JP2015139971A - Coating applicator and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating applicator capable of easily changing the coating range of a coating agent with respect to a coating object.SOLUTION: A coating applicator 50 comprises: a coating roller 54 which is provided rotatably in a direction around an X axis and applies a treatment liquid Lq adhering to an outer peripheral surface to an intermediate transfer roller 37 by rotating in the direction around the X axis in a state of being brought into contact with the transfer roller 37; and a coating area control roller 56 which is provided turnably in the direction around the X axis, on the outer peripheral surface of which a contact area capable of coming in contact with the outer peripheral surface of the coating roller 54 and a separation area separating from the outer peripheral surface in such a state that the contact area comes in contact with the outer peripheral surface of the coating roller 54, are formed, and which comes in contact with the coating roller 54 rotating in the direction around the X axis. The ratio of the contact area and the separation area in an X axis direction of the coating area control roller 56 varies according to the position of the direction around the X axis, and the coating area control roller 56 turns in the direction around the X axis. Thereby, the coating area control roller 56 controls the adhesion area of the treatment liquid Lq with respect to the coating roller 54 in the X axis direction.

Description

  The present invention relates to a coating apparatus and an image forming apparatus. More specifically, the present invention relates to a coating apparatus that applies a coating agent to a coating target and an image forming apparatus including the coating apparatus.

  2. Description of the Related Art Conventionally, an image forming apparatus such as an ink jet printer that includes a head that discharges a recording liquid such as ink from a plurality of nozzles and performs ink jet recording is known.

  As an ink jet printer of this type, a conventional technique is known in which a pre-coating agent is applied onto an intermediate transfer member to suppress color boundary bleeding and feathering, and an image is formed on the intermediate transfer member and transferred to paper. (For example, refer to Patent Documents 1 to 3). The above-mentioned pre-coating agent is applied for the purpose of transferring the ink onto the paper without losing the droplet shape on the intermediate transfer member. This pre-coating agent has an effect of agglomerating or thickening the ink, and includes an ion reaction, a pH reaction, a UV reaction, and water absorption of a water-absorbing polymer.

  As a method for applying the pre-coating agent, there are an ink jet head, an application roller, and a spray nozzle as disclosed in Japanese Patent Application Laid-Open No. H11-228707. Here, in order to reduce the cost of the pre-coating agent per print, it is desirable not to apply the pre-coating agent to the entire surface of the intermediate transfer member but to apply the pre-coating agent only to the spot where the ink lands. Specifically, the selection range of the coating method is determined by the viscosity of the pre-coating agent, and a method such as an ink jet head at 20 mPa · s or less and an application roller or die coater with an anilox roller or the like is generally selected at 20 mPa · s or more. The application of the pre-coating agent by the inkjet head can make the application area the same as the ink ejection area, and the cost of the pre-coating agent can be reduced. However, since the viscosity of the pre-coating agent that can be discharged is 20 mPa · s or less, the selection range of the pre-coating agent is small. For this reason, when applying a pre-coating agent having a viscosity that cannot be ejected by inkjet using a coating roller type coating device having a simpler structure than that of a die coater, it is necessary to control the width direction of the coating area of the pre-coating agent.

  Moreover, in patent document 2, two removal means are arrange | positioned with the predetermined space | interval in the edge part circumferential surface of an application | coating roller. These removing means can be moved in the longitudinal direction of the coating roller by the driving means. The first coating liquid removal mechanism and the second coating liquid removal mechanism control the width direction of the coating range of the coating agent so that the coating agent is not coated at both ends of the coating roller. However, according to this method, the size in the width direction of the removing means is increased according to the width of the area where the application is not performed. Furthermore, since this removing means moves to both sides and requires space, there is a drawback that the size in the width direction of the apparatus becomes large. Further, the removal mechanism performs suction, and the configuration is complicated.

  Patent Document 3 discloses the width of a doctor that forms a paint reservoir between a coating roller and a backup roll that is positioned under the coating roller and sandwiches a substrate to be coated between the coating roller and the coating roller. The paint scraping member formed to have a narrower width is detachably provided below the doctor. While the tip of the paint scraping member is in contact with the application roller and supplying the paint to the paint reservoir, the application roller and the backup roll are rotated to partially remove the paint adhering to the outer peripheral surface of the application roller. By painting the plate to be painted while scraping with a member, it is painted while creating a portion where the paint is not applied to a part of the plate to be painted. However, this method can be replaced because the paint scraping member is detachable, but it cannot be changed freely.

  The present invention is an application device that applies an application agent to an application object, and is provided so as to be rotatable around a first axis, and rotates around the first axis while being in contact with the application object. An application roller that applies the application agent adhered to the outer peripheral surface to the application object, an application agent supply device that supplies the application agent to the application roller, and a direction around a second axis parallel to the first axis And a contact area that can contact the outer peripheral surface of the application roller on the outer peripheral surface, and is separated from the outer peripheral surface in a state where the contact area contacts the outer peripheral surface of the application roller. An application range control member that is in contact with the application roller that rotates around the first axis in a stopped state, and the application range control member includes the contact region and the separation region. Flat with the second axis The ratio of the appropriate direction changes according to the position in the direction around the second axis, and the position of the direction in the direction around the second axis changes to control the adhesion range of the coating agent in the first axis direction with respect to the application roller. It is a coating device.

  According to the present invention, when the application roller rotates while the application roller and the application range control member are in contact with each other, the part of the application agent corresponding to the contact area is removed from the surface of the application roller, and the application area corresponds to the separation area. Part of the coating agent remains on the surface of the coating roller. The coating agent coating range in the first axis direction of the coating roller can be easily adjusted according to the position of the coating range control member in the direction around the second axis.

1 is a diagram schematically showing the configuration of an ink jet printer according to a first embodiment of the present invention. 2A and 2B are diagrams illustrating an application range control roller provided in the ink jet printer of FIG. 1. FIG. 2A is a diagram viewed from a direction parallel to the rotation axis (X direction), and FIG. 2B (Z direction) arrow view, FIG. 2 (c) is a 2C (Y direction) arrow view of FIG. 2 (a). It is a figure which shows schematically the structure of the inkjet printer which concerns on the 2nd Embodiment of this invention.

<< First Embodiment >>
A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 schematically shows the configuration of an inkjet printer 100 as an image forming apparatus according to the first embodiment of the present invention. As will be described later, the ink jet printer 100 of the present embodiment includes an intermediate transfer roller 37 (intermediate transfer drum). In the following description, for convenience, the direction parallel to the rotation axis of the intermediate transfer roller 37 is the X axis direction, the direction orthogonal to the X axis is the Y axis direction, and the direction orthogonal to the XY plane (horizontal plane) (vertical direction) is the Z axis. The direction will be described as appropriate.

  The inkjet printer 100 can perform full color image formation. The ink jet printer 100 performs an image forming process based on an image signal (image data) corresponding to image information received from the outside. The ink jet printer 100 according to the present embodiment forms an image on a sheet-like recording medium such as plain paper generally used for copying, OHP sheets, cardboard, cardboard, cardboard, and envelopes. Can be performed. In this embodiment, a single-sided image forming apparatus capable of forming an image on one side of a transfer sheet S as a recording sheet as a recording medium will be described. However, the present invention is a double-sided image capable of forming an image on both sides of the transfer sheet S. The present invention can also be suitably applied to a forming apparatus.

  The ink jet printer 100 can form an image as an image corresponding to each color separated into yellow, magenta, cyan, and black, and serves as a recording liquid ejector that ejects a recording liquid as ink of the color. It has heads 61BK, 61C, 61M and 61Y as recording heads which are ink heads. In the present embodiment, all of the recording liquids (inks) ejected from the heads 61BK, 61C, 61M, and 61Y are aqueous recording liquids containing a colorant. Although not shown, each head 61BK, 61C, 61M, 61Y has, for example, a piezo-type movable actuator, is driven according to an image signal (image data), and is transferred via an intermediate transfer roller 37. A recording liquid is applied to S to form an image.

  The heads 61BK, 61C, 61M, and 61Y as recording head means are disposed at positions facing the outer peripheral surface of the intermediate transfer roller 37 that is an intermediate transfer drum disposed at a substantially central portion of the main body of the inkjet printer 100. . The heads 61BK, 61C, 61M, and 61Y are arranged in this order from the upstream side in the A1 direction, which is the movement direction of the intermediate transfer roller 37 and is the clockwise direction in FIG. In the drawing, BK, C, M, and Y added after the numerals of the reference numerals indicate members for black, cyan, magenta, and yellow. Although not shown in FIG. 1 because it overlaps in the depth direction of the paper surface, the heads 61BK, 61C, 61M, 61Y are lines provided in a form in which a plurality of heads 61BK, 61C, 61M, 61Y are arranged in parallel in the direction perpendicular to the paper surface of FIG. Head.

  The intermediate transfer roller 37 is rotated in the A1 direction, and is recorded in black, cyan, magenta, and yellow from each head 61BK, 61C, 61M, 61Y in a region facing each head 61BK, 61C, 61M, 61Y. The liquid is discharged and applied in a manner in which the liquids are sequentially superimposed. Thereby, the intermediate transfer roller 37 functions as a recording medium on which an image as a primary image is formed on a primary image forming surface as a surface thereof. As described above, the inkjet printer 100 has a tandem structure in which the heads 61BK, 61C, 61M, and 61Y are opposed to the intermediate transfer roller 37 and are arranged in parallel in the A1 direction.

  The recording liquid is discharged to the intermediate transfer roller 37 by the heads 61BK, 61C, 61M, and 61Y, that is, the recording liquid is applied at different timings from the upstream side to the downstream side in the A1 direction. As a result, the image areas of the respective colors of black, cyan, magenta, and yellow are overlapped at the same position on the intermediate transfer roller 37 to form an image.

  The ink jet printer 100 is also not shown in FIG. 1, but includes a paper transport unit that transports the transfer paper S in the + Y direction (see the black arrow in the figure) as the intermediate transfer roller 37 rotates in the A1 direction. And a sheet discharge table on which a large number of image-formed (in other words, printed) transfer sheets S conveyed by the sheet conveyance unit can be stacked.

  The ink jet printer 100 also has a cleaning device 40. The cleaning device 40 is provided so as to be able to come into contact with and separate from the intermediate transfer roller 37 and includes a cleaning blade 42 having wear resistance. From the intermediate transfer roller 37 after the ink is transferred to the transfer paper S, the intermediate transfer roller 37 is provided. The recording liquid remaining above or on the primary image forming surface is removed and cleaned (reset). This reset operation may be always performed or may be performed at a specific timing by control.

  The ink jet printer 100 is also disposed below the intermediate transfer roller 37 in the figure so as to face the intermediate transfer roller 37, and applies a treatment liquid (coating agent) having a predetermined composition and a predetermined state to the intermediate transfer roller 37. It has the coating device 50 which performs.

  The ink jet printer 100 also has a control unit (not shown) as a control means including a CPU, a memory, etc. (not shown) that controls the overall operation of the ink jet printer 100. The above-described ink ejection devices including the heads 61BK, 61C, 61M, and 61Y, a transport unit (not shown), the cleaning device 40, and a control board (not shown) of each head provided in the control unit include a printing unit. It is composed.

  The ink jet printer 100 also has a transfer roller 38. The transfer roller 38 sandwiches the transfer paper S with the intermediate transfer roller 37, and transfers the image on the intermediate transfer roller 37 to the transfer paper S while being driven to rotate by the intermediate transfer roller 37. To do. As is apparent from the above description, the ink jet printer 100 is an indirect image forming apparatus that indirectly forms an image on the transfer paper S using the intermediate transfer roller 37.

  The intermediate transfer roller 37 includes a support body 37a made of metal (for example, aluminum) and an elastic layer 37b formed on the support body 37a. A PFA resin (tetrafluoroethylene perfluorocarbon) (not shown) is formed on the outermost layer. Alkyl vinyl ether copolymer resin) layer is formed. For the elastic layer 37b, it is possible to use silicone rubber, nitrile rubber, urethane rubber, fluorine rubber, or an elastomer obtained by coating these with fluorine-based coating.

  The coating device 50 is a device for applying a predetermined treatment liquid Lq to the outer peripheral surface of the intermediate transfer roller 37 with a small coating unevenness and a small film thickness. The coating device 50 is downstream of the position where the cleaning device 40 cleans the intermediate transfer roller 37 in the A1 direction, and upstream of the position where the heads 61BK, 61C, 61M, 61Y discharge the recording liquid to the intermediate transfer roller 37. It faces the intermediate transfer roller 37. The coating device 50 applies the processing liquid Lq to the intermediate transfer roller 37 at this position.

  Here, the processing liquid Lq applied to the intermediate transfer roller 37 by the coating device 50 will be briefly described. The base of the treatment liquid Lq is a low polarity solvent that is incompatible with water, that is, phase-separated at room temperature. The treatment liquid Lq is obtained by emulsifying water containing a water-soluble polymer and a nonpolar solvent incompatible with the water using a surfactant. That is, the treatment liquid Lq has a form in which a water phase containing a water-soluble polymer is dispersed into a W / O emulsion in a state where the water-soluble polymer is dissolved using a surfactant in a nonpolar solvent. It has become. In the inkjet printer 100, an aqueous recording liquid is used as a recording liquid (ink), and this recording liquid is ejected from the heads 61BK, 61C, 61M, 61Y, and the ejected recording liquid and the processing liquid Lq are brought into contact with each other and mixed. . And by this contact etc., a process liquid inverts to an O / W emulsion and exhibits a thickening effect | action. The water-soluble polymer in the treatment liquid Lq thickens and aggregates the coloring component in the recording liquid, and the coloring component in the recording liquid bleeds onto the transfer paper S when the recording liquid is transferred to the transfer paper S. It has a function to prevent or suppress.

  The coating device 50 includes a processing liquid container 52, a coating roller 54, a coating range control roller 56, a squeeze roller 58, and a drive system (not shown).

  The processing liquid container 52 is formed of a box-shaped member that opens upward (on the intermediate transfer roller 37 side), and stores the processing liquid Lq therein.

  The application roller 54 is disposed below the intermediate transfer roller 37 (on the downstream side of the cleaning device 40 and on the upstream side of the head 61BK), and is opposite to the intermediate transfer roller 37 in a state where it is in contact with the intermediate transfer roller 37 at this position. By rotating in the direction A2, which is the direction, it functions as a processing liquid application member that applies the processing liquid Lq. The application roller 54 and the intermediate transfer roller 37 are set so that the rotational axis is substantially parallel (parallel to the X axis) and the length in the axial direction is substantially the same. The lower half of the application roller 54 is immersed in the processing liquid Lq accommodated in the processing liquid container 52.

  Here, the surface of the intermediate transfer roller 37 is set with materials, surface properties, etc. so that the receding contact angle with respect to the treatment liquid Lq is smaller than that of the surface of the application roller 54. That is, generally speaking, wettability refers to the affinity between the substrate and the liquid, such as static contact angle and surface tension, but the back contact angle of the dynamic contact angle depends on the viscosity of the liquid in addition to the affinity. The affected value is measured. In the inkjet printer 100 of this embodiment, the processing liquid Lq is well released from the application roller 54 (member with a large receding contact angle), and the processing liquid Lq is transferred to the intermediate transfer roller 37 (member with a small receding contact angle). It is possible to adsorb well. Therefore, it is possible to efficiently transfer the processing liquid Lq adhering to the surface of the application roller 54 to the surface of the intermediate transfer roller 37.

  The application range control roller 56 has a function of controlling the application range of the processing liquid Lq on the surface of the intermediate transfer roller 37. The application range control roller 56 is arranged on the upstream side in the rotation direction (A2 direction) of the application roller 54 with respect to the contact portion between the intermediate transfer roller 37 and the application roller 54. The application range control roller 56 is formed in a substantially cylindrical shape, and the rotation axis direction thereof substantially coincides with the application roller 54. The application range control roller 56 and the application roller 54 are arranged so that the outer peripheral surfaces thereof are partially in contact with each other. The application range control roller 56 can be rotated (rotated) and stopped (fixed) in any direction and angle around the rotation axis. The rotation operation of the application roller 54 and the rotation operation of the application range control roller 56 are controlled by an independent drive system.

  The application range control roller 56 and the application roller 54 are provided so as to be movable with a predetermined stroke in the vertical direction (direction in which the intermediate transfer roller 37 contacts and separates) as indicated by the black arrows in FIG. As a result, the application roller 54 moves between a position in contact with the intermediate transfer roller 37 (position indicated by a dotted line in FIG. 1) and a position spaced from the intermediate transfer roller 37 (position indicated by a solid line in FIG. 1). It is possible. In the coating device 50, the intermediate transfer roller is controlled by controlling the vertical position of the coating roller 54, that is, the contact and separation of the coating roller 54 (or both the coating roller 54 and the coating range control roller 56) with respect to the intermediate transfer roller 37. The application range of the treatment liquid Lq with respect to the circumferential direction 37 can be arbitrarily set. The position of the application range control roller 56 is set so that the outer peripheral surface does not contact the processing liquid Lq in the processing liquid container 52 regardless of the vertical position.

  2 (a) to 2 (c) are a side view, a plan view (viewed from the arrow B2 in FIG. 2 (a)), and a front view (viewed from the arrow B3 in FIG. 2 (a)) of the application range control roller 56. Figure) is shown respectively.

  As can be seen from FIGS. 2A to 2C, a groove 57 a (concave portion) extending in the circumferential direction is formed on the outer peripheral surface of the application range control roller 56.

  In the coating device 50 (see FIG. 1), the coating roller 54 is moved as shown in FIG. 1 in a state where the outer circumferential surface of the coating roller 54 and the outer circumferential surface of the coating range control roller 56 are in contact with each other and the coating range control roller 56 is stopped. When rotated in the A2 direction, the processing liquid Lq adhering to the outer peripheral surface of the application roller 54 comes into contact with the portion where the groove 57a of the application range control roller 56 is not formed (the outer peripheral surface of the application range control roller 56). The processing liquid Lq adhering to the existing portion is scraped off by the application range control roller 56 and falls into the processing liquid container 52. On the other hand, the processing liquid Lq adhering to the region of the outer peripheral surface of the application roller 54 facing the portion where the groove 57a of the application range control roller 56 is formed is not scraped off by the application range control roller 56 ( It passes through the groove 57a and remains attached to the outer peripheral surface of the application roller 54. Hereinafter, a region where the groove 57a is not formed (a region having a function of scraping off the processing liquid Lq) on the outer peripheral surface of the coating range control roller 56 is referred to as a coating restricting portion 57b, and a region where the groove 57a is formed. The same reference numerals as those of the grooves 57a are given and referred to as processing liquid passage portions 57a.

  Here, as can be seen from FIG. 2A, the processing liquid passage portion 57a (groove) is formed over a range of about 5/6 of the entire circumference of the application range control roller 56, and the remaining portion. The groove 57a is not formed in the region of about 1/6, and has a uniform height. Further, the treatment liquid passage portion 57a (groove) is formed so that the dimension (groove width) in the width direction (axial direction of the application range control roller 56) gradually increases from one end side to the other end side. One end (the narrowest width portion) of the groove 57a is formed at the center in the axial direction of the application range control roller 56, and the groove width is about ¼ of the axial length of the application range control roller 56. Is set. On the other hand, the groove at the other end (the widest portion) of the groove 57 a is set to 2/3 of the axial length of the application range control roller 56. That is, on the outer peripheral surface of the application range control roller 56, the processing liquid passage part 57a (area where the groove 57a is formed) and the application regulating part 57b (area where the groove 57a is not formed) according to the position around the axis. ) And the ratio is different.

  Therefore, in the coating device 50, by arbitrarily controlling the stop position of the coating range control roller 56, the position of the coating range control roller 56 that contacts the outer peripheral surface of the coating roller 54 is arbitrarily changed. Of the processing liquid Lq adhering to the outer peripheral surface of the application roller 54, the range of scraping from the outer peripheral surface of the application roller 54 and dropping it into the processing liquid container 52, in other words, the processing liquid Lq of the outer peripheral surface of the application roller 54 adheres. The range (which remains attached) can be arbitrarily determined.

  Similarly to the relationship between the intermediate transfer roller 37 and the application roller 54 described above, the surface of the application range control roller 56 is made of a material such that the receding contact angle with respect to the processing liquid Lq is smaller than the surface of the application roller 54. Surface properties are set. Accordingly, it is possible to efficiently remove the processing liquid Lq from the surface of the application roller 54 using the application range control roller 56.

  The squeeze roller 58 is a member for controlling the thickness of the processing liquid Lq applied on the intermediate transfer roller 37 by the application roller 54 uniformly and with high accuracy. For this reason, the squeeze roller 58 is required to have high precision of parts, and for example, the runout precision is desirably 10 μm or less. Note that the squeeze roller 58 may be omitted when it is not necessary to strictly control the film thickness of the processing liquid Lq formed on the intermediate transfer roller 37.

  Next, the operation of the ink jet printer 100 will be described. In the inkjet printer 100, the intermediate transfer roller 37 starts to rotate in the A1 direction while facing the heads 61BK, 61C, 61M, and 61Y in response to the input of a predetermined signal indicating the start of image formation. With this rotation, the application roller 54 is driven to rotate, and the processing liquid Lq applied to the outer peripheral surface of the application roller 54 that is being rotated is transferred to an area corresponding to the image formable area on the surface of the intermediate transfer roller 37 ( Adhere to.

  Here, in the ink jet printer 100 of the present embodiment, printing can be performed on a plurality of types of transfer paper S having different dimensions in the width direction. On the other hand, the dimension of the intermediate transfer roller 37 in the axial direction takes into account the width direction dimension of the maximum printable size paper (for example, when the A3 size is the maximum printable size, the axis of the intermediate transfer roller 37 The direction dimension is designed to be slightly longer than the width direction dimension of A3 paper. Accordingly, when printing is performed on the transfer sheet S having a size smaller in the width direction than the maximum size sheet, the corresponding ink is not ejected from the heads 61BK, 61C, 61M, and 61Y in the area where printing is not performed. Therefore, it is not necessary to apply the treatment liquid Lq over the entire axial direction (width direction) of the intermediate transfer roller 37.

  Therefore, in the ink jet printer 100 of the present embodiment, the adhesion range of the treatment liquid Lq adhered to the outer peripheral surface of the application roller 54 using the application range control roller 56 is determined according to the width direction dimension of the transfer sheet S to be printed. To control. Therefore, when a control device (not shown) that controls the coating device 50 receives a print start signal from the host control device, it rotates the coating range control roller 56 in accordance with the paper size information included in the signal, and the coating roller 54. That is, the application range control roller 56 is stopped at a preset position so that the processing liquid Lq adheres to the outer peripheral surface of the intermediate transfer roller 37 by a width corresponding to the paper size.

  According to the inkjet printer 100 according to the first embodiment described above, the range of the treatment liquid Lq applied to the surface of the intermediate transfer roller 37 can be controlled by the coating device 50 according to the paper size of the printing target paper ( Since the treatment liquid Lq is not applied to a range where the treatment liquid Lq is not required to be applied, the efficiency is good.

  Further, since the ratio between the treatment liquid passage portion 57a and the application regulating portion 57b in the application range control roller 56 of the application device 50 is different, the application is applied to the outer peripheral surface of the application roller 54 (that is, the intermediate transfer roller 37). The range of the treatment liquid can be arbitrarily selected. Therefore, the application range of the processing agent can be controlled corresponding to a plurality of types of transfer sheets S having different sizes (paper widths), and the efficiency is high.

  Further, since the application range of the treatment liquid Lq can be switched only by rotating the application range control roller 56, the apparatus is compact and control is easy.

<< Second Embodiment >>
Next, a second embodiment of the present invention will be described with reference to FIG. The configuration of the inkjet printer 200 according to the second embodiment is substantially the same as that of the first embodiment except that the arrangement / configuration of the coating apparatus 60 is different. Therefore, only the differences will be described below. Elements having the same configuration and function as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.

  As shown in FIG. 3, the inkjet printer 200 is different from the inkjet printer 100 according to the first embodiment (see FIG. 1) in that a transfer roller 38 is disposed below the intermediate transfer roller 37, and the intermediate transfer roller 37. The coating device 60 is disposed above the surface. For this reason, in the second embodiment, the rotation direction C1 of the intermediate transfer roller 37 is opposite to that in the first embodiment. Since the configurations and functions of the image recording system including the heads 61BK, 61C, 61M, and 61Y, the cleaning device 40, the paper transport unit (not shown), and the like are the same as those in the first embodiment, description thereof is omitted.

  Similar to the coating device (see FIG. 1) of the first embodiment, the coating device 60 has an outer periphery of the intermediate transfer roller 37 prior to the recording liquid (ink) ejected from each head 61BK, 61C, 61M, 61Y. This is an apparatus for applying a predetermined processing liquid Lq to a surface with a small coating unevenness and a thin film thickness. The coating device 60 includes a doctor blade 62, a gravure roller 64, a coating roller 66, and a coating range control roller 68.

  The doctor blade 62 is a squeegee member formed in a plate shape, and the tip portion is in contact with the outer peripheral surface of the gravure roller 64. The processing liquid Lq is stored between the doctor blade 62 and the outer peripheral surface of the gravure roller 64. The doctor blade 62 is biased in the direction in which the tip portion presses the outer peripheral surface of the gravure roller 64, and has a function of adjusting the amount of the processing liquid Lq adhering to the outer peripheral surface of the gravure roller 64. The urging force for urging the doctor blade 62 may be the elastic force of the doctor blade 62 itself, or may be applied from the outside using an urging device such as a spring.

  On the outer peripheral surface of the gravure roller 64, a large number of precise cells carved in a pyramid shape or a lattice shape (pyramidal frustum shape) are formed at a predetermined density. The length of the gravure roller 64 in the axial direction is set to be equal to or longer than the length of the intermediate transfer roller 37 in the axial direction. The arrangement form of the cells on the surface of the gravure roller 64 is not particularly limited, but a form in which the cells are arranged along an oblique line that is not orthogonal to the rotation direction is preferable. The cell shape, depth, cell volume, density, and the like are appropriately selected according to the amount of liquid to be applied (the thickness of the liquid film after application). The gravure roller 64 is also called an anilox roller or a precision roller.

  In the coating device 60, when the gravure roller 64 rotates in the C3 direction (the same rotation direction as the intermediate transfer roller 37), among the processing liquid Lq stored between the gravure roller 64 and the doctor blade 62, between adjacent cells. Only the treatment liquid Lq held in the formed groove (not shown) passes between the tip of the doctor blade 62 and the outer peripheral surface of the gravure roller 64. The outer peripheral surface of the gravure roller 64 is in partial contact with the outer peripheral surface of the application roller 66, and the processing liquid Lq attached to the outer peripheral surface of the gravure roller 64 is transferred to the outer peripheral surface of the application roller 66 at the contact portion.

  The application roller 66 and the application range control roller 68 have the same configuration and functions as the application roller 54 and the application range control roller 56 (see FIG. 1 respectively) of the application device 50 according to the first embodiment described above. doing. That is, the application roller 66 applies the processing liquid Lq by rotating in the C2 direction, which is opposite to the intermediate transfer roller 37, in contact with the intermediate transfer roller 37. Further, although not shown in FIG. 3, the application range control roller 68 passes through the processing liquid whose ratio changes in accordance with the circumferential position on the outer peripheral surface, similarly to the application range control roller 56 of the first embodiment. The part 57a and the application | coating control part 57b (refer Fig.2 (a)-FIG.2 (c)) are formed.

  The application range control roller 68 is downstream of the contact portion between the gravure roller 64 and the application roller 66 and upstream of the contact portion between the application roller 66 and the intermediate transfer roller 37 with respect to the rotation direction (C2 direction) of the application roller 66. The processing liquid Lq adhering to the outer peripheral surface of the application roller 66 is partly scraped off by the application range control roller 68 before being applied to the intermediate transfer roller 37, and applied to the intermediate transfer roller 37. Range is controlled. In the first embodiment (see FIG. 1), the processing liquid Lq scraped off by the application range control roller 56 is dropped into the processing liquid container 52 and returned. In the embodiment, the processing liquid Lq scraped off by the application range control roller 68 is accumulated in the vicinity of the contact portion between the gravure roller 64 and the application roller 66.

  In the second embodiment, the application roller 66 and the application range control roller 68 (or the entire application device 60) are moved up and down with respect to the intermediate transfer roller 37, whereby the application roller 66 and the intermediate transfer roller 37 are moved. By contact or separation, the application range of the processing liquid Lq in the circumferential direction of the intermediate transfer roller 37 can be arbitrarily set.

  According to the second embodiment described above, the same effect as that of the first embodiment described above, that is, the application of the treatment liquid Lq applied to the surface of the intermediate transfer roller 37 according to the paper size of the paper to be printed. Since the range can be controlled (the processing liquid Lq is not applied to a range where the processing liquid Lq is not required to be applied), an effect of high efficiency can be obtained.

  The configuration described in each of the first and second embodiments is an example of the present invention, and the configuration can be changed as appropriate. For example, the application range control rollers 56 and 68 have a substantially cylindrical shape, that is, a cross section in a direction perpendicular to the rotation axis is formed in a circle. However, the present invention is not limited to this, and for example, there are many cross sections in a direction perpendicular to the rotation axis. It may be a square shape.

  In each of the above embodiments, the groove formed on the application range control roller 56 has a configuration in which the groove width continuously changes (the groove width gradually changes according to the position in the circumferential direction). For example, the groove width may be changed in a step shape (step shape). In the inkjet printers 100 and 200, a standard-size sheet is usually printed, and therefore there are no practical problems if several patterns are prepared in the range where the treatment liquid Lq is applied to the intermediate transfer roller 37.

  The heads 61BK, 61C, 61M, and 61Y are not limited to a method of ejecting liquid by applying pressure by a piezoelectric element. For example, a method of ejecting liquid by boiling of liquid by a heating unit, an electrostatic attraction by a voltage applying unit, or the like. Therefore, an ink jet head to which any method such as a method of discharging a liquid is applied can be used.

  In each of the above embodiments, the case where the image forming apparatus is a color printer has been described. However, the image forming apparatus is not limited to this, and may be a monochrome copying machine, a color copying machine, a facsimile apparatus, a plotter apparatus, or the like. Alternatively, a so-called MFP (Multi Function Printer) that combines these functions may be used.

  37 ... Intermediate transfer roller, 38 ... Transfer roller, 40 ... Cleaning device, 50 ... Application device, 52 ... Treatment liquid container, 54 ... Application roller, 56 ... Application range control roller, 57a ... Application agent passage part (groove), 57b ... Application restriction part, 58 ... Squeeze roller, 61BK to 61C ... Head, Lq ... Application agent, S ... Transfer paper.

JP 2002-321350 A JP 2000-24565 A Japanese Patent Laid-Open No. 9-314010

Claims (7)

An application device for applying an application agent to an application object,
Application that is provided so as to be rotatable around the first axis, and that applies the coating agent adhered to the outer peripheral surface by rotating around the first axis while being in contact with the application object. Laura,
An application agent supply device for supplying the application agent to the application roller;
A contact area that is provided so as to be rotatable about a second axis parallel to the first axis and that can contact an outer peripheral surface of the application roller on an outer peripheral surface, and the contact area is an outer periphery of the application roller An application range control member that forms a separation region that is separated from the outer peripheral surface in a state of being in contact with the surface, and that is in contact with the application roller that rotates in the direction around the first axis in a stopped state,
In the application range control member, the ratio of the contact area and the separation area in the direction parallel to the second axis changes according to the position around the second axis, and the position around the second axis A coating apparatus that controls the adhesion range of the coating agent in the first axial direction with respect to the coating roller by changing the angle. Further comprising a coating agent reservoir for storing the coating agent,
The said coating agent supply apparatus is a coating device of Claim 1 which supplies the said coating agent by immersing a part of said coating roller in a coating agent storage part.   The said coating agent supply apparatus has the supply roller by which the minute uneven | corrugated shape was formed in the surface, and the coating amount regulation member which contact | abuts to the said supply roller and quantifies the supply amount of the said coating agent. The coating apparatus as described in. The application roller is provided so as to be movable between a position in contact with the application object and a position in which the application roller is separated from the application object.
The coating apparatus according to any one of claims 1 to 3, wherein a coating range of the coating agent in a direction around the first axis with respect to the coating target is controlled by the contact and separation operations of the coating roller. The application range control member is provided with a groove extending in a direction around the second axis on the outer peripheral surface of the application range control member, whereby the separation region is formed,
The coating apparatus according to claim 1, wherein a groove width of the groove changes according to a position in a direction around the second axis.   The coating apparatus according to any one of claims 1 to 5, wherein the ratio between the contact area and the separation area changes continuously or discontinuously. A coating apparatus according to any one of claims 1 to 6,
An image forming unit for forming a recorded image on the coating object by supplying a recording agent onto the coating agent applied to the coating object;
An image forming apparatus comprising: a transfer device that transfers the recorded image formed on the application target to a predetermined recording medium.

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