METHOD FOR CHECKING THE ALIGNMENT OF PRINT HEADS AND ASSOCIATED ALIGNMENT METHOD

摘要

The aim of the present invention is to propose a method for assessing and correcting the alignment of print heads carried out using at least one linear adjustment algorithm, allowing greater accuracy in the use of same by eliminating inaccuracies linked to the ejection of drops from the print heads, while limiting the use of the resources of the IT system on which the method is used. Moreover, the number of print heads of which the alignment needs to be assessed and optionally corrected has very little influence on the overall processing time required by said method.

主权项

1. A method for verification of the alignment of at least one printing head (1a, 10a, 1b, 10b, 1c, 1d) installed on a printing machine, by linear adjustment of at least one group of points (5) represented on an image originating from the digitisation of a model comprising a plurality of printed drops (4), wherein each drop (4) comprises a plurality of points (5), each point (5) having a uniform tint according to a colorimetric database saved in a memory area of a computer system (0) executing the method and comprising at least one memory space, means for acquisition, recording and processing of data, the method comprising:
a. a detection step of the colour of the points (5) by the processing means, followed by attribution by the processing means of spatial coordinates and colorimetric coordinates to each point (5) of a digital image of a model recorded in memory, these coordinates being respectively associated with a spatial coordinate relative to the image and a colorimetric table recorded in a memory space of the computer system (0), b. a creation step, by the processing means, of at least one list of points (5) of the same colorimetric coordinates, the data relative to at least this list being recorded in memory by the data-recording means, c. a creation step, by the processing means, of at least one group of points (5) of the same list of points of the same colorimetric coordinates and whereof each point (5) belonging to said group must be located at a distance less than a distance d/2 from a point (5) of another group, the distance d recorded in memory corresponding to the minimal distance between two groups of points (5), d. a filtering and removal step of groups whereof the number of points (5) is less than a limit value recorded in a memory area of the computer system, e. a vectorization step, by the processing means, of at least one group of points (5), followed by the recording in memory by the recording means of coordinates of at least one corresponding vector (50), f. an association step, via the processing means, of each vector (50) with the corresponding printing head (1a, 10a, 1b, 10b, 1c, 1d), a database connecting each printing head (1a, 10a, 1b, 10b, 1c, 1d) to a colorimetric coordinate being recorded in memory, and g. a comparison step, via the processing means, of coordinates of the vectors (50) with the coordinates of respective optimal vectors recorded in memory and characterising optimal alignment of the heads (1a, 10a, 1b, 10b, 1c, 1d).