JP2009251136A - Development device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce failure of a device by surely collecting liquid rings generated on the end face of a development roller 20, enhancing recycle efficiency of a fluid developer, suppressing contamination in the device and improving output images. <P>SOLUTION: A development device includes: the development roller 20 for being developed on a latent image carrier 10 carrying electrostatic latent images of the fluid developer containing solid content and a carrier liquid; and squeeze rollers 13, 13' squeezing the fluid developer developed with the latent image carrier 10. Axial lengths of the squeeze rollers 13, 13' are longer than that of the development roller 20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention develops an electrostatic latent image formed on an image carrier with a liquid developer composed of toner and carrier, and transfers and fixes the developer image developed by the developing device to a recording medium. The present invention relates to an image forming apparatus that forms an image.

  Various wet image forming apparatuses that develop and visualize an electrostatic latent image using a high-viscosity liquid developer in which a toner composed of a solid component is dispersed in a liquid solvent have been proposed. The developer used in this wet image forming apparatus has solid components (toner particles) suspended in an organic solvent (carrier) having high electrical insulation properties such as silicon oil, mineral oil, and edible oil. Is. These toner particles use very fine particles having a particle diameter of around 1 μm, and can achieve higher image quality than a conventional dry image forming apparatus using a particle diameter of 7 μm.

Patent Document 1 describes a wet image forming apparatus that can remove as much surplus toner as possible on a latent image carrier and prevent contamination of a transfer medium and peripheral members due to the surplus toner remaining. For this reason, in Patent Document 1, there is a coating means for applying a liquid developer with a predetermined width to the developer carrier, and a surplus after development on the latent image carrier on the downstream side of the development region in the surface movement direction of the latent image carrier. A removing means for removing the toner is provided, and the excess toner removing area on the surface of the latent image carrier by the removing means is made wider than the liquid developer application area on the surface of the latent image carrier by the applying means. .
JP 2002-214920 A

  However, in Patent Document 1, there is no description about the application area of the liquid developer in the developer carrier (“developing roller” in the present invention), and the relationship between the axial length of the developer carrier and the application area. There is no disclosure about. Currently, there is a developing device that achieves downsizing of the apparatus by effectively using the width direction of the developing roller by applying the liquid developer to the entire width direction of the developing roller or just to the width direction. In such a developing device, a liquid developer pool is generated at the end surface of the developing roller, and this liquid pool is transferred to the latent image carrier to cause deterioration of the output image and to contaminate the inside of the apparatus. A problem has arisen that leads to equipment failure. Further, since the liquid pool generated on the developing roller cannot be collected, there is a problem that the recycling efficiency of the liquid developer is lowered.

  In order to solve the above-described problems, a developing device according to the present invention includes a developing roller that develops a latent image carrier that carries an electrostatic latent image of a liquid developer containing a solid content and a carrier liquid, and the latent image carrier. And a squeeze roller for squeezing the developed liquid developer, and the axial length of the squeeze roller is longer than the axial length of the development roller.

  The developing device according to the present invention further includes a cleaning member that contacts the squeeze roller and cleans the squeeze roller, and the length of the cleaning member in the axial direction of the squeeze roller is in the axial direction of the developing roller. It is characterized by being longer than the length.

  The developing device according to the present invention is characterized in that the cleaning member includes a blade and seal members provided at both ends of the blade.

  The developing device according to the present invention is characterized in that the seal member has an inclined surface inclined with respect to the blade.

  Further, the developing device according to the present invention is characterized in that the inclined surface of the seal member is disposed so as to cover the end surface of the developing roller.

  The developing device according to the present invention is characterized in that the seal member has a blade contact surface that contacts the end surface of the blade.

  Further, in the developing device according to the present invention, the seal member has a first leg portion and a second leg portion branched along a moving direction of the surface of the squeeze roller, and a side surface of the first leg portion is disposed on the blade. A contact surface is provided, and the back surface of the second leg portion is a roller contact surface that contacts the squeeze roller.

  In addition, an image system apparatus according to the present invention includes the developing device.

  As described above, according to the configuration of the present invention, the liquid ring generated on the end face of the developing roller is reliably recovered by the squeeze roller, and the recycling efficiency of the liquid developer is increased, and the contamination in the apparatus is suppressed, thereby outputting the output. It is possible to improve the image and reduce the failure of the apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a main configuration of an image forming apparatus according to an embodiment of the present invention. The four developing devices 30Y, 30M, 30C, and 30K are arranged at the lower part of the image forming unit with respect to the image forming unit arranged at the center of the image forming apparatus. The transfer unit 60) is disposed on the upper part of the image forming unit. Hereinafter, the image forming unit and the developing devices 30Y, 30M, 30C, and 30K will be described. However, since the configurations of the respective colors are the same, the alphabetical suffixes indicating the colors are omitted.

  The image forming unit includes a latent image carrier 10, a corona charger 11, an exposure unit 12, and the like. The exposure unit 12 has an optical system (not shown) such as a semiconductor laser, a polygon mirror, and an F-θ lens. The latent image carrier 10 is uniformly charged by the corona charger 11 and input by the exposure unit 12. Based on the image signal, a modulated laser beam is irradiated to form an electrostatic latent image on the charged latent image carrier 10.

  The developing device 30 generally includes a developer container 31 for storing the liquid developer of each color, a supply roller 32 for applying the liquid developer from the developer container 31 to the developing roller 20, and the like. The electrostatic latent image formed on the latent image carrier 10 is developed. The intermediate transfer member 40 is configured by an endless belt or the like, is stretched around a driving roller 41 and a tension roller 42, and is rotationally driven by the driving roller 41 while being in contact with the latent image carrier 10 at the primary transfer unit 50. In the primary transfer unit 50, a primary transfer roller 51 is disposed opposite to the latent image carrier 10 and the intermediate transfer member 40, and the developed latent image is set with a contact position with the latent image carrier 10 as a transfer position. The toner images of the respective colors on the carrier 10 are sequentially superimposed and transferred onto the intermediate transfer member 40 to form a full color toner image.

  In the secondary transfer unit 60, a secondary transfer roller 61 is disposed opposite to the driving roller 41 with the intermediate transfer member 40 interposed therebetween, and a cleaning device having a secondary transfer roller cleaning blade 62 is further disposed. Then, at the transfer position where the secondary transfer roller 61 is disposed, a single color toner image or a full color toner image formed on the intermediate transfer body 40 is conveyed on the sheet material conveyance path L such as paper, film, cloth, etc. Transfer to recording medium. Further, a fixing unit (not shown) is disposed downstream of the sheet material conveyance path L, and a single-color toner image or a full-color toner image transferred onto a recording medium such as paper is fused and fixed on the recording medium such as paper. Let

  The tension roller 42 stretches the intermediate transfer member 40 together with the belt driving roller 41, and a cleaning device having an intermediate transfer member cleaning blade 46 at a portion stretched on the tension roller 42 of the intermediate transfer member 40. Are disposed in contact with each other.

  Next, an image forming apparatus and a developing device according to an embodiment of the present invention will be described. FIG. 2 is a cross-sectional view illustrating main components of the image forming unit and the developing device 50. Since the configurations of the image forming unit and the developing device for each color are the same, the description is based on the yellow (Y) image forming unit and the developing device, and the subscript alphabet is omitted in this description.

  Along with the rotation direction of the outer periphery of the latent image carrier 10, the latent image carrier cleaning roller 16, the latent image carrier cleaning blade 18, the corona charger 11, the exposure unit 12, the developing roller 20 of the developing device 30, the first squeeze. A roller 13 and a second squeeze roller 13 'are arranged. A latent image carrier cleaning roller cleaning blade 17 cleans the latent image carrier cleaning roller 16. The first and second squeeze rollers 13 and 13 ′ are provided with first and second cleaning means 14 and 14 ′, respectively, as attached components.

  On the outer periphery of the developing roller 20, a developing roller cleaning means 21, a supply roller 32, and a toner compression corona generator 22 are disposed. A regulating blade 33 that adjusts the amount of liquid developer supplied to the developing roller 20 is in contact with the supply roller 32. Further, in the liquid developer container 31, a developer storage unit 312 and a recovery liquid storage unit 315 are formed by a partition unit 313, and a conveying screw 34 is provided in the developer storage unit 312 in the recovery liquid storage unit 315. A recovery screw 35 is accommodated therein. The liquid developer recovered by the recovery screw 35 passes through a filter to remove dust and is recycled after being adjusted in concentration by a recycle unit (not shown).

  A primary transfer roller 51 of the primary transfer unit 50 is disposed along the intermediate transfer body 40 at a position facing the latent image carrier 10, and an intermediate transfer body squeeze roller 53 and a backup roller are disposed downstream in the moving direction. 54, an intermediate transfer member squeeze device 52 comprising an intermediate transfer member squeeze roller cleaning blade 55 is disposed.

  The latent image carrier 10 is a photosensitive drum made of a cylindrical member that is wider than the developing roller 20 and has a photosensitive layer formed on the outer peripheral surface thereof. For example, the latent image carrier 10 rotates in a clockwise direction as shown in FIG. . In addition, the photosensitive drum is not limited to the cylindrical member of the present embodiment, and may be a member configured to support a latent image by a belt or the like. The photosensitive layer of the latent image carrier 10 is composed of an organic image carrier or an amorphous silicon image carrier. The corona charger 11 is disposed upstream of the nip portion between the latent image carrier 10 and the developing roller 20 in the rotation direction of the latent image carrier 10. A voltage is applied from a power supply device (not shown), and the latent image carrier 10. Is corona charged. The exposure unit 12 irradiates the latent image carrier 10 with laser light to the latent image carrier 10 charged by the corona charger 11 on the downstream side of the corona charger 11 in the rotation direction of the latent image carrier 10. An electrostatic latent image is formed.

  The developing device 30 includes a toner compression corona generator 22 that performs a compaction action, and a developer container 31 that stores a liquid developer in which toner is dispersed in a carrier at a weight ratio of approximately 20%. The developer container 31 is also provided with a recovery screw 35 that recovers the liquid developer in the recovery liquid storage unit 315.

  Further, the developing roller 20 carrying the liquid developer, a supply roller 32 for applying the liquid developer to the developing roller 20, a regulating blade 33 for regulating the amount of liquid developer applied to the developing roller 20, and a liquid developer A developer screw cleaning means 21 for cleaning the developing roller 20 and a toner compression corona generator 22 for bringing the liquid developer carried on the developing roller 20 into a compacted state. It has been.

  The liquid developer contained in the developer container 31 has a low concentration (1 to 2 wt%) and a low viscosity at a normal temperature using Isopar (trademark: exon) as a carrier. Not a volatile liquid developer having a solid particle having a mean particle size of 1 μm, in which a colorant such as a pigment is dispersed in a non-volatile resin having a high concentration and high viscosity at room temperature, an organic solvent, silicon oil, mineral oil or It is a liquid developer having a high viscosity (about 30 to 10000 mPa · s) added to a liquid solvent such as edible oil together with a dispersant and having a toner solid content concentration of about 20%.

  The supply roller 32 has a function of supplying a liquid developer to the developing roller 20. The supply roller 32 is a cylindrical member, and is a roller in which irregularities are formed by spiral grooves finely and uniformly engraved on the surface so as to easily carry the liquid developer on the surface. The supply roller 32 supplies the liquid developer from the developer container 31 to the developing roller 20. During the operation of the apparatus, as shown in FIG. 2, the conveying screw 34 rotates clockwise to supply the liquid developer to the supply roller 32, and the supply roller 32 rotates counterclockwise to supply the liquid to the developing roller 20. Apply developer.

  The regulation blade 33 is an elastic blade having a surface covered with an elastic body, and includes a rubber portion made of urethane rubber or the like that comes into contact with the surface of the supply roller 32 and a metal plate or the like that supports the rubber portion. The Then, the film thickness and amount of the liquid developer carried and conveyed by the supply roller 32 are regulated and adjusted, and the amount of liquid developer supplied to the developing roller 20 is adjusted.

  The developing roller 20 is a cylindrical member, and rotates counterclockwise around the rotation axis as shown in FIG. The developing roller 20 is provided with an elastic layer made of polyurethane rubber, silicon rubber, NBR or the like on the outer periphery of an inner core made of metal such as iron. The developing roller cleaning means 21 is disposed downstream of the developing nip where the developing roller 20 contacts the image carrier 10 in the rotational direction of the developing roller 20 and scrapes off and removes the residual developer remaining on the developing roller 20. To do.

  The toner compression corona generator 22 is an electric field applying means for increasing the charging bias of the surface of the developing roller 20, and the liquid developer conveyed by the developing roller 20 is subjected to an electric field at a position close to the toner compression corona generator 22. Is applied to compress the toner. The electric field applying means for compressing the toner may use a compaction roller or the like instead of the corona discharge of the toner compression corona generator 22 shown in FIG. Such a compaction roller is a cylindrical member, and has a structure in which a conductive resin layer or rubber layer is provided on the surface layer of a metal roller base, and is rotated clockwise in the direction opposite to the developing roller 20, for example. Good.

  On the other hand, the developer that is carried on the developing roller 20 and compressed with toner corresponds to the electrostatic latent image on the latent image carrier 10 by a desired electric field in the developing nip portion where the developing roller 20 contacts the image carrier 10. And developed. The remaining developer remaining after development is scraped off and removed by the developing roller cleaning means 21 and dropped into the developer recovery port 316 in the developer container 31 to be reused.

  The first and second squeeze means arranged on the upstream side of the primary transfer are constituted by first and second squeeze rollers 13 and 13 'and first and second cleaning means 14 and 14', respectively. . Since the functions are almost the same, the first squeeze means will be described here. The first squeeze roller 13 is disposed on the downstream side of the developer carrier 20 so as to face the latent image carrier 10. The surface is formed of an elastic roller member that is covered with an elastic body and rotates in sliding contact with the latent image carrying roller 10, collects excess developer of the toner image developed on the latent image carrying body 10, and collects toner in the visible image. Has the function of increasing the particle ratio.

  Further, the first cleaning means 14 presses and slides against the first squeeze roller 13 to clean the surface, and an excess developer mainly including an excess carrier from the developer developed on the latent image carrier 10. Recover. The excess developer collected from the first squeeze roller 13 travels along the back surface of the first cleaning unit 14 and then drops onto the back surface of the developing roller cleaning unit 21 together with the residual developer collected by the developing roller cleaning unit 21. To the developer recovery port 316.

  With such a configuration, the solid developer-rich residual developer containing a large amount of toner particles can be washed away with the carrier-rich surplus developer, and the inside of the apparatus can be kept clean. In addition, compared with the case where the excess developer from the first cleaning unit 14 is dropped directly on the collected liquid storage unit 315, the height at which the excess developer is dropped can be increased by dropping the excess developer onto the developing roller cleaning unit 21. It is possible to suppress the contamination in the apparatus by suppressing the amount of splashing by excessive developer dripping, and by suppressing the splashing.

  The second squeeze means is arranged downstream of the first squeeze means, and its function is substantially the same as that of the first squeeze means. In this embodiment, the excess developer collected by the second squeeze roller 13 ′ travels along the back surface of the second cleaning unit 14 ′ and is dropped onto the back surface of the first cleaning unit 14. With such a configuration, the same washing as between the first cleaning unit 14 and the developing roller cleaning unit 21 and the effect of suppressing the splash due to the excessive developer dripping are produced.

  As the squeeze means before the primary transfer, a plurality of squeeze means are provided in this embodiment, but a single squeeze means may be used. Further, one of the plurality of squeeze bodies 13 and 13 'may be configured to come into contact with or come into contact with each other depending on the state of the liquid developer.

  In the primary transfer unit 50, the developer image developed on the latent image carrier 10 is transferred to the intermediate transfer member 40 by the primary transfer roller 51. Here, the latent image carrier 10 and the intermediate transfer member 40 are configured to move at the same speed, so that the driving load of rotation and movement is reduced, and the disturbance effect on the visible toner image of the latent image carrier 10 is reduced. Is suppressed.

  The latent image carrier cleaning device disposed on the downstream side of the primary transfer faces the latent image carrier 10 and is disposed on the downstream side of the primary transfer unit 50, so that the transfer on the latent image carrier 10 is performed. The remaining liquid developer and untransferred liquid developer are cleaned. A bias voltage that attracts toner particles in the liquid developer is applied to the latent image carrier cleaning roller 16. Therefore, the liquid developer containing a large amount of toner particles is collected by the latent image carrier cleaning roller 16. The liquid developer rich in solid content collected by the latent image carrier cleaning roller 16 is scraped by the latent image carrier cleaning roller cleaning blade 17 in contact with the latent image carrier cleaning roller 16 and vertically below. Fall. The remaining carrier-rich liquid developer is scraped off from the latent image carrier 10 by the latent image carrier cleaning blade 18.

  The intermediate transfer body squeeze device 52 has an intermediate transfer body squeeze roller 53 formed of an elastic roller member that covers an elastic body and rotates in sliding contact with the intermediate transfer body 40, and the intermediate transfer body squeeze roller between the intermediate transfer body 40. A backup roller 54 disposed opposite to the intermediate transfer member 53 and a cleaning blade 55 that presses and slides against the intermediate transfer member squeeze roller 53 to clean the surface, and removes excess carrier from the developer primarily transferred to the intermediate transfer member 40. Has the function of collecting.

  FIG. 3A shows a front view of the main configuration of the developing device in the present embodiment, and FIG. 3B shows a cross-sectional view taken along the line DD ′ in FIG. Yes.

  As described with reference to FIG. 2, the developing device 30 includes the developing roller 20 and the first squeeze roller 13 that are sequentially disposed along the moving direction of the latent image carrier 10. On the outer periphery of the first squeeze roller 13, a first cleaning means 14 for scraping off the excess developer collected by the first squeeze roller 13 is disposed as shown in the figure. The first cleaning unit 14 includes a cleaning member A and a blade support member 143, and the main cleaning member A includes a blade 141 and a seal member 15.

  The blade 141 of the cleaning member A comes into contact with the first squeeze roller 13 shown in FIG. 3B at a predetermined contact angle. The blade 141 is made of an elastic member such as metal or rubber, and plays a role of scraping off excess developer collected by the first squeeze roller 13.

  The seal member 15 is provided at both ends of the cleaning member A, and one surface thereof is in contact with the first squeeze roller 13. As the seal member 15, for example, a member formed of an elastic member such as a polymer elastomer and elastically deforming according to an applied pressure is selected. By properly holding the seal member 15 in contact with the first squeeze roller 13 with a holding member, the excess developer on the first squeeze roller 13 is reliably recovered without leaking to the end of the first squeeze roller 13, The recycling efficiency of the liquid developer can be increased, and contamination in the apparatus can be prevented.

  Further, the squeeze roller becomes a region where the surface position is not stable in the vicinity of the end surface in the roller axial direction due to non-uniform diameters due to the formation process and rotational runout. In the region where the surface position is unstable, it is difficult to avoid leakage of the developer with the blade 141 having a narrow contact surface. However, by using the seal member 15, it is possible to make contact with a wide area. Excess developer can be reliably sealed even in an unstable region near the end surface in the axial direction of the roller.

  The blade support member 143 has a function of fixing the blade 141 and maintaining the contact angle and pressure of the blade 141 with the first squeeze roller 13 in an appropriate state. Usually, the blade support member 143 and the blade 141 are fixed by an adhesive or the like. In the present embodiment, the blade support member 143 is configured to be fixed to the back surface of the blade 141, but the blade 141 may be configured to be fixed to the back surface of the blade support member 143.

  With the above configuration, the developing roller 20 forms a toner image on the surface of the latent image carrier 10, and the first squeeze roller 13 collects excess developer from the toner image formed on the latent image carrier 10. The cleaning member A constituted by the blade 141 and the seal member 15 scrapes off the excess developer from the first squeeze roller 13, and the excess developer thus scraped off the back surface of the blade 141 and the blade support member 143. In order, it is dropped onto the back surface of the developing roller cleaning means 21 disposed below.

  As described above, in FIG. 3, the recovery of excess developer in the first squeeze unit has been described, but the second squeeze unit has substantially the same configuration except that the arrangement position is downstream of the latent image carrier 10. The description is omitted here.

  FIG. 4 is a front view of the main configuration of the present embodiment including the developing roller 20, the squeeze roller 13, the cleaning member A composed of the blade 141 and the seal member 15, and the blade support member 143. It is the figure which showed.

  First, the axial length of the first squeeze roller 13 and the developing roller 20, which is a feature of the present embodiment, is the axial length b (360 mm) of the first squeeze roller 13 in the axial direction of the developing roller 20. The surface area of the first squeeze roller 13 is arranged so as to cover the surface area of the developing roller 20. Due to this length relationship, the liquid ring generated at the end of the developing roller 20 can be reliably collected on the first squeeze roller 13.

  That is, the liquid ring generated at the end of the developing roller 20 is transferred to the latent image carrier 10, and the liquid ring transferred onto the latent image carrier 10 is first squeezed due to the above-described axial length relationship. It can be transferred to the roller 13 and collected. By collecting the liquid ring transferred to the latent image carrier 10 in this way, it is possible to maintain a good output image without contaminating the configuration of the transfer unit disposed downstream of the latent image carrier 10. It becomes. In particular, when the apparatus is stopped with the liquid ring attached to the surface of the latent image carrier 10, the liquid ring is dropped below the latent image carrier 10 to cause contamination in the apparatus. However, in the above configuration, since the liquid ring can be reliably recovered by the first squeeze roller 13, the inside of the apparatus can be kept clean, and failure due to contamination can be prevented.

  Next, in the present embodiment, the axial length c (360 mm) of the cleaning member A configured by the blade 141 and the seal member 15 is longer than the axial length a (352 mm) of the developing roller 20. The surface region of the cleaning member A that is formed is arranged so as to cover the surface region of the developing roller 20. By forming such a length relationship, the liquid ring generated at the end of the developing roller 20 can be more reliably collected by the cleaning member A, and the collected liquid storage unit 315 in FIG. The utilization efficiency of the liquid developer that is dropped and recycled can be increased.

  In the present embodiment, the axial length b of the first squeeze roller 14 is equal to the axial length c of the cleaning means A. The axial length relationship between the two is not necessarily the same, but the axial direction of the first squeeze roller 13 is sufficient to bring the seal member 15 of the cleaning means A into close contact with the roller so as to fully function. It is desirable that the length of the above is longer than the length of the cleaning means A.

  The cleaning unit A has two seal members 15 at both ends. In the present embodiment, the seal member 15 is disposed so as to cover the end portion of the developing roller 20. . By adopting this configuration, the liquid ring generated on the developing roller 20 can be reliably damped at both ends of the cleaning means A, and leakage to the end of the squeeze roller can be prevented. The seal member 15 has an inclined surface that is inclined with respect to the blade 141, and the inclined surface covers the developing roller 20. This point will be described in detail later.

  The length of the blade support member 143 is longer than the length c (344 mm) of the blade 141, and the blade support member 143 is configured to support the entire length of the blade 141. With this configuration, all of the excess developer scraped off by the blade 141 forms a flow path that flows along the back surface of the blade support member 143, thereby preventing contamination in the apparatus.

  As described above, in this embodiment, the length relationship between the developing roller 20, the first squeeze roller 13, the cleaning unit A, the blade 141, and the blade support member 143, and the arrangement of the seal member are set as described above, so that the latent image The excess developer recovered from the carrier 10 and the liquid ring generated by the developing roller 20 can be reliably recovered, and the recycling efficiency of the liquid developer can be improved and contamination in the apparatus can be suppressed.

  FIG. 5 shows a perspective view of the cleaning member A composed of the first squeeze roller 13, the blade support member 143, the blade 141 and the seal member 15 described so far.

  Next, the seal member 15 which is a feature of the present embodiment will be described with reference to FIGS. FIG. 6 is a perspective view of the seal member 15, and the figure shows the seal member 15 arranged on the right side in FIGS. 4 and 5 as viewed from the first squeeze roller 13 side. FIG. 7 shows the state of the seal member 15 when it is placed in contact with the first squeeze roller 13, FIG. 7 (a) is its front view, and FIG. 7 (b) is its side view. ing. FIG. 8 is a perspective view showing a state where the seal member 15 is actually arranged, and shows a state where the seal member 15 is fixed by the holder 144.

  The seal member 15 shown in FIG. 6 is an embodiment that is arranged on the right side in FIGS. 4 and 5. For example, the seal member 15 is formed of an elastic member such as urethane foam and is selected to be elastically deformed according to the applied pressure. In addition, the inclined surface b is formed so that the upper right side is cut out, and the first leg portion 151 and the second leg portion 152 that branch downward and extend are formed. The shape shown in FIG. 6 is a shape just in contact with the first squeeze roller 13. When the seal member 15 is formed, it may be formed in a shape as shown in the figure, but it may be formed in a flat plate shape and applied in pressure so as to have a shape as shown in the figure. When formed into a flat plate shape, the elastic body as the material of the seal member 15 may be simply punched, and the manufacturing cost can be reduced.

  In the surface formed in front of the seal member 15 in FIG. 6, an area indicated by a dot pattern from the upper part to the lower part of the second leg 152 is a roller contact surface a. When the roller contact surface a is in close contact with the first squeeze roller 13, the liquid developer can be reliably sealed.

  And the inclined surface b is formed in the right shoulder part of the sealing member 15 in FIG. As will be described later, the inclined surface b allows the liquid ring generated at the end of the developing roller 20 to be moved to the blade 141 side and collected.

  Furthermore, the right side surface of the first leg 151 in FIG. 6 is a blade contact surface c. By bringing the blade contact surface c into close contact with the blade 14, the liquid developer at the end of the blade 14 can be sealed. In the present embodiment, since the second leg portion 152 is pressed against the first squeeze roller 13, the surface of the first leg portion 151 opposite to the blade contact surface c is the exposed surface. By sufficiently applying a load to the exposed surface opposite to the blade contact surface c, the blade contact surface c of the first leg 151 can be brought into close contact with the blade 141 and sealed.

  As described above, the seal member 15 according to the present embodiment is configured to reliably seal the liquid developer at the roller end and the blade end regardless of the simple configuration. In addition, the sealing member 15 arrange | positioned at the left side becomes a symmetrical structure with respect to the right side.

  7 is a view when the seal member 15 described in FIG. 6 is applied to the first squeeze roller 13. FIG. 7 (a) is a front view, and FIG. 7 (b) is a side view as viewed from the left. ing.

  In this embodiment, since the length of the cleaning member A formed by the blade 141 and the seal member 15 is equal to the length of the squeeze roller 13, the end of the seal member 15 is the end of the squeeze roller 13. It will be arranged at the matching position. The seal member 15 seals the end portion of the squeeze roller 13 by the force pressed against the squeeze roller 13, but the direction of the force applied to the first leg 151 is different. In FIG. 7A, a leftward force F indicated by an arrow with respect to the surface opposite to the blade contact surface c, that is, in FIG. 7B, the first leg 151 is applied to the first leg 151. On the other hand, as indicated by a cross, a force F is applied from the front side of the paper toward the heel direction. By applying a force to the first leg 151 in this way, the blade contact surface c of the first leg 151 and the blade 141 can be brought into close contact with each other and reliably sealed.

  The seal member 15 is formed with the inclined portion b as described with reference to FIG. When the seal member 15 is disposed, the inclined portion b is inclined toward the blade 141. With this configuration, the liquid developer on the squeeze roller 13 is moved toward the inside of the roller. The blade 141 can be scraped off, and contamination of the end face of the squeeze roller can be prevented. The inclined portion b of the seal member 15 is preferably arranged so as to cover the end surface of the developing roller 20. With this configuration, a relatively large amount of liquid ring can be reliably recovered by the seal member 15.

  As described above, by using the seal member 15 of the present embodiment, it is possible to seal the liquid developer with a simple configuration. In this embodiment, the cleaning member A composed of the seal member 15 and the blade 141 is applied to the squeeze roller for collecting the liquid ring. However, in the effect of ensuring the sealing of the liquid developer, The squeeze roller need not be limited, and can be used as a cleaning member for various rollers in the image forming apparatus used in FIGS.

  FIG. 8 is a diagram illustrating a state where the seal member 15 is actually arranged, and illustrates a state where the seal member 15 is pressed and fixed by the holder 144. Although not shown, the force on the first squeeze roller 13 and the force F on the first leg 151 described with reference to FIG. 7 are applied to the back side of the holder 144, and the seal against the surface of the first squeeze roller 14 and the blade The seal with respect to the 141 end surface is ensured. In the embodiment of FIG. 8, the holder 144 has a shape having a function of fixing and positioning the blade support member 143. The state of the liquid ring generated on the end surface of the developing roller 20 on the first squeeze roller 13 is indicated by an arrow. The liquid ring recovered by the first squeeze roller 13 passes through the inclined surface of the seal member 15, the blade 141, It can be clearly seen that the blade is reliably collected through the blade support member 143.

  The first squeeze means including the first squeeze roller 13 and the first cleaning means 14 has been described above. However, by applying the same configuration to the second squeeze roller 14 and the second cleaning means 14 ′, excess development is performed. It becomes possible to more reliably collect the agent and the liquid ring generated at the end face of the developing roller. Further, if this squeeze means can have an n-stage configuration of three or more stages, further effects are produced.

  As described above, according to the configuration of the present invention, the liquid ring generated on the end face of the developing roller 20 is reliably recovered by the squeeze rollers 13 and 13 ′, thereby improving the recycling efficiency of the liquid developer and suppressing contamination in the apparatus. By doing so, it is possible to improve the output image and reduce the failure of the apparatus.

FIG. 3 is a cross-sectional view illustrating main components of the image forming apparatus. FIG. 3 is a cross-sectional view illustrating main components of a developing device and an image forming unit. The front view and sectional drawing of the main structure of a developing device. The front view which showed the length relationship of the main structure of a developing device. FIG. 3 is an overall perspective view of a squeeze roller and a cleaning member. The perspective view of a sealing member. The front view and side view of a squeeze roller and a cleaning member. Partial perspective view of squeeze roller and cleaning member

Explanation of symbols

10 (Y, M, C, K) ... latent image carrier, 11 (Y, M, C, K) ... corona charger, 12 (Y, M, C, K) ... exposure unit, 13 (Y, Y) ') ... squeeze roller, 14 (Y, Y') ... cleaning means, 141Y ... blade, 143Y ... blade support member, 144Y ... holder, 15Y ... seal member, 151Y ... first leg, 152Y ... second leg, 16Y ... latent image carrier cleaning roller, 17Y ... latent image carrier cleaning roller cleaning blade, 18Y ... latent image carrier cleaning blade, 20 (Y, M, C, K) ... developing roller, 21Y ... developing roller cleaning means, 22Y: Toner compression corona generator, 30 (Y, M, C, K) ... Development device, 31 (Y, M, C, K) ... Developer container, 312Y ... Developer storage unit, 313Y ... Partition unit, 3 5Y: Recovery liquid storage unit, 316Y: Developer recovery port, 32Y ... Supply roller, 33Y ... Restriction blade, 34Y ... Conveying screw, 35Y ... Recovery screw, 40 ... Intermediate transfer member, 41 ... Belt drive roller, 42 ... Tension roller 46, intermediate transfer member cleaning blade, 50 (Y, M, C, K) ... primary transfer portion, 51 (Y, M, C, K) ... primary transfer backup roller, 52 (Y, M, C, K) Intermediate transfer member squeeze device 53 Intermediate transfer member squeeze roller 54 Intermediate transfer member squeeze backup roller 60 Secondary transfer unit 61 Secondary transfer roller 62 Secondary transfer roller cleaning blade

Claims (8)

A developing roller that develops a latent image carrier that carries an electrostatic latent image of a liquid developer containing a solid content and a carrier liquid;
A squeeze roller for squeezing the liquid developer developed on the latent image carrier,
The length of the squeeze roller in the axial direction is longer than the length of the developing roller in the axial direction. A cleaning member that contacts the squeeze roller and cleans the squeeze roller;
The developing device according to claim 1, wherein an axial length of the squeeze roller of the cleaning member is longer than an axial length of the developing roller. The developing device according to claim 1, wherein the cleaning member includes a blade and seal members provided at both ends of the blade. The developing device according to claim 3, wherein the seal member has an inclined surface inclined with respect to the blade. The developing device according to claim 4, wherein the inclined surface of the seal member is disposed so as to cover an end surface of the developing roller. The developing device according to claim 3, wherein the seal member has a blade contact surface that contacts an end surface of the blade. The seal member has a first leg portion and a second leg portion branched along the moving direction of the surface of the squeeze roller,
The side surface of the first leg is the blade contact surface,
The developing device according to claim 6, wherein a back surface of the second leg portion is a roller contact surface that contacts the squeeze roller. An image forming apparatus comprising the developing device according to claim 1.

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