ID C21C: Flat Panel Displays How to Overcome High-Ambient Light Conditions
Renesas Electronics America Inc. Yasuhiro Okada, Display BU Engineering Ma...
Yasuhiro Okada Assistant Manager NEC LCD Technologies (NLT), Japan Assistant Manager within the Sales Promotion Department of NEC LCD Technologies – Product planning - LED backlight LCD products and new concept products; customer support for US and western Japan; development of marketing collateral materials; tradeshow management and support
Additional Work Experience Engineering manager NECELAM (10/06 to 8/09) providing technical support; failure analysis of RMA’d product; supported customers and field sales for design-ins and post sales support Cell process engineering; analysis production line productivity; product engineering at NEC LCD factory in Akita, Japan Product development activities including documentation for new products and sales collateral materials
Low power consumption Long life LEDs Thin profile and light weight design Replaceable LED light source unit
Suited for a variety of ambient-light environments Proprietary transflective LCD technologies Super Reflective NLT (SR-NLT) Super Transmissive NLT (ST-NLT)
2D/3D displays Color enhancement E-paper On-cell touch
Super-Fine TFT (SFT)
High luminance and wide color gamut Superior image quality Ultra-wide viewing angles
Emerging Technologies Long-term product support Amorphous silicon (A-Si) displays
• New 2/3 dimensional displays Low-temperature polysilicon (LTPS) displays • Color enhancement Low power consumption Long life LEDs e-Paper LED Backlight •LCDs Thin profile and light weight design Replaceable LED light source unit • On-cell Touch • Long Term Support/Production Suited for a variety of ambient-light Natural Light TFT (NLT)
Emerging Technologies
environments Proprietary transflective LCD technologies Super Reflective NLT (SR-NLT) Super Transmissive NLT (ST-NLT)
2D/3D displays Color enhancement E-paper On-cell touch
Super-Fine TFT (SFT)
High luminance and wide color gamut Superior image quality Ultra-wide viewing angles
CCFL Backlight Systems High bright CCFL Touch panels will reduce a display’s luminance and increase surface reflections making it harder to see. Extreme brightness of 1100 nits offsets the reduction of luminance and reflection.
High bright CCFL backlight system NL8060BC31-36 1100 nits
LED Backlight Systems High bright LED To improve backlight life, NEC LCD Technologies optimized the LED alignment and heat dissipation design achieving a high bright LED backlight system comparable to high bright CCFL backlights.
High bright LED backlight system NL6448BC33-70F 800 nits
AR Film Details Front Low index layer (Sio2 and etc.) High index layer (TiO2, ITO, Nb2O5 and etc.) SiO2 High index layer (TiO2) SiO2 Hard coat or Anti-glare layer Base film (TAC, PET and etc.) Adhesive material Back 23
AG Film Details Front Plastic layer including silica or plastic beads TAC (Triacetylcellulose ) PVA (Polyvinyl alcohol ) TAC (Triacetylcellulose ) Adhesive material Back
SR-NLT – Super Reflective NLT Backlight ON or OFF – Highly reflective surface, great for direct sunlight applications where backlight is normally off for maximum power savings
3:1 is minimum contrast ratio to see image in sunlight
Advantages of ST-NLT & SR-NLT ST-NLT & SR-NLT products carry full manufacturer’s warranty. NEC uses “passive” enhancements and avoids the reliability pitfalls of high brighting or overdriving lighting components by “brute force”. While most customers shop “peak luminance” figures what they buy is “contrast”. An NEC ST-NLT panel @ 375 nits equals a standard panel @ 810 nits. Overdriving backlights is not needed. By increasing the peak (white) luminance, black level also rises making the panel no better in contrast. It may actually cause “wash out”. 35
Additional Comments Power is not free Higher power designs are typically more complex, larger & expensive. Higher power in the form of heat. Higher operating temperatures create opportunities for failure. Larger mechanical “footprint” dictates larger product designs.
