JP2006301123A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of preventing a recording medium from being stained or wrinkled owing to sticking of excessive fixing liquid to the recording medium by removing excessive fixing liquid supplied to outside the range of the size of the recording medium without disordering a formed toner image. <P>SOLUTION: A fixing liquid removing means 44 removes only the excessive fixing liquid supplied to outside the size range of the recording medium 7 detected by a size detecting means without removing fixing liquid 8 supplied to the toner image formed on the surface of a transfer fixing roller 42, so that the excessive fixing liquid supplied to outside the size range of the recording medium 7 is removed without disordering the formed toner image to prevent the recording medium 7 from being stained or wrinkled owing to the sticking of the excessive fixing liquid thereto. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  In an electrophotographic image forming apparatus often used in copying machines, printers, facsimiles, etc., a photosensitive drum having a photosensitive layer containing a photoconductive material formed on the surface is used, and a charge is applied to the surface of the photosensitive drum. After charging uniformly, an electrostatic latent image corresponding to image information is formed by various image forming processes, and the electrostatic latent image is developed with a developer supplied from a developing unit and containing toner. A toner image is formed, and this toner image is directly transferred to a recording medium such as paper or once transferred to a transfer medium such as an intermediate transfer medium, and further transferred to a recording medium. In order to fix the toner image transferred to the recording medium onto the recording medium, the recording medium is generally heated and pressurized by a fixing unit of a heat fixing system using a developing roller including a heating unit. .

  However, in an image forming apparatus including a heat fixing type fixing unit, power consumption increases by using a heating device such as a heater, and the power consumption accounts for more than half of the total power consumption in the image forming apparatus. Currently. On the other hand, in the times, energy saving has been aimed at as a measure against global warming, and the electrophotographic image forming apparatus is widely used. It is required to reduce power consumption when fixing on a recording medium. In addition, when fixing a multicolor toner image to a recording medium by a thermal fixing method, there is a problem that it takes more time than fixing a single color toner image, and the fixing time of the multicolor toner image is shortened. Is also sought.

  In view of such a demand, a wet fixing method using a fixing solution containing water and a liquid that can be dissolved or dispersed in water and has a function of softening or swelling toner is used. In this method, a toner image softened or swollen by applying a fixing solution is attached to a recording medium, and the toner image is fixed to the recording medium by applying pressure with a pressure roller or the like. The wet fixing method is generally a method in which a fixing solution is directly applied to unfixed toner transferred to a recording medium, and a toner image is fixed on the recording medium by pressing with a fixing means such as a pressure roller. The toner image formed on the photosensitive drum is transferred to a toner image carrier, a fixing liquid is applied to the toner image carried on the toner image carrier, and the toner image to which the fixing liquid is applied is applied to a pressure roller or the like. It is divided into a method of transferring and fixing to a recording medium by applying pressure by a fixing means. Each method has its advantages and is suitably used in an image forming apparatus.

  The wet fixing method is a useful method from the viewpoint of energy saving because it consumes much less power than the thermal fixing method. Further, since a large amount of heat is not required from the viewpoint of fixing time of the multicolor toner image, it can be shortened as compared with the heat fixing method. Therefore, various proposals have been made for further improvement of the wet fixing method.

  For example, in order to prevent wrinkling of a recording medium such as paper caused by an excessive application of the fixing liquid, the toner image to which the fixing liquid is applied adheres to a portion other than the toner image before being fixed to the recording medium. There has been proposed an image forming apparatus provided with means for removing excess fixing liquid (for example, see Patent Document 1). In such an image forming apparatus, examples of means for removing the fixing liquid adhering to portions other than the toner image portion include means such as a roller member, a blade member, and air removal.

  When a means such as a roller member or a blade member is used as the fixing liquid removing means as in the image forming apparatus disclosed in Patent Document 1, the fixing liquid is wiped, adsorbed, or scraped off by the removing means. Removed. However, such a removing means is not preferable because it also contacts the toner image when removing the excess fixing liquid, which may disturb the toner image before transfer and fixing. Similarly, when the fixing solution is removed by air, the fixing solution is blown off by air, and at the same time, the toner is scattered by the air, which causes the formed toner image to be disturbed. Furthermore, in order to prevent the inside of the apparatus from being contaminated by the scattered fixing solution, a member such as a scattering prevention cover is required.

  By the way, in the image forming apparatus for forming an image on a plurality of sizes of recording media, the fixing solution applying means for applying the fixing solution generally includes the image forming area of the largest recording medium in the image forming apparatus. Apply fixer to Therefore, even when a recording medium having a small size is used, the fixing liquid is applied in the same range as the above range, so that the fixing liquid is also applied outside the size range of the recording material. The excess fixing liquid applied outside the size range of the recording medium remains without being absorbed by the recording medium, and adheres to the pressure roller when fixing the toner image on the recording medium. When image formation is performed using a large-size recording medium with the fixing liquid adhering to the pressure roller, the fixing liquid adhering to the pressure roller adheres to the back surface of the large-size recording medium, and paper stains, wrinkles, etc. Produce.

  Further, when the fixer is applied to the toner image carried on the toner image carrier, the excess fixer may adhere to other members and reach the photosensitive drum. If image formation is performed while the photosensitive drum is wetted with the fixing solution, the toner changes in quality during toner image formation, and development cannot be performed on that portion, which may cause image omission.

  Although the excess fixing liquid applied outside the size range of the recording medium can be removed by the removing means disclosed in Patent Document 1, as described above, the formed toner image is disturbed. There is a fear. Further, with the removing means of Patent Document 1, even if the fixing solution is removed so that the toner image is not disturbed as much as possible, the amount of the fixing solution adhering to other than the toner image portion is reduced, and the size range of the recording medium It is difficult to completely remove the fixing solution applied to the outside. Therefore, when an image is continuously formed a plurality of times using a recording medium of a small size, the fixing liquid is accumulated outside the size range of the recording medium, and the above-described problems such as contamination and wrinkling of the recording medium are avoided. It is difficult.

JP 2004-109747 A

  The object of the present invention is to remove the excess fixing liquid applied outside the size range of the recording medium without disturbing the toner image to be formed, and to prevent the recording medium from being contaminated or wrinkled by the adhesion of the excessive fixing liquid. It is an object of the present invention to provide an image forming apparatus that can do this.

The present invention includes a photoreceptor drum that is exposed to light corresponding to image information to form an electrostatic latent image on the surface, and a toner image composed of dry toner containing a binder resin and a colorant is formed on the photoreceptor drum. The toner image forming means to be formed, the toner image formed on the photosensitive drum is transferred, the toner image carrier carrying the transferred toner image, and the toner image on the toner image carrier is softened And / or a fixing liquid applying means for applying a swelling fixing liquid, a recording medium conveying means for carrying and conveying a recording medium, and a toner image carrier. The fixing liquid is applied by the fixing liquid applying means. An image forming apparatus including fixing means for fixing a toner image to a recording medium,
Size detection means for detecting the size of the recording medium;
An image forming apparatus comprising: a fixing solution removing unit that removes excess fixing solution applied outside the size range of the recording medium detected by the size detecting unit.

In the present invention, the toner image carrier is
A recording medium carried by the recording medium conveying means;
Fixer removal means
A fixing liquid that is provided upstream of the fixing unit in the recording medium conveying direction of the recording medium conveying unit and adheres to the recording medium conveying unit before the toner image is fixed on the recording medium by the fixing unit. The excess fixer applied outside the size range is removed.

In the present invention, the toner image carrier is
A rotary drive member that carries and rotates a toner image;
Fixer removal means
Provided on the upstream side of the rotation direction of the toner image carrier with respect to the fixing unit, and before the toner image is fixed on the recording medium by the fixing unit, the surplus on the surface of the toner image carrier applied outside the size range of the recording medium. The fixing liquid is removed.

In the present invention, the toner image carrier is
A recording medium carried by the recording medium conveying means;
Fixer removal means
An excess fixing liquid that is provided downstream of the fixing unit in the recording medium conveying direction of the recording medium conveying unit and is applied outside the size range of the recording medium after the toner image is fixed on the recording medium by the fixing unit. The fixing liquid adhering to the recording medium conveying means is removed.

In the present invention, the toner image carrier is
A rotary drive member that carries and rotates a toner image;
Fixer removal means
An excess fixing liquid that is provided downstream of the fixing unit in the rotation direction of the toner image carrier and is applied to the recording medium after the toner image is fixed to the recording medium by the fixing unit. The fixing liquid adhering to the surface of the image carrier is removed.

  In addition, the present invention is characterized in that it includes another fixing solution removing unit that removes the fixing solution adhering to the fixing unit by fixing the toner image to which the fixing solution is applied.

  In the invention, it is preferable that the fixing solution removing unit includes a heating removing unit that heats and evaporates the fixing solution and removes the fixing solution.

  In the invention, it is preferable that the fixing solution removing unit includes a blade-shaped removing member that scrapes and removes the fixing solution.

  In the invention, it is preferable that the fixing solution removing unit includes a roller-shaped removing member that adsorbs and removes the fixing solution.

  According to the present invention, the fixing solution removing means includes a strip-shaped removing member that adsorbs and removes the fixing solution.

In the invention, it is preferable that the contact angle of the fixing solution is smaller than the contact angle of the fixing solution with respect to the toner image carrier.
In the present invention, the removing member is made of a liquid-absorbing material.

  In the invention, it is preferable that the fixing solution removing unit includes a suction removing unit that sucks and removes the fixing solution.

In the present invention, the fixing solution removing means is
One or more wiping means are provided corresponding to a predetermined size of the recording medium and provided to wipe off and remove excess fixing liquid applied outside the size range of the recording medium.

In the present invention, the fixing solution removing means is
The length in the width direction, which is a direction orthogonal to the recording medium conveying direction by the recording medium conveying means, is variably provided, and for each recording medium having a different size, the recording medium is out of the size range corresponding to the size of each recording medium. It includes a wiping means set to a length capable of wiping off the excess fixing liquid applied to.

  In addition, the present invention includes a position adjusting unit that adjusts a position of at least one of the photosensitive drum and the toner image carrier so that the photosensitive drum and the toner image carrier can be separated from each other. .

  The present invention is also characterized in that it includes a photoconductor cleaning means for removing the fixing solution adhering to the photoconductor drum.

The present invention also provides an intermediate transfer medium on which a toner image formed on a photosensitive drum is temporarily transferred by a toner image forming unit, and the toner image is transferred to and supported on a toner image carrier.
And an intermediate transfer medium cleaning unit that removes the fixing liquid of the intermediate transfer medium attached by the transfer of the toner image to the toner image carrier.

  In addition, the present invention includes a heating unit that heats the toner image before the fixing solution is applied by the fixing solution applying unit to a temperature higher than the glass transition point of the toner.

  The present invention also relates to a length of a straight line connecting ends located on the outermost sides of a region where the fixing liquid is removed by the fixing liquid removing means in the width direction that is a direction perpendicular to the recording medium conveying direction of the recording medium conveying means. Is longer than the length in the width direction of the region to which the fixing solution is applied by the fixing solution applying means.

  In the present invention, the length of the region where the fixing liquid is applied by the fixing liquid applying unit in the width direction that is a direction orthogonal to the recording medium conveying direction of the recording medium conveying unit is greater than the length of the photosensitive drum in the width direction. It is also characterized by its long length.

  According to the present invention, there is provided an image forming apparatus including a toner image forming unit including a photosensitive drum, a toner image carrier, a fixing liquid applying unit, a recording medium conveying unit, and a fixing unit. There is provided an image forming apparatus including a size detecting unit for detecting a size and a fixing solution removing unit for removing excess fixing solution applied outside the size range of the recording medium detected by the size detecting unit. According to the fixing liquid removing unit provided in such an image forming apparatus, the fixing liquid applied to the formed toner image is applied outside the size range of the recording medium detected by the size detecting unit without removing the fixing liquid. Therefore, the excess fixing liquid applied outside the size range of the recording medium is removed without disturbing the formed toner image, and the recording medium is contaminated or wrinkled by the adhesion of the excessive fixing liquid. Etc. can be prevented.

  According to the invention, the toner image carrier is a recording medium carried by the recording medium conveying means, and the fixing liquid removing means is provided upstream of the fixing means in the recording medium conveying direction of the recording medium conveying means. Then, before the toner image is fixed on the recording medium by the fixing unit, the fixing solution adhering to the recording medium conveying unit, which is an excess fixing solution applied outside the size range of the recording medium, is removed. In such an image forming apparatus, before the toner image is fixed on the recording medium by the fixing unit, only the excess fixing solution that is applied by the fixing solution applying unit and adheres to the recording medium transport unit is removed from the fixing solution. It can be removed by means. Accordingly, the fixing liquid applied to the portion of the toner image carried on the recording medium is not removed, so that the toner image is not disturbed. Further, by removing the excess fixing liquid adhering to the recording medium conveying means before fixing the toner image on the recording medium, it is possible to prevent the excessive fixing liquid from adhering to the fixing means in advance, and the next image formation. Even when a recording medium having a large size is carried and conveyed by the recording medium conveying means and the fixing means and the recording medium come into contact with each other, the fixing liquid does not adhere to the back surface of the recording medium.

  According to the invention, the toner image carrier is a rotation driving member that carries and rotates the toner image, and the fixing liquid removing means is provided upstream of the fixing means in the rotation direction of the toner image carrier, and is fixed. Before the toner image is fixed on the recording medium by the means, the excess fixing liquid on the surface of the toner image carrier applied outside the size range of the recording medium is removed. In such an image forming apparatus, before the toner image is transferred and fixed on the recording medium by the fixing unit, only the excess fixing solution applied by the fixing solution applying unit and attached to the toner image carrier is removed by the fixing solution removing unit. it can. Therefore, the fixing liquid applied to the portion of the toner image carried on the toner image carrier is not removed, and the toner image is not disturbed. Further, since the excess fixing liquid adhering to the toner image carrier can be removed before the transfer and fixing of the toner image onto the recording medium, it is possible to prevent the fixing liquid from adhering to the fixing means, and the next image formation. Even when a large-sized recording medium used sometimes and the fixing means come into contact with each other, the fixing liquid does not adhere to the back surface of the recording medium.

  According to the invention, the toner image carrier is a recording medium carried by the recording medium conveying means, and the fixing liquid removing means is provided downstream of the fixing means in the recording medium conveying direction of the recording medium conveying means, After the toner image is fixed on the recording medium by the fixing unit, the excess fixing liquid applied outside the size range of the recording medium and remaining fixing liquid adhering to the recording medium conveying unit is removed. In the present invention, the residual fixing solution is an excess fixing solution applied outside the size range of the recording medium, and is applied outside the size range of the recording medium, and the fixing solution is removed after fixing the toner image on the recording medium. Including the fixing liquid remaining on the object (recording medium conveying means and toner image carrier). In such an image forming apparatus, after the toner image is fixed on the recording medium by the fixing unit, the excess fixing liquid outside the size range of the recording medium applied to the recording medium by the fixing liquid applying unit, the recording medium being Fixing liquid remaining on and adhering to the recording medium conveying means after being conveyed can be removed by the fixing liquid removing means. Accordingly, since the fixing liquid applied to the toner image on the recording medium is not removed, the toner image is not disturbed.

  According to the invention, the toner image carrier is a rotation driving member that carries and rotates the toner image, and the fixing liquid removing means is provided downstream of the fixing means in the rotation direction of the toner image carrier, and is fixed. After the toner image is fixed on the recording medium by the means, the excess fixing liquid adhering outside the recording medium size range on the surface of the toner image carrier is removed. In such an image forming apparatus, after the toner image is transferred and fixed on the recording medium by the fixing unit, the excess fixing liquid outside the size range of the recording medium remaining on and adhered to the toner image carrier is removed by the fixing liquid removing unit. can do. Therefore, since the fixing liquid applied to the toner image on the toner image carrier is not removed, the toner image is not disturbed.

  According to the present invention, the image forming apparatus further includes another fixing solution removing unit that removes the fixing solution adhering to the fixing unit by fixing the toner image to which the fixing solution is applied. In such an image forming apparatus, even if the fixing solution adheres to the fixing unit due to contact between the fixing unit and the toner image carrier, the fixing solution attached to the fixing unit is removed by another fixing solution applying unit. Therefore, adhesion of the fixing liquid to the back surface of the recording medium due to contact between the fixing unit and the recording medium can be prevented, and contamination or wrinkling of the recording medium can be prevented.

  According to the invention, the fixing solution removing unit includes a heating removing unit that heats and fixes the fixing solution to remove. Such a heat removal means removes the fixing solution by evaporating the solvent contained in the fixing solution. The fixing liquid from which the solvent has evaporated does not easily adhere to the recording medium, and even if it adheres, there is no risk of wrinkling of the recording medium. Further, even if the fixing liquid is applied to the toner image carried on the toner image carrier and the fixing liquid adheres to other members and reaches the photosensitive drum, the solvent is evaporated. There is no risk of missing images.

  According to the invention, the fixing solution removing means includes a blade-shaped removing member that scrapes and removes the fixing solution. The fixing solution removing means including such a blade-shaped removing member has a simple configuration and can collect and reuse the removed fixing solution.

  According to the invention, the fixing solution removing means includes a roller-shaped removing member that adsorbs and removes the fixing solution. The roller-shaped removal member can reliably and easily remove the fixing liquid by selecting the material.

  According to the invention, the fixing solution removing means includes a strip-shaped removing member that adsorbs and removes the fixing solution. The strip-shaped removing member can remove the fixing solution reliably and easily, and even if the removed fixing solution adheres to the removing member, the attached fixing solution can be removed by drying at room temperature in a short time. Therefore, it is not necessary to provide a means for further removing the fixing liquid adhering to the removing member.

  According to the invention, the roller-shaped or belt-shaped removal member has a contact angle of the fixing solution smaller than that of the fixing solution with respect to the toner image carrier. Since such a removing member adheres the fixer more easily than the object from which the fixer is removed, that is, the recording medium conveying means or the toner image carrier, the fixer can be removed more reliably. it can.

  Further, according to the present invention, since the roller-shaped or belt-shaped removing member is made of a liquid-absorbing material, the fixing liquid can be easily absorbed and the fixing liquid can be removed more reliably.

  According to the invention, the fixing solution removing means includes suction removing means for sucking and removing the fixing solution. When such a fixing solution removing unit is used, the fixing solution is removed by suction, and the fixing solution does not scatter. Therefore, it is possible to prevent the fixing solution from scattering into the apparatus and to provide a member such as a scatter prevention cover. There is no.

  According to the invention, the fixing liquid removing means corresponds to a predetermined size of the recording medium, and is provided so as to wipe off and remove the excess fixing liquid applied outside the recording medium size range. Including wiping means. Such a fixing solution removing unit can easily remove only the excess fixing solution applied outside the size range of the recording medium in accordance with the sizes of the plurality of recording media, and is wiped within the recording medium size range. Since the means and the object from which the fixing liquid is removed do not come into contact, it can be suitably used as a fixing liquid removing means that removes the toner image on the recording medium before fixing.

  According to the invention, the fixing liquid removing means is provided with a variable length in the width direction, which is a direction orthogonal to the recording medium conveyance direction by the recording medium conveyance means, and for each recording medium having a different size. Corresponding to the size of the recording medium, and includes a wiping means set to a length capable of wiping off the excess fixing liquid applied outside the size range of the recording medium. Such fixing solution removing means can change the length in the width direction according to the size of the plurality of recording media, and can easily remove only the excess fixing solution applied outside the size range of the recording media, When removing the fixing liquid, the wiping means and the object from which the fixing liquid is removed do not come into contact within the size range of the recording medium, so that the fixing liquid means is removed particularly before fixing the toner image on the recording medium. Can be suitably used.

  In addition, according to the present invention, the paper includes the position adjusting means for adjusting at least one of the position of the photosensitive drum and the toner image carrier so that the photosensitive drum and the toner image carrier can be separated from each other. Even when the fixing liquid of the toner image carrier is not removed due to a malfunction of the device such as clogging, the photosensitive drum and the toner image carrier are separated from each other so that they are not in contact with each other. It is possible to prevent adhesion of the fixing solution.

  Further, according to the present invention, since the photoconductor cleaning means for removing the fixing liquid adhering to the photoconductive drum is included, the fixing liquid of the toner image carrier is not removed due to a malfunction of the apparatus such as a paper jam, and the photoconductive drum is not removed. Even when the fixing solution has adhered, the fixing solution adhering to the photosensitive drum can be removed, and the occurrence of image loss or the like can be prevented.

  According to the invention, the toner image formed on the photosensitive drum is once transferred by the toner image forming unit, and the toner image is transferred to and supported on the toner image carrier, and the toner image carrier. And an intermediate transfer medium cleaning means for removing the fixing liquid of the intermediate transfer medium attached by the transfer of the toner image to the toner image. When the toner image formed on the photosensitive drum is transferred to the toner image carrier through the intermediate transfer medium, the fixing liquid may adhere to the intermediate transfer medium. The fixing solution adhering to the intermediate transfer medium can be removed, and adhesion of the fixing solution to the photosensitive drum can be more reliably prevented.

  In addition, according to the present invention, the image forming apparatus includes the heating unit that heats the toner image before the fixing solution is applied by the fixing solution applying unit to a temperature higher than the glass transition point of the toner. When the toner image before the fixing solution is applied is heated to a temperature higher than the glass transition point of the toner, components such as a binder resin and wax contained in the toner are softened, and the binding force between the toners is increased. Therefore, even when the fixing liquid is applied in contact with, for example, a roller that contacts the toner image, the toner image can be prevented from being disturbed by the toner adhering to the roller.

  According to the invention, the straight line connecting the ends located on the outermost sides of the region where the fixing liquid is removed by the fixing liquid removing means in the width direction that is a direction orthogonal to the recording medium conveying direction of the recording medium conveying means. Is longer than the length in the width direction of the region to which the fixing liquid is applied by the fixing liquid applying means. In general, the fixer applied by the fixer applying unit tends to accumulate at the end of the application region, and the amount of liquid at the end often increases. Further, when the length in the width direction of the fixing liquid removing unit is equal to the length in the width direction of the fixing liquid application area or shorter than the length in the width direction of the fixing liquid application area, the fixing attached to the end of the fixing liquid application area It is difficult to completely remove the liquid. In the present invention, since the length in the width direction of the region from which the fixing solution is removed is longer than the length of the region to which the fixing solution is applied, the fixing solution existing at the end of the fixing solution application region is also sufficiently removed. The fixing solution can be reliably removed from the toner image carrier.

  According to the invention, the length of the region where the fixing liquid is applied by the fixing liquid applying means in the width direction that is a direction orthogonal to the recording medium conveying direction of the recording medium conveying means is the width direction of the photosensitive drum. Longer than the length. As described above, it is difficult to completely remove the fixing solution adhering to the end portion of the fixing solution application region, but if the end portion of the fixing solution application region is longer than the length in the width direction of the photosensitive drum. Even if the fixing liquid adheres to and accumulates at the end of the fixing liquid application area, the end exists outside the both ends in the width direction of the photosensitive drum, so that the fixing liquid does not adhere to the photosensitive drum. Can be prevented.

  The image forming apparatus of the present invention includes a photosensitive drum that is exposed to light corresponding to image information to form an electrostatic latent image on the surface thereof, and is sensitive to a toner image made of dry toner containing a binder resin and a colorant. A toner image forming unit formed on the photosensitive drum, a toner image formed on the photosensitive drum is transferred, a toner image carrier that carries the transferred toner image, and a toner image on the toner image carrier. A fixing solution applying unit that applies a fixing solution that softens and / or swells the toner, a recording medium transfer unit that supports and conveys the recording medium, and a toner image carrier. A fixing means for fixing the toner image to which the toner image is applied to the recording medium, a size detecting means for detecting the size of the recording medium, and a surplus provided outside the size range of the recording medium detected by the size detecting means. Characterized in that it comprises a fixing solution removing means for removing Chakueki.

  FIG. 1 is a diagram schematically showing a configuration of an image forming apparatus 1 according to a first embodiment of the present invention, and FIG. 2 is a main part (image forming unit 10y described later) of the image forming apparatus 1 shown in FIG. FIG. 3 is an enlarged view showing a configuration of a main part (a transfer fixing unit 4 described later) of the image forming apparatus 1 shown in FIG. The image forming apparatus 1 is an image forming apparatus having a so-called tandem configuration in which toner images of four colors of yellow, magenta, cyan, and black are sequentially superimposed and transferred.

  The image forming apparatus 1 includes a toner image forming unit 2, an intermediate transfer unit 3, a transfer fixing unit 4, a constant recording medium transport unit 5, and a discharge unit 6.

  The toner image forming unit 2 includes image forming units 10y, 10m, 10c, and 10b, which form an electrostatic latent image corresponding to image information of each hue, develop the electrostatic latent image, and develop each electrostatic color image. A toner image is formed. That is, the image forming unit 10y forms a toner image corresponding to yellow image information, the image forming unit 10m forms a toner image corresponding to magenta image information, and the image forming unit 10c uses cyan image information. The image forming unit 10b forms a toner image corresponding to black image information.

  The image forming unit 10y includes a photosensitive drum 11y, a charging roller 12y, an optical scanning unit 13, a developing device 14y, a drum cleaner 15y, and a fixer cleaner 16y.

  The photosensitive drum 11y is supported by a driving unit (not shown) so as to be rotatable around an axis, and is formed on a cylindrical or columnar (preferably cylindrical) conductive substrate (not shown) and the surface of the conductive substrate. And a photosensitive layer. As the photosensitive drum 11y, those commonly used in this field can be used. For example, the photosensitive drum 11y is connected to a GND potential including an aluminum base tube as a conductive substrate and an organic photosensitive layer formed on the surface of the aluminum base tube. And a photosensitive drum having a diameter of 30 mm. The organic photosensitive layer is formed by laminating a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material. The organic photosensitive layer may include a charge generation material and a charge transport material in one layer. The layer thickness of the organic photosensitive layer is, for example, 20 μm. An underlayer may be provided between the organic photosensitive layer and the conductive substrate. Further, a protective layer may be provided on the surface of the organic photosensitive layer. Instead of the organic photosensitive layer, a photosensitive layer made of zinc oxide, selenium, amorphous silicon or the like can be used. The photosensitive drum 11y is rotationally driven in a clockwise direction, for example, at a peripheral speed of 100 mm / s.

  The charging roller 12y charges the surface of the photosensitive drum 11y to a predetermined polarity and potential. Instead of the charging roller 12y, a brush type charger, a charger type charger, a corona charger such as a scorotron, or the like can be used. In the present embodiment, the photosensitive drum 11y is charged to −600 V by the charging roller 12y.

  The optical scanning unit 13 irradiates the surface of the photosensitive drum 11y to be charged with laser light 13y corresponding to yellow image information, and electrostatically corresponds to the yellow image information on the surface of the photosensitive drum 11y. A latent image is formed. A semiconductor laser or the like is used as the light source of the optical scanning unit 13. In the present embodiment, an electrostatic latent image having an exposure potential of −70 V is formed.

  The developing device 14y is in pressure contact with the surface of the photosensitive drum 11y, includes a fixed magnetic pole (not shown), and is rotatably driven around an axis, and supplies yellow toner 17y to the electrostatic latent image on the surface of the photosensitive drum 11y. A developing roller 18y, a developing blade 19y that is provided so as to be in contact with the surface of the developing roller 18y, uniformizes (layer regulation) the yellow toner layer on the surface of the developing roller 18y, and a toner storage container that stores the yellow toner 17y. 20y and agitation rollers 21a and 21b provided inside the toner storage container 20y so as to be in pressure contact with each other and rotatably driven around the axis, the agitation roller 21a being in pressure contact with the surface of the developing roller 18y and the surface of the developing roller 18y And stirring rollers 21a and 21b for supplying yellow toner 17y.

  The developing roller 18y is rotationally driven in the same direction as the rotational driving direction of the photosensitive drum 11y at the developing nip portion that is in pressure contact (contact) with the photosensitive drum 11y. Therefore, the rotational drive direction around the axis is the opposite direction. In the present embodiment, the peripheral speed of the developing roller 18y is, for example, 150 mm / s, which is 1.5 times the peripheral speed of the photosensitive drum 11y. In the present embodiment, a DC voltage of −240 V is applied to the developing roller 11y as the developing potential. The yellow toner 17y in the toner storage container 20y is mixed with a magnetic carrier (not shown) by the stirring rollers 21a and 21b, then supplied to the surface of the developing roller 18y, and the layer thickness is made uniform by the developing blade 19y. The toner image corresponding to the yellow image information is formed by selectively supplying the electrostatic latent image on the surface of the photosensitive drum 11y almost selectively.

  The drum cleaner 15y removes and collects the yellow toner remaining on the surface after the yellow toner image on the surface of the photosensitive drum 11y is transferred to the intermediate transfer belt 32, as will be described later.

  FIG. 4 is a side view showing an outline of the configuration and operation of the fixer cleaner 16y. The fixer cleaner 16y suddenly adheres to the intermediate transfer belt 32 due to a paper jam or the like, and removes the fixer 8 attached to the surface of the photosensitive drum 11y via the intermediate transfer belt 32. The fixer cleaner 16y adheres to the photoconductor drum 11y while the fixer is wet, and the next portion of the image formation cannot be developed and prevents image loss.

  The fixer cleaner 16y is formed in a roller shape, and a removal member 22y having bearings 23y at the axial center portions of both end faces in the longitudinal direction (direction perpendicular to the paper surface), and the removal member 22y around the axis. And a position adjusting unit 24y that supports the photosensitive drum 11y so as to be able to rotate and to be separated and approachable.

  As the removing member 22y, a sponge roller extending in parallel with the longitudinal direction of the photosensitive drum 11y is used. As the sponge roller, for example, a draining sponge roller disclosed in Japanese Patent No. 2524968 can be used. Such a sponge roller includes a metal shaft core and a porous layer formed on the surface of the shaft core. Examples of the metal used for the shaft core include stainless steel. Examples of the porous layer include open cell bodies made of polyvinyl alcohol (PVA), polyvinyl chloride (PVC), and the like.

  The position adjusting unit 24y includes a support plate 25y, an eccentric cam 26y, a pressing spring 27y, a base 28y, and a protrusion 29y.

  The support plate 25y is a pair of plate-like support members that face the circumferential surface of the photosensitive drum 11y and are provided at a predetermined distance. The support plate 25y has a bearing receiver (not shown) that supports the bearing 23y of the removal member 22y at the end in the longitudinal direction facing the photoreceptor drum 11y, and supports the removal member 22y so as to be rotatable in its axial direction. The support plate 25y has an opening 31y that passes through the rotation shaft 30y of the eccentric cam 26y and prevents the rotation of the eccentric cam 26y from being interfered by the support plate 25y. Further, the support plate 25y has a protruding portion 29y provided perpendicularly to the surface in the thickness direction at the end portion in the longitudinal direction. The support plate 25y is provided so as to be movable only in a direction linearly separating or approaching the photosensitive drum 11y by a guide member (not shown).

  As described above, the eccentric cam 26y is inserted into the opening 31y provided on the support plate 25y. The rotating shaft 30y extends further outward from the opening 31y and is supported by a bearing (not shown). A motor (not shown) is connected to the eccentric cam 26y, and the eccentric cam 26y is rotated by the motor. Although a general motor can be used as the motor used here, a pulse motor is preferable in consideration of control of the rotational position. Since the rotation angle of the pulse motor can be controlled by the number of steps, the eccentric cam 26y can be stopped at a desired position. In order to change the state in which the photosensitive drum 11y and the removal member 22y are in contact with each other, the rotation amount of the rotary shaft 30y may be set to 180 °, for example.

  One end of the pressing spring 27y in the longitudinal direction is supported by the support plate 25y, and the other end is fixed to the base 28y.

  The base 28y is fixedly provided inside the image forming apparatus 1 by a support member (not shown).

  The rotation shaft 30y, the photosensitive drum 11y, and the base 28y are supported by the same member so that the relative position between the rotation shaft 30y and the photosensitive drum 11y and the relative position between the rotation shaft 30y and the base 28y do not change. It is preferable.

  The position adjusting unit 24y changes the position of the removing member 22y as follows. First, as shown in FIG. 4A, the rotating shaft 30y of the eccentric cam 26y is rotated to bring the eccentric cam 26y into contact with the protruding portion 29y formed on the support plate 25y. The pressing spring 27y is changed from the natural state to the compressed state by the pressing force. For this reason, the support plate 25y to which the removing member 22y is fixed moves to the base 28y side, and the removing member 22y is separated from the photosensitive drum 11y. When the rotating shaft 30y of the eccentric cam 26y is further rotated or rotated in the opposite direction, as shown in FIG. 4B, the eccentric cam 26y is separated from the protrusion 29y, and the pressing spring 27y is compressed. To return to the natural state. For this reason, the support plate 25y to which the removing member 22y is fixed is separated from the base 28y side, and the removing member 22y comes into pressure contact with the photosensitive drum 11y.

  During normal image formation, the removal member 22y is disposed so as to be separated from the photosensitive drum 11y, and the fixer cleaner 16y does not perform a cleaning operation. The cleaning operation by the fixing liquid cleaner 16y is, for example, when the user finds that the formed image is missing due to adhesion of the fixing liquid, the photosensitive drum 11y (and the photosensitive drums 11m, 11c, and 11b) is cleaned by the operation panel or the like. Starts when you choose to do and activate the cleaning mode. When the cleaning mode is activated, the removing member 22y is brought into contact with the photosensitive drum 11y by the position adjusting unit 24y, and the fixing liquid adhering to the photosensitive drum 11y is removed. When the fixing liquid is removed, the removing member 22y is moved again away from the photosensitive drum 11y by the position adjusting unit 24y, and the cleaning operation is finished.

  In this way, the fixing liquid cleaner 16y does not clean the photosensitive drum 11y during normal image formation, and only cleans the photosensitive drum 11y when the cleaning mode is activated. As a result, when the fixing liquid is not attached, the photosensitive drum 11y is not cleaned and the removal member 22y is separated from the photosensitive drum 11y. Therefore, the pressure contact between the photosensitive drum 11y and the removal member 22y is performed. It is possible to prevent the photosensitive drum 11y from being worn or scratched.

  According to the image forming unit 10y, the surface of the photosensitive drum 11y is first charged to, for example, -600V by the charging roller 12y while the photosensitive drum 11y is rotated about its axis. Next, the surface of the charged photosensitive drum 11y is irradiated with signal light corresponding to yellow image information from the optical scanning unit 13, and an electrostatic latent having an exposure potential of −70 V corresponding to the yellow image information. Form an image. Next, the yellow toner layer carried on the surface of the developing roller 16y comes into contact with the surface of the photosensitive drum 11y. A DC voltage of −240 V is applied to the developing roller 16y as a developing potential. Due to the potential difference, the yellow toner 17y adheres to the electrostatic latent image and is developed, and a yellow toner image is formed on the surface of the photosensitive drum 11y. Is formed. As will be described later, this yellow toner image is intermediately transferred to an intermediate transfer belt 32 in contact with the surface of the photosensitive drum 11y. The yellow toner 17y remaining on the surface of the photosensitive drum 11y is removed and collected by the drum cleaner 15y. Thereafter, the same yellow toner image forming operation is repeatedly executed.

  Each of the image forming units 10m, 10c, and 10b has a similar structure to the image forming unit 10y except that magenta toner, cyan toner, or black toner is used. At the end of the reference symbol, “m” indicating magenta, “c” indicating cyan, or “b” indicating black is omitted, and description thereof is omitted. The image forming units 10y, 10m, 10c, and 10b are arranged in this order from the upstream side in the direction of movement of the intermediate transfer belt 32 (sub operation direction) included in the intermediate transfer unit 3 described later, that is, the direction of the arrow 32b. Arranged.

  Each of the color toners 17y, 17m, 17c, and 17b contains a binder resin, a colorant, and, if necessary, a release agent. Hereinafter, the toners 17y, 17m, 17c, and 17b are collectively referred to as the toner 17 unless otherwise specified.

  The binder resin is not particularly limited as long as it is a resin that is softened and / or swelled by the fixing solution 8 to be described later. For example, polystyrene, a homopolymer of a substituted styrene, a styrene copolymer, polyvinyl chloride, Examples thereof include polyvinyl acetate, polyethylene, polypropylene, polyester, and polyurethane. Binder resins can be used alone or in combination of two or more.

  As the colorant, although pigments and dyes for toners conventionally used in electrophotographic image forming technology can be used, a pigment that does not dissolve in the fixing solution 8 is preferable in order to prevent bleeding by the fixing solution 8, and a nigrosine dye Dyes such as are not preferred. Specific examples of the pigment include, for example, azo pigments, benzimidazolone pigments, quinacridone pigments, phthalocyanine pigments, isoindolinone pigments, isoindoline pigments, dioxazine pigments, anthraquinone pigments, perylene pigments, Organic pigments such as perinone pigments, thioindigo pigments, quinophthalone pigments, metal complex pigments, inorganic pigments such as carbon black, titanium oxide, molybdenum red, chromium yellow, titanium yellow, chromium oxide, Berlin blue, aluminum powder And metal powders.

  The release agent is not particularly limited as long as it is softened and / or swollen by the fixing solution 8 described later, and examples thereof include waxes such as polyethylene wax, polypropylene wax, and paraffin wax. Among these waxes, it is preferable to use a wax having a glass transition point lower than that of the binder resin depending on the binder resin to be used. Wax having a glass transition point lower than that of the binder resin is easily softened by heating. Therefore, even at a temperature lower than the softening point of the toner 17 itself, the binding force between the toners 17 and the toner image carrier of the toner 17, the recording medium 7, etc. Since the adhesion force to the toner increases, it is possible to reduce the occurrence of the flow and aggregation of the toner 17 when the fixing solution is applied. Further, the softening of the wax causes the fixing liquid 8 to permeate into the toner particles from the wax-existing portion of the toner particles. Therefore, after the fixing liquid 8 is applied, the entire toner 17 is softened and / or swelled in a short time. As a result, at the time of transfer and fixing to a recording medium, sufficient fixing strength can be obtained, and sufficient color development can be obtained by superimposing toner images.

  The toner 17 may contain one or more general toner additives such as a charge control agent, a fluidity improver, a fixing accelerator, and a conductive agent as necessary.

  The volume average particle diameter of the toner 17 is not particularly limited, but is preferably 2 to 7 μm. When such a small particle size toner is used, the surface area of the toner 17 per unit weight is increased, the contact area with the fixing liquid 8 is increased, and fixing is facilitated. As a result, the amount of the fixing liquid 8 used can be reduced, and the fixing of the toner image onto the recording medium and the drying after the fixing can be performed in a short time. Further, the smaller the volume average particle diameter of the toner 17 is, the higher the coverage with respect to the recording medium 7 is. Therefore, it is possible to achieve a high image quality with a low adhesion amount and a reduction in the consumption amount of the toner 17. Further reduction in consumption can be achieved.

  When the volume average particle diameter of the toner 17 is less than 2 μm, the fluidity of the toner 17 is lowered, and during the developing operation, the supply, stirring and charging of the toner 17 become insufficient, the amount of the toner 17 is insufficient, and the reverse polarity toner. There is a possibility that high quality images cannot be obtained. On the other hand, if the volume average particle size exceeds 7 μm, the toner particles having a large particle size that is difficult to soften and / or swell to the center of the toner particles increase, so that the fixability of the image to the recording medium is reduced and the image Color development deteriorates, and the image becomes dark particularly when fixing to an OHP film.

  Although the softening point and glass transition point of the toner 17 itself are not particularly limited, the softening point is preferably 80 to 130 ° C. and the glass transition point is preferably 50 to 80 ° C. Such a toner having a high softening point has high durability against a load during development, but does not sufficiently fix and develop color in the heat fixing method. However, in the present invention, since the toner 17 is chemically swollen and softened using the fixing liquid 8, fixing and color development are sufficient, and a high-quality image can be obtained.

  The toner 17 can be manufactured according to a known method. For example, a method of dispersing and pulverizing a colorant and a release agent in a binder resin, a method of dispersing a colorant and a release agent in a binder resin monomer solution, and then polymerizing the binder resin monomer Etc. In any method, in order to increase the surface area of the toner 17, it is preferable to adjust the shape of the toner 17 to be indefinite rather than spherical. This facilitates contact with the fixing liquid 8, so that the amount of the fixing liquid 8 used can be reduced and the toner image can be fixed and dried in a short time.

Each color toner 17y, 17m, 17c, and 17b used in the present embodiment has the same configuration as described below except for the pigment. This toner contains a binder resin, a colorant and a release agent, and has a volume average particle size of 6 μm, a glass transition point of 60 ° C., a softening point of 120 ° C., a pigment content of 12% by weight of the total amount of toner, and a wax as a release agent. This is a negatively chargeable insulating nonmagnetic toner having a content of 7% by weight of the total amount of toner and the balance being a binder resin. Using this toner, the amount of toner per unit area required to obtain a predetermined image density (the measured value of reflection density by X-Rite 310 is 1.4) is 5 g / m ² .

  The intermediate transfer unit 3 includes an intermediate transfer belt 32 that is an intermediate transfer medium, intermediate transfer rollers 33y, 33m, 33c, and 33b, a driving roller 34, a tension roller 35, and a belt cleaner 36.

  On the intermediate transfer belt 32, the toner image formed on the photoreceptors 11y, 11m, 11c, and 11b is temporarily transferred by the toner image forming unit 2, and the toner image is transferred to a transfer fixing roller 42 that is a toner image carrier described later. An intermediate transfer medium to be transferred and carried. The intermediate transfer belt 32 is an endless belt that is stretched between the driving roller 34 and the tension roller 35 to form a loop-shaped movement path, and has an arrow at almost the same speed as the photosensitive drums 11y, 11m, 11c, and 11b. It rotates in the direction of the mark 32b.

  As the intermediate transfer belt 32, a belt commonly used in this field can be used, and examples thereof include a belt in which a fluororesin layer is provided on a polyimide base material.

  A toner image transfer surface 32a, which is a surface on the side to which the toner image is transferred, of the intermediate transfer belt 32 is pressed against the photosensitive drums 11y, 11m, 11c, and 11b in this order. The positions where the intermediate transfer belt 32 is in pressure contact with the photosensitive drums 11y, 11m, 11c, and 11b are the intermediate transfer positions of the toner images of the respective hues. Intermediate transfer rollers 33y, 33m, 33c, and 33b are disposed at positions that face the photosensitive drums 11y, 11m, 11c, and 11b with the intermediate transfer belt 32 interposed therebetween.

  The intermediate transfer rollers 33y, 33m, 33c, and 33b are respectively brought into pressure contact with the surface opposite to the toner image transfer surface 32a of the intermediate transfer belt 32 and can be driven to rotate around its axis by a driving unit (not shown). A metal shaft body and a conductive layer coated on the surface of the metal shaft body are configured. The shaft body is formed of a metal such as stainless steel, for example. The diameter of the shaft body is not particularly limited, but is preferably 8 to 10 mm. The conductive layer is formed of a conductive elastic body or the like. As the conductive elastic body, those commonly used in this field can be used, and examples thereof include EPDM (ethylene-propylene-diene terpolymer) containing a conductive material such as carbon black, foamed EPDM, and urethane foam. . A high voltage is uniformly applied to the intermediate transfer belt 32 by the conductive layer.

  The intermediate transfer rollers 33y, 33m, 33c, and 33b are opposite to the charging polarity of the toner in order to transfer the toner images formed on the surfaces of the photosensitive drums 11y, 11m, 11c, and 11b onto the intermediate transfer belt 32. A polar intermediate transfer bias, for example, +1 kV bias is applied by constant voltage control. As a result, the yellow, magenta, cyan, and black toner images formed on the photosensitive drums 11y, 11m, 11c, and 11b are sequentially superimposed on the toner image transfer surface 32a of the intermediate transfer belt 32. Transferred to form a multicolor toner image.

  The driving roller 34 is provided so as to be rotatable around an axis by a driving means (not shown). As the drive roller 34, for example, a hollow roller made of a metal such as aluminum, a roller configured to include a metal shaft body and a coating layer formed on the surface of the metal shaft body can be used.

  The tension roller 35 applies a predetermined tension to the intermediate transfer belt 32 so that the intermediate transfer belt 32 does not sag. The tension roller 35 includes, for example, a metal shaft body and a coating layer formed on the surface of the metal shaft body. Moreover, what consists only of metal shaft bodies may be sufficient. For example, stainless steel is used as the material of the metal shaft, and fluororubber is used as the material of the coating layer. Moreover, a metal hollow roller may be used.

  The belt cleaner 36 transfers the toner image on the toner image transfer surface 32a of the intermediate transfer belt 32 to a transfer fixing roller 42 described later, and then adheres to the toner remaining on the toner image transfer surface 32a and the toner image transfer surface 32a. A member for removing the fixing liquid 8 is provided so as to face the tension roller 35 with the intermediate transfer belt 32 interposed therebetween, and is pressed against the toner image transfer surface 32a of the intermediate transfer belt 32 by a pressing means (not shown). It includes a cleaning blade 36a that scrapes off residual toner and the like on the toner image transfer surface 32a, and a toner storage container 36b that stores toner and the like scraped off by the cleaning blade 36a. As the cleaning blade 36a, for example, a blade made of an elastic rubber material (for example, urethane rubber) can be used.

  According to the intermediate transfer unit 3, the toner images of the respective colors formed on the photosensitive drums 11 y, 11 m, 11 c, and 11 b are transferred while being superimposed on predetermined positions on the toner image transfer surface 32 a of the intermediate transfer belt 32. The toner image transferred to the intermediate transfer belt 32 is further transferred to the transfer fixing roller 42. After the toner image is transferred to the transfer fixing roller 42, the toner remaining on the intermediate transfer belt 32 is removed by the belt cleaner 36.

  In the present embodiment, an intermediate transfer belt separating means 37 that allows the intermediate transfer belt 32 to be separated from the photosensitive drums 11y, 11m, 11c, and 11b can be included.

  As described above, the image forming apparatus 1 according to the present embodiment includes the fixer cleaners 16y, 16m, 16c, and 16b, but the photosensitive drums 11y, 11m, 11c, and 11b are in contact with the intermediate transfer belt 32. Even when the photosensitive drums 11y, 11m, 11c, and 11b are cleaned, the fixing solution 8 attached to the intermediate transfer belt 32 again adheres to the photosensitive drums 11y, 11m, 11c, and 11b, and the cleaning effect is improved. There is a risk that it will not be obtained. The intermediate transfer belt separating means 37 is provided to prevent this.

  FIG. 5 is a diagram showing an operation of separating the intermediate transfer belt 32 from the photosensitive drums 11y, 11m, 11c, and 11b. FIG. 6 is a diagram schematically showing the configuration of the intermediate transfer belt separating means 37. As shown in FIG. 5A, the intermediate transfer belt 32 is stretched around the driving roller 34 and the tension roller 35 and is in pressure contact with the photosensitive drums 11y, 11m, 11c, and 11b, as shown in FIG. On the other hand, when the cleaning operation is performed by the fixer cleaners 16y, 16m, 16c, and 16b, that is, when the cleaning mode is activated, the intermediate transfer rollers 33y, 33m, 33c, and 33b are separated from the photosensitive drums 11y, 11m, 11c, and 11b. Then, the intermediate transfer belt 32 stretched around the drive roller 34 and the tension roller 35 is separated from the photosensitive drums 11y, 11m, 11c, and 11b.

  The intermediate transfer belt separating means 37 includes a connection support member 38 that integrally supports the intermediate transfer rollers 33y, 33m, 33c, and 33b, and a position adjustment means 39 that is provided so as to contact both ends of the connection support member 38 in the longitudinal direction. , 40.

  The connection support member 38 is a pair of plate-like members, and is provided with a bearing that supports these shaft cores so as to correspond to the intervals between the intermediate transfer rollers 33y, 33m, 33c, and 33b, and these can be driven to rotate. To support. The intermediate transfer rollers 33y, 33m, 33c, and 33b are provided so as to come into contact with and separate from the intermediate transfer belt 32 by the coupling support member 38.

  The position adjusting means 39 and 40 are for causing the intermediate transfer rollers 33y, 33m, 33c and 33b to move away from the intermediate transfer belt 32 or to contact the intermediate transfer belt 32 together with the connection support member 38. The position adjusting means 39 and 40 have the same configuration as the position adjusting means 24y, and corresponding portions are denoted by the same reference numerals (however, the symbols y, m, c and b indicating colors are omitted). Description is omitted. The position adjusting means 39, 40 is the support plate in the position adjusting means 24 in that the support plate 41 abuts or adheres to both ends in the longitudinal direction of the connection support member 38 and does not have a bearing receiver for supporting the removal member. 25.

  The position adjusting means 39, 40 repeatedly perform the expansion and contraction operation by the rotation of the eccentric cam 26, and accordingly, the intermediate transfer rollers 33y, 33m, 33c, 33b supported integrally by the connection support member 38 are intermediate transfer rollers. The separation and approaching operations are performed on 32. The rotating shaft 30 and the base 28 of the eccentric cam 26 and the photosensitive drums 11y, 11m, 11c, and 11b in the position adjusting means 39 and 40 are integrally supported by the same member so that their relative positions are constant. It is preferable.

  As a result, the intermediate transfer belt 32 can be separated from the photosensitive drums 11y, 11m, 11c, and 11b, and the photosensitive drums 11y, 11m, 11c, and 11b and the intermediate transfer belt 32 are preferably not in contact with each other. The photoreceptors 11y, 11m, 11c, and 11b can be cleaned.

  The transfer fixing unit 4 includes a transfer fixing roller 42 that is a toner image carrier, a fixing solution applying unit 43, a fixing solution removing unit 44, a pressure roller 45 that is a fixing unit, and a transfer fixing roller cleaner 46. Consists of.

The transfer and fixing roller 42 is a toner image carrier that is a rotational driving member to which a toner image formed on the photosensitive drums 11y, 11m, 11c, and 11b is transferred and carries and rotates the transferred toner image. . The transfer fixing roller 42 includes, for example, a hollow roller made of carbon steel and having a thickness of 1 mm, a silicone rubber layer having a thickness of 3 mm and a volume resistivity of 10 ⁸ to 10 ⁹ Ω · cm formed on the surface of the hollow roller. Further, a roller having an outer diameter of 30 mm having a laminated structure including a coating layer made of PFA (copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether) having a thickness of 20 μm formed on the surface layer is used.

  A transfer bias having a polarity opposite to the charging polarity of the toner is applied between the transfer fixing roller 42 and the intermediate transfer belt 32 by a voltage application unit (not shown), and is formed on the toner image transfer surface 32 a of the intermediate transfer belt 32. The toner image is transferred to the transfer fixing roller.

  A temperature sensor 47 that detects the surface temperature of the transfer fixing roller 42 is provided on the surface of the transfer fixing roller 42 so as to be in contact with or close to the transfer fixing roller 42. The detection result by the temperature sensor 47 is stored in a CPU (not shown) that controls the entire operation of the image forming apparatus 1.

  A heater 48 such as a halogen lamp is provided inside the hollow roller of the transfer fixing roller 42. Based on the surface temperature of the transfer fixing roller 42 detected by the temperature sensor 47, the heater 48 is a temperature at which the surface temperature of the transfer fixing roller 42 is higher than the glass transition point of the toner by a control unit (not shown). In this embodiment, the operation of the heater 48 is controlled to be constant at 65 ° C. By the heating by the heater 48, the entire surface of the transfer fixing roller 42 is uniformly heated.

  Since the transfer fixing roller 42 includes such a heater 48, the wax in the toner 17 is softened immediately before the fixing liquid 8 is applied, and the adhesion between the toners 17 and between the toner 17 and the transfer fixing roller 42 is further increased. To increase. As a result, even when the fixing liquid 8 is applied in contact with the toner image, the toner image is disturbed when the fixing liquid 8 is applied, and the toner 17 is applied to the application roller 50 provided in the fixing liquid applying means 43. Adhesion can be prevented. Further, since the amount of heat that compensates for the temperature decrease of the transfer fixing roller 42 and the toner image due to the application of the fixing liquid 8 can be supplied on the spot, the temperature decrease of the transfer fixing roller 42, the toner image and the fixing liquid 8 immediately after the application can be prevented The fixer 8 can be quickly diffused and penetrated.

  Furthermore, the wax in the toner particles is softened, so that the fixing liquid 8 penetrates into the toner particles. As a result, the toner 17 is swollen and softened instantaneously over a wide range. Thereby, when the toner image is pressed against the recording medium 7 by a pressure roller 45 described later, sufficient fixing strength to the recording medium 7 can be obtained. Further, since the temperature of the fixing solution 8 after application increases, the fixing solution 8 can be dried in a short time after application. Thereby, the throughput which is the number of output sheets per unit time of the image forming apparatus can be further improved. Further, since the toner 17 instantaneously swells and softens, the time from the application of the fixing liquid 8 to the transfer to the recording medium 7 can be shortened, so that the application position of the fixing liquid 8 and the transfer position to the recording medium 7 can be reduced. Can be set short, which contributes to downsizing of the apparatus.

  Note that when the fluororesin layer is formed on the surface of the transfer fixing roller 42, since the adhesion with the toner 17 is low, almost the entire toner image is transferred to the recording medium 7. Further, when the transfer fixing roller 42 has a rubber layer, the surface layer is deformed following the unevenness of the recording medium 7, and the toner image can be brought into contact with the concave portion of the recording medium 7, thereby obtaining a uniform transfer fixed image. It is done.

  Further, when the transfer fixing roller 42 is formed of a material that does not penetrate the fixing liquid 8, the fixing liquid 8 is selectively applied only to the toner image, so that the fixing liquid 8 applied to a portion other than the toner image. Can be reduced. For this reason, the excessive fixing liquid 8 does not penetrate into the recording medium 7, it is possible to prevent the recording medium 7 from being wrinkled and curled, and to reduce the amount of the fixing liquid 8 used.

  The transfer fixing roller 42 is a member to which the toner image transferred to the intermediate transfer belt 32 is further transferred, and performs transfer fixing of the toner image onto the recording medium 7. Thus, by using the transfer fixing roller 42 that is not in direct contact with the photosensitive drums 11y, 11m, 11c, and 11b, the photosensitive drums 11y, 11m are heated when the toner image before the fixing liquid 8 is applied is heated. , 11c, 11b, etc., the temperature of members included in the toner image forming means 2 can be prevented. Further, even if there is a residual fixing liquid that could not be removed by the fixing liquid removing means 44 and the transfer fixing roller cleaner 46, the transfer fixing roller 42 does not directly contact the photosensitive drums 11y, 11m, 11c, and 11b. It is possible to further prevent the fixing solution from adhering to the photosensitive drums 11y, 11m, 11c, and 11b.

  The fixing liquid applying unit 43 applies a fixing liquid 8 that softens and / or swells the toner image carried on the transfer fixing roller 42 under contact. The fixing liquid applying unit 43 includes at least a part of a fixing liquid tank 49 that stores the fixing liquid 8, a coating roller 50 that applies the fixing liquid 8 stored in the fixing liquid tank 49 to the toner image on the surface of the transfer fixing roller 42. Is immersed in the fixing liquid 8 accommodated in the fixing liquid tank 49, pressed against the application roller 50 and supplied with the fixing liquid 8 to the application roller 50, and pressed against the surface of the application roller 50, and supplied roller 51, a regulating roller 52 that regulates the layer of the fixing liquid 8 carried on the coating roller 50, a pivot 53 that rotatably supports the fixing liquid tank 49 in the image forming apparatus 1, and a fixing liquid that is rotated by the pivot 53. The tank 49 includes a pressing spring 54 that holds the application roller 50 in a state where the application roller 50 is in pressure contact with the transfer fixing roller 42.

  In the fixing solution tank 49, the liquid level of the fixing solution 8 in the fixing solution tank 49 is made constant through the supply pipe 56 from the fixing solution storage tank 55 according to the consumption state of the fixing solution 8. Fixing liquid 8 is replenished and supplied.

  As the coating roller 50, for example, a roller having an outer diameter of 20 mm including a core metal having a diameter of 12 mm and an elastic layer made of ethylene propylene rubber formed on the surface of the core metal can be used. The application roller 50 is rotatably supported by a bearing (not shown) provided in the fixing liquid tank 49 with a rotation shaft (not shown) provided at both ends in the longitudinal direction of the core metal, and the transfer fixing roller 42 is rotated by a driving means (not shown). It rotates at the same speed and in the same direction at the nip portion with the transfer fixing roller 42.

  The material used for the elastic layer of the application roller 50 is not limited to the above-described material, and any material having elasticity and suitable for the surface of the fixing solution can be used. For example, a metal such as aluminum or a hydrophilic material can be used. A thin layer or coat layer of resin, a rubber material such as urethane rubber, or the like can be used. The elastic modulus of the applying roller 50 as the elastic layer is desirably smaller than the elastic modulus of the toner 17, preferably 1/10 or less, more preferably 1/100 or less of the elastic modulus of the toner 17. In the present embodiment, the elastic modulus of the elastic layer of the application roller 50 is 2 MPa which is 1/100 or less of the elastic modulus of the toner 17.

  The elastic layer of the application roller 50 is preferably lyophilic with respect to the fixing solution. The contact angle of the fixing liquid 8 showing the lyophilicity of the elastic layer with respect to the elastic layer is preferably 50 ° or less.

  The application roller 50 is provided such that the elastic layer on the surface thereof is lightly pressed against the transfer fixing roller 42. The pressing force of the application roller 50 against the transfer fixing roller 42 is preferably 0.05 to 1.0 N / cm in linear pressure. If it is less than 0.05 N / cm, the contact state between the coating roller 50 and the transfer and fixing roller 42 becomes unstable, and the fixing liquid 8 cannot be uniformly applied to the toner image. Furthermore, the coating roller 50 is not sufficiently elastically deformed following the fine unevenness of the transfer and fixing roller 42 and the unevenness of the toner image, so that it becomes insufficient to apply the fixing liquid 8 to the concave portion of the toner image. As a result, uneven application of the fixer 8, uneven fixing, gloss unevenness, color unevenness, and the like are caused. If it exceeds 1.0 N / cm, the fixing liquid 8 on the surface of the application roller 50 cannot pass through the nip portion in a state where the application roller 50 and the transfer fixing roller 42 rotate under pressure. As a result, the fixing solution 8 is squeezed at the nip portion, the fixing solution 8 forms a meniscus at the entrance of the nip portion, the excess fixing solution 8 returns to the upstream side in the rotation direction of the application roller 50, and the liquid is injected at the entrance of the nip portion. The toner flows violently and the toner image is disturbed. When a color image is obtained by superimposing a plurality of single color toner images of different colors, the absolute amount of toner increases, and the locations where much toner adheres and where the toner adheres are finely mixed and distributed. To do. For example, when three color toner images are superimposed, the height of the high density portion is three times higher than that of a single color toner image. For this reason, it is particularly important to apply the fixing liquid 8 in accordance with the amount of toner by the application roller 50 that makes contact with a certain pressing force and has elasticity. In the present embodiment, the pressing force of the application roller 50 against the transfer fixing roller 42 is 0.5 N / cm.

  Since the application roller 50 is configured to apply the fixing solution 8 to the transfer fixing roller 42 in contact and does not directly contact the recording medium 7, when the recording medium 7 is paper, paper powder such as cellulose fiber is used. Clogging caused by adhering to the surface of the application roller 50 does not occur. Therefore, nonuniform application of the fixing liquid 8 due to clogging does not occur, and a high-quality image can be stably obtained over a long period of time.

  The supply roller 51 is provided so as to be at least partially immersed in the fixing solution 8 accommodated in the fixing solution tank 49 and pressed against the application roller 50. As the supply roller 51, for example, a sponge roller obtained by laminating open-cell foamed urethane with a thickness of 5 mm on a core metal having a diameter of 10 mm can be used. The supply roller 51 rotates following the rotation of the application roller 50, and supplies the fixing liquid 8 stored in the fixing liquid tank 49 to the application roller 50.

  The regulation roller 52 is provided in pressure contact with the application roller 50 on the downstream side of the supply roller 51 in the direction in which the application roller 50 is driven and rotated. As the regulation roller 52, for example, a stainless steel roller having a diameter of 12 mm can be used. The regulation roller 52 makes the fixing liquid 8 on the application roller 50 supplied by the supply roller 51 a uniform thin layer.

  The fixing liquid tank 49 accommodates the application roller 50 while rotatably supporting the application roller 50, and has an opening for pressing the application roller 50 and the transfer fixing roller 42 against the surface facing the transfer fixing roller 42. The application roller 50 is disposed so that a part of the application roller 50 protrudes from the opening toward the outside of the fixer tank 49. Further, in the upper part of the fixing liquid tank 49, a pivot 53 is provided in the longitudinal direction of the fixing liquid tank 49 (in the vicinity of the end opposite to the side where the application roller 50, the supply roller 51 and the regulating roller 52 are integrally arranged) ( 3 in a direction perpendicular to the paper surface of FIG. 3, and is rotatably supported by the main body of the image forming apparatus 1. As a result, the fixing liquid tank 49 is supported so as to be rotatable about the pivot 53. Further, a pressing spring 54 that is supported by the main body of the image forming apparatus 1 and presses the fixing liquid tank 49 is provided at the bottom of the fixing liquid tank 49 on the opposite side to the installation position of the pivot 53. By the action of the pivot 53 and the pressing spring 54, the application roller 50 is pressed against the transfer fixing roller 42 with a predetermined low pressing force. As the pressing spring 54, for example, a coil spring, a leaf spring, a torsion spring, or the like can be used.

  According to the fixing liquid applying unit 43, first, the supply roller 51 rotates in the fixing liquid 8 in the fixing liquid tank 49, thereby causing the fixing liquid 8 to adhere to the surface of the application roller 50. The fixing liquid 8 adhering to the surface of the application roller 50 moves onto the transfer fixing roller 42 at the pressure contact portion between the application roller 50 and the transfer fixing roller 42. At this time, almost half of the fixing liquid 8 on the application roller 50 is transferred to the surface of the transfer fixing roller 42.

  Here, in an image forming apparatus using a heat fixing method in which a toner image is fixed on a recording medium by heating and pressing, melting of the toner is performed only by heating. In the thermal fixing method, toner existing on the heating surface side that is in contact with the heating means is sufficiently melted, but toner existing on the opposite surface is insufficiently melted. On the other hand, the pressing of the toner image is performed from the recording medium side opposite to the heating surface of the toner, and pressurizes the hard-to-melt toner existing on the surface opposite to the heating surface. Adhesive strength may be insufficient.

  In the image forming apparatus 1 according to the present embodiment, the toner which is hardly melted on the surface opposite to the surface heated by the heater 48 provided in the transfer fixing roller 42, that is, adheres to the transfer fixing roller 42 and is transferred and fixed. Since the fixing liquid 8 is applied to the toner that does not come into contact with the surface of the roller 42, the toner that is difficult to melt by heating can be sufficiently softened and / or swelled by the fixing liquid 8. Therefore, when pressure is applied from a pressure roller 45 described later, the adhesion between the recording medium 7 and the toner image can be sufficiently increased, and an image with high fixing strength on the recording medium 7 can be obtained.

  The fixing solution 8 used here is a liquid that softens and / or swells the toner. For example, the fixing solution 8 is a composition containing water and an auxiliary solvent and does not penetrate into the transfer fixing roller 42. A co-solvent is an organic compound that can be dissolved or dispersed in water. Specific examples of the auxiliary solvent include, for example, methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, octyl alcohol, decyl alcohol, diethylene glycol, glycerin, polyethylene glycol, phenols, benzyl alcohol, methylbenzyl alcohol and other alcohols, acetone, Ketones such as methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, ethers such as methyl ethyl ether, diethyl ether, methyl butyl ether, methyl isobutyl ether, dimethyl ether, diisopropyl ether, octyl phenyl ether, methyl acetate, ethyl acetate, Ethyl oleate, ethyl acrylate, methyl methacrylate, dibutyl succinate, diphthalate Chill, diethyl tartrate, ethyl palmitate, and the like esters such as dioctyl phthalate. Among these, ethers and esters are preferable, and esters are most preferable. These auxiliary solvents are excellent in the action of swelling and softening the binder resin of the toner 17. The auxiliary solvent can be used alone or in combination of two or more.

  Although the content of the auxiliary solvent in the fixing solution 8 is not particularly limited, it is preferably 5 to 80% by weight, more preferably 10 to 70% by weight based on the total amount of the fixing solution 8. If it is less than 5% by weight, the action of swelling and softening the binder resin in the toner 17 becomes weak, and there is a possibility that sufficient fixing strength cannot be obtained. On the other hand, if it exceeds 80% by weight, the permeability to the toner image is reduced, and particularly when the amount of toner is large, only the toner on the surface of the toner image swells and softens, so that the toner inside the toner image is fixed to the recording medium. Insufficient toner may be removed.

  For the purpose of improving the wettability of the fixing solution 8 with respect to the toner 17 and improving the dispersibility of the auxiliary solvent in the fixing solution 8, for example, a surfactant or a dispersion aid can be added to the fixing solution 8. Examples of the surfactant include an anionic surfactant such as a higher alcohol sulfate such as lauryl sulfate sodium salt, a higher fatty acid metal salt such as sodium oleate, a fatty acid derivative sulfate, and a phosphate ester. , Quaternary ammonium salts, cationic surfactants such as heterocyclic amines, amino acid esters, zwitterionic surfactants such as amino acids, nonionic surfactants, polyoxyalkylene alkyl ethers, polyoxy An ethylene alkylamine etc. are mentioned. Examples of the dispersion aid include coupling agents such as diethylene glycol, triethylene glycol, polyethylene glycol, monobutyl ether, and diethylene glycol monomethyl ether.

  The fixing solution 8 is a low-viscosity aqueous solution, and quickly penetrates between the particles of the toner 17 and between the transfer-fixing roller 42 and the toner 17. The auxiliary solvent contained in the fixing solution 8 instantaneously swells the toner 17. Soften. Further, since the fixing liquid 8 is applied to the transfer fixing roller 42 heated by the heater 48, the toner image is dried in a short time after being swollen and softened.

  According to the fixing liquid applying means 43, the toner image on the transfer fixing roller 42 is heated to almost the same temperature as the transfer fixing roller 42 by the heater 48, and at the same time, the fixing liquid 8 is contacted and applied by the application roller 50, The toner 17 is swollen and softened. Note that the heating by the heater 48 also has a meaning of correcting the temperature drop of the toner image due to the application of the fixing liquid 8.

  The fixing liquid removing unit 44 is provided upstream of the pressure roller 45 serving as the fixing unit in the rotational direction of the transfer fixing roller 42 serving as the toner image carrier, and the toner image is transferred to the recording medium 7 by the pressure roller 45. Before fixing, the excess fixing liquid adhering to the surface of the transfer fixing roller 42 applied outside the size range of the recording medium 7 is removed.

  FIG. 7 is a side view schematically showing the configuration of the fixing liquid removing unit 44. The fixer removing unit 44 includes a B5 wiping unit 57 that removes excess fixer adhering outside the size range of the B5 sheet on the surface of the transfer fixing roller 42, and surplus adhering outside the size range of the postcard on the surface of the transfer fixing roller 42. The fixing solution wiping means 58 for removing the fixing solution, and the full width wiping means 59 for removing the excess fixing solution generated when the fixing solution 8 adheres longer than the length of the recording medium in the recording medium conveying direction of the transfer fixing roller 42. And a rotary support 60 that supports each of the wiping means 57, 58, 59 so as to be rotatable about its axis.

  Here, the surface area of the transfer fixing roller 42 to which the fixing liquid 8 is applied by the fixing liquid applying unit 43 will be described. FIG. 8 is a plan view showing an application area and a removal area of the fixing liquid 8 on the surface of the transfer and fixing roller 42 when an image is formed on B5 size paper. S <b> 1 is a region where the fixing liquid 8 is applied by the fixing liquid applying unit 43 on the surface of the transfer fixing roller 42. S <b> 2 is a region where the excess fixing solution 8 (surplus fixing solution) is attached to the surface of the transfer fixing roller 42 by the fixing solution applying unit 43. S <b> 3 is an area where the fixing solution 8 is removed by the fixing solution removing unit 44 on the surface of the transfer fixing roller 42.

  In the width direction, the length l from one end e1 to the other end e2 in the application region S1 is equal to the length in the longitudinal direction of the nip portion between the transfer fixing roller 42 and the coating roller 50, and is at least A4. It is set larger than the length in the width direction of the paper. Further, the length of the application area S1 is such that the end e4 located on the outermost side from the one end e3 located on the outermost side of the removal area S2 from which the fixing liquid is removed by the fixing liquid removing means 44. It is set to be smaller than the length L up to. Further, in the recording medium transport direction, the length of the application area S1 is determined according to the size of the recording medium, and is set to be larger than the length of the recording medium in the transport direction (note that the application areas S1 and S2 and the removal area). S3 is appropriately changed according to the size of the recording medium).

  For this reason, the fixing solution 8 adhering to the removal region S2 becomes the excess fixing solution 8 remaining on the transfer fixing roller 42 without being transferred to the recording medium 7. Excess fixer 8 adheres to the surface of the pressure roller 45 due to contact between a transfer fixing roller 42 and a pressure roller 45, which will be described later. When an image is formed on A4 size paper in the next operation, the back surface of the A4 size paper It may cause contamination and wrinkles. Further, the contact between the transfer fixing roller 42 and the intermediate transfer belt 32 may cause the fixing liquid 8 to adhere to the intermediate transfer belt 32 and further to the photosensitive drums 11y, 11m, 11c, and 11b to cause development failure. is there. Therefore, the fixing liquid 8 adhering to the region S <b> 2 becomes an object to be removed by the fixing liquid removing unit 44.

  That is, in the image forming apparatus 1, the toner image and the fixing liquid 8 record the excess fixing liquid 8 applied to the region S2 according to the size of the recording medium detected by a size detection unit (not shown). Fixing liquid removing means 44 is provided for removing before transferring and fixing to the medium 7. The size detection means detects the size of the recording medium 7. The detection result is stored in a CPU (not shown), and the CPU determines the removal region S2 based on the detection result and controls the fixing liquid removing unit 44.

  The recording medium is transported so that the leading end portions in the recording medium transport direction coincide with each other. When the size of the recording medium is detected by the size detecting unit, the recording medium size is detected. In response, it is automatically determined which portion the surplus fixing solution is attached to.

  For example, when the size of the recording medium 7 is B5, the range is a shaded area S2 shown in FIG. 8, and the fixing solution removing unit 7 removes only the excess fixing solution in this portion.

  The B5 wiping means 57 includes a shaft body 57c that is rotatably supported by the rotating plates 60a and 60b of the rotation support body 60, and wiping rollers 57a and 57b that are attached to both ends in the longitudinal direction of the shaft body 57c. Formed with. The wiping rollers 57a and 57b are formed such that the width in the longitudinal direction is a length obtained by subtracting the length of the B5 sheet from the length L of the removal region S3 in the recording medium conveyance direction, and is driven by the rotation of the transfer fixing roller 42. Rotate. Here, it is assumed that the center line in the recording medium conveyance direction of the removal area S3 and the B5 sheet coincides. As the wiping rollers 57a and 57b, the same material as the sponge roller used for the removal member 22y in the fixing liquid cleaner 16y can be used.

  Further, the wiping rollers 57a and 57b are not limited to the same material as the sponge roller, and may be made of a material that does not absorb the fixing liquid 8. In this case, it is desirable that the contact angle of the fixing solution 8 is made of a material smaller than that of the object from which the fixing solution 8 is removed (transfer fixing roller 42 in the present embodiment). The material with a smaller contact angle of the fixing solution 8 improves the wettability of the fixing solution 8 than the material with a larger contact angle, so the fixing solution 8 moves to a material with a smaller contact angle. It is particularly preferable that the difference between the contact angle of the fixing solution with respect to the removing member roller and the contact angle of the fixing solution with respect to the object from which the fixing solution is removed is 10 ° or more.

  For example, when the wiping rollers 57a and 57b are made of polyethylene terephthalate (PET) having a contact angle of 37 ° with the fixing solution 8 and acrylic resin having a contact angle of 32 ° with the fixing solution 8, the surface is made of PFA. A transfer fixing roller 42 having a contact angle of about 60 ° can be preferably used.

  Further, the wiping rollers 57a and 57b may be made of a material that absorbs the fixing liquid 8 (hereinafter referred to as “fixing liquid absorbing material”). Examples of the fixer-absorbing material include paper, cloth, and a porous film. In this case, the transfer fixing roller 42 having a surface coating layer made of a material that does not penetrate the fixing liquid 8 can be suitably used. Here, examples of the material that does not penetrate the fixing solution 8 include PFA. As a result, excess fixing solution 8 on the surface of the transfer fixing roller 42 can be easily removed. Note that not only the transfer fixing roller 42 but also the intermediate transfer belt 32, the pressure roller 45, the photosensitive drums 11y, 11m, 11c, and 11b are made of a material that does not penetrate the fixing liquid 8 at least on their surfaces. Is preferred.

  In the case where a roller made of the above-described liquid-absorbing material is used as the wiping rollers 57a and 57b, it is preferable to provide a heating means for heating the roller inside the roller. By providing such a heating means, it is possible to evaporate and remove the solvent of the fixing liquid 8 absorbed by the roller, so that the fixing liquid removing ability does not deteriorate. The heating temperature by the heating means is preferably 130 ° C. or lower. When the heating temperature exceeds 130 ° C., the solvent vapor of the fixing solution 8 is generated and may adhere to the photosensitive drums 11y, 11m, 11c, 11b, the intermediate transfer belt 32, etc., and may be liquefied and contaminated.

  The wiping rollers 57a and 57b as described above can be used not only for the fixing solution removing means 44 for removing the excess fixing solution of the transfer and fixing roller 42, but also the above-described removing member 22y of the fixing solution cleaner 16y, which will be described later. In this embodiment, the fixing liquid 8 is removed, such as the intermediate transfer medium cleaning means, the fixing liquid removing means for removing the fixing liquid adhering to the fixing means, and the fixing liquid removing means for removing the fixing liquid adhering to the recording medium conveying means. Regardless of the object, it can be used as various removal means.

  When a wiping roller made of a liquid-absorbing material is used as a means for removing the fixing liquid adhering to the photosensitive drums 11y, 11m, 11c, 11b or an intermediate transfer medium included in an image forming apparatus according to an embodiment described later, Since the temperature rise by the means adversely affects the photosensitive drums 11y, 11m, 11c, and 11b, it is preferable not to include a heating means for heating the roller.

  The postcard wiping means 58 includes a shaft body 58c that is pivotally supported by the rotating plates 60a and 60b of the rotary support 60, and wiping rollers 58a and 58b that are attached to both ends in the longitudinal direction of the shaft body 58c. The The wiping rollers 58a and 58b have the same width in the longitudinal direction as that of the wiping means 57 for B5 except that the width in the longitudinal direction is formed by subtracting the length of the postcard from the length L of the removal region S3 in the recording medium conveyance direction. It has the same configuration as the wiping rollers 57a and 57b.

The full-width wiping means 59 includes a shaft body (not shown) that is pivotally supported by the rotating plates 60a and 60b of the rotation support body 60, and a wiping roller 59a that is attached to the entire region in the longitudinal direction of the shaft body.
The wiping roller 59a has the same configuration as the wiping rollers 57a and 57b in the B5 wiping means 57 except that the wiping roller 59a is attached to the entire region in the length direction of the shaft body.

  The rotating support 60 has a rotating plate 60a that pivotally supports the B5 wiping means 57, the postcard wiping means 58, and the full width wiping means 59, and the axis of the rotating plate 60a is aligned with the axis of the rotating plate 60a. A rotating plate 60b is provided so as to protrude outward and connected to a rotation driving means (not shown). The B5 wiping means 57 and the postcard wiping means 58 are pivotally supported so as to face each other via the axis of the rotary plate 60a. The full width wiping means 59 is a postcard wiping means 58 that is perpendicular to a straight line connecting the pivot support position of the B5 wiping means 57 and the pivot support position of the postcard wiping means 58 and the pivot support position of the B5 wiping means 57. Are arranged at the intersections with the circle including the pivot support position and pivotally supported. Here, for example, a pulse motor is used as the rotation driving means.

  For example, when the rotation center 60 is rotated 90 degrees in any direction from the state where the B5 wiping means 59 is in pressure contact with the transfer fixing roller 42, the full width wiping means 59 causes the full width wiping means 59 to transfer the fixing roller. 42 is in pressure contact. When rotated 90 ° in the same direction, the postcard wiping means 58 comes into pressure contact with the transfer fixing roller 42. Further, when 90 ° is further rotated in the same direction, none of the wiping means 57, 58, 59 comes into contact with the transfer fixing roller 42.

  Here, the length in the longitudinal direction of each wiping means 57, 56, 57 is formed longer than the length in the longitudinal direction of the application roller 50 of the fixing liquid applying means 43. In general, the fixer 8 applied by the fixer applying unit 43 is likely to be accumulated at the end portions e1 and e2 of the fixer applying region S1, and the amount of liquid at the end portions e1 and e2 often increases. Further, when the length in the width direction of the fixer removing unit 44 is equal to the length l in the width direction of the fixer application area S1 or shorter than the length l in the width direction of the fixer application area S1, the end e1, It is difficult to completely remove the fixing solution 8 adhering to e2. Therefore, by making the length L, which is the length in the width direction of the region S3 from which the fixing solution 8 is removed, longer than the length of the region S1 to which the fixing solution 8 is applied, the end portion of the fixing solution application region S1. Excess fixing liquid 8 present in e1 and e2 can also be sufficiently removed, and the fixing liquid 8 can be reliably removed from the transfer fixing roller 42.

  Further, the length l of the region S1 to which the fixing liquid 8 is applied by the fixing liquid applying unit 43 in the width direction may be longer than the length in the width direction (longitudinal direction) of the photosensitive drums 11y, 11m, 11c, and 11b. preferable. As described above, although the fixer 8 is easily accumulated at the end of the region S1 to which the fixer 8 is applied and is difficult to remove, the positions of the ends e1 and e2 of the fixer apply region S1 are the positions of the photosensitive drum 11y. , 11m, 11c, and 11b, the excess fixing liquid adhering to the transfer fixing roller 42 is not completely removed, and the residual fixing liquid remaining without being further removed is intermediate transfer belt 32. Even when the photosensitive drums 11y, 11m, 11c, and 11b are reached through the contact, the possibility of adhering to the photosensitive drums 11y, 11m, 11c, and 11b is reduced.

  For example, when the size detected by the size detecting unit is B5, the fixing liquid removing unit 44 is configured such that the B5 wiping unit 57 contacts the transfer fixing roller 42 as shown in FIG. Then, the rotating support 60 is rotated to remove the excess fixing liquid applied outside the size range of B5 in the width direction. When the excess fixing liquid applied outside the B5 size range in the width direction is removed, the rotary support 60 is arranged so that the full width wiping means 59 comes into contact with the transfer fixing roller 42 immediately as shown in FIG. 7B. , And the excess fixing liquid applied outside the B5 size range in the recording medium conveyance direction is removed.

  If the size detected by the size detection means is a postcard, the post support wiping means 58 is rotated so that the postfix wiping means 58 contacts the transfer fixing roller 42 as shown in FIG. Excess fixer applied outside the postcard size range in the direction is removed. When the excess fixing liquid applied outside the size range of the postcard in the width direction is removed, the rotary support 60 is arranged so that the full width wiping means 59 comes into contact with the transfer fixing roller 42 as shown in FIG. Is rotated to remove excess fixer applied outside the size range of the postcard in the recording medium conveyance direction.

  If the size detected by the size detection means is A4, the rotary support 60 rotates so that the wiping means 57, 58, 59 are not in contact with the transfer fixing roller 42. In the case where the excess fixing liquid in the recording medium conveyance direction is significantly longer than the length in the A4 size recording medium conveyance direction, the excess fixing liquid may be removed by the full width wiping means 59. If the excess fixing liquid in the recording medium conveyance direction when using a small-sized recording medium is slightly longer than the length of the recording medium 7 in the conveyance direction, it is not always necessary to remove the excess fixing liquid by the full width wiping means 59. .

  According to the fixing liquid removing unit 44, only the excess fixing liquid applied by the fixing liquid applying unit 43 and attached to the transfer fixing roller 42 is removed before the toner image is fixed on the recording medium 7 by the pressure roller 45 described later. can do. Such a fixing solution removing unit 44 can easily remove only the excess fixing solution applied outside the size range of the recording medium 7 in accordance with the sizes of the plurality of recording media 7. Inside, the wiping means 57, 58, 59 do not come into contact with the transfer fixing roller 42. Therefore, there is no possibility that the toner image carried on the transfer fixing roller 42 is disturbed, and further, by removing the excess fixing liquid adhering to the transfer fixing roller 42 before fixing the toner image on the recording medium 7, The fixing liquid is prevented from adhering to the pressure roller 45. For this reason, when the large recording medium 7 is carried and conveyed by the recording medium conveying means 5 at the next image formation, even if the pressure roller 45 and the recording medium 7 come into contact with each other, the fixing is performed on the back surface of the recording medium 7. It is possible to prevent the liquid from adhering.

  The pressure roller 45 is a fixing unit configured to be in pressure contact with the transfer fixing roller 42 via a recording medium 7 conveyed to a recording medium conveying unit 5 described later and to be rotationally driven in the axial direction. The pressure roller 45 may be one commonly used in this field. However, in this embodiment, the outer diameter is 40 mm, the core metal, and the elastic layer provided on the surface of the core metal is 2 mm in thickness and 50 degrees in hardness. A laminate including a (JIS-A) silicone rubber layer and a PFA layer having a thickness of 20 μm as a surface layer provided on the surface of the silicone rubber layer is used. The pressure roller 45 is disposed so as to be in pressure contact with the transfer fixing roller 42 via the recording medium 7 with a linear pressure of 10 N / cm, for example, and no voltage is applied.

  According to the pressure roller 45, the toner image heated by the heating unit provided in the transfer fixing roller 42 is softened and / or swollen by the fixing liquid applying unit 43 and transferred and fixed to the recording medium 7 by pressing.

  Further, according to the pressure roller 45, the toner image is pressed against the recording medium 7 and strongly enters the paper fiber, and at the same time, the particles of the toner 17 are fused to make the surface of the toner image smooth. As a result, a high-quality color image excellent in color developability and surface gloss due to subtractive color mixing can be obtained.

  The transfer and fixing roller cleaner 46 removes the toner and residual fixing liquid remaining on the transfer and fixing roller 42 after transfer and fixing to the recording medium 7 is performed by the pressure roller 45. The transfer fixing roller cleaner 46 is a member that removes toner and residual fixing liquid remaining on the surface of the transfer fixing roller 42 after the toner image carried on the transfer fixing roller 42 is transferred to the recording medium 7 by the pressure roller 45. A cleaning blade 46a that is provided so as to face the transfer fixing roller 42, is pressed against the transfer fixing roller 42 by a pressure unit (not shown), and scrapes off residual toner, residual fixing liquid, and the like on the transfer fixing roller 42; And a toner storage container 46b for storing toner scraped off by the blade 46a. As the cleaning blade 46a, for example, a blade made of urethane rubber having a thickness of 3 mm can be used.

  The toner image transferred from the intermediate transfer belt 32 and carried on the transfer and fixing roller 42 is heated by the heater 48 in the transfer and fixing roller 42 and is applied with the fixing solution 8 by the fixing solution applying means 43 to be in a swelling and softened state. Become. The excess fixing liquid applied outside the recording medium size by the fixing liquid removing unit 44 and attached to the transfer fixing roller 42 is removed by the fixing liquid removing unit 44, and the toner image to which the fixing liquid 8 is applied is transferred and fixed. By the rotation of the roller 42, it is conveyed to the pressure contact portion between the transfer fixing roller 42 and the pressure roller 45. In synchronization therewith, a recording medium 7 is fed from a recording medium conveying means 5 described later, and the toner image on the transfer and fixing roller 42 is transferred to the surface of the recording medium 7 by pressing from the pressure roller 45 and fixed. .

  The recording medium conveying means 5 includes a recording medium cassette 61 for storing the recording medium 7, a pickup roller 62 for feeding the recording medium 7 one by one to the conveying path P, and a toner image on the transfer fixing roller 42 for transferring and fixing the toner image. A pair of registration rollers 63a and 63b for feeding the recording medium 7 to the pressure contact portion in synchronism with being conveyed to the pressure contact portion between the pressure roller 42 and the pressure roller 45.

  According to the recording medium conveying means 5, the recording medium 7 stored in the recording medium cassette 61 is fed to the conveying path P one by one by the pickup roller 62, and further, the transfer fixing roller by the registration rollers 63a and 63b. It is fed to the pressure contact portion between 42 and the pressure roller 45.

  The discharge unit 6 includes a discharge roller 64. The paper discharge roller 64 is fed to the pressure contact portion between the transfer fixing roller 42 and the pressure roller 45 by the recording medium conveying means 5, and the recording medium 7 on which the toner image is fixed is provided on the outer upper surface of the image forming apparatus 1. A member that is discharged to the discharge tray 65 and includes rollers that are provided so as to be in pressure contact with each other, and each roller is supported so as to be rotatable in the respective axial directions.

  In the image forming apparatus 1, the toner image formed by the toner image forming unit 2 is transferred onto an intermediate transfer belt 32 that is an intermediate transfer medium, and the transferred toner image is a transfer fixing roller 42 that is a toner image carrier. Further transcribe to. The toner image transferred to the transfer fixing roller 42 is heated by a heating unit provided in the transfer fixing roller 42 and applied with the fixing solution 8 in contact with the fixing solution applying unit 43 to be softened and / or swollen. Become. Next, the excess fixing liquid applied outside the size range of the recording medium is removed by the fixing liquid removing unit 44, and then the softened and / or swollen toner image is transferred to the recording medium 7 by the pressure of the pressure roller 45. Fix and form an image.

  According to the image forming apparatus 1, before the toner image is transferred and fixed to the recording medium 7 by the pressure roller 45, only the excess fixing liquid applied outside the size range of the recording medium 7 is removed by the fixing liquid removing unit 44. Therefore, the fixing liquid 8 applied to the portion of the toner image carried on the transfer fixing roller 42 is not removed, and the toner image is not disturbed. Further, by removing the excess fixing liquid adhering to the transfer fixing roller 42 before the transfer and fixing of the toner image to the recording medium 7, the adhesion of the fixing liquid to the pressure roller 45 is prevented, so that the next image formation is performed. Even when a large size recording medium is carried and conveyed by the recording medium conveying means, even if the pressure roller 45 and the recording medium 7 come into contact with each other, adhesion of the fixing liquid 8 to the back surface of the recording medium 7 can be prevented. .

  When the image forming apparatus 1 includes the intermediate transfer belt separating means 37 together with the belt cleaner 36, the excess fixing liquid adhering to the transfer fixing roller 42 is not removed due to a malfunction of the apparatus such as a paper jam, and the photosensitive drum 11y. , 11m, 11c, 11b, the fixing liquid 8 adhered to the photosensitive drums 11y, 11m, 11c, 11b is removed by the fixing liquid cleaners 16y, 16m, 16c, 16b. And the occurrence of image omission can be prevented. At this time, the intermediate transfer belt separating means 37 can separate the photosensitive drums 11y, 11m, 11c, and 11b from the intermediate transfer belt 32 so that they are not in contact with each other. The adhering fixer 8 does not adhere to the photosensitive drums 11y, 11m, 11c, and 11b, and the photosensitive drums 11y, 11m, 11c, and 11b can be more reliably cleaned. Furthermore, since the fixing liquid 8 adhering to the intermediate transfer belt 32 can be removed by the belt cleaner 36, the fixing liquid 8 adhering to the photosensitive drums 11y, 11m, 11c, and 11b can be more reliably removed.

  Such an image forming apparatus 1 is not limited to the above configuration, and various modifications can be made.

  In the image forming apparatus 1 of the present embodiment, the fixing solution 8 that softens and / or swells the toner is used. However, the fixing solution 8 is not limited to this, and a known one can be used, for example, chloroprene in the fixing solution. Uniformly disperse in water, synthetic adhesive polymers such as rubber adhesives, vinyl acetate, EVA (ethylene vinyl acetate copolymer), acrylic resin, etc., mainly composed of polymer elastomers such as rubber, nitrile rubber, styrene-butadiene rubber It is also possible to contain a component having a known adhesive action such as an emulsion adhesive. According to such a fixing liquid, not only the softening and / or swelling of the toner but also the adhesive force between the toner 17 and the recording medium 7 can be increased by the adhesive, and the adhesive force between the toner 17 and the recording medium 7 can be increased. Can be further improved. As a result, the fixing strength of the toner image on the recording medium 7 can be increased.

  In each of the above-described embodiments, a tandem color image forming apparatus is used. However, the tandem type color image forming apparatus is used for a so-called four-rotation color image forming apparatus that superimposes one color image every rotation of the intermediate transfer belt 32. Also good. Further, the present invention is not limited to a color image forming apparatus, and may be used for a monochromatic image forming apparatus using a monochromatic image forming unit.

  The image forming apparatus 1 according to the present embodiment can be specifically embodied as, for example, a copying machine, a printer, a facsimile machine, or a multifunction machine having these functions.

  9A and 9B are diagrams schematically showing a configuration of a main part of the image forming apparatus 71 according to the second embodiment of the present invention. The image forming apparatus 71 is similar to the image forming apparatus 1, and corresponding parts are not shown and described. Further, in the configuration shown in FIG. 9, portions corresponding to the image forming apparatus 1 are denoted by the same reference numerals and description thereof is omitted.

  The image forming apparatus 71 is a recording medium transport direction by the recording medium transport unit 5 as a fixing liquid removing unit that removes excess fixing liquid 8 applied outside the size range of the recording medium 7 detected by a size detection unit (not shown). For each recording medium having a different length in the width direction, which is a direction orthogonal to the recording medium, the excess fixing liquid applied outside the size range of the recording medium corresponding to the size of each recording medium is wiped off. A fixing liquid removing unit 72 including wiping units 73, 74, 75, 76, and 77 set to a length that can be taken is provided.

  The fixer removing unit 72 is provided upstream of the pressure roller 45 in the rotation direction of the transfer fixing roller 42 in the same manner as the fixer removing unit 44 provided in the image forming apparatus 1 of the first embodiment. Before the toner image is transferred and fixed on the recording medium 7 by the pressure roller 45, the excess fixing liquid on the surface of the transfer fixing roller 42 applied outside the size range of the recording medium 7 is removed. The fixing liquid removing unit 71 is variably provided with a length in the width direction that is a direction orthogonal to the recording medium conveyance direction by the recording medium conveyance unit 5, and corresponds to the size of each recording medium for each different recording medium. And wiping means 73, 74, 75, 76, 77 set to a length capable of wiping off the excess fixing liquid applied outside the size range of the recording medium.

  The fixer removing means 72 is a B5 wiping means 73 and 74 for removing excess fixer applied outside the size range of B5 paper, and a postcard wiping for removing excess fixer applied outside the postcard size range. Means 75 and 76, and a central portion wiping means 77 for removing the excess fixing liquid generated when the fixing liquid is applied longer than the length of the recording medium in the recording medium conveyance direction.

  The B5 wiping means 73 and 74 are formed in a portion excluding the length in the width direction of the B5 paper from the length in the width direction of the region S1 to which the fixing liquid is applied, and are in contact with the transfer fixing roller 42. Wiping rollers 73a and 74a supported so as to rotate following the rotation of the transfer and fixing roller 42, and position adjusting means 73b and 74b that allow the wiping rollers 73a and 74a to be separated from the transfer fixing roller 42, respectively. Consists of including. As the wiping rollers 73a and 74a, the same roller as the removing member roller provided in the fixing liquid removing unit 44 of the first embodiment described above can be used.

  Since the position adjusting means 73b and 74b are similar in configuration to the position adjusting means 24y of the fixing liquid cleaner 16y of the first embodiment described above, description thereof is omitted. The rotation shaft, base, and transfer fixing roller 42 (not shown) included in the position adjusting units 73b and 74b are preferably supported by the same member so that their relative positions are constant.

  The postcard wiping means 75 and 76 include wiping rollers 75a and 76a formed on a portion excluding the length in the width direction of the postcard from the length in the width direction of the region S1 to which the fixing liquid is applied, and the wiping rollers 75a and 75a. Position adjusting means 75b and 76b that enable the separation of 76a from the transfer and fixing roller 42 are included. Further, the central wiping unit 77 includes a wiping roller 77a formed in a length in the width direction of the postcard, and a position adjusting unit 77b that allows the wiping roller 77a to be separated from the transfer fixing roller 42. As the wiping rollers 75a, 76a, 77a and the position adjusting means 75b, 76b, 77b, the same ones as the wiping rollers 73a, 74a and the position adjusting means 73b, 74b described above can be used.

  For example, when such a fixing liquid removing unit 71 detects that the size of the recording medium 7 is B5 by the size detecting unit, as shown in FIG. 9A, the wiping roller 73a is moved by the position adjusting units 73b and 74b. , 74a are brought into contact with the transfer fixing roller 42, and the wiping rollers 75a, 76a, 77a are separated from the transfer fixing roller 42 by the position adjusting means 75b, 76b, 77b, and are applied outside the B5 size range in the width direction. Remove excess fixer. When the excess fixing liquid applied outside the B5 size range in the width direction is removed, the wiping rollers 75a, 76a, 77a are immediately moved by the position adjusting means 75b, 76b, 77b as shown in FIG. 9A (b). Along with the wiping rollers 73a and 74a, the transfer fixing roller 42 is brought into contact with the wiping rollers 73a and 74a to remove excess fixing liquid in the recording medium conveyance direction.

  When the size detecting means detects that the size of the recording medium 7 is a postcard, as shown in FIG. 9B (c), the wiping rollers 73a, 74a, 75a, 76a are moved by the position adjusting means 73b, 74b, 75b, 76b. Is brought into contact with the transfer fixing roller 42, and the wiping roller 77a is separated from the transfer fixing roller 42 by the position adjusting means 77b to remove the excess fixing liquid applied outside the postcard size range in the width direction. When the excess fixing liquid applied outside the size range of the postcard in the width direction is removed, the wiping roller 77a is immediately brought into contact with the transfer fixing roller 42 by the position adjusting means 77b as shown in FIG. 9A (b). Excess fixer in the recording medium conveyance direction is removed.

  Further, when the size detecting means detects that the size of the recording medium 7 is A4, the wiping rollers 73a, 74a, 75a, 76a, 77a are transferred to the transfer fixing roller 42 by the position adjusting means 73b, 74b, 75b, 76b, 77b. It is adjusted not to come into contact with. When the excess fixing liquid in the recording medium conveyance direction is significantly longer than the length in the A4 size recording medium conveyance direction, the excess fixing liquid in the recording medium conveyance direction is removed as shown in FIG. 9A (b). May be.

  Also with such a fixing liquid removing means 72, the length in the width direction is changed in accordance with the sizes of the plurality of recording media 7, and when the fixing liquid 8 is removed, the wiping rollers 73a and 73a are within the size range of the recording medium 50. Only the excess fixing liquid applied outside the size range of the recording medium 7 can be easily removed without contact between the transfer fixing roller 42 and 74a, 75a, 76a, 77a.

  The fixing liquid removing unit 71 is not limited to the above configuration, and various modifications can be made. For example, the wiping rollers 73 a, 74 a, 75 a, 76 a, and 77 a do not necessarily need to rotate following the rotation of the transfer fixing roller 42. Further, the wiping means 73, 74, 75, 76, 77 are not limited to the configuration including the wiping roller, and may include, for example, a removing member such as a blade.

  FIG. 10 is a diagram schematically showing a configuration of a main part of an image forming apparatus 81 according to the third embodiment of the present invention. The image forming apparatus 81 is similar to the image forming apparatus 1, and corresponding parts are not shown and described. Also, in the configuration shown in FIG. 10, portions corresponding to the image forming apparatus 1 are denoted by the same reference numerals and description thereof is omitted.

  The image forming apparatus 81 serves as a fixing solution removing unit that removes excess fixing solution 8 applied outside the size range of the recording medium 7 detected by a size detecting unit (not shown). It has the means 82, It is characterized by the above-mentioned.

  The suction removing unit 82 includes a suction nozzle 83 having a suction port for sucking in excess fixing liquid, a suction fan 84 that generates suction force to the suction nozzle 83, and a hose 85 that connects the suction nozzle 83 and the suction fan 84. Consists of. The suction nozzle 83 is preferably formed such that the length of the suction port in the longitudinal direction is larger than the length of the transfer fixing roller 42 in the longitudinal direction.

  In such suction removing means 82, air is sucked from the suction port of the suction nozzle 83 via the hose 85 by the suction fan 84, the sucked air hits the excess fixing solution, and the excess fixing solution is transferred to the transfer fixing roller 42. The excess fixing liquid floating from the surface and floating together with the sucked air is sucked from the suction port, so that the excess fixing liquid can be removed from the transfer fixing roller 42.

  According to the suction removing means 82, since the excess fixing liquid is removed by suction, the fixing liquid is not scattered. Therefore, it is possible to prevent the fixing liquid from scattering into the image forming apparatus, and it is not necessary to provide a member such as a scattering prevention cover.

  The toner image to which the fixing liquid 8 is applied by the fixing liquid applying unit 43 softens the binder resin, wax, etc. contained in the toner at that time, and the adhesion force between the toner image and the transfer fixing roller 42 and the toner image and toner. Since the adhesive force with the fixing liquid 8 applied to the image is high, there is little possibility that the suction removal means 82 sucks the toner image and the fixing liquid 8 applied to the toner image. Such a toner image is preferably heated to a temperature higher than the glass transition point of the toner 17 before the fixing liquid 8 is applied by the fixing liquid applying unit 43. By heating the toner image in this manner, the adhesion between the toner image and the transfer fixing roller 42 and the adhesion between the toner image and the fixing liquid 8 applied to the toner image can be further improved. Even if the excess fixing liquid is sucked by the removing means 82, the toner image and the fixing liquid 8 applied to the toner image are not sucked, so that the risk of the toner image being disturbed can be further reduced.

  FIG. 11 is a cross-sectional view schematically showing a configuration of an image forming apparatus 91 according to a fourth embodiment of the present invention, and FIG. 12 is a main part of the image forming apparatus 91 shown in FIG. It is sectional drawing which expands and shows the structure of (). The image forming apparatus 91 of the present embodiment is similar to the image forming apparatus 1 of the first embodiment described above, and corresponding portions are denoted by the same reference numerals and description thereof is omitted.

  The image forming apparatus 91 includes a toner image forming unit 2, an intermediate transfer unit 92, a transfer fixing unit 93, a recording medium transport unit 5, and a discharge unit 6.

  The intermediate transfer unit 92 includes an intermediate transfer belt 32 that is an intermediate transfer medium, intermediate transfer rollers 33y, 33m, 33c, and 33b, a drive roller 94, a tension roller 35, and a belt cleaner 36.

  The driving roller 94 is provided in pressure contact with the transfer fixing roller 42 and capable of being driven to rotate about an axis by a driving unit (not shown). As the driving roller 94, the same one as the driving roller 34 of the first embodiment described above can be used. In this embodiment, the driving roller 94 includes a position adjusting unit 95 that can be separated from the transfer fixing roller 42.

  The position adjustment means 95 is configured in the same manner as the position adjustment means 24y included in the fixing liquid cleaner 16y of the first embodiment described above except that it supports the driving roller 94 instead of the removal member 22y. Description is omitted. The position adjusting means 95 is preferably supported by the same member so that the relative positions of the rotation shaft, base, and transfer fixing roller 42 not shown are not changed.

  In addition, the intermediate transfer belt 32 is provided with an intermediate transfer belt cleaner 96 in case a fixing liquid adheres to the intermediate transfer belt 32. The intermediate transfer belt cleaner 96 is configured in the same manner as the fixing solution cleaner 16y of the first embodiment described above.

  During normal image formation, the drive roller 94 is disposed so as to be in pressure contact with the transfer fixing roller 42. The intermediate transfer belt cleaner 96 is disposed so as to be separated from the intermediate transfer belt 32. Here, for example, when an image having a predetermined number of prints is formed, the cleaning mode is activated. When the cleaning mode is activated, the drive roller 94 is moved away from the transfer fixing roller 42 by the position adjusting means 95, and the intermediate transfer belt cleaner 96 is brought into contact with the intermediate transfer belt 32 to perform the cleaning operation. When the cleaning operation of the intermediate transfer belt 32 is completed, the position adjustment is performed so that the driving roller 94 and the transfer fixing roller 42 come into pressure contact again, and the intermediate transfer belt cleaner 96 and the intermediate transfer belt 32 are separated from each other. Is called.

  According to the position adjusting means 95 and the intermediate transfer belt cleaner 96, the fixing liquid adhering to the intermediate transfer belt 32 can be removed without the intermediate transfer belt 32 coming into contact with the transfer fixing roller. Further, when the image is formed, the intermediate transfer belt cleaner 96 and the intermediate transfer belt 32 are disposed so as to be separated from each other. Therefore, the intermediate transfer belt 32 is worn or scratched by pressure contact between the intermediate transfer belt cleaner 96 and the intermediate transfer belt 32. Can be prevented.

  According to the intermediate transfer unit 92, similar to the intermediate transfer unit 3 of the first embodiment, the toner images of the respective colors formed on the photosensitive drums 11y, 11m, 11c, and 11b are converted into toner images on the intermediate transfer belt 32. The toner image on the intermediate transfer belt 32 is transferred to the transfer fixing roller 42 by superimposing and transferring the toner image on the transfer surface 83a. After the toner image is transferred to the transfer fixing roller 42, the toner remaining on the intermediate transfer belt 32 is removed by the belt cleaner 87.

  The transfer fixing means 93 includes a transfer fixing roller 42 as a toner image carrier, a fixing liquid applying means 43, a pressure roller 45 as a fixing means, a transfer fixing roller cleaner 46 as a fixing liquid removing means, and a pressure. The pressure roller cleaner 97 is another fixing solution removing unit that removes the fixing solution adhering to the roller 45.

  In the present exemplary embodiment, the fixing liquid removing unit 44 provided in the image forming apparatus 1 according to the first exemplary embodiment is not provided, and the recording medium conveyance unit serving as a recording medium conveyance unit is provided rather than the pressure roller 45 serving as the fixing unit. An excess fixing liquid provided on the downstream side of the recording medium conveyance direction of the means 5 and applied to the recording medium 7 after the toner image is fixed to the recording medium 7 by the pressure roller 45, A transfer fixing roller cleaner 46 including a cleaning blade 46a, which is a blade-shaped removing member that scrapes and removes the fixing solution, is provided as a fixing solution removing unit that removes residual fixing solution adhering to the medium conveying unit.

  The pressure roller cleaner 97 is another fixing liquid removing unit that removes the fixing liquid 8 attached to the pressure roller 45, and a web 98 that is a strip-shaped removing member that adsorbs and removes the fixing liquid. A position adjusting unit 99 that adjusts the web 98 and the pressure roller 45 to a press-contact state or a separated state, and two rotating rollers 100 and 101 that are rotatably provided so as to face each other with the position adjusting unit 99 interposed therebetween. Composed.

  FIG. 13 is a view showing a pressure roller cleaner 97 in which the web 98 and the pressure roller 45 are in pressure contact, and FIG. 14 shows the pressure roller cleaner 97 in which the web 98 and the pressure roller 45 are separated from each other. FIG.

  As the web 98, a nonwoven fabric made of rayon, polyester, acrylic fiber, or the like can be used. The web 98 is not limited to these, and various materials can be used. However, as with the removing member roller included in the fixing solution removing unit 44 of the first embodiment, the fixing is performed. An object whose contact angle of the liquid 8 is smaller than the contact angle of the fixing liquid 8 with respect to the pressure roller 45 or an object made of a liquid-absorbing material is particularly preferable. The web 98 is stretched between support rollers 102 (described later) included in the position adjusting means 99 and the rotation rollers 100 and 101.

  The position adjusting means 99 has the same structure as the position adjusting means 24y of the fixing liquid cleaner 16y included in the image forming apparatus 1 according to the first embodiment, and the same reference numerals (however, the colors are used for corresponding portions). The symbols y, m, c, and b are omitted), and the description is omitted. The position adjusting means 99 has a support roller 102 instead of the removing member 22y in the position adjusting means 24y.

  The rotary roller 100 is provided so that its axis is parallel to the axis of the support roller 102, and is rotatably supported by a bearing (not shown). The rotating roller 100 is preferably supported by the same members as the rotating shaft 30, the base 28 and the pressure roller 45 included in the position adjusting means 99.

  The rotary roller 101 is provided so that its axis is parallel to the axis of the support roller 102, and is rotatably supported by the rotary roller support 103. The rotating roller support 103 has a bearing that rotatably supports the rotating roller 101 by fitting the shaft center (bearing) of the rotating roller 101 at one end in the longitudinal direction, and a pair of plates to which the pressing spring 105 is fixed at the other end. A support plate 104, which is a member, a pressure spring 105 having one end fixed to the end of the support plate 104 and the other end fixed to the base 106, and a support member (not shown) inside the image forming apparatus 91, And a base 106 that supports the pressing spring 105. As the pressing spring 105 expands and contracts, the support plate 104, and thus the rotating roller 101, moves toward or away from the pressure roller 45. With such a configuration, the state of the pressure spring 105 included in the rotating roller support 103 changes between the compressed state and the natural state due to the movement of the web 98, so that a constant tension can always be applied to the web 98.

  The pressure roller cleaner 97 that removes the fixing liquid adhering to the pressure roller 45 performs a cleaning operation only when the fixing liquid adheres to the pressure roller 45. The case where the fixing liquid adheres to the pressure roller 45 is, for example, when an image is formed on the recording medium 7 having a small size or after it is formed. When the residual fixing liquid adheres to the pressure roller 45, the pressure roller cleaner 97 moves the support roller 102 toward the pressure roller 45 by the position adjusting means 99 as shown in FIG. Then, the web 98 stretched around the support roller 102 is brought into pressure contact with the pressure roller 45, and the fixing liquid adhering to the pressure roller 45 is wiped away. At this time, the pressure spring 105 included in the rotating roller support 103 is compressed as the web 98 moves to the pressure roller 45 side.

  When the fixing liquid does not adhere to the pressure roller 45, for example, when an image is formed on the large size recording medium 7, the pressure roller cleaner 97 is supported by the position adjusting means 99 as shown in FIG. The roller 102 is separated from the pressure roller 45, and the web 98 stretched between the rotating rollers 100 and 101 and the support roller 102 is separated from the pressure roller 45. At this time, the pressure spring 105 included in the rotating roller support 103 returns to the natural state when the web 98 moves to the side opposite to the pressure roller 45.

  The pressure roller cleaner 97 performs a cleaning operation only when the fixing liquid adheres to the pressure roller 45, and the pressure roller 45 is not cleaned when the fixing liquid does not adhere to the pressure roller 45. It is possible to reduce the occurrence of wear and scratches on the pressure roller 45 due to the pressure contact between the pressure roller cleaner 45 and the pressure roller cleaner 97.

  In the image forming apparatus 91, the toner image formed by the toner image forming unit 2 is transferred onto the intermediate transfer belt 32 that is an intermediate transfer medium, and the transferred toner image is a transfer fixing roller 42 that is a toner image carrier. Further transcribe to. The toner image transferred to the transfer fixing roller 42 is heated by a heater 48 provided in the transfer fixing roller 42 and applied with the fixing solution 8 in contact with the fixing solution applying means 43 to be softened and / or swollen. It becomes. This toner image is fixed to the recording medium 7 supplied by the recording medium conveying means 5 by the pressure of the pressure roller 45. After the toner image is transferred and fixed to the recording medium 7, the toner and residual fixing liquid remaining on the surface of the transfer fixing roller 42 are removed by the transfer fixing roller cleaner 46, and if the recording medium 7 has a small size, pressurization is performed. The fixing liquid adhering to the pressure roller 45 is removed by the roller cleaner 97. When the fixing liquid adheres to the intermediate transfer belt 32, the fixing liquid is removed by separating the intermediate transfer belt 32 and the transfer fixing roller 42 by the position adjusting means 95 and the intermediate transfer belt cleaner 96.

  According to the image forming apparatus 91, after the toner image is transferred and fixed on the recording medium 7 by the pressure roller 45, the residual fixing liquid on the surface of the transfer fixing roller 42 can be removed by the transfer fixing roller cleaner 46. Since the fixing liquid applied to the toner image on the fixing roller 42 is not removed, the toner image is not disturbed.

  Further, when the recording medium 7 having a small size is used, even if the fixing liquid adheres to the pressure roller 45 due to the contact between the pressure roller 45 and the transfer fixing roller 42, it adheres to the pressure roller 45 by the pressure roller cleaner 97. Since the fixing solution thus removed can be removed, adhesion of the fixing solution to the back surface of the recording medium 7 due to contact between the pressure roller 45 and the recording medium 7 can be prevented.

  FIG. 15 is a cross-sectional view schematically showing a configuration of an image forming apparatus 111 according to the fifth embodiment of the present invention. The image forming apparatus 111 of the present embodiment is similar to the image forming apparatus 1 of the first embodiment described above, and corresponding portions are denoted by the same reference numerals and description thereof is omitted.

  The image forming apparatus 111 includes a toner image forming unit 2, an intermediate transfer unit 112, a secondary transfer roller 113, a recording medium conveying unit 114, a fixing liquid applying unit 115, a fixing liquid removing unit 116, and a fixing unit. A pressure roller 117, a recording medium supply unit 118, and a discharge unit 119 are included.

  The intermediate transfer unit 112 includes an intermediate transfer belt 120, intermediate transfer rollers 33y, 33m, 33c, and 33b, a driving roller 34, support rollers 121 and 122, and a belt cleaner 36.

  The intermediate transfer belt 120 is an endless belt that is stretched between the driving roller 34 and the support rollers 121 and 122 to form a loop-shaped movement path, and is substantially the same as the photosensitive drums 11y, 11m, 11c, and 11b. It is an intermediate transfer medium that rotates in the direction of the arrow 120b at a speed. The surface of the intermediate transfer belt 120 on which the toner image is transferred becomes the toner image transfer surface 120a. As the intermediate transfer belt 120, the same belt as the intermediate transfer belt 32 of the first embodiment described above can be used.

  The toner image transfer surface 120a of the intermediate transfer belt 120 is in pressure contact with the photosensitive drums 11y, 11m, 11c, and 11b in this order. The positions where the intermediate transfer belt 120 is in pressure contact with the photosensitive drums 11y, 11m, 11c, and 11b are the intermediate transfer positions of the toner images of the respective hues. Intermediate transfer rollers 33y, 33m, 33c, and 33b are disposed at positions that face the photosensitive drums 11y, 11m, 11c, and 11b with the intermediate transfer belt 120 interposed therebetween.

  The two support rollers 121 and 122 are rotatably provided following the movement of the intermediate transfer belt 120 that moves in the direction of the arrow 120 b by the rotation of the driving roller 34. Of the two support rollers 121 and 122, the support roller 122 is provided to face a secondary transfer roller 113 described later. As the support rollers 121 and 122, the same rollers as the tension roller 35 of the first embodiment described above can be used.

  The intermediate transfer unit 112 transfers the toner images of the respective colors formed on the photosensitive drums 11y, 11m, 11c, and 11b while superimposing them on predetermined positions on the toner image transfer surface 120a of the intermediate transfer belt 120, and transfers the toner images. Form. After this toner image is transferred to the recording medium 7 by a secondary transfer roller 113 described later, residual toner, offset toner, paper dust and the like on the toner image transfer surface 120a are removed by the belt cleaner 36, and the toner image transfer surface. The toner image is transferred again to 120a.

  The secondary transfer roller 113 is provided in pressure contact with the support roller 122 via the intermediate transfer belt 120 and rotatably driven in the axial direction. When the toner image on the intermediate transfer belt 120 is transferred to the recording medium 7, a voltage having a polarity opposite to that of the toner is applied to the core of the secondary transfer roller 113.

  In synchronization with the transfer of the intermediate transfer belt 120 onto which the toner image is transferred to the pressure contact portion between the secondary transfer roller 113 and the support roller 122, the recording medium 7 is fed from a recording medium supply unit 118 described later, The toner image on the intermediate transfer belt 120 is transferred to the surface of the recording medium 7 by pressing and applying a voltage. The recording medium 7 to which the toner image has been transferred is carried and conveyed by the recording medium conveying means 114.

  The recording medium conveyance unit 114 includes a conveyance belt 123, a driving roller 124, and a tension roller 125.

  The conveyance belt 123 is an endless belt that is stretched between the driving roller 124 and the tension roller 125 to form a loop-shaped conveyance path. For example, a polytetrafluoroethylene (PTFE) is applied to the transport belt 123 on a recording medium carrying surface 123a, which is a surface on the side carrying at least the recording medium of a polyimide film having a thickness of 100 μm to which conductivity is added by adding a conductive agent. And a coating layer having a thickness of 10 μm can be used.

  The driving roller 124 is provided so as to be rotatable around an axis line by a driving means (not shown). As the driving roller 124, for example, a hollow roller made of a metal such as aluminum can be used. In addition, a heater 126 such as a halogen lamp is provided inside the hollow roller of the driving roller 124. The operation of the heater 126 is controlled by the temperature sensor 127, and the toner image transferred and carried on the recording medium 7 is heated to a temperature higher than the glass transition point of the toner 17, thereby increasing the binding force between the toners.

  The tension roller 125 applies a predetermined tension to the conveyor belt 123 so that the conveyor belt 123 does not loosen. The tension roller 125 includes, for example, a metal shaft body and a coating layer formed on the surface of the metal shaft body. Further, the tension roller 125 may be composed only of a metal shaft. For example, stainless steel is used as the material of the metal shaft body, and fluorine rubber is used as the material of the coating layer, for example.

  The recording medium conveying unit 114 conveys the recording medium 7 on which the toner image is transferred by the secondary transfer roller 113 toward the pressure roller 117 serving as a fixing unit described later in the direction of the arrow 123b. The toner image carried on the recording medium 7 conveyed to the recording medium conveying unit 114 is applied with a fixing liquid by the fixing liquid applying unit 115 before being conveyed to the pressure roller 117 side. That is, in this embodiment, the recording medium 7 is a toner image carrier. The surface on the side where the recording medium 7 carries the toner image is called a toner image carrying surface 7a.

  The fixing liquid applying unit 115 includes a nozzle array in which the width direction, which is a direction perpendicular to the recording medium conveyance direction, is greater than or equal to the width direction of the image forming area of the large size recording medium. A fixer 8 is applied to the support surface 7a.

  The nozzle array included in the fixing liquid applying unit 115 is an apparatus in which a plurality of micro nozzles that cause micro droplets of the fixing liquid 8 to fly toward the toner image carrying surface 7a of the recording medium 7 in accordance with an electrical control signal. is there. As the nozzle array, for example, an ink jet method such as a piezo element (piezoelectric element) can be used. The amount of the fixing liquid applied is adjusted by appropriately adjusting the voltage applied to the piezo element, for example, the toner image carrying surface 7a. And the nozzle array can be adjusted according to the distance.

  When the fixing liquid application unit 115 including such a nozzle array is used, it is easy to adjust the application of the fixing liquid according to the size of the recording medium 7 detected by the size detection unit at least in the recording medium conveyance direction. Therefore, even if a small-sized recording medium is used, no excess fixing liquid is generated in the recording medium conveyance direction.

  Further, in the image forming apparatus 111 according to the present exemplary embodiment, the excess fixing liquid in the width direction applied by the fixing liquid applying unit 115 is supplied to the toner image and the fixing according to the size of the recording medium detected by the size detecting unit. Fixing liquid removing means 116 for removing the liquid before it is fixed on the recording medium is provided.

  FIG. 16 is a diagram illustrating a configuration of the fixing solution removing unit 116 of the image forming apparatus 111 shown in FIG. The fixing liquid removing unit 116 is provided on the upstream side in the recording medium conveying direction 123b of the recording medium conveying unit 114 with respect to the pressure roller 117 which is a fixing unit described later, and the toner image is fixed to the recording medium 7 by the pressure roller 117. Before the recording medium 7 is applied, it is a fixing liquid that adheres to the conveying belt 123 of the recording medium conveying means 114 that is applied outside the size range of the recording medium 7, and is an excess fixing liquid 8 that is applied outside the size range of the recording medium 7. Remove. Further, the fixing liquid removing unit 116 corresponds to a predetermined size of the recording medium 7 and a plurality of wiping units provided to wipe off and remove the excess fixing liquid 8 applied outside the size range of the recording medium 7. Means 128 and 129 are included.

  The fixer removing unit 116 removes the excess fixer 128 applied outside the B5 paper size range, and the postcard wiping unit 129 removes the excess fixer applied outside the postcard size range. And a rotation support 130 that supports each wiping means 128 and 129 so as to be rotatable about its axis.

  The B5 wiping means 128 and the postcard wiping means 129 have the same configuration as the B5 wiping means 57 and the postcard wiping means 58 included in the fixing solution removing means 44 of the first embodiment described above. The B5 wiping means 128 includes a shaft body 128c that is rotatably supported by the rotating plates 130a and 130b of the rotation support 130, and wiping rollers 128a and 128b that are attached to both ends of the shaft body 128c in the longitudinal direction. Formed with. The postcard wiping means 129 includes a shaft body 129c that is rotatably supported by the rotating plates 130a and 130b of the rotary support 130, and wiping rollers 129a and 129b that are attached to both ends in the longitudinal direction of the shaft body 129c. Formed with.

  The wiping means 128 and 129 are connected to a rotation support 130 which is connected to a rotation driving means such as a pulse motor (not shown), and a wiping means for B5 128 and a wiping means for postcard 129 via an axis of the rotary plate 130a. It is supported so as to face each other.

  When the size detecting means detects that the size of the paper 134 is B5, as shown in FIG. 16A, the rotating shaft 133 is rotated so that the B5 wiping means 128 is in contact with the transport belt 123. Excess fixer applied outside the size range is removed. When the size detecting unit detects that the size of the sheet 135 is a postcard size, the rotating shaft 133 is rotated so that the postcard wiping unit 129 contacts the conveying belt 123 as shown in FIG. The excess fixing solution applied outside the postcard size range is removed.

  According to the fixing liquid removing unit 116, only the excessive fixing liquid applied outside the size range of the recording medium 7 can be easily removed before the toner image is fixed to the recording medium 7 by a pressure roller 117 described later. In the size range of the recording medium 7, the wiping means 128 and 129 do not come into contact with the recording medium carrying the toner image, so that the toner image is not disturbed. Furthermore, since the excess fixing liquid adhering to the conveyance belt 123 can be removed before the toner image is fixed to the recording medium 7, the fixing liquid is prevented from adhering to the pressure roller 117.

  The pressure roller 117 is configured to be in pressure contact with the tension roller 125 via the recording medium 7 conveyed to the recording medium supply unit 114 and to be rotatable in the axial direction. As the pressure roller 117, the same one as the pressure roller 45 of the first embodiment can be used.

  The toner image transferred from the intermediate transfer belt 120 and carried on the recording medium 7 is heated by the heater 126 in the driving roller 124 included in the recording medium carrying means 114 that carries and carries the recording medium 7, and fixing liquid application means. The fixing solution 8 is applied by 115, and a swelling and softening state is obtained. The toner image on the recording medium 7 to which the fixing liquid 8 is applied after the excess fixing liquid applied to the conveying belt 123 is removed by the fixing liquid removing unit 116 and removed from the recording medium size range is tensioned. It is conveyed to a pressure contact portion between the roller 125 and the pressure roller 117 and is fixed on the surface of the recording medium 7 by pressure from the pressure roller 117.

  The recording medium supply unit 118 includes a recording medium cassette 61 that stores the recording medium 7, a pickup roller 62 that feeds the recording medium 7 to the conveyance path P one by one, and a toner image on the intermediate transfer belt 32 that supports the support roller 124. And a pair of registration rollers 131a and 131b for feeding the recording medium 7 to the pressure contact portion in synchronism with the conveyance to the pressure contact portion between the second transfer roller 113 and the secondary transfer roller 113.

  The discharge unit 119 includes a discharge roller 132. The paper discharge roller 132 is fed to the pressure contact portion between the pressure roller 117 and the tension roller 125 by the recording medium conveying means 114, and the recording medium 7 on which the toner image is fixed is provided on the external side surface of the image forming apparatus 1. It is a member that is discharged to the paper tray 133 and includes rollers that are provided so as to be in pressure contact with each other, and each roller is supported so as to be able to be driven to rotate in the respective axial direction.

  According to the image forming apparatus 111, only the excess fixing liquid outside the size range applied by the fixing liquid applying unit 115 and attached to the recording medium conveying unit 114 before the toner image is fixed to the recording medium 7 by the pressure roller 117. Can be removed by the fixer removing means 116. Accordingly, since the fixing liquid applied to the toner image portion carried on the recording medium 7 is not removed, the toner image is not disturbed. Further, by removing the excess fixing liquid adhering to the recording medium conveying means 114 before fixing the toner image on the recording medium 7, it is possible to prevent the excessive fixing liquid from adhering to the pressure roller 117. Even when the large recording medium 7 and the pressure roller 117 come into contact with each other during image formation, the fixing liquid does not adhere to the back surface of the recording medium 7.

  FIG. 17 is a cross-sectional view schematically showing a configuration of an image forming apparatus 141 according to the sixth embodiment of the present invention. The image forming apparatus 141 of the present embodiment is similar to the image forming apparatus 111 of the fifth embodiment described above, and corresponding portions are denoted by the same reference numerals and description thereof is omitted.

  The image forming apparatus 141 includes a toner image forming unit 2, an intermediate transfer unit 142 including an intermediate transfer belt 146 that is a toner image carrier, a transfer fixing unit 143 that is a fixing unit, a recording medium conveying and feeding unit 144, and a discharge unit. And means 145.

  The intermediate transfer unit 142 includes an intermediate transfer belt 146 that is a toner image carrier, intermediate transfer rollers 33y, 33m, 33c, and 33b, a driving roller 147, support rollers 148 and 149, a fixing liquid applying unit 150, and a fixing unit. An intermediate transfer belt cleaner 151 as a liquid removing unit and a belt cleaner 36 are included.

  The intermediate transfer belt 146 is an endless belt that is stretched between the drive roller 147 and the support rollers 148 and 149 to form a loop-shaped movement path, and is substantially the same as the photosensitive drums 11y, 11m, 11c, and 11b. A toner image carrier that rotates in the direction of the arrow 146b at a speed. The surface of the intermediate transfer belt 146 on which the toner image is transferred becomes a toner image carrying surface 146a.

  As the intermediate transfer belt 146, a material that does not allow the fixing liquid 8 to permeate is selected and used. Among them, those containing one or more of fluororesins such as polytetrafluoroethylene (PTFE), a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether (PFA), and synthetic resins such as polycarbonate and polyimide are preferable. . In the present embodiment, on a polyimide substrate surface having a thickness of 100 μm, 1) a silicone rubber layer having a thickness of 300 μm, and 2) polytetrafluoroethylene (PTFE) and a copolymer weight of tetrafluoroethylene and perfluoroalkyl vinyl ether A laminate in which a surface coat layer having a thickness of 20 μm made of a fluororesin composition in which coalescence (PFA) is mixed at 8: 2 (weight ratio) is laminated in this order is used. The polyimide base material and the surface coat layer can be mixed with a conductive material such as furnace black, thermal black, channel black, and graphite carbon in order to adjust the electric resistance value as an intermediate transfer belt. Note that it is preferable to select each material so that the contact angle of the intermediate transfer belt 146 with respect to the fixing liquid 8 is larger than the contact angle with respect to the application roller included in the fixing liquid applying unit 150 described later. As a result, the fixing liquid 8 is difficult to adhere to the non-image portion where the toner image on the intermediate transfer belt 146 is not carried, the contamination of the intermediate transfer belt 146 by the fixing liquid 8 is prevented, and the usage amount of the fixing liquid 8 is also increased. Can be reduced.

  The driving roller 147 is provided so as to be rotatable around an axis by a driving unit (not shown). As the driving roller 147, for example, a hollow roller made of a metal such as aluminum can be used. In addition, a heater 148 such as a halogen lamp is provided inside the hollow roller of the driving roller 147. The operation of the heater 148 is controlled by the temperature sensor 149, heats the toner image transferred and carried on the intermediate transfer belt 146, and increases the binding force between the toners.

  The support rollers 148 and 149 are rotatably provided following the movement of the intermediate transfer belt 146 that moves in the direction of the arrow 146b by the rotation of the driving roller 147. As the support rollers 148 and 149, the same support rollers 121 and 122 as those in the fifth embodiment described above can be used. Of the two support rollers 148 and 149, the support roller 148 is provided to face a transfer fixing roller 154 described later.

  The belt cleaner 36 is provided so as to face the other support roller 149 with the intermediate transfer belt 146 interposed therebetween. The belt cleaner 36 is pressed against the toner image carrying surface 146a of the intermediate transfer belt 146 by a pressurizing unit (not shown) to apply the fixing liquid. The toner image on the toner image carrying surface 146a of the intermediate transfer belt 146 to which the fixing liquid 8 is applied by means 150 is transferred to the recording medium 7 by a transfer fixing roller 154 to be described later, and the toner image is fixed. The toner remaining on 146a and the fixing liquid 8 are removed.

  The fixing liquid applying unit 150 applies a fixing liquid 8 that softens and / or swells the toner image carried on the intermediate transfer belt 146 in contact. The fixing liquid applying unit 150 includes a fixing liquid tank that stores the fixing liquid 8, a coating roller that applies the fixing liquid 8 stored in the fixing liquid tank to the toner image transferred to the intermediate transfer belt 146, and a fixing to the coating roller. A supply roller for supplying the liquid 8, and a regulating roller for regulating the layer of the fixing liquid 8 supplied from the supply roller and carried by the coating roller, the configuration of which is the same as that of the fixing liquid applying unit 43 of the first embodiment. Since it is similar, description is abbreviate | omitted.

  Here, if a recording medium 7 having a small size is used, the amount of excess fixing liquid applied outside the size range of the recording medium 7 becomes too large, and the fixing that could not be removed by the belt cleaner 36 alone could not be removed. The liquid may adhere to the photosensitive drums 11y, 11m, 11c, and 11b.

  For such a problem, the image forming apparatus 141 according to this embodiment includes an intermediate transfer belt cleaner 151 as a fixing solution removing unit. The intermediate transfer belt cleaner 151 can be the same as the intermediate transfer belt cleaner 96 of the fourth embodiment described above.

  The intermediate transfer unit 142 transfers the toner images of the respective colors formed on the photosensitive drums 11y, 11m, 11c, and 11b while superimposing them on predetermined positions on the toner image carrying surface 146a of the intermediate transfer belt 146, and transfers the toner images. Form. The toner image is heated by the heater 152 to increase the bonding force between the toners, and the fixing liquid 8 is applied by the fixing liquid applying means 150. After the toner image to which the fixing liquid 8 is applied is transferred and fixed to the recording medium 7 by a transfer fixing roller 154 described later, the residual toner, offset toner, residual fixing liquid, paper dust, etc. on the toner image carrying surface 146a are transferred to the belt cleaner. The toner image is transferred again to the toner image carrying surface 146a.

  The transfer fixing unit 143 is a support roller 148 included in the intermediate transfer unit 142 described above, a transfer fixing roller 154 as a fixing unit, and another fixing solution removing unit that removes the fixing solution adhering to the transfer fixing roller 154. A transfer fixing roller cleaner 155.

  The transfer fixing roller 154 is provided in pressure contact with the support roller 148 via the intermediate transfer belt 146 and rotatably driven in the axial direction. When the toner image on the intermediate transfer belt 146 is transferred to the recording medium 7, a voltage having a polarity opposite to that of the toner is applied to the core of the transfer fixing roller 154.

  Further, the transfer and fixing roller 154 is a transfer and fixing roller cleaner 155 that is another fixing solution removing unit that removes the fixing solution that adheres to the transfer and fixing roller 154 that is a fixing unit by fixing the toner image to which the fixing solution 8 is applied. Is provided. As the transfer and fixing roller cleaner 155, the same one as the intermediate transfer belt cleaner 151 described above can be used.

  The transfer fixing roller cleaner 155 performs a cleaning operation only when the fixing solution adheres to the transfer fixing roller 154, and does not clean the transfer fixing roller 154 when the fixing solution does not adhere to the transfer fixing roller 154. For this reason, it is possible to reduce the occurrence of wear and scratches on the transfer fixing roller 154 due to the pressure contact between the transfer fixing roller 154 and the transfer fixing roller cleaner 155.

  In synchronization with the transfer of the intermediate transfer belt 146 onto which the toner image is transferred to the pressure contact portion between the transfer fixing roller 154 and the support roller 148, the recording medium 7 is fed from a recording medium transfer means 144 described later, and the intermediate transfer belt 146 is transferred to the intermediate transfer belt 146. The toner image on the transfer belt 146 is transferred and fixed on the surface of the recording medium 7 by pressing and applying a voltage. The recording medium 7 on which the toner image has been fixed is conveyed and discharged by the discharge means 145.

  The recording medium conveyance unit 144 includes a recording medium cassette 61 that stores the recording medium 7, a pickup roller 62 that feeds the recording medium 7 to the conveyance path P one by one, and a toner image on the intermediate transfer belt 146 that supports the support roller 148. And a pair of registration rollers 156a and 156b for feeding the recording medium 7 to the pressure contact portion in synchronization with being conveyed to the pressure contact portion between the transfer fixing roller 154 and the transfer fixing roller 154.

  The discharge unit 145 includes a conveyance belt 157 and a discharge roller 158. The conveyance belt 157 is an endless belt that is stretched between a driving roller 159 that is a recording medium carrier driving means for driving the conveyance belt 157 and a tension roller 125 to form a loop-shaped movement path. As the driving roller 159, the driving roller 124 used in the recording material conveying unit 114 of the fifth embodiment described above can be used. However, the driving roller 159 is not provided with a heater.

  The paper discharge roller 158 is a member that discharges the recording medium 7 on which the toner image is transferred and fixed and is conveyed to the conveyance belt 157 to a paper discharge tray 160 provided on the outer side surface of the image forming apparatus 1, and is in pressure contact with each other. It is comprised including the roller provided, and each roller is supported so that rotation drive is possible in each axial direction.

  According to the image forming apparatus 141, after the toner image is transferred and fixed on the recording medium 7 by the transfer fixing roller 154, the excess fixing liquid outside the size range of the recording medium 7 that remains on and adheres to the intermediate transfer belt 146 is transferred to the intermediate transfer belt 146. It can be removed by the belt cleaner 151. Accordingly, since the fixing liquid applied to the toner image on the intermediate transfer belt 146 is not removed, the toner image is not disturbed.

  The intermediate transfer belt cleaner 151 and the transfer fixing roller cleaner 155 are not limited to those using a roller as the removing member as described above, and various types can be used. As the removing means used in place of the intermediate transfer belt cleaner 151 and the transfer fixing roller cleaner 155, for example, a heating removing means for heating the fixing liquid 8 and evaporating and removing the solvent contained in the fixing liquid 8, a fixing liquid 8 Suction removal means for sucking and removing, including a blade-like removal member for scraping and removing the fixing solution, and including a belt-like removal member used in the pressure roller cleaner 97 of the fourth embodiment It may be.

  For example, when a heating removal unit that removes the fixing solution 8 by heating the fixing solution 8 and evaporating the solvent contained in the fixing solution 8 is used, the fixing solution 8 in which the solvent is evaporated hardly adheres to the recording medium 7. Even if it adheres, there is no risk of wrinkling of the recording medium 7. Further, even if the fixing solution 8 applied to the intermediate transfer belt 146 may adhere to the photosensitive drum, if such a heat removing unit is provided, the solvent in the fixing solution 8 is evaporated. Therefore, there is no risk of image omission.

1 is a diagram schematically showing a configuration of an image forming apparatus 1 according to a first embodiment of the present invention. FIG. 2 is an enlarged view showing a configuration of a main part (image forming unit 10y) of the image forming apparatus 1 shown in FIG. FIG. 2 is an enlarged view showing a configuration of a main part (transfer fixing unit 4) of the image forming apparatus 1 shown in FIG. FIG. 6 is a side view showing an outline of the configuration and operation of the fixing liquid cleaner 16y. FIG. 6 is a side view illustrating an operation of separating the intermediate transfer belt 32 from the photosensitive drums 11y, 11m, 11c, and 11b. 3 is a side view schematically showing the configuration of an intermediate transfer belt separating means 37. FIG. 4 is a side view schematically showing the configuration of a fixing solution removing unit 44. FIG. FIG. 6 is a plan view showing an application area and a removal area of the fixing liquid 8 on the surface of the transfer and fixing roller when an image is formed on B5 size paper. It is a figure which shows typically the structure of the principal part of the image forming apparatus 71 which is the 2nd Embodiment of this invention. It is a figure which shows typically the structure of the principal part of the image forming apparatus 71 which is the 2nd Embodiment of this invention. It is a figure which shows typically the structure of the principal part of the image forming apparatus 81 which is 3rd Embodiment of this invention. It is sectional drawing which shows schematically the structure of the image forming apparatus 91 which is 4th Embodiment of this invention. FIG. 12 is an enlarged cross-sectional view illustrating a configuration of a main part (transfer fixing unit 93) of the image forming apparatus 91 illustrated in FIG. It is a figure which shows the pressure roller cleaner 97 in which the web 98 and the pressure roller 45 are in a press-contact state. It is a figure which shows the pressure roller cleaner 97 in which the web 98 and the pressure roller 45 are in a separation state. It is sectional drawing which shows schematically the structure of the image forming apparatus 111 which is 5th Embodiment of this invention. FIG. 16 is a diagram illustrating a configuration of a fixing solution removing unit 116 of the image forming apparatus 111 illustrated in FIG. 15. It is sectional drawing which shows schematically the structure of the image forming apparatus 141 which is 6th Embodiment of this invention.

Explanation of symbols

1, 71, 81, 91, 111, 141 Image forming apparatus 2 Toner image forming means 3, 92, 112, 142 Intermediate transfer means 4, 93, 143 Transfer fixing means 5, 114, 144 Recording medium conveying means 6, 119, 145 Ejecting means 7 Recording medium 8 Fixing solution 10y, 10m, 10c, 10b Image forming unit 11y, 11m, 11c, 11b Photosensitive drum 12y, 12m, 12c, 12b Charging roller 13 Optical scanning unit 13y, 13m, 13c, 13b Laser Light 14y, 14m, 14c, 14b Developing device 15y, 15m, 15c, 15b Drum cleaner 16y, 16m, 16c, 16b Fixing solution cleaner 17y, 17m, 17c, 17b Toner 18y, 18m, 18c, 18b Developing roller 19y, 19m, 19c, 19b Development blade 20y, 0m, 20c, 20b Toner storage container 21a, 21b Agitation roller 22y Removal member 23, 23y Bearing 24, 24y, 39, 40, 95, 99 Position adjustment means 25y, 41, 104 Support plate 26, 26y Eccentric cam 27, 27y, 54, 105 Pressing spring 28, 28y Base 29, 29y Projection 30, 30y Rotating shaft 31, 31y Opening 32, 120, 146 Intermediate transfer belt 32a Toner image transfer surface 32b, 120b, 146b Intermediate transfer belt moving direction 33y, 33m, 33c, 33b Intermediate transfer roller 34, 94, 124, 147, 159 Driving roller 35, 125 Tension roller 36 Belt cleaner 37 Intermediate transfer belt separating means 38 Linking support member 42, 154 Transfer fixing roller 43, 115, 150 Fixing solution Giving means 44 72, 116 Fixing liquid removing means 45, 117 Pressure roller 46, 155 Transfer fixing roller cleaner 47, 127, 153 Temperature sensor 48, 126, 152 Heater 49 Fixing liquid tank 50 Application roller 51 Supply roller 52 Regulating roller 53 Pivot 55 Fixing solution storage tank 56 Supply pipe 57, 73, 74, 128 B5 wiping means 58, 75, 76, 129 Postcard wiping means 59 Full width wiping means 60, 130 Rotating support 61 Recording medium cassette 62 Pickup roller 63a, 63b, 131 a, 131 b, 156 a, 156 b Registration roller 64, 132, 158 Paper discharge roller 65, 133, 160 Paper discharge tray 77 Central wiping means 82 Suction removal means 83 Suction nozzle 84 Suction fan 85 Hose 96, 151 Intermediate transfer belt cleaner 97 Pressure roller cleaner 98 Web 100, 101 Rotating roller 102, 121, 122, 148, 149 Support roller 103 Rotating roller support 113 Secondary transfer roller 118 Recording medium supply means 123, 157 Conveying belt

Claims (21)

A toner image that includes a photosensitive drum that is exposed to light corresponding to image information to form an electrostatic latent image on the surface, and that forms a toner image made of dry toner containing a binder resin and a colorant on the photosensitive drum. The toner image formed on the photosensitive drum is transferred to the forming means, the toner image carrier that carries the transferred toner image, and the toner image on the toner image carrier is softened and / or swelled A fixing liquid applying means for applying the fixing liquid, a recording medium conveying means for carrying and conveying the recording medium, and a toner image provided with the fixing liquid applied by the fixing liquid applying means. An image forming apparatus including fixing means for fixing to a medium,
Size detection means for detecting the size of the recording medium;
An image forming apparatus comprising: a fixing solution removing unit that removes excess fixing solution applied outside the size range of the recording medium detected by the size detecting unit. The toner image carrier is
A recording medium carried by the recording medium conveying means;
Fixer removal means
A fixing liquid that is provided upstream of the fixing unit in the recording medium conveying direction of the recording medium conveying unit and adheres to the recording medium conveying unit before the toner image is fixed on the recording medium by the fixing unit. The image forming apparatus according to claim 1, wherein excess fixing liquid applied outside the size range is removed. The toner image carrier is
A rotary drive member that carries and rotates a toner image;
Fixer removal means
Provided on the upstream side of the rotation direction of the toner image carrier with respect to the fixing unit, and before the toner image is fixed on the recording medium by the fixing unit, the surplus on the surface of the toner image carrier applied outside the size range of the recording medium. The image forming apparatus according to claim 1, wherein the fixing liquid is removed. The toner image carrier is
A recording medium carried by the recording medium conveying means;
Fixer removal means
An excess fixing liquid that is provided downstream of the fixing unit in the recording medium conveying direction of the recording medium conveying unit and is applied outside the size range of the recording medium after the toner image is fixed on the recording medium by the fixing unit. 2. The image forming apparatus according to claim 1, wherein the fixing liquid adhering to the recording medium conveying means is removed. The toner image carrier is
A rotary drive member that carries and rotates a toner image;
Fixer removal means
An excess fixing liquid that is provided downstream of the fixing unit in the rotation direction of the toner image carrier and is applied to the recording medium after the toner image is fixed to the recording medium by the fixing unit. 2. The image forming apparatus according to claim 1, wherein the fixing liquid adhering to the surface of the image carrier is removed.   The image forming apparatus according to claim 1, further comprising another fixing solution removing unit that removes the fixing solution attached to the fixing unit by fixing the toner image to which the fixing solution is applied. apparatus.   The image forming apparatus according to claim 4, wherein the fixing solution removing unit includes a heating removing unit configured to heat and evaporate and remove the fixing solution.   The image forming apparatus according to claim 4, wherein the fixing solution removing unit includes a blade-shaped removing member that scrapes and removes the fixing solution.   The image forming apparatus according to claim 4, wherein the fixing liquid removing unit includes a roller-shaped removing member that adsorbs and removes the fixing liquid.   The image forming apparatus according to claim 4, wherein the fixing solution removing unit includes a strip-shaped removing member that adsorbs and removes the fixing solution.   11. The image forming apparatus according to claim 9, wherein the removing member has a contact angle of the fixing solution smaller than a contact angle of the fixing solution with respect to the toner image carrier.   The image forming apparatus according to claim 9, wherein the removing member is made of a liquid-absorbing material.   The image forming apparatus according to claim 1, wherein the fixing solution removing unit includes a suction removing unit that sucks and removes the fixing solution. Fixer removal means
2. One or more wiping means corresponding to a predetermined size of the recording medium and including one or more wiping means provided to wipe off and remove excess fixing liquid applied outside the size range of the recording medium. The image forming apparatus according to any one of? Fixer removal means
The length in the width direction, which is a direction orthogonal to the recording medium conveying direction by the recording medium conveying means, is variably provided, and for each recording medium having a different size, the recording medium is out of the size range corresponding to the size of each recording medium. 7. The image forming apparatus according to claim 1, further comprising a wiping unit set to a length capable of wiping off the excess fixing liquid applied to the image forming apparatus.   16. A position adjusting unit that adjusts the position of at least one of the photosensitive drum and the toner image carrier to enable the photosensitive drum and the toner image carrier to be separated from each other. The image forming apparatus according to any one of the above.   The image forming apparatus according to claim 1, further comprising a photosensitive member cleaning unit that removes a fixing solution adhering to the photosensitive drum. An intermediate transfer medium on which the toner image formed on the photosensitive drum is once transferred by the toner image forming means, and the toner image is transferred to and carried on the toner image carrier;
The image forming apparatus according to claim 1, further comprising an intermediate transfer medium cleaning unit that removes a fixing liquid of the intermediate transfer medium attached by transferring the toner image onto the toner image carrier. apparatus.   19. The heating apparatus according to claim 1, further comprising a heating unit that heats the toner image before the fixing solution is applied by the fixing solution applying unit to a temperature higher than the glass transition point of the toner. Image forming apparatus.   The length of the straight line connecting the ends located on the outermost sides of the area where the fixing liquid is removed by the fixing liquid removing means in the width direction, which is a direction orthogonal to the recording medium conveying direction of the recording medium conveying means, is the fixing liquid. 20. The image forming apparatus according to claim 1, wherein a length of the region to which the fixing liquid is applied by the applying unit is longer than a length in the width direction.   The length of the region to which the fixing liquid is applied by the fixing liquid applying unit in the width direction that is a direction orthogonal to the recording medium conveying direction of the recording medium conveying unit is longer than the length of the photosensitive drum in the width direction. The image forming apparatus according to any one of claims 1 to 20.

Images