The present disclosure relates to a liquid discharge head and a liquid discharge apparatus including the liquid discharge head.
The recent ink jet printer field requires liquid discharge apparatuses capable of outputting high-quality print. However, if liquid discharge ports are continuously kept in contact with air for a long time, evaporation of the liquid causes thickening and sticking, which leads to a discharge failure, making it impossible to output high-quality print. To reduce or eliminate the liquid thickening and sticking due to the evaporation of the liquid, known circulating liquid discharge apparatuses circulate liquid.
For example, Japanese Patent Laid-Open No. 2017-124617 discloses a liquid discharge head, as well as a liquid discharge apparatus, including highly densely arranged discharge ports, in which a plurality of common supply channels and a plurality of common collecting channels are provided in the discharge port array to circulate liquid through pressure chambers corresponding to the plurality of discharge ports.
In a conventional liquid discharge apparatus having a liquid discharge head, interruption of circulation of liquid can cause sticking due to evaporation of the liquid, resulting in a discharge failure. When the circulation of the liquid is at a stop, liquid in a certain area may be less likely to be diffused than being evaporated from a discharge port, which can cause liquid sticking at the dead end, resulting in a discharge failure.
In particular, in a conventional serial liquid discharge head that discharges liquid while scanning a medium, if stopped during the scanning because of a trouble during printing, discharge ports may be left in contact with air for a long period of time. Therefore, the liquid sticking and discharge failure described above are more likely to occur.
The present disclosure provides a liquid discharge head and a liquid discharge apparatus in which liquid sticking and discharge failure can be reduced or eliminated.
According to an aspect of the present disclosure, a liquid discharge head includes a discharge port array in which a plurality of discharge ports configured to discharge liquid is arrayed, a plurality of pressure chambers individually communicating with the plurality of discharge ports, a common supply channel configured to supply liquid to the plurality of pressure chambers, and a supply port array in which a plurality of supply ports configured to supply liquid to the common supply channel is arrayed, wherein the discharge port array and the supply port array extend from a first end of the liquid discharge head to a second end of the liquid discharge head, wherein the plurality of discharge ports in the discharge port array includes a first-end discharge port closest to the first end and a second-end discharge port closest to the second end, wherein the plurality of supply ports in the supply port array includes a first-end supply port closest to the first end and a second-end supply port closest to the second end, and wherein, as seen from a position facing openings of the plurality of discharge ports, an end of an opening of the first-end supply port adjacent to the first end is at a position nearer to the first end than an end of an opening of the first-end discharge port adjacent to the first end.
Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Embodiments of the present disclosure will be described hereinbelow with reference to the drawings. It is to be understood that the following embodiments do not limit the present disclosure and that not all of combinations of the features described in the embodiments are absolutely necessary for the solution of the present disclosure. Like components are denoted by like reference signs.
The liquid discharge head 1 is mounted on a mount (a carriage 60). The carriage moves back and forth in the main scanning direction (X-direction) along a guide shaft 51. The recording medium P is conveyed in a sub-scanning direction (Y-direction) intersecting (in this example, at right angles) the main scanning direction by conveying rollers 55, 56, 57, and 58. The liquid discharge head 1 is detachably attached to the carriage 60 by the user.
The liquid discharge head 1 includes a circulation unit 54 and a discharge unit 3, described below. The discharge unit 3 includes a plurality of discharge ports for discharging liquid and energy generating elements that generate discharge energy for discharging liquid from the individual discharge ports, the specific configuration of which will be described below.
The liquid discharge apparatus 50 includes an ink tank 2, which is an ink supply source, and an external pump 21. The ink stored in the ink tank 2 is supplied to the circulation unit 54 through ink supply tubes 59 with the driving force of the external pump 21.
The liquid discharge apparatus 50 forms a predetermined image on the recording medium P by repeating a recording scanning operation in which the liquid discharge head 1 mounted on the carriage 60 discharges ink while moving back and forth in the main scanning direction and a conveying operation of conveying the recording medium P in the sub-scanning direction. The liquid discharge head 1 of this embodiment is capable of discharging four kinds of ink, black (K), cyan (C), magenta (M), and yellow (Y), and can record a full-color image with the inks. The ink that the liquid discharge head 1 can discharge is not limited to the above four kinds of ink. The present disclosure is also applicable to liquid discharge heads for discharging other kinds of ink. In other words, the kind and number of inks discharged from the liquid discharge head are not limited. In the case where a cap member (not shown) is disposed off the conveying path of the recording medium P, when no printing operation is to be performed, the cap member is relatively moved to a position where the face of the liquid discharge head 1 is to be covered to prevent the discharge ports from drying, or a sucking operation is performed for charging or recovery.
In
The bottom 113 of the casing 110 connects to a supporting member 210 on which a discharge module 300, to be described later, is mounted. The ink supplied to the circulation units 54a to 54d is supplied to the supporting member 210 through the casing 110. In
The supporting member 210 includes a plurality of supporting member supply ports 212 and a plurality of supporting member collection ports 211. The liquid supplied from the liquid discharge apparatus 50 to the liquid discharge head 1 or the liquid supplied from the circulation unit 54 is supplied to the discharge module 300 through the supporting member supply ports 212. The liquid not discharged by the discharge module 300 is collected to the circulation unit 54 through the supporting member collection ports 211. If the liquid discharge head 1 does not include the circulation unit 54, the liquid may be collected by a circulation unit outside the liquid discharge head 1.
The discharge module 300 is a unit serving as a liquid discharge head, and the discharge module 300 itself is also referred to as a liquid discharge head. The discharge module 300 is a lamination of an opening plate 310, a channel plate 320, and a nozzle plate 330 layered in this order from the supporting member 210. These plates are superposed and joined so that the liquid channels communicate to constitute the discharge module 300 and are supported by the supporting member 210.
The opening plate 310 includes, on a surface adjacent to the supporting member 210, a supply port array in which supply ports 312 communicating with the supporting member supply ports 212 are arrayed and a collection port array in which collection ports 311 communicating with the supporting member collection ports 211 are arrayed. The supply port array is an array of a plurality of supply ports for supplying liquid to one common supply channel 322, described later. Likewise, the collection port array is an array of a plurality of collection ports for collecting liquid from one common collecting channel 321, described later.
Although
The channel plate 320 includes, on a surface adjacent to the opening plate 310, a common supply channel 322 communicating with the supporting member supply ports 212 and a common collecting channel 321 communicating with the supporting member collection ports 211. The channel plate 320 includes, on a surface adjacent to the nozzle plate 330, individual supply channels 324 each connecting the common supply channel 322 with a pressure chamber 325 (
In other words, the liquid in the discharge module 300 circulates through the supply port 312, the common supply channel 322, the individual supply channel 324, the pressure chamber 325, the individual collecting channel 323, the common collecting channel 321, and the collection port 311 in this order. The presence of the common supply channel 322 and the individual supply channel 324 allows the liquid flowing from the supply port 312 to be directed to the position where the discharge port 331 is formed. Likewise, the presence of the common collecting channel 321 and the individual collecting channel 323 allows the liquid not discharged from the discharge port 331 to be directed to the position where the collection port 311 is formed. The supply ports 312 and the collection ports 311 of the opening plate 310 are formed in a staggered arrangement. If not in the staggered arrangement, the supply ports 312 and the collection ports 311 may be arranged in parallel in a straight line, as shown in
As shown in
The supply channel for supplying liquid supplies the liquid from a portion where the supporting member supply port 212 of the supporting member 210 and the supply port 312 of the opening plate 310 are superposed and communicate with each other, as shown in
Since the discharge ports 331 are disposed in the paths connecting the individual supply channels 324 and the individual collecting channels 323, flows from the individual supply channels 324 to the individual collecting channels 323 are generated in the pressure chambers 325 in the vicinity of the discharge ports 331. The flows are generated over the length from the first end to the second end of the discharge port array. This increases the liquid circulation efficiency to keep the liquid in the pressure chambers 325 constantly fresh, thereby preventing issues, such as thickening and sticking due to evaporation.
The known opening plate 810 shown in
In the present disclosure, the discharge port array of the discharge ports 331 and the supply port array of the plurality of supply ports 312 extend in the Y-direction from a first end 300a to a second end 300b of the discharge module 300 (liquid discharge head). The plurality of discharge ports 331 in the discharge port array includes a first-end discharge port 331c disposed closest to the first end 300a and a second-end discharge port 331d disposed closest to the second end 300b. The plurality of supply ports 312 in the supply port array includes a first-end supply port 312c disposed closest to the first end 300a and a second-end supply port 312d disposed closest to the second end 300b. In this embodiment, a partial area of the opening of the first-end supply port 312c is formed outside an end 331a of the opening of the first-end discharge port 331c in the Y-direction. In other words, an end 312a of the opening of the first-end supply port 312c adjacent to the first end 300a (hereinafter referred to as “first-side end”) is nearer to the first end 300a than a first-side end 331a of the opening of the first-end discharge port 331c seen from a position facing the opening of the discharge ports 331. The end of the opening of the supply port and the end of the opening of the discharge port are respectively closest to the first end 300a or the second end 300b of the discharge module 300 among the respective openings. This is the same for the collection ports 311 as for the supply ports 312.
In
The above configuration has no dead end (the area B in
Here, the common supply channel 322 communicating with the supply ports 312 may extend outward in the Y-direction from the first end or the second end of the discharge port array. In other words, the length of the common supply channel 322 may be larger than the length T of the discharge port array in the direction in which the supply port array extends.
With this configuration of the supply ports 312 and the common supply channel 322, the supply ports 312 and the common supply channel 322 located outside the discharge port array are present also at a position not overlapping with the energy generating elements 36 that generate heat to discharge liquid in the vertical direction. This allows the liquid not heated by the energy generating elements 36 to be supplied to the pressure chambers 325 through the supply ports 312 and the common supply channel 322 located outside the discharge port array. Accordingly, fresh liquid at near room temperature not heated by the energy generating elements 36 can be supplied to the ends of the discharge ports 331.
Even without the dead end (area B) in
In
The second end 300b, with the same configuration as the first end 300a, increases the effect of the present disclosure. In other words, a partial area of the opening of the second-end supply port 312d may be formed outside an end 331b of the opening of the second-end discharge port 331d in the Y-direction. In other words, the second-side end 312b of the opening of the second-end supply port 312d may be formed at a position nearer to the second end 300b than the second-side end 331b of the opening of the second-end discharge port 331d.
The entire area of the opening of the second-end supply port 312d may be formed the end 331b of the opening of the second-end discharge port 331d in the Y-direction. In other words, the first-side end 312a of the opening of the second-end supply port 312d is formed at a position nearer to the second end 300b than the second-side end 331b of the opening of the second-end discharge port 331d.
In this embodiment, the collection ports 311, with the same configuration as the supply ports 312, increase the effect of the present disclosure. In other words, the collection ports 311, formed outside the discharge port array, also have no dead end in the common collecting channel 322 between the collection ports 311 and the discharge ports 331. This allows the liquid in the area C to be collected to the two collection ports 311 during liquid circulation. When the circulation is at a stop, only the area C where the liquid is supplied from the two collection ports 311 because of the diffusion of the liquid is formed from the collection ports 311 to the discharge ports 331 in the common collecting channel 322. This reduces the possibility of blocking of the liquid flow, reducing or eliminating liquid sticking and discharge failure.
The plurality of collection ports 311 in the collection port array includes a first-end collection port 311c closest to the first end 300a and a second-end collection port 311d. A partial area of the opening of the first-end collection port 311c may be formed outside the end 331a of the opening of the first-end discharge port 331c in the Y-direction. In other words, the first-side end 311a of the opening of the first-end collection port 311c may be formed nearer to the first end 300a than the first-side end 331a of the opening of the first-end discharge port 331c.
Furthermore, the entire area of the opening of the first-end collection port 311c may be formed outside the end 331a of the opening of the first-end discharge port 331c in the Y-direction. In other words, a second-side end 311b of the opening of the first-end collection port 311c may be at a position nearer to the first end 300a than the first-side end 331a of the opening of the first-end discharge port 331c.
The collection ports 311 on the second end 300b, with the same configuration as on the first end 300a, further improve the effect of the present disclosure. In other words, a partial area of the opening of the second-end collection port 311d may be formed outside the end 331b of the opening of the second-end discharge port 331d in the Y-direction. In other words, the second-side end 311b of the opening of the second-end collection port 311d may be formed at a position nearer to the second end 300b than the second-side end 331b of the opening of the second-end discharge port 331d.
Furthermore, the entire area of the opening of the second-end collection port 311d may be formed outside the end 331b of the opening of the second-end discharge port 331d in the Y-direction. In other words, a first-side end 311a of the opening of the second-end collection port 311d is formed at a position nearer to the second end 300b than the second-side end 331b of the opening of the second-end discharge port 331d.
Even without the dead end (area B) in
The configuration in which the collection ports 311 at the opposite ends of the collection port array are nearer to the opposite ends of the discharge module 300 than the discharge ports 331 produces the effect of easily removing bubbles and foreign particles generated at the ends of the discharge port array, the common collecting channel, and the collection port array.
In
Since the liquid that has passed through the supply ports 312 are generally discharged from the discharge ports 331, the liquid flowing through the collection ports 311 is less than the liquid flowing through the supply ports 312. For this reason, the number of supply ports 312 may be larger than the number of collection ports 311. In this case, the common supply channel 322 may be longer than the common collecting channel 321 in the direction in which the discharge port array extends to prevent a dead end from being formed in the common collecting channel 321.
The number of supply ports 312 communicating with one common supply channel 322 and the number of collection ports 311 communicating with one common collecting channel 321 may be the same for symmetry of the design. The supply ports 312 and the collection ports 311 may be formed in a staggered arrangement at positions where the opposite ends of the common supply channel 322 and the opposite ends of the common collecting channel 321 are not aligned in the direction in which the discharge port array extends.
In this embodiment, the supply ports 312 and the collection ports 311, the common supply channel 322 and the common collecting channel 321, the individual supply channels 324 and the individual collecting channels 323 may be formed at inverted positions. Also in this case, forming at least one of the supply ports 312 and the collection ports 311 nearer to the opposite ends of the discharge module 300 than the discharge port array prevents a dead end to be formed, providing the effect of the present disclosure.
In a liquid discharge apparatus including a serial liquid discharge head, if a trouble such as a paper jam occurs during printing to stop the liquid discharge head halfway through scanning, the power source is automatically turned off for safety to stop the circulation of the liquid. If the issue cannot be immediately addressed, the off state is left, and the discharge ports of the liquid discharge head are left in contact with air, which may cause liquid thickening and sticking due to evaporation, resulting in a discharge failure. Accordingly, the liquid discharge head of an embodiment of the present disclosure may be incorporated in a liquid discharge apparatus including a serial liquid discharge head.
The above configuration prevents a dead end from being formed in a common channel from the supply port or the collection port to the discharge port, thereby reducing or eliminating sticking of liquid and a discharge failure.
The configuration of a discharge module 300 according to a second embodiment of the present disclosure will be described. In the following description, only the difference from the first embodiment will be mainly described, and description of the same parts as in the first embodiment will be omitted.
With the above configuration, even if the openings of the plurality of supply ports and the openings of the plurality of collection ports are aligned in the direction in which the discharge port array extends, no dead end is formed, thereby reducing liquid sticking and discharge failure.
Combinations of the configurations of the above embodiments are also applicable.
While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2022-091391, filed Jun. 6, 2022, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
---|---|---|---|
2022-091391 | Jun 2022 | JP | national |