SYSTEM AND METHOD EMPLOYING SECONDARY BACK EXPOSURE OF FLEXOGRAPHIC PLATE

• US 20100028815A1
• Filed: 07/31/2008
• Published: 02/04/2010
• Est. Priority Date: 07/31/2008
• Status: Active Grant

• Current Assignee: Miraclon Corporation
• Original Assignee: Eastman Kodak Company
• Inventors: Zwadlo, Gregory L.
• Granted Patent: US 8,034,540 B2
• Time in Patent Office: Days
• US Class Current: 430/325
• CPC Class Codes: G03F 7/2014 Contact or film exposure of light sensitive plates such as lithographic plates or circuit boards, e.g. in a vacuum frame
• CPC Class Codes: G03F 7/2016 Contact mask being integral part of the photosensitive element and subject to destructive removal during post-exposure processing
• CPC Class Codes: G03F 7/202 Masking pattern being obtained by thermal means, e.g. laser ablation
• CPC Class Codes: G03F 7/2022 Multi-step exposure, e.g. hybrid; backside exposure; blanket exposure, e.g. for image reversal; edge exposure, e.g. for edge bead removal; corrective exposure
• CPC Class Codes: G03F 7/203 comprising an imagewise exposure to electromagnetic radiation or corpuscular radiation
• CPC Class Codes: G03F 7/2057 using an addressed light valve, e.g. a liquid crystal device

Abstract

A method of making a relief image on a flexographic print plate including imagewise exposing a mask including an imageable material disposed on a mask substrate to form an imaged mask having a mask image in the imageable material disposed on the mask substrate, the mask image including mask image areas each having a highlight value. The method further includes laminating the imaged mask to a front surface of a flexographic printing plate precursor, and exposing selected areas of the flexographic printing plate precursor to an imagewise addressable curing radiation via a back surface of the flexographic printing plate precursor based on the highlight values of corresponding mask image areas of the mask image.

Claims

11. A system for forming a relief image on a flexographic print plate comprising:

a laminator configured to laminate configured to laminate an imaged mask having a mask image to a front surface of a flexographic printing plate precursor, the mask image having mask image areas each having a highlight value;

a main exposure unit configured to expose the flexographic printing plate precursor to curing radiation through the imaged mask; and

a secondary exposure unit configured to expose selected areas of the flexographic printing plate precursor to curing radiation via a back surface of the flexographic printing plate precursor based on highlight values of corresponding mask image areas of the mask image.

12. The system of claim 11, wherein the selected areas comprise mask image areas having a highlight value at or below a highlight value threshold.

13. The system of claim 11, wherein the flexographic printing plate precursor includes a substantially uniformly exposed layer proximate to the back surface formed by exposing the entire back surface to a curing radiation.

14. The system of claim 11, wherein the secondary exposure unit is indexed to the mask image based on stored digital data representative of the mask image.

15. The system of claim 11, wherein the secondary exposure unit comprises a plurality of individually controllable radiation sources.

16. The system of claim 15, wherein the individually controllable radiation sources comprises an array of ultraviolet light emitting diodes.

17. The system of claim 15 wherein the individually controllable radiation sources comprises a plurality of optical fibers coupled to individually addressable light sources.

18. The system of claim 15, wherein the individually controllable radiation sources comprise individually controllable micro mirrors of a digital light projector (DLP).

19. A method of forming a relief image on a flexographic print plate comprising

laminating an imaged mask having a mask image to a front surface of a flexographic printing plate precursor, the mask image having mask image areas each having a highlight value;

and

exposing selected areas of the flexographic printing plate precursor to an imagewise addressable curing radiation via a back surface of the flexographic printing plate precursor based on highlight values of corresponding mask image area of the mask image.

1. A method of making a relief image on a flexographic print plate, the method comprising:

imagewise exposing a mask including an imageable material disposed on a mask substrate to form an imaged mask having a mask image in the imageable material disposed on the mask substrate, the mask image including mask image areas each having a highlight value;

laminating the imaged mask to a front surface of a flexographic printing plate precursor; and

exposing selected areas of the flexographic printing plate precursor to an imagewise addressable curing radiation via a back surface of the flexographic printing plate precursor based on the highlight values of corresponding mask image areas of the mask image.

2. The imaging system of claim 1, wherein the selected areas comprise mask image areas having a highlight value at or below a highlight value threshold.

3. The method of claim 1, including exposing the entire back surface of the flexographic printing plate precursor to a curing radiation to form a substantially uniformly exposed layer of the flexographic printing plate precursor proximate to the back surface prior to exposing selected areas of the flexographic printing plate precursor via the back surface.

4. The method of claim 1, including:

exposing the flexographic printing plate precursor to curing radiation through the imaged mask;

removing the imaged mask from the flexographic printing plate precursor; and

developing the flexographic printing plate precursor to remove portions of the flexographic printing plate precursor unexposed to curing radiation to form the flexographic printing plate, the remaining exposed portions forming the relief image.

5. The method of claim 4, wherein exposing the selected areas of the flexographic printing plate precursor and exposing the flexographic printing plate precursor through the imaged mask is performed without vacuum drawdown.

6. The method of claim 1, wherein exposing selected areas includes providing the imagewise addressable curing radiation via a plurality of individually addressable radiation sources.

7. The method of claim 6, wherein the radiation sources comprise ultraviolet light sources.

8. The method of claim 6, wherein the individually addressable radiation sources comprises an array of ultraviolet light emitting diodes.

9. The method of claim 6, wherein the individually addressable radiation sources comprises a plurality of individually addressable optical fibers coupled to light sources.

10. The method of claim 6, wherein the individually addressable radiation sources comprise individually addressable micro mirrors of a digital light projector (DLP).

20. The method of claim 19, wherein the selected areas comprise mask image areas having a highlight value at or below a highlight value threshold.

21. The method of claim 19, including:

exposing the flexographic printing plate precursor to curing radiation in a flood-wise fashion through the imaged mask;

removing the imaged mask from the flexographic printing plate precursor; and

developing the flexographic printing plate precursor to remove portions of the flexographic printing plate precursor unexposed to curing radiation to form the flexographic printing plate, the remaining exposed portions forming the relief image.

21-1. The method of claim 19, wherein the imagewise addressable curing radiation comprises ultraviolet radiation provided by an array of individually addressable ultraviolet light emitting diodes.