Liquid crystal display device with particular angle between optical axis of optically anisotropic material and observation direction

A liquid crystal display device, comprising:

• a twisted nematic liquid crystal display cell including a pair of spaced apart opposed substrates with electrodes selectively disposed thereon and a twisted nematic liquid crystal material disposed in the space between the substrates;
• a pair of polarizing plates disposed on opposite sides of the liquid crystal cell, one of which defines a display screen;
• and
• at least one layer of an optically anisotropic substance disposed between the liquid crystal cell and one of the pair of polarizing plates;
• the display screen having a rear edge as viewed from a user and an observation direction which is both in the plane of the display screen and substantially perpendicular to the rear edge thereof, the observation direction being the direction of the projection in the plane of the display screen of the direction from which a user of said display device most frequently views said display screen, the device being constructed and arranged to have a viewing angle with respect to the observation direction at which the display will have acceptable contrast to accurately convey information to a user, the angle between the direction of the optical axis of the optically anisotropic substance layer and the observation direction of the display device being set at a predetermined angle to produce substantially bilateral symmetry of the contrast distribution with respect to the observation direction as the user moves in the direction of the viewing angle .beta. between a projection of the direction of viewing by the user in the plane of the display screen and the observation direction or in the direction of the viewing angle .alpha. between the direction of viewing of the user and an axis perpendicular to the observation direction and the plane of the display screen.