Printing device

Abstract

The printing apparatus (100) includes: a printhead (30) that ejects ink capable of being cured by irradiation towards a mounting surface (11a) of a mounting medium (M); a light irradiation device (50) arranged with the printhead (30) to irradiate light from a light-emitting area (51b) disposed on an irradiation surface (51a) opposite to the mounting surface (11a) towards the mounting surface (11a) to cure the ink; and electrostatic flocking portions (45, 55) disposed at least partially on the opposite portion between the light-emitting area (51b) and the printhead (30) opposite to the mounting surface (11a), wherein the electrostatic flocking portions (45, 55) suppress the generation of stray light irradiated toward the printhead.

Description

Technical Field

[0001] This invention relates to a printing apparatus. Background Technology

[0002] Printing apparatuses of the ink-curing type are known (for example, see Patent Document 1). These apparatuses spray ultraviolet-curable ink, for example, from a printhead onto a medium to be printed. The ink is cured by irradiating the sprayed ink with ultraviolet light through a light irradiation device.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2004-314304 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In the aforementioned printing apparatus, a portion of the ultraviolet light emitted by the light irradiation device may become stray light. For example, a portion of the emitted ultraviolet light may be reflected by the medium, and the ultraviolet light reflected by the medium may be reflected by the opposing surface of the light irradiation device. The ultraviolet light may reach the printhead through repeated reflections. If such stray light irradiates the printhead, there is a possibility that the ink in the printhead may solidify, causing ink clogging.

[0008] The present invention was made in view of the above circumstances, and its object is to provide a printing apparatus capable of suppressing the generation of stray light.

[0009] Solution for solving the problem

[0010] The printing apparatus of the present invention comprises: a printhead that ejects ink capable of being cured by irradiation toward a mounting surface of a mounting medium; a light irradiation device arranged with the printhead that irradiates light from a light-emitting area disposed on an irradiation surface opposite to the mounting surface toward the mounting surface to cure the ink; and an electrostatic flocking portion disposed at least partially on an opposing portion between the light-emitting area and the printhead opposite to the mounting surface.

[0011] In the above-described printing apparatus, the electrostatic flocking portion is disposed over the entire area of ​​the nozzle side in the irradiation surface, which is located in the light-emitting region.

[0012] In the above-described printing apparatus, the irradiation surface is planar and is arranged at an angle such that the end on the nozzle side is positioned lower than the end on the side opposite to the nozzle.

[0013] In the above-mentioned printing device, the printing device also includes a pipe disposed between the printhead and the light irradiation device, having a suction port for drawing mist generated by the printhead.

[0014] In the above-mentioned printing device, the light irradiation device has a light source that emits the light and a cooling fan that cools the light source, and the pipe is connected to the negative pressure side of the cooling fan.

[0015] In the above-described printing apparatus, the electrostatic flocking portion is disposed in the portion of the pipe opposite to the mounting surface.

[0016] The effects of the invention

[0017] According to the present invention, the generation of stray light can be suppressed. Attached Figure Description

[0018] Figure 1 This is a perspective view showing an example of the printing apparatus of this embodiment.

[0019] Figure 2 This is a diagram showing an example of the configuration of nozzles, pipes, and light irradiation devices.

[0020] Figure 3 This is a diagram showing an example of the configuration of nozzles, pipes, and light irradiation devices.

[0021] Figure 4 This is a diagram illustrating one example of the operation of the comparative printing device.

[0022] Figure 5 This diagram illustrates an example of the operation of the printing apparatus according to this embodiment. Detailed Implementation

[0023] Hereinafter, embodiments of the printing apparatus of the present invention will be described based on the accompanying drawings. Furthermore, these embodiments illustrate one aspect of the present invention and do not limit the invention. Additionally, the constituent elements in the following embodiments include elements that can and are easily substituted by those skilled in the art, or substantially the same elements.

[0024] Figure 1 This is a perspective view showing an example of the printing apparatus 100 of this embodiment. Figure 1 As shown, the printing device 100 is an inkjet printing device, comprising a main body 10, an ink supply unit 20, a printhead 30, a conduit 40, and a light irradiation device 50. Various forms of such a printing device 100, such as vertical and flatbed types, can be cited.

[0025] The main body 10 includes a media support 11 and a media drive 12. The media support 11 supports the media M on the mounting surface 11a. The media drive 12 moves the media M in the media transport direction D2. The media transport direction D2 is orthogonal to the main scanning direction D1. The main scanning direction D1 and the media transport direction D2 are both orthogonal to the vertical direction.

[0026] The ink supply unit 20 has, for example, an ink container (not shown). The ink contained in the ink container is supplied to the printhead 30 via a supply path (not shown) and ejected from the printhead 30 as droplets.

[0027] Figure 2 and Figure 3 This is a diagram showing an example of the configuration of the nozzle 30, the pipe 40, and the light irradiation device 50. Figure 2 This is a view of carriage 60 from the side. Figure 3 This is a view of carriage 60 from below. (See diagram.) Figure 2 and Figure 3 As shown, the nozzle 30, pipe 40, and light irradiation device 50 are mounted on the carriage 60 and arranged in the main scanning direction D1. The nozzle 30, pipe 40, and light irradiation device 50 move integrally with the carriage 60 in the main scanning direction D1.

[0028] For example, multiple printheads 30 are arranged in the main scanning direction D1. Each printhead 30 has a nozzle surface 31 opposite to the mounting surface 11a. The nozzle surface 31 is, for example, planar. Multiple nozzles (not shown) for ejecting ink are provided on the nozzle surface 31. Examples of inks include ultraviolet-curable inks. Types of ultraviolet-curable inks include, for example, white ink, cyan (C), magenta (M), yellow (Y), and black (K) coloring inks, transparent inks, etc., which can be appropriately used depending on the color of the image formed on the medium M. The printheads 30 and the control unit CONT (see reference) Figure 1 The printhead 30 is electrically connected and its drive is controlled by the control unit CONT. The printhead 30 reciprocates along the main scanning direction D1 while ejecting ink toward the medium M placed on the mounting surface 11a by moving the carriage 60.

[0029] The light irradiation device 50 irradiates the ultraviolet-curable ink ejected onto the medium M with ultraviolet light. The light irradiation device 50 is, for example, composed of an LED module capable of irradiating ultraviolet light. The light irradiation device 50 is mounted on a carriage 60, and as the carriage 60 moves along the main scanning direction D1, the light irradiation device 50 can reciprocate in the main scanning direction D1. The light irradiation device 50 and the control unit CONT (see reference) Figure 1 The electrical connection is controlled by the control unit CONT.

[0030] like Figure 2As shown, the light irradiation device 50 has a housing 51. An irradiation surface 51a is provided on the housing 51, opposite to the mounting surface 11a. The irradiation surface 51a is, for example, planar. The irradiation surface 51a is inclined such that its end on the nozzle 30 side in the main scanning direction D1 is positioned lower than its end on the side opposite to the nozzle 30. That is, the irradiation surface 51a is inclined toward the side opposite to the nozzle 30.

[0031] like Figure 3 As shown, a light-emitting region 51b is provided on the irradiation surface 51a. The light-emitting region 51b is a partial opening area provided on the irradiation surface 51a. The light-emitting region 51b is provided, for example, at the center of the irradiation surface 51a along the main scanning direction D1, extending along the medium transport direction D2. The light-emitting region 51b irradiates ultraviolet light onto the mounting surface 11a. A plurality of light sources 52 are disposed on the housing 51. The plurality of light sources 52 are arranged in a matrix on the substrate 53 in the light-emitting region 51b. The plurality of light sources 52 are arranged to overlap with the light-emitting region 51b when viewed from the vertical direction. The plurality of light sources 52 are, for example, LED chips, and are arranged with their respective light-emitting surfaces facing the side of the light-emitting region 51b (lower side in the vertical direction).

[0032] like Figure 2 As shown, multiple light sources 52 and a substrate 53 (see reference) are provided inside the housing 51 for cooling. Figure 3 The cooling fan 54 is disposed above the substrate 53. The cooling fan 54 sprays air toward the substrate 53. When the cooling fan 54 is operating, the space 51K inside the housing 51, above the cooling fan 54, that is, on the side opposite to the substrate 53, becomes negative pressure.

[0033] like Figure 3 As shown, an electrostatic flocking portion 55 is disposed in the outer region 51c of the irradiation surface 51a, excluding the light-emitting region 51b. The electrostatic flocking portion 55 is disposed throughout the entire area of ​​the outer region 51c. The electrostatic flocking portion 55 is formed, for example, using a material such as nylon. The electrostatic flocking portion 55 is formed, for example, by applying an adhesive to the entire surface of the outer region 51c and attaching short fibrous flocking material using a direct current voltage or the like. The length (vertical direction) dimension of the flocking material constituting the electrostatic flocking portion 55 is, for example, 0.1 mm to 3.0 mm, and preferably 0.2 mm to 1.0 mm.

[0034] The conduit 40 is positioned between the nozzle 30 and the light irradiation device 50 along the main scanning direction D1. The conduit 40 has a pipe component 41. For example... Figure 2As shown, the tube member 41 has a first end 41a on its upper side in the vertical direction and a second end 41b on its lower side. The first end 41a is mounted on the upper part of the housing 51 and communicates with the internal space 51K of the housing 51. That is, the first end 41a is connected to the internal space 51K of the housing 51, which is under negative pressure by the cooling fan 54. The second end 41b of the tube member 41 has a bottom surface 41d opposite to the mounting surface 11a and a suction port 41c located on the upper side of the bottom surface 41d and opening on the nozzle 30 side. As ink is ejected from the nozzle 30, ink mist sometimes floats around the nozzle 30. The tube 40 draws the misty ink (ink mist) from the suction port 41c.

[0035] like Figure 3 As shown, an electrostatic flocking portion 45 is disposed on the bottom surface 41d of the second end 41b. The electrostatic flocking portion 45 is disposed over the entire area of ​​the bottom surface 41d. The electrostatic flocking portion 45, like the electrostatic flocking portion 55 described above, is formed using, for example, a material such as nylon. The electrostatic flocking portion 45 is formed, for example, by applying an adhesive to the entire surface of the bottom surface 41d and attaching short fibrous flocking material using a direct current voltage or the like. The length dimension of the flocking material constituting the electrostatic flocking portion 45 is, for example, 0.1 mm to 3.0 mm, and preferably 0.2 mm to 1.0 mm.

[0036] The pipe 40 has a tilt adjustment part 42. The tilt adjustment part 42 can be, for example, constructed by a connecting member that connects the second end 41b to a portion of the pipe member 41 that is higher than the second end 41b. For example, by applying a force of a certain degree or more, the second end 41b can be rotated about the connecting member (see reference). Figure 5 (A single-dot dashed line). The inclination of the second end 41b of the pipe 40 relative to the vertical direction can be adjusted using the tilt adjustment part 42. By adjusting the inclination of the second end 41b of the pipe 40, the opening direction of the suction port 41c can be changed. In addition, by adjusting the inclination of the second end 41b, the inclination of the bottom surface 41d relative to the mounting surface 11a can be changed.

[0037] For example, the pipe 40 can be tilted at its second end 41b so that the opening direction of the suction port 41c faces downwards towards the printhead 30 side. In this case, ink mist from the printhead 30 side can be efficiently suctioned. Furthermore, in this case, the end of the bottom surface 41d on the main scanning direction D1 of the printhead 30 side is tilted such that it is positioned lower than the end on the opposite side of the printhead 30. That is, the bottom surface 41d is tilted towards the side opposite to the printhead 30.

[0038] Next, an example of the operation of the printing apparatus 100 configured as described above will be explained. The printing apparatus 100 is in a state in which the medium M is pre-loaded onto the mounting surface 11a of the medium support portion 11.

[0039] In this state, for example, when an instruction to perform a printing operation is received from an external device, the control unit CONT moves the carriage 60 in the main scanning direction D1. The movement of the carriage 60, in conjunction with the control unit CONT, causes ink to be ejected from the printhead 30 and irradiated with ultraviolet light by the light irradiation device 50. Additionally, the control unit CONT activates the cooling fan 54 of the light irradiation device 50. Through this operation, ink adheres to the medium M, and the adhered ink is irradiated with ultraviolet light. Furthermore, ink mist floating between the printhead 30 and the medium M, or between the printhead 30 and the mounting surface 11a, is drawn from the suction port 41c of the conduit 40. The control unit CONT repeats the above operations while moving the medium M in the medium transport direction D2. Through this control, an image is formed on the medium M.

[0040] Figure 4 This is a diagram illustrating one example of the operation of the comparative printing device. Figure 4 This indicates the state in which the medium M is placed on the mounting surface 16a of the medium support portion 16 in the printing apparatus 100A of the comparative example.

[0041] In this state, a portion of the ultraviolet light emitted from the light irradiation device 50A, for example, that travels towards the nozzle 30A, is reflected by the medium M. This reflected ultraviolet light LA ​​sometimes reaches the outer region 56c of the light irradiation device 50A. The ultraviolet light LA ​​reaching the outer region 56c is sometimes reflected by this outer region 56c, and the reflected ultraviolet light LA ​​is again reflected by the medium M and travels towards the nozzle 30A.

[0042] In this way, the ultraviolet light LA ​​irradiated by the medium M is repeatedly reflected between the medium M and the outer region 56c, thus allowing the ultraviolet light LA ​​to travel towards the nozzle 30A. Similarly, through repeated reflection between the medium M and the bottom surface 46d of the pipe 40, the ultraviolet light LA ​​further travels towards the nozzle 30A. Thus, the ultraviolet light LA ​​irradiated by the light irradiation device 50A traveling towards the nozzle 30A may become stray light and reach the nozzle surface 31A of the nozzle 30A. Due to the irradiated stray light, the ink held on the nozzle surface 31A may solidify.

[0043] Figure 5 This diagram illustrates an example of the operation of the printing apparatus according to this embodiment. Figure 5 This indicates the state in which the medium M in the printing apparatus 100 of this embodiment is placed on the mounting surface 11a of the medium support portion 11.

[0044] In this embodiment, an electrostatic flocking portion 55 is provided in the outer region 51c of the housing 51 of the light irradiation device 50. Therefore, when the component L of ultraviolet light emitted from the light irradiation device 50 that is reflected by the medium M reaches the outer region 51c, at least a portion of the ultraviolet light L is absorbed by the electrostatic flocking portion 55. Thus, it is possible to suppress the reflection of ultraviolet light L that has reached the outer region 51c from that region. Therefore, the electrostatic flocking portion 55 can attenuate the ultraviolet light L during the repeated reflections between the outer region 51c and the medium M. Thus, it is possible to suppress stray light of ultraviolet light L from traveling towards the nozzle 30 and reaching the nozzle surface 31.

[0045] Furthermore, the irradiation surface 51a of the light irradiation device 50 is tilted toward the side opposite to the nozzle 30. This structure can suppress the reflection of ultraviolet L from the outer region 51c of the irradiation surface 51a toward the nozzle 30.

[0046] Furthermore, in this embodiment, an electrostatic flocking portion 45 is also provided on the bottom surface 41d of the duct 40 located between the light irradiation device 50 and the nozzle 30 in the main scanning direction D1. As a result, at least a portion of the ultraviolet light L reaching the bottom surface 41d of the duct 40 is absorbed by the electrostatic flocking portion 45. Therefore, the reflection of ultraviolet light L reaching the bottom surface 41d of the duct 40 by the bottom surface 41d can be suppressed. Thus, the electrostatic flocking portion 45 can attenuate the ultraviolet light L during the repeated reflections between the bottom surface 41d and the medium M. Therefore, stray light from the ultraviolet light L can be suppressed from reaching the nozzle 30. Additionally, by adjusting the inclination of the second end 41b side of the tube member 41, the bottom surface 41d can be oriented towards the side opposite to the nozzle 30. Therefore, the reflection of ultraviolet light L from the bottom surface 41d towards the nozzle 30 can be suppressed.

[0047] As described above, the printing apparatus 100 of this embodiment has, for example, the following structure.

[0048] (1) The printing apparatus 100 includes a printhead 30, a light irradiation device 50, and electrostatic flocking parts 45 and 55. The printhead 30 ejects ink that can be cured by irradiation with ultraviolet light toward the mounting surface 11a of the mounting medium M. The light irradiation device 50 is arranged with the printhead 30, and irradiates the mounting surface 11a with ultraviolet light (light) that cures the ink from the light-emitting area 51b disposed on the irradiation surface 51a opposite to the mounting surface 11a. The electrostatic flocking parts 45 and 55 are disposed at least partially on the opposite portion (irradiation surface 51a, bottom surface 41d) between the light-emitting area 51b and the printhead 30 opposite to the mounting surface 11a in the main scanning direction D1.

[0049] According to this structure, when ultraviolet light L reflected by the medium M reaches the opposite portion (irradiation surface 51a, bottom surface 41d) opposite the mounting surface 11a, a portion of the ultraviolet light is absorbed at the electrostatic flocking portions 45 and 55. Therefore, it is possible to suppress the reflection of ultraviolet light L that has reached the opposite portion by that opposite portion. Consequently, during the period when ultraviolet light L that has reached the opposite portion is repeatedly reflected between that opposite portion and the medium M, the ultraviolet light L can be attenuated, thereby suppressing ultraviolet light L from reaching the nozzle 30 as stray light.

[0050] (2) In the printing apparatus 100 of this embodiment, the electrostatic flocking part 55 can be provided throughout the entire area of ​​the irradiation surface 51a on the side of the nozzle 30 located in the light-emitting area 51b. As an example, the electrostatic flocking part 55 can be provided in the entire area of ​​the outer region 51c of the irradiation surface 51a other than the light-emitting area 51b.

[0051] According to this structure, the electrostatic flocking part 55 can absorb and attenuate the ultraviolet L emitted from the light-emitting region 51b in the irradiation surface 51a and reflected by the medium M to the portion of the outer region 51c near the nozzle 30. Furthermore, since the electrostatic flocking part 55 is formed in the entire area of ​​the outer region 51c near the nozzle 30 compared to the light-emitting region 51b, there is no need for masks or similar processes, allowing the electrostatic flocking part 55 to be formed with fewer steps.

[0052] (3) In the printing apparatus 100 of this embodiment, the irradiation surface 51a is planar. The irradiation surface 51a is arranged at an angle such that the end of the nozzle 30 side in the main scanning direction D1 is located lower than the end of the opposite side of the nozzle 30. According to this structure, it is possible to suppress the reflection of ultraviolet L reaching the irradiation surface 51a towards the nozzle 30 side.

[0053] (4) The printing apparatus 100 of this embodiment includes a conduit 40. The conduit 40 is disposed between the printhead 30 and the light irradiation device 50 in the main scanning direction D1. The conduit 40 has a suction port 41c for drawing out the mist generated from the printhead 30. According to this structure, ink mist can be drawn out by the conduit 40, thus suppressing the adhesion of ink mist to the electrostatic flocking parts 45 and 55. As a result, the reduction in the ultraviolet absorption rate of the electrostatic flocking parts 45 and 55 can be suppressed.

[0054] (5) In the printing apparatus 100 of this embodiment, the light irradiation device 50 includes a light source 52 that emits light and a cooling fan 54 that cools the light source 52. The duct 40 is connected to the negative pressure side of the cooling fan 54. According to this structure, ink mist can be efficiently drawn in by utilizing the negative pressure generated by the cooling fan 54.

[0055] (6) In the printing apparatus 100 of this embodiment, the electrostatic flocking part 45 is disposed in the bottom surface 41d of the conduit 40 opposite to the mounting surface 11a. According to this structure, the electrostatic flocking part 45 can absorb a portion of the ultraviolet L that reaches the bottom surface 41d of the conduit 40.

[0056] The scope of the present invention is not limited to the above-described embodiments, and appropriate modifications can be made without departing from the spirit of the invention. For example, in the above embodiments, the structure in which the electrostatic flocking portion 55 is formed across the entire outer region 51c of the irradiation surface 51a in the light irradiation device 50 has been described as an example, but it is not limited thereto. The electrostatic flocking portion 55 may also be a structure provided only in, for example, the outer region 51c, in the region on the nozzle 30 side relative to the light-emitting region 51b in the main scanning direction D1.

[0057] Furthermore, in the above embodiment, an example was given of a structure in which electrostatic flocking portions 45 and 55 are respectively provided in the pipe 40 and the light irradiation device 50, but it is not limited to this. For example, it is also possible to have a structure in which neither electrostatic flocking portion 45 nor electrostatic flocking portion 55 is provided.

[0058] Furthermore, in the above embodiment, the bottom surface 41d of the pipe 40 and the outer region 51c of the light irradiation device 50 were described as examples of the opposing portions between the light-emitting region 51b and the nozzle 30, opposite to the mounting surface 11a, but this is not a limitation. Other structures opposite to the mounting surface 11a may also be arranged between the light-emitting region 51b and the nozzle 30. In this case, at least a partial electrostatic flocking portion can be arranged in the opposing portion opposite to the mounting surface 11a in such other structures.

[0059] Furthermore, in the above embodiments, an example of a structure in which a conduit 40 is arranged between the nozzle 30 and the light irradiation device 50 has been described, but this is not a limitation. For example, the description in the above embodiments can be applied even in a structure in which a conduit 40 is not arranged between the nozzle 30 and the light irradiation device 50.

[0060] Furthermore, in the above embodiment, the example given is a structure in which the light irradiation device 50 is disposed on only one side of the nozzle 30 in the main scanning direction D1, but this is not a limitation. It could be a structure in which the light irradiation device 50 is disposed on only one side of the nozzle 30 in the main scanning direction D1, different from the above embodiment, or it could be a structure in which the light irradiation device 50 is disposed on both sides of the nozzle 30 in the main scanning direction D1.

[0061] Furthermore, in the above embodiment, an example of a structure in which the nozzle 30 is not provided with an electrostatic flocking part was described, but it is not limited to this. It is also possible for an electrostatic flocking part to be provided in the nozzle 30 from the end in the main scanning direction D1 to the nozzle surface 31.

[0062] Explanation of reference numerals in the attached figures

[0063] D1, Main scanning direction; D2, Media movement direction; M, Media; CONT, Control unit; 10, Main body; 11, Media support unit; 11a, Mounting surface; 12, Media drive unit; 20, Ink supply unit; 30, Printhead; 31, Nozzle surface; 40, Pipe; 41, Pipe component; 41a, First end; 41b, Second end; 41c, Suction port; 41d, Bottom surface; 45, 55, Electrostatic flocking part; 50, Light irradiation device; 54, Housing; 51a, Irradiation surface; 51b, Light-emitting area; 51c, Outer area; 52, Light source; 53, Substrate; 54, Cooling fan; 60, Carriage; 100, Printing device.

Claims

1. A printing apparatus, wherein, The printing device has the following features: The nozzle sprays ink that can be cured by irradiation toward the surface of the substrate. A light irradiation device, arranged with the nozzle, irradiates the ink from a light-emitting area on an irradiation surface opposite to the mounting surface toward the mounting surface, causing the ink to cure; and An electrostatic flocking portion is disposed on the entire outer surface of the irradiated surface, located outside the light-emitting area. The irradiation surface is generally planar, and is arranged at an angle such that the end on the nozzle side is positioned lower than the end on the opposite side of the nozzle. Corresponding to the angle of the irradiation surface, the light-emitting area irradiates light in a direction that is angled towards the side opposite to the nozzle. To suppress stray light, the length dimension of the flocking material constituting the electrostatic flocking part is 0.1mm to 3.0mm.

2. The printing apparatus according to claim 1, wherein, The printing device also includes a conduit disposed between the printhead and the light irradiation device, having a suction port for drawing in the mist generated by the printhead.

3. The printing apparatus according to claim 2, wherein, The light irradiation device has a light source that emits the light and a cooling fan that cools the light source, and the pipe is connected to the negative pressure side of the cooling fan.

4. The printing apparatus according to claim 2 or 3, wherein, The electrostatic flocking part is disposed in the portion of the pipe opposite to the mounting surface.

Images