Incremental printing of symbolic information – Ink jet – Fluid or fluid source handling means
Reexamination Certificate
2000-01-12
2001-10-30
Nguyen, Judy (Department: 2861)
Incremental printing of symbolic information
Ink jet
Fluid or fluid source handling means
Reexamination Certificate
active
06309061
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a device for delivering ink, more particularly on a print head for an ink jet printer, provided with a series of ink delivery nozzles which can be actuated selectively in the printing of a sheet of paper or the like. The present invention also relates to an ink jet printer provided with such a device.
A known printer head is provided with a base body or base plate with two flat sides and a head surface, and a series of parallel ink ducts provided in each side and merging near the corner to the head surface into ink tunnels which extend through the base body to the head surface. The ink ducts originate from an ink distribution chamber provided in the associated side and connected via an internal passage to the ink inlet provided in the body. To prevent any irregularities from occurring in the ink ducts and then obstructing the throughflow, a filter is provided in the distribution chamber at the downstream end of the passage between the inlet and the distribution chamber. This filter is placed in the distribution chamber from the exterior, after which a foil is placed over the ink ducts and over the distribution chamber.
One disadvantage of this arrangement is that air bubbles liberated in the distribution chamber can readily enter the ink passages and in the long term may interfere with the ink delivery in the associated ink passages. If the filter becomes clogged, ink may be withdrawn from a neighbouring duct.
SUMMARY OF THE INVENTION
The object of the present invention is to provide an improvement in this respect. To this end, according to one aspect of the invention, there is provided a device for delivering ink to a sheet of paper or the like, comprising a body with sides and a head end disposed at an angle to the sides and containing an inlet for the ink originating from a reservoir. A plurality of ink delivery nozzles are provided at the head end and a plurality of ink passages extend between the inlet and the ink delivery nozzles, along one or more of the sides, with means located at the ink passages on that side for the selective propulsion of ink therethrough to the ink delivery nozzles. Filter means are provided between the reservoir and the ink passages and are disposed in a distribution chamber directly at the upstream end of the ink passages.
Thus a (secondary) filter is created for each ink passage, so that when passing to the ink passages not only are any impurities removed from the ink but, in addition, any air bubbles in the ink are prevented from flowing in the ink passages. The possible mutual influence of the pressures in the ink passages is also greatly minimised by the closure provided by the filter with respect to the upstream inlets of the ink passages, and the filter therefore has an excellent restricting effect.
It should be noted that U.S. Pat. No. 4,364,067 discloses a print head having a substantially triangular base body or base plate, in cross-section, disposed with the apex towards the paper for printing and provided at the top with two ink inlets situated at the top ends of the oblique sides and communicating with an ink reservoir. Each of the inlets leads by internal passages to an ink distribution chamber to which there is connected a number of ducts disposed in the associated oblique side. These ducts converge with an arc in the plane of the associated oblique side towards a plurality of obliquely directed ink delivery nozzles. Grooves are formed in the upstream ends of the ducts by means of which the ink is filtered. A disadvantage of this construction is that the making of the grooves in the ducts requires considerable care.
In another feature of the present invention, the distribution chamber is disposed on the outside of the body and the ink passages are separated from the distribution chamber by means of a layer of material which is disposed on the body and in which filter passages are provided which correspond to the ink passages. Thus use is made of the chosen position of the secondary filter in order to simplify the body since there is no need for any passages between the inlet and the distribution chamber. In fact, the filter passages then form the inlet to the body.
In another feature thereof, the ink propulsion means comprises selectively actuatable piezo-electric elements, wherein an ink-tight layer, such as a suitable foil, extends between the piezo-electric elements and the ducts, wherein the ink-tight layer is formed as a unit with the layer of material provided with filter passages. Thus the filter can be mounted in one operation with the ink-tight layer for the ink propulsion means.
Preferably, the ink delivery nozzles are formed by the same ink-tight layer provided with a number of ink delivery passages in line with the ends of the ink passages and extending through the layer.
Advantageously, the body is provided with two opposite sides in which the ink passages provided with filter means are disposed in a comparable manner. If the ink passages over the path extending from the filter means to the ink delivery nozzles are formed as through ducts in the associated side and in the adjoining head end of the body and are covered by the same ink-tight layer, one and the same ink-tight layer can disposed (with a filter) around the body in order to perform a plurality of functions, simultaneously.
REFERENCES:
patent: 4364067 (1982-12-01), Koto et al.
patent: 4514743 (1985-04-01), Roschlein et al.
patent: 4689641 (1987-08-01), Scardovi et al.
patent: A10867289 (1998-09-01), None
patent: 60-198255-A (1985-10-01), None
patent: 63-260447-A (1988-10-01), None
patent: 4-99634 (1992-03-01), None
Patent Abstracts of Japan, JP 04 099634 A (Seikosha Co Ltd), Mar. 31, 1992.
Patent Abstracts of Japan, JP 59 167267 A (Nippon Denki KK), Sep. 20, 1984.
Patent Abstracts of Japan, JP 01 186331 A (Ricoh Co Ltd) Jul. 25, 1989.
Brugman Wilhelmus Theodorus Johannes
Hollands Peter Joseph
Stolk Hendrik Jan
Birch & Stewart Kolasch & Birch, LLP
Nguyen Judy
Oce--Technologies B.V.
LandOfFree
Ink jet array does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ink jet array, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ink jet array will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2572144