Functional unit with button functions

A method of producing a multifunctional functional unit with a rigid support structure, in which control elements and/or display elements are arranged behind a transparent surface layer which is continuous over substantially the entire functional unit, the method comprising:

• i) punching at least one positioning hole in a flat, flexible and at least in places transparent plastics film with a thickness in the range from 0.05-0.4 mm;
• ii) introducing the flat plastics film in a precisely positioned manner, using the at least one positioning hole, into an injection mould provided with a corresponding positioning means, for engaging in the positioning hole, and back-injecting the plastics film to form a substantially continuous hard plastics support on the first side, the injection mould being designed such that, in the region of the control elements and/or display elements, the plastics film is not back-injected at least in places and remains bare in the form of at least two recesses;
• iii) on the second side remote from the first side, flooding the plastics film in the same injection mould or, after transfer of the blank into a further injection mould, in this further injection mould, substantially all over with a transparent curing casting compound in a reaction injection moulding (RIM) method and coating over substantially the entire functional unit to form a continuous transparent surface layer with a thickness of at least 0.1 mm membrane regions which are flexible at least in places being formed in the region of the recesses;
• and
• iv) inserting control elements and/or display elements into the recesses and joined to the plastics support.