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

2.4.2.3 Thermal Design

In general, HUD systems have a low transmission percentage, due to only a small percentage of HUD lumens being reflected by the windshield to the driver’s eyebox. A lot of electrical power is required to overcome this low transmission and to generate enough brightness in day-time driving conditions. Higher LED power consumption requires robust thermal designs in order to dissipate the heat and keep the LED junction temperatures at reasonable levels.

Additionally, HUDs are typically enclosed inside the vehicle dashboard with minimal airflow. This exacerbates the issue with higher power consumption, since the heat is recycled and further increases the temperature of all components. LEDs are sensitive at higher temperatures, so this results in an power-to-brightness efficiency decrease as well.

Therefore, it’s important to select LEDs which are efficient in order to simplify the thermal solution and total HUD volume.