The present application is based on, and claims priority from JP Application Serial Number 2019-030238, filed Feb. 22, 2019, the disclosure of which is hereby incorporated by reference herein in its entirety.
The disclosure relates to a printing apparatus.
For example, as described in JP-A-2017-196795, there has been hitherto known a printing apparatus including ejection heads that eject a liquid onto a recording medium supported by a support member and prints an image on the recording medium and an irradiation section that irradiates the medium with light for curing the liquid applied on the medium. An inclination part is provided at an irradiation port of the irradiation section. An interval between the inclination part and the support member is reduced as approaching to the ejection heads. The inclination part reduces an amount of the light emitted from the irradiation section, which enters nozzle surfaces to which the ejection heads eject the liquid, and suppresses curing of the liquid on the nozzle surfaces of the ejection heads.
However, it has been confirmed that ink being the liquid adhering to the nozzle surface of each ejection head is cured by a slight amount of leaking light when printing continues for a long time even by adopting the configuration of the printing apparatus described above. Further, it has been confirmed that ink adhering to side surfaces of the ejection heads are also cured. The ink adhering to the side surfaces of the ejection heads are considered as ink mist generated at the time of ejection of the ink. In this case, for example, there is a problem of unstable ejection of the ink when the ink cured on the side surfaces of the ejection heads is wiped off from the ejection heads during maintenance, moves, and adheres to the nozzle surfaces.
A printing apparatus according to the present application includes a support member configured to support, with a curved surface thereof, a recording medium conveyed in a predetermined conveyance direction, an ejection head configured to eject a liquid from a nozzle of a nozzle surface arranged at a position facing the support member to print an image on the recording medium supported by the curved surface, an irradiation section including a housing and a light emitting section configured to emit light for curing the liquid, the light emitting section accommodated inside the housing, the irradiation section configured to irradiate the recording medium supported by the curved surface with the light emitted from the light emitting section through an irradiation port defined by the housing, a first light-shielding plate arranged between the ejection head and the irradiation section in the conveyance direction, and a second light-shielding plate arranged between the first light-shielding plate and the ejection head in the conveyance direction, wherein the housing is arranged in a position far from the curved surface with respect to a virtual tangent plane that passes through a portion, farthest from the irradiation port, of the nozzle surface and is in contact with a lower end of the first light-shielding plate, and the second light-shielding plate is arranged in a position that allows the second light-shielding plate to block at least part of light entering a side surface orthogonal to the nozzle surface of the ejection head among the light that is emitted from the irradiation section and regularly reflected or scattered on the support member or the recording medium supported by the support member, and is arranged in a position so that a distance between a lower end of the second light-shielding plate and the curved surface is equal to or more than a height of the nozzle surface from the curved surface.
In the printing apparatus, an interval between the second light-shielding plate and the curved surface may be the same as an interval between the ejection head and the curved surface.
In the printing apparatus, the first light-shielding plate and the second light-shielding plate may be integrally formed.
In the printing apparatus, the ejection head may be a first ejection head arranged upstream of the irradiation section in the conveyance direction, the first light-shielding plate may be a first upstream light-shielding plate arranged upstream of the irradiation section in the conveyance direction, the second light-shielding plate may be a second upstream light-shielding plate arranged upstream of the first upstream light-shielding plate in the conveyance direction, the virtual tangent plane may be a first virtual tangent plane that passes through a position, farthest from the irradiation port, of the nozzle surface of the first ejection head and is in contact with a lower end of the first light-shielding plate, the printing apparatus may further include a first downstream light-shielding plate arranged downstream of the irradiation section in the conveyance direction, a second ejection head arranged downstream of the first downstream light-shielding plate in the conveyance direction, and a second downstream light-shielding plate arranged between the first downstream light-shielding plate and the second ejection head in the conveyance direction, the housing may be arranged in a position far from the curved surface with respect to a second virtual tangent plane that passes through a portion, farthest from the irradiation port, of the nozzle surface of the second ejection head and is held in contact with a lower end of the first downstream light-shielding plate, and the second downstream light-shielding plate may be arranged in a position that allows the second light-shielding plate to block at least part of light entering a side surface orthogonal to the nozzle surface of the second ejection head among the light that is emitted from the irradiation section and regularly reflected or scattered, and is arranged in a position so that a distance between a lower end of the second downstream light-shielding plate and the curved surface is equal to or more than a height of the nozzle surface from the curved surface.
Exemplary embodiments of the present disclosure will be described below with reference to the accompanying drawings. Note that, in each of the drawings below, to illustrate each of members and the like in a recognizable size, each of the members and the like is illustrated to a scale different from an actual scale.
As illustrated in
As illustrated in
The feeding section 2 includes the feeding shaft 20 around which an edge of the sheet S is wound, and a driven roller 21 on which the sheet S drawn out from the feeding shaft 20 is wound. The feeding shaft 20 supports the sheet S by winding the edge of the sheet S around the feeding shaft 20 with the front surface of the sheet S facing outward. In addition, when the feeding shaft 20 is rotated clockwise in
While supporting the sheet S fed from the feeding section 2 by a front surface 30a (also referred to as a curved surface 30a) of a platen drum 30 being a support member, the process section 3 prints an image on the sheet S by performing processing as appropriate with the process unit 3U arranged along the front surface 30a of the platen drum 30. In the process section 3, the front driving roller 31 and a rear driving roller 32 are provided on both sides of the platen drum 30. The sheet S conveyed from the front driving roller 31 to the rear driving roller 32 is supported by the platen drum 30, and subjected to image printing.
The front driving roller 31 has a plurality of minute protrusions formed on the outer circumferential surface thereof by thermal spraying, and winds, from the back surface side, the sheet S fed from the feeding section 2. In addition, the front driving roller 31 is rotated clockwise in the drawing sheet of
The platen drum 30 is a cylindrical drum supported rotatably around a rotary shaft 301 extending in the +Y direction and the −Y direction by a support mechanism (not illustrated), and winds the sheet S conveyed from the front driving roller 31 to the rear driving roller 32 from the back surface side. The platen drum 30 supports the sheet S by the front surface (curved surface) 30a of the platen drum 30 from the back surface side of the sheet S while being driven to rotate in a conveyance direction Ds of the sheet S by receiving a frictional force between the platen drum 30 and the sheet S. The process section 3 is provided with driven rollers 33 and 34 that fold back the sheet S on both sides of the part at which the sheet S is wound on the platen drum 30. Of these driven rollers, the front surface of the sheet S is wound on the driven roller 33 between the front driving roller 31 and the platen drum 30 to fold back the sheet S. Meanwhile, the front surface of the sheet S is wound on the driven roller 34 between the platen drum 30 and the rear driving roller 32 to fold back the sheet S. In this way, by folding back the sheet S upstream and downstream of the platen drum 30 in the conveyance direction Ds, the long part at which the sheet S is wound on the platen drum 30 can be secured.
The rear driving roller 32 has a plurality of minute protrusions formed on the outer circumferential surface thereof by thermal spraying, and winds, from the back surface side, the sheet S conveyed from the platen drum 30 via the driven roller 34. In addition, the front driving roller 32 is rotated clockwise in the drawing sheet of
In this way, the sheet S conveyed from the front driving roller 31 to the rear driving roller 32 is supported by the front surface 30a of the platen drum 30. In addition, in the process section 3, in order to print a color image on the front surface of the sheet S supported by the platen drum 30, the process unit 3U is provided. The process unit 3U includes a front plate 35a and a rear plate 35b that are paired on the front side and the rear side, respectively. The plates 35a and 35b each have an arc shape along the front surface 30a of the platen drum 30, and constitute a unit frame by being coupled to each other by a coupling member (not illustrated). In addition, ejection heads 36a to 36e, UV lamps 37a and 37b, and head movement mechanisms, and the like that are structural elements of the process unit 3U are attached to the unit frame as described below.
The four ejection heads 36a to 36d corresponding to yellow, cyan, magenta, and black are aligned in the conveyance direction Ds in the stated color order. More specifically, these four ejection heads 36a to 36d are oriented to the platen drum 30, and arranged radially from the rotary shaft 301 of the platen drum 30. Further, the two ejection heads 36a and 36b arranged upstream in the conveyance direction Ds among the ejection heads 36a to 36d are moved by one head movement mechanism, and positioned with respect to the sheet S wound on the platen drum 30. Further, the two ejection heads 36c and 36d arranged downstream are moved by another head movement mechanism, and positioned with respect to the sheet S wound on the platen drum 30. Further, these two head movement mechanisms move and position the four ejection heads 36a to 36d. With this, a distance between a nozzle tip (an ejection port of ink) of a nozzle surface 39 (
Note that, in the ejection heads 36a to 36e in the present exemplary embodiment, a plurality of unit heads are arrayed in two rows in a staggered pattern in the +Y direction and the −Y direction orthogonal to the conveyance direction Ds. In each of the plurality of unit heads, a plurality of nozzles aligned in the +Y direction and the −Y direction are open. In this way, the nozzle surface 39 of each of the ejection heads 36a to 36e is provided with the plurality of nozzles in the +Y direction and the −Y direction.
As a liquid such as an ink and a recording liquid used in the ejection heads 36a to 36d, an ultraviolet (UV) ink (photocurable ink), which is cured by being irradiated with ultraviolet rays (light), is used. Thus, in order to cure and fix the ink onto the sheet S, the process unit 3U is provided with the UV lamps 37a and 37b being irradiation sections. Note that, the ink curing is performed at two separate stages of temporary curing and final curing. The UV lamps 37a for temporary curing are each arranged between the plurality of corresponding ejection heads 36a to 36d. In other words, the UV lamps 37a are used for curing (performing temporary curing of) the ink to such a degree that the ink does not lose its shape by emitting relatively weak ultraviolet rays, and are not used for completely curing the ink. Meanwhile, the UV lamp 37b for final curing is provided downstream of the plurality of ejection heads 36a to 36d in the conveyance direction Ds. Specifically, the UV lamp 37b is used for completely curing (performing final curing of) the ink by emitting ultraviolet rays stronger than those of the UV lamps 37a. By performing temporary curing and final curing as described above, the color image formed by the plurality of ejection heads 36a to 36d can be fixed onto the front surface of the sheet S.
Furthermore, the ejection head 36e is provided downstream of the UV lamp 37b in the conveyance direction Ds. The ejection head 36e faces the front surface of the sheet S wound on the platen drum 30 with slight clearance, and ejects a clear UV ink onto the front surface of the sheet S by an ink jet method. Specifically, the clear ink is further ejected onto the color image formed by the ejection heads 36a to 36d in four colors. Note that, a proper value is set to a paper gap of the ejection head 36e by moving and positioning the ejection head 36e alone by another head movement mechanism different from the head movement mechanisms that have been already described.
In this way, the ejection heads 36a to 36e, the UV lamps 37a and 37b, and the head movement mechanisms are attached to the unit frame and constitute the process unit 3U. When a normal operation, namely, printing processing is performed, the process unit 3U is positioned between the feeding section 2 and the winding section 4 as indicated by solid lines in
In the process section 3, a UV lamp 38 is provided downstream of the ejection head 36e in the conveyance direction Ds. The UV lamp 38 is used for completely curing (performing final curing of) the clear ink ejected by the ejection head 36e by emitting strong ultraviolet rays. With this, the clear ink can be fixed onto the front surface of the sheet S.
The sheet S on which the color image is formed by the process section 3 is conveyed to the winding section 4 by the rear driving roller 32. In addition to the winding shaft 40 around which the edge of the sheet S is wound, the winding section 4 includes a driven roller 41 for winding, from the back surface side, the sheet S between the winding shaft 40 and the rear driving roller 32. The winding shaft 40 supports the sheet S by winding the edge of the sheet S around the winding shaft 40 with the front surface of the sheet S facing outward. Specifically, when the winding shaft 40 is rotated clockwise in the drawing sheet of
Next, a configuration of the UV lamp 37a will be described, and a positional relationship between the ejection heads 36a and 36b and the UV lamp 37a will also be described.
As illustrated in
Further, in the present exemplary embodiment, a first upstream light-shielding plate 70a being a first light-shielding plate is arranged between the ejection head 36a being a first ejection head, which is arranged upstream of the UV lamp 37a, and the UV lamp 37a in the conveyance direction Ds of the sheet S. Further, a second upstream light-shielding plate 77a being a second light-shielding plate is arranged between the first upstream light-shielding plate 70a and the ejection head 36a in the conveyance direction Ds of the sheet S.
Further, a first downstream light-shielding plate 70b is arranged downstream of the UV lamp 37a in the conveyance direction Ds of the sheet S. Further, the ejection head 36b being a second ejection head is arranged downstream of the first downstream light-shielding plate 70b in the conveyance direction Ds of the sheet S. Further, a second downstream light-shielding plate 77b is arranged between the first downstream light-shielding plate 70b and the ejection head 36b. Thus, along the conveyance direction Ds of the sheet S, the ejection head 36a, the second upstream light-shielding plate 77a, the first upstream light-shielding plate 70a, the UV lamp 37a, the first downstream light-shielding plate 70b, the second downstream light-shielding plate 77b, and the ejection head 36b are arranged in the stated order.
The first upstream light-shielding plate 70a and the first downstream light-shielding plate 70b are plate-shaped members that prevent the UV light emitted through the irradiation port 373 of the UV lamp 37a from entering the nozzle surfaces 39 of the ejection heads 36a and 36b. In the present exemplary embodiment, the first upstream light-shielding plate 70a and the first downstream light-shielding plate 70b are arranged by being fixed to a frame for supporting the housing 371. Further, as illustrated in
Note that, on a liner virtual line connecting one end of the first upstream light-shielding plate 70a and the center of the rotary shaft 301 with each other, the gap G1 corresponds to a gap between the one end of the first upstream light-shielding plate 70a and a part the curved surface 30a that intersects with the virtual line. On a linear virtual line connecting the center of the nozzle surface 39 in the conveyance direction Ds and the center of the rotary shaft 301, the gap G2 corresponds to a gap between the center of the nozzle surface 39 in the conveyance direction Ds and a part of the curved surface 30a that intersects with the imaginary line. In other words, in
Herein, when the housing 371 of the UV lamp 37a is arranged inside a region A1 indicated by lines diagonally to the lower right in
Thus, in the exemplary embodiment, as illustrated in
In this way, the housing 371 of the UV lamp 37a is arranged in the position far from the front surface 30a of the platen drum 30 with respect to the two planes, namely, the first virtual tangent plane P1 and the second virtual tangent plane P2. Thus, the first upstream light-shielding plate 70a and the first downstream light-shielding plate 70b can block the scattered light near the irradiation port 373 in the housing 371 from directly entering the nozzle surfaces 39, and part of light scattered by shining on the housing 371 can be prevented from directly entering the nozzle surfaces 39 of the ejection heads 36a and 36b.
Further, the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b are arranged in positions capable of blocking at least part of light entering side surfaces 59 orthogonal to the nozzle surfaces 39 of the ejection heads 36a and 36b among the UV light that is emitted by the UV lamp 37a and regularly reflected or scattered on the platen drum 30 or the sheet S supported by the platen drum 30, and are arranged in positions at which a gap G3 between each of lower ends 78a and 78b of the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b and the curved surface 30a is equal to or more than a height of the nozzle surfaces 39 from the curved surface 30a (the gap G2). In the present exemplary embodiment, the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b are plate-shaped members, and the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b are arrayed to face the side surfaces 59 of the ejection heads 36a and 36b facing the UV lamp 37a. In the present exemplary embodiment, the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b are arranged by being fixed to the frame for supporting the housing 371. Note that, on linear virtual lines connecting the lower ends 78a and 78b of the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b and the center of the rotary shaft 301, the gap G3 corresponds to a gap between each of the lower ends 78a and 78b of the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b, and the parts of the curved surface 30a that intersect with the virtual lines. In other words, in
In the present exemplary embodiment, the gap G3 between each of the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b, and the curved surface 30a of the platen drum 30, (the gap G3) is the same as the gap G2 between the nozzle surface 39 of the ejection head 36a and the curved surface 30a of the platen drum 30 (the gap G2). With this, while preventing the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b from being held in contact with the sheet S supported by the curved surface 30a of the platen drum 30, the reflected light or the scattered light can be prevented from entering the side surfaces 59 of the ejection heads 36a and 36b as much as possible. Therefore, curing of ink adhering to the side surfaces 59 of the ejection heads 36a and 36b, which is caused by part of the scattered light entering the side surfaces 59 of the ejection heads 36a and 36b, can be prevented.
Note that, a positional relationship between the ejection heads 36b and 36c, and the UV lamp 37a arranged therebetween, a positional relationship between the ejection heads 36c and 36d, and the UV lamp 37a arranged therebetween, a positional relationship between the ejection heads 36d and 36e, and the UV lamp 37b arranged therebetween, and a positional relationship between the first upstream light-shielding plate 70a and the first downstream light shielding plate 70b, and the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b are substantially similar to the positional relationship between the ejection heads 36a, 36b and the UV lamp 37a arranged therebetween and the positional relationship between the first upstream light-shielding plate 70a and the first downstream light shielding plate 70b, and the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b that have already been described. Thus, detailed description therefor is omitted.
Next, a configuration of the maintenance section 5 will be described.
As illustrated in
The maintenance section 5 includes a movable body 710 including the wiper 711, a cap 712, and a support member 713 that movably supports the wiper 711 and the cap 712 in an integrated manner, the drive motor that moves the movable body 710 in a wiping direction Dw including the conveyance direction Ds along the nozzle surface 39, a cleaning liquid supply pipe 730 that jets a cleaning liquid through jetting ports 730a, and a housing 740. Each of these members is formed to have a length in the +Y direction and the −Y direction to be equal to or more than the ejection head 36b, and hence is capable of performing maintenance to the entire nozzle surface 39. Moreover, the wiper 711 is moved in the wiping direction Dw while wiping surfaces 711a and 711b abut against the nozzle surface 39. With this, the wiping processing is performed. Further, the cap 712 is held in close contact with the nozzle surface 39 so as to cover all the nozzles, and hence capping is performed.
The cleaning liquid supply pipe 730 is open to the ejection head 36b side, includes the plurality of jetting ports 730a along the +Y direction and the −Y direction, and is capable of jetting the cleaning liquid to the side surface 59 being a supplied surface of the ejection head 36b on the cleaning liquid supply pipe 730 side when the ejection head 36b is at the cleaning position close to the maintenance section 5. As the cleaning liquid to be supplied to the wiping processing, a liquid having a suitable cleaning function may be used. When a UV ink is used as in the present exemplary embodiment, a solvent capable of dissolving a cured UV ink may be used. Examples of such solvent include Ethyl Di Glycol Acetate (EDGAC), a clear UV ink, and the like. Further, a cleaning liquid obtained by adding a surfactant or a polymerization inhibitor to such solvent may be used. Supply of the cleaning liquid from the cleaning liquid supply pipe 730 is configured to be switchable. Note that, the drive motor and the like are controlled by a control unit (not illustrated).
The housing 740 mainly includes a bottom surface 740a substantially parallel to the wiping direction Dw, a side wall 740b that stands vertically from one end of the bottom surface 740a in the wiping direction Dw, and an eave 740c that extends from an upper end of the side wall 740b along the wiping direction Dw in the same direction as the bottom surface 740a. The bottom surface 740a is provided in a range slightly larger than a range in which the movable body 710 is movable in the wiping direction Dw, and receives a waste liquid including the ink, the cleaning liquid, and the like, which is generated at the time of maintenance. The waste liquid received on the bottom surface 740a is discharged from the maintenance section 5 through a discharge port 740d formed in the bottom surface 740a. The eave 740c has a dimension in the wiping direction Dw, which is larger than the movable body 710. Further, during the printing operation, the movable body 710 maintains a state of being covered by the eave 740c at a standby position below the eave 740c. In this manner, the eave 740c blocks the UV light emitted from the UV lamps 37a, 37b, and 38, and prevents the UV ink adhering to the wiper 711 and the cap 712 from being cured.
Next, an operation at the time of the wiping processing will be described.
As illustrated in
Subsequently, a cleaning liquid CL is jetted from the jetting ports 730a of the cleaning liquid supply pipe 730 to the side surface 59 of the ejection head 36b. The cleaning liquid jetted from the jetting ports 730a passes above the wiper 711, and lands on the side surface 59 without landing on the wiper 711. Then, when the cleaning liquid CL is jetted on the side surface 59, the cleaning liquid CL adhering to the side surfaces 59 flows downward along the side surface 59, and stagnates at a corner 66 between the side surface 59 and the nozzle surface 39.
Subsequently, the wiper 711 is moved from the starting point Q1 to the terminal point Q2, and performs wiping. During this process, as illustrated in
Here, for example, when ink mist generated at the time of ejecting the ink from the ejection head 36b adheres to the side surface 59 or receives reflected light or scattered light, the ink mist adhering to the side surface 59 is cured. When the wiping processing is performed in such a state, the ink cured on the side surface 59 is wiped off by the wiper 711 during the wiping processing. Then, the cured ink that is wiped off is conveyed to the nozzle surface 39 along with the movement of the wiper 711 and clogs the nozzles, which may cause an ejection defect. However, in the present exemplary embodiment, the second downstream light-shielding plate 77b is arranged, and hence the reflected light or the scattered light toward the side surface 59 of the ejection head 36b is blocked. With this, the ink mis adhering to the side surfaces 59 is not cured, is removed easily with the cleaning liquid CL during the wiping processing, and is prevented from clogging the nozzles due to the wiping processing.
After that, the ejection head 36b is temporarily moved to the retracting position, and then is returned to the height of the cleaning position again. The ejection head 36b is temporarily moved to the retracting position as described above, which cancels a state in which the wiper 711 positioned at the terminal point Q2 is curved leftward. Further, the ejection head 36b is returned to the height of the cleaning position, the wiper 711 is curved rightward, and then the wiper 711 is moved from the terminal point Q2 to the starting point Q1. With this, the nozzle surface 39 is wiped.
According to the present exemplary embodiment described above, the following effects can be obtained.
In the printing apparatus 1, the housing 371 of the UV lamp 37a is arranged in the position far from the front surface 30a of the platen drum 30 with respect to the two planes, namely, the first virtual tangent plane P1 and the second virtual tangent plane P2. Thus, the first upstream light-shielding plate 70a and the first downstream light-shielding plate 70b can block the scattered light that is scattered by shining on the housing 371 near the irradiation port 373 of the UV lamp 37a, and can prevent part of the scattered light from the housing 371 from directly entering the nozzle surfaces 39 of the ejection heads 36a and 36b. Therefore, curing of ink adhering to the nozzle surfaces 39 of the ejection heads 36a and 36b, which is caused by part of the scattered light entering the nozzle surfaces 39 of the ejection heads 36a and 36b, can be prevented.
Further, the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b can block the reflected light or the scattered light on the side surfaces 59 of the ejection heads 36a and 36b. Therefore, curing of ink adhering to the side surfaces 59 of the ejection heads 36a and 36b, which is caused by part of the scattered light entering the side surfaces 59 of the ejection heads 36a and 36b, can be prevented.
In the manner described above, the liquid can be stably ejected from the ejection heads 36a and 36b.
Next, a second exemplary embodiment will be described.
In the first exemplary embodiment, the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b are arrayed to face the side surfaces 59 of the ejection heads 36a and 36b. In the present exemplary embodiment, as illustrated in
The second upstream light-shielding plate 77a is a plate-shaped member. Further, a surface of the second upstream light-shielding plate 77a on the downstream side in the conveyance direction Ds is arranged to be inclined while facing the curved surface 30a. Further, the second downstream light-shielding plate 77b is also a plate-shaped member. Further, a surface of the second downstream light-shielding plate 77b on the upstream in the conveyance direction Ds is arranged to be inclined while facing the curved surface 30a.
The second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b are arranged in positions at which the gap G3 between each of the lower ends 78a and 78b of the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b, and the curved surface 30a is equal to or more than the height of the nozzle surfaces 39 from the curved surface 30a (the gap G2). In the present exemplary embodiment, the gap G3 between each of the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b, and the curved surface 30a of the platen drum 30, (the gap G3) is the same as the gap G2 between the nozzle surface 39 of the ejection head 36a and the curved surface 30a of the platen drum 30 (the gap G2). With this, while preventing the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b from being held in contact with the sheet S supported by the curved surface 30a of the platen drum 30, the reflected light or the scattered light can be prevented from entering the side surfaces 59 of the ejection heads 36a and 36b as much as possible. Therefore, curing of ink adhering to the side surfaces 59 of the ejection heads 36a and 36b, which is caused by part of the scattered light entering the side surfaces 59 of the ejection heads 36a and 36b, can be prevented.
According to the present exemplary embodiment described above, the following effects can be obtained in addition to the effects described above.
The second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b are arranged to be inclined. Thus, outer shapes of the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b can be relatively small, and hence space reduction can be achieved.
Next, a third exemplary embodiment will be described.
Note that, the arrangement method of the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b in the printing apparatus 1B according to the present exemplary embodiment is different from the configuration of the first exemplary embodiment. Thus, the configuration other than the arrangement method of the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b is the same as the configuration of the first exemplary embodiment, and hence description therefor is omitted.
As illustrated in
Similarly, the second downstream light-shielding plate 77b and the first downstream light-shielding plate 70b are integrally formed. Specifically, the second downstream light-shielding plate 77b in an inclined state is integrated with the first downstream light-shielding plate 70b. More specifically, the second downstream light-shielding plate 77b is a plate-shaped member, and the surface of the second downstream light-shielding plate 77b on the upstream in the conveyance direction Ds, which is inclined while facing the curved surface 30a, is integrated with the first downstream light-shielding plate 70b.
Note that, the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b are arranged in positions at which the gap G3 between each of the lower ends 78a and 78b of the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b, and the curved surface 30a is equal to or more than the height of the nozzle surfaces 39 from the curved surface 30a (the gap G2). In the present exemplary embodiment, the gap G3 between each of the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b, and the curved surface 30a of the platen drum 30, (the gap G3) is the same as the gap G2 between the ejection head 36a and the curved surface 30a of the platen drum 30 (the gap G2). With this, while preventing the second upstream light-shielding plate 77a and the second downstream light-shielding plate 77b from being held in contact with the sheet S supported by the curved surface 30a of the platen drum 30, the reflected light or the scattered light can be prevented from entering the side surfaces 59 of the ejection heads 36a and 36b as much as possible. Therefore, curing of ink adhering to the side surfaces 59 of the ejection heads 36a and 36b, which is caused by part of the scattered light entering the side surfaces 59 of the ejection heads 36a and 36b, can be prevented.
Further, as illustrated in
According to the present exemplary embodiment described above, the following effects can be obtained in addition to the effects described above.
The second upstream light-shielding plate 77a and the first upstream light-shielding plate 70a, and the second downstream light-shielding plate 77b and the first downstream light-shielding plate 70b, which are integrally formed, are easily mounted.
Note that, the present disclosure is not limited to the exemplary embodiments described above, and various modifications and improvements can be added to the above-described exemplary embodiments. Modification examples will be given below.
In the exemplary embodiments, the configuration in which the ejection heads 36a and 36b are arranged on the upstream and the downstream side of the UV lamp 37a, respectively, is described. However, the exemplary embodiments are not limited thereto. For example, a configuration in which, for example, the ejection head 36a is arranged only on any one of the upstream and the downstream side of the UV lamp 37a may be adopted. Further, the first upstream light-shielding plate 70a being a first light-shielding plate is arranged between the ejection head 36a and the UV lamp 37a in the conveyance direction Ds. Further, the second upstream light-shielding plate 77a being a second light-shielding plate is arranged between the first upstream light-shielding plate 70a and the ejection head 36a. Even with such a configuration, effects similar to those described above can be obtained.
In the exemplary embodiments, description is made on the printing apparatus 1 of a so-called drum type using the platen drum 30. The disclosure is also applicable to a printing apparatus 1C different from the drum-type printing apparatus 1.
Thus, in the printing apparatus 1C having such a configuration, the housing 151 of the UV lamp 150 is arranged in a position far from the front surface 121 of the rear roller 120 with respect to a virtual tangent plane P that passes through a portion of the nozzle surface 141 of the ejection head 140 being farthest from the irradiation port 153 of the UV lamp 150 and that is held in contact with a lower end 161 of the first light-shielding plate 160. In this manner, when the housing 151 of the UV lamp 150 is arranged in the position far from the front surface 121 of the rear roller 120 with respect to the virtual tangent plane P, the first light-shielding plate 160 can block all light scattered by shining on the housing 151 of the UV lamp 150 near the irradiation port 153 of the UV lamp 150, and can prevent part of the scattered light from the housing 151 from entering the nozzle surface 141 of the ejection head 140.
Further, in the conveyance directions DS1 and DS2, a second light-shielding plate 165 is arranged between the first light-shielding plate 160 and the ejection head 140. The configuration of the second light-shielding plate 165 is the same as the configuration of the second upstream light-shielding plate 77a in the exemplary embodiments. In this manner, the second light-shielding plate 165 can block reflected light or scattered light on the side surface 149 of the ejection head 140. Therefore, curing of ink adhering to the side surface 149 of the ejection head 140, which is caused by part of the scattered light entering the side surface 149 of the ejection head 140, can be prevented.
Contents derived from the exemplary embodiments will be described below.
A printing apparatus includes a support member configured to support, with a curved surface thereof, a recording medium conveyed in a predetermined conveyance direction, an ejection head configured to eject a liquid from a nozzle of a nozzle surface arranged at a position facing the support member to print an image on the recording medium supported by the curved surface, an irradiation section including a housing and a light emitting section configured to emit light for curing the liquid, the light emitting section accommodated inside the housing, the irradiation section configured to irradiate the recording medium supported by the curved surface with the light emitted from the light emitting section through an irradiation port defined by the housing, a first light-shielding plate arranged between the ejection head and the irradiation section in the conveyance direction, and a second light-shielding plate arranged between the first light-shielding plate and the ejection head in the conveyance direction, wherein the housing is arranged in a position far from the curved surface with respect to a virtual tangent plane that passes through a portion of the nozzle surface being farthest from the irradiation port and is held in contact with a lower end of the first light-shielding plate, and the second light-shielding plate is arranged in a position capable of blocking at least part of light entering a side surface orthogonal to the nozzle surface of the ejection head among the light that is emitted from the irradiation section and regularly reflected or scattered on the support member or the recording medium supported by the support member, and is arranged in a position so that a distance between a lower end of the second light-shielding plate and the curved surface is equal to or more than a height of the nozzle surface from the curved surface.
With this configuration, the housing of the irradiation section is arranged in the position far from the curved surface of the support member supporting the recording medium with respect to the virtual tangent plane that passes through the portion of the nozzle surface of the ejection head being farthest from the irradiation port of the irradiation section and is held in contact with the lower end of the first light-shielding plate. Thus, the first light-shielding plate can block almost all the scattered light near the irradiation port, and part of the scattered light can be prevented from entering the nozzle surface of the ejection head. Therefore, curing of ink adhering to the nozzle surface, which is caused by part of the scattered light entering the nozzle surface of the ejection head, can be prevented.
Further, the second light-shielding plate can block the reflected light or the scattered light on the side surface of the ejection head. Therefore, curing of ink adhering to the side surface of the ejection head, which is caused by part of the scattered light entering the side surface of the ejection head, can be prevented.
In the manner described above, the liquid can be stably ejected from the ejection head.
In the printing apparatus, an interval between the second light-shielding plate and the curved surface may be the same as an interval between the ejection head and the curved surface.
With this configuration, while preventing the second light-shielding plates from being held in contact with the recording medium supported by the curved surface of the support member, the reflected light or the scattered light can be prevented from entering the side surfaces of the ejection heads as much as possible.
In the printing apparatus, the first light-shielding plate and the second light-shielding plate may be integrally formed.
With this configuration, the first light-shielding plate and the second light-shielding plate are easily mounted.
In the printing apparatus, the ejection head may be a first ejection head arranged upstream of the irradiation section in the conveyance direction, the first light-shielding plate may be a first upstream light-shielding plate arranged upstream of the irradiation section in the conveyance direction, the second light-shielding plate may be a second upstream light-shielding plate arranged upstream of the first upstream light-shielding plate in the conveyance direction, the virtual tangent plane may be a first virtual tangent plane that passes through a position of the nozzle surface of the first ejection head being farthest from the irradiation port and is held in contact with a lower end of the first light-shielding plate, the printing apparatus may further include a first downstream light-shielding plate arranged downstream of the irradiation section in the conveyance direction, a second ejection head arranged downstream of the first downstream light-shielding plate in the conveyance direction, and a second downstream light-shielding plate arranged between the first downstream light-shielding plate and the second ejection head in the conveyance direction, the housing may be arranged in a position far from the curved surface with respect to a second virtual tangent plane that passes through a portion, farthest from the irradiation port, of the nozzle surface of the second ejection head and is held in contact with a lower end of the first downstream light-shielding plate, and the second downstream light-shielding plate may be arranged in a position capable of blocking at least part of light entering a side surface orthogonal to the nozzle surface of the second ejection head among the light that is emitted from the irradiation section and regularly reflected or scattered, and is arranged in a position so that a distance between a lower end of the second downstream light-shielding plate and the curved surface is equal to or more than a height of the nozzle surface from the curved surface.
With this configuration, the housing of the irradiation section is arranged in the position far from the curved surface of the support member supporting the recording medium with respect to the two virtual tangent planes (the first virtual tangent plane located upstream of the irradiation section and the second virtual target plane located downstream of the irradiation section). Thus, the first upstream light-shielding plate and the first downstream light-shielding plate can block almost all the scattered light near the irradiation port, and part of the scattered light can be prevented from entering the nozzle surfaces of the first ejection head and the second ejection head. Therefore, curing of ink adhering to the nozzle surfaces, which is caused by part of the scattered light entering the nozzle surfaces of the first ejection head and the second ejection head, can be prevented.
Further, the second upstream light-shielding plate and the second downstream light-shielding plate can block the reflected light or the scattered light on the side surfaces of the first ejection head and the second ejection head. Therefore, curing of ink adhering to the side surfaces of the first ejection head and the second ejection head, which is caused by part of the scattered light entering the side surfaces of the first ejection head and the second ejection head, can be prevented. Therefore, for example, even when the ejection heads are wiped during maintenance of the first ejection head and the second ejection head, the liquid adhering to the side surfaces of the first ejection head and the second ejection head can be removed easily.
In the manner described above, the liquid can be stably ejected from the first ejection head and the second ejection head.
Number | Date | Country | Kind |
---|---|---|---|
JP2019-030238 | Feb 2019 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
20160167399 | Ohnishi | Jun 2016 | A1 |
20170313100 | Hori | Nov 2017 | A1 |
Number | Date | Country |
---|---|---|
2007-203624 | Aug 2007 | JP |
2015-009376 | Jan 2015 | JP |
2017-196795 | Nov 2017 | JP |
Number | Date | Country | |
---|---|---|---|
20200269606 A1 | Aug 2020 | US |