in a thickness of the washing liquid L of the outer peripheral surface of the image holding member  22  and the developing roll  36  is suppressed. 
     Moreover, in the first exemplary embodiment and the second exemplary embodiment, the supplying device includes the supplying roll  86  and the nozzle  88 ; however, the invention is not limited to such a configuration, and is changeable. 
     In addition, in the image forming apparatus  100  of the second exemplary embodiment, in a case in which a washing liquid applying member is basically disposed on the transfer roll  50 , the supplying device  104  may be used with the washing liquid applying member. 
     In addition, in the image forming apparatus  10  of the first exemplary embodiment, the first state in which the washing liquid L is supplied from the supplying device  84  to the developing roll  36  and the contact portion between the developing roll  36  and the scraping blade  46  is washed with the washing liquid L (refer to  FIG. 2 ), and the second state in which the washing liquid L is applied to the outer peripheral surface of the developing roll  36  (refer to  FIG. 3 ) are described; however, the invention is not limited thereto. For example, the washing liquid L is supplied from the developing roll  36  to the image holding member  22  and the contact portion of the image holding member  22  and the scraping blade is washed, the washing liquid L is applied to the outer peripheral surface of the image holding member  22 , and the washing liquid L is supplied from the image holding member  22  to the transfer roll  50 . Then, a contact portion between the transfer roll  50  and the scraping blade is washed, and the washing liquid L may be applied to the outer peripheral surface of the transfer roll  50  so as to be in a reverse direction to the image forming apparatus  100  of the second exemplary embodiment. 
     In addition, in the image forming apparatus  100  of the second exemplary embodiment, a state is switched in the order of the first state, the second state, the third state, and the fourth state; however, the invention is not limited to such a configuration. For example, the second state may be switched to the first state, the third state may be switched to the second state, and the fourth state may be switched to the third state. 
     In addition, in the first exemplary embodiment and the second exemplary embodiment, as a contact and separation device which allows the scraping blade to be brought into contact with or separated from the holding member, a cylinder is used; however, the invention is not limited thereto. For example, a contact and separation device such as a cam, an actuator, a rack and pinion may be used. 
     Further, in the first exemplary embodiment and the second exemplary embodiment, the plate-shaped scraping blades  32 ,  46 , and  56  are used; however, exemplary embodiments of the invention is not limited to the plate-shaped cleaning member, and the other shape of the cleaning member may be used. 
     The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.