JP2010269471A - Liquid jetting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jetting apparatus which reduces leakage of light. <P>SOLUTION: The liquid jetting apparatus includes a head which jets towards a medium a liquid cured when irradiated with light, and an irradiating part which irradiates the light. The irradiating part has a light source of the light and a plurality of prisms arranged between the light source and the medium. The prism has a first surface perpendicular to the medium, and a second surface having an interval to the first surface narrowed away from the light source. The plurality of prisms are arranged so that the second surface of each prism is inside the irradiating part with respect to the first surface. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid ejecting apparatus.

  There is known a liquid ejecting apparatus that performs printing using a liquid (for example, UV ink) that is cured by irradiation with light (a kind of electromagnetic wave, for example, ultraviolet (UV)). Such a liquid ejecting apparatus includes a head that ejects liquid and a light irradiation unit. After the liquid is ejected from the head onto the medium, the dots formed on the medium are irradiated with light. By doing so, the dots are cured and fixed to the medium, so that it is possible to perform good printing even on a medium that hardly absorbs liquid (for example, see Patent Document 1).

JP 2004-188923 A

By the way, in such a liquid ejecting apparatus, there is a possibility that light emitted from the light source of the irradiation unit leaks to the head. In this case, the liquid in the nozzle of the head may be hardened and clogging may occur.
Accordingly, an object of the present invention is to reduce light leakage.

  A main invention for achieving the above object is a liquid ejecting apparatus including a head that ejects a liquid that is cured by being irradiated with light toward a medium, and an irradiation unit that emits the light. The irradiation unit includes a light source of the light, a plurality of prisms disposed between the light source and the medium, a first surface perpendicular to the medium, and the first surface as the distance from the light source increases. And a plurality of prisms arranged such that the second surface of each prism is located inside the irradiating unit with respect to the first surface. A liquid ejecting apparatus characterized by the above.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

1 is a block diagram of an overall configuration of a printer. FIG. 3 is a schematic view around a print area. It is explanatory drawing of the nozzle arrangement | positioning of each head. It is a schematic explanatory drawing of the irradiation part of a reference example. It is a figure which shows the relationship between reflection and refraction when light is incident on the boundary between media having different refractive indexes. 6A and 6B are explanatory diagrams of the shape of the prism used in this embodiment. It is explanatory drawing of arrangement | positioning of the prism in the irradiation part of this embodiment. FIG. 8A and FIG. 8B are explanatory diagrams of a prism as an improved example of the first embodiment. It is explanatory drawing of the structure of the irradiation part and UV irradiation in the modified example of 1st Embodiment. It is explanatory drawing of the structure of the irradiation part of 2nd Embodiment, and UV irradiation. It is explanatory drawing of 3rd Embodiment.

  At least the following matters will become clear from the description of the present specification and the accompanying drawings.

A liquid ejecting apparatus comprising: a head that ejects a liquid that is cured by receiving light irradiation toward a medium; and an irradiation unit that irradiates the light, wherein the irradiation unit includes: a light source of the light; A plurality of prisms arranged between the light source and the medium, a first surface perpendicular to the medium, and a second surface in which a distance between the first surface and the first surface decreases as the distance from the light source increases. And a plurality of prisms arranged so that the second surface of each prism is located inside the irradiating unit with respect to the first surface. .
According to such a liquid ejecting apparatus, leakage of light from the irradiation unit can be reduced.

In this liquid ejecting apparatus, it is preferable that the maximum value of the distance between the first surface and the second surface of each prism is shorter than the length of the first surface in the direction perpendicular to the medium.
According to such a liquid ejecting apparatus, the spread of light irradiated on the medium can be reduced.

In the liquid ejecting apparatus, it is preferable that the first surface is a reflecting surface that reflects all the incident light.
According to such a liquid ejecting apparatus, since no light is emitted outside the first surface, the light can be collected inside the irradiation unit.

In the liquid ejecting apparatus, it is preferable that a rectangular prism having an end surface perpendicular to the medium is further provided between the light source and each prism.
According to such a liquid ejecting apparatus, light can be converged more.

  In addition, when the liquid ejecting apparatus includes a cylindrical transport member that transports the medium on the circumferential surface, and the head and the irradiation unit are disposed along the circumferential surface of the transport member, In particular, light leakage can be reduced.

  In the following embodiments, a printer (printer 1) will be described as an example of the liquid ejecting apparatus.

=== First Embodiment ===
<About printer configuration>
FIG. 1 is a block diagram of the overall configuration of the printer 1. FIG. 2 is a schematic view around the print area.

  The printer 1 is a printing device that prints an image on a medium such as paper, cloth, or film, and is communicably connected to a computer 110 that is an external device.

A printer driver is installed in the computer 110. The printer driver is a program for displaying a user interface on a display device (not shown) and converting image data output from an application program into print data. This printer driver is recorded on a recording medium (computer-readable recording medium) such as a flexible disk FD or a CD-ROM. The printer driver can also be downloaded to the computer 110 via the Internet. In addition, this program is comprised from the code | cord | chord for implement | achieving various functions.
Then, the computer 110 outputs print data corresponding to the image to be printed to the printer 1 in order to cause the printer 1 to print an image.

  The printer 1 according to the present embodiment is an apparatus that prints an image on a medium by ejecting ultraviolet curable ink (hereinafter, UV ink) that is cured by irradiation with ultraviolet rays (hereinafter, UV) as an example of a liquid. The UV ink is an ink containing an ultraviolet curable resin, and is cured by undergoing a photopolymerization reaction in the ultraviolet curable resin when irradiated with UV. Note that the printer 1 of the present embodiment prints an image using four colors of UV ink, cyan, magenta, yellow, and black.

  The printer 1 according to this embodiment includes a transport unit 20, a head unit 30, an irradiation unit 40, a detector group 50, and a controller 60. The printer 1 that has received print data from the computer 110 that is an external device controls each unit (the transport unit 20, the head unit 30, and the irradiation unit 40) by the controller 60, and prints an image on a medium according to the print data. The controller 60 controls each unit based on the print data received from the computer 110 and prints an image on a medium. The situation in the printer 1 is monitored by the detector group 50, and the detector group 50 outputs the detection result to the controller 60. The controller 60 controls each unit based on the detection result output from the detector group 50.

  The transport unit 20 is for transporting a medium (for example, paper) in a predetermined direction (hereinafter referred to as a transport direction). The transport unit 20 includes an upstream transport roller 23 </ b> A, a downstream transport roller 23 </ b> B, and a belt 24. When a transport motor (not shown) rotates, the upstream transport roller 23A and the downstream transport roller 23B rotate, and the belt 24 rotates. The medium fed by a paper feed roller (not shown) is conveyed by the belt 24 to a printable area (area facing the head). As the belt 24 transports the medium, the medium moves in the transport direction with respect to the head unit 30. The medium that has passed through the printable area is discharged to the outside by the belt 24. Note that the medium being transported is electrostatically attracted or vacuum attracted to the belt 24.

  The head unit 30 is for ejecting UV ink onto a medium. In the present embodiment, four colors of UV inks of cyan, magenta, yellow, and black are used as the UV ink to form an image. The head unit 30 ejects each ink onto the medium being conveyed, thereby forming dots on the medium and printing an image on the medium. In this embodiment, as shown in FIG. 2, in order from the upstream side in the transport direction, a black ink head K that ejects black UV ink, a cyan ink head C that ejects cyan UV ink, and magenta UV ink are ejected. There are provided a magenta ink head M that performs yellow ink and a yellow ink head Y that ejects yellow UV ink. The printer 1 of the present embodiment is a line printer, and each head of the head unit 30 can form dots for the medium width at a time.

  The irradiation unit 40 irradiates UV toward the UV ink that has landed on the medium. The dots formed on the medium are cured by receiving UV irradiation from the irradiation unit 40. The irradiation unit 40 according to the present embodiment includes a provisional curing irradiation unit 42 and a main curing irradiation unit 44, and performs two-stage curing (UV irradiation) on the dots formed on the medium. )It is carried out.

  The pre-curing irradiation unit 42 irradiates UV for pre-curing dots formed on the medium. In the present embodiment, the term “temporary curing” refers to provisional curing in order to suppress the flow (spreading of dots) of UV ink that has landed on a medium, or to prevent bleeding of ink between dots. The surface portion is cured. The printer 1 according to the present embodiment includes a first irradiation unit 42a, a second irradiation unit 42b, a third irradiation unit 42c, and a fourth irradiation unit 42d as irradiation units of the pre-curing irradiation unit 42.

  The first irradiation unit 42 a is provided on the downstream side in the transport direction of the black ink head K, and the second irradiation unit 42 b is provided on the downstream side in the transport direction of the cyan ink head C. The third irradiation unit 42c is provided on the downstream side in the conveyance direction of the magenta ink head M, and the fourth irradiation unit 42d is provided on the downstream side in the conveyance direction of the yellow ink head Y. The length of each of these irradiation parts in the medium width direction is equal to or greater than the medium width. Each irradiation unit irradiates the dots formed by each head of the head unit 30 with UV.

  Each irradiation unit of the pre-curing irradiation unit 42 of the present embodiment includes a light emitting diode (LED) as a light source for UV irradiation. The LED can easily change the irradiation energy by controlling the magnitude of the input current. Moreover, each irradiation part of this embodiment has a some prism, respectively. Details of the irradiation unit will be described later.

The main curing irradiation unit 44 irradiates UV for main curing the dots formed on the medium. In the present embodiment, the main curing is curing performed to completely solidify the dots. That is, the irradiation amount of the main curing is larger than the irradiation amount of the temporary curing.
The main curing irradiation unit 44 is provided downstream of the fourth irradiation unit 42d of the temporary curing irradiation unit 42 in the transport direction. That is, the head unit 30 is provided at a location away from each head. Further, the length of the main curing irradiation unit 44 in the medium width direction is equal to or greater than the medium width. Then, the main curing irradiation unit 44 irradiates the dots formed by the heads of the head unit 30 with UV for main curing.
The main curing irradiation unit 44 of the present embodiment includes a lamp (a metal halide lamp, a mercury lamp, or the like) as a UV irradiation light source.

  The detector group 50 includes a rotary encoder (not shown), a paper detection sensor (not shown), and the like. The rotary encoder detects the rotation amount of the upstream side conveyance roller 23A and the downstream side conveyance roller 23B. The transport amount of the medium can be detected based on the detection result of the rotary encoder. The paper detection sensor detects the position of the leading edge of the medium being fed.

  The controller 60 is a control unit (control unit) for controlling the printer. The controller 60 includes an interface unit 61, a CPU 62, a memory 63, and a unit control circuit 64. The interface unit 61 transmits and receives data between the computer 110 that is an external device and the printer 1. The CPU 62 is an arithmetic processing unit for controlling the entire printer. The memory 63 is for securing an area for storing a program of the CPU 62, a work area, and the like, and includes storage elements such as a RAM and an EEPROM. The CPU 62 controls each unit via the unit control circuit 64 in accordance with a program stored in the memory 63.

<About printing operation>
When the printer 1 receives print data from the computer 110, the controller 60 first rotates a paper feed roller (not shown) by the transport unit 20 and sends a medium to be printed onto the belt 24. The medium is conveyed on the belt 24 without stopping at a constant speed, and passes under the head unit 30 and the irradiation unit 40. During this time, the controller 60 intermittently ejects ink from the nozzles of the heads of the head unit 30 to form dots on the medium and irradiates UV from the irradiation units of the irradiation unit 40. Thus, an image is printed on the medium. Then, the controller 60 discharges the medium on which image printing has been completed.

<About the nozzle arrangement of each head>
FIG. 3 is an explanatory diagram of an example of the nozzle arrangement of each head. As shown in the figure, each head includes two nozzle rows of “A row” and “B row” on the lower surface of each head.
The nozzles in each row are arranged at an interval (nozzle pitch) of 1/180 inch along a direction (nozzle row direction) intersecting the transport direction. Further, the position in the nozzle row direction of the nozzles in the A row and the position in the nozzle row direction of the nozzles in the B row are shifted by a half nozzle pitch (1/360 inch). This makes it possible to form dots of each color with a resolution of 1/360 inch.

=== About Irradiation Unit ===
<Reference example>
FIG. 4 is a schematic explanatory diagram of an irradiation unit of a reference example.
In the drawing, the head K and the head C, and each irradiation unit (first irradiation unit 42a and second irradiation unit 42b) for temporary curing on the downstream side in the transport direction of each head are shown. Since the first irradiation unit 42a and the second irradiation unit 42b have the same configuration, only the first irradiation unit 42a will be described below. Although not shown, nozzles for ejecting UV ink are provided on the lower surface of each head as described above. The first irradiation section 42a in FIG. 4 includes a hood 420 and a light source 421. is doing.
The hood 420 covers the light source 421 and is open on the medium side (lower side in the figure).
The light source 421 is, for example, an LED, and a plurality of the light sources 421 are provided in the irradiation unit. The light source 421 emits UV light.

  In the case of this reference example, there is an optical path in which the UV light from the light source 421 is reflected by the hood 420. And UV light may leak out of the 1st irradiation part 42a like a figure. In the case of this figure, the head K and the head C adjacent to the first irradiation unit 42a are irradiated with the UV light of the first irradiation unit 42a. As a result, the ink in the nozzles of the head K and the head C may be cured and clogging may occur. Similarly, other heads may be clogged by UV light leaking from each irradiation unit. Further, for example, a UV light absorbing material may be attached to the inside of the hood 420 so as to eliminate the optical path as shown in the figure, but in this case, the irradiation amount of the UV light to the medium is reduced.

  Since the main curing irradiation unit 44 is located away from each head, only the irradiation units of the temporary curing irradiation unit 42 are examined in the following embodiments.

<About the irradiation unit of the first embodiment>
In the reference example described above, UV light may leak out of the irradiation unit. Therefore, in this embodiment, the leakage of UV light is reduced.
In this embodiment, a prism is used to reduce leakage of UV light. Hereinafter, the prism used in the present embodiment will be briefly described.

A prism is a polyhedron made of glass or quartz having a refractive index different from that of the surrounding space (air), and diffuses, refracts, and reflects light.
FIG. 5 is a diagram showing the relationship between reflection and refraction when light is incident on the boundary between media having different refractive indexes. The refractive index of the medium 1 is n1, and the refractive index of the medium 2 is n2 (> n1).
As shown in the figure, when the incident angle is small (right side in the figure), reflection and refraction occur with respect to the incidence of light on the boundary of the medium. On the other hand, when the incident angle exceeds the critical angle, total reflection (no refraction) occurs.
The incident angle and the reflection angle are equal. If the incident angle is θ1 and the refraction angle is θ2,
n1sin θ1 = n2sin θ2
(Snell's law) holds.

  6A and 6B are explanatory diagrams of the shape of the prism used in this embodiment. In this embodiment, a prism 423 having a triangular cross section is used. As shown in the figure, the prism 423 is disposed between the light source 421 and the medium. Also, the prism 423 corresponds to the upper surface Sa, the vertical surface Sb perpendicular to the medium (corresponding to the first surface), and the slope Sc (corresponding to the second surface) whose distance from the vertical surface Sb decreases as the distance from the light source 421 increases. ). 6A and 6B differ in the length d of the upper surface Sa of the prism 423 (that is, the maximum value of the interval between the vertical surface Sb and the inclined surface Sc). In FIGS. 6A and 6B, the solid line indicates the optical path including only refraction, and the dotted line indicates the optical path including total reflection.

  By disposing such a prism 423 between the light source 421 and the medium, the UV light emitted from the light source 421 is reflected and refracted as shown in the drawing on the vertical surface Sb and the inclined surface Sc. Then, due to the reflection and refraction of the prism 423, the irradiation region of the UV light on the medium is narrowed. Specifically, on the medium, more UV is irradiated toward the inclined surface Sc than the vertical surface Sb.

  6A and 6B, UV light refracted by the vertical surface Sb and the inclined surface Sc is emitted from the prism 423, but FIG. 6A emits less UV light than FIG. 6B. . This is because, in FIG. 6A, the length d of the upper surface Sa with respect to the vertical surface Sb is short, so that a region having a large incident angle with respect to the vertical surface Sb and the inclined surface Sc increases, and the total reflected UV light increases. (See dotted optical path). Therefore, UV light can be collected more in FIG. 6A than in FIG. 6B.

  FIG. 7 is an explanatory diagram of the arrangement of the prisms in the irradiation unit of the present embodiment. In the figure, the first irradiation unit 42a is shown, but the other irradiation units have the same configuration.

As illustrated in FIG. 7, the first irradiation unit 42 a of the present embodiment includes a hood 420, a light source 421, and a plurality of prisms 423.
The prism 423 is provided between the light source 421 and the medium. The prism 423 is arranged so that the slope Sc is inside the hood 420 with respect to the vertical surface Sb. Note that the length of the vertical surface Sb is sufficiently longer than the length of the upper surface Sa.
By arranging the prism 423 in this way, the UV light emitted from the light source 421 is collected inside the hood 420 by reflection and refraction at the vertical surface Sb and the inclined surface Sc of the prism 423. Thereby, the spread of the UV light reaching the medium is smaller than in the case of the reference example.
Therefore, the leakage of UV light from the first irradiation unit 42a can be reduced, and the adjacent head K and head C can be prevented from being irradiated with UV light. In the present embodiment, since UV light is not absorbed by a light absorbing material or the like, the irradiation intensity can be prevented from being impaired.

<Improvement example of the first embodiment>
FIG. 8A and FIG. 8B are explanatory diagrams of a prism as an improved example of the first embodiment. Note that the length (d) of the upper surface Sa of the prism 423 differs between FIG. 8A and FIG. 8B.
In this improved example, the vertical surface Sb of the prism 423 is mirror-coated (Sb ′). Thereby, the vertical surface Sb ′ is a reflecting surface, and all incident light on the vertical surface Sb ′ is reflected. Therefore, the UV light is not emitted from the vertical surface Sb ′.
In this improved example, since the UV light emitted from the vertical surface Sb ′ is eliminated, the light condensing rate to the medium can be further increased as compared with the case of FIGS. 6A and 6B. As can be seen from FIG. 8, the spread of UV light reaching the medium is smaller in FIG. 8A than in FIG. 8B (L1 <L2). That is, FIG. 8A is more advantageous than FIG. 8B to suppress the spread of the optical path.

FIG. 9 is an explanatory diagram of the configuration of the irradiation unit and UV irradiation in an improved example of the first embodiment. Although the figure shows the first irradiation unit 42a, the same applies to the other irradiation units. In the figure, two light sources 421 are used for simplification of description.
In FIG. 9, a plurality of prisms 423 in FIG. 8A are arranged as in the case of FIG.
The UV light emitted from the light source 421 is reflected on the vertical surface (mirror surface) Sb ′ of the prism 423. Further, the UV light is refracted and reflected on the slope Sc. Further, the UV light refracted and emitted from the inclined surface Sc is reflected by the vertical surface (mirror surface) Sb ′ of the prism 423 adjacent to the prism. In this way, the UV light travels toward the medium while the optical path is changed. In this improved example, the UV light emitted from the light source 421 is collected around the prism 423, and the spread of the UV light reaching the medium can be suppressed. Therefore, leakage of UV light from the irradiation part 42a can be reduced.

=== Second Embodiment ===
In the first embodiment, only one type of prism 423 is used. On the other hand, in the second embodiment, a rectangular prism 424 is further used in addition to the prism 423.
In the second embodiment, the configuration other than the irradiation unit is the same as that of the first embodiment. Although the configuration of the first irradiation unit 42a will be described here, the other irradiation units have the same configuration.

  FIG. 10 is an explanatory diagram of the configuration of the irradiation unit and UV irradiation according to the second embodiment. In FIG. 10, the same components as those in FIGS. 7 and 9 are denoted by the same reference numerals and description thereof is omitted.

In the second embodiment, a rectangular prism 424 is provided on each prism 423 (between the light source 421 and the prism 423).
The length of the rectangular prism 424 in the transport direction is the same as the length of the plane Sa of the prism 423. Further, both the upstream and downstream surfaces (left and right surfaces in the figure) of each rectangular prism 424 in the transport direction are mirror-coated.
In the second embodiment, the UV light emitted obliquely from the light source 421 is totally reflected by the surfaces at both ends of the rectangular prism 424 and is incident on the prism 423. Further, similarly to the improved example of the first embodiment, the UV light travels toward the medium while being reflected and refracted on the vertical surface Sb ′ and the inclined surface Sc of each prism. As described above, in the second embodiment, by providing the rectangular prism 424 on the upper surface of the prism 423, the spread of the UV light irradiated on the medium is smaller than that in the improved example of the first embodiment (FIG. 9). Become.
Thereby, in 2nd Embodiment, UV light can be converged more and the leakage of UV light from each irradiation part can further be reduced.

=== Third Embodiment ===
In 3rd Embodiment, the structure of the conveyance unit 20 differs from embodiment mentioned above.
FIG. 11 is an explanatory diagram of the third embodiment.

  The transport unit 20 of the third embodiment includes an upstream roller 25A and a downstream roller 25B, and a transport drum 26 that transports a long medium (paper S) wound in a roll shape on the circumferential surface. When a transport motor (not shown) rotates, the upstream roller 25A and the downstream roller 25B rotate, and the transport drum 26 rotates. The paper S that is pressed and supported by the upstream roller 25 </ b> A and the downstream roller 25 </ b> B along the peripheral surface of the transport drum 26 is transported as the transport drum 26 rotates. On the outer side of the transport drum 26, between the upstream roller 25 </ b> A and the downstream roller 25 </ b> B, each head of the head unit 30 and the pre-curing irradiation unit 40 of the irradiation unit 40 are opposed to the peripheral surface of the transport drum 26. The 42 irradiation units are arranged in the same order as in the above-described embodiment. In addition, a main curing irradiation unit 44 is disposed downstream of the downstream roller 25B in the transport direction.

  The paper S transported by the rotation of the transport drum 26 is printed in a printable area (area facing the head) and transported to the downstream roller 25B side. That is, when the transport drum 26 transports the paper S, the paper S moves in the transport direction with respect to each head. Note that the paper S being transported is electrostatically attracted or vacuum attracted to the transport drum 26.

<About print processing>
When the printer 1 of the third embodiment starts printing, the paper S is previously pressed along the peripheral surface of the transport drum 26 and supported by the upstream roller 25A and the downstream roller 25B.

  When the print data is received from the computer 110, the controller 60 rotates the transport drum 26 at a constant speed, and the nozzles of the head K, head C, head M, and head Y while the paper S passes under each head. Ink is ejected intermittently from That is, the dot formation process and the paper S transport process are performed simultaneously. As a result, a dot row composed of a plurality of dots along the transport direction and the paper width direction is formed on the paper S.

  In addition, after ejecting ink from each head, the controller 60 causes each irradiation section (42a to 42d) of the pre-curing irradiation section 42 on the downstream side in the transport direction to perform UV irradiation. Thereby, the dots formed on the paper S by each head are temporarily cured. In this way, dot formation and temporary curing are sequentially performed for each ink color. Finally, the controller 60 causes the main curing irradiation unit 44 to perform UV irradiation for main curing.

In the third embodiment, each head and each irradiation unit are not arranged in a straight line as shown in FIG. 2, but are arranged alternately along the peripheral surface of the transport drum 26 as shown in FIG. For this reason, when UV light leaks from each irradiation part, possibility that a head will be irradiated with UV light will become higher than the case of FIG.
Also in this case, by making the configuration of each irradiation unit the same as in the above-described embodiment, the UV light emitted from the light source 421 of each irradiation unit is gathered inside the irradiation unit, and from each irradiation unit. UV light leakage is reduced. Therefore, in the case of the drum-shaped transport unit as shown in FIG. 11, it is particularly effective if the configuration of each irradiation unit is as in the above-described embodiment.

=== Other Embodiments ===
Although a printer or the like as one embodiment has been described, the above embodiment is for facilitating the understanding of the present invention, and is not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof. In particular, the embodiments described below are also included in the present invention.

<About the printer>
In the above-described embodiment, the printer is described as an example of the liquid ejecting apparatus, but the present invention is not limited to this. For example, color filter manufacturing apparatus, dyeing apparatus, fine processing apparatus, semiconductor manufacturing apparatus, surface processing apparatus, three-dimensional modeling machine, liquid vaporizer, organic EL manufacturing apparatus (particularly polymer EL manufacturing apparatus), display manufacturing apparatus, film formation The same technology as that of the present embodiment may be applied to various devices to which inkjet technology is applied, such as a device and a DNA chip manufacturing device.

<About ink>
In the above-described embodiment, ink (UV ink) that is cured by being irradiated with ultraviolet rays (UV) is ejected from the nozzles. However, the liquid ejected from the nozzle is not limited to such ink, and a liquid that is cured by irradiation with light other than UV (for example, visible light) may be ejected from the nozzle. In this case, light (such as visible light) for curing the liquid may be irradiated from the temporary curing irradiation unit 42 and the main curing irradiation unit 44.
In this embodiment, black, cyan, magenta, and yellow inks are ejected onto the medium, but other colors (for example, white) may be ejected onto the medium. Further, colorless and transparent ink may be ejected onto the medium.

1 printer, 20 transport unit,
23A upstream conveyance roller, 23B downstream conveyance roller,
24 belt, 25A upstream roller, 25B downstream roller,
26 transport drum, 30 head unit, 40 irradiation unit,
42 pre-curing irradiation unit, 42a first irradiation unit, 42b second irradiation unit,
42c third irradiation unit, 42d fourth irradiation unit, 44 main curing irradiation unit,
50 detector groups, 60 controllers, 61 interface units,
62 CPU, 63 memory, 64 unit control circuit,
110 computer, 420 hood, 421 light source,
423 prism, 424 rectangular prism

Claims (5)

A head that ejects a liquid that is cured by irradiation of light toward a medium;
An irradiation unit for irradiating the light;
A liquid ejecting apparatus comprising:
The irradiation unit is
A light source of the light;
A plurality of prisms arranged between the light source and the medium, a first surface perpendicular to the medium, and a second surface in which a distance between the first surface and the first surface decreases as the distance from the light source increases. And a plurality of prisms arranged so that the second surface of each prism is inside the irradiation unit with respect to the first surface;
A liquid ejecting apparatus comprising: The liquid ejecting apparatus according to claim 1,
The liquid ejecting apparatus according to claim 1, wherein a maximum value of a distance between the first surface and the second surface of each prism is shorter than a length of the first surface in a direction perpendicular to the medium. The liquid ejecting apparatus according to claim 1 or 2,
The liquid ejecting apparatus according to claim 1, wherein the first surface is a reflecting surface that reflects all the incident light. The liquid ejecting apparatus according to claim 1,
A liquid ejecting apparatus, further comprising: a rectangular prism having an end surface perpendicular to the medium, between the light source and each of the prisms. The liquid ejecting apparatus according to claim 1,
A cylindrical conveying member that conveys the medium on the peripheral surface,
The liquid ejecting apparatus, wherein the head and the irradiation unit are arranged along the peripheral surface of the transport member.

Images