The reflective liquid crystal display device uses only one polarizing film (10) but achieves display of bright white and achromatic color with high contrast. The twisting angle of a nematic liquid crystal is set to 45° to 90°, and the retardation value of a liquid crystal layer (17) is set to ΔnLC·dLC=0.20 µm to 0.30 µm. Two retardation films (11a,11b) are configured with a structural component having small chromatic dispersion in refractive index anisotropy and a z coefficient from 03 to 1.0. Retardation values of these two retardation films are set to RF1=0.23 µm to 0.28 µm, and RF2=0.13 µm to 0.18 µm. When the angle of an absorption axis direction of the polarizing film is denoted by φP, and the angles of retardation axes directions of the two retardation films are denoted by φF1 and φF2, a set of Formulae φP=75°-195°, φP-φF1=95°- 115°, and φP-φF2=155°-175° are satisfied.

A reflection type liquid crystal display device having a wide viewing angle, and capable of assuring a light utilization factor at or above a certain value for bright display even when conditions of an external light are varied is provided. The reflection type liquid crystal display device comprises (a) a liquid crystal cell comprising an upper substrate, a lower substrate and a liquid crystal layer between the substrates,(b)a polarizing film provided in a side of the upper substrate in the liquid crystal cell, (c) light reflecting means provided in a side of the lower substrate in the liquid crystal cell; and (d) an optical member provided between the polarizing film and the liquid crystal cell, and having a retardation axis when it is viewed in the normal direction. An angle between an absorption axis of the polarizing film and the retardation axis of the optical member is within a range of about 88° to about 92° or about -2° to about +2°. A retardation value in relation to the normal direction of the optical member is within a range of about 50 nm to about 500 nm.

A reflection type liquid crystal display device having a wide viewing angle, and capable of assuring a light utilization factor at or above a certain value for bright display even when conditions of an external light are varied is provided. The reflection type liquid crystal display device comprises (a) a liquid crystal cell comprising an upper substrate, a lower substrate and a liquid crystal layer between the substrates,(b)a polarizing film provided in a side of the upper substrate in the liquid crystal cell, (c) light reflecting means provided in a side of the lower substrate in the liquid crystal cell; and (d) an optical member provided between the polarizing film and the liquid crystal cell, and having a retardation axis when it is viewed in the normal direction. An angle between an absorption axis of the polarizing film and the retardation axis of the optical member is within a range of about 88° to about 92° or about -2° to about +2°. A retardation value in relation to the normal direction of the optical member is within a range of about 50 nm to about 500 nm.

A normally white twisted nematic liquid crystal display is provided for outputting improved viewing characteristics which are defined by high contrast ratios and reduced inversion. The display includes both positive (2,4) and negative (4,13) retardation films, the negative films being biaxial and defined by n_x ≻ n_y ≻ n_z in certain embodiments where the "z" direction is substantially perpendicular to the film plane and the "x" and "y" directions are substantially parallel to the film plane. By providing the positive and biaxial negative retarders with specific retardation values and/or ratios, improved viewing characteristics are provided. According to other embodiments, a positive and a negative (uniaxial or biaxial) retarder may be provided on only one side of the liquid crystal layer.

A normally white liquid crystal display is provided with a positively birefringent uniaxial retardation film having a retardation value of from about 100 - 200 nm. The retardation film is provided on one side of the liquid crystal layer, the liquid crystal being sandwiched between a pair of orientation or buffing films which orient the liquid crystal molecules adjacent thereto in predetermined directions. The optical axis of the retardation film is rotated from about 2° - 20°, most preferably from about 6° - 10° relative to the buffing direction on the opposite side of the liquid crystal layer. This rotation of the retardation film optical axis allows for the high contrast ratio viewing zone of the display to be shifted vertically into either the positive or negative vertical viewing region depending upon the direction of rotation of the retardation film optical axis. Alternatively, biaxial retardation films having similar retardation values may be utilizied according to the teachings of this invention.

A normally white twisted birefringent liquid crystal display having first (7) and second (9) retardation films having retardation values of about 80 - 200 nm on opposite sides of a liquid crystal layer (5) for the purpose of expanding the viewing angles of the display. Also, the viewing zone of this normally white display can be shifted vertically by rotating the optical axes (R_F,R_R) of the retardation films so as to position the viewing zone away from an inversion area.

A birefringent film in which molecules oriented in a direction parallel to the film plane and molecules oriented in the direction of the thickness of the film are present in a mixed state; a process for producing the birefringent film, which comprises laminating a resin film on one or both sides thereof with a shrinkable film, thereby preparing a laminate, and then heat stretching the laminate, thereby performing stretching treatment of the resin film while imparting to the resin film the ability to shrink in the direction crossing the stretching direction; a retardation film which uses at least one birefringent film and has refractive indexes, n_x and n_y, in two directions parallel to the plate plane and crossing each other at right angles and a refractive index, n_z, in the direction of the thickness of the plate, said refractive indexes n_x, n_y, and n_z satisfying the following equation:



${\text{0 < (n}}_{\text{x}}{\text{-n}}_{\text{z}}{\text{)/(n}}_{\text{x}}{\text{-n}}_{\text{y}}\text{) < 1}$



provided that n_x>n_y; an elliptically polarizing plate comprising a laminate of the retardation film with a polarizing plate; and a liquid crystal display comprising a liquid crystal cell and a polarizing plate disposed at least on one side of said liquid crystal cell through the retardation film.

A liquid crystal display comprising a liquid crystal cell and a polarizing sheet is disclosed, in which (A) at least one film having light transmission properties, said film (A) having at least one optic axis at an angle of not more than 45° with the normal thereof or satisfying the relationship:

η_TH - (η_MD + η_TD)/2 > 0

wherein η_TH is a refractive index inthe normal direction; η_MD is a refractive index in the machine direction; and η_TD is a refractive index in the transverse direction,

and (B) at least one uniaxially stretched film of a polymer having a positive intrinsic birefringence and light transmission properties are inserted between the liquid crystal cell and the polarizing sheet. Viewing angle dependence of retardation of the display can be eliminated, and the display has markedly widended viewing angle.