Patent ID: 8664601

Claim:
A system for measuring and adjusting the thickness of a layer of coating deposited on a substrate, wherein the thickness is measured indirectly by measuring on a coating roller before and after the coating has been deposited on the substrate, the system comprising: a first control unit for calculating the thickness of the layer of coating deposited on the substrate; a second control unit for generating signals which indicate respective speeds of the substrate and the coating roller; a first sensor directed to an area of the coating roller between a position where coating is transferred to the coating roller and a position where coating is transferred from the coating roller to the substrate, seen in the rotational direction of the coating roller; a second sensor directed to an area of the coating roller between a position where coating is transferred from the coating roller to the substrate and a position where coating is transferred to the coating roller, seen in the rotational direction of the coating roller; wherein the first and second sensors generate respective signals relating to the thickness of a layer of coating on the coating roller at the respective areas of the coating roller to which the first and second sensors are directed; wherein the first control unit calculates the thickness of the deposited layer based on the signals generated by the first and second sensors and by the second control unit and adjusts the thickness of the deposited layer by adjusting the speed of one or more of the coating roller and the substrate.