KR20120045477A - Organic light emitting display device - Google Patents

Abstract

PURPOSE: An organic electroluminescence display device is provided to prevent display malfunction by preventing penetration of external air to an edge region. CONSTITUTION: A display part is formed on a substrate. A moisture absorption member(140) is formed on an outer region of the substrate. A multi protective film(150) is formed on the substrate by covering the display part and the moisture absorption member. The moisture absorption member has a rectangular shape in order to surround the outer region of the display part.

Description

Organic Light Emitting Display Device

Embodiments of the present invention relate to an organic light emitting display device.

The organic light emitting display device used in the organic light emitting display device is a self-light emitting device having a light emitting layer formed between two electrodes positioned on a substrate. The organic light emitting display includes a top emission type, a bottom emission type, or a dual emission type according to a direction in which light is emitted. According to the driving method, it is divided into a passive matrix type and an active matrix type.

The subpixels disposed on the display panel of the organic light emitting display device may include a transistor unit including a switching transistor, a driving transistor, and a capacitor, and an organic light emitting diode including a lower electrode, an organic light emitting layer, and an upper electrode connected to a driving transistor included in the transistor unit. It includes.

When the scan signal, the data signal, and the power are supplied to the plurality of subpixels arranged in a matrix form, the organic light emitting display device may display an image by emitting light of the selected subpixel.

Since the display panel of the organic light emitting display device is vulnerable to moisture such as moisture or oxygen, a sealing process is required to protect the device when manufacturing the display panel. Background Art Conventionally, a method of protecting an element from external air by using a multi-protective film formed by alternating an inorganic layer and an organic layer when manufacturing a display panel has been proposed. However, the conventional organic light emitting display device employing the multi-layer protective film has a difficulty in blocking external air penetrating through the edge area, and thus an improvement thereof is required.

An embodiment of the present invention for solving the problems of the above-mentioned background art is to improve the blocking property of the outside air penetrating the edge region in the structure in which a multi-layered protective film made of a thin film of multiple layers as a material for encapsulating the substrate is adopted. SUMMARY OF THE INVENTION An organic light emitting display device capable of preventing a decrease in lifetime and display failure due to contamination or progressive dark spots thereof is provided.

Embodiments of the present invention as a means for solving the above problems, the substrate; A display unit formed on the substrate; Hygroscopic member formed on the outside of the substrate; And a multi passivation layer formed on the substrate and covering the display unit and the moisture absorbing member.

The moisture absorbing member may have a rectangular shape so as to surround the outside of the display unit.

The moisture absorbing member may have a quadrangular shape so as to surround the outside of the display unit, and at least one region may be opened.

The moisture absorbing member may be formed such that the plurality of moisture absorbing members surround an outer portion of the display unit.

The moisture absorbing member may include a first moisture absorbing member formed at an outer side of the substrate and a second moisture absorbing member included in the multi-protective film at a position corresponding to the first moisture absorbing member.

The moisture absorbing member may be formed to be buried in the outer portion of the substrate.

The edge region of the multi passivation layer covering the moisture absorbing member may be a curved surface.

The moisture absorbing member may be formed n (at least two) in the outer direction of the substrate.

The multi passivation layer may have a structure in which at least one inorganic passivation layer and at least one organic passivation layer are alternately stacked.

In the embodiment of the present invention, in the structure in which a multi-layered protective film made of a multilayer thin film is adopted as a material for encapsulating the substrate, the blockage of external air penetrated into the edge region is increased, thereby reducing the lifespan due to contamination of the device or consequent dark spots. And an organic light emitting display device capable of preventing display defects.

1 is a schematic block diagram of an organic light emitting display device.
FIG. 2 is an exemplary circuit diagram of a subpixel illustrated in FIG. 1. FIG.
3 is a plan view of a display panel according to a first exemplary embodiment of the present invention.
4 is a cross-sectional view of a subpixel included in a display panel.
FIG. 5 is a sectional view according to the first embodiment of the region I1-I2 shown in FIG. 3; FIG.
6 is a cross-sectional view according to another embodiment of FIG. 5.
FIG. 7 is a sectional view according to a second embodiment of the region I1-I2 shown in FIG. 3; FIG.
8 is a cross-sectional view according to a third embodiment of the region I1-I2 shown in FIG.
9 to 11 are views for explaining an arrangement structure of the moisture absorbing member.

Hereinafter, with reference to the accompanying drawings, the specific content for the practice of the present invention will be described.

FIG. 1 is a schematic block diagram of an organic light emitting display device, and FIG. 2 is an exemplary circuit diagram of a subpixel shown in FIG. 1.

As shown in FIG. 1, the organic light emitting display device includes a timing driver TCN, a display panel PNL, a scan driver SDRV, and a data driver DVB.

The timing driver TCN receives a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal Data Enable, DE, a clock signal CLK, and a data signal RGB from the outside. The timing driver TCN scans the data driver DDRV using timing signals such as the vertical synchronization signal Vsync, the horizontal synchronization signal Hsync, the data enable signal Data Enable, and the clock signal CLK. The operation timing of the driver SDRV is controlled. Since the timing driver TCN may determine the frame period by counting the data enable signal DE of one horizontal period, the vertical synchronization signal Vsync and the horizontal synchronization signal Hsync supplied from the outside may be omitted. The control signals generated by the timing driver TCN include a gate timing control signal GDC for controlling the operation timing of the scan driver SDRV and a data timing control signal DDC for controlling the operation timing of the data driver DDR. ) May be included. The gate timing control signal GDC includes a gate start pulse (GSP), a gate shift clock (GSC), a gate output enable signal (Gate Output Enable, GOE), and the like. The gate start pulse GSP is supplied to the scan driver SDRV where the first scan signal is generated. The gate shift clock GSC is a clock signal commonly input to the scan driver SDRV, and is a clock signal for shifting the gate start pulse GSP. The gate output enable signal GOE controls the output of the scan driver SDRV. The data timing control signal DDC includes a source start pulse (Source, Start Pulse, SSP), a source sampling clock (SSC), a source output enable signal (Source Output Enable, SOE), and the like. The source start pulse SSP controls the data sampling start time of the data driver DDRV. The source sampling clock SSC is a clock signal that controls the sampling operation of data in the data driver DDRV based on the rising or falling edge. The source output enable signal SOE controls the output of the data driver DDRV. Meanwhile, the source start pulse SSP supplied to the data driver DVV may be omitted according to the data transmission method.

The display panel PNL includes a display unit having subpixels SP arranged in a matrix. The subpixels SP may be formed in a passive matrix type or an active matrix type. When the subpixels SP are formed in an active matrix type, they are composed of a 2T (Capacitor) structure including a switching transistor, a driving transistor, a capacitor, and an organic light emitting diode, or a transistor such as 3T1C, 4T1C, 5T2C, or the like. It may also be of a structure in which a capacitor is further added. The subpixels SP having the above configuration may be formed in a top-emission method, a bottom-emission method, or a dual-emission method according to a structure. Meanwhile, the subpixels SP having the 2T1C structure may have a structure as illustrated in FIG. 2, which will be described below. In the switching transistor S1, a gate electrode is connected to the scan line SL1 to which the scan signal is supplied, and one end thereof is connected to the data line DL1 to which the data signal is supplied, and the other end thereof is connected to the first node A. The driving transistor T1 is a third node C connected to a second power line VSS to which a gate electrode is connected to the first node A, one end is connected to the second node B, and a low potential power is supplied. The other end is connected. One end of the capacitor Cst is connected to the first node A, and the other end thereof is connected to the third node C. In the organic light emitting diode D, an anode electrode is connected to the first power line VDD to which a high potential power is supplied, and a cathode electrode is connected to one end of the second node B and the driving transistor T1. In the above description, the transistors S1 and T1 included in one sub-pixel SP are configured as N-types as an example, but embodiments of the present invention are not limited thereto. The high potential power supplied through the first power wiring VDD may be higher than the low potential power supplied through the second power wiring VSS, and the first power wiring VDD and the second power wiring VSS. The level of power supplied through the switch can be switched according to the driving method. The subpixel SP described above may operate as follows. When the scan signal is supplied through the scan line SL1, the switching transistor S1 is turned on. Next, when the data signal supplied through the data line DL1 is supplied to the first node A through the switching transistor S1 turned on, the data signal is stored as a data voltage in the capacitor Cst. Next, when the scan signal is blocked and the switching transistor S1 is turned off, the driving transistor T1 is driven in response to the data voltage stored in the capacitor Cst. Next, when the high potential power supplied through the first power line VDD flows through the second power line VSS, the organic light emitting diode D emits light. However, this is only an example of the driving method, the embodiment of the present invention is not limited thereto.

The scan driver SDRV is a swing width of the gate driving voltage at which the transistors of the subpixels SP included in the display panel PNL can operate in response to the gate timing control signal GDC supplied from the timing driver TCN. Scan signals are sequentially generated while shifting the level of the signals. The scan driver SDRV supplies the scan signals generated through the scan lines SL1 to SLm to the subpixels SP included in the display panel PNL.

The data driver DDRV samples and latches the digital data signal RGB supplied from the timing driver TCN in response to the data timing control signal DDC supplied from the timing driver TCN. Convert to The data driver DVV converts the digital data signal RGB into a gamma reference voltage and converts the data into an analog data signal. The data driver DDRV supplies the data signal converted through the data lines DL1 to DLn to the subpixels SP included in the display panel PNL.

According to the exemplary embodiment of the present invention, the display panel PNL described above is formed in the following structure.

3 is a plan view of a display panel according to a first embodiment of the present invention, FIG. 4 is a cross-sectional view of a subpixel included in the display panel, and FIG. 5 is a first embodiment of the region I1-I2 shown in FIG. 6 is a cross-sectional view according to an example, and FIG. 6 is a cross-sectional view according to another embodiment of FIG. 5.

As shown in FIG. 3, the display panel according to the first exemplary embodiment of the present invention includes a display portion AA (called a display area) formed on the substrate 110. The display unit AA may be formed on the buffer layer 111 (also called a barrier layer). The buffer layer 111 is formed for the purpose of protecting the thin film transistor and the like formed in a subsequent process from impurities such as alkali ions flowing out of the substrate 110. Sub-pixels are formed in a matrix in the display unit AA.

The moisture absorbing member 140 is formed in the non-display portion NA (called a bezel area) that is the outer portion of the substrate 110. The moisture absorbing member 140 may be selected from materials such as silica, calcium, barium, calcium oxide, barium oxide, and baO that may absorb and adsorb moisture and gas. However, the present invention is not limited thereto. The moisture absorbing member 140 may be formed by screen printing, inkjet printing, or the like depending on the material. The moisture absorbing member 140 may be formed in a quadrangular shape so as to surround the outside of the display unit AA.

A multi passivation layer 150 is formed on the substrate 110 to cover the display portion AA and the moisture absorbing member 140. The multi passivation layer 150 has a structure in which at least one inorganic passivation layer and at least one organic passivation layer are alternately stacked.

As illustrated in FIG. 4, the subpixels included in the display panel may have the following structure.

The gate electrode 112 is formed on the buffer layer 111. The gate electrode 112 is selected from the group consisting of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu). It may be formed of a single layer or multiple layers of any one or alloys thereof. The first insulating layer 113 is formed on the gate electrode 112. The first insulating layer 113 may be SiOx, SiNx, or multiple layers thereof, but is not limited thereto. The active layer 114 is formed on the first insulating layer 113. The active layer 114 may include amorphous silicon or polycrystalline silicon crystallized therefrom. Although not illustrated, the active layer 114 may include a channel region, a source region, and a drain region, and the source region and the drain region may be doped with P-type or N-type impurities. In addition, the active layer 114 may include an ohmic contact layer to lower the contact resistance. The source electrode 115a and the drain electrode 115b are formed on the active layer 114. The source electrode 115a and the drain electrode 115b may be formed of a single layer or multiple layers. When the source electrode 115a and the drain electrode 115b have a single layer, Mo, Al, Cr, Au, Ti, Ni, It is formed of a single layer or multiple layers of any one or an alloy thereof selected from the group consisting of Nd and Cu. The second insulating layer 116 is formed on the source electrode 115a and the drain electrode 115b. The second insulating layer 116 may be SiOx, SiNx, or multiple layers thereof, but is not limited thereto. The third insulating layer 117 is formed on the second insulating layer 116. The third insulating layer 117 may be SiOx, SiNx, or multiple layers thereof, but is not limited thereto. The lower electrode 119 connected to the source / drain electrodes 115a and 115b is formed on the third insulating layer 117. The lower electrode 119 may be selected as an anode or a cathode electrode. The bank layer 120 having an opening exposing a portion of the lower electrode 119 is formed on the lower electrode 119. The bank layer 120 may include organic materials such as benzocyclobutene (BCB) resin, acrylic resin, or polyimide resin, but is not limited thereto. The organic emission layer 121 is formed in the opening of the bank layer 120. The organic emission layer 121 may include, but is not limited to, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. The upper electrode 122 is formed on the organic emission layer 121. The upper electrode 122 may be selected as a cathode or an anode electrode. The multi passivation layer 150 is formed on the upper electrode 122. The subpixels may be formed in various ways according to the structure and manufacturing method of the thin film transistor array and the organic light emitting diode unit as well as the structure described above.

As shown in FIG. 5, the multi passivation layer 150 is stacked in the order of the inorganic passivation layer 151 and the organic passivation layer 152 so as to cover the moisture absorbing member 140 and the display unit AA formed on the outer side of the substrate 110. It has a two-layer structure. However, the multi passivation layer 150 may be formed in various ways, such as a four-layer structure stacked in order of inorganic, organic, inorganic and organic protective film. Meanwhile, the multi passivation layer 150 may be formed to cover the inorganic passivation layer 151 completely, as shown in FIG. 6, as well as the structure completely covering the organic passivation layer 152. In addition, the multi passivation layer 150 may be formed such that an edge region covering the moisture absorbing member 140 forms a curved surface.

As such, when the moisture absorbing member 140 is formed on the outer side of the substrate 110 and the multi-protective layer 150 is formed to cover the moisture absorbing member 140, the edge region of the outer side of the substrate 110 and the multi-protective layer 150 are formed. The moisture absorbing member 140 penetrates through the outside air can be easily blocked. First of all, the structure formed when the edge region of the multi passivation layer 150 has a curved surface as in the embodiment has a disadvantage in that it is vulnerable to infiltration of outside air into the edge region. However, since the moisture absorbing member 140 is formed in the edge region of the multi passivation layer 150 as in the embodiment, this disadvantage can be substantially improved.

Hereinafter, various structures of the moisture absorbing member 140 and the multi passivation layer 150 will be described for each embodiment.

FIG. 7 is a cross-sectional view of a second embodiment of the region I1-I2 illustrated in FIG. 3.

As shown in FIG. 7, the moisture absorbing member 140 is included in the multi-protective film 150 at a position corresponding to the first moisture absorbing member 141 and the first moisture absorbing member 141 formed on the outer side of the substrate 110. It includes a second moisture absorbing member 142. In the second embodiment, the second moisture absorbing member 142 is formed on the inorganic protective film 151 included in the multi passivation film 150, but the second moisture absorbing member 142 forms the multi passivation film 150. It may be formed in each layer. Here, the moisture absorbing member 140 may have a rectangular shape so as to surround the outside of the display unit AA, but is not limited thereto. In the second embodiment, unlike the first embodiment, the moisture absorbing member 140 is included in the substrate 110 and the multi passivation layer 150, thereby further improving the blocking property of outside air penetrating into the edge region.

FIG. 8 is a cross-sectional view of a third embodiment of the region I1-I2 shown in FIG. 3.

As shown in FIG. 8, the moisture absorbing member 140 is formed to be buried in the outer portion of the substrate 110. To this end, a method of etching to form a predetermined space on the outside of the substrate 110 and forming the moisture absorbing member 140 in the etched region may be selected, but is not limited thereto. Here, the moisture absorbing member 140 may have a rectangular shape so as to surround the outside of the display unit AA, but is not limited thereto. Here, the moisture absorbing member 140 is selected from materials such as silica (Sillica), calcium (Ca), barium (Ba), calcium oxide (CaO), barium oxide (BaO) that can absorb and adsorb moisture and gas. It may be, but is not limited to such. The moisture absorbing member 140 may be formed by screen printing, inkjet printing, or the like depending on the material.

Hereinafter, various arrangement structures of the moisture absorbing member 140 will be described.

9 and 10 are views for explaining the arrangement structure of the moisture absorbing member.

As illustrated in FIG. 9, the moisture absorbing member 140 is formed to surround the display unit AA at an outer side of the substrate 110, and is formed to open both portions of the display unit AA. The moisture absorbing member 140 may be formed to avoid wires or other structures formed on the substrate 110 as described above. Here, the moisture absorbing member 140 is selected from materials such as silica (Sillica), calcium (Ca), barium (Ba), calcium oxide (CaO), barium oxide (BaO) that can absorb and adsorb moisture and gas. It may be, but is not limited to such. The moisture absorbing member 140 may be formed by screen printing, inkjet printing, or the like depending on the material.

As shown in FIG. 10, the moisture absorbing member 140 is formed to surround the display portion AA at the outer side of the substrate 110, and the plurality of moisture absorbing members 140 are divided into unit shapes to form the outer portion of the display portion AA. It can be formed to surround. Here, the moisture absorbing member 140 is selected from materials such as silica (Sillica), calcium (Ca), barium (Ba), calcium oxide (CaO), barium oxide (BaO) that can absorb and adsorb moisture and gas. It may be, but is not limited to such. The moisture absorbing member 140 may be formed by screen printing, inkjet printing, or the like depending on the material.

As illustrated in FIG. 11, the moisture absorbing member 140 is formed to surround the display portion AA at the outer side of the substrate 110, and the plurality of moisture absorbing members 140 are n outer portions (n is at least two). It can be formed to be located. Here, the moisture absorbing member 140 is selected from materials such as silica (Sillica), calcium (Ca), barium (Ba), calcium oxide (CaO), barium oxide (BaO) that can absorb and adsorb moisture and gas. It may be, but is not limited to such. The moisture absorbing member 140 may be formed by screen printing, inkjet printing, or the like depending on the material.

As described above, the present invention improves the barrier property of external air penetrating into the edge region in a structure in which a multi-layered thin film is adopted as a material for encapsulating a substrate, thereby deteriorating the life and display defects due to contamination of the device or consequent dark spots. There is an effect that can provide an organic light emitting display device that can prevent the. In addition, according to the present invention, when forming a multi-layer protective film formed of a thin film, it is possible to improve the degree of freedom of the process and to increase the freedom of setting the thickness of the organic material and the range of the bezel region.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention described above may be modified in other specific forms by those skilled in the art to which the present invention pertains without changing its technical spirit or essential features. It will be appreciated that it may be practiced. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all aspects. In addition, the scope of the present invention is shown by the claims below, rather than the above detailed description. Also, it is to be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention.

110: substrate AA: display portion
NA: non-display section 111: buffer layer
140: moisture absorbing member 150: multi-protective film

Claims (9)

Board;
A display unit formed on the substrate;
Hygroscopic member formed on the outer periphery of the substrate; And
And a multi-protective layer formed on the substrate and covering the display unit and the moisture absorbing member. The method of claim 1,
The moisture absorption member,
The organic light emitting display device having a rectangular shape so as to surround the outside of the display unit. The method of claim 1,
The moisture absorption member,
The organic light emitting display device of claim 1, wherein the organic light emitting display device has a rectangular shape so as to surround the outside of the display unit, and at least one region is opened. The method of claim 1,
The moisture absorption member,
An organic light emitting display device, characterized in that a plurality of moisture absorbing members are formed to surround the outside of the display unit. The method of claim 1,
The moisture absorption member,
A first moisture absorption member formed on an outer side of the substrate;
An organic light emitting display device comprising a second moisture absorbing member included in the multi passivation layer at a position corresponding to the first moisture absorbing member. The method of claim 1,
The moisture absorption member,
The organic light emitting display device of claim 1, wherein the organic light emitting display device is formed to be buried outside the substrate. The method of claim 1,
And an edge region of the multi passivation layer covering the moisture absorbing member is a curved surface. The method of claim 1,
The moisture absorption member,
And n (at least two) in the outward direction of the substrate. The method of claim 1,
The multi protective film,
An organic light emitting display device having a structure in which at least one inorganic protective film and at least one organic protective film are alternately stacked.

Images