EP0401575A1 - Print head for ink jet recording apparatus - Google Patents

Abstract

The print head for ink jet recording apparatus has a plurality of jet nozzles (3) which are arranged in a row and are actuated electrothermally, two nozzles (3a, 3b, 3c) being connected in each case to one ink supply chamber (5), containing cyan-, magenta- or yellow-coloured ink, and the remaining nozzles (3d) being connected to an ink supply chamber with black ink. The function corresponds to that known for piezoelectrically operated ink recording apparatus, with the advantage of a considerably reduced space requirement. Applied in registration equipment operating according to the ink jet principle. <IMAGE>

Description

The invention relates to a print head for electrothermally pulsed ink jet recorders, in particular registering measuring devices, with a plurality of nozzles arranged in a row, into which channels fed with ink open. From DE-OS 29 45 658 a liquid jet recording method is known, in which a print head is formed in the manner specified above. The jet nozzles arranged in a row are connected via ink channels to an ink reservoir with black ink for printing alphanumeric characters. Controllable means for generating heat impulses are arranged in the channels, which form vapor bubbles and thereby eject ink droplets. For registering measuring devices with several measuring channels, it is required that each measuring channel be assigned a special distinguishable recording color, that alphanumeric characters can also be written and that the print head can be easily replaced with little space requirement.

This requirement is met by a write head of the type mentioned in the introduction, in which, according to the invention, two or more channels are each connected to an ink supply chamber for colored ink.

In a preferred embodiment for registration devices, two or three of the channels arranged in the print head are connected to ink supply chambers for yellow, cyan and magenta-colored ink. In addition to these three basic colors, three additional mixed colors (red, green, brown) can be obtained for the recording by simultaneously overlapping two or three of these colors. Three or more of the remaining channels are connected to an ink chamber for black ink and are used to record alphanumeric characters and coordinate lines on the recording medium.

• Figur 1: Der Schreibkopf 1 ist in bekannter und deshalb hier nicht im einzelnen gezeigten Weise aus mehreren Schichten aufgebaut.
  In seiner Stirnfläche 2 sind 24 Strahldüsen 3 senkrecht über­einander mit Abständen von 125 µm angeordnet, die an vier auf­steckbare Tintenzuführungen 4 für gelbe Tinte ge, cyanfarbige Tinte cy, magentafarbige Tinte ma und schwarze Tinte sw ange­schlossen sind. Die erste aus zwei Düsen bestehende Düsengruppe 3a ist mit gelber, die folgende, aus weiteren zwei Düsen be­stehende Düsengruppe 3b mit cyanfarbiger, die dritte, wieder aus zwei Düsen bestehende Düsengruppe 3c mit magentafarbiger Tinte und die Düsengruppe 3d mit den weiteren Düsen mit schwarzer Tinte beschickt.
• In Figur 2 ist die Zuordnung der Düsen und Farben schematisch dargestellt. In die in der Stirnfläche 2 des Schreibkopfs an­geordneten Düsen 3 münden Tintenkanäle 6, die über die Tinten­zuführungen 4 mit Tintenvorratsbehältern 5 verbunden sind. Die aus je zwei Düsen bestehenden Düsengruppen 3a, 3b, 3c dienen zur Aufzeichnung von sechs Meßkurven in den drei Grund- und den drei Mischfarben, die Düsengruppe 3d zur Beschriftung und zur Darstellung des Koordinatengitters auf dem Registrier­papier. Falls noch ein weiterer Meßkanal aufgeschaltet werden soll, können die ersten beiden Düsen der Düsengruppe 3d zur Aufzeichnung einer Meßkurve in schwarzer Farbe angesteuert werden.

To explain the invention, a write head is shown as an example in FIG. 1 and the assignment of the colors to the channels in the write head is shown schematically in FIG. 2 and described below.

• Figure 1: The write head 1 is constructed in a known and therefore not shown here in detail from several layers.
  In its end face 2, 24 jet nozzles 3 are arranged vertically one above the other at intervals of 125 μm, which are connected to four plug-in ink feeds 4 for yellow ink ge, cyan ink cy, magenta ink ma and black ink sw. The first nozzle group 3a consisting of two nozzles is supplied with yellow ink, the following nozzle group 3b consisting of further two nozzles with cyan colored ink, the third nozzle group 3c consisting again of two nozzles with magenta ink and the nozzle group 3d with the further nozzles with black ink .
• The assignment of the nozzles and colors is shown schematically in FIG. Ink channels 6 open into the nozzles 3 arranged in the end face 2 of the print head and are connected to ink supply containers 5 via the ink feeds 4. The nozzle groups 3a, 3b, 3c, each consisting of two nozzles, are used to record six measurement curves in the three basic and three mixed colors, the nozzle group 3d for labeling and for displaying the coordinate grid on the registration paper. If a further measuring channel is to be connected, the first two nozzles of the nozzle group 3d can be activated to record a measuring curve in black color.

Claims (2)

1. Print head for electrothermally actuated ink jet recorders, in particular for registering measuring devices with several arranged in a row, filled with ink and opening into nozzles, characterized in that two or more channels (6), each with an ink supply chamber (5) with colored Ink are connected. 2. Print head according to claim 1, characterized in that two or three channels (6) with ink storage chambers (5) for yellow (ge), cyan (cy) and magenta (ma) inks are connected and that three or more of the rest Channels with an ink supply chamber (5) for black ink (sw) are connected.

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