Abstract: The ink is formed by a solution of a direct dye in a mixture of water and glycol wetting agents, to which a pigment which is finely ground to particles of dimensions of not more than 1000 .ANG. is added in dispersion, in a concentration of between 0.1 and 2%. The pigment particles serve to anchor the gaseous nuclei of gases which are dissolved in the ink for the purpose of stabilizing the boiling point of the ink. The ink is particularly suited to an ink jet printer of the type in which expulsion of the droplets is produced by causing instantaneous vaporization of a portion of ink in a nozzle.

Abstract: The inked element which is preferably in ribbon form comprises a flexible plastics carrier of a thickness of from 5 to 15.mu., covered with a thermotransferable coating which is 2 to 6.mu. in thickeness. The mixture of the coating comprises a blend of thermoplastic resins of non-polymeric type with natural or synthetic waxes with a melting point of between 60.degree. and 80.degree. C. The waxes and the resins are so selected as to be compatible with each other and to provide a melting point of between 60.degree. and 80.degree. C. and a melt viscosity of between 50 to 1000 cps. The ribbon makes it possible to print at a printing rate of 40 to 120 characters/sec on papers having a Bendtsen roughness of 10 to 100 ml/min. The ribbon can be prepared with bands of different colors for multi-color printing.

Abstract: A trichromatic photosensor scans an image to be reproduced repeatedly to generate, for each elementary area scanned, signals indicative of the chromatic characteristics of this elementary area. The photosensor is connected to a trichromatic printer controlled by the signals produced by the photosensor for printing corresponding colored dots on the paper. During successive scanning operations, the photosensor is moved relative to the color image and the printer is moved relative to the paper. These relative movements are coordinated with each other so that the photosensor and the printer act simultaneously on corresponding regions of the color image and of the paper. In one embodiment the printer is stationary and is capable of printing in parallel the dots of one line. The paper circulates along a closed path to be sequentially printed according to the various color components. In another embodiment the printer is of the serial type.

Abstract: The device comprises a plurality of ink reservoirs, each connected to a number of nozzles (22) equidistant along a corresponding row. The nozzles connected to the various reservoirs are spaced apart vertically by at least one line space. The device can be used for printing different lines in parallel, moreover subdividing the length of the line, or for printing different zones of the sheet in facsimile. The ink is kept in circulation between the reservoirs and the nozzles by a common peristaltic pump which acts by a series of actuating elements on the discharge ducts for the inks in the reservoirs. The reservoirs may contain inks of different colors to permit printing in different colors or polychrome facsimile printing by additive or subtractive synthesis of the colors. The ink is conductive and is kept at earth potential, while electrodes (23) disposed outside the corresponding nozzles (22) are energized selectively to produce sprays of particles of ink from the nozzles.

Abstract: The inked element in the form of a ribbon comprises a plastics support coated on one side with a thin layer (2 to 4 mm) of thermotransferable inking mixture which comprises, in addition to a pigment or dye, a binder of thermoplastic resin, in particular a styrene or terpene resin, a plasticizer and a softening compound constituted by one or more waxes in a percentage between 18 and 50%. The plasticizer is constituted by an ester of phthalic or phosphoric acid or another polymer.

Abstract: The electrophotographic recording element comprises a charge generator compound formed from aniline sulphonephthelein derivatives, in which at least one phenyl ring comprises an amino group substituted by an aromatic or heterocyclic group. The recording element may consist of an electrically conducting support on which a layer is deposited containing the charge generator compound dispersed in a resin, then covered in its turn by a further electric charge transporter layer containing an oxadiazole derivative in solid solution in a resin. The recording element has high sensitivity to luminous radiation over a range extending from visible radiation to infrared, and can consequently be used in normal copying machines and especially in laser printers operating with a wavelength up to about 850 nm.

Abstract: A device for non impact printing of alpha-numeric characters on a sheet of normal paper, wherein an electrically conducting carrier is covered with an inking substance which is transferred to the paper by means of electrical pulses.The inked carrier is movable and is disposed against the paper on the opposite side to a print head provided with a plurality of electrodes and movable with a translatory motion with respect to the paper. The inked carrier passes through an inking station in which a series of rollers take ink from a container and, with a metered action, spread it on the carrier, thus renewing the efficiency of the layer of ink.

Abstract: The printer comprises electrodes arrayed in circumferential rings and rows parallel to the axis of a cylinder. This axis corresponds to the vertical direction of characters printed on a sheet of paper. The print cylinder is moved in the direction of a line of print transversely to the direction of feed movement of the paper and rotates with respect to the paper in order to avoid sliding movement. A movable inked ribbon is disposed against the top face of the paper on which the printing is to be effected, and on the opposite side to the print cylinder. The inked ribbon is electrically conducting and connected to one terminal of the power supply which selectively energizes the electrodes. The ribbon is moved in the same direction as the print cylinder by means of drive rollers. The inked ribbon passes through an inking station for continuously renewing the layer of ink.

Abstract: An electrothermic printing unit for writing dot matrix characters on a printing line of a recording medium by means of an electrothermal printing head which is continuously movable along the printing line during the printing operation and having a column of resistive printing elements therein disposed transverse to the printing line and selectively electrically heatable in timed relation with the movement of the head characterized in that a thermosensitive inking element having a support of heat permeable material covered by a coating of material transferable for the combined action of head and pressure is interposed between the head and the recording medium, pressure means being provided for pressing said printing elements against said support and said coating against said recording medium during the movement of the head.

Abstract: A thermosensitive record medium comprising a base sheet coated with a thermosensitive mixture resulting by mixing together a crystal violet lactone and a phenolic compound in a binding and dispersing agent comprising at least 5% of nonionic cellulose ether. The use of this binder improves the stability of the mixture avoiding any unusual color reaction.

Abstract: A temperature-responsive record material for use in a thermographic recording and reproducing apparatus comprising a supporting sheet carrying a single layer containing, as the temperature-sensitive composition, a mixture resulting by a dispersion of a basic chromogenic compound and of an acidic compound in a binder having as assential binding agent a latex or a mixture of a latex with a non-ionic cellulose ether.

Abstract: This invention involves an imaging process in which a light image is projected onto a photosensitive medium having a layer capable upon light exposure of directly generating nuclei of a metal more noble than silver, such as palladium, which metal is catalytic to the electroless deposition of a non-noble metal, and thereafter selectively providing non-noble free metal onto the noble metal nuclei by electroless deposition, thereby providing a visible print of the original light image. The photosensitive layer in such media may comprise a compound of a metal more noble than silver and a photosensitive composition which can generate upon light exposure a reducing agent for said noble metal. In another embodiment, the photosensitive layer may contain a photoreducible metal salt which, upon light exposure, generates nuclei of a metal more noble than silver.