Patent Description:
Organic light-emitting display devices are self-emitting display devices that electrically excite organic compounds to emit light. Organic light-emitting display devices have drawn attention as next-generation display devices capable of resolving problems that have been pointed out in liquid crystal display devices because organic light-emitting display devices may be driven at lower voltages, may be more easily made thin, may have wider viewing angles, and may have faster response speeds when compared with liquid crystal display devices.

For certain purposes (e.g. where a transparent or transmissive display is required) it may be desirable to produce a transparent organic light-emitting display device by forming a light-transmitting portion in an area other than an area including a thin film transistor or an organic light-emitting device. This may require performing a patterning process so that a cathode formed using an opaque metal is not formed in the light-transmitting portion. However, forming an opening pattern in a cathode, which may be a common electrode, makes it difficult to use a fine metal mask such as often used in a conventional patterning process. In addition, when a common electrode cathode covers all the pixels, wiring resistance may be increased. <CIT>, <CIT>, <CIT> and <CIT> all provide disclosures related to display devices.

According to an aspect, there is provided an organic light emitting display device according to claim <NUM>. Details of embodiments are provided in the dependent claims. The present invention sets out to provide an organic light-emitting display device having simplified formation of an opening pattern of a common electrode, and decreased wiring resistance of the common electrode.

The above and other features and aspects of the present invention will become more apparent by referring to embodiments thereof which are described below with reference to the attached drawings in which:.

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

<FIG> is a schematic cross-sectional view of an organic light-emitting display device according to an embodiment of the present invention.

Referring to <FIG>, the organic light-emitting display device includes a substrate <NUM> and a display unit <NUM> formed on the substrate <NUM>. In the organic light-emitting display device, external light penetrates the substrate <NUM> and the display unit <NUM>. For example, external light enters one side of the organic light-emitting display device, transmits through the display unit <NUM> and the substrate <NUM>, and exits another side of the organic light-emitting display device. That is, the display unit <NUM> is formed to transmit external light (e.g., is transparent), as described in more detail below. As depicted in <FIG>, the display unit <NUM> is formed so that a user viewing an image displayed on the organic light-emitting display device may also view an external light transmission (for example, a scene behind the organic light-emitting display device) transmitted through the substrate <NUM> and the display unit <NUM>.

<FIG> shows a first pixel P1 and a second pixel P2 that are disposed adjacent to each other in the organic light-emitting display device. Each of the first and second pixels P1 and P2 includes a first region <NUM> and a second region <NUM>. An image is displayed by the display unit <NUM> through the first region <NUM> while external light penetrates (i.e., transmits through) the second region <NUM>. In other words, both the first and second pixels P1 and P2 include the first region <NUM> to display an image and the second region <NUM> through which external light penetrates and thus, a user may see an external scene (i.e., behind the organic light-emitting display device) through the second region <NUM> in addition to or in place of when the user sees the image displayed in the first region <NUM>.

In this regard, transmittance of the external light may be significantly increased by not forming devices such as a thin film transistor, a capacitor, or an organic light-emitting device in the second region <NUM>. That is, by forming devices such as thin film transistors, capacitors, and organic light-emitting devices in the first region <NUM> and not in the second region <NUM>, distortion or other degradation of the transmitted external light due to interference by such devices may be reduced or prevented as much as possible.

Although <FIG> shows a bottom emission-type light-emitting display device in which an image of the display unit <NUM> is displayed toward the substrate <NUM>, the present invention is not limited thereto. As shown in <FIG>, embodiments of the present invention may be used in a top emission-type light-emitting display device in which the image of the display unit <NUM> is displayed away from the substrate <NUM>. In addition, as shown in <FIG>, embodiments of the present invention may be used in a two-sided light-emitting display device in which the image of the display unit <NUM> is displayed both toward and away from the substrate <NUM>.

The above-described embodiments of the organic light-emitting display device may be embodied in further detail as shown in <FIG> and/or <FIG>.

Referring to <FIG>, the display unit <NUM> includes an organic light-emitting unit <NUM> formed on the substrate <NUM> and a sealing substrate <NUM> for sealing the organic light-emitting unit <NUM>. The sealing substrate <NUM> is formed of a transparent member to display an image from the organic light-emitting unit <NUM> and reduces or prevents external air and moisture from entering the organic light-emitting unit <NUM>. Edges of the substrate <NUM> and the sealing substrate <NUM> are coupled to each other via a sealing material <NUM> to seal a space <NUM> between the substrate <NUM> and the sealing substrate <NUM>. A moisture absorbent, a filling material, or the like may be located in the space <NUM>.

As shown in <FIG>, a sealing film <NUM> formed thin, instead of the sealing substrate <NUM>, may be formed on the organic light-emitting unit <NUM> to protect the organic light-emitting unit <NUM> against external air or moisture. The sealing film <NUM> may have a structure in which a film formed of an inorganic material, such as silicon oxide or silicon nitride, and a film formed of an organic material, such as epoxy or polyimide, are alternately formed, but the present invention is not limited thereto. That is, any transparent thin film having a sealing structure may be used as the sealing film <NUM>.

<FIG> is a plan view showing pixels P of an organic light-emitting display device according to an embodiment of the present invention. <FIG> is a cross-sectional view taken along line I-I of <FIG> according to an embodiment of the present invention. Each pixel P may include a red pixel Pr, a green pixel Pg, and a blue pixel Pb that are disposed adjacent to one another.

Each of the red pixel Pr, the green pixel Pg, and the blue pixel Pb includes a circuit region <NUM> and a light-emitting region <NUM> in the first region <NUM>. In the embodiment of <FIG>, the circuit region <NUM> and the light-emitting region <NUM> are disposed to overlap with each other. The light-emitting region <NUM> includes a first electrode <NUM> that may be disposed to overlap with the circuit region <NUM>.

The second region <NUM>, including a transmissive region for transmitting external light, is disposed adjacent to the first region <NUM>. Although the transmissive region corresponds to the second region <NUM> in <FIG>, the present invention is not limited thereto. In addition, in <FIG>, the second region <NUM> is formed wider than the first region <NUM> to include the transmissive region.

The second regions <NUM> may be independently formed in the red, green, and blue pixels Pr, Pg, and Pb or may be formed to be connected to one another across the red, green, and blue pixels Pr, Pg, and Pb. In other words, one pixel P includes the red pixel Pr, the green pixel Pg, and the blue pixel Pb. In this regard, one pixel P may include the second region <NUM> and thus, the second region <NUM> may be formed across the red pixel Pr, the green pixel Pg, and the blue pixel Pb. In this case, since an area of the second region <NUM> for transmitting external light may be extended, transmittance of the entire display unit <NUM> may be increased.

A second electrode <NUM> is disposed in the first region <NUM>. As with the second region <NUM>, one pixel P may include the second electrode <NUM> and thus, the second electrode may be formed across the red pixel Pr, the green pixel Pg, and the blue pixel Pb.

A third region <NUM> is located between the pixels P. A third electrode <NUM> is located in the third region <NUM>. At least one wiring line <NUM> may be located in the third region <NUM>, as shown in <FIG>. The wiring line <NUM> may be electrically connected to a pixel circuit unit to be described below.

Each circuit region <NUM> includes a pixel circuit unit including a thin film transistor TR, as shown in <FIG>. However, the present invention is not limited thereto, and the pixel circuit unit may further include a plurality of thin film transistors TR and one or a plurality of storage capacitors. The pixel circuit unit may further include a plurality of wiring lines, such as scan lines, data lines, and Vdd lines, connected to the thin film transistors TR and the storage capacitors.

Each light-emitting region <NUM> may include an organic light-emitting diode EL that is a luminous element. The organic light-emitting diode EL is electrically connected to the thin film transistor TR of the pixel circuit unit.

A buffer layer <NUM> is formed on the substrate <NUM>, and the pixel circuit unit, including the thin film transistor TR, is formed on the buffer layer <NUM>. A semiconductor active layer <NUM> is formed on the buffer layer <NUM>. The buffer layer <NUM> is formed of a transparent insulating material, and also may be formed of any of various other materials capable of reducing or preventing penetration of impurity substances and of planarizing a surface of the substrate <NUM>. For example, the buffer layer <NUM> may be formed of an inorganic material such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, titanium oxide, or titanium nitride, an organic material such as polyimide, polyester, or acryl, or a stack of inorganic and organic materials. In other embodiments, the buffer layer <NUM> may not be formed.

The semiconductor active layer <NUM> may be formed of polycrystalline silicon. However, the present invention is not limited thereto, and the semiconductor active layer <NUM> may be formed of an oxide semiconductor. For example, the semiconductor active layer <NUM> may be a G-I-Z-O layer [(In<NUM>O<NUM>)a(Ga<NUM>O<NUM>)b(ZnO)c layer] (a, b, and c are real numbers satisfying conditions a ≥ <NUM>, b ≥ <NUM>, and c > <NUM>, respectively). When the semiconductor active layer <NUM> is formed of an oxide semiconductor, light transmittance in the circuit region <NUM> of the first region <NUM> may further be increased and thus, transmittance of external light of the entire display unit <NUM> may be increased.

A gate insulating layer <NUM> is formed on the buffer layer <NUM> to cover the semiconductor active layer <NUM>. A gate electrode <NUM> is formed on the gate insulating layer <NUM>. An insulating interlayer <NUM> is formed on the gate insulating layer <NUM> to cover the gate electrode <NUM>. A source electrode <NUM> and a drain electrode <NUM> are formed on the insulating interlayer <NUM> to contact the semiconductor active layer <NUM> via contact holes. In other embodiments, the structure of the thin film transistor TR is not limited thereto, and a thin film transistor TR having any of various other structures may be used.

A first insulating layer <NUM> is formed to cover the thin film transistor TR. The first insulating layer <NUM> may be an insulating layer having a single-layered or multi-layered structure with a planarized top surface. The first insulating layer <NUM> may be formed of an inorganic material and/or an organic material.

The first electrode <NUM> of the organic light-emitting diode EL is electrically connected to the thin film transistor TR and is formed on the first insulating layer <NUM>, as shown in <FIG>. The first electrode <NUM> is formed into an island shape that is independently formed in each pixel.

A second insulating layer <NUM> is formed on the first insulating layer <NUM> to cover an edge of the first electrode <NUM>. An opening 219a is formed in the second insulating layer <NUM> to expose a center portion, other than the edge, of the first electrode <NUM>. The second insulating layer <NUM> may be formed of an organic material such as acryl or polyimide.

An EL layer <NUM> is formed on the first electrode <NUM> exposed by the opening 219a. The second electrode <NUM> is formed to cover the EL layer <NUM>, thereby completing the formation of the organic light-emitting diode EL. The EL layer <NUM> may be a low-molecular organic layer or a polymer organic layer. When the EL layer <NUM> is a low-molecular organic layer, a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) may be stacked as a multi-layered structure. These low-molecular organic layers may be formed by using a vacuum evaporation method.

The EML is formed in each of the red, green, and blue pixels. The other layers, for example, the HIL, the HTL, the ETL, the EIL, etc., are common layers and may be commonly used and/or formed in the red, green, and blue pixels. Although the EL layer <NUM> is patterned to be located only in the first region <NUM> in <FIG>, the present invention is not limited thereto. In addition, although not shown in the drawing, the common layers such as the HIL, the HTL, the ETL, and the EIL may be located in the second region <NUM> and/or the third region <NUM>, and this may also be applied to all subsequently described embodiments.

The HIL may be formed of phthalocyanine compounds such as copper phthalocyanine (CuPc), or TCTA, <NUM>,<NUM>,<NUM>-tris(<NUM>-methylphenylphenylamino)triphenylamine (m-MTDATA), or m-MTDAPB, which is a starburst amine-based material. The HTL may be formed of, for example, <NUM>,<NUM>'-Bis[N-(<NUM>-methylphenyl)-N-phenylamino]biphenyl (TPD), N,N'-bis(<NUM>-naphthyl)-N,N'-diphenyl[<NUM>,<NUM>'-biphenyl]-<NUM>,<NUM>'-diamine (α-NPD), or the like. The EIL may be formed of, for example, LiF, NaCl, CsF, Li<NUM>O, BaO, Liq, or the like. The ETL may be formed of, for example, Alq3.

The EML may include a host material and a dopant material. Examples of the host material may include tris(<NUM>-hydroxy-quinolinato)aluminum (Alq3), <NUM>,<NUM>-di(naphth-<NUM>-yl)anthracene (AND), <NUM>-tert-butyl-<NUM>,<NUM>-di(naphth-<NUM>-yl)anthracene (TBADN), <NUM>,<NUM>'-bis(<NUM>,<NUM>-diphenyl-ethene-<NUM>-yl)-<NUM>,<NUM>'-dimethylphenyl (DPVBi), <NUM>,<NUM>'-bis(<NUM>,<NUM>-di(<NUM>-methyphenyl-ethene-<NUM>-yl)-biphenyl (p-DMDPVBi), etc. Examples of the dopant material may include <NUM>,<NUM>'-bis[<NUM>-(di-p-tolylamino)styryl]biphenyl (DPAVBi), <NUM>,<NUM>-di(naph-<NUM>-tyl)anthracene (ADN), <NUM>-tert-butyl-<NUM>,<NUM>-di(naph-<NUM>-tyl)anthracene (TBADN), etc..

The first electrode <NUM> may serve as an anode and the second electrode <NUM> may serve as a cathode, or vice-versa. When the first electrode <NUM> serves as an anode, the first electrode <NUM> may be formed of a high-work function material, for example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), In<NUM>O<NUM>, etc. In <FIG>, if the organic light-emitting display device is a top emission-type light-emitting display device in which an image is displayed away from the substrate <NUM>, the first electrode <NUM> may further include a reflection layer (not shown) formed of silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), ytterbium (Yb), cobalt (Co), samarium (Sm), or calcium (Ca).

When the second electrode <NUM> serves as a cathode, the second electrode <NUM> may be formed of a metal such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Yb, Co, Sm, or Ca. In <FIG>, if the organic light-emitting display device is a bottom emission-type light-emitting display device in which an image is displayed toward the substrate <NUM>, the second electrode <NUM> may be formed of a material having light transmittance. For this, the second electrode <NUM> may be formed as a thin film using Mg and/or a Mg alloy. Unlike the first electrode <NUM>, the second electrode <NUM> may be formed as a common electrode to apply a common voltage to all the pixels P.

When the second electrode <NUM> is a common electrode that applies a common voltage to all the pixels P, a surface resistance of the second electrode <NUM> is increased and thus, a voltage drop may occur. To address this problem, the third electrode <NUM> may further be formed to be electrically connected to the second electrode <NUM>. The third electrode <NUM> may be formed of a metal such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Yb, Co, Sm, or Ca. In addition, the third electrode <NUM> may be formed of the same material used for forming the second electrode <NUM>.

According to the embodiment shown in <FIG>, a first auxiliary layer <NUM> is formed on the EL layer <NUM> and the second insulating layer <NUM> before forming the second electrode <NUM>. The first auxiliary layer <NUM> is formed only in the first region <NUM> and the third region <NUM> and not in the second region <NUM>, which is a region for transmitting light, by deposition using a mask (not shown).

The first auxiliary layer <NUM> may be formed of a material that may bond well to the metal for forming the second electrode <NUM> (in particular, Mg and/or a Mg alloy) formed on the first auxiliary layer <NUM>. For example, the first auxiliary layer <NUM> may include Alq3, di-tungsten tetra(hexahydropyrimidopyrimidine), fullerene, lithium fluoride (LiF), <NUM>,<NUM>-di <NUM>-naphthyl)anthracene (ADN), or <NUM>-hydroxyquinolinolato-lithium (Liq). The first auxiliary layer <NUM> is patterned to be formed only in the first region <NUM> and the third region <NUM> and not in the second region <NUM>, and then is formed on the EL layer <NUM> (in the first region <NUM>) and the second insulating layer <NUM> (in the third region <NUM>), and then the second electrode <NUM> is formed.

The second electrode <NUM> may be formed by commonly depositing a metal for forming the second electrode <NUM> on all the pixels P including the first to third regions <NUM> to <NUM> by using an open mask. In this regard, as described above, the second electrode <NUM> is formed into a thin film to be a semipermeable reflection film (e.g., a semi-transparent and semi-reflective film). As such, if the metal for forming the second electrode <NUM> is commonly deposited on all the pixels P by using an open mask, the metal for forming the second electrode <NUM> is deposited on the first auxiliary layer <NUM> (e.g., in the first and third regions <NUM> and <NUM>) and the second insulating layer <NUM> (e.g., in the second region <NUM>). Also, if the EL layer <NUM> includes a common layer, the metal for forming the second electrode <NUM> may be deposited on the common layer constituting the EL layer <NUM>, in particular, an EIL (not shown), instead of being deposited on the second insulating layer <NUM>.

In this regard, the second electrode <NUM> may be formed only on the first auxiliary layer <NUM> instead of being formed on the second insulating layer <NUM> exposed in the second region <NUM> and/or on the common layer constituting the EL layer <NUM>, as shown in <FIG>, by allowing the metal for forming the second electrode <NUM> to be deposited favorably on the first auxiliary layer <NUM> and to be deposited unfavorably on the second insulating layer <NUM> and/or the common layer. In other words, since adhesion of the second electrode <NUM> with respect to the first and third regions <NUM> and <NUM> is greater than adhesion of the second electrode <NUM> with respect to the second region <NUM>, and since the second electrode <NUM> is formed into a thin film, the second electrode <NUM> is formed only in the first region <NUM> and the third region <NUM> and not in the second region <NUM>.

Thus, the second electrode <NUM> may be easily patterned without using a separate mask for patterning. For this, the second insulating layer <NUM> and/or the common layer may be formed of a material having low adhesion with respect to the metal for forming the second electrode <NUM>, compared to that of the first auxiliary layer <NUM>. For example, the second insulating layer <NUM> may be formed of acryl, and the common layer, in particular, the EIL, may be formed of Liq. The second electrode <NUM> formed in the above-described way is located only in the first region <NUM> and the third region <NUM> and not in the second region <NUM>.

Next, a second auxiliary layer <NUM> is formed in the first region <NUM> and the second region <NUM>. The second auxiliary layer <NUM> is formed on the second electrode <NUM> in the first region <NUM> and is formed on the second insulating layer <NUM> in the second region <NUM> or on the common layer constituting the EL layer <NUM>. The second auxiliary layer <NUM> may be patterned not to be formed in the third region <NUM>.

The second auxiliary layer <NUM> may be formed of a material that may not bond well to the metal for forming the third electrode <NUM> (in particular, Mg and/or a Mg alloy) formed on the second electrode <NUM>. For example, the second auxiliary layer <NUM> may be formed of a material including N,N'-diphenyl-N,N'-bis(<NUM>-phenyl-<NUM>-carbazol-<NUM>-yl)biphenyl-<NUM>,<NUM>'-diamine, N(diphenyl-<NUM>-yl)<NUM>,<NUM>-dimethyl-N-(<NUM>(<NUM>-phenyl-<NUM>-carbazol-<NUM>-yl)phenyl)-<NUM>-fluorene-<NUM>-amine, <NUM>-(<NUM>-(<NUM>,<NUM>-di(naphthalene-<NUM>-yl)anthracene-<NUM>-yl)phenyl)-<NUM>-phenyl-<NUM>-benzo-[D]imidazole), m-MTDATA, α-NPD, or TPD.

The second auxiliary layer <NUM> serves as a mask when forming the third electrode <NUM>. In other words, when the metal for forming the third electrode <NUM> is commonly deposited on the first to third regions <NUM> to <NUM> by using an open mask after forming the second auxiliary layer <NUM>, the third electrode <NUM> may not be favorably deposited in the first region <NUM> and the second region <NUM> and may be formed only in the third region <NUM> because the second auxiliary layer <NUM> is formed in the first region <NUM> and the second region <NUM>. The third electrode <NUM> is formed thicker than the second electrode <NUM>, and thus, a voltage drop may be reduced or prevented from occurring in the second electrode <NUM> for applying a common voltage.

The above-described embodiment has process benefits because the second electrode <NUM> and the third electrode <NUM> formed of a metal may be patterned without using a separate mask. In addition, transmittance of an entire panel may be improved by not forming the second electrode <NUM> and the third electrode <NUM> in the second region <NUM> including a transmissive region.

<FIG> is a cross-sectional view taken along line I-I of <FIG> according to another embodiment of the present invention.

Even though the first auxiliary layer <NUM> is formed of a material that may bond well to the metal for forming the second electrode <NUM> (in particular, Mg and/or a Mg alloy) formed on the first auxiliary layer <NUM>, a small amount of metal may be deposited even in a region where the first auxiliary layer <NUM> is not formed. Thus, when the first auxiliary layer <NUM> is formed only in the first region <NUM> and the third region <NUM> and not in the second region <NUM>, if a metal for forming the second electrode <NUM> is deposited in the first region <NUM> to the third region <NUM> by using an open mask as in the embodiment shown in <FIG>, the second electrode <NUM> may be formed in the first region <NUM> to the third region <NUM> as shown in <FIG>. In this regard, a thickness t2 of a portion 222b of the second electrode <NUM> located in the second region <NUM> may be smaller than a thickness t1 of a portion 222a of the second electrode <NUM> located in the first region <NUM> and the third region <NUM>. For example, the thickness t2 of the second electrode <NUM> in the second region <NUM> may be less than the thickness t1 of the second electrode <NUM> in the first and third regions <NUM> and <NUM>.

In addition, even though the second auxiliary layer <NUM> is formed of a material that may not bond well to a metal for forming the third electrode <NUM> (in particular, Mg and/or a Mg alloy) formed on the second auxiliary layer <NUM>, a small amount of metal may be deposited on the second auxiliary layer <NUM>. Thus, when the second auxiliary layer <NUM> is formed only in the first region <NUM> and the second region <NUM> and not in the third region <NUM>, if a metal for forming the third electrode <NUM> is deposited in the first region <NUM> to the third region <NUM> by using an open mask as in the embodiment shown in <FIG>, the third electrode <NUM> may be formed in the first region <NUM> to the third region <NUM> as shown in <FIG>. In this regard, a thickness t4 of a portion 223b of the third electrode <NUM> located in the first region <NUM> and the second region <NUM> may be smaller (for example, much smaller) than a thickness t3 of a portion 223a of the third electrode <NUM> located in the third region <NUM>.

As such, in the embodiment shown in <FIG>, the portion 222b of the second electrode <NUM> formed of a metal and the portion 223b of the third electrode <NUM> are located in the second region <NUM>, which is a transmissive region. However, in this case, since the portion 222b of the second electrode <NUM> and the portion 223b of the third electrode <NUM> are formed relatively thin, transmittance of external light through the second region <NUM> may not be greatly decreased.

<FIG> is a cross-sectional view taken along line I-I of <FIG> according to another embodiment not forming part of the present invention but useful to understand it.

The embodiment shown in <FIG> is the same as that shown in <FIG> and/or <FIG> up to the process of forming of the EL layer <NUM>. At that point, the first auxiliary layer <NUM> is deposited on the EL layer <NUM> across the first region <NUM> to the third region <NUM>. Then, a third auxiliary layer <NUM> is formed on the first auxiliary layer <NUM>. In this regard, the third auxiliary layer <NUM> may be located only in the second region <NUM> by forming the third auxiliary layer <NUM> using a patterning mask.

The third auxiliary layer <NUM> may be formed of a material having the same characteristics as the second auxiliary layer <NUM>. In other words, the third auxiliary layer <NUM> may be formed of a material that may not bond well to the metal for forming the second electrode <NUM> (in particular, Mg and/or a Mg alloy) formed on the first auxiliary layer <NUM>.

The metal for forming the second electrode <NUM> is deposited across the first region <NUM> to the third region <NUM> by using an open mask after forming the third auxiliary layer <NUM>. Thus, the metal for forming the second electrode <NUM> is deposited on the first auxiliary layer <NUM> in the first region <NUM> and the third region <NUM> and is deposited on the third auxiliary layer <NUM> in the second region <NUM>. In this regard, since adhesion between the first auxiliary layer <NUM> and the metal for forming the second electrode <NUM> is favorable and adhesion between the third auxiliary layer <NUM> and the metal for forming the second electrode <NUM> is unfavorable, the second electrode <NUM> is formed only in the first region <NUM> and the third region <NUM> and not in the second region <NUM>.

Next, the second auxiliary layer <NUM> is formed on the second electrode <NUM> and the third auxiliary layer <NUM>. In this regard, the second auxiliary layer <NUM> may be formed only in the first region <NUM> and the second region <NUM> and not in the third region <NUM> by forming the second auxiliary layer <NUM> using a patterning mask.

Next, a metal for forming the third electrode <NUM> is deposited across the first region <NUM> to the third region <NUM> by using an open mask. Thus, the metal for forming the third electrode <NUM> is deposited on the second auxiliary layer <NUM> in the first region <NUM> and the second region <NUM> and on the second electrode <NUM> in the third region <NUM>. In this regard, since adhesion between the second auxiliary layer <NUM> and the metal for forming the third electrode <NUM> is unfavorable, the third electrode <NUM> is formed only in the third region <NUM> and not in the first region <NUM> and the second region <NUM>.

The above-described embodiment has process benefits because the second electrode <NUM> and the third electrode <NUM> formed of a metal may be patterned without using a separate mask, and transmittance of an entire panel may be improved by not forming the second electrode <NUM> and the third electrode <NUM> in the second region <NUM> including a transmissive region.

<FIG> is a cross-sectional view taken along line I-I of <FIG> according to another not forming part of the present invention but useful to understand it.

Similar to the second auxiliary layer <NUM>, even though the third auxiliary layer <NUM> is formed of a material that may not bond well to a metal, in particular, to Mg and/or a Mg alloy, a small amount of metal may be deposited on the third auxiliary layer <NUM>. Thus, when the third auxiliary layer <NUM> is formed only in the second region <NUM> and not in the first region <NUM> and the third region <NUM>, if a metal for forming the second electrode <NUM> is deposited in the first region <NUM> to the third region <NUM> by using an open mask as in the embodiment shown in <FIG>, the second electrode <NUM> may be formed in the first region <NUM> to the third region <NUM> as shown in <FIG>. In this regard, the thickness t2 of the portion 222b of the second electrode <NUM> located in the second region <NUM> may be smaller (for example, significantly smaller) than the thickness t1 of the portion 222a of the second electrode <NUM> located in the first region <NUM> and the third region <NUM>.

In addition, as described above, a small amount of metal may be deposited on the second auxiliary layer <NUM>. Thus, when the second auxiliary layer <NUM> is formed only in the first region <NUM> and the second region <NUM> and not in the third region <NUM>, if a metal for forming the third electrode <NUM> is deposited in the first region <NUM> to the third region <NUM> by using an open mask as in the embodiment shown in <FIG>, the third electrode <NUM> may be formed in the first region <NUM> to the third region <NUM> as shown in <FIG>. In this regard, the thickness t4 of the portion 223b of the third electrode <NUM> located in the first region <NUM> and the second region <NUM> may be smaller (for example, significantly smaller) than the thickness t3 of the portion 223a of the third electrode <NUM> located in the third region <NUM>.

In the embodiments shown in <FIG>, since the circuit region <NUM> overlaps with the light-emitting region <NUM>, the embodiments shown in <FIG> may be more appropriate for a top emission-type light-emitting display device in which an image is displayed away from the substrate <NUM>. In this case, since the circuit region <NUM> is covered by the light-emitting region <NUM>, a decrease in transmittance of external light due to the circuit region <NUM> may be suppressed, and also, a decrease in luminance efficiency of the light-emitting region <NUM> due to the circuit region <NUM> may be suppressed.

<FIG> is a plan view showing adjacent pixels of an organic light-emitting display device according to another embodiment of the present invention. In <FIG>, the circuit region <NUM> does not overlap with the light-emitting region <NUM> and the first electrode <NUM>. The organic light-emitting display device having a structure shown in <FIG> may be appropriate even when the organic light-emitting display device is a bottom emission-type light-emitting display device in which an image emitted from the light-emitting region <NUM> is displayed toward the substrate <NUM>.

In the organic light-emitting display device having a structure shown in <FIG>, the light-emitting region <NUM> is not influenced by the circuit region <NUM> and thus, luminance efficiency of the light-emitting region <NUM> may be prevented from being decreased (or any such decreasing can be reduced). However, although not shown in <FIG>, the circuit region <NUM> of the first region <NUM> may at least partially overlap with the third region <NUM> in the embodiment shown in <FIG>. Thus, the third electrode <NUM> formed in the third region <NUM> may overlap with the circuit region <NUM>. An area of the second auxiliary layer <NUM> (see <FIG>) serving as a mask for forming the third electrode <NUM> may be adjusted to correspond to an area where the third electrode <NUM> is formed.

In the above-described embodiments, the light-emitting display device is patterned in such a way that only the second electrode <NUM> has an opening in the second region <NUM>, but the present invention is not limited thereto. The light-emitting display device may be patterned in such a way that at least a part of at least one insulating layer from among insulating layers located in the second region <NUM> has an opening, and thus, transmittance of external light in the second region <NUM> may further be increased.

Claim 1:
An organic light-emitting display device comprising:
a plurality of pixels each comprising:
a first region (<NUM>) comprising a light-emitting region for emitting light, a first electrode (<NUM>) and an emission layer (<NUM>) covering the first electrode (<NUM>) being located in the light-emitting region; and
a second region (<NUM>) adjacent to the first region in a plan view and comprising a transmissive region for transmitting external light through the display device;
a third region (<NUM>) between the pixels;
a first auxiliary layer (<NUM>) located in the first region on the emission layer (<NUM>) and in the third region, the first auxiliary layer being not located in the second region;
a second electrode (<NUM>) formed from a metal on the first auxiliary layer (<NUM>) in the first and third regions, wherein the first auxiliary layer (<NUM>) comprises a first material;
a second auxiliary layer (<NUM>), comprising a second material different from the first material covering the second electrode (<NUM>) and located in the first and second regions, the second auxiliary layer being not located in the third region; and
a third electrode (<NUM>) comprising a metal on the second electrode in the third region,
wherein an adhesion of the metal of the second electrode with the first material is greater than an adhesion of the metal of the third electrode with the second material.