JP3875577B2 - Carrier liquid recycling equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
Carrier liquid recycling that efficiently extracts a high-purity carrier liquid from a carrier liquid containing residual toner particles collected on a latent image carrier (photoconductor) and an intermediate transfer body in an electrophotographic apparatus using a non-volatile liquid toner Relates to the device.
[0002]
[Prior art]
Develops non-volatile, high-viscosity, high-concentration liquid toner in an electrophotographic apparatus that generates an electrostatic latent image on a latent image carrier, attaches toner to the latent image, and transfers and fixes the image onto an intermediate transfer member or paper As a developing method when used as a liquid, the latent image carrier is applied before applying the liquid toner to prevent the liquid toner from adhering to the non-exposed portion of the electrostatic latent image formed on the latent image carrier. On the other hand, a prewetting treatment method in which a prewetting liquid such as silicone oil is applied has been proposed (see JP-A-7-271107).
[0003]
However, since the pre-wet liquid is used, excess oil is present in addition to the liquid toner carrier liquid, which may affect the melting of the toner layer during fixing or at the nip outlet during transfer. Due to the destructive separation of the toner layer, a mottled pattern called a reburette (rib) is generated and the image is disturbed.
[0004]
Therefore, in order to remove the oil component consisting of excess prewet liquid and carrier liquid, a carrier removal mechanism is provided on the position after development on the latent image carrier and on the intermediate transfer body (Japanese Patent Application Laid-Open No. 2005-260707). 2000-250319 or JP 2000-56573). The carrier liquid (including the pre-wet liquid) collected by such a carrier removal mechanism contains toner particles. The carrier liquid can be reused by separating and removing the toner particles. In the case of using the pre-wet liquid, it is assumed that the same kind of oil, for example, silicone oil, is used for the pre-wet liquid and the carrier liquid for reuse.
[0005]
Conventionally, a method for separating a carrier liquid and a solid content from a used developer is known. JP-A-10-74027 stores collected developer once used in a container and rotates it while applying an electric field to a plurality of electrode plates in the developer, and adsorbs them to the electrode plates. Disclosed is a method for removing the solid content with a blade or the like. In this method, it is necessary to temporarily store the collected developer in a container, and there is a lot of time loss. In the case of continuous processing, it is difficult to extract a carrier liquid with high purity.
[0006]
Japanese Patent Laid-Open No. 2000-89573 discloses a method using a foam which is a liquid diffusion suppressing member. This method separates the solid component and the carrier liquid by passing between the electrodes of different potentials in the direction in which the recovered liquid developer passes and electrodepositing the charged solid content on one of the electrodes. A foam is disposed between the electrodes as a liquid diffusion suppressing member that suppresses the diffusion of the developer.
[0007]
Since such a method uses a foam which is a liquid diffusion suppressing member, clogging is likely to occur and the life is short, and the processing capacity is very dependent on the penetration rate into the foam, so the processing capacity is inferior. .
[0008]
[Problems to be solved by the invention]
In the prior art, there is a need to limit the amount of recovered developer that can be processed per unit time. In order to increase the processing amount, there is a method of increasing the area of the electrode plate, but in this case, a very large place is required or the cost is increased.
[0009]
The present invention has been made in view of the above problems, and a carrier liquid with high purity is extracted from a carrier liquid recovered from a photoreceptor and an intermediate transfer body, and a sufficient amount is continuously added with respect to a processing amount. It aims at providing the carrier liquid recycling apparatus which can be processed.
[0010]
[Means for Solving the Problems]
The carrier liquid recycling apparatus of the present invention was recovered from an electrophotographic apparatus that develops an electrostatic latent image formed on a latent image carrier using a liquid developer composed of toner solids and a non-volatile carrier liquid. The mixed residual toner solids are removed from the recovered carrier liquid, and the carrier liquid is separated and extracted. This carrier liquid recycling device has a conductive pipe having an inlet for injecting the recovered carrier liquid and an outlet for discharging the carrier liquid from which the toner solids have been removed, and a radial gap inside the conductive pipe. Ru comprising a conductive roller which is arranged. The conductive pipe has a shape that covers a circumferential gap between the conductive roller and the conductive roller in the circumferential direction from the inlet located upstream in the rotational direction of the conductive roller to the outlet located downstream. The recovery carrier liquid layer formed on the surface of the conductive roller is limitedly moved by the gap from the inlet side for injecting the recovery carrier liquid to the outlet side for extraction. On both sides of the conductive pipe, a gap in the radial direction is sealed so that the recovered carrier liquid does not leak from both sides in the axial direction. Apply a bias voltage in the direction in which the residual toner solids move to the surface of the conductive roller between the conductive pipe and the conductive roller over almost the entire time from when the recovered carrier liquid is injected to when it is extracted. To sufficiently deposit the remaining toner solids on the surface of the conductive roller. A blade having sufficient elasticity to accumulate the carrier liquid while allowing the toner solid matter accumulated on the surface of the conductive roller to pass therethrough is provided on the downstream side in the direction of rotation of the conductive roller so that the conductive pipe and the conductive roller Further, the residual toner solids deposited on the surface of the conductive roller at a position on the circumference of the conductive roller that is not covered by the conductive pipe are arranged so as to block the radial gap between them. A collection blade for collection is provided.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on examples. The present invention targets a carrier liquid collected from an electrophotographic apparatus using a liquid toner having a high viscosity and high concentration that exhibits non-volatility, and from this, the mixed toner solids are removed to extract a high purity carrier liquid. To do. Such a liquid toner uses, for example, a non-volatile silicone oil as a carrier liquid, and has a viscosity of 10 cSt to 200 cSt. In the silicone oil, 5 toner particles having an average particle size of about 0.5 to 3 μm made of resin and pigment are contained. The non-volatile material is dispersed at a ratio of about -30%, preferably 10-25%.
[0014]
The liquid toner recycling apparatus regenerates liquid toner having a predetermined concentration by mixing high-concentration liquid toner, diluted carrier liquid, or both according to the concentration of used liquid toner collected from the developing unit. The high-purity carrier liquid extracted based on the present invention can be reused as a part of the diluted carrier liquid. This makes it possible to reduce the diluted carrier liquid and waste liquid to a small amount.
[0015]
FIG. 1 is a cross-sectional view showing a first example of a carrier liquid extraction apparatus that extracts a carrier liquid with high purity from the recovered carrier liquid. A gap (5 to 2000 μm) is set on the radially inner side of the conductive pipe 1 having a predetermined length in the axial direction, and the rotatable conductive roller 2 is supported by an insulating bearing (not shown). Insulating bearings on both sides in the axial direction not only insulate the conductive roller 2 from the conductive pipe 1 and rotatably support it at the center thereof, but also with the conductive roller 2 on both sides of the conductive pipe 1. A gap in the radial direction between the two is sealed so that the recovered carrier liquid does not leak from both sides in the axial direction. Further, a recovery blade 3 for recovering the residual toner solid content accumulated on the conductive roller 2, a blade 4 for storing the extracted carrier liquid, an inlet 6 for injecting the recovered carrier liquid, and an exhaust for discharging the extracted carrier liquid. An outlet 7 is provided. The conductive roller 2 is grounded to the ground potential G, while the conductive pipe 1 is applied with a bias voltage in a direction to move the toner solid content to the surface side of the conductive roller 2.
[0016]
In the operation of such a carrier liquid extraction device, the used recovered carrier liquid is injected from the injection port 6 while rotating the conductive roller 2 in the direction of the arrow in the drawing while a bias voltage is applied. This carrier liquid moves in the direction of the discharge port 7 as the conductive roller 2 rotates. Since the electric field based on the bias voltage is applied in the radial direction along the relatively long movement path, the toner solid content is sufficiently adhered to the surface of the conductive roller. As a result, a pure carrier liquid is extracted from the discharge port 7. At this time, the blade 4 can be made of, for example, urethane rubber so as to have sufficient elasticity to accumulate the carrier liquid while allowing the toner solid matter adhered and accumulated on the surface side of the conductive roller 2 to pass therethrough. . The toner solid content is scraped and collected by a collection blade 3 which can be made of, for example, urethane rubber.
[0017]
In addition, before the injected carrier liquid is sent to the recycling apparatus, foreign matters such as paper dust other than toner can be removed by a filter in advance.
[0018]
Furthermore, in order to improve the removal efficiency of the toner solids in the recovered carrier liquid, the carrier is used before or after the recovery carrier liquid is injected (for example, by heating the conductive roller 2 or the conductive pipe 1). The liquid can be heated.
[0019]
Further, in the configuration shown in FIG. 1, the recovered carrier liquid is injected from the illustrated outlet 7 side and discharged from the inlet 6 and the rotation speed of the conductive roller 2 is set to be slow (0.01 to 100 mm / s). By doing so, it becomes possible to further improve the purity of the carrier liquid extraction. That is, by injecting the recovered carrier liquid from the downstream side in the direction of rotation of the conductive roller, it is transported to the extraction carrier liquid discharge side (injection port 6 in the figure) by the force (spreading) of the liquid. The time during which the electric field based on the bias voltage is applied can be lengthened, and the carrier liquid with higher purity can be extracted.
[0020]
By providing a release layer on the surface of the conductive roller 2, it is possible to prevent toner solids from adhering to the surface of the conductive roller 2. For example, a fluorine coating can be used for the release layer.
[0021]
FIG. 2 is a diagram illustrating a second example of the carrier liquid extraction device. As shown in the drawing, the conductive flat plate 9 is disposed with an inclination (5 ° to 90 °) with respect to the horizontal plane. Then, another conductive flat plate 11 is arranged in parallel with the conductive flat plate 9 with a predetermined gap (5 μm to 2000 μm) set. Further, the other conductive flat plate 11 is configured to be openable and closable by the rotation fulcrum 10, and is configured such that the cleaning member 12 slides on the conductive flat plate 9 when it is in an open state indicated by a one-dot chain line in the drawing. Has been. The conductive flat plate 9 is grounded to the ground potential, while a bias voltage is applied to another conductive flat plate 11.
[0022]
In the operation of such a carrier liquid extraction device, another conductive flat plate 11 is closed, parallel to the conductive flat plate 9, and a bias voltage is applied. A recovered carrier liquid is injected between two conductive plates. Since the conductive flat plate is disposed with an inclination, the collected developer moves from the right side to the left side in the drawing. Since a bias voltage is applied along this relatively long movement path, the toner solid content is sufficiently adhered and deposited on the surface side of the conductive flat plate 9. As a result, a pure carrier liquid is extracted from the discharge port. Each time a predetermined amount of toner solids accumulates, the injection of the recovered carrier liquid is stopped, another conductive flat plate 11 is opened, and the cleaning member 12 is operated, so that the surface of the conductive flat plate 9 is The toner solid matter deposited on the surface is scraped off and discharged.
[0023]
By providing a release layer on the surface of the conductive flat plate 9, it is possible to prevent toner solid matter from adhering to the surface of the conductive flat plate 9. For example, a fluorine coating can be used for the release layer.
[0024]
In order to improve the removal efficiency of the toner solids in the recovered carrier liquid, the recovered carrier liquid is injected before or after the injection (for example, by heating the conductive plate 9 or another conductive plate 11). ) The carrier liquid can be heated.
[0025]
FIG. 3 is a diagram illustrating a third example of the carrier liquid extraction device. It differs from the second example only in that conductive wires 14 arranged at a predetermined interval are provided in place of the another conductive flat plate 11 shown in FIG. As in the second example, the conductive wire 14 can be opened and closed by the rotation fulcrum 13, and the cleaning member 12 operates in the open state. Then, a bias voltage is applied to the conductive wire 14, while the conductive plate 9 is grounded to the ground potential, and the toner solids are separated from the recovered carrier liquid in the same manner as in the previous example. The carrier liquid is collected.
[0026]
FIG. 4 is a diagram illustrating a cleaning means that can be used in the carrier liquid extraction apparatus as exemplified above. The illustrated cleaning means includes a blade 15 for scraping and collecting the toner solid matter accumulated on the surface of the conductive flat plate 9 and a member 16 for translating the blade 15 along the surface of the conductive flat plate 9. . The blade 15 is in the retracted position indicated by the alternate long and short dash line in the figure when the recovered carrier liquid is being injected, and is moved along the conductive plate 9 during the cleaning operation. The toner solid matter deposited on the surface is scraped off and collected.
[0027]
FIG. 5 is a diagram illustrating a cleaning unit different from FIG. Instead of the blade 15 shown in FIG. 4, a cleaning roller 17 and a scraping blade 18 are used. In the cleaning operation, the cleaning roller 17 is translated while being translated by the member 16 that translates along the surface of the conductive flat plate 9, and is rotated to thereby remove the toner solid content accumulated on the surface of the conductive flat plate 9. This toner solid is then scraped off by the scraping blade 18 and collected.
[0028]
【The invention's effect】
According to the present invention, the layer thickness of the surplus carrier liquid (including residual toner) recovered from the electrophotographic apparatus through the recovery member is formed thick, and high purity is achieved by applying an electric field for a relatively long time. The carrier liquid can be extracted.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a first example of a carrier liquid extraction apparatus that extracts a carrier liquid having a high purity from a recovered carrier liquid.
FIG. 2 is a diagram showing a second example of the carrier liquid extraction device.
FIG. 3 is a diagram showing a third example of the carrier liquid extraction device.
FIG. 4 is a diagram illustrating cleaning means that can be used in the carrier liquid extraction apparatus as exemplified above.
FIG. 5 is a diagram illustrating cleaning means different from FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Conductive pipe 2 Conductive roller 3 Collection | recovery blade 4 Blade 6 which accumulates carrier liquid Inlet 7 Outlet 9 Conductive flat plate 11 Another conductive flat plate 12 Cleaning member 13 Rotation fulcrum 14 Conductive wire 15 Blade 16 Member to move in parallel 17 Cleaning roller 18 Scraping blade

Claims (5)

Residual toner mixed from a recovered carrier liquid recovered from an electrophotographic apparatus that develops an electrostatic latent image formed on a latent image carrier using a liquid developer composed of toner solids and a non-volatile carrier liquid In a carrier liquid recycling device that removes solids and separates and extracts a carrier liquid,
A conductive pipe provided with an inlet for injecting the recovered carrier liquid and an outlet for discharging the carrier liquid from which the toner solids have been removed, and a conductive roller arranged with a radial gap inside the conductive pipe With
The conductive pipe has a radial gap between the conductive roller and the conductive roller in the circumferential direction from the inlet located upstream in the rotational direction of the conductive roller to the outlet located downstream. And the shape of the recovery carrier liquid formed on the surface of the conductive roller is limited by the gap from the inlet side for injecting the recovery carrier liquid to the outlet side for discharging the recovery carrier liquid. Move
It is configured so that the recovery carrier liquid does not leak from both sides in the axial direction by sealing the radial gap on both sides of the conductive pipe,
The bias voltage in the direction in which the residual toner solid content moves to the surface of the conductive roller is set between the conductive pipe and the conductive roller over substantially the entire time from when the recovered carrier liquid is injected and extracted. To sufficiently deposit the residual toner solids on the surface of the conductive roller,
A blade having sufficient elasticity to accumulate carrier liquid while allowing toner solid matter accumulated on the surface of the conductive roller to pass therethrough is provided on the downstream side in the rotating direction of the conductive roller , and the conductive pipe and the conductive roller are provided. The surface of the conductive roller is arranged at a position on the circumference of the conductive roller not covered by the conductive pipe , and is arranged so as to close the radial gap between the conductive roller and the downstream side. Provided with a collection blade to collect the residual toner solids deposited on the
Carrier liquid recycling equipment consisting of The carrier liquid recycling apparatus according to claim 1, wherein the carrier liquid recycling apparatus is configured to inject a recovered carrier liquid from the discharge port located downstream in the rotation direction of the conductive roller.   The carrier liquid recycling apparatus according to claim 1, wherein a release layer is provided on the surface of the conductive roller to prevent toner solids from adhering to the surface of the conductive roller.   The carrier liquid recycling apparatus according to claim 1, wherein foreign substances other than toner solids are previously removed from the recovered carrier liquid by a filter before injecting the recovered carrier liquid to the inlet side.   The carrier liquid recycling apparatus according to claim 1, wherein the recovered carrier liquid is configured to be heated before or after being injected into the inlet side.

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