Build system, and build method

Abstract

A build system includes: a build apparatus (1) configured to build a three-dimensional build object by irradiating a material layer with an energy beam; and a control apparatus (2) configured to control the build apparatus. The build apparatus includes: a layer forming apparatus (122) configured to form a material layer; a measurement apparatus (14); and a plate moving apparatus (114) configured to move at least one of at least a part of the layer forming apparatus and the build plate. The control apparatus makes at least one of at least a part of the layer forming apparatus and the moving apparatus operate based on a first measured result acquired by measuring the build plate before the material layer is formed on the build plate and a second measured result acquired by measuring the material layer after the material layer is formed on the build plate.

Description

BUILD SYSTEM, AND BUILD METHOD

[0001] The present invention relates to a technical field of a build system and a build method that build a three-dimensional build object by irradiating a material layer with an energy beam, for example.

[0002] A Patent Literature 1 discloses one example of a build system that builds a three-dimensional build object by irradiating a material layer with an energy beam. The build system is required to properly build the three-dimensional build object.

[0003] Patent Literature 1: US2019 / 0152157A1

[0004] A first aspect provides a build system including: a build apparatus configured to build a three-dimensional build object by irradiating a material layer with an energy beam; and a control apparatus configured to control the build apparatus, wherein the build apparatus includes a layer forming apparatus configured to form a material layer, a measurement apparatus, and a moving apparatus configured to move at least one of at least a part of the layer forming apparatus and the build plate, and the control apparatus: acquires, from the measurement apparatus, a first measured result acquired by measuring the build plate before the material layer is formed on the build plate and a second measured result acquired by measuring the material layer after the material layer is formed on the build plate; and makes at least one of the at least a part of the layer forming apparatus and the moving apparatus operate based on the first and second measured results.

[0005] A second aspect provides a build system including: a build apparatus configured to build a three-dimensional build object by irradiating a material layer with an energy beam; and a control apparatus configured to control the build apparatus, wherein the build apparatus includes a layer forming apparatus configured to form a material layer, a measurement apparatus, and a moving apparatus configured to move at least one of at least a part of the layer forming apparatus and the build plate, and the control apparatus: acquires, from the measurement apparatus, a material layer measured result acquired by the measurement apparatus measuring the material layer after the material layer is formed on the build plate; and makes at least one of the at least a part of the layer forming apparatus and the moving apparatus operate based on the material layer measured result.

[0006] A third aspect provides a build method which builds a three-dimensional build object by irradiating a material layer formed by a layer forming apparatus with an energy beam, the build method includes: acquiring, from a measurement apparatus, a first measured result acquired by measuring a build plate before the material layer is formed on the build plate; acquiring, from the measurement apparatus, a second measured result acquired by measuring the material layer after the material layer is formed on the build plate; and manipulating at least one of at least a part of the layer forming apparatus and a moving apparatus based on the first and second measured results. A fourth aspect provides a build method including: forming a material layer from a raw material; and building a three-dimensional build object by irradiating the material layer with an energy beam, wherein the build method includes: forming a first material layer by supplying a raw material while moving a material supply member relative to a build plate; acquiring a first measured result of the first material layer by measuring the first material layer; forming a second material layer on the first material layer by supplying a raw material while moving the material supply member relative to the build plate after acquiring the first measured result; acquiring a second measured result of the second material layer by measuring the second material layer; and acquiring a difference between the first measured result and the second measured result.

[0007] A fifth aspect provides a build system including: a build apparatus configured to build a three-dimensional build object by irradiating a material layer formed on a build plate with an energy beam; and a control apparatus configured to control the build apparatus, wherein the build apparatus includes a layer forming apparatus configured to form a material layer, a measurement apparatus, and a plate moving apparatus configured to move the build plate, and the control apparatus: controls the layer forming apparatus to form a first material layer by supplying a raw material while moving a material supply member of the layer forming apparatus relative to the build plate; control the measurement apparatus to acquire a first measured result of the first material layer by measuring the first material layer; controls the layer forming apparatus to form a second material layer on the first material layer by supplying a raw material while moving the material supply member relative to the build plate after acquiring the first measured result; controls the measurement apparatus to acquire a second measured result of the second material layer by measuring the second material layer; and acquires a difference between the first measured result and the second measured result.

[0008] A sixth aspect provides a build method that builds the three-dimensional build object by using the build system provided by the first, second or fifth aspect.

[0009] FIG. 1 is a block diagram that illustrates an entire configuration of a build system in a present example embodiment.FIG. 2 is a cross-sectional view that illustrates one example of a configuration of a build apparatus in the present example embodiment.FIG. 3 is a block diagram that illustrates one example of a system configuration of the build apparatus in the present example embodiment.FIG. 4 Each of FIG. 4A to FIG. 4D is a cross-sectional view that illustrates a moving blade.FIG. 5 is a block diagram that illustrates one example of a system configuration of a control apparatus in the present example embodiment.FIG. 6 is a flowchart that illustrates a flow of a build operation performed by the build system.FIG. 7 is a cross-sectional view that illustrates a build plate whose position is adjusted by a rough alignment operation.FIG. 8 is a cross-sectional view that illustrates the build plate whose position is adjusted by the rough alignment operation.FIG. 9 is a cross-sectional view that illustrates the build plate whose position is adjusted by the rough alignment operation.FIG. 10 Each of FIG. 10A to FIG. 10D is a cross-sectional view that illustrates a moving blade.FIG. 11 Each of FIG. 11A and FIG. 11 illustrates a plane fitting a three-dimensional shape of a surface of a material layer.FIG. 12A is a cross-sectional view that illustrates an example in which each of a lower surface of the blade and an upper surface of the material layer is parallel to an upper surface of the build plate, and FIG. 12B is a cross-sectional view that illustrates an example in which each of the lower surface of the blade and the upper surface of the material layer is not parallel to the upper surface of the build plate.FIG. 13A is a cross-sectional view that illustrates the build plate before it is moved so that each of the lower surface of the blade and the upper surface of the material layer is parallel to the upper surface of the build plate, and FIG. 13B is a cross-sectional view that illustrates the build plate that has been already moved so that each of the lower surface of the blade and the upper surface of the material layer is parallel to the upper surface of the build plate.FIG. 14A is a cross-sectional view that illustrates the build plate before it is moved so that each of the lower surface of the blade and the upper surface of the material layer is parallel to the upper surface of the build plate, and FIG. 14A is a cross-sectional view that illustrates the build plate that has been already moved so that each of the lower surface of the blade and the upper surface of the material layer is parallel to the upper surface of the build plate.FIG. 15A is a cross-sectional view that illustrates the blade before it is moved so that each of the lower surface of the blade and the upper surface of the material layer is parallel to the upper surface of the build plate, and FIG. 15B is a cross-sectional view that illustrates the blade that has been already moved so that each of the lower surface of the blade and the upper surface of the material layer is parallel to the upper surface of the build plate.FIG. 16A is a cross-sectional view that illustrates the blade before it is moved so that each of the lower surface of the blade and the upper surface of the material layer is parallel to the upper surface of the build plate, and FIG. 16B is a cross-sectional view that illustrates the blade that has been already moved so that each of the lower surface of the blade and the upper surface of the material layer is parallel to the upper surface of the build plate.FIG. 17 is a planar view that illustrates a projection pattern across the build plate and a build tank.FIG. 18 Each of FIG. 18A and FIG. 18B illustrates an image in which the projection pattern across the build plate and the build tank is captured.FIG. 19 illustrates a position of the build tank estimated by interpolating a measured result of a position of the build plate.FIG. 20 is a flowchart that illustrates a flow of a build operation in a third modified example.FIG. 21 is a flowchart that illustrates a flow of a build operation in a fourth modified example.FIG 22 is a cross-sectional view that illustrates one example of a configuration of a build apparatus in a seventh modified example.Description of Example embodiments

[0010] Next, with reference to drawings, an example embodiment of a build system and a build method will be described. In the below-described description, the example embodiment of the build system and the build method will be described by using a build system SYS to which the example embodiment of the build system and the build method is adapted.

[0011] Moreover, in the below-described description, a positional relationship of various components included in the build system SYS will be described by using an XYZ rectangular coordinate system that is defined by an X-axis, a Y-axis and a Z-axis that are perpendicular to one another. Note that each of an X-axis direction and a Y-axis direction is assumed to be a horizontal direction (namely, a predetermined direction in a horizontal plane) and a Z-axis direction is assumed to be a vertical direction (namely, a direction that is perpendicular to the horizontal plane, and substantially a up-down direction) in the below-described description, for convenience of the description. Moreover, rotational directions (in other words, inclination directions) around the X-axis, the Y-axis and the Z-axis are referred to as a θX direction, a θY direction and a θZ direction, respectively. Here, the Z-axis direction may be a gravity direction. Moreover, an XY plane may be a horizontal plane.

[0012] (1) Configuration of Build System SYS Firstly, a configuration of the build system in a present example embodiment will be described.

[0013] (1-1) Entire Configuration of Build System SYS Firstly, with reference to FIG. 1, an entire configuration of the processing apparatus 1a in the first example embodiment will be described. FIG. 1 is a block diagram that illustrates the entire configuration of the build system SYS in the present example embodiment.

[0014] As illustrated in FIG. 1, the build system SYS includes a build apparatus 1 and a control apparatus 2.

[0015] The build apparatus 1 is configured to build a three-dimensional build object. In the present example embodiment, an example in which the build apparatus 1 builds a three-dimensional build object by performing an additive manufacturing based on a Powder Bed Fusion method (PBF). The Powder Bed Fusion method may be referred to as a Selective Layer Sintering method (SLS).

[0016] The control apparatus 2 is configured to control the build apparatus 1. For example, the control apparatus 2 may control the build apparatus 1 to build the three-dimensional build object.

[0017] The control apparatus 2 may be connected to the build apparatus 1 through a wired and / or wireless network (alternatively, a data bus and / or a communication line). A network using a serial-bus-type interface such as at least one of IEEE1394, RS-232x, RS-422, RS-423, RS-485 and USB may be used as the wired network. A network using a parallel-bus-type interface may be used as the wired network. A network using an interface that is compatible to Ethernet (registered trademark) such as at least one of 10-BASE-T, 100BASE-TX or 1000BASE-T may be used as the wired network. A network using an electrical wave may be used as the wireless network. A network that is compatible to IEEE802.1x (for example, at least one of a wireless LAN and Bluetooth (registered trademark)) is one example of the network using the electrical wave. A network using an infrared ray may be used as the wireless network. A network using an optical communication may be used as the wireless network. In this case, the control apparatus 2 and the build apparatus 1 may be configured to transmit and receive various information through the network. Moreover, the control apparatus 2 may be configured to transmit information such as a command and a control parameter to the build apparatus 1 through the network. The build apparatus 1 may include a receiving apparatus that is configured to receive the information such as the command and the control parameter from the control apparatus 2 through the network. The build apparatus 1 may include a transmission apparatus that is configured to transmit the information such as the command and the control parameter to the control apparatus 2 through the network. The control apparatus 2 may include a receiving apparatus that is configured to receive the information such as the command and the control parameter from the build apparatus 1 through the network.

[0018] In the example illustrated in FIG. 1, the control apparatus 2 is disposed outside the build apparatus 1. Namely, the control apparatus 2 is an apparatus separated from the build apparatus 1. However, the control apparatus 2 may be disposed inside the build apparatus 1. Namely, the build apparatus 1 may include the control apparatus 2. Alternatively, a first control apparatus that is configured to perform a part of an arithmetic processing performed by the control apparatus 2 may be disposed inside the build apparatus 1, and a second control apparatus that is configured to perform another part of the arithmetic processing performed by the control apparatus 2 may be disposed outside the build apparatus 1.

[0019] (1-2) Configuration of Build Apparatus 1 Next, with reference to FIG. 2 and FIG. 3, one example of a configuration of the build apparatus 1 in the present example embodiment will be described. FIG. 2 is a cross-sectional view that illustrates one example of the configuration of the build apparatus 1. FIG. 3 is a block diagram that illustrates one example of a system configuration of the build apparatus 1.

[0020] As described above, the build apparatus 1 performs the additive manufacturing based on the Powder Bed Fusion method. The build apparatus 1 that performs the additive manufacturing based on the Powder Bed Fusion method may build the three-dimensional build object by irradiating a material layer ML with build light BL that is an energy beam. Specifically, the build apparatus 1 may build the three-dimensional build object including a plurality of structural layers SL by alternately repeating an operation for forming the material layer ML and an operation for forming the structural layer SL by irradiating the formed material layer ML with the build light BL.

[0021] In order to build the three-dimensional build object, the build apparatus 1 may include a stage apparatus 11, a layer forming apparatus 12, a beam scanning apparatus 13, and a measurement apparatus 14, as illustrated in FIG. 2 to FIG. 3. The stage apparatus 11 and the layer forming apparatus 12 may be contained in a chamber space 15SP in a chamber 15 of the build apparatus 1.

[0022] The stage apparatus 11 includes a build tank 111, a carrier 112, a build plate 113, a carrier driving system 114, a position measurement apparatus 115, and a heater 116.

[0023] The build tank 111 is a member that is allowed to serve as a container. For example, the build tank 111 is a cylindrical (in other words, cylinder-shaped) member extending along the Z-axis direction. Specifically, the build tank 111 is a cylindrical (in other words, cylinder-shaped) member having at least one side wall 111 along the Z-axis direction. The build tank 111 may be referred to as a build cylinder. Inside the build tank 111 (namely, in a space surrounded by the side wall 111), a carrier 112 that serves as a bottom surface of the build tank 111 is disposed. Furthermore, a build plate 113 is placed on the carrier 112.

[0024] In this case, the build tank 111 (especially, the side wall 1111) may be considered to be a surrounding member that is disposed around the carrier 112 and the build plate 113. The carrier 112 and the build plate 113 may be considered to be surrounded by the build tank 111 (especially, the side wall 1111) that is disposed around the carrier 112 and the build plate 113. In this case, the side wall 1111 of the build tank 111 may be in contact with the carrier 112. The side wall 1111 of the build tank 111 may be in contact with the build plate 113.

[0025] The build plate 113 is a member on which the material layer ML is formed. The build apparatus 1 may perform the operation for forming the material layer ML on the build plate 113, and the operation for forming the structural layer SL on the build plate 113 by irradiating the material layer ML formed on the build plate 113 with the build light BL. The build apparatus 1 may build the three-dimensional build object including the plurality of structural layers SL on the build plate 113 by alternately repeating these two operations.

[0026] However, the carrier 112 may be used as the build plate 113. In this case, the build plate 113 that is different from the carrier 112 may not be placed on the carrier 112.

[0027] The carrier driving system 114 is a carrier moving apparatus that is configured to move the carrier 112 under the control of the control apparatus 2. Therefore, the carrier driving system 114 may include a power source (for example, a motor) that is configured to generating power for moving the carrier 112. When the carrier 112 moves, the build plate 113 on the carrier 112 also moves. Therefore, the carrier driving system 114 may be considered to be a moving apparatus or a plate moving apparatus that is configured to move the build plate 113.

[0028] As described above, the carrier 112 and the build plate 113 are disposed inside the build tank 111. In this case, the carrier driving system 114 may move each of the carrier 112 and the build plate 113 inside the build tank 111.

[0029] The carrier driving system 114 may move the carrier 112 and the build plate 113 along a predetermined translation axis. In this case, the carrier driving system 114 may change (in other words, adjust) positions of the carrier 112 and the build plate 113 along the predetermined translation axis by moving the carrier 112 and the build plate 113 along the predetermined translation axis. For example, the carrier driving system 114 may move the carrier 112 and the build plate 113 along at least one of the translation axis along the X-axis, the translation axis along the Y-axis, and the translation axis along the Z-axis.

[0030] In the present example embodiment, an example in which the carrier driving system 114 is configured to move the carrier 112 and the build plate 113 along the translation axis along the Z-axis will be described. Namely, in the present example embodiment, an example in which the carrier driving system 114 is configured to move the carrier 112 and the build plate 113 along the up-down direction will be described. In other words, in the present example embodiment, an example in which the carrier driving system 114 is configured to move up and down the carrier 112 and the build plate 113 will be described. In this case, the carrier driving system 114 may be considered to be configured to move the carrier 112 and the build plate 113 along the side wall 1111 of the build tank 111, because the side wall 1111 of the build tank 111 extends along the Z-axis direction. In this case, the build tank 111 (especially, the side wall 1111) may serve as a guide member that guides the carrier 112 and the build plate 113 that are movable along the Z-axis direction.

[0031] The carrier driving system 114 may move the carrier 112 and the build plate 113 around a predetermined rotation axis. Namely, the carrier driving system 114 may rotate the carrier 112 and the build plate 113 around the predetermined rotation axis. In this case, the carrier driving system 114 may change (in other words, adjust) attitudes (poses) of the carrier 112 and the build plate 113 around the predetermined rotation axis by moving the carrier 112 and the build plate 113 around the predetermined rotation axis. For example, the carrier driving system 114 may move the carrier 112 and the build plate 113 around at least one of the rotation axis along the X-axis, the rotation axis along the Y-axis, and the rotation axis along the Z-axis. In the present example embodiment, an example in which the carrier driving system 114 is configured to move the carrier 112 around at least one of the rotation axis along the X-axis and the rotation axis along the Y-axis will be described.

[0032] Note that the attitude of the carrier 112 around the predetermined rotation axis may be considered to be equivalent to a position of the carrier 112 in a rotational direction around the predetermined rotation axis. Namely, changing (in other words, adjusting) the attitude of the carrier 112 around the predetermined rotation axis may be considered to be equivalent to changing (in other words, adjusting) the position of the carrier 112 in the rotational direction around the predetermined rotation axis. Moreover, the attitude of the build plate 113 around the predetermined rotation axis may be considered to be equivalent to a position of the build plate 113 in a rotational direction around the predetermined rotation axis. Namely, changing (in other words, adjusting) the attitude of the build plate 113 around the predetermined rotation axis may be considered to be equivalent to changing (in other words, adjusting) the position of the build plate 113 in the rotational direction around the predetermined rotation axis.

[0033] In the example illustrated in FIG. 2, the carrier driving system 114 includes: a plurality of rods 1141 each of which extends along the Z-axis direction and which are connected to different positions of a bottom surface of the carrier 112, respectively; and a non-illustrated power source configured to generating power for moving or extending / retracting each of the plurality of rods 1141 along the Z-axis direction. Here, the rods 1141 may be connected to the carrier 112 at positions that are equally distant in the XY plane from a center of the bottom surface of the carrier 112 in the XY plane, respectively. Moreover, positions at which the rods 1141 are connected to the carrier 112, respectively, may be equally distant from each other in a circumferential direction around an axis that is the center of the bottom surface of the carrier 112. In this case, the carrier driving system 114 may move the carrier 112 and the build plate 113 along the Z-axis direction by moving or extending / retracting the plurality of rods 1141 by the same moving distance along the Z-axis direction. The carrier driving system 114 may move the carrier 112 and the build plate 113 around at least one of the rotation axis along the X-axis and the rotation axis along the Y-axis by moving or extending / retracting at least one of the plurality of rods 1141 along the Z-axis direction without moving or extending / retracting at least other one of the plurality of rods 1141 along the Z-axis direction. The carrier driving system 114 may move the carrier 112 and the build plate 113 around at least one of the rotation axis along the X-axis and the rotation axis along the Y-axis by moving or extending / retracting at least one of the plurality of rods 1141 along the Z-axis direction by a first moving distance and moving or extending / retracting at least other one of the plurality of rods 1141 along the Z-axis direction by a second moving distance different from the first moving distance. Incidentally, the positions at which the rods 1141 are connected to the carrier 112, respectively, may not be equally distant from the center of the carrier 112, and may be unequally distant from each other in the circumferential direction around the axis that is the center of the carrier 112.

[0034] However, a configuration of the carrier driving system 114 is not limited to a configuration illustrated in FIG. 2. For example, the carrier driving system 114 may include: a single rod that extends along the Z-axis direction; and a tilt mechanism that is attached to an end of the rod. The carrier 112 is attached to the tilt mechanism, and the tilt mechanism may move the carrier 112 around a predetermined rotation axis. Moreover, the carrier driving system 114 may move the carrier 112 in the Z-axis direction by moving or extending / retracting the rod to which the carrier 112 is attached through the tilt mechanism in the Z-axis direction.

[0035] The position measurement apparatus 115 is configured to measure a position of at least one of the carrier 112 and the build plate 113. For example, the position measurement apparatus 115 may include an encoder that is configured to measure the position of at least one of the carrier 112 and the build plate 113. In this case, the position measurement apparatus 115 may include encoders that measure moving distances of the rods 1141 of the carrier driving system 114, respectively, and the position of at least one of the carrier 112 and the build plate 113 may be calculated based on measured results of these encoders and the calculated position may be used as the measured result. For example, the position measurement apparatus 115 may include an interferometer that is configured to measure the position of at least one of the carrier 112 and the build plate 113. A measured result of the position of at least one of the carrier 112 and the build plate 113 by the position measurement apparatus 115 may be outputted to the control apparatus 2. Namely, the measured result acquired by the position measurement apparatus 115 (namely, the measured result of the position of at least one of the carrier 112 and the build plate 113) may be outputted to the control apparatus 2.

[0036] The heater 116 is a heating apparatus that is configured to heat the build plate 113 under the control of the control apparatus 2. A temperature regulator such as a Peltier element is one example of heater 116. The heater 116 may heat the build plate 113 so that a temperature of the build plate 113 is a desired temperature. In this case, the build apparatus 1 may include a temperature sensor that is configured to detect the temperature of the build plate 113, and the heater 116 may heat the build plate 113 under the control of the control apparatus 2 until the temperature detected by the temperature sensor is the desired temperature.

[0037] The heater 116 may heat (in other words, preheat) the build plate 113 before the material layer ML is formed on the build plate 113. Especially, the heater 116 may heat (in other words, preheat) the build plate 113 before the first material layer ML is formed on the build plate 113. In this case, compared to a case where the build plate 113 is not preheated, there is a lower possibility that the build plate 113 is thermally expanded after starting to form the build material layer ML on the build plate 113. Such thermal expansion of the build plate 113 results in a deterioration of a build accuracy of the build apparatus 1. Therefore, in a case where the build plate 113 is preheated, there is a lower possibility that the build accuracy of the build apparatus 1 deteriorates, compared to a case where the build plate 113 is not preheated. Namely, the build apparatus 1 can build three-dimensional build object with relatively high build accuracy.

[0038] The layer forming apparatus 12 may include a material supply tank 121, a blade 122, and a blade driving system 123.

[0039] The material supply tank 121 is a container for storing a raw material RM used for building the three-dimensional build object. A bottom 124 of the material supply tank 121 is movable along the Z-axis direction (namely, the up-down direction ) by a non-illustrated driving system. When the bottom 124 of the material supply tank 121 moves toward the +Z side (namely, upwardly), the raw material RM in the material supply tank 121 is supplied (for example, extruded) to an outside of the material supply tank 121. However, the material supply tank 121 may have any structure as long as the material supply tank 121 is configured to supply the raw material RM in the material supply tank 121 to the outside of the material supply tank 121.

[0040] As the raw material RM, a powder material may be used. At least one of a metal powder material and a resin powder material is one example of the powder material. However, a powder material that is different from the metal powder material and the resin powder material may be used as the raw material RM. A material that is different from the powder material may be used as the raw material RM.

[0041] The blade 122 is a member that forms the material layer ML from the raw material RM supplied (for example, extruded) from the material supply tank 121. Specifically, the blade 122 may be a plate-shape or roller-shaped member extending along a predetermined direction. However, the shape of the blade 122 is not limited to the plate-like shape or the roller-like shape. In a case where the blade 122 is the roller-shaped member, the blade 122 may be referred to as a roller. In the example illustrated in FIG. 2, the blade 122 is a plate-shaped member extending along the X-axis direction. The blade 122 is movable by the blade driving system 123 that includes a power source such as a motor along a direction that intersects a direction in which the blade 122 extends. Therefore, the blade driving system 123 may be considered to be a moving apparatus that is configured to move the blade 122. In the example illustrated in FIG. 2, an example in which the blade 122 extending along the X-axis direction is movable along the Y-axis direction by the blade driving system 123 will be described. The blade 122 may move between an end part AP of the material supply tank 121 (an end on the -Y side in the example illustrated in FIG. 2) and an end part BP of the build tank 111 (an end on the +Y side in the example illustrated in FIG. 2).

[0042] Incidentally, an amount of the raw material PM supplied from the material supply tank 121 can be changed by changing an amount of the movement (a travel amount) of the bottom 124 of the material supply tank 121. For the example, by increasing the amount of the upward movement of the bottom 124, the amount of the supplied raw material RM can be increased. In a case where the material supply tank 121 is provided above a build level (for example, a surface of the uppermost layer of the material layer ML formed by the layer forming apparatus 12) and the raw material RM is supplied from above, the layer forming apparatus 12 can supply a definable amount of the raw material RM.

[0043] Here, as illustrated in FIG. 4A that illustrates the moving blade 122, the blade 122 may move from the end part AP to the end part BP while contacting the raw material RM supplied (for example, extruded) from the material supply tank 121. Namely, the blade driving system 123 may move the blade 122 under the control of the control apparatus 2 while making the blade 122, which is allowed to contact the raw material RM, contact the raw material RM supplied (for example, extruded) from the material supply tank 121. As a result, as illustrated in FIG. 4B that illustrates the moving blade 122, the blade 122 may transfer the raw material RM supplied (for example, extruded) from the material supply tank 121 to the build tank 111. In other words, the blade 122 may supply the raw material RM supplied (for example, extruded) from the material supply tank 121 to the build tank 111 by moving from the end part AP to the end part BP. Since the blade 122 supplies the raw material RM to the build tank 111 in this manner, the blade 122 may be referred to as a material supply member.

[0044] The blade 122 may move while pushing the raw material RM downward (namely, toward the -Z side). As a result, as illustrated in FIG. 4B, as the blade 122 moves from the end part AP to the end part BP, a partial material layer PML that is a layer of the raw material RM supplied from the material supply tank 121 to the build tank 111 and that constitutes a part of the material layer ML is formed in the build tank 111 (especially, on the build plate 113 in the build tank 111). In this manner, the layer forming apparatus 12 forms the partial material layer PML by supplying the raw material RM while moving the blade 122 relative the build plate 113.

[0045] The build apparatus 1 may lower the carrier 112 and the build plate 113 by using the carrier driving system 114 each time the blade 122 moves from the end part AP to the end part BP (namely, the blade 122 forms the partial material layer PML) as illustrated in FIG. 4C. After the carrier 112 and the build plate 113 are lowered, the blade 122 may again move from the end part AP to the end part BP to form a new partial material layer PML on the partial material layer PML that has been already formed, as illustrated in FIG. 4C. Namely, the layer forming apparatus 12 supplies the raw material RM while moving the blade 122 relative to the build plate 113 to form the new partial material layer PML on the partial material layer PML that has been already formed. In this manner, the layer forming apparatus 12 may alternately repeat the movement of the blade 122 between the end part AP and the end part BP and the lowering of the build plate 113 until a thickness of the material layer ML including the plurality of partial material layers PML is equal to a desired target thickness. In this case, the layer forming apparatus 12 may alternately repeat the movement of the blade 122 between the end part AP and the end part BP and the lowering of the build plate 113 until a distance between a lower surface 1221 of the blade 122 and a surface on which the material layer ML is formed (for example, a surface of the build plate 113) is equal to the desired target thickness. In this case, as illustrated in FIG. 4D, the build plate 113 is no longer lowered at a timing at which the thickness of the material layer MLs including the plurality of partial material layers PML is equal to the desired target thickness. In this case, the lower surface 1221 of the blade 122 contacts an upper surface (namely, a surface facing toward the +Z side) MLs of the material layer ML. As a result, unnecessary raw material RM supplied to the build tank 111 is removed from the material layer ML by the blade 122. Therefore, as illustrated in FIG. 4D, the material layer ML that includes the plurality of partial material layers PML and whose thickness is equal to the desired target thickness is formed in the build tank 111 (especially, on the build plate 113 in the build tank 111).

[0046] Since the blade 122 extending along the X-axis direction moves along the Y-axis direction, the material layer ML is usually a layer that extends along the XY plane. The material layer ML is usually a layer whose upper surface (namely, the upper surface MLs of the material layer ML) is a surface along the XY plane. However, as described in detail later, there is a possibility that the upper surface MLs of the material layer ML is not the surface along the XY plane due to a positional misalignment and so on of the blade 122.

[0047] Again in FIG. 2 to FIG. 3, the beam scanning apparatus 13 is configured to emit the build light BL. The material layer ML is irradiated with the build light BL emitted from the beam scanning apparatus 13. Namely, the beam scanning apparatus 13 irradiates the material layer ML with the build light BL. When at least a part of the material layer ML is irradiated with the build light BL, at least a part of the material layer ML is molten. Then, after the build material layer ML is no longer irradiated with the build light BL, the molten material layer ML is solidified. As a result, the structural layer SL corresponding to the solidified material layer ML is formed. The structural layer SL may be equivalent to a sintered layer or a solidified layer formed by the sintering of the material layer ML. Incidentally, the build apparatus 1 may include one or more beam scanning apparatus 13.

[0048] As described above, the material layer ML is formed on the build plate 113 that is disposed in the chamber space 15SP in the chamber 15. In this case, in a case where the beam scanning apparatus 13 is disposed outside the chamber 15, the beam scanning apparatus 13 may irradiate the build material layer ML with the build light BL through an aperture 151 formed at the chamber 15. An optical window 152 through which the build light BL is allowed to pass may be disposed in the aperture 151.

[0049] The beam scanning apparatus 13 may be disposed above the build plate 113. In this case, the beam scanning apparatus 13 may irradiate the build material layer ML with the build light BL propagating along a propagating direction including the Z-axis direction as a directional component. Conversely, in the present example embodiment, the Z-axis direction may be a direction that includes, as a directional component, the propagating direction of the build light BL emitted from the beam scanning apparatus 13. The Z-axis direction may be a direction that includes, as a directional component, the propagating direction of the build light BL propagating from the beam scanning apparatus 13 toward the surface of the material layer ML.

[0050] The beam scanning apparatus 13 selectively irradiates the material layer ML with the build light BL to selectively solidify the material layer ML under the control of the control apparatus 2. In order to selectively irradiate the material layer ML with the build light BL, the beam scanning apparatus 13 may deflects the build light BL by using a scanning optical member such as a Galvano mirror. Namely, the beam scanning apparatus 13 may uses the scanning optical member such as the Galvano mirror to change an emission direction along which the build light BL is emitted from the beam scanning apparatus 13. For example, the beam scanning apparatus 13 may deflect and scan the build light BL in the θX direction and the θY direction. As a result, an irradiation position of the build light BL on the surface of the material layer ML moves along a direction that is parallel to the build plate (namely, a direction that is parallel to the material layer ML, and a direction that is parallel to the XY plane in the example illustrated in FIG. 2). In this case, the beam scanning apparatus 13 is configured to scan the material layer ML with the build light BL.

[0051] The beam scanning apparatus 13 may deflect the build light BL based on build path information that indicates a moving trajectory of the irradiation position of the build light BL so that a position indicated by the build path information is irradiated with the build light BL. The build path information is generated, for example, based on CAD data of the three-dimensional build object that should be built. Therefore, a shape of the structural layer SL to be built is almost the same as a shape of a part of the three-dimensional build object that should be built.

[0052] After building the structural layer SL, the build apparatus 1 lowers the carrier 112 and the build plate 113 by using the carrier driving system 114. After the carrier 112 and the build plate 113 are lowered, the build apparatus 1 forms a new material layer ML on the build plate 113 by using the layer forming apparatus 12. In this case, since the structural layer SL, which is a part of the three-dimensional build object, has already been formed on the build plate 113, the build apparatus 1 may form a new material layer ML on the structural layer SL that has been already formed on the build plate 113 by using the layer forming apparatus 12. Furthermore, since the material layer ML that has already been formed (especially, a part of the already formed material layer ML that has not been irradiated with the build light EL, and the material layer ML in which the structural layer SL has been formed in the same layer) has already been formed on the build plate 113, the build apparatus 1 may form a new material layer ML on the material layer ML that has been already formed on the build plate 113 by using the layer forming apparatus 12. Then, the build apparatus 1 irradiates the newly formed material layer ML with the build light BL emitted from the beam scanning apparatus 13. As a result, a new structural layer SL is built on the structural layer SL that has already been built. Namely, a new structural layer SL is stacked on the built structural layer SL that has been already built.

[0053] Then, the build apparatus 1 repeats the same operation. Namely, the build apparatus 1 alternately repeats the operation for forming the material layer ML, the operation for forming the structural layer SL by solidifying at least a part of the formed material layer ML, and an operation for lowering the carrier 112 and the build plate 113. As a result, the three-dimensional build object including the plurality of structural layers SL is formed on the build plate 113.

[0054] The measurement apparatus 14 is configured to measure a measurement target object. Specifically, the measurement apparatus 14 is configured to measure a characteristic of the measurement target object. At least one of a position of the measurement target object, a size of the measurement target object, and a shape of the measurement target object is one example of the characteristic of the measurement target object. The position of the measurement target object may include a position of a surface of the measurement target object. The size of the measurement target object may include a size of a surface of the measurement target object. The shape of the measurement target object may include a shape of a surface of the measurement target object. The shape of the measurement target object may include at least one of a one-dimensional shape of the measurement target object, a two-dimensional shape of the measurement target object, and a three-dimensional shape (in other words, a topography) of the measurement target object. Moreover, the shape of the measurement target object may include information related to a height of each position in a plane or information (point cloud information) related to coordinates of points on the surface of the measurement target information in a three-dimensional space.

[0055] The measurement target object may include the build plate 113. In this case, the measurement apparatus 14 may measure the build plate 113. For example, the measurement apparatus 14 may measure the characteristic of the build plate 113. For example, the measurement apparatus 14 may measure at least one of a position of the build plate 113, a size of the build plate 113, and a shape of the build plate 113. For example, the measurement apparatus 14 may measure at least one of a position of a surface of the build plate 113, a size of a surface of the build plate 113, and a shape of a surface of the build plate 113.

[0056] The measurement target object may include the build tank 111 disposed around the build plate 113. Especially, the measurement target object may include the side wall 1111 of the build tank 111 that is disposed around the build plate 113. In this case, the measurement apparatus 14 may measure the build tank 111 (especially, the side wall 111). For example, the measurement apparatus 14 may measure the characteristic of the build tank 111 (especially, the side wall 111). For example, the measurement apparatus 14 may measure at least one of a position of the build tank 111 (especially, the side wall 111), a size of the build tank 111 (especially, the side wall 111), and a shape of the build tank 111 (especially, the side wall 111). For example, the measurement apparatus 14 may measure at least one of a position of a surface of the build tank 111 (especially, the side wall 111), a size of a surface of the build tank 111 (especially, the side wall 111), and a shape of a surface of the build tank 111 (especially, the side wall 111).

[0057] The measurement target object may include the material layer ML formed on the build plate 113. In this case, the measurement apparatus 14 may measure material layer ML. For example, the measurement apparatus 14 may measure the characteristic of material layer ML. For example, the measurement apparatus 14 may measure at least one of a position of material layer ML, a size of material layer ML, and a shape of material layer ML. For example, the measurement apparatus 14 may measure at least one of a position of a surface of material layer ML, a size of a surface of material layer ML, and a shape of a surface of material layer ML.

[0058] The measurement target object may include the structural layer SL built from the material layer ML. In this case, the measurement apparatus 14 may measure structural layer SL. For example, the measurement apparatus 14 may measure the characteristic of structural layer SL. For example, the measurement apparatus 14 may measure at least one of a position of structural layer SL, a size of structural layer SL, and a shape of structural layer SL. For example, the measurement apparatus 14 may measure at least one of a position of a surface of structural layer SL, a size of a surface of structural layer SL, and a shape of a surface of structural layer SL. By knowing at least one of an area of the structural layer SL, the size of the area of the structural layer SL, and the shape of the structural layer SL, it is possible to calculate the amount of raw material RM required to cover the structural layer SL. In this calculation, it can be taken into account that a volume of the structural layer SL is smaller than a volume of the raw material RM. The amount of movement of the bottom 124 of the material supply tank 121 can be determined based on the required amount of the raw material RM, and the amount of movement of the bottom 124 can be changed so as to satisfy the required amount of the raw material RM.

[0059] The measurement target object may include the three-dimensional build object including plurality of structural layers SL. In this case, the measurement apparatus 14 may measure three-dimensional build object. For example, the measurement apparatus 14 may measure the characteristic of three-dimensional build object. For example, the measurement apparatus 14 may measure at least one of a position of three-dimensional build object, a size of three-dimensional build object, and a shape of three-dimensional build object. For example, the measurement apparatus 14 may measure at least one of a position of a surface of three-dimensional build object, a size of a surface of three-dimensional build object, and a shape of a surface of three-dimensional build object.

[0060] The measurement apparatus 14 may be configured to measure the measurement target object in a non-contact manner. For example, the measurement apparatus 14 may be configured to optically measure the measurement target object. For example, the measurement apparatus 14 may be configured to electrically measure the measurement target object. For example, the measurement apparatus 14 may be magnetically measure the measurement target object. For example, the measurement apparatus 14 may be configured to thermally measure measurement target object. The measurement apparatus 14 may be configured to acoustically measure the measurement target object.

[0061] The measurement apparatus 14 may be configured to measure the measurement target object by contacting the measurement target object. For example, the measurement apparatus 14 may be configured to measure the measurement target object by using a probe that physically contacts the measurement target object.

[0062] In the below-described description, an example in which the measurement apparatus 14 is configured to measure the three-dimensional shape of the measurement target object in a non-contact manner, especially, optically will be described. Especially, in the below-described description, an example in which the measurement apparatus 14 is configured to optically measure the three-dimensional shape of the measurement target object by using a projection pattern method (especially, a phase shift method) that projects a light pattern on the measurement target object and captures an image of the measurement target object on which the light pattern is projected. In this case, the measurement apparatus 14 may include a projection apparatus 141 that projects the light pattern and a capturing apparatus 142. The projection apparatus 141 is an apparatus that is configured to project, as the light pattern, a predetermined projection pattern on the measurement target object. Here, since the phase shift method is used as described above, the projection apparatus 141 projects a stripe projection pattern having an intensity distribution that varies periodically (for example, a sinusoidal intensity distribution) on the measurement target object while changing a phase of the stripe (namely, a phase of the intensity distribution). The capturing apparatus 142 is an apparatus that is configured to capture an image of the projection pattern projected on the measurement target object. In other words, the capturing apparatus 142 is an apparatus that is configured to capture an image of the measurement target object on which the projection pattern is projected. Here, since the phase shift method is used as described above, the capturing apparatus 142 captures an image of the measurement target object each time the phase of the stripe in the projection pattern changes. As a result, the capturing apparatus 142 generates a plurality of images in which a plurality of projection patterns including stripe patterns with different phases are captured, respectively, together with the measurement target object. Note that the capturing apparatus 142 may be a monocular camera or a stereo camera. The capturing apparatus 142 may be referred to as an imaging apparatus.

[0063] The plurality of images generated by the capturing apparatus 142 are outputted to the control apparatus 2 as the measured result by the measurement apparatus 14. Namely, the measurement apparatus 14 generates (acquires) the plurality of images as the measured result by the measurement apparatus 14, and output the generated (acquired) measures result to the control apparatus 2. The control apparatus 2 may calculate the three-dimensional shape of the measurement target object by performing a calculation based on the projection pattern method based on the plurality of images. For example, a shape of the stripe having the sinusoidal intensity distribution changes between the plurality of images according to the shape of the surface of the measurement target object. Therefore, there is a difference in brightness value between the plurality of images. In this case, the control apparatus 2 may assumes that luminance (the brightness value) of the same pixel changes with the same period as the projection pattern having the sinusoidal intensity distribution between the plurality of images. Furthermore, the control apparatus 2 may calculates a phase of each pixel by comparing the brightness value of each pixel with the intensity distribution of the projection pattern that has been projected at a timing at which the image has been captured. Then, the control apparatus 2 may calculate a position (in this case, a distance from a reference position, and a position or a height in the Z-axis direction) of each part of the measurement target object corresponding to each pixel by calculating a phase difference between the phase of the predetermined reference position and the phase of each pixel. A position on the build tank 111 (for example, a position on an upper surface 1112 of the side wall 1111) may be used as the reference position. In this case, the projection apparatus 141 may project the projection pattern across the measurement target object and the build tank 111 (especially, the side wall 1111). The control apparatus 2 may calculate the positions (for example, the distances from the reference position, and the positions or the heights in the Z-axis direction) of a plurality of parts of the measurement target object by repeating the above-described calculation for each pixel. Then, the control apparatus 2 may calculate, as the three-dimensional shape of the measurement target object (especially, the three-dimensional shape of the surface of the measurement target object), the shape of a virtual plane passing through the plurality of positions calculated as the positions of the plurality of parts of the measurement target object. Incidentally, in a case were the upper surface 1112 of the side wall 1111 is not located in a range of a measurable field of view of the measurement apparatus 14, a reference plate whose thickness is known may be disposed on the upper surface 1112 of the side wall 1111 to cover a space surrounded by the side wall 1111, the measurement apparatus 14 may measure the reference plate, and an value that is obtained by subtracting the thickness of the reference plate from the measured result of an upper surface of the reference plate may be used as the reference position.

[0064] Incidentally, in a case where the intensity of return light from the measurement target object on which the projection pattern is projected is too high, there is a possibility that a proportion of saturated pixels with saturated brightness values increases in the image generated by the capturing apparatus 142. For example, in a case where the return light from the measurement apparatus on which the projection pattern is projected includes specular reflection light, there is a possibility the proportion of the saturated pixels in the image generated by the capturing apparatus 142 increase. Here, the brightness value of the saturated pixel does not represent the accurate brightness value, and therefore, the saturated pixels leads to a deterioration in the accuracy of the calculation of the position of the part of the measurement target object. Therefore, the capturing apparatus 142 may generate a plurality of images by capturing an image of the measurement target object on which a certain projection pattern is projected at high speed a plurality of times, and combine the plurality of images into a single image to thereby generate the single image in which the measurement target object on which the projection pattern is captured. Such a function may be referred to as a HDR (High Dynamic Range) function. The image generated by combining the plurality of images by such a function may be referred to as a HDR image.

[0065] Note that the measurement apparatus 14 may optically measure the three-dimensional shape of the measurement target object by using an existing pattern projection method that is different from the phase shift method. At least one of a spatial coding method, a moire-topography method, and a multi-slit method is one example of the existing pattern projection method that is different from the phase shift method.

[0066] As described above, calculating the three-dimensional shape of the measurement target object may be considered to be equivalent to calculating the positions (for example, the heights or the distances from the reference position) of the plurality of parts of the measurement target object. In this case, the measurement apparatus 14 measuring the three-dimensional shape of the measurement target object may be considered to measure the positions (for example, the heights or the distances from the reference position) of the plurality of parts of the measurement target object.

[0067] The measurement apparatus 14 may measure the measurement target object by using any method for measuring the positions of the plurality of parts of the measurement target object. In this case, the control apparatus 2 may calculate the three-dimensional shape of the measurement target object based on the positions of the plurality of parts of the measurement target object measured by the measurement apparatus 14. As one example, the measurement apparatus 14 may include a TOF (Time Of Flight) sensor. In this case, the measurement apparatus 14 may perform an operation for irradiating the measurement target object with measurement light and detecting return light from the measurement target object on the plurality of parts of the measurement target object. In this case, the control apparatus 2 may calculate, based on the measured result by the measurement apparatus 14, a period between a time at which the measurement apparatus 14 emits the measurement light and a time at which the measurement apparatus 14 detects the return light, calculate, based on the calculated period, the position of each part of the measurement target object (for example, the distance from the measurement apparatus 14 to each part of the measurement target object), and calculate the three-dimensional shape of the measurement target object based on the positions of the plurality of parts of the measurement target object. Incidentally, the measurement apparatus 14 may include at least one sensor of a laser displacement sensor, an OCT (Optical Coherence Tomography) sensor, a 3D line sensor, and a triangulation sensor. Note that a non-contact measurement sensor such as the TOF sensor, the laser displacement sensor, the OCT sensor, the 3D line sensor, and the triangulation sensor may measure, as a measurement point, a single point or a plurality of points, especially, three or more points.

[0068] As described above, each of the build plate 113, the material layer ML, the structural layer SL, and the three-dimensional build object, which are examples of the measurement target object, are disposed in the chamber space 15SP in the chamber 15. In this case, in a case where the measurement apparatus 14 is disposed outside the chamber 15, the measurement apparatus 14 may measure the measurement target object through an aperture 153 formed at the chamber 15. For example, the projection apparatus 141 of the measurement apparatus 14 may project the projection pattern on the measurement target object through the aperture 153 formed at the chamber 15. For example, the capturing apparatus 142 of the measurement apparatus 14 may capture an image of the measurement target object through the aperture 153 formed at the chamber 15. An optical window 154 through which light emitted by the projection apparatus 141 to project the projection pattern and light from the measurement target object optically received by the capturing apparatus 142 to capture an image of the measurement apparatus pass may be disposed in the aperture 153. Note that at least a part of the measurement apparatus 14 may be disposed in the chamber space 15SP. The optical window 154 may have a dichroic mirror which transmits light with a wavelength that is at least one of a wavelength of the light emitted by the projection apparatus 141 and a wavelength of the light from the measurement target object optically received by the capturing apparatus 142, and reflects light with a wavelength of the build light BL. Especially, in a case where the wavelength of the build light BL is in a near-infrared region, light with a wavelength longer than the wavelength in the near-infrared region may be reflected. By this, it becomes possible to reduce an influence of heat from the chamber space 15SP on the measurement apparatus 14.

[0069] (1-3) Configuration of Control Apparatus 2 Next, with reference to FIG. 5, one example of a configuration of the control apparatus 2 in the present example embodiment will be described. FIG. 5 is a block diagram that illustrates one example of a system configuration of the control apparatus 2.

[0070] As illustrated in FIG. 5, the control apparatus 2 includes a calculation apparatus 21, a storage apparatus 22, and a communication apparatus 23. Furthermore, the control apparatus 2 may include an input apparatus 24 and an output apparatus 25. However, the control apparatus 2 may not include at least one of the input apparatus 24 and the output apparatus 25. The calculation apparatus 21, the storage apparatus 22, the communication apparatus 23, the input apparatus 24, and the output apparatus 25 may be connected through a data bus 26.

[0071] The calculation apparatus 21 is hardware that includes at least a circuit (for example, at least one of an electronic circuit and an electrical circuit). Therefore, the calculation apparatus 21 may be referred to as a circuitry (Circuitry).

[0072] The calculation apparatus 21 includes at least one processor (namely, one processor or a plurality of processors) as the hardware. The processor may include, for example, a processor conforming to a Neumann-type computer architecture. The processor conforming to the Neumann-type computer architecture may include at least one of a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit). The processor may include, for example, a processor conforming to a non-Neumann-type computer architecture. The processor conforming to a non-Neuman-type computer architecture may include at least one of an FPGA (Field Programmable Gate Array) and an ASIC (Application Specific Circuit). The processor may be realized by the circuitry (for example, at least one of the electronic circuit and the electrical circuit).

[0073] The calculation apparatus 21 reads a computer program 221 that includes at least one of a computer program code and a computer program instruction. For example, the calculation apparatus 21 may read the computer program 221 stored in the storage apparatus 22. For example, the calculation apparatus 21 may read the computer program 221 stored in a computer-readable and non-transitory recording medium by using a non-illustrated recording medium reading apparatus of the control apparatus 2. The computer program 221 read from the recording medium may be stored in the storage apparatus 22. The calculation apparatus 21 may acquire (namely, may download or read) the computer program 221 from a non-illustrated apparatus located outside the control apparatus 2 through the communication apparatus 23 (alternatively, other communication apparatus). The downloaded computer program 221 may be stored in the storage apparatus 22.

[0074] The calculation apparatus 21 executes the read computer program 221. As a result, a logical functional block for performing a process that should be performed by the control apparatus 2 (for example, a process for controlling the build apparatus 1 described above) is implemented in the calculation apparatus 21. In other words, the calculation apparatus 21 is configured to, together with the storage apparatus 22 and so on in which the computer program 221 is recorded (in other words, together with the storage apparatus 22 and the computer program 221 stored in the storage apparatus 22 and so on), serve as a controller or a computer for implementing the logical functional block for performing the process that should be performed by the control apparatus 2. Namely, a memory (a recording medium) of the storage apparatus 22 and so on and the computer program 221 are configured to, together with at least one processor of the calculation apparatus 21, allow the control apparatus 2 to perform the process that should be performed by the control apparatus 2 (for example, a process for controlling the build apparatus 1 described above).

[0075] The calculation apparatus 21 may include a single processor. In this case, the calculation apparatus 21 may use the single processor to perform the process that should be performed by the control apparatus 2 (for example, the process for controlling the build apparatus 1 described above). For example, in a case where the calculation apparatus 21 performs a first operation (for example, a first process that is a part of the process for controlling the build apparatus 1) and a second operation (for example, a second process that is another part of the process for controlling the build apparatus 1), the calculation apparatus 21 may perform both of the first and second operations by using the single processor. Alternatively, the calculation apparatus 21 may include a plurality of processors. In this case, the calculation apparatus 21 may use any one of the plurality of processors to perform the process that should be performed by the control apparatus 2 (for example, the process for controlling the build apparatus 1 described above). For example, in a case where the calculation apparatus 21 includes first and second processors and performs the first and second operations, the calculation apparatus 21 may perform each of the first and second operations by using any one of the first and second processors. For example, the calculation apparatus 21 may perform the first operation by using the first processor, may perform the second operation by using the first processor, may perform the first operation by using the second processor, and may perform the second operation by using the second processor.

[0076] An arithmetic model that is buildable by machine learning may be implemented in the calculation apparatus 21 by the calculation apparatus 21 executing the computer program 221. One example of the arithmetic model that is buildable by the machine learning is an arithmetic model including a neural network (so-called Artificial Intelligence (AI)), for example. In this case, the learning of the arithmetic model may include learning of parameters of the neural network (for example, at least one of weights and biases). The calculation apparatus 21 may control the build apparatus 1 1 by using the arithmetic model. Namely, the operation for controlling the build apparatus 1 may include an operation for controlling the build apparatus 1 by using the arithmetic model. Note that the arithmetic model that has been built by off-line machine learning using training data may be implemented in the calculation apparatus 21. Moreover, the arithmetic model implemented in the calculation apparatus 21 may be updated by online machine learning on the calculation apparatus 21. Alternatively, the calculation apparatus 21 may control the build apparatus 1 by using the arithmetic model implemented in an apparatus external to the calculation apparatus 21 (namely, an apparatus external to the control apparatus 2), in addition to or instead of the arithmetic model implemented on the calculation apparatus 21.

[0077] Note that the recording medium recording therein the computer program 221 that is executed by the calculation apparatus 21 may include an optical disc such as a CD-ROM, a CD-R, a CD-RW, a flexible disc, a MO, a DVD-ROM, a DVD-RAM, a DVD-R, a DVD+R, a DVD-RW, a DVD+RW and a Blu-ray (registered trademark), a magnetic disc such as a magnetic tape, an optical-magnetic disc, a semiconductor memory such as a USB memory, and another medium that is configured to store the program. The recording medium may include a device that is configured to record the computer program 221 (for example, a device for a universal use or a device for an exclusive use in which the computer program 221 is embedded to be executable in a form of at least one of a software, a firmware and the like). Moreover, each process or function included in the computer program 221 may be realized by a logical process block that is realized in the calculation apparatus 21 by means of the calculation apparatus 21 (namely, the processor) executing the computer program 221, may be realized by a hardware such as a predetermined gate array (a FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit)) of the calculation apparatus 21, or may be realized in a form in which the logical process block and a partial hardware module that realizes an partial element of the hardware are combined.

[0078] The storage apparatus 22 includes at least one memory that is configured to store desired data. In other words, the storage apparatus 22 includes at least one memory that contains the desired data. The memory may be realized by a circuitry (for example, at least one of an electronic circuit and an electrical circuit). For example, the storage apparatus 22 may store the computer program 221 to be executed by the calculation apparatus 21. In this case, the storage apparatus 22 (the memory) may be used as the above-described recording medium that records the computer program 221 to be executed by the calculation apparatus 21. The storage apparatus 22 may temporarily store data that is temporarily used by the calculation apparatus 21 when the calculation apparatus 21 is executing the computer program 221. The storage apparatus 22 may store data for long-term storage by the control apparatus 2. Incidentally, the storage apparatus 22 may include at least one of a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk apparatus, a magneto-optical disk apparatus, a SSD (Solid State Drive) and a disk array apparatus. Namely, the storage apparatus 22 may include a non-transitory recording medium.

[0079] The communication apparatus 23 is configured to communicate with the build apparatus 1 through a non-illustrated communication network (see FIG. 1). Alternatively, the communication apparatus 23 may be configured to communicating with another apparatus different from the build apparatus 1in addition to or instead of the build apparatus 1 through the non-illustrated communication network. In the present example embodiment, the communication apparatus 23 may receive (namely, acquire) the measured result by the position measurement apparatus 115 and the measured result by the measurement apparatus 14 from the build apparatus 1. Furthermore, the communication apparatus 23 may transmit (namely, output) a signal for controlling the build apparatus 1 to the build apparatus 1.

[0080] The input apparatus 24 is an apparatus that is configured to receive an input of information to the control apparatus 2 from an outside of the control apparatus 2. For example, the input apparatus 24 may include an operational apparatus (for example, at least one of a keyboard, a mouse, and a touch panel) that is allowed to be operated by a user of the control apparatus 2. For example, the input apparatus 24 may include a recording medium reading apparatus that is configured to read information recorded as data on a recording medium that is externally attachable to the control apparatus 2.

[0081] Incidentally, the information is allowed to be inputted to the control apparatus 2 as the data from the apparatus external to the control apparatus 2 through the communication apparatus 23. In this case, the communication apparatus 23 may serve as an input apparatus that is configured to receive the input of the information to the control apparatus 2 from the apparatus external to the control apparatus 2.

[0082] The output apparatus 25 is an apparatus that is configured to output information to the outside of the control apparatus 2. For example, the output apparatus 25 may output information as an image. Namely, the output apparatus 25 may include a display apparatus (a so-called display) configured to display the image. For example, the output apparatus 25 may output information as audio. Namely, the output apparatus 25 may include an audio apparatus (a so-called speaker) configured to output the audio. For example, the output apparatus 25 may output information on a paper. Namely, the output apparatus 25 may include a printing apparatus (a so-called printer) configured to print desired information on paper. For example, the output apparatus 25 may output information as data on a recording medium that is externally attachable to the control apparatus 2.

[0083] Incidentally, the information is allowed to be outputted as the data from the control apparatus 2 to the apparatus external to the control apparatus 2 through the communication apparatus 23. In this case, the communication apparatus 23 may serve as an output apparatus that is configured to output the information to the apparatus external to the control apparatus 2.

[0084] (2) Build Operation performed by Build System SYS Next, with reference to FIG. 6, a build operation performed by the build system SYS will be described. FIG. 6 is a flowchart that illustrates a flow of the build operation performed by the build system SYS.

[0085] (2-1) Placing Build Plate 113 First, the build plate 113 is placed on the carrier 112 (a step S11). Especially, a new build plate 113 on which the three-dimensional build object is to be built is placed on the carrier 112 (the step S11). For example, in a case where no build plate 113 is placed on the carrier 112, a new build plate 113 may be placed on the carrier 112 on which no build plate 113 is placed. For example, in a case where the build plate 113 on which the three-dimensional build object has already been built is already placed on the carrier 112, the build plate 113 on which the three-dimensional build object has been built may be removed from the carrier 112, and then a new build plate 113 on which the three-dimensional build object is to be built may be placed on the carrier 112. Note that the build plate 113 may be fixed to the carrier 112.

[0086] (2-2) Rough Alignment Operation Then, the control apparatus 2 adjusts a position of the build plate 113 (a step S12). Especially, the control apparatus 2 adjusts the position of the build plate 113 before the material layer ML is formed on the build plate 113 that has been placed on the carrier 112 at the step S11 (the step S12). Especially, the control apparatus 2 adjusts the position of the build plate 113 before the first material layer ML is formed on the build plate 113 that has been placed on the carrier 112 at the step S11 (the step S12). Incidentally, for convenience of description, an operation for adjusting the position of the build plate 113 at the step S12 is referred to as a rough alignment operation in the below-described description, as necessary.

[0087] The control apparatus 2 may adjust the position of the build plate 113 along at least one of the X-axis , the Y-axis, and the Z-axis by moving the build plate 113 along at least one of the X-axis, the Y-axis, and the Z-axis. The control apparatus 2 may adjust the position of the build plate 113 along at least one of the rotational direction around the X-axis, the rotational direction around the Y-axis, and the rotational direction around the Z-axis by moving (namely, rotating) the build plate 113 around at least one of the rotation axis along the X-axis, the rotation axis along the Y-axis, and the rotation axis along the Z-axis.

[0088] The control apparatus 2 may adjust the position of the build plate 113 by controlling the carrier driving system 114 that is configured to move the build plate 113 through the carrier 112. Namely, the control apparatus 2 may control the carrier driving system 114 that is configured to move the build plate 113 so as to adjust the position of the build plate 113. In the above-described description, the carrier driving system 114 is configured to move the build plate 113 along the translation axis along the Z-axis, and is configured to move the build plate 113 around at least one of the rotation axis along the X-axis and the rotation axis along the Y-axis. In this case, as illustrated in FIG. 7 that is a cross-sectional view illustrating the build plate 113 whose position is adjusted by the rough alignment operation, the control apparatus 2 may control the carrier driving system 114 to adjust at least one of the position of the build plate 113 in the Z-axis direction, the position of the build plate 113 in the rotational direction around the X-axis (namely, the attitude of the build plate 113 around the X-axis), and the position of the build plate 113 in the rotational direction around the Y-axis (namely, the attitude of the build plate 113 around the Y-axis). Incidentally, FIG. 7 omits the illustration of the carrier 112 on which the build plate 113 is placed and whose position (attitude) is adjusted by the carrier driving system 114.

[0089] At the step S12, the control apparatus 2 may adjust the position of the build plate 113 based on the measured result of the position of at least one of the carrier 112 and the build plate 113 by the position measurement apparatus 115. In this case, the rough alignment operation may include an operation for adjusting the position of the build plate 113 based on the measured result of the position of at least one of the carrier 112 and the build plate 113 by the position measurement apparatus 115. Incidentally, in a case where the build plate 113 is a reused build plate, a thickness of the build plate 113 may be measured with another measurement apparatus. Moreover, both the carrier 112 and the build plate 113 may be measured by the measurement apparatus 14, and the thickness of the build plate 113 may be calculated by using the output of the measurement apparatus 14 when the carrier 112 is measured, the output of the position measurement apparatus 115 at this time, the output of the measurement apparatus 14 when the build plate 113 is measured, and the output of the position measurement apparatus 115 at this time. In the latter case, it can be said that the thickness of the build plate 113 is determined by using the position measurement apparatus 115.

[0090] In a case where the build plate 113 is reused, there is a possibility that a previously build object and / or a residue from building remain on the build plate 113. Moreover, even in a case where the build plate 113 used in the previous build operation has not been replaced, there is a possibility that the previously build object and / or the residue from building remain on the build plate 113. In such cases, when the position of the build plate 113 in the Z direction is moved to a position of the build tank 111 (for example, to a position of the upper surface 1112 of the side wall 1111), there is a possibility that the previously build object and / or the residue from the building hits the chamber 15, typically an upper surface of the chamber 15.

[0091] Therefore, the measurement apparatus 14 may measure the shape of the upper surface of the build plate 113 attached to the build apparatus 1. In a case where the shape of the upper surface of the build plate 113 is flat, it can be confirmed that there is no previously build object and / or residue from building. Such a safety verification procedure may be performed before and / or during the rough alignment operation. Especially, the safety verification procedure may be performed by continuously or discretely monitoring the build plate 113 as it moves upwardly.

[0092] One example of the rough alignment operation is illustrated in FIG. 8 that is a cross-sectional view illustrating the build plate 113 whose position is adjusted by the rough alignment operation. As illustrated in FIG. 8, the control apparatus 2 may calculate a height of an upper surface (namely, a surface facing toward the +Z side) 1131 of the build plate 113 based on the measured result by the position measurement apparatus 115. Namely, the control apparatus 2 may calculate the position along the Z-axis direction of the upper surface 1131 of the build plate 113 as the height of the upper surface 1131 of the build plate 113 based on the measured result by the position measurement apparatus 115. Then, the control apparatus 2 may adjust the position of the build plate 113 based on a calculated result of the height of the upper surface 1131 of the build plate 113.

[0093] As a first example, the control apparatus 2 may adjust the position of the build plate 113 so as to satisfy such a first alignment condition that “the upper surface 1131 of the build plate 113 is included in a measurement range of the measurement apparatus 14”. The measurement range of the measurement apparatus 14 may be a range that satisfies such a condition that the projection apparatus 141 of the measurement apparatus 14 can project the projection pattern on the measurement target object located in the measurement range and the light from the measurement target object located in the measurement range can enter the capturing apparatus 142 of the measurement apparatus 14. As one example, the control apparatus 2 may adjust the position of the build plate 113 along the Z-axis direction so that the upper surface 1131 of the build plate 113 is included in the measurement range of the measurement apparatus 14 in the Z-axis direction. In a case where the rough alignment operation is performed so as to satisfy the first alignment condition, the measurement apparatus 14 can properly measure the measurement target object. Note that the above-described first alignment condition may be such a condition that “the upper surface 1131 of the build plate 113 is included in the measurement range of the measurement apparatus 14 at a plurality of positions in the upper surface 1131”.

[0094] As a second example, the control apparatus 2 may adjust the position of the build plate 113 so as to satisfy such a second alignment condition “the upper surface 1131 of the build plate 113 is included in a measurement accuracy guarantee range of the measurement apparatus 14”, in addition to or instead of satisfying the first alignment condition. The measurement accuracy guarantee range of the measurement apparatus 14 may be a range that satisfies such a condition that a measurement accuracy of the measurement apparatus 14 measuring the measurement target object located in the measurement accuracy guarantee range is higher than a predetermined allowable accuracy. This measurement accuracy guarantee range may be a part of the above-described measurement range or may be the same as the above-described measurement range. As one example, the control apparatus 2 may adjust the position of the build plate 113 along the Z-axis direction so that the upper surface 1131 of the build plate 113 is included in the measurement accuracy guarantee range of the measurement apparatus 14 in the Z-axis direction. In a case where the rough alignment operation is performed so as to satisfy the second alignment condition, the measurement apparatus 14 can properly measure the measurement target object. Especially, the measurement apparatus 14 can accurately measure the measurement target object. Note that the above-described first alignment condition may be such a condition that “the upper surface 1131 of the build plate 113 is included in the measurement accuracy guarantee range of the measurement apparatus 14 at a plurality of positions in the upper surface 1131”.

[0095] As a third example, the control apparatus 2 may calculate a difference (a height difference) Δz between the height of the upper surface 1131 of the build plate 113 and a height of an upper surface (namely, a surface facing toward the +Z side) 1112 of the build tank 111 based on the calculated result of the height of the upper surface 1131 of the build plate 113. The upper surface 1112 of the build tank 111 may mean an upper surface (namely, a surface facing toward the +Z side) of the side wall 1111 of the build tank 111. Since the build tank 111 is basically immobile, the height of the upper surface 1112 of the build tank 111 may be information known to the control apparatus 2. As a result, the control apparatus 2 may calculate the height difference Δz based on the calculated height of the upper surface 1131 of the build plate 113 and the known information related to the height of the upper surface 1112 of the build tank 111. Incidentally, the height difference Δz between the height of the upper surface 1131 of the build plate 113 and the height of the upper surface 1112 of the build tank 111 may mean a distance between the upper surface 1131 of the build plate 113 and the upper surface 1112 of the build tank 111 in the Z-axis direction. Then, the control apparatus 2 may adjust the position of the build plate 113 so as to satisfy such a third alignment condition that “the height difference Δz is equal to or smaller than a predetermined allowable height threshold value”, in addition to or instead of satisfying at least one of the first and second alignment conditions. Note that the above-described height difference Δz may be calculated at a plurality of positions in the XY plane (a plane that is substantially parallel to the upper surface 1131 of the build plate 113).

[0096] For example, in a case where the position on the build tank 111 (for example, the position on the upper surface 1112 of the side wall 111) is used as the reference position for the phase shift method as described above, the measurement apparatus 14 may project the projection pattern across the build plate 113 and the build tank 111 (especially, the side wall 111) as described above. If the height difference Δz is too large under this environment, there is a possibility that either one of the upper surface 1131 of the build plate 113 and the upper surface 1112 of the build tank 111 is included in the measurement range (alternatively, measurement accuracy guarantee range) of the measurement apparatus 14 described above but the other one of the upper surface 1131 of the build plate 113 and the upper surface 1112 of the build tank 111 is not included in the measurement range (alternatively, the measurement accuracy guarantee range) of the measurement apparatus 14 described above. In this case, there is a possibility that the control apparatus 2 cannot calculate the phase difference between a phase of a pixel in which a part of the upper surface 1112 of the build tank 111 used as the predetermined reference position is captured and a phase of a pixel in which a part of the build plate 113 is captured based on the measured result by the measurement apparatus 14. As a result, there is a possibility that the control apparatus 2 cannot calculate the position (for example, the distance from the reference position, and the position or the height in the Z-axis direction) of each part of the build plate 113 based on the measured result by the measurement apparatus 14. Therefore, the control apparatus 2 may adjust the position of the build plate 113 until the height difference Δz is equal to or smaller than a predetermined allowable height threshold value so that the height difference Δz is not too large. As one example, the control apparatus 2 may adjust the position of the build plate 113 along the Z-axis direction until the height difference Δz is equal to or smaller than the predetermined allowable height threshold value so that the height difference Δz is not too large. In this case, the predetermined allowable height threshold value may be set based on a size of the measurement range (alternatively, the measurement accuracy guarantee range) of the measurement apparatus 14. For example, the predetermined allowable height threshold value may be set based on the size of the measurement range (alternatively, the measurement accuracy assurance range) of the measurement apparatus 14 in the Z-axis direction. For example, the predetermined allowable height threshold value may be set to a value that is equal to or smaller than the size of the measurement range (alternatively, the measurement accuracy guarantee range) of the measurement apparatus 14 in the Z-axis direction. In a case where the rough alignment operation is performed so as to satisfy the third alignment condition, the control apparatus 2 can properly calculate the position of each part of the build plate 113 based on the measured result by the measurement apparatus 14.

[0097] As a fourth example, as illustrated in FIG. 9 that is a cross-sectional view illustrating the build plate 113 whose position is adjusted by the rough alignment operation, in a case where the build plate 113 protrudes from the upper surface 1112 of the build tank 111 too much, there is a possibility that the blade 122 that moves to form the material layer ML collides with the build plate 113. Therefore, the control apparatus 2 may calculate a protrusion amount PD of the upper surface 1131 of the build plate 113 from the upper surface 1112 of the build tank 111 based on the calculated result of the height of the upper surface 1131 of the build plate 113 and the known information related to the height of the upper surface 1112 of the build tank 111. The protrusion amount PD of the upper surface 1131 of the build plate 113 from the upper surface 1112 of the build tank 111 may mean the protrusion amount of the upper surface 1131 of the build plate 113 from the upper surface 1112 of the build tank 111 in the Z-axis direction. Especially, the protrusion amount PD of the upper surface 1131 of the build plate 113 from the upper surface 1112 of the build tank 111 may mean the protrusion amount whose sign is positive in a case where the upper surface 1131 of the build plate 113 protrudes toward the +Z side from the upper surface 1112 of the build tank 111 in the Z-axis direction. In this case, in a case where the upper surface 1131 of the build plate 113 is concave toward the -Z side from the upper surface 1112 of the build tank 111 in the Z-axis direction, the protrusion amount PD may be a negative value. Then, the control apparatus 2 may adjust the position of the build plate 113 so as to satisfy such a fourth alignment condition that “the protrusion amount PD is equal to or smaller than a predetermined allowable protrusion amount”, in addition to or instead of satisfying at least one of the first to third alignment conditions. As one example, the control apparatus 2 may adjust the position of the build plate 113 in the Z-axis direction so that the protrusion amount PD is equal to or smaller than the predetermined allowable protrusion amount. The predetermined allowable protrusion amount may be set to be a desired value by which the protrusion amount PD in a case where the blade 122 that moves to form the material layer ML collides with the build plate 113 is distinguishable from the protrusion amount PD in a case where the blade 122 that moves to form the material layer ML does not collide with the build plate 113. The predetermined allowable protrusion amount may be a positive value or may be a negative value. In a case where the rough alignment operation is performed so as to satisfy the fourth alignment condition, there is a lower or no possibility that the blade 122 that move to form the material layer ML collides with the build plate 113. Note that the above-described protrusion amount PD may be calculated at a plurality of positions in the XY plane (a plane that is substantially parallel to the upper surface 1131 of the build plate 113).

[0098] In parallel with the rough alignment operation, the control apparatus 2 may control the heater 116 to preheat the build plate 113. Alternatively, after the rough alignment operation is completed, the control apparatus 2 may control the heater 116 to preheat the build plate 113. Alternatively, before starting the rough alignment operation, the control apparatus 2 may control the heater 116 to preheat the build plate 113.

[0099] Note that the control apparatus 2 may not perform the rough alignment operation at the step S12.

[0100] (2-3) Fine Alignment Operation Again in FIG. 6 again, then, the control apparatus 2 adjusts the position of the build plate 113 by a method that is different from the rough alignment operation at the step S12 (a step S13). Especially, the control apparatus 2 adjusts the position of the build plate 113 before the material layer ML is formed on the build plate 113 that has been placed on the carrier 112 at the step S11 (the step S13). Especially, the control apparatus 2 adjusts the position of the build plate 113 before the first material layer ML is formed on the build plate 113 that has been placed on the carrier 112 at the step S11 (the step S13). Incidentally, for convenience of description, an operation for adjusting the position of the build plate 113 at the step S13 is referred to as a fine alignment operation in the below-described description, as necessary.

[0101] In the present example embodiment, the fine alignment operation is an operation for adjusting the position of the build plate 113 based on the measured result of the build plate 113 by the measurement apparatus 14. In this case, the fine alignment operation at the step S13 may be different from the rough alignment operation, which is an operation for adjusting the position of the build plate 113 based on the measured result of at least one of the carrier 112 and the build plate 113 by the position measurement apparatus 115, in that it is the operation for adjusting the position of the build plate 113 based on the measured result of the build plate 113 by the measurement apparatus 14.

[0102] Therefore, at the step S13, the measurement apparatus 14 firstly measures the build plate 113. Incidentally, in a case where the position of the build plate 113 has been adjusted to satisfy at least one of the first to fourth alignment conditions by the above-described rough alignment operation at the step S12, the measurement apparatus 14 can properly measure the build plate 113 at the step S13.

[0103] Then, the control apparatus 2 may adjust the position of the build plate 113 based on the measured result of the build plate 113 by the measurement apparatus 14. For example, the control apparatus 2 may adjust the position of the build plate 113 along at least one of the X-axis, the Y-axis, and the Z-axis by moving the build plate 113 along at least one of the X-axis, the Y-axis, and the Z-axis, as in a case where the rough alignment operation is performed. For example, the control apparatus 2 may adjust the position of the build plate 113 along at least one of the rotational direction around the X-axis, the rotational direction around the Y-axis, and the rotational direction around the Z-axis by moving (namely, rotating) the build plate 113 around at least one of the rotation axis along the X-axis, the rotation axis along the Y-axis, and the rotation axis along the Z-axis, as in a case where the rough alignment operation is performed.

[0104] As a first example, the control apparatus 2 may calculate the position of the build plate 113 in the direction along the predetermined translation axis based on the measured result of the build plate 113 by the measurement apparatus 14. Then, the control apparatus 2 may adjust the position of the build plate 113 in the direction along the predetermined translation axis based on the calculated result of the position of the build plate 113 in the direction along the predetermined translation axis so that the build plate 113 is located at a desired target position in the direction along the predetermined translation axis.

[0105] For example, the control apparatus 2 may calculate the position of the build plate 113 in the Z-axis direction based on the measured result of the build plate 113 by the measurement apparatus 14. Then, the control apparatus 2 may n adjust the position of the build plate 113 in the Z-axis direction based on the calculated result of the position of the build plate 113 in the Z-axis direction so that the build plate 113 is located at the desired target position in the Z-axis direction.

[0106] As a second example, the control apparatus 2 may calculate the position of the build plate 113 in the rotational direction around the predetermined rotation axis (namely, the attitude of the build plate 113 around the predetermined rotation axis) based on the measured result of the build plate 113 by the measurement apparatus 14. Then, the control apparatus 2 may adjust the position of the build plate 113 in the rotational direction around the predetermined rotation axis based on the calculated result of the position of the build plate 113 in the rotational direction around the predetermined rotation axis so that the build plate 113 is located at the desired target position in the rotational direction around the predetermined rotation axis. In other words, the control apparatus 2 may adjust the attitude of the build plate 113 around the predetermined rotation axis based on the calculated result of the attitude of the build plate 113 around the predetermined rotation axis so that the attitude of the build plate 113 around the predetermined rotation axis is a desired target attitude.

[0107] For example, the control apparatus 2 may calculate the position of the build plate 113 in the rotational direction around the X-axis (namely, the attitude of the build plate 113 around the X-axis) based on the measured result of the build plate 113 by the measurement apparatus 14. Then, the control apparatus 2 may n adjust the position of the build plate 113 in the rotational direction around the X-axis based on the calculated position of the build plate 113 in the rotational direction around the X-axis so that the build plate 113 is located at the desired target position in the rotational direction around the X-axis. In other words, the control apparatus 2 may adjust the attitude of the build plate 113 around the X-axis based on the calculated results of the attitude of the build plate 113 around the X-axis so that the attitude of the build plate 113 around the X-axis is the desired target attitude.

[0108] For example, the control apparatus 2 may calculate the position of the build plate 113 in the rotational direction around the Y-axis (namely, the attitude of the build plate 113 around the Y-axis) based on the measured result of the build plate 113 by the measurement apparatus 14. Then, the control apparatus 2 may n adjust the position of the build plate 113 in the rotational direction around the Y-axis based on the calculated position of the build plate 113 in the rotational direction around the Y-axis so that the build plate 113 is located at the desired target position in the rotational direction around the Y-axis. In other words, the control apparatus 2 may adjust the attitude of the build plate 113 around the Y-axis based on the calculated results of the attitude of the build plate 113 around the Y-axis so that the attitude of the build plate 113 around the Y-axis is the desired target attitude.

[0109] The desired target position may be set so as to satisfy such a condition that “the thickness of the material layer ML formed by supplying the raw material RM while moving the blade 122 relative to the build plate 113 located at the desired target position is equal to the desired target thickness”. The desired target position may be set so as to satisfy such a condition that “the build plate 113 located at the desired target position satisfies at least one of the first to fourth alignment conditions described above. Incidentally, in a case where the desired target position is set so as to satisfy the condition that “the build plate 113 located at the desired target position satisfies at least one of the first to fourth alignment conditions described above”, the control apparatus 2 may be considered to perform the fine alignment operation (namely, adjust the position of the build plate 113) so as to satisfy at least one of the first to fourth alignment conditions described above. Here, the desired target position may be set so as to satisfy such a condition that “the thickness of the material layer ML formed by supplying the raw material RM while moving the blade 122 relative to the build plate 113 located at the desired target position is equal to the desired target thickness” at a plurality of positions in the XY plane (a plane that is substantially parallel to the upper surface 1131 of the build plate 113 and / or the upper surface MLs of the material layer ML).

[0110] The desired target attitude may be set so as to satisfy such a condition that “the thickness of the material layer ML formed by supplying the raw material RM while moving the blade 122 relative to the build plate 113 in the desired target attitude is equal to the desired target thickness”. The desired target attitude may be set so as to satisfy such a condition that “the upper surface 1131 of the build plate 113 in the desired target attitude is a horizontal surface. The desired target attitude may be set so as to satisfy such a condition that “the build plate 113 in the desired target attitude satisfies at least one of the first to fourth alignment conditions described above. Incidentally, in a case where the desired target attitude is set so as to satisfy the condition that “the build plate 113 in the desired target attitude satisfies at least one of the first to fourth alignment conditions described above”, the control apparatus 2 may be considered to perform the fine alignment operation (namely, adjust the position of the build plate 113) so as to satisfy at least one of the first to fourth alignment conditions described above. Note that the above-described condition may be a condition that “the thickness of the material layer ML formed by supplying the raw material RM while moving the blade 122 relative to the build plate 113 in the desired target attitude is equal to the desired target thickness at a plurality of positions in the XY plane”.

[0111] Incidentally, in a case where the fine alignment operation is performed so as to satisfy the third alignment condition “the height difference Δz between the height of the upper surface 1131 of the build plate 113 and the height of the upper surface 1112 of the build tank 111 is equal to or smaller than the predetermined allowable height threshold value”, the measurement apparatus 14 may measure the build tank 111 (especially, the side wall 1111) in addition to measuring the build plate 113. Then, the control apparatus 2 may calculate the height of the upper surface 1131 of the build plate 113 and the upper surface 1112 of the build tank 111 based on the measured result of the build plate 113 and the build tank 111 (especially, the side wall 1111) by the measurement apparatus 14. Then, the control apparatus 2 may calculate the height difference Δz based on the calculated result of the height of the upper surface 1131 of the build plate 113 and the height of the upper surface 1112 of the build tank 111. Then, the control apparatus 2 may adjust the position of the build plate 113 so that the height difference Δz is equal to or smaller than the predetermined allowable height threshold value. In this case, the control apparatus 2 actually calculates the height of the upper surface 1112 of the build tank 111 to calculate the height difference Δz, and therefore the height difference Δz can be calculated more accurately. Note that the above-described third alignment condition may be such a condition that “the height difference Δz between the height of the upper surface 1131 of the build plate 113 and the height of the upper surface 1112 of the build tank 111 is equal to or smaller than the predetermined allowable height threshold value at a plurality of positions in the XY plane”

[0112] The control apparatus 2 may perform the fine alignment operation after the heater 116 preheats the build plate 113. The control apparatus 2 may perform the fine alignment operation after the heater 116 has completed preheating the build plate 113. In this case, the control apparatus 2 can perform the fine alignment operation under a thermal environment that is the same as a thermal environment in a case where the building operation for building the three-dimensional build object is performed on the build plate 113. Therefore, the control apparatus 2 can perform the fine alignment operation by considering an effect of a thermal expansion of the build plate 113 that occurs in a case where the build operation for building the three-dimensional build object is performed on the build plate 113. In this case, there is a lower possibility that the position of the build plate 113 that has been adjusted by the fine alignment operation deviates from the above described target position due to the thermal expansion of the build plate 113 that occurs after the fine alignment operation is performed, compared to a case where the build plate 113 is preheated after the fine alignment operation is performed or the build plate 113 is not preheated. Similarly, there is a lower possibility that the attitude of the build plate 113 that has been adjusted by the fine alignment operation deviates from the above described target attitude due to the thermal expansion of the build plate 113 that occurs after the fine alignment operation is performed, compared to a case where the build plate 113 is preheated after the fine alignment operation is performed or the build plate 113 is not preheated. Therefore, in a case where the fine alignment operation is performed after the build plate 113 is preheated, there is a lower possibility that the build accuracy of the build apparatus 1 deteriorates, compared to a case where the build plate 113 is preheated after the fine alignment operation is performed or the build plate 113 is not preheated. Namely, the build apparatus 1 can build the three-dimensional build object with relatively high build accuracy.

[0113] Note that the control apparatus 2 may not perform the fine alignment operation at the step S13.

[0114] (2-4) Measurement of Build Plate 113 Then, the measurement apparatus 14 measures the build plate 113 (a step S14). Namely, the measurement apparatus 14 measures the build plate 113 after the rough alignment operation and the fine alignment operation are performed. Conversely, the control apparatus 2 performs the rough alignment operation and the fine alignment operation before the measurement apparatus 14 measures the build plate 113 at the step S14.

[0115] However, in a case where the rough alignment operation is not performed as described above, the measurement apparatus 14 may measure the build plate 113 on which the rough alignment operation is not performed at the step S14. In a case where fine alignment operation is not performed as described above, the measurement apparatus 14 may measure the build plate 113 on which the fine alignment operation is not performed at the step S14.

[0116] At a timing at which the operation at the step S14 is performed, the material layer ML has not yet been formed on the build plate 113. Therefore, at the step S14, the measurement apparatus 14 measures the build plate 113 on which the material layer ML has not yet been built before the material layer ML is formed on the build plate 113.

[0117] At the step S14, the measurement apparatus 14 measures the three-dimensional shape of the build plate 113. Namely, the measurement apparatus 14 measures the positions (for example, the positions or the heights in the Z-axis direction, and the distances from the reference position) of the plurality of parts of the build plate 113. Especially, at the step S14, the measurement apparatus 14 measures the three-dimensional shape of the upper surface 1131 of the build plate 113. Namely, the measurement apparatus 14 measures the positions (for example, the positions or the heights in the Z-axis direction, and the distances from the reference position) of the plurality of parts of the upper surface 1131 of the build plate 113. The measured result of the build plate 113 by the measurement apparatus 14 at the step S14 is outputted to the control apparatus 2. Incidentally, for convenience of description, the measured result of the build plate 113 by the measurement apparatus 14 at the step S14 is referred to as a plate measured result in the below-described description. The control apparatus 2 acquires, from the measurement apparatus 14, the plate measured result outputted from the measurement apparatus 14. The plate measured result acquired by the control apparatus 2 is used to control at least one of the layer forming apparatus 12 and the carrier driving system 114 at a step S17 described below. Namely, the plate measured result acquired by the control apparatus 2 is used to make at least one of the layer forming apparatus 12 and the carrier driving system 114 operate at the step S17 described below. Therefore, a description of a usage of the plate measured result is omitted here.

[0118] As described above, the fine alignment operation, which is performed before the measurement apparatus 14 measures the build plate 113 at the step S14, may be performed after the build plate 113 is preheated. In this case, at the step S14, the measurement apparatus 14 may measure the build plate 113 after the build plate 113 is preheated. Namely, the measurement apparatus 14 may measure the build plate 113 after the heater 116 has completed preheating the build plate 113. In this case, the measurement apparatus 14 can measure the build plate 113 under the thermal environment that is the same as the thermal environment in a case where the building operation for building the three-dimensional build object is performed on the build plate 113. Therefore, the plate measured result that is the measured result by the measurement apparatus 14 includes a component related to the thermal expansion of the build plate 113 that occurs in a case where the build operation for building the three-dimensional build object is performed on the build plate 113. In this case , the control apparatus 2 can adjust a positional relationship between the build plate 113 and the blade 122 while taking into account the effect of the thermal expansion of the build plate 113 at the step S17 described below, compared to the case where the build plate 113 is preheated after the measurement apparatus 14 measures the build plate 113 at the step S14 or the build plate 113 is not preheated. Therefore, there is a lower possibility that the build accuracy of the build apparatus 1 deteriorates, compared to the case where the build plate 113 is preheated after the measurement apparatus 14 measures the build plate 113 at the step S14 or the build plate 113 is not preheated. Namely, the build apparatus 1 can build the three-dimensional build object with relatively high build accuracy.

[0119] (2-5) Forming of Material Layer ML Then, the control apparatus 2 controls the layer forming apparatus 12 to form the material layer ML on the build plate 113 (a step S15). Especially, at the step S15, the control apparatus 2 controls the layer forming apparatus 12 to form the first material layer ML on the build plate 113. Namely, at the step S15, the control apparatus 2 controls the layer forming apparatus 12 to form the first material layer ML, which is used to build the first structural layer SL, on the build plate 113. Incidentally, since the method of forming the material layer ML has already been described with reference to FIG. 4A to FIG. 4D, a detailed description thereof is omitted here.

[0120] Specifically, the control apparatus 2 may control the layer forming apparatus 12 so that the blade 122 moves from the end part AP to the end part BP while contacting the raw material RM supplied (for example, extruded) from the material supply tank 121, as illustrated in FIG. 10A that illustrates the moving blade 122. As a result, as illustrated in FIG. 10B that illustrates the moving blade 122, the partial material layer PML that is the layer of the raw material RM supplied from the material supply tank 121 to the build tank 111 and that constitutes a part of the material layer ML is formed in the build tank 111 (especially, on the build plate 113 in the build tank 111).

[0121] Then, the blade 122 may again move from the end part AP to the end part BP to form a new partial material layer PML on the partial material layer PML that has been already formed, as illustrated in FIG. 10C. Namely, the layer forming apparatus 12 supplies the raw material RM while moving the blade 122 relative to the build plate 113 to form the new partial material layer PML on the partial material layer PML that has been already formed. Here, in the example illustrated in FIG. 4, the build plate 113 is lowered each time the blade 122 moves from the end part AP to the end part BP (namely, the blade 122 forms the partial material layer PML). On the other hand, in the present example embodiment, when the first material layer ML is formed at the step S15, the build plate 113 may not be lowered each time the blade 122 moves from the end part AP to the end part BP (namely, the blade 122 forms the partial material layer PML). In this case, the blade 122 may repeatedly move between the end part AP and the end part BP without lowering the build plate 113 until the thickness of the material layer ML including the plurality of partial material layers PML is equal to the desired target thickness. In this case, the lower surface 1221 of the blade 122 may be located at a height corresponding to the desired target thickness from a surface on which the material layer ML is formed (for example, a surface of the build plate 113). An operation for forming the first material layer ML at the step S15 may be the same as the operation illustrated in FIG. 4 except that the build plate 113 may not be lowered. In this case, as illustrated in FIG. 10D, the lower surface 1221 of the blade 122 contacts an upper surface (namely, a surface facing toward the +Z side) MLs of the material layer ML at a timing at which the thickness of the material layer MLs including the plurality of partial material layers PML is equal to the desired target thickness. As a result, unnecessary raw material RM supplied to the build tank 111 is removed from the material layer ML by the blade 122. Therefore, as illustrated in FIG. 10D, the material layer ML that includes the plurality of partial material layers PML and whose thickness is equal to the desired target thickness is formed in the build tank 111 (especially, on the build plate 113 in the build tank 111).

[0122] The measurement apparatus 14 may measure the material layer ML that has already been formed by the layer forming apparatus 12 (namely, the material layer ML in the process of being formed) in a period during which the layer forming apparatus 12 forms the material layer ML at the step S15. For example, as described above, in order to form the material layer ML, the layer forming apparatus 12 performs a material layer forming process for forming the material layer ML including the plurality of partial material layers PML by repeatedly moving the blade 122 between the end part AP of the material supply tank 121 to the end part BP of the build tank 111. In this case, the measurement apparatus 14 may measure the partial material layer PML newly formed by the layer forming apparatus 12 (namely, the topmost partial material layer PML) each time the layer forming apparatus 12 newly forms the partial material layer PML. Especially, the measurement apparatus 14 may measure the surface of the partial material layer PML newly formed by the layer forming apparatus 12 (namely, the topmost partial material layer PML) each time the layer forming apparatus 12 newly forms the partial material layer PML. In other words, the measurement apparatus 14 may measure the material layer ML including the partial material layer PML newly formed by the layer forming apparatus 12 (namely, the material layer ML that the layer forming apparatus 12 is forming) each time the blade 122 moves from the end part AP to the end part BP. Especially, the measurement apparatus 14 may measure the surface of the material layer ML including the partial material layer PML newly formed by the layer forming apparatus 12 (namely, the material layer ML that the layer forming apparatus 12 is forming) each time the blade 122 moves from the end part AP to the end part BP.

[0123] The control apparatus 2 may determine whether or not the material layer forming process for forming the material layer ML should be ended based on the measured result of the material layer ML by the measurement apparatus 14. Specifically, in a case where the thickness of the material layer ML including the partial material layer PML that has already been formed on the build plate 113 is thinner than the desired target thickness, it is necessary to form a new partial material layer PML on top of the already formed material layer ML to bring the thickness of the already formed material layer ML closer to the target thickness. In this case, the position (alternatively, the three-dimensional shape) of the surface of the already formed material layer ML should change each time the partial material layer PML is newly formed (namely, each time the blade 122 moves from the end part AP to the end part BP). That is, the measured result of the material layer ML by the measurement apparatus 14 should change each time the partial material layer PML is newly formed (namely, each time the blade 122 moves from the end part AP to the end part BP). On the other hand, in a case where the thickness of the material layer ML including the partial material layer PML that has already been formed on the build plate 113 is equal to the desired target thickness, the lower surface 1221 of the blade 122 contacts the upper surface (namely, the surface facing the +Z side) MLs of the material layer ML (see FIG. 10D described above) as described above, and therefore the thickness of the material layer ML that has already been formed in the build tank 111 is kept to be the target thickness. Therefore, the position (alternatively, the three-dimensional shape) of the surface of the already formed material layer ML should remain almost unchanged. Namely, the measured result of the material layer ML by the measurement apparatus 14 should remain almost unchanged.

[0124] Here, when forming a new partial material layer PML on the already formed material layer ML, the layer forming apparatus 12 may change a thickness of the new partial material layer PML formed per one operation of the layer forming apparatus 12 (per one movement of the blade 112). It may become shorting a period of the material layer forming process. When the layer forming apparatus 12 operates multiple times during performing the material layer forming process, a thickness of the partial material layer PLM formed in a first period and a thickness of the partial material layer PLM formed in a second period after the first period may be different from each other. For the example, the thickness of the partial material layer PLM at the first period may be thicker than the thickness of the partial material layer PLM at the second period.

[0125] Therefore, the control apparatus 2 may calculate (namely, acquire) a difference (a measurement difference) between the measured result of the material layer ML by the measurement apparatus 14 at a first time and the measured result of the material layer ML by the measurement apparatus 14 at a second time that is after the first time, and determine whether or not the material layer forming process should be ended by determining whether or not the calculated measurement difference is within a predetermined range.

[0126] The measured result of the material layer ML by the measurement apparatus 14 at the first time may include the measured result acquired by the measurement apparatus 14 measuring a first partial material layer PML after the layer forming apparatus 12 has formed the first partial material layer PML. Namely, the measured result of the material layer ML by the measurement apparatus 14 at the first time may include the measured result acquired by the measurement apparatus 14 measuring the already formed material layer ML including the first partial material layer PML after the layer forming apparatus 12 has formed the first partial material layer PML. However, in a case where the thickness of the already formed material layer ML on the build plate 113 is the desired thickness as described above, the first partial material layer PML is not actually newly formed even if the layer forming apparatus 12 attempts to form the first partial material layer PML. In this case, the measured result of the material layer ML by the measurement apparatus 14 at the first time may substantially include the measured result acquired by the measurement apparatus 14 measuring the material layer ML that the layer forming apparatus 12 is forming after the layer forming apparatus 12 has moved the blade 122 from the end part AP to the end part BP for the purpose of forming the first partial material layer PML.

[0127] On the other hand, the measured result of the material layer ML by the measurement apparatus 14 at the second time may include the measured result acquired by the measurement apparatus 14 measuring a second partial material layer PML after the layer forming apparatus 12 has formed the second partial material layer PML on the first partial material layer PML. Namely, the measured result of the material layer ML by the measurement apparatus 14 at the second time may include the measured result acquired by the measurement apparatus 14 measuring the already formed material layer ML including the second partial material layer PML after the layer forming apparatus 12 has formed the second partial material layer PML on the first partial material layer PML. However, in a case where the thickness of the already formed material layer ML on the build plate 113 is the desired thickness as described above, the second partial material layer PML is not actually newly formed even if the layer forming apparatus 12 attempts to form the second partial material layer PML. In this case, the measured result of the material layer ML by the measurement apparatus 14 at the second time may substantially include the measured result acquired by the measurement apparatus 14 measuring the material layer ML that the layer forming apparatus 12 is forming after the layer forming apparatus 12 has moved the blade 122 from the end part AP to the end part BP for the purpose of forming the second partial material layer PML on the first partial material layer PML.

[0128] In this case, in a case where the measurement difference between the measured result of material layer ML by the measurement apparatus 14 at the first time and the measured result of material layer ML by the measurement apparatus 14 at the second time is within the predetermined range, it is estimated that the position (alternatively, the three-dimensional shape) of the surface of the already formed material layer ML hardly changes. Namely, it is estimated that the material layer ML whose thickness is equal to the target thickness has already been formed on the build plate 113. Therefore, in this case, the control apparatus 2 may determine that the material layer forming process should be ended. Therefore, the control apparatus 2 may end the material layer forming process. On the other hand, in a case where the measurement difference between the measured result of the material layer ML by the measurement apparatus 14 at the first time and the measured result of the material layer ML by the measurement apparatus 14 at the second time is beyond the predetermined range, it is estimated that the position (alternatively, the three-dimensional shape) of the surface of the formed material layer ML changes. Namely, it is estimated that the material layer ML whose thickness is equal to the target thickness has not yet been formed on the build plate 113. Therefore, in this case, the control apparatus 2 may determine that the material layer forming process should not be ended (in other words, the material layer forming process should be continued). Therefore, the control apparatus 2 may not end the material layer forming process. In other words, the control apparatus 2 may continue the material layer forming process.

[0129] Incidentally, the predetermined range may be set in advance so as to satisfy such a condition that “the measurement difference calculated in a situation where the material layer ML whose thickness is equal to the target thickness is formed on the build plate 113 is within the predetermined range”. The predetermined range may be set in advance so as to satisfy such a condition that “the measurement difference calculated in a situation where the material layer ML whose thickness is not equal to the target thickness is formed on the build plate 113 is not included in the predetermined range”.

[0130] Moreover, the control apparatus 2 may determine whether or not the above-described measurement difference is within the predetermined range the determination at a plurality of positions in the surface of the material layer ML.

[0131] However, at a timing at which the operation at the step S15 is performed, the lower surface 1221 of the blade 122 is not necessarily located at the height corresponding to the desired target thickness from the surface on which the material layer ML is formed (for example, the upper surface 1131 of the build plate 113). Therefore, in a case where the lower surface 1221 of the blade 122 is not located at the height corresponding to the target thickness, the lower surface 1221 of the blade 122 contact the upper surface MLs of the material layer ML even in a case where the thickness of the material layer ML, which includes the partial material layer PML that has already been formed on the build plate 113, is not equal to the desired target thickness, and therefore, the measured result of the measurement apparatus 14 remain almost unchanged. Therefore, in a case where the measurement difference is within the predetermined range in this situation, it is estimated that the material layer ML whose thickness is a constant thickness has actually already been formed. Even in this case, the control apparatus 2 may determine that the material layer forming process should be ended. Therefore, the control apparatus 2 may end the material layer forming process. On the other hand, in a case where the measurement difference is beyond the predetermined range, it is estimated that the thickness of the material layer ML on the build plate 113 still increases. Even in this case, the control apparatus 2 may determine that the material layer forming process should not be ended (in other words, the material layer forming process should be continued). Therefore, the control apparatus 2 may not end the material layer forming process. In other words, the control apparatus 2 may continue the material layer forming process.

[0132] The control apparatus 2 may determine whether or not the material layer forming process should be ended based on the measured result of the material layer ML by the measurement apparatus 14 at the first time and a plurality of measured results of material layer ML by the measurement apparatus 14 at a plurality of second times that are after the first time. For example, the control apparatus 2 may determine whether or not the material layer forming process should be ended based on the measurement difference between the measured result of material layer ML by the measurement apparatus 14 at the first time and each of the plurality of measured results of the material layer ML by the measurement apparatus 14 at the plurality of second times. In this case, the control apparatus 2 may calculate a plurality of measurement differences that correspond to the plurality of measured results of the material layer ML by the measurement apparatus 14 at the plurality of second times, respectively. In this case, in a case where all of the plurality of measurement differences are within the predetermined range, it is estimated that the position (alternatively, the three-dimensional shape) of the surface of the already formed material layer ML hardly changes over a relatively long period of time. In this case, it is estimated that there is a high possibility that the material layer ML whose thickness is equal to the target thickness (alternatively, the constant thickness) has been already formed on the build plate 113. Therefore, in this case, the control apparatus 2 may determine that the material layer forming process should be ended. On the other hand, in a case where at least one of the plurality of measurement differences is beyond the predetermined range, it is estimated that the position (alternatively, the three-dimensional shape) of the surface of the already formed material layer ML still changes. Therefore, in this case, the control apparatus 2 may determine that the material layer forming process should not be ended (in other words, the material layer forming process should be continued). Therefore, in a case where the plurality of measured results of the material layer ML by the measurement apparatus 14 at the plurality of second times are used in this manner, the control apparatus 2 can determine whether or not the material layer ML whose thickness is equal to the target thickness (alternatively, the constant thickness) has been already formed on the build plate 113 more accurately, compared to a case where the plurality of measured results of the material layer ML by the measurement apparatus 14 at the plurality of second times are not used.

[0133] Incidentally, determining whether or not the material layer forming process should be based on the measurement difference between the measured result of the material layer ML by the measurement apparatus 14 at the first time and each of the plurality of measured result of the material layer ML by the measurement apparatus 14 at the plurality of second times may be considered to be substantially equivalent to determining whether or not the material layer forming process should be ended based on a measurement difference between the plurality of measured results of the material layer ML by the measurement apparatus 14 at the plurality of second times. This is because, in a case where the measurement differences between the measured result of the material layer ML by the measurement apparatus 14 at the first time and each of the plurality of measured results of the material layer ML by the measurement apparatus 14 at the plurality of second times are within the predetermined range, the measurement difference between the plurality of measured results of the material layer ML by the measurement apparatus 14 at the plurality of second times is also within the predetermined range. Therefore, the control apparatus 2 may calculate the measurement difference between the plurality of measured results of material layer ML by the measurement apparatus 14 at the plurality of second times and determine whether or not the material layer forming process should be ended by determine whether or not the calculated measurement difference is within the predetermined range.

[0134] Moreover, the control apparatus 2 may determine whether or not the plurality of measurement differences described above are within the predetermined range the determination at a plurality of positions in the surface of the material layer ML.

[0135] The control apparatus 2 may calculate, as the measurement difference, a difference of the three-dimensional shape of the material layer ML calculated from the measured result of the material layer ML by the measurement apparatus 14 at the first time and the measured result of the material layer ML by the measurement apparatus 14 at the second time.

[0136] Specifically, for example, the control apparatus 2 may calculate the three-dimensional shape of the surface of the first partial material layer PML based on the measured result of the material layer ML by the measurement apparatus 14 at the first time. However, in a case where the thickness of the material layer ML that has already been formed on the build plate 113 is the desired thickness as described above, the first partial material layer PML is not actually newly formed even if the layer forming apparatus 12 attempts to form the first partial material layer PML. In this case, the three-dimensional shape calculated based on the measured result of the material layer ML by the measurement apparatus 14 at the first time is, in effect, the three-dimensional shape of the surface of the material layer ML that has already been formed at the first time.

[0137] Similarly, for example, the control apparatus 2 may calculate the three-dimensional shape of the surface of the second partial material layer PML based on the measured result of the material layer ML by the measurement apparatus 14 at the second time. However, in a case where the thickness of the material layer ML that has already been formed on the build plate 113 is the desired thickness as described above, the second partial material layer PML is not actually newly formed even if the layer forming apparatus 12 attempts to form the second partial material layer PML. In this case, the three-dimensional shape calculated based on the measured result of the material layer ML by the measurement apparatus 14 at the second time is, in effect, the three-dimensional shape of the surface of the material layer ML that has already been formed at the second time.

[0138] Then, the control apparatus 2 may calculate a first plane that fits the three-dimensional shape of the surface of the first partial material layer PML (namely, the three-dimensional shape of the surface of the material layer ML that has already been formed at the first time). The first plane may be a least-squares plane of the three-dimensional shape of the surface of the first partial material layer PML (namely, the three-dimensional shape of the surface of the material layer ML that has already been formed at the first time). Similarly, the control apparatus 2 may calculate a second plane that fits the three-dimensional shape of the surface of the second partial material layer PML (namely, the three-dimensional shape of the surface of the material layer ML that has already been formed at the second time). The second plane may be a least-squares plane of the three-dimensional shape of the surface of the second partial material layer PML (namely, the three-dimensional shape of the surface of the material layer ML that has already been formed at the second time).

[0139] Then, the control apparatus 2 may use a difference between the first plane and the second plane as the measurement difference. For example, FIG. 11A illustrates an example in which a difference (the measurement difference) between a first plane P11 calculated based on the measured result of the material layer ML by the measurement apparatus 14 at a first time t11 and a second plane P12 calculated based on the measured result of the material layer ML by the measurement apparatus 14 at a second time t12 is beyond the predetermined range. FIG. 11B illustrates an example in which a difference (the measurement difference) between a first plane P21 calculated based on the measured result of the material layer ML by the measurement apparatus 14 at a first time t21 and at least one of a plurality of second planes P22 to P29 calculated based on the plurality of measured results of the material layer ML by the measurement apparatus 14 at a plurality of second times t22 to t29 is beyond the predetermined range. In this case, the control apparatus 2 may determine that the material layer forming process should be continued. On the other hand, FIG. 11C illustrates an example in which a difference (the measurement difference) between a first plane P31 calculated based on the measured result of the material layer ML by the measurement apparatus 14 at a first time t31 and a second plane P32 calculated based on the measured result of the material layer ML by the measurement apparatus 14 at a second time t32 is within the predetermined range. FIG. 11D illustrates an example in which a difference (the measurement difference) between a first plane P41 calculated based on the measured result of the material layer ML by the measurement apparatus 14 at a first time t41 and each of a plurality of second planes P42 to P49 calculated based on the plurality of measured results of the material layer ML by the measurement apparatus 14 at a plurality of second times t42 to t49 is within the predetermined range. In this case, the control apparatus 2 may determine that the material layer forming process should be ended.

[0140] Note that the measured result of the material layer ML by the measurement apparatus 14 used in determining whether or not the material layer forming process should be ended is not limited to a plurality of images for the phase shift method. For example, the result of capturing the image of at least a part of the surface of the material layer ML (the partial material layer PML) by the measuring apparatus 14 may be used as the measured result of the material layer ML by the measurement apparatus 14. In this case, the measurement apparatus 14 may be a camera that captures a two-dimensional image of at least a part of the surface of the material layer ML (the partial material layer PML), and the projection apparatus 141 may not be provided.

[0141] In this case, the control apparatus 2 may determine or classify an area where the material layer ML (the partial material layer PML) is formed and an area where the build plate 113 is exposed (an area where the material layer ML (the partial material layer PML) is not formed yet) by using a difference in light amount values in the two-dimensional images acquired by the measurement apparatus 14. The control apparatus 2 may calculate the size of each classified area, and use the calculated size of each area to determine whether or not the material layer forming process should be ended. Here, in a case where the size of the area where the material layer ML (the partial material layer PML) is formed is larger than a predetermined value, the control apparatus 2 may determine that the material layer forming process should be ended. Incidentally, after it is determined that the size of the area where the material layer ML (the partial material layer PML) is formed is larger than the predetermined value, the blade 122 may be moved between the end part AP of the material supply tank 121 and the end part BP of the build tank 111 for a predetermined cycle, and then the material layer forming process may be ended.

[0142] Moreover, the projection apparatus 141 of the measurement apparatus 14 may not project a bright and dark light pattern. For example, the projection apparatus 141 may project light with substantially uniform illuminance onto the measurement target object. In this case, the projection apparatus 141 may be referred to as an illumination apparatus. Here, the capturing apparatus 142 may not be provided in a direction in which the light from the projection apparatus 141 (the illumination apparatus) is specularly reflected by the measurement target object. For example, the projection apparatus 141 (the illumination apparatus) and the capturing apparatus 142 may be arranged so that an unevenness of the surface of the measurement target object is well reflected in the difference in the light amount in the imaging results of the capturing apparatus 142. In this case, the control apparatus 2 may determine a flatness of the surface of the measurement target object by using the difference in the light amount within the area where the material layer ML (the partial material layer PML) is formed in the two-dimensional image acquired by the measurement apparatus 14. Namely, the control apparatus 2 may use the difference in the light amount within the area where the material layer ML (the partial material layer PML) is formed in the two-dimensional image acquired by the measurement apparatus 14 to determine whether or not the material layer forming process should be ended.

[0143] (2-6) Measurement of Material Layer ML Again In FIG. 6, then, after the material layer ML is formed on the build plate 113 at the step S15, the measurement apparatus 14 measures the material layer ML formed at the step S15 (a step S16).

[0144] At the step S15, the measurement apparatus 14 measures the three-dimensional shape of the material layer ML. Namely, the measurement apparatus 14 measures the positions (for example, the positions or the heights in the Z-axis direction, and the distances from the reference position) of the plurality of parts of the material layer ML. Especially, at the step S16, the measurement apparatus 14 measures the three-dimensional shape of the upper surface MLs of the material layer ML. Namely, the measurement apparatus 14 measures the positions (for example, the positions or the heights in the Z-axis direction, and the distances from the reference position) of the plurality of parts of the upper surface MLs of the material layer ML. The measured result of the material layer ML by the measurement apparatus 14 at the step S16 is outputted to the control apparatus 2. Incidentally, for convenience of description, the measured result of the material layer ML by the measurement apparatus 14 at the step S16 is referred to as a material layer measured result in the below-described description. The control apparatus 2 acquires, from the measurement apparatus 14, the material layer measured result outputted from the measurement apparatus 14. The material layer measured result acquired by the control apparatus 2 is used to control at least one of the layer forming apparatus 12 and the carrier driving system 114 at the step S17 described below. Namely, the material layer measured result acquired by the control apparatus 2 is used to make at least one of the layer forming apparatus 12 and the carrier driving system 114 operate at the step S17 described below. Therefore, an description of an usage of the material layer measured result is omitted here.

[0145] As can be seen from FIG. 6, in the present example embodiment, the measurement apparatus 14 measures the material layer ML at the step S16 after measuring the build plate 113 at the step S14. Namely, the measurement apparatus 14 acquires the material layer measured result by measuring the material layer ML at the step S16 after acquiring the plate measured result by measuring the build plate 113 at the step S14. This is because the measurement apparatus 14 measures the build plate 113 at the step S14 before the material layer ML is formed on the build plate 113 at the step S15, and the measurement apparatus 14 measures the material layer ML at the step S16 after the material layer ML is formed on the build plate 113 at the step S15. Namely, this is because the control apparatus 2 operates the layer forming apparatus 12 to form the material layer ML on the build plate 113 from a time at which the measurement apparatus 14 measures the build plate 113 to acquire the plate measured result at the step S14 to a time at which the measurement apparatus 14 measures the material layer ML to acquire the material layer measured result at the step S16. The reason for this is that the layer forming apparatus 12 is activated to form the material layer ML on the build plate 113.

[0146] However, the measurement apparatus 14 may measure the build plate 113 after the layer forming apparatus 12 starts forming the material layer ML at the step S15. Namely, the measurement apparatus 14 may measure the build plate 113 after the operation at the step S15 is started. In this case, the measurement apparatus 14 may measure the position of a part of the build plate 113 that is not yet covered by the raw material RM for forming the material layer ML. In other words, the measurement apparatus 14 may measure the position of a part of the build plate 113 that is exposed to the outside. Especially, the measurement apparatus 14 may measure the positions of a plurality of parts of the build plate 113 that are not yet covered by the raw material RM for forming the material layer ML. In other words, the measurement apparatus 14 may measure the positions of a plurality of parts of the build plate 113 that are exposed to the outside. As a result, even in a case where the measurement apparatus 14 measures the build plate 113 after the layer forming apparatus 12 starts forming the material layer ML at the step S15, the measurement apparatus 14 can acquire the plate measured result.

[0147] The carrier driving system 114 may not move the build plate 113 from the time at which the measurement apparatus 14 measures the build plate 113 to acquire the plate measured result at the step S14 to the time at which the measurement apparatus 14 measures the material layer ML to acquire the material layer measured result at the step S16. Namely, the carrier driving system 114 may be inactive from the time at which the measurement apparatus 14 measures the build plate 113 to acquire the plate measured result at the step S14 to the time at which the measurement apparatus 14 measures the material layer ML to acquire the material layer measured result at the step S16.

[0148] (2-7) Adjustment of Positional Relationship between Build Plate 113 and Blade 122 Then, the control apparatus 2 controls at least one of the layer forming apparatus 12 and the carrier driving system 114 based on the plate measured result acquired at the step S14 and the material layer measured result acquired at the step S16 (the step S17). Especially, in the present example embodiment, an example in which the control apparatus 2 adjusts a positional relationship between the build plate 113 and the blade 122 by controlling at least one of the layer forming apparatus 12 and the carrier driving system 114 based on the plate measured result acquired at the step S14 and the material layer measured result acquired at the step S16 will be described. Specifically, in the present example embodiment, an example in which the control apparatus 2 adjusts the positional relationship between the build plate 113 and the blade 122 by controlling at least one of the stage apparatus 11 (especially, the carrier driving system 114) that is configured to move the build plate 113 and the layer forming apparatus 12 (especially, the blade driving system 123) that is configured to move the blade 122based on the plate measured result and the material layer measured result.

[0149] Next, an example of an operation for adjusting the positional relationship between the build plate 113 and the blade 122 based on the plate measured result and the material layer measured result will be described.

[0150] (2-7-1) First Example of Adjustment of Positional Relationship between Build Plate 113 and Blade 122 The control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122 so as to satisfy such a first adjustment condition that “the upper surface 1131 of the build plate 113 is parallel to the upper surface MLs of the material layer ML formed on the build plate 113”.

[0151] Here, as described above, the material layer ML is formed by the blade 122 moving while the lower surface 1221 of the blade 122 contacts the raw material RM supplied to the build tank 111. Therefore, as illustrated in FIG. 12A that is a cross-sectional view illustrating the blade 122, the material layer ML, and the build plate 113, the upper surface 1131 of the build plate 113 is parallel to the upper surface MLs of the material layer MLs formed on the build plate 113 in a case where the upper surface 1131 of the build plate 113 is parallel to the lower surface 1221 of the blade 122. On the other hand, as illustrated in FIG. 12B that is a cross-sectional view illustrating the blade 122, the material layer ML, and the build plate 113, the upper surface 1131 of the build plate 113 is not parallel to the upper surface MLs of the material layer MLs formed on the build plate 113 in a case where the upper surface 1131 of the build plate 113 is not parallel to the lower surface 1221 of the blade 122. Incidentally, each of FIG. 12A and FIG. 12B is differs from FIG. 4A to FIG. 4D, each of which illustrates a cross-section along a movement direction of the blade 122, in that each of FIG. 12A and FIG. 12B illustrate a cross-section intersecting the movement direction of the blade 122.

[0152] Therefore, the control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122 based on the plate measured result and the material layer measured result so that the upper surface 1131 of the build plate 113 is parallel to the lower surface 1221 of the blade 122. Namely, an operation for adjusting the positional relationship between the build plate 113 and the blade 122 so as to satisfy the first adjustment condition that “the upper surface 1131 of the build plate 113 is parallel to the upper surface MLs of the material layer ML formed on the build plate 113” may be considered to be equivalent to an operation for adjusting the positional relationship between the build plate 113 and the blade 122 to satisfy such a third adjustment condition that “the upper surface 1131 of the build plate 113 is parallel to the lower surface 1221 of the blade 1221”.

[0153] Specifically, the control apparatus 2 may calculate a position of the build plate 113 in a rotational direction around a predetermined rotation axis based on the plate measured result. Namely, the control apparatus 2 may calculate the attitude of the build plate 113 around the predetermined rotation axis based on the plate measured result. For example, the control apparatus 2 may calculate at least one of the attitude of the build plate 113 around the rotation axis along the X-axis and the attitude of the build plate 113 around the rotation axis along the Y-axis based on the plate measured result.

[0154] Incidentally, in order to calculate the attitude of the build plate 113, the control apparatus 2 may not necessarily calculate the three-dimensional shape of the build plate 113 based on the plate measured result. For example, the control apparatus 2 may calculate the positions of at least two parts of the build plate 113 based on the plate measured result, and calculate the attitude of the build plate 113 based on the measured result of the positions of at least two parts of the build plate 113. In this case, the measurement apparatus 14 may measure the positions of the at least two parts of the build plate 113 to acquire the plate measured result at the step S14. As one example, the control apparatus 2 may calculate the positions (for example, the positions in the Z-axis direction) of at least two parts of the build plate 113 that are distant from each other along the X-axis direction based on the plate measured result, and calculate the attitude of the build plate 113 around the rotation axis along the Y-axis based on the calculated result of the positions of at least two parts of the build plate 113 that are distant from each other along the X-axis direction. As another example, the control apparatus 2 may calculate the positions (for example, the positions in the Z-axis direction) of at least two parts of the build plate 113 that are distant from each other along the Y-axis direction based on the plate measured result, and calculate the attitude of the build plate 113 around the rotation axis along the X-axis based on the calculated result of the positions of at least two parts of the build plate 113 that are distant from each other along the Y-axis direction.

[0155] Similarly, the control apparatus 2 may calculate the attitude of the material layer ML in a rotational direction around a predetermined rotation axis based on the material layer measured result. Namely, the control apparatus 2 may calculate the attitude of the material layer ML around the predetermined rotation axis based on the material layer measured result. For example, the control apparatus 2 may calculate at least one of the attitude of the material layer ML around the rotation axis along the X-axis and the attitude of the material layer ML around the rotation axis along the Y-axis based on the material layer measured result.

[0156] Incidentally, in order to calculate the attitude of the material layer ML, the control apparatus 2 may not necessarily calculate the three-dimensional shape of the material layer ML based on the material layer measured result. For example, the control apparatus 2 may calculate the positions of at least two parts of the material layer ML based on the material layer measured result, and calculate the attitude of the material layer ML based on the measured result of the positions of at least two parts of the material layer ML. In this case, the measurement apparatus 14 may measure the positions of the at least two parts of the material layer ML to acquire the material layer measured result at the step S16. As one example, the control apparatus 2 may calculate the positions (for example, the positions in the Z-axis direction) of at least two parts of the material layer ML that are distant from each other along the X-axis direction based on the material layer measured result, and calculate the attitude of the material layer ML around the rotation axis along the Y-axis based on the calculated result of the positions of at least two parts of the material layer ML that are distant from each other along the X-axis direction. As another example, the control apparatus 2 may calculate the positions (for example, the positions in the Z-axis direction) of at least two parts of the material layer ML that are distant from each other along the Y-axis direction based on the material layer measured result, and calculate the attitude of the material layer ML around the rotation axis along the X-axis based on the calculated result of the positions of at least two parts of the material layer ML that are distant from each other along the Y-axis direction.

[0157] Then, the control apparatus 2 may determine whether or not the upper surface 1131 of the build plate 113 is parallel to the upper surface MLs of the material layer ML based on the calculated result of the attitude of the build plate 113 and the calculated result of the attitude of the material layer ML.

[0158] In a case where the upper surface 1131 of the build plate 113 is parallel to the upper surface MLs of the material layer ML, it is estimated that the upper surface 1131 of the build plate 113 is parallel to the lower surface 1221 of the blade 122. In this case, the control apparatus 2 may not adjust the positional relationship between the build plate 113 and the blade 122.

[0159] On the other hand, in a case where the upper surface 1131 of the build plate 113 is not parallel to the upper surface MLs of the material layer ML, it is estimated that the upper surface 1131 of the build plate 113 is not parallel to the lower surface 1221 of the blade 122. In this case, the control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122 so that the upper surface 1131 of the build plate 113 is parallel to the lower surface 1221 of the blade 122. Specifically, the control apparatus 2 may calculate, based on the calculated result of the attitude of the build plate 113 and the calculated result of the attitude of the material layer ML, an amount of change of the attitude (namely, an amount of change of the position in the rotational direction around the rotation axis) of at least one of the build plate 113 and the material layer ML required to make the upper surface 1131 of the build plate 113 parallel to the upper surface MLs of the material layer ML may be calculated. Then, the control apparatus 2 may change the attitude (namely, the position in the rotational direction around the rotation axis) of at least one of the build plate 113 and the blade 122 by a calculated result of the amount of change of the attitude of at least one of the build plate 113 and the material layer ML. As a result, the upper surface 1131 of the build plate 113 is parallel to the lower surface 1221 of the blade 122.

[0160] As described above, the operation for adjusting the positional relationship between the build plate 113 and the blade 122 so as to satisfy the first adjustment condition may include an operation for adjusting (in other words, changing) a positional relationship between the build plate 113 and the blade 122 in the rotational direction around the predetermined rotation axis. Namely, the operation for adjusting the positional relationship between the build plate 113 and the blade 122 so as to satisfy the first adjustment condition may include an operation for adjusting (in other words, changing) an attitude relationship between the build plate 113 and the blade 122 around the predetermined rotation axis so as to satisfy the first adjustment condition.

[0161] The control apparatus 2 may control the carrier driving system 114 that is configured to move the build plate 113 so that the build plate 113 moves until the upper surface 1131 of the build plate 113 is parallel the lower surface 1221 of the blade 122. Namely, the control apparatus 2 may control the carrier driving system 114 so that the build plate 113 moves relative to the material layer ML and the blade 122 until the upper surface 1131 of the build plate 113 and the lower surface 1221 of the blade 122. In other words, the control apparatus 2 may control the carrier driving system 114 to change the attitude of the build plate 113 until the upper surface 1131 of the build plate 113 is parallel to the lower surface 1221 of the blade 122. Namely, the control apparatus 2 may control the carrier driving system 114 to change the attitude of the build plate 113 relative to the material layer ML and the blade 122 until the upper surface 1131 of the build plate 113 is parallel to the lower surface 1221 of the blade 122.

[0162] As a first example, FIG. 13A illustrates an example in which each of the lower surface 1221 of the blade 122 and the upper surface MLs of the material layer ML is a horizontal surface (namely, a surface along the XY plane) while the upper surface 1131 of the build plate 113 is a surface intersecting the horizontal plane, and as a result, each of the lower surface 1221 of the blade 122 and the upper surface MLs of the material layer ML is not parallel to the upper surface 1131 of the build plate 113. Incidentally, in an example illustrated in FIG. 13A, it may be considered that a positional misalignment of the build plate 113 occurs. At least one of an assembly error of the build plate 113, a thermal deformation of the build plate 113, and an impact applied to the build plate 113 is one example of a reason why the positional misalignment of the build plate 113 occurs. In this case, as illustrated in FIG. 13B, the control apparatus 2 may move the build plate 113 so that the upper surface 1131 of the build plate 113 is the horizontal surface. As a result, the lower surface 1221 of the blade 122 is parallel to the upper surface 1131 of the build plate 113, as illustrated in FIG. 13B.

[0163] As a second example, FIG. 14A illustrates an example in which each of the lower surface 1221 of the blade 122 and the upper surface MLs of the material layer ML is a surface intersecting the horizontal surface while the upper surface 1131 of the build plate 113 is the horizontal surface, and as a result, each of the lower surface 1221 of the blade 122 and the upper surface MLs of the material layer ML is not parallel to upper surface 1331 of the build plate 113. Incidentally, in an example illustrated in FIG. 14A, it may be considered that a positional misalignment of the blade 122 occurs. At least one of an assembly error of the blade 122, a thermal deformation of the blade 122, an impact applied to the blade 122, and a case in which an old and aligned blade has replaced with a new and non-aligned blade is one example of a reason why the positional misalignment of the blade 122 occurs. In this case, as illustrated in FIG. 14B, the control apparatus 2 may move the build plate 113 so that the upper surface 1131 of the build plate 113 is the surface intersecting the horizontal surface. Especially, the control apparatus 2 may move the build plate 113 so that the upper surface 1131 of the build plate 113 is the surface that intersects the horizontal surface and that is parallel to the lower surface 1221 of the blade 122. As a result, the lower surface 1221 of the blade 122 is parallel to the upper surface 1131 of the build plate 113, as illustrated in FIG. 14B.

[0164] The control apparatus 2 may control the blade driving system 123 that is configured to move the blade 122 so that the blade 122 moves until the upper surface 1131 of the build plate 113 is parallel the lower surface 1221 of the blade 122, in addition to or instead of controlling the carrier driving system 114 so that the build plate 113 moves until the upper surface 1131 of the build plate 113 is parallel to the lower surface 1221 of the blade 122. Namely, the control apparatus 2 may control the blade driving system 123 so that the blade 122 moves relative to the build plate 113 until the upper surface 1131 of the build plate 113 and the lower surface 1221 of the blade 122. In other words, the control apparatus 2 may control the blade driving system 123 to change the attitude of the blade 122 until the upper surface 1131 of the build plate 113 is parallel to the lower surface 1221 of the blade 122. Namely, the control apparatus 2 may control the blade driving system 123 to change the attitude of the blade 122 relative to the build plate 113 until the upper surface 1131 of the build plate 113 is parallel to the lower surface 1221 of the blade 122.

[0165] As a first example, FIG. 15A illustrates an example in which each of the lower surface 1221 of the blade 122 and the upper surface MLs of the material layer ML is the horizontal surface (namely, the surface along the XY plane) while the upper surface 1131 of the build plate 113 is the surface intersecting the horizontal plane, and as a result, each of the lower surface 1221 of the blade 122 and the upper surface MLs of the material layer ML is not parallel to the upper surface 1131 of the build plate 113. In this case, as illustrated in FIG. 15B, the control apparatus 2 may move the blade 122 so that the lower surface 1221 of the blade 122 is the surface intersecting the horizontal surface. Especially, the control apparatus 2 may move the blade 122 so that the lower surface 1221 of the blade 122 is the surface that intersects the horizontal surface and that is parallel to the upper surface 1131 of the build plate 113. As a result, the lower surface 1221 of the blade 122 is parallel to the upper surface 1131 of the build plate 113, as illustrated in FIG. 15B.

[0166] As a second example, FIG. 16A illustrates an example in which each of the lower surface 1221 of the blade 122 and the upper surface MLs of the material layer ML is the surface intersecting the horizontal surface while the upper surface 1131 of the build plate 113 is the horizontal surface, and as a result, each of the lower surface 1221 of the blade 122 and the upper surface MLs of the material layer ML is not parallel to upper surface 1331 of the build plate 113. In this case, as illustrated in FIG. 16B, the control apparatus 2 may move the blade 122 so that the lower surface 1221 of the blade 122 is the horizontal surface. As a result, the lower surface 1221 of the blade 122 is parallel to the upper surface 1131 of the build plate 113, as illustrated in FIG. 16B.

[0167] Incidentally, although it is not illustrated in the drawings, there is a possibility that each of the lower surface 1221 of the blade 122 and the upper surface MLs of the material layer ML is not parallel to the upper surface 1131 of the build plate 113 in a situation where each of the lower surface 1221 of the blade 122, the upper surface MLs of the material layer ML, and the upper surface 1131 of the build plate 113 intersects the horizontal surface. In this case, the control apparatus 2 may move at least one of the build plate 113 and the blade 122 so that the lower surface 1221 of the blade 122 is parallel to the upper surface 1131 of the build plate 113.

[0168] The control apparatus 2 may move the blade 122 between the end part AP of the material supply tank 121 and the end part BP of the build tank 111 after moving at least one of the build plate 113 and the blade 122 so that the lower surface 1221 of the blade 122 is parallel to the upper surface 1131 of the build plate 113. As a result, the material layer ML is shaped by the blade 122 even in a case where the material layer ML has collapsed due to the movement of at least one of the build plate 113 and the blade 122. As a result, the upper surface 1131 of the build plate 113 is parallel to the upper surface MLs of the material layer ML formed on the build plate 113.

[0169] (2-7-2) Second Example of Adjustment of Positional Relationship between Build Plate 113 and Blade 122 The control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122 so as to satisfy such a second adjustment condition that “the thickness of the material layer ML formed on the build plate 113 is equal to the desired target thickness, in addition to or instead of satisfying the above-described first adjustment condition. In other words, the control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122 so as to satisfy such a second adjustment condition that “the layer forming apparatus 12 is capable of forming the material layer ML whose thickness is equal to the desired target thickness on the build plate 113.

[0170] Specifically, the thickness of the material layer ML formed on the build plate 113 depends on the height of the lower surface 1221 of the blade 122 from the surface on which the material layer ML is formed (for example, the upper surface 1131 of the build plate 113). Namely, the thickness of the material layer ML formed on the build plate 113 depends on a distance (specifically, a distance in the Z-axis direction) between the surface on which the material layer ML is formed (for example, the upper surface 1131 of the build plate 113) and the lower surface 1221 of the blade 122. This is because the thickness of the material layer ML formed on the build plate 113 increases until the lower surface 1221 of the blade 122 contacts the upper surface MLs of the material layer ML. Then, after the lower surface 1221 of the blade 122 contacts the upper surface MLs of the material layer ML, the material layer ML formed on the build plate 113 is maintained constant. Therefore, the material layer ML whose thickness is equal to the distance between the upper surface 1131 of the build plate 113 and the lower surface 1221 of the blade 122 is formed on the build plate 113.

[0171] Therefore, the control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122 based on the plate measured result and the material layer measured result so that the distance (namely, the distance in the Z-axis direction, the same may be applied to the below-described description) between the upper surface 1131 of the build plate 113 and the lower surface 1221 of the blade 122 is equal to the target thickness of the material layer ML to be formed on the build plate 113.

[0172] Specifically, the control apparatus 2 may calculate the position of the build plate 113 in the Z-axis direction based on the plate measured result. Furthermore, the control apparatus 2 may calculate the position of the material layer ML in the Z-axis direction based on the material layer measured result.

[0173] Incidentally, in order to calculate the position of the build plate 113 in the Z-axis direction, the control apparatus 2 may not necessarily calculate the three-dimensional shape of the build plate 113 based on the plate measured result. For example, the control apparatus 2 may calculate the position of at least one part of the build plate 113 in the Z-axis direction based on the plate measured result, and use the calculated position as the position of the build plate 113 in the Z-axis direction. In this case, the measurement apparatus 14 may measure the position of at least one part of the build plate 113 to acquire the plate measured result at the step S14 in FIG. 6. Similarly, in order to calculate the position of the material layer ML in the Z-axis direction, the control apparatus 2 may not necessarily calculate the three-dimensional shape of the material layer ML based on the material layer measured result. For example, the control apparatus 2 may calculate the position of at least one part of the material layer ML in the Z-axis direction based on the material layer measured result, and use the calculated position as the position of the material layer ML in the Z-axis direction. In this case, the measurement apparatus 14 may measure the position of at least one part of the material layer ML to acquire the material layer measured result at the step S16 in FIG. 6.

[0174] Incidentally, in order to adjust the positional relationship between the build plate 113 and the blade 122 to satisfy not only the second adjustment condition but also the above-described first adjustment condition, the control apparatus 2 may calculate at least one of the attitude of the build plate 113 around the rotation axis along the X-axis and the attitude of the build plate 113 around the rotation axis along the Y-axis as described above, in addition to the position of the build plate 113 in the Z-axis direction. In this case, the control apparatus 2 may calculate at least one of the position of the build plate 113 in the Z-axis direction, the attitude of the build plate 113 around the rotation axis along the X-axis, and the attitude of the build plate 113 around the rotation axis along the Y-axis by calculating the positions of at least three parts of the build plate 113 in the Z-axis direction based on the plate measured result. In this case, the measurement apparatus 14 may measure the positions of at least three parts of the build plate 113 at the step S14 in FIG. 6 to acquire the plate measured result.

[0175] Similarly, in order to adjust the positional relationship between the build plate 113 and the blade 122 to satisfy not only the second adjustment condition but also the above-described first adjustment condition, the control apparatus 2 may calculate at least one of the attitude of the material layer ML around the rotation axis along the X-axis and the attitude of the material layer ML around the rotation axis along the Y-axis as described above, in addition to the position of the material layer ML in the Z-axis direction. In this case, the control apparatus 2 may calculate at least one of the position of the material layer ML in the Z-axis direction, the attitude of the material layer ML around the rotation axis along the X-axis, and the attitude of the material layer ML around the rotation axis along the Y-axis by calculating the positions of at least three parts of the material layer ML in the Z-axis direction based on the material layer measured result. In this case, the measurement apparatus 14 may measure the positions of at least three parts of the material layer ML at the step S16 in FIG. 6 to acquire the material layer measured result.

[0176] Then, the control apparatus 2 may calculate, as the thickness of the material layer ML, the distance between the upper surface 1131 of the build plate 113 and the upper surface MLs of the material layer ML in the Z-axis direction based on the calculated result of the position of the build plate 113 in the Z-axis direction and the calculated result of the position of the material layer ML in the Z-axis direction.

[0177] Here, in a case where the calculated thickness of the material layer ML is equal to the target thickness, it is estimated that the distance between the upper surface 1131 of the build plate 113 and the lower surface 1221 of the blade 122 is also equal to the target thickness. In this case, the control apparatus 2 may not adjust the positional relationship between the build plate 113 and the blade 122.

[0178] On the other hand, in a case where the calculated thickness of the material layer ML is not equal to the target thickness, it is estimated that the distance between the upper surface 1131 of the build plate 113 and the lower surface 1221 of the blade 122 is also not equal to the target thickness. In this case, the control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122. Specifically, the control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122 in the Z-axis direction so that the distance between the upper surface 1131 of the build plate 113 and the lower surface 1221 of the blade 122 is equal to the target thickness. For example, the control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122 in the Z-axis direction so that the positional relationship between the build plate 113 and the blade 122 is changed by a distance corresponding to a difference between the calculated thickness of the material layer ML and the target thickness. As one example, the control apparatus 2 may control the carrier driving system 114 so that the build plate 113 moves in the Z-axis direction by the distance corresponding to the difference between the calculated thickness of the material layer ML and the target thickness. As another example, the control apparatus 2 may control the blade driving system 123 so that the blade 122 moves in the Z-axis direction by the distance corresponding to the difference between the calculated thickness of the material layer ML and the target thickness.

[0179] The control apparatus 2 may move the blade 122 between the end part AP of the material supply tank 121 and the end part BP of the build tank 111 after moving at least one of the build plate 113 and the blade 122 so that the distance between the lower surface 1221 of the blade 122 and the upper surface 1131 of the build plate 113 is equal to the target thickness. As a result, the material layer ML is shaped by the blade 122 even in a case where the material layer ML has collapsed due to the movement of at least one of the build plate 113 and the blade 122. As a result, the material layer ML whose thickness is the target thickness is formed on the build plate 113.

[0180] Incidentally, in a case where the positional relationship between the build plate 113 and the blade 122 has not been adjusted to satisfy the first adjustment condition, there is a possibility that the upper surface 1131 of the build plate 113 is not parallel to the upper surface MLs of the material layer ML formed on the build plate 113, as illustrated in FIG. 12B described above. As a result, as illustrated in FIG. 12B described above, there is a possibility that the thickness of the material layer ML formed on the build plate 113 is uneven. In such a situation where the thickness of the material layer ML formed on the build plate 113 is uneven, there is a possibility that the control apparatus 2 cannot accurately calculate the thickness of the material layer ML. Therefore, the control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122 to satisfy the second adjustment condition after adjusting the positional relationship between the build plate 113 and the blade 122 to satisfy the first adjustment condition. However, the control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122 to satisfy the second adjustment condition before adjusting the positional relationship between the build plate 113 and the blade 122 to satisfy the first adjustment condition. The control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122 to satisfy the second adjustment condition without adjusting the positional relationship between the build plate 113 and the blade 122 to satisfy the first adjustment condition.

[0181] (2-8) Building of Three-Dimensional Build Object Then, the control apparatus 2 controls the build apparatus 1 to build the three-dimensional build object (a step S18). Specifically, the control apparatus 2 may control the build apparatus 1 to build the structural layer SL by irradiating the build material layer ML formed on the build plate 113 at the step S15 with the build light BL. Then, the control apparatus 2 may control the build apparatus 1 to alternately repeat the operation for forming a new material layer ML and the operation for building a new structural layer SL by irradiating the newly formed material layer ML with the build light BL. As a result, the three-dimensional build object including the plurality of structural layers SL is built.

[0182] (3) Technical Effect of Build System SYS As described above, in the present example embodiment, the control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122 at the step S17 in FIG. 6. As a result, compared to a case where the positional relationship between the build plate 113 and the blade 122 is not adjusted, the build system SYS can build the three-dimensional build object properly.

[0183] For example, in a case where the upper surface 1131 of the build plate 113 is not parallel to the upper surface MLs of the material layer ML formed on the build plate 113, there is a possibility that the thickness of the first material layer ML is uneven as illustrated in FIG. 13A, FIG. 14A, FIG. 15A, and FIG. 16A. In this case, there is a possibility that the build structural layer SL is separated from the upper surface 1131 of the build plate 113. As a result, there is a possibility that the building of the three-dimensional build object cannot be completed or the build accuracy of the three-dimensional build object deteriorates. In the present example embodiment, however, the control apparatus 2 may adjust the positional relationship between the build plate 113 and the blades 122 so as to satisfy the first adjustment condition that “the upper surface 1131 of the build plate 113 is parallel to the upper surface MLs of the material layer ML formed on the build plate 113” at the step S17 in FIG. 6 as described above. As a result, the thickness of the first material layer ML is even as illustrated in FIG. 13B, FIG. 14B, FIG. 15B, and FIG. 16B. As a result, there is a low possibility that the building of the three-dimensional build object is terminated in the middle or the build accuracy of the three-dimensional build object deteriorates.

[0184] For example, if the thickness of the material layer ML formed on the build plate 113 is too thin, there is a possibility that the already built structural layer SL located under the material layer ML or the old material layer that has not been used to build the structural layer SL is irradiated with the build light BL. As a result, there is a possibility that the already built structural layer SL is molten, or the old material layer ML that should not be molten is molten thereby the structural layer SL that should not be built is built. As a result, there is a possibility that the build accuracy of the three-dimensional build object deteriorates. On the other hand, for example, if the thickness of the material layer ML formed on the build plate 113 is too thick, there is a possibility that an energy transmitted to the material layer ML from the build light BL with which the material layer ML is irradiated is not transmitted to a lower part of the material layer ML. As a result, there is a possibility that a part of the material layer ML that should be molten is not molten. As a result, there is a possibility that the build accuracy of the three-dimensional build object deteriorates. In the present example embodiment, however, the control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122 so as to satisfy the second adjustment condition that “the thickness of the material layer ML formed on the build plate 113 is equal to the desired target thickness” at the step S17 in FIG. 6 as described above. Therefore, the technical problem described here does not occur. Namely, there is a low possibility that the build accuracy of the three-dimensional build object deteriorates. Therefore, the build system SYS can build the three-dimensional build object with high accuracy.

[0185] Furthermore, in the present example embodiment, the control apparatus 2 uses the plate measured result and the material layer measured result to adjust the positional relationship between the build plate 113 and the blade 122 at the step S17 in FIG. 6. Therefore, the control apparatus 2 can automatically adjust the positional relationship between the build plate 113 and the blade 122 without requiring an instruction from the operator of the build system SYS. Here, in a case where the operator of the build system SYS adjusts the positional relationship between the build plate 113 and the blade 122, there is a possibility that an accuracy of the adjustment of the positional relationship between the build plate 113 and the blade 122 varies depending on a skill level of the operator. As a result, there is a possibility that the build accuracy of the three-dimensional build object varies. In the present example embodiment, however, the control apparatus 2 can adjust the positional relationship between the build plate 113 and the blade 122 without depending on the skill level of the operator. Therefore, there is a low possibility that the accuracy of the adjustment of the positional relationship between the build plate 113 and the blade 122 varies. Therefore, the build system SYS can build the three-dimensional build object with high accuracy.

[0186] Furthermore, at the step S15 in FIG. 6, in the present example embodiment, the control apparatus 2 may determine whether or not the material layer forming process for forming the material layer ML should be ended based on the measured result by the measurement apparatus 14. Therefore, the control apparatus 2 can automatically determine whether or not the material layer forming process should be ended without requiring an instruction from the operator of the build system SYS.

[0187] (4) Modified Example Next, a modified example of the build system SYS will be described. Incidentally, at least two of the modified examples described below may be combined with each other. For example, in the below-described description, a first modified example to a fifth modified example are described. In this case, at least one of the first modified example to the fifth modified example may be combined with at least another one of the first modified example to the fifth modified example.

[0188] (4-1) First Modified Example In the first modified example, as illustrated in FIG. 17 that is a plan view illustrating the projection pattern projected by the projection apparatus 141 of the measurement apparatus 14, the projection apparatus 141 may project a projection pattern across the build plate 113 and the build tank 111 (especially, the side wall 111) that is disposed around the build plate 113. Especially, as illustrated in FIG. 17, the projection apparatus 141 may project a projection pattern across the upper surface 1131 of the build plate 113 and the upper surface 1112 of the build tank 111 (especially, the side wall 111). Incidentally, in the below-described description, the projection pattern across the build plate 113 and the build tank 111 (especially, the side wall 111) is referred to as the projection pattern PP.

[0189] Furthermore, the capturing apparatus 142 of the measurement apparatus 14 may capture the image of the projection pattern PP across the build plate 113 and the build tank 111. Especially, the capturing apparatus 142 may capture the image of the upper surface 1131 of the build plate 113 and the upper surface 1112 of the build tank 111 on which the projection pattern PP across the build plate 113 and the build tank 111 is projected.

[0190] In this case, the measured result of the measurement apparatus 14 (namely, the image in which the projection pattern PP across the build plate 113 and the build tank 111 is captured) may be used to perform at least one of the rough alignment operation at the step S12 in FIG. 6 and the fine alignment operation at the step S13 in FIG. 6. Specifically, the control apparatus 2 may calculate the difference (a height difference) Δz between the height of the upper surface 1131 of the build plate 113 and the height of the upper surface 1112 of the build tank 111 based on the image in which the projection pattern PP across the build plate 113 and the build tank 111 is captured.

[0191] As a first example of a method for calculating the height difference ΔZ based on the image in which the projection pattern PP across the build plate 113 and the build tank 111 is captured, the control apparatus 2 may calculate the height difference ΔZ based on a positional relationship between a first pattern part PP1 of the projection pattern PP projected on the build plate 113 and a second pattern part PP2 of the projection pattern PP projected on the build tank 111 in the image that is the measured result by the measurement apparatus 14.

[0192] For example, in a case where the upper surface 1131 of the build plate 113 and the upper surface 1112 of the build tank 111 are located in the same plane (namely, the height difference Δz is zero), the first pattern part PP1 and the second pattern part PP2 are not displaced from each other. Specifically, as illustrated in FIG. 18A that illustrates the image acquired as the measured result by the measurement apparatus 14 in a case where the upper surface 1131 of the build plate 113 and the upper surface 1112 of the build tank 111 are located in the same plane (namely, the height difference Δz is zero), the first pattern part PP1 and the second pattern part PP2 form a single pattern in which the first pattern part PP1 and the second pattern part PP2 are smoothly connected at a border between the build plate 113 and the build tank 111.

[0193] On the other hand, in a case where the upper surface 1131 of the build plate 113 and the upper surface 1112 of the build tank 111 are located in different planes (namely, the height difference Δz is not zero), the first pattern part PP1 and the second pattern part PP2 are displaced from each other. Specifically, as illustrated in FIG. 18B that illustrates the image acquired as the measured result by the measurement apparatus 14 in a case where the upper surface 1131 of the build plate 113 and the upper surface 1112 of the build tank 111 are located in the different planes (namely, the height difference Δz is not zero), the first pattern part PP1 and second pattern part PP2 form a patten in which the first pattern part PP1 and the second pattern part PP2 are connected while they are displaced from each other by a predetermined pattern displacement amount ΔPP at the border between the build plate 113 and the build tank 111. This pattern displacement amount ΔPP varies depending on the height difference Δz. For example, the pattern shift amount ΔPP is larger as the height difference Δz is larger.

[0194] Therefore, the control apparatus 2 may calculate the pattern displacement amount ΔPP between the first pattern part PP1 and the second pattern part PP2 based on the measured result by the measurement apparatus 14. Then, the control apparatus 2 may calculate the height difference ΔZ based on the calculated pattern displacement amount ΔPP. For example, the control apparatus 2 may calculate the height difference Δz from the pattern displacement amount ΔPP based on a predetermined relationship information indicating a relationship between the pattern displacement amount ΔPP and the height difference Δz. Incidentally, the predetermined relational information indicating the relationship between the pattern displacement amount ΔPP and the height difference Δz may be generated in advance.

[0195] In a case where the pattern displacement amount ΔPP is calculated, the projection apparatus 141 may project the projection pattern PP from a direction that is oblique relative to the build plate 113 and the build tank 111. For example, the projection apparatus 141 may project the projection pattern PP from a direction that is inclined with respect to the upper surface 1131 of the build plate 113 and the upper surface 1112 of the build tank 111. As a result, the displacement between the first pattern part PP1 and the second pattern part PP2 is larger, compared to a case where the projection apparatus 141 projects the projection pattern PP from a direction that is directly above the build plate 113 and the build tank 111. Therefore, the control apparatus 2 can easily calculate the pattern displacement amount ΔPP from the image.

[0196] As a second example of the method for calculating the height difference ΔZ based on the image in which the projection pattern PP across the build plate 113 and the build tank 111 is captured, the control apparatus 2 may calculate the position of the build plate 113 based on the first pattern part PP1 of the projection pattern PP projected on the build plate 113. Furthermore, the control apparatus 2 may calculate the position of the build tank 111 based on the second pattern part PP2 of the projection pattern PP projected on the build tank 111. Incidentally, since the method for calculating the position of the measurement target object based on the image on which the projection pattern PP is captured has already been described, a detailed description of this method is omitted. Then, the control apparatus 2 may calculate the height difference Δz based on the calculated result of the position of the build plate 113 and the calculated result of the position of the build tank 111.

[0197] After the height difference Δz is calculated, the control apparatus 2 may perform at least one of the rough alignment operation and the fine alignment operation based on the height difference Δz as described above. For example, the control apparatus 2 may perform at least one of the rough alignment operation and the fine alignment operation so as to satisfy the third alignment condition that “the height difference Δz is equal to or smaller than the predetermined allowable height threshold value”. Namely, the control apparatus 2 may adjust the position of the build plate 113 so as to satisfy the third alignment condition that “the height difference Δz is equal to or smaller than the predetermined allowable height threshold value”.

[0198] (4-2) Second Modified Example In the second modified example, the measurement apparatus 14 may measure the position (the three-dimensional shape) of the build plate 113 by projecting the projection pattern on the build plate 113 in order to perform at least one of the rough alignment operation and the fine alignment operation described above. Then, the control apparatus 2 may calculate (estimate) the position (the three-dimensional shape) of the build tank 111 (especially, the side wall 111) that is disposed around the build plate 113 based on the measured result of the position (the three-dimensional shape) of the build plate 113 by the measurement apparatus 14. For example, the control apparatus 2 may calculate the position (the three-dimensional shape) of the build plate 113 based on the measured result of the position (the three-dimensional shape) of the build plate 113 by the measurement apparatus 14. Then, the control apparatus 2 may calculate (estimate) the position (the three-dimensional shape) of the build tank 111 by interpolating the calculated result of the position (the three-dimensional shape) of the build plate 113. For example, since the build tank 111 is disposed around the build plate 113, the control apparatus 2 may calculate the position of the build tank 111 by extrapolating the calculated result of the position of the build plate 113 as illustrated in FIG. 19.

[0199] Then, the control apparatus 2 may perform at least one of the rough alignment operation and the fine alignment operation based on the calculated result of the position of the build plate 113 and the calculated result of the position of the build tank 111. For example, the control apparatus 2 may calculate the difference (the height difference) Δz between the height of the upper surface 1131 of the build plate 113 and the height of the upper surface 1112 of the build tank 111 based on the calculated result of the position of the build plate 113 and the calculated result of the position of the build tank 111. Then, the control apparatus 2 may perform at least one of the rough alignment operation and the fine alignment operation based on the height difference Δz as described above. For example, the control apparatus 2 may perform at least one of the rough alignment operation and the fine alignment operation so as to satisfy the third alignment condition that “the height difference Δz is equal to or smaller than the predetermined allowable height threshold value”. Namely, the control apparatus 2 may adjust the position of the build plate 113 so as to satisfy the third alignment condition that “the height difference Δz is equal to or smaller than the predetermined allowable height threshold value”.

[0200] (4-3) Third Modified Example In the third modified example, the build system SYS may perform the build operation illustrated in FIG. 20 instead of the build operation illustrated in FIG. 6. FIG. 20 is a flowchart that illustrates a flow of the build operation in the third modified example. Incidentally, in FIG. 20, a detailed description of the operations that has already been described is omitted by assigning the same step number thereto.

[0201] As illustrated in FIG. 20, even in the third modified example, the build system SYS performs the operations from the step S11 to the step S14. Namely, the build plate 113 is placed on the carrier 112 (the step S11), the control apparatus 2 performs the rough alignment operation and the fine alignment operation (the step S12 to the step S13), and the measurement apparatus 14 measures the build plate 113 (the step S14).

[0202] Then, in the third modified example, the control apparatus 2 determines whether or not the upper surface 1131 of the build plate 113 protrudes from the upper surface 1112 of the build tank 111 based on the measured result of the build plate 113 by the measurement apparatus 14 at the step S14 (a step S21). For example, the control apparatus 2 may calculate a protrusion amount PD of the upper surface 1131 of the build plate 113 from the upper surface 1112 of the build tank 111 based on the measured result of the build plate 113 by the measurement apparatus 14 at the step S14. Incidentally, since the protrusion amount PD has already been described with reference to FIG. 9, a detailed description thereof is omitted here. Then, the control apparatus 2 may determine that the upper surface 1131 of the build plate 113 protrudes from the upper surface 1112 of the build tank 111 in a case where the calculated protrusion amount PD is larger than zero. On the other hand, the control apparatus 2 may determine that the upper surface 1131 of the build plate 113 does not protrude from the upper surface 1112 of the build tank 111 in a case where the calculated protrusion amount PD is equal to or smaller than zero.

[0203] As a result of the determination at the step S21, in a case where it is determined that the upper surface 1131 of the build plate 113 protrudes from the upper surface 1112 of the build tank 111 (the step S21: Yes), the control apparatus 2 may perform the fine alignment operation in the step S13 again (the step S13). For example, the control apparatus 2 may adjust the position of the build plate 113 so that the protrusion amount PD is equal to or smaller than zero based on the measured result of the build plate 113 by the measurement apparatus 14 at the step S14. For example, the control apparatus 2 may adjust the position of the build plate 113 until the upper surface 1131 of the build plate 113 no longer protrudes from the upper surface 1112 of the build tank 111 based on the measured result of the build plate 113 by the measurement apparatus 14 at the step S14. Then, the measurement apparatus 14 measures the build plate 113 again (the step S14), and the control apparatus 2 determines whether or not the upper surface 1131 of the build plate 113 protrudes from the upper surface 1112 of the build tank 111 based on the measured result of the build plate 113 by the measurement apparatus 14 at the step S14 again (the step S21).

[0204] On the other hand, as a result of the judgment at the step S21, in a case where it is determined that the upper surface 1131 of the build plate 113 does not protrude from the upper surface 1112 of the build tank 111 (the step S21: No), the control apparatus 2 performs the operations from step the S15 to the step S18. Namely, the control apparatus 2 controls the layer forming apparatus 12 to form the material layer ML on the build plate 113 (the step S15), the measurement apparatus 14 measures the material layer ML (the step S16), the control apparatus 2 adjusts the positional relationship between the build plate 113 and the blade 122 (the step S17), and the control apparatus 2 controls the build apparatus 1 to build the three-dimensional build object (the step S18).

[0205] As described above, in the third modified example, the control apparatus 2 controls the build apparatus 1 to start forming the material layer ML at the step S15 in a case where it is determined at the step S21 that the upper surface 1131 of the build plate 113 does not protrude from the upper surface 1112 of the build tank 111. On the other hand, the control apparatus 2 controls the build apparatus 1 not to start forming the material layer ML at the step S15 in a case where it is determined at the step S21 that the upper surface 1131 of the build plate 113 protrudes from the upper surface 1112 of the build tank 111. As a result, there is a low or no possibility that the blade 122 moving to form the material layer ML at the step S15 collides with the build plate 113.

[0206] (4-4) Fourth Modified Example In the fourth modified example, the build system SYS may perform the build operation illustrated in FIG. 21 instead of the build operation illustrated in FIG. 6. FIG. 21 is a flowchart that illustrates a flow of the build operation in the fourth modified example. Incidentally, in FIG. 21, a detailed description of the operations that has already been described is omitted by assigning the same step number thereto.

[0207] As illustrated in FIG. 21, even in the fourth modified example, the build system SYS performs the operations from the step S11 to the step S17. Namely, t Namely, the build plate 113 is placed on the carrier 112 (the step S11), the control apparatus 2 performs the rough alignment operation and the fine alignment operation (the step S12 to the step S13), the measurement apparatus 14 measures the build plate 113 (the step S14), the control apparatus 2 controls the layer forming apparatus 12 to form the material layer ML on the build plate 113 (the step S15), the measurement apparatus 14 measures the material layer ML (the step S16), the control apparatus 2 adjusts the positional relationship between the build plate 113 and the blade 122 (the step S17).

[0208] Then, the control apparatus 2 controls the build apparatus 1 to remove the material layer ML, which has been formed on the build plate 113 at the step S15, from the build plate 113 (a step S31). For example, in a case where the build apparatus 1 includes a collection apparatus that is configured to collect the raw material RM included in the material layer ML, the control apparatus 2 may control the collection apparatus of the build apparatus 1 to remove (collect) the material layer ML.

[0209] The control apparatus 2 may control the build apparatus 1 to remove whole of the material layer ML from the build plate 113. Alternatively, the control apparatus 2 may control the build apparatus 1 to remove a part of the material layer ML from the build plate 113. In both cases, the control apparatus 2 may control the build apparatus 1 so that at least a part of the build plate 113 is exposed to the outside by removing at least a part of the build material layer ML.

[0210] Incidentally, in an example illustrated in FIG. 21, the control apparatus 2 controls the build apparatus 1 to remove the material layer ML after adjusting the positional relationship between the build plate 113 and the blade 122 at the step S17. However, the control apparatus 2 may control the build apparatus 1 to remove the material layer ML before adjusting the positional relationship between the build plate 113 and the blade 122 at the step S17. Alternatively, the control apparatus 2 may control the build apparatus 1 to remove the material layer ML in a period during which the positional relationship between the build plate 113 and the blade 122 is adjusted at the step S17. The control apparatus 2 may control the build apparatus 1 to remove the material layer ML at any timing after the measurement apparatus 14 measures the material layer ML at the step S16.

[0211] Then, the measurement apparatus 14 measures the build plate 113 (a step S32). Namely, the measurement apparatus 14 measures at least a part of the build plate 113 that is exposed to the outside due to the removal of at least a part of the material layer ML. Incidentally, the operation at the step 32 itself may be the same as the operation at the step S14, and therefore, a detailed description thereof is omitted.

[0212] Then, the control apparatus 2 determines based on the measured result of the build plate 113 by the measurement apparatus 14 at the step S32 whether or not the positional relationship between the build plate 113 and the blade 122 has been properly adjusted at the step S17 (a step S33).

[0213] As a first example, the control apparatus 2 may calculate the attitude (for example, at least one of the attitude around the rotation axis along the X-axis and the attitude around the rotation axis along the Y-axis) of the build plate 113 based on the measured result of the build plate 113 by the measurement apparatus 14 at the step S32. Then, the control apparatus 2 may determine whether or not the calculated attitude is the same as the target that is expected in a case where the positional relationship between the build plate 113 and the blade 122 has been properly adjusted at the step S17. In a case where the calculated attitude is the same as the target attitude, the control apparatus 2 may determine that the positional relationship between the build plate 113 and the blade 122 has been properly adjusted at the step S17. On the other hand, in a case where the calculated attitude is different from the target attitude, the control apparatus 2 may determine that the positional relationship between the build plate 113 and the blade 122 has not been properly adjusted at the step S17.

[0214] As a second example, the control apparatus 2 may calculate the position (for example, the position in the Z-axis direction) of the build plate 113 based on the measured result of the build plate 113 by the measurement apparatus 14 at the step S32. Then, the control apparatus 2 may determine whether or not the calculated position is the same as the target position that is expected in a case where the positional relationship between the build plate 113 and the blade 122 is properly adjusted at the step S17. In a case where the calculated position is the same as the target position, the control apparatus 2 may determine that the positional relationship between the build plate 113 and the blade 122 has been properly adjusted at the step S17. On the other hand, in a case where the calculated position is different from the target position, the control apparatus 2 may determine that the positional relationship between the build plate 113 and the blade 122 has not been properly adjusted at the step S17.

[0215] As a result of the determination at the step S33, in a case where it is determined that the positional relationship between the build plate 113 and the blade 122 has not been properly adjusted at the step S17 (the step S33: No), the control apparatus 2 adjusts the positional relationship between the build plate 113 and the blade 122 again (the step S17). In this case, the control apparatus 2 may use, as the plate measured result, the measured result of the build plate 113 by the measurement apparatus 14 at the step S32.

[0216] On the other hand, as a result of the determination at the step S33, in a case where it is determined that the positional relationship between the build plate 113 and the blade 122 has been properly adjusted at the step S17 (the step S33: Yes), the control apparatus 2 controls the build apparatus 1 to build the three-dimensional molding object (the step S18.

[0217] As described above, in the fourth modified example, the control apparatus 2 may determine whether or not the positional relationship between the build plate 113 and the blade 122 has been properly adjusted at the step S17. As a result, in a case where it is determined that the positional relationship between the build plate 113 and the blade 122 has not been properly adjusted at the step S17, the control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122 again. As a result, the build apparatus 1 does not start building the three-dimensional build object in a situation where the positional relationship between the build plate 113 and the blade 122 is not a proper positional relationship (for example, a positional relationship that satisfies at least one of the first and second adjustment conditions described above). Therefore, the build system SYS can build the three-dimensional build object more properly, compared to a case where the build apparatus 1 starts building the three-dimensional build object even in a case where the positional relationship between the build plate 113 and the blade 122 is not the proper positional relationship. For example, the build system SYS can build the three-dimensional build object with high accuracy.

[0218] (4-5) Fifth Modified Example In the above-described description, at the step S17 in FIG. 6, the control apparatus 2 adjusts the positional relationship between the build plate 113 and the blade 122 based on both of the plate measured result and the material layer measured result. In a fifth modified example, the control apparatus 2 may adjust the positional relationship between the build plate 113 and the blade 122 based on at least one of the plate measured result and the material layer measured result.

[0219] For example, the control apparatus 2 may adjust the position of the build plate 113 based on the plate measured result. As one example, the control apparatus 2 may calculate the attitude (namely, its position in the rotational direction) of the build plate 113 based on the plate measured result, and adjust the attitude of the build plate 113 based on the calculated result of the attitude of the build plate 113 so that the upper surface 1131 of the build plate 113 is parallel to a predetermined first reference plane. The horizontal plane (namely, the XY plane) is one example of the predetermined first reference plane.

[0220] For example, the control apparatus 2 may adjust the position of the blade 122 based on the material layer measured result. As one example, the control apparatus 2 may calculate the attitude (namely, the position in the rotational direction) of the material layer ML based on the material layer measured result, and adjust the attitude of the blade 122 based on the calculated result of the attitude of the material layer ML so that the lower surface 1221 of the blade 122, which is parallel to the upper surface MLs of the material layer ML, is parallel to a predetermined second reference plane. The horizontal plane (namely, the XY plane) is one example of the predetermined second reference plane.

[0221] The predetermined second reference plane that is used to adjust the position of the blade 122 may be the same as or may be different from the predetermined first reference plane that is used to adjust the position of the build plate 113. The second reference plane may be parallel to or may not be parallel to the first reference plane. In a case where the first reference plane is the same as or is parallel to the second reference plane, the upper surface 1131 of the build plate 113 is also parallel to the lower surface 1221 of the blade 122 even in the fifth modified example. In this case, the control apparatus 2 may be considered to adjusts the positional relationship between the build plate 113 and the blade 122 so as to satisfy the first adjustment condition “the upper surface 1131 of the build plate 113 is parallel to the upper surface MLs of the material layer ML formed on the build plate 113”even in the fifth modified example.

[0222] (4-6) Sixth Modified Example As described above, the control apparatus 2 may determine whether or not the material layer forming process for forming the material layer ML should be ended based on the measured result of the material layer ML by the measurement apparatus 14 in a period (a job period) during which the material layer ML is formed at the step S15 in FIG. 6. In a sixth modified example, the control apparatus 2 may perform a below-described operation in the period during which the material layer ML is formed at the step S15 in FIG. 6.

[0223] As a first example, the control apparatus 2 may use the measured result of the material layer ML by the measurement apparatus 14 for a purpose that is different from a purpose for determining whether or not the material layer should be ended. In this case, the measurement apparatus 14 may measure a first partial material layer PML formed to form the material layer ML and a second partial material layer PML formed subsequent to the first partial material layer PML to form the material layer ML. The first partial material layer PML may be a partial material layer PML that is formed first to form the material layer ML (a partial material layer PML for reference). The measurement apparatus 14 may measure at least one of the first and second partial material layers PML while the blade 122 moves between the end part AP and the end part BP to form the material layer ML. Then, the control apparatus 2 may compare the measured result of the first partial material layer PML and the measured result of the second partial material layer PML. Especially, the control apparatus 2 may compare the measured result of the first partial material layer PML and the measured result of the second partial material layer PML in the period (the job period) during which the material layer ML is formed at the step S15 in FIG. 6. As one example, the control apparatus 2 may determine, based on a compared result of the measured results of the first and second partial material layers PML, a positional alignment stability of the blade 122 in the period (the job period) during which the material layer ML is formed at the step S15 in FIG. 6. In other words, the control apparatus 2 may determine, based on a compared result of the measured results of the first and second partial material layers PML, whether or not the blade 122 accurately moves in the period (the job period) during which the material layer ML is formed at the step S15 in FIG. 6. As another example, the control apparatus 2 may determine (in other words, detect), based on a compared result of the measured results of the first and second partial material layers PML, whether or not the material layer forming process for forming the material layer ML at the step S15 in FIG. 6 includes a defect. Of course, the control apparatus 2 may calculate, based on a compared result of the measured results of the first and second partial material layers PML, the above-described measurement difference.

[0224] As a second example, in the above-described description, the control apparatus 2 may calculate (namely, acquire) the difference (the measurement difference) between the measured result of the material layer ML by the measurement apparatus 14 at the first time and the measured result of the material layer ML by the measurement apparatus 14 at the second time that is after the first time, and determine whether or not the material layer forming process should be ended by determining whether or not the calculated measurement difference is within the predetermined range. In the sixth modified example, the control apparatus 2 may determine whether or not the material layer forming process should be ended based on either one of the measured result of the material layer ML by the measurement apparatus 14 at the first time and the measured result of the material layer ML by the measurement apparatus 14 at the second time. For example, the control apparatus 2 may determine that the material layer forming process should be ended in a case where the measured result of the material layer ML by the measurement apparatus 14 at either one of the first and second times satisfies a predetermined end condition that should be satisfied for ending the material layer forming process.

[0225] As a third example, in the above-described description, the control apparatus 2 may determine that the material layer forming process should be ended by determining whether or not the measurement difference between the measured result of the material layer ML by the measurement apparatus 14 at the first time and the measured result of the material layer ML by the measurement apparatus 14 at the second time that is after the first time is within the predetermined range. In the sixth modified example, the control apparatus 2 may determine that the material layer forming process should be ended in a case where the number of times by which the blade 122 moves between the end part AP and the end part BP exceeds a predetermined upper threshold value. In other words, the control apparatus 2 may determine that the material layer forming process should be ended in a case where the number of the partial material layers PML that have been already formed to form the material layer ML exceeds the predetermined upper threshold value. In this case, the control apparatus 2 may notify an operator of the build apparatus 1 that an abnormality occurs in the build apparatus 1. This is because there is a possibility that abnormality occurs in the build apparatus 1 in a case where forming the material layer ML is not completed even when the number of times by which the blade 122 moves between the end part AP and the end part BP exceeds the predetermined upper threshold value. Incidentally, at least one of a shortage of the raw material RM stored in the material supply tank 111 and a misalignment of the blade 122 is one example of the abnormality occurring in the build apparatus 1.

[0226] (4-7) Seventh Modified Example In the above-described description, the build apparatus 1 supplies the raw material RM from the material supply tank 121 from below. However, the build apparatus 1 may supply the raw material RM from a hopper tank provided above the carrier 112 and / or the build plate 113. In other words, the material RM may be supplied from above the carrier 112 and / or the build plate 113.

[0227] With reference to FIG. 22, a seventh modified example in which the raw material RM is supplied from above the carrier 112 and / or the build plate 113 will be described. In the below-described description, in order to simplify the description, the same reference numerals are given to members that perform the same functions as in the above-described description, and the description thereof will be omitted.

[0228] In the seventh modified example illustrated in FIG. 22, the upper surface MLs of the material layer ML is scanned with a plurality of build lights BL1 and BL2 from a plurality of beam scanning apparatuses 13-1 and 13-2 to build the structural layer SL. The build apparatus 1 in the seventh modified example includes a layer forming apparatus 120 instead of the layer forming apparatus 12. The layer forming apparatus 120 includes a container 1201 that stores the raw material RM, a coater 1202 that moves on a lower surface 155 of the chamber 15 in the left-right direction (the Y direction) to form the material layer ML, and a powder dosing apparatus 1204 which is arranged below the container 1201 and which supplies a specifiable amount of the raw material RM from a supply port 1203 of the container 1201 to the coater 1201. Here, the coater 1202 may serve as a squeegee for forcing excess material RM into an overflow 41. Note that the excess raw material RM pushed into the overflow 41 falls into an overflow container 42.

[0229] The coater 1202 is moved in the left-right direction (the Y direction) by a non-illustrated driving system. The control apparatus 2 that controls the driving system controls the driving system to position the coater 1202 below the container 1201 and supplies a desired amount of raw material RM to the coater 1201 via the powder dosing apparatus 1204. The driving system is controlled so that the coater 1201 moves in the right direction (+Y direction) in the drawing to form the material layer ML. Then, the control apparatus 2 controls the driving system to position the coater 1201 below the powder dosing apparatus 1204, and reloads the coater 1201 with the raw material RM.

[0230] In the seventh modified example, since the amount of raw material RM supplied by the layer forming apparatus 120 can be changed, for example, when forming the first material layer ML on the build plate 113 by reciprocating the coater 1201 multiple times, it is also possible to shorten the time for forming the first material layer by increasing the amount of raw material RM supplied at the initial stage than the amount of raw material RM supplied at the final stage.

[0231] (4-8) Other Modified Example There is a possibility that at least one of the blade 122 of the layer forming apparatus 12 and the blade of the coater 1201 is damaged during the build operation period, or there is a possibility that at least one of the blade 122 of the layer forming apparatus 12 and the blade of the coater 1201 is suddenly displaced. In such cases, the upper surface MLs of the material layer ML may be measured by the measurement apparatus 14, and the position and / or the height of the build plate 113 may be adjusted based on the measured result. Thern, the layer forming apparatus 12 or 120 may be used to apply the material layer ML and continue the build operation.

[0232] In the above-described description, the build apparatus 1 melts the material layer ML by irradiating the material layer ML with the build light BL. However, the build apparatus 1 may melt the material layer ML by irradiating the material layer ML with any energy beam. At least one of a charged particle beam, an electromagnetic wave, and so on is one example of the arbitrary energy beam. At least one of an electron beam, an ion beam, and so on is one example of the charged particle beam.

[0233] (5) Supplementary Note Regarding the above described example embodiment, below described supplementary notes are further disclosed.Supplementary Note 1

[0234] A build system including: a build apparatus configured to build a three-dimensional build object by irradiating a material layer with an energy beam; and a control apparatus configured to control the build apparatus, wherein the build apparatus includes a layer forming apparatus configured to form a material layer, a measurement apparatus, and a moving apparatus configured to move at least one of at least a part of the layer forming apparatus and the build plate, and the control apparatus: acquires, from the measurement apparatus, a first measured result acquired by measuring the build plate and a second measured result acquired by measuring the material layer after the material layer is formed on the build plate; and makes at least one of the at least a part of the layer forming apparatus and the moving apparatus operate based on the first and second measured results.Supplementary Note 2

[0235] A build system including: a build apparatus configured to build a three-dimensional build object by irradiating a material layer with an energy beam; and a control apparatus configured to control the build apparatus, wherein the build apparatus includes a layer forming apparatus configured to form a material layer, a measurement apparatus, and a moving apparatus configured to move at least one of at least a part of the layer forming apparatus and the build plate, and the control apparatus: acquires, from the measurement apparatus, a first measured result acquired by measuring the build plate and a second measured result acquired by measuring the material layer after a measurement for acquiring the first measures result; and makes at least one of the at least a part of the layer forming apparatus and the moving apparatus operate based on the first and second measured results.Supplementary Note 3

[0236] A build method including: forming a material layer from a raw material; and building a three-dimensional build object by irradiating the material layer with an energy beam, wherein the build method comprises: forming a first material layer by supplying a raw material while moving a material supply member relative to a build plate; acquiring a first measured result of the first material layer by measuring the first material layer; acquiring a second measured result of a second material layer by measuring the second material layer formed on the first material layer; and acquiring a difference between the first measured result and the second measured result.Supplementary Note 4

[0237] A build system including: a build apparatus configured to build a three-dimensional build object by irradiating a material layer formed on a build plate with an energy beam; and a control apparatus configured to control the build apparatus, wherein the build apparatus includes a layer forming apparatus configured to form a material layer, a measurement apparatus, and a plate moving apparatus configured to move the build plate, and the control apparatus: controls the layer forming apparatus to form a first material layer by supplying a raw material while moving a material supply member of the layer forming apparatus relative to the build plate; controls the measurement apparatus to acquire a first measured result of the first material layer by measuring the first material layer; controls the measurement apparatus to acquire a second measured result of a second material layer by measuring the second material layer formed on the first material layer; and acquires a difference between the first measured result and the second measured result.Supplementary Note 5

[0238] A build system including: a build apparatus configured to build a three-dimensional build object by irradiating a material layer formed on a build plate with an energy beam; and a control apparatus configured to control the build apparatus, wherein the control apparatus: determines whether or not a surface of the build plate protrudes from a surface of a surrounding member that is disposed around the build plate in a direction intersecting the surface of the build plate based on a measured result that is acquired by a measurement apparatus measuring a state of the surface of the build plate before the material layer is formed on the build plate; and controls the build apparatus to start forming the material layer in a case where it is determined that the surface of the build plate does not protrude from the surface of the surrounding member.Supplementary Note 6

[0239] . The build system according to the Supplementary Note 5, wherein the control apparatus controls the build apparatus not to start forming the material layer in a case where it is determined that the surface of the build plate protrudes from the surface of the surrounding member.Supplementary Note 7

[0240] The build system according to the Supplementary Note 5 or 6, wherein the control apparatus: controls the build apparatus to adjust a position of the build plate until the surface of the build plate does not protrude from the surface of the surrounding member in a case where it is determined that the surface of the build plate protrudes from the surface of the surrounding member; and then, controls the build apparatus to start forming the material layer.

[0241] At least a part of the features of each embodiment and each modified example described above may be properly combined with at least another part of the features of each embodiment and each modified example described above. A part of the features of each embodiment and each modified example described above may not be used. Moreover, the disclosures of all publications and United States patents that are cited in each embodiment described above are incorporated in the disclosures of the present application by reference if it is legally permitted.

[0242] The present invention is allowed to be changed, if desired, without departing from the essence or spirit of the invention which can be read from the claims and the entire specification, and a build system and a build method, which involve such changes, are also intended to be within the technical scope of the present invention. Description of Reference Codes

[0243] SYS build system 1 build apparatus 11 stage apparatus 111 build tank 1111 side wall 1112 upper surface 112 carrier 113 build plate 1131 upper surface 114 carrier driving system 12 layer forming apparatus 121 material supply tank 122 blade 1221 lower surface 123 blade driving system 13 beam scanning apparatus 14 measurement apparatus 141 projection apparatus 142 capturing apparatus 2 control apparatus 21 arithmetic apparatus 22 storage apparatus 221 computer program ML material layer MLs upper surface PML partial material layer RM raw material SL structural layer BL build layer

Claims

1. A build system comprising: a build apparatus configured to build a three-dimensional build object by irradiating a material layer with an energy beam; and a control apparatus configured to control the build apparatus, wherein the build apparatus includes a layer forming apparatus configured to form a material layer, a measurement apparatus, and a moving apparatus configured to move at least one of at least a part of the layer forming apparatus and the build plate, and the control apparatus: acquires, from the measurement apparatus, a first measured result acquired by measuring the build plate before the material layer is formed on the build plate and a second measured result acquired by measuring the material layer after the material layer is formed on the build plate; and makes at least one of the at least a part of the layer forming apparatus and the moving apparatus operate based on the first and second measured results.

2. The build system according to claim 1, wherein the moving apparatus does not operate from a time at which the first measured result is acquired to a time at which the second measured result is acquired.

3. The build system according to claim 1 or 2, wherein the control apparatus acquires the second measured result from the measurement apparatus after acquiring the first measured result.

4. The build system according to any one of claims 1 to 3, wherein the control apparatus makes the layer forming apparatus in at least a part of a period from a time at which the first measured result is acquired to a time at which the second measured result is acquired.

5. The build system according to any one of claims 1 to 4, wherein the control apparatus makes at least one of the layer forming apparatus and the moving apparatus operate to change an attitude relationship between a surface of the material layer and a surface of the build plate based on the first and second measured results.

6. The build system according to claim 5, wherein the moving apparatus moves up and down the build plate.

7. The build system according to claim 6, wherein the control apparatus controls the moving apparatus to change the attitude relationship by changing an attitude of the build plate.

8. The build system according to claim 6 or 7, wherein the control apparatus controls the layer forming apparatus to change the attitude relationship by changing an attitude of at least a part of the layer forming apparatus that is allowed to contact with the material layer.

9. The build system according to any one of claims 5 to 8, wherein the control apparatus controls the measurement apparatus so that the measurement apparatus measures the build plate from which the material layer is removed after changing the attitude relationship.

10. The build system according to claim 9, wherein the control apparatus makes at least one of the layer forming apparatus and the moving apparatus operate to change the attitude relationship based on a third measured result acquired by measuring the build plate from which the material layer is removed.

11. The build system according to any one of claims 1 to 10, wherein the measurement apparatus measures at least a part of a surface of the build plate and a surface of the material layer.

12. The build system according to any one of claims 1 to 11, wherein the control apparatus makes at least one of the layer forming apparatus and the moving apparatus operate so that a surface of the build plate is parallel to a surface of the material layer formed on the build plate.

13. The build system according to any one of claims 1 to 12, wherein the control apparatus makes at least one of the layer forming apparatus and the moving apparatus operate so that a thickness of the material layer formed on the build plate is a desired thickness.

14. The build system according to any one of claims 1 to 13, wherein the control apparatus makes at least one of the layer forming apparatus and the moving apparatus operate based on the first and second measured results, and then controls the layer forming apparatus so that a contacting part of the layer forming apparatus, which contacts with the material layer, moves while contacting with the material layer.

15. The build system according to any one of claims 1 to 14, wherein the control apparatus: control the build apparatus to build a part of the three-dimensional build object by irradiating the material layer, which has been moved while the contacting part contacts with the material layer, with the energy beam; and controls at least one of the plate moving apparatus and the layer forming apparatus to form a material layer on the material layer on which the part of the three-dimensional build object has been formed.

16. The build system according to any one of claims 1 to 15, wherein the control apparatus controls the moving apparatus to adjust a position of the build plate before acquiring the first measured result.

17. The build system according to claim 16, wherein the position of the build plate includes at least one of a position of the build plate in a first direction that is along a surface of the build plate and a position of the build plate in a second direction that is a rotational direction around an axis intersecting with the first direction.

18. The build system according to claim 16 or 17, wherein the control apparatus controls the moving apparatus to adjust the position of the build plate so that the build plate is located in a measurement range of the measurement apparatus.

19. The build system according to claim 18, wherein the measurement apparatus includes: a projection apparatus configured to project a projection pattern across the build plate and a surrounding member that is disposed around the build plate; and a capturing apparatus configured to capture an image of the projection pattern to generate the image, the control apparatus controls the moving apparatus to adjust the position of the build plate based on a positional relationship between a first pattern part of the projection pattern that is projected on the build plate and a second pattern part of the projection pattern that is projected on the surrounding member in the image.

20. The build system according to any one of claims 1 to 19, wherein the measurement apparatus measures a position of the build plate, the control apparatus: calculates a position of a surrounding member that is disposed around the build plate based on a position measured result of the build plate; and controls the moving apparatus to adjust the position of the build plate based on the position measured result of the build plate and a calculated result of the position of the surrounding member.

21. The build system according to any one of claims 18 to 20, wherein the build plate is pre-heated after the adjustment of the position of the build plate is started.

22. The build system according to any one of claims 18 to 21, wherein the control apparatus adjusts the position of the build plate so that a distance between a surface of the build plate and a surface of a surrounding member, which is disposed around the build plate based, in a direction intersecting the surface of the object is equal to or shorter than a predetermined distance threshold value.

23. The build system according to any one of claims 18 to 22, wherein the control apparatus adjusts the position of the build plate so that an amount of a protrusion of the surface of the build plate from a surface of a surrounding member, which is disposed around the build plate, in a direction intersecting the surface of the build plate is equal to or shorter than a predetermined amount.

24. The build system according to any one of claims 1 to 23, wherein the first measured result is acquired after the build plate is pre-heated.

25. The build system according to any one of claims 1 to 24, wherein the measurement apparatus is configured to measure heights of a plurality of parts of a surface of the build plate, and is configured to measure heights of a plurality of parts of a surface of the material layer.

26. A build system comprising: a build apparatus configured to build a three-dimensional build object by irradiating a material layer with an energy beam; and a control apparatus configured to control the build apparatus, wherein the build apparatus includes a layer forming apparatus configured to form a material layer, a measurement apparatus, and a moving apparatus configured to move at least one of at least a part of the layer forming apparatus and the build plate, and the control apparatus: acquires, from the measurement apparatus, a material layer measured result acquired by the measurement apparatus measuring the material layer after the material layer is formed on the build plate; and makes at least one of the at least a part of the layer forming apparatus and the plate moving apparatus operate based on the material layer measured result.

27. The build system according to claim 26, wherein the control apparatus makes at least one of the layer forming apparatus and the moving apparatus operate to change an attitude relationship between a surface of the material layer and a surface of the build plate based on the material layer measured result.

28. The build system according to claim 26 or 27, wherein the control apparatus controls the moving apparatus to change an attitude of the build plate based on the material layer measured result.

29. The build system according to any one of claims 26 to 28, wherein the control apparatus changes an attitude of at least a part of the layer forming apparatus that is allowed to contact with the material layer based on the material layer measured result.

30. A build method which builds a three-dimensional build object by irradiating a material layer formed by a layer forming apparatus with an energy beam, the build method comprising: acquiring, from a measurement apparatus, a first measured result acquired by measuring a build plate before the material layer is formed on the build plate; acquiring, from the measurement apparatus, a second measured result acquired by measuring the material layer after the material layer is formed on the build plate; and manipulating at least one of at least a part of the layer forming apparatus and a moving apparatus based on the first and second measured results.

31. The build method according to claim 30, wherein the manipulating comprising controlling an actuator which operates at least one of the at least a part of the layer forming apparatus and the moving apparatus based on the first and second measured results.

32. A build method comprising: forming a material layer from a raw material; and building a three-dimensional build object by irradiating the material layer with an energy beam, wherein the build method comprises: forming a first material layer by supplying a raw material while moving a material supply member relative to a build plate; acquiring a first measured result of the first material layer by measuring the first material layer; forming a second material layer on the first material layer by supplying a raw material while moving the material supply member relative to the build plate after acquiring the first measured result; acquiring a second measured result of the second material layer by measuring the second material layer; and acquiring a difference between the first measured result and the second measured result.

33. The build method according to claim 32 further comprising determining whether or not a material layer forming process, which performs the forming the first material layer and the forming the second material layer a plurality of number of times, is ended based on the difference.

34. The build method according to claim 33 further comprising determining whether or not the difference is within a predetermined range.

35. The build method according to claim 34, wherein the material layer forming process is ended in a case where a determined result of the difference is within the predetermined range.

36. The build method according to claim 34 or 35, wherein the material layer forming process is continued in a case where a determined result of the difference is beyond the predetermined range.

37. The build method according to any one of claims 33 to 36 further comprising determining whether or not the material layer forming process based on a plurality of second measured results acquired at different timings, respectively.

38. The build method according to claim 37, wherein the material layer forming process is ended in a case where a difference between the plurality of second measured results is within a predetermined range.

39. The build method according to any one of claims 32 to 38, wherein each of first and second measured results includes information related to a three-dimensional shape of a surface of the material layer, the build method comprises: calculating a first plane fitting a three-dimensional shape of a surface of the first material layer based on the first measured result; and calculating a second plane fitting a three-dimensional shape a surface of the second material layer based on the second measured result, the difference includes a difference between the first plane and the second plane.

40. The build method according to any one of claims 32 to 39 further comprising comparing the first measured result and the second measured result in a job period during which a material layer forming process, which performs the forming the first material layer and the forming the second material layer a plurality of number of times, is performed.

41. The build method according to any one of claims 32 to 40 further comprising determining whether or not a material layer forming process, which performs the forming the first material layer and the forming the second material layer a plurality of number of times, is ended based on either one of the first measured result and the second measured result.

42. The build method according to any one of claims 32 to 41 further comprising determining that a material layer forming process, which performs the forming the first material layer and the forming the second material layer a plurality of number of times, is ended in a case where a number of times by which an operation for moving the material supply member relative to the build plate exceeds a predetermined upper threshold value.

43. A build system comprising: a build apparatus configured to build a three-dimensional build object by irradiating a material layer formed on a build plate with an energy beam; and a control apparatus configured to control the build apparatus, wherein the build apparatus includes a layer forming apparatus configured to form a material layer, a measurement apparatus, and a plate moving apparatus configured to move the build plate, and the control apparatus: controls the layer forming apparatus to form a first material layer by supplying a raw material while moving a material supply member of the layer forming apparatus relative to the build plate; controls the measurement apparatus to acquire a first measured result of the first material layer by measuring the first material layer; controls the layer forming apparatus to form a second material layer on the first material layer by supplying a raw material while moving the material supply member relative to the build plate after acquiring the first measured result; controls the measurement apparatus to acquire a second measured result of the second material layer by measuring the second material layer; and acquires a difference between the first measured result and the second measured result.

44. A build method of building the three-dimensional build object by using the build system according to any one of claims 1 to 29 and 43.

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