Abstract: Disclosed are a jet ink composition and a method for printing on glass, plastic, and metal surfaces messages having good adhesion and alcohol rub resistance, said composition comprising an organic solvent, a flexible thermoplastic urethane resin, a colorant, a cellulose nitrate resin, and an adhesion promoter.

Abstract: A continuous ink jet printing system for use with a hot-melt ink, comprising a supply chamber for retaining said ink in a liquid form, means for applying heat to the ink in said chamber to maintain said ink in a liquid form, means for conveying said ink in liquid form from said chamber to a printhead for projection toward a substrate to be marked, catcher means for collecting any of said ink that is not directed to said substrate, means for returning the collected ink as a liquid to the supply chamber, and means for maintaining the ink as a liquid while it is being returned to said supply chamber.Also disclosed is an ink jet nozzle for use in printing hot-melt inks at elevated temperatures comprising an ink jet nozzle body, a transducer, means for acoustically coupling said transducer to said body, and means for maintaining said transducer acoustically coupled to said body at elevated temperatures.

Abstract: A system and method for detecting a latent image formed with an invisible ink. A mechanism, such as a heater for heating the ink, provides a temperature differential between the ink and the substrate. An ink delivery system such as an ink jet printer applies the ink to the substrate to form a latent image thereon. A heat-sensitive scanning device scans the substrate and outputs an electrical signal corresponding to the temperature differential between the ink and the substrate before the ink reaches thermal equilibrium with the substrate. The electrical signal includes information representative of the image on the substrate, and may be displayed, recorded and/or processed as desired to verify the image.

Abstract: The present invention provides jet ink compositions that are free or substantially free of sedimentation, have good image adhesion and rub resistance, and that are suitable for printing messages on food items such as fruits, vegetables, chocolate, candies, confectioneries and pharmaceuticals such as tablets, and other edible or ingestible materials. The jet ink compositions comprise a surface modified or coated colorant. The surface modified or coated food grade colorant comprises a food grade colorant of particle size in the range of from about 0.01 micron to about 25 microns, a colorant carrier, and a surface modifying or coating agent. The surface modifying or coating agent comprises at least one binder resin, and preferably two or more binder resins.

Abstract: Disclosed is a jet ink composition suitable for printing marks on metal, glass, plastics, rubber, or paper comprising an ink carrier, a fluorescent colorant, a cellulosic binder resin, and a tetraalkyl ammonium or phosphonium salt. The jet printed marks do not blush, bleed, or fade, as a result of exposure to steam, or hot and cold water. Also disclosed is an improved process of jet printing on substrates comprising printing with the disclosed jet ink composition.

Abstract: An electrically-controllable liquid crystal filter device comprises two partially-reflecting substrate structures mounted substantially parallel to each other with a space therebetween to form a Fabry-Perot filter. A layer of ferroelectric liquid crystal material is disposed in the space, the liquid crystal material being switchable, by application of an electric field, between different refractive index values whereby the device is switchable between transmissive and reflective states for light of a particular narrow wavelength band. The spacing of the substrate structures is selected in relation to the wavelength of light to be transmitted, such that the Fabry-Perot filter operates in a low order state, which may be the first order.

Abstract: Encapsulated particles, such as magnetic particles, colored pigments, or carbon black, with high chemical affinity for ink vehicles. The encapsulated particles of this invention are suitable for printing inks, as well as for magnetic recording systems, such as audio and video tapes and magnetic storage disks, when the encapsulated particles are magnetic particles. The encapsulated particles comprise particles having a coating on their surface, said coating comprising in one embodiment an ionomer and in another embodiment, an oil, such as soya oil, and optionally a thixotropic agent, and/or a binder resin. The method of the present invention for making such encapsulated particles avoids the use of volatile organic solvents and provides printing inks and coating compositions comprising such encapsulated particles, that also avoid the use of volatile organic solvents.

Abstract: Disclosed are a jet ink composition and a method for printing on wet glass, PET, and aluminum surfaces under humid conditions messages having good penetration, adhesion and abrasion resistance, said composition comprising an organic solvent, a flexible thermoplastic urethane resin, silicone resin, a silane, and a colorant.

Abstract: An apparatus and method for producing a stream of ink drops in a continuous ink jet printer having a maximum allowable number of fast satellite drops. An ink, which may be a hot-melt ink in its liquid phase, is pressurized for continuous flow to a nozzle and a rectangular or triangular waveform is generated at a fixed frequency. The waveform is applied to a transducer coupled to the nozzle such that nozzle vibrates and the ink flow is perturbed and discharged from the nozzle as primary drops with satellite drops formed therewith. The harmonic content of the rectangular or triangular waveform is adjusted until the desired number of fast satellite drops suitable for desired image formation are formed in the stream of primary drops. In a preferred embodiment, the desired number of fast satellites is a maximum of three.

Abstract: The present invention provides an ink composition for use in printing on food items, especially fruits and vegetables, and a method of forming printed images on food items by use of such compositions. The compositions of the present invention comprise citrus #2 dye, at least one binder, such as a rosin resin or cellulose derivative, and a carrier comprising ethanol and acetone. The composition is also characterized as being MEK-free, as well as water-free.

Abstract: A temperature control unit is incorporated directly into the printhead of an ink jet printing system to provide temperature control. The temperature control system includes a heat pump assembly consisting of at least one thermoelectric device, coupled to a heat exchanger through which the ink flows. The thermoelectric device conveys heat to or from the heat exchanger carrying the ink depending upon actual ink temperature versus a desired temperature. If the ink is too hot, excess heat is dumped to a heat exchanger (or second heat exchanger) which may be air or liquid cooled. In the event that the ink is too cool, the electrical current to the TED is reversed and heat is pumped to the ink from the heat exchangers.

Abstract: The present invention provides jet ink compositions that produce on glass, metal, plastic, and rubber surfaces messages having high visual intensity, and condensation and water resistance. The inventive compositions comprise a polyamine, a colorant, and an acidic resin. The present invention further provides jet ink compositions further comprising water as the ink carrier. The colorant used in the ink composition of the present invention includes a dye, a pigment, or a polymeric hollow microsphere. The polyamine used in the ink composition of the present invention includes a dendrimer. The ink composition of the present invention may additionally include pH adjusting agents, humectants, biocides, defoamers. The present invention further provides an improved process of jet printing on glass, metal, plastic, and rubber surfaces messages having improved condensation and water resistance, and improved visual intensity, the improvement comprising using the ink composition of the present invention.

Abstract: Disclosed are a jet ink composition and a method for printing on glass, plastic, and metal surfaces messages having good adhesion and isopropyl alcohol rub resistance, said composition comprising an organic solvent, a flexible thermoplastic urethane resin, a colorant, a cellulose nitrate resin, and an adhesion promoter.

Abstract: An ink jet droplet generator is described, including a nozzle plate bonded to a carrier. A tuned piezo crystal and metal structure projects into an ink cavity and is mounted on a print head structure. The nozzle carrier is separated by a spacer from the print head structure and seals are provided to seal the cavity. A pillar is provided with a height slightly greater than that of the spacer between the print head structure and the nozzle carrier. The spacer is isolated from the print head structure, pillar and nozzle carrier by seals and O-ring which surrounds the pillar. In another embodiment, layers of acoustically absorbent material are provided between the spacer and each of the print head structure and nozzle element.

Abstract: The ink level sensor of the invention comprises an ink container having a generally cylindrical shield extending downward from its top to define shielded and unshielded compartments within the container. Ink, but not foam, froth or mist, flows under the shield to the shielded compartment. A plurality of conductive rods of differing length extend downwardly into the shielded compartment from the container top. The rods are connected to an impedance network which provides signals representative of the ink level inside the container. A vacuum source can be connected to each compartment to maintain pressure equilibrium in the compartments and to prevent foam, froth or mist from entering the shielded compartment. Alternatively, a return pump is used to force ink into the container such that each compartment can be vented to the atmosphere.

Abstract: A charging electrode assembly for a continous multi-jet ink jet printer includes a substrate plate 1 of electrically insulated material provided with a series of parallel electrodes 5 extending across an edge of the plate and a series of parallel strip leads 6 extending across a face of the plate. The plate is formed with grooves, plated with metal, and then the faces of the plate are ground to leave the electrodes and strip leads in the grooves. Alternatively, the surfaces of the plate are metal plated and then grooves are cut in the edge and face of the plate to leave the electrodes and strip leads between the grooves. An independent feature of the invention recides in the provision of one or more eccentric dowels working in elongate slots in the plate so that rotation of the dowels provides fine adjustment of the plate, and hence of the electrodes relatively to trains of ink droplets.

Abstract: A segmented charge tunnel for ink jet printing having a plurality of individual segments is utilized to sequentially apply charges to a droplet stream. Precise location of the stream break-off point within the tunnel is accomplished by identifying which one of the segments of the charge tunnel is associated with the detection of a maximum charge by a downstream sensor. Precise determinations of the distance between the break-off point and the detection downstream permits accurate droplet flight time measurement to allow ink composition and spacing to be controlled.

Abstract: Flight time of a stream of ink drops is measured and compared against a set point to determine variations therefrom. Variations due to changes in the ink composition are compensated for by adding or withholding solvent in proportion to the detected change. Changes due to variations in nozzle drive voltage result in the computation and use of a new flight time set point value, if necessary to avoid erroneous corrective action.

Abstract: A method and system for temporarily halting an article for sensing with a fixed sensing system without altering its average speed. While halted, the article's orientation is manipulated for seeking and presenting a specific area thereon for sensing. The time available for manipulation results from accelerating each article relative to the average speed of articles prior to sensing. The sensing of the article includes visually reading a label thereon to identify the article, and inspection of the article for determining its physical condition. If desired, the physical condition of the article such as a glass bottle may also be evaluated without halting movement thereof. Once the article has been identified and inspected, the article is categorized based on the visual information obtained. Articles in certain categories are rejected from those evaluated.

Abstract: A laser marker system for marking indicia onto a substrate includes an exit lens having a focal length and a single laser source. The surface of the substrate to be marked is positioned generally at the focal plane of the lens. The single laser source is arranged so that its energy output beams are oriented in a generally parallel relationship. The single laser source includes segmented reflecting means for generating a plurality of output energy beams to create a column of spots on the substrate with a higher resolution. The segmented reflecting means is comprised of a back-reflecting mirror which is formed of a plurality of different mirror segments. A device is provided for moving each of the plurality of different mirror segments between a lasing position and a non-lasing position to vary the number of output energy beams and thus the number of spots on the substrate.