US Patent 11770946 Window and display device having the same

A window for a display device includes: a film having flexibility; and at least one coating layer disposed on the film. As tensile stress acting on the film increases, the film is elastically deformed in a first range of strains of the film and plastically deformed in a second range of strains of the film greater than the first range, the first and second ranges being defined by a relationship between the tensile stress and a strain of the film in accordance with the tensile stress. The film has a yield strain in a third range from about 1.9% to about 2.25%, and the yield strain is defined as the strain of the film when a yield stress of the relationship in the first range is applied to the film.