Machine and method for multi-pass digital printing on glass sheets with minimised print travel

Abstract

Machine and method for multi-pass digital printing of plate glass with minimization of print travel. The machine is configured to recognize the longest dimension of the motif to be printed in the X and Y directions and to execute the multiple print passes by moving the bridge in the X direction or by moving the carriage along the bridge in the Y direction.

Claims

1. Multi-pass printing machine for plate glass with minimization of print travel of the kind that comprises a fixed structure to hold the glass by means of automatic positioning for the positioning and bracing of a sheet of glass during the printing, means of expelling the sheet of glass, and means of transporting the glass when no printing is happening, a print bridge disposed perpendicularly to the direction in which the plate advances wherein the print bridge can move in the X direction, a print carriage supported and configured to move along said bridge (Y direction) wherein the print carriage is configured with heads orientated to print during the bridge's movement along the X direction, and a central print processing and control unit, wherein: said print carriage comprises a main support with at least one print module oriented in the X direction, perpendicular to said Y direction, wherein said print module is fed by a colored ink, and said print module comprises at least one print head; said machine also comprises two motors, each motor including a high-precision micrometric encoder, said motors configured to control the movement of said bridge in the X direction; and a central unit configured to simultaneously order the movement of the bridge in the X direction, and the printing by said print heads.

2. Multi-pass printing machine, according to claim 1, wherein said central unit comprises: means for receiving data about the reference dimensions (X′,Y′) in the X and Y directions of the plate to be printed on; a piece of software for processing said data and determining the position information of the print heads on the “Y” coordinate (Y=f(X)) corresponding to each “X” ordinate; a module for transmitting the print signals to the print heads based on the information determined by said software; and, wherein: said carriage comprises an auxiliary support configured on the same working plane as said main support, with said auxiliary support comprising at least one print module oriented in the printing direction of the Y direction, and said print module is fed by ink of one color and comprises at least one print head, and such central unit is configured to simultaneously order, based on the greater of the reference dimensions X′ and Y′, the movement of the bridge in the X direction and the printing of the heads of the main support of the carriage; or alternatively, to simultaneously order the movement of the carriage in the Y direction and the printing, via the print heads, by the auxiliary support of the carriage.

3. Multi-pass printing machine according to claim 2, wherein both auxiliary and main supports are fixed together yet separately, and are configured to be removable, and said machine comprises a device for vertical movement of the carriage to the printing position.

4. Multi-pass printing machine according to claim 3, whereby an artificial vision system is included to recognize the data of two reference dimensions (X′,Y′) of the plate.

5. Multi-pass printing machine according to claim 2, whereby an artificial vision system is included to recognize the data of two reference dimensions (X′,Y′) of the plate.

6. Multi-pass printing machine according to claim 1, whereby an artificial vision system is included to recognize the data of two reference dimensions (X′,Y′) of the plate.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1: representation of the print passes with a multi-pass printing machine of the prior art in which the carriage moves along the bridge.

(2) FIG. 2: representation of the print passes with the machine subject matter of this invention in which the printing occurs through passes produced by the movement of the bridge.

(3) FIG. 3-A: top plan view of a multi-pass machine of the prior art with movement of the carriage along the bridge making the passes of FIG. 1. Seen in this figure are both the top plan view of its print carriage during the execution of a print, and the bottom plan view of said carriage when removed from the bridge.

(4) FIG. 3-B: close-up of the bottom plan view of the print heads in the carriage of FIG. 3-A.

(5) FIG. 4-A: top plan view of a machine subject matter of this invention with a print carriage with main support making the passes of FIG. 2. Seen in this figure are both the top plan view of its print carriage during the execution of a print, and the bottom plan view of said carriage when removed from the bridge.

(6) FIG. 4-B: close-up of the bottom plan view of the print heads in the carriage of FIG. 4-A.

(7) Seen in FIGS. 5-A and 5-B, respectively, are a front plan view of FIG. 4-A and a close-up view of the motors controlling the printing movement of its bridge.

PREFERRED EMBODIMENT OF THE INVENTION

(8) Details of an embodiment of this invention are given below.

(9) FIG. 1 shows the travel to be made by a prior-art printing machine with movement of a plate of glass (1) in the X direction, and movement of the carriage along the longitudinal axis of the print bridge in the Y direction. It is observed that, for a rectangular plate of glass measuring 6-meters long (in the X direction) by 1-meter wide, where each print pass is 70-mm wide, it would require 86 passes (marked in FIG. 1 as passes: 1, 2, 3, 4 through 28 to simplify the figure) to print the entire surface of said plate (86 passes in the Y direction×70 cm in width=6020 mm to cover the 6-meter length of the plate). If each pass takes 5 seconds, the total printing time would be 430 seconds (print speed of 330 mm/s plus+2 seconds of booting for each pass).

(10) FIG. 2 shows the travel which, on the plate of glass (1) of FIG. 1, is executed with an embodiment of the machine subject matter of this invention in which the bridge moves while a 70-mm-wide pass is made, requiring only 14 passes (marked in FIG. 2 as passes: 1, 2, 3, 4 through 14). The previous speed takes 20 seconds per pass, resulting in 280 seconds for the complete print, that is, 35% less time than in that of FIG. 1.

(11) FIG. 3-A shows the support structure (6) of a multi-pass printing machine, known in the prior art, supporting a plate of glass (1) on which a motif (5) is being printed by the print heads (33) of the print modules (32) of the print support (31) of the print carriage (3) (see FIG. 3-B). The print carriage (3) is supported and is movable by multiple passes in the Y direction along the bridge (2) while it prints the motif (5).

(12) FIG. 4-A shows the support structure (6) of a preferred embodiment of the multi-pass printing machine subject matter of this invention supporting a plate of glass (1) on which a motif (5) is being printed by the print heads (43) of the print modules (42) of the print support (41) of the print carriage (3) (see FIG. 4-B). The print carriage (3), supported by the bridge (2), is moved by multiple passes in the X direction by the movement of the bridge (2) while it prints the motif (5).

(13) FIG. 5-A shows the printing machine with the print carriage (3), the bridge (2), and the two motors (70) (on each side of the machine, which control the print movement of its bridge (2). FIG. 5-B shows a close-up view of one of the two motors (70) with the movement rails (71) on some guides (72) fixed to the structure of the machine, the coil (73), and the encoder (80). These two motors that move the bridge precisely are, for example, of the linear type, made by Tecnotion®, model TB30. Procedure and printing machine on rigid substrate.