Display device for displaying two overlapping graphics independently, in particular on a push button type switch

A display device for displaying two images independently comprises a first image 58 which is edge illuminated and is formed by etching on the rear surface 56 of a first layer 50, and a second image 80 which is backlit and formed as a mask layer having opaque regions. A second layer 70 is provided, the front surface 74 of which is etched to form a negative 76 of the first image. A first light source, e.g. LED 62, is provided for illuminating the first image via light pipe 54 and edge illumination of first layer 50. A second light source, e.g. LED 84, is provided for rear illumination of the second image. When the first light source is illuminated, light striking the etched first image region is directed out of the front surface, thereby making the first image visible to a viewer. When the second light source is illuminated, emitted light passes through the mask layer and the first and second layers thereby displaying the second graphic to a viewer of the display whilst concealing the first graphic. The display is preferably part of a push-button switch. The images may be overlapping with each viewable separately and independently depending on which light source is illuminated. As the whole of the display is etched, either by formation of the first image or the negative of the first image, when the images are backlit the first image is hidden and not discernible.