Flexible OLED display module

Abstract

The invention relates to a flexible OLED display module. Provided is a flexible OLED display module that can be repeatedly flexed and has a low radius of curvature. According to one embodiment, a flexible OLED display module may include a first stack having a substrate, a backplane disposed on the substrate, and an organic electroluminescent layer formed on the backplane. The flexible OLED display module may further include a second stack having a cap layer and a polarizer deposited on the cap layer. The first stack is laminated with the second stack.

Description

[0001] This application is a divisional application of the application with the filing date of September 26, 2017, application number 201710883678.2, and invention name "Flexible OLED Display Module".

[0002] This patent application claims the priority of U.S. Provisional Patent Application No. 62 / 400,339, filed on September 27, 2016, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to a flexible organic light emitting diode (OLED) display module. Background Art

[0004] For various reasons, optoelectronic devices using organic materials have become increasingly popular. Many of the materials used to fabricate such devices are relatively inexpensive, so organic optoelectronic devices have the potential for cost advantages over inorganic devices. Additionally, the inherent properties of organic materials, such as their flexibility, can make them more suitable for certain applications, such as fabrication on flexible substrates. Examples of organic optoelectronic devices include organic light emitting diodes / devices (OLEDs), organic phototransistors, organic photovoltaic cells, and organic photodetectors. For OLEDs, organic materials can have performance advantages over conventional materials. For example, the wavelength of light emitted by an organic emissive layer can generally be easily adjusted with appropriate dopants.

[0005] OLEDs utilize organic thin films that emit light when a voltage is applied across the device. OLEDs are becoming an increasingly attractive technology for applications such as flat panel displays, lighting, and backlighting. Several OLED materials and configurations are described in U.S. Patent Nos. 5,844,363, 6,303,238, and 5,707,745, which are incorporated herein by reference in their entirety.

[0006] One application of phosphorescent emissive molecules is full-color displays. Industry standards for such displays require pixels that are suitable for emitting specific colors (referred to as "saturated" colors). Specifically, these standards require saturated red, green, and blue pixels. Alternatively, an OLED can be designed to emit white light. In conventional liquid crystal displays, absorption filters are used to filter the emission from a white backlight to produce red, green, and blue emissions. The same technique can also be used for OLEDs. White OLEDs can be single EML devices or stacked structures. Color can be measured using CIE coordinates well-known in the art.

[0007] An example of a green emissive molecule is tris(2-phenylpyridine) iridium, denoted as Ir(ppy) 3 , which has the following structure:

[0008]

[0009] In this figure and the figures below, we depict the coordination bond of nitrogen with a metal (here Ir) in a straight line form.

[0010] As used herein, the term “organic” includes polymeric materials and small molecule organic materials that can be used to fabricate organic optoelectronic devices. “Small molecule” refers to any organic material that is not a polymer, and a “small molecule” can actually be quite large. In some cases, small molecules can include repeating units. For example, the use of a long-chain alkyl as a substituent does not remove a molecule from the “small molecule” category. Small molecules can also be incorporated into polymers, such as as pendant groups on the polymer backbone or as part of the backbone. Small molecules can also serve as the core portion of a dendrimer, which consists of a series of chemical shells built on the core portion. The core portion of a dendrimer can be a fluorescent or phosphorescent small molecule emitter. Dendrimers can be “small molecules”, and all dendrimers currently used in the OLED field are considered to be small molecules.

[0011] As used herein, “top” means furthest from the substrate, and “bottom” means closest to the substrate. In the case where a first layer is described as being “disposed on” a second layer “above”, the first layer is disposed further from the substrate. Unless it is specified that the first layer “contacts” the second layer, there can be other layers between the first and second layers. For example, even if there are various organic layers between the cathode and the anode, the cathode can still be described as being “disposed on” the anode “above”.

[0012] As used herein, “solution processable” means capable of being dissolved, dispersed, or transported in a liquid medium in the form of a solution or suspension and / or deposited from a liquid medium.

[0013] When a ligand is considered to directly contribute to the photosensitive properties of an emissive material, the ligand can be referred to as “photosensitive”. When a ligand is not considered to contribute to the photosensitive properties of an emissive material, the ligand can be referred to as “auxiliary”, but an auxiliary ligand can modify the properties of a photosensitive ligand.

[0014] As used herein, and as would be generally understood by one of ordinary skill in the art, if the first energy level is closer to the vacuum energy level, then the first "highest occupied molecular orbital" (HOMO) or "lowest unoccupied molecular orbital" (LUMO) energy level is "greater than" or "higher than" the second HOMO or LUMO energy level. Since the ionization potential (IP) is measured as a negative energy relative to the vacuum energy level, a higher HOMO energy level corresponds to an IP with a smaller absolute value (a less negative IP). Similarly, a higher LUMO energy level corresponds to an electron affinity (EA) with a smaller absolute value (a less negative EA). On a conventional energy level diagram with the vacuum energy level at the top, the LUMO energy level of a material is higher than the HOMO energy level of the same material. A "higher" HOMO or LUMO energy level appears closer to the top of this diagram than a "lower" HOMO or LUMO energy level.

[0015] As used herein, and as would be generally understood by one of ordinary skill in the art, if the first work function has a higher absolute value, then the first work function is "greater than" or "higher than" the second work function. Since the work function is typically measured as a negative number relative to the vacuum energy level, this means that a "higher" work function is more negative. On a conventional energy level diagram with the vacuum energy level at the top, a "higher" work function is depicted as being farther from the vacuum energy level in the downward direction. Thus, the definitions of HOMO and LUMO energy levels follow different rules than the work function.

[0016] More details regarding OLEDs and the definitions described above can be found in U.S. Patent No. 7,279,704, which is hereby incorporated by reference in its entirety.

[0017] OLED displays are commonly used in mobile devices, smart watches, computer monitors, and televisions. OLED displays can be active matrix organic light emitting diodes (AMOLEDs) or passive matrix organic light emitting diodes (PMOLEDs). Reliable and flexible OLED display modules are needed to fabricate devices with novel designs. It is currently difficult to fabricate a flexible OLED display module that can be flexed (radius of curvature) to less than 1 mm in a reliable and repeatable manner. Most flexible OLED module designs are too thick for repeated flexing. For reliable and repeated flexing, a flexible OLED display module should have a thickness of about 10% of the required radius of curvature for flexing or a thickness of about 100 μm. Current fabrication of OLED display modules results in modules that are hundreds of microns too thick and leads to poor display flexibility. SUMMARY OF THE INVENTION

[0018] Provided is a flexible OLED display module that can be repeatedly flexed and has a low radius of curvature.

[0019] According to one embodiment, a flexible OLED display module may include a first stack having a substrate, a backplane disposed on the substrate, and an organic electroluminescent layer formed on the backplane. The flexible OLED display module may further include a second stack having a cover layer and a polarizer deposited on the cover layer. The first stack and the second stack are laminated.

[0020] In one embodiment of the present invention disclosed herein, a flexible OLED display module may include a touch panel disposed in the neutral plane of the flexible OLED display module.

[0021] In one embodiment of the present invention disclosed herein, the deposited polarizer may be a circular polarizer including a linear polarizer and a quarter-wave retarder.

[0022] According to another embodiment, a method of manufacturing a flexible OLED display module is provided. The method may include providing a substrate. A backplane is formed on the substrate. An organic electroluminescent layer may be formed on the backplane. The substrate, the backplane, and the organic electroluminescent layer form a first stack. The method may further include providing a cover. A polarizing film may be deposited on the cover to form a second stack. The second stack may be dried and then the second stack and the first stack may be laminated.

[0023] Some embodiments of the present invention are illustrated by the following:

[0024] Item 1. A flexible OLED display module, comprising:

[0025] A first stack, comprising:

[0026] A substrate,

[0027] A backplane disposed on the substrate, and

[0028] An organic electroluminescent layer formed on the backplane; and

[0029] A second stack laminated with the first stack, comprising:

[0030] A cover layer, and

[0031] A deposited polarizer formed on the cover layer.

[0032] Item 2. The flexible OLED display module according to Item 1, wherein the thickness of the flexible OLED display module is less than 150 μm.

[0033] Item 3. The flexible OLED display module according to Item 2, wherein the thickness of the first stack is less than 60 μm, and the thickness of the second stack is less than 60 μm.

[0034] Item 4. The flexible OLED display module according to Item 1, wherein the laminate between the first stack and the second stack is selected from one of the following: a pressure-sensitive adhesive, an epoxy resin, and an optically clear adhesive.

[0035] Item 5. The flexible OLED display module according to Item 1, further comprising a touch panel disposed in one of the first stack and the second stack.

[0036] Item 6. The flexible OLED display module according to Item 5, wherein the touch panel is disposed within 10 μm of the neutral plane of the flexible OLED display module.

[0037] Item 7. The flexible OLED display module according to Item 1, wherein the deposited polarizer is a deposited circular polarizer, which comprises a deposited linear polarizer and a deposited quarter-wave retarder.

[0038] Item 8. The flexible OLED display module according to Item 1, further comprising a encapsulation layer, and wherein the encapsulation layer is provided on at least one of the first stack and the second stack.

[0039] Item 9. The flexible OLED display module according to Item 1, wherein the second stack further comprises a color filter.

[0040] Item 10. The flexible OLED display module according to Item 1, wherein the flexible OLED display module is capable of having a radius of curvature of less than 2 mm. Description of the Drawings

[0041] Figure 1 Discloses an organic light-emitting device.

[0042] Figure 2 Discloses an inverted organic light-emitting device without an independent electron transport layer.

[0043] Figure 3A Discloses a flexible OLED display module according to an embodiment of the present invention.

[0044] Figure 3B Discloses a flexible OLED display module according to another embodiment of the present invention. Detailed Description

[0045] Generally, an OLED includes at least one organic layer disposed between and electrically connected to an anode and a cathode. When a current is applied, the anode injects holes and the cathode injects electrons into the organic layer. The injected holes and electrons each migrate toward the electrode of opposite charge. When an electron and a hole are located on the same molecule, an "exciton" is formed, which is a localized electron-hole pair with an excited energy state. When the exciton relaxes through a light-emission mechanism, light is emitted. In some cases, the exciton can be localized on an excimer or an exciplex. Non-radiative mechanisms, such as thermal relaxation, may also occur but are generally considered undesirable.

[0046] Initial OLEDs used emissive molecules that emit light from singlet states ("fluorescence"), as disclosed, for example, in U.S. Patent No. 4,769,292, which is incorporated herein by reference in its entirety. Fluorescent emission typically occurs within a time frame of less than 10 nanoseconds.

[0047] Recently, OLEDs with emissive materials that emit light from triplet states ("phosphorescence") have been demonstrated. Baldo et al., "Highly Efficient Phosphorescent Emission from Organic Electroluminescent Devices", Nature, Vol. 395, 151 - 154, 1998 ("Baldo-I"); and Baldo et al., "Very high-efficiency green organic light-emitting devices based on electrophosphorescence", Appl. Phys. Lett., Vol. 75, No. 3, pp. 4 - 6 (1999) ("Baldo-II"), which are incorporated herein by reference in their entirety. Phosphorescence is described in more detail in columns 5 - 6 of U.S. Patent No. 7,279,704, which is incorporated by reference.

[0048] Figure 1An organic light emitting device 100 is shown. The figures are not necessarily drawn to scale. Device 100 may include a substrate 110, an anode 115, a hole injection layer 120, a hole transport layer 125, an electron blocking layer 130, an emission layer 135, a hole blocking layer 140, an electron transport layer 145, an electron injection layer 150, a protection layer 155, a cathode 160, and a blocking layer 170. Cathode 160 may be a composite cathode having a first conductive layer 162 and a second conductive layer 164. Device 100 may be fabricated by depositing the layers in sequence. The properties and functions of these various layers and exemplary materials are described in more detail in columns 6-10 of US 7,279,704, which is incorporated herein by reference.

[0049] More examples of each of these layers may be obtained. For example, a flexible and transparent substrate-anode combination is disclosed in US Patent No. 5,844,363, which is incorporated herein by reference in its entirety. An example of a p-doped hole transport layer is m-MTDATA doped with F 4 -TCNQ at a molar ratio of 50:1, as disclosed in US Patent Application Publication No. 2003 / 0230980, which is incorporated herein by reference in its entirety. Examples of light emitting and host materials are disclosed in US Patent No. 6,303,238 to Thompson et al., which is incorporated herein by reference in its entirety. An example of an n-doped electron transport layer is BPhen doped with Li at a molar ratio of 1:1, as disclosed in US Patent Application Publication No. 2003 / 0230980, which is incorporated herein by reference in its entirety. US Patents Nos. 5,703,436 and 5,707,745, which are incorporated herein by reference in their entireties, disclose examples of cathodes including a composite cathode having a thin layer of metal (such as Mg:Ag) with an overlying transparent, conductive, sputter-deposited ITO layer. The theory and use of the blocking layer are described in more detail in US Patent No. 6,097,147 and US Patent Application Publication No. 2003 / 0230980, which are incorporated herein by reference in their entireties. Examples of the injection layer are provided in US Patent Application Publication No. 2004 / 0174116, which is incorporated herein by reference in its entirety. A description of the protection layer may be found in US Patent Application Publication No. 2004 / 0174116, which is incorporated herein by reference in its entirety.

[0050] Figure 2Disclosed is an inverted OLED 200. The device includes a substrate 210, a cathode 215, an emissive layer 220, a hole transport layer 225, and an anode 230. The device 200 can be fabricated by depositing the layers in sequence. Since the most common OLED configuration has a cathode disposed above the anode, and the device 200 has a cathode 215 disposed under the anode 230, the device 200 can be referred to as an "inverted" OLED. Materials similar to those described with respect to device 100 can be used in the corresponding layers of device 200. Figure 2 An example is provided of how some layers can be omitted from the structure of device 100.

[0051] Figure 1 and 2 The simple layered structure illustrated in and is provided by way of non-limiting example, and it should be understood that embodiments of the present invention can be used in conjunction with a variety of other structures. The specific materials and structures described are exemplary in nature, and other materials and structures can be used. Functional OLEDs can be obtained by combining the various layers in different ways, or various layers can be omitted entirely based on design, performance, and cost factors. Other layers not specifically described can also be included. Materials other than those specifically described can be used. Although many of the examples provided herein describe the various layers as including a single material, it should be understood that combinations of materials can be used, such as a mixture of a host and a dopant, or more generally, mixtures. In addition, the layers can have various sub-layers. The names given to the various layers herein are not intended to be strictly limiting. For example, in device 200, the hole transport layer 225 transports holes and injects holes into the emissive layer 220, and can be described as a hole transport layer or a hole injection layer. In one embodiment, an OLED can be described as having an "organic layer" disposed between the cathode and the anode. This organic layer can comprise a single layer, or can further comprise multiple layers of different organic materials such as, for example, with respect to Figure 1 and 2 described.

[0052] Structures and materials not specifically described can also be used, such as OLEDs (PLEDs) comprising polymeric materials, as disclosed, for example, in U.S. Patent No. 5,247,190 to Friend et al., which is incorporated herein by reference in its entirety. By way of another example, an OLED having a single organic layer can be used. OLEDs can be stacked, for example, as described in U.S. Patent No. 5,707,745 to Forrest et al., which is incorporated herein by reference in its entirety. The OLED structure can deviate from Figure 1 and 2The simple layered structure described therein. For example, the substrate can include angled reflective surfaces to improve out-coupling, such as the mesa structure described in U.S. Patent No. 6,091,195 to Forrest et al., and / or the pit structure described in U.S. Patent No. 5,834,893 to Bulovic et al., which patents are incorporated herein by reference in their entirety.

[0053] Unless otherwise specified, any suitable method can be used to deposit any of the layers of the various embodiments. For organic layers, preferred methods include thermal evaporation, inkjet (as described in U.S. Patents Nos. 6,013,982 and 6,087,196, which are incorporated herein by reference in their entirety), organic vapor phase deposition (OVPD) (as described in U.S. Patent No. 6,337,102 to Forrest et al., which is incorporated herein by reference in its entirety), and deposition by organic vapor jet printing (OVJP) (as described in U.S. Patent No. 7,431,968, which is incorporated herein by reference in its entirety). Other suitable deposition methods include spin coating and other solution-based processes. Solution-based processes are preferably carried out in nitrogen or an inert atmosphere. For other layers, preferred methods include thermal evaporation. Preferred patterning methods include deposition through a mask, cold welding (as described in U.S. Patents Nos. 6,294,398 and 6,468,819, which are incorporated herein by reference in their entirety), and patterning associated with some of the deposition methods such as inkjet and OVJD. Other methods can also be used. The materials to be deposited can be modified to be suitable for the specific deposition method. For example, branched or unbranched substituents, preferably containing at least 3 carbons, such as alkyl and aryl groups, can be used in small molecules to enhance their ability to withstand solution processing. Substituents having 20 or more carbons can be used, and a range of 3 to 20 carbons is preferred. Materials having an asymmetric structure can have better solution processability than materials having a symmetric structure because asymmetric materials may have a lower tendency to recrystallize. Dendrimer substituents can be used to enhance the ability of small molecules to withstand solution processing.

[0054] Devices fabricated in accordance with embodiments of the present invention may further optionally include a barrier layer. One use of the barrier layer is to protect the electrodes and organic layers from damage by harmful substances in an environment that includes moisture, vapor, and / or gases, among others. The barrier layer may be deposited on the substrate, on the electrodes, under the substrate, under the electrodes, beside the substrate, beside the electrodes, or on any other part of the device, including the edges. The barrier layer may include a single layer or multiple layers. The barrier layer may be formed by various known chemical vapor deposition techniques and may include compositions having a single phase and compositions having multiple phases. Any suitable material or combination of materials may be used for the barrier layer. The barrier layer may include inorganic compounds, organic compounds, or both. A preferred barrier layer includes a mixture of a polymeric material and a non-polymeric material, as described in U.S. Patent No. 7,968,146, PCT Patent Application Nos. PCT / US2007 / 023098 and PCT / US2009 / 042829, which are incorporated herein by reference in their entirety. For the purposes of being considered a "mixture," the foregoing polymeric material and non-polymeric material that make up the barrier layer should be deposited under the same reaction conditions and / or simultaneously deposited. The weight ratio of the polymeric material to the non-polymeric material may range from 95:5 to 5:95. The polymeric material and the non-polymeric material may be produced from the same precursor material. In one example, the mixture of the polymeric material and the non-polymeric material consists essentially of polymeric silicon and inorganic silicon.

[0055] Devices fabricated in accordance with embodiments of the present invention can be incorporated into a wide variety of electronic component modules (or units), which can in turn be incorporated into a variety of electronic products or intermediate components. Examples of such electronic products or intermediate components include display screens, lighting devices (such as discrete light source devices or lighting panels) that can be utilized by end-user product manufacturers, and the like. The electronic component modules can optionally include driving electronics and / or a power source. Devices fabricated in accordance with embodiments of the present invention can be incorporated into a wide variety of consumer products that have one or more electronic component modules (or units) incorporated therein. The consumer products should include any kind of product that includes one or more light sources and / or one or more of a certain type of visual display. Some examples of the consumer products include flat panel displays, computer monitors, medical monitors, televisions, billboards, lights for interior or exterior lighting and / or signaling, head-up displays, fully or partially transparent displays, flexible displays, laser printers, telephones, cellular phones, tablet computers, phablets, personal digital assistants (PDAs), wearable devices, laptop computers, digital cameras, video cameras, viewfinders, microdisplays, 3-D displays, vehicles, large area walls, theater or stadium screens or signs. A variety of control mechanisms can be used to control the devices fabricated in accordance with the present invention, including passive matrix and active matrix. It is intended that many of the devices be used in a temperature range that is comfortable for humans, such as from 18 degrees Celsius to 30 degrees Celsius, and more preferably at room temperature (20 - 25 degrees Celsius), but they can be used outside of this temperature range (e.g., from -40 degrees Celsius to +80 degrees Celsius).

[0056] The materials and structures described herein can be applied to devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors can employ the materials and structures. More generally, organic devices such as organic transistors can employ the materials and structures.

[0057] Figure 3A and 3BDisclosed is a flexible OLED display module 301 according to an embodiment of the present invention. Additionally, the figures are not necessarily drawn to scale but are for illustrative purposes. The flexible OLED display module 301 includes a substrate, such as an active substrate 310. An active or passive backplane 312 and an organic electroluminescent layer 313 may be formed on the active substrate 310. The OLED display may be an active matrix organic light emitting diode (AMOLED) or a passive matrix organic light emitting diode (PMOLED). The flexible OLED display module 301 may also include a second substrate opposite to the active substrate 310, such as a cover 318. The substrate may be a plastic substrate with a glass transition temperature below 200°C. The substrate may also be a thin metal foil or other suitable material. The flexible OLED display module 301 may further include encapsulation bodies 311, 314, a polarizer 317, a color filter (not shown), a touch panel 315, and sufficient reinforcement (top protection cover) to ensure that the display is not damaged during normal use. For descriptive purposes, the substrate and its films or components are referred to as stacks. For example, the first substrate may include the active substrate 310, the encapsulation bodies 311, 314, the backplane 312, and the organic electroluminescent layer 313. The second stack may include the cover 318, the polarizer 317, and the color filter. Although the first and second stacks have been described above, it should be understood that the layers and components may be arranged in multiple orders within the stacks, and both the first and second stacks may contain additional layers and components other than the layers and components described. The touch panel 315 may be disposed in either the first or second stack. The neutral plane for bending should be within the region bounded by the two stacks. The touch panel 315 should be disposed within 10 μm of the neutral plane. The first stack and the second stack may be laminated together using an optically clear adhesive (OCA). For visual description, Figure 3A and 3B disclosed is a laminated layer 316. Other lamination methods, such as pressure-sensitive adhesives, epoxy resins, or other known and suitable lamination techniques, may be used. The laminated layer 316 may laminate the touch panel 315 to the first stack or the second stack. It should be understood that the flexible OLED display module 301 may not include the touch panel 315. The thickness of each of the first and second stacks is less than 60 μm, preferably less than 50 μm. The thickness of the OLED display module 301 is less than 150 μm, preferably less than 100 μm.

[0058] As disclosed above and Figure 3A and 3BAs shown, the touch panel 315 can be disposed in either the first or second stack using standard techniques. Generally, the touch panel 315 is the least flexible component in the flexible OLED display module 301. To minimize the problem of repeated flexure of the touch panel 315, the touch panel 315 should be disposed close to the neutral plane. The touch panel should be disposed within 10 μm of the neutral plane. As Figure 3A and 3B shown, the touch panel 315 is placed on the active substrate 310 (first stack) or the cover 318 (second stack), but in each case, is placed as the top layer closest to the lamination plane.

[0059] The polarizer 317 can be a circular polarizer, which can be composed of two optical reagents, a linear polarizer 317A and a quarter-wave retarder 317B, or a birefringent material. Lyotropic liquid crystals can be used as the source of the birefringent and linear polarizer 317A. However, these materials contain water and other moisture. Therefore, the polarizer 317 should be cured and dried before use. In other words, the polarizer 317 is deposited on the cover 318, the stack is dried, and then the two stacks are laminated together. Drying ensures that all moisture is removed from the final flexible OLED display module 301, increasing the service life of the flexible OLED display module 301.

[0060] The flexible OLED display module 301 may be capable of operating at a sunlight-readable brightness value (e.g., 700 cd / m 2 ). Additionally, according to an embodiment of the present invention, the flexible OLED display module 301 may not experience an operating temperature increase of more than 26 °C. The operating temperature increase can be the temperature increase attributable to the heat generated by the display. The display can generate heat due to factors such as (but not limited to) the following: friction, vibration, current, energy conversion, etc. For example, the flexible OLED display module 301 may experience an operating temperature rise due to inefficient device operation, in which a portion of the energy is converted into heat rather than generating light. The temperature increase due to environmental conditions may not be considered in the calculation of the operating temperature increase. Such environmental conditions can include (but not limited to) body heat, sunlight, weather conditions, external air flow, external flames, etc. For example, if the display is operated at an initial ambient temperature of 25 °C and the ambient temperature is increased to 30 °C within one hour of operation, then the 5 °C increase in the ambient temperature should not be a factor in the operating temperature calculation. In the same example, if the total temperature of the display increases to 50 °C after one hour of operation, then the operating temperature increase is 20 °C (50 °C minus 30 °C). Other information regarding brightness values is disclosed, for example, in U.S. Patent No. 8,766,531, which is incorporated herein by reference in its entirety.

[0061] As previously described, one or more layers of the various embodiments of the flexible OLED display module 301 for the present invention can be fabricated using a plurality of techniques. After fabricating a first stack that can include an active substrate 310, encapsulation bodies 311, 314, a backplane 312, and OLED pixels 313, a second stack is fabricated by depositing a polarizer 317 on a cover 318. The polarizer 317 can be a circular polarizer formed from a linear polarizer 317A and a quarter-wave retarder 317B. The second stack can also include a color filter. A touch panel 315 is formed in either the first stack or the second stack. The touch panel 315 is disposed close to the middle of the two stacks, i.e., close to the neutral plane. Generally, the touch panel 315 is disposed within 10 μm of the neutral plane of the flexible OLED display module 301. Before laminating the first and second stacks together and before removing all trace amounts of moisture from the polarizer 317, the stacks are sufficiently dried. After the drying process, the first stack is laminated with the second stack.

[0062] It should be understood that the various embodiments described herein are by way of example only and are not intended to limit the scope of the present invention. For example, many of the materials and structures described herein can be replaced with other materials and structures without departing from the spirit of the present invention. The present invention as claimed can thus include variations of the specific examples and preferred embodiments described herein, as will be apparent to those skilled in the art. It should be understood that the various theories as to why the present invention works are not intended to be limiting.

Claims

1. A flexible OLED display module, comprising: A first stack, comprising: A substrate, A backplane disposed on the substrate, and An organic electroluminescent layer formed on the backplane; and A second stack laminated with the first stack, comprising: A cover layer, and A deposited polarizer formed on the cover layer, Wherein the substrate of the first stack and the cover layer of the second stack are laminated to be on opposite sides of each other, Wherein the first stack further comprises a package and a touch panel, the package is disposed on the organic electroluminescent layer, and the touch panel is directly disposed on the package, Wherein the backplane only includes TFT devices and lines, and Wherein the thickness of the flexible OLED display module is less than 150 μm.

2. A flexible OLED display module, comprising: A first stack, comprising: A substrate, A backplane disposed on the substrate, and An organic electroluminescent layer formed on the backplane; and A second stack laminated with the first stack, comprising: A cover layer, and A deposited polarizer formed on the cover layer, Wherein the substrate of the first stack and the cover layer of the second stack are laminated to be on opposite sides of each other, Wherein the first stack further comprises a package and a touch panel, the package is disposed on the organic electroluminescent layer, and the touch panel is directly disposed on the package, Wherein the backplane only includes TFT devices and lines, and Wherein the thickness of the first stack is less than 60 μm, and the thickness of the second stack is less than 60 μm.

3. A flexible OLED display module, comprising: A first stack, comprising: A substrate, A backplane disposed on the substrate, and An organic electroluminescent layer formed on the backplane; and A second stack laminated with the first stack, comprising: A cover layer, and A deposited polarizer formed on the cover layer, Wherein the substrate of the first stack and the cover layer of the second stack are laminated to be on opposite sides of each other, Wherein the first stack further comprises a package and a touch panel, the package is disposed on the organic electroluminescent layer, and the touch panel is directly disposed on the package, Wherein the backplane only includes TFT devices and lines, and Wherein the flexible OLED display module can have a radius of curvature less than 2 mm.

4. The flexible OLED display module according to claim 3, wherein the flexible OLED display module can have a radius of curvature less than 1 mm.

5. A flexible OLED display module, comprising: A first stack, comprising: A substrate, A backplane disposed on the substrate, and An organic electroluminescent layer formed on the backplane; and A second stack laminated with the first stack, comprising: A cover layer, and A deposited polarizer formed on the cover layer, Wherein the substrate of the first stack and the cover layer of the second stack are laminated to be on opposite sides of each other, Wherein the first stack further comprises a package and a touch panel, the package is disposed on the organic electroluminescent layer, and the touch panel is directly disposed on the package, wherein the backplane only includes TFT devices and lines, and wherein the flexible OLED display module operates at a brightness value of at least 700 cd / m 2 and the increase in the operating temperature does not exceed 26 °C.

6. The flexible OLED display module according to any one of claims 1-5, wherein the touch panel is disposed within 10 μm of the neutral plane of the flexible OLED display module.

7. The flexible OLED display module according to any one of claims 1-5, wherein the laminate between the first stack and the second stack is selected from one of the following: a pressure-sensitive adhesive, an epoxy resin, and an optically clear adhesive.

8. The flexible OLED display module according to any one of claims 1-5, wherein one or more of the following are true: i) The deposited polarizer is a deposited circular polarizer, which includes a deposited linear polarizer and a deposited quarter-wave retarder; ii) Further includes a color filter disposed in at least one of the first stack and the second stack; and iii) wherein the substrate is a plastic with a glass transition temperature below 200 °C.

9. The flexible OLED display module according to any one of claims 1-8, wherein the flexible OLED display module is integrated into one of the following: a flat panel display, a computer monitor, a medical monitor, a television, a billboard, a lamp for internal or external lighting and signaling, a head-up display, a laser printer, a telephone, a mobile phone, a tablet computer, a phablet, a personal digital assistant PDA, a wearable device, a laptop computer, a digital camera, a video camera, a viewfinder, a microdisplay, a 3-D display, a vehicle, a large area wall, a theater or stadium screen, and a sign.

10. A method of manufacturing a flexible OLED display module, the method comprising: providing a substrate; forming a backplane on the substrate, wherein the backplane only includes TFT devices and lines; providing an organic electroluminescent layer on the backplane; providing a package and a touch panel, wherein the package is disposed on the organic electroluminescent layer, and the touch panel is directly disposed on the package, wherein the substrate, the backplane, the organic electroluminescent layer, the package, and the touch panel form a first stack; providing a cover; depositing a polarizer on the cover to form a second stack; drying the second stack; and laminating the second stack with the first stack, wherein the substrate of the first stack and the cover of the second stack are laminated to be on opposite sides of each other, and wherein at least one of the following is true: i) wherein the thickness of the first stack is less than 60 μm, and the thickness of the second stack is less than 60 μm; and ii) the thickness of the flexible OLED display module is formed to be less than 150 μm.

11. A method of manufacturing a flexible OLED display module, the method comprising: providing a substrate; forming a backplane on the substrate, wherein the backplane only includes TFT devices and lines; providing an organic electroluminescent layer on the backplane; Provide a package and a touch panel, wherein the package is disposed on the organic electroluminescent layer, and the touch panel is directly disposed on the package, wherein the substrate, the backplane, the organic electroluminescent layer, the package and the touch panel form a first stack; Provide a cover; Deposit a polarizer on the cover to form a second stack; Dry the second stack; And Laminate the second stack with the first stack, wherein the substrate of the first stack and the cover of the second stack are laminated to be on opposite sides of each other, and wherein the flexible OLED display module can have a radius of curvature of less than 2 mm.

12. A method of manufacturing a flexible OLED display module, the method comprising: Provide a substrate; Form a backplane on the substrate, wherein the backplane includes only TFT devices and lines; Provide an organic electroluminescent layer on the backplane; Provide a package and a touch panel, wherein the package is disposed on the organic electroluminescent layer, and the touch panel is directly disposed on the package, wherein the substrate, the backplane, the organic electroluminescent layer, the package and the touch panel form a first stack; Provide a cover; Deposit a polarizer on the cover to form a second stack; Dry the second stack; And Laminate the second stack with the first stack, wherein the substrate of the first stack and the cover of the second stack are laminated to be on opposite sides of each other, and wherein the flexible OLED display module operates at a brightness value of at least 700 cd / m 2 and the increase in the operating temperature does not exceed 26 °C.

13. The method of manufacturing a flexible OLED display module according to any one of claims 10-12, wherein the laminating step laminates the first stack and the second stack with a laminate selected from a pressure-sensitive adhesive, an epoxy resin, and an optically clear adhesive.

14. The method of manufacturing a flexible OLED display module according to any one of claims 10-12, wherein the deposited polarizer film is a deposited circular polarizer, which comprises a deposited linear polarizer and a deposited quarter-wave retarder.

15. The method of manufacturing a flexible OLED display module according to any one of claims 10-12, further comprising providing a color filter in at least one of the first stack and the second stack.

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