JP2003107924A - Image forming apparatus and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-quality image at high speed by temporarily holding a visible image formed on a latent image bearing member on an intermediate transfer medium, and always stably removing toner remaining on the surface of the intermediate transfer medium in image forming for transferring the visible image to the image carrier. SOLUTION: An image forming apparatus has the latent image bearing member 1, electrifying devices 21 to 24, laser exposure means 31 to 34, developing units 41 to 44, an intermediate transfer roll 8, and an intermediate cleaning mechanism 11. The intermediate cleaning mechanism 11 is provided with a cleaning roller 111 which is pressed to an intermediate transfer roll 8 to transfer the toner remaining on the surface of the intermediate transfer roll 8, and a blade 112 which scrapes soiling by toner on the surface of the cleaning roller 111. The cleaning roller 111 has a hollow metallic roller 111A in which an infrared ray heater 111D is built as a core material. A silicone rubber layer having hardness of 40 and thickness of 2.0 mm is formed on the core material as an elastic body layer 111B, and a stainless steel layer having thickness of 30 micrometers is formed at the outer side as a metallic layer 111C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an offset type image forming apparatus and image forming apparatus using an intermediate transfer member using a liquid developer used in electrophotographic copying machines, printers, facsimiles, various printing apparatuses, proofers and the like. The present invention relates to a method, and more particularly, to a technique for removing an adhering material such as a developer and paper powder remaining on the surface of an offset type intermediate transfer medium.

[0002]

2. Description of the Related Art Conventionally, a wet image forming apparatus using a liquid developer has been developed as an image forming apparatus such as an electrophotographic recording apparatus and an electrostatic recording apparatus. This wet image forming apparatus is
An electrostatic latent image is formed on the latent image holding member, a visible image is formed by supplying a developer to the electrostatic latent image, and the visible image is formed on the intermediate transfer medium provided in contact with the latent image holding member. The visual image is taken from the latent image carrier, and this visible image is transferred to a sheet.

An electrophotographic printer using such an intermediate transfer medium is equipped with a cleaning mechanism for removing toner, paper dust and the like adhering to the intermediate transfer medium in order to improve image quality.

An example of this cleaning mechanism is disclosed in Japanese Patent Laid-Open No. 4-45829. As shown in FIGS. 9A and 9B, the image forming apparatus described in this publication forms an electrostatic latent image on a photosensitive drum 1 by a charging device 102 and an exposure device 103, and electrostatically forms an electrostatic latent image. A liquid developer is supplied to the latent image by a dry developing device 104 to form a visible image, and the visible image is transferred from the photosensitive drum 1 to an intermediate transfer member 105 provided in contact with the photosensitive drum 1. The visible image is transferred onto an image carrier (paper), and a cleaning roller 106 is provided as a cleaning unit for the intermediate transfer member 105.

The intermediate transfer member 105 includes a heat source 105A for heating the intermediate transfer member 105, a metal core 105B which is a hollow inner roller member, an elastic layer 105C formed on the surface of the metal core 105B, and the elastic layer 105C. The transfer layer 105D is formed on the surface.

On the other hand, the cleaning roller 106 is driven to rotate with respect to the intermediate transfer member 105, and the heat resistant rubber layer 10 formed on the outer side of the metal core roller 106A.
6B and a nickel electroformed layer 106C of 50 μm to 200 μm formed on the outside thereof.

[0007]

However, in the above-described cleaning mechanism, since the cleaning roller 106 itself is not heated, the temperature of the surface of the intermediate transfer body 105 is not increased when the cleaning roller 106 is pressed against the intermediate transfer body 105. There is a drawback that the toner surface in the molten state is partially solidified and cannot be efficiently transferred from the surface of the intermediate transfer member 105 to the nickel electroformed layer 106C, and a cleaning residue remains.

Therefore, the transfer efficiency of the remaining toner from the intermediate transfer member 105 to the cleaning roller 106 is increased,
In order to perform stable cleaning of the remaining toner, it is necessary to raise the temperature of the cleaning roller 106 in advance to a temperature in a region that does not affect the molten state of the toner.

However, in the above-described cleaning mechanism, the cleaning roller 106 has the metal core 105 inside.
Since the structure having B is used, the heat capacity is large, and the temperature rise of the roller is performed only by heat conduction from the heated intermediate transfer body 105. Warm-up operation in which contact rotation is performed is required.

Therefore, according to the present invention, an electrostatic latent image is formed on a latent image carrier, and a visible image is formed by supplying a liquid developer to the electrostatic latent image. Provided in contact with the image carrier, a visible image is transferred from the latent image carrier and temporarily retained, and the visible image is transferred to the image carrier. An object of the present invention is to provide an image forming apparatus and method that can stably remove and obtain a high-quality image at high speed.

[0011]

In order to achieve the above object, an image forming apparatus and method according to the present invention form an electrostatic latent image on a latent image carrier, and a liquid developer is formed on the electrostatic latent image. To form a visible image, remove the excess developer of the visible image, and provide an intermediate transfer means in contact with the latent image carrier to transfer the visible image from the latent image carrier. In the image formation in which the visible image is temporarily held and transferred to the image carrier, the orbiting means whose contact surface with the intermediate transfer means is made of metal is heated, and the visible image of the intermediate transfer means is heated. Is brought into contact with the visible image holding surface, and the removing means is brought into contact with the intermediate transfer means.

As the heating means of the circulating means, a lamp heater such as an infrared lamp or a halogen lamp, a surface heater such as a ceramic heater, a ribbon heater coated with an alloy heater such as a nichrome wire or a kanthal wire, or the like is used. You can

According to the present invention, in a so-called wet image forming apparatus, the metal surface of the circulating means is brought into contact with the visible image holding surface of the intermediate transfer means, so that the toner or the paper adhered to the visible image holding surface or the paper. Powder or the like can be attached to the metal surface and removed from the visible image holding surface. Since the metal surface is heated and raised in temperature, it is possible to prevent the toner on the visible image holding surface from solidifying, and it is possible to easily remove the toner from the visible image holding surface. .

The operation and effect of the present invention will be described below with reference to experimental examples. Table 1 shows the holding temperature of the circulation means and the transfer efficiency of the remaining toner.

[0015]

[Table 1] In the experiment, the holding temperature of the intermediate transfer medium was set to 90 ° C., a toner image of a certain area was formed on the intermediate transfer medium, and the orbiting means was pressed against it, and the transfer efficiency was obtained by the area ratio of the toner transferred to the cleaning roller surface. It was When the holding temperature of the circulating means is lower than the holding temperature of the intermediate transfer medium by 30 ° C. or more, the surface of the toner remaining in contact with the metal layer is solidified to cause transfer failure and good cleaning cannot be performed.

If the temperature is too high, the silicone rubber used as the elastic layer deteriorates quickly and the durability decreases.
It is not practical because it also increases power consumption. Therefore, the cleaning roller is capable of cleaning the remaining toner in a highly efficient and stable manner within a range of -30 ° C to + 20 ° C with respect to the holding temperature of the intermediate transfer roller.

In the above invention, the orbiting means may be a roller member which makes rolling contact with the visible image holding surface. In this case, since the roller member is in rotational contact with the visible image holding surface, it is possible to reduce friction between the rotating holding surface and the metal surface.

Further, in the above invention, the circulating means may be a belt member which is wound around a plurality of rotating bodies and is in rolling contact with the visible image holding surface. In this case, the area of the metal surface in contact with the visible image holding surface can be increased, and the wear of the metal surface can be reduced.

Further, it is preferable that the metal surface of the circulating means is formed on a surface of an elastic layer made of an elastic material. According to this, the elastic deformation of the elastic layer can improve the adhesion between the metal surface and the visible image holding surface, and the elastic deformation of the elastic layer reduces the contact area between the visible image holding surface and the metal surface. Can be increased.

Further, when the circulating means has a structure in which the elastic body layer and the metal layer are laminated in this way, the heat capacity can be reduced, and therefore the built-in heater is used until the desired temperature range is reached. The temperature rising time can be shortened, and a constant temperature region can be always maintained with low power consumption. Therefore, the temperature of the surface of the intermediate transfer medium does not drop due to the contact with the intermediate transfer medium, and it is possible to constantly and efficiently transfer the residual toner from the surface of the intermediate transfer medium to the metal layer on the surface of the circulation means. Becomes

The elastic layer has a hardness of 20 to 80 degrees (JIS-
A: JIS hardness Shore A type), the thickness is 0.5 mm to 5.0 mm, and the thickness of the metal layer is preferably 10 μm to 300 μm. Table 2 shows the transfer efficiency when silicone rubber having a thickness of 2 mm is used as the elastic body and the hardness of the rubber is changed.

[0022]

[Table 2] As shown in Table 2, when the hardness of the elastic layer is too small,
A portion deformed by being pressed against the intermediate transfer medium is not recovered, and good cleaning cannot be performed. Further, if the hardness is too high, the area of pressure contact with the intermediate transfer medium becomes small and the transfer efficiency decreases. Therefore, when the hardness of the elastic body is in the range of 20 to 80, and more preferably in the range of 30 to 60, the residual toner can be cleaned constantly with high efficiency.

Table 3 shows the transfer efficiency when silicone rubber having a hardness of 40 is used as the elastic body and the thickness of the elastic body layer is changed.

[0024]

[Table 3] As shown in Table 3, when the elastic layer was thin, the contact area with the intermediate transfer medium was small and the transfer efficiency was low. Also, if the elastic layer is too thick, heat conduction will deteriorate,
Temperature unevenness occurred and the transfer efficiency decreased. Therefore, when the thickness of the elastic layer is 0.5 mm to 7.0 mm, more preferably 1.0 mm to 5.0 mm, the residual toner can be cleaned constantly with high efficiency.

In Table 4, the elastic layer has a hardness of 40 and a thickness of 2.0 mm.
2 shows the transfer efficiency when the thickness of the metal layer is changed by using the silicone rubber of.

[0026]

[Table 4] When the metal layer is thin, it is likely to be deformed due to the presence of slight irregularities or foreign matter, resulting in poor contact with the intermediate transfer medium and a decrease in transfer efficiency. Further, when the metal layer was too thick, the area of pressure contact with the intermediate transfer medium was small and the transfer efficiency was reduced. Therefore, when the thickness of the metal layer is 10 μm to 300 μm, more preferably 20 μm to 100 μm, the residual toner can be stably cleaned with high efficiency.

Therefore, as in the present invention, the elastic layer of the orbiting means has a hardness (JIS-A) of 20 to 80 and a thickness of 0.5 mm to 7.0 mm, and the metal layer has a thickness of 10 μm to 300 μm.
The residual toner on the surface of the intermediate transfer unit can always be stably removed with high efficiency, and a high-quality image can be obtained at high speed with low power consumption.

Further, it is preferable that the cleaning means has a removing means which is provided so as to be capable of contacting the metal portion of the circulating portion. According to this, it is possible to remove the adhering matter that has adhered to the surface of the orbiting portion, prevent the adhering material that has adhered to the surface of the orbiting portion from adhering to the visible image holding surface again, and prevent deterioration of image quality. it can.

That is, the toner stains transferred to the circulating means and adhered to the surface of the metal layer are removed by bringing the scraping means and the web roller, which will be described later, into contact with each other. On this occasion,
Since the orbiting means is heated, the toner stain is in a molten state and can be easily removed from the metal layer.

Therefore, with the image forming apparatus and the image forming method including the cleaning means of the present invention, the residual toner on the surface of the intermediate transfer medium can be removed stably with high efficiency, and good image transfer can be always performed. High quality high speed printing can be achieved.

As the removing means, it is possible to use a plate-like scraping means which is slidably provided on the metal surface of the circulating means. This scraping means can be formed of a stainless plate or a heat resistant resin. According to this, the deposit on the surface of the metal surface can be removed with a simple configuration of scraping off the metal surface.

Further, the removing means may be a web roller which is in rolling contact with the metal surface of the circulating means. According to this, by wiping the metal surface with the web roller, it is possible to remove the metal surface-like deposit.

The material of this web is woven / nonwoven fabric made of aramid fiber / polyester fiber, fine porous polytetrafluoroethylene resin sheet, paper, cloth, non-woven fabric, felt of aromatic polyamide, etc. Can be used.

Furthermore, the removing means may be an adhesive roller which is in rolling contact with the metal surface of the orbiting means and is made of a material having an adhesive property on the surface.
A viscous pressure-sensitive adhesive may be applied to the surface of the pressure-sensitive adhesive roller. The pressure-sensitive adhesive may be an aqueous acrylic emulsion (water-based pressure-sensitive adhesive), a rubber-based pressure-sensitive adhesive such as polyterpene-based resin, polyolefin-based resin, or polystyrene-based resin. Aromatic petroleum resins, alkylphenol resins, rosins, rosin derivatives, silicone resin adhesives and the like can be used.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] (Basic Structure of Image Forming Apparatus) An image forming apparatus according to an embodiment of the present invention will be described in detail below. FIG. 1 shows the entire wet-type image forming apparatus according to this embodiment.

As shown in FIG. 1, the image forming apparatus according to the present embodiment has a latent image carrier 1 and first to fourth chargers 21.
To 24, and first to fourth laser exposure means 31 to 34,
First to fourth developing devices 41 to 44, a liquid removing member 5, and
Drying mechanism 6, solvent recovery device 7, and intermediate transfer roller 8
And a backup roller 9 and an intermediate body cleaning mechanism 11.

The liquid developer according to this embodiment is a liquid toner, for example, a material in which colored resin particles are dispersed in a well-known petroleum-based insulating solvent (trade name: ISOPAR L, manufactured by Exxon). Can be used. The resin particles are
It is preferable to add a coloring pigment and a charge control agent to a thermoplastic resin having a glass transition point of 45 ° C. to have an average particle size of about 0.6 μm.

The latent image holder 1 holds a latent image and a visible image. In this embodiment, a photosensitive drum having a photosensitive layer of organic type or amorphous silicon type provided on a conductive substrate. To use.

The first to fourth chargers 21 to 24 and the laser exposure means 31 to 34 constitute a latent image forming means for forming an electrostatic latent image on the latent image holder 1. 1st to 4th
The charging devices 21 to 24 uniformly charge the image forming surface of the surface of the latent image holding member 1. For example, a well-known corona charging device or scorotron charging device can be used.

The laser exposure means 31 to 34 are for exposing the charged latent image carrier 1 with an image-modulated laser beam to form an electrostatic latent image.

The first to fourth developing devices 41 to 44 are developing means for forming a visible image by supplying a liquid developer to the electrostatic latent image on the latent image holding member 1. Then
Each of the developing devices 41 to 44 has a first roller for applying the liquid toner and a second roller for removing the excess liquid toner.

In this embodiment, the first charger 2
1, first laser exposure means 31, and first developing device 4
1 to form a first visible image, the second charger 22, the second laser exposure means 32, and the second developing device 42 to form a second visible image, and the third charger. 23, the third laser exposure means 33, and the third developing device 43
And a fourth visible image is formed by the fourth charger 24, the fourth laser exposure means 34, and the fourth developing device 44. These first to fourth visible images are formed by liquid toners of different colors. That is, after the first development and the second development, two color toner images are formed on the latent image carrier 1, and the third and fourth developments are subsequently performed, so that the latent image carrier 1 is formed. A full-color toner image is formed on.

In the present embodiment, the liquid removing member 5 is a metal roller arranged at a distance of 20 μm from the surface of the latent image holding member 1 and removes a part of the excess developer on the surface of the latent image holding member 1. To remove.

The drying mechanism 6, which is a so-called air knife, is disposed in the vicinity of the latent image holder 1 and injects dry air of a predetermined wind speed onto the surface of the latent image holder 1 to force the excess developing solution. It is evaporated to adjust the dry state. The drying mechanism 6 in this embodiment has a wind speed of 0.
Blow dry air at 4mm ³ / min. The solvent recovery device 7 is
The surplus solvent is recovered.

The intermediate transfer roller 8 is an intermediate transfer means which is provided so as to be in contact with the latent image carrier 1 and which transfers a visible image from the latent image carrier 1 and temporarily holds it. In the present embodiment,
It is in the form of a roller that makes rolling contact with the surface of the latent image carrier 1. The intermediate transfer roller 8 has a heater 11 inside.
1D and its temperature is kept at 90 ° C.
Further, the intermediate transfer roller 8 has a load of 50 kg, and the latent image carrier 1
Is in pressure contact with.

As the heater 111D, a lamp heater such as an infrared lamp or a halogen lamp, a surface heater such as a ceramic heater, a nichrome wire,
A ribbon heater coated with an alloy heater such as Kanthal wire can be used.

The backup roller 9 is a pressure roller that comes into rolling contact with the intermediate transfer roller 8 with a predetermined pressure. The backup roller 9 cooperates with the intermediate transfer roller 8 to grip the sheet 10 and copy it onto the intermediate transfer roller 8. The formed visible image is transferred to the paper 10 and is rotated to feed the paper 10 in the paper feeding direction. In this embodiment, the backup roller 9 has a heater inside, and the temperature thereof is maintained at 90 ° C. and is in pressure contact with the intermediate transfer roller 8 with a load of 50 kg.

The intermediate body cleaning mechanism 11 is a cleaning means for removing the adhered matter adhering to the surface of the intermediate transfer roller 8. In this embodiment, as shown in FIG. A cleaning roller 111 that transfers the remaining toner on the surface of the roller 8 and a blade 112 that scrapes off toner stains on the surface of the cleaning roller 111 are provided.

The cleaning roller 111 is a revolving means which is provided so as to be in contact with the visible image holding surface of the intermediate transfer roller 8 on which the visible image is held, and whose contact surface with the intermediate transfer roller 8 is made of metal. In this embodiment, the roller member is in rolling contact with the visible image holding surface of the intermediate transfer roller 8.

The cleaning roller 111 is a hollow metal roller 111 containing an infrared heater 111D.
A is used as a core material, and an elastic layer 111B is formed on it as a hardness of 4
A silicone rubber layer having a thickness of 2.0 mm and a thickness of 2.0 mm is formed, and a stainless layer having a thickness of 30 μm is formed as a metal layer 111C on the outer side thereof. The metal layer may be a nickel layer instead of the stainless layer.

The cleaning roller 111 is
While the surface temperature of the stainless steel layer 111C was kept at 90 ° C., it was pressed against the intermediate transfer roller 8 with a load of 2 kg and was driven by the rotation of the intermediate transfer roller 8 to adhere to the surface of the intermediate transfer roller 8 (toner, Paper dust or the like) is transferred to the stainless layer 111C on the surface of the cleaning roller 111. As a result, the transfer efficiency can be almost 100%.

It is preferable to use elastic rubber as the elastic layer 111B, for example, nitrile butadiene rubber, butyl rubber, ethylene propylene rubber,
Chlorinated polyethylene rubber and acrylic rubber can be used.

The blade 112 is the cleaning roller 1
11 is a plate-shaped scraping means provided slidably in contact with the metal layer 111C, and in the present embodiment, it is brought into contact with the stainless steel layer 111C on the surface in the reverse direction with respect to the rotation of the cleaning roller 111 and is made of stainless steel. The toner dirt attached to the surface of the layer 111C is scraped off by the blade 112 and accumulated on the tray 1113. The removed material accumulated in the tray 113 is removed by periodically removing the tray 113.

The detailed structure of the blade 112 is shown in FIG.
Shown in. The blade 112 includes a holder 112A that holds the contact plate 112B and the scraping blade 112C, a backing plate 112B that supports the scraping blade 112C, and a stainless steel scraping blade 112C that removes deposits on the surface of the cleaning roller 111. The thickness of the scraping blade 112C main body is 0.5 mm, the tip portion is sharp at an acute angle, for example, an angle of 30 degrees, and the thickness of the tip portion is 0.1 mm or less. Further, the tip of the scraping blade 112C is in contact with the tangential direction of the cleaning roller 111 at an acute angle, for example, 20 degrees. The scraping blade 112C is brought into contact with the cleaning roller 111 in a reverse direction with respect to the rotation direction of the cleaning roller 111 and at a steep angle.
It is possible to efficiently scrape off toner stains on the surface.

(Image Forming Method) First, the image forming surface of the latent image holding member 1 is uniformly charged by the charger 21, and exposed by the laser exposing means 31 to form a first electrostatic latent image. Next, liquid toner is supplied to the first electrostatic latent image by the developing device 41 to visualize the electrostatic latent image.

Subsequently, a second electrostatic latent image is formed by the second charger 22 and the second laser exposure means 32, and a second liquid developer having a color different from that of the first visible image is applied to the second developing device. This is developed by 42. After that, similarly, the third and fourth developments are performed. When printing in a single color, only the first development is performed and the second to fourth developments are omitted.

Then, the excess developer adhering to the visible image is removed through a drying process including the liquid removing member 5 and the drying mechanism 6. That is, the visible image on the latent image carrier 1 that has undergone the drying process is transferred to the surface of the intermediate transfer roller 8 by pressure contact with the intermediate transfer roller 8, and the transferred visible image is further transferred to the backup roller 9. Is transferred to the sheet 10 by the cooperation of.

After this transfer step, the surface of the intermediate transfer roller 8 is cleaned by the intermediate body cleaning mechanism 11. That is, the adhered matter attached to the surface of the intermediate transfer roller 8 is the metal layer 111 on the surface of the cleaning roller 111.
The deposit transferred to C and transferred to the metal layer 111C is scraped off by the blade 112 and accumulated on the tray 113.

(Effects of Image Forming Apparatus and Method) With the cleaning means having the above construction, the toner residue on the surface of the intermediate transfer roller 8 can be almost completely removed by the cleaning roller 111 while the latent image carrier 1 makes one rotation. At the same time, toner stains on the surface of the cleaning roller 111 are also removed by the blade 112 or the web cleaner 13, so that a transfer failure occurs even when a toner image newly formed on the latent image holding member 1 by the next rotation is transferred. It is possible to obtain a high quality image at high speed.

(Modification 1) The present invention is not limited to the above-described embodiment, but the following modifications can be added.

For example, as shown in FIG. 4, a web cleaner 13 may be provided in place of the above-mentioned blade 112 as a cleaning means for removing toner stains on the surface of the cleaning roller 111. The structure of the web cleaner 13 is a web roller 1 in which a web 13A, which is a belt member formed of a non-woven fabric of polyester resin fibers, is wound.
3B, a tension roller 13C that abuts against the surface of the cleaning roller 111 while applying an appropriate tension to the web 13A, and a web roller 13 that winds the used web.
D, and the web rollers 13B and 13D can be replaced appropriately. The web 13A pulled out from the web roller 13B wipes off the toner stains on the surface of the cleaning roller 111, and is wound around the web roller 13D, whereby the toner stains on the surface of the cleaning roller 111 can be efficiently removed.

In this modification, a nonwoven fabric of polyester resin is used as the web 13A, but a similar effect can be obtained with a normal woven fabric. Further, as the web 13A, a web using a resin having higher heat resistance depending on the holding temperature of the intermediate transfer roller 8, for example, a fiber such as a polyimide resin, a polyamide resin, or an aramid resin, or a web made of a fine metal wire is used. By using it, highly reliable cleaning can be realized even when the holding temperature of the intermediate transfer roller 8 is high. Furthermore, this web 1
As the material of 3A, for example, woven / nonwoven fabric made of aramid fiber / polyester fiber, microporous polytetrafluoroethylene resin sheet, paper, cloth, nonwoven fabric, felt of aromatic polyamide can be used.

In addition, as a cleaning means for removing toner stains on the surface of the cleaning roller 111, as shown in FIG. 6, a web crawler 13E having a hollow metal core 13F and a woven or non-woven web 13G, such as felt, wound around the hollow metal core 13F. The same effect can be obtained by directly contacting the cleaning roller 111 with the surface of the cleaning roller 111 to remove toner stains. Further, the same effect can be obtained by directly contacting the surface of the cleaning roller with the brush roller to remove toner stains.

Further, as the web, an adhesive roller having an adhesive layer formed on the surface may be used (not shown). As an adhesive material forming this adhesive layer, for example, an aqueous acrylic emulsion (aqueous adhesive) or a rubber-based adhesive material can be used. As the rubber-based pressure-sensitive adhesive, for example, polyterpene-based resin, polyolefin-based resin, polystyrene-based resin, aromatic petroleum-based resin, alkylphenol resin, rosin, rosin derivative, or silicone resin-based resin can be used.

(Modification 2) Further, in the above-mentioned embodiment, the silicone rubber is used as the elastic layer 111B, but by selecting the rubber in the temperature range which can be used appropriately according to the transfer temperature of the intermediate transfer roller 8. The same effect can be obtained with urethane rubber, butadiene-styrene rubber, chloroprene rubber and fluorine rubber. Also, this elastic layer 1
As 11B, a porous silicone resin, urethane resin, fluorine resin, or the like that can obtain a desired hardness may be used. Further, as the elastic body layer 111B, a material obtained by kneading rubber with a powder having a high thermal conductivity such as AlN or SiC can be used to improve the thermal conductivity of the elastic body layer and reduce power consumption. It is possible.

(Modification 3) In the above-described embodiment, stainless is used as the metal layer 111C, but other metals such as nickel, chromium, copper, aluminum, molybdenum, or a laminated body or an alloy thereof may be used. The effect is obtained. At this time, as a method for forming a seamless metal layer, a hollow pipe is prepared in advance by electroless or electrolytic plating, and a hollow metal roller having a rubber layer formed thereon is covered, or a hollow metal layer having a rubber layer formed directly thereon is formed. A method of applying a plating catalyst such as Pd to the rubber layer of the roller and forming the metal layer by electroless plating and electrolytic plating or a step of only electroless plating can be adopted.

As the metal layer 111C, a metal foil of stainless steel or the like is used, which is wound around the outermost surface of a hollow metal roller having a rubber layer formed thereon, and the bonded portion is covered with a heat-resistant resin to eliminate steps. You may form by. In this case, the resin coating portion preferably has a width of 0.5 mm or less.

(Modification 4) In the above-described embodiment, the blade 112 is made of a thin stainless steel plate whose tip is processed into an acute angle. However, a hard machinable resin such as POM resin or PEEK resin may be used instead. A scraping blade may be used.
In this case, for example, as shown in FIG.
The tip of C is processed into an obtuse angle to obtain mechanical strength,
By making one end of the corner abut on the surface of the cleaning roller 111, it is possible to sufficiently scrape off the toner stains.

(Modification 5) In the first embodiment described above,
The blade 112 is used as a means for scraping off the toner stains on the surface of the cleaning roller 111, as shown in FIG.
As shown in FIG.
A separating mechanism 112D that separates and attaches to and from 11 may be provided, and a web roller 112E that cleans the separated blade 112 may be provided.

The separating mechanism 112D rotates the scraping blade 112C, the abutting plate 112B, and the holder 112A that grips them to rotate the scraping blade 112C.
Is attached to and detached from the cleaning roller 111, and is periodically driven based on a control signal from a control unit (not shown).

The web roller 112E includes a separating mechanism 112.
The roller member is arranged at a position where it can contact the scraping blade 112C separated from the cleaning roller 111 by driving D, and the surface thereof is formed of a nonwoven fabric of polyester fiber or the like. This web roller 112E
When the scraping blade 112C is brought into contact with the scraping blade, the scraping blade rotates in the direction shown in the drawing and wipes off the deposits adhering to the scraping blade 112C.

The separation mechanism 112 according to the present modification as described above.
According to D and the web roller 112E, the blade 112
The toner residue on the blade 112 can be removed by wiping off the adherent such as the toner residue attached to the blade.

Therefore, for example, in the case where the adhered matter such as toner slag adhered to the blade 112 has a high adhesiveness and remains adhered to the blade 112 after scraping, and the adhered matter itself does not fall onto the tray 113. Then, the adhered matter adhered to the blade 112 is again removed by the cleaning roller 11
It is possible to avoid the possibility that the cleaning roller 111 adheres to the first side and contaminates the cleaning roller 111. As a result, the surface of the cleaning roller 111 can always be kept clean, and cleaning can always be performed with high efficiency when the toner residue is transferred from the intermediate transfer roller 8.

[Second Embodiment] Next, a second embodiment of the image forming apparatus of the present invention will be described. FIG. 7 is a schematic configuration diagram showing the configuration of the cleaning unit according to the present embodiment. In this embodiment, instead of the cleaning means 11 in the first embodiment described above, the cleaning means 1
4 is provided.

That is, the image forming apparatus according to the present embodiment forms a toner image which is a visible image on the latent image holding member 1 and holds the toner image at 90 ° C. as in the first embodiment described above. Then, it is transferred to the surface of the intermediate transfer roller 8 by pressure contact of the intermediate transfer roller 8 with a total load of 50 kg, and further transferred to the sheet 10 via the backup roller 9 which is kept at 90 ° C. and the total load of 50 kg. After the transfer process, the intermediate transfer roller 8 cleans the surface by the intermediate body cleaning mechanism 14.

The intermediate body cleaning mechanism 14 is shown in FIG.
As shown in (a), a cleaning belt 143 that is in pressure contact with the intermediate transfer roller 8 to transfer the residual toner on the surface of the intermediate transfer roller 8, a hollow metal roller 141 that is a support of the cleaning belt 143, and a hollow metal roller. 141
A heater 142 built in the printer, a blade 144 for removing toner stains transferred onto the surface of the cleaning belt 143, and a tray 145 are provided.

The hollow metal roller 141 applies an appropriate tension to the cleaning belt 143, and at the same time, holds the portion of the cleaning belt 143 which is in contact with the surface of the intermediate transfer roller 8 by the built-in heater 142 in an appropriate temperature range.

The cleaning belt 143 is shown in FIG.
As shown in Fig. 2, a metal supporting belt 143A made of a stainless plate having a thickness of 2 mm and an elastic layer 143B made of silicone rubber having a hardness of 50 and a thickness of 3.0 mm are formed, and the metal layer 1 is formed on the outer side thereof.
As 43C, a nickel plating layer having a thickness of 45 μm is formed.

In the cleaning belt 143, the infrared heater 142 is set so that the temperature of the surface of the stainless steel layer 143C is 90 ° C., and the intermediate transfer roller 8 is pressed with a load of 2 kg. The remaining toner on the surface 8 is transferred to the surface of the cleaning belt 143. Toner stains adhering to the surface of the stainless steel layer 143C are scraped off by the blade 144 and accumulated on the tray 145.

Although the cleaning belt 143 is driven in this embodiment, it may be driven in the opposite direction to the rotation direction of the intermediate transfer roller with an appropriate driving force.

Although the roller-shaped medium is used as the intermediate transfer medium according to the present embodiment, a belt-shaped medium may be used. For example, as shown in FIG.
Is the intermediate transfer belt 203 and the belt drive roller 20.
1, 202. Intermediate transfer belt 20
3 is made of a material similar to that of the intermediate transfer roller 8 of the embodiment, and may be made of only an elastic material, or has a structure of two or more layers by using another elastic material having high hardness or metal as a support. You can use any Intermediate transfer belt 203
Is in contact with the outside of the two belt drive rollers 201, 202 and is supported and driven by these rollers. The belt drive rollers 201 and 202 are made of metal, for example, one of which presses the intermediate transfer belt 203 against the photosensitive drum 1 and the other of which presses the intermediate transfer belt 203 against the backup roller 9 via the recording medium 10.
The intermediate body cleaning mechanism 204 includes the belt driving roller 2
It is arranged on the No. 02 side and is pressed by the intermediate transfer belt 203 to clean the adhered matter on the belt surface.

[0082]

As described above, according to the image forming apparatus and the image forming method of the present invention, the electrostatic latent image is formed on the latent image holding member and the liquid developer is supplied to the electrostatic latent image. To form a visible image, the intermediate transfer means is provided in contact with the latent image carrier, the visible image is transferred from the latent image carrier and temporarily held, and the visible image is carried on the image carrier. In the image formation in which the image is transferred to, the residual toner on the surface of the intermediate transfer medium can always be stably removed, and a high-quality image can be obtained at high speed.

[Brief description of drawings]

FIG. 1 is an overall sectional view showing a schematic configuration of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an intermediate body cleaning mechanism according to the first embodiment.

FIG. 3A is a sectional view showing a blade mechanism according to the first embodiment, and FIG. 3B is a sectional view showing a modified example of the blade mechanism.

FIG. 4 is a cross-sectional view showing an intermediate body cleaning mechanism according to Modification 1 of the first embodiment.

FIG. 5 is a sectional view showing a blade mechanism according to a second modification of the first embodiment.

FIG. 6 is a cross-sectional view showing an intermediate body cleaning mechanism according to Modification 3 of the first embodiment.

7A is a sectional view showing an intermediate body cleaning mechanism in an image forming apparatus according to a second embodiment of the present invention, and FIG. 7B is an enlarged sectional view showing a cleaning belt.

FIG. 8 is a cross-sectional view showing an intermediate transfer medium according to a modified example of the second embodiment.

FIG. 9 is an explanatory diagram showing a schematic configuration of a conventional image forming apparatus.

[Explanation of symbols]

1 ... Latent image holder 2 ... Charger 3 ... Laser exposure means 4 ... Developer 5 ... Liquid removing member 6 ... Drying mechanism 7 ... Solvent recovery device 8 ... Intermediate transfer roller 9 ... Backup roller 10 ... Paper 11, 14 ... Intermediate cleaning mechanism 12 ... Photoconductor cleaner 13 Web cleaner 111 ... Cleaning roller 111A ... Hollow metal roller 111B ... Elastic layer 111C ... Metal layer 111D ... Heater 112 ... Blade 112A ... Holder 112B ... Reliable plate 112C ... Scraping blade 113 ... tray 13A ... Web 13B ... Web roller 13C ... tension roller 13D ... Web roller 13E ... Web roller 13F ... Hollow metal core 13G ... web 141 ... Hollow metal roller 142 ... Heater 143 ... Cleaning belt 144 ... blade 145 ... tray 143A ... Metal support belt 143B ... Elastic layer 143C ... Metal layer

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H074 AA03 BB43 BB46 BB73 EE07                 2H200 FA19 GA23 GA43 GA47 GB22                       GB40 JA07 JA08 JA29 JB06                       JB10 JC02 JC03 JC13 JC17                       JC19 LA23 LA24 LA31 LB02                       LB08 LB09 LB13 LB14 LB15                       LB19 LB33 LB35 LB37 LB39                       MA01 MA03 MA04 MA05 MA13                       MA20 MC01 MC02 PA15

Claims (10)

[Claims] 1. A latent image forming means for forming an electrostatic latent image on a latent image carrier, a developing means for forming a visible image by supplying a liquid developer to the electrostatic latent image, and the latent image forming means. A drying unit that removes an excess developer of the visible image formed on the image carrier, and a contact unit that is provided so as to be in contact with the latent image carrier, and temporarily transfers the visible image from the latent image carrier. An intermediate transfer unit that holds the cleaning unit and a cleaning unit that removes adhered substances that adhere to the intermediate transfer unit are provided, and the cleaning unit can contact a visible image holding surface on which a visible image of the intermediate transfer unit is held. An image forming apparatus, comprising: a circulation unit having a contact surface with the intermediate transfer unit formed of a metal, and a heating unit configured to heat the circulation unit. 2. The image forming apparatus according to claim 1, wherein the orbiting unit is a roller member that is in rolling contact with the visible image holding surface. 3. The image forming apparatus according to claim 1, wherein the circulating means is a belt member that is wound around a plurality of rotating bodies and is in rolling contact with the visible image holding surface. 4. The image forming apparatus according to claim 1, wherein the metal surface of the circulating means is formed on a surface of an elastic layer formed of an elastic material. 5. The elastic layer has a hardness (JIS-A) of 20 to 80,
The thickness is 0.5 mm to 7.0 mm, and the thickness of the metal surface is 10 μm
The image forming apparatus according to claim 4, wherein the image forming apparatus has a thickness of 300 μm. 6. The image forming apparatus according to claim 1, wherein the cleaning unit includes a removing unit that is provided so as to be in contact with the metal portion of the circulation section. 7. The image forming apparatus according to claim 6, wherein the removing unit is a plate-shaped scraping unit that is slidably provided on the metal surface of the circulating unit. 8. The image forming apparatus according to claim 6, wherein the removing unit is a web roller that is in rolling contact with a metal surface of the circulating unit. 9. An electrostatic latent image is formed on a latent image carrier, a visible image is formed by supplying a liquid developer to the electrostatic latent image, and the visible image is formed so as to be in contact with the latent image carrier. The visible image is transferred from the latent image carrier to the intermediate transfer means,
An image forming method for transferring this visible image to an image carrier, wherein a circulating means having a contact surface with the intermediate transfer means made of metal is heated, and the visible image of the intermediate transfer means is held. The image forming method is characterized in that the removing means is brought into contact with the intermediate transfer means. 10. The image forming method according to claim 9, wherein the metal surface of the circulating means is formed on a surface of an elastic layer formed of an elastic material.