Fountain solution film thickness measurement system using Fresnel lens optical properties

An image forming device controlling fountain solution thickness on an imaging member surface of a rotating imaging member, comprising:

• a fountain solution applicator configured to apply a fountain solution fluid layer at a dispense rate onto the imaging member surface in an image making direction for rendering a printing,
• a transparent roller having a surface of a predetermined roughness and where said transparent roller further comprises an imaging device positioned within said transparent roller for capturing light passing through said surface, said surface forming a lens and wherein light passing through said lens to said imaging device is defined by a first set of optical properties;
• a heat source for evaporating said dispensed fountain solution from said imaging member to said transparent roller where said evaporated fountain solution then condenses onto said transparent roller, said condensed fountain solution wetting said surface to alter said first set of optical properties to a second set of optical properties;
• a controller in communication with said imaging device to compare said first set of optical properties with said second set of optical properties to determine a thickness of said dispensed fountain solution on said transparent roller and in accordance therewith to define a modified fountain solution dispense rate to provide an optimum thickness of said dispensed fountain solution thickness;
• said fountain solution applicator configured to apply a subsequent fountain solution layer at the modified fountain solution dispense rate onto the imaging member surface for rendering a subsequent printing.