Decoration method and machine for the surface decoration of a ceramic article

A method for the surface decoration of a ceramic article the method comprises:

• a conveying step, during which a ceramic article is conveyed by a conveyor device along a given path in a moving direction through a printing station;
• a printing step, which is at least partially simultaneous with said conveying step and during which a printing assembly, which is arranged at said printing station and is provided with a plurality of digital printing devices arranged in succession along said moving direction applies a defined pattern on a surface to be decorated of the ceramic article;
• a detection step, which is at least partially simultaneous with said conveying step and during which a detection unit detects a quantity correlated with the moving speed of said conveyor device;
• and
• a control step, which is at least partially subsequent to said detection step and during which a control unit adjusts the mutual operation of the different digital printing devices of said printing assembly as a function of said quantity correlated with the moving speed of said conveyor device detected during said detection step, so as to apply said defined pattern on the surface to be decorated of the ceramic article;
• said conveyor device comprising a metal support structure and a belt, which is fitted on said metal support structure and defines a transport plane to support the ceramic article;
• said detection unit comprising a reference integral to said belt;
• and
• said detection step comprising, in turn, a reading sub-step, during which at least one detector detects each passage of said reference at a first given position and emits a detection signal, and a processing sub-step, during which a processing device receives the detection signals emitted by said at least one detector and estimates said quantity correlated with the moving speed of said conveyor device as a function of the distance between the emission of two following detection signals.