Apparatus and method for printing on irregular surfaces

Abstract

An apparatus and method for presenting a substrate/print media having favorable surface conditions and optimum spatial orientation for printing purposes. The apparatus/method includes a mechanism for maintaining the substrate/print media in a substantially orthogonal spatial orientation relative to the direction of ink deposition, and a pressurization device for developing a pressure differential across a face surface of the substrate/print media such that positive pressure is applied to a surface opposing the face surface. The pressurization device provides a cushion of air to support the substrate/print media during ink deposition. The apparatus/method may further include a system for transporting the substrate/print media beneath or across a print head assembly for in-line printing on a mailpiece.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention. As shown throughout the drawings, like reference numerals designate like or corresponding parts.

FIG. 1 depicts a side view of an in-line printing apparatus, the apparatus producing an optimum print surface for printing clear, legible text and graphics on the face surface of a substrate material.

FIG. 2 depicts a cross-sectional view taken substantially along line 2-2 of FIG. 1 illustrating a plenum circumscribing the print head, which plenum develops a pressure differential across the face surface of the substrate material.

FIG. 3 depicts an enlarged partial cross-sectional view taken substantially along line 3-3 of FIG. 2 illustrating features of the apparatus which lift the face surface of the substrate material away from underlying structures/elements to present a substantially planar surface for printing.

FIG. 4 depicts an alternate embodiment of the invention including upper and lower conveyors for supporting/moving the mailpiece past an in-line print head and a linear plenum system for developing a pressure differential along the face surface of the substrate material.

FIG. 5 depicts a cross-sectional view taken substantially along line 5-5 of FIG. 4 illustrating a pair of linear plenums disposed to either side of the in-line print head.

FIG. 6 depicts an enlarged view of one of the linear plenums shown in FIG. 5 illustrating a perforated conveyor belt for conveying the substrate material past the in-line print head.

Claims

1. An apparatus for printing on a face surface of a substrate material, comprising: a print head spatially positioned relative to the substrate material for depositing ink on the face surface, andmeans for developing a pressure differential across a face surface of the substrate material such that a positive pressure is applied to a surface opposing the face surface and for supporting the substrate material as the print head deposits ink on the face surface.

2. The apparatus according to claim 1 wherein the means for developing a pressure differential includes: a plenum defining a chamber, the plenum enveloping the print head on at least two sides thereof and having a plurality of apertures through a wall of the plenum, the apertures disposed adjacent the face surface of the substrate material, anda vacuum source disposed in fluid communication with the chamber of the plenum,whereby the vacuum source is operative to develop the pressure differential across the face surface of the substrate material during ink deposition.

3. The apparatus according to claim 2 wherein the plenum circumscribes the print head.

4. The apparatus according to claim 2 wherein the plenum forms linear plenum segments disposed on each side of the print head.

5. The apparatus according to claim 1 further comprising an upper conveyor having a conveyor belt disposed between the plenum and the face surface of the substrate material.

6. The apparatus according to claim 5 wherein the conveyor belt includes a plurality of perforations therein to facilitate the development of a pressure differential across the face surface of the substrate material.

7. The apparatus according to claim 5 further comprising an lower conveyor having a belt contiguous with a lower surface of the substrate material for supporting the same at a predetermined distance relative to the print head.

8. The apparatus according to claim 2 wherein the substrate material defines a mailpiece envelope having first and second face surfaces and content material therebetween, and wherein the plenum develops the pressure differential across one of the face surfaces to separate the content material from the underside thereof thereby obviating surface irregularities during ink deposition.

9. The apparatus according to claim 1 wherein the plenum forms linear plenum segments disposed on each side of the print head and further comprising a means for separating the plenum segments to apply a tensile load across the face surface during ink deposition.

10. An apparatus for printing on a mailpiece having first and second face surfaces and content material therebetween and a print head for depositing ink on a face surface of the mailpiece, comprising: a device for spatially positioning the print head relative to the substrate material such that the substrate material is substantially orthogonal to the direction of ink deposition by the print head, anda plenum defining a chamber, the plenum enveloping the print head on at least two sides thereof and having a plurality of apertures through a wall of the plenum, the apertures disposed adjacent the face surface of the substrate material, anda vacuum source disposed in fluid communication with the chamber of the plenum,whereby the vacuum source is operative to develop the pressure differential across one of the face surfaces to separate the content material from the underside of the face surface thereby obviating surface irregularities during ink deposition.

11. The apparatus according to claim 10 wherein the plenum circumscribes the print head.

12. The apparatus according to claim 10 wherein the plenum is bifurcated to form linear plenum segments disposed on each side of the print head.

13. The apparatus according to claim 10 further comprising an upper conveyor having a conveyor belt disposed between the plenum and the face surface of the substrate material, the conveyor belt moving the substrate material past the print head during ink deposition.

14. The apparatus according to claim 13 wherein the conveyor belt includes a plurality of perforations therein to facilitate the development of a pressure differential across the face surface of the substrate material.

15. The apparatus according to claim 13 further comprising an lower conveyor having a belt contiguous with a lower surface of the substrate material for supporting a portion of its weight during ink deposition.

16. The apparatus according to claim 10 wherein the plenum forms linear plenum segments disposed on each side of the print head and further comprising a means for separating the plenum segments to apply a tensile load across the face surface during ink deposition.

17. A method for printing on a face surface of a mailpiece by using a print head for depositing ink, the method comprising the steps of: supporting the print head relative to the mailpiece such that the face surface thereof is substantially orthogonal to the direction of ink deposition by the print head,developing a pressure differential across a face surface of the substrate material such that a positive pressure is applied to a surface opposing the face surface to support the face surface of the mailpiece, andprinting on the face surface of the mailpiece.

18. The method according to claim 17 wherein the step of developing a pressure differential is performed by providing a plenum defining a chamber, the plenum enveloping the print head on at least two sides thereof and having a plurality of apertures through a wall of the plenum, the apertures disposed adjacent the face surface of the substrate material, and providing a vacuum source disposed in fluid communication with the chamber of the plenum, the vacuum source being operative to develop the pressure differential across the face surface to separate the content material from the underside thereof to obviate surface irregularities during ink deposition.

19. The method according to claim 17 further including the step of providing an upper conveyor having a conveyor belt disposed between the plenum and the face surface of the substrate material, the conveyor belt moving the substrate material past the print head during ink deposition.

20. The method according to claim 19 wherein the conveyor belt includes a plurality of perforations therein to facilitate the development of a pressure differential across the face surface of the mailpiece.

21. The method according to claim 19 further including the step of providing a lower conveyor having a belt contiguous with a lower surface of the substrate material for supporting a portion of its weight during ink deposition.

22. The apparatus according to claim 5 further comprising a registration wall disposed adjacent an edge of the mailpiece and a means for positioning the registration wall to change the position of the print head relative to the face surface of the mailpiece.

23. The apparatus according to claim 6 wherein the perforations of the belt and apertures of the plenum effect a substantially constant fluid flow as the belt moves across the plenum.

24. The apparatus according to claim 5 further comprising an lower conveyor having a belt contiguous with a lower surface of the substrate material for lightly supporting the weight of the substrate material.