WO1986002884A1 - Method for the control of an ink jet printing head and flexible workshop provided therewith - Google Patents

Abstract

The method for the control of a printing head comprises the formation of printing subsystems (M1, M2, M3) each comprised of a supply block (CE) to which are associated, within the subsystem in question, one, two or three heads (T) provided with a proper computation unit and having similar or different characteristics. A bus (10) interconnects on one hand said subsystems, and on the other hand the supply blocks (CE) and the heads (T). The bus (10) also connects the assembly to a control console (30) which is itself connected with a host computer (40). It may also connect the assembly optionally to external information means such as a video camera (50) or a laser reader (51). The invention may be applied to the installation of flexible printing workshops.

Description

 PRINTHEAD CONTROL METHOD

INKJET AND FLEXIBLE WORKSHOP

SO EQUIPPED

The invention relates to a method for controlling an ink jet print head. It also concerns any flexible workshop equipped according to this process. The so-called inkjet technique allows a wide variety of printing characteristics, both in terms of the smoothness of the characters and in terms of color or number of jets. In addition, it makes it possible to mark practically any type of support whatever its shape, its nature or its size.

However, a big problem arises when we want to remotely control one or more heads of i mpres.sion. We can then have recourse to a centralized control method whose implementation structure can be described as tree-like. Such a process leads to extremely heavy, costly and difficult to control installations.

The present invention aims to overcome these drawbacks and relates to a control method which makes it possible to associate a theoretically infinite number of independent writing heads and to program them from a single entry point or not .

It relates more precisely to a method for controlling a plurality of printheads, characterized in that it consists in creating f) printing "subsystems" consisting of a "power supply" of at least one "print head", the link between the "subsystems" on the one hand, between the "power supply" and the "print heads" on the other hand, a keyboard for controlling the assembly and an external computer, being made by a bus. The invention also relates to any flexible printing workshop using a plurality of such printing subsystems.

The invention will be better understood with the aid of the explanations which follow and of the appended figures among which:

FIG. 1 schematically illustrates an architecture of means Q implementing a method according to the invention. FIG. 2 illustrates a bus as used in accordance with the invention. The method according to the invention illustrated by means of FIGS. 1 and 2, consists in creating subsystems called "printing subsystems" in the following description and referenced (M) generally with or without index . Each of these printing subsystems (M) is essentially made up of a "power supply unit" (CE) ensuring the electrical supply and ink of at least one "print head" (T ) which, according to a characteristic of the invention, is provided with its own calculation unit (TC). In Figure 1, there is shown by way of non-limiting example, three types of such printing subsystems. (M). The one referenced (Ml) has a single head (T). The other referenced (M2) has two heads (T). The third referenced (M3) has three heads (T).

According to an important characteristic of the invention, within a printing subsystem (M), the printheads (T) may have identical or different characteristics relating in particular to the size and the fineness of the characters , on the color and on the number of associated jets in the same head ...

According to the invention, the connection between the subsystems (M) on the one hand, "the power supply and the print heads" on the other hand, is ensured by means of a bus 10. This the latter is of a conventional type with two twists 11 and 12, one known as a "given pair" and the other a "tensioned pair", shielded in a sheath 13.

According to a characteristic of the invention, it is thus possible to produce flexible printing workshops and to adapt the number and the characteristics of each printing subsystem (M) to the applications considered. These subsystems connected together in series by bus 10, can be spaced from each other over distances of up to 500 meters. The bus 10 connects the assembly defined above to a control console 30 consisting for example of a keyboard 31, itself connected by said bus to a module 32 of I / O input / output interface, associated with a calcula¬ outside designer 40 says host computer. Each of the devices controlled by the bus 10 is provided in a known manner with a bus interface circuit (not shown).

According to another characteristic of the invention and as shown Figure 1, in the context of alternative embodiments, in series with the control means (console 30 - computer 40) and the printing subsystems (M), can be mounted information means other than the means who can react on them. For example, there is shown in FIG. 1, a video camera 50, intended for reading directly the printed characters and a Laser reader 51 capable of reading a bar code.

Plugs 60, 61 placed at the input and at the output make it possible to close and tune the impedance of the bus 10. The present invention has numerous applications, particularly whenever it is advisable to group by one, two or three, the print heads on the same lines of products to be marked or on different lines. It allows a relatively large spacing between the different marking modules.

Claims

1) Print head control method, characterized in that it consists in creating "printing subsystems" (M) consisting of a "power supply unit" (CE) of at least one "print head" (T) with its own calculation unit, the link between the print subsystems (M) on the one hand, between the "power supply" (M) and the "print heads" (T) on the other hand, a console (30) for controlling the assembly and an external computer (40), being made by a bus (10). 2) Flexible printing workshop, characterized in that it is equipped with a plurality of printing subsystems (M) according to claim - _. connected in series with each other, said bus (10) also providing the connection to the console (30) and to the computer (40). 3) Flexible workshop according to claim 2, characterized in that the printing subsystems (M) are equipped with one to three printing heads (T) having different characteristics. 4) Flexible workshop according to one of claims 2 and 3, characterized in that information means are mounted in series on the bus (10). _ * 5) Flexible workshop according to claim 4, characterized in that these information means consist of a video camera (50) capable of reading the printed characters directly. 6) Flexible workshop according to claim 4, characterized in that these information means are constituted by a laser reader (51) capable of reading a barcode.