A liquid-crystal display device comprising:na liquid-crystal cell which comprises:na pair of substrates disposed to face each other having an electrode on at least one of them, the electrode capable of forming an electric field containing a component running in parallel to the substrate, anda liquid-crystal layer, of which alignment is controlled, disposed between the pair of substrates; anda pair of polarizing plates disposed to sandwich the liquid-crystal cell therebetween,wherein at least one of the pair of polarizing plates comprises a polarizing element and a thermoplastic-resin film which comprises a lactone ring-having polymer as a major ingredient and satisfies the following formulas (I) and (II):n−3≦Re(630)≦4, and −12≦Rth(630)≦−1.7  (I)n|Re(400)−Re(700)|≦10, and 1≦|Rth(400)−Rth(700)|≦15  (II)nwherein Re(λ) means retardation (nm) in plane at a wavelength λ, nm; and Rth(λ) means retardation (nm) along the thickness direction at a wavelength λ nm.
›2.↳ 1The liquid-crystal display device of claim 1, wherein a polarizing plate disposed at the backlight side, at least, is said polarizing plate comprising…d2
The liquid-crystal display device of claim 1, wherein a polarizing plate disposed at the backlight side, at least, is said polarizing plate comprising the thermoplastic-resin film.
›3.↳ 1The liquid-crystal display device of claim 1, wherein a polarizing plate disposed at the displaying plane side, at least, is said polarizing plate com…d2
The liquid-crystal display device of claim 1, wherein a polarizing plate disposed at the displaying plane side, at least, is said polarizing plate comprising the thermoplastic-resin film.
›4.↳ 1The liquid-crystal display device of claim 1, wherein both of polarizing plates disposed at the backlight side and the displaying plane side are said …d2
The liquid-crystal display device of claim 1, wherein both of polarizing plates disposed at the backlight side and the displaying plane side are said polarizing plates comprising the thermoplastic-resin film.
›5.↳ 1The liquid-crystal display device of claim 1, wherein Re{T} and Rth{T} (T means the temperature (° C.) at which the data is measured) of the thermopl…d2
The liquid-crystal display device of claim 1, wherein Re{T} and Rth{T} (T means the temperature (° C.) at which the data is measured) of the thermoplastic-resin film at a wavelength of 550 nm satisfy the following formulas (III) and (IV):n|Re{50}−Re{25}|<5,  (III)n|Rth{50}−Rth{25}|<10.  (IV)
›6.↳ 1The liquid-crystal display device of claim 1, wherein Re[H] and Rth[H] (H means the relative humidity (%) at which the data is measured) of the thermo…d2
The liquid-crystal display device of claim 1, wherein Re[H] and Rth[H] (H means the relative humidity (%) at which the data is measured) of the thermoplastic-resin film at a wavelength of 550 nm satisfy the following formulas (V) and (VI):n|Re[80]−Re[10]|<5,  (V)n|Rth[80]−Rth[10]|<10.  (VI)
›7.↳ 1The liquid-crystal display device of claim 1, wherein the lactone ring-having polymer has a repetitive structure unit to be constructed by polymerizat…d2+6
The liquid-crystal display device of claim 1, wherein the lactone ring-having polymer has a repetitive structure unit to be constructed by polymerization of at least one selected from (meth)acrylates, hydroxyl group-containing monomers, unsaturated carboxylic acids and monomers of the following formula (2),
›8.↳ 7The liquid-crystal display device of claim 7, wherein Re{T} and Rth{T} (T means the temperature (° C.) at which the data is measured) of the thermopl…d3
The liquid-crystal display device of claim 7, wherein Re{T} and Rth{T} (T means the temperature (° C.) at which the data is measured) of the thermoplastic-resin film at a wavelength of 550 nm satisfy the following formulas (III) and (IV):n|Re{50}−Re{25}|<5,  (III)n|Rth{50}−Rth{25}|<10; and  (IV)nwherein Re[H] and Rth[H] (H means the relative humidity (%) at which the data is measured) of the thermoplastic-resin film at a wavelength of 550 nm satisfy the following formulas (V) and (VI):n|Re[80]−Re[10]|<5,  (V)n|Rth[80]−Rth[10]|<10.  (VI)
›9.↳ 7The liquid-crystal display device of claim 7, wherein the lactone ring-having polymer has a lactone ring structure of the following formula (1):d3
The liquid-crystal display device of claim 7, wherein the lactone ring-having polymer has a lactone ring structure of the following formula (1):
›10.↳ 7The liquid-crystal display device of claim 7, wherein the polarizing plate comprising the thermoplastic-resin film comprises on the opposite side of t…d3
The liquid-crystal display device of claim 7, wherein the polarizing plate comprising the thermoplastic-resin film comprises on the opposite side of the thermoplastic-resin film with respect to the polarizing element a cellulose acylate film, a polycarbonate film, or a norbornene-based film.
›11.↳ 7The liquid-crystal display device of claim 7, wherein the polarizing plate comprising the thermoplastic-resin film comprises the thermoplastic-resin f…d3
The liquid-crystal display device of claim 7, wherein the polarizing plate comprising the thermoplastic-resin film comprises the thermoplastic-resin films on both sides of the polarizing element.
›12.↳ 7The liquid-crystal display device of claim 7, wherein the product of the thickness d (μm) of the liquid-crystal layer and the refractive anisotropy Î…d3
The liquid-crystal display device of claim 7, wherein the product of the thickness d (μm) of the liquid-crystal layer and the refractive anisotropy Δn thereof, Δn·d is from 0.2 to 1.2 μm.
›13.↳ 7The liquid-crystal display device of claim 7, wherein the lactone ring-having polymer has a repetitive structure unit obtained by polymerization of at…d3
The liquid-crystal display device of claim 7, wherein the lactone ring-having polymer has a repetitive structure unit obtained by polymerization of at least monomers of the formula (2) wherein the monomers of formula (2) are at least one of styrene and α-methylstyrene.
›14.↳ 1The liquid-crystal display device of claim 1, wherein the lactone ring-having polymer has a lactone ring structure of the following formula (1):d2+1
The liquid-crystal display device of claim 1, wherein the lactone ring-having polymer has a lactone ring structure of the following formula (1):
›15.↳ 14The liquid-crystal display device of claim 14, wherein Re{T} and Rth{T} (T means the temperature (° C.) at which the data is measured) of the thermop…d3
The liquid-crystal display device of claim 14, wherein Re{T} and Rth{T} (T means the temperature (° C.) at which the data is measured) of the thermoplastic-resin film at a wavelength of 550 nm satisfy the following formulas (III) and (IV):n|Re{50}−Re{25}|<5,  (III)n|Rth{50}−Rth{25}|<10; and  (IV)nwherein Re[H] and Rth[H] (H means the relative humidity (%) at which the data is measured) of the thermoplastic-resin film at a wavelength of 550 nm satisfy the following formulas (V) and (VI):n|Re[80]−Re[10]|<5,  (V)n|Rth[80]−Rth[10]|<10.  (VI)
›16.↳ 1The liquid-crystal display device of claim 1, wherein the lactone ring-having polymer in the thermoplastic-resin film is from 50 to 100% by mass.d2
The liquid-crystal display device of claim 1, wherein the lactone ring-having polymer in the thermoplastic-resin film is from 50 to 100% by mass.
›17.↳ 1The liquid-crystal display device of claim 1, wherein the lactone ring-having polymer has a weight-average molecular weight of from 1,000 to 2,000,000…d2
The liquid-crystal display device of claim 1, wherein the lactone ring-having polymer has a weight-average molecular weight of from 1,000 to 2,000,000.
›18.↳ 1The liquid-crystal display device of claim 1, wherein the polarizing plate comprising the thermoplastic-resin film comprises on the opposite side of t…d2
The liquid-crystal display device of claim 1, wherein the polarizing plate comprising the thermoplastic-resin film comprises on the opposite side of the thermoplastic-resin film with respect to the polarizing element a cellulose acylate film, a polycarbonate film, or a norbornene-based film.
›19.↳ 1The liquid-crystal display device of claim 1, wherein the polarizing plate comprising the thermoplastic-resin film comprises the thermoplastic-resin f…d2
The liquid-crystal display device of claim 1, wherein the polarizing plate comprising the thermoplastic-resin film comprises the thermoplastic-resin films on both sides of the polarizing element.
›20.↳ 1The liquid-crystal display device of claim 1, wherein the product of the thickness d (μm) of the liquid-crystal layer and the refractive anisotropy Î…d2
The liquid-crystal display device of claim 1, wherein the product of the thickness d (μm) of the liquid-crystal layer and the refractive anisotropy Δn thereof, Δn·d is from 0.2 to 1.2 μm.
›21.↳ 1The liquid-crystal display device of claim 1, wherein the mass reduction ratio of the lactone ring-having polymer, as measured within a range of from …d2
The liquid-crystal display device of claim 1, wherein the mass reduction ratio of the lactone ring-having polymer, as measured within a range of from 150 to 300° C. through dynamic TG analysis, is at most 1%.
›22.↳ 1The liquid-crystal display device of claim 1, wherein the thermoplastic-resin film is disposed on the liquid-crystal cell through an adhesive layer.d2
The liquid-crystal display device of claim 1, wherein the thermoplastic-resin film is disposed on the liquid-crystal cell through an adhesive layer.
›23.↳ 1The liquid-crystal display device of claim 1, wherein the liquid crystal display device is free from a layer having an optical characteristic between …d2
The liquid-crystal display device of claim 1, wherein the liquid crystal display device is free from a layer having an optical characteristic between the thermoplastic-resin film and the liquid crystal cell.
›24.↳ 1The liquid-crystal display device of claim 1, wherein |Re(400)−Re(700)|≦3.d2
The liquid-crystal display device of claim 1, wherein |Re(400)−Re(700)|≦3.
