Method for determining the combination of inkjet printer, ink head, and ink tank.

Abstract

To effectively suppress the generation of ink mist in an inkjet printer equipped with multiple ink heads that eject multiple types of ink. [Solution] The inkjet printer 1 includes ink heads 61-64 that eject yellow (Y), magenta (M), black (K), and cyan (C) inks which are less likely to generate ink mist, and ink heads 65-68 that eject white (W), white (W), orange (O), and red (R) inks which are more likely to generate ink mist, and a heater 51 that heats the ink inside ink heads 61-64 and a heater 52 that heats the ink inside ink heads 65-68. The control device 100 sets the heating temperature of heater 52 higher than the heating temperature of heater 51.

Description

[Technical Field]

[0001] The present invention relates to an inkjet printer and a method for determining a combination of an ink head and an ink tank. [Background Art]

[0002] Conventionally, inkjet printers including a plurality of ink heads that eject a plurality of types of ink, such as inkjet printers that form color images, have been known. For a plurality of types of ink, the characteristics of the ink differ for each ink. For example, even when the temperature of the ink is the same, the viscosity varies from one type of ink to another. Patent Document 1 describes an inkjet printer that controls the temperature of ink in each ink head such that the viscosity of each ink in the plurality of ink heads becomes uniform.

[0003] The inkjet printer described in Patent Document 1 aims to equalize the ejection speed of each ink by equalizing the viscosity of ink in the plurality of ink heads. If the ink ejection speed is uniform, displacement of the landing positions of ink on a medium can be prevented. Patent Document 1 describes that equalizing the viscosity of ink in the plurality of ink heads results in a good-quality image formed on the medium. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 2004-338176 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] Incidentally, numerous fine ink droplets are continuously ejected from the ink head. Ink mist may form in the space between the ink head and the media. If this mist adheres to the media, it will lead to a decrease in image quality. Therefore, it is preferable to suppress the generation of ink mist as much as possible. Here, the composition of ink differs for each ink, and the ease with which mist is generated varies depending on the type of ink. Simply making the viscosity of the inks the same, as in the inkjet printer described in Patent Document 1, makes it difficult to effectively suppress the generation of mist.

[0006] The object of the present invention is to provide a technology that can effectively suppress the generation of ink mist in an inkjet printer equipped with multiple ink heads that eject multiple types of ink. [Means for solving the problem]

[0007] The inkjet printer disclosed herein includes a first ink head for ejecting a first ink, a second ink head for ejecting a second ink of a different type from the first ink, a first heater for heating the first ink inside the first ink head, a second heater for heating the second ink inside the second ink head, and a control device. The control device includes a storage unit for storing a first mist index representing the ease with which ink mist is generated when the first ink at a predetermined temperature is ejected from the first ink head, and a second mist index representing the ease with which ink mist is generated when the second ink at the predetermined temperature is ejected from the second ink head, and a heater control unit for controlling the first heater and the second heater such that the heating temperature of the first heater is higher than the heating temperature of the second heater when the first mist index is greater than the second mist index, and the heating temperature of the first heater is lower than the heating temperature of the second heater when the first mist index is smaller than the second mist index.

[0008] According to the above inkjet printer, if the first ink is more prone to generating ink mist than the second ink, the first mist index will be higher than the second mist index, so the heating temperature of the first heater will be controlled to be higher than the heating temperature of the second heater. As a result, the temperature of the first ink inside the first ink head will be higher than the temperature of the second ink inside the second ink head. On the other hand, if the first ink is less prone to generating ink mist than the second ink, the first mist index will be lower than the second mist index, so the heating temperature of the first heater will be controlled to be lower than the heating temperature of the second heater. As a result, the temperature of the first ink inside the first ink head will be lower than the temperature of the second ink inside the second ink head. Therefore, the temperature of the ink that is more prone to generating mist can be made higher than the temperature of the ink that is less prone to generating mist, and the viscosity of the ink that is more prone to generating mist can be reduced. Thus, the generation of mist is effectively suppressed for the ink that is more prone to generating mist. According to the above inkjet printer, the generation of ink mist can be effectively suppressed.

[0009] The method for determining the combination of an ink head and an ink tank disclosed herein is a method for determining the combination of an ink head and an ink tank in an inkjet printer comprising: first and second ink heads, each consisting of a predetermined ink head that ejects ink; a first heater for heating the ink inside the first ink head; a second heater for heating the ink inside the second ink head; a first ink tank for containing the first ink; and a second ink tank for containing the second ink. Here, the heating temperature of the first heater is higher than the heating temperature of the second heater. The combination determination method includes a measurement step of measuring a first mist index representing the ease with which ink mist is generated when the first ink at a predetermined temperature is discharged from the predetermined ink head, and a second mist index representing the ease with which ink mist is generated when the second ink at a predetermined temperature is discharged from the predetermined ink head; and a connection step of connecting the first ink tank to the first ink head and the second ink tank to the second ink head if the first mist index is greater than the second mist index, and connecting the second ink tank to the first ink head and the first ink tank to the second ink head if the second mist index is greater than the first mist index.

[0010] According to the above combination determination method, the heating temperature of the first heater is higher than that of the second heater, so the ink in the first ink head is at a higher temperature than the ink in the second ink head. If the first ink is more prone to misting than the second ink, the first ink tank is connected to the first ink head. Therefore, the generation of mist is effectively suppressed for the first ink, which is more prone to misting than the second ink. On the other hand, if the second ink is more prone to misting than the first ink, the second ink tank is connected to the first ink head. Therefore, the generation of mist is effectively suppressed for the second ink, which is more prone to misting than the first ink. Thus, according to the above combination determination method, the generation of ink mist in an inkjet printer can be effectively suppressed. [Effects of the Invention]

[0011] According to the present invention, in an inkjet printer equipped with multiple ink heads that eject multiple types of ink, the generation of ink mist can be effectively suppressed. [Brief explanation of the drawing]

[0012] [Figure 1] This is a front view of the inkjet printer according to the embodiment. [Figure 2] This is a schematic diagram of the ink tank, ink head, and ink supply path. [Figure 3] This is a cross-sectional view showing the internal structure of the ink head. [Figure 4] This is a block diagram of the control system for an inkjet printer. [Figure 5] This is a diagram showing an example of a printed pattern image. [Figure 6] This is a diagram illustrating another example of a printed pattern image. [Figure 7] This table shows the relationship between the number of mist particles and the heater temperature. [Figure 8]This is a flowchart showing how to determine the combination of the ink head and ink tank. [Modes for carrying out the invention]

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Naturally, the embodiments described herein are not intended to limit the present invention. Furthermore, the same reference numerals are used for members and parts that perform the same function, and redundant explanations are omitted or simplified as appropriate.

[0014] (First Embodiment) Figure 1 is a front view of an inkjet printer 1 according to one embodiment. The inkjet printer 1 includes a platen 11 that supports media 5, ink head units U1 and U2, an ink supply unit 70 that supplies ink to the ink head units U1 and U2, a carriage 50 that supports the ink head units U1 and U2, a carriage moving device 40 that moves the carriage 50 in the main scanning direction Y, a media transport device 30 that transports the media 5 in a sub-scanning direction perpendicular to the main scanning direction Y, and a control device 100.

[0015] The carriage movement device 40 comprises a guide rail 41 extending in the main scanning direction Y, a left pulley 42, a right pulley 43, a belt 44, and a scan motor 45. The guide rail 41 is located above the platen 11. The carriage 50 is slidably engaged with the guide rail 41. The carriage 50 is fixed to the belt 44. The belt 44 is wrapped around the pulleys 42 and 43. The scan motor 45 is connected to the right pulley 43. When the scan motor 45 is driven, the pulley 43 rotates, causing the belt 44 to travel between the pulleys 42 and 43. As the belt 44 travels, the carriage 50 moves in the main scanning direction Y. The scan motor 45 is electrically connected to and controlled by the control device 100.

[0016] The medium conveying device 30 comprises a grit roller 31, a pinch roller 32, and a feed motor 33. The grit roller 31 is provided on the platen 11. The grit roller 31 rotates when driven by the feed motor 33. The pinch roller 32 is disposed above the grit roller 31. The pinch roller 32 is provided so as to face the grit roller 31. The pinch roller 32 is configured to be swingable up and down so as to be capable of moving toward and away from the grit roller 31. When the grit roller 31 rotates in a state where the medium 5 is nipped between the pinch roller 32 and the grit roller 31, the medium 5 is conveyed in the sub-scanning direction. The feed motor 33 is electrically connected to the control device 100 and is controlled by the control device 100.

[0017] As shown in Figure 2, the ink head unit U1 has four ink heads 61 to 64. The ink heads 61 to 64 are integrally formed and constitute the ink head unit U1. The ink head unit U2 has four ink heads 65 to 68. The ink heads 65 to 68 are integrally formed and constitute the ink head unit U2. The ink head unit U1 and the ink head unit U2 are separate bodies from each other.

[0018] The ink heads 61 to 68 are arranged in the main scanning direction Y. The ink heads 61 to 68 have the same configuration, and each is configured by an ink head 90 described below. The ink head 90 is an example of "a predetermined ink head". As shown in FIG. 3, the ink head 90 includes an ink chamber 91, a plurality of pressure chambers 92 communicating with the ink chamber 91, a nozzle plate 93 partitioning a part of the pressure chambers 92, a plurality of nozzles 94 formed in the nozzle plate 93, a vibration plate 95 partitioning another part of the pressure chambers 92, and an actuator 96 formed of a piezoelectric element attached to the vibration plate 95. The pressure chamber 92, the vibration plate 95, and the actuator 96 are provided for each nozzle 94, and the number thereof (for example, 300) is the same. The actuator 96 is electrically connected to a control device 100. The control device 100 transmits drive signals to the actuator 96. When the control device 100 drives the actuator 96, the vibration plate 95 bends, the ink in the pressure chamber 92 is pressurized or depressurized, and ink is ejected from the nozzle 94.

[0019] The ink supply unit 70 (see FIG. 1) includes ink tanks 71 to 78 for storing ink, and ink supply paths 81 to 88. As shown in FIG. 2, the ink supply paths 81 to 88 are flow paths connecting the ink tanks 71 to 78 and the ink heads 61 to 68 respectively. The configuration of the ink supply paths 81 to 88 is not particularly limited, and for example, they are formed of flexible tubes. The ink in the ink tanks 71 to 78 flows through the ink supply paths 81 to 88 respectively and is supplied to the ink heads 61 to 68.

[0020] Ink tanks 71-78 each contain yellow (Y), magenta (M), black (K), cyan (C), white (W), white (W), orange (O), and red (R) inks, respectively. Therefore, ink heads 61-68 eject yellow (Y), magenta (M), black (K), cyan (C), white (W), white (W), orange (O), and red (R) inks, respectively. The above inks may be, for example, solvent-based pigment inks or water-based pigment inks. Alternatively, the above inks may be water-based dye inks or UV-curable pigment inks that harden when exposed to ultraviolet light. If the above inks are UV-curable inks, the carriage 50 is provided with a UV irradiation device (not shown) that irradiates them with ultraviolet light. The ink tanks 71-78 may be, for example, box-shaped ink cartridges or pouch-shaped inks.

[0021] The inkjet printer 1 includes a heater 51 for heating the ink head unit U1 and a heater 52 for heating the ink head unit U2. Heater 51 is configured to heat the ink inside the ink heads 61-64. Heater 52 is configured to heat the ink inside the ink heads 65-68. Heaters 51 and 52 only need to be able to heat the ink inside the ink heads 61-68, and their configuration is not particularly limited. Heater 51 may, for example, be attached to the outer surface of the ink heads 61-64, or it may consist of a heater 55 (see Figure 3) embedded inside the ink heads 61-64. Similarly, heater 52 may, for example, be attached to the outer surface of the ink heads 65-68, or it may consist of a heater 55 (see Figure 3) embedded inside the ink heads 65-68.

[0022] The inkjet printer 1 includes a temperature sensor 53 for measuring the ink temperature of the ink head unit U1 and a temperature sensor 54 for measuring the ink temperature of the ink head unit U2. The temperature sensor 53 is configured to measure the ink temperature inside the ink heads 61-64, and the heater 51 is controlled based on the detection result of the temperature sensor 53. The temperature sensor 54 is configured to measure the ink temperature inside the ink heads 65-68, and the heater 52 is controlled based on the detection result of the temperature sensor 54. The temperature sensors 53 and 54 only need to be able to measure the ink temperature inside the ink heads 61-68, and their configuration is not particularly limited. The temperature sensor 53 may, for example, be attached to the outer surface of the ink heads 61-64, or it may be composed of a temperature sensor 56 (see Figure 3) embedded inside the ink heads 61-64. Similarly, the temperature sensor 54 may, for example, be attached to the outer surface of the ink heads 65-68, or it may be composed of a temperature sensor 56 (see Figure 3) embedded inside the ink heads 65-68.

[0023] As shown in Figure 4, the control device 100 is electrically connected to the feed motor 33, the scan motor 45, and each actuator 96. The control device 100 performs printing by controlling the feed motor 33, the scan motor 45, and each actuator 96. The control device 100 is also electrically connected to the temperature sensor 53, the temperature sensor 54, the heater 51, and the heater 52. The control device 100 receives the detection signal from the temperature sensor 53 and controls the heating temperature of the heater 51 by adjusting the output of the heater 51. The control device 100 also receives the detection signal from the temperature sensor 54 and controls the heating temperature of the heater 52 by adjusting the output of the heater 52. The control device 100 is composed of a microcomputer having a CPU, RAM, and ROM. The control device 100 constitutes the pattern printing unit 101, the storage unit 102, and the heater control unit 103, which will be described later.

[0024] Since the ink heads 61-68 continuously eject numerous fine ink droplets, ink mist may be generated in the space between the ink heads 61-68 and the media 5 when the ink is ejected. Here, the likelihood of mist generation varies depending on the ink, for example, due to differences in the size of the pigments contained in the ink. Even if the ink temperature and ejection speed are the same, the likelihood of mist generation varies depending on the ink. The inks used in the inkjet printer 1 include a mixture of inks that are prone to generating mist and inks that are not prone to generating mist.

[0025] In inkjet printer 1, ink mist tends to be less likely to occur as the temperature of the ejected ink (hereinafter also referred to as the ejection temperature) increases. In the ink used in inkjet printer 1, the viscosity of the ink decreases as the ink temperature increases, and this decrease in viscosity suppresses the generation of mist. Therefore, by lowering the viscosity of the ink that is prone to generating mist compared to the ink that is less prone to generating mist, the generation of mist can be effectively suppressed. In this embodiment, the generation of mist is suppressed by raising the ejection temperature of the ink that is prone to generating mist compared to the ejection temperature of the ink that is less prone to generating mist. As will be described later, the ink ejection temperature (in other words, the ink temperature inside the ink head) is set based on a mist index that represents the ease with which mist is generated.

[0026] In this embodiment, the pattern printing unit 101 (see Figure 4) of the control device 100 prints a predetermined pattern image using each ink. For example, as shown in Figure 5, the pattern printing unit 101 prints a rectangle P1 on the media by ejecting ink from the ink head while moving the ink head in the main scanning direction Y1. When mist is generated during this printing, the mist floats in the main scanning direction Y1 and adheres to the media 5. As a result, a region P2 where mist adheres is formed on the main scanning direction Y1 side of the rectangle P1. Since the mist consists of multiple minute droplets, when the mist adheres to the media 5, it appears as multiple dots on the media 5. If the amount of mist generated is small, the number of dots on the media 5 (hereinafter referred to as the number of mist particles) is small, but as shown in Figure 6, the more mist generated, the more mist particles there are. In this embodiment, the number of mist particles when ink is ejected while the ink temperature is maintained at a predetermined temperature (here, 45°C) is used as the mist index.

[0027] In this embodiment, the pattern printing unit 101 prints pattern images for each of the ink heads 61 to 68. Specifically, it prints a pattern image using yellow (Y) ink with only ink head 61, a pattern image using magenta (M) ink with only ink head 62, a pattern image using black (K) ink with only ink head 63, a pattern image using cyan (C) ink with only ink head 64, a pattern image using white (W) ink with only ink head 65, a pattern image using white (W) ink with only ink head 66, a pattern image using orange (O) ink with only ink head 67, and a pattern image using red (R) ink with only ink head 68. Since the ink ejected from both ink head 65 and ink head 66 is white (W) ink, either printing a pattern image using white ink with only ink head 65 or printing a pattern image using white ink with only ink head 66 may be omitted. After printing as described above, the number of mist particles for yellow (Y), magenta (M), black (K), cyan (C), white (W), orange (O), and red (R) inks is measured based on the print results of each pattern image. Based on these measurement results, the number of mist particles for each ink can be set, and the likelihood of mist generation can be evaluated.

[0028] Information on the number of mist particles for each ink is input to the control device 100. The storage unit 102 of the control device 100 (see Figure 4) stores the number of mist particles for each ink. Specifically, the storage unit 102 stores the number of mist particles when yellow (Y), magenta (M), black (K), cyan (C), white (W), white (W), orange (O), and red (R) inks are ejected from the ink heads 61 to 68 at predetermined temperatures. The storage unit 102 also stores the relationship between a predetermined number of mist particles and the heater temperature (heating temperature of the heater). In this embodiment, as shown in Figure 7, if the number of mist particles is less than 10,000, the heater temperature is set to 45°C; if the number of mist particles is 10,000 or more but less than 30,000, the heater temperature is set to 47°C; and if the number of mist particles is 30,000 or more, the heater temperature is set to 50°C.

[0029] Among the inks used in the inkjet printer 1, the yellow (Y), magenta (M), black (K), and cyan (C) inks are inks that are relatively less prone to misting. The number of mist particles for the yellow (Y), magenta (M), black (K), and cyan (C) inks is less than 10,000, and this is stored in the memory unit 102 of the control device 100. The yellow (Y), magenta (M), black (K), and cyan (C) inks are ejected from the ink head unit U1. Therefore, the heater control unit 103 of the control device 100 (see Figure 4) controls the heating temperature of the heater 51 that heats the ink head unit U1 to 45°C. As a result, the ejection temperature of the yellow (Y), magenta (M), black (K), and cyan (C) inks becomes 45°C.

[0030] White (W), orange (O), and red (R) inks are more prone to misting than yellow (Y), magenta (M), black (K), and cyan (C) inks. Furthermore, white (W) ink is more prone to misting than orange (O) and red (R) inks. The number of mist particles for white (W) ink is 30,000 or more, while the number of mist particles for orange (O) and red (R) inks is between 10,000 and 30,000. This information is stored in the memory unit 102 of the control device 100. For orange (O) and red (R) inks, the appropriate heater temperature is 47°C, while for white (W) ink, the appropriate heater temperature is 50°C. In this embodiment, the heater 52 heats not only the ink heads 65 and 66 that eject white (W) ink, but also the ink head 67 that ejects orange (O) ink and the ink head 68 that ejects red (R) ink. Therefore, the heating temperature of the heater 52 is set to 50°C, which is the higher of 47°C and 50°C. The heater control unit 103 of the control device 100 controls the heating temperature of the heater 52 that heats the ink head unit U2 to 50°C. As a result, the ejection temperature of the white (W), orange (O), and red (R) inks becomes 50°C.

[0031] As described above, the inkjet printer 1 according to this embodiment includes ink heads 61-64 that eject yellow (Y), magenta (M), black (K), and cyan (C) inks, ink heads 65-68 that eject white (W), orange (O), and red (R) inks, a heater 51 that heats the ink inside ink heads 61-64, a heater 52 that heats the ink inside ink heads 65-68, and a control device 100. The storage unit 102 of the control device 100 stores the number of mist particles for yellow (Y), magenta (M), black (K), and cyan (C) inks (an example of a "first mist index") and the number of mist particles for white (W), orange (O), and red (R) inks (an example of a "second mist index"). Here, the number of mist particles for yellow (Y), magenta (M), black (K), and cyan (C) inks is smaller than the number of mist particles for white (W), orange (O), and red (R) inks. Therefore, the heater control unit 103 of the control device 100 lowers the heating temperature of heater 51 to a lower temperature than that of heater 52. In this embodiment, the heating temperature of heater 51 is controlled to 45°C, and the heating temperature of heater 52 is controlled to 50°C. As a result, the temperature of the white (W), orange (O), and red (R) inks inside ink heads 65-68 is higher than the temperature of the yellow (Y), magenta (M), black (K), and cyan (C) inks inside ink heads 61-64. The viscosity of the white (W), orange (O), and red (R) inks decreases compared to when the temperature is 45°C. Therefore, the generation of mist is suppressed for white (W), orange (O), and red (R) inks, which are more prone to mist generation. According to the inkjet printer 1 of this embodiment, the generation of ink mist can be effectively suppressed.

[0032] Furthermore, according to this embodiment, the number of mist particles is used as the mist index. In determining the number of mist particles, yellow (Y), magenta (M), black (K), cyan (C), white (W), white (W), orange (O), and red (R) inks at predetermined temperatures are ejected from ink heads 61 to 68, respectively, to form a pattern image on the media 5 (see Figures 5 and 6). Then, the number of mist particles is measured for each ink. The measured number of mist particles is input to the control device 100 automatically or manually and stored in the storage unit 102. According to this embodiment, since the mist index is determined based on the actually printed pattern image, the likelihood of mist generation can be identified more accurately.

[0033] In this embodiment, the heater that heats the ink in the ink heads 65-68 is a single heater 52 (see Figure 2). Therefore, it is not possible to control the heating temperature for each ink head 65-68. However, for example, the heater that heats the white (W) ink inside ink heads 65 and 66 and the heater that heats the orange (O) and red (R) inks inside ink heads 67 and 68 may be separate, and the heating temperature of each heater may be controlled separately. In this case, by setting the heating temperature of the heater that heats the white (W) ink inside ink heads 65 and 66 to 50°C and the heating temperature of the heater that heats the orange (O) and red (R) inks inside ink heads 67 and 68 to 47°C, it is possible to reduce the heating temperature of the heaters for ink heads 67 and 68 compared to the above embodiment while suppressing the generation of mist from the white (W), orange (O), and red (R) inks.

[0034] Furthermore, the heater does not have to be provided in common to multiple ink heads among the ink heads 61 to 68; it may be provided in each of the ink heads 61 to 68.

[0035] (Second Embodiment) In the first embodiment, the heating temperatures of heaters 51 and 52 are controlled based on the ink mist index in the ink heads 61 to 68. On the other hand, in the second embodiment, the combination of ink heads 61 to 68 and ink tanks 71 to 78 is determined according to predetermined heating temperatures of heaters 51 and 52. The configuration of the inkjet printer is the same as in the first embodiment, so the description of the inkjet printer configuration will be omitted in the following description.

[0036] In this embodiment, the heating temperatures of heater 51 and heater 52 are predetermined constant temperatures, set to 45°C and 50°C, respectively. The heating temperature of heater 52 is higher than that of heater 51.

[0037] Figure 8 is a flowchart illustrating the method for determining the combination of an ink head and an ink tank according to this embodiment. In this embodiment as well, a measurement step is performed in advance to measure the mist index of each ink (step S1 in Figure 8). In this embodiment, as in the first embodiment, the number of mist particles is used as the mist index. Before determining the combination of an ink head and an ink tank, the number of mist particles of each ink is measured in advance. The method for measuring the number of mist particles is as described above.

[0038] Since the heating temperature of heater 52 is higher than that of heater 51, the ink temperature inside ink heads 65-68 is higher than the ink temperature inside ink heads 61-64. Therefore, in the connection process (see step S2 in Figure 8) where ink tanks 71-78 are connected to ink heads 61-68, the ink tanks containing inks that are prone to misting are connected to ink heads 65-68, and the ink tanks containing inks that are less prone to misting are connected to ink heads 61-64. In this case, the number of mist particles for white (W) ink is 30,000 or more, the number of mist particles for orange (O) and red (R) inks is 10,000 or more but less than 30,000, and the number of mist particles for yellow (Y), magenta (M), black (K), and cyan (C) inks is less than 10,000. White (W), orange (O), and red (R) inks are more prone to misting than yellow (Y), magenta (M), black (K), and cyan (C) inks. Therefore, ink tanks 71-74 containing yellow (Y), magenta (M), black (K), and cyan (C) inks are connected to ink heads 61-64, and ink tanks 75-78 containing white (W), white (W), orange (O), and red (R) inks are connected to ink heads 65-68.

[0039] According to this embodiment, similar to the first embodiment, the ejection temperatures of white (W), orange (O), and red (R) inks are higher than those of yellow (Y), magenta (M), black (K), and cyan (C) inks. Therefore, the generation of mist is suppressed for white (W), orange (O), and red (R) inks, which are more prone to mist generation. In this embodiment as well, the generation of ink mist can be effectively suppressed.

[0040] In the embodiments described above, the number of mist particles was used as the mist index, but the mist index can be any index that represents the ease of mist generation, and is not limited to the number of mist particles. [Explanation of symbols]

[0041] 1. Inkjet printer 5 Media 51, 52 Heater 53, 54 Temperature sensors 61-68 Inkhead 71-78 Ink Tanks 81-88 Ink supply path 100 Control device 101 Pattern Printing Section 102 Storage section 103 Heater control unit

Claims

1. A first ink head that ejects the first ink, A second ink head that ejects a second ink of a different type from the first ink, A first heater for heating the first ink inside the first ink head, A second heater for heating the second ink inside the second ink head, A control device is provided, The control device is A storage unit that stores a first mist index representing the ease with which ink mist is generated when the first ink at a predetermined temperature is ejected from the first ink head, and a second mist index representing the ease with which ink mist is generated when the second ink at a predetermined temperature is ejected from the second ink head. A heater control unit controls the first heater and the second heater such that when the first mist index is greater than the second mist index, the heating temperature of the first heater is set higher than the heating temperature of the second heater, and when the first mist index is smaller than the second mist index, the heating temperature of the first heater is set lower than the heating temperature of the second heater. An inkjet printer that has this feature.

2. The control device is A first pattern printing unit prints a first pattern image onto a medium by ejecting the first ink at a predetermined temperature from the first ink head, The system includes a second pattern printing unit that prints a second pattern image onto a medium by ejecting the second ink at a predetermined temperature from the second ink head, The inkjet printer according to claim 1, wherein the storage unit stores a first mist index input based on a printed first pattern image and a second mist index input based on a printed second pattern image.

3. An inkjet printer comprising first and second ink heads, each consisting of a predetermined ink head that ejects ink; a first heater for heating the ink inside the first ink head; a second heater for heating the ink inside the second ink head; a first ink tank for containing the first ink; and a second ink tank for containing the second ink, wherein a method for determining the combination of ink heads and ink tanks is provided. The heating temperature of the first heater is higher than the heating temperature of the second heater. A measurement step for measuring a first mist index representing the ease with which ink mist is generated when the first ink at a predetermined temperature is ejected from the predetermined ink head, and a second mist index representing the ease with which ink mist is generated when the second ink at a predetermined temperature is ejected from the predetermined ink head. A connection step is to connect the first ink tank to the first ink head and the second ink tank to the second ink head if the first mist indicator is greater than the second mist indicator, and to connect the second ink tank to the first ink head and the first ink tank to the second ink head if the second mist indicator is greater than the first mist indicator. A method for determining the combination of an ink head and an ink tank, including the following.

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