PROJECTION TYPE LIQUID CRYSTAL DISPLAY DEVICE

摘要

PURPOSE:To remarkably improve a contrast ratio by making incident parallel rays on a liquid crystal panel from the bearing where the contrast ratio is best and changing the optical axis of the light transmitted through or reflected from the panel so as to parallel with the optical axis of a projection lens. CONSTITUTION:The relation between the contrast and the visual angle theta investigated when the orientation direction of the liquid crystal panel 1 is assumed to be in the direction of an arrow A reveals that the largest contrast can be taken at 135 deg. angle phi from the orientation axis Y and theta=10 bearing. This bearing is determined by the tilt angle and cross angle of the orientation and dielectric constant, anisotropy, etc. and the majority are included in an =3-15 deg. range. The panel 2 is thereupon inclined by the prescribed angle theta with respect to the parallel rays from a light source 1 so that the parallel rays are made incident on the panel from the bearing where the max. contrast ratio is obtainable. A fiber plate 3 of which one face 3a is formed perpendicularly to the parallel rays is provided to the panel 2 in tight contact with or closely thereto. The high contrast is thereby obtd. even if the driving voltage of the picture elements of the liquid crystal panel is not increased.