ID C 21 C Flat Panel Displays How

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ID C 21 C: Flat Panel Displays How to Overcome High-Ambient Light Conditions Renesas Electronics America Inc. Yasuhiro Okada, Display BU Engineering Manager 12 October 2010 © 2010 Renesas Electronics America Inc. All rights reserved. Version: 1. 1

Yasuhiro Okada n Assistant Manager NEC LCD Technologies (NLT), Japan l 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 n Additional Work Experience l 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 l Cell process engineering; analysis production line productivity; product engineering at NEC LCD factory in Akita, Japan l Product development activities including documentation for new products and sales collateral materials 2 © 2010 Renesas Electronics America Inc. All rights reserved.

Display Module Solutions Sophisticated solutions Sustainable support Industrial Mobile Displays 3 LED Backlight LCDs Natural Light TFT (NLT) Emerging Technologies § § Robust feature sets Long-term product support Amorphous silicon (A-Si) displays Low-temperature polysilicon (LTPS) displays § § 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) § § 2 D/3 D 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 Wide Format LCDs § More data on a single screen § 16: 9 aspect ratio © 2010 Renesas Electronics America Inc. All rights reserved.

Display Module Solutions § Robust feature sets Sophisticated solutions Sustainable support Industrial Mobile Displays 4 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 LED Backlight • e-Paper LCDs § Thin profile and light weight design § Replaceable LED light source unit • On-cell Touch • Long Term Support/Production for a variety of ambient-light § Suited Natural Light TFT (NLT) Emerging Technologies environments § Proprietary transflective LCD technologies § Super Reflective NLT (SR-NLT) § Super Transmissive NLT (ST-NLT) § § 2 D/3 D 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 Wide Format LCDs § More data on a single screen § 16: 9 aspect ratio © 2010 Renesas Electronics America Inc. All rights reserved.

Agenda n Properties of Light n Viewability in High Ambient Light Conditions n Solutions for High Ambient Light Conditions n Technology Overview 6 © 2010 Renesas Electronics America Inc. All rights reserved.

$Properties of Light n Refraction – the change in direction of light when passing$ Properties of Light n Refraction – the change in direction of light when passing through one transparent medium to another. AIR GLASS 9 © 2010 Renesas Electronics America Inc. All rights reserved.

Reflection & Glare in Strong Sunlight Standard AG surface Enhanced for sunlight readability High reflection Low contrast 14 Low reflection Improved contrast © 2010 Renesas Electronics America Inc. All rights reserved.

Attributes That Affect Viewability n Front of screen peak luminance n Contrast Standard Clear Surface Enhanced Panel Clearer but still whitish Higher Luminance 　and More Contrast 15 © 2010 Renesas Electronics America Inc. All rights reserved.

CCFL Backlight Systems n High bright CCFL l Touch panels will reduce a display’s luminance and increase surface reflections making it harder to see. l Extreme brightness of 1100 nits offsets the reduction of luminance and reflection. High bright CCFL backlight system NL 8060 BC 31 -36 1100 nits 17 © 2010 Renesas Electronics America Inc. All rights reserved.

LED Backlight Systems n High bright LED l 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 NL 6448 BC 33 -70 F 800 nits 18 © 2010 Renesas Electronics America Inc. All rights reserved.

CCFL vs. LED Backlight Systems CCFL Light source type Drive method Dimming range Thermal property Optical property deviation Power consumption Thermal performance Environmental 19 © 2010 Renesas Electronics America Inc. All rights reserved. LED Linear type Spot type AC High voltage INV creates harmonic noise DC 15 to 100% 0 to 100% Significant thermal independence Linear thermal independence Luminance: ± 10% Chromaticity: ± 0. 010 Luminance: over 10% Chromaticity: ～ 0. 025 High 40% lower than CCFL Low start-ability and shorter life at low temperatures Exothermic Small amount of Mercury free

AG & AR Passive Enhancement Films n Anti-Glare (AG) - diffuses reflection n Anti-Reflective (AR) - negates reflection Incident light Reflection Incident light AG 21 © 2010 Renesas Electronics America Inc. All rights reserved. AR

Anti-Reflection Film n The difference in reflection index and path creates a phase difference that negates the effect. Negates reflection Reflection 1 by Interference Incident light Reflection 2 Interface Incident light Reflection AR treatment Transmitted light 22 © 2010 Renesas Electronics America Inc. All rights reserved. LCD panel

AR Film Details Front Low index layer (Sio 2 and etc. ) High index layer (Ti. O 2, ITO, Nb 2 O 5 and etc. ) Si. O 2 High index layer (Ti. O 2) Si. O 2 Hard coat or Anti-glare layer Base film (TAC, PET and etc. ) Adhesive material Back 23 © 2010 Renesas Electronics America Inc. All rights reserved.

AG Film Details Front Plastic layer including silica or plastic beads TAC (Triacetylcellulose ) PVA (Polyvinyl alcohol ) TAC (Triacetylcellulose ) Adhesive material Back 24 © 2010 Renesas Electronics America Inc. All rights reserved.

Solution Comparisons Cost Complexity High bright backlight High Middle to heavy Very complex AG or AR film Low Good Bonding and Special overlays 28 Weight Very High Very heavy Very complex © 2010 Renesas Electronics America Inc. All rights reserved.

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 30 © 2010 Renesas Electronics America Inc. All rights reserved.

ST-NLT – Super Reflective NLT Bright ambient contrast 100 Competitor LCD 800 nits Sunlight Contrast Competitor LCD 800 nits NL 10276 BC 30 -18 C 600 nits 600 NL 10276 BC 30 -18 C 600 nits Magnified Graph 400 50 200 0 5000 10000 15000 20000 Luminance (Lx) n ST-NLT is better in bright ambient 33 © 2010 Renesas Electronics America Inc. All rights reserved. 8000 12000 16000 Luminance (Lx) 20000

Advantages of ST-NLT & SR-NLT n ST-NLT & SR-NLT products carry full manufacturer’s warranty. n NEC uses “passive” enhancements and avoids the reliability pitfalls of high brighting or overdriving lighting components by “brute force”. n While most customers shop “peak luminance” figures what they buy is “contrast”. n An NEC ST-NLT panel @ 375 nits equals a standard panel @ 810 nits. Overdriving backlights is not needed. n By increasing the peak (white) luminance, black level also rises making the panel no better in contrast. It may actually cause “wash out”. 35 © 2010 Renesas Electronics America Inc. All rights reserved.

Examples of High Bright LED Backlight Systems NL 6448 BC 20 -30 C/30 F 900 nits NL 6448 BC 33 -70 C/70 F 800 nits NL 8060 BC 21 -11 C/11 F 800 nits 36 © 2010 Renesas Electronics America Inc. All rights reserved.

LED Lifetime vs. Drive Current @ Temperature 8 m. A 70℃ 50 Relative Luminance 100 (%) 14 m. A 70℃ 20 m. A 70℃ 1 　 10 100 　　1000 Hours of Operation 40 © 2010 Renesas Electronics America Inc. All rights reserved. 　 100000 (Hrs)

Additional Comments n Power is not free l Higher power designs are typically more complex, larger & expensive. l Higher power in the form of heat. l Higher operating temperatures create opportunities for failure. l Larger mechanical “footprint” dictates larger product designs. 41 © 2010 Renesas Electronics America Inc. All rights reserved.

Summary n Properties of Light n Viewability in High Ambient Light Conditions n Solutions for High Ambient Light Conditions n Technology Overview 42 © 2010 Renesas Electronics America Inc. All rights reserved.

Renesas Electronics America Inc.