Method and apparatus for laser-imaging

Claim 2

The method of claim 1 wherein the first layer is characterized by efficient absorption of infrared radiation and repels ink, and further comprising the step of orienting the plate such that the first layer faces the laser source and the laser output is focused on the first layer.

Claim 3

The method of claim 1 wherein the first layer is characterized by efficient absorption of infrared radiation and repels ink, and further comprising the step of orienting the plate such that the second layer faces the laser source and the laser output is focused on the first layer through the second layer.

Claim 4

The method of claim 1 further comprising the step of orienting the plate such that the first layer faces the laser source and the laser output is focused on the first layer.

Claim 5

The method of claim 1 wherein at least the second layer is characterised by efficient absorption of infrared radiation, and wherein the substrate layer is substantially transparent to near-IR radiation and further comprising the step of orienting the plate such that the substrate layer faces the laser source and the laser output is focused on the second layer through the substrate layer.

Claim 6

The method of claim 1, claim 4 or claim 5 wherein the plate further comprises a strong, stable substrate underlying the first and second layers, and both the first and second layers are removed by exposure.

Claim 9

Printing apparatus comprising: a. means for supporting a printing plate having a printing surface and including a first layer and a second layer underlying the first layer, one of said layers being characterized by efficient absorption of infrared radiation, and the first and second layers having different affinities for at least one printing liquid selected from the group consisting of ink and an abhesive fluid for ink; b. at least one laser source capable of producing an infrared output; c. means for guiding the output of each laser to focus on the printing surface; d. means for moving the guiding means and support means relative to one another to effect a scan of the printing surface by the laser output; and e. means for selectably removing, in a pattern representing an image, at least the first layer by exposing the printing surface to the laser output during the course of the scan, thereby directly producing on the plate an array of image features.

Claim 10

The apparatus of claim 9 wherein the output of each laser reaches the printing surface by means of a single print array.

Claim 11

The apparatus of claim 10 wherein the apparatus comprises a plurality of laser sources and the outputs are arranged; a) linearly within the print array; or b) diagonally within the print array.

Claim 12

The apparatus of claim 9 wherein each guiding means is either a fiber-optic cable or a lens array positioned between the laser source and the printing surface.

Claim 13

The apparatus of claim 9 wherein the selectable-exposure means includes a pulse circuit capable of operating at speeds of at least 40,000 pulses/second.

Claim 14

The apparatus of claim 9 wherein each laser source outputs a power level of at least 0.2 megawatt/in².

Claim 15

The apparatus of claim 9 or the method of any one of claims 1 to 8 wherein each laser source emits primarily in the near-infrared region.

Claim 16

The apparatus of claim 9 or the method of any one of claims 1 to 9 wherein each laser source is a gallium arsenide laser.

Claim 17

The apparatus of claim 9 wherein the plate-support means is: a) a drum; or b) a flatbed support.

Claim 18

Apparatus for focusing the output of a laser source having an assymmetrical emission aperture, the apparatus comprising: a. a divergence-reduction lens, disposed adjacent the aperture, for creating a relatively even dispersion around the perimeter of the aperture; b. a collimating lens; and c. a focusing lens.

Claim 19

Printing apparatus comprising: a. means for supporting a printing plate having a work surface and including a first layer and a second layer underlying the first layer, one of said layers being characterized by efficient absorption of infrared radiation, and the first and second layers having different affinities for at least one printing liquid selected from the group consisting of ink and an abhesive fluid for ink; b. at least one laser source capable of producing an infrared output through an aperture; c. a fiber-optic cable associated with each laser for guiding the output of the associated laser to focus on the work surface; d. means for focusing the output of each laser source onto an end face of a fiber-optic cable, the focusing means comprising: i. a divergence-reduction lens, disposed adjacent the aperture, for creating a relatively even dispersion around the perimeter of the aperture, ii. a collimating lens, and iii. a focusing lens; e. means for moving the guiding means and support means relative to one another to effect a scan of the work surface by the laser output; and f. means for selectably removing or faciliating the removal of, in a pattern representing an image, at least the first layer by exposing the work surface to the laser output during the course of the scan, thereby directly producing on the plate an array of image features.

Claim 20

The apparatus of claim 18 or claim 19 wherein the collimating and focusing lenses are a single, double-convex lens.

Claim 21

The apparatus of claim 18 or claim 19 wherein the divergence-reduction lens provides a numerical aperture value of less than 0.3.

Claim 22

The apparatus of claim 18 or claim 19 wherein the divergence-reduction lens is any one of: a) cylindrical in shape; b) planaconvex in shape; or c) a concave-convex trough.

Claim 23

The method of claim 1 wherein the plate further comprises a reflective layer disposed between the first and second layers.

Claim 25

The method of claim 24 wherein only the first layer is removed by exposure.

Claim 26

Printing apparatus comprising: a. at least one print station including: i. a plate cylinder; ii. means for mounting, to the plate cylinder, a printing plate having a printing surface and including a first layer and a second layer underlying the first layer, one of said layers being characterized by efficient absorption of infrared radiation, and the first and second layers having different affinities for at least one printing liquid selected from the group consisting of ink and an abhesive fluid for ink; iii. at least one laser source capable of producing an infrared output; iv. means for guiding the output of each laser to focus on the printing surface; v. means for moving the guiding means and support means relative to one another to effect a scan of the printing surface by the laser output; vi. means for selectably removing, in a pattern representing an image, at least the first layer by exposing the printing surface to the laser output during the course of the scan, thereby directly producing on the plate an array of image features; and b. means for transferring a recording medium to the print station.

Claim 27

The apparatus of claim 26 wherein each print station further comprises: a. An ink train for transferring ink to the plate cylinder; and b. means for transferring ink from the plate cylinder to the recording medium.

Claim 28

The apparatus of claim 26 wherein the apparatus comprises a plurality of print stations arranged in either one of an in-line configuration or a central-impression configuration.