Device and method for processing light-polymerizable material for building up an object in layers

A device for processsing light-polymerizable material (5;

• 55;
• 105) for building up an object (27) in layers, using lithography-based generative fabrication, comprising
• a vat (4;
• 64;
• 104) with an at least partially transparently or translucently formed horizontal bottom (6;
• 56;
• 106), into which light-polymerizable material (5;
• 55;
• 105) can be filled,
• a horizontal build platform (12;
• 62) which is held at a settable height above the vat bottom (6;
• 56;
• 106),
• an exposure unit (10;
• 60), which can be controlled for position selective exposure of a surface on the build platform (12;
• 62) with an intensity pattern with predetermined geometry, and
• a control unit (11;
• 61), which is arranged for polymerizing in successive exposure steps layers (28) lying one above the other on the build platform (12;
• 62), respectively with predetermined geometry, by controlling the exposure unit (10;
• 60) and for adjusting, after each exposure step for a layer (28), the relative position of the build platform (12;
• 62) to the vat bottom (6;
• 56;
• 106), in order to build up the object (27) successively in a desired form, which results from a sequence of the layer geometries,
• wherein the vat (4;
• 54;
• 104) is horizontally movable with respect to the exposure unit (10;
• 60) and the build platform (12;
• 62) and a feed device (8;
• 58;
• 108) is provided and, under the control of the control unit (11;
• 61), discharges light-polymerizable material (5;
• 55;
• 105) into the at least one vat (4;
• 54;
• 104), the exposure unit (10;
• 60) and the build platform (12;
• 62) being arranged horizontally at a distance from the feed device (8;
• 58;
• 108), and the control unit is arranged for moving the vat (4;
• 54;
• 104) between successive exposure steps in a prescribed way in a horizontal plane by a drive (28), in order to bring light-polymerizable material (5;
• 55;
• 105) that has been discharged by the feed device (8;
• 58;
• 108) onto the vat bottom into the region between the exposure unit (10;
• 60) and the build platform (12;
• 62),
• wherein the exposure unit (10;
• 60) is arranged below the vat bottom (6;
• 56;
• 106) for exposure of the at least partially transparent vat bottom (6) from below and in that the build platform (12;
• 62) is held on a lifting mechanism (14;
• 64;
• 114) above the vat bottom (6;
• 56;
• 106) in a manner in which the build platform (12;
• 62) can be adjusted in height by the control unit (11;
• 61), in that the control unit is arranged for setting the thickness (21) of the layer (28), to be specific the distance between the build platform (12;
• 62) or the layer last formed and the vat bottom (6;
• 56;
• 106), by means of the lifting mechanism (14;
• 64;
• 114), in that after renewed feeding of light-polymerizable material, the control unit lowers the build platform (12;
• 62) with the layers formed on the build platform, if any are present, again into the newly fed light-polymerizable material (5;
• 55;
• 105), so that light-polymerizable material is displaced from the remaining intermediate space with respect to the vat bottom (6;
• 56;
• 106), and the control unit sets the remaining distance between the lowered lower surface and the vat bottom in a prescribed manner under the control of the control unit (11;
• 61).