JP2005049792A5 - - Google Patents

Claims (9)

A liquid crystal panel including two polarizing plates, a birefringent layer A, a birefringent layer B, and a liquid crystal cell C,
The two polarizing plates are arranged so that their absorption axes are substantially orthogonal,
Between the two polarizing plates, the birefringent layer A, the birefringent layer B and the liquid crystal cell C are disposed,
The birefringent layer A has a refractive index anisotropy of the following formula (1):
The birefringent layer B has a refractive index anisotropy of the following formula (2):
The liquid crystal cell C is a liquid crystal cell in which the liquid crystal molecules are aligned substantially vertically with no voltage applied.
The wavelength dispersion characteristics (α40 (A)) of the birefringent layer A, the birefringent layer B (α40 (B)) and (α40 (C)) of the liquid crystal cell C are expressed by the following formulas (3) and ( A liquid crystal panel characterized by satisfying the condition 4).

Formula (1) nx> ny ≧ nz
Formula (2) nx ≧ ny> nz

In the formula (1) and the formula (2), nx, ny, and nz represent refractive indexes in the X-axis direction, the Y-axis direction, and the Z-axis direction in the birefringent layers A and B, respectively. The X-axis direction is an axial direction that exhibits the maximum refractive index in each in-plane direction of the birefringent layers A and B, and the Y-axis direction is relative to the X-axis direction in each of the planes. The Z-axis direction indicates a thickness direction perpendicular to the X-axis direction and the Y-axis direction.

Formula (3) α40 (B)> α40 (C)> α40 (A)
Formula (4) 1> α40 (A)

In the formula (3) and the formula (4), as shown in the following formula (5), the wavelength dispersion characteristic α40 is based on the normal direction of the birefringent layer surface or the liquid crystal cell surface as a reference (0 °). It is the ratio of retardation (Re) measured with incident light of each wavelength of 430 nm and 550 nm from a direction inclined by 40 °.

Formula (5) α40 = Re (430 nm) / Re (550 nm)
Re (430 nm): Retardation measured with incident light having a wavelength of 430 nm Re (550 nm): Retardation measured with incident light having a wavelength of 550 nm
The difference in refractive index in the plane of the birefringent layer B (Δn = nx−ny, nx and ny are the same as those in the formula (2)) is in the range of 0.005 to 0.2. The liquid crystal panel described. The liquid crystal panel according to claim 1, wherein the birefringent layer B is formed of a non-liquid crystal material. The liquid crystal according to any one of claims 1 to 3, wherein the non-liquid crystalline material is formed of at least one resin selected from the group consisting of polyamide, polyimide, polyester, polyetherketone, polyamideimide, and polyesterimide. panel. The said polarizing plate contains a polarizer and the transparent protective layer laminated | stacked on this both sides, The transparent protective layer by the side of the said liquid crystal cell C satisfy | fills the conditions of following formula (6) and following formula (7). The liquid crystal panel according to any one of 1 to 4.

Formula (6) Re = (nx−ny) d <10 nm
Formula (7) Rth = (nx−nz) d <20 nm

In the formula (6) and the formula (7), nx, ny and nz are the same as the formula (1) and the formula (2). The liquid crystal panel according to claim 1, wherein the birefringent layer B and the liquid crystal cell C are disposed adjacent to each other. The liquid crystal panel according to claim 1, wherein the birefringent layer A and the birefringent layer B are laminated in this order on one polarizing plate. The birefringent layer A is laminated on the polarizer of one polarizing plate, the birefringent layer A also serves as the transparent protective layer, and the slow axis of the birefringent layer A and the absorption axis of the polarizer The liquid crystal panel according to claim 7, wherein the birefringent layer B is laminated on the birefringent layer A. A liquid crystal display device comprising the liquid crystal panel according to claim 1.