Homeotropic alignment liquid crystal film, optical film comprising the same, and image display device

A vertical alignment liquid crystal display device comprising:

• a vertical alignment type liquid crystal cell containing a pair of substrates each having an electrode, and liquid crystal molecules to be aligned vertically to the substrate surface when no electric voltage is applied, arranged between the substrates;
• two linear polarizing films arranged above and below the liquid crystal cell;
• first optical anisotropic elements exhibiting a retardation of 1/4 wavelength in the plane, arranged between both surfaces of the liquid crystal cell and the linear polarizing films;
• and
• at least one viewing angle compensator arranged between the linear polarizing films and the first optical anisotropic elements,
• wherein said viewing angle compensator comprises a homeotropic alignment liquid crystal film comprising a liquid crystalline substance containing a side chain liquid crystalline compound having an oxetanyl group, as a constituent, aligned homeotropically on an alignment substrate while the substance is in a liquid crystal state and fixed in the homeotropic alignment by allowing the oxetanyl group to react and satisfies the following requirements:
• [7] 0 nm≦Re1≦20 nm
• [8] −500 nm≦Rth1≦−30 nm
• wherein Re1 indicates the retardation value in the plane of the homeotropic alignment liquid crystal film, Rth1 indicates the retardation value in the thickness direction of the homeotropic alignment liquid crystal film, Re1 and Rth1 are defined by Rel=(Nxl−Nyl)xd1 [nm] and Rth1 =(Nx1−Nzl)xd1 [nm], respectively wherein dl indicates the thickness of the homeotropic alignment liquid crystal film, Nx1 and Ny 1 indicate the main refractive indices in the plane of the homeotropic alignment liquid crystal film, Nz1 indicates the main refractive index in the thickness direction of the homeotropic alignment liquid crystal film, and Nz1 >Nx1 Ny1.