Digital Displays Cathode Ray Tubes Flat Panel Displays Lecture 7: Displays Digital Displays Cathode Ray Tubes Flat Panel Displays 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Summary of What We Have Learned Ohm’s Law Resistor Combinations What a Diode Does Transistors as Switches Op-Amp Configurations 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Ohm’s Law Kirchoff’s Voltage Law Kirchoff’s Current Law Series Equivalent Parallel Equivalent 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Diode V-I Characteristic For ideal diode, current flows only one way Real diode is close to ideal Ideal Diode 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Op-Amp 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Ideal Op-Amp Continued Bandwidth is also infinite. Thus, an ideal op-amp works the same at all frequencies. 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Golden Rules for Op-Amps The output attempts to do whatever is necessary to make the voltage difference between the two inputs zero. (Negative Feedback is Required) The inputs draw no current. 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Op-Amp Configurations Buffer or Voltage Follower No voltage difference between the output and the input Draws no current, so it puts no load on the source Used to isolate sources from loads 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Op-Amp Configurations Non-Inverting Amplifier Note that this formula is different in the lab write up 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Op-Amp Configurations Inverting Op-Amp 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Binary Numbers 0 0000 1 0001 2 0010 3 0011 4 0100 5 0101 6 0110 7 0111 8 1000 9 1001 10 1010 11 1011 128 + 0 + 32 + 16 + 0 + 4 + 2 + 1 = 183 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Astable and Monostable Multivibrators What are they good for? Astable: clock, timing signal Monostable: a clean pulse of the correct height and duration for digital system 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics 555 Timer The correct frequency is given by Note the error in the figure 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

From What We Have Seen So Far, How Would We Make a Display? LEDs in some kind of an array How to arrange them? How to control them? What is the purpose of the display? How much should it cost? 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics 7 Segment Displays Binary inputs are converted to a decimal number display by turning on a set of 7 LEDs 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics 7 Segment Displays Common cathode at the right and common anode at the left 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics 7 Segment Displays This is the 0-9 counting circuit you will be building in the lab. Note that it has to count and then convert the binary to show decimal 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Displays Applications 7 Segments are excellent for displaying simple alphanumeric information – multimeters, clocks, etc. More complex displays are needed to show images – computer displays, televisions, etc. 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

2 Minute Quiz Name________________ Sec___ Give three examples of electronic displays What is a pixel? True or False Blue light is higher energy than red light Most colored light is not produced directly Solid state light is generally produced directly 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Dividing Images Into Pixels Second image is blown up many times to show the individual pixels 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Dividing Images Into Pixels The second image is blown up a bit less but pixels are still obvious 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Dividing Images Into Pixels The second image is sampled more coarsely 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Dividing Images Into Pixels Black and white or single color displays are easier to implement 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Dividing Images Into Pixels Images can be constructed by scanning across them, line-by-line The original image is encoded in this manner (e.g. this is the way a scanner or copier works) by, say, starting at the upper left and going line by line to the lower right 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Plasma Displays Large, bright, flat panel display View from a wide angular range Designed for HDTV Available from many companies 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Plasma Displays High voltage discharge creates high energy photons (UV) that excite phosphors 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Plasma Displays Note the patterns of the address and display electrodes To excite an address, both voltages must be applied 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Plasma Displays Fujitsu ALIS display More complex electrodes but better use of surface area for display 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Plasma Displays Discharge region geometry and voltages 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Displays: CRT In a CRT, an electron beam excites the phosphor rather than a UV photon The beam is directed to a spot on the surface using sweep plates 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Displays: CRT Three separate electron guns are required to produce a color picture 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Displays: CRT At the left is the layout of the mask and phosphors At the right is the scanning sequence 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Displays: CRT A large variety of configurations are used by manufacturers Look carefully at the screen of your TV 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Image From My TV 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Same Image Enlarged to Show Screen 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Same Image Enlarged Further 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Same Image Enlarged Further 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Unsmoothed Image Enlarged Further 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Displays: Early TV Allen Dumont B.S.E.E. RPI 1924 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Displays: Dumont Developed the first practical CRT (previous versions lasted only 10s of hours) First company to market home TV receiver in 1938 (previous slide) Dumont network until 1956 – It could not compete with radio networks (poorly funded) Broadcast Jackie Gleason, first sporting events, but shows were bought by big 3 networks Dumont was one of broadcastings first millionaires 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Where Will You See This Material Again? 7 Segment Displays: Many courses CRT: ECSE-2100 Fields and Waves I Digital Imaging: ECSE-4540 Voice and Image Processing RF Circuitry: ECSE-4060 Communications Circuits Plasmas: ECSE-4320 Plasma Engineering Optics: ECSE-4630 Lasers and Optical Engineering and ECSE-4640 Optical Communications and Integrated Optics 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Introduction to Engineering Electronics Imaging Tools Mathworks Image Processing Toolboxes http://www.mathworks.com/products/image 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor

Charged Particle Accelerators Fermilab Medical Accelerator 17 September 201817 September 2018 Introduction to Engineering Electronics K. A. Connor