JP2001092321A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device that can recycle toner liquid which is collected by a cleaning unit and remains on an image carrier to a developing device again. SOLUTION: A cleaning roller 6 abuts on an image carrier B. The diameter of the cleaning roller 6 gradually becomes smaller toward end parts. Toner liquid collected by the cleaning roller 6 flows toward the end parts whose diameters are small. A squeezing roller 8, which is installed at the tip part of the cleaning roller, crosses the outermost periphery of the cleaning roller 6, comes in parallel to the shaft of the cleaning roller 6 and peels off toner liquid from the cleaning roller 6. Toner which is peeled off is delivered to a tube 10 extending to a developing device by a delivery means 9 which is supported by the cleaning roller 6 and is driven by the rotation of the cleaning roller 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus equipped with a wet developing device for developing an electrostatic latent image with liquid toner.

[0002]

2. Description of the Related Art Developing apparatuses employed in image forming apparatuses are roughly classified into dry developing apparatuses and wet developing apparatuses. The wet developing device using the liquid toner has an advantage that a high resolution can be obtained because the toner particles are finer than the dry developing device using the powder toner.

A liquid toner used in a wet developing device is a toner in which charged granular toner is dispersed in a carrier liquid. When such a liquid toner is supplied to the surface of an image carrier, the toner is electrophoresed. Then, it adheres to the electrostatic latent image to be visualized. More specifically, for example, Isopar_L (registered trademark: Ex)
a liquid toner in which a toner composed of carbon black or the like coated with a resin is dispersed in a carrier liquid composed of an aliphatic hydrocarbon such as xon Corporation). An electrostatic latent image is supplied by supplying the liquid toner to the surface of the image carrier by supplying the liquid toner to the opposing electrodes arranged at equal intervals on the surface and utilizing the electrophoresis phenomenon of the charged toner in the carrier liquid. Is developed.

Here, an image forming apparatus using a conventional wet developing device will be described. FIG. 3 is a configuration diagram of an image forming apparatus using a conventional wet developing device.

In FIG. 3, an image carrier B on which an electrostatic latent image is formed is rotatably supported by the image forming apparatus main body 100. On the outer periphery of the image carrier B, a cleaning roller 10 for removing toner remaining on the outer peripheral surface of the image carrier B
2, a cleaning blade 103, a static eliminator 104 for removing the electrostatic latent image charge remaining on the image carrier B, a charger 105 for uniformly charging the image carrier B, and an electrostatic latent image on the image carrier B. An exposure optical system 106 for forming an image and a wet developing device 101 for developing an electrostatic latent image into a visible image are sequentially arranged along the rotation direction of the image carrier B.

[0006] Inside the housing of the developing device 101,
A developing roller 109 that stores the liquid toner A and supplies the liquid toner A to the outer peripheral surface of the image bearing member B to make the electrostatic latent image visible as a toner image; and a thinning blade pressed against the developing roller 109. 110, a supply roller 111 for supplying the liquid toner A to the developing roller 109 is provided.
As illustrated, the developing roller 109 and the supply roller 1
11 rotates in the rotation direction opposite to that of the image carrier B.

As described above, the cleaning unit 112 includes the cleaning roller 102 that is in pressure contact with the image carrier B and the cleaning blade 103 that is also in contact with the image carrier B and has elasticity. A waste toner box 117 for storing waste toner liquid collected from the body B is provided below the cleaning unit 112.

A cassette 113 containing a transfer material C is disposed below the main body 100 of the image forming apparatus. Further, at a position facing the development surface of the image carrier B,
A transfer roller 114 for transferring the toner image on the image carrier B to the transfer material C is provided. Further, a separation device 115 for separating the transfer material C from the image carrier B, and a toner image
A fixing device 116 for fixing the toner image is sequentially arranged.

The image forming apparatus 100 thus configured
Will be described below. When image formation is started, the surface of the image carrier B is uniformly charged, and an electrostatic latent image is formed on the image carrier B by the exposure optical system 106. When the supply roller 111 partially immersed in the liquid toner A rotates, the developing roller 10 is rotated.
9 is supplied with the liquid toner A. Developing roller 10
The liquid toner A supplied to 9 is supplied to the surface of the image carrier B by the rotation of the developing roller 109. This allows
The electrostatic latent image formed on the image carrier B is visualized as a toner image, and is transferred to the transfer material C by the transfer roller 114. Thereafter, the transfer material C is separated from the image carrier B by the separation device 115 and is conveyed to the fixing device 116, where the toner image is fixed and discharged.

Further, the toner liquid remaining on the image carrier B is supplied to the cleaning roller 102 and the cleaning blade 10.
3 and is stored in a waste toner box 117 disposed below the cleaning unit 112. When the toner liquid in the waste toner box 117 is stored to some extent, it is disposed of by a user or a service person. Further, the residual electrostatic latent images on the image carrier B are removed by the neutralizer 104, respectively.

[0011]

In such a conventional image forming apparatus, liquid toner is supplied to the outer peripheral surface of the image carrier by a developing roller and toner moving means, and the liquid toner on the image carrier is transferred. Although the transfer is performed on the transfer material by the means, for example, in the non-image area, the transfer is not performed on the transfer material, so that all of the liquid toner supplied on the image carrier is transferred to the transfer material. Instead, the liquid toner remaining on the image carrier is collected by a cleaning roller or a cleaning blade of a cleaning unit in a post-transfer process, and the collected toner liquid is stored in a waste box. Then, since the toner liquid in the waste box is disposed by a user or a service person, a process and cost for the disposal are required. In addition, in consideration of the environment, the manufacturer must take responsibility for the disposal of the toner liquid, and requires equipment for processing.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus which can recycle a toner liquid remaining on an image carrier recovered by a cleaning unit to a developing device.

[0013]

In order to solve the above-mentioned problems, an image forming apparatus according to the present invention supplies an image carrier on which an electrostatic latent image is formed, and a liquid toner to the image carrier. A developing roller that visualizes the electrostatic latent image to form a toner image, a supply roller that supplies liquid toner to the developing roller, and a toner in the liquid toner that is supplied to the image carrier. A toner moving unit that electrically moves the toner to the image carrier side, and a cleaning unit that removes toner remaining on the outer peripheral surface of the image carrier and uses the cleaning unit as liquid toner to be supplied to the developing roller again; The toner liquid not transferred onto the transfer material and remaining on the surface of the image carrier is collected by a collecting means and supplied to the developing device again.

With this configuration, it is possible to realize an image forming apparatus capable of recycling the toner liquid remaining on the image carrier recovered by the cleaning unit to the developing device again.

[0015]

According to the first aspect of the present invention, an image carrier on which an electrostatic latent image is formed, and a liquid toner is supplied onto the image carrier to visualize the electrostatic latent image. A developing roller for forming a toner image by forming a toner image, a supply roller for supplying liquid toner to the developing roller, and electrically moving toner in the liquid toner supplied to the image carrier toward the image carrier. And a cleaning unit that removes toner remaining on the outer peripheral surface of the image carrier and uses it again as liquid toner to be supplied to the developing roller. The toner liquid remaining on the surface of the body was collected by a collecting means and supplied to the developing device again.

[0016] According to a second aspect of the present invention, the collection means includes:
The cleaning device includes a cleaning roller that comes into contact with the image carrier and gradually decreases in diameter toward the end, a squeeze roller that comes into contact with the end of the cleaning roller, and a delivery unit that delivers the toner liquid to the developing device.

With this configuration, it is not necessary to discard the waste toner liquid, and high image quality with less cleaning unevenness can be obtained.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an image forming apparatus according to an embodiment of the present invention, and FIG. 2 is a configuration diagram of a cleaning unit of the image forming apparatus.

In FIG. 1, an image carrier B on which an electrostatic latent image is formed is rotatably supported by the image forming apparatus main body 1. An organic photoconductor (OPC), amorphous silicon (а-Si) or selenium (S)
e) A photosensitive receiving layer of the type is applied. In the present embodiment, the image carrier B has a drum shape, but may have a belt shape.

On the outer periphery of the image carrier B, a cleaning roller 6, a cleaning blade 7, and a delivery unit 9 (which remove toner remaining on the outer peripheral surface of the image carrier B and are recycled to the developing device 15 again) 2) and a light-emitting diode, etc., and a static eliminator 12 that removes the electrostatic latent image charge remaining on the image carrier B after the removal of the residual toner by light irradiation. An exposure optical system 14 for turning on / off a laser based on information from a host computer to form an electrostatic latent image on the image carrier B;
A wet developing device 15 is provided for transferring the liquid toner A contributing to development to a portion of the electrostatic latent image to develop the electrostatic latent image into a visible image. 11 is a film.

Liquid toner A is stored inside the developing device 15. Further, a developing roller 2 for supplying the liquid toner A to the outer peripheral surface of the image carrier B and causing the electrostatic latent image formed on the image carrier B to appear as a toner image is provided to partially protrude outside. Have been. Further, a supply roller 4 for supplying the liquid toner A to the developing roller 2 is disposed at a position where the supply roller 4 is partially immersed in the liquid toner A. Liquid film forming means 3 is arranged on the outer peripheral surface of the developing roller 2. Then, as shown, the developing roller 2 and the supply roller 4 rotate in the opposite direction to the image carrier B, but may rotate in different directions.

The developing roller 2 is formed of a conductive member. The developing roller 2 is connected to a power source for applying a voltage at a level between the charging potential of the image carrier B and the charge extinction potential. Further, the image carrier B is set to the ground potential. Thus, when a voltage is applied to the developing roller 2 by the power supply, an electric field is formed between the developing roller 2 and the image carrier B.

A cassette 18 containing a transfer material C is provided below the image forming apparatus main body 1. The toner image formed on the image carrier B is placed at a position facing the development surface of the image carrier B with the transfer material C interposed therebetween.
A transfer roller 19 for transferring the image to the printer is provided.

Further, at the rear of the transfer roller 19 in the transport direction, a separation device 20 for gradually reducing the transfer material C by corona discharge and separating the transfer material C from the image carrier B, and a separation device 20
A fixing device 21 for fixing the toner image transferred to the transfer material C separated from the image carrier B by the above-described method is sequentially arranged. Then, the toner image is fixed on the transfer material C by the pressure and heat when passing through the inside of the fixing device 21.

In FIG. 2, the cleaning roller 6 in contact with the image carrier B has the largest diameter near the center of the image carrier B, and the diameter gradually decreases toward the end.
The squeeze roller 8 is in contact with the outermost portion. Reference numeral 9 denotes a delivery unit including rotating blades that rotate following the rotation shaft 6a of the cleaning roller 6, and delivers the toner liquid to the developing device 15 through the tube 10.

The operation of the thus configured image forming apparatus will be described below. When image formation is started, first, as a charging step, corona discharge is performed by a charger 13 connected to a high-voltage power supply, and the surface of the image carrier B is uniformly charged. Next, in the exposure step, the laser of the exposure optical system 14 is turned on / off by information sent from the host computer, and the charge on the surface of the image carrier B that is rotated in the circumferential direction partially disappears. An electrostatic latent image is formed.

In the subsequent development step, the supply roller 4 partially immersed in the liquid toner A rotates to supply the liquid toner A to the surface of the development roller 2. And
The liquid toner A adhered to the surface of the developing roller 2 has an arbitrary liquid film thickness formed on the surface of the developing roller 2 by the liquid film forming means 3.

When a voltage is applied to the developing roller 2 by a power supply, an electric field is formed between the developing roller 2 and the image carrier B. When the liquid toner A held on the outer peripheral surface of the developing roller 2 reaches the developing section, as the positive charges charged on the surface of the image carrier B approach, the surface of the liquid toner A becomes negative by electrostatic induction. It is charged and attracted to the image carrier B. In this state, when the gap with the image carrier B further narrows, the surface of the liquid toner A rises, and the tip of the projection adheres to the image carrier B.

Here, if the power supply is set to, for example, about 500 V, the developing roller 2 is located between the developing roller 2 and the low potential (about 100 V) image forming section where the charge on the surface of the image carrier B has disappeared. 2, an electric field directed toward the image carrier B is formed, so that the positively charged toner migrates toward the image forming unit of the image carrier B by the action of such an electric field and is transferred to the image forming unit. Supplied. Further, a high potential (7
(Approximately 00 V) between the non-image forming portion and the image carrier B, an electric field is formed from the image carrier B toward the developing roller 2. And migrates in a direction away from the image non-forming portion and is not supplied to the image non-forming portion.

Thus, the liquid toner A supplied to the developing roller 2 is supplied to the portion of the image carrier B where the electrostatic latent image is formed. Then, the electrostatic latent image formed on the image carrier B is visualized as a toner image. A bias voltage is applied to the supply roller 4 so that the supply roller 4 has the same potential as the developing roller 2.

Next, the transfer material C is conveyed from the cassette 18 to the transfer roller 19. The transfer roller 1 is conveyed to the transfer roller 19 almost simultaneously with the development of the toner image on the image carrier B as described above.
9 is in contact with the image carrier B. Then, the toner image on the image carrier B is transferred onto the transfer material C by applying a predetermined level of transfer bias.

Here, since the transfer material C is a dielectric material, the transfer material C is charged and electrostatically attracted to the image carrier B when a high voltage is applied. Therefore, substantially at the same time as the transfer material C is conveyed to the transfer roller 19, corona discharge is performed by the separation device 20, and the transfer material C is gradually charged. Then, when the transfer material C is completely discharged, the electrostatic attraction between the transfer material C and the image carrier B is reduced, and the transfer material C is separated from the image carrier B by a strainer and its own weight. The separated transfer material C is conveyed to the fixing device 21, where the toner image is fixed and then discharged, thereby completing the image formation.

On the other hand, the toner liquid remaining on the image carrier B without being transferred to the transfer material C has the largest diameter near the center of the image carrier B, and gradually decreases in diameter toward the edges. It is collected by a cleaning roller 6 made of a polyester material having excellent solvent properties. Further, since the toner liquid adhering to the cleaning roller 6 may be transferred to the image carrier B again, a cleaning blade 7 made of a urethane-based material is provided as a subsequent process, and the remaining toner liquid or paper Impurities such as powder are separated from the image carrier B.

The toner liquid collected by the cleaning roller 6 flows toward the end having a smaller diameter, is provided at the outermost end of the cleaning roller 6, intersects the outermost periphery of the cleaning roller 6, and It is separated from the cleaning roller 6 by the squeezing roller 8 provided so as to be parallel to the axis. The peeled toner liquid is delivered to a tube 10 extending to the developing device 15 by delivery means 9 which is supported by the cleaning roller 6 and is driven by the rotation of the cleaning roller 6.

Further, the toner liquid peeled off from the image carrier B by the cleaning blade 7 is applied to the film 11 extending from the cleaning blade 7 to the cleaning roller 6.
And is collected by the end of the cleaning roller 6 and delivered to the developing device 15 by the delivery means 9. Further, the residual electrostatic image on the image carrier B is neutralized by the neutralizer 12. As a result, the image carrier B enters a standby state for new image formation.

As described above, according to the present embodiment, a waste toner box for storing unnecessary waste toner is unnecessary, and the toner liquid remaining on the image carrier without being transferred to the transfer material is reliably collected. Then, it can be recycled to the developing device again.

[0037]

As described above, according to the present invention, the toner liquid remaining on the image carrier can be reliably collected without requiring the positional accuracy of the image carrier and the cleaning roller. Furthermore, since the toner is delivered to the developing device again and used to expose the electrostatic latent image as a toner image, the consumption of the toner liquid can be reduced. Further, since a waste toner box for storing waste toner is unnecessary, it is possible to contribute to downsizing of the image forming apparatus main body, and it is possible to provide an environment-friendly apparatus that does not dispose of the waste toner.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a cleaning unit of the image forming apparatus according to an embodiment of the present invention.

FIG. 3 is a configuration diagram of an image forming apparatus using a conventional wet developing device.

[Explanation of symbols]

 2 developing roller 3 liquid film forming means 4 supply roller 5 cleaning unit 6 cleaning roller 7 cleaning blade 8 squeezing roller 9 delivery means 10 tube 11 film 12 static eliminator 13 charger 14 exposure optical system 15 developing device A liquid toner B image carrier Body C transfer material

Claims (2)

[Claims] An image carrier on which an electrostatic latent image is formed; and a developing roller for supplying a liquid toner onto the image carrier to visualize the electrostatic latent image to form a toner image. A supply roller for supplying liquid toner to the developing roller, toner moving means for electrically moving toner in the liquid toner supplied to the image carrier toward the image carrier, and an image carrier. A cleaning unit that removes the toner remaining on the outer peripheral surface of the toner and uses it as liquid toner to be supplied to the developing roller again. An image forming apparatus which collects the toner by means and supplies it to the developing roller again. 2. The image forming apparatus according to claim 1, wherein the collection unit contacts the image carrier.
2. The image forming apparatus according to claim 1, further comprising a cleaning roller having a diameter gradually reduced toward an end, a squeezing roller in contact with the end of the cleaning roller, and a delivery unit for delivering the toner liquid to the developing device. apparatus.