mobile phone displays display technologies: history prevailing technologies 3d touch screens future

Mobile Phone Displays

Display technologies:History

Prevailing Technologies3D

Touch ScreensFuture

Advanced Display Technologies - Mobile Displays

Summary

• LCD history• Present technologies• Power consumption problem• Technologies in detail (emissive &

reflective)• 3D screens• Touchscreens• iPhone 4 Retina display and IPS• Future preditions

13/10/2010 Sami 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



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



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



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



CMOS + LCD = ♥♥♥

• Same operational frequency & voltage

• Both small in size• = A good match

Seven segment display >



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



Present Technologies

• Phone display sizes 2” - 4”• Resolution 320x240 – 960x640, 100-326 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



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 2010


http://www.androphones.com/2010-android-phones.php


Power Consumption Problem

13/10/2010

• Displays increase in size, brightness and color > more power is needed

• Power consumption & management becomes more important

Sami 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



LED Backlit LCD Panel



LEDs

• Electrofluorescense• Good contrast• Fast response times• Energy consumption ≈

40% - 80% of LCDs• White images can use

more energy than LCD!• LifeSpan is limited



LEDs



OLED

• Advanced LED• Small, generates less

heat, durable…• Glowing pickle video


http://www.youtube.com/watch?v=JUbpm8CdesY&feature=player_embedded


OLED devices are coming



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



E-ink

• Plastic film laminated with circuits

• Bistable• Reflects ambient light• Energy Efficient and

viewable in sunlight• Colors still in

development• Slow response time



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”



Mirasol

• Bistable, fast and energy efficient• Already used in couple of devices• Explanation video


http://www.mirasoldisplays.com/mobile-display-imod-technology


Electrofluidic Display

• Still in development but looks promising• Energy efficient• Fast• Durable• Colourfull• …



Electrofluidic Display

• new approach which leverages use of high-performance pigments used in traditional printing process

• video


http://www.youtube.com/watch?v=4bxqX0T-l_0&feature=player_embedded


3D is here



3D devices – Nintendo 3DS

13/10/2010

• 3.53-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.

Sami Reinilä


3D devices – Samsung Mobile 3D AMOLED

13/10/2010

• 7.01 inch• 1024xRGBx600• LVDSContrast:

30.000:1• Color gamut: NTSC

100%

Sami Reinilä


3D devices – NTT DoCoMo & CEATEC

13/10/2010

• 3D display with haptic feedback

• Stereographic cameras for stylus position detection

• More info

Sami Reinilä

http://www.engadget.com/2010/10/06/ntt-docomos-touchable-3d-display-prototype-seamlessly-integrate/


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



Resistive Touchscreens

• Resistive screens use two extremely thin layers below the glass that are pressed together when the screen is touched



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



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



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



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


http://www.hometheatermag.com/gearworks/606gear/


iPhone 4 Retina Display

• Apple’s Retina display info

• Retina display review video


http://www.apple.com/iphone/features/retina-display.html



http://www.youtube.com/watch?v=GO40Xm-U6JE&feature=related

http://www.youtube.com/watch?v=GO40Xm-U6JE&feature=related


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



Thank You

Questions?Check notes for additional info & links


mobile phone displays display technologies: history prevailing technologies 3d touch screens future

Documents

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