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46.2: Method to Improve Contrast in an Off‐Axis Projection Engine
Author(s) -
Bone Matthew
Publication year - 2001
Publication title -
sid symposium digest of technical papers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.351
H-Index - 44
eISSN - 2168-0159
pISSN - 0097-966X
DOI - 10.1889/1.1831770
Subject(s) - polarizer , retarder , optics , contrast ratio , high contrast , contrast (vision) , limiting , polarization (electrochemistry) , liquid crystal , optical axis , spectrum analyzer , liquid crystal on silicon , materials science , liquid crystal display , physics , computer science , chemistry , birefringence , engineering , mechanical engineering , composite material , lens (geology)
Polarization aberrations cause loss of contrast in polarizing optical systems for LCOS displays. In an off‐axis system the separation of the polarizer and analyzer allows polarization aberrations to be conveniently corrected by using retardation films. In this paper we will describe how a retarder can be used to increase the limiting contrast of an off‐axis system. Limiting contrasts of greater than 3000:1 have been achieved at an f# number of 2.65. Using this technique in combination with 45 degree reflective twisted nematic microdisplay we have demonstrated system contrasts of greater than 500:1.