Optical sheet for a super twisted nematic display related applications

摘要

An optical sheet has a uni-axial film and a liquid crystal film. A retardation of the uni-axial film is between 150 nm and 650 nm. The liquid crystal film is placed on one side of the uni-axial film, such that a down view contrast ratio of the optical sheet is at least greater than 2, and a down view range of the optical sheet is greater than 30 degrees.