Ultra Thin Face-Coupled Scalable LED Backlight Technology For Large Format LCD TV. TilEx™ Thin Collimating Modular LGP with Face-Coupled Immersed LED

Large backlights can be constructed from a number of standard modules. Individual modules are designed to “leak” light to their neighbors. In this way LED rank & binning and aging effects on local nonuniformity are reduced.

Foconic couplers can also be integrally formed in a modular or large size light extracting LGP. SMD LEDs are mounted or preferably bonded to a back face of an LGP

Brighter Future With Ultimate Dream Backlight: Converting Top Window Low Rank SMD LED into A Large Area High Bright  Directional Uniform Emitter.

Ultra-thin Patented CRATER™ side emitting  foconic encapsulator integrally coupled to a  planar flux  extracting & collimating ExFRACTOR™ light guide enables to construct low-profile modular backlights.

• TilEx© represents a disruptive technology of the future in view of the following quantum leap benefits for LCD of any size:
  Factor 2-20 Higher power efficiency due to an improved EQE (extraction quantum efficiency) of LED and more efficient and directional light extraction by a secondary LED optics:
  •  LED output can be improved by 25% – 200% depending on LED chip type and lamp packaging. Foconic TIR CRATER™  coupler collects all the light emitted by a top window chip and collimates  it to propagate along a planar LGP solely by TIR without any uncontrollable leakage.
  • Flexible Luminance distribution unattainable with conventional edge-coupled design : from a highly collimated one with an on-axis gain of 20  for small displays to an isotropic Lambertian for large wide - angle LCD TV.
• Low profile: LGP thickness is determined by a height of a CRATER™ coupler operating to intercept and inject LED’s flux into main LGP. Its height and maximal radius are similar to  LED’s chip size and are reduced to just 0.25 mm for small power package to 3mm  for more powerful 1W  LED.
• Modular BLU design scalable to any size. A  large area BLU is constructed as a 2D array of smaller standard modules.  Drastically reduced NRE, as same modules can be used for different BLU size.
• Improved Image Quality & Power Efficiency.  Modular design also allows dynamic dimming of individual units to conform to an image content. Dynamic dimming is known to save up to 50% of power compared to conventional BLU continuously operating at maximal luminance. It also greatly improves an image quality by reducing a luminance of a black reference resulting in a larger contrast ratio and reproducible shades of gray.
• Ease of mounting: TilEx™modular backlights are ideally suited for insert molding providing a complete backlight module solution.

Uniform flux extraction is a core problem of all edge-coupled backlight systems. In order to produce a uniform luminance Extractor density and/or shape should generally have a complex 2-D Distributions. Less known is a fact that there is a infinite number of solutions for any particular system. Indeed with a very low extractor density one can produce an even luminance already with a uniform density. However a resulting luminance would be low, as there are elevated flux losses caused by longer travel passes of photons inside a lightguide and reflection on side reflectors.
 
Our patented have a unique energy conservation property: light is extracted at a shortest possible distance from light sources. In this way a maximal luminance is ensured.
Our unique KEREN ™ CAD/CAM Software Package for non-imaging optics enables a fully automatical design of optimal ExFRACTOR™ features in a series of gracefully converging iterations for any extractor shape: dot, spherical & CPC lenses, prismatic & cylindrical grooves etc. The resulting pattern is then antialiased (randomized) and postprocessed for immediate production of stamper for mold cavities, chemical & laser etching, EB lithography etc.

LUMINANCE DISSTRIBUTION AT INITIAL AND FINAL ITERATIONS
NONUNIFORMITY IS IMPROVED FROM 5:1 TO BETTER THAN 1.1:1

Fully Assembled 2.2” BLU with discontinuous V-Groove  extractors

LGP with non-uniformly distributed simple spherical extractors. Actual extractor size: 20-50 um 

Example of Extractor distribution for ultra-thin microdisplay backlight. 
Notice a unique irregular pattern, which is very different from usual
monotonically changing distributions.

Face-coupled Backlight. Complex 2-D flux Extractor Distributions (right)
Producing Uniform Luminance (left)

 Stamper with complex 50um spherical and V-Groove lenses

Magnified fragment of 50um V-Groove pattern

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Unlike most of other companies Visus is not a “one – product” company and offers a complete range of technologies for virtually all LED markets including LED chip and lamp design. A control of a complete “photon supply chain” starting from an optimized photon generation and extraction at LED level and down to secondary light management optics enables to attain maximal performance not possible when considering only one system component, e.g. LED, lightguide panel or BEF.
 
All our products employ ground-breaking patented optical architecture belonging to FID (Flat Illumination Device) class of optical systems. In contrast to existing ubiquitous illumination devices FIDs operate with a sharply reduced number of powerful compact light sources and redistribute their flux with a surgical precision using hybrid multilayer waveguides and photonic couplers. A combination of optical technology along with novel waveguide materials and LED packaging and encapsulation culminated in a large family of ultra-slim and power efficient FIDs for virtually all of diversified multibillion markets for general and special illumination devices.

Key technologies include:

1. ExFRACTOR™ waveguides with optimized flux extraction patterns.
2. Optimized NLW (Non-Linear Wedge) Extratorless waveguides with reduced profile & weight & cost and no need for extraction pattern,
3. HOW™ Hybrid Optical Wave guides for LCD backlights, including large LCD TVs, general & automotive illumination and signage.
4. TilEx™modular backlights for large LCD TV.
5. Ultra-thin “Functional Flat Fiber” waveguides for LCD BLUs.
6. Ultra-thin “Flat Fiber” waveguides for keypad & keyboard backlighting
7. FoCOUPLER™ energy conserving ultra - compact foconic flux couplers for LED primary & secondary optics.
8. Brightness Enhancing & Diffusing Film components (BEFs etc):
   8.1.   SADO ™ Stacked Amplifying Directional Optical Transflector Film.
   8.2.   SHUTLE ™ Shaped Hollow Ultra-Thin Luminance Enhancement Film
9. Advanced Microreplication Technology for microprismatic extractors
10. KEREN ™ CAD/CAM Software Package is a most advanced pioneering  proprietary software package enabling a fully automatic synthesis of various non imaging optical systems

Proven track record. Visus has been at a cradle of inventing a number of key optical systems and components which have turned into core technologies in LCD and lighting industries. In mid 80’s it pioneered a development of light guides with distributed light extractors turned later into an indispensable core component of all LCD backlights. It also used for the first time 3M’s SOLF (developed for a totally different application, namely hollow tubular light guides) for LCD backlights. Later it became known as BEF, another core component used in every LCD. In a general lighting first computer generated asymmetrical reflectors (car headlights, road & projection lighting) have been licensed by Visus. Today many of European cities and highways are lighted by these uniquely optimized reflectors. In Visual Ergonomics our methods based on Visual Field Visibility analysis have become a standard approach for Visual Performance evaluation recommended by CIE, IPS and other international standard organizations.

VISUS concentrates on finding immediate novel technological solutions to rapidly changing market demands and establishing a toll position by continuing patenting its intellectual property and building a significant IP portfolio. In this regard, VISUS has a constantly growing number of omnibuses and CIP patents covering extensive technologies for compact illumination devices for virtually all of diversified multi billion markets for general and special illumination devices with a special emphasis of LED powered devices.

Visus continues to file under the CIP  vehicle a number of follow-up patents relating to several classes of new illuminating systems, in particular to plastic light enhancing components (BEFs etc.), ultra bright LEDs (primary @ secondary optics) and LED powered lighting systems with energy conserving ultra compact optical couplers.

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