High Bright Display Technologies & The Advantages of VBOND

1. High Bright Display Technologies & The Advantages of VBOND

2. Large LCD displays for Dynamic Signage • Retail digital signage is a great market. • And now you want to take large LCDs outside. • It should be easy, right?

3. Large LCD displays for Dynamic Signage • New displays are 500 nits + • New displays are 2000+ : 1 contrast • They should be perfect, right?

4. 1 meter 1 meter 1 meter What is a nit? A nit is a unit of projected light energy from one candle, measured from its source,measured one meter away, measured over a one meter square area. A footlambert is the same light measured one foot away, over a one foot square area. 1 ft lambert is the same as 3.426 nits

5. 350nits Contrast ratios: two methods, two results Extrinsic Contrast Ratio A reading from a distance, taking into account ambient light and reflections. A good extrinsic contrast ratio is 10 :1. Intrinsic Contrast Ratio On the surface, the display, may read a 300:1 contrast ratio. This does not take into account ambient lighting. In addition, the light meter is measuring total flux regardless of angular distribution

6. How LCDs work • Liquid Crystal Display • Liquid = Fluid • Crystal = Organized Molecular Structure When placed onto an alignment layer, the molecules will track in the general direction of the grooves.

7. How LCDs work Rear Polarizer Cell Gap Alignment Layer Front Polarizer Transistors on rear glass Color filter on front glass Light from the backlight is polarized and then twists 90 degrees through the LC material allowing it to pass through the front polarizer.

8. How LCDs work The transistor applies an electrical field across the cell. The LCD molecules align to the direction of the flow. This prevents the LCD from twisting. No twist, no light transmission

9. 1000-1500 nits Luminance vs. Illuminance • 1500 nits is read only on “white” • Black level can go as high as 100-150 nits • This is only 10-15:1 contrast 1500 nits

10. Effects of illuminance 10,000 ft Candles Ambient light is “illuminance” 5% reflection 1500 nits 5% reflection adds to the “white” level but also to the “black” level, lowering the contrast ratio, washing out the display

11. Brightness versus Contrast • “Brightness” lightens or darkens the image. “Contrast” changes the distinction between the light and dark areas. • Humans can “perceive” roughly 100 levels of brightness. • Humans can “see” roughly 1 billions levels of contrast. • The human eye eventually becomes saturated with brightness and becomes more responsive to contrast. • Contrast ratio is much more significant than brightness in high ambient illumination environments. • The human visual system amplifies the difference in contrast: lateral inhibition

12. Contrast Example This is a test High contrast, easy to read This is a test Very low contrast but it is readable

13. Two types of display enhancements Display enhancement has two approaches: Brightness and Contrast. Outdoor LCD displays require both in order to make them readable in high ambient light. • Brightness: • Active- Adding more lights • Passive- Collects and focuses the available light • Contrast: • Direct Bonding AR glass • Air gap AR film and windows • For outdoor viewability, one must increase both!

14. Passive Brightness Enhancement Reflective Polarizer 50% of the light will transmit in either of these orientation No light will get through at this orientation 50% of the backlight light never gets out the front

15. Passive Brightness Enhancement Reflective Polarizer- Reflective Polarizer transmits all light in its orientation direction but will reflect back any light not in alignment. Additionally, the light is rotated slightly, to be reflected off the rear reflector.

16. Passive Brightness Enhancements BEF- Brightness Enhancement – Vertically aligned BEF- Collects light going left and right and directs it to the front Horizontally aligned BEF- Collects light going up or down and channels it forward

17. Passive Brightness Enhancements Transflective Film- Mirror film Light from the outside comes in, and is reflected off the rear wall

18. Passive Brightness Enhancement ELG- Enhanced Light Guide Light from the CCFLs is non-directed and bounces in all directions. Some light never makes out the front.

19. Passive Brightness Enhancement ELG- Enhanced Light Guide Light returning from reflective polarizer Light from CCFT Micro-prisms internal to light guide ELG with the Reflective Polarizer is very effective in converting non-collimated light to collimated light

20. Active Brightness Enhancement Dual tubes Multiple edge-lit tubes Multiple rear-lit tubes

21. Contrast Enhancement with Anti-reflecting technology Whether a film or glass bond, AR coatings eliminate reflective loss

22. Challenges of enhancing large LCDs • DBEF- Factories already use it • BEFs- Steals light from the sides, not good • ELGs- Works with edge lighting, not rear lighting. • Transflective film, hmmm maybe. • Backlighting- Displays already have high bright back lights • AR film- Not big enough and very expensive

23. More challenges with large LCDs • Large LCDs are designed for TV, with fast response and wide viewing angles. • Their structure lowers light transmission from backlights by 50% (more lights, heat and power with lower results). • Their fast responding LC material causes problems.

24. Challenges of enhancing large LCDs • Have we mentioned HEAT?!?!? 50% of the heat load is Infrared radiation Air gaps traps heat and allows it to go higher Lots of heat from the CCFLs

25. Heat is a big issue A display will go “isotropic” or “clear” at as low as 50o C Isotropic is the point where the LCD molecules go random (instead of organized, causing the display to go black

26. Luminance + Reflection Reflection Formulas Reflection = 5% x # of surfaces x ambient light = Contrast Ratio

27. Even with high bright backlights, contrast may be low Reflection = 10K ftC x 15% R= 1500 nits 5% 5% 1500 + 1500 = 1.85 :1 Contrast 5% 1500

28. VBOND eliminates reflective loss and increases contrast Reflection = 10K ftC x 2% R= 50 nits 5% 5% 1500*0.85 + 50 = 26 :1 Contrast 5% 50 1500 nits VBOND eliminates the two internal points of reflection. With AR coatings on the front, overall reflections drops to less than 2%

29. VBOND Benefits • Low reflective loss means higher contrast in high bright environments • Display are daylight readable at 500 nits, sunlight readable at 800 nits • Backlight power can be lowered to reduce overall power draw and less heat production • No air gap eliminates “greenhouse” effect heat rise. • Solid bond will conduct heat out of the display • Cooler displays will not “clear”or go isotropic as quickly. • No air gap prevents moisture from forming under the window.

30. Benefits of VBOND for Outdoor Signage • VBOND is not size dependent. Large size LCDs are no problem. • Glass thicknesses and other features such as chemical strengthening or tempering is offered. • Glass can be developed to reflect infrared radiation, lowering the heat load.

31. VBOND Benefits • Reworkable through production process • Reworkable in post-production • Low toxicity, environmentally friendly materials. • Excellent UV resistance • Excellent optical properties • Excellent mechanical properties • Low glass transition temperature