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Introduction to HB LEDs and Color Science

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Introduction of the basics behind color science, the basic operation of LEDs and HB LEDs.

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Introduction to HB LEDs and Color Science

  1. 1. Introduction to HB LEDs and Color Science <ul><li>Source: Cypress </li></ul>
  2. 2. Introduction <ul><li>Purpose </li></ul><ul><li>This training module will introduce the basics behind color science, the industry terminology used when describing colors, the basic operation of LEDs, and how HB LEDs are used. </li></ul><ul><li>Outline </li></ul><ul><li>Introduction to the science of colors </li></ul><ul><li>Introduction to LEDs and its working principle </li></ul><ul><li>Introduce one particular type of LED, the high brightness LED (HB LED) and how HB LEDs are sued for common applications. </li></ul><ul><li>Content </li></ul><ul><li>24 pages </li></ul><ul><li>Learning Time </li></ul><ul><li>20 minutes </li></ul>
  3. 3. How W e S ee
  4. 4. Color Spectrum
  5. 5. Relaxation Oscillator Circuit <ul><li>Everything we see = Luminance + Chromaticity </li></ul><ul><li>Luminance = Brightness </li></ul><ul><li>Chromaticity = Color </li></ul>
  6. 6. Frequency Measurement <ul><li>W. David Wright and John Guild perform a number of experiments on color perception in the 1920s </li></ul><ul><li>International Commission on Illumination (CIE) standardized the color spectrum in 1931 </li></ul><ul><li>CIE 1931 Color Space defines the chromatic spectrum using a 2D map </li></ul>
  7. 7. CIE 1931 Color Space Chromaticity Diagram
  8. 8. Tristimulus Values
  9. 9. Evolution of Lighting
  10. 10. LEDs Applications <ul><li>Architectural lighting </li></ul><ul><li>Status indicators </li></ul><ul><li>Traffic lights and signals </li></ul><ul><li>General signage </li></ul><ul><li>Flashlight </li></ul><ul><li>Aircraft cockpits, submarine and ship bridges lighting </li></ul><ul><li>Automobile (brake, turn signals, dome lights) </li></ul><ul><li>LCD TV and display backlighting </li></ul><ul><li>Stage lighting equipment </li></ul>
  11. 11. LED Advantages <ul><li>Energy efficient </li></ul><ul><li>Long lasting </li></ul><ul><li>Lower system cost </li></ul><ul><li>Design flexibility </li></ul><ul><li>No dimming effect </li></ul><ul><li>Ability to focus direction </li></ul><ul><li>Durable </li></ul><ul><li>Fast light up </li></ul>
  12. 12. LED Disadvantages <ul><li>Currently more expensive </li></ul><ul><li>New technology = New design challenges </li></ul><ul><ul><li>Constant current drive </li></ul></ul><ul><ul><li>Temperature-dependence </li></ul></ul><ul><ul><li>No standardized “binning” </li></ul></ul>
  13. 13. LED Definitions <ul><li>LED = Lighting Emitting Diode </li></ul><ul><li>Semiconductor chip encased in a solid plastic lens that emits light </li></ul><ul><li>Color emitted depends on the composition and condition of the semiconductor material used </li></ul><ul><ul><li>Infrared </li></ul></ul><ul><ul><li>Visible </li></ul></ul><ul><ul><li>Near Ultraviolet </li></ul></ul>
  14. 14. LED Compon ents
  15. 15. Diode Basics
  16. 16. Colors of LED <ul><li>Electrons emit photons when moving to lower orbitals </li></ul><ul><li>Band gap determines the amount of energy emitted </li></ul>
  17. 17. Colors of LED cont’d
  18. 18. Controlling LEDs LED brightness and use dependent on the current flow through the diode.
  19. 19. HB LEDs vs. Standard LEDs Source: iSuppli (Solid State Lighting) One (1) candela = 12.75 lumens < 350 mA > 50 lumens High Brightness (HB) < 30 mA < 50 lumens Standard Current Luminous Flux LED Type
  20. 20. High Brightness LEDs vs. High Power LEDs <ul><li>High Power LED: > 1 Watt </li></ul><ul><li>High Brightness LED: > 50 Lumens </li></ul>
  21. 21. HB LED Applications
  22. 22. Covering the Color Needs
  23. 23. Color Mixing <ul><li>Using a few colored LEDs to cover a large range of colors </li></ul><ul><li>Requires ability to tune individual LEDs </li></ul><ul><li>Alternating the forward current causes dimming </li></ul>
  24. 24. Conclu s ion <ul><li>Colorime try is the science of representing colors as numerical values </li></ul><ul><li>The tristimulus values X, Y, and Z are a representation of a color ’s luminance and chromaticity </li></ul><ul><li>The CIE 1931 Chromaticity Diagram is a two-dimensional representation of all the colors visible to the average human </li></ul><ul><li>LEDs are simply diodes incased in plastic that emit photons </li></ul><ul><li>Different materials used to create different diodes emit different colors </li></ul><ul><li>High Brightness LE Ds are simply LEDs that can produce more luminance </li></ul><ul><li>HB LEDs are quickly replacing incandescent, fluorescent, and halogen lights in applications ranging from architectural lighting, general signage applications, and LCD backlights. </li></ul>
  25. 25. Additional Resource <ul><li>For ordering the Cypress HB LED Controller, please call our sales hotline </li></ul><ul><li>For additional inquires contact our technical service </li></ul><ul><li>Hotline </li></ul><ul><li>For more product information go to </li></ul><ul><li>http://www.cypress.com/EZ-Color </li></ul>

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