JP7629723B2 - Printer - Google Patents

Description

The present invention relates to a printer.

For example, Patent Document 1 discloses a printer that prints on a medium. This type of printer has a platen that supports the medium and an ink head that ejects ink. Printing is performed on the medium by ejecting ink from the ink head toward the medium supported by the platen.

This type of printer is capable of printing on various types of media. For example, Patent Document 2 discloses heat shrink film as a type of media that the printer can print on. This heat shrink film is used as a label that is attached to the surface of a container such as a plastic bottle. The heat shrink film shrinks when heat of a predetermined temperature or higher is applied. For example, after printing, the heat shrink film is partially shrunk by heat so that it conforms to the shape of the container's surface. This allows the heat shrink film to be attached along the surface of the container.

JP 2004-196537 A JP 2013-111766 A

When the above-mentioned heat shrink film is applied to the surface of a container, printing is performed on the heat shrink film using a printer, and then heat is applied to the printed heat shrink film to cause it to partially shrink. At this time, since the heat shrink film is partially shrunk, color unevenness can occur between the shrunk and unshrunk parts. Even in the shrunk parts of the heat shrink film, color unevenness can occur in parts with different shrinkage rates.

The present invention was made in consideration of these points, and its purpose is to provide a printer that is less likely to cause color unevenness even when a shrinkable or expandable medium is printed on and then the medium is then shrunk or expanded.

The printer according to the present invention includes a support base, an ink head, and a control device. The support base supports a medium. The ink head ejects ink onto the medium supported by the support base. The medium is a medium that is provided along the surface of a three-dimensional object and is capable of shrinking or expanding. The medium has a printing area into which ink is ejected, and is configured to shrink or expand to correspond to the surface shape of the three-dimensional object. The control device includes a storage unit, a division unit, a determination unit, and a printing unit. The storage unit stores a shrinkage/expansion rate for each portion of the medium that is preset to correspond to the surface shape of the three-dimensional object. The division unit divides the printing area into a plurality of divided areas based on the shrinkage/expansion rate for each portion of the medium stored in the storage unit. The determination unit determines a divided ink ejection amount, which is an ink ejection amount per unit area, for each divided area based on the shrinkage/expansion rate, so that the larger the rate of shrinkage, the smaller the ink ejection amount per unit area, and the larger the rate of expansion, the larger the ink ejection amount per unit area. The printing unit ejects ink from the ink head onto the printing area of the medium so that the ink ejection amount per unit area for each divided area is the divided ink ejection amount.

According to the above printer, the greater the contraction rate of the medium in the portion, the greater the contraction rate of the medium, and the greater the contraction rate of the printed portion, the darker the ink color in the printed portion than the shade desired by the user. Therefore, by reducing the amount of ink ejected per unit area during printing in the portion of the medium with a greater contraction rate, the ink color shade in the printed portion can be made closer to the shade desired by the user after the medium and printed portion have been contracted. The greater the expansion rate of the medium in the portion, the greater the expansion rate of the medium, and the greater the expansion rate of the printed portion, the greater the contraction rate of the medium, and the greater the expansion rate of the medium, the greater the ink color shade in the printed portion can be made lighter than the shade desired by the user. Therefore, by increasing the amount of ink ejected per unit area during printing in the portion of the medium with a greater expansion rate, the ink color shade in the printed portion can be made closer to the shade desired by the user after the medium and printed portion have been expanded. Therefore, even if the medium is contracted or expanded after printing on a medium that can be contracted or expanded, the shade of the printed portion can be made closer to the shade desired by the user, and color unevenness is less likely to occur.

1 is a perspective view of a printer according to an embodiment. FIG. 2 is a front view of the printer with the cover open. FIG. 1 is a block diagram of a printer according to an embodiment. FIG. 11 is a front view showing an example of a three-dimensional object to which a medium is attached. FIG. 2 illustrates the medium before it is thermally shrunk. 10 is a flowchart showing a procedure for printing on a medium that is partially shrunk by heat. FIG. 13 is a diagram showing a correction value table. FIG. 13 illustrates another embodiment of the media before it is heat shrunk. 13 is a front view showing an example of a three-dimensional object to which a medium is attached in another embodiment. FIG. FIG. 13 is a diagram showing a correction value table in another embodiment.

Below, an embodiment of a printer according to the present invention will be described with reference to the drawings. Note that the embodiment described here is, of course, not intended to limit the present invention in any particular way.

Figures 1 and 2 are respectively a perspective view and a front view of a printer 10 according to this embodiment. The symbols F, Rr, L, R, U, and D in the drawings indicate the front, rear, left, right, top, and bottom of the printer 10, respectively. The symbols X and Y indicate the sub-scanning direction and main scanning direction, respectively. For example, the main scanning direction Y is the left-right direction, and the sub-scanning direction X is the front-back direction. However, these directions are merely defined for the convenience of explanation, and do not limit the installation mode of the printer 10 in any way.

As shown in FIG. 2, the printer 10 is a device that ejects ink onto the medium 5 to print on the medium 5. In this embodiment, the printer 10 is an inkjet printer, but the printing method is not particularly limited. The printer 10 is a so-called flatbed type printer. However, the printer 10 may also be a so-called roll-to-roll type printer.

As shown in FIG. 1, the printer 10 comprises a case 11, a cover 12, and an operation panel 13. The case 11 is, for example, rectangular and has an internal space. Printing takes place in this internal space. As shown in FIG. 2, an opening 15 is formed in the front of the case 11. The cover 12 is supported by the case 11 so that the opening 15 can be opened and closed freely. The cover 12 is configured to be rotatable around its rear end. As shown in FIG. 1, a window 16 formed, for example, of a transparent acrylic plate is provided in the front and top of the cover 12.

The operation panel 13 is provided on the case 11. The operation panel 13 is a panel on which the user performs operations related to printing. The operation panel 13 includes, for example, a display screen 13a on which information related to printing is displayed, and input buttons 13b that allow the user to set information related to printing.

Next, the internal configuration of the printer 10 will be described. As shown in FIG. 2, the printer 10 includes a guide rail 18, a carriage 20, an ink head 22, a light irradiation device 26, and a carriage movement mechanism 28 (see FIG. 3).

The guide rail 18 is fixed to the case 11 in the internal space of the case 11. The guide rail 18 extends in the primary scanning direction Y. The carriage 20 is slidably engaged with the guide rail 18. The carriage 20 is movable in the primary scanning direction Y along the guide rail 18.

The ink heads 22 are provided on the carriage 20. There is no particular limit to the number of ink heads 22, but here there are four. The ink heads 22 eject ink toward a medium 5 supported by a support base 40, which will be described later. The ink heads 22 are disposed above the support base 40. The four ink heads 22 are disposed side by side in the main scanning direction Y. Although not shown in the figure, a plurality of nozzles that eject ink are formed on the bottom surface of each ink head 22.

In this embodiment, the ink ejected from the ink head 22 is a photocurable ink, the hardening of which is accelerated when light (e.g., ultraviolet light or infrared light) is irradiated. However, the type of ink ejected from the ink head 22 is not particularly limited, and may be, for example, a solvent or water-based ink. The color of each ink ejected from the four ink heads 22 is also not particularly limited, and may be a so-called process color ink or a special color ink such as clear ink or white ink. In this embodiment, the ink ejected from the ink head 22 is a process color ink. In the following description, the ink head 22 has a first ink head 22C that ejects cyan ink, a second ink head 22M that ejects magenta ink, a third ink head 22Y that ejects yellow ink, and a fourth ink head 22K that ejects black ink. Here, cyan ink is an example of a first color ink, and magenta ink is an example of a second color ink different from the first color.

In this embodiment, the ink head 22 communicates with an ink cartridge 23 housed in the case 11 via a flexible ink tube (not shown). The ink cartridge 23 contains ink of the color to be ejected from the ink head 22.

As shown in FIG. 2, the light irradiation device 26 is a device that irradiates light (e.g., ultraviolet or infrared light) onto the ink ejected from the ink head 22, and is provided on the carriage 20. In this embodiment, the light irradiation device 26 is provided on both the left and right sides of the carriage 20, but may be provided on only one side of the carriage 20. The light irradiation device 26 is configured to irradiate light onto the ink ejected onto the medium 5 supported by the support base 40.

The carriage movement mechanism 28 shown in FIG. 3 is a mechanism that moves the carriage 20 in the main scanning direction Y along the guide rail 18. In this embodiment, the carriage movement mechanism 28, although not shown, includes, for example, left and right pulleys provided around both left and right ends of the guide rail 18, a belt wound around the left and right pulleys, and a carriage motor connected to one of the pulleys. The carriage 20 is fixed to the belt. When the carriage motor is driven, one of the pulleys rotates, and the belt runs between the left and right pulleys. As a result, the carriage 20 moves in the main scanning direction Y along the guide rail 18, and the ink head 22 and the light irradiation device 26 also move in the main scanning direction Y.

In this embodiment, as shown in FIG. 2, the printer 10 includes a support table 40 and a support table movement mechanism 41. The support table 40 supports the medium 5. In other words, the medium 5 is placed on the support table 40. The support table 40 is disposed below the guide rail 18, the carriage 20, the ink head 22, and the light irradiation device 26.

The support table moving mechanism 41 is a mechanism that moves the support table 40 in the sub-scanning direction X. Although not shown, the support table moving mechanism 41 includes, for example, a pair of rails extending in the sub-scanning direction X, a sliding member slidably engaged with the pair of rails, and a feed motor connected to the sliding member. The support table 40 is placed on the sliding member. In this embodiment, the feed motor is driven to move the sliding member in the sub-scanning direction X along the pair of rails. The support table 40 moves in the sub-scanning direction X in conjunction with the movement of the sliding member. Note that in this embodiment, the support table moving mechanism 41 is configured to be able to raise and lower the support table 40.

In this embodiment, as shown in FIG. 3, the carriage movement mechanism 28 and the support platform movement mechanism 41 are collectively referred to as the movement mechanism 45. The movement mechanism 45 is a mechanism that moves the ink head 22 and the support platform 40 relatively in the main scanning direction Y and the sub-scanning direction X. The movement mechanism 45 has the carriage movement mechanism 28 and the support platform movement mechanism 41.

In this embodiment, the printer 10 is equipped with a control device 50. The control device 50 controls printing. The configuration of the control device 50 is not particularly limited. The control device 50 is, for example, a microcomputer. The control device 50 is equipped with, for example, an I/F, a CPU, a ROM, a RAM, and a storage device. The control device 50 is provided inside the case 11. However, the control device 50 may also be a computer or the like installed outside the case 11. In this case, the control device 50 is connected to the printer 10 so as to be able to communicate with it via a wire or wirelessly.

The control device 50 is communicatively and electrically connected to the movement mechanism 45. More specifically, the control device 50 is communicatively and electrically connected to the carriage movement mechanism 28 and the support platform movement mechanism 41. The control device 50 controls the movement of the carriage 20 in the main scanning direction Y by the carriage movement mechanism 28, and controls the movement of the support platform 40 in the sub-scanning direction X and its raising and lowering by the support platform movement mechanism 41. The control device 50 is also communicatively and electrically connected to the ink head 22 and the light irradiation device 26. The control device 50 controls the timing and amount of ink ejection by the ink head 22, and controls the light irradiation by the light irradiation device 26.

The configuration of the printer 10 according to this embodiment has been described above. As shown in FIG. 4, the medium 5 to be printed on is, for example, a medium 5 that is provided (for example, attached) to the surface of a three-dimensional object 8. After printing on this type of medium 5 by the printer 10, it is thermally shrunk along the shape of the surface of the three-dimensional object 8. Here, the printed portion of the portion of the medium 5 that has been thermally shrunk is also shrunk, so the amount of ink ejected per unit area of the medium 5 is greater than before it was shrunk by heat. As a result, the color of the ink tends to be darker in the printed portion of the portion of the medium 5 that has been thermally shrunk compared to before it was shrunk by heat. Therefore, in a medium 5 that is used by partially shrunk by heat in this way, if the amount of ink ejected per unit area is made uniform for all of the printing area AR10, the printed portion after it was shrunk by heat may have a shading effect, that is, color unevenness may occur. Therefore, in this embodiment, it is possible to make it difficult for color unevenness to occur in the printing performed on the medium 5 even after the medium 5 is shrunk by heat after printing.

As shown in FIG. 4, the three-dimensional object 8 to which the medium 5 partially shrunk by heat is attached has a predetermined shape on its surface. In other words, the three-dimensional object 8 has an uneven shape on its surface. The specific three-dimensional object 8 is not particularly limited. Examples of the three-dimensional object 8 include plastic bottles, food trays (e.g., plastic trays), bags (e.g., aluminum pouch-shaped retort bags), bottles (e.g., glass bottles), and containers (e.g., cosmetic containers, containers for household products such as detergents, cups, etc.). In the following, a plastic bottle will be described as an example of the three-dimensional object 8, as shown in FIG. 4.

The medium 5 provided along the surface of the three-dimensional object 8 is shrinkable. Here, the medium 5 shrinks when heat is applied. The temperature of the heat applied to the medium 5 is such that the ink ejected onto the medium 5 does not melt, for example, 60°C to 120°C. In this embodiment, the medium 5 is a so-called heat-shrinkable film. Examples of materials that form the medium 5 include polyvinyl chloride, polypropylene, polyethylene, polystyrene, polyolefin, and polyethylene terephthalate. In this embodiment, the medium 5 functions as a label that is attached to the surface of the plastic bottle, which is the three-dimensional object 8.

In this embodiment, the medium 5 has a printing area AR10. The printing area AR10 is an area onto which ink is ejected from the ink head 22. Note that in this embodiment, the printing area AR10 is a rectangular area, and may include an area surrounding the area onto which ink is actually ejected onto which ink is not ejected.

In this embodiment, in order to print the medium 5 that shrinks due to heat, as shown in FIG. 3, the control device 50 of the printer 10 includes a memory unit 52, a division unit 54, a determination unit 56, and a printing unit 58. The units 52, 54, 56, and 58 of the control device 50 may be configured by software or hardware. For example, the units 52, 54, 56, and 58 of the control device 50 may be executed by a processor or may be incorporated into a circuit. In this embodiment, the units 52, 54, 56, and 58 of the control device 50 are realized by a board or the like provided inside the case 11. However, some or all of the units 52, 54, 56, and 58 of the control device 50 may be realized by a computer installed outside the case 11. Specific control of the memory unit 52, division unit 54, determination unit 56, and printing unit 58 will be described later.

Next, the procedure for printing on a medium 5 that partially shrinks due to heat using the printer 10 according to this embodiment will be described with reference to the flowchart in FIG. 6.

First, in step S101 of FIG. 6, the division unit 54 of FIG. 3 divides the print area AR10 of the medium 5 into a plurality of divided areas AR20 based on the shrinkage rate R10 (see FIG. 7) for the medium 5, as shown in FIGS. 4 and 5. Here, the shrinkage rate R10 is the proportion of the medium 5 that shrinks due to heat. In this embodiment, as shown in FIG. 4, the medium 5 is shrunk by heat so as to conform to the shape of the surface of the three-dimensional object 8. Each portion of the medium 5 has a different shrinkage rate R10.

In this embodiment, the shrinkage rate R10 for each part of the medium 5 is stored in advance in the storage unit 52 in FIG. 3. Here, the intervals of the shrinkage rates R10 stored in the storage unit 52 are predetermined intervals. The predetermined intervals are, for example, 10%. That is, the shrinkage rates R10 for each part of the medium 5 corresponding to the shrinkage rates R10 in increments of 10% are stored in the storage unit 52. In this embodiment, the shrinkage rate R10 rounded off to the nearest 1 is stored in the storage unit 52 for each part of the medium 5. The shrinkage rate R10 for each part of the medium 5 is set in advance depending on the shape of the surface of the three-dimensional object 8 to which the medium 5 is to be attached. Therefore, before printing on the medium 5, the shrinkage rate R10 for each part of the medium 5 is already set, and information regarding the shrinkage rate R10 for each part of the medium 5 is stored in the storage unit 52 in advance.

In the medium 5 that is attached to a three-dimensional object 8, an example of which is a plastic bottle in Figure 4, the print area AR10 has a divided area AR21 with a shrinkage rate R10 of 0%, a divided area AR22 with a shrinkage rate R10 of 10%, and a divided area AR23 with a shrinkage rate R10 of 20%. Here, the shrinkage rate R10 of the portion of the medium 5 that is attached to the portion of the three-dimensional object 8, which is a plastic bottle, that has a shorter circumferential length is larger. Here, the divided areas AR21, AR22, and AR23 are in the order of shorter circumferential length of the three-dimensional object 8 to which they are attached.

The dividing unit 54 divides the printing area AR10 of the medium 5 at a predetermined interval based on the shrinkage rate R10 for each portion of the medium 5. Here, the predetermined interval is 10%, and the dividing unit 54 divides the printing area AR10 of the medium 5 into three divided areas AR21, AR22, and AR23. Note that the predetermined interval is not limited to 10%, and may be determined appropriately depending on the shape of the surface of the three-dimensional object 8. For example, if the difference in unevenness of the surface of the three-dimensional object 8 is large, the predetermined interval may be made small, and if the difference in unevenness of the surface of the three-dimensional object 8 is small or if the shape is flat, the predetermined interval may be made large.

Next, in step S103 in FIG. 6, the determination unit 56 in FIG. 3 determines the ink discharge amount per unit area (hereinafter referred to as divided ink discharge amount V20) for each divided area AR20 divided by the division unit 54, as shown in FIG. 7. Here, the smaller the shrinkage rate R10, i.e., the closer to 0%, the larger the divided ink discharge amount V20 is, and the larger the shrinkage rate R10, i.e., the farther from 0%, the smaller the divided ink discharge amount V20 is. In other words, based on the shrinkage rate R10 of the medium 5, the smaller the shrinkage rate, the larger the divided ink discharge amount V20 is, and the larger the shrinkage rate, the smaller the divided ink discharge amount V20 is. In this embodiment, the divided ink discharge amount V20 refers to the ink discharge amount for all colors of ink, such as cyan ink, magenta ink, yellow ink, and black ink.

The method of determining the divided ink ejection amount V20 for each divided area AR21, AR22, and AR23 is not particularly limited. In this embodiment, the memory unit 52 in FIG. 3 stores the reference ejection amount V10 as shown in FIG. 7 and the correction value C10 of the correction value table TB10. The reference ejection amount V10 is the ink ejection amount per unit area when the shrinkage rate R10 is 0%. Here, the reference ejection amount V10 is the ink ejection amount per unit area when the shrinkage rate R10 is 0% for all colors of ink, such as cyan ink, magenta ink, yellow ink, and black ink. The divided ink ejection amount V20 in each divided area AR20 is determined based on the reference ejection amount V10.

As shown in FIG. 7, the correction value table TB10 is a table that associates the shrinkage rate R10 with the correction value C10. The shrinkage rate R10 in the correction value table TB10 is the shrinkage rate R10 set in the divided area AR20. The correction value C10 is a value according to the shrinkage rate R10 for each divided area AR20. Here, one correction value C10 is associated with one shrinkage rate R10 among the shrinkage rates R10 at 10% intervals, i.e., at a predetermined interval. Here, the correction value C10 is set to a value in the range greater than 0 and equal to or less than 1. When the shrinkage rate R10 is 0%, the correction value C10 is 1.00, and the higher the shrinkage rate R10, the smaller the correction value C10 becomes, i.e., it is set so as to approach 0.

The determination unit 56 determines the divided ink ejection amount V20 for each divided area AR20 based on the reference ejection amount V10 and the correction value C10 according to the shrinkage rate R10 for each divided area AR20. In this embodiment, the determination unit 56 determines the divided ink ejection amount V20 for each divided area AR20 by multiplying the reference ejection amount V10 by the correction value C10. The divided ink ejection amount V20 for each divided area AR20 is calculated by the formula "reference ejection amount V10 x correction value C10". Here, as shown in FIG. 7, for example, the reference ejection amount V10 is 0.5 mg/ ^cm2 . The correction values C10 when the shrinkage rate R10 is 0%, 10%, and 20% are 1.00, 0.77, and 0.60, respectively. Therefore, the divided ink ejection amount V20 of the divided area AR21, whose shrinkage rate R10 is 0%, is 0.5 x 1.00 = 0.500 mg/ ^cm2 . The divided ink ejection amount V20 of the divided area AR22, whose shrinkage rate R10 is 10%, is 0.5 x 0.77 = 0.385 mg/ ^cm2 . The divided ink ejection amount V20 of the divided area AR23, whose shrinkage rate R10 is 20%, is 0.5 x 0.60 = 0.300 mg/ ^cm2 .

However, the divided ink ejection amount V20 does not have to be calculated by multiplying the reference ejection amount V10 and the correction value C10. For example, a predetermined formula may be stored in advance in the storage unit 52, and the divided ink ejection amount V20 may be calculated by substituting the reference ejection amount V10 and the correction value C10 into the predetermined formula. This predetermined formula may be a formula obtained by experiment or the like according to the shape of the three-dimensional object 8.

After determining the divided ink ejection amount V20 for each divided area AR20 in this manner, in step S105 in FIG. 6, the printing unit 58 in FIG. 3 prints on the printing area AR10 of the medium 5 supported by the support table 40. For example, the memory unit 52 stores print image data (not shown). The printing unit 58 prints an image based on the print image data on the printing area AR10. Here, the printing unit 58 first controls the carriage movement mechanism 28 (see FIG. 3) to move the ink head 22 in the main scanning direction Y. While the ink head 22 is moving in the main scanning direction Y, when it passes over the printing area AR10, the printing unit 58 ejects ink from the ink head 22 toward the printing area AR10 to print one line. After printing one line, the printing unit 58 controls the support table movement mechanism 41 (see FIG. 3) to move the support table 40 a predetermined distance in the sub-scanning direction X. After moving the support table 40 in the sub-scanning direction X, the next line is printed. By repeating the process of printing one line and moving the support table 40 in the sub-scanning direction X, the image included in the print image data can be printed in the printing area AR10.

In this embodiment, the ink ejection amount per unit area is adjusted for each divided area AR20. The printing unit 58 controls the ink ejection from the ink head 22 so that the ink ejection amount per unit area for each divided area AR20 becomes the divided ink ejection amount V20 (see FIG. 7) determined by the determination unit 56. Specifically, as shown in FIG. 7, the divided ink ejection amounts V20 for the divided areas AR21, AR22, and AR23 determined by the determination unit 56 are 0.500 mg/ ^cm2 , 0385 mg/ ^cm2 , and 0.300 mg/ ^cm2 , respectively. Therefore, the printing unit 58 controls the ink ejection amount from the ink head 22 so that the ink ejection amount for the divided area AR21 becomes 0.500 mg/ ^cm2 . Similarly, the printing unit 58 controls the amount of ink ejected from the ink head 22 so that the ink ejection amount for the divided area AR22 is 0.385 mg/ ^cm2 , and controls the amount of ink ejected from the ink head 22 so that the ink ejection amount for the divided area AR23 is 0.300 mg/ ^cm2 .

In this way, after printing of the print area AR10 of the medium 5 is completed, the medium 5 is partially shrunk by heat to conform to the shape of the surface of the three-dimensional object 8. Then, the medium 5, which has been partially shrunk by heat, is attached to the surface of the three-dimensional object 8.

As described above, in this embodiment, as shown in FIG. 4, the medium 5 is a medium provided on the surface of the three-dimensional object 8 and can be contracted by heat. The medium 5 has a printing area AR10 onto which ink is ejected, and is configured to be partially shrunk to correspond to the surface shape of the three-dimensional object 8. As shown in FIG. 3, the control device 50 includes a memory unit 52, a division unit 54, a determination unit 56, and a printing unit 58. The memory unit 52 stores a shrinkage rate R10 (see FIG. 7) for each part of the medium 5 that is preset to correspond to the surface shape of the three-dimensional object 8. The division unit 54 divides the printing area AR10 into a plurality of divided areas AR20 as shown in FIG. 5 based on the shrinkage rate R10 for each part of the medium 5 stored in the memory unit 52. As shown in FIG. 7, the determination unit 56 determines the divided ink ejection amount V20, which is the ink ejection amount per unit area, for each divided area AR20 based on the shrinkage rate R10 so that the ink ejection amount per unit area decreases as the shrinkage rate increases. The printing unit 58 ejects ink from the ink head 22 onto the printing area AR10 of the medium 5 so that the amount of ink ejected per unit area of each divided area AR20 is the divided ink ejection amount V20.

As a result, the greater the shrinkage rate R10 of the medium 5 in a portion of the medium 5, the greater the shrinkage of the medium 5, and the greater the shrinkage of the printed portion, so that the ink color shade in the printed portion becomes darker than the shade desired by the user (in other words, the shade of the image in the print image data printed on the medium 5). Therefore, in this embodiment, by reducing the amount of ink ejected per unit area during printing in the portion of the medium 5 that has a large shrinkage rate, the ink color shade can be made closer to the shade desired by the user after the medium 5 and printed portion have shrunk. Therefore, even if the medium 5 is partially shrunk after printing on a shrinkable medium 5, the shade of the printed portion can be made closer to the shade desired by the user, and color unevenness is less likely to occur.

In this embodiment, the memory unit 52 in FIG. 3 stores a reference ejection amount V10 and a correction value C10, as shown in FIG. 7. The reference ejection amount V10 is the ink ejection amount per unit area when the shrinkage rate R10 is 0%. The correction value C10 is a correction value for the reference ejection amount V10 according to the shrinkage rate R10 for each divided area AR20. The determination unit 56 determines the divided ink ejection amount V20 for each divided area AR20 based on the reference ejection amount V10 and the correction value C10 according to the shrinkage rate R10 for each divided area AR20. This makes it possible to determine the divided ink ejection amount V20 as the value obtained by correcting the reference ejection amount V10 with the correction value C10, making it easy to determine the divided ink ejection amount V20 for each divided area AR20 based on the reference ejection amount V10.

In this embodiment, as shown in FIG. 7, the correction value C10 is configured to be set to a smaller value in the range of greater than 0 and less than or equal to 1 as the shrinkage rate R10 increases. The determination unit 56 determines the divided ink ejection amount V20 for each divided area AR20 by multiplying the reference ejection amount V10 by the correction value C10 according to the shrinkage rate R10 for each divided area AR20. In this way, by using the simple method of multiplying the reference ejection amount V10 by the correction value C10, it is possible to reduce the divided ink ejection amount V20 for divided areas AR20 with a large shrinkage rate and increase the divided ink ejection amount V20 for divided areas AR20 with a small shrinkage rate.

<Other embodiments>
In the above embodiment, the print area AR10 is divided into a plurality of divided areas AR20 at a predetermined interval of shrinkage rate R10 (for example, an interval of 10% shrinkage rate R10). However, the interval of the shrinkage rate R10 for dividing the print area AR10 into divided areas AR20 may be changed depending on the shading of the image printed in the print area AR10 on the medium 5, or the interval of the shrinkage rate R10 may be changed depending on the shape of the three-dimensional object 8 to which the medium 5 is attached.

As shown in FIG. 8, for example, if there is a predetermined difference in shading in an image printed on the print area AR10 of medium 5A, in the darker parts of medium 5A, the change in shading is less noticeable even when the entire print area AR10 is shrunk by heat after an image is printed with a constant ink ejection amount. On the other hand, in the lighter parts of medium 5A, the change in shading is more noticeable when the entire print area AR10 is shrunk by heat after an image is printed with a constant ink ejection amount. Therefore, in this embodiment, in the lighter parts of medium 5A, the shrinkage rate R10 is further divided and the divided areas AR20 are more finely divided than in the darker parts of medium 5A.

In this embodiment, as shown in FIG. 8, the print area AR10 of the medium 5A has a first shaded area AR31 and a second shaded area AR32 that is lighter in color than the first shaded area AR31. Here, the average degree of shading in the second shaded area AR32 is lighter than the average degree of shading in the first shaded area AR31.

Here, the division unit 54 in FIG. 3 divides the first shaded area AR31 into a plurality of divided areas AR20 such that the shrinkage rate R10 is divided at a first division interval in the first shaded area AR31. The division unit 54 divides the second shaded area AR32 into a plurality of divided areas AR20 such that the shrinkage rate R10 is divided at a second division interval in the second shaded area AR32. Here, the second division interval is smaller than the first division interval. For example, the first division interval is an interval where the shrinkage rate R10 is 10%, and the second division interval is an interval where the shrinkage rate R10 is 5%. In this case, the first shaded area AR31 is divided into divided areas AR20 at intervals of 10% shrinkage rate R10. The second shaded area AR32 is divided into divided areas AR20 at intervals of 5% shrinkage rate R10.

In this embodiment, the second shaded area AR32 is an area that is lighter in color than the first shaded area AR31, and compared to the first shaded area AR31, the change in shade is more noticeable when it shrinks, and unevenness in the printed color is more likely to appear. Therefore, the second shaded area AR32 is divided into multiple divided areas AR20 so that the shrinkage rate R10 is divided more finely than the first shaded area AR31. In this way, even in parts of the medium 5A where the change in shade is more noticeable when it shrinks, the divided ink ejection amount V20 can be finely adjusted for each divided area AR20, making it possible to make unevenness in color less noticeable after the medium 5A is shrunk.

For example, in the case of a gourd-shaped three-dimensional object 8B as shown in FIG. 9, in the portion of the medium 5B that is attached to the flat portion of the surface of the three-dimensional object 8B where the difference in unevenness is small, even when the entire printing area AR10 is shrunk by heat after an image is printed with a constant ink ejection amount. On the other hand, in the portion of the medium 5B that is attached to the portion of the three-dimensional object 8B where the difference in unevenness is large, the change in shade is easily noticeable when the entire printing area AR10 is shrunk by heat after an image is printed with a constant ink ejection amount. Therefore, in this embodiment, in the portion of the medium 5B that is attached to the portion of the three-dimensional object 8B where the difference in unevenness is large, the shrinkage rate R10 is further divided into more finely divided areas AR20.

In this embodiment, as shown in FIG. 9, the printing area AR10 of the medium 5B has a first printing area AR41 and a second printing area AR42. In the first printing area AR41, the range from the upper limit to the lower limit of the shrinkage rate R10 per unit area is the first range. In the second printing area AR42, the range from the upper limit to the lower limit of the shrinkage rate R10 per unit area is the second range. Here, the second range is wider than the first range. In other words, the second printing area AR42 is attached to a portion of the three-dimensional object 8B that has a greater difference in surface unevenness compared to the first printing area AR41.

In this embodiment, the division unit 54 in FIG. 3 divides the first printing area AR41 into a plurality of divided areas AR20 such that the shrinkage rate R10 is divided at a third division interval in the first printing area AR41. The division unit 54 divides the second printing area AR42 into a plurality of divided areas AR20 such that the shrinkage rate R10 is divided at a fourth division interval in the second printing area AR42. Here, the fourth division interval is smaller than the third division interval. For example, the third division interval is an interval where the shrinkage rate R10 is 10%, and the fourth division interval is an interval where the shrinkage rate R10 is 5%. In this case, the first printing area AR41 is divided into divided areas AR20 at increments of 10% shrinkage rate R10. The second printing area AR42 is divided into divided areas AR20 at increments of 5% shrinkage rate R10.

In this embodiment, the second printed area AR42 is attached to a portion of the three-dimensional object 8B where the difference in unevenness is greater compared to the first printed area AR41, and therefore the change in shading is more noticeable when the area shrinks, and unevenness in the printed color is more likely to appear. For this reason, the second printed area AR42 is divided into multiple divided areas AR20 so that the shrinkage rate R10 is divided more finely compared to the first printed area AR41. This makes it possible to finely adjust the divided ink ejection amount V20 for each divided area AR20, even in portions of the medium 5B where the change in shading is more noticeable when the medium 5B shrinks, and therefore makes unevenness in color less noticeable after the medium 5B is shrunk.

In the above embodiment, the same divided ink ejection amount V20 was set for all colors of ink for each divided area AR20. However, the divided ink ejection amount V20 may be set for each color of ink in the same divided area AR20. That is, the divided ink ejection amount V20 may be determined for each of cyan ink, magenta ink, yellow ink, and black ink in the same divided area AR20.

Figure 10 is a diagram showing a correction table TB10C in another embodiment. In this case, the reference ejection amount V10 stored in the memory unit 52 in Figure 3 has a first reference ejection amount V11, which is the ejection amount of cyan ink per unit area when the shrinkage rate R10 is 0%, and a second reference ejection amount V12, which is the ejection amount of magenta ink per unit area when the shrinkage rate R10 is 0%, as shown in Figure 10. Furthermore, the reference ejection amount V10 has a third reference ejection amount V13, which is the ejection amount of yellow ink per unit area when the shrinkage rate R10 is 0%, and a fourth reference ejection amount V14, which is the ejection amount of black ink per unit area when the shrinkage rate R10 is 0%.

In this embodiment, as shown in FIG. 10, a correction value C10 is set for each of cyan ink, magenta ink, yellow ink, and black ink for each shrinkage rate R10. Here, the correction values for cyan ink, magenta ink, yellow ink, and black ink are the first correction value C11, the second correction value C12, the third correction value C13, and the fourth correction value C14, respectively. The correction value C10 has the first correction value C11, the second correction value C12, the third correction value C13, and the fourth correction value C14. The first correction value C11, the second correction value C12, the third correction value C13, and the fourth correction value C14 are correction values for cyan ink, magenta ink, yellow ink, and black ink according to the shrinkage rate R10 for each divided area AR20, respectively. Additionally, the first correction value C11 to the fourth correction value C14 are correction values for the first reference discharge amount V11 to the fourth reference discharge amount V14, respectively. For the same shrinkage rate R10, the first correction value C11 to the fourth correction value C14 may all be the same value, or some or all of them may be different values.

In this embodiment, the determination unit 56 in FIG. 3 determines the divided ink ejection amount V20 for cyan ink for each divided area AR20 by multiplying the first standard ejection amount V11 and the first correction value C11 based on the first standard ejection amount V11 and the first correction value C11 corresponding to the shrinkage rate R10 for each divided area AR20, and determines the divided ink ejection amount V20 for magenta ink for each divided area AR20 by multiplying the second standard ejection amount V12 and the second correction value C12 based on the second standard ejection amount V12 and the second correction value C12 corresponding to the shrinkage rate R10 for each divided area AR20. Similarly, the determination unit 56 determines the divided ink ejection amount V20 for yellow ink for each divided area AR20 by multiplying the third standard ejection amount V13 and the third correction value C13 according to the shrinkage rate R10 for each divided area AR20, and determines the divided ink ejection amount V20 for black ink for each divided area AR20 by multiplying the fourth standard ejection amount V14 and the fourth correction value C14 according to the shrinkage rate R10 for each divided area AR20.

As described above, in this embodiment, even for the same divided area AR20, a correction value C10 (first correction value C11 to fourth correction value C14) is set for each ink color, and the divided ink ejection amount V20 is determined for each ink color. This makes it possible to adjust the divided ink ejection amount V20 for each ink color according to the characteristics of the ink color, making color unevenness less noticeable after the medium 5B is shrunk.

In each of the above embodiments, the medium 5, 5A, 5B (hereinafter simply referred to as the medium 5) was capable of shrinking due to heat. However, the medium 5 may be capable of expanding. For example, the medium 5 may expand when heat is applied. In this case, in each of the above embodiments, shrinkage is replaced with expansion. For example, the shrinkage rate R10 is replaced with the expansion rate R10. In this case, the medium 5 has a printing area AR10 into which ink is ejected, and is configured to expand to correspond to the surface shape of the three-dimensional object 8. The memory unit 52 of the control device 50 stores the expansion rate R10 for each part of the medium 5 that is preset to correspond to the surface shape of the three-dimensional object 8. The division unit 54 divides the printing area AR10 into a plurality of divided areas AR20 based on the expansion rate R10 for each part of the medium 5 stored in the memory unit 52. The determination unit 56 determines the divided ink ejection amount V20 per unit area for each divided area AR20 based on the expansion rate R10 so that the larger the expansion rate, the larger the ink ejection amount per unit area. In this embodiment, the correction value C10 is in the range of 1 or more, and the larger the expansion rate R10, the larger the correction value C10. In other words, the larger the expansion rate R10, the greater the amount of ink ejected in the portion of the medium 5.

Even in this embodiment, the greater the expansion rate R10 of the portion of the medium 5, the greater the expansion of the printed portion as the medium 5 expands, and the ink color shade in the printed portion becomes lighter than the shade desired by the user. Therefore, by increasing the amount of ink ejected per unit area during printing in the portion of the medium 5 that has a greater expansion rate, the ink color shade can be made closer to the shade desired by the user after the medium 5 and printed portion have expanded. Therefore, even if the medium 5 is expanded after printing on the expandable medium 5, the shade of the printed portion can be made closer to the shade desired by the user, and color unevenness is less likely to occur.

In this embodiment, the correction value C10 is configured to be set to a larger value in the range of 1 or more as the expansion rate R10 increases. The determination unit 56 determines the divided ink ejection amount V20 for each divided area AR20 by multiplying the standard ejection amount V10 and the correction value C10 based on the standard ejection amount V10 and the correction value C10 corresponding to the expansion rate R10 for each divided area AR20. In this way, with the simple method of multiplying the standard ejection amount V10 and the correction value C10, it is possible to increase the divided ink ejection amount V20 for divided areas AR20 with a large expansion rate and decrease the divided ink ejection amount V20 for divided areas AR20 with a small expansion rate.

5 Medium 8 Three-dimensional object 22 Ink head 40 Support base 50 Control device 52 Memory unit 54 Division unit 56 Determination unit 58 Printing unit AR10 Printing area AR20 Division area C10 Correction value R10 Contraction rate (expansion rate)
V10 Standard ejection amount V20 Divided ink ejection amount

Claims (4)

A medium is provided along a surface of a three-dimensional object, and a support base supports the medium, which can be contracted or expanded;
an ink head that ejects ink onto the medium supported by the support base;
A control device;
Equipped with
the medium has a printing area onto which ink is ejected, and is configured to contract or expand so as to correspond to a surface shape of the three-dimensional object;
The control device includes:
a storage unit in which a contraction/expansion rate for each portion of the medium that is preset to correspond to the surface shape of the three-dimensional object is stored;
a dividing unit that divides the print area into a plurality of divided areas based on the contraction/expansion rate for each portion of the medium stored in the storage unit;
a determination unit that determines a divided ink ejection amount, which is an ink ejection amount per unit area, for each of the divided areas based on the contraction/expansion rate, such that the greater the contraction rate, the smaller the ink ejection amount per unit area, and the greater the expansion rate, the larger the ink ejection amount per unit area;
a printing unit that ejects ink from the ink head onto the printing area of the medium so that an ink ejection amount per unit area for each of the divided areas is the divided ink ejection amount;
Equipped with
The ink head includes:
a first ink head that ejects ink of a first color;
a second ink head that ejects ink of a second color different from the first color;
having
The storage unit includes:
a first reference ejection amount, which is an ejection amount of the ink of the first color per unit area when the contraction/expansion rate is 0%;
a second reference ejection amount, which is the ejection amount of the ink of the second color per unit area when the contraction/expansion rate is 0%;
a first correction value for the first reference ejection amount of the first color ink according to the contraction/expansion rate for each of the divided areas;
a second correction value for the second reference ejection amount of the ink of the second color according to the contraction/expansion rate for each of the divided areas;
is stored,
the determination unit determines the divided ink ejection amount of the first color ink for each divided area based on the first standard ejection amount and the first correction value corresponding to the contraction/expansion rate for each divided area, and determines the divided ink ejection amount of the second color ink for each divided area based on the second standard ejection amount and the second correction value corresponding to the contraction/expansion rate for each divided area;
The first and second correction values for a given shrinkage/expansion rate are different values . the first correction value and the second correction value are configured such that, as the contraction rate increases, the first correction value and the second correction value are set to smaller values in a range of 0 to 1, and as the expansion rate increases, the first correction value and the second correction value are set to larger values in a range of 1 or more,
The printer according to claim 1 , wherein the determination unit determines the divided ink ejection amount of the first color ink for each divided area by multiplying the first standard ejection amount by the first correction value corresponding to the contraction/expansion rate for each divided area , and determines the divided ink ejection amount of the second color ink for each divided area by multiplying the second standard ejection amount by the second correction value corresponding to the contraction/expansion rate for each divided area . A medium is provided along a surface of a three-dimensional object, and a support base supports the medium, which can be contracted or expanded;
an ink head that ejects ink onto the medium supported by the support base;
A control device;
Equipped with
the medium has a printing area onto which ink is ejected, and is configured to contract or expand so as to correspond to a surface shape of the three-dimensional object;
The control device includes:
a storage unit in which a contraction/expansion rate for each portion of the medium that is preset to correspond to the surface shape of the three-dimensional object is stored;
a dividing unit that divides the print area into a plurality of divided areas based on the contraction/expansion rate for each portion of the medium stored in the storage unit;
a determination unit that determines a divided ink ejection amount, which is an ink ejection amount per unit area, for each of the divided areas based on the contraction/expansion rate, such that the greater the contraction rate, the smaller the ink ejection amount per unit area, and the greater the expansion rate, the larger the ink ejection amount per unit area;
a printing unit that ejects ink from the ink head onto the printing area of the medium so that an ink ejection amount per unit area for each of the divided areas is the divided ink ejection amount;
Equipped with
The print area of the medium is:
A first shading area;
a second shaded area that is lighter in color than the first shaded area;
having
The dividing unit divides the first shaded area into a plurality of divided areas so that the contraction/expansion rate is divided at a first division interval in the first shaded area, and divides the second shaded area into a plurality of divided areas so that the contraction/expansion rate is divided at a second division interval that is smaller than the first division interval in the second shaded area. A medium is provided along a surface of a three-dimensional object, and a support base supports the medium, which can be contracted or expanded;
an ink head that ejects ink onto the medium supported by the support base;
A control device;
Equipped with
the medium has a printing area onto which ink is ejected, and is configured to contract or expand so as to correspond to a surface shape of the three-dimensional object;
The control device includes:
a storage unit in which a contraction/expansion rate for each portion of the medium that is preset to correspond to the surface shape of the three-dimensional object is stored;
a dividing unit that divides the print area into a plurality of divided areas based on the contraction/expansion rate for each portion of the medium stored in the storage unit;
a determination unit that determines a divided ink ejection amount, which is an ink ejection amount per unit area, for each of the divided areas based on the contraction/expansion rate, such that the greater the contraction rate, the smaller the ink ejection amount per unit area, and the greater the expansion rate, the larger the ink ejection amount per unit area;
a printing unit that ejects ink from the ink head onto the printing area of the medium so that an ink ejection amount per unit area for each of the divided areas is the divided ink ejection amount;
Equipped with
The print area of the medium is:
a first printing area, the range from the upper limit to the lower limit of the contraction/expansion rate per unit area being a first range;
a second printing area in which the range from the upper limit to the lower limit of the contraction/expansion rate per unit area is a second range that is wider than the first range;
having
The dividing unit divides the first printing area into a plurality of divided areas so that, in the first printing area, the shrinkage/expansion rate is divided at a third division interval, and divides the second printing area into a plurality of divided areas so that, in the second printing area, the shrinkage/ expansion rate is divided at a fourth division interval that is smaller than the third division interval.

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