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US 10,766,247 B2Granted
Exposing printing plates using light emitting diodes
AssigneeEsko-Graphics Imaging GmbH
InventorWolfgang Sievers
Life of this patent
Estimating the term…
Abstract
An apparatus comprises: (a) a rotatable drum configured to have a UV-curable printing plate with an ablatable layer thereon, placed thereon; (b) at least one laser beam to image the plate on the drum by ablating some of the ablatable layer according to image data to form an imaged plate; (c) an unloading area onto which a plate is movable when unloaded; and (d) a plurality of UV LEDs configured to apply UV radiation to the back of the UV-curable plate or to both the front and back of the UV-curable plate during or after the unloading of the imaged plate.
Claims22
An apparatus comprising:
- a rotatable imaging drum configured to have a UV-curable printing plate placed thereon, the plate having a front and a back, the drum operative to rotate during an imaging process, the plate having an ablatable layer on the front thereof, the plate being a UV-curable flexographic plate, a UV-curable letterpress plate, or a UV-curable sleeve;
- a source of one or more laser beams coupled to a source of image data and operable during the imaging process to image the UV-curable plate that has been placed on the drum, the imaging using the source of one or more laser beams causing ablating of some of the ablatable layer according to imaging data to form an imaged plate;
- an unloading area onto which the imaged plate is movable as part of an unloading process that unloads the imaged plate from the drum;
- a plurality of UV emitting LEDs (UV LEDs) configured to apply UV radiation to the back of the plate or to both the front and the back of the plate during or after the placing of the plate on the drum or during or after the unloading of the imaged plate;
- wherein the UV radiation has divergence that is adjustable by tilting some of the UV LEDs differently with respect to each other such that UV radiation beams emitted by the UV LEDs towards the imaged plate emanate in a plurality of directions, and
- wherein the plurality of UV LEDs collectively emit a plurality of wavelengths and are supplied by respective controllable power sources to produce the UV radiation having a spectral composition.
3 more elements
An apparatus comprising:
- a rotatable imaging drum configured to have a UV-curable printing plate placed thereon, the drum operative to rotate during an imaging process, the plate having a front and a back and an ablatable layer on the front thereof, the plate being a UV-curable flexographic plate, a UV-curable letterpress plate, or a UV-curable sleeve;
- a source of one or more laser beams coupled to a source of image data and operable to image the UV-curable plate on the drum by ablating some of the ablatable layer according to imaging data to form an imaged plate;
- an unloading area onto which a plate is movable when unloaded from the drum;
- and
- a plurality of UV emitting LEDs (UV LEDs) configured to apply UV radiation to the back of the UV-curable plate or to both the front and back of the UV-curable plate during or after the removing of the imaged plate,
- wherein the plurality of UV LEDs collectively emit a plurality of wavelengths and are supplied by respective controllable power sources to produce UV radiation having a spectral composition, and wherein respective spectral compositions of the UV radiation produced by respective subsets of the UV LEDs are individually controllable by controlling the respective power sources for the respective subsets, and
- wherein the UV radiation has divergence that is adjustable by tilting some of the UV LEDs differently with respect to each other such that UV radiation beams emitted by the UV LEDs towards that imaged plate emanate in a plurality of directions.
4 more elements
A method comprising:
- placing a printing plate with photo-curable material thereon on an external drum imager that includes a drum that rotates during imaging, wherein the plate has a front and a back and initially has ablatable masking material on the photo-curable material on the front;
- imaging the plate according to imaging data to form least an imaged portion of the plate, wherein the imaging includes ablating some of the ablatable masking material on the photo-curable material according to the imaging data to form a mask ablated according to the imaging data on the plate;
- removing the imaged plate;
- and
- applying UV radiation to the back of the printing plate or to both the front and the back of the printing plate using a plurality of UV emitting LEDs (UV LEDs) during or after the placing of the plate or during or after the removing of the imaged plate,
- wherein the printing plate is a photopolymer flexographic plate initially having the ablatable masking material thereon, a photopolymer letterpress plate initially having the ablatable masking material thereon, or a photopolymer sleeve initially having the ablatable masking material thereon;
- wherein the plurality of UV LEDs collectively emit a plurality of wavelengths and are supplied by respective controllable power sources to produce UV radiation having a spectral composition, and wherein respective spectral compositions of the UV radiation produced by respective subsets of the UV LEDs are individually controllable by controlling the respective power sources for the respective subsets, and
- wherein the UV radiation has divergence that is adjustable by tilting some of the UV LEDs differently with respect to each such that UV radiation beams emitted by the UV LEDs towards that imaged plate emanate in a plurality of directions.
5 more elements
A method comprising:
- placing a printing plate with photo-curable material thereon on an imaging device, wherein the plate has a front and a back and initially has ablatable masking material on the photo-curable material;
- imaging the front of the plate according to imaging data to form an imaged plate, wherein the imaging includes ablating some of the ablatable masking material on the photo-curable material according to the imaging data to form a mask ablated according to the imaging data on the plate, such that the imaged plate includes the mask ablated according to the imaging data;
- removing the imaged plate;
- and
- applying UV radiation to the back of the printing plate using a plurality of UV emitting LEDs (UV LEDs);
- wherein the printing plate is a photopolymer flexographic plate initially having the ablatable masking material thereon, a photopolymer letterpress plate initially having the ablatable masking material thereon, or a photopolymer sleeve initially having the ablatable masking material thereon,
- wherein the plurality of UV LEDs comprise a plurality of wavelengths supplied by respective controllable power sources to produce UV having a spectral composition, and wherein the respective spectral compositions of the UV produced by respective subsets of the UV LEDs are individually controllable by controlling the respective power sources for the respective subsets, and
- wherein the UV radiation has divergence that is adjustable by tilting some of the UV LEDs differently with respect to others such that UV radiation beams emitted by the UV LEDs emanate towards that imaged plate in a plurality of directions.
5 more elements
A method comprising:
- placing a printing plate with photo-curable material thereon on an external drum imager that includes a drum that rotates during imaging, wherein the plate initially has ablatable masking material on the photo-curable material;
- imaging the plate according to imaging data to form least an imaged portion of the plate, wherein the imaging includes ablating some of the ablatable masking material on the photo-curable material according to the imaging data to form a mask ablated according to the imaging data on the plate;
- applying UV radiation to the at least imaged portion of the plate by exposing the plate having the ablated masking material thereon to the UV radiation using a plurality of UV emitting LEDs (UV LEDs) to cure photo-curable material on the at least imaged portion of the plate during the process of imaging of the printing plate,
- wherein the printing plate is a photopolymer flexographic plate initially having the ablatable masking material thereon, a photopolymer letterpress plate initially having the ablatable masking material thereon, or a photopolymer sleeve initially having the ablatable masking material thereon,
- wherein the UV LEDs emit a plurality of wavelengths and are supplied by respective controllable power sources to produce UV having a spectral composition, and wherein the respective spectral compositions of the UV produced by respective subsets of the UV LEDs are individually controllable by controlling the respective power sources for the respective subsets, and
- wherein the UV radiation has divergence that is adjustable by tilting some of the UV LEDs differently with respect to each such that UV radiation beams emitted by the UV LEDs towards that imaged plate emanate in a plurality of directions, such that imaging of one part of the plate and curing of an imaged portion of the plate occur simultaneously.
3 more elements
Dependencies are inferred from the claim text.