KR20170070439A - Organic light emitting device - Google Patents

Abstract

The organic light emitting device according to the present invention includes an organic light emitting diode including a first electrode and a second electrode, an organic layer disposed between the first electrode and the second electrode, a driving transistor for driving the organic light emitting diode, And a bank layer comprising a first opening defining a sensing transistor and a light emitting region and a second opening positioned corresponding to the sensing transistor.

Description

ORGANIC LIGHT EMITTING DEVICE

These embodiments relate to an organic light emitting device.

2. Description of the Related Art In the field of flat panel display devices, a liquid crystal display device which has been light and consumes less power has been widely used. However, since a liquid crystal display device is a non-emissive device which can not generate light itself, ratio, a viewing angle, and a large area.

Accordingly, a new flat panel display device capable of overcoming the disadvantages of such a liquid crystal display device has actively been developed. One of the new flat panel display devices is a light emitting device that generates light by itself, It has excellent brightness, viewing angle and contrast ratio as compared with the device, and since it does not need a backlight, it is possible to make a lightweight thin type, and is also advantageous in terms of power consumption.

The organic light emitting diode displays an image using light emitted from an organic light emitting diode connected to the thin film transistor of each pixel region. The characteristic value of the thin film transistor is not uniform or varies with time, and the characteristic value of the thin film transistor is sensed, and the accurate value is transmitted to the circuit part and compensated.

However, the OLED display senses characteristic values of the thin film transistor for various reasons and fails to transmit the accurate value to the circuit part, resulting in defects such as uneven brightness and unevenness.

It is an object of the embodiments of the present invention to provide an organic light emitting element which transmits an accurate value of a characteristic value of a driving transistor DTR to a circuit portion to prevent defects such as luminance unevenness and unevenness.

In order to solve the above problems, an organic light emitting diode according to an embodiment includes an organic light emitting diode including a first electrode and a second electrode, an organic layer disposed between the first electrode and the second electrode, A sensing transistor for sensing characteristics of the driving transistor and the driving transistor, and a bank layer including a first opening defining a light emitting region and a second opening corresponding to the sensing transistor.

In another aspect, in another embodiment, an organic light emitting element includes a thin film transistor disposed on a substrate, an insulating film disposed on the thin film transistor, a first electrode positioned on the insulating film, a portion of the first electrode exposed, And a second electrode located on the organic layer, and a second electrode located on the organic layer.

The present embodiments have an effect that it is possible to prevent defects such as luminance unevenness and unevenness by transmitting an accurate value of the characteristic value of the driving transistor DTR to the circuit portion.

1 is a system configuration diagram of an organic light emitting display device to which embodiments are applied.
2 is a circuit diagram of an organic light emitting device according to an embodiment.
3 is a circuit diagram of an organic light emitting device according to another embodiment.
4 is a circuit diagram further comprising a light-shielding layer in the organic light-emitting device of FIG.
5 is a cross-sectional view of an organic light emitting device according to another embodiment.
6 shows an optical path of light emitted from the organic layer of the organic light emitting device of FIG.
7 is a cross-sectional view of another example of the organic light emitting device of FIG.
8 is a sectional view of still another example of the organic light emitting device of FIG.
FIGS. 9 to 12 are plan views illustrating the positional relationship of the semiconductor layer, the gate electrode, and the second opening of the thin film transistor included in the organic light emitting element of FIG.
Figs. 13 and 14 are plan layouts of other examples of the light-shielding layer shown in Fig. 8 in the organic light-emitting display device in which the four sub-pixels constitute one pixel.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected," "coupled," or "connected." In the same context, when an element is described as being formed on an "upper" or "lower" side of another element, the element may be formed either directly or indirectly through another element As will be understood by those skilled in the art.

1 is a system configuration diagram of an organic light emitting display device to which embodiments are applied.

1, the OLED display 100 includes a timing controller 110, a data driver 120, a gate driver 130, and an organic light emitting diode (OLED) display panel 140.

The timing controller 110 controls the data driver 120 to control the data driver 120 based on vertical and horizontal synchronization signals Vsync and Hsync input from the host system and external timing signals such as video data and a clock signal CLK. And outputs a gate control signal (GCS) for controlling the data control signal (DCS) and the gate driver 130. The timing controller 110 may convert the video data input from the host system to a data signal format used by the data driver 120 and supply the converted video data 'data' to the data driver 120 have.

In response to the data control signal DCS and the converted video data 'data' input from the timing controller 110, the data driver 120 converts the video data 'data' into a data signal Analog pixel signals or data voltages) and supplies them to the data lines D1 to Dm.

The gate driver 130 sequentially supplies a scan signal (a gate pulse, a scan pulse, and a gate-on signal) to the gate lines G1 to Gn in response to a gate control signal GCS input from the timing controller 110. [

The organic light emitting diode display panel 140 may include two or more pixels formed in a pixel area (PA) defined by the data lines D1 to Dm and the gate lines G1 to Gn, And may include an organic light emitting device.

In each organic light emitting element P, driving voltage lines for supplying gate lines G1 to Gn, data lines D1 to Dm, and driving voltage or high potential voltage EVDD are arranged in each pixel region PA have. In addition, each organic light emitting device P includes an organic light emitting diode (OLED) including a first electrode, a second electrode, and an organic layer positioned between the first electrode and the second electrode, and an organic light emitting diode A driving transistor (DT) for supplying current, and a sensing transistor (ST) for sensing the characteristic value of the driving transistor.

Hereinafter, the circuit configuration of each organic light emitting element P will be described in more detail with reference to the drawings.

2 is a circuit diagram of an organic light emitting device according to an embodiment.

Referring to FIG. 2, in the organic light emitting diode display 100 according to the present embodiment, the organic light emitting diode 200 according to one embodiment includes an organic light emitting diode (OLED) A driving transistor (DTR) driving a diode OLED, and a sensing transistor STR (Sensing Transistor).

The organic light emitting diode OLED may include a first electrode (e.g., an anode electrode), an organic layer, and a second electrode (e.g., a cathode electrode). The organic light emitting diode OLED is located between the driving transistor DTR and the ground voltage EVSS.

The driving transistor DRT drives the organic light emitting diode OLED by supplying a driving current to the organic light emitting diode OLED.

The first node N1 of the driving transistor DRT may be electrically connected to the first electrode of the organic light emitting diode OLED and may be a source node or a drain node. The second node N2 of the driving transistor DRT may be electrically connected to the source node or the drain node of the switching transistor SWT and may be a gate node. The third node N3 of the driving transistor DRT may be electrically connected to a driving voltage line DVL for supplying a driving voltage EVDD and may be a drain node or a source node.

In the case of the OLED display 100 according to the present embodiment, as the driving time of the organic light emitting diode 200 is extended, the driving current of the organic light emitting diode OLED, the driving transistor DRT, Degradation can proceed. Accordingly, inherent characteristic values (e.g., threshold voltage, mobility, etc.) of the circuit elements such as the organic light emitting diode OLED and the driving transistor DRT can be changed. Such a change in the characteristic value of the circuit element causes a change in luminance of the organic light emitting diode OLED.

The sensing transistor STR can sense unique characteristic values (e.g., threshold voltage, mobility) of circuit elements such as the organic light emitting diode OLED and the driving transistor DRT. The sensing transistor STR is connected to the first node N1 of the driving transistor DTR and the other one of the source node or the drain node is connected to the sensing line RVL. Is connected to the node N4, and the gate node is connected to the gate line GL in a kind. In other words, the sensing transistor STR is positioned between the sensing line and one of the source node or the drain node of the driving transistor.

The organic light emitting diode 200 according to an exemplary embodiment includes a switching transistor SWT for transmitting a data voltage to a second node N2 corresponding to a gate node of the driving transistor DRT, And a storage capacitor (Cstg) for maintaining the data voltage corresponding to the data voltage or the voltage corresponding thereto for one frame time.

The organic light emitting device 200 according to one embodiment includes a bank layer 210 defining a light emitting region. The bank layer 210 is located between the first electrode of the organic light emitting diode OLED and the organic layer and exposes a part of the first electrode to form a first opening 212 defining a light emitting area (LEA) And a second opening 214 corresponding to the transistor STR.

The bank layer 210 may be a black bank having a black-based color. For example, the bank layer 210 may include at least one selected from an organic insulating material such as black resin, graphite powder, gravure ink, black spray, and black enamel, but is not limited thereto. Since the black bank is applied to the bank layer 210, defects in the light leakage can be solved.

In the organic light emitting diode 200, the bank layer 210 exposes the first electrode to the light emitting region through the first opening 212 and covers all the remaining regions. The first electrode, the organic layer, and the second electrode are positioned in the light emitting region defined by the first opening 212 to emit light. Accordingly, since there is no other insulating film between the first electrode and the second electrode so that the organic light emitting diode OLED including the first electrode, the organic layer, and the second electrode can act as a diode, only the first electrode of the bank layer 210 It is sufficient to open only the opening 212.

When the bank layer 210 applies a transparent bank without applying a black-based black bank, the upper portion of the sensing transistor STR is exposed to light, thereby canceling the PBTS applied to sense the characteristic value of the driving transistor DTR. However, when the above-described black bank is applied to the bank layer 210 in order to solve the problem of the light leakage, all the light is blocked, so that the positive shift of the sensing transistor STR becomes large and the characteristic value of the driving transistor DTR Voltage, mobility) may not be able to deliver accurate values when sensing.

In other words, in the OLED external compensation structure that senses the characteristic value of the driving transistor through the sensing transistor STR and reflects the sensed characteristic value, the sensing transistor STR is periodically turned on as a gate signal A gate high voltage (e.g., 24V) is applied for a long time to receive a strong PBTS. Since the black bank applied to the bank layer 210 blocks all the light that enters the upper portion of the sensing transistor STR, So that the degree of the positive shift of the threshold voltage of the sensing transistor STR is increased, thereby making it impossible to accurately transmit the characteristic value sensing value of the driving transistor.

However, in the organic light emitting diode 200 according to one embodiment, the light emitted from the organic layer, which is located between the first electrode and the organic layer and is located in the first opening 212, And reaches the sensing transistor STR through the transistor 214. In other words, the light emitted from the organic layer of the organic light emitting diode is reflected by the second electrode and reaches the sensing transistor STR through the second opening 214. The light emitted from the organic light emitting diode 200 may reach the sensing transistor STR but the light emitted from the adjacent organic light emitting diode may reach the corresponding sensing transistor STR. This will be described later with reference to FIG.

The driving transistor DTR and the sensing transistor STR may be implemented as an n-type as shown in FIG. 2 or a p-type as shown in FIG.

3 is a circuit diagram of an organic light emitting device according to another embodiment.

The organic light emitting diode 300 according to another embodiment includes an organic light emitting diode OLED, a driving transistor DTR for driving the organic light emitting diode OLED, and a sensing transistor STR.

The first node N1 of the driving transistor DRT is connected to the ground voltage EVSS. The second node N2 of the driving transistor DRT may be electrically connected to the source node or the drain node of the switching transistor SWT and may be a gate node. The third node N3 of the driving transistor DRT may be connected to the organic light emitting diode OLED.

The sensing transistor STR is connected to the third node N3 of the driving transistor DTR and one of the source node or the drain node is connected to the sensing line RVL. Is connected to the node N4, and the gate node is connected to the gate line GL in a kind.

In other words, in the organic light emitting diode 300 according to another embodiment, the organic light emitting diode OLED and the driving transistor DTR are connected in series between the driving voltage EVDD and the ground voltage EVSS, And the third node N3 between the driving transistor DTR and the sensing transistor STR.

The organic light emitting device 300 according to another embodiment may include a first opening 312 located between the first electrode of the organic light emitting diode OLED and the organic layer and exposing a portion of the first electrode to define the light emitting region LEA And a second opening 314 corresponding to the sensing transistor STR.

The organic light emitting devices 200 and 300 according to the embodiments described above are arranged such that the second openings 214 and 314 are disposed at positions corresponding to the sensing transistor STR so that the upper portion of the sensing transistor STR is electrically connected to the second opening 214 , 314) to receive the NBTS more strongly. Accordingly, the degree of positive shift of the threshold voltage of the sensing transistor STR can be relaxed

When the threshold voltage of the sensing transistor STR is positively shifted from the initial value, an accurate value of the characteristic value (e.g., threshold voltage, mobility) of the driving transistor DTR is supplied to the timing controller 110, It can not be transmitted to the circuit portion such as the light emitting diode 120, resulting in unevenness in brightness and unevenness. Since the organic light emitting diode 300 according to another embodiment of the present invention disposes the second opening 314 in the bank layer 310, it prevents the positive shift of the sensing transistor STR and prevents such defects such as luminance unevenness and unevenness can do.

4 is a circuit diagram further comprising a light-shielding layer in the organic light-emitting device of FIG.

4, the organic light emitting diode 300 according to another embodiment includes a driving transistor DTR and a sensing transistor STR on the opposite sides of the bank layer 310 as a driving transistor and a sensing transistor A light shielding layer 320 may be additionally provided at a position where the light shielding layer 320 is formed. As described above, since the light shielding layer 320 is disposed at a position corresponding to the sensing transistor STR, light from the outside is prevented from reaching the sensing transistor STR.

A gate high voltage (for example, 24 V) is applied to the sensing transistor STR for a long period of time to receive a strong positive bias temperature stress (PBTS) for sensing the characteristic value of the driving transistor periodically. The second openings 214 and 314 are disposed at corresponding positions to expose the upper portion of the sensing transistor STR to the light through the second openings 214 and 314 to receive a stronger negative bias temperature stress (NBTS). Accordingly, the degree of positive shift of the threshold voltage of the sensing transistor STR is relaxed and a more accurate value of the characteristic value (e.g., threshold voltage, mobility) of the driving transistor DTR is supplied to the timing controller 110 and the data driver 120, thereby preventing such defects as unevenness in luminance and unevenness.

2 to 4, the organic light emitting device according to the embodiments has been described in terms of a circuit. Hereinafter, the organic light emitting diode according to the embodiments will be described with reference to FIGS. 5 to 9. FIG.

5 is a cross-sectional view of an organic light emitting device according to another embodiment.

5, an organic light emitting diode 500 according to another embodiment includes a thin film transistor 520, an insulating layer 530 disposed on the thin film transistor 520, an insulating layer 530 A bank layer 550 located on the first electrode 540 and an organic layer 560 located on the first electrode 540 and an organic layer 560 located on the first electrode 540. The first electrode 540, 560). ≪ / RTI >

The substrate 510 may be a glass substrate, a plastic substrate including PET (polyethylene terephthalate), PEN (polyethylenenaphthalate), polyimide, or the like. In addition, a buffer layer may be further provided on the substrate 510 to block penetration of impurity elements. The buffer layer may be formed of a single layer or multiple layers of, for example, silicon nitride or silicon oxide.

The thin film transistor 520 may be formed of one of amorphous silicon, polysilicon, and metal oxide. The thin film transistor 520 may include, for example, a metal oxide such as IGZO (Indium Gallium Zinc Oxide), IGO (Indium Gallium Oxide), IZO (Indium Zinc Oxide), IZO (Indium Zinc Oxide), ZTO (Zinc Tin Oxide) , IHZO (Indium Hafnium Zinc Oxide), and IZZO (In Zirconium Zinc Oxide).

The thin film transistor 520 includes a semiconductor layer 522, a gate insulating film 523 formed on the semiconductor layer 522, a gate electrode 524 formed on the gate insulating film 523, A source electrode / drain electrode 526 formed on the insulating film 525 and the interlayer insulating film 525 and connected to the semiconductor layer 522 through the contact hole.

2 to 4, the thin film transistor 520 is connected to one of a source node or a drain node of a drive transistor DTR that supplies a current to the organic layer 560 to sense a characteristic value of the drive transistor Sensing transistor (STR), but is not limited thereto.

The organic light emitting device 500 may include an insulating layer 530 formed on the thin film transistor 520. The insulating film 530 may be a single layer or multiple layers. The insulating film 530 may be a planarizing film or an overcoat layer.

The insulating layer 530 may be formed of an inorganic insulating material, a benzocyclobutene (BCB), or an acryl based resin including any one of SiOx, SiNx, SiON, Al2O3, TiO2, Ta2O5, HfO2, ZrO2, BST, , Or a combination thereof. ≪ RTI ID = 0.0 >

The first electrode 540 may be an anode electrode (anode), and may have a relatively large work function value and may include a transparent conductive material such as a metal oxide such as indium tin oxide (ITO) or indium zinc oxide (IZO) : Mixtures of metals and oxides such as Al or SnO2: Sb, poly (3-methylthiophene), poly [3,4- (ethylene-1,2-dioxy) thiophene (PEDT), polypyrrole and polyaniline The same conductive polymer or the like. The pixel electrode 272 may be a carbon nanotube (CNT), a graphene, a silver nano wire, or the like.

On the other hand, the bank layer 550 has a matrix-like lattice structure as a whole on the substrate 510, and surrounds the edges of the first electrode 540 and exposes a part of the first electrode 540.

The bank layer 550 may be a black bank. The bank layer 550 may be formed of at least one selected from an organic insulating material such as black resin, graphite powder, gravure ink, black spray, and black enamel, but is not limited thereto.

The bank layer 550 includes a first opening portion 552 that exposes a portion of the first electrode 540 and defines a light emitting region and a second opening portion 552 that corresponds to a portion of the semiconductor layer 522 of the thin film transistor 520. [ (554).

The first opening 552 is bent at a predetermined angle from the bottom surface 552a contacting the insulating layer 530 in consideration of the step coverage of the organic layer 560 and the second electrode 570 located on the bank layer 550, . In other words, the first opening 552 is opened in an inverted tapered shape having a larger area of the top surface 552b than the bottom surface 552a in contact with the insulating film 530. Similarly, the second opening 554 is also opened in an inverted tapered shape having a larger area of the top surface 554b than the bottom surface 554a contacting the insulating film 530. [ The first opening portion 552 and the second opening portion 554 are simultaneously formed through the photolithography process with the mask in the state where the material of the bank layer 550 is coated on the process side, The side inclination of the two openings 554 may be the same, but is not limited thereto.

The organic layer 560 may include a hole injecting layer, a hole transporting layer, a light emitting layer, a light emitting auxiliary layer, an electron transporting layer, and an electron injecting layer. The organic layer 560 of FIG. 5 is applied to the entire surface without patterning. By omitting the patterning process, the effect of simplifying the process is obtained

A second electrode 570 is disposed on the organic layer 560. The second electrode 570 may be a cathode (negative electrode), and may have a relatively low work function value. For example, in the case of the bottom emission type, the second electrode 570 may be a metal and may be a single layer of an alloy composed of a first metal, for example, Ag, and a second metal, Or may be a plurality of layers.

6 shows an optical path of light emitted from the organic layer of the organic light emitting device of FIG.

In the organic light emitting device 500 according to another embodiment of the present invention, the bank layer 550 is formed between the first electrode 540 and the organic layer 560, and the light emitted from the organic layer 560 located in the first opening 552 And reaches the thin film transistor 520 through the second opening 554. In other words, light emitted from the organic layer 560 is reflected by the second electrode 570 and reaches the thin film transistor 520 through the second opening 554. The light emitted from the organic light emitting device 500 may reach the thin film transistor 520 but the light emitted from the adjacent organic light emitting device may reach the corresponding thin film transistor 520.

In this case, the degree of positive shift of the threshold voltage of the thin film transistor 520 is reduced, and when the thin film transistor 520 is a sensing transistor STR sensing the characteristic value of the driving transistor DTR shown in FIGS. 2 to 4 The thin film transistor 520 transmits a more accurate value of the characteristic value (for example, threshold voltage and mobility) of the driving transistor DTR to the circuit unit such as the timing controller 110 and the data driving unit 120 through the sensing line SL It is possible to prevent such defects such as luminance unevenness and unevenness.

The organic light emitting device 500 shown in FIG. 5 may be a white organic light emitting device in which the organic layer 560 emits white light. For this, the organic layer 560 and the second electrode 570 may be disposed on the front surface of the substrate 510. The organic layer 560 of the organic light emitting device 500 has a process advantage that can be applied to the entire surface in one step. The organic light emitting device 500 may include a color filter layer 580 on the top or bottom of the first electrode 540 at a position corresponding to the first opening 552 of the bank layer 550.

The color filter layer 580 of the organic light emitting diode 500 may have any one of red, blue, and green colors. In addition, in the case of the organic light emitting device 500 in which white is realized, the color filter layer 580 may not be formed. The arrangement of red, blue, and green may be variously formed, and a black matrix (not shown) made of a material capable of absorbing external light may be provided between each color filter layer 580.

7 is a cross-sectional view of another example of the organic light emitting device of FIG.

When the organic light emitting device 500 is a bottom emission type, the color filter layer 580 may be positioned below the first electrode 540 as shown in FIG. The light generated in the organic layer 560 is reflected by the second electrode 570 and passes through the color filter layer 580 to the outside of the organic light emitting element 500.

Although the organic light emitting device 500 is shown as a bottom emission type in which the light emitting direction is the direction from the first electrode 540 to the substrate 510, the present invention is not limited thereto, Of course. In the case of the upper light emitting organic light emitting device 500, the color filter layer 580 may be located above the first electrode 540.

8 is a sectional view of still another example of the organic light emitting device of FIG.

8, a light shielding layer 590 formed to correspond to the thin film transistor 520 may be formed between the substrate 510 and the thin film transistor 520. Referring to FIG. A buffer layer 592 may be disposed between the substrate 510 and the light shielding layer 590.

The light-shielding layer 590 protects the semiconductor layer 522 from external light and functions to prevent external light from being reflected to reduce visibility, brightness, and contrast ratio characteristics. Here, the external light introduced through the substrate 510 may be unpolarized.

As described above, the thin film transistor 520 of the organic light emitting diode 500 according to another embodiment may be an oxide transistor in which the semiconductor layer 522 is made of a metal oxide, A light shielding layer 590 may be formed in a region corresponding to the layer 522. [ This is because, in the case of an oxide transistor, the electrical characteristic or the chemical characteristic may be changed when external light is introduced into the semiconductor layer 522.

On the other hand, the light shielding layer 590 may have a multi-layer structure. Specifically, the light shielding layer 590 may be composed of a conductive layer and one or more low reflection layers. The conductive layer may be made of any one of, for example, Al, Pt, Pd, Ag, Mg, Au, Ni, Nd, Ir, Cr, Li, Ca, Mo, Ti, W, But is not limited thereto. The one or more low reflection layers may be a material that absorbs external light introduced through the substrate 510, or may be coated with a light absorbing material.

FIGS. 9 to 12 are plan views illustrating the positional relationship between the semiconductor layer, the gate electrode, and the second opening of the thin film transistor included in the organic light emitting element of FIG.

5 and 9, the thin film transistor 520 included in the organic light emitting device 500 according to another embodiment includes a semiconductor layer 522 and a gate electrode 524 crossing the semiconductor layer 522 .

The gate electrode 524 may be formed integrally with the gate line GL as described with reference to FIG. That is, a region where the gate line GL crosses and crosses the semiconductor layer 522 can serve as the gate electrode 524. [ The gate electrode 524 may be patterned separately from the gate line GL to cross the semiconductor layer 522. [

As described above, the second opening 554 is opened in an inverted tapered shape having a larger area than the bottom surface 554a in the top surface 554b. The side surface of the second opening 554 is inclined at a predetermined angle. The planar shape of the second opening 554 may be a rectangular shape as shown in FIG. 9, but is not limited thereto. For example, the planar shape of the second opening 554 may be a circular shape or a different shape as shown in Fig.

The bottom surface 554a of the second opening 554 may surround an intersecting region where the semiconductor layer 552 and the gate electrode 554 of the thin film transistor 520 intersect. For example, the bottom surface 554a of the second opening 554 may surround only a part of the intersection region where the semiconductor layer 552 and the gate electrode 554 of the thin film transistor 520 intersect.

When the bottom surface 554a of the second opening 554 surrounds the intersection region where the semiconductor layer 552 and the gate electrode 554 of the thin film transistor 520 intersect, the semiconductor layer 552 of the thin film transistor 520 And the gate electrode 554 intersect with the bottom surface 554a of the second opening 554 may be substantially the same.

The bottom surface 554a of the second opening portion 554 and the semiconductor layer 552 of the transistor 520 may be formed in a rectangular shape when the bottom surface 554a of the second opening portion 554 is rectangular, The spacing L1 to L4 of the four sides of the crossing region where the gate electrode 554 and the gate electrode 554 intersect can be substantially the same. 10, when the bottom surface 554a of the second opening 554 is circular, the bottom surface 554a of the second opening 554 contacts the semiconductor layer 552 of the transistor 520 and the gate 554a of the second opening 554, The electrode 554 may contact four corners of the intersecting region.

Another example is that the bottom surface 554a of the second opening 554 may wrap or intersect four edges of the intersection region where the semiconductor layer 552 of the transistor 520 and the gate electrode 554 intersect, have.

When the bottom surface 554a of the second opening 554 is rectangular and the bottom surface 554a of the second opening 554 and the semiconductor layer 552 of the transistor 520 and the gate electrode 554 cross each other, The distances L1 to L4 of the four sides may be different from each other. For example, between the bottom surface 554a of the second opening 554 and the two opposite sides of the crossing region where the semiconductor layer 552 and the gate electrode 554 of the transistor 520 intersect, (L2> L1), or the intervals L3 and L3 of the other two sides may be different from each other as shown in FIG. 12 (L2> L1, L3 > L4).

The bottom surface 554a of the second opening 554 may have a large opening area in the direction of the first opening 552 with respect to a crossing region where the semiconductor layer 522 and the gate electrode 524 cross each other . The distance between the bottom surface 554a of the second opening 554 in the direction toward the first opening 552 and the intersection region where the semiconductor layer 552 and the gate electrode 554 of the transistor 520 cross The light emitted from the organic layer 560 located in the first opening 552 can reach the thin film transistor 520 through the second opening 554 more.

8 located between the thin film transistor 520 and the substrate 510 may correspond to the intersection region where the semiconductor layer 522 and the gate electrode 524 intersect with each other . At this time, the area of the light-shielding layer 590 is wider than the crossing area where the semiconductor layer 522 and the gate electrode 524 cross each other, so that the light-shielding layer 590 can cover the entire intersecting region.

Figs. 13 and 14 are plan layouts of other examples of the light-shielding layer shown in Fig. 8 in the organic light-emitting display device in which the four sub-pixels constitute one pixel.

13, the light shielding layer 590 includes two first and second patterns 591 and 592 for transmitting a driving voltage EVDD to adjacent sub-pixels on the substrate 510, A third pattern 593 connected to the pixels, and a fourth pattern 594 used as a plate of the storage capacitor of each sub-pixel.

When the thin film transistor 520 is a sensing transistor in the planar arrangement of the light shielding layer 590 shown in FIG. 13, the thin film transistor 520 is arranged in a space 595 between the third pattern 593 and the fourth pattern 594, .

Referring to FIG. 14, the fourth pattern 594 included in the light-shielding layer 590 is also patterned in the space 595 to shield the thin film transistor 520.

As described above, since the light shielding layer 320 is disposed at a position corresponding to the thin film transistor 520, the light incident from the outside is prevented from reaching the thin film transistor 520. A second opening 554 at a location corresponding to the thin film transistor 520 is disposed to expose the upper portion of the thin film transistor 520 to the light through the second opening 554 to receive the NBTS more strongly.

According to the above-described embodiments, the upper portion of the thin film transistor is exposed to the light emitted from the organic light emitting element through the opening disposed separately in the bank layer, thereby alleviating the positive shift of the threshold voltage of the thin film transistor, (E.g., threshold voltage, mobility) of the DTR signal to the circuit unit, thereby preventing such defects as luminance unevenness and unevenness.

Although the embodiments have been described with reference to the drawings, the present invention is not limited thereto.

It is to be understood that the terms "comprises", "comprising", or "having" as used in the foregoing description mean that the constituent element can be implanted unless specifically stated to the contrary, But should be construed as further including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

200: Organic light emitting device
210: bank layer
212: first opening
214: second opening
OLED: Organic Light Emitting Diode
DTR: driving transistor
STR: sensing transistor

Claims (13)

An organic light emitting diode including a first electrode and a second electrode, and an organic layer disposed between the first electrode and the second electrode;
A driving transistor for driving the organic light emitting diode;
A sensing transistor for sensing a characteristic value of the driving transistor; And
And a bank layer including a first opening portion defining a light emitting region and a second opening portion corresponding to the sensing transistor. The method according to claim 1,
Wherein the bank layer is a black bank. The method according to claim 1,
Wherein the bank layer comprises at least one selected from the group consisting of a black resin, an organic insulating material, a graphite powder, a gravure ink, a black spray, and a black enamel. The method according to claim 1,
Wherein the sensing transistor is located between a sensing line and one of a source node or a drain node of the driving transistor. The method according to claim 1,
Wherein the organic light emitting device further comprises a light shielding layer at a position corresponding to the driving transistor and the sensing transistor on the opposite side of the driving transistor and the sensing transistor with respect to the bank layer. A thin film transistor positioned on a substrate;
An insulating film disposed on the thin film transistor;
A first electrode located on the insulating film;
A bank layer including a first opening exposing a part of the first electrode to define a light emitting region and a second opening corresponding to the thin film transistor;
An organic layer disposed on the first electrode; And
And a second electrode located on the organic layer. The method according to claim 6,
Wherein the bank layer is a black bank. The method according to claim 6,
Wherein the bank layer comprises at least one selected from the group consisting of a black resin, an organic insulating material, a graphite powder, a gravure ink, a black spray, and a black enamel. The method according to claim 6,
The organic layer and the second electrode are disposed on the front surface of the substrate,
And a color filter layer on the upper or lower portion of the first electrode at a position corresponding to the first opening of the bank layer. The method according to claim 6,
Wherein the thin film transistor is a sensing transistor connected to one of a source node or a drain node of a driving transistor for supplying current to the organic layer and sensing a characteristic value of the driving transistor. The method according to claim 6,
Wherein the second opening is opened in an inverted tapered shape having a larger area of a top surface than a bottom surface in contact with the insulating film,
And a bottom surface of the second opening surrounds a crossing region where the semiconductor layer of the thin film transistor and the gate electrode cross each other. 12. The method of claim 11,
And the bottom surface of the second opening has a large opening area in the direction of the first opening with reference to a crossing region where the semiconductor layer and the gate electrode intersect. The method according to claim 6,
Further comprising a light shielding layer disposed between the thin film transistor and the substrate,
Wherein the light-shielding layer is located corresponding to a crossing region where the semiconductor layer and the gate electrode cross each other.

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