US 7,804,565 B2 · Cellulose acylate film, optical compensation film, polarizing plate, and liquid crystal display device

Abstract

A novel optical compensation film is disclosed. The film comprises a transparent film having a ratio Re/Rth(450 nm) of Re and Rth at 450 nm of 0.4 to 0.95 times as large as Re/Rth(550 nm) at 550 nm, having Re/Rth(650 nm) at 650 nm of 1.05 to 1.93 times as large as Re/Rth(550 nm), and having Rth at 550 nm ranging from 70 nm to 400 nm, where “Re” is an in-plane retardation and “Rth” is a thickness-direction retardation; and an optically anisotropic layer having an in-plane optical anisotropy, formed of a composition comprising a liquid-crystalline compound, in which molecules of the liquid-crystalline compound are fixed in an alignment state, wherein the direction of orthogonal projection, onto a plane of the transparent film, of a mean orientation direction of molecular symmetry axes of the liquid-crystalline compound at the interface on the transparent film side is 45° with respect to the in-plane slow axis of the transparent film.

Claims9

Dependent claims

An optical compensation film comprising:

a transparent film having a ratio Re/Rth(450 nm) of Re and Rth at 450 nm of 0.4 to 0.95 times as large as Re/Rth(550 nm) at 550 nm, having Re/Rth(650 nm) at 650 nm of 1.05 to 1.93 times as large as Re/Rth(550 nm), and having Rth at 550 nm ranging from 70 nm to 400 nm, where “Re” is an in-plane retardation and “Rth” is a thickness-direction retardation;
and
an optically anisotropic layer having an in-plane optical anisotropy, formed of a composition comprising a liquid-crystalline compound, in which molecules of the liquid-crystalline compound are fixed in an alignment state,
wherein the direction of orthogonal projection, onto a plane of the transparent film, of a mean orientation direction of molecular symmetry axes of the liquid-crystalline compound at the interface on the transparent film side is 45° with respect to an in-plane slow axis of the transparent film.

1 more element

A liquid crystal display device comprising:

a liquid crystal cell comprising a pair of substrates having at least on either one of which electrodes formed thereon, and a liquid crystal layer held between the pair of substrates, comprising a nematic liquid crystal material, molecules of which being oriented almost in parallel with the surfaces of the pair of substrates in a non-driven state, and having a product Δn·d ranging from 0.1 to 1.5 μm of the thickness d (μm) and the refractive index anisotropy Δn;
a first and second polarizing films arranged while placing the liquid crystal cell in between;
and
a transparent film disposed between the liquid crystal cell and at least one of the first and second polarizing film,
the transparent film having a ratio Re/Rth(450 nm) of Re and Rth at 450 nm of 0.4 to 0.95 times as large as Re/Rth(550 nm) at 550 nm, having Re/Rth(650 nm) at 650 nm of 1.05 to 1.93 times as large as Re/Rth(550 nm), and having Rth at 550 nm ranging from 70 nm to 400 nm, where “Re” is an in-plane retardation and “Rth” is a thickness-direction retardation.

2 more elements

Dependencies are inferred from the claim text.

Cellulose acylate film, optical compensation film, polarizing plate, and liquid crystal display device

Life of this patent

Cellulose acylate film, optical compensation film, polarizing plate, and liquid crystal display device

Life of this patent

Abstract

Claims9