Method and device for measuring the thickness of a fountain solution layer or ink emulsion layer in offset printing
AssigneeGvt GmbH
InventorKlaus-P. Dotzel
Life of this patent
Estimating the term…
Abstract
A method and a device for measuring the thickness of a fountain solution layer or ink emulsion layer on the surface of a cylinder bearing the print image of an offset printing machine is proposed, in which the absorption of reflected near infrared radiation is measured by the dampening water that is applied during print production. Interferences due to optical reflection are eliminated by means of a gloss trap. A position-controlled regulation of the dampening water allocation is reliably maintained by means of machine synchronization of the measuring unit and receiving unit.
Claims16
Method for measuring the thickness of a fountain solution layer or ink emulsion layer on a cylinder bearing a print image of an offset printing machine,
- in which two monochrome infrared beams with different wave lengths are directed simultaneously or sequentially onto at least one defined measurement position and are reflected there,
- whereby the reflected radiation is captured in an analysis unit,
- wherein the infrared beams are near infrared beams and that the one reflected near infrared beam is substantially absorbed by the fountain solution or the ink emulsion as measurement beam, and
- the other near infrared beam as comparison beam is not substantially absorbed by the fountain solution or by the ink emulsion.
Method according to 3,
- wherein the at least one gloss trap is formed by a polarizer.
Device for measuring the thickness of a fountain solution layer or an ink emulsion layer on a cylinder bearing a print image of an offset printing machine, the device comprising:
- an optical measurement system comprising a near infrared radiation source for generating emitted near infrared radiation and a near infrared radiation receiver for receiving reflected near infrared radiation,
- whereby the optical paths of the emitted near infrared radiation and the reflected near infrared radiation are parallel to each other, and
- an analysis unit operatively coupled to the optical measurement system for analyzing the data transmitted by the near infrared radiation receiver.
Dependencies are inferred from the claim text.