A continuous inkjet printer has an ink circuit comprising an ink tank, an ink pump and a Venture suction device. The Venturi is used to suck an extra solvent or ink as required. However, if the ink tank is empty, no ink can be pumped through the Venture and so it will not develop suction and thus, cannot be used to suck in an initial supply of ink to an empty tank. A removable ink container may be connected to the ink tank or elsewhere in the ink circuit, for example, between the Venturi outlet and the pump inlet. Compressing the ink container manually will force ink into the ink circuit. When enough ink has been added, the pump will drive ink through the Venturi and suction will be generated.

A print head of a continuous ink jet printer comprising: a cavity for the circulation of jets, delimited laterally by a 1.sup.st side wall and a 2.sup.nd side wall, both at least partially parallel to a direction of flow of the jets in the cavity, at least one nozzle for producing at least one ink jet in the cavity, at least one electrode for sorting drops or segments of one or several of the jets intended for printing from drops or segments that are not used for printing; an outlet slot, open onto the exterior of the cavity and allowing the exiting of the drops or segment of ink intended for printing, at least one gutter for recovering drops or segments not intended for printing, at least one spraying nozzle, arranged in the cavity, for projecting at least one cleaning fluid towards at least one inner portion of the cavity and a motor driving the at least one spraying nozzle in rotation about an axis (x), for example perpendicular to a direction of flow of the jets in the cavity; a supply circuit supplying at least the spraying nozzle with cleaning fluid.

A print head of a continuous ink jet printer comprising: a cavity for the circulation of jets, delimited laterally by a 1.sup.st side wall and a 2.sup.nd side wall, both at least partially parallel to a direction of flow of the jets in the cavity, at least one nozzle for producing at least one ink jet in the cavity, at least one electrode for sorting drops or segments of one or several of the jets intended for printing from drops or segments that are not used for printing; an outlet slot, open onto the exterior of the cavity and allowing the exiting of the drops or segment of ink intended for printing, at least one gutter for recovering drops or segments not intended for printing, at least one spraying nozzle, arranged in the cavity, for projecting at least one cleaning fluid towards at least one inner portion of the cavity and a motor driving the at least one spraying nozzle in rotation about an axis (x), for example perpendicular to a direction of flow of the jets in the cavity; a supply circuit supplying at least the spraying nozzle with cleaning fluid.

An aqueous colored pigment-based ink that is capable of fluorescence, has a pigment colorant in an amount of 1-7 weight %; a non-polymeric fluorophore that when excited by fluorescence-exciting radiation having a peak of at least 200 nm and up to and including 400 nm, exhibits an emission peak of at least 400 nm and up to and including 750 nm, and which non-polymeric fluorophore is present in an amount of 0.1-2 weight %; and an aqueous medium comprising water. This aqueous colored pigment-based ink can be included in an ink set that also includes one or more aqueous colored pigment-based inks that are non-fluorescent. All of these inks can be applied using continuous inkjet (CIJ) printing, onto non-UV fluorescent substrates to provide images that can be detected when excited as noted above, which images can be provided on articles such as security documents, currency, and lottery tickets.

An aqueous colored pigment-based ink that is capable of fluorescence, has a pigment colorant in an amount of 1-7 weight %; a non-polymeric fluorophore that when excited by fluorescence-exciting radiation having a peak of at least 200 nm and up to and including 400 nm, exhibits an emission peak of at least 400 nm and up to and including 750 nm, and which non-polymeric fluorophore is present in an amount of 0.1-2 weight %; and an aqueous medium comprising water. This aqueous colored pigment-based ink can be included in an ink set that also includes one or more aqueous colored pigment-based inks that are non-fluorescent. All of these inks can be applied using continuous inkjet (CIJ) printing, onto non-UV fluorescent substrates to provide images that can be detected when excited as noted above, which images can be provided on articles such as security documents, currency, and lottery tickets.

Apparatus for continuous ink jet printing, comprising: an ink system comprising an ink storage tank (15) operable to supply ink to a print head associated with the apparatus; a single cartridge connection (9) for releasable engagement with a fluid cartridge (8), the cartridge connection (9) comprising: a fluid connector (10) for engaging an outlet of a fluid cartridge; and a conduit configured to allow fluid to flow along a fluid pathway from a cartridge engaged with the cartridge connection, via the fluid connector, to the ink storage tank. The apparatus has a first configuration in which a solvent cartridge is engaged with the cartridge connection and in which the apparatus is configured to receive solvent from the engaged solvent cartridge, and a second configuration in which an ink cartridge is engaged with the cartridge connection and in which the apparatus is configured to receive ink from the engaged ink cartridge.

Apparatus for continuous ink jet printing, comprising: an ink system comprising an ink storage tank (15) operable to supply ink to a print head associated with the apparatus; a single cartridge connection (9) for releasable engagement with a fluid cartridge (8), the cartridge connection (9) comprising: a fluid connector (10) for engaging an outlet of a fluid cartridge; and a conduit configured to allow fluid to flow along a fluid pathway from a cartridge engaged with the cartridge connection, via the fluid connector, to the ink storage tank. The apparatus has a first configuration in which a solvent cartridge is engaged with the cartridge connection and in which the apparatus is configured to receive solvent from the engaged solvent cartridge, and a second configuration in which an ink cartridge is engaged with the cartridge connection and in which the apparatus is configured to receive ink from the engaged ink cartridge.

The system and methods for marking an optical fiber with color-coded marks disclosed herein include forming closely spaced multiple ink streams, with at least two of the ink streams having different colors. The optical fiber moves over a fiber path that resides adjacent the ink streams. The fiber path and the ink streams are made to briefly intersect so that the ink streams form on the outer surface of the optical fiber a group of spaced apart individual marks, wherein the group of individual marks constitute a color-coded mark. Repeating this marking process at different times as the fiber moves over the fiber path forms spaced apart color-coded marks along the length of the fiber. Subsequent drying and overcoating of the marks fixes and protects the color-coded marks.

The system and methods for marking an optical fiber with color-coded marks disclosed herein include forming closely spaced multiple ink streams, with at least two of the ink streams having different colors. The optical fiber moves over a fiber path that resides adjacent the ink streams. The fiber path and the ink streams are made to briefly intersect so that the ink streams form on the outer surface of the optical fiber a group of spaced apart individual marks, wherein the group of individual marks constitute a color-coded mark. Repeating this marking process at different times as the fiber moves over the fiber path forms spaced apart color-coded marks along the length of the fiber. Subsequent drying and overcoating of the marks fixes and protects the color-coded marks.

In a method of supplying chemical liquid using an ink jet head including a central portion and peripheral portions each having a first portion and a second portion, a first chemical liquid supply of a chemical liquid may be provided from the central portion onto a substrate, a second chemical liquid supply of the chemical liquid may be provided from the first portion onto a substrate, and a third chemical liquid supply of the chemical liquid may be provided from the second portion onto a substrate. The ink jet head may be moved over the substrate by a length of the peripheral portion. The first chemical liquid supply of the chemical liquid may be provided from the central portion onto a substrate, the second chemical liquid supply of the chemical liquid may be provided from the first portion onto a substrate, and the third chemical liquid supply of the chemical liquid may be provided from the second portion onto a substrate.