KR102461527B1 - Both-Sides Emission Type Organic Light Emitting Diode Display Device - Google Patents

Abstract

A double-sided emission type organic light emitting diode display device of the present invention includes a first phase delay member and a first polarizing member on an upper portion of a display panel, and a second phase delay member and a second polarizing member on a lower portion of the display panel, , each of the first and second polarizing members reflects linearly polarized light in a first direction incident through an inner surface facing the display panel, and absorbs linearly polarized light in the first direction incident through an outer surface opposite to the inner surface, , Each of the first and second polarizing members transmits linearly polarized light in a second direction perpendicular to the first direction. Accordingly, it is possible to prevent reflection of external light and increase the luminance of the display device.

Description

Double-side emission type organic light emitting diode display device

The present invention relates to an organic light emitting diode display, and more particularly, to a double-sided light emitting diode display capable of reducing external light reflection and increasing luminance.

Recently, a flat panel display having excellent characteristics such as reduction in thickness, weight reduction, and low power consumption has been widely developed and applied to various fields.

Among flat panel display devices, an organic light emitting diode display device (OLED display device), also called an organic electroluminescent display device or an organic electroluminescent display device, includes a cathode and a hole as an electron injection electrode. It is a device that injects electric charges into the light emitting layer formed between the anodes, which are injection electrodes, and emits light while excitons are formed by the combination of electrons and holes, and then extinguished. Such an organic light emitting diode display can be formed on a flexible substrate such as plastic, and because it is a self-luminous type, the contrast ratio is large, and the response time is several microseconds (㎲), so moving images are realized. This is easy, there is no restriction on the viewing angle, and it is stable even at low temperatures and can be driven with a relatively low voltage of 5V to 15V of DC, so that it is easy to manufacture and design a driving circuit.

The organic light emitting diode display can be divided into a passive matrix type and an active matrix type according to the driving method. is being used

1 is a diagram showing the structure of a general organic light emitting diode display in a band diagram.

As shown in FIG. 1 , in the organic light emitting diode display device, a light emitting material layer 4 is positioned between an anode 1 which is an anode and a cathode 7 which is a cathode. . In order to inject holes from the anode 1 and electrons from the cathode 7 into the light emitting material layer 4 , between the anode 1 and the light emitting material layer 4 and between the cathode 7 and the light emitting material layer 4 ) between the hole transporting layer (hole transporting layer) (3) and the electron transporting layer (electron transporting layer) (5) is positioned. At this time, in order to more efficiently inject holes and electrons, a hole injecting layer 2 is formed between the anode 1 and the hole transport layer 3 , and electrons are disposed between the electron transport layer 5 and the cathode 7 . It further comprises an electron injecting layer (6).

In the band diagram of Figure 1, the lower line is the highest energy level of the valence band, called the highest occupied molecular orbital (HOMO), and the upper line is the lowest energy level of the conduction band, It is called the lowest unoccupied molecular orbital (LUMO). An energy difference between the HOMO level and the LUMO level becomes a band gap.

In the organic light emitting diode display having such a structure, holes (+) injected from the anode (1) to the light emitting material layer (4) through the hole injection layer (2) and the hole transport layer (3), and from the cathode (7) Electrons (-) injected into the light emitting material layer 4 through the electron injection layer 6 and the electron transport layer 5 combine to form an exciton 8, and the light emitting material from the exciton 8 A color corresponding to the band gap of the layer 4 is emitted.

Since such an organic light emitting diode display device is a self-luminous device that does not use an external light source, it is possible to simultaneously display images in both directions.

However, in general, an organic light emitting diode display has a problem in that external light reflection is severe. In particular, when the organic light emitting diode display device is used in a bright place, the luminance of the black state is increased due to reflection of external light, and the contrast ratio is lowered, so that the image quality is deteriorated.

Accordingly, various structures for blocking external light reflection have been proposed, but the conventional structure for blocking external light reflection outputs only a portion of the light emitted from the light emitting layer to the outside, thereby reducing the luminance of the display device.

In particular, since it is difficult to obtain a light extraction effect in a double-sided light emitting diode display device compared to a front or bottom emission type organic light emitting diode display device, it is difficult to improve luminance.

The present invention has been proposed to solve the above problems, and aims to improve the luminance of a double-sided light-emitting type organic light emitting diode display.

In addition, an object of the present invention is to improve image quality by blocking external light reflection of a double-sided light emitting diode display device.

In order to achieve the above object, a double-sided emission type organic light emitting diode display device of the present invention includes a first phase delay member and a first polarizing member on an upper portion of a display panel, and a second phase delay member on a lower portion of the display panel; a second polarizing member, wherein each of the first and second polarizing members reflects linearly polarized light in a first direction incident through an inner surface facing the display panel and the second polarizing member is incident through an outer surface opposite to the inner surface The linearly polarized light in one direction is absorbed, and each of the first and second polarizing members transmits the linearly polarized light in a second direction perpendicular to the first direction.

Each of the first and second polarizing members includes a plurality of reflection patterns extending in the first direction and spaced apart from each other in the second direction, and a plurality of absorption patterns respectively positioned on the plurality of reflection patterns, The polarization reflector may include a polarization reflector in which first and second layers having different refractive indices in the first direction are alternately stacked, and a polarization absorber having an absorption axis in the first direction.

The transmission axis of the first polarizing member and the transmission axis of the second polarizing member are vertical, the optical axis of the first phase delay member and the optical axis of the second phase delay member are vertical, and the transmission axis of the first polarizing member and the second The transmission axis of the polarizing member has an angle between the optical axis of the first phase delay member and the optical axis of the second phase delay member of 45 degrees.

The double-sided emission type organic light emitting diode display device according to the present invention can display images in both directions at the same time, so that the viewing range can be widened.

In addition, in the double-sided light emitting diode display device according to the present invention, by using first and second polarizing members that transmit linearly polarized light in one direction and reflect or absorb linearly polarized light perpendicular thereto, external light reflection is prevented and image quality is improved. improved, and the luminance of the display device can be increased.

In addition, it is easy to manufacture and it is possible to realize a light-weight and thin double-sided light emitting diode display device.

1 is a diagram showing the structure of a general organic light emitting diode display in a band diagram.
2 is a cross-sectional view schematically illustrating a double-sided emission type organic light emitting diode display device according to an embodiment of the present invention.
3 is a cross-sectional view schematically illustrating a display panel of a double-sided emission type organic light emitting diode display device according to an embodiment of the present invention.
4 is a cross-sectional view schematically illustrating a path of internal light emitted from a display panel of a double-sided emission type organic light emitting diode display device according to an embodiment of the present invention.
5 is a cross-sectional view schematically illustrating a path of external light incident to a double-sided emission type organic light emitting diode display device according to an embodiment of the present invention.
6 is a cross-sectional view schematically illustrating a polarizing member according to a first embodiment of the present invention.
7 is a plan view schematically illustrating a polarizing member according to a first embodiment of the present invention.
8 is a cross-sectional view schematically illustrating a polarizing member according to a second embodiment of the present invention.

A double-sided emission type organic light emitting diode display device of the present invention includes a display panel including a first electrode, a light emitting layer, and a second electrode, a first phase delay member on the display panel, and a first phase delay member on the first phase delay member a polarizing member, a second phase delay member under the display panel, and a second polarizing member under the second phase delay member, wherein each of the first and second polarizing members has an inner surface facing the display panel The linearly polarized light in the first direction incident through is reflected, and the linearly polarized light in the first direction incident through the outer surface opposite to the inner surface is absorbed, and each of the first and second polarizing members is perpendicular to the first direction. The linearly polarized light in one second direction is transmitted.

A transmission axis of the first polarizing member and a transmission axis of the second polarizing member are perpendicular to each other.

The optical axis of the first phase delay member and the optical axis of the second phase delay member are perpendicular, and the transmission axis of the first polarizing member and the transmission axis of the second polarizing member are the optical axis of the first phase delay member and the second phase delay It has an angle between the optical axis of the member and 45 degrees.

Each of the first and second polarizing members includes a plurality of reflection patterns extending in the first direction and spaced apart from each other in the second direction, and a plurality of absorption patterns respectively positioned above the plurality of reflection patterns.

In contrast, each of the first and second polarizing members includes a polarization reflector in which first and second layers having different refractive indices in the first direction are alternately stacked, and polarized light absorption having an absorption axis in the first direction. may include wealth.

Each of the first phase delay member and the second phase delay member is a quarter wave plate that converts linearly polarized light into circularly polarized light and converts circularly polarized light into linearly polarized light.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

2 is a cross-sectional view schematically illustrating a double-sided light emitting diode display device according to an embodiment of the present invention, and FIG. 3 is a schematic cross-sectional view of a display panel of the double-sided light emitting diode display device according to an embodiment of the present invention. The illustrated cross-sectional view shows one pixel area.

As shown in FIG. 2 , a double-sided emission type organic light emitting diode display device according to an embodiment of the present invention includes a display panel 100 , a first phase delay member 200a , a first polarizing member 300a , and a second It includes a phase delay member 200b, and a second polarizing member 300b.

Between the display panel 100 and the first phase delay member 200a, between the first phase delay member 200a and the first polarizing member 300a, between the display panel 100 and the second phase delay member 200b, An adhesive or an adhesive may be positioned between the second phase delay member 200b and the second polarizing member 300b, respectively.

Here, the display panel 100 may be an organic light emitting diode panel.

More specifically, referring to FIG. 3 , the organic light emitting diode panel 100 includes an insulating substrate 110 , and a patterned semiconductor layer 122 is formed on the insulating substrate 110 . The substrate 110 may be a glass substrate or a plastic substrate. The semiconductor layer 122 may be formed of an oxide semiconductor material. Alternatively, the semiconductor layer 122 may be made of polycrystalline silicon, and in this case, both edges of the semiconductor layer 122 may be doped with impurities.

A gate insulating layer 130 made of an insulating material is formed on the semiconductor layer 122 over the entire surface of the substrate 110 . The gate insulating layer 130 may be formed of an inorganic insulating material such as silicon oxide (SiO ₂ ). When the semiconductor layer 122 is made of polycrystalline silicon, the gate insulating layer 130 may be formed of silicon oxide (SiO ₂ ) or silicon nitride (SiNx).

A gate electrode 134 made of a conductive material such as metal is formed on the gate insulating layer 130 to correspond to the center of the semiconductor layer 122 . In addition, a gate wiring (not shown) and a first capacitor electrode (not shown) are formed on the gate insulating layer 130 . Although not shown, the gate wiring extends in one direction, and the first capacitor electrode is connected to the gate electrode 134 .

Meanwhile, in the embodiment of the present invention, the gate insulating layer 130 is formed on the entire surface of the substrate 110 , but the gate insulating layer 130 may be patterned in the same shape as the gate electrode 134 .

An interlayer insulating layer 140 made of an insulating material is formed on the entire surface of the substrate 110 on the gate electrode 134 , the gate wiring, and the first capacitor electrode. The interlayer insulating layer 140 may be formed of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx), or an organic insulating material such as benzocyclobutene or photo acryl. .

The interlayer insulating layer 140 has first and second contact holes 140a and 140b exposing upper surfaces of both sides of the semiconductor layer 122 . The first and second contact holes 140a and 140b are positioned at both sides of the gate electrode 134 to be spaced apart from the gate electrode 134 . Here, the first and second contact holes 140a and 140b are also formed in the gate insulating layer 130 . In contrast, when the gate insulating layer 130 is patterned to have the same shape as the gate electrode 134 , the first and second contact holes 140a and 140b are formed only in the interlayer insulating layer 140 .

Source and drain electrodes 152 and 154 made of a conductive material such as metal are formed on the interlayer insulating layer 140 . In addition, a data line (not shown) and a second capacitor electrode (not shown) are formed on the interlayer insulating layer 140 .

The source and drain electrodes 152 and 154 are spaced apart from the center of the gate electrode 134 and contact both sides of the semiconductor layer 122 through the first and second contact holes 140a and 140b, respectively. Although not shown, the data line extends along a direction crossing the gate line and crosses the gate line to define a pixel area. The second capacitor electrode is connected to the source electrode 152 , and overlaps the first capacitor electrode to form a storage capacitor using the interlayer insulating layer 140 therebetween as a dielectric.

In this case, a power supply wiring (not shown) may be further formed on the interlayer insulating layer 140 , and the power supply wiring supplying a high potential voltage may be spaced apart from the data wiring.

Meanwhile, the semiconductor layer 122 , the gate electrode 134 , and the source and drain electrodes 152 and 154 form a thin film transistor. Here, the thin film transistor has a coplanar structure in which a gate electrode 134 and source and drain electrodes 152 and 154 are positioned on one side of the semiconductor layer 122 , that is, on the semiconductor layer 122 .

Alternatively, the thin film transistor may have an inverted staggered structure in which a gate electrode is positioned under the semiconductor layer and source and drain electrodes are positioned above the semiconductor layer. In this case, the semiconductor layer may be made of amorphous silicon.

Here, the thin film transistor corresponds to a driving thin film transistor of the organic light emitting diode panel 100 , and a switching thin film transistor (not shown) having the same structure as the driving thin film transistor is further formed on the substrate 110 . The gate electrode 134 of the driving thin film transistor is connected to a drain electrode (not shown) of the switching thin film transistor, and the source electrode 152 of the driving thin film transistor is connected to a power supply line (not shown). In addition, a gate electrode (not shown) and a source electrode (not shown) of the switching thin film transistor are respectively connected to the gate wiring and the data wiring.

A passivation layer 160 made of an insulating material is formed over the entire surface of the substrate 110 on the source and drain electrodes 152 and 154 , the data line, and the second capacitor electrode. The passivation layer 160 has a flat top surface and has a drain contact hole 160a exposing the drain electrode 154 . Here, the drain contact hole 160a is illustrated as being formed directly above the second contact hole 140b, but may be formed to be spaced apart from the second contact hole 140b.

The passivation layer 160 may be formed of an organic insulating material such as benzocyclobutene or photoacrylic.

The first electrode 162 is formed of a conductive material having a relatively high work function on the passivation layer 160 . The first electrode 162 is formed for each pixel area and contacts the drain electrode 154 through the drain contact hole 160a. For example, the first electrode 162 may be formed of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

A bank layer 170 made of an insulating material is formed on the first electrode 162 . The bank layer 170 covers the edge of the first electrode 162 and has a through hole 170a exposing the first electrode 162 .

Here, the bank layer 170 covers a portion of the thin film transistor, more specifically, the drain electrode 154 , but the bank layer 170 may completely cover the thin film transistor.

A light-emitting layer 172 is formed on the first electrode 162 exposed through the transmission hole 170a of the bank layer 170 . The light-emitting layer 172 includes a light-emitting material layer.

In addition, the light emitting layer 172 further includes a hole injecting layer and a hole transporting layer sequentially stacked from the top of the first electrode 162 between the first electrode 162 and the light emitting material layer. and may further include an electron transporting layer and an electron injecting layer sequentially stacked on the light emitting material layer.

A second electrode 182 made of a conductive material having a relatively low work function is substantially formed on the entire surface of the substrate 110 on the emission layer 172 . Here, the second electrode 182 may be formed of aluminum, magnesium, silver, or an alloy thereof. The second electrode 182 may have a relatively thin thickness to allow light to pass therethrough.

The first electrode 162 , the light emitting layer 172 , and the second electrode 182 form an organic light emitting diode De, the first electrode 162 serves as an anode, and the second electrode 182 . acts as a cathode.

Alternatively, the first electrode 162 may be made of a conductive material having a relatively low work function to serve as a cathode, and the second electrode 182 may be made of a conductive material having a relatively high work function to serve as an anode.

Next, the encapsulation layer 192 is substantially formed on the entire surface of the substrate 110 on the second electrode 182 , and the opposing substrate 190 is disposed on the encapsulation layer 192 .

The encapsulation layer 192 may be a face seal using a sealing material or may have a structure in which several layers of inorganic/organic/inorganic layers are stacked. The encapsulation layer 192 prevents external moisture from penetrating into the organic light emitting diode De to prevent damage to the organic light emitting diode De.

Here, the encapsulation layer 192 may be formed on the opposing substrate 190 , and after the encapsulation layer 192 is formed on the opposing substrate 190 , the encapsulation layer 192 and the second electrode ( The opposing substrate 190 and the substrate 110 may be bonded to each other so that the 182 is in contact.

On the other hand, after the encapsulation layer 192 is directly formed on the second electrode 182 , the opposite substrate 190 is disposed on the encapsulation layer 192 , thereby forming the opposite substrate 190 and the substrate 110 . ) may be combined.

Referring back to FIG. 2 , the first phase delay member 200a is positioned on the first surface, that is, the upper surface of the display panel 100 , and the first polarizing member 300a is positioned on the upper surface of the first phase delay member 200a. is located In addition, the second phase delay member 200b is positioned on the second surface, that is, the lower surface of the display panel 100 , and the second polarizing member 300b is positioned on the lower surface of the second phase delay member 200b.

Each of the first phase delay member 200a and the second phase delay member 200b is a quarter wave plate (QWP) that has a phase delay of λ/4 to change the polarization state of the incident light by 90 degrees can At this time, each of the first phase delay member 200a and the second phase delay member 200b may have a phase delay value greater than or equal to 95 nm and less than or equal to 195 nm, preferably greater than 130 nm. It may have a phase delay value equal to or less than 150 nm. Accordingly, the linearly polarized light passing through each of the first phase delay member 200a and the second phase delay member 200b is changed to circularly polarized light, and each of the first phase delay member 200a and the second phase delay member 200b Circularly polarized light passing through is converted to linearly polarized light.

For example, each of the first phase delay member 200a and the second phase delay member 200b may be formed in the form of a film by stretching a cyclic olefin polymer (COP). Alternatively, each of the first phase delay member 200a and the second phase delay member 200b may be formed by coating and polymerizing a liquid crystal material, but is not limited thereto.

Meanwhile, each of the first polarizing member 300a and the second polarizing member 300b may be a linear polarizing plate. Each of the first polarizing member 300a and the second polarizing member 300b absorbs or reflects the linearly polarized light in a specific direction, and transmits the linearly polarized light in a direction perpendicular thereto. In more detail, each of the first polarizing member 300a and the second polarizing member 300b reflects linearly polarized light in one direction that is incident through the inner surface facing the display panel 100 and is incident through the outer surface opposite to the inner surface. Linearly polarized light in one direction is absorbed.

Here, the reflection axis of the first polarizing member 300a and the reflection axis of the second polarizing member 300b are preferably perpendicular to each other, and the first polarizing member 300a and the second polarizing member 300b are parallel to the reflection axis. It can have one absorption axis. In addition, it is preferable that the optical axis of the first phase delay member 200a and the optical axis of the second phase delay member 200b are perpendicular to each other.

In this case, the reflection axis of the first polarizing member 300a may be greater than or equal to -20 degrees and less than or equal to 20 degrees, and preferably, greater than or equal to -5 degrees and less than or equal to 5 degrees. In addition, the optical axis of the first phase delay member 200a may be greater than or equal to 30 degrees and less than or equal to 60 degrees, and preferably, greater than or equal to 40 degrees and less than or equal to 50 degrees.

For example, the reflection axis of the first polarizing member 300a may be 0 degrees, and the optical axis of the first phase delay member 200a may be 45 degrees. In addition, the optical axis of the second phase delay member 200b may be -45 degrees, and the reflection axis of the second polarizing member 300b may be 90 degrees.

The double-sided emission type organic light emitting diode display device according to the embodiment of the present invention outputs light through each of the upper and lower surfaces of the display panel 100, so that images can be displayed in both directions at the same time, thereby widening the viewing range. have.

In addition, the double-sided emission type organic light emitting diode display device according to the embodiment of the present invention can block reflection of external light in both directions and improve luminance. This will be described in detail with reference to FIGS. 4 and 5 .

4 is a cross-sectional view schematically illustrating a path of internal light emitted from a display panel of a double-sided emission type organic light emitting diode display device according to an embodiment of the present invention, and FIG. 5 is a double side emission type organic light emitting diode display according to an embodiment of the present invention. It is a cross-sectional view schematically illustrating a path of external light incident on a diode display device.

Here, the first polarizing member 300a has a transmission axis in a first direction, a reflection axis in a second direction perpendicular to the first direction, and the second polarizing member 300b has a transmission axis in the second direction, and It has a directional reflection axis. Accordingly, when the reflection axis of the first polarizing member 300a is 0 degrees and the reflection axis of the second polarizing member 300b is 90 degrees, the transmission axis of the first polarizing member 300a is 90 degrees, and the second polarizing member 300b is 90 degrees. The transmission axis of (300b) is 0 degrees. In addition, the optical axis of the first phase delay member 200a is 45 degrees, and the optical axis of the second phase delay member 200b is -45 degrees. In this case, the first and second polarizing members 300a and 300b may have absorption axes parallel to the reflection axis, reflect light incident on the inner surface facing the display panel 100 , and reflect light incident on the outer surface opposite to the inner surface. absorbs light

As shown in FIG. 4 , internal light emitted from the light emitting layer ( 172 in FIG. 3 ) of the display panel 100 and passing through the upper surface of the display panel 100 passes through the first phase delay member 200a to be first polarized light. It is incident on the inner surface of the member 300a. Among the inner light incident on the inner surface of the first polarizing member 300a, the linearly polarized light oscillating in the first direction coincides with the transmission axis of the first polarizing member 300a, so it passes through the first polarizing member 300a and is output to the outside . On the other hand, among the inner light incident on the inner surface of the first polarizing member 300a, the linearly polarized light vibrating in the second direction coincides with the reflection axis of the first polarizing member 300a and is reflected by the first polarizing member 300a, While passing through the first phase delay member 200a, a right circularly polarized state reaches the display panel 100 . Then, some of the inner light reaching the display panel 100 is reflected by the display panel 100 to become a left circularly polarized state, and passes through the first phase delay member 200a again to become a linearly polarized state in the first direction. It reaches the polarizing member 300a, and since it coincides with the transmission axis of the first polarizing member 300a, it passes through the first polarizing member 300a and is output to the outside. On the other hand, the rest of the inner light reaching the display panel 100 passes through the display panel 100 as it is to maintain the right circularly polarized state, and passes through the second phase delay member 200b to become the linearly polarized state in the second direction. It arrives at the second polarizing member 300b, and since it coincides with the transmission axis of the second polarizing member 300b, it passes through the second polarizing member 300b and is output to the outside.

In addition, internal light emitted from the light emitting layer ( 172 in FIG. 3 ) of the display panel 100 and passing through the lower surface of the display panel 100 passes through the second phase delay member 200b to the inner surface of the second polarizing member 300b. is entered into Among the inner light incident on the inner surface of the second polarizing member 300b, the linearly polarized light oscillating in the second direction coincides with the transmission axis of the second polarizing member 300b, and thus passes through the second polarizing member 300b and is output to the outside. . On the other hand, among the inner light incident on the inner surface of the second polarizing member 300b, the linearly polarized light vibrating in the first direction coincides with the reflection axis of the second polarizing member 300b and is reflected by the second polarizing member 300b, While passing through the second phase delay member 200b, the left circularly polarized state reaches the display panel 100 . Then, some of the internal light reaching the display panel 100 is reflected by the display panel 100 to become a right circularly polarized state, and passes through the second phase delay member 200b again to become a linearly polarized state in the second direction. It arrives at the polarizing member 300b, and since it coincides with the transmission axis of the second polarizing member 300b, it passes through the second polarizing member 300b and is output to the outside. On the other hand, the rest of the internal light reaching the display panel 100 passes through the display panel 100 as it is to maintain the left circularly polarized state, and passes through the first phase delay member 200a to become linearly polarized in the first direction. It reaches the first polarizing member 300a, and since it coincides with the transmission axis of the first polarizing member 300a, it passes through the first polarizing member 300a and is output to the outside.

Here, the internal light reflected from the display panel 100 may be reflected from the signal wiring of the display panel 100 , and may also be reflected from the first electrode ( 162 in FIG. 3 ) and/or the second electrode ( 182 in FIG. 3 ). can

As such, in the double-sided emission type organic light emitting diode display device according to the embodiment of the present invention, among the internal light emitted from the display panel 100 , not only the linearly polarized light parallel to the transmission axis of the first and second polarizing members 300a and 300b but also the internal light emitted from the display panel 100 . Rather, since the linearly polarized light perpendicular to the transmission axis of the first and second polarizing members 300a and 300b is also reflected by the first and second polarizing members 300a and 300b and output to the outside, the luminance of the display device can be increased. have.

Meanwhile, as shown in FIG. 5 , among the external light incident on the outer surface of the first polarizing member 300a from the top of the display device of the present invention, the linearly polarized light oscillating in the first direction is transmitted through the first polarizing member 300a. Since it coincides with the axis, it passes through the first polarizing member 300a and passes through the first phase delay member 200a to become left circularly polarized and arrives at the display panel 100 . Then, some of the external light reaching the display panel 100 is reflected by the display panel 100 to be in a right circularly polarized state, and passes through the first phase delay member 200a again to be in a linearly polarized state in the second direction. It reaches the polarizing member 300a, and is blocked without passing through the first polarizing member 300a because it is perpendicular to the transmission axis of the first polarizing member 300a. On the other hand, the rest of the external light reaching the display panel 100 passes through the display panel 100 as it is to maintain the left circularly polarized state, and passes through the second phase delay member 200b to become linearly polarized in the first direction. It reaches the second polarizing member 300b, and is blocked without passing through the second polarizing member 300b because it is perpendicular to the transmission axis of the second polarizing member 300b. On the other hand, among the external light incident on the outer surface of the first polarizing member 300a, linearly polarized light vibrating in the second direction coincides with the absorption axis of the first polarizing member 300a, and thus is absorbed by the first polarizing member 300a.

In addition, among the external light incident on the outer surface of the second polarizing member 300b from the lower part of the display device of the present invention, the linearly polarized light oscillating in the second direction coincides with the transmission axis of the second polarizing member 300b, and thus the second polarizing member After passing through 300b and passing through the second phase delay member 200b, a right circularly polarized state reaches the display panel 100 . Then, some of the external light reaching the display panel 100 is reflected by the display panel 100 to become a left circularly polarized state, and passes through the second phase delay member 200b again to become a linearly polarized state in the first direction. It reaches the polarizing member 300b, and is blocked without passing through the second polarizing member 300b because it is perpendicular to the transmission axis of the second polarizing member 300b. On the other hand, the rest of the external light reaching the display panel 100 passes through the display panel 100 as it is to maintain the right circularly polarized state, and passes through the first phase delay member 200a to become linearly polarized in the second direction. It reaches the first polarizing member 300a, and is blocked without passing through the first polarizing member 300a because it is perpendicular to the transmission axis of the first polarizing member 300a. On the other hand, among the external light incident on the outer surface of the second polarizing member 300b, linearly polarized light vibrating in the first direction coincides with the absorption axis of the second polarizing member 300b, and thus is absorbed by the second polarizing member 300b.

Here, external light reflected from the display panel 100 may be reflected from the signal wiring of the display panel 100 , and may also be reflected from the first electrode ( 162 in FIG. 3 ) and/or the second electrode ( 182 in FIG. 3 ). can

As described above, in the double-sided emission type organic light emitting diode display device according to the embodiment of the present invention, among the external light incident on the outer surfaces of the first and second polarizing members 300a and 300b, the first and second polarizing members 300a, Not only the linearly polarized light perpendicular to the transmission axis of 300b), but also the linearly polarized light parallel to the transmission axis of the first and second polarizing members 300a and 300b is blocked by the first and second polarizing members 300a and 300b to the outside. Since the output can be prevented, the image quality can be improved by preventing reflection of external light.

The polarizing member used in the double-sided emission type organic light emitting diode display according to the embodiment of the present invention will be described in more detail with reference to the drawings.

-First embodiment-

6 is a cross-sectional view schematically showing a polarizing member according to a first embodiment of the present invention, and FIG. 7 is a plan view schematically showing a polarizing member according to a first embodiment of the present invention.

6 and 7, the polarizing member 300 according to the first embodiment of the present invention includes a base film 310, a polarization reflection unit 312, a polarization absorption unit 314, and a protective layer ( 316).

The base film 310 is made of a transparent material, and is made of an amorphous thermoplastic resin including poly(methyl methacrylate) (PMMA) and polycarbonate (PC), or polyethylene terephthalate (polyethylene terephthalate). : PET) may be made of a crystalline thermoplastic resin. Alternatively, the base film 310 may be an inorganic substrate such as glass.

A polarization reflection unit 312 is formed on the base film 310 , and the polarization reflection unit 312 includes a plurality of reflection patterns extending in one direction and spaced apart from each other in a direction perpendicular to the one direction. The reflection pattern may be made of a metal material having a relatively high reflectance. For example, the reflective pattern may be made of aluminum, and the material of the reflective pattern is not limited thereto.

Here, the pitch p of the reflective pattern, that is, the distance from one side of one reflective pattern to one side of the adjacent reflective pattern including the other side of one reflective pattern may be greater than or equal to 50 nm and less than or equal to 300 nm. . The pitch p of the reflection pattern may be defined as a distance between the centers of two adjacent reflection patterns. In addition, the height h of the reflection pattern may be greater than or equal to 50 nm and less than or equal to 200 nm, and the width w of the reflection pattern may be greater than or equal to 30 nm and less than or equal to 150 nm.

The polarization absorbing part 314 is positioned above the polarization reflecting part 312 . The polarization absorption unit 314 includes a plurality of absorption patterns respectively positioned above the reflection pattern. The absorption pattern has the same shape as the reflection pattern, and preferably has the same width and pitch. The absorption pattern may be formed of a material that absorbs light, and for example, the absorption pattern may be formed of a black resin. Alternatively, the absorption pattern may be formed of several types of dyes that absorb light of different colors.

A protective layer 316 is positioned on the polarization absorbing part 314 , and the protective layer 316 covers the polarization absorbing part 314 , the polarization reflecting part 312 , and the base film 310 to protect them. The protective layer 316 may be made of an acrylic resin.

The polarizing member 300 according to the first embodiment of the present invention reflects light that vibrates in a direction parallel to the extension direction of the reflection pattern among the light incident to the polarization reflecting unit 312 through the base film 310 . and transmits light vibrating in a direction perpendicular to the extension direction of the reflection pattern. In addition, the polarization member 300 according to the first embodiment of the present invention emits light that vibrates in a direction parallel to the extension direction of the absorption pattern among the light incident to the polarization absorption unit 314 through the protective layer 316 . It absorbs and transmits light vibrating in a direction perpendicular to the extension direction of the absorption pattern.

-Second embodiment-

8 is a cross-sectional view schematically illustrating a polarizing member according to a second embodiment of the present invention.

As shown in FIG. 8 , the polarization member 300 according to the second embodiment of the present invention includes a polarization reflection unit 322 and a polarization absorption unit 324 .

The polarization reflector 322 has a structure in which a first layer 322a and a second layer 322b are alternately stacked. The first layer 322a and the second layer 322b have the same refractive index in one direction, and have different first and second refractive indices n1 and n2 in a direction perpendicular thereto. The polarization reflector 322 may be formed by simultaneously extruding materials having different refractive indices, but is not limited thereto.

Meanwhile, the polarization absorption unit 324 includes an absorption layer 324a and a passivation layer 324b , and the absorption layer 324a is positioned between the passivation layer 324b and the polarization reflection unit 322 . Here, the polarization absorption unit 324 may further include a protective layer between the absorption layer 324a and the polarization reflection unit 322 .

The absorption layer 324a may be formed of polyvinyl alcohol (PVA) that is stretched by dyeing iodine ions or dichroic dyes.

The protective layer 324b may be formed of one selected from tri-acetyl cellulose (TAC), cyclic olefin polymer (COP), and polyethylene terephthalate (PET).

Alternatively, the absorption layer 324a may be formed of a reactive mesogen (RM) and a dichroic dye. In this case, the polarization absorption unit 324 further includes an alignment layer for arranging the reactive mesogen and the dichroic dye. can do.

The polarizing member 300 according to the second embodiment of the present invention vibrates in one direction in which the refractive indices of the first layer 322a and the second layer 322b among the light incident to the polarization reflecting unit 322 are the same. Light is transmitted, and light that vibrates in directions having different refractive indices of the first layer 322a and the second layer 322b is reflected. In addition, the polarizing member 300 according to the second embodiment of the present invention absorbs light that vibrates in a direction parallel to the absorption axis of the absorption layer 324a among the light incident on the polarization absorption unit 324, and the absorption layer ( 324a) transmits light vibrating in a direction perpendicular to the absorption axis.

Although the above has been described with reference to the preferred embodiment of the present invention, those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention described in the claims below. You will understand that it can be done.

100: display panel 210a: first phase delay member
200b: second phase delay member 300a: first polarizing member
300b: second polarizing member 110: substrate
122: semiconductor layer 130: gate insulating film
134: gate electrode 140: interlayer insulating film
140a, 140b: first and second contact holes 152: source electrode
154: drain electrode 160: protective film
160a: drain contact hole 162: first electrode
170: bank layer 170a: through hole
172: light emitting layer 182: second electrode
De: organic light emitting diode 190: counter substrate
192: encapsulation layer

Claims (7)

a display panel including a first electrode, a light emitting layer, and a second electrode;
a first phase delay member on the display panel;
a first polarizing member on the first phase delay member;
a second phase delay member under the display panel;
a second polarizing member under the second phase delay member
includes,
Each of the first and second polarizing members reflects the linearly polarized light in the first direction incident through the inner surface facing the display panel, and absorbs the linearly polarized light in the first direction incident through the outer surface opposite to the inner surface,
Each of the first and second polarizing members transmits linearly polarized light in a second direction perpendicular to the first direction,
Each of the first and second polarizing members includes a plurality of reflective patterns extending in the first direction and spaced apart from each other in the second direction, and a plurality of absorption patterns respectively positioned above the plurality of reflective patterns,
The plurality of absorption patterns is a double-sided emission type organic light emitting diode display comprising a black resin or various kinds of dyes that absorb light of different colors.
According to claim 1,
A double-sided light emitting diode display device in which a transmission axis of the first polarizing member and a transmission axis of the second polarizing member are perpendicular.
3. The method of claim 2,
The optical axis of the first phase delay member and the optical axis of the second phase delay member are perpendicular, and the transmission axis of the first polarizing member and the transmission axis of the second polarizing member are the optical axis of the first phase delay member and the second phase delay A double-sided light-emitting type organic light emitting diode display having an angle between the member's optical axis and an optical axis of 45 degrees.
According to claim 1,
Each of the first and second polarizing members further includes a protective layer on the plurality of absorption patterns, wherein the protective layer emits light from both sides in contact with side surfaces of the plurality of reflection patterns and side surfaces of the plurality of absorption patterns. type organic light emitting diode display.
5. The method of claim 4,
Each of the first and second polarizing members further includes a base film under the plurality of reflective patterns, and the protective layer is in contact with an upper surface of the base film.
6. The method according to any one of claims 1 to 5,
Each of the first phase delay member and the second phase delay member is a quarter wave plate for converting linearly polarized light into circularly polarized light and converting circularly polarized light into linearly polarized light.
According to claim 1,
A thickness of the plurality of absorption patterns is smaller than a thickness of the plurality of reflection patterns.

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