using a transparent mirror or other light reflecting surface transparent to transmitted light whereby a sign, symbol, picture or other is visible only when illuminated

Full Title

Illuminated signs; Luminous advertising (G09F9/00, G09F11/00 take precedence; control of displays in general using static means to present variable information G09G) > Signs, boards or panels, illuminated from behind the insignia > using a transparent mirror or other light reflecting surface transparent to transmitted light whereby a sign, symbol, picture or other is visible only when illuminated