| abstract |
The present invention provides a display device which is equipped with a crystalline-polymer piezoelectric layer comprising a helical chiral polymer (A) that has a weight-average molecular weight of 50,000-1,000,000 and has optical activity, an optical compensation layer that satisfies relationship (1), and a linear polarizer [in relationship (1), Xc represents the crystallinity (%), obtained by DSC, of the crystalline-polymer piezoelectric layer; MORc represents the normalized molecular orientation of the crystalline-polymer piezoelectric layer when the reference thickness measured with a microwave transmission molecular orientation meter is 50 μm; d represents the thickness (μm) of the crystalline-polymer piezoelectric layer; and Rth represents the thickness-direction retardation (nm), measured at wavelength of 550 nm, of the optical compensation layer].nRelationship (1): |0.06×Xc×MORc×d+Rth|≤500 |