KR101957270B1 - Quantum rod luminescent display device - Google Patents

Abstract

A quantum rod panel including first and second substrates facing each other and a quantum rod layer interposed between the first and second substrates and having a plurality of quantum rods arranged in one direction; A backlight unit provided under the quantum rod panel; And a backlight unit disposed between the quantum rod panel and the backlight unit for receiving and polarizing non-polarized light emitted from the backlight unit and providing polarization to the quantum rod panel, Wherein the polarized light is passed through the opposite surface of the polarized light reproducing film.

Description

[0001] The present invention relates to a quantum rod luminescent display device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quantum rod light emitting display, and more particularly, to a quantum rod light emitting display capable of maximizing light efficiency and suppressing light leakage.

2. Description of the Related Art Flat panel displays having excellent characteristics such as thinning, lightening, and low power consumption have been widely developed and applied to various fields.

As a representative flat panel display device, a liquid crystal display device has been widely used and widely used.

However, referring to FIG. 1 (a diagram showing a schematic sectional configuration of a general liquid crystal display device), a liquid crystal display device includes first and second substrates (not shown), an alignment film (not shown), a color filter layer A liquid crystal panel 10 including a liquid crystal layer (not shown), a backlight unit 20 including a light source 21, a reflection plate 22 and a plurality of optical films 23, 32).

That is, the liquid crystal display device 1 requires a plurality of optical films 22 and polarizing plates 31 and 32 for gray level implementation, and in order to express color, (Not shown).

Therefore, the light emitted from the light source 21 of the backlight unit 20 is mostly lost through the optical film 23, the color filter layer (not shown) and the polarizing plates 31 and 32, resulting in a decrease in transmittance have.

That is, when the amount of light emitted from the light source 21 of the backlight unit 20 is 101, the amount of light finally transmitted through the liquid crystal display device 1 is about 5 to 10, so that the transmission efficiency is very low, The brightness of light emitted from the backlight unit 20 must be increased for realizing a proper luminance, so that power consumption is increased, and furthermore, the number of parts required for manufacturing is increased, which makes it difficult to reduce the manufacturing cost.

Therefore, recently, a new flat panel display device which can solve the problem of low transmittance of the liquid crystal display device 1 to reduce the power consumption and reduce the manufacturing cost due to relatively small components is required.

Meanwhile, an organic electroluminescent device has been proposed, which does not require a separate polarizing plate, a color filter layer and an optical film in response to demands of the time.

Such an organic electro luminescent device is a device which injects electric charge into an organic light emitting layer formed between a cathode which is an electron injection electrode and a cathode which is a hole injection electrode, and pairs electrons and holes and then extinguishes while emitting light.

Such an organic electroluminescent device can be formed not only on a flexible substrate such as a plastic but also has excellent color sensitivity due to self-luminescence and can be driven at a lower voltage (10 V or less) than a liquid crystal display device, Is relatively small.

However, such an organic electroluminescent device has a large difference in the lifetime of the organic luminescent material of the organic luminescent layer from one color to another. In particular, the blue luminescent material has a relatively small lifetime, .

Therefore, there is a demand for a flat panel display device having a high transmittance, capable of driving a low power consumption and having a lifetime at the level of a liquid crystal display device.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a liquid crystal display device which has a large transmission efficiency without requiring a polarizing plate, The purpose is to provide.

Another object of the present invention is to provide a display device capable of maximizing utilization efficiency of light emitted from a backlight unit.

A quantum rod light emitting display according to an embodiment of the present invention includes first and second substrates facing each other and a quantum rod layer interposed between the first and second substrates and having a plurality of quantum rods arranged in one direction A quantum road panel comprising: A backlight unit provided under the quantum rod panel; And a backlight unit disposed between the quantum rod panel and the backlight unit for receiving and polarizing non-polarized light emitted from the backlight unit and providing polarization to the quantum rod panel, And passing the light through the opposite face.

At this time, the direction is perpendicular to the polarization axis of the light polarized in one direction in which the plurality of quantum rods are arranged and in a specific direction passing through the polarized reproduction film.

The first substrate is provided with first, second and third pixel regions that exhibit red, green, and blue colors. The quantum rod layer includes quantum rods having different-sized cores for the first, second, and third pixel regions, Wherein the second substrate is provided with red, green, and blue color filter patterns corresponding to the first, second, and third pixel regions, respectively.

The first substrate is provided with first, second and third pixel regions for red, green and blue. The quantum rod layer has a quantum rod having a core of the same size in each pixel region. The substrate is provided with red, green, and blue color filter patterns corresponding to the first, second, and third pixel regions.

In addition, the quantum rod layer may be formed separately on the first substrate for each pixel region, or may be formed on the entire surface of the display region for displaying an image.

A gate wiring and a data wiring crossing the first substrate to define the pixel regions; And a thin film transistor connected to the gate wiring and the data wiring. The first electrode is connected to the drain electrode of the thin film transistor.

The fact that the plurality of quantum rods are arranged in one direction means that the intensity of the light emitted from the light source is I, the light having only the horizontal component is I _h , the light having only the vertical component is I _v , When PR _h and polarization ratio PR _v in the vertical direction are defined as PR _h = I _h / (I _h + I _v ) and PR _v = I _v / (I _h + I _v ), respectively, PR _h or the polarization ratio PR _v in the vertical direction is larger than 0.5 and smaller than 1, that is, 0.5 <PR _h (or PR _v ) <1.

The quantum rod is composed of a core alone or comprises a core and a shell surrounding the core. The shell has a shape having a minor axis and a major axis, and a ratio of minor axis to major axis is 1: 1.1 to 1:30 Wherein the quantum rod has one of a spherical shape, an elliptical shape, a polyhedral shape, and a rod shape, and the shell has a shape in which the cut surface cut in the direction of the short axis of the quantum rod is a circle, ellipse, And has a single-layer structure or a multi-layer structure.

The shell is made of an alloy, an oxide-based material, or an impurity-doped material.

CdSe, CdS, CdTe, ZnO, and the like, when the core is made of a group II-VI, and the core is made of semiconductors, alloys or mixed materials of II-VI, III-V, III-VI, VI- InP, InN, GaN, InSb, InAsP, InGaAs, GaAs, InGaAs, ZnSe, ZnS, ZnTe, HgSe, HgTe, and CdZnSe, or a material in which two or more materials are mixed. PbSe, PbTe, PbS, PbSnTe, Tl, PbSnTe, PbSnTe, PbSnTe, PbSnTe, PbSnTe, PbSnTe, and PbSnTe are formed of any one material selected from the group consisting of GaP, GaP, GaSb, AlP, AlN, AlAs, AlSb, CdSeTe and ZnCdSe, or a mixture of two or more materials. ₂ is characterized by any one or SnTe ₅ made of, or consisting of two or more materials are mixed material.

The backlight unit may include an edge type backlight unit including a reflective plate, a light guide plate disposed on the reflective plate, and a light source positioned on a side of the light guide plate, or a reflective plate, a plurality of light sources positioned on the reflective plate, And a diffusing plate positioned above the light source of the direct light type backlight unit.

In addition, the backlight unit generates blue or ultraviolet light having a short wavelength of 430 nm or less.

The quantum rod display device according to an embodiment of the present invention does not require a polarizing plate and thus has a polarizing plate to reduce luminance characteristics and to provide a liquid crystal display There is an effect that the device has high luminance characteristics and low power consumption characteristics.

Further, since quantum rods having different sizes of cores for displaying red, green, and blue are provided, materials having different physical properties are used to display red, green, and blue colors as in an organic electroluminescent device, There is no car, and the duration of fluorescence characteristic relative to the substance emitting light by itself is relatively large, which has an effect of longevity.

Further, since the polarized reproduction film is provided, the characteristic of the quantum rod that absorbs the light polarized in one direction can be better utilized, so that the amount of light is increased to further improve the luminance characteristic.

Further, by providing a polarized reproduction film, it is possible to suppress light leakage compared to a quantum rod light emitting display device not having the polarizing film, thereby improving the display quality.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic sectional view of a general liquid crystal display device. Fig.
2 illustrates a form of a quantum rod;
FIG. 3 is a diagram showing the states of electrons and electrons before and after the application of an electric field to the quantum rod. FIG.
4 is a cross-sectional view of a quantum rod light emitting display device according to an embodiment of the present invention.
5A to 5C are sectional views of a quantum rod light emitting display device according to Modification 1, 2, or 3 of the embodiment of the present invention.
FIG. 6 is a diagram showing only a backlight unit and a quantum rod layer in a quantum rod light emitting display device without a polarized reproduction film as a comparative example, together with the progress of light according to the off and on states of an electric field.
FIG. 7 is a view illustrating only a backlight unit, a polarized light reproduction film, and a quantum rod layer in a quantum rod light emitting display according to an embodiment of the present invention. FIG. 7 also shows progress of light according to off and on states of an electric field.

Hereinafter, a quantum rod light emitting display according to the present invention will be described in detail with reference to the accompanying drawings.

First, the quantum rod used in the present invention will be briefly described.

2, which is a diagram illustrating a general form of a quantum rod, a quantum rod 156 includes a core 157 and a shell (not shown) 158). The quantum rod 156 may include a core 157 and a shell 158 surrounding the core 157. The shell 158 may be omitted and only the core 157 may be formed.

The core 157 may have a spherical shape, an elliptical shape, a polyhedron, or a rod shape, and the core 157 of the quantum 156 may have a spherical shape.

In the meantime, when the quantum rod 156 is formed of only the core 157 without the shell 158, the core 157 has an elliptical shape or a rod shape.

When the quantum rod includes the core 157 and the shell 158 surrounding the core 157, the core 157 may have any of spherical, ellipsoidal, polyhedral, and rod shapes. And the shell 158 surrounding it has a major axis and a minor axis, and the cut surface cut in the minor axis direction of the quantum rod 156 may take any one of circular, elliptical, and polygonal shapes.

The shell 158 may have a single layer or a multi-layer structure and is formed of a material in which any one or a mixture of two or more of an alloy, an oxide-based material, or an impurity-doped material is mixed.

At this time, the shell 158 is characterized in that the ratio of the major axis to the minor axis has a range of 1: 1.1 to 1:30, so that the shell 158 can have various ratios.

The core 157 of the quantum rod 156 may be formed of a semiconductor material, an alloy, or a mixed material of Group II-VI, III-V, III-VI, IV-VI, and IV of the periodic table.

That is, when the core 157 of the quantum rod 156 is made of the II-VI materials of the periodic table, any of CdSe, CdS, CdTe, ZnO, ZnSe, ZnS, ZnTe, HgSe, HgTe, CdZnSe, CdSeTe, and ZnCdSe One or more materials may be mixed.

In the case of the III-V group, any one or more of InP, InN, GaN, InSb, InAsP, InGaAs, GaAs, GaP, GaSb, AlP, AlN, AlAs and AlSb may be mixed.

In addition, there is any one or two or more of the case made of a Ⅵ-Ⅳ group, PbSe, PbTe, PbS, PbSnTe, Ti ₂ SnTe ₅ may be mixed.

The quantum rod 156 made of such a material and having a ratio of the minor axis to the major axis of 1: 1.1 to 1:30 is composed of the core 157 of the same material. However, Is different.

That is, as the size (or the diameter) of the core 157 is reduced, the light having a shorter wavelength is fluoresced, and as the size (or diameter) of the core 157 is larger, the longer wavelength light is fluoresced.

therefore. The quantum rod 156 is capable of displaying almost all the light of the visible light region having a desired color by adjusting the size (or diameter) of the core 157.

The quantum rod 156 having such a characteristic has a structure in which the quantum rod 156 having the characteristics shown in FIG. 3 (the electron and the major state before the electric field is applied to the quantum rod (the electric field on state) 157 itself or the shell 158 surrounding the core 157 has a major axis and a minor axis.

Therefore, before the electric field is applied in the long axis direction of the shell 158 or the core 157 having the long axis and the short axis, electrons and holes are coupled into the core 157, Electrons e and holes h are spatially separated in the core 157 or between the core 157 and the shell 158 when an electric field is applied in the longitudinal direction of the core 157 to induce separation of the band gap. Thereby enabling the amount of light to be emitted from the quantum rod 156 to be adjusted, thereby achieving a gray level by adjusting the intensity of the electric field.

This quantum rod 156 has a quantum yield of 101% in theory, which is another characteristic that it can generate very high fluorescence.

Hereinafter, the configuration of the quantum rod light emitting display device according to the embodiment of the present invention using the quantum rod 156 having the above-described characteristics will be described.

FIG. 4 is a cross-sectional view of a quantum rod light emitting display device according to an embodiment of the present invention. In FIG. 4, three neighboring pixel regions are shown, and a thin film transistor Tr is shown only for one pixel region P for convenience. At this time, a region where the thin film transistor Tr is provided in each pixel region P is defined as a switching region TrA.

As shown, the quantum rod light emitting display 101 according to the embodiment of the present invention includes a first electrode 150 formed separately for each pixel region P, a second electrode 150 formed on the entire display region for displaying an image, A quantum rod layer 155 interposed between the first and second electrodes 150 and 160 and a second substrate 170 facing the quantum rod layer 155. The quantum rod layer 155 is disposed between the first and second electrodes 150 and 160, A backlight unit 180, and a polarizing reproduction film 197 for improving the light efficiency.

In order to improve the light efficiency of the quantum rod layer 155, the polarized light reproduction film 197 selectively reflects only the light polarized in a specific direction among the light emitted from the backlight unit 180 into the quantum rod layer 155 It is characterized by the continuous recycling of light inside it.

In the quantum rod light emitting display 101 according to the embodiment of the present invention having such a configuration, the quantum rod layer 155 absorbs light emitted from the backlight unit 180, and electrons and holes are recombined internally, Fluorescence.

At this time, a voltage is applied to the first and second electrodes 150 and 160 located below and above the quantum rod layer 155 to generate electric fields with different intensities, The recombination rate of electrons and holes is controlled within the rod to display a gray level. The quantum rod layer 155 can generate red, green and blue by varying the quantum rod size for each pixel region P A full-color image can be displayed.

First, a structure of the first substrate 110 including the first and second electrodes 150 and 160 and the quantum rod layer 155 will be described. A transparent insulating substrate, for example, a transparent glass substrate or a flexible plastic substrate For example, aluminum (Al), an aluminum alloy (AlNd), copper (Cu), a copper alloy, molybdenum (Mo), and molybdenum alloy (MoTi) on the first substrate 110, Gate wirings (not shown) extending in a first direction are formed of one or more materials to be selected.

The switching region TrA in each pixel region P is connected to the gate wiring (not shown) and a gate electrode 108 is formed.

An inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is formed on the entire surface of the first substrate 110 over the gate wiring (not shown) and the gate electrode 108, Respectively.

In the switching region TrA above the gate insulating layer 115, an active layer 120a of pure amorphous silicon and an ohmic contact layer of impurity amorphous silicon And source and drain electrodes 133 and 136 are formed on the semiconductor layer 120. The source and drain electrodes 133 and 136 are spaced apart from each other and are in contact with the ohmic contact layer. At this time, the active layer 120a is exposed between the source and drain electrodes 133 and 136 which are spaced apart from each other.

The gate electrode 108, the gate insulating film 115, the semiconductor layer 120, and the source and drain electrodes 133 and 136, which are sequentially stacked in the switching region TrA, constitute a thin film transistor Tr.

A data line 130 crossing the gate line (not shown) and defining the pixel region P extends in the second direction and is connected to the source electrode (not shown) of the thin film transistor Tr 133, respectively.

At this time, a dummy pattern 121 composed of the first and second semiconductor patterns 121a and 121b is formed under the data line 130 using the same material as the active layer 120a and the ohmic contact layer 120b However, this is an example of manufacturing process characteristics, and the dummy pattern 121 may be omitted.

In the figure, the thin film transistor Tr includes an active layer 120a made of amorphous silicon and a semiconductor layer 120 of the ohmic contact layer 120b, and a bottom electrode (gate electrode) Type semiconductor layer, a semiconductor layer of polysilicon, a gate insulating film, a gate electrode, an interlayer insulating film, and a source which is in contact with the semiconductor layer of the polysilicon and which are spaced apart from each other And a top gate type having a structure in which drain electrodes are sequentially layered.

When such a top gate type thin film transistor is provided, a gate wiring (not shown) is provided above the gate insulating film on which the gate electrode is formed, and the data wiring is provided on the interlayer insulating film.

Referring to FIG. 4, a protective layer 140 having a flat surface is formed on the data line 130 and the source and drain electrodes 133 and 136. A drain contact hole 143 is formed in the passivation layer 140 to expose the drain electrode 136 of each thin film transistor Tr for each pixel region P.

A first electrode (not shown) is formed on the passivation layer 140 and is in contact with the drain electrode 136 of the thin film transistor Tr through the drain contact hole 143 in each pixel region P 150 are formed.

A gate line (not shown) and a gate line (not shown) are formed on the first electrode 150 and the protective layer 140 exposed between the first electrode 150 and the data line 130 A buffer pattern 152 is formed to overlap the edge of the first electrode 150.

A quantum rod layer 155 formed of a plurality of quantum rods 156 is formed on the first electrode 150 in each pixel region P surrounded by the buffer pattern 152. At this time, the quantum rod layer 155 is provided with quantum rods 156a, 156b, 156c having cores (157 of FIG. 2) of different sizes for each pixel region P emitting red, green and blue Or a quantum rod (156 in FIG. 2) having a core of the same size (157 in FIG. 2) may be provided.

The plurality of quantum rods 156 provided on the quantum rod layer 155, which is one of the most characteristic structures according to the embodiment of the present invention, has a long axis on the entire surface of the display region of the first substrate 110 And is arranged in one direction.

The quantum rod 156 may be aligned in one direction within the quantum rod layer 155 by, for example, a voltage application method, an alignment method using an orientation film, a self-aligned monomer An aligning method using a reactive mesogen material, and an aligning method using a reactive mesogen material. At this time, the alignment of the quantum rod 156 in one direction is not limited to the above-described alignment method, and various other alignment methods may be used.

On the other hand, the degree to which the long axis of the quantum rod 156 is well oriented in one direction, that is, the degree of orderliness, can be found by measuring the polarization ratio.

The degree of polarization of the quantum rod layer 155 can be determined by measuring the amount of light passing through the photomultiplier plate (not shown) after irradiating the horizontal or vertical polarized light toward the quantum rod layer 155 in any specific direction have.

That is, assuming that the intensity of the light emitted from the light source (not shown) is I, the light having only the horizontal component parallel to the imaginary reference line extending parallel to the quantum rod layer 155 in one direction is I _h , The polarization ratio PR is defined as I _v when the light having only the vertical component perpendicular to the reference line is defined as I _v and the direction of the long axis of the quantum rod is not ordinarily given, ,

PR = (I _h - I _v ) / (I _h + I _v )

.

In this case, when the quantum rod layer 155 is arranged in one direction, that is, in the horizontal direction or the vertical direction by the progress of the alignment process, the polarization ratios PR _h and PR _v in the horizontal and vertical directions are Is defined.

PR _h = I _h / (I _h + I _v ),

PR _v = I _v / (I _h + I _v )

The reason why the plurality of quantum rods 156 are aligned in one direction within the quantum rod layer 155 is that the polarization ratio PR _{h in} the horizontal direction or the polarization ratio PR _v in the vertical direction is larger than 0.5 and smaller than 1 That is, 0.5 <PR _h or PR _v <1.

On the other hand, when the quantum rods 156a, 156b, and 156c having cores (157 of FIG. 2) having different sizes are provided for each pixel region P representing red, green, and blue, 156c are characterized in that the wavelength of the fluorescent light is changed according to the size of the core 157 (FIG. 2). As the size of the core 157 (FIG. 2) decreases, The fluorescence of the long wavelength is generated.

Accordingly, in the embodiment of the present invention, the quantum rod layer 155a made up of the quantum rod 156a having the largest-sized core (157 in FIG. 2) corresponding to the pixel region P to be red is formed (157 in Fig. 2) of the quantum rod 156a provided in the pixel region P that represents the red color sequentially with respect to the pixel region P which should exhibit green and blue colors, The quantum rod layers 155b and 155c having the quantum rods 156b and 156c each having the quantum rods 157a and 157b (157 in Fig. 2) are formed.

In the embodiment of FIG. 4, the quantum rod layer 155 is formed separately for each of the pixel regions P. However, as a modification, FIGS. 5A and 5B The quantum rod layer 155 may be formed on the entire surface of the display region where a plurality of pixel regions P are provided, as shown in a cross-sectional view of the quantum rod light emitting display device according to the first and second modified examples) In this case, the buffer pattern 152 provided at the boundary of each pixel region P may be omitted.

Referring to FIG. 4, a second substrate 170 is provided corresponding to the first substrate 110 having such a configuration.

At this time, the second substrate 170 may be a transparent insulating substrate such as the first substrate 110, or may be made of a glass material or a plastic material having a flexible property, or may be a sheet made of a polymer material, Film.

A black matrix 173 is formed on the inner surface of the second substrate 170 made of such a material corresponding to the switching region TrA where the boundary of the pixel region P and the thin film transistor Tr are formed .

The black matrix 173 must be provided to prevent light leakage in the case of the first and second modifications (see FIGS. 5A and 5B) in which the quantum rod layer 155 is formed on the entire display region. (Refer to FIG. 4) and the third modification (refer to FIG. 5C) in which the layer 155 is separately formed for each pixel region P, as shown in FIG.

4, only the black matrix 173 is provided on the inner surface of the second substrate 170 in the embodiment of the present invention. However, when the quantum rod layer 155 is provided in each pixel region P ) (Fig. 2) 156 having a core (157 in Fig. 2) having the same size as the quantum rod light emitting display of Fig. 5C (the quantum rod light emitting display according to the third modification of the embodiment of the present invention Rust, red, green and blue in the form of sequential repeating in the neighboring three pixel regions P corresponding to the region surrounded by the black matrix 173 for full color implementation, The color filter layer 155 to which the blue color filter patterns 175a, 175b, and 175c correspond may be provided.

Although not shown in the drawing, the black matrix 173 and the overcoat layer (not shown) may be provided on the entire surface of the second substrate 170 above the color filter layer.

4, the quantum rod layer 155 provided on the first substrate 110 may have a different size for each pixel region P that should exhibit red, green, In the embodiment where the quantum rods 156a, 156b, and 156c having the quantum rods 156a, 156b, and 156c having the red, green, and blue colors are provided, (Not shown) in which red, green, and blue color filter patterns (not shown) are disposed on the substrate P, respectively.

On the other hand, a backlight unit 180 for supplying light to the quantum rod layer 155 is provided on the lower surface of the quantum rod panel 102 having such a configuration, more precisely on the outer surface of the first substrate 110.

The backlight unit 180 includes a light source 182, a reflection plate 185, and a light guide plate 187 that is mounted on the reflection plate 185.

In this case, the light source 182 generates light of a short wavelength range, for example, blue visible light or UV light, which is smaller than 450 nm in the characteristics of the present invention. The CCFL (cold cathode fluorescent lamp) The light source 182 may be a light emitting diode (LED) or a light emitting diode (LED).

The light source 182 is disposed on one side of the light guide plate 187 so as to face the light incident portion of the light guide plate 187.

The light guide plate 187 spreads the light incident from the light source 182 evenly into the light guide plate 187 while advancing the light through the light guide 182 several times, .

At this time, the light guide plate 187 may include a pattern (not shown) having a specific shape on the back surface to supply a uniform surface light source to the quantum rod panel 102.

In order to guide the light incident into the light guide plate 187, a pattern (not shown) of a specific shape may be formed of an elliptical pattern, a polygon pattern, a hologram pattern, And such a pattern is formed on the lower surface of the light guide plate 187 by a printing method or an injection method.

The reflection plate 185 is disposed on the back surface of the light guide plate 187 and reflects the light that has passed through the back surface of the light guide plate 187 toward the quantum rod panel 102 to improve the brightness of light.

The backlight unit 180 having such a configuration is an edge type in which the light source 182 is provided on the side surface of the light guide plate 187 and the surface light source is incident on the quantum rod panel 102 by the light guide plate 187 However, the backlight unit 180 may be a direct-type type.

In the case of the direct type backlight unit (not shown), fluorescent lamps are arranged as a plurality of light sources at a predetermined interval on the upper side of the reflection plate, or a driving substrate for LEDs in which a plurality of light emitting diodes are arranged is provided And a diffusion plate is provided on the upper side thereof in place of the light guide plate.

Meanwhile, as one of the most characteristic structures of the quantum rod light emitting display device 101 according to the embodiment of the present invention, between the backlight unit 180 and the quantum rod panel 102 having the above- Polarized light emitted from the polarized light source 180 is recycled and has a polarized state, and only the polarized light in a specific direction is incident on the quantum rod panel 102 side 197) are provided.

The polarization reproduction film 197 is also referred to as a DBEF (Dual Brightness Enhancement Film) film. The polarized light reproduction film 197 is continuously incident on the quantum rod layer 155 in one direction, Thereby ultimately improving the amount of light that is fluoresced by the quantum rod layer 155.

Since the polarization reproducing film 197 serves to convert the non-polarized light emitted from the backlight unit 180 into polarized light, it is essential that the unpolarized light directly enters the quantum rod layer 155 It is another feature that prevents light leakage by preventing it.

The quantum rod layer 155 has a greater efficiency in absorbing light than when the longitudinal axes of the quantum rods 156 are arranged in one direction and the quantum rods 156 are disorderly arranged without directionality, The quantum rod layer 155 in which the long axes of the quantum rods 156 are arranged in one direction has a property of absorbing polarized light having a polarization axis perpendicular to the direction in which the long axes of the quantum rods 156 are arranged rather than non- .

Therefore, in the embodiment of the present invention, a polarized reproduction film 197 is provided between the backlight unit 180 and the quantum rod panel 102 to improve the fluorescence property of the quantum rod layer 155.

At this time, the polarizing reproduction film 197 recycles the light emitted from the backlight unit 180 generating the non-polarized light into the inside of the backlight unit 180 without lowering the luminance, and at the same time, Since the incident light is incident on the quantum rod panel 102 side, the luminance reproduction is not caused by the polarized reproduction film 197.

Therefore, since the light emitted through the polarized reproduction film 197 becomes polarized light in one direction, the absorption rate in the quantum rod layer 155 is improved, and the fluorescent property is improved by the improvement of the absorption rate, .

Thereafter, the quantum rod light emitting display device 101 including the polarized reproduction film 197 according to the embodiment of the present invention and the comparative example 197 as the quantum rod light emitting device without the polarization reproduction film 197 are turned off and on State light display state of the light in the state shown in Fig.

FIG. 6 is a view showing only a backlight unit and a quantum rod layer in a quantum rod light emitting display device without a polarized reproduction film as a comparative example, and also shows progress of light according to the off and on states of an electric field.

As shown in the figure, in the case of an electric field OFF state in which no electric field is applied to the quantum rod layer 255, unpolarized light is generated from the backlight unit 280, and this unpolarized light is transmitted to the quantum rod layer 255 .

At this time, most of the non-polarized light incident on the quantum rod layer 255 is absorbed by the quantum rod layer 255, and the quantum rod layer 255 is illuminated by the action of the quantum rod layer 255, And then comes out to display white. At this time, part of the unpolarized light emitted from the backlight unit 280 passes through the quantum rod layer 255 without being absorbed by the quantum rod layer 255.

In this case, the normal light absorbed and fluoresced by the quantum rod layer 255 is mixed with the abnormal light emitted from the backlight unit 280 through the quantum rod layer 255, The light leakage causing the display quality deterioration is generated.

When the electric field is turned on in the quantum rod layer 255, normally, light should not be emitted from the quantum rod layer 255. However, since light emitted from the backlight unit 280 is in a non-polarized state, Some of the unpolarized light is not absorbed by the quantum rod layer 255 having the quantum rod 256 arranged in one direction and passes through the quantum rod layer 255 to generate light leakage, can not do.

Therefore, in the quantum rod light emitting display device according to the comparative example in which such a polarized reproduction film is not provided, the light leakage that the non-polarized light coming from the backlight unit 280 is directly emitted from the display region is generated, .

However, the quantum rod light emitting display device according to the embodiment of the present invention has a polarizing reproduction film, so that the light leakage generated in the quantum rod light emitting device according to the comparative example is suppressed to improve the display quality.

7 is a view schematically showing only a backlight unit, a polarized light reproduction film and a quantum rod layer in a quantum rod light emitting display according to an embodiment of the present invention, and shows progress of light according to an off and on state of an electric field .

The quantum rod light emitting display according to an embodiment of the present invention generates non-polarized light from the backlight unit 180 when an electric field is not applied to the quantum rod layer 155, And is polarized in the process of total reflection inside the polarized reproduction film 197.

At this time, when the polarized light is incident on the quantum rod layer 155, the polarization reproduction film 197 is polarized in a specific direction.

The light having passed through the polarized-light reproduction film 197 is polarized in one direction. More specifically, the light emitted from the polarized-light reproduction film 197 passes through the polarization axis The absorption coefficient of the quantum rod layer 155 is improved.

Accordingly, the quantum rod layer 155 displays white (or a full-color image) finally by being absorbed by fluorescence due to the internal action of the absorbed light.

On the other hand, when an electric field is applied to the quantum rod layer 155, the quantum rod layer 155 absorbs light by the action of the quantum rod layer 155 and does not generate fluorescence. The light polarized in one direction incident on the quantum rod layer 155 is absorbed by the quantum rod layer 155 to finally display a completely black state.

In this case, the non-polarized light generated in the backlight unit 180 is polarized in one direction while passing through the polarized light reproduction film 197, and the light polarized in one direction is mostly emitted from the quantum Absorbed in the rod layer 155, the light leakage phenomenon generated by the undesired non-polarized light transmitted through the quantum rod layer 155 is hardly generated in both the ON state of the electric field and the OFF state of the electric field.

4, since the quantum rod display device 101 according to the embodiment of the present invention having such a configuration and the first, second, and third modified examples does not require a polarizer, the polarizing plate is provided, In addition, there is an effect that a high luminance characteristic and a low power consumption characteristic are obtained compared with a liquid crystal display device in which power consumption is increased by providing a brighter light source to improve the lowered luminance characteristic.

Further, the quantum rod 156, which is different in the size of the core for displaying red, green, and blue, is provided, and thus materials having different physical properties are used to display red, green, and blue colors as in an organic electroluminescent device. There is no significant difference between the substances, and the duration of the fluorescent property is relatively large compared with the substance which emits light itself, which has an effect of longevity.

By providing the polarizing reproduction film 197, the characteristic of the quantum rod 156 that absorbs the light polarized in one direction can be used more advantageously, so that the amount of fluorescent light is increased to further improve the luminance characteristic.

In addition, by providing the polarizing reproduction film 197, the light leakage is suppressed compared to the quantum rod light emitting display device not including it, and the display quality is improved.

The present invention is not limited to the above-described embodiments, and various changes and modifications may be made without departing from the spirit of the present invention.

101: Quantum rod light emission display device 102: Quantum rod panel
110: first substrate 108: gate electrode
115: gate insulating film 120: semiconductor layer
120a: active layer 120b: ohmic contact layer
121: dummy patterns 121a and 121b: first and second dummy patterns
130: data line 133: source electrode
136: drain electrode 140: protective layer
143: drain contact hole 150: first electrode
152: buffer pattern 155: quantum road layer
155a, 155b, and 155c: quantum rod layers that fluoresce red, green, and blue, respectively
156: Quantum Road
156a, 156b, 156c: Quantum rod (each having a different core size)
160: second electrode 170: second substrate
173: Black matrix 180: Backlight unit
182: light source 185: reflector
187: light guide plate 197: polarized reproduction film
P: pixel region Tr: thin film transistor
TrA: switching area

Claims (24)

A quantum rod panel including first and second substrates facing each other, and a quantum rod layer interposed between the first and second substrates and having a plurality of quantum rods arranged in one direction;
A backlight unit provided under the quantum rod panel;
And a backlight unit that is provided between the quantum rod panel and the backlight unit, receives the non-polarized light emitted from the backlight unit, recycles the polarized light from the backlight unit, imparts polarization to the quantum rod panel, The polarizing film
/ RTI &gt;
In the first substrate,
A thin film transistor arranged in each pixel region, a first electrode connected to the thin film transistor, and a second electrode arranged above the first electrode,
Wherein the quantum rod layer includes a core disposed between the first electrode and the second electrode and including electrons and holes,
And displays a gray level through light polarized in the specific direction provided from the polarized-light reproduction film according to a voltage applied to the first electrode and the second electrode.
The method according to claim 1,
Wherein the quantum rod light emitting device is a direction perpendicular to a polarization axis of light polarized in one direction in which the plurality of quantum rods are arranged and in a specific direction passing through the polarization reproducing film.
The method according to claim 1,
The first substrate is provided with first, second and third pixel regions indicating red, green, and blue,
Wherein the quantum rod layer comprises a quantum rod having cores of different sizes for the first, second and third pixel regions.
The method of claim 3,
And the second substrate is provided with red, green, and blue color filter patterns corresponding to the first, second, and third pixel regions, respectively.
The method according to claim 1,
The first substrate is provided with first, second and third pixel regions which exhibit red, green and blue, and the quantum rod layer has a quantum rod having cores of the same size in the first, second and third pixel regions In addition,
And the second substrate is provided with red, green, and blue color filter patterns corresponding to the first, second, and third pixel regions, respectively.
The method of any one of claims 1, 3, and 5,
Wherein the quantum rod layer is formed separately on the first substrate or on the entire display region for displaying an image.
The method according to claim 1,
Wherein the first substrate includes gate wirings and data wirings intersecting with each other to define first, second and third pixel regions,
Wherein the thin film transistor is connected to the gate wiring and the data wiring,
And the first electrode is connected to the drain electrode of the thin film transistor.
The method according to claim 1,
When the plurality of quantum rods are arranged in one direction,
The intensity of light emitted from the light source is I, the light with only the horizontal component is I _h , the light with only the vertical component is I _v , the polarization ratio PR _h in the horizontal direction and the polarization ratio PR _v in the vertical direction are PR _h = _{I h / (I h + I} v), PR v = I v / (I h + I v) when defined as, polarizing ratio PR _h or polarization ratio PR _v in a direction perpendicular to the horizontal direction is greater than 0.5 1 (PR _v ) <1, that is, 0.5 <PR _h (or PR _v ) <1.
The method according to claim 1,
The quantum rod may be made of only the core,
Or a shell surrounding the core and the core,
Wherein the shell has a shape having a minor axis and a major axis, and a ratio of the minor axis to the major axis is 1: 1.1 to 1:30.
10. The method of claim 9,
The quantum rod may have one of a spherical shape, an elliptical shape, a polyhedral shape, and a rod shape,
Wherein the cut surface cut in the minor axis direction of the quantum rod has a shape of a circle, an ellipse, or a polygonal shape.
11. The method of claim 10,
Wherein the shell comprises a single layer or multilayer structure.
10. The method of claim 9,
Wherein the shell is made of an alloy, an oxide-based material, or an impurity-doped material.
10. The method of claim 9,
Wherein the core is made of a semiconductor, an alloy or a mixed material of Group II-VI, Group III-V, Group III-VI, Group IV-VI, and Group IV on the periodic table.
14. The method of claim 13,
The core of the quantum rod may be made of any one of CdSe, CdS, CdTe, ZnO, ZnSe, ZnSe, HgSe, HgTe, CdZnSe, CdSeTe, ZnCdSe, &Lt; / RTI &gt;
In the case of the III-V group, the second electrode is made of any one material selected from among InP, InN, GaN, InSb, InAsP, InGaAs, GaAs, GaP, GaSb, AlP, AlN, AlAs and AlSb,
Wherein the quantum rod light emitting display device is formed of one of PbSe, PbTe, PbS, PbSnTe, and Ti2SnTe5 or a material in which two or more materials are mixed.
The method according to claim 1,
The backlight unit includes:
An edge type backlight unit including a reflection plate, a light guide plate positioned above the reflection plate, and a light source located on a side of the light guide plate,
Or a direct-type backlight unit comprising a reflection plate, a plurality of light sources located above the reflection plate, and a diffusion plate located above the plurality of light sources.
The method according to claim 1,
Wherein the backlight unit generates blue or ultraviolet light having a short wavelength of 430 nm or less. The method according to claim 1,
The electrons and the holes may be coupled to or separated from each other depending on the presence or absence of an electric field formed by the first and second electrodes,
Wherein quantized light amount and / or amount of emitted light is controlled in the course of transmitting the light polarized in the specific direction provided from the polarized light reproducing film through the quantum rod layer.
18. The method of claim 17,
Wherein a coupling ratio of the electron and the hole is varied according to the intensity of the electric field.
The method according to claim 1,
When an electric field is formed between the first and second electrodes,
The quantum rod film is absorbed by the quantum rod layer so that all of the light polarized in the specific direction transmitted from the polarized-light reproduction film is absorbed by the quantum rod layer,
When an electric field is not formed between the first and second electrodes,
Wherein the quantum rod light is polarized in the specific direction and transmitted through the polarized light reproduction film is absorbed by the quantum rod layer and then fluoresced, and the quantum rod panel displays white.
The method of claim 3,
Wherein the quantum rod layer positioned corresponding to the first pixel region has a first size of the core,
Wherein the quantum rod layer positioned corresponding to the second pixel region has a second size smaller than the first size,
And the quantum rod layer located corresponding to the third pixel region has a third size where the core is smaller than the second size.
The method according to claim 6,
Wherein a buffer pattern is provided at the boundaries of the first, second, and third pixel regions when the quantum rod layer is formed separately for the first, second, and third pixel regions. 8. The method of claim 7,
The thin film transistor includes a gate electrode positioned on the first substrate, a gate insulating film located on the first substrate including the gate electrode,
A semiconductor layer including an active layer and an ohmic contact layer sequentially disposed on the gate insulating film in correspondence with the gate electrode;
And a source electrode spaced apart from the semiconductor layer and contacting the ohmic contact layer, respectively, and the drain electrode.
23. The quantum rod light emitting display of claim 22, wherein the gate electrode is connected to the gate wiring, and the source electrode is connected to the data wiring.
23. The method of claim 22,
And a dummy pattern composed of the first semiconductor pattern and the second semiconductor pattern is disposed under the data line with the same material forming the active layer and the ohmic contact layer.

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