GB1566988A - Ink-jet printers - Google Patents

Description

(54) INK-JET PRINTERS (71) We, ITT CREED LIMITED, a Brit ish Company, of Crowhurst Road, Hollingbury, Brighton 6, Sussex, England, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to ink-jet printers.

By this term is meant a printer of the kind in which printing is performed by directing a jet or stream of droplets of ink onto a record medium.

Non-impact printers, such as ink-jet printers, do not have the ability to produce a plurality of copies of recorded matter by means of carbon paper or the like. Obviously it would be uneconomical to provide a complete printer for each copy required, and it cannot be guaranteed that there will always be a handy photo-copier on which to make as many copies as are required of the single record produced by a single printer.

Until recently non-impact printheads have been rather bulky, but recent developments have produced ink-drop printheads which are quite thin, measured perpendicularly to the record web.

According to the present invention there is provided an ink-jet printer capable of producing multiple copies of a record, the printer comprising: a plurality of ink-jet printheads movable in register with each other, and a like plurality of record web guide channels which constrain record webs ted into them to diverge sufficiently to accommodate a corresponding printhead in a position to print on each web; common driving means for traversing the heads in relation to the webs; and common signal processing means for sending the same print signals to each printhead simultaneously; whereby each printhead makes a copy of matter to be printed on its corresponding record web so that each copy if substantially identical to every other copy.

An embodiment of the invention is described below with reference to the accompanying drawings, of which: Figure 1 shows the basic arrangement of a plurality of ink-drop printheads which traverse a like plurality of record webs in unison; and Figure 2 shows a side view of a practical arrangement of such a set of printheads and record webs.

A plurality of ink-jet printheads, 1A, 1B, 1C, is shown in Figure 1. Each printhead is traversed across a corresponding record web, 2A, 2B, 2C by a corresponding cord or belt, 3A, 3B, 3C, driven by respective pulleys, 4A, 4B, 4C, mounted on a common driving axle 5 located at one edge of the webs. Corresponding pulleys, 6A, 6B, 6C, on a further common axle 7 to support the cords or belts or located at the other, opposite, edge of the webs. Flexible pipes to carry ink to and from the printheads, and flexible electrical leads to actuate the print head ejaculation arrangement are also attached to the printheads but, for the sake of clarity, are not shown. Suitable arrangements for preventing these pipes and leads from becoming entangled with the belts or cords or the webs are well known to those skilled in the art.The heads are so positioned relative to the record webs that they are, at all times, at the same distance as each other from a given datum, such as the left edge of the webs. The ejaculating arrangement on each head is controlled by a common signal so that all the heads ejaculate ink-drops at the same time and therefore make corresponding marks on the record webs at the same place. Thus, whether the heads are of the kind which build up characters a line of dots at a time as in line printers, or build up each character separately, as in serial printers, the result is a plurality of copies, all "top copies". Three are shown in this embodiment but larger or smaller pluralities are feasible.

In Figure 2 is shown a side view, in section, of a printer making three copies in accordance with this embodiment. Paper from a three-ply roll of paper 21 (record web) is fed through rollers, 22A, 22B, 23A, 23B, to channels between web guides, 24A, 24B, 24C, 24D. Only ply passes through the channel between guides 24A and 24B; a second ply passes through the channel between guides 24B and 24C; and the third ply passes through the channel between guides 24C and 24D. The guides are so shaped that the three plies diverge from each other.

Three printheads, 25A, 25B, 25C, are positioned so that each prints on a corresponding ply of paper, and are driven and operated as already described and shown in Figure 1. A hinged cover 26 allows access to the entrances to the guides so that the plies of paper may be inserted therein. The guides 24A, 24B and 24C each carry a corresponding tear edge, 27A, 27B, 27C. by which the plies, when printed, can be cleanly detached from the printer.

By supplying the heads with different coloured inks, each copy may be printed in its own colour.

One advantage such a printer has over an impact printer is that if one printhead fails, there are still some copies printed, whereas the failure of an impact printhead means that all copies are affected.

WHAT WE CLAIM IS: 1. An ink-jet printer capable of producing multiple copies, the printer comprising, a plurality of ink-jet printheads movable in register with each other, and a like plurality of record web guide channels which constrain record webs fed into them to diverse sufficiently to accommodate a corresponding printhead in a position to print on each web; common driving means for traversing the heads in relation to the webs; and common signal processing means for sending the same print signals to each printhead simultaneously; whereby each printhead makes a copy of matter to be printed on its corresponding record web so that each copy is substantially identical to every other copy.

2. A printer as claimed in claim 1 wherein different coloured inks are supplied to each head whereby copies are printed each in their own colour.

3. An ink-jet printer substantially as described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. are shown in this embodiment but larger or smaller pluralities are feasible. In Figure 2 is shown a side view, in section, of a printer making three copies in accordance with this embodiment. Paper from a three-ply roll of paper 21 (record web) is fed through rollers, 22A, 22B, 23A, 23B, to channels between web guides, 24A, 24B, 24C, 24D. Only ply passes through the channel between guides 24A and 24B; a second ply passes through the channel between guides 24B and 24C; and the third ply passes through the channel between guides 24C and 24D. The guides are so shaped that the three plies diverge from each other. Three printheads, 25A, 25B, 25C, are positioned so that each prints on a corresponding ply of paper, and are driven and operated as already described and shown in Figure 1. A hinged cover 26 allows access to the entrances to the guides so that the plies of paper may be inserted therein. The guides 24A, 24B and 24C each carry a corresponding tear edge, 27A, 27B, 27C. by which the plies, when printed, can be cleanly detached from the printer. By supplying the heads with different coloured inks, each copy may be printed in its own colour. One advantage such a printer has over an impact printer is that if one printhead fails, there are still some copies printed, whereas the failure of an impact printhead means that all copies are affected. WHAT WE CLAIM IS:

1. An ink-jet printer capable of producing multiple copies, the printer comprising, a plurality of ink-jet printheads movable in register with each other, and a like plurality of record web guide channels which constrain record webs fed into them to diverse sufficiently to accommodate a corresponding printhead in a position to print on each web; common driving means for traversing the heads in relation to the webs; and common signal processing means for sending the same print signals to each printhead simultaneously; whereby each printhead makes a copy of matter to be printed on its corresponding record web so that each copy is substantially identical to every other copy.

2. A printer as claimed in claim 1 wherein different coloured inks are supplied to each head whereby copies are printed each in their own colour.

3. An ink-jet printer substantially as described with reference to the accompanying drawings.