Printing plate registration using a camera

An apparatus for imparting a print image on a printing plate, the apparatus comprising:

• a) a substantially cylindrical imaging drum comprising at least one clamp for securing the printing plate on a cylindrical surface of the imaging drum in an orientation wherein:
• i) a reference edge of the printing plate extends along the imaging drum in a substantially axial direction;
• and
• ii) the reference edge protrudes over a slot in the cylindrical surface, the slot extending along the cylindrical surface in an axial direction;
• b) an illumination source operable for illuminating a region associated with at least one point on the reference edge, the region comprising at least a part of the reference edge;
• c) a digital camera operable for capturing a digital camera image of the region;
• d) one or more processors operable for:
• i) determining a location of the at least one point by at least locating the at least a part of the reference edge in the digital camera image;
• ii) adjusting print image data representing the print image in accordance with the determined locations of the at least one point, the adjusted print image data comprising data to align the print image with at least the determined location of the at least one point;
• and
• iii) an imaging head operable for receiving the adjusted print image data from the one or more processors and for imparting the print image onto the printing plate in accordance with the adjusted print image data;
• wherein:
• the at least one clamp comprises an illumination baffle and an imaging aperture;
• the illumination source is operable for illuminating the reference edge through the illumination baffle in the at least one clamp;
• and
• c) the digital camera is operable for imaging the reference edge through the imaging aperture in the at least one clamp.

An apparatus for determining the orientation of a printing plate, the apparatus comprising:

• a) a substantially cylindrical imaging drum comprising at least one clamp for securing the printing plate on a cylindrical surface of the imaging drum in an orientation wherein:
• i) a reference edge of the printing plate extends along the imaging drum in a substantially axial direction;
• and
• ii) the reference edge protrudes over a slot in the cylindrical surface, the slot extending along the cylindrical surface in an axial direction;
• b) an illumination source operable for illuminating a region associated with at least one point on the reference edge, the region comprising at least a part of the reference edge;
• c) a digital camera operable for capturing a digital camera image of the region;
• d) one or more processors operable for determining a location of the at least one point by at least locating the at least a part of the reference edge in each digital camera image;
• wherein:
• the illumination source is operable for illuminating the reference edge through the at least one clamp;
• and
• the digital camera is operable for imaging the reference edge through the at least one clamp.

An apparatus for determining the orientation of a printing plate, the apparatus comprising:

• a) a substantially cylindrical imaging drum comprising at least one clamp for securing the printing plate on a cylindrical surface of the imaging drum in an orientation wherein:
• i) a reference edge of the printing plate extends along the imaging drum in a substantially axial direction;
• and
• ii) the reference edge protrudes over a slot in the cylindrical surface, the slot extending along the cylindrical surface in an axial direction;
• b) an illumination source operable for illuminating a region associated with at least one point on the reference edge, the region comprising at least a part of the reference edge;
• c) a digital camera operable for capturing a digital camera image of the region;
• d) one or more processors operable for determining a location of the at least one point by at least locating the at least a part of the reference edge in each digital camera image;
• wherein:
• the at least one clamp comprises an illumination baffle and an imaging aperture;
• the illumination source is operable for illuminating the reference edge through the illumination baffle in the at least one clamp;
• and
• the digital camera is operable for imaging the reference edge through the imaging aperture in the at least one clamp.

An apparatus for determining the location of a reference edge of a plate relative to a substrate on which the plate is mounted, the apparatus comprising:

• a) a slot in the substrate, the slot:
• i) extending along the substrate in a first direction;
• ii) having a recessed surface;
• and
• iii) configured to allow placement of the plate with the reference edge extending along the substrate in substantially the first direction with the reference edge protruding over the slot;
• b) an illumination source operable for illuminating a region associated with a point on the reference edge, the region comprising at least a part of the edge;
• c) a digital camera operable for capturing a digital camera image of the region;
• d) one or more processors operable for determining a location of the point by at least locating the at least a part of the reference edge in the digital camera image;
• wherein:
• the apparatus further comprises at least one clamp for clamping the plate to the substrate at the point;
• the illumination source is operable for illuminating the reference edge through the at least one clamp;
• and
• the digital camera is operable for imaging the reference edge through the at least one clamp.