US Patent 11917778 Foldable display device

A foldable display device includes a first casing and a second casing. The first casing is rotatable about a first rotation center, and the second casing is rotatable about a second rotation center. Coordinates of an orthographic projection of the first rotation center on an xoy coordinate plane are (x1, y1), and coordinates of an orthographic projection of the second rotation center on the xoy coordinate plane are (−x1, y1). A predetermined value is defined by a sum of coordinate values x1 and y1, the coordinate value x1 is greater than zero, and the coordinate value y1 is greater than −0.3 millimeter (mm) and less than or equal to one mm.