A direct-injection internal-combustion engine comprising at least one cylinder with a cylinder head, a piston sliding in the at least one cylinder, a gas intake and exhaust, a combustion chamber defined on one side by the upper face of the piston, the face comprising a projection pointing towards cylinder head and arranged at the center of a concave bowl. The quoin form includes a two frames rotatably joined by a central hinge. According to another aspect of the system, a single scrambling code generator is used to generate a master scrambling code. The lens array is arranged on the substrate at the first side thereof and includes a plurality of cylindrical stripe-like lenses, the cylindrical stripe-like lenses extending substantially parallel to each other. Exemplary coating methods include sputtering, CVD, ALD and misted deposition.