Vertical alignment type liquid crystal display device with viewing angle characteristics improved by disposing optical plates

A liquid crystal display device comprising:

• first and second polarizers in cross Nichol configuration;
• a liquid crystal cell disposed between the first and second polarizers and establishing vertical alignment in a state of no voltage application;
• and
• an odd number of three or more optical films having optical anisotropy and disposed between the liquid crystal cell and the first polarizer,
• wherein:
• a retardation of the liquid crystal cell is equal to or larger than 550 nm and equal to or smaller than 1500 nm;
• and
• each of the optical films satisfies nx>ny≧nz where nx, ny and nz are x-, y- and z-components of a refractive index in which an x-axis is an in-plane slow axis azimuth of each of the optical films, a y-axis is an in-plane azimuth perpendicular to the x-axis and a z-axis is a direction perpendicular to a film surface, an in-plane retardation is equal to or larger than 30 nm and equal to or smaller than 300 nm, a thickness direction retardation is equal to or larger than 50 nm and equal to or smaller than 300 nm, an angle between an in-plane slow axis of the optical film disposed nearest to the first polarizer and an absorption axis of the first polarizer is equal to or larger than 45° and equal to or smaller than 135°, and the slow axes of mutually adjacent optical films are perpendicular to each other.

A liquid crystal display device comprising:

• first and second polarizers in cross Nichol configuration;
• a liquid crystal cell disposed between the first and second polarizers and establishing vertical alignment in a state of no voltage application;
• and
• a first optical film disposed between the liquid crystal cell and the first polarizer and having optical anisotropy;
• a second optical film disposed between the first optical film and the liquid crystal cell and having optical anisotropy;
• and
• a third optical film disposed between the second polarizer and the liquid crystal cell and having optical anisotropy;
• wherein:
• each of the first to third optical films satisfies nx>ny≧nz where nx, ny and nz are x-, y- and z-components of a refractive index in which an x-axis is an in-plane slow axis azimuth of each of the optical films, a y-axis is an in-plane azimuth perpendicular to the x-axis and a z-axis is a direction perpendicular to a film surface, an in-plane retardation is larger than 0 nm and equal to or smaller than 300 nm, and a thickness direction retardation is equal to or larger than 50 nm and equal to or smaller than 300 nm;
• a slow axis of the first optical film is parallel to an absorption axis of the first polarizer;
• a slow axis of the second optical film and a slow axis of the third optical film are perpendicular to each other;
• and
• an angle between an in-plane axis of the second optical film and an absorption axis of the first polarizer is in a range between 75° and 105°.

A liquid crystal display device comprising:

• a liquid crystal cell establishing vertical alignment in a state of not voltage application;
• first and second polarizers in cross Nichol configuration and sandwiching the liquid crystal cell;
• a first optical film disposed between the liquid crystal cell and the first polarizer and having optical anisotropy;
• a second optical film disposed between the first optical film and the liquid crystal cell and having optical anisotropy;
• a third optical film disposed between the second polarizer and the liquid crystal cell and having optical anisotropy;
• and
• a fourth optical film disposed between the third optical film and the second polarizer and having optical anisotropy,
• wherein:
• each of the first to fourth optical films satisfies nx>ny≧nz where nx, ny and nz are x-, y- and z-components of a refractive index in which an x-axis is an in-plane slow axis azimuth of each of the optical films, a y-axis is an in-plane azimuth perpendicular to the x-axis and a z-axis is a direction perpendicular to a film surface, and the first to fourth optical films have approximately same optical characteristics;
• a slow axis of the first optical film is approximately parallel to an absorption axis of the first polarizer;
• a slow axis of the first optical film is approximately perpendicular to a slow axis of the second optical film;
• a slow axis of the fourth optical film is approximately parallel to an absorption axis of the second polarizer;
• and
• a slow axis of the third optical film is approximately perpendicular to a slow axis of the fourth optical film.