Electronic device, inkjet printing device, and method for manufacturing a display panel using an inkjet printing device

Abstract

To provide an inkjet printing apparatus that can reduce the defect rate of the organic light-emitting layer. [Solution] An inkjet printing apparatus according to one embodiment of the present invention may include: a first stage; a second stage disposed on the first stage and on which a substrate is disposed that includes a heater and a print area superimposed on the heater in a plan view; a head unit disposed on the substrate and including a plurality of print heads and an ink supply device that supplies ink containing a substance that emits excitation light in response to electromagnetic waves to the print heads; and a camera unit disposed on the side of the head unit and measuring the excitation light generated from the ink by irradiating the ink with electromagnetic waves.

Description

Technical Field

[0001] The present invention relates to an electronic device, an inkjet printing device, and a method for manufacturing a display panel using the same.

Background Art

[0002] Generally, an organic light emitting diode display (OLED) that has excellent luminance characteristics and viewing angle characteristics and does not require a separate light source unit unlike a liquid crystal display device has attracted attention as a next-generation flat panel display device. The organic light emitting diode display does not require a separate light source and can be manufactured to be lightweight and thin. Further, the organic light emitting diode display has characteristics such as low power consumption, high luminance, and high response speed.

[0003] The organic light emitting diode display includes a plurality of light emitting elements each including an anode, an organic light emitting layer, and a cathode. Holes and electrons are respectively injected from the anode and the cathode into the organic light emitting layer to form excitons, and the light emitting element emits light while the excitons transition to the ground state.

[0004] When manufacturing the light emitting element, the organic light emitting layer is manufactured by an inkjet printing device. An organic substance (or ink) for forming the organic light emitting layer can be discharged from the inkjet printing device onto a substrate to form the organic light emitting layer.

[0005] When manufacturing the organic light emitting diode display, a high-resolution precise patterning process is required. As the pixel size of the organic light emitting diode display having high resolution becomes smaller, the inkjet printing device should discharge a smaller amount of ink. If the amount of ink discharged from the inkjet printing device is not finely controlled, a defective organic light emitting layer will be manufactured. Development of an inkjet printing device capable of finely controlling the amount of inkjet is required.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The object of the present invention is to provide an inkjet printing apparatus that can reduce the defect rate of the organic light-emitting layer. [Means for solving the problem]

[0007] An inkjet printing apparatus according to one embodiment of the present invention may include: a first stage; a second stage disposed on the first stage and on which a substrate is disposed, which includes a heater and a print area that overlaps with the heater in a plan view; a head unit disposed on the substrate and including a plurality of print heads and an ink supply device that supplies ink containing a substance that emits excitation light in response to electromagnetic waves to the print heads; and a camera unit disposed on the side of the head unit and measuring the excitation light generated from the ink by irradiating the ink with electromagnetic waves.

[0008] The head unit further includes a plurality of nozzles, each of which may be positioned on the underside of the print head.

[0009] The nozzles include a first nozzle group defined as a plurality of first nozzles arranged in a first direction, a second nozzle group defined as a plurality of second nozzles arranged in the first direction, and a third nozzle group defined as a plurality of third nozzles arranged in the first direction, wherein the first nozzle group, the second nozzle group, and the third nozzle group may be arranged in a second direction intersecting the first direction.

[0010] The first nozzle and the third nozzle are arranged in the same corresponding columns in the second direction, and the second nozzle may be arranged in a column between the columns in which the first nozzle is located.

[0011] The nozzle provides the ink to the print area of ​​the substrate, thereby forming a first ink pattern.

[0012] The first ink pattern may have a ring shape in a plan view.

[0013] The nozzle can deliver the ink to an area of ​​the substrate separated from the printed area, thereby forming a second ink pattern.

[0014] Adsorption pores may be defined in the second stage.

[0015] The camera unit may further include an electromagnetic wave irradiation unit.

[0016] Each of the print heads may further include a pressure element.

[0017] The inkjet printing apparatus may further include a frame connecting the first stage and the head unit.

[0018] A method for manufacturing a display panel according to one embodiment of the present invention may include the steps of: preparing a first stage; arranging a second stage, which includes a heater, on the first stage; arranging a substrate, which includes a print area that overlaps with the heat in a plan view, on the second stage; arranging a head unit on the substrate, which includes a plurality of print heads, an ink supply device that supplies ink containing a substance that emits excitation light in response to electromagnetic waves to the print heads, and a plurality of nozzles arranged on the lower surface of each of the print heads; arranging a camera unit on the side of the head unit to measure the excitation light generated from the ink by irradiating the ink with electromagnetic waves; providing the ink to the print area of ​​the substrate by the nozzles to form a first ink pattern; measuring the excitation light of the first ink pattern with the camera unit; discharging the ink from the nozzles to an area of ​​the substrate separated from the print area to form a second ink pattern; curing the second ink pattern to form a light-emitting layer; and manufacturing a display panel by curing the second ink pattern to form a light-emitting layer.

[0019] The camera unit further includes an electromagnetic wave irradiation unit, and the step of the camera unit measuring the excitation light of the first ink pattern may include the step of the electromagnetic wave irradiation unit irradiating the first ink pattern with electromagnetic waves to measure the central position and light intensity of the excitation light.

[0020] After the camera unit measures the excitation light of the first ink pattern, the method for manufacturing the display panel may further include the step of the ink supply device adjusting the ink discharge time.

[0021] Each print head further includes a pressure element, and after the camera unit measures the excitation light of the first ink pattern, the method for manufacturing the display panel may further include the step of the pressure element adjusting the amount of ink discharged by the nozzle.

[0022] After the camera unit measures the excitation light of the first ink pattern, the method for manufacturing the display panel may further include the step of drying the first ink pattern with the heater.

[0023] An electronic device according to one embodiment of the present invention includes a display device for displaying images and a processor for processing and providing image signals to the display device, wherein the display device includes the steps of: preparing a first stage; arranging a second stage, which includes a heater, on the first stage; arranging a substrate on the second stage, which includes a print area that overlaps with the heat in a plan view; arranging a head unit on the substrate, which includes a plurality of print heads, an ink supply device for supplying ink containing a substance that emits excitation light in response to electromagnetic waves to the print heads, and a plurality of nozzles arranged on the lower surface of each of the print heads, The present invention may include the steps of: positioning a camera unit on the side of the head unit to measure the excitation light generated from the ink by irradiating the ink with electromagnetic waves; providing the ink to the print area of ​​the substrate by the nozzle to form a first ink pattern; the camera unit measuring the excitation light of the first ink pattern; discharging the ink from the nozzle to an area of ​​the substrate separated from the print area to form a second ink pattern; curing the second ink pattern to form a light-emitting layer; and a display panel manufactured by curing the second ink pattern to form a light-emitting layer. [Effects of the Invention]

[0024] As described above, the first ink pattern may have a ring shape in plan view. The fluidity of the ring-shaped first ink pattern may be reduced as the solvent evaporates and it becomes a liquid. Therefore, the phenomenon of the first ink pattern moving in the print area may be reduced or eliminated. In addition, noise formed by the reflection or scattering of electromagnetic waves emitted from the camera unit by the solvent in the ink may be reduced or eliminated.

[0025] Since the first ink pattern has a ring shape, the excitation light of the first ink pattern may not be generated at the center by electromagnetic waves. Therefore, the center position of the first ink pattern can be accurately measured, and the landing position of the ink before drying can be accurately measured. Also, the emission amount of the excitation light of the first ink pattern can be measured, and the volume of the ink discharged from the nozzle before drying can be measured.

Brief Description of Drawings

[0026] FIG. 1 is a block diagram of an electronic device according to an embodiment of the present invention. FIG. 2 is a schematic diagram of an electronic device according to an embodiment of the present invention. FIG. 3 is a diagram showing a method of forming an organic light-emitting layer using an inkjet printing device. FIG. 4 is a diagram exemplarily showing a cross section of any one pixel shown in FIG. 3. FIG. 5a is a perspective view of an inkjet printing device according to an embodiment of the present invention. FIG. 5b is a cross-sectional view showing a portion cut along I-I' of FIG. 5a. FIG. 6 is a schematic perspective view showing a head unit according to an embodiment of the present invention. FIG. 7 is a plan view of an inkjet printing device according to an embodiment of the present invention. FIGS. 8 to 10 are diagrams showing a print area of a substrate according to an embodiment of the present invention. FIGS. 11a to 11d are schematic cross-sectional views showing a method of manufacturing a display panel according to an embodiment of the present invention. FIGS. 11e and 11f are schematic perspective views showing a method of manufacturing a display panel according to an embodiment of the present invention.

Mode for Carrying Out the Invention

[0027] In this specification, when a component (or region, layer, part, etc.) is referred to as being "above", "connected to", or "coupled to" another component, it means that it can be directly disposed, connected, or coupled above the other component, or a third component can be disposed between them.

[0028] The same drawing symbol refers to the same component. Furthermore, in drawings, the thickness, proportions, and dimensions of components are exaggerated for the sake of effective explanation of the technical content. "and / or" includes all combinations of one or more components defined by the relevant component.

[0029] Terms such as "first," "second," etc., are used to describe a variety of components, but the components are not limited to those terms. The terms are used solely for the purpose of distinguishing one component, part, region, layer, or part from other components, parts, regions, layers, or parts. For example, without departing from the scope of the present invention, a first component, first part, first region, first layer, or first part may be named a second component, second part, second region, second layer, or second part, and similarly, a second component, second part, second region, second layer, or second part may also be named a first component, first part, first region, first layer, or first part. A singular expression includes plural expressions unless the context clearly indicates otherwise.

[0030] Furthermore, terms such as "down," "on the lower side," "up," and "on the upper side" are used to describe the relationships between the components shown in the drawing. These terms are relative concepts and are described in relation to the direction shown in the drawing.

[0031] Terms such as "includes" or "has" indicate the presence of features, figures, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood not to pre-exist to exclude the presence or possibility of adding one or more other features, figures, steps, actions, components, parts, or combinations thereof.

[0032] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as those generally understood by those skilled in the art in the field to which the present invention pertains. Furthermore, terms such as those defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an overly idealistic or formal sense unless expressly defined herein.

[0033] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0034] Figure 1 is a block diagram of an electronic device according to one embodiment of the present invention.

[0035] Referring to Figure 1, an electronic device 10 according to one embodiment may include a display module 11, a processor 12, a memory 13, and a power supply module 14.

[0036] The processor 12 may include at least one of the following: a central processing unit (CPU), an application processor (AP), a graphics processing unit (GPU), a communication processor (CP), an image signal processor (ISP), and a controller.

[0037] Memory 13 can store data information necessary for the operation of the processor 12 and the display module 11. When the processor 12 executes an application stored in memory 13, video data signals and / or input control signals are transmitted to the display module 11, and the display module 11 can process the provided signals and output video information via the display screen.

[0038] The power module 14 may include a power supply module such as a power adapter or a battery device, and a power conversion module that converts the power supplied by the power supply module to generate the power necessary for the operation of the electronic device 10.

[0039] At least one of the components of the electronic device 10 described above may be included in the display device according to the embodiment described above. Furthermore, some of the individual modules functionally contained within a single module may be included in the display device, while others may be provided separately from the display device. For example, the display device may include a display module 11, while the processor 12, memory 13, and power supply module 14 may be provided in the form of other devices within the electronic device 10 rather than in the display device itself.

[0040] Figure 2 is a schematic diagram of an electronic device according to one embodiment of the present invention.

[0041] Referring to Figure 2, the various electronic devices to which the display device according to the embodiment is applied may include not only image display electronic devices such as smartphones 10_1a, tablet PCs 10_1b, laptops 10_1c, televisions 10_1d, and desk monitors 10_1e, but also wearable electronic devices including display modules such as smart glasses 10_2a, head-mounted displays 10_2b, and smartwatches 10_2c, and vehicle electronic devices 10_3 including display modules such as CIDs (Center Information Displays) and rearview mirror displays located on the instrument panel, center fascia, and dashboard of an automobile.

[0042] The electronic device may include a display device that displays images and a processor that processes video signals and provides them to the display device. The display device may include a display panel manufactured by a display panel manufacturing method described later.

[0043] Figure 3 shows a method for forming an organic light-emitting layer using an inkjet printing device. Figure 4 is an illustrative diagram showing a cross-section of one of the pixels shown in Figure 3.

[0044] For the sake of explanation, Figure 3 shows an illustrative cross-section of the nozzle NZ portion where three nozzle holes NH are defined.

[0045] Referring to Figures 3 and 4, an inkjet printing apparatus IPA (see Figure 5a) may be used to form the light-emitting layer EML (see Figure 4). A pixel PX may include a transistor TR and a light-emitting element OLED connected to the transistor TR. Although one pixel PX is shown exemplarily, substantially multiple pixels PX may be arranged on the base layer BS.

[0046] A light-emitting OLED may include a first electrode AE, a second electrode CE, a hole control layer HCL, an electron control layer ECL, and a light-emitting layer EML. The first electrode AE ​​may be the anode electrode, and the second electrode CE may be the cathode electrode.

[0047] The transistor TR and the light-emitting element OLED may be placed on the base layer BS. The planar region of the base layer BS may be divided into a light-emitting area PA and a non-light-emitting area NPA surrounding the light-emitting area PA. The light-emitting element OLED may be placed on top of the light-emitting area PA.

[0048] A buffer layer BFL is placed on top of the base layer BS, and the buffer layer BFL may be an inorganic layer.

[0049] Semiconductor patterns S, A, and D may be arranged on a buffer layer BFL. Semiconductor patterns S, A, and D may contain polysilicon, but are not limited to this; semiconductor patterns S, A, and D may also contain amorphous silicon or metal oxides.

[0050] Semiconductor patterns S, A, and D can be doped with N-type or P-type dopants. The semiconductor patterns may include high-doping and low-doping regions. The conductivity of the high-doping regions is greater than that of the low-doping regions, and they can effectively function as the source and drain electrodes of a transistor TR. The low-doping regions can effectively correspond to the active (or channel) region of the transistor.

[0051] The source S, active A, and drain D of the transistor TR may consist of semiconductor patterns S, A, and D. A first insulating layer INS1 may be placed on the semiconductor patterns S, A, and D. The gate electrode G of the transistor TR may be placed on the first insulating layer INS1. A second insulating layer INS2 may be placed on the gate electrode G. A third insulating layer INS3 may be placed on the second insulating layer INS2.

[0052] A connecting electrode CNE can be positioned between a transistor TR and a light-emitting element OLED to connect the transistor TR and the light-emitting element OLED. The connecting electrode CNE may include a first connecting electrode CNE1 and a second connecting electrode CNE2.

[0053] The first connecting electrode CNE1 is placed on the third insulating layer INS3 and can be connected to the drain D via the first contact hole CH1 defined in the first to second insulating layers INS1 to INS3. The fourth insulating layer INS4 can be placed on the CNE1 of the first connecting electrode. The fifth insulating layer INS5 can be placed on the fourth insulating layer INS4.

[0054] The second connecting electrode CNE2 may be placed on the fifth insulating layer INS5. The second connecting electrode CNE2 may be connected to the first connecting electrode CNE1 via a second contact hole CH2 defined in the fifth insulating layer INS5. The sixth insulating layer INS6 may be placed on the second connecting electrode CNE2. The first insulating layer INS1 to the sixth insulating layer INS6 may be inorganic or organic layers.

[0055] A first electrode AE ​​may be placed on a sixth insulating layer INS6. The first electrode AE ​​may be connected to a second connecting electrode CNE2 via a third contact hole CH3 defined in the sixth insulating layer INS6. A pixel definition film PDL may be placed on the first electrode AE ​​and the sixth insulating layer INS6 to expose a predetermined portion of the first electrode AE. An opening PX_OP may be defined in the pixel definition film PDL to expose a predetermined portion of the first electrode AE.

[0056] The hole control layer (HCL) may be placed on the first electrode (AE) and the pixel definition layer (PDL). The hole control layer (HCL) may be placed in common on the light-emitting portion (PA) and the non-light-emitting portion (NPA). The hole control layer (HCL) may include a hole transport layer and a hole injection layer.

[0057] The emissive layer (EML) may be placed on top of the hole control layer (HCL). The emissive layer (EML) may be placed in the region corresponding to the aperture (PX_OP). The emissive layer (EML) may contain organic and / or inorganic materials. The emissive layer (EML) may produce one of the following light colors: red, green, and blue.

[0058] The electron control layer (ECL) may be located on top of the light-emitting layer (EML) and the hole control layer (HCL). The hole control layer (ECL) may be located in common in the light-emitting section (PA) and the non-light-emitting section (NPA). The electron control layer (ECL) may include an electron transport layer and an electron injection layer.

[0059] The second electrode CE may be located on the electronic control layer ECL. The second electrode CE may be located in common with the pixel PX.

[0060] A thin-film encapsulation layer (TFE) may be placed on top of a light-emitting element (OLED). The thin-film encapsulation layer (TFE) may be placed on top of a second electrode (CE) to cover a pixel (PX). The thin-film encapsulation layer (TFE) may include at least two inorganic layers and an organic layer placed between the inorganic layers. The inorganic layers may protect the pixel (PX) from moisture / oxygen. The organic layer may protect the pixel (PX) from foreign matter such as dust particles.

[0061] A first voltage can be applied to the first electrode AE ​​via the transistor TR, and a second voltage having a lower level than the first voltage can be applied to the second electrode CE. Holes injected into the light-emitting layer EML combine with electrons to form excitons, and the light-emitting element OLED can emit light as the excitons transition to the bottom state.

[0062] Figure 5a is a perspective view of an inkjet printing apparatus according to one embodiment of the present invention. Figure 5b is a cross-sectional view showing the section obtained by cutting along line I-I' in Figure 5a.

[0063] Referring to Figures 5a and 5b, the inkjet printing apparatus IPD may include a first stage STG1, a second stage STG2, a substrate SUB, a head unit HU, a camera unit CRU, and a frame FR.

[0064] The second stage STG2 may be placed on top of the first stage STG1. The second stage STG2 may include a heater. Adsorption holes (not shown) may be defined in the second stage STG2. A substrate SUB may be adsorbed and fixed onto the second stage STG2 through the adsorption holes of the second stage STG2.

[0065] The substrate SUB may be placed on the second stage STG2. In plan view, the substrate SUB may include a print area TPA superimposed on a heater HTR. The heater HTR can heat the ink (see Figure 3) to dry the ink. In other words, ink can be applied to the print area TPA and then dried by the heater HTR.

[0066] The circuit board SUB may move in the second direction DR2 during the second stage STG2. As the circuit board SUB moves in the second direction, the head unit HU may appear to move in the second direction DR2 on top of the second stage STG2.

[0067] The ink may contain a substance that emits excitation light in response to electromagnetic waves. The ink may also contain a substance that emits light at a specific wavelength when irradiated with light of a particular wavelength. For example, the ink may be a quantum dot material that emits light at a specific wavelength when irradiated with ultraviolet light.

[0068] The head unit HU can discharge ink onto the substrate SUB. The ink discharged from the head unit HU can be cured to form an emissive layer EML (see Figure 4). The details of the head unit HU will be described later.

[0069] The camera unit CRU may be positioned on the side of the head unit HU. The camera unit CRU can irradiate the ink INK with electromagnetic waves and measure the excitation light generated from the ink INK. The frame FR may connect the first stage STG1 and the head unit HU.

[0070] Figure 6 is a schematic perspective view showing a head unit according to one embodiment of the present invention. Figure 7 is a plan view of an inkjet printing apparatus according to one embodiment of the present invention.

[0071] For the sake of explanation, in Figure 6, the head unit HU is shown as the ink supply unit ISU, print head PHD, nozzles NZ1, NZ2, NZ3, and camera unit CRU. In Figure 7, the frame FR and heater HTR are omitted.

[0072] Referring to Figures 6 and 7, the head unit HU is located on a substrate SUB and may include multiple print heads PHD, multiple nozzles NZ1, NZ2, NZ3, and an ink supply unit ISU.

[0073] Nozzles NZ1, NZ2, and NZ3 may be located on the underside of each printhead PHD. Nozzles NZ1, NZ2, and NZ3 may include multiple first nozzles NZ1 arranged in the first direction DR1. The first nozzles NZ1 may be defined as the first nozzle group NZ1G. Nozzles NZ1, NZ2, and NZ3 may include multiple second nozzles NZ2 arranged in the first direction DR1. The second nozzles NZ1 may be defined as the second nozzle group NZ2G. Nozzles NZ1, NZ2, and NZ3 may include multiple third nozzles NZ3 arranged in the first direction DR1. The third nozzles NZ3 may be defined as the third nozzle group NZ3G.

[0074] The first nozzle group NZ1G, the second nozzle group NZ2G, and the third nozzle group NZ3G can be arranged in the second direction DR1 which intersects the first direction DR1. In other words, the first nozzle group NZ1G, the second nozzle group NZ2G, and the third nozzle group NZ3G can be connected to the ink supply device ISU and grouped together. Figures 6 and 7 show exemplary nozzles NZ1, NZ2, and NZ3 of the first nozzle group NZ1G, the second nozzle group NZ2G, and the third nozzle group NZ3G, but the number of nozzles NZ1, NZ2, and NZ3 is not limited to these, as long as the nozzles NZ1, NZ2, and NZ3 can form groups.

[0075] The first nozzle NZ1 and the third nozzle NZ3 may be arranged in the same corresponding column in the second direction DR2. The first nozzle NZ1 and the third nozzle NZ3 may overlap in the second direction DR2. The second nozzle NZ2 may be located in a column between the columns in which the first nozzle NZ1 is located. In other words, the second nozzle NZ2 may not overlap with the first nozzle NZ1 and the third nozzle NZ3 in the second direction DR2. Viewed from the second direction DR2, the second nozzle NZ2 may be located between the first nozzle NZ1 and the third nozzle NZ3.

[0076] The ink supply unit (ISU) can be connected to the print head (PHD). The ink supply unit (ISU) can supply ink (see Figure 2) to the print head (PHD). Ink (INK) can be discharged from nozzles NZ1, NZ2, and NZ3 via the ink supply unit (ISU).

[0077] Figures 8 to 10 show the printed area of ​​a substrate according to one embodiment of the present invention.

[0078] Referring to Figures 5a and 8, ink can be discharged from the first nozzle NZ1, the second nozzle NZ2, and the third nozzle NZ3. The ink discharged from the first nozzle NZ1, the second nozzle NZ2, and the third nozzle NZ3 can form a first ink pattern IKP1 in the print area TPA. In other words, ink can be supplied to the print area TPA by the nozzles NZ of the inkjet printing device IPD to form the first ink pattern IKP1.

[0079] The first nozzle NZ1, the second nozzle NZ2, and the third nozzle NZ3 may be arranged at equal intervals in the first direction DR1. The spacing of the first ink pattern IKP1 in the first direction DR1 may be equal. The first ink pattern IKP1 may be arranged at equal intervals in the first direction DR1 by simultaneously dispensing ink from the first nozzle NZ1, the second nozzle NZ2, and the third nozzle NZ3.

[0080] Referring to Figures 5a, 5b, and 9, after the ink is placed in the print area TPA, a heater HTR located below the print area TPA and inside the second stage STG2 can apply heat to the ink placed in the print area TPA. The heater HTR can apply heat to the ink, causing the solvent in the ink to evaporate and form the first ink pattern IKP1a.

[0081] The first ink pattern IKP1a may have a ring shape in plan view. The fluidity of the ring-shaped first ink pattern IKP1a may be reduced as the solvent evaporates and it becomes a liquid. Therefore, the phenomenon of the first ink pattern IKP1a moving in the print area TPA may be reduced or eliminated. In addition, noise formed by the reflection or scattering of electromagnetic waves emitted from the camera unit CRU by the solvent of the ink INK may be reduced or eliminated.

[0082] When the electromagnetic wave irradiation unit of the camera unit CRU irradiates the first ink pattern IKP1a with electromagnetic waves, because the first ink pattern IKP1a has a ring shape, excitation light for the first ink pattern IKP1a may not be generated in the center by the electromagnetic waves. Therefore, the center position of the first ink pattern IKP1a can be accurately measured, and the impact position of the ink before drying can be accurately measured. In addition, the amount of emission of excitation light for the first ink pattern IKP1a can be measured, and the volume of ink discharged from the nozzle NZ before drying can be measured.

[0083] Referring to Figures 5a, 8, and 10, it is shown that the first ink pattern IKP1b is formed by moving in the first direction DR1 and the second direction DR2, resulting in a positional error. The error in the first direction DR1 of the first ink pattern IKP1b can be corrected by stopping the ejection of ink from the print head PHD and ejecting ink from print heads other than the one that ejected the first ink pattern IKP1b.

[0084] The error in the second direction DR of the first ink pattern IKP1b can be corrected by adjusting the ink ejection timing of the nozzle NZ to compensate for the error in the second direction DR2. In other words, if a position error occurs in the second direction DR2, the head unit HU can be moved to the second direction DR2 before ejecting the ink to compensate for the position error in the second direction DR2.

[0085] Furthermore, each print head (PHD) may include an input element (not shown). If the ink discharge volume is large, the amount of excitation light emitted by the ink in response to electromagnetic waves may be large. Conversely, if the ink discharge volume is small, the amount of excitation light emitted by the ink in response to electromagnetic waves may be small. Therefore, the ink discharge volume can be measured by the amount of excitation light measured by the camera unit (CRU). If an error occurs in the ink discharge volume, the amount of ink discharged can be adjusted by adjusting the discharge drive waveform for the pressure element.

[0086] Figures 11a to 11d are schematic cross-sectional views showing a method for manufacturing a display panel according to one embodiment of the present invention. Figures 11e and 11f are schematic perspective views showing a method for manufacturing a display panel according to one embodiment of the present invention.

[0087] For the sake of explanation, Figures 11e and 11f omit all components of the head unit HU except for the print head PHD and nozzle NZ.

[0088] Referring to Figure 11a, the method for manufacturing the display panel may include the step of preparing the first stage STG1.

[0089] Referring to Figure 11b, the method for manufacturing the display panel may include the step of placing a second stage STG2 on top of a first stage STG1. A heater may be placed inside the second stage STG2.

[0090] Referring to Figure 11c, the method for manufacturing the display panel may include the step of placing a substrate SUB on the second stage STG2. In plan view, the substrate SUB may include a printed area TPA that overlaps with the heater HTR.

[0091] Referring to Figures 5a and 11d, the method for manufacturing the display panel may include the step of placing a head unit HU on a substrate SUB. The method for manufacturing the display panel may also include the step of placing a camera unit CRU on the side of the head unit HU to measure excitation light generated from the ink by irradiating the ink with electromagnetic waves.

[0092] The head unit HU may include multiple print heads PHD, an ink supply unit ISU that supplies ink containing a substance that emits excitation light in response to electromagnetic waves to the print heads PHD, and multiple nozzles NZ positioned on the underside of each print head PHD.

[0093] Referring to Figures 5a, 5b, and 11e, a method for manufacturing a display panel may include the step of discharging ink from a nozzle NZ into a print area TPA to form a first ink pattern IKP1. A method for manufacturing a display panel may also include the step of measuring the excitation light of the first ink pattern IKP1 via a camera unit CRU.

[0094] The camera unit CRU may further include an electromagnetic wave irradiation unit (not shown) that irradiates electromagnetic waves. After the nozzle NZ ejects ink INK into the print area TPA, the ink INK may be placed in the print area TPA to form a first ink pattern IKP1.

[0095] The step of the camera unit CRU measuring the excitation light of the first ink pattern IKP1 may include the step of the electromagnetic wave irradiation unit irradiating the first ink pattern IKP1 with electromagnetic waves to measure the center position and intensity of the excitation light. Once the first ink pattern IKP1 emits excitation light in response to the electromagnetic waves, the camera unit CRU may measure the excitation light. By measuring the excitation light, it can be determined whether the first ink pattern IKP1 has been discharged at equal intervals or whether a target volume of ink has been discharged.

[0096] After the camera unit CRU measures the excitation light of the first ink pattern IKP1, the method for manufacturing the display panel may further include the step of the ink supply unit ISU adjusting the ink discharge time. If a target volume of ink is not discharged, the ink supply unit ISU may adjust the ink discharge time so that a target volume of ink is discharged.

[0097] Each printhead PHD may further include an input element (not shown). After the camera unit CRU measures the excitation light of the first ink pattern IKP1, the method for manufacturing the display panel may further include the step of adjusting the amount of ink discharged by the nozzle NZ using a pressure element. After measuring the excitation light of the first ink pattern IKP1, if a target volume of ink is not discharged, the discharge amount of ink can be adjusted by adjusting the ejection drive waveform to the pressure element of the printhead PHD. As a result, a target volume of ink can be discharged from the nozzle NZ.

[0098] After the step of the camera unit CRU measuring the excitation light of the first ink pattern IKP1, the method for manufacturing the display panel may further include the step of the heater HTR drying the first ink pattern IKP1.

[0099] The first ink pattern IKP1 can be dried to form a first ink pattern IKP1a (see Figure 9) in which the solvent of the ink has evaporated. Through the dried first ink pattern IKP1a, errors in the volume or position of the ink due to reflection or scattering of the ink when excitation light is emitted can be reduced or eliminated.

[0100] Referring to Figures 5a and 11f, the method for manufacturing a display panel may include the step of forming a second ink pattern IKP2 on a substrate SUB separated from the print area TPA from a nozzle NZ. An inkjet printing apparatus IPD is positioned on the substrate SUB and may further include the second ink pattern IKP2 separated from the print area TPA. The method for manufacturing a display panel may include the step of curing the second ink pattern IKP2 to form an emissive layer EML (see Figure 4). After forming a first ink pattern IKP1 (see Figure 11e) and correcting the ink discharge and ink impact position, the head unit HU may move in a second direction. That is, the nozzle NZ may move in a second direction DR2 to discharge ink onto the substrate SUB separated from the print area TPA. The ink may be discharged onto the substrate SUB to form the second ink pattern IKP2. The second ink pattern IKP2 may be cured on the substrate SUB to form the emissive layer EML.

[0101] Although preferred embodiments of the present invention have been described so far with reference, a person skilled in the art or a person with ordinary knowledge in the art will understand that the present invention can be modified and altered in various ways without departing from the spirit and art domain of the invention as described in the claims below.

[0102] Therefore, the technical scope of the present invention is not limited to what is described in the detailed description of the specification, but should be determined by the claims. [Explanation of symbols]

[0103] STG1: Stage 1 STG2: Stage 2 HTR: Heater TPA: Print Area PHD: Printhead INK: Ink ISU: Ink supply unit HU: Head unit CRU: Camera Unit IKP1: First Ink Pattern IKP2: Second ink pattern NZ1: First nozzle NZ2: Second nozzle NZ3: Third nozzle

Claims

1. Stage 1 and A second stage is positioned on the first stage, on which a substrate is positioned that includes a heater and a printed area that overlaps with the heater in a plan view, A head unit is provided, which is arranged on the substrate and includes a plurality of print heads and an ink supply device that supplies ink containing a substance that emits excitation light in response to electromagnetic waves to the print heads. An inkjet printing apparatus comprising: a camera unit positioned on the side of the head unit, which irradiates the ink with electromagnetic waves to measure the excitation light generated from the ink.

2. The inkjet printing apparatus according to claim 1, wherein the head unit further includes a plurality of nozzles, each of which is positioned on the lower surface of the print head.

3. The aforementioned nozzle is Defined as a first nozzle group, it consists of a plurality of first nozzles arranged in a first direction, A second nozzle group is defined as a plurality of second nozzles arranged in the first direction, A third nozzle group is defined and includes a plurality of third nozzles arranged in the first direction, The inkjet printing apparatus according to claim 2, wherein the first nozzle group, the second nozzle group, and the third nozzle group are arranged in a second direction intersecting the first direction.

4. The first nozzle and the third nozzle are arranged in the same corresponding row in the second direction. The inkjet printing apparatus according to claim 3, wherein the second nozzle is arranged in a row between the rows in which the first nozzle is arranged.

5. The inkjet printing apparatus according to claim 2, wherein the ink is supplied to the print area of ​​the substrate by the nozzle to form a first ink pattern.

6. The inkjet printing apparatus according to claim 5, wherein the first ink pattern has a ring shape in plan view.

7. The inkjet printing apparatus according to claim 2, wherein the ink is supplied by the nozzle to an area of ​​the substrate separated from the print area to form a second ink pattern.

8. The inkjet printing apparatus according to claim 1, wherein the second stage is defined by adsorption pores.

9. The inkjet printing apparatus according to claim 1, wherein the camera unit further comprises an electromagnetic wave irradiation unit.

10. The inkjet printing apparatus according to claim 1, wherein each print head further comprises a pressure element.

11. The inkjet printing apparatus according to claim 1, further comprising a frame connecting the first stage and the head unit.

12. The first step is to prepare the first stage, The steps include placing a second stage, which includes a heater, on top of the first stage, The steps include placing a substrate on the second stage, including a printed area that overlaps with the heat in a plan view, The steps include arranging a head unit on the substrate, which includes a plurality of print heads, an ink supply device that supplies ink containing a substance that emits excitation light in response to electromagnetic waves to the print heads, and a plurality of nozzles arranged on the lower surface of each of the print heads, The steps include: arranging a camera unit on the side of the head unit to measure the excitation light generated from the ink by irradiating the ink with electromagnetic waves; The steps include: providing the ink to the printed area of ​​the substrate by the nozzle to form a first ink pattern; The camera unit measures the excitation light of the first ink pattern, The steps include: discharging the ink from the nozzle to a region of the substrate separated from the printed area to form a second ink pattern; The steps include curing the second ink pattern to form a light-emitting layer, A method for manufacturing a display panel, comprising: a display panel manufactured by curing the second ink pattern to form the light-emitting layer.

13. The camera unit further includes an electromagnetic wave irradiation unit, The step of the camera unit measuring the excitation light of the first ink pattern is: The method for manufacturing a display panel according to claim 12, comprising the step of irradiating the first ink pattern with electromagnetic waves using an electromagnetic wave irradiation unit to measure the central position and light intensity of the excitation light.

14. After the camera unit measures the excitation light of the first ink pattern, The method for manufacturing a display panel according to claim 12, further comprising the step of adjusting the ink discharge time of the ink supply device.

15. Each of the print heads further includes a pressure element, After the camera unit measures the excitation light of the first ink pattern, The method for manufacturing a display panel according to claim 12, further comprising the step of the pressure element adjusting the amount of ink discharged by the nozzle.

16. After the camera unit measures the excitation light of the first ink pattern, The method for manufacturing a display panel according to claim 12, further comprising the step of drying the first ink pattern with the heater.

17. Electronic devices are A display device that displays images, A processor that processes video signals and provides them to the display device, The aforementioned display device is The first step is to prepare the first stage, The steps include placing a second stage, which includes a heater, on top of the first stage, The steps include placing a substrate on the second stage, including a printed area that overlaps with the heat in a plan view, The steps include arranging a head unit on the substrate, which includes a plurality of print heads, an ink supply device that supplies ink containing a substance that emits excitation light in response to electromagnetic waves to the print heads, and a plurality of nozzles arranged on the lower surface of each of the print heads, The steps include: arranging a camera unit on the side of the head unit to measure the excitation light generated from the ink by irradiating the ink with electromagnetic waves; The steps include: providing the ink to the printed area of ​​the substrate by the nozzle to form a first ink pattern; The camera unit measures the excitation light of the first ink pattern, The steps include: discharging the ink from the nozzle to a region of the substrate separated from the printed area to form a second ink pattern; The steps include curing the second ink pattern to form a light-emitting layer, An electronic device comprising: a display panel manufactured by curing the second ink pattern to form the light-emitting layer;

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