349 / | HD | LIQUID CRYSTAL CELLS, ELEMENTS AND SYSTEMS |
56 | DF | PARTICULAR STRUCTURE {7} |
84 | DF | .~ Having significant detail of cell structure only {17} |
117 | DF | .~.~ Compensator or retarder (i.e., not using liquid crystal cell) {3} |
119 | .~.~.~ Multiple compensators {1} | |
120 | DF | .~.~.~.~> Including at least one with negative intrinsic birefringence |