JP2010173153A - Fluid jetting apparatus and fluid jetting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the deterioration of image quality caused by the ooze-out of fluids. <P>SOLUTION: A fluid jetting apparatus includes: a jetting part which performs jetting operations for jetting the fluid a plurality of times; and a transferring part having a sticking face on which the fluids are stuck and transferring the fluids on the sticking face to a medium. The transferring part transfers both the fluids to the medium while crushing both the fluids so as to bury a gap by pressing the sticking face on which both the fluids are stuck by being separated at the gap formed between both the fluids to the medium. Both the fluids are composed of one fluid jetted from the jetting part by one jetting operation among a plurality of times of the jetting operations, and another fluid jetted from the jetting part in the next jetting operation of the foregoing jetting operation. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fluid ejecting apparatus and a fluid ejecting method.

  BACKGROUND ART A fluid ejecting apparatus including an ejecting unit that ejects fluid is already known, such as an ink jet printer (hereinafter, a printer) that prints an image by performing an ejecting operation of ejecting ink a plurality of times. In addition, as a configuration of the fluid ejecting apparatus, a configuration including an attaching surface to which a fluid is attached and a transfer unit that transfers the fluid on the attached surface to a medium is also conceivable (for example, see Patent Document 1).

JP 2007-230232 A

  By the way, in the fluid ejecting apparatus, for example, when printing an image at a desired printing density, when the fluid ejected from the ejecting unit in each ejecting operation is adhered to the adhesion surface, the fluid is reduced while reducing the interval between the fluids. May adhere to the attachment surface. That is, both the fluid ejected in one of the plurality of ejecting operations and the fluid ejected in the next ejecting operation of the one ejecting operation are somewhat overlapped with each other. It may be adhered to the adhesion surface.

  However, in the above case, fluids overlap each other and the fluids tend to ooze. The fluid oozing may affect the image quality.

  The present invention has been made in view of such a problem, and an object of the present invention is to suppress image quality deterioration due to fluid oozing.

In order to solve the above problems, the main invention includes (A) an injection unit that performs an injection operation for injecting a fluid a plurality of times, and (B) an attachment surface that attaches the fluid, and the fluid on the attachment surface is a medium. A transfer unit that transfers to the fluid, the fluid ejected from the ejection unit in one of the plurality of ejection operations, and the ejection from the ejection unit in the ejection operation subsequent to the one ejection operation Transfer of both of the fluids transferred to the medium while pressing both the adhering surfaces adhering to each other with a gap formed between them against the medium while crushing both of them so that the gap is filled And a fluid ejection device characterized by comprising (C).
Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

1 is a block diagram illustrating a configuration of a printer. 2 is a diagram illustrating main components of the printer 1. FIG. 2 is a schematic side view of an ink image forming unit 20. FIG. 2 is a schematic plan view of an ink image forming unit 20. FIG. FIG. 4 is a diagram showing the arrangement of nozzles Nz on the nozzle surface 22. It is a figure which shows the flow of printing operation. 3 is a schematic diagram showing UV ink droplets attached to a peripheral surface 33 of a transfer drum 31. FIG. 3 is a diagram illustrating a state in which UV ink droplets on a circumferential surface 33 of a transfer drum 31 are transferred to a medium S. FIG. It is explanatory drawing about the bleeding of UV ink droplets. 4 is a schematic diagram showing UV ink transferred to a medium S. FIG. FIG. 10 is a diagram when the magnitude of the linear velocity v1 of the transfer drum 31 at the transfer position is smaller than the magnitude of the moving speed v2 of the medium S when passing through the transfer position. FIG. 6 is a diagram showing a modification of the transfer unit 30.

  At least the following will be made clear by the description of the present specification and the accompanying drawings.

  First, (A) an ejecting section that ejects a fluid a plurality of times, and (B) a transfer section that attaches the fluid to the medium and transfers the fluid on the adhered surface to the medium. Both of the fluid ejected from the ejection section in one ejection operation of the ejection operations and the fluid ejected from the ejection section in the next ejection operation of the one ejection operation are between the two. A fluid ejecting apparatus comprising: (C) a transfer unit that presses the adhering surface adhering across the gap formed on the medium to the medium while pressing both of the adhering surfaces to the medium so that the gap is filled; . With such a fluid ejecting apparatus, it is possible to suppress the interpenetration of fluids, thereby suppressing image quality deterioration.

  Further, in the fluid ejecting apparatus, the ejecting unit includes an irradiation unit that ejects an ultraviolet curable ink that is cured by receiving an ultraviolet ray, and irradiates the ultraviolet curable ink on the adhesion surface with the ultraviolet ray. The part is transferred to the medium while pressing both the adhering surfaces to which the both of which are in a semi-cured state by receiving the ultraviolet rays from the irradiation part adhere to the medium while crushing the both so that the gap is filled It is also good to do. With such a fluid ejecting apparatus, it is possible to reliably suppress the interpenetration of fluids while ensuring the print density of the image.

  In the fluid ejecting apparatus, the transfer unit includes a rotatable rotating body having a peripheral surface as the attachment surface, and presses the peripheral surface of the rotating rotating body against a medium. And a transfer unit that transfers the medium so that the medium passes through a transfer position where the transfer unit transfers the fluid on the peripheral surface to the medium. The linear velocity of the rotating body at the transfer position and the moving speed of the medium when passing through the transfer position may be different from each other. With such a fluid ejecting apparatus, the gap is easily filled during transfer.

  In the fluid ejecting apparatus, the rotating body rotates at the transfer position in the same direction as the medium travels through the transfer position, and the magnitude of the linear velocity is equal to the moving speed. It may be larger than the size. With such a fluid ejecting apparatus, the gap is more easily filled during transfer.

  Further, (A) performing the ejection operation of ejecting the fluid a plurality of times, and (B) attaching the fluid to the adhesion surface and then transferring the fluid on the adhesion surface to the medium a plurality of times. Both of the fluid ejected in one ejection operation of the operations and the fluid ejected in the next ejection operation of the one ejection operation adhere to each other with a gap formed therebetween. It is also possible to realize a fluid ejection method having (C) by pressing the attached surface against the medium to transfer the both onto the medium while crushing both of them so that the gap is filled. According to such a fluid ejecting method, it is possible to suppress image quality deterioration due to fluid oozing.

=== Outline of Fluid Ejecting Device of the Present Embodiment ===
In the present embodiment, an ink jet printer (hereinafter, printer 1) as an example of a fluid ejecting apparatus will be described. The printer 1 is a printing apparatus that prints an image on a medium S such as paper, cloth, or film sheet using ink as an example of a fluid. In particular, in this embodiment, ultraviolet curable ink (hereinafter, UV ink) that is cured by receiving ultraviolet rays is used. UV ink is an ink prepared by adding an auxiliary agent such as an antifoaming agent to a mixture of a vehicle containing a UV curable resin, a photopolymerization initiator, and a pigment. It hardens when a polymerization reaction occurs. Note that the printer 1 of this embodiment prints a color image using KCMY four-color UV ink.

<< Configuration of Printer 1 >>
As illustrated in FIG. 1, the printer 1 includes a controller 10, an ink image forming unit 20, a transfer unit 30 as an example of a transfer unit, a transport unit 40 as an example of a transport unit, and a fixing unit 50. . FIG. 1 is a block diagram illustrating a configuration of the printer 1.

  The controller 10 is a control device built in the printer 1, receives print data transmitted from the host computer 110 via the interface 11, and is executed by the CPU 12 via the unit control circuit 14 in accordance with a program stored in the memory 13. The units 20, 30, 40, and 50 are controlled. As a result, an image corresponding to the print data is printed on the medium S. The state in the printer 1 is monitored by the detector group 60, and the controller 10 controls each unit 20, 30, 40, 50 based on the detection result.

  The ink image forming unit 20 is an apparatus for forming an ink image on a peripheral surface 33 of a transfer drum 31 as an example of a rotating body. As shown in FIG. Is provided. That is, from the upstream side in the rotation direction of the transfer drum 31, a black ink image forming unit 20K that forms a black ink image, a cyan ink image forming unit 20C that forms a cyan ink image, and a magenta ink image forming unit that forms a magenta ink image. 20M, a yellow ink image forming unit 20Y for forming a yellow ink image is sequentially arranged. FIG. 2 is a diagram illustrating main components of the printer 1, and the vertical direction is indicated by an arrow in the drawing.

  The ink images formed by the ink image forming units 20K, 20C, 20M, and 20Y are superimposed on the peripheral surface 33 of the transfer drum 31, and transferred to the medium S as a transfer image by the transfer unit 30.

  Hereinafter, the configuration of the ink image forming unit 20 will be described with reference to FIGS. 3 and 4. FIG. 3 is a schematic side view of the ink image forming unit 20, and FIG. 4 is a schematic plan view of the ink image forming unit 20. Since the configuration of each ink image forming unit 20K, 20C, 20M, 20Y is the same, only the configuration of one ink image forming unit 20 will be described below.

  As shown in FIGS. 3 and 4, the ink image forming unit 20 includes a head 21 as an ejection unit and a semi-curing device 23 as an irradiation unit. The head 21 has a plurality of nozzles Nz formed on a surface (hereinafter referred to as a nozzle surface 22) on the side facing the peripheral surface 33 of the transfer drum 31. As shown in FIG. 5, the plurality of nozzles Nz form a nozzle row side by side at a fixed nozzle pitch along the axial direction of the transfer drum 31 on the nozzle surface 22 of the head 21. FIG. 5 is a diagram showing the arrangement of the nozzles Nz on the nozzle surface 22.

  The head 21 performs an ejection operation for ejecting UV ink from each nozzle Nz in a state where the nozzle surface 22 faces the peripheral surface 33 of the transfer drum 31. As a result, droplet-like UV ink (UV ink droplets) adheres (land) on the peripheral surface 33 of the transfer drum 31. When the UV ink droplets adhere to the peripheral surface 33 of the transfer drum 31, the UV ink droplet has a substantially hemispherical shape on the peripheral surface 33. In the present embodiment, a plurality of heads 21 are arranged in a staggered manner along the axial direction of the transfer drum 31 (see FIG. 4). The nozzles Nz face each other from one end to the other end of the circumferential surface 33 in the axial direction of the transfer drum 31. As a result, in one ejection operation, UV ink is ejected toward the range of the peripheral surface 33 from one end to the other end in the axial direction, and a plurality of UVs arranged in a row from the one end to the other end. Ink droplets (hereinafter also referred to as UV ink droplet groups) adhere to the peripheral surface 33 at a time.

  The semi-curing device 23 includes a light source 24 that emits ultraviolet rays such as a light emitting element (LED), which is located downstream of the head 21 in the rotation direction of the transfer drum 31. Then, the semi-curing device 23 irradiates UV ink droplets on the peripheral surface 33 with ultraviolet rays emitted from the light source 24. When the UV ink droplet passes directly under the semi-curing device 23 as the transfer drum 31 rotates, the UV ink droplet starts to be gradually cured by receiving ultraviolet rays.

  The irradiation intensity when the semi-irradiation device 26 irradiates ultraviolet rays is set so weak that the curing of the UV ink that has received the ultraviolet rays is contained in the vicinity of the surface thereof. For this reason, the UV ink droplets that have received ultraviolet rays from the semi-curing device 23 are in a semi-cured state (a state in which the vicinity of the surface is cured but the inside remains uncured and is not completely cured). Become. The UV ink droplet at the time when it is in a semi-cured state by receiving the ultraviolet rays from the semi-curing device 23 still has a substantially hemispherical shape.

  The ink image forming unit 20 having the above-described configuration repeats the UV ink ejection operation by the head 21 and the ultraviolet irradiation operation by the semi-curing device 23, thereby forming an ink image composed of semi-cured UV ink droplets. Are formed on the peripheral surface 33 of the transfer drum 31.

  The transfer unit 30 transfers UV ink droplets on the peripheral surface 33 of the transfer drum 31 (in other words, an ink image composed of UV ink droplets) to the medium S. As shown in FIG. 2, the transfer unit 30 includes the transfer drum 31 described above and a pressing roller 32. As described above, the transfer drum 31 includes the peripheral surface 33 as an attachment surface to which the UV ink is attached, and is rotatably supported. The transfer drum 31 always rotates in the rotation direction (the direction indicated by the arrow in FIG. 2) while the printer 1 performs the printing operation.

  The pressing roller 32 is disposed below the transfer drum 31 and presses the circumferential surface 33 against the medium S by pressing the medium S toward the circumferential surface 33 of the transfer drum 31. Specifically, the pressing roller 32 includes a peripheral surface 36 having substantially the same width as the peripheral surface 33 of the transfer drum 31, and cooperates with the transfer drum 31 between the transfer drum 31 and the pressing roller 32. The medium S to be conveyed is sandwiched. A pressing force from the pressing roller 32 acts on a portion of the medium S sandwiched between the transfer drum 31 and the pressing roller 32. At this time, UV ink droplets attached to a portion of the peripheral surface 33 of the transfer drum 31 that contacts the medium S (that is, a portion that sandwiches the medium S with the pressing roller 32) are transferred to the medium S. The

  As described above, the transfer unit 30 of the present embodiment uses the pressing roller 32 to press the peripheral surface 33 of the rotating transfer drum 31 against the medium S, thereby causing the UV ink droplets on the peripheral surface 33 to be removed. Transfer to medium S. In the present embodiment, as described above, before the UV ink droplet is transferred to the medium S, the UV ink droplet receives a UV ray from the semi-curing device 23 and becomes semi-cured. Therefore, the transfer unit 30 transfers the UV ink droplets on the peripheral surface 33 in a semi-cured state to the medium S.

  The transport unit 40 rotates while pinching the medium S so that the medium S fed into the printer 1 passes through the transfer position by a pair of transport rollers 41 (see FIG. 2) that transport the medium S. The medium S is conveyed, and the medium S that has passed through the transfer position is further conveyed toward the fixing unit 50. Here, the transfer position is a position where the transfer unit 30 transfers UV ink droplets on the peripheral surface 33 of the transfer drum 31 to the medium S in the transport path of the medium S. Specifically, the medium S is transferred. This position is sandwiched between the drum 31 and the pressing roller 32.

  In the present embodiment, the medium S is transported so that the direction in which the medium S passes through the transfer position is the same as the direction in which the transfer drum 31 rotates at the transfer position. In other words, the transfer drum 31 of this embodiment rotates at the transfer position in the same direction as the direction in which the medium S passes when passing through the transfer position.

  The fixing unit 50 includes a light source 51 such as a metal halide lamp, and irradiates UV ink (hereinafter also referred to as dots) transferred to the medium S with ultraviolet rays emitted from the light source 51, thereby transferring the dots. The image is fixed on the medium S. The irradiation intensity when the fixing unit 50 irradiates ultraviolet rays is stronger than the irradiation intensity when the semi-curing device 23 irradiates ultraviolet rays. When it receives ultraviolet rays from 50, it is in a fully cured state (a state where it has been completely cured to the inside).

  As the ultraviolet light sources 24 and 51 provided in each of the semi-curing device 23 and the fixing unit 50, in addition to the above-described metal halide lamp and light emitting element (LED), a xenon lamp, a carbon arc lamp, a chemical lamp, a low-pressure mercury lamp, A high-pressure mercury lamp can also be used.

<< Operation Example of Printer 1 >>
Next, a printing operation as an operation example of the printer 1 having the above configuration will be described. In the following, for easy understanding, monochrome printing, that is, only the black ink image forming unit 20K (hereinafter simply referred to as the ink image forming unit 20) of the KCMY four-color ink image forming units 20K, 20C, 20M, and 20Y. An example will be described in which is operated. A color image is printed if each of the KCMY four-color ink image forming units 20K, 20C, 20M, and 20Y operates according to a procedure described later.

  As shown in FIG. 6, the printing operation starts when the controller 10 receives print data from the host computer 110 (S001). FIG. 6 is a diagram showing the flow of the printing operation. Thereafter, the controller 10 analyzes the contents of various commands included in the print data and controls the units 20, 30, 40, and 50. Thereby, first, the transfer drum 31 rotates and the light sources 24 and 51 of the semi-curing device 23 and the fixing unit 50 are turned on (S002). In such a state, the medium S is fed into the printer 1.

  While the transfer drum 31 is rotating, each of the plurality of heads 21 arranged in a zigzag pattern along the axial direction of the transfer drum 31 causes the nozzle surface 22 to face the peripheral surface 33 of the transfer drum 31. The ejection operation for ejecting UV ink toward the peripheral surface 33 is intermittently performed a plurality of times (S003). As a result, the above-described UV ink droplet group adheres to the circumferential surface 33 at regular intervals along the circumferential direction of the circumferential surface 33 (that is, the rotation direction of the transfer drum 31). That is, an ink image composed of UV ink droplet groups is gradually formed on the peripheral surface 33.

  Here, the interval between the UV ink droplet groups is the interval between the UV ink droplets in the circumferential direction (the distance between the centers of the UV ink droplets). Further, the diameter of the UV ink droplet is smaller than the interval between the UV ink droplets. Therefore, as shown in FIG. 7, a gap 34 is formed between the UV ink droplets adjacent in the circumferential direction. FIG. 7 is a schematic diagram showing UV ink droplets attached to the peripheral surface 33 of the transfer drum 31.

  As described above, when the UV ink droplets ejected from the head 21 are adhered to the peripheral surface 33 of the transfer drum 31 along the circumferential direction of the peripheral surface 33, the gap 34 is interposed between the UV ink droplets. The UV ink droplets are adhered to the peripheral surface 33 so as to form the above. In other words, the UV ink droplets ejected from the head 21 in one ejection operation among a plurality of ejection operations (for example, the nth UV ink droplet in FIG. 7), and the next of the one ejection operation. Both of the UV ink droplets ejected from the head 21 in the ejection operation (n + 1th UV ink droplet in FIG. 7) are attached to the peripheral surface 33 with a gap 34 formed therebetween. Become.

  The size of the gap 34 in the circumferential direction depends on parameters such as the interval of the ejection operation (that is, the UV ink ejection interval) and the peripheral speed of the transfer drum 31, and these parameters are related to the unit control circuit 14. It can be controlled by the controller 10 via

  As the transfer drum 31 rotates, the UV ink droplets adhering to the peripheral surface 33 pass directly under the semi-curing device 23 in the rotation direction of the transfer drum 31. At such a position, the UV ink droplet is subjected to ultraviolet rays from the semi-curing device 23 and becomes semi-cured (S004). Thereafter, the UV ink droplets on the peripheral surface 33 in a semi-cured state move to the downstream side in the rotation direction by further rotation of the transfer drum 31, and eventually, between the transfer drum 31 and the pressing roller 32. Will come. On the other hand, when transferring the UV ink droplet on the peripheral surface 33 to the medium S, the transport unit 40 transports the medium S toward the transfer position. That is, the transport unit 40 transports the medium S so that the medium S passes through the transfer position.

  Then, the medium S moves while being sandwiched between the transfer drum 31 and the pressing roller 32. At this time, the transfer unit 30 presses the peripheral surface 33 of the rotating transfer drum 31 against the medium S, and transfers the UV ink droplets on the peripheral surface 33 in a semi-cured state to the medium S (S005). When the peripheral surface 33 of the transfer drum 31 is pressed against the medium S, the transfer unit 30 of the present embodiment transfers the UV ink droplets on the peripheral surface 33 in a semi-cured state to the medium S while crushing. As a result, as shown in FIG. 8, the UV ink droplets that have been in the shape of a substantially hemisphere so far extend along the circumferential direction of the peripheral surface 33 (in other words, the rotational direction of the transfer drum 31) and become flat. Deform. As a result, the gap 34 formed between the UV ink droplets is filled by the deformation of the UV ink droplets. FIG. 8 is a diagram illustrating a state in which UV ink droplets on the circumferential surface 33 of the transfer drum 31 are transferred to the medium S.

  As described above, in the present embodiment, both the UV ink droplet ejected in one ejection operation and the UV ink droplet ejected in the next ejection operation of the one ejection operation are half on the circumferential surface 33. After receiving the ultraviolet rays from the curing device 23 and becoming a semi-cured state, the transfer unit 30 presses the circumferential surface 33 to which both of the semi-cured states are attached to the medium S. Then, the transfer unit 30 transfers the both onto the medium S while crushing both so that the gap 34 is filled.

  Furthermore, in the present embodiment, the linear velocity of the transfer drum 31 at the transfer position (that is, the peripheral speed of the transfer drum 31 and indicated by the symbol v1 in FIG. 8) and the medium S when passing through the transfer position. The movement speed (that is, the conveyance speed, indicated by the symbol v2 in FIG. 8) is different from each other. More specifically, the transfer drum 31 is rotated at the transfer position in the same direction as the direction of the medium S when passing through the transfer position, and the magnitude of the linear velocity v1 is equal to the moving velocity v2. It is larger than the size. Accordingly, the deformation of the UV ink droplets is promoted, and the interval between the UV inks transferred to the medium S (specifically, the dot pitch in the transport direction of the medium S, which is indicated by the symbol d in FIG. 8). The distance between the UV ink droplets on the peripheral surface 33 of the transfer drum 31 (indicated by symbol l in FIG. 8) is shorter. As a result, when the UV ink droplet on the peripheral surface 33 of the transfer drum 31 is transferred to the medium S, the gap 34 is more easily filled.

  Thereafter, the portion of the medium S that has passed the transfer position is transported toward the fixing unit 50 by the transport unit 40. Then, when the UV ink transferred to the medium S, that is, the dot, receives ultraviolet rays from the fixing unit 50, the dot transits from the semi-cured state to the fully cured state. As a result, the transfer image composed of dots is fixed on the medium S as a final image (S006).

  The medium S on which the image is printed by the above steps is discharged out of the printer 1 by a paper discharge mechanism (not shown) (S007). Since the image printed by the above procedure is composed of a plurality of dots arranged with the gap 34 filled, it is an image printed at a desired print density. This will be described in detail in the next section.

=== Effectiveness of Printer 1 of this Embodiment ===
The printer 1 of this embodiment has the transfer unit 30 as described above. The transfer unit 30 then ejects the UV ink droplets (an example of fluid) ejected from the head 21 in one ejection operation among a plurality of ejection operations, and the head 21 in the ejection operation subsequent to the one ejection operation. By pressing the peripheral surface 33 (an example of the adhering surface) of the transfer drum 31 to which both of the UV ink droplets ejected from the adhering with the gap 34 formed between the two are pressed against the medium S, Both are transferred to the medium S while being crushed so that the gap 34 is filled.

  In other words, the UV ink ejecting method (an example of a fluid ejecting method) employed by the printer 1 of the present embodiment performs the ejecting operation of ejecting UV ink a plurality of times, and the UV ink is applied to the peripheral surface 33 of the transfer drum 31. When the UV ink on the peripheral surface 33 is transferred to the medium S after the droplets are attached, the UV ink droplets ejected in the one ejection operation and the ejection operation subsequent to the one ejection operation Both of the ejected UV ink droplets are pressed against the medium S against the medium surface S with the gap 34 formed between the two, and the both are crushed so that the gap 34 is filled. And transferring to the medium S.

  As a result of the above, in this embodiment, it is possible to suppress the blurring between the UV inks, thereby suppressing the image quality deterioration of the image.

  More specifically, as described in the section of the problem to be solved by the invention, when printing an image at a desired printing density, the UV ink droplets ejected from the head 21 in each ejection operation are transferred to the transfer drum 31. When adhering to the peripheral surface 33, the interval between the UV ink droplets may be reduced. That is, the UV ink droplet ejected in one ejection operation and the UV ink droplet ejected in the next ejection operation of the one ejection operation are attached to the peripheral surface 33 in a state of being separated from each other. The interval between the UV ink droplets is increased, and there is a possibility that the density when the image is actually printed does not become a desired printing density. For this reason, the UV ink droplets are attached to the peripheral surface 33 while the intervals between the UV ink droplets are reduced as described above.

  However, if the interval between the UV ink droplets is reduced, the UV ink droplets tend to ooze as shown in FIG. FIG. 9 is an explanatory diagram of the bleeding between UV ink droplets. Such bleeding between the UV ink droplets causes deterioration in image quality. In particular, when UV ink droplets having different colors ooze during color printing, image quality deterioration becomes more noticeable due to color mixing.

  Therefore, in the present embodiment, as described above, both the UV ink droplets ejected in one ejection operation and the UV ink droplets ejected in the next ejection operation of the one ejection operation are both It adheres to the said surrounding surface 33, providing the clearance gap 34 in between (refer FIG. 8). That is, since the UV ink droplets at the stage of adhering to the peripheral surface 33 are separated from each other, the oozing of the UV ink droplets on the peripheral surface 33 is suppressed.

  In this embodiment, thereafter, the UV ink droplets on the peripheral surface 33 are irradiated with ultraviolet rays to make the UV ink droplets semi-cured. Since the UV ink droplets in a semi-cured state are difficult to bleed, even if the UV ink drips come close to each other thereafter, the oozing between the UV ink droplets is suppressed. In this state, the UV ink droplet is transferred to the medium S while being crushed so that the gap 34 is filled. As a result, in the medium S to which the UV ink is transferred, the gap 34 is filled as shown in FIG. 10, and the density at the time of actually printing an image also becomes a desired printing density. FIG. 10 is a schematic diagram showing the UV ink transferred to the medium S. As shown in FIG.

  As described above, according to the present embodiment, it is possible to suppress the blurring between the UV inks while ensuring the printing density, thereby suppressing the deterioration of the image quality of the image. With the printer 1 according to the present embodiment, even when KCMY four-color printing is performed, it is possible to appropriately print a color image while suppressing color mixing due to bleeding between UV inks.

  In this embodiment, the linear velocity v1 of the transfer drum 31 at the transfer position is different from the moving velocity v2 of the medium S when passing through the transfer position. In particular, in the present embodiment, the linear velocity v1 is larger than the moving velocity v2. As described above, if there is a speed difference between the two speeds v1 and v2, the UV ink droplet on the peripheral surface 33 is dragged to the transfer drum 31 at the time of transfer and is urged to be deformed. Furthermore, if the relationship between the two speeds v1 and v2 is the above relationship, the interval d between the UV inks transferred to the medium S is the interval l between the UV ink droplets on the peripheral surface 33 of the transfer drum 31. (See FIG. 8). As a result, when the UV ink droplet on the peripheral surface 33 is transferred to the medium S, the gap 34 is easily filled.

  However, it is not limited to the case where the magnitude of the linear velocity v1 is larger than the magnitude of the moving speed v2, and the magnitude of the linear velocity v1 may be smaller than the magnitude of the moving speed v2. . In this case, as shown in FIG. 11, although the interval d between the UV inks transferred to the medium S is longer than the interval l between the UV ink droplets on the peripheral surface 33 of the transfer drum 31, Since there is a speed difference between the speeds v1 and v2, it is possible to promote the deformation of the UV ink droplets. FIG. 11 is a view corresponding to FIG. 8 in the case where the magnitude of the linear velocity v1 of the transfer drum 31 at the transfer position is smaller than the magnitude of the moving speed v2 of the medium S when passing through the transfer position. is there.

  As described above, as long as the magnitude of the linear velocity v1 and the magnitude of the moving velocity v2 are different, the magnitude relationship between the two velocities v1 and v2 does not matter, but the gap 34 between the UV ink droplets is transferred. It is desirable that the magnitude of the linear velocity v1 is larger than the magnitude of the moving velocity v2 in that it is sometimes filled efficiently. On the other hand, in order to increase the printing speed by increasing the moving speed v2 of the medium S, the moving speed v2 is larger than the linear speed v1 (the linear speed v1 is larger than the moving speed). It is preferable to be smaller than the speed v2.

=== Other Embodiments ===
The fluid ejection device and the fluid ejection method according to the present invention have been described above based on the above embodiment. However, the embodiments of the invention described above are for facilitating the understanding of the present invention, and do not limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof.

  In the above embodiment, each of the plurality of heads 21 arranged in a staggered manner along the axial direction of the transfer drum 31 ejects UV ink, so that the UV ink droplets arranged in a line along the axial direction. The (UV ink droplet group) was allowed to adhere to the peripheral surface 33 of the transfer drum 31. However, the present invention is not limited to this, and one long head 21 may be provided for each ink image forming unit 20 instead of the plurality of heads 21. In the above embodiment, the UV ink is ejected in a state where each head 21 is fixed at a predetermined position. However, the head 21 ejects UV ink while moving along the axial direction of the transfer drum 31 ( That is, the printer 1 may be a serial type).

  In the above embodiment, the transfer unit 30 includes the transfer drum 31 as a rotating body. However, the above rotating body is not limited to the transfer drum 31 and may be a rotatable endless transfer belt, for example.

  In the above embodiment, the transfer unit 30 having only one transfer drum 31, that is, the transfer unit 30 that performs single-stage transfer has been described as an example. However, the transfer unit 30 is not limited to this, and may be a transfer unit 30 that performs multi-stage transfer as shown in FIG. FIG. 12 is a diagram illustrating a modified example of the transfer unit 30.

  A transfer unit 30 according to a modification will be described with reference to FIG. The transfer unit 30 according to the modified example includes a first transfer drum 35 and a second transfer drum 37. The first transfer drum 35 rotates with its peripheral surface 36 facing the nozzle surface 22 of the head 21, and receives the UV ink droplets ejected from the head 21 at the peripheral surface 36. The UV ink droplets adhering to the peripheral surface 36 of the first transfer drum 35 pass directly under the semi-curing device 23 disposed so as to face the peripheral surface 36 as the first transfer drum 35 rotates. To do. At this time, the UV ink droplets on the peripheral surface 36 are in a semi-cured state upon receiving ultraviolet rays.

  The second transfer drum 37 is a rotating body according to the modified example, and rotates while the peripheral surface 38 (corresponding to the peripheral surface according to the modified example) is rubbed against the peripheral surface 36 of the first transfer drum 35. . Then, while the second transfer drum 37 is rotating, the UV ink droplets on the peripheral surface 36 of the first transfer drum 35 that is in a semi-cured state are moved to the peripheral surface 38 side of the second transfer drum 37. To adhere to the peripheral surface 38 (transferred). At this time, since the UV ink droplets adhering to the peripheral surface 38 of the second transfer drum 37 are intermittently arranged along the circumferential direction of the peripheral surface 38, the above-described gap 34 is formed between the UV ink droplets. Will be formed.

  Then, the transfer unit 30 according to the modified example presses the peripheral surface 38 of the second transfer drum 37 on which the UV ink droplets are attached with the gap 34 therebetween, against the medium S, so that The UV ink droplet is transferred to the medium S while being crushed so that the gap 34 is filled.

  As described above, the modified example is different from the above-described embodiment in that multi-stage transfer is performed, but other than that, it is the same as the above-described embodiment and has the same effects as the above-described embodiment.

  In the above embodiment, the printer 1 that ejects UV ink as an example of the fluid has been described as an example. However, the present invention is not limited to this. As long as the surface is dry (cured) from the time it adheres to the adhesion surface until it is transferred to the medium, it can be crushed in such a state. Or a liquid material in which particles of functional material are dispersed, or a liquid material such as a gel). In the case of such a fluid ejecting apparatus that ejects fluid, for example, a material such as an electrode material or a color material used for manufacturing a liquid crystal display, an EL (electroluminescence) display, and a surface emitting display is dispersed or dissolved. It may be a fluid ejecting apparatus that ejects a liquid to be contained, a fluid ejecting apparatus that ejects a bio-organic material used in biochip manufacturing, or a fluid ejecting apparatus that ejects a liquid that is used as a precision pipette and serves as a sample. In addition, transparent resin liquids such as UV curable resins to form fluid injection devices that inject lubricating oil onto precision machines such as watches and cameras, micro hemispherical lenses (optical lenses) used in optical communication elements, etc. May be a fluid ejecting apparatus that ejects a liquid onto the substrate, a fluid ejecting apparatus that ejects an etching solution such as acid or alkali to etch the substrate, and a fluid ejecting apparatus that ejects a gel. The present invention can be applied to any of the above fluid ejecting apparatuses.

1 printer, 10 controller, 11 interface, 12 CPU, 13 memory, 14 unit control circuit, 20 ink image forming unit, 20K black ink image forming unit, 20C cyan ink image forming unit, 20M magenta ink image forming unit, 20Y yellow ink Image forming unit, 21 head, 22 nozzle surface, 23 semi-curing device, 24 light source, 30 transfer unit, 31 transfer drum, 32 pressing roller, 33 circumferential surface, 34 gap, 35 first transfer drum, 36 circumferential surface, 37 Second transfer drum, 38 peripheral surface, 40 transport unit, 41 transport roller, 50 fixing unit, 51 light source, 60 detector group, 110 host computer, S medium

Claims (5)

An injection unit that performs an injection operation of injecting a fluid multiple times;
A transfer unit comprising an attachment surface for adhering a fluid, and transferring the fluid on the attachment surface to a medium,
Both of the fluid ejected from the ejection unit in one ejection operation of the plurality of ejection operations and the fluid ejected from the ejection unit in the ejection operation subsequent to the one ejection operation A transfer unit that transfers the image to the medium while pressing the adhesive surface that is attached across the gap formed between the medium and the medium while pressing the adhesive surface so that the gap is filled;
A fluid ejecting apparatus comprising: The fluid ejection device according to claim 1,
The ejection unit ejects ultraviolet curable ink that is cured by receiving ultraviolet rays,
An irradiation part for irradiating ultraviolet rays to the ultraviolet curable ink on the adhesion surface;
The transfer unit receives the ultraviolet rays from the irradiation unit and presses the attached surface to which both of them are attached to the medium while pressing the both sides so that the gap is filled. A fluid ejecting apparatus, wherein In the fluid ejection device according to claim 1 or 2,
The transfer unit has a rotatable rotating body having a peripheral surface as the attachment surface, and presses the peripheral surface of the rotating rotating body against a medium, thereby allowing fluid on the peripheral surface to flow. Transferred to the medium,
A transfer unit for transferring the medium so that the medium passes through a transfer position at which the transfer unit transfers the fluid on the peripheral surface to the medium;
The fluid ejecting apparatus according to claim 1, wherein a linear velocity of the rotating body at the transfer position is different from a moving speed of the medium when passing through the transfer position. The fluid ejection device according to claim 3, wherein
The rotating body rotates at the transfer position in the same direction as the direction in which the medium passes through the transfer position;
The fluid ejecting apparatus according to claim 1, wherein the linear velocity is larger than the moving velocity. Performing a plurality of ejection operations for ejecting the fluid;
When the fluid is attached to the attachment surface and then the fluid on the attachment surface is transferred to the medium,
Both the fluid ejected in one ejection operation of the plurality of ejection operations and the fluid ejected in the next ejection operation of the one ejection operation have a gap formed between the two. By pressing the attachment surface that is attached at a distance against the medium, transferring both to the medium while squeezing the gap so that the gap is filled;
A fluid ejection method comprising: