Liquid crystal display device

A liquid crystal display device comprising:

• a liquid crystal layer taking on a roughly vertically aligned state in a black display state;
• first and second polarizing plates placed to face each other via the liquid crystal layer so that transmission axes of the polarizing plates are orthogonal to each other;
• at least one first phase plate placed between the liquid crystal layer and the first polarizing plate and/or the second polarizing plate;
• at least one second phase plate placed between the at least one first phase plate and the first polarizing plate or the second polarizing plate whichever is farther from the at least one first phase plate;
• and
• an illuminator for illuminating the liquid crystal layer with light via either the first polarizing plate or the second polarizing plate,
• wherein thickness-direction retardation of the liquid crystal layer in the black display state, Δn·d1c (where Δn is a birefringence of the liquid crystal layer and d1c is a thickness of the liquid crystal layer), satisfies a relationship 200 nm≦Δn·d1c≦500 nm,
• the at least one first phase plate has biaxial optical anisotropy, and a slower axis of the at least one first phase plate is substantially parallel to the transmission axis of the first polarizing plate or the second polarizing plate whichever is on the same side as the at least one first phase plate with respect to the liquid crystal layer, and
• thickness-direction retardation (Rth1=(nx−nz)·d) and in-plane retardation (Re=(nx−ny)·d) of the at least one first phase plate satisfy relationships 100 nm≦Rth1+1.9·Re≦500 nm and Re<190 nm where nx, ny and nz are refractive indices of the at least one first phase plate in the direction of the slower axis, in the direction of a faster axis and in the direction of a thickness (d), respectively, the faster axis being in a plane including the slower axis and parallel to the liquid crystal layer and being orthogonal to the slower axis.

A liquid crystal display device comprising:

• a liquid crystal layer taking on a roughly vertically aligned state in a black display state;
• first and second polarizing plates placed to face each other via the liquid crystal layer so that transmission axes of the polarizing plates are orthogonal to each other;
• at least one first phase plate placed between the liquid crystal layer and the first polarizing plate and/or the second polarizing plate;
• at least one second phase plate placed between the at least one first phase plate and the first polarizing plate or the second polarizing plate whichever is farther from the at least one first phase plate;
• and
• an illuminator for illuminating the liquid crystal layer with light via either the first polarizing plate or the second polarizing plate,
• wherein thickness-direction retardation of the liquid crystal layer in the black display state, Δn·d1c (where Δn is a birefringence of the liquid crystal layer and d1c is a thickness of the liquid crystal layer), satisfies a relationship 200 nm≦Δn·d1c≦500 nm,
• the at least one first phase plate has biaxial optical anisotropy, and a slower axis (x axis) of the at least one first phase plate is substantially parallel to the transmission axis of the first polarizing plate or the second polarizing plate whichever is on the same side as the at least one first phase plate with respect to the liquid crystal layer, and
• thickness-direction retardation (Rth1=(nx−nz)·d) and in-plane retardation (Re=(nx−ny)·d) of the at least one first phase plate satisfy relationships 100 nm≦Rth1+1.9·Re≦500 nm and nx>ny>nz where nx, ny and nz are refractive indices of the at least one first phase plate in the direction of the slower axis, in the direction of a faster axis and in the direction of a thickness (d), respectively, the faster axis being in a plane including the slower axis and parallel to the liquid crystal layer and being orthogonal to the slower axis.