Lecture 1 6.976 Flat Panel Display Devices Outline Overview of 6.976 Overview Flat Panel Display Devices Course website http://hackman.mit.edu Reading Assignment: Article by Alt and Noda, IBM Journal of Research and Development, Vol. 42, No. ¾, May/July 1998, p.315 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 1
Information Capacity of Displays (BARS Billions of Addressable Retinal Stimuli) Alt, et al, IBM 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 2
Information Capacity of Displays (Pixel Count) Display Devices, No. 21, Spring 2000, p. 41 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 3
Evolution of Notebook Displays Kai Schleupen, IBM Research 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 4
High Resolution Displays a-si AMLCDs Kai Schleupen, IBM Research 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 5
Applications of Flat-Panel Displays SMALL FORMAT Medical Defibrillator (mono) Personal Digital Assistant (mono) Car Navigation & Entertainment (color) LARGE FORMAT Courtesy of PixTech Desktop Monitor (color) Large Screen Television (color) 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 6
Applications of Flat Panel Displays Trium Handset New Nokia Handset 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 7
How Do Displays Work? Electronic display is a Language Translator that converts Time Sequential Electrical Signals into spatially and temporally configured light signal (images) useful to the viewer. Translation Function carried out by two intertwined sub-functions Display element address wherein electrical signals are appropriately routed to the various display elements (similar to memory addressing) Display element (pixel) converts the routed electrical signal at its input into light of certain wavelength and intensity (inverse of image capture) 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 8
Classifications of Displays by Technology Displays could be classified into two broad categories Photon Generator (Emissive Displays) Photon Modulation (Light Valve Displays) Emissive Displays generate photons from electrical excitation of the picture element (pixels) Light Valve Displays spatially and temporally modulate the intensity pattern of the picture elements (pixels) 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 9
Emissive Displays Displays that generate photons when an electrical signal is applied between the terminals Energy causes excitation followed by excitation relaxation Hole + Electron recombination Exciton formation and annihilation Relaxation of excited ions or radicals in a plasma The different types of Luminescence differ mostly in the way the holes and electrons are generated holes and electrons are generated by UV in a phosphor which then recombine and generate red, green or blue light Photoluminescence or Phosphorescence holes and electrons injected by pn junction or generated by impact ionization or excitation which then recombine and generate red, green or blue light Electroluminescence holes and electrons generated by electron beam which then recombine and generate red, green or blue light Cathodoluminescence 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 10
Light Valve Displays Displays that spatially and temporally modulate ambient lighting or broad source of light and redirect to the eye. Display element spatially changes the intensity of plane wave of light using Refraction Reflection Polarization change These displays are part of a broader class of devices called Spatial Light Modulators which in general operate though local Amplitude change Polarization change Phase change Intensity change 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 11
Overview of 6.976 6.976: Introductory subject to flat panel devices and systems. Human Visual System and Perception How do we convert light into visual signals? Image capture & Visual Pathway Emissive Flat Panel Displays How do we convert electrical signals to light and images? Photon generator displays Light Valve Flat Panel Displays How do we re-direct a broad light source into images? Photon modulation displays Display Drivers and Large Area Electronics How do we route the electrical signal to the picture element (pixel)? Picture element (pixel) selection 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 12
Human Visual System The Retina and Photo-Receptors (Cones & Rods) Visual Pathway Color Perception Tristhimus Color Coordinates Color Transformations 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 13
Human Eye Spectral Response 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 14
Emissive Displays Theory of luminescence Photoluminescence and Phosphorescence (holes and electrons generated by UV) Electroluminescence (holes and electrons generated by pn junction injection or impact ionization or excitation) Cathodoluminescence (holes and electrons generated by electron beam) Case Studies of Emissive Flat Panel Displays Electroluminescence (Light Emitting Diode, Organic- Light Emitting Devices & In-organic ELectroluminescent Displays) Cathodoluminescence (Cathode Ray Tube, Vacuum Florescent Display, Field Emission Display) Photoluminescence (PLasma Displays) 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 15
Light Valve Displays Theory of Spatial Light Modulators Amplitude change Polarization change Phase change Intensity change Case studies of Light Valve Displays Liquid Crystal Displays (active & passive matrix) Deformable Mirror Displays Membrane Mirror Displays Electrophoretic Displays (E-Ink) 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 16
Display Drivers and Large Area Electronics Time sequential electrical signals meant for conversion need to be routed to the appropriate picture element (pixel) Typical flat panel displays are two-dimensional arrays of picture elements (pixels) that are individually addressed from the perimeter or the back. Methods of scanning include Sequential addressing (CRTs) Row scan addressing (AMLCDs and PMLCDs) Random addressing (stroke mode CRTs) Row scanning of a matrix of pixels requires picture elements with non-linear Luminance Voltage (L- V) characteristics. If the Luminance-Voltage characteristics is linear (or is non-linear enough), a non linear switch element is required in series with the pixel. Examples are Amorphous silicon thin film transistor Poly-crystalline silicon thin film transistors 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 17
Lecture, Problem Set and Lab Schedule S M T W R F S 2/8 Intro 2/9 2/10 2/11 2/12 2/13 Vision 2/14 2/15 Vision 2/16 2/17 2/18 2/19 2/20 No Class 2/21 2/22 Luminescence 2/23 2/24 2/25 2/26 2/27 Luminescence 2/28 3/1 EL 3/2 3/3 3/ 4 3/ 5 3/ 6 EL 3/ 7 3/ 8 CL 3/ 9 3/ 10 3/ 11 3/ 12 3/ 13 PL 3/ 14 3/ 15 SLM 3/ 16 3/ 17 3/ 18 3/ 19 3/ 20 LC 3/ 21 3/ 22 LC 3/ 23 3/ 24 3/ 25 3/ 26 3/ 27 No Class 3/ 28 3/ 29 No Class 3/ 30 3/ 31 4/1 4/ 2 4/ 3 PMLCD 4/4 4/ 5 Drivers 4/ 6 4/ 7 4/ 8 4/ 9 4/ 10 Backplanes 4/ 11 4/ 12 Backplanes 4/ 13 4/ 14 4/ 15 4/16 4/ 17 No Class 4/ 18 4/ 19 OTFT 4/ 20 4/ 21 4/ 22 4/ 23 4/ 24 AMLCD 4/ 25 4/ 26 Reflective LCD 4/ 27 4/ 28 4/ 29 4/ 30 5/1 DMD, DLP 5/ 2 5/ 3 MMD 5/ 4 5/ 5 5/ 6 5/ 7 5/ 8 Micro-Display 5/ 9 5/ 10 3D/Printing 5/ 11 5/ 12 5/ 13 5/ 14 5/ 15 5/ 16 5/ 17 5/ 18 5/ 19 Legend No Assignment No Class Homework Laboratory Design Project 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 18
Display Devices Built in Lab These are devices that will be built in the laboratory sessions EL Backlight Liquid Crystal Display 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 19
Cathode Ray Tube Cathode CRT Display Phosphor Screen Anode Courtesy of PixTech Electrons beam boiled off a metal by heat (thermionic emission) is sequentially scanned across a phosphor screen by magnetic deflection. The electrons are accelerated to the screen acquiring energy and generate light on reaching the screen (cathodoluminescence) 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 20
Thin-CRT FED Display Cathode Anode Courtesy of PixTech In principle similar to the CRT except that it uses a twodimensional array of electron sources (field emission arrays) which are matrix addressed allowing the vacuum package to be thin 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 21
Thin-CRTs An Early Candescent 13.2 SVGA ThinCRT Display Courtesy of Candescent Technologies 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 22
Plasma Displays Weber, SID 00 Digest, p. 402. Electrons are accelerated by voltage and collide with gasses resulting in ionization and energy transfer Excited ions or radicals relax to give UV photons UV photons cause hole-electron generation in phosphor and visible light emission 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 23
Plasma Displays Weber, SID 00 Digest, p. 402. 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 24
Electroluminescent Display 12µm 1280 x 1024 AMEL Display 2k AMEL Development Courtesy of Planar Technologies 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 25
Organic Light Emitting Diode Rajeswaran et al., SID 00 Digest, p. 974 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 26
Digital Mirror Device Applied voltage deflects Mirror and hence direct light Courtesy of Texas Instruments 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 27
Digital Mirror Device Courtesy of Texas Instruments 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 28
Liquid Crystal Displays Liquid Crystals rotate the plane of polarization of light when a voltage is applied across the cell Courtesy of Silicon Graphics 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 29
Color Active Matrix LCD Courtesy of Silicon Graphics 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 30
22.2 -QUXGAW AMLCD (Bertha) Kai Schleupen, IBM Research 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 31
22.2 -QUXGA-W AMLCD (Bertha) Kai Schleupen, IBM Research 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 32
Bistable Cholesteric LCDs Pixel States P/2 Color Reflective Planar State Black State 4 Pixels Courtesy of Kent Displays 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 33
1/4 VGA, Full Color Ch-LCD Photographed in Sunlight Courtesy of Kent Displays 6.976 Flat Panel Display Devices-Spring 2001 Lecture 1 34