Patent Application
20240066887
The present application claims priority to Korean Patent Application No. 10-2022-0105744, filed Aug. 23, 2022, the entire contents of which is incorporated by reference herein for all purposes.
The present disclosure relates to an inkjet head unit capable of forming high-resolution pixels on a substrate and inkjet printing equipment including the same.
The manufacture of displays involves a plurality of processing steps for forming a device for light emission on a substrate (transparent glass). The processing steps may include, for example, coating, exposure, deposition, cleaning, etching, and the like. Each processing step may be sequentially performed by manufacturing equipment disposed in a display manufacturing plant. In addition, as another processing step, there has been introduced an inkjet printing technique that forms a film or pattern by ejecting droplets (ink) onto a substrate.
An inkjet printing process works by ejecting ink onto a substrate. Conventionally, in order to eject the ink onto the substrate, inkjet printing equipment is disposed in a display manufacturing plant, and the inkjet printing process for the substrate is performed by the inkjet printing equipment. Meanwhile, along with increasing user demand for large-sized devices, the production of large-sized substrates is increasing. Thus, a need exists for a method capable of efficiently performing inkjet printing on a substrate.
The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and is not intended to mean that the present disclosure falls within the purview of the related art that is already known to those skilled in the art.
Accordingly, the present disclosure has been made keeping in mind the above problems occurring in the related art, and the present disclosure provides an inkjet head unit capable of forming high-resolution pixels on a substrate and inkjet printing equipment including the same.
In order to achieve the above objective, according to one aspect of the present disclosure, there is provided an inkjet head unit of inkjet printing equipment, the inkjet head unit including: a head pack including a plurality of ejection heads configured to eject ink of the same color to a substrate; and a head base on which a plurality of head packs are installed to be repeatedly coaxially arranged in color order.
According an embodiment of the present disclosure, the head packs may include: a first head pack including a plurality of ejection heads configured to eject ink corresponding to a first color; a second head pack including a plurality of ejection heads configured to eject ink corresponding to a second color; and a third head pack including a plurality of ejection heads configured to eject ink corresponding to a third color.
According an embodiment of the present disclosure, a head pack set in which the first head pack, the second head pack, and the third head pack are sequentially arranged may be repeatedly installed on the head base.
According an embodiment of the present disclosure, the substrate may be configured to be moved along a first axial direction, and the head packs may be arranged along a second axial direction orthogonal to the first axial direction.
According an embodiment of the present disclosure, the head base may be configured to be moved along the second axial direction.
According an embodiment of the present disclosure, the head packs may be arranged on the head base to have a length equal to a length of the substrate in the second axial direction.
According an embodiment of the present disclosure, each of the ejection heads of each of the head packs may include a plurality of nozzles arranged to overlap each other along the first axial direction, and each of the head packs and another head pack may be arranged so as to not overlap each other along the first axial direction.
According to another aspect of the present disclosure, there is provided inkjet printing equipment including: a stage configured to support a substrate; an inkjet head unit configured to eject ink onto the substrate; and a gantry provided as a structure on which the inkjet head unit is installed. The inkjet head unit may include: a head pack including a plurality of ejection heads configured to eject ink of the same color to a substrate; a head base on which a plurality of head packs are installed to be repeatedly coaxially arranged in color order; and a head frame on which the head packs are installed, and coupled to the gantry.
According to another aspect of the present disclosure, there is provided inkjet printing equipment including: a stage configured to support a substrate configured to be moved along a first axial direction; an inkjet head unit configured to eject ink onto the substrate; a gantry provided as a structure on which the inkjet head unit is installed; and an ink inspection camera configured to inspect a state of the ink ejected on the substrate. The inkjet head unit may include: a head pack including a plurality of ejection heads configured to eject ink of the same color to a substrate; a head base on which a plurality of head packs are installed to be repeatedly arranged in color order along a second axial direction orthogonal to the first axis direction; and a head frame on which the head packs are installed, and coupled to the gantry.
According to an embodiment of the present disclosure, the inkjet head unit may further include: an ink reservoir configured to store the ink supplied to the head pack; and a pressure controller configured to control an ejection pressure of the ink.
According to an embodiment of the present disclosure, the inkjet head unit may further include: an ink reservoir configured to store the ink supplied to the head pack; and a pressure controller configured to control an ejection pressure of the ink. The inkjet head unit may further include a circulation pipe configured to circulate remaining ink used in the ejection heads to the ink reservoir. A filter or a degassing device for maintaining a state of ink may be provided in the circulation pipe.
According to an embodiment of the present disclosure, the inkjet printing equipment may further include a flatness inspection camera installed on the head frame and configured to inspect an alignment state of the ejection heads.
According to the present disclosure, the plurality of head packs each having the plurality of ejection heads ejecting ink of the same color onto the substrate are repeatedly coaxially arranged in color order. Thus, it is possible to immediately identify a head pack and a nozzle that have ejected ink on the substrate, thereby enabling quick nozzle inspection and maintenance.
Due to such a reduction in time for nozzle inspection and maintenance, it is possible to increase utilization of the nozzles and increase yield and lifespan. Furthermore, inkjet printing is performed on the entire area of the substrate and the substrate does not need to be divided into a plurality of printing areas. Thus, it is possible to reduce an axial movement amount. Also, it is possible to reduce the overall weight of the equipment.
The above and other objectives, features, and other advantages of the present disclosure will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which:
Hereinbelow, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings such that the present disclosure can be easily embodied by one of ordinary skill in the art to which the present disclosure belongs. The present disclosure may be embodied in many different forms and is not limited to the embodiments set forth herein.
For clarity, a description of parts not related to describing the present disclosure is omitted here, and the same reference numerals are allocated to the same or similar components throughout the disclosure.
Components having the same structure in various embodiments will be allocated the same reference numeral and explained only in a representative embodiment, and components which are different from those of the representative example will be described in the other embodiments.
As used herein, when an element is referred to as being “connected to” (or coupled to) another element, the element can be directly connected (coupled) to the other element or be indirectly connected (coupled) to the other element having an intervening element therebetween. It will be understood that the terms “comprise”, “include”, and/or “have” when used herein, specify the presence of stated elements but do not preclude the presence or addition of one or more other elements.
Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
A schematic structure of the inkjet printing equipment 1 according to the related art is illustrated in
Referring to
As illustrated in
According to the related art, the substrate S is moved along the first axial direction (Y direction), and repeats forward and backward movements. During the forward or backward movement of the substrate S, the inkjet head unit 20 ejects the ink onto the substrate S while being moved along the second axial direction (X direction). Here, when the inkjet head unit 20 is not able to eject the ink to the entire area of the substrate S, an ink ejection process is performed for each of two divided areas PZ1 and PZ2 on the substrate S, so that the overall ink ejection process is performed two times.
Here, as illustrated in
However, the inkjet printing equipment 1 described with reference to
Since ink ejected by the nozzle 212-1B and ink ejected by 212-2A are deposited on the substrate S in an overlapping manner, even when ink on the substrate S is photographed for inspection of the nozzles 214, it is impossible to identify from which nozzle 214 the ink is ejected. This results in an increase in inspection time and a decrease in inspection accuracy. For example, when a deposition error is found in ink in a specific row, the use of a plurality of nozzles 214 that may have ejected the ink in the corresponding row is stopped, so that even normal nozzles 214 become unavailable.
In addition, since the inkjet head unit 20 is moved by the two gantries 30 during the movement of the substrate S, a plurality of axial movements occur, resulting in heat. This heat may cause a drive amount error.
In addition, in the case of large-area equipment, the weight of the equipment increases due to its large volume. Also, when performing inkjet printing on the substrate S for each of the printing areas PZ1 and PZ2 of the substrate S, after the process for the specific printing area PZ1 is completed, the process for the next printing area PZ2 proceeds. In this case, switching of the printing areas takes time.
Therefore, in order to solve the above problems of the related art, the present disclosure provides inkjet printing equipment 1 capable of performing an inkjet printing process on a substrate S more quickly and reducing the weight and efficiency of the equipment 1. According to the present disclosure, the head packs 210 are arranged in a line along a single axis (coaxial direction) so as not to overlap along the first axial direction (Y direction), so that the nozzle 214 corresponding to the ink ejected on the substrate S 214 can be easily identified. Hereinafter, an inkjet head unit 20 and the inkjet printing equipment 1 including the same according to the present disclosure will be described.
The inkjet printing equipment 1 according to an embodiment of the present disclosure largely includes: a stage 10 for supporting and transporting a substrate S; an inkjet head unit 20 for ejecting ink onto the substrate S; and a gantry 30 for providing a path for movement of the inkjet head unit 20. The inkjet head unit 20 includes: a head pack 210 having a plurality of ejection heads 212 for ejecting ink of the same color onto the substrate S; a head base 220 on which a plurality of head packs 210 are installed to be repeatedly coaxially arranged in color order; a head frame 230 for accommodating the head packs 210 and configured to be moved along the gantry 30.
The stage 10 provides a space in which the substrate S is placed, and may be configured such that the substrate S is moved along the first axial direction (Y direction). For example, in a state in which the substrate S is raised by blowing air from the bottom of the stage 10, grippers (not illustrated) provided on opposite sides of the stage 10 may be moved along the first axial direction (Y direction) while holding the substrate S. Alternatively, the stage 10 may be composed of a plurality of rollers to physically support the substrate S.
The inkjet head unit 20 is a mechanism for ejecting the ink onto the substrate S. A detailed configuration of the inkjet head unit 20 will be described later with reference to
The gantry 30 is provided above the stage 10 and is a structure for installing and moving the inkjet head unit 20. In the gantry 30, a path may be formed so that the head frame 230 of the inkjet head unit 20 is coupled and moved. The gantry 30 may extend along the second axial direction (X direction). According to the present disclosure, the gantry 30 may be provided as a single structure.
In addition, according to the present disclosure, an ink inspection camera 40 for inspecting the state of the ink ejected on the substrate S may be provided. In other words, an inkjet printing equipment 1 according to another embodiment of the present disclosure includes: a stage 10 for supporting a substrate S configured to be moved along the first axial direction (Y direction); an inkjet head unit 20 for ejecting ink onto the substrate S; a gantry 30 for providing a path for movement of the inkjet head unit 20; and the ink inspection camera 40 for inspecting the state of the ink ejected on the substrate S. The inkjet head unit 20 includes: a head pack 210 having a plurality of ejection heads 212 for ejecting ink of the same color onto the substrate S; a head base 220 on which a plurality of head packs 210 are installed to be repeatedly coaxially arranged in color order; a head frame 230 for accommodating the head packs 210 and configured to be moved along the gantry 30.
Referring to
According to the present disclosure, the head packs 210 provided on the head base 220 are coaxially arranged in a line without overlapping along the first axial direction (Y direction). However, within each of the head packs 210, the ejection heads 212 or nozzles 214 may be arranged in an overlapping manner according to pixel resolution. Each of the head packs 210 includes the plurality of ejection heads 212 that eject ink corresponding to pixels of the same color. Each of the ejection heads 212 may include a plurality of nozzles 214. The interval between the head packs 210, the interval between the ejection heads 212 within the head packs 210, and the interval between the nozzles 214 within the ejection heads 212 may be determined according to the area and resolution of the substrate S.
Referring to
According to an embodiment of the present disclosure, the head packs 210 may include a first head pack 210-1 having a plurality of ejection heads 212 for eject ink corresponding to a first color (e.g., red R), a second head pack 210-2 having a plurality of ejection heads 212 for ejecting ink corresponding to a second color (e.g., green G), and a third head pack 210-3 having a plurality of ejection heads 212 ejecting ink corresponding to a third color (e.g., blue B).
According to an embodiment of the present disclosure, a head pack set in which the first head pack 210-1, the second head pack 210-2, and the third head pack 210-3 are sequentially arranged may be repeatedly installed on the head base 220.
According to the present disclosure, there exists no pixel in which a plurality of head packs 210 ejects ink in an overlapping manner, and ink ejection for one pixel is performed by corresponding one head pack 210. Thus, when an ink ejection state of a specific pixel is abnormal, a nozzle 214 and a head pack 210 that have ejected ink of the corresponding pixel can be immediately identified, thereby enabling quick and simple nozzle inspection and maintenance.
In other words, due to such a reduction in time for nozzle inspection and maintenance, utilization of the nozzles 214 can be increased, and yield and lifespan can be increased. In addition, inkjet printing is performed on the entire area of the substrate S, and the substrate S does not need to be divided into a plurality of printing areas. Thus, an axial movement amount can be reduced. Also, the overall weight of the equipment 1 can be reduced.
According to an embodiment of the present disclosure, the substrate S is configured to be moved along the first axial direction (Y direction), and the plurality of head packs 210 are arranged along the second axial direction (X direction) orthogonal to the first axial direction (Y direction).
According to an embodiment of the present disclosure, the head base 220 may be configured to be moved along the second axial direction (X direction).
According to an embodiment of the present disclosure, the head packs 210 may be arranged on the head base 220 to have a length wH equal to a length wG of the substrate S in the second axial direction (X direction).
According to the embodiment of the present disclosure, the nozzles 214 of the ejection heads 212 of each of the head packs 210 may be arranged to overlap each other along the first axial direction (Y direction), and each of the head packs 210 and another head pack 210 are arranged so as to not overlap each other along the first axial direction (Y direction).
Referring to
Meanwhile, referring back to
In addition, the inkjet head unit 20 may further include an ink reservoir 250 for storing ink supplied to the head packs 210 and a pressure controller 260 for controlling ink ejection pressure. The ink reservoir 250 is located above the head packs 210. The ink reservoir 250 is configured to store ink and circulate the ink to the ejection heads 212 of the head packs 210. The pressure controller 260 controls the ink ejection pressure by adjusting the meniscus of the ejection heads 212. The pressure controller 260 is located above the ink reservoir 250. In addition, the inkjet head unit 20 may further include a temperature control mechanism 240 for controlling the temperature of ink and provided between the inkjet head unit 20 and the gantry 30. The temperature control mechanism 240 adjusts the viscosity of ink by adjusting the temperature of the ink stored in the ink reservoir 250. The temperature control mechanism 240 may be configured as a pipe through which a fluid flows at a desired temperature.
In addition, the inkjet printing equipment 1 may further include a flatness inspector (including a camera and a measurement sensor) 50 for inspecting an alignment state of the ejection heads 212. Referring to
While exemplary embodiments of the present disclosure have been described, those skilled in the art will appreciate that various modifications, additions, and substitutions are possible, without departing from the scope and spirit of the present disclosure.
The scope of the present disclosure should be defined only by the accompanying claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0105744 | Aug 2022 | KR | national |
