Abstract: A printer (106) for building a three-dimensional model by sequential deposition of a plurality of cross-sectional layers by using a thermal print head (1) movable relative to a material bed (102) over a deposited layer. A protective sheet (3) is disposed between the thermal head (1) and deposited layer. Temperature control of the material bed (102) to prevent warping of the model is provided by an independently heatable cover (52, 58) in contact with the surface of the material bed (102) e.g. via the protective sheet (3).

Abstract: A three-dimensional printer (100) having a means for cooling (124) the uppermost surface of a material bed in a region immediately before a deposited layer of material (e.g. powder) at the uppermost surface is separated from a protective sheet (116). The protective sheet (116) provides a physical barrier between the deposited layer of material and a thermal print head (114) during printing. The separation of the protective sheet from the material bed may occur to create a distribution gap for a new layer of powder to be deposited (118). The cooling means may facilitate separation of the protective sheet from the deposited layer, and especially from the portion of that layer that has been heat-treated in the preceding printing pass. The cooling means may be an actively cooled surface on a separator that formed part of the print head.

Abstract: A printer head for a thermal printer for building a three-dimensional model by sequential deposition of a plurality of cross-sectional layers, the thermal print head being movable relative to a material bed over a deposited layer. A protective sheet might be disposed between the thermal print head and deposited layer in a thermal printer according to the invention. Temperature control of the material bed to prevent warping of the model is provided by an independently heatable cover in contact with the surface of the material bed. The thermal print head further comprises a cooling element.

Abstract: A powder feed mechanism for a three-dimensional printer in which a heap of powder is drawn up from a powder container to be spread across a material bed rather than dropped or deposited on it. The mechanism comprises a carrier arm that moves through a powder chamber, and a support platform for carrying a heap of powdered build material. The support platform moves with the carrier arm. The carrier arm moves to a powder delivery position in which the support platform is in a transverse orientation for lying flush with the material bed. This arrangement can reduce the path travelled by the powder from the powder chamber to the material bed and give greater control over the shape of the heap of powder that is to be spread over the material bed.

Abstract: A printer (106) for building a three-dimensional model by sequential deposition of a plurality of cross-sectional layers by using a thermal print head (1) movable relative to a material bed (102) over a deposited layer. A protective sheet (3) is disposed between the thermal head (1) and deposited layer. Temperature control of the material bed (102) to prevent warping of the model is provided by an independently heatable cover (52, 58) in contact with the surface of the material bed (102) e.g. via the protective sheet (3).