Printa Quality Controls provides solutions for the automatic control of registers (Printa Register System) as well as automatic control of color density.

Printa Register System (PRS) provides for the automatic control of color-to-color, unit-to-unit, turner bar and cut-off registers. It contains online measurement from virtually invisible register marks and automatic closed loop control of circumferential and lateral registers as well as web registers and turner bar compensators.

Printa Register System’s main benefits are reduction of material waste, homogeneity of print quality and makes work easier on the press.

The register control functions are based on the online measurement of very small register marks. The same marks are used in all register control applications.

Measurement is performed by cameras with an integrated data processing unit. The camera images the register marks, which are printed in a predetermined pattern next to the actual printed work. The electronic high-speed shutter of the camera allows an image to be made of the fast moving printed work. Two halogen lamps mounted at each side of the camera illuminate the web. The camera has a telecentric lens, which means that it does not need a fixed focal distance. By using this technology the system can read from an unsupported web.

The camera, including lens and lamps, is mounted on a transport bar and is manually positioned across the web width. A motorised scanner bar is also available. 

In colour-to-colour register control applications the cameras can be mounted directly after the last print couple ensuring a very tight control loop. PRS determines, from the images, the exact position of each individual register mark compared to a reference register mark.

In cut-off and side lay control applications the camera monitors the print location compared to the web location. PRS measures the position of the register marks compared to the mechanical reference of the printing press. PRS calculates the deviations from the target and corrections will be provided to the press control system.

Printa Register System is integrated with the Printa Press Drive & Control system utilizing the same user interface and controllers. Integration within the standard control desk avoids multiple monitors and makes it easier for the operator to access the system. Also integration with the standard pre-setting procedures allows the entry of job specific parameters for register control, e.g. cut-off parameters.