Provided is a multi-display apparatus. The multi-display apparatus includes a first display including a region configured to allow external light to pass therethrough, a first module electrically coupled to the first display unit, a second display coupled to the first display, the second display overlapping the first module and being configured to not allow external light to pass therethrough, and a second module electrically coupled to the second display.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of Korean Patent Application No. 10-2012-0131106, filed on Nov. 19, 2012, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

Aspects of the present invention relate to a multi-display apparatus.

2. Description of the Related Art

In general, flat panel display devices may be classified as a light emission type or a light receiving type. Light emitting display apparatuses may include organic light emitting display devices (OLEDs), plasma display panels (PDPs), cathode ray tubes (CRTs), vacuum fluorescent display panels (VFDs), and light emitting diode panels (LEDs). Light receiving display apparatuses may include liquid crystal display (LCD) panels.

Among the above displays, an organic light emitting display device has advantages of a wide viewing angle, high contrast, and fast response speed. Accordingly, the organic light emitting display devices may be utilized for mobile devices such as digital cameras, video cameras, camcorders, portable information terminals, smartphones, ultra slim notebooks, tablet PCs, and electronic/electric appliances such as ultra slim televisions.

In a case of a large-sized window display device used as displays in stores, there is a limitation in forming the large-sized window display by using one display unit. Therefore, such a large-screen display may be realized by arranging a plurality of display units in a tiling way.

When forming a multi-display apparatus, transparent display units may be used so that displayed goods in stores may be seen from outside the store. However, if a plurality of transparent display units are arranged, module units having circuit boards included in the display units may be undesirably visible on certain portions, for example, bonding or attaching portions between the plurality of display units.

SUMMARY

Exemplary embodiments according to the present invention provide a multi-display apparatus that does not expose module units located at bonded or interfacing portions between display units to be visible from the outside, when a large screen is realized by combining a plurality of display units.

According to an aspect of the present invention, there is provided a multi-display apparatus including a first display comprising a region configured to allow external light to pass therethrough; a first module electrically coupled to the first display; a second display coupled to the first display, the second display overlapping the first module and being configured to not allow external light to pass therethrough; and a second module electrically coupled to the second display.

The first display and the second display may be alternately arranged in a direction and coupled to each other, and the first module may be coupled to a pad at an edge of the first display that is coupled to the second display.

The direction may be a vertical direction, and the first module may be behind the second display.

The direction may be a vertical direction, and the first module and the second module may be behind the second display.

The second display may cover the first module and the second module.

A plurality of the first displays may be successively arranged in a horizontal direction, and a plurality of the second displays may be successively arranged in the horizontal direction, and the first and second displays may be alternately arranged in a vertical direction.

The first module may be at a lower edge of the first display in the vertical direction, and may be behind the second display that is coupled to the first display in the vertical direction.

The first module and the second module may be at lower edges of the first display and the second display in the vertical direction, respectively, and the first module and the second module may be behind the second display.

A height of the first display may be greater than a height of the second display.

The second display may cover the first module and the second module.

The first module and the second module may include flexible circuit boards that are electrically coupled to a pad of the first display and a pad of the second display, respectively.

The first display may include a transparent organic light emitting display apparatus including: a substrate; an encapsulation unit on the substrate; a plurality of pixels on the substrate, wherein each of the pixels may include: a first region comprising a light emission region; and a second region comprising a transmission region configured to allow external light to pass therethrough; and an organic light emitting device at the light emission region of the pixels, and including a first electrode, a light emission layer, and a second electrode.

Each of the pixels may include: a pixel circuit comprising a thin film transistor (TFT) at the first region; a first insulating layer covering the pixel circuit; and a second insulating layer on the first insulating layer, covering edges of the first electrode, electrically coupled to the pixel circuit, and including a transmission window at the second region.

The first region of each of the pixels may include a light emission region and a circuit region, the TFT may be at the circuit region, the first electrode may be at the light emission region, and the light emission region and the circuit region may be adjacent to each other in each of the pixels.

The second region may be independently formed in each of the pixels.

The second regions of at least two adjacent pixels may be coupled to each other.

The transmission window may include a portion of the second insulating layer removed at a location corresponding to the second region.

The second display may include an opaque organic light emitting display, and the opaque organic light emitting display may include: a substrate; an encapsulation unit on the substrate; a thin film transistor (TFT) on the substrate, the TFT including a semiconductor active layer, a gate electrode, a source electrode, a drain electrode, and a plurality of insulating layers between the electrodes; and an organic light emitting device electrically coupled to the TFT comprising a first electrode, an organic emission layer on the first electrode, and a second electrode on the organic emission layer in each of pixels, wherein the opaque organic light emitting display is configured to not allow external light to pass therethrough.

The multi-display apparatus may further include a plurality of pixels at the substrate, wherein the pixels may include a light emission region and a non-emission region, and a reflective layer at a surface of the encapsulation unit facing the substrate, wherein the reflective layer may include openings corresponding to the light emission region and a reflective surface formed around the openings and corresponding to the non-emission region.

The non-emission region may further include a transmission region overlapping the reflective surface.

DETAILED DESCRIPTION

It will be understood that although the terms “first” and “second” are used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, a “first” element discussed below could be termed a “second” element, and similarly, a “second” element may be termed a “first” element without departing from the teachings of this disclosure.

Hereinafter, embodiments of a multi-display apparatus according to the present invention will be described in detail with reference to accompanying drawings. Further, when elements of the present invention are the same as those of a conventional art, they are represented by the same reference numbers or characters as used in the conventional art, and a detailed description thereof will be omitted.

FIG. 1is a schematic cross-sectional view of a display unit100according to an embodiment of the present invention.

In the present embodiment, the display unit100is an organic light emitting display device; however, the present invention is not limited thereto, provided that the display unit may display images when an electric power (e.g., a predetermined electric power) is applied thereto.

For example, the display unit100may be a liquid crystal display (LCD) panel, a plasma display panel (PDP), a light emitting diode (LED) panel, an electrochromic display panel, an electrowetting display panel, or a thin film electroluminescent (TFEL) panel.

Referring toFIG. 1, the display unit100includes a substrate110, an organic emission unit120formed on the substrate110, and an encapsulation unit130for sealing the organic emission unit120.

The encapsulation unit130may be formed of a transparent material, for example, a glass material or a plastic material, so as to display images emitted from the organic emission unit120. The encapsulation unit130reduces or prevents external air and moisture from infiltrating into the organic emission unit120.

A sealing member140is formed along edges of surfaces of the substrate110and the encapsulation unit130, which face each other. The substrate110and the encapsulation unit130may be coupled to each other by the sealing member140. A moisture absorbent material or a filler material may be filled or deposited in an inner space150between the substrate110and the encapsulation unit130.

FIG. 2is a schematic cross-sectional view of a display unit200according to another embodiment of the present invention.

Referring toFIG. 2, the display unit200includes a substrate210, an organic emission unit220formed on the substrate210, and an encapsulation unit230for sealing the organic emission unit220.

The encapsulation unit130ofFIG. 1is a substrate having rigidity, while the encapsulation unit230of the present embodiment is a flexible film. The encapsulation unit230surrounds the organic emission unit220without forming a gap between the organic emission unit220and the encapsulation unit230.

The encapsulation unit230may be formed of multiple layers (e.g., alternately formed) of an inorganic film formed of silicon oxide (SiO2) or a silicon nitride (SiNx) and an organic film formed of an epoxy or polyimide; however, the present invention is not limited thereto. That is, the encapsulation unit230may have any kind of transparent thin film encapsulation structure.

Although not shown inFIG. 2, as an encapsulation structure of the organic emission unit220, the encapsulation unit130ofFIG. 1may be further formed or located on the encapsulation unit230ofFIG. 2.

FIG. 3is a plan view showing arrangement of a display unit300and a module unit310according to another embodiment of the present invention.

Referring toFIG. 3, the display unit300includes a display area301, and a non-display area302extending along the edges (e.g., the periphery) of the display area301.

The display area301is an area on which the organic emission unit and a thin film transistor (TFT) are patterned to display images when operating. The non-display area302is an area on which a sealing material for sealing the substrate or wires electrically coupled to patterned layers of the display area301are formed. A plurality of pads303that are electrically coupled to devices formed in the display area301are arranged (e.g., located) at a portion of the non-display area302.

The module unit310is coupled to the plurality of pads303. The module unit310includes a circuit board311. The circuit board311may be a flexible printed cable (FPC) that is a flexible substrate. A plurality of circuit terminals312are positioned (e.g., arranged or located) on the circuit board311. The circuit terminals312may be coupled to the pads303via a thermal bonding process using an anisotropic conductive film (ACF) or a soldering process.

FIG. 4is a schematic cross-sectional view of a light transmissive display unit400according to an embodiment of the present invention.

In the embodiment ofFIG. 4, the light transmissive display unit400may be an organic light emitting display apparatus; however, the present invention is not limited thereto. That is, any suitable kind of display device that displays images when an electric power (e.g., a predetermined electric power) is applied may be used as the light transmissive display unit400.

Referring toFIG. 4, the light transmissive display unit400includes a display unit420formed on a substrate410. The light transmissive unit400is configured to allow external light to pass or be transmitted through the substrate410and the display unit420.

The display unit420includes a portion (e.g., region440) configured to allow the external light to be transmitted therethrough. Thus, a user located at a side displaying the images may observe objects on the other side (e.g., the upper side of the substrate410inFIG. 4).

In the present embodiment, the display unit420is a bottom emission type in which the images are displayed toward the substrate410; however, the present invention is not limited thereto. That is, the present invention may be applied to a top emission type in which the images of the display unit420are displayed in a direction away from the substrate410. In such a case, the user may see the images of the display unit420from an upper side of the substrate410, and may also observe objects on the other side of the substrate410(e.g., a lower side of the substrate410inFIG. 4).

Embodiments of the present invention are not limited to the top emission type display unit or the bottom emission type display unit, but may also be applied to a dual-emission type display unit, in which images of the display unit420may be displayed both in a direction toward the substrate410and in a direction away from the substrate410.

Here, the light transmissive display unit400includes a first pixel P1and a second pixel P2that are adjacent to each other.

Each of the pixels P1and P2includes a first region430and a second region440.

The images of the display unit420are displayed in the first region430, and external light is transmitted (e.g., passes) through the second region440.

Because each of the pixels P1and P2in the light transmissive display unit400includes the first region430for displaying images and the second region440for transmitting the external light, the user may observe images outside the light transmissive display unit400when he/she does not see the images displayed at the display unit420.

Here, devices such as a TFT, a capacitor, and an organic light emitting device are not formed at the second region440so as to increase an external light transmittance through the second region440, and accordingly, an external light transmittance of the entire display unit420may be improved. In addition, distortion of the transmission image due to interference of the devices such as the TFT, the capacitor, and the organic light emitting device may be reduced.

FIG. 5is a schematic plan view of an organic emission unit500included in a light transmissive display unit according to an embodiment of the present invention, andFIG. 6is a schematic cross-sectional view of a sub-pixel included in the organic emission unit500ofFIG. 5.

As illustrated inFIG. 5, the organic emission unit500includes a red sub-pixel Pr, a green sub-pixel Pg, and a blue sub-pixel Pbthat are adjacent to each other.

Referring toFIGS. 5 and 6, the red sub-pixel Pr, the green sub-pixel Pg, and the blue sub-pixel Pbeach include a circuit region531and a light emission region532in a first region530. The circuit region531and the light emission region532are adjacent to each other.

A second region540configured to allow external light to pass or be transmitted is adjacent to the first region530. The second region540is formed independently in each of the sub-pixels Pr, Pg, and Pb.

Alternatively, the second region540may be formed commonly throughout the sub-pixels Pr, Pg, and Pb. In this case, an area of the second region540transmitting the external light is increased, and thereby increasing a light transmittance of the entire display unit500.

Alternately, the second regions540of two adjacent sub-pixels among the red, green, and blue sub-pixels Pr, Pg, and Pbmay be coupled to each other.

As shown inFIG. 6, a TFT TR is located at the circuit region531. Embodiments of the present invention are not limited to one TFT TR, that is, a pixel circuit unit PC including the TFT TR may be formed. The pixel circuit unit PC may include a plurality of TFTs and a storage capacitor, in addition to the TFT TR, and may further include wires such as scan lines, data lines, and driving lines (Vdd lines) coupled to the above devices.

An organic light emitting device EL that is a light emission device is located at the light emission region532. The organic light emitting device EL is electrically coupled to the TFT TR of the pixel circuit unit PC.

A buffer layer611is formed on a substrate601. The pixel circuit unit PC including the TFT TR is formed on the buffer layer611.

A semiconductor active layer612is formed on the buffer layer611.

The buffer layer611is formed of a transparent insulating material. The buffer layer611reduces or prevents impurity atoms from infiltrating in the substrate601and planarizes the surface of the substrate601, and thus, may be formed of various materials capable of performing the above functions.

For example, the buffer layer611may be formed of an inorganic material such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, titanium oxide, and titanium nitride, an organic material such as polyimide, polyester, and acryl, or a stacked substance of the inorganic and organic materials. Alternatively, the buffer layer611may be omitted.

The semiconductor active layer612may be formed of a porous silicon material; however, embodiments of the present invention are not limited thereto. That is, the semiconductor active layer612may be formed of oxide semiconductor, for example, a G-I—Z—O layer ([(In2O3)a(Ga2O3)b(ZnO)c layer] (a, b, c are real numbers respectively satisfying conditions of a≧0, b≧0, c≧0). When the semiconductor active layer612is formed of the oxide semiconductor, a light transmittance of the circuit region531of the first region530may be further improved, and accordingly, the external light transmittance of the entire display unit600may be improved.

A gate insulating layer613covering the semiconductor active layer612is formed on the buffer layer611. A gate electrode614is formed at a region (e.g., a predetermined region) of the gate insulating layer613. The gate electrode614is coupled to a gate line (not shown) applying signals for turning on/off the TFT.

An interlayer dielectric615formed of a transparent insulating material is formed at the gate electrode614. A source electrode616and a drain electrode617are formed at the interlayer dielectric615, and the source electrode616and the drain electrode617are coupled to the semiconductor active layer612through contact holes that are formed by partially removing the interlayer dielectric615.

Embodiments of the present invention are not limited to the above structure, and various structures of the TFT may be applied thereto.

The structure of the TFT TR is not limited to the above example, and various kinds of TFT structures may be applied.

The first insulating layer618is formed to cover the pixel circuit unit PC including the TFT TR. The first insulating layer618may be an insulating layer having a planarized surface, and may include a single-layered or a multi-layered structure. The first insulating layer618may be formed of a transparent inorganic insulating material and/or an organic insulating material. The first insulating layer618may extend across each of the pixels.

A first electrode621of the organic light emitting device EL is electrically coupled to the drain electrode617of the TFT TR through the first insulating layer618and extends laterally across a portion of the surface of the first insulating layer618opposite the interlayer dielectric615. The first electrode621is formed as an independent island type in every pixel. For example, the first electrodes621are separated and electrically isolated from each other and correspond to respective pixels.

A second insulating layer619formed of an organic insulating material and/or an inorganic insulating material is formed on the first insulating layer618. The second insulating layer619covers edges of the first electrode621, and exposes a center portion of the first insulating layer618. The second insulating layer619may be configured to cover the first region530and the second region540of each pixel, and may be formed throughout the entire area of the organic light emission unit500of the substrate601. However, the second insulating layer619is not necessarily configured to cover the entire first region530, but covering at least a part, in particular, edges of the first electrode621, is sufficient.

In the present embodiment, the second insulating layer619is formed as a single layer; however, embodiments of the present invention are not limited thereto, that is, the second insulating layer619may have a multi-layered structure. In addition, the second insulating layer619does not necessarily have a uniform thickness, and a spacer that is formed of the same material as that of the second insulating layer619may further protrude from an upper surface of the second insulating layer619for supporting the encapsulation unit602.

An organic layer623and a second electrode622are sequentially stacked at the first electrode621, respectively. The second electrode622covers the second insulating layer619and the organic layer623, and is electrically coupled to the second electrodes622of other pixels.

The organic layer623may be formed of a low-molecular weight organic material or a high-molecular weight organic material.

When a low-molecular weight organic material is used, a single or multi-layer structure including at least one selected from the group consisting of 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 formed.

Examples of available organic materials may include copper phthalocyanine (CuPc), N,N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB), tris-8-hydroxyquinoline aluminum (Alq3), and the like. The low-molecular weight organic material may be deposited in a vacuum deposition method by using masks. Here, the HIL, the HTL, the ETL, and the EIL are common layers that are applied commonly to the red, green, and blue sub-pixels.

When a high-molecular weight organic material is used, the structure including the HTL and the EML may be used, PEDOT may be used as the HTL, and a high-molecular weight organic material such as Poly-Phenylenevinylene (PPV)-based material or a polyfluorene-based material may be used to form the organic layer in a screen printing method or an inkjet printing method.

The organic layer623is not limited to the above examples, and various examples may be applied.

The first electrode621may function as an anode and the second electrode622may function as a cathode, or vice versa.

According to the present embodiment, the first electrode621may be a transparent electrode, and the second electrode622may be a reflective electrode. The first electrode621may include a material having a high work function, for example, ITO, IZO, ZnO, In2O3, and the second electrode622may be formed of a metal material having a low work function, for example, silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), or calcium (Ca). Therefore, the organic light emitting device EL is a bottom emission type, in which the images are displayed toward the first electrode621.

However, embodiments of the present invention are not limited thereto, that is, the second electrode622may include a transparent electrode.

An encapsulation unit602is located on the second electrode622. The encapsulation unit602is bonded or attached to the substrate601by an additional sealing material (e.g., sealing member140ofFIG. 1) at an outer portion of the display unit to substantially seal the display unit from external air and contaminants. An additional filler material (not shown) may be placed in a space between the encapsulation unit602and the second electrode622, or a moisture absorbent material may be placed in the space. Encapsulation of the display unit is not limited to the sealing material602; that is, a film type encapsulation unit (e.g., encapsulation unit230ofFIG. 2) may be used.

Meanwhile, in order to improve an external light transmittance through the second region540, a first transmission window624is formed at a location corresponding to the second region540in the second insulating layer619.

The first transmission window624may be formed by removing a portion of the second insulating layer619, which corresponds to the second region540. The first transmission window624may be formed in an island pattern. Otherwise, the first transmission window624may be independently formed in each of the sub-pixels Pr, Pg, and Pb, or may be coupled throughout the pixels Pr, Pg, and Pb. In addition, the first transmission windows624of the red pixel Pr, the green pixel Pg, and the blue pixel Pbare coupled to each other, or the first transmission windows624of two adjacent pixels among the red, green, and blue pixels Pr, Pg, and Pbmay be coupled to each other.

If the first transmission window624is formed as in the present embodiment, the single first transmission window624has a large size, and thus, the external light transmittance may be improved, and the external image dispersion may be reduced.

Also, a second transmission window625may be further formed in the second electrode622. The second transmission window625may be formed by removing a portion of the second electrode622, which corresponds to the second region540. The second transmission window625may be coupled or adjacent to the first transmission window624. The second transmission window625may be also formed in the same island pattern as that of the first transmission window624.

Although not shown in the drawings, at least one of the interlayer dielectric615, the gate insulating layer613, or the buffer layer611may further include a transmission window that is coupled to the first transmission window624.

As described above, according to embodiments of the present invention, because the first and second regions530and540are separated from each other, an external image distortion generated due to the scattering of the external light by the patterns of the devices included in the pixel circuit unit PC when the external portion of the display unit is observed through the second region540may be reduced or prevented.

The first and second regions530and540are formed so that an area of the second region540may be formed in a range of 5 to 90% of the entire area of the first and second regions530and540.

If a ratio of the area of the second region540with respect to the entire combined area of the first and second regions530and540is less than 5%, the light that can be transmitted through the display unit is not sufficient for the user to see objects or images located at an opposite side when the display unit is in a turned off state. That is, the display unit is not recognized as a transparent display.

By contrast, when the ratio of the area of the second region540with respect to the entire combined area of the first and second regions530and540is greater than or equal to about 5%, and the first region530is formed as an island with respect to the entire second region540, and a high number of conductive patterns are located in the first region530to reduce a scattered degree of the external light, the user may recognize the display unit as a transparent display.

Moreover, if the TFT included in the pixel circuit unit PC is formed as a transparent TFT such as oxide semiconductor and the organic light emitting device is formed as a transparent device, the transparency may be increased more.

If the ratio of the area of the second region540with respect to the entire region of the first and second regions530and540is greater than 90%, a pixel integration of the display unit is reduced, such that images may not be effectively displayed from the light emission of the first region530.

That is, as the area of the first region530is reduced, illuminance of the light emitted from the organic layer623has to be increased in order to display images. As described above, if the organic light emitting device operates at the high brightness level, life span of the light emitting device is rapidly degraded.

Also, if the ratio of the area of the second region540is increased to 90% or greater while maintaining a size of one first region530, the area of the first region530is reduced, and thus, the resolution is degraded.

Thus, the ratio of the area of the second region540with respect to the entire area of the first and second regions530and540may be in a range of 20% to 70%.

If the above ratio is less than 20%, the area of the first region530may be excessively large when compared with the second region540, and thus, there is a limitation in observing the external images via the second region540. If the above ratio is greater than 70%, there may be a limitation in designing the pixel circuit unit PC that will be located in the first region530.

FIG. 7is a schematic cross-sectional view of a sub-pixel in a light impermeable display unit700according to another embodiment of the present invention.

Here, the light impermeable display unit700is an organic light emitting display apparatus; however, embodiments of the present invention are not limited thereto, that is, the light impermeable display unit700may be any kind of display apparatus that displays images when an electric power (e.g., a predetermined electric power) is applied thereto.

Referring toFIG. 7, the light non-transmissive display unit700includes a substrate710. At the substrate710, a pixel region PXL1including a light emission layer719, a transistor region TFT1including a TFT, and a capacitor region CAP1including a capacitor are formed.

The transistor region TFT1includes a semiconductor active layer712formed of a TFT on the substrate710and a buffer layer711. The semiconductor active layer712may include amorphous silicon or crystalline silicon. The semiconductor active layer712includes a channel region712c, and a source region712aand a drain region712bdoped with ion impurities on outer portions of the channel region712c.

A gate electrode714is formed on the semiconductor active layer712at a location corresponding to the channel region712cof the semiconductor active layer712. The gate insulating layer713is located between the gate electrode714and the channel region712cof the semiconductor active layer712.

A source electrode716aand a drain electrode716bare respectively coupled to the source region712aand the drain region712bof the semiconductor active layer. An interlayer dielectric715is located between the source and drain electrodes716aand716bat the gate electrode714.

A first insulating layer718is formed on the interlayer dielectric715to cover the source and drain electrodes716aand716b.

In the pixel region PXL1of the present embodiment, a first electrode717may be a pixel electrode formed of the same material as that of an upper electrode767of a capacitor located on the substrate710, the buffer layer711, the gate insulating layer713, and the interlayer dielectric715.

The first electrode717is formed of a transparent conductive material, and the light may be emitted toward the first electrode717. The transparent conductive material may be at least one selected from the group consisting of ITO, IZO, ZnO, In2O3, IGO, and AZO.

An organic emission layer719is formed on the first electrode717, and the light emitted from the organic emission layer719may be discharged toward the substrate710through the first electrode717formed of the transparent conductive material.

Meanwhile, the buffer layer711, the gate insulating layer713, and the interlayer dielectric715located under the first electrode717are formed of materials having different refractive indexes to serve as a distributed brag reflector (DBR), thereby improving an emission efficiency of the light emitted from the organic emission layer719. The buffer layer711, the gate insulating layer713, and the interlayer dielectric715may be formed of SiO2, SiNx, and the like.

In the present embodiment, the buffer layer711, the gate insulating layer713, and the interlayer dielectric715are formed as single layers, respectively; however, embodiments of the present invention are not limited thereto, and the above layers may respectively have multi-layered structures.

A first insulating layer718is formed on an outer portion of the first electrode717, and the interlayer dielectric715includes a first opening C1exposing the first electrode717. The organic emission layer719is formed in the first opening C1.

The organic emission layer719may be formed of a low-molecular weight organic material or a high-molecular weight organic material.

When the organic emission layer719is formed of the low-molecular weight organic material, the HIL, the HTL, and the EIL may be stacked based on the organic emission layer719. When the organic emission layer719is the high-molecular weight organic layer, the HTL may be formed in addition to the organic emission layer719.

A second electrode720is formed on the organic emission layer719as a common electrode. In the display unit700of the present embodiment, the first electrode717is used as an anode and the second electrode720is used as a cathode, or vice versa.

The second electrode720may be formed as a reflective electrode including a reflective material. Here, the second electrode720may include one or more materials selected from Al, Mg, Li, Ca, LiF/Ca, and LiF/Al.

Because the second electrode720is formed as the reflective electrode, the light emitted from the organic emission layer719is reflected by the second electrode720and is discharged toward the substrate710after transmitting through the first electrode717formed of the transparent conductive material.

In the capacitor region CAP1, a lower electrode762aof the capacitor may be formed of the same material as that of the semiconductor active layer712of the TFT, and a wiring region W1coupled to the lower electrode762a. An upper electrode767of the capacitor may be formed of the same material as that of the first electrode717. An insulating layer713between the lower electrode762aand the upper electrode767to correspond to the gate insulating layer is formed on the substrate710and the buffer layer711.

The lower electrode762aof the capacitor may be formed of the same material as the source region712aand the drain region712bof the semiconductor active layer712of the TFT, and may include a semiconductor material doped with ion impurities. If the lower electrode762ais formed of an intrinsic semiconductor material that is not doped with ion impurities, the capacitor may include a metal oxide semiconductor (MOS) capacitor (MOS CAP) structure with the upper electrode767. However, if the lower electrode762ais formed of the semiconductor material doped with the ion impurities, the capacitor may include a metal-insulator-metal (MIM) capacitor (MIM CAP) structure, thereby increasing an electrostatic capacity. Therefore, because the MIM CAP structure may realize the same electrostatic capacity with a smaller area than that of the MOS CAP structure, the area of the capacitor may be reduced by utilizing a MIM CAP structure, thereby increasing the ability to form the pixel electrode717to be large and improving an aperture ratio of the pixel electrode717.

The wiring region W1that is located at the same level as the lower electrode762aand coupled to the lower electrode762to transmit signals (electric current/voltage) is located at an outer portion of the lower electrode762a. The wiring region W1may include a semiconductor doped with ion impurities, like the lower electrode762a.

The insulating layer713is located on the lower electrode762a; however, there is a region where the insulating layer713is not formed at the outer portion of the lower electrode762aover a portion of the wiring region W1coupled to the lower electrode762a. For example, the portion of the wiring region W1where insulating layer713is not formed may be a coupling portion for coupling the lower electrode762ato the wiring region W1.

In the present embodiment, the region where the insulating layer713is not formed is described as a part of the wiring region W1; however, embodiments of the present invention are not limited thereto. That is, the above region may be an edge of the lower electrode762aitself, not the wiring region W1, because a boundary between the electrode and the wires may not be definitely designed in the capacitor region.

In the present embodiment, the insulating layer713forms a first gap G1between the wiring region W1at an outer portion of the lower electrode762awhere the insulating layer713is not formed by etching the insulating layer713when the insulating layer715corresponding to the interlayer dielectric is etched.

An upper electrode767is located on the insulating layer713corresponding to the gate insulating layer. The upper electrode767is formed of the same material as that of the first electrode717. The first electrode717includes a transparent conductive material, and the upper electrode767may include the transparent conductive material.

The upper electrode767is laterally adjacent to a region corresponding to a second gap G2, which is adjacent to the first gap G1in the insulating layer713.

The insulating layer715corresponding to the interlayer dielectric is located on the insulating layer713, and the insulating layer715includes a second opening C2exposing the upper electrode767, the insulating layer713including the first gap G1, and the insulating layer715including the second gap G2.

A first insulating layer718is formed on the insulating layer715. The first insulating layer718may include an organic insulating layer. When the first insulating layer718including the organic insulating material having a small dielectric constant is between the second electrode720and the upper electrode767, a parasitic capacitance that may be generated between the second electrode720and the upper electrode767may be reduced, thereby reducing signal interference generated due to the parasitic capacitance.

The light impermeable display unit700is opaque because a region for transmitting the external light is not formed unlike the light transmissive display unit ofFIG. 5. Therefore, the user may not see displayed objects or images from an opposite side.

The light impermeable display unit may include the light impermeable display unit that may be used as a mirror display, as well as the general light impermeable display unit shown inFIG. 7.

FIG. 13is a schematic cross-sectional view of one sub-pixel of a light impermeable display unit1300according to another embodiment of the present invention, andFIG. 14is a schematic plan view of a reflective layer1370shown inFIG. 13.

The light permeable display unit1300may be an organic light emitting display apparatus that may be used as a mirror display; however, embodiments of the present invention are not limited thereto, and a display apparatus for displaying images to which an electric power (e.g., a predetermined electric power) is applied may be used.

Referring toFIGS. 13 and 14, the light impermeable display unit1300includes a substrate1301on which a display unit is formed, and an encapsulation unit1391coupled to the substrate1301.

The sub-pixel P1ofFIG. 13includes a light emission area LA1and a non-emission area NA1.

The light emission area LA1is an area directly emitting visible rays to realize images that may be recognized by the user. On the light emission area LA1, a first electrode1311, a second electrode1312, and an organic emission layer1313are formed between the first and second electrodes1311and1312.

Also, as shown inFIG. 14, a pixel circuit unit PC may be at the light emission area LA1. Data lines D, scan lines S, and a power line V may be coupled to the pixel circuit unit PC.

A buffer layer1302is formed on the substrate1301. The buffer layer1302is a selective element, and thus, may be omitted.

A TFT TR1is formed on the buffer layer1302. The TFT TR1includes a semiconductor active layer1303, a gate electrode1305, a source electrode1307, and a drain electrode1308.

First, the semiconductor active layer1303is formed in a pattern (e.g., a predetermined pattern) on the buffer layer1302. The semiconductor active layer1303includes a source region, a drain region, and a channel region. The source and drain regions of the semiconductor active layer1303may be formed of amorphous silicon, or may be formed of crystalline silicon doped with group-III or group-V impurities.

A gate insulating layer1304is formed on the semiconductor active layer1303, and a gate electrode1305is formed on a region (e.g., a predetermined region) on the gate insulating layer1304. The gate insulating layer1304may be formed of an organic material or an inorganic material such as SiNx or SiO2for insulating the semiconductor active layer1303from the gate electrode1305.

The gate electrode1305may include Au, Ag, Cu, Ni, Pt, Pd, Al, or molybdenum (Mo), and an alloy such as aluminum-neodymium (Al:Nd) alloy or molybdenum-tungsten (Mo:W) alloy; however, embodiments of the present invention are not limited thereto. The gate electrode1305may be formed to have a single-layered structure or a multi-layered structure.

An interlayer dielectric1306is formed on the gate electrode1305. The interlayer dielectric1306and the gate insulating layer1304are formed to expose the source region and the drain region of the semiconductor active layer1303, and the source electrode1307and the drain electrode1308are formed to contact the exposed source and drain regions of the semiconductor active layer1303, respectively.

The source electrode1307and the drain electrode1308may be formed of various conductive materials, and may have single-layered or multi-layered structures.

A passivation layer1309is formed on the TFT TR1. In more detail, the passivation layer1309is formed on the source and drain electrodes1307and1308.

The passivation layer1309does not cover the entire portion of the drain electrode1308, and is configured to expose a region (e.g., a predetermined region) of the electrode1308. A first electrode1311is coupled to the exposed region of the drain electrode1308.

The first electrode1311may be formed as an independent island type in each of the sub-pixels. A pixel defining layer1319is formed on the passivation layer1318and covers the edges of the first electrode1311without covering a central region or portion of the first electrode1311.

The organic emission layer1313is formed on the first electrode1311.

The second electrode1312is formed on the organic emission layer1313.

The non-emission area NA1is formed around the light emission area LA1to be adjacent to the light emission area LA1. The non-emission area NA1may include a transmission area TA. The transmission area TA may be formed by forming a transmission window1312ain the second electrode1312.

The transmission area TA may be formed by forming the transmission window1312ain the second electrode1312and further forming a transmission window in the pixel defining layer1319. That is, the transmission window may be formed in one or more insulating layers (not shown) or one or more conductive layers (not shown) formed on the substrate.

Meanwhile, as shown inFIG. 14, the sub-pixels P1, P2, and P3, respectively, include light emission areas LA1, LA2, and LA3, and the sub-pixels P1, P2, and P3may include a common transmission window TA. However, embodiments of the present invention are not limited thereto, and the sub-pixels P1, P2, and P3may respectively include the transmission regions, like the light emission areas LA1, LA2, and LA3.

As shown inFIGS. 13 and 14, a reflective layer1370is formed on a surface of the encapsulation unit1391. In more detail, the reflective layer1370is formed on a surface of the encapsulation unit1391, which faces the substrate1301. The reflective layer1370includes one or more openings1370a1,1370a2(shown inFIG. 14), and1370a3(shown inFIG. 14), and a reflective surface1371. The reflective surface1371is disposed around the openings1370a1,1370a2, and1370a3. Also, the reflective surface1371is formed to correspond to the non-emission areas NA1, NA2, and NA3, and the openings1370a1,1370a2, and1370a3are formed to correspond to the light emission areas LA1, LA2, and LA3.

In more detail, the first opening1370a1of the reflective layer1370corresponds to the first light emission area LA1of the sub-pixel P1, the second opening1370a2of the reflective layer1370corresponds to the second light emission area LA2of the sub-pixel P2, and the third opening1370a3of the reflective layer1370corresponds to the third light emission area LA3of the sub-pixel P3. The reflective surface1371of the reflective layer1370is respectively formed at the non-emission areas NA1, NA2, and NA3of the sub-pixels P1, P2, and P3around the openings1370a1,1370a2, and1370a3. Thus, the reflective surface1371overlaps the transmission areas TA of the non-emission areas NA1, NA2, and NA3.

The reflective surface1371may be formed of a material having a high reflectivity. For example, the reflective surface1371may be formed of a metal material (e.g., a predetermined metal material), for example, Ni, Cr, W, vanadium (V), or Mo.

Also, the reflective surface1371may have a predetermined thickness. For example, the reflective surface1371may have a thickness of 500 angstroms (Å) or greater. If the thickness of the reflective surface1371is less than a desired thickness, a part of the light transmits through the reflective surface1371and the reflective surface1371has a reflectivity that is less than a desired level. Then, a mirror display function desired by the light impermeable display unit1300may not be effectively realized.

As described above, the encapsulation unit1391includes the reflective surface including the openings1370a1,1370a2, and1370a3corresponding to the light emission areas LA1, LA2, and LA3of the sub-pixels while reducing the impact on the image display of the light emission areas LA1, LA2, and LA3, and thus, the light impermeable display unit1300may function as the mirror display.

Also, the pixel circuit unit PC including the TFT TR1is disposed in the light emission areas LA1, LA2, and LA3so as to increase the light emission areas LA1, LA2, and LA3in a case of a top emission type in which the image emitted from the light emission areas LA1, LA2, and LA3is displayed toward the encapsulation unit1391, and thereby increasing the aperture ratio and improving the image quality.

Each of the pixels P1, P2, and P3selectively includes the transmission area TA in the non-emission area NA1, NA2, or NA3, and the reflective surface1371is configured to correspond to the transmission area so that the light reflected by the reflective surface1371may be effectively transmitted through the transmission area TA toward the user.

As such, when the image emitted from the light emission areas LA1, LA2, and LA3of the light impermeable display unit1300is displayed toward the encapsulation unit1391, the light reflected from the reflective surface1371is easily transmitted through the transmission area TA toward the substrate1301so that a general mirror effect may be shown at the substrate1301side.

Meanwhile, the region for performing as a mirror is not limited to a surface of the encapsulation unit1391, which faces the substrate1301, that is, a thin metal layer may be formed at an outer surface of the encapsulation unit1391to perform as a mirror.

Here, when the display unit is used as a window display in a place like a large store, a large-sized screen may be realized by arranging a plurality of display units adjacent to one another in a matrix of display units. Here, the above described light transmissive display units and the light impermeable display units are combined in order for the user to see objects or images located at an opposite side to the display apparatus.

FIG. 8is a schematic front view of a multi-display apparatus800according to an embodiment of the present invention, andFIG. 9is a schematic side view of the multi-display unit800ofFIG. 8.

Referring toFIGS. 8 and 9, the multi-display apparatus800includes at least one or more light transmissive display units, and at least one or more light impermeable display units. In the present embodiment, the light transmissive display units include a first light transmissive display unit811and a second light transmissive display unit812, and the light impermeable display units include a first light impermeable display unit821and a second light impermeable display unit822.

The first light transmissive display unit811and the second light transmissive display unit812are coupled to each other in a horizontal direction (X-axis direction), and the first light impermeable display unit821and the second light impermeable display unit822are coupled to each other in the horizontal direction (X-axis direction).

Also, the first light impermeable display unit821is coupled to the first light transmissive display unit811in a vertical direction (Y-axis direction), and the second light impermeable display unit822is coupled to the second light transmissive display unit812in the vertical direction (Y-axis direction).

As such, the plurality of light transmissive display units811and812and the plurality of light impermeable display units821and822are coupled to each other in a matrix of adjacently arranged display units. InFIG. 8, on an upper portion in the vertical direction (Y-axis direction), the first light transmissive display unit811and the second light transmissive display unit812are arranged in parallel, and on a lower portion of the vertical direction (Y-axis direction), the first light impermeable display unit821and the second light impermeable display unit822are arranged in parallel.

In the present embodiment, a pair of light transmissive display units811and812and a pair of light impermeable display units821and822are arranged above and below in the vertical direction (Y-axis direction); however, the light transmissive display units and the light impermeable display units may be arranged alternately so as to form three or more layers in the vertical direction (Y-axis direction).

Also, embodiments of the present invention are not limited to the above arranging example, that is, a pair of a light transmissive display unit and a light impermeable display unit is continuously arranged in the horizontal direction (X-axis direction), and the above pairs may be successively arranged in the vertical direction (Y-axis direction) so that the display units of the opposite types may be located above and below.

Accordingly, the user may observe an object831located at an opposite side through the first light transmissive display unit811and the second light transmissive display unit812located on the upper portion of the vertical direction (Y-axis direction).

Here, the first light transmissive display unit811includes a first module unit813at a lower edge thereof in the vertical direction (Y-axis direction), and the second light transmissive display unit812includes a second module unit814at a lower edge in the vertical direction (Y-axis direction). The first module unit813and the second module unit814include substrates such as flexible printed cables that are electrically coupled to the first light transmissive display unit811and the second light transmissive display unit812, respectively.

The first light impermeable display unit821includes a third module unit823at a lower edge thereof in the vertical direction (Y-axis direction), and the second light impermeable display unit822includes a fourth module unit824at a lower edge thereof in the vertical direction (Y-axis direction). The third module unit823and the fourth module unit824include substrates such as flexible printed cables that are electrically coupled to the first light impermeable display unit821and the second light impermeable display unit822, respectively.

Here, the first and second module units813and814are located inside of the multi-display apparatus800, and coupled (e.g., bonded or attached) at portions between the display units. The first and second module units813and814are located at sides of (e.g., overlap with) the first light impermeable display unit821and the second light impermeable display unit822, respectively. Therefore, when the user recognizes the object831located at the opposite side through the first light transmissive display unit811and the second light transmissive display unit812, the first and second module units813and814may be hidden in the multi-display apparatus800so that the user may not recognize the existence of the first and second module units813and814.

The first and second module units813and814are located at rear portions of the first light impermeable display unit821and the second light impermeable display unit822. Here, the first module unit813and the second module unit814are not fixed on a fixing members located on the first light impermeable display unit821and the second light impermeable display unit822, but may be located in curved states, because the first and second module units813and814are formed of flexible substrates.

Alternatively, the first and second module units813and814may be fixed on fixing members such as supports located on the first light impermeable display unit821and the second light impermeable display unit822.

As described above, when the large-sized display apparatus800is formed, one or more light transmissive display units811and812and one or more light impermeable display units821and822are alternately arranged in a direction, the module units813and814of the light transmissive display units811and812located at bonded or attached portions of the display units are disposed adjacent to the light transmissive display units811and812and located at rear portions of the light impermeable display units821and822that do not transmit light. Accordingly, the images may be displayed by the light impermeable display units821and822, and moreover, the object831located at the opposite side of the user may be easily observed through the light transmissive display units811and812.

FIG. 10is a schematic front view of a multi-display apparatus100according to another embodiment of the present invention, andFIG. 11is a schematic side view of the multi-display apparatus1000ofFIG. 10.

Referring toFIGS. 10 and 11, the multi-display apparatus1000includes a plurality of first through fourth light transmissive display units1011through1014, and a plurality of first through fourth light impermeable display units1111through1114.

The light transmissive display units include the first through fourth light transmissive display units1011,1012,1013, and1014, and the light impermeable display units include the first through fourth light impermeable display units1111,1112,1113, and1114, according to the present embodiment; however, the number of display units is not limited thereto.

Here, in a horizontal direction (X-axis direction) ofFIG. 10, pairs of light transmissive display units1011and1014are coupled to (e.g., engaged with) each other and pairs of light impermeable display units1111through1114are coupled to (e.g., engaged with) each other.

Also, in a vertical direction (Y-axis direction) ofFIG. 10, a pair of light transmissive display units1011through1014and a pair of light impermeable display units1111through1114are alternately arranged with each other. Here, the pair of light transmissive display units1011through1014and the pair of light impermeable display units1111through1114adjacent to the pair of the light transmissive display units are coupled to (e.g., engaged with) each other, of course.

As described above, the plurality of light transmissive display units1011through1014and the plurality of light impermeable display units1111through1114, a total number of 8, are coupled to each other in a matrix of adjacent display units so that adjacent edges are coupled to (e.g., engaged with) each other, and alternately arranged in the vertical direction (Y-axis direction).

Here, first through fourth module units1015through1018are located at lower edges of the first through fourth light transmissive display units1011through1014in the vertical direction (Y-axis direction). In addition, fifth through eighth module units1115through1118are located at lower edges of the first through fourth light impermeable display units1111through1114in the vertical direction (Y-axis direction).

The first through fourth module units1015through1018are located at bonded or attached portions between the display units and the fifth and sixth module units1115and1116of the first and second light impermeable display units1111and11112are located at sides of the first through fourth light impermeable display units1111through1114.

In more detail, the first and second module units1015and1016that are electrically coupled to the first and second light transmissive display units1011and1012and are located at upper rear portions of the first and second light impermeable display units1111and1112that are adjacent to the first and second light transmissive display units1011and1012.

Also, the fifth and sixth module units1115and1116that are electrically coupled to the first and second light impermeable display units1111and1112are located at lower rear portions of the first and second light impermeable display units1111and1112by being curved upward.

Therefore, the first and second module units1015and1016and the fifth and sixth module units1115and1116are located at the rear portions of the first and second light impermeable display units1111and1112.

The third and fourth module units1017and1018that are electrically coupled to the third and fourth light transmissive display units1013and1014are located at lower rear portions of the third and fourth light impermeable display units1113and1114that are coupled to (e.g., engaged with) the third and fourth light transmissive display units1013and1014.

On the other hand, the seventh and eighth module units1117and1118that are electrically coupled to the third and fourth light impermeable display units1113and1114are located at the outermost portion of the multi-display apparatus100in the vertical direction (Y-axis direction) thereof, and do not affect recognition of object1130. Thus, there is no need to locate the seventh and eighth module units1117and1118toward the third and fourth light impermeable display units1113and1114.

As described above, when the large-sized multi-display apparatus1000is formed, the plurality of light transmissive display units1011through1014and the plurality of light impermeable display units1111through1114are alternately arranged in the vertical direction (Y-axis direction), and the module units1015through1018of the light transmissive display units1011through1014and the module units1115and1116of the light impermeable display units1111through1114located at bonded or attached portions of the multi-display apparatus1000are located at the rear portions of the light impermeable display units1111through1114. Accordingly, general image display may be performed by the light impermeable display units1111through1114, and moreover, the object1130located at an opposite side of the user may be observed through the light transmissive display units1011through1014.

FIG. 12is a schematic front view of a multi-display apparatus1200according to another embodiment of the present invention.

Referring toFIG. 12, the multi-display apparatus1200includes a plurality of first through sixth light transmissive display units1201through1206, and a plurality of first through sixth light impermeable display units1221through1226.

In the present embodiment, the light transmissive display units include the first through sixth light transmissive display units1201,1202,1203,1204,1205, and1206, and the light impermeable display units include the first through sixth light impermeable display units1221,1222,1223,1224,1225, and1226.

Here, in a horizontal direction (X-axis direction) ofFIG. 12, two of the light transmissive display units1201through1206are coupled to (e.g., engaged with) each other, and two of the light impermeable display units1221through1226are coupled to (e.g., engaged with) each other.

In a vertical direction (Y-axis direction) ofFIG. 12, pairs of the light transmissive display units1201through1206and pairs of the light impermeable display units1221through1226are alternately arranged. Here, a pair of light transmissive display units1201through1206and a pair of light impermeable display units1221and1226, which is adjacent to the above pair of the light transmissive display units in the vertical direction, are coupled to (e.g., engaged with) each other.

Also, first through sixth module units1207through1212are located at lower edges of the first through sixth light transmissive display units1201and1206in the vertical direction (Y-axis direction). Seventh through twelfth module units1227through1232are located at lower edges of the first through sixth light impermeable display units1221and1226in the vertical direction (Y-axis direction).

Here, the plurality of module units1207through1212of the plurality of light transmissive display units1201through1206located in the multi-display apparatus1200and the plurality of module units1227through1230of the plurality of light impermeable display units1221through1224are located toward inside of the light impermeable display units1221through1226.

Here, a length (e.g., height) of the each of first through sixth light transmissive display units1201through1206in the vertical direction (Y-axis direction), that is, a longitudinal length d1is longer than a longitudinal length d2of each of the first through sixth light impermeable display units1221through1226.

Here, the longitudinal length d2of the first through sixth light impermeable display units1221through1226may be configured to have a minimum length for covering the first through sixth module units1207through1212and the seventh through tenth module units1227through1230.

The longitudinal lengths of the light transmissive display unit and the light impermeable display unit are different from each other, so that the first through sixth module units1207through1212and the seventh through tenth module units1227through1230located inside the multi-display apparatus1200are not exposed to outside, and at the same time, so that blocking of an object1240located at an opposite side of the user due to the first through sixth light impermeable display units1221through1226may be reduced or prevented.

As described above, according to the multi-display apparatus of embodiments of the present invention, the module units of the light transmissive display units, which are located in a screen where the display units are coupled (e.g., bonded or attached) when the plurality of display units are combined to one large-sized screen, are located at rear surfaces of the light impermeable display units, and accordingly, the module units are not visible through the light impermeable display units.

Also, by arranging the light transmissive display units and the light impermeable display units alternately, the module units of the light transmissive display units may not be visible.