Abstract: A method of increasing the reliability of an inkjet printer containing at least one pressure chamber provided with a nozzle for jetting ink drops therefrom and wherein when a disturbance in the pressure chamber is detected, the jetting of the ink drops is interrupted for a predetermined period of time. During this “waiting time” no active restoration operations are carried out, but rather the pressure chamber is left on its own to re-establish its normal operating condition prior to resuming the jetting of the ink drops from the nozzle.

Abstract: A melting device for melting an ink unit used in an inkjet printer, including a melting chamber provided with a wide end for dispensing the ink unit to the melting chamber and a narrow end, the melting chamber having a form such that the ink unit moves, as a result of melting, in a direction from the wide end to the narrow end, the ink unit being laterally enclosed with respect to said direction by one or more walls of a melting chamber, wherein the walls which form a lateral enclosure for the ink unit are heated, during the melting, to above a temperature at which the ink is liquid.

Abstract: An ink supply container defining an ink chamber wherein the ink supply container is provided with an ink filling opening leading into the ink chamber and an ink outflow opening leading out of the ink chamber, the ink outflow opening being suitable for connection to an inkjet printhead, the ink supply container further being provided with, or at least being connectable to, means for maintaining a negative pressure in the ink chamber. The ink chamber is separated from the ink filling opening by a porous material.

Abstract: An ink jet nozzle head including a substrate defining a nozzle and an ink channel connected to the nozzle, a diaphragm covering at least a portion of the ink channel, an actuator capable of deflecting the diaphragm, and a bump arranged for concentrating the force of the actuator that is applied to the diaphragm, wherein the diaphragm has at least two layers, and the bump forms a spacer for separating these two layers.

Abstract: An ink jet nozzle head including a channel plate defining a linear array of equidistanced nozzles and a plurality of substantially parallel ink channels communicating with an associated nozzle, a vibration plate disposed on the channel plate, a plurality of separately disposed block members, each containing a comb-like array of fingers which extend toward and engage the vibration plate, some fingers functioning as actuators for exerting mechanical pressure on ink contained in the ink channels, which in turn expels ink droplets from the nozzles, at least one actuator being provided for each nozzle, and the other fingers serving as support members, backing means mechanically interconnecting the actuators and support members, the support members supporting the channel plate and the backing means against the reaction forces of the actuators, the backing means comprising a separate backing member disposed over said array of fingers and being more flexible in the transverse direction of the ink channels than in the

Abstract: An exposure device comprising a straight row of substantially rectangular LED's, each LED comprising at least one non-emitting zone (34) having a width (a) which divides the LED into at least two equal parts (32, 33) having a width (c), a separating zone (35) of width (b) being situated between each of the LED's and the width (a) of the non-emitting zone (34) being smaller than 1.5 times the width (b) of a separating zone (35) and larger than 0.75 times the width (b) of the separating zone (35).

Abstract: An ink jet nozzle head including a channel plate defining a linear array of equidistanced nozzles and a plurality of substantially parallel ink channels communicating with an associated nozzle, a vibration plate disposed on the channel plate, a plurality of separately disposed block members, each containing a comb-like array of fingers which extend toward and engage the vibration plate, some fingers functioning as actuators for exerting mechanical pressure on ink contained in the ink channels which in turn expels ink droplets from the nozzle, at least one actuator being provided for each nozzle, and other fingers serving as support members for supporting the actuators at the vibration plate, where the reaction forces of the actuators are received, wherein each block comprises at least one actuator and at least one support member.

Abstract: Ink-jet system includes an ink channel between an ink reservoir and a nozzle. A pressurizing device is arranged adjacent to the ink channel for generating in the ink liquid an acoustic pressure wave propagating in the ink channel, so that an ink droplet is expelled from the nozzle. The ink channel has a substantially rectangular cross section and a depth d which is larger than the height of the nozzle, such that energy losses due to reflection of the acoustic wave at the transition from the ink channel to the nozzle are minimized. The pressurizing device includes a first electromechanical transducer with a plate-like expansible member having a height H in the direction of the depth of the ink channel such that the ratio H/d is smaller than the ratio between the respective elastic modules of the expansible member and the ink liquid.

Abstract: An ink-jet printhead includes a plurality of nozzles and ink channels arranged side by side, each nozzle being connected to an ink reservoir via its associated ink channel, and a plurality of electromechanical transducers, respectively, associated with each ink channel for pressurizing the ink liquid therein, so that an ink droplet is expelled from the nozzle. An active member is provided for compensating for the effect of the reaction force of each transducer by energizing at least one other transducer.

Abstract: An electro-optical scanning unit which comprises a linear LED array and a linear lens array for imaging slitwise onto a photoconductive drum with light is emitted by the LED's, and a holder for the lens array is connected by leaf springs to a holder for the LED array, the leaf springs connecting the holders in the middle of the arrays and at some distances therefrom and permitting adjustment of the lens array in a direction (Y-direction) perpendicular to the optical axis plane of the lens array and in a direction (Z-direction) parallel to said optical axis plane, the lens holder consisting of two parts which are glued to the lens array and which together form a diaphragm for the lens array.

Abstract: An exposure device in which a row of LED's is provided in the form of parallelograms having unequal sides, in which each of the corner points of one short side of a light-emitting surface is always in line, as considered in a direction perpendicular to the row, with one of the corner points of the other short side of an adjacent light-emitting element.

Abstract: An exposure device in which a row of LED's is provided in the form of parallelograms having unequal sides, in which each of the corner points of one short side of a light-emitting surface is always in line, as considered in a direction perpendicular to the row, with one of the corner points of the other short side of an adjacent light-emitting element, and a printing device in which said exposure device is used.

Abstract: An aging correction system for an LED array in a printer, in which each LED can be energized during a variable time and in which a light sensor, with which the relative light-output of each LED can be measured and compared with earlier measured values, is disposed near the array, and in which on the basis of these measured values a new correction value is determined.

Abstract: An exposure device for the image-wise exposure of a photosensitive layer by means of an LED array, whereby the cumulative loading of each LED over a specific time interval is determined, and on the basis thereof in a correction interval each LED is subjected to a specific extra loading equal to the difference between the maximum LED loadings and the subject LED cumulative loading so that at the expiration of the correction interval all the LED's have experienced equal aging.

Abstract: A method and means of exposing a movable light-sensitive layer by means of an array of LED's are disclosed. The invention comprises energizing for each image line and for a variable time each LED in the array symmetrically with respect to an imaginary line extending parallel to the array by using comparator circuits connected to a signal generator for a selected period of time used to generate a uniformly decreasing and increasing signal and to buffers for storing a corrected image signal so that the LED's are energized by the compared signal from an associated comparator circuit.