US20170155095A1 - Display device and optical film - Google Patents
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- US20170155095A1 US20170155095A1 US14/954,933 US201514954933A US2017155095A1 US 20170155095 A1 US20170155095 A1 US 20170155095A1 US 201514954933 A US201514954933 A US 201514954933A US 2017155095 A1 US2017155095 A1 US 2017155095A1
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Images
Classifications
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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
- H10K59/80—Constructional details
- H10K59/8791—Arrangements for improving contrast, e.g. preventing reflection of ambient light
- H10K59/8792—Arrangements for improving contrast, e.g. preventing reflection of ambient light comprising light absorbing layers, e.g. black layers
-
- 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
-
- H01L51/5284—
-
- H01L51/5275—
-
- 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
- H10K50/858—Arrangements for extracting light from the devices comprising refractive means, e.g. lenses
-
- 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
- H10K59/80—Constructional details
- H10K59/875—Arrangements for extracting light from the devices
- H10K59/879—Arrangements for extracting light from the devices comprising refractive means, e.g. lenses
Definitions
- the disclosure relates to a display device and an optical film, and particularly relates to a display device and an optical film having a high ambient contrast ratio.
- a light emitting diode display is a display element utilizing the self-luminescent characteristics of light emitting materials to display.
- the luminescent structure of the light emitting diode display mainly includes a pair of electrodes and a light emitting layer. When a current flows through the light emitting layer via an anode and a cathode, electrons and holes are combined in the light emitting layer to generate excitons, so as to generate light beams of different colors based on material characteristics of the light emitting layer.
- the contrast ratio is one of the factors determining the display quality.
- stronger ambient light may result in a lower ambient contrast ratio, and the display quality of the display is thus affected.
- a light absorption layer is provided to absorb the ambient light.
- a portion of the light beams emitted by the light emitting layer may also be absorbed by the light absorption layer, thus making an output luminance inefficient.
- the disclosure provides a display device capable of providing a high output luminance and a high ambient contrast ratio under a circumstance that reflection of ambient light is controlled.
- An embodiment of the disclosure provides a display device including a substrate, a light absorption layer, an optical matching layer, a first transparent electrode, a light emitting layer, and a second transparent electrode.
- the light absorption layer is disposed on the substrate, and the optical matching layer is disposed on the light absorption layer.
- the first transparent electrode is disposed on the optical matching layer, the light emitting layer is disposed on the first transparent electrode, and the second transparent electrode is disposed on the light emitting layer.
- a display device including a substrate, a light absorption layer, a transflective electrode, a light emitting layer, and a transparent electrode.
- the light absorption layer is disposed on the substrate.
- the transflective electrode is disposed on the light absorption layer, the light emitting layer is disposed on the transflective electrode, and the transparent electrode is disposed on the light emitting layer.
- a transmittance of the transflective electrode is in a range from 40% to 80%.
- An embodiment of the disclosure provides a display device, including a substrate, a first transparent electrode, a light emitting layer, a second transparent electrode, an anti-reflection layer, and a light absorption layer.
- the first transparent electrode is disposed on the substrate.
- the light emitting layer is disposed on the first transparent electrode.
- the second transparent electrode is disposed on the light emitting layer.
- the anti-reflection layer is disposed on the second transparent electrode.
- the light absorption layer is disposed on the anti-reflection layer.
- An embodiment of the disclosure provides a display device including a substrate, a first anti-reflection layer, a first transparent electrode, a light emitting layer, a second transparent electrode, and a light absorption layer.
- the first anti-reflection layer is disposed on the substrate.
- the first transparent electrode is disposed on the first anti-reflection layer.
- the light emitting layer is disposed on the first transparent electrode.
- the second transparent electrode is disposed on the light emitting layer.
- the light absorption layer is disposed on the second transparent electrode.
- FIG. 1 is a view illustrating a display device according to an embodiment of the disclosure.
- FIGS. 2A to 2C are views illustrating simulations on light emitting intensities of the display device of FIG. 1 .
- FIG. 3 is a view illustrating a relation between wavelengths and light emitting densities of display devices according to two embodiments of the disclosure.
- FIG. 4 is a view illustrating a display device according to another embodiment of the disclosure.
- FIG. 5 is a view illustrating a display device according to another embodiment of the disclosure.
- FIG. 6 is a view illustrating a display device according to another embodiment of the disclosure.
- FIG. 7 is a view illustrating a display device according to an embodiment of the disclosure.
- FIGS. 8A and 8B are views illustrating optical simulations on the display device of FIG. 7 .
- FIG. 9 is a view illustrating a display device according to another embodiment of the disclosure.
- FIG. 10 is a view illustrating a display device according to another embodiment of the disclosure.
- FIG. 11 is a view illustrating a display device according to another embodiment of the disclosure.
- FIG. 12 is a view illustrating a display device according to another embodiment of the disclosure.
- FIG. 13 is a view illustrating an optical film according to an embodiment of the disclosure.
- FIG. 14 is a schematic view illustrating applying the optical film of FIG. 13 in a display device.
- FIG. 15 is a view illustrating an optical film according to another embodiment of the disclosure.
- FIG. 16 is a view illustrating a display device according to another embodiment of the disclosure.
- FIG. 17 is a view illustrating a relation between a wavelength and a reflectance/absorption rate of the display device of FIG. 16 exemplified as an organic light emitting diode (OLED).
- OLED organic light emitting diode
- FIG. 18 is a view illustrating a relation between a wavelength and a reflectance and comparing the display device (exemplified as an OLED display device having an anti-reflection layer) of FIG. 16 and a display device without an anti-reflection layer.
- FIG. 19 is a view illustrating a relation between a substrate reflectance and a fraction of power of the display device of FIG. 16 exemplified as an OLED display device.
- FIG. 20 is a view illustrating a relation between a wavelength and a reflectance/absorption rate of the display device of FIG. 16 exemplified as a quantum dot light emitting diode (QLED).
- QLED quantum dot light emitting diode
- FIG. 21 is a view illustrating a relation between a substrate reflectance and a fraction of power of the display device of FIG. 16 exemplified as an QLED display device.
- FIG. 22 is a view illustrating a display device according to another embodiment of the disclosure.
- FIG. 23 is a view illustrating a display device according to another embodiment of the disclosure.
- FIG. 1 is a view illustrating a display device according to an embodiment of the disclosure.
- a display device 100 includes a substrate 110 , a light absorption layer 120 , an optical matching layer 130 , a first transparent electrode 140 , a light emitting layer 150 , and a second transparent electrode 160 .
- the light absorption layer 120 is disposed on the substrate 110
- the optical matching layer 130 is disposed on the light absorption layer 120 .
- the first transparent electrode 140 is disposed on the optical matching layer 130
- the light emitting layer 150 is disposed on the first transparent electrode 140
- the second transparent electrode 160 is disposed on the light emitting layer 150 .
- the light absorption layer 120 is black resin, for example, for absorbing external ambient light.
- the light absorption layer 120 may include a multi-layer structure formed by alternately stacking different layers, such as a low reflectance multi-layer structure formed by alternately stacking a plurality of LiF layers and a plurality of Cr layers.
- the first transparent electrode 140 and the second transparent electrode 160 may be respectively an anode and a cathode that provide a current to the light emitting layer 150 , so that the light emitting layer 150 may emit light beams L 1 and L 2 .
- the light emitting layer 150 may be any organic light emitting layer suitable for an organic light emitting diode (OLED) display device, or an inorganic light emitting layer (or a quantum dot light emitting layer) suitable for a quantum dot light emitting diode (QLED) display device, for example.
- OLED organic light emitting diode
- QLED quantum dot light emitting diode
- the light matching layer 130 is disposed between the light absorption layer 120 and the first transparent electrode 140 .
- a portion of the light beam L 1 emitted downward may be reflected by the optical matching layer 130 to maintain a top output luminance without reflecting a significant amount of the ambient light.
- a refractive index of the light absorption layer 120 and a refractive index of the light matching layer 130 are set to satisfy the following condition: 0.008 ⁇ [(n1 ⁇ n2)/(n1+n2)] ⁇ 2 ⁇ 0.8, wherein n1 is the refractive index of the light absorption layer, and n2 is a refractive index of the optical matching layer.
- the refractive index of the light absorption layer 120 is smaller than the refractive index of the optical matching layer 130 .
- the top output luminance and a reflectance of the ambient light are controlled by adjusting the refractive indices of the optical matching layer 130 and the light absorption layer 120 , so as to increase an ambient contrast ratio of the display device 100 .
- the optical matching layer 130 may include a multi-layer structure formed by alternately stacking different films, such as a multi-layer structure formed by alternately stacking a plurality of SiO 2 and TiO 2 layers.
- the refractive index of the light absorption layer 120 and the refractive index of the light matching layer 130 satisfy the following condition: 0.008 ⁇ [(n1 ⁇ n2)/(n1+n2)] ⁇ 2 ⁇ 0.8.
- the refractive index of the light absorption layer 120 and the refractive index of the light matching layer 130 satisfy the following condition: 0.008 ⁇ [(n1 ⁇ n2)/(n1+n2)] ⁇ 2 ⁇ 0.3.
- the refractive index of the light absorption layer 120 and the refractive index of the light matching layer 130 satisfy the following condition: 0.008 ⁇ [(n1 ⁇ n2)/(n1+n2)] ⁇ 2 ⁇ 0.15.
- FIGS. 2A to 2C are views illustrating simulations on light emitting intensities of the display device 100 .
- FIG. 2A illustrates top and bottom light emitting intensities of red light with a wavelength of 650 nm
- FIG. 2B illustrates top and bottom light emitting intensities of green light with a wavelength of 550 nm
- FIG. 2C illustrates top and bottom light emitting intensities of blue light with a wavelength of 450 nm.
- the refractive index of the optical matching layer 130 when the refractive index of the optical matching layer 130 is higher, a light radiation rate of bottom emission is lower, and a higher light radiation rate of top emission indicates a higher top output luminance.
- the refractive index of the optical matching layer 130 may be set to be higher than or equal to 1.8.
- Table 1 shows a simulation of light emission of the display device where a thickness of the optical matching layer is set to be 70 nanometers, and the refractive index thereof is set to be 2.4. Assuming other conditions are equal, results of the simulation are provided in Table 1.
- a green light display device having the optical matching layer has a higher output luminance than that of a green light display device without the optical matching layer.
- FIG. 3 further illustrates a relation between the wavelengths and light emitting densities of the green light display devices. As shown in FIG. 3 , the display device having the optical matching layer has a significantly higher light emitting intensity within a specific wavelength range (e.g., 500 nm to 600 nm).
- the refractive index or thickness of the optical matching layer 130 of this embodiment may be adjusted according to the ambient light or a wavelength of light emitted by the light emitting layer 150 .
- the refractive index or thickness of the optical matching layer 130 may be adjusted to compensate and find a balance between colored light emitted by different color pixels and the ambient light.
- FIG. 4 is a view illustrating a display device according to another embodiment of the disclosure.
- a display device 400 of this embodiment is similar to the display device 100 of the previous embodiment, except for a main difference that a transflective layer 170 is disposed between the optical matching layer 130 and the first transparent electrode 140 in this embodiment.
- a material of the transflective layer 170 may be metal, such as Ag.
- a top output luminance of the display device 400 may be controlled by adjusting a thickness and a transmittance of the transflective layer 170 and the refractive index and the thickness of the optical matching layer 130 .
- the thickness of the transflective layer 170 of this embodiment may be in a range from 1 nm to 12 nm
- the transmittance of the transflective layer 170 may be in a range from 40% to 80%
- the refractive index thereof may be in a range from 0.1 to 0.4, for example.
- FIGS. 5 to 7 several embodiments ( FIGS. 5 to 7 ) of the display device are provided. It should be noted that in the embodiments of FIGS. 5 to 7 , like or similar elements are represented by like or similar symbols. Also, only the differences between the embodiments and the previous embodiments are described without repeating like or similar features and effects mentioned in the previous embodiments.
- FIG. 5 is a view illustrating a display device according to another embodiment of the disclosure.
- a display device 500 of this embodiment is similar to the display device 100 of the previous embodiment, except for a main difference that an anti-reflection layer 180 is additionally disposed on a second transparent electrode 160 in this embodiment.
- the anti-reflection layer 180 is a multi-layer structure, for example.
- two or more dielectric materials or metal materials having different refractive indices may be used.
- thicknesses of the respective layers may be adjusted based on needs, so as to cause destructive interference to the ambient light. Accordingly, the reflection of the ambient light may be reduced to increase the ambient contrast ratio.
- FIG. 6 is a view illustrating a display device according to another embodiment of the disclosure.
- a display device 600 of this embodiment is similar to the display device 400 of the previous embodiment, except for a main difference that an anti-reflection layer 180 is additionally disposed on a second transparent electrode 160 in this embodiment.
- the anti-reflection layer 180 is a multi-layer structure, for example.
- two or more dielectric materials or metal materials having different refractive indices may be used.
- thicknesses of the respective layers may be adjusted based on needs, so as to cause destructive interference to the ambient light. Accordingly, the reflection of the ambient light may be reduced to increase the ambient contrast ratio.
- FIG. 7 is a view illustrating a display device according to an embodiment of the disclosure.
- a display device 700 includes a substrate 110 , a light absorption layer 120 , a transflective electrode 270 , a light emitting layer 150 , and a second transparent electrode 160 .
- the light absorption layer 120 is disposed on the substrate 110 .
- the transflective electrode 270 is disposed on the light absorption layer 120
- the light emitting layer 150 is disposed on the transflective electrode 270
- the second transparent electrode 160 is disposed on the light emitting layer 150 .
- the light absorption layer 120 is black resin, for example, for absorbing external ambient light.
- the light absorption layer 120 may include a multi-layer structure formed by alternately stacking different layers, such as a low reflectance multi-layer structure formed by alternately stacking a plurality of LiF layers and a plurality of Cr layers.
- the transflective electrode 270 replaces the first transparent electrode 140 disposed at a lower position in the previous embodiment.
- the transflective electrode 270 and the second transparent electrode 160 respectively serve as an anode and a cathode, so as to provide a current to the light emitting layer 150 to emit a light beam.
- the light emitting layer 150 may be any organic light emitting layer suitable for an organic light emitting diode (OLED) display device, or an inorganic light emitting layer (or a quantum dot light emitting layer) suitable for a quantum dot light emitting diode (QLED) display device, for example.
- a material of the transflective electrode 270 may be metal, such as Ag.
- a top output luminance of the display device 700 may be controlled by adjusting a thickness and a transmittance of the transflective electrode 270 .
- FIGS. 8A and 8B are views illustrating results of optical simulations on the display device 700 .
- FIG. 8A is a view illustrating a relation between the thickness of the transflective electrode 270 and the reflectance of the ambient light
- FIG. 8B is a view illustrating a relation between the thickness of the transflective electrode 270 and a device luminance.
- a reflectance of the ambient light of the whole device may increase as the thickness of the transflective electrode 270 increases.
- the thickness is 12 nanometers
- the reflectance of the ambient light is 25%
- the value of 25% is approximately an upper limit acceptable in practice.
- the thickness of the transflective electrode 270 may be set in a range from 1 nanometer to 12 nanometers.
- the obtained output luminance is higher than an output luminance of 520 nits obtained when the conventional transparent electrode (e.g., indium tin oxide electrode) is used.
- the corresponding transmittance of the transflective electrode 270 may be in a range from 40% to 80%, and the refractive index of the transflective electrode 270 may be in a range from 0.1 to 1.4.
- FIG. 9 is a view illustrating a display device according to another embodiment of the disclosure.
- a display device 900 of this embodiment is similar to the display device 700 of the previous embodiment, except for a main difference that the optical matching layer 130 is disposed between the transflective electrode 270 and the light absorption layer 120 .
- the optical matching layer 130 is disposed between the transflective electrode 270 and the light absorption layer 120 .
- Like or similar features and effects mentioned in the previous embodiments are not repeated in this embodiment. In the following, only the difference between the embodiments is described.
- an output luminance of the display device 900 may be controlled by adjusting the thickness and the transmittance of the transflective electrode 270 and the refractive index and the thickness of the optical matching layer 130 .
- FIG. 10 is a view illustrating a display device according to another embodiment of the disclosure.
- a display device 1000 of this embodiment is similar to the display device 700 of the previous embodiment, except for a main difference that the anti-reflection layer 180 is disposed on the transparent electrode 160 in this embodiment.
- the anti-reflection layer 180 is a multi-layer structure, for example.
- two or more dielectric materials or metal materials having different refractive indices may be used.
- thicknesses of the respective layers may be adjusted based on needs, so as to cause destructive interference to the ambient light. Accordingly, the reflection of the ambient light may be reduced to increase the ambient contrast ratio.
- FIG. 11 is a view illustrating a display device according to another embodiment of the disclosure.
- a display device 1100 of this embodiment is similar to the display device 900 of the previous embodiment, except for a main difference that the anti-reflection layer 180 is disposed on the transparent electrode 160 in this embodiment.
- the anti-reflection layer 180 is a multi-layer structure, for example.
- two or more dielectric materials or metal materials having different refractive indices may be used.
- thicknesses of the respective layers may be adjusted based on needs, so as to cause destructive interference to the ambient light. Accordingly, the reflection of the ambient light may be reduced to increase the ambient contrast ratio.
- FIG. 12 is a view illustrating a display device according to another embodiment of the disclosure.
- a display device 1200 of this embodiment is similar to the display device 700 of the previous embodiment, except for a main difference that, in addition to a transflective metal layer 372 , a transflective electrode 370 of this embodiment further includes a transparent conductive layer 374 disposed on the transflective metal layer 372 .
- a top output luminance of the display device 1200 may be controlled by adjusting a thickness and a transmittance of the transflective metal layer 372 in this embodiment.
- the disclosure further provides an optical film capable of increasing the output luminance and the ambient contrast ratio under a circumstance that the ambient light reflection is controlled, and the optical film may be combined with a display device.
- the optical film is suitable for a self-illuminating display device such as an OLED device or a QLED device, so as to control a light beam emitted by the display device and the ambient light.
- a design concept of the optical film of the disclosure is to separate parts in the previous embodiments other than the conventional light emitting display element as an optical film. Accordingly, when the optical film is independently manufactured, the optical film may be disposed on various display devices to accomplish technical effects described in the embodiments.
- FIG. 13 is a view illustrating an optical film according to an embodiment of the disclosure.
- an optical film 1300 includes a substrate 110 and an optical matching layer 130 .
- the light absorption layer 120 is disposed on the substrate 110 in this embodiment.
- the optical matching layer 130 is disposed on the light absorption layer 120 .
- the refractive index of the light absorption layer 120 and the refractive index of the optical matching layer 130 satisfy 0.008 ⁇ [(n1 ⁇ n2)/(n1+n2)] ⁇ 2 ⁇ 0.8, wherein n1 is the refractive index of the light absorption layer 120 , and n2 is the refractive index of the optical matching layer 130 .
- the refractive index of the light absorption layer 120 may be smaller than the refractive index of the optical matching layer 130 .
- the refractive index of the optical matching layer 130 may be in a range from 1.8 to 2.8.
- the light absorption layer 120 may include a multi-layer structure formed by alternately stacking different layers, such as a low reflectance multi-layer structure formed by alternately stacking a plurality of LiF layers and a plurality of Cr layers.
- the light absorption layer 120 is not limited thereto.
- the light absorption layer 120 is additionally manufactured on the substrate 110 , a single substrate having a light absorbing property may be directly used in other embodiments not shown herein to replace a dual-layer structure formed by the light absorption layer 120 and the substrate 110 of this embodiment.
- FIG. 14 is a schematic view illustrating applying the optical film of FIG. 13 in a display device.
- the optical matching layer 130 of an optical film 1300 faces a display device 1400 and is attached to a side of the display device 1400 .
- the display device 1400 for example, is a light emitting diode display device manufactured on a substrate 110 a and having a first transparent electrode 140 , a light emitting layer 150 , and a second transparent electrode 160 .
- the display device 1400 outputs a light beam toward the bottom of the drawing.
- the ambient light may be absorbed with the optical matching layer 130 being matched with the light absorption layer 120 in the optical film 1300 , so as to avoid reflection of a significant amount of the ambient light. Also, a portion of the light beam from the light emitting layer 150 is reflected by the optical matching layer 130 to maintain a bottom output luminance.
- FIG. 15 is a view illustrating an optical film according to another embodiment of the disclosure.
- an optical film 1500 of this embodiment is similar to the optical film 1300 of the previous embodiment, except for a main difference that the transflective layer 170 is disposed on a surface of the optical matching layer 130 in this embodiment.
- the transflective layer 170 is disposed on a surface of the optical matching layer 130 in this embodiment.
- Like or similar features and effects mentioned in the previous embodiments are not repeated in this embodiment. In the following, only the difference between the embodiments is described.
- a material of the transflective layer 170 may be metal, such as Ag. If the optical film 1500 is combined with the display device, a portion of the ambient light and the light beam emitted by the display device may pass through the transflective layer 170 , and another portion may be reflected when the ambient light and the light beam emitted by the display device reach the transflective layer 170 .
- an output luminance of the display device may be controlled by adjusting the thickness and the transmittance of the transflective layer 170 and the refractive index of the optical matching layer 130 .
- the thickness of the transflective layer 170 of this embodiment may be in a range from 1 nm to 12 nm, and the transmittance of the transflective layer 170 may be in a range from 40% to 80%, for example.
- FIG. 16 is a view illustrating a display device according to another embodiment of the disclosure.
- a display device 1600 includes a substrate 110 , a first transparent electrode 140 , a light emitting layer 150 , a second transparent electrode 160 , an anti-reflection layer 180 a , and a light absorption layer 120 .
- the first transparent electrode 140 is disposed on the substrate 110
- the light emitting layer 150 is disposed on the first transparent electrode 140
- the second transparent electrode 160 is disposed on the light emitting layer 150 .
- the anti-reflection layer 180 a is disposed on the second transparent electrode 160
- the light absorption layer 120 is disposed on the anti-reflection layer 180 a.
- the substrate 110 may be formed of glass or plastics, and may be flexible or rigid. Also, the reflectance of the substrate 110 is in a range from 1.4 to 2.2.
- the first transparent electrode 140 and the second transparent electrode 160 may be respectively an anode and a cathode that provide a current to the light emitting layer 150 , so that the light emitting layer 150 may emit a light beam.
- Materials of the first transparent electrode 140 and the second transparent electrode 160 may include a transparent conductive oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), or a semi-transparent metal thin film.
- the display device 1600 further includes a first organic layer 152 and a second organic layer 154 .
- the first organic layer 152 is disposed on the first transparent electrode 140
- the light emitting layer 150 is disposed on the first organic layer 152
- the second organic layer 154 is disposed on the light emitting layer 150
- the second transparent electrode 160 is disposed on the second organic layer 154 .
- the first organic layer 152 and the second organic layer 154 may respectively serve as a hole injection layer, a hole transport layer, a hole blocking layer, or an electron transport layer.
- the light emitting layer 150 may be any organic light emitting layer suitable for an organic light emitting diode (OLED) display device, or an inorganic light emitting layer (or a quantum dot light emitting layer) suitable for a quantum dot light emitting diode (QLED) display device, for example.
- OLED organic light emitting diode
- QLED quantum dot light emitting diode
- the anti-reflection layer 180 a is a multi-layer structure, for example.
- two or more dielectric materials or metal materials having different refractive indices may be used.
- thicknesses of the respective layers may be adjusted based on needs, so as to cause destructive interference to the ambient light. Accordingly, the reflection of the ambient light may be reduced to increase the ambient contrast ratio.
- the light absorption layer 120 is black resin, for example, for absorbing external ambient light.
- the light absorption layer 120 may include a multi-layer structure formed by alternately stacking different layers, such as a low reflectance multi-layer structure formed by alternately stacking a plurality of LiF layers and a plurality of Cr layers.
- the light beam L 1 emitted from the light emitting layer 150 is transmitted toward the bottom of the drawing.
- Ambient light L 3 passing the respective layers may be absorbed by the light absorption layer 120 with assistance of the anti-reflection layer 180 a .
- a reflection coefficient of the anti-reflection layer 180 a is sufficiently low to substitute for the anti-reflection effect of a circular polarizer.
- the anti-reflection layer 180 a may help reduce an effective refractive index. With the assistance of a substrate with a high refractive index, the efficiencies of direct emission and substrate mode are improved.
- FIG. 17 is a view illustrating a relation between a wavelength and a reflectance/absorption rate of the display device of FIG. 16 exemplified as an organic light emitting diode (OLED).
- OLED organic light emitting diode
- R L ⁇ ⁇ ⁇ ⁇ 1 ⁇ ⁇ ⁇ 2 ⁇ V ⁇ ( ⁇ ) ⁇ R ⁇ ( ⁇ ) ⁇ S ⁇ ( ⁇ ) ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 1 ⁇ ⁇ ⁇ 2 ⁇ V ⁇ ( ⁇ ) ⁇ S ⁇ ( ⁇ ) ⁇ ⁇ ⁇ ⁇ ,
- V( ⁇ ) is a spectral eye sensitivity
- R( ⁇ ) is a reflectance of the display device
- S( ⁇ ) is a spectrum of the ambient light.
- the reflectance is 1.12%. The value is relatively low and allows the anti-reflection layer 180 a to substitute for the anti-reflection effect of a circular polarizer.
- FIG. 18 is a view illustrating a relation between a wavelength and a reflectance and comparing the display device (exemplified as an OLED display device having an anti-reflection layer) of FIG. 16 and a display device without an anti-reflection layer.
- Structures and thicknesses of the respective layers in the anti-reflection layer 180 a of the display device 1600 where an OLED is used as the light emitting layer 150 are provided in Table 2.
- the anti-reflection layer 180 a may result in further reducing the reflectance and increasing the efficiency.
- FIG. 19 is a view illustrating a relation between a substrate reflectance and a fraction of power of the display device of FIG. 16 exemplified as an OLED display device.
- FIG. 19 illustrates the efficiencies of direction emission and substrate mode of the display device shown in FIG. 16 .
- the efficiency of substrate mode significantly increases.
- the substrate refractive index exceeds 1.80, the efficiencies of direct emission and substrate mode may exceed 60%.
- FIG. 20 is a view illustrating a relation between a wavelength and a reflectance/absorption rate of the display device of FIG.
- QLED 16 exemplified as a quantum dot light emitting diode (QLED).
- QLED quantum dot light emitting diode
- FIG. 21 is a view illustrating a relation between a substrate reflectance and a fraction of power of the display device of FIG. 16 exemplified as a QLED display device having an inorganic light emitting layer (or a quantum dot light emitting layer).
- a QLED display device having an inorganic light emitting layer (or a quantum dot light emitting layer).
- the efficiency of substrate mode significantly increases.
- the substrate refractive index exceeds 1.90, the efficiencies of direct emission and substrate mode may exceed 80%.
- FIG. 22 is a view illustrating a display device according to another embodiment of the disclosure.
- a display device 2200 includes a substrate 110 , an anti-reflection layer 180 a , a first transparent electrode 140 , a first organic layer 152 , a light emitting layer 150 , a second organic layer 154 , a second transparent electrode 160 , a buffer layer 190 , and a light absorption layer 120 .
- the anti-reflection layer 180 a is disposed on the substrate 110 , the first transparent electrode 140 is disposed on the anti-reflection layer 180 a , the first organic layer 152 is disposed on the first transparent electrode 140 , the light emitting layer 150 is disposed on the first organic layer 152 , the second organic layer 154 is disposed on the light emitting layer 150 , the second transparent electrode 160 is disposed on the second organic layer 154 , the buffer layer 190 is disposed on the second transparent electrode 160 , and the light absorption layer 120 is disposed on the buffer layer 190 .
- the substrate 110 may be formed of glass or plastics, and may be flexible or rigid. Also, the reflectance of the substrate 110 is in a range from 1.4 to 2.2.
- the first transparent electrode 140 and the second transparent electrode 160 may be respectively an anode and a cathode that provide a current to the light emitting layer 150 , so that the light emitting layer 150 may emit a light beam.
- the materials of the first transparent electrode 140 and the second transparent electrode 160 may include a transparent conductive oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), or a semi-transparent metal thin film.
- the first organic layer 152 and the second organic layer 154 may respectively serve as a hole injection layer, a hole transport layer, a hole blocking layer, or an electron transport layer.
- the light emitting layer 150 may be any organic light emitting layer suitable for an organic light emitting diode (OLED) display device, or an inorganic light emitting layer (or a quantum dot light emitting layer) suitable for a quantum dot light emitting diode (QLED) display device, for example.
- the anti-reflection layer 180 a is a multi-layer structure, for example.
- two or more dielectric materials or metal materials having different refractive indices may be used.
- thicknesses of the respective layers may be adjusted based on needs, so as to cause destructive interference to the ambient light. Accordingly, the reflection of the ambient light may be reduced to increase the ambient contrast ratio.
- the light absorption layer 120 is black resin, for example, for absorbing external ambient light.
- the light absorption layer 120 may include a multi-layer structure formed by alternately stacking different layers, such as a low reflectance multi-layer structure formed by alternately stacking a plurality of LiF layers and a plurality of Cr layers.
- the buffer layer 190 serves to planarize a surface of the second transparent electrode 160 and separate the second transparent electrode 160 from the light absorption layer 120 . In other embodiments, the buffer layer 190 may be omitted.
- the light beam L 1 emitted from the light emitting layer 150 is transmitted toward the bottom of the drawing.
- the ambient light L 3 passing the respective layers may be absorbed by the light absorption layer 120 with assistance of the anti-reflection layer 180 a .
- the reflection coefficient of the anti-reflection layer 180 a is sufficiently low to substitute for the anti-reflection effect of a circular polarizer.
- the anti-reflection layer 180 a and the buffer layer 190 may help reduce the effective refractive index. With the assistance of a substrate with a high refractive index, the efficiencies of direct emission and substrate mode are improved.
- FIG. 23 is a view illustrating a display device according to another embodiment of the disclosure.
- a display device 2300 includes a substrate 110 , a first anti-reflection layer 180 b , a first transparent electrode 140 , a first organic layer 152 , a light emitting layer 150 , a second organic layer 154 , a second transparent electrode 160 , a second anti-reflection layer 180 c , and a light absorption layer 120 .
- the first anti-reflection layer 180 b is disposed on the substrate 110 .
- the first transparent electrode 140 is disposed on the first anti-reflection layer 180 b
- the first organic layer 152 is disposed on the first transparent electrode 140
- the light emitting layer 150 is disposed on the first organic layer 152
- the second organic layer 154 is disposed on the light emitting layer 150
- the second transparent electrode 160 is disposed on the second organic layer 154
- the second anti-reflection layer 180 c is disposed on the second transparent electrode 160
- the light absorption layer 120 is disposed on the second anti-reflection layer 180 c.
- the substrate 110 may be formed of glass or plastics, and may be flexible or rigid. Also, the reflectance of the substrate 110 is in a range from 1.4 to 2.2.
- the first transparent electrode 140 and the second transparent electrode 160 may be respectively an anode and a cathode that provide a current to the light emitting layer 150 , so that the light emitting layer 150 may emit a light beam.
- the materials of the first transparent electrode 140 and the second transparent electrode 160 may include a transparent conductive oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), or a semi-transparent metal thin film.
- the first organic layer 152 and the second organic layer 154 may respectively serve as a hole injection layer, a hole transport layer, a hole blocking layer, or an electron transport layer.
- the light emitting layer 150 may be any organic light emitting layer suitable for an organic light emitting diode (OLED) display device, or an inorganic light emitting layer (or a quantum dot light emitting layer) suitable for a quantum dot light emitting diode (QLED) display device, for example.
- the first anti-reflection layer 180 b and the second anti-reflection layer 180 c are respectively multi-layer structures, for example.
- two or more dielectric materials or metal materials having different refractive indices may be used.
- thicknesses of the respective layers may be adjusted based on needs, so as to cause destructive interference to the ambient light. Accordingly, the reflection of the ambient light may be reduced to increase the ambient contrast ratio.
- the first anti-reflection layer 180 a and the second anti-reflection layer 180 c may be formed by alternatively stacking two dielectric materials or metal materials having different refractive indices.
- the numbers of layers of the first anti-reflection layer 180 b and the second anti-reflection layer 180 c are different.
- the first anti-reflection layer 180 b has six layers
- the second anti-reflection layer 180 c has five layers.
- the numbers of layers of the first anti-reflection layer 180 b and the second anti-reflection layer 180 c are not limited thereto. In other embodiments, the number of layers of the first anti-reflection layer 180 b and the number of layers of the second anti-reflection layer 180 c may be the same.
- the light absorption layer 120 is black resin, for example, for absorbing external ambient light.
- the light absorption layer 120 may include a multi-layer structure formed by alternately stacking different layers, such as a low reflectance multi-layer structure formed by alternately stacking a plurality of LiF layers and a plurality of Cr layers.
- the light beam L 1 emitted from the light emitting layer 150 is transmitted toward the bottom of the drawing.
- the ambient light L 3 passing the respective layers may be absorbed by the light absorption layer 120 with assistance of the first anti-reflection layer 180 b and the second anti-reflection layer 180 c .
- the reflection coefficient of the first anti-reflection layer 180 b and the second anti-reflection layer 180 c are sufficiently low to substitute for the anti-reflection effect of a circular polarizer.
- the first anti-reflection layer 180 b and the second anti-reflection layer 180 c may help reduce the effective refractive index. With the assistance of a substrate with a high refractive index, the efficiencies of direct emission and substrate mode are improved.
Abstract
Description
- The disclosure relates to a display device and an optical film, and particularly relates to a display device and an optical film having a high ambient contrast ratio.
- A light emitting diode display is a display element utilizing the self-luminescent characteristics of light emitting materials to display. The luminescent structure of the light emitting diode display mainly includes a pair of electrodes and a light emitting layer. When a current flows through the light emitting layer via an anode and a cathode, electrons and holes are combined in the light emitting layer to generate excitons, so as to generate light beams of different colors based on material characteristics of the light emitting layer.
- For a display, the contrast ratio is one of the factors determining the display quality. However, stronger ambient light may result in a lower ambient contrast ratio, and the display quality of the display is thus affected. In the conventional light emitting diode display, a light absorption layer is provided to absorb the ambient light. However, with the light absorption layer provided, a portion of the light beams emitted by the light emitting layer may also be absorbed by the light absorption layer, thus making an output luminance inefficient.
- The disclosure provides a display device capable of providing a high output luminance and a high ambient contrast ratio under a circumstance that reflection of ambient light is controlled.
- An embodiment of the disclosure provides a display device including a substrate, a light absorption layer, an optical matching layer, a first transparent electrode, a light emitting layer, and a second transparent electrode. The light absorption layer is disposed on the substrate, and the optical matching layer is disposed on the light absorption layer. The first transparent electrode is disposed on the optical matching layer, the light emitting layer is disposed on the first transparent electrode, and the second transparent electrode is disposed on the light emitting layer.
- Another embodiment of the disclosure provides a display device including a substrate, a light absorption layer, a transflective electrode, a light emitting layer, and a transparent electrode. The light absorption layer is disposed on the substrate. The transflective electrode is disposed on the light absorption layer, the light emitting layer is disposed on the transflective electrode, and the transparent electrode is disposed on the light emitting layer. In addition, a transmittance of the transflective electrode is in a range from 40% to 80%.
- An embodiment of the disclosure provides a display device, including a substrate, a first transparent electrode, a light emitting layer, a second transparent electrode, an anti-reflection layer, and a light absorption layer. The first transparent electrode is disposed on the substrate. The light emitting layer is disposed on the first transparent electrode. The second transparent electrode is disposed on the light emitting layer. The anti-reflection layer is disposed on the second transparent electrode. The light absorption layer is disposed on the anti-reflection layer.
- An embodiment of the disclosure provides a display device including a substrate, a first anti-reflection layer, a first transparent electrode, a light emitting layer, a second transparent electrode, and a light absorption layer. The first anti-reflection layer is disposed on the substrate. The first transparent electrode is disposed on the first anti-reflection layer. The light emitting layer is disposed on the first transparent electrode. The second transparent electrode is disposed on the light emitting layer. The light absorption layer is disposed on the second transparent electrode.
- Several exemplary embodiments accompanied with figures are described in detail below to further describe the disclosure in details.
- The accompanying drawings are included to provide further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments and, together with the description, serve to explain the principles of the disclosure.
-
FIG. 1 is a view illustrating a display device according to an embodiment of the disclosure. -
FIGS. 2A to 2C are views illustrating simulations on light emitting intensities of the display device ofFIG. 1 . -
FIG. 3 is a view illustrating a relation between wavelengths and light emitting densities of display devices according to two embodiments of the disclosure. -
FIG. 4 is a view illustrating a display device according to another embodiment of the disclosure. -
FIG. 5 is a view illustrating a display device according to another embodiment of the disclosure. -
FIG. 6 is a view illustrating a display device according to another embodiment of the disclosure. -
FIG. 7 is a view illustrating a display device according to an embodiment of the disclosure. -
FIGS. 8A and 8B are views illustrating optical simulations on the display device ofFIG. 7 . -
FIG. 9 is a view illustrating a display device according to another embodiment of the disclosure. -
FIG. 10 is a view illustrating a display device according to another embodiment of the disclosure. -
FIG. 11 is a view illustrating a display device according to another embodiment of the disclosure. -
FIG. 12 is a view illustrating a display device according to another embodiment of the disclosure. -
FIG. 13 is a view illustrating an optical film according to an embodiment of the disclosure. -
FIG. 14 is a schematic view illustrating applying the optical film ofFIG. 13 in a display device. -
FIG. 15 is a view illustrating an optical film according to another embodiment of the disclosure. -
FIG. 16 is a view illustrating a display device according to another embodiment of the disclosure. -
FIG. 17 is a view illustrating a relation between a wavelength and a reflectance/absorption rate of the display device ofFIG. 16 exemplified as an organic light emitting diode (OLED). -
FIG. 18 is a view illustrating a relation between a wavelength and a reflectance and comparing the display device (exemplified as an OLED display device having an anti-reflection layer) ofFIG. 16 and a display device without an anti-reflection layer. -
FIG. 19 is a view illustrating a relation between a substrate reflectance and a fraction of power of the display device ofFIG. 16 exemplified as an OLED display device. -
FIG. 20 is a view illustrating a relation between a wavelength and a reflectance/absorption rate of the display device ofFIG. 16 exemplified as a quantum dot light emitting diode (QLED). -
FIG. 21 is a view illustrating a relation between a substrate reflectance and a fraction of power of the display device ofFIG. 16 exemplified as an QLED display device. -
FIG. 22 is a view illustrating a display device according to another embodiment of the disclosure. -
FIG. 23 is a view illustrating a display device according to another embodiment of the disclosure. -
FIG. 1 is a view illustrating a display device according to an embodiment of the disclosure. As shown inFIG. 1 , adisplay device 100 includes asubstrate 110, alight absorption layer 120, anoptical matching layer 130, a firsttransparent electrode 140, alight emitting layer 150, and a secondtransparent electrode 160. Thelight absorption layer 120 is disposed on thesubstrate 110, and theoptical matching layer 130 is disposed on thelight absorption layer 120. In addition, the firsttransparent electrode 140 is disposed on theoptical matching layer 130, thelight emitting layer 150 is disposed on the firsttransparent electrode 140, and the secondtransparent electrode 160 is disposed on thelight emitting layer 150. Thelight absorption layer 120 is black resin, for example, for absorbing external ambient light. Alternatively, thelight absorption layer 120 may include a multi-layer structure formed by alternately stacking different layers, such as a low reflectance multi-layer structure formed by alternately stacking a plurality of LiF layers and a plurality of Cr layers. The firsttransparent electrode 140 and the secondtransparent electrode 160 may be respectively an anode and a cathode that provide a current to thelight emitting layer 150, so that thelight emitting layer 150 may emit light beams L1 and L2. Here, thelight emitting layer 150 may be any organic light emitting layer suitable for an organic light emitting diode (OLED) display device, or an inorganic light emitting layer (or a quantum dot light emitting layer) suitable for a quantum dot light emitting diode (QLED) display device, for example. - In this embodiment, to prevent the light beam L1 emitted downward from being absorbed by the
light absorption layer 120, thelight matching layer 130 is disposed between thelight absorption layer 120 and the firsttransparent electrode 140. In addition, with theoptical matching layer 130 being matched with thelight absorption layer 120, a portion of the light beam L1 emitted downward may be reflected by theoptical matching layer 130 to maintain a top output luminance without reflecting a significant amount of the ambient light. Here, a refractive index of thelight absorption layer 120 and a refractive index of thelight matching layer 130 are set to satisfy the following condition: 0.008<[(n1−n2)/(n1+n2)]̂2<0.8, wherein n1 is the refractive index of the light absorption layer, and n2 is a refractive index of the optical matching layer. In this embodiment, the refractive index of thelight absorption layer 120 is smaller than the refractive index of theoptical matching layer 130. Namely, in this embodiment, the top output luminance and a reflectance of the ambient light are controlled by adjusting the refractive indices of theoptical matching layer 130 and thelight absorption layer 120, so as to increase an ambient contrast ratio of thedisplay device 100. Theoptical matching layer 130 may include a multi-layer structure formed by alternately stacking different films, such as a multi-layer structure formed by alternately stacking a plurality of SiO2 and TiO2 layers. - More specifically, when the
optical matching layer 130 includes a metal material, such as Al, Ag, or AlNd, etc., the refractive index of thelight absorption layer 120 and the refractive index of thelight matching layer 130 satisfy the following condition: 0.008<[(n1−n2)/(n1+n2)]̂2<0.8. Also, when theoptical matching layer 130 includes a material such as Si, the refractive index of thelight absorption layer 120 and the refractive index of thelight matching layer 130 satisfy the following condition: 0.008<[(n1−n2)/(n1+n2)]̂2<0.3. Furthermore, when theoptical matching layer 130 includes an organic material or a metal oxide, such as SiOx or Nb2Ox, etc., the refractive index of thelight absorption layer 120 and the refractive index of thelight matching layer 130 satisfy the following condition: 0.008<[(n1−n2)/(n1+n2)]̂2<0.15. -
FIGS. 2A to 2C are views illustrating simulations on light emitting intensities of thedisplay device 100.FIG. 2A illustrates top and bottom light emitting intensities of red light with a wavelength of 650 nm,FIG. 2B illustrates top and bottom light emitting intensities of green light with a wavelength of 550 nm, andFIG. 2C illustrates top and bottom light emitting intensities of blue light with a wavelength of 450 nm. As shown inFIGS. 2A to 2C , when the refractive index of theoptical matching layer 130 is higher, a light radiation rate of bottom emission is lower, and a higher light radiation rate of top emission indicates a higher top output luminance. In particular, when the refractive index of theoptical matching layer 130 is higher than or equal to 1.8, the tendency becomes more obvious. Accordingly, the refractive index of theoptical matching layer 130 may be set to be higher than or equal to 1.8. - Besides, Table 1 shows a simulation of light emission of the display device where a thickness of the optical matching layer is set to be 70 nanometers, and the refractive index thereof is set to be 2.4. Assuming other conditions are equal, results of the simulation are provided in Table 1.
-
TABLE 1 Luminance Reflectance to light with (nits) a wavelength of 550 nm Display device having optical 902 7.9% matching layer and light absorption layer Display device having light 498 1.8% absorption layer - As shown in Table 1, a green light display device having the optical matching layer has a higher output luminance than that of a green light display device without the optical matching layer. Moreover,
FIG. 3 further illustrates a relation between the wavelengths and light emitting densities of the green light display devices. As shown inFIG. 3 , the display device having the optical matching layer has a significantly higher light emitting intensity within a specific wavelength range (e.g., 500 nm to 600 nm). - Certainly, in practices, the refractive index or thickness of the
optical matching layer 130 of this embodiment may be adjusted according to the ambient light or a wavelength of light emitted by thelight emitting layer 150. In other words, when displaying, the refractive index or thickness of theoptical matching layer 130 may be adjusted to compensate and find a balance between colored light emitted by different color pixels and the ambient light. -
FIG. 4 is a view illustrating a display device according to another embodiment of the disclosure. As shown inFIG. 4 , adisplay device 400 of this embodiment is similar to thedisplay device 100 of the previous embodiment, except for a main difference that atransflective layer 170 is disposed between theoptical matching layer 130 and the firsttransparent electrode 140 in this embodiment. - A material of the
transflective layer 170 may be metal, such as Ag. When the ambient light and the light emitted by thelight emitting layer 150 reach thetransflective layer 170, a portion of the light may pass through thetransflective layer 170, and another portion of the light may be reflected. Thus, in this embodiment, a top output luminance of thedisplay device 400 may be controlled by adjusting a thickness and a transmittance of thetransflective layer 170 and the refractive index and the thickness of theoptical matching layer 130. Specifically, the thickness of thetransflective layer 170 of this embodiment may be in a range from 1 nm to 12 nm, the transmittance of thetransflective layer 170 may be in a range from 40% to 80%, and the refractive index thereof may be in a range from 0.1 to 0.4, for example. - In the following, several embodiments (
FIGS. 5 to 7 ) of the display device are provided. It should be noted that in the embodiments ofFIGS. 5 to 7 , like or similar elements are represented by like or similar symbols. Also, only the differences between the embodiments and the previous embodiments are described without repeating like or similar features and effects mentioned in the previous embodiments. -
FIG. 5 is a view illustrating a display device according to another embodiment of the disclosure. As shown inFIG. 5 , adisplay device 500 of this embodiment is similar to thedisplay device 100 of the previous embodiment, except for a main difference that ananti-reflection layer 180 is additionally disposed on a secondtransparent electrode 160 in this embodiment. Like or similar features and effects mentioned in the previous embodiments are not repeated in this embodiment. Theanti-reflection layer 180 is a multi-layer structure, for example. In addition, two or more dielectric materials or metal materials having different refractive indices may be used. Also, thicknesses of the respective layers may be adjusted based on needs, so as to cause destructive interference to the ambient light. Accordingly, the reflection of the ambient light may be reduced to increase the ambient contrast ratio. -
FIG. 6 is a view illustrating a display device according to another embodiment of the disclosure. As shown inFIG. 6 , adisplay device 600 of this embodiment is similar to thedisplay device 400 of the previous embodiment, except for a main difference that ananti-reflection layer 180 is additionally disposed on a secondtransparent electrode 160 in this embodiment. Like or similar features and effects mentioned in the previous embodiments are not repeated in this embodiment. Theanti-reflection layer 180 is a multi-layer structure, for example. In addition, two or more dielectric materials or metal materials having different refractive indices may be used. Also, thicknesses of the respective layers may be adjusted based on needs, so as to cause destructive interference to the ambient light. Accordingly, the reflection of the ambient light may be reduced to increase the ambient contrast ratio. -
FIG. 7 is a view illustrating a display device according to an embodiment of the disclosure. As shown inFIG. 7 , adisplay device 700 includes asubstrate 110, alight absorption layer 120, atransflective electrode 270, alight emitting layer 150, and a secondtransparent electrode 160. Thelight absorption layer 120 is disposed on thesubstrate 110. Thetransflective electrode 270 is disposed on thelight absorption layer 120, thelight emitting layer 150 is disposed on thetransflective electrode 270, and the secondtransparent electrode 160 is disposed on thelight emitting layer 150. Thelight absorption layer 120 is black resin, for example, for absorbing external ambient light. Alternatively, thelight absorption layer 120 may include a multi-layer structure formed by alternately stacking different layers, such as a low reflectance multi-layer structure formed by alternately stacking a plurality of LiF layers and a plurality of Cr layers. - In this embodiment, the
transflective electrode 270 replaces the firsttransparent electrode 140 disposed at a lower position in the previous embodiment. Also, thetransflective electrode 270 and the secondtransparent electrode 160 respectively serve as an anode and a cathode, so as to provide a current to thelight emitting layer 150 to emit a light beam. Here, thelight emitting layer 150 may be any organic light emitting layer suitable for an organic light emitting diode (OLED) display device, or an inorganic light emitting layer (or a quantum dot light emitting layer) suitable for a quantum dot light emitting diode (QLED) display device, for example. - A material of the
transflective electrode 270 may be metal, such as Ag. When the ambient light and the light emitted by thelight emitting layer 150 reach thetransflective electrode 270, a portion of the light may pass through thetransflective electrode 270, and another portion of the light may be reflected. Thus, in this embodiment, a top output luminance of thedisplay device 700 may be controlled by adjusting a thickness and a transmittance of thetransflective electrode 270. -
FIGS. 8A and 8B are views illustrating results of optical simulations on thedisplay device 700. Specifically,FIG. 8A is a view illustrating a relation between the thickness of thetransflective electrode 270 and the reflectance of the ambient light, andFIG. 8B is a view illustrating a relation between the thickness of thetransflective electrode 270 and a device luminance. As shown inFIG. 8A , a reflectance of the ambient light of the whole device may increase as the thickness of thetransflective electrode 270 increases. When the thickness is 12 nanometers, the reflectance of the ambient light is 25%, and the value of 25% is approximately an upper limit acceptable in practice. Thus, in this embodiment, the thickness of thetransflective electrode 270 may be set in a range from 1 nanometer to 12 nanometers. In addition, by substituting the thickness of the transflective electrode 8B from 1 nm to 12 nm set inFIG. 8A intoFIG. 8B , the obtained output luminance is higher than an output luminance of 520 nits obtained when the conventional transparent electrode (e.g., indium tin oxide electrode) is used. With the thickness of thetransflective electrode 270 ranging from 1 nm to 12 nm, the corresponding transmittance of thetransflective electrode 270 may be in a range from 40% to 80%, and the refractive index of thetransflective electrode 270 may be in a range from 0.1 to 1.4. -
FIG. 9 is a view illustrating a display device according to another embodiment of the disclosure. As shown inFIG. 9 , adisplay device 900 of this embodiment is similar to thedisplay device 700 of the previous embodiment, except for a main difference that theoptical matching layer 130 is disposed between thetransflective electrode 270 and thelight absorption layer 120. Like or similar features and effects mentioned in the previous embodiments are not repeated in this embodiment. In the following, only the difference between the embodiments is described. - As set forth in the previous embodiment, with the
optical matching layer 130 being matched with thelight absorption layer 120, a portion of the light beam emitted downward may be reflected by theoptical matching layer 130 to maintain a top output luminance without reflecting a significant amount of the ambient light. Moreover, in this embodiment, an output luminance of thedisplay device 900 may be controlled by adjusting the thickness and the transmittance of thetransflective electrode 270 and the refractive index and the thickness of theoptical matching layer 130. -
FIG. 10 is a view illustrating a display device according to another embodiment of the disclosure. As shown inFIG. 10 , adisplay device 1000 of this embodiment is similar to thedisplay device 700 of the previous embodiment, except for a main difference that theanti-reflection layer 180 is disposed on thetransparent electrode 160 in this embodiment. Like or similar features and effects mentioned in the previous embodiments are not repeated in this embodiment. Theanti-reflection layer 180 is a multi-layer structure, for example. In addition, two or more dielectric materials or metal materials having different refractive indices may be used. Also, thicknesses of the respective layers may be adjusted based on needs, so as to cause destructive interference to the ambient light. Accordingly, the reflection of the ambient light may be reduced to increase the ambient contrast ratio. -
FIG. 11 is a view illustrating a display device according to another embodiment of the disclosure. As shown inFIG. 11 , adisplay device 1100 of this embodiment is similar to thedisplay device 900 of the previous embodiment, except for a main difference that theanti-reflection layer 180 is disposed on thetransparent electrode 160 in this embodiment. Like or similar features and effects mentioned in the previous embodiments are not repeated in this embodiment. Theanti-reflection layer 180 is a multi-layer structure, for example. In addition, two or more dielectric materials or metal materials having different refractive indices may be used. Also, thicknesses of the respective layers may be adjusted based on needs, so as to cause destructive interference to the ambient light. Accordingly, the reflection of the ambient light may be reduced to increase the ambient contrast ratio. -
FIG. 12 is a view illustrating a display device according to another embodiment of the disclosure. As shown inFIG. 12 , adisplay device 1200 of this embodiment is similar to thedisplay device 700 of the previous embodiment, except for a main difference that, in addition to atransflective metal layer 372, atransflective electrode 370 of this embodiment further includes a transparent conductive layer 374 disposed on thetransflective metal layer 372. As set forth in the previous embodiment, a top output luminance of thedisplay device 1200 may be controlled by adjusting a thickness and a transmittance of thetransflective metal layer 372 in this embodiment. - Based on the embodiments, the disclosure further provides an optical film capable of increasing the output luminance and the ambient contrast ratio under a circumstance that the ambient light reflection is controlled, and the optical film may be combined with a display device. The optical film is suitable for a self-illuminating display device such as an OLED device or a QLED device, so as to control a light beam emitted by the display device and the ambient light. In other words, a design concept of the optical film of the disclosure is to separate parts in the previous embodiments other than the conventional light emitting display element as an optical film. Accordingly, when the optical film is independently manufactured, the optical film may be disposed on various display devices to accomplish technical effects described in the embodiments. Similarly, like or similar elements of the previous embodiments are described with like or similar symbols, and details in these respects will not be repeated in the following.
FIG. 13 is a view illustrating an optical film according to an embodiment of the disclosure. As shown inFIG. 13 , anoptical film 1300 includes asubstrate 110 and anoptical matching layer 130. Thelight absorption layer 120 is disposed on thesubstrate 110 in this embodiment. In addition, theoptical matching layer 130 is disposed on thelight absorption layer 120. In addition, the refractive index of thelight absorption layer 120 and the refractive index of theoptical matching layer 130 satisfy 0.008<[(n1−n2)/(n1+n2)]̂2<0.8, wherein n1 is the refractive index of thelight absorption layer 120, and n2 is the refractive index of theoptical matching layer 130. The refractive index of thelight absorption layer 120 may be smaller than the refractive index of theoptical matching layer 130. Also, the refractive index of theoptical matching layer 130 may be in a range from 1.8 to 2.8. Thelight absorption layer 120 may include a multi-layer structure formed by alternately stacking different layers, such as a low reflectance multi-layer structure formed by alternately stacking a plurality of LiF layers and a plurality of Cr layers. However, thelight absorption layer 120 is not limited thereto. - Even though the
light absorption layer 120 is additionally manufactured on thesubstrate 110, a single substrate having a light absorbing property may be directly used in other embodiments not shown herein to replace a dual-layer structure formed by thelight absorption layer 120 and thesubstrate 110 of this embodiment. -
FIG. 14 is a schematic view illustrating applying the optical film ofFIG. 13 in a display device. As shown inFIG. 14 , theoptical matching layer 130 of anoptical film 1300 faces adisplay device 1400 and is attached to a side of thedisplay device 1400. Thedisplay device 1400, for example, is a light emitting diode display device manufactured on asubstrate 110 a and having a firsttransparent electrode 140, alight emitting layer 150, and a secondtransparent electrode 160. In addition, thedisplay device 1400 outputs a light beam toward the bottom of the drawing. - Since the
optical film 1300 is disposed on a back side with respect to a light emitting direction of thedisplay device 1400 of this embodiment, the ambient light may be absorbed with theoptical matching layer 130 being matched with thelight absorption layer 120 in theoptical film 1300, so as to avoid reflection of a significant amount of the ambient light. Also, a portion of the light beam from thelight emitting layer 150 is reflected by theoptical matching layer 130 to maintain a bottom output luminance. -
FIG. 15 is a view illustrating an optical film according to another embodiment of the disclosure. As shown inFIG. 15 , anoptical film 1500 of this embodiment is similar to theoptical film 1300 of the previous embodiment, except for a main difference that thetransflective layer 170 is disposed on a surface of theoptical matching layer 130 in this embodiment. Like or similar features and effects mentioned in the previous embodiments are not repeated in this embodiment. In the following, only the difference between the embodiments is described. - A material of the
transflective layer 170 may be metal, such as Ag. If theoptical film 1500 is combined with the display device, a portion of the ambient light and the light beam emitted by the display device may pass through thetransflective layer 170, and another portion may be reflected when the ambient light and the light beam emitted by the display device reach thetransflective layer 170. Thus, in this embodiment, an output luminance of the display device may be controlled by adjusting the thickness and the transmittance of thetransflective layer 170 and the refractive index of theoptical matching layer 130. Specifically, the thickness of thetransflective layer 170 of this embodiment may be in a range from 1 nm to 12 nm, and the transmittance of thetransflective layer 170 may be in a range from 40% to 80%, for example. -
FIG. 16 is a view illustrating a display device according to another embodiment of the disclosure. As shown inFIG. 16 , adisplay device 1600 includes asubstrate 110, a firsttransparent electrode 140, alight emitting layer 150, a secondtransparent electrode 160, ananti-reflection layer 180 a, and alight absorption layer 120. The firsttransparent electrode 140 is disposed on thesubstrate 110, thelight emitting layer 150 is disposed on the firsttransparent electrode 140, and the secondtransparent electrode 160 is disposed on thelight emitting layer 150. Moreover, theanti-reflection layer 180 a is disposed on the secondtransparent electrode 160, and thelight absorption layer 120 is disposed on theanti-reflection layer 180 a. - The
substrate 110 may be formed of glass or plastics, and may be flexible or rigid. Also, the reflectance of thesubstrate 110 is in a range from 1.4 to 2.2. The firsttransparent electrode 140 and the secondtransparent electrode 160 may be respectively an anode and a cathode that provide a current to thelight emitting layer 150, so that thelight emitting layer 150 may emit a light beam. Materials of the firsttransparent electrode 140 and the secondtransparent electrode 160 may include a transparent conductive oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), or a semi-transparent metal thin film. - In this embodiment, a structure formed by several different material layers is provided between the first
transparent electrode 140 and the secondtransparent electrode 160. More specifically, thedisplay device 1600 further includes a firstorganic layer 152 and a secondorganic layer 154. The firstorganic layer 152 is disposed on the firsttransparent electrode 140, thelight emitting layer 150 is disposed on the firstorganic layer 152, the secondorganic layer 154 is disposed on thelight emitting layer 150, and the secondtransparent electrode 160 is disposed on the secondorganic layer 154. The firstorganic layer 152 and the secondorganic layer 154 may respectively serve as a hole injection layer, a hole transport layer, a hole blocking layer, or an electron transport layer. Here, thelight emitting layer 150 may be any organic light emitting layer suitable for an organic light emitting diode (OLED) display device, or an inorganic light emitting layer (or a quantum dot light emitting layer) suitable for a quantum dot light emitting diode (QLED) display device, for example. - The
anti-reflection layer 180 a is a multi-layer structure, for example. In addition, two or more dielectric materials or metal materials having different refractive indices may be used. Also, thicknesses of the respective layers may be adjusted based on needs, so as to cause destructive interference to the ambient light. Accordingly, the reflection of the ambient light may be reduced to increase the ambient contrast ratio. Thelight absorption layer 120 is black resin, for example, for absorbing external ambient light. Alternatively, thelight absorption layer 120 may include a multi-layer structure formed by alternately stacking different layers, such as a low reflectance multi-layer structure formed by alternately stacking a plurality of LiF layers and a plurality of Cr layers. - The light beam L1 emitted from the
light emitting layer 150 is transmitted toward the bottom of the drawing. Ambient light L3 passing the respective layers may be absorbed by thelight absorption layer 120 with assistance of theanti-reflection layer 180 a. When thicknesses of the layers of theanti-reflection layer 180 a are optimized, a reflection coefficient of theanti-reflection layer 180 a is sufficiently low to substitute for the anti-reflection effect of a circular polarizer. Theanti-reflection layer 180 a may help reduce an effective refractive index. With the assistance of a substrate with a high refractive index, the efficiencies of direct emission and substrate mode are improved. -
FIG. 17 is a view illustrating a relation between a wavelength and a reflectance/absorption rate of the display device ofFIG. 16 exemplified as an organic light emitting diode (OLED). As shown in the results of Table 2 andFIG. 17 , the structure of this embodiment provides a relatively low reflectance. Here, a luminous reflectance is defined as -
- wherein V(λ) is a spectral eye sensitivity, R(λ) is a reflectance of the display device, and S(λ) is a spectrum of the ambient light. The reflectance is 1.12%. The value is relatively low and allows the
anti-reflection layer 180 a to substitute for the anti-reflection effect of a circular polarizer. - Moreover,
FIG. 18 is a view illustrating a relation between a wavelength and a reflectance and comparing the display device (exemplified as an OLED display device having an anti-reflection layer) ofFIG. 16 and a display device without an anti-reflection layer. Structures and thicknesses of the respective layers in theanti-reflection layer 180 a of thedisplay device 1600 where an OLED is used as thelight emitting layer 150 are provided in Table 2. As shown inFIG. 18 and Table 2, theanti-reflection layer 180 a may result in further reducing the reflectance and increasing the efficiency. -
TABLE 2 Display device without Display device of FIG. 16 anti-reflection layer Material Thickness Material Thickness Structure SiO2 19 nm SiO2 — TiO2 31 nm TiO2 — SiO2 36 nm SiO2 — TiO2 18 nm TiO2 — SiO2 208 nm SiO2 — TiO2 17 nm TiO2 — Efficiency Direct Emission 9.9% Direct Emission 10.2% Substrate mode 49.1% Substrate mode 40.0% Luminous 1.12% 5.50% reflectance - Moreover,
FIG. 19 is a view illustrating a relation between a substrate reflectance and a fraction of power of the display device ofFIG. 16 exemplified as an OLED display device.FIG. 19 illustrates the efficiencies of direction emission and substrate mode of the display device shown inFIG. 16 . As shown inFIG. 19 , when the refractive index of the substrate increases, the efficiency of substrate mode significantly increases. When the substrate refractive index exceeds 1.80, the efficiencies of direct emission and substrate mode may exceed 60%. - If an inorganic light emitting layer (or a quantum dot light emitting layer) suitable for a quantum dot light emitting diode display device (QLED) is used as the
light emitting layer 150 of the display device shown inFIG. 16 , for example, structures and thicknesses of the respective layers in theanti-reflection layer 180 a of thedisplay device 1600 where an inorganic light emitting layer (or a quantum dot light emitting layer) suitable for a quantum dot light emitting diode display device (QLED) is used as thelight emitting layer 150 are provided in Table 3.FIG. 20 is a view illustrating a relation between a wavelength and a reflectance/absorption rate of the display device ofFIG. 16 exemplified as a quantum dot light emitting diode (QLED). As shown in Table 3 andFIG. 20 , in the whole visible spectrum, a light emitting reflectance of the display device is relatively low. The value of 0.78% is even lower than the value obtained when a circular polarizer is used. -
TABLE 3 Material Thickness Structure SiO2 34 nm TiO 2 10 nm SiO2 85 nm TiO 2 3 nm SiO2 245 nm TiO 2 20 nm Efficiency Direct Emission 8.5% Substrate mode 42.9% Luminous 0.78% reflectance -
FIG. 21 is a view illustrating a relation between a substrate reflectance and a fraction of power of the display device ofFIG. 16 exemplified as a QLED display device having an inorganic light emitting layer (or a quantum dot light emitting layer). As shown inFIG. 21 , when the refractive index of the substrate increases, the efficiency of substrate mode significantly increases. When the substrate refractive index exceeds 1.90, the efficiencies of direct emission and substrate mode may exceed 80%. -
FIG. 22 is a view illustrating a display device according to another embodiment of the disclosure. As shown inFIG. 22 , adisplay device 2200 includes asubstrate 110, ananti-reflection layer 180 a, a firsttransparent electrode 140, a firstorganic layer 152, alight emitting layer 150, a secondorganic layer 154, a secondtransparent electrode 160, abuffer layer 190, and alight absorption layer 120. Theanti-reflection layer 180 a is disposed on thesubstrate 110, the firsttransparent electrode 140 is disposed on theanti-reflection layer 180 a, the firstorganic layer 152 is disposed on the firsttransparent electrode 140, thelight emitting layer 150 is disposed on the firstorganic layer 152, the secondorganic layer 154 is disposed on thelight emitting layer 150, the secondtransparent electrode 160 is disposed on the secondorganic layer 154, thebuffer layer 190 is disposed on the secondtransparent electrode 160, and thelight absorption layer 120 is disposed on thebuffer layer 190. - The
substrate 110 may be formed of glass or plastics, and may be flexible or rigid. Also, the reflectance of thesubstrate 110 is in a range from 1.4 to 2.2. The firsttransparent electrode 140 and the secondtransparent electrode 160 may be respectively an anode and a cathode that provide a current to thelight emitting layer 150, so that thelight emitting layer 150 may emit a light beam. The materials of the firsttransparent electrode 140 and the secondtransparent electrode 160 may include a transparent conductive oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), or a semi-transparent metal thin film. - The first
organic layer 152 and the secondorganic layer 154 may respectively serve as a hole injection layer, a hole transport layer, a hole blocking layer, or an electron transport layer. Here, thelight emitting layer 150 may be any organic light emitting layer suitable for an organic light emitting diode (OLED) display device, or an inorganic light emitting layer (or a quantum dot light emitting layer) suitable for a quantum dot light emitting diode (QLED) display device, for example. - The
anti-reflection layer 180 a is a multi-layer structure, for example. In addition, two or more dielectric materials or metal materials having different refractive indices may be used. Also, thicknesses of the respective layers may be adjusted based on needs, so as to cause destructive interference to the ambient light. Accordingly, the reflection of the ambient light may be reduced to increase the ambient contrast ratio. Thelight absorption layer 120 is black resin, for example, for absorbing external ambient light. Alternatively, thelight absorption layer 120 may include a multi-layer structure formed by alternately stacking different layers, such as a low reflectance multi-layer structure formed by alternately stacking a plurality of LiF layers and a plurality of Cr layers. Thebuffer layer 190 serves to planarize a surface of the secondtransparent electrode 160 and separate the secondtransparent electrode 160 from thelight absorption layer 120. In other embodiments, thebuffer layer 190 may be omitted. - The light beam L1 emitted from the
light emitting layer 150 is transmitted toward the bottom of the drawing. The ambient light L3 passing the respective layers may be absorbed by thelight absorption layer 120 with assistance of theanti-reflection layer 180 a. When the thicknesses of the layers of theanti-reflection layer 180 a are optimized, the reflection coefficient of theanti-reflection layer 180 a is sufficiently low to substitute for the anti-reflection effect of a circular polarizer. Theanti-reflection layer 180 a and thebuffer layer 190 may help reduce the effective refractive index. With the assistance of a substrate with a high refractive index, the efficiencies of direct emission and substrate mode are improved. -
FIG. 23 is a view illustrating a display device according to another embodiment of the disclosure. As shown inFIG. 23 , adisplay device 2300 includes asubstrate 110, afirst anti-reflection layer 180 b, a firsttransparent electrode 140, a firstorganic layer 152, alight emitting layer 150, a secondorganic layer 154, a secondtransparent electrode 160, asecond anti-reflection layer 180 c, and alight absorption layer 120. Thefirst anti-reflection layer 180 b is disposed on thesubstrate 110. The firsttransparent electrode 140 is disposed on thefirst anti-reflection layer 180 b, the firstorganic layer 152 is disposed on the firsttransparent electrode 140, thelight emitting layer 150 is disposed on the firstorganic layer 152, the secondorganic layer 154 is disposed on thelight emitting layer 150, the secondtransparent electrode 160 is disposed on the secondorganic layer 154, thesecond anti-reflection layer 180 c is disposed on the secondtransparent electrode 160, and thelight absorption layer 120 is disposed on thesecond anti-reflection layer 180 c. - The
substrate 110 may be formed of glass or plastics, and may be flexible or rigid. Also, the reflectance of thesubstrate 110 is in a range from 1.4 to 2.2. The firsttransparent electrode 140 and the secondtransparent electrode 160 may be respectively an anode and a cathode that provide a current to thelight emitting layer 150, so that thelight emitting layer 150 may emit a light beam. The materials of the firsttransparent electrode 140 and the secondtransparent electrode 160 may include a transparent conductive oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), or a semi-transparent metal thin film. - The first
organic layer 152 and the secondorganic layer 154 may respectively serve as a hole injection layer, a hole transport layer, a hole blocking layer, or an electron transport layer. Here, thelight emitting layer 150 may be any organic light emitting layer suitable for an organic light emitting diode (OLED) display device, or an inorganic light emitting layer (or a quantum dot light emitting layer) suitable for a quantum dot light emitting diode (QLED) display device, for example. - The
first anti-reflection layer 180 b and thesecond anti-reflection layer 180 c are respectively multi-layer structures, for example. In addition, two or more dielectric materials or metal materials having different refractive indices may be used. Also, thicknesses of the respective layers may be adjusted based on needs, so as to cause destructive interference to the ambient light. Accordingly, the reflection of the ambient light may be reduced to increase the ambient contrast ratio. In this embodiment, thefirst anti-reflection layer 180 a and thesecond anti-reflection layer 180 c may be formed by alternatively stacking two dielectric materials or metal materials having different refractive indices. In addition, the numbers of layers of thefirst anti-reflection layer 180 b and thesecond anti-reflection layer 180 c are different. For example, thefirst anti-reflection layer 180 b has six layers, and thesecond anti-reflection layer 180 c has five layers. However, the numbers of layers of thefirst anti-reflection layer 180 b and thesecond anti-reflection layer 180 c are not limited thereto. In other embodiments, the number of layers of thefirst anti-reflection layer 180 b and the number of layers of thesecond anti-reflection layer 180 c may be the same. - The
light absorption layer 120 is black resin, for example, for absorbing external ambient light. Alternatively, thelight absorption layer 120 may include a multi-layer structure formed by alternately stacking different layers, such as a low reflectance multi-layer structure formed by alternately stacking a plurality of LiF layers and a plurality of Cr layers. - The light beam L1 emitted from the
light emitting layer 150 is transmitted toward the bottom of the drawing. The ambient light L3 passing the respective layers may be absorbed by thelight absorption layer 120 with assistance of thefirst anti-reflection layer 180 b and thesecond anti-reflection layer 180 c. When thicknesses of the layers of thefirst anti-reflection layer 180 b and thesecond anti-reflection layer 180 c are optimized, the reflection coefficient of thefirst anti-reflection layer 180 b and thesecond anti-reflection layer 180 c are sufficiently low to substitute for the anti-reflection effect of a circular polarizer. Thefirst anti-reflection layer 180 b and thesecond anti-reflection layer 180 c may help reduce the effective refractive index. With the assistance of a substrate with a high refractive index, the efficiencies of direct emission and substrate mode are improved. - It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.
Claims (35)
0.008<[(n1−n2)/(n1+n2)]̂2<0.8,
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN111435695A (en) * | 2019-01-11 | 2020-07-21 | 财团法人工业技术研究院 | Light emitting device and electrode thereof |
US11251409B2 (en) | 2017-06-28 | 2022-02-15 | Chengdu Boe Optoelectronics Technology Co., Ltd. | Display substrate and display device |
US20220089091A1 (en) * | 2020-09-18 | 2022-03-24 | Gentex Corporation | Concealment panel with asymmetric reflectance |
US20220140014A1 (en) * | 2020-11-05 | 2022-05-05 | Samsung Display Co., Ltd. | Display device and electronic apparatus |
US20220285655A1 (en) * | 2021-03-05 | 2022-09-08 | Samsung Display Co., Ltd. | Display apparatus |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102016101710A1 (en) * | 2016-02-01 | 2017-08-03 | Osram Oled Gmbh | OLED and method for producing an OLED |
WO2018165476A1 (en) | 2017-03-08 | 2018-09-13 | Sharp Gary D | Wide angle variable neutral density filter |
US11294113B2 (en) | 2017-07-17 | 2022-04-05 | Gary Sharp Innovations, Llc | Wide-angle compensation of uniaxial retarder stacks |
KR102430032B1 (en) * | 2017-08-16 | 2022-08-04 | 동우 화인켐 주식회사 | Transparent electrode laminate and method of fabricating the same |
US10593902B2 (en) * | 2017-09-29 | 2020-03-17 | University Of Central Florida Research Foundation, Inc. | Quantum dot light emitting devices (QLEDs) and method of manufacture |
US11269123B2 (en) | 2018-01-29 | 2022-03-08 | Gary Sharp Innovations, Llc | Hollow triple-pass optical elements |
US11249355B2 (en) | 2018-01-29 | 2022-02-15 | Gary Sharp Innovations, Llc | Color switch for reduced color cross-talk |
JP7284182B2 (en) | 2018-03-02 | 2023-05-30 | メタ プラットフォームズ テクノロジーズ, リミテッド ライアビリティ カンパニー | Retarder Stack Pairs for Conversion of Polarization Basis Vectors |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040206960A1 (en) * | 2003-03-28 | 2004-10-21 | Ryuji Nishikawa | Light emitting element and light emitting display |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5986401A (en) | 1997-03-20 | 1999-11-16 | The Trustee Of Princeton University | High contrast transparent organic light emitting device display |
US6515310B2 (en) | 2000-05-06 | 2003-02-04 | Semiconductor Energy Laboratory Co., Ltd. | Light-emitting device and electric apparatus |
US6750609B2 (en) | 2001-08-22 | 2004-06-15 | Xerox Corporation | OLEDs having light absorbing electrode |
US7259505B2 (en) | 2002-10-15 | 2007-08-21 | Eastman Kodak Company | OLED display with circular polarizer |
US6608333B1 (en) | 2002-12-19 | 2003-08-19 | Ritdisplay Corporation | Organic light emitting diode device |
TWI232066B (en) | 2002-12-25 | 2005-05-01 | Au Optronics Corp | Manufacturing method of organic light emitting diode for reducing reflection of external light |
US7365486B2 (en) | 2004-07-09 | 2008-04-29 | Au Optronics Corporation | High contrast organic light emitting device with electron transport layer including fullerenes |
EP1715375A1 (en) | 2005-04-22 | 2006-10-25 | Nemoptic | Bistable twisted nematic (BTN) liquid crystal display device |
US7973880B2 (en) * | 2005-09-02 | 2011-07-05 | Sharp Kabushiki Kaisha | Illumination device and liquid crystal display device |
WO2007069179A2 (en) | 2005-12-14 | 2007-06-21 | Koninklijke Philips Electronics N.V. | Reflective display having improved brightness and contrast |
TWI287142B (en) * | 2005-12-23 | 2007-09-21 | Ind Tech Res Inst | Reflective liquid crystal display integrating self-emission device and fabrication method thereof |
JP2010524172A (en) | 2007-04-04 | 2010-07-15 | エージェンシー・フォア・サイエンス・テクノロジー・アンド・リサーチ | LIGHT EMITTING ELEMENT STRUCTURE AND ITS MANUFACTURING METHOD |
US8076838B2 (en) | 2007-10-31 | 2011-12-13 | Seiko Epson Corporation | Light emitting device |
KR101076262B1 (en) | 2009-11-05 | 2011-10-27 | 한국과학기술원 | Anti-reflective organic light emitting diode device |
CN102034935B (en) | 2010-09-27 | 2012-07-04 | 南京邮电大学 | High-contrast top light-emitting type organic light-emitting diode |
CN103474450A (en) * | 2013-09-11 | 2013-12-25 | 京东方科技集团股份有限公司 | Display panel and manufacturing method thereof and display device |
-
2015
- 2015-11-30 US US14/954,933 patent/US9680132B1/en active Active
-
2016
- 2016-10-03 TW TW105131876A patent/TWI617023B/en active
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040206960A1 (en) * | 2003-03-28 | 2004-10-21 | Ryuji Nishikawa | Light emitting element and light emitting display |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11251409B2 (en) | 2017-06-28 | 2022-02-15 | Chengdu Boe Optoelectronics Technology Co., Ltd. | Display substrate and display device |
CN111435695A (en) * | 2019-01-11 | 2020-07-21 | 财团法人工业技术研究院 | Light emitting device and electrode thereof |
US11133485B2 (en) | 2019-01-11 | 2021-09-28 | Industrial Technology Research Institute | Light-emitting device and electrode thereof |
US20220089091A1 (en) * | 2020-09-18 | 2022-03-24 | Gentex Corporation | Concealment panel with asymmetric reflectance |
US20220140014A1 (en) * | 2020-11-05 | 2022-05-05 | Samsung Display Co., Ltd. | Display device and electronic apparatus |
US20220285655A1 (en) * | 2021-03-05 | 2022-09-08 | Samsung Display Co., Ltd. | Display apparatus |
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