Recording device and recording method

Abstract

To suppress a radical generated by irradiating a surface of a recording target medium with coronae from a corona irradiation part to stick on a discharge part and react with ink to cause a defect in discharging of the ink.SOLUTION: A recording device 1 comprises carrier parts 106 and 113, a corona irradiation part 201, a discharge part 110, and a control part 120, and changes irradiation intensity of the corona irradiation part 201 according to discharge density of white ink when forming a colored image on a background image with colored ink after forming the background image on a recording target medium M with the white ink.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a recording apparatus and a recording method. [Background technology]

[0002] Conventionally, various recording devices have been used that perform recording by ejecting ink from an ejection unit onto a recording medium. For example, Patent Document 1 discloses a printing device that includes a corona treatment device that modifies the surface of the recording medium by irradiating the surface with a corona, and that forms an image by ejecting ink from an ejection head onto a roll-shaped recording medium. Patent Document 1 describes that ink mist adheres to the ejection head due to the recording medium being electrically charged. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-196745 Summary of the Invention [Problem to be solved by the invention]

[0004] As a result of extensive research, the inventors have found that in conventional recording devices, such as the printing device described in Patent Document 1, which includes a corona irradiation unit that modifies the surface of a recording medium by irradiating the surface with a corona, radicals are present on the surface of the recording medium as a result of the corona irradiation, and the radicals on the surface of the recording medium also cause radicals to be present in the ejection unit due to the influence of the radicals on the surface of the recording medium. Furthermore, they have found that if radicals are present in the ejection unit, they react with the ink mist to form solidified matter, which can then adhere to the ink ejection orifices and cause ejection defects. While the printing device described in Patent Document 1 is equipped with an ionizer that can neutralize the surface of the recording medium using the ionizer, there are cases where the surface of the recording medium cannot be completely neutralized, and in such cases, ejection defects may occur. [Means for solving the problem]

[0005] In order to solve the above problem, the recording device of the present invention includes a transport unit that transports a recording medium, a corona irradiation unit that is arranged on a transport path of the recording medium and that irradiates the surface of the recording medium with a corona to modify the surface, a discharge unit that is arranged on the transport path downstream of the corona irradiation unit and that discharges ink onto the recording medium, and a control unit that controls the driving of the transport unit, the corona irradiation unit, and the discharge unit, wherein the discharge unit has a first head that discharges white ink as the ink to form a background image, and a second head that is arranged on the transport path downstream of the first head and that discharges colored inks to form a colored image, and the control unit is characterized in that when the background image is formed on the recording medium with the white ink and then the colored image is formed on the background image with the colored ink, the control unit changes the irradiation intensity of the corona irradiation unit depending on the discharge density of the white ink.

[0006] Another recording device of the present invention for solving the above problem includes a transport unit that transports a recording medium, a corona irradiation unit that is arranged on a transport path of the recording medium and that modifies the surface of the recording medium by irradiating the surface with a corona, a discharge unit that is arranged downstream of the corona irradiation unit on the transport path and that discharges ink onto the recording medium, and a control unit that controls the driving of the transport unit, the corona irradiation unit, and the discharge unit, wherein the discharge unit has a first head that discharges white ink as the ink to form a background image, and a second head that is arranged downstream of the first head on the transport path and that discharges colored inks to form colored images, and the control unit is characterized in that when the recording medium is a registered recording medium that has been registered in advance and the recording data does not include data to form the background image with the white ink, the control unit automatically adds data to the recording data to form the background image with the white ink.

[0007] Furthermore, the present invention provides a recording method for solving the above-mentioned problems, which can be performed using a recording device comprising: a transport unit that transports a recording medium; a corona irradiation unit that is arranged on a transport path of the recording medium and that modifies the surface of the recording medium by irradiating the surface with a corona; and a discharge unit that is arranged on the transport path downstream of the corona irradiation unit and that discharges ink onto the recording medium, wherein the discharge unit has a first head that discharges white ink to form a background image as the ink; and a second head that is arranged on the transport path downstream of the first head and that discharges colored inks to form a colored image, wherein the recording method is characterized in that when the background image is formed on the recording medium with the white ink and then the colored image is formed on the background image with the colored ink, the irradiation intensity of the corona irradiation unit is changed depending on the discharge density of the white ink. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of a recording apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing the electrical configuration of the recording apparatus shown in FIG. [Figure 3] 2 is a flowchart of a recording method according to an embodiment, which is performed using the recording device of FIG. 1. [Figure 4] 10 is a graph showing the relationship between the discharge density and the irradiation intensity of the corona irradiation unit. DETAILED DESCRIPTION OF THE INVENTION

[0009] First, the present invention will be briefly described. In order to solve the above problem, a recording device of a first aspect of the present invention includes a transport unit that transports a recording medium, a corona irradiation unit that is arranged on a transport path of the recording medium and that irradiates the surface of the recording medium with a corona to modify the surface, a discharge unit that is arranged on the transport path downstream of the corona irradiation unit and that discharges ink onto the recording medium, and a control unit that controls the driving of the transport unit, the corona irradiation unit, and the discharge unit, wherein the discharge unit has a first head that discharges white ink as the ink to form a background image, and a second head that is arranged on the transport path downstream of the first head and that discharges colored inks to form a colored image, and the control unit is characterized in that when forming the background image on the recording medium with the white ink and then forming the colored image on the background image with the colored ink, the control unit changes the irradiation intensity of the corona irradiation unit depending on the discharge density of the white ink.

[0010] According to this aspect, when a background image is formed on a recording medium with white ink and then a colored image is formed on the background image with colored inks, the irradiation intensity of the corona irradiation unit is changed according to the ejection density of the white ink. As a result of extensive research by the present inventors, it was found that when a background image is formed on a recording medium with white ink and then a colored image is formed on the background image with colored inks, the amount of radicals present on the surface of the recording medium is reduced by corona irradiation, making ejection defects less likely to occur. Therefore, when a background image is formed on a recording medium with white ink and then a colored image is formed on the background image with colored inks, the occurrence of ink ejection defects can be effectively suppressed by changing the irradiation intensity of the corona irradiation unit according to the ejection density of the white ink.

[0011] A recording device of a second aspect of the present invention is characterized in that, in the first aspect, when forming the background image on the recording medium with the white ink and then forming the colored image on the background image with the colored inks, the control unit changes the irradiation intensity of the corona irradiation unit in accordance with the ejection density of the white ink, only if the recording medium is a previously registered recording medium.

[0012] As a result of extensive research by the inventors, it was found that the amount of radicals present on the surface of the recording medium due to corona irradiation varies depending on the type of recording medium. According to this aspect, only when the recording medium is a registered recording medium, when a background image is formed on the recording medium with white ink and then a colored image is formed on the background image with colored inks, the irradiation intensity of the corona irradiation unit is changed according to the ejection density of the white ink. Therefore, when using a recording medium that does not fall under the category of a registered recording medium and is less likely to cause ink ejection defects, it is possible to prevent the recording control from becoming complicated.

[0013] A recording device according to a third aspect of the present invention is the recording device according to the second aspect, characterized in that the registered recording medium contains resin as a material.

[0014] According to this aspect, the registered recording medium contains a resin as a material. A recording medium containing a resin as a material is prone to causing ink ejection defects due to the increased amount of radicals present on the surface when irradiated with a corona, but even when a recording medium containing a resin as a material is used, the occurrence of ink ejection defects can be effectively suppressed.

[0015] A fourth aspect of the recording device of the present invention is characterized in that, in any one of the first to third aspects, when forming the colored image on the recording medium with the colored inks without forming the background image on the recording medium with the white ink, the control unit changes the irradiation intensity of the corona irradiation unit so that the irradiation intensity is 20% or less of the maximum irradiation intensity of the corona irradiation unit when forming the background image on the recording medium with the white ink and then forming the colored image on the background image with the colored inks.

[0016] According to this aspect, when a colored image is formed on a recording medium using colored inks without forming a background image on the recording medium using white ink, the irradiation intensity of the corona irradiation unit is changed so that it is 20% or less of the maximum irradiation intensity of the corona irradiation unit when a background image is formed on a recording medium using white ink and then a colored image is formed on the background image using colored inks. In this way, when a colored image is formed on a recording medium using colored inks without forming a background image on the recording medium using white ink, which is prone to ink ejection defects, the occurrence of ink ejection defects can be effectively suppressed by reducing the irradiation intensity of the corona irradiation unit.

[0017] A fifth aspect of the recording device of the present invention is characterized in that, in any one of the first to third aspects, it is provided with a gap adjustment unit that adjusts the gap between the ejection unit and the recording medium, and the control unit controls the gap adjustment unit to widen the gap when forming the colored image on the recording medium with the colored inks without forming the background image on the recording medium with the white ink, compared to the gap when forming the background image on the recording medium with the white ink and then forming the colored image on the background image with the colored inks.

[0018] According to this aspect, the gap adjustment unit is controlled to widen the gap when a colored image is formed on a recording medium with colored inks without forming a background image on the recording medium with white ink, compared to the gap when a background image is formed on a recording medium with white ink and then a colored image is formed on the background image with colored inks. Widening the gap makes it difficult for radicals to adhere to the ejection unit. Therefore, even when a colored image is formed on a recording medium with colored inks without forming a background image on the recording medium with white ink, in which case many radicals are likely to be generated on the surface of the recording medium, the occurrence of ink ejection defects can be effectively suppressed.

[0019] A sixth aspect of the recording device of the present invention is characterized in that, in any one of the first to third aspects, it is provided with a maintenance unit that maintains the ejection unit, and the control unit controls the maintenance unit to make the maintenance interval by the maintenance unit when forming the colored image on the recording medium with the colored inks without forming the background image on the recording medium with the white ink shorter than the maintenance interval by the maintenance unit when forming the background image on the recording medium with the white ink and then forming the colored image on the background image with the colored inks.

[0020] According to this aspect, the maintenance interval by the maintenance unit when forming a colored image on a recording medium with colored inks without forming a background image on the recording medium with white ink is set shorter than the maintenance interval by the maintenance unit when forming a background image on a recording medium with white ink and then forming a colored image on the background image with colored inks. By shortening the maintenance interval, radicals are less likely to remain in the ejection unit. Therefore, even in this case where a colored image is formed on a recording medium with colored inks without forming a background image on the recording medium with white ink, in which case a large number of radicals are likely to be generated on the surface of the recording medium, the occurrence of ink ejection defects can be effectively suppressed.

[0021] A recording device according to a seventh aspect of the present invention comprises a transport unit that transports a recording medium, a corona irradiation unit that is arranged on a transport path of the recording medium and that modifies the surface of the recording medium by irradiating the surface with a corona, an ejection unit that is arranged downstream of the corona irradiation unit on the transport path and that ejects ink onto the recording medium, and a control unit that controls the driving of the transport unit, the corona irradiation unit, and the ejection unit, wherein the ejection unit has a first head that ejects white ink as the ink to form a background image, and a second head that is arranged downstream of the first head on the transport path and that ejects colored inks to form colored images, and the control unit is characterized in that, when the recording medium is a registered recording medium that has been registered in advance and the recording data does not include data to form the background image with the white ink, the control unit automatically adds data to the recording data to form the background image with the white ink.

[0022] According to this aspect, if the recording medium is a previously registered recording medium and the recording data does not include data for forming a background image with white ink, data for forming a background image with white ink is automatically added to the recording data. Therefore, by registering a recording medium that has a large amount of radicals present on its surface due to corona irradiation as a previously registered recording medium, it is possible to prevent a background image from being formed with white ink and an increase in radicals on the surface of the recording medium, and effectively prevent the occurrence of ink ejection defects.

[0023] An eighth aspect of the recording device of the present invention is the seventh aspect, and has a first recording mode and a second recording mode as recording modes, and in the first recording mode, if the recording medium is a registered recording medium that has been registered in advance and the recording data does not include data for forming the background image with the white ink, the control unit automatically adds data for forming the background image with the white ink to the recording data, and in the second recording mode, if the recording medium is a registered recording medium that has been registered in advance and the recording data does not include data for forming the background image with the white ink, the control unit does not add data for forming the background image with the white ink to the recording data.

[0024] According to this aspect, in addition to the first recording mode, there is a second recording mode in which data for forming a background image with white ink is not added to the recording data even when the recording medium is a pre-registered recording medium and the recording data does not include data for forming a background image with white ink. Therefore, if the user does not want to form a background image, a colored image can be formed without forming a background image.

[0025] A ninth aspect of the recording device of the present invention is characterized in that, in the seventh or eighth aspect, the control unit does not add data to form the background image with white ink to the recording data when the recording medium is a registered recording medium that has been registered in advance and the recording data includes data to form the background image with white ink.

[0026] According to this aspect, when the recording medium is a registered recording medium that has been registered in advance and the recording data includes data for forming a background image with white ink, data for forming a background image with white ink is not added to the recording data. Therefore, when the recording data includes data for forming a background image with white ink, it is possible to prevent the recording process from becoming more complicated by adding further data for forming a background image with white ink.

[0027] A tenth aspect of the recording device of the present invention is characterized in that, in any one of the seventh to ninth aspects, when the recording medium is a registered recording medium that has been registered in advance and the recording data does not include data for forming the background image with the white ink, the control unit changes the irradiation intensity of the corona irradiation unit in accordance with the ejection density of the white ink when automatically adding data for forming the background image with the white ink to the recording data.

[0028] According to this aspect, when the recording medium is a registered recording medium that has been registered in advance and the recording data does not include data for forming a background image with white ink, when data for forming a background image with white ink is automatically added to the recording data, the irradiation intensity of the corona irradiation unit is changed according to the ejection density of the white ink. The higher the ejection density of the white ink, the less radicals there are on the recording medium. By changing the irradiation intensity of the corona irradiation unit in accordance with this tendency, it is possible to effectively suppress the occurrence of ink ejection defects.

[0029] A recording method according to an eleventh aspect of the present invention is a recording method that can be performed using a recording device comprising: a transport unit that transports a recording medium; a corona irradiation unit that is arranged on a transport path of the recording medium and that modifies the surface of the recording medium by irradiating the surface with a corona; and a discharge unit that is arranged on the transport path downstream of the corona irradiation unit and that discharges ink onto the recording medium, wherein the discharge unit has a first head that discharges white ink to form a background image as the ink; and a second head that is arranged on the transport path downstream of the first head and that discharges colored inks to form a colored image, wherein when the background image is formed on the recording medium with the white ink and then the colored image is formed on the background image with the colored ink, the irradiation intensity of the corona irradiation unit is changed depending on the discharge density of the white ink.

[0030] According to this aspect, when a background image is formed on a recording medium using white ink and then a colored image is formed on the background image using colored inks, the irradiation intensity of the corona irradiation unit is changed according to the ejection density of the white ink, thereby effectively preventing ink ejection failures.

[0031] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. First, an overview of a recording device 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. The recording device 1 of this embodiment is a recording device that forms an image on a recording medium M such as paper, cloth, or film, and is communicably connected to a PC 2 as shown in FIG. 2. Note that the recording device 1 of this embodiment is configured to be able to record on a recording medium M wound in a roll, as shown in FIG. 1. However, the recording device 1 is not limited to a configuration that can use such a recording medium, and may be configured to be able to use, for example, a recording medium in a shape in which long recording media are alternately folded.

[0032] 1, the recording apparatus 1 of this embodiment includes a delivery unit 101 that can set a roll-shaped recording medium M and rotate to deliver the recording medium M. The delivery unit 101 delivers the recording medium M to a first drive roller 106 via a driven roller 102 and a first tension roller 103. The recording medium M is then transported in a transport direction A by the first drive roller 106. Here, "driven" means that the delivery unit moves in accordance with the movement of the recording medium M that it comes into contact with.

[0033] A corona irradiation unit 201 that irradiates the transported recording medium M with a corona is provided near the driven roller 102. By irradiating the surface of the recording medium M with a corona, the surface of the recording medium M is modified, improving the recording quality.

[0034] The tension of the recording medium M being fed out from the feed-out unit 101 is detected by a first tension roller 103, and the torque of a feed-out motor 127 shown in FIG. 2 is controlled by a control unit 120. Between the first tension roller 103 and the first drive roller 106, there are provided an edge sensor 104 that detects the edge of the recording medium M, and a seam sensor 105 that detects the seam of the recording medium M. If the recording medium M is transported in a meandering manner, the control unit 120 controls based on the detection result of the edge sensor 104, and the feed-out unit 101 and the first tension roller 103 are linked to correct the meandering transport.

[0035] In addition, an ionizer 202 that irradiates ions is provided between the first tension roller 103 and the first drive roller 106. The surface of the recording medium M may become charged when the recording medium M is peeled off, but the surface of the recording medium M can be neutralized by irradiating it with ions from the ionizer 202 that have an opposite charge to the ions that have charged the surface of the recording medium M.

[0036] A driven roller 108 is provided downstream of the first drive roller 106 in the transport direction A, and a driven drum 109, which serves as a support unit for the recording medium M, is provided further downstream in the transport direction A. An eye mark sensor 107 is provided between the first drive roller 106 and the driven roller 108 to detect eye marks to be recorded on the recording medium M. Here, eye marks are marks used to control the timing of recording when recording is paused and then restarted, or when recording is to be performed after previous recording. The eye marks may be recorded on the recording medium M together with the image by a head 110 serving as a discharge unit, or may be recorded on the recording medium M in advance.

[0037] A plurality of heads 110 serving as ejection units for ejecting ink and a plurality of ultraviolet irradiation units 111 are provided at positions facing the driven drum 109. The recording apparatus 1 of this embodiment uses ultraviolet curable ink, which is cured by irradiation with ultraviolet light, for all of the inks, and therefore includes the ultraviolet irradiation unit 111 for curing the ink. However, the present invention can also use inks other than ultraviolet curable inks, in which case the ultraviolet irradiation unit 111 is not required. The recording apparatus 1 of this embodiment also includes seven heads 110: head 110a and head 110b that eject white ink for forming a background image; head 110c, head 110d, head 110e, and head 110f that eject colored inks for forming colored images; and head 110g that ejects post-treatment ink. The recording apparatus 1 also includes three ultraviolet irradiation units 111: ultraviolet irradiation unit 111a, ultraviolet irradiation unit 111b, and ultraviolet irradiation unit 111c. However, there is no particular limitation on the number and arrangement of the heads 110 and ultraviolet irradiation units 111.

[0038] At a position facing the head 110 and the ultraviolet irradiation unit 111, the recording medium M is transported while being wrapped around the driven drum 109. The driven drum 109 is provided with an encoder 130 as shown in Fig. 2, and the rotation speed of the driven drum 109, which corresponds to the transport speed of the recording medium M, is detected by the encoder 130, and the timing of ink ejection from the head 110 is controlled by the control unit 120 so that a desired image is formed at a desired position on the recording medium M. The transport distance of the recording medium M is also managed by the control unit 120 based on the detection result of the encoder 130.

[0039] A second drive roller 113 is provided downstream of the driven drum 109 in the transport direction A via a second tension roller 112. The tension in the transport direction A applied to the recording medium M wound around the driven drum 109 is detected by the second tension roller 112, and based on the detection result of the second tension roller 112, the control unit 120 controls the torque of the second transport motor 131 shown in FIG. 2, which is the drive motor for the second drive roller 113, to achieve a desired tension.

[0040] A third tension roller 114, a driven roller 115, and a driven roller 116 are arranged in this order downstream of the second drive roller 113 in the transport direction A. A winding unit 118 is provided downstream of the driven roller 116 in the transport direction A. The winding unit 118 can wind the recording medium M into a roll by rotating. The tension applied to the winding unit 118 can be detected by the third tension roller 114, and the desired tension is achieved by having the control unit 120 control the torque of the winding motor 133 (shown in FIG. 2), which is the drive motor for the winding unit 118, based on the detection result of the third tension roller 114. The tension can also be changed depending on the winding diameter of the recording medium M wound around the winding unit 118.

[0041] Next, the electrical configuration of the recording device 1 of this embodiment will be described using Figure 2. The recording device 1 of this embodiment is connected to a PC 2 and has a control unit 120 inside the recording device 1, but is not limited to this configuration. For example, the PC 2 connected to the recording device 1 may also be configured to perform at least part of the role of the control unit of the recording device 1.

[0042] The control unit 120 is provided with a CPU 121 that is responsible for overall control of the recording device 1. The CPU 121 is connected via a system bus 122 to a storage unit 123 that has a ROM that stores various control programs executed by the CPU 121, a RAM that can temporarily store data, an EEPROM, and the like.

[0043] The CPU 121 is also connected via a system bus 122 to a head driver 124 that drives each head 110 to eject ink. The CPU 121 is also connected via the system bus 122 to an ultraviolet irradiation unit driver 125 that drives each ultraviolet irradiation unit 111 to irradiate ultraviolet rays.

[0044] The CPU 121 is also connected via the system bus 122 to a corona irradiation unit drive unit 211 for driving the corona irradiation unit 201 to irradiate the corona. The CPU 121 is also connected via the system bus 122 to an ionizer drive unit 212 for driving the ionizer 202 to irradiate the ions.

[0045] The CPU 121 is also connected via the system bus 122 to a motor drive unit 126, which is connected to a feed motor 127, a first transport motor 129, a second transport motor 131, a discharge motor 132, a winding motor 133, a head movement motor 221, and a maintenance unit drive motor 222. Here, the feed motor 127 is a drive motor for the feed unit 101. The first transport motor 129 is a drive motor for the first drive roller 106. The second transport motor 131 is a drive motor for the second drive roller 113. The discharge motor 132 is a drive motor for the discharge roller 117. The winding motor 133 is a drive motor for the winding unit 118. The head movement motor 221 is a drive motor that constitutes a gap adjustment unit that moves the head 110 to change the gap between the head 110 and the driven drum 109, i.e., the gap PG (paper gap) between the head 110 and the recording medium M. The maintenance unit drive motor 222 is a drive motor for a wiper, suction cap, etc. (not shown) that can maintain the head 110, and constitutes a maintenance unit together with the wiper, suction cap, etc. By performing maintenance on the head 110, any solid matter adhering to the nozzles of the head 110 is removed, and the amount of radicals present in the head 110 is reduced.

[0046] The CPU 121 is also connected to the edge sensor 104, the seam sensor 105, and the eye mark sensor 107 via the system bus 122. The CPU 121 is also connected to the first tension roller 103, the second tension roller 112, and the third tension roller 114 via the system bus 122. The CPU 121 is also connected to the encoder 130 via the system bus 122. The CPU 121 is also connected to a PC 2, which transmits and receives data such as image data and signals, via the system bus 122, via an input / output unit 134.

[0047] Next, an embodiment of a recording method that can be executed by the recording apparatus 1 will be described with reference to FIG. 3. When recording data is input from, for example, the PC 2 and the recording method of this embodiment is started, as shown in FIG. 3, first, in step S110, the control unit 120 checks the recording conditions from the recording data. The recording conditions include, for example, the type of recording medium, whether or not a background image is to be recorded, and the ejection density of the background image. In this specification, "ejection density" refers to the number of effective pixels onto which ink is ejected. For example, when a configuration is configured to eject up to 100 dots per unit area, ejecting 50 dots of ink can be considered an ejection density of 50%.

[0048] After the recording conditions are confirmed in step S110, conveyance of the recording medium M is started in step S120. Then, in step S130, control unit 120 determines whether or not to irradiate the desired position on the recording medium M with a corona from corona irradiation unit 201. The determination of whether or not to irradiate with a corona is made based on the contents of the recording data confirmed in step S110. If it is determined in step S130 that a corona should be irradiated, the process proceeds to step S140, where the corona irradiation unit 201 irradiates the desired position on the recording medium M with a corona, and then the process proceeds to step S150. On the other hand, if it is determined in step S130 that a corona should not be irradiated, the process proceeds to step S150 without proceeding to step S140.

[0049] In step S150, the control unit 120 determines whether or not to irradiate a desired position on the recording medium M with ions from the ionizer 202. The determination of whether or not to irradiate with ions is made based on the contents of the recording data confirmed in step S110. If it is determined in step S150 that ions are to be irradiated, the process proceeds to step S160, where ions are irradiated from the ionizer 202 to a desired position on the recording medium M, and then the process proceeds to step S170. On the other hand, if it is determined in step S130 that ions are not to be irradiated, the process proceeds to step S170 without proceeding to step S160.

[0050] In step S170, the control unit 120 determines whether or not to record a background image at a desired position on the recording medium M. The determination of whether or not to record a background image is made based on the content of the recording data confirmed in step S110. If it is determined in step S170 that a background image will be recorded, the process proceeds to step S180, where white ink is ejected from heads 110a and 110b at a desired position on the recording medium M to form a background image, and then the process proceeds to step S190. On the other hand, if it is determined in step S170 that a background image will not be recorded, the process proceeds to step S190 without proceeding to step S180.

[0051] In step S190, a color image is recorded at a desired position on the recording medium M. Here, if a background image was recorded in step S180, a color image is recorded at the formation position of the background image. The color image is recorded by ejecting colored inks, namely black ink, cyan ink, magenta ink, and yellow ink, from head 110c, head 110d, head 110e, and head 110f, and, if necessary, ejecting post-treatment ink from head 110g. In addition, in steps S180 and S190, ultraviolet light is irradiated from each ultraviolet irradiation unit 111 in accordance with the ejection of each ink from each head.

[0052] After step S190 is completed, the process proceeds to step S200, where the control unit 120 determines whether all of the input recording data has been recorded. If it is determined that all of the input recording data has been recorded, the recording method of this embodiment ends. On the other hand, if it is determined that all of the input recording data has not been recorded, the process returns to step S130, and steps S130 to S190 are repeated until it is determined that all of the input recording data has been recorded.

[0053] To briefly summarize the recording apparatus 1 of this embodiment, the recording apparatus 1 of this embodiment includes a first drive roller 106 and a second drive roller 113 as a transport unit that transports the recording medium M, a corona irradiation unit 201 that is disposed on the transport path of the recording medium M and that modifies the surface of the recording medium M by irradiating the surface of the recording medium M with a corona, a head 110 that is disposed downstream of the corona irradiation unit 201 on the transport path and that serves as an ejection unit that ejects ink onto the recording medium M, and a control unit 120 that controls the driving of the first drive roller 106, the second drive roller 113, the corona irradiation unit 201, and the head 110. The head 110 includes head 110a and head 110b as first heads that eject white ink to form a background image, and heads 110c, 110d, 110e, and 110f as second heads that are disposed downstream of the first heads on the transport path and that eject colored inks to form colored images.

[0054] Here, when forming a background image on the recording medium M with white ink and then forming a colored image on the background image with colored inks, i.e., when executing step S190 via step S180, the control unit 120 can change the irradiation intensity of the corona irradiation unit 201 depending on the white ink ejection density. Specifically, when the white ink ejection density is high, the control unit 120 increases the irradiation intensity of the corona irradiation unit 201, and when the white ink ejection density is low, the control unit 120 decreases the irradiation intensity of the corona irradiation unit 201. FIG. 4 is a graph showing the relationship between the white ink ejection density and the irradiation intensity of the corona irradiation unit 201 that can be achieved by the control unit 120. For example, when the white ink ejection density is 100% as a first ejection density, the control unit 120 can set the irradiation intensity of the corona irradiation unit 201 to a first intensity of 2000 W. When the white ink ejection density is 50% as a second ejection density, which is lower than the first ejection density, the control unit 120 can set the irradiation intensity of the corona irradiation unit 201 to a second intensity of 1000 W, which is lower than the first intensity.

[0055] In other words, the recording apparatus 1 of this embodiment can be used to execute a recording method in which, when a background image is formed on the recording medium M with white ink and then a colored image is formed on the background image with colored inks, the irradiation intensity of the corona irradiation unit 201 is changed depending on the ejection density of the white ink. As a result of extensive research by the inventors, it was found that when a background image is formed on the recording medium M with white ink and then a colored image is formed on the background image with colored inks, the amount of radicals present on the surface of the recording medium M is reduced by corona irradiation, making ejection defects less likely to occur. Therefore, by executing the recording method using the recording apparatus 1 of this embodiment, when a background image is formed on the recording medium M with white ink and then a colored image is formed on the background image with colored inks, the occurrence of ink ejection defects can be effectively suppressed by changing the irradiation intensity of the corona irradiation unit 201 depending on the ejection density of the white ink.

[0056] Here, the control unit 120 can change the irradiation intensity of the corona irradiation unit 201 depending on the ejection density of the white ink when forming a background image on the recording medium M with white ink and then forming a colored image on the background image with colored inks, only if the recording medium M is a registered recording medium registered in advance in the storage unit 123. As a result of extensive research by the inventors, it has been found that the amount of radicals present on the surface of the recording medium M due to corona irradiation varies depending on the type of recording medium M. For this reason, by registering in advance in the storage unit 123 recording media M that are prone to have a large amount of radicals, and changing the irradiation intensity of the corona irradiation unit 201 depending on the ejection density of the white ink when forming a background image on the recording medium M with white ink and then forming a colored image on the background image with colored inks, only if the recording medium M is a registered recording medium, it is possible to prevent recording control from becoming complicated when using a recording medium M that is not a registered recording medium and is less likely to have a large amount of radicals and therefore less likely to cause ink ejection defects.

[0057] Here, in the recording device 1 of this embodiment, a recording medium M containing a resin as a material is registered in the storage unit 123 as a previously registered recording medium. Examples of recording media M containing a resin as a material include film-based media such as polyethylene terephthalate, polyethylene, and polypropylene. When a recording medium M containing a resin as a material is irradiated with a corona, the amount of radicals present on the surface increases, making it prone to ink ejection defects. However, in the recording device 1 of this embodiment, a recording medium M containing a resin as a material is registered in the storage unit 123 as a previously registered recording medium, so that ink ejection defects can be effectively suppressed even when a recording medium M containing a resin as a material is used.

[0058] Furthermore, when forming a colored image on the recording medium M with colored inks without forming a background image on the recording medium M with white ink, i.e., when executing step S190 without going through step S180, the control unit 120 can change the irradiation intensity of the corona irradiation unit 201 so that it is 20% or less of the maximum irradiation intensity of the corona irradiation unit 201 when forming a background image on the recording medium M with white ink and then forming a colored image on the background image with colored inks. For example, in this embodiment, the irradiation intensity can be set to 400 W, which is 20% of the maximum irradiation intensity of the corona irradiation unit 201, 2000 W. In this way, when forming a colored image on the recording medium M with colored inks without forming a background image on the recording medium M with white ink, which is prone to ink ejection defects, the occurrence of ink ejection defects can be effectively suppressed by reducing the irradiation intensity of the corona irradiation unit 201.

[0059] As described above, the recording apparatus 1 of this embodiment is also equipped with a head movement motor 221 as a gap adjustment unit that adjusts the gap PG between the head 110 and the recording medium M. The control unit 120 controls the head movement motor 221 to widen the gap PG when a colored image is formed on the recording medium M with colored inks without forming a background image on the recording medium M with white ink, compared to the gap PG when a background image is formed on the recording medium M with white ink and then a colored image is formed on the background image with colored inks. Widening the gap PG makes it less likely for radicals to adhere to the head 110. Therefore, by controlling in this manner, the control unit 120 can effectively suppress the occurrence of ink ejection defects even when a colored image is formed on the recording medium M with colored inks without forming a background image on the recording medium M with white ink, which is likely to generate a large number of radicals on the surface of the recording medium M.

[0060] As described above, the recording apparatus 1 of this embodiment also includes a maintenance unit including a wiper, suction cap, and maintenance unit drive motor 222 for maintaining the head 110. While maintenance by the maintenance unit is typically performed at predetermined intervals, the control unit 120 can control the maintenance unit to shorten the maintenance interval when forming a colored image on the recording medium M with colored inks without forming a background image on the recording medium M with white ink, compared to the maintenance interval when forming a background image on the recording medium M with white ink and then forming a colored image on the background image with colored inks. By shortening the maintenance interval, radicals are less likely to remain in the head 110. Therefore, by controlling in this manner, the control unit 120 can effectively suppress the occurrence of ink ejection defects, even when forming a colored image on the recording medium M with colored inks without forming a background image on the recording medium M with white ink, which is likely to generate a large number of radicals on the surface of the recording medium M.

[0061] Furthermore, in the recording device 1 of this embodiment, if the recording medium M to be used is a registered recording medium registered in advance in the storage unit 123 and the recording data does not include data for forming a background image with white ink, the control unit 120 can automatically add data for forming a background image with white ink to the recording data. Therefore, by registering a recording medium M that has a large amount of radicals present on its surface due to corona irradiation in the storage unit 123 as a registered recording medium, the recording device 1 of this embodiment can prevent a background image from being formed with white ink and an increase in radicals on the surface of the recording medium M, thereby effectively preventing ink ejection defects. In this case, the ejection density of the white ink when automatically adding data for forming a background image with white ink to the recording data may be changed depending on the irradiation intensity set for the corona irradiation unit 201.

[0062] The recording device 1 of this embodiment also has a first recording mode and a second recording mode. In the first recording mode, if the recording medium M is a registered recording medium that has been registered in advance and the recording data does not include data for forming a background image with white ink, the control unit 120 automatically adds data for forming a background image with white ink to the recording data. In the second recording mode, if the recording medium M is a registered recording medium that has been registered in advance and the recording data does not include data for forming a background image with white ink, the control unit 120 does not add data for forming a background image with white ink to the recording data. Therefore, if the user does not want to form a background image, they can select the second recording mode to form a colored image without forming a background image.

[0063] Furthermore, in the recording device 1 of this embodiment, when the recording medium M is a registered recording medium that has been registered in advance and the recording data includes data for forming a background image with white ink, the control unit 120 does not add data for forming a background image with white ink to the recording data. In other words, when the recording data includes data for forming a background image with white ink, the recording device 1 of this embodiment prevents the recording process from becoming more complicated by adding further data for forming a background image with white ink.

[0064] Furthermore, in the recording device 1 of this embodiment, when the recording medium M is a registered recording medium that has been registered in advance and the recording data does not include data for forming a background image with white ink, the control unit 120 can change the irradiation intensity of the corona irradiation unit 201 in accordance with the ejection density of the white ink when automatically adding data for forming a background image with white ink to the recording data. The higher the ejection density of the white ink, the less radicals there are on the recording medium M. By changing the irradiation intensity of the corona irradiation unit 201 in accordance with this tendency, it is possible to effectively suppress the occurrence of ink ejection defects.

[0065] The present invention is not limited to the above-described embodiments, and can be realized in various configurations without departing from the spirit of the present invention. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0066] 1...recording device, 2...PC, 101...feed-out section, 102...driven roller, 103...first tension roller, 104...end sensor, 105...seam sensor, 106...first drive roller (transport section), 107...eye mark sensor, 108...driven roller, 109...driven drum, 110...head (discharge section), 110a...head (first head), 110b...head (first head), 110c...head (second head), 110d...head (second head), 110e...head (second head), 110f...head (second head), 110g...head, 111...ultraviolet irradiation section, 111a...ultraviolet irradiation section, 111b...ultraviolet irradiation section, 111c...ultraviolet irradiation section, 112...second tension roller, 113...second drive roller (transport section) unit), 114...third tension roller, 115...driven roller, 116...driven roller, 117...discharge roller, 118...winding unit, 120...control unit, 121...CPU, 122...system bus, 123...storage unit, 124...head drive unit, 125...ultraviolet irradiation unit drive unit, 126...motor drive unit, 127...feed motor, 129...first transport motor, 130...encoder, 131...second transport motor, 132...discharge motor, 133...winding motor, 134...input / output unit, 201...corona irradiation unit, 202...ionizer, 211...corona irradiation unit drive unit, 212...ionizer drive unit, 221...head movement motor (gap adjustment unit), 222...maintenance unit drive motor (maintenance unit), M...recording medium

Claims

1. a conveying unit that conveys the recording medium; a corona irradiation unit disposed in a transport path of the recording medium and irradiating a surface of the recording medium with a corona to modify the surface; a discharge unit disposed downstream of the corona irradiation unit on the transport path and configured to discharge ink onto the recording medium; a control unit that controls driving of the transport unit, the corona irradiation unit, and the discharge unit; Equipped with the ejection unit includes a first head that ejects white ink as the ink to form a background image, and a second head that is disposed downstream of the first head on the transport path and ejects colored ink to form a colored image, a control unit that changes the ejection density of the white ink in accordance with the irradiation intensity of the corona irradiation unit when forming the background image on the recording medium with the white ink and then forming the colored image on the background image with the colored inks.

2. 2. The recording apparatus according to claim 1, The control unit changes the ejection density of the white ink in accordance with the irradiation intensity of the corona irradiation unit when forming the background image on the recording medium with the white ink and then forming the colored image on the background image with the colored inks, only if the recording medium is a previously registered recording medium.

3. 3. The recording apparatus according to claim 2, The recording device is characterized in that the registered recording medium contains resin as a material.

4. 4. The recording apparatus according to claim 1, a control unit that controls the irradiation intensity of the corona irradiation unit when forming the colored image on the recording medium with the colored inks without forming the background image on the recording medium with the white ink, to be 20% or less of the maximum irradiation intensity of the corona irradiation unit when forming the background image on the recording medium with the white ink and then forming the colored image on the background image with the colored inks.

5. 4. The recording apparatus according to claim 1, a gap adjusting unit that adjusts the gap between the ejection unit and the recording medium, The control unit controls the gap adjustment unit to widen the gap when forming the colored image on the recording medium with the colored inks without forming the background image on the recording medium with the white ink, compared to the gap when forming the background image on the recording medium with the white ink and then forming the colored image on the background image with the colored inks.

6. 4. The recording apparatus according to claim 1, a maintenance unit that performs maintenance on the discharge unit, The control unit controls the maintenance unit to make the maintenance interval by the maintenance unit shorter when forming the colored image on the recording medium with the colored inks without forming the background image on the recording medium with the white ink than the maintenance interval by the maintenance unit when forming the background image on the recording medium with the white ink and then forming the colored image on the background image with the colored inks.

7. a conveying unit that conveys the recording medium; a corona irradiation unit disposed in a transport path of the recording medium and irradiating a surface of the recording medium with a corona to modify the surface; a discharge unit disposed downstream of the corona irradiation unit on the transport path and configured to discharge ink onto the recording medium; a control unit that controls driving of the transport unit, the corona irradiation unit, and the discharge unit; Equipped with the ejection unit includes a first head that ejects white ink as the ink to form a background image, and a second head that is disposed downstream of the first head on the transport path and ejects colored ink to form a colored image, the control unit, when the recording medium is a registered recording medium that has been registered in advance and when data for forming the background image with the white ink is not included in the recording data, automatically adds data for forming the background image with the white ink to the recording data; a control unit that changes the ejection density of the white ink in accordance with the irradiation intensity of the corona irradiation unit when automatically adding data to form the background image with the white ink to the recording data if the recording medium is a previously registered recording medium and the recording data does not include data to form the background image with the white ink;

8. 8. The recording apparatus according to claim 7, The recording mode includes a first recording mode and a second recording mode, The control unit In the first recording mode, if the recording medium is a registered recording medium that has been registered in advance, and if the recording data does not include data for forming the background image with the white ink, data for forming the background image with the white ink is automatically added to the recording data, In the second recording mode, even if the recording medium is a registered recording medium that has been registered in advance and the recording data does not include data for forming the background image with the white ink, the recording device is characterized in that no data for forming the background image with the white ink is added to the recording data.

9. 9. The recording apparatus according to claim 7, The control unit is configured to not add data for forming the background image with white ink to the recording data when the recording medium is a previously registered recording medium and the recording data includes data for forming the background image with white ink.

10. a conveying unit that conveys the recording medium; a corona irradiation unit disposed in a transport path of the recording medium and irradiating a surface of the recording medium with a corona to modify the surface; a discharge unit disposed downstream of the corona irradiation unit on the transport path and configured to discharge ink onto the recording medium; Equipped with the ejection unit includes a first head that ejects white ink as the ink to form a background image, and a second head that is disposed downstream of the first head on the transport path and ejects colored ink to form a colored image, A recording method executable using a recording device, comprising: a recording method characterized in that, when forming a background image on the recording medium with the white ink and then forming a colored image on the background image with the colored inks, the ejection density of the white ink is changed depending on the irradiation intensity of the corona irradiation unit.

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