For this thesis the results of a number of experiments on liquid crystal cells wre pertiomed. The objective of these experiments was to investigate the electro-optic characteristics of various liquid crystal cell configurations. In particular, the electrically controlled birefringence (ECB) configuration was studied in detail, in order to determine its suitability for display applications. The ECB configuration differs from commonly employed twisted nematic liquid crystal cells in that it relies on the birefiingent properties of the liquid crystal molecule rather that the induced optical activity of a twisted molecular structure to modulate the transmission of light....[ Read more ]

For this thesis the results of a number of experiments on liquid crystal cells wre pertiomed. The objective of these experiments was to investigate the electro-optic characteristics of various liquid crystal cell configurations. In particular, the electrically controlled birefringence (ECB) configuration was studied in detail, in order to determine its suitability for display applications. The ECB configuration differs from commonly employed twisted nematic liquid crystal cells in that it relies on the birefiingent properties of the liquid crystal molecule rather that the induced optical activity of a twisted molecular structure to modulate the transmission of light.

A number of liquid crystal cells of different types were obtained from Varitronix LTD, a locally based commercial manufacturer of liquid crystal displays. The samples were characterized in terms of their transmission voltage characteristic (TVC), response speed, and spectral transmission at various applied voltages.

The experimental results suggest that ECB type cells have possible advantages, in terms of response speed, over twisted nematic cells. However the electro-optic characteristics of the ECB cell show a high dependence on the angle of incidence of the transmitted light, leading to problems of narrow viewing angle and poor contrast ratio.

A double electrically controlled birefringence (D-ECB) cell was also analyzed. It was found to posses improved optical characteristics compared to single ECB cells , albeit at the expense of additional complexity and weight.