Incremental printing of symbolic information – Ink jet – Controller
Patent
1991-07-24
1995-09-19
Grimley, A. T.
Incremental printing of symbolic information
Ink jet
Controller
347 85, B41J 200
Patent
active
054519870
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The invention refers to an ink circuit particularly intended to pressurize a pigment ink for an ink jet printer.
BACKGROUND OF THE INVENTION
In marking techniques, for certain applications such as when supports are dark-colored, it is necessary to use inks with large amounts of pigments, such as titanium oxide particles, which make the ink opaque and white.
Using such an ink in standard machines causes several problems. We know that in an ink jet printing device using a continuous jet of ink drops, the drops must be led pressurized to an assembly called the modulation body, with a projection nozzle at its tip. Also, the ink drops not used for printing must be gathered and returned to the recovery reservoir to circulate again in the printing device. Printing quality of a printer of this type is closely related to the speed of ejection of the ink through the nozzle. This speed can be altered by varying the pressure upstream from the opening, as well as by a change in ink viscosity, which may be due to a loss by evaporation of the ink solvent which is often volatile.
As regards ink pressurization devices and those for recovering unused ink drops, it is common to see pumps implemented in a first type of machine. This is true of the ink circuit described in French patent no. 2,353,441 registered by the Applicant. In application with inks that are heavy in pigments, the disadvantage is that these pigments quickly alter the pumps, reducing their reliability. Moreover, pumps create cyclic variations in pressure that can harm printing quality.
There are devices that use pressurized gas reservoirs. This technique requires the use of buffer reservoirs to recover the ink drops in the transfer phase from recovery reservoir to main reservoir. An example of this is the ink circuit described in French patent no. 2,405,819. Having several of these reservoirs does not easily lend itself to circulating a pigment ink, since the pigment tends to be deposited by gravity at the bottom of the reservoirs. Finally, implementing pressurized gas reservoirs, usually of compressed air, also requires a second energy source for the machines using them.
BRIEF DESCRIPTION OF THE INVENTION
In addition to these problems there is, as was stated previously, that of ink viscosity. To solve this, the Applicant perfected a viscosimeter described in the above-mentioned French patent no. 2.353.441. The process used was to measure the time it takes to fill one reservoir from another by draining, under the force of gravity, the ink through a calibrated opening.
The goal of the invention is to mitigate the consequences of pumps or reservoirs of compressed air of the known type, while authorizing the implementation of the viscosity measuring procedure described in French patent no. 2.353.441. It involves a general ink circuit comprising a first pressurization circuit and a second depressurization circuit independent of the first, operating from means that never actually touch the ink. In this circuit, means of shaking the ink make it possible to prevent any risk of pigments settling where they can be most expected to.
More precisely the invention refers to an ink circuit for a continuous ink jet printing device particularly suited to the use of an ink loaded with pigments to turn it opaque and white. This circuit comprises, on the one hand, means to pressurize a reservoir (6) for feeding ink to the printing head and, on the other hand, means to depressurize a reservoir (2) for recovering ink drops not used during the marking operation; a viscosimeter (27) equipped with means (28) to measure viscosity; ink (1) and solvent (20) reserve reservoirs connected to the recovery reservoir (2) to provide additional ink or solvent as a function of variations in ink viscosity; the circuit is characterized in that this viscosimeter (27) is connected, on the one hand, by two ink circuits, one (45) to the accumulating reservoir (6) via electrovalve (23), the other (44) to the bottom of the recovery reservoir (2) via electrovalve (21) and
REFERENCES:
patent: 3761953 (1973-09-01), Helgeson et al.
patent: 4422085 (1983-12-01), Sumitomo et al.
patent: 4714931 (1987-12-01), Erskine et al.
patent: 4825228 (1989-04-01), Gloeckler et al.
patent: 4827278 (1989-05-01), Lecheheb
patent: 4862192 (1989-07-01), Slomianny
Patent Abstracts of Japan, vol. 5, No. 155 (M-90) (827), Sep. 30, 1981 & JP, A, 5682263 (Oki Denki Kogyo K.K.) Jul. 4, 1981.
Grimley A. T.
IMAJE
Ramirez Nestor R.
LandOfFree
Ink circuit particularly intended to pressurize a pigment ink fo 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 circuit particularly intended to pressurize a pigment ink fo, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ink circuit particularly intended to pressurize a pigment ink fo will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1831337