US20150279917A1 - Organic light emitting display - Google Patents
Organic light emitting display Download PDFInfo
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- US20150279917A1 US20150279917A1 US14/473,545 US201414473545A US2015279917A1 US 20150279917 A1 US20150279917 A1 US 20150279917A1 US 201414473545 A US201414473545 A US 201414473545A US 2015279917 A1 US2015279917 A1 US 2015279917A1
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- reflection reduction
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- emitting display
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
- H10K59/10—OLED displays
- H10K59/12—Active-matrix OLED [AMOLED] displays
- H10K59/126—Shielding, e.g. light-blocking means over the TFTs
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/80—Constructional details
- H10K50/805—Electrodes
- H10K50/81—Anodes
- H10K50/818—Reflective anodes, e.g. ITO combined with thick metallic layers
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- H01L27/3272—
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
- H01L27/12—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being other than a semiconductor body, e.g. an insulating body
- H01L27/1214—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being other than a semiconductor body, e.g. an insulating body comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
- H01L27/124—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being other than a semiconductor body, e.g. an insulating body comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/80—Constructional details
- H10K50/85—Arrangements for extracting light from the devices
- H10K50/856—Arrangements for extracting light from the devices comprising reflective means
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/80—Constructional details
- H10K50/86—Arrangements for improving contrast, e.g. preventing reflection of ambient light
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
- G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
- G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
- G09G3/3208—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
- G09G3/3225—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED] using an active matrix
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/80—Constructional details
- H10K50/86—Arrangements for improving contrast, e.g. preventing reflection of ambient light
- H10K50/865—Arrangements for improving contrast, e.g. preventing reflection of ambient light comprising light absorbing layers, e.g. light-blocking layers
Definitions
- Embodiments of the invention relate to an organic light emitting display.
- An organic light emitting element used in an organic light emitting display is a self-emitting element having a light emitting layer between two electrodes.
- the organic light emitting element receives electrons and holes from a cathode serving as an electron injection electrode and an anode serving as a hole injection electrode and injects the electrons and the holes into the light emitting layer.
- the injected electrons and holes are combined to form an exciton.
- the organic light emitting element emits light when the exciton drops from an excited state to a ground state.
- the organic light emitting display forms a display panel using the organic light emitting element.
- the display panel may be classified into a top emission type, a bottom emission type, and a dual emission type depending on an emission direction of light. Further, the display panel may be classified into a passive matrix type and an active matrix type depending on a driving method.
- the display quality (visibility, luminance, etc.) of the organic light emitting display may be reduced due to the incidence of ambient light.
- the related art limited incidence of the ambient light by attaching a circular polarizer to an external surface (or a display surface) of the display panel.
- an organic light emitting display comprising a display panel including subpixels and a driver configured to drive the display panel, wherein the display panel includes a reflection reduction layer, which is formed on an internal surface or an external surface of a substrate and is positioned correspondingly to a non-opening area defined in the substrate.
- an organic light emitting display comprises a substrate and a plurality of sub-pixels.
- Each sub-pixel has a first area for light emission; a second area including a transistor electrode, the second area being different than the first area; and a reflection reduction layer in the second area but not the first area.
- the reflection reduction layer is located between the transistor electrode and the substrate and has lower light reflectability than a material of the transistor electrode.
- the second area includes a transistor drain electrode, a transistor source electrode, a transistor gate electrode and a data line, and the reflection reduction layer entirely covers the second area.
- the reflection reduction layer is formed directly on an internal surface of the substrate.
- the reflection reduction layer and the transistor electrode are patterned together into a same shape.
- the sub-pixel includes a semiconductor layer and light shielding layer to shield the semiconductor layer from light, and the reflection reduction layer is formed on a surface of the light shielding layer.
- the second area includes a data line
- the reflection reduction layer is located between the data line and the substrate and has lower light reflectability than a material of the data line.
- FIG. 1 schematically shows configuration of an organic light emitting display according to an exemplary embodiment of the invention
- FIG. 2 shows an example of circuit configuration of a subpixel
- FIG. 3 illustrates a comparison between a related art organic light emitting display and an organic light emitting display according to an exemplary embodiment of the invention
- FIGS. 4 and 5 are a plane view and a cross-sectional view of a subpixel of a related art organic light emitting display
- FIGS. 6 and 7 are a plane view and a cross-sectional view of a subpixel of an organic light emitting display according to an exemplary embodiment of the invention.
- FIGS. 8 and 9 are a plane view and a cross-sectional view of a subpixel of an organic light emitting display according to another exemplary embodiment of the invention.
- FIG. 10 shows a first example of a reflection reduction layer
- FIG. 11 shows a second example of a reflection reduction layer
- FIG. 12 shows a third example of a reflection reduction layer
- FIG. 13 shows a first example of a structure including a reflection reduction layer
- FIG. 14 shows various examples of a transistor included in a subpixel.
- FIGS. 1 to 14 Exemplary embodiments of the invention will be described with reference to FIGS. 1 to 14 .
- FIG. 1 schematically shows configuration of an organic light emitting display according to an exemplary embodiment of the invention.
- FIG. 2 shows an example of circuit configuration of a subpixel.
- FIG. 3 illustrates a comparison between a related art organic light emitting display and an organic light emitting display according to an exemplary embodiment of the invention.
- an organic light emitting display includes an image processing unit 110 , a timing controller 120 , a data driver 130 , a gate driver 140 , and a display panel 150 .
- the image processing unit 110 outputs a data signal DATA received from the outside, a data enable signal DE, and the like.
- the image processing unit 110 may output at least one of a vertical sync signal, a horizontal sync signal, and a clock signal, in addition to the data enable signal DE.
- the signals are not shown and are omitted in the embodiment of the invention for the sake of brevity and ease of reading.
- the timing controller 120 receives the data signal DATA along with the data enable signal DE or a driving signal including the vertical sync signal, the horizontal sync signal, and the clock signal from the image processing unit 110 .
- the timing controller 120 outputs a gate timing control signal GDC for controlling timing of the gate driver 140 and a data timing control signal DDC for controlling timing of the data driver 130 based on the received signals.
- the data driver 130 samples and latches the data signal DATA received from the timing controller 120 in response to the data timing control signal DDC received from the timing controller 120 , converts the latched data signal DATA into a gamma reference voltage, and outputs the gamma reference voltage.
- the data driver 130 outputs the data signal DATA through data lines DL 1 to DLn.
- the data driver 130 is configured as an integrated circuit (IC) type.
- the gate driver 140 outputs a gate signal while shifting a level of a gate voltage in response to the gate timing control signal GDC received from the timing controller 120 .
- the gate driver 140 outputs the gate signal through gate lines GL 1 to GLm.
- the gate driver 140 is configured as an integrated circuit (IC) type or is formed on the display panel in a gate in panel (GIP) type.
- the display panel 150 displays an image corresponding to the data signal DATA and the gate signal respectively supplied from the data driver 130 and the gate driver 140 .
- the display panel 150 includes subpixels SP displaying the image.
- the subpixel may be configured as a top emission type, a bottom emission type, or a dual emission type depending on its structure.
- the subpixels SP may include red subpixels, green subpixels, and blue subpixels, or may include white subpixels, red subpixels, green subpixels, and blue subpixels.
- the subpixels SP may have one or more emission areas depending on their emission characteristics.
- each subpixel SP includes a switching transistor SW, a driving transistor DR, a capacitor Cst, a compensation circuit CC, and an organic light emitting diode OLED.
- the organic light emitting diode OLED operates, so that it emits light depending on a driving current formed by the driving transistor DR.
- the switching transistor SW performs a switching operation, so that the data signal received through a first data line DL 1 is stored in the capacitor Cst as a data voltage in response to the gate signal received through a first gate line GL 1 .
- the driving transistor DR operates so that the driving current flows between a first power line VDD and a second power line GND depending on the data voltage stored in the capacitor Cst.
- the compensation circuit CC is a circuit for compensating for a threshold voltage of the driving transistor DR.
- the compensation circuit CC includes at least one transistor and at least one capacitor.
- the compensation circuit CC may have various configurations depending on a compensation method, and a further description thereof may be briefly made or may be entirely omitted.
- FIG. 2 shows that the compensation circuit CC is included in one subpixel. However, when the subject of compensation (for example, the data driver 130 ) is positioned outside the subpixel, the compensation circuit CC may be omitted.
- the subpixel generally has a 2T (transistor) 1C (capacitor) structure including the switching transistor SW, the driving transistor DR, the capacitor Cst, and the organic light emitting diode OLED. If the compensation circuit CC is added, the subpixel may have a 3T1C structure, 4T2C structure, 5T2C structure, etc.
- the display quality (visibility, luminance, etc.) of the organic light emitting display may be reduced due to the incidence of ambient light.
- the related art limits reflection characteristic of ambient light by attaching a circular polarizer 160 for improving the display quality of an image IMG to the display panel 150 .
- the embodiment of the invention uses a reflection reduction layer instead of the circular polarizer for improving the display quality of the image IMG.
- the embodiment of the invention limits reflection characteristic of ambient light using the reflection reduction layer included in the display panel 150 .
- the reflection reduction layer may be formed inside or outside the display panel 150 .
- the reflection reduction layer may be formed of a binary compound such as metal oxide, ITO, IZO, IGZO, CuOx, and AlOx, alloy oxide including the binary compound, and alloy nitride including the binary compound. It is preferable, but not required, that the reflection reduction layer is formed inside the display panel 150 for convenience of the manufacturing process.
- a related art method and a method according to the embodiment of the invention for solving the problem resulting from the incidence of ambient light are described below through the comparison between them.
- FIGS. 4 and 5 are a plane view and a cross-sectional view of a subpixel of a related art organic light emitting display.
- FIGS. 6 and 7 are a plane view and a cross-sectional view of the subpixel of the organic light emitting display according to the embodiment of the invention.
- FIGS. 8 and 9 are a plane view and a cross-sectional view of a subpixel of an organic light emitting display according to another exemplary embodiment of the invention.
- the subpixel of the related art organic light emitting display is defined by a data line DL 1 , a gate line, etc.
- the subpixel includes an opening area, in which a lower electrode 161 , etc. are formed, and a non-opening area, in which the data line DL 1 , the gate line, a switching transistor SW, a capacitor (not shown), a driving transistor DR, etc. are formed.
- the opening area corresponds to an emission area, in which light is emitted
- the non-opening area corresponds to a non-emission area, in which light is not emitted. Because the electrodes or the lines formed in the non-opening area are generally used to transfer various signals or electric power, they have more excellent electric characteristic, lower resistance, and higher reflectance than the electrodes or the lines formed in the opening area.
- the related art uses the simple method for attaching the circular polarizer 160 to an external surface (or a display surface) of a lower substrate 150 a of the display panel 150 , so as to limit the reflection characteristic of the ambient light on the entire display surface of the display panel 150 .
- the circular polarizer 160 When the circular polarizer 160 is attached to the external surface of the display panel 150 as in the related art, the circular polarizer 160 reduces a reflectance of the non-opening area and thus can improve the display quality of the image IMG. However, it is difficult to prevent a luminance reduction in the opening area.
- the subpixel of the organic light emitting display according to the embodiment of the invention is defined by a data line DL 1 , a gate line, etc.
- the subpixel includes an opening area, in which a lower electrode 161 , etc. are formed, and a non-opening area, in which the data line DL 1 , the gate line, a switching transistor SW, a driving transistor DR, etc. are formed.
- the opening area corresponds to an emission area, in which light is emitted
- the non-opening area corresponds to a non-emission area, in which light is not emitted. Because the electrodes or the lines formed in the non-opening area are generally used to transfer various signals or electric power, they have more excellent electric characteristic, lower resistance, and higher reflectance than the electrodes or the lines formed in the opening area.
- a reflection reduction layer 151 is formed directly on an internal surface of a lower substrate 150 a of the display panel 150 and is patterned correspondingly to the non-opening area of the display panel 150 .
- the reflection reduction layer 151 is described in detail below based on a cross section of the driving transistor DR.
- the reflection reduction layer 151 is formed on the entire internal surface of the lower substrate 150 a and is patterned such that the reflection reduction layer 151 only covers the non-opening area of the display panel 150 .
- the reflection reduction layer 151 includes at least two layers.
- a gate electrode 152 is formed on the reflection reduction layer 151 and is patterned.
- a first insulating layer 153 is formed on the internal surface of the lower substrate 150 a and covers the gate electrode 152 .
- a semiconductor layer 154 is formed on the first insulating layer 153 and is patterned.
- an etch stopper layer 155 is formed on the semiconductor layer 154 and is patterned to expose a source region and a drain region.
- a source electrode 156 and a drain electrode 157 are formed on the etch stopper layer 155 and are patterned.
- the gate electrode 152 , the source electrode 156 , and the drain electrode 157 may be formed of a metal material such as Cu, Al, Au, Ag, Ti, Mo, W, Ta, and at least one alloy containing the same.
- An element of the alloy may be selected among Ca, Mg, Zn, Mn, Ti, Mo, Ni, Nd, Zr, Cd, Au, Ag, Co, Fe, Rh, In, Ta, Hf, W, and Cr.
- the semiconductor layer 154 may be formed of Si-based material, oxide-based material, graphene-based material containing carbon nanotube (CNT), nitride-based material, and/or organic semiconductor-based material.
- the reflection reduction layer 151 is made from a material that absorbs light and may appear black in color. Importantly, the reflection reduction layer 151 is made from a material that absorbs more light than the metal components within the non-opening area (e.g., gate electrode 152 , source electrode 156 , drain electrode 157 , etc.). This results in a reflection reduction layer 151 having lower light reflectability than the metal components within the non-opening area.
- the metal components within the non-opening area e.g., gate electrode 152 , source electrode 156 , drain electrode 157 , etc.
- the reflection reduction layer 151 When the reflection reduction layer 151 is formed on the internal surface of the lower substrate 150 a as in the embodiment of the invention, the reflection reduction layer 151 entirely covers the non-opening area to reduce reflections.
- the reflection reduction layer 151 does not cover the opening area. Therefore, the circular polarizer is omitted in the embodiment of the invention. It is preferable, but not required, that an area occupied by the reflection reduction layer 151 when patterning the reflection reduction layer 151 is larger than the entire area occupied by the electrodes or the lines positioned in the non-opening area.
- the area occupied by the reflection reduction layer 151 may be the entire area of the subpixel except for the opening area from the subpixel.
- the embodiment of the invention is not limited thereto.
- the area occupied by the reflection reduction layer 151 may be equal to the entire area occupied by the electrodes or the lines positioned in the non-opening area.
- the embodiment of the invention forms the reflection reduction layer 151 on the internal surface of the lower substrate 150 a corresponding to the non-opening area, thereby limiting reflection of ambient light in the non-opening area and also preventing luminance reduction in the opening area.
- the subpixel of the organic light emitting display is defined by a data line DL 1 , a gate line, etc.
- the subpixel includes an opening area, in which a lower electrode 161 , etc. are formed, and a non-opening area, in which the data line DL 1 , the gate line, a switching transistor SW, a capacitor (not shown), a driving transistor DR, etc. are formed.
- the opening area is different and separate from the non-opening area.
- the opening area corresponds to an emission area, in which light is emitted
- the non-opening area corresponds to a non-emission area, in which light is not emitted. Because the electrodes or the lines formed in the non-opening area are generally used to transfer various signals or electric power, they have better electric characteristics, lower resistance, and higher reflectance than the electrodes or the lines formed in the opening area.
- the embodiment of the invention is configured so that a reflection reduction layer is included in an electrode material when the data line DL 1 , the gate line, the switching transistor SW, the driving transistor DR, a gate electrode, a source electrode, and a drain electrode are formed in the non-opening area.
- the reflection reduction layer is described in detail below based by reference to a cross section of the driving transistor DR.
- the reflection reduction layer may also be considered a separate layer than is patterned into the same shape as the electrodes.
- a gate electrode 152 including a reflection reduction layer is formed on an internal surface of a lower substrate 150 a and is patterned.
- a first insulating layer 153 is formed on the internal surface of the lower substrate 150 a and covers the gate electrode 152 .
- a semiconductor layer 154 is formed on the first insulating layer 153 and is patterned.
- an etch stopper layer 155 is formed on the semiconductor layer 154 and is patterned to expose a source region and a drain region.
- a source electrode 156 including the reflection reduction layer and a drain electrode 157 including the reflection reduction layer are formed on the etch stopper layer 155 and are patterned.
- the reflection reduction layer When the reflection reduction layer is included in the electrode material in the formation of the data line DL 1 , the gate line, the switching transistor SW, and the driving transistor DR as in the embodiment of the invention, the reflection reduction layer covers reflective components in the non-opening area but does not cover the opening area. Therefore, the circular polarizer is omitted in the embodiment of the invention.
- the electrode material includes at least two layers.
- the gate electrode 152 includes a non-reflection reduction layer (indicating a metal layer having a reflectance greater than the reflection reduction layer or an insulating layer capable of absorbing the ambient light) and the reflection reduction layer.
- a non-reflection reduction layer indicating a metal layer having a reflectance greater than the reflection reduction layer or an insulating layer capable of absorbing the ambient light
- the reflection reduction layer occupies the non-reflection reduction layer.
- it is preferable, but not required, that the reflection reduction layer is closer to the ambient light than the non-reflection reduction layer. The reason is because the reflectance of the reflection reduction layer is less than the reflectance of the non-reflection reduction layer.
- the embodiment of the invention includes the reflection reduction layer in structures, such as the electrodes and the lines, positioned in the non-opening area, thereby limiting the reflection of ambient light in the non-opening area and also preventing luminance reduction in the opening area.
- the reflection reduction layer or the structure including the reflection reduction layer is described below.
- FIG. 10 shows a first example of the reflection reduction layer.
- FIG. 11 shows a second example of the reflection reduction layer.
- FIG. 12 shows a third example of the reflection reduction layer.
- FIG. 13 shows a first example of the structure including the reflection reduction layer.
- FIG. 14 shows various examples of the transistor included in the subpixel.
- the reflection reduction layer 151 formed on the internal surface of the lower substrate 150 a may have a two-layered structure.
- the reflection reduction layer 151 prevents the ambient light from being incident on the lower substrate 150 a and also prevents the reflection of light.
- At least one of a first layer 151 a and a second layer 151 b of the reflection reduction layer 151 may be formed of a reflection reduction material depending on the material of the layer formed on the reflection reduction layer 151 .
- both the first layer 151 a and the second layer 151 b may be formed of the reflection reduction material.
- the second layer 151 b may be formed of a buffer layer.
- the reflection reduction layer 151 formed on the internal surface of the lower substrate 150 a may have a three-layered structure.
- the reflection reduction layer 151 prevents the ambient light from being incident on the lower substrate 150 a and also prevents the reflection of light.
- At least one of a first layer 151 a, a second layer 151 b, and a third layer 151 c of the reflection reduction layer 151 may be formed of a reflection reduction material depending on the material of the layer formed on the reflection reduction layer 151 .
- all of the first to third layers 151 a to 151 c may be formed of the reflection reduction material.
- the third layer 151 c may be formed of a buffer layer.
- the reflection reduction layer 151 formed on the internal surface of the lower substrate 150 a may have a four-layered structure.
- the reflection reduction layer 151 prevents the reflection of ambient light.
- At least one of a first layer 151 a, a second layer 151 b, a third layer 151 c, and a fourth layer 151 d of the reflection reduction layer 151 may be formed of a reflection reduction material depending on the material of the layer formed on the reflection reduction layer 151 .
- all of the first to fourth layers 151 a to 151 d may be formed of the reflection reduction material.
- the first layer 151 a and the fourth layer 151 d may be formed of a buffer layer.
- the reflection reduction layer 151 may include N sub-layers, where N is an integer equal to or greater than 2. All of the N sub-layers constituting the reflection reduction layer 151 may be formed of the reflection reduction material, or at least one of the N sub-layers may be formed of the buffer layer.
- the gate electrode 152 and the drain electrode 157 may have a multi-layered structure including the reflection reduction layer.
- the gate electrode 152 and the drain electrode 157 each include the reflection reduction layer and the non-reflection reduction layer.
- the reflection reduction layer prevents the ambient light from being incident on the lower substrate 150 a and also prevents the reflection of light.
- the reflection reduction layers may also be considered to be separate from the electrodes themselves.
- a first layer 152 a and a second layer 152 b of the gate electrode 152 may be formed of the reflection reduction material. Hence, the first layer 152 a and the second layer 152 b corresponding to the reflection reduction layer is closer to the ambient light than a third layer 152 c corresponding to the non-reflection reduction layer.
- a first layer 157 a and a second layer 157 b of the drain electrode 157 may be formed of the reflection reduction material. Hence, the first layer 157 a and the second layer 157 b corresponding to the reflection reduction layer is closer to the ambient light than a third layer 157 c corresponding to the non-reflection reduction layer.
- the gate electrode 152 and the drain electrode 157 may have the same stack structure (for example, a three-layered structure) including the reflection reduction material. Further, the gate electrode 152 and the drain electrode 157 may have different stack structures each including the reflection reduction material. For example, the gate electrode 152 may have a three-layered structure, and the drain electrode 157 may have a four-layered structure.
- the gate electrode 152 and the drain electrode 157 (including the source electrode) have the multi-layered structure including the reflection reduction layer, a separate process for forming the reflection reduction layer may be omitted.
- the reflection reduction material contained in the reflection reduction layer or in the structures including the reflection reduction layer may be selected from metal or metal oxide such as ITO and MoTi, and the non-reflection reduction material may be selected from an insulating material such as SiOx and SiNx.
- the first layer 151 a may be formed of SiO 2
- the second layer 151 b may be formed of MoTi
- the third layer 151 c may be formed of ITO
- the fourth layer 151 d may be formed of SiO 2
- the first layer 152 a may be formed of ITO
- the second layer 152 b may be formed of MoTi
- the third layer 152 c may be formed of Cu.
- the layers constituting the reflection reduction layer or the structure including the reflection reduction layer may have different refractive indexes, so as to reduce the reflectance.
- layers positioned on and under a middle layer of the three or more layers may be formed of the same material and may have the same refractive index.
- the reflection reduction layer or the structures including the reflection reduction layer may further include metal, metal oxide, or metal nitride (for example, MN and TiAlN) having a different refractive index.
- the reflection reduction layer or the structures including the reflection reduction layer may have various structures including metal layer/insulating layer/metal layer, metal layer/metal oxide layer/metal layer, and insulating layer/first metal layer/second metal layer/insulating layer.
- the transistor according to the embodiment of the invention may have an inverted staggered back channel etched (BCE) structure shown in (b) of FIG. 14 or a coplanar structure shown in (c) of FIG. 14 .
- BCE back channel etched
- ‘G’ denotes the gate electrode
- ‘S’ denotes the source electrode
- ‘D’ denotes the drain electrode
- ‘A’ denotes the semiconductor layer.
- the transistor having the coplanar structure shown in (c) of FIG. 14 may include a light shielding layer formed directly on the internal surface of the substrate.
- the light shielding layer shields light incident on the semiconductor layer of the transistor.
- the light shielding layer may have an area corresponding to an area of the semiconductor layer or may have the area larger than the area of the semiconductor layer. In this instance, the light shielding layer may be formed in a mesh shape or an island shape.
- the reflection reduction layer may be further formed on an upper surface or a lower surface of the light shielding layer. Therefore, the reflection reduction layer may be formed as an individual layer or may be included in another layer.
- the reflection reduction layer may be between the lower substrate 150 a and at least a portion of the subpixel components (e.g., gate electrode 152 , drain electrode 157 , source electrode 156 , data line DL 1 , etc.)
- the reflection reduction layer has lower reflective properties than a material of these components and reduces the overall amount of light reflected by the display device
Abstract
Description
- This application claims the benefit of Korean Patent Application No. 10-2014-0035329 filed on Mar. 26, 2014, which is incorporated herein by reference for all purposes as if fully set forth herein.
- 1. Field of the Invention
- Embodiments of the invention relate to an organic light emitting display.
- 2. Discussion of the Related Art
- An organic light emitting element used in an organic light emitting display is a self-emitting element having a light emitting layer between two electrodes. The organic light emitting element receives electrons and holes from a cathode serving as an electron injection electrode and an anode serving as a hole injection electrode and injects the electrons and the holes into the light emitting layer. The injected electrons and holes are combined to form an exciton. The organic light emitting element emits light when the exciton drops from an excited state to a ground state.
- The organic light emitting display forms a display panel using the organic light emitting element. The display panel may be classified into a top emission type, a bottom emission type, and a dual emission type depending on an emission direction of light. Further, the display panel may be classified into a passive matrix type and an active matrix type depending on a driving method.
- The display quality (visibility, luminance, etc.) of the organic light emitting display may be reduced due to the incidence of ambient light. Hence, when the display panel of the organic light emitting display was manufactured in a related art, the related art limited incidence of the ambient light by attaching a circular polarizer to an external surface (or a display surface) of the display panel.
- However, when the circular polarizer was attached to the external surface of the display panel in the related art, a luminance of the display panel was reduced to about one half Further, an increase in the manufacturing cost was caused by the circular polarizer.
- In one aspect, there is an organic light emitting display comprising a display panel including subpixels and a driver configured to drive the display panel, wherein the display panel includes a reflection reduction layer, which is formed on an internal surface or an external surface of a substrate and is positioned correspondingly to a non-opening area defined in the substrate.
- In one embodiment an organic light emitting display comprises a substrate and a plurality of sub-pixels. Each sub-pixel has a first area for light emission; a second area including a transistor electrode, the second area being different than the first area; and a reflection reduction layer in the second area but not the first area. The reflection reduction layer is located between the transistor electrode and the substrate and has lower light reflectability than a material of the transistor electrode.
- In one embodiment, the second area includes a transistor drain electrode, a transistor source electrode, a transistor gate electrode and a data line, and the reflection reduction layer entirely covers the second area. In one embodiment, the reflection reduction layer is formed directly on an internal surface of the substrate. In one embodiment, the reflection reduction layer and the transistor electrode are patterned together into a same shape. In one embodiment, the sub-pixel includes a semiconductor layer and light shielding layer to shield the semiconductor layer from light, and the reflection reduction layer is formed on a surface of the light shielding layer.
- In another embodiment, the second area includes a data line, and the reflection reduction layer is located between the data line and the substrate and has lower light reflectability than a material of the data line.
- The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:
-
FIG. 1 schematically shows configuration of an organic light emitting display according to an exemplary embodiment of the invention; -
FIG. 2 shows an example of circuit configuration of a subpixel; -
FIG. 3 illustrates a comparison between a related art organic light emitting display and an organic light emitting display according to an exemplary embodiment of the invention; -
FIGS. 4 and 5 are a plane view and a cross-sectional view of a subpixel of a related art organic light emitting display; -
FIGS. 6 and 7 are a plane view and a cross-sectional view of a subpixel of an organic light emitting display according to an exemplary embodiment of the invention; -
FIGS. 8 and 9 are a plane view and a cross-sectional view of a subpixel of an organic light emitting display according to another exemplary embodiment of the invention; -
FIG. 10 shows a first example of a reflection reduction layer; -
FIG. 11 shows a second example of a reflection reduction layer; -
FIG. 12 shows a third example of a reflection reduction layer; -
FIG. 13 shows a first example of a structure including a reflection reduction layer; -
FIG. 14 shows various examples of a transistor included in a subpixel. - Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. It will be paid attention that detailed description of known arts will be omitted if it is determined that the arts can mislead the embodiments of the invention.
- Exemplary embodiments of the invention will be described with reference to
FIGS. 1 to 14 . -
FIG. 1 schematically shows configuration of an organic light emitting display according to an exemplary embodiment of the invention.FIG. 2 shows an example of circuit configuration of a subpixel.FIG. 3 illustrates a comparison between a related art organic light emitting display and an organic light emitting display according to an exemplary embodiment of the invention. - As shown in
FIG. 1 , an organic light emitting display according to an exemplary embodiment of the invention includes animage processing unit 110, atiming controller 120, adata driver 130, agate driver 140, and adisplay panel 150. - The
image processing unit 110 outputs a data signal DATA received from the outside, a data enable signal DE, and the like. Theimage processing unit 110 may output at least one of a vertical sync signal, a horizontal sync signal, and a clock signal, in addition to the data enable signal DE. However, the signals are not shown and are omitted in the embodiment of the invention for the sake of brevity and ease of reading. - The
timing controller 120 receives the data signal DATA along with the data enable signal DE or a driving signal including the vertical sync signal, the horizontal sync signal, and the clock signal from theimage processing unit 110. Thetiming controller 120 outputs a gate timing control signal GDC for controlling timing of thegate driver 140 and a data timing control signal DDC for controlling timing of thedata driver 130 based on the received signals. - The
data driver 130 samples and latches the data signal DATA received from thetiming controller 120 in response to the data timing control signal DDC received from thetiming controller 120, converts the latched data signal DATA into a gamma reference voltage, and outputs the gamma reference voltage. Thedata driver 130 outputs the data signal DATA through data lines DL1 to DLn. Thedata driver 130 is configured as an integrated circuit (IC) type. - The
gate driver 140 outputs a gate signal while shifting a level of a gate voltage in response to the gate timing control signal GDC received from thetiming controller 120. Thegate driver 140 outputs the gate signal through gate lines GL1 to GLm. Thegate driver 140 is configured as an integrated circuit (IC) type or is formed on the display panel in a gate in panel (GIP) type. - The
display panel 150 displays an image corresponding to the data signal DATA and the gate signal respectively supplied from thedata driver 130 and thegate driver 140. Thedisplay panel 150 includes subpixels SP displaying the image. - The subpixel may be configured as a top emission type, a bottom emission type, or a dual emission type depending on its structure. The subpixels SP may include red subpixels, green subpixels, and blue subpixels, or may include white subpixels, red subpixels, green subpixels, and blue subpixels. The subpixels SP may have one or more emission areas depending on their emission characteristics.
- As shown in
FIG. 2 , each subpixel SP includes a switching transistor SW, a driving transistor DR, a capacitor Cst, a compensation circuit CC, and an organic light emitting diode OLED. The organic light emitting diode OLED operates, so that it emits light depending on a driving current formed by the driving transistor DR. - The switching transistor SW performs a switching operation, so that the data signal received through a first data line DL1 is stored in the capacitor Cst as a data voltage in response to the gate signal received through a first gate line GL1. The driving transistor DR operates so that the driving current flows between a first power line VDD and a second power line GND depending on the data voltage stored in the capacitor Cst. The compensation circuit CC is a circuit for compensating for a threshold voltage of the driving transistor DR.
- The compensation circuit CC includes at least one transistor and at least one capacitor. The compensation circuit CC may have various configurations depending on a compensation method, and a further description thereof may be briefly made or may be entirely omitted.
-
FIG. 2 shows that the compensation circuit CC is included in one subpixel. However, when the subject of compensation (for example, the data driver 130) is positioned outside the subpixel, the compensation circuit CC may be omitted. The subpixel generally has a 2T (transistor) 1C (capacitor) structure including the switching transistor SW, the driving transistor DR, the capacitor Cst, and the organic light emitting diode OLED. If the compensation circuit CC is added, the subpixel may have a 3T1C structure, 4T2C structure, 5T2C structure, etc. - The display quality (visibility, luminance, etc.) of the organic light emitting display may be reduced due to the incidence of ambient light.
- As shown in (a) of
FIG. 3 , when adisplay panel 150 of an organic light emitting display is manufactured in a related art, the related art limits reflection characteristic of ambient light by attaching acircular polarizer 160 for improving the display quality of an image IMG to thedisplay panel 150. - As shown in (b) of
FIG. 3 , when thedisplay panel 150 of the organic light emitting display is manufactured in the embodiment of the invention, the embodiment of the invention uses a reflection reduction layer instead of the circular polarizer for improving the display quality of the image IMG. - More specifically, the embodiment of the invention limits reflection characteristic of ambient light using the reflection reduction layer included in the
display panel 150. The reflection reduction layer may be formed inside or outside thedisplay panel 150. The reflection reduction layer may be formed of a binary compound such as metal oxide, ITO, IZO, IGZO, CuOx, and AlOx, alloy oxide including the binary compound, and alloy nitride including the binary compound. It is preferable, but not required, that the reflection reduction layer is formed inside thedisplay panel 150 for convenience of the manufacturing process. - A related art method and a method according to the embodiment of the invention for solving the problem resulting from the incidence of ambient light are described below through the comparison between them.
-
FIGS. 4 and 5 are a plane view and a cross-sectional view of a subpixel of a related art organic light emitting display.FIGS. 6 and 7 are a plane view and a cross-sectional view of the subpixel of the organic light emitting display according to the embodiment of the invention.FIGS. 8 and 9 are a plane view and a cross-sectional view of a subpixel of an organic light emitting display according to another exemplary embodiment of the invention. - As shown in
FIGS. 4 and 5 , the subpixel of the related art organic light emitting display is defined by a data line DL1, a gate line, etc. The subpixel includes an opening area, in which alower electrode 161, etc. are formed, and a non-opening area, in which the data line DL1, the gate line, a switching transistor SW, a capacitor (not shown), a driving transistor DR, etc. are formed. - The opening area corresponds to an emission area, in which light is emitted, and the non-opening area corresponds to a non-emission area, in which light is not emitted. Because the electrodes or the lines formed in the non-opening area are generally used to transfer various signals or electric power, they have more excellent electric characteristic, lower resistance, and higher reflectance than the electrodes or the lines formed in the opening area.
- More specifically, the related art uses the simple method for attaching the
circular polarizer 160 to an external surface (or a display surface) of alower substrate 150 a of thedisplay panel 150, so as to limit the reflection characteristic of the ambient light on the entire display surface of thedisplay panel 150. When thecircular polarizer 160 is attached to the external surface of thedisplay panel 150 as in the related art, thecircular polarizer 160 reduces a reflectance of the non-opening area and thus can improve the display quality of the image IMG. However, it is difficult to prevent a luminance reduction in the opening area. - As shown in
FIGS. 6 and 7 , the subpixel of the organic light emitting display according to the embodiment of the invention is defined by a data line DL1, a gate line, etc. The subpixel includes an opening area, in which alower electrode 161, etc. are formed, and a non-opening area, in which the data line DL1, the gate line, a switching transistor SW, a driving transistor DR, etc. are formed. - The opening area corresponds to an emission area, in which light is emitted, and the non-opening area corresponds to a non-emission area, in which light is not emitted. Because the electrodes or the lines formed in the non-opening area are generally used to transfer various signals or electric power, they have more excellent electric characteristic, lower resistance, and higher reflectance than the electrodes or the lines formed in the opening area.
- In the embodiment of the invention, a
reflection reduction layer 151 is formed directly on an internal surface of alower substrate 150 a of thedisplay panel 150 and is patterned correspondingly to the non-opening area of thedisplay panel 150. Thereflection reduction layer 151 is described in detail below based on a cross section of the driving transistor DR. - More specifically, the
reflection reduction layer 151 is formed on the entire internal surface of thelower substrate 150 a and is patterned such that thereflection reduction layer 151 only covers the non-opening area of thedisplay panel 150. In this instance, thereflection reduction layer 151 includes at least two layers. Next, agate electrode 152 is formed on thereflection reduction layer 151 and is patterned. Next, a first insulatinglayer 153 is formed on the internal surface of thelower substrate 150 a and covers thegate electrode 152. Next, asemiconductor layer 154 is formed on the first insulatinglayer 153 and is patterned. Next, anetch stopper layer 155 is formed on thesemiconductor layer 154 and is patterned to expose a source region and a drain region. Asource electrode 156 and adrain electrode 157 are formed on theetch stopper layer 155 and are patterned. - The
gate electrode 152, thesource electrode 156, and thedrain electrode 157 may be formed of a metal material such as Cu, Al, Au, Ag, Ti, Mo, W, Ta, and at least one alloy containing the same. An element of the alloy may be selected among Ca, Mg, Zn, Mn, Ti, Mo, Ni, Nd, Zr, Cd, Au, Ag, Co, Fe, Rh, In, Ta, Hf, W, and Cr. Thesemiconductor layer 154 may be formed of Si-based material, oxide-based material, graphene-based material containing carbon nanotube (CNT), nitride-based material, and/or organic semiconductor-based material. - The
reflection reduction layer 151 is made from a material that absorbs light and may appear black in color. Importantly, thereflection reduction layer 151 is made from a material that absorbs more light than the metal components within the non-opening area (e.g.,gate electrode 152,source electrode 156,drain electrode 157, etc.). This results in areflection reduction layer 151 having lower light reflectability than the metal components within the non-opening area. - When the
reflection reduction layer 151 is formed on the internal surface of thelower substrate 150 a as in the embodiment of the invention, thereflection reduction layer 151 entirely covers the non-opening area to reduce reflections. Thereflection reduction layer 151 does not cover the opening area. Therefore, the circular polarizer is omitted in the embodiment of the invention. It is preferable, but not required, that an area occupied by thereflection reduction layer 151 when patterning thereflection reduction layer 151 is larger than the entire area occupied by the electrodes or the lines positioned in the non-opening area. - The reason is because a reflectance of the ambient light incident from the upper, lower, left, and right sides of the organic light emitting display may be considered. Therefore, the area occupied by the
reflection reduction layer 151 may be the entire area of the subpixel except for the opening area from the subpixel. However, the embodiment of the invention is not limited thereto. For example, the area occupied by thereflection reduction layer 151 may be equal to the entire area occupied by the electrodes or the lines positioned in the non-opening area. - Accordingly, the embodiment of the invention forms the
reflection reduction layer 151 on the internal surface of thelower substrate 150 a corresponding to the non-opening area, thereby limiting reflection of ambient light in the non-opening area and also preventing luminance reduction in the opening area. - As shown in
FIGS. 8 and 9 , the subpixel of the organic light emitting display according to another embodiment of the invention is defined by a data line DL1, a gate line, etc. The subpixel includes an opening area, in which alower electrode 161, etc. are formed, and a non-opening area, in which the data line DL1, the gate line, a switching transistor SW, a capacitor (not shown), a driving transistor DR, etc. are formed. The opening area is different and separate from the non-opening area. - The opening area corresponds to an emission area, in which light is emitted, and the non-opening area corresponds to a non-emission area, in which light is not emitted. Because the electrodes or the lines formed in the non-opening area are generally used to transfer various signals or electric power, they have better electric characteristics, lower resistance, and higher reflectance than the electrodes or the lines formed in the opening area.
- The embodiment of the invention is configured so that a reflection reduction layer is included in an electrode material when the data line DL1, the gate line, the switching transistor SW, the driving transistor DR, a gate electrode, a source electrode, and a drain electrode are formed in the non-opening area. The reflection reduction layer is described in detail below based by reference to a cross section of the driving transistor DR. Although formed with the electrodes, the reflection reduction layer may also be considered a separate layer than is patterned into the same shape as the electrodes.
- More specifically, a
gate electrode 152 including a reflection reduction layer is formed on an internal surface of alower substrate 150 a and is patterned. Next, a first insulatinglayer 153 is formed on the internal surface of thelower substrate 150 a and covers thegate electrode 152. Next, asemiconductor layer 154 is formed on the first insulatinglayer 153 and is patterned. Next, anetch stopper layer 155 is formed on thesemiconductor layer 154 and is patterned to expose a source region and a drain region. Next, asource electrode 156 including the reflection reduction layer and adrain electrode 157 including the reflection reduction layer are formed on theetch stopper layer 155 and are patterned. - When the reflection reduction layer is included in the electrode material in the formation of the data line DL1, the gate line, the switching transistor SW, and the driving transistor DR as in the embodiment of the invention, the reflection reduction layer covers reflective components in the non-opening area but does not cover the opening area. Therefore, the circular polarizer is omitted in the embodiment of the invention.
- When the electrode material is configured so that it includes the reflection reduction layer, the electrode material includes at least two layers. For example, the
gate electrode 152 includes a non-reflection reduction layer (indicating a metal layer having a reflectance greater than the reflection reduction layer or an insulating layer capable of absorbing the ambient light) and the reflection reduction layer. When the ambient light is incident through thelower substrate 150 a, a first layer of thegate electrode 152 occupies the reflection reduction layer, and a second layer of thegate electrode 152 occupies the non-reflection reduction layer. As described above, it is preferable, but not required, that the reflection reduction layer is closer to the ambient light than the non-reflection reduction layer. The reason is because the reflectance of the reflection reduction layer is less than the reflectance of the non-reflection reduction layer. - Accordingly, the embodiment of the invention includes the reflection reduction layer in structures, such as the electrodes and the lines, positioned in the non-opening area, thereby limiting the reflection of ambient light in the non-opening area and also preventing luminance reduction in the opening area.
- The reflection reduction layer or the structure including the reflection reduction layer is described below.
-
FIG. 10 shows a first example of the reflection reduction layer.FIG. 11 shows a second example of the reflection reduction layer.FIG. 12 shows a third example of the reflection reduction layer.FIG. 13 shows a first example of the structure including the reflection reduction layer.FIG. 14 shows various examples of the transistor included in the subpixel. - As shown in
FIG. 10 , thereflection reduction layer 151 formed on the internal surface of thelower substrate 150 a may have a two-layered structure. Thereflection reduction layer 151 prevents the ambient light from being incident on thelower substrate 150 a and also prevents the reflection of light. - At least one of a
first layer 151 a and asecond layer 151 b of thereflection reduction layer 151 may be formed of a reflection reduction material depending on the material of the layer formed on thereflection reduction layer 151. Alternatively, both thefirst layer 151 a and thesecond layer 151 b may be formed of the reflection reduction material. For example, when thefirst layer 151 a is formed of the reflection reduction material, thesecond layer 151 b may be formed of a buffer layer. - As shown in
FIG. 11 , thereflection reduction layer 151 formed on the internal surface of thelower substrate 150 a may have a three-layered structure. Thereflection reduction layer 151 prevents the ambient light from being incident on thelower substrate 150 a and also prevents the reflection of light. - At least one of a
first layer 151 a, asecond layer 151 b, and athird layer 151 c of thereflection reduction layer 151 may be formed of a reflection reduction material depending on the material of the layer formed on thereflection reduction layer 151. Alternatively, all of the first tothird layers 151 a to 151 c may be formed of the reflection reduction material. For example, when thefirst layer 151 a and thesecond layer 151 b are formed of the reflection reduction material, thethird layer 151 c may be formed of a buffer layer. - As shown in
FIG. 12 , thereflection reduction layer 151 formed on the internal surface of thelower substrate 150 a may have a four-layered structure. Thereflection reduction layer 151 prevents the reflection of ambient light. - At least one of a
first layer 151 a, asecond layer 151 b, athird layer 151 c, and afourth layer 151 d of thereflection reduction layer 151 may be formed of a reflection reduction material depending on the material of the layer formed on thereflection reduction layer 151. Alternatively, all of the first tofourth layers 151 a to 151 d may be formed of the reflection reduction material. For example, when thesecond layer 151 b and thethird layer 151 c are formed of the reflection reduction material, thefirst layer 151 a and thefourth layer 151 d may be formed of a buffer layer. - As can be seen from the above examples, the
reflection reduction layer 151 may include N sub-layers, where N is an integer equal to or greater than 2. All of the N sub-layers constituting thereflection reduction layer 151 may be formed of the reflection reduction material, or at least one of the N sub-layers may be formed of the buffer layer. - As shown in
FIG. 13 , thegate electrode 152 and the drain electrode 157 (including the source electrode) may have a multi-layered structure including the reflection reduction layer. Thegate electrode 152 and thedrain electrode 157 each include the reflection reduction layer and the non-reflection reduction layer. The reflection reduction layer prevents the ambient light from being incident on thelower substrate 150 a and also prevents the reflection of light. As explained, the reflection reduction layers may also be considered to be separate from the electrodes themselves. - A
first layer 152 a and a second layer 152 b of thegate electrode 152 may be formed of the reflection reduction material. Hence, thefirst layer 152 a and the second layer 152 b corresponding to the reflection reduction layer is closer to the ambient light than athird layer 152 c corresponding to the non-reflection reduction layer. Afirst layer 157 a and asecond layer 157 b of thedrain electrode 157 may be formed of the reflection reduction material. Hence, thefirst layer 157 a and thesecond layer 157 b corresponding to the reflection reduction layer is closer to the ambient light than athird layer 157 c corresponding to the non-reflection reduction layer. - The
gate electrode 152 and thedrain electrode 157 may have the same stack structure (for example, a three-layered structure) including the reflection reduction material. Further, thegate electrode 152 and thedrain electrode 157 may have different stack structures each including the reflection reduction material. For example, thegate electrode 152 may have a three-layered structure, and thedrain electrode 157 may have a four-layered structure. - As can be seen from the above examples, when the
gate electrode 152 and the drain electrode 157 (including the source electrode) have the multi-layered structure including the reflection reduction layer, a separate process for forming the reflection reduction layer may be omitted. - As described above with reference to
FIGS. 10 to 13 , the reflection reduction material contained in the reflection reduction layer or in the structures including the reflection reduction layer may be selected from metal or metal oxide such as ITO and MoTi, and the non-reflection reduction material may be selected from an insulating material such as SiOx and SiNx. - For example, in the
reflection reduction layer 151 shown inFIG. 12 , thefirst layer 151 a may be formed of SiO2, thesecond layer 151 b may be formed of MoTi, thethird layer 151 c may be formed of ITO, and thefourth layer 151 d may be formed of SiO2. Further, in thegate electrode 152 shown inFIG. 13 , thefirst layer 152 a may be formed of ITO, the second layer 152 b may be formed of MoTi, and thethird layer 152 c may be formed of Cu. - Furthermore, the layers constituting the reflection reduction layer or the structure including the reflection reduction layer may have different refractive indexes, so as to reduce the reflectance. When the reflection reduction layer or the structure including the reflection reduction layer has three or more layers, layers positioned on and under a middle layer of the three or more layers may be formed of the same material and may have the same refractive index. The reflection reduction layer or the structures including the reflection reduction layer may further include metal, metal oxide, or metal nitride (for example, MN and TiAlN) having a different refractive index. In addition, the reflection reduction layer or the structures including the reflection reduction layer may have various structures including metal layer/insulating layer/metal layer, metal layer/metal oxide layer/metal layer, and insulating layer/first metal layer/second metal layer/insulating layer.
- As shown in (a) of
FIG. 14 , so far, the embodiment of the invention using a transistor having an inverted staggered etch stopper (ES) structure has been described. However, the transistor according to the embodiment of the invention may have an inverted staggered back channel etched (BCE) structure shown in (b) ofFIG. 14 or a coplanar structure shown in (c) ofFIG. 14 . InFIG. 14 , ‘G’ denotes the gate electrode, ‘S’ denotes the source electrode, ‘D’ denotes the drain electrode, and ‘A’ denotes the semiconductor layer. - The transistor having the coplanar structure shown in (c) of
FIG. 14 may include a light shielding layer formed directly on the internal surface of the substrate. The light shielding layer shields light incident on the semiconductor layer of the transistor. The light shielding layer may have an area corresponding to an area of the semiconductor layer or may have the area larger than the area of the semiconductor layer. In this instance, the light shielding layer may be formed in a mesh shape or an island shape. - In the transistor of the coplanar structure including the light shielding layer, the reflection reduction layer may be further formed on an upper surface or a lower surface of the light shielding layer. Therefore, the reflection reduction layer may be formed as an individual layer or may be included in another layer.
- As described in the various embodiments, the reflection reduction layer may be between the
lower substrate 150 a and at least a portion of the subpixel components (e.g.,gate electrode 152,drain electrode 157,source electrode 156, data line DL1, etc.) The reflection reduction layer has lower reflective properties than a material of these components and reduces the overall amount of light reflected by the display device - Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20170125492A1 (en) * | 2015-10-30 | 2017-05-04 | Lg Display Co., Ltd. | Organic light emitting display device |
US10475872B2 (en) | 2015-10-23 | 2019-11-12 | Lg Display Co., Ltd. | Display device with light blocking layer and manufacturing method thereof |
CN110941115A (en) * | 2019-12-25 | 2020-03-31 | 深圳市华星光电半导体显示技术有限公司 | Low-reflection composite layer, manufacturing method thereof and application of low-reflection composite layer to array substrate |
US11545576B2 (en) | 2019-11-26 | 2023-01-03 | Tcl China Star Optoelectronics Technology Co., Ltd. | Display panel and electronic device |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR102383323B1 (en) * | 2015-10-30 | 2022-04-05 | 엘지디스플레이 주식회사 | Flexible organic light emitting display device |
CN109427998B (en) * | 2017-09-01 | 2020-01-14 | 京东方科技集团股份有限公司 | Cover plate for organic electroluminescent display device, manufacturing method thereof, organic electroluminescent display device and display equipment |
CN109119452A (en) * | 2018-09-18 | 2019-01-01 | 深圳市华星光电半导体显示技术有限公司 | Display panel and display device |
CN109656099B (en) * | 2018-11-07 | 2020-07-10 | 深圳市华星光电半导体显示技术有限公司 | Preparation method of anti-reflection array substrate and anti-reflection array substrate prepared by same |
KR102585813B1 (en) * | 2018-12-26 | 2023-10-06 | 엘지디스플레이 주식회사 | Organic Light Emitting Display Device |
CN110797381B (en) * | 2019-11-07 | 2022-09-09 | 武汉天马微电子有限公司 | Display panel and display device |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7795807B2 (en) * | 2005-11-10 | 2010-09-14 | Au Optronics Corp. | Organic light emitting display |
US20120097930A1 (en) * | 2010-10-25 | 2012-04-26 | Samsung Mobile Display Co., Ltd. | Organic light-emitting display apparatus and method of manufacturing the same |
US20130155860A1 (en) * | 2011-12-19 | 2013-06-20 | Electronics And Telecommunications Research Institute | Packet transmission device and method of transmitting packet |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB9803764D0 (en) * | 1998-02-23 | 1998-04-15 | Cambridge Display Tech Ltd | Display devices |
JP2001109404A (en) * | 1999-10-01 | 2001-04-20 | Sanyo Electric Co Ltd | El display device |
US6744198B2 (en) * | 2001-03-19 | 2004-06-01 | Seiko Epson Corporation | Method for manufacturing display device, display device, and electronic apparatus |
KR100472502B1 (en) * | 2001-12-26 | 2005-03-08 | 삼성에스디아이 주식회사 | Organic electro luminescence display device |
TWI340607B (en) * | 2005-08-12 | 2011-04-11 | Au Optronics Corp | Organic electroluminescent display panel and fabricating method thereof |
JP5476878B2 (en) * | 2009-09-14 | 2014-04-23 | カシオ計算機株式会社 | Manufacturing method of light emitting panel |
KR101125566B1 (en) * | 2009-11-30 | 2012-03-26 | 삼성모바일디스플레이주식회사 | Oanic Light Emitting Display Device and The Fabricating Method Of The Same |
KR20140023492A (en) * | 2012-08-16 | 2014-02-27 | 삼성코닝정밀소재 주식회사 | Sputtering target and organic light emitting diode display device including black matrix deposited by the same |
KR101983691B1 (en) * | 2012-08-17 | 2019-05-30 | 삼성디스플레이 주식회사 | Light blocking member and display panel including the same |
-
2014
- 2014-03-26 KR KR1020140035329A patent/KR102256083B1/en active IP Right Grant
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Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7795807B2 (en) * | 2005-11-10 | 2010-09-14 | Au Optronics Corp. | Organic light emitting display |
US20120097930A1 (en) * | 2010-10-25 | 2012-04-26 | Samsung Mobile Display Co., Ltd. | Organic light-emitting display apparatus and method of manufacturing the same |
US20130155860A1 (en) * | 2011-12-19 | 2013-06-20 | Electronics And Telecommunications Research Institute | Packet transmission device and method of transmitting packet |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10475872B2 (en) | 2015-10-23 | 2019-11-12 | Lg Display Co., Ltd. | Display device with light blocking layer and manufacturing method thereof |
US20170125492A1 (en) * | 2015-10-30 | 2017-05-04 | Lg Display Co., Ltd. | Organic light emitting display device |
US10103210B2 (en) * | 2015-10-30 | 2018-10-16 | Lg Display Co., Ltd. | Organic light emitting display device |
US11545576B2 (en) | 2019-11-26 | 2023-01-03 | Tcl China Star Optoelectronics Technology Co., Ltd. | Display panel and electronic device |
CN110941115A (en) * | 2019-12-25 | 2020-03-31 | 深圳市华星光电半导体显示技术有限公司 | Low-reflection composite layer, manufacturing method thereof and application of low-reflection composite layer to array substrate |
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EP2924758A1 (en) | 2015-09-30 |
CN104952901B (en) | 2018-08-31 |
CN104952901A (en) | 2015-09-30 |
US9165994B1 (en) | 2015-10-20 |
KR102256083B1 (en) | 2021-05-26 |
EP2924758B1 (en) | 2019-08-07 |
KR20150112101A (en) | 2015-10-07 |
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