eMagin (United States)

Organic Light Emitting Diode (OLED) based displays are beginning to enter the main stream display and television market. OLED based Head mounted displays (HMD) are a major part of wearables, particularly near-to-the-eye displays. The brightness of the displays is critical for many applications including Augmented and Virtual Reality. eMagin’s recent efforts to develop high brightness OLED microdisplays will be presented.

As part of its continuing effort to improve both the resolution and optical performance of AMOLED microdisplays, eMagin has recently developed an SXGA (1280×3×1024) microdisplay under a US Army RDECOM CERDEC NVESD contract that combines the world's smallest OLED pixel pitch with an ultra-high brightness green OLED emitter. This development is aimed at next-generation HMD systems with "see-through" and daylight imaging requirements. The OLED pixel array is built on a 0.18-micron CMOS backplane and contains over 4 million individually addressable pixels with a pixel pitch of 2.7 × 8.1 microns, resulting in an active area of 0.52 inches diagonal. Using both spatial and temporal enhancement, the display can provide over 10-bits of gray-level control for high dynamic range applications. The new pixel design also enables the future implementation of a full-color QSXGA (2560 × RGB × 2048) microdisplay in an active area of only 1.05 inch diagonal. A low-power serialized low-voltage-differential-signaling (LVDS) interface is integrated into the display for use as a remote video link for tethered systems. The new SXGA backplane has been combined with the high-brightness green OLED device developed by eMagin under an NVESD contract. This OLED device has produced an output brightness of more than 8000fL with all pixels on; lifetime measurements are currently underway and will presented at the meeting. This paper will describe the operational features and first optical and electrical test results of the new SXGA demonstrator microdisplay.

eMagin Corporation has recently developed long-life OLED-XL devices for use in their AMOLED microdisplays for head-worn applications. AMOLED displays have been known to exhibit high levels of performance with regards to contrast, response time, uniformity, and viewing angle, but a lifetime improvement has been perceived to be essential for broadening the applications of OLED's in the military and in the commercial market. The new OLED-XL devices gave the promise of improvements in usable lifetime over 6X what the standard full color, white, and green devices could provide. The US Army's RDECOM CERDEC NVESD performed life tests on several standard and OLED-XL panels from eMagin under a Cooperative Research and Development Agreement (CRADA). Displays were tested at room temperature, utilizing eMagin's Design Reference Kit driver, allowing computer controlled optimization, brightness adjustment, and manual temperature compensation. The OLED Usable Lifetime Model, developed under a previous NVESD/eMagin SPIE paper presented at DSS 2005, has been adjusted based on the findings of these tests. The result is a better understanding of the applicability of AMOLEDs in military and commercial head mounted systems: where good fits are made, and where further development might be needed.

We report preparation and characterization of novel bicomponent metal-based photonic crystals having submicron three-dimensional (3D) periodicity. Fabricated photonic crystals include SiO2 sphere lattices infiltrated interstitially with metals, carbon inverse lattices filled with metal or metal alloy spheres, Sb inverse lattices, and Sb inverse lattices filled with Bi spheres. Starting from a face centered SiO2 lattice template, these materials were obtained by sequences of either templating and template extraction or templating, template extraction, and retemplating. Surprising high fidelity was obtained for all templating and template extraction steps. Scanning electron microscopy (SEM), small angle X-ray scattering (SAXS) and differential scanning calorimetry (DSC) were used to characterize the structure and the effects of the structure on calorimetric properties. To the best of our knowledge, SAXS data on metallic photonic crystals were collected for first time.

We present the design and early evaluation results of the world's highest pixel pitch full-color 800x3x600- pixel, active matrix organic light emitting diode (AMOLED) color microdisplay for consumer and environmentally demanding applications. The design premises were aimed at improving small area uniformity as well as reducing the pixel size while expanding the functionality found in existing eMagin Corporations' microdisplay products without incurring any power consumption degradation when compared to existing OLED microdisplays produced by eMagin. The initial results of the first silicon prototype presented here demonstrate compliance with all major objectives as well as the validation of a new adaptive gamma correction technique that can operate automatically over temperature.

Abstract We report the fabrication of efficient surface‐emitting white organic light emitting diodes (OLEDs) on single crystal silicon substrates using a high Tg blue host layer with co‐deposited blue‐green and red‐orange emitter dopant molecules. The emission layer is sandwiched between a Spiro‐TAD hole transport layer and an Alq3electron transport layer. The devices operate near the 1931 CIE white balance point with luminous efficiencies of 2.75 lum/W and current efficiencies of 8 cd/A, representing luminance of ∼1600 cd/m2at a current density of 20 mA/cm2. When tested under accelerated and uninterrupted 90% pulsed 20 mA/cm2drive, our OLEDs yield luminance half‐lives of over 5000 hours, which represent normalized half life at 100 cd/m2for color microdisplays of greater than 20,000 hours assuming a 25% duty cycle similar to that created by full motion video. These results enable us to meet commercial and military requirements for OLED color microdisplays employing passband filters for red, green and blue subpixel elements.

eMagin has developed numerous enhancements to organic light emitting diode (OLED) technology, including a unique, up- emitting structure for OLED-on-silicon microdisplay devices. Recently, eMagin has fabricated full color SVGA+ resolution OLED microdisplays on silicon, with over 1.5 million color elements. The display is based on white light emission from OLED followed by LCD-type red, green and blue color filters. The color filters are patterned directly on OLED devices following suitable thin film encapsulation and the drive circuits are built directly on single crystal silicon. The resultant color OLED technology, with hits high efficiency, high brightness, and low power consumption, is ideally suited for near to the eye applications such as wearable PCS, wireless Internet applications and mobile phone, portable DVD viewers, digital cameras and other emerging applications.

Abstract Vacuum‐deposited and spin‐coated color changing media (CCM) films for use in color microdisplays with blue OLED emitters have been demonstrated with optical density 5.0 and 2.8 per micron at the maximum of absorption, respectively. CCM efficiency has been studied as a function of film thickness, dopant concentration and excitation wavelength.

The steady state photoinduced absorption (PA), photoluminescence (PL), PL detected magnetic resonance (PLDMR), and PA-detected magnetic resonance (PADMR) of poly- and oligo-(para-phenylenes) films is described. In particular, the excitation density (laser power) N<SUB>O</SUB> dependence of the PA, PL, and PLDMR signals are analyzed by means of a new rate equation model. It describes the dynamics of singlet excitons (SE's) and polarons in all three experiments with the same set of parameters. This yields the first quantitative analysis of the interaction of SE's and polarons in conjugated polymers. The model is based on the observations that mobile SE's are quenched by trapped and free polarons and that the spin 1/2 magnetic resonance conditions reduce the total polaron and triplet exciton (TE) populations. Since the sublinear N<SUB>O</SUB> dependence of the positive (PL-enhancing) spin 1/2 PLDMR and the polaron PA band are essentially the same, we conclude that that PLDMR is due to reduced quenching of SE's by polarons. The agreement between the model, the current results, and results from other spectroscopic techniques provides strong evidence for this quenching mechanism. It also suggests that it is a very significant process in luminescent (pi) - conjugated materials and organic light-emitting devices, which needs to be taken into account especially at high excitation densities such as in lasing action.

We report experimental results on the evaluation of a sealing technique for organic light emitting diodes (OLEDs) used for high-resolution color microdisplay applications. Based on production and processing requirements for active matrix OLEDs (AMOLEDs) on silicon, the sealing process must protect the device against moisture and oxygen, not only during operation and storage but also during production. A conformal polymer/metal(oxide)/polymer multi-layer technology was selected for this purpose. AMOLED test structures were produced and tested with and without sealing under ambient conditions as well as in water. The applied sealing process was shown to be compatible with all steps of the OLED-based microdisplay production of eMagin Corporation. Our results confirm that encapsulating AMOLEDs with the described process leads to increased stability, both under operation as well as for storage purposes.