Liquid crystal display device

A liquid crystal display device of a fringe field switching (FFS) type, comprising:

• a first polarizer;
• a first protective layer;
• a first substrate;
• a first optical alignment film that is a photoisomeric or photo-Fries rearrangement optical alignment film;
• a horizontal-alignment liquid crystal layer including liquid crystal molecules;
• a second optical alignment film that is a photoisomeric or photo-Fries rearrangement optical alignment film;
• a second substrate including a signal electrode and an opposite electrode opposite the signal electrode;
• a second protective layer;
• a second polarizer;
• and
• backlight in this order, wherein
• the first protective layer and the second protective layer satisfy the relationship of nx=ny≥nz, where nx and ny represent main refractive indices in an in-plane direction, and nz represents a main refractive index in an out-of-plane direction,
• an in-plane retardation of each of the first optical alignment film and the second optical alignment film is greater than or equal to 1 nm,
• given that R1 is a thickness-direction retardation of each of the first protective layer and the second protective layer and that R2 is the in-plane retardation of each of the first optical alignment film and the second optical alignment film,
• R1 and R2 satisfy the relationship R1≤0.040R22−2.2R2+44.0,
• the liquid crystal layer has a negative dielectric anisotropy,
• a transmission axis of the second polarizer is perpendicular to an initial alignment direction of the liquid crystal molecules in a plan view,
• no retardation layer is interposed between the first polarizer and the first protective layer, between the first protective layer and the first substrate, between the second substrate and the second protective layer, and between the second protective layer and the second polarizer, and
• at least one of the in-plane retardation and the thickness-direction retardation of the first optical alignment film and the second optical alignment film is greater than or equal to 10 nm.

A liquid crystal display device of a fringe field switching (FFS) type, comprising:

• a first polarizer;
• a first protective layer;
• a first substrate;
• a first optical alignment film that is a photoisomeric or photo-Fries rearrangement optical alignment film;
• a horizontal-alignment liquid crystal layer including liquid crystal molecules;
• a second optical alignment film that is a photoisomeric or photo-Fries rearrangement optical alignment film;
• a second substrate including a signal electrode and an opposite electrode opposite the signal electrode;
• a second protective layer;
• a second polarizer;
• and
• backlight in this order, wherein
• the first protective layer and the second protective layer satisfy the relationship of nx=ny≥nz, where nx and ny represent main refractive indices in an in-plane direction, and nz represents a main refractive index in an out-of-plane direction,
• an in-plane retardation of each of the first optical alignment film and the second optical alignment film is greater than or equal to 1 nm,
• given that R1 is a thickness-direction retardation of each of the first protective layer and the second protective layer and that R2 is the in-plane retardation of each of the first optical alignment film and the second optical alignment films,
• R1 and R2 satisfy the relationship R1≥0.040R22−2.2R2+44.0,
• the liquid crystal layer has a negative dielectric anisotropy,
• a transmission axis of the second polarizer is parallel to an initial alignment direction of the liquid crystal molecules in a plan view,
• no retardation layer is interposed between the first polarizer and the first protective layer, between the first protective layer and the first substrate, between the second substrate and the second protective layer, and between the second protective layer and the second polarizer, and
• at least one of the in-plane retardation and the thickness-direction retardation of the first optical alignment film and the second optical alignment film is greater than or equal to 10 nm.