Patent ID: 7826016

Claim:
An in-plane-switching-mode liquid crystal display (IPS LCD) device comprising: a liquid crystal (LC) layer having a first optical axis; first and second substrates sandwiching therebetween said LC layer, said first and second substrates being disposed on a light-emitting side and a light-incident side, respectively, of said LCD device; first and second polarizing films sandwiching therebetween said first and second substrates and said LC layer, said first and second polarizing films having polarization axes extending normal to each other and being disposed on the light-emitting side and the light-incident side, respectively, of said LCD device, said second polarizing film including a first protective layer, a polarization layer and a second protective layer, which are disposed consecutively as viewed from said light-incident side, each of said first and second protective layers having a retardation depending on a thickness of said each of said first and second protective layer; and an optical compensation layer disposed between said first polarizing film and said second polarizing film, wherein: said optical compensation layer has a birefringence satisfying the relationship (ns−nz)/(ns−nf)≦0.5, where ns, of and nz are a refractive index along an in-plane slow axis, a refractive index along an in-plane fast axis, and a refractive index along a thickness direction, respectively, of said optical compensation layer; an angle between said in-plane slow axis of said optical compensation layer and said first optical axis is within ±2 degrees; and said optical compensation layer has an in-plane retardation N 1 (nm), and said second optical protective layer has a thickness D 1 (μm) satisfying the following relationship: 83.050−0.810× D 1 ≦N 1 ≦228.090−0.74× D 1 , in a range of 0<D 1 ≦80.