JP2008287087A - Liquid sample separation and extraction apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve efficiency in a separation operation for liquid developer in a liquid developer separation and extraction apparatus. <P>SOLUTION: The separation and extraction apparatus separating toner and carrier liquid from the liquid developer containing the toner and the carrier liquid, and extracting the toner and the carrier includes an electrode roller 41 and a concentration detection device. The liquid storing container has a first window part 42e through which light from outside can be transmitted and a second window part 42f through which the light transmitted through the first window part 42e can be transmitted from the inside to the outside. The container is arranged to face an electrode roller 41 with a prescribed gap in-between, has a surface facing the electrode roller 41 formed of conductive material, and can store the liquid sample at least in the prescribed gap. The concentration detection device has a light emitting member 461 which can emit light toward the first window 42e and a light receiving member 462 which can receive light transmitted through the second window part 42f and detects the concentration of the liquid developer stored inside the liquid storing container. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid sample separation and extraction apparatus and an image forming apparatus, and in particular, a liquid sample separation and extraction apparatus that separates a dispersoid and a dispersion medium from a liquid sample containing the dispersoid and the dispersion medium and extracts the dispersoid and the dispersion medium. The present invention also relates to an image forming apparatus including the liquid sample separation and extraction apparatus.

  An image forming apparatus that forms an image using a liquid developer includes an image forming unit that forms an image on a sheet using a liquid developer, a sheet storage unit that stores the sheet, and a sheet that conveys the sheet to the image forming unit. A conveyance unit and a sheet discharge unit capable of discharging a sheet on which an image is formed are provided. In this image forming apparatus, the paper stored in the paper storage unit is transported to the image forming unit by the paper transport unit, and after the image is formed on the paper by the image forming unit, the paper is discharged from the paper discharge unit to the outside. .

  Some of such image forming apparatuses further include a liquid developer circulating device that collects a liquid developer that is not used for image formation and reuses it. The liquid developer circulation device includes a liquid developer carrying member capable of carrying a liquid developer, a liquid developer collecting mechanism for collecting the liquid developer from the developing device, and storing the collected liquid developer in a storage container. A liquid developer adjusting mechanism for adjusting the concentration of the developer in the storage container with the high-concentration developer and the carrier liquid, and a supply mechanism for supplying the developing device with the liquid developer adjusted in concentration by the liquid developer adjusting mechanism. (See Patent Document 1)

In this liquid developer circulation device, a liquid developer carrying mechanism and a liquid developer that is not used for image formation of the developing device are collected by a liquid developer collecting mechanism. Then, the concentration of the liquid developer recovered by the liquid developer adjusting mechanism is adjusted, and the liquid developer is supplied to the developing device by the supply mechanism.
JP 2003-167442 A

  In the liquid developer circulating device, the liquid developer may be deteriorated due to the influence of charging or the like, and it is difficult to reuse this developer as it is. For this purpose, it is conceivable that the liquid developer is once recovered, and the recovered liquid developer is separated into toner and carrier liquid and reused.

  In such a separation / extraction apparatus capable of separating the toner and the carrier liquid, it is necessary to detect the concentration of the liquid developer and check whether the liquid developer is separated into the toner and the carrier liquid. For this reason, it is necessary to transfer the liquid developer after the separation and extraction operation stored in the separation and extraction device to another container and detect the concentration in the other container. Then, after detecting the concentration of the liquid developer, the toner and the carrier liquid are reused or discarded in the case of a predetermined concentration (in the case of a concentration that can be determined to be separated). It is necessary to return to the separation / extraction apparatus again and repeat the separation operation. However, if such a concentration detection operation is repeated, the efficiency of the separation operation becomes worse. That is, the time and effort for density detection increase and the time for density detection is also required.

  An object of the present invention is to increase the efficiency of a liquid developer separation operation in a liquid developer separation and extraction apparatus.

  A liquid sample separation and extraction device according to claim 1 is a liquid sample separation and extraction device for separating a dispersoid and a dispersion medium from a liquid sample containing the dispersoid and a dispersion medium, and extracting the dispersoid and the dispersion medium, An electrode roller, a liquid container, a voltage application device, and a concentration detection device are provided. The liquid container has a first window portion made of a material capable of transmitting light from outside to the inside, and a second window portion capable of transmitting light transmitted through the first window portion from the inside to the outside. The container is arranged so as to face the electrode roller with a predetermined gap, the surface facing the electrode roller is formed of a conductive material, and is a container capable of accommodating a liquid sample at least in the predetermined gap. The voltage application device is a device that can apply a voltage to the electrode roller and the liquid container. The concentration detector includes a light emitting member capable of emitting light toward the first window portion and a light receiving member capable of receiving light transmitted through the second window portion, and the liquid developer accommodated in the liquid container The concentration of is detected.

  In this liquid sample separation and extraction apparatus, a liquid sample is stored in a gap between the liquid storage container and particularly the electrode roller, and a voltage is applied to the liquid storage container and the electrode roller by a voltage application device. At this time, the liquid sample is separated into the dispersoid and the dispersion medium by applying a voltage to the liquid container and the electrode roller. Then, after the separation into the dispersoid and the dispersion medium, the concentration of the liquid sample is detected by the concentration detector. Specifically, light is generated from the light emitting member so as to pass through the first window, and this light passes through the liquid container (gap between the electrode rollers) and passes through the second window. The light receiving member receives the light. Thus, the density is detected based on the amount of light received by the light receiving member.

  Here, since the concentration of the liquid sample can be detected without removing the liquid sample from the liquid container, the efficiency of the liquid sample separation operation in the liquid sample separation and extraction apparatus can be increased.

  A liquid sample separation and extraction apparatus according to claim 2 is the liquid sample separation and extraction apparatus according to claim 1, wherein the surface of the electrode roller and the surface of the liquid container that faces the electrode roller are made of a metal that can reflect light. Is formed.

  In this liquid sample separation and extraction apparatus, when detecting the concentration of the liquid sample, the light emitted from the light emitting member is transmitted through the first window, and the surface of the electrode roller and the surface of the liquid container that faces the electrode roller Passing through the liquid sample existing between both surfaces while repeating the reflection between the two. Thereafter, the light passing through the liquid sample passes through the second window and is received by the light receiving member. Here, light is easily reflected on the surface of the electrode roller and the surface of the liquid container.

  A liquid sample separation and extraction apparatus according to a third aspect is the liquid sample separation and extraction apparatus according to the first or second aspect, wherein the first window portion is arranged at one end in the longitudinal direction of the liquid storage container. The second window is disposed at the other longitudinal end of the liquid container. The light emitted from the light emitting member passes through the first window portion, and after repeating reflection between the surface of the electrode roller and the liquid container, passes through the second window portion and is received by the light receiving member.

  Here, since the optical path length of the light emitted from the light emitting member can be sufficiently secured, the concentration can be easily detected even when the concentration of the liquid developer is low.

  A liquid sample separation and extraction device according to claim 4 is the liquid sample separation and extraction device according to any one of claims 1 to 3, wherein the concentration detection device instructs the light emitting member to emit light and the light receiving member receives the light. A controller that calculates the density from the amount of light; a driver that drives the light emitting element of the light emitting member according to an instruction signal from the controller; and a receiver that inputs a signal obtained from the light received by the light receiving member to the controller. is doing.

  A liquid sample separation / extraction apparatus according to claim 5 is the liquid sample separation / extraction apparatus according to any one of claims 1 to 4, wherein a damming roller that contacts the electrode roller and dams the dispersion medium, and an electrode roller And a cleaning member that scrapes off the dispersoid that has passed through the position where the weir roller and the weir roller are in contact with each other.

  In this liquid sample separation and extraction apparatus, the liquid sample is conveyed to the contact portion between the electrode roller and the damming roller as the electrode roller rotates, and the dispersion medium is dammed by the damming roller at this portion. That is, the dispersoid passes through a position where the electrode roller and the weir roller are in contact. This dispersoid is scraped off by a cleaning blade. In this way, the liquid sample is separated and extracted into the dispersoid and the dispersion medium.

  A liquid sample separation and extraction apparatus according to a sixth aspect is the liquid sample separation and extraction apparatus according to any one of the first to fifth aspects, wherein the light emitting member is tilted toward the side where the light receiving member is disposed in the first window portion. Irradiate. The light receiving member is arranged so as to be tilted so that the light from the light emitting member can be received.

  Here, the light receiving member can easily receive the light emitted from the light emitting member.

  An image forming apparatus according to claim 7 is an image forming apparatus that forms an image using a liquid developer, and is an electrostatic latent image carrier, a charging device, an exposure device, a liquid developing device, and a transfer device. And a cleaning device and a separation and extraction device. The electrostatic latent image carrier can carry an electrostatic latent image on its surface. The charging device charges the surface of the electrostatic latent image carrier. The exposure device forms an electrostatic latent image by exposing the surface of the electrostatic latent image carrier based on the image data. The liquid developing device develops the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image. The transfer device transfers the toner image to the transfer target. The cleaning device removes the liquid developer remaining on the electrostatic latent image carrier after the toner image is transferred by the transfer device. The separation and extraction device includes a density detection device that performs a separation and extraction operation on the liquid developer removed from the electrostatic latent image carrier by the cleaning device and detects the concentration of the liquid developer.

  In the present invention, the efficiency of the liquid developer separation operation in the liquid developer separation and extraction apparatus can be increased.

  Hereinafter, an embodiment of an image processing apparatus of the present invention will be described based on 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 processing apparatus of the present invention, but the present invention is not limited to this. That is, the image processing 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 transfers a toner image formed by the tandem image forming unit 2 that forms a toner image based on image data, a paper storage unit 3 that stores paper, and the image forming unit 2 onto the paper. The secondary transfer unit 4, the fixing unit 5 that fixes the transferred toner image on the paper, the discharge unit 6 that discharges the fixed paper, and the paper from the paper storage unit 3 to the discharge unit 6 are conveyed. A paper transport unit 7 and a liquid developer circulating device 8 (see FIG. 2) are mainly provided.

  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 which is a transfer target is an endless belt-like member, that is, a loop-like member, and is circulated and driven 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 as an electrostatic latent image carrier, a charger 11 as a charging device, an LED exposure device 12 as an exposure device, and a liquid developing device 9. A primary transfer roller 20 as a transfer device, a cleaning device 26, a static elimination device 13, and a carrier liquid removal roller 30. Further, among the image forming units, the image forming unit FB located closest to the secondary transfer unit 4 is not provided with the carrier liquid removal roller 30, but the other configurations are the same.

  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 liquid developing device 9 is for supplying a liquid developer to the photosensitive drum 10, and includes a developing roller 91, a supply roller 92, a support roller 93, a developer supply member 94, and a developer removing device. 96 and a developer charging device 97. The developing roller 91 is disposed so as to contact the photosensitive drum 10. The supply roller 92 is for supplying the liquid developer to the developing roller 91 and is in contact with the lower part of the developing roller 91. The support roller 93 is a member for supporting the liquid developer together with the supply roller 92, and is disposed so as to contact the supply roller 92. A doctor blade 921 is brought into contact with the supply roller 92. The layer thickness of the liquid developer carried on the supply roller 92 to be supplied to the developing roller 91 by the doctor blade 921 is regulated to a predetermined value. The developer supply member 94 is a member for supplying the liquid developer to the contact portion between the supply roller 92 and the support roller 93. The developer removing device 96 is a device for removing the liquid developer remaining on the developing roller 91 without being supplied to the photosensitive drum 10, and has a developer removing blade 961. The developer removing blade 961 scrapes off the liquid developer on the developing roller 91. The developer charging device 97 is a device for charging the toner in the liquid developer carried on the developing roller 91, and is disposed in the vicinity of the developing roller 91.

  The primary transfer roller 20 as a transfer device is disposed so as to contact the back surface of the portion of the intermediate transfer belt 21 in contact with 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 the developer remaining without being transferred from the photosensitive drum 10 to the intermediate transfer belt 21, and includes a residual developer conveying screw 261 and a drum cleaning blade 262. . The residual developer transport screw 261 is a member for transporting the residual developer stored in the cleaning device 26 to the outside of the cleaning device, scraped off by a drum cleaning blade 262 and a carrier liquid removing roller 30 described later. The cleaning device 26 is disposed. The drum cleaning blade 262 is in sliding contact with the surface of the photosensitive drum 10 and is a member for scraping off the developer remaining on the surface of the photosensitive drum 10, and is a plate extending in the extending direction of the photosensitive drum 10. Shaped member.

  The neutralization device 13 includes a light source. After the developer is removed by the drum 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 the member which removes.

  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 a support roller that supports the intermediate transfer belt 21 and a secondary roller that is disposed to face the support roller. And a transfer roller.

  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.

  The configuration of the liquid developer circulating device 8 will be described based on FIG. 2 showing the overall configuration of the liquid developer circulating device 8. The liquid developer circulating device 8 is a device for reusing liquid developer that is not used for image formation. As shown in FIG. 2, the first developer container 81, the separation and extraction device 40, and the second recovery device are used. A container 83, an adjustment container 84, a toner tank 85, a carrier tank 86, and a reserve tank 87 are provided. The first collection container 81 is a container for collecting the liquid developer remaining on the photosensitive drum 10 conveyed by the residual developer conveyance screw 261. The separation and extraction device 40 is a device for separating the liquid developer in the first recovery container 81 into toner and carrier liquid, and is connected to the first recovery container 81 by a pipe via a pump P9. Here, the separation and extraction device 40 will be described in detail later. The second recovery container 83 is a container for recovering the liquid developer remaining without being used for image formation of the developing roller 91 and the liquid developing device 9, and is provided to the liquid developing device 9 by a pipe to which a pump P5 is attached. In addition, the developer removal device 96 is connected by a pipe to which the pump P1 is attached. The adjustment container 84 is a container for adjusting the toner concentration of the liquid developer, and is connected to the second collection container 83 by a pipe to which the pump P2 is attached. A solid concentration detector 841 is attached to the adjustment container 84 via a pipe to which the pump P4 is attached. The solid content concentration detection device 841 detects the concentration of the liquid developer stored in the adjustment container 84. The toner tank 85 stores a liquid developer having a toner concentration higher than that of the liquid developer used in the liquid developing device 9, and is connected to the adjustment container 84 by a pipe to which a pump P8 is attached. The carrier tank 86 stores a carrier liquid, and is connected to the adjustment container 84 by a pipe to which the pump P3 is attached, and to the separation and extraction device 40 by a pipe to which the pump P10 is attached. The reserve tank 87 stores the liquid developer to be supplied to the liquid developing device 9, and is connected to the adjustment container 84 by a pipe to which the pump P6 is attached and to the liquid developing device 9 by a pipe to which the pump P7 is attached. ing. Each pump has a function of delivering the liquid developer in one direction.

2. Separation and Extraction Device The separation and extraction device 40 will be described with reference to FIG. 2 showing the overall configuration of the liquid developer circulation device 8 and FIG. 3 showing an enlarged view of the separation and extraction device 40 constituting a part of the liquid developer circulation device 8. . As described above, the separation and extraction device 40 is a device for separating and extracting the liquid developer into toner and carrier liquid. The separation and extraction device 40 includes an electrode roller 41, a liquid container 42, a weir roller 43, and roller cleaning. A blade 44, a voltage application device 45, and a concentration detection device 46 (see FIG. 5) are provided.

  The electrode roller 41 is a pipe-shaped member made of metal (specifically, SUS) and is a member to which a voltage is applied, and is electrically connected to the voltage application device 45. Further, the surface of the electrode roller 41 is polished in a mirror shape so that light of a light emitting member 461 described later can be reflected. At both ends of the electrode roller 41, as shown in FIG. 4, flange members 41x fixed to the frame of the separation and extraction device 40 (not shown) in which an annular groove 41c is formed are provided. An annular seal member 41b is disposed in the groove 41c. The seal member 41 b is disposed so as to fill a gap between the electrode roller 41 and the liquid storage container 42, and the liquid developer stored in the liquid storage container 42 leaks outward in the axial direction of the electrode roller 41. Is preventing.

  The liquid storage container 42 is a container that can store a liquid developer, and is formed of a conductive material. Further, the liquid storage container 42 is electrically connected to the voltage application device 45, and includes a first container 42a and a second container 42b as shown in FIG.

  As shown in FIGS. 3 and 4, the first container 42 a is a substantially rectangular parallelepiped member in which an arc-shaped groove 42 c is formed so as to be positioned with a predetermined gap from the surface of the electrode roller 41. In the first container 42a, a first attaching / detaching portion 42d that is formed substantially horizontally and to which the second container 42b is attached / detached is provided in the vicinity of the electrode roller 41, specifically, on the left side in FIG. Further, as shown in FIG. 4, the first container 42a has a first window portion 42e and a second window portion 42f formed at both ends in the longitudinal direction, and the surface on the electrode roller 41 side can reflect light. And is polished to a mirror surface. The first window portion 42e and the second window portion 42f are formed of a transparent member that can transmit light.

  The second container 42b is disposed on the upper side of the first container 42a and is detachable from the first container 42a. The second container 42b is formed with an arc-shaped groove 42h along the electrode roller 41 when arranged with respect to the electrode roller 41. When the second container 42b is connected to the first container 42a, the first container 42a is formed. In addition, about 75% of the electrode roller 41 is covered. Further, the second container 42b is provided with a second attaching / detaching portion 42g that can be attached to and detached from the first attaching / detaching portion 42d of the first container 42a on the left side of FIG. 3, and is detachable from the first container 42a. .

  The dam roller 43 is a roller made of an elastic member (specifically, a structure in which a SUS pipe is covered with urethane rubber whose surface is conductively processed) so as to be in contact with the electrode roller 41.

  The roller cleaning blade 44 as a cleaning member is in contact with the electrode roller 41 on the downstream side in the rotation direction of the electrode roller 41 (right side in FIG. 3) with respect to the position where the electrode roller 41 and the blocking roller 43 are in contact with each other. And a member that scrapes off toner adhering to the electrode roller 41. The electrode roller 41 is a plate-like member extending in the direction in which the rotation shaft 41a extends.

  The voltage application device 45 is a device for applying a voltage to each member, and is connected to the liquid container 42, the electrode roller 41, and the dam roller 43.

  The liquid developer concentration detection device 46 will be described with reference to FIG. FIG. 4 is a diagram schematically illustrating the AA sectional view of FIG. 3 for easy understanding. The liquid developer concentration detection device 46 is a device for detecting the concentration of the liquid developer in the separation and extraction device 40, and is provided in the separation and extraction device 40. As shown in FIG. 5, the liquid developer concentration detection device 46 includes a light emitting member 461, a light receiving member 462, a control unit 463, a driver 464, and a receiver 465.

  The light emitting member 461 is a member for irradiating light into the liquid container 42, and is disposed so as to be inclined so as to irradiate light toward the first window portion 42e. The light emitting member 461 has a light emitting element (LED). Further, the light emitting member 461 is connected to the driver 464 and is disposed below the first window portion 42e.

  The light receiving member 462 is a member for receiving the light emitted from the light emitting member 461, and is disposed below the second window portion 42f. In addition, the light receiving member 462 is connected to the receiver 465, and is inclined to the light emitting member 461 side so as to easily receive light from the light emitting member 461. The light emitting member 461 and the light receiving member 462 are provided so as to face the gap 42m reaching the first window portion 42e and the second window portion 42f from the lower surface of the liquid container 42, respectively. The size of the first window portion 42e and the second window portion 42f is such that the length of the liquid container 42 in the longitudinal direction is 3 mm, and the perpendicular width is 3 mm. The light emitting member 461 is set so that its optical axis is incident at 45 degrees with respect to the surface of the electrode roller 41 corresponding to the right end face in FIG. 4 of the first window portion 42e.

  Here, since the distance between the light emitting member 461 and the light receiving member 462 is intended to measure the concentration of the liquid developer having a toner concentration of about 0.01% in this embodiment, the distance between the light emitting member 461 and the light receiving member 462 is Although there are some differences depending on the color of the toner, about 15 cm is required.

  The controller 463 of the liquid developer concentration detection device 46 will be described with reference to FIG. The control unit 463 is connected to the voltage application device 45, the receiver 465, the driver 464, the pump P9 and the pump P10, and the drive motor 463a such as the electrode roller 41, and controls these members and devices. Part.

  The driver 464 is a member that drives a light emitting element (LED) of the light emitting member 461 in response to a light emission instruction to the light emitting member 461 of the control unit 463.

  The receiver 465 is a member for amplifying a signal based on the light received by the light receiving member 462 and inputting the amplified signal to the control unit 463.

3. Operation Next, an image forming operation of the wet color printer 1 will be described with reference to FIG.

  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 image data is formed on the photosensitive drum 10, and toner is supplied from the liquid developing device 9 to the electrostatic latent image. The images formed by the image forming units 2 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.

  Next, the liquid developer circulation operation will be described with reference to FIG.

  During the image forming operation, the liquid developer remaining on the photosensitive drum 10 without being transferred from the photosensitive drum 10 to the intermediate transfer belt 21 is recovered in the first recovery container 81 by the drum cleaning blade 262. The liquid developer recovered in the first recovery container 81 is transported to the separation and extraction device 40 and separated into toner and carrier liquid, and then the carrier liquid is transported to the carrier tank 86. Further, the liquid developer that is accommodated in the liquid developing device 9 and is not used for image formation, and the liquid developer removed by the developer removing blade 961 from the developing roller 91 of the developing device 9 are collected in the second collection container 83. . The liquid developer stored in the second recovery container 83 is conveyed to the adjustment container 84, and in the adjustment container 84, the toner from the toner tank 85 and the carrier liquid from the carrier tank 86 are supplied as necessary, and the liquid developer is supplied. The developer concentration is adjusted. The liquid developer whose density has been adjusted is conveyed to the reserve tank 87. The liquid developer in the reserve tank 87 is supplied to the liquid developing device 9.

  The liquid developer separation and extraction operation in the separation and extraction apparatus 40 and the concentration detection operation of the liquid developer contained in the separation and extraction apparatus 40 will be described with reference to FIGS.

  When the liquid developer recovered in the first recovery container 81 is transported to the liquid storage container 42 by a predetermined amount, the liquid developer is separated and extracted. Specifically, first, a voltage of +500 V is applied to the liquid container 42 and the weir roller 43 and −500 V is applied to the electrode roller 41 by the voltage application device 45. At this time, the toner (positively charged in this embodiment) is attracted to the electrode roller 41, and the toner adheres to the electrode roller 41. The toner adhering to the electrode roller 41 with the rotation of the electrode roller 41 is conveyed to a portion where the electrode roller 41 and the blocking roller 43 are in contact with each other. When the electrode roller 41 further rotates from this state, the carrier liquid is blocked by the blocking roller 43, so that only the toner adhering to the surface of the electrode roller 41 passes through the contact point between the electrode roller 41 and the blocking roller 43. To do. Thereafter, the toner attached to the electrode roller 41 is scraped off by the roller cleaning blade 44. By continuing such an operation for a certain time, the liquid developer is separated into the toner and the carrier liquid.

  Then, the concentration of the liquid developer in the separation / extraction device 40 is detected in order to detect whether or not the liquid developer in the separation / extraction device 40 has been separated into toner and carrier liquid. When detecting the concentration of the liquid developer in the separation / extraction apparatus 40, a light emission command is issued from the control unit 463 to the light emitting member 461 via the driver 464, and the light emitting member 461 is caused to emit light. The light from the light emitting member 461 passes through the first window portion 42 e and reaches the electrode roller 41. The light reaching the electrode roller 41 is reflected by the surface of the electrode roller 41 and reaches the surface of the liquid container 42 facing the electrode roller 41. Further, the light reaching the surface of the liquid container 42 facing the electrode roller 41 is reflected by the surface of the liquid container 42 facing the electrode roller 41 and reaches the surface of the electrode roller 41. Thus, after reflection is repeated between the surface of the electrode roller 41 and the surface of the liquid container 42 facing the electrode roller 41, the second window portion 42f is transmitted. The light transmitted through the second window portion 42f is received by the light receiving member 462 (see FIG. 4). In addition, the arrow of FIG. 4 shows the advancing direction of light here. A signal based on the light received by the light receiving member 462 is amplified by the receiver 465 and input to the control unit 463. The control unit 463 detects the concentration of the liquid developer based on the input signal, and the detection result is set to a predetermined concentration (concentration at which separation of the liquid developer into the toner and the carrier liquid is considered complete). If not, the developer separating operation is continued. On the other hand, when the concentration is a predetermined concentration, the separation and extraction operation is terminated, and the carrier liquid extracted from the liquid developer in the liquid storage container 42 is conveyed to the carrier tank 86 by operating the pump P10.

  Here, since the concentration of the liquid developer can be detected without taking out the liquid developer from the liquid storage container 42, the liquid developer is transferred from the separation / extraction device 40 to a container other than the liquid storage container 42. There is no need to do. That is, the labor for separating the liquid developer can be saved, and the efficiency of the liquid developer separating operation can be increased.

4). Other Embodiments (a) In the above embodiment, the first window portion 42e and the second window portion 42f are provided at both ends of the liquid storage container 42. However, the present invention is not limited to this, and the color of the liquid developer You may move the 1st window part 42e and the 2nd window part 42f according to a density | concentration. For example, when the color of the liquid developer is a color that easily absorbs light, the distance between the first window part 42e and the second window part 42f may be shortened.

  (B) In the above embodiment, when the detection result does not reach a predetermined concentration, the separation and extraction operation is continued. However, the present invention is not limited to this, and the voltage application device 45 applies the separation and extraction operation. The separation / extraction operation may be performed by changing the voltage or changing the rotation speed of the electrode roller 41.

  (C) In the above embodiment, the liquid developer in which the dispersion medium is a carrier liquid and the dispersoid is a toner is exemplified, but the present invention can be applied to the concentration measurement of various liquid samples. For example, measurement of the concentration of pollutants in river water and seawater in which fine particulate contaminants as dispersoids are dispersed in water as dispersion medium, dye concentration in which dye as dispersoid is dissolved in water of dispersion medium Application examples include measurement of the above, measurement of the amount of a colored liquid dissolved as a solute in water as a solvent, and measurement of blood and a liquid sample after chemical reaction.

1 is an overall schematic diagram of a color printer. 1 is an overall schematic diagram of a liquid developer circulating device. Sectional drawing of a separation extraction apparatus. The axial direction sectional view of a separation extraction device. The block diagram of a light emitting member, a light receiving member, and a control part.

Explanation of symbols

1 Color printer (image forming device)
2 Image forming unit 8 Liquid developer circulating device 40 Separating and extracting device 41 Electrode roller 42 Liquid container 42e First window portion 42f Second window portion 44 Cleaning blade 45 Voltage applying device 46 Concentration detecting device 461 Light emitting member 462 Light receiving member 463 Control Part 464 driver 465 receiver

Claims (7)

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,
An electrode roller;
A first window portion made of a material capable of transmitting light from outside to the inside; and a second window portion capable of transmitting light transmitted through the first window portion from the inside to the outside, and the electrode roller And a liquid storage container that is disposed so as to face each other with a predetermined gap, the surface facing the electrode roller is formed of a conductive material, and can store the liquid sample at least in the predetermined gap;
A voltage applying device capable of applying a voltage to the electrode roller and the liquid container;
A concentration of a liquid developer stored in the liquid storage container, the light receiving member configured to emit light toward the first window; and a light receiving member configured to receive light transmitted through the second window. A concentration detection device for detecting
A liquid sample separation and extraction device.   The liquid sample separation / extraction apparatus according to claim 1, wherein a surface of the electrode roller and a surface of the liquid container facing the electrode roller are formed of a metal capable of reflecting light. The first window portion is disposed at one longitudinal end of the liquid container,
The second window is disposed at the other longitudinal end of the liquid container;
The light emitted from the light emitting member is transmitted through the first window, repeatedly reflected between the surface of the electrode roller and the liquid container, and then transmitted through the second window and received by the light receiving member. To be
The liquid sample separation / extraction apparatus according to claim 1 or 2. The concentration detector is
A controller that instructs the light emitting member to emit light, and calculates a density from the amount of light received by the light receiving member;
A driver for driving a light emitting element of the light emitting member by an instruction signal of the control unit;
A receiver for inputting a signal obtained by the light received by the light receiving member to the control unit;
In addition,
The liquid sample separation / extraction apparatus according to claim 1. A blocking roller that contacts the electrode roller and blocks the dispersion medium;
A cleaning member that scrapes off the dispersoid that has passed through the position where the electrode roller and the weir roller are in contact with each other;
The liquid sample separation / extraction apparatus according to claim 1. The light emitting member is inclined and irradiated to the side where the light receiving member is disposed in the first window portion,
The light receiving member is disposed so as to be able to receive light of the light emitting member,
The liquid sample separation / extraction apparatus according to claim 1. An image forming apparatus that forms an image using a liquid developer,
An electrostatic latent image carrier capable of carrying an electrostatic latent image on the surface;
A charging device for charging the surface of the electrostatic latent image carrier;
An exposure device that forms an electrostatic latent image by exposing the surface of the electrostatic latent image carrier based on image data;
A liquid developing device for developing the electrostatic latent image formed on the electrostatic latent image carrier with toner and forming a toner image;
A transfer device for transferring the toner image to a transfer target;
A cleaning device for removing the liquid developer remaining on the electrostatic latent image carrier after the toner image is transferred by the transfer device;
A separation and extraction device comprising a concentration detection device for performing a separation and extraction operation on the liquid developer removed from the electrostatic latent image carrier by the cleaning device and detecting the concentration of the liquid developer;
An image forming apparatus comprising at least

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