EP2741914A1 - Offset imaging system - Google Patents

Offset imaging system

Info

Publication number
EP2741914A1
EP2741914A1 EP12745596.2A EP12745596A EP2741914A1 EP 2741914 A1 EP2741914 A1 EP 2741914A1 EP 12745596 A EP12745596 A EP 12745596A EP 2741914 A1 EP2741914 A1 EP 2741914A1
Authority
EP
European Patent Office
Prior art keywords
imaging unit
offset media
image
imaging
offset
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP12745596.2A
Other languages
German (de)
French (fr)
Inventor
Moshe Nakash
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Eastman Kodak Co
Original Assignee
Eastman Kodak Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US13/205,718 external-priority patent/US20130036925A1/en
Priority claimed from US13/205,726 external-priority patent/US20130036929A1/en
Application filed by Eastman Kodak Co filed Critical Eastman Kodak Co
Publication of EP2741914A1 publication Critical patent/EP2741914A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
    • B41C1/00—Forme preparation
    • B41C1/10—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme
    • B41C1/1083—Mechanical aspects of off-press plate preparation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
    • B41C1/00—Forme preparation
    • B41C1/10—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme
    • B41C1/1008—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme by removal or destruction of lithographic material on the lithographic support, e.g. by laser or spark ablation; by the use of materials rendered soluble or insoluble by heat exposure, e.g. by heat produced from a light to heat transforming system; by on-the-press exposure or on-the-press development, e.g. by the fountain of photolithographic materials
    • B41C1/1033—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme by removal or destruction of lithographic material on the lithographic support, e.g. by laser or spark ablation; by the use of materials rendered soluble or insoluble by heat exposure, e.g. by heat produced from a light to heat transforming system; by on-the-press exposure or on-the-press development, e.g. by the fountain of photolithographic materials by laser or spark ablation

Definitions

  • This present invention relates to an imaging system for a computer- to-plate (CTP) printing system and more specifically to a processless system which includes a dedicated imaging head in conjunction with an offset printing plate.
  • CTP computer- to-plate
  • Normal plates are divided into two categories, negative plates, where the exposure is done in the image area causing the coating in the image to be stronger, and positive plates in which the exposure to the laser is done on the non-image area that is weakened by the energy.
  • negative plates normally a stronger and more robust image is achieved due to chemical cross linking, and the weak non-image area is dissolved by a developer and washed off.
  • positive plates the image is generally less robust but after exposure, the non-image is weaker and can selectively be dissolved and removed by a developer. Both positive and negative plates are gummed after the exposure of the aluminum substrate background.
  • an imaging apparatus for forming an image on an offset media includes a carriage, which moves relative to the offset media.
  • the offset media further includes a top layer and a bottom layer.
  • a first imaging head is mounted on the carriage for imaging non-image areas on the surface of the offset media by using high intensity power.
  • a second imaging mounted on the carriage for imaging image areas on the surface of the offset media by using a lower intensity than the intensity used by the first imaging unit.
  • a data feeder supplies non-image data to the first imaging unit and image data to the second imaging unit.
  • a controller provides imaging data to the data feeder. Image areas on top layer are fixated by the second imaging unit and non-image areas are ablated from the top layer by the first imaging unit.
  • FIG. 1 is a schematic representation of a plate consisting of hydrophilic and hydrophobic layers
  • FIG. 2 is a schematic representation of a plate imaging device
  • FIG. 3 is a schematic representation of printing sleeves mounted on a printing cylinder.
  • the plate imaging system 10, shown in FIG. 2 provides a processless solution for making offset printing plates or sleeves.
  • the system includes two main components.
  • the first component is an offset plate 100, shown in FIG. 1.
  • Offset plate 100 is either a negative nor a positive plate.
  • Offset plate 100 is configured for exposure by laser means over the entire offset plate 100 surface.
  • Offset plate 100 is based on a two layer construction, a bottom hydrophilic layer 108 and a top hydrophobic layer 104.
  • the hydrophilic layer allows the elimination of the gumming step.
  • the two layers 104 and 108 are positioned on a support layer 112.
  • a printing sleeves 304 FIG. 3 shows a continuous sleeve 304 mounted on a cylinder 312 and several separated sleeve sections 308 mounted on a cylinder.
  • FIG. 2 shows an imaging device 200.
  • the imaging device 200 includes an imaging carriage 220 on which a laser imaging unit 208 and laser imaging unit 212 are mounted.
  • Imaging unit 208 is set to apply radiation at an intensity higher than imaging unit 212.
  • the laser imaging units 208 and 212 are configured to image on offset plate 100, which is mounted on a rotating drum 204.
  • the carriage 220 is adapted to move substantially parallel to drum 204 guided by an advancement screw 224.
  • Offset plate 100 is exposed by laser imaging units 208 and 212.
  • Laser imaging unit 208 is configured to ablate the hydrophobic layer 104.
  • the ablated parts of hydrophobic layer 104 represent non-image areas on offset plate 100.
  • the non-imaged areas are represented by the image data 236 provided to the laser imaging unit 208 by data feeder 232.
  • the data feeder 232 receives imaging data 228 from controller 216 and sends the non-image data 236 to imaging unit 208 and the image data 240 to imaging unit 212.
  • the ablation of hydrophobic layer 104 is achieved by operating laser imaging unit 208 at high power.
  • the laser imaging unit 208 is set to operate at high power.
  • the increased power applied by imaging unit 208 on the non-image areas ablates the hydrophobic layer 104.
  • Imaging unit 212 images the image data 240, imaging unit 212 is set to operate at a lower power intensity than imaging unit 208.
  • the reduced power applied by imaging unit 212 will cause strengthening of the image by cross linking the coating and by imparting adhesion between the plate layers 104 and 108.
  • the non-imaging parts of the plate are imaged by utilizing the higher laser power imaging unit 208, whereas the imaging parts are imaged by the lower intensity imaging unit 212.
  • the non-image data 236 is provided to imaging unit 208 whereas the image data 240 is provided to imaging unit 212 by data feeder 232.
  • the imaging of plate 100 can be performed by a single path where each of laser units 208 and 212 operate together. Alternatively the imaging can be performed in two paths, wherein the first path the non-image data is treated by laser unit 208 and the image data is imaged by imaging unit 212 in a following path.
  • the sequence of imaging can be also by starting with imaging unit 212 with data 240 following with an additional path with imaging unit 208 with data 236.
  • the type and rate of the reaction on the plate is determined by the local temperature.
  • the laser head may deliver high power laser spot which ablates the hydrophobic layer on the plate.
  • the laser head provides lower energy levels, which induces a fixating reaction.
  • this system is different from known CTP systems, in that it exposes every part of the plate, partly by ablation of layer 104 to the level of layer 108 (by using higher laser power imaging unit 208) and partly by fixation of layer 104 (by using lower laser power imaging unit 212), depending on the imaging data 228.
  • non-image data for laser imaging unit 208 image data for laser imaging unit 212 printing sleeve

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • Manufacture Or Reproduction Of Printing Formes (AREA)

Abstract

An imaging apparatus (10) forms an image on an offset media (100) including a carriage (220), which moves relative to the offset media wherein the offset media includes a top and bottom layer. A first imaging unit (208) mounted on the carriage and configured to image at high intensity the non-image areas of the offset media. A second imaging unit (212) mounted on the carriage configured to image at lower intensity than the first imaging unit wherein the second imaging unit is configured to image the image of the offset media. A data feeder (232) configured to supply non-image data to the first imaging unit and image data to the second imaging unit. A controller (216) configured to provide imaging data to the data feeder. Image areas on top layer are fixated by the second imaging unit. Non-image areas are ablated from the top layer by the first imaging unit.

Description

OFFSET IMAGING SYSTEM
FIELD OF THE INVENTION
This present invention relates to an imaging system for a computer- to-plate (CTP) printing system and more specifically to a processless system which includes a dedicated imaging head in conjunction with an offset printing plate.
BACKGROUND OF THE INVENTION
Most of the known processes of making offset printing plates require the use of chemicals to dissolve the non-image area of the plate. Other processes such as pre-wash, pre -heat, gumming, and post-baking may also be used. These processes are costly and may not be environmentally friendly.
Normal plates are divided into two categories, negative plates, where the exposure is done in the image area causing the coating in the image to be stronger, and positive plates in which the exposure to the laser is done on the non-image area that is weakened by the energy.
In negative plates normally a stronger and more robust image is achieved due to chemical cross linking, and the weak non-image area is dissolved by a developer and washed off. In positive plates the image is generally less robust but after exposure, the non-image is weaker and can selectively be dissolved and removed by a developer. Both positive and negative plates are gummed after the exposure of the aluminum substrate background.
SUMMARY OF THE INVENTION
Briefly, according to one aspect of the present invention an imaging apparatus for forming an image on an offset media includes a carriage, which moves relative to the offset media. The offset media further includes a top layer and a bottom layer. A first imaging head is mounted on the carriage for imaging non-image areas on the surface of the offset media by using high intensity power. A second imaging mounted on the carriage for imaging image areas on the surface of the offset media by using a lower intensity than the intensity used by the first imaging unit.
A data feeder supplies non-image data to the first imaging unit and image data to the second imaging unit. A controller provides imaging data to the data feeder. Image areas on top layer are fixated by the second imaging unit and non-image areas are ablated from the top layer by the first imaging unit.
These and other objects, features, and advantages of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings wherein there is shown and described an illustrative embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a plate consisting of hydrophilic and hydrophobic layers;
FIG. 2 is a schematic representation of a plate imaging device; and
FIG. 3 is a schematic representation of printing sleeves mounted on a printing cylinder.
DETAILED DESCRIPTION OF THE INVENTION
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the disclosure. However, it will be understood by those skilled in the art that the teachings of the present disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the teachings of the present disclosure.
While the present invention is described in connection with one of the embodiments, it will be understood that it is not intended to limit the invention to this embodiment. On the contrary, it is intended to cover alternatives, modifications, and equivalents as covered by the appended claims.
The plate imaging system 10, shown in FIG. 2 provides a processless solution for making offset printing plates or sleeves. The system includes two main components. The first component is an offset plate 100, shown in FIG. 1. Offset plate 100 is either a negative nor a positive plate. Offset plate 100 is configured for exposure by laser means over the entire offset plate 100 surface.
Offset plate 100 is based on a two layer construction, a bottom hydrophilic layer 108 and a top hydrophobic layer 104. The hydrophilic layer allows the elimination of the gumming step. The two layers 104 and 108 are positioned on a support layer 112. Similarly a printing sleeves 304 (FIG. 3) having a bottom hydrophilic layer 108 and a top hydrophobic layer 104 can be employed according to the invention. FIG. 3 shows a continuous sleeve 304 mounted on a cylinder 312 and several separated sleeve sections 308 mounted on a cylinder.
FIG. 2 shows an imaging device 200. The imaging device 200 includes an imaging carriage 220 on which a laser imaging unit 208 and laser imaging unit 212 are mounted. Imaging unit 208 is set to apply radiation at an intensity higher than imaging unit 212. The laser imaging units 208 and 212 are configured to image on offset plate 100, which is mounted on a rotating drum 204. The carriage 220 is adapted to move substantially parallel to drum 204 guided by an advancement screw 224.
Offset plate 100 is exposed by laser imaging units 208 and 212. Laser imaging unit 208 is configured to ablate the hydrophobic layer 104. The ablated parts of hydrophobic layer 104 represent non-image areas on offset plate 100. The non-imaged areas are represented by the image data 236 provided to the laser imaging unit 208 by data feeder 232. The data feeder 232 receives imaging data 228 from controller 216 and sends the non-image data 236 to imaging unit 208 and the image data 240 to imaging unit 212. The ablation of hydrophobic layer 104 is achieved by operating laser imaging unit 208 at high power. The laser imaging unit 208 is set to operate at high power. The increased power applied by imaging unit 208 on the non-image areas ablates the hydrophobic layer 104. Imaging unit 212 images the image data 240, imaging unit 212 is set to operate at a lower power intensity than imaging unit 208. The reduced power applied by imaging unit 212 will cause strengthening of the image by cross linking the coating and by imparting adhesion between the plate layers 104 and 108.
The non-imaging parts of the plate are imaged by utilizing the higher laser power imaging unit 208, whereas the imaging parts are imaged by the lower intensity imaging unit 212. The non-image data 236 is provided to imaging unit 208 whereas the image data 240 is provided to imaging unit 212 by data feeder 232. This concept provides the benefits of both negative and positive plate technologies. A clean background will be achieved as in positive plates, in addition to the robustness of negative plates.
The imaging of plate 100 can be performed by a single path where each of laser units 208 and 212 operate together. Alternatively the imaging can be performed in two paths, wherein the first path the non-image data is treated by laser unit 208 and the image data is imaged by imaging unit 212 in a following path. The sequence of imaging can be also by starting with imaging unit 212 with data 240 following with an additional path with imaging unit 208 with data 236.
Since the processes on the plate are thermal in nature, the type and rate of the reaction on the plate is determined by the local temperature. At points where layer removal is required, the laser head may deliver high power laser spot which ablates the hydrophobic layer on the plate. At points where the plate active layer should be fixed, the laser head provides lower energy levels, which induces a fixating reaction.
In summary, this system is different from known CTP systems, in that it exposes every part of the plate, partly by ablation of layer 104 to the level of layer 108 (by using higher laser power imaging unit 208) and partly by fixation of layer 104 (by using lower laser power imaging unit 212), depending on the imaging data 228.
PARTS LIST plate imaging system
offset plate (media)
hydrophobic layer
hydrophilic layer
support layer
imaging device
drum
laser imaging unit
laser imaging unit
controller
carriage
screw
imaging data
data feeder
non-image data for laser imaging unit 208 image data for laser imaging unit 212 printing sleeve
sleeve sections
cylinder

Claims

CLAIMS:
1. An imaging apparatus for forming an image on an offset media comprising:
a carriage which moves relative to said offset media wherein said offset media further comprises a top layer and a bottom layer;
a first imaging unit mounted on said carriage and configured to image at high intensity a non-image areas of said offset media;
a second imaging unit mounted on said carriage configured to image at lower intensity than said first imaging unit wherein said second imaging unit is configured to image an image area of said offset media;
a data feeder configured to supply non-image data to said first imaging unit and image data to said second imaging unit;
a controller configured to provide imaging data to said data feeder;
wherein image areas on top layer are fixated by said second imaging unit; and
wherein non-image areas are ablated from said top layer by said first imaging unit .
2. The apparatus according to claim 1 wherein said offset media is a sleeve.
3. The apparatus according to claim 1 wherein offset media is an offset plate.
4. The apparatus according to claim 1 wherein said offset media is mounted on a cylindrical drum.
5. The apparatus according to claim 1 wherein the power intensity is adjusted by pulse width modulation.
6. The apparatus according to claim 1 wherein the power intensity is adjusted by pulse duration.
7. The apparatus according to claim 1 wherein the power intensity is adjusted by changing a wavelength of radiation produced by the imaging head.
8. The apparatus according to claim 1 wherein the offset media comprises:
a hydrophobic layer; and
a hydrophilic layer.
9. The apparatus according to claim 8 wherein the non-imaged ablated areas are the hydrophilic layer.
10. The apparatus according to claim 1 wherein said first imaging unit and said second imaging unit image said offset media at the same path.
11. The apparatus according to claim 1 wherein said first imaging unit images said offset media at a first path and said second imaging unit images said offset media at a second path.
12. The apparatus according to claim 1 wherein said second imaging unit images said offset media at a first path and said first imaging unit images said offset media at a second path.
13. A method for writing an image to a surface of an offset media comprising:
mounting said offset media on an imaging drum; imaging on a first part of said surface with a first imaging unit wherein said first imaging unit is set to operate at high energy radiation to ablate said first part wherein said first part represent non-image data; and
imaging a second part of said surface with a second imaging unit wherein said second imaging unit is set to operate at low energy radiation to fixate image data on said second part.
14. The method according to claim 13 wherein said offset media is a plate.
15. The method according to claim 13 wherein said offset media is a sleeve.
16. The method according to claim 13 wherein said first imaging unit and said second imaging unit image said offset media on the same path.
17. The method according to claim 13 wherein said first imaging unit images said offset media at a first path and said second imaging unit images said offset media at a second path.
18. The method according to claim 13 wherein said second imaging unit images said offset media at a first path and said first imaging unit images said offset media at a second path.
EP12745596.2A 2011-08-09 2012-07-18 Offset imaging system Withdrawn EP2741914A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US13/205,718 US20130036925A1 (en) 2011-08-09 2011-08-09 Offset imaging system
US13/205,726 US20130036929A1 (en) 2011-08-09 2011-08-09 Method for offset media system
PCT/US2012/047098 WO2013022571A1 (en) 2011-08-09 2012-07-18 Offset imaging system

Publications (1)

Publication Number Publication Date
EP2741914A1 true EP2741914A1 (en) 2014-06-18

Family

ID=46640105

Family Applications (1)

Application Number Title Priority Date Filing Date
EP12745596.2A Withdrawn EP2741914A1 (en) 2011-08-09 2012-07-18 Offset imaging system

Country Status (3)

Country Link
EP (1) EP2741914A1 (en)
CN (1) CN103732408A (en)
WO (1) WO2013022571A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3894223B1 (en) * 2018-12-13 2022-12-28 Eastman Kodak Company Low-volume flexographic and gravure inking systems

Family Cites Families (10)

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Publication number Priority date Publication date Assignee Title
GB1489308A (en) * 1974-03-18 1977-10-19 Scott Paper Co Laser imagable dry planographic printing plate blank
US5654125A (en) * 1995-05-01 1997-08-05 E. I. Du Pont De Nemours And Company Laser apparatus and process of use
US6367381B1 (en) * 2000-02-22 2002-04-09 Polyfibron Technologies, Inc. Laser imaged printing plates comprising a multi-layer slip film
DE10028790A1 (en) * 2000-06-15 2001-12-20 Heidelberg Instruments Mikrotechnik Gmbh Laser lithographic manufacture of circuit board by direct marking by exposing photoresist at different wavelength than that used to expose latent mask
US6832552B2 (en) * 2001-06-26 2004-12-21 Creo Inc. Method of automated setting of imaging and processing parameters
US7827912B2 (en) * 2006-12-22 2010-11-09 Eastman Kodak Company Hybrid optical head for direct engraving of flexographic printing plates
US8389203B2 (en) * 2007-05-08 2013-03-05 Esko-Graphics Imaging Gmbh Exposing printing plates using light emitting diodes
US8153347B2 (en) * 2008-12-04 2012-04-10 Eastman Kodak Company Flexographic element and method of imaging
EP2275870A1 (en) * 2009-07-14 2011-01-19 Flint Group Germany GmbH Method of manufacturing cylinder-shaped flexographic plates using digital images
US20110014573A1 (en) * 2009-07-14 2011-01-20 Eynat Matzner System for engraving flexographic plates

Non-Patent Citations (1)

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Title
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Also Published As

Publication number Publication date
CN103732408A (en) 2014-04-16
WO2013022571A1 (en) 2013-02-14

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