Patent attributes
Provided is a display device containing a crystalline piezoelectric polymer layer having a helical chiral polymer (A) that has a weight average molecular weight of from 50,000 to 1,000,000 and has optical activity, an optical compensation layer satisfying the following expression (1), and a linear polarizer. In expression (1), Xc represents a degree of crystallinity (%) of the crystalline piezoelectric polymer layer obtained by a DSC method; MORc represents a standardized molecular orientation of the crystalline piezoelectric polymer layer measured by a microwave transmission molecular orientation meter when a reference thickness is 50 μm; d represents a thickness (μm) of the crystalline piezoelectric polymer layer; and Rth represents a phase difference (nm) in a thickness direction of the optical compensation layer at a wavelength of 550 nm.|0.06×Xc×MORc×d+Rth|≤500 Expression (1):
