Mobile Phone Displays Display technologies: History Prevailing Technologies 3D Touch Screens Future

Summary LCD history Present technologies Power consumption problem Technologies in detail (emissive & reflective) 3D screens Touchscreens iPhone 4 Retina display and IPS Future preditions 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

Remember Your First Phone? In 1997 Nokia 2110 was the hottest piece out there Beautiful LCD display: 4 rows with 13 characters I do SMS! ≈ 24h battery ≈ smart phone battery life today 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

LCD Founding History 1/2 Austrian botanist Friedrich Reinitzer first observed Liquid Crystal in 1888 Cholesteryl benzoate White at 145 celsius, clear at 179 celsius 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

LCD Founding History 2/2 Otto Lehman Physics PHD examined the double refraction effect Thus the name liquid and crystal (Fliessende Krystalle) From then on LC’s were popular field of study 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

1960’s – the Race is ON USA - LCD has great potential but CRTs are selling Japan - let’s make some calculators UK - BBC let’s make some watches 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

CMOS + LCD = ♥♥♥ Same operational frequency & voltage Both small in size = A good match Seven segment display > 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

First TFT 14” Monitor A major milestone was reached in 1988 when a 14-in active-matrix (AM) thin-film-transistor (TFT) display was demonstrated by Sharp 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

Present Technologies Phone display sizes 2” - 4” Resolution 320x240 – 960x640, DPI Emissive (emit light) – LCDs: light from lightsource through optics – LEDs & OLEDs: convert energy directly into light Reflective (reflect light) – E-ink, Mirasol – Electrofluidic Display (work in progress) Touch screens in all technologies 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

Present Technologies Usage AMOLED: Nokia N8, Samsung Galaxy S, HTC, Nexus 1 LCD & SLCD: iPhone, HTC, Nexus 1, Windows 7 phone OLED: not many yet, Kyocera W41K Hard to find info or graphs Not so big differences. The beauty is in your mind ;) Android phones /10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

Power Consumption Problem 13/10/2010 Displays increase in size, brightness and color > more power is needed Power consumption & management becomes more important Advanced Display Technologies - Mobile DisplaysSami Reinilä

LCD Energy Inefficiency Working principle: LCDs modulate polarized light to create images Initial polarization loses 50% of the light Additional layers lose ≈ 40% more LCD display shows 5-10% of the original light = The need for strong backlight 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

LED Backlit LCD Panel 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

LEDs Electrofluorescense Good contrast Fast response times Energy consumption ≈ 40% - 80% of LCDs White images can use more energy than LCD! LifeSpan is limited 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

LEDs 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

OLED Advanced LED Small, generates less heat, durable… Glowing pickle video 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

OLED devices are coming 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

Reflective Technology: Displays Of The Future? Reflective technologies are the most power savy of the emerging display technologies Bistable = ‘memory’ = intelligent refresh for only changed areas. Still areas retain image with very little power. E-ink, Mirasol, Electrofluidic Displays 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

E-ink Plastic film laminated with circuits Bistable Reflects ambient light Energy Efficient and viewable in sunlight Colors still in development Slow response time 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

Amazon Kindle E-ink 600 x 800 pixel resolution at 167 ppi, 16-level gray scale “A single charge lasts for up to a month with wireless off. Keep wireless always on and it lasts for up to 3 weeks” 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

Mirasol Bistable, fast and energy efficient Already used in couple of devices Explanation video 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

Electrofluidic Display Still in development but looks promising Energy efficient Fast Durable Colourfull … 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

Electrofluidic Display new approach which leverages use of high- performance pigments used in traditional printing process video 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

3D is here 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

3D devices – Nintendo 3DS 13/10/ inch widescreen LCD display, enabling 3D view without the need for special glasses 800x240 pixel resolution (400 pixels are allocated for each eye to enable 3D viewing) One inner camera and two outer cameras with 640x480 (0.3 Mega) pixel resolution. Advanced Display Technologies - Mobile DisplaysSami Reinilä

3D devices – Samsung Mobile 3D AMOLED 13/10/ inch 1024xRGBx600 LVDSContrast: :1 Color gamut: NTSC 100% Advanced Display Technologies - Mobile DisplaysSami Reinilä

3D devices – NTT DoCoMo & CEATEC 13/10/2010 3D display with haptic feedback Stereographic cameras for stylus position detection More info Advanced Display Technologies - Mobile DisplaysSami Reinilä

Touchscreens Both work as a layer on top of display, they can be used with any type of display technology “Elograph” Developed by Dr. Sam Hurst in 1971 Main technologies in mobiles: Resistive and Capasitive 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

Resistive Touchscreens Resistive screens use two extremely thin layers below the glass that are pressed together when the screen is touched 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

Capasitive Touchscreens Capacitive touchscreens work by transferring a small electrical charge from the screen to your finger and detecting the region where the charge is removed 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

Resistive vs. Capacitive The difference between the two means that resistive screens can be touched with any object, like a stylus, while capacitive screens need to make contact with your body (conductive material), usually through your finger Matter of opinion which one is better General opinion (and mine) seems to favor capacitive 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

iPhone 4 Retina Display In place switching LED backlight TFT LCD 3.5” widescreen capasitive multi touch 960-by-640-pixel resolution at 326 DPI PPI 800:1 contrast ratio Fingerprint-resistant oleophobic coating on front and back 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

In Place Switching Developed by Hitachi in 1996 crystal molecules move parallel to the panel plane instead of perpendicular to it Viewing angle ≈ 170 degrees Used in iPhone4 and iPad More info 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

iPhone 4 Retina Display Apple’s Retina display info Apple’s Retina display info Retina display review video Retina display review video 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

Future Predictions LCDs will change into OLEDs 3D is coming allready Reflective technologies are likely to become the next BIG thing after OLED Hybrid technologies: Qi pixel? Power consumption is going down while resolution, brightness, contrast and gamut continue to enhance 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä

Thank You Questions? Check notes for additional info & links 13/10/2010Advanced Display Technologies - Mobile DisplaysSami Reinilä