Liquid crystal device and electronic equipment using the same

A liquid crystal device comprising a liquid crystal cell having a layer of nematic liquid crystal twisted to within the range of 180.degree. to 360.degree. and a pair of substrates on which are formed electrodes for applying a voltage to said nematic liquid crystal layer and which are disposed in an opposing manner in a form that sandwiches said nematic liquid crystal layer therebetween;

• a pair of polarizing plates disposed on either side of said liquid crystal cell in a sandwich form;
• an optically anisotropic substance provided between said liquid crystal cell and at least one polarizing plate of said pair of polarizing plates;
• and
• voltage application means capable of selecting at least three voltages to be applied between said pair of substrates;
• wherein:
• said liquid crystal cell and said optically anisotropic substance satisfy the relationships of Equations 7 and 8 below:
• .DELTA.n.multidot.d.gtoreq.1(.mu.m) Equation 7
• 15.5.times..alpha..sup.2 -40.times..alpha.+25.1.ltoreq.R-.DELTA.n.multidot.d.ltoreq.15.5.times..DEL TA..sup.2 -40.times..alpha.+25.8(.mu.m) Equation 8
• where:
• .DELTA.n.multidot.d is the product of the optical anisotropy .DELTA.n of said nematic liquid crystal layer and the thickness d of said nematic liquid crystal layer;
• R is the sum of the products .DELTA.nj.multidot.dj of the optical anisotropy .DELTA.nj of a jth (where j is an integer) layer of said optically anisotropic substance and the thickness dj of the jth layer of said optically anisotropic substance, taken from a first layer to an ith layer (where i is an integer greater than or equal to j) when i layers of said optically anisotropic substance are used;
• and a is the ratio of the optical anisotropy of said optically anisotropic substance at a wavelength of 450 nm with respect to the optical anisotropy of said optically anisotropic substance at a wavelength of 590 nm.

A liquid crystal device comprising a liquid crystal cell having a layer of nematic liquid crystal twisted to within the range of 180.degree. to 360.degree. and a pair of substrates on which are formed electrodes for applying a voltage to said nematic liquid crystal layer and which are disposed in an opposing manner in a form that sandwiches said nematic liquid crystal layer therebetween;

• a pair of polarizing plates disposed on either side of said liquid crystal cell in a sandwich form;
• a retardation film formed of polycarbonate (PC) and provided between said liquid crystal cell and at least one polarizing plate of said pair of polarizing plates;
• and
• voltage application means capable of selecting at least three voltages to be applied between said pair of substrates;
• wherein:
• said liquid crystal cell and said retardation film satisfy the relationships of Equations 3 and 4 below:
• .DELTA.n.multidot.d.gtoreq.1(.mu.m) Equation 3
• -0.08.ltoreq.R-.DELTA.n.multidot.d.ltoreq.0.62(.mu.m) Equation 4
• where:
• .DELTA.n.multidot.d is the product of the optical anisotropy .DELTA.n of said nematic liquid crystal layer and the thickness d of said nematic liquid crystal layer;
• and R is the sum of the products .DELTA.nj.multidot.dj of the optical anisotropy .DELTA.nj of a jth (where j is an integer) layer of said retardation film and the thickness dj of the jth layer of said retardation film, taken from a first layer to an ith layer (where i is an integer greater than or equal to j) when i layers of said retardation film are used.

A liquid crystal device comprising a liquid crystal cell having a layer of nematic liquid crystal twisted to within the range of 180.degree. to 360.degree. and a pair of substrates on which are formed electrodes for applying a voltage to said nematic liquid crystal layer and which are disposed in an opposing manner in a form that sandwiches said nematic liquid crystal layer therebetween;

• a pair of polarizing plates disposed on either side of said liquid crystal cell in a sandwich form;
• a retardation film formed of polysulfone (PSF) and provided between said liquid crystal cell and at least one polarizing plate of said pair of polarizing plates;
• and
• voltage application means capable of selecting at least three voltages to be applied between said pair of substrates;
• wherein:
• said liquid crystal cell and said retardation film satisfy the relationships of Equations 5 and 6 below:
• .DELTA.n.multidot.d.gtoreq.1 (.mu.m) Equation 6
• -0.40.ltoreq.R-.DELTA.n.multidot.d.ltoreq.0.30(.mu.m)
• where:
• .DELTA.n.multidot.d is the product of the optical anisotropy .DELTA.n of said nematic liquid crystal layer and the thickness d of said nematic liquid crystal layer;
• and R is the sum of the products .DELTA.nj.multidot.dj of the optical anisotropy .DELTA.nj of a jth (where j is an integer) layer of said retardation film and the thickness dj of the jth layer of said retardation film, taken from a first layer to an ith layer (where i is an integer greater than or equal to j) when i layers of said retardation film are used.