Optical unit and system for producing a three-dimensional workpiece

1 . An apparatus for producing a three-dimensional workpiece by means of a beam melting process, the apparatus comprising an optical unit and a further optical unit of identical construction, wherein the optical unit comprises:

a beam optics for generating a laser beam and directing the laser beam to a predetermined location, the beam optics comprising a scanning unit for two-dimensionally scanning the laser beam over a top layer of raw material, and

a housing having a housing bottom and an opening provided in the housing bottom which is transparent to the laser beam so that the laser beam can pass through the opening,

wherein the optical unit comprises a lower section comprising the housing bottom and having two side walls each extending parallel to a first direction, and an upper section connected to the lower section and having two side walls each extending parallel to the first direction, the lower section and the upper section being arranged offset from each other such that a first side wall of the side walls of the lower section does not extend in the same plane as a first side wall of the side walls of the upper section and a second side wall of the side walls of the lower section does not extend in the same plane as a second side wall of the side walls of the upper section,

wherein the further optical unit of identical construction is placed adjacent to the optical unit, such that the second side wall of the lower section of the optical unit is arranged adjacent to a first side wall of a lower section of the further optical unit and the second side wall of the upper section of the optical unit is arranged adjacent to a first side wall of an upper section of the further optical unit,

wherein a first connecting surface connects the first side wall of the lower section to the first side wall of the upper section and a second connecting surface connects the second side wall of the lower section to the second side wall of the upper section,

wherein each of the first connecting surface and the second connecting surface is inclined relative to the side walls of the lower section and the side walls of the upper section.

2 . The apparatus according to claim 1 , wherein the side walls of the lower section are parallel to each other and the side walls of the upper section are parallel to each other.

3 . The apparatus according to claim 1 , the optical unit further comprising:

at least one roller provided on the housing bottom, by means of which the optical unit can be rolled along at least the first direction, the first direction corresponding to a rolling direction.

4 . The apparatus according to claim 3 , wherein the optical unit comprises at least three rollers provided on the housing bottom, all of which are offset from each other along a direction perpendicular to the rolling direction.

5 . The apparatus according to claim 3 , wherein the housing bottom comprises at least one hole adapted to receive a fastener.

6 . An apparatus for producing a three-dimensional workpiece by means of a beam melting process, comprising:

a carrier for receiving a plurality of layers of a raw material,

a receiving portion arranged above the carrier and having at least one groove provided in the receiving portion, and

the apparatus according to claim 3 , wherein the at least one roller of the optical unit and the at least one groove of the receiving portion are configured such that the at least one roller can roll along and is guided by the at least one groove.

7 . The apparatus according to claim 6 , wherein an associated groove is provided in the receiving portion for each of the rollers of the optical unit.

8 . The apparatus according to claim 6 , wherein the at least one groove has a recess at an end portion of the groove for receiving an associated roller of the optical unit, the recess being provided with respect to a bottom surface of the groove.

9 . The apparatus according to claim 8 , wherein the recess is configured such that the associated roller does not contact a bottom of the recess when the associated roller is received by the recess and the optical unit is in an end position.

10 . The apparatus according to claim 8 , wherein an inclined transition surface is provided between the bottom surface of the groove and the recess.

11 . The apparatus according to claim 6 , wherein the housing bottom comprises at least one hole, and further comprising at least one fastener adapted to be inserted into the at least one hole of the housing bottom of the optical unit, so as to fasten the optical unit to the receiving portion of the apparatus.

12 . The apparatus according to claim 6 , wherein the receiving portion comprises an opening transparent to the laser beam and adapted to at least partially overlap with an opening of the optical unit in an end position of the optical unit so that the laser beam can be directed through the opening of the optical unit and through an opening of the receiving portion.

13 . The apparatus according to claim 12 , wherein a seal extending around the opening of the receiving portion and/or around the opening of the optical unit is provided.

14 . The apparatus according to claim 1 , wherein the apparatus comprises a plurality of the optical unit, which are arranged side by side.