BRPI0620792A2 - printing process applicable to printhead printing devices - Google Patents

Abstract

PRINTING PROCESS APPLICABLE TO HEAD PRINTING DEVICES A printing device with n print heads (A, B, C, D, etc.) is described which move together and are arranged with a separation (d) between their heads. centers, which prints on a printing ribbon impregnated with ink (X) that advances when the heads (A, B, C, D, etc.) are stopped, and that stops when the print heads (A, B, C, D, etc.) print the same, and where the ribbon X is divided into sectors of length 1. The printing by the heads (A, B, C, D, etc.) is done by moving the ribbon a distance d + 1 in order to optimize the operational times, using at the same time all sectors of ribbon X in the printing process.

Description

"PRINTING PROCESS APPLICABLE TO HEAD PRINTING DEVICES"

PURPOSE OF THE INVENTION

The present invention relates to the area of printing devices equipped with multiple printheads, especially those for continuously printing a membrane.

The object of the invention relates to a process for printing on an ink-impregnated printing ribbon that transfers ink to a membrane or substrate. The invention is to obtain an optimized sequence of moves to advance the ribbon in coordination with the print head of the print device to achieve faster print speed using the ribbon, reducing the time required. I am.

BACKGROUND OF THE INVENTION

Various printing devices are known, in which in general the substrate or membrane to be printed is supplied with a stepper motor operated carriage and a printing head with the aid of an ink impregnated ribbon. , a picture or caption, for example, on the membrane each time it stops.

The print ribbon is the object on which the print head initially prints to transfer ink to the transversely moving membrane.

The print ribbon usually advances the length required for printing in the next free section to prevent overprinting in two successive sectors. The use of a single print head greatly limits ribbon performance since each time the ribbon stops printing occurs in sectors adjacent to the previously printed, and then the number of times this happens when printing all the media. sectors on the tape is finally very high.

To speed up the printing process, several heads are used which are arranged evenly and equidistantly above where the ribbon feeds, where all the heads operate at the same time, printing on different sectors of the ribbon. The heads print on the ribbon in a downward, translational motion, then retract to allow the ribbon to advance.

Since the heads are spaced, the marks obtained on the initial print are also spaced so that the ribbon has to move so that the next print will occur in the unprinted sectors intermediate between these marks.

Several solutions are already known for print dynamics, depending on the area in which printing occurs, as well as the device itself, and depending on the design that should be printed by each head.

One of the most common print sequences used in multi-head printing devices is to move the ribbon step by step to a length that, at each step, is the same length as the printing industry. Thus, the ribbon is printed until all of its intermediate sectors between the already printed marks have been covered and the ribbon then moves at a length that is equal to the sum of the head distances plus that of a print. reprint on a virgin tape length following the above sequence.

This printing method can be optimized since the time taken for this last ribbon movement is especially long and delays the continuous printing process.

DESCRIPTION OF THE INVENTION

The printing process proposed in the present invention allows S sectors to be printed by means of n printheads on an ink-impregnated ribbon from which ink is transferred from the membrane which must be printed in such a way that it can be printed. optimal use of the total ribbon surface, reducing operating times and thus giving greater performance through the printing process.

The printing process applies to a n-printhead printing device whose centers are equidistant in the distance d, which decreases and moves with each print stroke on the ribbon, setting a print length that is shorter or shorter. equal to length 1 of the sectors S into which the print ribbon is divided.

The printing process involves the following steps described below:

a) Perform printing using the n heads on the ribbon, defining print sectors of length a.

b) The movement of the membrane at a distance d + 1.

(c) consecutive execution of operations (a) and (b). Since:

[*] n ≤ d / l + 1,

where n ≥ 2.

Through this printing process, uneven advances are avoided, some of them long-lasting, as was previously the case; since the feed rate is the same with each step of the same size d + 1, which ultimately considerably reduces the operating time of the printing device.

DESCRIPTION OF DRAWINGS

To supplement the description being conducted and to improve understanding of the features of the invention, according to a preferred example of its practicality, this description is made by a set of drawings, which form an integral part. said description and illustrating it without limiting it;

Figure 1 shows a diagram of successive prints on the ribbon for different ink ribbon feeds according to the printing process for a three-head printing device.

Figure 2 shows the diagram of figure 1 for a five-head printing device.

PREFERRED EMBODIMENT OF THE INVENTION

Referring to the above figures, the printing process is described for application to a printing device equipped with more than two print heads (A, B, C, D, etc.) printing on the print ribbon. X-impregnated ink below the printheads, and which moves in a longitudinal direction when the printheads (Α, Β, C, D, etc.) are stopped, and stops when the printheads ( A, B, C, D, etc.) print on it, transferring the ink to a membrane or substrate that moves in a transverse direction.

Figure 1 shows a three printhead (A, B, C) printing device in which it can be seen that the distance between its centers is defined by d. The print ribbon is divided into S sectors of a length 1 where marks are printed by the heads (A, B, C) with a print length less than or equal to length 1 of the S sectors. In this case, for three heads according to the formula [*], it is found that η ≤ d / l + 1, where d ≥ 21.

Figure 1 shows that at time t the heads (A, B, C) descend and move over the tape, imprinting the marks (Al), (BI), (Cl), each of which have a length a, the print heads (A, B, D) then rise, allowing subsequent movement of the ribbon, which advances a distance d + 1 until it stops some time later t2 at which the heads (A, B, D ) print marks (A2), (B2), (C2) again on print ribbon X.

As can be seen from Figure 1, according to this process, and for the proposed number of print heads, all spaces on the ribbon are marked, giving a used ribbon full of contiguous marks at the point where the print head Leave the tape.

Figure 2 shows the process for a 5-head device in which, according to formula [*], it appears that for η = 5, the ratio d ≥ 41. In this case, printing is performed at X print ribbon divided into S sectors of length 1 by means of the printheads (A, B, C, D, E). At time tl with the printhead X stopped, the marks (Al), (BI), (Cl), (Dl), (El) are printed on it and the ribbon advances at a distance of d + 1, and it stops to allow printing by the print heads (A, B, C, D, E) again for another time t2, giving the marks (A2), (B2), (C2), (D2), (E2 ) and so on until time t4 at which all contiguous sectors S have been marked on tape X leaving the printing device. This sequence continues indefinitely, the output of the tape with all its printed S sectors being ensured.

In all cases shown, the length of each print a will be less than or equal to the length 1 of each S sector of tape X.

Claims (2)

1. Printing process applicable to printing devices with η print heads (A, B, C, D, etc.) arranged equidistantly with a separation d between their centers, which print on an ink ribbon (X) that is divided in contiguous sectors (S) in length (1) and is placed under the printheads, and which advances in a longitudinal direction when the heads (A, B, C, D, etc.) are stationary and stops when the heads ( A, B, C, D, etc.) are printing on it, transferring ink to a membrane or substrate that moves in a transverse direction, CHARACTERIZED by the fact that it has the following steps: a) Making an impression by print heads (A, B, C, D, etc.) on ribbon (X), defining printed sectors (Al), (Bl), (Cl), (Dl) ... of length a, b) tape (X) at a distance d + 1, (c) consecutive execution of operations (a) and (b) on tape X, provided that n ≤ d / l + 1, where n ≥ 2.