This application claims priority under 35 USC § 119 to Korean Patent Application No. 10-2020-0067710, filed on Jun. 4, 2020 in the Korean Intellectual Property Office (KIPO), the disclosure of which is incorporated by reference herein in its entirety.
The present disclosure relates to a display device, and more particularly to a display device including a bank structure.
The organic light emitting display device is capable of emitting light by itself, and may generate a color image without a separate light source such as a backlight.
Recently, the organic light emitting display device including an organic light emitting diode and a color converting layer has been developed. The color converting layer may convert a wavelength of light provided by the light emitting diode. Accordingly, light having a color that is different from the color of incident light may be emitted.
The organic light emitting diode and the color converting layer may be formed by an ink jet process. During the ink jet process, ink may be applied between bank structures that serve as wells. However, the ink may not be applied accurately between the bank structures and may be erroneously applied on the bank structure. In this case, a separate layer disposed on the bank structure may have a non-uniform height so that a gap defect may occur in the organic light emitting display device.
The present disclosure provides a display device capable of preventing a gap defect.
Some embodiments of the present disclosure provide a method of operating a display device that is capable of preventing a gap defect.
According to one embodiment, a display device includes a substrate including a light emitting area and a light blocking area that surrounds the light emitting area and a bank structure disposed in the light blocking area and having an opening that corresponds to the light emitting area, and the bank structure has a concave portion on an upper surface.
In one embodiment, the concave portion may reach an upper surface of the substrate.
In one embodiment, the concave portion may be spaced apart from an upper surface of the substrate.
In one embodiment, the display device may further include an organic light emitting diode disposed in the opening, and the organic light emitting diode may include a lower electrode, a light emitting layer disposed on the lower substrate and an upper electrode disposed on the light emitting layer.
In one embodiment, the display device may further include a color converting layer disposed in the opening, and the color converting layer may include a wavelength converting particle and a resin portion.
In one embodiment, the bank structure may include a light blocking material.
In one embodiment, the display device may further include a color filter layer overlapping the color converting layer and a light blocking layer overlapping the bank structure.
In one embodiment, the color filter layer may be disposed between the color converting layer and the substrate, and the light blocking layer may be disposed between the bank structure and the substrate.
According to one embodiment, a display device includes a substrate including a light emitting area and a light blocking area that surrounds the light emitting area and a bank structure disposed in the light blocking area and having an opening that corresponds to the light emitting area, and the bank structure has a concave portion on an upper surface, and the bank structure includes a first portion and a second portion that is disposed on the first portion and includes the concave portion.
In one embodiment, the concave portion may reach an upper surface of the first portion.
In one embodiment, the concave portion may be spaced apart from an upper surface of the substrate.
In one embodiment, the display device may further include an organic light emitting diode disposed in the opening, and the organic light emitting diode may include a lower electrode, a light emitting layer disposed on the lower substrate and an upper electrode disposed on the light emitting layer.
In one embodiment, the display device may further include a color converting layer disposed in the opening, and the color converting layer may include a wavelength converting particle and a resin portion.
In one embodiment, the bank structure may include a light blocking material.
In one embodiment, the display device may further include a color filter layer overlapping the color converting layer and a light blocking layer overlapping the bank structure.
In one embodiment, the color filter layer may be disposed between the color converting layer and the substrate, and the light blocking layer may be disposed between the bank structure and the substrate.
According to one embodiment, a method of manufacturing a display device includes: preparing a substrate including a light emitting area and a light blocking area that surrounds the light emitting area; forming a bank structure having an opening on the substrate, wherein the opening corresponds to the light emitting area of the substrate; forming a concave portion on an upper surface of the bank structure; applying an ink into the opening; and drying or curing the ink.
In one embodiment, the ink may contain an organic light emitting material.
In one embodiment, the ink may contain a wavelength converting particle.
In one embodiment, forming the bank structure may include: forming a first potion of the bank structure on the substrate; and forming a second portion of the bank structure having the concave portion on the first portion.
As described above, the display device of the present disclosure may include a substrate including a light emitting area and a light blocking area that surrounds the light emitting area and a bank structure disposed in the light blocking area having an opening that corresponds to the light emitting area, and having a concave portion on an upper surface.
Accordingly, ink erroneously applied on the bank structures may be accommodated in the concave portion. As a result, gap defects that may be caused by erroneously applying the ink on the bank structure may be prevented.
Illustrative, non-limiting embodiments of the present disclosure will be more clearly understood from the following detailed description in conjunction with the accompanying drawings.
Hereinafter, embodiments of the present disclosure will be explained in detail with reference to the accompanying drawings.
Referring to
The second substrate 2000 may include a color converting layer 215 that converts a wavelength of light emitted from the light emitting diode. In addition, the second substrate 2000 may include a color filter that transmits light of a specific color.
The display device may include a display area displaying an image and a peripheral area that surrounds the display area. The display area may include a plurality of light emitting areas that emit light, and a light blocking area BA that surrounds the light emitting areas. Light emitted by the display device may be displayed to the outside through the light emitting areas.
The light emitting areas may emit light of different colors. For example, the display device may include a first light emitting area LA1 that emits first color light, a second light emitting area LA2 that emits second color light, and a third light emitting area LA3 that emits third color light.
In an embodiment, the first light emitting area LA1 may emit red light, the second light emitting area LA2 may emit blue light, and the third light emitting area LA3 may emit green light. However, the present disclosure is not limited thereto. For example, the light emitting areas LA1, LA2, and LA3 may emit light of yellow, cyan, and magenta colors.
In an embodiment, the light emitting areas that emit light of the same color may be arranged along a first direction D1. The light emitting areas that emit light of different colors may be arranged along a second direction D2 that intersects with the first direction D1. For example, the first direction D1 may be a column direction, and the second direction D2 may be a row direction.
In an embodiment, the first light emitting area LA1, the second light emitting area LA2, and the third light emitting area LA3 may be shifted along the column direction to have different center lines in the row direction. However, the present disclosure is not limited thereto, and the light emitting areas LA1, LA2, and LA3 may be aligned to have the same center line in the row direction.
In an embodiment, the light emitting areas LA1, LA2, and LA3 may emit light of four or more colors. For example, the light emitting areas LA1, LA2, and LA3 may further emit at least one of yellow, cyan, and magenta lights in addition to red, green, and blue lights. Further, the light emitting areas LA1, LA2, and LA3 may be combined to emit white light.
In an embodiment, the light emitting areas LA1, LA2, and LA3 may have different shapes. However, the present disclosure is not limited thereto. For example, the light emitting areas LA1, LA2, and LA3 may have the same shape. In addition, the light emitting areas LA1, LA2, and LA3 may have various shapes such as a square, a rhombus, a triangle, and a circle, and an edge or a corner of each pixel may have a round shape or a chamfered shape.
In an embodiment, the light emitting areas LA1, LA2, and LA3 may have different sizes. For example, the first light emitting area LA1 emitting red light and the third light emitting area LA3 emitting green light may have larger areas than the second light emitting area LA2 that emits blue light. However, the present disclosure is not limited thereto, and the light emitting areas LA1, LA2, and LA3 may have the same area.
Referring to
The first base substrate 100 may include glass, quartz, sapphire, or a polymer material.
In an embodiment, the driving element TR may include a thin film transistor. The display device may include a plurality of thin film transistors.
A channel layer of the thin film transistor may include amorphous silicon, polycrystalline silicon, or a metal oxide semiconductor. Examples of the metal oxide semiconductor may include, but are not limited to, indium (“In”), zinc (“Zn”), gallium (“Ga”), tin (“Sn”), titanium (“Ti”), aluminum (“Al”), hafnium (“Hf”), zirconium (“Zr”), magnesium (“Mg”), and the like. Examples of the metal oxide semiconductor may include, but are not limited to, zinc oxide (“ZnOx”), gallium oxide (“GaOx”), titanium oxide (“TiOx”), tin oxide (“SnOx”), indium oxide (“InOx”), indium-gallium oxide (“IGO”), indium-Zinc oxide (“IZO”), indium-tin oxide (“ITO”), gallium-zinc oxide (“GZO”), zinc-magnesium oxide (“ZMO”), zinc-tin oxide (“ZTO”), zinc-zirconium oxide (“ZnZrxOy”), indium-gallium-Zinc oxide (“IGZO”), indium-zinc-tin oxide (“IZTO”), indium-gallium-hafnium oxide (“IGHO”), tin-aluminum-zinc oxide (“TAZO”), and indium-gallium-tin oxide (“IGTO”), and the like.
The display device may The insulating layer 110 may cover the driving element TR. The insulating layer 110 may include at least one inorganic insulating layer and at least one organic insulating layer.
The lower electrode 120 may correspond to an anode of the organic light emitting diode OLED. The lower electrode 120 may be a transmissive electrode or a reflective electrode according to a light emitting type of the display device. The lower electrode 120 serving as a reflective electrode may include gold (“Au”), silver (“Ag”), aluminum (“Al”), copper (“Cu”), nickel (“Ni”), platinum (“Pt”), magnesium (“Mg”), chromium (“Cr”), tungsten (“W”), molybdenum (“Mo”), titanium (“Ti”), or the like, and may further include a metal oxide layer such as indium-tin oxide, and indium-zinc oxide.
A bank structure may be disposed on the insulating layer 110 to cover at least a portion of the lower electrode 120. In an embodiment, in
The light emitting layer 140 may include a single layer or a multilayer structure that includes at least one of functional layers such as a hole injection layer (HIL), a hole transport layer (HTL), an organic light emitting layer, an electron transport layer (ETL), and an electron injection layer (EIL). The light emitting layer 140 may include a low molecular weight organic compound or a high molecular weight organic compound. The light emitting layer 140 may generate light of various colors. For example, the light emitting layer 140 may generate light having one of blue, green, and red colors. In an embodiment, the light emitting layer 140 may be disposed in the opening OP of the pixel defining layer 130 by an inkjet process.
The upper electrode 150 may be a transmissive electrode or a reflective electrode according to a light emitting type of the display device. For example, the upper electrode 150 may include a metal, an alloy, a metal nitride, a metal fluoride, a conductive metal oxide, or any combination thereof. For example, the upper electrode 150 may extend continuously in the display area across a plurality of pixels.
The first substrate 1000 may further include an encapsulation layer TFE that is disposed on the upper electrode 150. The encapsulation layer TFE may continuously extend to cover the entire display area.
The encapsulation layer TFE may include a plurality of layers. For example, the encapsulation layer TFE may include a stacked structure of an organic thin film and an inorganic thin film. For example, in the embodiment shown in
The organic thin film 170 may include a cured polymer such as polyacrylate. For example, the cured polymer may be formed by a crosslinking reaction of a monomer. The first and second inorganic thin films 160 and 180 may include silicon oxide, silicon nitride, silicon carbide, aluminum oxide, tantalum oxide, hafnium oxide, zirconium oxide, titanium oxide, or the like.
The second substrate 2000 may include the color converting layer 215 that converts a wavelength of light emitted from the organic light emitting diode OLED of the first substrate 1000. In addition, the second substrate 2000 may further include a second base substrate 240, a color filter layer 235 overlapping the color converting layer 215, a light blocking layer 230 overlapping the light blocking area BA, a partition wall 210, and a filling layer 200. In an embodiment, the filling layer 200 may be disposed on the liquid crystal layer 300 and may contact the liquid crystal layer 300.
The color filter layer 235 may be disposed between the second base substrate 240 and the color converting layer 215. The color filter layer 235 may transmit light of a specific color by filtering light passing through the color filter layer 235. In an embodiment, the color filter layer 235 may overlap the first light emitting area LA1. For example, the color filter layer 235 may transmit red light. The light blocking layer 230 may be formed in the light blocking area BA. In an embodiment, the light blocking layer 230 may partially overlap the color filter layer 235. For example, the light blocking layer 230 may include one or more of a metal, an alloy, an insulating inorganic material, and an organic material. The light blocking layer 230 may include a silicon-germanium alloy, germanium, titanium oxide, or the like. The light blocking layer 230 may include a light blocking material such as a pigment, a dye, or carbon black.
The second substrate 2000 may further include a protective layer 220 that overlaps the light blocking layer 230. The protective layer 220 may include an inorganic material such as silicon oxide or silicon nitride.
The color converting layer 215 may include wavelength converting particles 215a and a resin portion 215b. For example, the wavelength converting particles 215a may include quantum dots. The quantum dots may be a semiconductor material having nano crystals. The quantum dots may have a band gap depending on their composition and size. Accordingly, the quantum dots may absorb incident light and emit light having a wavelength different from that of the incident light. For example, the quantum dots may include a group II-VI compound, a group III-V compound, a group IV-VI compound, a group IV element, a group IV compound, and/or any combination thereof.
For example, the quantum dots may have a core/shell structure including a core and a shell that surrounds the core. For example, the core and the shell may include different materials.
The quantum dots may be dispersed in the resin portion 215b. For example, the resin portion 215b may include an epoxy resin, an acrylic resin, a phenol resin, a melamine resin, a cardo resin, an imide resin, or the like.
The color converting layer 215 may further include a scattering material 215c. The scattering material 215c may scatter the incident light without substantially changing the wavelength of the incident light.
The scattering material 215c may include a metal oxide or an organic material. For example, the metal oxide may include titanium oxide (“TiO2”), zirconium oxide (“ZrO2”), aluminum oxide (“Al2O3”), indium oxide (“In2O3”), zinc oxide (“ZnO”), tin oxide (“SnO2”), or the like, and the organic material may include an acrylic resin or a urethane resin.
The second substrate 2000 may include a bank structure surrounding the color converting layer 215. In
In an embodiment, the partition wall 210 may include a light blocking material to serve as a black matrix. For example, at least a portion of the partition wall 210 may include a light blocking material such as a pigment, a dye, or carbon black. For example, the partition wall 210 may overlap at least a portion of the light blocking area BA.
The filling layer 200 may be disposed on the partition wall 210. The filling layer 200 may include an inorganic material such as silicon oxide or silicon nitride.
Referring to
In an embodiment, the substrate 500 may include the first base substrate 100 and the insulating layer 110 of the first substrate 1000 shown in
In an embodiment, the bank structure 510 may include a concave portion 515. The concave portion 515 may be formed on an upper surface of the bank structure 510. The concave portion 515 may be formed to be concave in the thickness direction of the substrate 500. The concave portion 515 may be spaced apart from the upper surface of the substrate 500.
In an embodiment, the organic light emitting diode OLED may be formed in the opening OP of the bank structure 510 by an inkjet process. In an embodiment, the color converting layer 215 of the second substrate 2000 shown in
The concave portion 515 of the bank structure 510 may accommodate ink that may be erroneously applied by the inkjet device 400 in an ink jet process. Accordingly, a gap defect that may otherwise occur when forming a separate layer on the bank structure 510 may be prevented.
Referring to
The concave portion 525 of the bank structure 520 may accommodate ink that may be erroneously applied by the inkjet device 400 in the ink jet process. Accordingly, a gap defect that may otherwise occur when forming a separate layer on the bank structure 520 may be prevented.
Referring to
In an embodiment, the bank structure 610 may have the opening OP corresponding to the first light emitting area LA1. In
In an embodiment, the substrate 600 may include the first base substrate 100 and the insulating layer 110 of the first substrate 1000 shown in
In an embodiment, the bank structure 610 may include a concave portion 625. The concave portion 625 may be formed on an upper surface of the second portion 620. The concave portion 625 may be formed to be concave in the thickness direction of the substrate 600. The concave portion 625 may be spaced apart from the upper surface of the first portion 615.
In an embodiment, the organic light emitting diode OLED may be formed in the opening OP of the bank structure 610 by the inkjet process. In an embodiment, the color converting layer 215 of the second substrate 2000 shown in
The concave portion 625 of the bank structure 610 may accommodate ink that may be erroneously applied by the inkjet device 400 in the ink jet process. Accordingly, a gap defect that may otherwise occur when forming a separate layer on the bank structure 610 may be prevented.
Referring to
The concave portion 640 of the bank structure 630 may accommodate ink that may be erroneously applied by the inkjet device 400 in the ink jet process. Accordingly, a gap defect that may otherwise occur when forming a separate layer on the bank structure 630 may be prevented.
Referring to
In an embodiment, the concave portion 515 of the bank structure 510 may be formed by an etching process. For example, the concave portion 515 may be formed by wet etching, dry etching, laser etching, or the like.
Referring to
The bank structure 510 having the concave portion 515 may accommodate ink that is erroneously applied by the inkjet device 400 in the ink jet process. Accordingly, a gap defect that may otherwise occur when forming a separate layer on the bank structure 510 may be prevented.
Referring to
In an embodiment, the first portion 615 of the bank structure 610 may be formed on the light blocking area BA of the substrate 600, and the second portion 620 of the bank structure 610 that has the concave portion 625 may be formed on the first portion 615. In an embodiment, the second portion 620 having a flat top surface may be disposed on the first portion 615, and the concave portion 625 may be formed by etching the flat top surface of the second portion 620. The concave portion 625 may be formed by dry etching, wet etching, laser etching, or the like.
Referring to
The bank structure 610 having the concave portion 625 may accommodate ink that is erroneously applied by the inkjet device 400 in the ink jet process. Accordingly, a gap defect that may otherwise occur when forming a separate layer on the bank structure 610 may be prevented.
The inventive concepts may be applied to any display device, and any electronic device including the display device. For example, the inventive concepts may be applied to a mobile phone, a smart phone, a tablet computer, a wearable electronic device, a virtual reality (VR) device, a television (TV), a digital TV, a three-dimensional (3D) TV, a personal computer (PC), a home appliance, a laptop computer, a personal digital assistant (PDA), a portable multimedia player (PMP), a digital camera, a music player, a portable game console, a navigation device, etc.
The foregoing is illustrative of some embodiments of the present disclosure and is not to be construed as limiting thereof. Although some embodiments of the present disclosure have been described, those skilled in the art will readily appreciate that modifications are possible in the disclosed embodiments without materially departing from the novel teachings and advantages of the present inventive concept. Accordingly, such modifications are intended to be included within the scope of the present inventive concept as defined in the claims. Therefore, it is to be understood that the foregoing is illustrative of various embodiments of the present disclosure and is not to be construed as limited to the specific embodiments disclosed herein, and that modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the present inventive concepts including the appended claims.
Number | Date | Country | Kind |
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10-2020-0067710 | Jun 2020 | KR | national |