JP2009163065A - Liquid toner fixing device, liquid-developing electronic printing machine and liquid toner fixing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid toner fixing device, a liquid-developing electronic printing machine and a liquid toner fixing method for obtaining a printed object of higher quality. <P>SOLUTION: The liquid toner fixing device is configured to transfer a toner image that was developed by transferring the liquid toner with charged toner dispersed in liquid carrier onto a photoreceptor, to a printing object S, and then, to fix the toner in the liquid toner transferred to the printing object S to the printing object S. The liquid toner fixing device includes: a toner fixing means 8 for fixing the tonerin the liquid toner that was transferred to the printing object S, on the printing object; and carrier removing means 5 to 7 disposed on the upstream side of the toner fixing means 8 in the conveying direction of the printing object S, for removing the carrier in the liquid toner transferred onto the printing object S by evaporating the carrier. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid developing electronic printer that performs printing using toner dispersed in a liquid carrier, a liquid toner fixing device, and a toner fixing method used therefor.

  Conventionally, an electrostatic latent image formed on a photoreceptor is developed using a liquid toner composed of a charged thermoplastic resin and a dye (pigment, etc.) and dispersed in a liquid developer (carrier). 2. Description of the Related Art Printing machines (hereinafter referred to as liquid developing electronic printers) that perform printing by transferring toner onto the surface of a printing material and fixing the toner in the transferred liquid toner to the printing material have been put into practical use.

  The liquid developing electro-printing machine can be used satisfactorily without causing problems such as toner scattering even if the toner has a significantly smaller particle size than a dry electrophotographic apparatus that does not use liquid toner. There are advantages. Printing with toner with a small particle diameter can improve the quality of the color tone and, in addition, the quality of the printed material (for example, printing paper) can be reflected and the printing quality is greatly improved. There is an advantage.

Such a liquid developing electronic printer generally heats and pressurizes the liquid toner transferred to the printing material by a pair of fixing rollers, thereby evaporating the carrier in the liquid toner on the printing material and melting the toner. And a toner fixing portion for fixing (fixing) the surface of the printed material (for example, see Patent Document 1).
If the liquid toner is heated and pressurized by a pair of fixing rollers as in the technique of Patent Document 1, the toner in the liquid toner is melted by heating on the printed material, and the molten toner is applied to the printed material. Since the toner can be pressed, the fixing surface of the toner on the surface of the printing material is leveled, and a good printing surface can be obtained.
JP 2007-171529 A

Incidentally, in order to form a toner image satisfactorily in a liquid developing electronic printing machine, it is naturally necessary that the toner in the liquid toner does not dissolve in the carrier.
However, when the toner is fixed to the printing material in the liquid developing electronic printing machine, the property that the toner does not dissolve in the carrier is a cause of lowering the fixing property of the toner to the printing material in the toner fixing portion. The present inventors have found that.

That is, since the compatibility between the toner melted by heating and the carrier in the toner fixing unit is very poor, the carrier on the printed material and the melted toner are separated, and the toner may permeate and fix on the printed material. It is inhibited.
Further, as shown in FIG. 8, the toner fixing unit heats and presses the printed material 100 at the nip portion N formed by the pair of fixing rollers 101 and 102, so that the printed material is substantially sealed at the nip portion N, and the heating is performed. Insufficient acceleration of carrier evaporation due to the toner also causes a decrease in toner fixing property to the printed material.

As described above, when the toner fixing property is lowered, the printing quality is lowered, for example, the toner forming the printed pattern is easily peeled off from the printing material.
The present invention was devised in view of the above problems, and a liquid toner fixing device and a liquid developing electronic printer capable of improving a toner fixing property to a printing material and obtaining a higher quality printed material. An object of the present invention is to provide a liquid toner fixing method.

  In order to achieve the above-mentioned object, the liquid toner fixing device according to the present invention (claim 1) transfers the liquid toner in which charged particulate toner is dispersed in a liquid carrier onto the photosensitive member. A liquid toner fixing device that transfers a developed toner image to a printing material and fixes the toner in the liquid toner transferred to the printing material to the printing material, wherein the liquid transferred to the printing material Toner fixing means for fixing the toner of the toner to the substrate, and upstream of the toner fixing means in the transport direction of the substrate, the liquid toner transferred to the substrate It has a carrier removing means for evaporating and removing the carrier.

Preferably, the toner fixing unit is configured to fix the toner in the liquid toner to the printing material by heating and pressurizing the printing material to which the liquid toner has been transferred ( Claim 2).
As a result, the toner is melted by heating and pressurizing the toner, and the melted toner can be pressed against the printing material, so that the unevenness of the toner is leveled and the toner is effectively fixed to the printing material. And a good printing surface can be obtained.

In addition, it is preferable that the carrier removing unit includes a substrate temperature increasing device for increasing the temperature of the material to which the liquid toner is transferred.
By elevating the temperature of the substrate, the evaporation of the liquid carrier can be promoted and effectively removed. Further, the printed material can be preheated before being carried into the toner fixing unit, and the heating amount in the toner fixing unit can be reduced.

In addition, it is preferable that the printing material temperature increasing device includes a flash light irradiation device that heats the printing material by irradiating the printing material to which the liquid toner has been transferred with flash light.
By raising the temperature of the substrate, the liquid carrier can be evaporated and effectively removed. In addition, the temperature of the printed material can be instantaneously raised by the flash, and the temperature of the printed material can be prevented from being excessively increased by over-irradiation of the heat source.

Further, the substrate temperature increasing device is provided on the upstream side in the sheet conveying direction with respect to the flash irradiation device, and includes a substrate preheating means for preheating the substrate to which the liquid toner has been transferred. (Claim 5).
In general, the flash irradiation device is relatively poor in energy efficiency for increasing the temperature of the printed material to be consumed, and causes an increase in running cost. However, before the temperature of the printed material is increased by the flash irradiation device, it is more energy efficient. By preheating the printed material with the good printed material preheating means, the output power of the flash irradiation device can be reduced, and the running cost of the entire device can be reduced.

Further, the carrier removing means preferably has a blower disposed between the toner fixing means and the substrate temperature increasing device for promoting evaporation of the carrier on the substrate (claim). Item 6).
Evaporation of water vapor and carriers in the printing material can be further promoted by causing an air flow to act on the heated printing material.

The flow direction of the air flow generated by the blower is not particularly limited, but it is preferable to dispose the blower so that the air pressure in the vicinity of the printing surface of the printing material is negative with respect to the surroundings. For example, a blower may be disposed in a direction in which air in the vicinity of the printing material is sucked, or a layered air flow may be blown from the side with respect to the printing material.
By setting the air pressure in the vicinity of the printing surface of the substrate to be negative with respect to the surroundings, it is possible to further promote the evaporation of the carrier from the substrate.

In addition, the mounting portion on which the printed material is placed has an opening-type conveying belt having an opening, and the printed material is conveyed on the carrier removing means while being placed on the conveying belt with the opening. It is preferable to be configured as (Claim 7).
The opening-conveying belt is preferably a so-called suction belt configured such that a mounting belt having a plurality of openings is intermittently continued in the width direction of the printing material.

According to this, since the contact area between the printing medium and air is increased as compared with a case where the sheet is conveyed on a simple endless belt, it is possible to further promote evaporation of water vapor and liquid carrier in the printing medium.
In addition, a chain gripper that transports the substrate while gripping an end portion of the substrate, and the substrate is configured to be transported by the carrier removing unit while being gripped by the chain gripper. Preferred (claim 8).

  As a result, the contact area between the printing medium and air further increases, so that evaporation of water vapor and liquid carrier in the printing medium can be further effectively promoted. Further, since the opposite surface (back surface) of the toner fixing surface is not in contact with the chain gripper which is the conveying means for the printing material, even when the back surface image is softened due to the temperature rise, image fringing such as rubbing is caused. There is no fear of producing.

In addition, the carrier removing unit has a suction unit that is disposed so as to face the substrate temperature-elevating device across the conveyance path of the substrate, and sucks air from the substrate side. (Claim 9).
By sucking air from the opposite side across the conveyance path of the printing material, moisture and liquid carrier in the printing material and its vapor are sucked to the back surface side, and toner fixing can be further promoted.

  According to a tenth aspect of the present invention, an electrostatic latent image is formed on the liquid toner fixing device according to any one of the first to ninth aspects and the charged liquid toner. A developing unit that develops the toner by transferring it onto a photoconductor, and an intermediate transfer member that is disposed between the photoconductor and the substrate to transfer the liquid toner on the photoconductor to the substrate. It is characterized by having.

  The liquid toner fixing method according to the present invention (claim 11) is a method for printing a toner image developed by transferring a liquid toner in which charged particulate toner is dispersed in a liquid carrier onto a photoconductor. A liquid toner fixing method in which the toner in the liquid toner transferred to the substrate is fixed to the substrate, and the toner in the liquid toner transferred to the substrate is A toner fixing step for fixing to the substrate, and a carrier removing step for evaporating and removing the carrier of the liquid toner transferred to the substrate to be executed prior to the toner fixing step. It is characterized by that.

In the toner fixing step, it is preferable that the toner is fixed to the printing material by heating and pressurizing the printing material to which the toner has been transferred.
Preferably, the carrier removing step includes a substrate temperature increasing step for increasing the temperature of the material to which the liquid toner has been transferred.

Further, it is preferable that the substrate temperature increasing step includes a flash light irradiation step of increasing the temperature of the substrate by irradiating the substrate to which the liquid toner has been transferred with flash light. .
Preferably, the substrate temperature raising step includes a material preheating step for preheating the material to which the liquid toner is transferred prior to the flash irradiation step. ).

In addition, it is preferable that the carrier removing step includes an air blowing step for blowing air on the substrate between the execution of the substrate temperature increasing step and the execution of the toner fixing step. (Claim 16).
In the carrier removing step, it is preferable that the printed material is transported in a state of being placed on a transport belt with an opening having an opening in the placing portion.

In the carrier removing step, it is preferable that the printed material is conveyed in a state of being gripped by a chain gripper that grips an end portion of the printed material.
The carrier removing step is preferably performed at the same time as the substrate temperature raising step, and has a suction step for sucking air from the opposite side across the conveyance path of the substrate (Claim 19). .

  According to the liquid toner fixing device, the liquid toner fixing method, and the liquid developing electronic printer according to the present invention, the liquid carrier, which is an impediment to toner fixing, is removed by evaporating in advance. The fixing property of the toner is improved, and a higher quality printed matter can be obtained.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. 1 to 4 are all for explaining the liquid toner fixing device and the liquid developing electronic printer according to the first embodiment of the present invention, and FIG. 2 is a schematic side view showing a schematic configuration of the liquid developing electronic printing machine, FIG. 3 is a schematic diagram showing the configuration of the developing unit, and FIG. 4 is a flowchart showing an operation procedure of the liquid developing electronic printing machine. .

(overall structure)
As shown in FIG. 2, the liquid developing electronic printing machine 50 includes a paper feeding unit 51, a printing unit 52, and a paper discharge unit 53. The paper feeding unit 51 is configured to feed the printing sheets S, which are sheets, as the printed material one by one from the paper feeding tray 51A to the printing unit 52 that forms part of the sheet conveyance path 10. The printing unit 52 is configured to perform printing on the fed print sheet S, and the paper discharge unit 53 discharges the print sheet S printed by the print unit 52 to the paper discharge tray 53A. It is configured. A caster 50 </ b> A is attached to the lower part of the liquid developing electronic printing machine 50, so that the liquid developing electronic printing machine 50 can be easily moved.

Note that a sheet conveyance path 10 shown in FIG. 2 indicates a path (conveyance route) through which the print sheet S is conveyed. In this embodiment, after passing the nip portion N1 from the paper feed tray 52A, the nip portion N2 is passed. It is configured to pass through to the paper discharge tray 53A.
Further, the liquid developing electronic printer 50 is connected to a control device 60 having a computer, a display device and an input terminal by signal lines so that each part of the liquid developing electronic printer 50 can be controlled by a control signal. It is configured. The control device 60 may be configured to be built in the liquid developing electronic printer 50.

(Schematic configuration of toner transfer unit)
The liquid developing electronic printer 50 according to the present embodiment is configured to be able to perform process color printing, and the printing unit 52 includes K (black), C (blue), M (red), and Y (yellow). ) Four development units 1A to 1D corresponding to the respective process colors are provided.
The printing unit 52 includes developing units 1A to 1D, an intermediate transfer member 2, a blade unit 3, a backup roller 4, an oven (substrate preheating means and substrate temperature raising device) as a substrate preheating device, and carrier removal. The apparatus includes a flash irradiation device (carrier removal means, substrate temperature raising device) 6, a fan (blower) 7, a pair of heating rollers (toner fixing means) 8, and a conveyor belt 9.

Each of the developing units 1A to 1D is arranged around the intermediate transfer member 2, and forms an electrostatic latent image on the photosensitive member based on the image data transmitted from the control device 60. The liquid toner 20 (see also FIG. 3) is transferred from the photosensitive member 11 to the intermediate transfer member 2 at a corresponding position. The detailed configuration of each of the developing units 1A to 1D will be described later.
The liquid toner 20 is obtained by dispersing and blending toner particles formed of a thermoplastic material loaded with a charge and a coloring material (pigment or dye) in a liquid carrier. In this solution, toner particles having an average particle diameter of about 1 μm are contained in a weight ratio of about 20 to 40 percent.

The intermediate transfer body 2 and the backup roller 4 are in contact with each other, and a nip portion (transfer position) N1 is formed at the contact portion.
The outer peripheral surface of the intermediate transfer body 2 is made of, for example, urethane conductive rubber, conductive resin, or the like, and an intermediate transfer bias of about −200 to −300 V, for example, is applied to the intermediate transfer body 2. Yes.

An image of the liquid toner 20 is transferred from the intermediate transfer body 2 to the print sheet S at the nip portion N1.
In addition, a blade unit 3 is disposed around the intermediate transfer body 2 at a position downstream of the nip portion N1 in the rotation direction of the intermediate transfer body 2, and after the transfer to the printing sheet S, the intermediate transfer body 2 is provided. The liquid toner 20 remaining on the peripheral surface is scraped off with a blade and can be removed.

  On the other hand, the backup roller 4 is arranged to apply a pressure to the intermediate transfer body 2 at a predetermined pressure, for example, about 1 to 13 kg / cm, and between the intermediate transfer body 2 and the backup roller 4. It has a function of pressing the conveyed printing sheet S against the intermediate transfer body 2. Further, for example, a transfer bias of about −800 V is applied to the backup roller 4, and the transfer of the liquid toner 20 from the intermediate transfer body 2 to the print sheet S is promoted.

(Configuration around the toner fixing unit)
Hereinafter, an apparatus configuration relating to fixing of toner onto the print sheet S, which is the most characteristic part of the present invention, will be described.
As shown in FIG. 1, an oven 5, a flash irradiation device 6, a fan 7, and a pair of heating rollers 8 are disposed along the sheet conveyance path 10 on the downstream side of the nip portion N 1 between the intermediate transfer member 2 and the backup roller 4. They are arranged in order.

Further, the transport belt 9 is constituted by an endless belt (endless belt) that transports the print sheet S placed thereon. Here, two transport belts 9 are disposed below the oven 5 and the flash irradiation device 6. .
Here, the oven 5 is constituted by a halogen heater using a halogen lamp as a heat source, and the print sheet S is brought into an atmosphere of about 130 to 150 degrees Celsius before the print sheet S passes through the flash irradiation device 6. It is configured to expose and raise the temperature. This is because if the apparatus is stopped by heating at an excessively high temperature in the oven 5, there is a possibility that it will be ignited by residual heat if there is a printed material such as paper that has entered the vicinity of the oven 5.

In addition, as a to-be-printed material preheating means, you may comprise so that infrared light or a hot air may be irradiated not only with a halogen heater.
The flash irradiation device 6 is constituted by a xenon flash lamp. As shown in FIG. 1, the flash irradiation device 6 instantaneously flashes on the surface of the print sheet S in accordance with the timing when the printing sheet S is conveyed below the flash irradiation device 6. Is supposed to be irradiated. Further, the flash irradiation device 6 is set to output a flash so as to instantaneously raise the temperature of the print sheet S to about 140 to 200 degrees Celsius.

The fan 7 is disposed so as to generate an air flow in a direction away from the surface of the print sheet S on which the toner is transferred (the direction indicated by the arrow Q in FIG. 1), and is driven by a motor (not shown). It has become. As a result, the air pressure on the fan 7 side around the sheet conveying path 10 becomes negative with respect to the surroundings.
The flash irradiation timing and output of the flash irradiation device 6 and the driving of the fan 7 are controlled by the control device 60.

Further, the fan 7 may be arranged so as to form a layered air flow from the side of the sheet conveying path 10 to form a negative pressure on the upper surface side of the printed sheet S.
The heating roller 8 is composed of a pair of rollers 8A and 8B. The roller 8A is a metal roller having a conductive fluorine coating on the surface, and the surface temperature is set to, for example, about 170 degrees Celsius by a heating source (not shown). On the other hand, the roller 8B is formed of conductive urethane rubber.

An electric field is formed between the rollers 8A and 8B so that the toner in the carrier transferred onto the print sheet S moves toward the roller 8A. Here, the roller 8A is grounded and a charge having the same polarity as the toner is applied to the roller 8B.
The pair of rollers 8A and 8B are in contact with each other, and a nip portion N2 that can press the print sheet S with the rollers 8A and 8B when the print sheet S passes is formed.

(Development unit configuration)
Here, a detailed configuration of each of the developing units 1A to 1D will be described. Each of the developing units 1A to 1D is configured in the same manner except for the color of the toner and the arrangement position with respect to the intermediate transfer body 2. Therefore, one developing unit (hereinafter referred to as developing unit 1 unless otherwise specified). Only) will be described, and a description of each of the developing units 1A to 1D will be omitted.

The developing unit 1 includes a photosensitive drum (photosensitive member) 11, a cleaning unit 12, a static eliminator 13, a photosensitive member charging device 14, an exposure device 15, and a developing device 16.
On the peripheral surface of the photosensitive drum 11, a photosensitive layer 11A formed including a photosensitive agent such as amorphous silicon (a-Si) or a photosensitive polymer is formed.
The photosensitive drum 11 is in contact with the intermediate transfer member 2 at the nip portion N3, and is configured to transfer the liquid toner 20 on the photosensitive drum to the intermediate transfer member 2 side.

On the other hand, around the photosensitive drum 11, a cleaning unit 12, a static eliminator 13, a photosensitive member charging device 14, an exposure device 15 and a developing device 19 are sequentially arranged along the rotation direction of the photosensitive drum 11 starting from the nip portion N3. It is disposed opposite to the photosensitive layer 11A.
The cleaning unit 12 includes a cleaning roller 12A, blades 12B and 12C, and a toner discharge port 12, and removes the liquid toner 20 remaining on the peripheral surface of the photoreceptor 11 to remove a toner collection path (not shown). It is configured to discharge.

More specifically, the cleaning roller 12A is arranged so as to rotate in the driven direction in contact with the photosensitive drum 11, and collects the liquid toner 20 remaining on the peripheral surface of the photosensitive drum 11. Yes.
Further, the blade 12B is a rectangular plate formed of an elastic material, and is disposed so that one long side portion is in contact with the peripheral surface of the photosensitive drum 11, and cannot be removed by the cleaning roller 12A. The liquid toner 20 on the circumferential surface of the photosensitive drum 11 is scraped off to completely remove the liquid toner 20 from the photosensitive drum 11.

The blade 12C is a rectangular plate made of an elastic material like the blade 12B, and is arranged so that one long side portion is in contact with the peripheral surface of the cleaning roller 12A. Then, the liquid toner 20 adhering to the peripheral surface of the cleaning roller 12A is scraped off and removed.
The liquid toner 20 removed from the photosensitive drum 11 is discharged from the toner discharge port 12.

The static eliminator 13 has a function of erasing charges remaining on the photosensitive layer 11 </ b> A of the photosensitive drum 11.
The photosensitive member charging device 14 includes a plurality of (three in this case) chargers of a non-contact discharge type such as a corotron type or a scoroton type along the photosensitive drum 11. The layer 11A has a function of uniformly charging, for example, about 500V.

The exposure device 15 is composed of a light emitting device (that is, an LED array) in which light emitters (here, LEDs) are arranged in a rod shape along the axial direction of the photosensitive drum 11, and image data sent from the control device 60. Based on the above, each LED is caused to emit light.
In other words, the light from the exposure device 15 is irradiated on the surface of the photosensitive layer 11A that is uniformly charged by the photosensitive member charging device 14, whereby the photosensitive layer 11A is uncharged in the light irradiation portion, and the photosensitive layer. An electrostatic latent image based on image data can be formed on 11A.

Note that the light emitting device may be configured to form an electrostatic latent image by scanning a semiconductor laser or the like based on image data instead of the LED array.
The developing device 16 includes an anilox roller 21, a leveling roller 22, a developing roller 23, a toner charger 24, a cleaning roller 25, blades 26 and 27, a toner supply port 28, and a liquid toner storage unit 29. The liquid toner 20 is transferred to the portion of the photosensitive drum 11 where the electrostatic latent image is formed.

Liquid toner 20 is stored in the toner storage unit 29, and the liquid toner 20 is appropriately supplied from the toner supply port 28 so that a part of the anilox roller 21 is immersed in the liquid toner 20. .
The anilox roller 21 is a metal roller, and a concave portion (cell) suitable for supplying the liquid toner 20 with a desired film thickness is formed on the entire surface of the anilox roller 21. The anilox roller 25 is driven to rotate in the same direction as the photosensitive drum 11 (the direction of the arrow in FIG. 3).

The blade 27 is formed of a plate-like high-density polyethylene, and the tip of the blade 27 is in contact with the peripheral surface of the anilox roller 21 and scrapes off the liquid toner 20 adhering to the peripheral surface of the anilox roller 21 to surround the anilox roller 21. The film thickness of the liquid toner 20 on the surface is set to a desired film thickness.
The leveling roller 22 is made of urethane rubber. The leveling roller 22 is disposed between the anilox roller 21 and the developing roller 23 and is in contact with each of the anilox roller 21 and the developing roller 23.

Further, the leveling roller 22 is configured to rotate in a direction (direction of an arrow in FIG. 3) in which the peripheral surfaces of the leveling roller 22 advance in the same direction at the contact point with the anilox roller 21.
The developing roller 23 is made of conductive rubber and is disposed so as to contact the photosensitive drum 11 and form a nip portion N4. Further, the developing roller 23 is configured to rotate in a direction in which the peripheral surface of the photosensitive drum 11 and the peripheral surface of the developing roller 23 advance in the same direction (the direction of the arrow in FIG. 3) at the nip portion N4. In other words, the developing roller 23 is configured to rotate in a direction in which the peripheral surfaces thereof advance in opposite directions at the contact point with the leveling roller 22.

The speed of the peripheral surface of the developing roller 23 is configured to rotate at the same speed as the rotational speed of the peripheral surface of the photosensitive drum 11.
As described above, the conductive developing roller 23 and the photosensitive drum 11 are in contact with each other at the nip portion N4, so that the toner charged from the peripheral surface of the developing roller 23 to the portion where the electrostatic latent image of the photosensitive drum 11 is formed. The liquid toner 20 containing particles is transferred and developed.

The developed liquid toner 20 on the peripheral surface of the photosensitive drum 11 is transferred to the intermediate transfer member 2 at the nip portion N3, and a toner image is formed on the peripheral surface of the intermediate transfer member 2.
The toner images respectively formed by the developing units 1A to 1D are positions that overlap with the same position on the peripheral surface of the intermediate transfer body 2, and are synchronized with the timing at which the print sheet S passes through the nip portion N1. The toner image is formed at a position where the toner image is transferred from the intermediate transfer body 2 to an appropriate position on the print sheet S.

The toner charger 24 is close to the peripheral surface of the developing roller 23, is upstream of the nip portion N <b> 4 in the rotation direction of the developing roller 23, and more than the contact surface between the developing roller 23 and the leveling roller 22. It arrange | positions so that it may be located in the rotation direction downstream.
The toner charger 24 is a non-contact discharge type charger such as a corotron type or a scoroton type, and has a function of charging the liquid toner on the developing roller 24.

The cleaning roller 25 is in contact with the developing roller 23 on the downstream side in the rotation direction of the developing roller 23 with respect to the nip portion N4, and removes the liquid toner 20 remaining on the peripheral surface of the developing roller 23 without being transferred to the photosensitive member 3. It is supposed to be.
The blade 26 scrapes off the liquid toner 20 adhering to the peripheral surface of the cleaning roller 25.

(Function and effect)
Since the liquid toner fixing device and the liquid developing electronic printer according to the first embodiment of the present invention are configured in this way, first, in step S100, based on the signal from the control device 60, as shown in FIG. Printing is started, and only one print sheet S is fed from the paper feed tray 51A to the printing unit 52.

In step S110, in the printing unit 53, the development units 1A to 1D change the process color of K (black), C (blue), M (red), and Y (yellow) to the peripheral surface of the intermediate transfer body 2. A toner image in which each corresponding liquid toner 20 is polymerized is formed.
Subsequently, in step S120, the print sheet S fed from the paper feed tray 51A in step S100 passes through the nip portion N1 formed by the intermediate transfer body 2 and the backup roller 4, and the peripheral surface of the intermediate transfer body 2 The liquid toner 20 (toner image) of each color is simultaneously transferred from the toner to the printing sheet S.

In step S130, the printing sheet S is transported in a state of being placed on the transport belt 9 so that the surface to which the liquid toner 20 is transferred is the upper surface, and the surface temperature is about 50 to 110 degrees Celsius by the oven 5. (Printed material preheating step).
In step S140, the flash irradiation device 6 irradiates the print sheet S placed on the conveyor belt 9 with flash light, and the temperature of the image portion (that is, the toner portion) on the surface of the print sheet S is further increased. (Flash exposure step). At this time, the surface temperature of the printing sheet S due to the temperature rise by the flash differs depending on the image line rate on the surface of the printing sheet S, and is 160 degrees Celsius or more in the solid portion (image line rate 100%). The non-image area is not so heated by the flash and the temperature is low, but there is no need to fix the toner, so there is no problem.

Note that step S130 and step S140 correspond to the substrate temperature raising step. From the liquid toner 20 on the printing sheet S whose temperature has been raised in steps S130 and S140, the amount of evaporation of the carrier in the liquid toner 20 is greatly increased by heat.
Further, in step S150, the evaporation of the carrier from the liquid toner 20 on the print sheet S heated in steps S130 and S140 is further promoted by the negative pressure formed by the fan 7, and transferred onto the print sheet S. The carrier in the liquid toner 20 is removed. That is, here, steps S130 to S150 correspond to a carrier removal step.

  In step S150, when the print sheet S passes through the lower portion of the fan 7 and reaches the nip portion N2 of the heating roller 8, as step S160, the liquid toner on the print sheet S is generated by an electric field formed between the rollers 8A and 8B. The toner of 20 is attracted to the heated roller 8A side. The nip portion N2 is pressurized by the rollers 8A and 8B and heated by the roller 8A. As a result, after the toner is melted, it is pressed against the print sheet S and fixed (fixed) on the print sheet S (toner fixing step).

In step S170, the print sheet S on which the toner is fixed is cooled while being conveyed through the paper discharge unit 53, and is discharged to the paper discharge tray 53A.
In step S180, the control device 60 determines whether or not a print end condition is satisfied. If the print end condition is not satisfied, the process returns to step S100 to print the next print sheet S. In step S180, if the printing end condition is satisfied, printing is ended as it is.

Note that the print end condition is set by the input terminal of the control device 60 each time.
As described above, according to the liquid toner fixing device, the liquid developing electronic printer, and the liquid toner fixing method according to the first embodiment of the present invention, the print sheet S is pressed and heated by the pair of heating rollers 8. The carrier in the liquid toner 20 is removed by evaporating the carrier, which is an impediment to fixing the toner on the print sheet S, so that the fixability of the toner to the print sheet S is improved and a higher quality printed matter can be obtained. Can do.

In addition, since the toner is heated and melted by the heating roller 8 (roller 8A), and the melted toner can be pressed against the printing material, the unevenness of the toner is leveled, and the toner is effectively fixed to the printing material. be able to. For this reason, the liquid developing electronic printer of the present invention can be suitably applied to small lots (about several thousand sheets) and other types of printing with high quality.
Further, the temperature of the printed sheet S can be instantaneously increased in the sheet conveying line 10 by performing flash irradiation (flash heating). Furthermore, since the temperature of the print sheet S is increased by irradiation with a constant output flash, even when the conveyance speed of the print sheet S slightly varies, the print sheet S can be instantaneously heated with a constant amount of heat.

  However, the flash irradiation device 6 configured using a Xe lamp (xenon lamp) as a light source is generally not good in energy efficiency for increasing the temperature of the printing sheet S. However, before the temperature of the printing sheet S is increased by the flash irradiation device 6, the flash irradiation device 6 is preheated by the oven 5 that is more energy efficient than the flash irradiation device 6. Even if the output is suppressed, the carrier in the liquid toner 20 can be sufficiently evaporated, and the overall energy efficiency can be improved.

Further, since the fan 7 blows air in the direction away from the print sheet S on the downstream side of the oven 5 and the flash irradiation device 6, the liquid toner 20 of the print sheet S heated by the oven 5 and the flash irradiation device 6 is discharged. The vicinity of the transferred surface (printed surface) becomes a negative pressure with respect to the surroundings, and the evaporation of water vapor and carriers in the printed sheet S can be further promoted.
Further, since the toner is heated and melted by the pair of heating rollers 8 and the melted toner can be pressed against the printing surface of the printing sheet S, the unevenness of the toner fixed on the printing sheet S is leveled, The fixing property of the toner to the print sheet S can be improved.

  Further, in the sheet conveyance path 10 from the nip portion N1 formed by the intermediate transfer body 2 and the backup roller 4 to the nip portion N2 formed by the pair of heating rollers 8, the temperature of the printing sheet S is increased to increase the liquid state. It can be effectively removed by promoting the evaporation of the carrier. Further, since the printing sheet S is preheated before passing through the nip portion N2 of the pair of heating rollers 8, the amount of heat applied to the printing sheet S by the pair of heating rollers 8 can be reduced.

[Second Embodiment]
Subsequently, a second embodiment of the present invention will be described. This embodiment is configured in the same manner as the above-described first embodiment except for a part of the configuration, and the description of the same components as those in the first embodiment will be omitted, and will be described using the same reference numerals.
As shown in FIG. 5, in the present embodiment, the configuration of the transport belt (transport belt with opening) 31 and the configuration related to the periphery thereof are different from those of the first embodiment. In the present embodiment, the oven 5 and the fan 7 in the first embodiment are omitted.

As shown in FIG. 6, the conveyor belt 31 includes a plurality of openings 31 </ b> B (mounting belts) 31 having a predetermined interval 31 </ b> C in the width direction of the print sheet S (that is, intermittently). ) It is configured to be in parallel and is configured as an endless belt driven by two belt drive rollers 31D and 31D.
Then, as shown in FIG. 5, the placement belt 31 </ b> A (upper placement belt) driven in the sheet conveyance direction by the drive rollers 31 </ b> D and 31 </ b> D and the placement belt (lower side) driven in the opposite direction of the sheet conveyance direction. The suction fan (suction means) 32 is disposed at a position facing the flash irradiation device 6 across the placement belt 31A.

The suction fan 32 is configured to generate an air flow in a direction indicated by an arrow R in FIG. 5 (a direction away from the print sheet S).
A filter 33 is arranged in the air blowing direction of the suction fan 32 with the lower mounting belt 31A interposed therebetween.
The filter 33 sucks carriers (particularly carriers) evaporated from the printing sheet S.

In this embodiment, since the oven 5 in the first embodiment is omitted, the output of the flash irradiation device 6 is set to be higher than that in the first embodiment.
Further, a suction box may be provided in place of the suction fan 32, and the suctioned by the suction box may be introduced into the filter 33.

  Since the liquid toner fixing device and the liquid developing electronic printer according to the second embodiment of the present invention are configured as described above, the printing sheet S on the conveying belt 31 side through the opening 31B and the interval 31C of the mounting belt 31A. Since the contact area between the surface (hereinafter referred to as the back surface for the sake of convenience) and the outside air increases, the evaporation of carriers and water vapor from the back surface as well as the printed surface of the printing sheet S heated by the flash irradiation device 6. Therefore, the evaporation of the carrier from the printing sheet S can be further effectively promoted.

  Further, since the water vapor and the carrier from the printing sheet S are guided to the filter 33 and adsorbed by the filter 33 along the air flow generated by the suction fan 32, the carrier which is an organic solvent can be prevented from scattering. .

[Modification of Second Embodiment]
Then, the modification of 2nd Embodiment of this invention is demonstrated. Note that the present modification is configured in substantially the same manner as the second embodiment described above, and the description of the same components as those of the second embodiment will be omitted, and will be described using the same reference numerals.

The present modification is different from that of the second embodiment only in that the chain gripper 35 that conveys the print sheet S while holding both side edges instead of the conveyance belt 31 is used.
As shown in FIG. 7, the chain gripper 35 includes two chains 35A and 35A that are endlessly formed by two gears (not shown) and are arranged in parallel.

A plurality of grippers 35B are attached to each chain 35A at equal intervals. The interval between the grippers 35B is set to be shorter than the length of the print sheet S in the sheet conveyance direction.
The gripper 35B is configured to grip the side end portion of the print sheet S. The gripper 35B grips the print sheet S at a predetermined transport position by a gripping mechanism (not shown), and the print sheet S at another predetermined position. The grip is released.

Since the liquid toner fixing device and the liquid developing electronic printer according to the modification of the second embodiment of the present invention are configured as described above, the back surface of the printing sheet S and the outside air are further increased than those of the second embodiment. Therefore, the evaporation of water vapor and liquid carrier in the printing sheet S can be further promoted.
Further, there is an advantage that the evaporation promotion effect by suction by the suction fan 32 or the suction box is further increased.

  Further, when applied to a liquid developing electronic printer capable of printing on both sides of the print sheet S, the toner on the already printed surface (back surface) on which the toner has already been fixed is melted again by the flash light from the flash light irradiation device 6. Even if this occurs, it is possible to avoid inconveniences such as toner on the back surface adhering to the conveying belt.

[Other Embodiments]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, the substrate preheating means (oven 5), the blower (fan 7), and the like in the first embodiment may be appropriately omitted. In addition, each embodiment and modification may be appropriately combined as long as possible. For example, you may make it provide the conveyance belt concerning 2nd Embodiment and its modification in the structure of 1st Embodiment. Moreover, you may comprise by arrange | positioning a filter in the ventilation direction of the air blower in 1st Embodiment.

  Furthermore, in the above-described embodiment, the toner fixing unit is configured to heat and press the printed material by the heating roller. However, the toner fixing unit is not limited to this, and by simply pressing the printed material. A pressure fixing method for fixing toner on the substrate may be applied. Even in this case, it is possible to improve the toner fixability by removing the carrier which is an impediment to toner fixing before fixing the toner.

In the above-described embodiment, a printing sheet that is a sheet is described as an example of the printed material. However, the printed material is not limited to a sheet, and can be printed by a liquid development electronic printing machine. It can be applied to anything. For example, instead of a sheet, continuous printing may be performed using a continuous belt-like paper as a substrate.
The liquid developing electronic printing machine according to the present invention is not limited to the number of printing colors, and may be configured as a printing machine that performs printing of only a single color, or a double-sided printing machine that performs printing on both sides of a printing sheet. You may apply.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram schematically illustrating a main configuration of a liquid toner fixing device, a liquid developing electronic printer, and a liquid toner fixing method according to a first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view illustrating an overall schematic configuration for describing a liquid toner fixing device, a liquid developing electronic printer, and a liquid toner fixing method according to a first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view schematically illustrating a configuration of a developing unit for explaining a liquid toner fixing device, a liquid developing electronic printer, and a liquid toner fixing method according to a first embodiment of the present invention. 1 is a flowchart illustrating a printing procedure for explaining a liquid toner fixing device, a liquid developing electronic printer, and a liquid toner fixing method according to a first embodiment of the present invention. FIG. 5 is a diagram schematically illustrating a main part configuration for explaining a liquid toner fixing device, a liquid developing electronic printer, and a liquid toner fixing method according to a second embodiment of the present invention. FIG. 7 is a perspective view schematically illustrating a transport belt with an opening for explaining a liquid toner fixing device, a liquid developing electronic printer, and a liquid toner fixing method according to a second embodiment of the present invention. FIG. 10 is a perspective view schematically illustrating a chain gripper for explaining a liquid toner fixing device, a liquid developing electronic printer, and a liquid toner fixing method according to a modification of the second embodiment of the present invention. FIG. 5 is a diagram schematically illustrating a fixing roller for fixing a toner, for explaining a related art related to a liquid developing electronic printer.

Explanation of symbols

1, 1A to 1D Developing unit 2 Intermediate transfer body 3 Blade unit 4 Backup roller 5 Oven (Substrate preheating means, Substrate temperature raising device)
6 Flash irradiation device (Substrate preheating means, Substrate heating device)
7 Fan (blower)
8 Pair of heating rollers (toner fixing means)
8A, 8B Roller 9 Conveying belt 10 Sheet conveying path 11 Photosensitive drum (photosensitive member)
11A Photosensitive layer 12 Cleaning unit 12B, 12C Blade 13 Charger 14 Photoconductor charging device 15 Exposure device 16 Developing device 20 Liquid toner 21 Anilox roller 22 Leveling roller 23 Developing roller 24 Toner charger 25 Cleaning roller 26, 27 Blade 28 Toner Supply port 29 Toner storage portion 31A Loading belt 31B Opening 31C Spacing 31D Belt drive roller 32 Suction fan 33 Filter 35 Chain gripper 35A Chain 35B Gripper 50 Liquid developing electronic printer 51 Paper feed portion 51A Paper feed tray 52 Printing portion 53 Paper discharge 53A Paper discharge tray 60 Control device S Print sheet

Claims (19)

The developed toner image is transferred to the substrate by transferring the liquid toner in which the charged particulate toner is dispersed in the liquid carrier onto the photoconductor, and the liquid toner transferred to the substrate is transferred. A liquid toner fixing device for fixing the toner on the substrate,
Toner fixing means for fixing the toner in the liquid toner transferred to the substrate to the substrate;
A carrier removing unit disposed upstream of the toner fixing unit in the transport direction of the substrate and evaporating and removing the carrier of the liquid toner transferred to the substrate. A liquid toner fixing device. The toner fixing means is
2. The liquid according to claim 1, wherein the liquid toner is fixed to the substrate by heating and pressurizing the substrate to which the liquid toner is transferred. Toner fixing device. The carrier removing means is
3. The liquid toner fixing device according to claim 1, further comprising a substrate temperature increasing device for increasing the temperature of the material to which the liquid toner is transferred. The substrate temperature raising apparatus is
4. The liquid toner fixing device according to claim 3, further comprising: a flash light irradiation device that irradiates the printed material to which the liquid toner has been transferred with flash light to raise the temperature of the printed material. The substrate temperature raising apparatus is
The printed matter preheating means is provided on the upstream side in the sheet conveying direction from the flash irradiation device, and preheats the printed matter to which the liquid toner has been transferred. Item 5. The liquid toner fixing device according to Item 4. The carrier removing means is
6. A blower disposed between the toner fixing unit and the substrate temperature-elevating device for accelerating the evaporation of the carrier on the substrate. The liquid toner fixing device according to claim 1. A carrying belt with an opening having an opening in the placement portion on which the substrate is placed;
The said to-be-printed material is comprised so that the said carrier removal means may be conveyed in the state mounted on the said conveyance belt with an opening, The any one of Claims 1-6 characterized by the above-mentioned. Liquid toner fixing device. It has a chain gripper that conveys it while gripping the end of the substrate,
7. The liquid toner fixing device according to claim 1, wherein the substrate is transported by the carrier removing unit while being held by the chain gripper. 8. . The carrier removing means is
8. The apparatus according to claim 7, further comprising a suction unit that is disposed so as to face the substrate temperature raising device with a conveyance path of the substrate interposed therebetween and sucks air from the substrate side. Or the liquid toner fixing device according to 8. A liquid toner fixing device according to any one of claims 1 to 9,
A developing unit that performs development by transferring the charged liquid toner onto a photoreceptor on which an electrostatic latent image is formed;
A liquid developing electronic printer comprising: an intermediate transfer member disposed between the photosensitive member and the substrate to transfer the liquid toner on the photosensitive member to the substrate. . The developed toner image is transferred to the substrate by transferring the liquid toner in which the charged particulate toner is dispersed in the liquid carrier onto the photoconductor, and the liquid toner transferred to the substrate is transferred. A liquid toner fixing method for fixing the toner to the printing material,
A toner fixing step for fixing the toner in the liquid toner transferred to the substrate to the substrate;
A liquid toner fixing method, comprising: a carrier removing step of evaporating and removing the carrier of the liquid toner transferred to the substrate to be executed prior to the toner fixing step. In the toner fixing step,
The liquid toner fixing method according to claim 11, wherein the toner is fixed to the printing material by heating and pressurizing the printing material to which the toner has been transferred. The carrier removal step includes
13. The liquid toner fixing method according to claim 11, further comprising a substrate temperature increasing step for increasing the temperature of the material to which the liquid toner is transferred. The substrate temperature raising step is
14. The liquid toner fixing method according to claim 13, further comprising a flash irradiation step of irradiating the substrate to which the liquid toner is transferred with flash to raise the temperature of the substrate. The substrate temperature raising step is
15. The liquid toner fixing method according to claim 14, further comprising a pre-printing object heating step for preheating the printing medium to which the liquid toner has been transferred prior to the flash irradiation step. The carrier removal step includes
16. A blower step for blowing air on the print substrate between the execution of the temperature increase step of the print substrate and the execution of the toner fixing step. The liquid toner fixing method according to any one of the above. In the carrier removal step,
The liquid toner fixing according to any one of claims 11 to 16, wherein the printing material is conveyed in a state of being placed on a conveying belt with an opening having an opening in a placing portion. Method. In the carrier removal step,
17. The liquid toner fixing method according to claim 11, wherein the printing material is conveyed in a state of being held by a chain gripper that holds an end portion of the printing material. The carrier removal step includes
19. The liquid toner fixing according to claim 17, further comprising a suction step that is performed simultaneously with the substrate temperature raising step and sucks air from the opposite side across the conveyance path of the substrate. Method.

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