PRINTER NOZZLE STRUCTURE

A nozzle structure (102, 202) is presented for use in a print head for discharging drops of a printing material onto a substrate located in a printing plane. The nozzle structure (102, 202) comprises a tubular member (104, 204, 4) having a distal part by, which it faces the printing plane when in operation, and defining an elongated inner cavity (114, 14, 214) along the length of the tubular member (104, 204, 4) for placement of a filament of the printing material. The tubular member (104, 204, 4) comprises light input ports (124, 224, 24) on the proximal part thereof configured for directing diverging input light beams towards inner surfaces of the tubular member (104, 204, 4) with a predetermined incidence onto the inner surfaces. The tubular member (104, 204, 4) has an integrally made elongated tube portion (120, 20, 220) and a distal tip portion (115, 15, 215) at the distal part of the tubular member (104, 204, 4), the elongated tube portion (120, 20, 220) of the tubular member (104, 204, 4) being configured and operable as a light guide for trapping the input light from the light input ports (124, 224, 24) at the proximal part and guiding the trapped light propagation along the tubular member (104, 204, 4) in a general propagation direction towards the distal part by reflections from the inner surfaces, thereby continuously transferring increasing amount of light field to successive regions of the elongated inner cavity (114, 14, 214) from the proximal part of the tubular member (104, 204, 4) towards the distal part thereof. The distal tip portion (115, 15, 215) is configured to affect light reflections from the inner surfaces of the tubular member (104, 204, 4) and allow the trapped light to escape towards the printing plane, thereby interacting with and heating a location on the printing plane facing the distal part.