Modeling transflective LCD illumination systems

Joshua J. Kim, R. John Koshel

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations


Transflective LCDs use both reflective and transmissive elements in order to remain readable under strong ambient light conditions through light recycling. A transflective LCD illumination system based on the dual cell gap structure is simulated and compared to a regular LCD to assess contrast performance under influence of ambient light in terms of a user viewable image. Previous studies in the literature have not developed full system model simulations that include image output, glare and light leakage due to both microstructure geometry and polarization. The overall contrast performance is evaluated for a wide range of ambient source strengths using three different contrast metrics (ANSI, NIST and a proposed illuminance distribution contrast method). Three ambient source types (planar Lambertian, planar isotropic and a parabolic reflector) are used to simulate both office and outdoor environments. The sources were selected to simulate both specular and diffuse components of ambient lighting. The proposed contrast performance relationship between the different components of polarization leakage, microstructure leakage, and glare for both ambient and nominal backlight sources was verified in the Monte Carlo simulation models. The proposed contrast performance relationship provides a new understanding into the proper design of transflective LCD devices as control of the dark feature or black level illuminance is highly important. The proposed distribution contrast method proved to be more accurate and sensitive in assessing contrast performance than the NIST and ANSI methods. The transflective system was able to attain an average contrast performance of 10X beyond that of the regular LCD.

Original languageEnglish (US)
Title of host publicationInternational Optical Design Conference 2010
StatePublished - 2010
Externally publishedYes
EventInternational Optical Design Conference 2010 - Jackson Hole, WY, United States
Duration: Jun 13 2010Jun 17 2010

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherInternational Optical Design Conference 2010
Country/TerritoryUnited States
CityJackson Hole, WY


  • Displays
  • Illumination design
  • Liquid crystal devices

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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