Patent Publication Number: US-9835984-B2

Title: Liquid developer supply device, developing device, and image forming apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2016-026697 filed Feb. 16, 2016. 
     BACKGROUND 
     Technical Field 
     The present invention relates to a liquid developer supply device, a developing device, and an image forming apparatus. 
     SUMMARY 
     According to an aspect of the invention, there is provided a liquid developer supply device including: 
     a supply roller that rotates and holds liquid developer in a recessed portion formed in an outer circumferential surface to supply the liquid developer to a receiving member; 
     a liquid developer supply unit that supplies liquid developer between a seal member which is in contact with the supply roller on an upstream side in a rotating direction and a regulation member which is in contact with the supply roller on a downstream side, and that forms a liquid developer reservoir; and 
     a supply unit that supplies a cleaning liquid to a contact portion from an upstream side of the contact portion between the supply roller and the seal member, in the rotating direction of the supply roller, such that the cleaning liquid flows down along the seal member due to gravity. 
    
    
     
       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 view showing a configuration of an image forming apparatus including a liquid developer supply device according to a first exemplary embodiment of the invention; 
         FIG. 2  is a view showing a configuration of the liquid developer supply device and a developing device which are used in the image forming apparatus shown in  FIG. 1 ; 
         FIG. 3  is a view showing a configuration of the liquid developer supply device shown in  FIG. 2  and showing a state when an image is formed; 
         FIG. 4  is a view showing a configuration of a cleaning process in the liquid developer supply device shown in  FIG. 3 ; 
         FIG. 5  is a view showing a configuration of the cleaning process of the liquid developer supply device shown in  FIG. 3  and showing a state during cleaning; 
         FIG. 6  is a view showing a configuration of the liquid developer supply device of a second exemplary embodiment in a state in which cleaning is performed; 
         FIG. 7  is a view showing a configuration of the liquid developer supply device of a third exemplary embodiment in a state in which cleaning is performed; 
         FIG. 8  is a view showing a configuration of the liquid developer supply device of a fourth exemplary embodiment in a state in which cleaning is performed; 
         FIG. 9  is a view showing a configuration of the liquid developer supply device of a fifth exemplary embodiment in a state in which cleaning is performed; and 
         FIG. 10  is a view showing a configuration of the liquid developer supply device of a sixth exemplary embodiment in a state in which cleaning is performed. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, exemplary embodiments of an image forming apparatus of the invention will be described with reference to the drawings. Note that arrows UP shown in the drawings represent an upper side in a vertical direction of the apparatus. 
     First Exemplary Embodiment 
     Configuration of Image Forming Apparatus 
       FIG. 1  shows an example of an image forming apparatus  10  that includes a liquid developer supply device  40  of the first exemplary embodiment. As shown in  FIG. 1 , the image forming apparatus  10  includes a transport member (not shown) that transports continuous paper P as an example of a recording medium in a direction of arrow A, an image forming system  14  that forms a toner image on the continuous paper P, and a fixing device  16  that fixes the toner image to the continuous paper P. The image forming system  14  includes an image forming system  14 Y that forms a yellow (Y) toner image, an image forming system  14 M that forms a magenta (M) toner image, an image forming system  14 C that forms a cyan (C) toner image, and an image forming system  14 K that forms a black (K) toner image. In the image forming apparatus  10 , as an example, the image forming systems  14 Y,  14 M,  14 C, and  14 K are arranged in this order from an upstream side in a transport direction of the continuous paper P. 
     Each of the image forming systems  14 Y,  14 M,  14 C, and  14 K of the respective colors includes an image forming unit  18  that forms a toner image using liquid developer G in which toner and an insulating liquid are contained, and a transfer unit  20  that transfers the toner image formed by the image forming unit  18  to the continuous paper P. In the exemplary embodiment, the continuous paper P is transported by the transport member (not shown) in a lateral direction (direction of the arrow A) and the image forming systems  14 Y,  14 M,  14 C, and  14 K of the respective colors are arranged side by side in the lateral direction. 
     As shown in  FIG. 2 , the image forming unit  18  includes an image holding member  22  that rotates and holds a toner image, a charging device  24  that charges the image holding member  22 , an exposure device  26  that irradiates the image holding member  22  with exposure light so as to form an electrostatic latent image, and a developing device  28  that develops, as a toner image, the electrostatic latent image on the image holding member  22 . Further, the image forming unit  18  is provided with a cleaning device  34  that includes a scraping blade  30  that scrapes, from the image holding member  22 , the liquid developer G remaining on an outer circumferential surface of the image holding member  22  such that no image is transferred to a transfer roller  50 , which will be described below, from the image holding member  22 , and a collecting member  32  that collects the scraped liquid developer G. 
     The developing device  28  includes a developing roller  36  as an example of a receiving member, which rotates and develops the electrostatic latent image formed on the image holding member  22  with the liquid developer G. In addition, the developing device  28  includes the liquid developer supply device  40  that supplies the liquid developer G to the developing roller  36 , and a charging device  42  that charges toner contained in the liquid developer G supplied to the developing roller  36 . Further, the developing device  28  is provided with a cleaning device  48  that includes a scraping blade  44  that scrapes, from the developing roller  36 , the liquid developer G remaining on an outer circumferential surface of the developing roller  36  after development, and a collecting member  46  that collects the scraped liquid developer G. 
     The liquid developer G used in the exemplary embodiment is a liquid type of developer in which toner (particles) is dispersed in a carrier liquid, and as the carrier liquid, an insulating liquid such as vegetable oil, liquid paraffin oil, or silicone oil is used. In addition, an average particle diameter of the toner in the liquid developer G is, as an example, 0.5 μm to 5 μm, and the toner (particles) is dispersed at a concentration of 15 wt % to 45 wt % in the carrier liquid. 
     In the developing device  28 , the toner contained in the liquid developer G supplied to the outer circumferential surface of the developing roller  36  is charged by the charging device  42  such that the electrostatic latent image on the image holding member  22  is developed as a toner image with the liquid developer G on the outer circumferential surface of the developing roller  36 . Note that, in a case where the electrostatic latent image is developed as the toner image using the liquid developer G, the carrier liquid also migrates to the image holding member  22 . 
     The transfer unit  20  includes the transfer roller  50  which is rotatably disposed to face the image holding member  22  and to which the toner image on the image holding member  22  is transferred by an electric field formed between the image holding member  22  and the transfer roller  50 . Further, the transfer unit  20  includes a backup roller  52  that is disposed on a side opposite to the transfer roller  50  with the continuous paper P interposed therebetween, and that transfers the toner image on the transfer roller  50  to the continuous paper P by an electric field formed between the transfer roller  50  and the backup roller  52 . Furthermore, the transfer unit  20  is provided with a cleaning device  58  that includes a scraping blade  54  that scrapes, from the transfer roller  50 , the liquid developer G remaining on an outer circumferential surface of the transfer roller  50  after the transfer, and a collecting member  56  that collects the scraped liquid developer G. 
     In the transfer unit  20 , the toner image on the image holding member  22  is transferred to the transfer roller  50  and the toner image transferred to the transfer roller  50  is transferred to the continuous paper P. Note that the carrier liquid migrating from the developing roller  36  to the image holding member  22  also migrates to the continuous paper P via the transfer roller  50 . 
     As shown in  FIG. 1 , the fixing device  16  includes a heating unit  60  that heats the continuous paper P, a carrier liquid removing unit  62  that removes the carrier liquid from the continuous paper P, and a fixing unit  64  that fixes the toner image to the continuous paper P. Each of the carrier liquid removing unit  62  and the fixing unit  64  includes a heating roller  65  and a pressure roller  66  that presses the continuous paper P against the heating roller  65 . 
     In the fixing device  16 , the heating unit  60  heats the continuous paper P, the toner and the carrier liquid (oil) contained in the liquid developer G on the continuous paper P are separated from each other, and then an oil layer is formed on the toner. Further, the carrier liquid (oil) is removed by the carrier liquid removing unit  62 , and the continuous paper P is heated and pressurized by the fixing unit  64  such that the toner image is fixed to the continuous paper P. 
     In the image forming apparatus  10  described above, the image holding member  22  of the image forming units  18  of the respective colors rotates and the outer circumferential surface of the image holding member  22  is charged by the charging device  24 . Next, the outer circumferential surface of the image holding member  22  is exposed by the exposure device  26 , and the electrostatic latent image is formed on the outer circumferential surface of the image holding member  22 . Then, the electrostatic latent image is developed as the toner image by the developing device  28 . Further, the toner image formed on the outer circumferential surface of the rotating image holding member  22  is primarily transferred to the transfer roller  50 . The toner image primarily transferred to the transfer roller  50  is transferred to the continuous paper P which is transported in the direction of the arrow A. This process is performed in the image forming systems  14  of the respective colors, and a toner image, on which the respective colors are superimposed, is formed on the continuous paper P. Further, the carrier liquid (oil) is removed on the transported continuous paper P by the fixing device  16 , and the toner image is fixed to the continuous paper P. 
     Configuration of Liquid Developer Supply Device 
     Next, the liquid developer supply device  40  will be described. 
       FIG. 3  shows a state of the liquid developer supply device  40  of the first exemplary embodiment when an image is formed. As shown in  FIG. 3 , the liquid developer supply device  40  includes a supply roller  70  that rotates and holds the liquid developer G so as to supply the liquid developer G to the developing roller  36  (refer to  FIG. 2 ), and a chamber  72  as an example of a liquid developer supply unit that supplies the liquid developer G to the supply roller  70 . In addition, the liquid developer supply device  40  includes a cleaning liquid supply device  74  as an example of a supply unit that supplies, when cleaning the supply roller  70 , a cleaning liquid L to a contact portion  79  from an upstream side of the contact portion  79  between the supply roller  70  and a seal blade  78  which will be described below (refer to  FIG. 5 ). 
     The supply roller  70  is an anilox roller that holds the liquid developer G and supplies the liquid developer G to a contact portion (refer to  FIG. 2 ) with the developing roller  36 . To be more specific, the supply roller  70  has plural cells  70 A as an example of recessed portions that are arranged in the outer circumferential surface thereof and are recessed to the inner side in a radial direction. The cell  70 A has a volume that may hold the liquid developer G and, with the volume, a pattern of arrangement of the cells  70 A is unlikely to be viewed in the toner image. The cell is, as an example, about 12 ml (milliliters)/m 2  in volume. Note that  FIG. 3  is a schematic view showing the plural rectangular cells  70 A arranged in the outer circumferential surface of the supply roller  70  at intervals; however, in reality, the supply roller  70  has the cells  70 A which are smaller in size and the cells  70 A are arranged at narrower intervals. 
     The chamber  72  includes a storage member  76  that stores the liquid developer G, the seal blade  78  as an example of a seal member that is disposed on an upstream side in a rotating direction (direction of arrow B) of the supply roller  70 , and a regulation blade (doctor blade)  80  as an example of a regulation member which is disposed on a downstream side in the rotating direction of the supply roller  70 . The chamber  72  is disposed in a region in which the supply roller  70  rotates in the rotating direction (direction of the arrow B) from the lower side in the vertical direction toward the upper side in the vertical direction. 
     The storage member  76  is formed to have a box shape which is opened toward the supply roller  70  side. The storage member  76  is disposed to have the longitudinal direction thereof is matched with an axial direction of the supply roller  70 . To be more specific, the storage member  76  has a side portion  76 A disposed to face a circumferential surface of the supply roller  70  in a cross-sectional view, a downstream-side protruding portion  76 B that protrudes from one end portion (end portion on the downstream side in the rotating direction of the supply roller  70 ) of the side portion  76 A toward the supply roller  70  side, and an upstream-side protruding portion  76 C that protrudes from the other end portion (end portion on the upstream side in the rotating direction of the supply roller  70 ) of the side portion  76 A toward the supply roller  70  side. In the exemplary embodiment, the side portion  76 A of the storage member  76  is disposed in the vertical direction, the downstream-side protruding portion  76 B is disposed at an upper end portion of the side portion  76 A, and the upstream-side protruding portion  76 C is disposed at a lower end portion of the side portion  76 A. Each of the downstream-side protruding portion  76 B and the upstream-side protruding portion  76 C is formed to have a trapezoidal shape of which a length in the vertical direction is reduced toward the supply roller  70  side. 
     A base end portion  78 A of the seal blade  78  is supported in the upstream-side protruding portion  76 C of the storage member  76 . A front end portion  78 B of the seal blade  78  is in contact with the outer circumferential surface of the supply roller  70 , and the contact portion  79  is formed between the front end portion  78 B of the seal blade  78  and the supply roller  70 . The seal blade  78  is disposed to be inclined such that the front end portion  78 B is disposed on the upper side from the base end portion  78 A in the vertical direction. In other words, the seal blade  78  is disposed so as to be sloped downward to the base end portion  78 A side from the front end portion  78 B that is in contact with the supply roller  70 . The front end portion  78 B of the seal blade  78  is in contact with the supply roller  70  in a direction toward the downstream side in the rotating direction (direction of the arrow B) of the supply roller  70 . The seal blade  78  is formed of, as an example, metal such as stainless steel. 
     A base end portion  80 A of the regulation blade  80  is supported in the downstream-side protruding portion  76 B of the storage member  76 , and a front end portion  80 B of the regulation blade  80  is in contact with the outer circumferential surface of the supply roller  70 . The regulation blade  80  is disposed to be inclined such that the front end portion  80 B is disposed on the lower side from the base end portion  80 A in the vertical direction. In other words, the regulation blade  80  is disposed so as to be sloped upward to the base end portion  80 A side from the front end portion  80 B that is in contact with the supply roller  70 . The front end portion  80 B of the regulation blade  80  is in contact with the supply roller  70  in a direction toward the upstream side in the rotating direction (direction of the arrow B) of the supply roller  70 . The regulation blade  80  is formed of, as an example, metal such as stainless steel. 
     A supply tube (not shown), which supplies the liquid developer G from a storage tank (not shown) into the inner side of the storage member  76  using a pump, is connected to a lower portion of the side portion  76 A of the storage member  76 . In this manner, the liquid developer G flows into a portion surrounded by the storage member  76 , the seal blade  78 , and the regulation blade  80 , and a liquid developer reservoir  81  is formed in the inside (in the exemplary embodiment, the seal blade  78  side on the lower side in the vertical direction) of the chamber  72 . Note that a surplus of liquid developer G in the chamber  72  is discharged through a discharge tube (not shown) disposed on the upper side of the side portion  76 A of the storage member  76  to the outside of the chamber  72 . 
     The cleaning liquid supply device  74  has a function of supplying the cleaning liquid L to the contact portion  79  from the upstream side of the contact portion  79  between the supply roller  70  and the seal blade  78  in the rotating direction of the supply roller  70 , when the liquid developer supply device  40  is cleaned in a process different from the process executed when the image is formed. A cleaning process of the liquid developer supply device  40  is performed, as an example, after the image is formed or a predetermined period of time elapses after the image is formed. As shown in  FIG. 4 , the cleaning liquid supply device  74  includes a cleaning vessel  84  that is disposed on the lower side of the supply roller  70  and stores the cleaning liquid L. The cleaning vessel  84  is formed to have a bowl shape so as to surround an outer circumferential surface of the supply roller  70  on the lower side. In addition, the cleaning vessel  84  extends to a position so as to be disposed on the lower side from the chamber  72 . A supply tube (not shown), which supplies the cleaning liquid L from the storage tank (not shown) to the inside of the cleaning vessel  84  using a pump, is connected to a bottom wall of the cleaning vessel  84 . 
     As the cleaning liquid L, as an example, a carrier liquid that forms the liquid developer, or an organic solvent, in which any of isopropyl alcohol or acetone is contained, is used. 
     As shown in  FIG. 4 , the cleaning liquid L is supplied into the inside of the cleaning vessel  84  and, thereby, a cleaning liquid reservoir portion  85  is formed in the inside of the cleaning vessel  84 . In this manner, a lower portion of the supply roller  70  as an example of a part of the supply roller  70  is immersed into the cleaning liquid reservoir portion  85 . The lower portion of the supply roller  70  is immersed into the cleaning liquid reservoir portion  85  of the cleaning vessel  84  at a position on the upstream side of the contact portion  79  between the supply roller  70  and the seal blade  78  in the rotating direction (direction of the arrow B) of the supply roller  70  (refer to  FIG. 5 ). In other words, the seal blade  78  is disposed in a range in which the supply roller  70  moves upward from the cleaning liquid reservoir portion  85  of the cleaning vessel  84  (refer to  FIG. 5 ). 
     In the exemplary embodiment, the seal blade  78  is disposed on the lower side from the central portion of the supply roller  70  in the vertical direction. In addition, the seal blade  78  is disposed such that a surface thereof on the side opposite to the liquid developer reservoir  81  (refer to  FIG. 3 ) is directed downward. 
     As shown in  FIG. 5 , when the supply roller  70  is caused to rotate in the direction of the arrow B, the cleaning liquid L is attached to the outer circumferential surface of the supply roller  70  and is brought along in the direction of arrow C due to the rotation of the supply roller  70  (in the state of being attached to the outer circumferential surface of the supply roller  70 ). In this manner, the cleaning liquid L is supplied to the contact portion  79  from the upstream side of the contact portion  79  between the supply roller  70  and the seal blade  78 . Then, since the seal blade  78  is disposed to be sloped downward from the front end portion  78 B to the base end portion  78 A, the cleaning liquid L supplied to the contact portion  79  flows down along the seal blade  78  due to gravity (flows down along the lower surface of the seal blade  78 ). The cleaning vessel  84  is disposed at a position at which the cleaning liquid L after flowing down along the seal blade  78  is received, and thus, the cleaning liquid L after flowing down is collected in the cleaning vessel  84 . 
     In addition, a discharge tube (not shown), through which the cleaning liquid L is discharged, is connected to a bottom wall of the cleaning vessel  84 , and an on-off valve (not shown) is provided in the discharge tube. In the exemplary embodiment, as an example, the on-off valve is closed in the cleaning process such that the cleaning liquid L is supplied to the cleaning vessel  84 . In addition, in the exemplary embodiment, as an example, the on-off valve is opened after the cleaning process such that the cleaning liquid L is discharged from the cleaning vessel  84 . 
     An ultrasonic oscillator  86  as an example of a replacement portion is provided in a lower portion of the cleaning vessel  84 . The ultrasonic oscillator  86  is provided with an ultrasonic vibrator (not shown) that generates an ultrasonic wave and drives the ultrasonic vibrator, and thereby, the cleaning liquid L in the inside of the cleaning vessel  84  vibrates due to the ultrasonic wave and then, multiple fine bubbles are formed in the cleaning liquid L. The multiple fine bubbles in the cleaning liquid L collide with the outer circumferential surface of the supply roller  70  such that the liquid developer G in the cell  70 A of the supply roller  70  is replaced with the cleaning liquid L. 
     Operation and Effect 
     Next, operations and effects of the exemplary embodiment will be described. 
     As shown in  FIG. 3 , when an image is formed, in the liquid developer supply device  40 , the supply roller  70  rotates in the direction of the arrow B, the supply roller  70  comes into contact with the liquid developer reservoir  81  inside the chamber  72 , and thereby the liquid developer G is supplied to the outer circumferential surface of the supply roller  70 . Further, the outer circumferential surface of the supply roller  70  passes the contact portion with the regulation blade  80 , thereby the surplus of the liquid developer G on the outer circumferential surface of the supply roller  70  is scraped, and the liquid developer G is held in the cell  70 A of the supply roller  70 . As shown in  FIG. 2 , the supply roller  70  is in contact with the developing roller  36 , and the developing roller  36  rotates at a contact position with the supply roller  70  in the same direction as the supply roller. In this manner, the liquid developer G held in the cell  70 A of the supply roller  70  is supplied to the developing roller  36 . Then, the image is formed on the continuous paper P through a series of image forming processes of the image forming apparatus  10  (refer to  FIG. 1 ). 
     In the liquid developer supply device  40 , the cleaning process of cleaning the contact portion  79  between the supply roller  70  and the seal blade  78  is executed after the image is formed or after a predetermined period of time elapses after the image is formed. As shown in  FIG. 4 , in a state in which the rotation of the supply roller  70  is stopped, the on-off valve (not shown) of the cleaning vessel  84  is closed, and the cleaning liquid L is supplied to the inside of the cleaning vessel  84  through the supply tube (not shown). In this manner, the cleaning liquid reservoir portion  85  is formed inside the cleaning vessel  84 , and the lower portion of the supply roller  70  is immersed into the cleaning liquid reservoir portion  85 . 
     In this state, as shown in  FIG. 5 , when the supply roller  70  is caused to rotate in the direction of the arrow B, the cleaning liquid L is attached to the outer circumferential surface of the supply roller  70  with the rotation of the supply roller  70  and is brought along in the direction of arrow C. In this manner, the cleaning liquid L is supplied to the contact portion  79  from the upstream side of the contact portion  79  between the supply roller  70  and the seal blade  78 . Therefore, the upstream side of the contact portion  79  between the supply roller  70  and the seal blade  78  in the rotating direction (direction of the arrow B) of the supply roller  70  is cleaned with the cleaning liquid L, and an attached substance such as the high-concentration liquid developer attached on the upstream side of the contact portion  79  between the supply roller  70  and the seal blade  78  is removed. 
     In addition, the seal blade  78  is disposed to be sloped downward from the front end portion  78 B to the base end portion  78 A side. Therefore, the cleaning liquid L supplied to the upstream side of the contact portion  79  between the supply roller  70  and the seal blade  78  flows down along the seal blade  78  in a direction represented by arrow D due to gravity. In other words, the cleaning liquid L flows down along the lower surface of the seal blade  78  due to gravity. The cleaning liquid L flowing down along the lower surface of the seal blade  78  due to gravity is collected in the cleaning vessel  84 . 
     In addition, the ultrasonic oscillator  86  is provided in the cleaning vessel  84 , the cleaning liquid L of the cleaning liquid reservoir portion  85  inside the cleaning vessel  84  vibrates with the ultrasonic wave, and multiple fine bubbles are formed in the cleaning liquid L. The multiple fine bubbles in the cleaning liquid L collide with the outer circumferential surface of the supply roller  70  such that the liquid developer G in the cell  70 A of the supply roller  70  is replaced with the cleaning liquid L. 
     In the liquid developer supply device  40  of the exemplary embodiment, the high-concentration liquid developer accumulated in the contact portion  79  between the supply roller and the seal blade  78  is removed such that the high-concentration liquid developer enters into the chamber  72 , as compared with a configuration which does not include the cleaning liquid supply device that supplies the cleaning liquid to the contact portion between the supply roller and the seal blade such that the cleaning liquid flows down along the seal blade due to gravity. 
     In addition, in the liquid developer supply device  40 , the liquid developer G in the cell  70 A of the supply roller  70  is more likely to be replaced with the cleaning liquid L such that the cleaning efficiency is improved, as compared with a configuration which does not include, below the supply roller, the cleaning liquid reservoir portion into which a part of the supply roller is immersed. 
     Further, in the liquid developer supply device  40 , the liquid developer G in the cell  70 A of the supply roller  70  is more efficiently replaced with the cleaning liquid (replacement of the liquid developer G by the cleaning liquid L is promoted) such that the cleaning efficiency is still more improved, as compared with a configuration which does not include the ultrasonic oscillator  86  in the cleaning vessel  84 . 
     Second Exemplary Embodiment 
     Next, a liquid developer supply device as the second exemplary embodiment of the invention will be described with reference to  FIG. 6 . Note that the same reference signs are assigned to the same components as those in the first exemplary embodiment, and description thereof is omitted. 
     As shown in  FIG. 6 , a liquid developer supply device  90  includes the cleaning liquid supply device  74  below the supply roller  70 . In the cleaning liquid supply device  74 , instead of the ultrasonic oscillator  86  of the first exemplary embodiment, a brush  94  as an example of the replacement portion is disposed in the inside of the cleaning vessel  84  so as to be in contact with the outer circumferential surface of the supply roller  70 . The brush  94  has a shaft  94 A that is rotatably supported in a support member (not shown) provided in the cleaning vessel  84 , and multiple brush bristles  94 B provided around the shaft  94 A. The brush bristle  94 B has, as an example, a length which is sufficient for a front end of the brush bristle  94 B to come into contact with an inner wall of the cell  70 A of the supply roller  70 . In addition, the brush  94  is configured to rotate in a direction of arrow E along with the rotation of the supply roller  70 . 
     The brush  94  is disposed to be immersed into the cleaning liquid reservoir portion  85  in the cleaning vessel  84  with the entirety or a part of the brush left without being immersed. In the exemplary embodiment, the brush  94  is disposed to be in contact with the outer circumferential surface of the supply roller  70  at a position at which the supply roller  70  emerges from the cleaning liquid reservoir portion  85  of the cleaning vessel  84  with the rotation of the supply roller  70 . 
     In the liquid developer supply device  90 , the brush  94 , which is immersed in the cleaning liquid reservoir portion  85  in the cleaning vessel  84 , rotates in contact with the outer circumferential surface of the supply roller  70 . Therefore, the liquid developer G in the cell  70 A of the supply roller  70  is more efficiently replaced with the cleaning liquid L (replacement of the liquid developer G by the cleaning liquid L is promoted) such that the cleaning efficiency is improved, as compared with a configuration which does not include the brush in the cleaning liquid reservoir portion  85  in the cleaning vessel  84 . 
     Third Exemplary Embodiment 
     Next, a liquid developer supply device as the third exemplary embodiment of the invention will be described with reference to  FIG. 7 . Note that the same reference signs are assigned to the same components as those in the first and second exemplary embodiments, and description thereof is omitted. 
     As shown in  FIG. 7 , a liquid developer supply device  100  includes the cleaning liquid supply device  74  below the supply roller  70 . In the cleaning liquid supply device  74 , instead of the brush  94  of the second exemplary embodiment, a brush  102  as an example of the replacement portion is provided at a position at which the cleaning liquid L supplied to the supply roller  70  comes into contact with the supply roller. The brush  102  is provided at the position at which the seal blade  78  is in contact with the outer circumferential surface of the supply roller  70 , on the upstream side of the contact portion  79  between the supply roller  70  and the seal blade  78  in the rotating direction (direction of the arrow B) of the supply roller  70 . The brush  102  is rotatably supported to rotate in the direction of arrow E along with the rotation of the supply roller  70 . 
     In the liquid developer supply device  100 , the brush  102  is disposed on the upstream side of the contact portion  79  between the supply roller  70  and the seal blade  78  in the rotating direction of the supply roller  70 , and the brush  102  rotates in contact with the outer circumferential surface of the supply roller  70  and the seal blade  78 . Therefore, the liquid developer G in the cell  70 A of the supply roller  70  is more efficiently replaced with the cleaning liquid L (replacement of the liquid developer G by the cleaning liquid L is promoted) such that the cleaning efficiency is improved, as compared with a configuration which does not include the brush at the position at which the cleaning liquid supplied to the supply roller comes into contact with the supply roller. In this manner, the attached substance such as the high-concentration liquid developer attached on the supply roller  70  or the seal blade  78 , or the attached substance such as the high-concentration liquid developer attached in the vicinity of the contact portion  79  between the supply roller  70  and the seal blade  78  is removed. 
     Fourth Exemplary Embodiment 
     Next, a liquid developer supply device as the fourth exemplary embodiment of the invention will be described with reference to  FIG. 8 . Note that the same reference signs are assigned to the same components as those in the first to third exemplary embodiments, and description thereof is omitted. 
     As shown in  FIG. 8 , a liquid developer supply device  110  includes a chamber  112  as an example of a liquid developer supply unit, which is disposed at a position facing an obliquely lower side of the supply roller  70 , and a nozzle  114  as an example of an ejection portion through which the cleaning liquid L is ejected to the supply roller  70  on the upstream side of the chamber  112  in the rotating direction of the supply roller  70 . 
     The chamber  112  includes the storage member  76 , the seal blade  78 , and the regulation blade  80 . In the exemplary embodiment, the side portion  76 A of the storage member  76  is disposed to be inclined at a position facing an outer circumferential surface on the obliquely lower side of the supply roller  70 . The downstream-side protruding portion  763 , in which the regulation blade  80  is supported, is disposed on the lower end portion of the side portion  76 A, and the upstream-side protruding portion  76 C, in which the seal blade  78  is supported, is disposed on the upper end portion of the side portion  76 A. 
     The seal blade  78  is disposed in a range in which the supply roller  70  moves downward. In other words, the front end portion  78 B of the seal blade  78  is in contact with the supply roller  70  in the range in which the supply roller  70  moves downward. The seal blade  78  is disposed to be sloped downward from the front end portion  78 B to the base end portion  78 A. In the exemplary embodiment, the seal blade  78  is disposed below the central portion of the supply roller  70  in the vertical direction. In addition, in the exemplary embodiment, a liquid developer reservoir (not shown) is formed on the lower side of the chamber  112  on the regulation blade  80  side, and the seal blade  78  is disposed such that a surface thereof on the side opposite to the liquid developer reservoir (not shown) is directed downward. In addition, a collection member  116 , in which the cleaning liquid L after flowing down along the seal blade  78  due to gravity is collected, is provided below the side (back surface side) of the storage member  76  opposite to the supply roller  70 . 
     The nozzle  114  is disposed in the longitudinal direction of the supply roller  70  and the cleaning liquid L is continuously ejected through the nozzle to the rotating supply roller  70 , thereby having a function of supplying the cleaning liquid L to the outer circumferential surface of the supply roller  70 . A supply tube (not shown), through which the cleaning liquid L is supplied from the storage tank (not shown) using a pump, is connected to the nozzle  114 . 
     The nozzle  114  is disposed on the upper side from the seal blade  78  in the vertical direction. The nozzle  114  is an example of a supply unit such that the cleaning liquid L is supplied to the contact portion  79  from the upstream side of the contact portion  79  between the supply roller  70  and the seal blade  78  in the rotating direction of the supply roller  70 . 
     In the liquid developer supply device  110 , the cleaning liquid L is ejected through the nozzle  114  to the rotating supply roller  70 , and thereby the cleaning liquid L supplied to the outer circumferential surface of the supply roller  70  with the rotation of the supply roller  70  moves in a direction of arrow F. In this manner, the cleaning liquid L is supplied to the contact portion  79  between the supply roller  70  and the seal blade  78 . Therefore, the contact portion  79  between the supply roller  70  and the seal blade  78  is cleaned with the cleaning liquid L, and the attached substance such as the high-concentration liquid developer accumulated on the upstream side of the contact portion  79  between the supply roller  70  and the seal blade  78  is removed. Further, the cleaning liquid L flows down along the seal blade  78  in a direction represented by arrow G due to gravity. In other words, the cleaning liquid L flows down along the top surface of the seal blade  78  due to gravity. The cleaning liquid L after flowing down along the top surface of the seal blade  78  due to gravity flows along the top surface of the storage member  76  and is collected in the collection member  116  on the back surface side of the storage member  76 , in a direction represented by arrow H. 
     In the liquid developer supply device  110 , high-concentration liquid developer accumulated in the contact portion  79  between the supply roller  70  and the seal blade  78  is removed such that the high-concentration liquid developer enters into the inside of the chamber  72 , as compared with a configuration which does not include the supply unit that supplies the cleaning liquid to the contact portion between the supply roller and the seal blade such that the cleaning liquid flows down along the seal blade due to gravity. In addition, flexibility in selection of a position, at which the cleaning liquid L is supplied to the supply roller  70 , is improved, as compared with a configuration which does not include the nozzle through which the cleaning liquid is ejected to the supply roller. 
     Further, the cleaning liquid L used in cleaning the contact portion  79  between the seal blade  78  and the supply roller  70  mixes with the cleaning liquid L ejected from the nozzle  114 , as compared with a configuration in which the nozzle is disposed below the seal blade. 
     Fifth Exemplary Embodiment 
     Next, a liquid developer supply device as the fifth exemplary embodiment of the invention will be described with reference to  FIG. 9 . Note that the same reference signs are assigned to the same components as those in the first to fourth exemplary embodiments, and description thereof is omitted. 
     As shown in  FIG. 9 , a liquid developer supply device  120  includes the brush  102  as an example of the replacement portion, which is provided at a position at which the cleaning liquid L supplied to the supply roller  70  comes into contact with the supply roller. The brush  102  is provided at the position at which the seal blade  78  is in contact with the outer circumferential surface of the supply roller  70 , on the upstream side of the contact portion  79  between the supply roller  70  and the seal blade  78  in the rotating direction (direction of the arrow B) of the supply roller  70 . The brush  102  rotates in the direction of the arrow E along with the rotation of the supply roller  70 . 
     In the liquid developer supply device  120 , the liquid developer G in the cell  70 A of the supply roller  70  is more efficiently replaced with the cleaning liquid L (replacement of the liquid developer G by the cleaning liquid L is promoted) such that the cleaning efficiency is improved, as compared with a configuration which does not include the brush at the position at which the cleaning liquid supplied to the supply roller comes into contact with the supply roller. In this manner, the attached substance such as the high-concentration liquid developer attached on the supply roller  70  or the seal blade  78 , or the attached substance such as the high-concentration liquid developer attached in the vicinity of the contact portion  79  between the supply roller  70  and the seal blade  78  is removed. 
     Note that the position of the brush  102  is not limited to that in the exemplary embodiment, but may be changed as long as the cleaning liquid L supplied to the supply roller  70  comes into contact with the supply roller at the position. 
     Sixth Exemplary Embodiment 
     Next, a liquid developer supply device as the sixth exemplary embodiment of the invention will be described with reference to  FIG. 10 . Note that the same reference signs are assigned to the same components as those in the first to fifth exemplary embodiments, and description thereof is omitted. 
     As shown in  FIG. 10 , a liquid developer supply device  130  includes a chamber  132  as an example of the liquid developer supply unit, which is disposed at a position facing an upper portion of the supply roller  70 , and the nozzle  114  as an example of the ejection portion through which the cleaning liquid L is ejected to the supply roller  70  on the upstream side of the chamber  132  in the rotating direction of the supply roller  70 . 
     The chamber  132  includes the storage member  76 , the seal blade  78 , and the regulation blade  80 . In the exemplary embodiment, the side portion  76 A of the storage member  76  is disposed in a lateral direction so as to intersect with the axial direction of the supply roller  70  at a position facing an outer circumferential surface on the upper side of the supply roller  70 . The seal blade  78  is disposed to be sloped down from the base end portion  78 A to the front end portion  78 B side. In the exemplary embodiment, the seal blade  78  is disposed such that a surface thereof on the side opposite to the liquid developer reservoir (not shown) which is formed in the chamber  132  is directed downward. 
     The nozzle  114  is disposed on the lower side from the seal blade  78  in the vertical direction such that the cleaning liquid L is supplied to the contact portion  79  from the upstream side of the contact portion  79  between the supply roller  70  and the seal blade  78  in the rotating direction of the supply roller  70 . In addition, a collection member  134 , in which the cleaning liquid L after flowing over the seal blade  78  due to gravity and farther flowing down along the outer circumferential surface of the supply roller  70  is collected, is provided below the supply roller  70 . 
     In the liquid developer supply device  130 , the cleaning liquid L is ejected through the nozzle  114  to the rotating supply roller  70 , and thereby the cleaning liquid L supplied to the outer circumferential surface of the supply roller  70  with the rotation of the supply roller  70  moves in a direction of arrow I. In this manner, the cleaning liquid L is supplied to the contact portion  79  between the supply roller  70  and the seal blade  78 . Therefore, the contact portion  79  between the supply roller  70  and the seal blade  78  is cleaned with the cleaning liquid L, and the attached substance such as the high-concentration liquid developer accumulated on the upstream side of the contact portion  79  between the supply roller  70  and the seal blade  78  is removed. Further, the cleaning liquid L supplied to the contact portion  79  between the supply roller  70  and the seal blade  78  is once diverted to the upper side of the seal blade  78  due to the fluid pressure of the cleaning liquid L in the direction of the arrow I and flows down to the outer circumferential surface side of the supply roller  70  along the seal blade  78  in a direction represented by arrow J due to gravity. Furthermore, the cleaning liquid L flows down along the outer circumferential surface of the supply roller  70  due to gravity and then, is collected in the collection member  134  disposed below the supply roller  70  in a direction represented by arrow K. 
     In the liquid developer supply device  130 , high-concentration liquid developer accumulated in the contact portion  79  between the supply roller  70  and the seal blade  78  is removed such that the high-concentration liquid developer enters into the inside of the chamber  72 , as compared with a configuration which does not include the supply unit that supplies the cleaning liquid to the contact portion between the supply roller and the seal blade such that the cleaning liquid flows down along the seal blade due to gravity. In addition, flexibility in selection of a position, at which the cleaning liquid L is supplied to the supply roller  70 , is improved, as compared with a configuration which does not include the nozzle through which the cleaning liquid is ejected to the supply roller. 
     Note that, in the first to sixth exemplary embodiments, the plural cells  70 A are provided in the outer circumferential surface of the supply roller  70 ; however, the invention is not limited to the configurations described above. For example, a configuration, in which plural grooves as an example of the recessed portion are provided on the outer circumferential surface of the supply roller  70 , may be employed. 
     In addition, in the fourth to sixth exemplary embodiments, the nozzle  114 , through which the cleaning liquid L is ejected to the supply roller  70 , is used; however, the invention is not limited to the configurations. For example, a cleaning liquid supply member such as a roller, which supplies the cleaning liquid L to the supply roller  70 , may be provided. 
     In addition, the second, third, or fifth exemplary embodiment has a configuration in which the brush that is in contact with the supply roller  70  rotates along with the rotation of the supply roller  70 ; however, the invention is not limited to this configuration. For example, the brush may be configured to be rotated and driven separately from the supply roller  70 , and the brush may be rotated in an opposite direction thereto at the position at which the brush is in contact with the supply roller  70 . 
     In addition, in the second and third exemplary embodiments, the brush is provided as an example of the replacement portion; however, the invention is not limited thereto. For example, a configuration, in which the brush and the ultrasonic oscillator provided in the cleaning vessel are together used, may be employed. 
     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.