Analysis of Pico-Projection Technologies and Attempt at Design of Pico-Projection Optics Wente Yina aOptical Sciences Center, University of Arizona, 1630 E. University Blvd., Tucson, AZ USA 85719 Table of Contents Abstract ........................................................................................................................................... 1 Keywords: Projector, camera, hybrid, pico, mobile ...................................................................... 1 1. Introduction ............................................................................................................................. 1 2. Digital Light Processing (DLP) ............................................................................................... 4 2.1 Digital Micromirror Device (DMD) ................................................................................ 5 2.2 Optical Switching Principle ........................................................................................... 10 2.3 DLP Projection – Single-Chip........................................................................................ 13 2.4 DLP Projection – Two-Chip .......................................................................................... 17 2.5 DLP Projection – Three-Chip ........................................................................................ 18 2.6 Display Performance ...................................................................................................... 18 2.7 Commercial Applications ............................................................................................... 20 3. Active-Matrix Liquid-Crystal Display (AMLCD) ................................................................ 20 3.1 Liquid-Crystals (LCs) .................................................................................................... 21 3.2 Liquid Crystal Display (LCD)........................................................................................ 22 3.3 LCD Projection .............................................................................................................. 26 3.4 Display Performance ...................................................................................................... 27 3.5 Commercial Applications ............................................................................................... 27 4. Liquid Crystal on Silicon (LCOS) ......................................................................................... 28 4.1 Liquid Crystal on Silicon (LCoS) Functionality ............................................................ 28 4.2 LCoS in Projection ......................................................................................................... 29 4.3 Display Performance ...................................................................................................... 32 4.4 Commercial Application ................................................................................................ 33 5. Beam Scanning ...................................................................................................................... 33 5.1 Beam Scanning ............................................................................................................... 33 5.2 Commerical Applications ............................................................................................... 35 6. Design of Pico-Projection Optics .......................................................................................... 36 6.1 Design Considerations.................................................................................................... 36 6.2 Initial Approach.............................................................................................................. 37 6.3 Design............................................................................................................................. 39 6.4 Performance ................................................................................................................... 42 6.5 Fulfillment of Objectives ............................................................................................... 46 7. Conclusion ............................................................................................................................. 46 8. References ............................................................................................................................. 47 Table of Figures Figure 1. Magic Lantern, Late 19th Century ................................................................................... 1 Figure 2. Opaque Projector, Late 19th Century ............................................................................... 2 Figure 3. Vertical Lantern, Late 19th Century ................................................................................. 3 Figure 4. Slide Projector, Mid-20th Century ................................................................................... 3 Figure 5. Digital Projector, 21st Century ......................................................................................... 4 Figure 6. Samsung Galaxy Beam.................................................................................................... 4 Figure 7. Exploded View: DMD Pixel (Source: TI) ....................................................................... 5 Figure 8. DMD Array (Source: TI) ................................................................................................. 6 Figure 9. Potential Energy of Mirror as Function of Angle and Bias (Source:TI) ......................... 7 Figure 10. Address and Reset Sequence of a Pixel (Source: TI) .................................................... 7 Figure 11. DMD Manufacturing Process (Source: TI) ................................................................... 8 Figure 12. Details of Manufacturing Process (Source: TI) ............................................................. 9 Figure 13. DLP Cinema DMD ...................................................................................................... 10 Figure 14. DMD Optical Switching Principle (Source: TI) .......................................................... 10 Figure 15. Example of 4-bit Control Scheme (Souce: TI) ............................................................ 11 Figure 16. DMD Brightness Levels from Switching (Source: TI) ............................................... 12 Figure 17. Example 12-Degree DMD Pixel (Source: TI) ............................................................. 13 Figure 18. Single-Chip DLP Overview (Source: TI) .................................................................... 14 Figure 19. Generic Telecentric Optical System Components Using a TIR Prism (Source: TI) ... 15 Figure 20. Generic Non-Telecentric Optical System Components Using a Field Lens (Source: TI) ................................................................................................................................................. 16 Figure 21. Two-Chip Configuration ............................................................................................. 17 Figure 22. Three-Chip DLP Projection Scheme (Source: TI) ...................................................... 18 Figure 23. DMD Resolution vs. Chip Diagonal (Source: TI) ....................................................... 19 Figure 24. Modelled Optical Efficiency and Brightness vs. Resolution for DLP Three-Chip Projectors (Source: TI) .................................................................................................................. 19 Figure 25. DLP Pico-Projection Development Kit ....................................................................... 20 Figure 26. Molecular Order of Different Phases (Source: Polarization Engineering for LCD Projection) ..................................................................................................................................... 21 Figure 27. Molecular Arrangements of LCs (Source: Polarization Engineering for LCD Projection) ..................................................................................................................................... 22 Figure 28. Electro-Optical Effect (Source: Polarization Engineering for LCD Projection) ......... 23 Figure 29. 90° TN Mode, Inactive and Active, Respectively (Source: Polarization Engineering for LCD Projection) ...................................................................................................................... 23 Figure 30. Transmission vs. Voltage of the First Minimum, White TN Mode at 550nm (Source: Polarization Engineering for LCD Projection) ............................................................................. 24 Figure 31. Evolution of Polarization State, ∆nd=0.866λ and 18λ on Poincaré Sphere (Source: Polarization Engineering for LCD Projection) ............................................................................. 25 Figure 32. 90 VA TN Mode, Inactive and Active, Respectively (Source: Polarization Engineering for LCD Projection) .................................................................................................. 25 Figure 33. Basic Three-Panel LCD Setup (US Patent: US5196926A) ......................................... 26 Figure 34. HTPS LCD Wafer (Left) and Two LCD Chips (Right) .............................................. 27 Figure 35. EPSON 3LCD Pico-Projector ..................................................................................... 28