inkjet printer

Abstract

An inkjet printer 10 includes: a support base 20 that extends in a scanning direction Y and supports a recording medium 5; a carriage 40 that is disposed facing the support base 20; a carriage moving device 50 that moves the carriage 40 toward a first scanning direction Y1 that is one direction of the scanning direction Y and toward a second scanning direction Y2 that is the other direction of the scanning direction Y; a recording head 60 that is provided to the carriage 40 and discharges photocurable ink toward the support base 20; a first light emitting device 70L which is fixed to the carriage 40 such that the first light emitting device is located on the first scanning direction Y1 side with respect to the recording head 60 and emits light for curing the ink toward the support base 20; and a second light emitting device 70R which is fixed to the carriage 40 such that the second light emitting device is located on the second scanning direction Y2 side with respect to the recording head 60 and which emits light for curing the ink toward the support base 20. In the scanning direction Y, a distance L1 between the first light emitting device 70L and the recording head 60 is longer than a distance L2 between the second light emitting device 70R and the recording head 60.

Description

Technical Field

[0001] The present invention relates to an inkjet printer.

Background Art

[0002] Conventionally, a printer has been known that includes an ink head that discharges photocurable ink onto a recording medium and a light irradiation device that irradiates light for curing the ink. For example, Patent Document 1 discloses an inkjet printer including a table on which a recording medium is placed, a carriage, a plurality of inkjet heads mounted on the carriage that discharge photocurable ink, a pair of light irradiation devices arranged on the left and right sides of the carriage, and a carriage movement mechanism that moves the carriage in the main scanning direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A part of the light irradiated from the light irradiation device is reflected one or more times by the recording medium and reaches the recording head. Here, multiple reflections mean that the reflected light by the recording medium is reflected by another member and irradiated onto the recording medium again, and then reflected again by the recording medium. Hereinafter, one or more reflections by the recording medium are also simply referred to as "reflection by the recording medium". The reflected light reaching the recording head may thicken or cure the ink in the nozzles of the recording head or the ink adhering to the nozzle surface. Therefore, it is desirable to reduce the reflected light reaching the recording head.

[0005] Regarding the scanning direction, which is the direction of movement of the carriage and recording head, increasing the distance between the light irradiator and the recording head can reduce the amount of reflected light reaching the recording head. However, such a configuration results in a longer scanning length for the inkjet printer.

[0006] The present invention has been made in view of the above, and its objective is to provide an inkjet printer that can simultaneously suppress reflected light irradiated onto the recording head and suppress the length of the scanning direction of the inkjet printer. [Means for solving the problem]

[0007] The inkjet printer disclosed herein comprises: a support base extending in a predetermined scanning direction and supporting a recording medium; a carriage provided opposite the support base; a carriage moving device for moving the carriage in a first scanning direction, which is one of the scanning directions, and a second scanning direction, which is the other of the scanning directions; a recording head provided on the carriage for ejecting photocurable ink toward the support base; a first light irradiation device fixed to the carriage so as to be positioned in the first scanning direction relative to the recording head, and irradiating the support base with light to cure the ink; and a second light irradiation device fixed to the carriage so as to be positioned in the second scanning direction relative to the recording head, and irradiating the support base with light to cure the ink. With respect to the scanning direction, the distance between the first light irradiation device and the recording head is longer than the distance between the second light irradiation device and the recording head.

[0008] In the above-described inkjet printer, the distance between the first light irradiator and the recording head is greater than that between the second light irradiator and the recording head in the scanning direction. This makes it possible to reduce the amount of reflected light that reaches the recording head after being irradiated by the first light irradiator and reflected by the recording medium, compared to the amount of reflected light that reaches the recording head after being irradiated by the second light irradiator. As a result, the amount of reflected light irradiated onto the recording head can be reduced. Furthermore, in the above-described inkjet printer, the distance between the second light irradiator and the recording head can be made shorter than the distance between the first light irradiator and the recording head in the scanning direction. This makes it possible to shorten the scanning length of the inkjet printer. In the above-described inkjet printer, it is possible to achieve both suppression of reflected light irradiated onto the recording head and a reduction in the scanning length of the inkjet printer. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view showing a printer according to one embodiment. [Figure 2] This is a front view showing the printer with the front cover open. [Figure 3] This is a front view of the carriage. [Figure 4] This is a plan view showing the underside of the carriage. [Figure 5] This is a block diagram of a printer. [Figure 6] This is a front view of the carriage schematically illustrating the light reflection state during printing in the first printing mode. [Figure 7] This is a schematic front view of the carriage showing the light reflection state when printing on a transparent recording medium in the first printing mode. [Figure 8] This is a front view of the carriage schematically illustrating the light reflection state during printing using the second printing mode. [Figure 9] This graph shows an example of the results of measuring the amount of reflected light reaching the recording head. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below 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 components and parts that perform the same function, and redundant explanations are omitted or simplified as appropriate.

[0011] [Printer configuration] Figure 1 is a perspective view showing an inkjet printer (hereinafter referred to as "printer") 10 according to one embodiment. In the following description, unless otherwise specified, when viewing the printer 10 from the front, the direction away from the printer 10 is considered the front, and the direction towards the printer 10 is considered the rear. Left, right, up, and down refer to the left, right, up, and down directions when viewing the printer 10 from the front, respectively. Also, the symbols F, Rr, L, R, U, and D in the drawing refer to the front, rear, left, right, up, and down, respectively. The symbol Y in the drawing indicates the main scanning direction. The main scanning direction Y is the left-right direction. The symbol X indicates the sub-scanning direction. The sub-scanning direction X is the front-back direction. The symbol Z indicates the up-down direction. The main scanning direction Y, sub-scanning direction X, and up-down direction Z are orthogonal to each other. However, the above directions are merely defined for the convenience of explanation and do not limit the installation configuration of the printer 10 in any way, nor do they limit the present invention in any way.

[0012] In this embodiment, the printer 10 is an inkjet printer. In this embodiment, "inkjet method" refers to various conventionally known inkjet methods, including various continuous methods such as binary deflection methods or continuous deflection methods, and various on-demand methods such as thermal methods or piezoelectric element methods.

[0013] As shown in Figure 1, the printer 10 is formed in a box shape. In this embodiment, the printer 10 comprises a case 11 and a front cover 12. Figure 2 is a front view of the printer 10 with the front cover 12 open. As shown in Figure 2, an opening is formed in the front of the case 11. The front cover 12 is provided so as to be able to open and close the opening of the case 11. Here, the front cover 12 is supported by the case 11 so as to be able to rotate around its rear end as an axis. The front cover 12 is provided with a window portion 12a. The window portion 12a is formed, for example, from a transparent acrylic plate. The user can see the internal space of the case 11 through the window portion 12a.

[0014] As shown in Figure 2, the internal space of the printer 10 is equipped with a flatbed 20, a bed moving device 30, a carriage 40, a carriage moving device 50, a recording head 60, a light irradiation device 70, and a control device 100 (see Figure 5).

[0015] The flatbed 20 is a support base for supporting the recording medium 5. The printer 10 according to this embodiment is a so-called flatbed type printer. The flatbed 20 is a flat plate-shaped member. The flatbed 20 extends in the main scanning direction Y and the sub-scanning direction X. The flatbed 20 is oriented in the vertical direction Z. The recording medium 5 is placed on the upper surface of the flatbed 20. The shape of the recording medium 5 is not particularly limited and may have various three-dimensional shapes in addition to being flat. The material of the recording medium 5 is also not particularly limited and may be, for example, wood, metal, glass, paper, cloth, etc. The flatbed 20 is positioned approximately in the center of the main scanning direction Y in the internal space of the case 11.

[0016] Below the flat bed 20, a bed moving device 30 is arranged. The bed moving device 30 moves the flat bed 20 in the sub-scanning direction X and the vertical direction Z. The flat bed 20 is supported from below by the bed moving device 30. The bed moving device 30 includes a sub-scanning direction moving mechanism 30X and a vertical direction moving mechanism 30Z. The vertical direction moving mechanism 30Z supports the flat bed 20 and moves it in the vertical direction Z. The vertical direction moving mechanism 30Z is supported from below by the sub-scanning direction moving mechanism 30X. The sub-scanning direction moving mechanism 30X supports the vertical direction moving mechanism 30Z and moves it in the sub-scanning direction X. However, the configuration of the bed moving device 30 is not limited. For example, the sub-scanning direction moving mechanism 30X and the vertical direction moving mechanism 30Z may have the opposite vertical positional relationship.

[0017] The carriage 40 is provided so as to face the flat bed 20. Here, the carriage 40 is provided above the flat bed 20. The carriage 40 mounts the recording head 60. Also, a light irradiation device 70 is fixed to the carriage 40 via a carriage base 45. FIG. 3 is a front view of the carriage 40. FIG. 4 is a plan view showing the lower surface of the carriage 40. As shown in FIGS. 3 and 4, the carriage base 45 is configured in a flat plate shape extending in the main scanning direction Y and the vertical direction Z. The carriage 40 is fixed to the front surface of the carriage base 45. The carriage base 45 supports the carriage 40. The carriage 40 includes a bottom plate 41 to which the recording head 60 is mounted and a carriage cover 42 that houses the recording head 60.

[0018] As shown in FIG. 4, the bottom plate 41 is configured in a flat plate shape and extends in the main scanning direction Y and the sub-scanning direction X. The bottom plate 41 constitutes the lower surface of the carriage 40 and faces the flat bed 20. Mounting holes 41L and 41R for mounting the recording head 60 are formed in the bottom plate 41. As will be described later, the recording head 60 includes two ink heads, i.e., a first ink head 61 and a second ink head 62 here, and the mounting holes 41L and 41R include a mounting hole 41L for mounting the first ink head 61 and a mounting hole 41R for mounting the second ink head 62. The carriage cover 42 is configured in a box shape. Inside the carriage cover 42, in addition to the upper part of the recording head 60, for example, ink tubes, dampers, etc. not shown in the figure are accommodated. However, the members mounted on the carriage 40 are not particularly limited.

[0019] The carriage moving device 50 moves the carriage 40 in the main scanning direction Y. Hereinafter, the left side in the main scanning direction Y is also referred to as the first main scanning direction Y1, and the right side in the main scanning direction Y is also referred to as the second main scanning direction Y2. The carriage moving device 50 moves the carriage 40 in the first main scanning direction Y1, which is one direction in the main scanning direction Y, and in the second main scanning direction Y2, which is the other direction. As shown in FIG. 2, the carriage moving device 50 includes a guide rail 51, a belt 52, left and right pulleys not shown in the figure, and a carriage motor 53.

[0020] As shown in Figure 2, the guide rail 51 extends in the main scanning direction Y. The carriage 40 is slidably engaged with the guide rail 51 via the carriage base 45. As shown in Figure 4, the carriage base 45 includes a linear motion block 46 that is slidably engaged with the guide rail 51. An endless belt 52 (see Figure 2) is fixed to the carriage base 45. The belt 52 is wrapped around pulleys (not shown) provided on the right and left sides of the guide rail 51. A carriage motor 53 is attached to one of the pulleys. When the carriage motor 53 is driven, the pulley rotates and the belt 52 moves. As a result, the carriage 40 moves along the guide rail 51 in the main scanning direction Y together with the carriage base 45.

[0021] The recording head 60 is mounted on the carriage 40 and ejects photocurable ink toward the flatbed 20. In this embodiment, the ink ejected from the recording head 60 is photocurable ink. In this case, the photocurable ink is an ultraviolet-curable ink that hardens when irradiated with ultraviolet light. The components and properties of the photocurable ink are not particularly limited. In this embodiment, the recording head 60 ejects the photocurable ink toward the downward. The recording head 60 faces the flatbed 20.

[0022] As shown in Figure 4, the recording head 60 comprises a first ink head 61 and a second ink head 62. Both the first ink head 61 and the second ink head 62 extend in the sub-scanning direction X. The first ink head 61 and the second ink head 62 are arranged side by side in the main scanning direction Y. Here, the first ink head 61 is positioned to the left (Y1) of the second ink head 62 in the first main scanning direction. In this embodiment, the first ink head 61 and the second ink head 62 are offset in the sub-scanning direction X. However, the first ink head 61 and the second ink head 62 partially overlap with respect to the sub-scanning direction X. Here, the first ink head 61 is positioned behind the second ink head 62.

[0023] In the following, if a component is located to the left of the end of the recording head 60 on the first main scanning direction Y1 side (here, the left end), we will say that it is "located in the first main scanning direction Y1 relative to the recording head 60". In this embodiment, if a component is "located in the first main scanning direction Y1 relative to the recording head 60", it means that the component is located to the left of the end of the first ink head 61 on the first main scanning direction Y1 side (the left end). Similarly, in the following, if a component is located to the right of the end of the recording head 60 on the second main scanning direction Y2 side (here, the right end), we will say that it is "located in the second main scanning direction Y2 relative to the recording head 60". In this embodiment, if a component is "located in the second main scanning direction Y2 relative to the recording head 60", it means that the component is located to the right of the end of the second ink head 62 on the second main scanning direction Y2 side (the right end).

[0024] The number of ink heads constituting the recording head 60 is not limited. The recording head 60 may, for example, consist of one ink head. If the recording head 60 consists of multiple ink heads, the arrangement of the multiple ink heads is not limited. For example, the multiple ink heads may be arranged so that their positions in the sub-scanning direction X are aligned.

[0025] The recording head 60 is positioned in the center of the carriage 40 with respect to the main scanning direction Y. The center line CL1 of the recording head 60 in the main scanning direction Y (here, the center line between the left edge of the first ink head 61 and the right edge of the second ink head 62) and the center line CL2 of the carriage 40 in the main scanning direction Y (here, the center lines between the left and right sides of the carriage cover 42) coincide or approximately coincide.

[0026] The first ink head 61 is equipped with multiple nozzles 61N. Each nozzle 61N is a fine hole from which ink is ejected. Each of the multiple nozzles 61N communicates with a pressure chamber in which ink is stored. The ink is ejected from the nozzles 61N when the pressure chamber expands / contracts, for example, by the drive of a piezoelectric element. The multiple nozzles 61N are formed on the lower surface of the first ink head 61 (hereinafter also referred to as the nozzle surface 61S), and ink is ejected downward from the multiple nozzles 61N.

[0027] Multiple nozzles 61N form multiple nozzle rows 61W1, 61W2, 61P, and 61CL. Each of the nozzle rows 61W1, 61W2, 61P, and 61CL is composed of multiple nozzles 61N arranged in the sub-scanning direction X. The multiple nozzle rows 61W1, 61W2, 61P, and 61CL are arranged in the main scanning direction Y. White ink is ejected from the nozzles 61N of nozzle rows 61W1 and 61W2. Primer ink is ejected from the nozzles 61N of nozzle row 61P. Clear ink is ejected from the nozzles 61N of nozzle row 61CL. Special color ink that gives a special visual effect to the image is ejected from the nozzles 61N of the first ink head 61.

[0028] The second ink head 62 is equipped with multiple nozzles 62N. The multiple nozzles 62N are formed on the nozzle surface 62S (bottom surface) of the second ink head 62, and ink is ejected downwards from the multiple nozzles 62N. The multiple nozzles 62N form multiple nozzle rows 62C, 62M, 62Y, and 62K. The multiple nozzle rows 62C, 62M, 62Y, and 62K are arranged in the main scanning direction Y. Cyan ink is ejected from the nozzles 62N of nozzle row 62C. Magenta ink is ejected from the nozzles 62N of nozzle row 62M. Yellow ink is ejected from the nozzles 62N of nozzle row 62Y. Black ink is ejected from the nozzles 62N of nozzle row 62K. Color ink is ejected from the nozzles 62N of the second ink head 62. However, the types of ink ejected from the first ink head 61 and the second ink head 62, the order of the inks, etc., are not particularly limited.

[0029] The light irradiation device 70 includes a first light irradiation device 70L fixed to the carriage 40 so as to be located to the left of the first main scanning direction Y1 relative to the recording head 60, and a second light irradiation device 70R fixed to the carriage 40 so as to be located to the right of the second main scanning direction Y2 relative to the recording head 60. In this embodiment, the printer 10 is equipped with a carriage base 45 as a holding member fixed to the carriage 40 and holding the first light irradiation device 70L and the second light irradiation device 70R. A portion of the carriage base 45 protrudes beyond the carriage 40 in the first main scanning direction Y1 relative to the carriage 40 and holds the first light irradiation device 70L in the first main scanning direction Y1 relative to the carriage 40. Hereinafter, this portion of the carriage base 45 will also be referred to as the first holding portion 45L. Another portion of the carriage base 45 protrudes beyond the carriage 40 in the second main scanning direction Y2 relative to the carriage 40 and holds the second light irradiation device 70R in the second main scanning direction Y2 relative to the carriage 40. Hereafter, this part of the carriage base 45 will also be referred to as the second retaining part 45R.

[0030] The first light irradiation device 70L and the second light irradiation device 70R each irradiate the flatbed 20 with light to cure the ink. As shown in Figure 4, the first light irradiation device 70L includes a light source 71L that generates light and an irradiation port 72L that irradiates the light from the light source 71L outwards. The light source 71L is composed of, for example, multiple ultraviolet irradiation LEDs. The irradiation port 72L is an opening with a cover that allows light to pass through. However, the irradiation port 72L may be a simple opening that is not covered by a cover or the like. The irradiation port 72L faces the flatbed 20. The irradiation port 72L opens downwards. The irradiation port 72L extends in the sub-scanning direction X. The front end of the irradiation port 72L is located in front of the foremost nozzle 62N of the second ink head 62. The rear end of the irradiation port 72L is located behind the rearmost nozzle 61N of the first ink head 61.

[0031] The second light irradiation device 70R is configured in the same way as the first light irradiation device 70L. The second light irradiation device 70R includes a light source 71R that generates light and an irradiation port 72R that irradiates the light from the light source 71R outwards.

[0032] In this embodiment, with respect to the main scanning direction Y, the distance L1 between the first light irradiator 70L and the recording head 60 is longer than the distance L2 between the second light irradiator 70R and the recording head 60. The distance L1 between the first light irradiator 70L and the recording head 60 is the distance between the end of the first light irradiator 70L on the second main scanning direction Y2 side (here, the right end) and the end of the recording head 60 on the first main scanning direction Y1 side (here, the left end of the first ink head 61). Similarly, the distance L2 between the second light irradiator 70R and the recording head 60 is the distance between the end of the second light irradiator 70R on the first main scanning direction Y1 side (here, the left end) and the end of the recording head 60 on the second main scanning direction Y2 side (here, the right end of the second ink head 62). In this embodiment, the printer 10 is configured such that, with respect to the main scanning direction Y, the distance between the first light irradiator 70L and the recording head 60 is greater than that between the first light irradiator 70L and the second light irradiator 70R.

[0033] In this embodiment, the length of the first holding unit 45L in the main scanning direction Y is made different from the length of the second holding unit 45R in the main scanning direction Y, thereby positioning the first light irradiator 70L further from the recording head 60 than the second light irradiator 70R. As shown in Figure 3, with respect to the main scanning direction Y, the length L3 of the portion of the first holding unit 45L between the carriage 40 and the first light irradiator 70L is longer than the length L4 of the portion of the second holding unit 45R between the carriage 40 and the second light irradiator 70R. The distance L3 is preferably 1.5 times or more the distance L4. However, from the viewpoint of suppressing the length of the printer 10 in the main scanning direction Y, the distance L3 is preferably 3 times or less the distance L4. The distance L1 of the first light irradiator 70L from the recording head 60 is preferably 1.2 times or more the distance L4 of the second light irradiator 70R from the recording head 60. The distance L1 is preferably 3 times or less the distance L2. However, the ratio of distance L3 to distance L4, and the ratio of distance L1 to distance L2, only need to be greater than "1" and are not limited to any greater value.

[0034] As shown in Figure 3, a carriage lifting lever 55 is provided to the left of the carriage 40 (in the first main scanning direction Y1). The carriage lifting lever 55 is located between the carriage 40 and the first light irradiation device 70L. The carriage lifting lever 55 is used to raise and lower the carriage base 45 and adjust its height. For example, if the thickness of the recording medium 5 changes, the distance from the irradiation ports 72L and 72R of the first light irradiation device 70L and the second light irradiation device 70R to the top surface of the recording medium 5 changes. By operating the carriage lifting lever 55, the carriage base 45 can be raised and lowered to adjust the distance from the irradiation ports 72L and 72R of the first light irradiation device 70L and the second light irradiation device 70R to the top surface of the recording medium 5. The carriage lifting lever 55 is located to the left of the carriage 40, where the distance between the carriage 40 and the light irradiation device 70 in the main scanning direction Y is wider. This makes it easier to operate the carriage lifting lever 55.

[0035] Figure 5 is a block diagram of the printer 10. As shown in Figure 5, the control device 100 is electrically connected to the sub-scanning direction movement mechanism 30X, the vertical direction movement mechanism 30Z, the carriage motor 53, the first ink head 61 and the second ink head 62 (recording head 60), the light source 71L of the first light irradiation device 70L, and the light source 71R of the second light irradiation device 70R, and controls their operation. The control device 100 is, for example, a computer connected to the printer 10, and may include a central processing unit (hereinafter referred to as CPU), ROM storing programs executed by the CPU, RAM, etc. Each part of the control device 100 may be composed of software or hardware. Also, each part may be a processor or a circuit. The configuration of the control device 100 is not particularly limited.

[0036] As shown in Figure 5, the control device 100 includes a media input unit 101, a mode selection unit 102, a first print control unit 103, and a second print control unit 104. The control device 100 may include other control units, but their description and illustration are omitted here.

[0037] The media input unit 101 receives input indicating the type of recording medium 5. Here, the media input unit 101 recognizes the input if a predetermined type of recording medium 5 is received. In this case, the predetermined type of recording medium 5 is a transparent recording medium 5. The method for identifying the transparent recording medium 5 is not particularly limited, but for example, the printer 10 may have transparent recording mediums 5 such as "transparent acrylic" registered for selection. Alternatively, for example, the media input unit 101 may be configured so that the user can input that the recording medium 5 is transparent.

[0038] The mode selection unit 102 is configured to allow selection of a printing mode from a plurality of printing modes, including a first printing mode and a second printing mode. The first printing mode is a printing mode for printing on an opaque recording medium 5. The second printing mode is a printing mode for printing on a transparent recording medium 5. The mode selection unit 102 is configured to select the second printing mode when the type of recording medium 5 input to the media input unit 101 is a predetermined type, in this case a transparent recording medium 5. The mode selection unit 102 is configured to select the first printing mode when the type of recording medium 5 input to the media input unit 101 is not a predetermined type of recording medium 5, for example, an opaque recording medium or a recording medium of unknown type where transparency was not specified. The mode selection unit 102 may also be configured to allow direct selection of the printing mode. The first printing mode and the second printing mode may each be subdivided internally into, for example, a high-quality mode and a high-speed mode.

[0039] The first print control unit 103 performs printing in the first print mode. Specifically, in the first print mode, the first print control unit 103 is configured to move the carriage 40 in the first main scanning direction Y1 and the second main scanning direction Y2, and ejects ink to the recording head 60 when moving the carriage 40 in the first main scanning direction Y1 and when moving it in the second main scanning direction Y2. Along with ejecting the ink, the first print control unit 103 lights up the first light irradiator 70L and the second light irradiator 70R. In other words, in the first print mode, printing is performed whenever the carriage 40 moves in either direction of the main scanning direction Y. That is, if the recording medium 5 is deemed opaque, bidirectional printing is performed. As will be explained later, if the recording medium 5 is deemed transparent, unidirectional printing is performed, but this does not mean that unidirectional printing is not permitted even if the recording medium 5 is opaque.

[0040] The second print control unit 104 performs printing in the second print mode. Specifically, in the second print mode, the second print control unit 104 moves the carriage 40 in the first main scanning direction Y1 and the second main scanning direction Y2, and is configured to turn off the second light irradiator 70R when moving the carriage 40 in the first main scanning direction Y1 and the second main scanning direction Y2. That is, if the recording medium 5 is recognized as a transparent recording medium, the second light irradiator 70R is turned off. When the second print control unit 104 moves the carriage 40 in the second main scanning direction Y2, it ejects ink from the recording head 60 and turns on the first light irradiator 70L. That is, printing is performed when the carriage 40 is moved in the second main scanning direction Y2. When the second print control unit 104 moves the carriage 40 in the first main scanning direction Y1, it stops ejecting ink from the recording head 60. In other words, no printing occurs when the carriage 40 is moved in the second main scanning direction Y2. Printing in the second printing mode is unidirectional printing. When the carriage 40 is moved in the first main scanning direction Y1 in the second printing mode, the first light irradiator 70L may be turned on or off. Here, the second printing control unit 104 is configured to turn on the first light irradiator 70L even when the carriage 40 is moved in the first main scanning direction Y1 in the second printing mode. During the second printing mode, the first light irradiator 70L is not controlled to turn on or off and remains lit.

[0041] The following describes the printing process by the printer 10 according to this embodiment.

[0042] [Select Print Mode] Before printing begins, the print mode is selected. If the type of recording medium 5 is registered in the printer 10, the type of recording medium 5 is selected. If the type of recording medium 5 allows the printer 10 to determine whether the recording medium 5 is transparent or opaque, the printer 10 automatically sets whether the recording medium 5 is transparent or opaque. However, the user may input whether the recording medium 5 is transparent or opaque. Alternatively, the user may select the print mode regardless of the characteristics of the recording medium 5. When setting the print mode, print settings other than the first print mode (print mode for opaque recording medium 5) / second print mode (print mode for transparent recording medium 5) may be set as needed.

[0043] [First Print Mode] First, we will explain the case where the first printing mode is selected as the printing mode. Figure 6 is a schematic front view of the carriage 40 showing the light reflection state during printing in the first printing mode. In Figures 6 to 8, the light emitted from the first light irradiator 70L is represented by the symbol UV1, and the light emitted from the second light irradiator 70R is represented by the symbol UV2. As shown in Figure 6, in the first printing mode, printing occurs when the carriage 40 moves in the first main scanning direction Y1 and when it moves in the second main scanning direction Y2 (indicated by the double arrow A between the first main scanning direction Y1 and the second main scanning direction Y2). Since bidirectional printing is performed in the first printing mode, the first light irradiator 70L and the second light irradiator 70R are lit during printing.

[0044] Figure 6 illustrates the case where the recording medium 5 is an opaque recording medium. When printing on an opaque recording medium 5, the light irradiated from the first light irradiator 70L and the second light irradiator 70R that reaches the recording medium 5 is reflected but does not penetrate into the recording medium 5. The light reflected by the recording medium 5 is reflected several times between the lower surface of the carriage 40 and the recording medium 5 before reaching the recording head 60. At this time, the reflected light that reaches the recording head 60 is attenuated by scattering due to reflection and by traveling through the air. The distance L2 in the main scanning direction Y between the recording head 60 and the second light irradiator 70R is set to a distance such that the reflected light that reaches the recording head 60 does not cause problems for the recording head 60 (e.g., thickening or hardening of the ink) when the recording medium 5 is opaque. When the recording medium 5 is opaque, the reflected light that reaches the recording head 60 is attenuated to a degree that does not cause problems for the recording head 60. The distance L1 between the first light irradiator 70L and the recording head 60 is longer than that between the first light irradiator 70L and the recording head 60. Therefore, the reflected light from the first light irradiation device 70L is further attenuated.

[0045] Figure 7 is a schematic front view of the carriage 40 illustrating the light reflection state when printing on a transparent recording medium 5 in the first printing mode. As shown in Figure 7, when printing on a transparent recording medium 5, the light irradiated from the first light irradiator 70L and the second light irradiator 70R that reaches the recording medium 5 is reflected and also transmitted into the recording medium 5. A portion of the light irradiated from the second light irradiator 70R and transmitted into the recording medium 5 is reflected at the boundary between the recording medium 5 and the flatbed 20, and then transmitted from the top surface of the recording medium 5 to the outside of the recording medium 5. Another portion of the light transmitted into the recording medium 5 is reflected at the boundary between the recording medium 5 and the flatbed 20, and then reflected at the top surface of the recording medium 5 and travels through the inside of the recording medium 5. Light that travels through the inside of the transparent recording medium 5 while being reflected is absorbed by the reflective surface and is therefore less attenuated. Therefore, when printing on a transparent recording medium 5, there is a risk that light irradiated from the second light irradiator 70R, which travels through the inside of the transparent recording medium 5 and is therefore not attenuated much, may reach the recording head 60. This could potentially cause problems with the recording head 60 due to the light.

[0046] [Second Print Mode] Next, we will describe the case when the second printing mode is selected as the printing mode. Figure 8 is a front view of the carriage 40 schematically showing the light reflection state during printing in the second printing mode. The recording medium 5 is a transparent recording medium. As shown in Figure 8, in the second printing mode, printing is performed when the carriage 40 moves in the second main scanning direction Y2, and no printing is performed when the carriage 40 moves in the first main scanning direction Y1 (indicated by a single arrow B pointing towards the second main scanning direction Y2). Since printing in the second printing mode is unidirectional printing in the second main scanning direction Y2, only the first light illuminator 70L, which is located behind the recording head 60 in the direction of travel, is lit.

[0047] As shown in Figure 8, when printing on a transparent recording medium 5, the light emitted from the first light irradiator 70L and reaching the recording medium 5 is reflected and also passes through the recording medium 5. Therefore, when printing on a transparent recording medium 5, some of the light travels through the inside of the transparent recording medium 5. As mentioned above, light that travels through the inside of the transparent recording medium 5 while being reflected is less attenuated than light that travels through the outside of the recording medium 5 while being reflected. However, in the printer 10 according to this embodiment, the distance L1 between the first light irradiator 70L and the recording head 60 in the main scanning direction Y is set to be long. As a result, the distance that the light travels to reach the recording head 60 is longer, and the attenuation of reflected light is greater. Therefore, the amount of light that reaches the recording head 60 can be reduced.

[0048] In the second printing mode, the second light irradiator 70R is turned off. The distance L2 between the second light irradiator 70R and the recording head 60 in the main scanning direction Y is shorter than the distance L1 between the first light irradiator 70L and the recording head 60 in the main scanning direction Y. Therefore, if the second light irradiator 70R is turned on, as in the case of Figure 7, there is a risk that light that has traveled through the transparent recording medium 5 and not been attenuated much may reach the recording head 60. If this happens, there is a risk that the recording head 60 may be damaged by the light that reaches it. In this embodiment, this is prevented by turning off the second light irradiator 70R in the second printing mode. As a result, the risk of the recording head 60 being damaged by light that reaches it can be reduced.

[0049] The distance L1 in the main scanning direction Y between the recording head 60 and the first light irradiator 70L is set to a distance such that the reflected light reaching the recording head 60 does not cause problems to the recording head 60, even if the recording medium 5 is transparent. Figure 9 is a graph showing an example of the results of measuring the amount of reflected light reaching the recording head 60. The horizontal axis of Figure 9 is the distance in the main scanning direction Y between the ink head and the light irradiator. The vertical axis of Figure 9 is the amount of reflected light. In the graph of Figure 9, point P1 on the horizontal axis "L1" is the point where the measured value of reflected light at the first ink head 61 is plotted. Point P1 shows the amount of light measured at the first ink head 61 when the recording medium 5 is a transparent recording medium and only the first light irradiator 70L is lit. In the graph of Figure 9, point P2 on the horizontal axis "L2" is the point where the measured value of reflected light at the second ink head 62 is plotted. Point P2 represents the light intensity measured at the second ink head 62 when the recording medium 5 is a transparent recording medium and only the second light irradiation device 70R is lit. The graph in Figure 9 is a hypothetical curve connecting points P1 and P2 (a quadratic curve is assumed because the light intensity is inversely proportional to the square of the distance).

[0050] As shown in Figure 9, distance L1 is approximately twice the distance L2. The amount of light at the first ink head 61, indicated by point P1, is approximately one-thirteenth of the amount of light at the second ink head 62, indicated by point P2. From this, it can be seen that by increasing the distance L1 between the recording head 60 and the first light irradiator 70L, the amount of light reaching the recording head 60 can be significantly reduced.

[0051] On the other hand, if not only the distance L1 between the recording head 60 and the first light irradiator 70L, but also the distance L2 between the recording head 60 and the second light irradiator 70R is increased, the distance between the left end of the first light irradiator 70L and the right end of the second light irradiator 70R (hereinafter also referred to as the width of the carriage 40) will increase. An increase in the width of the carriage 40 will cause the printer 10 to become larger. Therefore, in this embodiment, the distance L1 between the recording head 60 and the first light irradiator 70L is made longer than the distance L2 between the recording head 60 and the second light irradiator 70R. This makes it possible to achieve a good balance between suppressing reflected light irradiated onto the recording head 60 and suppressing the length of the main scanning direction Y of the printer 10.

[0052] [Effects of the Embodiment] The following describes the effects and benefits that the printer 10 according to this embodiment can provide.

[0053] The printer 10 according to this embodiment includes a first light irradiation device 70L fixed to the carriage 40 so as to be located in the first main scanning direction Y1 relative to the recording head 60, and which irradiates light to cure the ink toward the flatbed 20, and a second light irradiation device 70R fixed to the carriage 40 so as to be located in the second main scanning direction Y2 relative to the recording head 60, and which irradiates light to cure the ink toward the flatbed 20. In the printer 10 according to this embodiment, with respect to the main scanning direction Y, the distance L1 between the first light irradiation device 70L and the recording head 60 is longer than the distance L2 between the second light irradiation device 70R and the recording head 60.

[0054] With this printer 10, the amount of reflected light that reaches the recording head 60 after being irradiated from the first light irradiator 70L and reflected by the recording medium 5 can be made less than the amount of reflected light that reaches the recording head 60 after being irradiated from the second light irradiator 70R and reflected by the recording medium 5. As a result, the amount of reflected light irradiated onto the recording head 60 can be reduced. Furthermore, with this printer 10, with respect to the main scanning direction Y, the distance L2 between the second light irradiator 70R and the recording head 60 can be made shorter than the distance L1 between the first light irradiator 70L and the recording head 60. This makes it possible to shorten the length of the printer 10 in the main scanning direction Y. Therefore, with this embodiment of the printer 10, it is possible to achieve a good balance between suppressing reflected light irradiated onto the recording head 60 and suppressing the length of the printer 10 in the main scanning direction Y.

[0055] In this embodiment, the control device 100 controls the carriage moving device 50, the recording head 60, the first light irradiation device 70L, and the second light irradiation device 70R. The control device 100 includes a mode selection unit 102 configured to select a printing mode from a plurality of printing modes, including a first printing mode and a second printing mode; a first printing control unit 103 that performs printing in the first printing mode; and a second printing control unit 104 that performs printing in the second printing mode. In the first printing mode, the first printing control unit 103 is configured to move the carriage 40 in the first main scanning direction Y1 and the second main scanning direction Y2, and ejects ink from the recording head 60 when moving the carriage 40 in the first main scanning direction Y1 and the second main scanning direction Y2. In addition, in the first printing mode, the first printing control unit 103 lights up the first light irradiation device 70L and the second light irradiation device 70R.

[0056] In the second printing mode, the second printing control unit 104 moves the carriage 40 in the first main scanning direction Y1 and the second main scanning direction Y2, and is configured to turn off the second light illuminator 70R when moving the carriage 40 in the first main scanning direction Y1 and the second main scanning direction Y2. In the second printing mode, when the carriage 40 is moved in the second main scanning direction Y2, the second printing control unit 104 ejects ink from the recording head 60 and turns on the first light illuminator 70L. Also, in the second printing mode, when the carriage 40 is moved in the first main scanning direction Y1, the second printing control unit 104 stops ejecting ink from the recording head 60. With such a printer 10, when the recording medium 5 does not reflect much light, for example, an opaque recording medium 5, the first printing mode can be selected and the printing speed can be increased by bidirectional printing. Furthermore, in the case of a recording medium 5 that produces a lot of reflected light, such as a transparent recording medium 5, the second printing mode can be selected, and the reflected light to the recording head 60 can be suppressed, even at the expense of printing speed by using unidirectional printing.

[0057] In this embodiment, the second print control unit 104 is configured to light up the first light irradiator 70L even when moving the carriage 40 in the first main scanning direction Y1 in the second print mode. That is, the second print control unit 104 lights up the first light irradiator 70L even when moving in the first main scanning direction Y1, where it is not necessary to light up the first light irradiator 70L. This prevents the amount of light emitted by the first light irradiator 70L from becoming unstable by turning it off. When the first light irradiator 70L is turned on again after being turned off, it takes time for the amount of light emitted to reach the set amount. Therefore, if the first light irradiator 70L is turned off during printing, the amount of light emitted by the first light irradiator 70L becomes unstable. In this embodiment, the amount of light reaching the recording head 60 is suppressed by increasing the distance L1 between the first light irradiator 70L and the recording head 60. Therefore, in the second printing mode, even when the first light illuminator 70L is lit while moving the carriage 40 in the first main scanning direction Y1, the effect of reflected light on the recording head 60 is small.

[0058] In this embodiment, the control device 100 includes a media input unit 101 into which the type of recording medium 5 is input. The mode selection unit 102 is configured to select a second print mode when the type of recording medium 5 input to the media input unit 101 is a predetermined type. With this configuration, the printer 10 determines whether to use the first print mode or the second print mode based on the type of recording medium 5, even if the user does not select a print mode. Therefore, it is possible to suppress user errors in judgment and errors such as forgetting to select the second print mode.

[0059] The specified type of recording medium 5 described above is, in this case, a transparent recording medium. As described above, since a transparent recording medium 5 produces a lot of reflected light, there is a greater effect in increasing the distance L1 between the first light irradiator 70L and the recording head 60.

[0060] In this embodiment, the printer 10 includes a carriage base 45 as a holding member fixed to the carriage 40 and holding the first light irradiator 70L and the second light irradiator 70R. The carriage base 45 includes a first holding portion 45L that extends beyond the carriage in the first main scanning direction Y1 and holds the first light irradiator 70L beyond the carriage 40 in the first main scanning direction Y1, and a second holding portion 45R that extends beyond the carriage 40 in the second main scanning direction Y2 and holds the second light irradiator 70R beyond the carriage 40 in the second main scanning direction Y2. In this embodiment, the recording head 60 is positioned in the center of the carriage 40 with respect to the main scanning direction Y. With respect to the main scanning direction Y, the length L3 of the portion of the first holding portion 45L between the carriage 40 and the first light irradiator 70L is longer than the length L4 of the portion of the second holding portion 45R between the carriage 40 and the second light irradiator 70R. In other words, the distance L1 between the first light irradiator 70L and the recording head 60, and the distance L2 between the second light irradiator 70R and the recording head 60, are adjusted by the lengths of the first holding section 45L and the second holding section 45R, respectively, and not by the position of the recording head 60 in the carriage 40.

[0061] With this configuration, for example, when deploying this technology to models with a changed light intensity of the light irradiation device 70, or models with a changed vertical distance Z between the recording medium 5 and the light irradiation device 70, there is no need to change the configuration of the carriage 40. Therefore, deployment is easy.

[0062] Several preferred embodiments have been described above. However, the inkjet printer of the present invention is not limited to the embodiments described above. For example, in the embodiments described above, the printer 10 was a flatbed type printer, but the configuration of the printer is not particularly limited. For example, the technology disclosed herein may be applied to a printer in which the recording medium is supplied from a roll. The support base for the recording medium may be a platen on which the recording medium supplied from the roll is placed.

[0063] In the above embodiment, the light irradiation device with a long distance from the recording head was the left light irradiation device, but it may also be the right light irradiation device.

[0064] In the embodiment described above, the distance L1 between the first light irradiator 70L and the recording head 60, and the distance L2 between the second light irradiator 70R and the recording head 60 were adjusted by the lengths of the first holding section 45L and the second holding section 45R, respectively, but they may also be adjusted by the position of the recording head 60 on the carriage 40. In this case, the first light irradiator 70L and the second light irradiator 70R are arranged symmetrically with respect to the center line CL1 of the carriage 40, and the position of the recording head 60 on the carriage 40 may be shifted to one side of the main scanning direction Y.

[0065] Unless otherwise specified, the embodiments described above do not limit the present invention. [Explanation of symbols]

[0066] 5. Recording media 10 Inkjet Printers 20 Flatbed (support stand) 40 Carriage 45. Carriage base (retaining member) 45L 1st holding part 45R 2nd holding part 50 Carriage moving device 60 recording heads 70L 1st light irradiation device 70R 2nd light irradiation device 100 Control device 101 Media Input Section (Input Section) 102 Mode Selection Section 103 First Printing Control Unit 104 Second Printing Control Unit Y Main scanning direction (scanning direction) Y1 First main scanning direction (first scanning direction) Y2 Second main scanning direction (second scanning direction)

Claims

1. A support base extending in a predetermined scanning direction and supporting the recording medium, A carriage provided opposite the aforementioned support base, A carriage moving device that moves the carriage in a first scanning direction, which is one of the aforementioned scanning directions, and a second scanning direction, which is the other direction. A recording head provided on the carriage for ejecting photocurable ink toward the support base, A first light irradiation device is fixed to the carriage so as to be positioned in the first scanning direction relative to the recording head, and irradiates light for curing the ink toward the support base, A second light irradiation device is fixed to the carriage so as to be positioned in the second scanning direction relative to the recording head, and irradiates light that cures the ink toward the support base, The system comprises a carriage movement device, a recording head, a first light irradiation device, and a control device for controlling the second light irradiation device, With respect to the scanning direction, the distance between the first light irradiation device and the recording head is longer than the distance between the second light irradiation device and the recording head. The control device is A mode selection unit configured to allow selection of a print mode from multiple print modes, including a first print mode and a second print mode, A first print control unit that performs printing in the first print mode, The system includes a second print control unit that performs printing in the second print mode, In the first printing mode, the first printing control unit is configured to move the carriage in a first scanning direction and a second scanning direction, and when moving the carriage in the first scanning direction and when moving it in the second scanning direction, it ejects the ink to the recording head and lights up the first light irradiator and the second light irradiator. In the second printing mode, the second printing control unit is configured to move the carriage in the first scanning direction and the second scanning direction, and to turn off the second light irradiation device when moving the carriage in the first scanning direction and the second scanning direction, to eject the ink from the recording head and turn on the first light irradiation device when moving the carriage in the second scanning direction, and to stop the ejection of the ink from the recording head when moving the carriage in the first scanning direction. Inkjet printer.

2. The second printing control unit is configured to also light the first light irradiation device when moving the carriage in the first scanning direction in the second printing mode. The inkjet printer according to claim 1.

3. The control device includes an input unit into which the type of recording medium is input, The mode selection unit is configured to select the second printing mode when the type of recording medium input to the input unit is of a predetermined type. The inkjet printer according to claim 1.

4. The aforementioned predetermined type of recording medium is a transparent recording medium. The inkjet printer according to claim 3.

5. The carriage is fixed to the holding member which holds the first light irradiation device and the second light irradiation device, The aforementioned retaining member is A first holding portion that extends beyond the carriage in the first scanning direction and holds the first light irradiation device in the first scanning direction beyond the carriage, It includes a second holding portion that extends beyond the carriage in the second scanning direction and holds the second light irradiation device in the second scanning direction beyond the carriage, The recording head is positioned in the center of the carriage with respect to the scanning direction. With respect to the scanning direction, the length of the portion of the first holding part between the carriage and the first light irradiation device is longer than the length of the portion of the second holding part between the carriage and the second light irradiation device. An inkjet printer according to any one of claims 1 to 4.

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