US Patent 7334362 Read-out device and procedure for its manufacture

Displays for information exist, which appear to emerge out of a solid piece of metal. In order to obtain an aluminium-like and translucent material, according to prior art glass has aluminium vapour deposited onto the front surface, and a diode matrix display is hidden behind this translucent material while inactive, whereas it becomes visible when lit. In order to avoid the use of glass and to make the metal surface and the display surface indistinguishable from each other under all lighting conditions, the surface is made out of the piece of material constituting the surrounding parts. A cavity is formed from behind, and the bottom of said cavity is made very thin and hence translucent by etching or a similar material removing process. Oxide layers support this translucent layer, and an internal support is provided in the cavity, said support also carrying the sources of light.