Sheet Fed Inspection

VCortex has developed its own Compact Imaging Sensor with high-resolution imaging, and a real time processing system ideal for the fastest printers in the offset printing market (18,000 sheets/hour).

A slim, compact sensor, with its illumination, optics and electronics is installed under the walkway, near the impression cylinder. No need for any HW calibrations.

Every sheet is monitored in full width. When a change in density, or in other parameters, is detected - a special algorithm analyses it and automatically sends a correction signal to the control console of the press.

Sheet Fed control

The system design is based on a thorough understanding of color vision and color printing. The multi-discipline system design includes: optics, electronics, mathematical algorithms, and real time data processing. This has been achieved by taking into full consideration color science, printing market needs and structure, and the operation of printing presses.

Major features:

Fast Color Setup & Control: The system scans, on the press, every sheet and covers the whole sheet area.

Real time accurate Color density measurement information and its derivatives are automatically fed back into the press control system, in order to be used in the adjustment of the ink keys, ink roller, and solution roller so that the highest color stability may be maintained.

Set-up time is significantly reduced - less than 5 minutes per job - due to elimination of manual observation and correction. Press utilization is increased, especially for short runs.

Color Registration: A real time every sheet monitoring provides registration better than 10 microns accuracy data.

Sheet View: A real time, sharp and clear image of the printed sheet is presented on a 17" monitor. The image can be zoomed-in in order to view the finest printing details.

Sheet Inspection (Optional): each sheet is inspected against a 'golden master' that is captured at the end of the setup phase, to make sure that no defective sheet will escape to the customer unnoticed.

Color Measurements (Optional): Color values in LAB or XYZ are measured and displayed for delineated pre-defined areas. The measurements are checked against master values that are previously set externally, captured by the system at the end of the setup time, or saved by the operator from a similar former job. The difference is compared against a threshold in CMC2 :1, CMC1 :1 or plain ΔE.