optical displays module thomas d. anthopoulos exss group department of physics and centre for...

Optical Displays Module

Thomas D. AnthopoulosEXSS Group

Department of Physics and Centre for Plastic ElectronicsImperial College London

LondonOctober 2014

Thomas D. Anthopoulos

Course DescriptionCourse Description (5 ECTS)This module will offer an introduction to the field of optical displays, covering the technologies currently in use and those expected to feature in the next generation of display technologies. The module will offer a short introduction the different kinds of optical displays available, and will briefly discuss the current driving forces governing market trends. The lectures will discuss the way in which the human eye operates and how it affects the way in which we perceive optical displays. The course will then move on to cover all of the physical and technical properties associated with understanding and characterizing optical displays, such as luminous power, luminous efficiencies and understanding the 1931 CIE colour space standard etc. The lectures will cover the various technical approaches applied in the manufacture of different optical displays; the physical structure of the displays as well as their operating principles will be discussed in detail, including a summary of the main areas we need to address for future display technologies.

Activities PercentageHomework 20

Presentation 10Middle Term Exam 20

Final Exam 50

Grading



Aim of the course

Aim

Investigate properties of optical display technologies:

- currently in use - and those being developed


Aim of the course

Aim

Investigate properties of optical display technologies:

- currently in use - and those being developed

What you will discover

How to quantitatively asses the quality of an optical display

Main problems researchers need to solve for each technology


Content

• Quantifying important display properties

• Colourimetry and cathode ray tubes

• Non-emissive displays - Liquid crystals

- Electrophoretic- Electrochromic - Micromirrors

• Emissive displays - Plasma, vacuum fluorescent

- Field emission - Thin film electroluminescence - Inorganic LEDs

• Organic LED based displays

• Thin-Film Transistors and circuits

xx

Backlighting

Polarising filter

Polarising filter

Glass substrate

Transparent electrodes

Alignment layer

Liquid crystals

Colour filter

Glass substrateSpacer


Alignment layer

Backlighting

Polarising filter

Polarising filter

Glass substrate


Alignment layer

Liquid crystals

Colour filter



Alignment layer


• Introduction

- What are optical displays used for?

- What drives the displays market?

- What types of display are there?

What are the important properties of an optical display?

How can important display properties be quantified?

Quantifying important display properties


What are optical displays used for?

Four main applications:• Computer monitors • TVs• Mobile Phones / iPads etc. • Notebook, PCs etc.


What are optical displays used for?

Point of salesShop and transport signs

AdvertisingCash machines

WatchesPhones

CamcordersDigital cameras

E-readers

Wearable displaysSmart cards

Projection TVsHome appliances

(DVD, video and Hi Fi)Games / toys

Entertainment

Portable

Information

Future

Also:

Instrument panels (cars, planes, trains)

Industrial machines

Interfaces

Medical imaging

PDAs Education

Many more…..

Four main applications:• Computer monitors • TVs• Mobile Phones / iPads etc. • Notebook, PCs etc.


What drives the displays market?

One of largest technology markets, and growing rapidly….

Size of market: >>$100 billion

Trends:

• Increasing share of flat panel displays - Flat panels have the vast majority of the market

• Flat panel display market dominated by LCDs

• Many technologies co-exist


What drives the displays market?

Why is displays market growing?

• Initially: Desire to replace bulky cathode ray tubes (CRT)

• Currently: Increase in number of portable devices (phones, PDA etc) with displays

- Display size, weight, ruggedness and battery life

• Information explosion! - Mobile internet etc


What types of display are out there?

Cathode Ray Tube

Liquid Crystal

Non-emissiveEmissive

Flat Panel Displays


Liquid crystal displays

Backlighting

Polarising filter

Polarising filter

Glass substrate


Alignment layer

Liquid crystals

Colour filter



Alignment layer

Backlighting

Polarising filter

Polarising filter

Glass substrate


Alignment layer

Liquid crystals

Colour filter



Alignment layer A YX A YXHow can these be improved?


Electrophoretic displays

-- ---- - -

+ + + +++ ++

Transparent fluid

Positively charged white pigment chips

Negatively charged black pigment chips


Electrophoretic displays

-- ---- - -

+ + + +++ ++

Transparent fluid

Positively charged white pigment chips

Negatively charged black pigment chips

Newspaper

Electrophoretic display with extremely low power consumption

(e-ink)

Could these really replace paper?



Cathode Ray Tube

Liquid Crystal

Electro-chromic

Electro-phoretic


Flat Panel Displays

Micro-mirror



Cathode Ray Tube

Plasma

Liquid Crystal

Electro-chromic

Electro-phoretic


Flat Panel Displays

Micro-mirror



Cathode Ray Tube

Plasma Electroluminescence

Liquid Crystal

Thin film EL

Electro-chromic

Electro-phoretic

Inorganic LEDs

Field emission

Vacuum fluorescent

Inorganic


Flat Panel Displays

Micro-mirror


Thin film electroluminescent displays

Display, driver and power supply all thin enough to fit inside credit card!

(Pe

likon

)

Can higher brightnesses be achieved?

Electrodes

Electrodes

Thin film phosphor / ceramic laminate

~200 mm



Cathode Ray Tube


Liquid Crystal

Thin film EL

Electro-chromic

Electro-phoretic

Inorganic LEDs

Field emission

Vacuum fluorescent

Inorganic


Flat Panel Displays

Micro-mirror



Cathode Ray Tube


Liquid Crystal

Thin film EL Organic LEDs

Electro-chromic

Electro-phoretic

Inorganic LEDs

Field emission

Vacuum fluorescent

OrganicInorganic


Flat Panel Displays

Micro-mirror


Organic LEDs

nC8H17H17C8nC8H17H17C8

Organic molecules or polymers


Organic LEDs

Wide viewing angle

nC8H17H17C8nC8H17H17C8

(Pioneer)

Flexible / wearable displays

What limits display efficiencies and lifetimes?

Philips

Organic molecules or polymers



Cathode Ray Tube


Liquid Crystal

Thin film EL Organic LEDs

Electro-chromic

Electro-phoretic

Inorganic LEDs

Field emission

Vacuum fluorescent

OrganicInorganic


Flat Panel Displays

Micro-mirror

Many different types and many questions to be answered!

optical displays module thomas d. anthopoulos exss group department of physics and centre for...

Documents

field of optical displays

displays market

types of display

future display technologies

important properties

technical properties

anthopoulos thomas

main applications