KR102334953B1 - Display Device And Method For Driving Of The Same - Google Patents

Abstract

The present invention relates to a display device, and more particularly, to a display device capable of selectively implementing a wide viewing angle mode and a narrow viewing angle mode, and a driving method thereof. A display device according to an embodiment of the present invention includes a plurality of pixels each including a first sub-pixel and a second sub-pixel. The first subpixel includes a first light emitting unit and is partitioned by a first bank layer. The second subpixel includes a second light emitting unit and is divided into a first bank layer and a second bank layer having a height different from that of the first bank layer. The first light emitting part of the first subpixel and the second light emitting part of the second subpixel have different areas and emit the same color.

Description

Display Device And Method For Driving Of The Same

The present invention relates to a display device, and more particularly, to a display device capable of selectively implementing a wide viewing angle mode and a narrow viewing angle mode, and a driving method thereof.

As the information society develops, the demand for a display device for displaying an image is increasing in various forms. The display device field has rapidly changed to a thin, light, and large-area Flat Panel Display Device (FPD) that replaces a bulky cathode ray tube (CRT). Flat panel displays include Liquid Crystal Display Device (LCD), Plasma Display Panel (PDP), Organic Light Emitting Display Device (OLED), and Electrophoretic Display Device. : ED), etc.

Among them, the organic light emitting display device is a self-luminous device that emits light by itself, and has advantages of fast response speed, luminous efficiency, luminance, and viewing angle. In particular, the organic light emitting display device can be formed on a flexible plastic substrate, and can be driven at a lower voltage than a plasma display panel or an inorganic electroluminescent (EL) display and consume relatively little power. It has the advantage of being small and the color is excellent.

Recently, the use of portable devices such as mobile devices and laptops has become popular. Portable devices are widely used not only at home, but also in offices, public transportation such as buses and subways, and in public places where there are many people around, such as libraries. Therefore, only the user himself wishes to obtain information using the portable device, and hopes that the information displayed on the portable device is not shown to others.

To this end, the display of the portable device is provided with a privacy film that narrows the viewing angle. However, in the case of privacy film, there is a problem in that the film must be detached/attached for use and cannot be applied to mobile devices that can rotate the screen.

Accordingly, the present invention provides a display device capable of selectively driving a wide viewing angle mode and a narrow viewing angle mode to reduce manufacturing cost and applicable to a mobile device, and a driving method thereof.

In order to achieve the above object, a display device according to an embodiment of the present invention includes a plurality of pixels each including a first sub-pixel and a second sub-pixel. The first subpixel includes a first light emitting unit and is partitioned by a first bank layer. The second subpixel includes a second light emitting unit and is divided into a first bank layer and a second bank layer having a height different from that of the first bank layer. The first light emitting part of the first subpixel and the second light emitting part of the second subpixel have different areas and emit the same color.

The area of the first light emitting part is smaller than the area of the second light emitting part.

The height of the first bank layer is higher than the height of the second bank layer.

The first subpixel and the second subpixel each include a first electrode, an organic layer disposed on the first electrode and including at least a light emitting layer, and a second electrode disposed on the organic layer.

The first electrode is a reflective electrode and the second electrode is a transflective electrode.

It further includes an auxiliary electrode positioned on the second electrode.

In the second subpixel, the second electrode is a transmissive electrode.

In the first subpixel, the second electrode is a transflective electrode and further includes an auxiliary electrode positioned on the second electrode, and in the second subpixel, the second electrode is an auxiliary electrode extending from the first subpixel.

The first bank layer is made of a material having a lower reflectance than the second bank layer.

In addition, a method of driving a display device according to an exemplary embodiment of the present invention includes a first light emitting unit, a first subpixel partitioned by a first bank layer, and a second light emitting unit, and includes a first bank layer and a first light emitting unit. a plurality of pixels each including a second subpixel partitioned by a second bank layer having a height different from that of the bank layer, wherein the first light emitting part of the first subpixel and the second light emitting part of the second subpixel are different from each other In a display device having an area but emitting the same color, in the narrow viewing angle mode, only the first sub-pixel is driven to emit light, and in the wide viewing angle mode, the first sub-pixel and the second sub-pixel are driven together to emit light as one pixel. .

In the narrow viewing angle mode, the second sub-pixel of the plurality of pixels is not driven.

First, according to the present invention, one pixel is divided into two sub-pixels and the height of the bank layer is formed to be different, so that the first sub-pixel having a narrow viewing angle and the second sub-pixel having a wide viewing angle can be provided. Accordingly, the narrow viewing angle mode and the wide viewing angle mode may be selectively driven by emitting only the first sub-pixel or both the first and second sub-pixels.

Second, the present invention has an advantage in that a short circuit of the second electrode that may occur at the edge of the first bank layer can be covered by further forming an auxiliary electrode on the second electrode.

Third, according to the present invention, the viewing angle due to the micro-cavity effect can be further narrowed by providing the second electrode in the first sub-pixel, and the viewing angle can be further widened by including the transparent auxiliary electrode in the second sub-pixel without the second electrode There is this.

Fourth, according to the present invention, the viewing angle can be further narrowed by using a material having low transmittance and low reflectance so as to absorb light in the first bank layer of the first subpixel, and the second bank layer of the second subpixel SP2 is By using a material having a higher reflectance than the first bank layer, there is an advantage in that the viewing angle can be further widened.

Accordingly, the present invention has advantages in that there is no need to etch the substrate, thereby reducing manufacturing cost and realizing a wide viewing angle even when the display device is rotated by having sub-pixels capable of realizing a wide viewing angle.

1 is a schematic block diagram of an organic light emitting diode display;
2 is a first exemplary diagram illustrating a circuit configuration of a sub-pixel;
3 is a second exemplary diagram illustrating a circuit configuration of a sub-pixel;
4 is a cross-sectional view of a sub-pixel of an organic light emitting diode display;
5 is a plan view illustrating an organic light emitting display device according to a first embodiment of the present invention.
6 is a view showing a cross-section taken along line I-I' of FIG.
7 is a view showing a cross-section taken along II-II' of FIG. 5;
8 and 9 are graphs showing the relationship between the height of the bank layer according to the viewing angle.
10 is a graph illustrating a relationship between a visible area of a light emitting part according to a viewing angle;
11 is a graph showing luminance according to a viewing angle;
12 is a plan view illustrating an organic light emitting display device driven in a wide viewing angle mode;
13 is a plan view illustrating an organic light emitting display device driven in a narrow viewing angle mode;
14 is a cross-sectional view of an organic light emitting display device according to a second exemplary embodiment of the present invention.
15 is a cross-sectional view of an organic light emitting display device according to a third exemplary embodiment of the present invention.
16 is a cross-sectional view of an organic light emitting diode display according to a fourth embodiment of the present invention;

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Like reference numerals refer to substantially identical elements throughout. In the following description, if it is determined that a detailed description of a known technology or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, component names used in the following description may be selected in consideration of the ease of writing the specification, and may be different from the component names of the actual product. In addition, in the case of the description of the positional relationship, for example, when the positional relationship of the two parts is described as 'on', 'on', 'on', 'next to', ' One or more other parts may be positioned between the two parts unless the terms 'directly' or 'adjacent' are used together.

An organic light emitting display device, a liquid crystal display device, an electrophoretic display device, etc. can be used as the display device according to the present invention. In the present invention, the organic light emitting display device will be described as an example. An organic light emitting display device includes a light emitting layer made of an organic material between a first electrode and a second electrode. Therefore, the hole supplied from the first electrode and the electron supplied from the second electrode combine in the light emitting layer to form an exciton, a hole-electron pair, and emit light by the energy generated when the exciton returns to the ground state. It is a light emitting display device.

In addition, in the display device according to the present invention, the pixel arrangement is composed of one RGB unit pixel and arranged in a stripe. However, the present invention is not limited thereto, and RGBW consists of one unit pixel or various pixel arrangement methods such as a pentile method may be applied.

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

1 is a schematic block diagram of an organic light emitting diode display, FIG. 2 is a first exemplary diagram illustrating a circuit configuration of a sub-pixel, and FIG. 3 is a second exemplary diagram illustrating a circuit configuration of a sub-pixel.

Referring to FIG. 1 , the organic light emitting display device includes an image processor 10 , a timing controller 20 , a data driver 30 , a gate driver 40 , and a display panel 50 .

The image processing unit 10 outputs a data enable signal DE along with the data signal DATA supplied from the outside. The image processing unit 10 may output one or more of a vertical synchronization signal, a horizontal synchronization signal, and a clock signal in addition to the data enable signal DE, but these signals are omitted for convenience of description. The image processing unit 10 is formed in the form of an IC (Integrated Circuit) on the system circuit board.

The timing controller 20 receives the data signal DATA from the image processing unit 10 as well as a driving signal including a data enable signal DE or a vertical synchronization signal, a horizontal synchronization signal, and a clock signal.

The timing controller 20 includes a gate timing control signal GDC for controlling an operation timing of the gate driver 40 and a data timing control signal DDC for controlling an operation timing of the data driver 30 based on the driving signal. to output The timing controller 20 is formed in the form of an IC on the control circuit board.

The data driver 30 samples and latches the data signal DATA supplied from the timing controller 20 in response to the data timing control signal DDC supplied from the timing controller 20 , converts it into a gamma reference voltage, and outputs it . The data driver 30 outputs the data signal DATA through the data lines DL1 to DLn. The data driver 30 is attached to the substrate in the form of an IC.

The gate driver 40 outputs a gate signal while shifting the level of the gate voltage in response to the gate timing control signal GDC supplied from the timing controller 20 . The gate driver 40 outputs a gate signal through the gate lines GL1 to GLm. The gate driver 40 is formed in the form of an IC on the gate circuit board or in the form of a gate in panel on the display panel 50 .

The display panel 50 displays an image in response to the data signal DATA and the gate signal supplied from the data driver 30 and the gate driver 40 . The display panel 50 includes sub-pixels SP displaying an image.

Referring to FIG. 2 , one sub-pixel includes a switching transistor SW, a driving transistor DR, a compensation circuit CC, and an organic light emitting diode (OLED). The organic light emitting diode OLED operates to emit light according to a driving current formed by the driving transistor DR.

The switching transistor SW performs a switching operation such that the data signal supplied through the first data line DL1 is stored as a data voltage in the capacitor in response to the gate signal supplied through the first gate line GL1 . The driving transistor DR operates so that a driving current flows between the high potential power line VDD and the low potential power line GND according to the data voltage stored in the capacitor. The compensation circuit CC is a circuit for compensating the threshold voltage of the driving transistor DR. Also, a capacitor connected to the switching transistor SW or the driving transistor DR may be located inside the compensation circuit CC.

The compensation circuit CC is composed of one or more thin film transistors and a capacitor. The configuration of the compensation circuit CC varies greatly depending on the compensation method, and detailed examples and descriptions thereof will be omitted.

In addition, as shown in FIG. 3 , when the compensation circuit CC is included, the sub-pixel further includes a signal line and a power supply line for driving the compensation thin film transistor and supplying a specific signal or power. The added signal line may be defined as the first-second gate line GL1b for driving the compensation thin film transistor included in the sub-pixel. In addition, the added power line may be defined as an initialization power line INIT for initializing a specific node of the sub-pixel to a specific voltage. However, this is only an example and is not limited thereto.

Meanwhile, in FIGS. 2 and 3 , the compensation circuit CC is included in one sub-pixel as an example. However, when the subject of compensation is located outside the sub-pixel, such as the data driver 30 , the compensation circuit CC may be omitted. That is, one sub-pixel is basically composed of a 2T (Transistor) 1C (Capacitor) structure including a switching transistor (SW), a driving transistor (DR), a capacitor, and an organic light emitting diode (OLED), but a compensation circuit (CC) When is added, it may be variously configured as 3T1C, 4T2C, 5T2C, 6T2C, 7T2C, and the like.

In addition, although the compensation circuit CC is shown to be positioned between the switching transistor SW and the driving transistor DR in FIGS. 2 and 3 , it may be further positioned between the driving transistor DR and the organic light emitting diode (OLED). may be The position and structure of the compensation circuit CC are not limited to FIGS. 2 and 3 .

Hereinafter, a cross-sectional structure of a sub-pixel SP of an organic light emitting diode display will be described with reference to FIG. 4 of the present invention. 4 is a cross-sectional view of a sub-pixel of an organic light emitting diode display.

Referring to FIG. 4 , in the organic light emitting diode display according to an embodiment of the present invention, a first buffer layer BUF1 is positioned on a substrate PI. The substrate PI is made of plastic and may be, for example, a polyimide substrate. Accordingly, the substrate PI of the present invention has a flexible characteristic. The first buffer layer BUF1 serves to protect the thin film transistor formed in a subsequent process from impurities such as alkali ions leaking from the substrate PI. The first buffer layer BUF1 may be formed of silicon oxide (SiOx), silicon nitride (SiNx), or a multilayer thereof.

A shield layer LS is positioned on the first buffer layer BUF1. The shield layer LS serves to prevent a decrease in panel driving current that may be generated by using the polyimide substrate. A second buffer layer BUF2 is positioned on the shield layer LS. The second buffer layer BUF2 serves to protect the thin film transistor formed in a subsequent process from impurities such as alkali ions leaking from the shield layer LS. The second buffer layer BUF2 may be formed of silicon oxide (SiOx), silicon nitride (SiNx), or a multilayer thereof.

The semiconductor layer ACT is positioned on the second buffer layer BUF2 . The semiconductor layer ACT may be formed of a silicon semiconductor or an oxide semiconductor. The silicon semiconductor may include amorphous silicon or crystallized polycrystalline silicon. Here, polycrystalline silicon has high mobility (100cm2/Vs or more), low energy consumption, and excellent reliability. have. On the other hand, since the oxide semiconductor has a low off-current, it is suitable for a switching TFT that has a short on-time and a long off-time. In addition, since the off current is small, the voltage holding period of the pixel is long, which is suitable for a display device requiring low-speed driving and/or low power consumption. In addition, the semiconductor layer ACT includes a drain region and a source region including p-type or n-type impurities, and includes a channel therebetween.

A gate insulating layer GI is positioned on the semiconductor layer ACT. The gate insulating layer GI may be formed of silicon oxide (SiOx), silicon nitride (SiNx), or a multilayer thereof. The gate electrode GA is positioned on the gate insulating layer GI in a predetermined region of the semiconductor layer ACT, that is, in a position corresponding to the channel in which the impurity is implanted. The gate electrode GA is selected from the group consisting of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu). It is formed of any one or an alloy thereof. In addition, the gate electrode GA is a group consisting of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu). It may be a multi-layer made of any one selected from or alloys thereof. For example, the gate electrode GA may be a double layer of molybdenum/aluminum-neodymium or molybdenum/aluminum.

An interlayer insulating layer ILD that insulates the gate electrode GA is disposed on the gate electrode GA. The interlayer insulating layer ILD may be a silicon oxide layer (SiOx), a silicon nitride layer (SiNx), or a multilayer thereof. Contact holes CH exposing a portion of the semiconductor layer ACT are positioned in partial regions of the interlayer insulating layer ILD and the gate insulating layer GI.

A drain electrode DE and a source electrode SE are positioned on the interlayer insulating layer ILD. The drain electrode DE is connected to the semiconductor layer ACT through a contact hole CH exposing the drain region of the semiconductor layer ACT, and the source electrode SE exposes the source region of the semiconductor layer ACT. It is connected to the semiconductor layer ACT through the contact hole CH. The source electrode SE and the drain electrode DE may be formed of a single layer or a multilayer, and when the source electrode SE and the drain electrode DE are a single layer, molybdenum (Mo), aluminum (Al), chromium It may be made of any one selected from the group consisting of (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or an alloy thereof. In addition, when the source electrode SE and the drain electrode DE are multi-layered, a double layer of molybdenum/aluminum-neodymium, a triple layer of titanium/aluminum/titanium, molybdenum/aluminum/molybdenum or molybdenum/aluminum-neodymium/molybdenum can be made with

Accordingly, the thin film transistor TFT including the semiconductor layer ACT, the gate electrode GA, the drain electrode DE, and the source electrode SE is configured.

An inorganic layer IOL is positioned on a substrate PI including a thin film transistor TFT. The inorganic layer IOL is an insulating layer that protects an underlying device, and may be a silicon oxide layer (SiOx), a silicon nitride layer (SiNx), or a multilayer thereof. An overcoat layer (OC) is positioned on the inorganic layer (IOL). The overcoat layer OC may be a planarization layer for alleviating a step difference in a lower structure, and is made of an organic material such as polyimide, benzocyclobutene series resin, or acrylate. The overcoat layer OC may be formed by a method such as spin on glass (SOG) in which the organic material is coated in a liquid form and then cured.

A via hole VIA exposing the drain electrode DE is positioned in a partial region of the overcoat layer OC. An organic light emitting diode (OLED) is positioned on the overcoat layer (OC). In more detail, the first electrode ANO is positioned on the overcoat layer OC. The first electrode ANO acts as an anode and is connected to the drain electrode DE of the thin film transistor TFT through the via hole VIA. The first electrode ANO may be formed of a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), or zinc oxide (ZnO). When the first electrode ANO is a reflective electrode, the first electrode ANO further includes a reflective layer. The reflective layer may be made of aluminum (Al), copper (Cu), silver (Ag), nickel (Ni), or an alloy thereof, preferably APC (silver/palladium/copper alloy).

A bank layer BNK partitioning pixels is positioned on the substrate PI including the first electrode ANO. The bank layer BNK may be formed of an organic material such as polyimide, benzocyclobutene series resin, or acrylate. Also, the bank layer BNK may include a black bank layer capable of absorbing light including a black pigment. In addition, the bank layer BNK may be made of a material having a high reflectance and a low refractive index. In the bank layer BNK, the pixel defining part OP exposing the first electrode ANO is positioned. An organic layer LEL in contact with the first electrode ANO is positioned in the pixel defining portion OP of the bank layer BNK. The organic layer LEL includes a light emitting layer in which at least electrons and holes are combined to emit light, and may include a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, and the like.

The second electrode CAT is positioned on the organic layer LEL. The second electrode CAT is positioned on the entire surface of the display area A/A, and may be formed of magnesium (Mg), calcium (Ca), aluminum (Al), silver (Ag), or an alloy thereof having a low work function. . The second electrode CAT is a semi-transmissive electrode and has a thickness that is thin enough to partially transmit light.

On the other hand, the present invention discloses an organic light emitting display device that can be switched to implement a wide viewing angle mode and a narrow viewing angle mode. Hereinafter, the configuration of the lower portion of the organic light emitting diode (OLED) illustrated in FIG. 4 will be omitted and the configuration of the upper portion of the organic light emitting diode (OLED) will be described in detail.

<First embodiment>

5 is a plan view illustrating an organic light emitting display device according to a first embodiment of the present invention, FIG. 6 is a cross-sectional view taken along line I-I' in FIG. 5, and FIG. 7 is II-II of FIG. ', FIGS. 8 and 9 are graphs showing the height relationship of the bank layer according to the viewing angle, FIG. 10 is a graph showing the relationship between the visible area of the light emitting part according to the viewing angle, and FIG. 11 is the viewing angle It is a graph showing the luminance according to

Referring to FIG. 5 , in the organic light emitting diode display according to the first embodiment of the present invention, a plurality of pixels MSP are disposed on a substrate. For example, the pixels MSP emitting red (R) are arranged in one row, the pixels MSP emitting green (G) are arranged in the second row, and pixels emitting blue (B) are arranged in the second row. (MSP) may be arranged in 3 rows. Each of the pixels MSP includes a first sub-pixel SP1 and a second sub-pixel SP2 emitting the same color and is disposed to extend in the x-direction.

Taking one pixel MSP as an example, in the first sub-pixel SP1 , the first light emitting part LEP1 having a predetermined area is partitioned by the first bank layer BK1 . The left and right sides of the second sub-pixel SP2 are partitioned by the first bank layer BK1 and the top and bottom sides are partitioned by the second bank layer BK2, so that the second light emitting part LEP2 having a predetermined area is partitioned. The first bank layer BK1 and the second bank layer BK2 may be a black bank layer having low light transmittance and low reflectance, or a reflective bank layer having high light reflectance and low refractive index. Hereinafter, it will be described as an example that the first bank layer BK1 and the second bank layer BK2 are formed of a black bank layer.

The area of the first light-emitting part LEP1 of the first sub-pixel SP1 is different from the area of the second light-emitting part LEP2 of the second sub-pixel SP2. For example, the area of the first light emitting part LEP1 of the first subpixel SP1 is smaller than the area of the second light emitting part LEP2 of the second subpixel SP2 .

As shown in FIG. 6 , when the area of the first light emitting part LEP1 is relatively smaller than the area of the second light emitting part LEP2 , a large amount of light emitted from the first light emitting part LEP1 is Light is absorbed by the first bank layer BK1 and the remaining small amount of light is not absorbed by the first bank layer BK1 and is emitted upward. Accordingly, as the angle range of the upwardly emitted light becomes smaller, the viewing angle becomes smaller from the user's point of view. On the other hand, when the area of the second light emitting part LEP2 is relatively larger than that of the first light emitting part LEP1 , a small amount of light emitted from the second light emitting part LEP2 is transmitted to the first bank layer BK1 . ) and the remaining large amount of light is not absorbed by the first bank layer BK1 but is emitted upward. Accordingly, as the angle range of the upwardly emitted light increases, the viewing angle increases from the user's point of view.

Referring to FIG. 5 , in the present invention, in order to form different viewing angles of the first sub-pixel SP1 and the sub-second pixel SP2, the heights of the first bank layer BK1 and the second bank layer BK2 are increased. form differently. In more detail, in order to reduce the viewing angle of the first light emitting part LEP1 of the first subpixel SP1 , the height H1 of the first bank layer BK1 surrounding the first light emitting part LEP1 is formed to be high. do. In addition, in order to increase the viewing angle of the second light emitting part LEP2 of the second subpixel SP2, the height H2 of the second bank layer BK2 surrounding a part of the second light emitting part LEP2 is set to the first bank. It is formed to be lower than the height H1 of the layer BK1. Here, the second bank layer BK2 is disposed in an area other than the first bank layer BK1 , and specifically, is disposed to correspond to the long side of the second light emitting part LEP2 of the second subpixel SP2 . For example, the first bank layer BK1 is disposed on the left and right short sides of the second light emitting part LEP2 of the second subpixel SP2 , and the second light emitting part LEP2 of the second subpixel SP2 is disposed. A second bank layer BK2 is disposed on the upper and lower long sides of the .

As shown in FIG. 7 , the height H2 of the second bank layer BK2 disposed on the upper and lower sides of the second light emitting part LEP2 is the first bank layer disposed on the left and right sides of the second light emitting part LEP2 . It is formed lower than the height H1 of (BK1). In this case, the light emitted toward the first bank layer BK1 among the light emitted from the second light emitting unit LEP2 is absorbed by the first bank layer BK1, and the remaining unabsorbed light is absorbed by the first bank layer (BK1). BK1) is emitted at a large angle upward. And, of the light emitted from the second light emitting part LEP2, the light emitted toward the second bank layer BK2 is partially absorbed by the second bank layer BK2, but most of the light emitted from the second light emitting part LEP2 is low due to the low height of the second bank layer BK2. Light is emitted at a small angle onto the second bank layer BK2. Accordingly, the angle range of the light emitted above the second bank layer BK2, which is lower than the first bank layer BK1, is increased, and thus the viewing angle is increased from the user's point of view.

Meanwhile, the heights of the bank layers BK1 and BK2 may be adjusted according to the viewing angles of the respective subpixels SP1 and SP2 . Hereinafter, the first sub-pixel SP1 will be described as an example, but all other sub-pixels including the second sub-pixel SP2 are equally applied.

Referring to FIG. 8 , assuming that the width of the first light emitting part LEP1 of the first subpixel SP1 is 1 and the viewing angle of the first subpixel SP1 is set to 40 degrees, the first bank layer BK1 The height of is tan50 degrees, so the value is 1.19. That is, when the width of the first light emitting part LEP1 is 1, the ratio of the height of the first bank layer BK1 to the width of the first light emitting part LEP1 is 1.19. Expressing this in a simple formula, the height ratio of the first bank layer can be expressed as tan(90-θ) (where θ is the viewing angle). For example, if the width of the first light emitting part LEP1 is 1 μm and the viewing angle is set to 40 degrees, the height of the first bank layer BK1 is 1.19 μm.

Also, referring to FIG. 9 , assuming that the width of the first light emitting part LEP1 of the first subpixel SP1 is 1 and the viewing angle of the first subpixel SP1 is set to 30 degrees, the first bank layer ( The height of BK1) is tan60 degrees, so the value is 1.73. That is, when the width of the first light emitting part LEP1 is 1, the ratio of the height of the first bank layer BK1 to the width of the first light emitting part LEP1 is 1.73. For example, if the width of the first light emitting part LEP1 is 1 μm and the viewing angle is set to 30 degrees, the height of the first bank layer BK1 is 1.73 μm. Accordingly, according to the present invention, the height of the bank layer can be adjusted according to the viewing angle for each size of the light emitting part of various sub-pixels.

Also, according to the present invention, after the height of the bank layer of each subpixel is determined, the width of the visible area of the light emitting unit can be known according to the viewing angle range, and thus the luminance according to the viewing angle of the subpixels can be known.

Referring to FIG. 10 , as described above, when the viewing angle of the first sub-pixel SP1 is 40 degrees, the height of the first bank layer BK1 is 1.19 because tan50 degrees. That is, since the maximum viewing angle of the first sub-pixel SP1 is 40 degrees, the width of the visible area of the first light emitting unit LEP1 in a predetermined viewing angle range may be calculated. For example, the width of the visible area of the first light emitting part LEP1 that can be seen by the user in the viewing angle range of 30 to 40 degrees is tanθ (here, the height 1.19) of the first bank layer BK1 when the viewing angle is 40 degrees , θ can be obtained by subtracting a value multiplied by the minimum viewing angle of 30 degrees from 1 (the width of the first light emitting part LEP1 when the viewing angle is 40 degrees). That is, it can be expressed as 1-(tan(90-40)tan30). Therefore, the width (1-x) of the visible area when the viewing angle is 30 to 40 degrees can be calculated as 0.3119.

Referring to FIG. 11 , when the width of the visible area of the first light emitting part LEP1 according to the viewing angle is obtained, the luminance according to the viewing angle of the sub-pixels can be obtained by calculating the width of the visible area as a ratio of the width of the entire light emitting part. For example, in the case of a pixel having a viewing angle of 30 degrees maximum, an intensity of 0.4 appears when the viewing angle is 20 degrees when the intensity when the viewing angle is 0 degrees is 1. In addition, in the case of a pixel with a viewing angle of 40 degrees maximum, an intensity of 0.8 is exhibited when the viewing angle is 10 degrees, and an intensity of 0.6 is exhibited when the viewing angle is 20 degrees.

Based on the above description, each of the pixels MSP of the present invention may include a first sub-pixel SP1 having a narrow viewing angle and a second sub-pixel SP2 having a wide viewing angle. Accordingly, the present invention can selectively drive the narrow viewing angle mode for viewing the display only by itself and the wide viewing angle mode for not viewing the display. Hereinafter, a driving method of the narrow viewing angle mode and the wide viewing angle mode of the organic light emitting diode display of the present invention will be described.

12 is a plan view illustrating an organic light emitting display device driven in a wide viewing angle mode, and FIG. 13 is a plan view illustrating an organic light emitting display device driven in a narrow viewing angle mode.

Referring to FIG. 12 , in the organic light emitting diode display of the present invention, a plurality of pixels MSP are disposed on a substrate. For example, the pixels MSP emitting red (R) are arranged in one row, the pixels MSP emitting green (G) are arranged in the second row, and pixels emitting blue (B) are arranged in the second row. (MSP) is arranged in row 3. Each of the pixels MSP includes a first sub-pixel SP1 and a second sub-pixel SP2 emitting the same color and is disposed to extend in the x-direction. The first sub-pixels SP1 of each of the pixels MSP are arranged in odd-numbered columns, and the second sub-pixels SP2 are arranged in even-numbered columns. Conversely, the first sub-pixels SP1 of each of the pixels MSP may be arranged in an even-numbered column, and the second sub-pixels SP2 may be arranged in an odd-numbered column. The data lines, gate lines, and power lines described in FIGS. 2 to 4 are allocated to the first subpixel SP1 and the second subpixel SP2 of each of the pixels MSP, and switching transistors, driving Transistors and the like may be provided to be individually driven according to each signal.

In the wide viewing angle mode, the first sub-pixel SP1 and the second sub-pixel SP2 are equally driven as one pixel MSP to emit light. Specifically, when a red light is emitted, a gate signal is applied to each of the first sub-pixel SP1 and the second sub-pixel SP2 , and as the switching transistor is switched, the data signal supplied through the data line is stored in the capacitor. . The driving transistor operates so that a driving current flows through the organic light emitting diode according to the data voltage stored in the capacitor, thereby emitting red light in the first sub-pixel SP1 and the second sub-pixel SP2, respectively. In the green and blue pixels, the first sub-pixel and the second sub-pixel are equally driven as one pixel to emit light. Accordingly, in the wide viewing angle mode, both the first subpixel SP1 having a narrow viewing angle and the second subpixel SP having a wide viewing angle emit light, thereby realizing a wide viewing angle.

Referring to FIG. 13 , in the narrow viewing angle mode, only the first subpixel SP1 having a narrow viewing angle is driven to emit light, and the second subpixel SP2 having a wide viewing angle is not driven. Only the first sub-pixel SP1 is driven by applying the gate signal and the data signal, and the second sub-pixel SP2 is not driven because the gate signal and the data signal are not applied. For example, the first sub-pixel of the red pixel Only the pixel SP1 is driven to emit red light emitted at a narrow viewing angle. In addition, the second sub-pixel SP2 of the red pixel is not driven and is displayed as black. Accordingly, in the narrow viewing angle mode, only the first sub-pixel SP1 having a narrow viewing angle emits light, thereby realizing a narrow viewing angle.

As described above, in the organic light emitting display device according to the first embodiment of the present invention, one pixel is divided into two sub-pixels and the height of the bank layer is formed differently, so that the first sub-pixel with a narrow viewing angle and the first sub-pixel with a wide viewing angle are divided into two sub-pixels. A second sub-pixel may be provided. Accordingly, the narrow viewing angle mode and the wide viewing angle mode may be selectively driven by emitting only the first sub-pixel or both the first and second sub-pixels.

<Second embodiment>

14 is a cross-sectional view of an organic light emitting display device according to a second exemplary embodiment of the present invention. Hereinafter, a description of the same configuration as that of the above-described first embodiment will be omitted.

Referring to FIG. 14 , the first bank layer BK1 of the present invention is formed to have a high height to narrow the viewing angle of the light emitted from the first sub-pixel SP1 . As the height of the first bank layer BK1 increases, the taper angle increases. The second electrode CAT disposed on the first bank layer BK1 is a transflective electrode and is generally made of metal, for example, magnesium (Mg), silver (Ag), aluminum (Al), or an alloy thereof. is sputtered to form a very thin layer. However, if the height of the first bank layer BK1 is high and the taper angle is increased, the step coverage of sputtering may be deteriorated, and thus the second electrode CAT may be shorted at the edge of the first bank layer BK1 .

Accordingly, in the present invention, the auxiliary electrode AE is formed on the second electrode CAT so that power is supplied to the second electrode CAT even when the second electrode CAT is short-circuited. The auxiliary electrode AE may be formed of a transparent material so that light passing through the second electrode CAT may be emitted upward. The auxiliary electrode AE may be made of, for example, indium zinc oxide (IZO). The thickness of the auxiliary electrode AE is sufficient to allow light to pass through and to cover the short circuit of the second electrode CAT, and may be, for example, 50 to 1000 nm. However, the thickness of the auxiliary electrode AE is not limited thereto.

As described above, in the organic light emitting diode display according to the second embodiment of the present invention, an auxiliary electrode is formed on the second electrode to cover a short circuit of the second electrode that may occur at the edge of the first bank layer. There is an advantage.

<Third embodiment>

15 is a cross-sectional view of an organic light emitting display device according to a third exemplary embodiment of the present invention. Hereinafter, descriptions of the same components as those of the above-described first and second embodiments will be omitted.

Referring to FIG. 15 , the light emitted from the first sub-pixel SP1 of the present invention has a narrow viewing angle, and the light emitted from the second sub-pixel SP2 has a wide viewing angle. In addition to adjusting the height of the bank layers as in the above-described first embodiment, the viewing angle of light may be adjusted by changing the arrangement of the second electrode CAT.

More specifically, in the first subpixel SP1 of the present invention, the second electrode CAT may be provided on the first organic layer LEL1 and the auxiliary electrode AE may be disposed on the second electrode CAT. have. On the other hand, in the second subpixel SP2 , the auxiliary electrode AE may be disposed on the second organic layer LEL2 without the second electrode CAT. As described above, the second electrode CAT is a transflective electrode and the auxiliary electrode AE is a transparent electrode. In the first subpixel SP1 , when the first electrode ANO is a reflective electrode and the second electrode CAT is a transflective electrode, some of the light emitted from the first organic layer LEL1 is transmitted to the second electrode CAT ), but a portion is reflected from the second electrode CAT and proceeds to the lower first electrode ANO again. The light propagating to the first electrode ANO is reflected back upward and is reinforced with light emitted from the first organic layer LEL1 or other light, thereby generating a microcavity effect in which luminance is increased. As the microcavity effect increases, the viewing angle becomes narrower. In the present invention, the viewing angle due to the micro-cavity effect can be further narrowed by providing the second electrode CAT, which is a transflective electrode, in the first sub-pixel SP1.

On the other hand, the second sub-pixel SP2 does not include the second electrode CAT, but includes the auxiliary electrode AE, which is a transparent electrode. The auxiliary electrode AE is disposed in all pixels and is disposed even in an area where the second electrode CAT is not present. In the second sub-pixel SP2 , the auxiliary electrode AE functions as a cathode. Since most of the light emitted from the second emission layer LEL2 of the second sub-pixel SP2 passes through the transparent auxiliary electrode AE, the micro-cavity effect hardly occurs. Accordingly, since there is almost no micro-cavity effect, the viewing angle of light is widened accordingly. In the present invention, since the second sub-pixel SP2 does not include the second electrode CAT, which is the transflective electrode, and the transparent auxiliary electrode AE is used as a cathode, the viewing angle can be further increased.

That is, in the third exemplary embodiment of the present invention, in the first subpixel, the second electrode covers the first light emitting part, but in the second subpixel, the second electrode does not cover the second light emitting part. Accordingly, it is possible to further narrow the viewing angle due to the micro-cavity effect by providing the second electrode in the first sub-pixel, and to provide the second sub-pixel with the transparent auxiliary electrode without the second electrode to further widen the viewing angle.

<Fourth embodiment>

16 is a cross-sectional view of an organic light emitting display device according to a fourth exemplary embodiment of the present invention. Hereinafter, descriptions of the same components as those of the above-described first to third embodiments will be omitted.

Referring to FIG. 16 , the light emitted from the first sub-pixel SP1 of the present invention has a narrow viewing angle, and the light emitted from the second sub-pixel SP2 has a wide viewing angle. In addition to adjusting the height of the bank layers as in the first embodiment described above, the viewing angle of light may be adjusted by changing the material of the bank layers.

More specifically, the first bank layer BK1 partitioning the first sub-pixel SP1 may be made of a material having low transmittance and low reflectance. For example, the first bank layer BK1 may be a black bank layer capable of absorbing light including a black pigment. Among the light emitted from the first sub-pixel SP1 , the light emitted to the side is absorbed by the first bank layer BK1 and the light emitted to the front is emitted. Accordingly, the first bank layer BK1 of the first sub-pixel SP1 may absorb the light emitted laterally to narrow the viewing angle of the finally emitted light.

The second bank layer BK2 partitioning the second subpixel SP2 may be made of a material having a high reflectance and a low refractive index. The reflectivity of the second bank layer BK2 may be relatively higher than that of the first bank layer BK1 . For example, the second bank layer BK2 may be made of an acryl-based material. Among the lights emitted from the second sub-pixel SP2 , the light emitted to the side is reflected from the second bank layer BK2 and emitted. Since the light reflected from the second bank layer BK2 is emitted laterally, the viewing angle of the finally emitted light may be widened.

Accordingly, in the present invention, the viewing angle can be further narrowed by using a material having low transmittance and low reflectance so as to absorb light in the first bank layer of the first subpixel, and the second bank layer of the second subpixel SP2 is By using a material having a higher reflectance than the first bank layer, there is an advantage in that the viewing angle can be further widened.

The organic light emitting display device of the present invention is to solve a problem that is difficult to apply in a mobile device capable of etching or rotating a conventional substrate, and can realize the following effects.

First, according to the present invention, one pixel is divided into two sub-pixels and the height of the bank layer is formed to be different, so that the first sub-pixel having a narrow viewing angle and the second sub-pixel having a wide viewing angle can be provided. Accordingly, the narrow viewing angle mode and the wide viewing angle mode may be selectively driven by emitting only the first sub-pixel or both the first and second sub-pixels.

Second, the present invention has an advantage in that a short circuit of the second electrode that may occur at the edge of the first bank layer can be covered by further forming an auxiliary electrode on the second electrode.

Third, according to the present invention, the viewing angle due to the micro-cavity effect can be further narrowed by providing the second electrode in the first sub-pixel, and the viewing angle can be further widened by including the transparent auxiliary electrode in the second sub-pixel without the second electrode There is this.

Fourth, according to the present invention, the viewing angle can be further narrowed by using a material having low transmittance and low reflectance so as to absorb light in the first bank layer of the first subpixel, and the second bank layer of the second subpixel SP2 is By using a material having a higher reflectance than the first bank layer, there is an advantage in that the viewing angle can be further widened.

Accordingly, the present invention has advantages in that there is no need to etch the substrate, thereby reducing manufacturing cost and realizing a wide viewing angle even when the display device is rotated by having sub-pixels capable of realizing a wide viewing angle.

Those skilled in the art from the above description will be able to see that various changes and modifications can be made without departing from the technical spirit of the present invention. Accordingly, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

SP1: first sub-pixel SP2: second sub-pixel
MSP: pixel BK1: first bank layer
BK2: second bank layer CAT: second electrode
AE: auxiliary electrode

Claims (12)

a first sub-pixel including a first light emitting unit and partitioned by a first bank layer; and
A plurality of pixels each including; a second sub-pixel including a second light emitting unit and partitioned by the first bank layer and a second bank layer having a height different from that of the first bank layer,
The first light emitting part of the first subpixel and the second light emitting part of the second subpixel have different areas and emit the same color. According to claim 1,
An area of the first light emitting part is smaller than an area of the second light emitting part. 3. The method of claim 2,
A height of the first bank layer is higher than a height of the second bank layer. 4. The method of claim 3,
each of the first sub-pixel and the second sub-pixel;
a first electrode;
an organic layer disposed on the first electrode and including at least a light emitting layer; and
and a second electrode disposed on the organic layer. 5. The method of claim 4,
The first electrode is an anode and the second electrode is a cathode. 5. The method of claim 4,
The first electrode is a reflective electrode and the second electrode is a transflective electrode. 7. The method of claim 6,
The display device further comprising an auxiliary electrode positioned on the second electrode. 4. The method of claim 3,
the first subpixel and the second subpixel include a first electrode and an organic film layer disposed on the first electrode, respectively, and including at least a light emitting layer;
the first sub-pixel includes a second electrode disposed on the organic layer;
a second electrode of the first subpixel and an auxiliary electrode disposed on the organic layer of the second subpixel;
The auxiliary electrode is a transparent electrode. 9. The method of claim 8,
The second electrode covers the first light emitting part but does not cover the second light emitting part. According to claim 1,
The first bank layer is made of a material having a lower reflectance than that of the second bank layer. a first sub-pixel including a first light emitting unit and partitioned by a first bank layer; and a second subpixel including a second light emitting part and partitioned by the first bank layer and a second bank layer having a height different from that of the first bank layer; In the display device of the first light emitting part of the subpixel and the second light emitting part of the second subpixel having different areas and emitting the same color,
In the narrow viewing angle mode, only the first subpixel of the plurality of pixels is driven to emit light, and in the wide viewing angle mode, the first subpixel and the second subpixel of the plurality of pixels are driven together to emit light as one pixel. A method of driving a display device. 12. The method of claim 11,
A method of driving a display device in which the second sub-pixels of the plurality of pixels are not driven in the narrow viewing angle mode.

Images