A display device (1) has an extendible screen (2) and at least one extendible side member (3). The extendible screen (2) is extendible in an extension direction from a relatively compact form to an extended form. The screen (2) in the extended form has opposed edges (17) that are substantially parallel to the extension direction. An extendible side member (3) is provided for at least one of said opposed edges (17). The or each extendible side member (3) is extendible to provide support to and structural rigidity to the screen (2) when the screen (2) is in the extended form. The display device (1) provides an extendible rigid screen (2) suitable for example for creating a rigid collapsible tablet computer, or enabling a compact portable display to support a rigid touch-screen, or for incorporation into a mobile phone or remote control unit.