JP5055147B2 - Liquid sample separation and extraction apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a liquid sample separation / extraction apparatus, and more particularly to a liquid sample separation / extraction apparatus and an image forming apparatus for separating a dispersoid and a dispersion medium from a liquid sample containing the dispersoid and the dispersion medium and extracting the dispersoid and the dispersion medium. .

  The liquid sample separation apparatus is an apparatus for separating and extracting a dispersoid and a dispersion medium from a liquid sample. For example, an image using a liquid developer containing a toner (dispersoid) and a carrier liquid (dispersion medium) is used. It is used in an image forming apparatus that performs formation. In this image forming apparatus, a residual developer that has not been used for development during an image forming operation is collected, toner and carrier liquid are separated using a liquid sample separation apparatus, and the carrier liquid is reused. is there.

In such an image forming apparatus, residual developer is collected. The collected liquid developer is passed through an open cell foam sandwiched between two electrodes to which different voltages are applied. At this time, the toner adheres to the open cell foam, and the carrier liquid passes through the open cell foam. In this way, after separating the toner and the carrier liquid, the carrier liquid is extracted (see Patent Document 1).
JP 2000-89573 A

  In the liquid sample separation and extraction apparatus described in Patent Document 1, if the open cell foam is clogged with toner, the liquid developer cannot be separated and extracted. For this reason, it is necessary to perform maintenance such as replacement of the open cell foam, which increases costs.

  An object of the present invention is to omit the maintenance work such as replacement of the open cell foam and to reduce the cost required for the maintenance.

  A liquid sample separation and extraction apparatus according to a first invention is a liquid sample separation and extraction apparatus for separating a dispersoid and a dispersion medium from a liquid sample containing the dispersoid and the dispersion medium, and extracting the dispersoid and the dispersion medium. A storage container, an electrode member, a blocking member, and a cleaning member are provided. The liquid storage container is a container that can store a liquid sample. An electrode member is a member arrange | positioned so that a liquid sample may be contacted in a liquid storage container. The dam member contacts the electrode member and dams the dispersion medium. The cleaning member scrapes off the dispersoid that has passed through the position where the electrode member and the blocking member are in contact with each other. A voltage is applied to the electrode member and the blocking member so as to generate an electric field that moves the dispersoid to the electrode member side between the electrode member and the blocking member. In addition, a voltage is applied to the electrode member and the liquid storage container so as to generate an electric field that moves the dispersoid to the electrode member side between the electrode member and the liquid storage container.

  In this liquid sample separation and extraction apparatus, a liquid sample containing a dispersoid and a dispersion medium is stored in a liquid storage container. At this time, a voltage is applied to the electrode member and the electrode member is rotated. Along with the rotation of the electrode member, the liquid sample is transported to a portion where the electrode member and the blocking member are in contact with each other. In this portion, the dispersion medium is blocked by the blocking member. The dispersoid conveyed along with the rotation of the electrode member without being dammed by the damming member is scraped off from the surface of the electrode member by the cleaning member.

  Here, since the liquid sample can be separated and extracted by the electrode member and the blocking member, it is possible to omit maintenance work and to reduce the cost required for the maintenance. Moreover, when a voltage is applied to the electrode member and the blocking member as described above, the dispersoid is attracted to the electrode member and adheres to the electrode member. Furthermore, when the voltage is applied to the electrode member and the liquid storage container as described above, the dispersoid moves away from the liquid storage container, that is, toward the electrode member, and adheres to the electrode member.

  A liquid sample separation / extraction apparatus according to a second aspect of the present invention is the liquid sample separation / extraction apparatus of the first aspect, wherein the liquid storage container is disposed at a position having the lowest height and is capable of discharging the dispersion medium. Has an exit.

  Here, it becomes easy to discharge the dispersion medium through the first discharge port.

  A liquid sample separation and extraction apparatus according to a third aspect of the present invention is the liquid sample separation and extraction apparatus of the first or second aspect, wherein the liquid storage container is disposed in the vicinity of the contact portion between the damming member and the electrode member. A second discharge port is further provided.

  Here, since the second discharge port is provided in the vicinity of the contact portion between the blocking member and the electrode member, the dispersion medium blocked by the blocking member can be easily discharged.

  A liquid sample separation / extraction apparatus according to a fourth aspect of the present invention is the liquid sample separation / extraction apparatus of any of the first to third aspects, wherein the dispersoid is a toner and the dispersion medium is a carrier liquid.

  Here, the toner and the carrier liquid can be separated and extracted from the liquid developer containing the toner and the carrier liquid.

  A liquid sample separation and extraction apparatus according to a fifth aspect of the present invention is the liquid sample separation and extraction apparatus according to any one of the first to fourth aspects of the present invention, wherein the liquid is axially outward at both axial ends of the damming member. A liquid movement preventing unit that prevents the movement is further provided.

  Here, the liquid can be prevented from moving outward in the axial direction of the blocking member by the liquid movement preventing portion. For this reason, it can be made difficult for the liquid to move from the portion other than between the electrode member and the blocking member to the cleaning member side.

  A liquid sample separation and extraction apparatus according to a sixth aspect of the present invention is the liquid sample separation and extraction apparatus according to any one of the first to fifth aspects, wherein the dam member is biased toward the electrode member.

  Here, the clearance gap between a dam member and an electrode member can be made small.

  An image forming apparatus according to a seventh aspect includes an image forming unit and a liquid developer separating and extracting device. The image forming unit forms an image on the medium using a liquid developer containing toner and carrier liquid. The liquid developer separating and extracting device separates toner and carrier liquid from the liquid developer and extracts toner and carrier liquid. The liquid developer separation / extraction apparatus includes a liquid container, an electrode member, a dam member, and a cleaning member. The liquid storage container is a container that can store a liquid developer. The electrode member is a member disposed in the liquid container so as to come into contact with the liquid developer. The dam member contacts the electrode member and dams the carrier liquid. The cleaning member scrapes off the toner that has passed through the position where the electrode member and the blocking member are in contact with each other. A voltage is applied to the electrode member and the blocking member so as to generate an electric field that moves the toner to the electrode member side between the electrode member and the blocking member. In addition, a voltage is applied to the electrode member and the liquid storage container so as to generate an electric field that moves the toner to the electrode member side between the electrode member and the liquid storage container.

  In this image forming apparatus, a liquid developer containing toner and carrier liquid is stored in a liquid storage container. At this time, a voltage is applied to the electrode member and the electrode member is rotated. With the rotation of the electrode member, the liquid developer is conveyed to a portion where the electrode member and the blocking member are in contact with each other. Then, the carrier liquid is blocked by the blocking member at this portion. The toner that is conveyed by the rotation of the electrode member without being blocked by the blocking member is scraped off from the surface of the electrode member by the cleaning member.

  Here, since the liquid developer can be separated and extracted by the electrode member and the blocking member, the maintenance work can be omitted and the cost required for the maintenance can be reduced. In addition, as described above, when a voltage is applied to the electrode member and the blocking member, toner is attracted to the electrode member and adheres to the electrode member. Further, when the voltage is applied to the electrode member and the liquid container as described above, the toner moves away from the liquid container, that is, toward the electrode member, and adheres to the electrode member.

  In the present invention, it is possible to omit maintenance work such as replacement of the open cell foam and to reduce the cost required for the maintenance.

<First Embodiment>
Hereinafter, a first embodiment of an image forming apparatus according to the present invention will be described with reference to the drawings. For convenience of explanation, the position and size of the members are drawn with emphasis as appropriate in the drawings. In the following embodiments, a printer will be described as an example of the image forming apparatus of the present invention, but the present invention is not limited to this. That is, the image forming apparatus of the present invention only needs to include an image forming unit, and may be a so-called multi-function peripheral (MFP) having a function as a copying machine or a facsimile machine or only a copying function. Specific configurations of these members described below, other members, and the like can be appropriately changed.

1. Overall Configuration A schematic configuration of a color printer 1 as an image forming apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a front view showing a main configuration of the color printer 1.

  The color printer 1 includes a tandem image forming unit 2 that forms a toner image based on image data, a paper storage unit 3 that stores paper, and a toner image formed by the image forming unit 2 on a sheet as a medium. A secondary transfer unit 4 that transfers the toner image onto the sheet, a fixing unit 5 that fixes the transferred toner image on the sheet, a discharge unit 6 that discharges the fixed sheet, and a sheet from the sheet storage unit 3 to the discharge unit 6. Are mainly provided with a sheet conveying section 7 for conveying the liquid and a liquid developer circulating device 27 (see FIG. 2). The liquid developer circulating device 27 will be described in detail later.

  The image forming unit 2 includes an intermediate transfer belt 21, a cleaning unit 22 for the intermediate transfer belt 21, and an image forming unit corresponding to each of yellow (Y), magenta (M), cyan (C), and black (Bk). FY, FM, FC, and FB.

  The intermediate transfer belt 21 is an endless belt-like member, that is, a loop-like member, and is driven to circulate clockwise as indicated by an arrow in FIG. Hereinafter, the surface facing outward in the circulation drive is referred to as a front surface, and the other surface is referred to as a back surface.

  Four image forming units FY, FM, FC, and FB are arranged in the vicinity of the intermediate transfer belt 21 between the cleaning unit 22 and the secondary transfer unit 4 of the intermediate transfer belt 21. Note that the order of arrangement of the image forming units FY, FM, FC, and FB is not limited to this, but this arrangement is preferable in consideration of the influence of the color mixture on the completed image. The image forming units FY, FM, FC, and FB include a photosensitive drum 10, a charger 11, an LED exposure device 12, a developing device 14, a primary transfer roller 20, a cleaning device 26, and a charge removal device 13. And a carrier liquid removing roller 30. Further, among the image forming units, the image forming unit FB located closest to the secondary transfer unit 4 is not provided with the carrier liquid removal roller 30, but the other configurations are the same.

  The photosensitive drum 10 is a cylindrical member, and can carry a toner image including toner charged on its surface (charged positively in this embodiment). The photosensitive drum 10 is a member that can rotate counterclockwise in FIG.

  The charger 11 is a device that can uniformly charge the surface of the photosensitive drum 10.

  The LED exposure device 12 has an LED light source, and can irradiate the charged surface of the photosensitive drum 10 with light corresponding to image data to form an electrostatic latent image on the surface of the photosensitive drum 10.

  The developing device 14 holds a liquid developer containing toner (dispersoid) and a liquid carrier (dispersion medium: hereinafter referred to as carrier liquid) so as to face the electrostatic latent image, thereby forming an electrostatic latent image. Toner can be applied and the electrostatic latent image can be developed as a toner image. The developing device 14 includes a developing container 40, a developing roller 40a, a supply roller 40b, a support roller 40c, a development cleaning blade 40f, and a supply roller doctor blade 40g.

  The developer container 40 is a member for receiving the liquid developer supplied from the liquid developer supply device 278 and dropped from the supply roller 40b and the support roller 40c.

  The support roller 40c is for supplying a liquid developer to the developing roller 40a. The support roller 40c can rotate counterclockwise in FIG. 1, and a supply roller 40b that can rotate clockwise in FIG. 1 is disposed so as to be in contact with the support roller 40c. In addition, a supply roller doctor blade 40g that contacts the supply roller 40b and regulates the developer layer thickness on the surface of the supply roller 40b is provided. The supply roller doctor blade 40g regulates the developer layer thickness on the surface of the supply roller 40b to a predetermined amount. A developing roller 40a that can rotate clockwise in FIG. 1 is disposed so as to be in contact with the supply roller 40b, and developer is supplied to the surface of the developing roller 40a from the supply roller 40b. Since the developer layer thickness of the supply roller 40b is regulated to a predetermined value, the developer layer thickness formed on the surface of the developing roller 40a is also kept at the predetermined value. Toner is supplied from the developing roller 40 a to the surface of the photosensitive drum 10. A toner image corresponding to the image data instructed to be formed is formed on the surface of the photosensitive drum 10 by the difference in potential between the electrostatic latent image on the surface of the photosensitive drum 10 and the developing bias applied to the developing roller 40a (development). Operation).

  The developer on the surface of the developing roller 40a that has completed the developing operation on the photosensitive drum 10 is removed by the developing cleaning blade 40f, flows down along the surface of the developing cleaning blade 40f, and the liquid developer circulating device 27 (FIG. 2). The residual developer tank 271 (see FIG. 2).

  The developing device 14 is provided with a liquid developer supply device 278, and the liquid developer is supplied from the liquid developer supply device 278 onto the support roller 40c near the contact portion between the supply roller 40b and the support roller 40c. Is done. Further, the liquid developer received in the developing container 40 is discharged to a residual developer tank 271 (see FIG. 2) of the liquid developer circulating device 27.

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

  The cleaning device 26 is a device for cleaning toner remaining without being transferred from the photosensitive drum 10 to the intermediate transfer belt 21, and includes a residual toner conveying screw 261 and a cleaning blade 262. The residual toner conveying screw 261 is a member for conveying the residual toner, which is scraped by the cleaning blade 262 and stored in the cleaning device 26, to the outside of the cleaning device 26, and is disposed in the cleaning device 26. . The cleaning blade 262 is a member for scraping off the toner remaining on the surface of the photosensitive drum 10 and is a plate-like member extending in the direction in which the photosensitive drum 10 extends.

  The cleaning blade 262 has an end that is in sliding contact with the surface of the photosensitive drum 10, and scrapes off toner remaining on the photosensitive drum 10 as the photosensitive drum 10 rotates.

  The neutralization device 13 includes a light source. After the developer is removed by the cleaning blade 262, the surface of the photosensitive drum 10 is neutralized by light from the light source to prepare for the next image formation.

  The carrier liquid removal roller 30 is a substantially cylindrical member that can rotate in the same direction as the photosensitive drum 10 around a rotational axis parallel to the rotational axis of the photosensitive drum 10. The carrier liquid removing roller 30 is disposed on the side where the secondary transfer unit 4 is disposed with respect to the position where the photosensitive drum 10 and the intermediate transfer belt 21 are in contact with each other. It is a member that removes liquid.

  The paper storage unit 3 is a part for storing paper for fixing a toner image, and is disposed at the lower part of the color printer 1. The paper storage unit 3 has a paper feed cassette that stores paper.

  The secondary transfer unit 4 is a part that transfers the toner image formed on the intermediate transfer belt 21 to a sheet, and is disposed opposite to the support roller 41 that supports the intermediate transfer belt 21 and the support roller 41. And a secondary transfer roller 42.

  The fixing unit 5 is a part for fixing the toner image on the sheet, and is disposed on the upper side of the secondary transfer unit 4. The fixing unit 5 includes a heating roller 51 that is in contact with the toner image transferred to the sheet, and a pressure roller 52 that is disposed to face the heating roller 51.

  The discharge unit 6 is a portion from which the paper on which the toner image has been fixed by the fixing unit 5 is discharged, and is disposed at the top of the color printer 1.

  The paper transport unit 7 is a part that transports paper from the paper storage unit 3 to the secondary transfer unit 4, the fixing unit 5, and the discharge unit 6.

2. Liquid developer circulating device 2-1. Overall Configuration of Liquid Developer Circulating Device FIG. 2 shows an outline of the entire liquid developer circulating device 27. The liquid developer circulating device 27 includes a developer (a mixture of toner and carrier liquid) scraped from the surface of the developing roller 40a by the developing cleaning blade 40f after supplying the toner to the photosensitive drum 10, and a supply roller 40b. Is a device that circulates and reuses the developer that has not been supplied to the developing roller 40a and the developer that has been transferred to the intermediate transfer belt 21 and then scraped off from the photosensitive drum 10 by the cleaning device 26. The liquid developer circulation device 27 includes a residual developer tank 271, a developer container 272, a solid content detection device 273, a carrier tank 274, a toner tank 275, a developer reserve tank 277, and liquid development. A developer supplying device 278, a residual developer collecting container 279, a liquid developer separating and extracting device 28, and a plurality of pumps P1 to P11 are provided.

  The residual developer tank 271 is connected to the developing device 14 via the pipe 31 and can store the developer scraped off from the surface of the developing roller 40a by the developing cleaning blade 40f after supplying the toner to the photosensitive drum 10. It is a tank. One pump P1 is attached between the developing device 14 and the residual developer tank 271 so that the residual developer scraped from the surface of the developing roller 40a is moved to the residual developer tank 271. It has become. The residual developer tank 271 is connected to the bottom of the developing device 14 via a pipe 32, and a pump P <b> 5 is connected to the pipe 32. The pump P5 sends the developer from the developer container 40 to the residual developer tank 271.

  The developer storage container 272 is connected to the residual developer tank 271 and is a part for preparing the developer to be replenished to the developing device 14 (toner density adjustment). The developer container 272 is connected to the residual developer tank 271 via a pipe 33, and a pump P <b> 2 is connected to the pipe 33.

  The solid content concentration detection device 273 is a device for detecting the toner concentration of the liquid developer in the developer storage container 272, and is connected to an annular pipe 34 connected to the developer storage container 272. Yes. A pump P4 is attached on the upstream side of the solid content concentration detecting device 273 of the annular pipe 34.

  The carrier tank 274 stores a carrier liquid for reducing the toner concentration in the developer storage container 272. The carrier tank 274 is connected to the developer container 272 by a pipe 35 to which a pump P3 is attached.

  The toner tank 275 stores a liquid developer having a high toner concentration for increasing the toner concentration in the developer container 272, and the toner concentration of the liquid developer in the toner tank 275 is used in the developing device 14. It is higher than the toner concentration of the liquid developer. The toner tank 275 is connected to the developer container 272 by a pipe 36 to which a pump P8 is attached.

  The developer reserve tank 277 stores a liquid developer to be supplied to the developing device 14, and is connected to the developer storage container 272 via a pipe 37 to which a pump P6 is attached. Further, it is connected to the liquid developer supply device 278 via a pipe 38 to which a pump P7 is attached.

  The liquid developer supply device 278 is a device for supplying the developer to the developing device 14.

  The residual developer recovery container 279 is a container for temporarily storing the developer removed from the photosensitive drum 10 by the cleaning device 26.

2-2. Configuration of Liquid Developer Separation and Extraction Device As shown in FIGS. 3 and 4, the liquid developer separation and extraction device 28 separates the liquid developer into toner and carrier liquid, and extracts the carrier liquid and toner separately. Which is disposed in the middle of pipes 39 and 43 connecting the residual developer collecting container 279 and the carrier tank 274. The liquid developer separation and extraction device 28 includes a liquid container 281, an electrode roller 282 (electrode member), a damming roller 283 (damming member), a blade member 284 (cleaning member), and a voltage applying device 285 (FIG. 2), a liquid movement preventing unit 286 (see FIG. 9), and an urging mechanism 287 (see FIG. 9).

  The liquid storage container 281 is a container that can store a liquid developer, and at least the surface of the part that stores the liquid is formed of a conductive material. Further, the portion of the liquid container 281 formed of a conductive material is connected to the voltage application device 285, and includes a first container 281a and a second container 281b. As shown in FIG. 5, the first container 281 a has a shape that is recessed downward so as to accommodate a lower half of a roller portion 282 b (described later) of the electrode roller 282, and is a portion of the portion that accommodates the electrode roller 282. The inner surface has a curved shape so as to maintain a predetermined distance from the surface of the roller portion 282b. As shown in FIGS. 3 and 4, the first container 281a includes a supply port 281r for supplying the liquid developer to the liquid container 281 at a position facing the lower part of the electrode roller 282, and a substantially longitudinal direction. A first discharge port 281c is provided at the center. The supply port 281r ejects the liquid developer near the lowermost portion of the first container 281a when the electrode roller 282 is stopped. Further, as shown in FIG. 5, the first container 281 a is provided with a plurality of jet outlets 281 p through which the liquid developer can be jetted in equal intervals in the longitudinal direction. In FIG. 5, only one jet outlet 281p is denoted by a reference numeral, and the other is omitted. The plurality of jet outlets 281p are connected to the supply port 281r inside the first container 281a. In addition, a tray cover 281d having an arcuate recess 281f is disposed at both longitudinal ends of the first container 281a. The arc-shaped concave portion 281f faces a bearing (not shown) that rotatably supports the rotating shaft 282a of the electrode roller 282 with a small interval. The tray cover 281d prevents liquid developer remaining in the first container 281a from spilling from both ends of the first container 281a when the first container 281a is removed from the electrode roller 282 for maintenance or the like. Here, the upper end portion of the first discharge port 281c is accurately positioned so as not to form a step between the inner surface of the portion of the first container 281a that houses the electrode roller 282. The second container 281b is detachable from the first container 281a, and has an inner surface curved along the electrode roller 282 when disposed so as to face the electrode roller 282. The first container 281a In the state of being connected to, the first container 281a and about 75% of the electrode roller 282 are covered. The second container 281b has a second discharge port 281e located in the vicinity of the contact portion between the electrode roller 282 and the weir roller 283. Note that the second discharge port 281e is not always necessary, and the second discharge port 281e is collected in the vicinity of the contact portion between the electrode roller 282 and the weir roller 283 in order to efficiently extract the carrier liquid from the liquid developer separation and extraction device 28 without taking time. It is provided to suck out the carrier liquid. Even if the second discharge port 281e is not provided, it takes more time than the case where the second discharge port 281e is provided, but the carrier accumulated near the contact portion between the electrode roller 282 and the weir roller 283. The liquid also flows down the liquid storage container 281 with time and is discharged from the first discharge port 281c.

  The electrode roller 282 is a pipe-shaped member made of metal (specifically, SUS), and its surface roughness is, for example, Ry6.3 (JIS B0601-1994). The electrode roller 282 is connected to a voltage application device 285, and a voltage is applied by the voltage application device 285. Further, as shown in FIG. 6, the electrode roller 282 includes a rotating shaft 282a and a roller portion 282b, a shaft support member 282c, a seal packing 282d, and a liquid leakage prevention member 282e. Here, FIGS. 7 and 8 are cross-sectional views showing in detail the vicinity of the shaft support member 282c. The shaft support member 282c is an annular member, and is disposed at both ends of the roller portion 282b in the axial direction. The diameter of the shaft support member 282c and the diameter of the roller portion 282b of the electrode roller 282 are the same. Further, the shaft support member 282c has six protrusions 282f formed on the outer periphery at equal intervals. The protrusion 282f plays a role of contacting the liquid container 281 and positioning the liquid container 281. The first container 281a is pressed from below by a spring as a biasing member (not shown), and the pressing force is, for example, 2 kg. For this reason, the positional relationship between the first container 281a and the shaft support member 282c does not shift. The height of the projection 282f is 0.5 mm, and the distance between the outer peripheral surface of the electrode roller 282 and the wall surface of the liquid container 281 is maintained at 0.5 mm by the projection 282f. This distance does not need to be constant, and may be changed within a range that satisfies conditions such as separation efficiency of the liquid developer and leakage due to applied voltage. For example, the interval corresponding to the lowermost portion of the electrode roller 282 may be 0.5 mm, and the uppermost interval where the electrode roller 282 and the second container 281b face each other may be 0.3 mm. Further, the shaft support member 282c is formed with a pair of wall-like portions 282i protruding outward in the axial direction, and a bearing of an unillustrated electrode roller 282 (not shown) that rotatably supports the rotating shaft 282a of the electrode roller 282. To be inserted. For this reason, the shaft support member 282c is fixed. Therefore, since the position of the protrusion 282f of the electrode roller 282 shown in FIG. 3 is fixed, the distance between the surface of the roller portion 282b of the electrode roller 282 and the inner peripheral surface of the liquid container 281 is set to a predetermined value (this embodiment). In the example, it can be kept at 0.5 mm). Further, even when the predetermined value varies depending on the location as described above, the interval at each position can be kept constant. The rotating shaft 282a of the electrode roller 282 is driven by a driving source (not shown). An annular groove 282g is provided on the outer peripheral surface of the shaft support member 282c, and a recess 282h in which the seal packing 282d can be disposed is formed on the end surface facing the wall surface of the liquid container 281. The seal packing 282d is disposed on the concave portion 282h of the shaft support member 282c, that is, on the inner peripheral side of the shaft support member 282c and on the outer peripheral side of the rotary shaft 282a, and prevents the liquid from moving outward in the axial direction. ing. The liquid leakage prevention member 282e is an annular elastic member, and is disposed in the groove 282g of the shaft support member 282c. Further, the liquid leakage prevention member 282e is disposed in proximity to both ends of the roller portion 282b. The liquid container 281 and the weir roller 283 are positioned with respect to the electrode roller 282, and the electrode roller 282 serves as a position reference for these members.

  The dam roller 283 is disposed so as to contact the roller portion 282b, and at least the surface thereof is made of an elastic member subjected to conductive treatment (specifically, a SUS pipe is covered with urethane rubber whose surface is subjected to conductive treatment). E) Roller. The dam roller 283 rotates following the electrode roller 282. The dam roller 283 is elastically deformed by being urged toward the electrode roller 282 by an urging mechanism 287 (see FIG. 9). Furthermore, as shown in FIG. 9, pulleys 283 a that can rotate relative to the dam roller 283 are disposed at both ends of the dam roller 283 in the axial direction. It should be noted that the electrode roller 282 has a minus 500 V, dam roller, so that an electric field is generated between the electrode roller 282 and the dam roller 283 so that the positively charged toner moves from the dam roller 283 to the electrode roller 282. A positive 500 V is applied to 283. Similarly, 500 V is applied to the liquid container 281 so that an electric field is generated between the electrode roller 282 and the liquid container 281 so that the toner moves from the liquid container 281 to the electrode roller 282.

  The outer diameter of the roller portion 282b of the electrode roller 282 is larger than the outer diameter of the dam roller 283. For example, the outer diameter of the dam roller 283 is 20 mm with respect to the outer diameter Φ 40 mm of the roller portion 282b. The roller portion 282b is longer in the axial direction than the dam roller 283. For example, the axial length of the roller portion 282b is 326 mm, whereas the axial length of the dam roller 283 is 310 mm. The pressing force of the dam roller 283 to the electrode roller 282 by the urging mechanism 287 is 2 kg, for example, and the nip depth of the dam roller 283 is 0.5 mm, for example.

  The blade member 284 as a cleaning member is downstream in the rotation direction of the electrode roller 282 with respect to the position where the electrode roller 282 and the weir roller 283 are in contact, and upstream of the supply port 281r provided in the first container 281a. 3 is a plate-like member that is arranged on the left side, that is, on the left side in FIG.

  The voltage application device 285 is connected to the liquid container 281, the electrode roller 282, and the dam roller 283 so that a voltage can be applied.

  As shown in FIG. 9, the liquid movement prevention unit 286 is a member disposed at both ends in the axial direction of the dam roller 283 and the roller unit 282b, and has a circular hole in which the shaft of the dam roller 283 can be disposed. And a portion having the same curvature as the curvature of the roller portion 282b.

  The urging mechanism 287 is a mechanism for urging the dam roller 283 toward the electrode roller 282, and is arranged at one end of a coil spring 287a fixed to an outer frame (not shown) and the other end of the coil spring 287a. And a roller shaft support member 287b capable of supporting the shaft of the dam roller 283. For this purpose, the shaft of the weir roller 283 is biased by the coil spring 287a via the roller shaft support member 287b.

  As shown in FIG. 2, the liquid developer separation and extraction device 28 is connected to a first flow path 86, a second flow path 87, and a third flow path 88. The first flow path 86 is a flow path for sending the carrier liquid discharged from the first discharge port 281c to the carrier tank 274. The second flow path 87 is a flow path for joining the carrier liquid discharged from the second discharge port 281e with the carrier liquid discharged from the first discharge port 281c. The third flow path 88 is a flow path for sending the carrier liquid discharged from the first discharge port 281 c and the second discharge port 281 e to the carrier liquid concentration measuring device 81. A first opening / closing valve V1 is provided at the outlet of the first discharge port 281c, and a pump P10 is provided in the first flow path 86. A second on-off valve V2 is provided at the outlet of the second discharge port 281e. The third flow path 88 is provided with a pump P11 and a third on-off valve V3. The third flow path 88 merges with a pipe 39 that connects the residual developer recovery container 279 and the liquid developer separation and extraction device 28, and a fourth on-off valve V4 is provided upstream of the merged portion. . Further, a fifth on-off valve V5 is provided on the downstream side of the joining portion of the first flow path 86 and the second flow path 87. When separation processing is performed in the liquid developer separation and extraction device 28, the flow of the liquid developer and the extracted carrier liquid is switched by controlling these on-off valves and pumps.

3. Operation 3-1. Image Forming Operation Next, the image forming operation of the wet color printer 1 will be described.

  Upon receiving an image formation instruction from a personal computer (PC) connected to the wet color printer 1, the color printer 1 converts the toner images of the respective colors corresponding to the image data received with the creation instruction into image forming units FY, FM, FC. , FB. Specifically, an electrostatic latent image based on the image data is formed on the photosensitive drum 10, and toner is supplied from the developing device 14 to the electrostatic latent image to form a toner image. The toner images formed by the image forming units FY, FM, FC, and FB in this way are transferred to the intermediate transfer belt 21 and are superimposed on the intermediate transfer belt 21 to form a color toner image.

  In synchronization with the formation of the color toner image, the paper stored in the paper storage unit 3 is taken out from the paper storage unit 3 one by one by a paper feeding device (not shown), and is transported along the paper transport unit 7. Then, the sheet is sent to the secondary transfer unit 4 in synchronization with the primary transfer to the intermediate transfer belt 21, and the color toner image on the intermediate transfer belt 21 is secondarily transferred to the sheet by the secondary transfer unit 4. The sheet on which the color toner image is transferred is further conveyed to the fixing unit 5 where the color toner image is fixed on the sheet by heat and pressure. Further, the paper is discharged out of the wet color printer 1 by the discharge unit 6. The toner remaining on the intermediate transfer belt 21 after the secondary transfer is removed from the intermediate transfer belt 21 by the cleaning unit 22 of the intermediate transfer belt 21.

3-2. Next, an operation of supplying the liquid developer to the developing device 14, that is, a circulation operation of the liquid developer will be described.

  The liquid developer remaining on the developing roller 40a without being supplied to the photosensitive drum 10 during the image forming operation is scraped off by the developing cleaning blade 40f and collected in the residual developer tank 271 via the pipe 31. Further, the liquid developer received in the developing container 40 is also sent to the residual developer tank 271 through the pipe 32 by the pump P5. When the amount of developer in the developer container 272 is exhausted, the residual developer is supplied from the residual developer tank 271 to the developer container 272 via the pipe 33 by the pump P2. At this time, the developer remaining on the photosensitive drum 10 without being developed is scraped off by the cleaning blade 262 and stored in the residual developer collection container 279.

  The residual developer recovered in the residual developer recovery container 279 is conveyed to the liquid developer separation / extraction device 28 via the pipe 39 by the pump P9 every predetermined amount (see arrow A9 in FIG. 2), and separated and extracted by the liquid developer. In the device 28, the toner and the carrier liquid are separated and extracted. The carrier liquid extracted in the liquid developer separating and extracting device 28 is sent to the carrier tank 274 through the pipe 43 by the pump P10. The separation process of the toner and the carrier liquid in the liquid developer separation / extraction apparatus 28 will be described in detail later.

  On the other hand, the toner concentration of the liquid developer in the developer container 272 is detected by the solid concentration detector 273, and the concentration of the liquid developer in the developer container 272 is adjusted. Here, when the toner concentration is high, the carrier liquid is supplied from the carrier tank 274 to the developer container 272 via the pipe 35 by the pump P3. When the toner concentration is low, a liquid developer having a higher toner concentration than the liquid developer used in the developing device 14 is supplied from the toner tank 275 to the developer storage container 272 via the pipe 36 by the pump P8.

  Then, the liquid developer whose density is adjusted from the developer container 272 to the developer reserve tank 277 as needed is supplied via the pipe 37 by the pump P6, and the liquid developer stored in the developer reserve tank 277 is supplied. Is sent to the liquid developer supply device 278 via the pipe 38 by the pump P7, and is supplied from the liquid developer supply device 278 to the development device 14.

3-3. Separation Operation of Toner and Carrier Liquid in Liquid Developer Separation / Extraction Device Next, the separation operation of toner and carrier liquid in the liquid developer separation / extraction device 28 will be described.

  First, a predetermined amount of residual developer is sent to the liquid developer separating and extracting device 28 by the pump P9, and then the pump P9 is stopped.

  Next, separation processing of the toner and the carrier liquid is performed in the liquid developer separation / extraction device 28. During this separation process, the first on-off valve V1, the second on-off valve V2, and the fourth on-off valve V4 are closed (see FIG. 2). At this time, the voltage application device 285 causes the liquid container 281, the dam roller 283, and the electrode roller 282 to pass between the liquid container 281 and the electrode roller 282, and between the dam roller 283 and the electrode roller 282, respectively. A voltage is applied to generate an electric field that causes the toner to move in the direction of the electrode roller. That is, a voltage having the same polarity as the toner is applied to the liquid container 281 and the weir roller 283, and a voltage having a polarity opposite to the charging polarity of the toner is applied to the electrode roller 282. For this reason, in the liquid developer stored in the liquid storage container 281, the toner moves to the electrode roller 282 side, and the carrier liquid having no charge remains on the liquid storage container 281 side. Further, the electrode roller 282 rotates counterclockwise in FIG. 3 (see arrow A13), and the dam roller 283 rotates clockwise in FIG. 3 (see arrow A14). The rotation speed of the electrode roller 282 is, for example, 5 rpm. In this case, the rotation speed of the dam roller 283 is 10 rpm. As the electrode roller 282 and the weir roller 283 rotate, the liquid developer is conveyed to the contact portion between the electrode roller 282 and the weir roller 283. The toner is electrically attracted to the electrode roller 282 and a voltage having the same polarity as that of the toner is applied to the dam roller 283, thereby receiving an electric repulsive force from the dam roller 283. As a result, the toner is electrically biased in the direction away from the weir roller 283, that is, the electrode roller 282 side. In addition, since the voltage having the same polarity as that of the toner is applied to the liquid container 281, the toner receives an electric repulsive force from the liquid container 281 and is electrically biased toward the electrode roller 282. Application of such a voltage prevents toner from adhering to the weir roller 283 and the liquid container 281. In this way, the toner is electrically attached to the electrode roller 282. For this reason, the toner attached to the electrode roller 282 passes between the electrode roller 282 and the weir roller 283. The toner adhering to the electrode roller 282 is scraped off by the blade member 284. The toner scraped off by the blade member 284 is collected from the blade member 284 to a waste toner container (not shown) by a sweep roller and a screw portion (not shown). Here, the toner is discarded, but may be reused.

  When a predetermined time elapses after the separation processing of the toner and the carrier liquid is started in the liquid developer separation and extraction device 28, the separated carrier liquid is extracted from the liquid storage container 281 and sent to the carrier liquid concentration measurement device 81. (See arrow A10 in FIG. 2). In this case, the fifth on-off valve V5 and the fourth on-off valve V4 are closed, and the first on-off valve V1, the second on-off valve V2, and the third on-off valve V3 are opened. Then, the pump P11 is driven, and the carrier liquid is sent from the liquid developer separation and extraction device 28 to the carrier liquid concentration measuring device 81. This carrier liquid is returned to the upstream side of the liquid developer separation and extraction device 28 after the concentration is measured by the carrier liquid concentration measuring device 81.

  When it is confirmed that the toner concentration in the carrier liquid measured by the carrier liquid concentration measuring device 81 is not more than a predetermined value (for example, 0.001% or less), the carrier liquid in the liquid container 281 is pumped. By P10, it discharges | emits from the 1st discharge port 281c and the 2nd discharge port 281e, and is conveyed to the carrier tank 274 (refer arrow A11 of FIG. 2). Here, the first on-off valve V1, the second on-off valve V2, and the fifth on-off valve V5 are opened, and the third on-off valve V3 and the fourth on-off valve V4 are closed. Moreover, the pump P11 is stopped.

  When the transport of the carrier liquid from the liquid developer separation / extraction device 28 is completed, the pump P10 is stopped and the fourth on-off valve V4 is opened, and a predetermined amount of residual developer is again separated by the liquid developer separation by the pump P9. It is transported to the extraction device 28 and the next separation process is performed. Such an operation is repeated.

  In this liquid developer separation and extraction device 28, 3.7 g of carrier liquid can be extracted from 5 g of liquid developer (containing 4.3 g of carrier liquid and 0.7 g of toner). In addition, the time required for one separation process is, for example, 75 seconds, and in this case, it is possible to cope with a sheet feeding speed of 227 mm / s.

  Further, at the time of maintenance or the like, the first container 281a and the second container 281b of the liquid container 281 are configured so that a biasing force from a biasing mechanism 287 or a biasing means (not shown) is not applied to the liquid container 281. After releasing the connection, the liquid container 281 is removed from the electrode roller 282.

  Here, since the liquid developer can be separated and extracted by the electrode roller 282 and the weir roller 283, maintenance work can be saved and the cost required for the maintenance can be reduced.

  In addition, since the protrusion 282f formed on the outer peripheral side of the shaft support member 282c is in contact with the liquid container 281, it is easy to keep the distance between the electrode roller 282 and the wall surface of the liquid container 281 constant. be able to. Further, since the entire outer peripheral surface of the shaft support member 282c is not in contact with the liquid container 281, the shaft support member 282c is less likely to stick to the wall surface of the liquid container 281, and the liquid container 281 can be easily removed from the electrode roller 282. be able to. Further, the liquid leakage prevention member 282e and the seal packing 282d can prevent liquid from leaking outward in the axial direction of the rotation shaft 282a of the electrode roller 282.

Second Embodiment
10 and 11 show the configuration of a liquid developer separation / extraction apparatus 300 according to the second embodiment of the present invention. The other configuration of the image forming apparatus provided with the liquid developer separation and extraction apparatus 300 is the same as that of the color printer 1 according to the first embodiment. The liquid developer separation and extraction apparatus 300 includes an electrode roller 382 (see FIG. 18), a liquid container 380, a weir roller 383, a blade member 384 as a cleaning member, and a voltage application device 285 (see FIG. 2). The liquid movement preventing unit 386 (see FIG. 19) and the urging mechanism 387 (see FIG. 19) are provided.

  The electrode roller 382 is a metallic member and is connected to the voltage application device 285. Further, as shown in FIG. 18, the electrode roller 382 includes a rotating shaft 382a and a roller portion 382b, a shaft support member 382c, and a seal packing 382d. The shaft support member 382c is an annular member and is disposed at both axial ends of the roller portion 382b. The diameter of the shaft support member 382c and the diameter of the roller portion 382b are the same. The shaft support member 382c has six protrusions 382e formed on the outer periphery. The protrusion 382e contacts the liquid container 380 and plays a role of positioning the liquid container 380. Further, the shaft support member 382c is formed with a pair of wall-like portions 382f protruding outward in the axial direction on the inner peripheral side, and a stationary electrode (not shown) that rotatably supports the rotating shaft 382a of the electrode roller 382. The roller 382 is inserted into the bearing. For this reason, the shaft support member 382c is fixed. The shaft support member 382c can be provided with a seal packing 382d on the end surface of the electrode roller 382 that does not face the roller portion 382b. The seal packing 382d prevents the liquid from moving outward in the axial direction.

  The liquid storage container 380 is a container that can store a liquid developer composed of toner (dispersion medium) and carrier liquid (dispersoid), and is formed of a conductive material. In addition, the liquid storage container 380 is connected to the voltage application device 285, and includes a first container 380a and a second container 380b.

  As shown in FIGS. 12 to 14, the first container 380 a is a substantially rectangular parallelepiped member in which a semi-cylindrical recess 380 k is formed so as to be able to maintain a predetermined distance from a part of the surface of the electrode roller 382. The first discharge opening 380c, the ejection opening 380d, the first liquid transport passage 380i, and the supply port 380f are provided. In addition, tray covers 380ad having arcuate concave portions are disposed at both ends in the longitudinal direction of the first container 380a. The arc-shaped concave portion of the tray cover 380ad faces a bearing (not shown) that rotatably holds the rotating shaft 382a of the electrode roller 382 with a small interval. As shown in FIG. 13, the tray cover 380ad is screwed to the first container 380a by a screw 380S, and the liquid developer remaining in the first container 380a when the first container 380a is removed from the electrode roller 382. This is a member that prevents leakage of water to the outside.

  The first discharge opening 380c is a portion capable of discharging the liquid developer and the carrier liquid, is substantially the center in the longitudinal direction of the first container 380a, and is provided at the lowest position of the recess 380k. Therefore, when recovering the extracted carrier liquid, the carrier liquid flows into the first discharge opening 380c by gravity, so that the carrier liquid can be recovered smoothly. The first discharge opening 380c is a passage that is connected to the outside through a first discharge port 380r provided on the surface of the first container 380a and allows liquid to pass through. Here, the first discharge opening 380c and the first discharge port 380r are provided in the first liquid discharge member 380u that is separate from the first container 380a, and as shown in FIG. It is attached to the first container 380a by screws 380s. The end of the first discharge opening 380c on the concave portion 380k side of the first container 380a is accurately positioned so that no step is formed between the first discharge opening 380c and the concave portion 380k. In addition, the outer diameter of the portion of the first liquid discharge member 380u inserted into the first container 380a is slightly smaller than the inner diameter of the corresponding portion of the first container 380a. Therefore, there is a slight gap between them. In order to prevent the extracted carrier liquid from entering the gap between the first liquid discharge member 380u and the first container 380a and leaking from the first container 380a, the bottom surface of the first container 380a and the first liquid discharge member 380u A liquid leakage prevention member 380z is provided at the portion where the contact is made.

  The ejection openings 380d are arranged at equal intervals along the longitudinal direction of the first container 380a and the axial direction of the electrode roller 382, and are portions where the liquid developer can be ejected toward the electrode roller 382. . Since the large number of ejection openings 380d are arranged in the axial direction of the electrode roller 382, the liquid developer can be quickly distributed in the axial direction of the electrode roller 382. Each ejection opening 380d is connected to the first liquid transport passage 380i.

  The first liquid transport passage 380i is a passage for transporting the liquid developer to each ejection opening 380d, and is provided along the longitudinal direction of the first container 380a.

  The supply port 380f is a portion for supplying the liquid developer to the recess 380k facing the electrode roller 382 of the first container 380a, and is connected to the first liquid transport passage 380i. Here, as shown in FIG. 13, the supply port 380f and the first liquid transport passage 380i are provided in a liquid supply member 380t separate from the first container 380a. Further, the liquid supply member 380t is provided with a concave liquid leakage prevention member mounting portion, and a liquid leakage prevention member 380x is provided over the entire contact portion between the first container 380a and the liquid supply member 380t (see FIG. 14). . The liquid supply member 380t is attached to the first container 380a with a screw 380s (see FIG. 13). In FIG. 14, the cross section of the recess 380k of the first container 380a is uneven, but the first liquid transport passage 380i is provided in a zigzag avoiding the mounting hole of the screw 380s, and FIG. This is because it is a cross-sectional view of the first container 380a along 380i.

  The second container 380b can be attached to and detached from the first container 380a, and when the second container 380b is disposed with respect to the electrode roller 382, a concave portion 381k that is curved along the electrode roller 382 is formed, and is connected to the first container 380a. In this state, about 75% of the electrode roller 382 is covered together with the first container 380a. Further, as shown in FIGS. 15, 16, and 17, the second container 380b includes a second discharge opening 380e, a second liquid transfer passage 380g, and a second discharge port 380h. The second discharge openings 380e are portions that can discharge the liquid developer and the carrier liquid, and are arranged at equal intervals along the axial direction of the electrode roller 382 in the longitudinal direction of the second container 380b. The second discharge opening 380e is provided in the vicinity of a portion where the electrode roller 382 and the dam roller 383 are in contact with each other. As described above, when the carrier liquid that is the extracted dispersion medium is recovered by stopping the rotation of the electrode roller 382, the carrier liquid can be efficiently recovered before the carrier liquid flows down in the liquid storage container 380. . The second liquid transport passage 380g is a portion for transporting the liquid developer and carrier liquid collected from the second discharge opening 380e to the second discharge port 380h, and is provided along the longitudinal direction of the second container 380b. It has been. The second discharge port 380h is a portion for discharging the liquid developer and carrier liquid of the second liquid transport passage 380g to the outside, and is provided at a substantially central portion in the longitudinal direction of the second liquid transport passage 380g. Here, the second discharge port 380h and the second liquid transport passage 380g are provided in a second liquid discharge member 380v that is separate from the second container 380b. The second liquid discharge member 380v is attached to the second container 380b with a screw 380s (see FIG. 16). Further, the second liquid discharge member 380v is provided with a concave liquid leakage prevention member mounting portion, and a liquid leakage prevention member 380y is provided over the entire contact portion between the second container 380b and the second liquid discharge member 380v ( FIG. 17).

  The dam roller 383 is a roller made of an elastic member whose surface is disposed so as to be in contact with the electrode roller 382 and subjected to a conductive treatment, and is biased to the electrode roller 382 side by a biasing mechanism 387 (see FIG. 19). Is elastically deformed. It should be noted that the electrode roller 382 has a minus 500 V and the dam roller 383 has a plus 500 V so that an electric field is generated between the electrode roller 382 and the dam roller 383 so that the toner moves from the dam roller 383 to the electrode roller 382. Is applied. Similarly, plus 500 V is applied to the liquid container 380 so that an electric field is generated between the electrode roller 382 and the liquid container 380 so that the toner moves from the liquid container 380 to the electrode roller 382. Furthermore, pulleys 383 a that can rotate relative to the dam roller 383 are disposed at both axial ends of the dam roller 383.

  The blade member 384 as a cleaning member is located downstream of the position where the electrode roller 382 and the weir roller 383 are in contact with each other in the rotation direction of the electrode roller 382 and upstream of the position where the ejection opening 380d opens in the first container 380a. On the side, it is a plate-like member that is disposed so as to contact the electrode roller 382 and extends in the direction in which the rotation shaft 382a of the electrode roller 382 extends.

  The voltage application device 285 is the same as that of the first embodiment, and is connected to the liquid storage container 380, the electrode roller 382, and the dam roller 383 so that a voltage can be applied.

  As shown in FIG. 19, the liquid movement prevention unit 386 is a member disposed at both ends in the axial direction of the dam roller 383 and the electrode roller 382, and includes a circular hole in which the shaft of the dam roller 383 can be disposed. And a portion having the same curvature as the curvature of the electrode roller 382.

  The urging mechanism 387 is a mechanism for urging the weir roller 383 toward the electrode roller 382, and is disposed at one end of the coil spring 387a fixed to an outer frame (not shown) and the other end of the coil spring 387a. And a roller shaft support member 387b capable of supporting the shaft of the weir roller 383. Therefore, the shaft of the dam roller 383 is urged by the coil spring 387a via the roller shaft support member 387b.

  Next, the separation operation of the toner and the carrier liquid in the liquid developer separation / extraction apparatus 300 will be described.

  First, the residual developer recovered in the residual developer recovery container 279 (see FIG. 2) is conveyed to the liquid developer separation / extraction apparatus 300 by a pump P9 (see FIG. 2) every predetermined amount. Specifically, the residual developer is supplied from the supply port 380f to the first liquid transport passage 380i, and the residual developer is transported to each ejection opening 380d by the first liquid transport passage 380i. Thereafter, the residual developer is ejected from the ejection opening 380d into the first container 380a. At the same time, the electrode roller 382 and the weir roller 383 start rotating. At this time, the voltage application device 285 applies voltages to the liquid container 380, the weir roller 383, and the electrode roller 382, respectively. For this reason, an electric field is generated between the liquid container 380 and the weir roller 383 and the electrode roller 382 so that the toner moves in the direction of the electrode roller. As a result, of the liquid developer stored in the liquid storage container 380, the charged toner moves to the electrode roller 382 side, and the carrier liquid having no charged charge remains on the liquid storage container 380 side. Further, the application of such a voltage prevents the toner from adhering to the blocking roller 383 and the liquid container 380. As the electrode roller 382 rotates, the liquid developer is conveyed to the contact portion between the electrode roller 382 and the weir roller 383. Then, the toner is electrically attracted to the electrode roller 382 and is electrically urged by the dam roller 383 in a direction away from the dam roller 383, that is, the electrode roller 382 side. For this reason, the toner adhering to the electrode roller 382 passes between the electrode roller 382 and the weir roller 383. Then, the toner adhering to the electrode roller 382 is scraped off by the blade member 384. This toner is discarded in this embodiment, but may be reused. When it is confirmed by the carrier liquid concentration measuring device 81 (not shown) (see FIG. 2) that the concentration of the toner remaining in the carrier liquid in the liquid container 380 is equal to or lower than a predetermined value, the electrode roller 382 The rotation of the weir roller 383 is stopped, and the pump P10 (see FIG. 2) is operated, whereby the carrier liquid extracted in the liquid container 380 is discharged from the first discharge opening 380c and the second discharge opening 380e. Then, it is conveyed to the carrier tank 274 (see FIG. 2). The electrode roller 382 and the weir roller 383 are rotated at a low speed of about several rpm, and there is no major problem even if the carrier liquid is collected in a rotated state.

  Here, since the 1st discharge opening 380c is provided in the lowest position of the 1st container 380a recessed part 380k, collection | recovery of the extracted dispersion medium (carrier liquid) can be performed smoothly. Further, since a large number of ejection openings 380d are provided in the longitudinal direction of the first container 380a and along the axial direction of the electrode roller 382, the liquid developer supplied to the liquid developer separation / extraction device 300 is quickly supplied to the electrode roller. It can diffuse in the axial direction of 382. Further, since the plurality of second discharge openings 380e are arranged at equal intervals in the longitudinal direction of the second container 380b, the discharge efficiency of the carrier liquid can be improved. Since the first container 380a and the second container 380b are detachable, maintenance and the like can be easily performed.

<Third Embodiment>
The configuration of the liquid developer separation / extraction apparatus 400 according to the third embodiment of the present invention is shown in FIGS. The other configuration of the image forming apparatus provided with the liquid developer separation and extraction apparatus 400 is the same as that of the color printer 1 according to the first embodiment. The liquid developer separation and extraction device 400 includes an electrode roller 482, a liquid container 480, a weir roller 483, a blade member 484, a voltage application device 285 (see FIG. 2), and a liquid movement prevention unit 486 (FIG. 28). A dam roller urging mechanism 487 (see FIG. 28), a first container urging mechanism 488 (see FIG. 29), and a second container urging mechanism 489.

  The electrode roller 482 is a pipe-shaped member made of metal (specifically, SUS), is a member to which a voltage is applied, and is connected to the voltage application device 285. As shown in FIG. 27, the electrode roller 482 includes a rotating shaft 482a and a roller portion 482b, a shaft support member 482c, and a seal packing 482d. The shaft support member 482c is an annular member and is disposed at both ends of the roller portion 482b in the axial direction. The diameter of the shaft support member 482c and the diameter of the roller portion 482b are the same. The shaft support member 482c has six protrusions 482e formed on the outer periphery. The protrusion 482e is in contact with the liquid container 480 and positions the liquid container 480. Note that the height of the protrusion 482e is 0.5 mm, and the electrode roller 482 and the liquid container 480 face each other with a minute interval of 0.5 mm. Further, the shaft support member 482c is formed with a pair of wall-like portions 482f projecting outward in the axial direction on the inner peripheral side, and a stationary electrode (not shown) that rotatably supports the rotating shaft 482a of the electrode roller 482. The roller 482 is inserted into the bearing. For this reason, the shaft support member 482c is fixed. A rotating shaft 482a of the electrode roller 482 is supported by a bearing fixed to an outer wall (not shown), and the rotating shaft 482a is driven by a driving source (not shown) arranged outside the outer wall. The shaft support member 482c can be provided with a seal packing 482d on the end surface facing the wall surface of the liquid container 480. The seal packing 482d prevents the liquid from moving outward in the axial direction.

  The liquid storage container 480 is a container that can store a liquid developer composed of toner (dispersion medium) and carrier liquid (dispersoid), and is formed of a conductive material. The liquid container 480 is connected to the voltage application device 285, and includes a first container 480a, a second container 480b, and a seal member 480j.

  As shown in FIGS. 22 and 23, the first container 480a is a substantially rectangular parallelepiped member in which a semi-cylindrical recess 480k is formed so as to be positioned at a predetermined distance from the surface of the electrode roller 482. , A first discharge opening 480c, an ejection opening 480d, a first liquid transport passage 480i, and a supply port 480f. In addition, tray covers 480ad are disposed at both ends in the longitudinal direction. The tray cover 480ad faces a bearing (not shown) that rotatably holds the rotating shaft 482a of the electrode roller 482 with a small interval. The tray cover 480ad is a member that prevents the liquid developer remaining in the first container 480a from leaking outside when the first container 480a is removed from the electrode roller 482. Further, the first container 480a is provided with a first attaching / detaching portion 480m that is formed substantially horizontally and to which the second container is attached / detached, in the vicinity of the electrode roller 482, specifically, on the right side in FIG. The first discharge opening 480c is a portion where the liquid developer and the extracted carrier liquid can be discharged, and is provided at the lowest position of the recess 480k at the approximate center in the longitudinal direction of the first container 480a. The first discharge opening 480c is a passage that is connected to the outside from the surface of the first container 480a and allows liquid to pass through. Here, the end of the first discharge opening 480c on the recess 480k side is positioned with high accuracy so that no step is formed between the end 480k and the recess 480k. The ejection openings 480d are arranged at equal intervals in the longitudinal direction of the first container 480a, and are portions where the liquid developer can be ejected toward the electrode roller 482. Further, each ejection opening 480d is connected to the first liquid transport passage 480i. The first liquid transport passage 480i is a passage for transporting the liquid developer to each ejection opening 480d, and is provided along the longitudinal direction of the first container 480a. The supply port 480f is a portion for supplying the liquid developer to the recess 480k of the first container 480a, and is connected to the first liquid transport passage 480i.

  The second container 480b is detachable from the first container 480a, and has a concave portion 481k that is curved along the electrode roller 482 when disposed with respect to the electrode roller 482, and is connected to the first container 480a. In this state, about 75% of the electrode roller 482 is covered together with the first container 480a. Thus, the liquid container 480 has a shape that covers most of the electrode roller 482, and the gap between the electrode roller 482 and the liquid container 480 is as small as 0.5 mm as described above. Therefore, the liquid container 480 is integrated. If present, it is difficult to remove the electrode roller 482 as it is. In addition, as shown in FIGS. 21, 24, 25, and 26, the second container 480b includes a second discharge opening 480e, a second liquid transfer passage 480g, and a second discharge port 480h. . The second container 480b is provided with a second attaching / detaching part 480n that can be attached to and detached from the first attaching / detaching part 480m of the first container 480a. The second discharge openings 480e are portions where the liquid developer and the extracted carrier liquid can be discharged, and are arranged at equal intervals in the longitudinal direction of the second container 480b. The second liquid transport passage 480g is a part for transporting the liquid developer and carrier liquid collected from the second discharge opening 480e to the second discharge port 480h, and extends along the longitudinal direction of the second container 480b. Is provided. The second discharge port 480h is a portion for discharging the liquid developer and carrier liquid of the second liquid transport passage 480g to the outside, and is provided at a substantially central portion in the longitudinal direction of the second liquid transport passage 480g. The second liquid transport passage has the same configuration as the first liquid transport passage 480i.

  The seal member 480j is a member for preventing the liquid developer and the carrier liquid from leaking to the outside from the attachment / detachment portions 480m and 480n between the first container 480a and the second container 480b, and is a member formed of cell polymer It is. Further, the seal member 480j is disposed between the first attaching / detaching portion 480m and the second attaching / detaching portion 480n, and is adhered to the first container 480a side and disposed in an elastically deformed state.

  The dam roller 483 is a roller made of an elastic member (specifically, a structure in which a SUS pipe is covered with urethane rubber whose surface is subjected to conductive treatment) disposed so as to be in contact with the electrode roller 482. The 482 side is elastically deformed by being urged by a weir roller urging mechanism 487 (see FIG. 28). Furthermore, pulleys 483 a that can rotate relative to the weir roller 483 are disposed at both ends of the weir roller 483 in the axial direction. It should be noted that the electrode roller 482 is minus 500 V and the dam roller 483 is plus 500 V so that an electric field is generated between the electrode roller 482 and the dam roller 483 so that the toner moves from the dam roller 483 to the electrode roller 482. Is applied. Similarly, 500 V is applied to the liquid container 480 so that an electric field is generated between the electrode roller 482 and the liquid container 480 so that the toner moves from the liquid container 480 to the electrode roller 482.

  The blade member 484 as a cleaning member is located at a position downstream of the electrode roller 482 in the rotation direction with respect to the position where the electrode roller 482 and the weir roller 483 are in contact with each other, and at a position where the ejection opening 480d opens in the first container 480a. It is a plate-like member that is disposed on the upstream side so as to contact the electrode roller 482 and extends in the direction in which the rotation shaft 482a of the electrode roller 482 extends.

  The voltage application device 285 is the same as that of the first embodiment, and is connected to the liquid container 480, the electrode roller 482, and the dam roller 483 so that a voltage can be applied.

  As shown in FIG. 28, the liquid movement preventing portion 486 is a member disposed at both ends in the axial direction of the dam roller 483 and the electrode roller 482, and has a circular hole in which the shaft of the dam roller 483 can be disposed. And a portion having the same curvature as the curvature of the electrode roller 482.

  The dam roller urging mechanism 487 is a mechanism for urging the dam roller 483 toward the electrode roller 482, and as shown in FIG. 29, a first coil spring having one end fixed to an outer frame (not shown). 487a and a roller shaft support member 487b which is disposed at the other end of the first coil spring 487a and can support the shaft of the weir roller 483. Therefore, the shaft of the weir roller 483 is urged by the first coil spring 487a via the roller shaft support member 487b.

  The first container urging mechanism 488 is a mechanism for urging the first container 480a to the side where the electrode roller 482 is disposed, that is, the upper side in FIG. 20, and is disposed below the first container 480a. ing. As shown in FIGS. 20 and 29, the first container urging mechanism 488 includes a first contact member 488a, a second coil spring 488b, and a spring support member 488c. The first contact member 488a is a member that contacts the first container 480a, and is provided in the vicinity of both ends in the longitudinal direction of the first container 480a. The first contact member 488a is a disk-shaped portion and is connected to one end of the second coil spring 488b. The second coil spring 488b is a member for urging the first contact member 488a toward the electrode roller 482, and the other end is connected to the spring support member 488c.

  The second container urging mechanism 489 is a mechanism for urging the second container 480b toward the first container 480a, that is, the lower side in FIG. 20, and is disposed above the second container 480b. The second container urging mechanism 489 includes a second contact portion 489a that contacts the second container 480b and a urging member (not shown) that urges the second contact portion 489a.

  Next, the separation operation of the toner and the carrier liquid in the liquid developer separation / extraction apparatus 400 will be described.

  First, the residual developer recovered in the residual developer recovery container 279 (see FIG. 2) is conveyed to the liquid developer separation and extraction device 400 by a pump P9 (see FIG. 2) every predetermined amount. At this time, the electrode roller 482 and the weir roller 483 start to rotate, and a voltage is applied to the liquid container 480, the weir roller 483, and the electrode roller 482 by the voltage application device 285, respectively. As a result, an electric field is generated between the liquid container 480 and the weir roller 483 and the electrode roller 482 so that the toner moves in the direction of the electrode roller. For this reason, the toner having a charged charge in the liquid developer stored in the liquid container 480 moves to the electrode roller 482 side, and the carrier liquid having no charged charge remains on the liquid container 480 side. As the electrode roller 482 rotates, the liquid developer is conveyed to the contact portion between the electrode roller 482 and the weir roller 483. The toner is electrically attracted to the electrode roller 482 and a voltage having the same charging polarity as that of the toner is applied to the dam roller 483, so that an electric repulsive force is received from the dam roller 483 to the dam roller 483. It is electrically biased away from the electrode roller 482, that is, toward the electrode roller 482. When the voltage having the same charging polarity as that of the toner is applied to the liquid container 480, the toner receives an electric repulsive force from the liquid container 480 and is electrically biased toward the electrode roller 482. Application of such a voltage prevents the toner from adhering to the weir roller 483 and the liquid container 480. In this way, the toner is electrically attached to the electrode roller 482, and for this reason, the toner attached to the electrode roller 482 passes between the electrode roller 482 and the weir roller 483. Then, the toner adhering to the electrode roller 482 is scraped off by the blade member 484. Here, the toner is discarded, but may be reused. When it is confirmed by the carrier liquid concentration measuring device 81 (see FIG. 2) that the concentration of the toner remaining in the carrier liquid in the liquid container 480 has become a predetermined value or less, the electrode roller 482 and the weir roller The rotation of 483 is stopped, and the carrier liquid extracted by the pump 10 (see FIG. 2) is discharged from the first discharge opening 480c and the second discharge opening 480e, and is conveyed to the carrier tank 274 (see FIG. 2). The electrode roller 482 and the weir roller 483 are rotated at a low speed of about several rpm, so that there is no major problem even if the carrier liquid is collected in the rotated state.

  In the case of maintenance, the biasing by the first container biasing mechanism 488 or the second container biasing mechanism 489 is released, and the connection between the first container 480a and the second container 480b of the liquid container 480 is released. To do. Thereafter, the liquid container 480 is removed from the electrode roller 482.

  Here, since the liquid storage container 480 can be divided into the first container 480a and the second container 480b, the distance between the electrode roller 482 and the liquid storage container 480 is as narrow as 0.5 mm, and the liquid storage container Despite the structure that 480 covers most of the electrode roller 482, the liquid container 480 can be easily removed from the electrode roller 482 during maintenance of the electrode roller 482, and the liquid container 480 is disposed on the electrode roller 482. It becomes easy to install when doing. Further, since the seal member 480j is disposed between the first attaching / detaching portion 480m of the first container 480a and the second attaching / detaching portion 480n of the second container 480b, the liquid developer is provided from the inside of the liquid storage container 480 to the outside. Can be prevented from leaking. Furthermore, since the first attaching / detaching portion 480m and the second attaching / detaching portion 480n are provided substantially horizontally, the liquid developer is difficult to leak.

<Other embodiments>
(A) Although the blade member is used as the cleaning member in the above embodiment, other members may be used as long as they can remove the toner attached to the electrode roller such as a cleaning roll and a cleaning brush.

  (B) In the above embodiment, the toner is used as the dispersoid and the carrier liquid is used as the dispersion medium. And water may be used as a dispersion medium.

  (C) In the above embodiment, the protrusion 282f is provided on the outer peripheral surface of the shaft support member 282c. However, the present invention is not limited to this, and a protrusion is provided on the surface corresponding to the shaft support member 282c of the liquid container 281. You may do it.

  (D) In the above embodiment, the first discharge opening 380c is single, but a large number may be provided in the axial direction of the electrode roller 382 like the second discharge opening 380e.

  (E) The ejection opening 380d is provided at the most upstream position in the rotation direction of the electrode roller 382 of the first container 380a when viewed from the position of the cleaning blade. However, the arrangement may be appropriate, and the first discharge opening 380c and the second discharge opening 380e. It may be provided in between.

  (F) The liquid developer may be supplied to the liquid developer separation / extraction device 28 by directly supplying the liquid developer to the surface of the exposed portion of the electrode roller 282.

  (G) In the above embodiment, the cell polymer is used as the seal member 480j. However, the present invention is not limited to this, and other substances such as rubber may be used.

  (H) Further, in the above-described embodiment, the first container urging mechanism 488 and the second container urging mechanism 489 are provided to urge the first container 480a toward the electrode roller 282 and the second container 480b to the first container. Although urged toward the 480a side, the movement of either the first container 480a or the second container 480b is restricted and the other of the first container 480a or the second container 480b is moved to one side. You may make it energize.

1 is an overall schematic diagram of a color printer. FIG. 2 is an overall schematic view of a residual developer circulation device. 1 is an overall cross-sectional view of a liquid developer separation / extraction apparatus according to a first embodiment. 1 is an overall cross-sectional view of a liquid developer separation / extraction apparatus according to a first embodiment. The whole perspective view of the 1st container. The figure which shows an electrode roller. FIG. 3 is a cross-sectional view of the liquid developer separation / extraction apparatus according to the first embodiment. The elements on larger scale of FIG. The figure which shows the one end side of an electrode roller and a weir roller. FIG. 9 is an overall cross-sectional view of a liquid developer separation / extraction apparatus according to a second embodiment. FIG. 9 is an overall cross-sectional view of a liquid developer separation / extraction apparatus according to a second embodiment. The whole perspective view of the 1st container. The figure which shows the bottom face side of a 1st container. The fragmentary sectional view of the 1st container. The figure which shows a 2nd container. The figure which shows the 2nd discharge port of a 2nd container. Sectional drawing of a 2nd container. The figure which shows an electrode roller. The figure which shows the one end side of an electrode roller and a weir roller. FIG. 10 is an overall cross-sectional view of a liquid developer separation / extraction apparatus according to a third embodiment. The whole sectional view in the state where the liquid storage container was separated into the 1st container and the 2nd container. The whole perspective view of the 1st container. The fragmentary sectional view of the 1st container. The figure which shows a 2nd container. The figure which shows the 2nd discharge port of a 2nd container. Sectional drawing of a 2nd container. The figure which shows an electrode roller. The figure which shows the one end side of an electrode roller and a weir roller. FIG. 10 is an overall perspective view of a liquid developer separation / extraction apparatus according to a third embodiment.

Explanation of symbols

1 Color printer (image forming device)
28,300,400 Liquid developer separation and extraction device (liquid sample separation and extraction device)
281, 380, 480 Liquid container 281 c, 380 r First outlet 281 e, 380 h, 480 h Second outlet 282, 382, 482 Electrode roller (electrode member)
283, 383, 483 Dam roller (dam member)
284, 384, 484 Blade member (cleaning member)
286, 386, 486 Liquid movement prevention part

Claims (4)

A liquid sample separation and extraction device for separating the dispersoid and the dispersion medium from a liquid sample containing the dispersoid and the dispersion medium, and extracting the dispersoid and the dispersion medium,
A liquid storage container capable of storing the liquid sample;
An electrode member disposed in contact with the liquid sample in the liquid container;
A blocking member that contacts the electrode member and blocks the dispersion medium;
A cleaning member that scrapes off the dispersoid that has passed through the position where the electrode member and the blocking member are in contact;
A liquid movement preventing portion that is provided at both longitudinal ends of the damming member and prevents the liquid from moving outward in the longitudinal direction of the damming member;
With
A voltage is applied to the electrode member and the blocking member so as to generate an electric field that moves the dispersoid to the electrode member side between the electrode member and the blocking member.
A voltage is applied to the electrode member and the liquid storage container so as to generate an electric field that moves the dispersoid to the electrode member side between the electrode member and the liquid storage container .
The liquid container is disposed at the lowest height position in the liquid container, and in the vicinity of the first discharge port capable of discharging the dispersion medium, and the contact portion between the damming member and the electrode member. A second outlet disposed,
The liquid sample separation and extraction device , wherein a position of the second discharge port in the height direction is lower than a contact portion between the dam member and the electrode member and higher than the first discharge port . The liquid sample separation / extraction apparatus according to claim 1, wherein the dispersoid is a toner, and the dispersion medium is a carrier liquid. The dam member is biased to the electrode member, the liquid sample separation and extraction device according to claim 1 or 2. An image forming unit that forms an image on a medium using a liquid developer containing toner and a carrier liquid;
A liquid developer separating and extracting device for separating the toner and the carrier liquid from the liquid developer, and extracting the toner and the carrier liquid;
With
The liquid developer separation / extraction apparatus comprises:
A liquid storage container capable of storing the liquid developer;
An electrode member disposed in contact with the liquid developer in the liquid container;
A blocking member that contacts the electrode member and blocks the carrier liquid;
A cleaning member that scrapes off the toner that has passed through the position where the electrode member and the blocking member are in contact with each other;
A liquid movement preventing portion that is provided at both longitudinal ends of the damming member and prevents the liquid from moving outward in the longitudinal direction of the damming member;
Have
A voltage is applied to the electrode member and the blocking member so as to generate an electric field that moves toner toward the electrode member between the electrode member and the blocking member.
A voltage is applied to the electrode member and the liquid storage container so as to generate an electric field that moves toner toward the electrode member between the electrode member and the liquid storage container .
The liquid container is disposed at the lowest height position in the liquid container, and in the vicinity of the first discharge port capable of discharging the dispersion medium, and the contact portion between the damming member and the electrode member. A second outlet disposed,
The position of the second discharge port in the height direction is lower than the contact portion between the dam member and the electrode member and higher than the first discharge port .

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