Three-dimensional object printing device

Abstract

The invention provides a three-dimensional object printing device which can suppress contact between a head and a workpiece while simplifying the structure of the device. The three-dimensional object printing apparatus includes: a moving mechanism having a carriage that moves along a first axis; a head that ejects a liquid toward the workpiece; a first lifting mechanism that is supported by the carriage and that lifts and lowers the head along a second axis that intersects the first axis; a first irradiation unit that is supported by the carriage and irradiates the workpiece with light that hardens the liquid ejected from the head; a first light shielding plate that is supported by the carriage, is disposed at a position between the head and the first irradiation unit in a direction along the first axis, and shields light from the first irradiation unit toward the head; and a first detection unit that detects contact with the workpiece on the basis of contact between the first light shielding plate and the workpiece.

Description

Technical Field

[0001] The present disclosure relates to a three-dimensional object printing apparatus. Background Art

[0002] There is known a three-dimensional object printing apparatus that performs printing on a workpiece having a three-dimensional surface by an inkjet method. For example, the apparatus described in Patent Document 1 includes an inkjet head, a unit that relatively moves an object and the inkjet head in the XY direction, a unit that measures the position of the inkjet head, a unit that measures the distance between the object and the inkjet head, and a mechanism that moves the inkjet head up and down based on the measurement result of the position and the measurement result of the distance.

[0003] In the apparatus described in Patent Document 1, when an error occurs in the measurement of the distance between the object and the inkjet head, or when the setting position of the object is shifted, there is a risk of collision between the inkjet head and the object during printing.

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2012-35552 Summary of the Invention

[0005] In order to solve the above problems, one aspect of the three-dimensional object printing apparatus of the present disclosure includes: a moving mechanism having a carriage that moves along a first axis; a head that ejects a liquid toward a workpiece; a first lifting mechanism that is supported by the carriage and moves the head up and down along a second axis intersecting the first axis; a first irradiation unit that is supported by the carriage and irradiates the workpiece with light that hardens the liquid ejected from the head; a first light shielding plate that is supported by the carriage and is disposed at a position between the head and the first irradiation unit in a direction along the first axis and shields light from the first irradiation unit toward the head; and a first detection unit that detects contact with the workpiece based on contact between the first light shielding plate and the workpiece. Brief Description of the Drawings

[0006] Figure 1 A perspective view showing an outline of the three-dimensional object printing apparatus according to the first embodiment.

[0007] Figure 2 A block diagram showing the electrical structure of the three-dimensional object printing apparatus according to the first embodiment.

[0008] Figure 3 A perspective view showing a structural example of a head unit.

[0009] Figure 4 A front view of the sensor unit according to the first embodiment.

[0010] Figure 5 A left side view of the sensor unit according to the first embodiment.

[0011] Figure 6 Right side view of the sensor unit of the first embodiment.

[0012] Figure 7 Cross-sectional view for explaining the mounting states of the detection unit and the light shielding plate of the first embodiment.

[0013] Figure 8 Schematic diagram for explaining the configurations of the sensor unit and the head unit.

[0014] Figure 9 Flowchart showing the operation of the three-dimensional object printing apparatus according to the first embodiment.

[0015] Figure 10 Diagram for explaining the start of the preparatory operation.

[0016] Figure 11 Diagram for explaining the execution of the preparatory operation.

[0017] Figure 12 Diagram for explaining the end of the preparatory operation.

[0018] Figure 13 Diagram for explaining the start of the printing operation.

[0019] Figure 14 Diagram for explaining the execution of the printing operation.

[0020] Figure 15 Diagram for explaining the end of the printing operation.

[0021] Figure 16 Diagram for explaining the start of the hardening operation.

[0022] Figure 17 Diagram for explaining the execution of the hardening operation.

[0023] Figure 18 Diagram for explaining the end of the hardening operation.

[0024] Figure 19 Flowchart showing the operation of the three-dimensional object printing apparatus according to the second embodiment.

[0025] Figure 20 Diagram for explaining the switching operation.

[0026] Figure 21 Flowchart showing the operation of the three-dimensional object printing apparatus according to the third embodiment.

[0027] Figure 22 The right side view of the sensor unit according to the fourth embodiment. Detailed implementation

[0028] Hereinafter, preferred embodiments of the present disclosure will be described with reference to the accompanying drawings. In the drawings, the dimensions and scales of each part are appropriately different from the actual situation, and there are also parts schematically shown for easy understanding. In addition, as long as there is no special limitation on the meaning of the present disclosure in the following description, the scope of the present disclosure is not limited to these embodiments.

[0029] In the following description, for ease of explanation, the X-axis, Y-axis, and Z-axis that intersect each other are appropriately used for description. The X-axis is an example of the "first axis", the Z-axis is an example of the "second axis", and the Y-axis is an example of the "third axis". In addition, in the following description, one direction along the X-axis is the X1 direction, and the direction opposite to the X1 direction is the X2 direction. Similarly, the directions opposite to each other along the Y-axis are the Y1 direction and the Y2 direction. In addition, the directions opposite to each other along the Z-axis are the Z1 direction and the Z2 direction.

[0030] Here, the X-axis, Y-axis, and Z-axis correspond to the coordinate axes of a general coordinate system set in the space where the moving mechanism 2 and the support mechanism 4 described later are provided. Typically, the Z-axis is an axis along the vertical direction, and the Z2 direction corresponds to the downward direction in the vertical direction. Hereinafter, for ease of explanation, a case where the operation of the moving mechanism 2 is controlled using the general coordinate system is exemplified.

[0031] In addition, the Z-axis may not be a vertical axis. In addition, although the X-axis, Y-axis, and Z-axis are typically orthogonal to each other, it is not limited thereto, and there are cases where they are not orthogonal. For example, the X-axis, Y-axis, and Z-axis only need to intersect each other at an angle within the range of 80° or more and 100° or less.

[0032] 1. First embodiment

[0033] 1-1. Outline of the printing device

[0034] Figure 1 It is a perspective view showing the outline of the three-dimensional object printing device 1 according to the first embodiment. The three-dimensional object printing device 1 is a device that performs printing on the surface of a three-dimensional workpiece W by an inkjet method. In addition, in Figure 1 , for ease of explanation, the base 10 and the housing 11 described later are briefly shown by a two-dot chain line.

[0035] The workpiece W has a surface WF including an area to be printed. In Figure 1In the illustrated example, the workpiece W is a substantially hemispherical body, and the surface WF is a substantially convex spherical surface. In addition, the size, shape, or setting attitude of the workpiece W is not limited to Figure 1 the illustrated example, but is arbitrary.

[0036] As Figure 1 shown, the three-dimensional object printing apparatus 1 includes a base 10, a housing 11, a moving mechanism 2, head units 3-1 to 3-6, sensor units 30-1 and 30-2, a support mechanism 4, and a maintenance mechanism 8. Hereinafter, based on Figure 1 this, each part of the three-dimensional object printing apparatus 1 will be briefly described in turn. In addition, hereinafter, the head units 3-1 to 3-6 may be referred to as the head unit 3. The sensor units 30-1 and 30-2 may be referred to as the sensor unit 30.

[0037] The base 10 is a pedestal having a surface 10a that supports the moving mechanism 2. The surface 10a is a surface facing the Z1 direction. Here, the moving mechanism 2 is directly or indirectly fixed to the base 10 by means of screw fixation or the like via other components.

[0038] In Figure 1 the illustrated example, the base 10 has a box shape, and the surface 10a is a surface facing the Z1 direction. An opening 10b is provided on the surface 10a. The opening 10b is used as a passage for allowing the support mechanism 4 to approach a position in the Z1 direction compared to the surface 10a from the inside of the base 10. In addition, a placement portion 10c is provided on the surface 10a. On the placement portion 10c, the workpiece W used in the subsequent printing or the like is placed so as to be accessible by the robotic arm 4W. In addition, the structure and configuration of the placement portion 10c are not limited to Figure 1 the illustrated example.

[0039] At a position in the Z1 direction with respect to the base 10, a housing 11 that surrounds the moving mechanism 2 and the like is disposed. The housing 11 is a box-shaped structure that forms a space for housing structures such as the moving mechanism 2 supported by the base 10 between the housing 11 and the surface 10a. The housing 11 has, for example, a plurality of columns and a plurality of beams made of metal or the like, and a plurality of plates such as a top plate and a wall plate made of a transparent material such as acrylic resin. In addition, the housing 11 has a visual confirmation portion 11a. The visual confirmation portion 11a is a window for allowing a user to visually confirm the workpiece W held by the robotic arm 4W in the direction along the Y axis. In addition, on the housing 11, a door (not shown) for supplying the workpiece W to the support mechanism 4 and taking out the workpiece W from the support mechanism 4 may be provided. This door may also serve as the visual confirmation portion 11a.

[0040] In addition, the structure of the base 10 is not limited to Figure 1The illustrated example is not limited to the shown structure but can be any structure. Additionally, the base 10 and the housing 11 can be set as needed or omitted. When the base 10 is omitted, each structural element of the three-dimensional object printing apparatus 1 is provided, for example, on the floor, wall, or ceiling of a building, etc.

[0041] The moving mechanism 2 is a mechanism that changes the relative positions of the head units 3-1 to 3-6 and the sensor units 30-1, 30-2 with respect to the workpiece W in the directions along the X-axis and the Y-axis. Thereby, the moving mechanism 2 moves the head 3a described later along each of the Z-axis and the X-axis intersecting the Z-axis.

[0042] The moving mechanism 2 includes an X moving mechanism 2X as an example of a "moving mechanism", Z moving mechanisms 2Z-1 to 2Z-6 as an example of a "first lifting mechanism", a Z moving mechanism 2Z-0 as an example of a "second lifting mechanism", and a Z moving mechanism 2Z-7. Therefore, the three-dimensional object printing apparatus 1 includes the X moving mechanism 2X and the Z moving mechanisms 2Z-0 to 2Z-7. Additionally, hereinafter, the respective Z moving mechanisms 2Z-0 to 2Z-7 may sometimes be referred to as the Z moving mechanism 2Z.

[0043] The X moving mechanism 2X is a linear motion mechanism that changes the relative positions of the head unit 3 and the sensor unit 30 with respect to the workpiece W along the X-axis orthogonal to the Z-axis. By using such an X moving mechanism 2X, the moving mechanism 2 moves the head 3a described later along the X-axis. In Figure 1 the illustrated example, the X moving mechanism 2X supports the head units 3-1 to 3-6 and the sensor units 30-1, 30-2 via the Z moving mechanisms 2Z-0 to 2Z-7, and simultaneously moves the Z moving mechanisms 2Z-0 to 2Z-7 along the X-axis. Thereby, the head units 3-1 to 3-6 and the sensor units 30-1, 30-2 move along the X-axis with respect to the workpiece W.

[0044] The X moving mechanism 2X has a pair of columns 2a, a beam 2b, a pair of rails 2c, and a movable body 2d as an example of a "carriage". These members are substantially rigid bodies and are made of, for example, metals such as iron, stainless steel, or aluminum alloy.

[0045] The pair of columns 2a are respectively members extending in the Z1 direction from the surface 10a of the base 10. In Figure 1 the illustrated example, the pair of columns 2a are arranged in the direction along the X-axis. A beam 2b is installed at the top ends of the pair of columns 2a. The beam 2b is a member supported by the pair of columns 2a. In Figure 1In the illustrated example, the beam 2b extends in the direction along the X-axis and is in the form of a plate with the direction along the Z-axis as the thickness direction. A pair of rails 2c are arranged on the surface of the beam 2b facing the Z1 direction. The pair of rails 2c are respectively linear rails that guide the movable body 2d to move relative to the pair of columns 2a and the beam 2b in the direction along the X-axis, and extend in the direction along the X-axis. The movable body 2d is mounted on the pair of rails 2c via a linear bearing (not shown). The movable body 2d is a component that moves relative to the pair of columns 2a and the beam 2b in the direction along the X-axis. Thus, the movable body 2d moves along the X-axis. In Figure 1 the illustrated example, the movable body 2d is in the form of a plate with the direction along the Z-axis as the thickness direction. Although not shown, the X moving mechanism 2X has an actuator and an encoder such as a linear encoder. The actuator has a motor such as a servo motor that generates a driving force for this movement, and the encoder detects the amount of movement of this movement. In addition, the structure of the X moving mechanism 2X is not limited to Figure 1 the illustrated example.

[0046] On the movable body 2d of the above X moving mechanism 2X, the Z moving mechanisms 2Z-0 to 2Z-7 are mounted via a support body 2e. Thus, accompanying the movement of the movable body 2d, the Z moving mechanisms 2Z-0 to 2Z-7 move in the direction along the X-axis. In Figure 1 the illustrated example, the Z moving mechanisms 2Z-0 to 2Z-7 are arranged in the X1 direction in this order.

[0047] In addition, the support body 2e can also be mounted on the movable body 2d via a manual or electric linear mechanism that moves the support body 2e relative to the movable body 2d in the direction along the Z-axis. In this case, the Z moving mechanisms 2Z-0 to 2Z-7 can be moved in the direction along the Z-axis together. In addition, the number of the Z moving mechanisms 2Z mounted on the X moving mechanism 2X is not limited to Figure 1 the illustrated example, and can also be less than 7 or more than 9.

[0048] The Z moving mechanisms 2Z-1 to 2Z-6 are respectively linear mechanisms that move the head unit 3 along the Z-axis relative to the workpiece W. Therefore, the Z moving mechanisms 2Z-1 to 2Z-6 are respectively supported by the movable body 2d and lift the head 3a described later along the Z-axis intersecting the X-axis.

[0049] The head units 3-1 to 3-6 respectively correspond one-to-one with the Z moving mechanisms 2Z-1 to 2Z-6. Moreover, the corresponding head units 3 are respectively installed on the Z moving mechanisms 2Z-1 to 2Z-6. Therefore, the Z moving mechanism 2Z-1 changes the relative position of the head unit 3-1 with respect to the workpiece W in the direction along the Z axis. Similarly, the Z moving mechanisms 2Z-2 to 2Z-6 respectively change the relative positions of the head units 3-2 to 3-6 with respect to the workpiece W in the direction along the Z axis. Thus, the Z moving mechanisms 2Z-1 to 2Z-6 change the relative positions of the head units 3-1 to 3-6 with respect to the workpiece W in an independent manner in the direction along the Z axis.

[0050] In contrast, the Z moving mechanisms 2Z-0 and 2Z-7 are linear motion mechanisms that move the sensor unit 30 along the Z axis with respect to the workpiece W, and operate independently of the aforementioned Z moving mechanisms 2Z-1 to 2Z-6. Therefore, the Z moving mechanism 2Z-0 is supported by the movable body 2d and raises and lowers a light shielding plate 37-1 described later along the Z axis. Similarly, the Z moving mechanism 2Z-7 is supported by the movable body 2d and raises and lowers a light shielding plate 37-2 described later along the Z axis.

[0051] The sensor unit 30-1 is installed on the Z moving mechanism 2Z-0, and the Z moving mechanism 2Z-0 moves the sensor unit 30-1 in the direction along the Z axis. The sensor unit 30-2 is installed on the Z moving mechanism 2Z-7, and the Z moving mechanism 2Z-7 moves the sensor unit 30-2 in the direction along the Z axis. Thus, the Z moving mechanisms 2Z-0 and 2Z-7 respectively change the relative positions of the sensor unit 30 with respect to the workpiece W in an independent manner from the respective head units 3-1 to 3-6 in the direction along the Z axis.

[0052] The above Z moving mechanisms 2Z-0 to 2Z-7 are constructed in the same manner as each other except that the objects to be moved are different as described above. Although not shown, the Z moving mechanisms 2Z-0 to 2Z-7 respectively have a rail, a movable body, an actuator, and an encoder. This rail is a linear rail fixed to the support body 2e and extending in the direction along the Z axis. This movable body is installed on this rail via a linear bearing and moves in the direction along the Z axis. This actuator has a motor such as a servo motor that generates a driving force for this movement. This encoder is a linear encoder or the like that detects the amount of movement of this movement. In addition, the structures of the Z moving mechanisms 2Z-0 to 2Z-7 may also be different from each other. However, from the aspect of cost reduction and the like, the Z moving mechanisms 2Z-0 to 2Z-7 are preferably of the same structure as each other. In addition, one of the Z moving mechanisms 2Z-0 and 2Z-7 may be provided as needed and may also be omitted.

[0053] In addition, on each of the Z moving mechanisms 2Z-0 to 2Z-7, the head unit 3 or the sensor unit 30 can also be installed via an adjustment mechanism for finely adjusting the attitude of the head unit 3 or the sensor unit 30. Furthermore, the number of Z moving mechanisms 2Z for installing the head unit 3 is not limited to Figure 1 the example shown, and can also be less than 5 or more than 7. Also, the number of Z moving mechanisms 2Z for installing the sensor unit 30 is not limited to Figure 1 the example shown, and can also be 1 or 3 or more. In addition, both the head unit 3 and the sensor unit 30 can be installed on the Z moving mechanism 2Z.

[0054] The head units 3-1 to 3-6 are each a component having a head 3a. Therefore, the three-dimensional object printing apparatus 1 includes the head 3a. The head 3a is an inkjet head of a piezoelectric driving method, a thermal method, or the like, and ejects ink, which is an example of a "liquid", in the Z2 direction, which is the direction along the Z axis, toward the workpiece W. In addition, the structural elements of the head unit 3, in addition to the head 3a, can include, for example, a heater and a temperature sensor, can also include a light source for hardening or curing the ink of the workpiece W, and can further include a pressure regulating valve for maintaining the pressure of the ink in the head 3a within a predetermined range.

[0055] The ink ejected by the head 3a is not particularly limited. In the present embodiment, a curable ink using a curable resin such as a thermosetting type, a photocurable type, a radiation curable type, and an electron beam curable type can be used. In addition, the ink is not limited to an ink containing a coloring material. For example, it can be an ink containing conductive particles such as metal particles for forming wirings or the like as a dispersion medium, can also be a transparent ink, and can also be a treatment liquid for surface treatment of the workpiece W. In addition, the types of ink used in the head units 3-1 to 3-6 can be the same as each other or different from each other.

[0056] The sensor unit 30 is a component having a detection unit 31, an irradiation unit 32, and a light shielding plate 37. Therefore, the three-dimensional object printing apparatus 1 includes the detection unit 31, the irradiation unit 32, and the light shielding plate 37. Here, the detection unit 31 included in the sensor unit 30-1, which is the detection unit 31-1 described later, is an example of the "first detection unit". The detection unit 31 included in the sensor unit 30-2, which is the detection unit 31-2 described later, is an example of the "second detection unit". The irradiation unit 32 included in the sensor unit 30-1, which is the irradiation unit 32-1 described later, is an example of the "first irradiation unit". The irradiation unit 32 included in the sensor unit 30-2, which is the irradiation unit 32-2 described later, is an example of the "second irradiation unit". The light shielding plate 37 included in the sensor unit 30-1, which is the light shielding plate 37-1 described later, is an example of the "first light shielding plate". The light shielding plate 37 included in the sensor unit 30-2, which is the light shielding plate 37-2 described later, is an example of the "second light shielding plate".

[0057] In Figure 1 In the example shown, the sensor unit 30 further includes a detection unit 33 in addition to the detection unit 31, the irradiation unit 32, and the light shielding plate 37, and is supported by the movable body 2d via the Z moving mechanism 2Z. The detection unit 31 is, for example, a contact-type sensor that detects contact with the workpiece W. As will be described in detail later, the detection unit 31 detects contact with the workpiece W based on the contact between the light shielding plate 37 and the workpiece W. The irradiation unit 32 irradiates the workpiece W with light that hardens the ink ejected from the head 3a. The irradiation unit 32 is composed of, for example, a light-emitting element such as an LED (Light Emitting Diode) that irradiates ultraviolet light. The light shielding plate 37 is disposed at a position between the head 3a and the irradiation unit 32-1 in the direction along the X axis, and shields the light LL from the irradiation unit 32-1 toward the head 3a. The detection unit 33 is an optical displacement sensor that detects the distance to the workpiece W. The detection unit 33 has a light source (not shown) that irradiates the workpiece W with laser light, and outputs a signal corresponding to the distance to the workpiece W in the direction along the Z axis based on the result of receiving the laser light reflected by the workpiece W. In addition, the detection unit 33 is provided as needed and may be omitted.

[0058] The support mechanism 4 is a mechanism that supports the workpiece W. In Figure 1 In the example shown, the support mechanism 4 includes a Y moving mechanism 4Y and a robotic arm 4W.

[0059] The Y moving mechanism 4Y is a linear motion mechanism that moves the robotic arm 4W along the Y axis. By this movement, the relative positions of the head units 3-1 to 3-6 and the sensor units 30-1 and 30-2 with respect to the workpiece W can be changed in the direction along the Y axis. In Figure 1In the illustrated example, the Y moving mechanism 4Y is disposed within the base 10.

[0060] The Y moving mechanism 4Y includes a support 4a, a pair of rails 4b, a movable body 4c, and a mounting table 4d. These components are substantially rigid bodies and are made of metals such as iron, stainless steel, or aluminum alloy, for example.

[0061] The support 4a is a base fixedly provided with respect to the base 10. Figure 1 In the illustrated example, the support 4a extends in the direction along the Y axis and is in the form of a plate with the direction along the Z axis as the thickness direction. A pair of rails 4b are disposed on the surface of the support 4a facing the Z1 direction. Additionally, the support 4a may be a part of the aforementioned base 10 or may be integrally formed with the base 10. Furthermore, the shape of the support 4a is not limited to Figure 1 the illustrated example, but can be any shape.

[0062] The pair of rails 4b are respectively linear rails that guide the movable body 4c to relatively move with respect to the support 4a in the direction along the Y axis and extend in the direction along the Y axis. The movable body 4c is mounted on the pair of rails 4b via a linear bearing (not shown). Additionally, the pair of rails 4b may also be integrally formed with the support 4a.

[0063] The movable body 4c is a component that relatively moves with respect to the support 4a in the direction along the Y axis. Figure 1 In the illustrated example, the movable body 4c is in the form of a plate with the direction along the Z axis as the thickness direction. Although not shown, the Y moving mechanism 4Y includes an actuator and an encoder such as a linear encoder. The actuator includes a motor such as a servo motor that generates a driving force for this movement, and the encoder detects the amount of movement of this movement. The mounting table 4d is mounted on the movable body 4c by means of screw fixation or the like.

[0064] The mounting table 4d is a component that supports the robotic arm 4W. Figure 1 In the illustrated example, the mounting table 4d is in the form of a plate. Additionally, an electric or manual adjustment mechanism for adjusting the position and attitude of the mounting table 4d with respect to the movable body 4c may be provided between the mounting table 4d and the movable body 4c. Furthermore, the mounting table 4d may also be integrally formed with the movable body 4c.

[0065] On the mounting table 4d of the above Y moving mechanism 4Y, the robotic arm 4W is mounted by means of screw fixation or the like. By the operation of the above Y moving mechanism 4Y, the workpiece W can be accurately moved along the Y axis without operating the robotic arm 4W.

[0066] The robotic arm 4W supports the workpiece W. The robotic arm 4W can change the position and posture of the workpiece W, and when performing the printing operation, it supports the workpiece W at a desired position and posture capable of receiving the ink ejected from the heads 3a of the head units 3-1 to 3-6. In Figure 1 In the illustrated example, the robotic arm 4W is a six-axis articulated robotic arm having an arm AR. Here, the base of the robotic arm 4W is fixed to the mounting table 4d. In addition, a hand mechanism that holds the workpiece W by electrostatic adsorption or the like or by gripping or the like is mounted at the tip of the arm AR of the robotic arm 4W as an end effector. Alternatively, the workpiece W may be fixed to the tip of the AR using a jig or the like.

[0067] The maintenance mechanism 8 is a mechanism for maintaining the head 3a of the head unit 3. In Figure 1 In the illustrated example, the maintenance mechanism 8 includes a cover mechanism 8F, a cover 8P, a cleaning device 8C, and a cleaning device moving mechanism 8M.

[0068] The cover mechanism 8F covers the unillustrated nozzle surface of the head 3a, thereby preventing drying, hardening, or curing of the ink near the nozzle of the nozzle surface, or preventing nozzle clogging by suction in the state of covering the nozzle surface.

[0069] The cover 8P can be moved in the direction along the Y axis by an unillustrated mechanism, and switches between a state of overlapping and a state of non-overlapping with the cover mechanism 8F when observed in the direction along the Z axis. Here, when the cover mechanism 8F is not in use, the cover 8P is in a state of overlapping with the cover mechanism 8F when observed in the direction along the Z axis, and functions as a cover for covering the cover mechanism 8F. The cover 8P in this state can also be used as an inspection table for supporting the medium for test printing. On the other hand, when the cover mechanism 8F is in use, the cover 8P is in a state of non-overlapping with the cover mechanism 8F when observed in the direction along the Z axis. In addition, although the cover 8P may be configured to be able to overlap with the cleaning device 8C when observed in the direction along the Z axis, when the cleaning device 8C is in use, it does not overlap with the cleaning device 8C when observed in the direction along the Z axis.

[0070] The cleaning device 8C is a mechanism for wiping the unillustrated nozzle surface of the head 3a, and is provided on the three-dimensional object printing device 1. In Figure 1 In the illustrated example, the cleaning device 8C is disposed at a position in the Y2 direction with respect to the cover mechanism 8F.

[0071] The cleaning device moving mechanism 8M moves the cleaning device 8C in the direction along the Y axis. Thus, the cleaning device moving mechanism 8M moves the cleaning device 8C along the Y axis relative to the head 3a. In Figure 1In the example shown, the cleaning device moving mechanism 8M moves the cover mechanism 8F in the direction along the Y-axis in addition to the cleaning device 8C. The cleaning device moving mechanism 8M has, for example, a support body fixed to the base 10, a pair of rails extending in the direction along the Y-axis, and a movable body that relatively moves along the Y-axis with respect to the support body along the pair of rails, similar to the Y moving mechanism 4Y. The cleaning device 8C and the cover mechanism 8F are fixed to the movable body by means such as screw fixation.

[0072] The cleaning device moving mechanism 8M can switch between multiple states, including a state where the cleaning of the head 3a achieved by the cleaning device 8C can be performed and a state where the capping of the head 3a can be performed by the cover mechanism 8F. In addition, when performing the cleaning of the head 3a achieved by the cleaning device 8C, the cleaning device moving mechanism 8M moves the cleaning device 8C in the direction along the Y-axis in a state where a wiping member (not shown) of the cleaning device 8C is in contact with the head 3a.

[0073] In addition, the structure of the maintenance mechanism 8 is not limited to Figure 1 the example shown. For example, the cover mechanism 8F and the cover 8P are provided as needed and can also be omitted. In addition, the maintenance mechanism 8 is provided as needed and can also be omitted.

[0074] 1-2. Electrical Structure of the Printing Device

[0075] Figure 2 It is a block diagram showing the electrical structure of the three-dimensional object printing device 1 according to the first embodiment. In Figure 2 , the electrical structure elements among the structure elements of the three-dimensional object printing device 1 are shown. As Figure 2 shown, in addition to having the structure elements shown above Figure 1 , the three-dimensional object printing device 1 further includes a control unit 50.

[0076] The control unit 50 controls the operations of the moving mechanism 2, the head units 3-1 to 3-6, the support mechanism 4, the sensor units 30-1, 30-2, and the maintenance mechanism 8. In the Figure 2 example shown, the control unit 50 includes a controller 5, a control module 6, and a computer 7. The control module 6 is an example of a "head control unit". Hereinafter, the controller 5, the control module 6, and the computer 7 will be described in sequence.

[0077] In addition, Figure 2Each of the electrical structural elements shown can be appropriately divided, or a part thereof can be included in other structural elements, or it can be integrally formed with other structural elements. For example, part or all of the functions of the controller 5 or the control module 6 can be implemented by the computer 7, or by other external devices such as a PC (Personal Computer) connected to the controller 5 via a network such as a LAN (Local Area Network) or the Internet.

[0078] The controller 5 has a function of controlling the driving of the moving mechanism 2 and the supporting mechanism 4, and a function of generating a signal D3 for synchronizing the ejection operation of the ink in the head unit 3 with the operation of the moving mechanism 2.

[0079] The controller 5 has a storage circuit 5a and a processing circuit 5b.

[0080] The storage circuit 5a stores various programs executed by the processing circuit 5b and various data processed by the processing circuit 5b. The storage circuit 5a includes, for example, a volatile memory such as a RAM (Random Access Memory), and one or both of non-volatile memories such as a ROM (Read Only Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), or a PROM (Programmable ROM). In addition, part or all of the storage circuit 5a may be included in the processing circuit 5b.

[0081] Path information Da and path information Db are stored in the storage circuit 5a.

[0082] The path information Da is information used for controlling the operation of the moving mechanism 2 and representing the position of the head 3a in the path to be moved by the head 3a as a target position. The path information Da is input from the computer 7 to the storage circuit 5a. The path information Db is information used for controlling the operation of the supporting mechanism 4 and representing the position and posture of the workpiece W in the path to be moved by the workpiece W as a target position and a target posture. The path information Db is generated by the computer 7 according to the user's settings. The path information Db is input from the computer 7 to the storage circuit 5a.

[0083] The processing circuit 5b controls the operations of the moving mechanism 2 and the supporting mechanism 4, and generates a signal D3. The processing circuit 5b includes, for example, one or more processors such as a CPU (Central Processing Unit). Additionally, the processing circuit 5b may be configured to include programmable logic devices such as an FPGA (Field-Programmable Gate Array) in addition to or instead of the CPU.

[0084] Specifically, the processing circuit 5b performs an operation to convert the path information Da into operation amounts such as the movement amount and movement speed of the moving mechanism 2. Then, based on the output signals Dx, Dz-0 to Dz-7 from the respective encoders of the moving mechanism 2, the processing circuit 5b outputs control signals Sx, Sz-0 to Sz-7 so that the actual operation amount of the moving mechanism 2 becomes the aforementioned operation result. The output signal Dx is a signal output from the encoder of the X moving mechanism 2X. The output signals Dz-0 to Dz-7 are signals output from the encoders of the Z moving mechanisms 2Z-0 to 2Z-7. The control signal Sx is a signal for controlling the drive of the actuator of the X moving mechanism 2X. The control signals Sz-0 to Sz-7 are signals for controlling the drive of the actuators of the Z moving mechanisms 2Z-0 to 2Z-7. Here, the control signals Sx, SZ-0 to Sz-7 can be corrected by the processing circuit 5b based on the output signal D1 from the detection unit 33 of the sensor unit 30 as needed.

[0085] In addition, the processing circuit 5b performs an operation, i.e., inverse kinematics calculation, to convert the path information Db into operation amounts such as the rotation angle and rotation speed of each joint of the robotic arm 4W. Then, based on the output Dw from the encoders provided at each joint of the robotic arm 4W, the processing circuit 5b outputs a control signal Sw so that the actual operation amounts such as the rotation angle and rotation speed of each joint become the aforementioned operation result. The control signal Sw is a signal for controlling the drive of the motors provided at each joint of the robotic arm 4W.

[0086] Moreover, the processing circuit 5b generates the signal D3 based on at least one of the output signals Dx, Dz-0 to Dz-7. For example, the processing circuit 5b may generate the signal D3 including a pulse at the timing when the output signal Dx becomes a predetermined value, or may output the output signal Dx as the signal D3 as it is.

[0087] The control module 6 is a circuit that controls the ink ejection operation in the head unit 3 based on the signal D3 output from the controller 5 and the print data from the computer 7. The control module 6 includes a timing signal generation circuit 6a, a power supply circuit 6b, a control circuit 6c, and a drive signal generation circuit 6d.

[0088] The timing signal generation circuit 6a generates a timing signal PTS based on the signal D3. The timing signal generation circuit 6a is constituted by, for example, a timer that starts generating the timing signal PTS triggered by the detection of the signal D3, or, in the case where the signal D3 is the output signal Dx, a circuit that generates a signal including a pulse having a timing synchronized with the pulse of the output signal Dx as the timing signal PTS.

[0089] The power supply circuit 6b receives power supply from a commercial power supply (not shown) and generates various predetermined potentials. For example, the power supply circuit 6b generates a power supply potential VHV and a bias potential VBS. The bias potential VBS is supplied to the head unit 3. In addition, the power supply potential VHV is supplied to the drive signal generation circuit 6d.

[0090] The control circuit 6c generates control signals SI-1 to SI-6, a waveform designation signal dCom, a latch signal LAT, a clock signal CLK, and a switching signal CNG based on the timing signal PTS. These signals are synchronized with the timing signal PTS. The waveform designation signal dCom among these signals is input to the drive signal generation circuit 6d, and the other signals are input to the switching circuit 3e of the head unit 3. The control signals SI-1 to SI-6 respectively correspond one-to-one to the head units 3-1 to 3-6. In addition, hereinafter, each of the control signals SI-1 to SI-6 may sometimes be referred to as the control signal SI.

[0091] The control signal SI is a digital signal for designating the operating state of the drive element included in the head 3a of the head unit 3. Specifically, the control signal SI is a signal for designating whether to supply a drive signal Com (described later) to the drive element based on print data. By this designation, for example, it is designated whether to eject ink from the nozzle corresponding to the drive element, or the amount of ink ejected from the nozzle is designated. The waveform designation signal dCom is a digital signal for prescribing the waveform of the drive signal Com. The latch signal LAT and the switching signal CNG are signals for prescribing the ejection timing of ink ejected from the nozzle by prescribing the drive timing of the drive element in combination with the control signal SI. The clock signal CLK is a clock signal serving as a reference synchronized with the timing signal PTS.

[0092] The above control circuit 6c includes, for example, one or more processors such as a CPU. In addition, the control circuit 6c may be configured to include a programmable logic device such as an FPGA in addition to or instead of the CPU.

[0093] The drive signal generation circuit 6d is a circuit that generates a drive signal Com for driving each drive element included in the head 3a of the head unit 3. Specifically, the drive signal generation circuit 6d includes, for example, a DA conversion circuit and an amplification circuit. In the drive signal generation circuit 6d, the waveform specification signal dCom from the control circuit 6c is converted from a digital signal to an analog signal by the DA conversion circuit, and the amplification circuit amplifies this analog signal using the power supply potential VHV from the power supply circuit 6b, thereby generating the drive signal Com. Here, the signal of the waveform actually supplied to the drive element among the waveforms included in the drive signal Com is the drive pulse PD. The drive pulse PD is supplied from the drive signal generation circuit 6d to the drive element via the switch circuit 3e of the head unit 3.

[0094] Here, the switch circuit 3e is a circuit including a switching element that switches whether to supply at least a part of the waveforms included in the drive signal Com as the drive pulse PD based on the control signal SI.

[0095] The computer 7 is, for example, a desktop computer installed with a program. The computer 7 has functions of generating path information Da, Db, supplying information such as the path information Da, Db to the controller 5, and supplying information such as print data to the control module 6. In addition to these functions, the computer 7 of the present embodiment also has a function of controlling the operations of the moving mechanism 2 and the like based on the detection results of the detection units 31, 33 of the sensor unit 30 to prevent the workpiece W from colliding with the head 3a, a function of controlling the drive of the irradiation unit 32 of the sensor unit 30, and a function of controlling the operations of the maintenance mechanism 8.

[0096] The computer 7 has a storage circuit 7a and a processing circuit 7b. The storage circuit 7a stores various programs executed by the processing circuit 7b and various data such as the path information Da processed by the processing circuit 7b. The storage circuit 7a includes, for example, one or both of semiconductor memories such as volatile memories like RAM, ROM, EEPROM, or PROM. In addition, part or all of the storage circuit 7a may be included in the processing circuit 7b.

[0097] The processing circuit 7b realizes various functions by reading and executing programs from the storage circuit 7a. The processing circuit 7b includes, for example, one or more processors such as a CPU. In addition, the processing circuit 7b may be configured to include programmable logic devices such as FPGA in addition to or instead of the CPU.

[0098] 1-3. Head Unit

[0099] Figure 3 is a perspective view showing a structural example of the head unit 3. AsFigure 3 As shown, the head unit 3 has, in addition to the head 3a, a support 3g, a cover 3h, and a protection member 3f. Among the elements constituting the head unit 3, the elements other than the support 3g are directly or indirectly supported by the support 3g. In addition, the structural elements of the head unit 3 are not limited to Figure 3 the example shown. For example, it may include a heater and a temperature sensor, etc., may also include a light source for hardening or curing the ink of the workpiece W, and may further include a pressure regulating valve for maintaining the pressure of the ink in the head 3a within a predetermined range by negative pressure.

[0100] The support 3g is supported by being mounted on the Z moving mechanism 2Z by means of screw fixation or the like. Therefore, the head 3a etc. are supported on the Z moving mechanism 2Z together through the support 3g.

[0101] The support 3g is a substantial rigid body and is made of, for example, a metal material or the like. In addition, although in Figure 3 the support 3g is in a plate shape, the shape of the support 3g is not particularly limited and is an arbitrary shape. In addition, the support 3g may also be composed of a plurality of components.

[0102] At the position in the X1 direction with respect to the aforementioned support 3g, the head 3a and the cover 3h are arranged. These members are fixed to the support 3g by means of screw fixation or the like.

[0103] The head 3a has a nozzle surface FN that extends along the Y axis and is in a long and narrow shape, and a plurality of nozzles N that open on the nozzle surface FN. In Figure 3 the example shown, the nozzle surface FN is the surface of the head 3a facing the Z2 direction, and the plurality of nozzles N are divided into a nozzle row NLa and a nozzle row NLb that are arranged at intervals in the direction along the X axis. The nozzle row NLa and the nozzle row NLb are respectively a set of a plurality of nozzles N that are arranged in a straight line in the nozzle row direction DN that is the direction along the Y axis. Here, the elements associated with the respective nozzles N of the nozzle row NLa and the elements associated with the respective nozzles N of the nozzle row NLb in the head 3a are structures that are substantially symmetric with each other in the direction along the X axis. Hereinafter, the set of the nozzle row NLa and the nozzle row NLb may sometimes be referred to as the nozzle row NL.

[0104] Although not shown, the head 3a has a piezoelectric element as a driving element for each nozzle N and a chamber for storing ink. Here, the piezoelectric element causes the ink to be ejected from the nozzle corresponding to the chamber by changing the pressure in the chamber corresponding to the piezoelectric element. Such a head 3a is obtained, for example, by bonding together a plurality of substrates such as a silicon substrate appropriately processed by etching or the like using an adhesive or the like. In addition, as a driving element for ejecting the ink from the nozzle, a heater for heating the ink in the chamber may be used instead of the piezoelectric element.

[0105] Here, the head 3a has a nozzle plate that constitutes at least a part of the nozzle surface FN. The nozzle plate is a plate-like member provided with the aforementioned plurality of nozzles N and is made of a material such as silicon (Si) or metal. At least a part of the nozzle surface FN is constituted by a plate surface that constitutes a part of the outer surface of the head 3a among a pair of plate surfaces of the nozzle plate, that is, the surface of the nozzle plate facing the Z2 direction. In addition, the head 3a sometimes has a fixing plate or a head cover that constitutes at least a part of the nozzle surface FN. In this case, the fixing plate or the head cover is a member provided for the purpose of fixing or protecting the nozzle plate and is configured to cover the outer periphery of the nozzle plate when viewed in the Z1 direction and is made of a material such as metal. Thus, sometimes the nozzle surface FN is constituted by the surface facing the Z2 direction of the outer surface of the fixing plate or the head cover in addition to the nozzle plate. In addition, the nozzle surface FN constitutes at least a part of the ejection surface FT. The ejection surface FT is the end surface of the head unit 3 in the Z2 direction. The length Wn in the Y-axis direction of the ejection surface FT is the width of the head 3a.

[0106] An ink tank (not shown) is connected to the above-described head 3a via a supply pipe 3i1 and a discharge pipe 3i2. The supply pipe 3i1 is a pipe body for supplying ink to the head 3a. The discharge pipe 3i2 is a pipe body for recovering the ink discharged from the head 3a.

[0107] The cover 3h is a box-shaped member that covers the periphery of the flow path structure 3b.

[0108] In addition, a protection member 3f is provided at a position in the Z2 direction with respect to the aforementioned support 3g. The protection member 3f is a member for protecting the head 3a from collision with the workpiece W or the like and is made of a metal material such as stainless steel, titanium, and magnesium alloy. An opening 3f1 for exposing the nozzle surface FN of the head 3a is provided in the protection member 3f.

[0109] The surface FC facing the Z2 direction of the above-described protection member 3f and the nozzle surface FN of the above-described head 3a constitute the ejection surface FT. Therefore, the ejection surface FT includes the surface FC and the nozzle surface FN and constitutes the top surface of the head unit 3 facing the Z2 direction.

[0110] In addition, the protection member 3f is provided as needed and may also be omitted. Furthermore, although in the present embodiment, the number of nozzle surfaces FN or nozzle plates included in the ejection surface FT is one, it is not limited thereto, and the number of nozzle surfaces FN or nozzle plates included in the ejection surface FT may also be plural.

[0111] 1-4. Sensor unit

[0112] Figure 4 is a front view of the sensor unit 30 of the first embodiment. In Figure 4 is shown the sensor unit 30-2 observed in the Y1 direction. Figure 5 is a left side view of the sensor unit 30 of the first embodiment. In Figure 5 is shown the sensor unit 30-2 observed in the X1 direction. Figure 6 is a right side view of the sensor unit 30 of the first embodiment. Figure 6 is shown the sensor unit 30-2 observed in the X2 direction. In addition, the sensor unit 30-1 is configured in the same manner as the sensor unit 30-2 except that it is symmetric in the direction along the X axis.

[0113] As Figures 4 to 6 shown, the sensor unit 30 has, in addition to the detection units 31, 33, the irradiation unit 32, and the light shielding plate 37, a support 34, a mounting member 35, and a buffer 36. Among the elements constituting the sensor unit 30, the elements other than the support 34 are directly or indirectly supported by the support 34. Furthermore, the structural elements of the sensor unit 30 are not limited to Figures 4 to 6 the example shown.

[0114] The support 34 is supported by being mounted on the Z moving mechanism 2Z-0 or the Z moving mechanism 2Z-7 by means of screw fixation or the like. Therefore, each part of the sensor unit 30 is supported together on the Z moving mechanism 2Z.

[0115] The support 34 is a substantial rigid body and is made of, for example, a metallic material or the like. In addition, the shape of the support 34 is not limited to Figures 4 to 6 the example shown, but may be any shape. Furthermore, the support 34 may be composed of a plurality of components.

[0116] The irradiation unit 32, the detection unit 33, and the mounting member 35 are respectively fixed to the support 34 by means of screw fixation or the like.

[0117] The irradiation unit 32 has an irradiation surface FL that irradiates light for hardening the ink ejected from the head 3a. In the direction along the Y-axis, the length Wu of the irradiation surface FL of the irradiation unit 32 from one end to the other end is preferably equal to or greater than the length Wn of the head 3a from one end to the other end. When performing printing on the three-dimensional printing surface of the workpiece W, depending on the shape of the printing surface, the ink splashed on the printing surface may sometimes be prone to deviation or spreading. Therefore, by setting the width, i.e., the length Wu, of the irradiation surface FL to be equal to or greater than the width, i.e., the length Wn, of the head 3a, the ink splashed on the printing surface can be hardened quickly. As a result, the deviation or spreading of the ink splashed on the printing surface can be suppressed.

[0118] The detection unit 33 has a light source (not shown) that irradiates laser light in the Z2 direction. The detection unit 33 outputs a signal corresponding to the distance from the workpiece W in the direction along the Z-axis based on the result of receiving the laser light reflected by the workpiece W.

[0119] The mounting member 35 is a member for mounting the detection unit 31, the buffer 36, and the light shield 37 on the support 34. The mounting member 35 is a substantially rigid body and is made of, for example, a metal material.

[0120] The mounting member 35 is fixed to the support 34 by means of screw fixation or the like. As Figure 5 shown, a plurality of long holes 35a extending in the direction along the Z-axis are provided in the mounting member 35. The mounting member 35 uses these plurality of long holes 35a and is mounted on the support 34 by means of screw fixation or the like. Therefore, the mounting position of the mounting member 35 relative to the support 34 in the direction along the Z-axis can be adjusted. In addition, the shape of the mounting member 35 is not limited to the Figures 4 to 6 example shown, but can be any shape. In addition, the mounting member 35 may be composed of a plurality of components. Moreover, the mounting member 35 is provided as needed and can also be omitted. In this case, for example, the detection unit 31, the buffer 36, and the light shield 37 are directly mounted on the support 34 or via other components.

[0121] On the mounting member 35, the detection unit 31 and the light shield 37 are mounted via the buffer 36. Here, in the direction along the X-axis, the detection unit 31 and the light shield 37 are respectively arranged at positions opposite to the detection unit 33 with respect to the irradiation unit 32.

[0122] The detection unit 31 is a contact-type sensor having a needle-like body 31a and a sensor 31b. The needle-like body 31a is a wire material having a tip E1 that contacts the light shielding plate 37, and extends from the sensor 31b toward the light shielding plate 37. The sensor 31b is a tactile switch that detects the displacement of the tip E1, and is fixed to a component 36a (described later) of the buffer body 36 by screw fixation or the like. In the detection unit 31 having such a needle-like body 31a and a sensor 31b, the contact with the workpiece W can be detected by the detection unit 31-1 under the condition that problems such as the hardening of the ink of the head 3a due to light do not occur.

[0123] The light shielding plate 37 is a plate-like component having the direction along the X axis as the thickness direction, and is made of, for example, metal or resin. From the aspect of preventing unintended light reflection, the surface of the light shielding plate 37 is preferably black or dark-colored by painting or surface treatment. For example, it is preferable that the surface of the light shielding plate 37 made of aluminum or aluminum alloy is subjected to anodic oxidation treatment to become black. The end portion of the light shielding plate 37 in the Z1 direction is a fixed end fixed to a component 26 (described later) of the buffer body 36. On the other hand, the end portion of the light shielding plate 37 in the Z2 direction, that is, the lower end E2, is a free end.

[0124] The top E1 of the needle-like body 32a of the detection unit 31 contacts one surface of the light shielding plate 37 near the lower end E2. In the illustrated example, on this one surface of the light shielding plate 37, a groove 37a extending in the direction along the Z axis is provided, and the tip E1 of the needle-like body 32a is arranged in the groove 37a in a state capable of moving along the groove 37a.

[0125] The width of the light shielding plate 37 is preferably equal to or greater than the width of the head 3a. That is, in the direction along the Y axis, the length Ws of the light shielding plate 37 from one end to the other end is preferably equal to or greater than the length Wn of the head 3a from one end to the other end. Thus, by setting the width, that is, the length Ws of the light shielding plate 37 to be equal to or greater than the width, that is, the length Wn of the head 3a, the light from the irradiation unit 32 to the head 3a can be appropriately shielded by the light shielding plate 37.

[0126] The buffer body 36 is a structure for absorbing the impact applied to the light shielding plate 37. The buffer body 36 has a component 36a, a component 36b, an elastic component 36c, and a plurality of leaf springs 36d.

[0127] The component 36a is a structure that is fixed to the mounting component 35 by means of screw fixation or the like and supports the component 36b via the elastic component 36c. On the component 36a, a sensor 31b of the detection unit 31 is fixed via a fixing member (not shown). The component 36b is a structure that supports the light shielding plate 37. The elastic component 36c is a plate-shaped component made of an elastic material such as rubber. Each of the plurality of leaf springs 36d is a metal plate capable of elastic deformation, and an elastic force acts between the component 36a and the component 36b to maintain the state of the elastic component 36c in a reference state. As Figure 5 shown, the end portions of each leaf spring 36d in the Z1 direction are fixed to the component 36a by means of screw fixation or the like. Further, at the end portions of each leaf spring 36d in the Z2 direction, long holes 36d1 extending in the direction along the Z axis are provided. Each leaf spring 36d is mounted on the component 36b using the long holes 36d1 and by means of screw fixation or the like to allow deformation in the thickness direction.

[0128] Figure 7 FIG. is a cross-sectional view for explaining the mounting states of the detection unit 31 and the light shielding plate 37 of the first embodiment. As Figure 7 shown, the component 36a has components 36a1 and 36a2. The components 36a1 and 36a2 are fixed to each other by means of screw fixation or the like. Here, the end portion of the elastic component 36c in the Z1 direction is clamped between the component 36a1 and the component 36a2. Thus, the end portion of the elastic component 36c in the Z1 direction is fixed to the component 36a.

[0129] The component 36b has components 36b1, 36b2, and 36b3. The components 36b2 and 36b3 are respectively fixed to the component 36b1 by means of screw fixation or the like. Here, the end portion of the elastic component 36c in the Z2 direction is clamped between the component 36b1 and the component 36b2. Thus, the end portion of the elastic component 36c in the Z2 direction is fixed to the component 36b. Further, the end portion of the light shielding plate 37 in the Z1 direction is clamped between the component 36b1 and the component 36b3. Thus, the end portion of the light shielding plate 37 in the Z1 direction is fixed to the component 36b.

[0130] In this way, the light shielding plate 37 is fixed to the Z moving mechanism 2Z-0 or the Z moving mechanism 2Z-7 via the elastic elastic component 36c. The lower end E2 of the light shielding plate 37 in the vertical direction is a free end. Thus, when the light shielding plate 37-1 contacts the workpiece W, the light shielding plate 37-1 can rotate about the fixed end. Therefore, damage to the workpiece W caused by contact with the light shielding plate 37-1 can be suppressed.

[0131] The detection unit 31 is configured to use the sensor 31b to detect the tip E1 from Figure 7It is detected whether the displacement from the natural state indicated by the double-dashed line in [the figure] is equal to or greater than a predetermined distance. The needle 31a contacts the light-shielding plate 37 in a state where the initial displacement is made at the tip E1 in such a manner as to reduce the predetermined distance. That is, an external force is applied to the needle 31a in advance to reduce the play in the detection performed by the sensor 31b. Thereby, it is possible to quickly detect by the detection unit 31 that the light-shielding plate 37 has come into contact with the workpiece W. Therefore, even if the length La between the head 3a and the light-shielding plate 37 is shortened, it is possible to appropriately suppress the collision between the workpiece W and the head 3a. In addition, this play is about 5 mm as the difference at the tip E1, and it is preferably reduced to about 3 mm.

[0132] In addition, the buffer 36 is not limited to Figure 7 the example shown. For example, the component 36a and the component 36b may also be connected via a movable structure such as a hinge. In addition, the shape of the elastic member 36c is not limited to the example shown in the figure, but may be any shape. However, if the elastic member 36c is sheet rubber, there is an advantage that it is easy to miniaturize the buffer 36. In addition, the buffer 36 is provided as needed and may be omitted.

[0133] Figure 8 It is a schematic diagram for explaining the configuration of the sensor units 30-1, 30-2 and the head units 3-1 to 3-6. As Figure 8 shown, the sensor unit 30-1 is arranged at a position in the X2 direction with respect to the plurality of heads 3a, while the sensor unit 30-2 is arranged at a position in the X1 direction with respect to the plurality of heads 3a. However, the sensor unit 30-1 and the sensor unit 30-2 are configured symmetrically in the direction along the X axis.

[0134] Specifically, the sensor unit 30-1 includes a detection unit 31-1, an irradiation unit 32-1, and a light-shielding plate 37-1. The detection unit 31-1 is the detection unit 31 included in the sensor unit 30-1. The irradiation unit 32-1 is the irradiation unit 32 included in the sensor unit 30-1. The light-shielding plate 37-1 is the light-shielding plate 37 included in the sensor unit 30-1. In the sensor unit 30-1, the irradiation unit 32-1, the light-shielding plate 37-1, and the detection unit 31-1 are arranged in this order toward the X1 direction.

[0135] In the direction along the X axis, the length La between the head 3a and the light-shielding plate 37-1 is equal to or greater than the length Lc between the irradiation unit 32-1 and the light-shielding plate 37-1. Thereby, compared with the case where the length La between the head 3a and the light-shielding plate 37-1 is shorter than the length Lc between the irradiation unit 32-1 and the light-shielding plate 37-1, it is possible to improve the light-shielding effect required for the light-shielding plate 37-1.

[0136] In the direction along the X-axis, the length La between the head 3a and the light shield 37-1 is longer than the moving distance required from the detection of the contact between the workpiece W and the light shield 37-1 based on the detection result of the detection unit 31-1 until the movable body 2d stops. Thus, the contact between the head 3a and the workpiece W can be more reliably suppressed. For example, when the scanning speed of the head 3a is 300 mm / s, the moving distance required from the detection of the contact between the workpiece W and the light shield 37-1 until the movable body 2d stops is a dozen millimeters.

[0137] On the other hand, the sensor unit 30-2 includes a detection unit 31-2, an irradiation unit 32-2, and a light shield 37-2. The detection unit 31-2 is the detection unit 31 included in the sensor unit 30-2. The irradiation unit 32-2 is the irradiation unit 32 included in the sensor unit 30-2. The light shield 37-2 is the light shield 37 included in the sensor unit 30-2. In the sensor unit 30-2, the irradiation unit 32-2, the light shield 37-2, and the detection unit 31-2 are arranged in order in the X2 direction.

[0138] In this way, the detection unit 31-2 is arranged in a position opposite to the position where the light shield 37-1 is arranged with respect to the head 3a in the direction along the X-axis. That is, the detection units 31-1 and 31-2 are arranged so as to sandwich the head 3a in the direction along the X-axis. Thus, when printing the workpiece W by the reciprocating scan of the head 3a, since the detection units 31-1 and 31-2 are arranged in front of and behind the head 3a in the moving direction of the head 3a, the contact between the head 3a and the workpiece W can be suppressed.

[0139] The irradiation unit 32-2 is arranged in a position opposite to the position where the light shield 37-1 is arranged with respect to the head 3a in the direction along the X-axis. In addition, the light shield 37-2 is arranged at a position between the head 3a and the irradiation unit 32-2 in the direction along the X-axis. By such an arrangement of the irradiation unit 32-2 and the light shield 37-2, necessary light shielding for the head 3a can be achieved in the same way as the irradiation unit 32-1 and the light shield 37-1, and when printing the workpiece W by the reciprocating scan of the head 3a, the ink on the workpiece W can be hardened in the forward path and the return path respectively, thereby improving the productivity. In addition, by using the light shield 37-2 for the detection unit 31-2, the device structure can be simplified compared with the method of using another component to improve the detection accuracy of the detection unit 31-2.

[0140] 1-5. Control Method

[0141] Figure 9The flowchart shows the operation of the three-dimensional object printing apparatus 1 according to the first embodiment. In the three-dimensional object printing apparatus 1, first, in step S1, it is determined whether there is a printing instruction. This determination is made in the computer 7, for example, based on an operation performed by the user on the three-dimensional object printing apparatus 1. Step S1 is repeatedly executed until it is determined that there is a printing instruction (step S1: No).

[0142] When it is determined that there is a printing instruction (step S1: Yes), in step S2, a preparatory operation is executed. In the preparatory operation, ink is not ejected from the head 3a, and the shutter 37 is moved along the path shown by the path information Da to check the path shown by the path information Da.

[0143] In addition, the positioning of the workpiece W is completed before the preparatory operation is executed. For example, when it is determined that there is a printing instruction (step S1: Yes), the workpiece W can be moved by the support mechanism 4 to a position where the surface WF of the workpiece W can face the head 3a in the direction along the Z axis, or the workpiece W can be moved by the support mechanism 4 before the printing instruction is given.

[0144] After step S2, in step S3, a printing operation is executed. In the printing operation, while moving the head 3a along the path shown by the path information Da, ink is ejected from the head 3a.

[0145] After step S3, in step S4, a hardening operation is executed. In the hardening operation, while moving the irradiation unit 32 along the path shown by the path information Da, the ink on the workpiece W is hardened by the light from the irradiation unit 32.

[0146] After step S4, in step S5, it is determined whether there is an end instruction. This determination is made in the computer 7, for example, based on an operation performed by the user on the three-dimensional object printing apparatus 1.

[0147] When it is determined that there is no end instruction (step S5: No), step S1 is executed. On the other hand, when it is determined that there is an end instruction (step S5: Yes), the process ends.

[0148] Figure 10 The figure is for explaining the start of the preparatory operation. Figure 11 The figure is for explaining the execution of the preparatory operation. Figure 12 The figure is for explaining the end of the preparatory operation. In Figures 10 to 12 it illustrates a manner in which the movable body 2d of the X moving mechanism 2X is moved in the X1 direction in the preparatory operation of step S2.

[0149] As Figure 10As shown, at the start of the preparatory operation, in a region deviated from the region on the workpiece W, the Z moving mechanisms 2Z-1 to 2Z-6 raise the head 3a by a predetermined amount and raise it to a position where contact with the workpiece W is easily prevented, and the Z moving mechanisms 2Z-0, 2Z-7 lower the sensor unit 30 to a position where it is easy to inspect the workpiece W. At this time, the position of the head 3a in the direction along the Z-axis may also be the same as the position of the head 3a in the direction along the Z-axis during the execution of the preparatory operation.

[0150] As Figure 11 shown, during the execution of the preparatory operation, in the region on the workpiece W, the Z moving mechanisms 2Z-1 to 2Z-6 raise the head 3a to a position where it will not contact the workpiece W, and the Z moving mechanisms 2Z-0, 2Z-7 position the lower ends E2 of the light shielding plates 37-1, 37-2 on the path RU shown by the path information Da. Thereby, the path RU is inspected.

[0151] Here, the position where it will not contact the workpiece W means a position in the Z1 direction compared to the highest position in the direction along the Z-axis among the positions of the path RU shown by the path information Da, and preferably, the head 3a can be positioned in the most Z1-direction by the Z moving mechanism 2Z. In addition, during the execution of the preparatory operation, the positions of the plurality of heads 3a in the direction along the Z-axis may be the same as each other or different from each other.

[0152] During the execution of the preparatory operation, when the light shielding plate 37 contacts the workpiece W, the detection unit 31 detects the contact with the workpiece W. In this case, the control unit 50 determines that the path RU is inappropriate, and may stop the execution of the preparatory operation, end the process without performing the printing operation, or may stop the execution of the preparatory operation and notify the user. In addition, the control unit 50 may also transfer to step S3 after correcting the path shown by the path information Da. Here, as a case where the path shown by the path information Da is inappropriate, for example, a case where the error in the configuration or shape of the workpiece W is above a predetermined value, a case where there is a foreign object on the workpiece W, etc. can be cited.

[0153] As Figure 12 shown, at the end of the preparatory operation, all the heads 3a are located in a region deviated from the region on the workpiece W. At this time, the position of the head 3a in the direction along the Z-axis may be the same as the position of the head 3a in the direction along the Z-axis during the execution of the preparatory operation, or may be different.

[0154] As described above, before performing the printing operation of ejecting the ink from the head 3a, the control unit 50 performs a preparatory operation of moving the light-shielding plates 37-1 and 37-2 along the workpiece W in a state where the head 3a does not eject the ink. Thus, in the printing operation, by using the detection result of the first detection unit in the preparatory operation, the collision between the workpiece W and the head 3a can be more reliably suppressed. In addition, the contact detection with the workpiece W in the preparatory operation can be performed only by using the light-shielding plate 37-1, and the contact detection using the light-shielding plate 37-2 can be omitted.

[0155] Figure 13 FIG. for explaining the start of the printing operation. Figure 14 FIG. for explaining the execution of the printing operation. Figure 15 FIG. for explaining the end of the printing operation. In Figures 13 to 15 it, the way of moving the movable body 2d of the X moving mechanism 2X in the X2 direction in the printing operation of step S3 is illustrated.

[0156] As Figure 13 shown, at the start of the printing operation, in a region deviated from the region on the workpiece W, the Z moving mechanisms 2Z-1 to 2Z-6 position the head 3a at a position where it is easy to move along the path RU, and, similarly to the preparatory operation, the Z moving mechanisms 2Z-0 and 2Z-7 lower the sensor unit 30 to a position where it is easy to inspect the workpiece W.

[0157] As Figure 14 shown, during the execution of the printing operation, in the region on the workpiece W, the Z moving mechanisms 2Z-1 to 2Z-6 position the head 3a on the path RU shown by the path information Da, and while the Z moving mechanisms 2Z-0 and 2Z-7 position the lower ends E2 of the light-shielding plates 37-1 and 37-2 on the path RU shown by the path information Da, the head 3a ejects the ink. Thus, printing is performed on the workpiece W.

[0158] During the execution of the printing operation, when the light-shielding plate 37 contacts the workpiece W, the detection unit 31 detects that the workpiece W has been contacted. In this case, the control unit 50 can end the process, or can continue to execute step S3 after correcting the path shown by the path information Da.

[0159] In the present embodiment, during the execution of the printing operation, the pinning process of temporarily hardening the ink on the workpiece W is performed by the irradiation unit 32-2 located behind the head 3a in the moving direction among the irradiation units 32-1 and 32-2. In addition, this pinning process is performed as needed and can be omitted.

[0160] As Figure 15As shown, at the end of the printing operation, all the heads 3a are located in an area deviated from the area on the workpiece W. At this time, although the position of the head 3a in the direction along the Z-axis is not particularly limited, from the perspective of further improving safety, it is preferably the same as the position of the head 3a in the direction along the Z-axis during the execution of the preparatory operation.

[0161] Thus, when the light shielding plate 37 is scanned along the workpiece W during the execution of the printing operation, the control unit 50 preferably positions the lower end E2 of the light shielding plate 37 in the vertical direction at the same position as or below the lower end of the head 3a in the vertical direction. As a result, the light shielding plate 37 moves in a manner following the movement path of the head 3a, that is, the path RU. Therefore, the contact between the head 3a and the workpiece W can be appropriately detected by the detection unit 31-1. In addition, the light LL emitted from the irradiation unit 32 toward the head 3a can be appropriately shielded by the light shielding plate 37.

[0162] Figure 16 FIG. is for explaining the start of the hardening operation. Figure 17 FIG. is for explaining the execution of the hardening operation. Figure 18 FIG. is for explaining the end of the hardening operation. In Figures 16 to 18 it illustrates the manner in which the movable body 2d of the X moving mechanism 2X is moved in the X1 direction during the preparatory operation in step S4.

[0163] As Figure 16 shown, at the start of the hardening operation, similar to the start of the preparatory operation, in an area deviated from the area on the workpiece W, the Z moving mechanisms 2Z-0 to 2Z-7 operate.

[0164] As Figure 17 shown, during the execution of the hardening operation, in the area on the workpiece W, the Z moving mechanisms 2Z-1 to 2Z-6 raise the head 3a to a position where it does not contact the workpiece W, and the Z moving mechanisms 2Z-0, 2Z-7 position the lower ends E2 of the light shielding plates 37-1, 37-2 on the path RU shown in the path information Da. At this time, the irradiation unit 32 irradiates the light LL. As a result, the ink on the workpiece W is hardened by the light LL. In addition, during the execution of the hardening operation, the position of the light shielding plate 37 can be a position closer to the Z2 direction compared to the position during the execution of the preparatory operation or the printing operation.

[0165] As Figure 18 shown, at the end of the hardening operation, all the heads 3a are located in an area deviated from the area on the workpiece W. At this time, although the position of the head 3a in the direction along the Z-axis is not particularly limited, from the perspective of further improving safety, it is preferably the same as the position of the head 3a in the direction along the Z-axis during the execution of the preparatory operation.

[0166] As described above, when the control unit 50 irradiates the ink on the workpiece W with the light LL from the irradiation unit 32 during the printing operation and the hardening operation, the lower end of the light shielding plate 37 in the vertical direction is located at the same position as or below the lower end of the head 3a in the vertical direction.

[0167] In addition, when the control unit 50 performs the hardening operation, it is preferable that the lower end of the light shielding plate 37 in the vertical direction is located below the lower end of the head 3a in the vertical direction.

[0168] According to the above structure, the light LL from the irradiation unit 32 toward the head 3a can be appropriately shielded by the light shielding plate 37. In addition, the hardening operation is performed as needed and can also be omitted.

[0169] In the above three-dimensional object printing apparatus 1, by controlling the operation of the X moving mechanism 2X based on the detection result of the detection unit 31, the contact between the head 3a and the workpiece W can be suppressed. In addition, since the detection unit 31 detects the contact with the workpiece W based on the contact between the light shielding plate 37 and the workpiece W, the contact with the workpiece W can be detected with high accuracy compared to the method in which the detection unit 31 does not use the light shielding plate 37. Here, by using the light shielding plate 37 in the detection unit 31, the device structure can be simplified compared to the method of using another component to improve the detection accuracy of the detection unit 31. That is, by making the light shielding plate 37 not only have the light shielding function of shielding the light LL from the irradiation unit 32 toward the head 3a but also serve as a component for improving the detection accuracy of the detection unit 31, the device structure can be simplified.

[0170] 2. Second Embodiment

[0171] Hereinafter, a second embodiment of the present disclosure will be described. In the following exemplified embodiments, elements having the same functions and operations as those in the first embodiment are denoted by the same reference numerals used in the description of the first embodiment, and their detailed descriptions are appropriately omitted.

[0172] Figure 19 FIG. is a flowchart showing the operation of the three-dimensional object printing apparatus 1 according to the second embodiment. The operation of the three-dimensional object printing apparatus 1 of the present embodiment is the same as that of the three-dimensional object printing apparatus 1 of the first embodiment except for performing multi-pass printing. Specifically, the operation of the three-dimensional object printing apparatus 1 of the present embodiment is the same as that of the three-dimensional object printing apparatus 1 of the first embodiment except for adding steps S6 to S9 and step S40.

[0173] In the present embodiment, after step S4, a line change operation is performed in step S6. The line change operation changes the path to be scanned by the print head 3a.

[0174] After step S6, a preparatory operation is performed in step S7. The preparatory operation in step S7 may be the same as or different from the preparatory operation in step S2. However, the paths for the preparatory operations in step S7 and step S2 are different. In addition, from the perspective of promoting the hardening of the ink on the workpiece W, the preparatory operation in step S7 may also irradiate light LL from the irradiation unit 32 onto the workpiece W.

[0175] After step S7, a printing operation is performed in step S8. The printing operation in step S8 is the same as the printing operation in step S3 except for the scanning path of the print head 3a.

[0176] After step S8, in step S40, a hardening operation is performed in the same manner as in step S4. Each time, in step S9, it is determined whether there is a next pass. If there is a next pass (step S9: Yes), step S6 is executed. On the other hand, if there is no next pass (step S9: No), step S5 is executed. As described above, printing with different scanning paths of the print head 3a is performed for the desired number of passes.

[0177] Figure 20 FIG. is a diagram for explaining the line change operation. In Figure 20 it shows the paths RU-1 and RU-2 shown in the path information Da in the case where the number of passes is 2.

[0178] Path RU-1 is the path RU along which the print head 3a is to move in the printing operation in step S3. Path RU-2 is the path RU along which the print head 3a is to move in the printing operation in step S8, and is offset in a direction crossing the scanning direction with respect to path RU-2.

[0179] In the line change operation in step S6, by the operation of the support mechanism 4, the path RU along which the print head 3a is to move is changed from path RU-1 to path RU-2.

[0180] According to the above second embodiment, it is also possible to suppress the contact between the print head 3a and the workpiece W while simplifying the device structure.

[0181] 3. Third Embodiment

[0182] Hereinafter, a third embodiment of the present disclosure will be described. In the following exemplified embodiments, elements having the same functions and actions as those in the first embodiment are denoted by the same reference numerals used in the description of the first embodiment, and their detailed descriptions are appropriately omitted.

[0183] Figure 21

[0183] is a flowchart showing the operation of the three-dimensional object printing apparatus according to the third embodiment. The operation of the three-dimensional object printing apparatus 1 in this embodiment is the same as that of the three-dimensional object printing apparatus 1 in the first embodiment, except for performing thick-layer printing. Specifically, the operation of the three-dimensional object printing apparatus 1 in this embodiment is the same as that of the three-dimensional object printing apparatus 1 in the first embodiment, except that step S10 is added. In addition, thick-layer printing is a printing method in which printing is performed by laminating a plurality of printing layers so that the surface of the workpiece W becomes a raised state.

[0184] In this embodiment, after step S4, in step S10, it is determined whether the printing operation has reached a predetermined number of times. When the printing operation has not reached the predetermined number of times (step S10: No), step S3 is executed. On the other hand, when the printing operation has reached the predetermined number of times (step S10: Yes), step S5 is executed. As described above, the same printing of the scanning path of the head 3a is repeatedly performed a predetermined number of times.

[0185] In addition, since a plurality of printing layers are laminated in thick-layer printing, in the locking operation and the hardening operation during the printing operation, the hardening of the ink may sometimes be insufficient. In this case, the hardening operation may also be additionally performed when the printing operation has reached the predetermined number of times (step S10: Yes).

[0186] As described above, the three-dimensional object printing apparatus 1 further includes a control module 6 as an example of a "head control unit". The control module 6 controls the driving of the head 3a. As described above, the control module 6 performs thick-layer printing in which ink is ejected from the head 3a toward a position overlapping at least a part of the ink on the workpiece W. Thereby, thick-layer printing can be performed.

[0187] According to the above third embodiment, it is also possible to suppress the contact between the head 3a and the workpiece W while simplifying the device structure.

[0188] 4. Fourth Embodiment

[0189] Hereinafter, a fourth embodiment of the present disclosure will be described. In the following exemplified embodiments, elements having the same functions and operations as those in the first embodiment are denoted by the same reference numerals used in the description of the first embodiment, and their detailed descriptions are appropriately omitted.

[0190] Figure 22It is a right side view of the sensor unit 30A of the fourth embodiment. The sensor unit 30A is configured in the same manner as the sensor unit 30 of the first embodiment, except that it includes a light shielding plate 37A instead of the light shielding plate 37 of the first embodiment. The light shielding plate 37A is configured in the same manner as the light shielding plate 37 of the first embodiment, except that the shape in plan view is different.

[0191] The light shielding plate 37A is divided into a first light shielding portion 37b and a second light shielding portion 37c as regions that are different from each other in the direction along the Z axis. Thus, the light shielding plate 37A has the first light shielding portion 37b and the second light shielding portion 37c. The second light shielding portion 37c is provided below the first light shielding portion 37b in the vertical direction and includes the lower end E2 of the light shielding plate 37A in the vertical direction.

[0192] In the direction along the Y axis, the length Ws1 from one end to the other end of the first light shielding portion 37b is preferably equal to or greater than the length Wu from one end to the other end of the irradiation surface FL of the irradiation portion 32. Thus, the light shielding plate 37 can appropriately shield the light from the irradiation portion 32 toward the head 3a.

[0193] In addition, in the direction along the Y axis, the length Ws2 from one end to the other end of the second light shielding portion 37c is shorter than the length Ws1 from one end to the other end of the first light shielding portion 37b and is equal to or greater than the length Wn from one end to the other end of the head 3a. When the printing surface of the workpiece W is curved when observed in the direction along the X axis, if the width of the lower end E2 of the light shielding plate 37A is greater than the width of the head 3a, since the light shielding plate 37 moves following the path RU which is the movement path of the head 3a, in order to avoid the collision between the light shielding plate 37A and the workpiece W, it is necessary to increase the distance PG between the head 3a and the workpiece W. As a result, the printing quality will deteriorate. In contrast, if the width, i.e., the length Ws2, of the second light shielding portion 37c is shorter than the width, i.e., the length Ws1, of the first light shielding portion 37b and is equal to or greater than the width, i.e., the length Wn, of the head 3a, it is possible to reduce the distance PG between the head 3a and the workpiece W while ensuring the required light shielding property of the light shielding plate 37A. As a result, the printing quality can be improved.

[0194] According to the above fourth embodiment, it is also possible to suppress the contact between the head 3a and the workpiece W while simplifying the device structure. In addition, although an example in which the width of the second light shielding portion 37c is substantially fixed is shown, it is not limited to this mode. For example, it may be set such that the width of the second light shielding portion 37c continuously or stepwise decreases as it approaches the lower end E2.

[0195] 5. Modification

[0196] Each of the above examples can be modified in various ways. Hereinafter, specific modification methods applicable to each of the above methods will be exemplified. In addition, two or more methods arbitrarily selected from the following examples can be appropriately combined within a non - conflicting range.

[0197] 5 - 1. Modification Example 1

[0198] Although in the foregoing embodiment, a method in which the light - shielding plate 37 is supported by a Z - moving mechanism 2Z different from the head 3a is exemplified, it is not limited to this method. It can also be set such that the Z - moving mechanism 2Z that supports the head 3a supports the light - shielding plate 37.

[0199] In addition, although a method in which the sensor unit 30 having the irradiation unit 32 and the light - shielding plate 37 is supported by one Z - moving mechanism 2Z is exemplified, Z - moving mechanisms 2Z that respectively support the irradiation unit 32 and the light - shielding plate 37 can also be provided.

[0200] 5 - 2. Modification Example 2

[0201] Although in the foregoing method, a method in which the number of Z - moving mechanisms 2Z that move the head 3a along the Z - axis is 6 is exemplified, it is not limited to this method. The number or the number of heads 3a can also be 5 or less or 7 or more.

[0202] 5 - 3. Modification Example 3

[0203] Although in the foregoing method, a method in which the robotic arm 4W is a six - axis articulated robotic arm is exemplified, the number of joints of the robotic arm 4W is not limited to 6. It can be 2 or more and 5 or less, or 7 or more. In addition, the robotic arm 4W is provided as needed and can also be omitted.

[0204] 5 - 4. Modification Example 4

[0205] Although in the foregoing method, a method in which the detection unit 31 is a contact - type sensor is exemplified, depending on the type of liquid ejected from the head 3a, it can also be an optical sensor. In addition, even when a photo - curable ink is used, as long as it is an optical sensor composed of an LED that irradiates light without ultraviolet rays, the photo - curable ink will not be cured, so it can also be used.

[0206] 5 - 5. Modification Example 5

[0207] Although in the foregoing fourth embodiment, a method in which the light - shielding plate 37A has the first light - shielding portion 37b and the second light - shielding portion 37c is exemplified, the following method can also be adopted, that is, the width of the light - shielding plate 37A in the direction along the Y - axis gradually or curvilinearly decreases as it tends to the Z2 direction.

[0208] 6. Supplementary Notes

[0209] The following are supplementary notes on the summary of the present disclosure.

[0210] Supplementary Note 1

[0211] The first mode, which is a preferred example of the three-dimensional object printing apparatus of the present disclosure, includes: a moving mechanism having a carriage that moves along a first axis; a head that ejects a liquid toward a workpiece; a first lifting mechanism that is supported by the carriage and raises and lowers the head along a second axis intersecting the first axis; a first irradiation unit that is supported by the carriage and irradiates the workpiece with light that hardens the liquid ejected from the head; a first light shielding plate that is supported by the carriage and is disposed at a position between the head and the first irradiation unit in the direction along the first axis and shields the light from the first irradiation unit toward the head; and a first detection unit that detects contact with the workpiece based on contact between the first light shielding plate and the workpiece.

[0212] In the above mode, by controlling the operation of the moving mechanism based on the detection result of the first detection unit, it is possible to suppress contact between the head and the workpiece. In addition, since the first detection unit detects contact with the workpiece based on contact between the first light shielding plate and the workpiece, it is possible to detect contact with the workpiece with high precision compared to a mode in which the first detection unit does not use the first light shielding plate. Here, by using the first light shielding plate in the first detection unit, the device structure can be simplified compared to a mode in which additional components are used to improve the detection accuracy of the first detection unit. That is, by making the first light shielding plate not only have a light shielding function of shielding the light from the first irradiation unit toward the head but also serve as a component for improving the detection accuracy of the first detection unit, the device structure can be simplified.

[0213] Supplementary Note 2

[0214] In the second mode, which is a preferred example of the first mode, a second detection unit is further provided. The second detection unit is supported by the carriage and is disposed at a position opposite to the position where the first light shielding plate is disposed with respect to the head in the direction along the first axis and detects contact with the workpiece. In the above mode, even when printing the workpiece by reciprocating scanning of the head, it is possible to suppress contact between the head and the workpiece.

[0215] Supplementary Note 3

[0216] In a third mode which is a preferred example of the second mode, there is further provided: a second irradiation unit which is disposed at a position opposite to the position where the first light shielding plate is disposed with respect to the head in a direction along the first axis, and irradiates light for hardening the liquid ejected from the head toward the workpiece; a second light shielding plate which is disposed at a position between the head and the second irradiation unit in a direction along the first axis, and shields the light from the second irradiation unit toward the head, and the second detection unit detects the contact with the workpiece based on the contact between the second light shielding plate and the workpiece. In the above mode, in the case of performing printing on the workpiece by the reciprocating scan of the head, necessary light shielding for the head can be achieved, and the productivity can be improved by hardening the liquid on the workpiece in the forward path and the return path, respectively. In addition, by using the second light shielding plate for the second detection unit, the device structure can be simplified compared with a mode in which another component is used to improve the detection accuracy of the second detection unit.

[0217] Supplementary Note 4

[0218] In a fourth mode which is a preferred example of any one of the first mode to the third mode, there is further provided: a second lifting mechanism which is supported by the carriage and raises and lowers the first light shielding plate along the second axis; a control unit which controls the operations of the first lifting mechanism and the second lifting mechanism, the second axis being an axis along the vertical direction, and the control unit, when irradiating light from the first irradiation unit toward the liquid on the workpiece, makes the lower end of the first light shielding plate in the vertical direction be at the same position as or below the lower end of the head in the vertical direction. In the above mode, the light from the first irradiation unit toward the head can be appropriately shielded by the first light shielding plate.

[0219] Supplementary Note 5

[0220] In a fifth mode which is a preferred example of the fourth mode, in a direction along a third axis intersecting the first axis and the second axis, the length of the irradiation surface of the first irradiation unit from one end to the other end is equal to or greater than the length of the head from one end to the other end, and the length of the first light shielding plate from one end to the other end is equal to or greater than the length of the head from one end to the other end. In the above mode, when performing printing on a three-dimensional printing surface of a workpiece, depending on the shape of the printing surface, the liquid sprayed onto the printing surface may sometimes easily shift or spread. Therefore, by setting the width of the irradiation surface to be equal to or greater than the width of the head, the liquid sprayed onto the printing surface can be quickly hardened, and as a result, the shift or spread of the liquid sprayed onto the printing surface can be suppressed. In addition, by setting the width of the first light shielding plate to be equal to or greater than the width of the head, the light from the first irradiation unit toward the head can be appropriately shielded by the first light shielding plate.

[0221] Supplementary Note 6

[0222] In a sixth mode which is a preferred example of the fifth mode, the first light shielding plate has: a first light shielding portion; a second light shielding portion provided below the first light shielding portion in the vertical direction and including the lower end of the first light shielding plate in the vertical direction. In the direction along the third axis, the length of the first light shielding portion from one end to the other end is equal to or greater than the length of the irradiation surface of the first irradiation unit from one end to the other end, the length of the second light shielding portion from one end to the other end is shorter than the length of the first light shielding portion from one end to the other end, and is equal to or greater than the length of the head from one end to the other end. In the above mode, when the printing surface of the workpiece is bent when observed in the direction along the first axis, if the width of the lower end of the first light shielding plate is greater than the width of the head, the greater the width of the lower end of the first light shielding plate, the greater the distance between the head and the workpiece needs to be increased to avoid collision between the first light shielding plate and the workpiece. As a result, the printing quality will deteriorate. In contrast, if the width of the second light shielding portion is shorter than the width of the first light shielding portion and is equal to or greater than the width of the head, the distance between the head and the workpiece W can be reduced while ensuring the required light shielding property of the first light shielding plate. As a result, the printing quality can be improved.

[0223] Supplementary Note 7

[0224] In a seventh mode which is a preferred example of any one of the fourth mode to the sixth mode, in the direction along the first axis, the length between the head and the first light shielding plate is equal to or greater than the length between the first irradiation unit and the first light shielding plate. In the above mode, compared with the mode where the length between the head and the first light shielding plate is shorter than the length between the first irradiation unit and the first light shielding plate, the required light shielding effect of the first light shielding plate can be improved.

[0225] Supplementary Note 8

[0226] In an eighth mode which is a preferred example of any one of the first mode to the seventh mode, it further includes: a second lifting mechanism which is supported by the carriage and lifts the first light-shielding plate along the second axis; a control unit which controls the operations of the first lifting mechanism and the second lifting mechanism, the second axis being an axis along the vertical direction, and when the control unit scans the first light-shielding plate along the workpiece, the lower end of the first light-shielding plate in the vertical direction is located at the same position as the lower end of the head in the vertical direction or at a position below the lower end of the head in the vertical direction. In the above mode, since the first light-shielding plate moves following the movement path of the head, the contact between the head and the workpiece can be appropriately detected by the first detection unit.

[0227] Supplementary Note 9

[0228] In a ninth mode which is a preferred example of the eighth mode, the first light-shielding plate is fixed to the second lifting mechanism via an elastic member having elasticity, and the lower end of the first light-shielding plate in the vertical direction is a free end. In the above mode, damage to the workpiece caused by contact with the first light-shielding plate can be suppressed.

[0229] Supplementary Note 10

[0230] In a tenth mode which is a preferred example of the eighth mode or the ninth mode, in the direction along the first axis, the length between the head and the first light-shielding plate is longer than the moving distance required from the detection of the contact between the workpiece and the first light-shielding plate based on the detection result of the first detection unit until the carriage stops. In the above mode, the contact between the head and the workpiece can be more reliably suppressed.

[0231] Supplementary Note 11

[0232] In an eleventh mode which is a preferred example of any one of the eighth mode to the tenth mode, the first detection unit includes: a needle-like body having a tip that contacts the first light-shielding plate; a sensor that detects the displacement of the tip. In the above mode, the contact with the workpiece can be detected by the first detection unit under the condition that problems such as the hardening of the liquid of the head by light do not occur in an optical sensor.

[0233] Supplementary Note 12

[0234] In a twelfth mode which is a preferred example of the eleventh mode, the first detection unit is configured to detect, using the sensor, whether the displacement of the tip from the natural state is equal to or greater than a predetermined distance, and the needle-like body contacts the first light-shielding plate in a state where the tip has an initial displacement in a manner of reducing the predetermined distance. In the above mode, it is possible to quickly detect the situation where the first light-shielding plate contacts the workpiece by the first detection unit. Therefore, even if the length between the head and the first light-shielding plate is shortened, it is possible to appropriately suppress the collision between the workpiece and the head.

[0235] Supplementary Note 13

[0236] In a thirteenth mode which is a preferred example of any one of the first mode to the twelfth mode, a control unit is further provided, and the control unit controls the operation of the moving mechanism. Before performing a printing operation in which the liquid is ejected from the head, the control unit performs a preparatory operation of moving the first light-shielding plate along the workpiece in a state where the head does not eject the liquid. In the above mode, by using the detection result of the first detection unit in the preparatory operation during the printing operation, it is possible to more reliably suppress the collision between the workpiece and the head.

[0237] Supplementary Note 14

[0238] In a fourteenth mode which is a preferred example of any one of the first mode to the thirteenth mode, a head control unit is further provided, and the head control unit controls the driving of the head. The head control unit performs thick-layer printing in which the liquid is ejected from the head toward a position overlapping at least a part of the liquid on the workpiece. In the above mode, thick-layer printing can be performed.

[0239] Symbol Explanation

[0240] 1…Three-dimensional object printing device; 2…Moving mechanism; 2X…X moving mechanism; 2Z…Z moving mechanism; 2Z-0 to 2Z-7…Z moving mechanisms; 2a…Column; 2b…Beam; 2c…Track; 2d…Movable body; 2e…Support body; 3…Head unit; 3-1…Head unit; 3-2…Head unit; 3a…Head; 3b…Flow channel structure; 3e…Switching circuit; 3f…Protective component; 3f1…Opening; 3g…Support body; 3h…Cover; 3i1…Supply pipe; 3i2…Discharge pipe; 4…Support mechanism; 4W…Robot arm; 4Y…Y moving mechanism; 4a…Support body; 4b…Track; 4c…Movable body; 4d…Carriage; 5…Controller; 5a…Storage circuit; 5b…Processing circuit; 6…Control module (head control unit); 6a…Timing signal generation circuit; 6b…Power supply circuit; 6c…Control circuit; 6d…Drive signal generation circuit; 7…Computer; 7a…Storage circuit; 7b…Processing circuit; 8…Maintenance mechanism; 8C…Cleaning device; 8F…Cover mechanism; 8M…Cleaning device moving mechanism; 8P…Cover; 10…Base; 10a…Surface; 10b…Opening; 10c…Placement part; 11…Housing; 11a…Visual confirmation part; 26…Component; 30…Sensor unit; 30-1…Sensor unit; 30-2…Sensor unit; 30A…Sensor unit; 31…Detection part; 31-1…Detection part (first detection part); 31-2…Detection part (second detection part); 31a…Needle-like body; 31b…Sensor; 32…Irradiation part; 32-1…Irradiation part (first irradiation part); 32-2…Irradiation part (second irradiation part); 32a…Needle-like body; 33…Detection part; 34…Support body; 35…Mounting component; 35a…Long hole; 36…Buffer body; 36a…Component; 36a1…Component; 36a2…Component; 36b…Component; 36b1…Component; 36b2…Component; 36b3…Component; 36c…Elastic component; 36d…Leaf spring; 36d1…Long hole; 37…Light shield; 37-1…Light shield (first light shield); 37-2…Light shield (second light shield); 37A…Light shield; 37a…Groove; 37b…First light shielding part; 37c…Second light shielding part; 50…Control unit; AR…Arm; CLK…Clock signal; CNG…Exchange signal; Com…Drive signal; D1…Output signal; D3…Signal; DN…Nozzle row direction; Da…Path information; Db…Path information; Dw…Output; Dx…Output signal; Dz-0 to Dz-7…Output signals; E1…Tip; E2…Lower end; FC…Surface; FL…Irradiation surface; FN…Nozzle surface; FT…Spraying surface; LAT…Latch signal; LL…Light; N…Nozzle; NL…Nozzle row; NLa…Nozzle row; NLb…Nozzle row; PD…Drive pulse; PG…Distance; PTS…Timing signal; RU…Path; RU-1…Path; RU-2…Path; S1…Step; S2…Step; S3…Step; S4…Step; S5…Step;S6… step; S7… step; S8… step; S9… step; S10… step; SI… control signal; SI-1… control signal; Sw… control signal; Sx… control signal; Sz-0 to Sz-7… control signals; VBS… bias potential; VHV… power supply potential; W… workpiece; WF… surface; dCom… waveform specifying signal;

Claims

1. A three-dimensional object printing device, characterized in that: have: A moving mechanism having a carriage that moves along a first axis; a head that sprays liquid toward the workpiece; a first lifting mechanism supported by the carriage and configured to lift and lower the head along a second axis intersecting the first axis; a first irradiation unit supported by the carriage and irradiating light toward the workpiece to harden the liquid ejected from the head; a first light shielding plate supported by the carriage and disposed between the head and the first irradiation unit in a direction along the first axis, and shielding light from the first irradiation unit toward the head; The first detection unit detects contact with the workpiece based on contact between the first light shielding plate and the workpiece.

2. The three-dimensional object printing device according to claim 1, characterized in that: A second detection unit is further provided, the second detection unit being supported by the carriage and arranged at a position opposite to a position where the first light shielding plate is arranged with respect to the head in a direction along the first axis, and detecting contact with the workpiece.

3. The three-dimensional object printing device according to claim 2, characterized in that: Also available: a second irradiation unit disposed at a position opposite to the position where the first light shielding plate is disposed relative to the head in the direction along the first axis and irradiating light toward the workpiece to cure the liquid ejected from the head; a second light shielding plate disposed between the head and the second irradiation unit in the direction along the first axis and shielding light from the second irradiation unit toward the head, The second detection unit detects contact with the workpiece based on contact between the second light shielding plate and the workpiece.

4. The three-dimensional object printing device according to claim 1, wherein: Also available: a second lifting mechanism, which is supported by the slide and causes the first light shielding plate to be lifted and lowered along the second axis; a control unit for controlling the actions of the first lifting mechanism and the second lifting mechanism, The second axis is an axis along the vertical direction, When the control unit irradiates light from the first irradiation unit toward the liquid on the workpiece, the control unit positions the lower end of the first light shielding plate at the same position as or below the lower end of the head in the vertical direction.

5. The three-dimensional object printing device according to claim 4, characterized in that: In a direction along a third axis intersecting the first axis and the second axis, The length of the irradiation surface of the first irradiation section from one end to the other end is greater than the length of the head from one end to the other end. The length of the first light shielding plate from one end to the other end is greater than or equal to the length of the head from one end to the other end.

6. The three-dimensional object printing device according to claim 5, characterized in that: The first shading plate has: a first light shielding portion; a second light shielding portion, which is disposed below the first light shielding portion in the vertical direction and includes a lower end of the first light shielding plate in the vertical direction, In the direction along the third axis, The length of the first light shielding portion from one end to the other end is greater than the length of the irradiation surface of the first irradiation portion from one end to the other end. The length of the second light shielding portion from one end to the other end is shorter than the length of the first light shielding portion from one end to the other end and is equal to or longer than the length of the head from one end to the other end.

7. The three-dimensional object printing device according to claim 4, characterized in that: In the direction along the first axis, the length between the head and the first light shielding plate is greater than or equal to the length between the first irradiation unit and the first light shielding plate.

8. The three-dimensional object printing device according to claim 1, wherein: Also available: a second lifting mechanism, which is supported by the slide and causes the first light shielding plate to be lifted and lowered along the second axis; a control unit for controlling the actions of the first lifting mechanism and the second lifting mechanism, The second axis is an axis along the vertical direction, When the control unit causes the first light shielding plate to scan along the workpiece, the control unit positions a lower end of the first light shielding plate at the same position as or below a lower end of the head in the vertical direction.

9. The three-dimensional object printing device according to claim 8, characterized in that: The first shading plate is fixed to the second lifting mechanism via an elastic member having elasticity. The lower end of the first light shielding plate in the vertical direction is a free end.

10. The three-dimensional object printing device according to claim 8, wherein: In the direction along the first axis, The length between the head and the first light shielding plate is longer than a moving distance required from when contact between the workpiece and the first light shielding plate is detected based on a detection result of the first detection unit to when the carriage stops.

11. The three-dimensional object printing device according to claim 8, characterized in that: The first detection unit has: a needle-shaped body having a tip in contact with the first light shielding plate; A sensor detects the displacement of the tip.

12. The three-dimensional object printing device according to claim 11, wherein: The first detection unit is configured to detect, using the sensor, whether the displacement of the tip from the natural state is greater than a predetermined distance. The needle-shaped body contacts the first light shielding plate in a state where the tip is initially displaced so as to reduce the predetermined distance.

13. The three-dimensional object printing device according to any one of claims 1 to 12, characterized in that: The device further comprises a control unit for controlling the movement of the moving mechanism. The control unit performs a preparatory operation of moving the first light shielding plate along the workpiece in a state where the head does not discharge liquid, before performing a printing operation of discharging liquid from the head.

14. The three-dimensional object printing device according to any one of claims 1 to 12, characterized in that: A head control unit is further provided, the head control unit controls the driving of the head, The head control unit performs thick layer printing in which the liquid is ejected from the head toward a position overlapping with at least a portion of the liquid on the workpiece.

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