Display device

Abstract

A display device includes: a substrate; a light-emitting element arranged on the substrate; a planarization layer arranged on the light-emitting element; a first refractive index layer arranged on the planarization layer and including a total reflection inclined surface that causes total reflection of light emitted from the light-emitting element in a front direction and a refractive inclined surface that causes refracting of light emitted from the light-emitting element in the front direction; a second refractive index layer arranged on the planarization layer to contact the refractive inclined surface and having a refractive index smaller than that of the first refractive index layer; and a third refractive index layer arranged on the first refractive index layer and the second refractive index layer to contact the total reflection inclined surface and having a refractive index greater than that of the first refractive index layer.

Description

Technical Field

[0001] Embodiments of the present invention relate to a display device, and more particularly, to a display device whose pixels include a light-emitting element. Background Art

[0002] The light-emitting display device includes two electrodes and an emission layer therebetween, wherein electrons injected from one electrode and holes injected from the other electrode are combined in the emission layer to generate excitons. The generated excitons change from an excited state to a ground state, releasing energy to emit light.

[0003] The light emitting display device includes a plurality of pixels including light emitting diodes (LEDs) as self-luminous elements, and each pixel includes a plurality of transistors for driving the light emitting diodes (LEDs) and at least one capacitor. The plurality of transistors basically include switching transistors and driving transistors.

[0004] The problem is that a large amount of light generated by the light emitting diode (LED) is lost when passing through multiple layers, resulting in low luminous efficiency. In order to solve this problem, attempts such as forming a lens have been made. However, it is not easy to control the curvature of the lens, and the distance between the lens and the light emitting diode (LED) is long, so there is a limit to improving the luminous efficiency. Summary of the invention

[0005] Embodiments of the present invention provide a display device capable of improving the light emitting efficiency of light generated by a light emitting element.

[0006] A display device according to an embodiment of the present invention includes: a substrate; a light-emitting element arranged on the substrate; a planarization layer arranged on the light-emitting element; a first refractive index layer arranged on the planarization layer and including a total reflection inclined surface that causes total reflection of light emitted from the light-emitting element in a front direction and a refractive inclined surface that causes refracting of light emitted from the light-emitting element in the front direction; a second refractive index layer arranged on the planarization layer to contact the refractive inclined surface and having a refractive index smaller than that of the first refractive index layer; and a third refractive index layer arranged on the first refractive index layer and the second refractive index layer to contact the total reflection inclined surface and having a refractive index greater than that of the first refractive index layer.

[0007] A refractive index difference between the first refractive index layer and the second refractive index layer may be 0.05 or more.

[0008] A refractive index difference between the first refractive index layer and the third refractive index layer may be 0.05 or more.

[0009] The thickness of the second refractive index layer may be the thickness of the first refractive index layer or greater.

[0010] A refractive inclination angle formed by the refractive inclination surface and the upper surface of the substrate may be less than 90 degrees and greater than or equal to 50 degrees.

[0011] The first refractive index layer may be provided in a ring form surrounding a light emitting region of the light emitting element on a plane.

[0012] The total reflection inclined surface may be an inner side surface of the first refractive index layer in a ring shape.

[0013] The refractive inclined surface may be an outer side surface of the first refractive index layer in a ring shape.

[0014] According to another embodiment of the present invention, a display device includes: a substrate; a light-emitting element arranged on the substrate; a planarization layer arranged on the light-emitting element; a first refractive index layer arranged on the planarization layer and including a refractive inclined surface that refracts light emitted from the light-emitting element in a front direction; a second refractive index layer arranged on the first refractive index layer to contact the refractive inclined surface, and including a total reflection inclined surface that totally reflects light emitted from the light-emitting element in the front direction, and having a refractive index greater than that of the first refractive index layer; and a third refractive index layer arranged on the second refractive index layer to contact the total reflection inclined surface, and having a refractive index greater than that of the second refractive index layer.

[0015] A refractive index difference between the first refractive index layer and the second refractive index layer may be 0.05 or more.

[0016] A refractive index difference between the second refractive index layer and the third refractive index layer may be 0.05 or more.

[0017] A refractive inclination angle formed by the refractive inclination surface and the upper surface of the substrate may be smaller than a total reflection inclination angle formed by the total reflection inclination surface and the upper surface of the substrate.

[0018] The thickness of the second refractive index layer may be the thickness of the first refractive index layer or greater.

[0019] The display device may further include: a first touch electrode disposed between the planarization layer and the first refractive index layer; and a second touch electrode disposed between the first refractive index layer and the second refractive index layer.

[0020] The display device may further include: a touch insulation layer disposed between the planarization layer and the first refractive index layer; a first touch electrode disposed between the planarization layer and the touch insulation layer; and a second touch electrode disposed between the touch insulation layer and the first refractive index layer.

[0021] According to another embodiment of the present invention, a display device includes: a substrate; a light-emitting element arranged on the substrate; a total reflection inclined surface that causes light emitted from the light-emitting element to be totally reflected in a front direction; and a refractive inclined surface that causes light emitted from the light-emitting element to be refracted in the front direction, wherein an area that emits light in the front direction in a pixel includes a front light area corresponding to the light-emitting area of ​​the light-emitting element, a total reflection light area corresponding to the total reflection inclined surface, and a refracted light area corresponding to the refractive inclined surface.

[0022] The total reflection inclined surface may be an interface between a first refractive index layer having a first refractive index and a third refractive index layer having a third refractive index greater than the first refractive index, and the refractive inclined surface may be an interface between the first refractive index layer and a second refractive index layer having a second refractive index less than the first refractive index.

[0023] The first refractive index layer may have a ring shape surrounding the light emitting region of the light emitting element in a plane.

[0024] The refractive inclined surface may be an interface between a first refractive index layer having a first refractive index and a second refractive index layer having a second refractive index greater than the first refractive index, and the total reflection inclined surface may be an interface between the second refractive index layer and a third refractive index layer having a third refractive index greater than the second refractive index.

[0025] A refractive inclination angle formed by the refractive inclination surface and the upper surface of the substrate may be smaller than a total reflection inclination angle formed by the total reflection inclination surface and the upper surface of the substrate.

[0026] By allowing light generated from the light emitting element to be emitted to the front surface through total reflection and refraction of the refractive index layer, the light emitting efficiency of the display device can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a cross-sectional view showing a display device according to an embodiment of the present invention.

[0028] Figure 2 It is shown Figure 1 A cross-sectional view of some layers of a display device.

[0029] Figure 3is a graph showing the relationship between the light emission angle and the total reflection tilt angle for front light emission according to an embodiment of the present invention.

[0030] Figure 4 is a graph showing the relationship between the refractive index of a refractive index layer for front light emission and the total reflection tilt angle according to an embodiment of the present invention.

[0031] Figure 5 is a graph showing the relationship between the light emission angle and the refraction tilt angle for front light emission according to an embodiment of the present invention.

[0032] Figure 6 is a graph showing the relationship between the light emission angle and the refraction tilt angle for front light emission according to an embodiment of the present invention.

[0033] Figure 7 is a graph showing the relationship between the light emission angle and the refraction tilt angle for front light emission according to an embodiment of the present invention.

[0034] Figure 8 is a graph showing the relationship between the light emission angle and the refraction tilt angle for front light emission according to an embodiment of the present invention.

[0035] Fig. 9 is to make some configurations with Figure 1 A display device is a cross-sectional view of a different display device.

[0036] Fig.10 is to make some configurations with Figure 1 A display device is a cross-sectional view of a different display device.

[0037] Figures 11 to 13 1 is a plan view showing various arrangement shapes of a plurality of pixels included in a display device according to an embodiment of the present invention.

[0038] Fig.14 is a cross-sectional view of a display device according to another embodiment of the present invention.

[0039] Fig.15 It is shown Fig.14 A cross-sectional view of some layers of a display device.

[0040] Fig.16 is a graph showing the relationship between the light emission angle and the total reflection inclined surface for front light emission according to an embodiment of the present invention.

[0041] Fig.17 is a graph showing the relationship between the light emission angle and the refractive inclined surface for front light emission according to an embodiment of the present invention.

[0042] Fig.18 is to make some configurations with Fig.14 A display device is a cross-sectional view of a different display device.

[0043] Fig.19 is to make some configurations with Fig.14 A display device is a cross-sectional view of a different display device.

[0044] Figure 20 to Figure 22 1 is a plan view showing various arrangement shapes of a plurality of pixels included in a display device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] Embodiments of the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the present invention are shown. Those skilled in the art will appreciate that the described embodiments may be modified in various different ways without departing from the spirit or scope of the present invention.

[0046] Furthermore, in the embodiments, the same reference numerals denote the same elements represented in the first embodiment throughout the specification, and only elements other than the elements of the first embodiment will be described in the subsequent embodiments.

[0047] In order to clarify the present invention, parts irrelevant to the description will be omitted. Throughout the specification, the same reference numerals represent the same elements.

[0048] In addition, for better understanding and ease of description, the size and thickness of each element shown in the drawings are arbitrarily described, and the present invention is not limited to the described size and thickness. In the drawings, the thickness of layers, films, panels, regions, etc. are exaggerated for clarity. In the drawings, the thickness of some layers and regions are exaggerated for better understanding and ease of description.

[0049] It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or there can also be intervening elements. Conversely, when an element is referred to as being "directly on" another element, there are no intervening elements. In addition, in this specification, the term "on..." or "above..." refers to being located above or below an object part, and does not necessarily mean being located on the upper side of the object part based on the direction of gravity.

[0050] In addition, unless explicitly described to the contrary, the word “comprise” and variations such as “including” or “having” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0051] Furthermore, in this specification, the phrase “on a plane” means when an object portion is viewed from above, and the phrase “on a cross section” means when a cross section taken by vertically cutting the object portion is viewed from the side.

[0052] First, refer to Figure 1 A display device according to an embodiment of the present invention is described.

[0053] Figure 1 is a cross-sectional view of a display device according to an embodiment of the present invention.

[0054] Reference Figure 1 According to the embodiment, the display device includes a substrate 110, a light emitting element EL disposed on the substrate 110, a planarization layer 420 disposed on the light emitting element EL, and a first refractive index layer 510, a second refractive index layer 520 and a third refractive index layer 510530 disposed on the planarization layer 420.

[0055] The substrate 110 may be an insulating substrate made of glass, quartz, ceramic, or plastic. Alternatively, the substrate 110 may be a metal substrate made of stainless steel, etc. The substrate 110 may have flexibility, and thus, the display device may have flexibility.

[0056] The buffer layer 120 may be disposed on the substrate 110. The buffer layer 120 may be made of silicon nitride (SiN x ) or a single layer of silicon nitride (SiN x ) and silicon oxide (SiO x ) is formed by a multi-layer structure. The buffer layer 120 can simultaneously flatten the surface of the substrate 110 while preventing the penetration of unnecessary components such as impurities or moisture. According to an embodiment, the buffer layer 120 can be omitted. The buffer layer 120 can be formed to cover the entire upper surface of the substrate 110.

[0057] The semiconductor layer 135 is disposed on the buffer layer 120. The semiconductor layer 135 may include a semiconductor material such as amorphous silicon, polycrystalline silicon, or an oxide semiconductor. In addition, the semiconductor layer 135 includes a channel 131 not doped with impurities and contact doping regions 132 and 133, which are disposed on respective sides of the channel 131 not doped with impurities. The contact doping regions 132 and 133 are a source region 132 and a drain region 133. Here, the type of impurities may vary depending on the type of transistor.

[0058] The gate insulating layer 140 is disposed on the semiconductor layer 135. The gate insulating layer 140 may include an inorganic insulating material such as silicon nitride (SiN x ), silicon oxide (SiO x ) and silicon oxynitride (SiON).

[0059] The gate electrode 125 is disposed on the gate insulating layer 140. The gate electrode 125 may overlap at least a portion of the semiconductor layer 135, particularly, the channel 131. Overlapping means overlapping in a vertical direction in a cross section and being positioned at the same region in a plane.

[0060] The interlayer insulating layer 160 is disposed on the gate electrode 125 and the gate insulating layer 140. The interlayer insulating layer 160 may include an inorganic insulating material or an organic insulating material.

[0061] The gate insulating layer 140 and the interlayer insulating layer 160 may include contact holes 162 and 164 overlapping at least a portion of the semiconductor layer 135. The contact holes 162 and 164 may be disposed on the semiconductor layer 135 contacting the doped regions 132 and 133.

[0062] Source electrode 173 and drain electrode 175 are disposed on interlayer insulating layer 160 . Source electrode 173 may be connected to source region 132 of semiconductor layer 135 through contact hole 162 , and drain electrode 175 may be connected to drain region 133 of semiconductor layer 135 through contact hole 164 .

[0063] The semiconductor layer 135, the gate electrode 125, the source electrode 173, and the drain electrode 175 may form a single transistor. The configuration of the transistor is not limited to the above example and may be changed to a known configuration in various ways. The light-emitting display device may include a switching transistor and a driving transistor, and the above transistor may be a driving transistor.

[0064] The protective layer 180 is disposed on the transistor and the interlayer insulating layer 160. The protective layer 180 may function as a planarization and removal step to improve the light emitting efficiency of the light emitting element EL to be formed on the protective layer 180. In addition, the protective layer 180 may include a contact hole 182 overlapping a portion of the drain electrode 175.

[0065] The protective layer 180 may be made of acrylic resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene resin, polyphenylene sulfide resin, and benzocyclobutene (BCB).

[0066] The light emitting element EL is disposed on the protective layer 180. The light emitting element EL includes a first electrode 191, a second electrode 270 disposed on the first electrode 191, and an emission layer 370 disposed between the first electrode 191 and the second electrode 270.

[0067] The first electrode 191 is disposed on the protective layer 180. The first electrode 191 may include a material such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium oxide (In 2 O 3), or a reflective metal such as lithium (Li), calcium (Ca), aluminum (Al), silver (Ag), magnesium (Mg) or gold (Au), or includes lithium fluoride / calcium (LiF / Ca) or lithium fluoride / aluminum (LiF / Al). The first electrode 191 is electrically connected to the drain electrode 175 of the thin film transistor through a contact hole 182 formed in the protective layer 180, thereby becoming the anode of the light emitting element EL. The first electrode 191 may include a first transparent electrode and a second transparent electrode made of a transparent conductive material, and a semi-reflective and semi-transmissive layer disposed between the first transparent electrode and the second transparent electrode and used to form a microcavity together with the second electrode 270. That is, the first electrode 191 may be made of a plurality of layers including a layer made of a transparent conductive material and a layer made of a reflective metal.

[0068] The pixel defining layer 350 is disposed on the edge portions of the protective layer 180 and the first electrode 191. The pixel defining layer 350 may include a resin such as a polyacrylic acid-based (polyacrylic acid), a polyimide-based (polyimide), or a silica-based inorganic material.

[0069] The emission layer 370 is disposed on the first electrode 191. The emission layer 370 may include at least one of an organic light-emitting material and an inorganic light-emitting material. The emission layer 370 may include any one of a red emission layer that emits red light, a green emission layer that emits green light, and a blue emission layer that emits blue light. The red emission layer, the green emission layer, and the blue emission layer are each disposed at a different pixel, so that a color image can be realized by their combination. In addition, the emission layer 370 may include a white emission layer that emits white light, and a color image can be realized by forming one of a red color filter, a green color filter, and a blue color filter in each pixel.

[0070] The second electrode 270 is disposed on the emission layer 370 and the pixel defining layer 350. The second electrode 270 may be made of a material such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium oxide (In 2 O 3 ), or a reflective metal such as lithium (Li), calcium (Ca), aluminum (Al), silver (Ag), magnesium (Mg) or gold (Au), or is made of lithium fluoride / calcium (LiF / Ca) or lithium fluoride / aluminum (LiF / Al). The second electrode 270 becomes a cathode of the light emitting element EL.

[0071] A portion of the second electrode 270 overlapping the pixel defining layer 350 protrudes compared to other portions, and thus an upper surface of the second electrode 270 may not be flat.

[0072] The planarization layer 420 may be disposed on the second electrode 270 and the upper surface may be flat. The planarization layer 420 may be made of a transparent organic material. For example, the planarization layer 420 is an organic insulating material such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, a polyimide resin, an unsaturated polyester resin, a polyphenyl resin, a polyphenylene sulfide resin, or benzocyclobutene.

[0073] When a flexible display device is implemented by bending the substrate 110 , the planarization layer 420 may play a role in improving the safety of elements by absorbing impact transmitted to elements such as a transistor, the first electrode 191 , and the second electrode 270 .

[0074] A first buffer layer 410 for protecting the light emitting element EL may be further disposed between the second electrode 270 and the planarization layer 420. A second buffer layer 430 may be disposed on the planarization layer 420. The first buffer layer 410 and the second buffer layer 430 may be made of an inorganic insulating material and may have a single layer or a multilayer structure. For example, the first buffer layer 410 and the second buffer layer 430 may include a silicon oxide (SiO x ), Silicon Nitride (SiN x ) or an inorganic material of silicon oxynitride (SiON). According to an embodiment, at least one of the first buffer layer 410 and the second buffer layer 430 may be omitted. In the following description, the second buffer layer 430 is omitted.

[0075] The first refractive index layer 510 is disposed on the planarization layer 420. The first refractive index layer 510 may overlap with the pixel defining layer 350 and may not overlap with the light emitting region ER. The light emitting region ER is a region in which light is emitted from the light emitting element EL, and is a region in which the light emitting layer 370 contacts both the first electrode 191 and the second electrode 270. The first refractive index layer 510 may be arranged in a ring around the light emitting region ER on a plane. The first refractive index layer 510 may include an opening OP corresponding to the light emitting region ER. The size of the opening OP may be the same as the size of the light emitting region ER. Alternatively, according to an embodiment, the opening OP may be formed to be a predetermined size larger than the light emitting region ER. That is, the first refractive index layer 510 may be spaced apart from the light emitting region ER by a predetermined distance in the horizontal direction.

[0076] The first refractive index layer 510 may include a total reflection inclined surface 510T that totally reflects light emitted from the light emitting element EL in a front direction and a refractive inclined surface 510R that refracts light emitted from the light emitting element EL in a front direction. The front direction refers to a direction perpendicular to the upper surface of the substrate 110 and indicates the direction of the light emitted from the light emitting element EL. Figure 1The total reflection inclined surface 510T may be an inner side surface of the annular first refractive index layer 510 , and the refractive inclined surface 510R may be an outer side surface of the annular first refractive index layer 510 .

[0077] The total reflection inclined surface 510T is an inclined surface forming an opening OP, and may be inclined at a total reflection inclination angle θ relative to the upper surface of the substrate 110. That is, the lower surface of the first refractive index layer 510 in contact with the planarization layer 420 forms the opening OP, and the inner surface connecting the lower surface and the upper surface of the first refractive index layer 510 is inclined in a direction toward the outside (i.e., the annular outer side of the opening OP) at a slope of the total reflection inclination angle θ, thereby forming the total reflection inclined surface 510T.

[0078] The refractive inclined surface 510R may be inclined at a refractive inclined angle λ relative to the upper surface of the substrate 110. That is, the outer surface connecting the lower surface and the upper surface of the first refractive index layer 510 may be inclined at a slope of the refractive inclined angle λ in a direction toward the inside of the opening OP (ie, the inside of the ring).

[0079] The second refractive index layer 520 is disposed on the planarization layer 420. The second refractive index layer 520 overlaps the pixel defining layer 350 and contacts the refractive inclined surface 510R of the first refractive index layer 510. That is, the refractive inclined surface 510R may be an interface between the first refractive index layer 510 and the second refractive index layer 520. The thickness H2 of the second refractive index layer 520 may be the same as the thickness H1 of the first refractive index layer 510, and the side of the second refractive index layer 520 may contact the refractive inclined surface 510R of the first refractive index layer 510. The thickness H1 of the first refractive index layer 510 is the height from the lower surface to the upper surface of the first refractive index layer 510, and the thickness H2 of the second refractive index layer 520 is the height from the lower surface to the upper surface of the second refractive index layer 520. The thickness H1 of the first refractive index layer 510 may be about 1.5 μm to 3.0 μm. The thickness H2 of the second refractive index layer 520 may be about 1.5 μm to 3.0 μm. However, the thickness H1 of the first refractive index layer 510 and the thickness H2 of the second refractive index layer 520 may be different, which will be described later with reference to Fig. 9 and Fig.10 Give a description.

[0080] The third refractive index layer 530 is disposed on the first refractive index layer 510 and the second refractive index layer 520. The third refractive index layer 530 may be formed to cover the entire upper surface of the substrate 110, and may overlap with the light emitting element EL in the opening OP of the first refractive index layer 510. The third refractive index layer 530 is in contact with the total reflection inclined surface 510T of the first refractive index layer 510. That is, the total reflection inclined surface 510T may be an interface between the first refractive index layer 510 and the third refractive index layer 530.

[0081] The first refractive index layer 510, the second refractive index layer 520, and the third refractive index layer 530 may be made of a transparent organic material or a mixture of an inorganic material and an organic material. The first refractive index layer 510 may be formed to have a predetermined refractive index, and the second refractive index layer 520 may be formed to have a refractive index smaller than that of the first refractive index layer 510. In addition, the third refractive index layer 530 may be formed to have a refractive index greater than that of the first refractive index layer 510. That is, the refractive index of the first refractive index layer 510 may be greater than that of the second refractive index layer 520, and the refractive index of the third refractive index layer 530 may be greater than that of the first refractive index layer 510. The refractive index difference between the first refractive index layer 510 and the second refractive index layer 520 may be 0.05 or more. The refractive index difference between the first refractive index layer 510 and the third refractive index layer 530 may be 0.05 or more. The refractive index of each of the first refractive index layer 510, the second refractive index layer 520, and the third refractive index layer 530 may be determined in the range of about 1.2 to 1.9.

[0082] When light generated from the light emitting element EL is incident on the first refractive index layer 510 from the third refractive index layer 530, the light is totally reflected from the total reflection inclined surface 510T due to the refractive index difference between the first refractive index layer 510 and the third refractive index layer 530, so that it can proceed in the front direction. When light generated from the light emitting element EL enters the second refractive index layer 520 from the first refractive index layer 510, the light is refracted from the refractive inclined surface 510R by the refractive index difference between the first refractive index layer 510 and the second refractive index layer 520, so that it can proceed in the front direction.

[0083] The polarization layer 610 may be disposed on the third refractive index layer 530 , and the cover window 620 may be disposed on the polarization layer 610 .

[0084] Meanwhile, a plurality of touch electrodes 710 and 720 for sensing touch may be provided in an area overlapping with the pixel defining layer 350. The first touch electrode 710 may be provided between the planarization layer 420 and the second refractive index layer 520, and the second touch electrode 720 may be provided on the second refractive index layer 520. The first touch electrode 710 may include: a plurality of transmission electrodes for transmitting a touch signal for sensing touch; and a plurality of receiving electrodes for forming a capacitance with the transmission electrode. The second touch electrode 720 may be a bridge electrode that connects a plurality of transmission electrodes to each other or connects a plurality of receiving electrodes to each other through a contact hole formed in the second refractive index layer 520.

[0085] Next, refer to Figures 2 to 8 The total reflection inclination angle θ of the total reflection inclination surface 510T and the refraction inclination angle λ of the refraction inclination surface 510R are described in further detail.

[0086] Figure 2 yes Figure 1 A cross-sectional view of some layers of a display device. Figure 2 The light emitting element EL, the planarization layer 420, the first refractive index layer 510, the second refractive index layer 520, and the third refractive index layer 530 are shown, and the light routes are indicated by arrows. Figure 2 Omitted Figure 1 The second buffer layer 430 is shown in FIG.

[0087] Reference Figure 2 , the light generated from the light emitting element EL travels in the front direction, and can be emitted not only as the front light FB, but also obliquely relative to the front direction. The side light emitted at an angle of light emission α (here, 0 degrees <α <90 degrees) relative to the front direction is totally reflected by the total reflection inclined surface 510T, and can pass through in the front direction to be emitted as the total reflection light TRB. In addition, another part of the side light can be refracted from the refractive inclined surface 510R and advance in the front direction to be emitted as the refracted light RB. In this way, the area in which light is emitted in the front direction in one pixel may include areas of the front light FB, the total reflection light TRB, and the refracted light RB. On a plane, the area of ​​the front light FB may correspond to the light emitting area ER of the light emitting element EL, the area of ​​the total reflection light TRB may correspond to the total reflection inclined surface 510T, and the area of ​​the refracted light RB may correspond to the refractive inclined surface 510R. In this way, the area where light is emitted in the front direction by the first refractive index layer 510, the second refractive index layer 520 and the third refractive index layer 530 can be extended to the area including the total reflected light TRB and the refracted light RB, so that the light emitting efficiency in the front direction can be improved.

[0088] Next, refer to Figure 3 and Figure 4 The relationship between the refractive index of the first refractive index layer 510 and the third refractive index layer 530, the light emission angle α, and the total reflection tilt angle θ is described.

[0089] Figure 3 is a graph showing the relationship between the light emission angle and the total reflection tilt angle for front light emission according to an embodiment of the present invention.

[0090] Reference Figure 3 , when the refractive index n1 of the first refractive index layer 510 is 1.5, in which the refractive index n3 of the third refractive index layer 530 is 1.55, 1.6, 1.65, 1.7, 1.75 and 1.8, the graphs Ra1, Ra2, Ra3, Ra4, Ra5 and Ra6 of the relationship between the total reflection inclination angle θ and the light emission angle α are determined.

[0091] When the refractive index n1 of the first refractive index layer 510 is 1.5 and the refractive index n3 of the third refractive index layer 530 is 1.55, for light having a light emission angle α greater than 0 degrees and less than or equal to 24.7 degrees, the total reflection tilt angle θ can be determined within a range less than 90 degrees and greater than or equal to 75.5 degrees.

[0092] When the refractive index n1 of the first refractive index layer 510 is 1.5 and the refractive index n3 of the third refractive index layer 530 is 1.6, for light having a light emission angle α greater than 0 degrees and less than or equal to 34.85 degrees, the total reflection inclination angle θ can be determined within the range of less than 90 degrees and greater than or equal to 70.0 degrees.

[0093] When the refractive index n1 of the first refractive index layer 510 is 1.5 and the refractive index n3 of the third refractive index layer 530 is 1.65, for light having a light emission angle α greater than 0 degrees and less than or equal to 43.77 degrees, the total reflection tilt angle θ can be determined within the range of less than 90 degrees and greater than or equal to 65.5 degrees.

[0094] When the refractive index n1 of the first refractive index layer 510 is 1.5 and the refractive index n3 of the third refractive index layer 530 is 1.7, for light having a light emission angle α greater than 0 degrees and less than or equal to 51.53 degrees, the total reflection inclination angle θ can be determined within the range of less than 90 degrees and greater than or equal to 62.0 degrees.

[0095] When the refractive index n1 of the first refractive index layer 510 is 1.5 and the refractive index n3 of the third refractive index layer 530 is 1.75, for light having a light emission angle α greater than 0 degrees and less than or equal to 55.54 degrees, the total reflection inclination angle θ can be determined within the range of less than 90 degrees and greater than or equal to 61.0 degrees.

[0096] When the refractive index n1 of the first refractive index layer 510 is 1.5 and the refractive index n3 of the third refractive index layer 530 is 1.8, for light with an exit angle α greater than 0 degrees and less than or equal to 56 degrees, the total reflection inclination angle θ can be determined within the range of less than 90 degrees and greater than or equal to 62.0 degrees.

[0097] As shown in the experimental results, as the difference between the refractive index n1 of the first refractive index layer 510 and the refractive index n3 of the third refractive index layer 530 increases, light having a wider range of light emission angles α may be totally reflected in the front direction.

[0098] Figure 4 is a graph showing the relationship between the refractive index of a refractive index layer for front light emission and the total reflection tilt angle according to an embodiment of the present invention.

[0099] Reference Figure 4, when the refractive index n1 of the first refractive index layer 510 is 1.5, 1.55, 1.6, 1.65, 1.7 and 1.75, when it is determined that the refractive index n3 of the third refractive index layer 530 is 0.05 or more greater than the refractive index n1 of the first refractive index layer 510, a curve graph of the minimum value of the total reflection inclination angle θ in which light can be totally reflected is displayed.

[0100] When the difference between the refractive index n1 of the first refractive index layer 510 and the refractive index n3 of the third refractive index layer 530 is 0.05, the minimum value of the total reflection tilt angle θ capable of totally reflecting light is a value between about 75.5 degrees and 76.5 degrees.

[0101] When the difference between the refractive index n1 of the first refractive index layer 510 and the refractive index n3 of the third refractive index layer 530 is 0.10, the minimum value of the total reflection tilt angle θ capable of totally reflecting light is a value between about 70 degrees and 71 degrees.

[0102] When the difference between the refractive index n1 of the first refractive index layer 510 and the refractive index n3 of the third refractive index layer 530 is 0.15, the minimum value of the total reflection tilt angle θ capable of totally reflecting light is a value between about 65.5 degrees and 66.5 degrees.

[0103] When the difference between the refractive index n1 of the first refractive index layer 510 and the refractive index n3 of the third refractive index layer 530 is 0.2, the minimum value of the total reflection tilt angle θ capable of totally reflecting light is a value between about 62 degrees and 63 degrees.

[0104] When the difference between the refractive index n1 of the first refractive index layer 510 and the refractive index n3 of the third refractive index layer 530 is 0.25, the minimum value of the total reflection tilt angle θ capable of totally reflecting light is a value between about 59 degrees and 59.5 degrees.

[0105] When the difference between the refractive index n1 of the first refractive index layer 510 and the refractive index n3 of the third refractive index layer 530 is 0.25, the minimum value of the total reflection tilt angle θ capable of totally reflecting light is about 56.5 degrees.

[0106] As shown in the experimental results, the greater the difference between the refractive index n1 of the first refractive index layer 510 and the refractive index n3 of the third refractive index layer 530, the smaller the total reflection tilt angle θ. For example, the total reflection tilt angle θ can be determined within a range of less than 90 degrees and greater than or equal to 50 degrees.

[0107] Next, refer to Figures 5 to 8 The refractive index, the light emission angle α, and the refractive inclination angle λ of the first refractive index layer 510 and the second refractive index layer 520 are described.

[0108] Figure 5is a graph showing the relationship between the light emission angle and the refraction tilt angle of the front light emission according to an embodiment of the present invention.

[0109] Reference Figure 5 , when the refractive index n2 of the second refractive index layer 520 is 1.5, in the cases where the refractive index n1 of the first refractive index layer 510 is 1.55, 1.6, 1.65, 1.7 and 1.75, graphs Rb1, Rb2, Rb3, Rb4 and Rb5 reflecting the relationship between the refractive inclination angle λ and the light emission angle α are shown.

[0110] The refraction inclination angle λ of the refraction inclination surface 510R for refraction of incident light in the front direction may be determined according to Equation 1.

[0111] (Equation 1)

[0112]

[0113] Here, λ is a refractive inclination angle, α is a light emission angle, n1 is a refractive index of the first refractive index layer 510 , and n2 is a refractive index of the second refractive index layer 520 .

[0114] From Equation 1, when the refractive index n2 of the second refractive index layer 520 is 1.5 and the refractive index n1 of the first refractive index layer 510 is 1.55, a graph Rb1 of the refractive inclination angle λ with respect to the light emission angle α may be calculated.

[0115] Similarly, when the refractive index n2 of the second refractive index layer 520 is 1.5 and the refractive index n1 of the first refractive index layer 510 is 1.6, a graph Rb2 of the relationship between the refractive inclination angle λ and the light emission angle α can be calculated. When the refractive index n2 of the second refractive index layer 520 is 1.5 and the refractive index n1 of the first refractive index layer 510 is 1.65, a graph Rb3 of the relationship between the refractive inclination angle λ and the light emission angle α can be calculated. When the refractive index n2 of the second refractive index layer 520 is 1.5 and the refractive index n1 of the first refractive index layer 510 is 1.7, a graph Rb4 of the relationship between the refractive inclination angle λ and the light emission angle α can be calculated. When the refractive index n2 of the second refractive index layer 520 is 1.5 and the refractive index n1 of the first refractive index layer 510 is 1.75, a graph Rb5 of the relationship between the refractive inclination angle λ and the light emission angle α can be calculated.

[0116] Figure 6 is a graph showing the relationship between the light emission angle and the refraction tilt angle for front light emission according to an embodiment of the present invention.

[0117] Reference Figure 6, when the refractive index n2 of the second refractive index layer 520 is 1.6, and the refractive index n1 of the first refractive index layer 510 is 1.65, 1.7, and 1.75, graphs Rc1, Rc2, and Rc3 determined by the relationship between the refractive inclination angle λ and the light emission angle α are shown.

[0118] Likewise, the relationship graphs Rc1, Rc2 and Rc3 of the refraction tilt angle λ to the light emission angle α can be calculated by Equation 1.

[0119] Figure 7 is a graph showing the relationship between the light emission angle and the refraction tilt angle for front light emission according to an embodiment of the present invention.

[0120] Reference Figure 7 , when the refractive index n2 of the second refractive index layer 520 is 1.65, in the case where the refractive index n1 of the first refractive index layer 510 is 1.7 and 1.75, graphs Rd1 and Rd2 determined by the relationship between the refractive inclination angle λ and the light emission angle α are shown.

[0121] Likewise, the relationship graphs Rd1 and Rd2 of the refraction tilt angle λ versus the light emission angle α can be calculated by Equation 1.

[0122] Figure 8 is a graph showing the relationship between the light emission angle and the refraction tilt angle for front light emission according to an embodiment of the present invention.

[0123] Reference Figure 8 , when the refractive index n2 of the second refractive index layer 520 is 1.7 and the refractive index n1 of the first refractive index layer 510 is 1.75, a graph Re1 determined by the relationship between the refractive inclination angle λ and the light emission angle α is shown.

[0124] Likewise, the relationship curve Re1 of the refraction tilt angle λ to the light emission angle α can be calculated by Equation 1.

[0125] like Figures 5 to 8 As shown in the experimental results, the refractive tilt angle λ can be determined within the range greater than 0 degrees and less than 90 degrees. When the refractive index n1 of the first refractive index layer 510, the refractive index n2 of the second refractive index layer 520 and the thickness of the planarization layer 420 are actually considered, the refractive tilt angle λ can be determined within the range from about 50 degrees or more to less than 90 degrees.

[0126] In this case, the greater the difference between the refractive index n1 of the first refractive index layer 510 and the refractive index n2 of the second refractive index layer 520, the smaller the size of the refractive tilt angle λ. When the thickness of the first refractive index layer 510 is preset to a constant thickness, as the size of the refractive tilt angle λ becomes smaller, the area of ​​the refracted light RB increases, so the area in which light is emitted in the forward direction can be further expanded. That is, by considering the thickness of the first refractive index layer 510, the refractive index n1 of the first refractive index layer 510, and the refractive index n2 of the second refractive index layer 520, the size of the appropriate refractive tilt angle λ is determined according to Equation 1, and the area in which light is emitted in the front direction can be determined.

[0127] In the following, reference is made to Fig. 9 and Fig.10 Describes the Figure 1 The description focuses on the different configurations of the display device. Figure 1 The difference compared to.

[0128] Fig. 9 is to make some configurations with Figure 1 A display device is a cross-sectional view of a different display device.

[0129] Reference Fig. 9 , the thickness H2 of the second refractive index layer 520 may be greater than the thickness H1 of the first refractive index layer 510. The second refractive index layer 520 may cover the refractive inclined surface 510R of the first refractive index layer 510 and a portion of the upper surface of the first refractive index layer 510. The second refractive index layer 520 does not cover the total reflection inclined surface 510T of the first refractive index layer 510.

[0130] Apart from these differences, Figure 1 The features of the described embodiments can all be applied with reference to Fig. 9 The embodiment described here is omitted. Figure 1 A repeated description of the features of the embodiments described in .

[0131] Fig.10 is to make some configurations with Figure 1 A display device is a cross-sectional view of a different display device.

[0132] Reference Fig.10 , the thickness H2 of the second refractive index layer 520 may be less than the thickness H1 of the first refractive index layer 510. The second refractive index layer 520 may cover a portion of the refractive inclined surface 510R of the first refractive index layer 510. That is, the second refractive index layer 520 may be in contact with a portion of the refractive inclined surface 510R of the first refractive index layer 510. The remaining portion of the refractive inclined surface 510R that is not in contact with the second refractive index layer 520 is in contact with the third refractive index layer 530.

[0133] In the refractive inclined surface 510R in contact with the third refractive index layer 530, light is not refracted in the front direction, but light is refracted in the side direction to advance. In order to improve the light emitting efficiency in the front direction, as Figure 1 or Fig. 9 As shown in , it is more advantageous to make all the refractive inclined surfaces 510R contact the second refractive index layer 520. However, for purposes such as improving side visibility, as Fig.10 As shown in , a portion of the refractive inclined surface 510R may be in contact with the third refractive index layer 530 .

[0134] Apart from these differences, Figure 1 The features of the described embodiments can all be applied with reference to Fig.10 The embodiment described here is omitted. Figure 1 Repeated description of the features of the embodiments described in .

[0135] In the following, reference is made to Figures 11 to 13 A form in which a plurality of pixels included in a display device are arranged on a plane is described.

[0136] Figures 11 to 13 1 is a plan view showing various arrangement shapes of a plurality of pixels included in a display device according to an embodiment of the present invention.

[0137] Reference Fig.11 , a plurality of pixels may be arranged in a pentile shape. A plurality of pixels may include a red light emitting region ERr, a green light emitting region ERg, and a blue light emitting region ERb. Each of the light emitting regions ERr, Erg, and ERb may be made of a polygon such as an approximate quadrilateral and an octagon. The red light emitting region ERr and the green light emitting region ERg may be alternately arranged in a diagonal direction, and the blue light emitting region ERb and the green light emitting region ERg may be alternately arranged in a diagonal direction. The red light emitting region ERr, the green light emitting region ERg, and the blue light emitting region ERb correspond to different pixels, respectively, and a color image may be realized by their combination.

[0138] The first refractive index layer 510 may be formed in a ring shape surrounding each of the red light emitting region ERr, the green light emitting region ERg, and the blue light emitting region ERb. The first refractive index layer 510 may not overlap the red light emitting region ERr, the green light emitting region ERg, and the blue light emitting region ERb. The total reflection inclined surface 510T may be disposed inside the ring-shaped first refractive index layer 510, and the refractive inclined surface 510R may be disposed outside the ring-shaped first refractive index layer 510.

[0139] The second refractive index layer 520 is disposed around the red, green, and blue light emitting regions ERr, Erg, and ERb, and overlaps with the refractive inclined surface 510R but does not overlap with the total reflection inclined surface 510T.

[0140] The arrangement of the plurality of pixels is not limited thereto, and as Fig.12 and Fig.13 As shown in , a plurality of pixels may be arranged in a matrix form.

[0141] like Fig.12 As shown in , a plurality of pixels may be arranged in a matrix form, and the light emitting region ER of each of the plurality of pixels may be formed into a quadrilateral. Fig.13 As shown in , a plurality of pixels may be arranged in a matrix form, and a light emitting region ER of each of the plurality of pixels may have a circular shape.

[0142] The sizes of the light emitting regions ER of the plurality of pixels may be the same. However, the present invention is not limited thereto, and the sizes of the light emitting regions ER of the plurality of pixels may be different. For example, the sizes of the light emitting regions ER having the same color may be the same, and the sizes of the light emitting regions ER having different colors may be different.

[0143] The first refractive index layer 510 may be formed into a quadrilateral or circle having a ring shape surrounding the light emitting region ER, the total reflection inclined surface 510T may be disposed inside the first refractive index layer 510 in a ring shape, and the refractive inclined surface 510R may be disposed outside the ring-shaped first refractive index layer 510 .

[0144] The second refractive index layer 520 may be disposed around the light emitting region ER, and may overlap with the refractive inclined surface 510R without overlapping with the total reflection inclined surface 510T.

[0145] Next, refer to Fig.14 A display device according to another embodiment of the present invention is described. Figure 1 The differences are explained.

[0146] Fig.14 is a cross-sectional view of a display device according to another embodiment of the present invention.

[0147] Reference Fig.14 , the first refractive index layer 540 is disposed on the planarization layer 420 .

[0148] The first refractive index layer 540 may overlap the pixel defining layer 350 and may not overlap the light emitting region ER. The first refractive index layer 540 may include a refractive inclined surface 540R that refracts light emitted from the light emitting element EL in a front direction.

[0149] The second refractive index layer 550 is disposed on the first refractive index layer 540 .

[0150] The second refractive index layer 550 may overlap with the pixel defining layer 350 and may not overlap with the light emitting region ER. The second refractive index layer 550 may cover the entirety of the first refractive index layer 540. That is, the second refractive index layer 550 may cover the refractive inclined surface 540R and the upper surface of the first refractive index layer 540. The refractive inclined surface 540R contacts the second refractive index layer 550. The second refractive index layer 550 may include an opening OP corresponding to the light emitting region ER. The size of the opening OP may be the same as the size of the light emitting region ER. In addition, according to an embodiment, the opening OP may be formed to be larger than the light emitting region ER by a predetermined size. That is, the second refractive index layer 550 may be spaced apart from the light emitting region ER by a predetermined distance in the horizontal direction. The first refractive index layer 540 may include an opening OP that is the same as the second refractive index layer 550 or an opening that is larger in size than the opening OP of the second refractive index layer 550.

[0151] The second refractive index layer 550 may include a total reflection inclined surface 550T that totally reflects the light emitted from the light emitting element EL in the front direction. The total reflection inclined surface 550T, which is an inclined surface forming the opening OP, may be inclined at a total reflection inclined angle θ' relative to the upper surface of the substrate 110. That is, the lower surface of the second refractive index layer 550 forms the opening OP, and the side surface of the second refractive index layer 550 that connects the lower surface and the upper surface and forms the opening OP may be inclined at a slope of the total reflection inclined angle θ' in a direction toward the outside of the opening OP.

[0152] The refractive inclined surface 540R may be inclined at a refractive inclined angle λ' relative to the upper surface of the substrate 110. That is, the side surface connecting the lower surface and the upper surface of the first refractive index layer 540 may be inclined at a slope of the refractive inclined angle λ' in a direction toward the outside of the opening OP. The refractive inclined angle λ' may be smaller than the total reflection inclined angle θ'. Therefore, the distance from the edge of the light emitting region ER to the outermost portion of the refractive inclined surface 540R may be greater than the distance from the edge of the light emitting region ER to the outermost portion of the total reflection inclined surface 550T. A portion of the refractive inclined surface 540R may overlap with the total reflection inclined surface 550T.

[0153] The thickness H4 of the second refractive index layer 550 may be greater than the thickness H3 of the first refractive index layer 540. According to an embodiment, the thickness H4 of the second refractive index layer 550 may be the same as the thickness H3 of the first refractive index layer 540. That is, the thickness H4 of the second refractive index layer 550 may be the thickness H3 of the first refractive index layer 540 or greater. When the thickness H4 of the second refractive index layer 550 is the same as the thickness H3 of the first refractive index layer 540, the second refractive index layer 550 may cover the refractive inclined surface 540R of the first refractive index layer 540 and may not cover the upper surface of the first refractive index layer 540. The thickness of the first refractive index layer 540 may be about 1.5 μm to 3.0 μm. The thickness of the second refractive index layer 550 may be about 1.5 μm to 3.0 μm.

[0154] The third refractive index layer 560 is disposed on the second refractive index layer 550. The third refractive index layer 560 may be formed to cover the entire upper surface of the substrate 110, and may overlap the light emitting element EL at the opening OP of the second refractive index layer 550. The third refractive index layer 560 contacts the total reflection inclined surface 550T of the second refractive index layer 550.

[0155] The first refractive index layer 540 may be made of a transparent organic material or a transparent inorganic material, or a mixture of an organic material and an organic material. The second refractive index layer 550 and the third refractive index layer 560 may be made of a transparent organic material or a mixture of an inorganic material and an organic material. The first refractive index layer 540 may be formed to have a predetermined refractive index, and the second refractive index layer 550 may be formed to have a refractive index greater than that of the first refractive index layer 510. In addition, the third refractive index layer 560 may be formed to have a refractive index greater than that of the second refractive index layer 550. That is, the refractive index of the second refractive index layer 550 may be greater than that of the first refractive index layer 540, and the refractive index of the third refractive index layer 560 may be greater than that of the second refractive index layer 550. The refractive index difference between the first refractive index layer 540 and the second refractive index layer 550 may be 0.05 or more. The refractive index difference between the second refractive index layer 550 and the third refractive index layer 560 may be 0.05 or more.

[0156] When light generated from the light emitting element EL is incident from the third refractive index layer 560 to the second refractive index layer 550, the light may be totally reflected from the total reflection inclined surface 550T and pass through in the front direction due to the refractive index difference between the second refractive index layer 550 and the third refractive index layer 560. Also, when light generated from the light emitting element EL is incident from the first refractive index layer 540 to the second refractive index layer 550, the light may be refracted at the refractive inclined surface 540R and the light may advance in the front direction due to the refractive index difference between the first refractive index layer 540 and the second refractive index layer 550.

[0157] Apart from these differences, Figure 1 The features of the described embodiments can all be applied with reference to Fig.14 The embodiment described here is omitted. Figure 1 Repeated description of the features of the embodiments described in .

[0158] Next, refer to Figures 15 to 17 The total reflection tilt angle θ′ of the total reflection tilt surface 550T and the refraction tilt angle λ′ of the refraction tilt surface 540R are further described in detail.

[0159] Fig.15 It is shown Fig.14 A cross-sectional view of some layers of a display device. Fig.15 In FIG. 4 , the light emitting element EL, the planarization layer 420 , the first refractive index layer 540 , the second refractive index layer 550 , and the third refractive index layer 560 are shown, and the optical paths are shown by arrows. Fig.15 Omitted Fig.14 The second buffer layer 430 is shown in FIG.

[0160] Reference Fig.15 , the light generated from the light emitting element EL travels in the front direction and can be emitted not only as the front light FB, but also can be emitted obliquely relative to the front direction. The side light emitted obliquely at a light emission angle α (here, 0 degrees <α <90 degrees) relative to the front direction travels in the front direction by total reflection from the total reflection inclined surface 550T, and can be emitted as total reflection light TRB. In addition, another part of the side light can be refracted at the refractive inclined surface 540R and advance in the front direction to be emitted as refracted light RB. In this way, the area in which light is emitted in the front direction in one pixel becomes the area of ​​front light FB, total reflection light TRB and refracted light RB. That is, the area in which light is emitted in the front direction by the first refractive index layer 540, the second refractive index layer 550 and the third refractive index layer 560 can extend to the area including the total reflection light TRB and the refracted light RB, and therefore, the luminous efficiency in the front direction can be improved.

[0161] Next, refer to Fig.16 The relationship between the refractive index of the second refractive index layer 550 and the third refractive index layer 560, the light emission angle α, and the total reflection tilt angle θ′ is described.

[0162] Fig.16 is a graph showing the relationship between the light emission angle and the total reflection inclined surface for front light emission according to an embodiment of the present invention.

[0163] Reference Fig.16, when the refractive index n2 of the second refractive index layer 550 is 1.5 and the refractive index n3 of the third refractive index layer 560 is 1.65, the minimum total reflection tilt angle θmin may be about 65 degrees. In this case, the range of the light emission angle α that can be totally reflected at the total reflection tilt surface 550T may be greater than 0 degrees and less than or equal to 50 degrees.

[0164] When the refractive index n2 of the second refractive index layer 550 is 1.5 and the refractive index n3 of the third refractive index layer 560 is 1.8, the minimum total reflection tilt angle θmin may be 57 degrees. In this case, the range of the light emission angle α that can be totally reflected from the total reflection tilt surface 550T may be greater than 0 degrees and less than or equal to 65 degrees.

[0165] Table 1 shows the minimum total reflection tilt angle θmin according to the refractive index n3 of the third refractive index layer 560 when the refractive index n2 of the second refractive index layer 550 is 1.5.

[0166] (Table 1)

[0167] n3 1.65 1.7 1.75 1.8 θmin 65 62 59.5 57

[0168] Table 2 shows an example of the light emission angle α according to the refractive index n3 of the third refractive index layer 560 and the total reflection inclination angle θ′ when the refractive index n2 of the second refractive index layer 550 is 1.5.

[0169] (Table 2)

[0170]

[0171] As described above, the total reflection inclination angle θ′ may be determined to be within a range of less than 90 degrees and greater than or equal to 50 degrees.

[0172] Next, refer to Fig.17 The relationship between the refractive index of the first refractive index layer 540 and the second refractive index layer 550, the light emission angle α, and the refractive tilt angle λ′ is described.

[0173] Fig.17 is a graph showing the relationship between the light emission angle and the refractive inclined surface for front light emission according to an embodiment of the present invention.

[0174] Reference Fig.17 , when the refractive index n1 of the first refractive index layer 540 is 1.5, in the cases where the refractive index n2 of the second refractive index layer 550 is 1.65, 1.7, 1.75 and 1.8, graphs Rf1, Rf2, Rf3 and Rf4 determined by the relationship between the refractive inclination angle λ' and the light emission angle α are shown.

[0175] The refractive inclination angle λ′ at which the refractive inclination surface 540R refracts incident light in the front direction can be determined according to Equation 2.

[0176] (Equation 2)

[0177]

[0178] Here, λ′ is a refractive inclination angle, α is a light emission angle, n1 is a refractive index of the first refractive index layer 540 , and n2 is a refractive index of the second refractive index layer 550 .

[0179] From Equation 2, when the refractive index n1 of the first refractive index layer 540 is 1.5 and the refractive index n2 of the second refractive index layer 550 is 1.65, a graph Rf1 of the refractive inclination angle λ′ with respect to the light emission angle α may be calculated.

[0180] Likewise, when the refractive index n1 of the first refractive index layer 540 is 1.5 and the refractive index n2 of the second refractive index layer 550 is 1.7, a graph Rf2 of the relationship between the refractive tilt angle λ' and the light emission angle α can be calculated. When the refractive index n1 of the first refractive index layer 540 is 1.5 and the refractive index n2 of the second refractive index layer 550 is 1.75, a graph Rf3 of the relationship between the refractive tilt angle λ' and the light emission angle α can be calculated. When the refractive index n1 of the first refractive index layer 540 is 1.5 and the refractive index n2 of the second refractive index layer 550 is 1.8, a graph Rf4 of the relationship between the refractive tilt angle λ' and the light emission angle α can be calculated.

[0181] The refraction tilt angle λ′ may be determined to be in a range greater than 0 degrees and less than or equal to 10 degrees.

[0182] In the following, reference is made to Fig.18 and Fig.19 Describe Fig.14 The description is based on some different embodiments of the display device. Fig.14 Compared to the difference.

[0183] Fig.18 is to make some configurations with Fig.14 A display device is a cross-sectional view of a different display device.

[0184] Reference Fig.18, touch electrodes 710 and 720 for detecting touch may be provided in an area overlapping with the pixel defining layer 350. The first touch electrode 710 may be provided between the planarization layer 420 and the first refractive index layer 540, and the second touch electrode 720 may be provided between the first refractive index layer 540 and the second refractive index layer 550. The first touch electrode 710 may include a plurality of transmission electrodes for transmitting a touch signal for touch sensing; and a plurality of receiving electrodes for forming a capacitance with the transmission electrode. The second touch electrode 720 may be a bridge electrode that connects a plurality of transmission electrodes to each other or connects a plurality of receiving electrodes to each other through a contact hole formed in the first refractive index layer 540.

[0185] Apart from these differences, Fig.14 The features of the described embodiments can all be applied with reference to Fig.18 The embodiment described here is omitted. Fig.14 A repeated description of the features of the embodiments described in .

[0186] Fig.19 is to make some configurations with Fig.14 A display device is a cross-sectional view of a different display device.

[0187] Reference Fig.19 The touch insulation layer 440 may be disposed between the planarization layer 420 and the first refractive index layer 540. The touch insulation layer 440 may be disposed on the second buffer layer 430.

[0188] The touch electrodes 710 and 720 for detecting touch may be provided in an area overlapping with the pixel defining layer 350. The first touch electrode 710 may be provided between the planarization layer 420 and the touch insulating layer 440, and the second touch electrode 720 may be provided between the touch insulating layer 440 and the first refractive index layer 540. The second touch electrode 720 may include a plurality of transmission electrodes for transmitting touch signals for touch sensing; and a plurality of receiving electrodes for forming a capacitance with the transmission electrode. The first touch electrode 710 may be a bridge electrode that connects a plurality of transmission electrodes to each other or connects a plurality of receiving electrodes to each other through a contact hole formed in the touch insulating layer 440.

[0189] Apart from these differences, Fig.14 The features of the described embodiments can all be applied with reference to Fig.19 The embodiment described here is omitted. Fig.14 A repeated description of the features of the embodiments described in .

[0190] In the following, reference is made to Figure 20 to Figure 22 The present invention describes the form in which a plurality of pixels included in a display device are arranged on a plane. The description focuses on Figures 11 to 13 The difference compared to the embodiment.

[0191] Figure 20 to Figure 22 1 is a plan view showing various arrangement shapes of a plurality of pixels included in a display device according to an embodiment of the present invention.

[0192] like Fig. 20 As shown in, a plurality of pixels can be arranged in the form of a pentile. The first refractive index layer 540 and the second refractive index layer 550 are arranged around the red light emitting area ERr, the green light emitting area ERg, and the blue light emitting area ERb. The total reflection inclined surface 550T of the second refractive index layer 550 can form a ring around each of the red light emitting area ERr, the green light emitting area ERg, and the blue light emitting area ERb. The refractive inclined surface 540R of the first refractive index layer 540 can form a ring around each of the red light emitting area ERr, the green light emitting area ERg, and the blue light emitting area ERb. On a plane, the refractive inclined surface 540R can form a wider area from the light emitting areas ERr, Erg, and ERb than the total reflection inclined surface 550T.

[0193] like Fig.21 As shown in FIG. , a plurality of pixels are arranged in a matrix form and the light emitting region ER is formed into a quadrilateral, or as shown in FIG. Fig. 22 As shown, a plurality of pixels may be arranged in a matrix form and the light emitting region ER may be formed in a circular shape. Even in this case, the first refractive index layer 540 and the second refractive index layer 550 are disposed around the light emitting region ER, and the total reflection inclined surface 550T of the second refractive index layer 550 and the refractive inclined surface 540R of the first refractive index layer 540 may form a ring around the light emitting region ER. On a plane, the refractive inclined surface 540R may form a wider area from the light emitting regions ERr, Erg, and ERb than the total reflection inclined surface 550T.

[0194] The above-mentioned drawings and detailed description are examples for the present invention, and are provided to explain the present invention, and the scope of the present invention described in the claims is not limited thereto. Therefore, it will be appreciated by those skilled in the art that various modifications may be made and other equivalent embodiments may be obtained. Therefore, the actual scope of the present invention must be determined by the spirit of the appended scope of rights.

Claims

1. A display device, comprising: substrate; A light emitting element is disposed on the substrate; A planarization layer, disposed on the light emitting element; a first refractive index layer disposed on the planarization layer and including a total reflection inclined surface that causes total reflection of light emitted from the light emitting element in a front direction and a refraction inclined surface that causes refracting of light emitted from the light emitting element in the front direction; a second refractive index layer disposed on the planarization layer to contact the refractive inclined surface and having a refractive index smaller than that of the first refractive index layer; as well as a third refractive index layer disposed on the first refractive index layer and the second refractive index layer to be in contact with the total reflection inclined surface and having a refractive index greater than the refractive index of the first refractive index layer, The first refractive index layer and the second refractive index layer are outside the light emitting region of the light emitting element.

2. The display device according to claim 1, wherein A refractive index difference between the first refractive index layer and the second refractive index layer is 0.05 or more.

3. The display device according to claim 1, wherein A refractive index difference between the first refractive index layer and the third refractive index layer is 0.05 or more.

4. The display device according to claim 1, wherein The thickness of the second refractive index layer is the thickness of the first refractive index layer or more.

5. The display device according to claim 1, wherein A refractive inclination angle formed by the refractive inclination surface and the upper surface of the substrate is less than 90 degrees and greater than or equal to 50 degrees.

6. The display device according to claim 1, wherein The first refractive index layer is provided in a ring form surrounding the light emitting region of the light emitting element on a plane.

7. The display device according to claim 6, wherein The total reflection inclined surface is an inner side surface of the first refractive index layer in a ring shape.

8. The display device according to claim 6, wherein The refractive inclined surface is an outer side surface of the annular first refractive index layer.

9. A display device, comprising: substrate; A light emitting element is disposed on the substrate; A planarization layer, disposed on the light emitting element; a first refractive index layer disposed on the planarization layer and including a refractive inclined surface that refracts light emitted from the light emitting element in a front direction; a second refractive index layer provided on the first refractive index layer to contact the refractive inclined surface, including a total reflection inclined surface that causes total reflection of light emitted from the light emitting element in the front direction, and having a refractive index greater than that of the first refractive index layer; as well as a third refractive index layer disposed on the second refractive index layer to be in contact with the total reflection inclined surface and having a refractive index greater than the refractive index of the second refractive index layer, The first refractive index layer and the second refractive index layer are outside the light emitting region of the light emitting element.

10. The display device according to claim 9, wherein A refractive index difference between the first refractive index layer and the second refractive index layer is 0.05 or more.

11. The display device according to claim 9, wherein A refractive index difference between the second refractive index layer and the third refractive index layer is 0.05 or more.

12. The display device according to claim 9, wherein A refraction tilt angle formed by the refraction tilt surface and an upper surface of the substrate is smaller than a total reflection tilt angle formed by the total reflection tilt surface and the upper surface of the substrate.

13. The display device according to claim 9, wherein The thickness of the second refractive index layer is the thickness of the first refractive index layer or more.

14. The display device according to claim 9, further comprising: A first touch electrode is disposed between the planarization layer and the first refractive index layer; as well as The second touch electrode is arranged between the first refractive index layer and the second refractive index layer.

15. The display device according to claim 9, further comprising: A touch insulating layer, disposed between the planarization layer and the first refractive index layer; A first touch electrode is arranged between the planarization layer and the touch insulation layer; as well as The second touch electrode is arranged between the touch insulation layer and the first refractive index layer.

16. A display device, comprising: substrate; A light emitting element is disposed on the substrate; A total reflection inclined surface causes the light emitted from the light emitting element to be totally reflected in a front direction; as well as The refracting inclined surface refracts the light emitted from the light emitting element in the front direction, wherein the area emitting light in the front direction in one pixel includes a front light area corresponding to the light emitting area of ​​the light emitting element, a total reflection light area corresponding to the total reflection inclined surface, and a refracted light area corresponding to the refracted inclined surface, The total reflection inclined surface and the refractive inclined surface are outside the light emitting area of ​​the light emitting element.

17. The display device according to claim 16, wherein The total reflection inclined surface is an interface between a first refractive index layer having a first refractive index and a third refractive index layer having a third refractive index greater than the first refractive index, and The refractive inclined surface is an interface between the first refractive index layer and a second refractive index layer having a second refractive index smaller than the first refractive index.

18. The display device according to claim 17, wherein The first refractive index layer has a ring shape surrounding the light emitting region of the light emitting element in a plane.

19. The display device according to claim 16, wherein The refractive inclined surface is an interface between a first refractive index layer having a first refractive index and a second refractive index layer having a second refractive index greater than the first refractive index, and The total reflection inclined surface is an interface between the second refractive index layer and a third refractive index layer having a third refractive index greater than the second refractive index.

20. The display device according to claim 19, wherein A refraction tilt angle formed by the refraction tilt surface and an upper surface of the substrate is smaller than a total reflection tilt angle formed by the total reflection tilt surface and the upper surface of the substrate.

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