Abstract: According to an example, a 3D printer may include a delivery device and a controller. The controller may access a morphology of a part to be formed from a plurality of build materials in a layer, determine, based upon the accessed morphology, a first delivery pattern for the delivery device to selectively deliver liquid droplets onto build materials in the layer during a first pass over the layer and a second delivery pattern for the delivery device to selectively deliver liquid droplets onto build materials in the layer during a second pass over the layer to control a property of the part formed of some of the build materials in the layer. The controller may also control the delivery device to selectively deliver liquid droplets onto build materials in the layer according to the determined first and second delivery patterns respectively during the first pass and the second pass.

Abstract: Disclosed are methods and apparatus for hermetically sealing a nonlinear optical (NLO) crystal for use in a laser system. A mounted NLO crystal, an enclosure base, a lid, and a plurality of window components are moved into an oven. A vacuum bake process is then performed on the mounted NLO crystal, enclosure base, lid, and plurality of window components until a humidity level that is less than a predefined amount is reached. The mounted NLO crystal, enclosure base, lid, and plurality of window components are moved from the oven onto a stage of a glove box that includes a sealing tool. In the glove box, the mounted NLO crystal is hermetically sealed into the enclosure base by sealing the lid and plurality of window components into openings of the enclosure base.

Abstract: In an example, a method of controlling an additive manufacturing apparatus to generate a three dimensional object comprises processing successive layers of build material so as to form successive layers of a three dimensional object, wherein the processing of each layer is performed within a predetermined layer processing time by a plurality of components. The method may further include selecting, by at least one processor, from a plurality of ancillary tasks, at least one ancillary task to be performed in relation to at least one component of the plurality of components. The method may further include scheduling, by at least one processor, the at least one ancillary task to be performed in relation to the at least one component within the predetermined layer processing time for a single layer or for multiple layers of the build material.

Abstract: A lithographic apparatus injects gas between a patterning device and a patterning device masking blade to help protect the patterning device from contamination. The gas may be injected into the space defined between the patterning device and the patterning device blade by one or more gas supply nozzles that are arranged on at least one side of the patterning device. The one or more gas supply nozzles are coupled to a frame which a patterning device support structure moves relative to. Each nozzle may be constructed and arranged to supply gas over at least the patterning region of the reflective patterning device.

Abstract: In some examples, an agent distributor may be to selectively deliver agent through nozzles of the agent distributor to portions of layers of build material in patterns derived from agent delivery control data representing slices of a three-dimensional object such that the portions are to solidify to form the slices in accordance with the patterns. While generating the three-dimensional object, the agent distributor may be primed such that a particle of the build material is removed from the agent distributor through at least one of the nozzles.

Abstract: There is disclosed additive manufacturing apparatus comprising: a controller (110) to: receive object data relating to an object to be generated; and define print data for additive manufacture of the object by ejection of a print agent on build material in a pattern corresponding to selective fusing of the build material, wherein the print data is defined based on the object data so that the pattern defines a shield feature (56) embedded within the object to inhibit fusing of build material corresponding to the shield feature relative build material corresponding to an adjacent portion of the object; and a print agent distributor (104) to eject a print agent on build material based on the print data.

Abstract: Examples include apparatuses, processes, and methods for generating three-dimensional objects. An example apparatus comprises build material distributor and a controller. Examples distribute a particular build layer in a build area of the apparatus over a previous build layer. Examples determine a build layer temperature corresponding to the particular build layer. Examples analyze build layer coverage for the particular build layer based at least in part on a build layer temperature of the previous build layer and the build layer temperature of the particular build layer. Examples selectively recoat the particular build layer with additional build material based at least in part on the build layer coverage for the particular build layer.

Abstract: There is provided a method and apparatus for controlling heat to a build surface. A thermal profile over the build surface is determined. The determined thermal profile over the build surface is compared with an expected thermal profile over the build surface. Based on the comparison, the determined thermal profile over the build surface or the expected thermal profile over the build surface is selected to control an amount of heat provided by a heating module to the build surface.

Abstract: A technique for classifying lesions as malignant or benign is disclosed. The technique can include: cooling an area of skin including a lesion of a patient to initiate a warm-up process; receiving a temporal sequence of thermal images of the area of skin representing a thermal recovery of the area of skin, the temporal sequence of thermal images generated by an infrared camera; generating a temporal profile of the thermal recovery based on the temporal sequence of thermal images; analyzing temporal statistical properties of the temporal profile; determining a malignancy probability that the lesion is malignant based on an analysis of the temporal profile, wherein the determining includes extracting one or more statistical features based on continuous-time stochastic signals in the sequence of thermal images; and classifying the lesion based on the malignancy probability.

Abstract: Temperatures of a layer of build material on a support member may be detected. Each of the temperatures corresponding to a respective area of the layer. Based on data representing the three-dimensional object, a subset of the temperatures may be filtered from spatial temperature distribution data comprising the temperatures. A degree of heat or energy applied to the layer may be controlled based on the filtered spatial temperature distribution data.

Abstract: According to one example, there is provided a method of 3D printing. The method comprises generating, within a volume of build material, a volume of solidified build material, and marking a predetermined portion of unsolidified build material within the build volume with a marking agent.

Abstract: There is provided a method of generating print data for use by an additive manufacturing system to generate a plurality of 3D objects within a build chamber having a build surface. First spatial data defining a first 3D object and second spatial data defining a second 3D object is received. First print data is generated to cause the additive manufacturing system to manufacture the first 3D object at least partly from a first build material. Intermediate print data is generated to cause the additive manufacturing system to manufacture a partition comprising a 3D object configured to fill the build chamber in a plane parallel to the build surface. Second print data is generated to cause the additive manufacturing system to manufacture the second 3D object at least partly from a second build material.

Abstract: Apparatus to produce a three-dimensional object and methods of producing a three-dimensional object are described. In some examples, a first fluid comprising a colorant and a second fluid comprising an absorber to absorb electromagnetic radiation are applied on a layer of particulate material. Application of the second fluid to the layer of particulate material is in dependence on an ability of the first fluid to absorb the electromagnetic radiation.

Abstract: In some examples, an agent distributor may be to selectively deliver agent through nozzles of the agent distributor to portions of layers of build material in patterns derived from agent delivery control data representing slices of a three-dimensional object such that the portions are to solidify to form the slices in accordance with the patterns. While generating the three-dimensional object, the agent distributor may be primed such that a particle of the build material is removed from the agent distributor through at least one of the nozzles.

Abstract: A method for determining a parameter of a process associated with a 3D printing process provided. A first amount corresponding to an object of fused powder surrounded by non-fused powder is used. The first amount is separated into a second amount of non-fused powder and a third amount corresponding to the object including residual powder material attached. The residual powder material is removed from the object using a fourth amount of a cleaning agent. A fifth amount corresponding to the fused powder of the cleaned object and a sixth amount of material corresponding to a mixture of the removed residual powder material and the cleaning agent is obtained. The mixture includes a seventh amount of material being recovered, an eighth amount of material corresponding to powder material wastage, and the fourth amount. The parameter is derived from at least two of first to eighth amounts of material.

Abstract: According to one example, there is provided a method of determining characteristics of a build material. The method comprises obtaining a first quantity of a first build material, determining, for the first build material, the proportion of non-marked build material and marked build material, determining, based on the determined proportion, a first quantity of the first build material to be combined with a second quantity of a second build material to produce a third quantity of mixed build material having a predetermined proportion of marked build material.

Abstract: A method of fabricating a three dimensional object in an additive layer manufacturing process, e.g. 3D printing, wherein a three dimensional design of the three dimensional object is modelled as a plurality of three dimensional pixels or vortexes. For every pixel or vortex, at least one parameter is calculated and is used to select a setting for use when fabricating the three dimensional object. The parameter may be a speed or rate at which heat will diffuse away from the pixel or vortex, or a weighted density surrounding the pixel or vortex. The method provides higher quality fabrication of the three dimensional object.

Abstract: A method of calibrating an apparatus for generating a three-dimensional object is described in which a calibration substrate is generated by depositing build material and applying energy to the build material to form a fused surface; a calibration pattern is generated on the calibration substrate by depositing an agent on the calibration surface according to a predetermined pattern; and an attribute of the calibration pattern is measured.

Abstract: A lithographic apparatus injects gas between a patterning device and a patterning device masking blade to help protect the patterning device from contamination. The gas may be injected into the space defined between the patterning device and the patterning device blade by one or more gas supply nozzles that are arranged on at least one side of the patterning device. The one or more gas supply nozzles are coupled to a frame which a patterning device support structure moves relative to. Each nozzle may be constructed and arranged to supply gas over at least the patterning region of the reflective patterning device.

Abstract: A method of controlling temperature in an apparatus for generating a three-dimensional object comprises performing a calibration test on a sample of build material that is to be used in generating a three-dimensional object, calibrating at least one temperature point from the calibration test, and using the at least one calibrated temperature point during subsequent temperature control of the apparatus.