DE3127381

• Main Author: LECHA, MANUEL JULIAN, BARCELONA, ES
• Format: Patent
• Language: English
• Published: 08.03.1990
• Subjects: COLORIMETRY; LINING MACHINES; MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT,POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED,VISIBLE OR ULTRA-VIOLET LIGHT; MEASURING; PERFORMING OPERATIONS; PHYSICS; PRINTING; PRINTING MACHINES OR PRESSES; RADIATION PYROMETRY; STAMPS; TESTING; TRANSPORTING; TYPEWRITERS

An improvement in the measuring elements of closed circuit systems for controlling-correcting printing in offset printing machines is provided. The values of measurements are amplified, analogically commutated, converted from analog to digital form, and then microprocessed so as to be compared with standard values established in a memory program provided for each one of the valves controlling the printers block of each one of the printing bodies. A reading is taken decomposed into three variables, each one of which corresponds to one of the three basic colors of the visible spectrum in which the light from the colored stain is diffracted by means of a ROWLAND diffraction grating in which there is reflected the light from optical fibers arranged at 45 DEG angles with respect to the printing paper, and which direct a beam of light on the colored stain. At the point of convergence of each one of the diffracted colors, there is arranged a photo pickup device whose signal is amplified by a logarithmic amplifier and connnected to a digital signal which is sent to a microprocessor for processing.