A printing mechanism (10) has a plate cylinder (12) that supports a printing plate (18). A printing plate reference field (100) has a lowest reference field surface (101) lower than the printing plate (18) and a highest reference field surface (105) higher the printing plate in the printing motif region. A control unit can vary a distance between an impression cylinder (28) and the plate cylinder (12) for pressing a printing substrate against the printing plate (18) and can very a distance between an inking roller (20) and the printing plate (18). A first sensor (34) connected to the control unit determines a quality of a printed image of the printing plate reference field (100) on the printing substrate (30) and a second sensor (36) connected to the control unit determines a quality of a negative image of the printing plate reference field (100) on the inking roller (20).

Disclosed herein is a method of managing a printing apparatus including a thermal print head. The method of managing a printing apparatus includes: starting, by the controller of a printing apparatus, the cleaning of a thermal print head when a predetermined condition is satisfied; selecting, by the controller, a cleaning method based on at least one the satisfied condition and previously stored information; and cleaning, by the controller, the thermal print head by driving at least one of heating elements, included in a plurality of recording elements constituting the thermal print head, according to the selected cleaning method.

A reimageable layer of an imaging member is provided with a dampening fluid layer. The reimageable layer has specific properties such as composition, surface profile, and so on so as to be well suited for receipt and carrying the dampening fluid layer. An optical patterning subsystem such as a scanned modulated laser patterns the dampening fluid layer. Ink having a first set of properties such as color, composition, etc., is applied at an inking subsystem such that it selectively resides in voids formed by the patterning subsystem in the dampening fluid layer to thereby form an inked latent image. The inked latent image is then transferred to a substrate, and the reimageable surface cleaned. The process is repeated for a second ink having properties different than the first. Each ink image may successively be applied to the substrate, or a composite image may be formed then applied to the substrate.

An adjuster for first and second print rollers carried on respective first and second supports has a first spindle extending along and rotatable about an axis between the supports and formed with a pair of axially spaced screwthreads of the same hand but of different pitches. One of the screwthreads is threaded into the first support and the other into a first nut rotatable about the axis and axially fixed in the second support. A mechanism serves for either arresting the nut against rotation relative to the second support and or rotating the nut relative to the second support.

An adjuster for first and second print rollers carried on respective first and second supports has a first spindle extending along and rotatable about an axis between the supports and formed with a pair of axially spaced screwthreads of the same hand but of different pitches. One of the screwthreads is threaded into the first support and the other into a first nut rotatable about the axis and axially fixed in the second support. A mechanism serves for either arresting the nut against rotation relative to the second support and or rotating the nut relative to the second support.

An apparatus for replacing printing sleeves which comprises a handling device which can be removably engaged with a printing sleeve and a movement robot for moving the handling device; the handling device comprises a supporting frame and a self-centering grip clamp which is able to translate on command, with respect to the supporting frame, along a movement direction that is substantially parallel to the axis of the supporting rod, between an advanced working position and a retracted working position; the grip clamp has engagement elements which are movable on command between an inactive position and an active position, in which they are radially spaced apart from the axis of the supporting rod, in order to allow their engagement with the internal surface of the printing sleeve.