TIDUEE5A October   2018  – May 2022

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagrams
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 DLP3030-Q1
      2. 2.3.2 DLPC120-Q1
      3. 2.3.3 TMS320F28023
    4. 2.4 System Design Theory
      1. 2.4.1 Head-up Display Parameter Design and Tradeoffs
        1. 2.4.1.1 Field of View and Eyebox
        2. 2.4.1.2 Resolution
        3. 2.4.1.3 Virtual Image Distance
      2. 2.4.2 Picture Generation Unit Design Decisions
        1. 2.4.2.1 Etendue Efficiency Match
        2. 2.4.2.2 Aperture Size: Selecting f/# of Optics
        3. 2.4.2.3 Thermal Design
        4. 2.4.2.4 LED Selection Summary
      3. 2.4.3 Design Summary
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Required Hardware and Software
      1. 3.1.1 Hardware
      2. 3.1.2 Software
    2. 3.2 Testing and Results
      1. 3.2.1 Test Setup
      2. 3.2.2 Test Results
  9. 4Design Files
    1. 4.1 Schematics
    2. 4.2 Bill of Materials
    3. 4.3 PCB Layout Recommendations
      1. 4.3.1 Layout Prints
    4. 4.4 Cadence Project
    5. 4.5 Gerber Files
    6. 4.6 Assembly Drawings
  10. 5Software Files
  11. 6Related Documentation
    1. 6.1 Trademarks
  12. 7Terminology
  13. 8Revision History

2.4.2 Picture Generation Unit Design Decisions

After the number of required lumens has been determined from HUD eyebox and FOV parameters, as discussed in Section 2.4.1, details about the PGU design can be considered. Two key factors that influence PGU lumens output are the LED part selection and the optical aperture f/# in the illumination path and projection lens.

For a DLP technology based PGU, high brightness projection LEDs are often required. While larger LEDs will output more lumens, it does not necessarily mean they are the best choice at a system level. It is important to choose the best LEDs for every application. The key considerations for LED choice include:

  • Etendue efficiency match
  • f/# tradeoff on brightness and contrast
  • Thermal solution