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Online paper strength testing methods are currently unavailable, and papermakers have to wait for manufacture of a complete reel to assess quality. The current methodology is to test a very small sample of data (less than 0.005%) of the reel to confirm that the paper meets the specifications. This paper attempts to predict paper properties on a running paper machine so that papermakers can see the test values predicted in real time while changing various process parameters. This study was conducted at a recycled containerboard mill in Chicago using the multivariate analysis method. The program provided by Braincube was used to identify all parameters that affect strength characteristics. Nearly 1600 parameters were analyzed using a regression model to identify the major parameters that can help to predict sheet strength characteristics. The coefficients from the regression model were used with real-time data to predict sheet strength characteristics. Comparing the prediction with test results showed good correlation (95% in some cases). The process parameters identified related well to the papermaking process, thereby validating the model. If this method is used, it may be possible to predict various elastic moduli (E11, E12, E22, etc.) in the future as the next step, rather than the traditional single number “strength” tests used in the containerboard industry, such as ring crush test (RCT), corrugating medium test (CMT), and short-span compression strength test.

In this paper we will discuss the key technologies needed for fabricating flexible OLED lighting panels with specific focuses on flexible substrates, high efficacy phosphorescent materials and thin film encapsulation technologies. We will report results of 15 cm × 15 cm phosphorescent OLED (PHOLED™) flexible lighting panels using flexible substrates.

In this paper we discuss the challenges involved in scaling from small size pixels to large area OLED lighting panels, with specific focus on panel luminance uniformity, resistive loss and lifetime. We also discuss panel design and report results for a 15 cm × 15 cm phosphorescent OLED (PHOLED) lighting panel.

We describe encapsulated passive matrix, video rate organic light-emitting diode (OLED) displays on flexible plastic substrates using a multilayer barrier encapsulation technology. The flexible OLED (FOLED™) displays are based on highly efficient electrophosphorescent OLED (PHOLED™) technology deposited on barrier coated plastic (Flexible Glass™ substrate) and are hermetically sealed with an optically transmissive multilayer barrier coating (Barix™ encapsulation). Preliminary lifetime to half initial luminance (L0∼100 cd/m2) of order 200 h is achieved on the passive matrix driven encapsulated 80 dpi displays; 2500 h lifetime is achieved on a dc tested encapsulated 5 mm2 FOLED test pixel. The encapsulated displays are flexed 1000 times around a 1 in. diameter cylinder and show minimal damage.

We fabricate long-lived organic light-emitting devices using a 175 μm thick polyethylene terephthalate substrate coated with an organic–inorganic multilayered barrier film and compare the rate of degradation to glass-based devices. The observed permeation rate of water vapor through the plastic substrate was estimated to be 2×10−6 g/m2/day. Driven at 2.5 mA/cm2, we measure a device lifetime of 3800 h from an initial luminance of 425 cd/m2.

Electrophosphorescent devices with fac-tris(2-phenylpyridine)iridium as the green emitting dopant have been fabricated with a variety of hole and exciton blocking materials. A device with aluminum(III)bis(2-methyl-8-quinolinato)4-phenylphenolate (BAlq) demonstrates an efficiency of 19 cd/A with a projected operational lifetime of 10 000 h, operated at an initial brightness of 500 cd/m2; or 50 000 h normalized to 100 cd/m2. An orange-red electrophosphorescent device with iridium(III) bis(2-phenylquinolyl-N,C2′)acetylacetonate as the dopant emitter and BAlq as the hole blocker demonstrates a maximum efficiency of 17.6 cd/A with a projected operational lifetime of 5000 h at an initial brightness of 300 cd/m2; or 15 000 h normalized to 100 cd/m2. The average voltage increase for both devices is

Significant progress has been made in recent years in flexible AMOLED displays and numerous prototypes have been demonstrated. Replacing rigid glass with flexible substrates and thin-film encapsulation makes displays thinner, lighter, and non-breakable - all attractive features for portable applications. Flexible AMOLEDs equipped with phosphorescent OLEDs are considered one of the best candidates for low-power, rugged, full-color video applications. Recently, we have demonstrated a portable communication display device, built upon a full-color 4.3-inch HVGA foil display with a resolution of 134 dpi using an all-phosphorescent OLED frontplane. The prototype is shaped into a thin and rugged housing that will fit over a user's wrist, providing situational awareness and enabling the wearer to see real-time video and graphics information.

We present a 7.5 cm x 7.5 cm white PHOLED TM lighting panel that delivers 1,000 cd/m 2 with 68 lm/W efficacy, CRI > 80 and lifetime to LT70 ≈ 15,000 hrs. A simple all-phosphorescent device architecture, including a highly stable light blue phosphorescent emitter-host system, is used to reduce panel power consumption, extend operational lifetime and demonstrate exceptional emission color stability with aging.

Today organic light emitting diodes (OLEDs) are entering the market lace as a competitive flat panel display technology. Rapidly OLED displays are moving from small passive matrices to full color active matrices built on conventional indium tin oxide coated glass. The work in this paper is focused on developing high resolution full color displays on flexible substrates. Presented here will be new developments in high efficiency OLED displays with the application of this technology to flexible substrates thus allowing a whole new generation of display concepts to be realized.

We have fabricated saturated red, orange, yellow and green OLEDs, utilizing phosphorescent dopants. Using phosphorescence based emitters we have eliminated the inherent 25% upper limit on emission observed for traditional fluorescence based systems. The quantum efficiencies of these devices are quite good, with measured external efficiencies > 15% and > 40 lum/W (green) in the best devices. The phosphorescent dopants in these devices are heavy metal containing molecules (i.e. Pt, and Ir), prepared as both metalloporphyrins and organometallic complexes. The high level of spin orbit coupling in these metal complexes gives efficient emission from triplet states. In addition to emission from the heavy metal dopant, it is possible to transfer the exciton energy to a fluorescent dye, by Forster energy transfer. The heavy metal dopant in this case acts as a sensitizer, utilizing both singlet and triplet excitons to efficiently pump a fluorescent dye. We discuss the important parameters in designing electrophosphorescent OLEDs as well as their strengths and limitations. Accelerated aging studies, on packaged devices, have shown that phosphorescence based OLEDs can have very long device lifetimes.

— In this paper, the design criteria for scaling up from small-area organic light-emitting-diode (OLED) pixels to large-area OLED light panels is described. Particular focus is placed on using phosphorescent OLEDs (PHOLEDs) to maximize panel efficacy and uniformity and minimize operating temperature. Data for a pair of all-phosphorescent 15 × 15 cm OLED light panels are also presented: Panel 1 has 62-lm/W efficacy, CRI = 81, CCT = 3180K, and lifetime to LT70 = 18,000 hours at 1000 cd/m2 and Panel 2 has 58-lm/W efficacy, CRI = 82, CCT = 2640K, and lifetime to LT70 = 30,000 hours at 1000 cd/m2. Operating at a 3000 cd/m2 (7740 lm/m2), Panel 2 has 49-lm/W efficacy with lifetime to LT70 = 4000 hours. Excellent panel lifetime is enabled by a stable light-blue phosphorescent materials system and by the use of efficient phosphorescent emitters that ensure very low panel temperature without any additional thermal management.

— Work on the world's first wrist-worn communications device built on a flexible, low-power-consumption full-color AMOLED using phosphorescent OLEDs is presented. The device offers the wearer the ability to see high-information-content video-rate information in a thin-and-rugged-form-factor 4-in. QVGA display, conformed around a human wrist.

We present a novel all-phosphorescent AMOLED pixel architecture with a red, green, light blue and deep blue sub-pixel design. The highly efficient light blue reduces power consumption by 33% compared to an equivalent conventional RGB display using a fluorescent blue sub-pixel. Furthermore, by using a light and deep blue sub-pixel layout, the lifetime of the display will be significantly increased due to the reduced on-time required for the deep blue sub-pixel. Here we demonstrate this new design in a 2.5-inch AMOLED panel.

We present a 15 cm × 15 cm PHOLEDTM lighting panel that operates with 50 lm/W efficacy, CRI = 87, CCT = 3055 K and lifetime to LT70 ≅ 10,000 hrs at 1,000 cd/m2. We also present a panel with 58 lm/W efficacy, CRI = 86 and CCT = 2790 K at 1,000 cd/m2, and a small-area lighting pixel with 109 lm/W efficacy, CRI = 80, CCT = 3295 K and lifetime to LT70 ≅ 15,000 hrs at 1,000 cd/m2. A highly stable light blue phosphorescent host-emitter system is used to reduce power consumption, extend operational lifetime and demonstrate exceptional emission color stability with aging.

We present our work on the world's first wrist worn communication device built upon a flexible low power consumption full color AMOLED using phosphorescent materials. The device offers the wearer the ability to see high information content video rate information in a thin and rugged form factor 4-inch QVGA display, conformed around a human wrist.

A low temperature, 180 °C, amorphous Si (a-Si:H) process on bonded polyethylene naphthalate substrates is discussed and a 4.1-inch QVGA active matrix (AM) phosphorescent OLED display is demonstrated. The n-channel thin-film transistors (TFTs) exhibited saturation mobilities of 0.773 cm2/V-sec, layer to layer registration distortion less than 10ppm and low defectivity. The efficiency of the OLED display is 39 cd/A at 500 nits.

We present results demonstrating that low power consumption phosphorescent AMOLED displays can be fabricated on ultra-thin (25 μm) stainless steel substrates, combining an amorphous silicon backplane with a top emission phosphorescent OLED frontplane. Preliminary results show the performance of amorphous silicon backplanes adequate to drive AMOLED displays, and flexibility results on these backplanes show that they operate when conformed to a tight diameter of only 5 mm.

— Organic light-emitting-device (OLED) devices are very promising candidates for flexible-display applications because of their organic thin-film configuration and excellent optical and video performance. Recent progress of flexible-OLED technologies for high-performance full-color active-matrix OLED (AMOLED) displays will be presented and future challenges will be discussed. Specific focus is placed on technology components, including high-efficiency phosphorescent OLED technology, substrates and backplanes for flexible displays, transparent compound cathode technology, conformal packaging, and the flexibility testing of these devices. Finally, the latest prototype in collaboration with LG. Phillips LCD, a flexible 4-in. QVGA full-color AMOLED built on amorphous-silicon backplane, will be described.

We demonstrate full color, top emission, active matrix OLED displays on flexible stainless steel substrates. The 100 dpi QVGA displays are driven by LTPS TFT backplane with excimer laser annealed poly-Si. To our knowledge this is the world's highest resolution full color flexible AMOLED display on steel foil demonstrated to date. Encapsulation is by a multilayer thin film.

Fully encapsulated passive matrix, video rate, phosphorescent OLED displays on flexible plastic substrates using a multilayer barrier encapsulation technology are described. The flexible OLED (FOLED™) displays are based on highly efficient electrophosphorescent OLED (PHOLED™) technology deposited on barrier coated plastic film (Flexible Glass™ substrate) and are hermetically sealed with an optically transmissive multilayer barrier coating (Barix™ Encapsulation). Preliminary lifetime to half initial luminance (Lo∼100 cd/m2) of order 200 h is achieved on the encapsulated 80 dpi displays using a passive matrix drive at room temperature; 2500 h lifetime is achieved on a dc tested encapsulated 5 mm2 FOLED test pixel. The encapsulated displays are flexed 1000 times around a 1″ diameter cylinder and show minimal damage.

The efficiency-vs-current characteristics of phosphorescent organic light emitting diodes (PHOLEDs™) have been studied and compared to fluorescent small molecule organic light emitting diodes (SMOLED) and fluorescent polymer light emitting diodes (PLED). Results show that high efficiency PHOLEDs have significantly higher luminous efficiency than SMOLEDs and PLEDs at both the low and high drive current regimes required for active and passive matrix display applications. The efficiency roll-off of both phosphorescent and fluorescent devices is comparable. Long triplet exciton lifetime and the possible triplet-triplet annihilation do not explain this similarity. Other causes such as polaron-exciton annihilation and electric field induced photoluminescence quenching are provided.