JP2007121399A - Fixing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent image deletion caused when fixing and to prevent offset in a fixing device by which an unfixed toner image on an image support body is fixed on the image support body by sticking fixing solution to the image support body. <P>SOLUTION: A rotating body for applying fixing solution 40 in roller shape or the like is used to apply the fixing solution to the image support body 23 such as paper to fix the unfixed toner image 50 on the image support body. In such a fixing device 25, the rotating body for applying the fixing solution 40 is equipped with an elastic fixing solution holding member 45 formed by using porous material, for example, and a fixing solution partition member 46 provided around the fixing solution holding member and having apertures through which the fixing solution held by the fixing solution holding member passes in a dispersed state. Then, the rotating body for applying the fixing solution 40 is installed to be pressed on the image support body 23 on a support plate 41 by bringing the fixing solution partition member into contact therewith. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine thereof. In particular, charging, writing, and development are performed to form a toner image on the image carrier, and the toner image is transferred directly or indirectly via an intermediate transfer member to record the image on an image support such as paper. The present invention relates to an electrophotographic image forming apparatus. The present invention also relates to a fixing device that fixes unfixed toner after toner image transfer onto an image support in such an image forming apparatus.

  Image forming apparatuses such as printers, facsimiles, and copiers record images including characters, symbols, and the like on an image support such as paper, cloth, and OHP film based on image information. There are various types of such image forming apparatuses. Among them, electrophotographic image forming apparatuses are currently used in offices because they can record high-definition images on plain paper at high speed. Widely used.

  In an electrophotographic image forming apparatus, a charging device, a writing device, a developing device, a transfer device, a cleaning device, a charge eliminating device, and the like are arranged around a drum-shaped or belt-shaped image bearing member, and charged with the rotation of the image bearing member. After that, writing is performed to form an electrostatic latent image on the surface of the image carrier, and the electrostatic latent image is developed by attaching toner to form a toner image on the image carrier. Is transferred directly or indirectly via an intermediate transfer member such as a belt, and an image is recorded on the image support. Then, the image support after the toner image transfer is guided to the fixing device, and the unfixed toner is fixed on the image support. On the other hand, the surface of the image carrier after the image transfer is cleaned with a cleaning device and the charge is removed. Prepared for formation.

  In this type of electrophotographic image forming apparatus, as a fixing device, the fixing speed is fast and the fixed image quality is good. A thermal fixing method for fixing on an image support is widely used. However, in an image forming apparatus using such a heat fixing type fixing device, a large amount of electric power is consumed because the toner is heated. Adoption of a low power consumption fixing device is strongly desired. Further, the fixing device of the thermal fixing type has a problem that the startup time until the start of fixing is long.

  Therefore, in a conventional fixing device, for example, as described in Patent Document 1 below, a fixing solution comprising a softening material that dissolves or semi-dissolves toner and a solvent that disperses or dissolves the softening material is used. The fixing solution is sprayed or dropped to adhere to the image support after image transfer, the toner is dissolved or semi-dissolved, and then the fixing solution is dried to fix the unfixed toner on the image support. A method has been proposed.

  Since this type of fixing device does not require toner heat treatment unlike the case of the thermal fixing method, it can be said to be a fixing method suitable for energy saving measures with low power consumption. However, in this fixing method, there are various problems to be solved by applying a large amount of fixing solution to the image support.

  That is, 1) When water is used as the solvent of the fixing solution, this large amount of water swells the paper fibers as the image support. As a result, the melted toner reaches the back surface of the image support to cause image back-through, which degrades the image quality. 2) Absorption of a large amount of moisture causes wrinkles and curls on the image support, which significantly impairs stable and high-speed image support transport as an image forming apparatus. 3) If this large amount of water is removed by evaporation using a drying device, power consumption comparable to that of the heat fixing method is required. 4) In order to use a large amount of fixing solution, it is necessary to change the fixing solution frequently. If a large-capacity fixing solution tank is used, the size of the fixing device increases, and the size of the image forming apparatus decreases. There were problems such as obstructing.

  For this reason, in order to solve such problems 1) to 4), among the conventional fixing systems, as described in, for example, Patent Document 2 below, an inkjet recording system is used, and an image support is used. It has been proposed to apply the fixing liquid only to the toner image based on the positional information of the upper toner image or the positional information of the toner image on the image carrier before being transferred to the image support.

  However, when a serial type is employed as the ink jet recording method, there is a limit to the speed at which the recording head can be scanned serially, and thus there is a problem that cannot be used for medium speed machines and high speed machines with high recording speeds. there were. In addition, when a line type is adopted as the ink jet recording method, such a problem of the recording speed is solved, but there is a problem that it is difficult to maintain all the reliability of many nozzles. It was. For example, when the discharge of the fixing liquid from several nozzles becomes impossible, the area where the fixing liquid is not applied occurs when the discharge direction of the fixing liquid from the nozzles changes. In addition, the toner in that region is not fixed, and it adheres to hands and clothes and stains them. Moreover, in order to ensure reliability, it is necessary to prepare a large and expensive reliability maintenance mechanism.

  Further, when the fixing solution is discharged using the ink jet recording method, there is a possibility that the unfixed toner image may be disturbed by the momentum of the fixing solution. This image disturbance occurs because the toner is agitated by the kinetic energy when the fixing liquid collides with the toner, and the kinetic energy (mainly speed) of the fixing liquid is larger than the value used in the commercial inkjet recording method. It has been found that this can be prevented by a significant reduction. However, it has also been found that if the kinetic energy of the fixing solution is reduced, the straightness of the fixing solution is deteriorated, and the discharge direction of the fixing solution varies.

  On the other hand, the following Patent Document 3 and Patent Document 4 propose a contact-type fixing liquid application method using an application roller having an absorbing layer that absorbs the fixing liquid. In this coating method, the fixing solution is applied to the entire surface of the image support regardless of the presence or absence of toner, so that there is a problem that the consumption of the fixing solution is somewhat increased as described above. However, there is a great advantage in that the configuration is simple and the fixing device can be reduced in size and price, and the fixing solution can be reliably applied to all toners.

Japanese Patent No. 3290513 JP 2004-109751 A Japanese Patent Publication No.46-43439 Japanese Unexamined Patent Publication No. 63-2089

However, it has been found that the methods proposed in Patent Document 3 and Patent Document 4 cause the following problems when the fixing solution is applied.
First, image flow occurs as a result of toner being flushed with fixer. It has been found that this phenomenon occurs remarkably when the viscosity of the fixing solution is low in a place where the amount of toner is small, such as a highlight portion or a primary color portion.
Second, a so-called offset phenomenon occurs in which toner is transferred to the roller side. It has been found that this phenomenon occurs remarkably in places where the amount of toner is large, such as a solid part or a secondary color part.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to prevent an image flow occurring at the time of fixing and to prevent an offset in a fixing device that fixes a non-fixed toner image on an image support to the image support by attaching a fixing liquid to the image support. It is to prevent.

In order to achieve the above object, according to a first aspect of the present invention,
In a fixing device for fixing a non-fixed toner image on an image support by applying a fixer to an image support such as a sheet using a roller-like fixing solution applying rotator,
For example, an elastic fixing liquid holding member formed using, for example, a porous material and a fixing liquid provided around the fixing liquid holding member and held by the fixing liquid holding member are passed through the rotating body for fixing liquid application. A fixer partition member having openings dispersed therein,
The fixing liquid partition member is brought into contact with the fixing liquid application rotating body so as to press against the image support.

  When fixing an unfixed toner image on the image support, the fixing liquid partition member is brought into contact with the image support and pressed against the image support, and the fixing liquid application member is rotated to deform the fixing liquid holding member. The fixing liquid retained by the fixing liquid holding member oozes out through the opening of the fixing liquid partition member, and a fixing liquid pool is formed at a portion where the rotating body for fixing liquid application starts to be pressed against the image support. Then, it adheres to the outer surface of the partition between the openings and is applied to the image support using a rotating body for fixing solution application.

In order to achieve the above object, in the second aspect of the present invention,
In a fixing device for fixing a non-fixed toner image on an image support by applying a fixer to the image support using a rotating body for fixing solution application,
The fixing liquid applying rotator is constituted by an elastic rotator having a fixing liquid partition member provided on a peripheral surface and having concave portions dispersed in the fixing liquid partition member, and contacting the fixing liquid partition member to support the image. Install it against the body,
For example, a fixing liquid adhering member for adhering the fixing liquid formed by using a porous material is pressed against the fixing liquid partition member of the rotating body for fixing liquid application.

  Then, when fixing the unfixed toner image on the image support, the fixing liquid adhering member is generated by causing the fixing liquid accumulation to occur in the first part of the fixing liquid adhering member that is pressed against the rotation of the rotating body for fixing liquid application. As a result, the fixing solution is attached to the fixing solution partition member on the peripheral surface of the fixing solution applying rotator, and is applied to the image support to which the fixing solution partition member is pressed.

  In the present invention, the fixing solution is composed of a softening material such as a fatty acid ester that softens the toner and a solvent such as water that disperses or dissolves the softening material, and is preferably odorless and harmless to the human body. Is used. As a result, by attaching the fixing solution, the unfixed toner is dissolved or semi-dissolved with a softening material and fixed on an image support such as paper, cloth, or OHP film.

  The fixing liquid partition member is formed by using a film material or a mesh cloth made by weaving fibers. Then, the fixing solution held by the fixing solution applying rotator is applied to the image support using the fixing solution applying rotator in contact with a fixing solution partition member made of a film material or mesh cloth.

  The fixing liquid partition member may be formed by roughening the outer surface of the partition wall between the openings or the recesses, or forming a recess in the outer surface of the partition wall. Then, the fixing solution is attached to the outer surface of the roughened partition wall, or the fixing solution is attached to the outer surface of the partition wall in a recess.

  In order to achieve the above object, according to a third aspect of the present invention, an image forming apparatus includes the fixing device according to the first or second aspect described above. Then, the toner image on the image support formed by transferring from the image carrier is fixed by the fixing device of the first or second aspect described above.

  According to the first aspect of the present invention, since the openings are dispersed in the fixing liquid partition member provided around the fixing liquid holding member, when the rotating body for fixing liquid application is pressed against the image support, the gap between the openings is reduced. The image can be prevented from flowing by partitioning with a partition wall, and the fixing solution adheres to the outer surface of the partition wall between the openings. Therefore, even if the fixing solution application rotating body is pressed against the image support body, It is possible to prevent the toner from being offset to the fixing liquid partition member.

  According to the second aspect of the present invention, in addition to the effect of the first aspect of the invention, the fixing liquid is securely held by the fixing liquid holding member, and the fixing liquid applying rotator is pressed against the image support. As a result, the fixing liquid holding member can be deformed and the fixing liquid held thereby can ooze out through the opening of the fixing liquid partition member.

  According to the third aspect of the present invention, since the concave portions are dispersed in the fixing liquid partitioning member on the peripheral surface of the fixing liquid application rotator, the concave portions are pressed when the fixing liquid application rotator is pressed against the image support. It is possible to prevent image flow by partitioning with a partition wall between them, and since the fixing liquid adheres to the outer surface of the partition wall between the recesses, the image support body can be used even if the fixing liquid coating rotating body is pressed against the image support body. It is possible to prevent the upper toner from being offset to the fixing liquid applying rotator.

  According to the fourth aspect of the invention, in addition to the effect of the third aspect of the invention, the fixing liquid is securely held by the fixing liquid adhesion member, and the fixing liquid is pressed against the rotating body of the fixing liquid application rotating body. A fixing liquid pool is generated between the fixing member and the fixing member, and the fixing solution can be attached to the peripheral surface of the fixing member applying rotator.

  According to the invention described in claim 5, in addition to the effect of the invention described in any one of claims 1 to 4, openings or recesses are dispersed in the fixing liquid partition member of the rotating body for fixing liquid application. Therefore, when the fixing liquid application rotator is pressed against the image support, it is possible to prevent image flow by partitioning with the partition between the openings or the recesses, and the fixing liquid adheres to the outer surface of the partition. Even when the partition member is pressed against the image support, the toner on the image support can be prevented from being offset to the fixing liquid partition member.

  According to the invention described in claim 6, in addition to the effect of the invention described in any one of claims 1 to 4, openings or recesses are dispersed in the fixing liquid partition member of the rotating body for fixing liquid application. Therefore, when the fixing liquid application rotator is pressed against the image support, it is possible to prevent image flow by partitioning with the partition between the openings or the recesses, and the fixing liquid adheres to the outer surface of the partition. Even when the partition member is pressed against the image support, the toner on the image support can be prevented from being offset to the fixing liquid partition member.

  According to the invention described in claim 7, in addition to the effect of the invention described in any one of claims 1 to 6, the outer surface of the partition wall between the openings or the recesses is roughened, so that it adheres to the outer surface of the partition wall. The fixed fixer can be reliably held. As a result, even if the width of the partition wall is slightly increased, offset can be prevented, and the fixing liquid partition member can be easily processed by increasing the width of the partition wall.

  According to the invention described in claim 8, in addition to the effect of the invention described in any one of claims 1 to 6, a recess is formed on the outer surface of the partition between the openings or the recesses. It is possible to reliably hold the fixing solution adhering to the outer surface. As a result, even if the width of the partition wall is slightly increased, offset can be prevented, and the fixing liquid partition member can be easily processed by increasing the width of the partition wall.

  According to the ninth aspect of the present invention, in addition to the effects of the first aspect of the present invention, the fixing liquid partition member has openings or recesses dispersed therein. When the body is pressed against the image support, the partition between the openings or recesses can be partitioned to prevent the image from flowing, and the fixing solution adheres to the outer surface of the partition between the openings or recesses. Even when the rotating body is pressed against the image support, it is possible to prevent the toner on the image support from being offset to the fixing liquid partition member.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 shows a main configuration of an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine thereof. The illustrated one is an electrophotographic tandem color image forming apparatus.

  Reference numeral 10 in the figure denotes an intermediate transfer member which is an endless belt-like image carrier. In the illustrated example, the intermediate transfer member 10 is provided so as to rotate around one drive roller 12 and two driven rollers 13 and 14 so as to rotate clockwise in the drawing. Needless to say, the number of rollers around which the intermediate transfer member 10 is wound is not limited to three, and it may be wound around four or more rollers such as a roller for adjusting the offset of the intermediate transfer member 10 separately.

  Around the intermediate transfer member 10, four images of black, yellow, magenta, and cyan are formed in order along the traveling direction of the intermediate transfer member 10 on a horizontal portion stretched between the driving roller 12 and the driven roller 13. Stations 15K, 15Y, 15M, and 15C are arranged side by side to constitute a tandem imaging device 16. Although not shown, an exposure device and the like are further provided on the tandem image forming device 16.

  A secondary cleaning device 17 is provided on the left side of one driven roller 13 of the intermediate transfer member 10. A secondary transfer device 18 is provided below the other driven roller 14. In the illustrated example, the secondary transfer device 18 is configured by winding a secondary transfer belt 20 that is an endless belt between two rollers 19. The secondary transfer device may be a roller-like one instead of the illustrated example, and a non-contact charger may be arranged.

  Under the intermediate transfer body 10, a paper transport path that is an image support transport path that transports a paper 23 that is an image support through a secondary transfer position 22 between the intermediate transfer body 10 and the secondary transfer belt 20. P is provided, a registration roller 24 is disposed upstream of the secondary transfer position 22 along the paper conveyance path P, and a fixing device 25 is disposed downstream.

  The four image forming stations 15K, 15Y, 15M, and 15C have the same configuration as shown in FIG.

  Reference numeral 30 in the drawing denotes a photosensitive member which is a drum-shaped image carrier. Around the photosensitive member 30, a developing device 32, a primary transfer device 33, a primary cleaning device 34, a charge removal device 35, and the like are arranged in order from the charging device 31 disposed above in the rotation direction indicated by the arrow in the drawing.

  The charging device 31 employs a contact charging method using a charging roller, but may employ a non-contact charging method using a scorotron charge or the like. The developing device 32 includes a stirring unit and a developing unit (not shown), and each color developer is accommodated therein. The developer that has not contributed to development in the developing unit is returned to the stirring unit and reused. The toner concentration in the agitation unit is controlled so as to be constant as detected by the toner concentration sensor. The toner constituting the developer is made of a resin material colored in each color. Examples of the resin constituting the toner include polystyrene resin, polypropylene resin, polyacrylic resin, and polyester resin.

  In the illustrated example, the primary transfer device 33 employs a transfer roller system and is disposed so as to be pressed against the photoconductor 30 with the intermediate transfer body 10 interposed therebetween. A non-contact corona charger can also be used. In the primary cleaning device 34, here, a cleaning blade 36 that presses the front end against the photoreceptor 30 is used as a cleaning member. The toner scraped off by the cleaning blade 36 can be collected and reused in the developing device 32 by a collection screw (not shown) or a toner recycling device. For example, a lamp is used as the static eliminating device 35.

  Then, as the photoconductor 30 rotates counterclockwise, the surface of the photoconductor 30 is uniformly charged by the charging device 31, and writing light L (Lk, Ly, Lm, and Lc in FIG. 1) is obtained by an exposure device (not shown). Are formed on the photoconductors 30, respectively, and each color toner is attached by the developing device 32 to make the electrostatic latent images visible, and each color is monochromatic on each photoconductor 30. A toner image is formed.

  As each photoconductor 30 rotates, the intermediate transfer body 10 also rotates synchronously, and the single color toner images on each photoconductor 30 are sequentially transferred by the primary transfer device 33 to form a composite color image on the intermediate transfer body 10. . After the toner image has been transferred, the surface of the photoconductor 30 is cleaned by the primary cleaning device 34, and then is neutralized by the charge eliminating device 35 to be initialized, and is prepared for another image formation starting from the charging device 31 again.

  The sheet 23 is conveyed through the sheet conveyance path P and is sent to the secondary transfer position 22 by the registration roller 24 in time with the synthesized color image formed on the intermediate transfer body 10. Then, the composite color image on the intermediate transfer member 10 is transferred to the paper 23 by the secondary transfer device 18, conveyed by the secondary transfer device 18 to the fixing device 25, and unfixed toner is supplied to the paper by the fixing device 25. After fixing to 23, the paper is discharged to a paper discharge stack section (not shown).

  On the other hand, the intermediate transfer body 10 after image transfer is cleaned by the secondary cleaning device 17 to prepare for image transfer again.

FIG. 3 shows an exemplary configuration of the fixing device 25 provided in the color image forming apparatus shown in FIG.
Reference numeral 40 in the figure denotes a fixing liquid application roller which is a rotating body for fixing liquid application. The fixing liquid application roller is urged by a spring (not shown) and pressed against the support plate 41 across the paper transport path P to form a fixing nip having a predetermined width. The sheet is formed and placed so as to be pressed against the sheet 23 passing through the fixing nip on the sheet conveyance path P. The fixing device 25 is provided with a pair of transport rollers 42 upstream of the fixing nip and a pair of paper discharge rollers 43 downstream.

  The fixing liquid application roller 40 includes a rotating shaft 44, a fixing liquid holding member 45 provided around the rotating shaft 44, and a fixing liquid partition member 46 provided around the fixing liquid holding member 45. The fixing liquid holding member 45 is made of a porous material having elasticity, and an elastically deformable sponge or the like can be suitably used. As the sponge, those having a desired thickness, hardness, pore diameter, and porosity are selected and used from commercially available sponge materials such as PVA and polyurethane widely used as a water absorption roller and a coating roller.

  Then, the fixing solution is held by the fixing solution holding member 45. The fixer is composed of a softening material that dissolves or semi-dissolves the toner and softens it, and a solvent that disperses or dissolves the softening material. It is preferably odorless and harmless to the human body. In this respect, the softening material includes fatty acid esters, specifically linear saturated fatty acid esters, aliphatic dibasic acid esters, and aliphatic dibasic acid dialkoxys. It is preferable to use a dialkyl ester or the like. Further, from the viewpoint of environmental protection, water is preferably used as the solvent. For the purpose of controlling the wettability of the fixing solution containing the softening material having a predetermined concentration to the unfixed toner and the penetration rate into the paper, the surfactant is used. It is also possible to add.

  In FIG. 4A, the fixing liquid partition member 46 is shown expanded. In (B), a part of the AA line cross section is expanded and shown.

  The fixer partition member 46 is made of a metal material such as stainless steel or nickel, and a resin material such as polyimide or polyethylene terephthalate, and is formed into a film having a thickness of about several tens of μm. As can be seen from FIG. 4, the fixing liquid partition member 46 has openings 47 dispersed therein, and partition walls 48 are formed between the openings 47. The opening 47 can be opened by etching or electroforming when the fixing liquid partition member 46 is a metal material, and can be etched or laser processed when the fixing liquid partition member 46 is a resin material.

  For example, square-shaped openings 47 of the same size are arranged vertically and horizontally in the fixing liquid partition member 46 made of a polyimide film of about 50 μm, and a partition wall 48 is formed between the openings 47. The width of the opening 47 is 50 to 100 μm, and the width of the partition wall 48 is 20 to 50 μm. The viscosity of the fixing solution is set to a range of 50, 100, and 500 mPa · s by adding a thickener. As a fixing liquid supply system to the fixing liquid holding member 45, as described in Patent Document 3, a fixing liquid may be supplied from the outside of the fixing liquid application roller 40, or as described in Patent Document 4. A method of supplying the fixing liquid from the inside of the fixing liquid application roller 40 may be used.

  When fixing the unfixed toner image 50 on the paper 23, as shown in FIG. 3, the fixing liquid partition member 46 is brought into contact with the fixing liquid application roller 40 against the paper 23, and the fixing liquid application roller 40 is contacted. Are rotated in synchronization with the pair of transport rollers 42. Then, the fixing liquid holding member 45 is elastically deformed and the fixing liquid held by the fixing liquid holding member 45 oozes out through the opening 47 of the fixing liquid partition member 46 and the sheet 23 fed by the pair of conveying rollers 42 is removed from the fixing nip. Put in.

  In this case, when the amount of fixing liquid that has oozed out from the opening 47 is not so large, when the fixing liquid partitioning member 46 is pressed against the paper 23 as shown in FIG. 5B from the state shown in FIG. When the fixing liquid adheres only to the portion corresponding to the opening 47 and passes through the fixing nip, the unfixed toner image 50 is fixed only to the portion on the paper 23 corresponding to the opening 47 as shown in FIG. The unfixed toner image 50 on the paper 23 is offset in the partition wall 48 between the openings 47.

  However, when the material of the fixing liquid holding member 45, the viscosity of the fixing liquid, the urging force of the fixing liquid application roller 40, and the like are adjusted, the portion where the fixing liquid application roller 40 starts to be pressed against the paper 23 as shown in FIG. That is, a desired fixer pool 52 is generated at the entrance of the fixing nip. As a result, as shown in FIG. 6A, the fixing liquid 53 adheres to the outer surface of the partition wall 48 between the openings 47, and the fixing liquid that adheres to the periphery of the fixing liquid application roller 40 as the fixing liquid application roller 40 rotates is shown in FIG. As shown in FIG. 6, when the toner is applied to the paper 23 and passes through the fixing nip, the unfixed toner image 50 is fixed on the paper 23 as shown in FIG. 6C, and the unfixed toner on the paper 23 is shown in FIG. The image 50 is fixed on the paper 23 like the fixed toner image 54.

  In this case, if the toner layer of the unfixed toner image 50 is two layers as shown in the figure, and only one layer of fixing liquid is applied to the paper 23, the fixing liquid is only half of the toner layer. Since the ink does not penetrate, the toner for one layer is offset to the partition wall 48 as shown in FIG.

  As described above, since the openings 47 are dispersed in the fixing liquid partition member 46 provided around the fixing liquid holding member 45, the partition wall 48 between the openings 47 is used when the fixing liquid application roller 40 is pressed against the paper 23. The flow of the fixing solution is limited by partitioning, and even when the viscosity of the fixing solution is low, the flow of the fixing solution can be restricted to prevent the image from flowing. Further, as shown in FIG. 6A, since the fixing liquid 53 is sufficiently adhered to the outer surface of the partition wall 48 between the openings 47, even if the fixing liquid application roller 40 is pressed against the paper 23, the toner on the paper 23 Can be prevented from being offset to the fixing liquid partition member 46.

FIG. 7 shows a configuration of another example of the fixing device 25 provided in the color image forming apparatus shown in FIG.
In this example, a fixing liquid application roller 40 which is a rotating body for fixing liquid application includes a rotation shaft 44, an elastic layer 56 provided around the rotation shaft 44, and a fixing solution partition member 46 provided around the elastic layer 56. And is composed of an elastic rotating body provided with a fixing liquid partition member 46 on the peripheral surface.

  Here, as the elastic layer 56, silicon rubber having a low hardness can be suitably used. Further, as the fixing liquid partition member 46, openings penetrating in the thickness direction may be dispersed in the same manner as in the above-described example. In this example, however, the thickness direction is obtained by half etching or the like as shown in FIG. The recesses 57 are dispersed and separated by the partition walls 58.

  Then, a roller-like fixing liquid adhering member 60 for applying a fixing liquid from the outside is pressed against the fixing liquid partition member 46 of the fixing liquid application roller 40 so as to rotate in the counter direction with respect to the fixing liquid partition member 46. . The fixing liquid attaching member 60 is formed using a porous material. For example, a porous member 63 is provided around the rotation shaft 62. As the porous material constituting the porous member 63, a sponge that can be elastically deformed is suitable as in the previous example, and a desired thickness, hardness, pore diameter, pores, etc. can be selected from commercially available sponge materials such as PVA and polyurethane. Select the one with the rate.

  At this time, by adjusting the material of the porous member 63 of the fixing liquid adhesion member 60, the viscosity of the fixing liquid, the urging force of the fixing liquid application roller 40, the rotational speed of the fixing liquid adhesion member 60, and the like, as shown in FIG. Then, a desired fixing liquid reservoir 61 is formed in a portion where the fixing liquid attaching member 60 starts to be pressed against the fixing liquid application roller 40.

  Then, when fixing the unfixed toner image 50 on the paper 23, as shown in FIG. 7, the fixing liquid partition member 46 is brought into contact and pressed against the paper 23 on the support plate 41, and the elastic layer 41 is elastically deformed. Thus, the fixing nip is formed, and the fixing liquid application roller 40 is rotated in synchronization with the pair of conveying rollers 42. At the same time, the fixing liquid adhering member 60 also rotates in the counter direction with respect to the fixing liquid applying roller 40, and the fixing liquid adhering member 60 adheres the fixing liquid to the fixing liquid partitioning member 46 on the peripheral surface of the fixing liquid applying roller 40, and The fixing solution is adhered to the outer surface of the partition wall 58 between the 57. Then, a fixing liquid that adheres around the fixing liquid application roller 40 is applied to the sheet 23 fed to the fixing nip, and the unfixed toner image 50 on the sheet 23 is fixed on the sheet 23 like the fixed toner image 54.

  As a result, since the concave portions 57 are dispersed in the fixing liquid partitioning member 46 on the peripheral surface of the fixing liquid application roller 40, when the fixing liquid application roller 40 is pressed against the sheet 23, the partition wall 58 between the concave portions 57 is partitioned and fixed. The flow of the liquid can be limited to prevent image flow. In addition, since the fixing liquid adheres to the outer surface of the partition wall 58 between the recesses 57, even if the fixing liquid application roller 40 is pressed against the paper 23, the toner on the paper 23 is prevented from being offset to the fixing liquid application roller 40. can do.

  The fixing solution adhesion member 60 is supplied with the fixing solution from the outside by dropping the fixing solution or immersing it in a tank in which the fixing solution is stored.

  By the way, when the widths of the openings 47 and the recesses 57 are equal to or larger than a predetermined value, the fixer flows in the openings 47 and the recesses 57, and an image flow occurs. Further, an offset is generated depending on the ratio between the width of the opening 47 and the width of the partition wall 48 and the ratio between the width of the recess 57 and the width of the partition wall 58. That is, offset is less likely to occur when [opening width or recess width]> [partition wall width], and on the contrary, offset is likely to occur when [opening width or recess width] <[partition wall width]. However, in processing the fixing liquid partition member 46, it is advantageous that the widths of the partition walls 48 and 58 are large.

  Now, the surface of the fixing liquid partition member 46 is roughened by using a sandblast method as shown in FIG. Then, the outer surfaces of the partition walls 48 and 58 between the openings 47 or the recesses 57 are roughened, and the fixing liquid attached to the outer surfaces of the partition walls 48 and 58 can be reliably held. Accordingly, even if the widths of the partition walls 48 and 58 are slightly increased, the offset can be prevented, and the fixing liquid partition member 46 can be easily processed by increasing the widths of the partition walls 48 and 58. be able to.

  In the example shown in FIG. 9B, a groove-like recess 65 as shown in the figure is formed on the outer surface of the partition walls 48 and 58 between the opening 47 or the recess 57 of the fixing liquid partition member 46. In this way, it is possible to reliably hold the fixing liquid that has entered the recess 65 and adhered to the outer surfaces of the partition walls 48 and 58. Accordingly, even if the widths of the partition walls 48 and 58 are slightly increased, offset can be prevented, and the fixing liquid partition member 46 can be easily processed by increasing the widths of the partition walls 48 and 58. It can be.

  FIG. 10A shows an expanded example of the fixing liquid partition member 46, and FIG. 10B shows a BB cross section thereof.

  In the above-described example, the fixing liquid partition member 46 is formed by using a film-like metal material or resin material and providing the opening 47 and the concave portion 57 by etching, electroforming, or laser processing. However, as shown in FIG. 10, for example, the fixing liquid partition member 46 can be formed using a mesh cloth that is used for screen printing or used for a filter. Mesh cloth is made by weaving resin and metal fibers at a high density of about 500 per inch.

  The use of such a fixing liquid partition member 46 has the advantage that the opening 47 can be made small and the adhesion to the paper 23 is improved. Therefore, the load for pressing the fixing liquid application roller 40 against the paper 23 is relatively high. There is also an advantage that can be kept low.

1 is a configuration diagram of a main part of a color image forming apparatus. 2 is an enlarged configuration diagram of one image forming station provided in the color image forming apparatus. FIG. FIG. 2 is a configuration diagram of an example of a fixing device provided in the color image forming apparatus shown in FIG. 1. (A) is a development view of a fixing liquid partition member constituting the fixing liquid application roller of the fixing device, and (B) is a partially enlarged view of a cross section taken along the line AA. FIG. 6 is a relationship diagram between a fixing liquid partition member and a sheet when an offset occurs, where (A) shows before contact, (B) shows when contact, and (C) shows after contact. FIG. 4 is a relationship diagram between a fixing liquid partition member and a sheet when no offset occurs. (A) is before contact, (B) is at contact, and (C) is after contact. (D) shows a case where the fixing liquid is insufficient and an offset occurs. FIG. 3 is a configuration diagram of another example of a fixing device provided in the color image forming apparatus shown in FIG. 1. FIG. 3 is a partially enlarged cross-sectional view of a fixing liquid partition member constituting a fixing liquid application roller of the fixing device. (A) is a development view of another example of the fixing liquid partition member, and (B) is a development view of still another example. (A) is a development view of still another example of the fixing liquid partition member, and (B) is a cross-sectional view taken along the line BB showing the relationship between the fixing liquid partition member and the sheet.

Explanation of symbols

23 Paper (image support)
25 Fixing device 40 Fixing liquid application roller (rotating body for fixing liquid application)
41 Support Plate 45 Fixing Liquid Holding Member 46 Fixing Liquid Partitioning Member 47 Opening 48 Partition Between Openings 50 Unfixed Toner Image 52 Fixing Liquid Reservoir 54 Fixing Toner Image 56 Elastic Layer 57 Recesses 58 Recessing Partitions 60 Fixing Liquid Adhering Member 61 Fixing Liquid pool 63 Porous member 65 Recess

Claims (9)

In a fixing device for fixing a non-fixed toner image on an image support by applying a fixer to the image support using a rotating body for fixing solution application,
A fixing liquid partitioning member having a fixing liquid holding member having elasticity and an opening provided around the fixing liquid holding member and through which the fixing liquid held by the fixing liquid holding member is dispersed in the rotating body for fixing liquid application. And
A fixing device, wherein the fixing device is installed so as to contact the fixing solution partition member and press the fixing solution applying rotating body against the image support.   The fixing device according to claim 1, wherein the fixing liquid holding member is formed using a porous material. In a fixing device for fixing a non-fixed toner image on an image support by applying a fixer to the image support using a rotating body for fixing solution application,
The fixing liquid applying rotator is constituted by an elastic rotator having a fixing liquid partition member provided on a peripheral surface and having concave portions dispersed in the fixing liquid partition member, and contacting the fixing liquid partition member to support the image. Install it against the body,
A fixing device, wherein a fixing liquid adhesion member for adhering a fixing liquid is pressed against the fixing liquid partition member of the rotating body for fixing liquid application.   The fixing device according to claim 3, wherein the fixing liquid adhesion member is formed using a porous material.   The fixing device according to claim 1, wherein the fixing liquid partition member is formed using a film material.   5. The fixing device according to claim 1, wherein the fixing liquid partition member is formed using a mesh cloth made by weaving fibers.   7. The fixing device according to claim 1, wherein the outer surface of the partition between the opening or the recess of the fixing liquid partition member is roughened.   7. The fixing device according to claim 1, wherein a recess is formed in an outer surface of the partition wall between the opening or the recess of the fixing liquid partitioning member.   An image forming apparatus comprising the fixing device according to claim 1.

Images