KR20100022425A - Organic light emitting diode display - Google Patents

Abstract

PURPOSE: An organic light emitting display device is provided to suppress reflection of external light by forming an optical unit on an organic light emitting device. CONSTITUTION: An organic light emitting device includes a pixel electrode, an organic light emitting layer, and a common electrode. A DBEF(Dual Brightness Enhancement Film)(585) is formed on the common electrode of the organic light emitting device. A first phase delay plate(584) is formed on the DBEF. A corner cube film(583) is formed on the first phase delay plate and includes a corner cube layer and a cover layer. A second phase delay plate(582) is formed on the corner cube film. A polarizer(581) is formed on the second phase delay plate.

Description

Organic Light Emitting Display {ORGANIC LIGHT EMITTING DIODE DISPLAY}

The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device having improved display characteristics.

The organic light emitting diode display includes a plurality of organic light emitting diodes having a hole injection electrode, an organic emission layer, and an electron injection electrode. In the organic light emitting layer, light is emitted by energy generated when an exciton generated by combining electrons and holes falls from an excited state to a ground state, and the organic light emitting diode display forms an image by using the energy.

Therefore, the organic light emitting diode display has a self-luminous property and, unlike the liquid crystal display, does not require a separate light source, thereby reducing thickness and weight. In addition, the organic light emitting diode display has attracted attention as a next-generation display device for portable electronic devices because it exhibits high quality characteristics such as low power consumption, high luminance, and high response speed.

In general, at least one of the hole injection electrode and the electron injection electrode of the organic light emitting diode display and other metal wires may reflect light flowing from the outside. Therefore, when the organic light emitting diode display is used in a bright place, there is a problem in that black expression and contrast are poor due to external light reflection.

In order to solve such a problem, there exists a structure which suppresses external light reflection by arrange | positioning a polarizing plate and a phase retardation plate. However, when the polarizing plate and the phase retardation plate are disposed to suppress external light reflection, there is a problem in that light generated in the organic light emitting layer is also substantially lost when emitted to the outside through the polarizing plate and the phase retardation plate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an organic light emitting display device which minimizes the loss of light emitted from the organic light emitting layer to the outside while suppressing external light reflection and improving visibility.

An organic light emitting diode display according to an exemplary embodiment of the present invention includes an organic light emitting device including a pixel electrode, an organic light emitting layer formed on the pixel electrode, and a common electrode formed on the organic light emitting layer, and a reflection formed on the common electrode of the organic light emitting device. Type polarizing film, a first phase retardation plate formed on the reflective polarizing film, a corner cube film formed on the first phase retardation plate, a second phase retardation plate formed on the corner cube film, and the second phase retardation And a polarizing plate formed on the plate.

The corner cube film may include a corner cube layer in which a plurality of corner cubes are formed, and a cover layer covering one surface of the corner cube layer in which the corner cubes are formed.

The corner cube of the corner cube layer may protrude toward the first phase retardation plate.

The corner cube layer may have a larger refractive index than the cover layer.

The cover layer may have an adhesive force.

The cover layer may be disposed between the corner cube layer and the first phase retardation plate to bond the corner cube layer and the first phase retardation plate to each other.

Two or more of the reflective polarizing film, the first phase retardation plate, the corner cube film, the second phase retardation plate, and the polarization plate may be integrally formed.

In the organic light emitting diode display, the polarizing plate and the reflective polarizing film may have the same polarization axis.

The first phase retardation plate and the second phase retardation plate may have the same optical axis and may be quarter wave plates.

An angle between an optical axis of the first phase retardation plate and the second phase retardation plate and a polarization axis of the polarizing plate and the reflective polarizing film may be 45 degrees.

According to the present invention, the organic light emitting diode display can minimize reflection of external light and improve visibility while minimizing the loss of light emitted from the organic light emitting layer. That is, display characteristics of the organic light emitting diode display may be improved.

In addition, the organic light emitting diode display may reduce power consumption and improve lifespan.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In addition, the size and thickness of each configuration shown in the drawings are arbitrarily shown for convenience of description, the present invention is not necessarily limited to the illustrated.

In addition, in the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. When a portion of a layer, film, region, plate, or the like is said to be "on" or "on" another portion, this includes not only when the other portion is "right over" but also when there is another portion in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

In order to clearly describe the present invention, parts irrelevant to the description are omitted, and like reference numerals designate like elements throughout the specification.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

As illustrated in FIG. 1, the organic light emitting diode display 100 includes a driving circuit unit DC, an organic light emitting element L1, and an optical member 58.

The optical member 58 suppresses reflection of external light to improve visibility of the organic light emitting diode display 100, and minimizes loss of light emitted from the organic light emitting element L1 to the outside. The optical member 58 includes a reflective brightness film (DBEF) 585, a first phase retardation plate 584, a corner cube film 583, and a second phase retardation plate 582. ), And a polarizing plate 581.

The reflective polarizing film 585, the first phase retardation plate 584, the corner cube film 583, the second phase retardation plate 582, and the polarizing plate 581 are sequentially disposed on the organic light emitting element L1. .

The driving circuit unit DC and the organic light emitting element L1 are generally formed on the first substrate 51. That is, the first substrate 51 includes a substrate member 511, a driving circuit portion DC formed on the substrate member 511, and an organic light emitting element L1 formed on the driving circuit portion DC.

The driving circuit part DC generally has an arrangement structure as shown in FIG. 2. That is, as shown in FIG. 2, the driving circuit unit DC includes two or more thin film transistors T1 and T2 and one or more storage capacitors C1. The thin film transistor basically includes a switching transistor T1 and a driving transistor T2.

The switching transistor T1 is connected to the scan line SL1 and the data line DL1, and converts the data voltage input from the data line DL1 into the driving transistor T2 according to the switching voltage input to the scan line SL1. send. The storage capacitor C1 is connected to the switching transistor T1 and the power supply line VDD and stores a voltage corresponding to a difference between the voltage received from the switching transistor T1 and the voltage supplied to the power supply line VDD.

The driving transistor T2 is connected to the power line VDD and the storage capacitor C1 to output an output current I _OELD proportional to the square of the difference between the voltage stored in the storage capacitor C1 and the threshold voltage. It supplies to L1, and the organic light emitting element L1 emits light by the output current I _OLED .

Referring again to FIG. 1, the driving transistor T2 includes a source electrode 533, a drain electrode 532, and a gate electrode 531.

The organic light emitting element L1 includes a pixel electrode 544, an organic emission layer 545 formed on the pixel electrode 544, and a common electrode 546 formed on the organic emission layer 545. In general, the pixel electrode 544 becomes an anode electrode, and the common electrode 546 becomes a cathode electrode. The pixel electrode 544 of the organic light emitting element L1 is connected to the drain electrode 532 of the driving transistor T2.

In addition, one or more electrodes of the pixel electrode 544 and the common electrode 546 may be formed to be transflective or reflective to reflect light.

The configuration of the driving circuit unit DC and the organic light emitting element L1 is not limited to the above-described example, and may be variously modified to a known configuration that can be easily implemented by those skilled in the art.

The polarizing plate 581 has a polarization axis and linearly polarizes light. Specifically, the polarizing plate 581 passes light that coincides with the polarization axis, and absorbs light that does not coincide with the polarization axis. That is, when light passes through the polarizing plate 581, the light is linearly polarized in the direction of the polarization axis of the polarizing plate 581.

The first phase retardation plate 584 and the second phase retardation plate 582 change the phase of light passing through. Specifically, in one embodiment according to the present invention, a quarter wave plate is used for the first phase retardation plate 584 and the second phase retardation plate 582, and converts linearly polarized light into circularly polarized light.

The reflective polarizing film (DBEF) 585 also passes light coinciding with the polarization axis, but reflects light that does not coincide with the polarization axis. That is, the polarizing plate 581 is different from the reflective polarizing film 585 in that it absorbs light that does not coincide with the polarization axis. In one embodiment according to the present invention, the reflective polarizing film 585 may have the same polarization axis as that of the polarizing plate 581.

In addition, linearly polarized light passing through the polarizing plate 581 becomes right circularly polarized light through the second phase retardation plate 582. The first phase retardation plate 584 and the second phase retardation plate 582 should be arranged to be linearly polarized in the same manner as the linear polarization.

In addition, the reflective polarizing film 585, the first phase retardation plate 584, the second phase retardation plate 582, and the polarizing plate 581 are arranged to satisfy the following conditions. Light passes through the polarizing plate 581 to become linearly polarized light, and the linearly polarized light becomes right circularly polarized light through the second phase retardation plate 582. The right circularly polarized light becomes linearly polarized light while passing through the first camouflage retardation plate 584, and the linearly polarized light should be able to pass through the reflective polarizing film 585 as it is. In addition, the light must be able to pass through without being lost in the reverse order.

The corner cube film 583 includes a corner cube layer 5831 in which the corner cubes 5835 are formed, and a cover layer 5832 covering one surface on which the corner cubes 5835 are formed in the corner cube layer 5831. At this time, the cover layer 5832 is formed in close contact with the corner cube (5835).

In the corner cube layer 5831, the corner cube 5835 protrudes toward the first phase retardation plate 584. That is, the cover layer 5832 covering the corner cube layer 5831 is disposed between the corner cube layer 5831 and the first phase retardation plate 584. The corner cube layer 5831 has a larger refractive index than the cover layer 5832. That is, the cover layer 5832 is made of a material having a refractive index smaller than that of the corner cube layer 5831.

The corner cube 5835 is formed in a triangular pyramid shape as shown in FIG. 3. That is, the corner cube 5835 has a shape obtained by cutting the corners of the cube. The corner cubes 5835 are formed in a fine pattern on one surface of the corner cube layer 5831.

The corner cube layer 5831 formed as described above reflects light in a direction parallel to the incident direction. That is, when light is incident on the corner cube layer 5831, the light is reflected toward the incident direction. At this time, a material having a lower refractive index than the corner cube layer 5831 should be in contact with the surface opposite to the surface where the light is incident on the corner cube layer 5831.

On the other hand, in the corner cube film 583, the cover layer 5832 having a lower refractive index than the corner cube layer 5831 is in contact with one surface of the corner cube layer 5831. In such a structure, the light directed from the cover layer 5832 toward the corner cube layer 5831 passes through the corner cube film 583 as it is, and the light directed from the corner cube layer 5831 to the cover layer 5832 is It is reflected toward the direction incident on the corner cube layer 5831.

Specifically, when external light is incident on the corner cube film 583 through the polarizing plate 581 and the second phase retardation plate 582, it is reflected in parallel to the incident direction toward the incident direction. At this time, the light reflected from the corner cube film 583 is at least partially lost while again passing through the second phase delay plate 582 and the polarizing plate 581. In addition, since the light passing through the polarizing plate 581 to the outside without being lost is reflected in the incident direction, the reflected external light to the user looking at the organic light emitting display device 100 is suppressed. That is, the visibility of the organic light emitting diode display 100 is improved.

In addition, the cover layer 5832 of the corner cube film 583 may have an adhesive force, and the cover layer 5832 may adhere the corner cube layer 5831 and the first phase retardation plate 584 to each other. That is, the corner cube film 583 and the first phase retardation plate 584 may be integrally formed with each other. In addition, two or more or all of the reflective polarizing film 585, the first phase retardation plate 584, the corner cube film 583, the second phase retardation plate 582, and the polarizing plate 581 may be integrally formed. Can be.

The second substrate 52 covers the first substrate 51 on which the organic light emitting element L1 and the driving circuit unit DC are formed. In addition, the second substrate 52 also covers the optical member 58 formed on the organic light emitting element L1. However, the present invention is not necessarily limited thereto. Thus, the optical member 58 may be formed on the second substrate 52. That is, the position of the optical member 58 may be freely disposed as long as it is on the organic light emitting element L1.

By such a configuration, the organic light emitting diode display 100 may effectively suppress reflection of external light to improve visibility and minimize loss of light emitted from the organic light emitting layer 545 to the outside. That is, display characteristics of the organic light emitting diode display 100 may be improved.

In addition, the organic light emitting diode display 100 may efficiently emit light generated by the organic light emitting layer 545 to the outside, thereby reducing power consumption and improving lifespan.

Hereinafter, referring to FIG. 4, reflection of external light in the organic light emitting diode display 100 may be suppressed, and a loss of light emitted from the organic light emitting layer 545 (shown in FIG. 1) to the outside may be minimized. Look in detail.

First, the path of light emitted from the organic light emitting layer 545 (shown in FIG. 1) to the outside is as follows.

Light emitted from the organic light emitting layer 545 (shown in FIG. 1) is linearly polarized while passing through the reflective polarizing film 585, and is linearly polarized while passing through the first phase retardation plate 584. In this case, the light that does not pass through the reflective polarizing film 585 circulates while being continuously reflected between the reflective polarizing film 585 and the common electrode 546. That is, some of the light reflected from the common electrode 546 and directed back to the reflective polarizing film 585 is linearly polarized, and the remaining light is repeatedly repeated. In addition, although FIG. 4 illustrates that light is reflected between the reflective polarizing film 585 and the common electrode 546, the present invention is not limited thereto. Thus, light may be reflected between the reflective polarizing film 585 and the pixel electrode 544 (shown in FIG. 1).

The linearly polarized light passing through the reflective polarizing film 585 changes to circularly polarized light while passing through the first phase retardation plate 584. The circularly polarized light passes through the corner cube film 583 as it is. The corner cube film 583 includes a low refractive index cover layer 5832 facing the first phase retardation plate 584, and a high refractive index corner cube layer 5831 bonded directly over the cover layer 5832. Therefore, most of the light from the first phase retardation plate 584 to the corner cube film 583 passes through without being reflected.

The circularly polarized light passing through the corner cube film 583 becomes linearly linear light while passing through the second phase retardation plate 582. This linear flat light passes through the polarizing plate 581 to the outside through an optical axis arrangement between the reflective polarizing film 585, the first phase retardation plate 584, the second phase retardation plate 582, and the polarizing plate 581. Can head. Specifically, the polarizing plate 581 and the reflective polarizing film 585 have the same polarization axis, and the first phase retardation plate 584 and the second phase retardation plate 582 have the same optical axis. And the pier between the optical axis of the first phase retardation plate 584 and the second phase retardation plate 582 and the polarization axis of the polarizing plate 581 and the reflective polarizing film 585 is arranged to be 45 degrees.

Therefore, the light emitted from the organic light emitting element L1 may be minimized in the process of being emitted to the outside through the optical member 58.

Next, look at the path of the light introduced from the outside as follows.

External light is linearly polarized in the polarization axis direction of the polarizing plate 581 while passing through the polarizing plate 581. This linearly polarized light becomes right circularly polarized light while passing through the second phase retardation plate 582 and is directed to the corner cube film 583.

The corner cube film 583 reflects a substantial portion of the light incident through the polarizing plate 581 and the second phase retardation plate 582 in parallel to the incident direction. The remaining part is directed to the first phase delay plate 584.

A considerable amount of light reflected by the corner cube film 583 is lost again through the second phase retardation plate 582 and the polarizing plate 581, or reflected in parallel with the incident direction. Therefore, from the viewpoint of the user looking at the organic light emitting diode display 100, it is possible to effectively suppress deterioration of visibility due to external light reflection.

Meanwhile, light passing through the corner cube film 583 is linearly polarized while passing through the first phase retardation plate 584. This linearly polarized light passes through the reflective polarizing film 585 and is directed to the common electrode 546.

As described above, the light introduced from the outside may be reflected by the corner cube film 583 in a substantial part, and thus the reflection of external light may be suppressed. Accordingly, the organic light emitting diode display 100 may effectively suppress reflection of external light to improve visibility and minimize loss of light emitted from the organic light emitting layer 545 to the outside. That is, display characteristics of the organic light emitting diode display 100 may be improved.

In addition, the organic light emitting diode display 100 may efficiently emit light generated by the organic light emitting diode L1 to the outside, thereby reducing power consumption and improving lifespan.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the following claims. Those who are engaged in the technology field will understand easily.

1 is a partial cross-sectional view of an organic light emitting diode display according to an exemplary embodiment.

FIG. 2 is a layout view illustrating a circuit arrangement of a driving circuit unit and an organic light emitting diode of the organic light emitting diode display of FIG. 1.

3 is a plan view illustrating a corner cube layer used in the OLED display of FIG. 1.

4 is a cross-sectional view illustrating a path of light introduced into the OLED display of FIG. 1 from outside and a path of light emitted from the OLED.

Claims (10)

An organic light emitting device including a pixel electrode, an organic emission layer formed on the pixel electrode, and a common electrode formed on the organic emission layer; A reflective polarizing film formed on the common electrode of the organic light emitting device; A first phase retardation plate formed on the reflective polarizing film; A corner cube film formed on the first phase retardation plate; A second phase retardation plate formed on the corner cube film; And Polarizing plate formed on the second phase retardation plate An organic light emitting display device comprising a. In claim 1, The corner cube film includes a corner cube layer in which a plurality of corner cubes are formed, and a cover layer covering one surface of the corner cube layer in which the corner cubes are formed. In claim 2, The corner cube of the corner cube layer protrudes toward the first phase retardation plate. 4. The method of claim 3, The corner cube layer has a larger refractive index than the cover layer. In claim 2, The cover layer has an adhesive force. In claim 5, The cover layer is disposed between the corner cube layer and the first phase retardation plate to bond the corner cube layer and the first phase retardation plate to each other. In claim 1, And at least two of the reflective polarizing film, the first phase retardation plate, the corner cube film, the second phase retardation plate, and the polarizing plate are integrally formed. The method according to any one of claims 1 to 7, The polarizing plate and the reflective polarizing film have the same polarization axis. In claim 8, The first phase retardation plate and the second phase retardation plate have the same optical axis, and are each a quarter wave plate. In claim 9, And an intersection of an optical axis of the first phase retardation plate and the second phase retardation plate with a polarization axis of the polarizing plate and the reflective polarizing film is 45 degrees.

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