Optical compensatory sheet
AssigneeFuji Photo Film Co., Ltd.
InventorYoji Ito
Life of this patent
Estimating the term…
Abstract
An optical compensatory sheet is composed of a transparent support, an orientation layer and an optically anisotropic layer. The orientation layer is a crosslinked polymer layer a surface of which has been subjected to rubbing treatment, and the optically anisotropic layer is made of a discotic liquid crystalline compound. A liquid crystal display is composed of a liquid crystal cell, a polarizing sheet arranged on each side of the cell, and the optical compensatory sheet provided between at least one side of the liquid crystal cell and the polarizing sheet. A color liquid crystal display has also the optical compensatory sheet.
Claims15
An optical compensatory sheet which comprises a transparent support, an orientation layer provided thereon and an optically anisotropic layer provided on the orientation layer which comprises a compound having a discotic structure unit, wherein the orientation layer is a crosslinked polymer layer a surface of which has been subjected to rubbing treatment.
A process for the preparation of an optical compensatory sheet which comprises the steps of:
- coating on a transparent support a coating solution of a polymer and a crosslinking agent capable of crosslinking the polymer in a solvent to form a coated layer of the polymer containing the crosslinking agent;
- heating the coated layer of the polymer to crosslink the polymer with the crosslinking agent whereby a crosslinked polymer layer is formed;
- subjecting the crosslinked polymer layer to rubbing treatment to give an orientation layer;
- coating on the orientation layer a coating solution of a compound having a discotic structure unit in a solvent to form a coated layer of the compound;
- heating the coated layer of the compound to a temperature for forming discotic nematic phase of the compound to orient the compound in the layer;
- and
- cooling the coated layer of compound to give an optically anisotropic layer.
A liquid crystal display comprising a liquid crystal cell which comprises a pair of substrates each of which is provided with a transparent electrode and twisted nematic liquid crystal sealed therebetween, a polarizing sheet arranged on each side of the liquid crystal cell, and an optical compensatory sheet provided between at least one side of the liquid crystal cell and the polarizing sheet:
- wherein the optical compensatory sheet comprises a transparent support, an orientation layer provided thereon and an optically anisotropic layer provided on the orientation layer which comprises a compound having a discotic structure unit, the orientation layer being a crosslinked polymer layer a surface of which has been subjected to rubbing treatment.
A color liquid crystal display comprising a liquid crystal cell which comprises a pair of substrates provided with a transparent electrode, a transparent electrode of picture element and color filter, and twist-oriented nematic liquid crystal sealed between the substrates, a polarizing sheet arranged on each side of the liquid crystal cell, and an optical compensatory sheet provided between at least one side of the liquid crystal cell and the polarizing sheet:
- wherein the optical compensatory sheet comprises a transparent support, an orientation layer provided thereon and an optically anisotropic layer provided on the orientation layer which comprises a compound having a discotic structure unit, the orientation layer being a crosslinked polymer layer a surface of which has been subjected to rubbing treatment.
Dependencies are inferred from the claim text.