Inkjet printing appartus and method of inkjet printing

Abstract

An inkjet printing device includes a body that stores ink and an inkjet head connected to one side of the body to discharge the ink, the body includes an ink transfer tube that stores the ink and delivers it to the inkjet head, a filter disposed inside the ink transfer tube, and a first electrode and a second electrode disposed facing each other with the filter in between, wherein a first voltage is applied to the first electrode and a second voltage lower than the first voltage is applied to the second electrode, and the first electrode and the second electrode can form an electric field due to the voltage difference between the first voltage and the second voltage.

Description

Technology Field

[0001] The present invention relates to an inkjet printing device and an inkjet printing method using the inkjet printing device. Background Technology

[0002] Inkjet printing is a technology that creates an image in which each ink is colored by spraying ink into a predetermined area partitioned by a barrier. Recently, it has been widely used in the manufacturing process of display devices such as Organic Light Emitting Displays (OLEDs) and Liquid Crystal Displays (LCDs). When printing patterns for display devices using an inkjet printing process, devices can be produced with only a small amount of material compared to deposition processes, and costs can be significantly reduced due to the simplification of the manufacturing process.

[0003] However, if stains or partial clogging occur in the ink-spraying nozzle, the ink's straightness cannot be ensured, which may reduce the reproducibility of the ink impact location. In this case, a pattern with an accurate shape may not be printed, or defects may occur due to color mixing between inks. Additionally, productivity may decrease due to maintenance work required to remove the stains or clogging from the nozzle. The problem to be solved

[0004] One objective of the present invention is to provide an inkjet printing device.

[0005] Another objective of the present invention is to provide an inkjet printing method using an inkjet printing device.

[0006] However, the present invention is not limited by the purposes described above and may be extended in various ways without departing from the spirit and scope of the invention. means of solving the problem

[0007] To achieve one objective of the present invention as described above, an inkjet printing device according to exemplary embodiments of the present invention comprises a body for storing ink and an inkjet head connected to one side of the body for discharging the ink, wherein the body may include an ink transfer tube for storing the ink and transferring it to the inkjet head, a filter disposed inside the ink transfer tube, and a first electrode and a second electrode disposed facing each other with the filter in between. A first voltage is applied to the first electrode, and a second voltage lower than the first voltage is applied to the second electrode, and the first electrode and the second electrode may form an electric field due to the voltage difference between the first voltage and the second voltage.

[0008] In one embodiment, the ink may include needle-shaped particles.

[0009] In one embodiment, the filter includes an opening that penetrates the filter, and the needle-shaped particles may be able to pass through the opening when the electric field is formed.

[0010] In one embodiment, the filter has a mesh structure including a plurality of openings penetrating the filter, and the needle-shaped particles may be able to pass through the openings when the electric field is formed.

[0011] In one embodiment, the voltage may be a DC voltage, an AC voltage, or a square wave voltage.

[0012] In one embodiment, a voltage supply unit may be further included for applying the first voltage to the first electrode and applying the second voltage to the second electrode.

[0013] In one embodiment, the first electrode may be spaced apart from the filter in a direction opposite to the direction in which the ink moves, and the second electrode may be spaced apart from the filter in the direction in which the ink moves.

[0014] To achieve one objective of the present invention as described above, an inkjet printing device according to exemplary embodiments of the present invention comprises a body for storing ink and an inkjet head connected to one side of the body for discharging the ink, wherein the body may include an ink transfer tube for storing the ink and transferring it to the inkjet head, a metal filter disposed inside the ink transfer tube, and an electrode disposed opposite to the metal filter and spaced apart from the metal filter in a direction opposite to the direction in which the ink moves. A first voltage is applied to the electrode, and a second voltage lower than the first voltage is applied to the metal filter, and the electrode and the metal filter may form an electric field due to the voltage difference between the first voltage and the second voltage.

[0015] In one embodiment, the ink may include needle-shaped particles.

[0016] In one embodiment, the metal filter includes an opening that penetrates the metal filter, and the needle-shaped particles may be able to pass through the opening when the electric field is formed.

[0017] In one embodiment, the metal filter has a mesh structure including a plurality of openings penetrating the metal filter, and the needle-shaped particles may be able to pass through the openings when the electric field is formed.

[0018] In one embodiment, the voltage may be a DC voltage, an AC voltage, or a square wave voltage.

[0019] In one embodiment, a voltage supply unit may be further included for applying the first voltage to the electrode and applying the second voltage to the metal filter.

[0020] To achieve another objective of the present invention described above, an inkjet printing method according to exemplary embodiments of the present invention may include the steps of injecting ink into an ink transfer tube included in an inkjet printing device, applying voltage to a first electrode and a second electrode disposed with a filter disposed between them in the ink transfer tube, and discharging the ink that has passed through the filter through an inkjet head.

[0021] In one embodiment, the step of applying the voltage includes the step of applying a first voltage to the first electrode and the step of applying a second voltage lower than the first voltage to the second electrode, and an electric field may be formed between the first electrode and the second electrode by the voltage difference between the first voltage and the second voltage.

[0022] In one embodiment, the voltage may be a DC voltage, an AC voltage, or a square wave voltage.

[0023] In one embodiment, the ink may include needle-shaped particles.

[0024] In one embodiment, the first electrode is spaced apart from the filter in a direction opposite to the direction in which the ink moves, and

[0025] The second electrode may be positioned spaced apart from the filter in the direction in which the ink moves. Effects of the invention

[0026] An inkjet printing device according to embodiments of the present invention includes a body for storing ink and an inkjet head connected to one side of the body for discharging the ink, and the body may include an ink transfer tube for storing the ink and transferring it to the inkjet head, a filter disposed inside the ink transfer tube, and a first electrode and a second electrode disposed facing each other with the filter in between. A first voltage is applied to the first electrode, and a second voltage lower than the first voltage is applied to the second electrode, and the first electrode and the second electrode may form an electric field due to the voltage difference between the first voltage and the second voltage.

[0027] Accordingly, when the electric field is formed, needle-shaped particles contained in the ink can be aligned in one direction, pass through the filter, and then be ejected through the inkjet head. Additionally, the filter can filter out foreign substances contained in the ink so that they do not pass through the filter.

[0028] However, the effects of the present invention are not limited to the effects described above, and may be extended in various ways without departing from the spirit and scope of the present invention. Brief explanation of the drawing

[0029] FIG. 1 is a block diagram showing a display device according to embodiments of the present invention. FIG. 2 is a drawing showing an inkjet printing device according to embodiments of the present invention. FIG. 3 is a drawing showing an embodiment of the inkjet printing device of FIG. 2. FIGS. 4 and FIGS. 5 are drawings showing the formation of an electric field in the inkjet printing device of FIG. 2. Figure 6 is a diagram showing the types of voltages applied to the inkjet printing device of Figure 2. FIGS. 7 to 9 are drawings showing embodiments in which ink flows through an ink transfer tube included in the inkjet printing device of FIG. 2. FIGS. 10 and FIGS. 11 are drawings showing embodiments of a filter included in the inkjet printing device of FIG. 2. FIGS. 12 and FIGS. 13 are drawings showing an inkjet printing device according to embodiments of the present invention. FIG. 14 is a diagram showing the formation of an electric field in the inkjet printing device of FIG. 12. FIGS. 15 and FIGS. 16 are drawings showing embodiments of a metal filter included in the inkjet printing device of FIG. 12. Specific details for implementing the invention

[0030] Hereinafter, embodiments of the present invention will be described in more detail with reference to the attached drawings. Identical or similar reference numerals are used for identical components in the attached drawings.

[0031] FIG. 1 is a block diagram showing a display device according to embodiments of the present invention.

[0032] Referring to FIG. 1, the display device may include a display panel (DP), a data driver (DDV), a gate driver (GDV), and a timing control unit (CON).

[0033] The above display device can display an image through the display panel (DP). To this end, the display panel (DP) may include a plurality of pixels and light-emitting elements connected to the pixels. In embodiments, the display panel (DP) may be composed of a single panel. Or, in embodiments, the display panel (DP) may be composed of a plurality of panels.

[0034] The timing control unit (CON) can generate a gate control signal (GCTRL), a data control signal (DCTRL), and output image data (ODAT) based on a control signal (CTRL) and input image data (IDAT) provided from the outside. For example, the control signal (CTRL) may include a vertical synchronization signal, a horizontal synchronization signal, an input data enable signal, a master clock signal, etc. For example, the input image data (IDAT) may be RGB data including red image data, green image data, and blue image data. Alternatively, the input image data (IDAT) may include magenta image data, cyan image data, and yellow image data.

[0035] The gate driver (GDV) can generate gate signals based on the gate control signal (GCTRL) provided by the timing control unit (CON). For example, the gate control signal (GCTRL) may include a vertical start signal, a clock signal, etc. In embodiments, the gate driver (GDV) may be manufactured as a separate panel and connected to the display panel (DP). The gate driver (GDV) is electrically connected to the display panel (DP) and can sequentially output the gate signals. Each of the pixels may receive a data voltage according to the control of each of the gate signals.

[0036] The data driver (DDV) can generate the data voltage based on the data control signal (DCTRL) and the output image data (ODAT) provided by the timing control unit (CON). For example, the data control signal (DCTRL) may include an output data enable signal, a horizontal start signal, a load signal, etc. In embodiments, the data driver (DDV) may be manufactured as a separate panel and electrically connected to the display panel (DP). The data driver (DDV) is electrically connected to the display panel (DP) and can generate a plurality of data voltages. Each of the pixels can transmit a signal for brightness corresponding to each of the data voltages to the light-emitting elements.

[0037] An inkjet printing device may be used in the process of manufacturing the above display device. The inkjet printing device may be used when manufacturing various components included in the display panel (DP). For example, a light-emitting layer, electrodes, etc., may be formed using the inkjet printing device.

[0038] FIG. 2 is a drawing showing an inkjet printing device according to embodiments of the present invention.

[0039] Referring to FIG. 2, an inkjet printing device (IPD) may include a body (BP) and an inkjet head (INO). Ink (INK) may be stored in the body (BP). The ink (INK) may be ejected through the inkjet head (INO). In embodiments, the inkjet head (INO) may be at least one. Although FIG. 2 shows three inkjet heads (INO), this is exemplary and is not limited thereto.

[0040] The inkjet head (INO) can eject the ink (INK). The ink (INK) may include organic materials, metal particles, etc. The ink (INK) may be for forming a light-emitting layer or for forming an electrode layer.

[0041] To form the above layers, a display panel (DP) may be placed on a stage (ST). In the embodiments, the display panel (DP) may be formed up to an anode electrode. In this case, the inkjet printing device (IPD) may discharge a light-emitting material to form a light-emitting layer on the display panel (DP). Or, in the embodiments, the inkjet printing device (IPD) may discharge a material to form an electrode layer on the display panel (DP).

[0042] FIG. 3 is a drawing showing an embodiment of the inkjet printing device of FIG. 2.

[0043] Referring to FIGS. 2 and 3, the inkjet printing device (IPD) may further include an ink inlet (INI). The ink (INK) may be introduced through the ink inlet (INI). Subsequently, the inkjet printing device (IPD) may discharge the ink (INK) through the inkjet head (INO).

[0044] The body (BP) may include an ink transfer tube (INS) that stores the ink (INK) and transfers the ink (INK) to the inkjet head (INO). A filter (FI1) may be disposed inside the ink transfer tube. In the embodiments, the filter (FI) may include an opening (OP) that penetrates the filter (FI). The inkjet printing device (IPD) may allow only desired particles, materials, etc. to flow to the inkjet head (INO) through the opening (OP).

[0045] The above body (BP) may include a first electrode (ED1) and a second electrode (ED2). The first electrode (ED1) and the second electrode (ED) may be positioned with the filter (FI1) in between. The first electrode (ED1) may be positioned spaced apart from the filter (FI1) in a direction opposite to the direction in which the ink (INK) flows toward the filter (FI1). The second electrode (ED2) may be positioned spaced apart from the filter (FI1) in the direction in which the ink (INK) flows through the filter (FI1). Different voltages may be applied to the first electrode (ED1) and the second electrode (ED2), respectively. The first electrode (ED1) and the second electrode (ED2) may form an electric field between the first electrode (ED1) and the second electrode (ED2). This will be explained with reference to FIGS. 4 to 6, which will be described later.

[0046] In FIG. 3, the first electrode (ED1) and the second electrode (ED2) are shown as being placed outside the ink delivery tube (INS), but this is exemplary and is not limited thereto. For example, the first electrode (ED1) and the second electrode (ED2) may be placed inside the ink delivery tube (INS).

[0047] FIGS. 4 and FIGS. 5 are drawings showing the formation of an electric field in the inkjet printing device of FIG. 2, and FIG. 6 is a drawing showing the types of voltages applied to the inkjet printing device of FIG. 2.

[0048] Referring to FIGS. 4 to 6, the inkjet printing device may further include a voltage supply unit (PS). The first electrode (ED1) and the second electrode (ED2) may be connected to the voltage supply unit (PS). The voltage supply unit (PS) may supply a first voltage to the first electrode (ED1) and a second voltage to the second electrode (ED2). The first voltage may be a higher voltage than the second voltage. Through this, an electric field based on the voltage difference between the first voltage and the second voltage may be formed. That is, an electric field may be formed from the first electrode (ED1) toward the second electrode (ED2).

[0049] For example, the first voltage may be a positive voltage and the second voltage may be a negative voltage. Although FIG. 5 is illustrated as applying a positive voltage to the first electrode (ED1) and a negative voltage to the second electrode (ED2), this is exemplary and is not limited thereto. FIG. 5 indicates that the voltage applied to the first electrode (ED1) is relatively larger than the voltage applied to the second electrode (ED2). For example, the first voltage may be a positive voltage and the second voltage may be a positive voltage relatively smaller than the first voltage.

[0050] In the embodiments, the types of voltages applied to the first electrode (ED1) and the second electrode (ED2) may vary. For example, a DC voltage as shown in FIG. 6 (a) may be applied to the first electrode (ED1) and the second electrode (ED2). Alternatively, a square wave voltage as shown in FIG. 6 (b) may be applied to the first electrode (ED1) and the second electrode (ED2). Alternatively, an AC voltage as shown in FIG. 6 (c) may be applied to the first electrode (ED1) and the second electrode (ED2).

[0051] FIGS. 7 to 9 are drawings showing embodiments in which ink flows through an ink transfer tube included in the inkjet printing device of FIG. 2.

[0052] Referring to FIGS. 7 through 9, the ink may comprise a plurality of particles (PT). The particles (PT) may comprise organic materials, metal particles, etc. For example, the organic material may comprise a red organic light-emitting material, a blue organic light-emitting material, a red organic light-emitting material, etc. Additionally, the particles (PT) may comprise nano-sized LED materials. In this case, the nano-sized LED materials may comprise rods in the form of rods (e.g., needles) extending in one direction. For example, the rods may be nano-sized rods containing GaN. The organic light-emitting materials may emit a unique light (e.g., red, blue, green, etc.) when voltage is applied. For example, the particles (PT) may comprise carbon nanotubes, microchips, etc.

[0053] The particles (PT) may have a length in the longitudinal direction and a width in the thickness direction. The length may be greater than the width. The particles (PT) may have polarity. Accordingly, when an electric field is formed by the first electrode (ED1) and the second electrode (ED2), the particles (PT) may be aligned in the longitudinal direction to the second direction (DR2) by the electric field. However, the particles (PT) may not have polarity, but even in this case, the particles (PT) may be aligned by the electric field when the electric field is formed.

[0054] For example, the width of the opening (OP) penetrating the filter (FI1) may be greater than the width of the particles (PT). Also, the width of the opening (OP) may be smaller than the length of the particles (PT). Thus, the particles (PT) can pass through the filter (FI1) when an electric field is formed by the first electrode (ED1) and the second electrode (ED2). As shown in FIG. 9, the inkjet printing device (IPD) can filter out foreign substances (TP) that do not have a needle shape.

[0055] FIGS. 10 and FIGS. 11 are drawings showing embodiments of a filter included in the inkjet printing device of FIG. 2.

[0056] Referring to FIG. 10, the filter (FI1) may be formed from a plastic material. For example, the filter (FI1) may be formed from resin, Teflon, etc. The filter (FI1) may include an opening (OP) that penetrates the filter (FI1). Although FIG. 10 shows one opening (OP), the number of openings (OP) is not limited thereto. For example, as shown in FIG. 11, the filter (FI1) may include a plurality of openings (OP). In this case, the filter (FI1) may have a mesh shape. In this case, the particles (PT) can pass through the openings (OP).

[0057] FIGS. 12 and 13 are drawings showing an inkjet printing device according to embodiments of the present invention, and FIG. 14 is a drawing showing an electric field being formed in the inkjet printing device of FIG. 12.

[0058] Referring to FIGS. 12 and 13, an inkjet printing device (IPD) may include an ink inlet (INI), a body (BP), and an inkjet head (INO). The body (BP) may include an ink transfer tube (INS), an electrode (ED), and a metal filter (FI2).

[0059] Ink can be introduced into the body (BP) through the ink inlet (INI). The ink is stored in the ink transfer tube (INS) and can flow to the inkjet head (INO) through the ink transfer tube (INS).

[0060] The metal filter (FI2) may be placed inside the ink transfer tube (INS). The metal filter (FI2) can prevent foreign substances (TP), etc. contained in the ink from flowing to the inkjet head (INO).

[0061] The electrode (ED) may be positioned opposite to the metal filter (FI2). The electrode (ED) may be positioned spaced apart from the metal filter in a direction opposite to the direction of ink flow.

[0062] A first voltage may be applied to the electrode (ED), and a second voltage may be applied to the metal filter (FI2). The first voltage may be a higher voltage than the second voltage. As shown in FIG. 14, an electric field may be formed between the electrode (ED) and the metal filter (FI2) by the difference between the first voltage and the second voltage.

[0063] FIGS. 15 and FIGS. 16 are drawings showing embodiments of a metal filter included in the inkjet printing device of FIG. 12.

[0064] Referring to FIG. 15, the metal filter (FI2) may be formed from a plastic material. For example, the metal filter (FI2) may be formed from the same material as the aforementioned electrodes (ED, ED1, ED2). That is, the metal filter (FI2) may be formed from a conductive material to allow voltage to be applied. The metal filter (FI2) may include an opening (OP) that penetrates the metal filter (FI2). Although FIG. 15 shows one opening (OP), the number of openings (OP) is not limited thereto. For example, as shown in FIG. 16, the metal filter (FI2) may include a plurality of openings (OP). In this case, the metal filter (FI2) may have a mesh shape. In this case, the particles (PT) can pass through the openings (OP).

[0065] Although the foregoing description refers to exemplary embodiments of the present invention, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the invention as set forth in the following claims. Industrial applicability

[0066] The present invention can be applied to an inkjet printing device and an inkjet printing method using the inkjet printing device. For example, the present invention can be applied when manufacturing display devices for vehicles, ships and aircraft, portable communication devices, display devices for exhibition or information transmission, medical display devices, etc. Explanation of the symbols

[0067] DDV: Data driver GDV: Gate driver DP: Display Panel ST: Stage IPD: Inkjet printing device BP: Body INO: Inkjet head INK: Ink INI: Ink input port ED: Electrode ED1: First electrode ED2: Second electrode FI1: Filter FI2: Metal filter OP: Opening PS: Voltage supply PT: Particle

Claims

Claim 1 An inkjet printing device comprising: a body for storing ink; and an inkjet head connected to one side of the body for discharging the ink, wherein the body comprises: an ink transfer tube for storing the ink and transferring it to the inkjet head; a filter disposed inside the ink transfer tube; and a first electrode and a second electrode disposed facing each other with the filter in between, wherein a first voltage is applied to the first electrode and a second voltage lower than the first voltage is applied to the second electrode, and the first electrode and the second electrode form an electric field due to the voltage difference between the first voltage and the second voltage, wherein the ink comprises needle-shaped particles, and the filter comprises an opening penetrating the filter, and wherein the needle-shaped particles are capable of passing through the opening when the electric field is formed. Claim 2 delete Claim 3 delete Claim 4 An inkjet printing device comprising: a body for storing ink; and an inkjet head connected to one side of the body for discharging the ink, wherein the body comprises: an ink transfer tube for storing the ink and transferring it to the inkjet head; a filter disposed inside the ink transfer tube; and a first electrode and a second electrode disposed facing each other with the filter in between, wherein a first voltage is applied to the first electrode and a second voltage lower than the first voltage is applied to the second electrode, and the first electrode and the second electrode form an electric field due to the voltage difference between the first voltage and the second voltage, wherein the ink comprises needle-shaped particles, and the filter has a mesh structure comprising a plurality of openings penetrating the filter, and wherein the needle-shaped particles are capable of passing through the openings when the electric field is formed. Claim 5 An inkjet printing device according to claim 1, characterized in that the voltage is a direct current voltage, an alternating current voltage, or a square wave voltage. Claim 6 An inkjet printing device according to claim 1, further comprising a voltage supply unit that applies the first voltage to the first electrode and applies the second voltage to the second electrode. Claim 7 An inkjet printing device according to claim 1, characterized in that the first electrode is spaced apart from the filter in a direction opposite to the direction in which the ink moves, and the second electrode is spaced apart from the filter in the direction in which the ink moves. Claim 8 An inkjet printing device comprising: a body for storing ink; and an inkjet head connected to one side of the body for discharging the ink, wherein the body comprises: an ink transfer tube for storing the ink and transferring it to the inkjet head; a metal filter disposed inside the ink transfer tube; and an electrode disposed opposite to the metal filter and spaced apart from the metal filter in a direction opposite to the direction in which the ink moves, wherein a first voltage is applied to the electrode and a second voltage lower than the first voltage is applied to the metal filter, and the electrode and the metal filter form an electric field due to the voltage difference between the first voltage and the second voltage, wherein the ink comprises needle-shaped particles, and the metal filter comprises an opening penetrating the metal filter, and wherein the needle-shaped particles are capable of passing through the opening when the electric field is formed. Claim 9 delete Claim 10 delete Claim 11 An inkjet printing device comprising: a body for storing ink; and an inkjet head connected to one side of the body for discharging the ink, wherein the body comprises: an ink transfer tube for storing the ink and transferring it to the inkjet head; a metal filter disposed inside the ink transfer tube; and an electrode disposed opposite to the metal filter and spaced apart from the metal filter in a direction opposite to the direction in which the ink moves, wherein a first voltage is applied to the electrode and a second voltage lower than the first voltage is applied to the metal filter, and the electrode and the metal filter form an electric field based on the voltage difference between the first voltage and the second voltage, wherein the ink comprises needle-shaped particles, and the metal filter has a mesh structure comprising a plurality of openings penetrating the metal filter, and wherein the needle-shaped particles are capable of passing through the openings when the electric field is formed. Claim 12 An inkjet printing device according to claim 8, characterized in that the voltage is a direct current voltage, an alternating current voltage, or a square wave voltage. Claim 13 An inkjet printing device according to claim 8, further comprising a voltage supply unit that applies the first voltage to the electrode and applies the second voltage to the metal filter. Claim 14 An inkjet printing method comprising: a step of injecting ink into an ink transfer tube included in an inkjet printing device; a step of applying voltage to a first electrode and a second electrode disposed with a filter disposed between them in the ink transfer tube; and a step of discharging the ink that has passed through the filter through an inkjet head, wherein the step of applying voltage includes a step of applying a first voltage to the first electrode; and a step of applying a second voltage lower than the first voltage to the second electrode, wherein an electric field is formed between the first electrode and the second electrode by the voltage difference between the first voltage and the second voltage, the ink comprises needle-shaped particles, the filter comprises an opening penetrating the filter, and the needle-shaped particles are capable of passing through the opening when the electric field is formed. Claim 15 delete Claim 16 An inkjet printing method according to claim 14, characterized in that the voltage is a direct current voltage, an alternating current voltage, or a square wave voltage. Claim 17 delete Claim 18 An inkjet printing method according to claim 14, wherein the first electrode is spaced apart from the filter in a direction opposite to the direction in which the ink moves, and the second electrode is spaced apart from the filter in the direction in which the ink moves.

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