DLPA083B june   2019  – april 2023 DLP2000 , DLP2010 , DLP230KP , DLP230NP , DLP3010 , DLP3310 , DLP4620S-Q1 , DLP4710 , DLP471TP , DLP500YX , DLP5500 , DLP5530S-Q1 , DLP5531-Q1 , DLP5533A-Q1 , DLP6500FLQ , DLP6500FYE , DLP650LNIR , DLP670S , DLP7000 , DLP7000UV , DLP9000 , DLP9000X , DLP9000XUV , DLP9500 , DLP9500UV

 

  1.   Abstract
  2.   Trademarks
  3. 1Purpose and Scope
    1. 1.1 Limitations
    2. 1.2 Acronyms Used in This Document
  4. 2On-State Fill Factor
  5. 3Window Properties
  6. 4Mirror Diffraction Efficiency
    1. 4.1 Mirror Flatness
    2. 4.2 Mirror Diffraction Efficiency
    3. 4.3 Diffraction Efficiency with Mismatched Illumination and Projection f-numbers
  7. 5Mirror Reflectivity
  8. 6Estimating Overall DMD Efficiency
  9. 7References
  10. 8Revision History

6 Estimating Overall DMD Efficiency

Overall optical efficiency can be estimated using Equation 3.

Equation 3. EfficiencyDMD = transmissionwindow × efficiencyfillfactor × efficiencydiffraction × reflectivitymirror × transmissionwindow

where

  • efficiencyfillfactor is the fractional mirror coverage (on-state mirrors) as viewed from the illumination direction
  • transmissionwindow is single-pass window transmission including two anti-reflection surfaces. This term is accounted for twice because light travels through the window twice.
  • efficiencydiffraction is the mirror array diffraction efficiency which can include effects of non-flat mirrors
  • reflectivitymirror is the mirror reflectivity including mirror scatter

The photopic numbers shown in Table 6-1 assume a source with a flat power spectrum with wavelengths of 420 nm–680 nm. More accurate results can be obtained for a given light source by multiplying the spectral diffraction efficiency by the actual source spectrum.

Table 6-1 Total Photopic Average Efficiency Calculation(1)
DMD Pitch (μm) Tilt Angle (deg) f-number Diff. Eff. On-State Fill Window Transmission (Double Pass) Mirror Refl. Total Eff.
13.68 12 2.4 89% 92% 96% 89% 70%
10.8 12 2.4 87% 92% 96% 89% 68%
9.0 14.5 2.0 89% 97% 96% 89% 72%
7.6/7.56 12 2.4 84% 94% 96% 89% 67%
5.4 17 1.7 86% 93% 96% 89% 68%
5.4 17 2.4 80% 93% 96% 89% 64%
(1) The values in this table are approximate. For specific values, see the device-specific DMD data sheet.