Method for calibrating an apparatus for manufacturing a three-dimensional object

A method for calibrating an apparatus for manufacturing a three-dimensional object by layer-wise solidification of building material at positions corresponding to a cross-section of the object to be manufactured in a respective layer, in which method an irradiation pattern is detected in a spatially resolved manner, wherein the apparatus comprises a build space, in which a build area is provided and in which the object is to be built by selectively solidifying the building material, a solidification device for emitting at least one beam of electromagnetic radiation or at least one particle beam to selective positions of the build area, and a detection device with at least one radiation sensor, the method comprising:

• generating an irradiation pattern on the build area in a layer of the building material or on a target;
• conducting an electromagnetic radiation that is emitted from the building material or the target when generating the irradiation pattern to the radiation sensor;
• detecting the radiation by the radiation sensor;
• and
• deriving calibration information on the basis of the step of detecting.

An apparatus for manufacturing a three-dimensional object by layer-wise solidification of a building material at positions corresponding to a cross-section of the object to be manufactured in a respective layer with a build space, in which a build area is provided and in which the object is to be built in a layer-wise manner by selectively solidifying the building material, wherein the build area comprises at least a first sub-area and a second sub-area that overlap in an overlap zone, and a solidification device for emitting beams of electromagnetic radiation or particle beams to selective positions of the build area, the apparatus comprising:

• a generation unit that generates a substantially periodic first modulation pattern in a layer of the building material or on a target in the first sub-area of the build area during operation;
• a generation unit that generates a substantially periodic second modulation pattern in a layer of the building material or on a target in the second sub-area of the build area during operation, wherein in the overlap zone, the first modulation pattern and the second modulation pattern form a substantially periodic superposition pattern, whose period is larger than a period of the first modulation pattern and a period of the second modulation pattern;
• a detection device that is configured to detect the superposition pattern;
• and
• a determination unit that, during operation, determines a deviation of the position of the superposition pattern on the build area from a reference position.

A calibration unit for calibrating an apparatus for manufacturing a three-dimensional object by layer-wise solidification of a building material at the positions corresponding to a cross-section of the object to be manufactured in a respective layer, wherein the calibration unit detects an irradiation pattern in a spatially resolved manner, wherein the apparatus comprises a build space, in which a build area is provided and in which the object is to be built layer by layer by selectively solidifying the building material, and a solidification device for emitting at least one beam of electromagnetic radiation or at least one particle beam to selective positions of the build area, the calibration unit comprising:

• a generation unit that, during operation, generates the irradiation pattern on the build area in a layer of the building material or on the target;
• a detection device with at least one radiation conductor and at least one radiation sensor, wherein the at least one radiation conductor is configured to conduct radiation to a radiation sensor and wherein the radiation sensor is configured to detect an electromagnetic radiation that is emitted from the building material or from a target when generating the irradiation pattern;
• a coupling-in unit for coupling the electromagnetic radiation emitted from the building material or from a target when generating the irradiation pattern into the radiation conductor;
• and
• a deriving unit for deriving calibration information on the basis of the electromagnetic radiation emitted from the building material or from the target when generating the irradiation pattern detected by the radiation sensor.