CN106910762B - Organic light emitting diode display device - Google Patents

Abstract

An organic light emitting diode display device includes a driving substrate, at least one organic light emitting diode structure, at least one covering electrode, at least one pixel definition structure and a protective cover. The driving substrate includes at least one pixel electrode. The organic light emitting diode structure is disposed on the pixel electrode. The organic light emitting diode structure is located between the pixel electrode and the covering electrode. The pixel definition structure is disposed on the driving substrate. The pixel definition structure has a housing space. The organic light emitting diode structure and the covering electrode are located in the housing space. The protective cover covers the driving substrate, the organic light emitting diode structure, the covering electrode and the pixel definition structure. The pixel definition structure abuts the protective cover. Through the above configuration, the organic light emitting diode display device can effectively prevent moisture and/or oxygen from damaging the organic light emitting diode structure under the protective cover.

Description

Organic Light Emitting Diode Display Device

technical field

The invention relates to display technology, in particular to an organic light emitting diode display device.

Background technique

Organic light-emitting diodes are one of the mainstream display technologies due to their advantages such as self-luminescence, high operating speed, low operating voltage, and thin device layers.

Generally speaking, in a color OLED display device, different types of organic materials are usually used in different pixel regions. When electrons and holes combine in layers of different types of organic materials, different colors of light can be emitted, thereby displaying colored images. During the manufacturing process of the color organic light emitting diode display device, materials (including organic materials and electrode materials, etc.) of different pixel regions are usually vapor-deposited on the substrate. In order to facilitate evaporation of materials on desired areas, manufacturers usually use a tension mask as a shield to cover areas that do not need to be evaporated and expose areas to be evaporated. During the evaporation process, since the stretched mesh cannot be closely attached to the substrate, the material evaporated on the edge of the pixel area is prone to uneven film thickness. Such a phenomenon easily leads to a short circuit between the upper and lower electrodes or leakage current.

In order to overcome this problem, a pixel define layer (PDL) can be deposited on the substrate first, and the area to be evaporated on the substrate is exposed, and then the evaporation operation is performed.

After the evaporation of the organic material and the electrode material is completed, it will be pasted under the protective cover through the frame glue. However, since the lower surface of the protective cover is only bonded with frame glue, moisture or oxygen can easily penetrate into the bottom of the protective cover from the gap between the protective cover and the frame glue, which may damage the organic materials and electrode materials under the protective cover.

Contents of the invention

In various embodiments of the present invention, the organic light emitting diode display device can effectively prevent moisture and/or oxygen from damaging organic materials and electrode materials under the protective cover.

According to an embodiment of the present invention, an organic light emitting diode display device includes a driving substrate, at least one organic light emitting diode structure, at least one covering electrode, at least one pixel defining structure and a protective cover. The driving substrate includes at least one pixel electrode. The organic light emitting diode structure is arranged on the pixel electrode. The OLED structure is located between the pixel electrode and the cover electrode. The pixel definition structure is arranged on the driving substrate. The pixel definition structure has an accommodating space. The organic light emitting diode structure and the covering electrode are located in the accommodation space. The protective cover covers the driving substrate, the organic light emitting diode structure, the covering electrode and the pixel definition structure. The pixel definition structure rests against the protective cover.

In the above embodiments, since the organic light emitting diode structure and the cover electrode are located in the accommodating space of the pixel definition structure, and the pixel definition structure touches the protective cover, the pixel definition structure can prevent moisture and/or oxygen from penetrating into the pixel definition In the accommodating space of the structure, moisture and/or oxygen are prevented from damaging the organic light emitting diode structure.

The above description is only used to illustrate the problem to be solved by the present invention, the technical means for solving the problem, and the effects thereof.

Description of drawings

In order to make the embodiments of the present invention more obvious and understandable, the description of the accompanying drawings is as follows:

1 shows a schematic cross-sectional view of an organic light emitting diode display device according to an embodiment of the present invention;

2 shows a schematic cross-sectional view of an OLED display device according to an embodiment of the present invention; and

FIG. 3 is a schematic cross-sectional view of an OLED display device according to an embodiment of the present invention.

Detailed ways

A number of embodiments of the present invention will be disclosed below with the accompanying drawings. For the sake of clarity, many practical details will be described together in the following description. However, those skilled in the art should understand that in another embodiment of the present invention, these practical details are not necessary and thus should not be used to limit the present invention. In addition, for the sake of simplifying the drawings, some known and conventional structures and elements will be shown in a simple and schematic manner in the drawings.

FIG. 1 is a schematic cross-sectional view of an OLED display device according to an embodiment of the present invention. As shown in FIG. 1 , in this embodiment, an OLED display device includes a driving substrate 100 , an OLED structure 200 , a cover electrode 300 , a pixel definition structure 400 and a protective cover 500 . The driving substrate 100 includes a pixel electrode 110 . The OLED structure 200 is disposed on the pixel electrode 110 . The cover electrode 300 is disposed on the OLED structure 200 . In other words, the OLED structure 200 is located between the pixel electrode 110 and the cover electrode 300 , and can be driven by the pixel electrode 110 and the cover electrode 300 to emit light. The pixel definition structure 400 is disposed on the driving substrate 100 . The pixel definition structure 400 has an accommodating space S. The bottom opening of the pixel electrode 110 is partially exposed in the accommodating space S. As shown in FIG. The OLED structure 200 and the cover electrode 300 are located in the containing space S. Referring to FIG. The protective cover 500 covers the driving substrate 100 and the OLED structure 200 . The pixel definition structure 400 abuts against the protective cover 500 .

In this embodiment, since the pixel defining structure 400 is against the protective cover 500, and the organic light emitting diode structure 200 and the cover electrode 300 are located in the accommodation space S of the pixel defining structure 400, and the pixel electrode 110 is partially exposed in the accommodation space S. The bottom of the space S is open, therefore, the pixel definition structure 400 against the protective cover 500 can prevent moisture and/or oxygen from penetrating into the accommodating space S of the pixel definition structure 400, thereby preventing moisture and/or oxygen from damaging the covering electrodes 300 . The OLED structure 200 and the pixel electrode 110 . In other words, in this embodiment, the effect of blocking moisture and/or oxygen can be achieved by utilizing the pixel defining structure 400 .

In some implementations, the pixel defining structure 400 and the protective cover 500 can be pressed against or bonded together. The resistive force or adhesive strength of the two is strong enough to prevent gas and/or liquid from penetrating into the accommodating space S of the pixel defining structure 400 to further block moisture and/or oxygen. For example, in some implementations, the pixel defining structure 400 and the protective cover 500 are glued together with waterproof glue to block moisture and/or oxygen.

In some implementations, the OLED structure 200 and the cover electrode 300 are in close contact with the inner wall of the accommodating space S of the pixel defining structure 400 . Further, before fabricating the OLED structure 200 and the cover electrode 300 , the pixel definition structure 400 can be formed on the driving substrate 100 first. Next, the material of the OLED structure 200 and the material of the covering electrode 300 can be deposited in the accommodating space S of the pixel definition structure 400 . The organic light emitting diode structure 200 and the covering electrode 300 formed in the above manner can closely contact the inner wall of the accommodating space S of the pixel defining structure 400 . In some embodiments, the deposition method of the OLED structure 200 and the material covering the electrode 300 may include physical vapor deposition (such as evaporation or sputtering) or chemical vapor deposition, but the invention is not limited thereto.

In some implementations, the pixel definition structure 400 can be used to reflect the light emitted by the OLED structure 200 back into the accommodating space S. Referring to FIG. In this way, even though the OLED structure 200 may emit lateral light and cause the light to enter the pixel definition structure 400, the pixel definition structure 400 can also reflect the light back into the accommodating space S, so as to improve the light intensity above the OLED structure 200. brightness. In some implementations, the cover electrode 300 is separated from the protective cover 500 by a gap, and the medium (such as nitrogen gas) in the gap has a different refractive index from the material of the cover electrode 300 . If the refractive index difference between the material of the covering electrode 300 and the medium above the covering electrode 300 (such as nitrogen and other gases) is too large, resulting in total reflection of light on the upper surface of the covering electrode 300 and entering the pixel definition structure 400, the pixel definition structure 400 The light can also be reflected back into the accommodating space S to enhance the brightness above the OLED structure 200 .

In some implementations, as shown in FIG. 1 , the pixel definition structure 400 may include a transparent body 410 and a reflector 420 . The transparent body 410 is located on the driving substrate 100 and defines the accommodating space S, and contacts the OLED structure 200 and the covering electrode 300 . The transparent body 410 is against the protective cover 500 . The reflector 420 is located on the driving substrate 100 and covered by the transparent body 410 . In this way, when the light totally reflected on the upper surface of the cover electrode 300 and/or the side light emitted by the OLED structure 200 reaches the pixel definition structure 400 , these light rays can enter the light-transmitting body 410 and reach the reflector 420 . When the light reaches the reflector 420 , the reflector 420 can reflect the light back into the accommodating space S to increase the brightness above the OLED structure 200 .

In some embodiments, the shortest distance from the reflector 420 to the protective cover 500 is smaller than the shortest distance from the OLED structure 200 to the protective cover 500 . In other words, the height of the highest position P1 of the reflector 420 is higher than the height of the highest position P2 of the OLED structure 200 . In this way, when the light totally reflected on the upper surface of the covering electrode 300 and/or the side light emitted by the OLED structure 200 enters the pixel definition structure 400 , it can be preferably ensured that the light can encounter the reflector 420 , and is reflected by the reflector 420 . It should be understood that the highest position P1 of the reflector 420 is the position on the reflector 420 closest to the protective cover 500 . The highest position P2 of the OLED structure 200 is the position closest to the protective cover 500 on the OLED structure 200 .

In some embodiments, the reflector 420 has a thickness T1, and the OLED structure 200 has a thickness T2. The thickness T1 of the reflector 420 is greater than the thickness T2 of the OLED structure 200 . In this way, when the light totally reflected on the upper surface of the covering electrode 300 and/or the side light emitted by the OLED structure 200 enters the pixel definition structure 400 , it can be preferably ensured that the light can encounter the reflector 420 , and is reflected by the reflector 420 .

In some embodiments, the reflector 420 is tapered along the direction toward the protective cover 500 , which is beneficial to reflect the side light emitted by the OLED structure 200 toward the protective cover 500 to improve the OLED structure. Brightness above 200. For example, the reflector 420 can be a truncated cone structure with opposite top surface 421 and bottom surface 422 . The bottom surface 422 is closer to the driving substrate 100 than the top surface 421 , that is, the top surface 421 is closer to the protective cover 500 than the bottom surface 422 . The area of the bottom surface 422 is greater than that of the top surface 421 , so that the reflector 420 is tapered along the direction toward the protective cover 500 .

In some embodiments, the fabrication method of the pixel definition structure 400 is as follows. Firstly, the material of the reflector 420 can be deposited on the driving substrate 100 to form the reflector 420 . Then, the material of the transparent body 410 can be deposited on the driving substrate 100 and the reflector 420 to form the transparent body 410 . In some embodiments, the above-mentioned deposition methods may include physical vapor deposition (such as evaporation or sputtering), chemical vapor deposition, or wet printing coating deposition, but the present invention is not limited thereto.

In some implementations, as shown in FIG. 1 , the OLED display device further includes a polarizer 600 . The reflector 420 of the pixel definition structure 400 is located between the polarizer 600 and the driving substrate 100 . Further, the polarizer 600 is disposed on the protective cover 500 . In this way, the polarizer 600 can polarize ambient light and then enter the pixel definition structure 400 , so it is less likely to be reflected by the reflector 420 . In this way, the polarizer 600 can reduce the reflection of ambient light, so as to improve the visual taste of the OLED display device. For example, the polarizer 600 can be a circular polarizer, but the invention is not limited thereto.

In some implementations, the OLED display device may further include a frame body 700 . The frame body 700 is against between the driving substrate 100 and the protective cover 500 , and the frame body 700 is located outside the pixel defining structure 400 . In other words, box 700 defines structure 400 around pixels. In this way, the frame body 700 can further prevent moisture and/or oxygen from penetrating into the pixel defining structure 400 . In some embodiments, the frame body 700 can be a sealant, but the present invention is not limited thereto.

In some implementations, the driving substrate 100 may be a thin film transistor array (TFT array) substrate. Further, as shown in FIG. 1 , the driving substrate 100 may include a carrier substrate 120 , a gate electrode 130 , a source electrode 140 , a drain electrode 150 , and an active layer 160 . The gate electrode 130 , the source electrode 140 and the drain electrode 150 are located above the carrier substrate 120 and are carried by the carrier substrate 120 . The gate electrode 130 , the source electrode 140 and the drain electrode 150 are separated from each other. The active layer 160 covers the gate electrode 130 . The source electrode 140 covers a part of the active layer 160 , and the drain electrode 150 covers another part of the active layer 160 . In this way, the gate electrode 130 , the source electrode 140 , the drain electrode 150 , and the active layer 160 can jointly form a thin film transistor. The pixel electrode 110 can be electrically connected to the drain electrode 150, so the OLED structure 200 can be controlled by a thin film transistor. In some embodiments, the pixel electrode 110 may be electrically connected to the source electrode 140 instead of electrically connected to the drain electrode 150 .

In some embodiments, the driving substrate 100 includes a plurality of thin film transistors and corresponding plurality of pixel electrodes 110 , and the number of the OLED structures 200 and the cover electrodes 300 is the same as that of the pixel electrodes 110 . In this way, the organic light emitting diode display device can use a plurality of organic light emitting diode structures 200 as a plurality of pixels to facilitate image display.

In some embodiments, the OLED structure 200 may include a hole injection layer (Hole Injection Layer; HIL), a hole transport layer (Hole Transporting Layer; HTL), and an electron blocking layer (Electron Blocking Layer; EBL) stacked in sequence. , a light emitting layer, a hole blocking layer (Hole Blocking Layer; HBL), an electron transporting layer (Electron Transporting Layer; ETL), and an electron injection layer (Electron Injection Layer; EIL). In some embodiments, corresponding organic materials can be used to make the light emitting layer according to the color (such as red, green or blue) required by the pixel. In some embodiments, the pixel electrode 110 can be electrically connected to the hole injection layer, and the covering electrode 300 can be electrically connected to the electron injection layer. In some embodiments, the pixel electrode 110 can be electrically connected to the electron injection layer. The cover electrode 300 can be electrically connected to the hole injection layer.

In some embodiments, the covering electrode 300 can be made of metal or metal oxide, such as aluminum, silver, magnesium-silver alloy, indium tin oxide (ITO) or indium zinc oxide (IZO). It should be understood that when the material of the covering electrode 300 is opaque metal, its size can be small enough to be invisible to the naked eye. For example, the material of the covering electrode 300 can be nano-silver, although it is an opaque material, its nanoscale size makes it invisible to the naked eye. In this way, the user can still see the light covering the OLED structure 200 under the electrode 300 .

FIG. 2 is a schematic cross-sectional view of an OLED display device according to another embodiment of the present invention. As shown in FIG. 2 , the main difference between this embodiment and the foregoing embodiments is that the pixel definition structure 400 a is different from the foregoing pixel definition structure 400 . Specifically, the pixel definition structure 400a includes a transparent body 410 , a reflector 420 and an opaque body 430 . The transparent body 410 is located on the driving substrate 100 . The transparent body 410 defines the accommodation space S, and contacts the OLED structure 200 and the covering electrode 300 . The transparent body 410 is against the protective cover 500 . The reflector 420 is located on the driving substrate 100 . At least part of the opaque body 430 is disposed on the reflector 420 to be located between the reflector 420 and the protective cover 500 . In this way, the part of the opaque body 430 can prevent the ambient light passing through the protective cover 500 from encountering the reflector 420 , thus preventing the reflector 420 from reflecting the ambient light. Since the opaque body 430 can reduce the reflection of ambient light, the polarizer 600 shown in FIG. 1 is unnecessary in this embodiment. In other embodiments, the OLED display device may also include the opaque body 430 and the polarizer 600 to better prevent reflection of ambient light. In some embodiments, the opaque body 430 can absorb light but not reflect light, so as to avoid reflecting ambient light.

In some embodiments, the fabrication method of the pixel definition structure 400a is as follows. First, the material of the reflector 420 is deposited on the driving substrate 100 to form the reflector 420 . Next, the material of the opaque body 430 is deposited on the driving substrate 100 and the reflector 420 to form the opaque body 430 . Finally, the material of the transparent body 410 is deposited on the opaque body 430 and the reflector 420 to form the transparent body 410 . In some embodiments, the above-mentioned deposition methods may include physical vapor deposition (such as evaporation or sputtering), chemical vapor deposition, or wet printing coating deposition, but the present invention is not limited thereto.

Other technical features of this embodiment are similar to those of the embodiment shown in FIG. 1 , so they will not be described repeatedly.

FIG. 3 is a schematic cross-sectional view of an OLED display device according to another embodiment of the present invention. As shown in FIG. 3 , the main difference between this embodiment and the previous embodiments is that this embodiment includes a light-transmitting filling body 800 . The transparent filler 800 is filled in the gap between the cover electrode 300 and the protective cover 500 , which can prevent the light emitted from the OLED structure 200 from being totally reflected on the upper surface of the cover electrode 300 . For example, the difference in refractive index between the material of the light-transmitting filler 800 and the material covering the electrode 300 can be smaller than the difference in refractive index between the material covering the electrode 300 and the gas (such as nitrogen or air), so as to increase the threshold required for total reflection. Angle, and reduce the incidence of total reflection. In some implementations, the refractive index of the material of the transparent filler 800 may be greater than or equal to the refractive index of the material covering the electrode 300 , so as to prevent total reflection more effectively. For example, the light-transmitting filler 800 can be an optical adhesive (Optical Clear Adhesive; OCA) or an optical resin (Optical Clear Resin; OCR) or a hygroscopic material with a high refractive index, which can further improve the reliability of the element, but this The invention is not limited thereto.

In this embodiment, the pixel definition structure 400b can be an opaque structure or a reflective structure. In other words, the material of the pixel defining structure 400b can be opaque material or reflective material. In some implementations, the pixel definition structure 400b is fabricated by depositing opaque material and reflective material on the driving substrate 100 . The above-mentioned deposition methods may include physical vapor deposition (such as evaporation or sputtering), chemical vapor deposition, or wet printing coating deposition, but the present invention is not limited thereto.

Other technical features of this embodiment are similar to those of the embodiment shown in FIG. 1 , so they will not be described repeatedly.

Although the present invention has been disclosed above in terms of implementation, it is not intended to limit the present invention. Any skilled person can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection should be based on the scope defined by the appended claims.

Claims (7)

1. An organic light emitting diode display device, characterized in that it comprises: A driving substrate, including at least one pixel electrode; at least one organic light emitting diode structure disposed on the pixel electrode; at least one covering electrode, the organic light emitting diode structure is located between the pixel electrode and the covering electrode; At least one pixel defining structure is disposed on the driving substrate, the pixel defining structure has an accommodating space, and the organic light emitting diode structure and the cover electrode are located in the accommodating space; and a protective cover covering the driving substrate, the organic light emitting diode structure, the cover electrode and the pixel definition structure, wherein the pixel definition structure is against the protection cover; Wherein, the pixel definition structure is used to reflect the light emitted by the organic light emitting diode structure back into the accommodating space, and the pixel definition structure includes: A light-transmitting body is located on the driving substrate and defines the accommodating space; a reflector located on the drive substrate; and An opaque body, at least part of the opaque body is arranged on the reflector so as to be located between the reflector and the protective cover. 2 . The OLED display device according to claim 1 , wherein the shortest distance from the reflector to the protective cover is smaller than the shortest distance from the OLED structure to the protective cover. 3. The organic light emitting diode display device according to claim 1, further comprising a polarizer disposed on the protective cover, and the reflector of the pixel definition structure is located between the polarizer and the driving substrate between. 4. The organic light emitting diode display device according to claim 1, further comprising a light-transmitting filling body, the light-transmitting filling body is filled in a gap between the covering electrode and the protective cover, and The difference in refractive index between the material of the light-transmitting filler and the material covering the electrode is smaller than the difference in refractive index between the material of the covering electrode and the gas, wherein the gas is nitrogen or air. 5. The organic light emitting diode display device according to claim 1, further comprising a light-transmitting filling body, the light-transmitting filling body is filled in a gap between the covering electrode and the protective cover, wherein The refractive index of the material of the transparent filling body is greater than or equal to the refractive index of the material of the covering electrode. 6 . The organic light emitting diode display device according to claim 1 , wherein the pixel defining structure is an opaque material structure or a reflective material structure. 7 . The organic light emitting diode display device according to claim 1 , further comprising a frame, abutted between the driving substrate and the protective cover, and located outside the pixel defining structure.